National Library of Energy BETA

Sample records for noise suppression systems

  1. Noise suppressing capillary separation system

    DOE Patents [OSTI]

    Yeung, Edward S. (Ames, IA); Xue, Yongjun (Norwich, NY)

    1996-07-30

    A noise-suppressing capillary separation system for detecting the real-time presence or concentration of an analyte in a sample is provided. The system contains a capillary separation means through which the analyte is moved, a coherent light source that generates a beam which is split into a reference beam and a sample beam that irradiate the capillary, and a detector for detecting the reference beam and the sample beam light that transmits through the capillary. The laser beam is of a wavelength effective to be absorbed by a chromophore in the capillary. The system includes a noise suppressing system to improve performance and accuracy without signal averaging or multiple scans.

  2. Noise suppressing capillary separation system

    DOE Patents [OSTI]

    Yeung, E.S.; Xue, Y.

    1996-07-30

    A noise-suppressing capillary separation system for detecting the real-time presence or concentration of an analyte in a sample is provided. The system contains a capillary separation means through which the analyte is moved, a coherent light source that generates a beam which is split into a reference beam and a sample beam that irradiate the capillary, and a detector for detecting the reference beam and the sample beam light that transmits through the capillary. The laser beam is of a wavelength effective to be absorbed by a chromophore in the capillary. The system includes a noise suppressing system to improve performance and accuracy without signal averaging or multiple scans. 13 figs.

  3. SURVEY OF NOISE SUPPRESSION SYSTEMS FOR ENGINE GENERATOR SETS...

    Office of Scientific and Technical Information (OSTI)

    POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS; ENGINES; NOISE POLLUTION ABATEMENT; POLLUTION CONTROL EQUIPMENT; ELECTRIC GENERATORS No abstract prepared....

  4. Noise Suppression and Spectral Decomposition for State-Dependent Noise

    E-Print Network [OSTI]

    Arnold, Elizabeth A.

    Noise Suppression and Spectral Decomposition for State-Dependent Noise in the Presence been shown that the observed noise amplitude of an intrinsically noisy system may be reduced by causing noise reduction in terms of the low-frequency end of the spectrum as well as the integrated spectrum

  5. A Model of the Lateral Geniculate Complex of the Turtle Visual System: Noise Suppression and Target Motion Detection

    E-Print Network [OSTI]

    Ghosh, Bijoy K.

    A Model of the Lateral Geniculate Complex of the Turtle Visual System: Noise Suppression and Target-Cybernetics and Intelligent Systems (CBCIS) at Texas Tech University, served as my thesis advisor and com- mittee chair of this work - showing an unwavering dedication to the topic of modeling vision neural systems. As a long

  6. Subspace modelling for structured noise suppression

    E-Print Network [OSTI]

    Zhiqiang Xu; Laura Rebollo-Neira; A. Plastino

    2009-08-07

    The problem of structured noise suppression is addressed by i)modelling the subspaces hosting the components of the signal conveying the information and ii)applying a non-extensive nonlinear technique for effecting the right separation. Although the approach is applicable to all situations satisfying the hypothesis of the proposed framework, this work is motivated by a particular scenario, namely, the cancellation of low frequency noise in broadband seismic signals.

  7. SU-E-J-243: Possibility of Exposure Dose Reduction of Cone-Beam Computed Tomography in An Image Guided Patient Positioning System by Using Various Noise Suppression Filters

    SciTech Connect (OSTI)

    Kamezawa, H; Arimura, H; Ohki, M; Shirieda, K; Kameda, N

    2014-06-01

    Purpose: To investigate the possibility of exposure dose reduction of the cone-beam computed tomography (CBCT) in an image guided patient positioning system by using 6 noise suppression filters. Methods: First, a reference dose (RD) and low-dose (LD)-CBCT (X-ray volume imaging system, Elekta Co.) images were acquired with a reference dose of 86.2 mGy (weighted CT dose index: CTDIw) and various low doses of 1.4 to 43.1 mGy, respectively. Second, an automated rigid registration for three axes was performed for estimating setup errors between a planning CT image and the LD-CBCT images, which were processed by 6 noise suppression filters, i.e., averaging filter (AF), median filter (MF), Gaussian filter (GF), bilateral filter (BF), edge preserving smoothing filter (EPF) and adaptive partial median filter (AMF). Third, residual errors representing the patient positioning accuracy were calculated as an Euclidean distance between the setup error vectors estimated using the LD-CBCT image and RD-CBCT image. Finally, the relationships between the residual error and CTDIw were obtained for 6 noise suppression filters, and then the CTDIw for LD-CBCT images processed by the noise suppression filters were measured at the same residual error, which was obtained with the RD-CBCT. This approach was applied to an anthropomorphic pelvic phantom and two cancer patients. Results: For the phantom, the exposure dose could be reduced from 61% (GF) to 78% (AMF) by applying the noise suppression filters to the CBCT images. The exposure dose in a prostate cancer case could be reduced from 8% (AF) to 61% (AMF), and the exposure dose in a lung cancer case could be reduced from 9% (AF) to 37% (AMF). Conclusion: Using noise suppression filters, particularly an adaptive partial median filter, could be feasible to decrease the additional exposure dose to patients in image guided patient positioning systems.

  8. ADAPTIVE SUPPRESSION OF CCD SIGNAL-DEPENDENT NOISE IN LIGHT SPACE Hilda Faraji and James MacLean

    E-Print Network [OSTI]

    MacLean, W. James

    ADAPTIVE SUPPRESSION OF CCD SIGNAL-DEPENDENT NOISE IN LIGHT SPACE Hilda Faraji and James Mac on the estimated noise model in light space. Our adaptive system demonstrates efficient noise removal per- formance IN LIGHT SPACE We use adaptive filters to learn the local signal and noise characteristics so

  9. Explosion suppression system

    DOE Patents [OSTI]

    Sapko, Michael J. (Finleyville, PA); Cortese, Robert A. (Pittsburgh, PA)

    1992-01-01

    An explosion suppression system and triggering apparatus therefor are provided for quenching gas and dust explosions. An electrically actuated suppression mechanism which dispenses an extinguishing agent into the path ahead of the propagating flame is actuated by a triggering device which is light powered. This triggering device is located upstream of the propagating flame and converts light from the flame to an electrical actuation signal. A pressure arming device electrically connects the triggering device to the suppression device only when the explosion is sensed by a further characteristic thereof beside the flame such as the pioneer pressure wave. The light powered triggering device includes a solar panel which is disposed in the path of the explosion and oriented between horizontally downward and vertical. Testing mechanisms are also preferably provided to test the operation of the solar panel and detonator as well as the pressure arming mechanism.

  10. Pressure suppression containment system

    DOE Patents [OSTI]

    Gluntz, Douglas M. (San Jose, CA); Townsend, Harold E. (San Jose, CA)

    1994-03-15

    A pressure suppression containment system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The wetwell pool includes a plenum for receiving the non-condensable gas carried with steam from the drywell following a loss-of coolant-accident (LOCA). The wetwell plenum is vented to a plenum above the GDCS pool following the LOCA for suppressing pressure rise within the containment vessel. A method of operation includes channeling steam released into the drywell following the LOCA into the wetwell pool for cooling along with the non-condensable gas carried therewith. The GDCS pool is then drained by gravity, and the wetwell plenum is vented into the GDCS plenum for channeling the non-condensable gas thereto.

  11. Pressure suppression containment system

    DOE Patents [OSTI]

    Gluntz, D.M.; Townsend, H.E.

    1994-03-15

    A pressure suppression containment system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The wetwell pool includes a plenum for receiving the non-condensable gas carried with steam from the drywell following a loss-of-coolant-accident (LOCA). The wetwell plenum is vented to a plenum above the GDCS pool following the LOCA for suppressing pressure rise within the containment vessel. A method of operation includes channeling steam released into the drywell following the LOCA into the wetwell pool for cooling along with the non-condensable gas carried therewith. The GDCS pool is then drained by gravity, and the wetwell plenum is vented into the GDCS plenum for channeling the non-condensable gas thereto. 6 figures.

  12. Short wavelength limits of current shot noise suppression

    SciTech Connect (OSTI)

    Nause, Ariel; Dyunin, Egor; Gover, Avraham

    2014-08-15

    Shot noise in electron beam was assumed to be one of the features beyond control of accelerator physics. Current results attained in experiments at Accelerator Test Facility in Brookhaven and Linac Coherent Light Source in Stanford suggest that the control of the shot noise in electron beam (and therefore of spontaneous radiation and Self Amplified Spontaneous Emission of Free Electron Lasers) is feasible at least in the visible range of the spectrum. Here, we present a general linear formulation for collective micro-dynamics of e-beam noise and its control. Specifically, we compare two schemes for current noise suppression: a quarter plasma wavelength drift section and a combined drift/dispersive (transverse magnetic field) section. We examine and compare their limits of applicability at short wavelengths via considerations of electron phase-spread and the related Landau damping effect.

  13. Pressure suppression system

    DOE Patents [OSTI]

    Gluntz, D.M.

    1994-10-04

    A pressure suppression system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and an enclosed gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The GDCS pool includes a plenum for receiving through an inlet the non-condensable gas carried with steam from the drywell following a loss-of-coolant accident (LOCA). A condenser is disposed in the GDCS plenum for condensing the steam channeled therein and to trap the non-condensable gas therein. A method of operation includes draining the GDCS pool following the LOCA and channeling steam released into the drywell following the LOCA into the GDCS plenum for cooling along with the non-condensable gas carried therewith for trapping the gas therein. 3 figs.

  14. Pressure suppression system

    DOE Patents [OSTI]

    Gluntz, Douglas M. (San Jose, CA)

    1994-01-01

    A pressure suppression system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and an enclosed gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel. The GDCS pool includes a plenum for receiving through an inlet the non-condensable gas carried with steam from the drywell following a loss-of-coolant accident (LOCA). A condenser is disposed in the GDCS plenum for condensing the steam channeled therein and to trap the non-condensable gas therein. A method of operation includes draining the GDCS pool following the LOCA and channeling steam released into the drywell following the LOCA into the GDCS plenum for cooling along with the non-condensable gas carried therewith for trapping the gas therein.

  15. Quadrature mixture LO suppression via DSW DAC noise dither

    DOE Patents [OSTI]

    Dubbert, Dale F. (Cedar Crest, NM); Dudley, Peter A. (Albuquerque, NM)

    2007-08-21

    A Quadrature Error Corrected Digital Waveform Synthesizer (QECDWS) employs frequency dependent phase error corrections to, in effect, pre-distort the phase characteristic of the chirp to compensate for the frequency dependent phase nonlinearity of the RF and microwave subsystem. In addition, the QECDWS can employ frequency dependent correction vectors to the quadrature amplitude and phase of the synthesized output. The quadrature corrections cancel the radars' quadrature upconverter (mixer) errors to null the unwanted spectral image. A result is the direct generation of an RF waveform, which has a theoretical chirp bandwidth equal to the QECDWS clock frequency (1 to 1.2 GHz) with the high Spurious Free Dynamic Range (SFDR) necessary for high dynamic range radar systems such as SAR. To correct for the problematic upconverter local oscillator (LO) leakage, precision DC offsets can be applied over the chirped pulse using a pseudo-random noise dither. The present dither technique can effectively produce a quadrature DC bias which has the precision required to adequately suppress the LO leakage. A calibration technique can be employed to calculate both the quadrature correction vectors and the LO-nulling DC offsets using the radar built-in test capability.

  16. Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump

    E-Print Network [OSTI]

    Noise suppression and enhanced focusability in plasma Raman amplifier with multi-frequency pump A that backscatter of the desired seed pulse proceeds, the usual methods of noise suppression do not apply. In ideally uniform plasmas, the Raman instability of the plasma noise and precursor amplification

  17. Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image

    E-Print Network [OSTI]

    Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image of Mathematics, National Taiwan University, Taipei, Taiwan, 4 Elekta Oy, Helsinki, Finland Abstract Ultra-low. (2013) Suppressing Multi-Channel Ultra-Low-Field MRI Measurement Noise Using Data Consistency and Image

  18. LOW DISTORTION ACOUSTIC NOISE SUPPRESSION USING A PERCEPTUAL MODEL FOR SPEECH SIGNALS

    E-Print Network [OSTI]

    Kabal, Peter

    LOW DISTORTION ACOUSTIC NOISE SUPPRESSION USING A PERCEPTUAL MODEL FOR SPEECH SIGNALS Joachim, such as musical noise, and distortion of the speech signal. By employing an auditory model, psychoacoustic effects. By using techniques from audio enhancement and a sophisticated perceptual model, a large degree of noise

  19. Suppressing coherent noise in radar applications with long dwell times

    E-Print Network [OSTI]

    Allen, Christopher Thomas; Mozaffar, S. N.; Akins, T. L.

    2005-07-01

    digitally in the transmit waveform and removed digitally following digitization in the receiver. Experimental demonstration of this concept resulted in an additional noise floor reduction of 15 to 20 dB (compared to the conventional coherent averaging alone...

  20. Noise suppression of a differential detector under high-levels of illumination in terahertz electro-optic

    E-Print Network [OSTI]

    Noise suppression of a differential detector under high-levels of illumination in terahertz electro that these distortions significantly reduce the ability of the detector to suppress laser amplitude noise. 1 #12. Based on our measurements, we provide experimenters with recommendations to improve the amplitude noise

  1. Observation of Shot Noise Suppression at Optical Wavelengths in a Relativistic Electron Beam

    SciTech Connect (OSTI)

    Ratner, Daniel; Stupakov, Gennady; /SLAC

    2012-06-19

    Control of collective properties of relativistic particles is increasingly important in modern accelerators. In particular, shot noise affects accelerator performance by driving instabilities or by competing with coherent processes. We present experimental observations of shot noise suppression in a relativistic beam at the Linac Coherent Light Source. By adjusting the dispersive strength of a chicane, we observe a decrease in the optical transition radiation emitted from a downstream foil. We show agreement between the experimental results, theoretical models, and 3D particle simulations.

  2. Feedback suppression of rotating external kink instabilities in the presence of noise

    E-Print Network [OSTI]

    Mauel, Michael E.

    =vA/a, but a conducting wall at the plasma boundary can interact with the mode. The resulting plasma-wall mode is termed experimental demonstration of active feedback suppression of rotating external kink modes near the ideal wall limit in a tokamak using Kalman filtering to discriminate the n=1 kink mode from background noise

  3. Optimal noise suppression in Fresnel incoherent correlation holography (FINCH) configured for

    E-Print Network [OSTI]

    Rosen, Joseph

    Optimal noise suppression in Fresnel incoherent correlation holography (FINCH) configured 131543); published 14 October 2010 An optimal setup in the sense of imaging resolution for the Fresnel of America OCIS codes: 090.1995, 030.6140, 110.4280. 1. Introduction Fresnel incoherent correlation

  4. Noise suppression in reconstruction of low-Z target megavoltage cone-beam CT images

    SciTech Connect (OSTI)

    Wang Jing; Robar, James; Guan Huaiqun

    2012-08-15

    Purpose: To improve the image contrast-to-noise (CNR) ratio for low-Z target megavoltage cone-beam CT (MV CBCT) using a statistical projection noise suppression algorithm based on the penalized weighted least-squares (PWLS) criterion. Methods: Projection images of a contrast phantom, a CatPhan{sup Registered-Sign} 600 phantom and a head phantom were acquired by a Varian 2100EX LINAC with a low-Z (Al) target and low energy x-ray beam (2.5 MeV) at a low-dose level and at a high-dose level. The projections were then processed by minimizing the PWLS objective function. The weighted least square (WLS) term models the noise of measured projection and the penalty term enforces the smoothing constraints of the projection image. The variance of projection data was chosen as the weight for the PWLS objective function and it determined the contribution of each measurement. An anisotropic quadratic form penalty that incorporates the gradient information of projection image was used to preserve edges during noise reduction. Low-Z target MV CBCT images were reconstructed by the FDK algorithm after each projection was processed by the PWLS smoothing. Results: Noise in low-Z target MV CBCT images were greatly suppressed after the PWLS projection smoothing, without noticeable sacrifice of the spatial resolution. Depending on the choice of smoothing parameter, the CNR of selected regions of interest in the PWLS processed low-dose low-Z target MV CBCT image can be higher than the corresponding high-dose image.Conclusion: The CNR of low-Z target MV CBCT images was substantially improved by using PWLS projection smoothing. The PWLS projection smoothing algorithm allows the reconstruction of high contrast low-Z target MV CBCT image with a total dose of as low as 2.3 cGy.

  5. Speckle noise suppression using a helix-free ferroelectric liquid crystal cell

    SciTech Connect (OSTI)

    Andreev, A L; Andreeva, T B; Kompanets, I N; Zalyapin, N V

    2014-12-31

    We have studied the method for suppressing speckle noise in patterns produced by a laser based on a fast-response electro-optical cell with a ferroelectric liquid crystal (FLC) in which helicoid is absent, i.e., compensated for. The character of smectic layer deformation in an electric field is considered along with the mechanism of spatially inhomogeneous phase modulation of a laser beam passing through the cell which is accompanied by the destruction of phase relations in the beam. Advantages of a helix-free FLC cell are pointed out as compared to helical crystal cells studied previously. (liquid crystal devices)

  6. Suppression of fiber modal noise induced radial velocity errors for bright emission-line calibration sources

    SciTech Connect (OSTI)

    Mahadevan, Suvrath; Halverson, Samuel; Ramsey, Lawrence; Venditti, Nick

    2014-05-01

    Modal noise in optical fibers imposes limits on the signal-to-noise ratio (S/N) and velocity precision achievable with the next generation of astronomical spectrographs. This is an increasingly pressing problem for precision radial velocity spectrographs in the near-infrared (NIR) and optical that require both high stability of the observed line profiles and high S/N. Many of these spectrographs plan to use highly coherent emission-line calibration sources like laser frequency combs and Fabry-Perot etalons to achieve precision sufficient to detect terrestrial-mass planets. These high-precision calibration sources often use single-mode fibers or highly coherent sources. Coupling light from single-mode fibers to multi-mode fibers leads to only a very low number of modes being excited, thereby exacerbating the modal noise measured by the spectrograph. We present a commercial off-the-shelf solution that significantly mitigates modal noise at all optical and NIR wavelengths, and which can be applied to spectrograph calibration systems. Our solution uses an integrating sphere in conjunction with a diffuser that is moved rapidly using electrostrictive polymers, and is generally superior to most tested forms of mechanical fiber agitation. We demonstrate a high level of modal noise reduction with a narrow bandwidth 1550 nm laser. Our relatively inexpensive solution immediately enables spectrographs to take advantage of the innate precision of bright state-of-the art calibration sources by removing a major source of systematic noise.

  7. kT/C noise: Covariance matrix calculation of instationary noise in time-varying systems

    E-Print Network [OSTI]

    Noé, Reinhold

    kT/C noise: Covariance matrix calculation of instationary noise in time-varying systems Reinhold kT/C noise is treated analytically, using explicit and implicit notations of differential equations to take into account high integrator bandwidth, slow switching and other methods to mediate kT/C noise

  8. Active noise canceling system for mechanically cooled germanium radiation detectors

    DOE Patents [OSTI]

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  9. Design fires for tunnel water mist suppression systems 

    E-Print Network [OSTI]

    Carvel, Ricky O

    Water mist systems are unable to suppress or control large fires, therefore the ‘design fire’ for a water mist system in a tunnel should not be specified in terms of peak heat release rate, but rather in terms of the ...

  10. Enabling Green Energy and Propulsion Systems via Direct Noise...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    GE propulsion systems Enabling Green Energy and Propulsion Systems via Direct Noise Computation PI Name: Umesh Paliath PI Email: paliath@ge.com Institution: GE Global Research...

  11. Noise isolation system for high-speed circuits

    DOE Patents [OSTI]

    McNeilly, D.R.

    1983-12-29

    A noise isolation circuit is provided that consists of a dual function bypass which confines high-speed switching noise to the component or circuit which generates it and isolates the component or circuit from high-frequency noise transients which may be present on the ground and power supply busses. A local circuit ground is provided which is coupled to the system ground by sufficient impedance to force the dissipation of the noise signal in the local circuit or component generating the noise. The dual function bypass network couples high-frequency noise signals generated in the local component or circuit through a capacitor to the local ground while isolating the component or circuit from noise signals which may be present on the power supply busses or system ground. The network is an effective noise isolating system and is applicable to both high-speed analog and digital circuits.

  12. Noise isolation system for high-speed circuits

    DOE Patents [OSTI]

    McNeilly, David R. (Maryville, TN)

    1986-01-01

    A noise isolation circuit is provided that consists of a dual function bypass which confines high-speed switching noise to the component or circuit which generates it and isolates the component or circuit from high-frequency noise transients which may be present on the ground and power supply busses. A local circuit ground is provided which is coupled to the system ground by sufficient impedance to force the dissipation of the noise signal in the local circuit or component generating the noise. The dual function bypass network couples high-frequency noise signals generated in the local component or circuit through a capacitor to the local ground while isolating the component or circuit from noise signals which may be present on the power supply busses or system ground. The network is an effective noise isolating system and is applicable to both high-speed analog and digital circuits.

  13. MMSE Noise Power and SNR Estimation for OFDM Systems

    E-Print Network [OSTI]

    Arslan, Hüseyin

    MMSE Noise Power and SNR Estimation for OFDM Systems Tevfik Y¨ucek and H¨useyin Arslan Department-- This paper proposes a minimum mean-square error (MMSE) filtering technique to estimate the noise power that takes into account the variation of the noise statistics across the orthogonal frequency division

  14. Enabling Green Energy and Propulsion Systems via Direct Noise...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Umesh Paliath, GE Global Research; Joe Insley, Argonne National Laboratory Enabling Green Energy and Propulsion Systems via Direct Noise Computation PI Name: Umesh Paliath PI...

  15. Circuit for echo and noise suppression of acoustic signals transmitted through a drill string

    DOE Patents [OSTI]

    Drumheller, D.S.; Scott, D.D.

    1993-12-28

    An electronic circuit for digitally processing analog electrical signals produced by at least one acoustic transducer is presented. In a preferred embodiment of the present invention, a novel digital time delay circuit is utilized which employs an array of First-in-First-out (FiFo) microchips. Also, a bandpass filter is used at the input to this circuit for isolating drill string noise and eliminating high frequency output. 20 figures.

  16. Circuit for echo and noise suppression of accoustic signals transmitted through a drill string

    DOE Patents [OSTI]

    Drumheller, Douglas S. (P.O. Box 676, Cedar Crest, NM 87008); Scott, Douglas D. (12911 Kachima Place N.E., Apt. A, Albuquerque, NM 37112)

    1993-01-01

    An electronic circuit for digitally processing analog electrical signals produced by at least one acoustic transducer is presented. In a preferred embodiment of the present invention, a novel digital time delay circuit is utilized which employs an array of First-in-First-out (FiFo) microchips. Also, a bandpass filter is used at the input to this circuit for isolating drill string noise and eliminating high frequency output.

  17. Environmental Noise and Nonlinear Relaxation in Biological Systems

    E-Print Network [OSTI]

    B. Spagnolo; D. Valenti; S. Spezia; L. Curcio; N. Pizzolato; A. A. Dubkov; A. Fiasconaro; D. Persano Adorno; P. Lo Bue; E. Peri; S. Colazza

    2011-12-17

    We analyse the effects of environmental noise in three different biological systems: (i) mating behaviour of individuals of \\emph{Nezara viridula} (L.) (Heteroptera Pentatomidae); (ii) polymer translocation in crowded solution; (iii) an ecosystem described by a Verhulst model with a multiplicative L\\'{e}vy noise.

  18. Feasibility and design of blast mitigation systems for naval applications using water mist fire suppression systems

    E-Print Network [OSTI]

    Kitchenka, Julie A

    2004-01-01

    The recent trend of using fine water mist systems to replace the legacy HALON- 1301 fire suppression systems warrants further study into other applications of the water mist systems. Preliminary research and investigation ...

  19. Concrete Dust Suppression System. Innovative Technology Summary Report

    SciTech Connect (OSTI)

    1998-12-01

    The improved technology is a water-based dust suppression system for controlling concrete dust generated by demolition equipment, in this case a demolition ram. This demonstration was performed to assess the effectiveness of this system to (1) minimize the amount of water used to suppress potentially contaminated dust, (2) focus the water spray on the dust-generating source and (3) minimize the dust cloud generated by the demolition activity. The technology successfully reduced the water required by a factor of eight compared to the traditional (baseline) method, controlled the dust generated, and permitted a reduction in the work force. The water spray can be focused at the ram point, but it is affected by wind. Prior to the use of this dust control system, dust generated by the demolition ram was controlled manually by spraying with fire hoses (the baseline technology). The improved technology is 18% less expensive than the baseline technology for the conditions and parameters of this demonstration, however, the automated system can save up to 80% versus the baseline whenever waste water treatment costs are considered. For demolishing one high-walled room and a long slab with a total of 413 m{sup 3} (14,580 ft{sup 3}) of concrete, the savings are $105,000 (waste water treatment included). The improved technology reduced the need for water consumption and treatment by about 88% which results in most of the savings.

  20. Testing for Chaos in Deterministic Systems with Noise

    E-Print Network [OSTI]

    Gottwald, Georg A.

    Testing for Chaos in Deterministic Systems with Noise Georg A. Gottwald School of Maths and Stats Guildford GU2 7XH, UK 24 November, 2004 Abstract Recently, we introduced a new test for distinguishing regular from chaotic dynamics in deterministic dynamical systems and argued that the test had cer- tain

  1. Reliability study of an emerging fire suppression system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Miller, David A.; Rossati, Lyric M.; Fritz, Nathan K.; Cournoyer, Michael E.; Granzow, Howard N.

    2015-02-07

    Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Plutonium gloveboxes are known to present harsh environmental conditions for polymer materials, these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. The primary component of interest in self-contained fire extinguishers is the nylon 6-6 machined tube that comprises the main body of the system.Thermo-mechanical modeling and characterization of nylon 6-6 for use in plutonium glovebox applications has been carried out. Data has been generated regarding property degradation leading to poor, or reduced, engineering performancemore »of nylon 6-6 components. In this study, nylon 6-6 tensile specimens conforming to the casing of self-contained fire extinguisher systems have been exposed to hydrochloric, nitric, and sulfuric acids. This information was used to predict the performance of a load bearing engineering component comprised of nylon 6-6 and designed to operate in a consistent manner over a specified time period. The study provides a fundamental understanding of the engineering performance of the fire suppression system and the effects of environmental degradation due to acid exposure on engineering performance. Data generated help identify the limitations of self-contained fire extinguishers. No critical areas of concern for plutonium glovebox applications of nylon 6-6 have been identified when considering exposure to mineral acid.« less

  2. Competition of noise sources in systems with delay: the role of multiple time scales

    E-Print Network [OSTI]

    Fournier, John J.F.

    (additive) noise can amplify vibrations via coherence resonance while random variation of delay can suppress, and experiments, with manufacturing issues and virtual machining via computational modeling discussed in detail in the context of randomness. Variation in material parameters leads to both additive and multiplicative noise

  3. Pressure suppression containment system for boiling water reactor

    DOE Patents [OSTI]

    Gluntz, Douglas M. (San Jose, CA); Nesbitt, Loyd B. (San Jose, CA)

    1997-01-01

    A system for suppressing the pressure inside the containment of a BWR following a postulated accident. A piping subsystem is provided which features a main process pipe that communicates the wetwell airspace to a connection point downstream of the guard charcoal bed in an offgas system and upstream of the main bank of delay charcoal beds which give extensive holdup to offgases. The main process pipe is fitted with both inboard and outboard containment isolation valves. Also incorporated in the main process pipe is a low-differential-pressure rupture disk which prevents any gas outflow in this piping whatsoever until or unless rupture occurs by virtue of pressure inside this main process pipe on the wetwell airspace side of the disk exceeding the design opening (rupture) pressure differential. The charcoal holds up the radioactive species in the noncondensable gas from the wetwell plenum by adsorption, allowing time for radioactive decay before the gas is vented to the environs.

  4. Pressure suppression containment system for boiling water reactor

    DOE Patents [OSTI]

    Gluntz, D.M.; Nesbitt, L.B.

    1997-01-21

    A system is disclosed for suppressing the pressure inside the containment of a BWR following a postulated accident. A piping subsystem is provided which features a main process pipe that communicates the wetwell airspace to a connection point downstream of the guard charcoal bed in an offgas system and upstream of the main bank of delay charcoal beds which give extensive holdup to offgases. The main process pipe is fitted with both inboard and outboard containment isolation valves. Also incorporated in the main process pipe is a low-differential-pressure rupture disk which prevents any gas outflow in this piping whatsoever until or unless rupture occurs by virtue of pressure inside this main process pipe on the wetwell airspace side of the disk exceeding the design opening (rupture) pressure differential. The charcoal holds up the radioactive species in the noncondensable gas from the wetwell plenum by adsorption, allowing time for radioactive decay before the gas is vented to the environs. 3 figs.

  5. Dry low combustion system with means for eliminating combustion noise

    DOE Patents [OSTI]

    Verdouw, Albert J.; Smith, Duane; McCormick, Keith; Razdan, Mohan K.

    2004-02-17

    A combustion system including a plurality of axially staged tubular premixers to control emissions and minimize combustion noise. The combustion system includes a radial inflow premixer that delivers the combustion mixture across a contoured dome into the combustion chamber. The axially staged premixers having a twist mixing apparatus to rotate the fluid flow and cause improved mixing without causing flow recirculation that could lead to pre-ignition or flashback.

  6. Reproducibility of electrochemical noise data from coated metal systems

    SciTech Connect (OSTI)

    Bierwagen, G.P.; Mills, D.J.; Tallman, D.E.; Skerry, B.S.

    1996-12-31

    The use of electrochemical noise (ECN) as a method to characterize the corrosion-protection properties of organic coatings on metal substrates was pioneered by Skerry and Eden, and since then has been used by others as a probe for coating metal corrosion studies. However, no statistical examination of the reproducibility of the data from such measurements has been published. In the data the authors present, they have done a systematic analysis of important experimental variables in such systems. They have examined the method for accuracy and reproducibility with respect to sample preparation, sample immersion, and metal substrate preparation. They have taken several marine coatings systems typical of US Navy use, prepared duplicate samples of coating metal systems, and examined them under the same immersion exposure. The variables they considered for reproducibility are paint application (in three-coat systems), metal panel preparation (grit-blasted steel), and immersion conditions. The authors present ECN data with respect to immersion time on the values of noise voltage standard deviation {sigma}{sub V}, noise current standard deviation {sigma}{sub I}, and the noise resistance R{sub n} as given by {sigma}{sub V}/{sigma}{sub I}. The variation among supposedly identical sample pairs in identical immersion monitored under identical conditions is presented. The statistics of the time records of the data are considered, and the variations with respect to specific coatings classes are also considered within the limits of the data. Based on these data, comments concerning ECN on coated metal systems as a predictive test method are presented along with special considerations that must be made to properly use the method for coating ranking and lifetime prediction.

  7. Stochastic dynamics of a delayed bistable system with multiplicative noise

    SciTech Connect (OSTI)

    Dung, Nguyen Tien E-mail: dungnt@fpt.edu.vn

    2014-05-15

    In this paper we investigate the properties of a delayed bistable system under the effect of multiplicative noise. We first prove the existence and uniqueness of the positive solution and show that its moments are uniformly bounded. Then, we study stochastic dynamics of the solution in long time, the lower and upper bounds for the paths and an estimate for the average value are provided.

  8. Shot noise in systems with semi-Dirac points

    SciTech Connect (OSTI)

    Zhai, Feng; Wang, Juan

    2014-08-14

    We calculate the ballistic conductance and shot noise of electrons through a two-dimensional stripe system (width W ? length L) with semi-Dirac band-touching points. We find that the ratio between zero-temperature noise power and mean current (the Fano factor) is highly anisotropic. When the transport is along the linear-dispersion direction and the Fermi energy is fixed at the semi-Dirac point, the Fano factor has a universal value F?=?0.179 while a minimum conductivity exists and scales with L{sup 1?2}. Along the parabolic dispersion direction, the Fano factor at the semi-Dirac point has a contact-independent limit exceeding 0.9, which varies weakly with L due to the common-path interference of evanescent waves. Our findings suggest a way to discern the type of band-touching points.

  9. Kramers turnover in class of thermodynamically open systems: Effect of interplay of nonlinearity and noises

    E-Print Network [OSTI]

    Shit, Anindita; Banik, Suman Kumar; Chaudhuri, Jyotipratim Ray

    2015-01-01

    A system-reservoir nonlinear coupling model has been proposed for a situation where the reservoir is nonlinearly driven by an external Gaussian stationary noise which exposes the system particles to a nonequilibrium environment. Apart from the internal thermal noise, the thermodynamically open system encounters two other noises that are multiplicative in nature. Langevin equation derived from the resulting composite system contains the essential features of the interplay between these noise processes. Based on the numerical simulation of the full model potential, we show that one can recover the turnover features of the Kramers dynamics even when the reservoir is modulated nonlinearly by an external noise.

  10. Efficient Methods of Clutter Suppression for Coexisting Land and Weather Clutter Systems

    E-Print Network [OSTI]

    Yýlmaz, Özgür

    1 Efficient Methods of Clutter Suppression for Coexisting Land and Weather Clutter Systems C¸ a and weather clutter signals is a common problem in many radar applications. Although the optimal method for land-weather clutter suppression is known, it is usually not amenable to implementation due

  11. Efficient Methods of Clutter Suppression for Coexisting Land and Weather Clutter Systems

    E-Print Network [OSTI]

    Candan, Cagatay

    Efficient Methods of Clutter Suppression for Coexisting Land and Weather Clutter Systems The removal of coexisting land and weather clutter signals is a common problem in many radar applications. Although the optimal method for land-weather clutter suppression is known, it is usually not amenable

  12. Dynamical systems modeling of Continuous Flash Suppression Daisuke Shimaoka

    E-Print Network [OSTI]

    Kaneko, Kunihiko

    : Binocular rivalry Adaptation Neural modeling a b s t r a c t Continuous Flash Suppression (CFS is considered to be involved in CFS, but does not reproduce CFS. We then extend the model by including of visibility observed in CFS. In addition, this model captured some defining characteristics of CFS

  13. The Availability of Logical Operation Induced by Dichotomous Noise for a Nonlinear Bistable System

    E-Print Network [OSTI]

    Yong Xu; Xiaoqin Jin; Huiqing Zhang; Tingting Yang

    2013-09-04

    Instead of a continuous system driven by Gaussian white noise, logical stochastic resonance will be investigated in a nonlinear bistable system with two thresholds driven by dichotomous noise, which shows a phenomenon different from Gaussian white noise. We can realize two parallel logical operations by simply adjusting the values of these two thresholds. Besides, to quantify the reliability of obtaining the correct logic output, we numerically calculate the success probability, and effects of dichotomous noise on the success probability are observed, these observations show that the reliability of realizing logical operation in the bistable system can be improved through optimizing parameters of dichotomous noise.

  14. Modeling noise induced resonance in an excitable system: An alternative approach

    E-Print Network [OSTI]

    Md. Nurujjaman

    2009-12-16

    Recently, it is observed [Md. Nurujjaman et al, Phy. Rev. E \\textbf{80}, 015201 (R) (2009)] that in an excitable system, one can maintain noise induced coherency in the coherence resonance by blocking the destructive effect of the noise on the system at higher noise level. This phenomenon of constant coherence resonance (CCR) cannot be explained by the existing way of simulation of the model equations of an excitable system with added noise. In this paper, we have proposed a general model which explains the noise induced resonance phenomenon CCR as well as coherence resonance (CR) and stochastic resonance (SR). The simulation has been carried out considering the basic mechanism of noise induced resonance phenomena: noise only perturbs the system control parameter to excite coherent oscillations, taking proper precautions so that the destructive effect of noise does not affect the system. In this approach, the CR has been obtained from the interference between the system output and noise, and the SR has been obtained by adding noise and a subthreshold signal. This also explains the observation of the frequency shift of coherent oscillations in the CCR with noise level.

  15. Investigating Operating System Noise in Extreme-Scale High-Performance Computing Systems using Simulation

    SciTech Connect (OSTI)

    Engelmann, Christian

    2013-01-01

    Hardware/software co-design for future-generation high-performance computing (HPC) systems aims at closing the gap between the peak capabilities of the hardware and the performance realized by applications (application-architecture performance gap). Performance profiling of architectures and applications is a crucial part of this iterative process. The work in this paper focuses on operating system (OS) noise as an additional factor to be considered for co-design. It represents the first step in including OS noise in HPC hardware/software co-design by adding a noise injection feature to an existing simulation-based co-design toolkit. It reuses an existing abstraction for OS noise with frequency (periodic recurrence) and period (duration of each occurrence) to enhance the processor model of the Extreme-scale Simulator (xSim) with synchronized and random OS noise simulation. The results demonstrate this capability by evaluating the impact of OS noise on MPI_Bcast() and MPI_Reduce() in a simulated future-generation HPC system with 2,097,152 compute nodes.

  16. Method and system for modulation of gain suppression in high average power laser systems

    DOE Patents [OSTI]

    Bayramian, Andrew James (Manteca, CA)

    2012-07-31

    A high average power laser system with modulated gain suppression includes an input aperture associated with a first laser beam extraction path and an output aperture associated with the first laser beam extraction path. The system also includes a pinhole creation laser having an optical output directed along a pinhole creation path and an absorbing material positioned along both the first laser beam extraction path and the pinhole creation path. The system further includes a mechanism operable to translate the absorbing material in a direction crossing the first laser beam extraction laser path and a controller operable to modulate the second laser beam.

  17. Biologically-based signal processing system applied to noise removal for signal extraction

    DOE Patents [OSTI]

    Fu, Chi Yung; Petrich, Loren I.

    2004-07-13

    The method and system described herein use a biologically-based signal processing system for noise removal for signal extraction. A wavelet transform may be used in conjunction with a neural network to imitate a biological system. The neural network may be trained using ideal data derived from physical principles or noiseless signals to determine to remove noise from the signal.

  18. Performance analysis of interference suppression techniques for multiple antenna systems

    E-Print Network [OSTI]

    Amihood, Patrick

    2007-01-01

    in Electrical Engineering (Communication Theory and Systems)in Electrical Engineering (Communication Theory and Systems)USA M.S. , Electrical Engineering (Communication Theory and

  19. Separation of noise from distortion for high-speed optical fiber system link budgeting

    E-Print Network [OSTI]

    Hui, Rongqing; Vaziri, M.; Zhou, J.; O'Sullivan, M.

    1999-07-01

    In optical transmission systems and networks with in-line optical amplifiers, system performance degradations caused by random noise and optical path distortions are usually thought to he inseparable, which makes link performance evaluation...

  20. Dual-mode self-validating resistance/Johnson noise thermometer system

    DOE Patents [OSTI]

    Shepard, Robert L. (Oak Ridge, TN); Blalock, Theron V. (Knoxville, TN); Roberts, Michael J. (Knoxville, TN)

    1993-01-01

    A dual-mode Johnson noise and DC resistance thermometer capable of use in control systems where prompt indications of temperature changes and long term accuracy are needed. A resistance-inductance-capacitance (RLC) tuned circuit produces a continuous voltage signal for Johnson noise temperature measurement. The RLC circuit provides a mean-squared noise voltage that depends only on the capacitance used and the temperature of the sensor. The sensor has four leads for simultaneous coupling to a noise signal processor and to a DC resistance signal processor.

  1. Optimized pulse sequences for suppressing unwanted transitions in quantum systems

    E-Print Network [OSTI]

    C. A. Schroeder; G. S. Agarwal

    2010-10-25

    We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. \\textbf{98}, 100504 (2007)] in the context of inhibition of environmental dephasing effects is optimal. We derive exact results for inhibiting the transitions and confirm the results numerically. We posit a very significant improvement by usage of the Uhrig sequence over an equidistant sequence in decoupling a quantum system from unwanted transitions. The physics of inhibition is the destructive interference between transition amplitudes before and after each pulse.

  2. Optimized pulse sequences for suppressing unwanted transitions in quantum systems

    SciTech Connect (OSTI)

    Schroeder, C. A.; Agarwal, G. S. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St. Norman, Oklahoma 73019 (United States); Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)

    2011-01-15

    We investigate the nature of the pulse sequence so that unwanted transitions in quantum systems can be inhibited optimally. For this purpose we show that the sequence of pulses proposed by Uhrig [Phys. Rev. Lett. 98, 100504 (2007)] in the context of inhibition of environmental dephasing effects is optimal. We derive exact results for inhibiting the transitions and confirm the results numerically. We posit a very significant improvement by usage of the Uhrig sequence over an equidistant sequence in decoupling a quantum system from unwanted transitions. The physics of inhibition is the destructive interference between transition amplitudes before and after each pulse.

  3. Noise Reduction Efforts for the ALS Infrared Beamlines

    SciTech Connect (OSTI)

    Scarvie, Tom; Andresen, Nord; Baptiste, Ken; Byrd, John; Chin, Mike; Martin, Michael; McKinney, Wayne; Steier, Christoph

    2004-05-12

    The quality of infrared microscopy and spectroscopy data collected at synchrotron based sources is strongly dependent on signal-to-noise. We have successfully identified and suppressed several noise sources affecting Beamlines 1.4.2, 1.4.3, and 1.4.4 at the Advanced Light Source (ALS), resulting in a significant increase in the quality of FTIR spectra obtained. In this paper, we present our methods of noise source analysis, the negative effect of noise on the infrared beam quality, and the techniques used to reduce the noise. These include reducing the phase noise in the storage ring radio-frequency (RF) system, installing an active mirror feedback system, analyzing and changing physical mounts to better isolate portions of the beamline optics from low-frequency environmental noise, and modifying the input signals to the main ALS RF system. We also discuss the relationship between electron beam energy oscillations at a point of dispersion and infrared beamline noise.

  4. Award ER25844: Minimizing System Noise Effects for Extreme-Scale Scientific Simulation Through Function Delegation

    SciTech Connect (OSTI)

    Lumsdaine, Andrew

    2012-11-20

    In software running on distributed computing clusters, time spent on communication between nodes in the cluster can be a significant portion of the overall computation time; background operating system tasks and other computational ?noise? on the nodes of the system can have a significant impact on the amount of time this communication takes, especially on large systems. The research completed in this period has improved understanding of when such noise will have a significant impact. Specifically, it was demonstrated that not just noise on the nodes, but also noise on the network between nodes can have a significant impact on computation time. It was also demonstrated that noise patterns matter more than noise intensity: very regular noise can cause less disruption than lighter (on average) but less regular noise. It was also demonstrated that the effect of noise is more prominent as the speed of the network between nodes is increased. Furthermore, a tracing tool, Netgauge, was improved via our work, and a system simulator, LogGOPSim, was developed; they can be used by application developers to improve performance of their program and by system designers to mitigate the effects of noise by adjusting the noise characteristics of the operating system. Both have been made freely available as open source programs. In the course of developing these tools, we demonstrated weaknesses in existing methodologies for modeling communication, and we introduced a more detailed model, LogGOPS, for simulating systems. Not only were the deleterious effects of noise explored but we have also offered solutions. Our studies of simulations of system noise have led to specific recommendations on tuning systems to mitigate noise. We have also improved existing approaches to mitigating noise. ?Non-blocking collective communication? avoids the effects of noise by letting communication continue simultaneously with computation (thus being ?non-blocking?), so that the delays in communication introduced by noise have a smaller impact on overall computation time. Potentially, noise can be reduced much further by ?offloading? communication tasks to a separate processing element than the operating system is using. We have improved our library LibNBC, which provides an implementation of non-blocking collectives, via this work. During this research, our proposal to include non-blocking collectives (which used LibNBC as a reference implementation) in the upcoming MPI-3 standard was accepted. As MPI is a ubiquitous and important standard for communication in parallel computing, this demonstrates a certain acceptance of the practicality and desirability of non-blocking collectives. Now that non-blocking collectives are a part of the standard we can expect to see optimized platform-specific implementations of non-blocking collectives. Also as part of this work we have also developed a language GOAL (Global Operation Assembly Language) that can be used as a starting point for defining languages to express optimized communication algorithms.

  5. Memorandum, Managed Phase Out of Halon Fixed Fire Suppression Systems- May 5, 1993

    Broader source: Energy.gov [DOE]

    The purpose of this memorandum is to provide additional interim departmental criteria on the management of the reduction and potential elimination of Halon fire extinguishing systems within the Department of Energy (DOE). This memorandum supplements the joint Office of Safety and Quality Assurance/Office of Projects and Facilities Management memorandum of September 27, 1990, in which guidance was provided on the installation of new Halon 1301 fixed fire suppression systems and halon 1211 portable fire extinguishers.

  6. Noise, Oscillators and Algebraic Randomness From Noise in Communication Systems to Number Theory. pp. 137-155 ; M. Planat, ed., Lecture Notes in Physics, Vol. 550, Springer (Berlin) 2000.

    E-Print Network [OSTI]

    Chapeau-Blondeau, François

    Noise, Oscillators and Algebraic Randomness ­ From Noise in Communication Systems to Number Theory resonance and the benefit of noise in nonlinear systems Fran¸cois Chapeau-Blondeau Laboratoire d effect wherein the noise turns out to be beneficial to the transmission or detection of an information

  7. System and method for motor fault detection using stator current noise cancellation

    DOE Patents [OSTI]

    Zhou, Wei (Los Angeles, CA); Lu, Bin (Kenosha, WI); Nowak, Michael P. (Menomonee Falls, WI); Dimino, Steven A. (Wauwatosa, WI)

    2010-12-07

    A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to acquire at least on additional set of real-time operating current data from the motor during operation, redefine the noise component present in each additional set of real-time operating current data, and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

  8. Noise Power and SNR Estimation for OFDM Based Wireless Communication Systems

    E-Print Network [OSTI]

    Arslan, HĂĽseyin

    Noise Power and SNR Estimation for OFDM Based Wireless Communication Systems H¨useyin Arslan for measuring the quality of the channel. Then, the system parameters are changed adaptively based of information transfer can be used to maximize system resource utilization with high quality of user experience

  9. Statistical model based iterative reconstruction (MBIR) in clinical CT systems: Experimental assessment of noise performance

    SciTech Connect (OSTI)

    Li, Ke; Tang, Jie; Chen, Guang-Hong

    2014-04-15

    Purpose: To reduce radiation dose in CT imaging, the statistical model based iterative reconstruction (MBIR) method has been introduced for clinical use. Based on the principle of MBIR and its nonlinear nature, the noise performance of MBIR is expected to be different from that of the well-understood filtered backprojection (FBP) reconstruction method. The purpose of this work is to experimentally assess the unique noise characteristics of MBIR using a state-of-the-art clinical CT system. Methods: Three physical phantoms, including a water cylinder and two pediatric head phantoms, were scanned in axial scanning mode using a 64-slice CT scanner (Discovery CT750 HD, GE Healthcare, Waukesha, WI) at seven different mAs levels (5, 12.5, 25, 50, 100, 200, 300). At each mAs level, each phantom was repeatedly scanned 50 times to generate an image ensemble for noise analysis. Both the FBP method with a standard kernel and the MBIR method (Veo{sup ®}, GE Healthcare, Waukesha, WI) were used for CT image reconstruction. Three-dimensional (3D) noise power spectrum (NPS), two-dimensional (2D) NPS, and zero-dimensional NPS (noise variance) were assessed both globally and locally. Noise magnitude, noise spatial correlation, noise spatial uniformity and their dose dependence were examined for the two reconstruction methods. Results: (1) At each dose level and at each frequency, the magnitude of the NPS of MBIR was smaller than that of FBP. (2) While the shape of the NPS of FBP was dose-independent, the shape of the NPS of MBIR was strongly dose-dependent; lower dose lead to a “redder” NPS with a lower mean frequency value. (3) The noise standard deviation (?) of MBIR and dose were found to be related through a power law of ????(dose){sup ??} with the component ? ? 0.25, which violated the classical ????(dose){sup ?0.5} power law in FBP. (4) With MBIR, noise reduction was most prominent for thin image slices. (5) MBIR lead to better noise spatial uniformity when compared with FBP. (6) A composite image generated from two MBIR images acquired at two different dose levels (D1 and D2) demonstrated lower noise than that of an image acquired at a dose level of D1+D2. Conclusions: The noise characteristics of the MBIR method are significantly different from those of the FBP method. The well known tradeoff relationship between CT image noise and radiation dose has been modified by MBIR to establish a more gradual dependence of noise on dose. Additionally, some other CT noise properties that had been well understood based on the linear system theory have also been altered by MBIR. Clinical CT scan protocols that had been optimized based on the classical CT noise properties need to be carefully re-evaluated for systems equipped with MBIR in order to maximize the method's potential clinical benefits in dose reduction and/or in CT image quality improvement.

  10. Resonant activation in a colored multiplicative thermal noise driven closed system

    SciTech Connect (OSTI)

    Ray, Somrita; Bag, Bidhan Chandra; Mondal, Debasish

    2014-05-28

    In this paper, we have demonstrated that resonant activation (RA) is possible even in a thermodynamically closed system where the particle experiences a random force and a spatio-temporal frictional coefficient from the thermal bath. For this stochastic process, we have observed a hallmark of RA phenomena in terms of a turnover behavior of the barrier-crossing rate as a function of noise correlation time at a fixed noise variance. Variance can be fixed either by changing temperature or damping strength as a function of noise correlation time. Our another observation is that the barrier crossing rate passes through a maximum with increase in coupling strength of the multiplicative noise. If the damping strength is appreciably large, then the maximum may disappear. Finally, we compare simulation results with the analytical calculation. It shows that there is a good agreement between analytical and numerical results.

  11. Noise temperature improvement for magnetic fusion plasma millimeter wave imaging systems

    SciTech Connect (OSTI)

    Lai, J.; Domier, C. W.; Luhmann, N. C.

    2014-03-15

    Significant progress has been made in the imaging and visualization of magnetohydrodynamic and microturbulence phenomena in magnetic fusion plasmas [B. Tobias et al., Plasma Fusion Res. 6, 2106042 (2011)]. Of particular importance have been microwave electron cyclotron emission imaging and microwave imaging reflectometry systems for imaging T{sub e} and n{sub e} fluctuations. These instruments have employed heterodyne receiver arrays with Schottky diode mixer elements directly connected to individual antennas. Consequently, the noise temperature has been strongly determined by the conversion loss with typical noise temperatures of ?60?000 K. However, this can be significantly improved by making use of recent advances in Monolithic Microwave Integrated Circuit chip low noise amplifiers to insert a pre-amplifier in front of the Schottky diode mixer element. In a proof-of-principle design at V-Band (50–75 GHz), significant improvement of noise temperature from the current 60?000 K to measured 4000 K has been obtained.

  12. System and method that suppresses intensity fluctuations for free space high-speed optical communication

    DOE Patents [OSTI]

    Berman, Gennady P. (Los Alamos, NM); Bishop, Alan R. (Los Alamos, NM); Nguyen, Dinh C. (Los Alamos, NM); Chernobrod, Boris M. (Santa Fe, NM); Gorshkov, Vacheslav N. (Kiev, UA)

    2009-10-13

    A high-speed (Gbps), free space optical communication system is based on spectral encoding of radiation from a wide band light source, such as a laser. By using partially coherent laser beams in combination with a relatively slow photosensor, scintillations can be suppressed by orders of magnitude for distances of more than 10 km. To suppress the intensity fluctuations due to atmospheric turbulence, a source with partial transverse coherence in combination with slow response time photodetector is used. Information is encoded in the spectral domain of a wideband optical source by modulation of spectral amplitudes. A non-coherent light source with wide spectrum (an LED, for example) may be used for high-speed communication over short (less than about a mile) distances.

  13. NO.sub.x catalyst and method of suppressing sulfate formation in an exhaust purification system

    DOE Patents [OSTI]

    Balmer-Millar, Mari Lou (Chillicothe, IL); Park, Paul W. (Peoria, IL); Panov, Alexander G. (Peoria, IL)

    2007-06-26

    The activity and durability of a zeolite lean-burn NOx catalyst can be increased by loading metal cations on the outer surface of the zeolite. However, the metal loadings can also oxidize sulfur dioxide to cause sulfate formation in the exhaust. The present invention is a method of suppressing sulfate formation in an exhaust purification system including a NO.sub.x catalyst. The NO.sub.x catalyst includes a zeolite loaded with at least one metal. The metal is selected from among an alkali metal, an alkaline earth metal, a lanthanide metal, a noble metal, and a transition metal. In order to suppress sulfate formation, at least a portion of the loaded metal is complexed with at least one of sulfate, phosphate, and carbonate.

  14. Development of NS-TACSR with extremely suppressed aeolian noise and its application to 500 kV overhead transmission lines

    SciTech Connect (OSTI)

    Tsujimoto, K.; Furukawa, S. (Kansai Electric Power Co., Inc., Osaka (Japan)); Shimojima, K.; Yamamoto, K. (Hitachi Cable, Ltd., Hitachi (JP))

    1991-10-01

    Recently in Japan, with the unprecedented advance of residential area development in the suburbs of large cities, it has become quite difficult to secure the routes of EHV transmission lines from nuclear power plants in remote places to the suburbs of large cities, urging resolution of environmental problems related to transmission lines. In Japan, aerodynamic sound produced by conductors and insulators frequently caused noise problems. Having an opportunity of constructing a 500 kV transmission line through a residential are, we made a research to resolve this noise problem. This paper describes the characteristics of aeolian noise and preventive measures against it.

  15. How Quantum Computers Fail: Quantum Codes, Correlations in Physical Systems, and Noise Accumulation

    E-Print Network [OSTI]

    Kalai, Gil

    How Quantum Computers Fail: Quantum Codes, Correlations in Physical Systems, and Noise Accumulation, much of modern cryptography, as well as security in computer systems for finance and commerce are based Dedicated to the memory of Itamar Pitowsky Abstract The feasibility of computationally superior quantum

  16. Report of the final configuration of the Johnson Noise Thermometry System

    SciTech Connect (OSTI)

    Britton, Jr., Charles L.; Ezell, N. Dianne Bull; Roberts, Michael

    2014-02-01

    This document is a report on the final box and software configuration of the Johnson Noise Thermometry System being developed at ORNL. Much of this has been reported previously so that this report will be a systems-level summary of those reports, In addition we will describe some of the issues encountered during development.

  17. STUDY OF THE MTC ESTIMATION BY NOISE ANALYSIS IN 2-D HETEROGENEOUS SYSTEMS

    E-Print Network [OSTI]

    Demazičre, Christophe

    STUDY OF THE MTC ESTIMATION BY NOISE ANALYSIS IN 2-D HETEROGENEOUS SYSTEMS C. DEMAZIČRE, I. PÁZSIT and Pázsit, 2002a). Nevertheless, this previous study only investigated 1-D one-group homogeneous systems. We propose here to perform a substantially more advanced study of the same problem in 2-D two-group diffusion

  18. Geant4 Model Validation of Compton Suppressed System for Process monitoring of Spent Fuel

    SciTech Connect (OSTI)

    Bender, Sarah; Unlu, Kenan; Orton, Christopher R.; Schwantes, Jon M.

    2013-05-01

    Nuclear material accountancy is of continuous concern for the regulatory, safeguards, and verification communities. In particular, spent nuclear fuel reprocessing facilities pose one of the most difficult accountancy challenges: monitoring highly radioactive, fluid sample streams in near real-time. The Multi-Isotope Process monitor will allow for near-real-time indication of process alterations using passive gamma-ray detection coupled with multivariate analysis techniques to guard against potential material diversion or to enhance domestic process monitoring. The Compton continuum from the dominant 661.7 keV 137Cs fission product peak obscures lower energy lines which could be used for spectral and multivariate analysis. Compton suppression may be able to mitigate the challenges posed by the high continuum caused by scattering. A Monte Carlo simulation using the Geant4 toolkit is being developed to predict the expected suppressed spectrum from spent fuel samples to estimate the reduction in the Compton continuum. Despite the lack of timing information between decay events in the particle management of Geant4, encouraging results were recorded utilizing only the information within individual decays without accounting for accidental coincidences. The model has been validated with single and cascade decay emitters in two steps: as an unsuppressed system and with suppression activated. Results of the Geant4 model validation will be presented.

  19. Cascaded systems analysis of noise reduction algorithms in dual-energy imaging

    SciTech Connect (OSTI)

    Richard, Samuel; Siewerdsen, Jeffrey H. [Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada); Ontario Cancer Institute, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada) and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)

    2008-02-15

    An important aspect of dual-energy (DE) x-ray image decomposition is the incorporation of noise reduction techniques to mitigate the amplification of quantum noise. This article extends cascaded systems analysis of imaging performance to DE imaging systems incorporating linear noise reduction algorithms. A general analytical formulation of linear DE decomposition is derived, with weighted log subtraction and several previously reported noise reduction algorithms emerging as special cases. The DE image noise-power spectrum (NPS) and modulation transfer function (MTF) demonstrate that noise reduction algorithms impart significant, nontrivial effects on the spatial-frequency-dependent transfer characteristics which do not cancel out of the noise-equivalent quanta (NEQ). Theoretical predictions were validated in comparison to the measured NPS and MTF. The resulting NEQ was integrated with spatial-frequency-dependent task functions to yield the detectability index, d{sup '}, for evaluation of DE imaging performance using different decomposition algorithms. For a 3 mm lung nodule detection task, the detectability index varied from d{sup '}<1 (i.e., nodule barely visible) in the absence of noise reduction to d{sup '}>2.5 (i.e., nodule clearly visible) for ''anti-correlated noise reduction'' (ACNR) or ''simple-smoothing of the high-energy image'' (SSH) algorithms applied to soft-tissue or bone-only decompositions, respectively. Optimal dose allocation (A{sup *}, the fraction of total dose delivered in the low-energy projection) was also found to depend on the choice of noise reduction technique. At fixed total dose, multi-function optimization suggested a significant increase in optimal dose allocation from A{sup *}=0.32 for conventional log subtraction to A{sup *}=0.79 for ACNR and SSH in soft-tissue and bone-only decompositions, respectively. Cascaded systems analysis extended to the general formulation of DE image decomposition provided an objective means of investigating DE imaging performance across a broad range of acquisition and decomposition algorithms in a manner that accounts for the spatial-frequency-dependent imaging task.

  20. Minimizing System Noise Effects For Extreme-Scale Scientific Simulation Through Function Delegation

    SciTech Connect (OSTI)

    Dongarra, Jack J.; Bosilca, George

    2013-06-11

    The primary goal of the Minimizing System Noise Effects For Extreme-Scale Scientific Simulation through Function Delegation project is to eliminate or at best strongly minimize the impact of the noise introduced by the operating system, during large scale parallel applications runs. Collective communication operations are a basic building block for parallel programing models and scientific applications. These operations often dominate execution time of applications and tend to limit their scalability. In order to address this challenge, we evaluated different strategies to adapt the collective communications underlying topologies to the hardware architecture in order to provide increased levels of performance to the parallel applications.

  1. Shot noise in resonant tunneling through a zero-dimensional state with a complex energy spectrum A. Nauen,* F. Hohls, J. Konemann, and R. J. Haug

    E-Print Network [OSTI]

    Hohls, Frank

    Shot noise in resonant tunneling through a zero-dimensional state with a complex energy spectrum A; published 30 March 2004 We investigate the noise properties of a GaAs /AlxGa1 xAs resonant discuss the suppression of the shot noise in the framework of a coupled two-state system. For large bias

  2. System and method for bearing fault detection using stator current noise cancellation

    DOE Patents [OSTI]

    Zhou, Wei (Los Angeles, CA); Lu, Bin (Kenosha, WI); Habetler, Thomas G. (Snellville, GA); Harley, Ronald G. (Lawrenceville, GA); Theisen, Peter J. (West Bend, WI)

    2010-08-17

    A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to repeatedly receive real-time operating current data from the operating motor and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

  3. Module Placement for Power Supply Noise and Wire Congestion Avoidance in 3D Packaging

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    Module Placement for Power Supply Noise and Wire Congestion Avoidance in 3D Packaging Jacob Minz congestion minimization for 3D packaging. We employ decoupling capacitance insertion for noise suppression and 3D global routing for congestion avoidance. I. INTRODUCTION The m e potential of System-On-Package

  4. A feedback control strategy for the airfoil system under non-Gaussian colored noise excitation

    SciTech Connect (OSTI)

    Huang, Yong E-mail: taogang@njust.edu.cn; Tao, Gang E-mail: taogang@njust.edu.cn

    2014-09-01

    The stability of a binary airfoil with feedback control under stochastic disturbances, a non-Gaussian colored noise, is studied in this paper. First, based on some approximated theories and methods the non-Gaussian colored noise is simplified to an Ornstein-Uhlenbeck process. Furthermore, via the stochastic averaging method and the logarithmic polar transformation, one dimensional diffusion process can be obtained. At last by applying the boundary conditions, the largest Lyapunov exponent which can determine the almost-sure stability of the system and the effective region of control parameters is calculated.

  5. Signal processing method and system for noise removal and signal extraction

    DOE Patents [OSTI]

    Fu, Chi Yung (San Francisco, CA); Petrich, Loren (Lebanon, OR)

    2009-04-14

    A signal processing method and system combining smooth level wavelet pre-processing together with artificial neural networks all in the wavelet domain for signal denoising and extraction. Upon receiving a signal corrupted with noise, an n-level decomposition of the signal is performed using a discrete wavelet transform to produce a smooth component and a rough component for each decomposition level. The n.sup.th level smooth component is then inputted into a corresponding neural network pre-trained to filter out noise in that component by pattern recognition in the wavelet domain. Additional rough components, beginning at the highest level, may also be retained and inputted into corresponding neural networks pre-trained to filter out noise in those components also by pattern recognition in the wavelet domain. In any case, an inverse discrete wavelet transform is performed on the combined output from all the neural networks to recover a clean signal back in the time domain.

  6. Randomness and Noise in Information Systems Hongchao Zhou

    E-Print Network [OSTI]

    Bruck, Jehoshua (Shuki)

    in real research. He has also devoted a great deal of time and energy to my personal growth. I feel with in the Molecular Programming Project. I was very fortunate to work with these smart people, and enjoyed #12;v all molecular systems, where randomness plays important and distinct roles. Motivated by applications

  7. Cross-correlation spin noise spectroscopy of heterogeneous interacting spin systems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Roy, Dibyendu; Yang, Luyi; Crooker, Scott A.; Sinitsyn, Nikolai A.

    2015-04-30

    Interacting multi-component spin systems are ubiquitous in nature and in the laboratory. As such, investigations of inter-species spin interactions are of vital importance. Traditionally, they are studied by experimental methods that are necessarily perturbative: e.g., by intentionally polarizing or depolarizing one spin species while detecting the response of the other(s). Here, we describe and demonstrate an alternative approach based on multi-probe spin noise spectroscopy, which can reveal inter-species spin interactions - under conditions of strict thermal equilibrium - by detecting and cross-correlating the stochastic fluctuation signals exhibited by each of the constituent spin species. Specifically, we consider a two-component spinmore »ensemble that interacts via exchange coupling, and we determine cross-correlations between their intrinsic spin fluctuations. The model is experimentally confirmed using “two-color” optical spin noise spectroscopy on a mixture of interacting Rb and Cs vapors. Noise correlations directly reveal the presence of inter-species spin exchange, without ever perturbing the system away from thermal equilibrium. These non-invasive and noise-based techniques should be generally applicable to any heterogeneous spin system in which the fluctuations of the constituent components are detectable.« less

  8. The Dynamics of Bistable Switching Behavior in Limit Cycle Systems with Additive Noise

    E-Print Network [OSTI]

    Michael A. Schwemmer; Jay M. Newby

    2015-01-23

    Additive noise is known to produce counter-intuitive behaviors in nonlinear dynamical systems. Previously, it was shown that systems with a deterministic limit cycle can display bistable switching between metastable states in the presence of asymmetric additive white noise. Here, we systematically analyze the dynamics of this bistable behavior and show how the vector field away from the limit cycle influences the rate and directionality of the bistable switching. Using stochastic phase reduction methods, we identify mechanisms underlying different rates of switching and predict when the system will rotate in the opposite direction of the deterministic limit cycle. Thus, this work presents an alternative mechanism for generating a range of bistable switch-like behaviors that have been observed in a number of physical systems.

  9. Excitable systems with noise and delay with applications to control: renewal theory approach

    E-Print Network [OSTI]

    Andrey Pototsky; Natalia Janson

    2007-12-03

    We present an approach for the analytical treatment of excitable systems with noise-induced dynamics in the presence of time delay. An excitable system is modeled as a bistable system with a time delay, while another delay enters as a control term taken after [Pyragas 1992] as a difference between the current system state and its state "tau" time units before. This approach combines the elements of renewal theory to estimate the essential features of the resulting stochastic process as functions of the parameters of the controlling term.

  10. Noise-induced multistability in chemical systems: Discrete vs Continuum modeling

    E-Print Network [OSTI]

    Andrew Duncan; Shuohao Liao; Tomas Vejchodsky; Radek Erban; Ramon Grima

    2014-07-31

    The noisy dynamics of chemical systems is commonly studied using either the chemical master equation (CME) or the chemical Fokker-Planck equation (CFPE). The latter is a continuum approximation of the discrete CME approach. We here show that the CFPE may fail to capture the CME's prediction of noise-induced multistability. In particular we find a simple chemical system for which the CME's marginal probability distribution changes from unimodal to multimodal as the system-size decreases below a critical value, while the CFPE's marginal probability distribution is unimodal for all physically meaningful system sizes.

  11. Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

    SciTech Connect (OSTI)

    Qiu, Haodong; Wang, Hong; Ke, Feixiang

    2014-06-23

    The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

  12. Modulating resonance behaviors by noise recycling in bistable systems with time delay

    SciTech Connect (OSTI)

    Sun, Zhongkui Xu, Wei; Yang, Xiaoli; Xiao, Yuzhu

    2014-06-01

    In this paper, the impact of noise recycling on resonance behaviors is studied theoretically and numerically in a prototypical bistable system with delayed feedback. According to the interior cooperating and interacting activity of noise recycling, a theory has been proposed by reducing the non-Markovian problem into a two-state model, wherein both the master equation and the transition rates depend on not only the current state but also the earlier two states due to the recycling lag and the feedback delay. By virtue of this theory, the formulae of the power spectrum density and the linear response function have been found analytically. And the theoretical results are well verified by numerical simulations. It has been demonstrated that both the recycling lag and the feedback delay play a crucial role in the resonance behaviors. In addition, the results also suggest an alternative scheme to modulate or control the coherence or stochastic resonance in bistable systems with time delay.

  13. The emission of electromagnetic radiation from a quantum system interacting with an external noise: A general result

    E-Print Network [OSTI]

    S. Donadi; A. Bassi

    2015-01-29

    We compute the spectrum of emitted radiation by a generic quantum system interacting with an external classic noise. Our motivation is to understand this phenomenon within the framework of collapse models. However the computation is general and applies practically to any situation where a quantum system interacts with a noise. The computation is carried out at a perturbative level. This poses problems concerning the correct way of performing the analysis, as repeatedly discussed in the literature. We will clarify also this issue.

  14. Spatial resolution, signal-to-noise and information capacity of linear imaging systems

    E-Print Network [OSTI]

    Gureyev, Timur

    2015-01-01

    A simple model for image formation in linear shift-invariant systems is considered, in which both the detected signal and the noise variance are almost constant over distances comparable with the width of the point-spread function of the system. It is shown that within the constraints of this model, the square of the signal-to-noise ratio is always proportional to the "volume" of the spatial resolution unit. The ratio of these two quantities divided by the incident density of the imaging particles (e.g. photons) represents a dimensionless invariant of the imaging system, which was previously termed the intrinsic imaging quality. This invariant is related to the notion of information capacity of imaging and communication systems as previously considered by Shannon, Gabor and others. It is demonstrated that the information capacity expressed in bits cannot exceed the total number of imaging particles utilised in the system. These results are then applied to a simple generic model of quantitative imaging and ana...

  15. Error-suppression by energy-gap protection for quantum computation in open systems

    E-Print Network [OSTI]

    Zhou, Xiang-Yu (Xiang-Yu Leo)

    2014-01-01

    Adiabatic Quantum Computation, while attractive due to its "hands-off" approach and intrinsic tolerance of noise, has not been shown to be fully fault-tolerant in a satisfying manner. The protection of the evolution from ...

  16. A proposed system to automatically control audio sound-to-noise levels 

    E-Print Network [OSTI]

    Neinast, Gary Strickland

    1957-01-01

    for the degree oi' MASTER OP SCIENCE August 1957 Major Sub]eot'f Eleotrioal Engineering A PROPOSED SYSTEM TO AUTOMATICALLY CONTROL AUDIO SOUND-TO-NOISE LEVELS k Thesis QARY S. NEINAST Approved as to style and content by& islay a FBNR o 0 ee e epsx' ne... fxequency shown. This is the sero decibel level that 1s produced by a pure tone of 1000 cycles pex second at an intensity of . 0002 dynes per square centimeter. ~loudas . The Ieudaess of a sousd I ~ the asouut ef feeling ox sensation produced...

  17. Wind Turbine Generator System Acoustic Noise Test Report for the Gaia Wind 11-kW Wind Turbine

    SciTech Connect (OSTI)

    Huskey, A.

    2011-11-01

    This report details the acoustic noise test conducted on the Gaia-Wind 11-kW wind turbine at the National Wind Technology Center. The test turbine is a two- bladed, downwind wind turbine with a rated power of 11 kW. The test turbine was tested in accordance with the International Electrotechnical Commission standard, IEC 61400-11 Ed 2.1 2006-11 Wind Turbine Generator Systems -- Part 11 Acoustic Noise Measurement Techniques.

  18. SPEECH ENHANCEMENT IN CAR NOISE ENVIRONMENT BASED ON AN ANALYSIS-SYNTHESIS APPROACH USING HARMONIC NOISE MODEL

    E-Print Network [OSTI]

    So, Hing-Cheung

    SPEECH ENHANCEMENT IN CAR NOISE ENVIRONMENT BASED ON AN ANALYSIS- SYNTHESIS APPROACH USING HARMONIC using harmonic noise model (HNM) in car noise environment. The major advantages of this method are effective suppression of car noise even in very low signal-to-noise ratio environments and mitigation

  19. Activation process in excitable systems with multiple noise sources: Large number of units

    E-Print Network [OSTI]

    Igor Franovi?; Matjaž Perc; Kristina Todorovi?; Srdjan Kosti?; Nikola Buri?

    2015-07-12

    We study the activation process in large assemblies of type II excitable units whose dynamics is influenced by two independent noise terms. The mean-field approach is applied to explicitly demonstrate that the assembly of excitable units can itself exhibit macroscopic excitable behavior. In order to facilitate the comparison between the excitable dynamics of a single unit and an assembly, we introduce three distinct formulations of the assembly activation event. Each formulation treats different aspects of the relevant phenomena, including the threshold-like behavior and the role of coherence of individual spikes. Statistical properties of the assembly activation process, such as the mean time-to-first pulse and the associated coefficient of variation, are found to be qualitatively analogous for all three formulations, as well as to resemble the results for a single unit. These analogies are shown to derive from the fact that global variables undergo stochastic bifurcation from the stochastically stable fixed point to continuous oscillations. Local activation processes are analyzed in light of competition between the noise-led and the relaxation-driven dynamics. We also briefly report on a system-size anti-resonant effect displayed by the mean time-to-first pulse.

  20. System and method for characterizing voiced excitations of speech and acoustic signals, removing acoustic noise from speech, and synthesizing speech

    DOE Patents [OSTI]

    Burnett, Greg C.; Holzrichter, John F.; Ng, Lawrence C.

    2004-03-23

    The present invention is a system and method for characterizing human (or animate) speech voiced excitation functions and acoustic signals, for removing unwanted acoustic noise which often occurs when a speaker uses a microphone in common environments, and for synthesizing personalized or modified human (or other animate) speech upon command from a controller. A low power EM sensor is used to detect the motions of windpipe tissues in the glottal region of the human speech system before, during, and after voiced speech is produced by a user. From these tissue motion measurements, a voiced excitation function can be derived. Further, the excitation function provides speech production information to enhance noise removal from human speech and it enables accurate transfer functions of speech to be obtained. Previously stored excitation and transfer functions can be used for synthesizing personalized or modified human speech. Configurations of EM sensor and acoustic microphone systems are described to enhance noise cancellation and to enable multiple articulator measurements.

  1. System And Method For Characterizing Voiced Excitations Of Speech And Acoustic Signals, Removing Acoustic Noise From Speech, And Synthesizi

    DOE Patents [OSTI]

    Burnett, Greg C. (Livermore, CA); Holzrichter, John F. (Berkeley, CA); Ng, Lawrence C. (Danville, CA)

    2006-04-25

    The present invention is a system and method for characterizing human (or animate) speech voiced excitation functions and acoustic signals, for removing unwanted acoustic noise which often occurs when a speaker uses a microphone in common environments, and for synthesizing personalized or modified human (or other animate) speech upon command from a controller. A low power EM sensor is used to detect the motions of windpipe tissues in the glottal region of the human speech system before, during, and after voiced speech is produced by a user. From these tissue motion measurements, a voiced excitation function can be derived. Further, the excitation function provides speech production information to enhance noise removal from human speech and it enables accurate transfer functions of speech to be obtained. Previously stored excitation and transfer functions can be used for synthesizing personalized or modified human speech. Configurations of EM sensor and acoustic microphone systems are described to enhance noise cancellation and to enable multiple articulator measurements.

  2. System and method for characterizing voiced excitations of speech and acoustic signals, removing acoustic noise from speech, and synthesizing speech

    DOE Patents [OSTI]

    Burnett, Greg C. (Livermore, CA); Holzrichter, John F. (Berkeley, CA); Ng, Lawrence C. (Danville, CA)

    2006-08-08

    The present invention is a system and method for characterizing human (or animate) speech voiced excitation functions and acoustic signals, for removing unwanted acoustic noise which often occurs when a speaker uses a microphone in common environments, and for synthesizing personalized or modified human (or other animate) speech upon command from a controller. A low power EM sensor is used to detect the motions of windpipe tissues in the glottal region of the human speech system before, during, and after voiced speech is produced by a user. From these tissue motion measurements, a voiced excitation function can be derived. Further, the excitation function provides speech production information to enhance noise removal from human speech and it enables accurate transfer functions of speech to be obtained. Previously stored excitation and transfer functions can be used for synthesizing personalized or modified human speech. Configurations of EM sensor and acoustic microphone systems are described to enhance noise cancellation and to enable multiple articulator measurements.

  3. System and method for characterizing voiced excitations of speech and acoustic signals, removing acoustic noise from speech, and synthesizing speech

    DOE Patents [OSTI]

    Burnett, Greg C.; Holzrichter, John F.; Ng, Lawrence C.

    2006-02-14

    The present invention is a system and method for characterizing human (or animate) speech voiced excitation functions and acoustic signals, for removing unwanted acoustic noise which often occurs when a speaker uses a microphone in common environments, and for synthesizing personalized or modified human (or other animate) speech upon command from a controller. A low power EM sensor is used to detect the motions of windpipe tissues in the glottal region of the human speech system before, during, and after voiced speech is produced by a user. From these tissue motion measurements, a voiced excitation function can be derived. Further, the excitation function provides speech production information to enhance noise removal from human speech and it enables accurate transfer functions of speech to be obtained. Previously stored excitation and transfer functions can be used for synthesizing personalized or modified human speech. Configurations of EM sensor and acoustic microphone systems are described to enhance noise cancellation and to enable multiple articulator measurements.

  4. Low-noise pulsed pre-polarization magnet system for ultra-low field NMR

    SciTech Connect (OSTI)

    Sims, James R [Los Alamos National Laboratory; Schilling, Josef B [Los Alamos National Laboratory; Swenson, Charles A [Los Alamos National Laboratory; Gardner, David L [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Ammerman, Curti N [Los Alamos National Laboratory

    2009-01-01

    A liquid cooled, pulsed electromagnet of solenoid configuration suitable for duty in an ultra-low field nuclear magnetic resonance system has been designed, fabricated and successfully operated. The magnet design minimizes Johnson noise, minimizes the hydrogen signal and incorporates minimal metal and no ferromagnetic materials. In addition, an acoustically quiet cooling system permitting 50% duty cycle operation was achieved by designing for single-phase, laminar flow, forced convection cooling. Winding, conductor splicing and epoxy impregnation techniques were successfully developed to produce a coil winding body with integral cooling passageways and adequate structural integrity. Issues of material compatibility, housing, coolant flow system and heat rejection system design will be discussed. Additionally, this pulsed electromagnet design has been extended to produce a boiling liquid cooled version in a paired solenoid configuration suitable for duty in an ultra-low field nuclear magnetic resonance system. This pair of liquid nitrogen cooled coils is currently being tested and commissioned. Issues of material compatibility, thermal insulation, thermal contraction, housing and coolant flow design are discussed.

  5. Master Equation Approach for Quantum Noise in Phase-Insensitive Linear Amplifier based on Resonant Atomic Systems

    E-Print Network [OSTI]

    Minchuan Zhou; Zifan Zhou; Selim M. Shahriar

    2015-07-23

    Previously, we had proposed a white-light-cavity signal-recycling (WLC-SR) scheme incorporating a negative dispersive medium (NDM) in the SR cavity and showed an enhancement by a factor of 18 in the sensitivity-bandwidth product. For specific atomic systems, the single channel Caves model (SC-CM) that we used for the quantum noise (QN) due to amplification or absorption in the NDM may not apply. In this paper, we show that for a two-level atomic system, the SC-CM applies only when pure absorption or amplification exists. When the transmission profile of a four-level system has an absorption dip on top of a broad gain peak that results in perfect transparency at the center, the net QN is non-zero but a large, finite value. We also prove that in a Lambda-type EIT system, the QN at zero detuning is zero while the system is in the dark state. Therefore, we propose a Gain-EIT (GEIT) gain system, which has a negative dispersion and also close-to-zero noise at the center. The noise from the GEIT system at the bottom of the dip in the gain profile is not exactly zero and can be characterized by the Transparency Induced Noise Reduction Factor (TINREF), which represents the ratio of the noise in the GEIT system to that in the four-level system at the bottom of the dip in the gain profile. We show that the GEIT system with a small enough TINREF can be used as the NDM in the WLC-SR.

  6. Design and optimization of bidirectional and optical logic systems in the presence of noise

    E-Print Network [OSTI]

    Marki, Christopher Ferenc

    2007-01-01

    PBS. Bit error rate tester—BERT. Optical spectrum analyzer—tester—BERT. Optical spectrum analyzer— OSA. 2.4.2 NoiseOptical Spectrum Analyzer

  7. Combustion Noise

    E-Print Network [OSTI]

    Dowling, Ann P.; Mahmoudi, Yasser

    2014-01-01

    Combustion noise is becoming increasingly important as a major noise source in aeroengines and ground based gas turbines. This is partially because advances in design have reduced the other noise sources, and partially because next generation...

  8. Noise-induced transitions vs. noise-induced phase transitions

    E-Print Network [OSTI]

    Toral, Raúl

    Noise-induced transitions vs. noise-induced phase transitions Raul Toral IFISC (Instituto de Física the field of noise-induced phase transitions, emphasizing the main differences with the phase-induced transitions and showing that they appear in different systems. I will show that a noise-induced transition can

  9. System and method for characterizing voiced excitations of speech and acoustic signals, removing acoustic noise from speech, and synthesizing speech

    DOE Patents [OSTI]

    Burnett, Greg C. (Livermore, CA); Holzrichter, John F. (Berkeley, CA); Ng, Lawrence C. (Danville, CA)

    2002-01-01

    Low power EM waves are used to detect motions of vocal tract tissues of the human speech system before, during, and after voiced speech. A voiced excitation function is derived. The excitation function provides speech production information to enhance speech characterization and to enable noise removal from human speech.

  10. Effectiveness of two spraying systems for bollworm suppression, canopy penetration, and drift reduction in the Rolling Plains of Texas 

    E-Print Network [OSTI]

    Robinson, John Robert Calvert

    1986-01-01

    for small droplets to drift (Wodageneh and Matthews 1981). ~AA' y. ' f CDA ~tt 1 . ft f' t CDA y y developed in Great Britain in the early 1950s by E. J. Bals (Freed 1982). Various hand held models have been successfully used in tropical countries... Effectiveness of Two Spraying Systems for Bollworm Suppression, Canopy Penetration, and Drift Reduction in the Rolling Plains of Texas (May 1986) John Robert Calvert Robinson, B. S. , Texas ARM University Co-Chairmen of Advisory Committee: J. E. Slosser J. K...

  11. Method and apparatus for providing high bandwidth, low noise mechanical I/O for computer systems

    DOE Patents [OSTI]

    Rosenberg, Louis B. (Pleasanton, CA)

    1998-01-01

    A method and apparatus for providing high bandwidth and low noise mechanical input and output for computer systems. A gimbal mechanism provides two revolute degrees of freedom to an object about two axes of rotation. A linear axis member is coupled to the gimbal mechanism at the intersection of the two axes of rotation. The linear axis member is capable of being translated along a third axis to provide a third degree of freedom. The user object is coupled to the linear axis member and is thus translatable along the third axis so that the object can be moved along all three degrees of freedom. Transducers associated with the provided degrees of freedom include sensors and actuators and provide an electromechanical interface between the object and a digital processing system. Capstan drive mechanisms transmit forces between the transducers and the object. The linear axis member can also be rotated about its lengthwise axis to provide a fourth degree of freedom, and, optionally, a floating gimbal mechanism is coupled to the linear axis member to provide fifth and sixth degrees of freedom to an object. Transducer sensors are associated with the fourth, fifth, and sixth degrees of freedom. The interface is well suited for simulations of medical procedures and simulations in which an object such as a stylus or a joystick is moved and manipulated by the user.

  12. Analysis of the impact of impulse noise in digital subscriber line systems 

    E-Print Network [OSTI]

    Nedev, Nedko H

    In recent years, Digital subscriber line (DSL) technology has been gaining popularity as a high speed network access technology, capable of the delivery of multimedia services. A major impairment for DSL is impulse noise ...

  13. Method for removal of random noise in eddy-current testing system

    DOE Patents [OSTI]

    Levy, Arthur J. (Schenectady, NY)

    1995-01-01

    Eddy-current response voltages, generated during inspection of metallic structures for anomalies, are often replete with noise. Therefore, analysis of the inspection data and results is difficult or near impossible, resulting in inconsistent or unreliable evaluation of the structure. This invention processes the eddy-current response voltage, removing the effect of random noise, to allow proper identification of anomalies within and associated with the structure.

  14. Relativistic Noise

    E-Print Network [OSTI]

    Joseph Kapusta; Berndt Mueller; Misha Stephanov

    2012-01-17

    The relativistic theory of hydrodynamic fluctuations, or noise, is derived and applied to high energy heavy ion collisions. These fluctuations are inherent in any space-time varying system and are in addition to initial state fluctuations. We illustrate the effects with the boost-invariant Bjorken solution to the hydrodynamic equations. Long range correlations in rapidity are induced by propagation of sound modes. The magnitude of these correlations are directly proportional to the viscosities. These fluctuations should be enhanced near a phase transition or rapid crossover.

  15. Quantum Computers: Noise Propagation and Adversarial Noise Models

    E-Print Network [OSTI]

    Gil Kalai

    2009-04-21

    In this paper we consider adversarial noise models that will fail quantum error correction and fault-tolerant quantum computation. We describe known results regarding high-rate noise, sequential computation, and reversible noisy computation. We continue by discussing highly correlated noise and the "boundary," in terms of correlation of errors, of the "threshold theorem." Next, we draw a picture of adversarial forms of noise called (collectively) "detrimental noise." Detrimental noise is modeled after familiar properties of noise propagation. However, it can have various causes. We start by pointing out the difference between detrimental noise and standard noise models for two qubits and proceed to a discussion of highly entangled states, the rate of noise, and general noisy quantum systems.

  16. Noise tolerant spatiotemporal chaos computing

    SciTech Connect (OSTI)

    Kia, Behnam; Kia, Sarvenaz; Ditto, William L.; Lindner, John F.; Sinha, Sudeshna

    2014-12-01

    We introduce and design a noise tolerant chaos computing system based on a coupled map lattice (CML) and the noise reduction capabilities inherent in coupled dynamical systems. The resulting spatiotemporal chaos computing system is more robust to noise than a single map chaos computing system. In this CML based approach to computing, under the coupled dynamics, the local noise from different nodes of the lattice diffuses across the lattice, and it attenuates each other's effects, resulting in a system with less noise content and a more robust chaos computing architecture.

  17. Wind Turbine Generator System Acoustic Noise Test Report for the ARE 442 Wind Turbine

    SciTech Connect (OSTI)

    Huskey, A.; van Dam, J.

    2010-11-01

    This test was conducted on the ARE 442 as part of the U.S. Department of Energy's (DOE's) Independent Testing project. This project was established to help reduce the barriers of wind energy expansion by providing independent testing results for small turbines. In total, five turbines are being tested at the National Wind Technology Center (NWTC) as a part of this project. Acoustic noise testing is one of up to five tests that may be performed on the turbines, including duration, safety and function, power performance, and power quality tests. The acoustic noise test was conducted to the IEC 61400-11 Edition 2.1.

  18. A semiempirical model for two-level system noise in superconducting microresonators

    E-Print Network [OSTI]

    Martinis, John M.

    of the five resonators were measured for micro- wave readout power P w in the range -61 to -73 dBm; the -65 d, Santa Barbara, California 93106, USA 4 Jet Propulsion Laboratory, California Institute of Technology internal power, we find that the frequency noise decreases rapidly with increasing center strip width

  19. Impact of noise on a dynamical system: prediction and uncertainties from a swarm-optimized neural network

    E-Print Network [OSTI]

    López-Caraballo, C H; Salfate, I; Rojas, P; Rivera, M; Palma-Chilla, L

    2015-01-01

    In this study, an artificial neural network (ANN) based on particle swarm optimization (PSO) was developed for the time series prediction. The hybrid ANN+PSO algorithm was applied on Mackey--Glass chaotic time series in the short-term $x(t+6)$. The performance prediction was evaluated and compared with another studies available in the literature. Also, we presented properties of the dynamical system via the study of chaotic behaviour obtained from the predicted time series. Next, the hybrid ANN+PSO algorithm was complemented with a Gaussian stochastic procedure (called {\\it stochastic} hybrid ANN+PSO) in order to obtain a new estimator of the predictions, which also allowed us to compute uncertainties of predictions for noisy Mackey--Glass chaotic time series. Thus, we studied the impact of noise for several cases with a white noise level ($\\sigma_{N}$) from 0.01 to 0.1.

  20. Master Equation Approach for Quantum Noise in Phase-Insensitive Linear Amplifier based on Resonant Atomic Systems

    E-Print Network [OSTI]

    Zhou, Minchuan; Shahriar, Selim M

    2015-01-01

    Previously, we had proposed a white-light-cavity signal-recycling (WLC-SR) scheme incorporating a negative dispersive medium (NDM) in the SR cavity and showed an enhancement in the sensitivity-bandwidth product. For specific atomic systems, the single channel Caves model (SC-CM) that we used for the quantum noise (QN) due to amplification or absorption in the NDM may not apply. In this paper, we show that for a two-level atomic system, the SC-CM applies only when pure absorption or amplification exists. When the transmission profile of a four-level system has an absorption dip on top of a broad gain peak that results in perfect transparency at the center, the net QN is non-zero but a large, finite value. We also prove that in a Lambda-type EIT system, the QN at zero detuning is zero while the system is in the dark state. Therefore, we propose a Gain-EIT (GEIT) gain system, which has a negative dispersion needed for the WLC-SR scheme, but with nearly vanishing noise at the center.

  1. Analysis of Unsupervised and Noise-Robust Speaker-Adaptive HMM-Based Speech Synthesis Systems toward a Unified ASR and TTS Framework

    E-Print Network [OSTI]

    Gibson, Matt

    confusion network are used for the unsupervised systems, and noisy data recorded in cars or public spaces perspective since it may be contaminated with noise, is often recorded under a variety of conditions

  2. Activation process in excitable systems with multiple noise sources: One and two interacting units

    E-Print Network [OSTI]

    Igor Franovi?; Kristina Todorovi?; Matjaž Perc; Nebojša Vasovi?; Nikola Buri?

    2015-07-12

    We consider the coaction of two distinct noise sources on the activation process of a single or two interacting excitable units represented by the Fitzhugh-Nagumo model. The nonlocal approach involving Hamiltonian formalism is adapted to obtain the most probable activation paths around which the corresponding stochastic trajectories are clustered. The key point lies in introducing the boundary conditions relevant for a class II excitable unit, which further allow an immediate generalization to scenarios involving a couple of units. We also analyze the effects of two noise sources on the statistical features of the activation process, demonstrating how these are modified due to the linear/nonlinear form of interactions. Universal properties of activation process are qualitatively discussed in light of stochastic bifurcation, underlying transition from stochastically stable fixed point to continuous oscillations.

  3. Quantum Model Of Spin Noise

    E-Print Network [OSTI]

    R. Annabestani; D. G. Cory; J. Emerson

    2015-03-03

    Any ensemble of quantum particles exhibits statistical fluctuations known as spin noise. Here, we provide a description of spin noise in the language of open quantum systems. The description unifies the signatures of spin noise under both strong and weak measurements. Further, the model accounts for arbitrary spin dynamics from an arbitrary initial state. In all cases we can find both the spin noise and its time correlation function.

  4. An evaluation of neural networks for identification of system parameters in reactor noise signals

    SciTech Connect (OSTI)

    Miller, L.F.

    1991-12-31

    Several backpropagation neural networks for identifying fundamental mode eigenvalues were evaluated. The networks were trained and tested on analytical data and on results from other numerical methods. They were then used to predict first mode break frequencies for noise data from several sources. These predictions were, in turn, compared with analytical values and with results from alternative methods. Comparisons of results for some data sets suggest that the accuracy of predictions from neural networks are essentially equivalent to results from conventional methods while other evaluations indicate that either method may be superior. Experience gained from these numerical experiments provide insight for improving the performance of neural networks relative to other methods for identifying parameters associated with experimental data. Neural networks may also be used in support of conventional algorithms by providing starting points for nonlinear minimization algorithms.

  5. An evaluation of neural networks for identification of system parameters in reactor noise signals

    SciTech Connect (OSTI)

    Miller, L.F.

    1991-01-01

    Several backpropagation neural networks for identifying fundamental mode eigenvalues were evaluated. The networks were trained and tested on analytical data and on results from other numerical methods. They were then used to predict first mode break frequencies for noise data from several sources. These predictions were, in turn, compared with analytical values and with results from alternative methods. Comparisons of results for some data sets suggest that the accuracy of predictions from neural networks are essentially equivalent to results from conventional methods while other evaluations indicate that either method may be superior. Experience gained from these numerical experiments provide insight for improving the performance of neural networks relative to other methods for identifying parameters associated with experimental data. Neural networks may also be used in support of conventional algorithms by providing starting points for nonlinear minimization algorithms.

  6. Coherence and Decoherence in Biological Systems: Principles of Noise Assisted Transport and the Origin of Long-lived Coherences

    E-Print Network [OSTI]

    A. W. Chin; S. F. Huelga; M. B. Plenio

    2012-03-15

    The quantum dynamics of transport networks in the presence of noisy environments have recently received renewed attention with the discovery of long-lived coherences in different photosynthetic complexes. This experimental evidence has raised two fundamental questions: Firstly, what are the mechanisms supporting long-lived coherences and secondly, how can we assess the possible functional role that the interplay of noise and quantum coherence might play in the seemingly optimal operation of biological systems under natural conditions? Here we review recent results, illuminate them at the hand of two paradigmatic systems, the Fenna-Matthew-Olson (FMO) complex and the light harvesting complex LHII, and present new progress on both questions. In particular we introduce the concept of the phonon antennae and discuss the possible microscopic origin or long-lived electronic coherences.

  7. Noise-induced cooperative dynamics and its control in coupled neuron models

    E-Print Network [OSTI]

    B. Hauschildt; N. B. Janson; A. Balanov; E. Schoell

    2006-10-04

    We investigate feedback control of the cooperative dynamics of two coupled neural oscillators that is induced merely by external noise. The interacting neurons are modelled as FitzHugh-Nagumo systems with parameter values at which no autonomous oscillations occur, and each unit is forced by its own source of random fluctuations. Application of delayed feedback to only one of two subsystems is shown to be able to change coherence and timescales of noise induced oscillations either in the given subsystem, or globally. It is also able to induce or to suppress stochastic synchronization under certain conditions.

  8. Detection and location of mechanical system degradation by using detector signal noise data

    SciTech Connect (OSTI)

    Damiano, B.; Blakeman, E.D.; Phillips, L.D.

    1994-06-01

    This report describes the investigation of a diagnostic method for detecting and locating the source of structural degradation in mechanical systems. The goal of this investigation was to determine whether the diagnostic method would be practically and successfully applied to detect and locate structural changes in a mechanical system. The diagnostic method uses a mathematical model of the mechanical system to define relationships between system parameters, such as spring rates and damping rates, and measurable spectral features, such as natural frequencies and mode shapes. These model-defined relationships are incorporated into a neural network, which is used to relate measured spectral features to system parameters. The diagnosis of the system`s condition is performed by presenting the neural network with measured spectral features and comparing the system parameters estimated by the neural network to previously estimated values. Changes in the estimated system parameters indicate the location and severity of degradation in the mechanical system. The investigation involved applying the method by using computer-simulated data and data collected from a bench-top mechanical system. The effects of neural network training set size and composition on the accuracy of the model parameter estimates were investigated by using computer-simulated data. The measured data were used to demonstrate that the method can be applied to estimate the parameters of a {open_quotes}real{close_quotes} mechanical system. The results show that this diagnostic method can be applied to successfully locate and estimate the magnitude of structural changes in a mechanical system. The average error in the estimated spring rate values of the bench-top mechanical system was approximately 5 to 10%. This degree of accuracy is sufficient to permit the use of this method for detecting and locating structural degradation in mechanical systems.

  9. Colored Noise in Quantum Chaos

    E-Print Network [OSTI]

    Luca Salasnich

    2005-02-15

    We derive a set of spectral statistics whose power spectrum is characterized, in the case of chaotic quantum systems, by colored noise $1/f^{\\gamma}$, where the integer parameter $\\gamma$ critically depends on the specific energy-level statistic considered. In the case of regular quantum systems these spectral statistics show $1/f^{\\gamma+1}$ noise.

  10. Noise propagation in hybrid models of nonlinear systems: The Ginzburg–Landau equation

    SciTech Connect (OSTI)

    Taverniers, Sřren; Alexander, Francis J.; Tartakovsky, Daniel M.

    2014-04-01

    Every physical phenomenon can be described by multiple models with varying degrees of fidelity. The computational cost of higher fidelity models (e.g., molecular dynamics simulations) is invariably higher than that of their lower fidelity counterparts (e.g., a continuum model based on differential equations). While the former might not be suitable for large-scale simulations, the latter are not universally valid. Hybrid algorithms provide a compromise between the computational efficiency of a coarse-scale model and the representational accuracy of a fine-scale description. This is achieved by conducting a fine-scale computation in subdomains where it is absolutely required (e.g., due to a local breakdown of a continuum model) and coupling it with a coarse-scale computation in the rest of a computational domain. We analyze the effects of random fluctuations generated by the fine-scale component of a nonlinear hybrid on the hybrid's overall accuracy and stability. Two variants of the time-dependent Ginzburg–Landau equation (GLE) and their discrete representations provided by a nearest-neighbor Ising model serve as a computational testbed. Our analysis shows that coupling these descriptions in a one-dimensional simulation leads to erroneous results. Adding a random source term to the GLE provides accurate prediction of the mean behavior of the quantity of interest (magnetization). It also allows the two GLE variants to correctly capture the strength of the microscale fluctuations. Our work demonstrates the importance of fine-scale noise in hybrid simulations, and suggests the need for replacing an otherwise deterministic coarse-scale component of the hybrid with its stochastic counterpart.

  11. A noise-gated PLL for clock recovery in a free-space laser communication system

    E-Print Network [OSTI]

    Lund, Gavin

    2012-01-01

    In this thesis, I developed a phase-locked loop system for data clock recovery in a free-space laser communication application. The clock recovery unit is designed to operate at extremely low optical received power, tolerate ...

  12. Noise-based logic: Binary, multi-valued, or fuzzy, with optional superposition of logic states

    E-Print Network [OSTI]

    Laszlo B. Kish

    2008-12-23

    A new type of deterministic (non-probabilistic) computer logic system inspired by the stochasticity of brain signals is shown. The distinct values are represented by independent stochastic processes: independent voltage (or current) noises. The orthogonality of these processes provides a natural way to construct binary or multi-valued logic circuitry with arbitrary number N of logic values by using analog circuitry. Moreover, the logic values on a single wire can be made a (weighted) superposition of the N distinct logic values. Fuzzy logic is also naturally represented by a two-component superposition within the binary case (N=2). Error propagation and accumulation are suppressed. Other relevant advantages are reduced energy dissipation and leakage current problems, and robustness against circuit noise and background noises such as 1/f, Johnson, shot and crosstalk noise. Variability problems are also nonexistent because the logic value is an AC signal. A similar logic system can be built with orthogonal sinusoidal signals (different frequency or orthogonal phase) however that has an extra 1/N type slowdown compared to the noise-based logic system with increasing number of N furthermore it is less robust against time delay effects than the noise-based counterpart.

  13. Geotech Smart24 data acquisition system input terminated noise seismic response adjusted test : StreckeisenSTS2-low and high gain, Guralp CMG3T and Geotech GS13 seismometers.

    SciTech Connect (OSTI)

    Rembold, Randy Kai; Hart, Darren M.; Harris, James Mark

    2008-08-01

    Sandia National Laboratories has tested, evaluated and reported on the Geotech Smart24 data acquisition system with active Fortezza crypto card data signing and authentication in SAND2008-. One test, Input Terminated Noise, allows us to characterize the self-noise of the Smart24 system. By computing the power spectral density (PSD) of the input terminated noise time series data set and correcting for the instrument response of different seismometers, the resulting spectrum can be compared to the USGS new low noise model (NLNM) of Peterson (1996), and determine the ability of the matched system of seismometer and Smart24 to be quiet enough for any general deployment location. Four seismometer models were evaluated: the Streckeisen STS2-Low and High Gain, Guralp CMG3T and Geotech GS13 models. Each has a unique pass-band as defined by the frequency band of the instrument corrected noise spectrum that falls below the new low-noise model.

  14. Noise Brush: Interactive High Quality Image-Noise Separation Chi-Keung Tang

    E-Print Network [OSTI]

    Wang, Jue

    Noise Brush: Interactive High Quality Image-Noise Separation Jia Chen Chi-Keung Tang The Hong) and a noise layer (bottom) (this example is produced by Noiseware [Imagenomic Inc. 2008]), our system provides the user with a set of easy interactive control to achieve high quality image-noise separation shown in (c

  15. Noise-Induced Transitions in Optomechanical Synchronization

    E-Print Network [OSTI]

    Talitha Weiss; Andreas Kronwald; Florian Marquardt

    2015-07-22

    We study how quantum and thermal noise affects synchronization of two optomechanical limit-cycle oscillators. Classically, in the absence of noise, optomechanical systems tend to synchronize either in-phase or anti-phase. Taking into account the fundamental quantum noise, we find a regime where fluctuations drive transitions between these classical synchronization states. We investigate how this "mixed" synchronization regime emerges from the noiseless system by studying the classical-to-quantum crossover and we show how the time scales of the transitions vary with the effective noise strength. In addition, we compare the effects of thermal noise to the effects of quantum noise.

  16. An ultra low-noise AC beam transformer and digital signal processing system for CERN's ELENA ring

    E-Print Network [OSTI]

    Angoletta, M E; Caspers, F; Federmann, S; Molendijk, J; Pedersen, F; Sanchez-Quesada, J

    2013-01-01

    CERN’s Extra Low ENergy Antiproton (ELENA) ring is a new synchrotron that will be commissioned in 2016 to further decelerate the antiprotons coming from CERN’s Antiproton Decelerator (AD). Essential longitudinal diagnostics required for commissioning and operation include the intensity measurement for bunched and debunched beams and the measurement of p/p for debunched beams to assess the electron cooling performance. The beam phase information is also needed by the Low-Level RF (LLRF) system. The baseline system for providing the required beam parameters and signals is based upon two ultra-low-noise AC beam transformers and associated digital signal processing. The AC beam transformers cover different frequency regions and are an adaptation to the ELENA layout of those used in the AD. Two AC beam transformers will also be installed in the extraction lines to provide beam intensity measurements. The digital signal processing will be carried out with the leadingedge hardware family used for ELENA’s L...

  17. Quantum noise in photothermal cooling

    SciTech Connect (OSTI)

    De Liberato, Simone [Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Lambert, Neill [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Nori, Franco [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2011-03-15

    We study the problem of cooling a mechanical oscillator using the photothermal (bolometric) force. Contrary to previous attempts to model this system, we take into account the noise effects due to the granular nature of photon absorption. We achieve this by developing a Langevin formalism for the motion of the cantilever, valid in the bad-cavity limit, which includes both photon absorption shot noise and the noise due to radiation pressure. This allows us to tackle the cooling problem down to the noise-dominated regime and to find reasonable estimates for the lowest achievable phonon occupation in the cantilever.

  18. Noise Secured Internet

    E-Print Network [OSTI]

    Geraldo A. Barbosa

    2006-02-28

    This work shows how a secure Internet can be implemented through a fast key distribution system that uses physical noise to protect the transmitted information. Starting from a shared random sequence $K_0$ between two (or more) users, longsequences $R$ of random bits can be shared. The signals sent over the Internet are deterministic but have a built-in Nature-made uncertainty that protects the shared sequences. After privacy amplification the shared $R$ random bits --encrypted by noise-- are subsequently utilized in one-time-pad data ciphering.

  19. Thermal noise driven computing

    E-Print Network [OSTI]

    Laszlo B. Kish

    2006-10-28

    The possibility of a new type of computing, where thermal noise is the information carrier and the clock in a computer, is studied. The information channel capacity and the lower limit of energy requirement/dissipation are studied in a simple digital system with zero threshold voltage, for the case of error probability close to 0.5, when the thermal noise is equal to or greater than the digital signal. In a simple hypothetical realization of a thermal noise driven gate, the lower limit of energy needed to generate the digital signal is 1.1*kT/bit. The arrangement has potentially improved energy efficiency and it is free of leakage current, crosstalk and ground plane electromagnetic interference problems. Disadvantage is the large number of redundancy elements needed for low-error operation.

  20. Analysis of Microphonic Noise Genesis and Mitigation in a Boron Carbide Detector System 

    E-Print Network [OSTI]

    Gordon, William

    2015-05-28

    is 170 keV. When these calculations are carried out for both the 4He and 7Li nuclides the minimum path length for detection are found to be 6.7 mm and 4.1 mm respectively. The internal diameter of the copper straw is 4.60 mm. The anode wire has a... power of 4He and 7Li fragments from the short lived 11B nuclide. For real world systems however, some of the energy from the 4He peak at 1.47 MeV and 7Li peak at 0.840 MeV would be lost transporting through the 1.4 µm boron carbide layer. The stopping...

  1. A moment-equation-copula-closure method for nonlinear vibrational systems subjected to correlated noise

    E-Print Network [OSTI]

    Han Kyul Joo; Themistoklis P. Sapsis

    2015-10-07

    We develop a moment equation closure minimization method for the inexpensive approximation of the steady state statistical structure of nonlinear systems whose potential functions have bimodal shapes and which are subjected to correlated excitations. Our approach relies on the derivation of moment equations that describe the dynamics governing the two-time statistics. These are combined with a non-Gaussian pdf representation for the joint response-excitation statistics that has i) single time statistical structure consistent with the analytical solutions of the Fokker-Planck equation, and ii) two-time statistical structure with Gaussian characteristics. Through the adopted pdf representation, we derive a closure scheme which we formulate in terms of a consistency condition involving the second order statistics of the response, the closure constraint. A similar condition, the dynamics constraint, is also derived directly through the moment equations. These two constraints are formulated as a low-dimensional minimization problem with respect to unknown parameters of the representation, the minimization of which imposes an interplay between the dynamics and the adopted closure. The new method allows for the semi-analytical representation of the two-time, non-Gaussian structure of the solution as well as the joint statistical structure of the response-excitation over different time instants. We demonstrate its effectiveness through the application on bistable nonlinear single-degree-of-freedom energy harvesters with mechanical and electromagnetic damping, and we show that the results compare favorably with direct Monte-Carlo Simulations.

  2. Effects of noise exposure on click detection and the temporal resolution ability of the goldfish auditory system

    E-Print Network [OSTI]

    Ladich, Friedrich

    (hydroelectric or offshore wind power plants), noise is an ever-increasing environmental factor in the aquatic environment (Myrberg, 1990). A long-term study (Andrew et al., 2002) has demonstrated that the overall ocean

  3. Chaos and Noise

    E-Print Network [OSTI]

    Temple He; Salman Habib

    2012-11-20

    Simple dynamical systems -- with a small number of degrees of freedom -- can behave in a complex manner due to the presence of chaos. Such systems are most often (idealized) limiting cases of more realistic situations. Isolating a small number of dynamical degrees of freedom in a realistically coupled system generically yields reduced equations with terms that can have a stochastic interpretation. In situations where both noise and chaos can potentially exist, it is not immediately obvious how Lyapunov exponents, key to characterizing chaos, should be properly defined. In this paper, we show how to do this in a class of well-defined noise-driven dynamical systems, derived from an underlying Hamiltonian model.

  4. Shot noise in tunneling through a quantum dot array G. Kiesslich*; 1

    E-Print Network [OSTI]

    Hohls, Frank

    Shot noise in tunneling through a quantum dot array G. Kiesslich*; 1 , A. Wacker1 , E. Schćll1 , A 2003 PACS 72.70.+m, 73.40.Gk, 73.63.Kv The shot noise suppression in a sample containing a layer be qualitatively reproduced by an analy- tical expression. 1 Introduction Shot noise measurements provide

  5. Nonlinear noise cancellation 

    E-Print Network [OSTI]

    Strauch, Paul E

    Noise or interference is often assumed to be a random process. Conventional linear filtering, control or prediction techniques are used to cancel or reduce the noise. However, some noise processes have been shown to be ...

  6. Effective DQE (eDQE) for monoscopic and stereoscopic chest radiography imaging systems with the incorporation of anatomical noise

    SciTech Connect (OSTI)

    Boyce, Sarah J. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27695 (United States)] [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 and Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27695 (United States); Choudhury, Kingshuk Roy [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States)] [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States) [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Biomedical Engineering, Duke University, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories, Department of Physics, Duke University, Durham, North Carolina 27705 (United States)

    2013-09-15

    Purpose: Stereoscopic chest biplane correlation imaging (stereo/BCI) has been proposed as an alternative modality to single view chest x-ray (CXR). The metrics effective modulation transfer function (eMTF), effective normalized noise power spectrum (eNNPS), and effective detective quantum efficiency (eDQE) have been proposed as clinically relevant metrics for assessing clinical system performance taking into consideration the magnification and scatter effects. This study compared the metrics eMTF, eNNPS, eDQE, and detectability index for stereo/BCI and single view CXR under isodose conditions at two magnifications for two anthropomorphic phantoms of differing sizes.Methods: Measurements for the eMTF were taken for two phantom sizes with an opaque edge test device using established techniques. The eNNPS was measured at two isodose conditions for two phantoms using established techniques. The scatter was measured for two phantoms using an established beam stop method. All measurements were also taken at two different magnifications with two phantoms. A geometrical phantom was used for comparison with prior results for CXR although the results for an anatomy free phantom are not expected to vary for BCI.Results: Stereo/BCI resulted in improved metrics compared to single view CXR. Results indicated that magnification can potentially improve the detection performance primarily due to the air gap which reduced scatter by ?20%. For both phantoms, at isodose, eDQE(0) for stereo/BCI was ?100 times higher than that for CXR. Magnification at isodose improved eDQE(0) by ?10 times for stereo/BCI. Increasing the dose did not improve eDQE. The detectability index for stereo/BCI was ?100 times better than single view CXR for all conditions. The detectability index was also not improved with increased dose.Conclusions: The findings indicate that stereo/BCI with magnification may improve detectability of subtle lung nodules compared to single view CXR. Results were improved with magnification for the smaller phantom but not for the larger phantom. The effective DQE and the detectability index did not improve with increasing dose.

  7. Benchmark enclosure fire suppression experiments - phase 1 test report.

    SciTech Connect (OSTI)

    Figueroa, Victor G.; Nichols, Robert Thomas; Blanchat, Thomas K.

    2007-06-01

    A series of fire benchmark water suppression tests were performed that may provide guidance for dispersal systems for the protection of high value assets. The test results provide boundary and temporal data necessary for water spray suppression model development and validation. A review of fire suppression in presented for both gaseous suppression and water mist fire suppression. The experimental setup and procedure for gathering water suppression performance data are shown. Characteristics of the nozzles used in the testing are presented. Results of the experiments are discussed.

  8. Chapter 9 Audible Noise

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by typical sources such as traffic, neighboring businesses or industries, and weather (wind or rain). The ambient noise level is typically a mix of noise from natural and...

  9. BIOGEOCHEMISTRY LETTERS Chronic nitrogen additions suppress decomposition

    E-Print Network [OSTI]

    Templer, Pamela

    BIOGEOCHEMISTRY LETTERS Chronic nitrogen additions suppress decomposition and sequester soil carbon dioxide emis- sions, offsetting a substantial portion of greenhouse gas forcing of the climate system. Although a number of factors are responsible for this terrestrial carbon sink, atmospheric nitrogen

  10. Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

    DOE Patents [OSTI]

    West, Phillip B.; Haefner, Daryl

    2004-08-17

    Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

  11. Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

    DOE Patents [OSTI]

    West, Phillip B.; Haefner, Daryl

    2005-12-13

    Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

  12. Suppression of pool fires with HRC-125 in a simulated engine nacelle.

    SciTech Connect (OSTI)

    Keyser, David R. (INS, Inc., Lexington Park, MD); Hewson, John C.

    2007-06-01

    CFD simulations are conducted to predict the distribution of fire suppressant in an engine nacelle and to predict the suppression of pool fires by the application of this suppressant. In the baseline configuration, which is based on an installed system, suppressant is injected through four nozzles at a rate fast enough to suppress all simulated pool fires. Variations that reduce the mass of the suppression system (reducing the impact of the suppression system on meeting mission needs) are considered, including a reduction in the rate of suppressant injection, a reduction in the mass of suppressant and a reduction in the number of nozzles. In general, these variations should work to reduce the effectiveness of the suppression system, but the CFD results point out certain changes that have negligible impact, at least for the range of phenomena considered here. The results are compared with measurements where available. Comparisons with suppressant measurements are reasonable. A series of twenty-three fire suppression tests were conducted to check the predictions. The pre-test predictions were generally successful in identifying the range of successful suppression tests. In two separate cases, each where one nozzle of the suppression system was capped, the simulation results did indicate a failure to suppress for a condition where the tests indicated successful suppression. When the test-suppressant discharge rate was reduced by roughly 25%, the tests were in agreement with the predictions. That is, the simulations predict a failure to suppress slightly before observed in these cases.

  13. Cancer: A suppression switch

    E-Print Network [OSTI]

    Starobinets, H; Debnath, J

    2013-01-01

    Cancer A suppression switch The status of the protein p53it seems that p53 acts as a switch in pancreatic cancer thatthe ability of p53 to switch the clinical outcome of

  14. Characterization and Suppression of the Electromagnetic Interference Induced Phase Shift in the JLab FEL Photo - Injector Advanced Drive Laser System

    SciTech Connect (OSTI)

    F. G. Wilson, D. Sexton, S. Zhang

    2011-09-01

    The drive laser for the photo-cathode gun used in the JLab Free Electron Laser (FEL) facility had been experiencing various phase shifts on the order of tens of degrees (>20{sup o} at 1497 MHz or >40ps) when changing the Advanced Drive Laser (ADL) [2][3][4] micro-pulse frequencies. These phase shifts introduced multiple complications when trying to setup the accelerator for operation, ultimately inhibiting the robustness and overall performance of the FEL. Through rigorous phase measurements and systematic characterizations, we determined that the phase shifts could be attributed to electromagnetic interference (EMI) coupling into the ADL phase control loop, and subsequently resolved the issue of phase shift to within tenths of a degree (<0.5{sup o} at 1497 MHz or <1ps). The diagnostic method developed and the knowledge gained through the entire process will prove to be invaluable for future designs of similar systems.

  15. Global Noise Studies for CMS Tracker Upgrade

    SciTech Connect (OSTI)

    Arteche, F.; Esteban, C.; Echevarria, I.; Iglesias, M.; Rivetta, C.; Vila, I.; /Cantabria Inst. of Phys.

    2012-06-11

    The characterization of the noise emissions of DC-DC converters at system level is critical to optimize the design of the detector and define rules for the integration strategy. This paper presents the impedance effects on the noise emissions of DC-DC converters at system level. Conducted and radiated noise emissions at the input and at the output from DC-DC converters have been simulated for different types of power network and FEE impedances. System aspects as granularity, stray capacitances of the system and different working conditions of the DC-DC converters are presented too. This study has been carried out using simulation models of noise emissions of DC-DC converters in the real scenario. The results of these studies show important recommendations and criteria to be applied to integrate the DC-DC converters and decrease the system noise level.

  16. System and method of reducing motion-induced noise in the optical detection of an ultrasound signal in a moving body of material

    DOE Patents [OSTI]

    Habeger, Jr., Charles C. (Smyrna, GA); LaFond, Emmanuel F. (Atlanta, GA); Brodeur, Pierre (Smyrna, GA); Gerhardstein, Joseph P. (Decatur, GA)

    2002-01-01

    The present invention provides a system and method to reduce motion-induced noise in the detection of ultrasonic signals in a moving sheet or body of material. An ultrasonic signal is generated in a sheet of material and a detection laser beam is moved along the surface of the material. By moving the detection laser in the same direction as the direction of movement of the sheet of material the amount of noise induced in the detection of the ultrasonic signal is reduced. The scanner is moved at approximately the same speed as the moving material. The system and method may be used for many applications, such in a paper making process or steel making process. The detection laser may be directed by a scanner. The movement of the scanner is synchronized with the anticipated arrival of the ultrasonic signal under the scanner. A photodetector may be used to determine when a ultrasonic pulse has been directed to the moving sheet of material so that the scanner may be synchronized the anticipated arrival of the ultrasonic signal.

  17. Water Mist Suppression in Conjunction with Displacement

    E-Print Network [OSTI]

    Hickman, Mark

    Water Mist Suppression in Conjunction with Displacement Ventilation By Benjamin Piers Hume-2758 #12;#12;Displacement Water Mist System Masters of Fire Engineering Thesis 2003 i A man of genius makes Water Mist System Masters of Fire Engineering Thesis 2003 ii #12;Displacement Water Mist System Masters

  18. Noise reduction efforts for the ALS infrared beamlines Tom Scarvie *, Nord Andresen, Ken Baptiste, John Byrd, Mike Chin,

    E-Print Network [OSTI]

    Noise reduction efforts for the ALS infrared beamlines Tom Scarvie *, Nord Andresen, Ken Baptiste data collected at synchrotron based sources is strongly dependent on signal-to-noise. We have successfully identified and suppressed several noise sources affecting beamlines 1.4.2, 1.4.3, and 1

  19. Empirical Characterization of Camera Noise

    E-Print Network [OSTI]

    Manduchi, Roberto; Baumgartner, Jeremy; Hinsche, Markus

    2013-01-01

    camera calibration and noise estimation. IEEE Transactionsestimation and removal of noise from a single image. IEEE279, 1998. 7. H. Tian. Noise Analysis in CMOS Image Sensors.

  20. Empirical Characterization of Camera Noise

    E-Print Network [OSTI]

    Manduchi, Roberto; Baumgartner, Jeremy; Hinsche, Markus

    2013-01-01

    Empirical Characterization of Camera Noise JeremyAbstract. Noise characterization is important for severalprocedure produces a characterization of camera noise as a

  1. Minimal noise subsystems

    E-Print Network [OSTI]

    Xiaoting Wang; Mark Byrd; Kurt Jacobs

    2013-05-09

    The existence of a decoherence-free subspace/subsystem (DFS) requires that the noise possesses a symmetry. In this work we consider noise models in which perturbations break this symmetry, so that the DFS for the unperturbed model experiences noise. We ask whether in this case there exist subspaces/subsystems that have less noise than the original DFS. We develop a numerical method to search for such minimal noise subsystems and apply it to a number of examples. For the examples we examine, we find that if the perturbation is local noise then there is no better subspace/subsystem than the original DFS. We also show that if the noise model remains collective, but is perturbed in a way that breaks the symmetry, then the minimal noise subsystem is distinct from the original DFS, and improves upon it.

  2. Nuclear spin noise in NMR revisited

    E-Print Network [OSTI]

    Ferrand, Guillaume; Luong, Michel; Desvaux, Hervé

    2015-01-01

    The theoretical shapes of nuclear spin-noise spectra in NMR are derived by considering a receiver circuit with finite, preamplifier input impedance and a transmission line between the preamplifier and the probe. Using this model, it becomes possible to reproduce all observed experimental features: variation of the NMR resonance linewidth as a function of the transmission line phase, nuclear spin-noise signals appearing as a "bump" or as a "dip" superimposed on the average electronic noise level even for a spin system and probe at the same temperature, pure in-phase Lorentzian spin-noise signals exhibiting non-vanishing frequency shifts. Extensive comparison to experimental measurements validate the model predictions, and define the conditions for obtaining pure in-phase Lorentzian-shape nuclear spin noise with a vanishing frequency shift, in other words, the conditions for simultaneously obtaining the Spin-Noise and Frequency-Shift Tuning Optima.

  3. Shot-noise at a Fermi-edge singularity: Non-Markovian dynamics

    SciTech Connect (OSTI)

    Ubbelohde, N.; Maire, N.; Haug, R. J.; Roszak, K.; Hohls, F.; Novotný, T.

    2013-12-04

    For an InAs quantum dot we study the current shot noise at a Fermi-edge singularity in low temperature cross-correlation measurements. In the regime of the interaction effect the strong suppression of noise observed at zero magnetic field and the sequence of enhancement and suppression in magnetic field go beyond a Markovian master equation model. Qualitative and quantitative agreement can however be achieved by a generalized master equation model taking non-Markovian dynamics into account.

  4. Learning Noise Michael Schmidt

    E-Print Network [OSTI]

    Fernandez, Thomas

    Learning Noise Michael Schmidt Computational Synthesis Laboratory Cornell University Ithaca NY to learning stochastic models with unsymmetrical noise distributions. Most learning algorithms try to learn from noisy data by modeling the maximum likelihood output or least squared error, assuming that noise

  5. Symplectic Noise & The Classical Analog of the Lindblad Generator

    E-Print Network [OSTI]

    John Gough

    2015-08-26

    We introduce the concepts of Poisson brackets for classical noise, and of canonically conjugate Wiener processes (symplectic noise). Phase space diffusions driven by these processes are considered and the general form of a stochastic process preserving the full (system and noise) Poisson structure is obtained. We show that, once the classical stochastic model is required to preserve the joint system and noise Poisson bracket, it has much in common with quantum markovian models.

  6. Shot noise and thermal noise have long been

    E-Print Network [OSTI]

    Sarpeshkar, Rahul

    in Shot noise and thermal noise have long been considered the results of two distinct mechanisms, but they aren't White Noise MOS Ti.ansistors and Resistors e live in a very energy-conscious era to the effects of noise. Hence, a good understanding of noise is timely. Most people find the subject of noise

  7. Equilibrium-reduced density matrix formulation: Influence of noise, disorder, and temperature on localization in excitonic systems

    E-Print Network [OSTI]

    Moix, Jeremy M.

    An exact method to compute the entire equilibrium-reduced density matrix for systems characterized by a system-bath Hamiltonian is presented. The approach is based upon a stochastic unraveling of the influence functional ...

  8. Optomechanical entanglement in the presence of laser phase noise

    SciTech Connect (OSTI)

    Ghobadi, R. [Institute for Quantum Information Science and Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, T2N 1N4 (Canada); Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Bahrampour, A. R. [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Simon, C. [Institute for Quantum Information Science and Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, T2N 1N4 (Canada)

    2011-12-15

    We study the simplest optomechanical system in the presence of laser phase noise (LPN) using the covariance matrix formalism. We show that for any LPN model with a finite correlation time, the destructive effect of the phase noise is especially strong in the bistable regime. This explains why ground-state cooling is still possible in the presence of phase noise, as it happens far away from the bistable regime. We also show that the optomechanical entanglement is strongly affected by phase noise.

  9. Vibration suppression, stabilization, motion planning and tracking for flexible beams

    E-Print Network [OSTI]

    Siranosian, Antranik Antonio

    2009-01-01

    22] J. P. Den Hartog, Mechanical Vibrations, 3rd ed. McGraw-absorber reduces vibrations of a mechanical system it isimprove vibration suppression on a mechanical system forced

  10. The effects of intrinsic noise on the behaviour of bistable cell regulatory systems under quasi-steady state conditions

    E-Print Network [OSTI]

    Roberto de la Cruz; Pilar Guerrero; Fabian Spill; Tomás Alarcón

    2015-08-12

    We analyse the effect of intrinsic fluctuations on the properties of bistable stochastic systems with time scale separation operating under1 quasi-steady state conditions. We first formulate a stochastic generalisation of the quasi-steady state approximation based on the semi-classical approximation of the partial differential equation for the generating function associated with the Chemical Master Equation. Such approximation proceeds by optimising an action functional whose associated set of Euler-Lagrange (Hamilton) equations provide the most likely fluctuation path. We show that, under appropriate conditions granting time scale separation, the Hamiltonian can be re-scaled so that the set of Hamilton equations splits up into slow and fast variables, whereby the quasi-steady state approximation can be applied. We analyse two particular examples of systems whose mean-field limit has been shown to exhibit bi-stability: an enzyme-catalysed system of two mutually-inhibitory proteins and a gene regulatory circuit with self-activation. Our theory establishes that the number of molecules of the conserved species are order parameters whose variation regulates bistable behaviour in the associated systems beyond the predictions of the mean-field theory. This prediction is fully confirmed by direct numerical simulations using the stochastic simulation algorithm. This result allows us to propose strategies whereby, by varying the number of molecules of the three conserved chemical species, cell properties associated to bistable behaviour (phenotype, cell-cycle status, etc.) can be controlled.

  11. Quantum Computers: Noise Propagation and Adversarial Noise Models

    E-Print Network [OSTI]

    Kalai, Gil

    Quantum Computers: Noise Propagation and Adversarial Noise Models Gil Kalai Hebrew University of Jerusalem and Yale University April 21, 2009 Abstract In this paper we consider adversarial noise models." Detrimental noise is modeled after familiar properties of noise propagation. However, it can have various

  12. A continuous-time multi-stage noise-shaping delta-sigma modulator for next generation wireless applications

    E-Print Network [OSTI]

    Yoon, Do Yeon

    2015-01-01

    A continuous-time (CT) delta-sigma ([delta][sigma]) modulator for modern wireless communication applications is investigated in this thesis. Quantization noise is suppressed aggressively by increasing the effective order ...

  13. Longitudinal beam dynamics with rf noise

    SciTech Connect (OSTI)

    Shih, H.J.; Ellison, J.A.; Cogburn, R.; Newberger, B.S.

    1993-06-01

    The Dome-Krinsky-Wang (DKW) diffusion-inaction theory for rf-noise-induced emittance dilution is reviewed and related to recent work on the approximation of stochastic processes by Markov processes. An accurate and efficient numerical procedure is developed to integrate the diffusion equation of the DKW theory. Tracking simulations are undertaken to check the validity of the theory in the parameter range of the Superconducting Super Collider (SSC) and to provide additional information. The study of effects of rf noise is applied to two problems of interest at the SSC: (1) determination of noise tolerance levels in the rf system, and (2) feasibility of beam extraction using crystal channeling.

  14. A moment-equation-closure minimization method for bi-stable nonlinear vibrational systems subjected to correlated noise

    E-Print Network [OSTI]

    Han Kyul Joo; Themistoklis P. Sapsis

    2015-02-04

    We develop a moment equation closure minimization method for the inexpensive approximation of the steady state statistical structure of nonlinear systems whose potential functions have bimodal shapes and which are subjected to correlated excitations. Our approach relies on the derivation of moment equations that describe the dynamics governing the two-time statistics. These are combined with a non-Gaussian pdf representation for the joint response-excitation statistics that has i) single time statistical structure consistent with the analytical solutions of the Fokker-Planck equation, and ii) two-time statistical structure with Gaussian characteristics. Through the adopted pdf representation, we derive a closure scheme which we formulate in terms of a consistency condition involving the second order statistics of the response, the closure constraint. A similar condition, the dynamics constraint, is also derived directly through the moment equations. These two constraints are formulated as a low-dimensional minimization problem with respect to unknown parameters of the representation, the minimization of which imposes an interplay between the dynamics and the adopted closure. The new method allows for the semi-analytical representation of the two-time, non-Gaussian structure of the solution as well as the joint statistical structure of the response-excitation over different time instants. We demonstrate its effectiveness through the application on bistable nonlinear single-degree-of-freedom energy harvesters with mechanical and electromagnetic damping, and we show that the results compare favorably with direct Monte-Carlo Simulations.

  15. Influence of monolayer contamination on electric-field-noise heating in ion traps

    E-Print Network [OSTI]

    A. Safavi-Naini; E. Kim; P. F. Weck; P. Rabl; H. R. Sadeghpour

    2012-09-28

    Electric field noise is a hinderance to the assembly of large scale quantum computers based on entangled trapped ions. Apart from ubiquitous technical noise sources, experimental studies of trapped ion heating have revealed additional limiting contributions to this noise, originating from atomic processes on the electrode surfaces. In a recent work [A. Safavi-Naini et al., Phys. Rev. A 84, 023412 (2011)] we described a microscopic model for this excess electric field noise, which points a way towards a more systematic understanding of surface adsorbates as progenitors of electric field jitter noise. Here, we address the impact of surface monolayer contamination on adsorbate induced noise processes. By using exact numerical calculations for H and N atomic monolayers on an Au(111) surface representing opposite extremes of physisorption and chemisorption, we show that an additional monolayer can significantly affect the noise power spectrum and either enhance or suppress the resulting heating rates.

  16. Noise sources and dissipation mechanisms of a 120 # SQUID amplifier Paolo Falferi, a) Michele Bonaldi, and Antonella Cavalleri

    E-Print Network [OSTI]

    Noise sources and dissipation mechanisms of a 120 # SQUID amplifier Paolo Falferi, a) Michele of the noise generated by this system, the back action noise of the SQUID amplifier is estimated. The minimum noise temperature, calculated from back action and additive noise measurements, is 63 #K at 1.33 K

  17. Graphene-based terahertz photodetector by noise thermometry technique

    SciTech Connect (OSTI)

    Wang, Ming-Jye; Wang, Ji-Wun; Wang, Chun-Lun; Chiang, Yen-Yu; Chang, Hsian-Hong

    2014-01-20

    We report the characteristics of graphene-based terahertz (THz) photodetector based on noise thermometry technique by measuring its noise power at frequency from 4 to 6 GHz. Hot electron system in graphene microbridge is generated after THz photon pumping and creates extra noise power. The equivalent noise temperature and electron temperature increase rapidly in low THz pumping regime and saturate gradually in high THz power regime which is attributed to a faster energy relaxation process involved by stronger electron-phonon interaction. Based on this detector, a conversion efficiency around 0.15 from THz power to noise power in 4–6?GHz span has been achieved.

  18. Robust Shot Noise Measurement for Continuous Variable Quantum Key Distribution

    E-Print Network [OSTI]

    Sébastien Kunz-Jacques; Paul Jouguet

    2015-01-17

    We study a practical method to measure the shot noise in real time in Continuous Variable Quantum Key Distribution (CVQKD) systems. The amount of secret key that can be extracted from the raw statistics depends strongly on this quantity since it affects in particular the computation of the excess noise (i.e. noise in excess of the shot noise) added by an eavesdropper on the quantum channel. Some powerful quantum hacking attacks relying on faking the estimated value of the shot noise to hide an intercept and resend strategy were proposed. Here, we provide experimental evidence that our method can defeat the saturation attack and the wavelength attack.

  19. Blown flap noise

    E-Print Network [OSTI]

    Haas Martin

    1972-01-01

    This report is concerned with the noise generated by blown flaps of the type currently being developed for the short take off and landing aircraft. The majority of the report is an experimental study of the sound-radiation ...

  20. NOISE DETECTION AND CLASSIFICATION IN SPEECH SIGNALS WITH BOOSTING Nobuyuki Miyake, Tetsuya Takiguchi and Yasuo Ariki

    E-Print Network [OSTI]

    Takiguchi, Tetsuya

    NOISE DETECTION AND CLASSIFICATION IN SPEECH SIGNALS WITH BOOSTING Nobuyuki Miyake, Tetsuya to detect and classify sud- den noises in speech signals. There are many sudden and short-period noises in natural environments, such as inside a car. If a speech recognition system can detect sudden noises

  1. Measurement Noise versus Process Noise in Ionosphere Estimation for WAAS

    E-Print Network [OSTI]

    Stanford University

    Measurement Noise versus Process Noise in Ionosphere Estimation for WAAS Juan Blanch, Todd Walter of several parameters: the geometry of the measurements, the measurement noise, and the state of the ionosphere, which yields the process noise. It is very important to distinguish carefully between measurement

  2. USING THE LINEAR NOISE APPROXIMATION TO CHARACTERIZE MOLECULAR NOISE IN

    E-Print Network [OSTI]

    Ingalls, Brian

    USING THE LINEAR NOISE APPROXIMATION TO CHARACTERIZE MOLECULAR NOISE IN REACTION PATHWAYS Matthew Canada N2L 3G1 Abstract The Linear Noise Approximation offers an elegant analytic method to probe the effects of molecular noise on small-scale chemical reaction pathways by expanding the full chemical Master

  3. Substrate Noise Reduction Based On Noise Aware Cell Design

    E-Print Network [OSTI]

    Friedman, Eby G.

    Substrate Noise Reduction Based On Noise Aware Cell Design Emre Salman, Eby G. Friedman Department dedicated sub- strate contacts in those cells behaving as aggressive digital noise generators. These contacts are connected to a dedicated ground network. The proposed approach reduces two primary noise

  4. Entangled quantum probes for dynamical environmental noise

    E-Print Network [OSTI]

    Matteo A. C. Rossi; Matteo G. A. Paris

    2015-03-11

    We address the use of entangled qubits as quantum probes to characterize the dynamical noise induced by complex environments. In particular, we show that entangled probes improve estimation of the correlation time for a broad class of environmental noises compared to any sequential strategy involving single qubit preparation. The effect is present when the noise is faster than a threshold value, a regime which may always be achieved by tuning the coupling between the quantum probe and the environment inducing the noise. Our scheme exploits time-dependent sensitivity of quantum systems to decoherence and does not require dynamical control on the probes. We derive the optimal interaction time and the optimal probe preparation, showing that it corresponds to multiqubit GHZ states when entanglement is useful. We also show robustness of the scheme against depolarization or dephasing of the probe, and discuss simple measurements approaching optimal precision.

  5. Mode-hopping mechanism generating colored noise in a magnetic tunnel junction based spin torque oscillator

    SciTech Connect (OSTI)

    Sharma, Raghav; Dürrenfeld, P.; Iacocca, E.; Heinonen, O. G.; Ĺkerman, J.; Muduli, P. K.

    2014-09-29

    The frequency noise spectrum of a magnetic tunnel junction based spin torque oscillator is examined where multiple modes and mode-hopping events are observed. The frequency noise spectrum is found to consist of both white noise and 1/f frequency noise. We find a systematic and similar dependence of both white noise and 1/f frequency noise on bias current and the relative angle between the reference and free layers, which changes the effective damping and hence the mode-hopping behavior in this system. The frequency at which the 1/f frequency noise changes to white noise increases as the free layer is aligned away from the anti-parallel orientation w.r.t the reference layer. These results indicate that the origin of 1/f frequency noise is related to mode-hopping, which produces both white noise as well as 1/f frequency noise similar to the case of ring lasers.

  6. Nonlinear Biochemical Signal Processing via Noise Propagation

    E-Print Network [OSTI]

    Kyung Hyuk Kim; Hong Qian; Herbert M. Sauro

    2013-09-10

    Single-cell studies often show significant phenotypic variability due to the stochastic nature of intra-cellular biochemical reactions. When the numbers of molecules, e.g., transcription factors and regulatory enzymes, are in low abundance, fluctuations in biochemical activities become significant and such "noise" can propagate through regulatory cascades in terms of biochemical reaction networks. Here we develop an intuitive, yet fully quantitative method for analyzing how noise affects cellular phenotypes based on identifying a system's nonlinearities and noise propagations. We observe that such noise can simultaneously enhance sensitivities in one behavioral region while reducing sensitivities in another. Employing this novel phenomenon we designed three biochemical signal processing modules: (a) A gene regulatory network that acts as a concentration detector with both enhanced amplitude and sensitivity. (b) A non-cooperative positive feedback system, with a graded dose-response in the deterministic case, that serves as a bistable switch due to noise-induced bimodality. (c) A noise-induced linear amplifier for gene regulation that requires no feedback. The methods developed in the present work allow one to understand and engineer nonlinear biochemical signal processors based on fluctuation-induced phenotypes.

  7. Characterization of control noise effects in optimal quantum unitary dynamics

    E-Print Network [OSTI]

    David Hocker; Constantin Brif; Matthew D. Grace; Ashley Donovan; Tak-San Ho; Katharine Moore Tibbetts; Rebing Wu; Herschel Rabitz

    2014-11-13

    This work develops measures for quantifying the effects of field noise upon targeted unitary transformations. Robustness to noise is assessed in the framework of the quantum control landscape, which is the mapping from the control to the unitary transformation performance measure (quantum gate fidelity). Within that framework, a new geometric interpretation of stochastic noise effects naturally arises, where more robust optimal controls are associated with regions of small overlap between landscape curvature and the noise correlation function. Numerical simulations of this overlap in the context of quantum information processing reveal distinct noise spectral regimes that better support robust control solutions. This perspective shows the dual importance of both noise statistics and the control form for robustness, thereby opening up new avenues of investigation on how to mitigate noise effects in quantum systems.

  8. Selection of hydrate suppression methods for gas streams

    SciTech Connect (OSTI)

    Behrens, S.D.; Covington, K.K.; Collie, J.T. III

    1999-07-01

    This paper will discuss and compare the methods used to suppress hydrate formation in natural gas streams. Included in the comparison will be regenerated systems using ethylene glycol and non-regenerated systems using methanol. A comparison will be made between the quantities of methanol and ethylene glycol required to achieve a given a suppression. A discussion of BTEX emissions resulting from the ethylene glycol regenerator along with the effect or process variables on these emissions is also given.

  9. Newtonian-noise cancellation in full-tensor gravitational-wave detectors

    E-Print Network [OSTI]

    Jan Harms; Ho Jung Paik

    2015-04-18

    Terrestrial gravity noise, also known as Newtonian noise, produced by ambient seismic and infrasound fields will pose one of the main sensitivity limitations in low-frequency, ground-based, gravitational-wave (GW) detectors. It was estimated that this noise foreground needs to be suppressed by about 3 -- 5 orders of magnitude in the frequency band 10\\,mHz to 1\\,Hz, which will be extremely challenging. In this article, we present a new approach that greatly facilitates cancellation of gravity noise in full-tensor GW detectors. The method uses optimal combinations of tensor channels and environmental sensors such as seismometers and microphones to reduce gravity noise. It makes explicit use of the direction of propagation of a GW, and can therefore either be implemented in directional searches for GWs or in observations of known sources. We show that suppression of the Newtonian-noise foreground is greatly facilitated using the extra strain channels in full-tensor GW detectors. Only a modest number of auxiliary, high-sensitivity environmental sensors are required to achieve noise suppression by a few orders of magnitude.

  10. Title: A brief history of the Rolls-Royce University Technology Centre in Gas Turbine Noise at the Institute of Sound and Vibration Research

    E-Print Network [OSTI]

    Sóbester, András

    to generation and propagation of noise from gas turbine engines. Aircraft noise is a critical technical issueReport Title: A brief history of the Rolls-Royce University Technology Centre in Gas Turbine Noise and systems engineering, gas turbine transmission systems and gas turbine noise. The UTC in gas turbine noise

  11. Title: A brief history of the Rolls-Royce University Technology Centre in Gas Turbine Noise at the Institute of Sound and Vibration Research

    E-Print Network [OSTI]

    Sóbester, András

    Report Title: A brief history of the Rolls-Royce University Technology Centre in Gas Turbine Noise and systems engineering, gas turbine transmission systems and gas turbine noise. The UTC in gas turbine noise to generation and propagation of noise from gas turbine engines. Aircraft noise is a critical technical issue

  12. White Noise, Black-body radiation and Secure communication

    E-Print Network [OSTI]

    C. Tannous; J. Langlois

    2015-06-05

    Nyquist White noise derivation based on blackbody radiation interacting with electrons in a transmission line is revisited and is shown to possibly pave the way toward secure noise-based communication systems. Encrypting a message for secure transmission might be performed by combining it with controlled noise as performed in Spread-Spectrum communication that are presently used in Telecommunication systems. Quantum communication using entanglement is another route for secure communications as demonstrated by several important experiments. Classical and Quantum noise are compared and discussed as a major constituent of secure communication.

  13. Comparative study of 2-group P1 and diffusion theories for the calculation of the neutron noise in 1D 2-region systems

    E-Print Network [OSTI]

    Demazičre, Christophe

    reactor using Green's function technique. The applicability of diffusion theory for different types-called open-loop reactor transfer function have been initiated at the Department of Nuclear EngineeringComparative study of 2-group P1 and diffusion theories for the calculation of the neutron noise

  14. Non-equilibrium Entanglement and Noise in Coupled Qubits

    E-Print Network [OSTI]

    N. Lambert; R. Aguado; T. Brandes

    2006-02-03

    We study charge entanglement in two Coulomb-coupled double quantum dots in thermal equilibrium and under stationary non-equilibrium transport conditions. In the transport regime, the entanglement exhibits a clear switching threshold and various limits due to suppression of tunneling by Quantum Zeno localisation or by an interaction induced energy gap. We also calculate quantum noise spectra and discuss the inter-dot current correlation as an indicator of the entanglement in transport experiments.

  15. A formula for charmonium suppression

    SciTech Connect (OSTI)

    Pena, C., E-mail: pena@ift.uni.wroc.pl; Blaschke, D., E-mail: blaschke@ift.uni.wroc.pl [University of Wroclaw, Institute for Theoretical Physics (Poland)

    2012-07-15

    In this work a formula for charmonium suppression obtained by Matsui in 1989 is analytically generalized for the case of complex cc-barpotential described by a 3-dimensional and isotropic time-dependent harmonic oscillator (THO). It is suggested that under certain scheme the formula can be applied to describe J/{psi} suppression in heavy-ion collisions at CERN-SPS, RHIC, and LHC with the advantage of analytical tractability.

  16. Fighting noise with noise in realistic quantum teleportation

    E-Print Network [OSTI]

    Raphael Fortes; Gustavo Rigolin

    2015-08-03

    We investigate how the efficiency of the quantum teleportation protocol is affected when the qubits involved in the protocol are subjected to noise or decoherence. We study all types of noise usually encountered in real world implementations of quantum communication protocols, namely, the bit flip, phase flip (phase damping), depolarizing, and amplitude damping noise. Several realistic scenarios are studied in which a part or all of the qubits employed in the execution of the quantum teleportation protocol are subjected to the same or different types of noise. We find noise scenarios not yet known in which more noise or less entanglement lead to more efficiency. Furthermore, we show that if noise is unavoidable it is better to subject the qubits to different noise channels in order to obtain an increase in the efficiency of the protocol.

  17. Suppressed Charmed B Decay

    SciTech Connect (OSTI)

    Snoek, Hella Leonie; /Vrije U., Amsterdam

    2011-11-28

    This thesis describes the measurement of the branching fractions of the suppressed charmed B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays and the non-resonant B{sup 0} {yields} D{sup (*)-} {eta}{pi}{sup +} decays in approximately 230 million {Upsilon}(4S) {yields} B{bar B} events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10{sup -6}. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle {gamma}, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle {gamma} can be performed using the decays of neutral B mesons. The B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay is sensitive to the angle {gamma} and, in comparison to the current decays that are being employed, could significantly enhance the measurement of this angle. However, the low expected branching fraction for the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay channels could severely impact the measurement. A prerequisite of the measurement of the CKM angle is the observation of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay on which this thesis reports. The BABAR experiment consists of the BABAR detector and the PEP-II e{sup +}e{sup -} collider. The design of the experiment has been optimized for the study of CP violation in the decays of neutral B mesons but is also highly suitable for the search for rare B decays such as the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay. The PEP-II collider operates at the {Upsilon}(4S) resonance and is a clean source of B{bar B} meson pairs.

  18. Noise modeling from high-permeability shields using Kirchhoff equations

    SciTech Connect (OSTI)

    Sandin, Henrik J; Volegov, Petr L; Espy, Michelle A; Matlashov, Andrei N; Savukov, Igor M; Schultz, Larry J

    2010-01-01

    Progress in the development of high-sensitivity magnetic-field measurements has stimulated interest in understanding magnetic noise of conductive materials, especially of magnetic shields (DC or rf) based on high-permeability materials and/or high-conductivity materials. For example, SQUIDs and atomic magnetometers have been used in many experiments with mu-metal shields, and additionally SQUID systems frequently have rf shielding based on thin conductive materials. Typical existing approaches to modeling noise only work with simple shield and sensor geometries while common experimental setups today consist of multiple sensor systems arbitrary shapes and complex shield geometries. With complex sensor arrays used in, for example, MEG and Ultra Low Field MRI studies the knowledge of the noise correlation between sensors is as important as the knowledge of the noise itself. This is crucial for incorporating efficient noise cancelation schemes for the system. We developed an approach that allows us to calculate the Johnson noise for any geometrically shaped shield and multiple sensor systems. The approach uses a fraction of the processing power of other approaches and with a multiple sensor system our approach not only calculates the noise for each sensor but it also calculates the noise correlation matrix between sensors. Here we will show the algorithm and examples where it can be implemented.

  19. QUANTUM NOISE THEORY FOR THE dc SQUID

    E-Print Network [OSTI]

    Koch, Roger H.

    2013-01-01

    Letters LIBRARY AND QUANTUM NOISE THEORY FOR THE de SQUIDLetters LBL 11729 QUANTUM NOISE THEORY FOR THE de SQUIDCalifornia 94720 Abstract The noise temperature of a de

  20. NOISE CONSIDERATIONS IN MILLIMETER-WAVE SPECTROMETERS

    E-Print Network [OSTI]

    Zoellner, W.D.

    2011-01-01

    Presence of Oscillator Noise," Rev. Sci. Instr. B. Leskovar,UC-37 - \\V _V MASTER NOISE CONSIDERATIONS IN MILLIMETER-WAVEUK NOISE CONSIDERATIONS IN MILLIMETER-

  1. Spectral analysis of vibratory gyro noise

    E-Print Network [OSTI]

    Kim, D; M'Closkey, RT

    2013-01-01

    Leland, “Mechanical–thermal noise in mems gyroscopes,” IEEEMechanical-thermal noise in micromachined acoustic andAnalysis of Vibratory Gyro Noise Dennis Kim and Robert M’

  2. Citizen Noise Pollution Monitoring Maisonneuve

    E-Print Network [OSTI]

    TAGora project

    Citizen Noise Pollution Monitoring Nicolas Maisonneuve Sony Computer Science Laboratory Paris pollution involving citizens and built upon the notions of participatory sensing and citizen science. We, Experimentation. Keywords Noise pollution, citizen science, sustainability, participatory sensing, geo

  3. Noise-induced Turbulence in Nonlocally Coupled Oscillators

    E-Print Network [OSTI]

    Yoji Kawamura; Hiroya Nakao; Yoshiki Kuramoto

    2007-02-22

    We demonstrate that nonlocally coupled limit-cycle oscillators subject to spatiotemporally white Gaussian noise can exhibit a noise-induced transition to turbulent states. After illustrating noise-induced turbulent states with numerical simulations using two representative models of limit-cycle oscillators, we develop a theory that clarifies the effective dynamical instabilities leading to the turbulent behavior using a hierarchy of dynamical reduction methods. We determine the parameter region where the system can exhibit noise-induced turbulent states, which is successfully confirmed by extensive numerical simulations at each level of the reduction.

  4. On noise induced Poincaré–Andronov–Hopf bifurcation

    SciTech Connect (OSTI)

    Samanta, Himadri S.; Bhattacharjee, Jayanta K.; Bhattacharyay, Arijit; Chakraborty, Sagar

    2014-12-01

    It has been numerically seen that noise introduces stable well-defined oscillatory state in a system with unstable limit cycles resulting from subcritical Poincaré–Andronov–Hopf (or simply Hopf) bifurcation. This phenomenon is analogous to the well known stochastic resonance in the sense that it effectively converts noise into useful energy. Herein, we clearly explain how noise induced imperfection in the bifurcation is a generic reason for such a phenomenon to occur and provide explicit analytical calculations in order to explain the typical square-root dependence of the oscillations' amplitude on the noise level below a certain threshold value. Also, we argue that the noise can bring forth oscillations in average sense even in the absence of a limit cycle. Thus, we bring forward the inherent general mechanism of the noise induced Hopf bifurcation naturally realisable across disciplines.

  5. The physics of phase-noise mitigation : signal and filtering using microwave-photonic generation links

    E-Print Network [OSTI]

    Loh, William, Ph. D. Massachusetts Institute of Technology

    2013-01-01

    The spectral purity of every oscillator system is limited by noise. This thesis explores the physics and measurements of noise fundamental to oscillators operating in the electrical and optical domains. Our analysis leads ...

  6. Road traffic noise modifies behaviour of a keystone species Graeme Shannon a, *

    E-Print Network [OSTI]

    Angeloni, Lisa

    Road traffic noise modifies behaviour of a keystone species Graeme Shannon a, * , Lisa M. Angeloni the influence of traffic noise on foraging and vigilance in a keystone species in North American prairie systems

  7. Noise-induced bifurcations, Multiscaling and On-Off intermittency

    E-Print Network [OSTI]

    Sebastien Aumaitre; Francois Petrelis; Kirone Mallick

    2007-10-22

    We present recent results on noise-induced transitions in a nonlinear oscillator with randomly modulated frequency. The presence of stochastic perturbations drastically alters the dynamical behaviour of the oscillator: noise can wash out a global attractor but can also have a constructive role by stabilizing an unstable fixed point. The random oscillator displays a rich phenomenology but remains elementary enough to allow for exact calculations: this system is thus a useful paradigm for the study of noise-induced bifurcations and is an ideal testing ground for various mathematical techniques. We show that the phase is determined by the sign of the Lyapunov exponent (which can be calculated non-perturbatively for white noise), and we derive the full phase diagram of the system. We also investigate the effect of time-correlations of the noise on the phase diagram and show that a smooth random perturbation is less efficient than white noise. We study the critical behaviour near the transition and explain why noise-induced transitions often exhibit intermittency and multiscaling: these effects do not depend on the amplitude of the noise but rather on its power spectrum. By increasing or filtering out the low frequencies of the noise, intermittency and multiscaling can be enhanced or eliminated.

  8. Colored-noise magnetization dynamics: from weakly to strongly correlated noise

    E-Print Network [OSTI]

    Tranchida, Julien; Nicolis, Stam

    2015-01-01

    Statistical averaging theorems allow us to derive a set of equations for the averaged magnetization dynamics in the presence of colored (non-Markovian) noise. The non-Markovian character of the noise is described by a finite auto-correlation time, tau, that can be identified with the finite response time of the thermal bath to the system of interest. Hitherto, this model was only tested for the case of weakly correlated noise (when tau is equivalent or smaller than the integration timestep). In order to probe its validity for a broader range of auto-correlation times, a non-Markovian integration model, based on the stochastic Landau-Lifshitz-Gilbert equation is presented. Comparisons between the two models are discussed, and these provide evidence that both formalisms remain equivalent, even for strongly correlated noise (i.e. tau much larger than the integration timestep).

  9. Colored-noise magnetization dynamics: from weakly to strongly correlated noise

    E-Print Network [OSTI]

    Julien Tranchida; Pascal Thibaudeau; Stam Nicolis

    2015-11-06

    Statistical averaging theorems allow us to derive a set of equations for the averaged magnetization dynamics in the presence of colored (non-Markovian) noise. The non-Markovian character of the noise is described by a finite auto-correlation time, tau, that can be identified with the finite response time of the thermal bath to the system of interest. Hitherto, this model was only tested for the case of weakly correlated noise (when tau is equivalent or smaller than the integration timestep). In order to probe its validity for a broader range of auto-correlation times, a non-Markovian integration model, based on the stochastic Landau-Lifshitz-Gilbert equation is presented. Comparisons between the two models are discussed, and these provide evidence that both formalisms remain equivalent, even for strongly correlated noise (i.e. tau much larger than the integration timestep).

  10. Optical Johnson noise thermometry

    DOE Patents [OSTI]

    Shepard, Robert L. (Oak Ridge, TN); Blalock, Theron V. (Knoxville, TN); Roberts, Michael J. (Knoxville, TN); Maxey, Lonnie C. (Powell, TN)

    1992-01-01

    Method and device for direct, non-contact temperature measure of a body. A laser beam is reflected from the surface of the body and detected along with the Planck radiation. The detected signal is analyzed using signal correlation technique to generate an output signal proportional to the Johnson noise introduced into the reflected laser beam as a direct measure of the absolute temperature of the body.

  11. Soft substrates suppress droplet splashing

    E-Print Network [OSTI]

    Howland, Christopher J; Style, Robert W; Castrejón-Pita, A A

    2015-01-01

    Droplets splash when they impact dry, flat substrates above a critical velocity that depends on parameters such as droplet size, viscosity and air pressure. We show that substrate stiffness also impacts the splashing threshold by imaging ethanol drops impacting silicone gels of different stiffnesses. Splashing is significantly suppressed: droplets on the softest substrates need over 70% more kinetic energy to splash than they do on rigid substrates. We show that splash suppression is likely to be due to energy losses caused by deformations of soft substrates during the first few microseconds of impact. We find that solids with Youngs modulus $\\lesssim O(10^5)$Pa suppress splashing, in agreement with simple scaling arguments. Thus materials like soft gels and elastomers can be used as simple coatings for effective splash prevention.

  12. Dynamical Reduction Models with General Gaussian Noises

    E-Print Network [OSTI]

    Angelo Bassi; GianCarlo Ghirardi

    2002-01-27

    We consider the effect of replacing in stochastic differential equations leading to the dynamical collapse of the statevector, white noise stochastic processes with non white ones. We prove that such a modification can be consistently performed without altering the most interesting features of the previous models. One of the reasons to discuss this matter derives from the desire of being allowed to deal with physical stochastic fields, such as the gravitational one, which cannot give rise to white noises. From our point of view the most relevant motivation for the approach we propose here derives from the fact that in relativistic models the occurrence of white noises is the main responsible for the appearance of untractable divergences. Therefore, one can hope that resorting to non white noises one can overcome such a difficulty. We investigate stochastic equations with non white noises, we discuss their reduction properties and their physical implications. Our analysis has a precise interest not only for the above mentioned subject but also for the general study of dissipative systems and decoherence.

  13. Exact decoherence dynamics of $1/f$ noise

    E-Print Network [OSTI]

    Md. Manirul Ali; Ping-Yuan Lo; Wei-Min Zhang

    2014-10-06

    In this paper, we investigate the exact decoherence dynamics of a superconducting resonator coupled to an electromagnetic reservoir characterized by the $1/f$ noise at finite temperature, where a full quantum description of the environment with $1/f^{x}$ noise (with $x \\approx 1$) is presented. The exact master equation and the associated non-equilibrium Green's functions are solved exactly for such an open system. We show a clear signal of non-Markovian dynamics induced purely by $1/f$ noise. Our analysis is also applicable to another nano/micro mechanical oscillators. Finally, we demonstrate the non-Markovian decoherence dynamics of photon number superposition states using Wigner distribution that could be measured in experiments.

  14. Noise sensitivity of Boolean functions and percolation

    E-Print Network [OSTI]

    Steif, Jeffrey

    Noise sensitivity of Boolean functions and percolation Christophe Garban1 Jeffrey E. Steif2 1 ENS, Kalai, Linial theorem . . . . . . . . . . . . . . . . . . . . . 12 5 Noise sensitivity and noise stability . . . . . . . . . . . . . . . . . . . . 14 6 The Benjamini, Kalai and Schramm noise sensitivity

  15. Conquering Noise for Accurate RF and

    E-Print Network [OSTI]

    Anlage, Steven

    Conquering Noise for Accurate RF and Microwave Signal © Agilent Technologies, Inc. 2009 Microwave Signal Measurements Presented by: Ernie Jackson #12;The Noise Presentation · Review of Basics, Some Advanced & Newer Approaches · Noise in Signal Measurements-Summary · Basic Noise Reduction Approaches

  16. Noise modeling concepts in nonlinear state estimation S. Kols a,b,*, B.A. Foss a

    E-Print Network [OSTI]

    Foss, Bjarne A.

    Noise modeling concepts in nonlinear state estimation S. Kolĺs a,b,*, B.A. Foss a , T.S. Schei c Keywords: Nonlinear state estimation Constrained nonlinear systems Noise modeling Joint UKF a b s t r a c study noise modeling based on a hypothesis that it is important to model noise correctly. In practice

  17. PHYSICAL REVIEW E 91, 062102 (2015) Nonstationary filtered shot-noise processes and applications to neuronal membranes

    E-Print Network [OSTI]

    Destexhe, Alain

    2015-01-01

    in modeling the evolution of systems exposed to shot noise sources and have been applied to a wide variety are then applied to a model of neuronal membranes subject to conductance shot noise with a continuously variable with multiplicative noise. The membrane potential Vm fluctuations of neurons can be modeled as filtered shot noise

  18. New technology suppresses coke dust

    SciTech Connect (OSTI)

    Not Available

    1983-09-01

    A brief account is given of the technique of electrostatic fogging which has been tested successfully at a Canadian steel mill to control coke dust in the respirable size range. A spray of very fine droplets (<10 MUm) has an electrostatic charge imparted to each droplet. The spray of electrostatically-charged fog suppresses the dust by a combination of scrubbing and electrostatic attraction.

  19. Spatiotemporal sine-Wiener Bounded Noise and its effect on Ginzburg-Landau model

    E-Print Network [OSTI]

    Sebastiano de Franciscis; Alberto d'Onofrio

    2012-11-23

    In this work, we introduce a kind of spatiotemporal bounded noise derived by the sine-Wiener noise and by the spatially colored unbounded noise introduced by Garc\\'ia-Ojalvo, Sancho and Ram\\'irez-Piscina (GSR noise). We characterize the behavior of the distribution of this novel noise by showing its dependence on both the temporal and the spatial autocorrelation strengths. In particular, we show that the distribution experiences a stochastic transition from bimodality to trimodality. Then, we employ the noise here defined to study phase transitions on Ginzburg-Landau model. Various phenomena are evidenced by means of numerical simulations, among which re-entrant transitions, as well as differences in the response of the system to GSR noise additive perturbations. Finally, we compare the statistical behaviors induced by the sine-Wiener noise with those caused by 'equivalent' GSR noises.

  20. Entrainment of noise-induced and limit cycle oscillators under weak noise

    E-Print Network [OSTI]

    Namiko Mitarai; Uri Alon; Mogens H. Jensen

    2013-05-17

    Theoretical models that describe oscillations in biological systems are often either a limit cycle oscillator, where the deterministic nonlinear dynamics gives sustained periodic oscillations, or a noise-induced oscillator, where a fixed point is linearly stable with complex eigenvalues and addition of noise gives oscillations around the fixed point with fluctuating amplitude. We investigate how each class of model behaves under the external periodic forcing, taking the well-studied van der Pol equation as an example. We find that, when the forcing is additive, the noise-induced oscillator can show only one-to-one entrainment to the external frequency, in contrast to the limit cycle oscillator which is known to entrain to any ratio. When the external forcing is multiplicative, on the other hand, the noise-induced oscillator can show entrainment to a few ratios other than one-to-one, while the limit cycle oscillator shows entrain to any ratio. The noise blurs the entrainment in general, but clear entrainment regions for limit cycles can be identified as long as the noise is not too strong.

  1. Noise correlation in CBCT projection data and its application for noise reduction in low-dose CBCT

    SciTech Connect (OSTI)

    Zhang, Hua; Ouyang, Luo; Wang, Jing E-mail: jing.wang@utsouthwestern.edu; Ma, Jianhua E-mail: jing.wang@utsouthwestern.edu; Huang, Jing; Chen, Wufan

    2014-03-15

    Purpose: To study the noise correlation properties of cone-beam CT (CBCT) projection data and to incorporate the noise correlation information to a statistics-based projection restoration algorithm for noise reduction in low-dose CBCT. Methods: In this study, the authors systematically investigated the noise correlation properties among detector bins of CBCT projection data by analyzing repeated projection measurements. The measurements were performed on a TrueBeam onboard CBCT imaging system with a 4030CB flat panel detector. An anthropomorphic male pelvis phantom was used to acquire 500 repeated projection data at six different dose levels from 0.1 to 1.6 mAs per projection at three fixed angles. To minimize the influence of the lag effect, lag correction was performed on the consecutively acquired projection data. The noise correlation coefficient between detector bin pairs was calculated from the corrected projection data. The noise correlation among CBCT projection data was then incorporated into the covariance matrix of the penalized weighted least-squares (PWLS) criterion for noise reduction of low-dose CBCT. Results: The analyses of the repeated measurements show that noise correlation coefficients are nonzero between the nearest neighboring bins of CBCT projection data. The average noise correlation coefficients for the first- and second-order neighbors are 0.20 and 0.06, respectively. The noise correlation coefficients are independent of the dose level. Reconstruction of the pelvis phantom shows that the PWLS criterion with consideration of noise correlation (PWLS-Cor) results in a lower noise level as compared to the PWLS criterion without considering the noise correlation (PWLS-Dia) at the matched resolution. At the 2.0 mm resolution level in the axial-plane noise resolution tradeoff analysis, the noise level of the PWLS-Cor reconstruction is 6.3% lower than that of the PWLS-Dia reconstruction. Conclusions: Noise is correlated among nearest neighboring detector bins of CBCT projection data. An accurate noise model of CBCT projection data can improve the performance of the statistics-based projection restoration algorithm for low-dose CBCT.

  2. Kink instability suppression with stochastic cooling pickup and kicker

    SciTech Connect (OSTI)

    Hao Y.; Blaskiewicz, M.; Litvinenko, V.N.; Ptitsyn, V.

    2012-05-20

    The kink instability is one of the major beam dynamics issues of the linac-ring based electron ion collider. This head-tail type instability arises from the oscillation of the electron beam inside the opposing ion beam. It must be suppressed to achieve the desired luminosity. There are various ways to suppress the instability, such as tuning the chromaticity in the ion ring or by a dedicated feedback system of the electron beam position at IP, etc. However, each method has its own limitation. In this paper, we will discuss an alternative opportunity of suppressing the kink instability of the proposed eRHIC at BNL using the existing pickup-kicker system of the stochastic cooling system in RHIC.

  3. Low-noise SQUID

    DOE Patents [OSTI]

    Dantsker, Eugene (Torrance, CA); Clarke, John (Berkeley, CA)

    2000-01-01

    The present invention comprises a high-transition-temperature superconducting device having low-magnitude low-frequency noise-characteristics in magnetic fields comprising superconducting films wherein the films have a width that is less than or equal to a critical width, w.sub.C, which depends on an ambient magnetic field. For operation in the Earth's magnetic field, the critical width is about 6 micrometers (.mu.m). When made with film widths of about 4 .mu.m an inventive high transition-temperature, superconducting quantum interference device (SQUID) excluded magnetic flux vortices up to a threshold ambient magnetic field of about 100 microTesla (.mu.T). SQUIDs were fabricated having several different film strip patterns. When the film strip width was kept at about 4 .mu.m, the SQUIDs exhibited essentially no increase in low-frequency noise, even when cooled in static magnetic fields of magnitude up to 100 .mu.T. Furthermore, the mutual inductance between the inventive devices and a seven-turn spiral coil was at least 85% of that for inductive coupling to a conventional SQUID.

  4. Noise-mediated enhancements and decrements in human tactile sensation J. J. Collins,1,2

    E-Print Network [OSTI]

    Collins, James J.

    Noise-mediated enhancements and decrements in human tactile sensation J. J. Collins,1,2 Thomas T, Worcester, Massachusetts 01655 Received 31 December 1996 Recently, it has been shown that noise can enhance the detection and transmission of weak signals in certain nonlinear systems. Here we demonstrate noise

  5. Switching Exponent Scaling near Bifurcation Points for Non-Gaussian Noise Lora Billings,1

    E-Print Network [OSTI]

    Dykman, Mark

    Switching Exponent Scaling near Bifurcation Points for Non-Gaussian Noise Lora Billings,1 Ira B; published 7 April 2010) We study noise-induced switching of a system close to bifurcation parameter values where the number of stable states changes. For non-Gaussian noise, the switching exponent, which gives

  6. Phase Correction for Coherent Noise Reduction in Short-Range Radar Measurements

    E-Print Network [OSTI]

    Kansas, University of

    electromagnetic energy and geophysical media in a number of remote sensing applications. Unlike long-range and intermediate-range radar systems, the sensitivity of short-range radars is not limited by thermal noise method to account for variations in the phase of the systematic noise sources. This extends the noise

  7. Classified Comfort Noise Generation for Efficient Voice Transmission Yasheng Qian, Wei-Shou Hsu, Peter Kabal

    E-Print Network [OSTI]

    Kabal, Peter

    ); coded speech and comfort noise at the decoder (bottom). The aim of the Comfort Noise Generator (CNG with a reduced rate relative to active speech. CNG systems do not need to exactly reproduce the background noise waveform. Dif- 225 September 17-21, Pittsburgh, Pennsylvania INTERSPEECH 2006 - ICSLP #12;ferent CNG

  8. Introduction to Quantum Noise, Measurement and Amplification A.A. Clerk,1

    E-Print Network [OSTI]

    Clerk, Aashish

    and Quantum Noise 5 A. Classical noise correlators 5 B. Square law detectors and classical spectrum analyzers 6 C. Introduction to quantum noise 7 III. Quantum Spectrum Analyzers 8 A. Two-level system as a spectrum analyzer 8 B. Harmonic oscillator as a spectrum analyzer 11 C. Practical quantum spectrum

  9. Joint Uncertainty Decoding with Unscented Transform for Noise-robust Subspace Gaussian Mixture Models

    E-Print Network [OSTI]

    Edinburgh, University of

    T S C R T S C #12;Noise compensation Larger modelling power higher recognition accuracy. Our systems vector Taylor series (VTS) Model domain MLLR, noise constraint MLLR PMC, Data-driven PMC (DPMC T S C R T S C #12;Noise compensation for SGMM Model space compensation for SGMM Not data

  10. Effect of noise on time-dependent quantum chaos

    SciTech Connect (OSTI)

    Ott, E.; Antonsen T.M. Jr.; Hanson, J.D.

    1984-12-03

    The dynamics of a time-dependent quantum system can be qualitatively different from that of its classical counterpart when the latter is chaotic. It is shown that small noise can strongly alter this situation.

  11. Effects of detector censoring in nominally Gaussian noise 

    E-Print Network [OSTI]

    Sunna, Matthew Ghaleb

    2000-01-01

    In this thesis, we consider the robustness and performance of a sensor system which detects a known constant signal in additive, mutually i.i.d., nominally Gaussian noise. The detector utilizes the Huber-type detector ...

  12. Predetermining acceptable noise limits in EXAFS spectra in the limit of stochastic noise

    SciTech Connect (OSTI)

    Hu, Yung-Jin; Booth, Corwin H

    2009-12-14

    EXAFS measurements are used to probe a variety of experimental systems, but excel at elucidating local structure in samples which have slight disorder or no long-range crystalline order. Of special interest to the authors is the use of EXAFS in understanding the molecular-level binding structure and characteristics of actinides on the surface of environmental minerals and model mineral analogs. In environmental systems the element of interest can be on the order of 10-7% by weight of the total sample. Obviously such samples would be impossible to measure using EXAFS techniques. It is therefore essential to increase the concentration of the element of interest while still preserving a sample's ability to represent environmental conditions. Under such low concentration limits it is expected that the collected data is countrate, or stochastically limited. This condition occurs as we approach the signal-to-noise (S/N) limit of the technique where the random noise of the measurement process dominates over possible systematic errors. When stochastic error is expected to dominate systematic error, it is possible to predict, with the use of simulations, the ability of model fits to tolerate a certain level of stochastic noise. Elsewhere in these proceedings, we discuss how to tell when systematic errors dominate in measured EXAFS spectrum. Here, we outline a technique for determining the number of EXAFS scans necessary to test the relevance of a given structural model. Appropriate stochastic noise levels are determined for each point in r-space by collecting data on a real system. These noise levels are then applied to EXAFS simulations using a test model. In this way, all significant systematic error sources are eliminated in the simulated data. The structural model is then fit to the simulated data, decreasing the noise and increasing the k-range of the fit until the veracity of the model passes an F-test. This paper outlines a method of testing model systems in EXAFS fitting before measurements are conducted to determine the quality of measured data required for fitting of a particular model system with statistical confidence. It is important to reiterate that the calculated {alpha}surface in figure 1 is only applicable to the particular model presented in this paper. Furthermore, this procedure only takes into account stochastic noise; consequentially any confidence levels calculated should be viewed as upper limits to the confidence levels in systems which also contain a significant amount of systematic noise.

  13. Hydrodynamic noise and Bjorken expansion

    E-Print Network [OSTI]

    J. I. Kapusta; B. Müller; M. Stephanov

    2012-11-14

    Using the Bjorken expansion model we study the effect of intrinsic hydrodynamic noise on the correlations observed in heavy-ion collisions.

  14. Environmental gravitational decoherence and a tensor noise model

    E-Print Network [OSTI]

    Suzuki, Fumika

    2015-01-01

    We discuss decrease of coherence in a massive system due to the emission of gravitational waves. In particular we investigate environmental gravitational decoherence in the context of an interference experiment. The time-evolution of the reduced density matrix is solved analytically using the path-integral formalism. Furthermore, we study the impact of a tensor noise onto the coherence properties of massive systems. We discuss that a particular choice of tensor noise shows similarities to a mechanism proposed by Diosi and Penrose.

  15. Environmental gravitational decoherence and a tensor noise model

    E-Print Network [OSTI]

    Fumika Suzuki; Friedemann Queisser

    2015-02-04

    We discuss decrease of coherence in a massive system due to the emission of gravitational waves. In particular we investigate environmental gravitational decoherence in the context of an interference experiment. The time-evolution of the reduced density matrix is solved analytically using the path-integral formalism. Furthermore, we study the impact of a tensor noise onto the coherence properties of massive systems. We discuss that a particular choice of tensor noise shows similarities to a mechanism proposed by Diosi and Penrose.

  16. Brain&oscillations&mediate&memory&suppression&1! Running&Title:&BRAIN&OSCILLATIONS&MEDIATE&MEMORY&SUPPRESSION&

    E-Print Network [OSTI]

    Schubart, Christoph

    Brain&oscillations&mediate&memory&suppression&1! & ! Running&Title:&BRAIN&OSCILLATIONS&MEDIATE&MEMORY&SUPPRESSION& & & Brain&oscillations&mediate&successful&suppression&of&unwanted&memories& Gerd&T.&Waldhauser1,&Karl1Heinz.de& Phone:&+49(0)753118815707& Fax:&+49(0)753118814829& #12;Brain&oscillations&mediate&memory&suppression&2

  17. Blast Effects Suppression System - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L O OLaura|BilayerBiomimetic Dye MoleculesBlake Case BlakeBlast

  18. Emergency generator facility noise control

    SciTech Connect (OSTI)

    Cass, G.R.

    1982-01-01

    In the past decade, great strides have been made in the adoption of noise control regulations and implementation of noise control measures; however, still prevelant are problems in the interpretation and enforcement of these regulations. Many planning commissions, building departments, and other local government officials are not aware of acoustical nomenclature and principles, although their responsibilities include making binding decisions regarding their community's noise control programs. This paper discusses a project undertaken by Dames and Moore to aid a developer to comply with strict noise regulation. Construction called for a computer/office complex in a light industrial park, located adjacent to an established suburban residential neighborhood. The major noise source consisted of an emergency generating facility including twelve-1200 kw diesel generators, twelve rooftop-mounted radiator units, six rooftop-mounted 20-hp, 50,000 cfm vaneaxial exhaust fans, and four 100-hp cooling towers.

  19. Multiplicative or t1 Noise in NMR Spectroscopy

    SciTech Connect (OSTI)

    Granwehr, Josef

    2005-01-25

    The signal in an NMR experiment is highly sensitive to fluctuations of the environment of the sample. If, for example, the static magnetic field B{sub 0}, the amplitude and phase of radio frequency (rf) pulses, or the resonant frequency of the detection circuit are not perfectly stable and reproducible, the magnetic moment of the spins is altered and becomes a noisy quantity itself. This kind of noise not only depends on the presence of a signal, it is in fact proportional to it. Since all the spins at a particular location in a sample experience the same environment at any given time, this noise primarily affects the reproducibility of an experiment, which is mainly of importance in the indirect dimensions of a multidimensional experiment, when intense lines are suppressed with a phase cycle, or for difference spectroscopy techniques. Equivalently, experiments which are known to be problematic with regard to their reproducibility, like flow experiments or experiments with a mobile target, tend to be affected stronger by multiplicative noise. In this article it is demonstrated how multiplicative noise can be identified and characterized using very simple, repetitive experiments. An error estimation approach is developed to give an intuitive, yet quantitative understanding of its properties. The consequences for multidimensional NMR experiments are outlined, implications for data analysis are shown, and strategies for the optimization of experiments are summarized.

  20. Fire suppression and detection equipment

    SciTech Connect (OSTI)

    E.E. Bates [HSB Professional Loss Control, Lexington, KY (United States)

    2006-01-15

    Inspection and testing guidelines go beyond the 'Code of Federal Regulation'. Title 30 of the US Code of Federal Regulations (30 CFR) contains requirements and references to national standards for inspection, testing and maintenance of fire suppression and detection equipment for mine operators. However, federal requirements have not kept pace with national standards and best practices. The article lists National Fire Protection (NFPA) standards that are referenced by the US Mine Safety and Health Administration (MSHA) in 30 CFR. It then discusses other NFPA Standards excluded from 30 CFR and explains the NFPA standard development process. 2 refs., 3 tabs., 5 photos.

  1. TH-A-18C-03: Noise Correlation in CBCT Projection Data and Its Application for Noise Reduction in Low-Dose CBCT

    SciTech Connect (OSTI)

    ZHANG, H; Huang, J; Ma, J; Chen, W; Ouyang, L; Wang, J

    2014-06-15

    Purpose: To study the noise correlation properties of cone-beam CT (CBCT) projection data and to incorporate the noise correlation information to a statistics-based projection restoration algorithm for noise reduction in low-dose CBCT. Methods: In this study, we systematically investigated the noise correlation properties among detector bins of CBCT projection data by analyzing repeated projection measurements. The measurements were performed on a TrueBeam on-board CBCT imaging system with a 4030CB flat panel detector. An anthropomorphic male pelvis phantom was used to acquire 500 repeated projection data at six different dose levels from 0.1 mAs to 1.6 mAs per projection at three fixed angles. To minimize the influence of the lag effect, lag correction was performed on the consecutively acquired projection data. The noise correlation coefficient between detector bin pairs was calculated from the corrected projection data. The noise correlation among CBCT projection data was then incorporated into the covariance matrix of the penalized weighted least-squares (PWLS) criterion for noise reduction of low-dose CBCT. Results: The analyses of the repeated measurements show that noise correlation coefficients are non-zero between the nearest neighboring bins of CBCT projection data. The average noise correlation coefficients for the first- and second- order neighbors are about 0.20 and 0.06, respectively. The noise correlation coefficients are independent of the dose level. Reconstruction of the pelvis phantom shows that the PWLS criterion with consideration of noise correlation (PWLS-Cor) results in a lower noise level as compared to the PWLS criterion without considering the noise correlation (PWLS-Dia) at the matched resolution. Conclusion: Noise is correlated among nearest neighboring detector bins of CBCT projection data. An accurate noise model of CBCT projection data can improve the performance of the statistics-based projection restoration algorithm for low-dose CBCT.

  2. Salt-and-Pepper Noise Removal by Median-type Noise Detectors and

    E-Print Network [OSTI]

    Chan, Raymond

    1 Salt-and-Pepper Noise Removal by Median-type Noise Detectors and Detail-preserving Regularization for removing salt-and-pepper impulse noise. In the first phase, an adaptive median filter is used to identify remove salt-and-pepper-noise with noise level as high as 90%. Index Terms Impulse noise, adaptive median

  3. NOISE AND OPTIMIZATION OF THE dc SQUID

    E-Print Network [OSTI]

    Tesche, Claudia Denke

    2011-01-01

    unpublished). A. Van der Ziel, Noise (Prentice-Hall, Inc. ,MAY 29 19ft LBL-8510 MASTER NOISE AND OPTIMIZATION OF THE deW-7405-ENG-48 LBL-8510 NOISE AND OPTIMIZATION OF THE dc

  4. Noise Injection for Search Privacy Protection

    E-Print Network [OSTI]

    Ye, Shaozhi; Wu, S F; Pandey, Raju; Chen, Hao

    2009-01-01

    W. Gray, “On introducing noise into the bus-contention chan-R. Pandey, and H. Chen, “Noise injection for search privacyNoise Injection for Search Privacy Protection Shaozhi Ye,

  5. Stimulus-dependent suppression of chaos in recurrent neural networks

    SciTech Connect (OSTI)

    Rajan, Kanaka; Abbott, L. F.; Sompolinsky, Haim [Lewis-Sigler Institute for Integrative Genomics, Icahn 262, Princeton University, Princeton, New Jersey 08544 (United States); Department of Neuroscience and Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, New York 10032-2695 (United States); Racah Institute of Physics, Interdisciplinary Center for Neural Computation, Hebrew University, Jerusalem (Israel)

    2010-07-15

    Neuronal activity arises from an interaction between ongoing firing generated spontaneously by neural circuits and responses driven by external stimuli. Using mean-field analysis, we ask how a neural network that intrinsically generates chaotic patterns of activity can remain sensitive to extrinsic input. We find that inputs not only drive network responses, but they also actively suppress ongoing activity, ultimately leading to a phase transition in which chaos is completely eliminated. The critical input intensity at the phase transition is a nonmonotonic function of stimulus frequency, revealing a 'resonant' frequency at which the input is most effective at suppressing chaos even though the power spectrum of the spontaneous activity peaks at zero and falls exponentially. A prediction of our analysis is that the variance of neural responses should be most strongly suppressed at frequencies matching the range over which many sensory systems operate.

  6. TITLE: ACTIVE VIBRATION SUPPRESSION OF SMART STRUCTURES USING PIEZOELECTRIC SHEAR ACTUATORS

    E-Print Network [OSTI]

    Vel, Senthil

    TITLE: ACTIVE VIBRATION SUPPRESSION OF SMART STRUCTURES USING PIEZOELECTRIC SHEAR ACTUATORS Authors Current active vibration suppression systems usually consist of piezoelectric extension actuators bonded of polarization to cause shear deformation of the material. We present an exact analysis and active vibration

  7. IEEE SENSORS JOURNAL, VOL. 3, NO. 5, OCTOBER 2003 595 Active Structural Error Suppression in MEMS

    E-Print Network [OSTI]

    Chen, Zhongping

    -run perturbations are presented. Index Terms--Error suppression, microelectromechanical sys- tems (MEMS), rate integrating gyroscopes, smart MEMS. I. INTRODUCTION AS MICROELECTROMECHANICAL systems (MEMS) inertial sensorsIEEE SENSORS JOURNAL, VOL. 3, NO. 5, OCTOBER 2003 595 Active Structural Error Suppression in MEMS

  8. Simple criteria for noise resistance of two qudit entanglement

    E-Print Network [OSTI]

    Arijit Dutta; Junghee Ryu; Wieslaw Laskowski; Marek Zukowski

    2015-09-01

    Too much noise kills entanglement. This is the main problem in its production and transmission. We use a handy approach to indicate noise resistance of entanglement of a bi-partite system described by $d\\times d$ Hilbert space. Our analysis uses a geometric approach based on the fact that if a scalar product of a vector $\\vec{s}$ with a vector $\\vec {e}$ is less than the square of the norm of $\\vec{e}$, then $\\vec{s}\

  9. Analysis of kicker noise induced beam emittance growth

    SciTech Connect (OSTI)

    Zhang W.; Sandberg, J.; Ahrens, L.; Blacker, I.M.; Brennan, M.; Blaskiewicz, M.; Fischer, W.; Hahn, H.; Huang, H.; Kling, N.; Lafky, M.; Marr, G.; Mernick, K.; Mi, J.; Minty, M.; Naylor, C.; Roser, T.; Shrey, T.; van Kuik, B.; Zelenski, A.

    2012-05-20

    Over the last few years, physicists have occasionally observed the presence of noise acting on the RHIC beams leading to emittance growth at high beam energies. While the noise was sporadic in the past, it became persistent during the Run-11 setup period. An investigation diagnosed the source as originating from the RHIC dump kicker system. Once identified the issue was quickly resolved. We report in this paper the investigation result, circuit analysis, measured and simulated waveforms, solutions, and future plans.

  10. Paired carriers as a way to reduce quantum noise of multi-carrier gravitational-wave detectors

    E-Print Network [OSTI]

    Mikhail Korobko; Nikita Voronchev; Haixing Miao; Farid Ya. Khalili

    2014-09-23

    We explore new regimes of laser interferometric gravitational-wave detectors with multiple optical carriers which allow to reduce the quantum noise of these detectors. In particular, we show that using two carriers with the opposite detunings, homodyne angles, and squeezing angles, but identical other parameters (the antisymmetric carriers), one can suppress the quantum noise in such a way that its spectrum follows the Standard Quantum Limit (SQL) at low frequencies. Relaxing this antisymmetry condition, it is also possible to slightly overcome the SQL in broadband. Combining several such pairs in the xylophone configuration, it is possible to shape the quantum noise spectrum flexibly.

  11. Noise as Information for Illiquidity

    E-Print Network [OSTI]

    Hu, Grace Xing

    We propose a market-wide liquidity measure by exploiting the connection between the amount of arbitrage capital in the market and observed “noise” in U.S. Treasury bonds—the shortage of arbitrage capital allows yields to ...

  12. Another approach to the study of phase noise in electrical oscillators

    E-Print Network [OSTI]

    Carlŕ, Marcello

    2015-01-01

    The mechanism at the base of phase noise generation in electrical oscillators is reexamined from first principles. The well known Lorentzian spectral power distribution is obtained, together with a clearcut expression for the line-width parameter. The mechanism of suppression of the amplitude fluctuations and its effects are discussed and the true role of the figure of merit $Q_0$ of the resonator is restated. The up conversion of low frequency components from a non-white noise source is also considered. A number of simple numerical experiments is presented to illustrate and clarify the mathematical results.

  13. Another approach to the study of phase noise in electrical oscillators

    E-Print Network [OSTI]

    Marcello Carlŕ

    2015-04-23

    The mechanism at the base of phase noise generation in electrical oscillators is reexamined from first principles. The well known Lorentzian spectral power distribution is obtained, together with a clearcut expression for the line-width parameter. The mechanism of suppression of the amplitude fluctuations and its effects are discussed and the true role of the figure of merit $Q_0$ of the resonator is restated. The up conversion of low frequency components from a non-white noise source is also considered. A number of simple numerical experiments is presented to illustrate and clarify the mathematical results.

  14. Multiple phase estimation for arbitrary pure states under white noise

    E-Print Network [OSTI]

    Yao Yao; Li Ge; Xing Xiao; Xiaoguang Wang; C. P. Sun

    2014-09-08

    In any realistic quantum metrology scenarios, the ultimate precision in the estimation of parameters is limited not only by the so-called Heisenberg scaling, but also the environmental noise encountered by the underlying system. In the context of quantum estimation theory, it is of great significance to carefully evaluate the impact of a specific type of noise on the corresponding quantum Fisher information (QFI) or quantum Fisher information matrix (QFIM). Here we investigate the multiple phase estimation problem for a natural parametrization of arbitrary pure states under white noise. We obtain the explicit expression of the symmetric logarithmic derivative (SLD) and hence the analytical formula of QFIM. Moreover, the attainability of the quantum Cram\\'{e}r-Rao bound (QCRB) is confirmed by the commutability of SLDs and the optimal estimators are elucidated for the experimental purpose. These findings generalize previously known partial results and highlight the role of white noise in quantum metrology.

  15. Noise spectroscopy of an optical microresonator

    SciTech Connect (OSTI)

    Kozlov, G. G.

    2013-05-15

    The noise spectrum is calculated for the intensity of light transmitted through an optical microresonator whose thickness experiences thermal oscillations. The noise spectrum reveals a maximum at the frequency of an acoustic mode localized in the optical microresonator and depends on the size of the illuminated region. The noise intensity estimates show that it can be detected by the modern noise spectroscopy technique.

  16. External noise yields a What template?

    E-Print Network [OSTI]

    Klein, Stanley

    External noise yields a surprise: What template? Stanley Klein, Dennis Levi, Suko Toyofuku Vision Science University of California, Berkeley #12;Overview Detection of patterns in noise Why noise masking is a powerful technique The Lu-Dosher framework: useful black boxes Graham-Nachmias experiment in noise (detect

  17. 5th International Meeting Wind Turbine Noise

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 5th International Meeting on Wind Turbine Noise Denver 28 ­ 30 August 2013 Wind Turbine Noise Broadband noise generated aerodynamically is the dominant noise source for a modern wind turbine(Brooks et turbines . First, a wall pressure spectral model proposed recently by Rozenberg, Robert and Moreau

  18. Noise Compensation for Subspace Gaussian Mixture Models

    E-Print Network [OSTI]

    Edinburgh, University of

    Noise Compensation for Subspace Gaussian Mixture Models Liang Lu University of Edinburgh Joint work condition (i.e. noise), the gain disappears Goal Noise compensation for SGMM Method Model space compensation . . .· · · · · · · · · · ·· · ·· · ···· · ·· · ·· vjk Liang Lu, Interspeech, September, 2012 R T S C R T S C #12;Noise compensation Larger modelling

  19. Simulation of noise-assisted transport via optical cavity networks

    E-Print Network [OSTI]

    Filippo Caruso; Nicolň Spagnolo; Chiara Vitelli; Fabio Sciarrino; Martin B. Plenio

    2010-10-26

    Recently, the presence of noise has been found to play a key role in assisting the transport of energy and information in complex quantum networks and even in biomolecular systems. Here we propose an experimentally realizable optical network scheme for the demonstration of the basic mechanisms underlying noise-assisted transport. The proposed system consists of a network of coupled quantum optical cavities, injected with a single photon, whose transmission efficiency can be measured. Introducing dephasing in the photon path this system exhibits a characteristic enhancement of the transport efficiency that can be observed with presently available technology.

  20. Resolving small signal measurements in experimental plasma environments using calibrated subtraction of noise signals

    SciTech Connect (OSTI)

    Fimognari, P. J. Demers, D. R.; Chen, X.; Schoch, P. M.

    2014-11-15

    The performance of many diagnostic and control systems within fusion and other fields of research are often detrimentally affected by spurious noise signals. This is particularly true for those (such as radiation or particle detectors) working with very small signals. Common sources of radiated and conducted noise in experimental fusion environments include the plasma itself and instrumentation. The noise complicates data analysis, as illustrated by noise on signals measured with the heavy ion beam probe (HIBP) installed on the Madison Symmetric Torus. The noise is time-varying and often exceeds the secondary ion beam current (in contrast with previous applications). Analysis of the noise identifies the dominant source as photoelectric emission from the detectors induced by ultraviolet light from the plasma. This has led to the development of a calibrated subtraction technique, which largely removes the undesired temporal noise signals from data. The advantages of the technique for small signal measurement applications are demonstrated through improvements realized on HIBP fluctuation measurements.

  1. Listening to Noise

    E-Print Network [OSTI]

    Michael G. Endres; David B. Kaplan; Jong-Wan Lee; Amy N. Nicholson

    2011-12-17

    We show how sign problems in simulations of many-body systems can manifest themselves in the form of heavy-tailed correlator distributions, similar to what is seen in electron propagation through disordered media. We propose an alternative statistical approach for extracting ground state energies in such systems, illustrating the method with a toy model and with lattice data for unitary fermions and for baryons in QCD.

  2. Novel approaches to Newtonian noise suppression in interferometric gravitational wave detection

    E-Print Network [OSTI]

    Hunter-Jones, Nicholas R

    2011-01-01

    The Laser Interferometer Gravitational-wave Observatory (LIGO) attempts to detect ripples in the curvature of spacetime using two large scale interferometers. These detectors are several kilometer long Michelson interferometers ...

  3. Techniques for noise suppression and robust control in spin-based quantum information processors

    E-Print Network [OSTI]

    Borneman, Troy William

    2013-01-01

    Processing information quantum mechanically allows the relatively efficient solution of many important problems thought to be intractable on a classical computer. A primary challenge in experimentally implementing a quantum ...

  4. Quantifying precipitation suppression due to air Pollution

    E-Print Network [OSTI]

    Li, Zhanqing

    Quantifying precipitation suppression due to air Pollution First author: Amir Givati The Hebrew January 2004 #12;ABSTRACT: Urban and industrial air pollution has been shown qualitatively to suppress. The evidence suggests that air pollution aerosols that are incorporated in orographic clouds slow down cloud

  5. Spin noise spectroscopy of ZnO

    SciTech Connect (OSTI)

    Horn, H.; Berski, F.; Hübner, J.; Oestreich, M.; Balocchi, A.; Marie, X.; Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A.

    2013-12-04

    We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.

  6. Editing Noise Noise is used to create realistic animations that look

    E-Print Network [OSTI]

    Lee, In-Kwon

    Editing Noise Abstract Noise is used to create realistic animations that look like natural. In this paper, we suggest a method to edit noise values to satisfy the constraints that reflect the user's demands while maintaining the inherent statistical features of the noise function. Noise editing uses

  7. Quantum noise effects with Kerr nonlinearity enhancement in coupled gain-loss waveguides

    E-Print Network [OSTI]

    Bing He; Shu-Bin Yan; Jing Wang; Min Xiao

    2015-05-26

    It is generally difficult to study the dynamical properties of a quantum system with both inherent quantum noises and non-perturbative nonlinearity. Due to the possibly drastic intensity increase of an input coherent light in the gain-loss waveguide couplers with parity-time (PT) symmetry, the Kerr effect from a nonlinearity added into the systems can be greatly enhanced, and is expected to create the macroscopic entangled states of the output light fields with huge photon numbers. Meanwhile, the quantum noises also coexist with the amplification and dissipation of the light fields. Under the interplay between the quantum noises and nonlinearity, the quantum dynamical behaviors of the systems become rather complicated. However, the important quantum noise effects have been mostly neglected in the previous studies about nonlinear PT-symmetric systems. Here we present a solution to this non-perturbative quantum nonlinear problem, showing the real-time evolution of the system observables. The enhanced Kerr nonlinearity is found to give rise to a previously unknown decoherence effect that is irrelevant to the quantum noises, and imposes a limit on the emergence of macroscopic nonclassicality. In contrast to what happen in the linear systems, the quantum noises exert significant impact on the system dynamics, and can create the nonclassical light field states in conjunction with the enhanced Kerr nonlinearity. This first study on the noise involved quantum nonlinear dynamics of the coupled gain-loss waveguides can help to better understand the quantum noise effects in the broad nonlinear systems.

  8. Effect of Random Parameter Switching on Commensurate Fractional Order Chaotic Systems

    E-Print Network [OSTI]

    Saptarshi Das; Indranil Pan; Shantanu Das

    2015-07-21

    The paper explores the effect of random parameter switching in a fractional order (FO) unified chaotic system which captures the dynamics of three popular classes of chaotic systems i.e. Lorenz, Lu and Chen's attractors. The appearance of chaos and hyper-chaos in such systems which continuously switches from one family to the other has been investigated here for a commensurate fractional order system scenario. Our simulation study shows that noise like random variation in the unified chaotic system key parameter along with gradual decrease in the commensurate FO of the model is capable of suppressing the chaotic fluctuations much earlier than the fixed parameter one. Such a noise-like random switching mechanism could be useful for stabilization and control of chaotic oscillation in many real-world applications.

  9. Review of Flicker Noise Spectroscopy in Electrochemistry

    E-Print Network [OSTI]

    Timashev, Serge F; 10.1142/S0219477507003829

    2008-01-01

    This review presents the fundamentals of Flicker-Noise Spectroscopy (FNS), a general phenomenological methodology in which the dynamics and structure of complex systems, characterized by nonlinear interactions, dissipation, and inertia, are analyzed by extracting information from various signals with stochastically varying components generated by the systems. The basic idea of FNS is to treat the correlation links present in sequences of different irregularities, such as spikes, "jumps", and discontinuities in derivatives of different orders, on all levels of the spatiotemporal hierarchy of the system under study as main information carriers. The tools to extract and analyze the information are power spectra and difference moments (structural functions) of various orders. Presently, FNS can be applied to three types of problems: (1) determination of parameters or patterns that characterize the dynamics or structural features of complex systems; (2) finding precursors of abrupt changes in the state of various ...

  10. Low noise optical position sensor

    DOE Patents [OSTI]

    Spear, Jonathan David (Berkeley, CA)

    1999-01-01

    A novel optical position sensor is described that uses two component photodiodes electrically connected in parallel, with opposing polarities. A lens provides optical gain and restricts the acceptance angle of the detector. The response of the device to displacements of an optical spot is similar to that of a conventional bi-cell type position sensitive detector. However, the component photodiode design enables simpler electronic amplification with inherently less electrical noise than the bi-cell. Measurements by the sensor of the pointing noise of a focused helium-neon laser as a function of frequency demonstrate high sensitivity and suitability for optical probe beam deflection experiments.

  11. Laser Noise Reduction in Air

    E-Print Network [OSTI]

    Pierre Bejot; Jerome Kasparian; Estelle Salmon; Roland Ackermann; Nicolas Gisin; Jean-Pierre Wolf

    2006-08-09

    Fluctuations of the white-light supercontinuum produced by ultrashort laser pulses in selfguided filaments (spatio-temporal solitons) in air are investigated. We demonstrate that correlations exist within the white-light supercontinuum, and that they can be used to significantly reduce the laser intensity noise by filtering the spectrum. More precisely, the fundamental wavelength is anticorrelated with the wings of the continuum, while conjugated wavelength pairs on both sides of the continuum are strongly correlated. Spectral filtering of the continuum reduces the laser intensity noise by 1.2 dB, showing that fluctuations are rejected to the edges of the spectrum.

  12. Predetermining acceptable noise limits in EXAFS spectra in the limit of stochastic noise

    E-Print Network [OSTI]

    Hu, Yung-Jin

    2010-01-01

    Predetermining acceptable noise limits of EXAFS spectrain the limit of stochastic noise Yung-Jin Hu 1 and Corwin H.The e?ect of stochastic noise on Extended X-ray Absorption

  13. Noise variance analysis using a flat panel x-ray detector: A method for additive noise assessment with application to breast CT applications

    SciTech Connect (OSTI)

    Yang Kai; Huang, Shih-Ying; Packard, Nathan J.; Boone, John M. [Department of Radiology, University of California, Davis Medical Center, 4860 Y Street, Suite 3100 Ellison Building, Sacramento, California 95817 (United States); Department of Radiology, University of California, Davis Medical Center, 4860 Y Street, Suite 3100 Ellison Building, Sacramento, California 95817 (United States) and Department of Biomedical Engineering, University of California, Davis, Davis, California, 95616 (United States)

    2010-07-15

    Purpose: A simplified linear model approach was proposed to accurately model the response of a flat panel detector used for breast CT (bCT). Methods: Individual detector pixel mean and variance were measured from bCT projection images acquired both in air and with a polyethylene cylinder, with the detector operating in both fixed low gain and dynamic gain mode. Once the coefficients of the linear model are determined, the fractional additive noise can be used as a quantitative metric to evaluate the system's efficiency in utilizing x-ray photons, including the performance of different gain modes of the detector. Results: Fractional additive noise increases as the object thickness increases or as the radiation dose to the detector decreases. For bCT scan techniques on the UC Davis prototype scanner (80 kVp, 500 views total, 30 frames/s), in the low gain mode, additive noise contributes 21% of the total pixel noise variance for a 10 cm object and 44% for a 17 cm object. With the dynamic gain mode, additive noise only represents approximately 2.6% of the total pixel noise variance for a 10 cm object and 7.3% for a 17 cm object. Conclusions: The existence of the signal-independent additive noise is the primary cause for a quadratic relationship between bCT noise variance and the inverse of radiation dose at the detector. With the knowledge of the additive noise contribution to experimentally acquired images, system modifications can be made to reduce the impact of additive noise and improve the quantum noise efficiency of the bCT system.

  14. Quantum Noise Filtering via Cross-Correlations

    E-Print Network [OSTI]

    Boaz Tamir; Eliahu Cohen

    2015-04-04

    Motivated by successful classical models for noise reduction, we suggest a quantum technique for filtering noise out of quantum states. The purpose of this paper is twofold: presenting a simple construction of quantum cross-correlations between two wave-functions, and presenting a scheme for a quantum noise filtering. We follow a well-known scheme in classical communication theory that attenuates random noise, and show that one can build a quantum analog by using non-trace-preserving operators. By this we introduce a classically motivated signal processing scheme to quantum information theory, which can help reducing quantum noise, and particularly, phase flip noise.

  15. Amplification induced by white noise

    E-Print Network [OSTI]

    Masamichi Ishihara

    2006-03-01

    We investigate the amplification of the field induced by white noise. In the present study, we study a stochastic equation which has two parameters, the energy $\\omega(\\vec{k})$ of a free particle and the coupling strength $D$ between the field and white noise, where the quantity $\\vec{k}$ represents the momentum of a free particle. This equation is reduced to the equation with one parameter $\\alpha(\\vec{k})$ which is defined as $\\alpha(\\vec{k}) = D (\\omega(\\vec{k}))^{-3/2}$. We obtain the expression of the exponent statistically averaged over the unit time and derive an approximate expression of it. In addition, the exponent is obtained numerically by solving the stochastic equation. We find that the amplification increases with $\\alpha(\\vec{k})$. This indicates that white noise can amplify the fields for soft modes if the mass $m$ of the field is sufficiently light and if the strength of the coupling between the field and white noise is sufficiently strong, when the energy $\\omega(\\vec{k})$ is equal to $\\sqrt{m^{2} + \\vec{k}^{2}}$. We show that the $\\alpha(\\vec{k})$ dependence of the exponent statistically averaged is qualitatively similar to that of the exponent obtained by solving the stochastic equation numerically, and that these two exponents for the small value of $\\alpha(\\vec{k})$ are quantitatively similar.

  16. Noise Properties of Rectifying Nanopores

    SciTech Connect (OSTI)

    Powell, M R; Sa, N; Davenport, M; Healy, K; Vlassiouk, I; Letant, S E; Baker, L A; Siwy, Z S

    2011-02-18

    Ion currents through three types of rectifying nanoporous structures are studied and compared for the first time: conically shaped polymer nanopores, glass nanopipettes, and silicon nitride nanopores. Time signals of ion currents are analyzed by power spectrum. We focus on the low-frequency range where the power spectrum magnitude scales with frequency, f, as 1/f. Glass nanopipettes and polymer nanopores exhibit non-equilibrium 1/f noise, thus the normalized power spectrum depends on the voltage polarity and magnitude. In contrast, 1/f noise in rectifying silicon nitride nanopores is of equilibrium character. Various mechanisms underlying the voltage-dependent 1/f noise are explored and discussed, including intrinsic pore wall dynamics, and formation of vortices and non-linear flow patterns in the pore. Experimental data are supported by modeling of ion currents based on the coupled Poisson-Nernst-Planck and Navier Stokes equations. We conclude that the voltage-dependent 1/f noise observed in polymer and glass asymmetric nanopores might result from high and asymmetric electric fields inducing secondary effects in the pore such as enhanced water dissociation.

  17. Spatio-temporal Bounded Noises, and transitions induced by them in solutions of real Ginzburg-Landau model

    E-Print Network [OSTI]

    Sebastiano de Franciscis; Alberto d'Onofrio

    2012-05-23

    In this work, we introduce two spatio-temporal colored bounded noises, based on the zero-dimensional Cai-Lin and Tsallis-Borland noises. We then study and characterize the dependence of the defined bounded noises on both a temporal correlation parameter $\\tau$ and on a spatial coupling parameter $\\lambda$. The boundedness of these noises has some consequences on their equilibrium distributions. Indeed in some cases varying $\\lambda$ may induce a transition of the distribution of the noise from bimodality to unimodality. With the aim to study the role played by bounded noises on nonlinear dynamical systems, we investigate the behavior of the real Ginzburg-Landau time-varying model additively perturbed by such noises. The observed phase transitions phenomenology is quite different from the one observed when the perturbations are unbounded. In particular, we observed an inverse "order-to-disorder" transition, and a re-entrant transition, with dependence on the specific type of bounded noise.

  18. Suppression of Grain Boundaries in Graphene Growth on Superstructured...

    Office of Scientific and Technical Information (OSTI)

    Suppression of Grain Boundaries in Graphene Growth on Superstructured Mn-Cu(111) Surface Prev Next Title: Suppression of Grain Boundaries in Graphene Growth on...

  19. Channel noise induced stochastic facilitation in an auditory brainstem neuron model

    E-Print Network [OSTI]

    Brett A. Schmerl; Mark D. McDonnell

    2013-12-05

    Neuronal membrane potentials fluctuate stochastically due to conductance changes caused by random transitions between the open and close states of ion channels. Although it has previously been shown that channel noise can nontrivially affect neuronal dynamics, it is unknown whether ion-channel noise is strong enough to act as a noise source for hypothesised noise-enhanced information processing in real neuronal systems, i.e. 'stochastic facilitation.' Here, we demonstrate that biophysical models of channel noise can give rise to two kinds of recently discovered stochastic facilitation effects in a Hodgkin-Huxley-like model of auditory brainstem neurons. The first, known as slope-based stochastic resonance (SBSR), enables phasic neurons to emit action potentials that can encode the slope of inputs that vary slowly relative to key time-constants in the model. The second, known as inverse stochastic resonance (ISR), occurs in tonically firing neurons when small levels of noise inhibit tonic firing and replace it with burst-like dynamics. Consistent with previous work, we conclude that channel noise can provide significant variability in firing dynamics, even for large numbers of channels. Moreover, our results show that possible associated computational benefits may occur due to channel noise in neurons of the auditory brainstem. This holds whether the firing dynamics in the model are phasic (SBSR can occur due to channel noise) or tonic (ISR can occur due to channel noise).

  20. Sudden Noise Reduction Based on GMM with Noise Power Estimation Nobuyuki Miyake, Tetsuya Takiguchi and Yasuo Ariki

    E-Print Network [OSTI]

    Takiguchi, Tetsuya

    Sudden Noise Reduction Based on GMM with Noise Power Estimation Nobuyuki Miyake, Tetsuya Takiguchi sudden noise using noise detection and classification methods, and noise power es- timation. Sudden noise detection and classification have been dealt with in our previous study. In this paper, noise classifi

  1. Noise Reduced Realized Volatility: A Kalman Filter Approach

    E-Print Network [OSTI]

    Owens, John; Steigerwald, Douglas G

    2009-01-01

    F. , 2004. Microstructure Noise, Realized Volatility, andof Market Microstructure Noise. Working Paper w9611, NBER.Noise Reduced Realized Volatility: A Kalman Filter Approach

  2. Modeling long-period noise in kinematic GPS applications

    E-Print Network [OSTI]

    Borsa, Adrian A; Minster, J B; Bills, B G; Fricker, H A

    2007-01-01

    show that removing the noise model dramatically attenuatespreferentially return noise models with a spectral index2 after correction for GPS noise model calculated in this

  3. Listening to the noise: random fluctuations reveal gene network...

    Office of Scientific and Technical Information (OSTI)

    Title: Listening to the noise: random fluctuations reveal gene network parameters The cellular environment is abuzz with noise. The origin of this noise is attributed to the...

  4. Noise analysis for comparator-based circuits

    E-Print Network [OSTI]

    Sepke, Todd

    Noise analysis for comparator-based circuits is presented. The goal is to gain insight into the different sources of noise in these circuits for design purposes. After the general analysis techniques are established, they ...

  5. Power supply noise in delay testing 

    E-Print Network [OSTI]

    Wang, Jing

    2009-05-15

    As technology scales into the Deep Sub-Micron (DSM) regime, circuit designs have become more and more sensitive to power supply noise. Excessive noise can significantly affect the timing performance of DSM designs and cause ...

  6. Engineering to Control Noise, Loading, and Optimal Operating Points

    SciTech Connect (OSTI)

    Mitchell R. Swartz

    2000-11-12

    Successful engineering of low-energy nuclear systems requires control of noise, loading, and optimum operating point (OOP) manifolds. The latter result from the biphasic system response of low-energy nuclear reaction (LENR)/cold fusion systems, and their ash production rate, to input electrical power. Knowledge of the optimal operating point manifold can improve the reproducibility and efficacy of these systems in several ways. Improved control of noise, loading, and peak production rates is available through the study, and use, of OOP manifolds. Engineering of systems toward the OOP-manifold drive-point peak may, with inclusion of geometric factors, permit more accurate uniform determinations of the calibrated activity of these materials/systems.

  7. Quantum Noise in Conventional Optical Heterodyne Devices

    E-Print Network [OSTI]

    Dechao He; Boya Xie; Yu Xiao; Sheng Feng

    2014-10-31

    By invoking the quantum theory of optical coherence, we theoretically show that the quantum noise in conventional optical heterodyne devices, which were previously identified as usual phase-insensitive amplifiers with additional quantum noise, is similar to that in optical homodyne devices, as verified by experimental data. Albeit more study is demanded to understand this result, it is certain that neither the uncertainty principle nor Caves's theorem for quantum noise of linear amplifiers sets a limit to the quantum noise of heterodyne devices.

  8. Effects of Noise on Rodent Physiology

    E-Print Network [OSTI]

    Baldwin, Ann Linda

    2007-01-01

    content of noise in the animal house. Laboratory Animals,in laboratories and animal houses: A possible cause for

  9. How Common are Noise Sources on the Crash Arc of Malaysian Flight 370

    SciTech Connect (OSTI)

    Fenimore, Edward E.; Kunkle, Thomas David; Stead, Richard J.

    2014-10-21

    Malaysian Flight 370 disappeared nearly without a trace. Besides some communication handshakes to the INMASAT satellite, the Comprehensive Test Ban Treaty monitoring system could have heard the aircraft crash into the southern Indian Ocean. One noise event from Cape Leeuwin has been suggested by Stead as the crash and occurs within the crash location suggested by Kunkle at el. We analyze the hydrophone data from Cape Leeuwin to understand how common such noise events are on the arc of possible locations where Malaysian Flight 370 might have crashed. Few other noise sources were found on the arc. The noise event found by Stead is the strongest. No noise events are seen within the Australian Transportation Safety Board (ATSB) new search location until the 10th strongest event, an event which is very close to the noise level.

  10. Thermal and quantum noise in active systems

    E-Print Network [OSTI]

    Jean-Michel Courty; Francesca Grassia; Serge Reynaud

    2001-10-03

    We present a quantum network approach to the treatment of thermal and quantum fluctuations in measurement devices. The measurement is described as a scattering process of input fluctuations towards output ones. We present the results obtained with this method for the treatment of a cold damped capacitive accelerometer.

  11. Expectations of two-level telegraph noise

    E-Print Network [OSTI]

    Jesse Fern

    2006-11-02

    We find expectation values of functions of time integrated two-level telegraph noise. Expectation values of this noise are evaluated under simple control pulses. Both the Gaussian limit and $1/f$ noise are considered. We apply the results to a specific superconducting quantum computing example, which illustrates the use of this technique for calculating error probabilities.

  12. Noise Load Management at Amsterdam Airport Schiphol

    E-Print Network [OSTI]

    Boucherie, Richard J.

    Noise Load Management at Amsterdam Airport Schiphol T.R. Meerburg , R.J. Boucherie , M.J.A.L. van objective is to guarantee safety, efficiency, and protection of the environment, that includes noise load contributes to the noise load at these points. If the cumulative load in an aviation year at an enforce- ment

  13. Noise autocorrelation spectroscopy with coherent Raman scattering

    E-Print Network [OSTI]

    Loss, Daniel

    LETTERS Noise autocorrelation spectroscopy with coherent Raman scattering XIAOJI G. XU, STANISLAV O to noise. Here, we present a new approach to coherent Raman spectroscopy in which high resolution is achieved by means of deliberately introduced noise. The proposed method combines the efficiency

  14. Low frequency noise in superconducting qubits

    E-Print Network [OSTI]

    Fominov, Yakov

    Low frequency noise in superconducting qubits Lara Faoro and Lev Ioffe Rutgers University (USA) Exp-traps Faoro and Ioffe, PRL 96, 47001 (2006) · a discussion on the mysterious and puzzling flux noise at low... IN PROGRESS WITH EXPERIMENTALISTS! 4. Origin of low frequency flux noise at low temperature ? WHAT THE HELL

  15. Noise canceling in-situ detection

    SciTech Connect (OSTI)

    Walsh, David O.

    2014-08-26

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  16. Charge Noise in Graphene Transistors Iddo Heller,,

    E-Print Network [OSTI]

    Dekker, Cees

    Charge Noise in Graphene Transistors Iddo Heller,,§ Sohail Chatoor, Jaan Ma¨nnik, Marcel A. G an experimental study of 1/f noise in liquid-gated graphene transistors. We show that the gate dependence to the graphene, while at high carrier density it is consistent with noise due to scattering in the channel

  17. Efficient Alternatives to the Ephraim and Malah Suppression Rule for Audio Signal Enhancement

    E-Print Network [OSTI]

    2003-09-08

    –1121, 1984. [3] M. Berouti, R. Schwartz, and J. Makhoul, “Enhancement of speech corrupted by acoustic noise,” in Proc. IEEE Int. Conf. Acoustics, Speech, Signal Processing, pp. 208–211, Washington, DC, USA, April 1979. [4] R. J. McAulay andM. L. Malpass... - con, “Optimizing speech enhancement by exploiting masking Alternative Suppression Rules for Audio Signal Enhancement 1051 properties of the human ear,” in Proc. IEEE Int. Conf. Acous- tics, Speech, Signal Processing, vol. 1, pp. 800–803, Detroit, Mich...

  18. Suppression of Heating Rates in Cryogenic Surface-Electrode Ion Traps

    E-Print Network [OSTI]

    Jaroslaw Labaziewicz; Yufei Ge; Paul Antohi; David Leibrandt; Kenneth R. Brown; Isaac L. Chuang

    2007-11-16

    Dense arrays of trapped ions provide one way of scaling up ion trap quantum information processing. However, miniaturization of ion traps is currently limited by sharply increasing motional state decoherence at sub-100 um ion-electrode distances. We characterize heating rates in cryogenically cooled surface-electrode traps, with characteristic sizes in 75 um to 150 um range. Upon cooling to 6 K, the measured rates are suppressed by 7 orders of magnitude, two orders of magnitude below previously published data of similarly sized traps operated at room temperature. The observed noise depends strongly on fabrication process, which suggests further improvements are possible.

  19. Processing data base information having nonwhite noise

    DOE Patents [OSTI]

    Gross, Kenneth C. (Bolingbrook, IL); Morreale, Patricia (Park Ridge, IL)

    1995-01-01

    A method and system for processing a set of data from an industrial process and/or a sensor. The method and system can include processing data from either real or calculated data related to an industrial process variable. One of the data sets can be an artificial signal data set generated by an autoregressive moving average technique. After obtaining two data sets associated with one physical variable, a difference function data set is obtained by determining the arithmetic difference between the two pairs of data sets over time. A frequency domain transformation is made of the difference function data set to obtain Fourier modes describing a composite function data set. A residual function data set is obtained by subtracting the composite function data set from the difference function data set and the residual function data set (free of nonwhite noise) is analyzed by a statistical probability ratio test to provide a validated data base.

  20. Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise

    E-Print Network [OSTI]

    Odam, Kofi

    Performance of Photovoltaic Maximum Power Point Tracking Algorithms in the Presence of Noise tracking (MPPT) algorithms for photovoltaic systems, including how noise affects both tracking speed-performance photovoltaic sys- tems. An intelligent controller adjusts the voltage, current, or impedance seen by a solar

  1. MIMO Design of Active Noise Controllers for Car Interiors: Extending the Silenced Region at Higher Frequencies

    E-Print Network [OSTI]

    MIMO Design of Active Noise Controllers for Car Interiors: Extending the Silenced Region at Higher damping of low-frequency noise in car compartments by feedforward or feedback control. The complicated control that uses all loudspeakers of a premium car HiFi system. The results indicate that performance

  2. Is transverse feedback necessary for the SSC emittance preservation? (Vibration noise analysis and feedback parameters optimization)

    SciTech Connect (OSTI)

    Parkhomchuk, V.V.; Shiltsev, V.D.

    1993-06-01

    The paper considers the Superconducting Super Collider (SSC) site ground motion measurements as well as data from accelerators worldwide about noises that worsen beam performance. Unacceptably fast emittance growth due to these noises is predicted for the SSC. A transverse feedback system was found to be the only satisfactory alternative to prevent emittance decay. Optimization of the primary feedback parameters was done.

  3. Chaos and 1/f noise in nuclear spectra

    SciTech Connect (OSTI)

    Gomez, J. M. G.; Munoz, L.; Relano, A.; Retamosa, J. [Departamento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Faleiro, E. [Departamento de Fisica Aplicada, EUIT Industrial, Universidad Politecnica de Madrid, E-28012 Madrid (Spain); Molina, R. A. [Max-Planck-Institut fuer Physik Komplexer Systeme, D-01187 Dreden (Germany)

    2006-04-26

    Many complex systems in nature and in human society exhibit time fluctuations characterized by a power spectrum S(f) which is a power function of the frequency f. Examples with this behavior are the Sun spot activity, the human heartbeat, the DNA sequence, or Bach's First Brandenburg Concert. In this work, we show that the energy spectrum fluctuations of quantum systems can be formally considered as a discrete time series, with energy playing the role of time. Because of this analogy, the fluctuations of quantum energy spectra can be studied using traditional methods of time series, like calculating the Fourier transform and studying the power spectrum. We present the results for paradigmatic quantum chaotic systems like atomic nuclei (by means of large scale shell-model calculations) and the predictions of random matrix theory. We have found a surprising general property of quantum systems: The energy spectra of chaotic quantum systems are characterized by 1/f noise, while regular quantum systems exhibit 1/f2 noise. Some other interesting applications of this time series analogy are a test of the existence of quantum chaos remnants in the nuclear masses, and the study of the order to chaos transition in semiclassical systems. In this case, it is found that the energy level spectrum exhibits 1/f{alpha} noise with the exponent changing smoothly from {alpha} = 2 in regular systems to {alpha} = 1 in chaotic systems.

  4. Fast quantum noise in the Landau-Zener transition 

    E-Print Network [OSTI]

    Pokrovsky, Valery L.; Sun, D.

    2007-01-01

    We show by direct calculation starting from a microscopic model that the two-state system with time-dependent energy levels in the presence of fast quantum noise obeys the master equation. The solution of master equation is found analytically...

  5. Suppression of x-rays generated by runaway electrons in ATF

    SciTech Connect (OSTI)

    Rasmussen, D.A.; England, A.C.; Eberle, C.C.; Devan, W.R.; Harris, J.H.; Jernigan, T.C.; Kindsfather, R.R.; Morris, R.N.; Murakami, M.; Neilson, G.H.

    1987-01-01

    X-ray emission from runaway electrons on ATF is a serious issue. Runaway suppression techniques used on Heliotron-E are not adequate for ATF. Three approaches have been developed to suppress runaway production. Monitoring devices have been installed in occupied areas and personnel access and exposure will be limited. Additional shielding will be added as required. These systems will be ready for installation and testing on ATF prior to commissioning or first plasma operation.

  6. Low-noise pulse conditioner

    DOE Patents [OSTI]

    Bird, D.A.

    1981-06-16

    A low-noise pulse conditioner is provided for driving electronic digital processing circuitry directly from differentially induced input pulses. The circuit uses a unique differential-to-peak detector circuit to generate a dynamic reference signal proportional to the input peak voltage. The input pulses are compared with the reference signal in an input network which operates in full differential mode with only a passive input filter. This reduces the introduction of circuit-induced noise, or jitter, generated in ground referenced input elements normally used in pulse conditioning circuits, especially speed transducer processing circuits. This circuit may be used for conditioning the sensor signal from the Fidler coil in a gas centrifuge for separation of isotopic gaseous mixtures.

  7. IEEE TRANSACTIONS ON ADVANCED PACKAGING, VOL. 28, NO. 1, FEBRUARY 2005 45 Extraction of Noise Current Signatures Using

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    source developed, simultaneous switching noise in the power distribution network of the test system has the system performance. A major problem encountered in the design of complex power distribution networks is simultaneous switching noise. The power distribution system supplies power to core logic and I/O circuits

  8. Suppression of phosphate liberation from eutrophic lake sediment by using fly ash and ordinary Portland cement

    SciTech Connect (OSTI)

    Heng-Peng Ye; Fan-Zhong Chen; Yan-Qing Sheng; Guo-Ying Sheng; Jia-Mo Fu

    2006-08-15

    In this study, the effect of suppression on phosphate liberation from eutrophic lake sediment by using fly ash and ordinary Portland cement (OPC) was investigated by small scale experiment. A system including sediment, lake water, and several kinds of capping materials was designed to clarify the suppression of phosphate liberation from sediment under the anaerobic condition. The suppression efficiencies of fly ash, OPC and glass bead used as control material were also determined, and these effects were discussed. The suppression efficiency of glass bead was 44.4%, and those of fly ash and OPC were 84.4%, 94.9%, respectively. The suppression by fly ash and OPC was mainly carried out by the adsorption effect, in addition to the covering effect. The suppression efficiency depended on the amounts of the material used, and about 90% of liberated phosphate was suppressed by fly ash of 10.0 Kg m{sup -2}, and OPC of 6.0 Kg m{sup -2}. The concentrations of heavy metals, such as mercury, cadmium, lead, copper, zinc, chromium, silver, arsenic and nickel, in fly ash and OPC were lower than those in the environmental materials. And it was considered that the concentrations of heavy metals in fly ash and OPC were too low to influence the ecosystem in natural water region.

  9. LHC Beam Diffusion Dependence on RF Noise: Models And Measurements

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Van Winkle, D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; ,

    2010-09-14

    Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

  10. Data series subtraction with unknown and unmodeled background noise

    E-Print Network [OSTI]

    Stefano Vitale; Giuseppe Congedo; Rita Dolesi; Valerio Ferroni; Mauro Hueller; Daniele Vetrugno; William Joseph Weber; Heather Audley; Karsten Danzmann; Ingo Diepholz; Martin Hewitson; Natalia Korsakova; Luigi Ferraioli; Ferran Gibert; Nikolaos Karnesis; Miquel Nofrarias; Henri Inchauspe; Eric Plagnol; Oliver Jennrich; Paul W. McNamara; Michele Armano; James Ira Thorpe; Peter Wass

    2014-08-04

    LISA Pathfinder (LPF), ESA's precursor mission to a gravitational wave observatory, will measure the degree to which two test-masses can be put into free-fall, aiming to demonstrate a residual relative acceleration with a power spectral density (PSD) below 30 fm/s$^2$/Hz$^{1/2}$ around 1 mHz. In LPF data analysis, the measured relative acceleration data series must be fit to other various measured time series data. This fitting is required in different experiments, from system identification of the test mass and satellite dynamics to the subtraction of noise contributions from measured known disturbances. In all cases, the background noise, described by the PSD of the fit residuals, is expected to be coloured, requiring that we perform such fits in the frequency domain. This PSD is unknown {\\it a priori}, and a high accuracy estimate of this residual acceleration noise is an essential output of our analysis. In this paper we present a fitting method based on Bayesian parameter estimation with an unknown frequency-dependent background noise. The method uses noise marginalisation in connection with averaged Welch's periodograms to achieve unbiased parameter estimation, together with a consistent, non-parametric estimate of the residual PSD. Additionally, we find that the method is equivalent to some implementations of iteratively re-weighted least-squares fitting. We have tested the method both on simulated data of known PSD, and to analyze differential acceleration from several experiments with the LISA Pathfinder end-to-end mission simulator.

  11. Coating thermal noise for arbitrary shaped beams

    E-Print Network [OSTI]

    Richard O'Shaughnessy

    2006-10-13

    Advanced LIGO's sensitivity will be limited by coating noise. Though this noise depends on beam shape, and though nongaussian beams are being seriously considered for advanced LIGO, no published analysis exists to compare the quantitative thermal noise improvement alternate beams offer. In this paper, we derive and discuss a simple integral which completely characterizes the dependence of coating thermal noise on shape. The derivation used applies equally well, with minor modifications, to all other forms of thermal noise in the low-frequency limit.

  12. Laser phase noise effects on the dynamics of optomechanical resonators

    E-Print Network [OSTI]

    Gregory A. Phelps; Pierre Meystre

    2010-11-01

    We investigate theoretically the influence of laser phase noise on the cooling and heating of a generic cavity optomechanical system. We derive the back-action damping and heating rates and the mechanical frequency shift of the radiation pressure-driven oscillating mirror, and derive the minimum phonon occupation number for small laser linewidths. We find that in practice laser phase noise does not pose serious limitations to ground state cooling. We then consider the effects of laser phase noise in a parametric cavity driving scheme that minimizes the back-action heating of one of the quadratures of the mechanical oscillator motion. Laser linewidths narrow compared to the decay rate of the cavity field will not pose any problems in an experimental setting, but broader linewidths limit the practicality of this back-action evasion method.

  13. Superpoissonian shot noise in organic magnetic tunnel junctions

    SciTech Connect (OSTI)

    Cascales, Juan Pedro; Martinez, Isidoro; Aliev, Farkhad G.; Hong, Jhen-Yong; Lin, Minn-Tsong; Szczepa?ski, Tomasz; Dugaev, Vitalii K.; Barna?, Józef

    2014-12-08

    Organic molecules have recently revolutionized ways to create new spintronic devices. Despite intense studies, the statistics of tunneling electrons through organic barriers remains unclear. Here, we investigate conductance and shot noise in magnetic tunnel junctions with 3,4,9,10-perylene-teracarboxylic dianhydride (PTCDA) barriers a few nm thick. For junctions in the electron tunneling regime, with magnetoresistance ratios between 10% and 40%, we observe superpoissonian shot noise. The Fano factor exceeds in 1.5–2 times the maximum values reported for magnetic tunnel junctions with inorganic barriers, indicating spin dependent bunching in tunneling. We explain our main findings in terms of a model which includes tunneling through a two level (or multilevel) system, originated from interfacial bonds of the PTCDA molecules. Our results suggest that interfaces play an important role in the control of shot noise when electrons tunnel through organic barriers.

  14. KEPLER MISSION STELLAR AND INSTRUMENT NOISE PROPERTIES

    SciTech Connect (OSTI)

    Gilliland, Ronald L.; Chaplin, William J.; Elsworth, Yvonne P.; Miglio, Andrea; Dunham, Edward W.; Argabright, Vic S.; Borucki, William J.; Bryson, Stephen T.; Koch, David G.; Walkowicz, Lucianne M.; Basri, Gibor; Buzasi, Derek L.; Caldwell, Douglas A.; Jenkins, Jon M.; Van Cleve, Jeffrey; Welsh, William F.

    2011-11-01

    Kepler mission results are rapidly contributing to fundamentally new discoveries in both the exoplanet and asteroseismology fields. The data returned from Kepler are unique in terms of the number of stars observed, precision of photometry for time series observations, and the temporal extent of high duty cycle observations. As the first mission to provide extensive time series measurements on thousands of stars over months to years at a level hitherto possible only for the Sun, the results from Kepler will vastly increase our knowledge of stellar variability for quiet solar-type stars. Here, we report on the stellar noise inferred on the timescale of a few hours of most interest for detection of exoplanets via transits. By design the data from moderately bright Kepler stars are expected to have roughly comparable levels of noise intrinsic to the stars and arising from a combination of fundamental limitations such as Poisson statistics and any instrument noise. The noise levels attained by Kepler on-orbit exceed by some 50% the target levels for solar-type, quiet stars. We provide a decomposition of observed noise for an ensemble of 12th magnitude stars arising from fundamental terms (Poisson and readout noise), added noise due to the instrument and that intrinsic to the stars. The largest factor in the modestly higher than anticipated noise follows from intrinsic stellar noise. We show that using stellar parameters from galactic stellar synthesis models, and projections to stellar rotation, activity, and hence noise levels reproduce the primary intrinsic stellar noise features.

  15. Analysis of Femtosecond Timing Noise and Stability in Microwave Components

    SciTech Connect (OSTI)

    Whalen, Michael R.; /Stevens Tech. /SLAC

    2011-06-22

    To probe chemical dynamics, X-ray pump-probe experiments trigger a change in a sample with an optical laser pulse, followed by an X-ray probe. At the Linac Coherent Light Source, LCLS, timing differences between the optical pulse and x-ray probe have been observed with an accuracy as low as 50 femtoseconds. This sets a lower bound on the number of frames one can arrange over a time scale to recreate a 'movie' of the chemical reaction. The timing system is based on phase measurements from signals corresponding to the two laser pulses; these measurements are done by using a double-balanced mixer for detection. To increase the accuracy of the system, this paper studies parameters affecting phase detection systems based on mixers, such as signal input power, noise levels, temperature drift, and the effect these parameters have on components such as the mixers, splitters, amplifiers, and phase shifters. Noise data taken with a spectrum analyzer show that splitters based on ferrite cores perform with less noise than strip-line splitters. The data also shows that noise in specific mixers does not correspond with the changes in sensitivity per input power level. Temperature drift is seen to exist on a scale between 1 and 27 fs/{sup o}C for all of the components tested. Results show that any components using more metallic conductor tend to exhibit more noise as well as more temperature drift. The scale of these effects is large enough that specific care should be given when choosing components and designing the housing of high precision microwave mixing systems for use in detection systems such as the LCLS. With these improvements, the timing accuracy can be improved to lower than currently possible.

  16. Control of open quantum systems: Case study of the central spin model

    E-Print Network [OSTI]

    Christian Arenz; Giulia Gualdi; Daniel Burgarth

    2013-11-30

    We study the controllability of a central spin guided by a classical field and interacting with a spin bath, showing that the central spin is fully controllable independently of the number of bath spins. Additionally we find that for unequal system-bath couplings even the bath becomes controllable by acting on the central spin alone. We then analyze numerically how the time to implement gates on the central spin scales with the number of bath spins and conjecture that for equal system-bath couplings it reaches a saturation value. We provide evidence that sometimes noise can be effectively suppressed through control.

  17. Investigation and optimization of low-frequency noise performance in readout electronics of dc superconducting quantum interference device

    SciTech Connect (OSTI)

    Zhao, Jing; Zhang, Yi; Krause, Hans-Joachim; Lee, Yong-Ho

    2014-05-15

    We investigated and optimized the low-frequency noise characteristics of a preamplifier used for readout of direct current superconducting quantum interference devices (SQUIDs). When the SQUID output was detected directly using a room-temperature low-voltage-noise preamplifier, the low-frequency noise of a SQUID system was found to be dominated by the input current noise of the preamplifiers in case of a large dynamic resistance of the SQUID. To reduce the current noise of the preamplifier in the low-frequency range, we investigated the dependence of total preamplifier noise on the collector current and source resistance. When the collector current was decreased from 8.4 mA to 3 mA in the preamplifier made of 3 parallel SSM2220 transistor pairs, the low-frequency total voltage noise of the preamplifier (at 0.1 Hz) decreased by about 3 times for a source resistance of 30 ? whereas the white noise level remained nearly unchanged. Since the relative contribution of preamplifier's input voltage and current noise is different depending on the dynamic resistance or flux-to-voltage transfer of the SQUID, the results showed that the total noise of a SQUID system at low-frequency range can be improved significantly by optimizing the preamplifier circuit parameters, mainly the collector current in case of low-noise bipolar transistor pairs.

  18. ISCAS2000 -IEEE InternationalSymposiumon Circuitsand Systems,May 28-31, 2000, Geneva, Switzerland DESIGN AND OPTIMIZATION OF A LOW NOISE 2.4GHZ CMOS VCO

    E-Print Network [OSTI]

    Hajimiri, Ali

    DESIGN AND OPTIMIZATION OF A LOW NOISE 2.4GHZ CMOS VCO WITH INTEGRATED LC TANK AND MOSCAP TUNING Donhee calculations and computer simula- tions. It is shown that a design method for optimization of VCOs does exist voltage controlled oscillator is designed and o p timized via linear programming and implemented in a 0

  19. An SDE approximation for stochastic differential delay equations with colored state-dependent noise

    E-Print Network [OSTI]

    Austin McDaniel; Ozer Duman; Giovanni Volpe; Jan Wehr

    2014-12-09

    We consider a general multidimensional stochastic differential delay equation (SDDE) with colored state-dependent noises. We approximate it by a stochastic differential equation (SDE) system and calculate its limit as the time delays and the correlation times of the noises go to zero. The main result is proven using a theorem about convergence of stochastic integrals by Kurtz and Protter. It formalizes and extends a result that has been obtained in the analysis of a noisy electrical circuit with delayed state-dependent noise, and may be used as a working SDE approximation of an SDDE modeling a real system, where noises are correlated in time and whose response to noise sources is delayed.

  20. Noise Filtering Strategies of Adaptive Signaling Networks: The Case of E. Coli Chemotaxis

    E-Print Network [OSTI]

    Pablo Sartori; Yuhai Tu

    2011-04-20

    Two distinct mechanisms for filtering noise in an input signal are identi?ed in a class of adaptive sensory networks. We find that the high frequency noise is filtered by the output degradation process through time-averaging; while the low frequency noise is damped by adaptation through negative feedback. Both filtering processes themselves introduce intrinsic noises, which are found to be un?ltered and can thus amount to a significant internal noise floor even without signaling. These results are applied to E. coli chemotaxis. We show unambiguously that the molecular mechanism for the Berg-Purcell time-averaging scheme is the dephosphorylation of the response regulator CheY-P, not the receptor adaptation process as previously suggested. The high frequency noise due to the stochastic ligand binding-unbinding events and the random ligand molecule diffusion is averaged by the CheY-P dephosphorylation process to a negligible level in E.coli. We identify a previously unstudied noise source caused by the random motion of the cell in a ligand gradient. We show that this random walk induced signal noise has a divergent low frequency component, which is only rendered finite by the receptor adaptation process. For gradients within the E. coli sensing range, this dominant external noise can be comparable to the significant intrinsic noise in the system. The dependence of the response and its fluctuations on the key time scales of the system are studied systematically. We show that the chemotaxis pathway may have evolved to optimize gradient sensing, strong response, and noise control in di?erent time scales

  1. Influence of Gaussian white noise on the frequency-dependent first nonlinear polarizability of doped quantum dot

    SciTech Connect (OSTI)

    Ganguly, Jayanta; Ghosh, Manas

    2014-05-07

    We investigate the profiles of diagonal components of frequency-dependent first nonlinear (?{sub xxx} and ?{sub yyy}) optical response of repulsive impurity doped quantum dots. We have assumed a Gaussian function to represent the dopant impurity potential. This study primarily addresses the role of noise on the polarizability components. We have invoked Gaussian white noise consisting of additive and multiplicative characteristics (in Stratonovich sense). The doped system has been subjected to an oscillating electric field of given intensity, and the frequency-dependent first nonlinear polarizabilities are computed. The noise characteristics are manifested in an interesting way in the nonlinear polarizability components. In case of additive noise, the noise strength remains practically ineffective in influencing the optical responses. The situation completely changes with the replacement of additive noise by its multiplicative analog. The replacement enhances the nonlinear optical response dramatically and also causes their maximization at some typical value of noise strength that depends on oscillation frequency.

  2. Fighting dephasing noise with robust optimal control

    E-Print Network [OSTI]

    Young, Kevin C; Whaley, K Birgitta

    2010-01-01

    We address the experimentally relevant problem of robust mitigation of dephasing noise acting on a qubit. We first present an extension of a method for representing $1/\\omega^{\\alpha}$ noise developed by Kuopanportti et al. to the efficient representation of arbitrary Markovian noise. We then add qubit control pulses to enable the design of numerically optimized, two-dimensional control functions with bounded amplitude, that are capable of decoupling the qubit from the dephasing effects of a broad variety of Markovian noise spectral densities during arbitrary one qubit quantum operations. We illustrate the method with development of numerically optimized control pulse sequences that minimize decoherence due to a combination of $1/\\omega$ and constant offset noise sources. Comparison with the performance of standard dynamical decoupling protocols shows that the numerically optimized pulse sequences are considerably more robust with respect to the noise offset, rendering them attractive for application to situa...

  3. Flight Test of Active Gear-Mesh Noise Control on the S-76 Aircraft Thomas A. Millott William A. Welsh Charles A. Yoerkie Jr.

    E-Print Network [OSTI]

    MacMynowski, Douglas G. - MacMynowski, Douglas G.

    Flight Test of Active Gear-Mesh Noise Control on the S-76 Aircraft Thomas A. Millott William A noise comes from high frequency (>500Hz) structure- borne gear-mesh tones generated within system to actively cancel gear-mesh noise in the S-76 helicopter interior. The challenge in this ANC

  4. Noise, sampling, and the number of projections in cone-beam CT with a flat-panel detector

    SciTech Connect (OSTI)

    Zhao, Z.; Gang, G. J.; Siewerdsen, J. H.

    2014-06-15

    Purpose: To investigate the effect of the number of projection views on image noise in cone-beam CT (CBCT) with a flat-panel detector. Methods: This fairly fundamental consideration in CBCT system design and operation was addressed experimentally (using a phantom presenting a uniform medium as well as statistically motivated “clutter”) and theoretically (using a cascaded systems model describing CBCT noise) to elucidate the contributing factors of quantum noise (?{sub Q}), electronic noise (?{sub E}), and view aliasing (?{sub view}). Analysis included investigation of the noise, noise-power spectrum, and modulation transfer function as a function of the number of projections (N{sub proj}), dose (D{sub tot}), and voxel size (b{sub vox}). Results: The results reveal a nonmonotonic relationship between image noise andN{sub proj} at fixed total dose: for the CBCT system considered, noise decreased with increasing N{sub proj} due to reduction of view sampling effects in the regime N{sub proj} noise increased with N{sub proj} due to increased electronic noise. View sampling effects were shown to depend on the heterogeneity of the object in a direct analytical relationship to power-law anatomical clutter of the form ?/f?{sup ?}—and a general model of individual noise components (?{sub Q}, ?{sub E}, and ?{sub view}) demonstrated agreement with measurements over a broad range in N{sub proj}, D{sub tot}, and b{sub vox}. Conclusions: The work elucidates fairly basic elements of CBCT noise in a manner that demonstrates the role of distinct noise components (viz., quantum, electronic, and view sampling noise). For configurations fairly typical of CBCT with a flat-panel detector (FPD), the analysis reveals a “sweet spot” (i.e., minimum noise) in the rangeN{sub proj} ? 250–350, nearly an order of magnitude lower in N{sub proj} than typical of multidetector CT, owing to the relatively high electronic noise in FPDs. The analysis explicitly relates view aliasing and quantum noise in a manner that includes aspects of the object (“clutter”) and imaging chain (including nonidealities of detector blur and electronic noise) to provide a more rigorous basis for commonly held intuition and heurism in CBCT system design and operation.

  5. Teleportation in the presence of noise

    E-Print Network [OSTI]

    Ye Yeo; Zhe-Wei Kho; Lixian Wang

    2009-01-12

    Non-commuting noises may give rise to entanglement sudden death. By considering the decoherence dynamics during establishment of the channel states and noisy recovery operations, we study further the impact of non-commuting noises on single- and two-qubit teleportation. We show that in the presence of these noises there exists a critical rate of recovery operation below which teleportation will fail.

  6. Noise-assisted quantum transport and computation

    E-Print Network [OSTI]

    Diego de Falco; Dario Tamascelli

    2012-12-11

    The transmission of an excitation along a spin chain can be hindered by the presence of small fixed imperfections that create trapping regions where the excitation may get caught (Anderson localization). A certain degree of noise, ensuing from the interaction with a thermal bath, allows to overcome localization (noise-assisted transport). In this paper we investigate the relation between noise-assisted transport and (quantum) computation. In particular we prove that noise does assist classical computation on a quantum computing device but hinders the possibility of creating entanglement.

  7. Wind Turbine Acoustic Noise A white paper

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    Wind Turbine Acoustic Noise A white paper Prepared by the Renewable Energy Research Laboratory...................................................................... 8 Sound from Wind Turbines .............................................................................................. 10 Sources of Wind Turbine Sound

  8. Information and noise in quantum measurement

    E-Print Network [OSTI]

    Holger F. Hofmann

    2000-03-30

    Even though measurement results obtained in the real world are generally both noisy and continuous, quantum measurement theory tends to emphasize the ideal limit of perfect precision and quantized measurement results. In this article, a more general concept of noisy measurements is applied to investigate the role of quantum noise in the measurement process. In particular, it is shown that the effects of quantum noise can be separated from the effects of information obtained in the measurement. However, quantum noise is required to ``cover up'' negative probabilities arising as the quantum limit is approached. These negative probabilities represent fundamental quantum mechanical correlations between the measured variable and the variables affected by quantum noise.

  9. Using entanglement against noise in quantum metrology

    E-Print Network [OSTI]

    Rafal Demkowicz-Dobrzanski; Lorenzo Maccone

    2014-12-23

    We analyze the role of entanglement among probes and with external ancillas in quantum metrology. In the absence of noise, it is known that unentangled sequential strategies can achieve the same Heisenberg scaling of entangled strategies and that external ancillas are useless. This changes in the presence of noise: here we prove that entangled strategies can have higher precision than unentangled ones and that the addition of passive external ancillas can also increase the precision. We analyze some specific noise models and use the results to conjecture a general hierarchy for quantum metrology strategies in the presence of noise.

  10. ELECTROCHEMICAL NOISE BASED CORROSION MONITORING HANFORD SITE PROGRAM STATUS

    SciTech Connect (OSTI)

    EDGEMON, G.L.

    2005-03-21

    The Hanford Site near Richland, Washington has 177 underground waste tanks that store approximately 253 million liters of radioactive waste from 50 years of plutonium production. Prior to 1995 no online corrosion monitoring systems were in place at Hanford to facilitate the early detection of the onset of localized corrosion should it occur in a waste tank. Because of this, a program was started in 1995 to develop an electrochemical noise (EN) corrosion monitoring system to improve Hanford's corrosion monitoring strategy. Three systems are now installed and operating at Hanford. System design, performance history, data and the results of a recent analysis of tank vapor space data are presented.

  11. Cross-correlation measurement of quantum shot noise using homemade transimpedance amplifiers

    SciTech Connect (OSTI)

    Hashisaka, Masayuki Ota, Tomoaki; Yamagishi, Masakazu; Fujisawa, Toshimasa; Muraki, Koji

    2014-05-15

    We report a cross-correlation measurement system, based on a new approach, which can be used to measure shot noise in a mesoscopic conductor at milliKelvin temperatures. In contrast to other measurement systems in which high-speed low-noise voltage amplifiers are commonly used, our system employs homemade transimpedance amplifiers (TAs). The low input impedance of the TAs significantly reduces the crosstalk caused by unavoidable parasitic capacitance between wires. The TAs are designed to have a flat gain over a frequency band from 2 kHz to 1 MHz. Low-noise performance is attained by installing the TAs at a 4 K stage of a dilution refrigerator. Our system thus fulfills the technical requirements for cross-correlation measurements: low noise floor, high frequency band, and negligible crosstalk between two signal lines. Using our system, shot noise generated at a quantum point contact embedded in a quantum Hall system is measured. The good agreement between the obtained shot-noise data and theoretical predictions demonstrates the accuracy of the measurements.

  12. On Weak Lensing Shape Noise

    E-Print Network [OSTI]

    Niemi, Sami-Matias; Cropper, Mark

    2015-01-01

    One of the most powerful techniques to study the dark sector of the Universe is weak gravitational lensing. In practice, to infer the reduced shear, weak lensing measures galaxy shapes, which are the consequence of both the intrinsic ellipticity of the sources and of the integrated gravitational lensing effect along the line of sight. Hence, a very large number of galaxies is required in order to average over their individual properties and to isolate the weak lensing cosmic shear signal. If this `shape noise' can be reduced, significant advances in the power of a weak lensing surveys can be expected. This paper describes a general method for extracting the probability distributions of parameters from catalogues of data using Voronoi cells, which has several applications, and has synergies with Bayesian hierarchical modelling approaches. This allows us to construct a probability distribution for the variance of the intrinsic ellipticity as a function of galaxy property using only photometric data, allowing a ...

  13. Reduction of coating thermal noise by using an etalon

    E-Print Network [OSTI]

    Kentaro Somiya; Daniel Heinert; Alexey G. Gurkovsky; Stefan Hild; Ronny Nawrodt; Sergey P. Vyatchanin

    2011-01-28

    Reduction of coating thermal noise is a key issue in precise measurements with an optical interferometer. A good example of such a measurement device is a gravitational-wave detector, where each mirror is coated by a few tens of quarter-wavelength dielectric layers to achieve high reflectivity while the thermal-noise level increases with the number of layers. One way to realize the reduction of coating thermal noise, recently proposed by Khalili, is the mechanical separation of the first few layers from the rest so that a major part of the fluctuations contributes only little to the phase shift of the reflected light. Using an etalon, a Fabry-Perot optical resonator of a monolithic cavity, with a few coating layers on the front and significantly more on the back surface is a way to realize such a system without too much complexity, and in this paper we perform a thermal-noise analysis of an etalon using the Fluctuation-dissipation theorem with probes on both sides of a finite-size cylindrical mirror.

  14. Thermal noise informatics: Totally secure communication via a wire; Zero-power communication; and Thermal noise driven computing

    E-Print Network [OSTI]

    Laszlo B. Kish; Robert Mingesz; Zoltan gingl

    2007-05-30

    Very recently, it has been shown that thermal noise and its artificial versions (Johnson-like noises) can be utilized as an information carrier with peculiar properties therefore it may be proper to call this topic Thermal Noise Informatics. Zero Power (Stealth) Communication, Thermal Noise Driven Computing, and Totally Secure Classical Communication are relevant examples. In this paper, while we will briefly describe the first and the second subjects, we shall focus on the third subject, the secure classical communication via wire. This way of secure telecommunication utilizes the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The communicator is unconditionally secure at the conceptual (circuit theoretical) level and this property is (so far) unique in communication systems based on classical physics. The communicator is superior to quantum alternatives in all known aspects, except the need of using a wire. In the idealized system, the eavesdropper can extract zero bit of information without getting uncovered. The scheme is naturally protected against the man-in-the-middle attack. The communication can take place also via currently used power lines or phone (wire) lines and it is not only a point-to-point communication like quantum channels but network-ready. Tests have been carried out on a model-line with ranges beyond the ranges of any known direct quantum communication channel and they indicate unrivalled signal fidelity and security performance. This simple device has single-wire secure key generation/sharing rates of 0.1, 1, 10, and 100 bit/second for copper wires with diameters/ranges of 21 mm / 2000 km, 7 mm / 200 km, 2.3 mm / 20 km, and 0.7 mm / 2 km, respectively and it performs with 0.02% raw-bit error rate (99.98 % fidelity).

  15. Evaluation of noise associated with geothermal-development activities. Final report, July 31, 1979-April 30, 1982

    SciTech Connect (OSTI)

    Long, M.; Stern, R.

    1982-01-01

    This report was prepared for the purpose of ascertaining the current state of noise generation, suppression, and mitigation techniques associated with geothermal development. A description of the geothermal drilling process is included as well as an overview of geothermal development activities in the United States. Noise sources at the well site, along geothermal pipelines, and at the power plants are considered. All data presented are measured values by workers in the field and by Marshall Long/Acoustics. One particular well site was monitored for a period of 55 continuous days, and includes all sources of noise from the time that the drilling rig was brought in until the time that it was moved off site. A complete log of events associated with the drilling process is correlated with the noise measurements including production testing of the completed well. Data are also presented which compare measured values of geothermal noise with federal, state, county, and local standards. A section on control of geothermal noise is also given. Volume I of this document presents summary information.

  16. $1/f$ noise on the brink of wet granular melting

    E-Print Network [OSTI]

    Kai Huang

    2015-07-23

    The collective behavior of a two-dimensional wet granular cluster under horizontal swirling motions is investigated experimentally. Depending on the balance between the energy injection and dissipation, the cluster evolves into various nonequilibrium stationary states with strong internal structure fluctuations with time. Quantitative characterizations of the fluctuations with the bond orientational order parameter $q_{\\rm 6}$ reveal power spectra of the form $f^{\\alpha}$ with the exponent $\\alpha$ closely related to the stationary states of the system. In particular, $1/f$ type of noise with $\\alpha\\approx-1$ emerges as melting starts from the free surface of the cluster, suggesting the possibility of using $1/f$ noise as an indicator for phase transitions in systems driven far from thermodynamic equilibrium.

  17. Bloch-sphere approach to correlated noise in coupled qubits

    E-Print Network [OSTI]

    Hĺkon Brox; Joakim Bergli; Yuri Galperin

    2012-07-02

    By use of a generalized Bloch vector construction, we study the decoherence of a system composed of two interacting qubits in a general noisy environment. In particular, we investigate the effects of correlations in the noise acting on distinct qubits. Our treatment of the two-qubit system by use of the generalized Bloch vector leads to tractable analytic equations for the dynamics of the 4-level Bloch vector and allows for the application of geometrical concepts from the well known 2-level Bloch sphere. We find that in the presence of correlated or anticorrelated noise, the rate of decoherence is very sensitive to the initial two-qubit state, as well as to the symmetry of the Hamiltonian. In the absence of symmetry in the Hamiltonian, correlations only weakly impact the decoherence rate.

  18. Fighting dephasing noise with robust optimal control

    E-Print Network [OSTI]

    Kevin C. Young; Dylan J Gorman; K. Birgitta Whaley

    2010-05-28

    We address the experimentally relevant problem of robust mitigation of dephasing noise acting on a qubit. We first present an extension of a method for representing $1/\\omega^{\\alpha}$ noise developed by Kuopanportti et al. to the efficient representation of arbitrary Markovian noise. We then add qubit control pulses to enable the design of numerically optimized, two-dimensional control functions with bounded amplitude, that are capable of decoupling the qubit from the dephasing effects of a broad variety of Markovian noise spectral densities during arbitrary one qubit quantum operations. We illustrate the method with development of numerically optimized control pulse sequences that minimize decoherence due to a combination of $1/\\omega$ and constant offset noise sources. Comparison with the performance of standard dynamical decoupling protocols shows that the numerically optimized pulse sequences are considerably more robust with respect to the noise offset, rendering them attractive for application to situations where homogeneous dephasing noise sources are accompanied by some extent of heterogeneous dephasing. Application to the mitigation of dephasing noise on spin qubits in silicon indicates that high fidelity single qubit gates are possible with current pulse generation technology.

  19. Prediction of Jet Noise Shielding Dimitri Papamoschou*

    E-Print Network [OSTI]

    Papamoschou, Dimitri

    Prediction of Jet Noise Shielding Dimitri Papamoschou* University of California, Irvine, CA 92697, USA This study is motivated by the development of aircraft that use jet noise shielding by the airframe. Current methods to predict shielding from aircraft surfaces rely on formulae developed

  20. Suppression of Stable Flies on Cattle 

    E-Print Network [OSTI]

    Tomberlin, Jeffery K.

    2004-07-01

    : cultural, biological and chemical. Cultural control: Using cultural control methods involves manipulating the environ- ment to reduce insect pest populations. The most economical method for suppressing sta- ble fly populations is sanitation. In confined..., although parasitic wasps offer some measure of control, they do not produce immediate results, and they are not 100 per- cent effective. Therefore, do not use biological control alone but in concert with other meth- ods, such as sanitation. Chemical...

  1. Jitter, Phase Noise and Spurs in Frequency Multiplying Delay-locked loops: A Simple Model and Analysis

    E-Print Network [OSTI]

    Yang, Dihang

    2015-01-01

    ECDLL Noise Analysis . . . . . . . .discrete-time phase noiseLine (MDL) Phase Noise Model . . . . . . . . . . . . . . .

  2. Jitter, Phase Noise and Spurs in Frequency Multiplying Delay-locked loops: A Simple Model and Analysis

    E-Print Network [OSTI]

    Yang, Dihang

    2015-01-01

    noise model . . . . . . . . . . . . . . . . . . . . . . . . .Phase Noise Model . . . . . . . . . . . . . . . .ThermalPhase Noise Models . . . . . . . . . . . . . . . . the

  3. Noise in phase-preserving linear amplifiers

    SciTech Connect (OSTI)

    Pandey, Shashank; Jiang, Zhang; Combes, Joshua; Caves, Carlton M.

    2014-12-04

    The purpose of a phase-preserving linear amplifier is to make a small signal larger, so that it can be perceived by instruments incapable of resolving the original signal, while sacrificing as little as possible in signal-to-noise. Quantum mechanics limits how well this can be done: the noise added by the amplifier, referred to the input, must be at least half a quantum at the operating frequency. This well-known quantum limit only constrains the second moments of the added noise. Here we provide the quantum constraints on the entire distribution of added noise: any phasepreserving linear amplifier is equivalent to a parametric amplifier with a physical state ? for the ancillary mode; ? determines the properties of the added noise.

  4. Characterizing the acoustic noise generated by hard disk drives and a scheme for detecting noisy hard drives 

    E-Print Network [OSTI]

    Kim, Seuk Bo

    1992-01-01

    to nearly all personal computer systems, and has been identified as one of the more noisy elements in the system. " The research limited its scope on pattern recognition and characteristic feature selection of noise signals for hard disl& drives...

  5. Compensation of decoherence from telegraph noise by means of bang-bang control

    E-Print Network [OSTI]

    H. Gutmann; F. K. Wilhelm; W. M. Kaminsky; S. Lloyd

    2003-09-17

    With the growing efforts in isolating solid-state qubits from external decoherence sources, the origins of noise inherent to the material start to play a relevant role. One representative example are charged impurities in the device material or substrate, which typically produce telegraph noise and can hence be modelled as bistable fluctuators. In order to demonstrate the possibility of the active suppression of the disturbance from a {\\em single} fluctuator, we theoretically implement an elementary bang-bang control protocol. We numerically simulate the random walk of the qubit state on the Bloch sphere with and without bang-bang compensation by means of the stochastic Schr\\"odinger equation and compare it with an analytical saddle point solution of the corresponding Langevin equation in the long-time limit. We find that the deviation with respect to the noiseless case is significantly reduced when bang-bang pulses are applied, being scaled down approximately by the ratio of the bang-bang period and the typical flipping time of the bistable fluctuation. Our analysis gives not only the effect of bang-bang control on the variance of these deviations, but also their entire distribution. As a result, we expect that bang-bang control works as a high-pass filter on the spectrum of noise sources. This indicates how the influence of $1/f$-noise ubiquitous to the solid state world can be reduced.

  6. Phase transitions in the majority-vote model with two types of noises

    E-Print Network [OSTI]

    Vieira, Allan R

    2015-01-01

    In this work we study the majority-vote model with the presence of two distinc noises. The first one is the usual noise $q$, that represents the probability that a given agent follows the minority opinion of his/her social contacts. On the other hand, we consider the independent behavior, such that an agent can choose his/her own opinion $+1$ or $-1$ with equal probability, independent of the group's norm. We study the impact of the presence of such two kinds of stochastic driving in the phase transitions of the model, considering the mean field and the square lattice cases. Our results suggest that the model undergoes a nonequilibrium order-disorder phase transition even in the absence of the noise $q$, due to the independent behavior, but this transition may be suppressed. In addition, for both topologies analyzed, we verified that the transition is in the same universality class of the equilibrium Ising model, i.e., the critical exponents are not affected by the presence of the second noise, associated wit...

  7. Quantum Brownian motion induced by thermal noise in the presence of disorder

    E-Print Network [OSTI]

    Jürg Fröhlich; Jeffrey Schenker

    2015-06-05

    The motion of a quantum particle hopping on a simple cubic lattice under the influence of thermal noise and of a static random potential is expected to be diffusive, i.e., the particle is expected to exhibit `quantum Brownian motion', no matter how weak the thermal noise is. This is shown to be true in a model where the dynamics of the particle is governed by a Lindblad equation for a one-particle density matrix. The generator appearing in this equation is the sum of two terms: a Liouvillian corresponding to a random Schr\\"odinger operator and a Lindbladian describing the effect of thermal noise in the kinetic limit. Under suitable but rather general assumptions on the Lindbladian, the diffusion constant characterizing the asymptotics of the motion of the particle is proven to be strictly positive and finite. If the disorder in the random potential is so large that transport is completely suppressed in the limit where the thermal noise is turned off, then the diffusion constant tends to $0$ proportional to the coupling of the particle to the heat bath.

  8. Active Vibration Suppression of Sandwich Beams using Piezoelectric Shear Actuators

    E-Print Network [OSTI]

    Vel, Senthil

    on the effectiveness of the piezo- electric shear mechanism for active vibration suppression. In this paper, weActive Vibration Suppression of Sandwich Beams using Piezoelectric Shear Actuators Senthil S. Vel1 of the piezoelectric actuators to cause transverse shear deformation of the sandwich beam. Active vibration suppression

  9. Effects of finite sampling and additive noise on image reconstruction from Radon transform

    SciTech Connect (OSTI)

    Tsujimoto, E.M. (California Univ., Davis, CA (USA))

    1988-12-01

    The Radon transform arises naturally in the problem of reconstructing an image or cross section from line integral measurements through a specified object. Each line integral or ray is a sample of the Radon transform of the object and the set of all samples at a particular angle is called a projection or view. Consequently, the set of all possible samples at all possible projections in a particular plane constitutes the two-dimensional Radon transform. Of course, it is impossible to acquire an infinite number of data points for the purpose of image reconstruction. However, with a sufficient set of Radon transform samples, an images can be determined through various Radon transform inversion techniques. From this statement, however, arises the question of just what constitutes a sufficient set of Radon transform samples. Acquiring an insufficient number of samples results in various artifacts in the reconstructed image. On the other hand, taking too many samples utilizes the data inefficiently. Thus, the problem of interest is to determine the optimum number of projections and the optimum number of samples per projection required to adequately represent the Radon transform such that the image can be accurately reconstructed. The problem of image reconstruction is further complicated if noise is introduced in the projection domain. Noise may be caused by round-off error in the sampled projection data or by various other factors inherent in data acquisition processes. However, several filtering techniques can be implemented to suppress the effects of noise. Therefore, a second problem of interest is to study the effectiveness of different filtering techniques in noise suppression.

  10. Rotating-frame relaxation as a noise spectrum analyzer of a superconducting qubit undergoing driven evolution

    E-Print Network [OSTI]

    F. Yan; S. Gustavsson; J. Bylander; X. Jin; F. Yoshihara; D. G. Cory; Y. Nakamura; T. P. Orlando; W. D. Oliver

    2015-08-26

    Gate operations in a quantum information processor are generally realized by tailoring specific periods of free and driven evolution of a quantum system. Unwanted environmental noise, which may in principle be distinct during these two periods, acts to decohere the system and increase the gate error rate. While there has been significant progress characterizing noise processes during free evolution, the corresponding driven-evolution case is more challenging as the noise being probed is also extant during the characterization protocol. Here we demonstrate the noise spectroscopy (0.1 - 200 MHz) of a superconducting flux qubit during driven evolution by using a robust spin-locking pulse sequence to measure relaxation (T1rho) in the rotating frame. In the case of flux noise, we resolve spectral features due to coherent fluctuators, and further identify a signature of the 1MHz defect in a time-domain spin-echo experiment. The driven-evolution noise spectroscopy complements free-evolution methods, enabling the means to characterize and distinguish various noise processes relevant for universal quantum control.

  11. Linear response of tripartite entanglement to infinitesimal noise

    SciTech Connect (OSTI)

    Zhang, Fu-Lin; Chen, Jing-Ling

    2014-10-15

    Recent experimental progress in prolonging the coherence time of a quantum system prompts us to explore the behavior of quantum entanglement at the beginning of the decoherence process. The response of the entanglement under an infinitesimal noise can serve as a signature of the robustness of entangled states. A crucial problem of this topic in multipartite systems is to compute the degree of entanglement in a mixed state. We find a family of global noise in three-qubit systems, which is composed of four W states. Under its influence, the linear response of the tripartite entanglement of a symmetrical three-qubit pure state is studied. A lower bound of the linear response is found to depend completely on the initial tripartite and bipartite entanglement. This result shows that the decay of tripartite entanglement is hastened by the bipartite one. - Highlights: • We study a set of W-type noise and its linear effect on symmetric pure states. • Its effect on two-qubit entanglement depends only on the initial concurrence. • A lower bound of the effect on 3-tangle is found in terms of initial entanglements. • We obtain the time of three-tangle sudden death for two families of typical states. • These reveal that the bipartite entanglement speeds up the decay of the tripartite one.

  12. Leading the way in aircraft noise reduction Aircraft noise threatens the growth of the important UK aerospace manufacturing sector.

    E-Print Network [OSTI]

    Sóbester, András

    of Computational Aero-acoustics, Phil Joseph, Professor of acoustical engineering and turbo-machinery noise and Dr method for reducing fan noise, the largest single source of engine noise both at take-off and approachLeading the way in aircraft noise reduction Aircraft noise threatens the growth of the important UK

  13. Noise and meaning : a cognitive ethnography of San Diego musicians

    E-Print Network [OSTI]

    Davis, Clinton Ross

    2011-01-01

    Splinter in Your Ear: Noise as the Semblance of Critique."OF CALIFORNIA, SAN DIEGO Noise and Meaning: A CognitiveI. A General Overview of Noise and Experimental Musicians in

  14. Radio Frequency Noise Effects on the CERN Large Hadron Collider Beam Diffusion

    SciTech Connect (OSTI)

    Mastoridis, T.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; Rivetta, C.; Fox, J.D.; /SLAC

    2012-04-30

    Radio frequency (rf) accelerating system noise can have a detrimental impact on the Large Hadron Collider (LHC) performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and rf station dynamics with the bunch length growth. Measurements were conducted at LHC to determine the performance limiting rf components and validate the formalism through studies of the beam diffusion dependence on rf noise. As a result, a noise threshold was established for acceptable performance which provides the foundation for beam diffusion estimates for higher energies and intensities. Measurements were also conducted to determine the low level rf noise spectrum and its major contributions, as well as to validate models and simulations of this system.

  15. Ultrasensitive measurement of MEMS cantilever displacement sensitivity below the shot noise limit

    E-Print Network [OSTI]

    R. C. Pooser; B. J. Lawrie

    2015-06-29

    The displacement of micro-electro-mechanical-systems (MEMS) cantilevers is used to measure a broad variety of phenomena in devices ranging from force microscopes to biochemical sensors to thermal imaging systems. We demonstrate the first direct measurement of a MEMS cantilever displacement with a noise floor at 40% of the shot noise limit (SNL). By combining multi-spatial-mode quantum light sources with a simple ?differential measurement, we show that sub-SNL MEMS displacement sensitivity is highly accessible compared to previous efforts that measured the displacement of macroscopic mirrors with very distinct spatial structures crafted with multiple optical parametric amplifiers and locking loops. These results support a new class of quantum MEMS sensor with an ultimate signal to noise ratio determined by quantum correlations, enabling ultra-trace sensing, imaging, and microscopy applications in which signals were previously obscured by shot noise.

  16. Noise-based communication and computing

    E-Print Network [OSTI]

    Laszlo B. Kish

    2008-08-19

    We discuss the speed-error-heat triangle and related problems with rapidly increasing energy dissipation and error rate during miniaturization. These and the independently growing need of unconditional data security have provoked non-conventional approaches in the physics of informatics. Noise-based informatics is a potentially promising possibility which is the way how biological brains process the information. Recently, it has been shown that thermal noise and its electronically enhanced versions (Johnson-like noises) can be utilized as information carrier with peculiar properties. Relevant examples are Zero power (stealth) communication, Unconditionally secure communication with Johnson(-like) noise and Kirchhoff loop and Noise-driven computing. The zero power communication utilizes the equilibrium background noise in the channel to transfer information. The unconditionally secure communication is based on the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The scheme utilizes on the robustness of classical information and the second law of thermodynamics. It uncovers active eavesdropping within a single clock period (no error statistics is required) and it is naturally protected against the man-in-the-middle attack. Further advantages of the scheme is that the circuitry can easily be integrated on computer chips, unconditionally secure computer processors, memories and other hardware can be realized.

  17. Electrical flicker-noise generated by filling and emptying of impurity states in injectors of quantum-cascade lasers

    SciTech Connect (OSTI)

    Yamanishi, Masamichi Hirohata, Tooru; Hayashi, Syohei; Fujita, Kazuue; Tanaka, Kazunori

    2014-11-14

    Free running line-widths (>100?kHz), much broader than intrinsic line-widths ?100?Hz, of existing quantum-cascade lasers are governed by strong flicker frequency-noise originating from electrical flicker noise. Understanding of microscopic origins of the electrical flicker noises in quantum-cascade lasers is crucially important for the reduction of strength of flicker frequency-noise without assistances of any type of feedback schemes. In this article, an ad hoc model that is based on fluctuating charge-dipoles induced by electron trappings and de-trappings at indispensable impurity states in injector super-lattices of a quantum-cascade laser is proposed, developing theoretical framework based on the model. The validity of the present model is evaluated by comparing theoretical voltage-noise power spectral densities based on the model with experimental ones obtained by using mid-infrared quantum-cascade lasers with designed impurity-positioning. The obtained experimental results on flicker noises, in comparison with the theoretical ones, shed light on physical mechanisms, such as the inherent one due to impurity states in their injectors and extrinsic ones due to surface states on the ridge-walls and due to residual deep traps, for electrical flicker-noise generation in existing mid-infrared quantum-cascade lasers. It is shown theoretically that quasi-delta doping of impurities in their injectors leads to strong suppression of electrical flicker noise by minimization of the dipole length at a certain temperature, for instance ?300?K and, in turn, is expected to result in substantial narrowing of the free running line-width down below 10?kHz.

  18. Integration of Noise and Coda Correlation Data into Kinematic...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    This project will focus on using microearthquakes (MEQ) and noise correlation Green's functions (NCF) obtained from MEQs and ambient noise and coda-wave interferometry to image the...

  19. On noise induced Poincaré-Andronov-Hopf bifurcation (Journal...

    Office of Scientific and Technical Information (OSTI)

    the well known stochastic resonance in the sense that it effectively converts noise into useful energy. Herein, we clearly explain how noise induced imperfection in the...

  20. Recurrent neural network language model training with noise contrastive estimation for speech recognition

    E-Print Network [OSTI]

    Chen, X.; Liu, X.; Gales, M. J. F.; Woodland, P. C.

    2015-04-22

    , recurrent neural network, GPU, noise contrastive estimation, speech recognition 1. INTRODUCTION Statistical language models (LMs) are crucial components in many speech and language processing systems designed for tasks such as speech recognition, spoken... as follows. In section 2, recur- rent neural network LMs are reviewed. Noise contrastive estimation is presented in section 3. The detailed implement of NCE training is presented in section 4. Experiment results on a large vocabulary conversational telephone...

  1. A study of semiconductor laser noise and its effect on fiber optic sensor performance 

    E-Print Network [OSTI]

    Lee, Wanku

    1994-01-01

    Diodes B. Coherence of Light Sources and FFPI Sensor III EXPERIMENTAL PROCEDURES AND RESULTS A, Experimental Procedures B. Experimental Results IV CONCLUSION V RECOMMENDATIONS A. Preparation of Half-Formed FFPI Sensors B. Measurement of Optical... laser light sources. Sensor performance has always been limited by the intrinsic noise of laser diode. This noise degrades the performance of interferometric fiber-optic sensor systems including those which employ fiber-optic Fabry-Perot sensors...

  2. The promoters of human cell cycle genes integrate signals from two tumor suppressive pathways during

    E-Print Network [OSTI]

    Domany, Eytan

    The promoters of human cell cycle genes integrate signals from two tumor suppressive pathways.9.05 Deciphering regulatory events that drive malignant transformation represents a major challenge for systemsINK4A tumor suppressors inactivation. This cluster predominantly consists of cell cycle genes

  3. PROPER FILTER DESIGN PROCEDURE FOR VIBRATION SUPPRESSION USING DELAY-ERROR-ORDER CURVES

    E-Print Network [OSTI]

    Mavroidis, Constantinos

    PROPER FILTER DESIGN PROCEDURE FOR VIBRATION SUPPRESSION USING DELAY-ERROR-ORDER CURVES D. Economou of Mechanical Engineering, Mechanical Design and Control Systems Division, 9 Heroon Polytechniou Str., 15773@central.ntua.gr B Rutgers University, The State University of New Jersey, Department of Mechanical and Aerospace

  4. Localization of quantum Bernoulli noises

    SciTech Connect (OSTI)

    Wang, Caishi; Zhang, Jihong [School of Mathematics and Statistics, Northwest Normal University, Lanzhou, Gansu 730070 (China)] [School of Mathematics and Statistics, Northwest Normal University, Lanzhou, Gansu 730070 (China)

    2013-10-15

    The family (?{sub k},?{sub k}{sup *}){sub k?0} of annihilation and creation operators acting on square integrable functionals of a Bernoulli process Z= (Z{sub k}){sub k?0} can be interpreted as quantum Bernoulli noises. In this note we consider the operator family (?{sub k},?{sub k}{sup *}){sub k?0}, where ?{sub k}=?{sub k}E{sub k} with E{sub k} being the conditional expectation (operator) given ?-field ?(Z{sub j}; 0 ?j?k). We show that ?{sub k} (resp. ?{sub k}{sup *}) is essentially a kind of localization of the annihilation operator ?{sub k} (resp. creation operator ?{sub k}{sup *}). We examine properties of the family (?{sub k},?{sub k}{sup *}){sub k?0} and prove, among other things, that ?{sub k} and ?{sub k}{sup *} satisfy a local canonical anti-communication relation and (?{sub k}{sup *}){sub k?0} forms a mutually orthogonal operator sequence although each ?{sub k} is not a projection operator. We find that the operator series ?{sub k=0}{sup ?}?{sub k}{sup *}X?{sub k} converges in the strong operator topology for each bounded operator X acting on square integrable functionals of Z. In particular we get an explicit sum of the operator series ?{sub k=0}{sup ?}?{sub k}{sup *}?{sub k}. A useful norm estimate on ?{sub k=0}{sup ?}?{sub k}{sup *}X?{sub k} is also obtained. Finally we show applications of our main results to quantum dynamical semigroups and quantum probability.

  5. Regression of Environmental Noise in LIGO Data

    E-Print Network [OSTI]

    Tiwari, Vaibhav; Frolov, Valery; Klimenko, Sergey; Mitselmakher, Guenakh; Necula, Valentin; Prodi, Giovanni; Re, Virginia; Salemi, Francesco; Vedovato, Gabriele; Yakushin, Igor

    2015-01-01

    We address the problem of noise regression in the output of gravitational-wave (GW) interferometers, using data from the physical environmental monitors (PEM). The objective of the regression analysis is to predict environmental noise in the gravitational-wave channel from the PEM measurements. One of the most promising regression method is based on the construction of Wiener-Kolmogorov filters. Using this method, the seismic noise cancellation from the LIGO GW channel has already been performed. In the presented approach the Wiener-Kolmogorov method has been extended, incorporating banks of Wiener filters in the time-frequency domain, multi-channel analysis and regulation schemes, which greatly enhance the versatility of the regression analysis. Also we presents the first results on regression of the bi-coherent noise in the LIGO data.

  6. Multimaterial coatings with reduced thermal noise

    E-Print Network [OSTI]

    Yam, William

    The most sensitive measurements of time and space are made with resonant optical cavities, and these measurements are limited by coating thermal noise. The mechanical and optical performance requirements placed on coating ...

  7. Thermal noise for quantum state inference

    E-Print Network [OSTI]

    D. Mogilevtsev; V. S. Shchesnovich; N. Korolkova

    2013-02-15

    In this work we describe a simple and efficient scheme for inference of photon number distribution by adding variable thermal noise to the signal. The inference remains feasible even if the scheme parameters are subject to random dynamical change.

  8. Thermal-noise-limited underground interferometer CLIO

    E-Print Network [OSTI]

    Kazuhiro Agatsuma; Koji Arai; Masa-Katsu Fujimoto; Seiji Kawamura; Kazuaki Kuroda; Osamu Miyakawa; Shinji Miyoki; Masatake Ohashi; Toshikazu Suzuki; Ryutaro Takahashi; Daisuke Tatsumi; Souichi Telada; Takashi Uchiyama; Kazuhiro Yamamoto; CLIO collaborators

    2010-01-29

    We report on the current status of CLIO (Cryogenic Laser Interferometer Observatory), which is a prototype interferometer for LCGT (Large Scale Cryogenic Gravitational-Wave Telescope). LCGT is a Japanese next-generation interferometric gravitational wave detector featuring the use of cryogenic mirrors and a quiet underground site. The main purpose of CLIO is to demonstrate a reduction of the mirror thermal noise by cooling the sapphire mirrors. CLIO is located in an underground site of the Kamioka mine, 1000 m deep from the mountain top, to verify its advantages. After a few years of commissioning work, we have achieved a thermal-noise-limited sensitivity at room temperature. One of the main results of noise hunting was the elimination of thermal noise caused by a conductive coil-holder coupled with a pendulum through magnets.

  9. Analog Noise Reduction in Enzymatic Logic Gates

    E-Print Network [OSTI]

    Dmitriy Melnikov; Guinevere Strack; Marcos Pita; Vladimir Privman; Evgeny Katz

    2009-05-17

    In this work we demonstrate both experimentally and theoretically that the analog noise generation by a single enzymatic logic gate can be dramatically reduced to yield gate operation with virtually no input noise amplification. This is achieved by exploiting the enzyme's specificity when using a co-substrate that has a much lower affinity than the primary substrate. Under these conditions, we obtain a negligible increase in the noise output from the logic gate as compared to the input noise level. Experimental realizations of the AND logic gate with the enzyme horseradish peroxidase using hydrogen peroxide and two different co-substrates, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and ferrocyanide, with vastly different rate constants confirmed our general theoretical conclusions.

  10. Spectral analysis of vibratory gyro noise

    E-Print Network [OSTI]

    Kim, D; M'Closkey, RT

    2013-01-01

    thermal noise in mems gyroscopes,” IEEE Sensors J. , vol. 5,mems gyroscope with unconstrained sigma-delta force-feedback,” IEEE SensorsMEMS vibratory gyro shows excellent agreement with the model predictions for a variety of sensor

  11. Regression of Environmental Noise in LIGO Data

    E-Print Network [OSTI]

    Vaibhav Tiwari; Marco Drago; Valery Frolov; Sergey Klimenko; Guenakh Mitselmakher; Valentin Necula; Giovanni Prodi; Virginia Re; Francesco Salemi; Gabriele Vedovato; Igor Yakushin

    2015-03-25

    We address the problem of noise regression in the output of gravitational-wave (GW) interferometers, using data from the physical environmental monitors (PEM). The objective of the regression analysis is to predict environmental noise in the gravitational-wave channel from the PEM measurements. One of the most promising regression method is based on the construction of Wiener-Kolmogorov filters. Using this method, the seismic noise cancellation from the LIGO GW channel has already been performed. In the presented approach the Wiener-Kolmogorov method has been extended, incorporating banks of Wiener filters in the time-frequency domain, multi-channel analysis and regulation schemes, which greatly enhance the versatility of the regression analysis. Also we presents the first results on regression of the bi-coherent noise in the LIGO data.

  12. Estimating atmospheric parameters and reducing noise for multispectral imaging

    DOE Patents [OSTI]

    Conger, James Lynn

    2014-02-25

    A method and system for estimating atmospheric radiance and transmittance. An atmospheric estimation system is divided into a first phase and a second phase. The first phase inputs an observed multispectral image and an initial estimate of the atmospheric radiance and transmittance for each spectral band and calculates the atmospheric radiance and transmittance for each spectral band, which can be used to generate a "corrected" multispectral image that is an estimate of the surface multispectral image. The second phase inputs the observed multispectral image and the surface multispectral image that was generated by the first phase and removes noise from the surface multispectral image by smoothing out change in average deviations of temperatures.

  13. Effect of noise on the standard mapping

    SciTech Connect (OSTI)

    Karney, C.F.F.; Rechester, A.B.; White, R.B.

    1981-03-01

    The effect of a small amount of noise on the standard mapping is considered. Whenever the standard mapping possesses accelerator models (where the action increases approximately linearly with time), the diffusion coefficient contains a term proportional to the reciprocal of the variance of the noise term. At large values of the stochasticity parameter, the accelerator modes exhibit a universal behavior. As a result the dependence of the diffusion coefficient on stochasticity parameter also shows some universal behavior.

  14. Entanglement, noise, and the cumulant expansion

    E-Print Network [OSTI]

    Joaquín E. Drut; William J. Porter

    2015-08-19

    We put forward a variation of a recently proposed method to overcome the signal-to-noise problem found in Monte Carlo calculations of the entanglement entropy of interacting fermions. The present method takes advantage of the approximate lognormal distributions that characterize the signal-to-noise properties of other approaches. We test our technique by implementing it in combination with the hybrid Monte Carlo algorithm and calculating the second R\\'enyi entanglement entropy of the 1D Hubbard model.

  15. Effects of Tidal Turbine Noise on Fish Task 2.1.3.2: Effects on Aquatic Organisms: Acoustics/Noise - Fiscal Year 2011 - Progress Report - Environmental Effects of Marine and Hydrokinetic Energy

    SciTech Connect (OSTI)

    Halvorsen, Michele B.; Carlson, Thomas J.; Copping, Andrea E.

    2011-09-30

    Naturally spawning stocks of Chinook salmon (Oncorhynchus tshawytscha) that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/ Chinook/CKPUG.cfm). Plans exist for prototype tidal turbines to be deployed into their habitat. Noise is known to affect fish in many ways, such as causing a threshold shift in auditory sensitivity or tissue damage. The characteristics of noise, its spectra and level, are important factors that influence the potential for the noise to injure fish. For example, the frequency range of the tidal turbine noise includes the audiogram (frequency range of hearing) of most fish. This study (Effects on Aquatic Organisms, Subtask 2.1.3.2: Acoustics) was performed during FY 2011 to determine if noise generated by a 6-m-diameter open-hydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. After they were exposed to simulated tidal turbine noise, the hearing of juvenile Chinook salmon was measured and necropsies performed to check for tissue damage. Experimental groups were (1) noise exposed, (2) control (the same handling as treatment fish but without exposure to tidal turbine noise), and (3) baseline (never handled). Preliminary results indicate that low levels of tissue damage may have occurred but that there were no effects of noise exposure on the auditory systems of the test fish.

  16. Chaos suppression in gas-solid fluidization

    SciTech Connect (OSTI)

    Pence, D.V.; Beasley, D.E.

    1997-07-01

    The present study examines the effect of an opposing oscillatory flow on local, instantaneous heat transfer and pressure in a laboratory scale gas-fluidized bed. The experimental facility models a Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed. Time-varying data were acquired at eight angular positions around a horizontal cylinder submerged in a monodisperse distribution of particles having a weight mean diameter of 345 {micro}m. Total flow rates employed in the present study ranged from 10 to 40% greater than the flow required for minimum fluidization. Spectral analyses of local, instantaneous heat flux and pressure clearly indicate that the bed hydrodynamics were significantly altered by the opposing secondary flow. The behavior of time-varying local pressure and heat transfer in fluidized beds in the absence of a secondary flow is consistent with deterministic chaos. Kolmogorov entropy estimates from local, instantaneous pressure suggest that the degree of chaotic behavior was substantially suppressed for operating conditions with low primary and secondary flow rates, and a secondary flow forcing frequency of 15 Hz. In contrast, entropy estimates from measurements of local, instantaneous heat transfer suggest no clear indication of chaos suppression for these operating conditions.

  17. Quantum bath-driven decoherence of mixed spin systems

    E-Print Network [OSTI]

    S. J. Balian; Gary Wolfowicz; John J. L. Morton; T. S. Monteiro

    2013-11-22

    The decoherence of mixed electron-nuclear spin qubits is a topic of great current importance, but understanding is still lacking: while important decoherence mechanisms for spin qubits arise from quantum spin bath environments with slow decay of correlations, the only analytical framework for explaining observed sharp variations of decoherence times with magnetic field is based on the suppression of classical noise. Here we obtain a general expression for decoherence times of the central spin system which exposes significant differences between quantum-bath decoherence and decoherence by classical field noise. We perform measurements of decoherence times of bismuth donors in natural silicon using both electron spin resonance (ESR) and nuclear magnetic resonance (NMR) transitions, and in both cases find excellent agreement with our theory across a wide parameter range. The universality of our expression is also tested by quantitative comparisons with previous measurements of decoherence around `optimal working points' or `clock transitions' where decoherence is strongly suppressed. We further validate our results by comparison to cluster expansion simulations.

  18. Cross-talk free, low-noise optical amplifier

    DOE Patents [OSTI]

    Dijaili, Sol P. (Moraga, CA); Patterson, Frank G. (Livermore, CA); Deri, Robert J. (Pleasanton, CA)

    1995-01-01

    A low-noise optical amplifier solves crosstalk problems in optical amplifiers by using an optical cavity oriented off-axis (e.g. perpendicular) to the direction of a signal amplified by the gain medium of the optical amplifier. Several devices are used to suppress parasitic lasing of these types of structures. The parasitic lasing causes the gain of these structures to be practically unusable. The lasing cavity is operated above threshold and the gain of the laser is clamped to overcome the losses of the cavity. Any increase in pumping causes the lasing power to increase. The clamping action of the gain greatly reduces crosstalk due to gain saturation for the amplified signal beam. It also reduces other nonlinearities associated with the gain medium such as four-wave mixing induced crosstalk. This clamping action can occur for a bandwidth defined by the speed of the laser cavity. The lasing field also reduces the response time of the gain medium. By having the lasing field off-axis, no special coatings are needed. Other advantages are that the lasing field is easily separated from the amplified signal and the carrier grating fluctuations induced by four-wave mixing are decreased. Two related methods reduce the amplified spontaneous emission power without sacrificing the gain of the optical amplifier.

  19. Noise, sign problems, and statistics

    E-Print Network [OSTI]

    Michael G. Endres; David B. Kaplan; Jong-Wan Lee; Amy N. Nicholson

    2011-06-01

    We show how sign problems in simulations of many-body systems can manifest themselves in the form of heavy-tailed correlator distributions, similar to what is seen in electron propagation through disordered media. We propose an alternative statistical approach for extracting ground state energies in such systems, illustrating the method with a toy model and with lattice data for unitary fermions.

  20. Shot noise in an electron waveguide square root of NOT gate

    E-Print Network [OSTI]

    Linda E. Reichl; Michael G. Snyder

    2006-01-17

    We present a calculation of the shot noise in a ballistic electron waveguide square root of NOT gate. A general expression for the shot noise in the leads connected to these types of gates is shown. We then parameterize an S-matrix which qualitatively describes the action of a square root of NOT gate previously found through numerical methods for GaAs/Al_xGa_{1-x}As based waveguides systems. Using this S-matrix, the shot noise in a single output lead and across two output leads is calculated. We find that the measurement of the shot noise across two output leads allows for the determination of the fidelity of the gate itself.

  1. Modeling Barkhausen Noise in Magnetic Glasses with Dipole-Dipole Interactions

    E-Print Network [OSTI]

    Awadhesh K. Dubey; H. George E. Hentschel; Prabhat K. Jaiswal; Chandana Mondal; Itamar Procaccia; Bhaskar Sen Gupta

    2015-06-07

    Long-ranged dipole-dipole interactions in magnetic glasses give rise to magnetic domains having labyrinthine patterns. Barkhausen Noise is then expected to result from the movement of domain boundaries which is supposed to be modeled by the motion of elastic membranes with random pinning. We propose an atomistic model of such magnetic glasses in which we measure the Barkhausen Noise which indeed results from the movement of domain boundaries. Nevertheless the statistics of the Barkhausen Noise is found in striking disagreement with the expectations in the literature. In fact we find exponential statistics without any power law, stressing the fact that Barkhausen Noise can belong to very different universality classes. In this glassy system the essence of the phenomenon is the ability of spin-carrying particles to move and minimize the energy without any spin flip. A theory is offered in excellent agreement with the measured data without any free parameter.

  2. Quantum-projection-noise-limited interferometry with coherent atoms in a Ramsey-type setup

    SciTech Connect (OSTI)

    Doering, D.; McDonald, G.; Debs, J. E.; Figl, C.; Altin, P. A.; Bachor, H.-A.; Robins, N. P.; Close, J. D. [Australian Research Council Centre of Excellence for Quantum-Atom Optics, Australian National University, Canberra, 0200 (Australia); Department of Quantum Science, Research School of Physics and Engineering, Australian National University, Canberra, 0200 (Australia)

    2010-04-15

    Every measurement of the population in an uncorrelated ensemble of two-level systems is limited by what is known as the quantum projection noise limit. Here, we present quantum-projection-noise-limited performance of a Ramsey-type interferometer using freely propagating coherent atoms. The experimental setup is based on an electro-optic modulator in an inherently stable Sagnac interferometer, optically coupling the two interfering atomic states via a two-photon Raman transition. Going beyond the quantum projection noise limit requires the use of reduced quantum uncertainty (squeezed) states. The experiment described demonstrates atom interferometry at the fundamental noise level and allows the observation of possible squeezing effects in an atom laser, potentially leading to improved sensitivity in atom interferometers.

  3. Innovated Higher Criticism for Detecting Sparse Signals in Correlated Noise

    E-Print Network [OSTI]

    Jin, Jiashun

    - though first proposed in cases where the noise variables are independent, Higher Criti- cism also has

  4. Noise Analysis and Synthesis for 3D Laser Depth Scanners

    E-Print Network [OSTI]

    Martin, Ralph R.

    Noise Analysis and Synthesis for 3D Laser Depth Scanners Xianfang Sun a,b,, Paul L. Rosin a , Ralph the noise present in range data measured by a Konica Minolta Vivid 910 scanner, in order to better characterise real scanner noise. Methods for denoising 3D mesh data have often assumed the noise to be Gaussian

  5. Improved Crosstalk Modeling with Applications to Noise Constrained Interconnect Optimization

    E-Print Network [OSTI]

    Pan, David Z.

    Improved Crosstalk Modeling with Applications to Noise Constrained Interconnect Optimization This paper presents a highly accurate yet efficient crosstalk noise model, the 2-˘ model, and applies to be noise immune, ac- curate yet efficient noise models are needed to guide interconnect optimizations

  6. Realistic Simulation of Jet Engine Noise using Petaflop Computing

    E-Print Network [OSTI]

    Realistic Simulation of Jet Engine Noise using Petaflop Computing Sponsor: National Science and supersonic jet noise prediction for modern-day turbofan aircraft engines using petascale computing. Jet noise that a 50% decrease in jet noise power output can be achieved by certain chevron and lobe mixer designs

  7. Methods for suppressing isomerization of olefin metathesis products

    SciTech Connect (OSTI)

    Firth, Bruce E.; Kirk, Sharon E.; Gavaskar, Vasudeo S.

    2015-09-22

    A method for suppressing isomerization of an olefin metathesis product produced in a metathesis reaction includes adding an isomerization suppression agent to a mixture that includes the olefin metathesis product and residual metathesis catalyst from the metathesis reaction under conditions that are sufficient to passivate at least a portion of the residual metathesis catalyst. The isomerization suppression agent is phosphorous acid, a phosphorous acid ester, phosphinic acid, a phosphinic acid ester or combinations thereof. Methods of refining natural oils are described.

  8. Vibration suppression, stabilization, motion planning and tracking for flexible beams

    E-Print Network [OSTI]

    Siranosian, Antranik Antonio

    2009-01-01

    B.2 The Virtual Vibration Absorber and Polynomial B.3vi B Experimental Vibration Suppression Results . . . . .H. Chen and C. M. Liaw, “Vibration acceleration control of

  9. A spray-suppression model for turbulent combustion

    SciTech Connect (OSTI)

    DESJARDIN,PAUL E.; TIESZEN,SHELDON R.; GRITZO,LOUIS A.

    2000-02-14

    A spray-suppression model that captures the effects of liquid suppressant on a turbulent combusting flow is developed and applied to a turbulent diffusion flame with water spray suppression. The spray submodel is based on a stochastic separated flow approach that accounts for the transport and evaporation of liquid droplets. Flame extinguishment is accounted for by using a perfectly stirred reactor (PSR) submodel of turbulent combustion. PSR pre-calculations of flame extinction times are determined using CHEMKIN and are compared to local turbulent time scales of the flow to determine if local flame extinguishment has occurred. The PSR flame extinguishment and spray submodels are incorporated into Sandia's flow fire simulation code, VULCAN, and cases are run for the water spray suppression studies of McCaffrey for turbulent hydrogen-air jet diffusion flames. Predictions of flame temperature decrease and suppression efficiency are compared to experimental data as a function of water mass loading using three assumed values of drop sizes. The results show that the suppression efficiency is highly dependent on the initial droplet size for a given mass loading. A predicted optimal suppression efficiency was observed for the smallest class of droplets while the larger drops show increasing suppression efficiency with increasing mass loading for the range of mass loadings considered. Qualitative agreement to the experiment of suppression efficiency is encouraging, however quantitative agreement is limited due to the uncertainties in the boundary conditions of the experimental data for the water spray.

  10. Desert dust suppressing precipitation: A possible desertification feedback loop

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    Desert dust suppressing precipitation: A possible desertification feedback loop Daniel Rosenfeld of land use exposing the topsoil can initiate such a desertification feedback process. Satellite

  11. SUPPRESSION OF STAR FORMATION IN NGC 1266

    SciTech Connect (OSTI)

    Alatalo, Katherine; Lanz, Lauranne; Bitsakis, Theodoros; Appleton, Philip N.; Ogle, Patrick M.; Lacy, Mark; Lonsdale, Carol J.; Nyland, Kristina; Meier, David S.; Cales, Sabrina L.; Chang, Philip; Davis, Timothy A.; De Zeeuw, P. T.; Martín, Sergio

    2015-01-01

    NGC 1266 is a nearby lenticular galaxy that harbors a massive outflow of molecular gas powered by the mechanical energy of an active galactic nucleus (AGN). It has been speculated that such outflows hinder star formation (SF) in their host galaxies, providing a form of feedback to the process of galaxy formation. Previous studies, however, indicated that only jets from extremely rare, high-power quasars or radio galaxies could impart significant feedback on their hosts. Here we present detailed observations of the gas and dust continuum of NGC 1266 at millimeter wavelengths. Our observations show that molecular gas is being driven out of the nuclear region at M-dot {sub out}?110 M{sub ?} yr{sup –1}, of which the vast majority cannot escape the nucleus. Only 2 M {sub ?} yr{sup –1} is actually capable of escaping the galaxy. Most of the molecular gas that remains is very inefficient at forming stars. The far-infrared emission is dominated by an ultra-compact (? 50 pc) source that could either be powered by an AGN or by an ultra-compact starburst. The ratio of the SF surface density (?{sub SFR}) to the gas surface density (?{sub H{sub 2}}) indicates that SF is suppressed by a factor of ?50 compared to normal star-forming galaxies if all gas is forming stars, and ?150 for the outskirt (98%) dense molecular gas if the central region is powered by an ultra-compact starburst. The AGN-driven bulk outflow could account for this extreme suppression by hindering the fragmentation and gravitational collapse necessary to form stars through a process of turbulent injection. This result suggests that even relatively common, low-power AGNs are able to alter the evolution of their host galaxies as their black holes grow onto the M-? relation.

  12. Diversity in ambient noise in European freshwater habitats: Noise levels, spectral profiles, and impact on fishes

    E-Print Network [OSTI]

    Ladich, Friedrich

    B re 1 Pa LLeq under no-wind conditions. Typically, most environmental noise is concentrated, and impact on fishes Lidia Eva Wysocki,a Sonja Amoser,b and Friedrich Ladichc Department of Behavioural of sound energy were present in the high frequency range above 1 kHz, leaving a low-energy "noise window

  13. Application of piezoelectric macro-fiber-composite actuators to the suppression of noise transmission through curved glass plates

    E-Print Network [OSTI]

    Novakova, Katerina; Vaclavik, Jan; 10.1109/TUFFC.2012.2420

    2012-01-01

    This paper analyzes the possibility of increasing the acoustic transmission loss of sound transmitted through planar or curved glass shells using attached piezoelectric macro fiber composite (MFC) actuators shunted by active circuits with a negative capacitance. The key features that control the sound transmission through the curved glass shells are analyzed using an analytical approximative model. A detailed analysis of the particular arrangement of MFC actuators on the glass shell is performed using a finite element method (FEM) model. The FEM model takes into account the effect of a flexible frame that clamps the glass shell at its edges. A method is presented for the active control of the Young's modulus and the bending stiffness coefficient of the composite sandwich structure that consists of a glass plate and the attached piezoelectric MFC actuator. The predictions of the acoustic transmission loss frequency dependencies obtained by the FEM model are compared with experimental data. The results indicate...

  14. High performance building blocks for wireless receiver: multi-stage amplifiers and low noise amplifiers 

    E-Print Network [OSTI]

    Fan, Xiaohua

    2009-05-15

    normally serves as the primary part of the system, which heavily influences the system performance. This research concentrates on the designs of several important blocks of the receiver; multi-stage amplifier and low noise amplifier. Two novel multi-stage...

  15. Ultrasensitive measurement of MEMS cantilever displacement sensitivity below the shot noise limit

    E-Print Network [OSTI]

    Pooser, R C

    2014-01-01

    The displacement of micro-electro-mechanical-systems(MEMs) cantilevers is used to measure a variety of phenomena in devices ranging from force microscopes for single spin detection[1] to biochemical sensors[2] to uncooled thermal imaging systems[3]. The displacement readout is often performed optically with segmented detectors or interference measurements. Until recently, various noise sources have limited the minimum detectable displacement in MEMs systems, but it is now possible to minimize all other sources[4] so that the noise level of the coherent light field, called the shot noise limit(SNL), becomes the dominant source. Light sources dis- playing quantum-enhanced statistics below this limit are available[5, 6], with applications in gravitational wave astronomy[7] and bioimaging[8], but direct displacement measurements of MEMS cantilevers below the SNL have been impossible until now. Here, we demonstrate the first direct measurement of a MEMs cantilever displacement with sub-SNL sensitivity, thus enabli...

  16. Collapse models with non-white noises

    E-Print Network [OSTI]

    Stephen L. Adler; Angelo Bassi

    2008-02-01

    We set up a general formalism for models of spontaneous wave function collapse with dynamics represented by a stochastic differential equation driven by general Gaussian noises, not necessarily white in time. In particular, we show that the non-Schrodinger terms of the equation induce the collapse of the wave function to one of the common eigenstates of the collapsing operators, and that the collapse occurs with the correct quantum probabilities. We also develop a perturbation expansion of the solution of the equation with respect to the parameter which sets the strength of the collapse process; such an approximation allows one to compute the leading order terms for the deviations of the predictions of collapse models with respect to those of standard quantum mechanics. This analysis shows that to leading order, the ``imaginary'' noise trick can be used for non-white Gaussian noise.

  17. Signal and noise in global warming detection. Final report

    SciTech Connect (OSTI)

    North, G.R.

    1998-11-01

    The specific objectives of this study were the following: (1) What is the expected sampling error and bias incurred in estimation of the global average temperature from a finite number of point gauges? (2) What is the best one can do by optimally arranging N point gauges, how can one make best use of existing data at N point gauges by optimally weighting them? (3) What is a good estimation of the signal of global warming based upon simple models of the climate system? (4) How does one develop an optimal signal detection technique from the knowledge of signal and noise?

  18. Exact solution of a model of qubit dephasing due to telegraph noise

    E-Print Network [OSTI]

    Bin Cheng; Qiang-Hua Wang; Robert Joynt

    2008-05-13

    We present a general and exact formalism for finding the evolution of a quantum system subject to external telegraph noise. The various qubit decoherence rates are determined by the eigenvalues of a transfer matrix. The formalism can be applied to a qubit subject to an arbitrary combination of dephasing and relaxational telegraph noise, in contrast to existing non-perturbative methods that treat only one or the other of these limits. We present 3 applications: 1) We obtain the full qubit dynamics on time scales short compared with the enviromental correlation times. In the strong coupling cases this reveals unexpected oscillations and induced magnetization components; 2) We find in strong coupling case strong violations of the widely used relation 1/T$_2$ = 1/2T$_1$ + 1/T$_{\\phi}$, which is a result of perturbation theory; 3) We discuss the effects of bang-bang and spin-echo controls of the qubit dynamics in general settings of the telegraph noises. %The result shows that these methods are not very effective in %reducing decoherence arising from a single telegraph noise. Finally, we discuss the extension of the method to the cases of many telegraph noise sources and multiple qubits. The method still works when white noise is also present.

  19. The power spectrum of the circular noise

    E-Print Network [OSTI]

    Daniel Müller

    2005-09-30

    The circular noise is important in connection to Mach's principle, and also as a possible probe of the Unruh effect. In this letter the power spectrum of the detector following the Trocheries-Takeno motion in the Minkowski vacuum is analytically obtained in the form of an infinite series. A mean distribution function and corresponding energy density are obtained for this particular detected noise. The analogous of a non constant temperature distribution is obtained. And in the end, a brief discussion about the equilibrium configuration is given.

  20. Amplitude modulation of wind turbine noise

    E-Print Network [OSTI]

    Makarewicz, Rufin

    2013-01-01

    Due to swish and thump amplitude modulation, the noise of wind turbines cause more annoyance than other environmental noise of the same average level. The wind shear accounts for the thump modulation (van den Berg effect). Making use of the wind speed measurements at the hub height, as well as at the top and the bottom of the rotor disc (Fig.1), the non-standard wind profile is applied. It causes variations in the A-weighted sound pressure level, LpA. The difference between the maximum and minimum of LpA characterizes thump modulation (Fig.2).

  1. Spin noise spectroscopy to probe quantum states of ultracold fermionic atomic gases

    E-Print Network [OSTI]

    Bogdan Mihaila; Scott A. Crooker; Krastan B. Blagoev; Dwight G. Rickel; Peter B. Littlewood; Darryl L. Smith

    2006-01-01

    Ultracold alkali atoms provide experimentally accessible model systems for probing quantum states that manifest themselves at the macroscopic scale. Recent experimental realizations of superfluidity in dilute gases of ultracold fermionic (half-integer spin) atoms offer exciting opportunities to directly test theoretical models of related many-body fermion systems that are inaccessible to experimental manipulation, such as neutron stars and quark-gluon plasmas. However, the microscopic interactions between fermions are potentially quite complex, and experiments in ultracold gases to date cannot clearly distinguish between the qualitatively different microscopic models that have been proposed. Here, we theoretically demonstrate that optical measurements of electron spin noise -- the intrinsic, random fluctuations of spin -- can probe the entangled quantum states of ultracold fermionic atomic gases and unambiguously reveal the detailed nature of the interatomic interactions. We show that different models predict different sets of resonances in the noise spectrum, and once the correct effective interatomic interaction model is identified, the line-shapes of the spin noise can be used to constrain this model. Further, experimental measurements of spin noise in classical (Boltzmann) alkali vapors are used to estimate the expected signal magnitudes for spin noise measurements in ultracold atom systems and to show that these measurements are feasible.

  2. Forest Fire Spread and Suppression in DEVS Lewis Ntaimo1

    E-Print Network [OSTI]

    Forest Fire Spread and Suppression in DEVS Lewis Ntaimo1 , Bithika Khargharia2 , Bernard P. Zeigler2 , Maria J. Vasconcelos3 Abstract In this paper we discuss modeling and simulation of forest fire simulation-based predictions of forest fire spread and suppression in uniform and non-uniform environmental

  3. Speculative Execution Exception Recovery Write-back Suppression

    E-Print Network [OSTI]

    Mahlke, Scott A.

    Speculative Execution Exception Recovery using Write-back Suppression Roger A. Bringmann Scott A or extra register pressure. This paper introduces a new architecture scheme referred to as write-back that with a modest amount of hardware, write- back suppression supports accurate reporting and handling of exceptions

  4. APPLICATIONS Forest Fire Spread and Suppression in DEVS

    E-Print Network [OSTI]

    Ntaimo, Lewis

    APPLICATIONS Forest Fire Spread and Suppression in DEVS Lewis Ntaimo Department of Industrial. Speedway Tucson, AZ 85721 In this article, the authors discuss modeling and simulation of forest fire to obtain timely simulation-based predictions of forest fire spread and suppression in uniform

  5. PPPL extends system for suppressing instabilities to long-pulse...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at instabilities called islands and generates electrical current that eliminates the islands. The process links software-controlled mirrors to detection equipment, creating a...

  6. Alamethicin Suppresses Methanogenesis and Promotes Acetogenesis in Bioelectrochemical Systems

    E-Print Network [OSTI]

    , or tides is used to drive CO2 conver- sion, this process is also an attractive method for energy storage Engineering, The Pennsylvania State University, University Park, Pennsylvania, USAa ; Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USAb Microbial

  7. Large Scale Power Suppression in a Multifield Landscape

    E-Print Network [OSTI]

    Blanco-Pillado, Jose J; Frazer, Jonathan; Sousa, Kepa

    2015-01-01

    Power suppression of the cosmic microwave background on the largest observable scales could provide valuable clues about the particle physics underlying inflation. Here we consider the prospect of power suppression in the context of the multifield landscape. Based on the assumption that our observable universe emerges from a tunnelling event and that the relevant features originate purely from inflationary dynamics, we find that the power spectrum not only contains information on single-field dynamics, but also places strong con- straints on all scalar fields present in the theory. We find that the simplest single-field models giving rise to power suppression do not generalise to multifield models in a straightforward way, as the resulting superhorizon evolution of the curvature perturbation tends to erase any power suppression present at horizon crossing. On the other hand, multifield effects do present a means of generating power suppression which to our knowledge has so far not been considered. We propose ...

  8. Interferometric at-wavelength flare characterization of EUV optical systems

    DOE Patents [OSTI]

    Naulleau, Patrick P. (Oakland, CA); Goldberg, Kenneth Alan (Berkeley, CA)

    2001-01-01

    The extreme ultraviolet (EUV) phase-shifting point diffraction interferometer (PS/PDI) provides the high-accuracy wavefront characterization critical to the development of EUV lithography systems. Enhancing the implementation of the PS/PDI can significantly extend its spatial-frequency measurement bandwidth. The enhanced PS/PDI is capable of simultaneously characterizing both wavefront and flare. The enhanced technique employs a hybrid spatial/temporal-domain point diffraction interferometer (referred to as the dual-domain PS/PDI) that is capable of suppressing the scattered-reference-light noise that hinders the conventional PS/PDI. Using the dual-domain technique in combination with a flare-measurement-optimized mask and an iterative calculation process for removing flare contribution caused by higher order grating diffraction terms, the enhanced PS/PDI can be used to simultaneously measure both figure and flare in optical systems.

  9. Majorana braiding with thermal noise

    E-Print Network [OSTI]

    Fabio L. Pedrocchi; David P. DiVincenzo

    2015-05-14

    We investigate the self-correcting properties of a network of Majorana wires, in the form of a trijunction, in contact with a parity-preserving thermal environment. As opposed to the case where Majoranas are immobile, braiding Majoranas within a trijunction introduces dangerous error processes that we identify. Such errors prevent the lifetime of the memory from increasing with the size of the system. We confirm our predictions with Monte Carlo simulations. Our findings put a fundamental restriction on the feasibility of this specific quantum computing architecture.

  10. Geometric phase of a qubit driven by a phase noise laser under non-Markovian dynamics

    SciTech Connect (OSTI)

    Berrada, K.

    2014-01-15

    Robustness of the geometric phase (GP) with respect to the environmental effects is a basic condition for an effective quantum computation. Here, we study quantitatively the GP of a two-level atom system driven by a phase noise laser under non-Markovian dynamics in terms of different parameters involved in the whole system. We find that with the change of the damping coupling, the GP is very sensitive to its properties exhibiting long collapse and revival phenomena, which play a significant role in enhancing the stabilization and control of the system dynamics. Moreover, we show that the GP can be considered as a tool for testing and characterizing the nature of the qubit–environment coupling. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement dynamics between the qubit with its environment under external classical noise is evaluated and investigated during the time evolution. -- Highlights: •Geometric phase under noise phase laser. •Dynamics of the geometric phase under non-Markovian dynamics in the presence of classical noise. •Solution of master equation of the system in terms atomic inversion. •Nonlocal correlation between the system and its environment under non-Markovianity.

  11. Acoustic Array Development for Wind Turbine Noise Characterization

    SciTech Connect (OSTI)

    Buck, S.; Roadman, J.; Moriarty, P.; Palo, S.

    2013-11-01

    This report discusses the design and use of a multi-arm, logarithmic spiral acoustic array by the National Renewable Energy Laboratory (NREL) for measurement and characterization of wind turbine-generated noise. The array was developed in collaboration with a team from the University of Colorado Boulder. This design process is a continuation of the elliptical array design work done by Simley. A description of the array system design process is presented, including array shape design, mechanical design, design of electronics and the data acquisition system, and development of post-processing software. System testing and calibration methods are detailed. Results from the initial data acquisition campaign are offered and discussed. Issues faced during this initial deployment of the array are presented and potential remedies discussed.

  12. Loss and thermal noise in plasmonic waveguides

    SciTech Connect (OSTI)

    Syms, R. R. A. Solymar, L.

    2014-06-07

    Rytov's theory of thermally generated radiation is used to find the noise in two-dimensional passive guides based on an arbitrary distribution of lossy isotropic dielectric. To simplify calculations, the Maxwell curl equations are approximated using difference equations that also permit a transmission-line analogy, and material losses are assumed to be low enough for modal losses to be estimated using perturbation theory. It is shown that an effective medium representation of each mode is valid for both loss and noise and, hence, that a one-dimensional model can be used to estimate the best achievable noise factor when a given mode is used in a communications link. This model only requires knowledge of the real and imaginary parts of the modal dielectric constant. The former can be found by solving the lossless eigenvalue problem, while the latter can be estimated using perturbation theory. Because of their high loss, the theory is most relevant to plasmonic waveguides, and its application is demonstrated using single interface, slab, and slot guide examples. The best noise performance is offered by the long-range plasmon supported by the slab guide.

  13. Sensors: Accelleration, light, temperature, pressure, noise & volume

    E-Print Network [OSTI]

    Beigl, Michael

    Smart-It Bridge Ethernet/IP Backbone RF Web- Server Developement PC Michael Beigl, Philip RobinsonSmart-Its ! ! ! ! ! Sensors: Accelleration, light, temperature, pressure, noise & volume Size: 4x1, 12kByte program Flash ROM Developement ! ! ! ! Wireless sensing & communication (Smart-Its) RF

  14. Architecture-Dependent Noise Discriminates Functionally Analogous

    E-Print Network [OSTI]

    Elowitz, Michael

    Architecture-Dependent Noise Discriminates Functionally Analogous Differentiation Circuits Tolga C.suel@utsouthwestern.edu DOI 10.1016/j.cell.2009.07.046 SUMMARY Gene regulatory circuits with different architectures (patterns architecture is selected to implement a given cellular process. To investigate this problem, wecomparedthe

  15. Dimensionality and noise in energy selective x-ray imaging

    SciTech Connect (OSTI)

    Alvarez, Robert E.

    2013-11-15

    Purpose: To develop and test a method to quantify the effect of dimensionality on the noise in energy selective x-ray imaging.Methods: The Cramčr-Rao lower bound (CRLB), a universal lower limit of the covariance of any unbiased estimator, is used to quantify the noise. It is shown that increasing dimensionality always increases, or at best leaves the same, the variance. An analytic formula for the increase in variance in an energy selective x-ray system is derived. The formula is used to gain insight into the dependence of the increase in variance on the properties of the additional basis functions, the measurement noise covariance, and the source spectrum. The formula is also used with computer simulations to quantify the dependence of the additional variance on these factors. Simulated images of an object with three materials are used to demonstrate the trade-off of increased information with dimensionality and noise. The images are computed from energy selective data with a maximum likelihood estimator.Results: The increase in variance depends most importantly on the dimension and on the properties of the additional basis functions. With the attenuation coefficients of cortical bone, soft tissue, and adipose tissue as the basis functions, the increase in variance of the bone component from two to three dimensions is 1.4 × 10{sup 3}. With the soft tissue component, it is 2.7 × 10{sup 4}. If the attenuation coefficient of a high atomic number contrast agent is used as the third basis function, there is only a slight increase in the variance from two to three basis functions, 1.03 and 7.4 for the bone and soft tissue components, respectively. The changes in spectrum shape with beam hardening also have a substantial effect. They increase the variance by a factor of approximately 200 for the bone component and 220 for the soft tissue component as the soft tissue object thickness increases from 1 to 30 cm. Decreasing the energy resolution of the detectors increases the variance of the bone component markedly with three dimension processing, approximately a factor of 25 as the resolution decreases from 100 to 3 bins. The increase with two dimension processing for adipose tissue is a factor of two and with the contrast agent as the third material for two or three dimensions is also a factor of two for both components. The simulated images show that a maximum likelihood estimator can be used to process energy selective x-ray data to produce images with noise close to the CRLB.Conclusions: The method presented can be used to compute the effects of the object attenuation coefficients and the x-ray system properties on the relationship of dimensionality and noise in energy selective x-ray imaging systems.

  16. Noise Reduction with Microphone Arrays for Speaker Identification

    SciTech Connect (OSTI)

    Cohen, Z

    2011-12-22

    Reducing acoustic noise in audio recordings is an ongoing problem that plagues many applications. This noise is hard to reduce because of interfering sources and non-stationary behavior of the overall background noise. Many single channel noise reduction algorithms exist but are limited in that the more the noise is reduced; the more the signal of interest is distorted due to the fact that the signal and noise overlap in frequency. Specifically acoustic background noise causes problems in the area of speaker identification. Recording a speaker in the presence of acoustic noise ultimately limits the performance and confidence of speaker identification algorithms. In situations where it is impossible to control the environment where the speech sample is taken, noise reduction filtering algorithms need to be developed to clean the recorded speech of background noise. Because single channel noise reduction algorithms would distort the speech signal, the overall challenge of this project was to see if spatial information provided by microphone arrays could be exploited to aid in speaker identification. The goals are: (1) Test the feasibility of using microphone arrays to reduce background noise in speech recordings; (2) Characterize and compare different multichannel noise reduction algorithms; (3) Provide recommendations for using these multichannel algorithms; and (4) Ultimately answer the question - Can the use of microphone arrays aid in speaker identification?

  17. Spin-noise correlations and spin-noise exchange driven by low-field spin-exchange collisions

    E-Print Network [OSTI]

    A. T. Dellis; M. Loulakis; I. K. Kominis

    2014-09-28

    The physics of spin exchange collisions have fueled several discoveries in fundamental physics and numerous applications in medical imaging and nuclear magnetic resonance. We here report on the experimental observation and theoretical justification of spin-noise exchange, the transfer of spin-noise from one atomic species to another. The signature of spin-noise exchange is an increase of the total spin-noise power at low magnetic fields, on the order of 1 mG, where the two-species spin-noise resonances overlap. The underlying physical mechanism is the two-species spin-noise correlation induced by spin-exchange collisions.

  18. A bootstrapped, low-noise, and high-gain photodetector for shot noise measurement

    SciTech Connect (OSTI)

    Zhou, Haijun; Yang, Wenhai; Li, Zhixiu; Li, Xuefeng; Zheng, Yaohui

    2014-01-15

    We presented a low-noise, high-gain photodetector based on the bootstrap structure and the L-C (inductance and capacitance) combination. Electronic characteristics of the photodetector, including electronic noise, gain and frequency response, and dynamic range, were verified through a single-frequency Nd:YVO{sub 4} laser at 1064 nm with coherent output. The measured shot noise of 50 ?W laser was 13 dB above the electronic noise at the analysis frequency of 2 MHz, and 10 dB at 3 MHz. And a maximum clearance of 28 dB at 2 MHz was achieved when 1.52 mW laser was illuminated. In addition, the photodetector showed excellent linearities for both DC and AC amplifications in the laser power range between 12.5 ?W and 1.52 mW.

  19. Collapse models with non-white noises II: particle-density coupled noises

    E-Print Network [OSTI]

    Stephen L. Adler; Angelo Bassi

    2008-08-22

    We continue the analysis of models of spontaneous wave function collapse with stochastic dynamics driven by non-white Gaussian noise. We specialize to a model in which a classical "noise" field, with specified autocorrelator, is coupled to a local nonrelativistic particle density. We derive general results in this model for the rates of density matrix diagonalization and of state vector reduction, and show that (in the absence of decoherence) both processes are governed by essentially the same rate parameters. As an alternative route to our reduction results, we also derive the Fokker-Planck equations that correspond to the initial stochastic Schr\\"odinger equation. For specific models of the noise autocorrelator, including ones motivated by the structure of thermal Green's functions, we discuss the qualitative and qantitative dependence on model parameters, with particular emphasis on possible cosmological sources of the noise field.

  20. Shot-Noise Seeded Microbunching Instability: Second-Order Correction to the Gain Function

    E-Print Network [OSTI]

    Venturini, Marco

    2008-01-01

    Microbunching from Shot Noise Using Vlasov Solvers, toShot-Noise Seeded Microbunching Instability: Second-Orderis seeded by shot noise. We examine an analytically

  1. Noise drives sharpening of gene expression boundaries in the zebrafish hindbrain

    E-Print Network [OSTI]

    Zhang, Lei; Radtke, Kelly; Zheng, Likun; Cai, Anna Q.; Schilling, Thomas F.; Nie, Qing

    2012-01-01

    Macmillan Publishers Limited Noise drives sharpening of genewww.molecularsystemsbiology.com Noise drives sharpening ofin morphogen concentration and noise in signal transduction

  2. Improved Indoor Tracking Based on Generalized t-Distribution Noise Model

    E-Print Network [OSTI]

    Shuo, Liu; Le, Yin; Khuen, Ho Weng; Voon, Ling Keck

    2015-01-01

    t distribution noise model. Industrial & EngineeringGeneralized t -Distribution Noise Model Liu Shuo Yin Le Hogeneralized t-distribution noise model based on influence

  3. ACOUSTIC VOCALIZATIONS OF DOLPHINS AND EFFECTS OF ANTHROPOGENIC NOISE 

    E-Print Network [OSTI]

    Bosquez, Joclyn Destiny

    2013-09-25

    analyses carried out in Hong Kong, I describe potential variations among communication between local delphinids due to effects of ambient noise and propose improvements and/or regulations that can help decrease man-made noise....

  4. Robust multiuser detection in ?-stable distribution non-Gaussian noise 

    E-Print Network [OSTI]

    Zhang, Jing

    2002-01-01

    In this thesis, we will model the ambient non-Gaussian noise as the ?-stable distribution because this model has many attractive properties. By using this noise model, the robust multiuser detectors achieve significant performance gain, and the two...

  5. Active noise control of supersonic impinging jet using pulsed microjets

    E-Print Network [OSTI]

    Hong, Seung Hyuck

    2009-01-01

    This thesis concerns an active noise control of supersonic impinging jet flow using unsteady microjet injection. Supersonic impinging jet involves several problems such as lift loss, ground erosion, significant noise ...

  6. Modeling and managing separation for noise abatement arrival procedures

    E-Print Network [OSTI]

    Ren, Liling

    2007-01-01

    Aircraft noise is a significant concern to communities near airports, and therefore a constraint to the growth of aviation. Advanced noise abatement approach and arrival procedures have been shown in previous studies and ...

  7. Ultra High Frequency Volatility Estimation with Dependent Microstructure Noise

    E-Print Network [OSTI]

    Ultra High Frequency Volatility Estimation with Dependent Microstructure Noise Yacine Aďt sampled at frequencies high enough for that noise to be a dominant consideration. We show that combining; Serial dependence; High frequency data; Realized volatility; Sub- sampling; Two Scales Realized

  8. Random Offset Curves and Surfaces with Controllable Noise (Extended Abstract)

    E-Print Network [OSTI]

    Lee, In-Kwon

    similar complex patterns often being able to be defined with the gradient noise functions. PORN is defined by replacing a static offset distance in a general offset with a gradient noise function. For example, PORN

  9. Negative Backaction Noise in Interferometric Detection of a Microlever

    E-Print Network [OSTI]

    J. Laurent; A. Mosset; O. Arcizet; J. Chevrier; S. Huant; H. Sellier

    2011-07-22

    Interferometric detection of mirror displacements is intrinsically limited by laser shot noise. In practice, however, it is often limited by thermal noise. Here we report on an experiment performed at the liquid helium temperature to overcome the thermal noise limitation and investigate the effect of classical laser noise on a microlever that forms a Fabry-Perot cavity with an optical fiber. The spectral noise densities show a region of negative contribution of the backaction noise close to the resonance frequency. We interpret this noise reduction as a coherent coupling of the microlever to the laser intensity noise. This optomechanical effect could be used to improve the detection sensitivity as discussed in proposals going beyond the Standard Quantum Limit.

  10. Noise removal at the rod synapse of mammalian retina 

    E-Print Network [OSTI]

    van Rossum, Mark; Smith, Robert

    1998-01-01

    Mammalian rods respond to single photons with a hyperpolarization of about 1 mV which is accompanied by continuous noise. Since the mammalian rod bipolar cell collects signals from 20-100 rods, the noise from the converging ...

  11. Active Vibration Suppression of Sandwich Beams using Piezoelectric Shear Actuators: Experiments and

    E-Print Network [OSTI]

    Vel, Senthil

    Active Vibration Suppression of Sandwich Beams using Piezoelectric Shear Actuators: Experiments assessment of the vibration suppression of smart structures using piezoelectric shear actuators. Experimental of the sandwich beam. Active vibration suppression is achieved using either positive position feedback or strain

  12. Separating Signal from Noise in Global Warming Bert W. Rust

    E-Print Network [OSTI]

    Rust, Bert W.

    Separating Signal from Noise in Global Warming Bert W. Rust Reprinted from the CD Rust, B. W. (2003) "Separating Signal from Noise in Global Warming," Computing Science and Statistics, 35, 263-277. ­ or ­ Rust, B. W. (2003) "Separating Signal from Noise in Global Warming," Computing Science and Statistics, 35

  13. Seeing red in cyclic stratigraphy: Spectral noise estimation for astrochronology

    E-Print Network [OSTI]

    Meyers, Stephen R.

    Seeing red in cyclic stratigraphy: Spectral noise estimation for astrochronology Stephen R. Meyers1.8% confidence level). Citation: Meyers, S. R. (2012), Seeing red in cyclic stratigraphy: Spectral noise is the time increment, rn is the red noise sequence, 0 r

  14. Noise in 3D Laser Range Scanner Data Xianfang Sun

    E-Print Network [OSTI]

    Martin, Ralph R.

    Noise in 3D Laser Range Scanner Data Xianfang Sun Cardiff University, UK Beihang University, China University, UK Abstract This paper discusses noise in range data measured by a Konica Mi- nolta Vivid 910 Gaussian noise, which is independently distributed at each mesh point. Measure- ments of an accurately

  15. Noise in protein expression scales with natural protein abundance

    E-Print Network [OSTI]

    Paulsson, Johan

    Noise in protein expression scales with natural protein abundance Arren Bar-Even1, Johan Paulsson2,3, Narendra Maheshri4, Miri Carmi1, Erin O'Shea4, Yitzhak Pilpel1 & Naama Barkai1,5 Noise in gene expression-specific regulation. Studies of individual promoters have suggested different dominating noise sources, raising

  16. NOISE AND ROOM ACOUSTICS DISTORTED SPEECH RECOGNITION BY HMM COMPOSITION

    E-Print Network [OSTI]

    Takiguchi, Tetsuya

    NOISE AND ROOM ACOUSTICS DISTORTED SPEECH RECOGNITION BY HMM COMPOSITION Satoshi NAKAMURA, Tetsuya method of an additive noise to that of the convolutional room acoustics distortion. The HMM composition, 2)Composition of distorted speech and noise HMMs in linear spectral domain. The speaker dependent

  17. NOISE REDUCTION TECHNIQUE FOR A SIMULATION OPTIMISATION STUDY

    E-Print Network [OSTI]

    Aickelin, Uwe

    1 NOISE REDUCTION TECHNIQUE FOR A SIMULATION OPTIMISATION STUDY Adrian Adewunmi*, Uwe Aickelin 11 to reducing the noise associated with such a procedure. We are applying this proposed solution approach to our and the variability of manual order picker skill. It is known that there is noise in the output of discrete event

  18. Noise as a Tool for Spoken Language Identification Sunita Maithani

    E-Print Network [OSTI]

    Noise as a Tool for Spoken Language Identification . Sunita Maithani Scientific Analysis Group@yahoo.com Abstract Segmental SNR (Signal to Noise Ratio) is considered to be a reasonable measure due to noise. Objective Measures such as Log Area Ratio (LAR), Itakura-Saitio Distortion (IS), Log

  19. Ship noise and cortisol secretion in European freshwater fishes

    E-Print Network [OSTI]

    Ladich, Friedrich

    Ship noise and cortisol secretion in European freshwater fishes Lidia Eva Wysocki*, John P. Dittami October 2005 Accepted 11 October 2005 Available online 28 November 2005 Keywords: Fish Ship noise Stress response Cortisol secretion Hearing A B S T R A C T Underwater noise pollution is a growing problem

  20. Noise as Therapy: A Prelude to Computationally-Based Neurology?

    E-Print Network [OSTI]

    Milton, John G.

    Noise as Therapy: A Prelude to Computationally-Based Neurology? Disturbances of the autonomic of pharmacological agents. The benefits were obtained by stimulating the vestibular nuclei with noise, i.e. electri de- signed to have the 1/f-type power spectrum character- istic of noise measured in the nervous

  1. Fast Adaptive Blue Noise on Polygonal Surfaces Esdras Medeirosa,

    E-Print Network [OSTI]

    Díaz, Lorenzo J.

    Fast Adaptive Blue Noise on Polygonal Surfaces Esdras Medeirosa, , Lis Ingridb , Sin´esio Pescob with blue noise characteristics, temporal-coherence and real-time computation. Classical algorithms produce preserving the good blue noise properties. We present applications on Non Photo Realistic rendering (NPR

  2. Blue Noise through Optimal Transport Fernando de Goes

    E-Print Network [OSTI]

    Desbrun, Mathieu

    Blue Noise through Optimal Transport Fernando de Goes Caltech Katherine Breeden Stanford Victor high-quality blue noise point distributions of arbitrary density functions. At its core is a novel diagrams. Our mathematical, algorithmic, and practical contributions lead to high-quality blue noise point

  3. Wind Noise Reduction in Single Channel Speech Signals

    E-Print Network [OSTI]

    Wind Noise Reduction in Single Channel Speech Signals Kristian Timm Andersen Kongens Lyngby 2008;Abstract In this thesis a number of wind noise reduction techniques have been reviewed, implemented and evaluated. The focus is on reducing wind noise from speech in single channel signals. More specically

  4. 1 Introduction 1 A Shot Noise Model For Financial Assets

    E-Print Network [OSTI]

    Schmidt, Thorsten

    1 Introduction 1 A Shot Noise Model For Financial Assets Timo Altmann, Thorsten Schmidt In this article we propose and study a model for stock prices which allows for shot-noise effects. This means forever. As we have argued above this may be unrealistic so that shot-noise models constitute useful

  5. Extending Stochastic Resonance for Neuron Models to General Levy Noise

    E-Print Network [OSTI]

    Applebaum, David

    Extending Stochastic Resonance for Neuron Models to General Levy Noise David Applebaum, Probability resonance for general feedback continuous and spiking neuron models using additive Levy noise constrained extends to general Levy noise models. We achieve this by showing that "large jump" discontinuities

  6. Statistical Modeling of Asynchronous Impulsive Noise in Powerline Communication Networks

    E-Print Network [OSTI]

    Evans, Brian L.

    Statistical Modeling of Asynchronous Impulsive Noise in Powerline Communication Networks Marcel statistics of asynchronous noise. In this paper, we (i) derive a canonical statistical-physical model readers interested in channel modeling to [1], [2], [3], [4], [5]. The non-Gaussian noise in PLC networks

  7. Wavepacket Modeling of the Jet Noise Source Dimitri Papamoschou*

    E-Print Network [OSTI]

    Papamoschou, Dimitri

    Wavepacket Modeling of the Jet Noise Source Dimitri Papamoschou* University of California, Irvine, CA 92697, USA This research is motivated by the need for physical models for the jet noise source be explained on the basis of a single noise source (the wavepacket), rather than the prevailing model of two

  8. A Model for Interlevel Coupling Noise in Multilevel Interconnect ' Structures

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    A Model for Interlevel Coupling Noise in Multilevel Interconnect ' Structures Martin Saint- case noise is simulated using an RC transmission line model that includes the timing of the attackers noise model is sometimes very desirable, in particular for the design of clock distribution networks

  9. Multiplicative colored noise in linearized models of biochemical reaction networks

    E-Print Network [OSTI]

    Ingalls, Brian

    Multiplicative colored noise in linearized models of biochemical reaction networks Matthew Scott is often modeled by white noise, though results obtained in this fashion tend to overstate the effect to a model of bacterial chemotaxis with multiple explicit noise sources. The frequency response

  10. MODEL COMPENSATION FOR NOISES IN TRAINING AND TEST DATA

    E-Print Network [OSTI]

    MODEL COMPENSATION FOR NOISES IN TRAINING AND TEST DATA Driss Matrouf and Jean-Luc Gauvain LIMSI on a channel model generally assume that the training data is noise-free, and the test data is noisy[1, 2, 3, 4 the channel type or the background noise characteristics is available, model com- pensation has

  11. Numerical Study of Noise Shielding by Airframe Structures Changzheng Huang*

    E-Print Network [OSTI]

    Papamoschou, Dimitri

    Numerical Study of Noise Shielding by Airframe Structures Changzheng Huang* and Dimitri Papamoschou-quiet advent aircraft that use jet noise shielding by the airframe. Current methods to predict shielding from predictive tools for jet noise shielding therefore requires a different approach. In this study we use

  12. Frequency noise and intensity noise of next-generation gravitational-wave detectors with RF/DC readout schemes

    E-Print Network [OSTI]

    K. Somiya; Y. Chen; S. Kawamura; N. Mio

    2007-01-29

    The sensitivity of next-generation gravitational-wave detectors such as Advanced LIGO and LCGT should be limited mostly by quantum noise with an expected technical progress to reduce seismic noise and thermal noise. Those detectors will employ the optical configuration of resonant-sideband-extraction that can be realized with a signal-recycling mirror added to the Fabry-Perot Michelson interferometer. While this configuration can reduce quantum noise of the detector, it can possibly increase laser frequency noise and intensity noise. The analysis of laser noise in the interferometer with the conventional configuration has been done in several papers, and we shall extend the analysis to the resonant-sideband-extraction configuration with the radiation pressure effect included. We shall also refer to laser noise in the case we employ the so-called DC readout scheme.

  13. Atom-based coherent quantum-noise cancellation in optomechanics

    E-Print Network [OSTI]

    F. Bariani; H. Seok; S. Singh; M. Vengalattore; P. Meystre

    2015-08-24

    We analyze a quantum force sensor that uses coherent quantum noise cancellation (CQNC) to beat the Standard Quantum Limit (SQL). This sensor, which allows for the continuous, broad-band detection of feeble forces, is a hybrid dual-cavity system comprised of a mesoscopic mechanical resonator optically coupled to an ensemble of ultracold atoms. In contrast to the stringent constraints on dissipation typically associated with purely optical schemes of CQNC, the dissipation rate of the mechanical resonator only needs to be matched to the decoherence rate of the atomic ensemble -- a condition that is experimentally achievable even for the technologically relevant regime of low frequency mechanical resonators with large quality factors. The modular nature of the system further allows the atomic ensemble to aid in the cooling of the mechanical resonator, thereby combining atom-mediated state preparation with sensing deep in the quantum regime.

  14. Atom-based coherent quantum-noise cancellation in optomechanics

    E-Print Network [OSTI]

    Bariani, F; Singh, S; Vengalattore, M; Meystre, P

    2015-01-01

    We analyze a quantum force sensor that uses coherent quantum noise cancellation (CQNC) to beat the Standard Quantum Limit (SQL). This sensor, which allows for the continuous, broad-band detection of feeble forces, is a hybrid dual-cavity system comprised of a mesoscopic mechanical resonator optically coupled to an ensemble of ultracold atoms. In contrast to the stringent constraints on dissipation typically associated with purely optical schemes of CQNC, the dissipation rate of the mechanical resonator only needs to be matched to the decoherence rate of the atomic ensemble -- a condition that is experimentally achievable even for the technologically relevant regime of low frequency mechanical resonators with large quality factors. The modular nature of the system further allows the atomic ensemble to aid in the cooling of the mechanical resonator, thereby combining atom-mediated state preparation with sensing deep in the quantum regime.

  15. Analysis of neutron noise spectra using neural networks

    SciTech Connect (OSTI)

    Korsah, K. (Oak Ridge National Lab., TN (USA)); Uhrig, R.E. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))

    1991-01-01

    Neural network architectures based on the back-propagation paradigm have been developed to recognize the features, and detect resonance shifts in, power spectral density (PSD) data. Our goal is to advance the state of the art in the application of noise analysis techniques to monitor nuclear reactor internals. The initial objectives have been to use PSD data, acquired over a period of about 2 years by PSDREC (power spectral density recognition system), to develop neural networks that are able to differentiate between normal neutron power spectral density data and anomalous spectral data, and detect significant shifts in the positions of spectral resonances while reducing the effect of small shifts. Neural network systems referred to in this paper as spectral feature detectors (SFDs) and integral network filters have been developed to meet these objectives. The performance of the SFDs is the subject of this paper. 2 refs., 2 figs.

  16. Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pazsit

    E-Print Network [OSTI]

    Pázsit, Imre

    Review Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pa´zsit Chalmers University of Technology, Department of Nuclear Engineering, SE-412 96 Go¨teborg, Sweden Abstract systems in two-group theory, a code was developed for the calculation of the Green's function (dynamic

  17. Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pazsit

    E-Print Network [OSTI]

    Demazičre, Christophe

    Review Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pa and application of the numerical tools employed. The code that was developed yields the space and non-critical systems with an external source. Some appli- cations of these tools to power reactor

  18. Application of Numerical Noise Titration during Autonomic Blockade S Vandeput1

    E-Print Network [OSTI]

    rate variability (HRV) and blood pressure variability (BPV) in rats using the nonlinear numerical noise spectral compo- nents of heart rate variability (HRV) and sympathetic and vagal modulation, many studies have emerged describing this influence of the autonomic nervous system (ANS) on HRV [2, 3

  19. Influence of refraction on wind turbine noise

    E-Print Network [OSTI]

    Makarewicz, Rufin

    2013-01-01

    A semi-empirical method is applied to calculate the time-average sound level of wind turbine noise generation and propagation. Both are affected by wind shear refraction. Under upwind conditions the partially ensonified zone separates the fully ensonified zone (close to the turbine) and the shadow zone (far away from the turbine). Refraction is described in terms of the wind speed linear profile fitted to the power law profile. The rotating blades are treated as a two-dimensional circular source in the vertical plane. Inside the partially ensonified zone the effective A-weighted sound power decreases to zero when the receiver moves from the turbine toward the shadow zone. The presented results would be useful in practical applications to give a quick estimate of the effect of refraction on wind turbine noise.

  20. Environmental Noise and Decision Making Possible Implications of Increases in Anthropogenic Noise for Information Processing in Marine Mammals

    E-Print Network [OSTI]

    Bateson, Melissa

    2007-01-01

    events such as white noise or quinine-tainted food. It iswere associated with unpalatable quinine-injected mealworms

  1. Estimating Suppression of Eddy Mixing by Mean Flows

    E-Print Network [OSTI]

    Klocker, Andreas

    Particle- and tracer-based estimates of lateral diffusivities are used to estimate the suppression of eddy mixing across strong currents. Particles and tracers are advected using a velocity field derived from sea surface ...

  2. Mutations that suppress the thermosensitivity of green fluorescent protein

    E-Print Network [OSTI]

    Haseloff, Jim

    Mutations that suppress the thermosensitivity of green fluorescent protein Kirby R. Siemering*, Ralph Golbik, Richard Sever* and Jim Haseloff* Background: The green fluorescent protein (GFP temperatures. Background The green fluorescent protein (GFP) from the bio- luminescent jellyfish Aequorea

  3. J/Psi suppression in ultrarelativistic nuclear collisions 

    E-Print Network [OSTI]

    Zhang, B.; Ko, Che Ming; Li, Ba; Lin, ZW; Sa, BW.

    2000-01-01

    Using a multiphase transport model, we study the relative importance of J/psi suppression mechanisms due to plasma screening, gluon scattering, and hadron absorption in heavy ion collisions at the Relativistic Heavy Ion ...

  4. Nuclear Suppression of Dileptons at Large xF

    E-Print Network [OSTI]

    J. Cepila; J. Nemchik

    2009-10-09

    We study a significant nuclear suppression of the relative production rates (p(d)+A)/(p+d(p)) for the Drell-Yan process at large Feynman xF. Since this is the region of minimal values for the light-front momentum fraction variable x2 in the target nucleus, it is tempting to interpret this as a manifestation of coherence or of a Color Glass Condensate. We demonstrate, however, that this suppression mechanism is governed by the energy conservation restrictions in multiple parton rescatterings in nuclear matter. To eliminate nuclear shadowing effects coming from the coherence, we calculate nuclear suppression in the light-cone dipole approach at large dilepton masses and at energy accessible at FNAL. Our calculations are in a good agreement with data from the E772 experiment. Using the same mechanism we predict also nuclear suppression at forward rapidities in the RHIC energy range.

  5. Suppression of Cavity Formation in Ceramics: Prospects for Superplasticity

    E-Print Network [OSTI]

    Suppression of Cavity Formation in Ceramics: Prospects for Superplasticity A. G. EVANS* Materials, Ohio State University, Columbus, Ohio 43210 Ceramics exhibit macroscopic stressistrain rate relations- tive surface diffusivities must be selected. I. Introduction HEN polycrystalline ceramic materials

  6. Heat Equations with Fractional White Noise Potentials

    SciTech Connect (OSTI)

    Hu, Y. [Department of Mathematics, University of Kansas, 405 Snow Hall, Lawrence, KS 66045-2142 (United States)], E-mail: hu@math.ukans.edu

    2001-07-01

    This paper is concerned with the following stochastic heat equations: ({partial_derivative}u{sub t}(x))/({partial_derivative}t=1/2 u{sub t}(x)+{omega}{sup H}.u{sub t}(x)), x element of {sup d}, t>0, where w{sup H} is a time independent fractional white noise with Hurst parameter H=(h{sub 1}, h{sub 2},..., h{sub d}) , or a time dependent fractional white noise with Hurst parameter H=(h{sub 0}, h{sub 1},..., h{sub d}) . Denote | H | =h{sub 1}+h{sub 2}+...+h{sub d} . When the noise is time independent, it is shown that if 1/2 d-1 , then the solution is in L{sub 2} and the L{sub 2} -Lyapunov exponent of the solution is estimated. When the noise is time dependent, it is shown that if 1/2 d- 2 /( 2h{sub 0}-1 ) , the solution is in L{sub 2} and the L{sub 2} -Lyapunov exponent of the solution is also estimated. A family of distribution spaces S{sub {rho}} , {rho} element of RR , is introduced so that every chaos of an element in S{sub {rho}} is in L{sub 2} . The Lyapunov exponents in S{sub {rho}} of the solution are also estimated.

  7. Nonequilibrium noise in electrophoresis: the microion wind

    E-Print Network [OSTI]

    Suropriya Saha; Sriram Ramaswamy

    2009-07-02

    We analyze theoretically the dynamics of a single colloidal particle in an externally applied electric field. The thermal motions of microions lead to an anisotropic, nonequilibrium source of noise, pro- portional to the field, in the effective Langevin equation for the colloid. The fluctuation-dissipation ratio depends strongly on frequency, and the colloid if displaced from its steady-state position relaxes with a velocity not proportional to the gradient of the logarithm of the steady-state probability.

  8. Suppression of Heterodera schachtii Populations by Dactylella oviparasitica in Four Soils

    E-Print Network [OSTI]

    Olatinwo, R; Becker, J Ole; Borneman, J

    2006-01-01

    R. Keeney, eds. Methods of soil analysis: Part 2. Chemicalresponsible for speci?c soil suppressiveness to plantto nonsuppressive soil produced stable suppressiveness over

  9. Shot-noise-limited magnetometer with sub-picotesla sensitivity at room temperature

    SciTech Connect (OSTI)

    Lucivero, Vito Giovanni; Anielski, Pawel; Gawlik, Wojciech; Mitchell, Morgan W.

    2014-11-15

    We report a photon shot-noise-limited (SNL) optical magnetometer based on amplitude modulated optical rotation using a room-temperature {sup 85}Rb vapor in a cell with anti-relaxation coating. The instrument achieves a room-temperature sensitivity of 70 fT/?(Hz) at 7.6 ?T. Experimental scaling of noise with optical power, in agreement with theoretical predictions, confirms the SNL behaviour from 5 ?T to 75??T. The combination of best-in-class sensitivity and SNL operation makes the system a promising candidate for application of squeezed light to a state-of-the-art atomic sensor.

  10. Dynamical model for the quantum-to-classical crossover of shot noise

    E-Print Network [OSTI]

    J. Tworzydlo; A. Tajic; H. Schomerus; C. W. J. Beenakker

    2003-07-07

    We use the open kicked rotator to model the chaotic scattering in a ballistic quantum dot coupled by two point contacts to electron reservoirs. By calculating the system-size-over-wave-length dependence of the shot noise power we study the crossover from wave to particle dynamics. Both a fully quantum mechanical and a semiclassical calculation are presented. We find numerically in both approaches that the noise power is reduced exponentially with the ratio of Ehrenfest time and dwell time, in agreement with analytical predictions.

  11. Acoustic Noise Test Report for the SWIFT Wind Turbine in Boulder, CO

    SciTech Connect (OSTI)

    Roadman, J.; Huskey, A.

    2013-04-01

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the SWIFT is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and utilized binning by wind speed instead of regression analysis.

  12. Acoustic Noise Test Report for the Viryd CS8 Wind Turbine

    SciTech Connect (OSTI)

    Roadman, J.; Huskey, A.

    2013-07-01

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the Viryd CS8 is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and binning by wind speed instead of regression analysis.

  13. Modelling the effect of charge noise on the exchange interaction between spins

    E-Print Network [OSTI]

    M. J. Testolin; J. H. Cole; L. C. L. Hollenberg

    2009-04-01

    We describe how the effect of charge noise on a pair of spins coupled via the exchange interaction can be calculated by modelling charge fluctuations as a random telegraph noise process using probability density functions. We develop analytic expressions for the time dependent superoperator of a pair of spins as a function of fluctuation amplitude and rate. We show that the theory can be extended to include multiple fluctuators, in particular, spectral distributions of fluctuators. These superoperators can be included in time dependent analyses of the state of spin systems designed for spintronics or quantum information processing to determine the decohering effects of exchange fluctuations.

  14. Shot-noise-limited magnetometer with sub-pT sensitivity at room temperature

    E-Print Network [OSTI]

    Vito Giovanni Lucivero; Pawel Anielski; Wojciech Gawlik; Morgan W. Mitchell

    2014-11-20

    We report a photon shot-noise-limited (SNL) optical magnetometer based on amplitude modulated optical rotation using a room-temperature $^{85}$Rb vapor in a cell with anti-relaxation coating. The instrument achieves a room-temperature sensitivity of $70$ fT/$\\sqrt{\\mathrm{Hz}}$ at $7.6$ $\\mu$T. Experimental scaling of noise with optical power, in agreement with theoretical predictions, confirms the SNL behaviour from $5$ $\\mu$T to $75$ $\\mu$T. The combination of best-in-class sensitivity and SNL operation makes the system a promising candidate for application of squeezed light to a state-of-the-art atomic sensor.

  15. Methods for suppressing isomerization of olefin metathesis products

    SciTech Connect (OSTI)

    Firth, Bruce E.; Kirk, Sharon E.

    2015-10-27

    A method for suppressing isomerization of an olefin metathesis product produced in a metathesis reaction includes adding an isomerization suppression agent that includes nitric acid to a mixture that includes the olefin metathesis product and residual metathesis catalyst from the metathesis reaction under conditions that are sufficient to passivate at least a portion of the residual metathesis catalyst. Methods of refining a natural oil are described.

  16. Noise performance of magneto-inductive cables

    SciTech Connect (OSTI)

    Wiltshire, M. C. K. Syms, R. R. A.

    2014-07-21

    Magneto-inductive (MI) waveguides are metamaterial structures based on periodic arrangements of inductively coupled resonant magnetic elements. They are of interest for power transfer, communications and sensing, and can be realised in a flexible cable format. Signal-to-noise ratio is extremely important in applications involving signals. Here, we present the first experimental measurements of the noise performance of metamaterial cables. We focus on an application involving radiofrequency signal transmission in internal magnetic resonance imaging (MRI), where the subdivision of the metamaterial cable provides intrinsic patient safety. We consider MI cables suitable for use at 300 MHz during {sup 1}H MRI at 7 T, and find noise figures of 2.3–2.8?dB/m, together with losses of 3.0–3.9?dB/m, in good agreement with model calculations. These values are high compared to conventional cables, but become acceptable when (as here) the environment precludes the use of continuous conductors. To understand this behaviour, we present arguments for the fundamental performance limitations of these cables.

  17. Squeezed-light spin noise spectroscopy

    E-Print Network [OSTI]

    Lucivero, Vito Giovanni; Kong, Jia; Mitchell, Morgan W

    2015-01-01

    We report quantum enhancement of Faraday rotation spin noise spectroscopy by polarization squeezing of the probe beam. Using natural abundance Rb in \\SI{100}{Torr}of N$_2$ buffer gas, and squeezed light from a sub-threshold optical parametric oscillator stabilized \\SI{20}{GHz}to the blue of the D$_1$ resonance, we observe that an input squeezing of \\SI{3.0}{dB} improves the signal-to-noise ratio by \\SI{1.5}{dB} to \\SI{2.6}{dB} over the combined (power)$\\otimes$(number density) ranges (\\SI{0.5}{mW} to \\SI{4.0}{mW})$\\otimes$(\\SI{1.5d12}{cm\\tothe{-3}} to \\SI{1.3d13}{cm\\tothe{-3}}), covering the full practical range and into the strongly-perturbed regime. We show that in these conditions squeezing improves the trade-off between statistical noise and systematic shifts, a new kind of quantum advantage.

  18. Squeezed-light spin noise spectroscopy

    E-Print Network [OSTI]

    Vito Giovanni Lucivero; Ricardo Jiménez-Martínez; Jia Kong; Morgan W. Mitchell

    2015-09-18

    We report quantum enhancement of Faraday rotation spin noise spectroscopy by polarization squeezing of the probe beam. Using natural abundance Rb in \\SI{100}{Torr}of N$_2$ buffer gas, and squeezed light from a sub-threshold optical parametric oscillator stabilized \\SI{20}{GHz}to the blue of the D$_1$ resonance, we observe that an input squeezing of \\SI{3.0}{dB} improves the signal-to-noise ratio by \\SI{1.5}{dB} to \\SI{2.6}{dB} over the combined (power)$\\otimes$(number density) ranges (\\SI{0.5}{mW} to \\SI{4.0}{mW})$\\otimes$(\\SI{1.5d12}{cm\\tothe{-3}} to \\SI{1.3d13}{cm\\tothe{-3}}), covering the full practical range and into the strongly-perturbed regime. We show that in these conditions squeezing improves the trade-off between statistical noise and systematic shifts, a new kind of quantum advantage.

  19. A compact, multichannel, and low noise arbitrary waveform generator

    SciTech Connect (OSTI)

    Govorkov, S.; Ivanov, B. I.; Novosibirsk State Technical University, K.Marx-Ave. 20, Novosibirsk 630092 ; Il'ichev, E.; Meyer, H.-G.

    2014-05-15

    A new type of high functionality, fast, compact, and easy programmable arbitrary waveform generator for low noise physical measurements is presented. The generator provides 7 fast differential waveform channels with a maximum bandwidth up to 200 MHz frequency. There are 6 fast pulse generators on the generator board with 78 ps time resolution in both duration and delay, 3 of them with amplitude control. The arbitrary waveform generator is additionally equipped with two auxiliary slow 16 bit analog-to-digital converters and four 16 bit digital-to-analog converters for low frequency applications. Electromagnetic shields are introduced to the power supply, digital, and analog compartments and with a proper filter design perform more than 110 dB digital noise isolation to the output signals. All the output channels of the board have 50 ? SubMiniature version A termination. The generator board is suitable for use as a part of a high sensitive physical equipment, e.g., fast read out and manipulation of nuclear magnetic resonance or superconducting quantum systems and any other application, which requires electromagnetic interference free fast pulse and arbitrary waveform generation.

  20. S4: A spatial-spectral model for speckle suppression

    SciTech Connect (OSTI)

    Fergus, Rob; Hogg, David W.; Oppenheimer, Rebecca; Brenner, Douglas; Pueyo, Laurent

    2014-10-20

    High dynamic range imagers aim to block or eliminate light from a very bright primary star in order to make it possible to detect and measure far fainter companions; in real systems, a small fraction of the primary light is scattered, diffracted, and unocculted. We introduce S4, a flexible data-driven model for the unocculted (and highly speckled) light in the P1640 spectroscopic coronagraph. The model uses principal components analysis (PCA) to capture the spatial structure and wavelength dependence of the speckles, but not the signal produced by any companion. Consequently, the residual typically includes the companion signal. The companion can thus be found by filtering this error signal with a fixed companion model. The approach is sensitive to companions that are of the order of a percent of the brightness of the speckles, or up to 10{sup –7} times the brightness of the primary star. This outperforms existing methods by a factor of two to three and is close to the shot-noise physical limit.

  1. CMB quadrupole suppression: II. The early fast roll stage

    E-Print Network [OSTI]

    D. Boyanovsky; H. J. de Vega; N. G. Sanchez

    2007-03-12

    Within the effective field theory of inflation, an initialization of the classical dynamics of the inflaton with approximate equipartition between the kinetic and potential energy of the inflaton leads to a brief fast roll stage that precedes the slow roll regime. The fast roll stage leads to an attractive potential in the wave equations for the mode functions of curvature and tensor perturbations. The evolution of the inflationary perturbations is equivalent to the scattering by this potential and a useful dictionary between the scattering data and observables is established.Implementing methods from scattering theory we prove that this attractive potential leads to a suppression of the quadrupole moment for CMB and B-mode angular power spectra. The scale of the potential is determined by the Hubble parameter during slow roll. Within the effective field theory of inflation at the grand unification (GUT) energy scale we find that if inflation lasts a total number of efolds N_{tot} ~ 59, there is a 10-20% suppression of the CMB quadrupole and about 2-4% suppression of the tensor quadrupole. The suppression of higher multipoles is smaller, falling off as 1/l^2. The suppression is much smaller for N_{tot} > 59, therefore if the observable suppression originates in the fast roll stage, there is the upper bound N_{tot} ~ 59.

  2. Evaluating charge noise acting on semiconductor quantum dots in the circuit quantum electrodynamics architecture

    SciTech Connect (OSTI)

    Basset, J.; Stockklauser, A.; Jarausch, D.-D.; Frey, T.; Reichl, C.; Wegscheider, W.; Wallraff, A.; Ensslin, K.; Ihn, T.

    2014-08-11

    We evaluate the charge noise acting on a GaAs/GaAlAs based semiconductor double quantum dot dipole-coupled to the voltage oscillations of a superconducting transmission line resonator. The in-phase (I) and the quadrature (Q) components of the microwave tone transmitted through the resonator are sensitive to charging events in the surrounding environment of the double dot with an optimum sensitivity of 8.5×10{sup ?5}?e/?(Hz). A low frequency 1/f type noise spectrum combined with a white noise level of 6.6×10{sup ?6} e{sup 2}/Hz above 1?Hz is extracted, consistent with previous results obtained with quantum point contact charge detectors on similar heterostructures. The slope of the 1/f noise allows to extract a lower bound for the double-dot charge qubit dephasing rate which we compare to the one extracted from a Jaynes-Cummings Hamiltonian approach. The two rates are found to be similar emphasizing that charge noise is the main source of dephasing in our system.

  3. Dependence of the colored frequency noise in spin torque oscillators on current and magnetic field

    SciTech Connect (OSTI)

    Eklund, Anders Sani, Sohrab R.; Chung, Sunjae; Amir Hossein Banuazizi, S.; Östling, Mikael; Gunnar Malm, B.; Bonetti, Stefano; Majid Mohseni, S.; Persson, Johan; Iacocca, Ezio; Ĺkerman, Johan

    2014-03-03

    The nano-scale spin torque oscillator (STO) is a compelling device for on-chip, highly tunable microwave frequency signal generation. Currently, one of the most important challenges for the STO is to increase its longer-time frequency stability by decreasing the 1/f frequency noise, but its high level makes even its measurement impossible using the phase noise mode of spectrum analyzers. Here, we present a custom made time-domain measurement system with 150?MHz measurement bandwidth making possible the investigation of the variation of the 1/f as well as the white frequency noise in a STO over a large set of operating points covering 18–25?GHz. The 1/f level is found to be highly dependent on the oscillation amplitude-frequency non-linearity and the vicinity of unexcited oscillation modes. These findings elucidate the need for a quantitative theoretical treatment of the low-frequency, colored frequency noise in STOs. Based on the results, we suggest that the 1/f frequency noise possibly can be decreased by improving the microstructural quality of the metallic thin films.

  4. Direct-to-digital holography reduction of reference hologram noise and fourier space smearing

    DOE Patents [OSTI]

    Voelkl, Edgar

    2006-06-27

    Systems and methods are described for reduction of reference hologram noise and reduction of Fourier space smearing, especially in the context of direct-to-digital holography (off-axis interferometry). A method of reducing reference hologram noise includes: recording a plurality of reference holograms; processing the plurality of reference holograms into a corresponding plurality of reference image waves; and transforming the corresponding plurality of reference image waves into a reduced noise reference image wave. A method of reducing smearing in Fourier space includes: recording a plurality of reference holograms; processing the plurality of reference holograms into a corresponding plurality of reference complex image waves; transforming the corresponding plurality of reference image waves into a reduced noise reference complex image wave; recording a hologram of an object; processing the hologram of the object into an object complex image wave; and dividing the complex image wave of the object by the reduced noise reference complex image wave to obtain a reduced smearing object complex image wave.

  5. Reversible Electron Beam Heating for Suppression of Microbunching Instabilities at Free-Electron Lasers

    SciTech Connect (OSTI)

    Behrens, Christopher; /DESY; Huang, Zhirong; Xiang, Dao; /SLAC

    2012-05-30

    The presence of microbunching instabilities due to the compression of high-brightness electron beams at existing and future x-ray free-electron lasers (FELs) results in restrictions on the attainable lasing performance and renders beam imaging with optical transition radiation impossible. The instability can be suppressed by introducing additional energy spread, i.e., heating the electron beam, as demonstrated by the successful operation of the laser heater system at the Linac Coherent Light Source. The increased energy spread is typically tolerable for self-amplified spontaneous emission FELs but limits the effectiveness of advanced FEL schemes such as seeding. In this paper, we present a reversible electron beam heating system based on two transverse deflecting radio-frequency structures (TDSs) upstream and downstream of a magnetic bunch compressor chicane. The additional energy spread is introduced in the first TDS, which suppresses the microbunching instability, and then is eliminated in the second TDS. We show the feasibility of the microbunching gain suppression based on calculations and simulations including the effects of coherent synchrotron radiation. Acceptable electron beam and radio-frequency jitter are identified, and inherent options for diagnostics and on-line monitoring of the electron beam's longitudinal phase space are discussed.

  6. Charge noise, spin-orbit coupling, and dephasing of single-spin qubits

    SciTech Connect (OSTI)

    Bermeister, Adam; Keith, Daniel; Culcer, Dimitrie

    2014-11-10

    Quantum dot quantum computing architectures rely on systems in which inversion symmetry is broken, and spin-orbit coupling is present, causing even single-spin qubits to be susceptible to charge noise. We derive an effective Hamiltonian for the combined action of noise and spin-orbit coupling on a single-spin qubit, identify the mechanisms behind dephasing, and estimate the free induction decay dephasing times T{sub 2}{sup *} for common materials such as Si and GaAs. Dephasing is driven by noise matrix elements that cause relative fluctuations between orbital levels, which are dominated by screened whole charge defects and unscreened dipole defects in the substrate. Dephasing times T{sub 2}{sup *} differ markedly between materials and can be enhanced by increasing gate fields, choosing materials with weak spin-orbit, making dots narrower, or using accumulation dots.

  7. Suppression of the four-wave mixing amplification via Raman absorption

    E-Print Network [OSTI]

    Romanov, Gleb; Novikova, I

    2015-01-01

    We propose a method to controllably suppress the effect of the four-wave mixing caused by the coupling of the strong control optical field to both optical transitions in the $\\Lambda$ system under the conditions of electromagnetically induced transparency. At sufficiently high atomic density, this process leads to amplification of a weak optical signal field, that is detrimental for the fidelity of any EIT-based quantum information applications. Here we show that an additional absorption resonance centered around the idler field frequency, generated in such a four-wave mixing process, may efficiently suppress the unwanted signal amplification without affecting properties of the EIT interaction. We discuss the possibility of creating such tunable absorption using two-photon Raman absorption resonances in the other Rb isotope, and present some preliminary experimental results.

  8. Suppression criteria of parasitic mode oscillations in a gyrotron beam tunnel

    SciTech Connect (OSTI)

    Kumar, Nitin; Singh, Udaybir; Sinha, A. K.; Singh, T. P.

    2011-02-15

    This paper presents the design criteria of the parasitic mode oscillations suppression for a periodic, ceramic, and copper loaded gyrotron beam tunnel. In such a type of beam tunnel, the suppression of parasitic mode oscillations is an important design problem. A method of beam-wave coupling coefficient and its mathematical formulation are presented. The developed design criteria are used in the beam tunnel design of a 42 GHz gyrotron to be developed for the Indian TOKAMAK system. The role of the thickness and the radius of the beam tunnel copper rings to obtain the developed design criteria are also discussed. The commercially available electromagnetic code CST and the electron trajectory code EGUN are used for the simulations.

  9. Shot-noise-limited optical Faraday polarimetry with enhanced laser noise cancelling

    SciTech Connect (OSTI)

    Li, Jiaming; Luo, Le Carvell, Jeff; Cheng, Ruihua; Lai, Tianshu Wang, Zixin

    2014-03-14

    We present a shot-noise-limited measurement of optical Faraday rotations with sub-ten-nanoradian angular sensitivity. This extremely high sensitivity is achieved by using electronic laser noise cancelling and phase sensitive detection. Specially, an electronic laser noise canceller with a common mode rejection ratio of over 100?dB was designed and built for enhanced laser noise cancelling. By measuring the Faraday rotation of ambient air, we demonstrate an angular sensitivity of up to 9.0×10{sup ?9}?rad/?(Hz), which is limited only by the shot-noise of the photocurrent of the detector. To date, this is the highest angular sensitivity ever reported for Faraday polarimeters in the absence of cavity enhancement. The measured Verdet constant of ambient air, 1.93(3)×10{sup ?9}rad/(G?cm) at 633?nm wavelength, agrees extremely well with the earlier experiments using high finesse optical cavities. Further, we demonstrate the applications of this sensitive technique in materials science by measuring the Faraday effect of an ultrathin iron film.

  10. Image simulation and a model of noise power spectra across a range of mammographic beam qualities

    SciTech Connect (OSTI)

    Mackenzie, Alistair Dance, David R.; Young, Kenneth C.; Diaz, Oliver

    2014-12-15

    Purpose: The aim of this work is to create a model to predict the noise power spectra (NPS) for a range of mammographic radiographic factors. The noise model was necessary to degrade images acquired on one system to match the image quality of different systems for a range of beam qualities. Methods: Five detectors and x-ray systems [Hologic Selenia (ASEh), Carestream computed radiography CR900 (CRc), GE Essential (CSI), Carestream NIP (NIPc), and Siemens Inspiration (ASEs)] were characterized for this study. The signal transfer property was measured as the pixel value against absorbed energy per unit area (E) at a reference beam quality of 28 kV, Mo/Mo or 29 kV, W/Rh with 45 mm polymethyl methacrylate (PMMA) at the tube head. The contributions of the three noise sources (electronic, quantum, and structure) to the NPS were calculated by fitting a quadratic at each spatial frequency of the NPS against E. A quantum noise correction factor which was dependent on beam quality was quantified using a set of images acquired over a range of radiographic factors with different thicknesses of PMMA. The noise model was tested for images acquired at 26 kV, Mo/Mo with 20 mm PMMA and 34 kV, Mo/Rh with 70 mm PMMA for three detectors (ASEh, CRc, and CSI) over a range of exposures. The NPS were modeled with and without the noise correction factor and compared with the measured NPS. A previous method for adapting an image to appear as if acquired on a different system was modified to allow the reference beam quality to be different from the beam quality of the image. The method was validated by adapting the ASEh flat field images with two thicknesses of PMMA (20 and 70 mm) to appear with the imaging characteristics of the CSI and CRc systems. Results: The quantum noise correction factor rises with higher beam qualities, except for CR systems at high spatial frequencies, where a flat response was found against mean photon energy. This is due to the dominance of secondary quantum noise in CR. The use of the quantum noise correction factor reduced the difference from the model to the real NPS to generally within 4%. The use of the quantum noise correction improved the conversion of ASEh image to CRc image but had no difference for the conversion to CSI images. Conclusions: A practical method for estimating the NPS at any dose and over a range of beam qualities for mammography has been demonstrated. The noise model was incorporated into a methodology for converting an image to appear as if acquired on a different detector. The method can now be extended to work for a wide range of beam qualities and can be applied to the conversion of mammograms.

  11. ACOUSTIC AND LANGUAGE MODELING OF HUMAN AND NONHUMAN NOISES FOR HUMANTOHUMAN SPONTANEOUS SPEECH RECOGNITION

    E-Print Network [OSTI]

    Schultz, Tanja

    , cough, etc. so­called human noises, or as nonarticulatory noises, like paper rustle, key click, door

  12. Calculation of Fire Severity Factors and Fire Non-Suppression Probabilities For A DOE Facility Fire PRA

    SciTech Connect (OSTI)

    Tom Elicson; Bentley Harwood; Jim Bouchard; Heather Lucek

    2011-03-01

    Over a 12 month period, a fire PRA was developed for a DOE facility using the NUREG/CR-6850 EPRI/NRC fire PRA methodology. The fire PRA modeling included calculation of fire severity factors (SFs) and fire non-suppression probabilities (PNS) for each safe shutdown (SSD) component considered in the fire PRA model. The SFs were developed by performing detailed fire modeling through a combination of CFAST fire zone model calculations and Latin Hypercube Sampling (LHS). Component damage times and automatic fire suppression system actuation times calculated in the CFAST LHS analyses were then input to a time-dependent model of fire non-suppression probability. The fire non-suppression probability model is based on the modeling approach outlined in NUREG/CR-6850 and is supplemented with plant specific data. This paper presents the methodology used in the DOE facility fire PRA for modeling fire-induced SSD component failures and includes discussions of modeling techniques for: • Development of time-dependent fire heat release rate profiles (required as input to CFAST), • Calculation of fire severity factors based on CFAST detailed fire modeling, and • Calculation of fire non-suppression probabilities.

  13. Linear noise approximation of noise-induced oscillation in NF-?B signaling network

    E-Print Network [OSTI]

    Jaewook Joo

    2010-10-08

    NF-{\\kappa}B, one of key regulators of inflammation, apoptosis, and differentiation, was found to have noisy oscillatory shuttling between the nucleus and the cytoplasm in single cells when cells are stimulated by cytokine TNF{\\alpha}. We present the analytical analysis which uncovers the underlying physical mechanisms of this spectacular noise-induced transition in biological networks. Starting with the master equation describing both signaling and transcription events in NF-{\\kappa}B signaling network, we derived the macroscopic and the Fokker-Planck equations by using van Kampen's sysem size expansion. Using the noise-induced oscillatory signatures present in the power spectrum, we constructed the two-dimensional phase diagram where the noise-induced oscillation emerges in the dynamically stable parameter space.

  14. Noise-driven informatics: secure classical communications via wire and noise-based computing

    E-Print Network [OSTI]

    Laszlo B. Kish

    2008-11-27

    In this paper, we show recent results indicating that using electrical noise as information carrier offers outstanding potentials reminding of quantum informatics. One example is noise-based computing and logic that shows certain similarities to quantum logic. However, due to the lack of the collapse of wavefunction and due to the immediate accessibility of superposition components, the use of noise-based and quantum computers will probably be different. Another example is secure communications where, out of the unconditional security at idealistic situations, a practical security beyond known quantum solutions can be achieved and has been demonstrated. Here the keys to security are the robustness of classical information, and the second law of thermodynamics. These offer the avoidance of making error statistics and single bit security. It has the potential to restrict the practical applications of quantum communicators to the situations where no wire can be used but optical communication via fiber or via space is possible.

  15. Prediction of noise impacts by the proposed Vienna Unit No. 9

    SciTech Connect (OSTI)

    Cwiklewski, M.

    1980-02-01

    Noise predictions are presented for a proposed 600 MWE expansion of a power plant at Vienna, Maryland. Topics include ambient noise, continuous and non-continuous plant noise sources, propagation of noise to off-site areas, annoyance potential, compliance with state noise regulation, and predictions of traffic noise from the proposed rerouting of an adjacent highway.

  16. Radar signal pre-processing to suppress surface bounce and multipath

    DOE Patents [OSTI]

    Paglieroni, David W; Mast, Jeffrey E; Beer, N. Reginald

    2013-12-31

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes that return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  17. Reactor Neutrino Flux Uncertainty Suppression on Multiple Detector Experiments

    E-Print Network [OSTI]

    Andi Cucoanes; Pau Novella; Anatael Cabrera; Muriel Fallot; Anthony Onillon; Michel Obolensky; Frederic Yermia

    2015-01-02

    This publication provides a coherent treatment for the reactor neutrino flux uncertainties suppression, specially focussed on the latest $\\theta_{13}$ measurement. The treatment starts with single detector in single reactor site, most relevant for all reactor experiments beyond $\\theta_{13}$. We demonstrate there is no trivial error cancellation, thus the flux systematic error can remain dominant even after the adoption of multi-detector configurations. However, three mechanisms for flux error suppression have been identified and calculated in the context of Double Chooz, Daya Bay and RENO sites. Our analysis computes the error {\\it suppression fraction} using simplified scenarios to maximise relative comparison among experiments. We have validated the only mechanism exploited so far by experiments to improve the precision of the published $\\theta_{13}$. The other two newly identified mechanisms could lead to total error flux cancellation under specific conditions and are expected to have major implications on the global $\\theta_{13}$ knowledge today. First, Double Chooz, in its final configuration, is the only experiment benefiting from a negligible reactor flux error due to a $\\sim$90\\% geometrical suppression. Second, Daya Bay and RENO could benefit from their partial geometrical cancellation, yielding a potential $\\sim$50\\% error suppression, thus significantly improving the global $\\theta_{13}$ precision today. And third, we illustrate the rationale behind further error suppression upon the exploitation of the inter-reactor error correlations, so far neglected. So, our publication is a key step forward in the context of high precision neutrino reactor experiments providing insight on the suppression of their intrinsic flux error uncertainty, thus affecting past and current experimental results, as well as the design of future experiments.

  18. Arsenite suppression of BMP signaling in human keratinocytes

    SciTech Connect (OSTI)

    Phillips, Marjorie A.; Qin, Qin [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States); Hu, Qin; Zhao, Bin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Rice, Robert H., E-mail: rhrice@ucdavis.edu [Department of Environmental Toxicology, University of California, Davis, CA 95616-8588 (United States)

    2013-06-15

    Arsenic, a human skin carcinogen, suppresses differentiation of cultured keratinocytes. Exploring the mechanism of this suppression revealed that BMP-6 greatly increased levels of mRNA for keratins 1 and 10, two of the earliest differentiation markers expressed, a process prevented by co-treatment with arsenite. BMP also stimulated, and arsenite suppressed, mRNA for FOXN1, an important transcription factor driving early keratinocyte differentiation. Keratin mRNAs increased slowly after BMP-6 addition, suggesting they are indirect transcriptional targets. Inhibition of Notch1 activation blocked BMP induction of keratins 1 and 10, while FOXN1 induction was largely unaffected. Supporting a requirement for Notch1 signaling in keratin induction, BMP increased levels of activated Notch1, which was blocked by arsenite. BMP also greatly decreased active ERK, while co-treatment with arsenite maintained active ERK. Inhibition of ERK signaling mimicked BMP by inducing keratin and FOXN1 mRNAs and by increasing active Notch1, effects blocked by arsenite. Of 6 dual-specificity phosphatases (DUSPs) targeting ERK, two were induced by BMP unless prevented by simultaneous exposure to arsenite and EGF. Knockdown of DUSP2 or DUSP14 using shRNAs greatly reduced FOXN1 and keratins 1 and 10 mRNA levels and their induction by BMP. Knockdown also decreased activated Notch1, keratin 1 and keratin 10 protein levels, both in the presence and absence of BMP. Thus, one of the earliest effects of BMP is induction of DUSPs, which increases FOXN1 transcription factor and activates Notch1, both required for keratin gene expression. Arsenite prevents this cascade by maintaining ERK signaling, at least in part by suppressing DUSP expression. - Highlights: • BMP induces FOXN1 transcription. • BMP induces DUSP2 and DUSP14, suppressing ERK activation. • Arsenite suppresses levels of phosphorylated Smad1/5 and FOXN1 and DUSP mRNA. • These actions rationalize arsenite suppression of keratinocyte differentiation.

  19. Ultrasensitive measurement of MEMS cantilever displacement sensitivity below the shot noise limit

    SciTech Connect (OSTI)

    Pooser, Raphael C; Lawrie, Benjamin J

    2015-01-01

    The displacement of micro-electro-mechanical-systems (MEMs) cantilevers is used to measure a variety of phe- nomena in devices ranging from force microscopes for single spin detection[1] to biochemical sensors[2] to un- cooled thermal imaging systems[3]. The displacement readout is often performed optically with segmented de- tectors or interference measurements. Until recently, var- ious noise sources have limited the minimum detectable displacement in MEMs systems, but it is now possible to minimize all other sources[4] so that the noise level of the coherent light eld, called the shot noise limit (SNL), becomes the dominant source. Light sources dis- playing quantum-enhanced statistics below this limit are available[5, 6], with applications in gravitational wave astronomy[7] and bioimaging[8], but direct displacement measurements of MEMS cantilevers below the SNL have been impossible until now. Here, we demonstrate the rst direct measurement of a MEMs cantilever displace- ment with sub-SNL sensitivity, thus enabling ultratrace sensing, imaging, and microscopy applications. By com- bining multi-spatial-mode quantum light sources with a simple dierential measurement, we show that sub-SNL MEMs displacement sensitivity is highly accessible com- pared to previous eorts that measured the displacement of macroscopic mirrors with very distinct spatial struc- tures crafted with multiple optical parametric ampliers and locking loops[9]. We apply this technique to a com- mercially available microcantilever in order to detect dis- placements 60% below the SNL at frequencies where the microcantilever is shot-noise-limited. These results sup- port a new class of quantum MEMS sensor whose ulti- mate signal to noise ratio is determined by the correla- tions possible in quantum optics systems.

  20. Stochastic storage models and noise-induced phase transitions

    E-Print Network [OSTI]

    Serge Shpyrko; V. V. Ryazanov

    2007-01-13

    The most frequently used in physical application diffusive (based on the Fokker-Planck equation) model leans upon the assumption of small jumps of a macroscopic variable for each given realization of the stochastic process. This imposes restrictions on the description of the phase transition problem where the system is to overcome some finite potential barrier, or systems with finite size where the fluctuations are comparable with the size of a system. We suggest a complementary stochastic description of physical systems based on the mathematical stochastic storage model with basic notions of random input and output into a system. It reproduces statistical distributions typical for noise-induced phase transitions (e.g. Verhulst model) for the simplest (up to linear) forms of the escape function. We consider a generalization of the stochastic model based on the series development of the kinetic potential. On the contrast to Gaussian processes in which the development in series over a small parameter characterizing the jump value is assumed [Stratonovich R.L., Nonlinear Nonequilibrium Thermodynamics, Springer Series in Synergetics, vol.59, Springer Verlag, 1994], we propose a series expansion directly suitable for storage models and introduce the kinetic potential generalizing them.