Powered by Deep Web Technologies
Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Evaluation of using active circuitry for substrate noise suppression  

Science Conference Proceedings (OSTI)

The performance of system-on-chips can be severely degraded if noisy circuits interfere with sensitive circuits through the common silicon substrate. Many methods have been proposed to suppress such substrate noise, ranging from designing circuits that ... Keywords: active noise decoupling, substrate coupling, substrate modeling

Rashid Farivar; Simon Kristiansson; Fredrik Ingvarson; Kjell O. Jeppson

2007-03-01T23:59:59.000Z

2

Unconditional quantum-noise suppression via measurement-based quantum feedback  

E-Print Network (OSTI)

We demonstrate unconditional quantum-noise suppression in a collective spin system via feedback control based on quantum non-demolition measurement (QNDM). We perform shot-noise limited collective spin measurements on an ensemble of $3.7\\times 10^5$ laser-cooled 171Yb atoms in their spin-1/2 ground states. Correlation between two sequential QNDMs indicates $-0.80^{+0.11}_{-0.12}\\,\\mathrm{dB}$ quantum noise suppression in a conditional manner. Our feedback control successfully converts the conditional quantum-noise suppression into the unconditional one without significant loss of the noise

Ryotaro Inoue; Shin-Ichi-Ro Tanaka; Ryo Namiki; Takahiro Sagawa; Yoshiro Takahashi

2013-01-06T23:59:59.000Z

3

Suppression of shot noise and spontaneous radiation in electron beams  

Science Conference Proceedings (OSTI)

Shot noise in the electron beam distribution is the main source of noise in high-gain FEL amplifiers, which may affect applications ranging from single- and multi-stage HGHG FELs to an FEL amplifier for coherent electron cooling. This noise also imposes a fundamental limit of about 10{sup 6} on FEL gain, after which SASE FELs saturate. There are several advantages in strongly suppressing this shot noise in the electron beam, and the corresponding spontaneous radiation. For more than a half-century, a traditional passive method has been used successfully in practical low-energy microwave electronic devices to suppress shot noise. Recently, it was proposed for this purpose in FELs. However, being passive, the method has some significant limitations and is hardly suitable for the highly inhomogeneous beams of modern high-gain FELs. I present a novel active method of suppressing, by many orders-of-magnitude, the shot noise in relativistic electron beams. I give a theoretical description of the process, and detail its fundamental limitation.

Litvinenko,V.

2009-08-23T23:59:59.000Z

4

Explosion suppression system  

DOE Patents (OSTI)

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.

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

1992-01-01T23:59:59.000Z

5

Pressure suppression containment system  

DOE Patents (OSTI)

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.

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

1994-03-15T23:59:59.000Z

6

Pressure suppression containment system  

DOE Patents (OSTI)

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.

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

1994-03-15T23:59:59.000Z

7

Wind noise suppression in cochlear implants with one and two microphones Student Investigator: Casey Cox  

E-Print Network (OSTI)

1 Wind noise suppression in cochlear implants with one and two microphones Student Investigator coding strategy used. However, performance deteriorates significantly in wind noise. Wind noise was to investigate how wind noise affects speech intelligibility in cochlear implant users. Default noise reduction

Peterson, Blake R.

8

Pressure suppression system  

DOE Patents (OSTI)

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.

Gluntz, Douglas M. (San Jose, CA)

1994-01-01T23:59:59.000Z

9

Blast Effects Suppression System  

The HydroSuppressor system was developed to protect critical facilities from the devastating effects of blast from a vehicle bomb.  HydroSuppressor ...

10

High Tc SQUID Circuits Suppress Intrinsic Magnetic Field Noise  

John Clarke and colleagues at Berkeley Lab have eliminated excess low frequency noise in high-transition temperature (Tc) superconducting quantum ...

11

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

Science Conference Proceedings (OSTI)

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.

Ratner, Daniel; Stupakov, Gennady; /SLAC

2012-06-19T23:59:59.000Z

12

Mechanism for the suppression of quantum noise at large scales on expanding space  

E-Print Network (OSTI)

We present an exactly-solvable model for the suppression of quantum noise at large scales on expanding space. The suppression arises naturally in the de Broglie-Bohm pilot-wave formulation of quantum theory, according to which the Born probability rule has a dynamical origin. For a scalar field on a radiation-dominated background we construct the exact solution for the time-evolving wave functional and study properties of the associated field trajectories. It is shown that the time evolution of a field mode on expanding space is mathematically equivalent to that of a standard harmonic oscillator with a 'retarded time' that depends on the wavelength of the mode. In the far super-Hubble regime the equivalent oscillator evolves over only one Hubble time, yielding a simple mechanism whereby relaxation to the Born rule can be suppressed on very large scales. We present numerical simulations illustrating how the expansion of space can cause a retardation of relaxation in the super-Hubble regime. Given these results it is natural to expect a suppression of quantum noise at super-Hubble wavelengths. Such suppression could have taken place in a pre-inflationary era, resulting in a large-scale power deficit in the cosmic microwave background.

Samuel Colin; Antony Valentini

2013-06-07T23:59:59.000Z

13

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

Science Conference Proceedings (OSTI)

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.

Wang Jing; Robar, James; Guan Huaiqun [Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas 75235 (United States); Departments of Radiation Oncology and Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H1V7 (Canada); Department of Radiation Oncology, Saint Vincent Hospital, Worcester, Massachusetts 01608 (United States)

2012-08-15T23:59:59.000Z

14

Mechanism for the suppression of quantum noise at large scales on expanding space  

E-Print Network (OSTI)

We present an exactly-solvable model for the suppression of quantum noise at large scales on expanding space. The suppression arises naturally in the de Broglie-Bohm pilot-wave formulation of quantum theory, according to which the Born probability rule has a dynamical origin. For a scalar field on a radiation-dominated background we construct the exact solution for the time-evolving wave functional and study properties of the associated field trajectories. It is shown that the time evolution of a field mode on expanding space is mathematically equivalent to that of a standard harmonic oscillator with a 'retarded time' that depends on the wavelength of the mode. In the far super-Hubble regime the equivalent oscillator evolves over only one Hubble time, yielding a simple mechanism whereby relaxation to the Born rule can be suppressed on very large scales. We present numerical simulations illustrating how the expansion of space can cause a retardation of relaxation in the super-Hubble regime. Given these results...

Colin, Samuel

2013-01-01T23:59:59.000Z

15

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

NLE Websites -- All DOE Office Websites (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...

16

Test results of lithium pool-air reaction suppression systems  

Science Conference Proceedings (OSTI)

Engineered reaction suppression systems were demonstrated to be effective in suppressing lithium pool-air reactions for lithium quantities up to 100 kg. Lithium pool-air reaction suppression system tests were conducted to evaluate suppression system effectiveness for potential use in fusion facilities in mitigating consequences of postulated lithium spills. Small-scale perforated and sacrificial cover plate suppression systems with delayed inert gas purging proved effective in controlling the lithium-air interaction for lithium quantities near 15 kg at initial temperatures up to 450/sup 0/C. A large-scale suppression system with a sacrificial cover, a diverter plate, an inert gas atmosphere, and remotely retrievable catch pans proved effective in controlling lithium pool-air interaction for a 100-kg lithium discharge at an initial temperature of 550/sup 0/C. This suppression system limited the maximum pool temperature to about 600/sup 0/C less than that expected for a similar lithium pool-air reaction without a suppression system. Lithium aerosol release from this large-scale suppression system was a factor of about 10,000 less than that expected for a lithium pool-air reaction with no suppression system. Remote retrieval techniques for lithium cleanup, such as (1) in-place lithium siphoning and overhead crane dismantling, and (2) lithium catch pan removal by use of an overhead crane, were demonstrated as part of this large-scale test.

Jeppson, D.W.

1987-02-01T23:59:59.000Z

17

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

NLE Websites -- All DOE Office Websites (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...

18

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

DOE Patents (OSTI)

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.

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

1993-12-28T23:59:59.000Z

19

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

DOE Patents (OSTI)

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.

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

1993-01-01T23:59:59.000Z

20

Phasor representation for narrowband active noise control systems  

Science Conference Proceedings (OSTI)

The phasor representation is introduced to identify the characteristic of the active noise control (ANC) systems. The conventional representation, transfer function, cannot explain the fact that the performance will be degraded at some frequency for ...

Fu-Kun Chen; Ding-Horng Chen; Yue-Dar Jou

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Noise Characterization of ATLAS Tile Calorimeter Readout System  

E-Print Network (OSTI)

Architect 3. Design noise filter Design noise filter circuit Simulate circuit using Design Architect 4

22

ENERGY DIFFUSION IN HARMONIC SYSTEM WITH CONSERVATIVE NOISE  

E-Print Network (OSTI)

ENERGY DIFFUSION IN HARMONIC SYSTEM WITH CONSERVATIVE NOISE GIADA BASILE AND STEFANO OLLA Abstract. We prove diffusive behaviour of the energy fluctua- tions in a system of harmonic oscillators with a stochastic pertur- bation of the dynamics that conserves energy and momentum. The results concern pinned

23

Revised noise criteria for design and rating of HVAC systems  

Science Conference Proceedings (OSTI)

This paper reviews current methods of rating the noise produced by HVAC systems and explains why these ratings fail to be correlated with subjective opinion in many cases. An entirely new method of assigning noise ratings is proposed which is expected to provide a significantly better correlation between objective measurements and subjective response. The proposed new rating method makes use of a revised set of noise criterion curves (RC curves) which appeared for the first time in Chap. 35 of the 1980 Systems Volume of the ASHRAE Handbook. This paper also discusses the technical considerations leading to the development of the RC curves as a replacement for the NC curves which have been used in the past.

Warren E. Blazier Jr.

1984-01-01T23:59:59.000Z

24

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

E-Print Network (OSTI)

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 ...

Kitchenka, Julie A

2004-01-01T23:59:59.000Z

25

Enabling Green Energy and Propulsion Systems via Direct Noise Computation |  

NLE Websites -- All DOE Office Websites (Extended Search)

High-fidelity simulation of exhaust nozzle under installed configuration High-fidelity simulation of exhaust nozzle under installed configuration 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 Email: paliath@ge.com Institution: GE Global Research Allocation Program: INCITE Allocation Hours at ALCF: 105 Million Year: 2013 Research Domain: Engineering GE Global Research is using the Argonne Leadership Computing Facility (ALCF) to deliver significant improvements in efficiency, (renewable's) yield and lower emissions (noise) for advanced energy and propulsion systems. Understanding the fundamental physics of turbulent mixing has the potential to transform product design for components such as airfoils and

26

Robust variance control for systems with finite-signal-to-noise uncertainty  

Science Conference Proceedings (OSTI)

This paper develops control analysis and synthesis techniques for systems with finite signal-to-noise-ratios (called the finite-signal-to-noise (FSN) models). The system is characterized by an easily computed measure @f. The control synthesis finds output ... Keywords: Optimal control, Robust control, Robust performance, Signal-to-noise ratio

Jianbo Lu; Robert E. Skelton

2000-04-01T23:59:59.000Z

27

Performance of Non-Polarized Noise Modulated Communications System in the Presence of Interference  

Science Conference Proceedings (OSTI)

The noise modulated non-polarized communication system, developed by us recently, is an ultra-wideband transmitted-reference system designed for secure interferencefree communications. By using ultra-wideband random noise to spread the signal and by ... Keywords: Interference, Noise modulation, Spread spectrum communication, Transmitted reference, Ultrawideband

Jack Chuang; Ram M. Narayanan

2012-08-01T23:59:59.000Z

28

Improved Turbulence Profiling with Field-Adapted Acoustic Doppler Velocimeters Using a Bifrequency Doppler Noise Suppression Method  

Science Conference Proceedings (OSTI)

A novel noise reduction method and corresponding technique are presented for improving turbulence measurements with acoustic Doppler velocimeters (ADVs) commonly used in field studies of coastal and nearshore regions, rivers, lakes, and ...

D. Hurther; U. Lemmin

2008-03-01T23:59:59.000Z

29

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

SciTech Connect

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.

Engelmann, Christian [ORNL

2013-01-01T23:59:59.000Z

30

Pulsed X-Band PM/AM Noise Measurement Systems  

Science Conference Proceedings (OSTI)

... the NIST Phase Noise Group has developed a second generation dual-channel ... approach uses a calibrated amount of offset signal power that can ...

2010-10-05T23:59:59.000Z

31

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

Science Conference Proceedings (OSTI)

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.

Bayramian, Andrew James (Manteca, CA)

2012-07-31T23:59:59.000Z

32

Suppression of dynamics in coupled discrete systems in interaction with an extended environment  

E-Print Network (OSTI)

We report the suppression of dynamics and occurrence of quiescent states in an extended system of coupled discrete dynamical systems. This phenomenon is induced by interaction with another similar system with a different and damped dynamics which we call an extended environment. Both the system and the environment are in a feedback loop and their mutual influence leads to suppression of dynamic activity. We illustrate this in the specific case of a system of coupled neurons modelled by a 2-dimensional discrete system called Rulkov maps. A detailed analysis is carried out by considering single units of discrete systems where control to steady states is induced by an external damped system. This is then extended to rings and lattices. As an important application, we also present how the excitation waves produced due to defect neurons can be suppressed by interaction with a system of passive cells.

Snehal M. Shekatkar; G. Ambika

2013-06-10T23:59:59.000Z

33

A quantitative evaluation of fixed-pattern noise reduction methods in imaging systems  

Science Conference Proceedings (OSTI)

Fixed-pattern noise is a common feature in several uncalibrated imaging systems, and it typically appears as striping and grid-like nonuniformity artifacts in hyperspectral and infrared cameras. In this work, we present a quantitative and comparative ...

Pablo Meza; César San Martin; Esteban Vera; Sergio Torres

2010-11-01T23:59:59.000Z

34

Noise Characterization of an Injection-Locked Titanium:sapphire Laser System  

E-Print Network (OSTI)

This thesis reports amplitude and frequency noise measurements of a Titanium:sapphire (Ti:sapphire) laser that is injection-locked with a low power diode laser. We use a heterodyne technique to frequency off-set lock a home built injection-locked Ti:sapphire laser with a low noise, commercial, injection-locked Ti:sapphire laser. Frequency noise measurements are made using the full-widthhalf-max of the two lasers ’ beat note. Amplitude noise measurements are made using the root mean square (rms) of the output of a photo diode. Under optimal conditions the rms amplitude noise is 1.0 % and the frequency noise is 300 kHz. The noise of our laser system depends on the feedback system characteristics. My contributions were the design and fabrication of a microwave interferometer, including its software and hardware, for the purpose of frequency off-set locking the two lasers. I also contributed to the data acquisition and analysis.

Daniel Adam Thrasher; Daniel Adam Thrasher

2013-01-01T23:59:59.000Z

35

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

Science Conference Proceedings (OSTI)

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.

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

2010-12-07T23:59:59.000Z

36

Comparison of Two Methods of Noise Power Spectrum Determinations of Medical Radiography Systems  

Science Conference Proceedings (OSTI)

Noise in medical images is recognized as an important factor that determines the image quality. Image noise is characterized by noise power spectrum (NPS). We compared two methods of NPS determination namely the methods of Wagner and Dobbins on Lanex Regular TMG screen-film system and Hologic Lorad Selenia full field digital mammography system, with the aim of choosing the better method to use. The methods differ in terms of various parametric choices and algorithm implementations. These parameters include the low pass filtering, low frequency filtering, windowing, smoothing, aperture correction, overlapping of region of interest (ROI), length of fast Fourier transform, ROI size, method of ROI normalization, and slice selection of the NPS. Overall, the two methods agreed to the practical value of noise power spectrum between 10{sup -3}-10{sup -6} mm{sup 2} over spatial frequency range 0-10 mm{sup -1}.

Hassan, Wan Muhamad Saridan Wan; Ahmed Darwish, Zeki [Department of Physics, Faculty of Science, University Teknologi Malaysia, 81310 UTM Skudai, Johor DT (Malaysia)

2011-03-30T23:59:59.000Z

37

Digital Filter Algorithm Based on Whistle Sound Suppression System Design  

Science Conference Proceedings (OSTI)

System uses the voice codec chip analog voice signals TLV320AIC23 A/D conversion, digital audio is passed to the DSP chip TMS320VC5409 sequence processing, DSP algorithms using FFT and CZT transform algorithm the number of sequences of audio spectrum ... Keywords: Acoustic feedback, FFT transform, CZT transform, IIR filter, TMS320VC5409

Lei Liu; Honggang Li; Xiaochen Hu

2012-08-01T23:59:59.000Z

38

New developments in noise control for HVAC systems.  

Science Conference Proceedings (OSTI)

The HVAC equipment industry is not known for rapid change. Although control systems have improved rapidly over the past few years

Timothy J. Foulkes

1996-01-01T23:59:59.000Z

39

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

Science Conference Proceedings (OSTI)

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.

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)

2010-08-17T23:59:59.000Z

40

Improved noise sensitivity under high-gain feedback in nano-positioning motion systems  

Science Conference Proceedings (OSTI)

To avoid an increased noise response under high-gain feedback in nano-positioning motion systems, a nonlinear (N-PID) control design is proposed. The design is of particular interest in the wafer scanning industry where nano-accuracy should be achieved ...

Marcel Heertjes; George Leenknegt; Bram Van Goch; Henk Nijmeijer

2009-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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

E-Print Network (OSTI)

How Quantum Computers Fail: Quantum Codes, Correlations in Physical Systems, and Noise Accumulation Dedicated to the memory of Itamar Pitowsky Abstract The feasibility of computationally superior quantum computers is one of the most exciting and clear-cut sci- entific questions of our time. The question touches

Kalai, Gil

42

Highly-efficient noise-assisted energy transport in classical oscillator systems  

E-Print Network (OSTI)

Photosynthesis is a biological process that involves the highly-efficient transport of energy captured from the sun to a reaction center, where conversion into useful biochemical energy takes place. Even though one can always use a quantum perspective to describe any physical process, since everything follows the laws of Quantum Mechanics, is the use of quantum theory imperative to explain this high efficiency? Several theoretical studies suggest that the high efficiency can only be understood as a result of the interplay between the quantum coherent evolution of the photosynthetic system, and noise introduced by its surrounding environment. Notwithstanding, we show here that noise-assisted highly-efficient energy transport can be found as well in purely classical systems; therefore, we might conclude that high efficiency energy transfer in photosynthetic systems could also be anticipated by classical models, without the need to resorting to quantum effects. Strikingly, the wider scope of applicability of the...

León-Montiel, R de J

2013-01-01T23:59:59.000Z

43

Highly-efficient noise-assisted energy transport in classical oscillator systems  

E-Print Network (OSTI)

Photosynthesis is a biological process that involves the highly-efficient transport of energy captured from the sun to a reaction center, where conversion into useful biochemical energy takes place. Even though one can always use a quantum perspective to describe any physical process, since everything follows the laws of Quantum Mechanics, is the use of quantum theory imperative to explain this high efficiency? Making use of the quantum-classical correspondence of electronic energy transfer recently introduced by Eisfeld and Briggs [Phys. Rev. E 85, 046118 (2012)], we show here that the highly-efficient noise-assisted energy transport described by Rebentrost et al. [New J. Phys. 11, 033003 (2009)], and Plenio and Huelga [New J. Phys. 10, 113019 (2008)], as the result of the interplay between the quantum coherent evolution of the photosynthetic system and noise introduced by its surrounding environment, it can be found as well in purely classical systems. The wider scope of applicability of the enhancement of energy transfer assisted by noise might open new ways for developing new technologies aimed at enhancing the efficiency of a myriad of energy transfer systems, from information channels in micro-electronic circuits to long-distance high-voltage electrical lines.

R. de J. León-Montiel; Juan P. Torres

2013-01-08T23:59:59.000Z

44

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

DOE Patents (OSTI)

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.

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)

2009-10-13T23:59:59.000Z

45

A Plan to Develop and Demonstrate Electrochemical Noise Based Corrosion Monitoring Systems in Hanford Site Waste Tanks  

SciTech Connect

This document describes changes that need to be made to the site's authorization basis and technical concerns that need to be resolved before proceduralized use of Electrochemical Noise based corrosion monitoring systems is fully possible at the Hanford Site.

NORMAN, E.C.

2000-08-28T23:59:59.000Z

46

Noise Thresholds for Higher Dimensional Systems using the Discrete Wigner Function  

E-Print Network (OSTI)

For a quantum computer acting on d-dimensional systems, we analyze the computational power of circuits wherein stabilizer operations are perfect and we allow access to imperfect non-stabilizer states or operations. If the noise rate affecting the non-stabilizer resource is sufficiently high, then these states and operations can become simulable in the sense of the Gottesman-Knill theorem, reducing the overall power of the circuit to no better than classical. In this paper we find the depolarizing noise rate at which this happens, and consequently the most robust non-stabilizer states and non-Clifford gates. In doing so, we make use of the discrete Wigner function and derive facets of the so-called qudit Clifford polytope i.e. the inequalities defining the convex hull of all qudit Clifford gates. Our results for robust states are provably optimal. For robust gates we find a critical noise rate that, as dimension increases, rapidly approaches the the theoretical optimum of 100%. Some connections with the question of qudit magic state distillation are discussed.

Wim van Dam; Mark Howard

2010-11-10T23:59:59.000Z

47

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

DOE Green Energy (OSTI)

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.

Huskey, A.

2011-11-01T23:59:59.000Z

48

Kalman filtering to suppress spurious signals in Adaptive Optics control  

SciTech Connect

In many scenarios, an Adaptive Optics (AO) control system operates in the presence of temporally non-white noise. We use a Kalman filter with a state space formulation that allows suppression of this colored noise, hence improving residual error over the case where the noise is assumed to be white. We demonstrate the effectiveness of this new filter in the case of the estimated Gemini Planet Imager tip-tilt environment, where there are both common-path and non-common path vibrations. We discuss how this same framework can also be used to suppress spatial aliasing during predictive wavefront control assuming frozen flow in a low-order AO system without a spatially filtered wavefront sensor, and present experimental measurements from Altair that clearly reveal these aliased components.

Poyneer, L; Veran, J P

2010-03-29T23:59:59.000Z

49

Performance analysis of multi-antenna OFDM systems with phase noise and imperfect channel estimation  

E-Print Network (OSTI)

?OFDM with Phase Noise (? 2 ? = 0.03 ) and ICE BER SNR in dB?OFDM with Phase Noise (? 2 ? = 0.03) and ICE BER SNR in dB?OFDM with Phase Noise (? 2 ? = 0.06) and ICE BER SNR in dB

Jalloh, Mohamed

2009-01-01T23:59:59.000Z

50

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

DOE Patents (OSTI)

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.

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

2006-08-08T23:59:59.000Z

51

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

DOE Patents (OSTI)

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.

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

2006-04-25T23:59:59.000Z

52

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

DOE Green Energy (OSTI)

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.

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

2009-01-01T23:59:59.000Z

53

Fire Suppression in Aircraft  

Science Conference Proceedings (OSTI)

... Imperial Japanese Navy Dry Bay and Ullage Fire Suppression System Concept ... Calibration Plot of Average Normalized Peak-to-valley Signals vs. ...

2011-12-27T23:59:59.000Z

54

Multivent effects in a large scale boiling water reactor pressure suppression system  

Science Conference Proceedings (OSTI)

The steam-driven GKSS pressure suppression test facility, which contains 3 full scale vent pipes, has been used for 5 years to investigate the postulated loss-of-coolant accident in a Mark II and Type 69 boiling water reactor. Using the results from several of these tests, wetwell boundary load data (peak pressures and spectral power) during the chugging stage, have been evaluated for sparse pool response (one and two vents in the three vent pool) and for full pool response (one, two, or three vent operation in pools of constant wetwell pool area per vent). The sparse pool results indicate the pool-system, chug event boundary loads are strongly dependent on wetwell pool area per vent, with the load increasing with decreasing area. The full pool results show a substantial increase in the pool-system, chug event boundary loads upon a change from single cell to double cell operation; only minor change occurs in going from double to triple cell operation.

McCauley, E.W.; Aust, E.; Schwan, H.

1984-07-06T23:59:59.000Z

55

Review of the Los Alamos National Laboratory Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System, January 2012  

NLE Websites -- All DOE Office Websites (Extended Search)

Waste Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

56

Review of the Los Alamos National Laboratory Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System, January 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Waste Waste Characterization, Reduction, and Repackaging Facility Fire Suppression System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

57

Review of the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System, January 2012  

NLE Websites -- All DOE Office Websites (Extended Search)

the the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

58

Review of the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System, January 2012  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

the the Los Alamos National Laboratory Chemistry and Metallurgy Research Facility Fire Suppression Vital Safety System January 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy i Table of Contents 1.0 Purpose ................................................................................................................................................... 1 2.0 Background ............................................................................................................................................ 1 3.0 Scope ...................................................................................................................................................... 1

59

Independent Oversight Review of the Technical Area 55 Safety Class Fire Suppression System at Los Alamos National Laboratory, December 2013  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Technical Area 55 Technical Area 55 Safety Class Fire Suppression System at Los Alamos National Laboratory December 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose .................................................................................................................................................... 1 2.0 Background ............................................................................................................................................. 1 3.0 Scope ....................................................................................................................................................... 2

60

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

DOE Patents (OSTI)

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.

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

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Noise Suppression and Spectral Decomposition for State-Dependent Noise  

E-Print Network (OSTI)

2 (Xk) + 2 (Xk) , (58) the sum of the variance of H(Xk) and the average variance of the added white the underlying state to fluctuate [J. M. G. Vilar and J. M. Rub´i, Phys. Rev. Lett. 86, 950 (2001)]. This paper conduction discussed in the original paper by Vilar and Rub´i. PACS numbers: 05.40.Ca, 05.45.Tp, 02.70.Hm

Walton, Brian

62

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

Science Conference Proceedings (OSTI)

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.

Huskey, A.; van Dam, J.

2010-11-01T23:59:59.000Z

63

Laboratory Evaluation of an Electrochemical Noise System for Detection of Localized and General Corrosion of Natural Gas Transmission Pipelines  

SciTech Connect

Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous solutions typical of those found within gas pipelines in equilibrium with th e corrosive components of natural gas; (2) biologically-active soils typical of wetlands; and (3) a simulated, unpressurized, internal gas/liquid gas pipeline environment. Multiple sensor designs were evaluated in the simulated pipe environment. Gravimetric measurements were conducted in parallel with the electrochemical noise measurements to validate the results.

Bullard, S.J.; Covino, B.S., Jr.; Russell, J.H.; Holcomb, G.R.; Cramer, S.D.; Ziomek-Moroz, M.; Eden, D.

2003-03-16T23:59:59.000Z

64

W-band Frequency Synthesis and AM/PM Noise ...  

Science Conference Proceedings (OSTI)

... W-band Frequency Synthesis and AM/PM Noise Measurement System. ... Dual-channel W-band AM/PM noise measurement system. ...

2010-10-05T23:59:59.000Z

65

Performance analysis of multi-antenna OFDM systems with phase noise and imperfect channel estimation  

E-Print Network (OSTI)

of frequency division duplex FDD transmission systems usingStandards Institute FDMA FDD FEC FFT FLASH-OFDM Frequencyfrequency division duplex (FDD) and time division duplex (

Jalloh, Mohamed

2009-01-01T23:59:59.000Z

66

An Initial Study on Applying Active Noise Control to an Insulated Box Fan Used in Ventilation System Applications.  

E-Print Network (OSTI)

??In many different applications and buildings fans are used to remove unwanted and used air. These fans often generate broadband and tonal noise. Commonly, passive… (more)

Larsson, Martin; Johansson, Sven; Muddala, S.M.; Gafar, A.E.; Håkansson, Lars; Tarkka, Juhani

2009-01-01T23:59:59.000Z

67

Substrate noise analysis and techniques for mitigation in mixed-signal RF systems  

E-Print Network (OSTI)

Mixed-signal circuit design has historically been a challenge for several reasons. Parasitic interactions between analog and digital systems on a single die are one such challenge. Switching transients induced by digital ...

Checka, Nisha, 1980-

2005-01-01T23:59:59.000Z

68

NIST Johnson noise thermometry  

Science Conference Proceedings (OSTI)

... noise thermometry (JNT) is a primary temperature measurement ... and-or other thermal noise sources. ... Quantized Voltage Noise Source (QVNS) (see ...

2011-10-18T23:59:59.000Z

69

Quantum noise in photothermal cooling  

SciTech Connect

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.

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)

2011-03-15T23:59:59.000Z

70

Attenuating Plant Noise: Active Noise Control Helmholtz Resonator Demonstration: Low Frequency Noise Mitigation  

Science Conference Proceedings (OSTI)

This report describes the implementation of the active Helmholtz resonator concept at a Midwestern power plant to suppress low frequency noise emitted from three simple-cycle, combustion turbine peaking units. The units normally operate during the summer season and only when electricity demand is very high (e.g., during periods with high ambient temperatures). However, when one or more of the units are dispatched, the plant sometimes receives complaints from the residential development located approximat...

2004-03-23T23:59:59.000Z

71

Suppressant: Metal Containing Compounds  

Science Conference Proceedings (OSTI)

... for Suppression of Fuel Spray Explosions in Military Vehicle Crew Compartments.. ... Study of Water Mist Suppression of Electrical Fires for ...

2013-04-25T23:59:59.000Z

72

Fire Suppression Systems  

Science Conference Proceedings (OSTI)

... docks and an electrical substation that provided ... pump, located on the ground floor, supplied ... sizes under “normally expected” operating conditions. ...

73

Quantum control with noisy fields: computational complexity vs. sensitivity to noise  

E-Print Network (OSTI)

A closed quantum system is defined as completely controllable if an arbitrary unitary transformation can be executed using the available controls. In practice, control fields are a source of unavoidable noise, which has to be suppressed to retain controllability. Can one design control fields such that the effect of noise is negligible on the time-scale of the transformation? This question is intimately related to the fundamental problem of a connection between the computational complexity of the control problem and the sensitivity of the controlled system to noise. The present study considers a paradigm of control, where the Lie-algebraic structure of the control Hamiltonian is fixed, while the size of the system increases with the dimension of the Hilbert space representation of the algebra. We find two types of control tasks, easy and hard. Easy tasks are characterized by a small variance of the evolving state with respect to the operators of the control operators. They are relatively immune to noise and the control field is easy to find. Hard tasks have a large variance, are sensitive to noise and the control field is hard to find. The influence of noise increases with the size of the system, which is measured by the scaling factor $N$ of the largest weight of the representation. For fixed time and control field as O(N) for easy tasks and as $O(N^2)$ for hard tasks. As a consequence, even in the most favorable estimate, for large quantum systems, generic noise in the controls dominates for a typical class of target transformations, i.e., complete controllability is destroyed by noise.

S. Kallush; M. Khasin; R. Kosloff

2013-08-28T23:59:59.000Z

74

Independent Oversight Review of the Fire Protection Program at the Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory, September 2013  

NLE Websites -- All DOE Office Websites (Extended Search)

Independent Oversight Review of the Independent Oversight Review of the Fire Protection Program at Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory May 2011 February 2013 September 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose.................................................................................................................................................... 1 2.0 Background ............................................................................................................................................. 1 3.0 Scope....................................................................................................................................................... 2

75

Independent Oversight Review of the Fire Protection Program at the Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory, September 2013  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Independent Oversight Review of the Independent Oversight Review of the Fire Protection Program at Pacific Northwest National Laboratory and the Fire Suppression System at the Radiochemical Processing Laboratory May 2011 February 2013 September 2013 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose.................................................................................................................................................... 1 2.0 Background ............................................................................................................................................. 1 3.0 Scope....................................................................................................................................................... 2

76

Agriculture - Noise and shocking investigation  

Science Conference Proceedings (OSTI)

This power quality (PQ) case study presents an investigation of noise and shocking from the telephone line at a horse farm. The investigation revealed that the noise was caused by an arching connection and vegetation along the fence. Also the charger's grounding system was not installed properly. Recommendations were made to the customer to reinstall the charger's ground system to manufacturer's specification and use an AM radio to find the loose connection along the fence.

2003-12-31T23:59:59.000Z

77

Noise-control needs in the developing energy technologies  

DOE Green Energy (OSTI)

The noise characteristics of existing energy conversion technologies, e.g., from obtaining and processing fossil fuels to power plants operations, and of developing energy technologies (wind, geothermal sources, solar energy or fusion systems) are discussed in terms of the effects of noise on humans, animals, structures, and equipment and methods for noise control. Regulations for noise control are described. Recommendations are made for further research on noise control and noise effects. (LCL)

Keast, D.N.

1978-03-01T23:59:59.000Z

78

Active Noise Control of a Radial Fan.  

E-Print Network (OSTI)

??This thesis work aims at investigating the use of an active noise control (ANC) system on a radial fan. This was done by studying the… (more)

Murthy, Muddala

2009-01-01T23:59:59.000Z

79

Noise and Hearing Conservation  

NLE Websites -- All DOE Office Websites (Extended Search)

Hearing Conservation Hearing Conservation Mary L. Doyle NOISE & HEARING CONSERVATION Mary L. Doyle, MPH, RN, COHN-S/CM DOE Headquarters January 16, 2002 1.0.1.~ CAUSES OF HEARING LOSS * Congenital * Environmental Exposures * Hereditary * Illness *Injury * Noise * Occupational * Non-Occupational * Sociacusis S.O.S. eon.ua.nt. OTOTOXIC DRUGS Can Affect Cochlea or Vestibular System * Aminoglycoside Antibiotics * Diuretics * Cancer Chemotherapy * Aspirin * Quinines * Usually Permanent * Consider Benefit-Risk Ratio S.O.S. eon.ua.nts HEARING * Modification of Acoustic Wave by Outer Ear * Conversion of Modified Acoustic Wave to Vibration of Eardrum * Middle Ear * Inner Ear * Transformation of Mechanical Movement to Nerve Impulses S.O.S. CoMubRis OTOTOXIC INDUSTRIAL

80

Simulation and Theory of Speckle Noise for an Annular Aperture Frequency-Modulation Differential-Absorption LIDAR (FM-DIAL) System  

Science Conference Proceedings (OSTI)

This paper presents theory of speckle noise for a frequency-modulation differential-absorption LIDAR system along with simulation results. These results show an unexpected relationship between the signal-to-noise ratio (SNR) of the speckle and the distance to the retro-reflector or target. In simulation, the use of an annular aperture in the system results in a higher SNR at midrange distances than at short or long distances. This peak in SNR occurs in the region where the laser’s Gaussian beam profile approximately fills the target. This was unexpected since it does not occur in the theory or simulations of the same system with a circular aperture. By including the autocorrelation of this annular aperture and expanding the complex correlation factor used in speckle models to include conditions not generally covered, a more complete theoretical model is derived for this system. Obscuration of the center of the beam at near distances is also a major factor in this relationship between SNR and distance. We conclude by comparing the resulting SNR as a function of distance from this expanded theoretical model to the simulations of the system over a double-pass horizontal range of 10 meters to 10 km at a wavelength of 1.28 micrometers

Keller, Paul E.; Batdorf, Michael T.; Strasburg, Jana D.; Harper, Warren W.

2009-05-28T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

SOLAR RADIO TYPE-I NOISE STORM MODULATED BY CORONAL MASS EJECTIONS  

SciTech Connect

The first coordinated observations of an active region using ground-based radio telescopes and the Solar Terrestrial Relations Observatory (STEREO) satellites from different heliocentric longitudes were performed to study solar radio type-I noise storms. A type-I noise storm was observed between 100 and 300 MHz during a period from 2010 February 6 to 7. During this period the two STEREO satellites were located approximately 65 Degree-Sign (ahead) and -70 Degree-Sign (behind) from the Sun-Earth line, which is well suited to observe the earthward propagating coronal mass ejections (CMEs). The radio flux of the type-I noise storm was enhanced after the preceding CME and began to decrease before the subsequent CME. This time variation of the type-I noise storm was directly related to the change of the particle acceleration processes around its source region. Potential-field source-surface extrapolation from the Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) magnetograms suggested that there was a multipolar magnetic system around the active region from which the CMEs occurred around the magnetic neutral line of the system. From our observational results, we suggest that the type-I noise storm was activated at a side-lobe reconnection region that was formed after eruption of the preceding CME. This magnetic structure was deformed by a loop expansion that led to the subsequent CME, which then suppressed the radio burst emission.

Iwai, K.; Tsuchiya, F.; Morioka, A.; Misawa, H. [Planetary Plasma and Atmospheric Research Center, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Miyoshi, Y.; Masuda, S. [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi 464-8601 (Japan); Shimojo, M. [Nobeyama Solar Radio Observatory, Nobeyama, Nagano 384-1305 (Japan); Shiota, D. [Advanced Science Institute, RIKEN (Institute of Physics and Chemical Research), Wako, Saitama 351-0198 (Japan); Inoue, S., E-mail: kazumasa-iwai@pparc.gp.tohoku.ac.jp [National Institute of Information and Communications Technology, Koganei, Tokyo 184-0015 (Japan)

2012-01-10T23:59:59.000Z

82

Noise-enhanced trapping in chaotic scattering  

E-Print Network (OSTI)

We show that noise enhances the trapping of trajectories in scattering systems. In fully chaotic systems, the decay rate can decrease with increasing noise due to a generic mismatch between the noiseless escape rate and the value predicted by the Liouville measure of the exit set. In Hamiltonian systems with mixed phase space we show that noise leads to a slower algebraic decay due to trajectories performing a random walk inside Kolmogorov-Arnold-Moser islands. We argue that these noise-enhanced trapping mechanisms exist in most scattering systems and are likely to be dominant for small noise intensities, which is confirmed through a detailed investigation in the Henon map. Our results can be tested in fluid experiments, affect the fractal Weyl's law of quantum systems, and modify the estimations of chemical reaction rates based on phase-space transition state theory.

Altmann, Eduardo G; 10.1103/PhysRevLett.105.244102

2010-01-01T23:59:59.000Z

83

Suppressant: Electric Fields  

Science Conference Proceedings (OSTI)

*. Bookmark and Share. Suppressant:Electric Fields. Fire Extinguishment of Pool Flames by Means of a DC electric Field.. ...

2011-11-04T23:59:59.000Z

84

Ocean shell noises  

NLE Websites -- All DOE Office Websites (Extended Search)

Ocean shell noises Name: Rick A Cazzato Location: NA Country: NA Date: NA Question: Why do you here noises when you put a ocean shell to your ear? Does this happen because of...

85

Polarimetric Spectral Filter for Adaptive Clutter and Noise Suppression  

Science Conference Proceedings (OSTI)

In this paper, spectral decompositions of differential reflectivity, differential phase, and copolar correlation coefficient are used to discriminate between weather and nonweather signals in the spectral domain. This approach gives a greater ...

Dmitri N. Moisseev; V. Chandrasekar

2009-02-01T23:59:59.000Z

86

Noise Pollution Control (Minnesota) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Noise Pollution Control (Minnesota) Noise Pollution Control (Minnesota) Noise Pollution Control (Minnesota) < Back Eligibility Utility Fed. Government Commercial Agricultural Investor-Owned Utility State/Provincial Govt Industrial Construction Municipal/Public Utility Local Government Residential Installer/Contractor Rural Electric Cooperative Tribal Government Low-Income Residential Schools Retail Supplier Institutional Multi-Family Residential Systems Integrator Fuel Distributor Nonprofit General Public/Consumer Transportation Savings Category Alternative Fuel Vehicles Hydrogen & Fuel Cells Buying & Making Electricity Water Home Weatherization Solar Wind Program Info State Minnesota Program Type Environmental Regulations These regulations set noise standards and direct municipalities to take reasonable measures to prevent the establishment of land use activities

87

Active noise control: A tutorial for HVAC designers  

Science Conference Proceedings (OSTI)

This article will identify the capabilities and limitations of ANC in its application to HVAC noise control. ANC can be used in ducted HVAC systems to cancel ductborne, low-frequency fan noise by injecting sound waves of equal amplitude and opposite phase into an air duct, as close as possible to the source of the unwanted noise. Destructive interference of the fan noise and injected noise results in sound cancellation. The noise problems that it solves are typically described as rumble, roar or throb, all of which are difficult to address using traditional noise control methods. This article will also contrast the use of active against passive noise control techniques. The main differences between the two noise control measures are acoustic performance, energy consumption, and design flexibility. The article will first present the fundamentals and basic physics of ANC. The application to real HVAC systems will follow.

Gelin, L.J.

1997-08-01T23:59:59.000Z

88

Atomic clocks with suppressed blackbody radiation shift  

E-Print Network (OSTI)

We develop a nonstandard concept of atomic clocks where the blackbody radiation shift (BBRS) and its temperature fluctuations can be dramatically suppressed (by one to three orders of magnitude) independent of the environmental temperature. The suppression is based on the fact that in a system with two accessible clock transitions (with frequencies $\

Yudin, V I; Okhapkin, M V; Bagayev, S N; Tamm, Chr; Peik, E; Huntemann, N; Mehlstaubler, T E; Riehle, F

2011-01-01T23:59:59.000Z

89

Underwater radiated noise measurements of a noise?reduced research vessel: Comparison between a U.S. Navy noise range and a simple hydrophone mooring.  

Science Conference Proceedings (OSTI)

[A feasibility study was undertaken to characterize underwater radiated noise for a new class of noise?reduced fisheries research vessels using a field?deployable hydrophone system. Recent studies have demonstrated that vessel?radiated noise can impact the behavior of fish

Alex De Robertis; Christopher D. Wilson; Peter H. Dahl

2011-01-01T23:59:59.000Z

90

Underwater radiated noise measurements of a noise-reduced research vessel: comparison between a US Navy noise range and a simple hydrophone mooring.  

Science Conference Proceedings (OSTI)

A feasibility study was undertaken to characterize underwater radiated noise for a new class of noise-reduced fisheries research vessels using a field-deployable hydrophone system. Recent studies have demonstrated that vessel-radiated noise can impact the behavior of fish

Alex De Robertis; Christopher Wilson

2014-01-01T23:59:59.000Z

91

Optimal control of quantum gates and suppression of decoherence in a system of interacting two-level particles  

E-Print Network (OSTI)

Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental effect of decoherence. One set of particles functions as the quantum information processor, whose evolution is controlled by a time-dependent external field. The other particles are not directly controlled and serve as an effective environment, coupling to which is the source of decoherence. The control objective is to generate target one- and two-qubit unitary gates in the presence of strong environmentally-induced decoherence and under physically motivated restrictions on the control field. The quantum-gate fidelity, expressed in terms of a novel state-independent distance measure, is maximized with respect to the control field using combined genetic and gradient algorithms. The resulting high-fidelity gates demonstrate the feasibility of precisely guiding the quantum evolution via optimal control, even when the system complexity is exacerbated by environmental coupling. It is found that the gate duration has an important effect on the control mechanism and resulting fidelity. An analysis of the sensitivity of the gate performance to random variations in the system parameters reveals a significant degree of robustness attained by the optimal control solutions.

Matthew Grace; Constantin Brif; Herschel Rabitz; Ian A. Walmsley; Robert L. Kosut; Daniel A. Lidar

2007-02-14T23:59:59.000Z

92

Thermal Noise Metrology  

Science Conference Proceedings (OSTI)

... of a one-port source and the ... from 8.2 gigahertz to 65 gigahertz for waveguide sources. ... remote-sensing measurements to primary noise standards. ...

2011-09-27T23:59:59.000Z

93

A noise rejection deadbeat control technique for active power filter  

Science Conference Proceedings (OSTI)

Compared with power filter, active power filter has a lot of advantages and it is an efficient technique to eliminate or limit the harmonic pollution in power system. However, the control of active power filter is very complex, and the control of current ... Keywords: active power filter, current control technique, deadbeat control, noise rejection, periodic noise, resetting integrator, sampling noise

Li-Dan Zhou; Mansoor Mansoor; Qian Ai; Da Xie; Chen Chen

2005-10-01T23:59:59.000Z

94

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

SciTech Connect

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.

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

2011-09-01T23:59:59.000Z

95

Optomechanical entanglement in the presence of laser phase noise  

SciTech Connect

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.

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)

2011-12-15T23:59:59.000Z

96

Low noise control valve  

SciTech Connect

Noise is one of the problems associated with the use of any type of control valve in systems involving the flow of fluids. The advent of OSHA standards has prompted control valve manufacturers to design valves with special trim to lower the sound pressure level to meet these standards. However, these levels are in some cases too high, particularly when a valve must be located in or near an area where people are working at tasks requiring a high degree of concentration. Such locations are found around and near research devices and in laboratory-office areas. This paper describes a type of fluid control device presently being used at PPL as a bypass control valve in deionized water systems and designed to reduce sound pressure levels considerably below OSHA standards. Details of the design and construction of this constant pressure drop variable flow control valve are contained in the text and are shown in photographs and drawings. Test data taken are included. (auth)

Christie, R.S.

1975-01-01T23:59:59.000Z

97

Noise from cooling towers of power parks  

SciTech Connect

A study is presented of the noise pollution problem for large power parks proposed for the future. Such parks might have an area of about 75 sq. miles, and a generating capacity up to 48000 MW. A comparative analysis has been done for natural and mechanical-draft wet towers as the major sources of acoustic power. Noise radiation from single isolated towers as well as from a dispersed array of towers has been considered for both types of cooling systems. Major noise attenuation effects considered are due to the atmospheric absorption and A- weighting. Conditions of 60F and 70 percent relative humidity in a still atmosphere have been assumed. (auth)

Zakaria, J.; Moore, F.K.

1975-10-14T23:59:59.000Z

98

Rotor Noise in Maneuvering Flight.  

E-Print Network (OSTI)

??The objective of this research is to understand the physics of rotor noise in the maneuvering flight. To achieve this objective, an integrated noise prediction… (more)

Chen, Hsuan-nien

2006-01-01T23:59:59.000Z

99

Predict flare noise and spectrum  

Science Conference Proceedings (OSTI)

Predicting flare combustion noise is important to ensure the flare is a certain distance from inhabited areas. Generally, it not feasible to increase the stack height to lower the overall noise at a particular point. This article shows how to calculate flare noise including spectrum considerations. Depending on the spectrum, a lower power noise source may sound louder than a higher power source.

Leite, O.C. (Pilgrim Steel Co., Glassboro, NJ (US))

1988-12-01T23:59:59.000Z

100

Noise-assisted energy transfer in quantum networks and light-harvesting complexes  

E-Print Network (OSTI)

We provide physically intuitive mechanisms for the effect of noise on excitation energy transfer (EET) in networks. Using these mechanisms of dephasing-assisted transport (DAT) in a hybrid basis of both excitons and sites, we shed new light on how noise enables energy transfer with efficiencies well above 90% across light harvesting molecules, like the Fenna-Matthew-Olson (FMO) complex. We demonstrate explicitly how noise alters the pathways of energy transfer across the complex, suppressing ineffective pathways and facilitating direct ones to the reaction centre. This understanding opens up a new paradigm of `noise-engineering' by which EET can be optimized in artificial light-harvesting structures.

Chin, Alex W; Caruso, Filippo; Huelga, Susana F; Plenio, Martin B

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

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)

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

Sóbester, András

102

White Noise Theory  

E-Print Network (OSTI)

white noise space 3.2 Wick tensors 3.3 Hida-Kubo-Takenaka space 3.4 Kondratiev-Streit space 3.5 Cochran-Kuo-Sengupta space 4. Continuous versions and analytic extensions 4.1 Continuous versions 4.2 Analytic extensions 4.3 Integrable functions 4.4 Generalized functions induced by measures 4.5 Generalized Radon-Nikodym derivative 5. Characterization theorems 5.1 The S-transform 5.2 Characterization of generalized functions 5.3 Convergence of generalized functions 5.4 Characterization of test functions 5.5 Intrinsic topology for the space of test functions 6. Continuous operators and adjoints 6.1 Differential operators 6.2 Translation and scaling operators 6.3 Multiplication and Wick product 6.4 Fourier-Gauss transform 6.5 Extensions to CKS-spaces 7. Comments on other topics and applications 1 2 HUI-HSIUNG KUO 1. Introduction x1.1 What is white noise? White noise is a sound with equal intensity at all frequencies within a broad band. Rock music, the roar of a jet engine, and the noise...

Hui-Hsiung Kuo

1999-01-01T23:59:59.000Z

103

Suppressant:Water & Aqueous Solutions  

Science Conference Proceedings (OSTI)

Suppressant:Water & Aqueous Solutions. ... Reuther, JJ; 1991. Fine Water Sprays for Fire Protection: A Halon Replacement Option.. ...

2011-10-28T23:59:59.000Z

104

Thermal Noise Metrology Project Talks  

Science Conference Proceedings (OSTI)

... "Simulations of Noise-Parameter Uncertainties," (1.5 MB) J. Randa, International Microwave Symposium, Seattle, June 2002. ...

2010-10-05T23:59:59.000Z

105

Noise modeling from high-permeability shields using Kirchhoff equations  

SciTech Connect

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.

Sandin, Henrik J [Los Alamos National Laboratory; Volegov, Petr L [Los Alamos National Laboratory; Espy, Michelle A [Los Alamos National Laboratory; Matlashov, Andrei N [Los Alamos National Laboratory; Savukov, Igor M [Los Alamos National Laboratory; Schultz, Larry J [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

106

Optical Johnson noise thermometry  

DOE Patents (OSTI)

This invention is a 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. 2 figs.

Shepard, R.L.; Blalock, T.V.; Roberts, M.J.

1989-01-30T23:59:59.000Z

107

Quantum noises and the large scale structure  

E-Print Network (OSTI)

We propose that cosmological density perturbation may originate from passive fluctuations of the inflaton, which are induced by colored quantum noise due to the coupling of the inflaton to the quantum environment. At small scales, the fluctuations grow with time to become nearly scale-invariant. However, the larger-scale modes cross out the horizon earlier and do not have enough time to grow, thus resulting in a suppression of the density perturbation. This may explain the observed low quadrupole in the CMB anisotropy data and and potentially unveil the initial time of inflation. We also discuss the implications to the running spectral index and the non-Gaussianity of the primordial density perturbation.

Wo-Lung Lee

2007-01-31T23:59:59.000Z

108

Imaging with ambient noise  

Science Conference Proceedings (OSTI)

Recent developments in seismology, ultrasonics, and underwater acoustics have led to a radical change in the way scientists think about ambient noise--the diffuse waves generated by pressure fluctuations in the atmosphere, the scattering of water waves in the ocean, and any number of other sources that pervade our world. Because diffuse waves consist of the superposition of waves propagating in all directions, they appear to be chaotic and random. That appearance notwithstanding, diffuse waves carry information about the medium through which they propagate.

Snieder, Roel; Wapenaar, Kees [Colorado School of Mines, Golden (United States); Delft University of Technology, Delft (Netherlands)

2010-09-15T23:59:59.000Z

109

ZERO SUPPRESSION FOR RECORDERS  

DOE Patents (OSTI)

A zero-suppression circuit for self-balancing recorder instruments is presented. The essential elements of the circuit include a converter-amplifier having two inputs, one for a reference voltage and the other for the signal voltage under analysis, and a servomotor with two control windings, one coupled to the a-c output of the converter-amplifier and the other receiving a reference input. Each input circuit to the converter-amplifier has a variable potentiometer and the sliders of the potentiometer are ganged together for movement by the servoinotor. The particular noveity of the circuit resides in the selection of resistance values for the potentiometer and a resistor in series with the potentiometer of the signal circuit to ensure the full value of signal voltage variation is impressed on a recorder mechanism driven by servomotor.

Fort, W.G.S.

1958-12-30T23:59:59.000Z

110

Holographic Noise in Interferometers  

E-Print Network (OSTI)

Arguments based on general principles of quantum mechanics suggest that a minimum length or time associated with Planck-scale unification may entail a new kind of observable uncertainty in the transverse position of macroscopically separated bodies. Transverse positions vary randomly about classical geodesics in space and time by about the geometric mean of the Planck scale and separation, on a timescale corresponding to their separation. An effective theory based on a Planck information flux limit, and normalized by the black hole entropy formula, is developed to predict measurable correlations, such as the statistical properties of noise in interferometer signals. A connection with holographic unification is illustrated by representing Matrix theory position operators with a Schr\\"odinger wave equation, interpreted as a paraxial wave equation with a Planck frequency carrier. Solutions of this equation are used to derive formulas for the spectrum of beamsplitter position fluctuations and equivalent strain noise in a Michelson interferometer, determined by the Planck time, with no other parameters. The spectral amplitude of equivalent strain derived here is a factor of \\sqrt{\\pi} smaller than previously published estimates. Signals in two nearly-collocated interferometers are predicted to be highly correlated, a feature that may provide convincing evidence for or against this interpretation of holography.

Craig J. Hogan

2009-05-29T23:59:59.000Z

111

Low-noise SQUID  

DOE Patents (OSTI)

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.

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

2000-01-01T23:59:59.000Z

112

High level white noise generator  

DOE Patents (OSTI)

A wide band, stable, random noise source with a high and well-defined output power spectral density is provided which may be used for accurate calibration of Johnson Noise Power Thermometers (JNPT) and other applications requiring a stable, wide band, well-defined noise power spectral density. The noise source is based on the fact that the open-circuit thermal noise voltage of a feedback resistor, connecting the output to the input of a special inverting amplifier, is available at the amplifier output from an equivalent low output impedance caused by the feedback mechanism. The noise power spectral density level at the noise source output is equivalent to the density of the open-circuit thermal noise or a 100 ohm resistor at a temperature of approximately 64,000 Kelvins. The noise source has an output power spectral density that is flat to within 0.1% (0.0043 db) in the frequency range of from 1 KHz to 100 KHz which brackets typical passbands of the signal-processing channels of JNPT's. Two embodiments, one of higher accuracy that is suitable for use as a standards instrument and another that is particularly adapted for ambient temperature operation, are illustrated in this application.

Borkowski, Casimer J. (Oak Ridge, TN); Blalock, Theron V. (Knoxville, TN)

1979-01-01T23:59:59.000Z

113

Phase and Amplitude Noise Measurements  

Science Conference Proceedings (OSTI)

... 1/f, “flicker” behavior, which often significantly dominates over the white-noise level ... A paper published by Archita Hati and others addresses two ...

2010-10-05T23:59:59.000Z

114

Classroom auralizations using both speech and intruding noise  

Science Conference Proceedings (OSTI)

Continuing work with computer auralizations for education spaces—Can realistic speech auralizations be obtained for classrooms and similar spaces with disturbing ambient noise as produced by HVAC systems

2005-01-01T23:59:59.000Z

115

Shipping source level estimation for ambient noise forecasting  

Science Conference Proceedings (OSTI)

The ability to accurately estimate shipping source levels from ambient noise data is an essential step towards creating a forecast model of the ocean soundscape. Source level estimates can be obtained by solving the system of linear equations

Jeffrey S. Rogers; Steven L. Means; Stephen C. Wales

2012-01-01T23:59:59.000Z

116

Holographic Noise in Interferometers  

E-Print Network (OSTI)

General arguments based on black hole physics suggest the possibility of a new kind of indeterminacy in the relative position of bodies in spacetime, corresponding to the diffraction limit of Planck wavelength radiation. Suitably designed instruments should display a new phenomenon, a randomly varying shear in relative position, with a flat power spectral density at low frequencies given approximately by the Planck time, and with no other parameters. An effective theory is presented to connect fundamental theory with macroscopic phenomena, such as the statistical properties of noise in signals of interferometers. A theory of spacetime wavefunctions based on the paraxial wave equation with a carrier wave at the Planck frequency, or equivalently a Schrodinger wave equation, is motivated by a particular interpretation of Matrix theory in the macroscopic limit. A model based on gaussian-beam solutions of this equation is used to derive formulas in the time and frequency domain for autocorrelation of beamsplitter ...

Hogan, Craig J

2009-01-01T23:59:59.000Z

117

Impedance Noise Identification for State-of-Health Prognostics  

DOE Green Energy (OSTI)

Impedance Noise Identification is an in-situ method of measuring battery impedance as a function of frequency using a random small signal noise excitation source. Through a series of auto- and cross-correlations and Fast Fourier Transforms, the battery complex impedance as a function of frequency can be determined. The results are similar to those measured under a lab-scale electrochemical impedance spectroscopy measurement. The lab-scale measurements have been shown to correlate well with resistance and power data that are typically used to ascertain the remaining life of a battery. To this end, the Impedance Noise Identification system is designed to acquire the same type of data as an on-board tool. A prototype system is now under development, and results are being compared to standardized measurement techniques such as electrochemical impedance spectroscopy. A brief description of the Impedance Noise Identification hardware system and representative test results are presented.

Jon P. Christophersen; Chester G. Motloch; John L. Morrison; Ian B. Donnellan; William H. Morrison

2008-07-01T23:59:59.000Z

118

Quantum noise and stochastic reduction  

E-Print Network (OSTI)

In standard nonrelativistic quantum mechanics the expectation of the energy is a conserved quantity. It is possible to extend the dynamical law associated with the evolution of a quantum state consistently to include a nonlinear stochastic component, while respecting the conservation law. According to the dynamics thus obtained, referred to as the energy-based stochastic Schrodinger equation, an arbitrary initial state collapses spontaneously to one of the energy eigenstates, thus describing the phenomenon of quantum state reduction. In this article, two such models are investigated: one that achieves state reduction in infinite time, and the other in finite time. The properties of the associated energy expectation process and the energy variance process are worked out in detail. By use of a novel application of a nonlinear filtering method, closed-form solutions--algebraic in character and involving no integration--are obtained for both these models. In each case, the solution is expressed in terms of a random variable representing the terminal energy of the system, and an independent noise process. With these solutions at hand it is possible to simulate explicitly the dynamics of the quantum states of complicated physical systems.

Dorje C. Brody; Lane P. Hughston

2005-08-29T23:59:59.000Z

119

Technical Note: Suppression of artifacts arising from simultaneous cone-beam imaging and RF transponder tracking in prostate radiotherapy  

SciTech Connect

Purpose: Artifacts in treatment-room cone-beam reconstructions have been observed at the authors' center when cone-beam acquisition is simultaneous with radio frequency (RF) transponder tracking using the Calypso 4D system (Calypso Medical, Seattle, WA). These artifacts manifest as CT-number modulations and increased CT-noise. The authors present a method for the suppression of the artifacts. Methods: The authors propose a three-stage postprocessing technique that can be applied to image volumes previously reconstructed by a cone-beam system. The stages are (1) segmentation of voxels into air, soft-tissue, and bone; (2) application of a 2D spatial-filter in the axial plane to the soft-tissue voxels; and (3) normalization to remove streaking along the axial-direction. The algorithm was tested on patient data acquired with Synergy XVI cone-beam CT systems (Elekta, Crawley, United Kingdom). Results: The computational demands of the suggested correction are small, taking less than 15 s per cone-beam reconstruction on a desktop PC. For a moderate loss of spatial-resolution, the artifacts are strongly suppressed and low-contrast visibility is improved. Conclusions: The correction technique proposed is fast and effective in removing the artifacts caused by simultaneous cone-beam imaging and RF-transponder tracking.

Poludniowski, Gavin; Webb, Steve; Evans, Philip M. [Joint Department of Physics, Division of Radiotherapy and Imaging, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT (United Kingdom)

2012-03-15T23:59:59.000Z

120

Classical approaches to predicting industrial noise  

Science Conference Proceedings (OSTI)

Predicting operational noise levels is an essential part of designing an industrial facility. Community noise levels are usually predicted for environmental assessment and licensing. In?plant noise levels are predicted

Frank H. Brittain

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

The multi-step phosphorelay mechanism of unorthodox two-component systems in E. coli realizes ultrasensitivity to stimuli while maintaining robustness to noises  

Science Conference Proceedings (OSTI)

E. coli has two-component systems composed of histidine kinase proteins and response regulator proteins. For a given extracellular stimulus, a histidine kinase senses the stimulus, autophosphorylates and then passes the phosphates to the cognate response ... Keywords: HK, HKP, Phosphorelay, RR, RRP, Robustness, TCS, Two-component systems, Ultrasensitivity, Unorthodox two-component systems

Jeong-Rae Kim; Kwang-Hyun Cho

2006-12-01T23:59:59.000Z

122

Suppressed Charmed B Decay  

SciTech Connect

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.

Snoek, Hella Leonie; /Vrije U., Amsterdam

2011-11-28T23:59:59.000Z

123

Analysis of kicker noise induced beam emittance growth  

SciTech Connect

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.

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.

2012-05-20T23:59:59.000Z

124

Uncorrelated Noise in Turbulence Measurements  

Science Conference Proceedings (OSTI)

We show that the error variance contributed by random uncorrelated measurement noise can be merged with the error variance contributed by real variations in the atmosphere to obtain a single expression for the total error variance when the ...

Donald H. Lenschow; Leif Kristensen

1985-03-01T23:59:59.000Z

125

Atomic clocks with suppressed blackbody radiation shift  

E-Print Network (OSTI)

We develop a nonstandard concept of atomic clocks where the blackbody radiation shift (BBRS) and its temperature fluctuations can be dramatically suppressed (by one to three orders of magnitude) independent of the environmental temperature. The suppression is based on the fact that in a system with two accessible clock transitions (with frequencies v1 and v2) which are exposed to the same thermal environment, there exists a "synthetic" frequency v_{syn} (v1-e12 v2) largely immune to the BBRS. As an example, it is shown that in the case of ion 171Yb+ it is possible to create a clock in which the BBRS can be suppressed to the fractional level of 10^{-18} in a broad interval near room temperature (300\\pm 15 K). We also propose a realization of our method with the use of an optical frequency comb generator stabilized to both frequencies v1 and v2. Here the frequency v_{syn} is generated as one of the components of the comb spectrum and can be used as an atomic standard.

V. I. Yudin; A. V. Taichenachev; M. V. Okhapkin; S. N. Bagayev; Chr. Tamm; E. Peik; N. Huntemann; T. E. Mehlstaubler; F. Riehle

2011-03-03T23:59:59.000Z

126

Gas turbine noise control  

Science Conference Proceedings (OSTI)

The use of gas turbine powered generators and pumping stations are likely to increase over the next two decades. Alternative fuel systems utilizing fluidized coal beds are likely in the near future

Louis A. Challis and Associates Pty. Ltd.

1979-01-01T23:59:59.000Z

127

Avoiding low frequency noise in packaged HVAC equipment  

Science Conference Proceedings (OSTI)

The purpose of this article is to help those involved in the design and commissioning of packaged HVAC systems to understand the root causes of low frequency noise problems and how to avoid many of them at the design stage. In the 1980's, two things happened to dramatically change the types of noise problems encountered in typical new construction. The first was the introduction of new energy regulations that favored variable air volume (VAV) distribution systems over constant volume air distribution systems. A by-product of VAV design is that mid- and high frequency sound pressure levels produced by current air terminal devices and diffusers in many applications are significantly lower than in the past. The second factor was a trend away from the use of built-up central station fan equipment in favor of packaged, floor-by-floor air handlers or rooftop units. As a result, today's HVAC system noise problems are not confined to just the roar and hiss of the past, but now include intense low frequency rumble and time modulation. Indeed, most current noise problems in modern buildings occur in the frequency range well below 250 Hz. A large fraction of these are a result of the dominant sound pressure levels in the 12 to 40 Hz region. These factors, combined with a substantial increase in the level of low frequency sound from the rest of the system, can produce a non-neutral, time modulated, rumbly sounding background noise that many people find objectionable.

Ebbing, C.E. (Carrier Corp., Syracuse, NY (United States). Commercial Unitary Division); Blazier, W.E.Jr. (Warren Blazier Associates, San Francisco, CA (United States))

1993-06-01T23:59:59.000Z

128

Environmental overview of geothermal development: the Geysers-Calistoga KGRA. Volume 3. Noise  

DOE Green Energy (OSTI)

Noise from geothermal resource development at The Geysers-Calistoga Known Geothermal Resource Area (KGRA) will cause community annoyance unless noise-level standards are set and adhered to. Venting of steam is the loudest source of noise and can reach 100 to 125 dBA at 20 to 100 ft; most of the other noise sources fall below 100 dBA and are those usually associated with construction and industrial projects. Enough data exist for assessment and decision making, but it is scattered and must be compiled. In addition, communities must decide on their criteria for noise levels. Residential areas in the Geysers-Calistoga KGRA will require more stringent controls on noise than will the open space of which KGRA is primarily composed. Existing tecnnology can reduce noise levels somewhat, but more effective silencing devices are needed, particularly on steam venting systems.

Leitner, P.

1978-08-16T23:59:59.000Z

129

A robust kernel-based fuzzy c-means algorithm by incorporating suppressed and magnified membership for MRI image segmentation  

Science Conference Proceedings (OSTI)

Bias-corrected fuzzy c-means (BCFCM) algorithm with spatial information has been proven effective for image segmentation. It still lacks enough robustness to noise and outliers. Some kernel versions of FCM with spatial constraints, such as KFCM_S1, ... Keywords: Kernel-based FCM, fuzzy c-means (FCM), image segmentation, magic resonance image segmentation, spatial bias correction, suppressed membership

Hsu-Shen Tsai; Wen-Liang Hung; Miin-Shen Yang

2012-10-01T23:59:59.000Z

130

Extra focal convective suppressing solar collector. Final technical progress report  

DOE Green Energy (OSTI)

This progress report describes work done on the Extra Focal Convective Suppressing Solar Collector. The topics of the report include sensor refinement for the tracking electronics, tracking controller refinement, system optics evaluation, absorber system material evaluation and performance, tracking hardware evaluation and refinement, and full scale prototype construction and testing.

NONE

1996-05-01T23:59:59.000Z

131

Optimization of the exposure parameters with signal-to-noise ratios considering human visual characteristics in digital mammography  

Science Conference Proceedings (OSTI)

The use of digital mammography systems has become widespread recently However, the optimal exposure parameters are uncertain in clinical practice We need to optimize the exposure parameter in digital mammography while maximizing image quality and minimizing ... Keywords: average glandular dose, detective quantum efficiency, digital mammography, noise equivalent quanta, noise power spectrum, signal-to-noise ratio

Maki Yamada; Yuri Kato; Naotoshi Fujita; Yoshie Kodera

2010-06-01T23:59:59.000Z

132

Flow and diffusion distributed structures with noise at the inlet  

Science Conference Proceedings (OSTI)

Flow and diffusion distributed structures (FDS) are stationary spatially periodic patterns that can be observed in reaction-diffusion-advection systems. These structures arise when the flow rate exceeds a certain bifurcation point provided that concentrations ... Keywords: 47.54.-r, 82.40.Ck, Flow and diffusion distributed structures, Flow distributed oscillations, Noise, Pattern formation, Reaction-diffusion-advection system

Pavel V. Kuptsov; Razvan A. Satnoianu

2008-11-01T23:59:59.000Z

133

Understanding and isolating the noise in the Linux kernel  

Science Conference Proceedings (OSTI)

Scientific applications are interrupted by the operating system far too often. Historically, operating systems have been optimized to time-share a single resource, the CPU. We now have an abundance of cores, but we are still swapping out the application ... Keywords: Linux, jitter, noise, partitioning, scheduling

Hakan Akkan, Michael Lang, Lorie Liebrock

2013-05-01T23:59:59.000Z

134

Kink instability suppression with stochastic cooling pickup and kicker  

Science Conference Proceedings (OSTI)

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.

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

2012-05-20T23:59:59.000Z

135

Stochastic noise characteristics in matrix inversion tomosynthesis (MITS)  

SciTech Connect

Matrix inversion tomosynthesis (MITS) uses known imaging geometry and linear systems theory to deterministically separate in-plane detail from residual tomographic blur in a set of conventional tomosynthesis (''shift-and-add'') planes. A previous investigation explored the effect of scan angle (ANG), number of projections (N), and number of reconstructed planes (NP) on the MITS impulse response and modulation transfer function characteristics, and concluded that ANG=20 deg., N=71, and NP=69 is the optimal MITS imaging technique for chest imaging on our prototype tomosynthesis system. This article examines the effect of ANG, N, and NP on the MITS exposure-normalized noise power spectra (ENNPS) and seeks to confirm that the imaging parameters selected previously by an analysis of the MITS impulse response also yield reasonable stochastic properties in MITS reconstructed planes. ENNPS curves were generated for experimentally acquired mean-subtracted projection images, conventional tomosynthesis planes, and MITS planes with varying combinations of the parameters ANG, N, and NP. Image data were collected using a prototype tomosynthesis system, with 11.4 cm acrylic placed near the image receptor to produce lung-equivalent beam hardening and scattered radiation. Ten identically acquired tomosynthesis data sets (realizations) were collected for each selected technique and used to generate ensemble mean images that were subtracted from individual image realizations prior to noise power spectra (NPS) estimation. NPS curves were normalized to account for differences in entrance exposure (as measured with an ion chamber), yielding estimates of the ENNPS for each technique. Results suggest that mid- and high-frequency noise in MITS planes is fairly equivalent in magnitude to noise in conventional tomosynthesis planes, but low-frequency noise is amplified in the most anterior and posterior reconstruction planes. Selecting the largest available number of projections (N=71) does not incur any appreciable additive electronic noise penalty compared to using fewer projections for roughly equivalent cumulative exposure. Stochastic noise is minimized by maximizing N and NP but increases with increasing ANG. The noise trend results for NP and ANG are contrary to what would be predicted by simply considering the MITS matrix conditioning and likely result from the interplay between noise correlation and the polarity of the MITS filters. From this study, the authors conclude that the previously determined optimal MITS imaging strategy based on impulse response considerations produces somewhat suboptimal stochastic noise characteristics, but is probably still the best technique for MITS imaging of the chest.

Godfrey, Devon J.; McAdams, H. P.; Dobbins, James T. III [Department of Radiology, Department of Biomedical Engineering, and Department of Radiation Oncology, Duke Advanced Imaging Laboratories, Duke University, DUMC 3295, Durham, North Carolina 27710 (United States); Department of Radiology, Duke Advanced Imaging Laboratories, Duke University, DUMC 3308, Durham, North Carolina 27710 (United States); Department of Radiology and Department of Biomedical Engineering, Duke Advanced Imaging Laboratories, Medical Physics Graduate Program, Duke University, 2424 Erwin Rd., Suite 302, Durham, North Carolina 27705 (United States)

2009-05-15T23:59:59.000Z

136

The digits-in-noise test: Assessing auditory speech recognition abilities in noise  

Science Conference Proceedings (OSTI)

A speech-in-noise test which uses digit triplets in steady-state speech noise was developed. The test measures primarily the auditory

Cas Smits; S. Theo Goverts; Joost M. Festen

2013-01-01T23:59:59.000Z

137

Nonlinear Noise in Cosmology  

E-Print Network (OSTI)

This paper derives and analyzes exact, nonlocal Langevin equations appropriate in a cosmological setting to describe the interaction of some collective degree of freedom with a surrounding ``environment.'' Formally, these equations are much more general, involving as they do a more or less arbitrary ``system,'' characterized by some time-dependent potential, which is coupled via a nonlinear, time-dependent interaction to a ``bath'' of oscillators with time-dependent frequencies. The analysis reveals that, even in a Markov limit, which can often be justified, the time dependences and nonlinearities can induce new and potentially significant effects, such as systematic and stochastic mass renormalizations and state-dependent ``memory'' functions, aside from the standard ``friction'' of a heuristic Langevin description. One specific example is discussed in detail, namely the case of an inflaton field, characterized by a Landau-Ginsburg potential, that is coupled quadratically to a bath of scalar ``radiation.'' T...

Habib, S; Habib, Salman; Kandrup, Henry E.

1992-01-01T23:59:59.000Z

138

Acoustical and Noise Control Criteria and Guidelines for Building Design and Operations  

E-Print Network (OSTI)

Noise, vibration and acoustical design, construction, commissioning and operation practices influence building cost, efficiency, performance and effectiveness. Parameters for structural vibration, building systems noise, acoustics and environmental noise crossing property boundaries will be presented with brief case studies illustrating noise and vibration problems with successful solutions. Building mechanical, power, and plumbing systems contribute to building operations noise and vibration, which affects building occupants, sensitive installations, and functional uses. Various noise and vibration design criteria, field measurements, design concepts and specifications can be applied in facilities to achieve noise mitigation and vibration control to enhance building operations and reduce tenant or neighbor problems. Concepts for enhancement will be presented that achieve specific program criteria and improve the built environment for occupants and functional uses, including items to incorporate in specifications and construction documents. Concepts relating to noise and vibration control can also reduce short and long-term operations costs and save energy. Acoustical designs can be implemented in new construction to achieve specific requirements for LEED certification in healthcare and educational facilities. Common problems, objective criteria, sensitive installations, and solutions will be presented to offer a basic understanding of effective noise and vibration control for central plant equipment, power systems, transformers, standby generators, and roof mounted HVAC equipment.

Evans, J. B.; Himmel, C. N.

2009-11-01T23:59:59.000Z

139

Simulation of synchrotron motion with rf noise  

Science Conference Proceedings (OSTI)

The theoretical formulation is described that is behind an algorithm for synchrotron phase-space tracking with rf noise and some preliminary simulation results of bunch diffusion under rf noise obtained by actual tracking.

Leemann, B.T.; Forest, E.; Chattopadhyay, S.

1986-08-01T23:59:59.000Z

140

The room noise criteria (RNC) metric.  

Science Conference Proceedings (OSTI)

The recent ANSI S12.2:2008 room noise criteria contains both a survey and an engineering method to specify room noise criteria. The methods use A?weighting and extended NC

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Quantization Noise Shaping on Arbitrary Frame Expansions  

E-Print Network (OSTI)

Quantization noise shaping is commonly used in oversampled A/D and D/A converters with uniform sampling. This paper considers quantization noise shaping for arbitrary finite frame expansions based on generalizing the view ...

Boufounos, Petros T.

142

EMISSION AND TRANSMISSION NOISE PROPAGATION IN POSITRON EMISSION COMPUTED TOMOGRAPHY  

E-Print Network (OSTI)

26-29, 1979 EMISSION AND TRANSMISSION NOISE PROPAGATION INLBL-9783 EMISSION AND TRANSMISSION NOISE PROPAGATION INl·. LBL-9783 EMISSION AND TRANSMISSION NOISE PROPAGATION IN

Gullberg, G.T.

2010-01-01T23:59:59.000Z

143

Research on Aluminum Foam Railway Noise Barrier  

Science Conference Proceedings (OSTI)

Abstract Scope, Frequency ranges of train noises are concentrated between ... Piezoelectric Smart Composites: Electromechanical Properties and Design Maps

144

Noise Analysis of Statham Temperature Chamber  

SciTech Connect

A procedure is described to subdue the noise made by the LN2 control valve on a Statham Temperature Chamber.

Mielke, R. L.

1973-01-15T23:59:59.000Z

145

Measurement, Modeling, and Suppression of Substrate Noise in Wide Band Mixed-Signal ICs  

E-Print Network (OSTI)

. Jeppson and C. M. Svensson. "Negative bias stress of MOS devices at high electric fields and degradation

Hansen, René Rydhof

146

Novel approaches to Newtonian noise suppression in interferometric gravitational wave detection  

E-Print Network (OSTI)

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 ...

Hunter-Jones, Nicholas R

2011-01-01T23:59:59.000Z

147

Simultaneous Velocity Ambiguity Resolution and Noise Suppression for Multifrequency Coherent Doppler Sonar  

Science Conference Proceedings (OSTI)

Coherent Doppler sonar is a useful tool for noninvasive measurement of ocean currents, sediment transport, and turbulence in coastal environments. Various methods have been proposed to separately address two of its inherent limitations: velocity ...

Jeremy Dillon; Len Zedel; Alex E. Hay

2012-03-01T23:59:59.000Z

148

A case history comparing noise criteria.  

Science Conference Proceedings (OSTI)

A case history of an indoor HVAC noise problem in a new residential building will be presented. Noise measurements collected in the living room and in the bedroom of the impacted living unit will be examined using several of the available noise criteria methods including

2009-01-01T23:59:59.000Z

149

Environmental Noise Source Classification Using Neural Networks  

Science Conference Proceedings (OSTI)

Neural networks have been applied to many interesting problems in different areas including noise identification/recognition. With this study, we studied noise classification using artificial neural networks (ANN). Three commonly encountered non-stationary ... Keywords: ACF-based feature parameter, environmental noise classification, Neural Networks (ANN)

Buket D. Barkana; Inci Saricicek

2010-04-01T23:59:59.000Z

150

The Acoustic Properties of Different Noise Sources  

Science Conference Proceedings (OSTI)

This paper discusses a method to find the acoustic properties of different types of background noise: highway, airport, subway, restaurant, rain, inside a car, and inside a train. Four parameters are calculated using the Auto Correlation Function (ACF). ... Keywords: Environmental noise, noise classification

Jidong Yang; Buket D. Barkana

2009-04-01T23:59:59.000Z

151

A Measurement First: NIST 'Noise Thermometry' System ...  

Science Conference Proceedings (OSTI)

... The Boltzmann constant* relates energy to temperature for individual particles such ... crucial underpinnings of science, including the definition of the ...

2011-10-14T23:59:59.000Z

152

Low-noise pulse conditioner  

DOE Patents (OSTI)

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.

Bird, D.A.

1981-06-16T23:59:59.000Z

153

Engineering to Control Noise, Loading, and Optimal Operating Points  

Science Conference Proceedings (OSTI)

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.

Mitchell R. Swartz

2000-11-12T23:59:59.000Z

154

Processing data base information having nonwhite noise  

DOE Patents (OSTI)

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.

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

1995-01-01T23:59:59.000Z

155

Isolating intrinsic noise sources in a stochastic genetic switch  

E-Print Network (OSTI)

The stochastic mutual repressor model is analysed using perturbation methods. This simple model of a gene circuit consists of two genes and three promotor states. Either of the two protein products can dimerize, forming a repressor molecule that binds to the promotor of the other gene. When the repressor is bound to a promotor, the corresponding gene is not transcribed and no protein is produced. Either one of the promotors can be repressed at any given time or both can be unrepressed, leaving three possible promotor states. This model is analysed in its bistable regime in which the deterministic limit exhibits two stable fixed points and an unstable saddle, and the case of small noise is considered. On small time scales, the stochastic process fluctuates near one of the stable fixed points, and on large time scales, a metastable transition can occur, where fluctuations drive the system past the unstable saddle to the other stable fixed point. To explore how different intrinsic noise sources affect these transitions, fluctuations in protein production and degradation are eliminated, leaving fluctuations in the promotor state as the only source of noise in the system. Perturbation methods are then used to compute the stability landscape and the distribution of transition times, or first exit time density. To understand how protein noise affects the system, small magnitude fluctuations are added back into the process, and the stability landscape is compared to that of the process without protein noise. It is found that significant differences in the random process emerge in the presence of protein noise.

Jay Newby

2011-11-06T23:59:59.000Z

156

Design of compartmental silencer for HVAC system  

Science Conference Proceedings (OSTI)

Air conditioning and ventilation system is the major noise sources in the commercial building. Noise will be propagated from fan and through the associated ductwork into working area. In order to reduce the noise transmitted

Y. H. Chan; Y. S. Choy; R. C. K. Leung

2012-01-01T23:59:59.000Z

157

Coating thermal noise for arbitrary shaped beams  

E-Print Network (OSTI)

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.

Richard O'Shaughnessy

2006-07-10T23:59:59.000Z

158

Advances in noise analysis for nuclear plant surveillance and diagnostics  

SciTech Connect

An automated surveillance and baseline noise signature acquisition system is being demonstrated at Sequoyah-1. A nonperturbing method is also being developed for monitoring the subcritical reactivity during initial core loading in LWRs, in fuel storage and processing facilities, and during postaccident recovery operations such as Three Mile Island-2. (DLC)

Fry, N.; Clapp, N.E. Jr.; Sides, W.H. Jr.; Mihalczo, J.T.; King, W.T.

1980-01-01T23:59:59.000Z

159

Fire suppression and detection equipment  

SciTech Connect

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.

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

2006-01-15T23:59:59.000Z

160

The stochastic nature induced by laser noise in narrow transitions  

E-Print Network (OSTI)

We use a probabilistic method to describe the effect of laser noise on the laser-atom interaction, in the case that the atom is a two level system without spontaneous emission. The stochastic differential equation for the laser-atom interaction is analyzed in the sense of perturbation approach, and we construct a stochastic process corresponding to the time evolution of the atom's wave function, whose extra randomness is induced by the laser noise. It also provides the layout of a theory for the possible experiment of measuring the laser line width by driving a narrow atomic transition.

Sun, Yuan

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

The stochastic nature induced by laser noise in narrow transitions  

E-Print Network (OSTI)

We use a probabilistic method to describe the effect of laser noise on the laser-atom interaction, in the case that the atom is a two level system without spontaneous emission. The stochastic differential equation for the laser-atom interaction is analyzed in the sense of perturbation approach, and we construct a stochastic process corresponding to the time evolution of the atom's wave function, whose extra randomness is induced by the laser noise. It also provides the layout of a theory for the possible experiment of measuring the laser line width by driving a narrow atomic transition.

Yuan Sun; Chen Zhang

2013-07-08T23:59:59.000Z

162

An optical spectrum analyzer with quantum limited noise floor  

E-Print Network (OSTI)

Interactions between atoms and lasers provide the potential for unprecedented control of quantum states. Fulfilling this potential requires detailed knowledge of frequency noise in optical oscillators with state-of-the-art stability. We demonstrate a technique that precisely measures the noise spectrum of an ultra-stable laser using optical lattice-trapped $^{87}$Sr atoms as a quantum projection noise-limited reference. We determine the laser noise spectrum from near DC to 100 Hz via the measured fluctuations in atomic excitation, guided by a simple and robust theory model. The noise spectrum yields a 26(4) mHz linewidth at a central frequency of 429 THz, corresponding to an optical Q of $1.6\\times10^{16}$. This approach improves upon optical heterodyne beats between two similar laser systems by providing information unique to a single laser, and complements the traditionally used Allan deviation which evaluates laser performance at relatively long time scales. We use this technique to verify the reduction of...

Bishof, Michael; Martin, Michael J; Ye, Jun

2013-01-01T23:59:59.000Z

163

Ambient Addition: How to turn urban noise into music  

E-Print Network (OSTI)

As human civilization devises ever more powerful machines, living among them may become more difficult. We may find ourselves surrounded by incidentally created sounds and noises which are out of synchronization with our momentary needs and discordant. Currently, legislating noise pollution is the only articulated solution and clearly it is not very effective. Our impression of sound, however, may be mediated and manipulated, transformed into something less jarring. So far, Walkmans and sound canceling headphones have done this, isolating us from noise but also from one another. In their place, a next generation headphone system is proposed which integrates environmental sound into a personal soundscape. It allows one to synthesize music from environmental sound using a number of digital signal processing (DSP) algorithms to create a sonic space in which the listener remains connected with his or her surroundings, is also cushioned from the most harsh and arrhythmic incursions and may also be drawn to

Noah Vawter; Noah Vawter; Noah Vawter; Chris Csikszentmihályi; Noah Vawter; Barry Vercoe

2006-01-01T23:59:59.000Z

164

A computer program for HVDC converter station RF noise calculations  

SciTech Connect

HVDC converter station operations generate radio frequency (RF) electromagnetic (EM) noise which could interfere with adjacent communication and computer equipment, and carrier system operations. A generic Radio Frequency Computer Analysis Program (RAFCAP) for calculating the EM noise generated by valve ignition of a converter station has been developed as part of a larger project. The program calculates RF voltages, currents, complex power, ground level electric field strength and magnetic flux density in and around an HVDC converter station. The program requires the converter station network to be represented by frequency dependent impedance functions. Comparisons of calculated and measured values are given for an actual HVDC station to illustrate the validity of the program. RAFCAP is designed to be used by engineers for the purpose of calculating the RF noise produced by the igniting of HVDC converter valves.

Kasten, D.G.; Caldecott, R.; Sebo, S.A. (Ohio State Univ., Columbus, OH (United States). Dept. of Electrical Engineering); Liu, Y. (Virginia Polytechnic Inst. State Univ., Blacksburg, VA (United States). Bradley Dept. of Electrical Engineering)

1994-04-01T23:59:59.000Z

165

Suppression of multiphoton intrashell resonances in Li Rydberg atoms  

Science Conference Proceedings (OSTI)

Multiphoton intrashell transitions in strongly driven Li (n=25) Rydberg atoms are studied experimentally. Orthogonal dc electric and magnetic fields lift the degeneracy of the n shell and define the eccentricity e of the initial coherent elliptic states, which are formed by laser excitation and subsequent adiabatic transformation. The intrashell transitions are driven by a time-harmonic electric field linearly polarized parallel to the major axis of the ellipse. N-photon resonances with N=1-9 are studied as a function of e. All resonances with N{>=}3 are suppressed at certain e values in between 0 and 1. A similar system was analyzed by Yabuzaki et al. [Phys. Rev. A 10, 1955 (1974)] who found a simple pattern of suppressions that applies also for the present experiments. The results of these experimentally confirm that each time N is increased by two, an additional suppression is observed.

Waheed, A. [Department of Physics and Technology, University of Bergen, N-5007 Bergen (Norway); Higher Education Commission of Pakistan, Islamabad (Pakistan); Fregenal, D. [Centro Atomico Bariloche and Consejo Nacional de Investigaciones Cienticas y Tecnicas. R8402AGP S.C. de Bariloche (Argentina); Frette, O.; Foerre, M.; Hjertaker, B. T.; Preclikova, J. [Department of Physics and Technology, University of Bergen, N-5007 Bergen (Norway); Horsdal, E. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark); Pilskog, I. [Department of Physics and Technology, University of Bergen, N-5007 Bergen (Norway); Laboratoire de Chimie Physique Matiere et Rayonnement, Universite Pierre et Marie Curie, Centre National de la Recherche Scientifique, UMR 7614, 75231 Paris Cedex 05 (France)

2011-06-15T23:59:59.000Z

166

Probing cell-free gene expression noise in femtoliter volumes  

SciTech Connect

Cell-free systems offer a simplified and flexible context that enables important biological reactions while removing complicating factors such as fitness, division, and mutation that are associated with living cells. However, cell-free expression in unconfined spaces is missing important elements of expression in living cells. In particular, the small volume of living cells can give rise to significant stochastic effects, which are negligible in bulk cell-free reactions. Here, we confine cell-free gene expression reactions to cell relevant 20 fL volumes (between the volumes of E. coli and S. cerevisiae), in polydimethylsiloxane (PDMS) containers. We demonstrate that expression efficiency varies widely at this volume, and we analyze gene expression noise. Noise analysis reveals signatures of translational bursting while noise dynamics suggest that overall cell-free expression is limited by a diminishing translation rate. In addition to offering a unique approach to understanding noise in gene circuits, our work contributes to a deeper understanding of the biophysical properties of cell-free expression systems, thus aiding efforts to harness cell-free systems for synthetic biology applications.

Karig, David K [ORNL; Jung, Seung-Yong [ORNL; Srijanto, Bernadeta R [ORNL; Collier, Pat [ORNL; Simpson, Michael L [ORNL

2013-01-01T23:59:59.000Z

167

Fundamental Performance Determining Factors of the Ultrahigh-Precision Space-Borne Optical Metrology System for the LISA Pathfinder mission  

E-Print Network (OSTI)

The LISA Pathfinder mission to space employs an optical metrology system (OMS) at its core to measure the distance and attitude between two freely floating test-masses to picometer and nanorad accuracy, respectively, within the measurement band of [1 mHz, 30 mHz]. The OMS is based upon an ultra-stable optical bench with 4 heterodyne interferometers from which interference signals are read-out and processed by a digital phase-meter. Laser frequency noise, power fluctuations and optical path-length variations are suppressed to uncritical levels by dedicated control loops so that the measurement performance approaches the sensor limit imposed by the phase-meter. The system design is such that low frequency common mode noise which affects the read-out phase of all four interferometers is generally well suppressed by subtraction of a reference phase from the other interferometer signals. However, high frequency noise directly affects measurement performance and its common mode rejection depends strongly on the relative signal phases. We discuss how the data from recent test campaigns point towards high frequency phase noise as a likely performance limiting factor which explains some important performance features.

Gerald Hechenblaikner; Reinhold Flatscher

2013-07-30T23:59:59.000Z

168

Noise Performance Evaluation of the Candidate Digitizers for the MAJORANA DEMONSTRATOR  

Science Conference Proceedings (OSTI)

The noise performance evaluation of the two digitizer cards being considered for the MAJORANA DEMONSTRATOR (MJD) is presented in this document. The procurement of the data acquisition electronics for the MJD is scheduled to happen this year. At the time of writing this document, there are two candidate digitizer electronic boards. One aspect that is being considered by the collaboration is the feasibility of using the MJD for dark matter searches. The feasibility of using the MJD for this application is going to be dictated by the ability of the demonstrator to reach sub-keV energy resolution. One of the potential sources of noise in the MJD is the data acquisition system. This document will is concluded with a recommendation for the final digitizer board by comparing the noise performance of the two electronics systems. Noise parameters such as the effective number of bits, input range linearity and signal to noise ratio are experimentally determined. The two digitizer cards feature different on-board digital signal processing and these features are compared. The experimental set-up was also used to identify sources of noise. This paper describes these sources of noise in the data acquisition system, along with mitigation strategies. Issues such as grounding and wiring scheme have an impact in the overall data acquisition system performance and are discussed in detail. As a conclusion, the suitability of each one of the cards to become the back bone of the data acquisition system of the MJD is discussed.

Aguayo Navarrete, Estanislao

2011-03-16T23:59:59.000Z

169

Electron acceleration in solar noise storms  

E-Print Network (OSTI)

We present an up-to-date review of the physics of electron acceleration in solar noise storms. We describe the observed characteristics of noise storm emission, emphasizing recent advances in imaging observations. We briefly describe the general methodology of treating particle acceleration problems and apply it to the specific problem of electron acceleration in noise storms. We dwell on the issue of the efficiency of the overall noise storm emission process and outline open problems in this area. 1.1 Motivation: Noise storms are the most common form of meter wavelength radio emission from the solar corona. The nomenclature arises from hissing sounds produced in short-wave radio receivers, and was coined around the 1930s. Noise storms are sites of long-lasting quasi-continuous electron acceleration in the

Prasad Subramanian

2007-01-01T23:59:59.000Z

170

Small Vessel Contribution to Underwater Noise  

SciTech Connect

Understanding the types of noise generated by a small boat is important for ensuring that marine ecosystems are protected from detrimental anthropogenic noise. Here we present the results of a field test conducted to examine the effects of engine RPM, number of engines and number of propeller blades on the broadband and narrowband noise produced by a small boat. The test boat was a 23-foot aluminum-hulled boat with dual 100 hp engines. The broadband noise and narrowband peak levels were observed using two hydrophones in different locations. The broadband noise levels were affected by both the number of engines and the RPM; the narrowband peaks showed a greater increase in amplitude with an increase in RPM than the broadband noise levels.

Matzner, Shari; Maxwell, Adam R.; Myers, Joshua R.; Caviggia, Kurt A.; Elster, Jennifer L.; Foley, Michael G.; Jones, Mark E.; Ogden, George L.; Sorensen, Eric L.; Zurk, Lisa M.; Tagestad, Jerry D.; Stephan, Alex J.; Peterson, Mary E.; Bradley, Donald J.

2010-12-10T23:59:59.000Z

171

Noise-assisted energy transfer in quantum networks and light-harvesting complexes  

E-Print Network (OSTI)

We provide physically intuitive mechanisms for the effect of noise on excitation energy transfer (EET) in networks. Using these mechanisms of dephasing-assisted transport (DAT) in a hybrid basis of both excitons and sites, we develop a detailed picture of how noise enables energy transfer with efficiencies well above $90%$ across the Fenna-Matthew-Olson (FMO) complex, a type of light harvesting molecule. We demonstrate explicitly how noise alters the pathways of energy transfer across the complex, suppressing ineffective pathways and facilitating direct ones to the reaction centre. We explain that the fundamental mechanisms underpinning DAT are expected to be robust with respect to the considered noise model but show that the specific details of the exciton-phonon coupling, which remain largely unknown in these type of complexes, and in particular the impact of non-Markovian effects, results in variations of dynamical features that should be amenable to experimental verification within current or planned technology. A detailed understanding of DAT in natural compounds should open up a new paradigm of `noise-engineering' by which EET can be optimized in artificial light-harvesting structures.

Alex W. Chin; Animesh Datta; Filippo Caruso; Susana F. Huelga; Martin B. Plenio

2009-10-21T23:59:59.000Z

172

Electron acceleration in solar noise storms  

E-Print Network (OSTI)

We present an up-to-date review of the physics of electron acceleration in solar noi se storms. We describe the observed characteristics of noise storm emission, emphasi zing recent advances in imaging observations. We briefly describe the general method ology of treating particle acceleration problems and apply it to the specific proble m of electron acceleration in noise storms. We dwell on the issue of the efficiency of the overall noise storm emission process and outline open problems in this area.

Subramanian, P

2007-01-01T23:59:59.000Z

173

Electron acceleration in solar noise storms  

E-Print Network (OSTI)

We present an up-to-date review of the physics of electron acceleration in solar noi se storms. We describe the observed characteristics of noise storm emission, emphasi zing recent advances in imaging observations. We briefly describe the general method ology of treating particle acceleration problems and apply it to the specific proble m of electron acceleration in noise storms. We dwell on the issue of the efficiency of the overall noise storm emission process and outline open problems in this area.

Prasad Subramanian

2007-01-23T23:59:59.000Z

174

Wind Turbine Acoustic Noise A white paper  

E-Print Network (OSTI)

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

Massachusetts at Amherst, University of

175

Monte Carlo SSA: Detecting irregular oscillations in the Presence of Colored Noise  

Science Conference Proceedings (OSTI)

Singular systems (or singular spectrum) analysis (SSA) was originally proposed for noise reduction in the analysis of experimental data and is now becoming widely used to identify intermittent or modulated oscillations in geophysical and climatic ...

Myles R. Allen; Leonard A. Smith

1996-12-01T23:59:59.000Z

176

Adaptive cancellation of geomagnetic background noise using a sign-error normalized LMS algorithm  

Science Conference Proceedings (OSTI)

Magnetic anomaly detection (MAD) systems are often used aboard aircraft to detect transient magnetic fields produced by submarines. In this operating environment, the earth's magnetic field produces a large undesirable noise component at the detector. ...

N. L. Freire; S. C. Douglas

1993-04-01T23:59:59.000Z

177

Holographic Indeterminacy, Uncertainty and Noise  

E-Print Network (OSTI)

A theory is developed to describe the nonlocal effect of spacetime quantization on position measurements transverse to macroscopic separations. Spacetime quantum states close to a classical null trajectory are approximated by plane wavefunctions of Planck wavelength (l_P) reference beams; these are used to connect transverse position operators at macroscopically separated events. Transverse positions of events with null spacetime separation, but separated by macroscopic spatial distance $L$, are shown to be quantum conjugate observables, leading to holographic indeterminacy and a new uncertainty principle, a lower bound on the standard deviation of relative transverse position \\Delta x_\\perp > \\sqrt{l_PL} or angular orientation \\Delta\\theta > \\sqrt{l_P/L}. The resulting limit on the number of independent degrees of freedom is shown to agree quantitatively with holographic covariant entropy bounds derived from black hole physics and string theory. The theory predicts a universal ``holographic noise'' of spacet...

Hogan, Craig J

2007-01-01T23:59:59.000Z

178

Quantum Noise as an Entanglement Meter  

E-Print Network (OSTI)

Entanglement entropy, which is a measure of quantum correlations between separate parts of a many-body system, has emerged recently as a fundamental quantity in broad areas of theoretical physics, from cosmology and field theory to condensed matter theory and quantum information. The universal appeal of the entanglement entropy concept is related, in part, to the fact that it is defined solely in terms of the many-body density matrix of the system, with no relation to any particular observables. However, for the same reason, it has not been clear how to access this quantity experimentally. Here we derive a universal relation between entanglement entropy and the fluctuations of current flowing through a quantum point contact (QPC) which opens a way to perform a direct measurement of entanglement entropy. In particular, by utilizing space-time duality of 1d systems, we relate electric noise generated by opening and closing the QPC periodically in time with the seminal S = 1/3 log L prediction of conformal field theory.

Israel Klich; Leonid Levitov

2008-04-08T23:59:59.000Z

179

Uniform-distribution attribute noise learnability  

Science Conference Proceedings (OSTI)

We study the problem of PAC-learning Boolean functions with random attribute noise under the uniform distribution. We define a noisy distance measure for function classes and show that if this measure is small for a class C and an attribute ... Keywords: Fourier analysis, computational learning theory, learning with noise

Nader H. Bshouty; Jeffrey C. Jackson; Christino Tamon

2003-12-01T23:59:59.000Z

180

Multi-class blue noise sampling  

Science Conference Proceedings (OSTI)

Sampling is a core process for a variety of graphics applications. Among existing sampling methods, blue noise sampling remains popular thanks to its spatial uniformity and absence of aliasing artifacts. However, research so far has been mainly focused ... Keywords: blue noise, dart throwing, multi-class, poisson hard/soft disk, relaxation, sampling

Li-Yi Wei

2010-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Possibilistic signal processing: How to handle noise?  

Science Conference Proceedings (OSTI)

We propose a novel approach for noise quantifier at each location of a signal. This method is based on replacing the conventional kernel-based approach extensively used in signal processing by an approach involving another kind of kernel: a possibility ... Keywords: Choquet integral, Kernel methods, Noise quantization, Possibility distribution, Signal processing

Kevin Loquin; Olivier Strauss; Jean-Francois Crouzet

2010-11-01T23:59:59.000Z

182

Chaos and noise in galactic potentials  

E-Print Network (OSTI)

ABBREVIATED ABSTRACT: This paper summarises an investigation of the effects of weak friction and noise in time-independent, nonintegrable potentials which admit both regular and stochastic orbits. The aim is to understand the qualitative effects of internal and external irregularities associated, e.g., with discreteness effects or couplings to an external environment, which stars in any real galaxy must experience. The two principal conclusions are: (1) These irregularities can be important on time scales much shorter than the natural relaxation time scale t_R associated with the friction and noise. For stochastic orbits friction and noise induce an average exponential divergence from the unperturbed Hamiltonian trajectory at a rate set by the value of the local Lyapunov exponent. Even weak noise can make a pointwise interpretation of orbits suspect already on time scales much shorter than t_R. (2) The friction and noise can also have significant effects on the statistical properties of ensembles of stochasti...

Habib, S; Mahon, M E; Habib, Salman; Kandrup, Henry E; Mahon, M Elaine

1994-01-01T23:59:59.000Z

183

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

E-Print Network (OSTI)

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).

Laszlo B. Kish; Robert Mingesz; Zoltan gingl

2007-05-01T23:59:59.000Z

184

Type-I Intermittency With Noise Versus Eyelet Intermittency  

E-Print Network (OSTI)

In this article we compare the characteristics of two types of the intermittent behavior (type-I intermittency in the presence of noise and eyelet intermittency taking place in the vicinity of the chaotic phase synchronization boundary) supposed hitherto to be different phenomena. We show that these effects are the same type of dynamics observed under different conditions. The correctness of our conclusion is confirmed by the consideration of different sample systems, such as quadratic map, Van der Pol oscillator and Rossler system. Consideration of the problem concerning the upper boundary of the intermittent behavior also confirms the validity of the statement on the equivalence of type-I intermittency in the presence of noise and eyelet intermittency observed in the onset of phase synchronization.

Alexander E. Hramov; Alexey Koronovskii; Maria Kurovskaya; Olga Moskalenko

2013-02-17T23:59:59.000Z

185

Suppression of decoherence effects in the quantum kicked rotor  

E-Print Network (OSTI)

We describe a method allowing transient suppression of decoherence effects on the atom-optics realization of the kicked rotor. The system is prepared in an initial state with a momentum distribution concentrated in an interval much sharper than the Brillouin zone; the measure of the momentum distribution is restricted to this interval of quasimomenta: As most of the atoms undergoing decoherence processes fall outside this detection range and thus are not detected, the measured signal is effectively decoherence-free.

Maxence Lepers; Véronique Zehnlé; Jean Claude Garreau

2010-04-15T23:59:59.000Z

186

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

E-Print Network (OSTI)

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.

Christian Arenz; Giulia Gualdi; Daniel Burgarth

2013-11-30T23:59:59.000Z

187

Designing Axial Flow Fan for Flow and Noise  

E-Print Network (OSTI)

A comprehensive finite element methodology is developed to predict the compressible flow performance of a non-symmetric 7-blade axial flow fan, and to quantify the source strength and sound pressure levels at any location in the system. The acoustic and flow performances of the fan are predicted simultaneously using a computational aero-acoustic technique combining transient flow analysis and noise propagation. The calculated sound power levels compare favorably with the measured sound power data per AMCA 300-96 code.

Subrata Roy; Phillip Cho; Fred Périé; International Off-highway

1999-01-01T23:59:59.000Z

188

Noise-sustained oscillation and synchronization of excitable media with stirring  

SciTech Connect

Constructive effects of noise have been well studied in spatially extended systems. In most of these studies, the media are static, reaction-diffusion type, and the constructive effects are a consequence of the interplay between local excitation due to noise perturbation and propagation of excitation due to diffusion. Many chemical or biological processes occur in a fluid environment with mixing. In this paper, we investigate the interplay among noise, excitability, diffusion and mixing in excitable media advected by a chaotic flow, in a 2-d Fitz Hugh-Nagumo model described by the reaction-advection-diffusion equations. Without stirring, noise can only generate non-coherent excited patches of the static media. In the presence of stirring, we can observe three dynamical and pattern formation regimes: (i) Non-coherent excitation, when mixing is not strong enough to achieve synchronization of independent excitations developed at different locations; (ii) Coherent global excitation, when noise-perturbation survives the mixing to generate a synchronized excitation of the whole domain; and (iii) Homogenization, when strong enough stirring dilutes quickly those noise-induced local excitations. In the presence of an external sub-threshold periodic forcing, the period of-the noise-sustained oscillations can be locked by the forcing period with different ratios. Our results may be verified in experiments and find applications in population dynamics of oceanic ecological systems.

Neufeld, Z. (Zoltan); Zhou, C. (Changsong); Kurths, J. (Jürgen),; Kiss, I. Z.

2004-01-01T23:59:59.000Z

189

Spacetime Indeterminacy and Holographic Noise  

E-Print Network (OSTI)

Arguments are presented for a new kind of quantum indeterminacy of transverse position, arising from holographic quantum degrees of freedom of spacetime. Indeterminacy of the angular orientation of particle trajectories due to wave/particle duality at the Planck scale leads to detectable indeterminacy of emergent spacetime over macroscopic distances. Quantum mechanically it can be expressed as a small nonvanishing commutator [ x_1, x_2]=-il_P L_{12} between position operators x_1 and x_2 transverse to a null trajectory at two events with rest frame separation L_{12}, leading to a formal uncertainty relation \\Delta x_1\\Delta x_2> l_P L_{12}/2, where l_P denotes the Planck length. The indeterminacy is interpreted as due to branching of the spacetime metric with spatial and temporal coherence scale ~ L_{12}. This hypothesis is sufficient to account for covariant bounds on entropy and for unitarity in black hole evaporation processes. The indeterminacy results in a universal holographic quantum spacetime noise, w...

Hogan, Craig J

2007-01-01T23:59:59.000Z

190

Holographic Indeterminacy, Uncertainty and Noise  

E-Print Network (OSTI)

A theory is developed to describe the nonlocal effect of spacetime quantization on position measurements transverse to macroscopic separations. Spacetime quantum states close to a classical null trajectory are approximated by plane wavefunctions of Planck wavelength (l_P) reference beams; these are used to connect transverse position operators at macroscopically separated events. Transverse positions of events with null spacetime separation, but separated by macroscopic spatial distance $L$, are shown to be quantum conjugate observables, leading to holographic indeterminacy and a new uncertainty principle, a lower bound on the standard deviation of relative transverse position \\Delta x_\\perp > \\sqrt{l_PL} or angular orientation \\Delta\\theta > \\sqrt{l_P/L}. The resulting limit on the number of independent degrees of freedom is shown to agree quantitatively with holographic covariant entropy bounds derived from black hole physics and string theory. The theory predicts a universal ``holographic noise'' of spacetime, appearing as shear perturbations with a frequency-independent power spectral density S_H=l_P/c, or in equivalent metric perturbation units, h_{H,rms} \\sqrt{l_P/c} = 2.3 \\times 10^{-22} /\\sqrt{Hz}. If this description of holographic phenomenology is valid, interferometers with current technology could undertake direct quantitative studies of quantum gravity.

Craig J. Hogan

2007-09-05T23:59:59.000Z

191

Spacetime Indeterminacy and Holographic Noise  

E-Print Network (OSTI)

A new kind of quantum indeterminacy of transverse position is shown to arise from quantum degrees of freedom of spacetime, based on the assumption that classical trajectories can be defined no better than the diffraction limit of Planck scale waves. Indeterminacy of the angular orientation of particle trajectories due to wave/particle duality at the Planck scale leads to indeterminacy of a nearly-flat spacetime metric, described as a small nonvanishing quantum commutation relation between transverse position operators at different events along a null trajectory. An independent derivation of the same effect is presented based on the requirement of unitarity in black hole evaporation. The indeterminacy is interpreted as a universal holographic quantum spacetime noise, with a frequency-independent spectrum of metric perturbation amplitude, h_H^2^{1/2} \\simeq \\sqrt{l_P}=2.3 \\times 10^{-22} /\\sqrt{Hz}, where l_P denotes the Planck length. The effect is estimated to be directly measurable using current interferometer technology similar to LIGO and LISA.

Craig J. Hogan

2007-06-13T23:59:59.000Z

192

Low phase noise, high bandwidth frequency synthesis techniques  

E-Print Network (OSTI)

A quantization noise reduction technique is proposed that allows fractional-N frequency synthesizers to achieve high closed loop bandwidth and low output phase noise simultaneously. Quantization induced phase noise is the ...

Meninger, Scott (Scott Edward), 1974-

2005-01-01T23:59:59.000Z

193

Blue whale response to underwater noise from commercial ships  

E-Print Network (OSTI)

D. , 1976. Mechanics of Underwater Noise. Pergamon PressD. , 1993. On ocean underwater ambient noise. AcousticsRichmond, M.E. , 2005. Underwater, low- frequency noise in a

McKenna, Megan Frances

2011-01-01T23:59:59.000Z

194

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

DOE Green Energy (OSTI)

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.

Long, M.; Stern, R.

1982-01-01T23:59:59.000Z

195

Noise-based communication and computing  

E-Print Network (OSTI)

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.

Laszlo B. Kish

2008-08-19T23:59:59.000Z

196

Quantifying Precipitation Suppression Due to Air Pollution  

Science Conference Proceedings (OSTI)

Urban air pollution and industrial air pollution have been shown qualitatively to suppress rain and snow. Here, precipitation losses over topographical barriers downwind of major coastal urban areas in California and in the land of Israel that ...

Amir Givati; Daniel Rosenfeld

2004-07-01T23:59:59.000Z

197

METHOD OF SUPPRESSING GASTROINTESTINAL UREASE ACTIVITY  

DOE Patents (OSTI)

This patent shows a method of increasing the growth rate of chicks. Certain diacyl substituted ureas such as alloxan, murexide, and barbituric acid are added to their feed, thereby suppressing gastrointestinal urease activity and thus promoting growth. (AEC)

Visek, W.J.

1963-04-23T23:59:59.000Z

198

A Frequency-Domain Silence Noise Model  

E-Print Network (OSTI)

Abstract. This paper proposes a simple, computationally efficient 2-mixture model approach to discrimination between speech and background noise. It is directly derived from observations on real data, and can be used in a fully unsupervised manner, with the EM algorithm. A first application to sector-based, joint audio source localization and detection, using multiple microphones, confirms that the model can provide major enhancement. A second application to the single channel speech recognition task in a noisy environment yields major improvement on stationary noise and promising results on non-stationary noise. 2 IDIAP–RR 05-13 1

Guillaume Lathoud A B; Guillaume Lathoud; Mathew Magimai. -doss; Bertrand Mesot

2005-01-01T23:59:59.000Z

199

Removing 1/f noise stripes in cosmic microwave background anisotropy observations  

E-Print Network (OSTI)

Removal of systematic effects is crucial in present and future CMB experiments mapping large fraction of the sky. Accurate CMB measurements ask for multi-feed array instruments observing the sky with a redundant scanning strategy covering the same region of the sky on different time scales and with different detectors for a better control of systematic effects. We investigate here the capability to suppress 1/f noise features in Time Ordered Data (TOD) by using the destriping technique described in Maino et al. (1999), under realistic assumptions for crossing condition between different scan circles and sky signal fluctuations on small angular scales. We consider as working case, Planck-LFI simulated observations with few arminutes pixel size convolved with LFI beam resolutions. We also extend the analysis to high values of the knee-frequency and found a residual additional noise rms ~31% larger than the pure white noise rms at fk=1 Hz which could be a critical issue in the extraction of the CMB angular power spectrum. Furthermore we verified that destriping quality does not significantly depend on the receiver sensitivity whereas it improves proportionally to the improvement of sampling rate. Therefore given a noise level, the higher the sampling rate, the better the destriping quality.

D. Maino; C. Burigana; K. M. Gorski; N. Mandolesi; M. Bersanelli

2002-02-14T23:59:59.000Z

200

Canonical suppression in microscopic transport models  

E-Print Network (OSTI)

We demonstrate the occurrence of canonical suppression associated with the conservation of an U(1)-charge in current transport models. For this study a pion gas is simulated within two different transport approaches by incorporating inelastic and volume-limited collisions $\\pi\\pi\\leftrightarrow K\\bar{K}$ for the production of kaon pairs. Both descriptions can dynamically account for the suppression in the yields of rare strange particles in a limited box, being in full accordance with a canonical statistical description.

O. Fochler; S. Vogel; M. Bleicher; C. Greiner; P. Koch-Steinheimer; Z. Xu

2006-01-20T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Optimization of Active Noise Control for Small Axial Cooling Fans.  

E-Print Network (OSTI)

??Previous work has shown that active noise control is a feasible solution to attenuate tonal noise radiated by small axial cooling fans, such as those… (more)

Monson, Brian B 1979-

2006-01-01T23:59:59.000Z

202

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

SciTech Connect

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.

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

2012-04-30T23:59:59.000Z

203

Signal and noise in global warming detection. Final progress report, July 15, 1990--July 14, 1994  

SciTech Connect

This research considers the mean squared error (MSE) incurred in estimating an idealized earth`s global average temperature with a finite network of point gauges distributed optimally over the globe. The construction of a linear smoothing filter is considered for estimating the forced part of a change in a climatological field such as the surface temperature. The filter is optimal in the sense that is suppresses the natural variability of noise relative to the forced part or signal to the maximum extent possible.

North, G.D.

1995-05-19T23:59:59.000Z

204

Endotoxin suppresses surfactant synthesis in cultured rat lung cells  

Science Conference Proceedings (OSTI)

Pulmonary complications secondary to postburn sepsis are a major cause of death in burned patients. Using an in vitro organotypic culture system, we examined the effect of E. coli endotoxin (LPS) on lung cell surfactant synthesis. Our results showed that E. coli endotoxin (1.0, 2.5, 10 micrograms LPS/ml) was capable of suppressing the incorporation of /sup 3/H-choline into de novo synthesized surfactant, lamellar bodies (LB), and common myelin figures (CMF) at 50%, 68%, and 64%, respectively. In a similar study, we were able to show that LPS also inhibited /sup 3/H-palmitate incorporation by cultured lung cells. LPS-induced suppression of surfactant synthesis was reversed by hydrocortisone. Our results suggest that LPS may play a significant role in reducing surfactant synthesis by rat lung cells, and thus contribute to the pathogenesis of sepsis-related respiratory distress syndrome (RDS) in burn injury.

Li, J.J.; Sanders, R.L.; McAdam, K.P.; Gelfand, J.A.; Burke, J.F.

1989-02-01T23:59:59.000Z

205

Transducer Signal Noise Analysis for Sensor Authentication  

SciTech Connect

The abstract is being passed through STIMS for submision to the conference. International safeguards organizations charged with promoting the peaceful use of nuclear energy employ unattended and remote monitoring systems supplemented with onsite inspections to ensure nuclear materials are not diverted for weaponization purposes. These systems are left unattended for periods of several months between inspections. During these periods physical security means are the main deterrent used to detect intentional monitoring system tampering. The information gathering components are locked in secure and sealed rooms. The sensor components (i.e. neutron and gamma detectors) are located throughout the plant in unsecure areas where sensor tampering could take place during the periods between inspections. Sensor tampering could allow the diversion of nuclear materials from the accepted and intended use to uses not consistent with the peaceful use of nuclear energy. A method and an apparatus is presented that address the detection of sensor tampering during the periods between inspections. It was developed at the Idaho National Laboratory (INL) for the Department of Energy (DOE) in support of the IAEA. The method is based on the detailed analysis of the sensor noise floor after the sensor signal is removed. The apparatus consists of a 2.1” x 2.6” electronic circuit board containing all signal conditioning and processing components and a laptop computer running an application that acquires and stores the analysis results between inspection periods. The sensors do not require any modification and are remotely located in their normal high radiation zones. The apparatus interfaces with the sensor signal conductors using a simple pass through connector at the normal sensor electronics interface package located in the already secure and sealed rooms. The apparatus does not require hardening against the effects of radiation due to its location. Presented is the apparatus design, the analysis method, and the test results as applied to tamper detection using three HE3 neutron sensors and two gamma sensors designed and built for safeguards monitoring.

John M. Svoboda (043887); Mark J. Schanfein

2012-07-01T23:59:59.000Z

206

A low noise charge ramp electrometer  

DOE Patents (OSTI)

This invention depicts a electrometer capable of measuring small currents without the use of a feedback resistor which tends to contribute a large noise factor to the measured data. The electrometer eliminates the feedback resistor through the use of a feedback capacitor located across the electrometer amplifier. The signal from the electrometer amplifier is transferred to a electrometer buffer amplifier which serves to transfer the signal to several receptors. If the electrometer amplifier is approaching saturation, the buffer amplifier signals a reset discriminator which energizes a coil whose magnetic field closes a magnetic relay switch which in turn resets or zeros the feedback capacitor. In turn, a reset complete discriminator restarts the measurement process when the electrometer amplifier approaches its initial condition. The buffer amplifier also transmits the voltage signal from the electrometer amplifier to a voltage-to-frequency converter. The signals from the voltage-to-frequency converter are counted over a fixed period of time and the information is relayed to a data processor. The timing and sequencing of the small current measuring system is under the control of a sequence control logic unit.

Morgan, J.P.; Piper, T.C.

1991-12-31T23:59:59.000Z

207

Thermophoresis of Brownian particles driven by coloured noise  

E-Print Network (OSTI)

The Brownian motion of microscopic particles is driven by the collisions with the molecules of the surrounding fluid. The noise associated with these collisions is not white, but coloured due, e.g., to the presence of hydrodynamic memory. The noise characteristic time scale is typically of the same order as the time over which the particle's kinetic energy is lost due to friction (inertial time scale). We demonstrate theoretically that, in the presence of a temperature gradient, the interplay between these two characteristic time scales can have measurable consequences on the particle long-time behaviour. Using homogenization theory, we analyse the infinitesimal generator of the stochastic differential equation describing the system in the limit where the two characteristic times are taken to zero; from this generator, we derive the thermophoretic transport coefficient, which, we find, can vary in both magnitude and sign, as observed in experiments. Furthermore, studying the long-term stationary particle dist...

Hottovy, Scott; Wehr, Jan

2012-01-01T23:59:59.000Z

208

Weather Noise Forcing of Surface Climate Variability  

Science Conference Proceedings (OSTI)

A model-based method to evaluate the role of weather noise forcing of low-frequency variability of surface properties, including SST, surface currents, land surface temperature, and soil moisture, is presented. In this procedure, an “interactive ...

Edwin K. Schneider; Meizhu Fan

2007-09-01T23:59:59.000Z

209

Tropical Convective Variability as 1/f Noise  

Science Conference Proceedings (OSTI)

Evidence is presented that the tropical convective variability behaves as 1/f noise for a 1–30-day period. This behavior is shown by analyzing the time series of convective available potential energy, which measures the degree of convective ...

Jun-Ichi Yano; Klaus Fraedrich; Richard Blender

2001-09-01T23:59:59.000Z

210

Separating signal and noise in climate warming  

NLE Websites -- All DOE Office Websites (Extended Search)

11162011 | NR-11-11-03 Separating signal and noise in climate warming Anne M Stark, LLNL, (925) 422-9799, stark8@llnl.gov Printer-friendly A National Oceanic and Atmospheric...

211

Quantum capacity of channel with thermal noise  

E-Print Network (OSTI)

The quantum capacity of thermal noise channel is studied. The extremal input state is obtained at the postulation that the coherent information is convex or concave at its vicinity. When the input energy tends to infinitive, it is verified by perturbation theory that the coherent information reaches its maximum at the product of identical thermal state input. The quantum capacity is obtained for lower noise channel and it is equal the one shot capacity.

Xiao-yu Chen

2006-02-11T23:59:59.000Z

212

Multi-band OFDM UWB receiver with narrowband interference suppression  

E-Print Network (OSTI)

A multi band orthogonal frequency division multiplexing (MB-OFDM) compatible ultra wideband (UWB) receiver with narrowband interference (NBI) suppression capability is presented. The average transmit power of UWB system is limited to -41.3 dBm/MHz in order to not interfere existing narrowband systems. Moreover, it must operate even in the presence of unintentional radiation of FCC Class-B compatible devices. If this unintentional radiation resides in the UWB band, it can jam the communication. Since removing the interference in digital domain requires higher dynamic range of analog front-end than removing it in analog domain, a programmable analog notch filter is used to relax the receiver requirements in the presence of NBI. The baseband filter is placed before the variable gain amplifier (VGA) in order to reduce the signal swing at the VGA input. The frequency hopping period of MB-OFDM puts a lower limit on the settling time of the filter, which is inverse proportional to notch bandwidth. However, notch bandwidth should be low enough not to attenuate the adjacent OFDM tones. Since these requirements are contradictory, optimization is needed to maximize overall performance. Two different NBI suppression schemes are tested. In the first scheme, the notch filter is operating for all sub-bands. In the second scheme, the notch filter is turned on during the sub-band affected by NBI. Simulation results indicate that the UWB system with the first and the second suppression schemes can handle up to 6 dB and 14 dB more NBI power, respectively. The results of this work are not limited to MB-OFDM UWB system, and can be applied to other frequency hopping systems.

Kelleci, Burak

2007-12-01T23:59:59.000Z

213

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  

Science Conference Proceedings (OSTI)

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.

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

2011-09-30T23:59:59.000Z

214

Rain noise level measurements in a performing arts center  

Science Conference Proceedings (OSTI)

Noise level measurements made in a performance hall and in related spaces with subjectively described light

Robert C. Coffeen

2007-01-01T23:59:59.000Z

215

Noise in current-commutating passive FET mixers  

Science Conference Proceedings (OSTI)

Noise in the mixer of zero-IF receivers can compromise the overall receiver sensitivity. The evolution of a passive CMOS mixer based on the knowledge of the physical mechanisms of noise in an active mixer is explained. Qualitative physical models that ... Keywords: flicker noise, passive mixer, physical mechanism, white noise, zero-IF

Saeed Chehrazi; Ahmad Mirzaei; Asad A. Abidi

2010-02-01T23:59:59.000Z

216

Reduction of 1/f noise in graphene after electron-beam irradiation  

Science Conference Proceedings (OSTI)

We investigated experimentally the effect of the electron-beam irradiation on the level of the low-frequency 1/f noise in graphene devices. It was found that 1/f noise in graphene reduces with increasing concentration of defects induced by irradiation. The increased amount of structural disorder in graphene under irradiation was verified with micro-Raman spectroscopy. The bombardment of graphene devices with 20-keV electrons reduced the noise spectral density, S{sub I}/I{sup 2} (I is the source-drain current) by an order-of magnitude at the radiation dose of 10{sup 4} {mu}C/cm{sup 2}. We analyzed the observed noise reduction in the limiting cases of the mobility and carrier number fluctuation mechanisms. The obtained results are important for the proposed graphene applications in analog, mixed-signal, and radio-frequency systems, integrated circuits and sensors.

Zahid Hossain, Md. [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California-Riverside, Riverside, California 92521 (United States)] [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California-Riverside, Riverside, California 92521 (United States); Rumyantsev, Sergey [Center for Integrated Electronics and Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States) [Center for Integrated Electronics and Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Ioffe Physical-Technical Institute, The Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Shur, Michael S. [Center for Integrated Electronics and Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)] [Center for Integrated Electronics and Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Balandin, Alexander A. [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California-Riverside, Riverside, California 92521 (United States) [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California-Riverside, Riverside, California 92521 (United States); Materials Science and Engineering Program, University of California-Riverside, Riverside, California 92521 (United States)

2013-04-15T23:59:59.000Z

217

Occupational Noise Exposure and its Potential Health Effects  

Science Conference Proceedings (OSTI)

This issue brief provides the electric power industry with a snapshot of the current scientific knowledge on worker health and safety risks associated with noise exposure. Noise exposure types are varied and include continuous, intermittent and/or impulse noise. Prolonged occupational exposure to continuous noise or acoustic trauma can cause noise-induced hearing loss. Recent scientific data from the aluminum industry suggest that those exposed below levels requiring hearing protective devices may ...

2012-12-31T23:59:59.000Z

218

Chaos and Noise in Galactic Potentials  

E-Print Network (OSTI)

ABBREVIATED ABSTRACT: This paper summarises an investigation of the effects of weak friction and noise in time-independent, nonintegrable potentials which admit both regular and stochastic orbits. The aim is to understand the qualitative effects of internal and external irregularities associated, e.g., with discreteness effects or couplings to an external environment, which stars in any real galaxy must experience. The two principal conclusions are: (1) These irregularities can be important on time scales much shorter than the natural relaxation time scale t_R associated with the friction and noise. For stochastic orbits friction and noise induce an average exponential divergence from the unperturbed Hamiltonian trajectory at a rate set by the value of the local Lyapunov exponent. Even weak noise can make a pointwise interpretation of orbits suspect already on time scales much shorter than t_R. (2) The friction and noise can also have significant effects on the statistical properties of ensembles of stochastic orbits, these also occurring on time scales much shorter than t_R. Potential implications for galactic dynamics are discussed, including the problem of shadowing.

Salman Habib; Henry E. Kandrup; M. Elaine Mahon

1994-09-19T23:59:59.000Z

219

Noise minimization in eukaryotic gene expression  

Science Conference Proceedings (OSTI)

All organisms have elaborate mechanisms to control rates of protein production. However, protein production is also subject to stochastic fluctuations, or noise. Several recent studies in Saccharomyces cerevisiae and Escherichia coli have investigated the relationship between transcription and translation rates and stochastic fluctuations in protein levels, or more generally, how such randomness is a function of intrinsic and extrinsic factors. However, the fundamental question of whether stochasticity in protein expression is generally biologically relevant has not been addressed, and it remains unknown whether random noise in the protein production rate of most genes significantly affects the fitness of any organism. We propose that organisms should be particularly sensitive to variation in the protein levels of two classes of genes: genes whose deletion is lethal to the organism and genes that encode subunits of multiprotein complexes. Using an experimentally verified model of stochastic gene expression in S. cerevisiae, we estimate the noise in protein production for nearly every yeast gene, and confirm our prediction that the production of essential and complex-forming proteins involves lower levels of noise than does the production of most other genes. Our results support the hypothesis that noise in gene expression is a biologically important variable, is generally detrimental to organismal fitness, and is subject to natural selection.

Fraser, Hunter B.; Hirsh, Aaron E.; Giaever, Guri; Kumm, Jochen; Eisen, Michael B.

2004-01-15T23:59:59.000Z

220

Interconnect Coupling Noise in CMOS VLSI Circuits  

E-Print Network (OSTI)

Interconnect between a CMOS driver and re- ceiver can be modeled as a 1ossy transmission line in high speed CMOS VLSI circuits as transition times become comparable to or less than the time of flight delay of the signal through the low resistivity interconnect. In this paper, closed form expressions for the coupling noise between adjacent interconnect are presented to estimate the coupling noise voltage on a quiet line. These expressions are based on an assumption that the interconnections are loosely coupled, where the effect of the coupling noise on the waveform of the active line is small and can be ne- glected. It is demonstrated that the output impedance of the CMOS driver should preferably be comparable to the interconnect impedance in order to reduce the propagation delay of the CMOS driver stage.

Kevin T. Tang; Eby G. Friedman

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Chaos and noise in galactic potentials  

Science Conference Proceedings (OSTI)

This paper summarizes an investigation of the effects of weak friction and noise in time-independent, nonintegrable two-dimensional potentials that admit both regular and stochastic orbits. The aim is to understand the qualitative effects of internal and external irregularities associated with discreteness effects or couplings to an external environment, which stars in any real galaxy must experience. It is found that these irregularities can be important already on timescales much shorter than the natural relaxation timescale t{sub R} associated with two-body relaxation. In particular, for stochastic orbits friction and noise result in an exponential divergence from the unperturbed Hamiltonian trajectory, at a rate set by the value of the local Lyapunov exponent, which persists even for relatively large deviations from the unperturbed trajectory. Friction and noise can also have significant effects on the {ital statistical} properties of ensembles of stochastic orbits. Stochastic orbits may be divided into two classes, confined or sticky stochastic orbits which are trapped near islands of regularity, and unconfined or filling stochastic orbits that travel unimpeded throughout a stochastic sea. In the absence of friction and noise, transitions between confined and filling stochastic orbits are very slow. However, even very weak friction and noise can drastically accelerate such transitions, leading to an approach toward a statistical equilibrium on timescales {lt}t{sub R}. In the two-dimensional models studied in this paper, there are cases for which t{sub R} exceeds 10{sup 6} crossing times where friction and noise can induce transitions for more than half the orbits within 100 crossing times, this corresponding in galaxies to a Hubble time t{sub H}. Implications for galactic dynamics are discussed. {copyright} {ital 1997} {ital The American Astronomical Society}

Habib, S. [T-6, Theoretical Astrophysics, and T-8, Elementary Particles and Field Theory, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [T-6, Theoretical Astrophysics, and T-8, Elementary Particles and Field Theory, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kandrup, H.E. [Department of Astronomy and Institute for Fundamental Theory, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Astronomy and Institute for Fundamental Theory, University of Florida, Gainesville, Florida 32611 (United States); [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States); Mahon, M.E. [Department of Astronomy and Institute for Fundamental Theory, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Astronomy and Institute for Fundamental Theory, University of Florida, Gainesville, Florida 32611 (United States)

1997-05-01T23:59:59.000Z

222

Genetic noise control via protein oligomerization  

Science Conference Proceedings (OSTI)

Gene expression in a cell entails random reaction events occurring over disparate time scales. Thus, molecular noise that often results in phenotypic and population-dynamic consequences sets a fundamental limit to biochemical signaling. While there have been numerous studies correlating the architecture of cellular reaction networks with noise tolerance, only a limited effort has been made to understand the dynamical role of protein-protein associations. We have developed a fully stochastic model for the positive feedback control of a single gene, as well as a pair of genes (toggle switch), integrating quantitative results from previous in vivo and in vitro studies. In particular, we explicitly account for the fast protein binding-unbinding kinetics, RNA polymerases, and the promoter/operator sequences of DNA. We find that the overall noise-level is reduced and the frequency content of the noise is dramatically shifted to the physiologically irrelevant high-frequency regime in the presence of protein dimerization. This is independent of the choice of monomer or dimer as transcription factor and persists throughout the multiple model topologies considered. For the toggle switch, we additionally find that the presence of a protein dimer, either homodimer or heterodimer, may significantly reduce its intrinsic switching rate. Hence, the dimer promotes the robust function of bistable switches by preventing the uninduced (induced) state from randomly being induced (uninduced). The specific binding between regulatory proteins provides a buffer that may prevent the propagation of fluctuations in genetic activity. The capacity of the buffer is a non-monotonic function of association-dissociation rates. Since the protein oligomerization per se does not require extra protein components to be expressed, it provides a basis for the rapid control of intrinsic or extrinsic noise. The stabilization of phenotypically important toggle switches, and nested positive feedback loops in general, is of direct implications to organism fitness. Finally, noise control through oligomerization suggests avenues for the design of robust synthetic gene circuits for engineering purposes.

Ghim, C; Almaas, E

2008-06-12T23:59:59.000Z

223

Imaging extrasolar planets by stellar halo suppression in separately-corrected color bands  

E-Print Network (OSTI)

Extra-solar planets have not been imaged directly with existing ground or space telescopes because they are too faint to be seen against the halo of the nearby bright star. Most techniques being explored to suppress the halo are achromatic, with separate correction of diffraction and wavefront errors. Residual speckle structure may be subtracted by differencing images taken through narrowband filters, but photon noise remains and ultimately limits sensitivity. Here we describe two ways to take advantage of narrow bands to reduce speckle photon flux and to obtain better control of systematic errors. Multiple images are formed in separate color bands of 5-10% bandwidth, and recorded by coronagraphic interferometers equipped with active control of wavefront phase and/or amplitude. In one method, a single deformable pupil mirror is used to actively correct both diffraction and wavefront components of the halo. This yields good diffraction suppression for complex pupil obscuration, with high throughput over half the focal plane. In a second method, the coronagraphic interferometer is used as a second stage after conventional apodization. The halo from uncontrollable residual errors in the pupil mask or wavefront is removed by destructive interference made directly at the detector focal plane with an "anti-halo", synthesized by spatial light modulators in the reference arm of the interferometer. In this way very deep suppression may be achieved by control elements with greatly relaxed, and thus achievable, tolerances. In both examples, systematic errors are minimized because the planet imaging cameras themselves also provide the error sensing data.

Johanan L. Codona; Roger Angel

2004-02-17T23:59:59.000Z

224

Amplitude modulation of wind turbine noise  

E-Print Network (OSTI)

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).

Makarewicz, Rufin

2013-01-01T23:59:59.000Z

225

On the influence of pulsed jamming and coloured noise in UWB transmission  

E-Print Network (OSTI)

This paper compares the performances of an ultra wideband (UWB) system in additive white Gaussian noise (AWGN) channel in presence of a pulsed jamming or a coloured Gaussian noise allocated in the UMTS-FDD (FDD = Frequency Division Duplex) uplink band. Several modulation schemes have been implemented in order to analyze the efficiency and the robustness of different UWB systems when the studied interferences are present in the channel. Results showed that the particular UWB modulation scheme chosen doesn’t affect effectively the degradation of performances introduced by the interference, giving a precise rank order for the different UWB concepts. Nevertheless, due to the band allocation of the interference, the pulsed jamming source worsens the performance of the system more significantly than the coloured noise for low interference power. For high values, instead, the behaviour is inverted. 1.

Raffaello Tesi; Matti Hämäläinen; Jari Iinatti; Veikko Hovinen

1993-01-01T23:59:59.000Z

226

Signal and noise in global warming detection. Final report  

SciTech Connect

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?

North, G.R.

1998-11-01T23:59:59.000Z

227

Noise performance of the D0 layer 0 silicon detector  

SciTech Connect

A new inner detector called Layer 0 has been added to the existing silicon detector for the DZero colliding beams experiment. This detector has an all carbon fiber support structure that employs thin copper clad Kapton sheets embedded in the surface of the carbon fiber structure to improve the grounding of the structure and a readout system that fully isolates the local detector ground from the rest of the detector. Initial measurements show efficiencies greater than 90% and 0.3 ADC count common mode contribution to the signal noise.

Johnson, M.; /Fermilab

2006-11-01T23:59:59.000Z

228

Digitization Noise in Power Spectral Analysis  

Science Conference Proceedings (OSTI)

It is well-known that the digitization noise variance is ?2/12 for a continuous time series sampled with the signal resolution ?. It is also generally accepted that this variance often has a white-power spectral density. We have examined in ...

L. Kristensen; P. Kirkegaard

1987-06-01T23:59:59.000Z

229

Quantum bath-driven decoherence of mixed spin systems  

E-Print Network (OSTI)

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.

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

2013-02-07T23:59:59.000Z

230

SUPPRESSION OF ENERGETIC ELECTRON TRANSPORT IN FLARES BY DOUBLE LAYERS  

SciTech Connect

During flares and coronal mass ejections, energetic electrons from coronal sources typically have very long lifetimes compared to the transit times across the systems, suggesting confinement in the source region. Particle-in-cell simulations are carried out to explore the mechanisms of energetic electron transport from the corona to the chromosphere and possible confinement. We set up an initial system of pre-accelerated hot electrons in contact with ambient cold electrons along the local magnetic field and let it evolve over time. Suppression of transport by a nonlinear, highly localized electrostatic electric field (in the form of a double layer) is observed after a short phase of free-streaming by hot electrons. The double layer (DL) emerges at the contact of the two electron populations. It is driven by an ion-electron streaming instability due to the drift of the back-streaming return current electrons interacting with the ions. The DL grows over time and supports a significant drop in temperature and hence reduces heat flux between the two regions that is sustained for the duration of the simulation. This study shows that transport suppression begins when the energetic electrons start to propagate away from a coronal acceleration site. It also implies confinement of energetic electrons with kinetic energies less than the electrostatic energy of the DL for the DL lifetime, which is much longer than the electron transit time through the source region.

Li, T. C.; Drake, J. F.; Swisdak, M. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD 20742 (United States)

2012-09-20T23:59:59.000Z

231

Noise Reduction with Microphone Arrays for Speaker Identification  

SciTech Connect

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?

Cohen, Z

2011-12-22T23:59:59.000Z

232

Acoustic Array Development for Wind Turbine Noise Characterization  

DOE Green Energy (OSTI)

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.

Buck, S.; Roadman, J.; Moriarty, P.; Palo, S.

2013-11-01T23:59:59.000Z

233

Noise Analysis in Ligand-Binding Reception for Molecular Communication in Nanonetworks  

E-Print Network (OSTI)

Abstract—Molecular communication (MC) will enable the exchange of information among nanoscale devices. In this novel bioinspired communication paradigm, molecules are employed to encode, transmit and receive information. In the most general case, these molecules are propagated in the medium by means of free diffusion. An information theoretical analysis of diffusion-based MC is required to better understand the potential of this novel communication mechanism. The study and the modeling of the noise sources is of utmost importance for this analysis. The objective of this paper is to provide a mathematical study of the noise at the reception of the molecular information in a diffusion-based MC system when the ligand-binding reception is employed. The reference diffusion-based MC system for this analysis is the physical end-to-end model introduced in a previous work by the same authors, where the reception process is realized through ligandbinding chemical receptors. The reception noise is modeled in this paper by following two different approaches, namely, through the ligand-receptor kinetics and through the stochastic chemical kinetics. The ligand-receptor kinetics allows to simulate the random perturbations in the chemical processes of the reception, while the stochastic chemical kinetics provides the tools to derive a closedform solution to the modeling of the reception noise. The ligand-receptor kinetics model is expressed through a block scheme, while the stochastic chemical kinetics results in the characterization of the reception noise using stochastic differential equations. Numerical results are provided to demonstrate that the analytical formulation of the reception noise in terms of stochastic chemical kinetics is compliant with the reception noise behavior resulting from the ligand-receptor kinetics simulations. Index Terms—Chemical master equation, diffusion, ligand-receptor kinetics, molecular communication, nanonetworks, nanotechnology,

Massimiliano Pierobon; Ian F. Akyildiz

2010-01-01T23:59:59.000Z

234

Uniform-Distribution Attribute Noise Learnability Nader H. Bshouty  

E-Print Network (OSTI)

by Shackelford and Volper [10] for the case of k-DNF expressions. Their uniform attribute noise model consists] that is the same for every attribute. While Shackelford and Volper assumed that the learner knows the noise rate p

Jackson, Jeffrey

235

Effects of Noise on Thorpe Scales and Run Lengths  

Science Conference Proceedings (OSTI)

Estimating the diapycnal mixing rate from standard CTD data by identifying overturning regions in the water column (the Thorpe-scale approach) provides good spatial and temporal coverage but is sometimes limited by instrument noise. This noise ...

Helen L. Johnson; Chris Garrett

2004-11-01T23:59:59.000Z

236

Random Offset Curves and Surfaces with Controllable Noise (Extended Abstract)  

E-Print Network (OSTI)

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

Lee, In-Kwon

237

Correlations between Ambient Noise and the Ocean Surface Wave Field  

Science Conference Proceedings (OSTI)

Measurements of the ambient noise spectrum level N with simultaneous, coincident wind and wave measurements were made from RP FLIP in fall 1991. The measurements were designed to investigate the correlation between the ambient noise and relevant ...

Francis C. Felizardo; W. Kendall Melville

1995-04-01T23:59:59.000Z

238

Application of a computer model for predicting remote noise levels  

Science Conference Proceedings (OSTI)

The prediction of noise levels at selected remote locations is an integral part of estimating the environmental impact of new stationary sources or of noise reduction for existing facilities. A three?dimensional computermodel

S. H. Judd; S. L. Dryden

1975-01-01T23:59:59.000Z

239

Modeling and managing separation for noise abatement arrival procedures  

E-Print Network (OSTI)

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 ...

Ren, Liling

2007-01-01T23:59:59.000Z

240

Noise Interaction Between Power Distribution Grids and Substrate  

Science Conference Proceedings (OSTI)

We have investigated the interaction between power delivery and substrate coupling in terms of noise. From our results, we identify that an increased density of substrate contacts does not to any significance decrease noise on the power supply lines. ... Keywords: Substrate noise, power supply

Daniel A. Andersson; Simon Kristiansson; Lars J. Svensson; Per Larsson-Edefors; Kjell O. Jeppson

2008-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Determination of parameters of a nuclear reactor through noise measurements  

DOE Patents (OSTI)

A method of measuring parameters of a nuclear reactor by noise measurements is described. Noise signals are developed by the detectors placed in the reactor core. The polarity coincidence between the noise signals is used to develop quantities from which various parameters of the reactor can be calculated. (auth)

Cohn, C.E.

1975-07-15T23:59:59.000Z

242

Influence of refraction on wind turbine noise  

E-Print Network (OSTI)

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.

Makarewicz, Rufin

2013-01-01T23:59:59.000Z

243

Low Noise Borehole Triaxial Seismometer Phase II  

Science Conference Proceedings (OSTI)

This report describes the preliminary design and the effort to date of Phase II of a Low Noise Borehole Triaxial Seismometer for use in networks of seismic stations for monitoring underground nuclear explosions. The design uses the latest technology of broadband seismic instrumentation. Each parameter of the seismometer is defined in terms of the known physical limits of the parameter. These limits are defined by the commercially available components, and the physical size constraints. A theoretical design is proposed, and a preliminary prototype model of the proposed instrument has been built. This prototype used the sensor module of the KS2000. The installation equipment (hole locks, etc.) has been designed and one unit has been installed in a borehole. The final design of the sensors and electronics and leveling mechanism is in process. Noise testing is scheduled for the last quarter of 2006.

Kerr, James D; McClung, David W

2006-11-06T23:59:59.000Z

244

Nonequilibrium noise in electrophoresis: the microion wind  

E-Print Network (OSTI)

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.

Suropriya Saha; Sriram Ramaswamy

2009-07-02T23:59:59.000Z

245

Frequency-dependent hydrodynamic inductance and the determination of the thermal and quantum noise of a superfluid gyroscope  

SciTech Connect

We reexamine mass flow in a superfluid gyroscope containing a superfluid Josephson weak link. We introduce a frequency-dependent hydrodynamic inductance to account for an oscillatory flow of the normal fluid component in the sensing loop. With this hydrodynamic inductance, we derive the thermal phase noise, and hence the thermal rotational noise of the gyroscope. We examine the thermodynamic stability of the system based on an analysis of the free energy. We derive a quantum phase noise, which is analogous to the zero-point motion of a simple harmonic oscillator. The configuration of the studied gyroscope is analogous to a conventional superconducting RF SQUID. We show that the gyroscope has very low intrinsic noise (1.9x10{sup -13} rad s{sup -1}/{radical}(Hz)), and it can potentially be applied to study general relativity, Earth science, and to improve global positioning systems (GPS)

Chui, Talso; Penanen, Konstantin [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

2005-04-01T23:59:59.000Z

246

Effect of personal and situational variables on noise annoyance: With special reference to implications for en route noise. Final report  

SciTech Connect

Over 680 publications from 282 social surveys of residents' reactions to environmental noise have been examined to locate 495 published findings on 26 topics concerning non-noise explanations for residents' reactions to environmental noise. This report (1) tabulates the evidence on the 26 response topics, (2) identifies the 495 findings, and (3) discusses the implications for en route noise assessment. After controlling for noise level, over half of the social survey evidence indicates that noise annoyance is not strongly affected by any of the nine demographic variables examined (age, sex, social status, income, education, homeownership, type of dwelling, length of residence, or receipt of benefits from the noise source), but is positively associated with each of the five attitudinal variables examined (a fear of danger from the noise source, a sensitivity towards noise generally, the belief that the authorities can control the noise, the awareness of non-noise impacts of the source, and the belief that the noise source is not important).

Not Available

1992-08-01T23:59:59.000Z

247

Detecting of Coal Gas Weak Signals Using Lyapunov Exponent under Strong Noise Background  

Science Conference Proceedings (OSTI)

In coal gas monitoring system, the early detecting of gas concentration is key technique for preventing the gas explosion because the coal gas signals are very weak under strong noise background in mining digging laneway. In this paper, the coal gas ... Keywords: Coal gas, weak signals, coal mine underground, Lyapunov exponent, Duffing chaotic oscillator

Ma Xian-Min

2013-01-01T23:59:59.000Z

248

Acoustic Noise Test Report for the Viryd CS8 Wind Turbine  

DOE Green Energy (OSTI)

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.

Roadman, J.; Huskey, A.

2013-07-01T23:59:59.000Z

249

Acoustic Noise Test Report for the SWIFT Wind Turbine in Boulder, CO  

DOE Green Energy (OSTI)

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.

Roadman, J.; Huskey, A.

2013-04-01T23:59:59.000Z

250

Acoustic Noise Test Report for the SWIFT Wind Turbine in Boulder, CO  

SciTech Connect

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.

Roadman, J.; Huskey, A.

2013-04-01T23:59:59.000Z

251

Thermophoresis of Brownian particles driven by coloured noise  

E-Print Network (OSTI)

The Brownian motion of microscopic particles is driven by the collisions with the molecules of the surrounding fluid. The noise associated with these collisions is not white, but coloured due, e.g., to the presence of hydrodynamic memory. The noise characteristic time scale is typically of the same order as the time over which the particle's kinetic energy is lost due to friction (inertial time scale). We demonstrate theoretically that, in the presence of a temperature gradient, the interplay between these two characteristic time scales can have measurable consequences on the particle long-time behaviour. Using homogenization theory, we analyse the infinitesimal generator of the stochastic differential equation describing the system in the limit where the two characteristic times are taken to zero; from this generator, we derive the thermophoretic transport coefficient, which, we find, can vary in both magnitude and sign, as observed in experiments. Furthermore, studying the long-term stationary particle distribution, we show that particles can accumulate towards the colder (positive thermophoresis) or the warmer (negative thermophoresis) regions depending on the dependence of their physical parameters and, in particular, their mobility on the temperature.

Scott Hottovy; Giovanni Volpe; Jan Wehr

2012-05-05T23:59:59.000Z

252

Neutron noise measurements at the Delphi subcritical assembly  

Science Conference Proceedings (OSTI)

The paper presents the results and evaluations of a comprehensive set of neutron noise measurements on the Delphi subcritical assembly of the Delft Univ. of Technology. The measurements investigated the effect of different source distributions (inherent spontaneous fission and {sup 252}Cf) and the position of the detectors applied (both radially and vertically). The evaluation of the measured data has been performed by the variance-to-mean ratio (VTMR, Feynman-{alpha}), the autocorrelation (ACF, Rossi-{alpha}) and the cross-correlation (CCF) methods. The values obtained for the prompt decay constant show a strong bias, which depends both on the detector position and on the source distribution. This is due to the presence of higher modes in the system. It has been observed that the {alpha} value fitted is higher when the detector is close to the boundary of the core or to the {sup 252}Cf point-source. The higher alpha-modes have also been observed by fitting functions describing two alpha-modes. The successful set of measurement also provides a good basis for further theoretical investigations including the Monte Carlo simulation of the noise measurements and the calculation of the alpha-modes in the Delphi subcritical assembly. (authors)

Szieberth, M.; Klujber, G. [Inst. of Nuclear Techniques, Budapest Univ. of Technology and Economics BME, Muegyetem rkp. 3-9, H-1111 Budapest (Hungary); Kloosterman, J. L.; De Haas, D. [Section Physics of Nuclear Reactors, Delft Univ. of Technology TUD, Mekelweg 15, 2629 JB Delft (Netherlands)

2012-07-01T23:59:59.000Z

253

Efficient hybrid shunt active power filter for improvement of power factor and harmonic suppression using MATLAB  

Science Conference Proceedings (OSTI)

Power quality management is the main problem that the industry is facing today. This is mainly affected by the generation of harmonics. The growing use of electronic equipment produces a large amount of harmonics in distribution systems because of non-sinusoidal ... Keywords: MATLAB 7.6, harmonic suppression, hybrid filter, power quality, shunt active power filter, total harmonic distortion

Jarupula Somlal

2011-03-01T23:59:59.000Z

254

Comparative evaluation of acoustical noise levels of Soleq Evcort EV and ICE (internal combustion engine) counterpart  

DOE Green Energy (OSTI)

The Idaho National Engineering Laboratory (INEL) evaluates Ev propulsion systems and components for the US Department of Energy (DOE) Electric and Hybrid Vehicle (EHV) Program. This paper describes an INEL study which compares the exterior and interior acoustic noise levels of an electric vehicle to its internal combustion engine (ICE) counterpart base vehicle, under various operating conditions. The electric vehicle was a converted 1988 Ford Escort station wagon, retrofitted with a DC electric powertrain developed by Soleq Corporation. A comparably-equipped gasoline-fueled ICE-powered Ford Escort station wagon provided the baseline acoustic noise levels with which to compare the electric vehicle. Measurements of the interior and exterior noise levels were obtained using a Bruel and Kjaer (B K) Type 2231 Modular Precision Sound Level Meter. The tests were conducted in accordance with applicable Society of Automotive Engineer's (SAE) standard practices at Chrysler's Arizona Proving Grounds in Wittmann, Arizona. The results indicate that radiated interior and exterior acoustic noise levels of the electric vehicle were noticeably quieter under acceleration and idly conditions. However, under constant speed operation the electric and the ICE exhibited essentially equivalent interior and exterior noise levels. 8 refs., 2 tabs.

MacDowall, R.D.

1990-01-01T23:59:59.000Z

255

Suppressed $B_s$ decays at CDF  

SciTech Connect

We review three recent results of the CDF collaboration on B{sub s}{sup 0} suppressed decays: the first search for CP-violation in the B{sub s}{sup 0} {yields} {phi}{phi} decay, where two CP-violating asymmetries expected to be zero in the Standard Model are measured, and the observation and the branching ratio measurements of B{sub s}{sup 0} {yields} J/{Psi} f{sub 0}(980) and B{sub s}{sup 0} {yields} J/{Psi} K{sup (*)} decays.

Dorigo, Mirco

2011-05-01T23:59:59.000Z

256

A high sensitivity ultralow temperature RF conductance and noise measurement setup  

SciTech Connect

We report on the realization of a high sensitivity RF noise measurement scheme to study small current fluctuations of mesoscopic systems at milli-Kelvin temperatures. The setup relies on the combination of an interferometric amplification scheme and a quarter-wave impedance transformer, allowing the measurement of noise power spectral densities with gigahertz bandwidth up to five orders of magnitude below the amplifier noise floor. We simultaneously measure the high frequency conductance of the sample by derivating a portion of the signal to a microwave homodyne detection. We describe the principle of the setup, as well as its implementation and calibration. Finally, we show that our setup allows to fully characterize a subnanosecond on-demand single electron source. More generally, its sensitivity and bandwidth make it suitable for applications manipulating single charges at GHz frequencies.

Parmentier, F. D.; Mahe, A.; Denis, A.; Berroir, J.-M.; Glattli, D. C.; Placais, B.; Feve, G. [Laboratoire Pierre Aigrain, Ecole Normale Superieure, CNRS UMR 8551, Universite P. et M. Curie, Universite D. Diderot 24, rue Lhomond, 75231 Paris Cedex 05 (France)

2011-01-15T23:59:59.000Z

257

Analysis of different methods to calculate electrochemical noise resistance using a three-electrode cell  

SciTech Connect

In a theoretical approach, the noise resistance parameter (R{sub n}) (in time domain) was deduced from an electric equivalent model proposed by Bertocci and coworkers for a cell with three identical electrodes. The voltage and current were measured. The R{sub n} and resistance of spectral noise (R{sub sn} and R{sub snO} [defined elsewhere]) were estimated for mild steel (MS) and stainless steel (SS) Type 304L (UNS S30403) electrodes immersed in four different solutions. The obtained results were converted into corrosion rate and finally compared with data measured with linear polarization resistance (LRP) and mass loss techniques. Electrochemical noise (EN) techniques had better agreement with other techniques in high corrosion rates. Furthermore, dispersed results were measured in low-activity systems.

Brusamarello, V.; Lago, A.; Franco, C.V.

2000-03-01T23:59:59.000Z

258

Interferometric at-wavelength flare characterization of EUV optical systems  

DOE Patents (OSTI)

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.

Naulleau, Patrick P. (Oakland, CA); Goldberg, Kenneth Alan (Berkeley, CA)

2001-01-01T23:59:59.000Z

259

Increasing LIGO sensitivity by feedforward subtraction of auxiliary length control noise  

E-Print Network (OSTI)

LIGO, the Laser Interferometer Gravitational-wave Observatory, has been designed and constructed to measure gravitational wave strain via differential arm length. The LIGO 4-km Michelson arms with Fabry-Perot cavities have auxiliary length control servos for suppressing Michelson motion of the beam-splitter and arm cavity input mirrors, which degrades interferometer sensitivity. We demonstrate how a post-facto pipeline called AMPS improves a data sample from LIGO Science Run~6 with feedforward subtraction. Dividing data into 1024-second windows, AMPS numerically fits filter functions representing the frequency-domain transfer functions from Michelson length channels into the gravitational-wave strain data channel for each window, then subtracts the filtered Michelson channel noise (witness) from the strain channel (target). In this paper we describe the algorithm, assess achievable improvements in sensitivity to astrophysical sources, and consider relevance to future interferometry.

Meadors, Grant David; Riles, Keith

2013-01-01T23:59:59.000Z

260

Increasing LIGO sensitivity by feedforward subtraction of auxiliary length control noise  

E-Print Network (OSTI)

LIGO, the Laser Interferometer Gravitational-wave Observatory, has been designed and constructed to measure gravitational wave strain via differential arm length. The LIGO 4-km Michelson arms with Fabry-Perot cavities have auxiliary length control servos for suppressing Michelson motion of the beam-splitter and arm cavity input mirrors, which degrades interferometer sensitivity. We demonstrate how a post-facto pipeline called AMPS improves a data sample from LIGO Science Run~6 with feedforward subtraction. Dividing data into 1024-second windows, AMPS numerically fits filter functions representing the frequency-domain transfer functions from Michelson length channels into the gravitational-wave strain data channel for each window, then subtracts the filtered Michelson channel noise (witness) from the strain channel (target). In this paper we describe the algorithm, assess achievable improvements in sensitivity to astrophysical sources, and consider relevance to future interferometry.

Grant David Meadors; Keita Kawabe; Keith Riles

2013-11-26T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Turbulence ingestion noise of open rotors  

E-Print Network (OSTI)

liners, which play a crucial role in specific tone reduction for turbofans, cannot of course be used to attenuate noise from these rotors. General Electric (GE) in the US began an in-house ‘UnDucted Fan’ (UDF) research programme in 1983 and also... ), has established ambitious targets for new aircraft entering service in 2020, compared to those entering service in 2000, of a 50% reduction in fuel consumption and CO2 emissions per passenger kilometre (of which 20%, that is just under half...

Robison, Rosalyn Aruna Venner

2012-04-10T23:59:59.000Z

262

Noise Traders, Market Sentiment, and Futures Price Behavior by  

E-Print Network (OSTI)

The noise trader sentiment model of De Long, Shleifer, Summers, and Waldmann (1990a) is applied to futures markets. The theoretical results predict that overly optimistic (pessimistic) noise traders result in market prices that are greater (less) than fundamental value. Thus, returns can be predicted using the level of noise trader sentiment. The null rational expectations hypothesis is tested against the noise trader alternative using a commercial market sentiment index as a proxy for noise trader sentiment. Fama-MacBeth cross-sectional regressions test if noise traders create a systematic bias in futures prices. The time-series predictability of futures returns using known sentiment levels is tested in a Cumby-Modest market timing framework and a more general causality specification. The empirical results lead to the following conclusions. First, there is no evidence that noise trader sentiment creates a systematic bias in futures prices. Second, predictable market returns using noise trader sentiment is not characteristic of futures markets in general. Third, futures market returns at weekly intervals are characterized by low-order positive autocorrelation with relatively small autoregressive parameters. In those instances where there is evidence of noise trader effects, it is at best limited to isolated markets and particular specifications. Noise Traders, Market Sentiment, and Futures Price Behavior

Dwight R. S; Scott H. Irwin; Raymond M. Leuthold; Dwight R. S; Ers Is Manager

1997-01-01T23:59:59.000Z

263

Sociopsychological factors affecting the human response to noise exposure  

SciTech Connect

Community noise is reported to be the most often mentioned undesirable neighborhood condition in a recent US Census survey. Understanding community response to noise involves the measurement of a number of complex acoustic and nonacoustic variables and establishing the chain of relationships between physical exposure, perception, annoyance, and acceptability responses and finally complaint behavior. The perceived loudness of a noise is the most important acoustic parameter influencing annoyance and complaints, and the simple dBA unit can be used to integrate spectral characteristics of complex sounds in community studies. Although energy averaging such as Leq or Ldn can be used to describe multiple noise exposures over time, the variable trade-off relationships between number and level of exposures are somewhat obscured by such summary measures. However, they are still the best available descriptors and, until more accurate ones are developed, can be used to measure community noise environments. Perception of an identical noise exposure can vary according to the physiological noise sensitivity of a person and the activity context in which the noise is heard. Although the acoustic quality of the noise itself usually explains about 10 to 25 per cent of the variability in annoyance responses, sociopsychological variables measured in field studies account for 35 to 50 per cent of the variations in human annoyance responses. Three of the most important nonacoustic factors are the connotative fear effects of the noise signal, the feeling that those responsible for the noise are misfeasant in not reducing the noise, and the feeling that harmful health effects are produced by the noise.

Borsky, P.N.

1979-08-01T23:59:59.000Z

264

Nonequilibrium chiral fluid dynamics including dissipation and noise  

E-Print Network (OSTI)

We present a consistent theoretical approach for the study of nonequilibrium effects in chiral fluid dynamics within the framework of the linear sigma model with constituent quarks. Treating the quarks as an equilibrated heat bath we use the influence functional formalism to obtain a Langevin equation for the sigma field. This allows us to calculate the explicit form of the damping coefficient and the noise correlators. For a selfconsistent derivation of both the dynamics of the sigma field and the quark fluid we have to employ the 2PI (two-particle irreducible) effective action formalism. The energy dissipation from the field to the fluid is treated in the exact formalism of the 2PI effective action where a conserved energy-momentum tensor can be constructed. We derive its form and comment on approximations generating additional terms in the energy-momentum balance of the entire system.

Marlene Nahrgang; Stefan Leupold; Christoph Herold; Marcus Bleicher

2011-05-03T23:59:59.000Z

265

Nonequilibrium chiral fluid dynamics including dissipation and noise  

E-Print Network (OSTI)

We present a consistent theoretical approach for the study of nonequilibrium effects in chiral fluid dynamics within the framework of the linear sigma model with constituent quarks. Treating the quarks as an equilibrated heat bath we use the influence functional formalism to obtain a Langevin equation for the sigma field. This allows us to calculate the explicit form of the damping coefficient and the noise correlators. For a selfconsistent derivation of both the dynamics of the sigma field and the quark fluid we have to employ the 2PI (two-particle irreducible) effective action formalism. The energy dissipation from the field to the fluid is treated in the exact formalism of the 2PI effective action where a conserved energy-momentum tensor can be constructed. We derive its form and comment on approximations generating additional terms in the energy-momentum balance of the entire system.

Nahrgang, Marlene; Herold, Christoph; Bleicher, Marcus

2011-01-01T23:59:59.000Z

266

Effects of Tidal Turbine Noise on Fish Hearing and Tissues - Draft Final Report - Environmental Effects of Marine and Hydrokinetic Energy  

Science Conference Proceedings (OSTI)

Snohomish Public Utility District No.1 plans to deploy two 6 meter OpenHydro tidal turbines in Admiralty Inlet in Puget Sound, under a FERC pilot permitting process. Regulators and stakeholders have raised questions about the potential effect of noise from the turbines on marine life. Noise in the aquatic environment is known to be a stressor to many types of aquatic life, including marine mammals, fish and birds. Marine mammals and birds are exceptionally difficult to work with for technical and regulatory reasons. Fish have been used as surrogates for other aquatic organisms as they have similar auditory structures. This project was funded under the FY09 Funding Opportunity Announcement (FOA) to Snohomish PUD, in partnership with the University of Washington - Northwest National Marine Renewable Energy Center, the Sea Mammal Research Unit, and Pacific Northwest National Laboratory. The results of this study will inform the larger research project outcomes. Proposed tidal turbine deployments in coastal waters are likely to propagate noise into nearby waters, potentially causing stress to native organisms. For this set of experiments, juvenile Chinook salmon (Oncorhynchus tshawytscha) were used as the experimental model. 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 was performed during FY 2011 to determine if noise generated by a 6-m diameter OpenHydro turbine might affect juvenile Chinook salmon hearing or cause barotrauma. Naturally spawning stocks of Chinook salmon that utilize Puget Sound are listed as threatened (http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/Chinook/CKPUG.cfm); the fish used in this experiment were hatchery raised and their populations are not in danger of depletion. 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). Experimental results indicate that non-lethal, 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.

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

2011-09-30T23:59:59.000Z

267

SEY_suppression_ELCOUD04.dvi  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 SLAC-TN-04-045 June 2004 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Suppression of the Effective Secondary Emission Yield for a Grooved Metal Surface G. Stupakov and M. Pivi

268

Pulse compression and prepulse suppression apparatus  

DOE Patents (OSTI)

A pulse compression and prepulse suppression apparatus (10) for time compressing the output of a laser (14). A pump pulse (46) is separated from a seed pulse (48) by a first polarized beam splitter (20) according to the orientation of a half wave plate (18). The seed pulse (48) is directed into an SBS oscillator (44) by two plane mirrors (22, 26) and a corner mirror (24), the corner mirror (24) being movable to adjust timing. The pump pulse (46) is directed into an SBS amplifier 34 wherein SBS occurs. The seed pulse (48), having been propagated from the SBS oscillator (44), is then directed through the SBS amplifier (34) wherein it sweeps the energy of the pump pulse (46) out of the SBS amplifier (34) and is simultaneously compressed, and the time compressed pump pulse (46) is emitted as a pulse output (52). A second polarized beam splitter (38) directs any undepleted pump pulse 58 away from the SBS oscillator (44).

Dane, C.B.; Hackel, L.A.; George, E.V.; Miller, J.L.; Krupke, W.F.

1993-11-09T23:59:59.000Z

269

Coating thermal noise of a finite-size cylindrical mirror  

E-Print Network (OSTI)

Thermal noise of a mirror is one of the limiting noise sources in the high precision measurement such as gravitational-wave detection, and the modeling of thermal noise has been developed and refined over a decade. In this paper, we present a derivation of coating thermal noise of a finite-size cylindrical mirror based on the fluctuation-dissipation theorem. The result agrees to a previous result with an infinite-size mirror in the limit of large thickness, and also agrees to an independent result based on the mode expansion with a thin-mirror approximation. Our study will play an important role not only to accurately estimate the thermal-noise level of gravitational-wave detectors but also to help analyzing thermal noise in quantum-measurement experiments with lighter mirrors.

Kentaro Somiya; Kazuhiro Yamamoto

2009-03-17T23:59:59.000Z

270

Suppression of a Nonpremixed Flame Stabilized by a ...  

Science Conference Proceedings (OSTI)

... Effects of Clutter on Performance of Fire Suppression Agents in Aircraft DIY Bays and Engine Nacelles, Report prepared for Booz, Allen and ...

2011-07-05T23:59:59.000Z

271

A spray-suppression model for turbulent combustion  

SciTech Connect

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.

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

2000-02-14T23:59:59.000Z

272

A spray-suppression model for turbulent combustion  

DOE Green Energy (OSTI)

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.

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

2000-02-14T23:59:59.000Z

273

Biological and cultural controls . . . Nonpesticide alternatives can suppress crop pests  

E-Print Network (OSTI)

alternatives can suppress crop pests Nicholas J. Mills Kentsuppression of major arthropod crop pests in California. Wevines, and ?eld and row crops. For example, a historic suc-

Mills, Nicholas J.; Daane, Kent M.

2005-01-01T23:59:59.000Z

274

A collaborative botnets suppression system based on overlay network  

Science Conference Proceedings (OSTI)

Botnets are extremely versatile programs used in many network attacks, such as sending large volumes of spam or launching Distributed Denial-of-Service DDoS attacks. Botnets can switch command-and-control servers automatically, which makes completely ...

Fuye Han; Zhen Chen; HongFeng Xu; Haopei Wang; Yong Liang

2012-04-01T23:59:59.000Z

275

Fire Suppression System Performance of Alternative Agents in ...  

Science Conference Proceedings (OSTI)

... development on nacelle fire protection followed, Klein (1950a) reported the results of the Jet Engine Fire Protection Program of the US Air Force. ...

1996-08-14T23:59:59.000Z

276

Green Noise or Green Value? Measuring the Effects of Environmental...  

NLE Websites -- All DOE Office Websites (Extended Search)

Plant EPIs Commercial Food Service About ENERGY STAR Partner Resources You are here Home Buildings & Plants Green Noise or Green Value? Measuring the Effects of...

277

Noise control technology for generator sets in enclosures  

Science Conference Proceedings (OSTI)

The health and life of human beings are affected by loud noise ..... error acoustic path was presented, and a feedback loud- speaker was used not only as the ...

278

Cell Voltage Noise Reduction Based on Wavelet in Aluminum ...  

Science Conference Proceedings (OSTI)

Presentation Title, Cell Voltage Noise Reduction Based on Wavelet in Aluminum ... cell voltage signals collected in aluminium electrolysis process are with high ...

279

Some noise control problems peculiar to nuclear generating facilities  

Science Conference Proceedings (OSTI)

The ability to confidently predict the noise environment in a nuclear generating facility presently under construction is complicated by the design constraints of physical layout

Robert A. Putnam

1977-01-01T23:59:59.000Z

280

Depth profiling ambient noise in the deep ocean  

E-Print Network (OSTI)

Acoustic Ambient Noise in the Ocean: Spectra and Sources,"and Osterhus, S. (1999). "Ocean Ambient Sound Instrumenta Subsurface Package," J. Atmos. Ocean. Tech. 16, 1118-1126.

Barclay, David Readshaw

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Assessing the Impacts of Reduced Noise Operations of Wind Turbines...  

NLE Websites -- All DOE Office Websites (Extended Search)

LBNL-3562E Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine Ben Hoen, Haftan Eckholdt, and Ryan...

282

Active control of fan noise and vortex shedding.  

E-Print Network (OSTI)

??[Truncated abstract] The subject of fan noise generating mechanisms and its control has been studied intensively over the past few decades as a result of… (more)

Wong, Yee-Jun

2004-01-01T23:59:59.000Z

283

Spin Noise Exchange in Coupled Alkali-Metal Vapors  

E-Print Network (OSTI)

The physics of spin exchange collisions has fueled a large number of discoveries in fundamental physics, chemistry and biology, and has led to several applications in medical imaging and nuclear magnetic resonance. We here report on the experimental observation and theoretical justification of a novel effect, the transfer of spin noise from one atomic species to another, through the mechanism of spin exchange. Essentially, we extend the foundational studies of spin exchange into the deeper layer of quantum fluctuations. The signature of spin noise exchange is an increase of the total spin noise power at low magnetic fields where the two-species spin noise resonances overlap.

A. T. Dellis; M. Loulakis; I. K. Kominis

2013-07-09T23:59:59.000Z

284

Inductively coupled plasma spectrometry: Noise characteristics of aerosols, application of generalized standard additions method, and Mach disk as an emission source  

SciTech Connect

This dissertation is focused on three problem areas in the performance of inductively coupled plasma (ICP) source. The noise characteristics of aerosols produced by ICP nebulizers are investigated. A laser beam is scattered by aerosol and detected by a photomultiplier tube and the noise amplitude spectrum of the scattered radiation is measured by a spectrum analyzer. Discrete frequency noise in the aerosol generated by a Meinhard nebulizer or a direct injection nebulizer is primarily caused by pulsation in the liquid flow from the pump. A Scott-type spray chamber suppresses white noise, while a conical, straight-pass spray chamber enhances white noise, relative to the noise seen from the primary aerosol. Simultaneous correction for both spectral interferences and matrix effects in ICP atomic emission spectrometry (AES) can be accomplished by using the generalized standard additions method (GSAM). Results obtained with the application of the GSAM to the Perkin-Elmer Optima 3000 ICP atomic emission spectrometer are presented. The echelle-based polychromator with segmented-array charge-coupled device detectors enables the direct, visual examination of the overlapping lines Cd (1) 228.802 nm and As (1) 228.812 nm. The slit translation capability allows a large number of data points to be sampled, therefore, the advantage of noise averaging is gained. An ICP is extracted into a small quartz vacuum chamber through a sampling orifice in a water-cooled copper plate. Optical emission from the Mach disk region is measured with a new type of echelle spectrometer equipped with two segmented-array charge-coupled-device detectors, with an effort to improve the detection limits for simultaneous multielement analysis by ICP-AES.

Shen, Luan

1995-10-06T23:59:59.000Z

285

The Quantum Governor: Automatic quantum control and reduction of the influence of noise without measuring  

E-Print Network (OSTI)

The problem of automatically protecting a quantum system against noise in a closed circuit is analyzed. A general scheme is developed built from two steps. At first, a distillation step is induced in which undesired components are removed to another degree of freedom of the system. Later a recovering step is employed which the system gains back its initial density. An Optimal-Control method is used to generate the distilling operator. The scheme is demonstrated by a simulation of a two level byte influenced by white noise. Undesired deviations from the target were shown to be reduced by at least two orders of magnitude on average. The relations between the quantum version of the classical Watt's Governor and the field of quantum information are also discussed.

Kallush, S

2005-01-01T23:59:59.000Z

286

The Quantum Governor: Automatic quantum control and reduction of the influence of noise without measuring  

E-Print Network (OSTI)

The problem of automatically protecting a quantum system against noise in a closed circuit is analyzed. A general scheme is developed built from two steps. At first, a distillation step is induced in which undesired components are removed to another degree of freedom of the system. Later a recovering step is employed which the system gains back its initial density. An Optimal-Control method is used to generate the distilling operator. The scheme is demonstrated by a simulation of a two level byte influenced by white noise. Undesired deviations from the target were shown to be reduced by at least two orders of magnitude on average. The relations between the quantum version of the classical Watt's Governor and the field of quantum information are also discussed.

S. Kallush; R. Kosloff

2005-11-21T23:59:59.000Z

287

Probabilistic Noise Identification and Data Cleaning  

E-Print Network (OSTI)

Real world data is never as perfect as we would like it to be and can often suffer from corruptions that may impact interpretations of the data, models created from the data, and decisions made based on the data. One approach to this problem is to identify and remove records that contain corruptions. Unfortunately, if only certain fields in a record have been corrupted then usable, uncorrupted data will be lost. In this paper we present LENS, an approach for identifying corrupted fields and using the remaining noncorrupted fields for subsequent modeling and analysis. Our approach uses the data to learn a probabilistic model containing three components: a generative model of the clean records, a generative model of the noise values, and a probabilistic model of the corruption process. We provide an algorithm for the unsupervised discovery of such models and empirically evaluate both its performance at detecting corrupted fields and, as one example application, the resulting improvement this gives to a classifier.

Jeremy Kubica; Andrew Moore

2002-01-01T23:59:59.000Z

288

Fossil Biodiversity: Red Noise Plus Signal  

E-Print Network (OSTI)

We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^8 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

Adrian L. Melott; Bruce S. Lieberman

2006-06-13T23:59:59.000Z

289

Fossil Biodiversity: Red Noise Plus Signal  

E-Print Network (OSTI)

We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^5 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

Melott, A L; Melott, Adrian L.; Lieberman, Bruce S.

2006-01-01T23:59:59.000Z

290

Sidelobe Suppression for Robust Beamformer Via the Mixed Norm Constraint  

Science Conference Proceedings (OSTI)

Applying a sparse constraint on the beam pattern has been suggested to suppress the sidelobe of the minimum variance distortionless response (MVDR) beamformer recently. To further improve the performance, we add a mixed norm constraint on the beam pattern. ... Keywords: Mixed norm constraint, Robust beamforming, Sidelobe suppression, Sparse constraint

Yipeng Liu; Qun Wan

2012-08-01T23:59:59.000Z

291

Modeling of combustion noise spectrum from turbulent premixed flames  

E-Print Network (OSTI)

Modeling of combustion noise spectrum from turbulent premixed flames Y. Liu, A. P. Dowling, T. D, Nantes, France 2321 #12;Turbulent combustion processes generate sound radiation due to temporal changes, this temporal correlation and its role in the modeling of combustion noise spectrum are studied by analyzing

Paris-Sud XI, Université de

292

Monitoring residential noise for prospective home owners and renters  

Science Conference Proceedings (OSTI)

Residential noise is a leading cause of neighborhood dissatisfaction but is difficult to quantify for it varies in intensity and spectra over time. We have developed a noise model and data representation techniques that prospective homeowners and renters ... Keywords: location-based services, mobile devices, sensors

Thomas Zimmerman; Christine Robson

2011-06-01T23:59:59.000Z

293

Noise threshold: Merzbow and the end of natural sound  

Science Conference Proceedings (OSTI)

When we ask what noise is, we would do well to remember that no single definition can function timelessly - this may well be the case with many terms, but one of the arguments of this essay is that noise is that which always fails to come into definition. ...

Paul Hegarty

2001-12-01T23:59:59.000Z

294

Theory of Neutron Noise in a Temporally Fluctuating Multiplying Medium  

E-Print Network (OSTI)

Theory of Neutron Noise in a Temporally Fluctuating Multiplying Medium Lénárd Pál KFKI Atomic of Technology, Department of Nuclear Engineering SE-41296 Göteborg, Sweden Received January 18, 2006 Accepted) and those in a fluctuating medium (power reactor noise) have been traditionally considered as two separate

Pázsit, Imre

295

Quantum Noise and Information in Quantum Search Algorithm  

Science Conference Proceedings (OSTI)

External influences in the form of quantum noise on Grover’s search algorithm are investigated. The study shows that the algorithm can be robust under such external dissipation. The effect of noise is described by a completely positive trace preserving map

D. Ellinas; Ch. Konstandakis

2004-01-01T23:59:59.000Z

296

Statement map: reducing web information credibility noise through opinion classification  

Science Conference Proceedings (OSTI)

On the Internet, users often encounter noise in the form of spelling errors or unknown words, however, dishonest, unreliable, or biased information also acts as noise that makes it difficult to find credible sources of information. As people come to ... Keywords: STATEMENT MAP, credibility analysis, discourse processing, opinion classification, semantic relation classification, structural alignment

Koji Murakami; Eric Nichols; Junta Mizuno; Yotaro Watanabe; Shouko Masuda; Hayato Goto; Megumi Ohki; Chitose Sao; Suguru Matsuyoshi; Kentaro Inui; Yuji Matsumoto

2010-10-01T23:59:59.000Z

297

Development of a 2-D 2-group neutron noise simulator  

E-Print Network (OSTI)

Development of a 2-D 2-group neutron noise simulator C. Demazie` re* Chalmers University of Technology, Department of Reactor Physics, SE-412 96 Go¨teborg, Sweden Received 10 May 2003; accepted 27 August 2003 Abstract In this paper, the development of a so-called neutron noise simulator is reported

Demazière, Christophe

298

A Method for Noise Removal of LIDAR Point Clouds  

Science Conference Proceedings (OSTI)

LiDAR can quickly and accurately obtain precision and high-density surface elevation data. In cooperation with high-precision GPS positioning technology and IMU attitude sensor, a typical noise removal algorithm of LIDAR point clouds based on FEA is ... Keywords: LIDAR, point clouds, noise removal, FEA

Huang Zuowei, Huang Yuanjiang, Huang Jie

2013-01-01T23:59:59.000Z

299

Indirect Combustion Noise: Experimental Investigation of the Vortex Sound Generation in a Choked  

E-Print Network (OSTI)

Indirect Combustion Noise: Experimental Investigation of the Vortex Sound Generation in a Choked-27 April 2012, Nantes, France 2315 #12;Combustion noise in gas turbines consists of direct noise related to the unsteady combustion process itself and indirect noise. As known, indirect noise is produced when entropy

Paris-Sud XI, Université de

300

Transmit Matched Filter And Transmit Wiener Filter For The Downlink Of FDD DS-CDMA Systems  

E-Print Network (OSTI)

We present space-time transmit filters for FDD DS-CDMA systems based on partial channel state information, i. e. we do not take into account the channel coefficients. Although the FDD transmit zero-forcing filter seems to be the most intuitive approach, we focus on the FDD transmit matched filter and the FDD transmit Wiener filter. Similarly to the respective receive filters and TDD transmit filters, the FDD matched filter maximizes the desired signal portion at the receiver and is optimum for low signal-to-noise-ratio scenarios, whereas the FDD transmit Wiener filter takes into account the noise power at the receiver and is therefore able to find an optimum trade-off between signal maximization and interference suppression. Additionally, we show that the FDD transmit matched filter is a type of Eigenbeamforming. The simulation results reveal the excellent performance of the two FDD transmit filters. The FDD transmit Wiener filter even outperforms the TDD transmit matched filter for high signalto -noise-ratio which is based on the instantaneous channel properties.

M. Joham; K. Kusume; W. Utschick; J. A. Nossek

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Further constraints on electron acceleration in solar noise storms  

E-Print Network (OSTI)

We reexamine the energetics of nonthermal electron acceleration in solar noise storms. A new result is obtained for the minimum nonthermal electron number density required to produce a Langmuir wave population of sufficient intensity to power the noise storm emission. We combine this constraint with the stochastic electron acceleration formalism developed by Subramanian & Becker (2005) to derive a rigorous estimate for the efficiency of the overall noise storm emission process, beginning with nonthermal electron acceleration and culminating in the observed radiation. We also calculate separate efficiencies for the electron acceleration -- Langmuir wave generation stage and the Langmuir wave -- noise storm production stage. In addition, we obtain a new theoretical estimate for the energy density of the Langmuir waves in noise storm continuum sources.

Prasad Subramanian; Peter A. Becker

2006-02-28T23:59:59.000Z

302

Sensing Applications of Fluctuations and Noise  

E-Print Network (OSTI)

Noise and time-dependent fluctuations are usually undesirable signals. However, they have many applications. This dissertation deals with two kinds of sensing applications of fluctuation and noise: soil bulk density assessment and bacterium sensing. The measurement of Vibration-Induced Conductivity Fluctuations (VICOF) provides information about the bulk density and other parameters of soils. Bulk density is the physical property of soils that is important to both the agriculture and construction industries. The traditional measurements of soil bulk density are often time-consuming, expensive or destructive. To determine the soil bulk density without the above drawbacks, the VICOF measurement scheme was proposed. The research of VICOF in this dissertation includes two parts: the initial phase of study and the new methods and their theory. In the initial phase of study, the simple experiments, theory, and simulations of VICOF were tested for relations between the soil bulk density, wetness, salinity, and the VICOF data. Then, new measurement arrangements and their theoretical models were proposed to improve the weaknesses of the initial approach (such as large scattering of data due to loose and heavy contacts) and to calculate the relationship between the measured signals and the electromechanical transport parameters of the soils. The bacterium sensing study in this dissertation was proposed to explore simple, practical, rapid, sensitive, specific, portable, and inexpensive ways to detect and recognize bacteria by Fluctuation-Enhanced Sensing (FES). One such potential way of bacterium sensing is to analyze their odor. The research of bacterium sensing also includes two parts: the initial phase of study and the new methods and their theory. The initial phase study was proposed to explore the possibility of detecting and identifying bacteria by sensing their odor via FES with commercial Taguchi sensors. Then the subsequently developed new methods and their theory provide a simple way to generate binary patterns with perfect reproducibility based on the spectral slopes in different frequency ranges at FES. This new type of signal processing and pattern recognition is implemented at the block diagram level using the building elements of analog circuitries and a few logic gates with total power consumption in the microWatts range.

Chang, Hung-Chih

2010-12-01T23:59:59.000Z

303

Low-Pass Filters to Suppress Inertial and Tidal Frequencies  

Science Conference Proceedings (OSTI)

A systematic way is given to design digital filters which allow clear separation of signals with periods of a few days from noise of higher frequency, particularly tidal and inertial. Several examples are given which pass little high-frequency ...

Rory O. R. Y. Thompson

1983-06-01T23:59:59.000Z

304

The world of quantum noise and the fundamental output process  

E-Print Network (OSTI)

A stationary theory of quantum stochastic processes of second order is outlined. It includes KMS processes in wide sense like the equilibrium finite temperature quantum noise given by the Planck's spectral formula. It is shown that for each stationary noise there exists a natural output process output process which is identical to the noise in the infinite temperature limit, and flipping with the noise if the time is reversed at finite temperature. A canonical Hilbert space representation of the quantum noise and the fundamental output process is established and a decomposition of their spectra is found. A brief explanation of quantum stochastic integration with respect to the input-output processes is given using only correlation functions. This provides a mathematical foundation for linear stationary filtering transformations of quantum stochastic processes. It is proved that the colored quantum stationary noise and its time-reversed version can be obtained in the second order theory by a linear nonadapted filtering of the standard vacuum noise uniquely defined by the canonical creation and annihilation operators on the spectrum of the input-output pair.

V. P. Belavkin; O. Hirota; R. Hudson

2005-10-04T23:59:59.000Z

305

Surge voltage suppression in residential power circuits  

Science Conference Proceedings (OSTI)

... Tran- sients in Low Voltage Supply Systems,'' The ... a high-voltage transformer for an oil furnace ... of service entrance SPD of 1960-1970 vintage were ...

2013-05-17T23:59:59.000Z

306

FIRE SUPPRESSING AGENT: A HALON ALTERNATIVE ...  

Science Conference Proceedings (OSTI)

... industry in closed-loop systems for automobiles. ... possible Steam inhalation and steam bum Approximately ... used in the trade and automobile industry ...

2011-10-27T23:59:59.000Z

307

1. Introduction 2. Fire suppression mechanisms  

Science Conference Proceedings (OSTI)

... may be similar to an outdoor fire, except for wind influence. b ... to installation of a water mist system in the turbine hoods of the offshore platforms of ...

2011-10-27T23:59:59.000Z

308

Adaptive discrete cosine transform for feedback active noise control  

Science Conference Proceedings (OSTI)

The theory and performance of adaptive discrete cosine transform filters for feedback active noise control (ANC) is examined. The discrete cosine transform filter is a realization of an FIR filter as the cascade of an all-zero FIR filter with a bank ... Keywords: FIR filter, IIR digital resonators bank, active noise control, adaptive discrete cosine transform filters, adaptive filter, all-zero FIR filter, discrete cosine transform filter, feedback active noise control, filter-X LMS implementation, frequency, magnitude coefficient, phase coefficient, single error microphone, single loudspeaker, transfer function

G. Coutu; M. Dignan

1995-10-01T23:59:59.000Z

309

Quantum noise eater for a single photonic qubit  

E-Print Network (OSTI)

We propose a quantum noise eater for a single qubit and experimentally verify its performance for recovery of a superposition carried by a dual-rail photonic qubit. We consider a case when only one of the rails (e.g., one of interferometric arms) is vulnerable to noise. A coherent but randomly arriving photon penetrating into this single rail causes a change of its state, which results in an error in a subsequent quantum information processing. We theoretically prove and experimentally demonstrate a conditional full recovery of the superposition by this quantum noise eater.

Miroslav Gavenda; Lucie ?elechovská; Miloslav Dušek; Radim Filip

2013-08-04T23:59:59.000Z

310

Numerical Investigation of Flow Induced Noise in a Simplified HVAC Duct with OpenFOAM.  

E-Print Network (OSTI)

?? Due to the growing demand for comfort, the noise generated by HVAC components should be considered by the designers. Flow induced noise is one… (more)

Wang, Cong

2013-01-01T23:59:59.000Z

311

Active Noise Control of an Insulated Box Fan using Feedforward and Feedback Control.  

E-Print Network (OSTI)

??In recent years, the active noise control methods are more attractive in reducing unwanted noise. Salient features of active control methods over passive control methods… (more)

Murthy, Muddala

2010-01-01T23:59:59.000Z

312

Feedback Applications in Active Noise Control for Small Axial Cooling Fans.  

E-Print Network (OSTI)

??Feedback active noise control (ANC) has been applied as a means of attenuating broadband noise from a small axial cooling fan. Such fans are used… (more)

Green, Matthew J 1978-

2006-01-01T23:59:59.000Z

313

Active Noise Control of a Centrifugal Fan Mounted in a Mock Laptop Enclosure.  

E-Print Network (OSTI)

??Noise from information technology (IT) equipment is a significant problem in today's modern society. Active Noise Control (ANC) has shown promise in reducing the effect… (more)

Esplin, John J.

2012-01-01T23:59:59.000Z

314

Estimating Suppression of Eddy Mixing by Mean Flows  

Science Conference Proceedings (OSTI)

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 height measurements from ...

Andreas Klocker; Raffaele Ferrari; Joseph H. LaCasce

2012-09-01T23:59:59.000Z

315

'Catch and Suppress' Control of Instabilities in High Performance  

NLE Websites -- All DOE Office Websites (Extended Search)

'Catch and Suppress' Control of Instabilities in High Performance 'Catch and Suppress' Control of Instabilities in High Performance Fusion Plasmas Fusion Energy Sciences (FES) FES Home About Research Facilities Science Highlights Benefits of FES Funding Opportunities Fusion Energy Sciences Advisory Committee (FESAC) News & Resources Contact Information Fusion Energy Sciences U.S. Department of Energy SC-24/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-4941 F: (301) 903-8584 E: sc.fes@science.doe.gov More Information » October 2012 'Catch and Suppress' Control of Instabilities in High Performance Fusion Plasmas Real time steering of microwave beams is used to suppress deleterious modes on DIII-D. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo Image courtesy of General Atomics

316

Nuclear Suppression of Dileptons at Large xF  

E-Print Network (OSTI)

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.

J. Cepila; J. Nemchik

2009-09-23T23:59:59.000Z

317

Efficiency of background suppression for arterial spin labeling  

E-Print Network (OSTI)

Arterial spin labeling (ASL), a technique developed for the measurement of local tissue perfusion with MRI, is heavily dependent on distinguishing irrelevant static tissue signal from the labeled blood. Background suppression ...

Garcia, Dairon, 1980-

2005-01-01T23:59:59.000Z

318

CMB quadrupole suppression. II. The early fast roll stage  

Science Conference Proceedings (OSTI)

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 e-folds N{sub tot}{approx}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{sup 2}. The suppression is much smaller for N{sub tot}>59, therefore if the observable suppression originates in the fast roll stage, there is the upper bound N{sub tot}{approx}59.

Boyanovsky, D.; Vega, H. J. de [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61, Avenue de l'Observatoire, 75014 Paris (France); LPTHE, Universite Pierre et Marie Curie (Paris VI) et Denis Diderot (Paris VII), Laboratoire Associe au CNRS UMR 7589, Tour 24, 5eme. etage, 4, Place Jussieu, 75252 Paris, Cedex 05 (France); Sanchez, N. G. [Observatoire de Paris, LERMA, Laboratoire Associe au CNRS UMR 8112, 61, Avenue de l'Observatoire, 75014 Paris (France)

2006-12-15T23:59:59.000Z

319

Reversible Electron Beam Heating for Suppression of Microbunching Instabilities at Free-Electron Lasers  

SciTech Connect

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.

Behrens, Christopher; /DESY; Huang, Zhirong; Xiang, Dao; /SLAC

2012-05-30T23:59:59.000Z

320

A genetically encoded, high-signal-to-noise maltose sensor  

SciTech Connect

We describe the generation of a family of high-signal-to-noise single-wavelength genetically encoded indicators for maltose. This was achieved by insertion of circularly permuted fluorescent proteins into a bacterial periplasmic binding protein (PBP), Escherichia coli maltodextrin-binding protein, resulting in a four-color family of maltose indicators. The sensors were iteratively optimized to have sufficient brightness and maltose-dependent fluorescence increases for imaging, under both one- and two-photon illumination. We demonstrate that maltose affinity of the sensors can be tuned in a fashion largely independent of the fluorescent readout mechanism. Using literature mutations, the binding specificity could be altered to moderate sucrose preference, but with a significant loss of affinity. We use the soluble sensors in individual E. coli bacteria to observe rapid maltose transport across the plasma membrane, and membrane fusion versions of the sensors on mammalian cells to visualize the addition of maltose to extracellular media. The PBP superfamily includes scaffolds specific for a number of analytes whose visualization would be critical to the reverse engineering of complex systems such as neural networks, biosynthetic pathways, and signal transduction cascades. We expect the methodology outlined here to be useful in the development of indicators for many such analytes.

Marvin, Jonathan S.; Schreiter, Eric R.; Echevarría, Ileabett M.; Looger, Loren L. (Puerto Rico); (HHMI)

2012-10-23T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Controlling excess noise in fiber optics continuous variables quantum key distribution  

E-Print Network (OSTI)

We describe a continuous variables coherent states quantum key distribution system working at 1550 nm, and entirely made of standard fiber optics and telecom components, such as integrated-optics modulators, couplers and fast InGaAs photodiodes. The setup is composed of an emitter randomly modulating a coherent state in the complex plane with a doubly Gaussian distribution, and a receiver based on a shot noise limited time-resolved homodyne detector. By using a reverse reconciliation protocol, the device can transfer a raw key rate up to 1 Mb/s, with a proven security against Gaussian or non-Gaussian attacks. The dependence of the secret information rate of the present fiber set-up is studied as a function of the line transmission and excess noise.

Jérôme Lodewyck; Thierry Debuisschert; Rosa Tualle-Brouri; Philippe Grangier

2005-11-10T23:59:59.000Z

322

Vacuum squeezing via polarization self-rotation and excess noise in hot Rb vapors  

E-Print Network (OSTI)

We present experimental and theoretical analysis of quantum fluctuation in a vacuum field in the presence of orthogonal linearly polarized pump field propagating through a Rb vapor cell. Previously reported theoretical and experimental studies provided somewhat contradictory conclusions regarding the possibility to observe the "squeezed vacuum" -- the reduction of vacuum fluctuations below standard quantum limit -- in this system. Here, using the D1 transitions of Rb in a cell without buffer as as an example, we demonstrate that vacuum squeezing is corrupted by incoherent processes (such as spontaneous emission, elastic scattering, etc.), and its observation is only possible in a specific small region of the experimental parameter space. Numerical simulations, in good agreement with the experiment, demonstrate that the two excited state hyperfine levels play a crucial role in the squeezing and excess noise production. The significant influence of far-detuned atoms on the field fluctuations at low noise freque...

Mikhailov, Eugeniy E; Noel, Thomas W; Novikova, Irina

2009-01-01T23:59:59.000Z

323

Inhomogeneous dynamic nuclear polarization and suppression of electron-polarization decay in a quantum dot  

E-Print Network (OSTI)

We investigate the dynamic nuclear polarization process by frequently injecting polarized electron spins into a quantum dot. Due to the suppression of the direct dipolar and indirect electron-mediated nuclear spin interactions, by the frequently injected electron spins, the analytical predictions under the independent spin approximation agree well with quantum numerical simulations. Our results show that the acquired nuclear polarization is highly inhomogeneous, proportional to the square of the local electron-nuclear hyperfine interaction constant, if the injection frequency is high. Utilizing the inhomogeneously polarized nuclear spins as an initial state, we further show that the electron-polarization decay time can be extended 100 times even at a relatively low nuclear polarization (<20%), without much suppression of the fluctuation of the Overhauser field. Our results lay the foundation for future investigations of the effect of DNP in more complex spin systems, such as double quantum dots and nitrogen vacancy centers in diamonds.

Na Wu; Wenkui Ding; Anqi Shi; Wenxian Zhang

2013-03-04T23:59:59.000Z

324

Additive Noise for Storm-Scale Ensemble Data Assimilation  

Science Conference Proceedings (OSTI)

An “additive noise” method for initializing ensemble forecasts of convective storms and maintaining ensemble spread during data assimilation is developed and tested for a simplified numerical cloud model (no radiation, terrain, or surface fluxes) ...

David C. Dowell; Louis J. Wicker

2009-05-01T23:59:59.000Z

325

Ambient addition : how to turn urban noise into music  

E-Print Network (OSTI)

As human civilization devises ever more powerful machines, living among them may become more difficult. We may find ourselves surrounded by incidentally created sounds and noises which are out of synchronization with our ...

Vawter, Noah (Noah Theodore)

2006-01-01T23:59:59.000Z

326

Ambient noise levels and reverberation times in Mississippi school rooms  

Science Conference Proceedings (OSTI)

Nine elementary school classrooms at three Mississippi public schools were selected at random for noise and reverberation time measures to monitor voluntary compliance with ANSI standard S12.60-2002 (Acoustical Performance Criteria

Edward L. Goshorn; Brett E. Kemker

2012-01-01T23:59:59.000Z

327

A Novel Low Noise Regenerative Divide-by-Four Circuit  

Science Conference Proceedings (OSTI)

... of a chip inductor of 10 nH in series with a chip capacitor of about 40 ... MHz quartz oscillator that was multiplied up to 400 MHz using ultra-low- noise ...

2002-10-15T23:59:59.000Z

328

Structural thermal noise in gram-scale mirror oscillators  

E-Print Network (OSTI)

The thermal noise associated with mechanical dissipation is a ubiquitous limitation to the sensitivity of precision experiments ranging from frequency stabilization to gravitational wave interferometry. We report on the ...

Neben, Abraham Richard

329

The reduction of supersonic jet noise using pulsed microjet injection  

E-Print Network (OSTI)

This thesis is concerned with the active control of supersonic jet noise using pulsed microjet injection at the nozzle exit. Experimental investigations were carried out using this control method on an ideally expanded ...

Ragaller, Paul Aaron

2007-01-01T23:59:59.000Z

330

Hybrid wing-body aircraft noise and performance assessment  

E-Print Network (OSTI)

Hybrid wing-body aircraft noise generation and boundary layer ingestion (BLI) performance trends with increased fan face Mach number inlet designs are investigated. The presented topics are in support of the NASA subsonic ...

Weed, Philip Andrew

2010-01-01T23:59:59.000Z

331

High efficiency photodetection below the quantum noise limit  

E-Print Network (OSTI)

Two low-noise, high quantum efficiency, high bandwidth photodetectors have constructed to form a balanced homodyne detector to detect squeezed light. The detectors have quantum efficiencies of 85% and 90%, a bandwidth of ...

Bullard, Elizabeth Caryn

2005-01-01T23:59:59.000Z

332

Evolutionary Multi-objective Ranking with Uncertainty and Noise  

Science Conference Proceedings (OSTI)

Real engineering optimisation problems are often subject to parameters whose values are uncertain or have noisy objective functions. Techniques such as adding small amounts of noise in order to identify robust solutions are also used. The process used ...

Evan Hughes

2001-03-01T23:59:59.000Z

333

Noise robust speech recognition applied to voice-driven wheelchair  

Science Conference Proceedings (OSTI)

Conventional voice-driven wheelchairs usually employ headset microphones that are capable of achieving sufficient recognition accuracy, even in the presence of surrounding noise. However, such interfaces require users to wear sensors such as a headset ...

Akira Sasou; Hiroaki Kojima

2009-01-01T23:59:59.000Z

334

The cost of noise reduction in commercial tilt rotor aircraft  

E-Print Network (OSTI)

The relationship between direct operating cost and departure noise annoyance was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various ...

Faulkner, Henry B.

1974-01-01T23:59:59.000Z

335

Noise-optimal capture for high dynamic range photography  

E-Print Network (OSTI)

Taking multiple exposures is a well-established approach both for capturing high dynamic range (HDR) scenes and for noise reduction. But what is the optimal set of photos to capture? The typical approach to HDR capture ...

Hasinoff, Samuel William

336

Noise reduction efforts for the ALS infrared beamlines  

E-Print Network (OSTI)

is being commissioned at the ALS that should help quietalso has links to the main ALS Infrared Website, where PDF’sNoise reduction efforts for the ALS infrared beamlines Tom

2003-01-01T23:59:59.000Z

337

Construction noise prediction and barrier optimization using special purpose simulation  

Science Conference Proceedings (OSTI)

Construction projects produce serious environmental pollution and great annoyance to the neighbouring community due to construction noise. This paper presents an application of the special purpose simulation (SPS) language using Simphony software to ...

Anupama Gannoruwa; Janaka Y. Ruwanpura

2007-12-01T23:59:59.000Z

338

RADIAL-BASED NOISE POWER ESTIMATION FOR WEATHER RADARS  

Science Conference Proceedings (OSTI)

A radar antenna intercepts thermal radiation from various sources including the ground, the sun, the sky, precipitation and man-made radiators. In the radar receiver, this external radiation produces noise that constructively adds to the receiver ...

Igor R. Ivi?; Christopher Curtis; Sebastián M. Torres

339

Noise to lubricate qubit transfer in a spin network  

E-Print Network (OSTI)

We consider quantum state transfer in a fully connected spin network, in which the results indicate that it is impossible to achieve high fidelity by free dynamics. However, the addition of certain kinds of noise can be helpful for this purpose. In fact, we introduce a model of Gaussian white noise affecting the spin-spin couplings (edges), except those linked to the input and output node, and prove that it enhances the fidelity of state transfer. The observed noise benefit is scale free as it applies to a quantum network of any size. The amount of the fidelity enhancement, depending on the noise strength as well as on the number of edges to which it is applied, can be so high as to take the fidelity close to one.

Morteza Rafiee; Cosmo Lupo; Stefano Mancini

2013-07-12T23:59:59.000Z

340

Real-time noise-robust speech detection  

E-Print Network (OSTI)

As part of the development of an autonomous forklift of the Agile Robotics Lab at MIT's Computer Science and Artificial Intelligence Lab (CSAIL), this thesis explores the effectiveness and application of various noise-robust ...

Luu, Kevin Y

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Noise-Induced Transitions in a Barotropic ?-Plane Channel  

Science Conference Proceedings (OSTI)

The concepts of multiplicative stochastic perturbations and noise-induced transitions are applied to a quasigeostrophic ?-plane model of barotropic flow over topography. The spectral three-component low-order representation of this configuration ...

Philip Sura

2002-01-01T23:59:59.000Z

342

On the Radiated Noise of the Autosub AUV  

E-Print Network (OSTI)

;Radiated noise of Container Ship 1 #12;FRV Scotia: Noise reduction measures t The engine is diesel: shipping, wind, rain & ice 10 20 30 40 50 60 70 80 90 100 110 120 130 140 10 100 1000 10000 100000 Centre/s wind Quartley Drizzle with 2 m/s windQuartley Wind 10 m/s Quartley Wind 2 m/sQuartley Wind 1 m

Griffiths, Gwyn

343

Aircraft Engine Noise Control as Viewed by the Engine Manufacturer  

Science Conference Proceedings (OSTI)

The aircraft engine manufacturer has been continually confronted with the factor of noise control in conjunction with the development and production testing of engines. The scope of this control activity has increased many fold during recent years as the result of the rapid growth in types and size of military power plants. Presented in this paper is a review of the over?all control procedure including typical noise sources

Donald M. Hazard

1953-01-01T23:59:59.000Z

344

Noise in non?premixed turbulent syngas flames  

Science Conference Proceedings (OSTI)

A turbulentsyngasflame may generateacoustic noise of high acoustic intensity in a combustion chamber. This may lead to the failure of construction components in a gas turbine engine in periods of the order of 1–100 hours. The research as described in the literature has almost exclusively been performed on the generation of noise in premixed methane or propane flames.Syngas fuel is a mixture of hydrogen and carbon monoxide

Sikke A. Klein; Jim B. W. Kok

1998-01-01T23:59:59.000Z

345

Update on Coal Mine Noise Model  

Science Conference Proceedings (OSTI)

Page 1. Network Modeling and Simulation of Mine Communication Systems N. Moayeri and M. Souryal May 12, 2011 Page 2. 2 ...

2011-06-17T23:59:59.000Z

346

Calculation of Fire Severity Factors and Fire Non-Suppression Probabilities For A DOE Facility Fire PRA  

Science Conference Proceedings (OSTI)

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.

Tom Elicson; Bentley Harwood; Jim Bouchard; Heather Lucek

2011-03-01T23:59:59.000Z

347

COMPLETE SUPPRESSION OF THE M=2/N-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D  

SciTech Connect

A271 COMPLETE SUPPRESSION OF THE M=2/N-1 NEOCLASSICAL TEARING MODE USING ELECTRON CYCLOTRON CURRENT DRIVE ON DIII-D. The first suppression of the important and deleterious m=2/n=1 neoclassical tearing mode (NTM) is reported using electron cyclotron current drive (ECCD) to replace the ''missing'' bootstrap current in the island O-point. Experiments on the DIII-D tokamak verify the maximum shrinkage of the m=2/n=1 island occurs when the ECCD location coincides with the q = 2 surface. The DIII-D plasma control system is put into search and suppress mode to make small changes in the toroidal field to find and lock onto the optimum position, based on real time measurements of dB{sub {theta}}/dt, for complete m=2/n=1 NTM suppression by ECCD. The requirements on the ECCD for complete island suppression are well modeled by the modified Rutherford equation for the DIII-D plasma conditions.

PETTY,CC; LAHAYE,LA; LUCE,TC; HUMPHREYS,DA; HYATT,AW; PRATER,R; STRAIT,EJ; WADE,MR

2003-03-01T23:59:59.000Z

348

Wave-particle duality in an environment with arbitrary white noise  

E-Print Network (OSTI)

The development of quantum technologies depends on investigating of the behavior of quantum systems in noisy environments, since complete isolation from its environment is impossible to achieve. In this paper we show that a wave-particle duality experiment performed in a system with an arbitrarily white noise level cannot be explained in classical terms, using hidden-variables models. In the light of our results, we analyze recent optical and NMR experiments and show that a loophole on non-locality is not fundamental.

J. G. Filgueiras; R. S. Sarthour; A. M. S. Souza; I. S. Oliveira; R. M. Serra; L. C. Céleri

2012-08-03T23:59:59.000Z

349

Non-linear addressing scheme for a lookup-based transformation function in a reconfigurable noise generator  

Science Conference Proceedings (OSTI)

Noise generation is used in several application domains, and each one of them has its own requirements for the statistical properties of the noise signal. This paper presents an approach that allows flexible noise generation based on reconfigurable logic. ... Keywords: LUT, addressing scheme, gauss, lookup-table, noise, noise generator, normal distribution, probability distribution function, transformation function, white noise

Elvio Dutra; Leandro Indrusiak; Manfred Glesner

2005-09-01T23:59:59.000Z

350

Acoustic Environment of Admiralty Inlet: Broadband Noise Measurements  

SciTech Connect

Admiralty Inlet has been selected as a potential tidal energy site. It is located near shipping lanes, is a highly variable acoustic environment, and is frequented by the highly endangered southern resident killer whale (SRKW). Resolving environmental impacts is the first step to receiving approval to deploy tidal turbines at Admiralty Inlet. Of particular concern is the potential for blade strike or other negative interactions between the SRKW and the tidal turbine. A variety of technologies including passive and active monitoring systems are being considered as potential tools to determine the presence of SRKW in the vicinity of the turbines. Broadband noise level measurements are critical for the determination of design and operation specifications of all marine and hydrokinetic energy capture technologies. Acoustic environment data at the proposed site was acquired at different depths using a cabled vertical line array (VLA) with four calibrated hydrophones. The sound pressure level (SPL) power spectrum density was estimated based on the fast Fourier transform. This study describes the first broadband SPL measurements for this site at different depths with frequency ranging from 10 kHz to 480 kHz in combination with other information. To understand the SPL caused by this bedload transport, three different pressure sensors with temperature and conductivity were also assembled on the VLA to measure the conditions at the hydrophone deployment depth. The broadband SPL levels at frequency ranges of 3 kHz to 7 kHz as a function of depth were estimated. Only the hydrophone at an average depth of 40 m showed the strong dependence of SPL with distance from the bottom, which was possibly caused by the cobbles shifting on the seabed. Automatic Identification System data were also studied to understand the SPL measurements.

Xu, Jinshan; Deng, Zhiqun; Martinez, Jayson J.; Carlson, Thomas J.; Myers, Joshua R.; Weiland, Mark A.; Jones, Mark E.

2011-09-30T23:59:59.000Z

351

Design and analysis of a recycled plastic noise barrier  

E-Print Network (OSTI)

This report documents a study of the feasibility of using soundwalls constructed of recycled plastics in place of conventional building materials. Important considerations in selecting materials used in this study include: environmental impact, acoustics, aesthetics, performance, safety, and cost. Various recycled materials were solicited from commercial manufacturers and subjected to a number of laboratory and field tests. These tests include three-point bending tests, impact hammer excitations, exposure to different types of weather, and experimentation with a variety of connections. Based on those results, several of the most promising materials were selected for construction of a full-scale installation of a test section of a soundwall at the Riverside Campus of Texas A&M University. This field section was monitored for a period of one year for response to environmental factors such as wind and exposure to ultraviolet radiation. Analysis of the field structure includes system identification of dynamic characteristics, finite element simulation, and acoustic performance. Acoustic results show that noise insertion loss of the prototype soundwall is exceptional. As for structural integrity, the prototype soundwall performed adequately over the course of the project with only a few members showing detrimental effects from the harsh thermal environment. System identification and experimental analysis of test data were successfully implemented and indicate that the soundwall is moderately wind sensitive. A finite element model of the soundwall was developed to simulate both static and dynamic response to loads. Using methods of modal superposition and random response, deflection was predicted for the top of the wall due to application of a strong wind event.

Esche, Steven Todd

1998-01-01T23:59:59.000Z

352

Experience with IBS-suppression lattice in RHIC  

SciTech Connect

An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-stars in the IPS. In this paper we report on the development, the tests and the performance of IBS-suppression lattice in RHIC, including the resulting increases in the peak and the average luminosity. We also report on our plans for future steps with the IBS suppression.

Litvinenko,V.N.; Luo, Y.; Ptitsyn, V.; Satogata, T.; Tepikian, S.; Bai, M.; Bruno, D.; Cameron, P.; Connolly, R.; Della Penna, A.; Drees, A.; Fedotov, A.; Ganetis, G.; Hoff, L.; Louie, W.; Malitsky, N.; Marr, G.; Marusic, A.; Montag, C.; Pilat, F.; Roser, T.; Trbojevic, D.; Tsoupas, N.

2008-06-23T23:59:59.000Z

353

Rotational suppression of the Tayler instability in stellar radiation zones  

E-Print Network (OSTI)

The study of the magnetic field in stellar radiation zones is an important topic in modern astrophysics because the magnetic field can play an important role in several transport phenomena such as mixing and angular momentum transport. We consider the influence of rotation on stability of a predominantly toroidal magnetic field in the radiation zone. We find that the effect of rotation on the stability depends on the magnetic configuration of the basic state. If the toroidal field increases sufficiently rapidly with the spherical radius, the instability cannot be suppressed entirely even by a very fast rotation although the strength of the instability can be significantly reduced. On the other hand, if the field increases slowly enough with the radius or decreases, the instability has a threshold and can be completely suppressed in rapidly rotating stars. We find that in the regions where the instability is entirely suppressed a particular type of magnetohydrodynamic waves may exist which are marginally stabl...

Bonanno, Alfio

2013-01-01T23:59:59.000Z

354

Ion energy recovery experiment based on magnetic electro suppression  

DOE Green Energy (OSTI)

A proof-of-principle experiment on direct recovery of residual hydrogen ions based on a magnetic electron suppression scheme is described. Ions extracted from a source plasma a few kilovolts above the ground potential (approx. 20 A) are accelerated to 40 keV by a negative potential maintained on a neutralizer gas cell. As the residual ions exit the gas cell, they are deflected from the neutral beam by a magnetic field that also suppresses gas cell electrons and then recovered on a ground-potential surface. Under optimum conditions, a recovery efficiency (the ratio of the net recovered current to the available full-energy ion current) of 80% +- 20% has been obtained. Magnetic suppression of the beam plasma electrons was rather easily achieved; however, handling the fractional-energy ions originating from molecular species (H/sub 2//sup +/ and H/sub 3//sup +/) proved to be extremely important to recovery efficiency.

Kim, J.; Stirling, W.L.; Dagenhart, W.K.; Barber, G.C.; Ponte, N.S.

1980-05-01T23:59:59.000Z

355

A new approach in signal processing for sodium boiling noise detection by probability density function estimates  

Science Conference Proceedings (OSTI)

The probability density function (pdf) method of noise signal processing has been investigated for its capability and quality in detecting sodium boiling noise. In an attempt to identify proper features of the pdf for sodium boiling noise detection, the segmented areas under the pdf curves have been found sensitive to sodium boiling noise. New approaches have been followed in selecting the feature threshold and achieving the targeted probabilities for false and missed sodium boiling noise detection.

Reddy, C.P.; Singh, O.P.; Vyjayanthi, R.K.; Prabhakar, R.

1988-03-01T23:59:59.000Z

356

Flare Noise Reduction Exxon Chemical- Baytown Olefins Plant: 1994 CMA Energy Efficiency Award for "Flare Noise Reduction" in the category of "Public Outreach/Plant Site"  

E-Print Network (OSTI)

Numerous community complaints were received because of what nearby residents perceived as excessive noise from BOP's elevated flares. Representatives from the Baytown Olefins Plant met with community residents to better understand their concerns. This qualitative data helped identify the flare noise problem to which BOP responded. BOP continued to solicit community feedback as various flare noise tests were conducted. Of particular concern to the community were low frequency rumbling noise and a higher frequency noise that resembles the sound of a jet plane passing overhead. To supplement the qualitative data received from the community, quantitative noise data was collected at various flaring conditions, wind conditions, and steam rates. Additional testing was performed to determine optimum steam rates for flaring events that could eliminate smoking and minimize noise. These tests concluded that reducing steam to the flare could reduce flare noise without jeopardizing smokeless operation. High intensity, low frequency rumbling noise (0-10 Hz), was rattling the windows and doors in the nearby community. It is typically generated by flame instability. Flame instability was occurring at BOP at fairly low flaring rates, and has been attributed to changes in the flare gas heating value and flare steam rates. Although a moderate amount of center steam lifts the flame off the top of the flare tip and prevents backburning (another source of flare noise), too much center steam makes a flame even less stable. This instability essentially causes a series of small explosions at the flare tip that generate low frequency noise. Combustion noise and steam injection noise contributed to the jet engine sound that was objectionable to the community. Steam injection noise increases as the amount of hydrocarbon burned in the flare increases, and noise increases as both hydrocarbon and steam injection increase. Although it is difficult to minimize the hydrocarbon to the flare, the steam to hydrocarbon ratio can be controlled to a minimum amount required for smokeless operation. Additionally, BOP can optimize the use of its two flares to reduce noise.

Bradham, S.; Stephan, R.

1996-04-01T23:59:59.000Z

357

Subtraction-noise projection in gravitational-wave detector networks  

SciTech Connect

In this paper, we present a successful implementation of a subtraction-noise projection method into a simple, simulated data analysis pipeline of a gravitational-wave search. We investigate the problem to reveal a weak stochastic background signal which is covered by a strong foreground of compact-binary coalescences. The foreground, which is estimated by matched filters, has to be subtracted from the data. Even an optimal analysis of foreground signals will leave subtraction noise due to estimation errors of template parameters which may corrupt the measurement of the background signal. The subtraction noise can be removed by a noise projection. We apply our analysis pipeline to the proposed future-generation space-borne Big Bang Observer mission which seeks for a stochastic background of primordial gravitational waves in the frequency range {approx}0.1 Hz--1 Hz covered by a foreground of black-hole and neutron-star binaries. Our analysis is based on a simulation code which provides a dynamical model of a time-delay interferometer network. It generates the data as time series and incorporates the analysis pipeline together with the noise projection. Our results confirm previous ad hoc predictions which say that the Big Bang Observer will be sensitive to backgrounds with fractional energy densities below {omega}=10{sup -16}.

Harms, Jan; Mahrdt, Christoph; Otto, Markus; Priess, Malte [Institut fuer Gravitationsphysik, Universitaet Hannover and Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Callinstrasse 38, 30167 Hannover (Germany)

2008-06-15T23:59:59.000Z

358

Viscoelastic Suppression of Gravity-Driven Counterflow Instability  

E-Print Network (OSTI)

Attempts to achieve ``top kill'' of actively flowing oil wells by insertion of dense drilling ``muds'', i.e., slurries of dense minerals, from above will fail if the Kelvin-Helmholtz instability in the gravity-driven counterflow produces turbulence that breaks up the denser fluid into small droplets. Here we estimate the droplet size to be sub-mm for fast flows and suggest the addition of a shear-thickening polymer to suppress turbulence. Laboratory experiments show a progression from droplet formation to complete turbulence suppression at the relevant high velocities, illustrating rich new physics accessible by using a shear-thickening liquid in gravity driven counter-streaming flows.

Beiersdorfer, P; Layne, D; Magee, E W

2010-01-01T23:59:59.000Z

359

An alternative model of jet suppression at RHIC energies  

E-Print Network (OSTI)

We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

2003-01-16T23:59:59.000Z

360

In plant partial noise enclosures for the mining industry  

SciTech Connect

The Physical and Toxic Agents Division of the Mine Safety and Health Administration`s Pittsburgh Safety and Health Technology Center has conducted three joint noise control demonstrations at dry milling operations. These demonstrations were conducted on a rod mill, a roller mill, and a ball mill, in order to survey a representative sample of the more commonly utilized types of milling equipment. The noise control concept that was demonstrated involved the construction of partial enclosures surrounding the mills and then adding acoustical materials within the enclosures to absorb the build up of acoustical energy. The results of this work illustrate the feasibility of this concept, the physical principle of creating an acoustical shadow, and the ability to closely predict the amount of absorptive material required to reduce the noise levels so as to comply with the Code of Federal Regulations (CFR), Title 30.

Kinevy, P.T.

1993-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Green Noise or Green Value? Measuring the Effects of Environmental  

NLE Websites -- All DOE Office Websites (Extended Search)

Noise or Green Value? Measuring the Effects of Noise or Green Value? Measuring the Effects of Environmental Certification on Office Values Secondary menu About us Press room Contact Us Portfolio Manager Login Facility owners and managers Existing buildings Commercial new construction Industrial energy management Small business Service providers Service and product providers Verify applications for ENERGY STAR certification Design commercial buildings Energy efficiency program administrators Commercial and industrial program sponsors Associations State and local governments Federal agencies Tools and resources Training In This Section Campaigns Commercial building design Communications resources Energy management guidance Financial resources Portfolio Manager Products and purchasing Recognition Research and reports Service and product provider (SPP) resources

362

Noise-cancelling quadrature magnetic position, speed and direction sensor  

DOE Patents (OSTI)

An array of three magnetic sensors in a single package is employed with a single bias magnet for sensing shaft position, speed and direction of a motor in a high magnetic noise environment. Two of the three magnetic sensors are situated in an anti-phase relationship (i.e., 180.degree. out-of-phase) with respect to the relationship between the other of the two sensors and magnetically salient target, and the third magnetic sensor is situated between the anti-phase sensors. The result is quadrature sensing with noise immunity for accurate relative position, speed and direction measurements.

Preston, Mark A. (Niskayuna, NY); King, Robert D. (Schenectady, NY)

1996-01-01T23:59:59.000Z

363

Community response to noise from a general aviation airport  

SciTech Connect

The paper provides relationships between noise level and response variables through an analysis of social survey and physical data collected around a small general aviation airport. The responses investigated included annoyance, activity interference, health effects, and non-noise effects of general aviation traffic, such as fear of crashes, air pollution, aircraft lights, house vibration, and television interference. Results indicate a much higher response than that predicted by Schultz (1978), e.g., at 30 NEF, Schultz predicts approximately 15% highly annoyed, compared with 28% in this study.

Birnie, S.E.; Hall, F.L.; Taylor, S.M.

1980-07-01T23:59:59.000Z

364

The quantum capacity of channels with arbitrarily correlated noise  

E-Print Network (OSTI)

We study optimal rates for quantum communication over a single use of a channel, which itself can correspond to a finite number of uses of a channel with arbitrarily correlated noise. The corresponding capacity is often referred to as the one-shot quantum capacity. In this paper, we prove bounds on the one-shot quantum capacity of an arbitrary channel. This allows us to compute the quantum capacity of a channel with arbitrarily correlated noise, in the limit of asymptotically many uses of the channel. In the memoryless case, we explicitly show that our results reduce to known expressions for the quantum capacity.

Francesco Buscemi; Nilanjana Datta

2009-02-02T23:59:59.000Z

365

Suppression of decoherence-induced diffusion in the quantum kicked rotor  

Science Conference Proceedings (OSTI)

We describe a method that allows transient suppression of spontaneous emission-induced diffusion in the atom-optics realization of the kicked rotor. The system is prepared in an initial state with a momentum distribution concentrated in an interval much sharper than the Brillouin zone; the measure of the momentum distribution is restricted to this interval of quasimomenta. Because most of the atoms undergoing decoherence processes fall outside this detection range and thus are not detected, the measured signal is effectively free of decoherence-induced diffusion effects.

Lepers, Maxence; Zehnle, Veronique; Garreau, Jean Claude [Laboratoire de Physique des Lasers, Atomes et Molecules, Universite Lille 1 Sciences et Technologies, CNRS, F-59655 Villeneuve d'Ascq Cedex (France)

2010-06-15T23:59:59.000Z

366

Power System Electromagnetic Compatibility  

Science Conference Proceedings (OSTI)

The potential for man-made electromagnetic interference has existed since the construction of the first electric power system. As the use of electricity expanded during the first few decades of the twentieth century, the number of sources of electromagnetic interference, as well as the number of receptors, burgeoned. With the proliferation of sources and receptors, the engineering study of electromagnetic interference--sometimes called radio noise, electrical noise, or radio-frequency interference--becam...

2000-12-19T23:59:59.000Z

367

Combustion Process in a Spark Ignition Engine: Dynamics and Noise Level Estimation  

E-Print Network (OSTI)

We analyse the experimental time series of internal pressure in a four cylinder spark ignition engine. In our experiment, performed for different spark advance angles, apart from usual cyclic changes of engine pressure we observed oscillations. These oscillations are with longer time scales ranging from one to several hundred engine cycles depending on engine working conditions. Basing on the pressure time dependence we have calculated the heat released per cycle. Using the time series of heat release to calculate the correlation coarse-grained entropy we estimated the noise level for internal combustion process. Our results show that for a smaller spark advance angle the system is more deterministic.

T. Kaminski; M. Wendeker; K. Urbanowicz; G. Litak

2003-12-28T23:59:59.000Z

368

Evidence for the suppressed decay B^- -> DK^-, D -> K^+?^-?^0  

E-Print Network (OSTI)

We report a study of the suppressed decay B^- -> DK^-, D -> K^+\\pi^-\\pi^0, where D denotes either a D^0 or a \\bar{D}^0 meson. The decay is sensitive to the CP-violating parameter \\phi_3. Using a data sample of 772 x 10^6 B\\bar{B} pairs collected at the \\Upsilon(4S) resonance with the Belle detector, we measure the ratio of branching fractions of the above suppressed decay to the favored decay B^- -> DK^-, D -> K^-\\pi^+\\pi^0. Our result is R_{DK} = [1.98 +/- 0.62(stat.) +/- 0.24(syst.)] x 10^{-2}, which indicates the first evidence of the signal for this suppressed decay with a significance of 3.2 standard deviations. We measure the direct CP asymmetry between the suppressed B^- and B^+ decays to be A_{DK} = 0.41 +/- 0.30 (stat.) +/- 0.05 (syst.). We also report measurements for the analogous quantities R_{D\\pi} and A_{D\\pi} for the decay B^- -> D\\pi^-, D -> K^+\\pi^-\\pi^0.

Belle Collaboration; M. Nayak; J. Libby; K. Trabelsi; I. Adachi; H. Aihara; D. M. Asner; T. Aushev; A. M. Bakich; A. Bala; P. Behera; K. Belous; V. Bhardwaj; G. Bonvicini; A. Bozek; M. Bra?ko; T. E. Browder; D. ?ervenkov; M. -C. Chang; P. Chang; V. Chekelian; A. Chen; B. G. Cheon; R. Chistov; I. -S. Cho; K. Cho; V. Chobanova; Y. Choi; D. Cinabro; J. Dalseno; M. Danilov; Z. Doležal; Z. Drásal; D. Dutta; S. Eidelman; S. Esen; H. Farhat; J. E. Fast; T. Ferber; V. Gaur; N. Gabyshev; S. Ganguly; R. Gillard; Y. M. Goh; B. Golob; J. Haba; H. Hayashii; Y. Horii; Y. Hoshi; W. -S. Hou; H. J. Hyun; T. Iijima; A. Ishikawa; T. Iwashita; I. Jaegle; T. Julius; D. H. Kah; E. Kato; D. Y. Kim; H. J. Kim; J. B. Kim; M. J. Kim; Y. J. Kim; K. Kinoshita; J. Klucar; B. R. Ko; P. Kodyš; S. Korpar; P. Krishnan; P. Križan; P. Krokovny; T. Kuhr; T. Kumita; A. Kuzmin; Y. -J. Kwon; S. -H. Lee; J. Li; Y. Li; L. Li Gioi; Y. Liu; D. Liventsev; P. Lukin; H. Miyake; R. Mizuk; G. B. Mohanty; A. Moll; T. Mori; N. Muramatsu; R. Mussa; Y. Nagasaka; M. Nakao; E. Nedelkovska; K. Negishi; C. Ng; N. K. Nisar; O. Nitoh; S. Ogawa; S. Okuno; Y. Onuki; P. Pakhlov; G. Pakhlova; C. W. Park; H. Park; T. K. Pedlar; M. Petri?; L. E. Piilonen; M. Ritter; M. Röhrken; A. Rostomyan; H. Sahoo; T. Saito; Y. Sakai; S. Sandilya; L. Santelj; T. Sanuki; V. Savinov; O. Schneider; G. Schnell; C. Schwanda; A. J. Schwartz; K. Senyo; O. Seon; M. E. Sevior; M. Shapkin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; Y. -S. Sohn; A. Sokolov; E. Solovieva; M. Stari?; M. Steder; Z. Suzuki; U. Tamponi; G. Tatishvili; Y. Teramoto; M. Uchida; T. Uglov; Y. Unno; S. Uno; P. Urquijo; S. E. Vahsen; C. Van Hulse; P. Vanhoefer; G. Varner; K. E. Varvell; M. N. Wagner; C. H. Wang; M. -Z. Wang; Y. Watanabe; K. M. Williams; E. Won; Y. Yamashita; S. Yashchenko; Y. Yusa; V. Zhilich; V. Zhulanov; A. Zupanc

2013-10-07T23:59:59.000Z

369

Comments on “Does Air Pollution Really Suppress Precipitation in Israel?”  

Science Conference Proceedings (OSTI)

Alpert et al. in a recent paper challenged the quantification of the suppression of orographic precipitation that was shown in two recent papers by Givati and Rosenfeld to occur in Israel. Their main claim was that the results were determined by ...

Amir Givati; Daniel Rosenfeld

2009-08-01T23:59:59.000Z

370

Dynamic Resource Allocation in Disaster Response: Tradeoffs in Wildfire Suppression  

E-Print Network (OSTI)

Dynamic Resource Allocation in Disaster Response: Tradeoffs in Wildfire Suppression Nada Petrovic1: Petrovic N, Alderson DL, Carlson JM (2012) Dynamic Resource Allocation in Disaster Response: Tradeoffs with the allocation of limited resources to mitigate the impact of natural disasters inspire fundamentally new

Carlson, Jean

371

Surge Suppression of Protection Equipment in UHV Substation  

Science Conference Proceedings (OSTI)

This paper analyses the producing mechanism of surge at protection equipment's ports, surge test of high level is done for signal ports, communication ports and power ports of specific protection equipment sample. Evaluation is accomplished for the methods ... Keywords: protection equipment, substation, surge suppression

Ma Haijie

2009-10-01T23:59:59.000Z

372

MOLECULAR MECHANISM OF SUPPRESSION OF NEOPLASTIC TRANSFORMATION BY LOW DOSES OF LOW LET RADIATION  

Science Conference Proceedings (OSTI)

We are currently funded (9/01-8/04) by the DOE Low Dose Radiation Research Program to examine mechanisms underlying the suppression of neoplastic transformation in vitro by low doses of low LET radiation. For the new studies proposed under Notice 04-21, we intend to follow up on our observation that upregulation of DNA repair may be an important factor and that its importance is dose-dependent. The experimental system will be the human hybrid cell neoplastic transformation assay that we are currently using. We propose to test the following hypothesis: Down-regulation of DNA dsb repair will abrogate the low dose suppression of neoplastic transformation. Using the technique of RNA silencing, it is proposed to test the effect of down-regulation of the two major DNA dsb repair pathways, homologous recombination (HR) and non-homologous end-joining (NHEJ), on the dose response relationship for neoplastic transformation. Based on prior studies, we predict that this will result in abrogation of the suppressive effect at doses in the range 1 to 10 cGy, but not at lower doses. The proposed experiments will also help address the question as to which of the two DNA repair pathways may be the most important in causing suppression of transformation. HR is a pathway that is predominant in S and G2 phase cells and is known to be less error-prone than the NHEJ pathway that is predominant in G1 phase. We hypothesize that down-regulation of HR will result in the most effective abrogation of suppression. An important component of this study will be the determination of the how abrogation of DNA dsb repair impacts the spontaneous transformation frequency, presumably a consequence of endogeneous DNA damage. Experiments will be carried out using partially synchronized populations of cells enriched for G1 and S/G2 respectively. In addition to the endpoint of neoplastic transformation the impact of down-regulation of HR and NHEJ on the formation and disappearance of the DNA dsb marker, gamma-H2AX, will be studied.

J.LESIE REDPATH, PH.D.

2011-03-29T23:59:59.000Z

373

Inverse determination of the penalty parameter in penalized weighted least-squares algorithm for noise reduction of low-dose CBCT  

Science Conference Proceedings (OSTI)

Purpose: A statistical projection restoration algorithm based on the penalized weighted least-squares (PWLS) criterion can substantially improve the image quality of low-dose CBCT images. The performance of PWLS is largely dependent on the choice of the penalty parameter. Previously, the penalty parameter was chosen empirically by trial and error. In this work, the authors developed an inverse technique to calculate the penalty parameter in PWLS for noise suppression of low-dose CBCT in image guided radiotherapy (IGRT). Methods: In IGRT, a daily CBCT is acquired for the same patient during a treatment course. In this work, the authors acquired the CBCT with a high-mAs protocol for the first session and then a lower mAs protocol for the subsequent sessions. The high-mAs projections served as the goal (ideal) toward, which the low-mAs projections were to be smoothed by minimizing the PWLS objective function. The penalty parameter was determined through an inverse calculation of the derivative of the objective function incorporating both the high and low-mAs projections. Then the parameter obtained can be used for PWLS to smooth the noise in low-dose projections. CBCT projections for a CatPhan 600 and an anthropomorphic head phantom, as well as for a brain patient, were used to evaluate the performance of the proposed technique. Results: The penalty parameter in PWLS was obtained for each CBCT projection using the proposed strategy. The noise in the low-dose CBCT images reconstructed from the smoothed projections was greatly suppressed. Image quality in PWLS-processed low-dose CBCT was comparable to its corresponding high-dose CBCT. Conclusions: A technique was proposed to estimate the penalty parameter for PWLS algorithm. It provides an objective and efficient way to obtain the penalty parameter for image restoration algorithms that require predefined smoothing parameters.

Wang, Jing; Guan, Huaiqun; Solberg, Timothy [Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas 75390 (United States); Department of Radiation oncology, Sylvester Comprehensive Cancer Center, University of Miami Medical School, Florida 33136 (United States); Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, Texas 75390 (United States)

2011-07-15T23:59:59.000Z

374

The study of effects of small perturbations on chaotic systems  

SciTech Connect

This report discusses the following topics on small perturbations on chaotic systems: controlling chaos; shadowing and noise reduction; chaotic scattering; random maps; magnetic dynamo; and aids transmission. (LSP)

Grebogi, C. (Maryland Univ., College Park, MD (USA). Lab. for Plasma Research); Yorke, J.A. (Maryland Univ., College Park, MD (USA). Inst. for Physical Science and Technology)

1990-12-01T23:59:59.000Z

375

Low Dose Suppression of Neoplastic Transformation in Vitro  

SciTech Connect

This grant was to study the low dose suppression of neoplastic transformation in vitro and the shape of the dose-response curve at low doses and dose-rates of ionizing radiation. Previous findings had indicated a suppression of transformation at dose <10cGy of low-LET radiation when delivered at high dose-rate. The present study indicates that such suppression extends out to doses in excess of 100cGy when the dose (from I-125 photons) is delivered at dose-rates as low as 0.2 mGy/min and out to in excess of {approx}25cGy the highest dose studied at the very low dose-rate of 0.5 mGy/day. We also examined dose-rate effects for high energy protons (which are a low-LET radiation) and suppression was evident below {approx}10cGy for high dose-rate delivery and at least out to 50cGy for low dose-rate (20cGy/h) delivery. Finally, we also examined the effect of low doses of 1 GeV/n iron ions (a high-LET radiation) delivered at high dose-rate on transformation at low doses and found a suppression below {approx}10cGy that could be attributable to an adaptive response in bystander cells induced by the associated low-LET delta rays. These results have implications for cancer risk assessment at low doses.

John Leslie Redpath

2012-05-01T23:59:59.000Z

376

Non-Markovian stochastic Schrödinger equations: Generalization to real-valued noise using quantum measurement theory  

E-Print Network (OSTI)

Do stochastic Schr\\"odinger equations, also known as unravelings, have a physical interpretation? In the Markovian limit, where the system {\\em on average} obeys a master equation, the answer is yes. Markovian stochastic Schr\\"odinger equations generate quantum trajectories for the system state conditioned on continuously monitoring the bath. For a given master equation, there are many different unravelings, corresponding to different sorts of measurement on the bath. In this paper we address the non-Markovian case, and in particular the sort of stochastic \\sch equation introduced by Strunz, Di\\' osi, and Gisin [Phys. Rev. Lett. 82, 1801 (1999)]. Using a quantum measurement theory approach, we rederive their unraveling which involves complex-valued Gaussian noise. We also derive an unraveling involving real-valued Gaussian noise. We show that in the Markovian limit, these two unravelings correspond to heterodyne and homodyne detection respectively. Although we use quantum measurement theory to define these unravelings, we conclude that the stochastic evolution of the system state is not a true quantum trajectory, as the identity of the state through time is a fiction.

Jay Gambetta; H. M. Wiseman

2002-02-20T23:59:59.000Z

377

Low-noise detector and amplifier design for 100 ns direct detection CO{sub 2} LIDAR receiver  

SciTech Connect

The development and test results of a prototype detector/amplifier design for a background limited, pulsed 100 ns, 10--100 kHz repetition rate LIDAR/DIAL receiver system are presented. Design objectives include near-matched filter detection of received pulse amplitude and round trip time-of-flight, and the elimination of excess correlated detector/amplifier noise for optimal pulse averaging. A novel pole-zero cancellation amplifier, coupled with a state-of-the-art SBRC (Santa Barbara Research Center) infrared detector was implemented to meet design objectives. The pole-zero cancellation amplifier utilizes a tunable, pseudo-matched filter technique to match the width of the laser pulse to the shaping time of the filter for optimal SNR performance. Low frequency correlated noise, (l/f and drift noise) is rejected through a second order high gain feedback loop. The amplifier also employs an active detector bias stage minimizing detector drift. Experimental results will be provided that demonstrate near-background limited, 100 ns pulse detection performance given a 8.5--11.5 {micro}m (300 K B.B.) radiant background, with the total noise floor spectrally white for optimal pulse averaging efficiency.

Cafferty, M.M.; Cooke, B.J.; Laubscher, B.E.; Olivas, N.L.; Fuller, K.

1997-06-01T23:59:59.000Z

378

Measurement of thermal noise in multilayer coatings with optimized layer thickness  

Science Conference Proceedings (OSTI)

A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise for a prescribed reflectivity. Coatings with the layer thicknesses optimized to minimize thermal noise could be useful in future generation interferometric gravitational wave detectors where coating thermal noise is expected to limit the sensitivity of the instrument. We present the results of direct measurements of the thermal noise of a standard quarter-wavelength coating and a low noise optimized coating. The measurements indicate a reduction in thermal noise in line with modeling predictions.

Villar, Akira E.; Black, Eric D.; DeSalvo, Riccardo; Libbrecht, Kenneth G.; Michel, Christophe; Morgado, Nazario; Pinard, Laurent; Pinto, Innocenzo M.; Pierro, Vincenzo; Galdi, Vincenzo; Principe, Maria; Taurasi, Ilaria [LIGO Laboratory, California Institute of Technology, Mail Code 264-33, Pasadena, California 91125 (United States); Laboratoire des Materiaux Avances, Universite Claude Bernard Lyon 1, CNRS/IN2P3, Villeurbaune (France); Waves Group, University of Sannio at Benevento, Benevento, Italy, INFN and LSC (Italy)

2010-06-15T23:59:59.000Z

379

Worker noise exposures from diesel and electric surface coal mining machinery  

Science Conference Proceedings (OSTI)

comparative study of noise produced from diesel and electric mining machinery in an opencast coal mine was made. It was found that the diesel machines produced higher environmental noise than the electric machines. The projected and measured operator's noise dose for 8-hour also showed that the diesel machines produced higher noise than the electric machines. The recorded sound levels and the noise dose for different machines and the crusher house were compared with the regulatory limits. With electric drill machines, drilling in hard rock produced higher noise levels than drilling in soft rock. This can be used to characterize the rock for blast designs.

Roy, S.; Adhikari, G.R.

2007-09-15T23:59:59.000Z

380

Cultural noise in EM prospecting for geothermal resources. Final report  

DOE Green Energy (OSTI)

Numerical analysis tools are used to characterize the fields reradiated by cultural scatterers like powerlines, pipelines and fences. These fields are then compared to the returns expected from deeply buried targets and suggestions are made for methods to identify and remove cultural noise from survey data.

Merewether, D.E.; Cox, R.W.; Pate, R.C.

1981-02-05T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Long correlation Gaussian random fields: Parameter estimation and noise reduction  

Science Conference Proceedings (OSTI)

In this paper, a parametric model for Gaussian random fields (GRFs) with long-correlation feature, namely the long correlation GRF (LC-GRF), is studied. Important properties of the model are derived and used for developing new parameter estimation algorithms ... Keywords: Expectation--maximization (EM) algorithm, Gaussian random fields (GRF), Maximum likelihood estimation (MLE), Noise reduction, Wiener filter

C. F. Caiafa; A. N. Proto; E. E. Kuruo?lu

2007-07-01T23:59:59.000Z

382

VULNERABILITY OF BLUETOOTH TO IMPULSIVE NOISE IN ELECTRICITY TRANSMISSION SUBSTATIONS  

E-Print Network (OSTI)

VULNERABILITY OF BLUETOOTH TO IMPULSIVE NOISE IN ELECTRICITY TRANSMISSION SUBSTATIONS S A Bhattil environment of an Electricity transmission substation environment is modelled as a Symmetric Alpha Stable of an electricity transmission substation. I. INTRODUCTION In industrial environments, Supervisor Control and Data

Atkinson, Robert C

383

Discriminating between a Stochastic Gravitational Wave Background and Instrument Noise  

E-Print Network (OSTI)

The detection of a stochastic background of gravitational waves could significantly impact our understanding of the physical processes that shaped the early Universe. The challenge lies in separating the cosmological signal from other stochastic processes such as instrument noise and astrophysical foregrounds. One approach is to build two or more detectors and cross correlate their output, thereby enhancing the common gravitational wave signal relative to the uncorrelated instrument noise. When only one detector is available, as will likely be the case with the Laser Interferometer Space Antenna (LISA), alternative analysis techniques must be developed. Here we show that models of the noise and signal transfer functions can be used to tease apart the gravitational and instrument noise contributions. We discuss the role of gravitational wave insensitive "null channels" formed from particular combinations of the time delay interferometry, and derive a new combination that maintains this insensitivity for unequal arm length detectors. We show that, in the absence of astrophysical foregrounds, LISA could detect signals with energy densities as low as $\\Omega_{\\rm gw} = 6 \\times 10^{-13}$ with just one month of data. We describe an end-to-end Bayesian analysis pipeline that is able to search for, characterize and assign confidence levels for the detection of a stochastic gravitational wave background, and demonstrate the effectiveness of this approach using simulated data from the third round of Mock LISA Data Challenges.

Matthew R. Adams; Neil J. Cornish

2010-02-05T23:59:59.000Z

384

Assessing the Impacts of Reduced Noise Operations of Wind Turbines  

E-Print Network (OSTI)

i LBNL-3562E Assessing the Impacts of Reduced Noise Operations of Wind Turbines on Neighbor Operations of Wind Turbines on Neighbor Annoyance: A Preliminary Analysis in Vinalhaven, Maine Prepared from the turbines is unwelcome and annoying. Fox Islands Wind, the owner of the facility, hypothesized

385

Recursive Wang tiles for real-time blue noise  

Science Conference Proceedings (OSTI)

Well distributed point sets play an important role in a variety of computer graphics contexts, such as anti-aliasing, global illumination, halftoning, non-photorealistic rendering, point-based modeling and rendering, and geometry processing. In this ... Keywords: Poisson disk distribution, Wang tiles, anti-aliasing, blue noise, non-periodic tiling, object positioning, sampling, stippling, texture synthesis

Johannes Kopf; Daniel Cohen-Or; Oliver Deussen; Dani Lischinski

2006-07-01T23:59:59.000Z

386

Correcting Specular Noise in Multiple Images of Photographed Documents  

Science Conference Proceedings (OSTI)

Portable digital cameras have become omnipresent. Their low-lost, simplicity to use, flexibility, and good quality images have widened their applicability far beyond their original purpose of taking personal photos. Every day people discover new uses ... Keywords: specular noise, photographed documents, multiple images

Ednardo Mariano; Rafael Dueire Lins; Gabriel de. Franca Pereira e. Silva; Jian Fan; Peter Majewicz; Marcelo Thielo

2011-09-01T23:59:59.000Z

387

Shear wave velocities from noise correlation at local scale  

Science Conference Proceedings (OSTI)

Cross correlations of ambient seismic noise recordings have been studied to infer shear seismic velocities with depth. Experiments have been done in the crowded and noisy historical centre of Napoli over inter-station distances from 50 m to about 400 m, whereas active seismic spreadings are prohibitive, even for just one receiver. Group velocity dispersion curves have been extracted with FTAN method from the noise cross correlations and then the non linear inversion of them has resulted in Vs profiles with depth. The information of near by stratigraphies and the range of Vs variability for samples of Neapolitan soils and rocks confirms the validity of results obtained with our expeditious procedure. Moreover, the good comparison of noise H/V frequency of the first main peak with 1D and 2D spectral amplifications encourages to continue experiments of noise cross-correlation. If confirmed in other geological settings, the proposed approach could reveal a low cost methodology to obtain reliable and detailed Vs velocity profiles.

De Nisco, G.; Nunziata, C. [Dipartimento di Scienze della Terra, Univ. Napoli Federico II (Italy); Vaccari, F. [Dipartimento di Scienze della Terra, Univ. Trieste (Italy); Panza, G. F. [Dipartimento di Scienze della Terra, Univ. Trieste (Italy); The Abdus Salam International Center for Theoretical Physics, ESP-SAND Group, Trieste (Italy)

2008-07-08T23:59:59.000Z

388

Quantum noise in a nano mechanical Duffing resonator  

E-Print Network (OSTI)

We determine the small signal gain and noise response of an amplifier based on the nonlinear response of a quantum nanomechanical resonator. The resonator is biased in the nonlinear regime by a strong harmonic bias force and we determine the response to a small additional driving signal detuned with respect to the bias force.

E. Babourina-Brooks; A. Doherty; G. J. Milburn

2008-04-22T23:59:59.000Z

389

Injection monitoring with seismic arrays and adaptive noise cancellation  

DOE Green Energy (OSTI)

Although the application of seismic methods, active and passive, to monitor in-situ reservoir stimulation processes is not new, seismic arrays and array processing technology coupled with a new noise cancellation method has not been attempted. Successful application of seismic arrays to passively monitor in-situ reservoir stimulation processes depends on being able to sufficiently cancel the expected large amplitude background seismic noise typical of an oil or geothermal production environment so that small amplitude seismic signals occurring at depth can be detected and located. This report describes the results of a short field experiment conducted to test both the application of seismic arrays for in-situ reservoir stimulation monitoring and the active noise cancellation technique in a real reservoir production environment. Although successful application of these techniques to in-situ reservoir stimulation monitoring would have the greatest payoff in the oil industry, the proof-of-concept field experiment site was chosen to be the Geysers geothermal field in northern California. This site was chosen because of known high seismicity rates, a relatively shallow production depth, cooperation and some cost sharing the UNOCAL Oil Corporation, and the close proximity of the site to LLNL. The body of this report describes the Geysers field experimental configuration and then discusses the results of the seismic array processing and the results of the seismic noise cancellation followed by a brief conclusion. 2 refs., 11 figs.

Harben, P.E.; Harris, D.B.; Jarpe, S.P.

1991-01-01T23:59:59.000Z

390

QUANTUM FILTERING OF MARKOV SIGNALS WITH WHITE QUANTUM NOISE  

E-Print Network (OSTI)

QUANTUM FILTERING OF MARKOV SIGNALS WITH WHITE QUANTUM NOISE V. P. BELAVKIN Abstract. Time-continuous non-anticipating quantum processes of nonde- molition measurements are introduced as the dynamical-valued probability measures on the trajectory spaces of the gener- alized temporal observations in quantum open

Belavkin, Viacheslav P.

391

Mitigating Geomagnetic Noise in Airborne Magnetic Surveys using GPS  

E-Print Network (OSTI)

Mitigating Geomagnetic Noise in Airborne Magnetic Surveys using GPS S. Skone Department, a limiting factor remains ­ the small-amplitude variations caused by geomagnetic pulsations arising from the correlation of TEC variations with geomagnetic pulsations. Variations in TEC during intervals of Pc 3

Calgary, University of

392

Aero?acoustic noise generation of a lawnmower deck  

Science Conference Proceedings (OSTI)

Sound power and dynamic pressure measurements were used to identify where noise is generated by a single spindle lawnmower deck. The sound powermeasurements were performed with different blades and deck profiles to quantify the overall levels. An electric motor was used to turn the blade

Chris Peak

2007-01-01T23:59:59.000Z

393

The application of expansion foam on liquefied natural gas (LNG) to suppress LNG vapor and LNG pool fire thermal radiation  

E-Print Network (OSTI)

Liquefied Natural Gas (LNG) hazards include LNG flammable vapor dispersion and LNG pool fire thermal radiation. A large LNG pool fire emits high thermal radiation thus preventing fire fighters from approaching and extinguishing the fire. One of the strategies used in the LNG industry and recommended by federal regulation National Fire Protection Association (NFPA) 59A is to use expansion foam to suppress LNG vapors and to control LNG fire by reducing the fire size. In its application, expansion foam effectiveness heavily depends on application rate, generator location, and LNG containment pit design. Complicated phenomena involved and previous studies have not completely filled the gaps increases the needs for LNG field experiments involving expansion foam. In addition, alternative LNG vapor dispersion and pool fire suppression methodology, Foamglas® pool fire suppression (PFS), is investigated as well. This dissertation details the research and experiment development. Results regarding important phenomena are presented and discussed. Foamglas® PFS effectiveness is described. Recommendations for advancing current guidelines in LNG vapor dispersion and pool fire suppression methods are developed. The gaps are presented as the future work and recommendation on how to do the experiment better in the future. This will benefit LNG industries to enhance its safety system and to make LNG facilities safer.

Suardin, Jaffee Arizon

2008-08-01T23:59:59.000Z

394

Benchmarking the effects of operating system interference on extreme-scale parallel machines  

Science Conference Proceedings (OSTI)

We investigate operating system noise, which we identify as one of the main reasons for a lack of synchronicity in parallel applications. Using a microbenchmark, we measure the noise on several contemporary platforms and find that, even with a general-purpose ... Keywords: Microbenchmark, Noise, Petascale, Synchronicity

Pete Beckman; Kamil Iskra; Kazutomo Yoshii; Susan Coghlan; Aroon Nataraj

2008-03-01T23:59:59.000Z

395

Subcritical measurements using the /sup 252/Cf source-driven neutron noise analysis method  

SciTech Connect

This paper describes recent measurements of the subcritical neutron multiplication factor using the /sup 252/Cf source-driven neutron noise analysis method. This work was supported by a program of collaboration between the United States Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan related to the development of fast breeder technology. The experiment reported consists of a configuration of two interacting tanks of uranyl nitrate aqueous solution with different uranium concentrations in each tank. The /sup 252/Cf-source-driven neutron noise analysis method obtains the subcriticality from the signals of three detectors: the first, a parallel plate ionization chamber with /sup 252/Cf electroplated on one of its plates that is located in or near the system containing the fissile material, and produces an electrical pulse for every spontaneous fission that occurs and thereby serves as a timed source of fission neutrons; and the second and third detectors that are placed in or near the system containing fissile material and serve to detect particles from the fission chain multiplication process. 9 refs.

Mihalczo, J.T.; Blakeman, E.D.; Ragan, G.E.; Kryter, R.C.

1985-01-01T23:59:59.000Z

396

Suppression MHD instabilities by IBW heating in HT-7 Tokamak  

E-Print Network (OSTI)

In HT-7 tokamak, the m= 2/1 tearing mode can be effectively suppressed by the ion bernstein wave (IBW) when the location of power deposition is near the q=2 rational surface. Off-axis electron heating and greatly increase of electron density was observed, in the meantime, the particle confinement appears to be improved with the increased of the central line averaged electron density and the drop of Da emission. Induced large ne gradients and pressures were spatially correlated with the IBW deposition profile by theoretical calculation >. It is suggested that off-axis IBW heating modifies the electron pressure profile, and so the current density profile could be redistributed resulting in the suppression of the magnetohydrodynamics (MHD) instability. It provides an integrated way for making combined effects on both the stabilization of tearing modes and controlling of pressure profile.

C. M. Qin; Y. P. Zhao; X. J. Zhang; P. Xu; Y. Yang; the HT-7 team

2010-01-20T23:59:59.000Z

397

White noise assumptions revisited: regression metamodels and experimental designs in practice  

Science Conference Proceedings (OSTI)

Classic linear regression metamodels and their concomitant experimental designs assume a univariate (not multivariate) simulation response and white noise. By definition, white noise is normally (Gaussian), independently (implying no common random numbers), ...

Jack P. C. Kleijnen

2006-12-01T23:59:59.000Z

398

Utilization of variation optimization for location of emitter of random noise signal  

Science Conference Proceedings (OSTI)

In the paper the information method for optimal location of random noise signal emitter is suggested. The optimization is carried out on energy-information criterion, which makes it possible to locate site of generator of noise signal using geometric ...

H. H. Asadov; N. A. Abdullayev; M. J. Kerimov; E. F. Dadashov

2010-09-01T23:59:59.000Z

399

Distinguishing codes from noise : fundamental limits and applications to sparse communication  

E-Print Network (OSTI)

This thesis investigates the problem of distinguishing codes from noise. We develop a slotted channel model where in each time slot, the channel input is either a codeword or a noise sequence. In this model, successful ...

Wang, Da, S.M. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

400

Brownian force noise from molecular collisions and the sensitivity of advanced gravitational wave observatories  

E-Print Network (OSTI)

We present an analysis of Brownian force noise from residual gas damping of reference test masses as a fundamental sensitivity limit in small force experiments. The resulting acceleration noise increases significantly when ...

Evans, Matthew J.

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Time-domain non-Monte Carlo noise simulation for nonlinear dynamic circuits with arbitrary excitations  

Science Conference Proceedings (OSTI)

A new, time-domain, non-Monte Carlo method for computer simulation of electrical noise in nonlinear dynamic circuits with arbitrary excitations is presented. This time-domain noise simulation ...

Alper Demir; Edward W. Y. Liu; Alberto L. Sangiovanni-Vincentelli

1994-11-01T23:59:59.000Z

402

Noise figure and photon probability distribution in Coherent Anti-Stokes Raman Scattering (CARS)  

E-Print Network (OSTI)

The noise figure and photon probability distribution are calculated for coherent anti-Stokes Raman scattering (CARS) where an anti-Stokes signal is converted to Stokes. We find that the minimum noise figure is ~ 3dB.

Dimitropoulos, D; Jalali, B; Solli, D R

2006-01-01T23:59:59.000Z

403

Analysis of shot noise in the detection of ultrashort optical pulse trains  

E-Print Network (OSTI)

We present a frequency domain model of shot noise in the photodetection of ultrashort optical pulse trains using a time-varying analysis. Shot noise-limited photocurrent power spectral densities, signal-to-noise expressions, and shot noise spectral correlations are derived that explicitly include the finite response of the photodetector. It is shown that the strength of the spectral correlations in the shot noise depends on the optical pulse width, and that these correlations can create orders-of-magnitude imbalance between the shot noise-limited amplitude and phase noise of photonically generated microwave carriers. It is also shown that only by accounting for spectral correlations can shot noise be equated with the fundamental quantum limit in the detection of optical pulse-to-pulse timing jitter.

Franklyn Quinlan; Tara M. Fortier; Haifeng Jiang; Scott A. Diddams

2013-02-25T23:59:59.000Z

404

Evaluating Laplace Noise Addition to Satisfy Differential Privacy for Numeric Data  

Science Conference Proceedings (OSTI)

Laplace noise addition is often advanced as an approach for satisfying differential privacy. There have been several illustrations of the application of Laplace noise addition for count data, but no evaluation of its performance for numeric data. In ...

Rathindra Sarathy; Krishnamurty Muralidhar

2011-04-01T23:59:59.000Z

405

Vector Higgs bosons and possible suppression of flavorchanging neutral current  

E-Print Network (OSTI)

We replace the scalar Higgs doublet with a vector Higgs boson doublet to the unified electroweak W-S model and find most of important features of W-S model are kept unchanged only the Higgs boson now become vector bosons. Lorentz invariance has been carefully discussed. The most important challenge is there will be three massless vector Higgs bosons. The remarkable effect is the possible suppression of the flavorchanging neutral current compare to the multi-Higgs model.

Xiao Yu Qian

2006-10-17T23:59:59.000Z

406

Quantum Suppression of the Rayleigh Instability in Nanowires  

E-Print Network (OSTI)

A linear stability analysis of metallic nanowires is performed in the free-electron model using quantum chaos techniques. It is found that the classical instability of a long wire under surface tension can be completely suppressed by electronic shell effects, leading to stable cylindrical configurations whose electrical conductance is a magic number 1, 3, 5, 6,... times the quantum of conductance. Our results are quantitatively consistent with recent experiments with alkali metal nanowires.

F. Kassubek; C. A. Stafford; Hermann Grabert; Raymond E. Goldstein

2000-06-14T23:59:59.000Z

407

Suppression of heavy impurities in the ST Tokamak  

SciTech Connect

Two different discharges in the ST Tokamak are described: A discharge dominated by high-Z (iron) impurity (Case A), and one dominated by low-Z (oxygen) impurity (Case B). The oxygen-dominated discharge shows higher electron temperature and longer containment time than the iron-dominated discharge. Suppression of Fe and Mo impurities has been achieved by pulsing in air for a few hundred shots. (auth)

Meservey, E.; Bretz, N.; Dimock, D.; Hinnov, E.

1975-12-01T23:59:59.000Z

408

Finding Connections Among Indoor Noise Criteria, Human Perception, and Worker Performance  

Science Conference Proceedings (OSTI)

Clickity?clickity?clickity?CLACKity … clickity?clickity?clickity?CLACKity … what is creating that background noise in your office

Lily M. Wang; Erica E. Bowden

2006-01-01T23:59:59.000Z

409

A 50 year comparison of ambient ocean noise near San Clemente Island: A bathymetrically complex coastal region off Southern California.  

E-Print Network (OSTI)

?1993?. “Wind dependence of deep ocean ambient noise at lowS. M. ?2006?. “Increases in deep ocean ambient noise in theResearch Council ?2003?. Ocean Noise and Marine Mammals ?Na-

McDonald, Mark A; Hildebrand, John A; Wiggins, Sean M; Ross, Donald

2008-01-01T23:59:59.000Z

410

Selection of Thresholding Scheme for Image Noise Reduction on Wavelet Components Using Bayesian Estimation  

Science Conference Proceedings (OSTI)

Methods for image noise reduction based on wavelet analysis perform by first decomposing the image and then by applying non-linear compression functions on the wavelet components. The approach commonly used to reduce the noise is to threshold the absolute ... Keywords: Bayesian estimation, Image noise reduction, wavelet analysis

A. De Stefano; P. R. White; W. B. Collis

2004-11-01T23:59:59.000Z

411

Computing combustion noise by combining Large Eddy Simulations with analytical models for the propagation of waves  

E-Print Network (OSTI)

Computing combustion noise by combining Large Eddy Simulations with analytical models +++++ Presented by Ignacio Duran Abstract Two mechanisms control combustion noise generation as shown by Marble. A method to calculate combustion-generated noise has been implemented in a tool called CHORUS. The method

Paris-Sud XI, Université de

412

Coping with buffer delay change due to power and ground noise  

Science Conference Proceedings (OSTI)

Variation of power and ground levels affect VLSI circuit performance. Trends in device technology and in packaging have necessitated a revision in conventional delay models. In particular, simple scalable models are needed to predict delays in the presence ... Keywords: common mode noise, differential mode noise, incremental delay change, power and ground noise

Lauren Hui Chen; Malgorzata Marek-Sadowska; Forrest Brewer

2002-06-01T23:59:59.000Z

413

Some properties of zero power neutron noise in a time-varying medium with delayed neutrons  

E-Print Network (OSTI)

, there has been a gap between zero power noise and power reactor noise, i.e. in the theory of tem- poral Budapest 114, P.O. Box 49, Hungary c Chalmers University of Technology, Department of Nuclear Engineering of the present authors. Such a treatment gives account of both the so-called zero power reactor noise

Pázsit, Imre

414

Simultaneous shield insertion and net ordering under explicit RLC noise constraint  

Science Conference Proceedings (OSTI)

For multiple coupled RLC nets, we formulate the min-area simultaneous shield insertion and net ordering SINO/NB-&ngr; problem to satisfy the given noise bound. We develop an efficient and conservative model to compute the peak noise, and apply the noise ...

Kevin M. Lepak; Irwan Luwandi; Lei He

2001-06-01T23:59:59.000Z

415

Blogger, stick to your story: modeling topical noise in blogs with coherence measures  

Science Conference Proceedings (OSTI)

Topical noise in blogs arises when bloggers digress from the central topical thrust of their blogs. We introduce a method to explicitly incorporate a model of topical noise into a language modeling approach to the task of blog distillation. Topical noise ... Keywords: blog distillation, coherence measures, language models

Jiyin He; Wouter Weerkamp; Martha Larson; Maarten de Rijke

2008-07-01T23:59:59.000Z

416

Noise-Tolerant Model of a Ternary Inverter Based on Markov Random Field  

Science Conference Proceedings (OSTI)

A noise-tolerant model of a ternary inverter is proposed based on extension of Markov Random Field (MRF). Simulation results are reported to justify the noise immunity of this model using PSPICE and 16-nm Berkeley CMOS technology. Keywords: ternary inverter, noise-tolerance, Markov random field model

Golam Tangim, Svetlana N. Yanushkevich, Seiya Kasai, Vlad P. Shmerko

2013-05-01T23:59:59.000Z

417

Efficient Global Optimization Under Conditions of Noise and  

E-Print Network (OSTI)

Incomplete convergence in numerical simulation such as computational physics simulations and/or Monte Carlo simulations can enter into the calculation of the objective function in an optimization problem, producing noise, bias, and topographical inaccuracy in the objective function. These affect accuracy and convergence rate in the optimization problem. This paper is concerned with global searching of a diverse parameter space, graduating to accelerated local convergence to a (hopefully) global optimum, in a framework that acknowledges convergence uncertainty and manages model resolution to efficiently reduce uncertainty in the final optimum. In its own right, the global-to-local optimization engine employed here (devised for noise tolerance) performs better than other classical and contemporary optimization approaches tried individually and in combination on the "industrial" test problem to be presented.

Uncertainty Multi-Model Multi-Grid; Vicente J. Romero

1999-01-01T23:59:59.000Z

418

Radar antenna pointing for optimized signal to noise ratio.  

Science Conference Proceedings (OSTI)

The Signal-to-Noise Ratio (SNR) of a radar echo signal will vary across a range swath, due to spherical wavefront spreading, atmospheric attenuation, and antenna beam illumination. The antenna beam illumination will depend on antenna pointing. Calculations of geometry are complicated by the curved earth, and atmospheric refraction. This report investigates optimizing antenna pointing to maximize the minimum SNR across the range swath.

Doerry, Armin Walter; Marquette, Brandeis [General Atomics Aeronautical Systems, Inc., San Diego, CA

2013-01-01T23:59:59.000Z

419

Control of Noise in Chemical and Biochemical Information Processing  

E-Print Network (OSTI)

We review models and approaches for error-control in order to prevent the buildup of noise when gates for digital chemical and biomolecular computing based on (bio)chemical reaction processes are utilized to realize stable, scalable networks for information processing. Solvable rate-equation models illustrate several recently developed methodologies for gate-function optimization. We also survey future challenges and possible new research avenues.

Vladimir Privman

2010-10-09T23:59:59.000Z

420

Classical capacity of quantum channels with general Markovian correlated noise  

E-Print Network (OSTI)

The classical capacity of a quantum channel with arbitrary Markovian correlated noise is evaluated. For the general case of a channel with long-term memory, which corresponds to a Markov chain which does not converge to equilibrium, the capacity is expressed in terms of the communicating classes of the Markov chain. For an irreducible and aperiodic Markov chain, the channel is forgetful, and one retrieves the known expression for the capacity.

Nilanjana Datta; Tony Dorlas

2007-12-05T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Systems  

E-Print Network (OSTI)

Abstract Developing usable and robust mixed reality systems requires unique human–computer interaction techniques and customized hardware systems. The design of the hardware is directed by the requirements of the rich 3D interactions that can be performed using immersive mobile MR systems. Geometry modeling and capture, navigational annotations, visualizations, and training simulations are all enhanced using augmented computer graphics. We present the design guidelines that have led us through 10 years of evolving mobile outdoor MR hardware systems.

Benjamin Avery; Ross T. Smith; Wayne Piekarski; Bruce H. Thomas

2009-01-01T23:59:59.000Z

422

2001: An Airspace Odyssey SUMMARY PROCEEDINGS OF THE 2001 AIRPORT NOISE SYMPOSIUM AND AIRPORT AIR QUALITY SYMPOSIUM  

E-Print Network (OSTI)

the use of advanced fan blade design and low noise fan exitreduce compressor fan noise, and the design of the nacelle

Gosling, Geoffrey D.

2001-01-01T23:59:59.000Z

423

Target tracking onboard an autonomous underwater vehicle: determining optimal towed array heading in an anisotropic noise field .  

E-Print Network (OSTI)

??In order to overcome the challenges that an anisotropic noise field poses for underwater target tracking, we conduct an onboard estimation of the horizontal noise… (more)

Parra-Orlandoni, Maria Alejandra.

2007-01-01T23:59:59.000Z

424

Trailing edge noise theory for rotating blades in uniform flow  

E-Print Network (OSTI)

This paper presents a new formulation for trailing edge noise radiation from rotating blades based on an analytical solution of the convective wave equation. It accounts for distributed loading and the effect of mean flow and spanwise wavenumber. A commonly used theory due to Schlinker and Amiet (1981) predicts trailing edge noise radiation from rotating blades. However, different versions of the theory exist; it is not known which version is the correct one and what the range of validity of the theory is. This paper addresses both questions by deriving Schlinker and Amiet's theory in a simple way and by comparing it to the new formulation, using model blade elements representative of a wind turbine, a cooling fan and an aircraft propeller. The correct form of Schlinker and Amiet's theory (1981) is identified. It is valid at high enough frequency, i.e. for a Helmholtz number relative to chord greater than one and a rotational frequency much smaller than the angular frequency of the noise sources.

Sinayoko, Samuel; Agarwal, Anurag

2013-01-01T23:59:59.000Z

425

A simple test for periodic signals in red noise  

E-Print Network (OSTI)

We demonstrate a simple method for testing the significance of peaks in the periodogram of red noise data. The procedure was designed to test for spurious periodicities in X-ray light curves of active galaxies, but can be used quite generally to test for periodic components against a background noise spectrum assumed to have a power law shape. The method provides a simple and fast test of the significance of candidate periodic signals in short, well-sampled time series such as those obtained from XMM-Newton observations of Seyfert galaxies, without the need for Monte Carlo simulations. A full account is made of the number of trials and the uncertainties inherent to the model fitting. Ignoring these subtle effects can lead to substantially overestimated significances. These difficulties motivate us to demand high standards of detection (minimum >99.9 per cent confidence) for periodicities in sources that normally show red noise spectra. The method also provides a simple means to estimate the power spectral index, which may be an interesting parameter itself, regardless of the presence/absence of periodicities.

S. Vaughan

2004-12-30T23:59:59.000Z

426

Johnson Noise Thermometry for Advanced Small Modular Reactors  

Science Conference Proceedings (OSTI)

Temperature is a key process variable at any nuclear power plant (NPP). The harsh reactor environment causes all sensor properties to drift over time. At the higher temperatures of advanced NPPs the drift occurs more rapidly. The allowable reactor operating temperature must be reduced by the amount of the potential measurement error to assure adequate margin to material damage. Johnson noise is a fundamental expression of temperature and as such is immune to drift in a sensor’s physical condition. In and near the core, only Johnson noise thermometry (JNT) and radiation pyrometry offer the possibility for long-term, high-accuracy temperature measurement due to their fundamental natures. Small Modular Reactors (SMRs) place a higher value on long-term stability in their temperature measurements in that they produce less power per reactor core and thus cannot afford as much instrument recalibration labor as their larger brethren. The purpose of the current ORNL-led project, conducted under the Instrumentation, Controls, and Human-Machine Interface (ICHMI) research pathway of the U.S. Department of Energy (DOE) Advanced SMR Research and Development (R&D) program, is to develop and demonstrate a drift free Johnson noise-based thermometer suitable for deployment near core in advanced SMR plants.

Britton, C.L.,Jr.; Roberts, M.; Bull, N.D.; Holcomb, D.E.; Wood, R.T.

2012-09-15T23:59:59.000Z

427

Johnson Noise Thermometry for Advanced Small Modular Reactors  

SciTech Connect

Temperature is a key process variable at any nuclear power plant (NPP). The harsh reactor environment causes all sensor properties to drift over time. At the higher temperatures of advanced NPPs the drift occurs more rapidly. The allowable reactor operating temperature must be reduced by the amount of the potential measurement error to assure adequate margin to material damage. Johnson noise is a fundamental expression of temperature and as such is immune to drift in a sensor s physical condition. In and near core, only Johnson noise thermometry (JNT) and radiation pyrometry offer the possibility for long-term, high-accuracy temperature measurement due to their fundamental natures. Small, Modular Reactors (SMRs) place a higher value on long-term stability in their temperature measurements in that they produce less power per reactor core and thus cannot afford as much instrument recalibration labor as their larger brethren. The purpose of this project is to develop and demonstrate a drift free Johnson noise-based thermometer suitable for deployment near core in advanced SMR plants.

Britton Jr, Charles L [ORNL; Roberts, Michael [ORNL; Bull, Nora D [ORNL; Holcomb, David Eugene [ORNL; Wood, Richard Thomas [ORNL

2012-10-01T23:59:59.000Z

428

Resolution and noise trade-off analysis for volumetric CT  

Science Conference Proceedings (OSTI)

Until recently, most studies addressing the trade-off between spatial resolution and quantum noise were performed in the context of single-slice CT. In this study, we extend the theoretical framework of previous works to volumetric CT and further extend it by taking into account the actual shapes of the preferred reconstruction kernels. In the experimental study, we also attempt to explore a three-dimensional approach for spatial resolution measurement, as opposed to the conventional two-dimensional approaches that were widely adopted in previously published studies. By scanning a finite-sized sphere phantom, the MTF was measured from the edge profile along the spherical surface. Cases of different resolutions (and noise levels) were generated by adjusting the reconstruction kernel. To reduce bias, the total photon fluxes were matched: 120 kVp, 200 mA, and 1 s per gantry rotation. All data sets were reconstructed using a modified FDK algorithm under the same condition: Scan field-of-view (SFOV)=10 cm, and slice thickness=0.625 mm. The theoretical analysis indicated that the variance of noise is proportional to >4th power of the spatial resolution. Our experimental results supported this conclusion by showing the relationship is 4.6th (helical) or 5th (axial) power.

Li Baojun; Avinash, Gopal B.; Hsieh, Jiang [Applied Science Laboratory, General Electric Healthcare, Waukesha, Wisconsin 53188 (United States)

2007-10-15T23:59:59.000Z

429

Quantitative comparison of noise texture across CT scanners from different manufacturers  

SciTech Connect

Purpose: To quantitatively compare noise texture across computed tomography (CT) scanners from different manufacturers using the noise power spectrum (NPS). Methods: The American College of Radiology CT accreditation phantom (Gammex 464, Gammex, Inc., Middleton, WI) was imaged on two scanners: Discovery CT 750HD (GE Healthcare, Waukesha, WI), and SOMATOM Definition Flash (Siemens Healthcare, Germany), using a consistent acquisition protocol (120 kVp, 0.625/0.6 mm slice thickness, 250 mAs, and 22 cm field of view). Images were reconstructed using filtered backprojection and a wide selection of reconstruction kernels. For each image set, the 2D NPS were estimated from the uniform section of the phantom. The 2D spectra were normalized by their integral value, radially averaged, and filtered by the human visual response function. A systematic kernel-by-kernel comparison across manufacturers was performed by computing the root mean square difference (RMSD) and the peak frequency difference (PFD) between the NPS from different kernels. GE and Siemens kernels were compared and kernel pairs that minimized the RMSD and |PFD| were identified. Results: The RMSD (|PFD|) values between the NPS of GE and Siemens kernels varied from 0.01 mm{sup 2} (0.002 mm{sup -1}) to 0.29 mm{sup 2} (0.74 mm{sup -1}). The GE kernels 'Soft,''Standard,''Chest,' and 'Lung' closely matched the Siemens kernels 'B35f,''B43f,''B41f,' and 'B80f' (RMSD < 0.05 mm{sup 2}, |PFD| < 0.02 mm{sup -1}, respectively). The GE 'Bone,''Bone+,' and 'Edge' kernels all matched most closely with Siemens 'B75f' kernel but with sizeable RMSD and |PFD| values up to 0.18 mm{sup 2} and 0.41 mm{sup -1}, respectively. These sizeable RMSD and |PFD| values corresponded to visually perceivable differences in the noise texture of the images. Conclusions: It is possible to use the NPS to quantitatively compare noise texture across CT systems. The degree to which similar texture across scanners could be achieved varies and is limited by the kernels available on each scanner.

Solomon, Justin B.; Christianson, Olav; Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Department of Radiology, Medical Physics Graduate Program, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27705 (United States); Carl E. Ravin Advanced Imaging Laboratories and Clinical Imaging Physics Group, Medical Physics Graduate Program, Departments of Radiology, Physics, Biomedical Engineering, and Electrical and Computer Engineering, Duke University, Durham, North Carolina 27705 (United States)

2012-10-15T23:59:59.000Z

430

Vacuum squeezing via polarization self-rotation and excess noise in hot Rb vapors  

E-Print Network (OSTI)

We present experimental and theoretical analysis of quantum fluctuation in a vacuum field in the presence of orthogonal linearly polarized pump field propagating through a Rb vapor cell. Previously reported theoretical and experimental studies provided somewhat contradictory conclusions regarding the possibility to observe the "squeezed vacuum" -- the reduction of vacuum fluctuations below standard quantum limit -- in this system. Here, using the D1 transitions of Rb in a cell without buffer as as an example, we demonstrate that vacuum squeezing is corrupted by incoherent processes (such as spontaneous emission, elastic scattering, etc.), and its observation is only possible in a specific small region of the experimental parameter space. Numerical simulations, in good agreement with the experiment, demonstrate that the two excited state hyperfine levels play a crucial role in the squeezing and excess noise production. The significant influence of far-detuned atoms on the field fluctuations at low noise frequencies imposes the explicit consideration of the full velocity distribution of the atomic vapor.

Eugeniy E. Mikhailov; Arturo Lezama; Thomas W. Noel; Irina Novikova

2009-03-18T23:59:59.000Z

431

February 2013 Most Viewed Documents for Biology And Medicine...  

Office of Scientific and Technical Information (OSTI)

therapy NONE (1997) 79 Advisory Committee on human radiation experiments final report NONE (1995) 77 SURVEY OF NOISE SUPPRESSION SYSTEMS FOR ENGINE GENERATOR SETS....

432

Simulation of Thermal Stratification in BWR Suppression Pools with One Dimensional Modeling Method  

Science Conference Proceedings (OSTI)

The suppression pool in a boiling water reactor (BWR) plant not only is the major heat sink within the containment system, but also provides the major emergency cooling water for the reactor core. In several accident scenarios, such as a loss-of-coolant accident and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; the pool temperature distribution also affects the NPSHa (available net positive suction head) and therefore the performance of the Emergency Core Cooling System and Reactor Core Isolation Cooling System pumps that draw cooling water back to the core. Current safety analysis codes use zero dimensional (0-D) lumped parameter models to calculate the energy and mass balance in the pool; therefore, they have large uncertainties in the prediction of scenarios in which stratification and mixing are important. While three-dimensional (3-D) computational fluid dynamics (CFD) methods can be used to analyze realistic 3-D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, resulting in a long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code (Berkeley mechanistic MIXing code in C++) has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by one-dimensional (1-D) transient partial differential equations and substructures (such as free or wall jets) are modeled with 1-D integral models. This allows very large reductions in computational effort compared to multi-dimensional CFD modeling. One heat-up experiment performed at the Finland POOLEX facility, which was designed to study phenomena relevant to Nordic design BWR suppression pool including thermal stratification and mixing, is used for validation. Comparisons between the BMIX++, GOTHIC, and CFD calculations against the POOLEX experimental data are discussed in detail.

Haihua Zhao; Ling Zou; Hongbin Zhang

2014-01-01T23:59:59.000Z

433

Effects of Vacuum Fluctuation Suppression on Atomic Decay Rates  

E-Print Network (OSTI)

The use of atomic decay rates as a probe of sub-vacuum phenomena will be studied. Because electromagnetic vacuum fluctuations are essential for radiative decay of excited atomic states, decay rates can serve as a measure of the suppression of vacuum fluctuation in non-classical states, such as squeezed vacuum states. In such states the renormalized expectation value of the square of the electric field or the energy density can be periodically negative, representing suppression of vacuum fluctuations. We explore the extent to which atomic decays can be used to measure the mean squared electric field or energy density. We consider a scheme in which atoms in an excited state transit a closed cavity whose lowest mode contains photons in a non-classical state. The change in the decay probability of the atom in the cavity due to the non-classical state can, under certain circumstances, serve as a measure of the mean squared electric field or energy density in the cavity. We derive a quantum inequality bound on the ...

Ford, L H

2009-01-01T23:59:59.000Z

434

Effects of Vacuum Fluctuation Suppression on Atomic Decay Rates  

E-Print Network (OSTI)

The use of atomic decay rates as a probe of sub-vacuum phenomena will be studied. Because electromagnetic vacuum fluctuations are essential for radiative decay of excited atomic states, decay rates can serve as a measure of the suppression of vacuum fluctuation in non-classical states, such as squeezed vacuum states. In such states the renormalized expectation value of the square of the electric field or the energy density can be periodically negative, representing suppression of vacuum fluctuations. We explore the extent to which atomic decays can be used to measure the mean squared electric field or energy density. We consider a scheme in which atoms in an excited state transit a closed cavity whose lowest mode contains photons in a non-classical state. The change in the decay probability of the atom in the cavity due to the non-classical state can, under certain circumstances, serve as a measure of the mean squared electric field or energy density in the cavity. We derive a quantum inequality bound on the decrease in this probability. We also show that the decrease in decay rate can sometimes be a measure of negative energy density or negative squared electric field. We make some estimates of the magnitude of this effect, which indicate that an experimental test might be possible.

L. H. Ford; Thomas A. Roman

2009-07-09T23:59:59.000Z

435

Spatial filter performance on point-target detection in various clutter conditions using visible images  

E-Print Network (OSTI)

For a search-and-track system, detection of point targets in clutter is a challenge because spatial noise in an image can be much greater than temporal noise. Suppression of clutter uses a spatial filter matched to the ...

Hwang, Susan, M. Eng. Massachusetts Institute of Technology

2007-01-01T23:59:59.000Z

436

Aging in coherent noise models and natural time  

Science Conference Proceedings (OSTI)

Event correlation between aftershocks in the coherent noise model is studied by making use of natural time, which has recently been introduced in complex time-series analysis. It is found that the aging phenomenon and the associated scaling property discovered in the observed seismic data are well reproduced by the model. It is also found that the scaling function is given by the q-exponential function appearing in nonextensive statistical mechanics, showing power-law decay of event correlation in natural time.

Tirnakli, Ugur; Abe, Sumiyoshi [Department of Physics, Faculty of Science, Ege University, 35100 Izmir (Turkey); Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan)

2004-11-01T23:59:59.000Z

437

Transient plasma estimation: a noise cancelling/identification approach  

DOE Green Energy (OSTI)

The application of a noise cancelling technique to extract energy storage information from sensors occurring during fusion reactor experiments on the Tandem Mirror Experiment-Upgrade (TMX-U) at the Lawrence Livermore National Laboratory (LLNL) is examined. We show how this technique can be used to decrease the uncertainty in the corresponding sensor measurements used for diagnostics in both real-time and post-experimental environments. We analyze the performance of algorithm on the sensor data and discuss the various tradeoffs. The algorithm suggested is designed using SIG, an interactive signal processing package developed at LLNL.

Candy, J.V.; Casper, T.; Kane, R.

1985-03-01T23:59:59.000Z

438

Electronic noise-free measurements of squeezed light  

E-Print Network (OSTI)

We study the implementation of a correlation measurement technique for the characterization of squeezed light. We show that the sign of the covariance coefficient revealed from the time resolved correlation data allow us to distinguish between squeezed, coherent and thermal states. In contrast to the traditional method of characterizing squeezed light, involving measurement of the variation of the difference photocurrent, the correlation measurement method allows to eliminate the contribution of the electronic noise, which becomes a crucial issue in experiments with dim sources of squeezed light.

Leonid A. Krivitsky; Ulrik L. Andersen; Ruifang Dong; Alexander Huck; Christoffer Wittmann; Gerd Leuchs

2008-07-09T23:59:59.000Z

439

Characterizing the effects of clock jitter due to substrate noise in discrete-time D/S modulators  

Science Conference Proceedings (OSTI)

This paper investigates the impact of clock jitter induced by substrate noise on the performance of the oversampling DS modulators. First, a new stochastic model for substrate noise is proposed. This model is then utilized to study the clock jitter in ... Keywords: DS modulators, jitter, mixed-signal integrated circuits, phase noise, phase-locked loop, substrate noise

Payam Heydari

2003-06-01T23:59:59.000Z

440

Conductance fluctuations in chaotic systems with tunnel barriers  

E-Print Network (OSTI)

Quantum effects are expected to disappear in the short-wavelength, semiclassical limit. As a matter of fact, recent investigations of transport through quantum chaotic systems have demonstrated the exponential suppression of the weak localization corrections to the conductance and of the Fano factor for shot-noise when the Ehrenfest time exceeds the electronic dwell time. On the other hand, conductance fluctuations, an effect of quantum coherence, retain their universal value in the limit of the ratio of Ehrenfest time over dwell time to infinity, when the system is ideally coupled to external leads. Motivated by this intriguing result we investigate conductance fluctuations through quantum chaotic cavities coupled to external leads via (tunnel) barriers of arbitrary transparency. Using the trajectory-based semiclassical theory of transport, we find a linear Ehrenfest time-dependence of the conductance variance showing a nonmonotonous, sinusoidal behavior as a function of the transperancy. Most notably, we find an increase of the conductance fluctuations with the Ehrenfest time, above their universal value, for the transparency less than 0.5. These results, confirmed by numerical simulations, show that, contrarily to the common wisdom, effects of quantum coherence may increase in the semiclassical limit, under special circumstances.

Daniel Waltner; Jack Kuipers; Philippe Jacquod; Klaus Richter

2011-08-25T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Dynamics of stainless steel turning: Analysis by flicker-noise spectroscopy  

E-Print Network (OSTI)

We use flicker-noise spectroscopy (FNS), a phenomenological method for the analysis of time and spatial series operating on structure functions and power spectrum estimates, to identify and study harmful chatter vibrations in a regenerative turning process. The 3D cutting force components experimentally measured during stainless steel turning are analyzed, and the parameters of their stochastic dynamics are estimated. Our analysis shows that the system initially exhibiting regular vibrations associated with spindle rotation becomes unstable to high-frequency noisy oscillations (chatter) at larger cutting depths. We suggest that the chatter may be attributed to frictional stick-and-slip interactions between the contact surfaces of cutting tool and workpiece. We compare our findings with previously reported results obtained by statistical, recurrence, multifractal, and wavelet methods. We discuss the potential of FNS in monitoring the turning process in manufacturing practice.

Litak, Grzegorz; Timashev, Serge F; Rusinek, Rafal

2013-01-01T23:59:59.000Z

442

Dynamics of stainless steel turning: Analysis by flicker-noise spectroscopy  

E-Print Network (OSTI)

We use flicker-noise spectroscopy (FNS), a phenomenological method for the analysis of time and spatial series operating on structure functions and power spectrum estimates, to identify and study harmful chatter vibrations in a regenerative turning process. The 3D cutting force components experimentally measured during stainless steel turning are analyzed, and the parameters of their stochastic dynamics are estimated. Our analysis shows that the system initially exhibiting regular vibrations associated with spindle rotation becomes unstable to high-frequency noisy oscillations (chatter) at larger cutting depths. We suggest that the chatter may be attributed to frictional stick-and-slip interactions between the contact surfaces of cutting tool and workpiece. We compare our findings with previously reported results obtained by statistical, recurrence, multifractal, and wavelet methods. We discuss the potential of FNS in monitoring the turning process in manufacturing practice.

Grzegorz Litak; Yuriy S. Polyakov; Serge F. Timashev; Rafal Rusinek

2013-07-31T23:59:59.000Z

443

Quasi-Periodicity in global solar radio flux at metric wavelengths during Noise Storms  

E-Print Network (OSTI)

We present observational results from studying the quasi-periodicities in global solar radio flux during periods of enhanced noise storm activity, over durations of ~4 hrs a day ("intra-day" variations), observed at 77.5 MHz with the newly commissioned log-periodic array tracking system at the Gauribidanur radio observatory. Positional information on the storm centers were obtained with the radio imaging data from the Nancay (sic.) Radioheliograph (NRH), while their active region (AR) counterparts on the photosphere (and the overlying chromosphere) were located from the H-alpha images of the Big Bear Solar Observatory (BBSO). The quasi-periodicity in flux was found to be 110 minutes, with the fluctuation in flux being 3(+/- 1.5) solar flux units (sfu). The results of such pulsations are interpreted qualitatively as evidence for coronal seismology.

G. A. Shanmugha Sundaram; K. R. Subramanian

2004-04-13T23:59:59.000Z

444

Quasi-Periodicity in global solar radio flux at metric wavelengths during Noise Storms  

E-Print Network (OSTI)

We present observational results from studying the quasi-periodicities in global solar radio flux during periods of enhanced noise storm activity, over durations of ~4 hrs a day ("intra-day" variations), observed at 77.5 MHz with the newly commissioned log-periodic array tracking system at the Gauribidanur radio observatory. Positional information on the storm centers were obtained with the radio imaging data from the Nancay (sic.) Radioheliograph (NRH), while their active region (AR) counterparts on the photosphere (and the overlying chromosphere) were located from the H-alpha images of the Big Bear Solar Observatory (BBSO). The quasi-periodicity in flux was found to be 110 minutes, with the fluctuation in flux being 3(+/- 1.5) solar flux units (sfu). The results of such pulsations are interpreted qualitatively as evidence for coronal seismology.

Subramanian, K R

2004-01-01T23:59:59.000Z

445

Quasi-Periodicity in global solar radio flux at metric wavelengths during Noise Storms.  

E-Print Network (OSTI)

Abstract. We present observational results from studying the quasi-periodicities in global solar radio flux during periods of enhanced noise storm activity, over durations of ? 4 hrs a day ( ”intra-day ” variations), observed at 77.5 MHz with the newly commissioned log-periodic array tracking system at the Gauribidanur radio observatory. Positional information on the storm centers were obtained with the radio imaging data from the Nançay RadioHeliograph ( NRH), while their active region ( AR) counterparts on the photosphere ( and the overlying chromosphere) were located from the H? images of the Big Bear Solar Observatory ( BBSO). The quasi-periodicity in flux was found to be 110 minutes, with the fluctuation in flux being 3(±1.5) solar flux units ( sfu). The results of such pulsations are interpreted qualitatively as evidence for coronal seismology.

unknown authors

2004-01-01T23:59:59.000Z

446

A microkelvin cryogen-free experimental platform with integrated noise thermometry  

E-Print Network (OSTI)

We report experimental demonstration of the feasibility of reaching temperatures below 1 mK using cryogen-free technology. Our prototype system comprises an adiabatic nuclear demagnetisation stage, based on hyperfine-enhanced nuclear magnetic cooling, integrated with a commercial cryogen-free dilution refrigerator and 8 T superconducting magnet. Thermometry was provided by a current-sensing noise thermometer. The minimum temperature achieved at the experimental platform was 600 {\\mu}K. The platform remained below 1 mK for over 24 hours, indicating a total residual heat-leak into the experimental stage of 5 nW. We discuss straightforward improvements to the design of the current prototype that are expected to lead to enhanced performance. This opens the way to widening the accessibility of temperatures in the microkelvin regime, of potential importance in the application of strongly correlated electron states in nanodevices to quantum computing.

Batey, Graham; Cuthbert, Michael; Matthews, Anthony; Saunders, John; Shibahara, Aya

2013-01-01T23:59:59.000Z

447

Timing Noise Properties of GRO J0422+32  

E-Print Network (OSTI)

OSSE observed the transient black hole candidate GRO J0422+32 (XN Per 92) between 1992 Aug 11 and 1992 Sep 17. High time resolution data were obtained in several energy bands over the 35-600 keV range with a sampling rate of 8 ms. Power spectra at energies below 175 keV show substantial low-frequency red noise with a shoulder at a few tens of mHz, peaked noise with characteristic frequency near 0.2 Hz, and a second shoulder at a few Hz. The frequencies of the shoulders and the peak are independent of energy and source intensity. The complex cross spectrum indicates that photons in the 75-175 keV band lag photons in the 35-60 keV band by a time roughly proportional to the inverse of the Fourier frequency. The maximum lag observed is about 300 ms. The power and lag spectra are consistent with the production of the gamma rays through thermal Comptonization in an extended hot corona with a power-law density profile.

J. E. Grove; M. S. Strickman; S. M. Matz; X. -M. Hua; D. Kazanas; L. Titarchuk

1998-05-19T23:59:59.000Z

448

Survey of techniques for reduction of wind turbine blade trailing edge noise.  

DOE Green Energy (OSTI)

Aerodynamic noise from wind turbine rotors leads to constraints in both rotor design and turbine siting. The primary source of aerodynamic noise on wind turbine rotors is the interaction of turbulent boundary layers on the blades with the blade trailing edges. This report surveys concepts that have been proposed for trailing edge noise reduction, with emphasis on concepts that have been tested at either sub-scale or full-scale. These concepts include trailing edge serrations, low-noise airfoil designs, trailing edge brushes, and porous trailing edges. The demonstrated noise reductions of these concepts are cited, along with their impacts on aerodynamic performance. An assessment is made of future research opportunities in trailing edge noise reduction for wind turbine rotors.

Barone, Matthew Franklin

2011-08-01T23:59:59.000Z

449

Hammerstein Models for Identification of Stochastic Systems  

Science Conference Proceedings (OSTI)

Identification of nonlinear stochastic systems in the class of Hammerstein models is investigated with regard for the nonlinearities of the investigated object. Hammerstein models are constructed with regard for the output noise in the form of a martingale ...

G. R. Bolkvadze

2003-01-01T23:59:59.000Z

450

Ultra-Long-Haul WDM transmission systems  

Science Conference Proceedings (OSTI)

This paper discusses the key transmission issues and design considerations for ultra-long-haul WDM systems. The key enabling technologies for the current generation of ultra-long-haul WDM transmission are described. Noise analysis and transmission modelling ...

Y. R. Zhou; A. Lord; S. R. Sikora

2002-10-01T23:59:59.000Z

451

Parameter selection for suppressed fuzzy c-means with an application to MRI segmentation  

Science Conference Proceedings (OSTI)

This paper presents an algorithm, called the modified suppressed fuzzy c-means (MS-FCM), that simultaneously performs clustering and parameter selection for the suppressed fuzzy c-means (S-FCM) algorithm proposed by [Fan, J.L., Zhen, W.Z., Xie, W.X., ... Keywords: Fuzzy c-means, Fuzzy clustering, Magnetic resonance image segmentation, Parameter selection, Suppressed fuzzy c-means

Wen-Liang Hung; Miin-Shen Yang; De-Hua Chen

2006-04-01T23:59:59.000Z

452

Electric field suppression of ultracold confined chemical rates  

E-Print Network (OSTI)

We consider ultracold collisions of polar molecules confined in a one dimensional optical lattice. Using a quantum scattering formalism and a frame transformation method, we calculate elastic and chemical quenching rate constants for fermionic molecules. Taking KRb molecules as a prototype, we find that the rate of quenching collisions is enhanced at zero electric field as the confinement is increased, but that this rate is suppressed when the electric field is turned on. For molecules with 500 nK of collision energy, for realistic molecular densities, and for achievable experimental electric fields and trap confinements, we predict lifetimes of KRb molecules of 1 s. We find a ratio of elastic to quenching collision rates of about 100, which may be sufficient to achieve efficient experimental evaporative cooling of polar KRb molecules.

Quéméner, Goulven

2010-01-01T23:59:59.000Z

453

Novel technique of suppressing TBBU in high-energy ERLs  

Science Conference Proceedings (OSTI)

Energy recovery linacs (ERLs) are an emerging generation of accelerators that promise to revolutionize the fields of high-energy physics and photon sciences. These accelerators combine the advantages of linear accelerators with that of storage rings, and augur the delivery of electron beams of unprecedented power and quality. However, one potential weakness of these devices is transverse beam break-up instability that could severely limit the available beam current. In this paper, I propose a novel method of suppressing these dangerous effects using the chromaticity of the transverse motion. In this short paper I am able only to touch the surface of the method and a complete description of the method with all relevant derivations can be found in [1].

Litvinenko V.

2012-05-20T23:59:59.000Z

454

SRAM leakage suppression by minimizing standby supply voltage  

E-Print Network (OSTI)

Suppressing the leakage current in memories is critical in low-power design. By reducing the standby supply voltage (VDD) to its limit, which is the Data Retention Voltage (DRV), leakage power can be substantially reduced. This paper explores how low DRV can be in a standard low leakage SRAM module and analyzes how DRV is affected by parameters such as process variations, chip temperature, and transistor sizing. An analytical model for DRV as a function of process and design parameters is presented, and forms the base for further design space explorations. This model is verified using simulations as well as measurements from a 4KB SRAM chip in a 0.13?m technology. It is demonstrated that an SRAM cell state can be preserved at sub-300mV standby V DD, with more than 90 % leakage power savings. 1.

Huifang Qin; Yu Cao; Dejan Markovic; Andrei Vladimirescu; Jan Rabaey

2004-01-01T23:59:59.000Z

455

Enhancement and suppression of heat transfer by MHD turbulence  

E-Print Network (OSTI)

We study of the effect of turbulence on heat transfer within magnetized plasmas for energy injection velocities both larger and smaller that the Alfven speed. We find that in the latter regime the heat transfer is partially suppressed, while in the former regime the effects of turbulence depend on the intensity of driving. In fact, the scale l at which the turbulent velocity is equal the Alfven velocity is a new important parameter. When the electron mean free path is larger than l, the stronger the the turbulence, the lower thermal conductivity by electrons is. The turbulent motions, however, induces their own advective heat transport, which, for the parameters of intracluster medium (ICM) provides effective heat diffusivity that exceeds the classical Spitzer value.

A. Lazarian

2006-08-02T23:59:59.000Z

456

Mirror thermal noise in laser interferometer gravitational wave detectors operating at room and cryogenic temperature  

E-Print Network (OSTI)

Mirror thermal noise is and will remain one of the main limitations to the sensitivity of gravitational wave detectors based on laser interferometers. We report about projected mirror thermal noise due to losses in the mirror coatings and substrates. The evaluation includes all kind of thermal noises presently known. Several of the envisaged substrate and coating materials are considered. The results for mirrors operated at room temperature and at cryogenic temperature are reported.

Janyce Franc; Nazario Morgado; Raffaele Flaminio; Ronny Nawrodt; Iain Martin; Liam Cunningham; Alan Cumming; Sheila Rowan; James Hough

2009-12-01T23:59:59.000Z

457

A Quiet Phase: NIST Optical Tools Produce Ultra-low-noise ...  

Science Conference Proceedings (OSTI)

... Described in Nature Photonics,* NIST's low-noise apparatus is a new application of optical frequency combs, tools based on ultrafast lasers for ...

2011-07-06T23:59:59.000Z

458

SIMULATION AND EXPERIMENTAL VALIDATION OF AIRBORNE AND STRUCTURE-BORNE NOISE TRANSMISSION IN HVAC PLENUMS.  

E-Print Network (OSTI)

??This research demonstrates the usage of numerical acoustics to model sound and vibrational energy propagation in HVAC ducts and plenums. Noise and vibration in HVAC… (more)

Ramalingam, Srinivasan

2012-01-01T23:59:59.000Z

459

Geothermal: Sponsored by OSTI -- Noise-control needs in the developing...  

Office of Scientific and Technical Information (OSTI)

Noise-control needs in the developing energy technologies Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us | Admin Log On HomeBasic Search About...

460

Imaging and Spectral Studies of Solar type I Noise Storms at Metric Wavelengths.  

E-Print Network (OSTI)

??Type I noise storms constitute a sizeable fraction of the active-Sun component of solar radiation at meter wavelengths. The storms occur over a prolonged duration… (more)

Shanmugha Sundaram, G A

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "noise suppression systems" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Solar Power as a Source of Noise-free Power for Research  

E-Print Network (OSTI)

Solar Power as a Source of Noise-free Power for ResearchState University Keywords: solar energy, reducing backgroundhas been increasing interest in solar convertors, mostly for

Dutta, Akshita; Chorescu, Irinel

2011-01-01T23:59:59.000Z

462

DISCRETE-FREQUENCY AND BROADBAND NOISE RADIATION FROM DIESEL ENGINE COOLING FANS.  

E-Print Network (OSTI)

??This effort focuses on measuring and predicting the discrete-frequency and broadband noise radiated by diesel engine cooling fans. Unsteady forces developed by the interaction of… (more)

Kim, Geon-Seok

2007-01-01T23:59:59.000Z

463

Impacts of Vessel Noise Perturbations on the Resident Sperm Whale Population in the Gulf of Mexico  

E-Print Network (OSTI)

The Gulf of Mexico is home to two of the world?s ten busiest ports by cargo volume, the Port of New Orleans and the Port of Houston; and in 2008, these ports hosted a combined 14,000 ships, a number which is likely only to increase. Past research shows that this increase in shipping worldwide has historically lead to an increase in ambient noise level of 3-5dB per decade. Sperm whales in the Gulf of Mexico are considered a genetically distinct, resident population. They have a preference for the Louisiana-Mississippi Shelf region which directly overlaps with the entrance to the Mississippi and the Port of New Orleans. Disruptions from vessel noise could influence feeding and breeding patterns essential to the health of the stock. Data used in this analysis were collected continuously over 36 days in the summer of 2001 from bottom moored Navy Environmental Acoustic Recording System (EARS) buoys. Results showed a significant difference (P<0.05) in noise level between hours with ships passing and hours without. Metrics for 56 ship passages were analyzed to compare duration of ship passage with duration of maximum received level (MRL) during ship passage. Results of that analysis showed an average ship passage of 29 minutes with average MRL lasting 23% of the ship passage and an average increase of 40dB. Lastly, click counts were made with the Pamguard. Click counts for ship passages were completed for 35 min and 17.5 min before and after the estimated closest point of approach (CPA) for each ship. Results showed a 36% decrease in the number of detectable clicks as a ship approaches when comparing clicks detected at intervals of both 35 minutes before and 17 minutes before the CPA; additionally, 22% fewer clicks were counted 30 min after the ship than 30 min before (results significant at the P=0.01 level). These results indicate a potential change in sperm whale behavior when exposed to large class size vessel traffic (e.g. tankers and container ships) from major shipping lanes. Recommendations for addressing this issue are discussed.

Azzara, Alyson

2012-05-01T23:59:59.000Z

464

An efficient modeling method for thermal stratification simulation in a BWR suppression pool  

SciTech Connect

The suppression pool in a BWR plant not only is the major heat sink within the containment system, but also provides major emergency cooling water for the reactor core. In several accident scenarios, such as LOCA and extended station blackout, thermal stratification tends to form in the pool after the initial rapid venting stage. Accurately predicting the pool stratification phenomenon is important because it affects the peak containment pressure; and the pool temperature distribution also affects the NPSHa (Available Net Positive Suction Head) and therefore the performance of the pump which draws cooling water back to the core. Current safety analysis codes use 0-D lumped parameter methods to calculate the energy and mass balance in the pool and therefore have large uncertainty in prediction of scenarios in which stratification and mixing are important. While 3-D CFD methods can be used to analyze realistic 3D configurations, these methods normally require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, therefore long simulation time. For mixing in stably stratified large enclosures, the BMIX++ code has been developed to implement a highly efficient analysis method for stratification where the ambient fluid volume is represented by 1-D transient partial differential equations and substructures such as free or wall jets are modeled with 1-D integral models. This allows very large reductions in computational effort compared to 3-D CFD modeling. The POOLEX experiments at Finland, which was designed to study phenomena relevant to Nordic design BWR suppression pool including thermal stratification and mixing, are used for validation. GOTHIC lumped parameter models are used to obtain boundary conditions for BMIX++ code and CFD simulations. Comparison between the BMIX++, GOTHIC, and CFD calculations against the POOLEX experimental data is discussed in detail.

Haihua Zhao; Ling Zou; Hongbin Zhang; Hua Li; Walter Villanueva; Pavel Kudinov

2012-09-01T23:59:59.000Z

465

NEW TOOLS FOR CELL SUPPRESSION IN TAU-ARGUS: ONE PIECE OF THE CASC PROJECT WORK DRAFT  

E-Print Network (OSTI)

In the course of the EU funded project CASC, the software t-ARGUS shall be extended to become a generally applicable standard tool for tabular data protection. The required modifications will affect the facilities provided for (residual) disclosure risk statement, the data structure and the user interface. Methods will have to be implemented for protection of complex hierarchical tables and for table-to-table protection, especially in the context of public use data-base query systems. Extensions will be made concerning secondary cell suppression methodology provided by the package. The package will interface in particular with the GHQUAR hypercube algorithm. Finally, table perturbation tools will be added.

Submitted By The; The Yugoslav; Republic Macedonia; English Only; Invited Paper

2001-01-01T23:59:59.000Z

466

Low-noise photodiode detector for optical fluctuation diagnostics  

SciTech Connect

The beam emission spectroscopy optical fluctuation diagnostic requires the highest possible quantum efficiency detector at 656 nm to minimize the photon statistical baseline limit to the detectable fluctuation level. A photoconductive photodiode detector with an extremely low-noise preamplifier and a reactive feedback circuit provides quantum efficiencies up to 70%--80% for a useful frequency range of at least 0--150 kHz with incident powers of {similar to}10 nW. The diodes are chosen for negligible leakage current and hence do not require active cooling. These detectors have provided increase in the sensitivity to plasma fluctuation amplitude by a factor of {similar to}14 over photomultipliers and a factor of 4 over large area avalanche photodiodes.

Fonck, R.J.; Ashley, R.; Durst, R. (Department of Nuclear Engineering and Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)); Paul, S.F.; Renda, G. (Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States))

1992-10-01T23:59:59.000Z

467

Highly efficient energy excitation transfer in light-harvesting complexes: The fundamental role of noise-assisted transport  

E-Print Network (OSTI)

Excitation transfer through interacting systems plays an important role in many areas of physics, chemistry, and biology. The uncontrollable interaction of the transmission network with a noisy environment is usually assumed to deteriorate its transport capacity, especially so when the system is fundamentally quantum mechanical. Here we identify key mechanisms through which noise such as dephasing, perhaps counter intuitively, may actually aid transport through a dissipative network by opening up additional pathways for excitation transfer. We show that these are processes that lead to the inhibition of destructive interference and exploitation of line broadening effects. We illustrate how these mechanisms operate on a fully connected network by developing a powerful analytical technique that identifies the invariant (excitation trapping) subspaces of a given Hamiltonian. Finally, we show how these principles can explain the remarkable efficiency and robustness of excitation energy transfer from the light-harvesting chlorosomes to the bacterial reaction center in photosynthetic complexes and present a numerical analysis of excitation transport across the Fenna-Matthew-Olson (FMO) complex together with a brief analysis of its entanglement properties. Our results show that, in general, it is the careful interplay of quantum mechanical features and the unavoidable environmental noise that will lead to an optimal system performance.

Filippo Caruso; Alex W. Chin; Animesh Datta; Susana F. Huelga; Martin B. Plenio

2009-01-28T23:59:59.000Z

468

Kalispel Non-Native Fish Suppression Project 2007 Annual Report.  

DOE Green Energy (OSTI)

Non-native salmonids are impacting native salmonid populations throughout the Pend Oreille Subbasin. Competition, hybridization, and predation by non-native fish have been identified as primary factors in the decline of some native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarki lewisi) populations. In 2007, the Kalispel Natural Resource Department (KNRD) initiated the Kalispel Nonnative Fish Suppression Project. The goal of this project is to implement actions to suppress or eradicate non-native fish in areas where native populations are declining or have been extirpated. These projects have previously been identified as critical to recovering native bull trout and westslope cutthroat trout (WCT). Lower Graham Creek was invaded by non-native rainbow (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) after a small dam failed in 1991. By 2003, no genetically pure WCT remained in the lower 700 m of Graham Creek. Further invasion upstream is currently precluded by a relatively short section of steep, cascade-pool stepped channel section that will likely be breached in the near future. In 2008, a fish management structure (barrier) was constructed at the mouth of Graham Creek to preclude further invasion of non-native fish into Graham Creek. The construction of the barrier was preceded by intensive electrofishing in the lower 700 m to remove and relocate all captured fish. Westslope cutthroat trout have recently been extirpated in Cee Cee Ah Creek due to displacement by brook trout. We propose treating Cee Cee Ah Creek with a piscicide to eradicate brook trout. Once eradication is complete, cutthroat trout will be translocated from nearby watersheds. In 2004, the Washington Department of Fish and Wildlife (WDFW) proposed an antimycin treatment within the subbasin; the project encountered significant public opposition and was eventually abandoned. However, over the course of planning this 2004 project, little public involvement or education was conducted prior to the planned implementation. Therefore, in 2007 we implemented an extensive process to provide public education, address public concerns and provide opportunity for public involvement in implementing piscicides and other native fish recovery actions in the subbasin.

Wingert, Michele; Andersen, Todd [Kalispel Natural Resource Department

2008-11-18T23:59:59.000Z

469

Noise Out of Chaos and Why it Won't Go Away  

Science Conference Proceedings (OSTI)

It seems that stochastic climate models are beginning to be fashionable. In this article, current theories of where noise comes from, its relation to chaos, and how temperamental a numerical treatment of noise in a climate model can be are all ...

Cécile Penland

2003-07-01T23:59:59.000Z

470

Comparative study of gigahertz CMOS LC quadrature voltage-controlled oscillators with relevance to phase noise  

Science Conference Proceedings (OSTI)

This review paper presents a comparative study of published integrated submicron CMOS quadrature voltage-controlled oscillator designs, based on LC resonator tanks operating at gigahertz frequencies. Although special reference to phase noise reduction ... Keywords: LC tanks, Phase noise, Quadrature VCO, RF CMOS circuits

Owen Casha; Ivan Grech; Joseph Micallef

2007-08-01T23:59:59.000Z

471

A measurement fixture suitable for measuring substrate noise in the UWB frequency band  

Science Conference Proceedings (OSTI)

This paper presents a measurement fixture suitable for measuring substrate carried noise for lightly doped substrates within the UWB frequency band. Signals coupling through the substrate are usually fairly weak and special precautions are taken to avoid ... Keywords: GSG, Substrate noise, UWB, Wide band measurements

Ming Shen; Tian Tong; Jan H. Mikkelsen; Torben Larsen

2009-01-01T23:59:59.000Z

472

Simultaneous switching noise in on-chip CMOS power distribution networks  

Science Conference Proceedings (OSTI)

Simultaneous switching noise (SSN) has become an important issue in the design of the internal on-chip power distribution networks in current very large scale integration/ultra large scale integration (VLSI/ULSI) circuits. An inductive model is used ... Keywords: integrated circuit interconnection, on-chip inductance, power distribution network, simultaneous switching noise

Kevin T. Tang; Eby G. Friedman

2002-08-01T23:59:59.000Z

473

Modeling and simulation of substrate noise in mixed-signal circuits applied to a special VCO  

Science Conference Proceedings (OSTI)

The mixed-signal circuits with both analog and digital blocks on a single chip have wide applications in communication and RF circuits. Integrating these two blocks can cause serious problems especially in applications with fast digital circuits and ... Keywords: Green's function, VCO, mixes-signal circuits, phase noise, substrate noise

Golnar Khodabandehloo; Sattar Mirzakuchaki

2006-09-01T23:59:59.000Z

474

Noise-robust edge detector combining isotropic and anisotropic Gaussian kernels  

Science Conference Proceedings (OSTI)

A new noise-robust edge detector is proposed, which combines a small-scaled isotropic Gaussian kernel and large-scaled anisotropic Gaussian kernels (ANGKs) to obtain edge maps of images. Its main advantage is that noise reduction is attained while maintaining ... Keywords: Anisotropic Gaussian kernels (ANGKs), Anisotropic directional derivatives, Edge detection, Edge resolution, Edge stretch effect

Peng-Lang Shui; Wei-Chuan Zhang

2012-02-01T23:59:59.000Z

475

Underwater temporary threshold shift in pinnipeds: Effects of noise level and duration  

E-Print Network (OSTI)

Underwater temporary threshold shift in pinnipeds: Effects of noise level and duration David Kastak psychophysical techniques were used to evaluate the residual effects of underwater noise on the hearing , amplified Realis- tic MPA-20 , and projected from one of two underwater transducers NUWC J-9 or Lubell

Reichmuth, Colleen

476

Underwater temporary threshold shift induced by octave-band noise in three species of pinniped  

E-Print Network (OSTI)

Underwater temporary threshold shift induced by octave-band noise in three species of pinniped at center frequency . Each subject was trained to dive into a noise field and remain stationed underwater airborne. When human divers were tested underwater, for instance, the resultant levels of TTS were much

Reichmuth, Colleen

477

On the reduction of thermal and flicker noise in ENG signal recording amplifiers  

Science Conference Proceedings (OSTI)

Because of the extremely low amplitude of the input signal, the design of electro-neuro-graph (ENG) amplifiers involves a special care for flicker and thermal noise reduction. The task becomes really challenging in the case of implantable electronics, ... Keywords: Analog design techniques, CMOS, Low-noise, Low-power

Joel Gak; Matías Miguez; Martín Bremermann; Alfredo Arnaud

2008-11-01T23:59:59.000Z

478

Signal Amplification by 1/f Noise in Silicon-Based Nanomechanical  

E-Print Network (OSTI)

Publication: This article was published ASAP on August 17, 2009. An Acknowledgment has been added to the paper resonators has been observed only in presence of white noise.13,14 Even though these studies established in the value of 0, switching does not occur. By adding noise to a subthreshold phase deviation signal, we

479

Comparison of the calculated neutron noise using finite differences and the Analytical Nodal Method  

E-Print Network (OSTI)

noise in the frequency domain via the reactor transfer function using 2-group diffusion theory in 2 Viktor Larsson , Christophe Demazière Chalmers University of Technology, Department of Nuclear: Neutron noise ANM Finite differences 2-group theory a b s t r a c t In this paper, a comparison

Demazière, Christophe

480

Measuring Coastal Boating Noise to Assess Potential Impacts on Marine Life  

SciTech Connect

Article requested for submission in Sea Technology Magazine describing the Underwater Noise From Small Boats. An Overlooked Component of the Acoustic Environment in Coastal Areas. Underwater noise and its effects on marine life deserve attention as human activity in the marine environment increases. Noise can affect fish and marine mammals in ways that are physiological, as in auditory threshold shifts, and behavioral, as in changes in foraging habits. One anthropogenic source of underwater noise that has received little attention to date is recreational boating. Coastal areas and archipelago regions, which play a crucial role in the marine ecosystem, are often subject to high levels of boat traffic. In order to better understand the noise produced by a small powerboat, a test was conducted in Sequim Bay, Washington, using an instrumented research vessel and multiple acoustic sensors. The broadband noise and narrowband peak levels were observed from two different locations while the boat was operated under various conditions. The results, combined with background noise levels, sound propagation and local boat traffic patterns, can provide a picture of the total boating noise to which marine life may be subjected.

Matzner, Shari; Jones, Mark E.

2011-07-01T23:59:59.000Z