National Library of Energy BETA

Sample records for magnet ac synchronous

  1. Dynamic magnetization states of a spin valve in the presence of dc and ac currents: Synchronization, modification, and chaos

    E-Print Network [OSTI]

    Li, Charles

    Dynamic magnetization states of a spin valve in the presence of dc and ac currents: Synchronization and numerical calculations of dynamic magnetization states of a spin valve in the presence of dc and ac currents are expected to appear. In this paper, we consider a simple spin valve as a model system to study the problem

  2. Magnetic switch coupling to synchronize magnetic modulators

    DOE Patents [OSTI]

    Reed, Kim W. (Albuquerque, NM); Kiekel, Paul (Albuquerque, NM)

    1999-01-01

    Apparatus for synchronizing the output pulses from a pair of magnetic switches. An electrically conductive loop is provided between the pair of switches with the loop having windlings about the core of each of the magnetic switches. The magnetic coupling created by the loop removes voltage and timing variations between the outputs of the two magnetic switches caused by any of a variety of factors. The only remaining variation is a very small fixed timing offset caused by the geometry and length of the loop itself.

  3. Magnetic switch coupling to synchronize magnetic modulators

    DOE Patents [OSTI]

    Reed, K.W.; Kiekel, P.

    1999-04-27

    Apparatus for synchronizing the output pulses from a pair of magnetic switches is disclosed. An electrically conductive loop is provided between the pair of switches with the loop having windings about the core of each of the magnetic switches. The magnetic coupling created by the loop removes voltage and timing variations between the outputs of the two magnetic switches caused by any of a variety of factors. The only remaining variation is a very small fixed timing offset caused by the geometry and length of the loop itself. 13 figs.

  4. Permanent-magnet-less synchronous reluctance system

    DOE Patents [OSTI]

    Hsu, John S

    2012-09-11

    A permanent magnet-less synchronous system includes a stator that generates a magnetic revolving field when sourced by an alternating current. An uncluttered rotor is disposed within the magnetic revolving field and spaced apart from the stator to form an air gap relative to an axis of rotation. The rotor includes a plurality of rotor pole stacks having an inner periphery biased by single polarity of a north-pole field and a south-pole field, respectively. The outer periphery of each of the rotor pole stacks are biased by an alternating polarity.

  5. Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines Seong (FEA). Also, this method can be applied to any type of synchronous machine. Index Terms-- equivalent circuit, inductance, permanent magnet machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless

  6. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOE Patents [OSTI]

    Coffey, Howard T. (Darien, IL)

    1993-01-01

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  7. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOE Patents [OSTI]

    Coffey, H.T.

    1993-10-19

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

  8. Determination of Rotor Temperature for an Interior Permanent Magnet Synchronous

    E-Print Network [OSTI]

    Noé, Reinhold

    of the magnet material monitoring its temperature also helps to increase the accuracy of the estimated torque [1Determination of Rotor Temperature for an Interior Permanent Magnet Synchronous Machine Using@lea.upb.de, boecker@lea.upb.de Abstract--In this paper an enhanced method to de- termine the rotor temperature

  9. Direct Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal Efficiency

    E-Print Network [OSTI]

    Noé, Reinhold

    applications. Highly utilized machines are often designed as interior permanent magnet synchronous motorsDirect Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal@lea.upb.de, boecker@lea.upb.de URL: http://wwwlea.upb.de Keywords «Interior permanent magnet synchronous motor

  10. Robust Timing Synchronization for AC-OFDM Based Optical Wireless Communications

    E-Print Network [OSTI]

    Ranjha, Bilal A; Kavehrad, Mohsen; Deng, Peng

    2015-01-01

    Visible light communications (VLC) have recently attracted a growing interest and can be a potential solution to realize indoor wireless communication with high bandwidth capacity for RF-restricted environments such as airplanes and hospitals. Optical based orthogonal frequency division multiplexing (OFDM) systems have been proposed in the literature to combat multipath distortion and intersymbol interference (ISI) caused by multipath signal propagation. In this paper, we present a robust timing synchronization scheme suitable for asymmetrically clipped (AC) OFDM based optical intensity modulated direct detection (IM/DD) wireless systems. Our proposed method works perfectly for ACO-OFDM, Pulse amplitude modulated discrete multitone (PAM-DMT) and discrete Hartley transform (DHT) based optical OFDM systems. In contrast to existing OFDM timing synchronization methods which are either not suitable for AC OFDM techniques due to unipolar nature of output signal or perform poorly, our proposed method is suitable for...

  11. Aalborg Universitet Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator

    E-Print Network [OSTI]

    Hu, Weihao

    Aalborg Universitet Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Synchronous Generator Variable-Speed Wind Turbines. Energies, 6(8), 3807-3821. 10.3390/en6083807 General.mdpi.com/journal/energies Article Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Variable-Speed Wind

  12. Harmonic mixing in two coupled qubits: quantum synchronization via ac drives

    E-Print Network [OSTI]

    S. E. Savel'ev; Z. Washington; A. M. Zagoskin; M. J. Everitt

    2012-10-12

    Simulating a system of two driven coupled qubits, we show that the time-averaged probability to find one driven qubit in its ground or excited state can be controlled by an ac drive in the second qubit. Moreover, off-diagonal elements of the density matrix responsible for quantum coherence can also be controlled via driving the second qubit, i.e., quantum coherence can be enhanced by appropriate choice of the bi-harmonic signal. Such a dynamic synchronization of two differently driven qubits has an analogy with harmonic mixing of Brownian particles forced by two signals through a substrate. Nevertheless, the quantum synchronization in two qubits occurs due to multiplicative coupling of signals in the qubits rather than via a nonlinear harmonic mixing for a classical nano-particle.

  13. Optimum Control for Interior Permanent Magnet Synchronous Motors (IPMSM) in Constant

    E-Print Network [OSTI]

    Noé, Reinhold

    Optimum Control for Interior Permanent Magnet Synchronous Motors (IPMSM) in Constant Torque and Electrical Drives, Paderborn, Germany Abstract--Interior Permanent Magnet Synchronous Motors (IPMSM) gain-power speed area. A widespread electrical machine used for this purpose is the Interior Permanent Magnet

  14. Monitoring Critical Temperatures in Permanent Magnet Synchronous Motors Using Low-Order

    E-Print Network [OSTI]

    Noé, Reinhold

    Monitoring Critical Temperatures in Permanent Magnet Synchronous Motors Using Low-Order Thermal motors is crucial for preventing shortened motor life spans due to excessive thermal stress. With regard to interior permanent magnet synchronous motors (IPMSM), critical temperatures typically occur in the magnets

  15. Dynamic Motor Parameter Identification for High Speed Flux Weakening Operation of Brushless Permanent Magnet Synchronous Machines

    E-Print Network [OSTI]

    Szabados, Barna

    Permanent Magnet Synchronous Machines Abstract: An experimental investigation is conducted to determine the behaviour of brushless PM synchronous machine parameters in the high speed flux weakening operating range synchronous machines. Special computer assisted measuring techniques are employed using an experimental vector

  16. Study of Various Slanted Air-gap Structures of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    E-Print Network [OSTI]

    Tolbert, Leon M.

    magnet machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless field excitation IPMSM interiorStudy of Various Slanted Air-gap Structures of Interior Permanent Magnet Synchronous Motor of the slanted air-gap structure of an interior permanent magnet synchronous motor with brushless field

  17. Analysis of Slanted Air-gap Structure of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    E-Print Network [OSTI]

    Tolbert, Leon M.

    machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless field excitation IPMSM interiorAnalysis of Slanted Air-gap Structure of Interior Permanent Magnet Synchronous Motor with Brushless permanent magnet synchronous motor (IPMSM) for application in a hybrid electric vehicle. This unique slanted

  18. Power-Factor and Torque Calculation with Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with

    E-Print Network [OSTI]

    Tolbert, Leon M.

    OF IPMSM Below is the well-known electromagnetic torque equation for all synchronous machines: dqqd iip Permanent Magnet Synchronous Motor with Brushless Field Excitation Seong Taek Lee1,2 , Timothy A. Burress1 permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include

  19. Minimizing Wheel Slip in Railway Locomotives with Coupled Permanent Magnet Synchronous Motors

    E-Print Network [OSTI]

    Shayak Bhattacharjee

    2015-01-17

    In this work I consider control strategies of permanent magnet synchronous motors in which the back-emf signal from the motor is used to achieve commutation of the six step driving circuit. I show that if the strategy is modified to connect multiple motors in a cyclic chain, then a collective synchronized state is favoured. The stability of this state can be exploited in the bogies of a railway locomotive to automatically terminate wheel slipping episodes.

  20. Performance improvement of permanent magnet ac motors 

    E-Print Network [OSTI]

    Parsa, Leila

    2005-08-29

    positively to output torque, a five-phase permanent magnet motor with quasi-rectangular back-EMF waveform is supplied with combined fundamental and third harmonic of currents. For modeling and analysis of the motor a 0 3 3 1 1 q d q d frame of reference...

  1. Synchronization of an array of spin torque nano oscillators in periodic applied external magnetic field

    E-Print Network [OSTI]

    B. Subash; V. K. Chandrasekar; M. Lakshmanan

    2013-04-03

    Considering an array of spin torque transfer nano oscillators (STNOs), we have investigated the synchronization property of the system under the action of a common periodically driven applied external magnetic field by numerically analyzing the underlying system of Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equations for the macro-spin variables. We find the novel result that the applied external magnetic field can act as a medium to induce synchronization of periodic oscillations, both in-phase and anti-phase, even without coupling through spin current, thereby leading to the exciting possibility of enhancement of microwave power in a straightforward way.

  2. FLUXCAP: A flux-coupled ac/dc magnetizing device

    E-Print Network [OSTI]

    Gopman, Daniel B; Kent, Andrew D

    2012-01-01

    We report on an instrument for applying ac and dc magnetic fields by capturing the flux from a rotating permanent magnet and projecting it between two adjustable pole pieces. This can be an alternative to standard electromagnets for experiments with small samples or in probe stations in which an applied magnetic field is needed locally, with advantages that include a compact form-factor, very low power requirements and dissipation as well as fast field sweep rates. This flux capture instrument (FLUXCAP) can produce fields from -400 to +400 mT, with field resolution less than 1 mT. It generates static magnetic fields as well as ramped fields, with ramping rates as high as 10 T/s. We demonstrate the use of this apparatus for studying the magnetotransport properties of spin-valve nanopillars, a nanoscale device that exhibits giant magnetoresistance.

  3. Control Realization for an Interior Permanent Magnet Synchronous Motor (IPMSM) in Automotive Drive Trains

    E-Print Network [OSTI]

    Noé, Reinhold

    Control Realization for an Interior Permanent Magnet Synchronous Motor (IPMSM) in Automotive Drive, the Maximal Torque Per Current (MTPC) method provides appropriate results. The requested torque is generated higher drive efficiency. The requested torque is generated with a minimum of total losses, which

  4. Design of a High Performance Ferrite Magnet-Assisted Synchronous Reluctance Motor for an

    E-Print Network [OSTI]

    Noé, Reinhold

    and Electrical Drives Paderborn University 33098 Paderborn, Germany Abstract-- A high performance 55kW (peak-transportation along with rising crude prices have led to renewed interest in electric transportation infrastructureDesign of a High Performance Ferrite Magnet- Assisted Synchronous Reluctance Motor for an Electric

  5. Enhanced synchronization in an array of spin torque nano oscillators in the presence of oscillating external magnetic field

    E-Print Network [OSTI]

    B. Subash; V. K. Chandrasekar; M. Lakshmanan

    2014-12-23

    We demonstrate that the synchronization of an array of electrically coupled spin torque nano-oscillators (STNO) modelled by Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation can be enhanced appreciably in the presence of a common external microwave magnetic field. The applied microwave magnetic field stabilizes and enhances the regions of synchronization in the parameter space of our analysis, where the oscillators are exhibiting synchronized oscillations thereby emitting improved microwave power. To characterize the synchronized oscillations we have calculated the locking range in the domain of external source frequency.

  6. The role of eddy currents and nanoparticle size on AC magnetic fieldinduced reflow in solder/magnetic nanocomposites

    E-Print Network [OSTI]

    McHenry, Michael E.

    The role of eddy currents and nanoparticle size on AC magnetic field­induced reflow in solder://jap.aip.org/about/rights_and_permissions #12;The role of eddy currents and nanoparticle size on AC magnetic field­induced reflow in solder be derived from eddy current losses in Cu planes in the substrate board. Eddy current heating in Cu sheets

  7. Design and Empirical Identification of a Lumped Parameter Thermal Network for Permanent Magnet Synchronous Motors with Physically

    E-Print Network [OSTI]

    Noé, Reinhold

    Synchronous Motors with Physically Motivated Constraints Oliver Wallscheid, Student Member, IEEE, Joachim B¨ocker, Senior Member, IEEE Abstract--Monitoring critical temperatures in permanent magnet synchronous motors (PMSM) is essential to prevent device failures or excessive motor life time reduction due to thermal

  8. Exotic magnetic response of superconducting wires subject to synchronous and asynchronous oscillating excitations

    E-Print Network [OSTI]

    Majós, Antonio Badía

    of the injected transport current lines. Finally, we have shown that the strong localization of the power density-scale technological applications such as power transmission cables, magnet systems for large particle accelerators of electric power dissipation due to alternating fields and/or alternating current flow (commonly called ac

  9. Analytical modeling of a new disc permanent magnet linear synchronous machine for electric vehicles

    SciTech Connect (OSTI)

    Liu, C.T.; Chen, J.W.; Su, K.S.

    1999-09-01

    This paper develops an analytical approach based on a qd0 reference frame model to analyze dynamic and steady state characteristics of disc permanent magnet linear synchronous machines (DPMLSMs). The established compact mathematical model can be more easily employed to analyze the system behavior and to design the controller. Superiority in operational electromagnetic characteristics of the proposed DPMLSM for electric vehicle (EV) applications is verified by both numerical simulations and experimental investigations.

  10. Optimal current control strategies for surface-mounted permanent-magnet synchronous machine drives

    SciTech Connect (OSTI)

    Chapman, P.L.; Sudhoff, S.D.; Whitcomb, C.A.

    1999-12-01

    The current waveforms for optimal excitation of surface-mounted permanent-magnet synchronous machines are set forth. Four different modes are considered, involving varying degrees of minimization of rms current and torque ripple. The optimized waveforms are markedly different than the traditional sinusoidal or rectangular excitation schemes. Inclusion of cogging torque and arbitrary degree of torque ripple minimization generalize this work over that of previous authors. An experimental drive and a detailed computer simulation verify the proposed control schemes.

  11. AC losses in type-II superconductors induced by nonuniform fluctuations of external magnetic field

    E-Print Network [OSTI]

    as the economic gains of implementation of type-II superconductors in power transmission lines, current leads amplitude. The results can be used to estimate the AC losses in flywheels, electric motors, magnetic shields

  12. Design of low-power permanent-magnet synchronous motor for use in high-density heat pump

    E-Print Network [OSTI]

    Jenicek, David P. (David Pierre)

    2011-01-01

    An analytical model for the functionality of a permanent-magnet synchronous motor is developed. Taking as input a specific geometry, it predicts steady-state losses of a design at an average rate of 0.85 seconds per analysis, ...

  13. Adaptive fuzzy dynamic surface control for the chaotic permanent magnet synchronous motor using Nussbaum gain

    SciTech Connect (OSTI)

    Luo, Shaohua [School of Automation, Chongqing University, Chongqing 400044, China and College of Mechanical Engineering, Hunan University of Arts and Science, Hunan 415000 (China)

    2014-09-01

    This paper is concerned with the problem of adaptive fuzzy dynamic surface control (DSC) for the permanent magnet synchronous motor (PMSM) system with chaotic behavior, disturbance and unknown control gain and parameters. Nussbaum gain is adopted to cope with the situation that the control gain is unknown. And the unknown items can be estimated by fuzzy logic system. The proposed controller guarantees that all the signals in the closed-loop system are bounded and the system output eventually converges to a small neighborhood of the desired reference signal. Finally, the numerical simulations indicate that the proposed scheme can suppress the chaos of PMSM and show the effectiveness and robustness of the proposed method.

  14. Computer Based Motor Parameter Determination for High Speed Operation of Permanent Magnet Synchronous Machines

    E-Print Network [OSTI]

    Szabados, Barna

    Synchronous Machines B. Szabados and U. Schaible McMaster University 1280 Main St. W., Hamilton, Ontario PM synchronous machine parameters in the high speed operating range. The theory and real interior PM synchronous machine at up to 8000 rpm. Results are presented which show a significant variation

  15. Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and

    E-Print Network [OSTI]

    Shaw, Leah B.

    Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films on superconductors. The high time and spatial resolutions of the measurements also offer good quantitative data analysis of the MO images. Y Ba2Cu3O7-8 (YBCO) was discovered as a high-temperature superconductor (HTSC

  16. Calculation of synchronous reactances of small permanent-magnet alternating-current motors: Comparison of analytical approach and finite element method with measurements

    SciTech Connect (OSTI)

    Gieras, J.F.; Wing, M. [Univ. of Cape Town, Rondebosch (South Africa). Dept. of Electrical Engineering] [Univ. of Cape Town, Rondebosch (South Africa). Dept. of Electrical Engineering; Santini, E. [Univ. of Rome (Italy). Dept. of Electrical Engineering] [Univ. of Rome (Italy). Dept. of Electrical Engineering

    1998-09-01

    The synchronous reactances of permanent magnet (PM) motors have been determined using: (1) analytical method, i.e., form factors of the stator field (armature reaction factors), (2) finite element method (FEM), and (3) experimental tests on a special machine set. The analytical method is widely used in calculations of synchronous reactances of salient pole synchronous machines with electromagnetic excitation. Rotors of PM synchronous machines have more complicated structures, hence it is more difficult to predict accurately the magnetic field distribution in their airgaps in order to find the form factors of the stator field. Numerical methods of field analysis can easily solve this problem. The FEM can predict both the synchronous and mutual (armature reaction) reactances in the d and q axes. The leakage reactance can then be evaluated as a difference between synchronous and mutual reactances. As an example, a small, three-phase, four-pole motor with SmCo surface mounted PM`s (three parallel magnets per pole), and mild-steel pole shoes has been investigated. Such a complicated rotor structure has been intentionally designed in order to be able to compare the advantages and disadvantages of the analytical method and the FEM. In the FEM, the reactances have been calculated using both the flux linkage and current/energy perturbation method. Synchronous reactances as functions of the stator current and load angle obtained analytically from the FEM modeling and from measurements have been compared.

  17. Synchronicity from synchronized chaos

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

    Duane, Gregory

    2015-04-01

    The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related events mysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical) correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind andmore »matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1) synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2) the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable) interpretations if the quantum world resides on a generalized synchronization “manifold”.« less

  18. Synchronicity from synchronized chaos

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

    Duane, Gregory [Univ. of Colorado, Boulder, CO (United States); Macedonia Academy of Sciences and Arts, Skopje (Macedonia); Univ. of Bergen, Bergen (Norway)

    2015-04-01

    The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related events mysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical) correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind and matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1) synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2) the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable) interpretations if the quantum world resides on a generalized synchronization “manifold”.

  19. Power-Factor Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    SciTech Connect (OSTI)

    Lee, Seong T [ORNL; Burress, Timothy A [ORNL; Hsu, John S [ORNL

    2009-01-01

    This paper introduces a new method for calculating the power factor with consideration of the cross saturation between the direct-axis (d-axis) and the quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross-saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at high speed, which was developed for the traction motor of a hybrid electric vehicle.

  20. The Synchronic Frame of Photospheric Magnetic Flux: The Improved Synoptic Frame

    E-Print Network [OSTI]

    Zhao, Xuepu

    of the middle panel). Because of the differential rotation of magnetic elements, the solar surface distribution from a synoptic chart do not cover the whole solar surface at any time within the period of one solar transpot models to predict better instantaneous photospheric field distribution on the portions of solar

  1. Noise reduction control strategy of a permanent magnet synchronous machine for vehicle applications 

    E-Print Network [OSTI]

    Doolittle, Randy Gene

    2009-05-15

    that was not available: 1. V S (secant voltage) or a phase voltage to give a value to the BackEMF (E) 2. L A , L B , L C (phase inductances), L S (secant inductance), or L D and L Q 3. M D ? (magnet flux linkage) or B G (air gap flux density) The thesis... T EM,rated d-q rated Torque 309Nm V S,rated Secant Voltage I S,rated,rms Secant Rated RMS Current 300A P ,rated Rated Machine Power P ,max Maximum Machine Power 64.5kW ? ,max Top Speed E Back EMF @ Top Speed 400V (assumed could be 600V...

  2. Idling Magnetic White Dwarf in the Synchronizing Polar BY Cam. The Noah-2 Project

    E-Print Network [OSTI]

    Ivan L. Andronov; Kirill A. Antoniuk; Vitalii V. Breus; Lidia L. Chinarova; Won Young Han; Young Beom Jeon; Yonggi Kim; Sergey V. Kolesnikov; Joon Young Oh; Elena P. Pavlenko; Nikolay M. Shakhovskoy

    2008-06-10

    Results of a multi-color study of the variability of the magnetic cataclysmic variable BY Cam are presented. The observations were obtained at the Korean 1.8m and Ukrainian 2.6m, 1.2m and 38-cm telescopes in 2003-2005, 56 observational runs cover 189 hours. The variations of the mean brightness in different colors are correlated with a slope dR/dV=1.29(4), where the number in brackets denotes the error estimates in the last digits. For individual runs, this slope is much smaller ranging from 0.98(3) to 1.24(3), with a mean value of 1.11(1). Near the maximum, the slope becomes smaller for some nights, indicating more blue spectral energy distribution, whereas the night-to-night variability has an infrared character. For the simultaneous UBVRI photometry, the slopes increase with wavelength from dU/dR=0.23(1) to dI/dR=1.18(1). Such wavelength dependence is opposite to that observed in non-magnetic cataclysmic variables, in an agreement to the model of cyclotron emission. The principal component analysis shows two (with a third at the limit of detection) components of variablitity with different spectral energy distribution, which possibly correspond to different regions of emission. The scalegram analysis shows a highest peak corresponding to the 200-min spin variability, its quarter and to the 30-min and 8-min QPOs. The amplitudes of all these components are dependent on wavelength and luminosity state. The light curves were fitted by a statistically optimal trigonometrical polynomial (up to 4-th order) to take into account a 4-hump structure. The dependences of these parameters on the phase of the beat period and on mean brightness are discussed. The amplitude of spin variations increases with an increasing wavelength and with decreasing brightness

  3. Power-Factor and Torque Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

    SciTech Connect (OSTI)

    Lee, Seong T [ORNL; Burress, Timothy A [ORNL; Tolbert, Leon M [ORNL

    2009-01-01

    This paper introduces a new method for calculating the power factor and output torque by considering the cross saturation between direct-axis (d-axis) and quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at high speed, which was developed for the traction motor of a hybrid electric vehicle. The conventional two-axis IPMSM model was modified to include the cross-saturation effect by adding the cross-coupled inductance terms Ldq and Lqd. By the advantage of the excited structure of the experimental IPMSM, the analyzing works were performed under two conditions, the highest and lowest excited conditions. Therefore, it is possible to investigate the cross-saturation effect when a machine has higher magnetic flux from its rotor. The following is a summary of conclusions that may be drawn from this work: (1) Considering cross saturation of an IPMSM offers more accurate expected values of motor parameters in output torque calculation, especially when negative d-axis current is high; (2) A less saturated synchronous machine could be more affected by the cross-coupled saturation effect; (3) Both cross-coupled inductances, L{sub qd} and L{sub dq}, are mainly governed by d-axis current rather than q-axis current; (4) The modified torque equation, can be used for the dynamic model of an IPMSM for developing a better control model or control strategy; and (5) It is possible that the brushless field excitation structure has a common magnetic flux path on both d- and q-axis, and as a result, the reluctance torque of the machine could be reduced.

  4. High-Performance Control of Two Three-Phase Permanent-Magnet Synchronous Machines in an Integrated Drive for Automotive Applications

    SciTech Connect (OSTI)

    Tang, Lixin [ORNL; Su, Gui-Jia [ORNL

    2008-01-01

    The closed-loop control of an integrated dual AC drive system is presented to control two three-phase permanent-magnet motors. A five-leg inverter is employed in the drive system; three of the inverter legs are for a main traction motor, but only two are needed for a three-phase auxiliary motor by utilizing the neutral point of the traction motor. An integrated drive with reduced component count is therefore achieved by eliminating one inverter leg and its gate drivers. A modified current control scheme based on the rotor flux orientation principle is presented. Simulation and experimental results are included to verify the independent control capability of the integrated drive.

  5. Abstract --For high-speed machines applications, eddy-current losses in the interior permanent magnet of synchronous

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Abstract -- For high-speed machines applications, eddy- current losses in the interior permanent carries out a prediction of eddy current losses in PM where the skin effect is considered. A complete by analytical method. Index Terms-- High speed, Permanent magnet machines, Eddy-currents, power losses, skin

  6. Regular and chaotic dynamics of a chain of magnetic dipoles with moments of inertia

    SciTech Connect (OSTI)

    Shutyi, A. M. [Ulyanovsk State University (Russian Federation)], E-mail: shuty@mail.ru

    2009-05-15

    The nonlinear dynamic modes of a chain of coupled spherical bodies having dipole magnetic moments that are excited by a homogeneous ac magnetic field are studied using numerical analysis. Bifurcation diagrams are constructed and used to find conditions for the presence of several types of regular, chaotic, and quasi-periodic oscillations. The effect of the coupling of dipoles on the excited dynamics of the system is revealed. The specific features of the Poincare time sections are considered for the cases of synchronous chaos with antiphase synchronization and asynchronous chaos. The spectrum of Lyapunov exponents is calculated for the dynamic modes of an individual dipole.

  7. Disrupted Neural Synchronization in Toddlers with Autism

    E-Print Network [OSTI]

    Behrmann, Marlene

    Neuron Report Disrupted Neural Synchronization in Toddlers with Autism Ilan Dinstein,1,4,* KarenAutism Center of Excellence 2Department of Psychiatry 3Department of Neurosciences University 15213, USA *Correspondence: ilan.dinstein@weizmann.ac.il DOI 10.1016/j.neuron.2011.04.018 SUMMARY Autism

  8. IEEE TRANSACTIONS ON MAGNETICS, VOL. 45, NO. 12, DECEMBER 2009 5399 Modeling of the Starting Performance of Large Solid-Pole Synchronous

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    refineries, steel mills, and power plants [1]­[6]. Large solid pole motors are a special category of large virtual windings. Therefore, the two-axis theory can be used for the solid pole synchronous motor. We, starting performance, transformation coefficient, two-axis theory, virtual windings. I. INTRODUCTION LARGE

  9. Fault tolerant pulse synchronization 

    E-Print Network [OSTI]

    Deconda, Keerthi

    2009-05-15

    Pulse synchronization is the evolution of spontaneous firing action across a network of sensor nodes. In the pulse synchronization model all nodes across a network produce a pulse, or "fire", at regular intervals even without access to a shared...

  10. Synchronization on nulticore architectures

    E-Print Network [OSTI]

    Harding, Rachael, S.M. Massachusetts Institute of Technology

    2014-01-01

    The rise of multicore computing has made synchronization necessary to overcome the challenge of sharing data between multiple threads. Locks are critical synchronization primitives for maintaining data integrity and ...

  11. Synchronous Reactive Systems Stephen Edwards

    E-Print Network [OSTI]

    -state machines 5 #12;STEPHEN EDWARDS SYNCHRONOUS REACTIVE SYSTEMS The Synchronous Model of Time SynchronousSynchronous Reactive Systems Stephen Edwards http://www.eecs.berkeley.edu/~sedwards/ University of California, Berkeley #12;STEPHEN EDWARDS SYNCHRONOUS REACTIVE SYSTEMS Outline Synchronous Reactive Systems

  12. Methods, systems and apparatus for synchronous current regulation of a five-phase machine

    DOE Patents [OSTI]

    Gallegos-Lopez, Gabriel; Perisic, Milun

    2012-10-09

    Methods, systems and apparatus are provided for controlling operation of and regulating current provided to a five-phase machine when one or more phases has experienced a fault or has failed. In one implementation, the disclosed embodiments can be used to synchronously regulate current in a vector controlled motor drive system that includes a five-phase AC machine, a five-phase inverter module coupled to the five-phase AC machine, and a synchronous current regulator.

  13. Efficient Barrier Synchronization Mechanism for the BSP Model on Message-Passing Architectures

    E-Print Network [OSTI]

    Ha, Soonhoi

    Efficient Barrier Synchronization Mechanism for the BSP Model on Message-Passing Architectures Jin-742, KOREA jinsoo, sha, csjhon¡ @comp.snu.ac.kr Abstract The Bulk Synchronous Parallel (BSP) model of computa- tion can be used to develop efficient and portable programs for a range of machines

  14. A Distributed Generation Control Architecture for Islanded AC Microgrids

    E-Print Network [OSTI]

    Dominguez-Garcia, Alejandro

    1 A Distributed Generation Control Architecture for Islanded AC Microgrids Stanton T. Cady, Student in islanded ac microgrids with both synchronous generators and inverter-interfaced power supplies. Although they are smaller and have lower ratings, the generation control objectives for an islanded microgrid are similar

  15. Aircraft AC Generators: Hybrid System Modeling and Simulation

    E-Print Network [OSTI]

    Koutsoukos, Xenofon D.

    generator, phase-domain model, synchronous AC generator. I. INTRODUCTION The Integrated Drive Generator (IDG1 Aircraft AC Generators: Hybrid System Modeling and Simulation Ashraf Tantawy, Student Member--Integrated Drive Generators (IDGs) are the main source of electrical power for a number of critical systems

  16. Nonlinear Electrical Simulation of High-Power Synchronous Generator System

    E-Print Network [OSTI]

    Wu, Thomas

    power density, the generator operates in nonlinear region of the magnetic circuit. Magnetic Finite for motor simulation [I]. Fardoun simulated permanent-magnet machine drive system using SPlCE [2]. NatarajanNonlinear Electrical Simulation of High-Power Synchronous Generator System Jie Chen and Thomas Wu

  17. Transient Uncoupling Induces Synchronization

    E-Print Network [OSTI]

    Malte Schröder; Manu Mannattil; Debabrata Dutta; Sagar Chakraborty; Marc Timme

    2015-08-26

    Finding conditions that support synchronization is a fertile and active area of research with applications across multiple disciplines. Here we present and analyze a scheme for synchronizing chaotic dynamical systems by transiently uncoupling them. Specifically, systems coupled only in a fraction of their state space may synchronize even if fully coupled they do not. Although, for many standard systems, coupling strengths need to be bounded to ensure synchrony, transient uncoupling removes this bound and thus enables synchronization in an infinite range of effective coupling strengths. The presented coupling scheme thus opens up the possibility to induce synchrony in (biological or technical) systems whose parameters are fixed and cannot be modified continuously.

  18. The Mesoscopic Synchronization

    E-Print Network [OSTI]

    Penny, Will

    The Mesoscopic Brain Will Penny Synchronization Phase Response Curves Phase Response Curves Hodgkin References The Mesoscopic Brain Will Penny 14th April 2011 #12;The Mesoscopic Brain Will Penny-to-spike synchrony and field synchrony are important. #12;The Mesoscopic Brain Will Penny Synchronization Phase

  19. english 31AC african-amercan studies 17AC history 7B public health 130AC sociology 3AC education 30AC ethnic studies 135AC geography 150AC history 127AC information 142AC psychology 125AC anthropology 2AC american

    E-Print Network [OSTI]

    Alvarez-Cohen, Lisa

    · anthropology 2AC · american studies 10AC · gender and womens studies 50AC · music 26AC · spanish 135AC 50AC · music 26AC · spanish 135AC · sociology 190AC · public policy 117AC · peace and conflict studies 10AC · gender and womens studies 50AC · music 26AC · spanish 135AC · sociology 190AC · public

  20. Indirect sensing for rotor flux position of permanent magnet AC motors operating over a wide speed range

    SciTech Connect (OSTI)

    Moreira, J.C.

    1996-11-01

    This paper describes an indirect sensing, or sensorless, method for rotor flux position for brushless permanent magnet (BPM) motors operating over a wide speed range, while keeping maximum torque per ampere and/or maximum efficiency capabilities. The method described is particularly applicable to trapezoidal back emf type of BPM motors. The typical trapezoidal waveform of the motor internal voltages (or back emf) contains a fundamental and higher order frequency harmonics. In particular, the third harmonic component is extracted from the stator phase voltages while the fundamental and other polyphase components are eliminated via a simple summation of the three phase voltages. The resulting third harmonic signal keeps a constant phase relationship with the rotor flux for any motor speed and load condition, and is practically free of noise that can be introduced by the inverter switching, making this a robust sensing method. In contrast with indirect sensing methods based on detection of the back-emf signal that require heavy filtering, the third harmonic signal needs only a small amount of filtering to eliminate the switching frequency and its side bands. As a result, the method described here is not sensitive to filtering delays, allowing the motor to achieve a good performance over a wide speed range. Motor starting is also superior with this method since the third harmonic signal can be detected and processed at lower speeds than for the conventional method of back-emf sensing. Moreover, an alternative way to acquire the third harmonic signal without the need to access the stator neutral terminal is discussed. This is particularly interesting with the motor neutral connection is not available or expensive to have access. The third harmonic indirect sensing scheme is implemented in the laboratory and compared to a conventional back-emf sensing method.

  1. Experimental Approach of a High Performance Control of Two PermanentMagnet Synchronous Machines in an Integrated Drive for Automotive Applications

    SciTech Connect (OSTI)

    Tang, Lixin; Su, Gui-Jia

    2006-01-01

    The close-loop digital signal processor (DSP) control of an integrated-dual inverter, which is able to drive two permanent magnet (PM) motors independently, is presented and evaluated experimentally. By utilizing the neutral point of the main traction motor, only two inverter poles are needed for the two-phase auxiliary motor. The modified field-oriented control scheme for this integrated inverter was introduced and employed in real-time control. The experimental results show the inverter is able to control two drives independently. An integrated, component count reduced drive is achieved.

  2. Investigation of magnetic spin glass property in La{sub 0.5}Bi{sub 0.5}MnO{sub 3} sample using non-linear AC susceptibility measurements

    SciTech Connect (OSTI)

    Kumar, Punith V. Manju, M. R. Dayal, Vijaylakshmi

    2014-04-24

    We present a comprehensive study on origin of Spin Glass (SG) property in polycrystalline La{sub 0.5}Bi{sub 0.5}MnO{sub 3} perovskite oxide using linear and higher order ac susceptibility (?) measurements. The third order harmonic susceptibility (?{sub 3}) vs. temperature (K) with varying magnetic fields from 0.95 to 9.45 Oe and the divergence in their ?{sub 3} (max) allows us to infer the SG behavior occurring in the sample possibly due to co-operative freezing of the spins.

  3. Power Supply Synchronization without Communication

    E-Print Network [OSTI]

    Hespanha, João Pedro

    the dynamical behavior of interconnected synchronous generators. I. INTRODUCTION The problem of interconnecting parameters, a newly added power plant generator naturally synchronizes with a previously synchro- nized1 Power Supply Synchronization without Communication Leonardo A. B. T^orres, Jo~ao P. Hespanha

  4. Advanced synchronous luminescence system

    DOE Patents [OSTI]

    Vo-Dinh, T.

    1997-02-04

    A method and apparatus are disclosed for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition. 14 figs.

  5. We study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film by using time

    E-Print Network [OSTI]

    Shaw, Leah B.

    -TC superconductors. The focus of our research is on dynamical processes (electronic, magnetic, and vibrational

  6. Completion of the US NHMFL 60 T quasi-continuous magnet

    SciTech Connect (OSTI)

    Sims, J.R.; Boenig, H.J.; Campbell, L.J.; Rickel, D.G.; Rogers, J.D.; Schillig, J.B. |; Schneider-Muntau, H.J.

    1997-10-01

    This is a technical summary report of the 60 T controlled power research magnet that was designed, assembled, installed and recently commissioned at the National High Magnetic Field Laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The magnet is a innovative in its design, construction, size, operation and power supply. The magnet consists of nine nested, mechanically independent, free standing coils, each of which is enclosed by a steel reinforcing shell. Using inertial energy storage a synchronous motor-generator provides ac power to a set of five ac-dc converters rated at 64 MW/87.6 MVA each. These converters energize three independent coil circuits to create 90 MJ of field energy at the maximum field of 60 T, which can be sustained for 100 ms in the 32 mm bore. Prior to a pulse the 4-ton magnet is cooled to liquid nitrogen temperature, a procedure that is achieved in less than one hour by the free flow of nitrogen between the nine coils. In addition to being the most powerful of its class in the world the magnet is also the first of its kind in the US. The operation of the magnet will be described along with special features of its design and construction. A sampling of the pulse shapes that can be obtained for research will be shown.

  7. MODELING OF EDDY CURRENT LOSS AND TEMPERATURE OF THE MAGNETS

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    MODELING OF EDDY CURRENT LOSS AND TEMPERATURE OF THE MAGNETS IN PERMANENT MAGNET MACHINES the performance of the machine. This paper presents the modeling and analysis of eddy current loss in surface- mounted-magnets PM synchronous motors (SPMSM) and interior-magnets PM synchronous motors (IPMSM), operated

  8. Position sensor for linear synchronous motors employing halbach arrays

    DOE Patents [OSTI]

    Post, Richard Freeman

    2014-12-23

    A position sensor suitable for use in linear synchronous motor (LSM) drive systems employing Halbach arrays to create their magnetic fields is described. The system has several advantages over previously employed ones, especially in its simplicity and its freedom from being affected by weather conditions, accumulated dirt, or electrical interference from the LSM system itself.

  9. Fast and rewritable colloidal assembly via field synchronized particle swapping

    E-Print Network [OSTI]

    Pietro Tierno; Tom H. Johansen; Thomas M. Fischer

    2015-07-07

    We report a technique to realize reconfigurable colloidal crystals by using the controlled motion of particle defects above an externally modulated magnetic substrate. The transport of particles is induced by applying a uniform rotating magnetic field to a ferrite garnet film characterized by a periodic lattice of magnetic bubbles. For filling factor larger than one colloid per bubble domain, the particle current arises from propagating defects where particles synchronously exchange their position when passing from one occupied domain to the next. The amplitude of an applied alternating magnetic field can be used to displace the excess particles via a swapping mechanism, or to mobilize the entire colloidal system at a predefined speed.

  10. Synchronous Machines 1.0 Introduction

    E-Print Network [OSTI]

    McCalley, James D.

    1 Synchronous Machines 1.0 Introduction One might easily argue that the synchronous generator is the most important component in the power system, since synchronous generators · Are the source of 99 the remainder of the course studying this component. EE 303 contains a chapter on synchronous generators (Module

  11. Communication using Synchronized Chaotic Systems

    E-Print Network [OSTI]

    Anlage, Steven

    Communication using Synchronized Chaotic Systems Rachel Kramer Adam Cohen Bhargava Ravoori Thomas E the adaptive strategy implemented. communications · Such systems are sensitive to perturbations · Communications systems are sensitive to perturbations in the communication channel · An adaptive strategy has

  12. Optimal synchronization of complex networks

    E-Print Network [OSTI]

    Per Sebastian Skardal; Dane Taylor; Jie Sun

    2014-10-17

    We study optimal synchronization in networks of heterogeneous phase oscillators. Our main result is the derivation of a synchrony alignment function that encodes the interplay between network structure and oscillators' frequencies and can be readily optimized. We highlight its utility in two general problems: constrained frequency allocation and network design. In general, we find that synchronization is promoted by strong alignments between frequencies and the dominant Laplacian eigenvectors, as well as a matching between the heterogeneity of frequencies and network structure.

  13. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S. (Oak Ridge, TN)

    2012-02-07

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  14. Permanent-magnet-less machine having an enclosed air gap

    DOE Patents [OSTI]

    Hsu, John S.

    2013-03-05

    A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

  15. A new model of saturated synchronous machines for power system transient stability simulations

    SciTech Connect (OSTI)

    Tamura, J.; Takeda, I. [Kitami Inst. of Tech., Hokkaido (Japan)] [Kitami Inst. of Tech., Hokkaido (Japan)

    1995-06-01

    This paper presents a new method to express the main flux saturation in synchronous machines. In the new method, the saturation is expressed by auxiliary currents and unsaturated magnetizing inductances instead of the saturated inductances. The new model using the currents contains only constant coefficients defined in terms of the unsaturated magnetizing inductances.

  16. Optimization of spin-torque switching using AC and DC pulses

    SciTech Connect (OSTI)

    Dunn, Tom [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Kamenev, Alex [Department of Physics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2014-06-21

    We explore spin-torque induced magnetic reversal in magnetic tunnel junctions using combined AC and DC spin-current pulses. We calculate the optimal pulse times and current strengths for both AC and DC pulses as well as the optimal AC signal frequency, needed to minimize the Joule heat lost during the switching process. The results of this optimization are compared against numeric simulations. Finally, we show how this optimization leads to different dynamic regimes, where switching is optimized by either a purely AC or DC spin-current, or a combination AC/DC spin-current, depending on the anisotropy energies and the spin-current polarization.

  17. Experimental determination of equivalent circuit parameters for PM synchronous motors

    SciTech Connect (OSTI)

    Consoli, A.; Raciti, A. (Dept. Elettrico Elettronico e Sistemistico, Univ. di Catania, 95125 Catania (IT))

    1992-01-01

    The growing interest in energy savings, especially in industrial applications, has led to explore in more details the potential of unconventional excitation systems for electric machines. The wide spread use of Permanent Magnet materials in dc as well as in synchronous machines, to substitute the excitation circuit, is one of the ways followed to reach this objective. Significative work has been done in order to minimize the volume of the use permanent magnet material, to eliminate the motor behavior limitations due to the fixed value of excitation, to find the best geometries easy to manufacture and also reliable according to the dynamic stresses. A full procedure is presented in this paper to provide a straightforward tool useful for parameter determination of Permanent Magnet Synchronous Motors. Classical tests, that are well established to measure the parameters of synchronous machines with conventional field excitation, are reviewed to confirm or not their applicability. A novel test performed during particular transient conditions allows us to evaluate one of the concerned motor time constants. The motor behavior is simulated by means of a simulation language (ACSL) on a digital computer and several runs in different transient conditions are performed. Comparison of the simulated and experimental waveforms of speeds and currents shows good agreement and confirms the validity of the proposed procedure.

  18. AC susceptibility studies of high-[Tc] superconductors

    SciTech Connect (OSTI)

    Lee, Chang-Young.

    1993-01-01

    In this thesis, the authors studied physical properties of various high-T[sub c] superconductors by means of the ac susceptibility technique. They present the physics of ac susceptibility from first principles without relying on any specific models. From this, they can explain some fundamental but interesting features of experimental results such as symmetry properties of the ac susceptibility and its harmonics with respect to dc magnetic field. By measuring ac hysteresis they were able to obtain lower critical fields which were compared with some theoretical predictions. They found that the results were consistent with the BCS theory with modified gap parameter. By measuring ac hysteresis of granular samples at ultra low magnetic fields, they revealed the Meissner state and obtained Josephson lower critical fields, which was also found to be in consistence with the BCS theory. They studied the critical state models in detail and obtained some useful equations which were used in analyzing magnetic field dependence of ac susceptibility. By comparing the equations with experimental results, they were able to perform quantitative analysis of some important physical parameters such as critical current density. From numerical calculations of ac susceptibility with the parameter values obtained by this procedure, they confirmed good agreement of theory with experimental data. They incorporated the theory of flux creep into the equation governing the steady state flux motion, from which they were able to explain the shift of ac susceptibility with operating frequency toward high temperatures. Through this study, quantitative results on the activation energy were obtained.

  19. 3.3.3AC Sweep AC . AC

    E-Print Network [OSTI]

    ­. DC ­ AC ­) .( . ­ ,, '­Spice .Spice . : 0 0 E1 PWR(V(%IN+, %IN . )2.3( Etable " . . : 00 V1 0Vdc E2 Pwr(V(%IN+, %IN-),2) ETABLE TABLE = (5

  20. Seasonal change in the effect of field-aligned currents at synchronous orbit

    SciTech Connect (OSTI)

    McPherron, R.L.; Barfield, J.N.

    1980-12-01

    The expected signature of substorm field-aligned currents is described for synchronous satellites near 10 /sup 0/ magnetic latitudes. The main effect is a positive D perturbation premidnight and a negative D perturbation post-midnight. This behavior is illustrated for two substorms near the fall equinox. A second pair of substorms taken from winter solstice do not show the expected behavior. The absence of this effect in winter observations is verified statistically by superposed epoch analysis. A simple explanation of this behavior based on the geometry of the plane of magnetic symmetry is presented. During disturbed times at winter solstice a synchronous satellite nominally at 10 /sup 0/ magnetic latitude is effectively at the magnetic equator. This distortion of the magnetic equator must be considered in future models of the distrubed magnetospheric magnetic field.

  1. State observer for synchronous motors

    DOE Patents [OSTI]

    Lang, Jeffrey H. (Waltham, MA)

    1994-03-22

    A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

  2. Received 24 Oct 2014 | Accepted 16 Apr 2015 | Published 21 May 2015 Microscopic dynamics of synchronization

    E-Print Network [OSTI]

    Straube, Arthur V.

    of synchronization in driven colloids Michael P.N. Juniper1, Arthur V. Straube2, Rut Besseling3, Dirk G.A.L. Aarts1 for materials should be addressed to R.P.A.D. (email: roel.dullens@chem.ox.ac.uk). NATURE COMMUNICATIONS | 6. All rights reserved. #12;I n the natural world, little exists in a state of true equilibrium; in fact

  3. Advantages of enhanced synchronous motors in heating, refrigerating, and air conditioning applications

    SciTech Connect (OSTI)

    Morash, R.T. [Precise Power Corp., Bradenton, FL (United States)

    1998-12-31

    A new synchronous motor is a high-efficiency AC machine that has a low starting current. It may be used for conventional loads and also to start high inertia loads, delivering a constant torque during starting. Acceleration to synchronous speed can be allowed to take several minutes, if necessary, because the low starting current precludes excessive heating in the motor. Some of these motors are constructed with integral high inertia rotors that act as flywheels. These synchronous motors can ride through power sags and interruptions up to 30 seconds or more while still delivering useful load to pumps, fans, blowers, and compressors. The motors also restart instantly and resynchronize when utility power recovers. The motor can be useful in many heating, ventilating, and air-conditioning (HVAC) applications including those where machines and processes might otherwise be forced to shut down during momentary power interruptions.

  4. Objects and Synchronous Programming Charles ANDR1

    E-Print Network [OSTI]

    André, Charles

    gener- ated by a synchronous language compiler, the user must provide an execution machine [AND 93]. Our­ 1 ­ Objects and Synchronous Programming Charles ANDR�1 , Frédéric BOULANGER2 , Marie logical correctness, is the essence of the synchronous paradigm. This paper proposes to combine these two

  5. Synchronous Machine Modeling 1.0 Introduction

    E-Print Network [OSTI]

    McCalley, James D.

    windings There are 5 physical windings on a synchronous generator. · The 3 stator (phase) windings, denotedSynchronous Machine Modeling 1.0 Introduction Our motivation at this point is to put you in a position to understand synchronous machine modeling for power system dynamic analysis. If you take EE 457

  6. Targeting engineering synchronization in chaotic systems

    E-Print Network [OSTI]

    Sourav K. Bhowmick; Dibakar Ghosh

    2015-06-14

    A method of targeting engineering synchronization states in two identical and mismatch chaotic systems is explained in details. The method is proposed using linear feedback controller coupling for engineering synchronization such as mixed synchronization, linear and nonlinear generalized synchronization and targeting fixed point. The general form of coupling design to target any desire synchronization state under unidirectional coupling with the help of Lyapunov function stability theory is derived analytically. A scaling factor is introduced in the coupling definition to smooth control without any loss of synchrony. Numerical results are done on two mismatch Lorenz systems and two identical Sprott oscillators.

  7. High-speed synchronous reluctance machine with minimized rotor losses

    SciTech Connect (OSTI)

    Hofmann, H.; Sanders, S.R.

    2000-04-01

    This paper presents a refined design of a high-speed synchronous reluctance machine with minimized eddy-current losses in the rotor. Design criteria are the ability of the rotor to withstand high speeds, ability to operate in vacuum, negligible zero-torque spinning losses, high reliability, high efficiency, and low manufacturing cost. The rotor of the synchronous reluctance machine consists of bonded sections of ferromagnetic and non-magnetic steels. Finite-element code, incorporating rotor rotation, has been developed in MATLAB that calculates steady-state eddy currents (and losses) in the rotor. A stator iron and stator winding have been designed to minimize rotor losses, and two such prototype machines have been fabricated. Experimental results show an efficiency of 91% at a 10-kW 10,000-r/min operating point, and rotor losses less than 0.5% of input power.

  8. Synchronized monochromator and insertion device energy scans at SLS

    SciTech Connect (OSTI)

    Krempasky, J.; Flechsig, U.; Korhonen, T.; Zimoch, D.; Quitmann, Ch.; Nolting, F.

    2010-06-23

    Synchronous monochromator and insertion device energy scans were implemented at the Surfaces/Interfaces:Microscopy (SIM) beamline in order to provide the users fast X-ray magnetic dichroism studies (XMCD). A simple software control scheme is proposed based on a fast monochromator run-time energy readback which quickly updates the insertion device requested energy during an on-the-fly X-ray absorption scan (XAS). In this scheme the Plain Grating Monochromator (PGM) motion control, being much slower compared with the insertion device (APPLE-II type undulator), acts as a 'master' controlling the undulator 'slave' energy position. This master-slave software implementation exploits EPICS distributed device control over computer network and allows for a quasi-synchronous motion control combined with data acquisition needed for the XAS or XMCD experiment.

  9. Dynamic Jiles-Atherton Model for Determining the Magnetic Power Loss at High Frequency in Permanent Magnet Machines

    E-Print Network [OSTI]

    Du, Ruoyang; Robertson, Paul

    2014-12-18

    —Finite element methods (FEM), Magnetic hysteresis, Magnetic losses, Magnetization, Permanent magnet machines, Permanent magnet motors, Permanent magnet generators. I. INTRODUCTION HE magnetic power losses in ferromagnetic materials have been continuously... made to the original dynamic Jiles-Atherton model in order to make it work correctly for laminations in high frequency permanent magnet synchronous machines (PMSMs), such as BLDC motors. Since the working frequencies of modern BLDC motors...

  10. Tensor products of AC charges and AC Radon measures are not always AC charges

    E-Print Network [OSTI]

    Buczolich, Zoltán

    Tensor products of AC #3; charges and AC Radon measures are not always AC #3; charges Zolt#19;an and an absolutely continuous Radon measure #22; on R such that F #22; is not an AC#3; charge on R 2 . 1 Introduction In [1] the tensor problem was stated for the tensor product of AC #3; charges and the Lebesgue

  11. Digital-data receiver synchronization

    DOE Patents [OSTI]

    Smith, Stephen F.; Turner, Gary W.

    2005-08-02

    Digital-data receiver synchronization is provided with composite phase-frequency detectors, mutually cross-connected comparison feedback or both to provide robust reception of digital data signals. A single master clock can be used to provide frequency signals. Advantages can include fast lock-up time in moderately to severely noisy conditions, greater tolerance to noise and jitter when locked, and improved tolerance to clock asymmetries.

  12. Control of Two Permanent Magnet Machines Using a Five-Leg Inverter for Automotive Applications

    SciTech Connect (OSTI)

    Su, Gui-Jia [ORNL; Tang, Lixin [ORNL; Huang, Xianghui [GE Global Research

    2006-01-01

    This paper presents digital control schemes for control of two permanent magnet (PM) machines in an integrated traction and air-conditioning compressor drive system for automotive applications. The integrated drive system employs a five-leg inverter to power a three-phase traction PM motor and a two-phase compressor PM motor by tying the common terminal of the two-phase motor to the neutral point of the three-phase motor. Compared to a three-phase or a standalone two-phase inverter, it eliminates one phase leg and shares the control electronics between the two drives, thus significantly reducing the component count of the compressor drive. To demonstrate that the speed and torque of the two PM motors can be controlled independently, a control strategy was implemented in a digital signal processor, which includes a rotor flux field orientation based control (RFOC) for the three-phase motor, a similar RFOC and a position sensorless control in the brushless dc (BLDC) mode for the two-phase motor. Control implementation issues unique to a two-phase PM motor are also discussed. Test results with the three-phase motor running in the ac synchronous (ACS) mode while the two-phase motor either in the ACS or the BLDC mode are included to verify the independent speed and torque control capability of the integrated drive.

  13. ac-driven atomic quantum motor

    E-Print Network [OSTI]

    A. V. Ponomarev; S. Denisov; P. Hanggi

    2009-06-09

    We invent an ac-driven quantum motor consisting of two different, interacting ultracold atoms placed into a ring-shaped optical lattice and submerged in a pulsating magnetic field. While the first atom carries a current, the second one serves as a quantum starter. For fixed zero-momentum initial conditions the asymptotic carrier velocity converges to a unique non-zero value. We also demonstrate that this quantum motor performs work against a constant load.

  14. Synchronization of spin torque nano-oscillators through dipolar interactions

    SciTech Connect (OSTI)

    Chen, Hao-Hsuan, E-mail: d95222014@ntu.edu.tw; Wu, Jong-Ching, E-mail: phjcwu@cc.ncue.edu.tw; Horng, Lance [Department of Physics, National Changhua University of Education, Changhua 500, Taiwan (China); Lee, Ching-Ming [Graduate School of Materials Science, National Yunlin University of Science and Technology, Douliou, 64002, Taiwan (China); Chang, Ching-Ray, E-mail: crchang@phys.ntu.edu.tw; Chang, Jui-Hang [Department of Physics and Center for Quantum Sciences and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-04-07

    In an array of spin-torque nano-oscillators (STNOs) that combine a perpendicular polarized fixed layer with strong in-plane anisotropy in the free layers, magnetic dipolar interactions can effectively phase-lock the array, thus further enhancing the power of the output microwave signals. We perform a qualitative analysis of the synchronization of an array based on the Landau-Lifshitz-Gilbert equation, with a spin-transfer torque that assumes strong in-plane anisotropy. Finally, we present the numerical results for four coupled STNOs to provide further evidence for the proposed theory.

  15. Mechanisms Behind the Generalized Synchronization Conditions

    E-Print Network [OSTI]

    A. A. Koronovskii; O. I. Moskalenko; A. E. Hramov

    2006-02-25

    A universal mechanism underlying generalized synchronization conditions in unidirectionally coupled stochastic oscillators is considered. The consideration is carried out in the framework of a modified system with additional dissipation. The approach developed is illustrated with model examples. The conclusion is reached that two types of the behavior of nonlinear dynamic systems known as generalized synchronization and noise-induced synchronization, which are viewed as different phenomena, actually represent a unique type of the synchronous behavior of stochastic oscillators and are caused by the same mechanism.

  16. Evolving Globally Synchronized Cellular Automata Rajarshi Das

    E-Print Network [OSTI]

    Mitchell, Melanie

    embedded particles. The particles, typically phase defects between synchronous regions, are designed the developmental and reproductive stages of the Dictyostelium slime mold (Devreotes, 1989), the morphogenesis

  17. Noise-Induced Transitions in Optomechanical Synchronization

    E-Print Network [OSTI]

    Talitha Weiss; Andreas Kronwald; Florian Marquardt

    2015-07-22

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

  18. Magnetic Reconnection 6.1 Introduction

    E-Print Network [OSTI]

    Priest, Eric

    . The main effects of magnetic reconnection are often: (i) to convert some of the magnetic energy into heat elements (AB to AC). 1 #12;2 Magnetic Reconnection fast particles and heat, which are directed mainly alongAi/ is the magnetic Reynolds number based on the length L of the sheet. This rate is a small fraction of the Alfv

  19. Tensor products of AC* charges and AC Radon measures are not always AC* charges

    E-Print Network [OSTI]

    Buczolich, Zoltán

    Tensor products of AC* charges and AC Radon measures are not always AC* charges] the tensor problem was stated for the tensor product of AC* charges and the Lebesgue measure. Later W: non-absolute integrals, variational measure, tensor product. 1

  20. Binarization of Synchronous Context-Free Grammars

    E-Print Network [OSTI]

    Binarization of Synchronous Context-Free Grammars Liang Huang USC/Information Science Institute Hao Systems based on synchronous grammars and tree transducers promise to improve the quality of statistical machine translation output, but are often very computationally intensive. The complexity is exponential

  1. Scalable Synchronous Queues William N. Scherer III

    E-Print Network [OSTI]

    Scott, Michael L.

    Scalable Synchronous Queues William N. Scherer III University of Rochester scherer@cs.rochester.edu Abstract We present two new nonblocking and contention-free implementa- tions of synchronous queues. We present performance results on 16-processor SPARC and 4- processor Opteron machines. We compare

  2. Isochronal synchronization of delay-coupled systems

    E-Print Network [OSTI]

    Ira B. Schwartz; Leah B. Shaw

    2007-02-25

    We consider small network models for mutually delay-coupled systems which typically do not exhibit stable isochronally synchronized solutions. We show that for certain coupling architectures which involve delayed self feedback to the nodes, the oscillators become isochronally synchronized. Applications are shown for both incoherent pump coupled lasers and spatio-temporal coupled fiber ring lasers.

  3. Design of coupling for synchronization in time-delayed systems

    E-Print Network [OSTI]

    Dibakar Ghosh; Ioan Grosu; Syamal Kumar Dana

    2012-07-03

    We report a design of delay coupling for targeting desired synchronization in delay dynamical systems. We target synchronization, antisynchronization, lag-, antilag- synchronization, amplitude death (or oscillation death) and generalized synchronization in mismatched oscillators. A scaling of the size of an attractor is made possible in different synchronization regimes. We realize a type of mixed synchronization where synchronization, antisynchronization coexist in different pairs of state variables of the coupled system. We establish the stability condition of synchronization using the Krasovskii-Lyapunov function theory and the Hurwitz matrix criterion. We present numerical examples using the Mackey-Glass system and a delay R\\"{o}ssler system.

  4. On synchronous robotic networks - Part I: Models, tasks, and complexity

    E-Print Network [OSTI]

    Frazzoli, Emilio; Bullo, Francesco; Cortes, Jorge; Martinez, Sonia

    2007-01-01

    E. Frazzoli, “On synchronous robotic networks Part II: Timeto control design for mobile robotic networks. Application2007 On Synchronous Robotic Networks—Part I: Models, Tasks,

  5. Synchronous Behavior of Two Coupled Biological Neurons

    SciTech Connect (OSTI)

    Elson, R.C.; Selverston, A.I.; Elson, R.C.; Selverston, A.I.; Huerta, R.; Rulkov, N.F.; Rabinovich, M.I.; Abarbanel, H.D.; Selverston, A.I.; Huerta, R.; Abarbanel, H.D.

    1998-12-01

    We report experimental studies of synchronization phenomena in a pair of biological neurons that interact through naturally occurring, electrical coupling. When these neurons generate irregular bursts of spikes, the natural coupling synchronizes slow oscillations of membrane potential, but not the fast spikes. By adding artificial electrical coupling we studied transitions between synchrony and asynchrony in both slow oscillations and fast spikes. We discuss the dynamics of bursting and synchronization in living neurons with distributed functional morphology. {copyright} {ital 1998} {ital The American Physical Society}

  6. Synchronization System for Next Generation Light Sources

    SciTech Connect (OSTI)

    Zavriyev, Anton

    2014-03-27

    An alternative synchronization technique – one that would allow explicit control of the pulse train including its repetition rate and delay is clearly desired. We propose such a scheme. Our method is based on optical interferometry and permits synchronization of the pulse trains generated by two independent mode-locked lasers. As the next generation x-ray sources will be driven by a clock signal derived from a mode-locked optical source, our technique will provide a way to synchronize x-ray probe with the optical pump pulses.

  7. 734 IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 39, NO. 3, MAY/JUNE 2003 Modeling of Iron Losses of Permanent-Magnet

    E-Print Network [OSTI]

    Mi, Chunting "Chris"

    currents, hysteresis, iron losses, permanent magnets (PMs), permanent-magnet (PM) machines, synchronous Losses of Permanent-Magnet Synchronous Motors Chunting Mi, Member, IEEE, Gordon R. Slemon, Life Fellow and the reduction of stator loss from operation near unity power factor. In PM machines, iron losses form

  8. Synthesis for Logical Initializability of Synchronous Finite State Machines \\Lambda

    E-Print Network [OSTI]

    Synthesis for Logical Initializability of Synchronous Finite State Machines \\Lambda Montek Singh is introduced for the synthesis for logical initializability of synchronous state machines. The goal that initializes the state machine is called its synchronizing sequence or initialization sequence. A synchronizing

  9. IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 14, NO. 1, MARCH 2004 69 AC Losses in Type-II Superconductors Induced by

    E-Print Network [OSTI]

    Prigozhin, Leonid

    -II superconductors in power transmission lines, current leads, fault current limiters, magnetic shields, bearings losses in flywheels, electric motors, magnetic shields, etc. Index Terms--AC losses, asymptotic solution

  10. A microfluidic “baby machine” for cell synchronization

    E-Print Network [OSTI]

    Shaw, Josephine

    Common techniques used to synchronize eukaryotic cells in the cell cycle often impose metabolic stress on the cells or physically select for size rather than age. To address these deficiencies, a minimally perturbing method ...

  11. Clock synchronization for mobile ad hoc networks 

    E-Print Network [OSTI]

    Chandra, Rajan

    2013-02-22

    synchronization uses MANet specific communication primitives with Minimum Connected Dominating Set (MCDS) approximation algorithms. This involves using a subset of nodes in the network to broadcast clock information to neighboring nodes. Several MCDS approximation...

  12. Protection and Synchronization in Actor Systems

    E-Print Network [OSTI]

    Hewitt, Carl

    This paper presents a unified method [called ENCASING] for dealing with the closely related issues of synchronization and protection in actor systems [Hewitt et al. 1973a, 1973b, 1974a; Greif and Hewitt 1975]. Actors are ...

  13. Improved Gene Targeting through Cell Cycle Synchronization

    E-Print Network [OSTI]

    Tsakraklides, Vasiliki

    Gene targeting is a challenge in organisms where non-homologous end-joining is the predominant form of recombination. We show that cell division cycle synchronization can be applied to significantly increase the rate of ...

  14. Opportunistic, collaborative and synchronized, proximal device ecology

    E-Print Network [OSTI]

    Toledano, Eyal

    2013-01-01

    CoSync is an on-device software framework for coordinating proximal consumer electronic devices in order to create a synchronized, opportunistic and collaborative device ecology. The CoSync device ecology combines multiple ...

  15. Robust Clock Synchronization in Wireless Sensor Networks 

    E-Print Network [OSTI]

    Saibua, Sawin

    2010-10-12

    Clock synchronization between any two nodes in a Wireless Sensor Network (WSNs) is generally accomplished through exchanging messages and adjusting clock offset and skew parameters of each node’s clock. To cope with unknown network message delays...

  16. Adaptive synchronization of coupled chaotic oscillators

    E-Print Network [OSTI]

    Bhargava Ravoori; Adam B. Cohen; Anurag V. Setty; Francesco Sorrentino; Thomas E. Murphy; Edward Ott; Rajarshi Roy

    2009-10-05

    We experimentally demonstrate and numerically simulate a new adaptive method to maintain synchronization between coupled nonlinear chaotic oscillators, when the coupling between the systems is unknown and time-varying (e.g., due to environmental parameter drift). The technique is applied to optoelectronic feedback loops exhibiting high dimensional chaotic dynamics. In addition to keeping the two systems isochronally synchronized in the presence of a priori unknown time-varying coupling strength, the technique provides an estimate of the time-varying coupling.

  17. Synchronization in a semiclassical Kuramoto model

    E-Print Network [OSTI]

    Ignacio Hermoso de Mendoza; Leonardo A. Pachón; Jesús Gómez-Gardeñes; David Zueco

    2014-11-10

    Synchronization is a ubiquitous phenomenon occurring in social, biological, and technological systems when the internal rhythms of their constituents are adapted to be in unison as a result of their coupling. This natural tendency towards dynamical consensus has spurred a large body of theoretical and experimental research in recent decades. The Kuramoto model constitutes the most studied and paradigmatic framework in which to study synchronization. In particular, it shows how synchronization appears as a phase transition from a dynamically disordered state at some critical value for the coupling strength between the interacting units. The critical properties of the synchronization transition of this model have been widely studied and many variants of its formulations have been considered to address different physical realizations. However, the Kuramoto model has been studied only within the domain of classical dynamics, thus neglecting its applications for the study of quantum synchronization phenomena. Based on a system-bath approach and within the Feynman path-integral formalism, we derive equations for the Kuramoto model by taking into account the first quantum fluctuations. We also analyze its critical properties, the main result being the derivation of the value for the synchronization onset. This critical coupling increases its value as quantumness increases, as a consequence of the possibility of tunneling that quantum fluctuations provide.

  18. Analysis of electrical signatures in synchronous generators characterized by bearing faults 

    E-Print Network [OSTI]

    Choi, Jae-Won

    2009-05-15

    mechanical load and speed variations in the driven systems or electric machine itself and convert them via back-emf into stator signal variations. The stator signals are collected in a non- intrusive manner and then processed to detect and diagnose mechanical...) around the rotor poles. Due to the MMF, the field magnetic flux crosses the air gap and enters the armature winding. When the rotor rotates at synchronous speed, the flux linkage with the stator winding induces the electromotive force (EMF...

  19. Real-Time Capable Methods to Determine the Magnet Temperature of Permanent Magnet

    E-Print Network [OSTI]

    Noé, Reinhold

    ) is widely spread in industrial applications. Due to the development of high energy permanent magnet Motors -- A Review Oliver Wallscheid, Tobias Huber, Wilhelm Peters, Joachim B¨ocker Power Electronics}@lea.upb.de Abstract--The permanent magnet synchronous motor (PMSM) is widely used in highly utilised automotive

  20. Permanent magnet assisted synchronous reluctance motor, design and performance improvement 

    E-Print Network [OSTI]

    Niazi, Peyman

    2006-04-12

    . current........................................................................75 2- 33 Saturation effect due to the PM of the rotor.........................................................75 2- 34 Line-to-line back-EMF in PMa...-SynRM. .............................................................76 2- 35 Torque-angle curves of the PMa-SynRM and SynRM. .......................................77 2- 36 Stator and rotor laminations of the proposed PMa-SynRM.................................78 2- 37 Actual back-EMF line voltage at 1800...

  1. The Scheme of Beam Synchronization in MEIC

    SciTech Connect (OSTI)

    Zhang, Yuhong; Derbenev, Yaroslav S.; Hutton, Andrew M.

    2013-06-01

    Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme.

  2. Synchronous Characterization of Semiconductor Microcavity Laser Beam

    E-Print Network [OSTI]

    Wang, Tao

    2015-01-01

    We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show that the laser frequency is an inhomogeneous distribution below threshold, but that it becomes homogeneous across the fundamental Gaussian mode above threshold. The beam's tails deviations from the Gaussian shape, however, are accompanied by sizeable fluctuations in the laser wavelength, possibly deriving from manufacturing details and from the influence of spontaneous emission in the very low intensity wings. In addition to the synchronous spatial characterization, a temporal analysis at any given point in the beam cross-section is carried out. Using this method, the beam homogeneity and spatial shape, energy density, energy center and the defects-related spectrum can also be extracted from these high-resolution pictures.

  3. Anomalous synchronization threshold in coupled logistic maps

    E-Print Network [OSTI]

    C. Anteneodo; A. M. Batista; R. L. Viana

    2005-04-05

    We consider regular lattices of coupled chaotic maps. Depending on lattice size, there may exist a window in parameter space where complete synchronization is eventually attained after a transient regime. Close outside this window, an intermittent transition to synchronization occurs. While asymptotic transversal Lyapunov exponents allow to determine the synchronization threshold, the distribution of finite-time Lyapunov exponents, in the vicinity of the critical frontier, is expected to provide relevant information on phenomena such as intermittency. In this work we scrutinize the distribution of finite-time exponents when the local dynamics is ruled by the logistic map $x \\mapsto 4x(1-x)$. We obtain a theoretical estimate for the distribution of finite-time exponents, that is markedly non-Gaussian. The existence of correlations, that spoil the central limit approximation, is shown to modify the typical intermittent bursting behavior. The present scenario could apply to a wider class of systems with different local dynamics and coupling schemes.

  4. Efficient dynamic synchronous machine simulation with harmonics

    SciTech Connect (OSTI)

    Haskew, T.A.; Stern, H.P.; Chen, Z. [Univ. of Alabama, Tuscaloosa, AL (United States). Dept. of Electrical Engineering] [Univ. of Alabama, Tuscaloosa, AL (United States). Dept. of Electrical Engineering

    1996-06-01

    Within this paper, an efficient procedure for the dynamic simulation of faulted synchronous machines operating in the presence of harmonics is presented. The algorithm employs steady-state frequency domain techniques for simulation of the transmission system sequence networks and time domain methods for the synchronous machines represented in the odq frame of reference. The procedure affords greater accuracy than conventional fault analysis techniques based strictly on steady-state methods, yet requires far less computational time than full system dynamic simulations such as those using the EMTP.

  5. A reply to "Quantum Clock Synchronization"

    E-Print Network [OSTI]

    Eric Burt; Chris Ekstrom; Tom Swanson

    2000-07-11

    Recently a protocol for Quantum Clock Synchronization (QCS) of remote clocks using quantum entanglement was proposed by Jozsa et al. This method has the goal of eliminating the random noise present in classical synchronization techniques. However, as stated QCS depends on the two members of each entangled pair undergoing the same unitary evolution even while being transported to different locations. This is essentially equivalent to a perfect Eddington Slow Clock Transfer protocol and thus, not an improvement over classical techniques. We will discuss this and suggest ways in which QCS may still be used.

  6. Synchronous Machine Modeling Notes2 1.0 Inductances

    E-Print Network [OSTI]

    McCalley, James D.

    Synchronous Machine Modeling ­ Notes2 1.0 Inductances Recall the relation between flux linkages. Rather, for each coil and coil pair in the synchronous machine, we are going to see if any of the terms

  7. Modular Composition of Synchronous Programs: Applications to Traffic Signal Control

    E-Print Network [OSTI]

    Zennaro, Marco; Sengupta, Raja

    2006-01-01

    Synchronous Programs Figure 9: The model used to estimate the overhead 512 Mb ram machines.machines. Hence, we argue that we can distribute a Simulink-like synchronous

  8. Self-stabilizing clock phase synchronization in a distributed ring 

    E-Print Network [OSTI]

    Pancholi, Alok

    1994-01-01

    case synchronization time of the algortihm is [ ] pulses, where n is the size of the ring. Finally, this tecnique is extended to achieve synchronization of 2i-phase clocks or events....

  9. Call Description cread highspeed, synchronous read from a CFS file

    E-Print Network [OSTI]

    Torczon, Virginia

    Call Description cread high­speed, synchronous read from a CFS file cwrite high­speed, synchronous write to a CFS file gilow global MIN operation used for integer scalars gopf make a global operation

  10. Complete chaotic synchronization in mutually coupled time-delay systems

    E-Print Network [OSTI]

    Alexandra S. Landsman; Ira B. Schwartz

    2007-10-25

    Complete chaotic synchronization of end lasers has been observed in a line of mutually coupled, time-delayed system of three lasers, with no direct communication between the end lasers. The present paper uses ideas from generalized synchronization to explain the complete synchronization in the presence of long coupling delays, applied to a model of mutually coupled semiconductor lasers in a line. These ideas significantly simplify the analysis by casting the stability in terms of the local dynamics of each laser. The variational equations near the synchronization manifold are analyzed, and used to derive the synchronization condition that is a function of the parameters. The results explain and predict the dependence of synchronization on various parameters, such as time-delays, strength of coupling and dissipation. The ideas can be applied to understand complete synchronization in other chaotic systems with coupling delays and no direct communication between synchronized sub-systems.

  11. Superconducting shielded core reactor with reduced AC losses

    DOE Patents [OSTI]

    Cha, Yung S.; Hull, John R.

    2006-04-04

    A superconducting shielded core reactor (SSCR) operates as a passive device for limiting excessive AC current in a circuit operating at a high power level under a fault condition such as shorting. The SSCR includes a ferromagnetic core which may be either closed or open (with an air gap) and extends into and through a superconducting tube or superconducting rings arranged in a stacked array. First and second series connected copper coils each disposed about a portion of the iron core are connected to the circuit to be protected and are respectively wound inside and outside of the superconducting tube or rings. A large impedance is inserted into the circuit by the core when the shielding capability of the superconducting arrangement is exceeded by the applied magnetic field generated by the two coils under a fault condition to limit the AC current in the circuit. The proposed SSCR also affords reduced AC loss compared to conventional SSCRs under continuous normal operation.

  12. Paradigmes objets et synchrones dans les systmes temps-rel

    E-Print Network [OSTI]

    André, Charles

    les objets synchrones de F. Boulanger et les machines d'exécution pour langages synchrones. Les SyncParadigmes objets et synchrones dans les systèmes temps-réel Charles ANDR� Laboratoire I3S'équipe SPORTS (Synchronous Programming Of Real-Time Systems) s'intéresse à la conception de systèmes réactifs

  13. Synthesis for Logical Initializability of Synchronous Finite State Machines

    E-Print Network [OSTI]

    Synthesis for Logical Initializability of Synchronous Finite State Machines Montek Singh Steven M for the synthesis for logical initializability of synchronous state machines. The goal is to synthesize a gate to physically reset machines if they get out of synchronism. Furthermore, a form of initializability called

  14. Software Synthesis from Synchronous Specifications Using Logic Simulation Techniques

    E-Print Network [OSTI]

    Brayton, Robert K.

    a synchronous state machine specification for em- bedded control systems. The framework is generic enoughSoftware Synthesis from Synchronous Specifications Using Logic Simulation Techniques Yunjian Jiang variables. This model has been studied for system design and verification. High-level synchronous languages

  15. Intelligent Predictive Control Methods for Synchronous Power System

    E-Print Network [OSTI]

    Rizvi, Syed Z.

    @kfupm.edu.sa Abstract--In this paper, an intelligent Model Predictive Con- troller (MPC) for a Synchronous Power Machine of a Single synchronous Machine on Infinite Bus (SMIB) has been one of the most important problems for powerIntelligent Predictive Control Methods for Synchronous Power System Muhammad S. Yousuf Electrical

  16. EXECUTION MACHINE FOR SYNCHRONOUS LANGUAGES Charles ANDR Hdi BOUFAED

    E-Print Network [OSTI]

    André, Charles

    EXECUTION MACHINE FOR SYNCHRONOUS LANGUAGES Charles ANDR� Hédi BOUFAÏED Laboratoire I3S, Université on a the synchronous paradigm, and explains the role and the architecture of the execution machine. Keywords: synchronous programming, execution machine, control, implementation. NOMENCLATURE We use Courier as the font

  17. Regulation and controlled synchronization for complex dynamical systems

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Regulation and controlled synchronization for complex dynamical systems H.J.C. Huijberts #3; H of controlled synchronization as a regulator problem. In controlled synchronization one is given autonomous of the problem where the standard solvability assumptions for the regulator problem are not met turn out to have

  18. Separating Synchronization Concerns with Frameworks and Generative Programming

    E-Print Network [OSTI]

    Stirewalt, Kurt

    Separating Synchronization Concerns with Frameworks and Generative Programming Scott D. Fleming, R USA 48824 {sdf,stire,ldillon,bss}@cse.msu.edu Abstract Thread synchronization in object-oriented systems is difficult to implement, in part, because traditional synchronization mechanisms are low level

  19. Identification and Tracking of Parameters for a Large Synchronous Generator

    E-Print Network [OSTI]

    Identification and Tracking of Parameters for a Large Synchronous Generator Final Project Report and Tracking of Parameters for a Large Synchronous Generator Final Project Report G. T. Heydt, Project Leader for a Large Synchronous Generator 1. Introduction The power system state estimation problem ha

  20. INNOVATIVE CONCEPTS FOR ON-LINE SYNCHRONOUS GENERATOR PARAMETER ESTIMATION

    E-Print Network [OSTI]

    INNOVATIVE CONCEPTS FOR ON-LINE SYNCHRONOUS GENERATOR PARAMETER ESTIMATION by Elias Kyriakides FOR ON-LINE SYNCHRONOUS GENERATOR PARAMETER ESTIMATION by Elias Kyriakides has been approved December ABSTRACT A method to identify synchronous generator parameters from on-line measurements is presented

  1. Joint synchronization of clock phase offset, skew and drift in reference broadcast synchronization (RBS) protocol 

    E-Print Network [OSTI]

    Sari, Ilkay

    2009-06-02

    Time-synchronization in wireless ad-hoc sensor networks is a crucial piece of infrastructure. Thus, it is a fundamental design problem to have a good clock syn- chronization amongst the nodes of wireless ad-hoc sensor ...

  2. Synchronized bursts following instability of synchronous spiking in chaotic neuronal networks

    E-Print Network [OSTI]

    Mikhail V. Ivanchenko; Grigory V. Osipov; Vladimir D. Shalfeev; Jurgen Kurths

    2006-01-11

    We report on the origin of synchronized bursting dynamics in various networks of neural spiking oscillators, when a certain threshold in coupling strength is exceeded. These ensembles synchronize at relatively low coupling strength and lose synchronization at stronger coupling via spatio-temporal intermittency. The latter transition triggers multiple-timescale dynamics, which results in synchronized bursting with a fractal-like spatio-temporal pattern of spiking. Implementation of an appropriate technique of separating oscillations on different time-scales allows for quantitative analysis of this phenomenon. We show, that this phenomenon is generic for various network topologies from regular to small-world and scale-free ones and for different types of coupling.

  3. Iron loss calculation for synchronous reluctance machines

    SciTech Connect (OSTI)

    Leonardi, F.; Matsuo, T.; Lipo, T.A. [Univ. of Wisconsin, Madison, WI (United States)

    1995-12-31

    A numerical method for iron loss calculation is presented in this paper. The method is suitable for any synchronous and most dc machines, especially if the current waveforms are known a priori . This technique will be principally useful for high speed machines and in particular for the synchronous reluctance machines and in particular for the synchronous reluctance machine, where the iron losses are often an important issue. The calculation is based on Finite Element Analysis, which provides the flux density waveforms in the iron, and on the Fourier Analysis of these waveforms. Several Finite Element Simulations are necessary to obtain the induced voltage versus time waveforms. To reduce the post-processing time the majority of the elements of the model are grouped together to create super elements. Also the periodicity of the motor can be used to reduce the number of required simulations. The method is applied to the calculation of the iron losses of a synchronous reluctance generator, and a number of interesting results are discussed in the paper.

  4. Simulation of Synchronous Machines This chapter covers

    E-Print Network [OSTI]

    McCalley, James D.

    1 Simulation of Synchronous Machines This chapter covers: (A) Sections 5.25.7: Determination of initial conditions (B) Section 5.8: Determination of machine parameters from manufacturers' data.3: Machine connected to an infinite bus through a line · Section 5.4: Machine connected

  5. Asynchronous vs Synchronous Input-Queued Switches

    E-Print Network [OSTI]

    1 Asynchronous vs Synchronous Input-Queued Switches Andrea Bianco, Davide Cuda, Paolo Giaccone Dipartimento di Elettronica, Politecnico di Torino (Italy) 3 Abstract--Input-queued (IQ) switches are one of the reference archi- tectures for the design of high-speed packet switches. Classical results in this field

  6. Asynchronous vs Synchronous Input-Queued Switches

    E-Print Network [OSTI]

    Asynchronous vs Synchronous Input-Queued Switches Andrea Bianco, Davide Cuda, Paolo Giaccone, Fabio Neri Dipartimento di Elettronica, Politecnico di Torino (Italy) Abstract--Input-queued (IQ) switches are one of the reference architectures for the design of high-speed packet switches. Clas- sical results

  7. Generation and Synchronous Tree-Adjoining Grammars

    E-Print Network [OSTI]

    Generation and Synchronous Tree-Adjoining Grammars Stuart M. Shieber Aiken Computation Laboratory) have been proposed as a formalism for generation based on the intuition that the extended domain as an aid to generation from semantic representations. We demonstrate that this intuition can be made

  8. Generation and Synchronous TreeAdjoining Grammars

    E-Print Network [OSTI]

    Shieber, Stuart

    Generation and Synchronous Tree­Adjoining Grammars Stuart M. Shieber Yves Schabes Aiken Computation) have been proposed as a formal­ ism for generation based on the intuition that the extended domain serving as an aid to generation from semantic representations. We demonstrate that this intuition can

  9. Synchronous Machines 1.0 Introduction

    E-Print Network [OSTI]

    McCalley, James D.

    % of the MW in most power systems; · Provide frequency regulation and load following; · Are the main source of energy (steam, water, wind) into mechanical energy, as illustrated in Fig. 1 [1]. Fig. 1 [1] PDF created the induced voltage in the armature (stator) windings is synchronized with (has same frequency as) the network

  10. Synchronization and entrainment of coupled circadian oscillators

    E-Print Network [OSTI]

    Toral, Raúl

    Synchronization and entrainment of coupled circadian oscillators N. Komin, A. C. Murza, E. Herna- ciently entrained by the 24 h light­dark cycle. Most of the studies carried out so far emphasize oscillators being more entrainable by the external forcing than the self-oscillating neurons with different

  11. The Wireless Synchronization Problem Shlomi Dolev

    E-Print Network [OSTI]

    Lynch, Nancy

    The Wireless Synchronization Problem Shlomi Dolev Ben-Gurion University Beer-Sheva, Israel dolev Newport MIT CSAIL Cambridge, MA, USA cnewport@csail.mit.edu ABSTRACT In this paper, we study the wireless-1-60558-396-9/09/08 ...$10.00. Categories and Subject Descriptors C.2.1 [Network Architecture and Design]: Wireless Net

  12. ACS Web Editions/ACS Legacy Archives Multiple Site/Consortium Sales Agreement Page 1 of 2

    E-Print Network [OSTI]

    Kisiel, Zbigniew

    ACS Web Editions/ACS Legacy Archives Multiple Site/Consortium Sales Agreement Page 1 of 2 I. Czasopisma ACS Web Edition 1. Accounts of Chemical Research 2. ACS Applied Materials & Interfaces 3. ACS Letters http://pubs.acs.org/journal/jpclcd #12;ACS Web Editions/ACS Legacy Archives Multiple Site

  13. Observation of multi-scale oscillation of laminar lifted flames with low-frequency AC electric fields

    SciTech Connect (OSTI)

    Ryu, S.K.; Kim, Y.K.; Kim, M.K.; Won, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Chung, S.H. [Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

    2010-01-15

    The oscillation behavior of laminar lifted flames under the influence of low-frequency AC has been investigated experimentally in coflow jets. Various oscillation modes were existed depending on jet velocity and the voltage and frequency of AC, especially when the AC frequency was typically smaller than 30 Hz. Three different oscillation modes were observed: (1) large-scale oscillation with the oscillation frequency of about 0.1 Hz, which was independent of the applied AC frequency, (2) small-scale oscillation synchronized to the applied AC frequency, and (3) doubly-periodic oscillation with small-scale oscillation embedded in large-scale oscillation. As the AC frequency decreased from 30 Hz, the oscillation modes were in the order of the large-scale oscillation, doubly-periodic oscillation, and small-scale oscillation. The onset of the oscillation for the AC frequency smaller than 30 Hz was in close agreement with the delay time scale for the ionic wind effect to occur, that is, the collision response time. Frequency-doubling behavior for the small-scale oscillation has also been observed. Possible mechanisms for the large-scale oscillation and the frequency-doubling behavior have been discussed, although the detailed understanding of the underlying mechanisms will be a future study. (author)

  14. System and method for time synchronization in a wireless network

    DOE Patents [OSTI]

    Gonia, Patrick S. (Maplewood, MN); Kolavennu, Soumitri N. (Blaine, MN); Mahasenan, Arun V. (Kerala, IN); Budampati, Ramakrishna S. (Maple Grove, MN)

    2010-03-30

    A system includes multiple wireless nodes forming a cluster in a wireless network, where each wireless node is configured to communicate and exchange data wirelessly based on a clock. One of the wireless nodes is configured to operate as a cluster master. Each of the other wireless nodes is configured to (i) receive time synchronization information from a parent node, (ii) adjust its clock based on the received time synchronization information, and (iii) broadcast time synchronization information based on the time synchronization information received by that wireless node. The time synchronization information received by each of the other wireless nodes is based on time synchronization information provided by the cluster master so that the other wireless nodes substantially synchronize their clocks with the clock of the cluster master.

  15. Digital ac monitor

    DOE Patents [OSTI]

    Hart, George W. (Natick, MA); Kern, Jr., Edward C. (Lincoln, MA)

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer.

  16. Digital ac monitor

    DOE Patents [OSTI]

    Hart, G.W.; Kern, E.C. Jr.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer. 24 figs.

  17. Synchronization in networks of spatially extended systems

    SciTech Connect (OSTI)

    Filatova, Anastasiya E.; Hramov, Alexander E.; Koronovskii, Alexey A.; Boccaletti, Stefano

    2008-06-15

    Synchronization processes in networks of spatially extended dynamical systems are analytically and numerically studied. We focus on the relevant case of networks whose elements (or nodes) are spatially extended dynamical systems, with the nodes being connected with each other by scalar signals. The stability of the synchronous spatio-temporal state for a generic network is analytically assessed by means of an extension of the master stability function approach. We find an excellent agreement between the theoretical predictions and the data obtained by means of numerical calculations. The efficiency and reliability of this method is illustrated numerically with networks of beam-plasma chaotic systems (Pierce diodes). We discuss also how the revealed regularities are expected to take place in other relevant physical and biological circumstances.

  18. Synchronous and Cogged Fan Belt Performance Assessment

    SciTech Connect (OSTI)

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  19. Synchronous behavior of two coupled electronic neurons

    SciTech Connect (OSTI)

    Pinto, R. D.; Varona, P.; GNB, Departamento Ingenieria Informatica, Universidad Autonoma de Madrid, 28049 Madrid, ; Volkovskii, A. R.; Szuecs, A.; Abarbanel, Henry D. I.; Department of Physics and Marine Physical Laboratory, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0402 ; Rabinovich, M. I.

    2000-08-01

    We report on experimental studies of synchronization phenomena in a pair of analog electronic neurons (ENs). The ENs were designed to reproduce the observed membrane voltage oscillations of isolated biological neurons from the stomatogastric ganglion of the California spiny lobster Panulirus interruptus. The ENs are simple analog circuits which integrate four-dimensional differential equations representing fast and slow subcellular mechanisms that produce the characteristic regular/chaotic spiking-bursting behavior of these cells. In this paper we study their dynamical behavior as we couple them in the same configurations as we have done for their counterpart biological neurons. The interconnections we use for these neural oscillators are both direct electrical connections and excitatory and inhibitory chemical connections: each realized by analog circuitry and suggested by biological examples. We provide here quantitative evidence that the ENs and the biological neurons behave similarly when coupled in the same manner. They each display well defined bifurcations in their mutual synchronization and regularization. We report briefly on an experiment on coupled biological neurons and four-dimensional ENs, which provides further ground for testing the validity of our numerical and electronic models of individual neural behavior. Our experiments as a whole present interesting new examples of regularization and synchronization in coupled nonlinear oscillators. (c) 2000 The American Physical Society.

  20. Bipolar pulse field for magnetic refrigeration

    DOE Patents [OSTI]

    Lubell, M.S.

    1994-10-25

    A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies. 2 figs.

  1. Abstract--This paper investigates the effect of STATCOM in stabilising multi-mode torsional oscillations of sub-synchronous

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    Magnetic Energy Storage Unit [25-27] to improve power system transient stability. Flexible AC Transmission which the power is transmitted increases. The increase of power transfer capability of long transmission. If the stability is lost, network collapse may occur with annihilating economical losses and severe power grid

  2. Snowflake-type network to minimize synchronization cost

    E-Print Network [OSTI]

    Watanabe, Takamitsu

    2011-01-01

    For stable electrical supply, voltage frequency of power plants should be synchronized. Nevertheless, the frequency synchronization causes power loss due to difference of voltage phases among power plants. The cost for synchronization should be reduced for efficient power grids, so-called smart grid, but little is known about what network topology has a small amount of the synchronization cost. In the present study, we newly define the synchronization cost, and investigate the optimal network structure with the minimum synchronization cost through rewiring-based optimization. By approximating a power grid with the Kuramoto model, we demonstrate that the cost is minimized in a snowflake-type network topology, which comprises the densely-connected center nodes and peripheral nodes connecting with the center module. We also show that the network topology is characterized by its bimodal degree distribution, which is quantified by Wolfson's polarization index. Furthermore, we provide analytical explanation on why ...

  3. Generalized chaotic synchronization in coupled Ginzburg-Landau equations

    SciTech Connect (OSTI)

    Koronovskii, A. A., E-mail: alkor@nonlin.sgu.ru; Popov, P. V., E-mail: popovpv@nonlin.sgu.ru; Hramov, A. E. [Saratov State University (Russian Federation)], E-mail: aeh@nonlin.sgu.ru

    2006-10-15

    Generalized synchronization is analyzed in unidirectionally coupled oscillatory systems exhibiting spatiotemporal chaotic behavior described by Ginzburg-Landau equations. Several types of coupling between the systems are analyzed. The largest spatial Lyapunov exponent is proposed as a new characteristic of the state of a distributed system, and its calculation is described for a distributed oscillatory system. Partial generalized synchronization is introduced as a new type of chaotic synchronization in spatially nonuniform distributed systems. The physical mechanisms responsible for the onset of generalized chaotic synchronization in spatially distributed oscillatory systems are elucidated. It is shown that the onset of generalized chaotic synchronization is described by a modified Ginzburg-Landau equation with additional dissipation irrespective of the type of coupling. The effect of noise on the onset of a generalized synchronization regime in coupled distributed systems is analyzed.

  4. Efficient synchronization of structurally adaptive coupled Hindmarsh-Rose neurons

    E-Print Network [OSTI]

    A. Moujahid; A. d'Anjou; F. J. Torrealdea

    2012-03-05

    The use of spikes to carry information between brain areas implies complete or partial synchronization of the neurons involved. The degree of synchronization reached by two coupled systems and the energy cost of maintaining their synchronized behaviour is highly dependent on the nature of the systems. For non-identical systems the maintenance of a synchronized regime is energetically a costly process. In this work, we study conditions under which two non-identical electrically coupled neurons can reach an efficient regime of synchronization at low energy cost. We show that the energy consumption required to keep the synchronized regime can be spontaneously reduced if the receiving neuron has adaptive mechanisms able to bring its biological parameters closer in value to the corresponding ones in the sending neuron.

  5. Hybrid function projective synchronization in complex dynamical networks

    SciTech Connect (OSTI)

    Wei, Qiang; Wang, Xing-yuan, E-mail: wangxy@dlut.edu.cn; Hu, Xiao-peng [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, 116024 (China)] [Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, 116024 (China)

    2014-02-15

    This paper investigates hybrid function projective synchronization in complex dynamical networks. When the complex dynamical networks could be synchronized up to an equilibrium or periodic orbit, a hybrid feedback controller is designed to realize the different component of vector of node could be synchronized up to different desired scaling function in complex dynamical networks with time delay. Hybrid function projective synchronization (HFPS) in complex dynamical networks with constant delay and HFPS in complex dynamical networks with time-varying coupling delay are researched, respectively. Finally, the numerical simulations show the effectiveness of theoretical analysis.

  6. Symmetric Clock Synchronization in Sensor Networks Philipp Sommer

    E-Print Network [OSTI]

    Symmetric Clock Synchronization in Sensor Networks Philipp Sommer Computer Engineering and Networks Laboratory ETH Zurich 8092 Zurich, Switzerland sommer@tik.ee.ethz.ch Roger Wattenhofer Computer Engineering

  7. Cluster Explosive Synchronization in a Power Grid model

    E-Print Network [OSTI]

    Ji, Peng; Menck, Peter J; Rodrigues, Francisco A; Kurths, Jürgen

    2013-01-01

    The emergence of explosive synchronization has been reported as an abrupt transition in complex networks of first-order Kuramoto oscillators. In this Letter, we demonstrate that the nodes in a power grid model, equivalent to a second-order Kuramoto model, perform a cascade of transitions toward a synchronous macroscopic state, a novel phenomenon that we call cluster explosive synchronization. We provide a rigorous analytical treatment using a mean-field analysis in uncorrelated networks. Our findings are in good agreement with numerical simulations and fundamentally deepen the understanding of microscopic mechanisms toward synchronization.

  8. Chaos synchronization in long-range coupled map lattices

    E-Print Network [OSTI]

    C. Anteneodo; A. M. Batista; R. L. Viana

    2004-01-22

    We investigate the synchronization phenomenon in coupled chaotic map lattices where the couplings decay with distance following a power-law. Depending on the lattice size, the coupling strength and the range of the interactions, complete chaos synchronization may be attained. The synchronization domain in parameter space can be analytically delimited by means of the condition of negativity of the largest transversal Lyapunov exponent. Here we analyze in detail the role of all the system parameters in the ability of the lattice to achieve complete synchronization, testing analytical results with the outcomes of numerical experiments.

  9. Optimization of synchronization in gradient clustered networks

    E-Print Network [OSTI]

    Xingang Wang; Liang Huang; Ying-Cheng Lai; Choy Heng Lai

    2007-11-23

    We consider complex clustered networks with a gradient structure, where sizes of the clusters are distributed unevenly. Such networks describe more closely actual networks in biophysical systems and in technological applications than previous models. Theoretical analysis predicts that the network synchronizability can be optimized by the strength of the gradient field but only when the gradient field points from large to small clusters. A remarkable finding is that, if the gradient field is sufficiently strong, synchronizability of the network is mainly determined by the properties of the subnetworks in the two largest clusters. These results are verified by numerical eigenvalue analysis and by direct simulation of synchronization dynamics on coupled-oscillator networks.

  10. Systems and methods for creation of conducting networks of magnetic particles through dynamic self-assembly process

    DOE Patents [OSTI]

    Snezhko, Oleksiy (Woodridge, IL); Aronson, Igor (Darien, IL); Kwok, Wai-Kwong (Downers Grove, IL)

    2011-01-25

    Self-assembly of magnetic microparticles in AC magnetic fields. Excitation of the system by an AC magnetic field provides a variety of patterns that can be controlled by adjusting the frequency and the amplitude of the field. At low particle densities the low-frequency magnetic excitation favors cluster phase formation, while high frequency excitation favors chains and netlike structures. For denser configurations, an abrupt transition to the network phase was obtained.

  11. On synchronous robotic networks - Part II: Time complexity of rendezvous and deployment algorithms

    E-Print Network [OSTI]

    Frazzoli, Emilio; Bullo, Francesco; Cortes, Jorge; Martinez, Sonia

    2007-01-01

    et al. : SYNCHRONOUS ROBOTIC NETWORKS—PART II control andFrazzoli, “On synchronous robotic networks—Part I: Models,et al. : SYNCHRONOUS ROBOTIC NETWORKS—PART II links. ) We

  12. Solid State AC Motor Drives - Conservation Perspectives 

    E-Print Network [OSTI]

    Mohan, N.; Ferraro, R. J.

    1982-01-01

    Variable Frequency Solid-State Inverters: can control the speed of ac motors by producing adjustable frequency ac voltage, with an enormous potential for energy conservation in pumps and air handling systems. 3. Other Variable Frequency Drives: include...

  13. Nuclear structure of Ac-231

    E-Print Network [OSTI]

    R. Boutami; M. J. G. Borge; H. Mach; W. Kurcewicz; L. M. Fraile; K. Gulda; A. J. Aas; L. M. García-Raffi; G. Løvhøiden; T. Martínez; B. Rubio; J. L. Taín; O. Tengblad

    2008-08-06

    The low-energy structure of 231Ac has been investigated by means of gamma ray spectroscopy following the beta-decay of 231Ra. Multipolarities of 28 transitions have been established by measuring conversion electrons with a mini-orange electron spectrometer. The decay scheme of 231Ra --> 231Ac has been constructed for the first time. The Advanced Time Delayed beta-gamma-gamma(t) method has been used to measure the half-lives of five levels. The moderately fast B(E1) transition rates derived suggest that the octupole effects, albeit weak, are still present in this exotic nucleus.

  14. DISS. ETH NO. 19459 Synchronization and Symmetry Breaking

    E-Print Network [OSTI]

    Waldmann, Uwe

    DISS. ETH NO. 19459 Synchronization and Symmetry Breaking in Distributed Systems A dissertation of the system's resources becomes a fascinating and challenging task. This dissertation treats of several such coordination problems arising in distributed systems. In the clock synchronization problem, devices carry

  15. Synchronous Binarization for Machine Translation Computer Science Department

    E-Print Network [OSTI]

    Gildea, Daniel

    Synchronous Binarization for Machine Translation Hao Zhang Computer Science Department University Systems based on synchronous grammars and tree transducers promise to improve the quality of statistical machine transla- tion output, but are often very computa- tionally intensive. The complexity is ex

  16. Equisolvability of Series vs. Controller's Topology in Synchronous Language Equations

    E-Print Network [OSTI]

    Brayton, Robert K.

    Equisolvability of Series vs. Controller's Topology in Synchronous Language Equations Nina operators for abstract languages: synchronous composition, #15;, and parallel composition, #5;, and we studied the solutions of the equations defined over finite state machines (FSMs) of the type MA #15; MX

  17. Symmetric Clock Synchronization in Sensor Networks Philipp Sommer

    E-Print Network [OSTI]

    Efficiency 1 Introduction Clock synchronization is a major building block in wire- less sensor networks, and maybe even more importantly, clock synchronization plays a major role in energy efficiency. State-of-the art energy-efficient sen- sor network protocols, e.g. [2], have advanced duty cycling schemes. Nodes

  18. Synchronous Machine Parameter Estimation Using Orthogonal Series Expansion

    E-Print Network [OSTI]

    Synchronous Machine Parameter Estimation Using Orthogonal Series Expansion J. Rico G. T. Heydt A an alternative to estimate armature circuit parameters of large utility generators using real time operating data of digital fault recorder data to identify synchronous machine parameters. 1. INTRODUCTION The use orthogonal

  19. Actuation system for transmission synchronizer providing regulated engagement pressure

    SciTech Connect (OSTI)

    Akashi, T.; Ito, H.; Yamada, S.

    1986-08-05

    This patent describes a transmission for a vehicle, comprising a rotary power input member, a rotary power output member, and a synchronizer for selectively torque-transmittingly connecting the power input member to the power output member. The synchronizer consists of a first rotary member rotatably around an axis and constantly torque-transmittingly connected with the power input member, a second rotary member rotatably around the axis and constantly torque-transmittingly connected with the power output member, a synchronizer sleeve rotatable around the axis and constantly torque-transmittingly connected with one of the first and second rotary members. The synchronizer sleeve is axially movable relative to the one rotary member so for as torque-transmittingly to mesh with the other of the first and second rotary members, and a synchronizer ring rotatable around the axis and torque-transmittingly connected with the one rotary member when the synchronizer sleeve is axially moved toward the other of the first and second rotary members. The synchronizer ring is frictionally engagable with the other rotary member so as to make rotations of the first and second rotary members approach to one another toward synchronization therebetween when frictionally pressed against the other rotary member.

  20. Processus communicants Communication synchrone CSP/CCS/-calcul

    E-Print Network [OSTI]

    Grigoras, .Romulus

    Processus communicants Communication synchrone CSP/CCS/-calcul Rendez-vous étendu Ada Huitième partie Processus communicants CSP/Ada Systèmes concurrents 2 / 44 #12;Processus communicants Communication synchrone CSP/CCS/-calcul Rendez-vous étendu Ada Principes Synchronisation Désignation

  1. Controlling synchronization in large laser networks using number theory

    E-Print Network [OSTI]

    Micha Nixon; Moti Fridman; Eitan Ronen; Asher A. Friesem; Nir Davidson; Ido Kanter

    2011-12-18

    Synchronization in networks with delayed coupling are ubiquitous in nature and play a key role in almost all fields of science including physics, biology, ecology, climatology and sociology. In general, the published works on network synchronization are based on data analysis and simulations, with little experimental verification. Here we develop and experimentally demonstrate various multi-cluster phase synchronization scenarios within coupled laser networks. Synchronization is controlled by the network connectivity in accordance to number theory, whereby the number of synchronized clusters equals the greatest common divisor of network loops. This dependence enables remote switching mechanisms to control the optical phase coherence among distant lasers by local network connectivity adjustments. Our results serve as a benchmark for a broad range of coupled oscillators in science and technology, and offer feasible routes to achieve multi-user secure protocols in communication networks and parallel distribution of versatile complex combinatorial tasks in optical computers.

  2. AA Architecture Building AC Athletics

    E-Print Network [OSTI]

    Kranakis, Evangelos

    $ AA Architecture Building AC Athletics AH Alumni Hall AP Azrieli Pavilion AT Azrieli Theatre CB Canal Building CC Colonel By Child Care Centre CO Residence Commons (Fenn Lounge) DH Dundas House DT Dunton Tower Interaction Building HP Herzberg Laboratories IH Ice House LA Loeb Building LE Leeds House LH Lanark House LS

  3. Summary Report on Synchronization, Diagnostics and Instrumentation

    SciTech Connect (OSTI)

    Arne Freyberger

    2005-03-19

    The proceedings of Working Group 4 of the 2005 Energy Recovery Linac (ERL) workshop are summarized. Working Group 4 dealt with the challenging topic of beam diagnostics for ERL machines. Energy Recovery Linacs represent a challenge for beam diagnostics from several perspectives; invasive versus non-invasive diagnostics, longitudinal and transverse beam diagnostics, overall machine timing/synchronization and machine protection. Beam diagnostics for an ERL can benefit strongly from the experience at third generation light sources, recirculating linacs and presently operating ERLs. During the workshop there were presentations from all these communities, representing a large range operation experience in beam diagnostics. A brief summary Working Group 4 discussion is presented in this paper.

  4. Simultaneous distribution of AC and DC power

    DOE Patents [OSTI]

    Polese, Luigi Gentile

    2015-09-15

    A system and method for the transport and distribution of both AC (alternating current) power and DC (direct current) power over wiring infrastructure normally used for distributing AC power only, for example, residential and/or commercial buildings' electrical wires is disclosed and taught. The system and method permits the combining of AC and DC power sources and the simultaneous distribution of the resulting power over the same wiring. At the utilization site a complementary device permits the separation of the DC power from the AC power and their reconstruction, for use in conventional AC-only and DC-only devices.

  5. Synchronous motor with soft start element formed between the motor rotor and motor output shaft to successfully synchronize loads that have high inertia and/or high torque

    DOE Patents [OSTI]

    Umans, Stephen D; Nisley, Donald L; Melfi, Michael J

    2014-10-28

    A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

  6. Synchronization of networks of oscillators with distributed delay coupling

    E-Print Network [OSTI]

    Y. N. Kyrychko; K. B. Blyuss; E. Schoell

    2014-10-27

    This paper studies the stability of synchronized states in networks where couplings between nodes are characterized by some distributed time delay, and develops a generalized master stability function approach. Using a generic example of Stuart-Landau oscillators, it is shown how the stability of synchronized solutions in networks with distributed delay coupling can be determined through a semi-analytic computation of Floquet exponents. The analysis of stability of fully synchronized and of cluster or splay states is illustrated for several practically important choices of delay distributions and network topologies.

  7. Cluster synchronization in networks of neurons with chemical synapses

    SciTech Connect (OSTI)

    Juang, Jonq, E-mail: jjuang@math.nctu.edu.tw [Department of Applied Mathematics, and Center of Mathematics Modeling and Scientific Computing, National Chiao Tung University, Hsinchu, Taiwan and National Center for Theoretical Sciences, Hsinchu, Taiwan (China)] [Department of Applied Mathematics, and Center of Mathematics Modeling and Scientific Computing, National Chiao Tung University, Hsinchu, Taiwan and National Center for Theoretical Sciences, Hsinchu, Taiwan (China); Liang, Yu-Hao, E-mail: moonsea.am96g@g2.nctu.edu.tw [Department of Mathematics, National Tsing Hua University, Hsinchu, Taiwan (China)] [Department of Mathematics, National Tsing Hua University, Hsinchu, Taiwan (China)

    2014-03-15

    In this work, we study the cluster synchronization of chemically coupled and generally formulated networks which are allowed to be nonidentical. The sufficient condition for the existence of stably synchronous clusters is derived. Specifically, we only need to check the stability of the origins of m decoupled linear systems. Here, m is the number of subpopulations. Examples of nonidentical networks such as Hindmarsh-Rose (HR) neurons with various choices of parameters in different subpopulations, or HR neurons in one subpopulation and FitzHugh-Nagumo neurons in the other subpopulation are provided. Explicit threshold for the coupling strength that guarantees the stably cluster synchronization can be obtained.

  8. Some aspects of the synchronization in coupled maps

    E-Print Network [OSTI]

    Sandro E. de Souza Pinto; José T. Lunardi; Abdala M. Saleh; Antonio M. Batista

    2005-04-06

    Through numerical simulations we analyze the synchronization time and the Lyapunov dimension of a coupled map lattice consisting of a chain of chaotic logistic maps exhibiting power law interactions. From the observed behaviors we find a lower bound for the size $N$ of the lattice, independent of the range and strength of the interaction, which imposes a practical lower bound in numerical simulations for the system to be considered in the thermodynamic limit. We also observe the existence of a strong correlation between the averaged synchronization time and the Lyapunov dimension. This is an interesting result because it allows an analytical estimation of the synchronization time, which otherwise requires numerical simulations.

  9. Superconducting magnetic energy storage for asynchronous electrical systems

    DOE Patents [OSTI]

    Boenig, H.J.

    1984-05-16

    It is an object of the present invention to provide superconducting magnetic energy storage for a plurality of asynchronous electrical systems. It is a further object of the present invention to provide load leveling and stability improvement in a plurality of independent ac systems using a single superconducting magnetic energy storage coil.

  10. Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits

    DOE Patents [OSTI]

    Campbell, A.N.; Anderson, R.E.; Cole, E.I. Jr.

    1995-11-07

    A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits are disclosed. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits. 17 figs.

  11. Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits

    DOE Patents [OSTI]

    Campbell, Ann. N. (13170-B Central SE #188, Albuquerque, NM 87123); Anderson, Richard E. (2800 Tennessee NE, Albuquerque, NM 87110); Cole, Jr., Edward I. (2116 White Cloud NE, Albuquerque, NM 87112)

    1995-01-01

    A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits.

  12. Synchronization of two Rossler systems with switching coupling

    E-Print Network [OSTI]

    Mattia Frasca; Arturo Buscarino; Marco Branciforte; Luigi Fortuna; Julien Clinton Sprott

    2015-07-07

    In this paper, we study a system of two Rossler oscillators coupled through a time-varying link, periodically switching between two values. We analyze the system behavior with respect to the frequency of the switching. By applying an averaging technique under the hypothesis of a high switching frequency, we find that although each value of the coupling does not produce synchronization, switching between the two at a high frequency stabilizes the synchronization manifold. However, we also find windows of synchronization below the value predicted by this technique, and we develop a master stability function to explain the appearance of these windows. Spectral properties of the system are a useful tool for understanding the dynamical properties and the synchronization failure in some intervals of the switching frequency. Numerical and experimental results in agreement with the analysis are presented.

  13. Chaos anti-synchronization in multiple time delay power systems

    E-Print Network [OSTI]

    Elman Shahverdiev

    2015-09-20

    We elucidate conditions for chaos anti-synchronization between two uni-directionally coupled multiple time delay power systems. The results are of some importance to prevent power black-out in the entire power grid.

  14. Performance analysis of synchronous machines under dynamic eccentricity 

    E-Print Network [OSTI]

    Al-Nuaim, Nabil Abdulaziz

    1996-01-01

    The performance of salient pole synchronous machines under eccentric rotors is studied. Relationships between stator and rotor current induced harmonics and dynamic eccentricity are investigated. The winding function theory has been modified...

  15. Title of Dissertation: LOW DIMENSIONAL CHAOS: PHASE SYNCHRONIZATION AND

    E-Print Network [OSTI]

    Anlage, Steven

    .2 Model Dynamical System . . . . . . . . . . . . . . . . . . . . . . . . 6 2.3 Results systems: Phase Synchronization of Chaos in the Presence of Two Competing Periodic Signals, and Saddle 2003 Advisory Committee: Professor Edward Ott, Chairman/Advisor Professor Rajarshi Roy Professor Thomas

  16. Synchronized Collective Behavior via Low-cost Communication

    E-Print Network [OSTI]

    Hai-Tao Zhang; Michael ZhiQiang Chen; Tao Zhou

    2007-07-23

    An important natural phenomenon surfaces that satisfactory synchronization of self-driven particles can be achieved via sharply reduced communication cost, especially for high density particle groups with low external noise. Statistical numerical evidence illustrates that a highly efficient manner is to distribute the communication messages as evenly as possible along the whole dynamic process, since it minimizes the communication redundancy. More surprisingly, it is discovered that there exist some abnormal regions where moderately decreasing the communication cost can even improve the synchronization performance. A phase diagram on the noise-density parameter space is given, where the dynamical behaviors can be divided into three qualitatively different phases: normal phase where better synchronization corresponds to higher communication cost, abnormal phase where moderately decreasing communication cost could even improve the synchronization, and the disordered phase where no coherence among individuals is observed.

  17. Synchronization Techniques for Burst-Mode Continuous Phase Modulation

    E-Print Network [OSTI]

    Hosseini, Ehsan

    2013-12-31

    , phase, and timing offsets. Based on our transmission model, we derive the Cramer-Rao bound (CRB) for DA joint estimation of synchronization parameters. Using the CRB expressions, the optimum training sequence for CPM signals is proposed. It is shown...

  18. Lock Prediction to Reduce the Overhead of Synchronization Primitives 

    E-Print Network [OSTI]

    Shankar, Anusha

    2014-12-03

    access on shared data structures using lock and unlock operations. These operations are implemented in hardware as a set of instructions that atomically read and then write to a single memory location. Good synchronization techniques should try to reduce...

  19. A Greedy Distributed Time Synchronization Algorithm for Wireless Sensor Networks

    E-Print Network [OSTI]

    Tam, Vincent W. L.

    synchronizations performed. I. INTRODUCTION With the advance in various enabling technologies like Micro-Electro-Mechanical System (MEMS), signal process- ing and wireless communication, wireless sensor networks (WSNs) have drawn

  20. Compiling Synchronous Kahn Networks to Efficient Reconfigurable Hardware

    E-Print Network [OSTI]

    Vuillemin, Jean

    Compiling Synchronous Kahn Networks to Efficient Reconfigurable Hardware Jean Vuillemin , Jean research on automatically compiling efficient reconfigurable hardware from high level software stream. Commercial systems exist to generate hardware (say VHDL) from high-level (say C) code [6]. Yet

  1. Experimental Comparison of Synchronous-Clock Cooperative Acoustic Navigation Algorithms

    E-Print Network [OSTI]

    Eustice, Ryan

    growth as subsea vehicles do not typically have access to an absolute position reference. Synchronous absolute position reference. Subsea and topside nodes are color coded by blue and green, respectively

  2. Improved lumped parameter thermal modelling of synchronous generators 

    E-Print Network [OSTI]

    Mejuto, Carlos

    2010-01-01

    Within the existing available mix of numerical and analytical thermal analysis options, lumped parameter thermal modelling is selected as the operational backbone to develop an improved novel synchronous generator thermal ...

  3. Robust Clock Synchronization Methods for Wireless Sensor Networks 

    E-Print Network [OSTI]

    Lee, Jae Han

    2011-10-21

    in general with energy-limited sensors capable of collecting, processing and transmitting information across short distances. Clock synchronization plays an important role in designing, implementing, and operating wireless sensor networks, and it is essential...

  4. Synchronization of multiple coupled rf-SQUID flux qubits

    E-Print Network [OSTI]

    Harris, R.; Brito, F.; Berkley, A. J.; Jonansson, J.; Johnson, M. W.; Lanting, T.; Bunyk, P.; Ladizinsky, E.; Bumble, B.; Fung, A.; Kaul, A.; Kleinsasser, A.; Han, Siyuan

    2009-12-19

    %) fabrication variations in qubit inductance and critical current can be minimized by the application of a custom-tuned flux offset to the CJJ structure of each qubit. This strategy allows for a simultaneous synchronization of the qubit persistent current...

  5. Current Controller with Defined Dynamic Behavior for an Interior Permanent Magnet

    E-Print Network [OSTI]

    Noé, Reinhold

    Current Controller with Defined Dynamic Behavior for an Interior Permanent Magnet Synchronous Motor combustion vehicles already provide. Today's modern HEV and EV mostly include interior permanent magnet]. The required torque, which is the reference variable for these applications, is generated by choosing

  6. Projective synchronization in fractional order chaotic systems and its control

    E-Print Network [OSTI]

    Chunguang Li

    2006-04-24

    The chaotic dynamics of fractional (non-integer) order systems have begun to attract much attention in recent years. In this paper, we study the projective synchronization in two coupled fractional order chaotic oscillators. It is shown that projective synchronization can also exist in coupled fractional order chaotic systems. A simple feedback control method for controlling the scaling factor onto a desired value is also presented.

  7. Low latency memory access and synchronization

    DOE Patents [OSTI]

    Blumrich, Matthias A. (Ridgefield, CT); Chen, Dong (Croton On Hudson, NY); Coteus, Paul W. (Yorktown Heights, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Hoenicke, Dirk (Ossining, NY); Ohmacht, Martin (Brewster, NY); Steinmacher-Burow, Burkhard D. (Mount Kisco, NY); Takken, Todd E. (Mount Kisco, NY); Vranas, Pavlos M. (Bedford Hills, NY)

    2007-02-06

    A low latency memory system access is provided in association with a weakly-ordered multiprocessor system. Each processor in the multiprocessor shares resources, and each shared resource has an associated lock within a locking device that provides support for synchronization between the multiple processors in the multiprocessor and the orderly sharing of the resources. A processor only has permission to access a resource when it owns the lock associated with that resource, and an attempt by a processor to own a lock requires only a single load operation, rather than a traditional atomic load followed by store, such that the processor only performs a read operation and the hardware locking device performs a subsequent write operation rather than the processor. A simple prefetching for non-contiguous data structures is also disclosed. A memory line is redefined so that in addition to the normal physical memory data, every line includes a pointer that is large enough to point to any other line in the memory, wherein the pointers to determine which memory line to prefetch rather than some other predictive algorithm. This enables hardware to effectively prefetch memory access patterns that are non-contiguous, but repetitive.

  8. Low latency memory access and synchronization

    DOE Patents [OSTI]

    Blumrich, Matthias A. (Ridgefield, CT); Chen, Dong (Croton On Hudson, NY); Coteus, Paul W. (Yorktown Heights, NY); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Hoenicke, Dirk (Ossining, NY); Ohmacht, Martin (Brewster, NY); Steinmacher-Burow, Burkhard D. (Mount Kisco, NY); Takken, Todd E. (Mount Kisco, NY), Vranas; Pavlos M. (Bedford Hills, NY)

    2010-10-19

    A low latency memory system access is provided in association with a weakly-ordered multiprocessor system. Bach processor in the multiprocessor shares resources, and each shared resource has an associated lock within a locking device that provides support for synchronization between the multiple processors in the multiprocessor and the orderly sharing of the resources. A processor only has permission to access a resource when it owns the lock associated with that resource, and an attempt by a processor to own a lock requires only a single load operation, rather than a traditional atomic load followed by store, such that the processor only performs a read operation and the hardware locking device performs a subsequent write operation rather than the processor. A simple prefetching for non-contiguous data structures is also disclosed. A memory line is redefined so that in addition to the normal physical memory data, every line includes a pointer that is large enough to point to any other line in the memory, wherein the pointers to determine which memory line to prefetch rather than some other predictive algorithm. This enables hardware to effectively prefetch memory access patterns that are non-contiguous, but repetitive.

  9. Cosmic magnetism

    SciTech Connect (OSTI)

    Seymour, P.

    1986-01-01

    This book deals with the cosmic magnetism in a non-mathematical way. It uses Faraday's very powerful and highly pictorial concept of lines of magnetic force and their associated physical properties to explain the structure and behavior of magnetic fields in extraterrestrial objects. Contents include: forces of nature; magnetic field of earth; solar and interplanetary magnetic fields; magnetic fields in the solar system; stars and pulsars; and magnetic fields of the milky way and other galaxies.

  10. AC Loss Analysis on the Superconducting Coupling Magnet in MICE

    E-Print Network [OSTI]

    Wu, Hong

    2009-01-01

    of Cryogenics and Superconductivity Technology, Harbinof cryogenics and superconductivity engineering technologyof Cryogenics and Superconductivity Technology, “Engineering

  11. Generation of synchronized trains of picosecond laser pulses at two wavelengths in a single-cavity synchronously mode-locked dye laser

    E-Print Network [OSTI]

    Rocca, Jorge J.

    Generation of synchronized trains of picosecond laser pulses at two wavelengths in a single September 1992) Synchronized trains of 5 ps pulses at two wavelengths were generated in a single-cavity synchronously mode-locked dye laser 0. Buccafusca, J. J. Rocca, M. C. Marconi, and C. S. Menoni National Science

  12. ROTATIONAL SYNCHRONIZATION MAY ENHANCE HABITABILITY FOR CIRCUMBINARY PLANETS: KEPLER BINARY CASE STUDIES

    SciTech Connect (OSTI)

    Mason, Paul A.; Zuluaga, Jorge I.; Cuartas-Restrepo, Pablo A.; Clark, Joni M.

    2013-09-10

    We report a mechanism capable of reducing (or increasing) stellar activity in binary stars, thereby potentially enhancing (or destroying) circumbinary habitability. In single stars, stellar aggression toward planetary atmospheres causes mass-loss, which is especially detrimental for late-type stars, because habitable zones are very close and activity is long lasting. In binaries, tidal rotational breaking reduces magnetic activity, thus reducing harmful levels of X-ray and ultraviolet (XUV) radiation and stellar mass-loss that are able to erode planetary atmospheres. We study this mechanism for all confirmed circumbinary (p-type) planets. We find that main sequence twins provide minimal flux variation and in some cases improved environments if the stars rotationally synchronize within the first Gyr. Solar-like twins, like Kepler 34 and Kepler 35, provide low habitable zone XUV fluxes and stellar wind pressures. These wide, moist, habitable zones may potentially support multiple habitable planets. Solar-type stars with lower mass companions, like Kepler 47, allow for protected planets over a wide range of secondary masses and binary periods. Kepler 38 and related binaries are marginal cases. Kepler 64 and analogs have dramatically reduced stellar aggression due to synchronization of the primary, but are limited by the short lifetime. Kepler 16 appears to be inhospitable to planets due to extreme XUV flux. These results have important implications for estimates of the number of stellar systems containing habitable planets in the Galaxy and allow for the selection of binaries suitable for follow-up searches for habitable planets.

  13. High frequency AC power converter for low voltage circuits

    E-Print Network [OSTI]

    Salazar, Nathaniel Jay Tobias

    2012-01-01

    This thesis presents a novel AC power delivery architecture that is suitable for VHF frequency (50-100MHz) polyphase AC/DC power conversion in low voltage integrated circuits. A complete AC power delivery architecture was ...

  14. Superconducting magnet development in Japan

    SciTech Connect (OSTI)

    Yasukochi, K.

    1983-05-01

    The present state of R and D works on the superconducting magnet and its applications in Japan are presented. On electrical rotating machines, 30 MVA superconducting synchronous rotary condenser (Mitsubishi and Fuji) and 50 MVA generator are under construction. Two ways of ship propulsion by superconducting magnets are developing. A superconducting magnetically levitated and linear motor propelled train ''MAGLEV'' was developed by the Japan National Railways (JNR). The superconducting magnet development for fusion is the most active field in Japan. The Cluster Test program has been demonstrated on a 10 T Nb/sub 3/Sn coil and the first coil of Large Coil Task in IEA collaboration has been constructed and the domestic test was completed in JAERI. These works are for the development of toroidal coils of the next generation tokamak machine. R and D works on superconducting ohmic heating coil are in progress in JAERI and ETL. The latter group has constructed 3.8 MJ pulsed coil. A high ramp rate of changing field in pulsed magnet, 200 T/s, has been tested successfully. High Energy Physics Laboratory (KEK) are conducting active works. The superconducting ..mu.. meson channel and ..pi.. meson channel have been constructed and are operating successfully. KEK has also a project of big accelerator named ''TRISTAN'', which is similar to ISABELLE project of BNL. Superconducting synchrotron magnets are developed for this project. The development of superconducting three thin wall solenoid has been started. One of them, CDF, is progressing under USA-Japan collaboration.

  15. AC Transit | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Financing ToolInternationalReportOffice | DepartmentVery1, in:QuarterlyA SolarAADensifiedAC

  16. Gravitational resonance spectroscopy with an oscillating magnetic field gradient in the GRANIT flow through arrangement

    E-Print Network [OSTI]

    G. Pignol; S. Baessler; V. V. Nesvizhevsky; K. Protasov; D. Rebreyend; A. Yu. Voronin

    2014-08-05

    Gravitational resonance spectroscopy consists in measuring the energy spectrum of bouncing ultracold neutrons above a mirror by inducing resonant transitions between different discrete quantum levels. We discuss how to induce the resonances with a flow through arrangement in the GRANIT spectrometer, excited by an oscillating magnetic field gradient. The spectroscopy could be realized in two distinct modes (so called DC and AC) using the same device to produce the magnetic excitation. We present calculations demonstrating the feasibility of the newly proposed AC mode.

  17. A two-factor saturation model for synchronous machines with multiple rotor circuits

    SciTech Connect (OSTI)

    Tahan, S.A. [Universite Laval, Quebec (Canada)] [Universite Laval, Quebec (Canada); Kamwa, I. [Institut de Recherche d`Hydro-Quebec, Varennes, Quebec (Canada)] [Institut de Recherche d`Hydro-Quebec, Varennes, Quebec (Canada)

    1995-12-01

    It is generally felt that no major accuracy break-through in predicting the steady-state and transient performance of synchronous machines could be achieved without taking proper account of the iron saturation effects as well as eddy-current losses. Although the two issues were often treated separately in the past, this paper attempts to unite them by developing a general model covering both the main-path magnetic saturation and frequency effects in the dynamic equations. Mathematical analysis in the d-q space pinpoints cross-saturation coupling which, a priori, does not seem to be symmetrical for salient-pole machines. Yet the model is theoretically sound, since it fulfills at least the physical constraints using energy balance principles. Some test points from a 555-MVA turbine-generator are used for an initial assessment of the model`s capability to predict the field current and internal angle for various loading conditions.

  18. www.accommodation.salford.ac.uk Accommodation

    E-Print Network [OSTI]

    Romano, Daniela

    sets out the main elements of good management practice. It covers health and safety, maintenancewww.accommodation.salford.ac.uk Accommodation Guide to University and University partner accommodation #12;32 www.accommodation.salford.ac.ukA guide to University and Partner accommodation Welcome

  19. Synchronization in Complex Oscillator Networks and Smart Grids

    E-Print Network [OSTI]

    Florian Dörfler; Michael Chertkov; Francesco Bullo

    2012-07-31

    The emergence of synchronization in a network of coupled oscillators is a fascinating topic in various scientific disciplines. A coupled oscillator network is characterized by a population of heterogeneous oscillators and a graph describing the interaction among them. It is known that a strongly coupled and sufficiently homogeneous network synchronizes, but the exact threshold from incoherence to synchrony is unknown. Here we present a novel, concise, and closed-form condition for synchronization of the fully nonlinear, non-equilibrium, and dynamic network. Our synchronization condition can be stated elegantly in terms of the network topology and parameters, or equivalently in terms of an intuitive, linear, and static auxiliary system. Our results significantly improve upon the existing conditions advocated thus far, they are provably exact for various interesting network topologies and parameters, they are statistically correct for almost all networks, and they can be applied equally to synchronization phenomena arising in physics and biology as well as in engineered oscillator networks such as electric power networks. We illustrate the validity, the accuracy, and the practical applicability of our results in complex networks scenarios and in smart grid applications.

  20. Synchronization in node of complex networks consist of complex chaotic system

    SciTech Connect (OSTI)

    Wei, Qiang, E-mail: qiangweibeihua@163.com [Beihua University computer and technology College, BeiHua University, Jilin, 132021, Jilin (China); Digital Images Processing Institute of Beihua University, BeiHua University, Jilin, 132011, Jilin (China); Faculty of Electronic Information and Electrical Engineering, Dalian University of Technology, Dalian, 116024 (China); Xie, Cheng-jun [Beihua University computer and technology College, BeiHua University, Jilin, 132021, Jilin (China); Digital Images Processing Institute of Beihua University, BeiHua University, Jilin, 132011, Jilin (China); Liu, Hong-jun [School of Information Engineering, Weifang Vocational College, Weifang, 261041 (China); Li, Yan-hui [The Library, Weifang Vocational College, Weifang, 261041 (China)

    2014-07-15

    A new synchronization method is investigated for node of complex networks consists of complex chaotic system. When complex networks realize synchronization, different component of complex state variable synchronize up to different scaling complex function by a designed complex feedback controller. This paper change synchronization scaling function from real field to complex field for synchronization in node of complex networks with complex chaotic system. Synchronization in constant delay and time-varying coupling delay complex networks are investigated, respectively. Numerical simulations are provided to show the effectiveness of the proposed method.

  1. PREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76CH03073

    E-Print Network [OSTI]

    PREPARED FOR THE U.S. DEPARTMENT OF ENERGY, UNDER CONTRACT DE-AC02-76CH03073 PRINCETON PLASMA Acceleration in the Field-reversed Configuration (FRC) by Slowly Rotating Odd-parity Magnetic Fields (RMFo agency thereof. Availability This report is posted on the U.S. Department of Energy's Princeton Plasma

  2. Analysis of cluster explosive synchronization in complex networks

    E-Print Network [OSTI]

    Peng Ji; Thomas K. DM. Peron; Francisco A. Rodrigues; Jürgen Kurths

    2014-12-17

    Correlations between intrinsic dynamics and local topology have become a new trend in the study of synchronization in complex networks. In this paper, we investigate in this paradigm the influence of topology on dynamics of networks made up of second-order Kuramoto oscillators. In particular, based on mean-field calculations, we provide a detailed investigation of the recently reported phenomena of cluster explosive synchronization (CES)[Phys. Rev. Lett. 110, 218701 (2013)], analysing the model in scale-free and small-world networks as a function of several topological properties. We show that, in contrast to scale-free networks, the transition to the synchronous state in small-world structures tends to be continuous as the probability of rewiring increases. These results complement the previous findings regarding CES and also fundamentally deepen the understanding of the interplay between topology and dynamics under the constraint of correlating natural frequencies and local structure.

  3. Synchronization of multimedia streams over packet-switched networks 

    E-Print Network [OSTI]

    Brewer, Jason M.

    1995-01-01

    65 66 66 68 REFERENCES APPENDIX A 71 74 VITA 75 vm LIST OF TABLES TABLE Page I Compression options for VAT II Compression options for NeVoT LIST OF FIGURES FIGURE Page Density and PDF of NV encoding delay at 5 fps. 10 32-bit Cell code... of synchronized H. 261 video. 59 31 Playout offset along with audio delay. Playout off'set of unsynchronized NV video. 60 33 Playout off'set of synchronized NV video. 60 34 End-to-end delay with coding change in middle of sequence. 61 Tracking a change...

  4. Global synchronization of bursting neurons in clustered networks

    E-Print Network [OSTI]

    C. A. S. Batista; R. V. Nunes; A. M. Batista; R. L. Viana; S. R. Lopes; T. Pereira

    2010-12-20

    We investigate the collective dynamics of bursting neurons on clustered network. The clustered network is composed of subnetworks each presenting a small-world property, and in a given subnetwork each neuron has a probability to be connected to the other subnetworks. We give bounds for the critical coupling strength to obtain global burst synchronization in terms of the network structure, i.e., intracluster and intercluster probabilities connections. As the heterogeneity in the network is reduced the network global synchronization is improved. We show that the transitions to global synchrony may be abrupt or smooth depending on the intercluster probability.

  5. Time Synchronization in Hierarchical TESLA Wireless Sensor Networks

    SciTech Connect (OSTI)

    Jason L. Wright; Milos Manic

    2009-08-01

    Time synchronization and event time correlation are important in wireless sensor networks. In particular, time is used to create a sequence events or time line to answer questions of cause and effect. Time is also used as a basis for determining the freshness of received packets and the validity of cryptographic certificates. This paper presents secure method of time synchronization and event time correlation for TESLA-based hierarchical wireless sensor networks. The method demonstrates that events in a TESLA network can be accurately timestamped by adding only a few pieces of data to the existing protocol.

  6. Nonlinear control and synchronization of multiple Lagrangian systems with application to tethered formation flight spacecraft

    E-Print Network [OSTI]

    Chung, Soon-Jo, 1976-

    2007-01-01

    This dissertation focuses on the synchronization of multiple dynamical systems using contraction theory, with applications to cooperative control of multi-agent systems and synchronization of interconnected dynamics such ...

  7. Aalborg Universitet Distributed Active Synchronization Strategy for Microgrid Seamless Reconnection to

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Distributed Active Synchronization Strategy for Microgrid Seamless Reconnection Active Synchronization Strategy for Microgrid Seamless Reconnection to the Grid under Unbalance from vbn.aau.dk on: juli 05, 2015 #12;This document downloaded from www.microgrids

  8. New advances in designing energy efficient time synchronization schemes for wireless sensor networks 

    E-Print Network [OSTI]

    Noh, Kyoung Lae

    2009-05-15

    (PBS), which aims at minimizing the number of message transmissions and implicitly the energy consumption necessary for global synchronization of WSNs. A novel approach for time synchronization is adopted in PBS, where a group of sensor nodes...

  9. Modeling, Simulation, and Practice of Floor Control for Synchronous and Ubiquitous

    E-Print Network [OSTI]

    : Floor control, Ubiquitous collaboration, Synchronous collaboration, Mobile devices, Human-computer dispersed virtual place. Mobile computing paradigm [34] made ubiquitous access possible with the integration1 Modeling, Simulation, and Practice of Floor Control for Synchronous and Ubiquitous Collaboration

  10. Method of driving liquid flow at or near the free surface using magnetic microparticles

    DOE Patents [OSTI]

    Snezhko, Oleksiy (Woodridge, IL); Aronson, Igor (Darien, IL); Kwok, Wai-Kwong (Evanston, IL); Belkin, Maxim V. (Woodridge, IL)

    2011-10-11

    The present invention provides a method of driving liquid flow at or near a free surface using self-assembled structures composed of magnetic particles subjected to an external AC magnetic field. A plurality of magnetic particles are supported at or near a free surface of liquid by surface tension or buoyancy force. An AC magnetic field traverses the free surface and dipole-dipole interaction between particles produces in self-assembled snake structures which oscillate at the frequency of the traverse AC magnetic field. The snake structures independently move across the free surface and may merge with other snake structures or break up and coalesce into additional snake structures experiencing independent movement across the liquid surface. During this process, the snake structures produce asymmetric flow vortices across substantially the entirety of the free surface, effectuating liquid flow across the free surface.

  11. Magnetic field survey at PG&E photovoltaic sites

    SciTech Connect (OSTI)

    Chang, G.J.; Jennings, C.

    1994-08-01

    Public awareness has aroused concerns over the possible effects of magnetic fields on human health. While research continues to determine if magnetic fields do, in fact, affect human health, concerned individuals are requesting data on magnetic field sources in their environments to base personal decisions about limiting their exposure to these sources. Timely acceptance and implementation of photovoltaics (PV), particularly for distributed applications such as PV rooftops, windows, and vehicles, may be hampered by the lack of PV magnetic field data. To address this situation, magnetic flux density was measured around equipment at two PVUSA (Photovoltaics for Utility Scale Applications) project sites in Kerman and Davis, California. This report documents the data and compares the PV magnetic fields with published data on more prevalent magnetic field sources. Although not comprehensive, electric and magnetic field (EMF) data taken at PVUSA indicate that 60-Hz magnetic fields (the EMF type of greatest public concern) are significantly less for PV arrays than for household applications. Therefore, given the present EMF research knowledge, PV array EMF may not merit considerable concern. The PV system components exhibiting significant AC magnetic fields are the transformers and power conditioning units (PCUs). However, the AC magnetic fields associated with these components are localized and are not detected at PV system perimeters. Concern about transformer and PCU EMF would apply to several generation and storage technologies.

  12. Electro-Mechanical Resonant Magnetic Field Sensor

    E-Print Network [OSTI]

    Temnykh, A B; Temnykh, Alexander B.; Lovelace, Richard V. E.

    2002-01-01

    We describe a new type of magnetic field sensor which is termed an Electro-Mechanical Resonant Sensor (EMRS). The key part of this sensor is a small conductive elastic element with low damping rate and therefore a high Q fundamental mode of frequency $f_1$. An AC current is driven through the elastic element which, in the presence of a magnetic field, causes an AC force on the element. When the frequency of the AC current matches the resonant frequency of the element, maximum vibration of the element occurs and this can be measured precisely by optical means. We have built and tested a model sensor of this type using for the elastic element a length of copper wire of diameter 0.030 mm formed into a loop shape. The wire motion was measured using a light emitting diode photo-transistor assembly. This sensor demonstrated a sensitivity better than 0.001G for an applied magnetic field of $ \\sim 1$G and a good selectivity for the magnetic field direction. The sensitivity can be easily improved by a factor of $\\sim ...

  13. EESA: 802.11ac MU-MIMO spatial stream

    E-Print Network [OSTI]

    Bahk, Saewoong

    @snu.ac.kr EESA: Energy efficient spatial stream allocation technique in 802.11ac network Heo Jeong Ryun, Bahk Sae (1), (2) (1) . . spatial stream . 1 3. EESA(Energy Efficient 2014 EESA: 802.11ac MU-MIMO spatial stream , * jrheo@netlab.snu.ac.kr, sbahk

  14. www.mmu.ac.uk/careers Careers & Employability Service

    E-Print Network [OSTI]

    .mmu.ac.uk/careers Identifying courses · www.prospects.ac.uk/search_courses.htm · www.jobs.ac.uk · www.Findamasters.com · www.mmu.ac.uk/careers PG Professional/Vocational courses: Courses to allow you to enter certain professions Courses involve lectures for the first two terms then a research project for the final term (often finishing after

  15. Undergraduate study 2016 www.nottingham.ac.uk/medicine

    E-Print Network [OSTI]

    Qu, Rong

    Medicine Undergraduate study 2016 www.nottingham.ac.uk/medicine For general undergraduate enquiries: www.nottingham.ac.uk/faqs #12;21 School of Medicine www.nottingham.ac.uk/medicine School of Medicine www.nottingham.ac.uk/medicine Welcome to the School of Medicine You are about to embark

  16. Magnets & Magnet Condensed Matter Science

    E-Print Network [OSTI]

    McQuade, D. Tyler

    Sights from around the Magnet Lab in 2010. On the cover MAGNETS & MAGNET MATERIALS Engineering materials in Mesoporous Silica SBA-15 31 YBCO Pancake Wound Test Coil for 32-T Magnet Development 32 Strong Vortex Pinning from Marine Cyanobacteria 37 Heavy Petroleum Composition 2. Progression of the Boduszynski Model

  17. Simplified Modelling and Control of a Synchronous Machine with VariableSpeed SixStep Drive

    E-Print Network [OSTI]

    Sanders, Seth

    Simplified Modelling and Control of a Synchronous Machine with Variable­Speed Six­Step Drive on simple and intuitive techniques for the modelling of synchronous machines and their associated control design process for synchronous machines. What the two techniques have in common is a reliance

  18. Language Support for Synchronous Parallel Critical Sections Christoph W. Keler Helmut Seidl

    E-Print Network [OSTI]

    Kessler, Christoph

    elegant and effi­ cient programs for synchronous shared memory MIMD machines (also known as PRAM's). PRAMLanguage Support for Synchronous Parallel Critical Sections Christoph W. Ke�ler Helmut Seidl@psi.uni­trier.de Abstract We introduce a new parallel programming paradigm, namely synchronous parallel critical sections

  19. Linearized Analysis of the Synchronous Machine for PSS Chapter 6 does two basic things

    E-Print Network [OSTI]

    McCalley, James D.

    1 Linearized Analysis of the Synchronous Machine for PSS Chapter 6 does two basic things: 1. Shows-cct.") of a synchronous machine connected to an infinite bus using the current-state-space model (sections 6. Linearizes the one-axis model of a synchronous machine connected to an infinite bus (sections 6

  20. Language Support for Synchronous Parallel Critical Sections Christoph W. Ke ler Helmut Seidl

    E-Print Network [OSTI]

    Kessler, Christoph

    and e - cient programs for synchronous shared memory MIMD machines (also known as PRAM's). PRAMLanguage Support for Synchronous Parallel Critical Sections Christoph W. Ke ler Helmut Seidl@psi.uni-trier.de Abstract We introduce a new parallel programming paradigm, namely synchronous parallel critical sections

  1. The Synchronous Boltzmann Machine for learning and hard-combinatoric search

    E-Print Network [OSTI]

    Jones, Antonia J.

    The Synchronous Boltzmann Machine for learning and hard-combinatoric search Ursula X. Iturrarán. Learning with synchronous Boltzmann machines provides an attractive alternative provided that one can offer a suitable theoretical framework. The dynamics of the synchronous Boltzmann machine were first studied by W

  2. American Institute of Aeronautics and Astronautics Electromagnetic Design of Aircraft Synchronous Generator

    E-Print Network [OSTI]

    Wu, Thomas

    synchronous generator with high power-density. A new method is proposed to more accurately model the air power-density synchronous generator with 12 krpm rotational velocity is obtained. Finally, the design of an aircraft generator is shown in Fig. 1. The three-phase synchronous generator includes an outer stator

  3. Passivity-based control of a wound-rotor synchronous Arnau D`oria-Cerezoa

    E-Print Network [OSTI]

    Batlle, Carles

    rotor synchronous machine (WRSM) is used for generation and also for drive ap- plications [1 methods has been proposed in [9], and the specific cases for synchronous generators and drives canPassivity-based control of a wound-rotor synchronous motor Arnau D`oria-Cerezoa , Carles Batlleb

  4. RESTRICTING THE WEAK-GENERATIVE CAPACITY OF SYNCHRONOUS TREE-ADJOINING GRAMMARS

    E-Print Network [OSTI]

    Shieber, Stuart

    RESTRICTING THE WEAK-GENERATIVE CAPACITY OF SYNCHRONOUS TREE-ADJOINING GRAMMARS STUART M. SHIEBER: Synchronous tree-adjoining grammars, weak-generative ca- pacity, machine translation, natural reasons. First, the weak-generative expressivity of TAGs is increased through the synchronization

  5. Estimation of Synchronous Generator Parameters Using an Observer for Damper Currents and a Graphical User Interface

    E-Print Network [OSTI]

    Estimation of Synchronous Generator Parameters Using an Observer for Damper Currents@asu.edu ABSTRACT This paper presents a method to identify synchronous generator parameters from on-line data generator. #12;2 I. INTRODUCTION Synchronous generator parameter identification is a problem that has

  6. Estimating Reliability and Throughput of Source-synchronous Wave-pipelined Interconnect

    E-Print Network [OSTI]

    Lemieux, Guy

    Destination Clk gen Data Forwarded clock (generated at source) (c) SSWP: Source synchronous, wave pipelinedEstimating Reliability and Throughput of Source-synchronous Wave-pipelined Interconnect Paul Teehan to distinguish between static and dynamic sources of tim- ing uncertainty, because source-synchronous wave

  7. Asynchronous or synchronous? A misleading choice. Scott Fairbanks and Simon Moore

    E-Print Network [OSTI]

    Moore, Simon

    to generate and globally distribute timing signals. The first paper questions the synchronous assumptionsAsynchronous or synchronous? A misleading choice. Scott Fairbanks and Simon Moore 15 May 2004 as the technology that will progress the art of compu- tation when the timing assumptions that hold the synchronous

  8. 14th World Congress of IFACON ADAPTIVE OBSERVER-BASED SYNCHRONIZATION FOR COM... Copyright 1999 IFAC

    E-Print Network [OSTI]

    14th World Congress of IFACON ADAPTIVE OBSERVER-BASED SYNCHRONIZATION FOR COM... Copyright © 1999 ···· Synchronization ···· Communications ISBN: 0 08 043248 4Copyright 1999 IFAC #12;14th World Congress of IFACON ADAPTIVE OBSERVER-BASED SYNCHRONIZATION FOR COM... ISBN: 0 08 043248 4Copyright 1999 IFAC #12;14th World

  9. Wave Mediated Synchronization of Nonuniform Oscillatory Media On-Uma Kheowan,1,2

    E-Print Network [OSTI]

    Showalter, Kenneth

    Wave Mediated Synchronization of Nonuniform Oscillatory Media On-Uma Kheowan,1,2 Eugene Mihaliuk,1 frequencies. The medium evolves from an initial state of multiple wave sources to a synchronized state governed by a single wave source. The synchronization occurs via a competition between the sources, which

  10. The Complexity of Synchronous Notions of Information Flow Security

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    The Complexity of Synchronous Notions of Information Flow Security Franck Cassez1, , Ron van der flow security is concerned with the ability for agents in a system to deduce information about an information flow security policy has proved to be a subtle matter. A substantial literature has developed

  11. Wireless spread-spectrum telesensor chip with synchronous digital architecture

    DOE Patents [OSTI]

    Smith, Stephen F.; Turner, Gary W.; Wintenberg, Alan L.; Emery, Michael Steven

    2005-03-08

    A fully integrated wireless spread-spectrum sensor incorporating all elements of an "intelligent" sensor on a single circuit chip is capable of telemetering data to a receiver. Synchronous control of all elements of the chip provides low-cost, low-noise, and highly robust data transmission, in turn enabling the use of low-cost monolithic receivers.

  12. Music Synchronization, Audio Matching, Pattern Detection, and User Interfaces

    E-Print Network [OSTI]

    Clausen, Michael

    Library System Dissertation zur Erlangung des Doktorgrades (Dr. rer. nat.) der Mathematisch Synchronization, Audio Matching, Pattern Detection, and User Interfaces for a Digital Music Library System Verena scale. For music documents these trends are observable as well, and by now several digital music

  13. Self-Stabilizing Byzantine Agreement in a Synchronous Network

    E-Print Network [OSTI]

    Dolev, Danny

    Self-Stabilizing Byzantine Agreement in a Synchronous Network A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science by Tomer Harpaz Supervised by Prof. Danny and love. #12;Abstract This thesis presents an algorithm that provides self-stabilizing Byzantine agreement

  14. Hydrodynamic Flow Patterns and Synchronization of Beating Cilia Andrej Vilfan*

    E-Print Network [OSTI]

    Jülicher, Frank

    Hydrodynamic Flow Patterns and Synchronization of Beating Cilia Andrej Vilfan* J. Stefan Institute 2006) We calculate the hydrodynamic flow field generated far from a cilium which is attached to a surface and beats periodically. In the case of two beating cilia, hydrodynamic interactions can lead

  15. Time Synchronization between SOKUIKI Sensor and Host Computer using Timestamps

    E-Print Network [OSTI]

    Ohya, Akihisa

    Time Synchronization between SOKUIKI Sensor and Host Computer using Timestamps Alexander Carballo, Yoshitaka Hara, Hirohiko Kawata, Tomoaki Yoshida, Akihisa Ohya and Shin'ichi Yuta Abstract-- Time is crucial of sensor readings. The SOKUIKI scanning laser range finder allows acquiring time values by timestamping

  16. Time-synchronized Clustering of Gene Expression Trajectories

    E-Print Network [OSTI]

    Müller, Hans-Georg

    Time-synchronized Clustering of Gene Expression Trajectories RONG TANG Division of Biostatistics, USA ABSTRACT Current clustering methods are routinely applied to gene expression time course data at different rates, successful clustering in this context requires dealing with varying time and shape patterns

  17. Cryptanalyzing a discrete-time chaos synchronization secure communication system

    E-Print Network [OSTI]

    Gonzalo Alvarez; Fausto Montoya; Miguel Romera; Gerardo Pastor

    2003-11-21

    This paper describes the security weakness of a recently proposed secure communication method based on discrete-time chaos synchronization. We show that the security is compromised even without precise knowledge of the chaotic system used. We also make many suggestions to improve its security in future versions.

  18. ESC: Energy Synchronized Communication in Sustainable Sensor Networks

    E-Print Network [OSTI]

    He, Tian

    ESC: Energy Synchronized Communication in Sustainable Sensor Networks Yu Gu, Ting Zhu and Tian He Abstract--With advances in energy harvesting techniques, it is now feasible to build sustainable sensor of sustainable sensor networks is to effectively utilize a continuous stream of ambient energy. Instead

  19. Ultra-Low Power Time Synchronization Using Passive Radio Receivers

    E-Print Network [OSTI]

    Amir, Yair

    Ultra-Low Power Time Synchronization Using Passive Radio Receivers Yin Chen Qiang Wang Marcus Chang. In this pa- per, we present an inexpensive and ultra-low power ( of elapsed seconds. The universal time sig- nal receiver combines an off-the-shelf radio chip with an ultra-low

  20. Semantic Synchronization in a Persistent Object System Library

    E-Print Network [OSTI]

    Wolf, Alexander L.

    constraints on a database, and the database management system (DBMS) synchronizes concurrent transactions transactions. Most commonly, a DBMS uses a two-phase locking protocol to enforce serializability. Each transaction requests locks according to the protocol, and the DBMS evaluates each request for con ict

  1. Clock distribution and synchronization in large digital systems 

    E-Print Network [OSTI]

    Hung, Tzu-Chien

    1991-01-01

    of this thesis is to present the analysis and the design of a new clock disl, ribution and synchronization networks for large digital systems. B. State of Current Research With the advance of the VLSI era, there has been a growing interest in exploring...

  2. Communication using Synchronization of Chaos in Semiconductor Lasers with optoelectronic

    E-Print Network [OSTI]

    Illing, Lucas

    Communication using Synchronization of Chaos in Semiconductor Lasers with optoelectronic feedback S Science, University of California, San Diego, La Jolla, CA 93093-0402, USA Abstract. A communication of GHz chaotic signals. We then test a proposed communication scheme by successfully transmitting

  3. Using Stoppable Clocks to Safely Interface Asynchronous and Synchronous Subsystems

    E-Print Network [OSTI]

    Moore, Simon

    of pipeline and often require a clock which is rarely stopped. This is in contrast to circuits which clock a single synchronous pipeline stage each time there is new input stimuli [2] which are simple extensions is to stretch the clock when there is a risk of metastability [1, 8, 10]. Since the clock has to be pausable, we

  4. Combating Time Synchronization Attack: A Cross Layer Defense Mechanism

    E-Print Network [OSTI]

    Li, Husheng

    and Protection]: Physical Security 1. INTRODUCTION The security of smart grid has become an important research synchronization attack (TSA) on wide area monitoring systems in smart grid has been identified re- cently. A cross the eectiveness of the pro- posed TSA detection algorithm. Categories and Subject Descriptors K.6.5 [Security

  5. A Synchronization and Aggregate Communication Library for PAPERS Clusters

    E-Print Network [OSTI]

    Dietz, Henry G. "Hank"

    , the overriding concern in design and implementation of a public domain PAPERS support library has been to provide and the associated increases in latency. For this reason, the PAPERS library is based on the functionality of a veryA Synchronization and Aggregate Communication Library for PAPERS Clusters H. G. Dietz, T. M. Chung

  6. Synchronization Transitions in a Disordered Josephson Series Kurt Wiesenfeld

    E-Print Network [OSTI]

    Colet, Pere

    Synchronization Transitions in a Disordered Josephson Series Array Kurt Wiesenfeld School corresponds to complete phase­locking. In the limit of weak coupling and disorder, the system can be mapped with negligible capacitance, the governing circuit equations are ¯ h 2er j â?? OE j + I j sin OE j + â?? Q = I B ; j

  7. Emergence of nonuniform V-states by synchronization L. Friedland

    E-Print Network [OSTI]

    Friedland, Lazar

    Emergence of nonuniform V-states by synchronization L. Friedland Racah Institute of Physics, Hebrew nonuniform V-states can emerge in both free and bounded space by subjecting an axisymmetric vortex azimuthal symmetry. The cap- ture is followed by adiabatic deformation of the vortex boundary and emergence

  8. Copper laser modulator driving assembly including a magnetic compression laser

    DOE Patents [OSTI]

    Cook, Edward G. (Livermore, CA); Birx, Daniel L. (Oakley, CA); Ball, Don G. (Livermore, CA)

    1994-01-01

    A laser modulator (10) having a low voltage assembly (12) with a plurality of low voltage modules (14) with first stage magnetic compression circuits (20) and magnetic assist inductors (28) with a common core (91), such that timing of the first stage magnetic switches (30b) is thereby synchronized. A bipolar second stage of magnetic compression (42) is coupled to the low voltage modules (14) through a bipolar pulse transformer (36) and a third stage of magnetic compression (44) is directly coupled to the second stage of magnetic compression (42). The low voltage assembly (12) includes pressurized boxes (117) for improving voltage standoff between the primary winding assemblies (34) and secondary winding (40) contained therein.

  9. http://www.ecc.u-tokyo.ac.jp/doc/announce/newuser.html http://utroam.nc.u-tokyo.ac.jp/ [

    E-Print Network [OSTI]

    Goda, Keisuke

    OPAC TREEMyOPAC MyOPAC ()10 2 ECCS ECCS http://www.ecc.u-tokyo.ac.jp/doc/announce/newuser.html LAN LANutroam utroamECCS http://utroam.nc.u-tokyo.ac.jp/ [] ECCS http://www.dl.itc.u-tokyo.ac.jp/gacos/faq/gakugai.html http://www.dl.itc.u-tokyo.ac.jp/gacos/ http://www.dl.itc.u-tokyo.ac.jp/gacos/training.html https

  10. Energy cost reduction in the synchronization of a pair of nonidentical coupled Hindmarsh-Rose neurons

    E-Print Network [OSTI]

    A. Moujahid; A. D'Anjou; F. J. Torrealdea; C. Sarasola

    2012-04-17

    Many biological processes involve synchronization between nonequivalent systems, i.e, systems where the difference is limited to a rather small parameter mismatch. The maintenance of the synchronized regime in this cases is energetically costly \\cite{1}. This work studies the energy implications of synchronization phenomena in a pair of structurally flexible coupled neurons that interact through electrical coupling. We show that the forced synchronization between two nonidentical neurons creates appropriate conditions for an efficient actuation of adaptive laws able to make the neurons structurally approach their behaviours in order to decrease the flow of energy required to maintain the synchronization regime.

  11. Three phase AC motor controller

    DOE Patents [OSTI]

    Vuckovich, Michael (Elizabeth, PA); Wright, Maynard K. (Bethel Park, PA); Burkett, John P. (South Huntington Township, Westmoreland County, PA)

    1984-03-20

    A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

  12. jhchang@nova.snu.ac.kr {btzhang,ytkim}@cse.snu.ac.kr Helmholtz machine

    E-Print Network [OSTI]

    jhchang@nova.snu.ac.kr {btzhang,ytkim}@cse.snu.ac.kr Helmholtz machine . Helmholtz machine , . Helmholtz machine . , . (information gain) , Naïve Bayes . 1. (text categorization) . , . k- , Naïve Bayes, , support vector machine, PCA . , . . , . MCMC (Markov Chain Monte Carlo), Variational inference . Helmholtz

  13. Zigbee psy@netlab.snu.ac.kr, sbahk@snu.ac.kr

    E-Print Network [OSTI]

    Bahk, Saewoong

    2012 Zigbee , psy@netlab.snu.ac.kr, sbahk@snu.ac.kr Inter-protocol communication for energy efficient white space sensing of Zigbee device Se-Yong Park, Saewoong Bahk INMC, School of EECS, Seoul National University Zigbee WLAN , WLAN beacon preamble PHY

  14. 1066 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 51, NO. 5, OCTOBER 2004 Stator-Flux-Oriented Vector Control of Synchronous

    E-Print Network [OSTI]

    Sanders, Seth

    -mentioned advantages is a motor/generator for a flywheel energy storage system [4]. Vector control of synchronous-Flux-Oriented Vector Control of Synchronous Reluctance Machines With Maximized Efficiency Heath F. Hofmann, Member and rotational speed for a synchronous reluctance machine. A model of the synchronous reluctance machine

  15. 150 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 1, JANUARY 2004 Synchronous Mirror Delay for Multiphase Locking

    E-Print Network [OSTI]

    Lee, Jong Duk

    is fabricated using 0.13- m CMOS technology. To measure the synchronizing error of the clock generation circuit, many synchronous clock generation circuits in which internal signal synchronizes with external signal150 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 39, NO. 1, JANUARY 2004 Synchronous Mirror Delay

  16. Superconducting magnets

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

    This report discusses the following topics on superconducting magnets: D19B and -C: The next steps for a record-setting magnet; D20: The push beyond 10 T: Beyond D20: Speculations on the 16-T regime; other advanced magnets for accelerators; spinoff applications; APC materials development; cable and cabling-machine development; and high-{Tc} superconductor at low temperature.

  17. IEEE 802.11 PSM happy1024@cs.yonsei.ac.kr, kimthun@cs.yonsei.ac.kr, yang@cs.yonsei.ac.kr

    E-Print Network [OSTI]

    Yang, Sung-Bong

    2 P2P IEEE 802.11 PSM O, , happy1024@cs.yonsei.ac.kr, kimthun@cs.yonsei.ac.kr, yang@cs.yonsei.ac.kr An Effective Power Saving Mechanism for IEEE 802.11 PSM In Double-layered Mobile P2P Systems JuHee Lee, Taek IEEE 802.11 (PSM) . PSM Beacon Interval Sleep . , Sleep

  18. 3D modeling of magnetic atom traps on type-II superconductor chips

    E-Print Network [OSTI]

    Prigozhin, Leonid

    of Mathematics, Imperial College London, London SW7 2AZ, UK E-mail: sokolovv@bgu.ac.il, leonid September 2014 Published 12 November 2014 Abstract Magnetic traps for cold atoms have become a powerful tool depth, shape, distance from the chip surface, etc) that are necessary when designing magnetic traps

  19. On obliquely magnetized and differentially rotating stars

    E-Print Network [OSTI]

    Wei, Xing

    2015-01-01

    We investigate the interaction of differential rotation and a misaligned magnetic field. The incompressible magnetohydrodynamic equations are solved numerically for a free-decay problem. In the kinematic limit, differential rotation annihilates the non-axisymmetric field on a timescale proportional to the cube root of magnetic Reynolds number ($Rm$), as predicted by R\\"adler. Nonlinearly, the outcome depends upon the initial energy in the non-axisymmetric part of the field. Sufficiently weak fields approach axisymmetry as in the kinematic limit; some differential rotation survives across magnetic surfaces, at least on intermediate timescales. Stronger fields enforce uniform rotation and remain non-axisymmetric. The initial field strength that divides these two regimes does not follow the scaling $Rm^{-1/3}$ predicted by quasi-kinematic arguments, perhaps because our $Rm$ is never sufficiently large or because of reconnection. We discuss the possible relevance of these results to tidal synchronization and tida...

  20. Complex Dynamics and Synchronization of Delayed-Feedback Nonlinear Oscillators

    E-Print Network [OSTI]

    Thomas E. Murphy; Adam B. Cohen; Bhargava Ravoori; Karl R. B. Schmitt; Anurag V. Setty; Francesco Sorrentino; Caitlin R. S. Williams; Edward Ott; Rajarshi Roy

    2009-09-22

    We describe a flexible and modular delayed-feedback nonlinear oscillator that is capable of generating a wide range of dynamical behaviours, from periodic oscillations to high-dimensional chaos. The oscillator uses electrooptic modulation and fibre-optic transmission, with feedback and filtering implemented through real-time digital-signal processing. We consider two such oscillators that are coupled to one another, and we identify the conditions under which they will synchronize. By examining the rates of divergence or convergence between two coupled oscillators, we quantify the maximum Lyapunov exponents or transverse Lyapunov exponents of the system, and we present an experimental method to determine these rates that does not require a mathematical model of the system. Finally, we demonstrate a new adaptive control method that keeps two oscillators synchronized even when the coupling between them is changing unpredictably.

  1. Apparatus, system, and method for synchronizing a timer key

    DOE Patents [OSTI]

    Condit, Reston A; Daniels, Michael A; Clemens, Gregory P; Tomberlin, Eric S; Johnson, Joel A

    2014-04-22

    A timer key relating to monitoring a countdown time of a countdown routine of an electronic device is disclosed. The timer key comprises a processor configured to respond to a countdown time associated with operation of the electronic device, a display operably coupled with the processor, and a housing configured to house at least the processor. The housing has an associated structure configured to engage with the electronic device to share the countdown time between the electronic device and the timer key. The processor is configured to begin a countdown routine based at least in part on the countdown time, wherein the countdown routine is at least substantially synchronized with a countdown routine of the electronic device when the timer key is removed from the electronic device. A system and method for synchronizing countdown routines of a timer key and an electronic device are also disclosed.

  2. Synchronization of Networked Jahn-Teller Systems in Circuit QED

    E-Print Network [OSTI]

    Yusuf Gul

    2015-08-05

    We consider the nonlinear effects in Jahn-Teller system of two coupled resonators interacting simultaneously with flux qubit using Circuit QED. Two frequency description of Jahn Teller system that inherits the networked structure of both nonlinear Josephson Junctions and harmonic oscillators is employed to describe the synchronous structures in multifrequency scheme. Emergence of dominating mode is investigated to analyze frequency locking by eigenvalue spectrum. Rabi Supersplitting is tuned for coupled and uncoupled synchronous con?gurations in terms of frequency entrainment switched by coupling strength between resonators. Second order coherence functions are employed to investigate self-sustained oscillations in resonator mode and qubit dephasing. Snychronous structure between correlations of priviledged mode and qubit is obtained in localization-delocalization and photon blockade regime controlled by the population imbalance.

  3. Optical synchronization system for femtosecond X-ray sources

    DOE Patents [OSTI]

    Wilcox, Russell B. (El Cerrito, CA); Holzwarth, Ronald (Munich, DE)

    2011-12-13

    Femtosecond pump/probe experiments using short X-Ray and optical pulses require precise synchronization between 100 meter-10 km separated lasers in a various experiments. For stabilization in the hundred femtosecond range a CW laser is amplitude modulated at 1-10 GHz, the signal retroreflected from the far end, and the relative phase used to correct the transit time with various implementations. For the sub-10 fsec range the laser frequency itself is upshifted 55 MHz with an acousto-optical modulator, retroreflected, upshifted again and phase compared at the sending end to a 110 MHz reference. Initial experiments indicate less than 1 fsec timing jitter. To lock lasers in the sub-10 fs range two single-frequency lasers separated by several teraHertz will be lock to a master modelocked fiber laser, transmit the two frequencies over fiber, and lock two comb lines of a slave laser to these frequencies, thus synchronizing the two modelocked laser envelopes.

  4. Comparative analysis of existing models for power-grid synchronization

    E-Print Network [OSTI]

    Nishikawa, Takashi

    2015-01-01

    The dynamics of power-grid networks is becoming an increasingly active area of research within the physics and network science communities. The results from such studies are typically insightful and illustrative, but are often based on simplifying assumptions that can be either difficult to assess or not fully justified for realistic applications. Here we perform a comprehensive comparative analysis of three leading models recently used to study synchronization dynamics in power-grid networks -- a fundamental problem of practical significance given that frequency synchronization of all power generators in the same interconnection is a necessary condition for a power grid to operate. We show that each of these models can be derived from first principles within a common framework based on the classical model of a generator, thereby clarifying all assumptions involved. This framework allows us to view power grids as complex networks of coupled second-order phase oscillators with both forcing and damping terms. U...

  5. Spontaneous synchronization driven by energy transport in interconnected networks

    E-Print Network [OSTI]

    Vincenzo Nicosia; Per Sebastian Skardal; Vito Latora; Alex Arenas

    2015-02-26

    Understanding dynamical processes on networks is an important area of research in complex systems, with far reaching implications and applications in many real-world cases. Here we introduce and study a model of intertwined dynamics on interconnected networks, inspired by the human brain, which consists of bidirectionally coupled synchronization and energy transport processes. Remarkably, the proposed model allows the emergence of spontaneous switch-like synchronization transitions driven by the energy transport dynamics, which qualitatively mirror the transitions observed in human brain dynamics between resting-state and cognitive activity. We provide a steady-state analytical explanation for the observed behavior and show that the switch-like transition is robust over a wide range of model parameters and network topologies. Finally, we suggest that the complexity inherent in other interconnected dynamical processes might be responsible for various other emergent behaviors observed in natural systems.

  6. A 40 mm Bore Quadrupole Magnet for the SSC

    E-Print Network [OSTI]

    Taylor, C.E.

    2011-01-01

    No. DE-AC03-76SF00098. A 40 MM BORE QUADRUPOLE MAGNET FOR40mm 211 T/m+ 5.0m 1664 ( both rings) 6500A 0.648 mm9.78 mm 1.062/1.268 mm 1.2 deg. Coil bore diameter Gradient

  7. Digital-data receiver synchronization method and apparatus

    DOE Patents [OSTI]

    Smith, Stephen F. (Loudon, TN) [Loudon, TN; Turner, Gary W. (Clinton, TN) [Clinton, TN

    2009-09-08

    Digital data receiver synchronization is provided with composite phase-frequency detectors, mutually cross-connected comparison feedback or both to provide robust reception of digital data signals. A single master clock can be used to provide frequency signals. Advantages can include fast lock-up time in moderately to severely noisy conditions, greater tolerance to noise and jitter when locked, and improved tolerance to clock asymmetries.

  8. Digital-data receiver synchronization method and apparatus

    DOE Patents [OSTI]

    Smith, Stephen F.; Turner, Gary W.

    2005-12-06

    Digital-data receiver synchronization is provided with composite phase-frequency detectors, mutually cross-connected comparison feedback or both to provide robust reception of digital data signals. A single master clock may be used to provide frequency signals. Advantages can include fast lock-up time in moderately to severely noisy conditions, greater tolerance to noise and jitter when locked, and improved tolerance to clock asymmetries.

  9. Complex network synchronization of chaotic systems with delay coupling

    SciTech Connect (OSTI)

    Theesar, S. Jeeva Sathya, E-mail: sjstheesar@gmail.com; Ratnavelu, K., E-mail: sjstheesar@gmail.com [Network Science Research Group, Institute of Mathematical Sciences, University of Malaya, 50603, Kuala Lumpur (Malaysia)

    2014-03-05

    The study of complex networks enables us to understand the collective behavior of the interconnected elements and provides vast real time applications from biology to laser dynamics. In this paper, synchronization of complex network of chaotic systems has been studied. Every identical node in the complex network is assumed to be in Lur’e system form. In particular, delayed coupling has been assumed along with identical sector bounded nonlinear systems which are interconnected over network topology.

  10. Laser synchronized high-speed shutter for spectroscopic application

    DOE Patents [OSTI]

    Miles, Paul C. (Tracy, CA); Porter, Eldon L. (Tracy, CA); Prast, Thomas L. (Livermore, CA); Sunnarborg, Duane A. (Livermore, CA)

    2002-01-01

    A fast mechanical shutter, based on rotating chopper wheels, has been designed and implemented to shutter the entrance slit of a spectrograph. This device enables an exposure time of 9 .mu.s to be achieved for a 0.8 mm wide spectrograph entrance slit, achieves 100% transmission in the open state, and an essentially infinite extinction ratio. The device further incorporates chopper wheel position sensing electronics to permit the synchronous triggering of a laser source.

  11. From synchronization to multistability in two coupled quadratic maps

    E-Print Network [OSTI]

    Rui Carvalho; Bastien Fernandez; R. Vilela Mendes

    2000-05-26

    The phenomenology of a system of two coupled quadratic maps is studied both analytically and numerically. Conditions for synchronization are given and the bifurcations of periodic orbits from this regime are identified. In addition, we show that an arbitrarily large number of distinct stable periodic orbits may be obtained when the maps parameter is at the Feigenbaum period-doubling accumulation point. An estimate is given for the coupling strength needed to obtain any given number of stable orbits.

  12. High fidelity ac gate operations of the quantum dot hybrid qubit

    E-Print Network [OSTI]

    Clement H. Wong

    2015-10-20

    Semiconductor quantum dots in silicon are promising qubits because of long spin coherence times and their potential for scalability. However, such qubits with complete electrical control and fidelities above the threshold for quantum error correction have not yet been achieved. We show theoretically that the threshold fidelity can be achieved with ac gate operation of the quantum dot hybrid qubit. Formed by three electrons in a double dot, this qubit is electrically controlled, does not require magnetic fields, and runs at GHz gate speeds. We analyze the decoherence caused by 1/f charge noise in this qubit, find parameters that minimize the charge noise dependence in the qubit frequency, and determine the optimal working points for ac gate operations that drive the detuning and tunnel coupling.

  13. Magnetic properties of double perovskite La2BMnO6 (B = Ni or Co) nanoparticles

    SciTech Connect (OSTI)

    Mao, Yuanbing; Parsons, Jason; McCloy, John S.

    2013-03-31

    Double perovskite La2BMnO6 (B = Ni and Co) nanoparticles with average particle size of ~50 nm were synthesized using a facile, environmentally friendly, scalable molten-salt reaction at 700 °C in air. Their structural and morphological properties were characterized by x-ray diffraction and transmission electron microscopy. Magnetic properties were evaluated using dc magnetic M-T and M-H, and ac magnetic susceptibility versus frequency, temperature, and field. The magnetization curve shows a paramagnetic-ferromagnetic transition at TC ~275 and 220 K for La2NiMnO6 (LNMO) and La2CoMnO6 (LCMO) nanoparticles, respectively. ac susceptibility revealed that the LCMO had a single magnetic transition indicative of Co2+-O2--Mn4+ ordering, whereas the LNMO showed more complex magnetic behavior suggesting a re-entrant spin glass.

  14. Cell body rocking is a dominant mechanism for flagellar synchronization in a swimming algae

    E-Print Network [OSTI]

    Geyer, Veikko; Howard, Jonathon; Friedrich, Benjamin M

    2013-01-01

    The unicellular green algae Chlamydomonas swims with two flagella, which can synchronize their beat. Synchronized beating is required to swim both fast and straight. A long-standing hypothesis proposes that synchronization of flagella results from hydrodynamic coupling, but the details are not understood. Here, we present realistic hydrodynamic computations and high-speed tracking experiments of swimming cells that show how a perturbation from the synchronized state causes rotational motion of the cell body. This rotation feeds back on the flagellar dynamics via hydrodynamic friction forces and rapidly restores the synchronized state in our theory. We calculate that this `cell body rocking' provides the dominant contribution to synchronization in swimming cells, whereas direct hydrodynamic interactions between the flagella contribute negligibly. We experimentally confirmed the coupling between flagellar beating and cell body rocking predicted by our theory. We propose that the interplay of flagellar beating a...

  15. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, J.A.; Stone, R.R.; Fabyan, J.

    1987-10-06

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines. 3 figs.

  16. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, John A. (Livermore, CA); Stone, Roger R. (Walnut Creek, CA); Fabyan, Joseph (Livermore, CA)

    1987-01-01

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  17. EXPERIMENTAL STUDY OF ELECTROLYTE DEPENDENCE OF AC ELECTROOSMOTIC PUMPS

    E-Print Network [OSTI]

    Bazant, Martin Z.

    EXPERIMENTAL STUDY OF ELECTROLYTE DEPENDENCE OF AC ELECTROOSMOTIC PUMPS Kapil Subramanian1 , John Abstract: Recent studies indicate increased efficiency of microfluidic ac electro-osmotic pumps of ac electroosmosis in microchannels on solution chemistry for the new fast aceo stepped pumps

  18. When tensor products of AC charges and Radon

    E-Print Network [OSTI]

    Buczolich, Zoltán

    When tensor products of AC #3; charges and Radon measures are AC #3; charges Zolt#19;an Buczolich and Radon measures. We show that if F is a charge in R m which is AC#3; in a locally BV set E and #22; is an absolutely continuous Radon measure on R n with locally bounded Radon-Nikodym derivative then the charge F

  19. Undergraduate study 2016 www.nottingham.ac.uk/geography

    E-Print Network [OSTI]

    Nottingham, University of

    Geography Undergraduate study 2016 www.nottingham.ac.uk/geography For general undergraduate-enquiries@nottingham.ac.uk w: www.nottingham.ac.uk/faqs #12;The School of Geography at The University of Nottingham. As a Nottingham geography graduate you will have outstanding career prospects based on your specialist knowledge

  20. STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE

    E-Print Network [OSTI]

    STATE OF CALIFORNIA DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION CERTIFICATE OF ACCEPTANCE MECH-14A NA7.5.13 Distributed Energy Storage DX AC DISTRIBUTED ENERGY STORAGE DX AC SYSTEMES ACCEPTANCE CEC-MECH-14A (Revised 08/09) CALIFORNIA ENERGY COMMISSION

  1. Synchronized Independent Narrow-band Single Photons and Efficient Generation of Photonic Entanglement

    E-Print Network [OSTI]

    Zhen-Sheng Yuan; Yu-Ao Chen; Shuai Chen; Bo Zhao; Markus Koch; Thorsten Strassel; Yong Zhao; Gan-Jun Zhu; Jörg Schmiedmayer; Jian-Wei Pan

    2007-05-05

    We create independent, synchronized single-photon sources with built-in quantum memory based on two remote cold atomic ensembles. The synchronized single photons are used to demonstrate efficient generation of entanglement. The resulting entangled photon pairs violate a Bell's Inequality by 5 standard deviations. Our synchronized single photons with their long coherence time of 25 ns and the efficient creation of entanglement serve as an ideal building block for scalable linear optical quantum information processing.

  2. Validity of numerical trajectories in the synchronization transition of complex systems

    E-Print Network [OSTI]

    R. L. Viana; C. Grebogi; S. E. de S. Pinto; S. R. Lopes; A. M. Batista; J. Kurths

    2003-10-07

    We investigate the relationship between the loss of synchronization and the onset of shadowing breakdown {\\it via} unstable dimension variability in complex systems. In the neighborhood of the critical transition to strongly non-hyperbolic behavior, the system undergoes on-off intermittency with respect to the synchronization state. There are potentially severe consequences of these facts on the validity of the computer-generated trajectories obtained from dynamical systems whose synchronization manifolds share the same non-hyperbolic properties.

  3. Zero Lag Synchronization of Mutually Coupled Lasers in the Presence of Delays

    E-Print Network [OSTI]

    Alexandra S. Landsman; Leah B. Shaw; Ira B. Schwartz

    2007-11-05

    We consider a line of three mutually coupled lasers with time delays and study chaotic synchronization of the outer lasers. Two different systems are presented: optoelectronically coupled semiconductor lasers and optically coupled fiber lasers. While the dynamics of the two systems are very different, robust synchronization of end lasers is obtained in both cases over a range of parameters. Here, we present analysis and numerical simulation to explain some of the observed synchronization phenomena. First, we introduce the system of three coupled semiconductor lasers and discuss the onset of oscillations that occurs via a bifurcation as the coupling strength increases. Next, we analyze the synchronization of the end lasers by examining the dynamics transverse to synchronized state. We prove that chaotic synchronization of the outer semiconductor lasers will occur for sufficiently long delays, and we make a comparison to generalized synchronization in driven dissipative systems. It is shown that the stability of synchronous state (as indicated by negative Lyupunov exponents transverse to the synchronization manifold) depends on the internal dissipation of the outer lasers. We next present numerical simulations for three coupled fiber lasers, highlighting some of the differences between the semiconductor and fiber laser systems. Due to the large number of coupled modes in fiber lasers, this is a good system for investigating spatio-temporal chaos. Stochastic noise is included in the fiber laser model, and synchrony of the outer lasers is observed even at very small coupling strengths.

  4. LOLA: Runtime Monitoring of Synchronous Ben D'Angelo # Sriram Sankaranarayanan # Cesar Sanchez # Will Robinson #

    E-Print Network [OSTI]

    Sánchez, César

    LOLA: Runtime Monitoring of Synchronous Systems Ben D'Angelo # Sriram Sankaranarayanan # Câ??esar S Department, Stanford University, Stanford, CA 94305 {bdangelo,srirams

  5. LOLA: Runtime Monitoring of Synchronous Ben D'Angelo Sriram Sankaranarayanan Cesar Sanchez Will Robinson

    E-Print Network [OSTI]

    Sánchez, César

    LOLA: Runtime Monitoring of Synchronous Systems Ben D'Angelo Sriram Sankaranarayanan C´esar S, Stanford University, Stanford, CA 94305 {bdangelo,srirams

  6. Trade-offs and Issues in Traffic Synchronization Claus Gwiggner, Masato Fujita,

    E-Print Network [OSTI]

    Gwiggner, Claus Peter

    The International Civil Aviation Organization (ICAO) pro- poses several components of a modern ATM system is called `Traffic Synchronization'. It is described as the `tactical establishment and maintenance

  7. Isochronal synchronization of delay-coupled systems Ira B. Schwartz and Leah B. Shaw

    E-Print Network [OSTI]

    Shaw, Leah B.

    isochronally synchronized. Applications are shown for both incoherent pump-coupled lasers and spatiotemporal is found in coupled semiconductor lasers 10 . Cross- correlation statistics between the two intensities

  8. Emergence and control of breather and plasma oscillations by synchronizing perturbations L. Friedland

    E-Print Network [OSTI]

    Friedland, Lazar

    Emergence and control of breather and plasma oscillations by synchronizing perturbations L frequency standing wave, while emergence of autoresonant breather oscillations requires driving

  9. Magnetic shielding

    DOE Patents [OSTI]

    Kerns, J.A.; Stone, R.R.; Fabyan, J.

    1985-02-12

    A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.

  10. Magnetic nanotubes

    DOE Patents [OSTI]

    Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)

    2010-11-16

    A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.

  11. Sensorless Speed Control of Permanent Magnet-Assisted Synchronous Reluctance Motor (PMa-SynRM) 

    E-Print Network [OSTI]

    Chakali, Anil K.

    2011-02-22

    for their help, particularly Robert Vartanian, Jeihoon Baek, Behrooz Nikbakhtan, Nicholas Frank, Suengdeog Choi, Mashid Amirabadi, Mehran Mirjafari, Vivek Sundaram, Anand Balakrishnan, Yateendra Deshpande, Dr. Salman Talebi and Dr. Baris Ozturk. Finally, I...

  12. Direct torque control of permanent magnet synchronous motors with non-sinusoidal back-EMF 

    E-Print Network [OSTI]

    Ozturk, Salih Baris

    2009-05-15

    This work presents the direct torque control (DTC) techniques, implemented in four- and six-switch inverter, for brushless dc (BLDC) motors with non-sinusoidal back- EMF using two and three-phase conduction modes. First of all, the classical direct...

  13. ANALYSIS OF THE PERFORMANCE AND COST EFFECTIVENESS OF NINE SMALL WIND ENERGY CONVERSION SYSTEMS FUNDED BY THE DOE SMALL GRANTS PROGRAM

    E-Print Network [OSTI]

    Kay, J.

    2009-01-01

    swivel tail & 3-phase synchronous generator) 8 kW Windworkssynchronous inverter Addition: 3-phase induction generatorsynchronous permanent of PGI, originally intended to use a three phase magnet AC generator

  14. Synchronization and Collective Dynamics in a Carpet of Microfluidic Rotors

    E-Print Network [OSTI]

    Nariya Uchida; Ramin Golestanian

    2010-04-28

    We study synchronization of an array of rotors on a substrate that are coupled by hydrodynamic interaction. The rotors that are modeled by an effective rigid body, are driven by an internal torque and exerts an active force on the surrounding fluid. The long-ranged nature of the hydrodynamic interaction between the rotors causes a rich pattern of dynamical behaviors including phase ordering and turbulent spiral waves. The model provides a novel example of coupled oscillators with long-range interaction. Our results suggest strategies for designing controllable microfluidic mixers using the emergent behavior of hydrodynamically coupled active components.

  15. Using Synchronization for Prediction of High-Dimensional Chaotic Dynamics

    E-Print Network [OSTI]

    Adam B. Cohen; Bhargava Ravoori; Thomas E. Murphy; Rajarshi Roy

    2008-09-22

    We experimentally observe the nonlinear dynamics of an optoelectronic time-delayed feedback loop designed for chaotic communication using commercial fiber optic links, and we simulate the system using delay differential equations. We show that synchronization of a numerical model to experimental measurements provides a new way to assimilate data and forecast the future of this time-delayed high-dimensional system. For this system, which has a feedback time delay of 22 ns, we show that one can predict the time series for up to several delay periods, when the dynamics is about 15 dimensional.

  16. Global synchronization of parallel processors using clock pulse width modulation

    DOE Patents [OSTI]

    Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  17. 16,000-rpm Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation

    SciTech Connect (OSTI)

    Hsu, J.S.; Burress, T.A.; Lee, S.T.; Wiles, R.H.; Coomer, C.L.; McKeever, J.W.; Adams, D.J.

    2007-10-31

    The reluctance interior permanent magnet (RIPM) motor is currently used by many leading auto manufacturers for hybrid vehicles. The power density for this type of motor is high compared with that of induction motors and switched reluctance motors. The primary drawback of the RIPM motor is the permanent magnet (PM) because during high-speed operation, the fixed PM produces a huge back electromotive force (emf) that must be reduced before the current will pass through the stator windings. This reduction in back-emf is accomplished with a significant direct-axis (d-axis) demagnetization current, which opposes the PM's flux to reduce the flux seen by the stator wires. This may lower the power factor and efficiency of the motor and raise the requirement on the alternate current (ac) power supply; consequently, bigger inverter switching components, thicker motor winding conductors, and heavier cables are required. The direct current (dc) link capacitor is also affected when it must accommodate heavier harmonic currents. It is commonly agreed that, for synchronous machines, the power factor can be optimized by varying the field excitation to minimize the current. The field produced by the PM is fixed and cannot be adjusted. What can be adjusted is reactive current to the d-axis of the stator winding, which consumes reactive power but does not always help to improve the power factor. The objective of this project is to avoid the primary drawbacks of the RIPM motor by introducing brushless field excitation (BFE). This offers both high torque per ampere (A) per core length at low speed by using flux, which is enhanced by increasing current to a fixed excitation coil, and flux, which is weakened at high speed by reducing current to the excitation coil. If field weakening is used, the dc/dc boost converter used in a conventional RIPM motor may be eliminated to reduce system costs. However, BFE supports a drive system with a dc/dc boost converter, because it can further extend the constant power speed range of the drive system and adjust the field for power factor and efficiency gains. Lower core losses at low torque regions, especially at high speeds, are attained by reducing the field excitation. Safety and reliability are increased by weakening the field when a winding short-circuit fault occurs, preventing damage to the motor. For a high-speed motor operating at 16,000-revolutions per minute (rpm), mechanical stress is a challenge. Bridges that link the rotor punching segments together must be thickened for mechanical integrity; consequently, increased rotor flux leakage significantly lowers motor performance. This barrier can be overcome by BFE to ensure sufficient rotor flux when needed.

  18. Forced libration of tidally synchronized planets and moons

    E-Print Network [OSTI]

    Makarov, Valeri V; Dorland, Bryan

    2015-01-01

    Tidal dissipation of kinetic energy, when it is strong enough, tends to synchronize the rotation of planets and moons with the mean orbital motion, or drive it into long-term stable spin-orbit resonances. As the orbital motion undergoes periodic acceleration due to a finite orbital eccentricity, the spin rate oscillates around the equilibrium mean value too, giving rise to the forced, or eccentricity-driven, librations. Both the shape and amplitude of forced librations of synchronous viscoelastic planets and moons are defined by a combination of two different types of perturbative torque, the tidal torque and the triaxial torque. Consequently, forced librations can be tidally dominated (e.g., Io and possibly Titan) or deformation-dominated (e.g., the Moon) depending on a set of orbital, rheological, and other physical parameters. With small eccentricities, for the former kind, the largest term in the libration angle can be minus cosine of the mean anomaly, whereas for the latter kind, it is minus sine of the ...

  19. Intermittent synchronization in a network of bursting neurons

    E-Print Network [OSTI]

    Choongseok Park; Leonid L. Rubchinsky

    2011-09-12

    Synchronized oscillations in networks of inhibitory and excitatory coupled bursting neurons are common in a variety of neural systems from central pattern generators to human brain circuits. One example of the latter is the subcortical network of the basal ganglia, formed by excitatory and inhibitory bursters of the subthalamic nucleus and globus pallidus, involved in motor control and affected in Parkinson's disease. Recent experiments have demonstrated the intermittent nature of the phase-locking of neural activity in this network. Here we explore one potential mechanism to explain the intermittent phase-locking in a network. We simplify the network to obtain a model of two inhibitory coupled elements and explore its dynamics. We used geometric analysis and singular perturbation methods for dynamical systems to reduce the full model to a simpler set of equations. Mathematical analysis was completed using three slow variables with two different time scales. Intermittently synchronous oscillations are generated by overlapped spiking which crucially depends on the geometry of the slow phase plane and the interplay between slow variables as well as the strength of synapses. Two slow variables are responsible for the generation of activity patterns with overlapped spiking and the other slower variable enhances the robustness of an irregular and intermittent activity pattern. While the analyzed network and the explored mechanism of intermittent synchrony appear to be quite generic, the results of this analysis can be used to trace particular values of biophysical parameters (synaptic strength and parameters of calcium dynamics), which are known to be impacted in Parkinson's disease.

  20. Flexible-Bandwidth Power-Aware Optical Interconnects with Source Synchronous Technique

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    @ucdavis.edu, sbyoo@ucdavis.edu Abstract: This paper investigates energy savings in data centers with flexible-bandwidth power- aware source-synchronous optical interconnects. Network simulations show 5× energy savings. Link-PA source synchronous link and investigate the energy saving for a fat-tree network. Finally we report

  1. Balanced optical-microwave phase detector for sub-femtosecond optical-RF synchronization

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

    Peng, Michael Y.; Kalaydzhyan, Aram; Kärtner, Franz X.

    2014-10-23

    We demonstrate that balanced optical-microwave phase detectors (BOMPD) are capable of optical-RF synchronization with sub-femtosecond residual timing jitter for large-scale timing distribution systems. RF-to-optical synchronization is achieved with a long-term stability of more »suppression ratio with potential improvement via DC offset adjustment.« less

  2. Synchronous Dependency Insertion Grammars A Grammar Formalism for Syntax Based Statistical MT

    E-Print Network [OSTI]

    Synchronous Dependency Insertion Grammars A Grammar Formalism for Syntax Based Statistical MT Yuan formalism specifically designed for syntax-based sta- tistical machine translation. The synchro- nous between lan- guages, which many other synchronous grammars are unable to model. A Depend- ency Insertion

  3. WizSync: Exploiting Wi-Fi Infrastructure for Clock Synchronization in Wireless Sensor Networks

    E-Print Network [OSTI]

    Xing, Guoliang

    synchronization approach by exploiting the existing Wi-Fi infrastructure. Our approach leverages the fact that ZigBee unlicensed spectrum. As a result, a ZigBee node can detect and synchronize to the periodic beacons standards such as Bluetooth and 802.15.4/ZigBee, which also adopt the 2.4 GHz unlicensed spectrum

  4. Fundamental Limits on Secure Clock Synchronization and Man-In-The-Middle Detection

    E-Print Network [OSTI]

    be built, including routing protocols and more sophisticated heavyweight protocols. I. INTRODUCTION to conserve power. If synchronization is lost or tampered with in such systems, nodes may waste power waking up and transmitting at times when other nodes are asleep. Thus, secure clock synchronization

  5. Phase clustering and transition to phase synchronization in a large number of coupled nonlinear oscillators

    E-Print Network [OSTI]

    Lai, Ying-Cheng

    Phase clustering and transition to phase synchronization in a large number of coupled nonlinear received 22 November 2000; published 9 April 2001 The transition to phase synchronization in systems of average frequency marks the disappearance of one phase cluster 7 . In this Rapid Com- munication, we

  6. Investigation of Non-synchronous Vibration Mechanism for a High Speed Axial Compressor Using Delayed DES

    E-Print Network [OSTI]

    Zha, Gecheng

    Investigation of Non-synchronous Vibration Mechanism for a High Speed Axial Compressor Using compressor. DDES is a hybrid model for turbulence simulation, which uses RANS model within the wall boundary a torsion moment causing NSV. 1 Introduction Non-synchronous vibration of axial fan/compressor is a non

  7. Real-Time Synchronization on Multiprocessors: To Block or Not to Block, to Suspend or Spin?

    E-Print Network [OSTI]

    Anderson, James

    of several multiprocessor real-time synchronization options; this study is directed at previously- proposed knowledge, the real-time synchronization options considered herein have never been empirically compared before on an actual testbed. Before continuing, let us examine the options available for real

  8. Data Synchronization Issues in GALS SoCs Rostislav (Reuven) Dobkin1

    E-Print Network [OSTI]

    Ginosar, Ran

    ][5][6][7]. According to this methodology, a local ring-oscillator based clock generator in each synchronous "island1 Data Synchronization Issues in GALS SoCs Rostislav (Reuven) Dobkin1 , Ran Ginosar1 and Christos P ICS-FORTH, Crete, Greece Abstract: Locally generated, arbitrated clocks for GALS SoCs [1] face

  9. Synchronous Rhythms in a Model for the Indirect Pathway of the Basal Ganglia

    E-Print Network [OSTI]

    Synchronous Rhythms in a Model for the Indirect Pathway of the Basal Ganglia September 15, 2000 D and the subthalamic nucleus in the basal ganglia, we test hypotheses on the origin of tremor-related synchronous activity in parkinsonian states. We #12;nd that in a \\parkinsonian" regime, the network robustly generates

  10. SAME 2001, November 15 th 2001 1 A combinatorial logic block of a synchronous

    E-Print Network [OSTI]

    Huss, Sorin A.

    together with the generation of a request signal derived from a clock of the synchronous systemSAME 2001, November 15 th 2001 1 Abstract A combinatorial logic block of a synchronous pipeline uses pulsed signals, into a synronous environment with static signals. Therefore the generation

  11. Synchronization of Identical Oscillators Coupled through a Symmetric Network with Dynamics: A

    E-Print Network [OSTI]

    Hespanha, João Pedro

    on parallel operation of power inverters, specifically in the contexts of Uninterruptible Power Supplies (UPS algorithms for the parallel operation of power inverters. Simulation results have shown that synchronization Terms--Synchronization, coupled oscillators, LTI net- work, voltage power supplies. I. INTRODUCTION

  12. AN ONLINE SYSTEM FOR SYNCHRONIZED PROCESSING OF VIDEO AND AUDIO SIGNALS

    E-Print Network [OSTI]

    Amer, Aishy

    AN ONLINE SYSTEM FOR SYNCHRONIZED PROCESSING OF VIDEO AND AUDIO SIGNALS Mary Mikhail Giovanni and processed sepa- rately. The signals are buffered and integrated and synchro- nized using a time processing, audio processing, signals integration, synchronized audio and video signals; time- stamping. 1

  13. A Comparative Study of State Saving Mechanisms for Time Warp Synchronized Parallel Discrete Event Simulation

    E-Print Network [OSTI]

    Boyer, Edmond

    A Comparative Study of State Saving Mechanisms for Time Warp Synchronized Parallel Discrete Event of Technology SWEDEN Abstract The state saving mechanism constitutes an essential part of any system in which Synchronization mechanism. In this type of systems the state saving and restoration mechanism is essential

  14. Magnetic monopoles

    SciTech Connect (OSTI)

    Fryberger, D.

    1984-12-01

    In this talk on magnetic monopoles, first the author briefly reviews some historical background; then, the author describes what several different types of monopoles might look like; and finally the author discusses the experimental situation. 81 references.

  15. Chaos synchronization of the master-slave generalized Lorenz systems via linear state error feedback control

    E-Print Network [OSTI]

    Xiaofeng Wu; Guanrong Chen; Jianping Cai

    2008-07-14

    This paper provides a unified method for analyzing chaos synchronization of the generalized Lorenz systems. The considered synchronization scheme consists of identical master and slave generalized Lorenz systems coupled by linear state error variables. A sufficient synchronization criterion for a general linear state error feedback controller is rigorously proven by means of linearization and Lyapunov's direct methods. When a simple linear controller is used in the scheme, some easily implemented algebraic synchronization conditions are derived based on the upper and lower bounds of the master chaotic system. These criteria are further optimized to improve their sharpness. The optimized criteria are then applied to four typical generalized Lorenz systems, i.e. the classical Lorenz system, the Chen system, the Lv system and a unified chaotic system, obtaining precise corresponding synchronization conditions. The advantages of the new criteria are revealed by analytically and numerically comparing their sharpness with that of the known criteria existing in the literature.

  16. Synchronization of Fractional-order Chaotic Systems with Gaussian fluctuation by Sliding Mode Control

    E-Print Network [OSTI]

    Yong Xu; Hua Wang

    2013-09-04

    This paper is devoted to the problem of synchronization between fractional-order chaotic systems with Gaussian fluctuation by the method of fractional-order sliding mode control. A fractional integral (FI) sliding surface is proposed for synchronizing the uncertain fractional-order system, and then the sliding mode control technique is carried out to realize the synchronization of the given systems. One theorem about sliding mode controller is presented to prove the proposed controller can make the system synchronize. As a case study, the presented method is applied to the fractional-order Chen-L\\"u system as the drive-response dynamical system. Simulation results show a good performance of the proposed control approach in synchronizing the chaotic systems in presence of Gaussian noise.

  17. Magnetostrictive materials and method for improving AC characteristics in same

    DOE Patents [OSTI]

    Pulvirenti, Patricia P. (Chicago, IL); Jiles, David C. (Ames, IA)

    2001-08-14

    The present invention provides Terfenol-D alloys ("doped" Terfenol) having optimized performances under the condition of time-dependent magnetic fields. In one embodiment, performance is optimized by lowering the conductivity of Terfenol, thereby improving the frequency response. This can be achieved through addition of Group III or IV elements, such as Si and Al. Addition of these types of elements provides scattering sites for conduction electrons, thereby increasing resistivity by 125% which leads to an average increase in penetration depth of 80% at 1 kHz and an increase in energy conversion efficiency of 55%. The permeability of doped Terfenol remains constant over a wider frequency range as compared with undoped Terfenol. These results demonstrate that adding impurities, such as Si and Al, are effective in improving the ac characteristics of Terfenol. A magnetoelastic Gruneisen parameter, .gamma..sub.me, has also been derived from the thermodynamic equations of state, and provides another means by which to characterize the coupling efficiency in magnetostrictive materials on a more fundamental basis.

  18. 0-7803-8808-9/05/$20.00 2005 IEEE Time Synchronization for ZigBee Networks

    E-Print Network [OSTI]

    Milenkovi, Aleksandar

    0-7803-8808-9/05/$20.00 ©2005 IEEE Time Synchronization for ZigBee Networks Dennis Cox, Emil, ZigBee. Abstract--Time synchronization is essential for most network applications. It is particularly synchronization of mesh-connected wireless sensor networks. However, ZigBee can also accommodate master

  19. Abstract--Estimating the dynamic state variables of a synchronous generator has been a long standing research

    E-Print Network [OSTI]

    Venkatasubramanian, Mani V.

    Abstract-- Estimating the dynamic state variables of a synchronous generator has been a long approximately the state variables of a synchronous generator, purely from terminal measurements measurements. Here, we deal with the problem of computing the dynamic internal state of a synchronous generator

  20. r XXXX American Chemical Society A dx.doi.org/10.1021/ac102566f |Anal. Chem. XXXX, XXX, 000000 pubs.acs.org/ac

    E-Print Network [OSTI]

    Bashir, Rashid

    to such methods because it is a noncontact method of heating using microwave energy that is delivered directly­000 ARTICLE pubs.acs.org/ac Silicon Field Effect Transistors as Dual-Use Sensor-Heater Hybrids Bobby Reddy, Jr demonstrate the temperature mediated applications of a previously proposed novel localized dielectric heating

  1. 6/26/12 ACS Applied Materials & Interfaces: Most Read Articles (ACS Publications) 1/3pubs.acs.org/action/showMostReadArticles?journalCode=aamick

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    .org/action/showMostReadArticles?journalCode=aamick Advertisements Info for Advertisers Browse By Issue Select Decade Select Volume Select Issue Advertisements Info. Sreekumaran Nair, Peng Shengjie, Yang Shengyuan, and Seeram Ramakrishna Synthesis of Natural Cellulose Legacy Archives ACS Mobile Video User Resources About Us ACS Members Librarians Authors & Reviewers

  2. Synchronization in dynamical networks with unconstrained structure switching

    E-Print Network [OSTI]

    Charo I. del Genio; Miguel Romance; Regino Criado; Stefano Boccaletti

    2015-04-27

    We provide a rigorous solution to the problem of constructing a structural evolution for a network of coupled identical dynamical units that switches between specified topologies without constraints on their structure. The evolution of the structure is determined indirectly, from a carefully built transformation of the eigenvector matrices of the coupling Laplacians, which are guaranteed to change smoothly in time. In turn, this allows to extend the Master Stability Function formalism, which can be used to assess the stability of a synchronized state. This approach is independent from the particular topologies that the network visits, and is not restricted to commuting structures. Also, it does not depend on the time scale of the evolution, which can be faster than, comparable to, or even secular with respect to the the dynamics of the units.

  3. Synchronous temperature rate control for refrigeration with reduced energy consumption

    DOE Patents [OSTI]

    Gomes, Alberto Regio; Keres, Stephen L.; Kuehl, Steven J.; Litch, Andrew D.; Richmond, Peter J.; Wu, Guolian

    2015-09-22

    Methods of operation for refrigerator appliance configurations with a controller, a condenser, at least one evaporator, a compressor, and two refrigeration compartments. The configuration may be equipped with a variable-speed or variable-capacity compressor, variable speed evaporator or compartment fans, a damper, and/or a dual-temperature evaporator with a valve system to control flow of refrigerant through one or more pressure reduction devices. The methods may include synchronizing alternating cycles of cooling each compartment to a temperature approximately equal to the compartment set point temperature by operation of the compressor, fans, damper and/or valve system. The methods may also include controlling the cooling rate in one or both compartments. Refrigeration compartment cooling may begin at an interval before or after when the freezer compartment reaches its lower threshold temperature. Freezer compartment cooling may begin at an interval before or after when the freezer compartment reaches its upper threshold temperature.

  4. Advanced synchronous luminescence imaging for chemical and medical diagnostics

    DOE Patents [OSTI]

    Vo-Dinh, Tuan

    2006-09-05

    A diagnostic method and associated system includes the steps of exposing at least one sample location with excitation radiation through a single optical waveguide or a single optical waveguide bundle, wherein the sample emits emission radiation in response to the excitation radiation. The same single optical waveguide or the single optical waveguide bundle receives at least a portion of the emission radiation from the sample, thus providing co-registration of the excitation radiation and the emission radiation. The wavelength of the excitation radiation and emission radiation is synchronously scanned to produce a spectrum upon which an image can be formed. An increased emission signal is generated by the enhanced overlap of the excitation and emission focal volumes provided by co-registration of the excitation and emission signals thus increasing the sensitivity as well as decreasing the exposure time necessary to obtain an image.

  5. Synchronizing compute node time bases in a parallel computer

    DOE Patents [OSTI]

    Chen, Dong; Faraj, Daniel A; Gooding, Thomas M; Heidelberger, Philip

    2014-12-30

    Synchronizing time bases in a parallel computer that includes compute nodes organized for data communications in a tree network, where one compute node is designated as a root, and, for each compute node: calculating data transmission latency from the root to the compute node; configuring a thread as a pulse waiter; initializing a wakeup unit; and performing a local barrier operation; upon each node completing the local barrier operation, entering, by all compute nodes, a global barrier operation; upon all nodes entering the global barrier operation, sending, to all the compute nodes, a pulse signal; and for each compute node upon receiving the pulse signal: waking, by the wakeup unit, the pulse waiter; setting a time base for the compute node equal to the data transmission latency between the root node and the compute node; and exiting the global barrier operation.

  6. Non-synchronous control of self-oscillating resonant converters

    DOE Patents [OSTI]

    Glaser, John Stanley (Niskayuna, NY); Zane, Regan Andrew (Scotia, NY)

    2002-01-01

    A self-oscillating switching power converter has a controllable reactance including an active device connected to a reactive element, wherein the effective reactance of the reactance and the active device is controlled such that the control waveform for the active device is binary digital and is not synchronized with the switching converter output frequency. The active device is turned completely on and off at a frequency that is substantially greater than the maximum frequency imposed on the output terminals of the active device. The effect is to vary the average resistance across the active device output terminals, and thus the effective output reactance, thereby providing converter output control, while maintaining the response speed of the converter.

  7. Solar Electric Grid Integration - Advanced Concepts (SEGIS-AC...

    Broader source: Energy.gov (indexed) [DOE]

    Solar Electric Grid Integration - Advanced Concepts (SEGIS-AC) program, DOE is funding solar projects that are targeting ways to develop power electronics and build smarter, more...

  8. University Policy No.: AC1110 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1110 Classification: Academic and Students EDUCATIONAL SERVICE services and includes: · Development of educational materials in any form, including digital · Management

  9. University Policy No.: AC1145 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1145 Classification: Academic and Students Approving Authority, interdisciplinary programs, divisions, and the library) will undergo a review every five to seven years

  10. University Policy No.: AC1150 Classification: Academic and Students

    E-Print Network [OSTI]

    Victoria, University of

    University Policy No.: AC1150 Classification: Academic and Students TEACHING, portfolios, references, library resources, laboratories and equipment) related to the subject matter

  11. Non-vanishing ponderomotive AC electrophoretic effect for particle trapping

    SciTech Connect (OSTI)

    Guan, Weihau; Park, Jae Hyun nmn; Krstic, Predrag S; Reed, Mark A

    2011-01-01

    We present here a study on overlooked aspects of alternating current (AC) electrokinetics AC electrophoretic (ACEP) phenomena. The dynamics of a particle with both polarizability and net charges in a non-uniform AC electric trapping field is investigated. It is found that either electrophoretic (EP) or dielectrophoretic (DEP) effects can dominate the trapping dynamics, depending on experimental conditions. A dimensionless parameter gamma is developed to predict the relative strength of EP and DEP effects in a quadrupole AC field. An ACEP trap is feasible for charged particles in salt-free or low salt concentration solutions. In contrast to DEP traps, an ACEP trap favors the downscaling of the particle size.

  12. Theresa Windus elected ACS Physical Chemistry Division Councilor...

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

    Theresa Windus elected ACS Physical Chemistry Division Councilor Congratulations to Ames Laboratory faculty scientist Theresa Windus who has been elected Councilor to the Physical...

  13. Synchronization and time shifts of dynamical patterns for mutually delay-coupled fiber ring lasers

    E-Print Network [OSTI]

    L. B. Shaw; I. B. Schwartz; E. A. Rogers; R. Roy

    2006-03-27

    A pair of coupled erbium doped fiber ring lasers is used to explore the dynamics of coupled spatiotemporal systems. The lasers are mutually coupled with a coupling delay less than the cavity round-trip time. We study synchronization between the two lasers in the experiment and in a delay differential equation model of the system. Because the lasers are internally perturbed by spontaneous emission, we include a noise source in the model to obtain stochastic realizations of the deterministic equations. Both amplitude synchronization and phase synchronization are considered. We use the Hilbert transform to define the phase variable and compute phase synchronization. We find that synchronization increases with coupling strength in the experiment and the model. When the time series from two lasers are time-shifted in either direction by the delay time, approximately equal synchronization is frequently observed, so that a clear leader and follower cannot be identified. We define an algorithm to determine which laser leads the other when the synchronization is sufficiently different with one direction of time shift, and statistics of switches in leader and follower are studied. The frequency of switching between leader and follower increases with coupling strength, as might be expected since the lasers mutually influence each other more effectively with stronger coupling.

  14. Abnormal Synchronizing Path of Delay-coupled Chaotic Oscillators on the Edge of Stability

    E-Print Network [OSTI]

    Zhuo, Zhao; Fu, Zhong-Qian

    2015-01-01

    In this paper, the transition of synchronizing path of delay-coupled chaotic oscillators in a scale-free network is highlighted. Mainly, through the critical transmission delay makes chaotic oscillators be coupled on the edge of stability, we find that the transition of synchronizing path is \\emph{abnormal}, which is characterized by the following evidences: (a) synchronization process starts with low-degree rather than high-degree ones; (b) the high-degree nodes don't undertake the role of hub; (c) the synchronized subnetworks show a poor small-world property as a result of hubs absence; (d) the clustering synchronization behavior emerges even community structure is absent in the scale-free network. This abnormal synchronizing path suggests that the diverse synchronization behaviors occur in the same topology, which implies that the relationship between dynamics and structure of network is much more complicated than the common sense that the structure is the foundation of dynamics. Moreover, it also reveals ...

  15. Magnet Cable Manufacturing

    E-Print Network [OSTI]

    Royet, J.M.

    2011-01-01

    J. Royet, "Magnet Cable Manufacturing", oral presentation atDivision Magnet Cable Manufacturing J. Royet October 1990J I Magnet Cable Manufacturing* John Royet Accelerator &

  16. Synchronization and an application of a novel fractional order King Cobra chaotic system

    SciTech Connect (OSTI)

    Muthukumar, P., E-mail: muthukumardgl@gmail.com; Balasubramaniam, P., E-mail: balugru@gmail.com [Department of Mathematics, Gandhigram Rural Institute?Deemed University, Gandhigram 624 302, Tamilnadu (India); Ratnavelu, K., E-mail: kuru052001@gmail.com [Faculty of Science, Institute of Mathematical Sciences, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2014-09-01

    In this paper, we design a new three dimensional King Cobra face shaped fractional order chaotic system. The multi-scale synchronization scheme of two fractional order chaotic systems is described. The necessary conditions for the multi-scale synchronization of two identical fractional order King Cobra chaotic systems are derived through feedback control. A new cryptosystem is proposed for an image encryption and decryption by using synchronized fractional order King Cobra chaotic systems with the supports of multiple cryptographic assumptions. The security of the proposed cryptosystem is analyzed by the well known algebraic attacks. Numerical simulations are given to show the effectiveness of the proposed theoretical results.

  17. Generation-based memory synchronization in a multiprocessor system with weakly consistent memory accesses

    DOE Patents [OSTI]

    Ohmacht, Martin

    2014-09-09

    In a multiprocessor system, a central memory synchronization module coordinates memory synchronization requests responsive to memory access requests in flight, a generation counter, and a reclaim pointer. The central module communicates via point-to-point communication. The module includes a global OR reduce tree for each memory access requesting device, for detecting memory access requests in flight. An interface unit is implemented associated with each processor requesting synchronization. The interface unit includes multiple generation completion detectors. The generation count and reclaim pointer do not pass one another.

  18. Magnetic Stereoscopy

    E-Print Network [OSTI]

    Thomas Wiegelmann; Bernd Inhester

    2006-12-21

    The space mission STEREO will provide images from two viewpoints. An important aim of the STEREO mission is to get a 3D view of the solar corona. We develop a program for the stereoscopic reconstruction of 3D coronal loops from images taken with the two STEREO spacecraft. A pure geometric triangulation of coronal features leads to ambiguities because the dilute plasma emissions complicates the association of features in image 1 with features in image 2. As a consequence of these problems the stereoscopic reconstruction is not unique and multiple solutions occur. We demonstrate how these ambiguities can be resolved with the help of different coronal magnetic field models (potential, linear and non-linear force-free fields). The idea is that, due to the high conductivity in the coronal plasma, the emitting plasma outlines the magnetic field lines. Consequently the 3D coronal magnetic field provides a proxy for the stereoscopy which allows to eliminate inconsistent configurations. The combination of stereoscopy and magnetic modelling is more powerful than one of these tools alone. We test our method with the help of a model active region and plan to apply it to the solar case as soon as STEREO data become available.

  19. Low temperature magnetic properties of magnesium substituted YbMnO{sub 3}

    SciTech Connect (OSTI)

    Sattibabu, Bhumireddi Bhatnagar, Anil K. Mohan, Dasari Das, Dibakar Sundararaman, Mahadevan; Siruguri, Vasudeva; Rayaprol, Sudhindra

    2014-04-24

    Structural and magnetic properties of polycrystalline Yb{sub 1?x}Mg{sub x}MnO{sub 3} (x = 0, 0.05 and 0.10) hexagonal compounds prepared by solid state method, have been studied. The structural analyses of the samples were carried out by Rietveld analysis of neutron diffraction data. With increasing Mg content, we find that the lattice parameter a decreases and c increases whereas the overall Mn-O bond length decreases. Magnetization measured as a function of magnetic field at 2.5 K exhibits hysteresis, which is attributed to ferromagnetic like ordering of Yb{sup 3+} sublattice. Temperature dependence of ac magnetic susceptibility, ?{sub ac}(T), shows no signature of spin-glass behavior. ?”(T) exhibits a sudden increase at low temperatures which is due to ordering of Yb{sup 3+} sublattice.

  20. Journal of the Korean Physical Society, Vol. 40, No. 1, January 2002, pp. 8789 Synchronous Mirror Delay for Zero-and Multi-Phase Locking

    E-Print Network [OSTI]

    Lee, Jong Duk

    ) A clock generation circuit used in synchronous SRAM (static random access memory) was de- signedJournal of the Korean Physical Society, Vol. 40, No. 1, January 2002, pp. 8789 Synchronous Mirror by adapting SMD (synchronous mirror delay) scheme. A multi-phase synchronous circuit suited for the double

  1. 866 IEEE TRANSACTIONS ON MAGNETICS, VOL. 44, NO. 6, JUNE 2008 Dynamical Models for Eddy Current in Ferromagnetic Cores Introduced in

    E-Print Network [OSTI]

    Boyer, Edmond

    866 IEEE TRANSACTIONS ON MAGNETICS, VOL. 44, NO. 6, JUNE 2008 Dynamical Models for Eddy Current accurate dynamical models for representing eddy currents are studied. The simulation of the relay is provided. Index Terms--AC circuit breakers (CBs), eddy currents, magnetic hysteresis, optimization methods

  2. AVTA: ChargePoint AC Level 2 Charging System Testing Results...

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

    ChargePoint AC Level 2 Charging System Testing Results AVTA: ChargePoint AC Level 2 Charging System Testing Results The Vehicle Technologies Office's Advanced Vehicle Testing...

  3. , : roym@ee.technion.ac.il -OpenStack

    E-Print Network [OSTI]

    Cidon, Israel

    (OVS) . , , . OpenFlow. #12; OpenFlow and SDN Emulating Data-Centers by MiniNet : yanivbi@tx.technion.ac.il ( Data , . Topology Verification in OpenFlow datacenter networks : yanivbi@tx.technion.ac.il Datacenter. , mininet datacenter , " . -datacenter , Openflow. 2

  4. www.swansea.ac.uk/artsandhumanities Arts and Humanities

    E-Print Network [OSTI]

    Martin, Ralph R.

    dissertation or design a research project of their own (with 10,000 word report) which draws on issues Email: rhys.jones@swansea.ac.uk www.swansea.ac.uk/mediastudies/admissions - The Potter Guide to Higher relations, humanities, social science, computer science or related background. Professionals interested

  5. Aalborg Universitet Cooperative Frequency Control for Autonomous AC Microgrids

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Cooperative Frequency Control for Autonomous AC Microgrids Shafiee, Qobad, J. C. V., & Guerrero, J. M. (2015). Cooperative Frequency Control for Autonomous AC Microgrids.aau.dk on: november 29, 2015 #12;This document downloaded from www.microgrids.et.aau.dk is the preprint

  6. ACADEMIC PLAN ENGAE-AC OLD CURRICULUM CODE_388_

    E-Print Network [OSTI]

    Qiu, Weigang

    ACADEMIC PLAN ENGAE-AC OLD CURRICULUM CODE_388_ DEGREE CODE _40 Hunter College of the City. Student's Signature Date ____________________ #12;ACADEMIC PLAN ENGAE-AC OLD CURRICULUM CODE_388_ DEGREE Study of Young Adult Literature in Our Diverse Society 3 Fall Spring Summer SEDC 720 Adolescent- Health

  7. Undergraduate study 2016 www.nottingham.ac.uk/psychology

    E-Print Network [OSTI]

    Qu, Rong

    Psychology Undergraduate study 2016 www.nottingham.ac.uk/psychology For general undergraduate: www.nottingham.ac.uk/faqs #12;Contents Welcome to the School of Psychology Psychology of conflicts, accidents and mental disorders. The University of Nottingham's School of Psychology is one

  8. www.mmu.ac.uk/careers Careers & Employability Service

    E-Print Network [OSTI]

    ;www.mmu.ac.uk/careers Identifying courses · www.prospects.ac.uk/search_courses.htm · www: Courses to allow you to enter certain professions Courses that build your skills in a new area Examples · MRes (taught prep for further research) These usually involve lectures for the first two terms

  9. www.le.ac.uk/physics UNDERGRADUATE COURSES IN

    E-Print Network [OSTI]

    Banaji,. Murad

    www.le.ac.uk/physics UNDERGRADUATE COURSES IN Physics and Astronomy Department of Physics and Astronomy #12;www.le.ac.uk/physics-ug "The Leicester Department of Physics and Astronomy offers superb courses. Students get a broader exposure to different areas of physics and astronomy than is possible

  10. Modeling, analysis and simulation of "AC inductor" based converters

    E-Print Network [OSTI]

    for current sourcing applications, such as battery chargers, where differences between the average input.g. 2-8]. II. LARGE SIGNAL ANALYSIS OF THE "AC INDUCTOR" BASED CHARGERS To describe the behavior of AC inductor topologies, we first consider the non-isolated charger shown in Fig. 1. Isolation can be obtained

  11. International Student Guide www.swansea.ac.uk/geography

    E-Print Network [OSTI]

    Harman, Neal.A.

    International Student Guide Geography www.swansea.ac.uk/geography www.swansea.ac.uk/science/international #12;Reasons to study at Swansea University Geography at Swansea University Established in 1920, 36th and more Over 15,000 students / Over 2,000 International students Rated as one of the top 20 Geography

  12. European Student Guide www.swansea.ac.uk/geography

    E-Print Network [OSTI]

    Harman, Neal.A.

    European Student Guide Geography www.swansea.ac.uk/geography www.swansea.ac.uk/science/international #12;Reasons to study at Swansea University Geography at Swansea University Established in 1920, 36th and more Over 15,000 students / Over 2,000 International students Rated as one of the top 20 Geography

  13. Hydrodynamic Synchronization and Metachronal Waves on the Surface of the Colonial Alga Volvox carteri

    E-Print Network [OSTI]

    Goldstein, Raymond E.

    Hydrodynamic Synchronization and Metachronal Waves on the Surface of the Colonial Alga Volvox of metachronal waves on the surface of the colonial alga Volvox carteri, whose large size and ease

  14. Channel Modeling and Time Delay Estimation for Clock Synchronization Among Seaweb Nodes

    SciTech Connect (OSTI)

    Gagnon, P; Rice, J; Clark, G A

    2012-07-08

    From simulations, tracking of the impulse response is feasible. Potential to benefit other functions such as ranging between two nodes. Potential to combine the features of different protocols to create a new and more realistic clock-synchronization protocol.

  15. Joint sequence estimation and synchronization using wavelet pulses in a communication system 

    E-Print Network [OSTI]

    Wannasakwong, Marisa

    1994-01-01

    A new kind of baseband pulse is introduced in a receiver using nonsynchronized uniform samples. The pulse is an orthonormal wavelet generated by a discrete filter. Its performance is examined by applying a sequence estimation and synchronization...

  16. Automated Design Optimization of Synchronous Machines: Development and Application of a Generic Fitness Evaluation Framework 

    E-Print Network [OSTI]

    Deshpande, Yateendra Balkrishna

    2014-12-15

    A rotating synchronous electric machine design can be described to its entirety by a combination of 17 to 24 discrete and continuous parameters pertaining the geometry, material selection, and electrical loading. Determining ...

  17. A real-time DSP GMSK modem with all-digital symbol synchronization 

    E-Print Network [OSTI]

    Lambert, Richard Paul

    1998-01-01

    In communication systems, a requirement of the receiver is to estimate symbol timing so that symbol decisions may be made at the instant of smallest intersymbol interference. Though there exist various analog techniques for synchronization...

  18. A New, Iterative, Synchronous-Response Algorithm for Analyzing the Morton Effect 

    E-Print Network [OSTI]

    Saha, Rohit

    2012-02-14

    viscosity of the lubricant, (3) bearing radial clearance to radius ratio and (4) overhung mass magnitude is performed to consider their respective impacts on synchronous response. Based on the available input data and the cases considered, reducing viscosity...

  19. Cluster synchronization induced by one-node clusters in networks with asymmetric negative couplings

    SciTech Connect (OSTI)

    Zhang, Jianbao [School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China)] [School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China); Ma, Zhongjun, E-mail: mzj1234402@163.com [School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004 (China)] [School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004 (China); Zhang, Gang [College of Mathematics and Information Science, Hebei Normal University, Shijiazhuang 050024 (China)] [College of Mathematics and Information Science, Hebei Normal University, Shijiazhuang 050024 (China)

    2013-12-15

    This paper deals with the problem of cluster synchronization in networks with asymmetric negative couplings. By decomposing the coupling matrix into three matrices, and employing Lyapunov function method, sufficient conditions are derived for cluster synchronization. The conditions show that the couplings of multi-node clusters from one-node clusters have beneficial effects on cluster synchronization. Based on the effects of the one-node clusters, an effective and universal control scheme is put forward for the first time. The obtained results may help us better understand the relation between cluster synchronization and cluster structures of the networks. The validity of the control scheme is confirmed through two numerical simulations, in a network with no cluster structure and in a scale-free network.

  20. A Comparison of Software and Hardware Synchronization Mechanisms for Distributed Shared Memory Multiprocessors

    E-Print Network [OSTI]

    A Comparison of Software and Hardware Synchronization Mechanisms for Distributed Shared Memory of traditional multiprocessors have included hardware support only for simple operations such as compare primitives in hardware. In particular, as part of maintaining data consistency, these architectures maintain

  1. Optical phase dynamics in mutually coupled diode laser systems exhibiting power synchronization

    E-Print Network [OSTI]

    Vishwa Pal; Awadhesh Prasad; R Ghosh

    2011-11-10

    We probe the physical mechanism behind the known phenomenon of power synchronization of two diode lasers that are mutually coupled via their delayed optical fields. In a diode laser, the amplitude and the phase of the optical field are coupled by the so-called linewidth enhancement factor, $\\alpha$. In this work, we explore the role of optical phases of the electric fields in amplitude (and hence power) synchronization through $\\alpha$ in such mutually delay-coupled diode laser systems. Our numerical results show that the synchronization of optical phases drives the powers of lasers to synchronized death regimes. We also find that as $\\alpha$ varies for different diode lasers, the system goes through a sequence of in-phase amplitude-death states. Within the windows between successive amplitude-death regions, the cross-correlation between the field amplitudes exhibits a universal power-law behaviour with respect to $\\alpha$.

  2. ac response of thin superconductors in the flux-creep regime

    SciTech Connect (OSTI)

    Gurevich, A. [Applied Superconductivity Center, University of Wisconsin, Madison, Wisconsin 53706 (United States)] [Applied Superconductivity Center, University of Wisconsin, Madison, Wisconsin 53706 (United States); Brandt, E.H. [Max Planck Institute fuer Metallforschung, D-70506 Stuttgart (Germany)] [Max Planck Institute fuer Metallforschung, D-70506 Stuttgart (Germany)

    1997-05-01

    We calculate both analytically and numerically the ac susceptibility {chi}({omega}) and the nonlinear electromagnetic response of thin superconductor strips and disks of constant thickness in a perpendicular time-dependent magnetic field B{sub a}(t)=B{sub 0}cos{omega}t, taking account of the strong nonlinearity of the voltage-current characteristics below the irreversibility line. We consider integral equations of nonlinear nonlocal flux diffusion for a wide class of thermally activated creep models. It is shown that thin superconductors, despite being fully in the critical state, exhibit a universal Meissner-like electromagnetic response in the dissipative flux-creep regime. The expression for the linear ac susceptibility during flux creep appears to be similar to the susceptibility of Ohmic conductors, but with the relaxation time constant replaced by the time t elapsed after flux creep has started. This result is independent of any material parameter or temperature or dc field. For {omega}t{gt}1, we obtain {chi}({omega}){approx}{minus}1+pln(qi{omega}t)/(i{omega}t), where p and q are constants. Above a critical ac amplitude B{sub 0}=B{sub l}, the local response of the electric field becomes nonlinear, and there are two distinctive nonlinear regimes at B{sub 0}{gt}B{sub l}, where B{sub l}{approximately}s(d/a){sup 1/2}B{sub p}, B{sub p} is a characteristic field of full flux penetration, s(T,B)={vert_bar}dlnj/dlnt{vert_bar} is the dimensionless flux-creep rate and d and a are the sample thickness and width, respectively. For B{sub l}{lt}B{sub 0}{lt}B{sub h}({omega}) the response of the electric field is strongly nonlinear but nonhysteretic, since the ac field B{sub a}(t) does not cause a periodic inversion of the critical state. As a result, the magnetic moment exhibits a Meissner-like {ital nondissipative} response, in stark contrast to the Bean model. (Abstract Truncated)

  3. Brushless machine having ferromagnetic side plates and side magnets

    DOE Patents [OSTI]

    Hsu, John S

    2012-10-23

    An apparatus is provided having a cylindrical stator and a rotor that is spaced from a stator to define an annular primary air gap that receives AC flux from the stator. The rotor has a plurality of longitudinal pole portions disposed parallel to the axis of rotation and alternating in polarity around a circumference of the rotor. Each longitudinal pole portion includes portions of permanent magnet (PM) material and at least one of the longitudinal pole portions has a first end and an opposing second end and a side magnet is disposed adjacent the first end and a side pole is disposed adjacent the second end.

  4. Security analysis of communication system based on the synchronization of different order chaotic systems

    E-Print Network [OSTI]

    G. Alvarez; L. Hernandez; J. Munoz; F. Montoya; Shujun Li

    2005-06-27

    This work analyzes the security weakness of a recently proposed communication method based on chaotic modulation and masking using synchronization of two chaotic systems with different orders. It is shown that its application to secure communication is unsafe, because it can be broken in two different ways, by high-pass filtering and by reduced order system synchronization, without knowing neither the system parameter values nor the system key.

  5. Synchronizing carrier frequencies of co-channel amplitude-modulated broadcast

    DOE Patents [OSTI]

    Smith, Stephen F. (London, TN); Moore, James A. (Powell, TN)

    2007-05-15

    Systems and methods are described for carrier-frequency synchronization for improved AM and TV broadcast reception. A method includes synchronizing a carrier frequency of a broadcast signal with a remote reference frequency. An apparatus includes a reference signal receiver; a phase comparator coupled to the reference signal receiver; a voltage controlled oscillator coupled to the phase comparator; and a radio frequency output coupled to the voltage controlled oscillator.

  6. Carrier-frequency synchronization system for improved amplitude modulation and television broadcast reception

    DOE Patents [OSTI]

    Smith, Stephen F.; Moore, James A.

    2003-05-13

    Systems and methods are described for carrier-frequency synchronization for improved AM and TV broadcast reception. A method includes synchronizing a carrier frequency of a broadcast signal with a remote reference frequency. An apparatus includes a reference signal receiver; a phase comparator coupled to the reference signal receiver; a voltage controlled oscillator coupled to the phase comparator; and a radio frequency output coupled to the voltage controlled oscillator.

  7. Impact of the Geo-synchronous Orbit Radiation Environment on the Design of Astronomical Observatories

    E-Print Network [OSTI]

    Kruk, Jeffrey W; Armani, Nerses; Stauffer, Craig; Hirata, Christopher M

    2015-01-01

    Geo-Synchronous orbits are appealing for Solar or astrophysical observatories because they permit continuous data downlink at high rates. The radiation environment in these orbits presents unique challenges, however. This paper describes the characteristics of the radiation environment in Geo-Synchronous orbit and the implications for instrument design. Radiation-induced background event rates are given for some simplified shielding models, and for a detailed model of the proposed Wide-Field InfraRed Survey Telescope observatory.

  8. Control and Synchronization of Chaotic Fractional-Order Coullet System via Active Controller

    E-Print Network [OSTI]

    M. Shahiri T.; A. Ranjbar N.; R. Ghaderi; S. H. Hosseinnia; S. Momani

    2012-06-12

    In this paper, fractional order Coullet system is studied. An active control technique is applied to control this chaotic system. This type of controller is also applied to synchronize chaotic fractional-order systems in master-slave structure. The synchronization procedure is shown via simulation. The boundary of stability is obtained by both of theoretical analysis and simulation result. The numerical simulations show the effectiveness of the proposed controller.

  9. SORB-AC Cartridge Pumps MK5 Series w e s u p p o r t y o u r i n n o v a t i o n

    E-Print Network [OSTI]

    Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

    in HV and UHV pressure region No low pressure limitation (down to 10-12 Torr region) Reversible pumping Operation in the presence of high magnetic fields Oil free and vibration free ultra high vacuum Low weight as low as 350 °C if maintained for a suitably long time. SORB AC Cartridge pumps find wide use

  10. Probing Water Phases in Cement Blends using 1 Magnetic Resonance Relaxometry

    E-Print Network [OSTI]

    Sheffield, University of

    Probing Water Phases in Cement Blends using 1 H Nuclear Magnetic Resonance Relaxometry Jean)114 222 5973 Fax: +44 (0)114 222 5943 E-Mail: j.gorce@sheffield.ac.uk Extended Abstract: Cement and Concrete Science, Warwick, 16th + 17th September 2004 Introduction The nuclear industry uses blended cement

  11. Donna Rose Addis, TWRI, May 2004 1 ANALYSIS OF FUNCTIONAL MAGNETIC RESONANCE

    E-Print Network [OSTI]

    Addis, Donna Rose

    Donna Rose Addis, TWRI, May 2004 1 ANALYSIS OF FUNCTIONAL MAGNETIC RESONANCE IMAGING DATA USING SPM-ordinates (with signs reversed) into table as translations right, fwd and up · Check origin is at the AC · Select images (a_seg1.img, a_seg2 and brain_a.img) · Name output file (grey_clean) · Enter formula

  12. Soft Magnetic Materials in High-Frequency, High-Power Conversion Applications

    E-Print Network [OSTI]

    McHenry, Michael E.

    and facilitate two-way power conversion.7 Flexible alternating current (AC) Transmission Systems (FACTS) and High Voltage DC (HVDC) technologies aim to improve the effi- ciency of power networks and benefit from highSoft Magnetic Materials in High-Frequency, High-Power Conversion Applications ALEX M. LEARY,1

  13. Cell body rocking is a dominant mechanism for flagellar synchronization in a swimming alga

    E-Print Network [OSTI]

    Veikko Geyer; Frank Jülicher; Jonathon Howard; Benjamin M Friedrich

    2013-11-23

    The unicellular green algae Chlamydomonas swims with two flagella, which can synchronize their beat. Synchronized beating is required to swim both fast and straight. A long-standing hypothesis proposes that synchronization of flagella results from hydrodynamic coupling, but the details are not understood. Here, we present realistic hydrodynamic computations and high-speed tracking experiments of swimming cells that show how a perturbation from the synchronized state causes rotational motion of the cell body. This rotation feeds back on the flagellar dynamics via hydrodynamic friction forces and rapidly restores the synchronized state in our theory. We calculate that this `cell body rocking' provides the dominant contribution to synchronization in swimming cells, whereas direct hydrodynamic interactions between the flagella contribute negligibly. We experimentally confirmed the coupling between flagellar beating and cell body rocking predicted by our theory. This work appeared also in the Proceedings of the National Academy of Science of the U.S.A as: Geyer et al., PNAS 110(45), p. 18058(6), 2013.

  14. Fast Sparsely Synchronized Brain Rhythms in A Scale-Free Neural Network

    E-Print Network [OSTI]

    Kim, Sang-Yoon

    2015-01-01

    We consider a directed Barab\\'{a}si-Albert scale-free network model with symmetric preferential attachment with the same in- and out-degrees, and study emergence of sparsely synchronized rhythms for a fixed attachment degree in an inhibitory population of fast spiking Izhikevich interneurons. For a study on the fast sparsely synchronized rhythms, we fix $J$ (synaptic inhibition strength) at a sufficiently large value, and investigate the population states by increasing $D$ (noise intensity). For small $D$, full synchronization with the same population-rhythm frequency $f_p$ and mean firing rate (MFR) $f_i$ of individual neurons occurs, while for sufficiently large $D$ partial synchronization with $f_p > {\\langle f_i \\rangle}$ ($\\langle f_i \\rangle$: ensemble-averaged MFR) appears due to intermittent discharge of individual neurons; particularly, the case of $f_p > 4 {\\langle f_i \\rangle}$ is referred to as sparse synchronization. Only for the partial and sparse synchronization, MFRs and contributions of indiv...

  15. Personal Web Archive: E-mail: waka@iplab.cs.tsukuba.ac.jp, {shizuki,jiro}@cs.tsukuba.ac.jp

    E-Print Network [OSTI]

    Tanaka, Jiro

    Personal Web Archive: Web E-mail: waka@iplab.cs.tsukuba.ac.jp, {shizuki,jiro}@cs.tsukuba.ac.jp Web Web Web Web Web Web Personal Web Archive Personal Web Archive: Support System for Browsing the Versions of Web Page Ryota WAKAMATSU Buntarou SHIZUKI Jiro TANAKA Graduate School of Systems

  16. Motor technology for mining applications advances

    SciTech Connect (OSTI)

    Fiscor, S.

    2009-08-15

    AC motors are steadily replacing DC motors in mining and mineral processing equipment, requiring less maintenance. The permanent magnet rotor, or the synchronous motor, has enabled Blador to introduce a line of cooling tower motors. Synchronous motors are soon likely to take over from the induction motor. 1 photo.

  17. Magnetic Reconnection

    SciTech Connect (OSTI)

    Masaaki Yamada, Russell Kulsrud and Hantao Ji

    2009-09-17

    We review the fundamental physics of magnetic reconnection in laboratory and space plasmas, by discussing results from theory, numerical simulations, observations from space satellites, and the recent results from laboratory plasma experiments. After a brief review of the well-known early work, we discuss representative recent experimental and theoretical work and attempt to interpret the essence of significant modern findings. In the area of local reconnection physics, many significant findings have been made with regard to two- uid physics and are related to the cause of fast reconnection. Profiles of the neutral sheet, Hall currents, and the effects of guide field, collisions, and micro-turbulence are discussed to understand the fundamental processes in a local reconnection layer both in space and laboratory plasmas. While the understanding of the global reconnection dynamics is less developed, notable findings have been made on this issue through detailed documentation of magnetic self-organization phenomena in fusion plasmas. Application of magnetic reconnection physics to astrophysical plasmas is also brie y discussed.

  18. Non-linear power spectra in the synchronous gauge

    E-Print Network [OSTI]

    Jai-chan Hwang; Hyerim Noh; Donghui Jeong; Jinn-Ouk Gong; Sang Gyu Biern

    2014-08-20

    We study the non-linear corrections to the matter and velocity power spectra in the synchronous gauge (SG). We consider the perturbations up to third order in a zero-pressure fluid in flat cosmological background, which is relevant for the non-linear growth of cosmic structure. As a result, we point out that the SG is an inappropriate coordinate choice when handling the non-linear growth of the large-scale structure. Although the equations in the SG happen to coincide with those in the comoving gauge (CG) to linear order, they differ from second order. In particular, the second order hydrodynamic equations in the the SG are apparently in the Lagrangian form, whereas those in the CG are in the Eulerian form. Thus, the non-linear power spectra naively presented in the original SG show strange behavior quite different from the result of the Newtonian theory even on sub-horizon scales. The power spectra in the SG show regularized behaviors only after we introduce convective terms in the second order so that the equations in two gauges coincide to the second order.

  19. Magnetic field gradients in solar wind plasma and geophysics periods

    E-Print Network [OSTI]

    A. Bershadskii

    2006-11-16

    Using recent data obtained by Advanced Composition Explorer (ACE) the pumping scale of the magnetic field gradients of the solar wind plasma has been calculated. This pumping scale is found to be equal to 24h $\\pm$ 2h. The ACE spacecraft orbits at the L1 libration point which is a point of Earth-Sun gravitational equilibrium about 1.5 million km from Earth. Since the Earth's magnetosphere extends into the vacuum of space from approximately 80 to 60,000 kilometers on the side toward the Sun the pumping scale cannot be a consequence of the 24h-period of the Earth's rotation. Vise versa, a speculation is suggested that for the very long time of the coexistence of Earth and of the solar wind the weak interaction between the solar wind and Earth could lead to stochastic synchronization between the Earth's rotation and the pumping scale of the solar wind magnetic field gradients. This synchronization could transform an original period of the Earth's rotation to the period close to the pumping scale of the solar wind magnetic field gradients.

  20. Patterned Magnetic Nanostructures and Quantized Magnetic Disks

    E-Print Network [OSTI]

    -increasing demands in data storage and to new applications of magnetic devices in the field of sensors. NewPatterned Magnetic Nanostructures and Quantized Magnetic Disks STEPHEN Y. CHOU Invited Paper, opens up new opportunities for engineering innovative magnetic materials and devices, developing ultra

  1. IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 17, NO. 2, FEBRUARY 2005 483 Synchronously Pumped Optical Parametric Oscillator

    E-Print Network [OSTI]

    Keller, Ursula

    , and D. J. Richardson are with the Optoelec- tronics Research Center (ORC), University of Southampton, Southampton SO17 1BJ, U.K. (e-mail: anm@orc.soton.ac.uk; djr@orc.soton.ac.uk). Digital Object Identifier 10

  2. HVDC-AC system interaction from AC harmonics. Volume 1. Harmonic impedance calculations. Final report

    SciTech Connect (OSTI)

    Breuer, G D; Chow, J H; Lindh, C B; Miller, N W; Numrich, F H; Price, W W; Turner, A E; Whitney, R R

    1982-09-01

    Improved methods are needed to characterize ac system harmonic behavior for ac filter design for HVDC systems. The purpose of this General Electric Company RP1138 research is to evaluate the present filter design practice and to investigate methods for calculating system harmonic impedances. An overview of ac filter design for HVDC systems and a survey of literature related to filter design have been performed. Two methods for calculating system harmonic impedances have been investigated. In the measurement method, an instrumentation system for measuring system voltage and current has been assembled. Different schemes of using the measurements to calculate system harmonic impedances have been studied. In the analytical method, a procedure to include various operating conditions has been proposed. Computer programs for both methods have been prepared, and the results of the measurement and analytical methods analyzed. A conclusion of the project is that the measurement and analytical methods both provided reasonable results. There are correlations between the measured and analytical results for most harmonics, although there are discrepancies between the assumptions used in the two methods. A sensitivity approach has been proposed to further correlate the results. From the results of the analysis, it is recommended that both methods should be tested further. For the measurement method, more testing should be done to cover different system operating conditions. In the analytical method, more detailed models for representing system components should be studied. In addition, alternative statistical and sensitivity approaches should be attempted.

  3. Aalborg Universitet Power flow analysis for droop controlled LV hybrid AC-DC microgrids with virtual

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Power flow analysis for droop controlled LV hybrid AC-DC microgrids controlled LV hybrid AC-DC microgrids with virtual impedance. In Proceedings of the IEEE Power & Energy Interlinking converter PV WT IBS DC microgrid DC microgrid AC microgrid AC Load Figure 1. Structure

  4. The vibration research of the AC dipole-girder system for CSNS/RCS

    E-Print Network [OSTI]

    Liu Renhong; Zhang Junsong; Qu Huamin; Kang Ling; Wang Motuo; Wang Guangyuan; Wang Haijing

    2013-07-15

    China spallation neutron source(CSNS) is a high intensity proton accelerator based facility, and its accelerator complex includes two main parts: an H- linac and a rapid cycling synchrotron(RCS). The rcs accumulates the 80MeV proton beam, and accelerates it to 1.6GeV, with a repetition rate of 25 Hz. The AC dipole of the RCS is operated at a 25Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. The dipole magnet of RCS is active vibration equipment which is different with ground vibration accelerator. It is very important to design and research the dynamic characteristic of the dipole-girder system. This paper takes the dipole and girder as a specific model system, a method for researching the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. The ansys simulation method plays a very important role in the girder structure design stage. With the method the mechanical resonance phenomenon was avoided in the girder design time. At the same time the dipole vibratory force will influence the other equipment through the girder. It is necessary to isolate and decrease the dipole vibration. So a new isolator was designed to isolate the vibratory force and decrease the vibration amplitude of the magnet.

  5. Superconducting Magnet Division

    E-Print Network [OSTI]

    Gupta, Ramesh

    Superconducting Magnet Division Permanent Magnet Designs with Large Variations in Field Strength the residual field of the magnetized bricks by concentrating flux lines at the iron pole. Low Field Design Medium Field Design Superconducting Magnet Division Dipole and Quadrupole Magnets for RHIC e

  6. Superconducting magnet

    DOE Patents [OSTI]

    Satti, John A. (Naperville, IL)

    1980-01-01

    A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.

  7. Study and Development of Anti-Islanding Control for Synchronous Machine-Based Distributed Generators: November 2001--March 2004

    SciTech Connect (OSTI)

    Ye, Z.

    2006-03-01

    This report summarizes the study and development of new active anti-islanding control schemes for synchronous machine-based distributed generators, including engine generators and gas turbines.

  8. Complete chaotic synchronization and exclusion of mutual Pyragas control in two delay-coupled Rössler-type oscillators

    E-Print Network [OSTI]

    Thomas Jüngling; Hartmut Benner; Hiroyuki Shirahama; Kazuhiro Fukushima

    2011-06-22

    Two identical chaotic oscillators that are mutually coupled via time delayed signals show very complex patterns of completely synchronized dynamics including stationary states and periodic as well as chaotic oscillations. We have experimentally observed these synchronized states in delay-coupled electronic circuits and have analyzed their stability by numerical simulations and analytical calculations. We found that the conditions for longitudinal and transversal stability largely exclude each other and prevent e.g. the synchronization of Pyragas-controlled orbits. Most striking is the observation of complete chaotic synchronization for large delay times, which should not be allowed in the given coupling scheme on the background of the actual paradigm.

  9. Magnetic interactions in ?-Fe{sub 2}O{sub 3}@SiO{sub 2} nanocomposites

    SciTech Connect (OSTI)

    El Mendili, Y.; Bardeau, J.-F.; Greneche, J.-M.; Randrianantoandro, N.; Grasset, F.; Cador, O.; Guizouarn, T.

    2014-08-07

    Structural and magnetic properties of ?-Fe{sub 2}O{sub 3} nanoparticles of 4?nm diameter, dispersed into silica SiO{sub 2} matrix with a wide range value of volume fraction (0.05 to 1), were investigated. Produced ?-Fe{sub 2}O{sub 3}@SiO{sub 2} nanocomposites consist of an assembly of very small single domain magnetic object (<10?nm) with a random distribution of both inter-particle distance and direction of particle magnetic moment. We focused on the determination of a magnetic percolation threshold, defined as the magnetic particles concentration value above which the magnetic properties of isolated particles vanished in favor of a magnetic collective behavior induced by magnetic interactions. A percolation threshold value of 0.63 was obtained by a local probe technique such as {sup 57}Fe Mössbauer spectrometry and confirmed by global magnetic measurements through zero-field cooled, field-cooled, and ac susceptibility data. Below this threshold, dynamic ac magnetization measurements show a thermally activated Arrhenius dependence of the blocking temperature of superparamagnetic nanoparticles and above this critical value, one observes a slowing down of their dynamic properties, which lead toward the establishment of a spin-glass like state.

  10. Comparative Study of Magnetic Properties of Nanoparticles by High-Frequency Heat Dissipation and Conventional Magnetometry

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

    Malik, V.; Goodwill, J.; Mallapragada, S.; Prozorov, T.; Prozorov, R.

    2014-11-13

    The rate of heating of a water-based colloid of uniformly sized 15 nm magnetic nanoparticles by high-amplitude and high-frequency ac magnetic field induced by the resonating LC circuit (nanoTherics Magnetherm) was measured. The results are analyzed in terms of specific energy absorption rate (SAR). Fitting field amplitude and frequency dependences of SAR to the linear response theory, magnetic moment per particles was extracted. The value of magnetic moment was independently evaluated from dc magnetization measurements (Quantum Design MPMS) of a frozen colloid by fitting field-dependent magnetization to Langevin function. The two methods produced similar results, which are compared to themore »theoretical expectation for this particle size. Additionally, analysis of SAR curves yielded effective relaxation time.« less

  11. Comparative Study of Magnetic Properties of Nanoparticles by High-Frequency Heat Dissipation and Conventional Magnetometry

    SciTech Connect (OSTI)

    Malik, V.; Goodwill, J.; Mallapragada, S.; Prozorov, T.; Prozorov, R.

    2014-11-13

    The rate of heating of a water-based colloid of uniformly sized 15 nm magnetic nanoparticles by high-amplitude and high-frequency ac magnetic field induced by the resonating LC circuit (nanoTherics Magnetherm) was measured. The results are analyzed in terms of specific energy absorption rate (SAR). Fitting field amplitude and frequency dependences of SAR to the linear response theory, magnetic moment per particles was extracted. The value of magnetic moment was independently evaluated from dc magnetization measurements (Quantum Design MPMS) of a frozen colloid by fitting field-dependent magnetization to Langevin function. The two methods produced similar results, which are compared to the theoretical expectation for this particle size. Additionally, analysis of SAR curves yielded effective relaxation time.

  12. Dynamical properties of three terminal magnetic tunnel junctions: Spintronics meets spin-orbitronics

    SciTech Connect (OSTI)

    Tomasello, R.; Carpentieri, M.; Finocchio, G.

    2013-12-16

    This Letter introduces a micromagnetic model able to characterize the magnetization dynamics in three terminal magnetic tunnel junctions, where the effects of spin-transfer torque and spin-orbit torque are taken into account. Our results predict that the possibility to separate electrically those two torque sources is very promising from a technological point of view for both next generation of nanoscale spintronic oscillators and microwave detectors. A scalable synchronization scheme based on the parallel connection of those three terminal devices is also proposed.

  13. Synchronizing quantum clocks with classical one-way communication: Bounds on the generated entropy

    E-Print Network [OSTI]

    Dominik Janzing; Thomas Beth

    2003-06-03

    We describe separable joint states on bipartite quantum systems that cannot be prepared by any thermodynamically reversible classical one-way communication protocol. We argue that the joint state of two synchronized microscopic clocks is always of this type when it is considered from the point of view of an ``ignorant'' observer who is not synchronized with the other two parties. We show that the entropy generation of a classical one-way synchronization protocol is at least \\Delta S = \\hbar^2/(4\\Delta E \\Delta t)^2 if \\Delta t is the time accuracy of the synchronism and \\Delta E is the energy bandwidth of the clocks. This dissipation can only be avoided if the common time of the microscopic clocks is stored by an additional classical clock. Furthermore, we give a similar bound on the entropy cost for resetting synchronized clocks by a classical one-way protocol. The proof relies on observations of Zurek on the thermodynamic relevance of quantum discord. We leave it as an open question whether classical multi-step protocols may perform better. We discuss to what extent our results imply problems for classical concepts of reversible computation when the energy of timing signals is close to the Heisenberg limit.

  14. Sustainable Developmentwww.st-andrews.ac.uk/sasi

    E-Print Network [OSTI]

    Brierley, Andrew

    108 Sustainable Developmentwww.st-andrews.ac.uk/sasi Sustainable Development Degree options MSc (One Year) Coursework & 15,000-word Dissertation Sustainable Development MSc (Two Years) Coursework Sustainable Development Postgraduate Certificate (One Semester) Coursework Sustainable Development MRes (One

  15. Cognitive Radio Network {swjang, sbahk}@netlab.snu.ac.kr

    E-Print Network [OSTI]

    Bahk, Saewoong

    2010 Cognitive Radio Network , , {swjang, sbahk}@netlab.snu.ac.kr Analysis of Average Opportunities in Cognitive Radio Networks Seowoo Jang, Saewoong Bahk INMC, EECS, Seoul National University Cognitive Radio Network . Primary user

  16. Adjustable Speed AC Motor Drives-Applications Problems 

    E-Print Network [OSTI]

    Enjeti, P.

    1997-01-01

    Adjustable speed AC drives have become the preferred choice in many industrial applications where controlled speed is required. At the same time, the maturing of the technology and the availability of fast and efficient ...

  17. Alameda-Contra Costa Transit District (AC Transit) Fuel Cell...

    Broader source: Energy.gov (indexed) [DOE]

    provides an evaluation of three prototype fuel cell-powered transit buses operating at AC Transit in Oakland, California, and six baseline diesel buses similar in design to the...

  18. Microfluidics {sjauh, btzhang}@bi.snu.ac.kr

    E-Print Network [OSTI]

    Microfluidics {sjauh, btzhang}@bi.snu.ac.kr Solving Shortest Path Problems Using Microfluidics Sahng-Joon Auh and Byoung-Tak Zhang Biointelligence Lab, School of Computer Science and Engineering Seoul National University . microfluidics MEMS

  19. Bond graph models of electromechanical systems. The AC generator case

    E-Print Network [OSTI]

    Batlle, Carles

    Bond graph models of electromechanical systems. The AC generator case Carles Batlle Department. After reviewing electromechanical energy conversion and torque gener- ation, the core element present in any electromechanical system is introduced, and the corresponding electrical and mechanical ports

  20. DE-AC05-00OR22800

    National Nuclear Security Administration (NNSA)

    DE-AC05-00OR22800 DOE DIRECTIVES DOE Directives can be found at the following Internet address: https:www.directives.doe.gov REQUIRED COMPLIANCE DOCUMENT DATE TITLE...

  1. www.kent.ac.uk/is/ Information Services

    E-Print Network [OSTI]

    Kent, University of

    System website: www.kent.ac.uk/cmsds-local/ Installing Putty Download it from the web 1. www close to each other. A dark cursor will not show on a dark background. Ideally make either

  2. November 2013 www.kent.ac.uk/library

    E-Print Network [OSTI]

    Banaji,. Murad

    November 2013 www.kent.ac.uk/library Information Services Templeman Library SCONUL Access scheme) to the Templeman Library. I am a registered member of the Sconul Access scheme and hold a valid card. If given ............................... ................................................................................................................ Home library

  3. Nanostructured magnetic materials

    E-Print Network [OSTI]

    Chan, Keith T.

    2011-01-01

    Magnetism and Magnetic Materials Conference, Atlanta, GA (Nanostructured Magnetic Materials by Keith T. Chan Doctor ofinduced by a Si-based material occurs at a Si/Ni interface

  4. Magnetic Interactions in Ball-Milled Spinel Ferrites

    E-Print Network [OSTI]

    Goya, Gerardo F

    2011-01-01

    Spinel Fe3O4 nanoparticles have been produced through ball milling in methyl-alcohol (CH3OH), aiming to obtain samples with similar average particle sizes and different interparticle interactions. Three samples having Fe3O4/CH3(OH) mass ratios R of 3 %, 10 % and 50 % wt. were milled for several hours until particle size reached a steady value ( ~ 7-10 nm). A detailed study of static and dynamic magnetic properties has been undertaken by measuring magnetization, ac susceptibility and M\\"ossbauer data. As expected for small particles, the Verwey transition was not observed, but instead superparamagnetic (SPM) behavior was found with transition to a blocked state at TB ~ 10-20 K. Spin disorder of the resulting particles, independent of its concentration, was inferred from the decrease of saturation magnetization MS at low temperatures. For samples having 3% wt. of magnetic particles, dynamic ac susceptibility measurements show a thermally activated Arrhenius dependence of the blocking temperature with applied f...

  5. Development of an AC Module System: Final Technical Report

    SciTech Connect (OSTI)

    Suparna Kadam; Miles Russell

    2012-06-15

    The GreenRay Inc. program focused on simplifying solar electricity and making it affordable and accessible to the mainstream population. This was accomplished by integrating a solar module, micro-inverter, mounting and monitoring into a reliable, 'plug and play' AC system for residential rooftops, offering the following advantages: (1) Reduced Cost: Reduction in installation labor with fewer components, faster mounting, faster wiring. (2) Maximized Energy Production: Each AC Module operates at its maximum, reducing overall losses from shading, mismatch, or module downtime. (3) Increased Safety. Electrical and fire safety experts agree that AC Modules have significant benefits, with no energized wiring or live connections during installation, maintenance or emergency conditions. (4) Simplified PV for a Broader Group of Installers. Dramatic simplification of design and installation of a solar power system, enabling faster and more efficient delivery of the product into the market through well-established, mainstream channels. This makes solar more accessible to the public. (5) Broadened the Rooftop Market: AC Modules enable solar for many homes that have shading, split roofs, or obstructions. In addition, due to the smaller building block size of 200W vs. 1000W, homeowners with budget limitations can start small and add to their systems over time. Through this DOE program GreenRay developed the all-in-one AC Module system with an integrated PV Module and microinverter, custom residential mounting and performance monitoring. Development efforts took the product from its initial concept, through prototypes, to a commercial product sold and deployed in the residential market. This pilot deployment has demonstrated the technical effectiveness of the AC Module system in meeting the needs and solving the problems of the residential market. While more expensive than the traditional central inverter systems at the pilot scale, the economics of AC Modules become more and more favorable as the product matures and is made in high volumes. GreenRay's early customers have been highly enthusiastic about the AC Module system benefits.

  6. Chaotic magnetization dynamics in single-crystal thin-film structures

    SciTech Connect (OSTI)

    Shutyi, A. M., E-mail: shuty@mail.ru; Sementsov, D. I. [Ulyanovsk State University (Russian Federation)

    2009-01-15

    The nonlinear dynamics of homogeneously precessing magnetization in perpendicularly magnetized single-crystal films has been investigated in a wide range of ac field frequencies on the basis of a numerical solution to the Landau-Lifshitz equation and construction of the spectrum of Lyapunov exponents. The conditions for implementing and specific features of chaotic dynamic modes are revealed for films of three basic crystallographic orientations: (100), (110), and (111). It is shown that chaotic precession modes can be controlled using external magnetic fields. Time analogs of the Poincare section of chaotic mode trajectories are considered.

  7. Magnets and Power Supplies

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

    Up: APS Storage Ring Parameters Previous: Longitudinal bunch profile and Magnets and Power Supplies Dipole Magnets and Power Supplies Value Dipole Number 80+1 No. of power...

  8. SUPERCONDUCTING MAGNETIC ENERGY STORAGE

    E-Print Network [OSTI]

    Hassenzahl, W.

    2011-01-01

    Superconducting 30-MJ Energy Storage Coil", Proc. 19 80 ASC,Superconducting Magnetic Energy Storage Plant", IEEE Trans.SlIperconducting Magnetic Energy Storage Unit", in Advances

  9. http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html

    E-Print Network [OSTI]

    2011 P6 http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html web #12;http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html () ( #12;http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html X MeV X Astro-H 2013 TeV10m) #12;http://www-cr.scphys.kyoto-u.ac.jp/gakubu/P6.html 2010 ASTRO-H CCD X (2) () (2) (2

  10. cwnam@netlab.snu.ac.kr {jinyo.chung, yongsuk}@samsung.com sbahk@netlab.snu.ac.kr Detection of Alien Piconet using Preamble Information

    E-Print Network [OSTI]

    Bahk, Saewoong

    @netlab.snu.ac.kr Detection of Alien Piconet using Preamble Information Changwon Nam*, Jinyong Chung+, Yongsuk Kim+, Saewoong

  11. Transmission of information and synchronization in a pair of coupled chaotic circuits: an experimental overview

    E-Print Network [OSTI]

    M. S. Baptista; S. P. Garcia; S. K. Dana; J. Kurths

    2008-11-18

    We propose a rationale for experimentally studying the intricate relationship between the rate of information transmission and synchronization level in active networks, applying theoretical results recently proposed. We consider two non-identical coupled Chua's circuit with non-identical coupling strengths in order to illustrate the proceeding for experimental scenarios of very few data points coming from highly non-coherent coupled systems, such that phase synchronization can only be detected by methods that do not rely explicitely on the calculation of the phase. A relevant finding is to show that for the coupled Chua's circuit, the larger the level of synchronization the larger the rate of information exchanged between both circuits. We further validate our findings with data from numerical simulations, and discuss an extension to arbitrarily large active networks.

  12. Control of synchronization in coupled neural systems by time-delayed feedback

    E-Print Network [OSTI]

    Philipp Hoevel; Markus A. Dahlem; Eckehard Schoell

    2008-09-04

    We discuss the synchronization of coupled neurons which are modelled as FitzHugh-Nagumo systems. As smallest entity in a larger network, we focus on two diffusively coupled subsystems, which can be interpreted as two mutually interacting neural populations. Each system is prepared in the excitable regime and subject to independent random fluctuations. In order to modify their cooperative dynamics, we apply a local external stimulus in form of an extended time-delayed feedback loop that involves multiple delays weighted by a memory parameter and investigate if local control applied to a subsystem can allow one to steer the global cooperative dynamics. Depending on the choice of this new control parameter, we investigate different measures to quantify the influence on synchronization: ratio of interspike intervals, power spectrum, interspike interval distribution, and phase synchronization intervals. We show that the control method is more robust for increasing memory parameter.

  13. The role of intermediaries in the synchronization of pulse-coupled oscillators

    E-Print Network [OSTI]

    Rodrigo A. García; Nicolás Rubido; Arturo C. Marti; Cecilia Cabeza

    2014-09-03

    The role of intermediaries in the synchronization of small groups of light controlled oscillators (LCO) is addressed. A single LCO is a two-time-scale phase oscillator. When pulse-coupling two LCOs, the synchronization time decreases monotonously as the coupling strength increases, independent of the initial conditions and frequency detuning. In this work we study numerically the effects that a third LCO induces to the collective behavior of the system. We analyze the new system by dealing with directed heterogeneous couplings among the units. We report a novel and robust phenomenon, absent when coupling two LCOs, which consists of a discontinuous relationship between the synchronization time and coupling strength or initial conditions. The mechanism responsible for the appearance of such discontinuities is discussed.

  14. Occam's Quantum Strop: Synchronizing and Compressing Classical Cryptic Processes via a Quantum Channel

    E-Print Network [OSTI]

    J. R. Mahoney; C. Aghamohammadi; J. P. Crutchfield

    2015-08-11

    A stochastic process's statistical complexity stands out as a fundamental property: the minimum information required to synchronize one process generator to another. How much information is required, though, when synchronizing over a quantum channel? Recent work demonstrated that representing causal similarity as quantum state-indistinguishability provides a quantum advantage. We generalize this to synchronization and offer a sequence of constructions that exploit extended causal structures, finding substantial increase of the quantum advantage. We demonstrate that maximum compression is determined by the process's cryptic order---a classical, topological property closely allied to Markov order, itself a measure of historical dependence. We introduce an efficient algorithm that computes the quantum advantage and close noting that the advantage comes at a cost---one trades off prediction for generation complexity.

  15. Femtosecond all-optical synchronization of an X-ray free-electron laser

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

    Schulz, S.; Grguraš, I.; Behrens, C.; Bromberger, H.; Costello, J. T.; Czwalinna, M. K.; Felber, M.; Hoffmann, M. C.; Ilchen, M.; Liu, H. Y.; et al

    2015-01-20

    Many advanced applications of X-ray free-electron lasers require pulse durations and time resolutions of only a few femtoseconds. To generate these pulses and to apply them in time-resolved experiments, synchronization techniques that can simultaneously lock all independent components, including all accelerator modules and all external optical lasers, to better than the delivered free-electron laser pulse duration, are needed. Here we achieve all-optical synchronization at the soft X-ray free-electron laser FLASH and demonstrate facility-wide timing to better than 30 fs r.m.s. for 90 fs X-ray photon pulses. Crucially, our analysis indicates that the performance of this optical synchronization is limited primarilymore »by the free-electron laser pulse duration, and should naturally scale to the sub-10 femtosecond level with shorter X-ray pulses.« less

  16. Error field and magnetic diagnostic modeling for W7-X

    SciTech Connect (OSTI)

    Lazerson, Sam A.; Gates, David A.; NEILSON, GEORGE H.; OTTE, M.; Bozhenkov, S.; Pedersen, T. S.; GEIGER, J.; LORE, J.

    2014-07-01

    The prediction, detection, and compensation of error fields for the W7-X device will play a key role in achieving a high beta (? = 5%), steady state (30 minute pulse) operating regime utilizing the island divertor system [1]. Additionally, detection and control of the equilibrium magnetic structure in the scrape-off layer will be necessary in the long-pulse campaign as bootstrapcurrent evolution may result in poor edge magnetic structure [2]. An SVD analysis of the magnetic diagnostics set indicates an ability to measure the toroidal current and stored energy, while profile variations go undetected in the magnetic diagnostics. An additional set of magnetic diagnostics is proposed which improves the ability to constrain the equilibrium current and pressure profiles. However, even with the ability to accurately measure equilibrium parameters, the presence of error fields can modify both the plasma response and diverter magnetic field structures in unfavorable ways. Vacuum flux surface mapping experiments allow for direct measurement of these modifications to magnetic structure. The ability to conduct such an experiment is a unique feature of stellarators. The trim coils may then be used to forward model the effect of an applied n = 1 error field. This allows the determination of lower limits for the detection of error field amplitude and phase using flux surface mapping. *Research supported by the U.S. DOE under Contract No. DE-AC02-09CH11466 with Princeton University.

  17. Applications of neural networks and other machine learning techniques. Contact: Neil Davey, n.davey@herts.ac.uk, Yi Sun, y.2.sun@herts.ac.uk

    E-Print Network [OSTI]

    Hertfordshire, University of

    .davey@herts.ac.uk, Yi Sun, y.2.sun@herts.ac.uk We are currently involved in three collaborative projects, investigating. This is a collaboration with our School of Pharmacy. A description of our work can be found at: http://homepages.feis.herts.ac.uk/~nngroup/pubs/papers/Sun

  18. An integral manifold approach to reduced order dynamic modeling of synchronous machines

    SciTech Connect (OSTI)

    Sauer, P.W.; Ahmed-Zaid, S.; Kokotovic, P.V.

    1988-02-01

    The concept of integral manifolds is used to systematically create improved reduced order models of synchronous machines. The approach is illustrated through a detailed example of a single machine connected to an infinite bus. The example shows the advantages of the manifold approach and also clarifies several issues about reduced order models of synchronous machines. The basic objective of the method is to include the effects of more complex models without actually including the additional differential equations. This is illustrated by including the effects of stator transients and damper windings on the swing equation without including the differential equations.

  19. A new method for determining the armature leakage reactance of synchronous machines

    SciTech Connect (OSTI)

    El-Serafi, A.M.; Wu, J. (Power Systems Research Group, Dept. of Electrical Engineering, Univ. of Saskatchewan, Saskatoon (CA))

    1991-03-01

    This paper presents a new method for determining the armature leakage reactance of synchronous machines. In this method, the terminal voltage/armature current characteristic with the machine unloaded and unexcited is needed together with the open-circuit characteristic of the machine. The armature leakage reactance is derived from these two curves using iterative technique. The armature leakage reactances of five synchronous machines of different designs are obtained using the proposed method. Their values are compared with those of the Potier reactance of these machines measured at various terminal voltages.

  20. Synchronization and phase redistribution in self-replicating populations of coupled oscillators and excitable elements

    E-Print Network [OSTI]

    Wen Yu; Kevin B. Wood

    2015-03-19

    We study the dynamics of phase synchronization in growing populations of discrete phase oscillatory systems when the division process is coupled to the distribution of oscillator phases. Using mean field theory, linear stability analysis, and numerical simulations, we demonstrate that coupling between population growth and synchrony can lead to a wide range of dynamical behavior, including extinction of synchronized oscillations, the emergence of asynchronous states with unequal state (phase) distributions, bistability between oscillatory and asynchronous states or between two asynchronous states, a switch between continuous (supercritical) and discontinuous (subcritical) transitions, and modulation of the frequency of bulk oscillations.

  1. Carrier phase synchronization system for improved amplitude modulation and television broadcast reception

    DOE Patents [OSTI]

    Smith, Stephen F. (Loudon, TN) [Loudon, TN; Moore, James A. (Powell, TN) [Powell, TN

    2009-09-08

    Systems and methods are described for carrier phase synchronization for improved AM and TV broadcast reception. A method includes synchronizing the phase of a carrier frequency of a broadcast signal with the phase of a remote reference frequency. An apparatus includes a receiver to detect the phase of a reference signal; a phase comparator coupled to the reference signal-phase receiver; a voltage controlled oscillator coupled to the phase comparator; and a phase-controlled radio frequency output coupled to the voltage controlled oscillator.

  2. Carrier phase synchronization system for improved amplitude modulation and television broadcast reception

    DOE Patents [OSTI]

    Smith, Stephen F. (Loudon, TN); Moore, James A. (Powell, TN)

    2011-02-01

    Systems and methods are described for carrier phase synchronization for improved AM and TV broadcast reception. A method includes synchronizing the phase of a carrier frequency of a broadcast signal with the phase of a remote reference frequency. An apparatus includes a receiver to detect the phase of a reference signal; a phase comparator coupled to the reference signal-phase receiver; a voltage controlled oscillator coupled to the phase comparator; and a phase-controlled radio frequency output coupled to the voltage controlled oscillator.

  3. Synchronization efficiency in coupled stochastic oscillators: The role of connection topology

    E-Print Network [OSTI]

    G. Reenaroy Devi; R. K. Brojen Singh; Ram Ramaswamy

    2015-04-02

    We study the efficiency of synchronization in ensembles of identical coupled stochastic oscillator systems. By deriving a chemical Langevin equation, we measure the rate at which the systems synchronize. The rate at which the difference in the Hilbert phases of the systems evolve provides a suitable order parameter, and a 2--dimensional recurrence plot further facilitates the analysis of stochastic synchrony. We find that a global mean--field coupling effects the most rapid approach to global synchrony, and that when the number of "information carrying" molecular species increases, the rate of synchrony increases. The Langevin analysis is complemented by numerical simulations.

  4. Emergence of zero-lag synchronization in generic mutually coupled chaotic systems

    E-Print Network [OSTI]

    Meital Zigzag; Maria Butkovski; Anja Englert; Wolfgang Kinzel; Ido Kanter

    2008-11-25

    Zero-lag synchronization (ZLS) is achieved in a very restricted mutually coupled chaotic systems, where the delays of the self-coupling and the mutual coupling are identical or fulfil some restricted ratios. Using a set of multiple self-feedbacks we demonstrate both analytically and numerically that ZLS is achieved for a wide range of mutual delays. It indicates that ZLS can be achieved without the knowledge of the mutual distance between the communicating partners and has an important implication in the possible use of ZLS in communications networks as well as in the understanding of the emergence of such synchronization in the neuronal activities.

  5. Time Synchronization Attack in Smart Grid-Part I: Impact and Analysis

    E-Print Network [OSTI]

    Zhang, Zhenghao; Dimitrovski, Aleksandar D; Li, Husheng

    2012-01-01

    Many operations in power grids, such as fault detection and event location estimation, depend on precise timing information. In this paper, a novel Time Synchronization Attack (TSA) is proposed to attack the timing information in smart grid. Since many applications in smart grid utilize synchronous measurements and most of the measurement devices are equipped with global positioning system (GPS) for precise timing, it is highly probable to attack the measurement system by spoofing the GPS. The effectiveness of TSA is demonstrated for three applications of phasor measurement unit (PMU) in smart grid, namely transmission line fault detection, voltage stability monitoring and event locationing. The validity of TSA is demonstrated by numerical simulations.

  6. Distinct magnetic signatures of fractional vortex configurations in multiband superconductors

    SciTech Connect (OSTI)

    Silva, R. M. da; Domínguez, D.; Aguiar, J. Albino

    2014-12-08

    Vortices carrying fractions of a flux quantum are predicted to exist in multiband superconductors, where vortex core can split between multiple band-specific components of the superconducting condensate. Using the two-component Ginzburg-Landau model, we examine such vortex configurations in a two-band superconducting slab in parallel magnetic field. The fractional vortices appear due to the band-selective vortex penetration caused by different thresholds for vortex entry within each band-condensate, and stabilize near the edges of the sample. We show that the resulting fractional vortex configurations leave distinct fingerprints in the static measurements of the magnetization, as well as in ac dynamic measurements of the magnetic susceptibility, both of which can be readily used for the detection of these fascinating vortex states in several existing multiband superconductors.

  7. CS61C L23 Synchronous Digital Systems (1)! Garcia, Fall 2011 UCB! ! !Lecturer SOE Dan Garcia!

    E-Print Network [OSTI]

    California at Irvine, University of

    !! CS61C L23 Synchronous Digital Systems (2)! Garcia, Fall 2011 © UCB! New-School Machine StructuresCS61C L23 Synchronous Digital Systems (1)! Garcia, Fall 2011 © UCB! ! !Lecturer SOE Dan Garcia! ! !www.cs.berkeley.edu/~ddgarcia inst.eecs.berkeley.edu/~cs61c CS61C : Machine Structures Lecture 23

  8. CS61C L23 Synchronous Digital Systems (1)! Garcia, Fall 2011 UCB! ! !Lecturer SOE Dan Garcia!

    E-Print Network [OSTI]

    California at Irvine, University of

    !! #12;CS61C L23 Synchronous Digital Systems (2)! Garcia, Fall 2011 © UCB! New-School MachineCS61C L23 Synchronous Digital Systems (1)! Garcia, Fall 2011 © UCB! ! !Lecturer SOE Dan Garcia! ! !www.cs.berkeley.edu/~ddgarcia inst.eecs.berkeley.edu/~cs61c CS61C : Machine Structures Lecture 23

  9. International Journal of Wireless Mobile Networks (IJWMN), Vol.2, No.2, May 2010 Energy Efficient Global Clock Synchronization

    E-Print Network [OSTI]

    Namboodiri, Vinod

    convergence but consume a lot of energy per round of synchronization. On the other hand, smaller powers consume little energy per round, but convergence is very slow requiring a lot of rounds to achieve of convergence and energy consumed per round of synchronization. A centralized algorithm is presented that uses

  10. Stereo Vision Based Navigation for Sun-Synchronous Exploration Chris P. Urmson, M. Bernardine Dias, Reid G. Simmons

    E-Print Network [OSTI]

    Simmons, Reid

    -synchronous robot. Sun-synchrony is a concept that will enable exploration missions by solar- powered roversStereo Vision Based Navigation for Sun-Synchronous Exploration Chris P. Urmson, M. Bernardine Dias, reids}@ri.cmu.edu Abstract This paper describes the navigation system used on a prototype sun

  11. Synchronization of a class of master-slave non-autonomous chaotic systems with parameter mismatch via sinusoidal feedback control

    E-Print Network [OSTI]

    Jianping Cai; Mihua Ma; Xiaofeng Wu

    2009-08-22

    In this paper we investigate a master-slave synchronization scheme of two n-dimensional non-autonomous chaotic systems coupled by sinusoidal state error feedback control, where parameter mismatch exists between the external harmonic excitation of master system and that of slave one. A concept of synchronization with error bound is introduced due to parameter mismatch, and then the bounds of synchronization error are estimated analytically. Some synchronization criteria are firstly obtained in the form of matrix inequalities by the Lyapunov direct method, and then simplified into some algebraic inequalities by the Gerschgorin disc theorem. The relationship between the estimated synchronization error bound and system parameters reveals that the synchronization error can be controlled as small as possible by increasing the coupling strength or decreasing the magnitude of mismatch. A three-dimensional gyrostat system is chosen as an example to verify the effectiveness of these criteria, and the estimated synchronization error bounds are compared with the numerical error bounds. Both the theoretical and numerical results show that the present sinusoidal state error feedback control is effective for the synchronization. Numerical examples verify that the present control is robust against amplitude or phase mismatch.

  12. Numerical and analytical studies on the complete synchronization of the variant of Murali-Lakshmanan-Chua circuits

    E-Print Network [OSTI]

    M. Daniel Sweetlin; G. Sivaganesh

    2015-05-05

    In this paper we present numerical and analytical studies on the complete synchronization phenomena exhibited by unidirectionally coupled two variant of Murali-Lakshmanan-Chua circuits. The transition of the coupled system from an unsynchronized state to a state of complete synchronization under the influence of the coupling parameter is observed through phase portraits obtained numerically and analytically.

  13. Discrete Calderon's projections on parallelepipeds and their application to computing exterior magnetic fields for FRC plasmas q

    E-Print Network [OSTI]

    Tsynkov, Semyon V.

    magnetic fields for FRC plasmas q E. Kansa a , U. Shumlak a,b , S. Tsynkov a,c, a Computational Sciences the plasma itself occupies a bounded region (within the FRC coils), the field extends from this region all October 2012 Keywords: Field reversed configuration (FRC) Single fluid magnetohydrodynamics (MHD) Quasi

  14. Controlling the crystallization and magnetic properties of melt-spun Pr2Fe14B -Fe nanocomposites by Joule heating

    E-Print Network [OSTI]

    Wang, Zhong L.

    Controlling the crystallization and magnetic properties of melt-spun Pr2Fe14BÕ -Fe nanocomposites by Joule heating Z. Q. Jin School of Materials Science and Engineering, Georgia Institute of Technology by means of ac Joule heating while simultaneously monitoring room-temperature electrical resistance R

  15. System and method for determining stator winding resistance in an AC motor using motor drives

    DOE Patents [OSTI]

    Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

    2013-02-26

    A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

  16. GABAergic neurones control the activity of spatial coding and synchronous network activity in the hippocampal-entorhinal formation thereby affecting spatial learning

    E-Print Network [OSTI]

    Fukai, Tomoki

    GABAergic neurones control the activity of spatial coding and synchronous network activity Abstract GABAergic interneurons are crucially involved in the generation and maintenance of rhythmic synchronous activity in many forebrain regions, including the hippocampal-entorhinal formation. Genetic

  17. Evolving Globally Synchronized Cellular Automata Rajarshi Das1,2, James P. Crutch eld3, Melanie Mitchell1, and James E. Hanson1

    E-Print Network [OSTI]

    Crutchfield, Jim

    , typically phase defects between synchronous regions, are designed by the evolu- tionary process to resolve of the Dictyostelium slime mold 4], the morphogenesis of embryonicstructures in early development 11], the synchronized

  18. Effect of Inter-Modular Connection on Fast Sparse Synchronization in Clustered Small-World Neural Networks

    E-Print Network [OSTI]

    Kim, Sang-Yoon

    2015-01-01

    We consider a clustered network with small-world sub-networks of inhibitory fast spiking interneurons, and investigate the effect of inter-modular connection on emergence of fast sparsely synchronized rhythms by varying both the inter-modular coupling strength $J_{inter}$ and the average number of inter-modular links per interneuron $M_{syn}^{(inter)}$. In contrast to the case of non-clustered networks, two kinds of sparsely synchronized states such as modular and global synchronization are found. For the case of modular sparse synchronization, the population behavior reveals the modular structure, because the intra-modular dynamics of sub-networks make some mismatching. On the other hand, in the case of global sparse synchronization, the population behavior is globally identical, independently of the cluster structure, because the intra-modular dynamics of sub-networks make perfect matching. We introduce a realistic cross-correlation modularity measure, representing the matching-degree between the instantane...

  19. University , DE{AC020{76{CHO{3073.

    E-Print Network [OSTI]

    Zakharov, Leonid E.

    PLASMA PHYSICS LABORATORY PPPL 3 #12; OUTLINE 1. Magnetic propulsion of liquid lithium. 2. Lithium Walls, Princeton NJ PRINCETON PLASMA PHYSICS LABORATORY PPPL 4 #12; 1 Magnetic propulsion of liquid lithium Goto PHYSICS LABORATORY PPPL 5 #12; 1 Magnetic propulsion of liquid lithium (cont.) There 3 magnetic Reynolds

  20. Spatiotemporal synchronization of drift waves in a magnetron sputtering plasma

    SciTech Connect (OSTI)

    Martines, E.; Zuin, M.; Cavazzana, R.; Antoni, V.; Serianni, G.; Spolaore, M.; Vianello, N. [Consorzio RFX, Padova (Italy); Adámek, J. [Institute of Plasma Physics AS CR, Prague (Czech Republic)

    2014-10-15

    A feedforward scheme is applied for drift waves control in a magnetized magnetron sputtering plasma. A system of driven electrodes collecting electron current in a limited region of the explored plasma is used to interact with unstable drift waves. Drift waves actually appear as electrostatic modes characterized by discrete wavelengths of the order of few centimeters and frequencies of about 100 kHz. The effect of external quasi-periodic, both in time and space, travelling perturbations is studied. Particular emphasis is given to the role played by the phase relation between the natural and the imposed fluctuations. It is observed that it is possible by means of localized electrodes, collecting currents which are negligible with respect to those flowing in the plasma, to transfer energy to one single mode and to reduce that associated to the others. Due to the weakness of the external action, only partial control has been achieved.

  1. Magnetic Damping For Maglev

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

    Zhu, S.; Cai, Y.; Rote, D.M.; Chen, S.S.

    1998-01-01

    Magnetic damping is one of the important parameters that control the response and stability of maglev systems. An experimental study to measure magnetic damping directly is presented. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters, such as conductivity, gap, excitation frequency, and oscillation amplitude, on magnetic damping. The experimental technique is capable of measuring all of the magnetic damping coefficients, some of which cannot be measured indirectly.

  2. The Thrifty Barrier: Energy-Aware Synchronization in Shared-Memory Multiprocessors

    E-Print Network [OSTI]

    Martínez, José F.

    - proach to saving energy in parallel applications that exhibit barrier synchronization imbalance. Threads extensions to achieve timely wake-up of these dor- mant threads, maximizing energy savings while minimizing a few threads. In that case, slowing down threads not on the critical path to save energy may not affect

  3. Comparing Energy and Latency of Asynchronous and Synchronous NoCs for Embedded SoCs

    E-Print Network [OSTI]

    Stevens, Ken

    -on-chip (NoC) of both these classes should be optimized for minimal energy usage while meeting the predictedComparing Energy and Latency of Asynchronous and Synchronous NoCs for Embedded SoCs Daniel Gebhardt School of Computing University of Utah gebhardt@cs.utah.edu Junbok You Kenneth S. Stevens Dept

  4. Voltage Stability and Frequency Synchronization of Weak Power Distribution Networks with Inverter-Based

    E-Print Network [OSTI]

    Lemmon, Michael

    a part of microgrids, are incorporated to improve power quality and reliability when disruptions happen of microgrids [13], together with oth- er generation, storage and load units. These microgrid- s are installedVoltage Stability and Frequency Synchronization of Weak Power Distribution Networks with Inverter

  5. Hardware Implementation of a High Speed Self-Synchronizing Cipher Mode

    E-Print Network [OSTI]

    Heys, Howard

    in a communication channel. The mechanism of SCFB mode resembles output feedback (OFB) mode and cipher feedback (CFB) mode. However it has self synchronization that OFB mode does not and has higher efficiency than CFB@mun.ca cipher work as a stream cipher. Output Feedback (OFB) mode, Cipher Feedback (CFB) mode and Counter (CTR

  6. Dead-time optimized time-correlated photon counting instrument with synchronized, independent timing channels

    E-Print Network [OSTI]

    Enderlein, Jörg

    Dead-time optimized time-correlated photon counting instrument with synchronized, independent timing channels Michael Wahla and Hans-Jürgen Rahn PicoQuant GmbH, Rudower Chaussee 29, D-12489 Berlin December 2006; accepted 19 February 2007; published online 23 March 2007 Time-correlated single photon

  7. Time Synchronization between SOKUIKI Sensor and Host Computer using Alexander CARBALLO, Yoshitaka HARA, Hirohiko KAWATA,

    E-Print Network [OSTI]

    Ohya, Akihisa

    Time Synchronization between SOKUIKI Sensor and Host Computer using Timestamps Alexander CARBALLO Institute of Technology Abstract: Time is crucial in applications such as sensor data fusion, autonomous.0 protocol of SOKUIKI sensor allows acquiring time values by timestamping range readings. Our work consists

  8. Synchronization of Washing Operations with Droplet Routing for Cross-Contamination Avoidance in Digital Microfluidic

    E-Print Network [OSTI]

    Chakrabarty, Krishnendu

    Synchronization of Washing Operations with Droplet Routing for Cross-Contamination Avoidance in many areas of biochemistry and biomedical sciences. Since cross-contamination between droplets-droplet routing with sample/reagent drop- let-routing steps by controlling the arrival order of droplets at cross-contamination

  9. Output Synchronization of Multi-Agent Systems with Event-Driven Communication: Communication Delay and

    E-Print Network [OSTI]

    Antsaklis, Panos

    Output Synchronization of Multi-Agent Systems with Event-Driven Communication: Communication Delay-Agent Systems with Event-Driven Communication: Communication Delay and Signal Quantization Han Yu, Student is an important extension of applying event-driven communication to control of multi-agent systems, especially

  10. Breaking a secure communication scheme based on the phase synchronization of chaotic systems

    E-Print Network [OSTI]

    G. Alvarez; F. Montoya; G. Pastor; M. Romera

    2003-11-20

    A security analysis of a recently proposed secure communication scheme based on the phase synchronization of chaotic systems is presented. It is shown that the system parameters directly determine the ciphertext waveform, hence it can be readily broken by parameter estimation of the ciphertext signal.

  11. Synchronization and Communication with Chaotic Time-Delay Electronic Circuit Systems

    E-Print Network [OSTI]

    Anlage, Steven

    Synchronization and Communication with Chaotic Time-Delay Electronic Circuit Systems David T simulation. Circuit implementation of Mackey- Glass delayed system. #12;)( )(1 )()( tbx tx tax dt tdx n - -+ - = 2.0=a 1.0=b 10=n The Mackey-Glass System The Mackey-Glass mathematical model1: a delay differential

  12. Synchronization and portfolio performance of threatened salmon Jonathan W. Moore1

    E-Print Network [OSTI]

    LETTER Synchronization and portfolio performance of threatened salmon Jonathan W. Moore1 , Michelle Marine Fisheries Service, Seattle, WA 98110, USA 2 School of Aquatic and Fishery Sciences, University salmon decreased risk-adjusted portfolio performance (the ratio of port- folio productivity to variance

  13. Synchronous Ultra-Wide Band Wireless Sensors Networks for oil and gas exploration

    E-Print Network [OSTI]

    Savazzi, Stefano

    Synchronous Ultra-Wide Band Wireless Sensors Networks for oil and gas exploration Stefano Savazzi1 of new oil and gas reservoir. Seismic exploration requires a large number (500 ÷ 2000 nodes, MAC and network layer to develop wireless sensors networks tailored for oil (and gas) exploration

  14. On Utility Accrual Processor Scheduling with Wait-Free Synchronization for Embedded Real-Time Software

    E-Print Network [OSTI]

    Ravindran, Binoy

    On Utility Accrual Processor Scheduling with Wait-Free Synchronization for Embedded Real-Time Software ABSTRACT We present the first wait-free utility accrual (UA) real-time scheduling algorithms for embedded real-time systems. UA scheduling algorithms allow application activities to be sub- ject to time/utility

  15. Parks Research Forum of Ontario ~ 197 ~ Long-term population estimates and synchronous

    E-Print Network [OSTI]

    Blouin-Demers, Gabriel

    Parks Research Forum of Ontario ~ 197 ~ Long-term population estimates and synchronous variation in two populations of black rat snakes (Elaphe obsoleta) in Eastern Ontario Marie-Ange Gravel and Gabriel Ontario. The Jolly-Seber method was used to estimate population size. The population sizes tended to vary

  16. Leader/Follower synchronization of satellite attitude without angular velocity measurements

    E-Print Network [OSTI]

    Gravdahl, Jan Tommy

    Leader/Follower synchronization of satellite attitude without angular velocity measurements Anne angular velocity measurements are not available. Nonlinear observers are used to estimate the angular law without angular velocity measurements for a single spacecraft and in [8] an output feedback

  17. Synchronization Algorithms for Co-Simulation of Power Grid and Communication Networks

    SciTech Connect (OSTI)

    Ciraci, Selim; Daily, Jeffrey A.; Agarwal, Khushbu; Fuller, Jason C.; Marinovici, Laurentiu D.; Fisher, Andrew R.

    2014-09-11

    The ongoing modernization of power grids consists of integrating them with communication networks in order to achieve robust and resilient control of grid operations. To understand the operation of the new smart grid, one approach is to use simulation software. Unfortunately, current power grid simulators at best utilize inadequate approximations to simulate communication networks, if at all. Cooperative simulation of specialized power grid and communication network simulators promises to more accurately reproduce the interactions of real smart grid deployments. However, co-simulation is a challenging problem. A co-simulation must manage the exchange of informa- tion, including the synchronization of simulator clocks, between all simulators while maintaining adequate computational perfor- mance. This paper describes two new conservative algorithms for reducing the overhead of time synchronization, namely Active Set Conservative and Reactive Conservative. We provide a detailed analysis of their performance characteristics with respect to the current state of the art including both conservative and optimistic synchronization algorithms. In addition, we provide guidelines for selecting the appropriate synchronization algorithm based on the requirements of the co-simulation. The newly proposed algorithms are shown to achieve as much as 14% and 63% im- provement, respectively, over the existing conservative algorithm.

  18. Influence of noise on the synchronization of the stochastic Kuramoto model Bidhan Chandra Bag*

    E-Print Network [OSTI]

    Influence of noise on the synchronization of the stochastic Kuramoto model Bidhan Chandra Bag-Uhlenbeck OU 11,12 and non-Gaussian colored noise 13­15 . The model first introduced by Kuramoto 2 is one were modeled by an ensemble of coupled phase oscillators 6 . The Kuramoto model subject to a noise

  19. Programmable Orchestration of Time-Synchronized Events Across Decentralized Android Ensembles

    E-Print Network [OSTI]

    Cervesato, Iliano

    Programmable Orchestration of Time-Synchronized Events Across Decentralized Android Ensembles}@cmu.edu Abstract--Orchestrating a time sensitive computation across an ad hoc ensemble of Android devicesMingle, a distributed logic programming framework designed for orchestrating Android en- sembles, with explicit time

  20. Pe t al, (2009) ``Classification of Patte rns of EEG Synchronization for

    E-Print Network [OSTI]

    LeCun, Yann

    2009-01-01

    Mirowski Pe t al, (2009) ``Classification of Patte rns of EEG Synchronization for Se izure Pre Processin g #12; Mirowski P e al, (2009) ``Classifica ion of Pae rns of EEG Synchroniza ion for Se izure ive ime poin s, o form pae rns. Pa ie n ­spe cific machine le arning­base d classifie rs (suppor

  1. Clock synchronization for wireless sensor networks: a survey Bharath Sundararaman, Ugo Buy *, Ajay D. Kshemkalyani

    E-Print Network [OSTI]

    Scheuermann, Peter

    Clock synchronization for wireless sensor networks: a survey Bharath Sundararaman, Ugo Buy *, Ajay 2005; accepted 18 January 2005 Abstract Recent advances in micro-electromechanical (MEMS) technology have led to the development of small, low-cost, and low-power sensors. Wireless sensor networks (WSNs

  2. Emergence and Control of Multiphase Nonlinear Waves by Synchronization L. Friedland1

    E-Print Network [OSTI]

    Friedland, Lazar

    Emergence and Control of Multiphase Nonlinear Waves by Synchronization L. Friedland1 and A. G to the number of terms in the drive, while the frequencies and amplitudes of the emerging waveform proceed by presenting results of numerical simu- lations illustrating our ideas. Figure1 shows emergence

  3. Method and apparatus to debug an integrated circuit chip via synchronous clock stop and scan

    DOE Patents [OSTI]

    Bellofatto, Ralph E. (Ridgefield, CT); Ellavsky, Matthew R. (Rochester, MN); Gara, Alan G. (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Gooding, Thomas M. (Rochester, MN); Haring, Rudolf A. (Cortlandt Manor, NY); Hehenberger, Lance G. (Leander, TX); Ohmacht, Martin (Yorktown Heights, NY)

    2012-03-20

    An apparatus and method for evaluating a state of an electronic or integrated circuit (IC), each IC including one or more processor elements for controlling operations of IC sub-units, and each the IC supporting multiple frequency clock domains. The method comprises: generating a synchronized set of enable signals in correspondence with one or more IC sub-units for starting operation of one or more IC sub-units according to a determined timing configuration; counting, in response to one signal of the synchronized set of enable signals, a number of main processor IC clock cycles; and, upon attaining a desired clock cycle number, generating a stop signal for each unique frequency clock domain to synchronously stop a functional clock for each respective frequency clock domain; and, upon synchronously stopping all on-chip functional clocks on all frequency clock domains in a deterministic fashion, scanning out data values at a desired IC chip state. The apparatus and methodology enables construction of a cycle-by-cycle view of any part of the state of a running IC chip, using a combination of on-chip circuitry and software.

  4. Addressing the Challenges of Synchronization/Communication and Debugging Support in Hardware/Software Cosimulation

    E-Print Network [OSTI]

    Sherwood, Tim

    Addressing the Challenges of Synchronization/Communication and Debugging Support in Hardware component of ESL tools to simulate the hardware designs and software models concurrently. It helps of RTL memory from a software perspective. While cosimulation is fast compared to a complete hardware

  5. Synchronization and propagation of bursts in networks of coupled map neurons

    E-Print Network [OSTI]

    Rey Juan Carlos, Universidad

    Synchronization and propagation of bursts in networks of coupled map neurons Gouhei Tanakaa Institute of Physics. DOI: 10.1063/1.2148387 Some kinds of neurons are known to exhibit irregular bursting oscillations in response to a constant input cur- rent. Network behavior of such bursting neurons has been

  6. Western Wind and Solar Integration Study Phase 3A: Low Levels of Synchronous Generation

    SciTech Connect (OSTI)

    Miller, Nicholas W.; Leonardi, Bruno; D'Aquila, Robert; Clark, Kara

    2015-11-17

    The stability of the North American electric power grids under conditions of high penetrations of wind and solar is a significant concern and possible impediment to reaching renewable energy goals. The 33% wind and solar annual energy penetration considered in this study results in substantial changes to the characteristics of the bulk power system. This includes different power flow patterns, different commitment and dispatch of existing synchronous generation, and different dynamic behavior from wind and solar generation. The Western Wind and Solar Integration Study (WWSIS), sponsored by the U.S. Department of Energy, is one of the largest regional solar and wind integration studies to date. In multiple phases, it has explored different aspects of the question: Can we integrate large amounts of wind and solar energy into the electric power system of the West? The work reported here focused on the impact of low levels of synchronous generation on the transient stability performance in one part of the region in which wind generation has displaced synchronous thermal generation under highly stressed, weak system conditions. It is essentially an extension of WWSIS-3. Transient stability, the ability of the power system to maintain synchronism among all elements following disturbances, is a major constraint on operations in many grids, including the western U.S. and Texas systems. These constraints primarily concern the performance of the large-scale bulk power system. But grid-wide stability concerns with high penetrations of wind and solar are still not thoroughly understood. This work focuses on 'traditional' fundamental frequency stability issues, such as maintaining synchronism, frequency, and voltage. The objectives of this study are to better understand the implications of low levels of synchronous generation and a weak grid on overall system performance by: 1) Investigating the Western Interconnection under conditions of both high renewable generation (e.g., wind and solar) and low synchronous generation (e.g., significant coal power plant decommitment or retirement); and 2) Analyzing both the large-scale stability of the Western Interconnection and regional stability issues driven by more geographically dispersed renewable generation interacting with a transmission grid that evolved with large, central station plants at key nodes. As noted above, the work reported here is an extension of the research performed in WWSIS-3.

  7. Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets

    SciTech Connect (OSTI)

    2010-10-01

    Broad Funding Opportunity Announcement Project: GE is using nanomaterials technology to develop advanced magnets that contain fewer rare earth materials than their predecessors. Nanomaterials technology involves manipulating matter at the atomic or molecular scale, which can represent a stumbling block for magnets because it is difficult to create a finely grained magnet at that scale. GE is developing bulk magnets with finely tuned structures using iron-based mixtures that contain 80% less rare earth materials than traditional magnets, which will reduce their overall cost. These magnets will enable further commercialization of HEVs, EVs, and wind turbine generators while enhancing U.S. competitiveness in industries that heavily utilize these alternatives to rare earth minerals.

  8. Magnetic infrasound sensor

    DOE Patents [OSTI]

    Mueller, Fred M. (Los Alamos, NM); Bronisz, Lawrence (Los Alamos, NM); Grube, Holger (Los Alamos, NM); Nelson, David C. (Santa Fe, NM); Mace, Jonathan L. (Los Alamos, NM)

    2006-11-14

    A magnetic infrasound sensor is produced by constraining a permanent magnet inside a magnetic potential well above the surface of superconducting material. The magnetic infrasound sensor measures the position or movement of the permanent magnet within the magnetic potential well, and interprets the measurements. Infrasound sources can be located and characterized by combining the measurements from one or more infrasound sensors. The magnetic infrasound sensor can be tuned to match infrasound source types, resulting in better signal-to-noise ratio. The present invention can operate in frequency modulation mode to improve sensitivity and signal-to-noise ratio. In an alternate construction, the superconductor can be levitated over a magnet or magnets. The system can also be driven, so that time resolved perturbations are sensed, resulting in a frequency modulation version with improved sensitivity and signal-to-noise ratio.

  9. AVTA: GE Energy WattStation AC Level 2 Charging System Testing...

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

    Energy WattStation AC Level 2 Charging System Testing Results AVTA: GE Energy WattStation AC Level 2 Charging System Testing Results The Vehicle Technologies Office's Advanced...

  10. Biocompatible Silver-containing a-C:H and a-C coatings: A Comparative Study

    E-Print Network [OSTI]

    Endrino, Jose Luis; Allen, Matthew; Escobar Galindo, Ramon; Zhang, Hanshen; Anders, Andre; Albella, Jose Maria

    2007-01-01

    containing a-C:H and a-C coatings: A comparative Study Josefree amorphous carbon (a-C) coatings are known to beinto diamond-like carbon (DLC) coatings by plasma based ion

  11. Docket No. EERE-2011-BT-NOA-0067 and RIN Number 1904-AC52 Ex...

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

    1-BT-NOA-0067 and RIN Number 1904-AC52 Ex parte Communication Docket No. EERE-2011-BT-NOA-0067 and RIN Number 1904-AC52 Ex parte Communication This memorandum for the record...

  12. Controlling Magnetism at the Nanoscale

    E-Print Network [OSTI]

    Wong, Jared

    2012-01-01

    157 A.2 Magnetism Unit Conversion148 A.1 Magnetism Unit ConversionA·m) Table A.1: Magnetism Unit Conversion Table Quantity A.1

  13. On the ac magnetic susceptibility of spin-chains: solitons in one-dimensional systems

    E-Print Network [OSTI]

    Fominov, Yakov

    University, Krakow, Poland E. Pikina Institute for Problems of Oil and Gas RAS, Moscow, Russia W. Haase Shubnikov' Institute of Crystallography RAS, Moscow, Russia Z. Tomkowicz Institute of Physics, Jagiellonian

  14. "Permanent Magnet Generator-like AC Current Drive for Torroidal Fusion

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservationBio-Inspired SolarAboutXuRod Hunt (208) 386-52542Devices" Inventor..--.. Ali

  15. AC&N Incident Reporting The Colorado School of Mines takes all complaints about inappropriate traffic

    E-Print Network [OSTI]

    not help with email that originated outside the CSM network. Please see the AC&N Spam Management web page

  16. 9 17 25 3 http://www.adm.u-tokyo.ac.jp/gakunai/office/anzenei

    E-Print Network [OSTI]

    Goda, Keisuke

    ://www.adm.u-tokyo.ac.jp/gakunai/office/anzenei sei/org/taisei.html [ HP] 2. UTCRIS 18 3 UTCRIS #12;https-1 HP http://www.esc.u-tokyo.ac.jp/haisui/index.html [HP] 5. 3-3 2 3 3 2 2 1,1- HP http://www.adm.u-tokyo.ac.jp/office/anzeneisei/admin/tokutei_kagaku.html [ HP] 6. 6 HP http://www.esc.u-tokyo.ac.jp/seihai/seihai.html

  17. Boys and Girls, Be Ambitious! http://www.math.sci.hokudai.ac.jp/message/message-graduates/

    E-Print Network [OSTI]

    Nakamura, Iku

    ://www.math.sci.hokudai.ac.jp/ #12;AIKAWA, Hiroaki WebPage http://www.math.sci.hokudai.ac.jp/ aik/index-j.html Fatou Martin Harnack AKITA, Toshiyuki WebPage http://www.math.sci.hokudai.ac.jp/ akita/ Eilenberg-MacLane Coxeter #12;ASAKURA, Masanori ARAI, Asao ABE, Noriyuki WebPage http://www.math.sci.hokudai.ac.jp/ abenori/ #12;ISHIKAWA, Goo Web

  18. Aalborg Universitet Active Power Regulation based on Droop for AC Microgrid

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Active Power Regulation based on Droop for AC Microgrid Li, Chendan; Coelho., Quintero, J. C. V., & Guerrero, J. M. (2015). Active Power Regulation based on Droop for AC Microgrid.aau.dk on: november 29, 2015 #12;Active Power Regulation based on Droop for AC Microgrid Chendan Li, Student

  19. Aalborg Universitet Stability Analysis for Isolated AC Microgrids Based on PV-Active Generators

    E-Print Network [OSTI]

    Vasquez, Juan Carlos

    Aalborg Universitet Stability Analysis for Isolated AC Microgrids Based on PV-Active Generators for Isolated AC Microgrids Based on PV-Active Generators. In Proceedings of the 2015 IEEE Energy Conversion.aau.dk on: november 29, 2015 #12;Stability Analysis for Isolated AC Microgrids Based on PV-Active Generators

  20. Fault-tolerant Partial-resonant High-frequency AC-link Converters and Their Applications 

    E-Print Network [OSTI]

    Keyhani, Hamidreza

    2014-01-08

    in the converter shutdown, and thus system availability is improved. The high-frequency ac link of the introduced converters is composed of an ac inductor and small ac capacitor. The link inductor is responsible for transferring power, while the link capacitor...