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11th International Conference on Electrical Machines and Systems(第11届国际电机与系统会议)

作者： Chun Zhao Jiangjun Ruan Zhiye Du Shoubao Liu Yefeng Yu Yuanhang Zhang Institute of Advanced Technology for Electrical Engineering Wuhan University Wuhan China 430072

This paper uses multi-conductor transmission line (MTL) to model transformer windings. According to the symmetry of windings, a 2D equivalent finite element model can be set up under ANSYS environment. On the basis, Finite Element Method (FEM) is used to calculate the distributed parameters in transformer windings. In the process of calculation, the skin effect is focused on. The frequency-dependent parameters are calculated at the different frequency points based on FEM. Therefore, the calculating parameters are helpful to research on propagation characteristics of PD pulses in electric equipments.

关键词： multi-conductor transmission line transformer winding finite element method distributed parameter skin effect

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A new Method to Detect the Short Circuit Current in DC Supply System based on the Flexible Rogowski Coil

A new Method to Detect the Short Circuit Current in DC Suppl...

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2011 1st International Conference on Electric Power Equipment- Switching Technology(第一届电力设备开断技术国际会议 ICEPE)

作者： Yan Wang Xiaoshe Zhai Zhengxiang Song Yingsan Geng State Key Laboratory of Electrical Insulation and Power Equipment Xi'an Jiaotong University Xi'an 710049 China

ISBN: (纸本)9781457712739

The short circuit current in DC (Direct Current) supply system will rise to a risk value within a few milliseconds. The current limiter must detect this fault on microsecond level to restrict the amplitude of short circuit current more effectively. For the existing method, the shunt is always employed for such fault detection, where the time to detect the fault current is relative long and hard for the rapid detection. In this paper, a novel method based on the flexible Rogowski coil is proposed, where the differential signal and the integral signal of the Rogowski coil are combined to perform the relay protection function. The design method of the coil, the relative experiments and the simulation result of the relay protection system are all discussed in sequence. Firstly, the equivalent circuit of the Rogowski coil is established, in which the distributed parameters of the coil are calculated with the Finite Element Method. Secondly, the frequency response of the coil is calculated and validated experimentally. The parameters of the Rogowski coil can be adjusted and designed according to the simulation result. Finally, the simulation of the relay protection system is performed, which shows that the demand of short current protection in ship DC distribution system can be satisfied and the method proposed in this paper is verified.

关键词： short-circuit currents ROGOWSKI COIL Simulation results Relay protection DC power supply fault currents Current limiters design approach differential signalling Defect detection distributed parameter

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Maximum Likelihood Estimation of Clock Skew in Sparse One-Way Packet Transmissions for Machine Type Communication Applications

Maximum Likelihood Estimation of Clock Skew in Sparse One-Wa...

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Ad-Hoc and Sensor Networks Symposium

作者： Atanu Guchhait Samsung R&D Institute India - Bangalore

ISBN: (纸本)9781479966653

Establishing and maintaining time synchronization among the nodes in a distributed wireless network with desired accuracy is challenging. In upcoming machine type communication (MTC) applications a fast, scalable and accurate synchronization method is highly desired. We view the clock synchronization problem as peer-to-peer (P2P) continuously running process where clock master with a stable clock source transmits packets with transmit time stamp. Synchronizing nodes listen these packets and apply receive time stamps. Based on the passive listening framework developed in [1], we propose Passive Sparse Maximum Likelihood Estimator (PSMLE) that uses two observations spaced sufficiently apart in time to estimate clock skew. The PSLME based skew estimate is further used by Passive Maximum Likelihood Estimator (PMLE) to estimate clock offset. The resulting enhanced-PMLE (ePMLE) improves estimation accuracy with fewer packet observations. Random component of the link delay is assumed to be Gaussian distributed. We observe that estimator accuracy is independent of propagation delay and distribution parameter and set them to zero without impacting the estimation accuracy. Further, we show that Cramer-Rao Lower Bound (CRLB) does not exist for PSMLE. However we verify through analysis and simulations that by choosing nearly compact observation window for PSMLE and optimal number of packet observations for ePMLE, sub-millisecond (sub-ms) clock accuracy can be achieved for all practical MTC scenarios.

关键词： maximum likelihood estimation Packet clock recovery clock skew Timing devices distributed wireless network observation window timestamp distributed parameter COMMUNICATIONS APPLICATION Propagation delay Ganglia

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HUM Method for the One Dimension Wave Equation

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IFAC Proceedings Volumes 1995年第19期28卷 385-389页

作者： R.L.V. Gonzalez G.F. Reyero CONICET - Universidad Nacional de Rosario Dep. Matemática Fac. Ciencias Exactas Ingeniería y Agrimensura 2000 Rosario Argentina

We deal with the problem of implementation of exact controllers of distributed parameter systems without damping. Specifically, we study a model of a vibrating simple string. We propose a practical closed loop implementation of HUM controls and we also analyze the structural instability of the proposed implementation under parameter perturbations on system’s data.

关键词： Exact controllability HUM method overspilling wave equation distributed parameter

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On the connections between used models of power transmission lines

On the connections between used models of power transmission...

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IEEE Power and Energy Society General Meeting

作者： M. Belhocine B. Marinescu RTE R&D Division 9 rue de la porte de Buc 78000 Versailles

ISBN: (纸本)9781479913022

The dynamic structures of three usual models for power transmission lines are compared. It is shown that, from a systemic point of view, the so-called π-model is the reduction of the distributed parameters one. This complements the well known comparison of the trajectories provided by these models. This new view is useful for the analysis and simulation of power systems dynamic behavior. Indeed, this structural analysis allows one to better link the models used in simulation to the specific phenomena which have to be reproduced like, e.g., interarea oscillations, hyposynchronous oscillations. This leads to the unification and classification of some models actually used in different simulators which can thus be simplified and improved. The results have been obtained in a theoretical framework and, afterwards, checked by numeric simulations.

关键词： Power transmission lines infinite dimensional systems model reduction Power transmission lines Multidimensional systems Reduced order model Connections Power system simulation distributed parameter simulating

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General Principles for Designing distributed Control Systems

General Principles for Designing Distributed Control Systems

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Wave Electronics and its Application in Information and Telecommunication Systems (WECONF)

作者： I. M. Pershin A. L. Liashenko E. G. Papush North-Caucasus Federal University St. Petersburg Electrotechnical University «LETI» Pyatigorsk Russia St. Petersburg State University of Aerospace Instrumentation St. Petersburg Russia North-Caucasus Federal University Pyatigorsk Russia

ISBN: (数字)9781728149448

ISBN: (纸本)9781728149455

The well-known frequency concept of analysis and synthesis of concentrated systems is transferred to the selected class of systems with distributed parameters. The main provisions of the frequency analysis and synthesis method for distributed systems are formulated, and specially developed distributed links are presented, from which the structure of a distributed controller is formed during the synthesis process. Since the mathematical models of many distributed objects do not have an analytical solution, the transfer functions of nonstandard approximating links used to describe the characteristics of distributed objects are given. An example of designing a distributed control system for the hydrolithosphere process is also considered.

关键词： distributed object spatially invariant systems with distributed parameters spatial hodograph distributed controller distributed control systems Frequency analysis control systems Distribute synthesis distributed Systems distributed parameter Mathematical Model

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Underdetermined source separation using time-frequency masks and an adaptive combined Gaussian-Student's t probabilistic model

Underdetermined source separation using time-frequency masks...

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Yang Sun Waqas Rafique Jonathon A. Chambers Syed Mohsen Naqvi Communications Sensors Signal and Information Processing Group School of Electrical and Electronics Engineering Newcastle University NE1 7RU UK

ISBN: (纸本)9781509041183

Time-frequency (T-F) masking algorithms are focused at separating multiple sound sources from binaural reverberant speech mixtures. The statistical modelling of binaural cues i.e. interaural phase difference (IPD) and interaural level difference (ILD) is a significant aspect of such algorithms. In this paper, a Gaussian-Student's t distribution combined mixture model is exploited for robust binaural speech separation. The weights of the distribution components are calculated adaptively with the energy of the speech mixtures. The expectation maximization (EM) algorithm is applied to calculate the parameters of the distributions. The speech signals from the TIMIT database are convolved with the real binaural room impulse responses (BRIRs) from two datasets for the evaluation of the proposed method. The objective performance measure signal to distortion ratio (SDR) confirms the improvement and robustness of the proposed method.

关键词： Source separation Gaussian-Student's t combined mixture model adaptive weights real binaural room impulse responses Source separation Phase Mask Speech distributed parameter Probabilistic Model Masks

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Ray-Tracing Urban Picocell 3D Propagation Statistics for LTE Heterogeneous Networks

Ray-Tracing Urban Picocell 3D Propagation Statistics for LTE...

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European Conference on Antennas and Propagation

作者： Evangelos Mellios Geoffrey S. Hilton Andrew R. Nix Centre for Communications Research University of Bristol United Kingdom

ISBN: (纸本)9781467321877

This paper combines measured 3-Dimensional (3D) basestation (BS) and user handheld antenna radiation patterns with a state-of-the-art 3D ray-tracing software tool in order to derive a set of urban 3D picocell propagation statistics suitable for Long Term Evolution (LTE) Heterogeneous Network (HetNet) planning. Results are presented as Cumulative Distribution Functions (CDFs) and as a function of distance from the BS. Best-fit normal and lognormal distribution parameters are also presented.

关键词： picocell Long Term Evolution Heterogeneous networks distributed parameter Ray tracing

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STATISTICAL DETECTION OF INFORMATION HIDING BASED ON ADJACENT PIXELS DIFFERENCE

STATISTICAL DETECTION OF INFORMATION HIDING BASED ON ADJACEN...

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European Signal Processing Conference

作者： Remi Cogranne Cathel Zitzmann Florent Retraint Igor Nikiforov Philippe Cornu Lionel Fillatre ICD - LM2S - Universite de Technologie de Troyes - UMR STMR CNRS

ISBN: (纸本)9781467310680

This paper presents a novel methodology for statistical detection of Least Significant Bits (LSB) matching steganography. It proposes to exploit a statistical model of natural images adjacent pixels difference. In this paper, the detection problem is first addressed in a theoretical context when cover image parameters are known. The most powerful likelihood ratio test (LRT) is designed and its statistical performances are analytically expressed. Then, for a practical case of unknown image analysis, an estimation of distribution parameters is proposed to designed a test whose performance are also analytically established. Numerical results on a large image database shows the relevance of proposed methodology.

关键词： Hypothesis testing Data hiding Information forensics Detection theory Image processing visual databases pixel distributed parameter statistical models (nuclear image analysis

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3D Social Saliency from Head-mounted Cameras 12

3D Social Saliency from Head-mounted Cameras

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Annual Conference on Neural Information Processing Systems

作者： Hyun Soo Park Eakta Jain Yaser Sheikh Carnegie Mellon University Texas Instruments

ISBN: (纸本)9781627480031

A gaze concurrence is a point in 3D where the gaze directions of two or more people intersect. It is a strong indicator of social saliency because the attention of the participating group is focused on that point. In scenes occupied by large groups of people, multiple concurrences may occur and transition over time. In this paper, we present a method to construct a 3D social saliency field and locate multiple gaze concurrences that occur in a social scene from videos taken by head-mounted cameras. We model the gaze as a cone-shaped distribution emanating from the center of the eyes, capturing the variation of eye-in-head motion. We calibrate the parameters of this distribution by exploiting the fixed relationship between the primary gaze ray and the head-mounted camera pose. The resulting gaze model enables us to build a social saliency field in 3D. We estimate the number and 3D locations of the gaze concurrences via provably convergent mode-seeking in the social saliency field. Our algorithm is applied to reconstruct multiple gaze concurrences in several real world scenes and evaluated quantitatively against motion-captured ground truth.

关键词： Ocular Fixation Cameras Three Dimensions Eye distributed parameter Videotapes

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