Engineering Commons^™

Ann-Based Technique For Predicting Voltage Collapse In Power Systems, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Voltage stability problems have been one of the major concerns for electric utilities as a result of heavy loading of power system. This paper reports on an investigation on the application of Artificial Neural Networks (ANN) in voltage stability assessment using the energy function technique. A multi-layer feed-forward ANN with error back-propagation learning algorithm is proposed for calculation of Voltage Stability Margins (VSM). Extensive testing of the proposed ANN based approach indicates its validity for determination of power system voltage collapse. Simulation results on two test systems are reported in the paper.

Structural Usable Speech Measure Using Lpc Residual, Ananth N. Iyer, Melinda Gleiter, Brett Y. Smolenski, Robert E. Yantorno

Ananth N Iyer

In an operational environment speech is degraded by many kinds of interferences. The operation of many speech processing techniques are plagued by such interferences. Usable speech extraction is a novel concept of processing degraded speech data. The idea of usable speech is to identify and extract portions of degraded speech that are considered useful for various speech processing systems. The performance reduction of speaker identification systems under degraded conditions and use of usable speech concept to improve the performance has been demonstrated in previous work. A new usable speech measure, based on the structure of Linear Predictive Coding (LPC) residual …

Usable Speech Detection Using Linear Predictive Analysis, Nitya Sundaram, Robert E. Yantorno, Brett Y. Smolenski, Ananth N. Iyer

Ananth N Iyer

A speech segment is defined as “usable,” if speech, which is corrupted by interfering speech, can still be used for applications like speaker identification. In tactical communications, where there are multiple signals transmitted over the same channel such as telephone or radio transmission, separation of usable speech from speech corrupted by voices of other speakers is desired. This separation is important in making automatic speaker and speech recognition systems more robust. A novel approach towards developing a usable speech measure could be model-based. Using this concept of model-based usable speech detection, the use of Linear Prediction is investigated. The method …

Convergence Of The Singular Value Based Model Order Reduction Algorithm, Tammy Stitz

Tammy Stitz

Fast Voltage Contingency Screening Using Radial Basis Function Neural Network, T Jain, L Srivastava, Sn Singh

SN Singh PhD

No abstract provided.

Combined Beamforming And Space-Time Block Coding With A Sparse Array Antenna, Robert H. Morelos-Zaragoza, Mohammad Ghavami

Robert Henry Morelos-Zaragoza

In this paper, we continue our investigation of joint beamforming and transmit diversity with space-time block coding. In particular, the performance of a four-element array antenna is considered, in the context of an indoor wireless communication system. The main contribution is to show that transmit diversity may be practically achieved, even with correlated beams produced by a sparse array antenna.

Neuro-Fuzzy Approach For Development Of New Neuron Model, Manmohan, D. K. Chaturvedi, P. S. Satsangi, P. K. Kalra

D. K. Chaturvedi Dr.

The training time of ANN depends on size of ANN (i.e. number of hidden layers and number of neurons in each layer), size of training data, their normalization range and type of mapping of training patterns (like X–Y, X–DY, DX–Y and DX–DY), error functions and learning algorithms. The efforts have been done in past to reduce training time of ANN by selection of an optimal network and modification in learning algorithms. In this paper, an attempt has been made to develop a new neuron model using neuro-fuzzy approach to overcome the problems of ANN incorporating the features of fuzzy systems …

Combined Beamforming And Space-Time Block Coding With Sparse Array Antennas, Robert H. Morelos-Zaragoza

Robert Henry Morelos-Zaragoza

In this paper, the combination of beamforming and space-time block coding is investigated. An adaptive scheme for the assignment of transmission beams is proposed. Data for the determination of beams are obtained using a triangular switch-beam array antenna at the transmitter. The number of peak points is determined from the data and a prescribed threshold level. Orthogonal space-time block coding is then applied to the transmission beams. We examine the distribution of the number of assigned beams as a function of indoor wireless channel parameters. Also, the effects of a small number of array elements and associated correlated beams, and …

Network Security Risk Assessment Modeling Tools For Critical Infrastructure Assessment, George H. Baker, Samuel Redwine, Joseph Blandino

George H Baker

The James Madison University (JMU) CIPP research team is developing Network Security Risk Assessment Modeling (NSRAM) tools that will enable the assessment of both cyber and physical infrastructure security risks. The effort is driven by the need to predict and compute the probability of adverse effects stemming from system attacks and malfunctions, to understand their consequences, and to improve existing systems to minimize these consequences.

The tools are targeted at systems supporting critical infrastructures varying from individual systems to organization-wide systems, to systems covering entire geographical regions. Early work emphasizes computing systems, but systems sharing the network nature of computing …

On The Design Of An Evolutionary Preprocessor, Sanza Kazadi, Daniel Choi, Albert Chang, Ted Kang, Hubert Li, Daniel Kim, Stanley Ho, Johns Wu

Sanza Kazadi

Direct Torque Control Strategy Of Permanent Magnet Synchronous Machines, Djamila Rekioua Pr

REKIOUA Djamila Dr

Direct torque control (DTC) can be applied to all AC machine drives. The synchronous machine torque control, based on the DTC structure, permits to obtained high dynamic performances. This method is a concrete solution to robustness and dynamics problems find in other control structures. In this paper, we present a direct torque control strategy with minimization torque pulsations. We use a current sensor and an incremental position sensor . In order to control the torque, we use an hysteresis current controllers technique. This strategy consists on detecting the current at the voltage inverter input, and adjusted it to follow a …

Comparison Among Booth's And Pekmestzi's Algorithm For The Multiplication Of Two Numbers, I. E. Villalon-Turrubiates, R. Rojas-Laguna, S. Serrano-Arellano, E. Alvarado-Méndez, J. M. Estudillo-Ayala, O. Vite-Chávez

Iván Esteban Villalón Turrubiates

A comparison between two different methods of multiplication of two 8-bit numbers is presented. This methods are the Booth’s algorithm and the algorithm proposed by Kiamal Z. Pekmestzi. The general objective is to show the benefits and the advantages obtained if it’s used one of this algorithms over the other. This multipliers have low circuit complexity permitting high-speed operations and the interconnections of the cells are regular. This is the reason why the results shown was obtained using VHDL realization on a FPGA XC4010XL by Xilinx.

Adaptive Nonlinear Control Of Induction Motor Using Neural Networks’, Nadir Kabache, Boukhemis Chetate

Boukhemis Chetate

No abstract provided.

Control Of Transient Over-Voltage At Customers Buses Due To The Switching Capacitors, Hocine Labar, Kamel Bounaya, Boukhemis Chetate , Tarak Mesbah

Boukhemis Chetate

This paper describes concerns for capacitor switching transients at customer buses witch cause power quality problem. The magnification of transients is caused by various factors : plant load, switched capacitor size, customer load characteristics, power factor correction and the utility distribution, etc. The results of simulation illustrate the impact of these factors , the important effect of energy levers associated with transients and the complex interaction between the capacitor banks and the source and load resulting in several transient over voltage phenomena . Recommendations for best solution to the magnification problems are also presented .

Photonic Crystal Resonators”,, Andrew Sarangan

Andrew Sarangan

University of Cincinnati ECE Dept Seminars

Method Of Non-Data-Aided Carrier Recovery With Modulation Identification, Kenta Umebayashi, Robert H. Morelos-Zaragoza, Ryuji Kohno

Robert Henry Morelos-Zaragoza

A non-data aided carrier recovery technique using digital modulation format identification called multi-mode PLL (Phase Locked Loop) is proposed. This technique can be interpreted as a modulation identification method that is robust against static phase and frequency offsets. The performance of the proposed technique is studied and the analytical expressions are derived for the probability of lock detection, acquisition time over AWGN channel in the cases of M-PSK and M-Qam modulations with respect to frequency offset and signal-to-noise ratio.

Low-Density Parity-Check Codes For Volume Holographic Memory Systems, Hossein Pishro-Nik, Nazanin Rahnavard, Jeongseok Ha, Faramarz Fekri, Ali Adibi

Hossein Pishro-Nik

We investigate the application of low-density parity-check (LDPC) codes in volume holographic memory (VHM) systems. We show that a carefully designed irregular LDPC code has a very good performance in VHM systems. We optimize high-rate LDPC codes for the nonuniform error pattern in holographic memories to reduce the bit error rate extensively. The prior knowledge of noise distribution is used for designing as well as decoding the LDPC codes. We show that these codes have a superior performance to that of Reed-Solomon (RS) codes and regular LDPC counterparts. Our simulation shows that we can increase the maximum storage capacity of …

Photoimageable Material Patterning Techinques Useful In Fabricating Conductive Lines In Circuit Structures, P Moon, M Hussein, A Myers, C Recchia, S Sivakumar, A Kandas

Charles H Recchia

No abstract provided.

Detection, Localization, And Classification Of Power Quality Disturbances Using Discrete Wavelet Transform Technique, Tarek Ibrahim Elshennawy Dr., Amr Yehia Abou-Ghazala A. Prof., Mahmoud El-Gammal Prof.

Tarek Ibrahim ElShennawy

Modern spectral and harmonic analysis is based on Fourier based transforms. However, these techniques are less efficient in tracking the signal dynamics for transient disturbances. Consequently, The wavelet transform has been introduced as an adaptable technique for non-stationary signal analysis. Although the application of wavelets in the area of power engineering is still relatively new, it is evolving very rapidly. The application of the wavelet transform in detection, time localization, and classification of power quality disturbances is investigated and a new identification procedure is presented. Different power quality disturbances will be classified by a unique energy distribution pattern based on …

Co-Ordinated Application Of Facts Devices To Enhance Steady-State Voltage Stability, Arturo Roman Messina

A. R. Messina

This paper examines the co-ordinated application of flexible ac transmission system (FACTS) technologies to extend system voltage stability margins. A systematic analysis and design method, based on the singular value/eigenvalue decomposition analysis of the load-flow Jacobian and the study of the controllability characteristics of an equivalent state model is used to study the voltage instability phenomenon as well as to assess the potential for small-signal voltage stability improvement by means of FACTS compensation. The method is of particular interest for the preliminary design of new system devices and the study of interactions among existing controllers. Results obtained using a practical …

Analysis Of Subsynchronous Torsional Interactions With Svcs, Arturo Roman Messina

A. R. Messina

This paper presents the results of an analytical investigation aimed at assessing the potential for subsynchronous torsional interactions (SSTIs) between turbine-generator rotors and static VAR compensators (SVCs) in longitudinal power systems.A n advanced linear state model of the power system is developed that allows detailed evaluation of the impact of FACTS controllers on SSTIs with turbine generators, as well as the identification of potentially undesirable effects associated with the application of multiple controllers.This approach is general enough to include the representation of complex systems and can be used in conjunction with efficient techniques for the analysis of large sparse linear …

Damping Of Low-Frequency Interarea Oscillations Using Hvdc Modulation And Svc Voltage Support, Arturo Roman Messina

A. R. Messina

This paper discusses the results of preliminary studies conducted to examine the applicability of high-voltage direct current (HVDC) technology and static Volt-Amp Reactive (VAR) compensation to aid damping of low-frequency interarea oscillations in the Mexican interconnected system (MIS). The study of interarea oscillations and the design of controls is done using modal analysis of a linearized AC/DC state space model of the power system at a particular operating point. The utilized methodology is tested on a planning model of the MIS that includes a proposed HVDC transmission system embedded in an AC network in which several SVCs are used for …

Normal Form Analysis Of Stressed Power Systems: Incorporation Of Svc Models, E Barocio, Arturo Roman Messina

A. R. Messina

In this paper a comprehensive analytical technique based on normal form theory and symbolic computer algebra is proposed for the analysis of non-linear inter-area oscillations in stressed power systems that incorporate the operation of Static VAR Compensators (SVCs). A second-order representation of the power system is derived that considers the explicit representation of synchronous machines and multiple SVCs in the state representation. On the basis of this model, normal form theory is used to study non-linear power system behaviour following large disturbances. The proposed approach is general and may be extended to include other FACTS devices. A simplified 4- machine, …

Assessment Of Nonlinear Modal Interaction In Stressed Power Networks Using The Method Of Normal Forms, Arturo Roman Messina

A. R. Messina

No abstract provided.

Funções De Base Em Modelos Rbf: Um Estudo De Caso Na Modelagem Do Sistema De Lorenz, Gladstone B. Alves, Luis A. Aguirre

Gladstone B. Alves

No abstract provided.

Otimização Baseada Na Quimiotaxia Social De Bactérias: Introdução E Perspectivas, Gladstone B. Alves

Gladstone B. Alves

No abstract provided.

Periodic Broadcast And Patching Services - Implementation, Measurement And Analysis In An Internet Streaming Video Testbed, Mk Bradshaw, B Wang, S Sen, Lx Gao, J Kurose, P Shenoy, D Towsley

Lixin Gao

No abstract provided.

Autonomous Vehicles Research Laboratory – Phase Ii: Mobile Robots And A Walking Internet, Raúl Ordóñez

Raúl Ordóñez

PI, Funded by the University of Dayton Research Council, $8,000.

Measuring Electrocatalytic Activity On A Local Scale With Scanning Differential Electrochemical Mass Spectrometry, K. Jambunathan, Andrew C. Hillier

Andrew C. Hillier

This paper describes a new technique entitled scanning differential electrochemical mass spectrometry ~SDEMS! that combines a quadrupole mass spectrometer with a membrane-covered capillary inlet and a high resolution positioning system that is designed to perform spatial mapping in solution near an electrode interface. Potential applications of this technique include the local characterization of anode catalysts for fuel cells as well as a range of analytical measurements and combinatorial screening studies. The capabilities of this technique are demonstrated by monitoring product evolution in several model electrocatalytic reactions, including the hydrogen evolution reaction, carbon monoxide oxidation, and the direct oxidation of methanol …

Screening The Reactivity Of Ptxruy And Ptxruymoz Catalysts Toward The Hydrogen Oxidation Reaction With The Scanning Electrochemical Microscope, S. Jayaraman, Andrew C. Hillier

Andrew C. Hillier

We report an application of the scanning electrochemical microscope that exploits its ability to spatially map the kinetics of heterogeneous electron-transfer reactions in order to perform screening measurements for combinatorial studies of electrooxidation catalysts. The ability to measure the activity of catalyst surfaces toward the hydrogen oxidation reaction via tip−sample feedback is used to characterize the activity of PtxRuy and PtxRuyMoz catalysts as a function of composition and electrode potential. Multielement band electrodes containing various compositions of PtxRuy and PtxRuyMoz deposits are created via pulsed electrochemical deposition onto patterned substrates. Catalyst compositions are verified through a combination of Auger electron …