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2003

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The Development Of A Closed-Form Expression For The Input Impedance Of Power-Return Plane Structures, Minjia Xu, Todd H. Hubing Jan 2003

The Development Of A Closed-Form Expression For The Input Impedance Of Power-Return Plane Structures, Minjia Xu, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

In multilayer printed circuit boards, the noise on the power bus is influenced by the impedance between the power and ground planes. Power-bus noise estimates require an accurate estimate of the power-bus input impedance. This paper develops a closed-form estimate of the input impedance for circular power-return plane structures. When the structure is lossy (e.g., boards employing embedded capacitance or densely populated boards), the energy reflected from the board edge does not significantly affect the input impedance. In general, the expressions developed here for circular structures can be used to estimate the impedance of lossy power-return plane structures of any …

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The Subcircuit Extraction Problem, Nian Zhang, Donald C. Wunsch, Frank Harary Jan 2003

The Subcircuit Extraction Problem, Nian Zhang, Donald C. Wunsch, Frank Harary

Electrical and Computer Engineering Faculty Research & Creative Works

The steady down scaling of CMOS device dimensions has been the main stimulus to the growth of microelectronics and computer aided very large scale integration (VLSI) design. But the more an integrated circuit (IC) is scaled, the higher its packing density becomes. The increasing size of chips, measured in either area or number of transistors, and the waste of the large capital investment involved in fabricating and testing circuits that do not work, make layout analysis and verification an important part of physical design automation. The most efficient way to overcome these difficulties is to identify a related collection of …

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A Continually Online Trained Neurocontroller For The Series Branch Control Of The Upfc, Ganesh K. Venayagamoorthy, Radha P. Kalyani Jan 2003

A Continually Online Trained Neurocontroller For The Series Branch Control Of The Upfc, Ganesh K. Venayagamoorthy, Radha P. Kalyani

Electrical and Computer Engineering Faculty Research & Creative Works

The crucial factor affecting the modern power systems today is load flow control. The Unified Power Flow Controller (UPFC) provides an effective means for controlling the power flow and improving the transient stability in a power network. The UPFC has fast complex dynamics and its conventional control is based on a linearized model of the power system. This paper presents the design of a neurocontroller that controls the power flow and regulates voltage along a transmission line. The continually online neurocontroller is used for controlling the series inverter of UPFC. Simulation results carried out in the PSCAD/EMTDC environment are presented …

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A Discrete-Time Model For Spatio-Temporally Correlated Mimo Wssus Multipath Channels, Chengshan Xiao, Jingxian Wu, Sang-Yick Leong, Y. Rosa Zheng, Khaled Ben Letaief Jan 2003

A Discrete-Time Model For Spatio-Temporally Correlated Mimo Wssus Multipath Channels, Chengshan Xiao, Jingxian Wu, Sang-Yick Leong, Y. Rosa Zheng, Khaled Ben Letaief

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a statistical discrete-time model is proposed for simulating wideband MIMO channels which experience spatially and temporally correlated, widesense stationary uncorrelated scattering (WSSUS) multipath Rayleigh fading. A new method is also presented to efficiently generate the correlated MIMO channel coefficients, which can be used for accurate simulation of physical continuous-time MIMO channel. The statistic accuracy of the discrete-time MIMO channel model is rigorously verified through theoretical analysis and extensive simulations in different criteria.

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A Dynamic Model Of Induction Generators For Wind Power Studies, Badrul H. Chowdhury, Srinivasa R. Chellapilla Jan 2003

A Dynamic Model Of Induction Generators For Wind Power Studies, Badrul H. Chowdhury, Srinivasa R. Chellapilla

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents an induction generator model that can be used for simulations to investigate and evaluate the control strategies for variable speed operation of doubly fed induction generators driven by wind turbines in transient conditions. The model makes use of rotor reference frame.

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A Nested Sensor Array Focusing On Near Field Targets, Y. Rosa Zheng, M. El-Tanany, R. A. Goubran Jan 2003

A Nested Sensor Array Focusing On Near Field Targets, Y. Rosa Zheng, M. El-Tanany, R. A. Goubran

Electrical and Computer Engineering Faculty Research & Creative Works

A nested virtual array subband beamforming system is proposed for applications where broadband signal targets are located within the near field of the array. Subband multirate processing and near field beamforming techniques are used jointly for the nested array to improve the performances and reduce the computational complexity. A new noise model, namely the broadband near field spherically isotropic noise model, is also proposed for the optimization design of near field beamformers. It is shown that near field beamforming is essential for better distance discrimination of near field targets, reduced beampattern variations for broadband signals, and stronger reverberation suppression.

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A Statistical Simulation Model For Mobile Radio Fading Channels, Chengshan Xiao, Y. Rosa Zheng Jan 2003

A Statistical Simulation Model For Mobile Radio Fading Channels, Chengshan Xiao, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, a Clarke's model-based simulator was proposed for Rayleigh fading channels. However, that model, as shown in this paper, may encounter statistic deficiency. Therefore, an improved model is presented to remove the statistic deficiency. Furthermore, a new simulation model is proposed for Rician fading channels. This Rician fading simulator with finite number of sinusoids plus a zero-mean stochastic sinusoid as the specular (line-of-sight) component is different from all the existing Rician fading simulators, which have non-zero mean deterministic specular component. The statistical properties of the proposed Rayleigh and Rician fading channel models are analyzed in detail, which shows that these …

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A Study Of The Probe Induced Disturbances On The Near-Field Measurement, Jin Shi, Richard E. Dubroff, Kevin P. Slattery, Masahiro Yamaguchi, K.-I. Arai Jan 2003

A Study Of The Probe Induced Disturbances On The Near-Field Measurement, Jin Shi, Richard E. Dubroff, Kevin P. Slattery, Masahiro Yamaguchi, K.-I. Arai

Electrical and Computer Engineering Faculty Research & Creative Works

Numerical simulations were used to investigate the disturbance introduced by placing a small magnetic loop probe in the near field of a driven loop. In the absence of the loop probe, the numerical simulations were compared with an approximate closed-form analytical expression for the magnetic field produced by the driven loop. The agreement between the approximate analytical results and the simulation was good. The next set of simulations was based on a physical model that included the probe and showed that the probe does exert an effect on the field being measured. Examples of these simulations and their implications on …

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Adaptive Critic Design Based Neurocontroller For A Statcom Connected To A Power System, Salman Mohagheghi, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2003

Adaptive Critic Design Based Neurocontroller For A Statcom Connected To A Power System, Salman Mohagheghi, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

A novel nonlinear optimal neurocontroller for a static compensator (STATCOM) connected to a power system using artificial neural networks is presented in this paper. The heuristic dynamic programming (HDP), a member of the adaptive critic designs (ACDs) family, is used for the design of the STATCOM neurocontroller. This neurocontroller provides nonlinear optimal control with better performance compared to the conventional PI controllers.

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Adaptive Critic Designs And Their Implementations On Different Neural Network Architectures, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2003

Adaptive Critic Designs And Their Implementations On Different Neural Network Architectures, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

The design of nonlinear optimal neurocontrollers based on the Adaptive Critic Designs (ACDs) family of algorithms has recently attracted interest. This paper presents a summary of these algorithms, and compares their performance when implemented on two different types of artificial neural networks, namely the multilayer perceptron neural network (MLPNN) and the radial basis function neural network (RBFNN). As an example for the application of the ACDs, the control of synchronous generator on an electric power grid is considered and results are presented to compare the different ACD family members and their implementations on different neural network architectures.

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Analysis Of Simple Two-Capacitor Low-Pass Filters, Todd H. Hubing, David Pommerenke, Theodore M. Zeeff, Thomas Van Doren Jan 2003

Analysis Of Simple Two-Capacitor Low-Pass Filters, Todd H. Hubing, David Pommerenke, Theodore M. Zeeff, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The performance of typical low-pass capacitor filters is limited by the mutual inductance between the input and output sides of the filter. This paper describes how two appropriately spaced capacitors can be used to construct a low-pass filter with significantly better high-frequency performance than a one-capacitor filter. Laboratory measurements and numerical simulations are used to quantify the mutual inductance and compare the performance of one- and two-capacitor low-pass filters.

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A Comparison Of Dual Heuristic Programming (Dhp) And Neural Network Based Stochastic Optimization Approach On Collective Robotic Search Problem, Nian Zhang, Donald C. Wunsch Jan 2003

A Comparison Of Dual Heuristic Programming (Dhp) And Neural Network Based Stochastic Optimization Approach On Collective Robotic Search Problem, Nian Zhang, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

An important application of mobile robots is searching a region to locate the origin of a specific phenomenon. A variety of optimization algorithms can be employed to locate the target source, which has the maximum intensity of the distribution of some detected function. We propose two neural network algorithms: stochastic optimization algorithm and dual heuristic programming (DHP) to solve the collective robotic search problem. Experiments were carried out to investigate the effect of noise and the number of robots on the task performance, as well as the expenses. The experimental results showed that the performance of the dual heuristic programming …

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A Numerical Investigation Of Interior Resonances In The Hybrid Fem/Mom Method, Yun Ji, Hao Wang, Todd H. Hubing Jan 2003

A Numerical Investigation Of Interior Resonances In The Hybrid Fem/Mom Method, Yun Ji, Hao Wang, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

The interior resonance problem that can occur when using a hybrid finite-element method/method of moments (FEM/MoM) method to model electromagnetic scattering problems is investigated. Calculations of the bistatic radar cross section of a coated dielectric sphere are presented using different formulations, solution approaches, and solvers. The solutions using the electric-field integral equation have significant errors near an interior resonance frequency. When the combined-field integral equation is employed, satisfactory solutions can be obtained that do not depend on the particular solution approach or solver.

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Bubble Dynamics Measurements Using Four-Point Optical Probe, Junli Xue, Muthanna H. Al-Dahhan, M. P. Dudukovic, R. F. Mudde Jan 2003

Bubble Dynamics Measurements Using Four-Point Optical Probe, Junli Xue, Muthanna H. Al-Dahhan, M. P. Dudukovic, R. F. Mudde

Chemical and Biochemical Engineering Faculty Research & Creative Works

By Conducting an Analysis of the Measurement Errors It Was Found that Bubble Dynamics Obtained by Two-Point Probes Can Be Highly Inaccurate. a Four-Point Optical Probe with Appropriate Data Processing Algorithm Has Been Developed So that the Bubble Velocity Vector Can Be Obtained. This Probe Provides Directly the Value of Specific Gas-Liquid Interfacial Area. However, for Obtaining Accurate Values of Bubble Velocity and Size, the Four-Point Probe Must Be Calibrated by a CCD Camera at the Same Conditions. Calibration Columns Have Been Developed for This Purpose Where the Bubble Size and Velocity Can Be Varied to Calibrate the Measurements by …

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Analysis Of Photobioreactors For Culturing High-Value Microalgae And Cyanobacteria Via An Advanced Diagnostic Technique: Carpt, Hu Ping Luo, Abdenour Kemoun, Muthanna H. Al-Dahhan, J. M.Fernández Sevilla, J. L.García Sánchez, F. García Camacho, E. Molina Grima Jan 2003

Analysis Of Photobioreactors For Culturing High-Value Microalgae And Cyanobacteria Via An Advanced Diagnostic Technique: Carpt, Hu Ping Luo, Abdenour Kemoun, Muthanna H. Al-Dahhan, J. M.Fernández Sevilla, J. L.García Sánchez, F. García Camacho, E. Molina Grima

Chemical and Biochemical Engineering Faculty Research & Creative Works

Photosynthetic Algal Cultures Are a Potential Source of Many High-Value Products. in Photobioreactors (PBR), the Availability and the Intensity of the Light, Which Are Affected by the Cells' Movement, Are the Major Factors Controlling the Biomass Productivity. Hydrodynamics, Hence, Play a Significant Role in the Reactor's Performance, as They Determine Not Only the Flow Field, I.e. Liquid Flow and Mixing, Shear Stresses, Etc., But Also the Movements of the Cells. in This Work, Computer-Automated Radioactive Particle Tracking (CARPT) Technique Was Employed to Evaluate its Feasibility for Characterizing PBRs. Liquid Velocity Profiles, Cells' Movement, and the Temporal Irradiance Patterns Obtained by …

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Instance Based Attribute Identification In Database Integration, Ee Peng Lim, Cecil Chua, Roger Hsiang-Li Chiang Jan 2003

Instance Based Attribute Identification In Database Integration, Ee Peng Lim, Cecil Chua, Roger Hsiang-Li Chiang

Research Collection School Of Computing and Information Systems

Most research on attribute identification in database integration has focused on integrating attributes using schema and summary information derived from the attribute values. No research has attempted to fully explore the use of attribute values to perform attribute identification. We propose an attribute identification method that employs schema and summary instance information as well as properties of attributes derived from their instances. Unlike other attribute identification methods that match only single attributes, our method matches attribute groups for integration. Because our attribute identification method fully explores data instances, it can identify corresponding attributes to be integrated even when schema information …

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Dictionary Of 1913 Baseball And Other Lingo, Vol. Iii (Q-Z), Gerald Leonard Cohen Jan 2003

Dictionary Of 1913 Baseball And Other Lingo, Vol. Iii (Q-Z), Gerald Leonard Cohen

Arts, Languages and Philosophy Faculty Research & Creative Works

No abstract provided.

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Review Of The Coast Of Utopia By Tom Stoppard, David Wohl Jan 2003

Review Of The Coast Of Utopia By Tom Stoppard, David Wohl

College of Visual and Performing Arts Faculty Publications

A Review of The Coast of Utopia by Tom Stoppard, performed by the Royal National Theatre, London, UK, July 2002.

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Frederic Chopin And George Sand Romanticized, Anna Deters Jan 2003

Frederic Chopin And George Sand Romanticized, Anna Deters

Constructing the Past

This article discusses the relationship between Frederic Chopin and George Sand. It focuses on the idea that there are many contradictory accounts of this affair, and that the real truth may not be known.

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Perspectives On An Epidemic: The Yellow Fever In 1793 Philadelphia, Karen Patyk Jan 2003

Perspectives On An Epidemic: The Yellow Fever In 1793 Philadelphia, Karen Patyk

Constructing the Past

This article discusses the Yellow Fever epidemic of 1793, and how there are several different accounts of what happened then. It also notes that the official descriptions given by the doctors of the time are not the entire story and that they leave some important things out.

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The Quest For Identity: A Conversation With John O'Leary, Robert Callahan Jan 2003

The Quest For Identity: A Conversation With John O'Leary, Robert Callahan

Constructing the Past

This article describes a discussion that the author had with John O'Leary, an Irish poet. It discusses the nature of what it means to be "Irish" and "Irish-American" and talks about how many modern people of Irish descent are focusing more on the ancient Irish traditions rather than the stereotypical Irish-American images of famine victims and green beer.

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Sensor Networks: An Overview, Malik Tubaishat, Sanjay Kumar Madria Jan 2003

Sensor Networks: An Overview, Malik Tubaishat, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

Advances in hardware and wireless network technologies have created low-cost, low-power, multifunctional miniature sensor devices. These devices make up hundreds or thousands of ad hoc tiny sensor nodes spread across a geographical area. These sensor nodes collaborate among themselves to establish a sensing network. A sensor network can provide access to information anytime, anywhere by collecting, processing, analyzing and disseminating data. Thus, the network actively participates in creating a smart environment.

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Involving Engineering With In-Service K-4 Teachers, Theresa M. Swift, Steve Eugene Watkins, Kristine Swenson, Evalee Lasater, Robert Mitchell Jan 2003

Involving Engineering With In-Service K-4 Teachers, Theresa M. Swift, Steve Eugene Watkins, Kristine Swenson, Evalee Lasater, Robert Mitchell

Electrical and Computer Engineering Faculty Research & Creative Works

A strong workforce in science and engineering and literate citizens in a technology-based society depends on an educational system that prepares students in science, mathematics, and engineering. Unfortunately, many K-12 students lose interest in such topics early in their school years. Engineering applications can capture the imagination of students and illustrate the concepts in science and mathematics. Level-appropriate resources are as necessary for primary teachers and our young scholars as for teachers and students in higher grades. A model for interaction between engineers and K-4 teachers is proposed. The State of Missouri defines curriculum standards in each subject area and …

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Two Distributed Algorithms For E-Ticket Validation Protocols For Mobile Clients, H. Mohanty, Sanjay Kumar Madria, T. Suman Kumar Reddy, R. K. Ghosh Jan 2003

Two Distributed Algorithms For E-Ticket Validation Protocols For Mobile Clients, H. Mohanty, Sanjay Kumar Madria, T. Suman Kumar Reddy, R. K. Ghosh

Computer Science Faculty Research & Creative Works

The e-ticket (electronic ticket) validation problem has relevance in mobile computing environment because of the multiple submission of a ticket that is possible due to intermittent disconnections and mobility of hosts. Here, we propose protocols that are not only sensitive to disconnection but also to location. One of the proposed protocols is the variant of the distributed protocol proposed by Pedone (2000) for Internet users. This shows that a distributed protocol for static network can be restructured for distributed computation in a mobile computing environment. We have also proposed another protocol that uses a hierarchical location database of mobile hosts …

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Using Psychotherapy Techniques To Reveal Misconceptions And Improve Learning, Paul Michael Santi, Michele M. Santi Jan 2003

Using Psychotherapy Techniques To Reveal Misconceptions And Improve Learning, Paul Michael Santi, Michele M. Santi

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

When students are aware that they do not understand a concept, the main impediment to developing an understanding is their willingness to ask questions of the instructor or of fellow students. When students think that they understand a concept, but really have some significant misconception lodged in their mental picture of the concept, they may not supplant this misconception for years, if ever. Both situations can be corrected if the students identify the need to ask questions, are brave enough to do so in the traditional academic settings, and if the answers adequately address the actual misunderstanding (which may be …

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Web Crippling Of Cold-Formed Steel Beams At End Supports, M. W. Holesapple, Roger A. Laboube Jan 2003

Web Crippling Of Cold-Formed Steel Beams At End Supports, M. W. Holesapple, Roger A. Laboube

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This investigation focused on the effects of overhang length on the web crippling capacity of cold-formed steel members. the current design recommendations in North America do not provide for an increase in web crippling capacity for end-one-flange loading when an overhang is present beyond the end support. the test specimens used for the investigation were single web C-sections and Z-sections. the current design requirements for end-one-flange web crippling capacity were found to be conservative for overhang lengths ranging from 0.5 h to 1.5 h , where h is the web depth. However, the design practice that permits the application of …

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Dynamic Nonlinear Effect On Lasing In Random Media, B. Liu, Alexey Yamilov, Y. Ling, J. Y. Xu, Hui Cao Jan 2003

Dynamic Nonlinear Effect On Lasing In Random Media, B. Liu, Alexey Yamilov, Y. Ling, J. Y. Xu, Hui Cao

Physics Faculty Research & Creative Works

We investigate the dynamic effect of nonlinearity on lasing in disordered medium. The third-order nonlinearity not only changes frequency and size of lasing mode, but also modifies laser emission intensity and laser pulse width.

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Fuzzy Logic In Collective Robotic Search, Nian Zhang, Donald C. Wunsch Jan 2003

Fuzzy Logic In Collective Robotic Search, Nian Zhang, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

One important application of mobile robots is searching a geographical region to locate the origin of a specific sensible phenomenon. We first propose a fuzzy logic approach using a decision table. A novel fuzzy rule based was designed. And then a fuzzy search strategy is adopted by utilizing the three tier centers of mass coordination. Experimental results show that fuzzy logic algorithm is an efficient approach for the collective robots to locate the target source. In addition, noise and the position of the target affect the searching result.

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Implementation Of Adaptive Critic-Based Neurocontrollers For Turbogenerators In A Multimachine Power System, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2003

Implementation Of Adaptive Critic-Based Neurocontrollers For Turbogenerators In A Multimachine Power System, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design and practical hardware implementation of optimal neurocontrollers that replace the conventional automatic voltage regulator (AVR) and the turbine governor of turbogenerators on multimachine power systems. The neurocontroller design uses a powerful technique of the adaptive critic design (ACD) family called dual heuristic programming (DHP). The DHP neurocontroller's training and testing are implemented on the Innovative Integration M67 card consisting of the TMS320C6701 processor. The measured results show that the DHP neurocontrollers are robust and their performance does not degrade unlike the conventional controllers even when a power system stabilizer (PSS) is included, for changes in …

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Locating Moving Objects Over Mobile Sensor Network, Arvind Nath Rapaka, Sandeep Bogollu, Donald C. Wunsch, Ravindra Nath Jan 2003

Locating Moving Objects Over Mobile Sensor Network, Arvind Nath Rapaka, Sandeep Bogollu, Donald C. Wunsch, Ravindra Nath

Electrical and Computer Engineering Faculty Research & Creative Works

The purpose of our on going research would be to track entities, which enter their field of vision over the sensor network. Based on their sightings, they maintain a dynamic cache that can be queried by a base station- a stationary orfixed node. Since transmitting messages consumes a lot of energy, as against local processing and moreover the limited energy in sensor node does not allow heavy duty computing, we need to develop algorithms that will ensure efficient computing and minimal transmission without degradation of performance. and also data is stored locally, and memory is finite, the nodes must choose …

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