Digital Commons Network^™

Range-Dependent Seabed Characterization By Inversion Of Acoustic Data From A Towed Receiver Array, Martin Siderius, Peter L. Nielsen, Peter Gerstoft

Electrical and Computer Engineering Faculty Publications and Presentations

The MAPEX2000 experiments were conducted in the Mediterranean Sea in March, 2000 to determine seabed properties using a towed acoustic source and receiver array. Towed systems are advantageous because they are easy to deploy from a ship and the moving platform offers the possibility for estimating spatially variable (range-dependent) seabed properties. In this paper, seabed parameters are determined using a matched-field geoacoustic inversion approach with measured, towed array data. Previous research has successfully applied matched-field geoacoustic inversion techniques to measured acoustic data. However, in nearly all cases the inverted data were collected on moored, vertical receiver arrays. Results here show …

Application Of Maxwell Solvers To Pd Propagation. I. Concepts And Codes, David Pommerenke, S. Sakaguchi

Electrical and Computer Engineering Faculty Research & Creative Works

This article reviews the basic approaches to solving electromagnetic propagation in the context of PD detection. It also investigates available commercial software, introduces the steps required to obtain trustworthy computational results, and gives an example of detailed analysis of PD propagation.

An Algorithm Applicable To Clearing Combinatorial Exchanges, Marius Silaghi

Electrical Engineering and Computer Science Faculty Publications

It is important to approach negotiations in a way that ensures privacy. So far, research has focused on securely solving restricted classes of negotiation techniques, mainly the (M+1)-st-price auctions. Here we show how these results can be adapted to more general problems. This paper extends our previous results on how distributed finite discrete problems can be solved securely. Such problems can model larger classes of negotiation problems, .e.g. Combinatorial Exchanges [Sil02]. In Finite Discrete Maximization, each tuple in the problem space is associated with an integer value in a predefined interval and we search for a maximizing input. Values from …

Network Traffic Anomaly Detection Based On Packet Bytes, Philip K. Chan, Matthew V. Mahoney

Electrical Engineering and Computer Science Faculty Publications

Hostile network traffic is often "different" from benign traffic in ways that can be distinguished without knowing the nature of the attack. We describe a two-stage anomaly detection system for identifying suspicious traffic. First, we filter traffic to pass only the packets of most interest, e.g., the first few packets of incoming server requests. Second, we model the most common protocols (IP, TCP, telnet, FTP, SMTP, HTTP) at the packet byte level to flag events (byte values) that have not been observed for a long time. This simple system detects 132 of 185 attacks in the 1999 DARPA IDS evaluation …

Automatic Target Recognition Classification System Evaluation Methodology, Christopher Brian Bassham

Theses and Dissertations

This dissertation research makes contributions towards the evaluation of developing Automatic Target Recognition (ATR) technologies through the application of decision analysis (DA) techniques. ATR technology development decisions should rely not only on the measures of performance (MOPs) associated with a given ATR classification system (CS), but also on the expected measures of effectiveness (MOEs). The purpose of this research is to improve the decision-makers in the ATR Technology development. A decision analysis framework that allows decision-makers in the ATR community to synthesize the performance measures, costs, and characteristics of each ATR system with the preferences and values of both the …

A New Approach To Robot’S Imitation Of Behaviors By Decomposition Of Multiple-Valued Relations, Uland Wong, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Relation decomposition has been used for FPGA mapping, layout optimization, and data mining. Decision trees are very popular in data mining and robotics. We present relation decomposition as a new general-purpose machine learning method which generalizes the methods of inducing decision trees, decision diagrams and other structures. Relation decomposition can be used in robotics also in place of classical learning methods such as Reinforcement Learning or Artificial Neural Networks. This paper presents an approach to imitation learning based on decomposition. A Head/Hand robot learns simple behaviors using features extracted from computer vision, speech recognition and sensors.

Automated Synthesis Of Generalized Reversible Cascades Using Genetic Algorithms, Martin Lukac, Mikhail Pivtoraiko, Alan Mishchenko, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

We propose an automated synthesis of Reversible logic (RL) circuits using Darwinian and Lamarckian Genetic Algorithms (GA). Our designs are in a form of cascades of generalized gates which generalize factorized Exclusive-Or-Sum-of-Products (ESOP) circuits. GA can be used to explore the problem space of combinational functions and here it is used to evolve reversible logic circuits. We emphasize the role of problem encoding - a well-designed encoding leads to improved results. Our method with well-encoded circuits is compared to standard method on classical benchmarks in GA, and shows good results for synthesis of both random functions and benchmark functions with …

On The Use Of Singular Perturbations To Neglect The Dynamic Saliency Of Synchronous Machines, Steven D. Pekarek, Michael T. Lemanski, Eric A. Walters

Electrical and Computer Engineering Faculty Research & Creative Works

A common approximation used in the analysis of power systems is the neglect of the dynamic saliency in synchronous machines. In this paper, it is shown that eliminating the error associated with neglecting dynamic saliency can be accomplished with the addition of a singular perturbation(s) into the machine model. By considering the elimination of error in such a way, singular-perturbation-based model-order-reduction techniques are used to derive detailed- and reduced-order models of synchronous machines where dynamic saliency is eliminated with zero error and no added numerical cost.

Adaptive Ds-Cdma Multiuser Detection For Time Variant Frequency Selective Rayleigh Fading Channel, Xin Tang

Dissertations

The current digital wireless mobile system such as IS-95, which is based on direct sequence Code Division Multiple Access (DS-CDMA) technology, will not be able to meet the growing demands for multimedia service due to low information exchanging rate. Its capacity is also limited by multiple accessed interference (MAI) signals.

This work focuses on the development of adaptive algorithms for multiuser detection (MUD) and interference suppression for wideband direct sequence code division multiple access (DS-CDMA) systems over time-variant frequency selective fading channels. In addition, channel acquisition and delay estimation techniques are developed to combat the uncertainty introduced by the wireless …

On Chip Implement Of Deadlock Avoidance In Wormhole Networks, Kiran K. Gururaj

Theses

This thesis gives a detailed description of the Application Specific Integrated Circuit (ASIC) design to avoid deadlocks in Wormhole Networks. Deadlock avoidance is the most critical issue while considering wormhole networks and should be avoided by any routing protocol and algorithm. A novel architecture for the Turn Prohibition Based Routing (TPBR) protocol has been proved to be efficient and was developed as a part of this work. This architecture for implementing the algorithm is divided into three parts. The first part determines the order of selccuon of the nodes, in the network to run the algorithm. The second part deals …

New Plane Wave Representation Of Point Sources, L. (Lijun) J. Jiang, W. C. Chew

Electrical and Computer Engineering Faculty Research & Creative Works

A new method to decompose the spherical wave of a 3D point source into plane waves is discussed. Using Cauchy's theorem, it represents spherical waves as the summation of surface-direction-wave integrals. Results show that only 6 directions waves needed storage. Thus, the method provides a good cost reduction for plane-wave related algorithms.

Sum Normal Optimization Of Fuzzy Membership Functions, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

Given a fuzzy logic system, how can we determine the membership functions that will result in the best performance? If we constrain the membership functions to a certain shape (e.g., triangles or trapezoids) then each membership function can be parameterized by a small number of variables and the membership optimization problem can be reduced to a parameter optimization problem. This is the approach that is typically taken, but it results in membership functions that are not (in general) sum normal. That is, the resulting membership function values do not add up to one at each point in the domain. This …

Temporal Modeling Of Software Test Coverage, Sahra Sedigh, Arif Ghafoor, Raymond A. Paul

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a temporal model for the coverage achieved by software testing. The proposed model, which is applicable at any level of the testing hierarchy, can determine the value of test coverage at any given time, as well as predicting future values. The model is comprised of two main components: coverage functions, and the coverage matrix. The coverage functions represent the coverage of a single entity as a function of time and reflect the test environment through their stochastic parameters. The coverage matrix utilizes the coverage functions to depict the coverage attained for each entity by each test within …

Quality Enhancement Of Reconfigurable Multichip Module Systems By Redundancy Utilization, Minsu Choi, Nohpill Park, Fabrizio Lombardi, Vincenzo Piuri

Electrical and Computer Engineering Faculty Research & Creative Works

This paper evaluates the quality effectiveness of redundancy utilization in reconfigurable multichip mode (RMCM) systems. Due to reconfigurability, the RMCM system can implement a device with different redundancy levels. A redundancy level is determined by the requirement of fault tolerance (FT) of the device under implementation which can be realized through reconfiguration. No previous work has adequately investigated the effect of utilization of redundancy on the quality-level (QL) of RMCM. In this paper, the tolerance to escape from testing is also introduced to provide more extensive and comprehensive analysis and is referred to as escape tolerance (ET). This can be …

Analysis Of Error Recovery Effects On Digital Flight Control Systems, Arturo Tejada Ruiz

Electrical & Computer Engineering Theses & Dissertations

Life-critical, real-time applications like flight-by-wire aircraft, rely on closed-loop digital control systems and fault-tolerant computer systems to reliably achieve the desired operation. The computer systems, however, may be affected by random hardware/software faults induced mainly by environmental conditions such as high intensity radiated fields (HIRF) and lightning. These harsh electromagnetic environments are known to induce common­ mode faults (CMF) in aircraft electronic systems, which disrupt fault-tolerant provisions and possibly affect the operation of the digital control system. Current flight-by-wire aircraft have computer systems that can neither detect CMF nor recover from them. New systems are under investigation that can recover …

Study Of Non-Equilibrium Electron Dynamics In Metals, Wael Mohamed Gomaa Ibrahim

Electrical & Computer Engineering Theses & Dissertations

Thermal phenomena, such as heat propagation, lattice melting, and ablation, are the result of energy deposition in metals. A fundamental understanding of the electron dynamics leading to these thermal phenomena would benefit many laser applications, such as laser deposition of thin films and laser processing.

In this work, thin metal films were prepared using the resistive heating evaporation technique. High dynamic range autocorrelators were constructed to characterize the different laser systems used in this study. The nonequilibrium electron dynamics in single layer gold films, multi-layer gold-vanadium, and gold-titanium films were studied. The time evolution of the electron temperature was monitored …

Excimer Emission From Pulsed Microhollow Cathode Discharges, Mohamed Moselhy

Electrical & Computer Engineering Theses & Dissertations

Microhollow cathode discharges (MHCDs) are direct current, high-pressure, non-equilibrium gas discharges. Direct current MHCDs in xenon and argon have shown to emit excimer radiation at 172 and 127 nm, respectively. Internal efficiency of excimer emission in DC MHCD was measured to be 6–9% in xenon, and 1–6%, depending on the gas flow rate in argon. This high efficiency is due to the high rate of rare gas excitation by electrons accelerated in the cathode fall and to subsequent three-body collisions in the high-pressure gas. The excimer power scales linearly with current; however, due to the increasing size of the source …

Eye Pattern Evaluation In High-Speed Digital Systems Analysis By Using Mtl Modeling, Giulio Antonini, James L. Drewniak, Antonio Orlandi, Vittorio Ricchiuti

Electrical and Computer Engineering Faculty Research & Creative Works

A method for simulating the eye pattern of high-speed digital signals propagated on printed circuit boards using multiconductor transmission-line modeling is proposed in this paper. The approach takes into account the frequency-dependent properties of the dielectric materials of the board and of the conductors. The validation is performed by comparing the modeling with measurements taken from the literature, and directly performed on test boards specially design for this study.

A Course Assessment Of The Microelectronics Process Engineering Program At Sjsu, Gregory Young, Stacy H. Gleixner, David W. Parent, Yasser Dessouky, Emily Allen, Linda Vanasupa

Faculty Publications

The program assessment strategy of San Jose State University's new interdisciplinary curriculum in Microelectronics Process Engineering is described. Vertical integration of specific class and program learning objectives allows for a clear and efficient method to evaluate the continued growth and improvement of the program. The program assessment process relies on clearly defined and detailed program and course learning objectives that are linked vertically to ABET outcomes. In addition, we discuss briefly the structure of the program and the "hands-on" experience that we provide the students.

Nonresonant Detection Of Terahertz Radiation In Field Effect Transistors, W. Knap, V. Kachorovskii, Y. Deng, S. Rumyantsev, J.-Q. Lü, R. Gaska, M. S. Shur, Grigory Simin, X. Hu, M. Asif Khan, C. A. Saylor, L. C. Brunel

Faculty Publications

We present an experimental and theoretical study of nonresonant detection of subterahertz radiation in GaAs/AlGaAs and GaN/AlGaN heterostructurefield effect transistors. The experiments were performed in a wide range of temperatures (8–300 K) and for frequencies ranging from 100 to 600 GHz. The photoresponse measured as a function of the gate voltage exhibited a maximum near the threshold voltage. The results were interpreted using a theoretical model that shows that the maximum in photoresponse can be explained by the combined effect of exponential decrease of the electron density and the gate leakage current.

Validation Of Sea Ice Motion From Quikscat With Those From Ssm/I And Buoy, David G. Long, Yunhe Zhao, Antony K. Liu

Faculty Publications

Arctic sea ice motion for the period from October 1999 to March 2000 derived from QuikSCAT and ocean buoy observations. Special Sensor Microwave/Imager (SSM/I) data using the wavelet analysis method agrees well with ocean buoy observations. Results from QuikSCAT and SSM/I are compatible when compared with buoy observations and complement each other. Sea ice drift merged from daily results from QuikSCAT, SSM/I, and buoy data gives more complete coverage of sea ice motion. Based on observations of six months of sea ice motion maps, the sea ice motion maps in the Arctic derived from QuikSCAT data appear to have smoother …

Dynamic Multiphysics Model For Solar Array, Shengyi Liu, Roger A. Dougal

Faculty Publications

An approach to model the solar cell system with coupled multiphysics equations (photovoltaic, electro-thermal, direct heating and cooling processes) within the context of the resistive-companion method in the Virtual Test Bed computational environment is presented. Appropriate across and through variables are defined for the thermal terminal of the system so that temperature is properly represented as a state variable, rather than as a parameter of the system. This allows enforcement of the system power conservation through all terminals, and allows simultaneous solutions for both the electrical potentials and the system temperature. The thermal port built accordingly can be used for …

Closed Loop Identification Of A First Order Plus Dead Time Process Model Under Pi Control, Tony Kealy, Aidan O'Dwyer

Conference papers

Abstract -- This paper discusses the estimation of the parameters of a first order plus dead-time process model using the closed-loop step response data of the process under proportional plus integral (PI) control. The proportional gain and the integral time, in the PI controller, are chosen such that the closed-loop step response exhibits an under-damped response. From this response data, five characteristic points are used to determine a second order plus dead-time model and subsequently, the frequency response of the closed-loop system. Knowing the dynamics of the closed-loop system and the dynamics of the controller, the open-loop dynamics of the …

Theory And Design Of Mixed Lumped-Distributed Cross-Coupled Filters With Applications To Linear Phase Shifter And Tunable Filters, Sanghoon Shin

Dissertations

Using cross-coupled networks of a new concept, transmission zeros were efficiently located in the complex frequency-domain. With this approach, the group delay and attenuation slope of the circuit network can be controlled to get both sharp rejection characteristics and linear phase slopes. In order to achieve this performance, various types of combline filters are suggested. Various simulation tools (commercial linear circuit and E-M simulators), as well as the developed pole-zero locator program, were used to design a new class of cross-coupled networks. In particular, the polezero locator program can be used to extract an equivalent circuit of the topology that …

Determination Of Phase Composition Of Sputtered Tantalum On Steel Substrates By Resistivity Measurements, Younes Abbassi

Theses

The objective of this thesis was to develop a method of distinguishing between alpha and beta phases of tantalum films on steel substrates, using the four-point probe resistivity measurements. While there is a large difference between resistivities of the two Ta phases, the problem is challenging because the measurements are influenced by the low resistivity of steel.

For reference, the resistivity measurements of tantalum coatings (1-20 μm) on silicon and silicon dioxide substrates were conducted first. The measured resistivities were related to the crystallographic phase composition of Ta, which has lower resistivity in bcc form, α-phase, (13.5 to 42 μΩcm), …

Stereo Matching Algorithm By Propagation Of Correspondences And Stereo Vision Instrumentation, Peerajak Witoonchart

Theses

A new image processing method is described for measuring the 3-D coordinates of a complex, biological surface. One of the problems in stereo vision is known as the accuracy-precision tradeoff problem. This thesis proposes a new method that promises to solve this problem. To do so, two issues are addressed. First, stereo vision instrumentation methods are described. This instrumentation includes a camera system as well as camera calibration, rectification, matching and triangulation. Second, the approach employs an array of cameras that allow accurate computation of the depth map of a surface by propagation of correspondences through pair-wise camera views.

The …

A Model Of Plasma Frequency Probes Utilizing Plasma Fluid Equations And Finite Difference Time Domain (Fdtd) Theory, Jeffrey D. Ward

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As man continues to search the unknown, additional tools are needed to develop and analyze new probes. This thesis will present a full wave Finite Difference Time Domain model that is capable of analyzing radio frequency probes immersed in realistic ionospheric plasma. The five moment approximations, Maxwell's equations and the plasma fluid equations, are discretized using a finite difference time domain method. Balmain's and Adachi theories are used to validate the simulation at the gyro and hybrid resonance points. Finally, with the model developed, the simulation is used to analyze a microstrip patch plasma impedance probe immersed in hot collisional …

Oxygen Plasma Effects On Optical Properties Of Znse Films, Li Yan, John A. Woollam, Eva Franke

Department of Electrical and Computer Engineering: Faculty Publications

Zinc selenide is an infrared transparent semiconductor material being considered for use in space as an infrared optical coating. In this work, zinc selenide thin films of different thicknesses were exposed to an electron cyclotron resonance generated oxygen plasma, often used to ‘‘simulate’’ the low earth orbital environment. The maximum fluence used in our experiments was equivalent to ~16 years in the low earth orbital environment. ZnSe thin film optical constants (both before and after oxygen plasma exposure) were determined using variable angle spectroscopic ellipsometry from the vacuum ultraviolet at 146 nm through the middle infrared to 40 μm. A …

Cancellation Of Mri Motion Artifact In Image Plane, Eung-Kyeu Kim, Nohpill Park, Minsu Choi, S. Tamura

Electrical and Computer Engineering Faculty Research & Creative Works

In this study, a new algorithm for canceling a MRI artifact due to the translational motion in image plane is described. Unlike the conventional iterative phase retrieval algorithm, in which there is no guarantee for the convergence, a direct method for estimating the motion is presented. In previous approaches, the motions in the x(read out) direction and the y(phase encoding) direction were estimated simultaneously. However, the feature of x and y directional motions are different from each other. By analyzing their features, each x and y directional motion is canceled by the different algorithms in two steps. First, it is …

Comparision Of Measured Convection Velocities With Calcuulations Based On Electric Potential Model, Daniel E. Britton

Honors Capstone Projects and Theses

No abstract provided.