Engineering Commons^™

Distributed Fault Tolerance In Optimal Interpolative Nets, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

The recursive training algorithm for the optimal interpolative (OI) classification network is extended to include distributed fault tolerance. The conventional OI Net learning algorithm leads to network weights that are nonoptimally distributed (in the sense of fault tolerance). Fault tolerance is becoming an increasingly important factor in hardware implementations of neural networks. But fault tolerance is often taken for granted in neural networks rather than being explicitly accounted for in the architecture or learning algorithm. In addition, when fault tolerance is considered, it is often accounted for using an unrealistic fault model (e.g., neurons that are stuck on or off …

A Comparison Of Facts Integrated With Battery Energy Storage Systems, Lin Zhang, Shen Chen, Stan Atcitty, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

The integration of energy storage into FACTS devices lead to increased controller flexibility by providing decentralized active power capabilities. Combined FACTS/ESS can improve power flow control, oscillation damping and voltage control. This paper presents a comparison between the dynamic performance of a StatCom, a StatCom/BESS, an SSSC, an SSSC/BESS and a UPFC. Experimental verification is also presented.

Stacked Subwavelength Gratings As Circular Polarization Filters, Gregory P. Nordin, P. C. Deguzman

Faculty Publications

We have stacked subwavelength gratings (SWGs) on a single substrate to create a compact, integrated circular polarization filter. The SWGs consist of a wire grid polarizer and a broadband form-birefringent quarter-wave plate (QWP). Rigorous coupled-wave analysis was used to design the QWP for operation over the 3.5-5.0 m wavelength range. The fabricated silicon broadband QWP exhibited a phase retardance of 82-97° across this wavelength range. Two stacked structures are presented, each with a different wire grid polarizer fabricated on an organic planarization layer (SU-8) that is deposited on a QWP grating. Transmittance measurements of the first structure when illuminated with …

Emi Mitigation With Multilayer Power-Bus Stacks And Via Stitching Of Reference Planes, Xiaoning Ye, David M. Hockanson, Min Li, Yong Ren, Wei Cui, James L. Drewniak, Richard E. Dubroff

Electrical and Computer Engineering Faculty Research & Creative Works

General methods for reducing printed circuit board (PCB) emissions over a broad band of high frequencies are necessary to meet EMI requirements, as processors become faster and more powerful. One mechanism by which EMI can be coupled off a PCB or multichip module (MCM) structure is from high-frequency fringing electric fields on the dc power and reference planes at the substrate periphery An approach for EMI mitigation by stitching multiple ground planes together along the periphery of multilayer PCB power-bus stacks with closely spaced vias is reported and quantified in this paper. Power-bus noise induced EMI and coupling from the …

Dc Power-Bus Design Using Fdtd Modeling With Dispersive Media And Surface Mount Technology Components, Xiaoning Ye, Marina Koledintseva, Min Li, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

DC power-bus modeling in high-speed digital design using the finite-difference time-domain (FDTD) method is demonstrated herein. The dispersive character of the dielectric layers used in printed circuit board substrates is taken into account in this study. In particular, FR-4 is considered. The complex permittivity of the dielectric is approximated by a Debye model. A wide-band frequency response (100 MHz-5 GHz) is obtained through a single FDTD simulation. Good agreement is achieved between the modeled and measured results for a typical dc power-bus structure with multiple surface mount technology (SMT) decoupling capacitors placed on the printed circuit board (PCB). The FDTD …

Sampling Switch Having An Independent "On" Impedance, Adrian K. Ong, Vladimir I. Prodanov, Maurice J. Tarsia

Electrical Engineering

A sampling device for sampling an input signal in response to a pulse train of a sample signal. The sampling device includes a sampling transistor for creating samples in response to the sample signal. The sampling transistor has an impedance corresponding with the difference between the gate to source voltage and the threshold voltage of the sampling transistor. The sampling device also includes a control device for generating a control signal. The control device includes a bootstrap reference voltage source for providing a reference voltage in response to the sample signal, and a control circuit for generating the control circuit …

Si3N4/Algan/Gan-Metal-Insulator-Semiconductor Heterostructure Field-Effect Transistors, X. Hu, A. Koudymov, Grigory Simin, J. Yang, M. Asif Khan, A. Tarakji, M. S. Shur, R. Gaska

Faculty Publications

We report on a metal–insulator–semiconductor heterostructurefield-effect transistor (MISHFET) using Si₃N₄ film simultaneously for channel passivation and as a gate insulator. This design results in increased radio-frequency (rf) powers by reduction of the current collapse and it reduces the gate leakage currents by four orders of magnitude. A MISHFET room temperature gate current of about 90 pA/mm increases to only 1000 pA/mm at ambient temperature as high as 300 °C. Pulsed measurements show that unlike metal–oxide–semiconductor HFETs and regular HFETs, in a Si₃N₄ MISHFET, the gate voltage amplitude required for current collapse is much higher …

Statistical Evaluation Of Image Quality Measures, Ismail Avcibas, Bulent Sankur, Khalid Sayood

Department of Electrical and Computer Engineering: Faculty Publications

In this work we comprehensively categorize image quality measures, extend measures defined for gray scale images to their multispectral case, and propose novel image quality measures. They are categorized into pixel difference-based, correlation-based, edge-based, spectral-based, context-based and human visual system (HVS)-based measures. Furthermore we compare these measures statistically for still image compression applications. The statistical behavior of the measures and their sensitivity to coding artifacts are investigated via analysis of variance techniques. Their similarities or differences are illustrated by plotting their Kohonen maps. Measures that give consistent scores across an image class and that are sensitive to coding artifacts are …

A Java-Applet-Based Three-Phase Power System Harmonics Simulator, Taufik, Linda Kakinami

Electrical Engineering

This paper presents the development of a Java applet to simulate three-phase power system when harmonics is being introduced. The applet-based makes the simulator a very useful visual tool in understanding how harmonics affects the shape of sinusoidal waveform and thus the quality of power resulted thereof. The use of Java applet also enables the simulator to be run through internet via web-browser, and hence improves its availability and accessibility. The skeleton of the simulator will first be described. Then, discussion on how to operate the simulator follows which includes an example with snapshots to demonstrate the execution of the …

Induced Strain Mechanism Of Current Collapse In Algan/Gan Heterostructure Field-Effect Transistors, Grigory Simin, A. Koudymov, A. Tarakji, X. Hu, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska

Faculty Publications

Gated transmission line model pattern measurements of the transient current–voltage characteristics of AlGaN/GaN heterostructurefield-effect transistors(HFETs) and metal–oxide–semiconductor HFETs were made to develop a phenomenological model for current collapse. Our measurements show that, under pulsed gate bias, the current collapse results from increased source–gate and gate–drain resistances but not from the channel resistance under the gate. We propose a model linking this increase in series resistances (and, therefore, the current collapse) to a decrease in piezoelectriccharge resulting from the gate bias-induced nonuniform strain in the AlGaN barrier layer.

Siptool: The 'Signal And Image Processing Tool' An Engaging Learning Environment, Fred W. Depiero

Electrical Engineering

The ‘Signal and Image Processing Tool’ is a multimedia software environment for demonstrating and developing Signal & Image Processing techniques. It has been used at Cal Poly for three years. A key feature is extensibility via C/C++ programming. The tool has a minimal learning curve, making it amenable for weekly student projects. The software distribution includes multimedia demonstrations ready for classroom or laboratory use. SIPTool programming assignments strengthen the skills needed for life-long learning by requiring students to translate mathematical expressions into a standard programming language, to create an integrated processing system (as opposed to simply using canned processing routines).

Modeling And Test Of Pixel Cross-Talk In Hgcdte Focal Plane Arrays, Thomas J. Sanders, E. Lee Caraway, Glenn T. Hess, Gwendolyn W. Newsome, Theodore Fischer

Electrical Engineering and Computer Science Faculty Publications

Mercury Cadmium Telluride focal plane arrays with well over 1000 pixels have been fabricated for a number of years. These FPA's have been built as large two-dimensional arrays of HgCdTe p-n junction diodes on a single CdTe or CdZnTe substrate. Sensitivity of each pixel to impinging radiation is one of the most important quality factors for these devices. However, material parameters, which give diode high sensitivity, are the same as those that cause cross talk between adjacent diodes in the array. This cross talk causes a blurred image and in general is a detrimental factor for the FPA system. The …

Detecting Novel Attacks By Identifying Anomalous Network Packet Headers, Philip K. Chan, Matthew V. Mahoney

Electrical Engineering and Computer Science Faculty Publications

We describe a simple and efficient network intrusion detection algorithm that detects novel attacks by flagging anomalous field values in packet headers at the data link, network, and transport layers. In the 1999 DARPA off-line intrusion detection evaluation test set (Lippmann et. al. 2000), we detect 76% of probes and 48% of denial of service attacks (at 10 false alarms per day). When this system is merged with the 18 systems in the original evaluation, the average detection rate for attacks of all types increases from 61% to 65%. We investigate the effect on performance when attack free training data …

Completeness Of Propositional Logic As A Program, Ryan Stansifer

Electrical Engineering and Computer Science Faculty Publications

The proof of completeness for propositional logic is a constructive one, so a computer program is suggested by the proof. We prove the completeness theorem for Łukasiewicz’ axioms directly, and translate the proof into the functional languages SML and Haskell. In this paper we consider this proof as a program. The program produces enormous proof trees, but it is, we contend, as good a proof of completeness as the standard mathematical proofs.The real value of the exercise is the further evidence it provides that typed, functional languages can clearly express the complex abstractions of mathematics.

Very Fast Tree-Structured Vector Quantization, Todd K. Moon, Christian B. Peel, Scott E. Budge

Electrical and Computer Engineering Faculty Publications

Very fast tree-structured vector quantization employs scalar quantization decisions at each level, but chooses the dimension on which to quantize based on the coordinate direction of maximum variance. Because the quantization is scalar, searches are no more complex than scalar quantization - providing significant improvement in complexity over full-searched or even tree-structured vector quantization - but the method preserves the shape and memory advantages of conventional vector quantization. However, the space filling advantage of VQ is forfeited, since each Voronoi cell is a rectangular cuboid.

The Effects Of Via Transitions On Differential Signals, Chen Wang, Jun Fan, James L. Knighten, Norman W. Smith, Ray Alexander, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Vias in differential transmission lines have been modeled using the finite-difference time-domain (FDTD) method. The velocity that the differential signal propagated through the vias was estimated. Differential S-parameters were calculated up to 50 GHz. Below 10 GHz, the differential signal can propagate through vias without much reflection and distortion. However, as frequency increases, the reflection from the vias and the loss of differential power become significant.

A Simple, Robust, And On-Site Microwave Technique For Determining Water-To-Cement Ratio (W/C) Of Fresh Portland Cement-Based Materials, K. Mubarak, Karl Joseph Bois, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Inspection and evaluation of cement-based materials such as concrete is of great interest to the construction industry. In particular, real-time and on-site evaluation of water-to-cement ratio (w/c) is an important practical issue, since the compressive strength of a concrete structure is significantly influenced by its w/c. Currently, there is no single real-time, on-site, relatively in-expensive, easy-to-implement, and operator friendly technique for evaluating this parameter. Microwave nondestructive testing and evaluation techniques have shown great promise when used for inspection and evaluation of the properties of cement-based materials. In this paper, the optimal design of a monopole antenna probe used to evaluate …

Metrics-Guided Quality Management For Component-Based Software Systems, Sahra Sedigh, Arif Ghafoor, Raymond A. Paul

Electrical and Computer Engineering Faculty Research & Creative Works

The growing reliance on commercial-off-the-shelf (COTS) components for developing large-scale projects introduces a new paradigm in software Engineering; which requires the design of new software development and business processes. Large scale component reuse leads to savings in development resources, enabling these resources to be applied to areas such as quality improvement. These savings come at the price of integration difficulties, performance constraints, and incompatibility of components from multiple vendors. Relying on COTS components also increases the system''s vulnerability to risks arising from third-party development, which can negatively affect the quality of the system, as well as causing expenses not incurred …

Gaussian Beams In Hollow Metal Waveguides: Experiment, Marius Ghita, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Gaussian beams have been widely used for propagating electromagnetic waves in free space and in certain other optical systems. It has been suggested that recurring forms of such beams might also be useful for propagation in planar or rectangular metal waveguides. Experimental verification of the recurrence of the Gaussian field distribution in metal waveguides is reported here.

A Cmos Agc-Less If Strip For Bluetooth, Vladimir I. Prodanov, George Palaskas, Jack Glas, Vito Boccuzzi

Electrical Engineering

This paper presents an IF chain suitable for Low-IF fully-integrated GFSK receivers. The circuit performs amplification and channel selection (including image rejection). A five-pole Gm-C polyphase filter forms the core of the IF strip. The filter is current driven and has transimpedance gain of ≃ 120 kΩ. The filter is architectured so that GFSK signals with dynamic range exceeding 50dB can be decoded without the need of any automatic gain control. This AGC-less IF strip was fabricated in standard 0.25 µm CMOS process. It draws 6.2 mA from a 2.5 V supply and has better than 4.8 nA rms input …

Length Selectable, Hardware Efficient Pseudorandom Code Generator, John F. Brendle Jr., James P. Stephens Sr., Michael A. Temple, Robert S. Parks

AFIT Patents

A method and device for generating a pseudorandom electrical signal for enabling spread spectrum communication scrambling by directing data entry into pseudorandom number generator integrated circuit chip controlling registers using a length selectable feedback logic data sequence and either computer programmable selector means or manual selector means to communicate the logic data sequence characters to buffers. The logic data sequence characters are clocked to a pseudorandom number generating register of an integrated circuit chip and the pseudorandom electrical signal is generated by selectively tapping a signal code therefrom. The method and device features a pseudorandom electrical signal length varying capability …

Indium-Silicon Co-Doping Of High-Aluminum-Content Algan For Solar Blind Photodetectors, V. Adivarahan, Grigory Simin, G. Tamulaitis, R. Srinivasan, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska

Faculty Publications

We report on an indium–silicon co-doping approach for high-Al-content AlGaN layers. Using this approach, very smooth crack-free n-type AlGaN films as thick as 0.5 μm with Al mole fraction up to 40% were grown over sapphire substrates. The maximum electron concentration in the layers, as determined by Hall measurements, was as high as 8×10¹⁷ cm⁻³ and the Hall mobility was up to 40 cm²/Vs. We used this doping technique to demonstrate solar-blind transparent Schottky barrierphotodetectors with the cut-off wavelength of 278 nm.

Characterization Of Two-Dimensional Finite-Aperture Wire Grid Polarizers By A Spectral-Domain Technique, Michael A. Jensen, Gregory P. Nordin

Faculty Publications

We investigate the transmission characteristics of perfectly conducting two-dimensional wire grid polarizers fabricated in finite and infinite apertures using a rigorous spectral-domain mode-matching method. Specifically, the transmission coefficient for both transverse-electric and transverse-magnetic polarizations, extinction ratio, and diffraction pattern are characterized for a wide variety of geometric and material parameters including aperture dimension, conducting wire fill factor, wire spacing, polarizer thickness, material dielectric constants, and incident wave arrival angle. The results indicate that the transmission behavior is largely insensitive to aperture dimension.

Dsp-Based Field-Oriented Step Motor Control, Daniel J. Simon, Dennis L. Feucht

Electrical and Computer Engineering Faculty Publications

The SMC3 motor drive has been built using an Analog Devices ADSP-2101 digital signal processor (DSP). The SMC3 is designed to work with two-phase step motors, which are permanent magnet motors with many (typically 100) poles. The firmware in the SMC3 DSP drives the step motor phase windings using field-oriented control rather than using single steps. This method derives the maximum theoretical performance from the motor. This paper describes field-oriented control, and how the SMC3 hardware and firmware implements it.

Proxy Servers For Scalable Interactive Video Support, Husni Fahmi, Mudassir Latif, Sahra Sedigh, Arif Ghafoor, Peiya Liu, Liang Hsu

Electrical and Computer Engineering Faculty Research & Creative Works

Targeting scalability, load balance and resource efficiency in streaming multimedia applications, proxy servers facilitate faster real-time access to cached objects and reduce response time to document requests.

Using Neural Networks To Estimate Wind Turbine Power Generation, Shuhui Li, Donald C. Wunsch, Edgar O'Hair, Michael G. Giesselmann

Electrical and Computer Engineering Faculty Research & Creative Works

This paper uses data collected at Central and South West Services Fort Davis wind farm to develop a neural network based prediction of power produced by each turbine. The power generated by electric wind turbines changes rapidly because of the continuous fluctuation of wind speed and direction. It is important for the power industry to have the capability to perform this prediction for diagnostic purposes—lower-than-expected wind power may be an early indicator of a need for maintenance. In this paper, characteristics of wind power generation are first evaluated in order to establish the relative importance for the neural network. A …

Implicit Algorithms For Multi-Valued Input Support Manipulation, Alan Mishchenko, Craig Files, Marek Perkowski, Bernd Steinbach, Christina Dorotska

Electrical and Computer Engineering Faculty Publications and Presentations

We present an implicit approach to solve problems arising in decomposition of incompletely specified multi-valued functions and relations. We introduce a new representation based on binaryencoded multi-valued decision diagrams (BEMDDs). This representation shares desirable properties of MDDs, in particular, compactness, and is applicable to weakly-specified relations with a large number of output values. This makes our decomposition approach particularly useful for data mining and machine learning. Using BEMDDs to represent multi-valued relations we have developed two complementary input support minimization algorithms. The first algorithm is efficient when the resulting support contains almost all initial variables; the second is efficient when …

Arq Protocol For Joint Source And Channel Coding And Its Applications, Bin He

Dissertations

Shannon's separation theorem states that for transmission over noisy channels, approaching channel capacity is possible with the separation of source and channel coding. Practically, the situation is different. Infinite size blocks are needed to achieve this theoretical limit. Also, time-varying channels require a different approach. This leads to many approaches for source and channel coding. This dissertation will address a joint source and channel coding that suits Automatic Repeat Request (ARQ) application and applies it to packet switching networks. Following aspects of the proposed joint source and channel coding approach will be presented:

1. The design of the proposed joint source …

Saturation Routing For Asynchronous Transfer Mode (Atm) Networks, Jose Luis Ucles

Dissertations

The main objective of this thesis is to show that saturation routing, often in the past considered inefficient, can in fact be a viable approach to use in many important applications and services over an Asynchronous Transfer Mode (ATM) network. For other applications and services, a hybrid approach (one that partially uses saturation routing) is presented. First, the minimum effects of saturation routing are demonstrated by showing that the ratio, defined as f, of routing overhead cells over information cells is small even for large networks. Second, modeling and simulation and M/D/l queuing analysis techniques are used to show that …

Current Oscillations In The System Of Carbon Steel/Phosphoric Acid/Platinum, Shao-Yuan Shi, Jin-Ping Wu, Jing Liu, An Lin

Journal of Electrochemistry

The periodic,aperiodic, chaotic and mixed-mode oscillations can occur in the process of the anodic electrodissolution of carbon steel in the solution of dilute phosphoric acid. More plentiful dynamic behaviors can be found in this system compared with the system of Fe/H₃PO₄/Pt.