Engineering Commons^™

Highly Innovative And Rapid Turn-Around Space Test Program, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Highly Innovative and Rapid Turn-around Space Test Program" from October 23, 2001.

Lightweight Cigs2 Thin-Film Solar Cells On Stainless Steel Foil, Florida Solar Energy Center, Neelkanth Dhere

FSEC Energy Research Center®

AM 0 PV parameters of large-grain, {112} orientated chalcopyrite CIGS2 thin films solar cells on 127µm thick SS flexible foil for space power were: V_oc = 802.9 mV, J_sc = 25.07 mA/cm², FF = 60.06%, and efficiency 0 = 8.84%. Detailed current versus voltage analysis gave values of series resistance Rs, shunt resistance Rp, diode factor A, and reverse saturation current Jo of ~0.1 Ω cm2, ~600 Ω cm2, ~2.2 and ~1.85x10^-8 A cm^-2 respectively. A sharp QE cutoff was observed at CIGS2 bandgap of ~1.50 eV. Higher foil roughness resulted in a preliminary …

Ultrasonic Characterization Of Poling In Lead Zirconate Titanate Ceramics, James R. Friend, Eric Jamieson, Marvin Pennell, Wayne Huebner

Materials Science and Engineering Faculty Research & Creative Works

A method for measuring the spatial variation of the macroscopic poling state of a piezoelectric material using an ultrasonic transducer is described. The relatively simple method clearly indicates the distribution of poling within the material, demonstrated by the testing of a collection of partially poled lead zirconate titanate samples.

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 …

“Walk” Evolution Of The Cubesat Concept, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Walk: Evolution of the CubeSat Concept" and presented at the Western Region NASA Space Grant Consortium on October 19, 2001.

Oct 2001, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Software Program Storage Space Needed 16 new members

Highly Plasma Etch-Resistant Photoresist Composition Containing A Photosensitive Polymeric Titania Precursor, Tony D. Flaim, Douglas J. Guerrero, Michelle R. Fowler, William Joseph James, Vladimir Petrovsky, Harlan U. Anderson

Chemistry Faculty Research & Creative Works

A composition is derived from an addition polymerizable organotitanium polymer which upon exposure to an oxygen plasma or baking in air, is converted to titanium dioxide (titania) or is converted to a mixed, titanium-containing metal oxide. The metal oxide formed in situ imparts etch- resistant action to a patterned photoresist layer. The composition may also be directly deposited and patterned into permanent metal oxide device features by a photolithographic process.

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.

Automatic Compact Disc Transfer For Quality Assurance Testing, Ravi P. Ramachandran, John Chen, Linda M. Head, John L. Schmalzel, Hampton C. Gabler

Mechanical Engineering

The purpose of this project was to design, build and test a low cost prototype that transfers compact discs (CDs) from a spindle to a computer based testing station. This will speed up the CD production/testing interface and eliminate the need for manual operation. Along with a heavy product design technical component, the project included a real life educational experience for the four students who got credit for a one year advanced senior project. Various designs were considered and the optimal design (based on cost and performance) was prototyped.

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).

The Current State Of Research On Academic Dishonesty Among Engineering Students, Trevor S. Harding, Donald D. Carpenter, Susan M. Montgomery, Nicholas H. Steneck

Materials Engineering

Academic dishonesty, or cheating, has become a serious problem at colleges and universities. This is particularly true of engineering students who, are among the most likely to cheat in college. The present paper reviews the literature as a basis of broadly understanding academic dishonesty. This discussion focuses on three primary issues: (1) perceptions of and attitudes towards cheating, (2) reasons for student cheating, and (3) methods of promoting academic integrity. A current research project being developed by the authors is also discussed. The premise of this research is that students are constantly making ethical judgements between the pressure to cheat …

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 …

Fabrication Of 2- And 3-Dimensional Nanostructures, Hong Jiang, Camelia N. Borca, Bo Xu, Brian W. Robertson

Department of Mechanical and Materials Engineering: Faculty Publications

Amongst tools for fabricating periodic and aperiodic nanostructures and nanodevices, electron beam-induced organometallic chemical vapor deposition (E-OMCVD) offers a highly flexible and controllable one-step deposition process. E-OMCVD enables maskless fabrication of nanoscale research and custom structures that have least dimensions near or below 10 nm–a scale at which other methods prove difficult or costly. Using the focused electron beam in a modified HB501 field-emission scanning transmission electron microscope (STEM), pads and wires with uniform thickness and well-defined shapes have been defined and deposited. Although conditions for fabricating the smallest deposits have not yet been optimized, the edge acuity (sharpness) of …

Study Of Delamination In Acceleration Tested Pv Modules, Florida Solar Energy Center, Neelkanth Dhere

FSEC Energy Research Center®

The average adhesional shear strength at silicon cell/EVA interface in damp-heat, acceleration-tested modules was ~27% of that measured in new modules. The average carbon concentration at the surface of samples extracted from acceleration tested modules was 15 atomic % or ~30% of that measured in new modules. Surface concentrations of sodium on Si-cell samples from the acceleration tested modules ranged from 4.9 to 22.0 atomic %while those of phosphorous ranged from 4.3 to 7.1 at. %. These are very high impurity concentrations. Often small concentrations of phosphorous were detected at the interface between titanium oxide antireflection coating and silicon cell. …

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.

Acuta Enews October 2001, Vol.30, No. 10

ACUTA Newsletters

In This Issue

How Telecom Answered the Call

ACUTA EVENTS

New Member Roundup

DC Update

Board Report

Welcome New Members

Positions Available

How To Interpret Neural Networks In Terms Of Fuzzy Logic?, Sompong Dhompongsa, Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

Neural networks are a very efficient learning tool, e.g., for transforming an experience of an expert human controller into the design of an automatic controller. It is desirable to reformulate the neural network expression for the input-output function in terms most understandable to an expert controller, i.e., by using words from natural language. There are several methodologies for transforming such natural-language knowledge into a precise form; since these methodologies have to take into consideration the uncertainty (fuzziness) of natural language, they are usually called fuzzy logics.

Combining Fuzzy And Probabilistic Knowledge Using Belief Functions, Vladik Kreinovich, Claude Langrand, Hung T. Nguyen

Departmental Technical Reports (CS)

Some knowledge comes in probabilistic terms, some in fuzzy terms. These formalisms are drastically different, so it is difficult to combine the corresponding knowledge. A natural way to combine fuzzy and probabilistic knowledge is to find a formalism which enables us to express both types of knowledge, and then to use a combination rule from this general formalism. In this paper, as such a formalism, we propose to use belief functions. For the case when the universe of discourse is the set of all real numbers, we derive new explicit easy-to-compute analytical formulas for the resulting combination.

A Statistical Analysis For Rule Base Reduction, Vladik Kreinovich, Claude Langrand, Hung T. Nguyen

Departmental Technical Reports (CS)

When we take into account more input variables in a control system, the number of rules grows exponentially. To decrease the number of rules, we propose not to explicitly state the control for every combination of input variables, but to use the "otherwise" clause. In this paper, we provide a simple statistical analysis of the resulting reduction and show, on a case study, that this reduction can indeed be drastic.

Non-Associative Operations, Bernadette Bouchon-Meunier, Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

How is fuzzy logic usually formalized? There are many seemingly reasonable requirements that a logic should satisfy: e.g., since A&B and B&A are the same, the corresponding and-operation should be commutative. Similarly, since A&A means the same as A, we should expect that the and-operation should also satisfy this property, etc. It turns out to be impossible to satisfy all these seemingly natural requirements, so usually, some requirements are picked as absolutely true (like commutativity or associativity), and others are ignored if they contradict to the picked ones. This idea leads to a neat mathematical theory, but the analysis of …

Constrained Fuzzy Arithmetic, Vladik Kreinovich, Mirko Navara, Zdenek Zabokrtsky

Departmental Technical Reports (CS)

No abstract provided.

Introducing Cooperative Learning Through A Faculty Instructional Development Program, Nikos J. Mourtos, Emily L. Allen

Faculty Publications

Cooperative Learning was officially introduced in the College of Engineering at San Jose State University in 1995 with a two-day workshop. The Faculty Instructional Development Program in the college maintains interest in the subjsect and provides support for instructors who use Cooperative Learning, through workshops and informal discussions (Conversations on Teaching). This paper discusses the effectiveness of the program in introducing, promoting, and implementing Cooperative Learning among the faculty and students in the college of engineering. A variety of performance criteria have been used in this assessment, some faculty-centered and some student-centered. The results indicate that although a relatively small …

Ole Miss Engineer 2001

Ole Miss Engineer

No abstract provided.

Santa Clara Magazine, Volume 43 Number 2, Fall 2001, Santa Clara University

Santa Clara Magazine

4 - A GRAND WEEKEND By Adam Breen. At the Grand Anniversary Weekend in June, thousands of alumni, family, and friends gathered to celebrate 150 years of Santa Clara University.

12 - MUSICAL CHAIRS By Jacqueline Tasch. Peter Minowitz loves an audience, whether it is the students in his political science classes or the jazz lovers in local clubs.

14 - ASK THE EXPERTS By Elizabeth Kelley Gillogly '93. Santa Clara University ambassadors help recruit future Broncos.

16 - LESSONS FROM EL SALVADOR By Douglas Sweet. Faculty and students reflect on a spring break "immersion" trip, which for some was …

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.

Characteristics And Sequence Of Phosphoglycolate Phosphatase From A Eukaryotic Green Alga Chlamydomonas Reinhardtii, Tarlan G. Mamedov, Kensaku Suzuki, Kenji Miura, Ken-Ichi Kucho, Hideya Fukuzawa

Papers in Biochemical Engineering

Phosphoglycolate phosphatase (PGPase), a key en¬zyme of photorespiration in photosynthetic organisms, was purified from Chlamydomonas reinhardtii. The en¬zyme was an ~65-kDa homodimer with a pI value of 5.1 composed of ~32-kDa subunits not connected by any S–S bridges. It was also highly specific for phosphoglycolate with a Km value of 140 μM and an optimal pH between 8 and 9. The activity was strongly inhibited by CaCl2, and it recovered competitively following the addition of MgCl2 or EGTA. A mobility shift was observed in SDS-polyacrylamide gel electrophoresis by the addition of CaCl2, indicating that the enzyme binds to Ca2+ . …

Interval Mathematics: Algebraic Aspects, Sompong Dhompongsa, Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

Many application-oriented mathematical models deal with real numbers. In real life, due to the inevitable measurement inaccuracy, we do not know the exact values of the measured quantities, we know, at best, the intervals of possible values. It is thus desirable to analyze how the corresponding mathematical results will look if we replace numbers by intervals.