Engineering Commons^™

Usability Inspection Methods After 15 Years Of Research And Practice, David G. Novick, Tasha Hollingsed

Departmental Papers (CS)

Usability inspection methods, such as heuristic evaluation, the cognitive walkthrough, formal usability inspections, and the pluralistic usability walkthrough, were introduced fifteen years ago. Since then, these methods, analyses of their comparative effectiveness, and their use have evolved in different ways. In this paper, we track the fortunes of the methods and analyses, looking at which led to use and to further research, and which led to relative methodological dead ends. Heuristic evaluation and the cognitive walkthrough appear to be the most actively used and researched techniques. The pluralistic walkthrough remains a recognized technique, although not the subject of significant further …

Toward A More Accurate View Of When And How People Seek Help With Computer Applications, David G. Novick, Edith Elizalde, Nathaniel Bean

Departmental Papers (CS)

Based on 40 interviews and 11 on-site workplace observations of people using computer applications at work, we confirm that use of printed and on-line help is very low and find that providing greater detail of categories solution methods can present a more realistic picture of users’ behaviors. Observed study participants encountered a usability problem on average about once every 75 minutes and typically spent about a minute looking for a solution. Participants consumed much more time when they were unaware of a direct way of doing something and instead used less effective methods. Comparison of results from different data-collection methods …

Hybrid Of Scattering Matrix Method And Integral Equation Used For Co-Simulation Of Power Integrity And Emi In Electronic Package With Large Number Of P/G Vias, Zaw Zaw Oo, En Xiao Liu, Xing Chang Wei, Mark Tan Yew Choon, Er Ping Li, Yaojiang Zhang, Le Wei Li

Electrical and Computer Engineering Faculty Research & Creative Works

The paper presents the development of a coupled scattering matrix method (SMM) with integral equation method for analyzing the power integrity (PI) of multilayered package structure with large number of power/grounds vias. Analysis of the entire signal traces and the associated vias, connected between the power and ground, (named as P/G vias) is treated as analyzing the coupling between the external signal traces and the inside vertical vias, and analyzing the scattering effects between the vertical vias. a pair of the layered power/ground planes is considered as the parallel plate waveguide structure. the scattering matrix method for the parallel-plate waveguide …

Ceas E-News 10.16.2007, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Six honored by CEAS Dean for outstanding work

Use Of Ellipsometry And Surface Plasmon Resonance In Monitoring Thin Film Deposition Or Removal From A Substrate Surface, John A. Woollam, Blaine D. Johs, Thomas E. Tiwald, Martin M. Liphardt, James D. Welch

Department of Electrical and Computer Engineering: Faculty Publications

Improved methodology for monitoring deposition or removal of material to or from a process and/or Wittness substrate Which demonstrates a negative e1 at some Wave length. The method involves detection of changes in P-polarized electromagnetism ellipsometric DELTA at SPR Resonance Angle-of-lncidence (A01) to monitor deposition of and/or removal of minute amounts of materials onto, or from, said process and/or Witness substrate. The methodology can optionally monitor ellipsometric PS1, and involves simultaneously or sequentially applying non-P-polarized electromagnetism at the same angle of incidence, or electromagnetic radiation of any polarization at a different angle-of-incidence and Wavelength to the process or Witt ness …

Synthetic Fuel And Methods For Producing Synthetic Fuel, Darrell Neal Taulbee

Center for Applied Energy Research Faculty Patents

The present invention provides synthetic fuels, additives for use in preparing synthetic fuels and methods for producing synthetic fuel. The synthetic fuels include low levels of a chemical change additive selected from the group consisting of alkaline earth oxides and hydroxides and mixtures thereof. In one embodiment, the synthetic fuel further includes low levels of a second chemical change additive, which is a petroleum hydrocarbon material.

Nanoindentation Of The A And C Domains In A Tetragonal Batio3 Single Crystal, Young-Bae Park, Matthew J. Dicken, Zhi-Hui Xu, Xiaodong Li

Faculty Publications

Nanoindentation in conjunction with piezoresponse force microscopy was used to study domain switching and to measure the mechanical properties of individual ferroelectric domains in a tetragonal BaTiO₃ single crystal. It was found that nanoindentation has induced local domain switching; the a and c domains of BaTiO₃ have different elastic moduli but similar hardness.Nanoindentationmodulus mapping on the a and c domains further confirmed such difference in elasticity. Finite element modeling was used to simulate the von Mises stress and plastic strain profiles of the indentations on both a and c domains, which introduces a much higher stress level than …

Airway Strain During Mechanical Ventilation In An Intact Animal Model, Scott W. Sinclair, Robert C. Molthen, Steven Thomas Haworth, Christopher A. Dawson, Christopher M. Waters

Biomedical Engineering Faculty Research and Publications

Rationale: Mechanical ventilation with large tidal volumes causes ventilator-induced lung injury in animal models. Little direct evidence exists regarding the deformation of airways in vivo during mechanical ventilation, or in the presence of positive end-expiratory pressure (PEEP).

Objectives: To measure airway strain and to estimate airway wall tension during mechanical ventilation in an intact animal model.

Methods: Sprague-Dawley rats were anesthetized and mechanically ventilated with tidal volumes of 6, 12, and 25 cm³/kg with and without 10–cm H₂O PEEP. Real-time tantalum bronchograms were obtained for each condition, using microfocal X-ray imaging. Images were …

Cognitive Radio: Fundamentals And Opportunities., Robert H. Morelos-Zaragoza

Faculty Publications

This talk is aimed at MSEE students in San Jose State University. It provides an overview of cognitive radio concepts and technologies. A MATLAB Simulink of demonstration of digital channel selection using a low IF radio architecture is presented. Technical challenges that remain to be solved in this area are identified.

Time Dependent Discrete Ordinates Neutron Transport Using Distribution Iteration In Xyz Geometry, James R. Dishaw

Theses and Dissertations

The DI algorithm is an alternative to source iteration that, in our testing, does not require an accelerator. I developed a formal verification plan and executed it to verify the results produced by my code that implemented DI with the above features. A new, matrix albedo, boundary condition treatment was developed and implemented so that infinite-medium benchmarks could be included in the verification test suite. The DI algorithm was modified for parallel efficiency and the prior instability of the refinement sweep was corrected. The testing revealed that DI performed as well or faster than source iteration with DSA and that …

Evaluation Of Irrigation Strategies With The Dssat Cropping System Model, Derek M. Heeren, Hal D. Warner, Todd P. Trooien

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Water is becoming an increasingly valuable commodity with shortages and water rationing more commonplace. Since irrigation is the largest consumptive use of water in South Dakota, accounting for over 70% of the water withdrawals, irrigation water management is critical to make the best use of the water available. This project uses the CERES-Maize cropping system model (available in DSSAT v4) to study the impact of various irrigation management strategies on corn production. SDSU management software developed by Oswald (2006) is used to simulate a center pivot for specific locations and years. Weather data from several sites in the Great Plains …

Integrated Piezoresistive Sensing For Feedback Control Of Compliant Mems, Robert K. Messenger

Theses and Dissertations

Feedback control of MEMS devices has the potential to significantly improve device performance and reliability. One of the main obstacles to its broader use is the small number of on-chip sensing options available to MEMS designers. A method of using integrated piezoresistive sensing is proposed and demonstrated as another option. Integrated piezoresistive sensing utilizes the inherent piezoresistive property of polycrystalline silicon from which many MEMS devices are fabricated. As compliant MEMS structures flex to perform their functions, their resistance changes. That resistance change can be used to transduce the structures' deflection into an electrical signal. This dissertation addresses three topics …

Work In Progress - Undergraduate Research In Power Electronics - The Super Barrier Rectifier Diode Project, Taufik

Electrical Engineering

This paper presents an undergraduate student research project which involved a new power diode called the super barrier rectifier (SBR) diode. Several projects incorporating SBR diodes in dc-dc converters performed by undergraduate students will be described. Challenges in conducting these projects along with results will also be discussed.

Optimization Of Gallium Nitride-Based Laser Diode Through Transverse Modes Analysis, Xiaomin Jin, Bei Zhang, Liang Chen, Tao Dai, Guoyi Zhang

Electrical Engineering

We investigate the transverse mode pattern in GaN quantum-well (QW) laser diode (LD) by numerical calculation. We optimize the current GaN LD structure by varying the n-GaN layer thickness. The n-type GaN layer is an important factor to determine the optical mode. Finally, we discuss the lasing performance of the GaN LD based on the transverse optical modes.

Work In Progress - Improving Learning Using Industry Supported Project In Power Electronics Course, Taufik

Electrical Engineering

This paper presents an approach that has recently been developed and initiated in teaching undergraduate power electronics course to enhance the learning by exposing students to the most recent state of power electronics technology and applications. The approach involves a hardware project that is supported by industry that is at the forefront of power electronics technology, applications, and devices. The hardware project will be detailed in this paper along with the grading and assessment methods. Difficulties encountered will also be presented.

Work-In-Progress - Self-Directed Learning And Motivation In A Project-Based Learning Environment, Trevor S. Harding, Linda Vanasupa, Richard N. Savage, Jonathan D. Stolk

Materials Engineering

Self-directed learning is a key competency in life-long learning, an outcome often cited for engineering education, and is dependent on students' motivation, meta-cognition, and self-regulation with regards to a learning task. Few studies have addressed the aspects of engineering learning environments that promote the development of self-directed learning abilities. The goal of this study was to identify relationships between students' perceptions of their self-directed learning ability and their learning motivation within a project-based learning environment. Junior engineering students in a test cohort with heavy emphasis on project-based learning completed surveys on self-directed learning aptitude and learning motivation. Responses were compared …

Effect Of Surface Roughness On Rate-Dependent Slip In Simple Fluids, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

Molecular dynamics simulations are used to investigate the influence of molecular-scale surface roughness on the slip behavior in thin liquid films. The slip length increases almost linearly with the shear rate for atomically smooth rigid walls and incommensurate structures of the liquid/solid interface. The thermal fluctuations of the wall atoms lead to an effective surface roughness, which makes the slip length weakly dependent on the shear rate. With increasing the elastic stiffness of the wall, the surface roughness smoothes out and the strong rate dependence is restored again. Both periodically and randomly corrugated rigid surfaces reduce the slip length and …

Global Positioning System Systems Engineering Case Study, Air Force Center For Systems Engineering, Patrick J. O'Brien, John M. Griffin

AFIT Documents

No abstract provided.

Sub-Surface Corrosion Research On Rock Bolt System, Perforated Ss Sheets And Steel Sets For The Yucca Mountain Repository — Quarterly Technical Report No. 13, Dhanesh Chandra, Jaak J.K. Daemen

Publications (YM)

This report shows the work done for this period in accordance to cooperative agreement of University of Nevada system for the Task 019 “Subsurface Corrosion Research on Rock Bolt System, Perforated SS Sheets and Steel Sets for the Yucca Mountain Repository”, the overall objective of which is to conduct corrosion research and predict the durability of rock-bolts and other underground metallic roof supports. We are performing oxidation tests using Thermogravimetric Analyzer (TGA), and Potentiodynamic and immersion tests to determine the corrosion rates of rock bolts. In this quarter: Potentiodynamic tests were performed to determine corrosion rates (CR) of 4340 Steel …

A Two-Phase Approach To Interactivity Enhancement For Large-Scale Distributed Virtual Environments, Nguyen Binh Duong Ta, Suiping Zhou

Research Collection School Of Computing and Information Systems

Distributed virtual environments (DVEs) are distributed systems that allow multiple geographically distributed clients (users) to interact simultaneously in a computer-generated, shared virtual world. Applications of DVEs can be seen in many areas nowadays, such as online games, military simulations, collaborative designs, etc. To support large-scale DVEs with real-time interactions among thousands or even more distributed clients, a geographically distributed server architecture (GDSA) is generally needed, and the virtual world can be partitioned into many distinct zones to distribute the load among the servers. Due to the geographic distributions of clients and servers in such architectures, it is essential to efficiently …

Control System For Suppression Of Boom Or Arm Oscillation, Kee Moon

Michigan Tech Patents

A control for a working apparatus having a boom arm. The apparatus includes a controller operable to receive signals from at least one pressure sensor. The at least one pressure sensor detects pressure of hydraulic fluid in at least one chamber of a control valve. The controller compares the signals from the at least one pressure sensor to parameters generated by testing the working apparatus. The controller predicts boom arm oscillations based on the comparison of the signals with the parameters, and generates a control signal in response to predicting the boom arm oscillations.

Ceas E-News 10.09.2007, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Area middle-schoolers explore paper making and printing in CEAS Workshop

Implementation Of Uncertainty Propagation In Triton/Keno: To Support The Global Nuclear Energy Partnership, Charlotta Sanders, Denis Beller

Reactor Campaign (TRP)

Monte Carlo methods are beginning to be used for three-dimensional fuel depletion analyses to compute various quantities of interest, including isotopic compositions of used fuel.1 The TRITON control module, available in the SCALE 5.1 code system, can perform three dimensional (3-D) depletion calculations using either the KENO V.a or KENO-VI Monte Carlo transport codes, as well as the two-dimensional (2- D) NEWT discrete ordinates code. For typical reactor systems, the neutron flux is not spatially uniform. For Monte Carlo simulations, this results in non-uniform statistical uncertainties in the computed reaction rates. For spatial regions where the flux is low, e.g., …

Monaco/Mavric Evaluation For Facility Shielding And Dose Rate Analysis: To Support The Global Nuclear Energy Partnership, Charlotta Sanders, Denis Beller

Reactor Campaign (TRP)

Monte Carlo methods are used to compute fluxes or dose rates over large areas using mesh tallies. For problems that demand that the uncertainty in each mesh cell be less than some set maximum, computation time is controlled by the cell with the largest uncertainty. This issue becomes quite troublesome in deep-penetration problems, and advanced variance reduction techniques are required to obtain reasonable uncertainties over large areas.

In this project the MAVRIC sequence will be evaluated along with the Monte Carlo engine Monaco to investigate its effectiveness and usefulness in facility shielding and dose rate analyses. A previously MCNP-evaluated cask …

A Generalized Two-Dimensional Model To Reconstruct The Impact Phase In Automobile Collisions, Regis Agenor David

Theses and Dissertations

Automobile accident reconstruction has been facilitated by the development of computer based modules to allow evaluation of evidence gathered at the accident scenes. Although the computer modules are based in fundamental physical laws, an understanding of these laws by the user is required for proper application of the computer model in a given accident scenario. Vehicle collision analysis techniques generally separate the collision into three phases: pre-impact, impact, and post impact. The intent of the research is to provide a generalized model to reconstruct two dimensional impact problems in the area of accident reconstruction. There are currently two modeling techniques …

An Experimental Technique For The Evaluation Of Strain Dependent Material Properties Of Hard Coatings, Shad A. Reed, Anthony N. Palazotto, William P. Baker

Faculty Publications

A novel vibration experiment consisting of a free-free boundary condition, an electromagnetic excitation source, a vacuum chamber, and a laser vibrometer based surface measurement system has been developed that permits high levels of excitation on highly damped specimens with a minimal amount of unwanted systematic error. While some of the aspects of this experiment are not unique, when combined with a processing technique that accounts for the nonlinearities present in the system, this experiment permits, accurate measurement of strain dependent stiffness and damping properties of hard coatings at high strain levels. This procedure has been demonstrated using a titanium beam …

Optimal Control Of Class Of Non-Linear Plants Using Artificial Immune Systems: Application Of The Clonal Selection Algorithm, S. A. Panimadai Ramaswamy, Ganesh K. Venayagamoorthy, S. N. Balakrishnan

Electrical and Computer Engineering Faculty Research & Creative Works

The function of natural immune system is to protect the living organisms against invaders/pathogens. Artificial Immune System (AIS) is a computational intelligence paradigm inspired by the natural immune system. Diverse engineering problems have been solved in the recent past using AIS. Clonal selection is one of the few algorithms that belong to the family of AIS techniques. Clonal selection algorithm is the computational implementation of the clonal selection principle. The process of affinity maturation of the immune system is explicitly incorporated in this algorithm. This paper presents the application of AIS for the optimal control of a class of non-linear …

Non-Ossicular Signal Transmission In Human Middle Ears: Experimental Assessment Of The "Acoustic Route" With Perforated Tympanic Membranes, Susan E. Voss, John J. Rosowski, Saumil N. Merchant, William T. Peake

Engineering: Faculty Publications

Direct acoustic stimulation of the cochlea by the sound-pressure difference between the oval and round windows (called the "acoustic route") has been thought to contribute to hearing in some pathological conditions, along with the normally dominant "ossicular route." To determine the efficacy of this acoustic route and its constituent mechanisms in human ears, sound pressures were measured at three locations in cadaveric temporal bones [with intact and perforated tympanic membranes (TMs)]: (1) in the external ear canal lateral to the TM, PTM; (2) in the tympanic cavity lateral to the oval window, POW; and (3) near the round window, PRW. …

Ceas E-News 10.02.2007, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Civil engineering student to compete in Miss Michigan pageant

Design Of A Logic Element For Implementing An Asynchronous Fpga, Scott C. Smith

Electrical and Computer Engineering Faculty Research & Creative Works

A reconfigurable logic element (LE) is developed for use in constructing a NULL Convention Logic (NCL) FPGA. It can be configured as any of the 27 fundamental NCL gates, including resettable and inverting variations, and can utilize embedded registration for gates with three or fewer inputs. the developed LE is compared with a previous NCL LE, showing that the one developed herein yields a more area efficient NCL circuit implementation. the NCL FPGA logic element is simulated at the transistor level using the 1.8V, 180nm TSMC CMOS process. Copyright 2007 ACM.