Digital Commons Network^™

Wide-Bandwidth Multi-Resolutional Analysis Of A Surface-Mounted Pm Synchronous Machine, S. D. Sudhoff, Jerry L. Tichenor, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Advances in power semiconductor devices have led to inverters with unprecedented voltage edge rates. This has decreased inverter switching losses and enabled the use of increasingly higher switching frequencies. However, faster edge rates and higher switching frequencies increase electromagnetic compatibility (EMC) problems, machine insulation stress, bearing currents, and other aspects of system design. Typical computer simulations used to design and evaluate proposed electric drive systems cannot be used to predict these high-frequency effects. A wide-bandwidth multi-resolutional analysis that allows designers to anticipate and quantify high-frequency effects is detailed in this paper. The approach is specifically applied to permanent magnet synchronous …

Imagining The Future: Training Hong Kong Lawyers For The 21 St Century, David N. Smith

Research Collection Yong Pung How School Of Law

Hong Kong must commit itself now to becoming one of the leaders in legal education in Asia and the world. To do so, it must dramatically rethink the structure, process and content of legal education. This will not be easy, but it is essential if Hong Kong is to continue to serve as one of the great centres of finance, trade and technology in the world and if it is to maintain and secure a position of leadership in 21st century China and the Pacific region.

From Austria To The United States And From Evaluating Therapists To Developing Cognitive Resources Theory: An Interview With Fred Fiedler, Robert Hooijberg, Jaepil Choi

Research Collection Lee Kong Chian School Of Business

Interviews Fred Fiedler, researcher on the field of leadership as part of a study that aims to obtain a sense of researchers' personality, research ideas and insights on the state of the field. Personal and professional background; Fiedler's research program; Leadership studies trends; Accomplishments in research; Contributions to the study of leadership.

Optimal Power Allocation In Cdma Forward Link Using Dependency Between Pilot And Traffic Channels, Seung Jong Park, Dongwoo Kim, Chang Yeon Kim

Computer Science Faculty Research & Creative Works

This paper shows a new method for minimizing the transmit power on CDMA forward link channels. Different from previous works, the proposed method uses the dependency that exists between the respective signal qualities of the pilot channel and traffic channels. Since present CDMA forward link exploits coherent demodulation with continuously transmitting pilot signals, the stronger the pilot channel is, the less traffic power may be required while the same transmission quality is maintained. With laboratory tests, the dependency is graphed. And then an optimal pilot signal quality is found, which minimizes the total transmit power. Considering various mobile environments, -10 …

Mining Multiple-Level Association Rules In Large Databases, Jiawei Han, Yongjian Fu

Computer Science Faculty Research & Creative Works

A top-down progressive deepening method is developed for efficient mining of multiple-level association rules from large transaction databases based on the Apriori principle. A group of variant algorithms is proposed based on the ways of sharing intermediate results, with the relative performance tested and analyzed. The enforcement of different interestingness measurements to find more interesting rules, and the relaxation of rule conditions for finding `level-crossing' association rules, are also investigated in the paper. Our study shows that efficient algorithms can be developed from large databases for the discovery of interesting and strong multiple-level association rules.

Investigation Of Inflection Points As Brace Points In Multi-Span Purlin Roof Systems, Michael R. Bryant, Thomas M. Murray

CCFSS Library (1939 - present)

No abstract provided.

Economic Dispatch And Optimal Sizing Of Battery Energy Storage Systems In Utility Load-Leveling Operations, Chin H. Lo, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

Battery energy storage (BES) systems show promise of savings for both the utility and the customer. An algorithm combining multi-pass dynamic programming (MPDP) with a time-shift technique has been developed for two purposes: economic dispatch of BES and finding optimal BES power and energy capacities in a power system. Due to the daily cyclic nature of the load curve, a 168-hour load curve is decomposed into seven 24-hour subsections for easy management. Each subsection is treated independently. Decomposition can save computation time and computer memory. A time-shift technique provides better starting state values and improves the finding process of the …

Multimedia Databases, S. R. Subramanya

Electrical and Computer Engineering Faculty Research & Creative Works

The acquisition, generation, storage and processing of multimedia data in computers and transmission over networks have grown tremendously. Databases have been developed to cope with huge amounts of data in different applications. Multimedia databases (MMDB) are essential for efficient management and effective use of this data. They are however still in their infancy. Most current MMDB system prototypes are closely bound to narrow application areas. Experiences gained from developing and using novel multimedia will help advance the multimedia database technology.

An Accurate Method Of Neglecting Dynamic Saliency Of Synchronous Machines In Power Electronic Based Systems, Steven Pekarek, E. A. Walters

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, motivations for neglecting dynamic saliency in the detailed models of power electronic based systems are presented, A new method of neglecting dynamic saliency is then introduced in which approximate operational impedances are derived from original dynamic salient models. New machine parameters are obtained by fitting to the approximate impedance curves, yielding model parameters in which dynamic saliency is eliminated. An example synchronous machine/converter system is provided that demonstrates the accuracy and increased simulation efficiency resulting from this technique. Therein, errors resulting from neglecting dynamic saliency are reduced from greater than 25% using traditional approximations to less than …

Analysis And Average-Value Modeling Of An Inductorless Synchronous Machine Load Commutated Converter System, J. T. Alt, Scott D. Sudhoff, B. E. Ladd

Electrical and Computer Engineering Faculty Research & Creative Works

Synchronous machine fed load-commutated converters (SMLCCs) are commonly used for dc power sources in marine and aircraft power systems. The focus of this paper is to set forth a model for SMLCCs for use in transient stability studies involving these systems. Although there has been considerable work in this area, much of this work has assumed the existence of a dc link inductor whereupon the dc link current is approximately constant. In practice, this filter is often eliminated, whereupon previous models are no longer valid. A new average-value model is set forth for SMLCCs in which there is no dc …

An Efficient And Accurate Method Of Representing Magnetic Saturation In Physical-Variable Models Of Synchronous Machines, Steven Pekarek, E. A. Walters, B. T. Kuhn

Electrical and Computer Engineering Faculty Research & Creative Works

When analyzing machine/converter systems it is convenient to represent the stator variables in physical (abc) form. It has recently been shown that a physical-variable voltage-behind-reactance form of the synchronous machine model can be derived which is numerically more efficient than existing physical-variable models. In this research, a new voltage-behind-reactance model is derived which incorporates the effects of magnetic saturation. This model is shown to have the same numerical efficiency of the unsaturated model and is readily implemented in either circuit-based or differential-equation based simulation languages. An example system is provided which demonstrates the accuracy and efficiency of this model for …

An Environmental History Of The 19th Century Marquette Iron Range, Doug Ottke

Theses and Dissertations

The history of the Marquette Iron Range in the upper peninsula of Michigan is integrally linked to the environment. The natural features of the Marquette Range defined the mode of production on the Range, and conversely, as human systems became more adept in these modes of production they became the most important modifiers of the natural systems.

Settlement on the Marquette Iron Range was closely related to two factors of natural environment: the iron ore formations and the hardwood forest. The distribution of three iron ore formations—principally the Negaunee, but also the Bijiki and other Iron- formations within the Michigamme …

Dielectric Plug-Loaded Two-Port Transmission Line Measurement Technique For Dielectric Property Characterization Of Granular And Liquid Materials, K. Mubarak, R. Zoughi, Aaron D. Benally, Karl Joseph Bois, Larry F. Handjojo

Electrical and Computer Engineering Faculty Research & Creative Works

There are numerous dielectric property characterization techniques available in the microwave regime each with its own uniqueness, advantages and disadvantages. The two-port completely-filled waveguide (transmission line) technique is a robust measurement approach which is well suited for solid dielectric materials. In this case, the dielectric material can be relatively easily machined to fit inside the waveguide and the subsequent measurement of the scattering parameters of this two-port device renders the dielectric properties of the material filling the waveguide. However, this technique is not well suited for measuring the dielectric properties of granular and liquid materials. These materials are used in …

Extension's Portfolio For The 21st Century: A Place For One-On-One Consultations, Peggy Petrzelka, Steve Padgitt, Wendy Wintersteen

Journal of Extension

Revisits the individual consultations that provided the base from which the Cooperative Extension Service grew. Using data gathered from clients' and Extension staff evaluations of one-on-one activities, our findings show these consultations have an economic and educational value for clients. The consultations benefit field specialists as well, augmenting their need assessments by providing information from in the field, providing opportunities for on-going research, and building credibility. It is maintained that continuing (or re-implementing) these consultations as part of Extension's portfolio for the 21st Century has mutual benefit, both to the client and to Extension.

The Relationship Between Secondary Teachers' Perceptions Of Empowerment And A Principal's Leadership Style, George W. Walker

Electronic Theses and Dissertations

This study was designed to investigate the relationship between teachers' perceptions of empowerment and their impressions of their principal's leadership style within Bolman and Deal's four organizational frames, selected teacher demographics, and school size. The study used the survey method of data collection. Completed School Participant Empowerment Scales, Leadership Orientations Other Scales, and demographics forms were received from 315 (90%) of the teachers surveyed. The criterion variable, or dependent variable, was the teachers' scores on the School Participant Empowerment Scale. Teachers' scores on the Leadership Orientations Other Scale, teacher demographics (age, educational level, and teaching experience), and school size were …

Statistical Controller Design For The Linear Benchmark Problem, Chaouki T. Abdallah, V. Koltchinskii, M. Ariola, Peter Dorato

Electrical & Computer Engineering Faculty Publications

In this paper some fixed-order controllers are designed via statistical methods for the benchmark problem originally presented at the 1990 American Control Conference. Based on some recent results by the authors, it is shown that the statistical approach is a valid method to design robust controllers. Two different controllers are proposed and their performance are compared with controllers with the same structure, designed using different techniques.

Predicting Post-Disaster Adjustment After The Red River Flood: An Analysis Of Resource Loss And Pre-Flood Preventative Behaviors, Holly J. Hegstad

Theses and Dissertations

The Conservation of Resources theory postulates that individuals will act to obtain, retain, or protect those resources that are of value to them (Hobfall, 1989). Natural disasters often result in depletion of resources, the extent of which has been found to be a robust predictor of post-disaster adjustment (Freedy, Hobfall, & Ribbe, 1994; Freedy, Shaw, Jarrel, & Masters, 1992; Norris & Uhl, 1993; Smith & Freedy, 1994). Three-hundred-four victims (131 males, 171 females) of the 1997 flood of the Red River returned surveys assessing their levels of preparation, resource losses, and psychopathology 12 to 16 months after the flood. It …

The Inevitable Infidelities Of Constitutional Translation: The Case Of The New Deal, John O. Mcginnis

Articles

No abstract provided.

Implementation Of Speech Recognition Software For Text Processing: An Exploratory Analysis, Sean P. Abell

Theses and Dissertations

The rationale behind implementing new information technologies is often to gain productivity improvements associated with the substitution of machinery for labor. However, the literature shows little direct evidence of a positive relationship between information technology investment and subsequent productivity benefits. This thesis reports on the examination into the productivity implications of implementing speech recognition software in a text processing environment. More specifically, research was conducted to compare text processing speeds and error rates using speech recognition software versus the keyboard and mouse. Of interest was the time required to input and proofread text processing tasks as well as the number …

A Numerical Simulation Of A Carbon Black Suspension Cell Via A Time-Reversed, Double Layer Compute Algorithm, Gregg T. Anderson

Theses and Dissertations

A numerical simulation of a carbon black suspension cell is explored which models a laser-induced plasma within a liquid ethanol medium of approximately 1 mm thickness. The simulation model assumes a laser pulse with a pulse width of approximately 9 nsecs propagating in the left-to-right direction striking the front surface of the medium and focusing to a spot within the liquid volume. When the energy density within a given irradiated volume is sufficiently high, it ignites the carbon particles and generates a large number of free electrons, i.e., a plasma. The plasma couples with the in-coming laser energy on a …

Towards A Game Theory Model Of Information Warfare, David A. Burke

Theses and Dissertations

The repeated game of incomplete information model, a subclass of game theory models, was modified to include aspects of information warfare. The repeated game of incomplete information model was first developed to analyze nuclear weapons disarmament negotiations. The central role of information in this model suggested its applicability to IW, which focuses on the defense and acquisition of information. A randomized experimental design was utilized to determine how people behave in a laboratory IW setting and to test the IW game model's basic predictions. The impact of experience and learning on IW performance was also assessed during the experiment. IW …

Network Security Versus Network Connectivity: A Framework For Addressing The Issues Facing The Air Force Medical Community, Franklin E. Cunningham Jr.

Theses and Dissertations

The Air Force has instituted Barrier Reef to protect its networks. The Air Force medical community operates network connections that are incompatible with Barrier Reef. To overcome this problem, OASD(HA) directed the Tri-Service Management Program Office (TIMPO) to develop an architecture that protects all military health systems and allows them to link with all three services and outside partners. This research studied the underlying networking issues and formed a framework based on data from network experts from the Air Force's medical centers and their base network organizations. The findings were compared TIMPO and a composite framework was developed that more …

Power, Performance, And Perception (P3): Integrating Usability Metrics And Technology Acceptance Determinants To Validate A New Model For Predicting System Usage, Alan P. Fiorello

Theses and Dissertations

Currently, there are two distinct approaches to assist information technology managers in the successful implementation of office automation software. The first approach resides within the field of usability engineering, while the second approach is derived from the discipline of management information systems (MIS). However, neither approach has successfully produced conclusive evidence that explains what characteristics facilitate system use as well as influence user acceptance of the system. This study reports on the validity of a new model, entitled the Power, Performance, Perception (P3) model, that links the constructs of usability engineering to user acceptance. Additionally, speech recognition software (SRS) was …

Evaporation Of Jet Fuels, Charles Eric Hack

Theses and Dissertations

Determining the fate and transport of JP-8 jet fuel is a complex and important problem. As part of the startup procedures for jet engines, fuel is passed through aircraft engines before combustion is initiated. Because of the extremely low temperatures at northern tier Air Force bases, the unburned fuel does not evaporate readily and may come into contact with ground crew. To determine the amount and duration of contaminant contact, the evaporation of the emitted fuel must be modeled. The amount and composition of the fuel upon reaching the ground crew may be determined by droplet evaporation models that have …

Effects Of Foreign Object Damage From Small Hard Particles On The High-Cycle Fatigue Life Of Ti-6a1-4v, Joseph L. Hamrick Ii

Theses and Dissertations

Thin rectangular samples of Ti-6Al-4V were damaged by four methods to represent foreign object damage found in turbine engine blades: 1) impact with 2 mm and 5 mm diameter glass spheres at 305 m/s, 2) impact with 2 mm and 4 mm diameter steel spheres at 305 m/s, 3) quasi-static displacement controlled indentation using steel chisels with 1 mm, 2 mm and 5 mm diameter tips and 4) shearing notches with a 2 mm diameter chisel point under a quasi-static loading condition. Finite element analysis was used to study the relationship between the stress state created by the plastic damage …

Impact Of Actual Facilitator Alignment, Co-Location, And Video Intervention On The Efficacy Of Distributed Group Support Systems, Brian J. Heberlie, Mary O. Tolbert

Theses and Dissertations

The growth of distributed group support systems (GSS) suggests that organizations will continue to bring dispersed groups of people together to make decisions over computer networks. In many instances those groups are temporarily assembled to address a task and then summarily disbanded never to work together again. In order for users to effectively use the GSS issues of trust and control need to be addressed within the GSS design. Users have perceptions about the fairness of structural and social determinants of the GSS design. These perceptions influence both the decision making process and process outcomes. This article shows the negative …

Information System Incidents: The Development Of A Damage Assessment Model, Mark D. Horony

Theses and Dissertations

Information system (IS) incidents are on the rise. With low manning and undertrained information security specialists it is difficult for organizations to stop IS incidents from occurring. Once an incident has occurred it is the IS manager's responsibility to ensure that a full and accurate damage assessment has been accomplished. However, most IS managers lack the necessary tools to assess the damage from an incident. This exploratory thesis developed an IS incident damage assessment model (DAM) that can be part of the IS manager's tool kit. During the development of the model, it became apparent that the model was supported …

Why Didn’T You Tell Me?: Toward Building A Model Of Why Information Is Not Shared Well In Organizations, Robert C. Kitchen

Theses and Dissertations

The effective use of information in an organization is vital to its success. One of the biggest investments being made today by companies is in their information infrastructures. However, with all of the resources being dedicated to improving information flows, evidence shows that organizations still do not share information as widely as they could or should be. Many studies have been conducted to learn the reasons why people in organizations do not share information as well as would be good. However, no study was found that reported the relative frequency of reported reasons for not sharing information. This paper gathers …

An Analysis Of Training Adequacy And Additional Training Requirements As Perceived By Communications And Information Officers, Rex W. Little

Theses and Dissertations

This study explores requirements for additional training Communications and Information officers. This research also looks at the best time to provide training/education in the identified training deficient areas. Training areas and categories were established by two previous theses and were modified by a group of field experts for this research. The following questions were posed in an effort to obtain the perception of officers in the field: (1) What training areas do Communications and information officers feel are deficient? (2) At what point during a Communications and Information officer's career would it be most appropriate to receive training in necessary …

Application Of The Interaction Picture To Reactive Scattering In One Dimension, Michael J. Maclachlan

Theses and Dissertations

The interaction picture is used together with the channel-packet method in a new time-dependent approach to compute reactive scattering matrix elements. The channelpacket method enables the use of the interaction picture for computing reactive S-matrix elements by splitting the computational effort into two parts. First, asymptotic reactant and product wavepackets are individually propagated into the interaction region of the potential to form Moller states. The interaction picture, in contrast to the usual Schrödinger picture of quantum mechanics, is so constructed that a wavefunction that experiences no change in potential (that is, a free-particle wavefunction) remains always fixed, with no translation …