Digital Commons Network^™

Reflection And Refraction Of Light From Nonlinear Boundaries, Mohammad Azadeh

Dissertations and Theses

This thesis deals with the topic of reflection and refraction of light from the boundary of nonlinear materials in general, and saturating amplifiers in particular. We first study some of the basic properties of the light waves in nonlinear materials. We then develop a general formalism to model the reflection and refraction of light with an arbitrary angle of incidence from the boundary of a nonlinear medium. This general formalism is then applied to the case of reflection and refraction from the boundary of linear dielectrics. It will be shown that in this limit, it reduces to the well known …

Generalized Reverse Theorems For Multipass Applications In Matrix Optics, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

The reverse theorem that governs backward propagation through optical systems represented by transfer matrices is examined for various matrix theories. We extend several reverse theorems to allow for optical systems represented by matrices that may or may not be unimodular and that may be 2 × 2 or take on an augmented 3 × 3 form. As an example, we use the 3 × 3 form of the reverse theorem to study a laser with intracavity misaligned optics. It is shown that, by tilting one of the laser's mirrors, we can align the laser output arbitrarily, and the mirror tilt …

Particle Trapping In Estuarine Tidal Flows, David A. Jay, Jeffery D. Musiak

Civil and Environmental Engineering Faculty Publications and Presentations

Particle trapping in estuarine turbidity maxima (ETM) is caused primarily by convergent mean and/or tidal fluxes of sediment. The result is an approximately bell-shaped along-channel distribution of vertically integrated, tidal cycle mean suspended sediment concentration. Observations from the Columbia River estuary suggest that (1) strong two-layer or internal along-channel residual and overtide flows are generated by time-varying stratification and (2) correlations between the near-bed velocity and the suspended sediment fields at these frequencies are important in landward transport of sediment. A new spatially and temporally integrated form of the sediment conservation equation has been derived to analyze this trapping process. …

An Examination Of The Occurrences Of Metaphor In Introductory Engineering Textbooks, Hartwell S. Francis

Dissertations and Theses

The aim of this study is to identify the use of metaphor in university-level introductory engineering textbooks. Engineering is an important field of study for foreign students in the United States. In order to determine the linguistic and cultural problems foreign students of this field may have, two introductory engineering textbooks are examined for occurrences of metaphors.

Two corpora of 20,000 words each drawn from introductory textbooks used at two four-year, public universities are examined for occurrences of metaphor. A combined semantic and pragmatic test for metaphor is applied to each word used in the corpora to determine if the …

Circuit Modeling Of Switched Linear Networks, Fardin Ansari

Dissertations and Theses

The use of switched linear networks is prevalent in power processing systems such as dc-to-dc power converters. These converters provide regulated dc output power and are widely used in the power supplies for computers and peripherals. As with most systems where high performance is a criterion, the power converter is usually enclosed in a feedback loop. Feedback design usually entails the use of small signal (linear) models with linear feedback design techniques. There exists a large number of small signal models, but most of them are ad hoc. A describing function approach has previously been presented which determines the exact …

Meeting Notes 1994-09-08 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

Portland State Magazine, Portland State University. Office Of University Communications

Portland State Magazine

PSU’s alumni magazine, published 2-3 times a year. In this issue: Jack Dunn has been a while of motion, a non-stop talker and a winning baseball coach for the past 20 years; science, social science and liberal arts general requirements are gone and all eyes are on Portland State; what happens to the children when there is no home to go home to?; Oregonians thought they were safe from radon, but a new study has uncovered local hot spots; and more.

Objects To The Rescue! Or Httpd: The Next Generation Operating System, Andrew P. Black, Jonathan Walpole

Computer Science Faculty Publications and Presentations

This position paper suggests that object-oriented operating systems may provide the means to meet the ever-growing demands of applications. As an example of a successful OOOS, we cite the http daemon. To support the contention that httpd is in fact an operating system, we observe that it implements uniform naming, persistent objects and an invocation meta-protocol, specifies and implements some useful objects, and provides a framework for extensibility.We also believe that the modularity that is characteristic of OO systems should provide a performance benefit rather than a penalty. Our ongoing work in the Synthetix project at OGI is exploring the …

Meeting Notes 1994-08-11 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

Meeting Notes 1994-07-14 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

City Club Of Portland Report On Homosexuality In Oregon, City Club Of Portland (Portland, Or.)

City Club of Portland

No abstract provided.

Rain, Eco-Net

RAIN: Journal of Appropriate Technology

Volume 14, Number 4

Inside: Car Co-ops; Grassroots Bolivia; Berlin's Eco-Villages; Christopher Alexander's Latest

RAIN began in October 1974 as a publication of ECO-NET, an environmental education network funded by the Hill Foundation and an Environmental Education grant. Its office was based in the Environmental Education Center at Portland State University. With a focus on the Pacific Northwest, particularly Oregon, RAIN originally described itself as a “bulletin board” with an “emphasis on environmental/energy related and communications kinds of information” and interested in “the evolutionary possibilities of inter-disciplinary connections.”

1994 Commencement Program, A. Gary Ames

Commencement Archives 1990-99

The program for the Portland State University Spring Commencement ceremony on June 11, 1994.

A. Gary Ames, communications executive and Portland State alumnus, received an honorary degree and delivered the commencement address.

The Design, Realization And Testing Of The Ilu Of The Ccm2 Using Fpga Technology, David W. Foote

Dissertations and Theses

Most existing computers today are built upon a subset of the arithmetic system which is based upon the foundation of set theory. All formal systems can be expressed in terms of arithmetic and logic on current arithmetic computers through an appropriate model, then work with the model using software manipulation. However, severe speed degradation is the price one must pay for using a software-based approach, making several high-level formal systems impractical.

To improve the speed at which computers can implement these high-level systems, one must either design special hardware, implementing specific operations much like math and image processing coprocessors, or …

Meeting Notes 1994-06-09 [Part B] , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

Meeting Notes 1994-06-09 [Part A] , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

Meeting Notes 1994-05-12 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

The Evaluation Of Device Model Dependence In The Design Of A High-Frequency, Analog, Cmos Transconductance-C Filter, Susan Rose Brotman

Dissertations and Theses

It is important to have the ability to predict the effects of device model variation when designing integrated transconductance-C type active filters. Applying these filters to integrated circuit design has become increasingly popular due to its ease of implementation in monolithic form. With the introduction of fully automated design tools, predictable behavior of high-level variables becomes still more important. The purpose of this study is to evaluate the process parameter spread of analog device models to determine the effect on the design parameters of an active filter. This information's significant contribution directly effects the feasibility and realization of automating analog …

Planning For Academic Success: Survey Of University Professors' Assessments Of Non-Native Students' Language Skill Needs, Carol Bondurant Sloan

Dissertations and Theses

The purpose of this study is to examine which language skills university professors believe are most essential for academic success in Portland State University classes. The study can shed light on a question for future research: Do current academic ESL classes at Portland State University teach the necessary skills to help international students maximize their second-language learning potential in university-level courses. Enrollment statistics for 1993 I 94 show 53 percent of the 815 international students declared majors in two programs: the school of Business Administration and the school of Engineering and Applied Science. This study asked 31 instructors from business …

High-Frequency Analog Voltage Converter Design, Ping Xu

Dissertations and Theses

For many high-speed, high-performance circuits, purely differential inputs are needed. This project focuses on building high-speed voltage converters which can transfer a single-ended signal to a purely differential signal, or a differential input signal to a single-ended signal.

Operational transconductance amplifier (OTAs) techniques are widely used in high-speed continuous-time integrated analog signal processing (ASP) circuits because resistors, inductors, integrators, buffers, multipliers and filters can be built by OTAs and capacitors. Taking advantage of OTAs, very-high-speed voltage converters are designed in CMOS technology. These converters can work in a frequency range from DC (0Hz) up to 100MHz and higher, and keep …

A User-Level Process Package For Concurrent Computing, Ravi Konuru, Steve Otto, Jonathan Walpole, Robert Prouty, Jeremy Casas

Computer Science Faculty Publications and Presentations

A lightweight user-level process(ULP) package for parallel computing is described. Each ULP has its own register context, stack, data and heap space and communication with other ULPs is performed using locally synchronous, location transparent, message passing primitives. The aim of the package is to provide support for lightweight over-decomposition, optimized local communication and transparent dynamic migration. The package supports a subset of the Parallel Virtual Machine(PVM) interface[Sun90).

Fluttering Fountains: Stability Criteria, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

The fluttering oscillations that have long been seen in falling sheets of water have recently been subjected to detailed theoretical analysis. In this study stability criteria for these oscillations are derived and discussed. These criteria provide insight into the physical mechanisms of the instability and may be employed in the design of fluttering waterfall systems.

Faculty Senate Monthly Packet May 1994, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The May 1994 Monthly packet includes the May agenda and appendices and the Faculty Senate minutes and attachments from the meeting held April 1994.

Higher Education And Economic Issues In Oregon: A Current Picture, City Club Of Portland (Portland, Or.)

City Club of Portland

No abstract provided.

Logic Synthesis With High Testability For Cellular Arrays, Andisheh Sarabi

Dissertations and Theses

The new Field Programmable Gate Array (FPGA) technologies and their structures have opened up new approaches to logic design and synthesis. The main feature of an FPGA is an array of logic blocks surrounded by a programmable interconnection structure. Cellular FPGAs are a special class of FPGAs which are distinguished by their fine granularity and their emphasis on local cell interconnects. While these characteristics call for specialized synthesis tools, the availability of logic gates other than Boolean AND, OR and NOT in these architectures opens up new possibilities for synthesis. Among the possible realizations of Boolean functions, XOR logic is …

An Analysis Of The Linked-Pulse In Steady-State Free Precession In Mri, Fang Li

Dissertations and Theses

The steady-state free precession (SSFP) is one type of the fast scanning technique in MRI. So far most of its analysis are concentrated on the gradient echo SSFP (GR SSFP), very few paper discuss the spin echo SSFP (SE SSFP), and they are usually based on the simplified the hard pulse assumption. The advantage of the SE SSFP is that it can refocus the dephasing caused by the magnetic field inhomogeneity, which is the disadvantage of the GR SSFP. Also the hard pulse model can provide very limited information.

The purpose of this paper is to establish the soft pulse …

Performance Evaluation Tools For Interconnection Network Design, Anna Kolinska

Dissertations and Theses

A methodology is proposed for designing performance optimized computer systems. The methodology uses software tools created for performance monitoring and evaluation of parallel programs, replacing actual hardware with a simulator modeling the hardware under development. We claim that a software environment can help hardware designers to make decisions on the architectural design level. A simulator executes real programs and provides access to performance monitors from user's code. The performance monitoring system collects data traces when running the simulator and the performance analysis module extracts performance data of interest, that are later displayed with visualization tools. Key features of our methodology …

Faculty Senate Monthly Packet April 1994, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The April 1994 Monthly packet includes the April agenda and appendices and the Faculty Senate minutes and attachments from the meeting held March 1994.

Genetic Algorithms And Artificial Life, Melanie Mitchell, Stephanie Forrest

Computer Science Faculty Publications and Presentations

Genetic algorithms are computational models of evolution that play a central role in many artificial-life models. We review the history and current scope of research on genetic algorithms in artificial life, giving illustrative examples in which the genetic algorithm is used to study how learning and evolution interact, and to model ecosystems, immune system, cognitive systems, and social systems. We also outline a number of open questions and future directions for genetic algorithms in artificial-life research

Decentralization Of Urban Service Activities: An Empirical Study, Wonseon Kyung

Dissertations and Theses

Post-war metropolitan development in the United States has been mainly due to suburban growth which resulted in dispersal of population, retailing, manufacturing, wholesaling and services. What is known about service suburbanization is primarily derived from survey research on location choices done in localized cases. There has been no comprehensive work done using secondary data on revealed behavior.

This dissertation attempts that comprehensive study. The research analyzes the dynamics of locational structure of services in U.S. metropolitan areas from 1969 to 1989. The descriptive analysis of changes in the location coefficients provides evidence to demonstrate a spatial shifting of consumer oriented …