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Ultrashort Pulse Production In Synchronously Pumped Mode-Locked Dye Laser Systems, Duncan Leo Macfarlane

Dissertations and Theses

The concern of this dissertation is the understanding and improvement of a class of lasers that is responsible for some of the shortest optical pulses available today. In particular, we seek ways to produce from synchronously pumped mode-locked dye laser systems, shorter pulses of higher intensity with improved pulse-to-pulse consistency. Specific topics.that are discussed herein include the study of the role of the pump pulse in synchronously pumped mode-locked lasers, the study of the pulse shaping and shortening due to an intracavity saturable absorber, and the study of a fundamental pulse train instability associated with these lasers.

Strategic Implications Of R&D Investment On Dynamic Business Systems, George F. Farrimond Jr.

Dissertations and Theses

The United States' ability to compete in many international markets has been based on competitive advantage in high-technology products. Until recently, these industries had a favorable trade balance but in 1987, it slipped to deficit of $0.6 billion. Management of research and development programs is one of the most important elements in remaining competitive. Therefore, this research study of 291 high-technology firms was undertaken to determine if: (1) a positive relationship exists between the amount of investment in research and development (R&D) and a firms success in sales, net income, or market share, (2) excessive investment in R&D would decrease …

Parallel Architectures For Solving Combinatorial Problems Of Logic Design, Phuong Minh Ho

Dissertations and Theses

This thesis presents a new, practical approach to solve various NP-hard combinatorial problems of logic synthesis, logic programming, graph theory and related areas. A problem to be solved is polynomially time reduced to one of several generic combinatorial problems which can be expressed in the form of the Generalized Propositional Formula (GPF) : a Boolean product of clauses, where each clause is a sum of products of negated or non-negated literals.

Slope Stability As Related To Geology At Rainier, Columbia County, Oregon, James Douglas Gless

Dissertations and Theses

Rainier, Oregon, has experienced problems in the development of residential and commercial sites, utilities, and transportation facilities as a result of slope instability. This study of slope stability at Rainier was conducted at the request of city officials.

The Effects Of Bandwidth Limiting Tuning Elements On A Synchronously Pumped Mode-Locked Dye Laser, Bahram Zandi

Dissertations and Theses

In this study an improved description of the bandwidth limiting tuning filters has been introduced into a semiclassical model for a synchronously pumped mode-locked dye laser system. This model is an improvement over the traditional rate equation approach since it has detailed representations of the energy levels, rotational distribution, and coherence effects. The new set of equations has been solved numerically using the best available values for the various parameters, and autocorrelations have been computed for a range of different length detuning and bandwidth limiting elements. In the experiments, an acousto-optically mode-locked argon ion laser is used to synchronously pump …

Meeting Notes 1988-12-08 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

A Cmos Circuit Generator Using Differential Pass Transistors For Implementing Boolean Functions, Rabe'eh Mahooti

Dissertations and Theses

This study uses differential pass transistor methodology for implementing and evaluating Boolean functions. The main goal is investigation of CMOS and nMOS approaches in pass transistor logic design. Pass-transistor logic is most effective in the implementation of Boolean functions when the vectors are in the same format. It has been demonstrated that nMOS pass transistor logic driven by a control signal voltage above the V_dd level offers a significant improvement in speed. nMOS pass transistorsalso offer less area consumption in comparison to the CMOS approach.

The philosophy developed here has been used in the design of a program for …

Governing And Managing Multi-Modal Transit Agencies In A Multicentric Era, Sy Adler, Sheldon Edner

Center for Urban Studies Publications and Reports

We explore the dynamics of governing and managing multi-modal regional transit agencies through a case study of the Tri-County Metropolitan Transit District (Tri-Met), which provides bus and rail transit services to the Portland, Oregon, metropolitan area (see map). Along with other similarly constituted firms in the United States transit industry, Tri-Met confronts the challenge of providing service in a geopolitical context that is quite different than when the agency was created. The critical new element in Tri-Met's operating environment is the emergence of several suburban business centers that effectively compete with the Portland central business district (CBD), and are seeking …

Meeting Notes 1988-11-10 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

A Lagrangian For A System Of Two Dyons, Rainer Georg Thierauf

Dissertations and Theses

Maxwell's equations for the electromagnetic field are symmetrized by introducing magnetic charges into the formalism of electrodynamics. The symmetrized equations are solved for the fields and potentials of point particles. Those potentials, some of which are found to be singular along a line, are used to formulate the Lagrangian for a system of two dyons (particles with both electric and magnetic charge). The equations of motion are derived from the Lagrangian. It is shown that the dimensionality constants k and k*, which were introduced to define the units of the electromagnetic fields, have to be equal in order to avoid …

Geographic Information Systems: Research Issues, Kenneth Dueker

Center for Urban Studies Publications and Reports

GIS research has evolved by trial and error. We need to think more systematically about GIS research. New technology and societal needs are important determinants of issues that govern GIS research strategies. URISA has a stake in fostering GIS research, particularly research that is appliications driven.

Report On State Measure 6: Indoor Clean Air Law Revisions Banning Public Smoking, City Club Of Portland (Portland, Or.)

City Club of Portland

No abstract provided.

Meeting Notes 1988-10-13 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

Infrastructure Politics: The Dynamics Of Crossing San Francisco Bay, Sy Adler

Urban Studies and Planning Faculty Publications and Presentations

Analyzes the efforts to deal with the San Francisco Bay Bridge controversy, 1945-59, to develop a theory of the politics of transport infrastructure projects by studying the influence of urban rivalry and the circumstances that allow political stalemates to be broken.

Meeting Notes 1988-09-08 , 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 quarterly. In this issue: Predicting presidential performance is the subject of the day for professors Jim Heath and David Smeltzer; paint brush to canvas has become light pen to video terminal in one Art Department office; advanced degrees in science and engineering are the focus of far-reaching plans at Portland State; a professor and a student from PSU heads up an experimental needle exchange program; and more.

Modeling Cadastral Spatial Relationships, Kenneth Dueker, Daniel Kjerne

Center for Urban Studies Publications and Reports

Research exploring the object-oriented paradigm as a tool with which to model location of objects in maps is reported. The research led us into three areas:

• the use of an object-oriented language, Smalltalk.-80 to model cadastral location using the object-oriented paradigm.
• study of the development of spatial information systems, such as engineering design and computer-aided design(CAD) database systems based on object-oriented ideas, to see how that approach might be useful for developing a mapping system.
• Finally, the conceptual exploration of how an object-oriented approach might facilitate linkages of location among layers of a land information system.

Future research is needed …

Logic Design Using Programmable Logic Devices, Loc Bao Nguyen

Dissertations and Theses

The Programmable Logic Devices, PLO, have caused a major impact in logic design of digital systems in this decade. For instance, a twenty pin PLO device can replace from three hundreds to six hundreds Transistor Transistor Logic gates, which people have designed with since the 60s. Therefore, by using PLD devices, designers can squeeze more features, reduce chip counts, reduce power consumption, and enhance the reliability of the digital systems.

This thesis covers the most important aspects of logic design using PLD devices. They are Logic Minimization and State Assignment. In addition, the thesis also covers a seldomly used but …

Meeting Notes 1988-08-11 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

Meeting Notes 1988-07-14 , 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 quarterly. In this issue: Making improvements in our justice system is more than an academic exercise for PSU’s Administration of Justice; using a new fitness test, PSU researchers are finding safer ways for the elderly to exercise; History Professor Gordon Dodds writes a book on the first 50 years at Portland State; and more.

The Lunar Date Of Ramesses Ii, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Due largely to the efforts of R. A. Parker, the various calendars used in Egypt are now fairly well understood. Dates which the Egyptians expressed in both their civil and lunar calendars can sometimes be determined exactly, and the study of such dates has been extremely important in efforts to establish an accurate Egyptian chronology. However, the successful use of this method obviously depends on one's ability to reconstruct accurately the astronomical and observational conditions on which the lunar calendar was based. The author re-examined the methods used to calculate lunar dates and have suggested some ways in which those …

Hedonic Analysis Of Gasoline Retailing, Soleman A. Al-Bassir

Dissertations and Theses

Researchers have difficulty modeling the influence of retailing attributes on consumer choice. The literature of retailing that has dealt with this issue has conventionally used experimental data for estimating the influence of retailing attributes on consumer behavior. The present research applies hedonic analysis to the measurement of the value of retailing attributes. This is accomplished by applying hedonic specifications to supply and demand models for the retail sales of unleaded gasoline for the purpose of estimating the influence of specified retailing attributes on retail prices. Four retailing attributes-accessibility, convenience, service, and competition-were expected to have a determinable value that was …

The Decay And Formation Of One-Dimensional Nonconservative Shocks, Marek Elźanowski, Marcelo Epstein

Mathematics and Statistics Faculty Publications and Presentations

The method of singular surfaces is used to obtain explicit conditions under which a one-dimensional acceleration wave develops into a shock when some dissipation mechanism is present. The conditions which secure the initial growth of the strong shock wave propagating into an undeformed nonlinear and dissipative medium are also derived. The analysis is pre- sented for a single balance law, one-dimensional elasticity, and the non- linear Maxwellian continuum.

Implementing Ray Tracing Algorithm In Parallel Environment, Tjah Jadi

Dissertations and Theses

Ray tracing is a very popular rendering algorithm in the field of computer graphics because it can generate highly-realistic images from three-dimensional models. Unfortunately, the computational cost is very expensive. To speed up the rendering process we present both static and dynamic scheduling (balancing) strategies for a multiprocessor system. Hence, the load balancing among the processors is the most important problem in parallel processing. The implementation of the algorithm is based on a modified octree structure.

Dc-Excited Cw Co₂ Metal Waveguide Laser, Fahad Saleh Al-Mashaabi

Dissertations and Theses

A novel design for a DC excited cw CO₂ metal waveguide laser has been developed in which a slotted hollow-cathode in a transverse discharge also doubles as a metal waveguide. This design has been implemented in a compact design that produces up to 1 watt of cw, 10.6 μm radiation. The discharge characteristics, laser gain and laser output has been studied as functions of various discharge parameters. The advantages of the new transverse discharge of the slotted hollow cathode geometry include low voltage, positive impedence and high optical gain. Overall efficiency is comparable with those of conventional longitudinal CO …

Report On Formation Of Pioneer People's Utility Districts No. 1 And No. 02 (Multnomah County Ballot Measures 26-7 And 26-8), City Club Of Portland (Portland, Or.)

City Club of Portland

No abstract provided.

Meeting Notes 1988-05-12 , Joint Policy Advisory Committee On Transportation

Joint Policy Advisory Committee on Transportation

No abstract provided.

Spontaneous Coherent Pulsations In Standing-Wave Laser Oscillators, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Spontaneous pulsation phenomena in xenon lasers are now well known, and related effects have been observed with other laser types. Most theoretical analyses of such pulsations are formulated for unidirectional ring lasers, whereas most experiments involve standing-wave resonator geometries. Described here are rigorous semiclassical models governing the spontaneous pulsation instability in standing-wave laser oscillators. The standing-wave results are more complex and closer to experimental observations than the ring results for operation in the Lambdip region near line center.

Spectral Behavior And Pulse Train Instabilities Of A Synchronously Pumped Mode-Locked Dye Laser, Duncan Leo Macfarlane, Lee W. Casperson, Anthony A. Tovar

Electrical and Computer Engineering Faculty Publications and Presentations

The pulse-train envelope of a synchronously pumped mode-locked dye laser has been experimentally studied as a function of cavity length detuning. When a bandwidth-limiting birefringent tuning filter is included and the cavity is adjusted to the length that yields optimally short (˜2-psec) pulse, there is a slow (≤800 kHz), erratic amplitude modulation that provides a 20% variation in pulse energies. As the cavity length is detuned on the order of one part in 10⁴, the modulation vanishes, but the individual pulse lengths increade dramtically. Further detuning results in a clean periodic envelope with a 20% modulation depth and a˜5-μsec period. …