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Articles 5791 - 5820 of 6893
Full-Text Articles in Entire DC Network
Researchers Pool Knowledge About Antarctic Dry Valleys, Andrew G. Fountain, Sarah Spaulding
Researchers Pool Knowledge About Antarctic Dry Valleys, Andrew G. Fountain, Sarah Spaulding
Geology Faculty Publications and Presentations
Most of us think of ice when we think of the Antarctic, and rightly so, considering that only 5% of it is ice-free. Dry valleys--the ice-free areas--have sandy, rocky valley floors, ice-covered lakes, and streams that flow only two months of the year. The McMurdo Dry Valleys (78øS 163øE) are the largest of these regions.
Dynamic Load Distribution In Mist, K. Al-Saqabi, R. M. Prouty, Dylan Mcnamee, Steve Otto, Jonathan Walpole
Dynamic Load Distribution In Mist, K. Al-Saqabi, R. M. Prouty, Dylan Mcnamee, Steve Otto, Jonathan Walpole
Computer Science Faculty Publications and Presentations
This paper presents an algorithm for scheduling parallel applications in large-scale, multiuser, heterogeneous distributed systems. The approach is primarily targeted at systems that harvest idle cycles in general-purpose workstation networks, but is also applicable to clustered computer systems and massively parallel processors. The algorithm handles unequal processor capacities, multiple architecture types and dynamic variations in the number of processes and available processors. Scheduling decisions are driven by the desire to minimize turnaround time while maintaining fairness among competing applications. For efficiency, the virtual processors (VPs) of each application are gang scheduled on some subset of the available physical processors.
Limitations Of Methods For Determining The Position Of The Center Of Mass Of A Human Subject Performing A Sit-Up, Terrence Chadwick Smith
Limitations Of Methods For Determining The Position Of The Center Of Mass Of A Human Subject Performing A Sit-Up, Terrence Chadwick Smith
Dissertations and Theses
The knowledge of the position of the center of mass of a human subject performing a sit-up could help us understand the coordination of the sit-up motion. This thesis investigates the limits in three methods of determining the center of mass of a human subject. The three methods are the anthropometric method, the dynamic method, and the static torque method. The anthropometric method is a standard method that uses measurements of the subject to estimate the mass properties of individual segments of the body. The center of mass of the body is calculated from the mass and positions of the …
Erp Analysis Using Matched Filtering, Correlation Coefficient And Mann-Whitney Test, Yun Yan
Erp Analysis Using Matched Filtering, Correlation Coefficient And Mann-Whitney Test, Yun Yan
Dissertations and Theses
Event related potentials (ERPs) carry very important information that relate to the performance of the brain functions of a human being. Further studies have identified that the late positive complex (LPC) are affected by the memory process.
The matched filter method is used to improve the signal-to-noise ratio of signal ERPs. We use the output of the matched filter to distinguish the difference of the waveforms. In our study, we found that the peak values of the matched filter output differed among normal subjects and memory-impaired subjects.
The correlation coefficient is a statistical value that can be applied to find …
The Column Multiplicity Problem In Decomposition Of Functions And Relations, Rahul Malvi
The Column Multiplicity Problem In Decomposition Of Functions And Relations, Rahul Malvi
Dissertations and Theses
Finding the column multiplicity in Functional Decomposition has been known to be one of the most important problems to be solved in the process of functional decomposition of discrete functions. A lot of research has been done in this field with many new heuristics generated to find the column multiplicity, but there has not been an evaluation of the algorithms on the kinds of graphs that occur in decomposition and whether having an exact method to calculate the column multiplicity is useful from the overall design goals.The intent of this thesis was to investigate the column multiplicity problem, in order …
Faculty Senate Monthly Packet June 1997, Portland State University Faculty Senate
Faculty Senate Monthly Packet June 1997, Portland State University Faculty Senate
Faculty Senate Monthly Packets
The June 1997 Monthly packet includes the June agenda and appendices and the Faculty Senate minutes and attachments from the meeting held May 1997.
Review Of The United States Environmental Protection Agency Superfund Technical Assistance Grant Program, Robert Leslie Annear, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt
Review Of The United States Environmental Protection Agency Superfund Technical Assistance Grant Program, Robert Leslie Annear, Scott A. Wells, Shuguang Li, Marvin Beeson, Michael L. Cummings, Richard Pratt
Civil and Environmental Engineering Faculty Publications and Presentations
The EPA Technical Assistance Grant Program has been around for several years, but there are not many examples of its use in the Pacific Northwest from which citizens can learn from when considering applying for a Technical Assistance Grant. The EPA program is designed to provide citizens with technical assistance in understanding the issues related to a Superfund site (or proposed Superfund site) in their community. This report provides an overview of the Technical Assistance Grant Program with information on applying for the grant, selecting a Technical Advisor and managing the grant. Additionally two case studies are reviewed in order …
A Toolkit For Specializing Production Operating System Code, Crispin Cowan, Dylan Mcnamee, Andrew P. Black, Calton Pu, Jonathan Walpole, Charles Krasic, Perry Wagle, Qian Zhang
A Toolkit For Specializing Production Operating System Code, Crispin Cowan, Dylan Mcnamee, Andrew P. Black, Calton Pu, Jonathan Walpole, Charles Krasic, Perry Wagle, Qian Zhang
Computer Science Faculty Publications and Presentations
Specialization has been recognized as a powerful technique for optimizing operating systems. However, specialization has not been broadly applied beyond the research community because the current techniques, based on manual specialization, are time-consuming and error-prone. This paper describes a specialization toolkit that should help broaden the applicability of specializing operating systems by assisting in the automatic generation of specialized code, and {\em guarding} the specialized code to ensure the specialized system continues to be correct. We demonstrate the effectiveness of the toolkit by describing experiences we have had applying it in real, production environments. We report on our experiences with …
Syntheses And Characterizations Of Unsymmetrical Porphyrins As Photosensitizers For A Solid-State Solar Cell, Yinping Zhao
Syntheses And Characterizations Of Unsymmetrical Porphyrins As Photosensitizers For A Solid-State Solar Cell, Yinping Zhao
Dissertations and Theses
Solar light is the most important source of regenerative energy and represents mankind's only inexhaustible energy source. One of today's most promising tools to make use of solar energy is its direct conversion into electrical energy in a photovoltaic cell. The practical use of these solar cells depends on the price of the devices and therefore of the obtained energy. The conventional silicon cells, although efficient, are expensive for common consumer applications. The Grätzel cell is a photovoltaic system for harvesting the sun's energy that operates at about 10-15% overall efficiency, like a conventional solar cell, but does it at …
Settlements Due To Arid Collapsible Soils, Heather L. Devine
Settlements Due To Arid Collapsible Soils, Heather L. Devine
Dissertations and Theses
The arid alluvial deposits common to the western United States frequently undergo moderate to severe collapse when wetted that can threaten or destroy the stability of structures that are founded on such soils. Additionally, in some areas collapse has been known to occur due to overburden stresses alone. As development expands in these areas a method to estimate the degree of this collapse is essential.
Current settlement methods are reviewed and evaluated as they apply to collapsible soils, providing a basis for the development of a proposed settlement method for determining collapse. To aid in the determining the basis for …
Geochemistry, Stratigraphy And Provenance Of The Portland Hills Silt In The Tualatin Mountains, Portland, Oregon, John L. Lawes Iii
Geochemistry, Stratigraphy And Provenance Of The Portland Hills Silt In The Tualatin Mountains, Portland, Oregon, John L. Lawes Iii
Dissertations and Theses
Soil morphology and geochemistry of loess were investigated at nine sites in the Tualatin Mountains west of Portland and at additional sites in The Dalles, eastern Washington and Puget Sound. A total of forty samples were examined using Instrumental Neutron Activation Analysis (INAA).
Stratigraphic relationships and soil development suggest that the PHS ages of Lentz (1977) be revised. The age of the Portland Hills Silt (PHS) ranges from 12,000 to at least 960,000 years before present.
The geochemistry of the PHS supports the Lentz (1977) hypothesis of the PHS as a loess of continental origin. Thorium/scandium ratios in the PHS …
Molecular Fluorescence At A Rough Surface: The Orientation Effects, William Lee Blacke
Molecular Fluorescence At A Rough Surface: The Orientation Effects, William Lee Blacke
Dissertations and Theses
The interaction between an emitting molecular dipole and a conducting substrate with a periodic surface roughness is looked at with particular interest in the different orientations of the dipole with respect to the substrate surface. A previous dynamical, perturbative theory for the effects of perpendicular dipole is extended to treat a dipole oriented parallel to the surface of the substrate. The results are then applied to study the modified fluorescence characteristics of the emitting dipoles. Numerical results demonstrate that some fluorescence characteristics are extremely sensitive to the molecular orientation with the dipole oriented along the grating (x direction) exhibiting unique …
Early To Middle Pleistocene Catastrophic Flood Deposits, The Dalles, Oregon, David Irving Cordero
Early To Middle Pleistocene Catastrophic Flood Deposits, The Dalles, Oregon, David Irving Cordero
Dissertations and Theses
A roadcut on Highway 197, three kilometers southeast of The Dalles, Oregon, exposes a sequence of Quaternary sediments and five buried paleosols. The sediments, paleosols, and associated tephras at this site provide evidence of a Quaternary history of catastrophic flooding in the Columbia Basin extending back at least 700 ka and of an early eruption (ca. 600 ka) of Mount Adams. Four sedimentary units are exposed in this cut: Holocene loess, late Wisconsin Missoula Flood slackwater deposits, five pre-late Wisconsin catastrophic flood slackwater deposits bearing well developed paleosols, and late Tertiary Dalles Formation volcaniclastics. All but the oldest are predominantly …
Post-Middle Miocene Geologic History Of The Tualatin Basin, Oregon With Hydrogeologic Implications, Doyle Coley Wilson
Post-Middle Miocene Geologic History Of The Tualatin Basin, Oregon With Hydrogeologic Implications, Doyle Coley Wilson
Dissertations and Theses
The geologic history and sedimentary till of the Tualatin Basin after Columbia River Basalt Group (CRBG) emplacement is assessed and related to groundwater characteristics. The 334 m deep HBD-1 core from the Hillsboro Airport, provides the primary information for sediment characterization and is supported by over 2400 well logs and cores, and four seismic lines. The sedimentary section above the 26 m thick paleosol on the CRBG in HBD-I is divided into two main groups: a 25 m thick section of Missoula flood sediments called the Willamette Silt overlies a 263 m thick finegrained sequence of fluvial Neogene sediments.
Pollen, …
Geochemical Characteristics And Correlations Within The Triassic-Jurassic Age Gabbs And Sunrise Formations Of West Central Nevada, Karen Elizabeth Boelling
Geochemical Characteristics And Correlations Within The Triassic-Jurassic Age Gabbs And Sunrise Formations Of West Central Nevada, Karen Elizabeth Boelling
Dissertations and Theses
Trace and minor element geochemistry was determined using Instrumental Neutron Activation Analysis for ninety-six (96) limestone and calcareous siltstone samples from four stratigraphic sections in the Triassic-Jurassic age Gabbs and Sunrise formations of west central Nevada. Geochemical data support lithologic and faunal interpretations of relative basin positions of the Sunrise Formation stratigraphic sections, as well as basin development (including transgressive-regressive sequences) during deposition of the Gabbs and Sunrise formations at New York Canyon (Gabbs Valley Range). All sections show characteristics of both oceanic and continental island arc sources. Rare positive Eu anomalies relative to chondrites suggest that the Gabbs Formation …
Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole
Predictable File Access Latency For Multimedia, Dan Revel, Crispin Cowan, Dylan Mcnamee, Calton Pu, Jonathan Walpole
Computer Science Faculty Publications and Presentations
Multimedia applications are sensitive to I/O latency and jitter when accessing data in secondary storage. Transparent adaptive prefetching (TAP) uses software feedback to provide multimedia applications with file system quality of service (QoS) guarantees. We are investigating how QoS requirements can be communicated and how they can be met by adaptive resource management. A preliminary test of adaptive prefetching is presented.
Distribution Of Heavy Metals And Trace Elements In Soils Of Southwest Oregon, Rafiqul Alam Khandoker
Distribution Of Heavy Metals And Trace Elements In Soils Of Southwest Oregon, Rafiqul Alam Khandoker
Dissertations and Theses
Soil samples from 118 sites on 71 geologic units in southwest Oregon were collected and analyzed to determine the background concentrations of metals in soils of the region. Sites were chosen in areas that were relatively undisturbed by human activities. The U.S. Environmental Protection Agency approved total-recoverable method was used to recover metals from samples for analysis. The twenty six metals analyzed were: Ag, AI, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Tl, V and Zn.
The Klamath Mountains followed by the Coast Range contain the …
Generalized Beam Matrices. Iv. Optical System Design, Anthony A. Tovar, Lee W. Casperson
Generalized Beam Matrices. Iv. Optical System Design, Anthony A. Tovar, Lee W. Casperson
Electrical and Computer Engineering Faculty Publications and Presentations
Systematic procedures are presented for determining the optical components needed to produce an arbitrary transformation of a Gaussian light beams's spot size, radius of curvature, displacement, and direction of propagation. As an example, an optical system is considered that spatially separates the two coincident Gaussian beams produced by a high-diffraction-loss resonator that uses a Gaussian variable-reflectivity output coupler. In addition, an ABCDGH reverse matrix theorem and an ABCDGH Sylvester theorem are also derived. These matrix theorems may be used to satisfy special constraints inherent in the design of multipass and periodic optical systems.
Rate-Equation Approximations In High-Gain Lasers, Lee W. Casperson
Rate-Equation Approximations In High-Gain Lasers, Lee W. Casperson
Electrical and Computer Engineering Faculty Publications and Presentations
The rate-equation approximation is one of the most fundamental and universally employed simplifications in laser analyses. The accuracy and regions of applicability of this approximation are explored in comparisons with more rigorous semiclassical models. Higher-order rate-equation approximations are also developed, and these improved models can yield much better accuracy than conventional rate equations with little added complexity. The modified adiabatic elimination methods reported here would also be useful in reducing the mathematical models governing other physical systems.
Tool Condition Monitoring: A Computational Approach, Anthony Clinch
Tool Condition Monitoring: A Computational Approach, Anthony Clinch
Dissertations and Theses
Tool Condition Monitoring offers a new approach to reducing the costs associated with catastrophic tool failure. The manufacturing process is becoming more computationally oriented all the time. Computational methods of determining the condition of cutting tools will lend themselves to easy integration with current and forthcoming manufacturing techniques. Coupling the results of this computational approach with a cost analysis will provide a means of maximizing the investment in cutting tools, while minimizing the damage caused by tool failure. Tool Condition Monitoring, as defined here, is a method of computationally determining the condition of a cutting tool. The problem of determining …
The Columbia Slough, Scott A. Wells
The Columbia Slough, Scott A. Wells
Civil and Environmental Engineering Faculty Publications and Presentations
This report was written in an attempt to provide the public and Bureau of Environmental Services Staff with a summary of work accomplished on the Columbia Slough system by Portland State University and other consultants working on the Slough over the last 6 years. An attempt was made to create an easy-to-read report with important overviews of the "big picture", glossary of definitions, index, and further details to assist in technology transfer.
Interaction Of Fluctuating River Flow With A Barotropic Tide: A Demonstration Of Wavelet Tidal Analysis Methods, David A. Jay, Edward P. Flinchem
Interaction Of Fluctuating River Flow With A Barotropic Tide: A Demonstration Of Wavelet Tidal Analysis Methods, David A. Jay, Edward P. Flinchem
Civil and Environmental Engineering Faculty Publications and Presentations
Wavelet transforms provide a valuable new tool for analysis of tidal processes that deviate markedly from an assumption of exact periodicity inherent in traditional harmonic analysis. A wavelet basis adapted to nonstationary tidal problems is constructed and employed to analyze the modulation of the external tide in a river by variations in streamflow. Interaction of a surface tide with river flow is the best available demonstration of the continuous wavelet transform (CWT) methods developed. It is the simplest and perhaps the only nonstationary tidal process for which both sufficient data and dynamical understanding exist to allow detailed comparisons between CWT …
State Funding For Special Education In Oregon : Calculating Cost Differentials Of Special Education For Handicapped Students In Oregon School Districts, Kyung-Sup Kim
Dissertations and Theses
A general principle of school finance is that the cost of the educational program is influenced by varying characteristics of students and school districts. This raises the question of whether state allocation policies should reflect the additional costs associated with particular educational programs, such as special education for handicapped students, vocational, compensatory, bilingual education, and gifted and talented education programs as well as cost differences associated with size, salaries, and related issues. Thus, it is essential for state government to identify cost differentials for special education programs in terms of various school districts to determine the importance of such differences …
A Telescopic Approach To Modeling Leachate Dynamics And Migration At The St. Johns Landfill, Portland, Oregon, Thomas Stephen Lowry
A Telescopic Approach To Modeling Leachate Dynamics And Migration At The St. Johns Landfill, Portland, Oregon, Thomas Stephen Lowry
Dissertations and Theses
The St. Johns Landfill is a 225-acre site that lies near the confluence of the Columbia and Willamette Rivers, in the North Portland Industrial District of Portland, Oregon. A slough system surrounds the landfill on three sides with the fourth side adjacent to a shallow lake. The landfill first opened in 1930 when it was operated as an open dump. It operated as an open dump until 1969 when it was converted to a sanitary landfill, employing daily cover and compaction. The landfill was closed in 1991.
The landfill sits directly on top of a thick layer of silty overbank …
Numerical Simulation Of Contaminated Sediment Transport In The Upper Columbia Slough System, Binghong Wu
Numerical Simulation Of Contaminated Sediment Transport In The Upper Columbia Slough System, Binghong Wu
Dissertations and Theses
An integrated modeling system has been developed to simulate sediment and contaminated sediment transport in the Upper Columbia Slough System during the Flood of 1996. The modeling system consists of a hydrodynamic model, a sediment transport model, and a contaminant transport model. The hydrodynamic model predicts the Slough flow dynamics and sediment transporting power; the sediment transport model predicts flow-induced sediment transport; and the contaminant transport model predicts the migration of contaminated sediments in the Slough system.
The Upper Columbia Slough modeling system is characterized by its recognition of the complex interplay of Slough hydrology, hydrodynamics, sediment transport, contaminant transport. …
Faculty Senate Monthly Packet February 1997, Portland State University Faculty Senate
Faculty Senate Monthly Packet February 1997, Portland State University Faculty Senate
Faculty Senate Monthly Packets
The February 1997 Monthly packet includes the February agenda and appendices and the Faculty Senate minutes and attachments from the meeting held January 1997.
Complexity Theory And Systems Theory, Martin Zwick
Complexity Theory And Systems Theory, Martin Zwick
Complex Systems Faculty Publications and Presentations
I use the label, “complexity theory,” for the research program which studies nonlinear dynamics, “complexity,” “complex adaptive systems,” “artificial life,” etc., and whose intellectual Mecca in the United States is the Santa Fe Institute. I use the label, “systems theory,” for the research program which crystallized after World War II under the names of “general systems theory” and “cybernetics,” and which subsumed such postwar scientific developments as information theory, game theory, feedback control theory, and the beginnings of computer science and artificial intelligence. The central thesis of this paper is that complexity theory is a continuation and revitalization of systems …
Annual Faculty Senate Minutes October 1997 - June 1998, Portland State University Faculty Senate
Annual Faculty Senate Minutes October 1997 - June 1998, Portland State University Faculty Senate
Annual Compilations of the Faculty Senate Minutes (Minutes Only)
Minutes of the Faculty Senate for October 1997 to June 1998.
A Migratable User-Level Process Package For Pvm, Ravi Kunuru, Steve Otto, Jonathan Walpole
A Migratable User-Level Process Package For Pvm, Ravi Kunuru, Steve Otto, Jonathan Walpole
Computer Science Faculty Publications and Presentations
Shared, multi-user, workstation networks are characterized by unpredictable variability in system load. Further, the concept of workstation ownership is typically present. For efficient and unobtrusive computing in such environments, applications must not only overlap their computation with communication but also redistribute their computations adaptively based on changes in workstation availability and load. Managing these issues at application level leads to programs that are difficult to write and debug. In this paper, we present a system that manages this dynamic multi-processor environment while exporting a simple message-based programming model of a dedicated, distributed memory multiprocessor to applications. Programmers are thus insulated …
Metropolitan Briefing Book, 1997, Carl Abbott, W. Warren Wagar, Ethan Seltzer, Craig Wollner, Howard Wineberg
Metropolitan Briefing Book, 1997, Carl Abbott, W. Warren Wagar, Ethan Seltzer, Craig Wollner, Howard Wineberg
Institute of Metropolitan Studies Publications
The Metropolitan briefing book was developed to provide elected and appointed leaders in the six counties with information about issues and trends common to all corners of the region.