Physical Sciences and Mathematics Commons^™

Post-Stagnation Behavior In The Upstream Regions Of Ice Stream C, West Antarctica, Stephen F. Price, R. A. Bindschadler, Christina L. Hulbe, Ian R. Joughin

Geology Faculty Publications and Presentations

The region where two active tributaries feed into the now stagnant Ice Stream C (ISC), West Antarctica, is thickening. In this region, we observe a correlation between faster ice flow (the tributaries) and elevated topography. We conclude that stagnation of ISC resulted in compression and thickening along the tributaries, eventually forming a "bulge" on the ice-sheet surface. Modern hydraulic potential gradients would divert basal meltwater from ISC to Ice Stream B (ISB). These gradients are primarily controlled by the bulge topography, and so likely formed subsequent to trunk stagnation. As such, we argue against "water piracy" as being the cause …

Wholes And Parts In General Systems Methodology, Martin Zwick

Systems Science Faculty Publications and Presentations

Reconstructability analysis (RA) decomposes wholes, namely data in the form either of set-theoretic relations or multivariate probability distributions, into parts, namely relations or distributions involving subsets of variables. Data is modeled and compressed by variablebased decomposition, by more general state-based decomposition, or by the use of latent variables. Models, which specify the interdependencies among the variables, are selected to minimize error and complexity.

Private Agro-Environmental Management: Green Business Rising, David E. Ervin, Frank Casey

Economics Faculty Publications and Presentations

This article focuses on the role of business environmental management (BEM) in the food industry. Types of BEM; Benefits of implementing the practice; Importance of giving producers flexibility; How private strategies and ventures may succeed. This article is adapted from a keynote address prepared for Challenging the Agricultural Economics Paradigm, a symposium honoring Luther G. Tweeten, Anderson Professor of Agricultural Marketing, Trade and Policy, September 10-11, 2000, The Ohio State University, Columbus, Ohio.

Biodiversity: Connecting With The Tapestry Of Life, Elise F. Granek, Francisco Dallmeier, Alfonso Alonso, Peter H. Raven

Environmental Science and Management Faculty Publications and Presentations

Biodiversity is the extraordinary variety of life on Earth – from genes and species to ecosystems and the valuable functions they perform. E.O. Wilson, the noted biologist and author who coined the term “biodiversity,” explains it as “the very stuff of life.” Species and the ecosystems in which they live are indelibly linked. Conversion or loss of ecosystems inevitably impairs the species that depend on them. As well, changes in the life cycle of one species could impact the life cycles of many other species (including humans), alter ecosystems and ecosystem functions, and contribute to local, regional and, ultimately, global …

Rate-Matching Packet Scheduler For Real-Rate Applications, Kang Li, Jonathan Walpole, Dylan Mcnamee, Calton Pu, David Steere

Computer Science Faculty Publications and Presentations

A packet scheduler is an operating system component that controls the allocation of network interface bandwidth to outgoing network flows. By deciding which packet to send next, packet schedulers not only determine how bandwidth is shared among flows, but also play a key role in determining the rate and timing behavior of individual flows. The recent explosion of rate and timing-sensitive flows, particularly in the context of multimedia applications, has focused new interest on packet schedulers. Next generation packet schedulers must not only ensure separation among flows and meet real-time performance constraints, they must also support dynamic fine-grain reallocation of …

The Multiplicities Of A Dual-Thin Q-Polynomial Association Scheme, Bruce E. Sagen, John S. Caughman Iv

Mathematics and Statistics Faculty Publications and Presentations

Let Y=(X,{Ri}1≤i≤D) denote a symmetric association scheme, and assume that Y is Q-polynomial with respect to an ordering E₀,...,E_D of the primitive idempotents. Bannai and Ito conjectured that the associated sequence of multiplicities mi (0≤i≤D) of Yis unimodal. Talking to Terwilliger, Stanton made the related conjecture that mi≤mi+1 and mi≤mD−i for i<D/2. We prove that if Y is dual-thin in the sense of Terwilliger, then the …

Towards Comparative Profiling Of Parallel Applications With Pperfdb, Christian Leland Hansen

Dissertations and Theses

Due to the complex nature of parallel programming, it is difficult to diagnose and solve performance related problems. Knowledge of program behavior is obtained experimentally, with repeated runs of a slightly modified version of the application or the same code in different environments. In these circumstances, comparative performance analysis can provide meaningful insights into the subtle effects of system and code changes on parallel program behavior by highlighting the difference in performance results across executions.

I have designed and implemented modules which extend the PPerfDB performance tool to allow access to existing performance data generated by several commonly used tracing …

The Impact Of Fine Sediment On Stream Macroinvertebrates In Urban And Rural Oregon Streams, Raymond S. Hoy

Dissertations and Theses

Urbanization, often characterized by high impervious surface area, can result in excessive inputs of fine sediments into urban streams. Excessive fine sediments can blanket the stream bed filling the interstitial space in the substratum, which may have adverse effects on stream biota. A field survey was conducted in Oregon urban and non-urban basins to investigate the relationship between fine sediments and stream macroinvertebrates. Physical, chemical, and biological data were collected from 59 stream sites in two urban and two rural streams. The stream sites fulfilled a continuous sediment gradient, which ranged from a low of 2% of fine sediment in …

Control Challenges In Multi-Level Adaptive Video Streaming, Dylan Mcnamee, Charles Krasic, Kang Li, Ashvin Goel, Erik Walthinsen, David Steere, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Streaming video is one of the fastest-growing applications of the Internet. The Internet’s diversity and dynamism demands that video streams adapt to ensure maximum quality at all times. This paper describes the control challenges we have encountered in the Quasar project’s “multi-level” adaptive streaming video player. We first describe the framework and environment of the player. This framework uses software feedback to control resource allocation as well as the quality of media delivery. We present the control challenges raised by our framework, which include horizontal and vertical feedback composition, difficult to model systems, and unpredictable, non-linear actuators. We describe some …

Application Of Tree-Structured Regression For Regional Precipitation Prediction Using General Circulation Model Output, Xiangshang Li, David J. Sailor

Mechanical and Materials Engineering Faculty Publications and Presentations

This study presents a tree-structured regression (TSR) method to relate daily precipitation with a variety of free-atmosphere variables. Historical data were used to identify distinct weather patterns associated with differing types of precipitation events. Models were developed using 67% of the data for training and the remaining data for model validation. Seasonal models were built for each of 2 US sites: San Francisco, California, and San Antonio, Texas. The average correlation between observed and simulated daily precipitation data series is 0.75 for the training set and 0.68 for the validation set. Relative humidity was found to be the dominant variable …

Transgenic Crops: An Environmental Assessment, David E. Ervin, Sandra S. Batie, Rick Welsh, Chantal L. Carpentier, Jacqueline I. Fern, Nessa J. Richman, Mary A. Schulz

Economics Faculty Publications and Presentations

The report focuses on the environmental impacts of transgenic crops, and covers biosafety regulations in the US and EU, intellectual property rights, and market and trade developments.

Shubnikov–De Haas Effect In The Superconducting State Of An Organic Superconductor, J. Wosnitza, S. Wanka, J. Hagel, R. Häussler, H. V. Löhneysen, J. A. Schlueter, U. Geiser, P. G. Nixon, Rolf Walter Winter, Gary L. Gard

Chemistry Faculty Publications and Presentations

We report the observation of Shubnikov–de Haas (SdH) oscillations in the mixed state of the organic superconductor β″-(BEDT-TTF)₂SF₅CH₂CF₂SO₃ (Tc≈4.4K). At low temperatures the SdH oscillations persist clearly below the upper critical field Bc₂(0)≈3.6 T almost down to the field where the resistivity vanishes. Rather unusually, no additional damping of the SdH-signal amplitude — as well as of the de Haas–van Alphen amplitude — is observed in the superconducting state. This indicates that the damping in the vortex state of this quasi-two-dimensional superconductor is different in character to that observed for most three-dimensional materials.

Lava And Ice Interaction At Stratovolcanoes: Use Of Characteristic Features To Determine Past Glacial Extents And Future Volcanic Hazards, David T. Lescinsky, Jonathan H. Fink

Geology Faculty Publications and Presentations

Structures resulting from lava and ice interaction are common at glaciated stratovolcanoes. During summit eruptions at stratovolcanoes, meltwater is produced and travels freely down steep slopes and thin permeable valley glaciers, eroding the ice and enlarging preexisting glacial drainages. As a result, in this environment have produced few catastrophic floods. Lava flowing into the open channels and voids in the glaciers becomes confined and grows thicker, filling the available space and producing steep-sided bodies with smooth, bulbous contact surfaces. Quenching of lava against ice or by water forms small-scale features such as tensional fractures and glass. As the amount of …

The Cracker Patch Choice: An Analysis Of Post Hoc Security Techniques, Crispin Cowan, Heather Hinton, Calton Pu, Jonathan Walpole

Computer Science Faculty Publications and Presentations

It has long been known that security is easiest to achieve when it is designed in from the start. Unfortunately, it has also become evident that systems built with security as a priority are rarely selected for wide spread deployment, because most consumers choose features, convenience, and performance over security. Thus security officers are often denied the option of choosing a truly secure solution, and instead must choose among a variety of post hoc security adaptations. We classify security enhancing methods, and compare and contrast these methods in terms of their effectiveness vs. cost of deployment. Our analysis provides practitioners …

Structure And Phase Transitions Of The 6, 6-Cyclopropane Isomer Of C_ {61} H_ {2}, M. R. Stetzer, Paul A. Heiney, Peter W. Stephens, R. E. Dinnebier, Q. Zhu, Andrew R. Mcghie, Robert M. Strongin, B. M. Brandt, Amos B. Smith Iii

Chemistry Faculty Publications and Presentations

We have used x-ray powder diffraction and differential scanning calorimetry to study the crystalline structures and thermal behavior of the 6,6-cyclopropane isomer of C₆₁H₂. At room temperature, the C₆₁H₂ cyclopropane molecules, like those of the 6,5-annulene isomer and C₆₀O epoxide, are orientationally disordered and crystallize on a face-centered-cubic lattice such that their methylene groups are statistically disordered among the octahedral voids. Unlike 6,5−C₆₁H₂ and C₆₀O, the low-temperature structure is not Pa3¯, but rather a low-symmetry orthorhombic lattice in which a≈b

Dependence Among Spacings, Baha-Eldin Khaledi, Subhash C. Kochar

Mathematics and Statistics Faculty Publications and Presentations

In this paper, we study the dependence properties of spacings. It is proved that if X₁,..., X_n are exchangeable random variables which are TP₂ in pairs and their joint density is log-convex in each argument, then the spacings are MTP₂ dependent. Next, we consider the case of independent but nonhomogeneous exponential random variables. It is shown that in this case, in general, the spacings are not MTP₂ dependent. However, in the case of a single outlier when all except one parameters are equal, the spacings are shown to be MTP₂ dependent and, hence, …

Theoretical Basis For The Ce-Qual-W2 River Basin Model, Scott A. Wells, Thomas M. Cole

Civil and Environmental Engineering Faculty Publications and Presentations

The primary objective of this research is to integrate a riverine model into the existing W2 code that would provide the capability for modeling entire watersheds. This task was accomplished by the following steps:

• Formal derivation of governing equations and solution algorithm with general channel slope

• Detailed analysis of algorithm for linking branches and smooth implementation of boundary conditions between branches

• Algorithm development and changes to basic model code (including branch definitions with slope, slope correction to solution algorithm, transfer of momentum between internal branches)

These tasks were performed with the following constraints and initiatives:

• Utilize …

Simpson's Paradox Can Emerge From The N-Player Prisoner's Dilemma: Implications For The Evolution Of Altruistic Behavior, Jeffrey Alan Fletcher, Martin Zwick

Systems Science Faculty Publications and Presentations

Simulations of the n-player Prisoner’s Dilemma in multiple populations reveal that Simpson’s paradox can emerge in such game-theoretic situations. The relative proportion of cooperators can decrease in each separate sub-population, while the proportion of cooperators in the total population can nonetheless increase, at least transiently. Factors that determine the longevity of this effect are under investigation. The increase of altruistic behavior exhibited in these simulations is not based on reciprocal altruism, as there are no strategies conditional on other players’ past actions, nor does it depend on kin selection via inclusive fitness, as there are no genes. This model is …

Ce-Qual-W2, Version 3, Scott A. Wells, Thomas M. Cole

Civil and Environmental Engineering Faculty Publications and Presentations

CE-QUAL-W2 is a two-dimensional water quality and hydrodynamic code supported by the U.S. Army Engineer Research and Development Center (Cole and Buchak 1995). The model has been widely applied to stratified surface water systems such as lakes, reservoirs, and estuaries and computes water levels, horizontal and vertical velocities, temperature, and 21 other water quality parameters (such as dissolved oxygen, nutrients, organic matter, algae, pH, the carbonate cycle, bacteria, and dissolved and suspended solids). A typical model grid is shown in Figure 1 where the vertical axis is aligned with gravity.

This technical note documents the development of CE-QUAL-W2, Version 3, …

An Efficient Method For Band Structure Calculations In 3d Photonic Crystals, David C. Dobson, Jay Gopalakrishnan, Joseph E. Pasciak

Mathematics and Statistics Faculty Publications and Presentations

A method for computing band structures for three-dimensional photonic crystals is described. The method combines a mixed finite element discretization on a uniform grid with a fast Fourier transform preconditioner and a preconditioned subspace iteration algorithm. Numerical examples illustrating the behavior of the method are presented.

Aspects Of Information Flow, Andrew P. Black, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Along with our colleagues at the Oregon Graduate Institute and Georgia Institute of Technology, we have recently been experimenting with real-rate systems, that is, systems that are required to move data from one place to another at defined rates, such as 30 items per second. Audio conferencing or streaming video systems are typical: they are required to deliver video or audio frames from a source (a server or file system) in one place to a sink (a display or a sound generator) in another; the frames must arrive periodically, with constrained latency and jitter. We have successfully built such systems …

Establishing The Inundation Distance And Overtopping Height Of Paleotsunami From The Late-Holocene Geologic Record At Open-Coastal Wetland Sites, Central Cascadia Margin, Robert B. Schlichting

Dissertations and Theses

Mapping and stratigraphic investigations of back barrier, open-coastal plain sites have been used to establish minimum inundation distances and wave heights of tsunami produced by great subduction zone earthquakes in the central Cascadia margin. Cascadia tsunami deposits have been reported for many coseismic subsidence events in bay marsh settings where tidal-channel features focus tsunami energy. Variable magnitude (8.5±0.5 Mw), frequency (500±300 yr recurrence), and rupture geometry produce widely varying computer model outcomes for Cascadia tsunami inundation. The results presented in this thesis provide specific quantitative data regarding tsunami inundation at the open coast.

Anomalous sand sheets that have been characterized …

Simple Model For Mixing At Accelerated Fluid Interfaces With Shear And Compression, John D. Ramshaw

Physics Faculty Publications and Presentations

A simple model was recently described for predicting linear and nonlinear mixing at an unstable planar interface between two fluids of different density subjected to an arbitrary time-dependent variable acceleration history [J. D. Ramshaw, Phys. Rev. E 58, 5834 (1998)]. Here we generalize this model to include the Kelvin-Helmholtz (KH) instability resulting from a tangential velocity discontinuity delta u, as well as the effects of a uniform anisotropic compression or expansion of the mixing layer as a whole. The model consists of a second-order nonlinear ordinary differential equation of motion for the half-width h of the mixing layer. This equation …

Comparative Thermal-Expansion Study Of Β″-(Et)2sf5ch2cf2so3 And Κ-(Et)2cu(Ncs)2: Uniaxial Pressure Coefficients Of Tc And Upper Critical Fields, J. Müller, M. Lang, F. Steglich, J. A. Schlueter, A. M. Kini, U. Geiser, Javid Mohtasham, Rolf Walter Winter, Gary L. Gard, T. Sasaki, N. Toyota

Chemistry Faculty Publications and Presentations

We report high-resolution measurements of the coefficient of thermal expansion, α=l⁻¹ x (δl/δΤ), on single crystals of the organic superconductors β″-(ET)₂SF₅CH₂CF₂SO₃ and κ-(ET)₂Cu(NCS)₂. For both salts we find large and highly anisotropic phase-transition anomalies at Tc. Combining these data with literature results on the specific heat via the Ehrenfest relation, the uniaxial pressure coefficients of Tc can be determined. Most remarkably, a strikingly similar in-plane vs out-of-plane anisotropy is found for both compounds: the strong suppression of Tc observed in hydrostatic-pressure experiments is dominated by a huge negative uniaxial stress effect perpendicular to the conducting planes. Therefore we expect that …

Multiple Source Pools And Dispersal Barriers For Galápagos Plant Species Distribution, J. Alan Yeakley, John F. Weishampel

Environmental Science and Management Faculty Publications and Presentations

We reexamined geographic factors explaining the number of plant species on islands in the Galápagos Archipelago. We hypothesized that plant species richness (S) was related to the number of source pools and that plant species dispersal preferentially followed direct, oceanic pathways. To test different dispersal pathways from multiple source pools, the total number of islands within a given dispersal radius (i) was posed as the sum of the number of line-of-sight islands (C_i) and of the number of islands without line-of sight connection (B_i). In partial regression analyses, controlling for nearest island area (A₂) …

A Longitudinal Assessment Of Temperament In Octopus Bimaculoides, David Loyd Sinn

Dissertations and Theses

Cephalopods, including Octopus spp., are highly intelligent molluscs that play major roles in many marine food webs, both as top-level feeders (Ambrose, 1984) as well as by constituting a major source of protein for the animals above them (Lang, Hochberg, Ambrose, & Engle, 1997). They also are fascinating organisms for behavioral studies, with elaborate repertoires of behavior based on plasticity and learning (Wells, 1962a; 1962b; 1978) which in complexity rivals that of the vertebrates. The study of individual differences in behavior is a facet of behavioral research that has recently gained attention in the literature (Gosling & John, 1999). Traditionally, …

Two-Dimensional Fermi Liquid With Fixed Chemical Potential, J. Wosnitza, S. Wanka, J. Hagel, E. Balthes, N. Harrison, J. A. Schlueter, A. M. Kini, U. Geiser, Javid Mohtasham, Rolf Walter Winter, Gary L. Gard

Chemistry Faculty Publications and Presentations

de Haas-van Alphen measurements made on the organic metal β″-(ET)₂SF₅CH₂CF₂SO₃ reveal the existence of an ideal two-dimensional (2D) Fermi surface, but rather than having the conventional sawtooth wave form that is normally observed in all other 2D electron gases, instead, an ‘‘inverse sawtooth’’ wave form is observed, which is to be expected when the chemical potential is pinned at a constant value. While this proves the existence of the theoretically predicted quasi-one-dimensional band, it further implies that this band has an exceptionally large density of states.

Smart For One, Dumb For All. Review Of: Luxury Fever: Why Money Fails To Satisfy In An Era Of Excess By Robert H. Frank, Robert Costanza

Institute for Sustainable Solutions Publications and Presentations

Book review of Luxury Fever: Why Money Fails to Satisfy in an Era of Excess. Robert H. Frank. Free Press, New York, 1999.

Portable Wood Burning Field Stove: United States Patent, John B. Hall

Economics Faculty Publications and Presentations

The ornamental design for a portable wood burning field stove.

Infofilter: Supporting Quality Of Service For Fresh Information Delivery, Ling Liu, Calton Pu, Karsten Schwan, Jonathan Walpole

Computer Science Faculty Publications and Presentations

With the explosive growth of the Internet and World Wide Web comes a dramatic increase in the number of users that compete for the shared resources of distributed system environments. Most implementations of application servers and distributed search software do not distinguish among requests to different web pages. This has the implication that the behavior of application servers is quite unpredictable. Applications that require timely delivery of fresh information consequently suffer the most in such competitive environments. This paper presents a model of quality of service (QoS) and the design of a QoS-enabled information delivery system that implements such a …