Engineering Commons^™

Semantic Components: A Model For Enhancing Retrieval Of Domain- Specific Information, Susan Loucette Price

Dissertations and Theses

Despite the success of general Internet search engines, information retrieval remains an incompletely solved problem. Our research focuses on supporting domain experts when they search domain-specific libraries to satisfy targeted information needs. The semantic components model introduces a schema specific to a particular document collection. A semantic component schema consists of a two-level hierarchy, document classes and semantic components. A document class represents a document grouping, such as topic type or document purpose. A semantic component is a characteristic type of information that occurs in a particular document class and represents an important aspect of the document’s main topic. …

Bottom Profiling By Correlating Beam-Steered Noise Sequences, Chris H. Harrison, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

It has already been established that by cross-correlating ambient noisetime series received on the upward and downward steered beams of a drifting vertical array one can obtain a subbottom layer profile. Strictly, the time differential of the cross correlation is the impulse response of the seabed. Here it is shown theoretically and by simulation that completely uncorrelated surfacenoise results in a layer profile with predictable amplitudes proportional to those of an equivalent echo sounder at the same depth as the array. The phenomenon is simulated by representing the sound sources as multiple random time sequences emitted from random locations in …

Nano Quasicrystal Formation And Local Atomic Structure In Zr––Pd And Zr––Pt Binary Metallic Glasses, Junji Saida, Takashi Sanada, Shigeo Sato, Muneyuki Imafuku, Chunfei Li, Akihisa Inoue

Center for Electron Microscopy and Nanofabrication Publications and Presentations

Formation of the nanoscale icosahedral quasicrystalline phase (I-phase) in the melt-spun Zr₇₀Pd₃₀ and Zr₈₀Pt₂₀ binary metallic glasses were reported. Local atomic structure in the glassy and quasicrystal (QC)-formed states were also analyzed by XRD and EXAFS measurements in order to investigate the formation mechanism of QC phase. The distorted icosahedral-like local structure can be identified around Zr atom in the Zr₇₀Pd₃₀ metallic glass. In the QC formation process, a change of local environment around Zr is detected, in which the approximately one Zr atom substitutes for one Pd atom. In contrast, …

Moving Up The Cmmi Capability And Maturity Levels Using Simulation, David Raffo, Wayne Wakeland

Complex Systems Faculty Publications and Presentations

Process Simulation Modeling (PSIM) can be used to evaluate issues related to process strategy, process improvement, technology and tool adoption, project management and control, and process design. It is a flexible tool and can aid in quantitatively testing ideas about how to configure a process or how to configure a software acquisition supply chain (consisting of contractors and sub-contractors) that would be too expensive or too risky to construct and evaluate in any other manner.

Recent developments in PSIM tools have drastically cut the costs of developing models to evaluate process issues. Moreover, new models and more systematic and repeatable …

The Copula: A Tool For Simulating Speckle Dynamics, Donald D. Duncan, Sean J. Kirkpatrick

Electrical and Computer Engineering Faculty Publications and Presentations

Use of a copula for generating a sequence of correlated speckle patterns is introduced. The chief characteristic of this algorithm is that it generates a continuous speckle sequence with a specified evolution of the correlation and does so with just two arrays of random numbers. Thus, physically realistic temporally varying speckle patterns with proper first- and second-order statistics are easily realized. We illustrate use of the algorithm for generating sequences with prescribed Gaussian, exponential, and equal-interval correlations and demonstrate how correlation times can be specified independently. This approach to generating sequences of random realizations with prescribed correlations should prove useful …

Emergence Of Networks In Distance-Constrained Trade, Kumar Venkat, Wayne W. Wakeland

Complex Systems Faculty Publications and Presentations

Long-distance trade has been rapidly increasing in recent years. As traders from around the world exchange goods, they form networks with traders as nodes and transactions as links. We use an agent-based model of a simple artificial economy to examine the emergence of trade networks when the distance between traders matters. Distance can become an issue if fuel for transportation becomes expensive or if greenhouse gas emissions from transportation become a major concern. We model the distance constraint as a transaction cost proportional to the amount of goods traded and the distance that those goods must be transported. We find …

Using Agent Based Simulation And Game Theory Analysis To Study Information Sharing In Organizations – The Infoscape, Richard Donald Jolly, Wayne W. Wakeland

Complex Systems Faculty Publications and Presentations

Information sharing in organizations, especially the impact of sharing freely versus not sharing, was studied using game theory and agent based simulation. A game theoretic analysis was performed, and Netlogo simulations were carried out wherein some agents hoarded information while others shared information. As expected, sharing was found to greatly increase the overall amount of information within the organization. Unexpectedly, agents who share acquire more information than hoarders. This is due to the synergy that develops between groups of agents who are sharing with each other. The density of the agents is important-as the density increases, the probability increases that …

New Insights Into The Controls And Mechanisms Of Plankton Productivity Along The Us West Coast, Raphael M. Kudela, Neil S. Banas, John A. Barth, Elizabeth R. Frame, David A. Jay, John L. Largier, Evelyn J. Lessard, Tawnya D. Peterson, Andrea J. Vander Woude

Civil and Environmental Engineering Faculty Publications and Presentations

During the lifetime of the National Science Foundation's Coastal Ocean Processes program, four experiments were conducted on the US West Coast in the northern California Current System. Although each project had a unique scientific focus, all four addressed the mechanisms causing eastern boundary current systems in general, and the California Current System in particular, to be biologically rich, from phytoplankton to apex predators. Taken together, findings from these projects provide new insights into the canonical view that upwelling systems are simple wind-driven "conveyor belts," bringing cold, nutrient-rich waters to the well-lit surface ocean where biological organisms flourish. We highlight new …

Daily Forecasts Of Columbia River Plume Circulation: A Tale Of Spring/Summer Cruises, Yinglong J. Zhang, Antonio M. Baptista, Barbara M. Hickey, Byron C. Crump, David A. Jay, Michael Wilkin, Charles Seaton

Civil and Environmental Engineering Faculty Publications and Presentations

Semi-operational daily forecasts of circulation from an observatory for the Columbia River estuary-plume-shelf system routinely support oceanographic cruises, by providing 24h-ahead estimates of plume location and structure for planning purposes and for near real-time interpretation of observations. This paper analyzes forecast skill during spring/summer cruises in 2004-2007. Assessment addresses both qualitative descriptions of major plume trends and features and quantitative representation of data from (primarily) vessel-based flow-through, cast and towed systems. Forecasts emerge as robust predictors of plume location and variability, with skill that has grown over time, at least in part due to improvements in model algorithms. When the …

Seasonal Variability And Estuary-Shelf Interactions In Circulation Dynamics Of A River-Dominated Estuary, Arun Chawla, David A. Jay, Antonio M. Baptista, Michael Wilkin, Charles Seaton

Civil and Environmental Engineering Faculty Publications and Presentations

The long-term response of circulation processes to external forcing has been quantified for the Columbia River estuary using in situ data from an existing coastal observatory. Circulation patterns were determined from four Acoustic Doppler Profilers (ADP) and several conductivity-temperature sensors placed in the two main channels. Because of the very strong river discharge, baroclinic processes play a crucial role in the circulation dynamics, and the interaction of the tidal and subtidal baroclinic pressure gradients plays a major role in structuring the velocity field. The input of river flow and the resulting low-frequency flow dynamics in the two channels are quite …

Combining Climate, Crash, And Highway Data For Improved Ranking Of Speed And Winter-Weather Related Crash Locations In Oregon, Christopher M. Monsere, Peter G. Bosa, Robert L. Bertini

Civil and Environmental Engineering Faculty Publications and Presentations

In recent years, the techniques for screening transportation networks to identify high crash locations have become more sophisticated. Many transportation agencies, however, lack sufficient data, either in timeliness, completeness, or accuracy to implement many of the recent advances. This paper presents the results of an empirical analysis of screening and ranking for specific crash type (speed and ice related crashes) on rural 1.6 km (1 mi) highway sections of Oregon highways. The analysis includes data generated with the extensive use of spatial techniques and incorporates climate data to enhance environmental considerations. The paper compares the results of five ranking methods—critical …

Suspended Sediment Fluxes At An Intertidal Flat: The Shifting Influence Of Wave, Wind, Tidal, And Freshwater Forcing, Stefan A. Talke, Mark T. Stacey

Civil and Environmental Engineering Faculty Publications and Presentations

Using in situ, continuous, high frequency (8–16 Hz) measurements of velocity, suspended sediment concentration (SSC), and salinity, we investigate the factors affecting near-bed sediment flux during and after a meteorological event (cold front) on an intertidal flat in central San Francisco Bay. Hydrodynamic forcing occurs over many frequency bands including wind wave, ocean swell, seiching (500–1000 s), tidal, and infra-tidal frequencies, and varies greatly over the time scale of hours and days. Sediment fluxes occur primarily due to variations in flow and SSC at three different scales: residual (tidally averaged), tidal, and seiching. During the meteorological event, sediment fluxes are …

New Particle Formation In The Front Range Of The Colorado Rocky Mountains, Micahel Boy, Thomas Karl, Andrew Turnipseed, Roy Lee Mauldin, Edward Kosciuch, James Greenberg, Jeff Rathbone, James Smith, Andreas Held, Kelley Barsanti, Alex Guenther

Civil and Environmental Engineering Faculty Publications and Presentations

New particle formation is of interest because of its influence on the properties of aerosol population, and due to the possible contribution of newly formed particles to cloud condensation nuclei. Currently no conclusive evidence exists as to the mechanism or mechanisms of nucleation and subsequent particle growth. However, nucleation rates exhibit a clear dependence on ambient sulphuric acid concentrations and particle growth is often attributed to the condensation of organic vapours. A detailed study of new particle formation in the Front Range of the Colorado Rocky Mountains is presented here. Gas and particle measurement data for 32 days was analyzed …

Optimal Bus Stop Spacing For Minimizing Transit Operation Cost, Huan Li, Robert L. Bertini

Civil and Environmental Engineering Faculty Publications and Presentations

With the increasing attention to finance issues relative to transit operation, a bus stop spacing model is generated with the aim at minimizing the operation cost without impact on transit accessibility. Two cost functions are considered in the model including passenger access cost and in-vehicle passenger stopping cost aiming at minimizing total cost. A bus route in Portland, Oregon, USA is examined as an example using Archived Bus Dispatch System (BDS) data provided by TriMet, the regional transit provider for the Portland, Oregon metropolitan area. Based on the optimization model, the theoretical optimized bus stop spacing is 930 feet comparing …

Statistics Of Local Speckle Contrast, Donald D. Duncan, Sean J. Kirkpatrick, Ruikang K. Wang

Electrical and Computer Engineering Faculty Publications and Presentations

In describing the first-order properties of laser speckle under polarized illumination conditions, it is almost an article of faith that the contrast is unity. In many processing schemes, however, the contrast defined as the quotient of the standard deviation and the mean is calculated over a localized spatial region. In such cases, this local contrast displays a distribution of values that can depart substantially from unity. Properties of this distribution depend on details of the data acquisition and on the size of the local neighborhood over which the contrast is calculated. We demonstrate that this local contrast can be characterized …

Can Laser Speckle Flowmetry Be Made A Quantitative Tool?, Donald D. Duncan, Sean J. Kirkpatrick

Electrical and Computer Engineering Faculty Publications and Presentations

The ultimate objective of laser speckle flowmetry (and a host of specific implementations such as laser speckle contrast analysis, LASCA or LSCA; laser speckle spatial contrast analysis, LSSCA; laser speckle temporal contrast analysis, LSTCA; etc.) is to infer flow velocity from the observed speckle contrast. Despite numerous demonstrations over the past 25 years of such a qualitative relationship, no convincing quantitative relationship has been proven. One reason is a persistent mathematical error that has been propagated by a host of workers; another is a misconception about the proper autocorrelation function for ordered flow. Still another hindrance has been uncertainty in …

Monte Carlo Modeling Of Spatial Coherence: Free-Space Diffraction, Donald D. Duncan, David G. Fischer, Scott A. Prahl

Electrical and Computer Engineering Faculty Publications and Presentations

We present a Monte Carlo method for propagating partially coherent fields through complex deterministic optical systems. A Gaussian copula is used to synthesize a random source with an arbitrary spatial coherence function. Physical optics and Monte Carlo predictions of the first- and second-order statistics of the field are shown for coherent and partially coherent sources for free-space propagation, imaging using a binary Fresnel zone plate, and propagation through a limiting aperture. Excellent agreement between the physical optics and Monte Carlo predictions is demonstrated in all cases. Convergence criteria are presented for judging the quality of the Monte Carlo predictions.

Coupling The Hydrodynamic And Water Quality Model Ce-Qual-W2 With A Multi-Trophic Fish Bio-Energetics Model For Lake Roosevelt, Washington, Michael Lee Mckillip

Dissertations and Theses

Grand Coulee Dam created Franklin D. Roosevelt Lake as part of the Columbia Basin Project. Located in northeastern Washington State, the Project provides economically important hydropower (19 billion kilowatt hours per year), irrigation (225,000 ha), flood control, and sport fishing ($5 to 20 million annually). A good system understanding aids in balancing these beneficial uses for the 230 km long reservoir. The reservoir's atypical 45-day mean residence time is much shorter than a typical lake, and much longer than for a riverine dam. The spring freshet requires drawdowns of 15 to 20 m for flood control—the driving characteristic of reservoir …

What Is Rcu, Fundamentally?, Paul E. Mckenney, Jonathan Walpole

Computer Science Faculty Publications and Presentations

Read-copy update (RCU) is a synchronization mechanism that was added to the Linux kernel in October of 2002. RCU achieves scalability improvements by allowing reads to occur concurrently with updates. In contrast with conventional locking primitives that ensure mutual exclusion among concurrent threads regardless of whether they be readers or updaters, or with reader-writer locks that allow concurrent reads but not in the presence of updates, RCU supports concurrency between a single updater and multiple readers. RCU ensures that reads are coherent by maintaining multiple versions of objects and ensuring that they are not freed up until all pre-existing read-side …

The Impacts Of Congestion On Commercial Vehicle Tours Characteristics And Costs, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Congestion is a common phenomenon in all major cities of the world. Increased travel time and uncertainty brought about by congestion impacts the efficiency of logistics operations. Recent studies indicate that a significant proportion of commercial vehicle kilometers traveled (VKT) and vehicle hours traveled (VHT) are generated by trip-chains or multi-stop tours. This paper presents research demonstrating the impact of congestion on multi-stop tours in urban areas. An analytical model, numerical experiments, and real-world tour data are used to understand the impact of congestion on tour characteristics, carriers? costs, VKT, and VHT. This research shows that travel time/distance between customer …

Analysis Of Freight Tours In A Congested Urban Area Using Disaggregated Data: Characteristics And Data Collection Challenges, Miguel Andres Figliozzi, Lynsey Kingdon, Andrea Wilkitzki

Civil and Environmental Engineering Faculty Publications and Presentations

Confidentiality issues are usually an insurmountable barrier that precludes the collection of detailed and complete freight data. However, when detailed disaggregated truck activity data is available, the analysis of commercial vehicle routes and trip chain structures can provide insightful information about urban commercial vehicle tours, travel patterns, and congestion levels. Where truck data is usually aggregated and cross-sectional, this research analyzes several months of detailed truck activity records in a congested urban area and thus contributes a level of investigation unavailable with aggregated data. To the best of the author's knowledge, there is no published research regarding the analysis of …

Passive Fathometer Processing, Peter Gerstoft, William S. Hodgkiss, Martin Siderius, Chen-Fen Huang, Chris H. Harrison

Electrical and Computer Engineering Faculty Publications and Presentations

Ocean acoustic noise can be processed efficiently to extract Green's function information between two receivers. By using noise array-processing techniques, it has been demonstrated that a passive array can be used as a fathometer [Siderius, et al., J. Acoust. Soc. Am. 120, 1315-1323 (2006)]. Here, this approach is derived in both frequency and time domains and the output corresponds to the reflection sequence. From this reflection sequence, it is possible to extract seabed layering. In the ocean waveguide, most of the energy is horizontally propagating, whereas the bottom information is contained in the vertically propagating noise. Extracting the seabed information …

Modeling Streambed Heating In Shallow Streams, Robert Leslie Annear Jr.

Dissertations and Theses

The Oregon Department of Environmental Quality is developing Total Maximum Daily Loads to address water quality concerns and threatened and endangered species habitat requirements. Approximately 940 water body segments are listed as water quality limited for temperature in Oregon. CE-QUAL-W2 Version 3 is a two-dimensional water quality and hydrodynamic model capable of modeling rivers, reservoirs and estuaries. An important aspect of modeling stream temperature is handling the short-wave solar radiation that penetrates the water surface and impacts the streambed, which can affect water temperatures under low-flow conditions. The Bull Run River-Reservoir system is a 264 km2 watershed 42 km east …

Prediction Of Traditional Chinese Medicine Diagnosis From Psychosocial Questionnaires, Scott David Mist

Dissertations and Theses

Astonishingly, most Traditional Chinese Medicine (CM) research in the West proceeds without CM diagnoses, perhaps because CM diagnosis is time consuming or not considered relevant. One way to improve the feasibility of incorporating CM diagnosis would be to prescreen participants using questionnaires. This would allow cost savings in recruitment, and balancing of treatments by CM diagnosis. Consequently, the hypothesis of this research was that pre-treatment questionnaires can predict CM diagnosis.

Baseline questionnaires from 195 participants with temporomandibular joint disorder (TMD) were examined to test the hypothesis. Two methods, logistic regression (LR) and reconstructability analysis (RA), were used in conjunction to …

Ultra Reliable Computing Systems, Chong Ho Lee

Dissertations and Theses

For high security and safety applications as well as general purpose applications, it is necessary to have ultra reliable computing systems. This dissertation describes our system of self-testable and self-repairable digital devices, especially, EPLDs (Electrically Programmable Logic Devices). In addition to significantly improving the reliability of digital systems, our self-healing and re-configurable system design with added repair capability can also provide higher yields, lower testing costs, and faster time-to-market for the semiconductor industry.

The digital system in our approach is composed of blocks, which realize combinational and sequential circuits using GALs (Generic Array Logic Devices). We describe three techniques for …

A Comparison Of Five Models For Estimating Clear-Sky Solar Radiation, Robert Leslie Annear, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

Many agencies in the USA are developing management approaches to address water quality concerns and threatened and endangered species habitat requirements in water bodies. Many of these water bodies are water quality limited for temperature. Factors influencing stream temperature include: streamside vegetation, topographic shading, inflows and outflows, stream width, stream depth, light extinction and solar radiation. One of the key driving factors in estimating a water body heat budget is calculating the amount of solar radiation incident on the water surface. Even though it is preferable to measure clear-sky solar radiation, many temperature models rely on theoretical estimates of clear-sky …

The Urban Heat Island Mitigation Impact Screening Tool (Mist), David J. Sailor, Nikolaas Dietsch

Mechanical and Materials Engineering Faculty Publications and Presentations

A web-based software tool has been developed to assist urban planners and air quality management officials in assessing the potential of urban heat island mitigation strategies to affect the urban climate, air quality, and energy consumption within their cities. The user of the tool can select from over 170 US cities for which to conduct the analysis, and can specify city-wide changes in surface reflectivity and/or vegetative cover. The Mitigation Impact Screening Tool (MIST) then extrapolates results from a suite of simulations for 20 cities to estimate air temperature changes associated with the specified changes in surface characteristics for the …

Terahertz Scattering From Granular Material, Lisa M. Zurk, Brian Orlowski, Dale P. Winebrenner, Eric I. Thorsos, Megan R. Leahy-Hoppa, L. Michael Hayden

Electrical and Computer Engineering Faculty Publications and Presentations

Terahertz (THz) imaging is emerging as a potentially powerful method of detecting explosive devices, even in the presence of occluding materials. However, the characteristic spectral signatures of pure explosive materials may be altered or obscured by electromagnetic scattering caused by their granular nature. This paper presents THz transmission measurements of granular systems representative of explosives and presents results from dense media theory that accurately explain the observed scattering response.

Particle Shape As Revealed By Spectral Depolarization, Donald D. Duncan, Michael Eugene Thomas

Electrical and Computer Engineering Faculty Publications and Presentations

Through a series of numerical simulations we explore some scatter effects due to nonspherical particles. Specifically, we examine the link between the aspect ratio of randomly oriented, prolate spheroidal particles and the resulting linear depolarization of the scattered light in the forward and backscatter directions. The particular objective is to detect the presence of randomly oriented particles that have a systematic size and aspect ratio. Calculations show that the spectral behavior of the linear depolarization reveals the aspect ratio of the scattering particles. The concept is demonstrated using the size, shape, and refractive index of the spore form of Bacillus …

Using Reconstructability Analysis For Input Variable Reduction: A Business Example, Stephen Shervais, Martin Zwick

Complex Systems Faculty Publications and Presentations

We demonstrate the use of reconstructability analysis (RA) on the UCI Australian Credit dataset to reduce the number of input variables for two different analysis tools. Using 14 variables, an artificial neural net (NN) is able to predict whether or not credit was granted, with a 79.1% success rate. RA preprocessing allows us to reduce the number of independent variables from 14 to two different sets of three, which have success rates of 77.2% and 76.9% respectively. The difference between these rates and that of the 14-variable NN is not statistically significant. The three-variable rulesets given by RA achieve success …