Engineering Commons^™

Alan Turing Se Fraye Un Chemin Jusqu'À La Place De L'Ordinateur, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

A brief statement on the significance, impact and future developments related to the work of computer pioneer Alan Turing, in conjunction with Turing Day, held to commemorate his 90th birthday.

*The article is in French

Creating Insanity In Learning Systems: Addressing Ambiguity Effects Of Predicting Non-Linear Continuous Valued Functions With Reconstructabilty Analysis From Large Categorically Valued Input Data Sets, William D. Eisenhauer

Systems Science Friday Noon Seminar Series

Being told to give two different, and potentially counter, responses to the same stimulus can set up a double bind in humans, leading to a type of insanity. So what how do you deal with it when it comes up quite frequently in modeling through simplification and removal of predictive variables?

In his current dissertation research Ike Eisenhauer is using reconstructability analysis to implement K-System, U-System, and B-System approaches to predict a continuously valued function through discrete categorically valued input variables [e.g. textual data]. One of the key issues is how to address the inability of K-Systems and U-Systems to …

Gain Guiding In Large-Core Bragg Fibers, Xianyu Ao, Tsing-Hua Her, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

We theoretically analyze gain guiding in large-core Bragg fibers, to be used for large-mode-area laser amplifiers with single-transverse-mode operation. The signal is gain-guided in a low-index core, whereas the pump is guided by the photonic bandgap of the Bragg cladding to achieve good confinement. The high-index layers in the Bragg cladding are half-wave thick at the signal wavelength in order to eliminate Bragg reflection, reducing the Bragg fiber effectively to a step-index fiber for gain guiding.

Computer-Aided Assessment Of Diagnostic Images For Epidemiological Research, Alison G. Abraham, Donald D. Duncan, Stephen J. Gange, Sheila West

Electrical and Computer Engineering Faculty Publications and Presentations

Background: Diagnostic images are often assessed for clinical outcomes using subjective methods, which are limited by the skill of the reviewer. Computer-aided diagnosis (CAD) algorithms that assist reviewers in their decisions concerning outcomes have been developed to increase sensitivity and specificity in the clinical setting. However, these systems have not been well utilized in research settings to improve the measurement of clinical endpoints. Reductions in bias through their use could have important implications for etiologic research. Methods: Using the example of cortical cataract detection, we developed an algorithm for assisting a reviewer in evaluating digital images for the presence and …

Effects Of Sea-Surface Conditions On Passive Fathometry And Bottom Characterization, Steven L. Means, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

Recently, a method has been developed that exploits the correlation properties of the ocean’s ambient noise to measure water depth (a passive fathometer) and seabed layering [M. Sideriuset al., J. Acoust. Soc. Am.120, 1315–1323 (2006)]. This processing is based on the cross-correlation between the surface noise and the echo return from the seabed. To quantitatively study the dependency between processing and environmental factors such as wind speed, measurements were made using a fixed hydrophone array while simultaneously characterizing the environment. The measurements were made in 2006 in the shallow waters (25m)approximately 75km off the coast of Savannah, GA. …

A Model For Sustainable Humanitarian Engineering Projects, Evan A. Thomas, Bernard Amadei, Robyn Sandekian

Mechanical and Materials Engineering Faculty Publications and Presentations

The engineering profession should embrace a new mission statement?to contribute to the building of a more sustainable, stable, and equitable world. Recently, engineering students and professionals in the United States have shown strong interest in directly addressing the needs of developing communities worldwide. That interest has taken the form of short-and medium-term international trips through Engineers Without Borders?USA and similar organizations. There are also several instances where this kind of outreach work has been integrated into engineering education at various US institutions such as the University of Colorado at Boulder. This paper addresses the challenges and opportunities associated with balancing …

Seismic Vulnerability Of Oregon State Highway Bridges: Mitigation Strategies To Reduce Major Mobility Risks, Albert Nako, Craig Shike, Jan Six, Bruce Johnson, Peter Dusicka, Selamawit Tesfayesus Mehary

Civil and Environmental Engineering Faculty Publications and Presentations

The Oregon Department of Transportation and Portland State University evaluated the seismic vulnerability of state highway bridges in western Oregon. The study used a computer program called REDARS2 that simulated the damage to bridges within a transportation network. It predicted ground motions for a specific location and magnitude of earthquake, resulting bridge damage and the cost of the damage, as well as the cost to the public for traffic delays due to detours around damaged bridges. Estimated damage and delay costs were presented for major highways in the region.

Particle Resuspension In The Columbia River Plume Near Field, Emily Y. Spahn, Alexander R. Horner-Devine, Jonathan Nash, David A. Jay, Levi Kilcher

Civil and Environmental Engineering Faculty Publications and Presentations

Measurements of suspended sediment concentration, velocity, salinity, and turbulent microscale shear in the near-field region of the Columbia River plume are used to investigate the mechanisms of sediment resuspension and entrainment into the plume. An east-west transect was occupied during spring and neap tide periods in August 2005 and May 2006, corresponding to low and high river discharge conditions, respectively. During the high-discharge period the plume is decoupled from the bottom, and fine sediment resuspended from the bottom does not leave the benthic boundary layer. The primary modes of sediment transport associated with the plume are advection of sediment from …

An Overview Of The Odot Safety Investigations Manual, Christopher M. Monsere, Karen Dixon

Civil and Environmental Engineering Faculty Publications and Presentations

This presentation provides an overview of the ODOT Safety Investigations Manual. The objective of this manual is to function as a resource that will assist ODOT traffic investigators with highway safety project screening and evaluations.

Beyond Biobricks: Synthesizing Synergistic Biochemical Systems From The Bottom-Up, Mark A. Bedau

Systems Science Friday Noon Seminar Series

Engineers who attempt to discover and optimize the behavior of complex biochemical systems face a dauntingly difficult task. This is especially true if the systems are governed by multiple qualitative and quantitative variables that have non-linear response functions and that interact synergistically. The synthetic biology community has responded to this difficulty by promoting the use of "standard biological parts" called "BioBricks", which are supposed to make biology into traditional engineering and enable engineers to "program living organisms in the same way a computer scientists can program a computer". But the BioBricks research program faces daunting hurdles, because the nonlinearity and …

Effects Of Gaussian Fields On The Stability Of Inhomogeneously Broadened Lasers, Pitak Chenkosol, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Under some conditions, spontaneous coherent pulsations are known to occur in the output beams of inhomogeneously broadened laser oscillators. These lasers typically operate with a Gaussian transverse field distribution, while the corresponding theoretical models assume a uniform-plane-wave field. The effects of a Gaussian field on the stability criteria of single-mode inhomogeneously broadened ring laser oscillators are considered in this study. It is found that in comparison to a plane wave a Gaussian field variation still permits low-threshold spontaneous pulsations but reduces the parameter space over which these pulsations can be observed.

Technical Research Needs For Sustainable Buildings: Results From A Multidisciplinary Nsf Workshop, Leidy Klotz, Vivien Loftness, Gregor Henze, David J. Sailor, David Riley

Mechanical and Materials Engineering Faculty Publications and Presentations

This article describes research needs for sustainable buildings as defined in a July 2009 National Science Foundation-sponsored workshop. This workshop brought together building researchers with researchers in the areas of distributed renewable energy and multifunctional materials to engage their expertise and identify overlapping research needs and opportunities. An overview of sustainable building design provided the broad context for discussion. This overview was followed by focused presentations in building control systems, advanced building envelopes, and systems and process integration. In addition, presentations on distributed renewable energy and multi-functional materials supported the participants in outlining and generating research needs that connect the …

A New Look At Richardson Number Mixing Schemes For Equatorial Ocean Modeling, Edward D. Zaron, James N. Moum

Civil and Environmental Engineering Faculty Publications and Presentations

A reexamination of turbulence dissipation measurements from the equatorial Pacific shows that the turbulence diffusivities are not a simple function of the gradient Richardson number. A widely used mixing scheme, the K-profile parameterization, overpredicts the turbulent vertical heat flux by roughly a factor of 4 in the stably stratified region between the surface mixed layer and the Equatorial Undercurrent (EUC). Additionally, the heat flux divergence is of the incorrect sign in the upper 80 m. An alternative class of parameterizations is examined that expresses the mixing coefficients in terms of the large-scale kinetic energy, shear, and Richardson number. These representations …

Tracking Rhythmicity In Biomedical Signals Using Sequential Monte Carlo Methods, Sungan Kim

Dissertations and Theses

Cyclical patterns are common in signals that originate from natural systems such as the human body and man-made machinery. Often these cyclical patterns are not perfectly periodic. In that case, the signals are called pseudo-periodic or quasi-periodic and can be modeled as a sum of time-varying sinusoids, whose frequencies, phases, and amplitudes change slowly over time. Each time-varying sinusoid represents an individual rhythmical component, called a partial, that can be characterized by three parameters: frequency, phase, and amplitude. Quasi-periodic signals often contain multiple partials that are harmonically related. In that case, the frequencies of other partials become exact integer multiples …

Simulation Of Insb Devices Using Drift-Diffusion Equations, Edin Sijercic

Dissertations and Theses

Silicon technology has for several decades followed Moore's law. Reduction of feature dimensions has resulted in constant increase in device density which has enabled increased functionality. Simultaneously, performance, such as circuit speed, has been improving. Recently, this trend is in jeopardy due to, for example, unsustainable increase in the processor power dissipation. In order to continue development trends, as outlined in ITRS roadmap, new approaches seem to be required once feature size reaches 10 - 20 nm range.

This research focuses on using 111-V compounds, specifically indiumantimonide (lnSb), to supplement silicon CMOS technology. Due to its low bandgap and high …

Optical Acquisition And Polar Decomposition Of The Full-Field Deformation Gradient Tensor Within A Fracture Callus, Wangdo Kim, Sean S. Kohles

Mechanical and Materials Engineering Faculty Publications and Presentations

Tracking tissue deformation is often hampered by material inhomogeneity, so local measurements tend to be insufficient thus lending to the necessity of full-field optical measurements. This study presents a novel approach to factoring heterogeneous deformation of soft and hard tissues in a fracture callus by introducing an anisotropic metric derived from the deformation gradient tensor (F). The deformation gradient tensor contains all the information available in a Green-Lagrange strain tensor, plus the rigid-body rotational components. A recent study [Bottlang et al., J. Biomech. 41(3), 2008] produced full-field strains within ovine fracture calluses acquired through the application of electronic speckle pattern …

Stability Criteria For Spontaneously Pulsing Gas Lasers, Pitak Chenkosol, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Low-threshold spontaneous pulsations are known to occur in the output beams of certain high-gain gas lasers, and good agreement between the experimental observations and numerical models has been achieved. There have also been several analytical studies of threshold criteria for spontaneously pulsing lasers. However, the analytical studies are mostly not applicable to the lasers in which the pulsations have been observed. Stability criteria for high-gain gas lasers are derived in this study, and these criteria are compared with a previously modeled gas laser instability.

Fabrication Of Anisotropic Nanostructures On Solid Substrates For Applications As Optically Active Surfaces, Mohan Krishna Vattipalli

Dissertations and Theses

Analysis of the vibrational energy levels in molecules using Raman Spectroscopy is a popular analytical method amongst today's optical technologies. Unlike fluorescence microscopy, the Raman emission doesn't undergo the process of photobleaching, which leads to short lived signal collection. The only downside with this approach is the small absorption cross-section resulting in a low intensity of the emission signal. One of the approaches used to boost this weak signal is Surface Enhanced Raman Spectroscopy (SERS). My research efforts have been focused on how to create a novel SERS substrate with aligned patterns of Au/Ag nanoparticle deposited metals of a particular …

National Urban Database And Access Portal Tool, Nudapt, Jason Ching, Michael Brown, Steven Burian, Fei Chen, Ron Cionco, Adel Hanna, Torrin Hultgren, Timothy Mcpherson, David J. Sailor, Haider Taha, David Williams

Mechanical and Materials Engineering Faculty Publications and Presentations

Based on the need for advanced treatments of high resolution urban morphological features (e.g., buildings, trees) in meteorological, dispersion, air quality and human exposure modeling systems for future urban applications, a new project was launched called the National Urban Database and Access Portal Tool (NUDAPT). NUDAPT is sponsored by the U.S. Environmental Protection Agency (USEPA) and involves collaborations and contributions from many groups including federal and state agencies and from private and academic institutions here and in other countries. It is designed to produce and provide gridded fields of urban canopy parameters for various new and advanced descriptions of model …

Developing Corridor-Level Truck Travel Time Estimates And Other Freight Performance Measures From Archived Its Data, Christopher M. Monsere, Michael Wolfe, Heba Alawakiel, Max Taylor Stephens

TREC Final Reports

The objectives of this research were to retrospectively study the feasibility for using truck transponder data to produce freight corridor performance measures (travel times) and real-time traveler information. To support this analysis, weigh-in-motion data from each of the twenty-two stations in Oregon were assembled, processed, and uploaded in the WIM data archive is housed under the Portland Transportation Archive Listing (PORTAL) umbrella at Portland State University’s Intelligent Transportation Systems Lab. Nearly 42,000,000 truck records were successful uploaded to the archive dating back to July 2005. Two separate algorithms necessary for this research were scripted, tested, and validated. The closest stations …

Gain Saturation In Gain-Guided Slab Waveguides With Large-Index Antiguiding, Tsing-Hua Her, Xianyu Ao, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

We investigate numerically and analytically the effects of gain saturation on the propagation of the fundamental mode in a gain-guided index-antiguided slab waveguide. The propagating mode adapts to gain saturation by becoming less confined, while at the same time its peak intensity increases more slowly. At steady state, both the mode shape and the power remain constant.

Determining Azimuthal Variations In Frontal Froude Number From Sar Imagery, Jiayi Pan, David A. Jay, Hui Lin

Civil and Environmental Engineering Faculty Publications and Presentations

River plume fronts are the locus of strong mixing between plume and ambient coastal waters, contribute to coastal productivity, and exert a major impact on coastal ecosystems. The frontal Froude number Fr is an important parameter characterizing the frontal status with respect to both propagation and vertical mixing. In this study, we examine azimuthal variations in Fr using a new remote sensing method. We derive Fr from SAR image data on the basis of the SAR imaging theory and the mechanism of internal wave fission at front. This method is applied to a SAR image showing a front off the …

Hardiness, Well-Being, And Health: A Meta-Analytic Summary Of Three Decades Of Research, Celina Marie Oliver

Dissertations and Theses

In recent decades, as scientific understanding regarding the effects of stress on health and well-being has grown, researchers have shown increasing interest in personal factors such as hardiness that may enhance one's ability to remain resilient under stressful conditions. Hardiness is a complex trait composed of three components (commitment, control, and challenge) that combine synergistically to increase stress tolerance. Over time, a large and complex body of research has accumulated, and while many qualitative reviews have been conducted, quantitative summaries remain rare. This study provides an empirical synthesis of research findings examining the relationships between hardiness and correlates related to …

Monte Carlo Green's Function Formalism For The Propagation Of Partially Coherent Light, Scott A. Prahl, David G. Fischer, Donald D. Duncan

Electrical and Computer Engineering Faculty Publications and Presentations

We present a Monte Carlo-derived Green's function for the propagation of partially spatially coherent fields. This Green's function, which is derived by sampling Huygens-Fresnel wavelets, can be used to propagate fields through an optical system and to compute first- and second-order field statistics directly. The concept is illustrated for a cylindrical f/1 imaging system. A Gaussian copula is used to synthesize realizations of a Gaussian Schell-model field in the pupil plane. Physical optics and Monte Carlo predictions are made for the first- and second-order statistics of the field in the vicinity of the focal plane for a variety of source …

Metamaterial Devices For The Terahertz Band, Gabriel Paul Kniffin

Center for Electron Microscopy and Nanofabrication Publications and Presentations

Terahertz (THz) and metamaterials are both hot topics in electromagnetics research. The THz band (0.1-10 THz) lies in the ‘gap’ between microwave and far infrared regions. Research is currently underway to characterize how these waves interact with matter, with potential applications including security screening, medical imaging, and non-destructive evaluation. Metamaterials are artificial materials containing sub-wavelength structures whose material properties, μ and ǫ can be ‘tuned’ to desired specifications, including simultaneously negative values, resulting in exotic properties such as a negative refractive index. Current metamaterials research includes the design of devices that operate at THz frequencies, filling a niche left wide …

Interview With Kirk Davis, Glumac International, 2009 (Audio), Kirk Davis

All Sustainability History Project Oral Histories

Interview of Kirk Davis by Jay Fielding at Glumac International, Portland, Oregon on May 22nd, 2009.

The interview index is available for download.

A Systematic Approach To Developing National Technology Policy And Strategy For Emerging Technologies, Pisek Gerdsri

Dissertations and Theses

As the pace of global competition increases, a country's competitiveness becomes of greater concern. Technology drives competitiveness and is a crucial factor for economic development in developed and developing economies. This poses a need for governments to be involved in supporting technology research and development in their countries. A government must not only provide support when an emerging technology is being considered, it should also nurture and guide its development. The effective national technology policies and strategies should go beyond merely identifying the critical technologies.

This research has developed a systematic and comprehensive approach for policy makers to strategically define …

Environmental Durability Of Reinforced Concrete Deck Girders Strengthened For Shear With Surface Bonded Carbon Fiber-Reinforced Polymer, Christopher Higgins, Matthew R. Dawson, Mikal M. Mitchell, Gautam Sopal, A. Ekin Senturk

TREC Final Reports

This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort included determining the role of freeze-thaw, moisture, and fatigue on structural performance and developing analytical design procedures that account for durability.

The results showed that moisture infiltration behind the CFRP, combined with freeze-thaw, was critical in reducing shear panel stiffness and shear capacity. Long-term moisture exposure alone produced only a minor decrease in shear capacity. Freeze-thaw, combined with fatigue, had little effect on shear capacity …

Automated Crystal Phase And Orientation Mapping Of Nanocrystals In A Transmission Electron Microscope, Peter Moeck, Sergei Rouvimov, Edgar F. Rauch, Stavros Nicolopoulos

Physics Faculty Publications and Presentations

An automated technique for the mapping of nanocrystal phases and orientations in a transmission electron microscope (TEM) is described. It is based on the projected reciprocal lattice geometry that is extracted from electron diffraction spot patterns. The required hardware allows for a scanning‐precession movement of the primary electron beam on the crystalline sample and can be interfaced to any newer or older TEM. The software that goes with this hardware is flexible in its intake of raw data so that it can also create orientation and phase maps of nanocrystal from high resolution TEM (HRTEM) images. When the nanocrystals possess …

Extended Superposed Quantum State Initialization Using Disjoint Prime Implicants, David Rosenbaum, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Extended Superposed Quantum State Initialization Using Disjoint Prime Implicants (ESQUID) is a new algorithm for generating quantum arrays for the purpose of initializing a desired quantum superposition. The quantum arrays generated by this algorithm almost always use fewer gates than other algorithms and in the worst case use the same number of gates. These improvements are achieved by allowing certain parts of the quantum superposition that cannot be initialized directly by the algorithm to be initialized using special circuits. This allows more terms in the quantum superposition to be initialized at the same time which decreases the number of gates …