Engineering Commons^™

Oct-Based Elastography For Large And Small Deformations, Donald D. Duncan, Sean J. Kirkpatrick, Ruikang K. Wang

Electrical and Computer Engineering Faculty Publications and Presentations

We present two approaches to speckle tracking for optical coherence tomography (OCT)-based elastography, one appropriate for small speckle motions and the other for large, rapid speckle motions. Both approaches have certain advantages over traditional cross-correlation based motion algorithms. We apply our algorithms to quantifying the strain response of a mechanically inhomogeneous, bi-layered polyvinyl alcohol tissue phantom that is subjected to either small or large dynamic compressive forces while being imaged with a spectral domain OCT system. In both the small and large deformation scenarios, the algorithms performed well, clearly identifying the two mechanically disparate regions of the phantom. The stiffness …

Predicting U.S. Jet Fighter Aircraft Introductions From 1944 To 1982: A Dogfight Between Regression And Tfdea, Lane Inman, Timothy R. Anderson, Robert R. Harmon

Engineering and Technology Management Faculty Publications and Presentations

Since its inception in 2001, technology forecasting using data envelopment analysis (TFDEA) has been used with a number of applications. This paper presents a formal comparison of TFDEA to a previously published application from Technological Forecasting and Social Change by Joseph Martino. Using the data and Martino’s multiple regression model, we compare results obtained from TFDEA to those previously published. Both techniques predict the first flights of fighter jets introduced between 1960 and 1982 by using the first flights of aircraft introduced between 1944 and 1960. TFDEA was found to better predict the first flight dates than the forecast using …

Capillary-Driven Flows Along Rounded Interior Corners, Yongkang Chen, Mark M. Weislogel, Cory L. Nardin

Mechanical and Materials Engineering Faculty Publications and Presentations

The problem of low-gravity isothermal capillary flow along interior corners that are rounded is revisited analytically in this work. By careful selection of geometric length scales and through the introduction of a new geometric scaling parameter Tc, the Navier–Stokes equation is reduced to a convenient∼O(1) form for both analytic and numeric solutions for all values of corner half-angle α and corner roundedness ratio λ for perfectly wetting fluids. The scaling and analysis of the problem captures much of the intricate geometric dependence of the viscous resistance and significantly reduces the reliance on numerical data compared with several previous solution methods …

Transmission Electron Goniometry And Its Relation To Electron Tomography For Materials Science Apoplications, Peter Moeck, P. Fraundorf

Physics Faculty Publications and Presentations

Aspects of transmission electron goniometry are discussed. Combined with high resolution phase contrast transmission electron microscopy (HRTEM) and atomic resolution scanning TEM (STEM) in the atomic number contrast (Z-STEM) or the phase contrast bright field mode, transmission electron goniometry offers the opportunity to develop dedicated methods for the crystallographic characterization of nanocrystals in three dimensions. The relationship between transmission electron goniometry and electron tomography for materials science applications is briefly discussed. Internet based java applets that facilitate the application of transmission electron goniometry for cubic crystals with calibrated tilt-rotation and double-tilt specimen holders/goniometers are mentioned. The so called cubic-minimalistic tilt …

Idaho Pend Oreille River Model: Model Development And Calibration, Robert Leslie Annear, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The objectives of this project were to:

• Develop a hydrodynamic and temperature model of Pend Oreille River using CE-QUAL-W2 Version 3.2

• Calibrate the CE-QUAL-W2 model to field data collected during 2004 and 2005 using the following water quality variables:

• flow, water surface elevation, and velocity
• temperature o dissolved oxygen
• nutrients (NO3-N+NO2-N, NH4-N, PO4-P)
• algae – chlorophyll a
• BOD5 and dissolved organic matter and particulate organic matter compartments (both labile and refractory) for the organic matter cycling with algae
• periphyton

The model chosen for development was CE-QUAL-W2 Version 3.2 (Cole and Wells, 2004). This is a two-dimensional unsteady hydrodynamic …

Pend Oreille River, Box Canyon Model: Model Development And Calibration, Robert Leslie Annear, Chris Berger, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The purpose of this study was to improve the existing Version 3.0 application of CE-QUAL-W2 of the Pend Oreille River between Box Canyon Dam and Albeni Falls Dam by performing the tasks outlined above. In addition, the use of field data from 2004 as an additional calibration year would improve the confidence in the model’s predictive ability for temperature. The model simulations were run from January 1st to December 31st in each of the 3 years of model simulation: 1997, 1998 and 2004.

The model chosen for development is CE-QUAL-W2 Version 3.5 (Cole and Wells, 2006). This is a twodimensional …

Imaging The Mechanical Stiffness Of Skin Lesions By In Vivo Acousto-Optical Elastography, Sean J. Kirkpatrick, Donald D. Duncan, Ruikang K. Wang, Molly Kulesz-Martin, Ken Lee

Electrical and Computer Engineering Faculty Publications and Presentations

Optical elastography is an imaging modality that relies on variations in the local mechanical properties of biological tissues as the contrast mechanism for image formation. Skin lesions, such as melanomas and other invasive conditions, are known to alter the arrangement of collagen fibers in the skin and thus should lead to alterations in local skin mechanical properties. We report on an acousto-optical elastography (AOE) imaging modality for quantifying the mechanical behavior of skin lesions. The method relies upon stimulating the tissue with a low frequency acoustic force and imaging the resulting strains in the tissue by means of quantifying the …

Uncertainty Quantification Of Satellite Precipitation Estimation And Monte Carlo Assessment Of The Error Propagation Into Hydrologic Response, Hamid Moradkhani, Yang Hong, Soroosh Sorooshian

Civil and Environmental Engineering Faculty Publications and Presentations

The aim of this paper is to foster the development of an end-to-end uncertainty analysis framework that can quantify satellite-based precipitation estimation error characteristics and to assess the influence of the error propagation into hydrological simulation. First, the error associated with the satellite-based precipitation estimates is assumed as a nonlinear function of rainfall space-time integration scale, rain intensity, and sampling frequency. Parameters of this function are determined by using high-resolution satellite-based precipitation estimates and gauge-corrected radar rainfall data over the southwestern United States. Parameter sensitivity analysis at 16 selected 5ø ? 5ø latitude-longitude grids shows about 12?16% of variance of …

Fuzzy Cognitive Maps For Engineering And Technology Management: What Works In Practice?, Antonie J. Jetter

Engineering and Technology Management Faculty Publications and Presentations

Due to a lack of available data, many early planning decisions in engineering and technology management have to be based on experts' opinions and their qualitative statements about evolving technologies, markets and general business environments. Several authors have suggested the use of fuzzy cognitive maps (FCMs) to analytically support these decisions with simulation models that can cope with qualitative information. However, only little practice experience is documented. Based on multiple case studies and an extensive literature review, the paper reviews the state-of-the-art of FCM-practice and introduces a six-step guideline for practitioners and researchers who wish to apply FCMs to real-world …

Estimating Open-Ocean Barotropic Tidal Dissipation: The Hawaiian Ridge, Edward D. Zaron, Gary D. Egbert

Civil and Environmental Engineering Faculty Publications and Presentations

The generalized inverse of a regional model is used to estimate barotropic tidal dissipation along the Hawaiian Ridge. The model, based on the linear shallow-water equations, incorporates parameterizations for the dissipation of energy via friction in the bottom boundary layer and form drag due to internal waves generated at topographic slopes. Sea surface height data from 364 orbit cycles of the Ocean Topography Experiment (TOPEX)/Poseidon satellite mission are used to perform inversions at eight diurnal and semidiurnal tidal frequencies. It is estimated that the barotropic M2 tide loses energy at a rate of 19 GW, of which 88% is lost …

Enhancing Targeted Traffic Enforcement Efforts In Portland, Oregon, Max Coffman, Christopher Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

Enforcement is a key component of any comprehensive traffic safety program, and through a unique effort the Portland Office of Transportation (PDOT) partners with schools, the court system, community groups and the Police Bureau to develop a coordinated citywide program to improve traffic safety. However, like many government agencies, the Police Bureau faces constraints that limit the resources it can devote to traffic safety. In response, PDOT and the Police Bureau’s Traffic Division have instituted a program of Strategic and Focused Enforcement (SAFE) to better allocate limited traffic safety personnel and resources. Using historical crash data, PDOT identified 30 high …

Investigating The Impact Of Remotely Sensed Precipitation And Hydrologic Model Uncertainties On The Ensemble Streamflow Forecasting, Hamid Moradkhani, K. Hsu, Y. Hong, S. Sorooshian

Civil and Environmental Engineering Faculty Publications and Presentations

In the past few years sequential data assimilation (SDA) methods have emerged as the best possible method at hand to properly treat all sources of error in hydrological modeling. However, very few studies have actually implemented SDA methods using realistic input error models for precipitation. In this study we use particle filtering as a SDA method to propagate input errors through a conceptual hydrologic model and quantify the state, parameter and streamflow uncertainties. Recent progress in satellite-based precipitation observation techniques offers an attractive option for considering spatiotemporal variation of precipitation. Therefore, we use the PERSIANN-CCS precipitation product to propagate input …

A Comparison Of Data Assimilation Methods Using A Planetary Geostrophic Model, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

Assimilating hydrographic observations into a planetary geostrophic model is posed as a problem in control theory. The cost functional is the sum of weighted model and data residuals. Model errors are assumed to be spatially correlated, and hydrographic station data are assimilated directly. Searches in state space and data space, for minimizing the cost functional, are compared to a direct matrix inversion algorithm in the data space. State-space methods seek the minimizer of the cost functional by performing a preconditioned search in an N-dimensional space of state or control variables, where N is approximately 650 000 in the present calculations. …

Analyzing Dynamic Characteristics Of Internal Solitons Generated At The Columbia River Plume Front With Sar Images, David A. Jay, Jiayi Pan, R. D. Brodeur

Civil and Environmental Engineering Faculty Publications and Presentations

The Columbia River plume transports dissolved and particulate load, phyto- and zooplankton,and larvae across the shelf. It also facilitates primary production and influences food-web structure through its supply of silicate and micronutrients. Small-scale phenomena such as plume fronts and internal waves generated by the plume can greatly affect vertical mixing between the plume and ocean waters. Internal waves that are generated at the front of the river plume and propagate off shoreward [Nash and Moum 2005; Orton and Jay 2005] both cause mixing and transport plume water into the adjacent coastal ocean. We use Synthetic Aperture Radar (SAR) images and …

Frontal Processes In The Columbia River Plume Area, David A. Jay, Jiayi Pan, Philip M. Orton, Alexander R. Horner-Devine

Civil and Environmental Engineering Faculty Publications and Presentations

Information about frontal processes in the Columbia River plume area. Topics include: phenomenology of CR plume fronts, plume responses, upwelling fronts & internal waves: the "Zipper", etc.

Emotion-Mapped Robotic Facial Expressions Based On Philosophical Theories Of Vagueness, Phil Serchuk, Ehud Sharlin, Martin Lukac, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

As the field of robotics matures robots will need some method of displaying and modeling emotions. One way of doing this is to use a human-like face on which the robot can make facial expressions corresponding to its emotional state. Yet the connection between a robot s emotional state and its physical facial expression is not an obvious one: while a smile can gradually increase or decrease in size, there is no principled method of using boolean logic to map changes in facial expressions to changes in emotional states. We give a philosophical analysis of the problem and show that …

Engineering Education Through Service-Learning In Developing Communities: Two Case Studies, Evan A. Thomas, Andrew Azman

Mechanical and Materials Engineering Faculty Publications and Presentations

This paper provides case studies of two service learning projects that University of Colorado at Boulder (CU-Boulder) students are integrating into their academic experience. The projects focus on developing communities and are managed under the auspices of Engineers Without Borders-USA (EWB-USA), a group founded by Dr. Bernard Amadei, Professor of Civil Engineering at CU-Boulder. These projects expand students? understanding of the social value of their chosen profession, and expose them to a type of engineering significantly different than what is presented in most of their classes. Specifically, focusing on developing communities provides students with the opportunity to design solutions to …

An Agent-Based Model Of Trade With Distance-Based Transaction Cost, Kumar Venkat, Wayne W. Wakeland

Systems Science Faculty Publications and Presentations

This paper describes an application of agent-based modeling to investigate the effect of a distance-based transaction cost on trade. Long-distance trade is rapidly increasing, but may ultimately be constrained by our ability to move material goods between sellers and buyers. Unlike information exchange, trade in material goods is dependent on the price of oil and vulnerable to future scarcities of oil. In addition, there are growing concerns about greenhouse gas emissions from long-distance transportation. Our purpose in this study is to take the first step in understanding the impact of a distance constraint on free global trade using a simple …

Reproducing Published Results From In Silico Computer Models Of The Acute Inflammatory Response To Severe Sepsis, Wayne W. Wakeland, Joe Fusion, Brahm Goldstein

Systems Science Faculty Publications and Presentations

Recent studies describe computer simulation models of the acute or systemic inflammatory response (AIR or SIR) to severe sepsis, a condition that can lead to multiple organ failure and death. One study used an agent-based model, while the other used differential equations (DEs) to simulate a randomized clinical trial. Both studies obtained results similar to the actual results from a successful clinical drug trial of severe sepsis, suggesting that in silico (simulated) randomized clinical trials may be used to design more effective in vivo clinical trials.

Binary Decision Diagrams And Crisp Possibilistic Reconstructability Analysis, Martin Zwick, Alan Mishchenko

Systems Science Faculty Publications and Presentations

The paper discusses the application of Binary Decision Diagrams (BDDs) in the reconstructability analysis of crisp possibilistic systems. In particular, we show how BDDs can be used to represent set-theoretic relations and implement the three basic operations of reconstructability analysis.

Image-Based Nanocrystallography With Online Database Support, Peter Moeck, Ján Zahornadsky, Boris Dusek

Physics Faculty Publications and Presentations

The crystallographic phase and morphology of many materials change with the crystal size so that new needs arise to determine the crystallography of nanocrystals. Direct space high-resolution phase-contrast transmission electron microscopy (HRTEM) and atomic resolution scanning TEM (STEM) when combined with tools for image-based nanocrystallography in two (2D) and three (3D) dimensions possess the capacity to meet these needs. After a concise discussion of lattice-fringe visibility spheres and maps, this paper discusses lattice-fringe fingerprinting in 2D and tilt protocol applications. On-line database developments at Portland State University (PSU) that support image-based nanocrystallography are also mentioned.

Lattice Fringe Fingerprinting In Two Dimensions With Database Support, Peter Moeck, B. Seipel, R. Bjorge, P. Fraundorf

Physics Faculty Publications and Presentations

A brief introduction to lattice fringe fingerprinting in two dimensions (2D) with database support is given. The method is employed for the identification of the crystal phase of a small ensemble of nanocrystals. The enhanced viability of this method in aberration-corrected transmission electron microscopes (TEMs) and scanning TEMs (STEMs) is also illustrated.

Asymmetry Of Tidal Plume Fronts In An Eastern Boundary Current Regime, David A. Jay, Jiayi Pan, Philip M. Orton, Alexander R. Horner-Devine

Civil and Environmental Engineering Faculty Publications and Presentations

The Columbia River tidal plume or near-field is formed twice daily by the ebb outflow of the Columbia River. It is a part of a larger, anticyclonic plume bulge, which in turn is embedded in far-field plume and coastal waters. Because of the mixing caused directly and indirectly by plume fronts, the interaction of the tidal plume and bulge with the California Current upwelling regime plays a vital role in coastal productivity on the Oregon and Washington shelves. The tidal plume is initially supercritical with respect to the internal Froude number on all stronger ebbs. It is separated from the …

Hydrodynamics And Morphology In The Ems/Dollard Estuary: Review Of Models, Measurements, Scientific Literature, And The Effects Of Changing Conditions, Stefan A. Talke, Huib E. De Swart

Civil and Environmental Engineering Faculty Publications and Presentations

The Ems estuary has constantly changed over the past centuries both from man-made and natural influences. On the time scale of thousands of years, sea level rise has created the estuary and dynamically changed its boundaries. More recently, storm surges created the Dollard sub-basin in the 14th -15th centuries. Beginning in the 16th century, diking and reclamation of land has greatly altered the surface area of the Ems estuary, particularly in the Dollard. These natural and anthropogenic changes to the surface area of the Ems altered the flow patterns of water, the tidal characteristics, and the patterns of sediment deposition …