Engineering Commons^™

Toward A Spatial-Temporal Measure Of Land-Use Mix, Steven R. Gehrke, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Urban planning and public-health research has long been interested in the connection between land-use mix and travel. Interest from urban planners stems from the potential of transportation efficiency gains achieved by an increased land-use mix and subsequent shortening of trip lengths; whereas, public-health research advocates an increased land-use mix as an effective policy for facilitating greater physical activity. Yet, despite the transportation, land-use, and health benefits related to improving land-use mix and the extent of topical attention given by researchers, no consensus has been reached regarding the magnitude of its effect on travel. This absence of agreement may largely be …

Bridge Seismic Retrofit Measures Considering Subduction Zone Earthquakes, Peter Dusicka, Ramiro Bazaez, Sarah Knoles

Civil and Environmental Engineering Faculty Publications and Presentations

Over the years, earthquakes have exposed the vulnerability of reinforced concrete structures under seismic loads. The recent occurrence of highly devastating earthquakes near instrumented regions, e.g. 2010 Maule, Chile and 2011 Tohoku, Japan, has demonstrated the catastrophic impact of such natural force upon reinforced concrete structures. Research was conducted to investigate the effect of subduction zone earthquakes on structural damage. The study suggests that large magnitude ground motions of long duration have the potential of significantly increasing the number of inelastic excursions and consequently incur more extensive structural damage as compared to ground motions with similar elastic spectral demands but …

Hierarchical Composition Of Memristive Networks For Real-Time Computing, Jens Bürger, Alireza Goudarzi, Darko Stefanovic, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

Advances in materials science have led to physical instantiations of self-assembled networks of memristive devices and demonstrations of their computational capability through reservoir computing. Reservoir computing is an approach that takes advantage of collective system dynamics for real-time computing. A dynamical system, called a reservoir, is excited with a time-varying signal and observations of its states are used to reconstruct a desired output signal. However, such a monolithic assembly limits the computational power due to signal interdependency and the resulting correlated readouts. Here, we introduce an approach that hierarchically composes a set of interconnected memristive networks into a larger reservoir. …

Enhancing Freshman Engineering Instruction With In-Class Interaction Systems And E-Books, Branimir Pejcinovic, Phillip K. Wong

Electrical and Computer Engineering Faculty Publications and Presentations

Electrical engineering students in our department take a year-long series of courses which introduces electrical engineering as a discipline and provides good grounding in engineering problem solving and programing. We have recently attempted to make the second course in the sequence more engaging by applying active learning techniques, including assigned reading and exercises prior to lectures, in-class exercises using a classroom interaction system, and programming exercises during lectures. Our results are mixed: while we think that students have learned more than if we had not used these techniques, we have not completely won over our students. While using an e-book …

Development And Uses Of Iterative Systematic Literature Reviews In Electrical Engineering Education, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

It is expected that most, if not all, graduate students will posses skills necessary for doing literature reviews. It is less clear how to teach these skills most effectively especially to students who are area novices and unfamiliar with review process. Systematic literature reviews offer a solid instructional framework which can be implemented across curriculum and offer an opportunity to teach course material differently so that student learn not just the literature review technique itself but also some segment of the course material. Our pilot study investigated issues related to practical implementation of systematic literature reviews in two classes, with …

On The Assessment Of Reliability In Probabilistic Hydrometeorological Event Forecasting, Caleb Matthew Dechant, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Probabilistic forecasts are commonly used to communicate uncertainty in the occurrence of hydrometeorological events. Although probabilistic forecasting is common, conventional methods for assessing the reliability of these forecasts are approximate. Among the most common methods for assessing reliability, the decomposed Brier Score and Reliability Diagram treat an observed string of events as samples from multiple Binomial distributions, but this is an approximation of the forecast reliability, leading to unnecessary loss of information. This article suggests testing the hypothesis of reliability via the Poisson-Binomial distribution, which is a generalized solution to the Binomial distribution, providing a more accurate model of the …

Seismic Retrofit Benefit Considering Statewide Transportation Assessment, Selamawit Tesfayesus Mehary, Peter Dusicka

Civil and Environmental Engineering Faculty Publications and Presentations

The purpose of this study was to identify and demonstrate a methodology to prioritize bridges for retrofit in the State of Oregon. Given the limited resources available, retrofitting all vulnerable bridges in the foreseeable future would not be practical. Instead, a retrofit strategy needs to be developed to prioritize the inventory and enumerate the retrofit cost. In this study, a prioritization methodology used a holistic assessment of overall roadway system to consider highway route segments, rather than individual bridges. The overall assessment was based on a cost-benefit analysis including retrofit cost, expected economic loss (with or without retrofit) and social …

Using Systematic Literature Reviews To Enhance Student Learning, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

Literature review is a skill assumed to be in the arsenal of all graduate students pursuing thesis options at the MS or PhD level. There are many resources on writing literature reviews, from campus writing centers to books such as Machi and McEvoy. One would also assume that this is among the very first tasks that research-oriented students would undertake. However, our brief and preliminary survey of graduate students in our electrical and computer engineering department showed that they have very little to no experience in performing literature reviews, and discussions with other faculty confirmed this observation. Unlike some other …

Teaching Matlab And C Programming In First Year Electrical Engineering Courses Using A Data Acquisition Device, Phillip Wong, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

Our industry partners often voice a complaint that our newly graduated electrical engineering (EE) students do not have sufficient programming skills. This is not a new concern. In a traditional undergraduate EE curriculum, one or two programming courses compose the entirety of the student’s training in programming. The courses may be taught by the computer science department without significant emphasis on engineering fundamentals. While the principles of computer science may be well covered, the ability to apply the knowledge to practical engineering problems is frequently lacking. To compound the problem, teaching novices the basics of programming can be very challenging …

Don't Go Chasing Big Waterfalls, William "Ike" Eisenhauer

Engineering and Technology Management Faculty Publications and Presentations

The article focuses on the importance of simpler health systems in the U.S. Topics discussed include success of simple systems as they are well-understood, improvement of simple systems by coupling them together, handling more patient cases by larger systems by the medical laboratory technicians giving complicated results and designing simple systems by health system engineers to deal with fewer problematic cases of patients with more efficacy.

Capillary Channel Flow (Ccf) Eu2-02 On The International Space Station (Iss): An Experimental Investigation Of Passive Bubble Separations In An Open Capillary Channel, Mark M. Weislogel, Andrew P. Wollman, Ryan M. Jenson, John T. Geile, John F. Tucker, Brentley M. Wiles, Andy L. Trattner, Claire Devoe, Lauren M. Sharp, Peter J. Canfield, Jörg Klatte, Michael E. Dreyer

Mechanical and Materials Engineering Faculty Publications and Presentations

It would be signicantly easier to design fluid systems for spacecraft if the fluid phases behaved similarly to those on earth. In this research an open 15:8 degree wedge-sectioned channel is employed to separate bubbles from a two-phase flow in a microgravity environment. The bubbles appear to rise in the channel and coalesce with the free surface in much the same way as would bubbles in a terrestrial environment, only the combined effects of surface tension, wetting, and conduit geometry replace the role of buoyancy. The host liquid is drawn along the channel by a pump and noncondensible gas bubbles …

River-Tide Dynamics: Exploration Of Nonstationary And Nonlinear Tidal Behavior In The Yangtze River Estuary, Leicheng Guo, Mick Van Der Wegen, David A. Jay, Pascal Matte, Zheng Bing Wang, Dano Roelvink, Qing He

Civil and Environmental Engineering Faculty Publications and Presentations

River-tide dynamics remain poorly understood, in part because conventional harmonic analysis (HA) does not cope effectively with nonstationary signals. To explore nonstationary behavior of river tides and the modulation effects of river discharge, this work analyzes tidal signals in the Yangtze River estuary using both HA in a nonstationary mode and continuous wavelet transforms (CWT). The Yangtze is an excellent natural laboratory to analyze river tides because of its high and variable flow, its length, and the fact that there are do dams or reflecting barriers within the tidal part of the system. Analysis of tidal frequencies by CWT and …

Development Of A Pedestrian Demand Estimation Tool: A Destination Choice Model, Christopher D. Muhs, Kelly Clifton, Patrick Allen Singleton, Robert J. Schneider

Civil and Environmental Engineering Faculty Publications and Presentations

There is growing support for improvements to the quality of the walking environment, including more investments to promote pedestrian travel. Planners, engineers, and others seek improved tools to estimate pedestrian demand that are sensitive to environmental and demographic factors at the appropriate scale in order to aid policy-relevant issues like air quality, public health, and smart allocation of infrastructure and other resources. Further, in the travel demand forecasting realm, tools of this kind are difficult to implement due to the use of spatial scales of analysis that are oriented towards motorized modes, vast data requirements, and computer processing limitations.

To …

Naturalized Communication And Testing, Marly Roncken, Swetha Mettala Gilla, Hoon Park, Navaneeth Prasannakumar Jamadagni, Christopher Cowan, Ivan Sutherland

Computer Science Faculty Publications and Presentations

We ”naturalize” the handshake communication links of a self-timed system by assigning the capabilities of filling and draining a link and of storing its full or empty status to the link itself. This contrasts with assigning these capabilities to the joints, the modules connected by the links, as was previously done. Under naturalized communication, the differences between Micropipeline, GasP, Mousetrap, and Click circuits are seen only in the links — the joints become identical; past, present, and future link and joint designs become interchangeable. We also “naturalize” the actions of a self-timed system, giving actions status equal to states — …

Hiding Private Locations By Anonymizing Data, Kelly J. Clifton, Steven R. Gehrke

TREC Project Briefs

Researchers explore ways of masking private locations in the interest of making useful data publicly available.

Managing The Economic Constraints Of Foundries And Fabless Enterprises, Charles M. Weber, Jiting Yang

Engineering and Technology Management Faculty Publications and Presentations

This paper presents an empirically grounded model, which links organizational learning to pattern-specific fixed costs. The approach described in this paper helps fab managers make fundamental strategic decisions concerning product design and product mix by engaging in scenario planning. Four critical aspects of managing pattern-specific fixed cost are analyzed in detail – sensitivity to time, design cost and production volume; platform designs; process postponement solutions; and design penalties. The model suggests that fabless enterprises and foundries must collaborate extensively on the design and realizations of product platforms for state-of-the-art integrated circuit products to remain economically viable.

Micro-Policies: Formally Verified, Tag-Based Security Monitors, Arthur Azevedo De Amorim, Maxime Denes, Nick Giannarakis, Cătălin Hriţcu, Benjamin C. Pierce, Antal Spector-Zabusky, Andrew Tolmach

Computer Science Faculty Publications and Presentations

Recent advances in hardware design have demonstrated mechanisms allowing a wide range of low-level security policies (or micro-policies) to be expressed using rules on metadata tags. We propose a methodology for defining and reasoning about such tag-based reference monitors in terms of a high-level “symbolic machine,” and we use this methodology to define and formally verify micro-policies for dynamic sealing, compartmentalization, control-flow integrity, and memory safety; in addition, we show how to use the tagging mechanism to protect its own integrity. For each micro-policy, we prove by refinement that the symbolic machine instantiated with the policy’s rules embodies a high-level …

Flavour Chemicals In Electronic Cigarette Fluids, Peyton A. Tierney, Clarissa D. Karpinski, Jessica E. Brown, Wentai Luo, James F. Pankow

Chemistry Faculty Publications and Presentations

Background: Most e-cigarette liquids contain flavour chemicals. Flavour chemicals certified as safe for ingestion by the Flavor Extracts Manufacturers Association may not be safe for use in e-cigarettes. This study identified and measured flavour chemicals in 30 e-cigarette fluids.

Methods: Two brands of single-use e-cigarettes were selected and their fluids in multiple flavour types analysed by gas chromatography/mass spectrometry. For the same flavour types, and for selected confectionary flavours (eg, bubble gum and cotton candy), also analysed were convenience samples of e-cigarette fluids in refill bottles from local ‘vape’ shops and online retailers.

Results: In many liquids, total flavour chemicals …

Aerosol Optical Hygroscopicity Measurements During The 2010 Cares Campaign, Dean B. Atkinson, James Gregory Radney, Janel Lum, Katheryn R. Kolesar, Daniel J. Cziczo, Mikhail Pekour, Qi Zhang, Ari Setyan, Alla Zelenyuk, Christopher D. Cappa

Chemistry Faculty Publications and Presentations

Measurements of the effect of water uptake on particulate light extinction or scattering made at two locations during the 2010 CARES study around Sacramento, CA are reported. The observed influence of water uptake, characterized through the dimensionless optical hygroscopicity parameter γ, is compared with calculations constrained by observed particle size distributions and size-dependent particle composition. A closure assessment has been carried out that allowed for determination of the average hygroscopic growth factors (GF) at 85% relative humidity and the dimensionless hygroscopicity parameter κ for oxygenated organic aerosol (OA) and for supermicron particles, yielding κ = 0.1–0.15 and 0.9–1.0, respectively. The …

Long-Term Metal Retention Performance Of Media Filter Drains For Stormwater Management, Agathe Thomas, Liv Haselbach, Cara Poor, Maxwell Freimund

Civil and Environmental Engineering Faculty Publications and Presentations

Stormwater runoff, a substantial source of nonpoint pollution, can be treated using Best Management Practices (BMPs), such as the Media Filter Drain (MFD). An MFD is a trench filled with an engineered media mix, usually with a grass overlay, that receives runoff from the paved roadway next to it. The MFD was shown to remove dissolved metals (zinc and copper), typical pollutants from vehicles and urban areas, which might negatively impact aquatic species in receiving waters, but its long-term effectiveness was not known. Existing media filter mixes of different ages were collected from two different sites in the Pacific Northwest …

Prussian Green: A High Rate Capacity Cathode For Potassium Ion Batteries, Prasanna Pradigi, Joseph Thiebes, Mitchell Swan, Gary Goncher, David Evans, Raj Solanki

Physics Faculty Publications and Presentations

The influence of the precursors, namely potassium ferrocyanide and potassium ferricyanide on the particles sizes of Prussian Blue (PB) and Prussian Green (PG), under identical reaction conditions have been investigated. It was found that the particle sizes influence the gravimetric capacity utilization of these materials as cathodes for aqueous potassium (K⁺ ) ion batteries. The PG particle sizes were on the order of 50-75 nm, whereas PB particles size were on the order of 2-10 microns. The PG cathodes demonstrated a reversible capacity of 121.4 mAhr/g, with a coulombic efficiency of 98.7% compared to PB cathodes which demonstrated 53.8 …

Multimodal Internal Waves Generated Over A Subcritical Ridge: Impact Of The Upper-Ocean Stratification, Xie Jieshuo, Jiayi Pan, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Interaction of barotropic tides with subsurface topography is vital to ocean mixing. Yet the behavior of large-amplitude, nonlinear, internal solitary waves (ISWs) that can cause strong mixing remains poorly understood, especially that of higher-mode and multimodal internal waves. Therefore, a 2.5-dimensional, nonhydrostatic model with adjustable vertical resolution was developed to investigate effects of upper-ocean stratification on tidally induced multimodal internal waves and to show how they are generated by the subcritical ridge where only upward-propagating internal wave beams (IWBs) are present. The effects of the stratification on properties and characteristics of the excited IWBs and on the energy partition of …

Tracking Of Rhythmical Biomedical Signals Using The Maximum A Posteriori Adaptive Marginalized Particle Filter, Sunghan Kim, Lars Andreas Holmstrom, James Mcnames

Electrical and Computer Engineering Faculty Publications and Presentations

Biomedical signals are often rhythmical and their morphologies change slowly over time. Arterial blood pressure and electrocardiogram signals are good examples with such property. It is of great interest to extract clinically useful information such as the instantaneous frequency (i.e. heart rate) and morphological changes (e.g. pulse pressure variation) from these signals. Conventional filtering methods such as the Kalman filter are not suitable for estimating the instantaneous frequency of quasiperiodic signals due to the non-Gaussian multi-modal property of its posterior distribution. One possible alternative is particle filters that are increasingly used for nonlinear systems and non-Gaussian posterior state distributions. However, …

A Two-Hydrophone Range And Bearing Localization With Performance Analysis, John Thomas Gebbie, Martin Siderius, John S. Allen Iii

Electrical and Computer Engineering Faculty Publications and Presentations

An automated, passive algorithm for detecting and localizing small boats using two hydrophones mounted on the seabed is outlined. This extends previous work by Gebbie et al. [(2013). J. Acoust. Soc. Am. 134, EL77 − EL83] in which a similar two-hydrophone approach is used to produce an ambiguity surface of likely target locations leveraging multipath analysis and knowledge of the local bathymetry. The work presented here improves upon the prior approach using particle filtering to automate detection and localization processing. A detailed analysis has also been conducted to determine the conditions and limits under which the improved approach can be …

Identification And Quantification Of Gaseous Organic Compounds Emitted From Biomass Burning Using Two-Dimensional Gas Chromatography–Time-Of-Flight Mass Spectrometry, Lindsay E. Hatch, Wentai Luo, James F. Pankow, Robert J. Yokelson, Chelsea E. Stockwell, Kelley Barsanti

Civil and Environmental Engineering Faculty Publications and Presentations

The current understanding of secondary organic aerosol (SOA) formation within biomass burning (BB) plumes is limited by the incomplete identification and quantification of the non-methane organic compounds (NMOCs) emitted from such fires. Gaseous organic compounds were collected on sorbent cartridges during laboratory burns as part of the fourth Fire Lab at Missoula Experiment (FLAME- 4) and analyzed by two-dimensional gas chromatography– time-of-flight mass spectrometry (GC × GC–ToFMS). The sensitivity and resolving power of GC × GC–ToFMS allowed the acquisition of the most extensive data set of BB NMOCs to date, with measurements for 708 positively or tentatively identified compounds. Estimated …

Semi-Modular Delay Model Revisited In Context Of Relative Timing, Hoon Park, Anping He, Marly Roncken, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

A new definition of semi-modularity to accommodate relative timing constraints in self-timed circuits is presented. While previous definitions ignore such constraints, the new definition takes them into account. The difference on a design solution for a well-known speed-independent circuit implementation of the Muller C element and a set of relative timing constraints that renders the implementation hazard free is illustrated. The old definition produces a false semi-modularity conflict that cannot exist due to the set of imposed constraints. The new definition correctly accepts the solution.

Understanding Residential Location Choices For Climate Change And Transportation Decision Making: Phase 2 Report, Kelly J. Clifton, Steven R. Gehrke, Kristina Marie Currans

Civil and Environmental Engineering Faculty Publications and Presentations

This research builds on the related Phase 1 project. In this second phase, we continue to study neighborhood and housing preferences that shape the residential location decision process. An online experimental survey tool is developed to investigate lifestyle preferences and tradeoffs that households make in their location decisions. This computer-aided experimental survey draws upon stated preference methods to engage participants in questions about residential location and transportation options. The survey infrastructure was extensively piloted (6-10% response rate). The 10-minute survey can be deployed for future investigations. This infrastructure is a contribution for the integration of visualized neighborhood typologies, or concepts, …

Modeling Regional Secondary Organic Aerosol Using The Master Chemical Mechanism, Jingyi Li, Meredith Cleveland, Luke D. Ziemba, Robert J. Griffin, Kelley Barsanti, James F. Pankow, Qi Ying

Civil and Environmental Engineering Faculty Publications and Presentations

A modified near-explicit Master Chemical Mechanism (MCM, version 3.2) with 5727 species and 16,930 reactions and an equilibrium partitioning module was incorporated into the Community Air Quality Model (CMAQ) to predict the regional concentrations of secondary organic aerosol (SOA) from volatile organic compounds (VOCs) in the eastern United States (US). In addition to the semi-volatile SOA from equilibrium partitioning, reactive surface uptake processes were used to simulate SOA formation due to isoprene epoxydiol, glyoxal and methylglyoxal. The CMAQ-MCM-SOA model was applied to simulate SOA formation during a two-week episode from August 28 to September 7, 2006. The southeastern US has …

An Admiral And Courageous Impatience, William "Ike" Eisenhauer

Engineering and Technology Management Faculty Publications and Presentations

In this article the author focuses on Hyman G. Rickover, a U.S. Navy Admiral, and his philosophy of engineering ethics. He mentions Rickover's view of the proper operation and engineering of a nuclear reactor plant, from which industrial engineers in healthcare can drew ideas to make healthcare systems reliable. Also mentioned is the book "The Rickover Effect" by Theodore Rockwell.

Static Conflict Detection For A Policy Language, Alix Trou, Robert Dockins, Andrew Tolmach

Computer Science Faculty Publications and Presentations

We present a static control flow analysis used in the Simple Unified Policy Programming Language (SUPPL) compiler to detect internally inconsistent policies. For example, an access control policy can decide to both “allow” and “deny” access for a user; such an inconsistency is called a conflict. Policies in Suppl. follow the Event-Condition-Action paradigm; predicates are used to model conditions and event handlers are written in an imperative way. The analysis is twofold; it first computes a superset of all conflicts by looking for a combination of actions in the event handlers that might violate a user-supplied definition of conflicts. SMT …