Engineering Commons^™

Use Of International Hydrographic Organization Tidal Data For Improved Tidal Prediction, Songwei Qi

Dissertations and Theses

Tides are the rise and fall of water level caused by gravitational forces exerted by the sun, moon and earth. Understanding sea level variation and its impact currents is very important especially in coastal regions. With knowledge of the tide-generating force and boundary conditions, hydrodynamic models can be used to predict or model tides in coastal regions. However, these models are not sufficiently accurate, and in-situ tide gauge data may be used to improve them in coastal regions. The International Hydrographic Organization (IHO) tidal data bank consists of over 4000 tide gauge stations scattered all around the globe, most of …

Cytoskeletal Strains In Modeled Optohydrodynamically Stressed Healthy And Diseased Biological Cells, Sean S. Kohles, Yu Liang, Asit K. Saha

Mechanical and Materials Engineering Faculty Publications and Presentations

Controlled external chemomechanical stimuli have been shown to influence cellular and tissue regeneration/degeneration, especially with regards to distinct disease sequelae or health maintenance. Recently, a unique three-dimensional stress state was mathematically derived to describe the experimental stresses applied to isolated living cells suspended in an optohydrodynamic trap (optical tweezers combined with microfluidics). These formulae were previously developed in two and three dimensions from the fundamental equations describing creeping flows past a suspended sphere. The objective of the current study is to determine the full-field cellular strain response due to the applied three-dimensional stress environment through a multiphysics computational simulation. In …

Trans-Dimensional Geoacoustic Inversion Of Wind-Driven Ambient Noise, Jorge E. Quijano, Stan E. Dosso, Jan Dettmer, Lisa M. Zurk, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

This letter applies trans-dimensional Bayesian geoacoustic inversion to quantify the uncertainty due to model selection when inverting bottom-loss data derived from wind-driven ambient-noise measurements. A partition model is used to represent the seabed, in which the number of layers, their thicknesses, and acoustic parameters are unknowns to be determined from the data. Exploration of the parameter space is implemented using the Metropolis–Hastings algorithm with parallel tempering, whereas jumps between parameterizations are controlled by a reversible-jump Markov chain Monte Carlo algorithm. Sediment uncertainty profiles from inversion of simulated and experimental data are presented.

Evolution Of Ensemble Data Assimilation For Uncertainty Quantification Using The Particle Filter-Markov Chain Monte Carlo Method, Hamid Moradkhani, Caleb Matthew Dechant, Soroosh Sorooshian

Civil and Environmental Engineering Faculty Publications and Presentations

Particle filters (PFs) have become popular for assimilation of a wide range of hydrologic variables in recent years. With this increased use, it has become necessary to increase the applicability of this technique for use in complex hydrologic/land surface models and to make these methods more viable for operational probabilistic prediction. To make the PF a more suitable option in these scenarios, it is necessary to improve the reliability of these techniques. Improved reliability in the PF is achieved in this work through an improved parameter search, with the use of variable variance multipliers and Markov Chain Monte Carlo methods. …

The Impact Of Freeway Traffic Conditions On In-Vehicle Exposure To Ultrafine Particulate Matter, Miguel A. Figliozzi, Alexander Y. Bigazzi

Civil and Environmental Engineering Faculty Publications and Presentations

There is evidence of adverse health impacts from human exposure to traffic-related ultrafine particulate matter pollution. As more commuters are spending a significant portion of their daily routine inside vehicles, it is increasingly relevant to study exposure levels to harmful pollutants inside the vehicle microenvironment. This study is one of the first research efforts to combine detailed freeway traffic data (at 20 s intervals) and in-vehicle ultrafine particulate (UFP) exposure data under varying vehicle ventilation conditions. Results show that due to negative correlation between traffic speed and density, traffic states have a small but significant impact on in-vehicle UFP concentrations, …

Safety Effectiveness Of Red Light Treatments For Red Light Running, Carl Scott Olson

Dissertations and Theses

Crashes resulting from automobiles running a red light are typically severe in nature. One way to try to reduce the number and severity of these types of crashes is by increasing the red clearance interval of a traffic signal. In Portland, Oregon, eight intersections received a variety of treatments including red extensions. Determining which treatment had what effect can be difficult to weed out. Using a combination of crash analysis and a model simulating an intersection with red extensions, this paper describes the estimated impact of red light running intersection upgrades and red extensions on crashes. By performing a variety …

Experimental Tests And Numerical Analyses Of Steel Truss Bridge Gusset Connections, Christopher Higgins, Peter Dusicka, Michael Scott

TREC Final Reports

The collapse of the I-35W Bridge in Minneapolis, Minnesota has raised questions regarding the performance and possibly safety of steel truss bridges. The failure investigation indicated that the collapse was due to a design error in the gusset plates used to connect the truss members. The findings also recommend that evaluation of truss connections will be needed, which is a deviation from past practice where only members were considered. Gusset plates connect individual steel truss bridge members together at a node. In 10% of the 200,000 steel bridges in US in 2008, failure of a single truss or connection could …

Analysis Of Travel Time Reliability For Freight Corridors Connecting The Pacific Northwest, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

A new methodology and algorithms were developed to combine diverse data sources and to estimate the impacts of recurrent and non-recurrent congestion on freight movements’ reliability and delays, costs, and emissions. The results suggest that traditional traffic sensor data tend to underestimate the impacts of congestion on commercial vehicles travel times and variability. This research also shows that congestion is not only detrimental for carriers and shippers costs but also for the planet due to major increases in GHG emissions and for the local community due to large increases in NOx, PM, and other harmful pollutants.

The methodologies developed throughout …

Contextual Influences On Trip Generation, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs

Civil and Environmental Engineering Faculty Publications and Presentations

There is national interest in building data that expands upon the existing Institute of Transportation Engineers (ITE) trip generation rates to include sites located in a multi-modal context. Current ITE rates represent travel behavior for development in single lots and uses, primarily measured in low-density suburban areas. Despite evidence that a more compact urban form, access to transit and a greater mix of uses generates fewer and shorter vehicle trips, local governments are often compelled to use current ITE trip generation rates to evaluate transportation impacts and calculate transportation system development charges (TSDCs). This is due to: a) the expense …

Thiol Reactive Probes And Chemosensors, Robert M. Strongin, Lovemore Hakuna, Hanjing Peng, Weixuan Chen, Yunfeng Cheng, Binghe Wang

Chemistry Faculty Publications and Presentations

Thiols are important molecules in the environment and in biological processes. Cysteine (Cys), homocysteine (Hcy), glutathione (GSH) and hydrogen sulfide (H2S) play critical roles in a variety of physiological and pathological processes. The selective detection of thiols using reaction-based probes and sensors is very important in basic research and in disease diagnosis. This review focuses on the design of fluorescent and colorimetric probes and sensors for thiol detection. Thiol detection methods include probes and labeling agents based on nucleophilic addition and substitution, Michael addition, disulfide bond or Se-N bond cleavage, metal-sulfur interactions and more. Probes for H2S are based on …

Dynamics Capabilities, Caroline Mudavadi, Farshad Madani, Garrett Gilliland, Corey White

Engineering and Technology Management Student Projects

Slides from a presentation based on Teece, D. J. (January 01, 2007). Explicating dynamic capabilities: the nature and microfoundations of (sustainable) enterprise performance. Strategic Management Journal, 28, 13, 1319.

Discusses capabilities that enable business enterprises to create, deploy, and protect the intangible assets that support superior long-run business performance.

Experimental Validation Of Phase Using Nomarski Microscopy With An Extended Fried Algorithm, Scott A. Prahl, Amanda Dayton, Kyle Juedes, Erik J. Sánchez, Rafael Paez López, Donald D. Duncan

Electrical and Computer Engineering Faculty Publications and Presentations

Reconstruction of an image (or shape or wavefront) from measurements of the derivatives of the image in two orthogonal directions is a common problem. We demonstrate how a particular reconstructor, commonly referred to as the Fried algorithm, can be used with megapixel derivative images to recover the original image. Large datasets are handled by breaking the derivative images into smaller tiles, applying the Fried algorithm and stitching the tiles back together. The performance of the algorithm is demonstrated using differential interference contrast microscopy on a known test object.

Aspect-Dependent Radiated Noise Analysis Of An Underway Autonomous Underwater Vehicle, John Gebbie, Martin Siderius, John S. Allen Iii

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents an analysis of the acoustic emissions emitted by an underway REMUS-100 autonomous underwater vehicle(AUV) that were obtained near Honolulu Harbor, HI using a fixed, bottom-mounted horizontal line array (HLA). Spectral analysis,beamforming, and cross-correlation facilitate identification of independent sources of noise originating from the AUV. Fusion of navigational records from the AUV with acoustic data from the HLA allows for an aspect-dependent presentation of calculated source levels of the strongest propulsion tone.

Leveraging Carbon Financing To Enable Accountable Water Treatment Programs, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

This article outlines the technical premise and policy considerations surrounding the first program to generate carbon finance for drinking water treatment.

Value Of Travel Time Reliability Part Ii: A Study Of Tradeoffs Between Travel Reliability, Congestion Mitigation Strategies And Emissions, Miguel A. Figliozzi, Alexander Y. Bigazzi

Civil and Environmental Engineering Faculty Publications and Presentations

Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissions; the net effect of mitigation depends on the balance of induced travel demand and increased vehicle efficiency that in turn depend on the pollutant, congestion level, and fleet composition. In the long run, capacity-based congestion improvements within certain speed intervals can reasonably be expected to increase emissions of CO2e, CO, and NOx through increased vehicle travel volume. Better opportunities for emissions reductions exist for HC and …

Forecast Of Wireless Communication Technology: A Comparative Study Of Regression And Tfdea Model, Dong-Joon Lim, Timothy R. Anderson, Jisun Kim

Engineering and Technology Management Faculty Publications and Presentations

This study presents a formal comparison of TFDEA with regression model to forecast wireless communication technology. In addition to the data set from the former research, up-to-2011 4G network technologies are added and analyzed. The research was designed to set the point of forecasting in 2001 so that technologies between 2001 and 2011 are to be forecasted using data set between 1979 and 2001. The results from both TFDEA and regression model are compared and discussed. This comparative study can provide forecasters with different aspects between 'best-practice measurement' and 'average practice measurement' and, ultimately, help to select the suitable approach …

A Mean Curvature Model For Capillary Flows In Asymmetric Containers And Conduits, Yongkang Chen, Noël Tavan, Mark M. Weislogel

Mechanical and Materials Engineering Faculty Publications and Presentations

Capillarity-driven flows resulting from critical geometric wetting criterion are observed to yield significant shifts of the bulk fluid from one side of the container to the other during "zero gravity" experiments. For wetting fluids, such bulk shift flows consist of advancing and receding menisci sometimes separated by secondary capillary flows such as rivulet-like flows along gaps. Here we study the mean curvature of an advancing meniscus in hopes of approximating a critical boundary condition for fluid dynamics solutions. It is found that the bulk shift flows behave as if the bulk menisci are either “connected” or "disconnected." For the connected …

Measuring Sustainability, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

The World Health Organization estimates that 884 million people do not have access to safe sources of drinking water. Meanwhile, about half of the world's population continues to use unsustainable, biomassbased energy sources for indoor fuel, leading to extensive deforestation, harmful indoor air emissions, and in many cases upper respiratory disease and high commodity costs for impoverished families. Exacerbating these problems are the international effects of climate change, expected to significantly impact developing countries by changing water and energy quality and availability. International development organizations work tirelessly to address these challenges. However, many efforts struggle with achieving long-term sustainability; many …

Operational Guidance For Bicycle-Specific Traffic Signals In The United States, Christopher Monsere, Miguel A. Figliozzi, Sam Thompson, Kirk Paulsen

Civil and Environmental Engineering Faculty Publications and Presentations

The research consisted of two phases: 1) a synthesis of practice and 2) and analysis of cyclist performance characteristics. The synthesis of current practice reviewed the literature, current engineering design and operational guidance documents, and surveyed the jurisdictions about their current deployments of bicyclespecific signals. This report summarizes research of cyclist behavior at signalized intersections in Portland, Eugene, Corvallis, Beaverton and Clackamas County, OR. These signals had both bicycle-specific indications and vehicle-only signals. A total of 4,673cyclists were observed. For each cyclist observed arriving on red, a set of descriptive variables were collected (e.g., age, sex, helmet use, presence of …

Using System Dynamics To Contribute To Ecological Economics, Takuro Uehara, Yoko Nagase, Wayne W. Wakeland

Wayne W. Wakeland

This paper demonstrates the usefulness of the system dynamics approach to the development of ecological economics, the study of the interactions between economic systems and ecological systems. We build and analyze an ecological economic model: an extension of a population–resource dynamics model developed by Brander and Taylor and published in American Economic Review in 1998. The focus of the present paper is on the model building and analysis to contribute to theory building rather than eliciting policy implications from the model. Hence, this is an example of model-based theory building using system dynamics. Our analysis sheds light on several problems …

Laboratory Performance Of Highway Bridge Girder Anchorages Under Simulated Hurricane-Induced Wave Loading, Jora Lehrman, Christopher Higgins, Daniel Cox

TREC Final Reports

Many bridges along the Gulf Coast of the United States were damaged by recent hurricanes, and many more are susceptible to similar damage. This research examines the structural performance of common connection details used to anchor prestressed concrete girders to the substructure. Full-scale specimens were fabricated and tested under static and dynamic cyclic load histories. Dynamic load histories were developed from previously conducted hydraulic tests of a 1/5 scale model of a highway bridge under hurricane wave loads. The load effects considered included the pseudo-statically applied vertical uplift force, horizontal force, combined horizontal and vertical forces, and dynamically applied combined …

Using System Dynamics To Contribute To Ecological Economics, Takuro Uehara, Yoko Nagase, Wayne Wakeland

Systems Science Faculty Publications and Presentations

This paper demonstrates the usefulness of the system dynamics approach to the development of ecological economics, the study of the interactions between economic systems and ecological systems. We build and analyze an ecological economic model: an extension of a population–resource dynamics model developed by Brander and Taylor and published in American Economic Review in 1998. The focus of the present paper is on the model building and analysis to contribute to theory building rather than eliciting policy implications from the model. Hence, this is an example of model-based theory building using system dynamics. Our analysis sheds light on several problems …

Case Study: The Optimization Of Information Flow & Organization In Software Development, Farshad Madani, Bing Wang, Xiaowen Wang, Corey White, Liying Wang

Engineering and Technology Management Student Projects

Trial and error are inevitable in the process of software development; the redesign is wasteful when unfocused communication occurs within the development process. To speed up this development process, we optimized the information flow and redesigned the development organization into chunks. First, we investigated the information flow between tasks and coupled tasks into phases utilizing the Design Structure Matrix (DSM) so that the information exchange among chunks of tasks is as few as possible. In this way, the redundant iterations of tasks are eliminated. Meanwhile, we also grouped the engineers into groups according to the tasks, in this; we eliminated …

A Study Of Headway Maintenance For Bus Routes: Causes And Effects Of “Bus Bunching” In Extensive And Congested Service Areas, Miguel A. Figliozzi, Wu-Chi Feng, Gerardo Lafferriere, Wei Feng

Civil and Environmental Engineering Faculty Publications and Presentations

A healthy and efficient public transit system is indispensable to reduce congestion, emissions, energy consumption, and car dependency in urban areas. The objective of this research is to 1) develop methods to evaluate and visualize bus service reliability for transit agencies in various temporal and spatial aggregation levels; 2) identify the recurrent unreliability trends of bus routes (focusing on high-frequency service periods) and understand their characteristics, causes and effects; and 3) model service times using linear regression models.

This research utilized six months of archived automatic vehicle location (AVL) and automatic passenger count (APC) data from a low-performance route (Route …

Analyzing And Quantifying The Impact Of Congestion On Ltl Industry Costs And Performance In The Portland Metropolitan Region, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Increased congestion during peak morning and afternoon periods in urban areas is increasing logistics costs. In addition, environmental, social, and political pressures to limit the impacts associated with CO2 emissions are mounting rapidly. A key challenge for transportation agencies and businesses is to improve the efficiency of urban freight and commercial vehicle movements while ensuring environmental quality, livable communities, and economic growth. However, research and policy efforts to analyze and quantify the impacts of congestion and freight public policies on carriers operations and CO2 emissions are hindered by the complexities of vehicle routing problems with time-dependent travel times and the …

Capillarity-Driven Droplet Ejection, Andrew Paul Wollman

Dissertations and Theses

Drop Towers provide brief terrestrial access to microgravity environments. When used for capillary fluidics research, a drop tower allows for unique control over an experiment's initial conditions, which enables, enhances, or otherwise improves the study of capillary phenomena at significantly larger length scales than can normally be achieved on the ground. This thesis provides a historical context for the introduction of a new, highly accessible, 2.1s tower design used for capillary research and presents a variety of demonstrative experimental results for purely capillarity-driven flows leading to bubble ingestion, sinking flows, multiphase flows, and droplet ejections. The focus of this thesis …

Bus Fleet Type And Age Replacement Optimization: A Case Study Utilizing King County Metro Fleet Data, Wei Feng, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Bus fleet data have consistently shown that vehicle operating and maintenance costs increase as vehicles age. A fleet manager has to deal with the tradeoff between the lower operating and maintenance costs of newer fleets and their higher initial capital costs as well as the tradeoff between conventional and fuel efficient bus technologies. This study formulates and implements a fleet replacement optimization framework that is applied to a case study that compares two bus types: a conventional diesel and a hybrid bus. Employing real-world bus fleet data from King County Metro (Washington State, USA) multiple scenarios are examined to account …

Regional Models Of Internal Tides, Glenn S. Carter, Oliver B. Fringer, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

Internal tides are ubiquitous in the ocean, and they play an important role in a range of ocean processes, for example, particle dispersal, acoustics, and vertical buoyancy flux. The wavelength of internal tides can be as much as 250 km in the open ocean, but as the generation of these tides depends on the angle between the depth-averaged current and the topography, there can be considerable local spatial variability. This range of scales makes it difficult to develop a comprehensive understanding of the processes involved from observations alone. Regional numerical modeling provides a way to study the generation and early …

Seismic Hazard Assessment Of Oregon Highway Truck Routes, Peter Dusicka, Selamawit Tesfayesus Mehary

TREC Final Reports

This research project developed a seismic risk assessment model along the major truck routes in Oregon. The study had adopted federally developed software tools called Risk for Earthquake Damage to Roadway Systems (REDARS2) and HAZUS-MH. The model was the first time REDARS2 has been adopted and used in research outside of the original development team, presenting a number of unique challenges. The development of the model was a complex, intensive process that required a significant research effort, manipulation and adjustment of data. Furthermore, limitations of the software tools themselves had been identified that prevented the inclusion of important aspects such …

An Empirical Study Of Particulate Matter Exposure For Passengers Waiting At Bus Stop Shelters In Portland, Oregon, Usa, Adam Moore, Miguel A. Figliozzi, Christopher Michael Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

Current guidelines for the location and design of bus stops do not take into account air quality or exposure considerations for waiting passengers. This paper compares the exposure of transit riders waiting at three-sided bus stop shelters that either: 1) face roadway traffic, or 2) face away from roadway traffic. Shelters were instrumented with devices to monitor particulate matter concentration inside and outside the shelter, wind speed and direction, and vehicle counts. Data were collected at three shelters during both the morning and afternoon peak periods. Bus shelter orientation is found to have a significant effect on the concentration of …