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Articles 1 - 30 of 1574

Full-Text Articles in Engineering

Teen Driver System Modeling: A Tool For Policy Analysis, Celestin Missikpode, Corrine Peek-Asa, Daniel V. Mcgehee, James Torner, Wayne Wakeland, Robert Wallace Dec 2018

Teen Driver System Modeling: A Tool For Policy Analysis, Celestin Missikpode, Corrine Peek-Asa, Daniel V. Mcgehee, James Torner, Wayne Wakeland, Robert Wallace

Systems Science Faculty Publications and Presentations

Background: Motor vehicle crashes remain the leading cause of teen deaths in spite of preventive efforts. Prevention strategies could be advanced through new analytic approaches that allow us to better conceptualize the complex processes underlying teen crash risk. This may help policymakers design appropriate interventions and evaluate their impacts.

Methods: System Dynamics methodology was used as a new way of representing factors involved in the underlying process of teen crash risk. Systems dynamics modeling is relatively new to public health analytics and is a promising tool to examine relative influence of multiple interacting factors in predicting a health outcome. Dynamics ...


The Influence Of Shared Mobility And Transportation Policies On Vehicle Ownership, Edgar Bertini Ruas Nov 2018

The Influence Of Shared Mobility And Transportation Policies On Vehicle Ownership, Edgar Bertini Ruas

TREC Friday Seminar Series

With the emergence of several new providers of shared mobility services, such as Uber, Biketown and Car2go, there has been the promise of changes to the traditional way of owning and using a vehicle. One potential consequence of the new mobility services is the reduction in vehicle ownership. At the same time, cities are trying to anticipate these changes by reducing the amount of space dedicated to parking. This thesis aims to asses the extent to which new shared mobility and transportation policy strategies (especially parking requirements and transit pass availability) relate to vehicle ownership among residents of multifamily dwellings ...


Webinar: Segmenting The Market For Transportation Demand Management Campaigns, Philip L. Winters, Amy Lester Nov 2018

Webinar: Segmenting The Market For Transportation Demand Management Campaigns, Philip L. Winters, Amy Lester

TREC Webinar Series

Social marketing seeks to develop and integrate marketing concepts with other approaches to influence behaviors that benefit individuals and communities for the greater social good. It is a useful transportation demand management (TDM) planning approach to promote travel behavior change. The purpose of this study was to explore a consumer market segmentation technique successfully used in Europe for its applicability to marketing efforts in the United States. Attitudinal and demographic data were collected from 1900 individuals in Florida, Oregon, and Virginia modeled after the European approach. Clustering analysis was applied to divide the sample into segments so that members of ...


Scenarios For Adoption Of Autonomous Vehicle Technologies In Freight, Sabya Mishra Nov 2018

Scenarios For Adoption Of Autonomous Vehicle Technologies In Freight, Sabya Mishra

TREC Friday Seminar Series

Innovation adoption research has largely ignored organizational adoption, and little work has been done to understand or predict the adoption of innovations by freight organizations. Among the existing innovation adoption theoretical and methodological approaches this seminar will explore which are most appropriate methods for freight organizational adoption. The seminar will present a disaggregate market penetration model for freight transportation organizations adopting connected autonomous vehicle (CAV) technology and demonstrate an application using a case study area in Memphis, TN. The seminar will highlight ongoing and future organizational adoption research for CAVs, and other innovations.


Driver Comprehension Of Permissive Right-Turns With A Flashing Yellow Arrow (Fya), Christopher Monsere, David Hurwitz Oct 2018

Driver Comprehension Of Permissive Right-Turns With A Flashing Yellow Arrow (Fya), Christopher Monsere, David Hurwitz

TREC Friday Seminar Series

This research explored driver comprehension and behaviors with respect to right-turn signal displays with a focus on the Flashing Yellow Arrow (FYA) in a driving simulator and a comprehension survey. Flashing yellow arrows are used in place of other turn signals, such as solid green or flashing yellow or red circles, to indicate that drivers may turn after yielding to oncoming traffic. These turns are considered “permissive.” Turns where no conflicting traffic is present, such as those indicated with a green arrow, are “protected” turns. The flashing yellow arrow’s inclusion in the 2009 Manual on Uniform Traffic Control Devices ...


Webinar: Addressing Bicycle-Vehicle Conflicts With Alternate Signal Control Strategies, Sirisha Kothuri Oct 2018

Webinar: Addressing Bicycle-Vehicle Conflicts With Alternate Signal Control Strategies, Sirisha Kothuri

TREC Webinar Series

There is nationwide interest in supporting sustainable and active transportation modes such as bicycling and walking due to the many benefits associated with them, including reduced congestion, lower emissions and improved health. Although the number of bicyclists is increasing, safety remains a top concern. In urban areas, a common crash type involving bicycles at intersections is the “right hook” where a right-turning vehicle collides with a through bicyclist. While geometric treatments and pavement markings have been studied, there is a lack of research on signal timing treatments to address right-hook bicycle-vehicle conflicts.

Addressing Bicycle-Vehicle Conflicts with Alternate Signal Control Strategies ...


Unobserved Heterogeneity And Spatial Correlation: Statistical And Econometric Analyses Of Heavy-Vehicle Hard Braking And Crash Frequency, Jason Anderson Oct 2018

Unobserved Heterogeneity And Spatial Correlation: Statistical And Econometric Analyses Of Heavy-Vehicle Hard Braking And Crash Frequency, Jason Anderson

TREC Friday Seminar Series

In heavy-vehicles (a truck with a gross vehicle weight rating of greater than 10,000 pounds), a hard braking event is described as an event that prompts the vehicle’s “black box” to record an abrupt change in speed. More specifically, this occurs when the driver applies excess force to the vehicle’s brake. These hard braking events can then serve as a proxy for several factors, such as economic impacts, environmental impacts, and impacts on safety. In the context of the present study, being that approximately one-third of all heavy-vehicle-caused crashes in 2014 were attributed to faulty brakes, there ...


Removal Efficiencies, Uptake Mechanisms And Competitive Effects Of Copper And Zinc In Various Stormwater Filter Media, Emily Heleva-Ponaski Sep 2018

Removal Efficiencies, Uptake Mechanisms And Competitive Effects Of Copper And Zinc In Various Stormwater Filter Media, Emily Heleva-Ponaski

Dissertations and Theses

Polluted stormwater, if not treated, can compromise water quality throughout our hydrologic cycle, adversely affecting aquatic ecosystems. Common stormwater pollutants, copper and zinc, have been identified as primary toxicants in multiple freshwater and marine environments. For small-scale generators, stormwater management can be cumbersome and implementation of common BMPs impractical thus catch basins are popular though not the most environmentally conscious and sustainable option. This study aims to characterize the potential of a mobile media filter operation for the treatment and on-site recycling of catch basin stormwater. The removal capacities of various commercially available filter media (e.g. a common perlite ...


Driver Distraction In Microsimulation Of A Mid-Block Pedestrian Crossing, Darryl Joseph Michaud Sep 2018

Driver Distraction In Microsimulation Of A Mid-Block Pedestrian Crossing, Darryl Joseph Michaud

Dissertations and Theses

Traffic simulation has become an invaluable part of the traffic engineering toolbox. However, the majority of driver models are designed to recreate traffic performance based on interactions among vehicles. In keeping with this pursuit, most are fundamentally built to avoid collisions. This limits the applicability of using these models for addressing safety concerns, especially those regarding pedestrian safety performance. However, by explicitly including some of the sources of human error, these limitations can, in theory, be overcome. While much work has been done toward including these human factors in simulation platforms, one key aspect of human behavior has been largely ...


Reducing Exposures Traffic-Related Air Pollution And Urban Building Design, Elliott Gall, Linda George Sep 2018

Reducing Exposures Traffic-Related Air Pollution And Urban Building Design, Elliott Gall, Linda George

Mechanical and Materials Engineering Faculty Publications and Presentations

No abstract provided.


Advancing Bridge Technology, Task 10: Statistical Analysis And Modeling Of Us Concrete Highway Bridge Deck Performance -- Internal Final Report, Omar Ghonima, Thomas Schumacher, Avinash Unnikrishnan, Adam Fleischhacker Sep 2018

Advancing Bridge Technology, Task 10: Statistical Analysis And Modeling Of Us Concrete Highway Bridge Deck Performance -- Internal Final Report, Omar Ghonima, Thomas Schumacher, Avinash Unnikrishnan, Adam Fleischhacker

Civil and Environmental Engineering Faculty Publications and Presentations

Concrete highway bridge deck repairs represent the highest expense associated with bridge maintenance cost. In order to optimize such activities and use the available monies effectively, a solid understanding of the parameters that affect the performance of concrete bridge decks is critical. The National Bridge Inventory (NBI), perhaps the single-most comprehensive source of bridge information, gathers data on more than 600,000 bridges in all fifty states, the District of Columbia, and the Commonwealth of Puerto Rico. Focusing on concrete highway bridge deck performance, this research developed a nationwide database based on NBI data and other critical parameters that were ...


Methods For Estimating Vehicle Fuel Consumption In Urban Road Networks Using Geographical Attributes, Ryan G. Conrad Aug 2018

Methods For Estimating Vehicle Fuel Consumption In Urban Road Networks Using Geographical Attributes, Ryan G. Conrad

Civil and Environmental Engineering Master's Project Reports

This paper presents statistical techniques for estimating vehicle fuel consumption in urban road networks based on vehicle and geographical factors. A routing algorithm utilizing mapping data from OpenStreetMap and elevation data from the Shuttle Radar Topography Mission is presented and used to generate paths that minimize vehicle fuel consumption. The concept of a fuel consumption estimating function is proposed as an extension of the well-known distance-estimating functions that are widely used in logistics planning and research.

Statistical models are developed that estimate fuel consumption in three tested urban areas with vehicle weight, elevation and regional travel speed characteristics being the ...


Automating Variation And Repeater Analysis In Physical Design Of Integrated Circuits, Subrat Mahalik Aug 2018

Automating Variation And Repeater Analysis In Physical Design Of Integrated Circuits, Subrat Mahalik

Dissertations and Theses

Rapid advancement and innovation in semiconductor research have continuously helped in designing efficient and complex integrated circuits in miniature size. As the device technology, is aggressively scaling to improve the device performance, the issues related to device interconnects, power, and reliability have become a major concern for the designers. These challenges make the design and validation of ASIC extremely complicated.

The primary idea of this work is to develop automation tools, to be used in the physical design flows to improve the efficiency of the design flow. The first tool named as variation analysis tool automates the on-chip variation modeling ...


Chemo-Thermo Cure Of Viscoelastic Materials For Semiconductor Packaging Applications, Anjali Pradeep Kumar Aug 2018

Chemo-Thermo Cure Of Viscoelastic Materials For Semiconductor Packaging Applications, Anjali Pradeep Kumar

Dissertations and Theses

Viscoelastic polymer materials are being actively considered as a novel material for semiconductor packaging applications as a result of their ability to develop strong adhesive bonds at lower temperatures. Viscoelastic thermoset materials are impacted by the stresses generated during the curing process, which is also accompanied by a dissipation of thermal energy. There is a need to develop a generic modeling formulation that is applicable to any material of interest in order to enable the study of different bonding materials and develop optimized curing cycles. This study reports a numerical formulation to evaluate the stress generated and energy dissipated during ...


Webinar: Meeting & Exceeding Mobility User Expectations With Real-Time Transit Information, Sean J. Barbeau, Derek Fretheim Aug 2018

Webinar: Meeting & Exceeding Mobility User Expectations With Real-Time Transit Information, Sean J. Barbeau, Derek Fretheim

TREC Webinar Series

Every day transit riders ask the same question: when’s the next one coming? To answer this question, transit agencies are transitioning to providing real-time transit information through smartphones or displayed at transit stops.

The proliferation of transit planning and real time arrival tools that have hit the market over the past decade is staggering. Yet with transit ridership on the decline, agencies can’t afford to ignore the importance of providing accurate, real time information to their customers. Real-time transit information improves the reliability and efficiency of passenger travel, but barriers have prevented some transit agencies from adopting the ...


Human-Centered Design Of An Air Quality Feedback System To Promote Healthy Cooking, Chantal Iribagiza Jul 2018

Human-Centered Design Of An Air Quality Feedback System To Promote Healthy Cooking, Chantal Iribagiza

Dissertations and Theses

Household air pollution (HAP) is responsible for almost 4 million premature deaths every year, a burden that is primarily carried by women and children in developing countries. The mortality and morbidity impact of HAP can be significantly alleviated through clean cookstove interventions. However, for these interventions to be effective, the new intervention stove must be a substantially cleaner technology and adoption should be high and sustained over time.

Woody biomass is the fuel of choice in many developing communities, and contributes substantially to HAP. Several organizations have launched clean cooking interventions to address this issue. However, the majority of those ...


Reliability Of Solder Joints In Embedded Packages Using Finite Element Methods, Valeri Aisha Yunusa Jul 2018

Reliability Of Solder Joints In Embedded Packages Using Finite Element Methods, Valeri Aisha Yunusa

Dissertations and Theses

Solder joints serve as both mechanical and electrical connections between elements in a package. They are subjected to shear strains generated as a result of the different behaviors of the elements in the package (tension and compression) due to the differences in coefficients of thermal expansion during service conditions.

Some of the causes of solder joint failures are due to the following:

Vibration: small rapid displacements of parts of the assembly. This is not necessarily an issue with electronic components but larger parts like automobiles.

Humidity: the package being exposed to water or ionic species can undergo corrosion if an ...


Cyclists' Queue Discharge Characteristics At Signalized Intersections, Kirk Thomas Paulsen Jul 2018

Cyclists' Queue Discharge Characteristics At Signalized Intersections, Kirk Thomas Paulsen

Dissertations and Theses

Wider bike facilities intuitively accommodate a greater number of cyclists in the same amount of time, but specific queue discharge characteristics associated with varying widths and/or types of bike facilities have not been thoroughly documented.

The focus of this research analyzed queues of cyclists at four signalized intersections in Portland, OR with varying widths on the approach and downstream intersection legs. A total of 2,820 cyclists within 630 groups of queued cyclists were observed at five different intersection layouts in Portland, Oregon. The layouts consisted of: a standard bike lane six feet wide connecting bicyclists to a standard ...


Adoption Of An Internet Of Things Framework For Distributed Energy Resource Coordination And Control, Tylor Slay Jul 2018

Adoption Of An Internet Of Things Framework For Distributed Energy Resource Coordination And Control, Tylor Slay

Dissertations and Theses

Increasing penetration of non-dispatchable renewable energy resources and greater peak power demand present growing challenges to Bulk Power System (BPS) reliability and resilience. This research investigates the use of an Internet of Things (IoT) framework for large scale Distributed Energy Resource (DER) aggregation and control to reduce energy imbalance caused by stochastic renewable generation. The aggregator developed for this research is Distributed Energy Resource Aggregation System (DERAS). DERAS comprises two AllJoyn applications written in C++. The first application is the Energy Management System (EMS), which aggregates, emulates, and controls connected DERs. The second application is the Distributed Management System (DMS ...


Assessment Of Seismic Retrofit Prioritization Methodology For Oregon's Highway Bridges Based On The Vulnerability Of Highway Segments, Selamawit Tesfayesus Mehary Jul 2018

Assessment Of Seismic Retrofit Prioritization Methodology For Oregon's Highway Bridges Based On The Vulnerability Of Highway Segments, Selamawit Tesfayesus Mehary

Dissertations and Theses

Geologists have indicated that the question is not if a catastrophic earthquake will occur in Oregon but when one will occur. Scientists estimate that there is close to 40 percent conditional probability that a Cascadia subduction zone earthquake of magnitude 8.0 or above will strike Oregon in the next 50 years. In addition, the majority of Oregon's bridge inventory was built prior to the current understanding of bridge response and prior to current understanding of the expected earthquake demands. In order to minimize potential bridge damage in the case of an earthquake, one approach is to retrofit seismically ...


Short-Term Tracking Of Orientation With Inertial Sensors, Golriz Sedaghat Jul 2018

Short-Term Tracking Of Orientation With Inertial Sensors, Golriz Sedaghat

Dissertations and Theses

In the past several years, IMU's have been widely used to measure the orientation of a moving body over a continuous period of time. Although, inertial navigation is a common approach for estimating the orientation, it greatly suffers from the accumulation of error in the orientation estimation. Most of the current common practices apply zero velocity update as a calibration method to address this problem and improve the estimation accuracy. However, this approach requires the sensors to be stationary frequently.

This thesis introduces a novel method of calibration for estimating the elevation and bank angles of the orientation over ...


Electro-Drop Bouncing In Low-Gravity, Erin Stivers Schmidt Jul 2018

Electro-Drop Bouncing In Low-Gravity, Erin Stivers Schmidt

Dissertations and Theses

We investigate the dynamics of spontaneous jumps of water drops from electrically charged superhydrophobic dielectric substrates during a sudden step reduction in gravity level. In the brief free-fall environment of a drop tower, with a non-homogeneous external electric field arising due to dielectric surface charges (with surface potentials 0.4-1.8 kV), body forces acting on the jumped drops are primarily supplied by polarization stress and Coulombic attraction instead of gravity. This electric body force leads to a drop bouncing behavior similar to well-known phenomena in 1-g 0 , though occurring for much larger drops (∼ 0.5 mL). We show ...


Flip-Chip (Fc) And Fine-Pitch-Ball-Grid-Array (Fpbga) Underfills For Application In Aerospace Electronics—Brief Review, Ephraim Suhir, Reza Ghaffarian Jul 2018

Flip-Chip (Fc) And Fine-Pitch-Ball-Grid-Array (Fpbga) Underfills For Application In Aerospace Electronics—Brief Review, Ephraim Suhir, Reza Ghaffarian

Mechanical and Materials Engineering Faculty Publications and Presentations

In this review, some major aspects of the current underfill technologies for flip-chip (FC) and fine-pitch-ball-grid-array (FPBGA), including chip-size packaging (CSP), are addressed, with an emphasis on applications, such as aerospace electronics, for which high reliability level is imperative. The following aspects of the FC and FPGGA technologies are considered: attributes of the FC and FPBGA structures and technologies; underfill-induced stresses; the roles of the glass transition temperature (Tg) of the underfill materials; some major attributes of the lead-free solder systems with underfill; reliability-related issues; thermal fatigue of the underfilled solder joints; warpage-related issues; attributes of accelerated life testing ...


Boro-Austempering Treatment Of Ductile Cast Irons, Fábio Edson Mariani, Carolina Soares, Amadeu Lombardi Neto, George Totten, Luiz Carlos Casteletti Jul 2018

Boro-Austempering Treatment Of Ductile Cast Irons, Fábio Edson Mariani, Carolina Soares, Amadeu Lombardi Neto, George Totten, Luiz Carlos Casteletti

Mechanical and Materials Engineering Faculty Publications and Presentations

Samples of ductile cast irons alloyed with Cu, Cu-Ni and Cu-Ni-Mo were austempered, borided and boro-austempered and characterized for hardness and micro-adhesive wear behavior. The kinetics of layer formation was also studied. The boriding method used was molten borax bath, in periods of 2 and 4 hours at temperatures of 850, 900 and 950º C. The direct austempering treatment was performed immediately following the boriding treatment (from 850, 900 and 950º C) using molten salt baths at temperatures of 240, 300 and 360º C for 4 hours (boro-austempering treatment). For comparative purposes, the conventional austempering treatment was also conducted. Optical ...


Precipitation Impacts On Groundwater Levels In The Ephemeral Holgate Lake: A Modflow Inquiry, Amory Cervarich Jun 2018

Precipitation Impacts On Groundwater Levels In The Ephemeral Holgate Lake: A Modflow Inquiry, Amory Cervarich

Civil and Environmental Engineering Undergraduate Honors Theses

Holgate Lake, an ephemeral lake located in southeast Portland, has a history of flooding and inundating residential areas. The appearance of the lake is hypothesized to be a function of precipitation-driven changes in groundwater levels. A model was developed using MODFLOW-NWT, a U.S. Geological Survey (USGS) modular hydrologic program, to analyze parameters contributing to the appearance of the lake. The model was most sensitive to changes in aquifer properties including hydraulic conductivity and storativity. The model displayed low sensitivity to changes in precipitation, evapotranspiration, and conductance of surface waters. Results from the analysis contribute to a better understanding of ...


Evaluating The Applicability Of Modflow2005 Plus Mt3d-Usgs: Borden Case Study, Linley Mescher Jun 2018

Evaluating The Applicability Of Modflow2005 Plus Mt3d-Usgs: Borden Case Study, Linley Mescher

Civil and Environmental Engineering Master's Project Reports

Groundwater is essential to communities around the world for drinking, industrial, and agricultural purposes. MODFLOW is a modeling program that uses the three-dimensional continuity equation in a finite difference approach to simulate groundwater flow in an aquifer. MT3D-USGS is a MODFLOW package that simulates contaminant transport. This study used MODFLOW2005 with MT3D-USGS to build a model simulating contaminant transport in Borden, Ontario. A study conducted at the Borden site in 1982 injected a solution of eight solutes to test the transport of contaminants over three years. Initial simulations showed similar transport characteristics for chloride and carbon tetrachloride as compared to ...


Non-Linear Deformation Analysis Of An Embankment Dam, Silas T. Sanderson Jun 2018

Non-Linear Deformation Analysis Of An Embankment Dam, Silas T. Sanderson

Civil and Environmental Engineering Master's Project Reports

Non-linear deformation analysis (NDA) of embankment dams is becoming more common as geotechnical engineers seek to better understand how critical infrastructure will perform under high seismic loading. In order to perform this type of analysis, site specific ground motions and engineering properties of the embankment dam are required. The NDA modeling effort consists of a static and seepage analysis to establish an initial stress state followed by a dynamic analysis to simulate the embankment response to ground motions. Using this approach, a two dimensional NDA was performed on an embankment dam using the NDA program FLAC. This report discusses the ...


Biomimetic Design And Construction Of A Bipedal Walking Robot, Alexander Gabriel Steele Jun 2018

Biomimetic Design And Construction Of A Bipedal Walking Robot, Alexander Gabriel Steele

Dissertations and Theses

Human balance and locomotion control is highly complex and not well understood. To understand how the nervous system controls balance and locomotion works, we test how the body responds to controlled perturbations, the results are analyzed, and control models are developed. However, to recreate this system of control there is a need for a robot with human-like kinematics. Unfortunately, such a robotic testbed does not exist despite the numerous applications such a design would have in mobile robotics, healthcare, and prosthetics.

This thesis presents a robotic testbed model of human lower legs. By using MRI and CT scans, I designed ...


Electric Water Heater Modeling For Distributed Energy Resource Aggregation And Control, Anne E. Clarke Jun 2018

Electric Water Heater Modeling For Distributed Energy Resource Aggregation And Control, Anne E. Clarke

Dissertations and Theses

Today's utilities face new challenges due to the continually increasing penetration of residential solar and other distributed, stochastic generation sources. In order to maintain balance and stability in the grid without building costly, large-scale generation plants, utilities are turning to distributed energy resources for use in demand response programs. Demand response is a cost-efficient way to balance grid load/generation without the need for increased capital investment in traditional generation resources. Demand response programs are excellent exploiters of end-user devices that otherwise further accentuate the daily load curve and thus, add to the difficulties created by daily load peaks ...


Webinar: Firsthand Data Collection: Students Get Behind The Wheel Of Vehicle Dynamics, Roger Lindgren, Jordan Preston Jun 2018

Webinar: Firsthand Data Collection: Students Get Behind The Wheel Of Vehicle Dynamics, Roger Lindgren, Jordan Preston

TREC Webinar Series

Vehicle operating dynamics data have a fundamental impact on the design of roadways, but collecting this type of data is not part of your typical college curriculum. Instead, engineering students are handed a textbook, leaving them without a firsthand experience of how accelerations and decelerations “feel” to the driver, the ultimate consumer of their designs. Seeking to change this norm, Roger Lindgren and C.J. Riley, civil engineering professors at the Oregon Institute of Technology, undertook a NITC education project to incorporate more real-world data collection and analysis into transportation courses. This webinar will offer a detailed look at the ...