Engineering Commons^™

Bayesian Optimization For Refining Object Proposals, Anthony D. Rhodes, Jordan Witte, Melanie Mitchell, Bruno Jedynak

Computer Science Faculty Publications and Presentations

We develop a general-purpose algorithm using a Bayesian optimization framework for the efficient refinement of object proposals. While recent research has achieved substantial progress for object localization and related objectives in computer vision, current state-of-the-art object localization procedures are nevertheless encumbered by inefficiency and inaccuracy. We present a novel, computationally efficient method for refining inaccurate bounding-box proposals for a target object using Bayesian optimization. Offline, image features from a convolutional neural network are used to train a model to predict an object proposal’s offset distance from a target object. Online, this model is used in a Bayesian active search to …

Benzene Formation In Electronic Cigarettes, James F. Pankow, Kilsun Kim, Kevin J. Mcwhirter, Wentai Luo, Jorge O. Escobedo, Robert M. Strongin, Anna K. Duell, David H. Peyton

Chemistry Faculty Publications and Presentations

The heating of the fluids used in electronic cigarettes (“e-cigarettes”) used to create “vaping” aerosols is capable of causing a wide range of degradation reaction products. We investigated formation of benzene (an important human carcinogen) from e-cigarette fluids containing propylene glycol (PG), glycerol (GL), benzoic acid, the flavor chemical benzaldehyde, and nicotine.

Mass Exchange Dynamics Of Surface And Subsurface Oil In Shallow-Water Transport, Saeed Moghimi, Jorge Ramirez, Juan M. Restrepo, Shankar Venkataramani

Civil and Environmental Engineering Faculty Publications and Presentations

We formulate a model for the mass exchange between oil at and below the sea surface. This is a particularly important aspect of modeling oil spills. Surface and subsurface oil have different chemical and transport characteristics and lumping them together would compromise the accuracy of the resulting model. Without observational or computational constraints, it is thus not possible to quantitatively predict oil spills based upon partial field observations of surface and/or sub-surface oil. The primary challenge in capturing the mass exchange is that the principal mechanisms are on the microscale. This is a serious barrier to developing practical models for …

Using Satellite Observations To Characterize The Response Of Estuarine Turbidity Maxima To External Forcing, Austin S. Hudson, Stefan A. Talke, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

This study explores the spatial and temporal character of turbidity maxima in the Columbia River Estuary (CRE) using satellite observations. Surface reflectance data measured by the Moderate Imaging Spectroradiometer (MODIS) were calibrated against in situ measurements of surface turbidity (R2 = 0.85 for 205 measurements). More than 1500 satellite images from 2000 to 2015 were then conditionally sampled to explore the physical processes that drive the spatial distribution of the turbidity field. We find satellite measurements are able to describe seasonal, spring–neap, and spatial features of the estuarine turbidity maxima (ETM) that are not easily observable by other means. System-wide …

Quadded Gasp: A Fault Tolerant Asynchronous Design, Kristopher S. Scheiblauer

Dissertations and Theses

As device scaling continues, process variability and defect densities are becoming increasingly challenging for circuit designers to contend with. Variability reduces timing margins, making it difficult and time consuming to meet design specifications. Defects can cause degraded performance or incorrect operation resulting in circuit failure. Consequently test times are lengthened and production yields are reduced.

This work assess the combination of two concepts, self-timed asynchronous design and fault tolerance, as a possible solution to both variability and defects. Asynchronous design is not as sensitive to variability as synchronous, while fault tolerance allows continued functional operation in the presence of defects. …

Exploring The Positive Utility Of Travel And Mode Choice, Patrick Allen Singleton

PSU Transportation Seminars

Why do people travel? We traditionally assume traveling is a means to an end, travel demand is derived (from the demand for activities), and travel time is to be minimized. Recently, scholars have questioned these axioms, noting that some people may like to travel, use travel time productively, enjoy the experience of traveling, or travel for non-utilitarian reasons. The idea that travel can provide benefits and may be motivated by factors beyond reaching activity destinations is known as “the positive utility of travel” or PUT.

This study presents a conceptual and empirical look at the positive utility of travel and …

Altruistic Punishment Can Help Resolve Tragedy Of The Commons Social Dilemmas, Garrison W. Greenwood

Electrical and Computer Engineering Faculty Publications and Presentations

Social dilemmas force individuals to choose between cooperation, which benefits a group, and defection which benefits the individual. The unfortunate outcome in most social dilemmas is mutual defection where nobody benefits. Researchers frequently use mathematical games such as public goods games to help identify circumstances that might improve cooperation levels within a population. Altruistic punishment has shown promise in these games. Many real-world social dilemmas are expressed via a tragedy of the commons metaphor. This paper describes an investigation designed to see if altruistic punishment might work in tragedy of the commons social dilemmas. Simulation results indicate not only does …

Webinar: Integrating Explicit And Implicit Methods In Travel Behavior Research: A Study Of Driver Attitudes And Bias, Tara Goddard

TREC Webinar Series

Car crashes are still a leading cause of death in the United States, with vulnerable road users like bicyclists and pedestrians being injured or killed at rates that outpace their mode share.

Planners, engineers, and advocates are increasingly adopting Vision Zero and Tactical Urbanism approaches and trying to better understand the underlying causes of dangerous roadway interactions. However, existing research into crash causation has focused on instrumental factors (e.g. intersection type, vehicle speed) while little research has probed the role of attitudes or socio-cognitive mechanisms in interactions between roadway users.

Social psychology suggests that attitudes and social cognitions can play …

Using Fuzzy Cognitive Maps To Model Policy Issues In The Face Of Uncertainty And Limited Data, Brian Gregor

PSU Transportation Seminars

Planners and policymakers are often faced with the need to make decisions about issues for which there is uncertainty and limited data. For example, transportation planners are now faced with the prospect that new transportation technologies such as autonomous vehicles could greatly alter future transportation system needs. Decisions about these types of issues are difficult to reason about and consequently are likely to be ignored or made on the basis of simplistic logic. Although modeling could be helpful, especially for issues involving complex systems, it is rarely used because models usually require large amounts of data and and handle uncertainty …

Analysis Of A Magnetically Geared Lead Screw, Mojtaba Bahrami Kouhshahi, Jonathan Bird

Electrical and Computer Engineering Faculty Publications and Presentations

Linear magnetic gearboxes (LMG) and magnetic lead screws (MLS) have been shown to be capable of operating at significantly higher volumetric force densities than traditional electromagnetic linear actuators (ELA). However in both such devices the linear translator must be made of magnet material and therefore if the stroke length of the translator is long the cost of the MLS and LMG will become prohibitively high. In this paper a magnetically geared lead screw (MGLS) is investigated and its performance capability is compared with the LMG and MLS. The advantage of the MGLS is that the translator does not contain magnets.

Hydrodynamic And Water Quality Modeling Of The Chehalis River Using Ce-Qual-W2, Sarah Van Glubt

Dissertations and Theses

The Chehalis River Basin is located in the southwest region of Washington State, originating in the Olympic Mountains and flowing to Grays Harbor and the Pacific Ocean. The Chehalis River is over 125 miles, exists within five counties, and flows through agricultural, residential, industrial, and forest land areas. Four major rivers discharge to the Chehalis River, as well as many smaller creeks, five wastewater treatment plants, and groundwater flows.

Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia, with severe consequences for property, safety and transportation. As a result, construction of a …

Ideal Radial Permanent Magnet Coupling Torque Density Analysis, Kang Li, Jonathan Bird, Vedanadam M. Acharya

Electrical and Computer Engineering Faculty Publications and Presentations

This paper derives the closed form 3-D analytical torque equations for an ideal radial Halbach rotor magnetic coupling. The performance of the radial Halbach coupling is then compared with an ideal axial Halbach rotor coupling. The closed form equations and comparison gives insight into the upper torque density limits of Nd-Fe-B based magnetic devices.

Development Of A Technology Transfer Score For Evaluating Research Proposals: Case Study Of Demand Response Technologies In The Pacific Northwest, Judith Estep

Dissertations and Theses

Investment in Research and Development (R&D) is necessary for innovation, allowing an organization to maintain a competitive edge. The U.S. Federal Government invests billions of dollars, primarily in basic research technologies to help fill the pipeline for other organizations to take the technology into commercialization. However, it is not about just investing in innovation, it is about converting that research into application. A cursory review of the research proposal evaluation criteria suggests that there is little to no emphasis placed on the transfer of research results. This effort is motivated by a need to move research into application.

One segment …

Achieving Operational Seismic Performance Of Rc Bridge Bents Retrofitted With Buckling-Restrained Braces, Ramiro Andrés Gabriel Bazáez Gallardo

Dissertations and Theses

Typical reinforced concrete (RC) bridges built prior to 1970 were designed with minimum seismic consideration, leaving numerous bridges highly susceptible to damage following an earthquake. In order to improve the seismic behavior of substandard RC bridges, this study presents the seismic performance of reinforced concrete bridge bents retrofitted and repaired using Buckling-Restrained Braces (BRBs) while considering subduction zone earthquake demands. In order to reflect displacement demands from subduction ground motions, research studies were conducted to develop quasi-static loading protocols and then investigate their effect on structural bridge damage. Results suggested that subduction loading protocols may reduce the displacement ductility capacity …

A Low Assembly Cost Coaxial Magnetic Gearbox, Kiran Uppalapati, Joshua Kadel, Jason Wright, Kang Li, Wesley Williams, Jonathan Bird

Electrical and Computer Engineering Faculty Publications and Presentations

This paper presents the design investigation and experimental testing of a flux-focusing magnetic gearbox with a three piece laminated rotor structure. Each rotor is made of a single lamination stack held together via thin lamination bridges. It is calculated that mechanical bridges reduces the torque density from 156Nm/L to 139Nm/L (a reduction of 11%). The experimentally measured torque density is shown to be only 95Nm/L because the magnets were demagnetized during testing.

Toward Improving Electrocardiogram (Ecg) Biometric Verification Using Mobile Sensors: A Two-Stage Classifier Approach, Robin Tan, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

Electrocardiogram (ECG) signals sensed from mobile devices pertain the potential for biometric identity recognition applicable in remote access control systems where enhanced data security is demanding. In this study, we propose a new algorithm that consists of a two-stage classifier combining random forest and wavelet distance measure through a probabilistic threshold schema, to improve the effectiveness and robustness of a biometric recognition system using ECG data acquired from a biosensor integrated into mobile devices. The proposed algorithm is evaluated using a mixed dataset from 184 subjects under different health conditions. The proposed two-stage classifier achieves a total of 99.52% subject …

Reversible Control Of The Magnetization Of Fe₃O₄ Via Lithium Ions, Guodong Wei, Lin Wei, Dong Wang, Yufeng Tian, Yanxue Chen, Shishen Yan, Liangmo Mei, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

In this report, a reversible control of Fe₃O₄ saturated magnetization by Li ions is demonstrated. A miniature Li ion battery (LIB) was assembled using a Fe₃O₄ nanoparticle layer as the active cathode. A stable magnetism modulation is realized by a nondestructive electrochemical process in which the lithium insertion results in a valence change and partial redistribution of Fe cations in the crystal structure. The relation between the discharge voltage and the chemical phases were studied by ex situ X-ray diffraction and magnetic measurement. In a suitable discharge potential range, a reversible control of Fe₃O₄ saturated magnetization was obtained without structural …

Estimating Reliability Indices And Confidence Intervals For Transit And Traffic At The Corridor Level, Travis B. Glick

PSU Transportation Seminars

As congestion worsens, the importance of rigorous methodologies to estimate travel-time reliability increases. Exploiting fine-granularity transit GPS data, this research proposes a novel method to estimate travel-time percentiles and confidence intervals. Novel transit reliability measures based on travel-time percentiles are proposed to identify and rank low-performance hotspots; the proposed reliability measures can be utilized to distinguish peak-hour low performance from whole-day low performance. As a case study, the methodology is applied to a bus transit corridor in Portland, Oregon. Time-space speed profiles, heatmaps, and visualizations are employed to highlight sections and intersections with high travel-time variability and transit low performance. …

Current Efforts To Make Bike Share More Equitable: A Survey Of System Owners And Operators, Steven Howland

PSU Transportation Seminars

The number of public bike share systems has been increasing rapidly across the United States over the past five to ten years. To date most academic research around bike share in the U.S. has focused on the logistics of planning and operationalizing successful systems. Investigations of system users and impacts on the local community are less common, and studies focused on efforts to engage underserved communities in bike share are rarer still. This paper utilizes a survey of representatives from 55 U.S. bike share systems to better understand and document current approaches toward serving low income and minority populations. The …

Webinar: Improving Walkability At Signalized Intersections With Signal Control Strategies, Edward J. Smaglik, Sirisha Murthy Kothuri

TREC Webinar Series

The goal of signal timing at an intersection should be to maximize efficiency for all users. In many jurisdictions, however, traffic signals are timed mostly with the goal of reducing vehicular delay.

Other road users, such as pedestrians, deserve similar focus. In legacy transportation systems, pedestrians experience delays much in excess of those that would be deemed acceptable for a motor vehicle at the same location.

Excessive delay can lead to pedestrian frustration, non-compliance and ultimately decreased safety.

In the North American context, implementation of strategies to address pedestrian service varies greatly across jurisdictions, and there has been limited research …

Avoiding Bus Bunching: From Theory To Practice, Ricardo Giesen

PSU Transportation Seminars

The problem of bus bunching in a high frequency service has been largely studied in the literature.

This phenomenon is produced by three main factors

(i) the variability in travel time between stops; (ii) variations in passenger demand; and (iii) drivers’ heterogeneity.

In order to tackle this phenomenon a wide range of control strategies have been proposed, however, none of them had been successfully implemented on a large transit network with high frequency services.

In this talk, we present a control scheme based on a rolling horizon optimization problem that has been successfully implemented for real-time control of two high …

Survey Of Value Assessment Programs Within Transportation Construction Projects In U.S, Rafaa Khalifa, Robert Stewart

Engineering and Technology Management Faculty Publications and Presentations

In order to deliver transportation project on time and within budget, project planners and decision makers need to understand the desirable outcomes of projects or programs to make intelligent decisions. In addition, they also need effective tools and techniques to guide those decisions. In development of a guide that identifies available tools and techniques to foster useable and improved practices for key stakeholders of transportation projects, this paper as a preliminary study assessed current utilization of project delivery value improvement programs such as value engineering (VE), risk analysis/management (RA/RM) and constructability reviews (CR) for transportation projects. To determine whether states …

Seismic Evaluation Of 196kv Transformer Bushings, Joanne R. Shields

Civil and Environmental Engineering Master's Project Reports

Transformer bushings have shown to have an unsatisfactory performance during earthquakes and have therefore been chosen for further testing. How the bushings fail, and how this failure can be prevented has been analyzed. Two used 196 kV bushings made by General Electric were chosen for seismic testing at the iSTAR laboratory located at Portland State University in Portland, OR. The multiple objectives that brought about these tests were: to determine how the bushings failed due to gasket extrusion at the porcelain-flange connection and to verify that the failure was due to pure tipping and not sliding, to determine the damping …

Seismic Retrofit Case Study Of Reinforced Concrete Bridges With Buckling Restrained Braces, Michael K. Miotke

Civil and Environmental Engineering Master's Project Reports

Many highway bridges in Oregon have been designed with minimal considerations for seismic hazard and are in need of retrofit. Although buckling restrained braces (BRBs) are not necessarily a new concept, using them to seismically retrofit bridges is. This case study investigates the BRB retrofit concept as compared to traditional retrofit measures for a sample of typical vulnerable bridges in Oregon. The objectives of evaluating these cases were to determine the feasibility of the concept both in terms of performance as well as construction costs. This study builds on the ongoing research at Portland State University into the development of …

Feasibility Determination Guide For The Road Diet Plus: A Five/Four-Lane To Two-Lane Road Diet, Michael Williams

Civil and Environmental Engineering Master's Project Reports

Road diets are a popular tool for corridor improvement. Road diets are normally defined as the conversion of a four-lane undivided road to a three-lane undivided road made up of two through lanes separated by a center two-way-left-turn-lane (known as a TWLTL). This new configuration has similar vehicular capacity, greater safety and frees up right-of-way for other uses.

This work examines the possibility of going one step, or one lane, further. What is the possibility of reducing five- or four-lane roads to two-lanes? If this is possible, what are the corridor characteristics within which this process would be feasible?

The …

Improving Walkability Through Control Strategies At Signalized Intersections, Sirisha Murthy Kothuri, Andrew Kading, Edward J. Smaglik, Christopher Sobie

TREC Final Reports

As cities and communities nationwide seek to develop Complete Streets that foster livability and accommodate all modes, signal timing control strategies that include pedestrians in the operational decision process are gaining importance. This research tested several efficiency-focused pedestrian treatments – coordination, actuated-coordination, free operation, short cycle lengths – and safety-focused treatment including leading pedestrian intervals and Barnes Dance. Using a software-in-the-loop simulation, the operational impacts of these treatments on all users (vehicles, heavy vehicles, bicyclists and pedestrians) at an intersection were evaluated. Results showed that among the efficiency-based treatments, free operation was most beneficial for reducing minor-street pedestrian delays. Both …

Proving Non-Deterministic Computations In Agda, Sergio Antoy, Michael Hanus, Steven Libby

Computer Science Faculty Publications and Presentations

We investigate proving properties of Curry programs using Agda. First, we address the functional correctness of Curry functions that, apart from some syntactic and semantic differences, are in the intersection of the two languages. Second, we use Agda to model non-deterministic functions with two distinct and competitive approaches incorporating the non-determinism. The first approach eliminates non-determinism by considering the set of all non-deterministic values produced by an application. The second approach encodes every non-deterministic choice that the application could perform. We consider our initial experiment a success. Although proving properties of programs is a notoriously difficult task, the functional logic …

Workshop Synthesis: Measuring Attitudes And Perceptions In Quantitative Surveys, Kelly Clifton, Juan Antonio Carrasco

Civil and Environmental Engineering Faculty Publications and Presentations

This workshop engaged participants in discussion about issues in incorporating qualitative information, namely attitudes, perceptions, and other psychological-social factors into transport research and analysis. There are many challenges to collecting this information from respondents. This synthesis summarizes the workshop presentations and discussion where participants identified the various types of information desired, reviewed the current challenges in conducting this type of data collection, made recommendations for practice, and outlined an agenda for future research.

Development Of Self-Sensing Carbon Nanotube-Based Composites For Civil Infrastructure Applications, Thomas Schumacher, Erik T. Thostenson

Civil and Environmental Engineering Faculty Publications and Presentations

Presented at the 5th International Symposium on Sensor Science (I3S 2017), Barcelona, Spain, 27–29 September 2017.

Worldwide, civil infrastructure systems are aging and deteriorating due to maintenance neglect, increasing traffic, and an environment that is becoming increasingly more severe. In particular, bridges play a critical role in the transportation network. With limited monies available for maintenance and repair, a need exists for effective yet inexpensive solutions to strengthen and monitor bridges. This presentation provides an overview of the development of carbon nanotube (CNT)-based composites, which offer a means to strengthen and monitor a deteriorated bridge member simultaneously. CNT sensors are …

Differences Of Cycling Experiences And Perceptions Between E-Bike And Bicycle Users In The United States, Ziwen Ling, Christopher R. Cherry, John Macarthur, Jonathan X. Weinert

Civil and Environmental Engineering Faculty Publications and Presentations

E-bikes are bicycles that provide pedal-assistance to aid people in cycling. Because of the potential of promoting sustainable transportation, more attention has been focused on the e-bike market. This paper investigates the differences of the cycling experience and perceptions between e-bike and conventional bicycle users, using samples drawn from independent bicycle dealer customers. A total of 806 respondents in the United States took the on-line survey, including 363 e-bike-owning respondents. The results show that e-bikes play a more important role in utilitarian travel, such as commuting and running errands, compared to a conventional bicycle. Conventional bicycle-owning respondents use their bicycles …