Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Portland State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1171 - 1200 of 2758

Full-Text Articles in Engineering

The Effect Of Plasma On Graphene Quality In An Inductively Couple Plasma Chemical Vapor Deposition Reactor, Brendan Coyne May 2017

The Effect Of Plasma On Graphene Quality In An Inductively Couple Plasma Chemical Vapor Deposition Reactor, Brendan Coyne

Maseeh Summer Undergraduate Research Experience

Despite continued interest in research and application development, full scale graphene production is still limited by many factors including prohibitively high growth temperature requirements. Extremely high quality graphene growth is possible at high temperatures using chemical vapor deposition (CVD). Use of an inductively coupled plasma chemical vapor deposition (ICP CVD) reactor with the benefit of precursor gas decomposition through plasma generation, may provide possibility to reduce growth temperature. Herein, we report plasma’s effects on graphene growth by comparing growths of increasing power supplied to plasma generation and changes in precursor gas ratios. Plasma composition was characterized by ultraviolet and visible …


The Aerodynamic Effects On Flight Patterns And The Evolutionary Changes In Pterosaurs, Johnathan D. Talik May 2017

The Aerodynamic Effects On Flight Patterns And The Evolutionary Changes In Pterosaurs, Johnathan D. Talik

Maseeh Summer Undergraduate Research Experience

Early pterosaurs were the first vertebrates to achieve powered flight, and remained small-to-medium sized from the Triassic Period to the end of the Jurassic Period. During that interval, lasting from 210 million years ago to 66 million years ago, pterosaurs underwent a notable changes at the end of the Jurassic Period and through the Cretaceous Period. They were abruptly replaced by much larger forms, characterized by great size and peculiar head ornamentation, among other unique and notable morphological features. While many different explanations theorize why and how the features of the pterosaurs changed over the Cretaceous Period, the aerodynamic influences …


Evaluating The Distributional Effects Of Regional Transportation Plans And Projects, Kristine Williams, Aaron Golub May 2017

Evaluating The Distributional Effects Of Regional Transportation Plans And Projects, Kristine Williams, Aaron Golub

TREC Final Reports

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes. Funded by the National Institute for Transportation and Communities, this research aims to provide additional guidance to MPOs on how to evaluate distributional equity in regional plans and projects. The report begins with an overview of federal requirements related to equity in transportation planning. We then synthesize contemporary methods for measuring transportation equity and the distributional effects of plans and projects from a review of the literature and MPO plans and studies. The report concludes with exploratory case studies of …


Transport Planning In Delft, Netherlands, Jan Nederveen Apr 2017

Transport Planning In Delft, Netherlands, Jan Nederveen

PSU Transportation Seminars

While the Netherlands is known today for the highest bicycling rates in the world, this movement only began in the 1970s. Transportation policy has been one of the critical keys to reducing automobile trips in the Netherlands.

Visiting scholar Jan Nederveen will present on transportation planning in the compact, densely populated city of Delft. Delft has been a city since 1246, and the historic street pattern is still visible today. The city has grown to 100,000 residents and covers an area of 5 square kilometers. Twenty years ago, the council decided to change the transportation philosophy from a car-oriented system …


A Conceptual Framework For Understanding Latent Demand: Accounting For Unrealized Activities And Travel, Kelly Clifton Apr 2017

A Conceptual Framework For Understanding Latent Demand: Accounting For Unrealized Activities And Travel, Kelly Clifton

PSU Transportation Seminars

Latent demand—the activities and travel that are desired but unrealized because of constraints—have been historically examined from the standpoint of understanding the impacts of proposed capacity or service improvements on travel demand.

Drawing on work from a variety of theoretical perspectives, this paper presents a broader conceptual view of latent demand that provides a useful framework for researching and understanding these unmet needs. This is important from an equity standpoint, as it provides insights into to questions of transport disadvantage, social exclusion and poverty.

The framework presented here is theoretical in nature and untested empirically. This study aims to promote …


Turbulent Boundary Layer Features Via Lagrangian Coherent Structures, Proper Orthogonal Decomposition And Dynamic Mode Decomposition, Naseem Ali, Murat Tutkun, Raul Bayoan Cal Apr 2017

Turbulent Boundary Layer Features Via Lagrangian Coherent Structures, Proper Orthogonal Decomposition And Dynamic Mode Decomposition, Naseem Ali, Murat Tutkun, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

High-speed stereo PIV-measurements have been performed in a turbulent boundary layer at Reθ of 9800 in order to elucidate the coherent structures. Snapshot proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) are used to visualize the flow structure depending on the turbulent kinetic energy and frequency content. The first six POD and DMD modes show the largest and the lowest amount of energy and frequency, respectively. Lagrangian coherent structure (LCS) based on the algorithm developed using the variational theory is also applied to track the flow via attracting and repelling trajectories. The shapes and the length of the trajectories …


Getting To Know The Data: Understanding Assumptions, Sensitivities, Uncertainty, And Being "Conservative" While Using Ite's Trip Generation Data In The Land Development Process, Kristina Marie Currans Apr 2017

Getting To Know The Data: Understanding Assumptions, Sensitivities, Uncertainty, And Being "Conservative" While Using Ite's Trip Generation Data In The Land Development Process, Kristina Marie Currans

PSU Transportation Seminars

Many agencies rely on trip generation estimates to evaluate the transportation impacts of land development in urban and suburban areas alike. Over the past decade, substantial attention has been paid to one national set of guidelines—the Institute of Transportation Engineers (ITE) Trip Generation Handbook (2014) and corresponding Manual (2012)—focusing in particular to improve the use of these data and supplementary methods for urban contexts.

The purpose of this study is to explore the typical data provided in the Handbook, within the context of these new improved state-of-the-art methods. As ITE’s describes, “an example of poor professional judgment is to rely …


Electrodynamic Wheel Magnetic Rolling Resistance, Wei Qin, Jonathan Z. Bird Apr 2017

Electrodynamic Wheel Magnetic Rolling Resistance, Wei Qin, Jonathan Z. Bird

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper the concept of magnetic rolling resistance (MRR) is introduced. The MRR is particularly useful when trying to characterize maglev devices that operate with a slip. Approaches to minimize the MRR for an electrodynamic wheel magnetic suspension device are discussed. MRR is calculated from the power losses and it is shown that by using MRR a direct performance comparison with existing modes of transportation can be made. The MRR for a number of different maglev designs is calculated.


An Ir And Rf Based System For Functional Gait Analysis In A Multi-Resident Smart-Home, Erich Reinhardt Schafermeyer Apr 2017

An Ir And Rf Based System For Functional Gait Analysis In A Multi-Resident Smart-Home, Erich Reinhardt Schafermeyer

Dissertations and Theses

Changes in the gait characteristics, such as walking speed and stride length, of a person living at home can be used to presage cognitive decline, predict fall potential, monitor long-term changes in cognitive impairment, test drug regimens, and more. This thesis presents a novel approach to gait analysis in a smart-home environment by leveraging new advances in inexpensive sensors and embedded systems to create novel solutions for in-home gait analysis. Using a simple, non-invasive hardware system consisting entirely of wall-mounted infrared and radio frequency sensor arrays, data is collected on the gait of subjects as they pass by. This data …


Technology Assessment Model Of Developing Geothermal Energy Resources For Supporting Electrical System: The Case For Oregon, Ahmed Shehab Alshareef Apr 2017

Technology Assessment Model Of Developing Geothermal Energy Resources For Supporting Electrical System: The Case For Oregon, Ahmed Shehab Alshareef

Dissertations and Theses

The demand for energy is increasing worldwide. All applications contributed to increase the demand of all energy industry, and therefore the effect on the environment and the rise in pollution increased significantly. This is considered a large problem, and researchers focused their research on renewable energy for reducing the cost of energy in the future. Geothermal energy has significant impact as a source of electricity generation since it will not harm the environment. There are more than twenty countries that benefit from geothermal plants, which generate more than 6000 megawatts .Three alternatives of geothermal energy technology (GHP, Direct use of …


Rate-Limited Mass Transfer Of Trichloroethene, Deza R. Irving Apr 2017

Rate-Limited Mass Transfer Of Trichloroethene, Deza R. Irving

Civil and Environmental Engineering Undergraduate Honors Theses

Trichloroethene (TCE) is a volatile and toxic contaminant commonly found in the subsurface. To help reduce the effects of this contaminant, it is important to understand the transport and fate behavior of TCE through the subsurface. As groundwater fills the void spaces of a porous media contaminated with pure-phase TCE, the TCE will dissolve into the water, contaminating the groundwater. It was expected that this dissolution would follow a first-order mass transfer process, suggesting that the rate of dissolution of TCE is dependent on the mass of TCE present in solution. The purpose of this study was to characterize the …


Dynamic Evaluation Of Transportation Structures With Ipod-Based Data Acquisition, Charles Riley Apr 2017

Dynamic Evaluation Of Transportation Structures With Ipod-Based Data Acquisition, Charles Riley

TREC Final Reports

This grant supported coursework and laboratory development and expanded research capacity, promoting (a) innovative learning activities that expose students to cutting-edge methods of bridge structural health and behavior monitoring and (b) research by our growing group of graduate students using developing technologies (specifically, shake tables and iPods with on-board accelerometers). As transportation infrastructure reaches and exceeds its design life, engineering efforts are turning to evaluation, rehabilitation and repair. Accurately assessing structures to determine their future performance and remaining life is becoming a primary job function for many civil engineers.

As part of this project, graduate students worked with the PI …


Memcapacitive Devices In Logic And Crossbar Applications, Dat Tran, Christof Teuscher Apr 2017

Memcapacitive Devices In Logic And Crossbar Applications, Dat Tran, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

Over the last decade, memristive devices have been widely adopted in computing for various conventional and unconventional applications. While the integration density, memory property, and nonlinear characteristics have many benefits, reducing the energy consumption is limited by the resistive nature of the devices. Memcapacitors would address that limitation while still having all the benefits of memristors. Recent work has shown that with adjusted parameters during the fabrication process, a metal-oxide device can indeed exhibit a memcapacitive behavior. We introduce novel memcapacitive logic gates and memcapacitive crossbar classifiers as a proof of concept that such applications can outperform memristor-based architectures. The …


Emerging Pollutants In The Columbia River: A Simple Assessment Of Nonpoint Source Zones, Chulgi Kim Apr 2017

Emerging Pollutants In The Columbia River: A Simple Assessment Of Nonpoint Source Zones, Chulgi Kim

Civil and Environmental Engineering Undergraduate Honors Theses

Water quality modeling in the Columbia River Basin was conducted at the confluence of the Willamette and Columbia Rivers, river mile 101. The study area for this research consists of Sauvie Island, OR, and the surrounding areas of Vancouver, WA. Analysis of the region’s watershed and simple hydrologic calculations allowed for estimates of potential sources contributing to PBDEs in the Columbia River along river mile 101. This research included assessment of rainfall patterns and peak discharge rates in the areas along the rivers. A simple model of overland flow for the watershed was applied to estimate the area’s contribution to …


Remote Measurements Of Tides And River Slope Using An Airborne Lidar Instrument, Austin S. Hudson, Stefan A. Talke, Ruth Branch, Chris Chickadel, Gordon Farquharson, Andrew Jessup Apr 2017

Remote Measurements Of Tides And River Slope Using An Airborne Lidar Instrument, Austin S. Hudson, Stefan A. Talke, Ruth Branch, Chris Chickadel, Gordon Farquharson, Andrew Jessup

Civil and Environmental Engineering Faculty Publications and Presentations

Tides and river slope are fundamental characteristics of estuaries, but they are usually undersampled due to deficiencies in the spatial coverage of water level measurements. This study aims to address this issue by investigating the use of airborne lidar measurements to study tidal statistics and river slope in the Columbia River estuary. Eight plane transects over a 12-h period yield at least eight independent measurements of water level at 2.5-km increments over a 65-km stretch of the estuary. These data are fit to a sinusoidal curve and the results are compared to seven in situ gauges. In situ– and lidar-based …


The Effectiveness Of Sanitary Inspections As A Risk Assessment Tool For Thermotolerant Coliform Bacteria Contamination Of Rural Drinking Water: A Review Of Data From West Bengal, India, Christian Snoad, Corey L. Nagel, Animesh Bhattacharya, Evan A. Thomas Apr 2017

The Effectiveness Of Sanitary Inspections As A Risk Assessment Tool For Thermotolerant Coliform Bacteria Contamination Of Rural Drinking Water: A Review Of Data From West Bengal, India, Christian Snoad, Corey L. Nagel, Animesh Bhattacharya, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

The use of sanitary inspections combined with periodic water quality testing has been recommended in some cases as screening tools for fecal contamination. We conducted sanitary inspections and tested for thermotolerant coliforms (TTCs), a fecal indicator bacteria, among 7,317 unique water sources in West Bengal, India. Our results indicate that the sanitary inspection score has poor ability to identify TTC-contaminated sources. Among deep and shallow hand pumps, the area under curve (AUC) for prediction of TTC > 0 was 0.58 (95% confidence interval [CI] = 0.53–0.61) and 0.58 (95% CI = 0.54–0.62), respectively, indicating that the sanitary inspection score was only …


Development And Training Of A Neural Controller For Hind Leg Walking In A Dog Robot, Alexander J. Hunt, Nicholas Szczecinski, Roger Quinn Apr 2017

Development And Training Of A Neural Controller For Hind Leg Walking In A Dog Robot, Alexander J. Hunt, Nicholas Szczecinski, Roger Quinn

Mechanical and Materials Engineering Faculty Publications and Presentations

Animals dynamically adapt to varying terrain and small perturbations with remarkable ease. These adaptations arise from complex interactions between the environment and biomechanical and neural components of the animal’s body and nervous system. Research into mammalian locomotion has resulted in several neural and neuro-mechanical models, some of which have been tested in simulation, but few “synthetic nervous systems” have been implemented in physical hardware models of animal systems. One reason is that the implementation into a physical system is not straightforward. For example, it is difficult to make robotic actuators and sensors that model those in the animal. Therefore, even …


Fast And Accurate Sparse Coding Of Visual Stimuli With A Simple, Ultra-Low-Energy Spiking Architecture, Walt Woods, Christof Teuscher Apr 2017

Fast And Accurate Sparse Coding Of Visual Stimuli With A Simple, Ultra-Low-Energy Spiking Architecture, Walt Woods, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

Memristive crossbars have become a popular means for realizing unsupervised and supervised learning techniques. Often, to preserve mathematical rigor, the crossbar itself is separated from the neuron capacitors. In this work, we sought to simplify the design, removing extraneous components to consume significantly lower power at a minimal cost of accuracy. This work provides derivations for the design of such a network, named the Simple Spiking Locally Competitive Algorithm, or SSLCA, as well as CMOS designs and results on the CIFAR and MNIST datasets. Compared to a non-spiking model which scored 33% on CIFAR-10 with a single-layer classifier, this hardware …


Design For An Aging Population, Trygve Faste, Kiersten Muenchinger Apr 2017

Design For An Aging Population, Trygve Faste, Kiersten Muenchinger

TREC Final Reports

Older Americans are increasing in numbers and addressing their needs through better public transportation design will improve their quality of life. This study sought to increase understanding of the obstacles faced by people with impairments in vision, hearing and/or mobility, which are common issues for older people, and generate physical product solutions. The research was conducted to conceptualize products, structures and services to reduce or eliminate these obstacles.

With a focus on the Eugene, OR, public bus system, elderly riders were surveyed and interviewed. Designers rode on buses noting what worked well and where problems arose. Five ride-along observations of …


Shift-Symmetric Configurations In Two-Dimensional Cellular Automata: Irreversibility, Insolvability, And Enumeration, Peter Banda, John S. Caughman Iv, Martin Cenek, Christof Teuscher Mar 2017

Shift-Symmetric Configurations In Two-Dimensional Cellular Automata: Irreversibility, Insolvability, And Enumeration, Peter Banda, John S. Caughman Iv, Martin Cenek, Christof Teuscher

Mathematics and Statistics Faculty Publications and Presentations

The search for symmetry as an unusual yet profoundly appealing phenomenon, and the origin of regular, repeating configuration patterns have been for a long time a central focus of complexity science, and physics.

Here, we introduce group-theoretic concepts to identify and enumerate the symmetric inputs, which result in irreversible system behaviors with undesired effects on many computational tasks. The concept of so-called configuration shift-symmetry is applied on two-dimensional cellular automata as an ideal model of computation. The results show the universal insolvability of “non-symmetric” tasks regardless of the transition function. By using a compact enumeration formula and bounding the number …


Microwave Instrumentation And Sensing Techniques For Quantum Efficiency And Minority-Carrier Lifetime Measurements, Kyle Benjamin Lu Mar 2017

Microwave Instrumentation And Sensing Techniques For Quantum Efficiency And Minority-Carrier Lifetime Measurements, Kyle Benjamin Lu

Dissertations and Theses

A non-contact method characterizing the quantum efficiency of a solar cell using the microwave reflectance signature is presented in this thesis. Traditional solar cell quantum efficiency (QE) measurements are only possible near the completion of the fabrication process using contacts in direct physical connection with the metalized surface tabs to probe and extract charge carriers from the device. However, pressure within the solar metrology industry to report the spectral performance of the device earlier in the manufacturing process as part of the process control loop requires that a new non-contact method be developed. This thesis work contributes the development of …


Building Energy Model Calibration For Retrofit Decision Making, Nicolas R. Johnson Mar 2017

Building Energy Model Calibration For Retrofit Decision Making, Nicolas R. Johnson

Dissertations and Theses

Accommodating the continued increase in energy demand in the face of global climate change has been a worldwide concern. With buildings in the US consuming nearly 40% of national energy, a concerted effort must be given to reduce building energy consumption. As new buildings continue to improve their efficiency through more restrictive energy codes, the other 76.9 billion square feet of current building stock falls further behind. The rate at which current buildings are being retrofit is not enough and better tools are needed to access the benefits of retrofits and the uncertainties associated with them. This study proposes a …


Addressing Data Challenges For Bicycle Crash Analysis, Eleni Christofa Mar 2017

Addressing Data Challenges For Bicycle Crash Analysis, Eleni Christofa

PSU Transportation Seminars

Although an increasing number of separated bicycle facilities have been appearing across the US over the last few years, the majority of bicyclists are still traveling on roadways shared with motorized vehicles.

As a result, bicycles are essentially double exposed to safety risk, due to their interactions with both motorized vehicles and other bicycles. In addition to this double exposure, data challenges–such as a lack of continuous counts and bicycle crash data—complicate the assessment of bicycle safety further.

This research presents a bicycle crash analysis framework for estimating bicycle crash rates accounting for both bicycle and motorized vehicle exposure as …


An Analytical System For Determining Disciplinary Vocabulary For Data-Driven Learning: An Example From Civil Engineering, Philippa Jean Otto Mar 2017

An Analytical System For Determining Disciplinary Vocabulary For Data-Driven Learning: An Example From Civil Engineering, Philippa Jean Otto

Dissertations and Theses

Data-driven learning (DDL), an inductive teaching approach in which students learn through corpus interaction, has gained recent traction as way to teach specialized vocabulary in English for Specific Purposes (ESP) classes. There is little research, however, that addresses how to choose specialized vocabulary for teaching with DDL.

This study addressed this gap in research by exploring the potential of a three-part analytical, corpus-based system for determining vocabulary to teach with DDL for a specific context of language use. This system included (1) identifying words that were significantly more frequent in a specialized expert corpus than in a corpus of general …


Land Use Mix And Pedestrian Travel Behavior: Advancements In Conceptualization And Measurement, Steven Robert Gehrke Mar 2017

Land Use Mix And Pedestrian Travel Behavior: Advancements In Conceptualization And Measurement, Steven Robert Gehrke

Dissertations and Theses

Smart growth policies have often emphasized the importance of land use mix as an intervention beholding of lasting urban planning and public health benefits. Past transportation-land use research has identified potential efficiency gains achieved by mixed-use neighborhoods and the subsequent shortening of trip lengths; whereas, public health research has accredited increased land use mixing as an effective policy for facilitating greater physical activity. However, despite the celebrated transportation, land use, and health benefits of improved land use mixing and the extent of topical attention, no consensus has been reached regarding the conceptualization and measurement of this key smart growth principle …


Application Of Numerical Modeling To Study River Dynamics: Hydro-Geomorphological Evolution Due To Extreme Events In The Sandy River, Oregon, Sarkawt Hamarahim Muhammad Mar 2017

Application Of Numerical Modeling To Study River Dynamics: Hydro-Geomorphological Evolution Due To Extreme Events In The Sandy River, Oregon, Sarkawt Hamarahim Muhammad

Dissertations and Theses

The Sandy River (OR) is a coastal tributary of the Columbia River and has a steep hydroshed 1316 square kilometers which is located on the western side of Mount Hood (elevation range 3 m to 1800 m). The system exhibits highly variable flow: Its average discharge is ~40 m3/s, and the highest recorded discharge was 1739 m3/s in 1964. In this study I model the geomorphic sensitivity of an 1800m reach located the downstream of the former Marmot Dam, which was removed in 2007. The hydro-geomorphic response to major flood has implications for system management and …


Big Data And The Future Of Travel Modeling, Greg Macfarlane Mar 2017

Big Data And The Future Of Travel Modeling, Greg Macfarlane

PSU Transportation Seminars

New technologies such as smart phones and web applications constantly collect data on individuals' trip-making and travel patterns. Efforts at using these "Big data" products, to date, have focused on using them to expand or inform traditional travel demand modeling frameworks; however, it is worth considering if a new framework built to maximize the strengths of big data would be more useful to policy makers and planners.

In this presentation Greg Macfarlane will present a discussion on elements of travel models that could quickly benefit from big data and concurrent machine learning techniques, and results from a preliminary application of …


Power-Aware Datacenter Networking And Optimization, Qing Yi Mar 2017

Power-Aware Datacenter Networking And Optimization, Qing Yi

Dissertations and Theses

Present-day datacenter networks (DCNs) are designed to achieve full bisection bandwidth in order to provide high network throughput and server agility. However, the average utilization of typical DCN infrastructure is below 10% for significant time intervals. As a result, energy is wasted during these periods. In this thesis we analyze traffic behavior of datacenter networks using traces as well as simulated models. Based on the insight developed, we present techniques to reduce energy waste by making energy use scale linearly with load. The solutions developed are analyzed via simulations, formal analysis, and prototyping. The impact of our work is significant …


Video Frame Interpolation Via Adaptive Convolution, Simon Niklaus, Long Mai, Feng Liu Mar 2017

Video Frame Interpolation Via Adaptive Convolution, Simon Niklaus, Long Mai, Feng Liu

Computer Science Faculty Publications and Presentations

Video frame interpolation typically involves two steps: motion estimation and pixel synthesis. Such a two-step approach heavily depends on the quality of motion estimation. This paper presents a robust video frame interpolation method that combines these two steps into a single process. Specifically, our method considers pixel synthesis for the interpolated frame as local convolution over two input frames. The convolution kernel captures both the local motion between the input frames and the coefficients for pixel synthesis. Our method employs a deep fully convolu- tional neural network to estimate a spatially-adaptive con- volution kernel for each pixel. This deep neural …


A Timed Colored Petri Net Simulation-Based Self-Adaptive Collaboration Method For Production-Logistics Systems, Zhengang Guo, Yingfeng Zhang, Xibin Zhao, Xiaoyu Song Mar 2017

A Timed Colored Petri Net Simulation-Based Self-Adaptive Collaboration Method For Production-Logistics Systems, Zhengang Guo, Yingfeng Zhang, Xibin Zhao, Xiaoyu Song

Electrical and Computer Engineering Faculty Publications and Presentations

Complex and customized manufacturing requires a high level of collaboration between production and logistics in a flexible production system. With the widespread use of Internet of Things technology in manufacturing, a great amount of real-time and multi-source manufacturing data and logistics data is created, that can be used to perform production-logistics collaboration. To solve the aforementioned problems, this paper proposes a timed colored Petri net simulation-based self-adaptive collaboration method for Internet of Things-enabled production-logistics systems. The method combines the schedule of token sequences in the timed colored Petri net with real-time status of key production and logistics equipment. The key …