Engineering Commons^™

Universal Biological Motions For Educational Robot Theatre And Games, Rajesh Venkatachalapathy, Martin Zwick, Adam Slowik, Kai Brooks, Mikhail Mayers, Roman Minko, Tyler Hull, Bliss Brass, Marek Perkowski

Complex Systems Faculty Publications and Presentations

Paper presents a concept that is new to robotics education and social robotics. It is based on theatrical games, in motions for social robots and animatronic robots. Presented here motion model is based on Drift Differential Model from biology and Fokker-Planck equations. This model is used in various areas of science to describe many types of motion. The model was successfully verified on various simulated mobile robots and a motion game of three robots called "Mouse and Cheese."

Do Secondary Cyclones Increase The Category Scale Of Atmospheric Rivers?, Edgar Sanchez Fausto

University Honors Theses

Atmospheric rivers (ARs) play a crucial role in delivering precipitation worldwide. This makes them an important phenomenon for water resource specialists to study. One such interest is to understand what mechanisms make ARs produce significant rainfall and associated hazards such as flooding. One possible mechanism is that AR duration or intensity may increase when it interacts with a secondary cyclone, either of which can increase the AR category scale. The purpose of this study is to determine whether AR and secondary cyclone interactions increase the category scale ARs. Out of 52 AR events analyzed, 32 events contained at least one …

Impact Of Green And White Roofs On Air Handler Filters And Indoor Ventilation Air, Pradeep Ramasubramanian, Irvan Luhung, Serene B. Y. Lim, Stephan C. Schuster, Olyssa Starry, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Rooftop surfaces near building outdoor air intakes may contribute to the mass loading on filters and compounds emitted to ventilation air downstream of the filter. In laboratory analyses, we characterized microbial composition, primary volatile organic compound (VOC) emissions, ozone removal rates, and VOC emissions in the presence of ozone on filters collected from air handlers located on the green and white roof sections of a big-box retail store. Total DNA masses per area of filter were 26.3 ± 11.9 ng cm−2 and 6.3 ± 6.5 ng cm−2 for green and white roof filters respectively, with higher mass observed in winter …

A Method For Comparative Analysis Of Trusted Execution Environments, Stephano Cetola

Dissertations and Theses

The problem of secure remote computation has become a serious concern of hardware manufacturers and software developers alike. Trusted Execution Environments (TEEs) are a solution to the problem of secure remote computation in applications ranging from "chip and pin" financial transactions to intellectual property protection in modern gaming systems. While extensive literature has been published about many of these technologies, there exists no current model for comparing TEEs. This thesis provides hardware architects and designers with a set of tools for comparing TEEs. I do so by examining several properties of a TEE and comparing their implementations in several technologies. …

A Three-Dimensional Musculoskeletal Model Of The Dog, Heiko Stark, Martin S. Fischer, Alexander Hunt, Fletcher Young, Roger Quinn, Emanuel Andrada

Mechanical and Materials Engineering Faculty Publications and Presentations

Abstract The domestic dog is interesting to investigate because of the wide range of body size, body mass, and physique in the many breeds. In the last several years, the number of clinical and biomechanical studies on dog locomotion has increased. However, the relationship between body structure and joint load during locomotion, as well as between joint load and degenerative diseases of the locomotor system (e.g. dysplasia), are not sufficiently understood. Collecting this data through in vivo measurements/records of joint forces and loads on deep/small muscles is complex, invasive, and sometimes unethical. The use of detailed musculoskeletal models may help …

Seabed Observations At The New England Mud Patch: Reflection And Scattering Measurements And Direct Geoacoustic Information, Charles W. Holland, Chad M. Smith, Zackary Lowe, Jim Dorminy

Electrical and Computer Engineering Faculty Publications and Presentations

Seabed reflection and scattering measurements were conducted at the New England Mud Patch to better understand the acoustic properties of fine-grained (muddy) sediments. The measurement philosophy and the measurements themselves are summarized. In addition, geoacoustic information accessed directly from the data in the time and frequency domains is presented. The main result is the existence of an angle of intromission. This observation proves that the mud sound speed is less than that of the water and yields a sediment sound speed ratio 0.9865 with outer bounds {0.985 0.989}. Another result is the observation of strong scattered arrivals from within the …

Adaptive Routing Behavior With Real-Time Information Under Multiple Travel Objectives, Ravi Venkatraman, Stephen D. Boyles, Rachel James, Avinash Unnikrishnan, Priyadarshan N. Patil

Civil and Environmental Engineering Faculty Publications and Presentations

Real-time information about traffic conditions is becoming widely available through various media and connected-vehicle technology. In such conditions, travelers have better knowledge about the system and adapt as the system evolves dynamically during their travel. Drivers may change routes during their travel in order to optimize their own objective of travel. Various travel objectives are captured in mathematical models via disutility functions. The focus of this research was to study the behavior of travelers with multiple trip objectives when they are provided real-time information, and assess their ability to determine “optimal” routing policies, compared to exact solutions based on the …

Incorporating Conditional Ss-Mean Based Equity Metric In Coverage Based Facility Location Problems, Rohan Sirupa

Dissertations and Theses

A classical maximum coverage facility location problem (MCLP) tries to maximize the coverage by serving all possible demands within the specified coverage radius. Depending on the applications, several families of MCLP variants have been developed - each with its unique set of additional constraints. One specific application is locating Emergency medical service (EMS) units. EMS units such as ambulances or drones with emergency supplies are located using models such as the maximum expected survival location problem (MEXSLP). However, a classical MEXSLP model tends to locate EMS units near densely populated regions, resulting in increased response times for lowly populated regions. …

Investigations Into Size And Surface Control Of Silicon Nanocrystals For Improved Optical Properties, James Donald Barnes

Dissertations and Theses

The discovery of visible photoluminescence (PL) from nanocrystalline porous silicon in 1990 led to extensive research into the mechanisms of the emergent properties, and optimization of these properties, for use in applications. The widespread use of silicon nanoparticles (Si NPs) in commercial applications is currently limited by three main factors: 1) poor radiative recombination efficiency of the interband transition, 2) instability of the interband photoluminescence, and 3) a lack of scalable methods for producing Si NPs that are both highly crystalline and size monodisperse.

To address these limitations, this dissertation correlates changes in the photoluminescence properties of hydrogen passivated silicon …

Towards Adaptive, Self-Configuring Networked Unmanned Aerial Vehicles, Nirupama Bulusu, Ehsan Aryafar, Feng Liu

Computer Science Faculty Publications and Presentations

Networked drones have the potential to transform various applications domains; yet their adoption particularly in indoor and forest environments has been stymied by the lack of accurate maps and autonomous navigation abilities in the absence of GPS, the lack of highly reliable, energy-efficient wireless communications, and the challenges of visually inferring and understanding an environment with resource-limited individual drones. We advocate a novel vision for the research community in the development of distributed, localized algorithms that enable the networked drones to dynamically coordinate to perform adaptive beam forming to achieve high capacity directional aerial communications, and collaborative machine learning to …

Tensile Strength Evaluation Of Glulam Connection With Screw Fasteners, Bradley Sharpshair

Civil and Environmental Engineering Master's Project Reports

Multiple knife plate and external steel plate deep-beam glulam connections were investigated in a series of destructive tests within the Infrastructure Testing and Applied Research laboratory at Portland State University. The goal of these tests was to better understand the failure mode and ultimate load capacity of the large-scale glulam moment connections. Two different types of tests were performed on each connection; one with axial loading, and another loaded in flexure. The first, smaller, axial tests were conducted to inform the later, much larger, bending tests. The results of these tests helped to develop future designs as well as provide …

Sound Speed Gradients In Mud, Charles W. Holland

Electrical and Computer Engineering Faculty Publications and Presentations

Various methods have been used to estimate sound speed profiles in mud at the New England Mud Patch. Some of these methods show large sound speed gradients of order 10 s−1. New measurements of the seabed reflection coefficient exhibit an angle of intromission over three octaves in frequency; these data constrain the range of possible sound speed gradient values. The data indicate that sound speed gradients must be quite weak, i.e., much smaller than |10 s−1|. This conclusion is supported by core data which indicate nearly constant porosity in most of the mud layer.

Method Of Modeling The Swing Equation Using Time Synchronized Measurements, Robert Matthew Ferraro

Dissertations and Theses

In three phase, high-voltage transmission systems, synchronous generators accelerate or decelerate to adapt to changing power transfer requirements that occur during system disturbances. In network electrical power systems, frequency changes constantly based on system dynamics. Modeling network dynamics from oscillations and transients using time-synchronized measurements can provide real-time information, including angular displacements, voltage and current phasors, frequency changes, and rate of signal system decay from positive-sequence components.

Power system voltage and current waveforms are not steady-state sinusoids, especially during system disturbances. These waveforms contain sustained harmonic and non-harmonic components. Additionally, because of faults and other switching electromagnetic transients, there may …

Development Of A Design Guideline For Pile Foundations Subjected To Liquefaction-Induced Lateral Spreading, Milad Souri

Dissertations and Theses

Extensive loss of stiffness and strength in liquefied soils can cause large ground deformations during strong earthquake shaking. One of the major sources of damage in pile foundations in liquefied soil is the excessive deformation due to lateral spreading. Pile-supported wharves subjected to earthquake motions are expected to accommodate inertial loads imposed at pile head from the superstructure as well as the kinematic loads imposed on piles from the lateral ground deformations. Current design codes significantly vary on how to combine inertia and kinematic demands. Recent research on soil-foundation-structure interaction suffers from lack of experiment-based data. There is a serious …

A Temporal Investigation Of Crash Severity Factors In Worker-Involved Work Zone Crashes: Random Parameters And Machine Learning Approaches, Seyedmirsajad Mokhtarimousavi, Jason C. Anderson, Mohammed Hadi, Atorod Azizinamini

Civil and Environmental Engineering Faculty Publications and Presentations

In the context of work zone safety, worker presence and its impact on crash severity has been less explored. Moreover, there is a lack of research on contributing factors by time-of-day. To accomplish this, first a mixed logit model was used to determine statistically significant crash severity contributing factors and their effects. Significant factors in both models included work-zone-specific characteristics and crash-specific characteristics, where environmental characteristics were only significant in the daytime model. In addition, results from parameter transferability test provided evidence that daytime and nighttime crashes need to be modeled separately. Further, to explore the nonlinear relationship between crash …

Spectrum Modeling Of Rf Amplifiers Based On Intercept Points With Measurement Improvements, Siyuan Yan

Dissertations and Theses

Orthogonal frequency-division multiplexing has been developed into a popular modulation scheme for wireless communication systems, used in applications such as LTE and 5G. In wireless communication system, spectrum regrowth caused by RF amplifiers will generate distortions to both passband in use and adjacent channels such that the transmission quality will be degraded. The study of this dissertation aims to predict the spectrum regrowth for OFDM based signals at the output of a RF amplifier due to the nonlinearity. Based on Taylor polynomial coefficients, a power spectrum expression for amplified OFDM signals in terms of intercept points up to nth-order is …

Lagrangian Diffusion Properties Of A Free Shear Turbulent Jet, Bianca F. Viggiano, Thomas Basset, Stephen Solovitz, Thomas Barois, Mathieu Gibert, Nicolas Mordant, Laurent Chevillard, Romain Volk, Mickael Bourgoin, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

A Lagrangian experimental study of an axisymmetric turbulent water jet is performed to investigate the highly anisotropic and inhomogeneous flow field. Measurements are conducted within a Lagrangian exploration module, an icosahedron apparatus, to facilitate optical access of three cameras. Stereoscopic particle tracking velocimetry results in three-component tracks of position, velocity and acceleration of the tracer particles within the vertically oriented jet with a Taylor-based Reynolds number Reλ≃230. Analysis is performed at seven locations from 15 diameters up to 45 diameters downstream. Eulerian analysis is first carried out to obtain critical parameters of the jet and relevant scales, namely the Kolmogorov …

On Compressional Wave Attenuation In Muddy Marine Sediments, Charles W. Holland, Stan E. Dosso

Electrical and Computer Engineering Faculty Publications and Presentations

A method for measuring in situ compressional wave attenuation exploiting the spectral decay of reflection coefficient Bragg resonances is applied to fine-grained sediments in the New England Mud Patch. Measurements of layer-averaged attenuation in a 10.3 m mud layer yield 0.04 {0.03, 0.055} dB/m/kHz (braces indicate outer bounds); the attenuation is twice as large at a site with 3.2 m mud thickness. It is shown that both results are heavily influenced by a ∼1 m sand-mud transition interval created by geological and biological processes that mix sand (at the base of the mud) into the mud. Informed by the observations, …

A Golden Age For Computing Frontiers, A Dark Age For Computing Education?, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

There is no doubt that the body of knowledge spanned by the computing disciplines has gone through an unprecedented expansion, both in depth and breadth, over the last century. In this position paper, we argue that this expansion has led to a crisis in computing education: quite literally the vast majority of the topics of interest of this conference are not taught at the undergraduate level and most graduate courses will only scratch the surface of a few selected topics. But alas, industry is increasingly expecting students to be familiar with emerging topics, such as neuromorphic, probabilistic, and quantum computing, …

Measuring Pedestrian Level Of Stress In Urban Environments: Naturalistic Walking Pilot Study, Seth Lajeunesse, Paul Ryus, Wesley Kumfer, Sirisha Kothuri, Krista Nordback

Civil and Environmental Engineering Faculty Publications and Presentations

Walking is the most basic and sustainable mode of transportation, and many jurisdictions would like to see increased walking rates as a way of reducing congestion and emission levels and improving public health. In the United States, walking trips account for 10.5% of all trips undertaken. To increase this rate, additional research on what makes people feel more comfortable while walking is needed. Research on pedestrian quality of service (QOS) has sought to quantify the performance of the pedestrian facilities from a pedestrian’s perspective. However, the impact of pedestrian safety countermeasures on pedestrian QOS for roadway crossings is largely unknown. …

Quantification Of Wake Shape Modulation And Deflection For Tilt And Yaw Misaligned Wind Turbines, Juliaan Bossuyt, Ryan Scott, Naseem Ali, Raul Bayoan Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

Misaligned wind turbine rotors redirect the wake, and manipulate the wake shape by introducing a counter-rotating vortex pair. This mechanism is of great interest for improving wind farm power output through static or dynamic misalignment. In this study, cross-plane stereo-particle image velocimetry measurements are used to characterize the wake evolution for tilt misalignment and verify differences with yaw misalignment. Blockage from the ground, shear in the velocity profile, turbulence levels, hub-vortices and tip-vortices are found to strongly affect wake evolution for a tilted wind turbine resulting in a non-symmetric behaviour for upwards deflecting or downwards deflecting tilt. The downwards deflection …

Using Information Theory To Extract Patterns From Categorical Raster Data, David Percy

Complex Systems Faculty Publications and Presentations

Information theory -- Reconstructability Analysis (RA) implemented in the Occam software -- was used to extract patterns from National Land Cover Data. The aim was to predict temporal change in evergreen forests from time-lagged and spatially adjacent states. The NLCD satellite data were preprocessed with Python and submitted to Occam for analysis, and Occam output was also explored with R-studio. The effectiveness of RA methodology for the analysis of this type of categorical space-time grid data was demonstrated.

Modeling Tools For Analyzing Electrical Power Distribution Systems Impacted By Electric Vehicle Load Growth, Jacob Sheeran

Dissertations and Theses

Growing Electric Vehicle penetration presents unwanted problems to grid reliability. For nearly every EV there is corresponding household charging. High penetration of Electric Vehicle Service Equipment can lead to over loading of assets and under voltage conditions. In order to understand the effects EV have on a distribution system, studies have to be done for EVSE to understand how the distribution system is affected. Using advanced Power Engineering Simulation Software is often the best way to model systems due to the credibility of their software modules. For this thesis, I developed a suite of distribution system analysis tools using CYME …

The Green Synthesis Of 2d Copper Nanosheets And Their Light Absorption, Suhyun Lee, Suming Wang, Chien Wern, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

In this study, a new green synthesis method for two-dimensional (2D) copper nanosheets is developed using methylsulfonylmethane (DMSO₂). The chemical composition and light absorption of 2D copper nanosheets are also studied. A new green method is mainly to utilize DMSO₂, which is environmentally friendly enough to be considered a food-grade chemical, unlike the conventional method using toxic chemicals, such as ammonia and hydrazine (N₂H₄). With a reducing agent, the aggregation of uncertain copper products was produced in the absence of DMSO₂, while 2D copper nanosheets were formed in the presence …

Distributionally Robust Optimization Utilizing Facility Location Problems, Elijah Kling

Civil and Environmental Engineering Undergraduate Honors Theses

Facility location problems are used in widespread application in transportation, freight, supply chain, and logistics problems. Models can be developed as deterministic, where all parameters are known, or robust, where a parameter has uncertainty. This thesis explores a new method for developing robust formulation and compares the implications of assuming values for this uncertain parameter. Two models are solved, and both are compared against their deterministic counterparts using numerical analysis. By manipulating the input parameters and considering real world implications of the solutions, either the robust or deterministic can show better performance.

The Critical Energy Infrastructure (Cei) Hub: A Look Into The Seismic Fragility Of Oregon’S Fuel, Annecy Bal

Civil and Environmental Engineering Undergraduate Honors Theses

This research evaluates the seismic vulnerability of the Critical Energy Infrastructure (CEI) Hub and the associated fuel repercussions for the expected 9.0 magnitude earthquake along the Cascadia Subduction Zone. The tanks in the CEI hub are analyzed based on size and content. The owners and secondary containment areas are discussed using the same parameters. Various analysis techniques are reviewed to determine the most appropriate seismic fragility estimate for the site. The seismic vulnerability is analyzed using fragility curves by Hazus, American Lifeline Alliance, and D'Amico. The fragility curves are applied to the CEI Hub to determine expected damage and the …

Cei Hub Failure Following A Cascadia Earthquake Event: Preliminary Modeling Of A Liquid Fuel Spill In The Lower Willamette And Columbia Rivers, Mike Du Bose

Civil and Environmental Engineering Undergraduate Honors Theses

The Critical Energy Infrastructure (CEI) Hub in Northwest Portland, OR spans a six-mile stretch of the Lower Willamette River and stores 90% of Oregon’s liquid fuel supply and 100% of the jet fuel for PDX. The CEI Hub is also built entirely on liquefiable soils which are likely to fail during a Cascadia earthquake event. The purpose of this project was to model a liquid fuel spill in the Lower Willamette and Columbia Rivers using the CE-QUAL-W2 model. Several scenarios were developed to account for different environmental conditions, (e.g., high and low discharge years) and varying spill durations (e.g., rapid …

The Influence Of Channel Deepening On Tides, River Discharge Effects, And Storm Surge, Stefan A. Talke, Ramin Familkhalili, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

We combine archival research, semi-analytical models, and numerical simulations to address the following question: how do changes to channel geometry alter tidal properties and flood dynamics in a hyposynchronous, strongly frictional estuary with a landward decay in tidal amplitudes? Records in the Saint Johns River Estuary since the 1890s show that tidal range has doubled in Jacksonville, Florida. Near the estuary inlet, tidal discharge approximately doubled but tidal amplitudes increased only ~6%. Modeling shows that increased shipping channel depths from 5-6 to ~13m drove the observed changes, with other factors like channel shortening and width reduction producing comparatively minor effects. …

Maximum Coverage Facility Location Drone Routing Problem With Multiple Trip Stops, Marie Roza

Civil and Environmental Engineering Undergraduate Honors Theses

Integer linear optimization can be used to formulate routing problems as models to find optimal solutions given a set of inputs and constraints. In this research, Chauhan et al.'s publication, "Maximum coverage capacitated facility location problem with range constrained drones," is expanded upon by modeling a facility location problem with two-to-one drone deliveries. The model analyzes a set of potential facilities that are available to meet the demands of a set of demand points. The drone delivery routes are modeled with the assumption that each opened facility is assigned one drone that can fulfill up to two demand points’ demands …

A Comparison Of Particulate Matter Deposition Onto Green Roof Species And White Roof In Portland, Oregon, Amelia Drake

University Honors Theses

This study explores the following question: how do different green roof vegetation species contribute to particulate matter deposition relative to a white roof in Portland, Oregon? To answer this question, rinse water from two species of vegetation and rinse water from a white roof were filtered to measure the mass of particles found on these leaves. Leaf area was then determined in order to calculate the density of particles found on each surface. The resulting conclusions from this process clearly indicate that a larger density of particles collected on vegetative surfaces as opposed to the surface of the white roof. …