Engineering Commons^™

Sensitivity Analysis Of An Agent-Based Simulation Model Using Reconstructability Analysis, Andey M. Nunes, Martin Zwick, Wayne Wakeland

Systems Science Faculty Publications and Presentations

Reconstructability analysis, a methodology based on information theory and graph theory, was used to perform a sensitivity analysis of an agent-based model. The NetLogo BehaviorSpace tool was employed to do a full 2^k factorial parameter sweep on Uri Wilensky’s Wealth Distribution NetLogo model, to which a Gini-coefficient convergence condition was added. The analysis identified the most influential predictors (parameters and their interactions) of the Gini coefficient wealth inequality outcome. Implications of this type of analysis for building and testing agent-based simulation models are discussed.

Examining Bicycle And Motorized Vehicle Speeds And Their Relationships In The Context Of Urban Roadways, Jaclyn Sue Schaefer

Dissertations and Theses

This thesis presents a compilation of papers exploring passenger car and bicycle speeds through their interactions with each other and with urban roadway factors.

First, following a concern raised in part of the traffic literature that a large mode shift toward bicycling may cause travel time delays and potentially exacerbate congestion instead of alleviate it unless bicycle lanes are installed, an empirical study detailing how the presence of bicycles on urban roads without bicycle lanes may affect passenger car speeds is presented. Pneumatic tube data from six predominantly low speed, low volume roads in Portland, Oregon were utilized to identify …

Relationships Between In-Situ Tests And Soil Cyclic Strength For Earthquake Hazard Characterization In The Pacific Northwest, Tanner Scott Bryantt

Dissertations and Theses

Strong earthquake shaking is a natural hazard threat in the Pacific Northwest. Soil failure due to strong earthquake shaking -- known as cyclic soil failure or liquefaction -- is expected to cause large ground deformations and damage to roads, bridges, and other civil infrastructure. Cyclic soil strength (CRR) is often characterized with in-situ geotechnical tests including the cone penetration test (CPT). Relationships between CRR and in-situ test data are not well established for soils in the Pacific Northwest. Portland State University, in partnership with New Albion Geotechnical has compiled a database of cyclic lab tests for Pacific Northwest soils to …

Vessel Trajectory Prediction Using Historical Ais Data, Jagir Laxmichand Charla

Dissertations and Theses

Maritime vessel position coordinates are important information for maritime situational planning and organization. A better estimate of future locations of the maritime vessels, from their current locations, can help maritime authorities to make planned decisions, which can be helpful to avoid traffic congestion and longer waiting times. This thesis develops a method for estimating future locations of the vessels using their current and previous locations and other data.

The motivating scenario for this work is that of determining the future locations of the vessels based on their current location and previous locations for accurate modelling of underwater acoustic noise. As …

Clustered Hyperspectral Target Detection, Sean Onufer Stalley

Dissertations and Theses

Aerial target detection is often used to search for relatively small things over large areas of land. Depending on the size and signature of the target, detection can be a very easy or very difficult task. By capturing images with several hundred color channels, hyperspectral sensors provide a new way of looking at this task, both literally and figuratively. Hyperspectral sensors can be used in many aerial target detection tasks such as identifying unhealthy trees in a forest, searching for minerals at a mining site, or finding the sources of chemical leaks at a factory. The high spectral resolution of …

Achieving High Reliability Organizations Using Fuzzy Cognitive Maps - The Case Of Offshore Oil And Gas, Ahmed A. Alibage

Dissertations and Theses

The safety culture of so-called high-reliability organizations (HROs) encompasses values, routines, and work processes that allow an organization to prevent mistakes and quickly bounce back if unexpected events occur. It is said to provide a model for improving organizational resilience in the offshore oil and gas industry, where small errors can grow into accidents with devastating environmental, social, and economic impacts. To date, such a transfer of successful practices is impeded by a lack of system perspective that would allow researchers and practitioners to fully understand the safety dynamics in HROs, adjust them to the unique setting of offshore oil …

Entrainment Processes For A Jet In Cross-Flow: The Quantification Of Turbulent Contributions And Their Importance On Accurate Modeling, Graham Asher Freedland

Dissertations and Theses

A jet in cross flow (JICF) is examined experimentally by injecting a stream of air into crossing fluid with an aim into quantifying entrainment process and downstream evolution. The behavior of JICF is important to fields ranging from turbine-blade cooling to smokestack pollution and volcanic eruption dynamics. Existing simplified volcanic plume models are tested; most importantly, the near-field contributions of complex interconnected vortex systems, which present significant uncertainties because they assume negligible turbulence. While jets in irrotational cross-flow have been investigated, this analysis has focused on the interaction between a turbulent jet in low and highly turbulent cross-flow created by …

Virtual Head Waves In Ocean Ambient Noise: Theory And Modeling, Jie Li, Peter Gerstoft, Martin Siderius, Jun Fan

Electrical and Computer Engineering Faculty Publications and Presentations

The Green's function retrieval in media with horizontal boundaries usually only considers the extraction of direct and reflected waves but ignores the virtual head waves, which have been observed experimentally from ocean ambient noise and used to invert for geometric and environmental parameters. This paper derives the extraction of virtual head waves from ocean ambient noise using a vertically spaced sensor pair in a Pekeris waveguide. Ocean ambient noise in the water column is a superposition of direct, reflected, and head waves. The virtual head waves are produced by the cross-correlations between head waves and either reflected waves or other …

Robust Maximum Coverage Facility Location Problem With Drones Considering Uncertainties In Battery Availability And Consumption, Darshan Chauhan, Avinash Unnikrishnan, Miguel Figliozzi, Stephen D. Boyles

Civil and Environmental Engineering Faculty Publications and Presentations

Given a set of spatially distributed demand for a specific commodity, potential facility locations, and drones, an agency is tasked with locating a prespecified number of facilities and assigning drones to them to serve the demand while respecting drone range constraints. The agency seeks to maximize the demand served while considering uncertainties in initial battery availability and battery consumption. The facilities have a limited supply of the commodity being distributed and also act as a launching site for drones. Drones undertake one-to-one trips (from located facility to demand location and back) until their available battery energy is exhausted. This paper …

Tensile Behavior Of Frp Anchors Made From Cfrp Ropes Epoxy-Bonded To Uncracked Concrete For Flexural Strengthening Of Rc Column, Yasir Saeed, Wisam Amer Aules, Franz N. Rad, Anis M. Raad

Civil and Environmental Engineering Faculty Publications and Presentations

One of the major problems with using fiber reinforced polymer (FRP) in strengthening reinforced concrete (RC) structures is FRP premature debonding. Anchoring FRP materials to concrete has become associated with most of the strengthening techniques. One of the anchoring techniques is using handmade anchors made from FRP materials. In previous studies, most FRP anchors were made from rolling pre-cut FRP sheets and had short embedment (mm) as they were used for flexural or shear strengthening of RC beams. In the present study, FRP anchors were made from carbon fiber reinforced polymer (CFRP) ropes and had long embedment to be used …

Methodologies To Quantify Transit Performance Metrics At The System-Level Using High-Resolution Gps, Stop-Level, And Gtfs Archived Transit Data, Travis Bradley Glick

Dissertations and Theses

Performance metrics have typically focused at two main scales: a microscopic scale that focuses on specific locations, time-periods, and trips; and, a macroscopic scale that averages metrics over longer times, entire routes, and networks. When applied to entire transit systems, microscopic methodologies often have computational limitations while macroscopic methodologies ascribe artificial uniformity to non-uniform analysis areas. These limitations highlight the need for a middle approach.

This dissertation presents a mesoscopic analysis based around timepoint-segments, which are a novel application of an existing system for many transit agencies. For this research, routes are divided into a consecutive group of bus stops …

Use Of Carbon Fiber Reinforced Polymer (Cfrp) Including Sheets, Rods, And Ropes In Strengthening And Repairing Long Reinforced Concrete Columns, Yasir Matloob Saeed

Dissertations and Theses

The use of FRP materials in strengthening and repairing of reinforced concrete (RC) structures has increased in the past two decades. Recently, FRP materials have become one of the most used materials in rehabilitation engineering. For seismic retrofitting of RC structures, usually the process involves strengthening or repairing the vertical support elements of the buildings or bridges. Several studies focused on the use of FRP materials in strengthening and repairing RC columns. Externally bonded (EB) FRP sheets or laminates and near-surface-mounted (NSM) FRP rods have been used for enhancing the strength and ductility of RC columns. Although glass FRP (GFRP) …

Distributed Energy Resource Aggregation Using Customer-Owned Equipment: A Review Of Literature And Standards, Manasseh Obi, Tylor Slay, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Large-scale deployment of renewable energy resources, both utility-scale and distributed, create reliability concerns for electrical power system operators. The weather-dependent, non-dispatchable nature of renewable resources decreases the ability of operators to match supply with demand. Concurrently, distributed energy resources, defined as small-scale loads, generation sources, and storage systems, are becoming ubiquitous within modern electrical systems. This literature review presents the grid services that utilities use to alleviate power systems reliability concerns, particularly those caused by renewable resources, and how aggregations of residential-scale distributed energy resources can be used to provide these services.

By aggregating distributed energy resources en masse to …

Extending The Functional Subnetwork Approach To A Generalized Linear Integrate-And-Fire Neuron Model, Nicholas Szczecinski, Roger Quinn, Alexander J. Hunt

Mechanical and Materials Engineering Faculty Publications and Presentations

Engineering neural networks to perform specific tasks often represents a monumental challenge in determining network architecture and parameter values. In this work, we extend our previously-developed method for tuning networks of non-spiking neurons, the “Functional subnetwork approach” (FSA), to the tuning of networks composed of spiking neurons. This extension enables the direct assembly and tuning of networks of spiking neurons and synapses based on the network’s intended function, without the use of global optimization ormachine learning. To extend the FSA, we show that the dynamics of a generalized linear integrate and fire (GLIF) neuronmodel have fundamental similarities to those of …

Characterization And Manipulation Of Carbon Precursor Species During Plasma Enhanced Chemical Vapor Deposition Of Graphene, Otto Zietz, Samuel Olson, Brendan Coyne, Yilian Liu, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

To develop a synthesis technique providing enhanced control of graphene film quality and uniformity, a systematic characterization and manipulation of hydrocarbon precursors generated during plasma enhanced chemical vapor deposition of graphene is presented. Remote ionization of acetylene is observed to generate a variety of neutral and ionized hydrocarbon precursors, while in situ manipulation of the size and reactivity of carbon species permitted to interact with the growth catalyst enables control of the resultant graphene morphology. Selective screening of high energy hydrocarbon ions coupled with a multistage bias growth regime results in the production of 90% few-to-monolayer graphene on 50 nm …

A Simplified Accuracy Enhancement To The Saleh Am/Am Modeling And Linearization Of Solid-State Rf Power Amplifiers, Haider Al-Kanan, Fu Li

Electrical and Computer Engineering Faculty Publications and Presentations

The Saleh behavioral model exhibits high prediction accuracy for nonlinearity of traveling-wave tube power amplifiers (TWT-PAs). However, the accuracy of the Saleh model degrades when modeling solid-state power amplifiers (SSPAs) technology. In addition, the polynomial expansion of the Saleh model consists of only odd-order terms as analyzed in this work. This paper proposes a novel model accuracy enhancement for the Saleh amplitude-to-amplitude (AM/AM) model when applied to radio frequency (RF) SSPAs. The proposed model enhancement accounts for the second-order intermodulation distortion, which is an important nonlinearity challenge in wideband wireless communications. The proposed static AM/AM model is a three-parameter rational …

Flight Simulator Modeling Using Recurrent Neural Networks, Nickolas Sabatini, Andreas Natsis

Undergraduate Research & Mentoring Program

Recurrent neural networks (RNNs) are a form of machine learning used to predict future values. This project uses RNNs tor predict future values for a flight simulator. Coded in Python using the Keras library, the model demonstrates training loss and validation loss, referring to the error when training the model.

From Inductive To Deductive Learning, Mikhail Mayers, Brian Henson

Undergraduate Research & Mentoring Program

Using Machine Vision as a way to give information to Prolog. Using Prolog to solve deductive problems and analogical problems without having to manually enter all facts and information.

Rapid Repair Of Seismically Vulnerable Bridge Columns Following Earthquake Induced Damage, Gregory H. Norton

Civil and Environmental Engineering Master's Project Reports

The Cascadia Subduction Zone (CSZ) earthquake has a high probability of occurrence within our lifetime, threatening bridges across the Pacific Northwest. Damage is expected to be geographically spread throughout the region and will have a nearly simultaneous impact on transportation through several important corridors. While bridge repair and replacement will ultimately be needed, priority will be placed on resuming mobility such that repairs will need to be implemented quickly. In an effort to anticipate this need, a repair method is being developed for rapid repair with the goal of achieving semi-permanent installation that also considers the different bridge damage states …

Effect Of Bout Length On Gait Measures In People With And Without Parkinson’S Disease During Daily Life, Vrutangkumar Shah, James Mcnames, Graham Harker, Martina Mancini, Patricia Carlson-Kuhta, John G. Nutt, Mahmoud El-Gohary, Carolin Curtze, Fay Horak

Electrical and Computer Engineering Faculty Publications and Presentations

Although the use of wearable technology to characterize gait disorders in daily life is increasing, there is no consensus on which specific gait bout length should be used to characterize gait. Clinical trialists using daily life gait quality as study outcomes need to understand how gait bout length affects the sensitivity and specificity of measures to discriminate pathological gait as well as the reliability of gait measures across gait bout lengths. We investigated whether Parkinson’s disease (PD) affects how gait characteristics change as bout length changes, and how gait bout length affects the reliability and discriminative ability of gait measures …

An Equity Focused Study On The Trip Temporal Distributions Of Vulnerable Road Users, Santiago Espinosa Wild

Civil and Environmental Engineering Master's Project Reports

The United States is a megadiverse nation with a transportation system that, for decades, was designed to serve primarily able-bodied, white, male motorists. This legacy creates a situation in which varying socio-demographic groups experience the transportation system differently with contrasting safety, accessibility, and convenience outcomes. This project introduces descriptive statistics and binary logistic models that provide transportation professionals and policy makers with a quantitative understanding on how, why, and when certain socio-demographic groups are more likely to engage in a trip. This project provides tools to measure and understand the equity implications of a wide array of transportation policy decisions. …

Modeling Airflows And Voc Source Strengths For An Occupied School, Brett Stinson

University Honors Theses

Volatile organic compounds (VOCs) are a group of air pollutants that can adversely impact human health, engage in chemistry indoors, and meaningfully degrade indoor and outdoor urban air quality. While extensive research with regard to VOC emission rates from indoor sources has been conducted, it was not until recently that this work began to focus on characterizing emissions from humans and human activity in depth. As buildings are constructed to be increasingly airtight, and the materials utilized are chosen to reduce VOC emissions, it follows that human contributions are poised to become increasingly important indoor sources of VOCs. Utilizing data …

The Seasonal Effects Of Photovoltaic Cells On Sedum Eco Roof Substrate Moisture, Brook M. Thompson

University Honors Theses

This paper investigates a combined PV eco roof system and analyzes the soil moisture levels in front of the panels and directly underneath the PV Cells on an experimental ecoroof platform in Portland, Oregon. The purpose of the study was to examine how PV Cells create differences in the moisture level of the soil on the ecoroof. Four moisture sensors were set in different quadrants in four experimental testbeds, and the moisture level data was recorded from October 18^th, 2018 to September 10^th, 2019. The study found that in with heavy rainfall, the front of the …

Applying The Principle Of Least Privilege To System Management Interrupt Handlers With The Intel Smi Transfer Monitor, Brian Delgado, Tejaswini Vibhute, Karen L. Karavanic

Computer Science Faculty Publications and Presentations

Recent years have seen a growing concern over System Management Mode (SMM) and its broad access to platform resources. The SMI Transfer Monitor (STM) is Intel’s most powerful executing CPU context. The STM is a firmware-based hypervisor that applies the principle of least privilege to powerful System Management Interrupt (SMI) handlers that control runtime firmware. These handlers have traditionally had full access to memory as well as the register state of applications and kernel code even when their functionality did not require it. The STM has been been enabled for UEFI and, most recently, coreboot firmware, adding protection against runtime …

Approximate Pattern Matching Using Hierarchical Graph Construction And Sparse Distributed Representation, Aakanksha Mathuria

Dissertations and Theses

With recent developments in deep networks, there have been significant advances in visual object detection and recognition. However, some of these networks are still easily fooled/hacked and have shown "bag of features" kinds of failures. Some of this is due to the fact that even deep networks make only marginal use of the complex structure that exists in real-world images. Primate visual systems appear to capture the structure in images, but how?

In the research presented here, we are studying approaches for robust pattern matching using static, 2D Blocks World images based on graphical representations of the various components of …

Indoor Air Quality Impacts Of A Woodstove Exchange Program In Washington County, Oregon, Matthew Forrest Survilo

Dissertations and Theses

More than six million people in the United States use wood stoves as their primary heat source. Wood stoves emit air pollutants that may impact health, e.g., wood combustion products are associated with premature death and aggravation of pulmonary and cardiovascular conditions. There are few studies investigating the efficacy of wood stove exchange programs (WSEPs) as a method to improve indoor air quality (IAQ). In partnership with Washington County Department of Health and Human Services we conducted an air quality study to measure the impact of a WSEP on indoor and neighborhood levels of wood combustion products. Twenty households engaged …

3d-Printed Leg Design And Modification For Improved Support On A Quadruped Robot, Jasmin S. Collins

Undergraduate Research & Mentoring Program

The Agile and Adaptive Robotics Lab aims to uncover the biological and physiological complexities in animal agility and adaptive control, which can be replicated through robotics and provide further applications in biology and medicine. One project within the lab focuses on understanding structure, actuation, and control through the modeling of a canine quadruped robot.

The AARL has developed a full-body quadruped robot with artificial muscles that control limb movement and a body that is built from 3D-printed parts. This specific project involved modification of these existing parts to (a) minimize deflections in the front legs, causing unwanted lateral and abduction/adduction …

Theoretical And Experimental Validation Of A Cubesat's L-Band Communication System, Evangelos Mastrogiannis

Dissertations and Theses

An L-band uplink communication system was designed and validated in the lab for a CubeSat satellite operating in low Earth orbit (LEO). This paper investigates communication link analysis, discusses the design strategy for an inexpensive CubeSat receiver operating in L-band with a moderate power Earth station transmitter, and validates the link budget with prototype hardware using an anechoic chamber.

A receiver's required carrier-to-noise ratio (CNR) establishes the basis for a link budget. The requirement for a digital communication link is set by the bit-error-rate (BER) requirement of a chosen communication protocol which is inversely related to the energy per bit …

Analog Statistical Design For Manufacturability, Yu-Shan Wang

Dissertations and Theses

The manufacturing yield, overkill, and defect level limit the feasibility of analog circuits in SoCs. The conventional method of handling process and environmental variation is to assign a design margin such that the design meets specifications at several processes and environmental corners. However, checking only extreme corners limits performance in comparison to the more rigorous statistical approach of the computing manufacturing and quality figure of merit. The statistical approach requires transistor-level simulation of hundreds or even thousands of samples, not just a few corners, and thus is very time consuming.

This research offers a method for reducing the time required …

A Scoring Model To Evaluate Offshore Oil Projects: Case Of Eni And Mellitah Oil & Gas, Abdulhakim Giadedi

Dissertations and Theses

Offshore oil projects have many different and unique characteristics, such as larger project size, higher number of scopes, and higher complexity. In fact, offshore oil projects described as mega projects are ones that require significant assessment and acquisition methods in order to reduce risks and failures. Traditionally, cash flow analysis and return on investment are the most known factors to evaluate offshore oil projects. However, there are several other internal and external factors that affect the overall performance of offshore oil projects. A comprehensive approach and advanced tools are required to evaluate these factors that can have a significant impact …