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Engineering Commons

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2019

Portland State University

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Articles 1 - 30 of 69

Full-Text Articles in Engineering

A Review Of Integrated Propulsion, Suspension And Guidance Passive Guideway Maglev Technologies, Jonathan Bird Dec 2019

A Review Of Integrated Propulsion, Suspension And Guidance Passive Guideway Maglev Technologies, Jonathan Bird

Electrical and Computer Engineering Faculty Publications and Presentations

This paper provides a review of integrated propulsion, suspension and guidance maglev technology that use fully passive guideway structures.


Transmission-Scale Battery Energy Storage Systems: A Systematic Literature Review, Kevin Marnell, Manasseh Obi, Robert B. Bass Dec 2019

Transmission-Scale Battery Energy Storage Systems: A Systematic Literature Review, Kevin Marnell, Manasseh Obi, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

When the transmission capacity of an electrical system is insufficient to adequately serve customer demand, the transmission system is said to be experiencing congestion. More transmission lines can be built to increase capacity. However, transmission congestion typically only occurs during periods of peak demand, which occur just a few times per year; capitol-intensive investments in new transmission capacity address problems that occur infrequently. Alternative solutions to alleviated transmission congestion have been devised, including generation curtailment, demand response programs, and various remedial action schema. Though not currently a common solution, battery energy storage systems can also provide transmission congestion relief. Technological ...


Investigating The Accuracy Of One-Dimensional Volcanic Plume Models Using Laboratory Experiments And Field Data, James S. Mcneal, Graham Freedland, L. G. Mastin, Raúl Bayoán Cal, S. A. Solovitz Nov 2019

Investigating The Accuracy Of One-Dimensional Volcanic Plume Models Using Laboratory Experiments And Field Data, James S. Mcneal, Graham Freedland, L. G. Mastin, Raúl Bayoán Cal, S. A. Solovitz

Mechanical and Materials Engineering Faculty Publications and Presentations

During volcanic eruptions, model predictions of plume height are limited by the accuracy of entrainment coefficients used in many plume models. Typically, two parameters are used, 𝛼 and 𝛽, which relate the entrained air speed to the jet speed in the axial and cross-flow directions, respectively. To improve estimates of these parameters, wind tunnel experiments have been conducted for a range of cross-wind velocities and turbulence conditions. Measurements are compared directly to computations from the 1-D plume model, Plumeria, in the near-field, bending region of the jet. Entrainment coefficients are determined through regression analysis, demonstrating optimal combinations of effective 𝛼 ...


Contamination Of Coupling Glass And Performance Evaluation Of Protective System In Vacuum Laser Beam Welding, Yongki Lee, Jason Cheon, Byung-Kwon Min, Cheol-Hee Kim Nov 2019

Contamination Of Coupling Glass And Performance Evaluation Of Protective System In Vacuum Laser Beam Welding, Yongki Lee, Jason Cheon, Byung-Kwon Min, Cheol-Hee Kim

Mechanical and Materials Engineering Faculty Publications and Presentations

Vacuum laser beam welding enables deeper penetration depth and welding stability than atmospheric pressure laser welding. However, contaminated coupling glass caused by welding fumes in the vacuum space reduces laser transmittance, leading to inconsistent penetration depth. Therefore, a well-designed protective system is indispensable. Before designing the protective system, the contamination phenomenon was quantified and represented by a contamination index, based on the coupling glass transmittance. The contamination index and penetration depth behavior were determined to be inversely proportional. A cylindrical protective system with a shielding gas supply was proposed and tested. The shielding gas jet provides pressure-driven contaminant suppression and ...


Nineteenth-Century Tides In The Gulf Of Maine And Implications For Secular Trends, Richard D. Ray, Stefan A. Talke Oct 2019

Nineteenth-Century Tides In The Gulf Of Maine And Implications For Secular Trends, Richard D. Ray, Stefan A. Talke

Civil and Environmental Engineering Faculty Publications and Presentations

Since the early twentieth century, the amplitudes of tidal constituents in the Gulf of Maine and Bay of Fundy display clear secular trends that are among the largest anywhere observed for a regional body of water. The M2 amplitude at Eastport, Maine, increased at a rate of 14.1 ± 1.2 cm per century until it temporarily dropped during 1980–1990, apparently in response to changes in the wider North Atlantic. Annual tidal analyses indicate M2 reached an all‐time high amplitude last year (2018). Here we report new estimates of tides derived from nineteenth century water‐level measurements found ...


Paints-R-Us Term Project, Tyler Campbell, Skye Gilbreth, Michael Oluwole, Elijah Raffo, Brad Unruh Oct 2019

Paints-R-Us Term Project, Tyler Campbell, Skye Gilbreth, Michael Oluwole, Elijah Raffo, Brad Unruh

Engineering and Technology Management Student Projects

This project will consider a linear product mix optimization problem for a fictional paint company, Paints-R-Us. Paints-R-Us is a wholesale paint manufacturer located in the Pacific Northwest. The Global Production Manager, Steve Brush, has been tasked with maximizing Paints-R-Us’s profit in the upcoming quarter. Steve Brush oversees the global production plan, and in collaboration with the production planners will develop a production plan which optimizes the profits that Paints-R-Us can create in the quarter accounting for the following criteria:

• Demand in the given quarter for each of the 5 paint types that Paints-R-Us produces • The warehousing storage capacity for ...


E-Grocery Home Delivery Impacts On Food Distribution, Access And Equity: A Portland Case Study, Miguel Figliozzi, Katherine Keeling Oct 2019

E-Grocery Home Delivery Impacts On Food Distribution, Access And Equity: A Portland Case Study, Miguel Figliozzi, Katherine Keeling

Civil and Environmental Engineering Faculty Publications and Presentations

The adoption of e-grocery home delivery (HD) has the potential to change social norms of acquiring household foods and sundries. This case study of Portland, OR reviews the new elements of distribution, inclusion, exclusion, and value created by the service of four major e-grocery businesses: Shipt, Instacart, Amazon Prime Now, and Walmart. These e-grocers are reviewed in terms of service areas, pricing, and inventory choice, as these are key factors on consumer experience. New distribution services are not confided or distributed around traditional industrial or wholesale land use areas. Coverage is extensive, in the Portland metropolitan statistical area, 94% of ...


Environmental Information Content Of Ocean Ambient Noise, Martin Siderius, John Thomas Gebbie Sep 2019

Environmental Information Content Of Ocean Ambient Noise, Martin Siderius, John Thomas Gebbie

Electrical and Computer Engineering Faculty Publications and Presentations

In recent years, methods have been developed to estimate a variety of environmental parameters based on measurements of the ocean ambient noise. For example, noise has been used to estimate water depth using the passive fathometer technique and bottom loss estimated and used to invert for seabed parameters. There is also information in the noise about the water column sound speed, volume attenuation, and the sea-state. The Fisher information can be used to quantify the basic information available in the noise measurements and its inverse, the Cramér–Rao lower bound (CRLB), provides the lower limit on the variance of an ...


Hydrodynamic And Total Dissolved Solids Model Of The Tigris River Using Ce-Qual-W2, Muhanned D. Al-Murib, Scott Wells Sep 2019

Hydrodynamic And Total Dissolved Solids Model Of The Tigris River Using Ce-Qual-W2, Muhanned D. Al-Murib, Scott Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The headwaters of the Tigris River basin in Iraq is controlled by Turkey due to a series of dams constructed over the last few decades. Since Total Dissolved Solids (TDS) in the Tigris River within Baghdad and downstream cities can reach 1000 mg/L exceeding both drinking water and irrigation guidelines, a hydrodynamic and water quality model, CE-QUAL-W2, of the river was developed to understand how changes in flow affect TDS downstream. A model of 880 km of the Tigris River from Mosul Dam to Kut Barrage including Tharthar Lake was constructed for 2009. Model development was challenging due to ...


Historical Changes In Lower Columbia River And Estuary Floods: A Numerical Study, Lumas Helaire, Stefan Talke, David A. Jay, Andrew Mahedy Sep 2019

Historical Changes In Lower Columbia River And Estuary Floods: A Numerical Study, Lumas Helaire, Stefan Talke, David A. Jay, Andrew Mahedy

Civil and Environmental Engineering Faculty Publications and Presentations

Over the past 150 years, the Lower Columbia River Estuary controlling depth has approximately doubled, the majority of historical wetlands and floodplain have been reclaimed, numerous infrastructure projects have altered and confined flow pathways, and significant natural and anthropogenic changes to the discharge hydrograph have occurred. To investigate the effect of these changes on tides, river slope, and flood water levels, we construct and validate numerical models that simulate flow over late nineteenth‐century and present‐day bathymetry. The models are validated using archival (1853–1877) and modern tide measurements throughout the Lower Columbia River Estuary and river stage measurements ...


Toward Realistic Nonstationarity Of Semidiurnal Baroclinic Tides In A Hydrodynamicmodel, Arin D. Nelson, Brian K. Arbic, Edward Zaron, Anna Savage, James G. Richman, Maarten C. Buijsman, Jay F. Shriver Aug 2019

Toward Realistic Nonstationarity Of Semidiurnal Baroclinic Tides In A Hydrodynamicmodel, Arin D. Nelson, Brian K. Arbic, Edward Zaron, Anna Savage, James G. Richman, Maarten C. Buijsman, Jay F. Shriver

Civil and Environmental Engineering Faculty Publications and Presentations

Semidiurnal baroclinic tide sea surface height (SSH) variance and semidiurnal nonstationary variance fraction (SNVF) are compared between a hydrodynamic model and altimetry for the low- to middle-latitude global ocean. Tidal frequencies are aliased by ∼10-day altimeter sampling, which makes it impossible to unambiguously identify nonstationary tidal signals from the observations. In order to better understand altimeter sampling artifacts, the model was analyzed using its native hourly outputs and by subsampling it in the same manner as altimeters. Different estimates of the semidiurnal nonstationary and total SSH variance are obtained with the model depending on whether they are identified in the ...


Surface Kinetic Energy Distributions In The Global Oceans From A High-Resolution Numerical Model And Surface Drifter Observations, Xiaolong Yu, Aurelien Ponte, Shane Elipot, Dimitris Menemenlis, Edward Zaron, Ryan Abernathey Aug 2019

Surface Kinetic Energy Distributions In The Global Oceans From A High-Resolution Numerical Model And Surface Drifter Observations, Xiaolong Yu, Aurelien Ponte, Shane Elipot, Dimitris Menemenlis, Edward Zaron, Ryan Abernathey

Civil and Environmental Engineering Faculty Publications and Presentations

The surface kinetic energy of a 1/48◦ global ocean simulation and its distribution as a function of frequency and location are compared with the one estimated from 15,329 globally distributed surface drifter observations at hourly resolution. These distributions follow similar patterns with a dominant low-frequency component and well-defined tidal and near-inertial peaks globally. Quantitative differences are identified with deficits of low-frequency energy near the equator (factor 2) and at near-inertial frequencies (factor 3) and an excess of energy at semidiurnal frequencies (factor 4) for the model. Owing to its hourly resolution and its near-global spatial coverage, the array ...


Modeling Climate Driven Urban Migration In The United States, Julia Beckwith Aug 2019

Modeling Climate Driven Urban Migration In The United States, Julia Beckwith

REU Final Reports

Though research on climate driven migration has become more prevalent, the majority of recent studies model migration patterns in the Global South. While these inquiries are rightfully focused on populations that will be disproportionately affected by climate change, countries in the Global North are not impervious to these effects. As global population distributions shift, it will be necessary to know which urban areas in the United States might be best equipped to handle influxes of people. Drawing on existing climate-migration frameworks, the agent-based model detailed in this paper utilizes available demographic and climate data to simulate climate-driven migration between key ...


Introducing Cornerstone Courses Into Electrical And Computer Engineering Curriculum, Branimir Pejcinovic Jul 2019

Introducing Cornerstone Courses Into Electrical And Computer Engineering Curriculum, Branimir Pejcinovic

Electrical and Computer Engineering Faculty Publications and Presentations

Almost all engineering programs have some form of final, culminating design experience, which is typically taught as a senior year capstone design course. Due to ABET requirements these are team and project based. Many programs will also have projects interspersed among required and elective courses, but these tend to be overrepresented in freshman year. We have recently introduced a set of courses during sophomore year that mimic our approach to capstone courses and provide authentic engineering design experience. These so-called cornerstone courses provide scaffolding by introducing all of the components of teamwork and design process but in a less formal ...


Analyzing Disparities In Ecosystem Services In U.S. Cities: The Relationship Between Tree Cover And Socio-Demographics, Katherine V. Cendrowski Jun 2019

Analyzing Disparities In Ecosystem Services In U.S. Cities: The Relationship Between Tree Cover And Socio-Demographics, Katherine V. Cendrowski

REU Final Reports

It is a generally accepted fact that trees, and vegetation in general, provide many benefits to human beings. What has not been so extensively studied is how those benefits may be distributed across the United States. This research project aims to study that distribution by modeling and analyzing the land use data of US cities and the socio-demographic data available. We are looking specifically at tree cover as presented in the National Land Cover Dataset (NLCD) in order to determine what the general demographics are of those people that live in closer proximity to trees. We are also looking at ...


A Resource Constrained Shortest Paths Approach To Reducing Personal Pollution Exposure, Elling Payne Jun 2019

A Resource Constrained Shortest Paths Approach To Reducing Personal Pollution Exposure, Elling Payne

REU Final Reports

As wildfires surge in frequency and impact in the Pacific Northwest, in tandem with increasingly traffic-choked roads, personal exposure to harmful airborne pollutants is a rising concern. Particularly at risk are school-age children, especially those living in disadvantaged communities near major motorways and industrial centers. Many of these children must walk to school, and the choice of route can effect exposure. Route-planning applications and frameworks utilizing computational shortest paths methods have been proposed which consider personal exposure with reasonable success, but few have focused on pollution exposure, and all have been limited in scalability or geographic scope. This paper addresses ...


Board 63: Work In Progress: Adapting Scrum Project Management To Ece Courses, Branimir Pejcinovic, Phillip Wong, Robert B. Bass Jun 2019

Board 63: Work In Progress: Adapting Scrum Project Management To Ece Courses, Branimir Pejcinovic, Phillip Wong, Robert B. Bass

Electrical and Computer Engineering Faculty Publications and Presentations

Scrum is a popular form of Agile project management. Its applications now include diverse areas such as software development, engineering, urban planning, and law. Scrum has also been used in software engineering educational programs, but its use in other engineering education is lagging. Within our electrical and computer engineering program, we introduced Scrum to help students improve their teamwork efficacy in projects and courses. Earlier, we have presented some initial experiences and observations when implementing Scrum in ECE courses. In this paper we will elaborate on how Scrum is applied across different years and how we scaffold student learning. Scrum ...


Creating A 3d Printed Bipedal Robot’S Ankle And Foot With Human-Like Motion, Tylise E. Fitzgerald Jun 2019

Creating A 3d Printed Bipedal Robot’S Ankle And Foot With Human-Like Motion, Tylise E. Fitzgerald

Undergraduate Research & Mentoring Program

Humanoid robots are being created to replace humans in dangerous situations, assist overworked humans, and improve our quality of life by completing chores. However, current bipedal robots haven’t matched the performance of humans and are still impractical for commercial use.

One of the Agile and Adaptive Robotics Lab’s goals is to create a humanoid robot whose anatomy is similar to the human body. If this can be accomplished, we can have a functioning model of the human body that we can adjust to improve both humanoid robots’ functions and the functionality of our own human bodies. This specific ...


Omni-Gravity Hydroponics System For Spacecraft, Tara M. Prevo Jun 2019

Omni-Gravity Hydroponics System For Spacecraft, Tara M. Prevo

Undergraduate Research & Mentoring Program

Effective omni-gravity hydroponics will allow astronauts to supplement nutrition and further close the life cycle of water in orbit, lunar, and Martian conditions. This project determines the operational limits of the test cells for the Plant Water Management Hydroponics mission. A scaled 1-g channel was designed by Rihana Mungin to mimic full-scale performance in microgravity that could be tested terrestrially. This project sought to find the limits of operation of the 1-g test cells and identify failure modes that could pose a safety risk in space. The cells were filled at increments of 20% and cycled from 0.184 to ...


Material Parameter Estimation Of Thin Wafers With Terahertz Time-Domain Spectroscopy, Kirk R. Jungles Jun 2019

Material Parameter Estimation Of Thin Wafers With Terahertz Time-Domain Spectroscopy, Kirk R. Jungles

Undergraduate Research & Mentoring Program

Terahertz Time Domain Spectroscopy(THz TDS) is a spectroscopic technique that can be implemented to perform non destructive material parameter extraction on a variety of materials. Accuracy of these material parameters is often limited by statistical variation between measurements and insufficient knowledge of the thickness of the slabs being measured.

The goal of this project was to develop an in house procedure that would allow us to perform THz TDS on thin wafers using an up to date signal processing algorithm that would provide accurate predictions for the thickness of the wafers, reliable estimations of the wafer’s material parameters ...


Evaluation Of Bus-Bicycle And Bus/Right-Turn Traffic Delays And Conflicts, Katherine L. Keeling, Travis B. Glick, Miles Crumley, Miguel A. Figliozzi Jun 2019

Evaluation Of Bus-Bicycle And Bus/Right-Turn Traffic Delays And Conflicts, Katherine L. Keeling, Travis B. Glick, Miles Crumley, Miguel A. Figliozzi

Electrical and Computer Engineering Faculty Publications and Presentations

This research evaluates conflicts and delays caused by interactions among buses, bicycles, and right-turning vehicles at a mixed traffic corridor in Portland, OR. The study site has a near-side bus stop and a right curbside lane designated for buses and right-turning vehicles. Next to the bus/right-turn lane is a bicycle lane with a bicycle box ahead of the bus stop (i.e., between the intersection and the bus stop). This research examines two concerns caused by these overlapping bus, bicycle, and automobile facilities; the first is the number of bus-bicycle conflicts (as a proxy for safety) and the second ...


Electromagnetic Analysis Of A Wind Turbine Magnetic Gearbox, Kang Li, Sina Modaresahmadi, Wesley B. Williams, Jonathan Bird Jun 2019

Electromagnetic Analysis Of A Wind Turbine Magnetic Gearbox, Kang Li, Sina Modaresahmadi, Wesley B. Williams, Jonathan Bird

Electrical and Computer Engineering Faculty Publications and Presentations

The design of the second stage of a 59:1 multi-stage magnetic gearbox for a wind turbine demonstrator is presented. The multi-stage series-connected magnetic gearbox is composed of a 6.45 first stage and 9.14 second stage. A flux-focusing spoke-type rotor typology is used with a unique segmented fully laminated design. The impact of structural design changes is considered with respect to torque density. A new rotor typology is presented that enables the magnetic gearbox to be mechanically assembled first without magnets.


Simulation Of Human Balance Control Using An Inverted Pendulum Model, Joshua E. Caneer Jun 2019

Simulation Of Human Balance Control Using An Inverted Pendulum Model, Joshua E. Caneer

Undergraduate Research & Mentoring Program

The nervous system that human beings use to control balance is remarkably adaptable to a wide variety of environments and conditions. This neural system is likely a combination of many inputs and feedback control loops working together. The ability to emulate this system of balance could be of great value in understanding and developing solutions to proprioceptive disorders and other diseases that affect the human balance control system. Additionally, the process of emulating the human balance system may also have widespread applications to the locomotion capabilities of many types of robots, in both bipedal and non-bipedal configurations.

The goal of ...


Using Thermal Gradient Measurements To Compare Bath Temperature And Agitation Effects On The Quenching Performance Of Palm Oil, Canola Oil And A Conventional Petroleum Oil, Bozidar Matijevic, Bruno F. Canale, Božidar Lišcic, George Totten May 2019

Using Thermal Gradient Measurements To Compare Bath Temperature And Agitation Effects On The Quenching Performance Of Palm Oil, Canola Oil And A Conventional Petroleum Oil, Bozidar Matijevic, Bruno F. Canale, Božidar Lišcic, George Totten

Mechanical and Materials Engineering Faculty Publications and Presentations

A proprietary Liscic/Petrofer cylindrical Inconel 600 probe of 50-mm diameter and 200-mm length which was instrumented with three thermocouples on the same radius of the crosssection at the middle of the length was used to determine the differences in quenching performance of two vegetable oils, palm oil and canola oil, and they were compared to a locally produced conventional petroleum oil quenchant. The cooling curves and heat transfer performance of these oils were determined at different bath temperatures and agitation rates. The work was performed at the Quenching Research Centre located at the Faculty for Mechanical Engineering, University of ...


Global Observations Of Fine-Scale Ocean Surface Topography With The Surface Water And Ocean Topography (Swot) Mission, Rosemary Morrow, Lee-Lueng Fu, Fabrice Ardhuin, Mounir Benkiran, Bertrand Chapron, Emmanuel Cosme, Francesco D’Ovidio, J. Thomas Farrar, Sarah T. Gille, Guillaume Lapeyre, Pierre-Yves Le Traon, Ananda Pascual, Aurélien Ponte, Bo Qiu, Nicolas Rascle, Clement Ubelmann, Jinbo Wang, Edward Zaron May 2019

Global Observations Of Fine-Scale Ocean Surface Topography With The Surface Water And Ocean Topography (Swot) Mission, Rosemary Morrow, Lee-Lueng Fu, Fabrice Ardhuin, Mounir Benkiran, Bertrand Chapron, Emmanuel Cosme, Francesco D’Ovidio, J. Thomas Farrar, Sarah T. Gille, Guillaume Lapeyre, Pierre-Yves Le Traon, Ananda Pascual, Aurélien Ponte, Bo Qiu, Nicolas Rascle, Clement Ubelmann, Jinbo Wang, Edward Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

The future international Surface Water and Ocean Topography (SWOT) Mission, planned for launch in 2021, will make high-resolution 2D observations of sea-surface height using SAR radar interferometric techniques. SWOT will map the global and coastal oceans up to 77.6 latitude every 21 days over a swath of 120 km (20 km nadir gap). Today’s 2D mapped altimeter data can resolve ocean scales of 150 km wavelength whereas the SWOT measurement will extend our 2D observations down to 15–30 km, depending on sea state. SWOT will offer new opportunities to observe the oceanic dynamic processes at scales that ...


X-Ray Determination Of Compressive Residual Stresses In Spring Steel Generated By High-Speed Water Quenching, Diego E. Lozano, George E. Totten, Yaneth Bedolla-Gil, Martha Guerrero-Mata, Marcel Carpio, Gabriela M. Martinez-Cazares Apr 2019

X-Ray Determination Of Compressive Residual Stresses In Spring Steel Generated By High-Speed Water Quenching, Diego E. Lozano, George E. Totten, Yaneth Bedolla-Gil, Martha Guerrero-Mata, Marcel Carpio, Gabriela M. Martinez-Cazares

Mechanical and Materials Engineering Faculty Publications and Presentations

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a ...


Exoskeleton, Vinu Casper, Liliana Fitzpatrick Apr 2019

Exoskeleton, Vinu Casper, Liliana Fitzpatrick

Engineering and Technology Management Student Projects

This is a research about the marketing plan for exoskeleton wearable devices. The objective is to provide a meaningful Customer Value Proposition to the prospective customers.The Samsung company SWOT analysis is the basis for a marketing strategy. The exoskeleton features and market definition is included in the analysis. A competitor analysis of homogeneus exoskeletons providers is included to review the current market. An exhaustive customer analysis was performed to identify the customer needs as the input for the marketing plan development. The potential market was identified to learn about the exoskeleton market share opportunity. The exoskeleton global market is ...


The Applications Of Grid Cells In Computer Vision, Keaton Kraiger Apr 2019

The Applications Of Grid Cells In Computer Vision, Keaton Kraiger

Undergraduate Research & Mentoring Program

In this study we present a novel method for position and scale invariant object representation based on a biologically-inspired framework. Grid cells are neurons in the entorhinal cortex whose multiple firing locations form a periodic triangular array, tiling the surface of an animal’s environment. We propose a model for simple object representation that maintains position and scale invariance, in which grid maps capture the fundamental structure and features of an object. The model provides a mechanism for identifying feature locations in a Cartesian plane and vectors between object features encoded by grid cells. It is shown that key object ...


Integrating Landsat Tm/Etm+ And Numerical Modeling To Estimatewater Temperature In The Tigris River Under Future Climate And Management Scenarios, Muhanned Al-Murib, Scott Wells, Stefan Talke Apr 2019

Integrating Landsat Tm/Etm+ And Numerical Modeling To Estimatewater Temperature In The Tigris River Under Future Climate And Management Scenarios, Muhanned Al-Murib, Scott Wells, Stefan Talke

Civil and Environmental Engineering Faculty Publications and Presentations

Modeling the water quality of rivers and assessing the effects of changing conditions is often hindered by a lack of in situ measurements for calibration. Here, we use a combination of satellite measurements, statistical models, and numerical modeling with CE-QUAL-W2 to overcome in situ data limitations and evaluate the effect of changing hydrologic and climate conditions on water temperature (Tw) in the Tigris River, one of the largest rivers in the Middle East. Because few in situ estimates of Tw were available, remotely-sensed estimates of Tw were obtained from Landsat satellite images at roughly 2 week intervals for the ...


Analysis And Application Of Log-Linear And Quantile Regression Models To Predict Bus Dwell Times, Travis B. Glick, Miguel Figliozzi Apr 2019

Analysis And Application Of Log-Linear And Quantile Regression Models To Predict Bus Dwell Times, Travis B. Glick, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Understanding the key factors that contribute to transit travel times and travel time variability is an essential part of transit planning and research. Delay that occurs when buses service bus stops, dwell time, is one of the main sources of travel time variability and has therefore been the subject of ongoing research to identify and quantify its determinants. Previous research has focused on testing new variables using linear regressions that may be added to models to improve predictions. An important assumption of linear regression models used in past research efforts is homoscedasticity or the equal distribution of the residuals across ...