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Portland State University

2019

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Articles 31 - 60 of 130

Full-Text Articles in Engineering

Drafting In Self-Timed Circuits, Christopher Lee Cowan Aug 2019

Drafting In Self-Timed Circuits, Christopher Lee Cowan

Dissertations and Theses

Intervals between data items propagating in self-timed circuits are controlled by handshake signals rather than by a clock. In many self-timed designs, a trailing data item will catch up with a leading item or token, even when it trails by thousands of gate delays. This effect, called "drafting," can be seen in many of the self-timed designs, e.g., GasP, Mousetrap, Click, and Micropipeline. The purpose of this dissertation is to reveal the circuit mechanism of drafting in self-timed circuits typically used in FIFO stages. Drafting is usually considered to be incidental to the operation of self-timed circuits since interval timing …


Approximate Pattern Matching Using Hierarchical Graph Construction And Sparse Distributed Representation, Aakanksha Mathuria, Dan Hammerstrom Jul 2019

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

Electrical and Computer Engineering Faculty Publications and Presentations

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” 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, even after training on huge numbers of images. Biology appears to take advantage of such a structure, but how? In our research, we are studying approaches for robust pattern matching using still, 2D Blocks World images based on graphical representations of the …


Design Of A Canine Inspired Quadruped Robot As A Platform For Synthetic Neural Network Control, Cody Warren Scharzenberger Jul 2019

Design Of A Canine Inspired Quadruped Robot As A Platform For Synthetic Neural Network Control, Cody Warren Scharzenberger

Dissertations and Theses

Legged locomotion is a feat ubiquitous throughout the animal kingdom, but modern robots still fall far short of similar achievements. This paper presents the design of a canine-inspired quadruped robot named DoggyDeux as a platform for synthetic neural network (SNN) research that may be one avenue for robots to attain animal-like agility and adaptability. DoggyDeux features a fully 3D printed frame, 24 braided pneumatic actuators (BPAs) that drive four 3-DOF limbs in antagonistic extensor-flexor pairs, and an electrical system that allows it to respond to commands from a SNN comprised of central pattern generators (CPGs). Compared to the previous version …


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 …


Large-Scale Der Aggregations Of Electric Water Heaters And Battery Inverter Systems, Kevin Marnell Jul 2019

Large-Scale Der Aggregations Of Electric Water Heaters And Battery Inverter Systems, Kevin Marnell

Dissertations and Theses

Distributed energy resources like residential electric water heaters and residential battery inverter systems offer a small amount of change to the grid individually. When aggregated however, these assets can cause major effects to the electric grid. Aggregating these resources allows them to take on generator-like functions with the ability to increment power and decrement power.

The Western Energy Imbalance Market is an energy market offering 15 minute and 5 minute markets for energy transactions between balancing areas. Generation assets make increment and decrement bids. Traditionally the only entrants to this market have been large scale generators and large scale assets …


Travel Behaviors Of Persons With Intellectual And Developmental Disabilities, Joseph C. Totten Jul 2019

Travel Behaviors Of Persons With Intellectual And Developmental Disabilities, Joseph C. Totten

Civil and Environmental Engineering Master's Project Reports

People with intellectual and developmental disabilities live different lives than the general population. Often prohibited from driving, persons with intellectual disabilities cite transportation as top concern, limiting their independence and freedom to live, work or recreate where and when they choose. Improving services for persons with developmental disabilities requires that engineers and planners understand how persons with intellectual disabilities travel, and what types of transportation are available to them. This report hopes to identify the availability of transportation options to persons with developmental disabilities such that planners, engineers and advocates can determine how altering the transportation system might affect persons’ …


Test Setup Design And Cyclic Evaluation Of Rocking Clt Wall And Floor Restoring Force Lateral System, Aaron Davis Smith Jul 2019

Test Setup Design And Cyclic Evaluation Of Rocking Clt Wall And Floor Restoring Force Lateral System, Aaron Davis Smith

Civil and Environmental Engineering Master's Project Reports

The introduction of the demand for mass timber buildings in areas with seismic hazards has called for new lateral systems. Lateral systems in mass timber building typically utilize a rocking shear wall with post-tensioned rods to provide system re-centering. These post-tensioned rods add axial load to the shear wall and potentially endure long term creep affects. Mass Timber buildings consist of cross laminated (clt) shear walls and floor slabs along with glulam beams. The flexural capacity of the CLT floor slabs along with dead load can provide an alternative source for the restoring force. This project developed a test setup …


The Gouda, The Bad, And The Ugly: Prioritizing Intersections For Pedestrian Safety In Tillamook, Or With Different Risk Estimation Methods, Kelly M. White Jul 2019

The Gouda, The Bad, And The Ugly: Prioritizing Intersections For Pedestrian Safety In Tillamook, Or With Different Risk Estimation Methods, Kelly M. White

Civil and Environmental Engineering Master's Project Reports

The following report explores five different pedestrian risk estimation methods at urban intersections. Six study intersections in Tillamook, Oregon were chosen as a case study to analyze each risk estimation method and apply the values to a project prioritization process. Ultimately, risk factors of both exposure and infrastructure contribute to the highest amount of risk for pedestrians. The Oregon Department of Transportation's State Planning and Research Report 779 was identified as the most comprehensive risk estimation method.


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 …


Characterizing Tilt Effects On Wind Plants, Ryan Scott Jun 2019

Characterizing Tilt Effects On Wind Plants, Ryan Scott

Dissertations and Theses

Tilting the nacelle of a wind turbine modifies entrainment into the wind plant and impacts total efficiency. Extreme angles can produce flying and crashing wakes where the wake either disrupts entertainment from the undisturbed flow above or is decimated on the ground. The effect of tilt angle on downstream wake behavior was investigated in a series of wind tunnel experiments. Scale model turbines with a hub height and diameter of 12 cm were arranged in a Cartesian array comprised of four rows of three turbines each. Nacelle tilt was varied in the third row from -15° to 15° in chosen …


Infinite Photovoltaic Solar Arrays: Considering Flux Of Momentum And Heat Transfer, Andrew D. S. Glick Jun 2019

Infinite Photovoltaic Solar Arrays: Considering Flux Of Momentum And Heat Transfer, Andrew D. S. Glick

Dissertations and Theses

Large scale solar farms supply an increasing amount of the worlds electricity supply. However, in order to reach cost parity with fossil fuels, further reductions are necessary. Towards this end, photovoltaic (PV) panel cooling becomes increasingly important; high temperatures both decrease efficiency and panel lifetime. To better understand, characterize, and exploit the natural convective cooling of utility scale solar farms, a model solar farm was created. Using both thermal measurements and particle image velocimetry to characterize heat transfer and velocity fields, wind tunnel experiments were conducted using the model solar farm. Three parameters were examined for their effect on heat …


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 project looks …


Aggregation Of Electric Water Heaters For Peak Shifting And Frequency Response Services, Thomas Leighton Clarke Jun 2019

Aggregation Of Electric Water Heaters For Peak Shifting And Frequency Response Services, Thomas Leighton Clarke

Dissertations and Theses

The increased penetration of renewable energy sources poses new challenges for grid stability. The stochastic and uncontrollable generation of solar and wind power cannot be adjusted to match the load profile, and the transition away from traditional synchronous generators is reducing the grid capacity to arrest and recover from frequency disturbances.

Additionally, the distributed nature of many renewable energy sources makes centralized control of generation more complicated. The traditional power system paradigm balances the supply and demand of electricity on the grid by regulating generation. As this becomes more difficult, one alternative is to adjust the load instead. This is …


Physics-Based Signal Processing Methods For Terahertz Non-Destructive Evaluation Of Layered Media, Scott G. Schecklman Jun 2019

Physics-Based Signal Processing Methods For Terahertz Non-Destructive Evaluation Of Layered Media, Scott G. Schecklman

Dissertations and Theses

In recent years Terahertz (THz) time domain spectroscopy has emerged as a promising new technology with potential applications in a variety of fields, including industrial manufacturing, security screening and medical imaging. Pulsed THz systems are uniquely suited for non-destructive evaluation (NDE) of the sub-surface layers of dielectric packaging and coating materials, because they provide high dynamic range over a wide bandwidth in the far infrared portion of the electromagnetic spectrum. Often the dielectric materials of the packaging and/or surface coating layers exhibit relatively low loss and abrupt changes in the refractive index at the layer boundaries can be observed as …


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, and demonstration …


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 8.33 …


Uhf And Microwave Phase-Modulated Scattering Array, Nasr Nomas Hussein Alkhafaji Jun 2019

Uhf And Microwave Phase-Modulated Scattering Array, Nasr Nomas Hussein Alkhafaji

Dissertations and Theses

This dissertation investigates the use an array of active nonlinear elements, with particular emphasis on controlling distortion products generated by nonlinear elements in space rather than using conventional ways such as transmission lines, waveguides, and power dividers and combiners. The nonlinear elements are made of assemblies of antennas and electronic switches, called modulated scatterers (MSs). These so-called MSs elements are utilized in a wide variety of applications such as radio frequency identification (RFID) systems, microwave imaging, Internet-of-Things sensors, etc. However, no research work has been reported in the literature regarding exploiting and controlling several distortion products generated by MSs at …


Strength Tuned Steel Eccentric Braced Frames, Hosam Abdullah Al-Azzawi Jun 2019

Strength Tuned Steel Eccentric Braced Frames, Hosam Abdullah Al-Azzawi

Dissertations and Theses

The primary component in eccentrically braced frames (EBF) is the link as its plastic strength controls the design of the frame as well as the entire building within which it is installed. EBFs are the first part of building design and every other component is sized based on the forces developed in the link. Oversized link elements lead to the use of unnecessary materials and can increase construction costs. Additionally, the advantages of using a continuous member of the same depth for both the link and the controller beam (in terms of the cost and the time) motivates researchers to …


Analytical And Numerical Modeling Of Long Term Changes To Tides, Storm Surge, And Total Water Level Due To Bathymetric Changes And Surge Characteristics, Ramin Familkhalili Jun 2019

Analytical And Numerical Modeling Of Long Term Changes To Tides, Storm Surge, And Total Water Level Due To Bathymetric Changes And Surge Characteristics, Ramin Familkhalili

Dissertations and Theses

Natural and local anthropogenic changes in estuaries (e.g., sea-level rise, navigation channel construction and loss of wetlands) interact with each other and produce non-linear effects. There is also a growing recognition that tides in estuaries are not stationary. These factors together are changing the estuarine water level regime, however the implications for extreme water levels remain largely unknown. Changes over the past century in many estuaries, such as channel deepening and streamlining for navigation have significantly altered the hydrodynamics of long waves, often resulting in amplified tides (a ~85% increase in Wilmington, NC since 1900) and storm surge in estuaries. …


Seismic Performance Of Substandard Reinforced Concrete Bridge Columns Under Subduction-Zone Ground Motions, Alvaro Francisco Lopez Ibaceta Jun 2019

Seismic Performance Of Substandard Reinforced Concrete Bridge Columns Under Subduction-Zone Ground Motions, Alvaro Francisco Lopez Ibaceta

Dissertations and Theses

A large magnitude, long duration subduction earthquake is impending in the Pacific Northwest, which lies near the Cascadia Subduction Zone (CSZ). Great subduction zone earthquakes are the largest earthquakes in the world and are the sole source zones that can produce earthquakes greater than M8.5. Additionally, the increased duration of a CSZ earthquake may result in more structural damage than expected. Given such seismic hazard, the assessment of reinforced concrete substructures has become crucial in order to prioritize the bridges that may need to be retrofitted and to maintain the highway network operable after a major seismic event. Recent long …


Memcapacitive Reservoir Computing Architectures, Dat Tien Tran Jun 2019

Memcapacitive Reservoir Computing Architectures, Dat Tien Tran

Dissertations and Theses

In this thesis, I propose novel brain-inspired and energy-efficient computing systems. Designing such systems has been the forefront goal of neuromorphic scientists over the last few decades. The results from my research show that it is possible to design such systems with emerging nanoscale memcapacitive devices.

Technological development has advanced greatly over the years with the conventional von Neumann architecture. The current architectures and materials, however, will inevitably reach their physical limitations. While conventional computing systems have achieved great performances in general tasks, they are often not power-efficient in performing tasks with large input data, such as natural image recognition …


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 …


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.


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 is bus …


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 Zagreb, …


Very High Frequency Bipolar Junction Transistor Frequency Multiplier Drive Network Design And Analysis, Daniel Dale Schaeffer May 2019

Very High Frequency Bipolar Junction Transistor Frequency Multiplier Drive Network Design And Analysis, Daniel Dale Schaeffer

Dissertations and Theses

The function of a frequency multiplier is verbatim -- a frequency multiplier is a circuit that takes a signal of particular frequency at the input and produces harmonic multiples of the input signal's frequency at the output. Their use is widespread throughout history, primarily in the application of frequency synthesis. When implemented as a part of a large system, a chain of multipliers can be used to synthesize multiple reference signals from a single high-performance reference oscillator.

Frequency multiplier designs use a variety of nonlinear devices and topologies to achieve excitation of harmonics. This thesis will focus on the design …


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 are important in …


How Av Could Shape Our Cities - Research From The Netherlands, Gonçalo H. A. Correia May 2019

How Av Could Shape Our Cities - Research From The Netherlands, Gonçalo H. A. Correia

PSU Transportation Seminars

Automated driving has become a hot topic of research in different fields of science. Despite the great advancements in the vehicle technology itself, researchers are now concerned in figuring out what will be the impacts of these vehicles in life as we know it. These impacts can be rather broad from traffic safety to the economy. In this lecture, Goncalo will focus on the research that is being done at TU Delft, a leading university in automated vehicles’ (AVs) impacts research, focusing on urban areas and how mobility, and even the city itself, can change with fully-automated vehicles. Goncalo Correia …