Engineering Commons^™

Feedforward Chemical Neural Network: An In Silico Chemical System That Learns Xor, Drew Blount, Peter Banda, Christof Teuscher, Darko Stefanovic

Electrical and Computer Engineering Faculty Publications and Presentations

Inspired by natural biochemicals that perform complex information processing within living cells, we design and simulate a chemically implemented feedforward neural network, which learns by a novel chemical-reaction-based analogue of backpropagation. Our network is implemented in a simulated chemical system, where individual neurons are separated from each other by semipermeable cell-like membranes. Our compartmentalized, modular design allows a variety of network topologies to be constructed from the same building blocks. This brings us towards general-purpose, adaptive learning in chemico: wet machine learning in an embodied dynamical system.

Analysis And Testing Of A Coaxial Magnetic Gearbox With Flux Concentration Halbach Rotors, Debarupa Som, Kang Li, Joshua Kadel, Jason Wright, Sina Modaresahmadi, Jonathan Bird, W. William

Electrical and Computer Engineering Faculty Publications and Presentations

Halbach array magnetic gearboxes have been discussed as being able to create high torque density. However, Halbach arrays are difficult to mechanically assembly and often the effective air-gap must be made larger in order to provide space for a retaining sleeve. This paper investigates the benefits of using an additional ferromagnetic retaining pole within the Halbach array structure. It is shown that utilizing this flux concentration ferromagnetic pole improves the torque density and can also help retain the magnets in place.

Reactive Stepping With Functional Neuromuscular Stimulation In Response To Forward-Directed Perturbations, Alexander J. Hunt, Brooke M. Odle, Lisa M. Lombardo, Musa L. Audu, Ronald J. Triolo

Mechanical and Materials Engineering Faculty Publications and Presentations

Background: Implanted motor system neuroprostheses can be effective at increasing personal mobility of persons paralyzed by spinal cord injuries. However, currently available neural stimulation systems for standing employ patterns of constant activation and are unreactive to changing postural demands. Methods: In this work, we developed a closed-loop controller for detecting forward-directed body disturbances and initiating a stabilizing step in a person with spinal cord injury. Forward-directed pulls at the waist were detected with three body-mounted triaxial accelerometers. A finite state machine was designed and tested to trigger a postural response and apply stimulation to appropriate muscles so as to produce …

Early Layout Design Exploration In Tsv-Based 3d Integrated Circuits, Mohammad Abrar Ahmed

Dissertations and Theses

Through silicon via (TSV) based 3D integrated circuits have inspired a novel design paradigm which explores the vertical dimension, in order to alleviate the performance and power limitations associated with long interconnects in 2D circuits. TSVs enable vertical interconnects across stacked and thinned dies in 3D-IC designs, resulting in reduced wirelength, footprint, faster speed, improved bandwidth, and lesser routing congestion. However, the usage of TSVs itself gives rise to many critical design challenges towards the minimization of chip delay and power consumption. Therefore, realization of the benefits of 3D ICs necessitates an early and realistic prediction of circuit performance during …

China's Motorization Wave And The Place Of Emerging Technologies, Christopher Cherry

PSU Transportation Seminars

E-bikes, E-Cars, Carshare, Bikeshare, and Micro-EVs in China have shaken up the traditional motorization pathways that have occurred in developing countries in the past. The combination of emerging vehicle technologies, urban and environmental constraints, and heavy-handed policy make China's motorization processes unique in the world—but how China motorizes has far-reaching impacts based on sheer volume of vehicles and population.

This seminar discusses the results of a six-year NSF CAREER project to explore China's motorization processes, combining behavioral and environmental modeling approaches to assess the impacts of emerging vehicle technologies on motorization and ultimately environmental sustainability. The focus is mostly on …

Focusing On Equity In Regional Plans, Kristine M. Williams

TREC Project Briefs

Metropolitan planning organizations (MPOs) have long been required to consider the equity implications of their regional transportation plans and processes.

Improving Quality Of Patient Care Through Automated Nerve Segmentation, Madisen D. Phillips

Maseeh Summer Undergraduate Research Experience

A continuous peripheral nerve block cPNB is most commonly used in patients during the post-operative period, with documented benefits that include a decrease in reported pain, a decrease of opioid related side effects, and an increase in patient satisfaction. Accurately identifying nerve structures for cPNB placement is a critical step for proper insertion. The aim of this research is to use supervised learning techniques (least squares regression and Receiver Operating Characteristic (ROC) curve analysis) to build a model that can segment and annotate a bundle of nerves known as the brachial plexus (BP) while minimizing segmentation error. Dependent on large …

Passive Bottom Reflection-Loss Estimation Using Ship Noise And A Vertical Line Array, Lanfranco Muzi, Martin Siderius, Christopher M. Verlinden

Electrical and Computer Engineering Faculty Publications and Presentations

An existing technique for passive bottom-loss estimation from natural marine surface noise (generated by waves and wind) is adapted to use noise generated by ships. The original approach—based on beamforming of the noise field recorded by a vertical line array of hydrophones—is retained; however, additional processing is needed in order for the field generated by a passing ship to show features that are similar to those of the natural surface-noise field. A necessary requisite is that the ship position, relative to the array, varies over as wide a range of steering angles as possible, ideally passing directly over the array …

Evolution Of An Introductory Electrical Engineering And Programming Course, Branimir Pejcinovic, Phillip Wong

Electrical and Computer Engineering Faculty Publications and Presentations

Our first year electrical engineering sequence includes two courses that involve programming and hardware interfacing. ECE 102 deals with engineering problem solving and MATLAB, while ECE 103 introduces C programming. We use MATLAB both as a problem solving tool and as an introduction to programming. Students utilize MATLAB to control a data acquisition device, which enables more realistic team-based projects that combine problem-solving, programming, and interfacing. As is widely recognized, these types of courses are important and difficult to teach. We identified areas that needed improvement in ECE 102: a) outdated lecture format, b) not enough timely feedback, c) insufficient …

Land Use And Active Travel: A Complex Relationship, Steven R. Gehrke

TREC Project Briefs

While it’s accepted that mixed-use development promotes active travel, researchers don’t have a consensus on exactly how land use determines people’s travel patterns.

Generalized Differential Calculus And Applications To Optimization, R. Blake Rector

Dissertations and Theses

This thesis contains contributions in three areas: the theory of generalized calculus, numerical algorithms for operations research, and applications of optimization to problems in modern electric power systems. A geometric approach is used to advance the theory and tools used for studying generalized notions of derivatives for nonsmooth functions. These advances specifically pertain to methods for calculating subdifferentials and to expanding our understanding of a certain notion of derivative of set-valued maps, called the coderivative, in infinite dimensions. A strong understanding of the subdifferential is essential for numerical optimization algorithms, which are developed and applied to nonsmooth problems in operations …

Utilization Of Remote Sensing In Drought Monitoring Over Iraq, Yousif Almamalachy

Dissertations and Theses

Agricultural drought is a creeping disaster that overshadows the vegetative cover in general and cropland specifically in Iraq, a country that was well known for its agricultural production and fertile soil. In the recent years, the arable lands in Iraq experienced increasing land degradation that led to desertification, economic losses, food insecurity, and deteriorating environment. Remote sensing is employed in this study and four different indices are utilized, each of which is derived from MODIS satellite mission products. Agricultural drought maps are produced from 2003 to 2015 after masking the vegetation cover. Year 2008 was found the most severe drought …

Investigation Into Effects Of Instability And Reactivity Of Hydride-Passivated Silicon Nanoparticles On Interband Photoluminescence, Christine Marie Radlinger

Dissertations and Theses

While silicon has long been utilized for its electronic properties, its use as an optical material has largely been limited due to the poor efficiency of interband transitions. However, discovery of visible photoluminescence (PL) from nanocrystalline silicon in 1990 triggered many ensuing research efforts to optimize PL from nanocrystalline silicon for optical applications. Currently, use of photoluminescent silicon nanoparticles (Si NPs) is commercially limited by: 1) the instability of the energy and intensity of the PL, and 2) the low quantum yield of interband PL from Si NPs.

Herein, red-emitting, hydrogen-passivated silicon nanoparticles (H-Si NPs) were synthesized by thermally-induced disproportionation …

Network Congestion Effect Of E-Hailing Transportation Services, Xuegang Ban

PSU Transportation Seminars

E-hailing plays a key role in emerging transportation services such as ridesourcing, ridesharing and taxis, among others. This seminar will present a general economic model to analyze the congestion effect of e-hailing services in a transportation network.

The model can help analyze customers’ choices of different modes, based on their value of time and the charging schemes of different services, as well as the overall impact of the services to network level congestion.

Find, Build, And Export Information For 3d Printing Of Your Favorite Molecules And Crystal Structures At Two Dedicated Websites, Paul R. Destefano, Peter Moeck

Student Research Symposium

As 3D printers require instructions, the Nano-Crystallography Group at Portland State University is creating two websites (http://nanocrystallography.org/3dconvert/ and http://nanocrystallography.research.pdx.edu/3d-print-files/convert/) where such instructions are created, interactively, for the atomic arrangements of virtually all known molecules and crystals.

We will prepare a "pipeline" into which crystallographic information enters from two curated open access crystallographic databases, is manipulated to create the desired 3D models, and then is exported in either STL format (the standard for monochrome 3D printing) or VRML/X3D (the ISO successor to STL). The two aforementioned databases are the North-American mirror of the Crystallography Open Database (http://nanocrystallography.org) …

Fe Analysis Of Alternative Thermal Breaks For Steel Buildings, Salih Q. Mahmood

Student Research Symposium

“Thermal bridge” is a term used for structural or non-structural elements that have higher heat transfer than any other elements or spots in the building envelope, reducing the efficiency of the building thermal insulation. About 20% of the heat occurs via such thermal bridges. Thermal insulations (thermal breaks) are used within a steel connection to mitigate the effect of thermal bridges. In this research, connections with steel fillers studied by Dusicka (2007) were simulated using the finite element (FE) program ABAQUS. The results from the FE model were validated with those from the experimental work done by Dusicka (2007) and …

Monitoring Of Applied Stress In Concrete Using Ultrasonic Full-Waveform Comparison Techniques, Ali Hafiz

Student Research Symposium

Ultrasonic testing is a non-destructive approach commonly used to evaluate concrete structures. A challenge with concrete is that it is heterogeneous, which causes multiple wave scattering resulting in longer and more complex wave paths. The recorded ultrasonic waveform can be divided into two portions: the coherent (or early) and the diffuse (or Coda) portion. While conventional methods only use the coherent portion, e.g. the first wave arrival to determine the wave velocity, we are interested in the entire waveform, i.e. until the wave amplitude is completely dampened out. The objective of this study was to determine what portion of the …

Extended Saleh Model For Behavioral Modeling Of Envelope Tracking Power Amplifiers, Haider Al Kanan, Fu Li, Felice Francesco Tafuri

Student Research Symposium

Envelope Tracking (ET) is one of the most deployed efficiency enhancement techniques to improve efficiency of RF Power Amplifiers (PAs) in wireless communication. ET PA behavioral models are important to predict the impact of the nonlinear distortion, and memory effect of ET PA on the spectrum in wireless communication. ET PA linearization techniques can be designed based on the behavioral modeling.

Understanding Photovoltaic Properties Of Pbs Quantum Dot Solids Via Solution Contacting, Vitalii Dereviankin, Erik Johansson

Student Research Symposium

Photovoltaic (PV) devices based on PbS quantum dot (QD) solids demonstrate high photontoelectron conversion yields. However, record power conversion efficiency remain low, in part due to small photovoltages, which in turn are affected by both bulk and interfacial defects. Their relative impacts on limiting the photovoltaic performance of QD solids are not known. Interfacial defects can be formed when contacting a semiconductor and may dominate the semiconductor/metal or metaloxide junction properties. The objective of this study is to explore whether electrochemical contacting using liquid electrolytes provides means of contacting QD solids without introducing interfacial defects. We have initially focused on …

Behavior-Based Freight Modeling At Metro, Chris Johnson, Bud Reiff

PSU Transportation Seminars

Chris Johnson and Bud Reiff will present on a behavior-based freight model being used at Oregon Metro. This model will replace Metro’s current truck model with a hybrid freight model that both represents multi-modal freight flows through elements of national and regional supply chains and simulates the movement of individual trucks and shipments on local networks. Model estimation and calibration will also require collection of behavioral data from shippers and receivers representing a wide range of industries, common and contract freight carriers, business that operate non-freight commercial vehicles, warehouse managers, and logistics agents.

Key project objectives:

• Develop tools to enable …

Peer-To-Peer Carsharing: Short-Term Effects On Travel Behavior In Portland, Or, Jennifer Dill, Nathan Mcneil, Steven Howland

TREC Final Reports

Peer-to-peer (P2P) carsharing is a relatively new concept in the U.S. Enabled by recent internet and mobile technology development, P2P carsharing generally involves a facilitating company connecting private vehicle owners to people who are interested in renting a vehicle. P2P carsharing has many things in common with business-to-consumer (B2C) carsharing services. Consumers join the service to rent vehicles on a short-term basis from locations dispersed throughout a certain area. Both services may allow households to reduce their private car ownership. However, P2P carsharing differs substantially from other models in that there are two distinct sets of consumers: those who rent …

Narratives Of Marginalized Cyclists: Understanding Obstacles To Utilitarian Cycling Among Women And Minorities In Portland, Or, Amy Lubitow

TREC Final Reports

Research has demonstrated that everyday or utilitarian forms of cycling are most likely to generate positive population-level health impacts (Garrard et al., 2012), yet significant deterrents to routine cycling remain, particularly for women and minorities. The primary aim of this project was to conduct a qualitative interview study that generated rich, narrative data regarding obstacles to routine or utilitarian cycling for women and minorities who already see biking as a viable form of transit, but who make relatively few bike trips. A secondary aim of the project was to develop a set of specific interventions that have the potential to …

Sparse Coding On Stereo Video For Object Detection, Sheng Y. Lundquist, Melanie Mitchell, Garrett T. Kenyon

Computer Science Faculty Publications and Presentations

Deep Convolutional Neural Networks (DCNN) require millions of labeled training examples for image classification and object detection tasks, which restrict these models to domains where such a dataset is available. We explore the use of unsupervised sparse coding applied to stereo-video data to help alleviate the need for large amounts of labeled data. In this paper, we show that unsupervised sparse coding is able to learn disparity and motion sensitive basis functions when exposed to unlabeled stereo-video data. Additionally, we show that a DCNN that incorporates unsupervised learning exhibits better performance than fully supervised networks. Furthermore, finding a sparse representation …

Inertial And Time-Of-Arrival Ranging Sensor Fusion, Paul Vasilyeav, Sean Pearson, Mahmoud El-Gohary, Mateo Aboy, James Mcnames

Electrical and Computer Engineering Faculty Publications and Presentations

Wearable devices with embedded kinematic sensors including triaxial accelerometers, gyroscopes, and magnetometers are becoming widely used in applications for tracking human movement in domains that include sports, motion gaming, medicine, and wellness. The kinematic sensors can be used to estimate orientation, but can only estimate changes in position over short periods of time. We developed a prototype sensor that includes ultra wideband ranging sensors and kinematic sensors to determine the feasibility of fusing the two sensor technologies to estimate both orientation and position. We used a state space model and applied the unscented Kalman filter to fuse the sensor information. …

Using An Altimeter-Derived Internal Tide Model To Remove Tides From In Situ Data, Edward D. Zaron, Richard D. Ray

Civil and Environmental Engineering Faculty Publications and Presentations

Internal waves at tidal frequencies, i.e., the internal tides, are a prominent source of variability in the ocean associated with significant vertical isopycnal displacements and currents. Because the isopycnal displacements are caused by ageostrophic dynamics, they contribute uncertainty to geostrophic transport inferred from vertical profiles in the ocean. Here it is demonstrated that a newly developed model of the main semidiurnal (M2) internal tide derived from satellite altimetry may be used to partially remove the tide from vertical profile data, as measured by the reduction of steric height variance inferred from the profiles. It is further demonstrated that the internal …

Jet Bounce In Low Gravity, Caleb Turner

Maseeh Summer Undergraduate Research Experience

Liquid jets rebound (‘bounce’) from superhydrophobic surfaces when they impinge at oblique angles. We call this interesting phenomena ‘jet bounce’ and in this work we investigate the phenomena at large length scales in a reduced gravitational environment. For example, for water at Reynolds numbers 0 < Re < 3500 and surface normal Weber numbers 0 < We < 60 we characterize the response of the jets on the hydrophobic surface in the brief 2.1s micro-gravity environment achieved using a drop tower. It is observed that by varying jet velocity, flow rate, jet diameter, and incident angle we observe up to four distinct regimes of behavior. The various regimes may be targeted for specific applications and we demonstrate a variety of unique jet bounce behaviors for applications such as no-touch, no-contact fluid-thermal transport for spacecraft unit operations such as contaminated water processing, device cooling, and cryogenic fluids transport and management.

Stable jet bounce from small diameter jet ≈ 1 mm and low impact angle. Characterizing Reynolds number ≈ 900 and normal Weber number ≤ 10 allow jet bounce to rebound in non-destructive behavior.

Design And Test Of 3d Printed Lenses For Sub-Thz Radiation, Justin Patterson

Maseeh Summer Undergraduate Research Experience

The terahertz gap in the electromagnetic spectrum provides promising advantages for applications such as increased airport security and medical diagnosis. Quasi-optical systems used to study THz radiation require multiple mirrors or lenses, which can be quite costly. In order to manipulate THz beams we investigated production of inexpensive lenses using additive 3D printing. 3D printing technology promises to be not only accessible and inexpensive, but should also enable quick experimentation with different lens designs. The Picometrix time-domain spectroscopy (TDS) system was used to characterize 3D printable plastics. The absorption coefficient and refractive index were analyzed from 0.2 to 2 THz …

Conditional Averaging And Classification In The Near Wake Of A Wind Turbine Array Boundary Layer, Sarah E. Smith

Maseeh Summer Undergraduate Research Experience

Flow perturbation induced by interaction with a turbine rotor produces considerable turbulence which can alter the productivity of subsequent units within a wind farm. Previous methods have characterized near wake vorticity of a single turbine as well as recovery distance for various turbine array configurations. This study aims to build from previous methods of analysis from the perspective of the rotor well within a turbine array and develop a model to examine points of significant imposition in relation to rotational effects. Hot wire anemometry was employed downstream of a turbine located in the middle of the third row in a …

Flux Focusing Axial Magnetic Gear, Robert J. Rutherford

Maseeh Summer Undergraduate Research Experience

Power transmission is traditionally achieved with a mechanical gear. These gears require maintenance, cause vibration, and have no overload protection. Magnetic gears (MGs) offer an innovative solution to these drawbacks as they do not require regular maintenance, have no need for lubrication, create very little acoustic noise, have built in overload protection and as a result of these advantages, have a longer lifetime of operation. The flux focusing axial magnetic gear (FFAMG) was assembled for future testing of power transmission, conversion, and generation applications.

Gears are used to transmit power by converting low speed-high torque rotary motion into high speed-low …

Deposition Velocity Dependence On Urban Morphology, Rawand Muzafar Rasheed

Maseeh Summer Undergraduate Research Experience

Understanding the interactions between the atmospheric boundary layer and urban structures provides insights into emerging problems such as green building design as well as dispersion and deposition of pollutants on urban structures. Characterization of deposition velocity dependence through the naphthalene sublimation method on model urban structures is conducted herein where the analogous fundamental transport mechanisms of momentum and mass transport is obtained via mass of naphthalene transferred. Via wind tunnel experiments, results show that deposition velocity of naphthalene from urban structures increases with increased number of urban structures ahead of the point of investigation. This is attributed to the wakes …