Engineering Commons^™

Air Quality At Bus Stops: Empirical Analysis Of Exposure To Particulate Matter At Bus Stop Shelters, Miguel Figliozzi, Adam Moore, Christopher Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

Congested traffic corridors in dense urban areas are key contributors to the degradation of urban air quality. While waiting at bus stops, transit patrons may be exposed to greater amounts of vehicle-based pollution, including particulate matter (PM), because of their proximity to the roadway. Current guidelines for the location and the design of bus stops do not take into account air quality or exposure considerations. This study compared the exposure of transit riders waiting at three-sided bus stop shelters that either faced the roadway traffic or faced away from the roadway traffic. Shelters were instrumented with air quality monitoring equipment, …

Overview Of The 2010 Carbonaceous Aerosols And Radiative Effects Study (Cares), Rahul A. Zaveri, William J. Shaw, Daniel J. Cziczo, Beat Schmid, Richard Ferrare, M. Lizabeth Alexander, Raul Alvarez, W. Patrick Arnott, Dean B. Atkinson, Sunil Baidar, Robert M. Banta, James Barnard, Josef Beranek, Larry K. Berg, Fred Brechtel, W. Alan Brewer, John F. Cahill, Brian Cairns, Christopher D. Cappa, D. Chand, S. China, Jennifer M. Comstock, Manvendra K. Dubey, Robert C. Easter, M. H. Erickson, Jerome Fast, Cody Floerchinger, B. Flowers, Edward C. Fortner, Jeffrey S. Gaffney, Mary K. Gilles, Kyle Gorkowski, William Gustafson, Madhu Gyawali, J. Hair, R. M. Hardesty, Joseph Harworth, Scott C. Herndon, Naruki Hiranuma, Chris Hostetler, John M. Hubbe, John T. Jayne, H. Jeong, B. Tom Jobson, Evgueni Kassianov, Lawrence I. Kleinman, C. Kluzek, W. Berk Knighton, Katheryn R. Kolesar, Chongai Kuang, Alena Kubátová, Andrew O. Langford, Alexander Laskin, N. Laulainen, Richard D. Marchbanks, Claudio Mazzoleni, Fan Mei, Ryan C. Moffet, Dan Nelson, Michael Obland, Hilke Oetjen, Timothy B. Onasch, I. Ortega, Matteo Ottaviani, Mikhail Pekour, Kimberly A. Prather, James Gregory Radney, Raymond R. Rogers, Scott P. Sandberg, Arthur J. Sedlacek, Christoph J. Senff, Gunnar I. Senum, Ari Setyan, John E. Shilling, Manishkumar Shrivastava, C. Song, Stephen R. Springston, R. Subramanian, Kaitlyn Suski, Jason Tomlinson, Rainer M. Volkamer, H. W. Wallace, Jian Wang, A. M. Weickmann, Douglas R. Worsnop, Xiao-Ying Yu, Alla Zelenyuk, Qi Zhang

Chemistry Faculty Publications and Presentations

Substantial uncertainties still exist in the scientific understanding of the possible interactions between urban and natural (biogenic) emissions in the production and transformation of atmospheric aerosol and the resulting impact on climate change. The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program’s Carbonaceous Aerosol and Radiative Effects Study (CARES) carried out in June 2010 in Central Valley, California, was a comprehensive effort designed to improve this understanding. The primary objective of the field study was to investigate the evolution of secondary organic and black carbon aerosols and their climate-related properties in the Sacramento urban plume as it was …

Passive Acoustic Vessel Localization, Pasang Sherpa Suwal

Dissertations and Theses

This thesis investigates the development of a low-cost passive acoustic system for localizing moving vessels to monitor areas where human activities such as fishing, snorkeling and poaching are restricted. The system uses several off-the-shelf sensors with unsynchronized clocks where the Time Difference of Arrival (TDOA) or time delay is extracted by cross-correlation of the signal between paired sensors. The cross-correlation function uses phase correlation or Phase Transform (PHAT) which whitens the cross-spectrum in order to de-emphasize dominant frequency components. Using the locations of pairs of sensors as foci, hyperbolic equations can be defined using the time delay between them. With …

An Empirical Study Of Particulate Matter Exposure For Transit Users At Bus Stop Shelters, Adam Moore

Dissertations and Theses

Congested traffic corridors in dense urban areas are key contributors to the degradation of urban air quality. While waiting at bus stops, transit patrons may be exposed to greater amounts of vehicle-based pollution, including particulate matter, due to their proximity to the roadway. Current guidelines for the location and design of bus stops do not take into account air quality or exposure considerations. This thesis provides a unique contribution to roadside air quality studies and presents an innovative method for the consideration of bus shelter placement. Exposure to roadside pollutants is estimated for transit riders waiting at three-sided bus stop …

Memristor-Based Reservoir Computing, Manjari S. Kulkarni

Dissertations and Theses

In today's nanoscale era, scaling down to even smaller feature sizes poses a significant challenge in the device fabrication, the circuit, and the system design and integration. On the other hand, nanoscale technology has also led to novel materials and devices with unique properties. The memristor is one such emergent nanoscale device that exhibits non-linear current-voltage characteristics and has an inherent memory property, i.e., its current state depends on the past. Both the non-linear and the memory property of memristors have the potential to enable solving spatial and temporal pattern recognition tasks in radically different ways from traditional binary transistor-based …

Distributed Solar Photovoltaic Grid Integration System : A Case Study For Performance, Ming Shen

Dissertations and Theses

The needs to the sustainable development of electricity, energy efficiency improvement, and environment pollution reduction have favored the development of distributed generation (DG). But the problems come with increasing DG penetration in distribution networks. This thesis presents the Solar Energy Grid Integration System (SEGIS) Stage III project done by Portland General Electric (PGE), Advanced Energy, Sandia National Lab on a PGE selected distribution feeder. The feeder has six monitored commercial solar PV systems connected. The total power output from the PV systems has the potential to reach 30% of the feeder load. The author analyzes the performance of the solar …

Experimental Study Of Fault Cones And Fault Aliasing, Vedanth Bilagi

Dissertations and Theses

The test of digital integrated circuits compares the test pattern results for the device under test (DUT) to the expected test pattern results of a standard reference. The standard response is typically obtained from simulations. The test pattern and response are created and evaluated assuming ideal test conditions. The standard response is normally stored within automated test equipment (ATE). However the use of ATE is the major contributor to the test cost. This thesis explores an alternative strategy to the standard response. As an alternative to the stored standard response, the response is estimated by fault tolerant technique. The purpose …

Digital Fabric, Sudheer Goshi

Dissertations and Theses

Continuing advances with VLSI have enabled engineers to build high performance computer systems to solve complex problems. The real-world problems and tasks like pattern recognition, speech recognition, etc. still remain elusive to the most advanced computer systems today. Many advances in the science of computer design and technology are coming together to enable the creation of the next-generation computing machines to solve real-world problems, which the human brain does with ease. One such engineering advance is the field of neuromorphic engineering, which tries to establish closer links to biology and help us investigate the problem of designing better computing machines. …

A Fault-Tolerant Alternative To Lockstep Triple Modular Redundancy, Andrew Lockett Baldwin

Dissertations and Theses

Semiconductor manufacturing defects adversely affect yield and reliability. Manufacturers expend vast resources to reduce defects within their processes. As the minimum feature size get smaller, defects become increasingly difficult to prevent. Defects can change the behavior of a logic circuit resulting in a fault. Manufacturers and designers may improve yield, reliability, and profitability by using design techniques that make products robust even in the presence of faults. Triple modular redundancy (TMR) is a fault tolerant technique commonly used to mask faults using voting outcomes from three processing elements (PE). TMR is effective at masking errors as long as no more …

Material Characterization Of Zinc Oxide In Bulk And Nanowire Form At Terahertz Frequencies, Forest Emerson Kernan

Dissertations and Theses

Many new applications are being proposed and developed for use in the terahertz (THz) frequency region. Similarly, many new materials are being characterized for possible use in this area. Nanostructured forms are of particular interest since they may yield desirable properties, but they remain especially challenging to characterize. This work focuses on the characterization of zinc oxide (ZnO) in bulk and nanowire form. A method for characterizing nanostructures at THz by use of a parallel-plate waveguide (PPWG) is presented. This method is novel in that it is simple, both in theory and practice, and does not require the use of …

Evolved Design Of A Nonlinear Proportional Integral Derivative (Npid) Controller, Shubham Chopra

Dissertations and Theses

This research presents a solution to the problem of tuning a PID controller for a nonlinear system. Many systems in industrial applications use a PID controller to control a plant or the process. Conventional PID controllers work in linear systems but are less effective when the plant or the process is nonlinear because PID controllers cannot adapt the gain parameters as needed. In this research we design a Nonlinear PID (NPID) controller using a fuzzy logic system based on the Mamdani type Fuzzy Inference System to control three different DC motor systems. This fuzzy system is responsible for adapting the …

Silk Cryogels For Microfluidics, Christopher David Hinojosa

Dissertations and Theses

Silk fibroin from silkworm cocoons is found in numerous applications ranging from textiles to medical implants. Its recent adoption as a biomaterial is due to the material's strength, biocompatibility, self-assembling behavior, programmable degradability, optical clarity, and its ability to be functionalized with antibodies and proteins. In the field of bioengineering it has been utilized as a tissue scaffolding, drug delivery system, biosensor, and implantable electrode. This work suggests a new application for porous silk in a microscale chromatography column. We demonstrate in situ cryotropic polymerization of highly porous structures in microscale geometries by freezing aqueous silk with a solvent. The …

Scale Invariant Object Recognition Using Cortical Computational Models And A Robotic Platform, Danny Voils

Dissertations and Theses

This paper proposes an end-to-end, scale invariant, visual object recognition system, composed of computational components that mimic the cortex in the brain. The system uses a two stage process. The first stage is a filter that extracts scale invariant features from the visual field. The second stage uses inference based spacio-temporal analysis of these features to identify objects in the visual field. The proposed model combines Numenta's Hierarchical Temporal Memory (HTM), with HMAX developed by MIT's Brain and Cognitive Science Department. While these two biologically inspired paradigms are based on what is known about the visual cortex, HTM and HMAX …

Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah

Dissertations and Theses

We report on the fundamental properties and device applications of semiconductor nanoparticles. ZnO nanowires and CdSe quantum dots were used, prepared, characterized, and assembled into novel light-emitting diodes and solar cells. ZnO nanowire films were grown electrochemically using aqueous soluble chloride-based electrolytes as precursors at temperatures below 90° C. Dopants were added to the electrolyte in the form of chloride compounds, which are AlCl₃, CoCl₂, CuCl₂, and MnCl₂. The optical, magnetic, and structural properties of undoped and transition-metal-ion doped ZnO nanowires were explored. Our results indicate that the as-grown nanowire structures have …

Measurement And Modeling Of Passive Surface Mount Devices On Fr4 Substrates, Rahulkumar Sadanand Koche

Dissertations and Theses

Passive components like resistors, capacitors and inductors are used in every electronic system. These are the very basic components which affect the system performance at higher frequencies and it is necessary to understand and model the behavior of these components in a very accurate manner. This work focuses on utilizing Printed Circuit Board (PCB) test boards, or fixtures, made of FR4 for characterizing Surface Mount Device (SMD) components. Agilent's Advanced Design System (ADS) microwave circuit simulation software was used for designing the microstrip transmission lines as well as for generating the layout for manufacturing of the PCB. SMD resistors, capacitors …

A Class Of Discontinuous Petrov–Galerkin Methods. Part Iii: Adaptivity, Leszek Demkowicz, Jay Gopalakrishnan, Antti H. Niemi

Mathematics and Statistics Faculty Publications and Presentations

We continue our theoretical and numerical study on the Discontinuous Petrov–Galerkin method with optimal test functions in context of 1D and 2D convection-dominated diffusion problems and hp-adaptivity. With a proper choice of the norm for the test space, we prove robustness (uniform stability with respect to the diffusion parameter) and mesh-independence of the energy norm of the FE error for the 1D problem. With hp-adaptivity and a proper scaling of the norms for the test functions, we establish new limits for solving convection-dominated diffusion problems numerically: for 1D and for 2D problems. The adaptive process is fully automatic and starts …

Bottom Topography Mapping Via Nonlinear Data Assimilation, Edward D. Zaron, Marie-Aude Pradal, Patrick D. Miller, Alan F. Blumberg, Nickitas Georgas, Wei Li, Julia Muccino Cornuelle

Civil and Environmental Engineering Faculty Publications and Presentations

A variational data assimilation method is described for bottom topography mapping in rivers and estuaries using remotely sensed observations of water surface currents. The velocity field and bottom topography are related by the vertically integrated momentum and continuity equations, leading to a nonlinear inverse problem for bottom topography, which is solved using a Picard iteration strategy combined with a nonlinear line search. An illustration of the method is shown for Haverstraw Bay, in the Hudson River, where the known bottom topography is well reconstructed. Once the topography has been estimated, currents and water levels may be forecast. The method makes …

Calibration Of Highway Safety Manual: Predictive Models For Oregon State Highways, Fei Xie, Kristie Gladhill, Karen Dixon, Christopher Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

The recently released "Highway Safety Manual" (HSM) published by AASHTO provides a comprehensive set of tools for evaluating and identifying opportunities to improve safety for highway facilities. Included in the HSM is a quantitative method for predicting crashes on the basis of recently developed scientific approaches. These predictive methods currently exist for three facility types: rural two-lane roads; rural multilane highways; and urban and suburban arterial highways. To enhance precision, each HSM predictive method should be calibrated for location conditions. This paper demonstrates the HSM calibration procedure for total crashes in Oregon. The research identified three critical data collection limitations …

Application Of Genetic Algorithm For Synthesis Of Large Reversible Circuits Using Covered Set Partitions, Maher Mofeid Hawash, Baker Abdalhaq, Amjad Hawash, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

We present the results of application of Evolutionary Algorithms to the problem of synthesizing quantum circuits which belong to the class of reversible circuits, represented as an input/output mapping vectors. The paper specifically focuses on large quantum circuits where many valid solutions exist in an exponentially inflating search space. Valid solutions represent the set of all input vector permutations (arrangements) which satisfy the circuit specification. The search space for circuits with large number of variables grows exponentially making it impossible to discover the set of optimal solutions. The paper compares three methods for selecting valid solutions of input vector sequences: …

Decomposition Of Reversible Logic Function Based On Cube-Reordering, Martin Lukac, Michitaka Kameyama, Marek Perkowski, Pawel Kerntopf

Electrical and Computer Engineering Faculty Publications and Presentations

We present a novel approach to the synthesis of incompletely specified reversible logic functions. The method is based on cube grouping; the first step of the synthesis method analyzes the logic function and generates groupings of same cubes in such a manner that multiple sub-functions are realized by a single Toffoli gate. This process also reorders the function in such a manner that not only groups of similarly defined cubes are joined together but also don’t care cubes. The proposed method is verified on standard benchmarks for both reversible and irreversible logic functions. The obtained results show that for functions …

Using Practical Supergain For Passive Imaging With Noise, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

Recent work has shown that endfire beamforming of ocean noise can be used to produce images of the seabed layering [Siderius et al., J. Acoust. Soc. Am. 120, 1315–1323 (2006)]. This initial noise imaging technique used conventional beamforming and was later extended to adaptive beamforming that is theoretically optimal. However, there can be problems with adaptive methods, which include extreme sensitivity to random errors, the required averaging time, and computational complexity. Here, the concept of supergain is used to show that delay and sum beamforming can produce nearly the same results as the optimal adaptive methods without the drawbacks.

The Relationship Between Vmt And Economic Activity, B. Starr Mcmullen, Nathan Eckstein

TREC Final Reports

Vehicle miles traveled (VMT) in the U.S. have exhibited an upward trend over time similar to that observed for gross domestic product (GDP) and personal income (PI). While conventional wisdom suggests that economic growth leads to more driving and thus higher VMT, it is theoretically possible that the causation could also be the other way around. If causation is from VMT to GDP, then legislation such as the Federal Surface Transportation Policy and Planning Act of 2009’s directive to annually reduce national per capita VMT could potentially have an adverse impact on overall economic activity.

This study uses times series …

Future Flooding Impacts On Transportation Infrastructure And Traffic Patterns Resulting From Climate Change, Heejun Chang, Martin Lafrenz, Il-Won Jung, Miguel A. Figliozzi, Rolando Melgoza, David Ruelas, Deena Platman, Cindy Pederson

Geography Faculty Publications and Presentations

This study investigated potential impacts of climate change on travel disruption resulting from road closures in two urban watersheds in the Portland metropolitan area. We used ensemble climate change scenarios, a hydrologic model, stream channel survey, a hydraulic model, and a travel forecast model to develop an integrated impact assessment method. High-resolution climate change scenarios are based on the combinations of two emission scenarios and eight general circulation models. The Precipitation-Runoff Modeling System was calibrated and validated for the period 1988-2006, and simulated for determining the probability of floods from 2020-2049. We surveyed stream cross sections at five road crossings …

Refining Greenstep: Impacts Of Vehicle Technologies And Its/Operational Improvements On Travel Speed And Fuel Consumption Curves, Kelly Clifton, Alexander Y. Bigazzi

Civil and Environmental Engineering Faculty Publications and Presentations

This report describes analysis undertaken to establish a method for incorporating traffic operations and ITS strategies into the GreenSTEP model. We first discuss operations impacts on fuel economy and delay from the literature. Then, an investigation of delay adjustments in GreenSTEP shows that different methods of representing delay changes lead to similar (and small) impacts on fuel economy. From this result we establish average speed adjustment by congestion level as the preferred method for incorporating delay effects from operations improvements. An investigation of aggregate traffic operations impacts produces estimates of base speeds without operations improvements, maximum speeds with full operational …

Bridge Damage Models For Seismic Risk Assessment Of Oregon Highway Network, Peter Dusicka, Jeffery Roberts

TREC Final Reports

The highway transportation network of the United States relies on the health and integrity of major infrastructure elements such as bridges. Frequently traveled parts of Oregon are within the seismically active Pacific Northwest and many of the bridges were designed and built to lateral demands that were assumed to be less than the current expectation, a deficiency caused by our growing awareness of seismic hazard and our enhanced understanding of the non-linear response of bridges. This vulnerability to damage from earthquakes can result in not only immediate damage, but also in potentially lingering economic impact caused by the disruption to …

Maintaining Safe, Efficient And Sustainable Intermodal Transport Through The Port Of Portland, David A. Jay, Jiayi Pan

Civil and Environmental Engineering Faculty Publications and Presentations

About $15 billion of freight passes annually through the Lower Columbia River (LCR) navigation channel to reach Portland and Vancouver, where most of it connects with land transport. This commerce plays a vital role in sustaining the regional economy and connecting Oregon to the global economy. The timely connection of truck and rail transport with vessels is vital, especially for export traffic. This link is susceptible to disruption if water depths in the navigation channel are shallower than expected, leading to delays and/or draft limitations. Moreover, ship drafts have increased in recent decades, 25% of the vessels calling in the …

Large–Scale Laboratory Observations Of Wave Forces On A Highway Bridge Superstructure, Chris Bradner, Thomas Schumacher, Daniel Cox, Christopher Higgins

TREC Final Reports

A. Objectives The objectives of this study are to: (1) conduct the first, large-scale physical model study of wave loads on a highway bridge superstructure under realistic wave conditions and bridge geometries, and (2) evaluate the application of existing design formulas developed for deep water, wave-in-deck loading of offshore structures to shallow water, highway bridge geometries. This will aid in our understanding of the dynamic loads by hurricane waves on highway bridge superstructures and assess the accuracy of present methods for safer design of new bridges or retrofit of existing bridges. B. Scope In their 2006 report titled "Wave Forces …

Non-Stationary Internal Tides Observed With Satellite Altimetry, Richard D. Ray, Edward D. Zaron

Civil and Environmental Engineering Faculty Publications and Presentations

Temporal variability of the internal tide is inferred from a 17-year combined record of Topex/Poseidon and Jason satellite altimeters. A global sampling of along-track sea-surface height wavenumber spectra finds that non-stationary variance is generally 25% or less of the average variance at wavenumbers characteristic of mode-1 tidal internal waves. With some exceptions the non-stationary variance does not exceed 0.25 cm2. The mode-2 signal, where detectable, contains a larger fraction of non-stationary variance, typically 50% or more. Temporal subsetting of the data reveals interannual variability barely significant compared with tidal estimation error from 3-year records. Comparison of summer vs. winter conditions …

Thirdhand Tobacco Smoke: Emerging Evidence And Arguments For A Multidisciplinary Research Agenda, Georg E. Matt, Penelope J. Quintana, Hugo Destaillats, Lara A. Gundel, Mohamad Sleiman, Brett C. Singer, Peyton Jacob, Jonathan P. Winickoff, Prue Talbot, Suzaynn Schick, Yinsheng Wang, Bo Hang, Manuela Martins-Green, James F. Pankow, Melbourne F. Hovell, Neal L. Benowitz, Virender K. Rehan, Jonathan M. Samet

Civil and Environmental Engineering Faculty Publications and Presentations

There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS). We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS. Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include …

Evaluation Of Safe Routes To School Programs: Qualitative And Quantitative Analysis Of Parental Decision-Making, Lynn Weigand, Noreen Mcdonald

TREC Final Reports

In the United States, walking to school declined from 42% of 5-18 year olds in 1969 to 16% in 20011. The US Department of Transportation has responded to this dramatic decrease by funding the Safe Routes to School program for $612 million in SAFETEA-LU. The program’s funding emphasize infrastructure improvements such as completing sidewalks and adding crosswalks by requiring between 70% and 90% of funding be allocated toward infrastructure. However, recent research shows that 2 of 3 children who currently are driven to school, but live close enough to walk, do so because it is more convenient for parents. Currently, …