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Articles 1561 - 1590 of 2758

Full-Text Articles in Engineering

Comparing Technological Advancement Of Hybrid Electric Vehicles (Hev) In Different Market Segments, Dong-Joon Lim, Shabnam Razeghian Jahromi, Timothy R. Anderson, Anca-Alexandra Tudori Jan 2015

Comparing Technological Advancement Of Hybrid Electric Vehicles (Hev) In Different Market Segments, Dong-Joon Lim, Shabnam Razeghian Jahromi, Timothy R. Anderson, Anca-Alexandra Tudori

Engineering and Technology Management Faculty Publications and Presentations

The Toyota Prius was first introduced in 1997 and since then over 150 hybrid electric vehicles (HEVs) have been brought to the automobile market around the world. This was spurred by a major interest in the future of vehicles using ‘alternative fuel’ for addressing environmental and fuel dependency concerns. Based upon previous work1, which identified an input-output model that could successfully explain the progress of HEV technologies, this study evaluates and compares the technological advancement observed in different HEV market segments over the past 15 years. The results indicate that the introduction of a wide range of midsize HEVs is …

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Forecasting Oled Tv Technology Using Bibliometrics And Fisher-Pry Diffusion Model, Yonghee Cho, Tugrul Unsal Daim, Paul Sklar Jan 2015

Forecasting Oled Tv Technology Using Bibliometrics And Fisher-Pry Diffusion Model, Yonghee Cho, Tugrul Unsal Daim, Paul Sklar

Engineering and Technology Management Faculty Publications and Presentations

The market of flat panel displays is experiencing rapid growth with the advancement of digital technologies in broadcasting service. The next challenge of LCD is OLED in TV market. The study attempts to investigate the trends in advanced or emerging technologies by determining their technology diffusion rates due to the lack of experiential data. With the development of information and communication technology, one of the recent methods to assist in technology forecasting is data mining in bibliometric or textual data from various sources such as patents, journals, and research awards. The information extracted from diverse sources can be employed in …

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Opening The Door To Breakthroughs That Address Strategic Organizational Needs: Applying Technology Roadmapping Tools And Techniques At An Electric Utility, James V. Hillegas-Elting, Terry Oliver, Joshua Binus, Tugrul Unsal Daim, Judith Estep, Jisun Kim Jan 2015

Opening The Door To Breakthroughs That Address Strategic Organizational Needs: Applying Technology Roadmapping Tools And Techniques At An Electric Utility, James V. Hillegas-Elting, Terry Oliver, Joshua Binus, Tugrul Unsal Daim, Judith Estep, Jisun Kim

Engineering and Technology Management Faculty Publications and Presentations

Over the course of a decade, the Bonneville Power Administration's Technology Innovation Office has developed a roadmapping approach that captures business challenges and opportunities critical to the agency, links these with barriers to success, and connects these with technical solutions and research questions. Senior leaders from across the agency establish strategic goals and objectives, and international technical subject matter experts are convened to articulate technology-associated paths to achieve these. Each roadmap captures insights from diverse experts in highly collaborative environments and focuses them on critically important topics. These roadmaps are an important element in the Bonneville Power Administration's strategic approach …

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Safety At Intersections In Oregon: A Preliminary Update Of Statewide Intersection Crash Rates, Daniel R. Hazel Jan 2015

Safety At Intersections In Oregon: A Preliminary Update Of Statewide Intersection Crash Rates, Daniel R. Hazel

Civil and Environmental Engineering Master's Project Reports

This research aims to provide a preliminary update to statewide intersection crash rates for the state of Oregon using 2008-2013 crash data and a statewide sample of 129 intersections where two (or more) state-owned facilities intersect. Using intersections where state-owned facilities represent both the major and minor legs of the intersection allows for the maintenance of up-to-date intersection crash rates by eliminating time-intensive traffic volume data collection. Due to the frequency and severity of crashes at intersections, development of easily obtained intersection crash rates is important to assess trends and effectiveness of safety countermeasures employed at these locations in the …

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Demonstrating "Data Near Here": Scientific Data Search, Veronika Margaret Megler, David Maier Jan 2015

Demonstrating "Data Near Here": Scientific Data Search, Veronika Margaret Megler, David Maier

Computer Science Faculty Publications and Presentations

Prior work proposed "Data Near Here" (DNH), a data search engine for scientific archives that is modeled on Internet search engines. DNH performs a periodic, asynchronous scan of each dataset in an archive, extracting lightweight features that are combined to form a dataset summary. During a search, DNH assesses the similarity of the search terms to the summary features and returns to the user, at interactive timescales, a ranked list of datasets for further exploration and analysis. We will demonstrate the search capabilities and ancillary metadata-browsing features for an archive of observational oceanographic data. While comparing search terms to complete …

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The Mechanisms Of Information Integration In Experimental Prediction Markets, Richard Jolly, Martin Zwick, Wayne Wakeland, James Woods, Barry Anderson Jan 2015

The Mechanisms Of Information Integration In Experimental Prediction Markets, Richard Jolly, Martin Zwick, Wayne Wakeland, James Woods, Barry Anderson

Complex Systems Faculty Publications and Presentations

The desire to understand the mechanisms of market information integration motivates this study. Experimental prediction markets are used in a large sample study and the results from the markets as well as individuals' actions are analyzed. By varying the presence and type of feedback the mechanisms of information collection and information aggregation were studied. Markets without feedback demonstrated information collection by outperforming the average of their participants. When feedback was introduced the inductive process of information aggregation was observed. This process was seen to simultaneously increase the amount of information assimilated, but also introduce information mirages which tend to decrease …

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Continuous Monitoring Of Movement In Patients With Parkinson's Disease Using Inertial Sensors, Mahmoud Ahmed El-Gohary, Sean Pearson, James Mcnames, Martina Mancini, Fay Horak Jan 2015

Continuous Monitoring Of Movement In Patients With Parkinson's Disease Using Inertial Sensors, Mahmoud Ahmed El-Gohary, Sean Pearson, James Mcnames, Martina Mancini, Fay Horak

Electrical and Computer Engineering Faculty Publications and Presentations

Gait impairment is a hallmark of Parkinson's disease (PD). The assessment of gait and balance in the clinic may not adequately reflect mobility in daily life. It is often reported that patients with PD walk better when they are examined in an outpatient clinic or in a research laboratory than at home. Continuous monitoring of mobility during spontaneous daily activities may provide clinicians and patients with objective measures of the quality of their mobility. We show that continuous monitoring of spontaneous gait with wearable inertial sensors during daily activities is feasible for patients with PD. We tested 13 patients with …

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The Skill Of Seasonal Ensemble Low-Flow Forecasts In The Moselle River For Three Different Hydrological Models, Mehmet C. Demirel, Martijn Booij, Arjen Hoekstra Jan 2015

The Skill Of Seasonal Ensemble Low-Flow Forecasts In The Moselle River For Three Different Hydrological Models, Mehmet C. Demirel, Martijn Booij, Arjen Hoekstra

Civil and Environmental Engineering Faculty Publications and Presentations

This paper investigates the skill of 90-day low-flow forecasts using two conceptual hydrological models and one data-driven model based on Artificial Neural Networks (ANNs) for the Moselle River. The three models, i.e. HBV, GR4J and ANN-Ensemble (ANN-E), all use forecasted meteorological inputs (precipitation P and potential evapotranspiration PET), whereby we employ ensemble seasonal meteorological forecasts. We compared low-flow forecasts for five different cases of seasonal meteorological forcing: (1) ensemble P and PET forecasts; (2) ensemble P forecasts and observed climate mean PET; (3) observed climate mean P and ensemble PET forecasts; (4) observed climate mean P and PET and (5) …

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Modeling The Effects Of Congestion On Fuel Economy For Advanced Power Train Vehicles, Alexander Y. Bigazzi, Kelly J. Clifton Jan 2015

Modeling The Effects Of Congestion On Fuel Economy For Advanced Power Train Vehicles, Alexander Y. Bigazzi, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

This paper describes research undertaken to establish plausible fuel-speed curves (FSC) for hypothetical advanced power train vehicles. These FSC are needed to account for the effects of congestion in long-term transportation scenario analysis considering fuel consumption and emissions. We use the PERE fuel consumption model with real-world driving schedules and a range of vehicle characteristics to estimate fuel economy (FE) in varying traffic conditions for light-duty internal combustion engine (ICE) vehicles, hybrid gas-electric vehicles (HEV), fully electric vehicles (EV), and fuel cell vehicles (FCV). FSC are fit to model results for each of 145 hypothetical vehicles. Analysis of the FSC …

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Using Household Travel Surveys To Adjust Ite Trip Generation Rates, Kristina Marie Currans, Kelly J. Clifton Jan 2015

Using Household Travel Surveys To Adjust Ite Trip Generation Rates, Kristina Marie Currans, Kelly J. Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

The Institute of Transportation Engineers (ITE) Trip Generation Handbook has become the predominant method for estimating vehicle trips generated by development. The handbook is often criticized for its inability to account for multimodal behavior in urban contexts, often overestimating vehicle traffic. The purpose of this research is to develop and test a ready-to-use method for adjusting the ITE handbook vehicle trip generation estimates for urban context. This method was created using household travel surveys from Oregon, Washington, and Maryland, as well as nationally available built environment data. Three adjustments were estimated for eight general land-use categories, including a “pooled” category …

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Adjusting Ite’S Trip Generation Handbook For Urban Context, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs Jan 2015

Adjusting Ite’S Trip Generation Handbook For Urban Context, Kelly J. Clifton, Kristina Marie Currans, Christopher D. Muhs

Civil and Environmental Engineering Faculty Publications and Presentations

This study examines the ways in which urban context affects vehicle trip generation rates across three land uses. An intercept travel survey was administered at 78 establishments (high-turnover restaurants, convenience markets, and drinking places) in the Portland, Oregon, region during 2011. This approach was developed to adjust the Institute of Transportation Engineers (ITE) Trip Generation Handbook vehicle trip rates based on built environment characteristics where the establishments were located. A number of policy-relevant built environment measures were used to estimate a set of nine models predicting an adjustment to ITE trip rates. Each model was estimated as a single measure: …

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Workshop Synthesis: Built Environment And Contextual Variables, Kelly Clifton, Pascal Perez Jan 2015

Workshop Synthesis: Built Environment And Contextual Variables, Kelly Clifton, Pascal Perez

Civil and Environmental Engineering Faculty Publications and Presentations

This two-day workshop focused on the important issue of how to define, convey and understand the built environment context as it relates to transport decisions. The field has grown tremendously over the last few decades, fueled in part by the increasing availability of archived spatial data about the environment and geo-referencing activity and travel patterns. But there are persistent issues particularly with inconsistencies in data format or availability across locations that hamper efforts to advance our understanding across regions. Further, there are new challenges in how we communicate context to survey respondents, particularly in stated preference surveys. Much of the …

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Empirical Evaluation Of Transit Signal Priority Through Fusion Of Heterogeneous Transit And Traffic Signal Data And Novel Performance Measures, Wei Feng, Miguel A. Figliozzi, Robert Bertini Jan 2015

Empirical Evaluation Of Transit Signal Priority Through Fusion Of Heterogeneous Transit And Traffic Signal Data And Novel Performance Measures, Wei Feng, Miguel A. Figliozzi, Robert Bertini

Civil and Environmental Engineering Faculty Publications and Presentations

Transit signal priority (TSP) can reduce transit delay at signalized intersections by making phasing adjustments. TSP is a relatively inexpensive and easy to implement tool to make transit service faster and more reliable. TSP also sends a signal that a city or region encourages the growth of transit mode split. With the aim of assessing the performance of an existing TSP system, this study had access to a unique set of high-resolution bus and traffic signal data. Novel algorithms and performance measures to measure TSP performance are proposed. Results indicate that a timely and effective TSP system requires a high …

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A Level-Of-Service Model For Protected Bike Lanes, Nick Foster, Christopher Monsere, Jennifer Dill, Kelly Clifton Jan 2015

A Level-Of-Service Model For Protected Bike Lanes, Nick Foster, Christopher Monsere, Jennifer Dill, Kelly Clifton

Civil and Environmental Engineering Faculty Publications and Presentations

Several methods exist for quantifying the quality of service provided by a roadway from a bicyclist’s perspective; however, many of these models do not consider physically protected bike lanes and, of those that do, none is based on empirical data from the US. This is problematic as engineers, planners, and elected officials are increasingly looking to objective performance measures to help guide transportation project design and funding prioritization decisions. This paper addresses this gap by presenting a cumulative logistic model to predict user comfort on protected bike lanes developed from data collected during in-person video surveys. The surveys were conducted …

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Roadway Determinants Of Bicyclist Multi-Pollutant Exposure Concentrations, Alexander Y. Bigazzi, Miguel A. Figliozzi Jan 2015

Roadway Determinants Of Bicyclist Multi-Pollutant Exposure Concentrations, Alexander Y. Bigazzi, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Due to poorly quantified traffic-exposure relationships, transportation professionals are unable to easily estimate exposure differences among bicycle routes for network planning, design, and analysis. This paper estimates the effects of roadway characteristics on bicyclist multi-pollutant exposure concentrations, controlling for meteorology and background conditions. Concentrations of volatile organic compounds (VOC), carbon monoxide (CO), and fine particulate matter (PM2.5) are modeled using high-resolution on-road data. This paper also compares exposure differences on immediately parallel high-traffic/low-traffic facilities and is the first study to quantify VOC exposure differences by facility. Results indicate that average daily traffic (ADT) provides a parsimonious way to characterize the …

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Dynamic Ventilation And Power Output Of Urban Bicyclists, Alexander Y. Bigazzi, Miguel A. Figliozzi Jan 2015

Dynamic Ventilation And Power Output Of Urban Bicyclists, Alexander Y. Bigazzi, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Bicyclist intake of air pollutants is linked to physical exertion levels, ventilation rates, and exposure concentrations. Whereas exposure concentrations have been widely studied in transportation environments, there is relatively scant research linking on-road ventilation with travel conditions and exertion levels. This paper investigates relationships among power output, heart rate, and ventilation rate for urban bicyclists. Heart rate and ventilation rate were measured on-road and combined with power output estimates from a bicycle power model. Dynamic ventilation rates increased by 0.4-0.8% per watt of power output, with a mean lag of 0.8 minutes. The use of physiology (ventilation) monitoring straps and …

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Empirical Analysis Of Bus Bunching Characteristics Based On Bus Avl/Apc Data, Wei Feng, Miguel A. Figliozzi Jan 2015

Empirical Analysis Of Bus Bunching Characteristics Based On Bus Avl/Apc Data, Wei Feng, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of service and capacity. Understanding the temporal and spatial characteristics and the causes and effects of bus bunching incidents from archived bus data can greatly aid transit agencies to develop efficient mitigation strategies. This paper presents methods to identify and visualize specific time periods and segments where bus bunching incidents occur based on automatic vehicle location (AVL) and automatic passenger count (APC) data. The paper also proposes methods that …

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Does The Bicycle Detector Symbol Change Cyclist Queuing Position At Signalized Intersections?, Stefan W. Bussey, Christopher M. Monsere, Peter Koonce Jan 2015

Does The Bicycle Detector Symbol Change Cyclist Queuing Position At Signalized Intersections?, Stefan W. Bussey, Christopher M. Monsere, Peter Koonce

Civil and Environmental Engineering Faculty Publications and Presentations

The Manual of Traffic Control Devices (MUTCD) includes a bicycle detector pavement marking (Section 9C-05) and accompanying explanatory sign (R10-22) which may encourage cyclists to position themselves over detection at traffic signals. This paper presents the results of an observational and survey- based study evaluating the bicycle detector marking. Three minor actuated approaches at signalized intersections with significant bicycle volumes and without bicycle detector markings were selected for treatment. Three configurations were compared: 1) bicycle detector marking only 2) bicycle detector marking with the R10-22 explanatory sign, and 3) an alternative bicycle detector installed over a contrasting green rectangle. Analysis …

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Exploring Thresholds For Timing Strategies On A Pedestrian Active Corridor, Sirisha Murthy Kothuri, Peter Koonce, Christopher M. Monsere, Titus Reynolds Jan 2015

Exploring Thresholds For Timing Strategies On A Pedestrian Active Corridor, Sirisha Murthy Kothuri, Peter Koonce, Christopher M. Monsere, Titus Reynolds

Civil and Environmental Engineering Faculty Publications and Presentations

Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective of this paper is to explore signal timing control strategies to reduce pedestrian delay at signalized intersections. The impacts of change in signal controller mode of operation (coordinated vs. free) at intersections were studied using the micro-simulation software VISSIM. A base model was developed and calibrated for an existing pedestrian active corridor. A hypothetical network of three intersections was used to explore the effects of mode of operation and measures of delay for pedestrians …

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Tides And The Swot Mission: Transition From Science Definition Team To Science Team, Brian K. Arbic, Florent Lyard, Aurelien Ponte, Richard D. Ray, James G. Richman, Jay F. Shriver, Edward Zaron, Zhongxiang Zhao Jan 2015

Tides And The Swot Mission: Transition From Science Definition Team To Science Team, Brian K. Arbic, Florent Lyard, Aurelien Ponte, Richard D. Ray, James G. Richman, Jay F. Shriver, Edward Zaron, Zhongxiang Zhao

Civil and Environmental Engineering Faculty Publications and Presentations

As the SWOT wide-swath satellite altimeter mission transitions from the Science Definition Team to the Science Team, it is an opportune time to review the progress that has been made with respect to tides, and the work remaining to be done. As with previous altimeter missions, tides present both an opportunity and a challenge for the SWOT mission. The TOPEX/Jason class of altimeters have allowed high-accuracy mapping of open-ocean barotropic tides over their coverage latitudes (66°S to 66°N), but the inter-track spacing of these missions (~150 km) has limited their ability to map smaller-scale features such as shelf tides, coastal …

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Creating A National Nonmotorized Traffic Count Archive: Process And Progress, Krista Nordback, Kristin A. Tufte, Morgan Harvey, Nathan Mcneil, Elizabeth Stolz, Jolene Liu Jan 2015

Creating A National Nonmotorized Traffic Count Archive: Process And Progress, Krista Nordback, Kristin A. Tufte, Morgan Harvey, Nathan Mcneil, Elizabeth Stolz, Jolene Liu

Civil and Environmental Engineering Faculty Publications and Presentations

Robust bicycle and pedestrian data on a national scale would help promote effective planning and engineering of walking and bicycling facilities, build the evidence-based case for funding such projects, and dispel notions that walking and cycling are not occurring. To organize and promote the collection of nonmotorized traffic data, a team of transportation professionals and computer scientists is creating a national bicycle and pedestrian count archive. This archive will enable data sharing by centralizing continuous and short-duration traffic counts in a publicly available online archive. Although other archives exist, this will be the first archive that will be national in …

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Evolution And Usage Of The Portal Data Archive: 10-Year Retrospective, Kristin A. Tufte, Robert Bertini, Morgan Harvey Jan 2015

Evolution And Usage Of The Portal Data Archive: 10-Year Retrospective, Kristin A. Tufte, Robert Bertini, Morgan Harvey

Civil and Environmental Engineering Faculty Publications and Presentations

The Portal transportation data archive (http://portal.its.pdx.edu/) was begun in June 2004 in collaboration with the Oregon Department of Transportation, with a single data source: freeway loop detector data. In 10 years, Portal has grown to contain approximately 3 TB of transportation-related data from a wide variety of systems and sources, including freeway data, arterial signal data, travel times from Bluetooth detection systems, transit data, and bicycle count data. Over its 10-year existence, Portal has expanded both in the type of data that it receives and in the geographic regions from which it gets data. This paper discusses the …

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The Effects Of Global Change Upon United States Air Quality, Rodrigo Gonzalez-Abraham, Serena H. Chung, Jeremy C. Avise, Brian Lamb, Eric P. Salathé Jr., Christopher G. Nolte, Dan Loughlin, Alex Guenther, Christine Wiedinmyer, Tiffany Duhl, Yang Zhang, David G. Streets Jan 2015

The Effects Of Global Change Upon United States Air Quality, Rodrigo Gonzalez-Abraham, Serena H. Chung, Jeremy C. Avise, Brian Lamb, Eric P. Salathé Jr., Christopher G. Nolte, Dan Loughlin, Alex Guenther, Christine Wiedinmyer, Tiffany Duhl, Yang Zhang, David G. Streets

Civil and Environmental Engineering Faculty Publications and Presentations

To understand more fully the effects of global changes on ambient concentrations of ozone and particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5) in the United States (US), we conducted a comprehensive modeling effort to evaluate explicitly the effects of changes in climate, biogenic emissions, land use and global/regional anthropogenic emissions on ozone and PM2.5 concentrations and composition. Results from the ECHAM5 global climate model driven with the A1B emission scenario from the Intergovernmental Panel on Climate Change (IPCC) were downscaled using the Weather Research and Forecasting (WRF) model to provide regional meteorological fields. We …

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Estimation Of Transient Temperature Distribution During Quenching, Via A Parabolic Model, Diego E. Lozano, Gabriela Martinez-Solis, Rafael David Mercado-Solis, Rafael Colás, George E. Totten Jan 2015

Estimation Of Transient Temperature Distribution During Quenching, Via A Parabolic Model, Diego E. Lozano, Gabriela Martinez-Solis, Rafael David Mercado-Solis, Rafael Colás, George E. Totten

Mechanical and Materials Engineering Faculty Publications and Presentations

A material-independent model to estimate the transient temperature distribution in a test probe quenched by immersion is presented in this study. This model is based on the assumption that, under one-dimensional unsteady heat conduction, the radial temperature distribution at the end of an interval belongs to the equation of a parabola. The model was validated using AISI 304 stainless steel test probes (Φ8×40 mm and Φ12×60 mm) quenched from 850 to 900 °C in water and in water-based NaNO2 solutions at 25 °C and in canola oil at 50 °C. Additionally, square test probes (20×20×100 mm) were quenched from 550 …

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Phase Transitions And In Situ Dynamics Of Crystal Grain Formation Of Alumina Nanotubes Templated By Vertically Aligned Carbon Nanotubes, L. F. Lampert, A. Barnum, S. W. Smith, J. F. Conley, Jun Jiao Jan 2015

Phase Transitions And In Situ Dynamics Of Crystal Grain Formation Of Alumina Nanotubes Templated By Vertically Aligned Carbon Nanotubes, L. F. Lampert, A. Barnum, S. W. Smith, J. F. Conley, Jun Jiao

Mechanical and Materials Engineering Faculty Publications and Presentations

Phase transitions of amorphous alumina (a-alumina) nanotubes grown by atomic layer deposition and templated by carbon nanotubes were investigated with thermal annealing, transmitted Kikuchi electron diffraction, electron-irradiation-induced crystallization, X-ray diffraction, and X-ray photoelectron spectroscopy. The resulting, engineered alumina nanotube arrays demonstrate a large range of tunable phases that are vital for understanding how alumina nanotube arrays can be applied for uses within biotechnology, catalysis, and other academic and industrial uses.

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Anisotropy Of The Reynolds Stress Tensor In The Wakes Of Wind Turbine Arrays In Cartesian Arrangements With Counter-Rotating Rotors, Nicholas Hamilton, Raúl Bayoán Cal Jan 2015

Anisotropy Of The Reynolds Stress Tensor In The Wakes Of Wind Turbine Arrays In Cartesian Arrangements With Counter-Rotating Rotors, Nicholas Hamilton, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

A 4 × 3 wind turbine array in a Cartesian arrangement was constructed in a wind tunnel setting with four configurations based on the rotational sense of the rotor blades. The fourth row of devices is considered to be in the fully developed turbine canopy for a Cartesian arrangement. Measurements of the flow field were made with stereo particle-image velocimetry immediately upstream and downstream of the selected model turbines. Rotational sense of the turbine blades is evident in the mean spanwise velocity W and the Reynolds shear stress −vw. The flux of kinetic energy is shown to be of greater …

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High-Resolution Bottom-Loss Estimation Using The Ambient-Noise Vertical Coherence Function, Lanfranco Muzi, Martin Siderius, Jorge E. Quijano, Stan E. Dosso Jan 2015

High-Resolution Bottom-Loss Estimation Using The Ambient-Noise Vertical Coherence Function, Lanfranco Muzi, Martin Siderius, Jorge E. Quijano, Stan E. Dosso

Electrical and Computer Engineering Faculty Publications and Presentations

The seabed reflection loss (shortly "bottom loss") is an important quantity for predicting transmission loss in the ocean. A recent passive technique for estimating the bottom loss as a function of frequency and grazing angle exploits marine ambient noise (originating at the surface from breaking waves, wind, and rain) as an acoustic source. Conventional beamforming of the noise field at a vertical line array of hydrophones is a fundamental step in this technique, and the beamformer resolution in grazing angle affects the quality of the estimated bottom loss. Implementation of this technique with short arrays can be hindered by their …

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Modular Timing Constraints For Delay-Insensitive Systems, Hoon Park, Anping He, Marly Roncken, Xiaoyu Song, Ivan Sutherland Jan 2015

Modular Timing Constraints For Delay-Insensitive Systems, Hoon Park, Anping He, Marly Roncken, Xiaoyu Song, Ivan Sutherland

Electrical and Computer Engineering Faculty Publications and Presentations

This paper introduces ARCtimer, a framework for modeling, generating, verifying, and enforcing timing constraints for individual self-timed handshake components. The constraints guarantee that the component’s gate-level circuit implementation obeys the component’s handshake protocol specification. Because the handshake protocols are delayinsensitive, self-timed systems built using ARCtimer-verified components are also delay-insensitive. By carefully considering time locally, we can ignore time globally. ARCtimer comes early in the design process as part of building a library of verified components for later system use. The library also stores static timing analysis (STA) code to validate and enforce the component’s constraints in any self-timed system built …

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Coupled-Oscillator Associative Memory Array Operation For Pattern Recognition, Dmitri E. Nikonov, Gyorgy Csaba, Wolfgang Porod, Tadashi Shibata, Danny Voils, Dan Hammerstrom, Ian A. Young, George I. Bourianoff Jan 2015

Coupled-Oscillator Associative Memory Array Operation For Pattern Recognition, Dmitri E. Nikonov, Gyorgy Csaba, Wolfgang Porod, Tadashi Shibata, Danny Voils, Dan Hammerstrom, Ian A. Young, George I. Bourianoff

Electrical and Computer Engineering Faculty Publications and Presentations

Operation of the array of coupled oscillators underlying the associative memory function is demonstrated for various interconnection schemes (cross-connect, star phase keying and star frequency keying) and various physical implementation of oscillators (van der Pol, phase-locked loop, spin torque). The speed of synchronization of oscillators and the evolution of the degree of matching is studied as a function of device parameters. The dependence of errors in association on the number of the memorized patterns and the distance between the test and the memorized pattern is determined for Palm, Furber and Hopfield association algorithms.

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Wavelet-Coupled Machine Learning Methods For Drought Forecast Utilizing Hybrid Meteorological And Remotely-Sensed Data, R. Tan, Marek Perkowski Jan 2015

Wavelet-Coupled Machine Learning Methods For Drought Forecast Utilizing Hybrid Meteorological And Remotely-Sensed Data, R. Tan, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

In this study, a statistical drought early warning method is proposed using novel machine learning algorithms, with the inclusion of multiple drought-related attributes from precipitation, satellite-derived land cover vegetation indices, and surface discharge. The forecast is made for the long-term hydrological drought in the region of Central Valley, California. The wavelet transform analysis is employed in combination with support vector regression and artificial neural network algorithms for improving the drought prediction effectiveness. The performance of the drought prediction is evaluated using three statistical metrics: Coefficient of Determination (R2 ), Root-Mean-Square Error (RMSE), and Mean-Absolute-Error (MAE). The results clearly indicate that …

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