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Full-Text Articles in Engineering

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 Dec 2011

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 …


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 Nov 2011

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 …


The Relationship Between Vmt And Economic Activity, B. Starr Mcmullen, Nathan Eckstein Nov 2011

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 …


Refining Greenstep: Impacts Of Vehicle Technologies And Its/Operational Improvements On Travel Speed And Fuel Consumption Curves, Kelly Clifton, Alexander Y. Bigazzi Nov 2011

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 …


Large–Scale Laboratory Observations Of Wave Forces On A Highway Bridge Superstructure, Chris Bradner, Thomas Schumacher, Daniel Cox, Christopher Higgins Oct 2011

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 …


Bridge Damage Models For Seismic Risk Assessment Of Oregon Highway Network, Peter Dusicka, Jeffery Roberts Oct 2011

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 Oct 2011

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 …


Non-Stationary Internal Tides Observed With Satellite Altimetry, Richard D. Ray, Edward D. Zaron Sep 2011

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 Sep 2011

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 Aug 2011

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, …


Factors For Improved Fish Passage Waterway Construction, David N. Sillars, Hamid Moradkhani, Nicholas Tymvios, Trevor D. Smith Jun 2011

Factors For Improved Fish Passage Waterway Construction, David N. Sillars, Hamid Moradkhani, Nicholas Tymvios, Trevor D. Smith

TREC Final Reports

Streambeds are important fish passageways in Oregon; they provide for the necessary habitats and spawning cycles of a healthy fish population. Oregon state law requires that hydraulic structures located in water properly provide fish passage. Increasingly stringent state and federal regulations apply to these fish passageways, and designers must become more cognizant of conditions over a range of flows to accommodate fish movement and avoid expensive structural failure of these passageways. Fish passage structures are built when roads cross streambeds and may include culverts, or bridges. When these structures are built, the streambeds are re-created using a technique called “roughened …


Assessment Of Statewide Intersection Safety Performance, Christopher M. Monsere, Todd Johnson, Karen Dixon, Jianfei Zheng, Ida Schalkwyk Jun 2011

Assessment Of Statewide Intersection Safety Performance, Christopher M. Monsere, Todd Johnson, Karen Dixon, Jianfei Zheng, Ida Schalkwyk

TREC Final Reports

This report summarizes the results of an analysis of the safety performance of Oregon’s intersections. Following a pilot study, a database of 500 intersections randomly sampled from around the state of Oregon in both urban and rural environments was assembled. These intersections were categorized into eight types based on number of legs (3 and 4), land use (urban or rural) and traffic control (signalized or minor stop-control). These categories were chosen to align with the intersection types in AASHTO’s recently released Highway Safety Manual (HSM). Geometric and traffic control elements were supplemented by compiling crash data and volumes on the …


Statistical Comparisons Of Watershed-Scale Response To Climate Change In Selected Basins Across The United States, John Risley, Hamid Moradkhani, Lauren Hay, Steve Markstrom May 2011

Statistical Comparisons Of Watershed-Scale Response To Climate Change In Selected Basins Across The United States, John Risley, Hamid Moradkhani, Lauren Hay, Steve Markstrom

Civil and Environmental Engineering Faculty Publications and Presentations

In an earlier global climate-change study, air temperature and precipitation data for the entire twenty-first century simulated from five general circulation models were used as input to precalibrated watershed models for 14 selected basins across the United States. Simulated daily streamflow and energy output from the watershed models were used to compute a range of statistics. With a side-by-side comparison of the statistical analyses for the 14 basins, regional climatic and hydrologic trends over the twenty-first century could be qualitatively identified. Low-flow statistics (95% exceedance, 7-day mean annual minimum, and summer mean monthly streamflow) decreased for almost all basins. Annual …


Case Study Evaluation Of Dynamic Traffic Assignment Tools, John Gliebe, Åsa Bergman Mar 2011

Case Study Evaluation Of Dynamic Traffic Assignment Tools, John Gliebe, Åsa Bergman

Urban Studies and Planning Faculty Publications and Presentations

A case study was undertaken in order to evaluate the potential use of dynamic traffic assignment (DTA) tools by Oregon Department of Transportation (ODOT) and its partner agencies. The objectives of this study were to provide insight into the nature of DTA models, to inform the program selection process, and to develop realistic expectations for potential DTA work plans. The overarching goal of this report is to describe the process followed and experiences of the study team in developing and testing DTA network models. Two available DTA programs were selected for in-depth analysis from a preliminary screening of available programs: …


Exploratory Methods For Truck Re-Identification In A Statewide Network Based On Axle Weight And Axle Spacing Data To Enhance Freight Metrics, Christopher M. Monsere, Mecit Cetin, Andrew Nichols Feb 2011

Exploratory Methods For Truck Re-Identification In A Statewide Network Based On Axle Weight And Axle Spacing Data To Enhance Freight Metrics, Christopher M. Monsere, Mecit Cetin, Andrew Nichols

TREC Final Reports

The main objective of this project is to evaluate the feasibility of re-identifying commercial trucks based on vehicle-attribute data automatically collected by sensors installed at traffic data collection stations. To support this work, archived data from weigh-in-motion (WIM) stations in Oregon are used for developing, calibrating, and testing vehicle re-identification algorithms. The vehicle re-identification methods developed in this research consist of two main stages. In the first stage, each vehicle from the downstream station is matched to the most “similar” upstream vehicle by using a Bayesian model. In the second stage, several methods are introduced to screen out those vehicles …


Development Of An Open Source Bridge Management System, Michael H. Scott Feb 2011

Development Of An Open Source Bridge Management System, Michael H. Scott

TREC Final Reports

A bridge management system is developed using the Tcl scripting language in conjunction with the OpenSees finite element software framework. Fully programmable and string-based, Tcl is ideal for implementing live load analysis through scripts and experimenting with emergent bridge rating methodologies. Since Tcl is an interpreted language, the application also has the important advantage that new bridge capacity models and rating factor calculations can be implemented on multiple platforms without compiling source code. The network programming features of Tcl give the system access to databases for conducting internet-based bridge rating. The system is demonstrated for rating a conventionally reinforced concrete …


Assessment And Refinement Of Real-Time Travel Time Algorithms For Use In Practice, Phase Ii, Kristin A. Tufte, Soyoung Ahn, Sirisha Murthy Kothuri Feb 2011

Assessment And Refinement Of Real-Time Travel Time Algorithms For Use In Practice, Phase Ii, Kristin A. Tufte, Soyoung Ahn, Sirisha Murthy Kothuri

TREC Final Reports

The Federal Highway Administration (FHWA) has put a high priority on the use of existing dynamic message signs (DMS) to provide travel time estimates to the public. The Oregon Department of Transportation (ODOT) has three DMS in the Portland metropolitan area configured to display travel time information. In the near future, ODOT would like to make travel time estimates available on additional DMS, over the Internet on tripcheck.com and via 511. Travel time estimates are valuable to the traveling public; however, the estimates must be accurate to be useful. The purpose of this study is to extend prior travel time …


A Matrix Formulation For The Moment Distribution Method Applied To Continuous Beams, Arlindo Pires Lopes, Adriana Santos, Rogério Coelho Lopes Jan 2011

A Matrix Formulation For The Moment Distribution Method Applied To Continuous Beams, Arlindo Pires Lopes, Adriana Santos, Rogério Coelho Lopes

Civil and Environmental Engineering Faculty Publications and Presentations

The Moment Distribution Method is a quite powerful hand method of structural analysis, in which the solution is obtained iteratively without even formulating the equations for the unknowns. It was formulated by Professor Cross in an era where computer facilities were not available to solve frame problems that normally require the solution of simultaneous algebraic equations. Its relevance today, in the era of personal computers, is in its insight on how a structure reacts to applied loads by rotating its nodes and thus distributing the loads in the form of member-end moments. Such an insight is the foundation of the …


Highway Safety Investigation Manual For The Oregon Department Of Transportation, Karen Dixon, Christopher Monsere Jan 2011

Highway Safety Investigation Manual For The Oregon Department Of Transportation, Karen Dixon, Christopher Monsere

Civil and Environmental Engineering Faculty Publications and Presentations

Across the state, region, and nation highway safety investigators have developed a wide variety of tools and techniques for highway safety investigation procedures. Analysis techniques can range from systematic evaluation approaches such as the Oregon Department of Transportation’s (ODOT’s) Safety Priority Index System (SPIS) down to specific localized safety assessment strategies. It is important to develop consistent methods for safety evaluations across Oregon to ensure that safety investigations are conducted in a similar manner. It is also important to develop a screening process for proper highway safety investigations and document the procedures used for this assessment.

The objective of this …


Circulation, Sediment Concentration And Oxygen Depletion In The Tidal Ems River, Stefan A. Talke, Huib E. De Swart Jan 2011

Circulation, Sediment Concentration And Oxygen Depletion In The Tidal Ems River, Stefan A. Talke, Huib E. De Swart

Civil and Environmental Engineering Faculty Publications and Presentations

We present measurements which show that the tidal Ems River in Germ any is extremely muddy over a 30 km + turbid zone, with fluid mud o f 1-2 m thickness covering the bed with suspended sediment concentrations (SSC) o f greater than 50 kg.m-3. Moreover, we show that these elevated SSC contain large quantities of organic material which deplete dissolved oxygen (DO) and produce summertime hypoxic zones. Using mathematical modeling, we develop simplified representations o f the estuary physics that reproduce the tidally-averaged circulation, SSC distribution, and oxygen depletion. These models show that SSC and oxygen concentrations …


Infrared-Based Measurements Of Velocity, Turbulent Kinetic Energy, And Dissipation At The Water Surface In A Tidal River, C. Chris Chickadel, Stefan A. Talke, Alexander R. Horner-Devine, Andrew T. Jessup Jan 2011

Infrared-Based Measurements Of Velocity, Turbulent Kinetic Energy, And Dissipation At The Water Surface In A Tidal River, C. Chris Chickadel, Stefan A. Talke, Alexander R. Horner-Devine, Andrew T. Jessup

Civil and Environmental Engineering Faculty Publications and Presentations

Thermal infrared (IR) based particle image velocimetry (PIV) is used to measure the evolution of velocity, turbulent kinetic energy (TKE), and the TKE dissipation rate at the water surface in the tidally influenced Snohomish River. Patterns of temperature variability in the IR imagery arise from disruption of the cool skin layer and are used to estimate the 2D velocity field. Comparisons of IR based PIV mean velocity made against a collocated acoustic velocimeter demonstrate high correlation (r2 > 0.9). Over a tidal period, surface TKE computed from the IR velocity varies from 10-4 J·kg-1 to 3x10-3 J·kg-1, with an average difference …


Improving The Characterization Of Initial Condition For Ensemble Streamflow Prediction Using Data Assimilation, Caleb Matthew Dechant, Hamid Moradkhani Jan 2011

Improving The Characterization Of Initial Condition For Ensemble Streamflow Prediction Using Data Assimilation, Caleb Matthew Dechant, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

Within the National Weather Service River Forecast System, water supply forecasting is performed through Ensemble Streamflow Prediction (ESP). ESP relies both on the estimation of initial conditions and historically resampled forcing data to produce seasonal volumetric forecasts. In the western US, the accuracy of initial condition estimation is particularly important due to the large quantities of water stored in mountain snowpack. In order to improve the estimation of snow quantities, this study explores the use of ensemble data assimilation. Rather than relying entirely on the model to create single deterministic initial snow water storage, as currently implemented in operational forecasting, …


Freight Distribution Problems In Congested Urban Areas: Fast And Effective Solution Procedures To Time-Dependent Vehicle Routing Problems, Miguel A. Figliozzi Jan 2011

Freight Distribution Problems In Congested Urban Areas: Fast And Effective Solution Procedures To Time-Dependent Vehicle Routing Problems, Miguel A. Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

Congestion is a common phenomenon in all medium to large cities of the world. Reliability of freight movement in urban areas is an important issue to manufacturing or service companies whose operation is based in just-in-time approaches. These companies tend to provide high value or time sensitive products/services. As congestion increases, carriers face increasing challenges to satisfy their time sensitive customers in an economical way. Route designs or schedules which require long computation times or ignore travel time variations will result in inefficient and suboptimal solutions. Poorly designed routes that lead freight vehicles into congested arteries and streets not only …


Low Flow Forecasting With A Lead Time Of 14 Days For Navigation And Energy Supply In The Rhine River, Mehmet C. Demirel, Martijn Booij Jan 2011

Low Flow Forecasting With A Lead Time Of 14 Days For Navigation And Energy Supply In The Rhine River, Mehmet C. Demirel, Martijn Booij

Civil and Environmental Engineering Faculty Publications and Presentations

Low flow forecasting, days or even months in advance, is particularly important to the efficient operation of power plants and freight shipment. This study presents a low flow forecasting model with a lead time of 14 days for the Rhine River. The forecasts inherit uncertainty sources mainly because of model parameterization. Therefore, a systematic uncertainty analysis is applied to indicate the major uncertainty sources in the results. Firstly, the Rhine basin is divided into 7 major sub-basins. Each sub-basin is modeled separately with a data-driven model and the output discharges are routed to Lobith after German-Dutch border with another data-driven …


Uncertainty Analysis Of A Low Flow Model For The Rhine River, Mehmet C. Demirel, Martijn Booij Jan 2011

Uncertainty Analysis Of A Low Flow Model For The Rhine River, Mehmet C. Demirel, Martijn Booij

Civil and Environmental Engineering Faculty Publications and Presentations

It is widely recognized that hydrological models are subject to parameter uncertainty. However, little attention has been paid so far to the uncertainty in parameters of the data-driven models like weights in neural networks. This study aims at applying a structured uncertainty analysis to a data-driven model for low flow forecasting with a lead time of 14 days in the Rhine River. In the modeling phase, the Rhine basin is divided into seven major sub-basins. Each sub-basin is modeled separately with a data-driven model and the output discharges were routed to Lobith with another data-driven model. Basin averaged precipitation, basin …