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A Fuzzy Ahp Approach To Compare Transit System Performance In Us Urbanized Areas, Xin Li, Yingling Fan, John W. Shaw, Yunlei Qi 2017 University of Wisconsin - Milwaukee

A Fuzzy Ahp Approach To Compare Transit System Performance In Us Urbanized Areas, Xin Li, Yingling Fan, John W. Shaw, Yunlei Qi

Journal of Public Transportation

Public transit systems in the United States often face multiple policy objectives. Typically, stakeholders desire frequent service on an extensive network, but funding and other resources are constrained, creating complicated relationships between service effectiveness goals and business efficiency goals. Using data from the National Transit Map (NTM), this study evaluated the general performance of transit systems across 294 Urbanized Areas (UZAs) in the US, which were stratified into six peer groups based on population. Transit efficiency and effectiveness were compared by developing a composite business efficiency index score and a composite service effectiveness index score for each urbanized area. The ...


Peer-To-Peer Carsharing: Short-Term Effects On Travel Behavior In Portland, Or, Jennifer Dill, Nathan McNeil, Steven Howland 2017 Portland State University

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

Jennifer Dill

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 ...


Report_Seam_2017_01.Pdf, Rakesh K. Goel 2017 California Polytechnic State University - San Luis Obispo

Report_Seam_2017_01.Pdf, Rakesh K. Goel

Rakesh K. Goel

This study focuses on developing a simple, yet accurate, procedure to estimate seismic forces in ancillary components and nonbuilding structures (secondary systems) supported on piers, wharves, and marine oil terminals (primary systems). Peirs, wharves, and marine oil terminals are generally one-level structures and can be idealized as single-degree-of-freedom (SDOF) systems. This study found that acceleration at the base of the secondary system is approximately equal to spectral acceleration at the fundamental period,, of the primary structure. This study also identifies several limitations of the current ASCE-7 provisions, such as under- or overestimation of the amplification factor.
Based on the findings ...


Designing For People In An Era Of Self-Driving Cars, William W. Riggs, Melissa Ruhl, Nico Larco 2017 Arup

Designing For People In An Era Of Self-Driving Cars, William W. Riggs, Melissa Ruhl, Nico Larco

William W. Riggs

There has been much dialogue of late on the role self-driving, autonomous vehicles will play in shaping the future of our cities. At the heart of this dialogue, planning and design professionals are trying to understand the part they will have in shaping urban form and designing sustainable cities. It seems certain that autonomous vehicles will change the way we live; therefore, planners and designers should work with even more dedication to mold our cities into the kinds of places in which we want to live.


Utilizing High Resolution Bus Gps Data To Visualize And Identify Congestion Hot-Spots In Urban, Nicholas B. Stoll, Travis B. Glick, Miguel Figliozzi 2017 Portland State University

Utilizing High Resolution Bus Gps Data To Visualize And Identify Congestion Hot-Spots In Urban, Nicholas B. Stoll, Travis B. Glick, Miguel Figliozzi

Miguel A. Figliozzi

Congestion and travel delay on urban roadways can influence the roadways’ operating costs and service attractiveness. This research used high-resolution bus data to examine sources of delay on urban arterials. A set of tools was created to help visualize trends in bus behavior and movement; these tools allowed larger traffic trends to be visualized along urban corridors and streets. With buses as probes and examining aggregated bus behavior, contoured speed plots were used to understand the behavior of roadways outside the zone of influence of bus stops. Speed plots were used to discover trends and travel patterns with only a ...


A Conceptual Framework For Understanding Latent Demand: Accounting For Unrealized Activities And Travel, Kelly Clifton 2017 Portland State University

A Conceptual Framework For Understanding Latent Demand: Accounting For Unrealized Activities And Travel, Kelly Clifton

Kelly Clifton

Latent demand—the activities and travel that are desired but unrealized because of constraints—have been historically examined from the standpoint of understanding the impacts of proposed capacity or service improvements on travel demand.

Drawing on work from a variety of theoretical perspectives, this paper presents a broader conceptual view of latent demand that provides a useful framework for researching and understanding these unmet needs. This is important from an equity standpoint, as it provides insights into to questions of transport disadvantage, social exclusion and poverty.

The framework presented here is theoretical in nature and untested empirically. This study aims ...


A Time-Series Forecasting Model For Windhoek Rainfall, Namibia, Godfrey T. Pazvakawambwa 2017 University of Namibia, Faculty of Engineering and IT

A Time-Series Forecasting Model For Windhoek Rainfall, Namibia, Godfrey T. Pazvakawambwa

Andrews Research Conference

The objective of the study was to use time series forecasting techniques to model Windhoek rainfall based on secondary monthly data from 1891 to 2011. Descriptive summary statistics in the form of measures of centrality and dispersion, time series plots, and autocorrelation functions were generated using R time series statistical software. The Box Jenkin’s ARIMA modelling procedure (model identification, model estimation, model validation) was used to determine the best models for the data. Model diagnostics based on residual analysis were performed to assess the adequacy of the identified models. The final model was then used to forecast monthly rainfall ...


Network Congestion Effect Of E-Hailing Transportation Services, Xuegang Ban 2017 University of Washington

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

TREC Friday Seminar Series

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.


Estimation Of Cavity Pressures In Air-Permeable, Multi-Layer Systems Using A Lumped-Leakage Approach, Rahul Prabhakaran Nair Sreedevi 2017 The University of Western Ontario

Estimation Of Cavity Pressures In Air-Permeable, Multi-Layer Systems Using A Lumped-Leakage Approach, Rahul Prabhakaran Nair Sreedevi

Electronic Thesis and Dissertation Repository

For conventional buildings, the proper estimation of wind-induced pressures on the external façade, the roof surface, or the net pressures across elements like a canopy or parapet, which are exposed to wind on both sides, can be easily done using conventional wind tunnel tests. But in the case of air-permeable multi-layer systems, which have gaps or porosity in the external layer along with a cavity between the external and inner layers, the estimation of wind loading across the external layer or in the inner cavity by wind tunnel tests can be quite difficult due to practical difficulties in exactly simulating ...


Monitoring Of Applied Stress In Concrete Using Ultrasonic Full-Waveform Comparison Techniques, Ali Hafiz 2017 Portland State University

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 ...


Fe Analysis Of Alternative Thermal Breaks For Steel Buildings, Salih Q. Mahmood 2017 Portland State University

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 ...


Behavior-Based Freight Modeling At Metro, Chris Johnson, Bud Reiff 2017 Metro

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

TREC Friday Seminar Series

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 ...


Netpoint®, Purdue ECT Team 2017 Construction Engineering & Management, Purdue University

Netpoint®, Purdue Ect Team

ECT Fact Sheets

The vast majority of construction scheduling software uses a combination of spreadsheets and Gantt charts for developing and depicting Critical Path Method (CPM) schedules. While this paradigm works for the expert scheduler, it is not conducive to collaboration, and it is prohibitively difficult for non-scheduling experts to understand.

NetPoint® provides a dynamic, visual interface conducive to touch and gestural input. Activities are drawn directly on a time-scale and may be placed on the same row or arranged automatically using codes or the WBS. Such control of the presentation makes it easier to communicate the plan to any type of audience ...


Fluid Isolator, Purdue ECT Team 2017 Construction Engineering & Management, Purdue University

Fluid Isolator, Purdue Ect Team

ECT Fact Sheets

The reliability of concrete infrastructure is vital to ensuring daily life, as well as commerce, can progress without interruption. From the pavement of interstate highways to the driveways and sidewalks in a local neighborhood, concrete is expensive to install and often even more expensive, and intrusive, when it needs to be replaced. Unfortunately, to maintain functionality in winter climates concrete is heavily exposed to deicing salts. This not only affects the roads, driveways, and sidewalks where salt is applied directly, but many other areas such as parking and residential garages where vehicles (and people) will track salt along with water ...


Impact Of Using Spatially Distributed Soils Information On Flood Hydrograph Simulation With Hec-Hms, Matthew J. Nelson 2017 University of Nebraska-Lincoln

Impact Of Using Spatially Distributed Soils Information On Flood Hydrograph Simulation With Hec-Hms, Matthew J. Nelson

Civil Engineering Theses, Dissertations, and Student Research

Hydrologic rainfall-runoff models employ numerical equations to simulate the soil absorption of rainfall and resulting runoff. A number of methods have been developed to model these processes, but the parameters used to define these methods can be difficult to directly measure due to the variable nature of soil properties. They often rely on estimation of hydraulic and hydrologic parameters and calibration to produce accurate results.

A challenge with runoff method parameterization is the need for oversimplification using a lumped modeling approach. While distributed hydrologic modeling techniques are now available, distributed runoff methods are limited in use due to the tradition ...


Robust Drought Planning In Megacities: A Case Study In São Paulo, Brazil, Grace Cambareri 2017 University of Massachusetts Amherst

Robust Drought Planning In Megacities: A Case Study In São Paulo, Brazil, Grace Cambareri

Environmental & Water Resources Engineering Masters Projects

The megacity of São Paulo, Brazil recently faced a severe three-year drought (2013- 2015) that highlighted the challenges of growing water demands, unpredictability of future supply, and proper communication with the public during crisis. Given the poor outcomes of the recent drought, the question remains as to how the drought can be used to inform and improve future drought preparedness. This study develops a seven-step framework using simulation and a computational search to identify promising drought plans based on the historic record. These promising plans are then tested under alternative states of the world to explore their robustness and identify ...


Pilot Reactor Operation Of The Oxygenic Photogranule (Opg) Wastewater Treatment Process, Adam Matthew McNair 2017 University of Massachusetts Amherst

Pilot Reactor Operation Of The Oxygenic Photogranule (Opg) Wastewater Treatment Process, Adam Matthew Mcnair

Environmental & Water Resources Engineering Masters Projects

Treating wastewater is imperative for maintaining public health and sanitation as well as the natural environment. In the United States and developed countries around the globe, the activated sludge (AS) process has been paramount in effectively treating wastewater for over a century. However, high energy consumption due to required mechanical aeration of AS limits its potential as a sustainable process. The oxygenic photogranule (OPG) wastewater treatment process utilizes the photosynthetic ability of OPGs made possible by the symbiosis between heterotrophic AS and filamentous cyanobacteria and algae in dense, spherical biogranules. This research presents pilot operation of the OPG wastewater treatment ...


Bias And Other Error In Gridded Weather Data Sets And Their Impacts On Estimating Reference Evapotranspiration, Philip A. Blankenau 2017 University of Nebraska-Lincoln

Bias And Other Error In Gridded Weather Data Sets And Their Impacts On Estimating Reference Evapotranspiration, Philip A. Blankenau

Civil Engineering Theses, Dissertations, and Student Research

Gridded weather data sets are increasingly used in a variety of hydrologic and agricultural applications due to their complete spatial and temporal coverage. One application of gridded data sets is the estimation of evapotranspiration (ET). Several operational remote sensing (RS) approaches for estimating ET, such as the SEBAL, METRIC and EEFlux models, require estimates of reference ET (ETref), where ETref is expected ET from a hypothetical reference crop of clipped grass or alfalfa. Gridded weather data provide for the computation of ETref in all areas of a remote sensing image, and therefore potentially remove the need for dense weather station ...


Reference Evapotranspiration From Coarse-Scale And Dynamically Downscaled Data In Complex Terrain: Sensitivity To Interpolation And Resolution, Courtenay Strong, Krishna B. Khatri, Adam K. Kochanski, Clayton S. Lewis, L. Niel Allen 2017 University of Utah

Reference Evapotranspiration From Coarse-Scale And Dynamically Downscaled Data In Complex Terrain: Sensitivity To Interpolation And Resolution, Courtenay Strong, Krishna B. Khatri, Adam K. Kochanski, Clayton S. Lewis, L. Niel Allen

CEE Faculty Publications

The main objective of this study was to investigate whether dynamically downscaled high resolution (4-km) climate data from the Weather Research and Forecasting (WRF) model provide physically meaningful additional information for reference evapotranspiration (E) calculation compared to the recently published GridET framework that uses interpolation from coarser-scale simulations run at 32-km resolution. The analysis focuses on complex terrain of Utah in the western United States for years 1985–2010, and comparisons were made statewide with supplemental analyses specifically for regions with irrigated agriculture. E was calculated using the standardized equation and procedures proposed by the American Society of Civil Engineers ...


Evaluation Of Phosphorous Removals By Biochar Supported Nano-Scale Zero-Valent Iron, Maria S. Rossetti 2017 University of Arkansas

Evaluation Of Phosphorous Removals By Biochar Supported Nano-Scale Zero-Valent Iron, Maria S. Rossetti

Chemical Engineering Undergraduate Honors Theses

This study evaluated the effectiveness of biochar-supported nano-scale zero-valent iron (nZVI/BC) in removing phosphorus (P) from water. Samples of nZVI/BC were prepared using aqueous nanoparticles synthesis techniques, and were mixed with a stock phosphorus solution. To determine P reductions water samples were tested for P content using the ascorbic acid method. This procedure was repeated for samples of stock P solution, zero-valent iron (ZVI), biochar, and ZVI/BC. nZVI/BC reduced P content by 86% whereas ZVI, biochar, and ZVI/BC removed 6%, -23%, and 17% respectively. This suggests that nZVI/BC has the potential to be an ...


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