Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Entire DC Network

Investigating Factors Affecting Road Freight Overloading Through The Integrated Use Of Blr And Cart: A Case Study In China, Yikai Chen, Kai Wang, Yu Zhang, Renjia Luo, Shujun Yu, Qin Shi, Wenting Hu Jan 2020

Investigating Factors Affecting Road Freight Overloading Through The Integrated Use Of Blr And Cart: A Case Study In China, Yikai Chen, Kai Wang, Yu Zhang, Renjia Luo, Shujun Yu, Qin Shi, Wenting Hu

Civil and Environmental Engineering Faculty Publications

Overloading of road freight vehicles accelerates road damage, creates unfair competition in the transport market, and increases safety risk. There is a dearth of research on the mining of data of highway Freight Weight (FW), and this paper therefore aims to discover factors affecting road freight overloading based on highway FW data, with a view of developing strategies to mitigate such occurrences. A comprehensive sampling survey of road freight transportation was conducted in Anhui Province (China). Vehicle Characteristics (VC), Operation Mode (OM), and transportation information from a total of 3248 trucks were collected. In order to take advantage of the …


A Route Navigation Algorithm For Pedestrian Simulation Based On Grid Potential Field, Minghua Li, Yun Wei, Yan Xu Jan 2019

A Route Navigation Algorithm For Pedestrian Simulation Based On Grid Potential Field, Minghua Li, Yun Wei, Yan Xu

Civil and Environmental Engineering Faculty Publications

Pedestrian simulation modeling has become an important means to study the dynamic characters of dense populations. In the continuous pedestrian simulation model for complex simulation scenario with obstacles, the pedestrian path planning algorithm is an indispensable component, which is used for the calculation of pedestrian macro path and microscopic movement desired direction. However, there is less efficiency and poor robustness in the existing pedestrian path planning algorithm. To address this issue, we propose a new pedestrian path planning algorithm to solve these problems in this article. In our algorithm, we have two steps to determine pedestrian movement path, that is, …


Analysis Of Truck-Related Crashes Of Freeways In China, Ting Xu, Rui-Sen Jiang, Lei Zhao, Long Qi, Yu Zhang Jan 2019

Analysis Of Truck-Related Crashes Of Freeways In China, Ting Xu, Rui-Sen Jiang, Lei Zhao, Long Qi, Yu Zhang

Civil and Environmental Engineering Faculty Publications

Truck-related crashes result in tremendous lives and property loss and become a serious safety issue in China. The goal of this article is to identify the influential factors for severity of truck-related crashes using data from Jingjintang freeways in China and to design an ordered probit model to explore their relationship. Records including crashes, traffic flow attributes, and geometric design features ranging from 2009 to 2012 were collected from Jingjintang freeway. Crashes are divided into three severity levels: slight injury, injury, and fatal injury. The injury crashes is ranking the first place occupying 64.37%. Truck-related crashes are likely to occur …


Future Climate And Land Use Change Impacts On River Flows In The Tapajós Basin In The Brazilian Amazon, Fabio Farinosi, Mauricio E. Arias, Eunjee Lee, Marcos Longo, Fabio F. Pereira, Angela Livino, Paul R. Moorcroft, John Briscoe Jan 2019

Future Climate And Land Use Change Impacts On River Flows In The Tapajós Basin In The Brazilian Amazon, Fabio Farinosi, Mauricio E. Arias, Eunjee Lee, Marcos Longo, Fabio F. Pereira, Angela Livino, Paul R. Moorcroft, John Briscoe

Civil and Environmental Engineering Faculty Publications

Land conversion and changing climate are expected to significantly alter tropical forest hydrology. We used a land surface model integrated with a river routing scheme to analyze the hydrological alterations expected in the Tapajós River basin, a large portion of the Brazilian Amazon, caused by two environmental drivers: climate and land use. The model was forced with two future climate scenarios (years 2026–2045) from the Earth System Model HadGem2-ES with moderate (+4.5 W/m2 radiative forcing value in the year 2100 with respect to preindustrial levels) and severe (+8.5 W/m2) representative atmospheric carbon dioxide pathways (Representative Concentration Pathways). …


Delay Causality Network In Air Transport Systems, Wen-Bo Du, Ming-Yuan Zhang, Yu Zhang, Xian-Bin Cao, Jun Zhang Oct 2018

Delay Causality Network In Air Transport Systems, Wen-Bo Du, Ming-Yuan Zhang, Yu Zhang, Xian-Bin Cao, Jun Zhang

Civil and Environmental Engineering Faculty Publications

To better understand the mechanism of flight delay propagation at the system-level, we built a delay causality network (DCN) based on the Granger causality test. Through topological analysis of DCNs, we found that only about a quarter of airports were involved in delay propagation during the peak travel period and large airports affected by many upstream airports impact fewer downstream airports. Furthermore, temporal analysis of DCNs indicates that the culprits of delay propagation in the air transport system are not a fixed set of airports; instead, they vary daily depending on the operational environment.


Sociodemographics And Access To Organic And Local Food: A Case Study Of New Orleans, Louisiana, Chuo Li, Amir Ghiasi, Xiaopeng Li, Guangqing Chi Sep 2018

Sociodemographics And Access To Organic And Local Food: A Case Study Of New Orleans, Louisiana, Chuo Li, Amir Ghiasi, Xiaopeng Li, Guangqing Chi

Civil and Environmental Engineering Faculty Publications

This study examined the association between physical accessibility to organic and local food, and sociodemographic factors in New Orleans, Louisiana. Spatial regression models were used to investigate how sociodemographic variables such as income, race/ethnicity, education, and age correlate with driving, bicycling, and walking distances to stores that sell organic or local food. The distances were calculated from GIS and real-time speed information from Google Maps. The results indicated that physical access to such stores is positively associated with population density, median housing value, education, non-Hispanic Blacks, and Hispanics, and is negatively associated with median housing age. We found no disparities …


Material Transport Under A Wave Train In Interaction With Constant Wind: A Eulerian Rans Approach Combined With A Lagrangian Particle Dispersion Model, Nityanand Sinha, Roozbeh Golshan Jun 2018

Material Transport Under A Wave Train In Interaction With Constant Wind: A Eulerian Rans Approach Combined With A Lagrangian Particle Dispersion Model, Nityanand Sinha, Roozbeh Golshan

Civil and Environmental Engineering Faculty Publications

The interaction of a developed train of gravity deep water waves with suddenly applied winds is investigated in this manuscript. The direction of the wind is the same as that of the wave train (i.e., following) and its imposed surface shear stress is constant and steady. The focus of this study is on a micro-scale water wave field where the time scale is on the order of ten wave periods and the length scale is on the order of ten wave lengths. Accurate 2D Reynolds-averaged Navier–Stokes (RANS) multi-phase simulations of Navier–Stokes equations are performed in a Eulerian framework to capture …


Safety Assessment And Risk Estimation For Unmanned Aerial Vehicles Operating In National Airspace System, Xuejun Zhang, Yang Liu, Yu Zhang, Xiangmin Guan, Daniel Delahaye, Li Tang Jan 2018

Safety Assessment And Risk Estimation For Unmanned Aerial Vehicles Operating In National Airspace System, Xuejun Zhang, Yang Liu, Yu Zhang, Xiangmin Guan, Daniel Delahaye, Li Tang

Civil and Environmental Engineering Faculty Publications

This paper proposes an effective approach for modelling and assessing the risks associated with unmanned aerial vehicles (UAVs) integrated into national airspace system (NAS). Two critical hazards with UAV operations are considered and analyzed, which are ground impacts and midair collisions. Threats to fatalities that result from the two hazards are the focus in the proposed method. In order to realize ground impact assessment, a multifactor risk model is designed by calculating system reliability required to meet a target level of safety for different UAV categories. Both fixed-wing and rotary-wing UAVs are taken into account under a real scenario that …


Oil Droplet Transport Under Non-Breaking Waves: An Eulerian Rans Approach Combined With A Lagrangian Particle Dispersion Model, Roozbeh Golshan, Michel C. Boufadel, Victor A. Rodriguez, Xiaolong Geng, Feng Gao, Thomas King, Brian Robinson, Andres E. Tejada-Martinez Jan 2018

Oil Droplet Transport Under Non-Breaking Waves: An Eulerian Rans Approach Combined With A Lagrangian Particle Dispersion Model, Roozbeh Golshan, Michel C. Boufadel, Victor A. Rodriguez, Xiaolong Geng, Feng Gao, Thomas King, Brian Robinson, Andres E. Tejada-Martinez

Civil and Environmental Engineering Faculty Publications

Oil droplet transport under a non-breaking deep water wave field is investigated herein using Computational Fluid dynamics (CFD). The Reynolds-averaged Navier–Stokes (RANS) equations were solved to simulate regular waves in the absence of wind stress, and the resulting water velocities agreed with Stokes theory for waves. The RANS velocity field was then used to predict the transport of buoyant particles representing oil droplets under the effect of non-locally generated turbulence. The RANS eddy viscosity exhibited an increase with depth until reaching a maximum at approximately a wave height below the mean water level. This was followed by a gradual decrease …


Advances In Modelling Connected And Automated Vehicles, Xiaobo Qu, Xiaopeng Li, Meng Wang, Vinayak Dixit Jan 2017

Advances In Modelling Connected And Automated Vehicles, Xiaobo Qu, Xiaopeng Li, Meng Wang, Vinayak Dixit

Civil and Environmental Engineering Faculty Publications

No abstract provided.


Planning For Climate Change: The Need For Mechanistic Systems-Based Approaches To Study Climate Change Impacts On Diarrheal Diseases, Jonathan E. Mellor, Karen Levy, Julie Zimmerman, Mark Elliott, Jamie Bartram, Elizabeth Carlton, Thomas Clasen, Rebecca Dilingham, Joseph Eisenberg, Richard Guerrant, Daniele Lantagne, James Mihelcic, Kara Nelson Apr 2016

Planning For Climate Change: The Need For Mechanistic Systems-Based Approaches To Study Climate Change Impacts On Diarrheal Diseases, Jonathan E. Mellor, Karen Levy, Julie Zimmerman, Mark Elliott, Jamie Bartram, Elizabeth Carlton, Thomas Clasen, Rebecca Dilingham, Joseph Eisenberg, Richard Guerrant, Daniele Lantagne, James Mihelcic, Kara Nelson

Civil and Environmental Engineering Faculty Publications

Increased precipitation and temperature variability as well as extreme events related to climate change are predicted to affect the availability and quality of water globally. Already heavily burdened with diarrheal diseases due to poor access to water, sanitation and hygiene facilities, communities throughout the developing world lack the adaptive capacity to sufficiently respond to the additional adversity caused by climate change. Studies suggest that diarrhea rates are positively correlated with increased temperature, and show a complex relationship with precipitation. Although climate change will likely increase rates of diarrheal diseases on average, there is a poor mechanistic understanding of the underlying …


Determining Travel Behaviour In Petaling Jaya, Malaysia, Ahmed M. Mohammed, Hussain Dhafir Hussain, Ali Dawod Salman, Riza Rahmat, Nazri Burhan Jan 2015

Determining Travel Behaviour In Petaling Jaya, Malaysia, Ahmed M. Mohammed, Hussain Dhafir Hussain, Ali Dawod Salman, Riza Rahmat, Nazri Burhan

Civil and Environmental Engineering Faculty Publications

Petaling Jaya is a Malaysian city in the Petaling district of Selangor, over the past few years it has witnessed a dramatic growth in terms of population size and geographical importance. This has led to constant congestions throughout the city. A significant reduction in the annual cost of road accidents, congestion, energy consumption and pollution in the city can be obtained by implementing a modal shift from private vehicles to public transport. Urban transportation problems are highlighted in this study as well the factors that influence the use of private and public transportation. A survey was carried out on users …


Estimation Of Evapotranspiration And Water Budget Components Using Concurrent Soil Moisture And Water Table Monitoring, Mandana Rahgozar, Nirjhar Shah, Mark Ross Jan 2012

Estimation Of Evapotranspiration And Water Budget Components Using Concurrent Soil Moisture And Water Table Monitoring, Mandana Rahgozar, Nirjhar Shah, Mark Ross

Civil and Environmental Engineering Faculty Publications

Simultaneous measurements of soil moisture profiles and water table heads, along a flow path, were used to determine evapotranspiration (ET) along with other components of the water budget. The study was conducted at a small-scale (~0.8 Km2) hydrologic monitoring field site in Hillsborough County, Florida, from January 2002 to June 2004. Frequency Domain Reflectometry soil moisture probes, installed in close proximity to water table monitoring wells were used to derive changes in the soil water storage. A one-dimensional transect model was developed; changes in the soil water storage and water table observations served as input to determine all vertical and …


Remote Monitoring Of Bridges, Rajan Sen, Gray Mullins, Alberto Sagues, Julio Aguilar, Danny Winters Jul 2011

Remote Monitoring Of Bridges, Rajan Sen, Gray Mullins, Alberto Sagues, Julio Aguilar, Danny Winters

Civil and Environmental Engineering Faculty Publications

This report summarizes findings from a 24-month study in which the performance of cathodic protection systems for substructures of two interstate bridges was remotely monitored. The two bridges #860050 and #860054 are located on the “Alligator Alley” toll portion of eastbound I-75 in Broward County, FL. Each bridge spans two pilesupported piers inside a drainage canal. The seven steel H-piles supporting the piers are jacketed in concrete to a level just below the water surface and are cathodically protected by three magnesium anodes spaced uniformly over their submerged length.