conference paper
RAMP: Impact of rule based aggregator business model for residential microgrid of prosumers including distributed energy resources
ISGT 2014
Publication Date
February 1, 2014
Archives: Research Products
Phd Dissertation
A Comparative Study of Entrepreneurial Strategies among African American and Latino Truckers in the Los Angeles and Long Beach Ports
Publication Date
June 30, 1994
Author(s)
Areas of Expertise
Abstract
This study examines the entrepreneurial strategies of African-American and Latino owner-operators in the container hauling sector of the Los Angeles trucking industry. The research proceeded in two stages. In the first, I estimated the ethnic representation of owner-operators and found Latinos to be significantly more represented than other groups. In the second, a snowball sample was used to identify 54 respondents who were interviewed regarding their business behavior and attitudes. The data were analyzed using traditional descriptive statistics as well as multidimensional scaling techniques. The analysis revealed several differences between African-Americans, non-immigrant Latinos, and immigrant Latinos. They differed in the ways they used social networks and co-ethnic support systems. There were more partnerships than expected among African-Americans and more loans and free labor from non-kin co-ethnics for Latinos. Also a higher proportion of immigrants than expected was found among Latinos. The findings of this study lend support to reactive cultural theories and labor market segmentation theories. African-Americans depended heavily on nuclear family partnerships. Both groups were heavily dependent on Latino immigrant labor in the informal sector for employees. A macro analysis suggests that the organization of labor in the harbor is evolving to create greater flexibility in an emerging NIDL (new international division of labor). This study concludes that immigrants out number non-immigrants because they are more flexible about rates and working conditions and not because of a greater tendency to network.
Suggested Citation
James Edward Smith (1994) A Comparative Study of Entrepreneurial Strategies among African American and Latino Truckers in the Los Angeles and Long Beach Ports. PhD Dissertation. UC Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991035092929604701.
published journal article
Suitable Bus Stop Locations for a Proposed Bus Rapid Transit Corridor in a Developing Country City: An Analytical Hierarchy Process Approach
Transportation in Developing Economies
Publication Date
March 14, 2023
Author(s)
Md Musfiqur Rahman Bhuiya, Rezwana Rafiq, Khandaker Nabid Md Morshed, M. Imtiaz Rahman
Abstract
Bangladesh is one of the world’s most densely populated developing countries, and so is its capital Dhaka, where ever-growing travel demand is causing congestion and numerous other transportation problems. To improve the situation, the “Strategic Transport Plan for Dhaka (STP)” was conceptualized in 2005 with the plan of developing mass transit systems (buses and rail), which was revised in 2016. The revised STP proposes two BRT bus routes for Dhaka city: BRT Line 3 and 7. Bus stops on the proposed routes are the ultimate point locations where people at large will access these BRT services. Therefore, determining the locations of bus stops is crucial for these proposed routes’ overall efficiency and accessibility. In this study, we proposed a bus stop selection technique for the BRT Line 3 in Dhaka, which considers multi-variate influencing factors, including travel demand, population density, land use, accessibility of pedestrians, and accessibility of rickshaws. We collected data on these factors through a field survey for 77 intersections along the study route. After that, a composite score is assigned for each study intersection based on the five factors’ relative value and priority weights obtained via the Analytical Hierarchical Process technique. Finally, based on the composite score and selection criteria, we suggested 25–40 intersections for suitable bus stop locations along the study route. The methodology used in this study to select suitable bus stop locations will provide citizens with better utilization and transit experience as envisioned by the BRT routes.
Suggested Citation
Md Musfiqur Rahman Bhuiya, Rezwana Rafiq, Khandaker Nabid Md Morshed and M. Imtiaz Rahman (2023) “Suitable Bus Stop Locations for a Proposed Bus Rapid Transit Corridor in a Developing Country City: An Analytical Hierarchy Process Approach”, Transportation in Developing Economies, 9(1), p. 10. Available at: 10.1007/s40890-023-00179-6. published journal article
Estimating impacts of emission specific characteristics on vehicle operation for quantifying air pollutant emissions and energy use
Journal of Traffic and Transportation Engineering (English Edition)
Publication Date
June 1, 2017
Suggested Citation
K.S. Nesamani, Jean-Daniel Saphores, Michael G. McNally and R. Jayakrishnan (2017) “Estimating impacts of emission specific characteristics on vehicle operation for quantifying air pollutant emissions and energy use”, Journal of Traffic and Transportation Engineering (English Edition), 4(3), pp. 215–229. Available at: 10.1016/j.jtte.2017.05.007. Phd Dissertation
Broadcasting in Vehicular Ad Hoc Networks
Publication Date
January 1, 2010
Associated Project
Author(s)
Areas of Expertise
Abstract
Traffic congestion and accidents continue to take a toll on our society with congestion causing billions of dollars in economic costs and millions of traffic accidents annually worldwide. For many years now, transportation planners have been pursuing an aggressive agenda to increase road safety through Intelligent Transportation System initiatives. Vehicular Ad Hoc Network (VANET) based information systems have considerable promise for improving traffic safety, reducing congestion and increasing environmental efficiency of transportation systems. To achieve the future road safety vision, time-sensitive, safety-critical applications in vehicular communication networks are necessary. However, there are numerous technical hurdles for deploying VANET on the road network and its full potential will not be realized until the issues related to communication reliability, delay and security are solved. VANET is a specific type of mobile ad hoc network (MANET) with unique characteristics that are different from a general MANET. These attributes include the traffic conditions (network density), mobility model (vehicle movements) and the network topology (road layout) imposed by the underlying transportation system. When disseminating data in VANET the communication system is faced with the scalability problem in dense networks and the connectivity issue in sparse ones. In this dissertation, we study broadcasting for VANET that are applicable to traffic safety applications. We investigate ways to improve reliability and reduce delay under numerous traffic conditions (free flow and congested flow traffic scenarios). Further, we incorporate vehicular traffic information to increase the communication efficiency in dynamic vehicular networks while mitigating the broadcast storm problem. We believe that the contributions in this dissertation will be of interest for both the computer networking and transportation research communities.
Suggested Citation
Rex Chen (2010) Broadcasting in Vehicular Ad Hoc Networks. PhD Dissertation. University of California, Irvine. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991007365949704701 (Accessed: October 12, 2023).Related Publications
published journal article |
Jan 2010
Broadcasting safety information in vehicular networks: Issues and approaches
IEEE Network
published journal article
Predicting the market penetration of electric and clean-fuel vehicles
Science of The Total Environment
Publication Date
June 1, 1993
Author(s)
Thomas Golob, Ryuichi Kitamura, Mark Bradley, David Bunch
Abstract
Air quality in Southern California and elsewhere could be substantially improved if some gasoline-powered personal vehicles were replaced by vehicles powered by electricity or alternative fuels, such as methanol, ethanol, propane, or compressed natural gas. Quantitative market research information about how consumers are likely to respond to alternative-fuel vehicles is critical to the development of policies aimed at encouraging such technological change. In 1991, a three-phase stated preference (SP) survey was implemented in the South Coast Air Basin of California to predict the effect on personal vehicle purchases of attributes that potentially differentiate clean-fuel vehicles from conventional gasoline (or diesel) vehicles. These attributes included: limited availability of refueling stations, limited range between refueling or recharging, vehicle prices, fuel operating costs, emissions levels, multiple-fuel capability and performance. Respondents were asked to choose one vehicle from each of five sets of hypothetical clean-fuel and conventional gasoline vehicles, each vehicle defined in terms of attributes manipulated according to a specific experimental design. Discrete choice models, such as the multinominal logit model, are then used to estimate how the values of the attribute levels influence purchase decisions. The SP survey choice sets were customized to each respondent’s situation, as determined in the preceding phase of the survey. The final phase of the survey involved fuel-choice SP tasks for multi-fuel vehicles that can run on either clean fuels or gasoline. Preliminary results from a pilot sample indicate that the survey responses are plausible and will indeed be useful for forecasting.
Suggested Citation
Thomas F Golob, Ryuichi Kitamura, Mark Bradley and David S Bunch (1993) “Predicting the market penetration of electric and clean-fuel vehicles”, Science of The Total Environment, 134(1-3), pp. 371–381. Available at: 10.1016/0048-9697(93)90367-f. published journal article
Automated time activity classification based on global positioning system (GPS) tracking data
Environmental health : a global access science source
Publication Date
November 1, 2011
Author(s)
Jun Wu, Chengsheng Jiang, Doug Houston, Dean Baker, Ralph Delfino
Suggested Citation
Jun Wu, Chengsheng Jiang, Douglas Houston, Dean Baker and Ralph Delfino (2011) “Automated time activity classification based on global positioning system (GPS) tracking data”, Environmental health : a global access science source, 10(1). Available at: 10.1186/1476-069x-10-101. research report
Policy and Literature Review on the Effect Millennials Have on Vehicle Miles Traveled, Greenhouse Gas Emissions, and the Built Environment
Publication Date
June 1, 2017
Associated Project
Author(s)
Areas of Expertise
Abstract
Vehicle travel has reduced substantially across all demographics in the 2000’s, but millennials or young adults born from 1985-2000 stand out as the group that has reduced vehicle travel the most. This reduction of travel among millennials is known as the millennial effect. This policy and literature review discusses insights from recent policy reports and literature regarding the millennial effect and identifies the prominent themes and gaps in our knowledge. The first section reviews existing research on the millennial effect on vehicle miles traveled (VMT). The second section discusses the influence of the built environment on the travel and activities of the millennial generation. The third section highlights scenarios describing the millennials effect’s potential magnitude and identifies topics for consideration in future scenario planning efforts. The final section discusses the uncertainty that exists regarding the future behavior of millennials and their influence on VMT and greenhouse gas emissions.
Suggested Citation
Stephen G. Ritchie, Doug Houston and Michelle E. Zuñiga (2017) Policy and Literature Review on the Effect Millennials Have on Vehicle Miles Traveled, Greenhouse Gas Emissions, and the Built Environment. Available at: https://escholarship.org/uc/item/8dc5g9d8 (Accessed: October 11, 2023). published journal article
A generalized diffusion model for preference and response time: Application to ordering mobility-on-demand services
Transportation Research Part C: Emerging Technologies
Publication Date
December 1, 2020
Author(s)
Abstract
The goal of this research study is to model user preferences and response times (RTs) jointly in the context of Mobility-on-Demand (MOD) services under different MOD operator pricing schemes, information frames, and pressure levels. MOD operators’ information provision, delay, and vehicle allocation strategies influence users’ preferences and RTs, which, in turn, affect which operational and information provision strategies are optimal for MOD operators. Evidence shows that preferences and RTs are sensitive to precedent decisions, information frames, risk, and time pressure. These dynamic interplaying factors are challenging to capture using a traditional discrete choice modeling framework. Hence, this study proposes a generalized diffusion model based on Decision Field Theory (DFT), multi-attribute Prospect Theory (PT), and Random Utility Theory to model these various interplaying factors. This study applies the proposed modeling approach in the context of ordering Shared-use Automated Vehicle Mobility Services (SAMS). Sensitivity analyses explore the impacts of various inputs and model parameters such as initial waiting time estimate, updated waiting time estimate, time pressure, loss aversion, and value-of-time on preferences and RTs. The proposed model can provide value to MOD operators in terms of information provision and pricing strategies. Moreover, the proposed model can assist policymakers and planners interested in the system impacts of MOD services and regulating MOD information provision and pricing strategies. The modeling framework can extend to other applications where multiple sub-decisions are necessary to make a single (travel) choice under information update, framing, risk, and time pressure.
Suggested Citation
Jiangbo Yu and Michael F. Hyland (2020) “A generalized diffusion model for preference and response time: Application to ordering mobility-on-demand services”, Transportation Research Part C: Emerging Technologies, 121, p. 102854. Available at: 10.1016/j.trc.2020.102854. research report
Resilience and Validation of GNSS PNT Solutions
Publication Date
November 20, 2023
Author(s)
Todd E. Humphreys, Qi Alfred Chen, Umit Ozguner, Charles Toth
Abstract
Highly automated transportation systems rely on a steady stream of signals and information from external sources for localization, route planning, perception, and general situational awareness. This includes reliance on positioning, navigation, and timing (PNT) information: Location is essential autonomous navigation and planning; and accurate timing is a precondition for on-board sensor fusion, cooperative control, and management based on information from other vehicles or the infrastructure. It is crucial to identify schemes for GNSS signal authentication and resilience that are well-suited for highly autonomous vehicles (HAVs). HAVs require PVT sensing techniques that are resilient to unusual natural or accidental events and secure against deliberate attack.