published journal article
Archives: Research Products
conference paper
An Empirical Investigation of the Dynamic Processes on Activity Scheduling and Trip Chaining
43rd Annual Meeting of the Western Regional Science Association
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Author(s)
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Suggested Citation
Ming-Sheng Lee and Michael G. McNally (2004) “An Empirical Investigation of the Dynamic Processes on Activity Scheduling and Trip Chaining”. 43rd Annual Meeting of the Western Regional Science Association, Maui, HI. Available at: https://escholarship.org/uc/item/4nk4q801?conferencePaper.working paper
Population Uncertainty and the Timing of an Urban Transportation Infrastructure Investment
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Author(s)
Working Paper
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Abstract
This paper analyzes the impacts of stochastic population changes on the timing of an investment that reduces congestion in an open, monocentric city with fixed boundaries. Congestion pricing cannot be implemented, but a welfare-maximizing planner can buy land and build transportation infrastructure. Under certainty, I derive a rule of thumb to evaluate infrastructure investments that corrects a standard benefit-cost analysis. Under uncertainty, I show that relying on a standard benefit-cost ratio could lead to investing in bad projects, or investing prematurely, or ignoring attractive projects because of population barriers and the impacts of the congestion externality on the land market.
Suggested Citation
Jean-Daniel M. Saphores (2006) Population Uncertainty and the Timing of an Urban Transportation Infrastructure Investment. Working Paper UCI-ITS-WP-06-1. Institute of Transportation Studies, Irvine. Available at: https://escholarship.org/uc/item/3kg8g9z4.published journal article
Nonstandard second-order formulation of the LWR model
Transportmetrica B: Transport Dynamics
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Abstract
In this study, we present an equivalent second-order formulation of the LWR model based on Phillips’ model, in which the acceleration rate equals a relaxation term with an infinitesimal relaxation time. We convert the model into a continuum car-following model and demonstrate its equivalence to that of the LWR model. We demonstrate that the nonstandard second-order model is stable, but the original Phillips model is not. We derive conditions for the nonstandard model to be forward-traveling and collision-free, prove that the collision-free condition is consistent with but more general than the CFL condition, and demonstrate that only anisotropic and symplectic Euler discretization methods lead to physically meaningful solutions. Numerically, the nonstandard second-order model has the same shock and rarefaction wave solutions as the LWR model for both Greenshields and triangular fundamental diagrams; for a non-concave fundamental diagram, the collision-free condition, but not the CFL condition, yields physically meaningful results.
Suggested Citation
Wen-Long Jin (2019) “Nonstandard second-order formulation of the LWR model”, Transportmetrica B: Transport Dynamics, 7(1), pp. 1338–1355. Available at: 10.1080/21680566.2019.1617803.Phd Dissertation
Research universities as gateways the expanding roles of higher education institutions and their contribution to economic development
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Abstract
The past 30 years have witnessed a gradual expansion in the missions of many universities, and in the ways in which they contribute to local and regional economic development. While teaching and research continue to serve as the foundational core of most university missions, increased attention has been afforded to how universities, by their presence and functions, influence the spatial geographies of neighborhoods, cities, and regions. This dissertation research explores the changing roles of research universities in small and medium-sized metropolitan areas with an emphasis on their impacts across the different geographical scales by investigating associations between university presence and (1) growth in foreign-born populations; (2) the attraction and retention of highly educated residents; and (3) student-driven neighborhood change dynamics. The findings of this dissertation extend previous studies emphasizing the increasing importance of higher education institutions to economic development activities at various scales. Results from metropolitan area level analyses demonstrate that counties with large research universities were associated with an increase in foreign-born residents following the 1990 Immigration and Naturalization Act, as well as an increase in highly educated residents in the 2000-2014 period. More specifically, while findings revealed that the presence of research universities generate significant spatial spillovers of highly educated residents from university host counties to metropolitan levels, there was little evidence of such spatially-explicit dynamics occurring amongst foreign-born residents. Furthermore, findings from neighborhood-level analyses indicated that proximity to large research university campuses may play an outsized role on the likelihood of neighborhoods undergoing studentification (i.e., student-driven neighborhood change) in the 2000-2014 period. These results may be indicative of a bifurcation of neighborhoods in university-dominant counties into wealthy and highly educated renter populations situated near the university campus, and relatively less wealthy and less educated homeowners residing on the further away from the campus or on the periphery of the county. By exploring university contributions beyond the spheres of research, teaching, and service contributions, this dissertation presents scholars, urban planners, and policymakers with a more comprehensive portrait of the relationship between universities and their host communities. The evidence of this work suggests that the evolving role of higher education institutions, including their role as gateways for new populations, should be reflected in policymaking which seeks to leverage the locational advantages of research universities for city building or revitalization efforts. Further, policymakers and planners should also be cognizant that scale matters when considering how higher education institutions can better serve their surrounding communities. The contributions of research universities should not be thought of as monolithic or uniform, but should rather be seen as presenting different opportunities and challenges at different geographical levels.
Suggested Citation
Nene, Osutei (2021) Research universities as gateways the expanding roles of higher education institutions and their contribution to economic development. PhD Dissertation. University of California, Irvine,. Available at: https://uci.primo.exlibrisgroup.com/permalink/01CDL_IRV_INST/17uq3m8/alma991035329641804701.published journal article
Protection or Peril of Following the Crowd in a Pandemic-Concurrent Flood Evacuation
Natural Hazards Review
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Author(s)
Abstract
AbstractThe decisions of whether and how to evacuate during a climate disaster are influenced by a wide range of factors, including emergency messaging, social influences, and sociodemographics. Further complexity is introduced when multiple hazards occur …
Suggested Citation
Elisa Borowski and Amanda Stathopoulos (2023) “Protection or Peril of Following the Crowd in a Pandemic-Concurrent Flood Evacuation”, Natural Hazards Review, 24(1), p. 04022045. Available at: 10.1061/(ASCE)NH.1527-6996.0000577.published journal article
DEVELOPMENT OF INCENTIVE CONTRACTS FOR TRANSIT MANAGEMENT
Transportation Research Record
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Author(s)
Suggested Citation
Subhash R Mundle, Janet E Kraus and Gordon J Fielding (1994) “DEVELOPMENT OF INCENTIVE CONTRACTS FOR TRANSIT MANAGEMENT”, Transportation Research Record [Preprint], (992). Available at: https://onlinepubs.trb.org/Onlinepubs/trr/1984/992/992-009.pdf.published journal article
Appraising Transportation Research
Transportation Research Circular
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Abstract
Public sector involvement in research is examined, with emphasis on the creation of incentives by government. In transportation, government investment in research is often a spark for improvements in overall economic productivity. This connection has been dubbed “the Virtuous Circle” and helps justify basic and applied research. Is research always justifiable from a societal perspective? The answer to this question is best approached with the application of cost-benefit analysis, or more specifically net present value (NPV). While NPV appears to be simple calculation yielding transparent solutions, a proper cost-benefit analysis requires careful construction of a base case as well as decisions on discount rates and indirect impacts. Sensitivity analysis is used to check the validity of the chosen assumptions. A case study of new, high speed rail technology illustrates how some of the concepts can be applied.
Suggested Citation
Linda R. Cohen, Gordon J Fielding, James F. Nolan and George C. Smith (1994) “Appraising Transportation Research”, Transportation Research Circular, (426), pp. 21--29.published journal article
Environmental Analysis of System-Wide Implementation of Delayed Deceleration Approach Procedures
Journal of Air Transportation
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Abstract
The potential of system-wide implementation of delayed deceleration approaches is presented through modeling a day of operations. Conventional approach procedures may involve early deceleration in the flight trajectory, resulting in early high-lift device deployment. Alternatively, delayed deceleration approaches involve delaying high-lift device deployment, thus maintaining higher airspeeds for longer and lowering thrust requirements, which reduces fuel burn and community noise. When implementing delayed deceleration approach procedures within traffic, the primary challenge is accrued from the variability of deceleration rates, which can significantly impact approach timing and thus separation among aircraft. In this work, a framework was developed that constructs delayed deceleration approach models based on observed radar data. This framework was then implemented on an average day at Boston Logan Airport to assess the feasibility of implementing delayed deceleration approaches on commercial traffic. The results indicate that delayed deceleration approaches can be implemented for 92.2% of the evaluated traffic without separation concerns, providing an average approach fuel burn savings of 10.27% and reducing exposure of configuration noise along the flight path by an average of 8.10 N miles of ground track distance. Therefore, implementing the delayed deceleration approach on a commercial traffic may provide environmental benefits.
Suggested Citation
Victoria R. Pellerito and Jacqueline L. Huynh (2024) “Environmental Analysis of System-Wide Implementation of Delayed Deceleration Approach Procedures”, Journal of Air Transportation, 32(3), pp. 146–154. Available at: 10.2514/1.D0345.conference paper