A Copula-Based Joint Model of Commute Mode Choice and Number of Non-Work Stops during the Commute

At the time of publication A. Portoghese, E. Spissu, and I. Meloni were at University of Cagliari, and C.R. Bhat and N. Eluru were at the University of Texas at Austin.In this paper, in the spirit of a tour-based frame of analysis, we examine the commute mode choice and the number of non-work stops during the commute. Understanding the mode and activity stop dimensions of weekday commute travel is important since the highest level of weekday traffic congestion in urban areas occurs during the commute periods. The paper employs a copula-based joint multinomial logit – ordered modeling framework in which commute mode choice is modeled using a multinomial logit formulation and the number of commute stops is modeled using an ordered response formulation. The data used in this study are drawn from the “Time use” multipurpose survey conducted between 2002 and 2003 by the Turin Town Council and the Italian National Institute of Statistics (ISTAT) in the Greater Turin metropolitan area of Italy. The results highlight the importance of accommodating the inter-relationship between commute mode choice and commute stops behavior. The results also point to the stronger effect of household responsibilities and demographic characteristics in the Italian context compared to the US context.Civil, Architectural, and Environmental Engineerin

Analysis and Evaluation of Existing C-Band Feed Horns for Applicability to the 21 Meter Morehead Space Tracking Antenna

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Prabhakara Rao Eluru on October 8, 2008

How bicycling sharing system usage is affected by land use and urban form: analysis from system and user perspectives

There is a rapid growth of bicycle-sharing systems (BSS) around the world. Cities are supporting these systems as a more sustainable transport mode for short trips. Given the relatively recent adoption of BSS, there is substantial interest in understanding how these systems impact urban transportation. In this paper, we examine the functioning of the hugely successful New York City CitiBike system. We focus on the interaction of BSS with land-use and built environment attributes and the influence of weather condition and temporal characteristics on BSS usage. Towards this end, CitiBike system is analyzed along two dimensions: (1) at the system level, we examine the hourly station level arrival and departure rates using a linear mixed model and (2) at the trip level, we investigate users’ destination station choice preferences after they pick up a bicycle from a station employing a random utility maximization approach. The results highlight clear spatial and temporal differences in the usage of CitiBike by users with annual membership and users with temporary passes. Overall, our analysis provides a framework and useful insights for cities that are planning to install a new bicycle sharing system or to expand an existing syste

How Bicycling Sharing System Usage is Affected by Land Use and Urban Form: Analysis from System and User Perspectives

There is a rapid growth of bicycle-sharing systems (BSS) around the world. Cities are supporting these systems as a more sustainable transport mode for short trips. Given the relatively recent adoption of BSS, there is substantial interest in understanding how these systems impact urban transportation. In this paper, we examine the functioning of the hugely successful New York City CitiBike system. We focus on the interaction of BSS with land-use and built environment attributes and the influence of weather condition and temporal characteristics on BSS usage. Towards this end, CitiBike system is analyzed along two dimensions: (1) at the system level, we examine the hourly station level arrival and departure rates using a linear mixed model and (2) at the trip level, we investigate users\u27 destination station choice preferences after they pick up a bicycle from a station employing a random utility maximization approach. The results highlight clear spatial and temporal differences in the usage of CitiBike by users with annual membership and users with temporary passes. Overall, our analysis provides a framework and useful insights for cities that are planning to install a new bicycle sharing system or to expand an existing system

Synthesis and cytotoxic studies of a new series of pyridinoxymethylcoumarins

A series of 3-​(pyridin-​3-​yloxymethyl)​-​chromen-​2-​ones were synthesized by the reaction of substituted 4-​bromomethylcoumarins with 3-​hydroxypyridines. The synthesized compds. were screened for their cytotoxic activities against Dalton's ascitic lymphoma (DAL) and Ehrlich ascites carcinoma (EAC) cell lines. The 2-​(2-​Methyl-​pyridin-​3-​yloxymethyl)​-​benzo[f]​chromen-​3-​one was found to be the most cytotoxic against DAL cell line and 6-​Isopropyl-​3-​(2-​methyl-​pyridin-​3-​yloxymethyl)​-​chromen-​2-​one was found to be the most cytotoxic against EAC cell line

Synthesis and Biological Evaluation of 4-(3-Hydroxy-Benzofuran-2-yl) Coumarins

Various 4-bromomethylcoumarins (1a-k) were reacted with methyl salicylate to yield 2-(2-oxo-2H-chromen-4-ylmethoxy)-benzoic acid methyl esters (2a-k). Formations of (3a-k) were achieved by using DBU under microwave irradiation. Structures of all the compounds were established on the basis of their spectral data. All the compounds were tested in vitro for their antimicrobial activity and cell cytotoxicity. All the tested compounds (2b-k) and (3a-k) were shown to be better activity against Staphylococcus aureus than the standard Ciprofloxacin. The compound (3k) (R = 6-OMe) was found to be more potent cytotoxic than the standard 5-fluorouracil

Encouraging sustainable modal shift—An evaluation of the Portsmouth Big Green Commuter Challenge

This paper describes the impact of the Portsmouth “Big Green Commuter Challenge” (BGCC) event, organized by Portsmouth City Council (PCC) in order to reduce carbon and nitrogen oxide emissions from transport within the city. In total, over 1000 people and 36 organizations took part in the 2011 event. This is an example of a ‘Smarter Choice” measure designed to encourage travel behavioral change to more sustainable modes of transport. A literature review and evaluation of previous “Smarter Choices” measures has been carried out to give some context to the BGCC. An introduction to the city of Portsmouth is presented, in particular its efforts to reduce road traffic and emissions from the city centre area. The event encouraged a modal shift to more sustainable modes of travel, resulting in estimated reductions in CO2 and NOx emissions per mile. However, a number of further recommendations have been made to enable future similar events to have a greater impact on road traffic and emissions

How land-use and urban form impact bicycle flows: Evidence from the bicycle-sharing system (BIXI) in Montreal

ABSTRACT Installed in 2009, BIXI is the first major public bicycle-sharing system in Montreal, Canada. The BIXI system has been a success, accounting for more than one million trips annually. This success has increased the interest in exploring the factors affecting bicycle-sharing flows and usage. Using data compiled as minute-by-minute readings of bicycle availability at all the stations of the BIXI system between April and August 2012, this study contributes to the literature on bicycle-sharing. We examine the influence of meteorological data, temporal characteristics, bicycle infrastructure, land use and built environment attributes on arrival and departure flows at the station level using a multilevel approach to statistical modeling, which could easily be applied to other regions. The findings allow us to identify factors contributing to increased usage of bicycle-sharing in Montreal and to provide recommendations pertaining to station size and location decisions. The developed methodology and findings can be of benefit to city planners and engineers who are designing or modifying bicycle-sharing systems with the goal of maximizing usage and availability

Simultaneous equation penalized likelihood estimation of vehicle accident injury severity

A bivariate system of equations is developed to model ordinal polychotomous dependent variables within a simultaneous additive regression framework. The functional form of the covariate effects is assumed fairly flexible with appropriate smoothers used to account for non‐linearities and spatial variability in the data. Non‐Gaussian error dependence structures are dealt with by means of copulas whose association parameter is also specified in terms of a generic additive predictor. The framework is employed to study the effects of several risk factors on the levels of injury sustained by individuals in two‐vehicle accidents in France. The use of the methodology proposed is motivated by the presence of common unobservables that may affect the interrelationships between the parties involved in the same crash and by the possible heterogeneity in individuals’ characteristics and accident dynamics. Better calibrated estimates are obtained and misspecification reduced via an enhanced model specification