Gender inequality in mobility and mode choice in Pakistan

Using the nationally representative dataset of the 2007 Pakistan Time-Use Survey, this paper examines gender differences in daily trip rate, mode choice, travel duration, and purpose of travel, which are previously unreported because of limited data availability. Wide gender mobility gaps are observed in the country, where women are less likely to travel, are half as mobile as men and may rely heavily on walking. The particular social and cultural context of the country, that renders women as private, secluded and family honor, seems influential in shaping their mobility and choice of activities. Demographic factors such as age, household income, and marital status significantly decrease female mobility levels. Hence, these findings call for a gender-based culturally responsive transportation policy in the country.     

Efficiency measurement in public transport: Are findings specification sensitive?

The need to measure transit system performance along with its various dimensions such as efficiency and effectiveness has led to the development of a wide array of approaches and vast literature. However, depending upon the specific approach used to examine performance, different conclusions are oftentimes reached. Using data from 15 European transit systems for a ten year time period (1990-2000), this paper discusses three important transit performance questions; (i) Do different efficiency assessment methodologies produce similar results? (ii) How are the two basic dimensions of transit performance, namely efficiency and effectiveness, related? and (iii) Are findings regarding organizational regimes (public operations, contracting and so on) sensitive to the methodological specifications employed? Results clearly indicate that efficiency scores and associated recommendations are sensitive to the models used, while efficiency and effectiveness are - albeit weakly - negatively related; these two findings can have far reaching policy implications.     

Acceptability of audible pedestrian signal noise

This paper considers the impact on local residents of audible pedestrian signals (APS) that provide cues to the visually handicapped pedestrians on the onset of the various signal phases at a signalized crosswalk. We investigate the extent of the noise intrusion problem of APS through understanding the acceptability by the general public. From the perception surveys conducted, vehicle engine/braking sound, neighbor talking/playing and vehicle alarm are the top three irritating noises experienced while sleeping whereas audible signals is ranked at 21st position. The maximum sound level of the signals found to be acceptable indoors is close to 60 dBA.     

A model to identify airport hubs and their importance to tourism in Brazil

Air transportation in Brazil has been recently liberalized and one of the consequences of this process is the concentration of flights in a few hubs. During the years 2006-2007 two fatal accidents created unprecedented chaos in both land and air sides of the system with harmful consequences to tourism in Brazil. The consequences were more airport congestion and many episodes of flight delays and cancellations that lasted for several months. We argue that, among other factors, this state of blackout was a result of the increase in the degree of concentration in few airports, particularly Congonhas (in São Paulo) and Brasília. Using data obtained from a survey with Brazilian experts, a comparison was made with two existing methods (the one used by the US Federal Aviation Administration and the usual Herfindahl-Hirschman method) in order to calculate the number of hubs in Brazil. Due to the huge discrepancy obtained between data from the survey and the other two methods considered, a new mathematical method based on the Herfindahl-Hirschman Index was proposed to identify the number of hubs in a given network. Drawing from the examples of what happened to tourist destinations during and after the air transport crisis in Brazil, the article concludes discussing the need for a more accurate tool to identify and to monitor the concentration of flights at the Brazilian air transportation network and its importance to tourism.     

A porous cell method for the simulation of fluid-solid interactions

There are many ways of describing a solid,porous or fluid region of the computational domain when solving the Navier-Stokes equations(NSE)for flow motions.Amongst these the porous cell method is one of the most flexible approaches.In this method,a parameter is defined as a ratio of the volume open to water and air in a calculation cell to its cell volume.In the calculation,the same numerical procedure is applied to every cell and no explicit boundary conditions are needed at solid boundaries.The method is used to simulate flow through porous media,around solid bodies and over a moving seabed.The results compare well with experimental data and other numerical results.In our future work the porous cell method will be applied to more complex fluid-solid interaction situations.     

Computer Aided Simulation on Precision Cold Forging of Universal Joint Cross

IntroductionThefiwtee1emenmethod(FEM)playsanextrmelyimPortantroleintheanalysesofengineeringproblems.ForalongtimethismethodhasmainlybeenaPPliedinthelinearfieldandshownitsgreatpower.HoweveealOtofnonlinearengineeringPrOblemsWhichcanneitherbesimPlyreducedtolinearonesnorrCPresentedbylinearlyanalogywhichshallchnsethePfacticalconditionsrelativelymuch,havechallengedfiniteelementmethod(FEM).RecentymuchProgresshasbeenmadebothinthemathematicalandmechanicaltheoryandthecomPulertechnologysothatevent…     

Dynamic Stability of Vehicle Systems via Poincaré Maps

Computer simulations of a driven vehicle are performed to assess and quantify the automobile stability. The analytical methodology is based on PoincarS maps and Floquet theory, which are commonly used to investigate the stability of periodic systems. The approach accommodates the study of the complex dynamics of vehicle locomotion under various configurations of the system. The proposed method does not require any knowledge regarding the inner structure of the vehicle model. Kinematic data is simply collected at the specific instants to conduct the analysis. It is found that this method has the potential for real time warning and control of vehicle instabilities.     

The Calculation of the Vibrations of a Four-wheeled Vehicle, Induced by Random Road Roughness of the Left and Right Track

When applying the known power spectra of the random road roughness to the suspension behaviour of a four-wheeled vehicle, each of the four vertical input signals together with their related interdependence are to be considered, if exact results are to be obtained. The correlations are determined by way of calculation. The resulting roughness spectra of bounce, pitch, roll and torsional excitations will be applied to various vehicles, characterized by different design parameters. By means of a three-dimensional simulation model the virtual values of the random vehicle vibrations are calculated, while determining at the same time the influence of vehicle speed, waviness exponent, track width, wheel base, and axle design feature as well as the relationship between the vertical vibrations and the reference point in the vehicle body.     

A disaggregated land use—transport model for Delhi,India

A Lowry-type land use-transport model stratified both by socio-economic group and urban sub-region is described. The parameters of this model are calibrated from a 1969 urban travel survey conducted in Delhi. Parameter magnitudes are estimated for several versions of the model and the qualities of these calibrations are reported. Applications of the calibrated models to the analysis of alternative development concepts for the Delhi urban region are described.     

US shipping policy under conditions of a new world economic and political environment

The maritime policy of the US has evolved over more than 100 years from the support of US shipping through mail and fleet auxiliary contracts before the turn of the century, to the present array of direct and indirect Government aids and regulations based on the assumption that a strong maritime industry composed of both US-flag shipping and US-shipbuilding capacity is essential for the economic well-being and defence of the country. Notwithstanding massive direct and indirect aid to the US merchant marine, amounting to well over a billion dollars a year in recent years, US shipping and shipbuilding has declined dramatically and now comprises less than 3% of world shipping. Only 2.8% of US foreign trade by volume and 6% by value is today carried in US flag ships. Government aids constitute well over 33% of total revenues of US-flag shipping.

The traditional argument for US Government support has been the need for cost parity to permit US-flag shipping to compete effectively in international trade against foreign shipping serving the same routes with presumably lower operating costs. This argument is difficult to sustain today, as vessel costs of many other industrialized nations are now about equal to those of US-flag ships.

In 1970 the US enacted a new, vastly more liberal, maritime act for the support of the US maritime industry. Notwithstanding its even more liberal terms and elimination of the strict cost-parity interpretation, the US maritime industry continues its decline. The recent bankruptcy of two old, established subsidized shipping companies has caused tremors in the industry, yet no new ideas, policies, or plans seem to be forthcoming. It is the objective of this paper to study the development and effects of various historic US Government policies relating to the support of the US maritime industry, and evaluate the positions taken by proponents or opponents of the maritime policy leading to the policy development.

The decision processes are studied by evaluating literature on the evolution of Congressional, administration, industry, and labour interest and positions on the issue of Government aid to the maritime industry. The impact and effectiveness of various elements of past and present US maritime policy is evaluated in relation to the stated objectives. The alternatives to these policies are reviewed in the light of the changing US position in international trade, military strategy, and political objectives. In addition the effectiveness of the present and alternative policies is evaluated as it is and will be affected by changing technology in use, composition of ownership, and operations of US-flag shipping and shipbuilding.