Purely stochastic methods can yield useful prediction models of contaminant arrival-time distributions derived from advective-dispersive transport in a variety of one-dimensional environments. Two different models are considered, both relating to dispersion of a brief pulse of conservative contaminant in a steady flow system. The first model considers the arrival-time of a contaminant pulse in ...

In this paper we use the results of a recent on-site recreation survey to know whether it matters to use perceived rather than calculated travel costs. The calculated travel costs (time and money) are derived from detailed GIS computations. The perceived travel times and costs are taken directly from the survey responses. We first find that there is a high non-response rate for the perceived co...

Active travel to school has been referred to as one way of increasing the level of daily physical exercise, but the actual impacts on student's general health are not clear. Recently, a possible association between active travel to school and the duration of sleep was suggested. Thus, the aim was of this study to investigate the associations between the type of transportation and travel time to...

rapid urban growth is resulting into increase in travel demand and private vehicle ownership in urban areas. in the present scenario the existing infrastructure has failed to match the demand that leads to traffic congestion, vehicular pollution and accidents. with traffic congestion augmentation on the road, delay of commuters has increased and reliability of road network has decreased. four s...

Common reflection point (CRP) gathers are usually parameterized in terms of offset. For tomography, a more convenient parameterization is in terms of reflection angle. Reflection angle CRP gathers can be constructed using wave equation migration. By performing tomography in vertical travel-time (tau), focusing velocity, rather than some combination of focusing and mapping velocity, can be estim...

in this paper the factors having influence on travel demand to iran are paper explored. the hypothesis of the research specifies the variable of “domestic upheavals and insecurity” as the most significant obstacle to expansion of the demand for travel to iran. to test the above hypothesis, first several demand models that have been proposed to study demand for tourism in different countries, ar...

This article argues that investigating the conceptual structure underlying the use of the pluperfect and the future perfect reveals a new complex type of nested dual mental time travel: mental time travel into posteriority embedded into mental time travel into “anteriority in the past” (underlying the pluperfect) versus mental time travel into posteriority embedded into mental time travel into ...

The collapse of geographical space over the last 200 years has had profound effects on the circulation of human populations and on the transfer of infectious diseases. Three examples are used to illustrate the process: (a) the impact of the switch from sail to steamships in importing measles into Fiji over a 40-year period; (b) changes in measles epidemic behaviour in Iceland over a 150-year pe...