We consider two variational inequality formulations of the static traac equilibrium problem with xed demand. We determine when an arc-ow formulation can be considered to be equivalent to a path-ow formulation by analyzing the eeect of the form of the travel-time cost function on whether a ow between an origin-destination pair can use all arcs of a directed cycle. An important tool in the analys...

This vignette describes gdistance, an R package which provides functionality to calculate various distance measures and routes in heterogeneous geographic spaces represented as grids. Distances are fundamental to geospatial analysis (Tobler 1970). The most commonly used geographic distance measure is the great-circle distance, which represents the shortest line between two points, taking into a...

Introduction: The number of travellers from Greece who travel to sub-Saharan Africa has increased during the last decade. Our aim in this research was to study vaccination patterns for travellers travelling to sub-Saharan Africa.Methods: A cross-sectional study was conducted from January 2011 until December 2014 in all (57) public health departments in Gr...

Foragers must often travel from a central place to exploit aggregations of prey. These patches can be identified behaviorally when a forager shifts from travel to area restricted search, identified by a decrease in speed and an increase in sinuosity of movement. Faster, more directed movement is associated with travel. Differentiating foraging behavior at patches from travel to patches is impor...

In this study two actual types of problems are considered and solved: 1) determining the maximum common connected fragment of the T-tree (T-directed tree) which does not change with time; 2) determining all maximum common connected fragments of the T-tree (T-directed tree) which do not change with time. The choice of the primary study of temporal directed trees and trees is justified by the wid...

Introduction: There has been significant growth in international tourism from South-East Asia. Travel medicine services are still quite limited in this region. Few data exists on the knowledge, attitudes and practices of travelers from South-East Asia regarding the prevention of travel-related health risks. The present study aimed to characterize the travel t...

The study of future thinking is gaining momentum across various domains of psychology. Mentally projecting the self forward in time (i.e., mental time travel) is argued to be uniquely human and of vital importance to the evolution of human culture. Yet it is only recently that developmentalists have begun to study when, and how, this capacity emerges. I begin by outlining the concept of mental ...

Introduction: Emerging countries have increased their presence in international travel (46.8% of travels). Pre- and post-travel consultations may provide insights about travelers’ health. Methods: A retrospective descriptive analysis of the medical data of all travelers assisted at Ambulatório dos Viajantes, a free public health clinic for travelers in Sã...

This vignette describes gdistance, an R package which provides functionality to calculate various distance measures and routes in heterogeneous geographic spaces represented as grids. Distances are fundamental to geospatial analysis (Tobler 1970). The most commonly used geographic distance measure is the great-circle distance, which represents the shortest line between two points, taking into a...