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Sample records for double traveling salesman

  1. The double travelling salesman problem with multiple stacks - Formulation and heuristic solution approaches

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann; Madsen, Oli B.G.

    2009-01-01

    This paper introduces the double travelling salesman problem with multiple stacks and presents four different metaheuristic approaches to its solution. The double TSP with multiple stacks is concerned with determining the shortest route performing pickups and deliveries in two separated networks...

  2. Exact Solutions to the Double Travelling Salesman Problem with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne L.; Archetti, Claudia; Speranza, M. Grazia

    2010-01-01

    In this paper we present mathematical programming formulations and solution approaches for the optimal solution of the Double Travelling Salesman Problem with Multiple Stacks (DTSPMS). A set of orders is given, each one requiring transportation of one item from a customer in a pickup region...

  3. Double evolutsional artificial bee colony algorithm for multiple traveling salesman problem

    Directory of Open Access Journals (Sweden)

    Xue Ming Hao

    2016-01-01

    Full Text Available The double evolutional artificial bee colony algorithm (DEABC is proposed for solving the single depot multiple traveling salesman problem (MTSP. The proposed DEABC algorithm, which takes advantage of the strength of the upgraded operators, is characterized by its guidance in exploitation search and diversity in exploration search. The double evolutional process for exploitation search is composed of two phases of half stochastic optimal search, and the diversity generating operator for exploration search is used for solutions which cannot be improved after limited times. The computational results demonstrated the superiority of our algorithm over previous state-of-the-art methods.

  4. Large neighborhood search for the double traveling salesman problem with multiple stacks

    Energy Technology Data Exchange (ETDEWEB)

    Bent, Russell W [Los Alamos National Laboratory; Van Hentenryck, Pascal [BROWN UNIV

    2009-01-01

    This paper considers a complex real-life short-haul/long haul pickup and delivery application. The problem can be modeled as double traveling salesman problem (TSP) in which the pickups and the deliveries happen in the first and second TSPs respectively. Moreover, the application features multiple stacks in which the items must be stored and the pickups and deliveries must take place in reserve (LIFO) order for each stack. The goal is to minimize the total travel time satisfying these constraints. This paper presents a large neighborhood search (LNS) algorithm which improves the best-known results on 65% of the available instances and is always within 2% of the best-known solutions.

  5. On Labeled Traveling Salesman Problems

    DEFF Research Database (Denmark)

    Couetoux, Basile; Gourves, Laurent; Monnot, Jerome

    2008-01-01

    We consider labeled Traveling Salesman Problems, defined upon a complete graph of n vertices with colored edges. The objective is to find a tour of maximum (or minimum) number of colors. We derive results regarding hardness of approximation, and analyze approximation algorithms for both versions ...

  6. Traveling Salesman Problem with Transportation

    Directory of Open Access Journals (Sweden)

    Valeriu Ungureanu

    2006-09-01

    Full Text Available Traveling Salesman Problem (TSP is a generic name that includes diverse practical models. Motivated by applications, a new model of TSP is examined – a synthesis of classical TSP and classical Transportation Problem. Algorithms based on Integer Programming cutting-plane methods and Branch and Bound Techniques are obvious.

  7. Analysis of travelling salesman problem

    Science.gov (United States)

    Ahmed, Belal; Singh Chouhan, Shivank; Biswas, Subham; Gayathri, P.; Santhi, H.

    2017-11-01

    The multiple Traveling Salesman Problem (mTSP) is the general type of TSP, in which at least one than one sales representatives can be utilized as a part of the arrangement set. The Constraint in the improvement undertaking is that every sales representative comes back to beginning stage at end of outing, heading out to a particular arrangement of urban areas in the middle of and with the exception of the first, every last city is gone to by precisely one sales representative. The thought is to scan for the briefest course that is the slightest separation required for every salesperson to go from the beginning area to individual urban areas and back to the area from where he has begun. It is an intricate NP-Hard issue and has different applications for the most part in the field of planning and steering. The measure of algorithm time to take care of this issue develops exponentially as number of urban areas builds thus, the meta-heuristic streamlining algorithms, for example, Genetic Algorithm (GAs) are should have been investigated. The objective of this paper is to discover different algorithms utilized as a part of writing to understand mTSP.

  8. Boltzmann machines for travelling salesman problems

    NARCIS (Netherlands)

    Aarts, E.H.L.; Korst, J.H.M.

    1989-01-01

    Boltzmann machines are proposed as a massively parallel alternative to the (sequential) simulated annealing algorithm. Our approach is tailored to the travelling salesman problem, but it can also be applied to a more general class of combinatorial optimization problems. For two distinct 0–1

  9. The Quadratic Selective Travelling Salesman Problem

    DEFF Research Database (Denmark)

    Thomadsen, Tommy; Stidsen, Thomas K.

    2003-01-01

    A well-known extension of the Travelling Salesman Problem (TSP) is the Selective TSP (STSP): Each node has an associated profit and instead of visiting all nodes, the most profitable set of nodes, taking into account the tour cost, is visited. The Quadratic STSP (QSTSP) adds the additional...

  10. Trajectory Stability in the Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Sergio Sánchez

    2018-01-01

    Full Text Available Two generalizations of the traveling salesman problem in which sites change their position in time are presented. The way the rank of different trajectory lengths changes in time is studied using the rank diversity. We analyze the statistical properties of rank distributions and rank dynamics and give evidence that the shortest and longest trajectories are more predictable and robust to change, that is, more stable.

  11. The traveling salesman problem a computational study

    CERN Document Server

    Applegate, David L; Chvatal, Vasek; Cook, William J

    2006-01-01

    This book presents the latest findings on one of the most intensely investigated subjects in computational mathematics--the traveling salesman problem. It sounds simple enough: given a set of cities and the cost of travel between each pair of them, the problem challenges you to find the cheapest route by which to visit all the cities and return home to where you began. Though seemingly modest, this exercise has inspired studies by mathematicians, chemists, and physicists. Teachers use it in the classroom. It has practical applications in genetics, telecommunications, and neuroscience.

  12. FACES WITH LARGE DIAMETER ON THE SYMMETRICAL TRAVELING SALESMAN POLYTOPE

    NARCIS (Netherlands)

    SIERKSMA, G; TIJSSEN, GA

    This paper deals with the symmetric traveling salesman polytope and contains three main theorems. The first one gives a new characterization of (non)adjacency. Based on this characterization a new upper bound for the diameter of the symmetric traveling salesman polytope (conjectured to be 2 by M.

  13. The on-line asymmetric traveling salesman problem

    NARCIS (Netherlands)

    Ausiello, G.; Bonifaci, V.; Laura, L.

    2008-01-01

    We consider two on-line versions of the asymmetric traveling salesman problem with triangle inequality. For the homing version, in which the salesman is required to return in the city where it started from, we give a -competitive algorithm and prove that this is best possible. For the nomadic

  14. On the Core of Multiple Longest Traveling Salesman Games

    NARCIS (Netherlands)

    Estevez Fernandez, M.A.; Borm, P.E.M.; Hamers, H.J.M.

    2003-01-01

    In this paper we introduce multiple longest traveling salesman (MLTS) games. An MLTS game arises from a network in which a salesman has to visit each node (player) precisely once, except its home location, in an order that maximizes the total reward.First it is shown that the value of a coalition of

  15. The cost-constrained traveling salesman problem

    Energy Technology Data Exchange (ETDEWEB)

    Sokkappa, P.R.

    1990-10-01

    The Cost-Constrained Traveling Salesman Problem (CCTSP) is a variant of the well-known Traveling Salesman Problem (TSP). In the TSP, the goal is to find a tour of a given set of cities such that the total cost of the tour is minimized. In the CCTSP, each city is given a value, and a fixed cost-constraint is specified. The objective is to find a subtour of the cities that achieves maximum value without exceeding the cost-constraint. Thus, unlike the TSP, the CCTSP requires both selection and sequencing. As a consequence, most results for the TSP cannot be extended to the CCTSP. We show that the CCTSP is NP-hard and that no K-approximation algorithm or fully polynomial approximation scheme exists, unless P = NP. We also show that several special cases are polynomially solvable. Algorithms for the CCTSP, which outperform previous methods, are developed in three areas: upper bounding methods, exact algorithms, and heuristics. We found that a bounding strategy based on the knapsack problem performs better, both in speed and in the quality of the bounds, than methods based on the assignment problem. Likewise, we found that a branch-and-bound approach using the knapsack bound was superior to a method based on a common branch-and-bound method for the TSP. In our study of heuristic algorithms, we found that, when selecting modes for inclusion in the subtour, it is important to consider the neighborhood'' of the nodes. A node with low value that brings the subtour near many other nodes may be more desirable than an isolated node of high value. We found two types of repetition to be desirable: repetitions based on randomization in the subtour buildings process, and repetitions encouraging the inclusion of different subsets of the nodes. By varying the number and type of repetitions, we can adjust the computation time required by our method to obtain algorithms that outperform previous methods.

  16. Spatial Transformation of Equality – Generalized Travelling Salesman Problem to Travelling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Mohammed Zia

    2018-03-01

    Full Text Available The Equality-Generalized Travelling Salesman Problem (E-GTSP, which is an extension of the Travelling Salesman Problem (TSP, is stated as follows: given groups of points within a city, like banks, supermarkets, etc., find a minimum cost Hamiltonian cycle that visits each group exactly once. It can model many real-life combinatorial optimization scenarios more efficiently than TSP. This study presents five spatially driven search-algorithms for possible transformation of E-GTSP to TSP by considering the spatial spread of points in a given urban city. Presented algorithms are tested over 15 different cities, classified by their street-network’s fractal-dimension. Obtained results denote that the R-Search algorithm, which selects the points from each group based on their radial separation with respect to the start–end point, is the best search criterion for any E-GTSP to TSP conversion modelled for a city street network. An 8.8% length error has been reported for this algorithm.

  17. Solving Dynamic Traveling Salesman Problem Using Dynamic Gaussian Process Regression

    Directory of Open Access Journals (Sweden)

    Stephen M. Akandwanaho

    2014-01-01

    Full Text Available This paper solves the dynamic traveling salesman problem (DTSP using dynamic Gaussian Process Regression (DGPR method. The problem of varying correlation tour is alleviated by the nonstationary covariance function interleaved with DGPR to generate a predictive distribution for DTSP tour. This approach is conjoined with Nearest Neighbor (NN method and the iterated local search to track dynamic optima. Experimental results were obtained on DTSP instances. The comparisons were performed with Genetic Algorithm and Simulated Annealing. The proposed approach demonstrates superiority in finding good traveling salesman problem (TSP tour and less computational time in nonstationary conditions.

  18. A NEW HEURISTIC ALGORITHM FOR MULTIPLE TRAVELING SALESMAN PROBLEM

    Directory of Open Access Journals (Sweden)

    F. NURIYEVA

    2017-06-01

    Full Text Available The Multiple Traveling Salesman Problem (mTSP is a combinatorial optimization problem in NP-hard class. The mTSP aims to acquire the minimum cost for traveling a given set of cities by assigning each of them to a different salesman in order to create m number of tours. This paper presents a new heuristic algorithm based on the shortest path algorithm to find a solution for the mTSP. The proposed method has been programmed in C language and its performance analysis has been carried out on the library instances. The computational results show the efficiency of this method.

  19. Algorithms for the on-line travelling salesman

    NARCIS (Netherlands)

    Ausiello, G.; Feuerstein, E.; Leonardi, S.; Stougie, L.; Talamo, M.

    1999-01-01

    In this paper the problem of efficiently serving a sequence of requests presented in an on-line fashion located at points of a metric space is considered. We call this problem the On-Line Travelling Salesman Problem (OLTSP). It has a variety of relevant applications in logistics and robotics. We

  20. The traveling salesman problem with few inner points

    NARCIS (Netherlands)

    Deineko, V.G.; Hoffmann, M.; Okamoto, Y.; Woeginger, G.J.; Chwa, K.Y.; Munro, J.I.

    2004-01-01

    We study the traveling salesman problem (TSP) in the 2-dimensional Euclidean plane. The problem is NP-hard in general, but trivial if the points are in convex position. In this paper, we investigate the influence of the number of inner points (i.e., points in the interior of the convex hull) on the

  1. Optimization of Gas Flow Network using the Traveling Salesman ...

    African Journals Online (AJOL)

    The overall goal of this paper is to develop a general formulation for an optimal infrastructure layout design of gas pipeline distribution networks using algorithm developed from the application of two industrial engineering concepts: the traveling salesman problem (TSP) and the nearest neighbor (NN). The focus is on the ...

  2. Dynamic Programming Approaches for the Traveling Salesman Problem with Drone

    NARCIS (Netherlands)

    P. Bouman (Paul); N.A.H. Agatz (Niels); M.E. Schmidt (Marie)

    2017-01-01

    markdownabstractA promising new delivery model involves the use of a delivery truck that collaborates with a drone to make deliveries. Effectively combining a drone and a truck gives rise to a new planning problem that is known as the Traveling Salesman Problem with Drone (TSP-D). This paper

  3. Development of the PEBLebl Traveling Salesman Problem Computerized Testbed

    Science.gov (United States)

    Mueller, Shane T.; Perelman, Brandon S.; Tan, Yin Yin; Thanasuan, Kejkaew

    2015-01-01

    The traveling salesman problem (TSP) is a combinatorial optimization problem that requires finding the shortest path through a set of points ("cities") that returns to the starting point. Because humans provide heuristic near-optimal solutions to Euclidean versions of the problem, it has sometimes been used to investigate human visual…

  4. Fluctuations in the site-disordered traveling salesman problem

    Energy Technology Data Exchange (ETDEWEB)

    Dean, David S [Laboratoire de Physique Theorique, UMR CNRS 5152, IRSAMC, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex 04 (France); Lancaster, David [Harrow School of Computer Science, University of Westminster, Harrow HA1 3TP (United Kingdom)

    2007-11-16

    We extend a previous statistical mechanical treatment of the traveling salesman problem by defining a discrete 'site-disordered' problem in which fluctuations about saddle points can be computed. The results clarify the basis of our original treatment, and illuminate but do not resolve the difficulties of taking the zero-temperature limit to obtain minimal path lengths.

  5. The Electric Traveling Salesman Problem with Time Windows

    DEFF Research Database (Denmark)

    Roberti, Roberto; Wen, Min

    2016-01-01

    To minimize greenhouse gas emissions, the logistic field has seen an increasing usage of electric vehicles. The resulting distribution planning problems present new computational challenges.We address a problem, called Electric Traveling Salesman Problem with Time Windows. We propose a mixed...

  6. A parallel 2-opt algorithm for the traveling salesman problem

    NARCIS (Netherlands)

    Verhoeven, M.G.A.; Aarts, E.H.L.; Swinkels, P.C.J.

    1995-01-01

    We present a scalable parallel local search algorithm based on data parallelism. The concept of distributed neighborhood structures is introduced, and applied to the Traveling Salesman Problem (TSP). Our parallel local search algorithm finds the same quality solutions as the classical 2-opt

  7. Dynamic Programming Approaches for the Traveling Salesman Problem with Drone

    NARCIS (Netherlands)

    P. Bouman (Paul); N.A.H. Agatz (Niels); M.E. Schmidt (Marie)

    2017-01-01

    markdownabstractA promising new delivery model involves the use of a delivery truck that collaborates with a drone to make deliveries. Effectively combining a truck and a drone gives rise to a new planning problem that is known as the Traveling Salesman Problem with Drone (TSP-D). This paper

  8. A HYBRID HEURISTIC ALGORITHM FOR THE CLUSTERED TRAVELING SALESMAN PROBLEM

    Directory of Open Access Journals (Sweden)

    Mário Mestria

    2016-04-01

    Full Text Available ABSTRACT This paper proposes a hybrid heuristic algorithm, based on the metaheuristics Greedy Randomized Adaptive Search Procedure, Iterated Local Search and Variable Neighborhood Descent, to solve the Clustered Traveling Salesman Problem (CTSP. Hybrid Heuristic algorithm uses several variable neighborhood structures combining the intensification (using local search operators and diversification (constructive heuristic and perturbation routine. In the CTSP, the vertices are partitioned into clusters and all vertices of each cluster have to be visited contiguously. The CTSP is -hard since it includes the well-known Traveling Salesman Problem (TSP as a special case. Our hybrid heuristic is compared with three heuristics from the literature and an exact method. Computational experiments are reported for different classes of instances. Experimental results show that the proposed hybrid heuristic obtains competitive results within reasonable computational time.

  9. THE DUBINS TRAVELING SALESMAN PROBLEM WITH CONSTRAINED COLLECTING MANEUVERS

    Directory of Open Access Journals (Sweden)

    Petr Váňa

    2016-11-01

    Full Text Available In this paper, we introduce a variant of the Dubins traveling salesman problem (DTSP that is called the Dubins traveling salesman problem with constrained collecting maneuvers (DTSP-CM. In contrast to the ordinary formulation of the DTSP, in the proposed DTSP-CM, the vehicle is requested to visit each target by specified collecting maneuver to accomplish the mission. The proposed problem formulation is motivated by scenarios with unmanned aerial vehicles where particular maneuvers are necessary for accomplishing the mission, such as object dropping or data collection with sensor sensitive to changes in vehicle heading. We consider existing methods for the DTSP and propose its modifications to use these methods to address a variant of the introduced DTSP-CM, where the collecting maneuvers are constrained to straight line segments.

  10. 2D and 3D Traveling Salesman Problem

    Science.gov (United States)

    Haxhimusa, Yll; Carpenter, Edward; Catrambone, Joseph; Foldes, David; Stefanov, Emil; Arns, Laura; Pizlo, Zygmunt

    2011-01-01

    When a two-dimensional (2D) traveling salesman problem (TSP) is presented on a computer screen, human subjects can produce near-optimal tours in linear time. In this study we tested human performance on a real and virtual floor, as well as in a three-dimensional (3D) virtual space. Human performance on the real floor is as good as that on a…

  11. THE TRAVELLING SALESMAN PROBLEM IN THE ENGINEERING EDUCATION PROGRAMMING CURRICULUM

    OpenAIRE

    Yevgeny Gayev; Vadim Kalmikov

    2017-01-01

    Objective: To make students familiar with the famous Traveling Salesman Problem (TSP) and suggest the latter to become a common exercise in engineering programming curriculum provided the students master computer science in the easy programming environment MATLAB. Methods: easy programming in MATLAB makes true such modern educational approach as “discovery based” methodology. Results: a MATLAB TSP-program oriented to Ukrainian map is suggested that allows to pictorially demonstrate the proces...

  12. Dynamic Programming Approaches for the Traveling Salesman Problem with Drone

    OpenAIRE

    Bouman, Paul; Agatz, Niels; Schmidt, Marie

    2017-01-01

    markdownabstractA promising new delivery model involves the use of a delivery truck that collaborates with a drone to make deliveries. Effectively combining a drone and a truck gives rise to a new planning problem that is known as the Traveling Salesman Problem with Drone (TSP-D). This paper presents an exact solution approach for the TSP-D based on dynamic programming and present experimental results of different dynamic programming based heuristics. Our numerical experiments show that our a...

  13. Polyhedral combinatorics of the cardinality constrained quadratic knapsack problem and the quadratic selective travelling salesman problem

    DEFF Research Database (Denmark)

    Mak, Vicky; Thomadsen, Tommy

    2006-01-01

    This paper considers the cardinality constrained quadratic knapsack problem (QKP) and the quadratic selective travelling salesman problem (QSTSP). The QKP is a generalization of the knapsack problem and the QSTSP is a generalization of the travelling salesman problem. Thus, both problems are NP...

  14. A comparison of lower bounds for the symmetric circulant traveling salesman problem

    NARCIS (Netherlands)

    de Klerk, E.; Dobre, C.

    2011-01-01

    When the matrix of distances between cities is symmetric and circulant, the traveling salesman problem (TSP) reduces to the so-called symmetric circulant traveling salesman problem (SCTSP), that has applications in the design of reconfigurable networks, and in minimizing wallpaper waste. The

  15. Quantum elastic net and the traveling salesman problem

    International Nuclear Information System (INIS)

    Kostenko, B.F.; Pribis, J.; Yur'ev, M.Z.

    2009-01-01

    Theory of computer calculations strongly depends on the nature of elements the computer is made of. Quantum interference allows one to formulate the Shor factorization algorithm turned out to be more effective than any one written for classical computers. Similarly, quantum wave packet reduction allows one to devise the Grover search algorithm which outperforms any classical one. In the present paper we argue that the quantum incoherent tunneling can be used for elaboration of new algorithms able to solve some NP-hard problems, such as the traveling Salesman Problem, considered to be intractable in the classical theory of computer computations

  16. Optimization Approaches for the Traveling Salesman Problem with Drone

    OpenAIRE

    Agatz, N.A.H.; Bouman, P.C.; Schmidt, M.E.

    2016-01-01

    textabstractThe fast and cost-efficient home delivery of goods ordered online is logistically challenging. Many companies are looking for new ways to cross the last-mile to their customers. One technology-enabled opportunity that recently has received much at- tention is the use of a drone to support deliveries. An innovative last-mile delivery concept in which a truck collaborates with a drone to make deliveries gives rise to a new variant of the traveling salesman problem (TSP) that we call...

  17. Branch-and-cut-and-price for the traveling salesman problem with time windows

    DEFF Research Database (Denmark)

    Røpke, Stefan; Madsen, Oli B.G.

    In the traveling salesman problem with time windows (TSPTW) one is given a depot and a set of nodes to be visited by a salesman. The salesman starts his trip at the depot and must visit all nodes while respecting time windows at the nodes. The objective of the problem is to minimize the total...... distance traveled by the salesman. The TSPTW is formulated as a set-partitioning problem which is solved by using combined cut and column generation. The pricing sub problem in the column generation procedure is a shortest path problem with time window constraints and 2-cycle elimination. A standard column...

  18. Bi-criteria travelling salesman subtour problem with time threshold

    Science.gov (United States)

    Kumar Thenepalle, Jayanth; Singamsetty, Purusotham

    2018-03-01

    This paper deals with the bi-criteria travelling salesman subtour problem with time threshold (BTSSP-T), which comes from the family of the travelling salesman problem (TSP) and is NP-hard in the strong sense. The problem arises in several application domains, mainly in routing and scheduling contexts. Here, the model focuses on two criteria: total travel distance and gains attained. The BTSSP-T aims to determine a subtour that starts and ends at the same city and visits a subset of cities at a minimum travel distance with maximum gains, such that the time spent on the tour does not exceed the predefined time threshold. A zero-one integer-programming problem is adopted to formulate this model with all practical constraints, and it includes a finite set of feasible solutions (one for each tour). Two algorithms, namely, the Lexi-Search Algorithm (LSA) and the Tabu Search (TS) algorithm have been developed to solve the BTSSP-T problem. The proposed LSA implicitly enumerates the feasible patterns and provides an efficient solution with backtracking, whereas the TS, which is metaheuristic, will give the better approximate solution. A numerical example is demonstrated in order to understand the search mechanism of the LSA. Numerical experiments are carried out in the MATLAB environment, on the different benchmark instances available in the TSPLIB domain as well as on randomly generated test instances. The experimental results show that the proposed LSA works better than the TS algorithm in terms of solution quality and, computationally, both LSA and TS are competitive.

  19. Using 2-Opt based evolution strategy for travelling salesman problem

    Directory of Open Access Journals (Sweden)

    Kenan Karagul

    2016-03-01

    Full Text Available Harmony search algorithm that matches the (µ+1 evolution strategy, is a heuristic method simulated by the process of music improvisation. In this paper, a harmony search algorithm is directly used for the travelling salesman problem. Instead of conventional selection operators such as roulette wheel, the transformation of real number values of harmony search algorithm to order index of vertex representation and improvement of solutions are obtained by using the 2-Opt local search algorithm. Then, the obtained algorithm is tested on two different parameter groups of TSPLIB. The proposed method is compared with classical 2-Opt which randomly started at each step and best known solutions of test instances from TSPLIB. It is seen that the proposed algorithm offers valuable solutions.

  20. In Pursuit of the Traveling Salesman Mathematics at the Limits of Computation

    CERN Document Server

    Cook, William J

    2011-01-01

    What is the shortest possible route for a traveling salesman seeking to visit each city on a list exactly once and return to his city of origin? It sounds simple enough, yet the traveling salesman problem is one of the most intensely studied puzzles in applied mathematics--and it has defied solution to this day. In this book, William Cook takes readers on a mathematical excursion, picking up the salesman's trail in the 1800s when Irish mathematician W. R. Hamilton first defined the problem, and venturing to the furthest limits of today's state-of-the-art attempts to solve it. Cook examines

  1. An Enhanced Genetic Algorithm for the Generalized Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    H. Jafarzadeh

    2017-12-01

    Full Text Available The generalized traveling salesman problem (GTSP deals with finding the minimum-cost tour in a clustered set of cities. In this problem, the traveler is interested in finding the best path that goes through all clusters. As this problem is NP-hard, implementing a metaheuristic algorithm to solve the large scale problems is inevitable. The performance of these algorithms can be intensively promoted by other heuristic algorithms. In this study, a search method is developed that improves the quality of the solutions and competition time considerably in comparison with Genetic Algorithm. In the proposed algorithm, the genetic algorithms with the Nearest Neighbor Search (NNS are combined and a heuristic mutation operator is applied. According to the experimental results on a set of standard test problems with symmetric distances, the proposed algorithm finds the best solutions in most cases with the least computational time. The proposed algorithm is highly competitive with the published until now algorithms in both solution quality and running time.

  2. 20 CFR 404.1008 - Agent-driver or commission-driver, full-time life insurance salesman, home worker, or traveling...

    Science.gov (United States)

    2010-04-01

    ... commission-driver, full-time life insurance salesman, home worker, or traveling or city salesman. (a) General... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Agent-driver or commission-driver, full-time life insurance salesman, home worker, or traveling or city salesman. 404.1008 Section 404.1008...

  3. Perancangan Aplikasi Penjadwalan Traveling Salesman Problem dengan Algoritma Genetika

    Directory of Open Access Journals (Sweden)

    Hendy Tannady

    2012-12-01

    Full Text Available Supply chain management plays an important role in enhancing the efficiency and effectiveness of manufacturing industry business process. In this research, the problem is taken from a sales division in a company in determining the optimal sequence when delivering goods into nine cities. This problem is oftenreferred as travelling salesman problem. This problem is considered important since the optimal sequence can cut off operational cost. Creating an artificial intelligence for the company in determining the location and the optimal sequence of delivering goods is the main objective of this research. A genetic algorithm is utilized to determine the location and the optimal sequence. While for processing the data and concluding the result, researcher designed a Java-based application that provides the capability of automatic computing. The result of this computation is a sequence of locations with a fitness number for each. The best fitness number for the sequence location will be used for the final result and the conclusion to answer the company’s problem.

  4. THE TRAVELLING SALESMAN PROBLEM IN THE ENGINEERING EDUCATION PROGRAMMING CURRICULUM

    Directory of Open Access Journals (Sweden)

    Yevgeny Gayev

    2017-11-01

    Full Text Available Objective: To make students familiar with the famous Traveling Salesman Problem (TSP and suggest the latter to become a common exercise in engineering programming curriculum provided the students master computer science in the easy programming environment MATLAB. Methods: easy programming in MATLAB makes true such modern educational approach as “discovery based” methodology. Results: a MATLAB TSP-program oriented to Ukrainian map is suggested that allows to pictorially demonstrate the process of optimal route search with an option to decelerate or accelerate the demonstration. The program is guessed to be useful both for learning the TSP as one of fundamental logistics problems and as an intriguing programming curriculum excersize. Several sub-programs according to key stone Computer Science Curriculum have also been suggested. This lies in line with recent “discovery based” learning methodology. Discussion: we explain how to create this program for visual discrete optimization, suggest required subprograms belonging to key stone programming algorithms including rather modern graphical user interface (GUI, how to use this MATLAB TSP-program for demonstration the drastical grows of solution time required. Conclusions: easy programming being realized in MATLAB makes dificult curriculum problems attractive to students; it focuses them to main problem’ features, laws and algorithms implementing the “discovery based” methodology in such a way.

  5. List-Based Simulated Annealing Algorithm for Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Shi-hua Zhan

    2016-01-01

    Full Text Available Simulated annealing (SA algorithm is a popular intelligent optimization algorithm which has been successfully applied in many fields. Parameters’ setting is a key factor for its performance, but it is also a tedious work. To simplify parameters setting, we present a list-based simulated annealing (LBSA algorithm to solve traveling salesman problem (TSP. LBSA algorithm uses a novel list-based cooling schedule to control the decrease of temperature. Specifically, a list of temperatures is created first, and then the maximum temperature in list is used by Metropolis acceptance criterion to decide whether to accept a candidate solution. The temperature list is adapted iteratively according to the topology of the solution space of the problem. The effectiveness and the parameter sensitivity of the list-based cooling schedule are illustrated through benchmark TSP problems. The LBSA algorithm, whose performance is robust on a wide range of parameter values, shows competitive performance compared with some other state-of-the-art algorithms.

  6. Genetic Algorithm for Traveling Salesman Problem with Modified Cycle Crossover Operator

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    2017-01-01

    Full Text Available Genetic algorithms are evolutionary techniques used for optimization purposes according to survival of the fittest idea. These methods do not ensure optimal solutions; however, they give good approximation usually in time. The genetic algorithms are useful for NP-hard problems, especially the traveling salesman problem. The genetic algorithm depends on selection criteria, crossover, and mutation operators. To tackle the traveling salesman problem using genetic algorithms, there are various representations such as binary, path, adjacency, ordinal, and matrix representations. In this article, we propose a new crossover operator for traveling salesman problem to minimize the total distance. This approach has been linked with path representation, which is the most natural way to represent a legal tour. Computational results are also reported with some traditional path representation methods like partially mapped and order crossovers along with new cycle crossover operator for some benchmark TSPLIB instances and found improvements.

  7. Human Performance on the Traveling Salesman and Related Problems: A Review

    Science.gov (United States)

    MacGregor, James N.; Chu, Yun

    2011-01-01

    The article provides a review of recent research on human performance on the traveling salesman problem (TSP) and related combinatorial optimization problems. We discuss what combinatorial optimization problems are, why they are important, and why they may be of interest to cognitive scientists. We next describe the main characteristics of human…

  8. Facets for the Cardinality Constrained Quadratic Knapsack Problem and the Quadratic Selective Travelling Salesman Problem

    DEFF Research Database (Denmark)

    Mak, Vicky; Thomadsen, Tommy

    2004-01-01

    A well-known extension of the Travelling Salesman Problem (TSP) is the Selective (or Prize-collecting) TSP: In addition to the edge-costs, each node has an associated reward (denoted the node-reward) and instead of visiting all nodes, only profitable nodes are visited. The Quadratic Selective TSP...

  9. On the Equivalence between some Local and Global Chinese Postman and Traveling Salesman Graphs

    NARCIS (Netherlands)

    Granot, D.; Hamers, H.J.M.

    2000-01-01

    A connected graph G=(V,E), a vertex in V and a non-negative weight function defined on Ecan be used to induce Chinese postman and traveling salesman (cooperative) games. A graph G=(V,E) is said to be locally (respectively, globally) Chinese postman balanced (respectively, totally balanced,

  10. Well-solvable special cases of the Traveling Salesman Problem : a survey

    NARCIS (Netherlands)

    Burkard, R.E.; Deineko, V.G.; Dal, van R.; Veen, van der J.A.A.; Woeginger, G.J.

    1998-01-01

    The traveling salesman problem (TSP) belongs to the most basic, most important, and most investigated problems in combinatorial optimization. Although it is an ${\\cal NP}$-hard problem, many of its special cases can be solved efficiently in polynomial time. We survey these special cases with

  11. QUANTUM INSPIRED PARTICLE SWARM COMBINED WITH LIN-KERNIGHAN-HELSGAUN METHOD TO THE TRAVELING SALESMAN PROBLEM

    Directory of Open Access Journals (Sweden)

    Bruno Avila Leal de Meirelles Herrera

    2015-12-01

    Full Text Available ABSTRACT The Traveling Salesman Problem (TSP is one of the most well-known and studied problems of Operations Research field, more specifically, in the Combinatorial Optimization field. As the TSP is a NP (Non-Deterministic Polynomial time-hard problem, there are several heuristic methods which have been proposed for the past decades in the attempt to solve it the best possible way. The aim of this work is to introduce and to evaluate the performance of some approaches for achieving optimal solution considering some symmetrical and asymmetrical TSP instances, which were taken from the Traveling Salesman Problem Library (TSPLIB. The analyzed approaches were divided into three methods: (i Lin-Kernighan-Helsgaun (LKH algorithm; (ii LKH with initial tour based on uniform distribution; and (iii an hybrid proposal combining Particle Swarm Optimization (PSO with quantum inspired behavior and LKH for local search procedure. The tested algorithms presented promising results in terms of computational cost and solution quality.

  12. Heuristic methods using grasp, path relinking and variable neighborhood search for the clustered traveling salesman problem

    Directory of Open Access Journals (Sweden)

    Mário Mestria

    2013-08-01

    Full Text Available The Clustered Traveling Salesman Problem (CTSP is a generalization of the Traveling Salesman Problem (TSP in which the set of vertices is partitioned into disjoint clusters and objective is to find a minimum cost Hamiltonian cycle such that the vertices of each cluster are visited contiguously. The CTSP is NP-hard and, in this context, we are proposed heuristic methods for the CTSP using GRASP, Path Relinking and Variable Neighborhood Descent (VND. The heuristic methods were tested using Euclidean instances with up to 2000 vertices and clusters varying between 4 to 150 vertices. The computational tests were performed to compare the performance of the heuristic methods with an exact algorithm using the Parallel CPLEX software. The computational results showed that the hybrid heuristic method using VND outperforms other heuristic methods.

  13. An Extension of the Lin-Kernighan-Helsgaun TSP Solver for Constrained Traveling Salesman and Vehicle Routing Problems

    DEFF Research Database (Denmark)

    Helsgaun, Keld

    This report describes the implementation of an extension of the Lin-Kernighan-Helsgaun TSP solver for solving constrained traveling salesman and vehicle routing problems. The extension, which is called LKH-3, is able to solve a variety of well-known problems, including the sequential ordering...... problem (SOP), the traveling repairman problem (TRP), variants of the multiple travel-ing salesman problem (mTSP), as well as vehicle routing problems (VRPs) with capacity, time windows, pickup-and-delivery and distance constraints. The implementation of LKH-3 builds on the idea of transforming...... the problems into standard symmetric traveling salesman problems and handling constraints by means of penalty functions. Extensive testing on benchmark instances from the literature has shown that LKH-3 is effective. Best known solutions are often obtained, and in some cases, new best solutions are found...

  14. Penanganan Fuzzy Time Window pada Travelling Salesman Problem (TSP dengan Penerapan Algoritma Genetika

    Directory of Open Access Journals (Sweden)

    Gusti Eka Yuliastuti

    2017-03-01

    Full Text Available The route of the travel tour packages offered by travel agents is not considered optimum, so the level of satisfaction the tourist is not maximal. Selection of the route of the travel packages included in the traveling salesman problem (TSP. The problem that occurs is uncertain tourists visiting destinations at the best destinations timing hereinafter be referred to as the fuzzy time window problem. Therefore, the authors apply the genetic algorithm to solve the problem. Based on test results obtained optimum solution with the fitness value of 1.3291, a population size of 100, the number of generations of 1000, a combination of CR=0,4 and MR=0.6.

  15. PENYELESAIAN MULTI TRAVELING SALESMAN PROBLEM DENGAN ALGORITMA GENETIKA

    Directory of Open Access Journals (Sweden)

    NI KADEK MAYULIANA

    2017-01-01

    Full Text Available Genetic algorithm is a part of heuristic algorithm which can be applied to solve various computational problems. This work is directed to study the performance of the genetic algorithm (GA to solve Multi Traveling Salesmen Problem (multi-TSP. GA is simulated to determine the shortest route for 5 to 10 salesmen who travelled 10 to 30 cities. The performance of this algorithm is studied based on the minimum distance and the processing time required for 10 repetitions for each of cities-salesmen combination. The result showed that the minimum distance and the processing time of the GA increase consistently whenever the number of cities to visit increase. In addition, different number of sales who visited certain number of cities proved significantly affect the running time of GA, but did not prove significantly affect the minimum distance.

  16. The A-priori Traveling Salesman Problem with Time Windows

    DEFF Research Database (Denmark)

    Larsen, Allan; Madsen, Oli B.G.; Solomon, Marius M.

    2004-01-01

    seek to minimize lateness and examine the impact of this criterion choice on the distance traveled. Our focus on lateness is motivated by the problem faced by overnight mail service providers. We propose a real-time solution method that requires the vehicle, when idle, to wait at the current customer......In this paper we examine the traveling saleman problem with time windows for various degrees of dynamism. In contrast to the static problem, where the dispatcher can plan ahead, in the dynamic version, part or all of the necessary information becomes available only during the day of operation. We...... randomly generated data and on a real-world case study indicate that all policies proved capable of significantly reducing lateness. Our results also show that this can be accomplished with only small distance increases. The basic policy outperformed the other methods primarily when lateness and distance...

  17. Optimization of travel salesman problem using the ant colony system and Greedy search

    International Nuclear Information System (INIS)

    Esquivel E, J.; Ordonez A, A.; Ortiz S, J. J.

    2008-01-01

    In this paper we present some results obtained during the development of optimization systems that can be used to design refueling and patterns of control rods in a BWR. These systems use ant colonies and Greedy search. The first phase of this project is to be familiar with these optimization techniques applied to the problem of travel salesman problem (TSP). The utility of TSP study is that, like the refueling design and pattern design of control rods are problems of combinative optimization. Even, the similarity with the problem of the refueling design is remarkable. It is presented some results for the TSP with the 32 state capitals of Mexico country. (Author)

  18. TUTORIALS ON AFRICAN BUFFALO OPTIMIZATION FOR SOLVING THE TRAVELLING SALESMAN PROBLEM

    Directory of Open Access Journals (Sweden)

    Odili J.B

    2017-03-01

    Full Text Available The African Buffalo Optimization is a newly designed metaheuristic optimization algorithm inspired by the migration of African buffalos from place to place across the vast African forests, deserts and savannah in search of food. Being a new algorithm, several researchers from different parts of the research world have indicated huge interest in understanding the working of the novel algorithm. This paper presents a practical demonstration of the workings of the African Buffalo Optimization in solving the popular travelling salesman problem. It is our belief that this tutorial paper will be helpful in further introducing the new algorithm and making it user-friendly.

  19. Developing Programming Tools to Handle Traveling Salesman Problem by the Three Object-Oriented Languages

    Directory of Open Access Journals (Sweden)

    Hassan Ismkhan

    2014-01-01

    Full Text Available The traveling salesman problem (TSP is one of the most famous problems. Many applications and programming tools have been developed to handle TSP. However, it seems to be essential to provide easy programming tools according to state-of-the-art algorithms. Therefore, we have collected and programmed new easy tools by the three object-oriented languages. In this paper, we present ADT (abstract data type of developed tools at first; then we analyze their performance by experiments. We also design a hybrid genetic algorithm (HGA by developed tools. Experimental results show that the proposed HGA is comparable with the recent state-of-the-art applications.

  20. ON SAMPLING BASED METHODS FOR THE DUBINS TRAVELING SALESMAN PROBLEM WITH NEIGHBORHOODS

    Directory of Open Access Journals (Sweden)

    Petr Váňa

    2015-12-01

    Full Text Available In this paper, we address the problem of path planning to visit a set of regions by Dubins vehicle, which is also known as the Dubins Traveling Salesman Problem Neighborhoods (DTSPN. We propose a modification of the existing sampling-based approach to determine increasing number of samples per goal region and thus improve the solution quality if a more computational time is available. The proposed modification of the sampling-based algorithm has been compared with performance of existing approaches for the DTSPN and results of the quality of the found solutions and the required computational time are presented in the paper.

  1. Efficient Constraint Handling in Electromagnetism-Like Algorithm for Traveling Salesman Problem with Time Windows

    Science.gov (United States)

    Yurtkuran, Alkın

    2014-01-01

    The traveling salesman problem with time windows (TSPTW) is a variant of the traveling salesman problem in which each customer should be visited within a given time window. In this paper, we propose an electromagnetism-like algorithm (EMA) that uses a new constraint handling technique to minimize the travel cost in TSPTW problems. The EMA utilizes the attraction-repulsion mechanism between charged particles in a multidimensional space for global optimization. This paper investigates the problem-specific constraint handling capability of the EMA framework using a new variable bounding strategy, in which real-coded particle's boundary constraints associated with the corresponding time windows of customers, is introduced and combined with the penalty approach to eliminate infeasibilities regarding time window violations. The performance of the proposed algorithm and the effectiveness of the constraint handling technique have been studied extensively, comparing it to that of state-of-the-art metaheuristics using several sets of benchmark problems reported in the literature. The results of the numerical experiments show that the EMA generates feasible and near-optimal results within shorter computational times compared to the test algorithms. PMID:24723834

  2. Efficient Constraint Handling in Electromagnetism-Like Algorithm for Traveling Salesman Problem with Time Windows

    Directory of Open Access Journals (Sweden)

    Alkın Yurtkuran

    2014-01-01

    Full Text Available The traveling salesman problem with time windows (TSPTW is a variant of the traveling salesman problem in which each customer should be visited within a given time window. In this paper, we propose an electromagnetism-like algorithm (EMA that uses a new constraint handling technique to minimize the travel cost in TSPTW problems. The EMA utilizes the attraction-repulsion mechanism between charged particles in a multidimensional space for global optimization. This paper investigates the problem-specific constraint handling capability of the EMA framework using a new variable bounding strategy, in which real-coded particle’s boundary constraints associated with the corresponding time windows of customers, is introduced and combined with the penalty approach to eliminate infeasibilities regarding time window violations. The performance of the proposed algorithm and the effectiveness of the constraint handling technique have been studied extensively, comparing it to that of state-of-the-art metaheuristics using several sets of benchmark problems reported in the literature. The results of the numerical experiments show that the EMA generates feasible and near-optimal results within shorter computational times compared to the test algorithms.

  3. Ant Colony Optimization ACO For The Traveling Salesman Problem TSP Using Partitioning

    Directory of Open Access Journals (Sweden)

    Alok Bajpai

    2015-08-01

    Full Text Available Abstract An ant colony optimization is a technique which was introduced in 1990s and which can be applied to a variety of discrete combinatorial optimization problem and to continuous optimization. The ACO algorithm is simulated with the foraging behavior of the real ants to find the incremental solution constructions and to realize a pheromone laying-and-following mechanism. This pheromone is the indirect communication among the ants. In this paper we introduces the partitioning technique based on the divide and conquer strategy for the traveling salesman problem which is one of the most important combinatorial problem in which the original problem is partitioned into the group of sub problems. And then we apply the ant colony algorithm using candidate list strategy for each smaller sub problems. After that by applying the local optimization and combining the sub problems to find the good solution for the original problem by improving the exploration efficiency of the ants. At the end of this paper we have also be presented the comparison of result with the normal ant colony system for finding the optimal solution to the traveling salesman problem.

  4. How Much is Location Information Worth? A Competitive Analysis of the Online Traveling Salesman Problem with Two Disclosure Dates

    NARCIS (Netherlands)

    F.J. Srour (Jordan); R.A. Zuidwijk (Rob)

    2008-01-01

    textabstractIn this paper we derive the worst-case ratio of an online algorithm for the Traveling Salesman Problem (TSP) with two disclosure dates. This problem, a variant of the online TSP with release dates, is characterized by the disclosure of a job’s location at one point in time followed by

  5. An Efficient Combined Meta-Heuristic Algorithm for Solving the Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Majid Yousefikhoshbakht

    2016-08-01

    Full Text Available The traveling salesman problem (TSP is one of the most important NP-hard Problems and probably the most famous and extensively studied problem in the field of combinatorial optimization. In this problem, a salesman is required to visit each of n given nodes once and only once, starting from any node and returning to the original place of departure. This paper presents an efficient evolutionary optimization algorithm developed through combining imperialist competitive algorithm and lin-kernighan algorithm called (MICALK in order to solve the TSP. The MICALK is tested on 44 TSP instances involving from 24 to 1655 nodes from the literature so that 26 best known solutions of the benchmark problem are also found by our algorithm. Furthermore, the performance of MICALK is compared with several metaheuristic algorithms, including GA, BA, IBA, ICA, GSAP, ABO, PSO and BCO on 32 instances from TSPLIB. The results indicate that the MICALK performs well and is quite competitive with the above algorithms.

  6. An new self-organizing maps strategy for solving the traveling salesman problem

    International Nuclear Information System (INIS)

    Bai Yanping; Zhang Wendong; Jin Zhen

    2006-01-01

    This paper presents an approach to the well-known traveling salesman problem (TSP) using self-organizing maps (SOM). There are many types of SOM algorithms to solve the TSP found in the literature, whereas the purpose of this paper is to look for the incorporation of an efficient initialization methods and the definition of a parameters adaptation law to achieve better results and a faster convergence. Aspects of parameters adaptation, selecting the number of nodes of neurons, index of winner neurons and effect of the initial ordering of the cities, as well as the initial synaptic weights of the modified SOM algorithm are discussed. The complexity of the modified SOM algorithm is analyzed. The simulated results show an average deviation of 2.32% from the optimal tour length for a set of 12 TSP instances

  7. Improved Genetic and Simulating Annealing Algorithms to Solve the Traveling Salesman Problem Using Constraint Programming

    Directory of Open Access Journals (Sweden)

    M. Abdul-Niby

    2016-04-01

    Full Text Available The Traveling Salesman Problem (TSP is an integer programming problem that falls into the category of NP-Hard problems. As the problem become larger, there is no guarantee that optimal tours will be found within reasonable computation time. Heuristics techniques, like genetic algorithm and simulating annealing, can solve TSP instances with different levels of accuracy. Choosing which algorithm to use in order to get a best solution is still considered as a hard choice. This paper suggests domain reduction as a tool to be combined with any meta-heuristic so that the obtained results will be almost the same. The hybrid approach of combining domain reduction with any meta-heuristic encountered the challenge of choosing an algorithm that matches the TSP instance in order to get the best results.

  8. A Computational Analysis of the Traveling Salesman and Cutting Stock Problems

    Directory of Open Access Journals (Sweden)

    Gracia María D.

    2015-01-01

    Full Text Available The aim of this article is to perform a computational study to analyze the impact of formulations, and the solution strategy on the algorithmic performance of two classical optimization problems: the traveling salesman problem and the cutting stock problem. In order to assess the algorithmic performance on both problems three dependent variables were used: solution quality, computing time and number of iterations. The results are useful for choosing the solution approach to each specific problem. In the STSP, the results demonstrate that the multistage decision formulation is better than the conventional formulations, by solving 90.47% of the instances compared with MTZ (76.19% and DFJ (14.28%. The results of the CSP demonstrate that the cutting patterns formulation is better than the standard formulation with symmetry breaking inequalities, when the objective function is to minimize the loss of trim when cutting the rolls.

  9. Solution for a bipartite Euclidean traveling-salesman problem in one dimension

    Science.gov (United States)

    Caracciolo, Sergio; Di Gioacchino, Andrea; Gherardi, Marco; Malatesta, Enrico M.

    2018-05-01

    The traveling-salesman problem is one of the most studied combinatorial optimization problems, because of the simplicity in its statement and the difficulty in its solution. We characterize the optimal cycle for every convex and increasing cost function when the points are thrown independently and with an identical probability distribution in a compact interval. We compute the average optimal cost for every number of points when the distance function is the square of the Euclidean distance. We also show that the average optimal cost is not a self-averaging quantity by explicitly computing the variance of its distribution in the thermodynamic limit. Moreover, we prove that the cost of the optimal cycle is not smaller than twice the cost of the optimal assignment of the same set of points. Interestingly, this bound is saturated in the thermodynamic limit.

  10. An new self-organizing maps strategy for solving the traveling salesman problem

    Energy Technology Data Exchange (ETDEWEB)

    Bai Yanping [Key Lab of Instrument Science and Dynamic Measurement of Ministry of Education, North University of China, No. 3, Xueyuan Road, TaiYuan, ShanXi 030051 (China)]. E-mail: baiyp@nuc.edu.cn; Zhang Wendong [Key Lab of Instrument Science and Dynamic Measurement of Ministry of Education, North University of China, No. 3, Xueyuan Road, TaiYuan, ShanXi 030051 (China)]. E-mail: wdzhang@nuc.edu.cn; Jin Zhen [Department of Applied Mathematics, North University of China, No. 3 Xueyuan Road, TaiYuan, ShanXi 030051 (China)

    2006-05-15

    This paper presents an approach to the well-known traveling salesman problem (TSP) using self-organizing maps (SOM). There are many types of SOM algorithms to solve the TSP found in the literature, whereas the purpose of this paper is to look for the incorporation of an efficient initialization methods and the definition of a parameters adaptation law to achieve better results and a faster convergence. Aspects of parameters adaptation, selecting the number of nodes of neurons, index of winner neurons and effect of the initial ordering of the cities, as well as the initial synaptic weights of the modified SOM algorithm are discussed. The complexity of the modified SOM algorithm is analyzed. The simulated results show an average deviation of 2.32% from the optimal tour length for a set of 12 TSP instances.

  11. A population-based algorithm for the multi travelling salesman problem

    Directory of Open Access Journals (Sweden)

    Rubén Iván Bolaños

    2016-04-01

    Full Text Available This paper presents the implementation of an efficient modified genetic algorithm for solving the multi-traveling salesman problem (mTSP. The main characteristics of the method are the construction of an initial population of high quality and the implementation of several local search operators which are important in the efficient and effective exploration of promising regions of the solution space. Due to the combinatorial complexity of mTSP, the proposed methodology is especially applicable for real-world problems. The proposed algorithm was tested on a set of six benchmark instances, which have from 76 and 1002 cities to be visited. In all cases, the best known solution was improved. The results are also compared with other existing solutions procedure in the literature.

  12. A combination of genetic algorithm and particle swarm optimization method for solving traveling salesman problem

    Directory of Open Access Journals (Sweden)

    Keivan Borna

    2015-12-01

    Full Text Available Traveling salesman problem (TSP is a well-established NP-complete problem and many evolutionary techniques like particle swarm optimization (PSO are used to optimize existing solutions for that. PSO is a method inspired by the social behavior of birds. In PSO, each member will change its position in the search space, according to personal or social experience of the whole society. In this paper, we combine the principles of PSO and crossover operator of genetic algorithm to propose a heuristic algorithm for solving the TSP more efficiently. Finally, some experimental results on our algorithm are applied in some instances in TSPLIB to demonstrate the effectiveness of our methods which also show that our algorithm can achieve better results than other approaches.

  13. A Data-Guided Lexisearch Algorithm for the Asymmetric Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Zakir Hussain Ahmed

    2011-01-01

    Full Text Available A simple lexisearch algorithm that uses path representation method for the asymmetric traveling salesman problem (ATSP is proposed, along with an illustrative example, to obtain exact optimal solution to the problem. Then a data-guided lexisearch algorithm is presented. First, the cost matrix of the problem is transposed depending on the variance of rows and columns, and then the simple lexisearch algorithm is applied. It is shown that this minor preprocessing of the data before the simple lexisearch algorithm is applied improves the computational time substantially. The efficiency of our algorithms to the problem against two existing algorithms has been examined for some TSPLIB and random instances of various sizes. The results show remarkably better performance of our algorithms, especially our data-guided algorithm.

  14. A High-Performance Genetic Algorithm: Using Traveling Salesman Problem as a Case

    Directory of Open Access Journals (Sweden)

    Chun-Wei Tsai

    2014-01-01

    Full Text Available This paper presents a simple but efficient algorithm for reducing the computation time of genetic algorithm (GA and its variants. The proposed algorithm is motivated by the observation that genes common to all the individuals of a GA have a high probability of surviving the evolution and ending up being part of the final solution; as such, they can be saved away to eliminate the redundant computations at the later generations of a GA. To evaluate the performance of the proposed algorithm, we use it not only to solve the traveling salesman problem but also to provide an extensive analysis on the impact it may have on the quality of the end result. Our experimental results indicate that the proposed algorithm can significantly reduce the computation time of GA and GA-based algorithms while limiting the degradation of the quality of the end result to a very small percentage compared to traditional GA.

  15. Discrete Teaching-learning-based optimization Algorithm for Traveling Salesman Problems

    Directory of Open Access Journals (Sweden)

    Wu Lehui

    2017-01-01

    Full Text Available In this paper, a discrete variant of TLBO (DTLBO is proposed for solving the traveling salesman problem (TSP. In the proposed method, an effective learner representation scheme is redefined based on the characteristics of TSP problem. Moreover, all learners are randomly divided into several sub-swarms with equal amounts of learners so as to increase the diversity of population and reduce the probability of being trapped in local optimum. In each sub-swarm, the new positions of learners in the teaching phase and the learning phase are generated by the crossover operation, the legality detection and mutation operation, and then the offspring learners are determined based on greedy selection. Finally, to verify the performance of the proposed algorithm, benchmark TSP problems are examined and the results indicate that DTLBO is effective compared with other algorithms used for TSP problems.

  16. Method for the traveling salesman problem by controlling two parameters of the Hopfield neural network; Parameter seigyogata hop field net ni yoru junkai salesman mondai no kaiho

    Energy Technology Data Exchange (ETDEWEB)

    Setsu, N.; Murakami, K.; Ohori, T.; Watanabe, K. [Hokkaido Institute of Technology, Sapporo (Japan)

    1996-01-20

    For solving the traveling salesman problem (TSP) by using a continuous value outputting neural net (NN), an investigation was given on the accuracy of solution and the possibility on traveling routes by using the penalty coefficient and temperature as the parameters for energy functions. The parameter range to obtain high-quality traveling routes was shown by a numerical experiment. The experimental result revealed that, when the penalty coefficient `r` is large, the traveling route possibility tends to become higher, but the route length increases, and when the `r` is small, the traveling route possibility becomes lower, but the route length decreases, also in the continuous value outputting NN as in the two-value outputting NN. Noticing this fact, and in order to improve the traveling route possibility as well as the solution quality, a method was proposed to expand the penalty control method which was proposed previously by the authors on the two-value outputting NN, into the continuous value outputting NN. In addition, a proposal was also made on a method to derive an optimal temperature efficiently by using the golden section method. It was found that the relative error has been reduced by 48% on the average as compared with that in the conventional method in which the temperature is fixed. 6 refs., 5 figs.

  17. A multiobjective non-dominated sorting genetic algorithm (NSGA-II for the Multiple Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Rubén Iván Bolaños

    2015-06-01

    Full Text Available This paper considers a multi-objective version of the Multiple Traveling Salesman Problem (MOmTSP. In particular, two objectives are considered: the minimization of the total traveled distance and the balance of the working times of the traveling salesmen. The problem is formulated as an integer multi-objective optimization model. A non-dominated sorting genetic algorithm (NSGA-II is proposed to solve the MOmTSP. The solution scheme allows one to find a set of ordered solutions in Pareto fronts by considering the concept of dominance. Tests on real world instances and instances adapted from the literature show the effectiveness of the proposed algorithm.

  18. An approach using quantum PBIL to solve the traveling salesman problem

    International Nuclear Information System (INIS)

    Silva, Marcio Henrique; Schirru, Roberto

    2011-01-01

    Quantum inspired evolutionary algorithms are optimization tools based in artificial intelligence developed to simulate the quantum processing in classical computers viewing that there are not quantum computers available nowadays. In this work is introduced one of these tools, which adds quantum concepts such as the linear superposition of states and the qubit representation to standard PBIL named Quantum PBIL. Here we use Quantum PBIL to solve a well-known NPHard benchmark, the Traveling salesman problem. The objective is to find the shorter path made by a traveler linking all the available cities visiting each one only once and returning to the starter one at the final of his journey. As the main purpose of this work is employ the algorithm to solve the nuclear reload optimization in the future, and according to the similarities that both problems share, TSP is a good challenge for Quantum PBIL. The results have shown that the algorithm is able to obtain good performance when applied on this problem. It is also fast and has a great capacity to find good solutions when compared to other versions of PBIL found in literature despite of its stagnation of bits tendency can easily lead it to local minimums. (author)

  19. Optimization of Multiple Traveling Salesman Problem Based on Simulated Annealing Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Xu Mingji

    2017-01-01

    Full Text Available It is very effective to solve the multi variable optimization problem by using hierarchical genetic algorithm. This thesis analyzes both advantages and disadvantages of hierarchical genetic algorithm and puts forward an improved simulated annealing genetic algorithm. The new algorithm is applied to solve the multiple traveling salesman problem, which can improve the performance of the solution. First, it improves the design of chromosomes hierarchical structure in terms of redundant hierarchical algorithm, and it suggests a suffix design of chromosomes; Second, concerning to some premature problems of genetic algorithm, it proposes a self-identify crossover operator and mutation; Third, when it comes to the problem of weak ability of local search of genetic algorithm, it stretches the fitness by mixing genetic algorithm with simulated annealing algorithm. Forth, it emulates the problems of N traveling salesmen and M cities so as to verify its feasibility. The simulation and calculation shows that this improved algorithm can be quickly converged to a best global solution, which means the algorithm is encouraging in practical uses.

  20. An approach using quantum PBIL to solve the traveling salesman problem

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcio Henrique; Schirru, Roberto, E-mail: marciohenrique@lmp.ufrj.br, E-mail: schirru@lmp.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEN/COPPE), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Quantum inspired evolutionary algorithms are optimization tools based in artificial intelligence developed to simulate the quantum processing in classical computers viewing that there are not quantum computers available nowadays. In this work is introduced one of these tools, which adds quantum concepts such as the linear superposition of states and the qubit representation to standard PBIL named Quantum PBIL. Here we use Quantum PBIL to solve a well-known NPHard benchmark, the Traveling salesman problem. The objective is to find the shorter path made by a traveler linking all the available cities visiting each one only once and returning to the starter one at the final of his journey. As the main purpose of this work is employ the algorithm to solve the nuclear reload optimization in the future, and according to the similarities that both problems share, TSP is a good challenge for Quantum PBIL. The results have shown that the algorithm is able to obtain good performance when applied on this problem. It is also fast and has a great capacity to find good solutions when compared to other versions of PBIL found in literature despite of its stagnation of bits tendency can easily lead it to local minimums. (author)

  1. Global approach to the n-dimensional traveling salesman problem: Application to the optimization of crystallographic data collection

    Energy Technology Data Exchange (ETDEWEB)

    Weinrach, J.B.; Bennett, D.W.

    1987-12-01

    An algorithm for the optimization of data collection time has been written and a subsequent computer program tested for diffractometer systems. The program, which utilizes a global statistical approach to the traveling salesman problem, yields reasonable solutions in a relatively short time. The algorithm has been successful in treating very large data sets (up to 4000 points) in three dimensions with subsequent time savings of ca 30%.

  2. A Hybrid Symbiotic Organisms Search Algorithm with Variable Neighbourhood Search for Solving Symmetric and Asymmetric Traveling Salesman Problem

    Science.gov (United States)

    Umam, M. I. H.; Santosa, B.

    2018-04-01

    Combinatorial optimization has been frequently used to solve both problems in science, engineering, and commercial applications. One combinatorial problems in the field of transportation is to find a shortest travel route that can be taken from the initial point of departure to point of destination, as well as minimizing travel costs and travel time. When the distance from one (initial) node to another (destination) node is the same with the distance to travel back from destination to initial, this problems known to the Traveling Salesman Problem (TSP), otherwise it call as an Asymmetric Traveling Salesman Problem (ATSP). The most recent optimization techniques is Symbiotic Organisms Search (SOS). This paper discuss how to hybrid the SOS algorithm with variable neighborhoods search (SOS-VNS) that can be applied to solve the ATSP problem. The proposed mechanism to add the variable neighborhoods search as a local search is to generate the better initial solution and then we modify the phase of parasites with adapting mechanism of mutation. After modification, the performance of the algorithm SOS-VNS is evaluated with several data sets and then the results is compared with the best known solution and some algorithm such PSO algorithm and SOS original algorithm. The SOS-VNS algorithm shows better results based on convergence, divergence and computing time.

  3. Traveling salesman problems with PageRank Distance on complex networks reveal community structure

    Science.gov (United States)

    Jiang, Zhongzhou; Liu, Jing; Wang, Shuai

    2016-12-01

    In this paper, we propose a new algorithm for community detection problems (CDPs) based on traveling salesman problems (TSPs), labeled as TSP-CDA. Since TSPs need to find a tour with minimum cost, cities close to each other are usually clustered in the tour. This inspired us to model CDPs as TSPs by taking each vertex as a city. Then, in the final tour, the vertices in the same community tend to cluster together, and the community structure can be obtained by cutting the tour into a couple of paths. There are two challenges. The first is to define a suitable distance between each pair of vertices which can reflect the probability that they belong to the same community. The second is to design a suitable strategy to cut the final tour into paths which can form communities. In TSP-CDA, we deal with these two challenges by defining a PageRank Distance and an automatic threshold-based cutting strategy. The PageRank Distance is designed with the intrinsic properties of CDPs in mind, and can be calculated efficiently. In the experiments, benchmark networks with 1000-10,000 nodes and varying structures are used to test the performance of TSP-CDA. A comparison is also made between TSP-CDA and two well-established community detection algorithms. The results show that TSP-CDA can find accurate community structure efficiently and outperforms the two existing algorithms.

  4. Optimal solution for travelling salesman problem using heuristic shortest path algorithm with imprecise arc length

    Science.gov (United States)

    Bakar, Sumarni Abu; Ibrahim, Milbah

    2017-08-01

    The shortest path problem is a popular problem in graph theory. It is about finding a path with minimum length between a specified pair of vertices. In any network the weight of each edge is usually represented in a form of crisp real number and subsequently the weight is used in the calculation of shortest path problem using deterministic algorithms. However, due to failure, uncertainty is always encountered in practice whereby the weight of edge of the network is uncertain and imprecise. In this paper, a modified algorithm which utilized heuristic shortest path method and fuzzy approach is proposed for solving a network with imprecise arc length. Here, interval number and triangular fuzzy number in representing arc length of the network are considered. The modified algorithm is then applied to a specific example of the Travelling Salesman Problem (TSP). Total shortest distance obtained from this algorithm is then compared with the total distance obtained from traditional nearest neighbour heuristic algorithm. The result shows that the modified algorithm can provide not only on the sequence of visited cities which shown to be similar with traditional approach but it also provides a good measurement of total shortest distance which is lesser as compared to the total shortest distance calculated using traditional approach. Hence, this research could contribute to the enrichment of methods used in solving TSP.

  5. Hierarchical Solution of the Traveling Salesman Problem with Random Dyadic Tilings

    Science.gov (United States)

    Kalmár-Nagy, Tamás; Bak, Bendegúz Dezső

    We propose a hierarchical heuristic approach for solving the Traveling Salesman Problem (TSP) in the unit square. The points are partitioned with a random dyadic tiling and clusters are formed by the points located in the same tile. Each cluster is represented by its geometrical barycenter and a “coarse” TSP solution is calculated for these barycenters. Midpoints are placed at the middle of each edge in the coarse solution. Near-optimal (or optimal) minimum tours are computed for each cluster. The tours are concatenated using the midpoints yielding a solution for the original TSP. The method is tested on random TSPs (independent, identically distributed points in the unit square) up to 10,000 points as well as on a popular benchmark problem (att532 — coordinates of 532 American cities). Our solutions are 8-13% longer than the optimal ones. We also present an optimization algorithm for the partitioning to improve our solutions. This algorithm further reduces the solution errors (by several percent using 1000 iteration steps). The numerical experiments demonstrate the viability of the approach.

  6. Advanced Harmony Search with Ant Colony Optimization for Solving the Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Ho-Yoeng Yun

    2013-01-01

    Full Text Available We propose a novel heuristic algorithm based on the methods of advanced Harmony Search and Ant Colony Optimization (AHS-ACO to effectively solve the Traveling Salesman Problem (TSP. The TSP, in general, is well known as an NP-complete problem, whose computational complexity increases exponentially by increasing the number of cities. In our algorithm, Ant Colony Optimization (ACO is used to search the local optimum in the solution space, followed by the use of the Harmony Search to escape the local optimum determined by the ACO and to move towards a global optimum. Experiments were performed to validate the efficiency of our algorithm through a comparison with other algorithms and the optimum solutions presented in the TSPLIB. The results indicate that our algorithm is capable of generating the optimum solution for most instances in the TSPLIB; moreover, our algorithm found better solutions in two cases (kroB100 and pr144 when compared with the optimum solution presented in the TSPLIB.

  7. Automatic Combination of Operators in a Genetic Algorithm to Solve the Traveling Salesman Problem.

    Directory of Open Access Journals (Sweden)

    Carlos Contreras-Bolton

    Full Text Available Genetic algorithms are powerful search methods inspired by Darwinian evolution. To date, they have been applied to the solution of many optimization problems because of the easy use of their properties and their robustness in finding good solutions to difficult problems. The good operation of genetic algorithms is due in part to its two main variation operators, namely, crossover and mutation operators. Typically, in the literature, we find the use of a single crossover and mutation operator. However, there are studies that have shown that using multi-operators produces synergy and that the operators are mutually complementary. Using multi-operators is not a simple task because which operators to use and how to combine them must be determined, which in itself is an optimization problem. In this paper, it is proposed that the task of exploring the different combinations of the crossover and mutation operators can be carried out by evolutionary computing. The crossover and mutation operators used are those typically used for solving the traveling salesman problem. The process of searching for good combinations was effective, yielding appropriate and synergic combinations of the crossover and mutation operators. The numerical results show that the use of the combination of operators obtained by evolutionary computing is better than the use of a single operator and the use of multi-operators combined in the standard way. The results were also better than those of the last operators reported in the literature.

  8. A GPU Implementation of Local Search Operators for Symmetric Travelling Salesman Problem

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    Juraj Fosin

    2013-06-01

    Full Text Available The Travelling Salesman Problem (TSP is one of the most studied combinatorial optimization problem which is significant in many practical applications in transportation problems. The TSP problem is NP-hard problem and requires large computation power to be solved by the exact algorithms. In the past few years, fast development of general-purpose Graphics Processing Units (GPUs has brought huge improvement in decreasing the applications’ execution time. In this paper, we implement 2-opt and 3-opt local search operators for solving the TSP on the GPU using CUDA. The novelty presented in this paper is a new parallel iterated local search approach with 2-opt and 3-opt operators for symmetric TSP, optimized for the execution on GPUs. With our implementation large TSP problems (up to 85,900 cities can be solved using the GPU. We will show that our GPU implementation can be up to 20x faster without losing quality for all TSPlib problems as well as for our CRO TSP problem.

  9. Computational Recognition of RNA Splice Sites by Exact Algorithms for the Quadratic Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Anja Fischer

    2015-06-01

    Full Text Available One fundamental problem of bioinformatics is the computational recognition of DNA and RNA binding sites. Given a set of short DNA or RNA sequences of equal length such as transcription factor binding sites or RNA splice sites, the task is to learn a pattern from this set that allows the recognition of similar sites in another set of DNA or RNA sequences. Permuted Markov (PM models and permuted variable length Markov (PVLM models are two powerful models for this task, but the problem of finding an optimal PM model or PVLM model is NP-hard. While the problem of finding an optimal PM model or PVLM model of order one is equivalent to the traveling salesman problem (TSP, the problem of finding an optimal PM model or PVLM model of order two is equivalent to the quadratic TSP (QTSP. Several exact algorithms exist for solving the QTSP, but it is unclear if these algorithms are capable of solving QTSP instances resulting from RNA splice sites of at least 150 base pairs in a reasonable time frame. Here, we investigate the performance of three exact algorithms for solving the QTSP for ten datasets of splice acceptor sites and splice donor sites of five different species and find that one of these algorithms is capable of solving QTSP instances of up to 200 base pairs with a running time of less than two days.

  10. A Discrete Fruit Fly Optimization Algorithm for the Traveling Salesman Problem.

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    Zi-Bin Jiang

    Full Text Available The fruit fly optimization algorithm (FOA is a newly developed bio-inspired algorithm. The continuous variant version of FOA has been proven to be a powerful evolutionary approach to determining the optima of a numerical function on a continuous definition domain. In this study, a discrete FOA (DFOA is developed and applied to the traveling salesman problem (TSP, a common combinatorial problem. In the DFOA, the TSP tour is represented by an ordering of city indices, and the bio-inspired meta-heuristic search processes are executed with two elaborately designed main procedures: the smelling and tasting processes. In the smelling process, an effective crossover operator is used by the fruit fly group to search for the neighbors of the best-known swarm location. During the tasting process, an edge intersection elimination (EXE operator is designed to improve the neighbors of the non-optimum food location in order to enhance the exploration performance of the DFOA. In addition, benchmark instances from the TSPLIB are classified in order to test the searching ability of the proposed algorithm. Furthermore, the effectiveness of the proposed DFOA is compared to that of other meta-heuristic algorithms. The results indicate that the proposed DFOA can be effectively used to solve TSPs, especially large-scale problems.

  11. Kombinasi Firefly Algorithm-Tabu Search untuk Penyelesaian Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Riyan Naufal Hay's

    2017-07-01

    Full Text Available Traveling Salesman Problem (TSP adalah masalah optimasi kombinatorial klasik dan memiliki peran dalam perencanaan, penjadwalan, dan pencarian pada bidang rekayasa dan pengetahuan (Dong, 2012. TSP juga merupakan objek yang baik untuk menguji kinerja metode optimasi, beberapa metode seperti Cooperative Genetic Ant System (CGAS (Dong, 2012, Parallelized Genetic Ant Colony System (PGAS Particle Swarm Optimization and Ant Colony Optimization Algorithms (PSO–ACO (Elloumi, 2014, dan Ant Colony Hyper-Heuristics (ACO HH (Aziz, 2015 telah dikembangkan untuk memecahkan TSP. Sehingga, pada penelitian ini diimplementasikan kombinasi metode baru untuk meningkatkan akurasi penyelesaian TSP. Firefly Algorithm (FA merupakan salah satu algoritma yang dapat digunakan untuk memecahkan masalah optimasi kombinatorial (Layeb, 2014. FA merupakan algoritma yang berpotensi kuat dalam memecahkan kasus optimasi dibanding algoritma yang ada termasuk Particle Swarm Optimization (Yang, 2010. Namun, FA memiliki kekurangan dalam memecahkan masalah optimasi dengan skala besar (Baykasoğlu dan Ozsoy, 2014. Tabu Search (TS merupakan metode optimasi yang terbukti efektif untuk memecahkan masalah optimasi dengan skala besar (Pedro, 2013. Pada penelitian ini, TS akan diterapkan pada FA (FATS untuk memecahkan kasus TSP. Hasil FATS akan dibandingkan terhadap penelitian sebelumnya yaitu ACOHH. Perbandingan hasil menunjukan peningkatan akurasi sebesar 0.89% pada dataset Oliver30, 0.14% dataset Eil51, 3.81% dataset Eil76 dan 1.27% dataset KroA100.

  12. PEMANFAATAN TEKNOLOGI GOOGLE MAPS UNTUK PENYELESAIAN ONLINE TRAVELLING SALESMAN PROBLEM (TSP BERBASIS GEOGRAFIS DENGAN MENGGUNAKAN ALGORITMA HEURISTIK

    Directory of Open Access Journals (Sweden)

    Wahyudi Agustiono

    2010-07-01

    Full Text Available Travelling Salesman Problem (TSP adalah salah satu metode klasik dalam proses pemecahan masalah optimasi dan penemuan rute terpendek dari sebuah rute perjalanan yang melewati beberapa titik lokasi. Oleh karena kehandalan metode ini banyak sekali algoritma dan metode optimasi yang mencoba memecahkan TSP dalam banyak penelitian. Sebagin besar hasil dari rangkaian ujicoba tersebut berupa kombinasi teroptimal dari rangkaian perjalanan salesman yang umumnya digambarkan dalam sebuah graph. Namun belum banyak penelitian yang menerapkan TSP pada data spasial atau geografis seperti Google Maps yang dapat memberikan representasi nyata permasalahan TSP dalam menemukan rute perjalanan melewati titik-titik wilayah di muka bumi. Dibandingkan dengan representasi graph, Google Maps memiliki kemampuan tidak sekedar menampilkan rute perjalanan akan tetapi juga dapat menyajikan informasi yang lebih komprehensif, interaktif dan faktual. Penelitian ini bertujuan untuk menerapkan metode TSP pada layanan data spasial sehingga akan dihasilkan visualisasi secara riil dari alternatif rute perjalanan salesman. Sebagai basis dari data spasial, penelitian ini memanfaatkan Google Maps Mashup untuk mendapatkan informasi rute yang lebih aktual, interaktif, dan komprehensif.

  13. The Application of Fitness Sharing Method in Evolutionary Algorithm to Optimizing the Travelling Salesman Problem (TSP

    Directory of Open Access Journals (Sweden)

    Nurmaulidar Nurmaulidar

    2015-04-01

    Full Text Available Travelling Salesman Problem (TSP is one of complex optimization problem that is difficult to be solved, and require quite a long time for a large number of cities. Evolutionary algorithm is a precise algorithm used in solving complex optimization problem as it is part of heuristic method. Evolutionary algorithm, like many other algorithms, also experiences a premature convergence phenomenon, whereby variation is eliminated from a population of fairly fit individuals before a complete solution is achieved. Therefore it requires a method to delay the convergence. A specific method of fitness sharing called phenotype fitness sharing has been used in this research. The aim of this research is to find out whether fitness sharing in evolutionary algorithm is able to optimize TSP. There are two concepts of evolutionary algorithm being used in this research. the first one used single elitism and the other one used federated solution. The two concepts had been tested to the method of fitness sharing by using the threshold of 0.25, 0.50 and 0.75. The result was then compared to a non fitness sharing method. The result in this study indicated that by using single elitism concept, fitness sharing was able to give a more optimum result for the data of 100-1000 cities. On the other hand, by using federation solution concept, fitness sharing can yield a more optimum result for the data above 1000 cities, as well as a better solution of data-spreading compared to the method without fitness sharing.

  14. On the Optimization and Parallelizing Little Algorithm for Solving the Traveling Salesman Problem

    Directory of Open Access Journals (Sweden)

    V. V. Vasilchikov

    2016-01-01

    Full Text Available The paper describes some ways to accelerate solving the NP-complete Traveling Salesman Problem. The classic Little algorithm belonging to the category of ”branch and bound methods” can solve it both for directed and undirected graphs. However, for undirected graphs its operation can be accelerated by eliminating the consideration of branches examined earlier. The paper proposes changes to be made in the key operations of the algorithm to speed up its execution. It also describes the results of an experiment that demonstrated a significant acceleration of solving the problem by using an advanced algorithm. Another way to speed up the work is to parallelize the algorithm. For problems of this kind it is difficult to break the task into a sufficient number of subtasks having comparable complexity. Their parallelism arises dynamically during the execution. For such problems, it seems reasonable to use parallel-recursive algorithms. In our case the use of the library RPM ParLib developed by the author was a good choice. It allows us to develop effective applications for parallel computing on a local network using any .NET-compatible programming language. We used C# to develop the programs. Parallel applications were developed as for basic and modified algorithms, the comparing of their speed was made. Experiments were performed for the graphs with the number of vertexes up to 45 and with the number of network computers up to 16. We also investigated the acceleration that can be achieved by parallelizing the basic Little algorithm for directed graphs. The results of these experiments are also presented in the paper. 

  15. Genetic algorithm based on virus theory of evolution for traveling salesman problem; Virus shinkaron ni motozuku identeki algorithm no junkai salesman mondai eno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, N. [Osaka Inst. of Technology, Osaka (Japan); Fukuda, T. [Nagoya University, Nagoya (Japan)

    1998-05-31

    This paper deals with virus evolutionary genetic algorithm. The genetic algorithms (GAs) have been demonstrated its effectiveness in optimization problems in these days. In general, the GAs simulate the survival of fittest by natural selection and the heredity of the Darwin`s theory of evolution. However, some types of evolutionary hypotheses such as neutral theory of molecular evolution, Imanishi`s evolutionary theory, serial symbiosis theory, and virus theory of evolution, have been proposed in addition to the Darwinism. Virus theory of evolution is based on the view that the virus transduction is a key mechanism for transporting segments of DNA across species. This paper proposes genetic algorithm based on the virus theory of evolution (VE-GA), which has two types of populations: host population and virus population. The VE-GA is composed of genetic operators and virus operators such as reverse transcription and incorporation. The reverse transcription operator transcribes virus genes on the chromosome of host individual and the incorporation operator creates new genotype of virus from host individual. These operators by virus population make it possible to transmit segment of DNA between individuals in the host population. Therefore, the VE-GA realizes not only vertical but also horizontal propagation of genetic information. Further, the VE-GA is applied to the traveling salesman problem in order to show the effectiveness. 20 refs., 10 figs., 3 tabs.

  16. Performance analysis of the partial use of a local optimization operator on the genetic algorithm for the Travelling Salesman Problem

    Directory of Open Access Journals (Sweden)

    Milan Djordjevic

    2012-01-01

    Full Text Available Background: The Travelling Salesman Problem is an NP-hard problem in combinatorial optimization with a number of practical implications. There are many heuristic algorithms and exact methods for solving the problem. Objectives: In this paper we study the influence of hybridization of a genetic algorithm with a local optimizer on solving instances of the Travelling Salesman Problem. Methods/ Approach: Our algorithm uses hybridization that occurs at various percentages of generations of a genetic algorithm. Moreover, we have also studied at which generations to apply the hybridization and hence applied it at random generations, at the initial generations, and at the last ones. Results: We tested our algorithm on instances with sizes ranging from 76 to 439 cities. On the one hand, the less frequent application of hybridization decreased the average running time of the algorithm from 14.62 sec to 2.78 sec at 100% and 10% hybridization respectively, while on the other hand, the quality of the solution on average deteriorated only from 0.21% till 1.40% worse than the optimal solution. Conclusions: In the paper we have shown that even a small hybridization substantially improves the quality of the result. Moreover, the hybridization in fact does not deteriorate the running time too much. Finally, our experiments show that the best results are obtained when hybridization occurs in the last generations of the genetic algorithm.

  17. New formulation and branch-and-cut algorithm for the pickup and delivery traveling salesman problem with multiple stacks: new formulation and branch-and-cut algorithm

    NARCIS (Netherlands)

    Sampaio Oliveira, A.H.; Urrutia, S.

    2017-01-01

    In this paper, we consider the pickup and delivery traveling salesman problem with multiple stacks in which a single vehicle must serve a set of customer requests defined by a pair of pickup and delivery destinations of an item. The vehicle contains a fixed number of stacks, where each item is

  18. Solving the Traveling Salesman Problem Based on The Genetic Reactive Bone Route Algorithm whit Ant Colony System

    Directory of Open Access Journals (Sweden)

    Majid Yousefikhoshbakht

    2016-07-01

    Full Text Available The TSP is considered one of the most well-known combinatorial optimization tasks and researchers have paid so much attention to the TSP for many years. In this problem, a salesman starts to move from an arbitrary place called depot and after visits all of the nodes, finally comes back to the depot. The objective is to minimize the total distance traveled by the salesman.  Because this problem is a non-deterministic polynomial (NP-hard problem in nature, a hybrid meta-heuristic algorithm called REACSGA is used for solving the TSP. In REACSGA, a reactive bone route algorithm that uses the ant colony system (ACS for generating initial diversified solutions and the genetic algorithm (GA as an improved procedure are applied. Since the performance of the Metaheuristic algorithms is significantly influenced by their parameters, Taguchi Method is used to set the parameters of the proposed algorithm. The proposed algorithm is tested on several standard instances involving 24 to 318 nodes from the literature. The computational result shows that the results of the proposed algorithm are competitive with other metaheuristic algorithms for solving the TSP in terms of better quality of solution and computational time respectively. In addition, the proposed REACSGA is significantly efficient and finds closely the best known solutions for most of the instances in which thirteen best known solutions are also found.

  19. Solusi Optimal Model Optimisasi Robust Untuk Masalah Traveling Salesman Dengan Ketidaktentuan Kotak Dan Pendekatan Metode Branch And Bound

    Directory of Open Access Journals (Sweden)

    Poppy Amriyati

    2015-12-01

    Full Text Available Traveling Salesman Problem (TSP merupakan teknik pencarian rute yang dimulai dari satu titik awal, setiap kota harus dikunjungi sekali dan kemudian kembali ke tempat asal sehingga total jarak atau waktu perjalanan adalah minimum. Untuk mengatasi kedakpastian jarak atau waktu perjalanan, maka perlu dilakukan pengembangan model TSP. Salah satu bidang Optimisasi yang mampu menyelesaikan permasalahan terkait ketidakpastian adalah Optimisasi Robust. Dalam makalah ini dibahas mengenai penerapan Optimisasi Robust pada TSP (RTSP menggunakan pendekatan Box Uncertainty dan diselesaikan dengan menggunakan Metode Branch and Bound. Disajikan simulasi numerik pada software aplikasi Maple untuk beberapa kasus nyata terkait penerapan Optimisasi RTSP , seperti masalah manajemen konstruksi, penentuan jarak tempuh kota di Pulau Jawa, dan Penentuan Rute Mandiri Fun Run.

  20. An improved self-adaptive ant colony algorithm based on genetic strategy for the traveling salesman problem

    Science.gov (United States)

    Wang, Pan; Zhang, Yi; Yan, Dong

    2018-05-01

    Ant Colony Algorithm (ACA) is a powerful and effective algorithm for solving the combination optimization problem. Moreover, it was successfully used in traveling salesman problem (TSP). But it is easy to prematurely converge to the non-global optimal solution and the calculation time is too long. To overcome those shortcomings, a new method is presented-An improved self-adaptive Ant Colony Algorithm based on genetic strategy. The proposed method adopts adaptive strategy to adjust the parameters dynamically. And new crossover operation and inversion operation in genetic strategy was used in this method. We also make an experiment using the well-known data in TSPLIB. The experiment results show that the performance of the proposed method is better than the basic Ant Colony Algorithm and some improved ACA in both the result and the convergence time. The numerical results obtained also show that the proposed optimization method can achieve results close to the theoretical best known solutions at present.

  1. The Multi-commodity One-to-one Pickup-and-delivery Traveling Salesman Problem with Path Duration Limits

    DEFF Research Database (Denmark)

    Plum, Christian Edinger Munk; Pisinger, David; Salazar-González, Juan-José

    2012-01-01

    The design of container shipping networks is an important real world problem, with assets and operational costs in billions of dollars. To guide the optimal deployment of the ships, a single vessel roundtrip is considered by minimizing operational costs and flowing the best paying cargo under...... commercial constraints. Inspiration for formulation and solution method is taken from the rich research done within pickup and delivery problems. The problem, the multicommodity one-toone pickup and delivery traveling salesman problem with path duration limits is, to the best of out knowledge, considered...... for the first time. An arc flow and a path flow model are presented. A Branch and Cut and Price solution method is proposed and implemented....

  2. The application of ant colony optimization in the solution of 3D traveling salesman problem on a sphere

    Directory of Open Access Journals (Sweden)

    Hüseyin Eldem

    2017-08-01

    Full Text Available Traveling Salesman Problem (TSP is a problem in combinatorial optimization that should be solved by a salesperson who has to travel all cities at the minimum cost (minimum route and return to the starting city (node. Todays, to resolve the minimum cost of this problem, many optimization algorithms have been used. The major ones are these metaheuristic algorithms. In this study, one of the metaheuristic methods, Ant Colony Optimization (ACO method (Max-Min Ant System – MMAS, was used to solve the Non-Euclidean TSP, which consisted of sets of different count points coincidentally located on the surface of a sphere. In this study seven point sets were used which have different point count. The performance of the MMAS method solving Non-Euclidean TSP problem was demonstrated by different experiments. Also, the results produced by ACO are compared with Discrete Cuckoo Search Algorithm (DCS and Genetic Algorithm (GA that are in the literature. The experiments for TSP on a sphere, show that ACO’s average results were better than the GA’s average results and also best results of ACO successful than the DCS.

  3. The modification of hybrid method of ant colony optimization, particle swarm optimization and 3-OPT algorithm in traveling salesman problem

    Science.gov (United States)

    Hertono, G. F.; Ubadah; Handari, B. D.

    2018-03-01

    The traveling salesman problem (TSP) is a famous problem in finding the shortest tour to visit every vertex exactly once, except the first vertex, given a set of vertices. This paper discusses three modification methods to solve TSP by combining Ant Colony Optimization (ACO), Particle Swarm Optimization (PSO) and 3-Opt Algorithm. The ACO is used to find the solution of TSP, in which the PSO is implemented to find the best value of parameters α and β that are used in ACO.In order to reduce the total of tour length from the feasible solution obtained by ACO, then the 3-Opt will be used. In the first modification, the 3-Opt is used to reduce the total tour length from the feasible solutions obtained at each iteration, meanwhile, as the second modification, 3-Opt is used to reduce the total tour length from the entire solution obtained at every iteration. In the third modification, 3-Opt is used to reduce the total tour length from different solutions obtained at each iteration. Results are tested using 6 benchmark problems taken from TSPLIB by calculating the relative error to the best known solution as well as the running time. Among those modifications, only the second and third modification give satisfactory results except the second one needs more execution time compare to the third modifications.

  4. An Investigation of Starting Point Preferences in Human Performance on Traveling Salesman Problems

    Science.gov (United States)

    MacGregor, James N.

    2014-01-01

    Previous studies have shown that people start traveling sales problem tours significantly more often from boundary than from interior nodes. There are a number of possible reasons for such a tendency: first, it may arise as a direct result of the processes involved in tour construction; second, boundary points may be perceptually more salient than…

  5. An Adaptive Evolutionary Algorithm for Traveling Salesman Problem with Precedence Constraints

    Directory of Open Access Journals (Sweden)

    Jinmo Sung

    2014-01-01

    Full Text Available Traveling sales man problem with precedence constraints is one of the most notorious problems in terms of the efficiency of its solution approach, even though it has very wide range of industrial applications. We propose a new evolutionary algorithm to efficiently obtain good solutions by improving the search process. Our genetic operators guarantee the feasibility of solutions over the generations of population, which significantly improves the computational efficiency even when it is combined with our flexible adaptive searching strategy. The efficiency of the algorithm is investigated by computational experiments.

  6. Theoretical analysis of two ACO approaches for the traveling salesman problem

    DEFF Research Database (Denmark)

    Kötzing, Timo; Neumann, Frank; Röglin, Heiko

    2012-01-01

    Bioinspired algorithms, such as evolutionary algorithms and ant colony optimization, are widely used for different combinatorial optimization problems. These algorithms rely heavily on the use of randomness and are hard to understand from a theoretical point of view. This paper contributes...... to the theoretical analysis of ant colony optimization and studies this type of algorithm on one of the most prominent combinatorial optimization problems, namely the traveling salesperson problem (TSP). We present a new construction graph and show that it has a stronger local property than one commonly used...... for constructing solutions of the TSP. The rigorous runtime analysis for two ant colony optimization algorithms, based on these two construction procedures, shows that they lead to good approximation in expected polynomial time on random instances. Furthermore, we point out in which situations our algorithms get...

  7. ON THE USE OF LYTLE’S ALGORITHM FOR SOLVING TRAVELING SALESMAN PROBLEM AT DEVELOPING SUBURBAN ROUTE

    Directory of Open Access Journals (Sweden)

    S. Kantsedal

    2012-01-01

    Full Text Available Lytle’s algorithm is described as proposed for an accurate solution of the salesman Problem. Statistical characteristics of solution duration with lytle’s algorithm of some problems and of their modifications are specified. On the basis of the results obtained the limits for the algorithm practical specification in the preparation of the route network are given.

  8. Implementasi Algoritma Best-First Search (BeFS pada Penyelesaian Traveling Salesman Problem (TSP (Studi Kasus: Perjalanan Wisata Di Kota Yogyakarta

    Directory of Open Access Journals (Sweden)

    Muchammad Abrori

    2015-10-01

    Full Text Available Yogyakarta offers many tourist attractions, from nature based tourism, culinary tourism until cultural tourism. With so many tourist attractions offered by Yogyakarta, tourist often finds it difficult to arrange their travel schedule (from choosing which tourist attractions to be visited until choosing which route tourist should takes to maximize their vacation time. Therefore, it’s required to have a way to determine the shortest tour route so tourist can make their tour in the Yogyakarta effective. This problem can be categorized as Traveling Salesman Problem (TSP case. There are a lot of methods can be used to find the shortest route in Travelling Salesman Problems (TSP case. To solve the problem, which is to find the shortest tour route in Yogyakarta, Algorithm Best-First Travelling will be used in this undergraduate thesis. The implementation of Algorithm Best-First Search to find the shortest tour route in Yogyakarta can be used to produce a solution for tourist to choose the shortest tour package and decide which route they should take. The premium tour package produces tour route from Adi Sucipto Airport-Gembira Loka Zoo- Purawisata-N’dalem Gamelan Hotel-Yogyakarta Palace-Benteng Vredeburg Museum-Taman Pintar-Tamansari-Adi Sucipto Airport with distance covered 20.297 meter. The middle tour package produces tour route from Tugu railway station-Benteng Vredeburg Museum- Taman Pintar-Yogyakarta Palace-Mawar Asri Hotel-Tamansari-Purawisata-Gembira Loka Zoo-Tugu railway station with distance covered 11.772 meter. The economy tour package produces tour route from Giwangan bus station- Gembira Loka zoo-Purawisata-Yogyakarta Palace-Mitra Hotel-Benteng Vredeburg Museum-Taman Pintar-Tamansari-Giwangan bus station with distance covered 14.037 meter.

  9. Heuristic Solution Approaches to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

    This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries in ...... are developed for the problem and used with each of the heuristics. Finally some computational results are given along with lower bounds on the objective value....

  10. Heuristic Solution Approaches to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann

    2006-01-01

    This paper introduces the Double Travelling Salesman Problem with Multiple Stacks and presents a three different metaheuristic approaches to its solution. The Double Travelling Salesman Problem with Multiple Stacks is concerned with finding the shortest route performing pickups and deliveries in ...... are developed for the problem and used with each of the heuristics. Finally some computational results are given along with lower bounds on the objective value....

  11. Multi-Objective Ant Colony Optimization Based on the Physarum-Inspired Mathematical Model for Bi-Objective Traveling Salesman Problems.

    Directory of Open Access Journals (Sweden)

    Zili Zhang

    Full Text Available Bi-objective Traveling Salesman Problem (bTSP is an important field in the operations research, its solutions can be widely applied in the real world. Many researches of Multi-objective Ant Colony Optimization (MOACOs have been proposed to solve bTSPs. However, most of MOACOs suffer premature convergence. This paper proposes an optimization strategy for MOACOs by optimizing the initialization of pheromone matrix with the prior knowledge of Physarum-inspired Mathematical Model (PMM. PMM can find the shortest route between two nodes based on the positive feedback mechanism. The optimized algorithms, named as iPM-MOACOs, can enhance the pheromone in the short paths and promote the search ability of ants. A series of experiments are conducted and experimental results show that the proposed strategy can achieve a better compromise solution than the original MOACOs for solving bTSPs.

  12. Improvement of algorithm using Kohonen`s self-organizing feature map for the traveling salesman problem; Kohonen jiko soshikika tokucho mappu wo mochiita ukai serusuman mondai kaiho no kairyo

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, K.; Tokutaka, H.; Tanaka, H.; Kishida, S. [Tottori Univ., Tottori (Japan); Oshima, Y. [Mita Industrial Co. Ltd., Osaka (Japan)

    1996-02-20

    Traveling salesman problem (TSP) is one of the combinatorial optimization problems. The solution of this problem is to seek the way of how to visit every city only once within the shortest traveling distance. The solutions of this problem are studied a lot hitherto since they are the index for observing the basic properties of optimization algorithm. The method of Angeniol using the elf-organizing feature map is greatly forceful from the viewpoint of its short calculating time. In this study, regarding the algorithm of Angeniol, the conditions of obtaining the shortest tour length within shorter time are examined. Namely, a half of calculating time is reduced by changing Angeniol method into the method of making the node create after the searches of M cities. Additionally, the calculating time for unchanged tour length is reduced to one fourth by adding an inertia item in accordance with the variation of the number of total nodes. 14 refs., 8 figs.

  13. Metaheurísticas híbridas para resolução do problema do caixeiro viajante com coleta de prêmios Hybrid metaheuristics for solve the prize collecting traveling salesman problem

    Directory of Open Access Journals (Sweden)

    Antonio Augusto Chaves

    2007-08-01

    Full Text Available O Problema do Caixeiro Viajante com Coleta de Prêmios (PCVCP pode ser associado a um caixeiro que coleta um prêmio em cada cidade visitada e paga uma penalidade para cada cidade não visitada, com um custo de deslocamento entre as cidades. O problema encontra-se em minimizar o somatório dos custos da viagem e penalidades, enquanto inclui na sua rota um número suficiente de cidades que lhe permita coletar um prêmio mínimo preestabelecido. Este trabalho contribui com o desenvolvimento de metaheurísticas híbridas para o PCVCP, baseadas em GRASP e métodos de busca em vizinhança variável (VNS/VND para solucionar aproximadamente o PCVCP. De forma a validar as soluções obtidas, propõe-se uma formulação matemática a ser resolvida por um solver comercial, objetivando encontrar a solução ótima para o problema, sendo este solver aplicado a problemas de pequeno porte. Resultados computacionais demonstram a eficiência da abordagem híbrida proposta, tanto em relação à qualidade da solução final obtida quanto em relação ao tempo de execução.The Prize Collecting Traveling Salesman Problem (PCTSP can be associated to a salesman who collects a prize in each city visited and pays a penalty for each city not visited, with travel costs among the cities. The objective is to minimize the sum of the travel costs and penalties, including in the tour enough number of cities that allow collecting a minimum prize. This paper contributes with the development of a hybrid metaheuristic to PCTSP, based on GRASP and search methods in variable neighborhood (VNS/VND to solve PCTSP approximately. In order to validate the obtained solutions, we proposed a mathematical formulation to be solved by a commercial solver to find the best solution to the problem, being this solver applied to small problems. Computational results demonstrate the efficiency of the proposed method, as much in relation to the quality of the obtained final solution as in relation

  14. An Exact Method for the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Lusby, Richard Martin; Larsen, Jesper; Ehrgott, Matthias

    2010-01-01

    The double travelling salesman problem with multiple stacks (DTSPMS) is a pickup and delivery problem in which all pickups must be completed before any deliveries can be made. The problem originates from a real-life application where a 40 foot container (configured as 3 columns of 11 rows) is used...

  15. An Exact Method for the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Larsen, Jesper; Lusby, Richard Martin; Ehrgott, Matthias

    The double travelling salesman problem with multiple stacks (DTSPMS) is a pickup and delivery problem in which all pickups must be completed before any deliveries can be made. The problem originates from a real-life application where a 40 foot container (configured as 3 columns of 11 rows) is used...

  16. Fifth-order amplitude equation for traveling waves in isothermal double diffusive convection

    International Nuclear Information System (INIS)

    Mendoza, S.; Becerril, R.

    2009-01-01

    Third-order amplitude equations for isothermal double diffusive convection are known to hold the tricritical condition all along the oscillatory branch, predicting that stable traveling waves exist Only at the onset of the instability. In order to properly describe stable traveling waves, we perform a fifth-order calculation and present explicitly the corresponding amplitude equation.

  17. Exact Solutions to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann; Archetti, Claudia; Madsen, Oli B.G.

    In the Double Travelling Salesman Problem with Multiple Stacks (DTSPMS) a set of orders is given, each one requiring transportation of one item from a customer in a pickup region to a customer in a delivery region. The vehicle available for the transportation in each region carries a container....... We present different modelling approaches to solving the DTSPMS to optimality and use the solutions obtained to evaluate the quality of previously obtained heuristic solutions....

  18. Randomised, Double Blind, Placebo-Controlled Trial of Echinacea Supplementation in Air Travellers

    Directory of Open Access Journals (Sweden)

    E. Tiralongo

    2012-01-01

    Full Text Available Objective. To identify whether a standardised Echinacea formulation is effective in the prevention of respiratory and other symptoms associated with long-haul flights. Methods. 175 adults participated in a randomised, double-blind placebo-controlled trial travelling back from Australia to America, Europe, or Africa for a period of 1–5 weeks on commercial flights via economy class. Participants took Echinacea (root extract, standardised to 4.4 mg alkylamides or placebo tablets. Participants were surveyed before, immediately after travel, and at 4 weeks after travel regarding upper respiratory symptoms and travel-related quality of life. Results. Respiratory symptoms for both groups increased significantly during travel (P<0.0005. However, the Echinacea group had borderline significantly lower respiratory symptom scores compared to placebo (P=0.05 during travel. Conclusions. Supplementation with standardised Echinacea tablets, if taken before and during travel, may have preventive effects against the development of respiratory symptoms during travel involving long-haul flights.

  19. Travelling

    African Journals Online (AJOL)

    homes very soon becomes a misplaced sentiment. However well planned a journey may be and how- ever important and tiring the attendances at meet- ings are, at some stage of every day the traveller finds himself in an hotel room and loneliness starts closing in from all four walls. No matter how luxu- rious the hotel may ...

  20. Field theory of a terahertz staggered double-grating arrays waveguide Cerenkov traveling wave amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wenqiu; He, Fangming [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Zicheng; Luo, Jirun; Zhao, Ding; Liu, Qinglun [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-04-15

    Based on a rectilinear sheet electron beam propagating through the tunnel of a staggered double-grating arrays waveguide (SDGAW) slow-wave structure (SWS), a three dimensional field theory for describing the modes and the beam-wave interaction is presented, in which the higher order terms inside the grooves are retained. The fields' distribution and the conductivity losses are also calculated utilizing the theoretical model. With the optimized parameters of the SWS and the electron beam, a 1 THz SDGAW Cerenkov traveling wave amplifier may obtain a moderate net gain (the peak gain is 12.7 dB/cm) and an ultra 3 dB wideband (0.19 THz) considering the serious Ohmic losses. The theoretical results have been compared with those calculated by 3D HFSS code and CST STUDIO particle-in-cell simulations.

  1. Comparison of neural networks for solving the travelling salesman problem

    NARCIS (Netherlands)

    Maire, La B.F.J.; Mladenov, V.M.

    2012-01-01

    The TSP deals with finding a shortest path through a number of cities. This seemingly simple problem is hard to solve because of the amount of possible solutions. Which is why methods that give a good suboptimal solution in a reasonable time are generally used. In this paper three methods were

  2. Optimization Approaches for the Traveling Salesman Problem with Drone

    NARCIS (Netherlands)

    N.A.H. Agatz (Niels); P.C. Bouman (Paul); M.E. Schmidt (Marie)

    2016-01-01

    textabstractThe fast and cost-efficient home delivery of goods ordered online is logistically challenging. Many companies are looking for new ways to cross the last-mile to their customers. One technology-enabled opportunity that recently has received much at- tention is the use of a drone to

  3. Arthur Miller's Death of a Salesman

    OpenAIRE

    Apolinário, Valdemar dos Passos

    2001-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em Letras/Inglês e Literatura Correspondente Investiga como as questões político-sociais atingiram as personagens de Arthur Miller na peça Death of a Salesman, contribuindo para moldar suas personalidades e determinando o seu destino. Mostra que, para Arthur Miller, Benjamin Franklin foi a principal fonte de inspiração no seu retrato das preocupações políticas, da c...

  4. Application of supernetworks in modeling activity-travel behaviour

    NARCIS (Netherlands)

    Liao, F.; Arentze, T.A.; Timmermans, H.J.P.

    2011-01-01

    Network representation and optimization has for long been applied to address vast engineering and scientific problems. Examples are originated from the Seven Bridges of Konigsberg, to a variety of classic P and NP-hard problems such minimum spanning tree, shortest path, and traveling salesman

  5. Travelers' diarrhea.

    Science.gov (United States)

    Barrett-Connor, E

    1973-03-01

    On the average, one-fourth of North Americans visiting developing countries experience a self-limited diarrheal illness that interferes with holiday or business activities. Recent work suggests that these episodes are caused by a small inoculum of enteropathogenic Escherichia coli which are common in the country visited and rare in the country of origin. Neither antimicrobial treatment nor anti-diarrheal agents have proven benefit once the illness has begun. Despite its frequent use, iodochlorhydroxyquin has not been shown in double blind studies to be effective as a preventive agent, and may be dangerous. The status of furazolidone for prevention of tourist diarrhea is questionable. Both neomycin sulfate and phythalylsulfathiazole have demonstrated efficacy as chemoprophylactics in Mexico. However, their use should be restricted to limited types of travel and travelers. General admonitions concerning avoidance of certain ingestibles are recommended; despite questionable value in preventing travelers' diarrhea such precautions may prevent more serious gastrointestinal illness.

  6. Atovaquone-proguanil versus chloroquine-proguanil for malaria prophylaxis in non-immune travellers: a randomised, double-blind study. Malarone International Study Team.

    Science.gov (United States)

    Høgh, B; Clarke, P D; Camus, D; Nothdurft, H D; Overbosch, D; Günther, M; Joubert, I; Kain, K C; Shaw, D; Roskell, N S; Chulay, J D

    2000-12-02

    Chloroquine plus proguanil is widely used for malaria chemoprophylaxis despite low effectiveness in areas where multidrug-resistant malaria occurs. Studies have shown that atovaquone and proguanil hydrochloride is safe and effective for prevention of falciparum malaria in lifelong residents of malaria-endemic countries, but little is known about non-immune travellers. In a double-blind equivalence trial, 1083 participants travelling to a malaria-endemic area were randomly assigned to two treatment groups: atovaquone-proguanil plus placebos for chloroquine and proguanil, or chloroquine, proguanil, and placebo for atovaquone-proguanil. Follow-up was by telephone 7 and 60 days after travel and at a clinic at 28 days. Serum samples were tested for antibodies to a malaria circumsporozoite protein. Blood and serum samples of participants with a potential malaria diagnosis were tested in a reference laboratory. 7 days after travel, at least one adverse event was reported by 311 (61%) of 511 participants who received atovaquone-proguanil and 329 (64%) of 511 who received chloroquine-proguanil. People receiving atovaquone-proguanil had a lower frequency of treatment-related gastrointestinal adverse events (59 [12%] vs 100 [20%], p=0.001), and of treatment-related adverse events of moderate or severe intensity (37 [7%] vs 56 [11%], p=0.05). There were fewer treatment-related adverse events that caused prophylaxis to be discontinued in the atovaquone-proguanil group than in the chloroquine-proguanil group (one [0.2%] vs ten [2%], p=0.015). Overall the two preparations were similarly tolerated. However, significantly fewer adverse gastrointestinal events were observed in the atovaquone-proguanil group in than in the chloroquine-proguanil group.

  7. Novel Double-Hit Model of Radiation and Hyperoxia-Induced Oxidative Cell Damage Relevant to Space Travel

    Directory of Open Access Journals (Sweden)

    Ralph A. Pietrofesa

    2016-06-01

    Full Text Available Spaceflight occasionally requires multiple extravehicular activities (EVA that potentially subject astronauts to repeated changes in ambient oxygen superimposed on those of space radiation exposure. We thus developed a novel in vitro model system to test lung cell damage following repeated exposure to radiation and hyperoxia. Non-tumorigenic murine alveolar type II epithelial cells (C10 were exposed to >95% O2 for 8 h only (O2, 0.25 Gy ionizing γ-radiation (IR only, or a double-hit combination of both challenges (O2 + IR followed by 16 h of normoxia (ambient air containing 21% O2 and 5% CO2 (1 cycle = 24 h, 2 cycles = 48 h. Cell survival, DNA damage, apoptosis, and indicators of oxidative stress were evaluated after 1 and 2 cycles of exposure. We observed a significant (p < 0.05 decrease in cell survival across all challenge conditions along with an increase in DNA damage, determined by Comet analysis and H2AX phosphorylation, and apoptosis, determined by Annexin-V staining, relative to cells unexposed to hyperoxia or radiation. DNA damage (GADD45α and cleaved-PARP, apoptotic (cleaved caspase-3 and BAX, and antioxidant (HO-1 and Nqo1 proteins were increased following radiation and hyperoxia exposure after 1 and 2 cycles of exposure. Importantly, exposure to combination challenge O2 + IR exacerbated cell death and DNA damage compared to individual exposures O2 or IR alone. Additionally levels of cell cycle proteins phospho-p53 and p21 were significantly increased, while levels of CDK1 and Cyclin B1 were decreased at both time points for all exposure groups. Similarly, proteins involved in cell cycle arrest was more profoundly changed with the combination challenges as compared to each stressor alone. These results correlate with a significant 4- to 6-fold increase in the ratio of cells in G2/G1 after 2 cycles of exposure to hyperoxic conditions. We have characterized a novel in vitro model of double-hit, low-level radiation and hyperoxia

  8. Ozone-induced dissociation on a traveling wave high-resolution mass spectrometer for determination of double-bond position in lipids.

    Science.gov (United States)

    Vu, Ngoc; Brown, Jeffery; Giles, Kevin; Zhang, Qibin

    2017-09-15

    The position of C=C within fatty acyl chains affects the biological function of lipids. Ozone-induced dissociation mass spectrometry (OzID-MS) has great potential in determination of lipid double-bond position, but has generally been implemented on low-resolution ion trap mass spectrometers. In addition, most of the OzID-MS experiments carried out so far were focused on the sodiated adducts of lipids; fragmentation of the most commonly observed protonated ions generated in LC/MS-based lipidomics workflow has been less explored. Ozone generated in line from an ozone generator was connected to the trap and transfer gas supply line of a Synapt G2 high-resolution mass spectrometer. Protonated ions of different phosphatidylcholines (PC) were generated by electrospray ionization through direct infusion. Different parameters, including traveling wave height and velocity, trap entrance and DC potential, were adjusted to maximize the OzID efficiency. sn-positional isomers and cis/trans isomers of lipids were compared for their reactivity with ozone. Traveling wave height and velocity were tuned to prolong the encounter time between lipid ions and ozone, and resulted in improved OzID efficiency, as did increasing trapping region DC and entrance potential. Under optimized settings, at least 1000 times enhancement in OzID efficiency was achieved compared to that under default settings for monounsaturated PC standards. Monounsaturated C=C in the sn-2 PC isomer reacted faster with ozone than the sn-1 isomer. Similarly, the C=C in trans PC reacted faster than in cis PC. This is the first implementation of OzID in the trap and transfer region of a traveling wave enabled high-resolution mass spectrometer. The OzID reaction efficiency is significantly improved by slowing down ions in the trap region for their prolonged interaction with ozone. This will facilitate application of high-resolution OzID-MS in lipidomics. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Solving the equality generalized traveling salesman problem using the Lin–Kernighan–Helsgaun Algorithm

    DEFF Research Database (Denmark)

    Helsgaun, Keld

    2015-01-01

    instances in a well-known library of benchmark instances, GTSPLIB, could be solved to optimality in a reasonable time. In addition, it was possible to solve a series of new very-large-scale instances with up to 17,180 clusters and 85,900 vertices. Optima for these instances are not known...... be downloaded in source code....

  10. An Improved Routing Optimization Algorithm Based on Travelling Salesman Problem for Social Networks

    Directory of Open Access Journals (Sweden)

    Naixue Xiong

    2017-06-01

    Full Text Available A social network is a social structure, which is organized by the relationships or interactions between individuals or groups. Humans link the physical network with social network, and the services in the social world are based on data and analysis, which directly influence decision making in the physical network. In this paper, we focus on a routing optimization algorithm, which solves a well-known and popular problem. Ant colony algorithm is proposed to solve this problem effectively, but random selection strategy of the traditional algorithm causes evolution speed to be slow. Meanwhile, positive feedback and distributed computing model make the algorithm quickly converge. Therefore, how to improve convergence speed and search ability of algorithm is the focus of the current research. The paper proposes the improved scheme. Considering the difficulty about searching for next better city, new parameters are introduced to improve probability of selection, and delay convergence speed of algorithm. To avoid the shortest path being submerged, and improve sensitive speed of finding the shortest path, it updates pheromone regulation formula. The results show that the improved algorithm can effectively improve convergence speed and search ability for achieving higher accuracy and optimal results.

  11. Travel expenses

    OpenAIRE

    Pištěková, Petra

    2014-01-01

    The thesis "Travel expenses" is dedicated to the travel expenses according to Czech legislation. The aim is to describe the travel reimbursement and to analyze the providing of compensation travel expenses on example of the elementary art school Zruč nad Sázavou. The purpose of this analysis is primarily to find an optimal solution to the problem of determining the place of regular workplace for the travel expenses. The theoretical part focuses on the identification and definition of all prin...

  12. Travel medicine

    Science.gov (United States)

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Abstract Objective To define the practice of travel medicine, provide the basics of a comprehensive pretravel consultation for international travelers, and assist in identifying patients who might require referral to travel medicine professionals. Sources of information Guidelines and recommendations on travel medicine and travel-related illnesses by national and international travel health authorities were reviewed. MEDLINE and EMBASE searches for related literature were also performed. Main message Travel medicine is a highly dynamic specialty that focuses on pretravel preventive care. A comprehensive risk assessment for each individual traveler is essential in order to accurately evaluate traveler-, itinerary-, and destination-specific risks, and to advise on the most appropriate risk management interventions to promote health and prevent adverse health outcomes during travel. Vaccinations might also be required and should be personalized according to the individual traveler’s immunization history, travel itinerary, and the amount of time available before departure. Conclusion A traveler’s health and safety depends on a practitioner’s level of expertise in providing pretravel counseling and vaccinations, if required. Those who advise travelers are encouraged to be aware of the extent of this responsibility and to refer all high-risk travelers to travel medicine professionals whenever possible. PMID:25500599

  13. Connected Traveler

    Energy Technology Data Exchange (ETDEWEB)

    2016-06-01

    The Connected Traveler framework seeks to boost the energy efficiency of personal travel and the overall transportation system by maximizing the accuracy of predicted traveler behavior in response to real-time feedback and incentives. It is anticipated that this approach will establish a feedback loop that 'learns' traveler preferences and customizes incentives to meet or exceed energy efficiency targets by empowering individual travelers with information needed to make energy-efficient choices and reducing the complexity required to validate transportation system energy savings. This handout provides an overview of NREL's Connected Traveler project, including graphics, milestones, and contact information.

  14. Randomised, double-blind, safety and efficacy of a killed oral vaccine for enterotoxigenic E. Coli diarrhoea of travellers to Guatemala and Mexico.

    Science.gov (United States)

    Sack, David A; Shimko, Janet; Torres, Olga; Bourgeois, August L; Francia, Domingo Sanchez; Gustafsson, Björn; Kärnell, Anders; Nyquist, Iréne; Svennerholm, Ann-Mari

    2007-05-30

    We tested the efficacy of a killed oral vaccine for enterotoxigenic Escherichia coli (ETEC) diarrhoea to determine if two doses of vaccine with colonization factor antigens (CF) and cholera B subunit would protect against ETEC diarrhoea of travellers. Six hundred seventy-two healthy travellers going to Mexico or Guatemala were studied in a prospective, randomised, placebo-controlled trial. The primary outcome was a vaccine preventable outcome (VPO), defined as an episode of ETEC diarrhoea with an ETEC organism producing heat labile toxin (LT) or CF homologous with the vaccine, without other known causes. The vaccine was safe and stimulated anti-heat labile toxin antibodies. There was a significant decrease in more severe VPO episodes (PE=77%, p=0.039) as defined by symptoms that interfered with daily activities or more than five loose stools in a day, although the total number of VPO events did not differ significantly in the vaccine and placebo groups. We conclude that the new oral ETEC vaccine reduces the rate of more severe episodes of traveller's diarrhoea (TD) due to VPO-ETEC, but it did not reduce the overall rate of ETEC diarrhoea or of travellers' diarrhoea due to other causes.

  15. Travel Overview

    Science.gov (United States)

    Search the Division of Finance site DOF State of Alaska Finance Home Content Area Accounting Charge Cards Top Department of Administration logo Alaska Department of Administration Division of Finance Search You are here Administration / Finance / Travel Travel The Department of Administration administers the

  16. Travellers' diarrhoea.

    Science.gov (United States)

    Ericsson, Charles D

    2003-02-01

    Risk of travellers' diarrhoea is about 7% in developed countries and 20-50% in the developing world. Options for prevention include education and chemoprophylaxis. Vaccination is a promising but incomplete option. Achieving behaviour modification of food and water choices among tourists is difficult. Bismuth subsalicylate (BSS)-containing compounds are about 62% effective in the prevention of travellers' diarrhoea. Antibiotics are about 84% effective in preventing travellers' diarrhoea. Routine prophylaxis of travellers' diarrhoea, especially with antibiotics, should be discouraged. Oral rehydration is generally important in the treatment of diarrhoea, but travellers' diarrhoea is only infrequently dehydrating in adults. The addition of oral rehydration solutions confers no additional benefit to loperamide in the treatment of travellers' diarrhoea in adults. Presently, the most active of the antibiotics routinely available for treatment are members of the fluoroquinolone group. Antibiotics that are not absorbed such as aztreonam and a rifampicin-like agent, rifaximin, are both effective. The latter might become a therapy of choice once it is routinely available, due to predictably less adverse reactions with a non-absorbed antibiotic. Preliminary results with azithromycin look very promising. Less severe disease can be treated with a variety of non-antibiotic agents (e.g. BSS-containing compounds, loperamide and a calmodulin inhibitor, zaldaride). The combination of an antibiotic and loperamide is superior to treatment with either agent alone in a several studies and is arguably the treatment of choice for distressing travellers' diarrhoea.

  17. Travelers' Diarrhea

    Science.gov (United States)

    ... Safety Road Safety - 8 Steps MERS Health Advisory poster MERS Pictogram CDC Guide for Healthy Travel Website ... alcohol-based hand sanitizer. In general, it’s a good idea to keep your hands away from your ...

  18. Travelers' Health

    Science.gov (United States)

    ... 3, Avoid Nonessential Travel Health Infrastructure Breakdown in Venezuela May 15, 2018 More Alert Level 2, Practice ... Vision Using this Site Legal Link to Us Policies FOIA Accessibility Privacy No FEAR Act Inspector General ...

  19. Travelling Concepts

    DEFF Research Database (Denmark)

    Simonsen, Karen-Margrethe

    2013-01-01

    Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012......Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012...

  20. Travelers' Health: Rubella

    Science.gov (United States)

    ... Stamaril clinics Disease Directory Resources Resources for Travelers Adventure Travel Animal Safety Blood Clots Bug Bites Evite ... Minute Travel Long-Term Travel Mass Gatherings Medical Tourism Mental Health Motion Sickness Natural Disasters Pregnant Travelers ...

  1. 26 CFR 31.3402(j)-1 - Remuneration other than in cash for service performed by retail commission salesman.

    Science.gov (United States)

    2010-04-01

    ... performed by retail commission salesman. 31.3402(j)-1 Section 31.3402(j)-1 Internal Revenue INTERNAL REVENUE... EMPLOYMENT TAXES AND COLLECTION OF INCOME TAX AT SOURCE Collection of Income Tax at Source § 31.3402(j)-1.... (2) Section 3402(j) and this section are not applicable with respect to wages paid to the employee...

  2. Human travel and traveling bedbugs.

    Science.gov (United States)

    Delaunay, Pascal

    2012-12-01

    A dramatic increase of reported bedbug (Cimex lectularius and Cimex hemipterus) infestations has been observed worldwide over the past decade. Bedbug infestations have also been detected across a wide range of travel accommodations, regardless of their comfort and hygiene levels. Travelers are increasingly exposed to the risks of bedbug bites, infestation of personal belongings, and subsequent contamination of newly visited accommodations and their homes. We searched Medline publications via the PubMed database. National bedbug recommendations, textbooks, newspapers, and Centers for Disease Control websites were also searched manually. To detect infested sites, avoid or limit bedbug bites, and reduce the risk of contaminating one's belongings and home, bedbug biology and ecology must be understood. A detailed search of their most classic hiding niches is a key to finding adult bedbugs, nymphs, eggs, and feces or traces of blood from crushed bedbugs. Locally, bedbugs move by active displacement to feed (bite) during the night. Bed, mattress, sofa, and/or curtains are the most frequently infested places. If you find bedbugs, change your room or, even better, the hotel. Otherwise, travelers should follow recommendations for avoiding bedbugs and their bites during the night and apply certain simple rules to avoid infesting other sites or their home. Travelers exposed to bedbugs can minimize the risks of bites and infestation of their belongings, and must also do their civic duty to avoid contributing to the subsequent contamination of other hotels and, finally, home. © 2012 International Society of Travel Medicine.

  3. A relax and cut approach using the multi-commodity flow formulation for the traveling salesman problem

    Directory of Open Access Journals (Sweden)

    Makswell Seyiti Kawashima

    2015-01-01

    Full Text Available En este artículo nosotros exploramos una formulación de flujo multiproductos para el Problema del Agente Viajero Asimétrico (ATSP en la obtención de cotas duales de este problema. El procedimiento empleado es una variante del método relax and cut propuesto en la literatura que computa los multiplicadores lagrangianos asociados a las restricciones de eliminación de subrutas preservando la optimalidad de los multiplicadores asociados a las restricciones de asignación. Los resultados obtenidos con la experimentación computacional son alentadores y muestran que el algoritmo propuesto genera buenas cotas duales con un tiempo de ejecución bajo.

  4. Traveling questions

    DEFF Research Database (Denmark)

    Hoeyer, Klaus

    2016-01-01

    In this paper, I argue that uncertainty and nonknowledge, and not just research results, can be important vehicles of translation through which genetic research participation comes to affect the lives of research participants. Based on interviews with participants in a genetic research project, I....... Research questions, and not just results, may serve as a generative form of knowledge that can travel as fast as any answer....

  5. Travelers' Health: HIV Infection

    Science.gov (United States)

    ... Last-Minute Travel Long-Term Travel Mass Gatherings Medical Tourism Mental Health Motion Sickness Natural Disasters Pregnant Travelers ... for purposes of medical treatment (see Chapter 2, Medical Tourism ), the blood and blood products used in the ...

  6. International travel and vaccinations.

    OpenAIRE

    Rizvon, M K; Qazi, S; Ward, L A

    1999-01-01

    With the increase in global travel, no disease is beyond the reach of any population. Traveling patients should be advised to follow food and water precautions and encouraged to receive the recommended immunizations. Travel medicine plays a vital role not only in limiting the morbidity of travel-related illnesses but also in limiting the spread of diseases. This article addresses the common issues related to travel, reviews the care of the immunocompromised traveler, and updates the available...

  7. The Connected Traveler

    Energy Technology Data Exchange (ETDEWEB)

    Young, Stanley

    2017-04-24

    The Connected Traveler project is a multi-disciplinary undertaking that seeks to validate potential for transformative transportation system energy savings by incentivizing energy efficient travel behavior.

  8. Essential travel medicine

    CERN Document Server

    Zuckerman, Jane N; Leggat, Peter

    2015-01-01

    This 1st edition of Essential Travel Medicine provides an excellent concise introduction to the specialty of Travel Medicine. This core text will enable health care practitioners particularly those new to the clinical practice of Travel Medicine, to gain a fundamental understanding of the diverse and complex issues which can potentially affect the health of the many millions of people who undertake international travel. Jane N Zuckerman is joined by Gary W Brunette from CDC and Peter A Leggat from Australia as Editors. Leading international specialists in their fields have contributed authoritative chapters reflecting current knowledge to facilitate best clinical practice in the different aspects of travel medicine. The aim of Essential Travel Medicine is to provide a comprehensive guide to Travel Medicine as well as a fundamental knowledge base to support international undergraduate and postgraduate specialty training programmes in the discipline of Travel Medicine. The 1st edition of Essential Travel ...

  9. Travelling with HIV

    DEFF Research Database (Denmark)

    Nielsen, Ulla S; Jensen-Fangel, Søren; Pedersen, Gitte

    2014-01-01

    BACKGROUND: We aimed to describe travel patterns, extent of professional pre-travel advice and health problems encountered during travel among HIV-infected individuals. METHODS: During a six-month period a questionnaire was handed out to 2821 adult HIV-infected individuals attending any...... of the eight Danish medical HIV care centers. RESULTS: A total of 763 individuals responded. During the previous two years 49% had travelled outside Europe; 18% had travelled less and 30% were more cautious when choosing travel destination than before the HIV diagnosis. Pre-travel advice was sought by only 38......%, and travel insurance was taken out by 86%. However, 29%/74% did not inform the advisor/the insurance company about their HIV status. Nearly all patients on highly active antiretroviral therapy (HAART) were adherent, but 58% worried about carrying HIV-medicine and 19% tried to hide it. Only 19% experienced...

  10. End to End Travel

    Data.gov (United States)

    US Agency for International Development — E2 Solutions is a web based end-to-end travel management tool that includes paperless travel authorization and voucher document submissions, document approval...

  11. Traveling with Food Allergies

    Science.gov (United States)

    ... on traveling and dining out at restaurants with food allergies. Travel Tips for the U.S. and Other Countries Get information about medications and food labeling practices in select countries. Spam Control Text: ...

  12. HIV and travel.

    Science.gov (United States)

    Schuhwerk, M A; Richens, J; Zuckerman, Jane N

    2006-01-01

    There is a high demand for travel among HIV-positive individual. This demand arises partly from those who have benefited from advances in antiretroviral therapy as well as those with disease progression. The key to a successful and uneventful holiday lies in careful pre-trip planning, yet many patients fail to obtain advice before travelling. Travel advice for HIV patients is becoming increasingly specialized. In addition to advice on common travel-related infectious diseases, HIV-positive travellers are strongly advised to carry information with them and they need specific advice regarding country entry restrictions, HIV inclusive travel insurance, safety of travel vaccinations and highly active antiretroviral therapy-related issues. A wide range of relevant issues for the HIV-positive traveller are discussed in this review and useful websites can be found at the end.

  13. Traveling Safely with Medicines

    Science.gov (United States)

    ... Medications Safely My Medicine List How to Administer Traveling Safely with Medicines Planes, trains, cars – even boats ... your trip, ask your pharmacist about how to travel safely with your medicines. Make sure that you ...

  14. Travelers' Health: Leishmaniasis, Visceral

    Science.gov (United States)

    ... such as the United States reflects travel and immigration patterns. VL is uncommon in US travelers and ... whqlibdoc.who.int/trs/WHO_TRS_949_eng.pdf . Chapter 3 - Leishmaniasis, Cutaneous Chapter 3 - Leptospirosis File ...

  15. Traveling and Asthma

    Science.gov (United States)

    ... Videos for Educators Search English Español Traveling and Asthma KidsHealth / For Kids / Traveling and Asthma Print en ... pack it, too. How Can I Avoid My Asthma Triggers? Staying at a hotel Ask for a ...

  16. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    A method is described for generating a traveling wave laser pulse of almost unlimited energy content wherein a gain medium is pumped into a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  17. Travel, infection and immunity

    OpenAIRE

    Soonawala, Darius

    2016-01-01

    Preface: The content of this thesis is based on research that was conducted at the travel and vaccination clinic at Leiden University Medical Centre (LUMC). This clinic provides pre-travel care to the general population, and to special groups of travellers, such as patients who use immunosuppressants or who have chronic diseases. The clinic is closely connected to the department of Infectious Diseases at LUMC. The setting of a travel clinic within an academic medical hospital, provides unique...

  18. Travel, infection and immunity

    NARCIS (Netherlands)

    Soonawala, Darius

    2016-01-01

    Preface: The content of this thesis is based on research that was conducted at the travel and vaccination clinic at Leiden University Medical Centre (LUMC). This clinic provides pre-travel care to the general population, and to special groups of travellers, such as patients who use

  19. Travel Agent Course Outline.

    Science.gov (United States)

    British Columbia Dept. of Education, Victoria.

    Written for college entry-level travel agent training courses, this course outline can also be used for inservice training programs offered by travel agencies. The outline provides information on the work of a travel agent and gives clear statements on what learners must be able to do by the end of their training. Material is divided into eight…

  20. Modelling urban travel times

    NARCIS (Netherlands)

    Zheng, F.

    2011-01-01

    Urban travel times are intrinsically uncertain due to a lot of stochastic characteristics of traffic, especially at signalized intersections. A single travel time does not have much meaning and is not informative to drivers or traffic managers. The range of travel times is large such that certain

  1. Travel personae of American pleasure travelers

    DEFF Research Database (Denmark)

    Park, S.; Tussyadiah, Iis; Mazanec, J.A.

    2010-01-01

    Travel style has been shown to be a useful concept for understanding travelers. In this study it is argued that the portfolio of trips (specifically, the portfolio of various trip styles) one takes can be used to describe his/her overall travel persona. Network analysis was used to examine...... personae which, in turn, are related to their choices of places visited and their response to advertising materials. It was concluded that the framework provided by these findings along with new tools on the Internet offer the potential to develop highly personalized communications with existing...

  2. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    The invention broadly involves a method and means for generating a traveling wave laser pulse and is basically analogous to a single pass light amplifier system. However, the invention provides a traveling wave laser pulse of almost unlimited energy content, wherein a gain medium is pumped in a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  3. Travelers' Health: Water Disinfection for Travelers

    Science.gov (United States)

    ... Safety Road Safety - 8 Steps MERS Health Advisory poster MERS Pictogram CDC Guide for Healthy Travel Website ... compressed carbon, or large-pore hollow-fiber filter elements are sufficient to remove bacteria and protozoan cysts ...

  4. Topic Map for Authentic Travel

    OpenAIRE

    Wandsvik, Atle; Zare, Mehdi

    2007-01-01

    E-business is a new trend in Internet use. Authentic travel is an approach to travel and travel business which helps the traveler experience what is authentic in the travel destination. But how can the traveler find those small authentic spots and organize them together to compose a vacation? E-business techniques, combined withTopic Maps, can help.

  5. Travel characteristics and health practices among travellers at the travellers' health and vaccination clinic in Singapore.

    Science.gov (United States)

    Lee, Vernon J; Wilder-Smith, Annelies

    2006-10-01

    Singapore has a fast-growing travel industry, but few studies have been done on travel characteristics and travel health practices. This study describes the profile and healthseeking behaviour of travellers attending a travel health clinic in Singapore. A cross-sectional survey was conducted on travellers attending the Traveller's Health and Vaccination Centre (THVC) between September and November 2002 using a standardised questionnaire. Information obtained included individual demographic and medical information, travel patterns, vaccination status and travel health practices. Four hundred and ninetyfive (74%) eligible travellers seen at THVC responded to the questionnaire. Their mean age was 36 years; 77% were professionals, managers, executives, and businessmen, students, and white collar workers. Asia was the main travel destination, and most travelled for leisure and resided in hotels or hostels. The median duration of travel was 16 days. Although >90% had previously travelled overseas, only 20% had previously sought pre-travel advice. Malays were significantly underrepresented (P travel advice compared with Chinese, Indians and Malays. Factors associated with seeking pre-travel advice included travel outside of Asia, especially Africa and South America. Singaporean travellers travel more often to cities rather than rural areas, compared with non-Asian travellers. Asia is the preferred destination, and travel outside of Asia is perceived as more risky and is associated with seeking pre-travel advice and vaccinations. Travel patterns and behaviours need to be taken into account when developing evidence-based travel medicine in Asia.

  6. TRAVEL AND HOME LEAVE

    CERN Multimedia

    Human Resources Division

    2002-01-01

    Administrative procedures for : Travel to the home station and home leave (hl) Additional travel to the home station (at) Travel to the home station and home leave for family reasons (hlf) As part of the process of simplifying administrative procedures, HR and AS Divisions have devised a new, virtually automatic procedure for payment of travel expenses to the home station. The changes are aimed at rationalising administrative procedures and not at reducing benefits. The conditions of eligibility are unchanged. The new procedure, which will be operational with effect from 1st June 2002, will greatly simplify the administrative processing of claims for travel expenses and the recording of home leaves. Currently, requests for payment are introduced manually into the Advances and Claims system (AVCL) by divisional secretariats. All travel to the home station starting prior to 1st June 2002 will be processed according to the existing system whereas that starting on 1st June and after will be processed accordi...

  7. FORMS OF YOUTH TRAVEL

    OpenAIRE

    Moisã Claudia Olimpia; Moisã Claudia Olimpia

    2011-01-01

    Taking into account the suite of motivation that youth has when practicing tourism, it can be said that the youth travel takes highly diverse forms. These forms are educational tourism, volunteer programs and “work and travel”, cultural exchanges or sports tourism and adventure travel. In this article, we identified and analyzed in detail the main forms of youth travel both internationally and in Romania. We also illustrated for each form of tourism the specific tourism products targeting you...

  8. Travelling or not?

    DEFF Research Database (Denmark)

    Helles, Rasmus; Lai, Signe Sophus

    2017-01-01

    -12) travelling to multiple countries on several continents. The article shows that there are systematic differences in terms of formal characteristics, themes, and characters’ communicative style between the series that travel and the series that do not. Especially, the analysis finds that the presence of strong...... female lead characters is systematically linked to the positive travel patterns of the series, and that this cuts across different genres of series. The analysis also finds that series, which have explicitly low production values and simple narrative structure, systematically travels poorer....

  9. Pre-Travel Medical Preparation of Business and Occupational Travelers

    Science.gov (United States)

    Khan, Nomana M.; Jentes, Emily S.; Brown, Clive; Han, Pauline; Rao, Sowmya R.; Kozarsky, Phyllis; Hagmann, Stefan H.F.; LaRocque, Regina C.; Ryan, Edward T.

    2016-01-01

    Objectives: The aim of the study was to understand more about pre-travel preparations and itineraries of business and occupational travelers. Methods: De-identified data from 18 Global TravEpiNet clinics from January 2009 to December 2012 were analyzed. Results: Of 23,534 travelers, 61% were non-occupational and 39% occupational. Business travelers were more likely to be men, had short times to departure and shorter trip durations, and commonly refused influenza, meningococcal, and hepatitis B vaccines. Most business travelers indicated that employers suggested the pre-travel health consultation, whereas non-occupational travelers sought consultations because of travel health concerns. Conclusions: Sub-groups of occupational travelers have characteristic profiles, with business travelers being particularly distinct. Employers play a role in encouraging business travelers to seek pre-travel consultations. Such consultations, even if scheduled immediately before travel, can identify vaccination gaps and increase coverage. PMID:26479857

  10. CARLSON WAGONLIT TRAVEL

    CERN Multimedia

    2006-01-01

    CARLSON WAGONLIT TRAVEL informs you that our agency will be closed from 22 December 2006 at 16:30 until 8 January 2007 at 8:30. For all URGENT MATTERS you can contact our CARLSON WAGONLIT TRAVEL branch at W.H.O. (Mr Pierre Plumettaz), phone: 022 791 55 95. We wish you already a Merry Christmas and a Happy New Year!

  11. CARLSON WAGONLIT TRAVEL

    CERN Document Server

    CARLSON WAGONLIT TRAVEL

    2004-01-01

    CARLSON WAGONLIT TRAVEL informs you that our agency will be closed from 17 December 2004 at 16:30 until 3 January 2005 at 8:30. For all URGENT MATTERS you can contact our CARLSON WAGONLIT TRAVEL branch at WHO (Mr Pierre Plumettaz), phone: 022 788 10 65 We wish you already a Merry Christmas and a Happy New Year!

  12. Value of travel time.

    Science.gov (United States)

    2016-08-01

    Knowingly or not, people generally place economic value on their time. Wage workers are paid a rate per hour, and service providers may charge per hour of their time. In the transportation realm, travelers place a value on their travel time and have ...

  13. Travel health prevention.

    Science.gov (United States)

    Korzeniewski, Krzysztof

    All around the world there has been a rapid growth in the number of international travels. According to the World Tourism Organisation the number of international tourist arrivals reached 1,235 billion in 2016 and continues to grow at a high rate. This has been much due to the development of air transport (including low-cost airlines), increasingly common economic migration, a growing number of travellers visiting friends and relatives, and an increase in medical tourism. With tropical destinations becoming increasingly popular among travellers, doctors have seen a rising number of patients who seek medical advice on health risks prevalent in hot countries and health prevention measures to be taken in tropical destinations, especially where sanitation is poor. The risk for developing a medical condition while staying abroad depends on a variety of factors, including the traveller's general health condition, health prevention measures taken before or during travel (vaccinations, antimalarial chemoprophylaxis, health precautions during air, road and sea travel, proper acclimatisation, prevention of heat injuries, protection against local flora and fauna, personal hygiene, water, food and feeding hygiene), as well as the prevalence of health risk factors in a given location. Health prevention is a precondition for safe travel and maintaining good physical health; in the era of a rapid growth in international tourism it has become of key importance for all travellers.

  14. Travel and transport

    DEFF Research Database (Denmark)

    Bill, Jan; Roesdahl, Else

    2007-01-01

    On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments......On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments...

  15. Travel/Travelers and Parasitic Diseases

    Science.gov (United States)

    ... of the world and specific country. Many infectious diseases transmitted in food and water can also be acquired directly through the fecal-oral route. Parasitic Illnesses That Can Be Acquired During Travel* From Contaminated Food and Water More ... filariasis African sleeping sickness Onchoceriasis *This list ...

  16. NADIM-Travel: A Multiagent Platform for Travel Services Aggregation

    OpenAIRE

    Ben Ameur, Houssein; Bédard, François; Vaucher, Stéphane; Kropf, Peter; Chaib-draaa, Brahim; Gérin-Lajoie, Robert

    2010-01-01

    With the Internet as a growing channel for travel services distribution, sophisticated travel services aggregators are increasingly in demand. A travel services aggregation platform should be able to manage the heterogeneous characteristics of the many existing travel services. It should also be as scalable, robust, and flexible as possible. Using multiagent technology, we designed and implemented a multiagent platform for travel services aggregation called NADIM-Travel. In this platform, a p...

  17. Travel time data collection handbook

    Science.gov (United States)

    1998-03-01

    This Travel Time Data Collection Handbook provides guidance to transportation : professionals and practitioners for the collection, reduction, and presentation : of travel time data. The handbook should be a useful reference for designing : travel ti...

  18. Intercity Travel Demand Analysis Model

    OpenAIRE

    Ming Lu; Hai Zhu; Xia Luo; Lei Lei

    2014-01-01

    It is well known that intercity travel is an important component of travel demand which belongs to short distance corridor travel. The conventional four-step method is no longer suitable for short distance corridor travel demand analysis for the time spent on urban traffic has a great impact on traveler's main mode choice. To solve this problem, the author studied the existing intercity travel demand analysis model, then improved it based on the study, and finally established a combined model...

  19. An Adaptive Clustering Approach Based on Minimum Travel Route Planning for Wireless Sensor Networks with a Mobile Sink.

    Science.gov (United States)

    Tang, Jiqiang; Yang, Wu; Zhu, Lingyun; Wang, Dong; Feng, Xin

    2017-04-26

    In recent years, Wireless Sensor Networks with a Mobile Sink (WSN-MS) have been an active research topic due to the widespread use of mobile devices. However, how to get the balance between data delivery latency and energy consumption becomes a key issue of WSN-MS. In this paper, we study the clustering approach by jointly considering the Route planning for mobile sink and Clustering Problem (RCP) for static sensor nodes. We solve the RCP problem by using the minimum travel route clustering approach, which applies the minimum travel route of the mobile sink to guide the clustering process. We formulate the RCP problem as an Integer Non-Linear Programming (INLP) problem to shorten the travel route of the mobile sink under three constraints: the communication hops constraint, the travel route constraint and the loop avoidance constraint. We then propose an Imprecise Induction Algorithm (IIA) based on the property that the solution with a small hop count is more feasible than that with a large hop count. The IIA algorithm includes three processes: initializing travel route planning with a Traveling Salesman Problem (TSP) algorithm, transforming the cluster head to a cluster member and transforming the cluster member to a cluster head. Extensive experimental results show that the IIA algorithm could automatically adjust cluster heads according to the maximum hops parameter and plan a shorter travel route for the mobile sink. Compared with the Shortest Path Tree-based Data-Gathering Algorithm (SPT-DGA), the IIA algorithm has the characteristics of shorter route length, smaller cluster head count and faster convergence rate.

  20. Travelers' Health: Meningococcal Disease

    Science.gov (United States)

    ... Zika Travel Information World Map of Zika Country Classification Technical Guidance Risk of Zika Virus at Your ... Meningococcal meningitis is characterized by sudden onset of headache, fever, and stiffness of the neck, sometimes accompanied ...

  1. Travel during Pregnancy

    Science.gov (United States)

    ... 36 weeks of pregnancy. Some domestic airlines restrict travel completely or require a medical certificate during the last month of pregnancy. For international flights, the cutoff point often is earlier, sometimes as early as 28 ...

  2. Tips for Travel

    Science.gov (United States)

    Avoid bringing bed bugs home by taking precautions when traveling such as inspecting bedding and luggage racks in hotel rooms, and upon returning home unpacking directly into a washing machine and dry at high temperatures.

  3. Pregnancy and travel

    Science.gov (United States)

    When traveling by land: You should be on the road no more than 5 to 6 hours a day. Always wear your seatbelt. ... of fluids. Women with health problems may need extra oxygen when flying. Talk to your provider before ...

  4. Caregiving and travel patterns.

    Science.gov (United States)

    2013-06-01

    This study explored the impact of caregiving for older adults on mobility and travel : patterns. Specifically, the focus was on how caregivers managed trips on behalf of : another who receives care. Caregiving is becoming increasingly common as the :...

  5. Malaria and Tropical Travel

    Centers for Disease Control (CDC) Podcasts

    Malaria is a serious mosquito-borne disease that can lead to death. This podcast discusses malaria risk when traveling to tropical areas, as well as how to protect yourself and your family from malaria infection.

  6. Traveling-wave photodetector

    Science.gov (United States)

    Hietala, V.M.; Vawter, G.A.

    1993-12-14

    The traveling-wave photodetector of the present invention combines an absorptive optical waveguide and an electrical transmission line, in which optical absorption in the waveguide results in a photocurrent at the electrodes of the electrical transmission line. The optical waveguide and electrical transmission line of the electrically distributed traveling-wave photodetector are designed to achieve matched velocities between the light in the optical waveguide and electrical signal generated on the transmission line. This velocity synchronization provides the traveling-wave photodetector with a large electrical bandwidth and a high quantum efficiency, because of the effective extended volume for optical absorption. The traveling-wave photodetector also provides large power dissipation, because of its large physical size. 4 figures.

  7. Malaria and Travelers

    Science.gov (United States)

    ... Providers, Emergency Consultations, and General Public. Contact Us Malaria and Travelers for U.S. Residents Recommend on Facebook ... may be at risk for infection. Determine if malaria transmission occurs at the destinations Obtain a detailed ...

  8. Travelers' Health: Scabies

    Science.gov (United States)

    ... Books, Journals, Articles & Websites Resources for the Travel Industry Yellow Book Contents Chapter 3 (83) Scabies more ... have crusted scabies. Contact with items such as clothing and bed linens that have been used by ...

  9. Carlson Wagonlit Travel

    CERN Multimedia

    Carlson Wagonlit Travel

    2005-01-01

    Dear customers, On 3 January we informed you that the airlines had decided to cease paying commission to travel agencies in Switzerland. This measure has since been progressively introduced, with rare exceptions. Consequently, in agreement with CERN, we are obliged to apply new transaction fees for private travel, with immediate effect. Carlson Wagonlit Travel (CWT) offers: A personalized, professional and competent consultancy service To seek the most economical and best solution adapted to your needs Neutrality in comparing prices and benefits Additional information concerning e.g. visa regulations, insurance, vaccinations, etc. Support in the event of problems We draw your attention to the fact that, in spite of the increase, these prices remain very competitive on today's market. Thank you for your trust and understanding. Yours truly, Carlson Wagonlit Travel CERN agency

  10. Illinois travel statistics, 2008

    Science.gov (United States)

    2009-01-01

    The 2008 Illinois Travel Statistics publication is assembled to provide detailed traffic : information to the different users of traffic data. While most users of traffic data at this level : of detail are within the Illinois Department of Transporta...

  11. Illinois travel statistics, 2009

    Science.gov (United States)

    2010-01-01

    The 2009 Illinois Travel Statistics publication is assembled to provide detailed traffic : information to the different users of traffic data. While most users of traffic data at this level : of detail are within the Illinois Department of Transporta...

  12. Illinois travel statistics, 2010

    Science.gov (United States)

    2011-01-01

    The 2010 Illinois Travel Statistics publication is assembled to provide detailed traffic : information to the different users of traffic data. While most users of traffic data at this level : of detail are within the Illinois Department of Transporta...

  13. Travelling with football teams

    African Journals Online (AJOL)

    ultimately on the performance of the teams on the playing field and not so much ... However, travelling with a football team presents the team physician .... physician to determine the nutritional ..... diarrhoea in elite athletes: an audit of one team.

  14. Travelers' Health: Cryptosporidiosis

    Science.gov (United States)

    ... associated diarrhea; cryptosporidiosis was associated with travel to Asia, particularly India, and Latin America. Another study found ... immunochromatographic cartridge assays, and microscopy with modified acid-fast staining. ... and water precautions (see Chapter 2, Food & Water ...

  15. Business travel and sustainability

    OpenAIRE

    AGUILERA, Anne

    2013-01-01

    Although it contributes significantly to the demand for transport, in particular air transport, business travel has been relatively neglected in thinking about the strategies needed to promote more sustainable mobility practices. This paper provides a two-stage approach to this subject. We begin by showing how the sustainability of business travel is relevant not only in environmental terms, but also from an economic and social perspective. In the second stage, we consider the strategies that...

  16. Travel Market Switzerland 2007

    OpenAIRE

    Laesser, Christian; Bieger, Thomas

    2008-01-01

    Technical Report and Results - In 2007, for the seventeenth time since 1972, a survey on the travel behaviour of the Swiss population was conducted. The database resulting from this project (Travel Market Switzerland 2007) is still the most extensive on private trips by the Swiss resident population. Private trips are defined/ delimited as all journeys by private persons with at least one overnight stay outside their home and their normal life and work environment. They include all types of l...

  17. Advice to Travelers

    Science.gov (United States)

    Barrett-Connor, Elizabeth

    1975-01-01

    Travelers, particularly those whose tastes or occupations lead to deviation from the usual tourist routes, are at a small but significant risk of acquiring certain diseases they would be unlikely to encounter had they remained in the continental United States. Many of these infections can be rendered unlikely even for the most adventuresome traveler through the appropriate use of immunization and chemoprophylaxis. Other infections are currently unpreventable and the physician's responsibility lies in their premorbid detection. PMID:1154779

  18. The New England travel market: changes in generational travel patterns

    Science.gov (United States)

    Rodney B. Warnick

    1995-01-01

    The purpose of this study was to examine and explore the New England domestic travel market trends, from 1979 through 1991 within the context of generations. The existing travel markets, who travel to New England, are changing by age cohorts and specifically within different generations. The New England changes in generational travel patterns do not reflect national...

  19. Travels in Architectural History

    Directory of Open Access Journals (Sweden)

    Davide Deriu

    2016-11-01

    Full Text Available Travel is a powerful force in shaping the perception of the modern world and plays an ever-growing role within architectural and urban cultures. Inextricably linked to political and ideological issues, travel redefines places and landscapes through new transport infrastructures and buildings. Architecture, in turn, is reconstructed through visual and textual narratives produced by scores of modern travellers — including writers and artists along with architects themselves. In the age of the camera, travel is bound up with new kinds of imaginaries; private records and recollections often mingle with official, stereotyped views, as the value of architectural heritage increasingly rests on the mechanical reproduction of its images. Whilst students often learn about architectural history through image collections, the place of the journey in the formation of the architect itself shifts. No longer a lone and passionate antiquarian or an itinerant designer, the modern architect eagerly hops on buses, trains, and planes in pursuit of personal as well as professional interests. Increasingly built on a presumption of mobility, architectural culture integrates travel into cultural debates and design experiments. By addressing such issues from a variety of perspectives, this collection, a special 'Architectural Histories' issue on travel, prompts us to rethink the mobile conditions in which architecture has historically been produced and received.

  20. Virtual Travel Agencies - Tourist Value through Travel Information Systems

    OpenAIRE

    Anckar, Bill

    1999-01-01

    Anckar, B. (1999), ?Virtual Travel Agencies - Tourist Value through Travel Information Systems?. IAMSR Research Report 5/99. Institute for Advanced Management Systems Research, ?bo Akademi University. As electronic commerce enables the tourist service providers to sell their products directly to the consumer, travel agencies are faced with the imminent threat of being by-passed in the travel industry chain in the information age. This paper suggests that virtual travel agencies can compete su...

  1. Hepatitis B vaccination in travelers

    NARCIS (Netherlands)

    Sonder, Gerard J. B.

    2008-01-01

    An increasing number of travelers travel to hepatitis B-endemic countries. In travel medicine, vaccinations should be advised according to risks. The actual incidence of hepatitis B infection in short-term tourists is very low and probably not higher than it is for people who do not travel. There is

  2. Travel health attitudes among Turkish business travellers to African countries.

    Science.gov (United States)

    Selcuk, Engin Burak; Kayabas, Uner; Binbasioglu, Hulisi; Otlu, Baris; Bayindir, Yasar; Bozdogan, Bulent; Karatas, Mehmet

    The number of international travellers is increasing worldwide. Although health risks related to international travel are important and generally well-understood, the perception of these risks was unclear among Turkish travellers. We aimed to evaluate the attitudes and health risk awareness of Turkish travellers travelling to African countries. A survey was performed of Turkish travellers bound for Africa from Istanbul International Ataturk Airport in July 2013. A total of 124 travellers were enrolled in the study. Among them, 62.9% had information about their destination but only 11.3% had looked for information on health problems related to travel and their destination. Of all travellers, 53.2% had at least one vaccination before travelling. The most commonly administered vaccine was for typhoid. Among the travellers, 69.3% and 80.6% had "no idea" about yellow fever vaccination and malaria prophylaxis, respectively. A positive correlation was found between a higher level of travellers' education and receiving the recommended vaccination for the destination. Our study revealed significant gaps in the vaccination and chemoprophylaxis uptake of Turkish travellers departing to Africa. An awareness and training program should be developed for travellers, as well as public health workers, to address health risks related to travel. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Travel Health Advisory Group: a joint travel industry and travel health Special Interest Group promoting healthy travel in Australia.

    Science.gov (United States)

    Leggat, Peter A; Zwar, Nicholas; Hudson, Bernie

    2012-09-01

    The Travel Health Advisory Group (THAG), established in 1997, is a joint initiative between the travel industry and travel health professionals in Australia that aims to promote healthy travel. THAG seeks to promote cooperation in improving the health of travellers between the travel industry and travel medicine professionals and to raise public awareness of the importance of travel health. From 2011, THAG has been a Special Interest Group of The Australasian College of Tropical Medicine and its membership has been active in several areas, including web-based travel health information, travel health promotion, media releases, research and education in Australia. Information is given on the objectives, membership and an overview of the various activities of the group. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Travelers' Health: Trypanosomiasis, American (Chagas Disease)

    Science.gov (United States)

    ... Stamaril clinics Disease Directory Resources Resources for Travelers Adventure Travel Animal Safety Blood Clots Bug Bites Evite ... Minute Travel Long-Term Travel Mass Gatherings Medical Tourism Mental Health Motion Sickness Natural Disasters Pregnant Travelers ...

  5. Travel Time Reliability in Indiana

    OpenAIRE

    Martchouk, Maria; Mannering, Fred L.; Singh, Lakhwinder

    2010-01-01

    Travel time and travel time reliability are important performance measures for assessing traffic condition and extent of congestion on a roadway. This study first uses a floating car technique to assess travel time and travel time reliability on a number of Indiana highways. Then the study goes on to describe the use of Bluetooth technology to collect real travel time data on a freeway and applies it to obtain two weeks of data on Interstate 69 in Indianapolis. An autoregressive model, estima...

  6. Travel-related health problems in Japanese travelers.

    Science.gov (United States)

    Mizuno, Yasutaka; Kudo, Koichiro

    2009-09-01

    Although the number of Japanese individuals traveling abroad has increased steadily, reaching approximately 17.3 million in 2007, the incidence of various travel-related health problems in Japan remains unknown. The travel-related health problems of Japanese travelers returning to Japan from abroad are analyzed by assessing the records. Data were collected retrospectively on returning travelers who visited the authors' travel clinic during the period from January 2005 through to December 2006 with any health problem acquired overseas. A total of 345 patients were included in this study (200 male, 145 female; average age, 34+/-12.3 years). Reasons for travel included leisure (45.8%); business (39.1%); visiting friends and relatives or accompanying other travelers (8.7%); volunteering (3.8%); and long stays in order to study or live (2.6%). The most visited destination was Asia (n=260), followed by Africa (n=105). The most commonly reported health problems were gastro-intestinal infections (39.1%), followed by respiratory tract infections (16.2%), animal bites (8.1%), and skin problems (5.8%). Together, malaria and dengue accounted for 10% of diagnoses in 125 febrile patients (36.2%). Although the profile of travel-related health problems in Japanese travelers is similar to that of Western travelers, the characteristics of travel were quite different. Therefore Japanese travel advice should be tailored to suit the Japanese traveler.

  7. Schistosomiasis and international travel.

    Science.gov (United States)

    Corachan, Manuel

    2002-08-15

    Infection with Schistosoma species is acquired by exposure to fresh water that harbors cercariae released by infected snails. Although the route of infection is clear, clinical presentation of the established infection in the nonimmune tourist typically differs from that in the local population of areas of endemicity. For the health care practitioner, the traveler's syndrome presents distinctive management problems: water-transmitted bacterial and viral infections may coexist, and identification of the stage of disease at presentation, along with identification of the causative species, will maximize treatment options. Travel medicine clinics serve as epidemiological antennae, helping to identify the dynamics of species transmission in geographically distinct areas. Education of persons traveling to areas of endemicity and the development of mechanical protection against exposure are needed.

  8. [Viral hepatitis in travellers].

    Science.gov (United States)

    Abreu, Cândida

    2007-01-01

    Considering the geographical asymmetric distribution of viral hepatitis A, B and E, having a much higher prevalence in the less developed world, travellers from developed countries are exposed to a considerable and often underestimated risk of hepatitis infection. In fact a significant percentage of viral hepatitis occurring in developed countries is travel related. This results from globalization and increased mobility from tourism, international work, humanitarian and religious missions or other travel related activities. Several studies published in Europe and North America shown that more than 50% of reported cases of hepatitis A are travel related. On the other hand frequent outbreaks of hepatitis A and E in specific geographic areas raise the risk of infection in these restricted zones and that should be clearly identified. Selected aspects related with the distribution of hepatitis A, B and E are reviewed, particularly the situation in Portugal according to the published studies, as well as relevant clinical manifestations and differential diagnosis of viral hepatitis. Basic prevention rules considering enteric transmitted hepatitis (hepatitis A and hepatitis E) and parenteral transmitted (hepatitis B) are reviewed as well as hepatitis A and B immunoprophylaxis. Common clinical situations and daily practice "pre travel" advice issues are discussed according to WHO/CDC recommendations and the Portuguese National Vaccination Program. Implications from near future availability of a hepatitis E vaccine, a currently in phase 2 trial, are highlighted. Potential indications for travellers to endemic countries like India, Nepal and some regions of China, where up to 30% of sporadic cases of acute viral hepatitis are caused by hepatitis E virus, are considered. Continued epidemiological surveillance for viral hepatitis is essential to recognize and control possible outbreaks, but also to identify new viral hepatitis agents that may emerge as important global health

  9. Carlson Wagonlit Travel

    CERN Document Server

    2008-01-01

    We would like to inform you that our agency will be closed from 21st December 2008 at 16:30 until 5th January 2009 at 8:30. For all URGENT MATTERS you can contact our CARLSON WAGONLIT TRAVEL at Rue du Nant in Geneva (Team 3), phone: 058 322 26 20. The agency will be open on 22nd, 23rd, 29th and 30th December. We wish you a Merry Christmas and a Happy New Year! CARLSON WAGONLIT TRAVEL CERN Agency

  10. Intergalactic Travel Bureau

    Science.gov (United States)

    Koski, Olivia; Rosin, Mark; Guerilla Science Team

    2014-03-01

    The Intergalactic Travel Bureau is an interactive theater outreach experience that engages the public in the incredible possibilities of space tourism. The Bureau is staffed by professional actors, who play the role of space travel agents, and professional astrophysicists, who play the role of resident scientists. Members of the public of all ages were invited to visit with bureau staff to plan the vacation of their dreams-to space. We describe the project's successful nine day run in New York in August 2013. Funded by the American Physical Society Public Outreach and Informing the Public Grants.

  11. Have eggs. Will travel

    DEFF Research Database (Denmark)

    Kroløkke, Charlotte

    2015-01-01

    Feminist scholars have critically questioned the practices and ethics of reproductive mobility. While the reproductive mobility of fertility patients has been foregrounded, little is known of egg donor mobility including the experiences of travelling internationally to donate eggs. Based on written...... stories and photographic material provided by forty-two egg donors, this article uses feminist cluster analysis and the concept of eggpreneurship to illustrate how global egg donors negotiate reproductive agency and choice when they travel internationally to donate their eggs. In their stories, global egg...

  12. A-Level Revision Guide: Travel and Tourism

    Science.gov (United States)

    Thirlaway, Joanne; Duckett, Ian

    2007-01-01

    A-levels in Travel and Tourism are unitised qualifications that should take a minimum of two years to achieve. Successful completion of year one results in the candidate achieving a qualification in its own right: an AS level. This AS level will be deemed a single or a double award depending on how many units have been assessed. A single award…

  13. Flu and Holiday Travel

    Centers for Disease Control (CDC) Podcasts

    2010-12-13

    This podcast explains the ways people can stay healthy and avoid the flu when traveling this winter.  Created: 12/13/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 12/13/2010.

  14. Travel time reliability modeling.

    Science.gov (United States)

    2011-07-01

    This report includes three papers as follows: : 1. Guo F., Rakha H., and Park S. (2010), "A Multi-state Travel Time Reliability Model," : Transportation Research Record: Journal of the Transportation Research Board, n 2188, : pp. 46-54. : 2. Park S.,...

  15. [Pre-travel advice and patient education of Hungarian travellers].

    Science.gov (United States)

    Lengyel, Ingrid; Felkai, Péter

    2018-03-01

    According to international surveys, over half of the travellers face some kind of health issue when travelling. The overwhelming majority of travel-related illnesses can be prevented with pre-travel medical consultations, but the syllabus and content of the consultation have to match the travel habits and culture of the given society. This publication explores the specificities and travel habits of Hungarian travellers. One hundred participants of a travel exhibition completed a survey about their international travel. As the survey was not representative, the data could only be processed through simple statistical methods. However, since the exhibition was presumably attended by those wishing to travel, the conclusions drawn from the results are worth publishing, since no similar survey in Hungary has been published before. Based on the suitable classification of age groups in travel medicine, 11% of the participants were adolescents / young adults (aged 15-24), 81% adults (25-59) and 8% elderly (60-74). Twenty-eight percent of the participants travel multiple times a year, 40% yearly and 32% of them less frequently; 16% of the adults, 8% of the adolescents and 4% of the elderly age group travel multiple times a year. The travel destinations of Hungarian travellers have remained practically unchanged since a study was conducted 13 years ago: the vast majority (95%) travelled within Europe, 2% to the United States, and 11% of them elsewhere. Since Hungarians do not travel to endemic areas, only 5% consulted their general practitioners (GPs) prior to travelling, and 29% did when they had to be vaccinated. Forty-two percent of those wishing to travel never consult their GPs, even though 29% of them are aware of some chronic illness. Instead, 51% gather their health information from the internet and only 6% from their doctors. By the contradiction between the poor health status of the majority of Hungarian travellers and the negligence of seeking pre-travel advice

  16. Do British travel agents provide adequate health advice for travellers?

    Science.gov (United States)

    Lawlor, D A; Burke, J; Bouskill, E; Conn, G; Edwards, P; Gillespie, D

    2000-01-01

    Travel-related illness is a burden for primary care, with more than two million travellers consulting a general practitioner each year. The annual cost of travel-related illness in the United Kingdom is 11 million Pounds. Travel agents are in a unique position to influence this burden as the most common and most serious problems are preventable with simple advice and/or immunisation. This study, using covert researchers, suggests this potential is not being fully utilised. PMID:10954940

  17. The Tourist Itinerary Travel Loop: historical and contemporary travel characteristics

    OpenAIRE

    Lundgren, Jan O.

    2012-01-01

    In today’s tourist travel, the travel loop represents a very popular itinerary design, although the circumstances under which it is applied, as well as its geographic scale, often differ from the grandiose loop designs of centuries past. During the past couple of decades, a popular kind of new travel has emerged, the cruise-ship travel phenomenon, which often is arranged as quite an extensive itinerary loop. . However, the cruises can also be transoceanic, even global, with the tourist flying...

  18. Malaria: prevention in travellers.

    Science.gov (United States)

    Croft, Ashley M

    2010-07-12

    Malaria transmission occurs most frequently in environments with humidity greater than 60% and ambient temperature of 25 °C to 30 °C. Risks increase with longer visits and depend on activity. Infection can follow a single mosquito bite. Incubation is usually 10 to 14 days but can be up to 18 months depending on the strain of parasite. We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of non-drug preventive interventions in non-pregnant adult travellers? What are the effects of drug prophylaxis in non-pregnant adult travellers? What are the effects of antimalaria vaccines in adult and child travellers? What are the effects of antimalaria interventions in child travellers, pregnant travellers, and in airline pilots? We searched: Medline, Embase, The Cochrane Library, and other important databases up to November 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 79 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: aerosol insecticides, amodiaquine, air conditioning and electric fans, atovaquone-proguanil, biological control measures, chloroquine (alone or with proguanil), diethyltoluamide (DEET), dietary supplementation, doxycycline, electronic mosquito repellents, full-length and light-coloured clothing, insecticide-treated clothing/nets, mefloquine, mosquito coils and vapourising mats, primaquine, pyrimethamine-dapsone, pyrimethamine-sulfadoxine, smoke, topical (skin-applied) insect repellents, and vaccines.

  19. Validation of a multimodal travel simulator with travel information provision

    NARCIS (Netherlands)

    Chorus, C.G.; Molin, E.J.E.; Arentze, T.A.; Hoogendoorn, S.P.; Timmermans, H.J.P.; Wee, van G.P.

    2007-01-01

    This paper presents a computer based travel simulator for collecting data concerning the use of next-generation ATIS and their effects on traveler decision making in a multimodal travel environment. The tool distinguishes itself by presenting a completely abstract multimodal transport network, where

  20. Valuation of Travel Time and TravelIer Information

    NARCIS (Netherlands)

    Rietveld, Piet

    2003-01-01

    The value of travel time plays an important role in cost benefit analysis of infrastructureprojects. However, the issue of uncertainty on travel times and the implications this has forestimations of travel time values has received much less attention in the literature. In thispaper we compare

  1. Traveling wave tube and method of manufacture

    Science.gov (United States)

    Vancil, Bernard K. (Inventor)

    2004-01-01

    A traveling wave tube includes a glass or other insulating envelope having a plurality of substantially parallel glass rods supported therewithin which in turn support an electron gun, a collector and an intermediate slow wave structure. The slow wave structure itself provides electrostatic focussing of a central electron beam thereby eliminating the need for focussing magnetics and materially decreasing the cost of construction as well as enabling miniaturization. The slow wave structure advantageously includes cavities along the electron beam through which the r.f. energy is propagated, or a double, interleaved ring loop structure supported by dielectric fins within a ground plane cylinder disposed coaxially within the glass envelope.

  2. Writing Travel in the Anthropocene

    DEFF Research Database (Denmark)

    Graulund, Rune

    2016-01-01

    the Anthropocene - which is to say an age in which nowhere, not the furthest reachest of the stratosphere nor the lowest point in the marine abyss, are untouched by the activities and detritus of humankind. The essay will give a short overview of the manner in which the notion of 'travel' has been contested......Travel writing critics have proclaimed the end of travel since at least the beginning of the 20th Century. Yet the global age of the 21st century presents us with a range a problems that challenge the notion of travel in manners that neither travellers, travel writers, nor travel writing critics...... could have imagined just a century ago. Globalisation and increased mobility, whether it is that of the privileged few who can travel on holiday on jet airplanes, or that of the immigrant labourer seeking employment by crossing borders on foot, have meant millions (if not indeed billions) are constantly...

  3. Knowledge Representation in Travelling Texts

    DEFF Research Database (Denmark)

    Mousten, Birthe; Locmele, Gunta

    2014-01-01

    Today, information travels fast. Texts travel, too. In a corporate context, the question is how to manage which knowledge elements should travel to a new language area or market and in which form? The decision to let knowledge elements travel or not travel highly depends on the limitation...... and the purpose of the text in a new context as well as on predefined parameters for text travel. For texts used in marketing and in technology, the question is whether culture-bound knowledge representation should be domesticated or kept as foreign elements, or should be mirrored or moulded—or should not travel...... at all! When should semantic and pragmatic elements in a text be replaced and by which other elements? The empirical basis of our work is marketing and technical texts in English, which travel into the Latvian and Danish markets, respectively....

  4. Travel opinion leaders and seekers

    DEFF Research Database (Denmark)

    Yoo, Kyung-Hyan; Gretzel, Ulrike; Zach, Florian

    2011-01-01

    While opinion leadership has been recognized as important in tourism, there has been very little empirical research investigating the phenomenon. Given new developments in social media technologies, it is especially important to understand whether travel opinion leadership and seeking are drivers...... of specific social media perceptions and behaviours. Based on an online survey of US online travellers, this paper seeks to identify travel opinion leaders and seekers and their characteristics. Further, the research conducted investigated linkages between travel opinion leadership/seeking and travel social...... media use. The findings suggest that travel opinion leadership and seeking are distinct but connected. Both opinion leaders and seekers are technology savvy, young, educated, involved in travel planning and engaged in social media use for travel. What distinguishes opinion leaders is their greater...

  5. International business travel: impact on families and travellers.

    Science.gov (United States)

    Espino, C M; Sundstrom, S M; Frick, H L; Jacobs, M; Peters, M

    2002-05-01

    Spouses and staff of the World Bank Group (WBG) were questioned about the impact of international business travel on families and travellers. Dependent variables were self reported stress, concern about the health of the traveller, and negative impact on the family. We hypothesised that several travel factors (independent variables) would be associated with these impacts. These travel factors had to do with the frequency, duration, and predictability of travel and its interference with family activities. Survey forms were developed and distributed to all spouses of travelling staff as well as a small sample of operational staff. Kendall's tau b correlation coefficients of response frequencies were computed with the data from scaled items. Written responses to open ended questions were categorised. Response rates for spouses and staff were 24% and 36%, respectively. Half the spouse sample (n=533) and almost 75% of the staff sample (n=102) reported high or very high stress due to business travel. Self reported spouse stress was associated with six out of eight travel factors. Female spouses, those with children, and younger spouses reported greater stress. Self reported staff stress was significantly associated with four out of nine travel factors. Further insight into how business travel affects families and staff (including children's behavioural changes) and how families cope was gained through responses to written questions. The findings support the notion that lengthy and frequent travel and frequent changes in travel dates which affect family plans, all characteristic of WBG missions, negatively affects many spouses and children (particularly young children) and that the strain on families contributes significantly to the stress staff feel about their travel. Policies or management practices that take into consideration family activities and give staff greater leeway in controlling and refusing travel may help relieve stress.

  6. Double Trouble

    NARCIS (Netherlands)

    Elsaesser, Thomas; Kievit, Robert; Simons, Jan

    1994-01-01

    Double Trouble highlights the career of Dutch scriptwriter and television producer Chiem van Houweninge, well-known for his long-running TV comedy series and as author of episodes for TV detective series. Double Trouble gives Van Houweninge's own views on writing and filming in television prime

  7. CARLSON WAGONLIT TRAVEL

    CERN Multimedia

    CARLSON WAGONLIT TRAVEL

    2004-01-01

    CARLSON WAGONLIT TRAVEL would like to remind you of the entry formalities applicable to those travelling to the United States. Nationals of Switzerland and of the following countries : Andorra, Australia, Austria, Belgium, Brunei, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, Liechtenstein, Luxemburg, Monaco, Netherlands, New Zealand, Norway, Portugal, San Marino, Singapore, Slovenia, Spain, Sweden and the United Kingdom, entering the United States under the Visa Waiver Program (no visa requirement), must be in possession of an machine-readable passport that is valid for at least six months after the date of the return trip. Children, including infants, must have their own passport. An entry in the parents' passport is not sufficient. For entry into the United States, an e-ticket (fax or e-mail confirmation or passenger receipt) or a return ticket to the departure point or a ticket to a subsequent onward destination (valid for 90 days) must be presented together with the green ...

  8. Travelers In The Night

    Science.gov (United States)

    Grauer, Albert D.

    2014-11-01

    Travelers In The Night is an engaging and informative series of two minute radio programs about asteroids, comets, spacecraft, and other objects in space. The pieces are evergreen in that they are current but not dated. They are published on the Public Radio Exchange and carried by a number of radio stations. For teachers, students, and kids of all ages, the script for each piece and the start of a path for further inquiry can be found on the website travelersinthenight.org . The Travelers InThe Night Pieces are written and produced by an observing member of the Catalina Sky Survey Team at the University of Arizona. DPS members are encouraged to submit program ideas which can be developed to feature their research efforts.

  9. Leisure and Travel Choice

    OpenAIRE

    María José Caride; Eduardo L. Giménez

    2003-01-01

    It is commonly recognized the relevance of transportation costs for studying recre- ational demand. However, these costs are related with travel and modal choice deci- sions. This paper o ers a theoretical explanation of the new generation of the demand for recreational goods at destiny after the introduction of a new transportation mode that is not the cheapest nor the fastest among the available modes. The main feature of the model deals with the transportation mode-dependent preferences. T...

  10. Choice, changeover, and travel

    OpenAIRE

    Baum, William M.

    1982-01-01

    Since foraging in nature can be viewed as instrumental behavior, choice between sources of food, known as “patches,” can be viewed as choice between instrumental response alternatives. Whereas the travel required to change alternatives deters changeover in nature, the changeover delay (COD) usually deters changeover in the laboratory. In this experiment, pigeons were exposed to laboratory choice situations, concurrent variable-interval schedules, that were standard except for the introduction...

  11. Diversity does not travel!

    DEFF Research Database (Denmark)

    Lund, Rebecca; Meriläinen, Susan; Tienari, Janne

    2013-01-01

    In this chapter we offer insights into the social construction of diversity in Finnish organizations and society. In Finnish organizations, gender is highlighted while other markers of diversity are blotted out. 'Non-Finns' become subject to cultural assimilation. The US-based concept of Diversit...... Management becomes adopted and adapted in particular ways. Standardized concepts of diversity and its management do not travel, rather they become translated locally. In organizational practice, globalization is slow and laborious....

  12. Malaria and Tropical Travel

    Centers for Disease Control (CDC) Podcasts

    2008-05-15

    Malaria is a serious mosquito-borne disease that can lead to death. This podcast discusses malaria risk when traveling to tropical areas, as well as how to protect yourself and your family from malaria infection.  Created: 5/15/2008 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 5/29/2008.

  13. Time - A Traveler's Guide

    Science.gov (United States)

    Pickover, Clifford A.

    1999-09-01

    "Bucky Fuller thought big," Wired magazine recently noted, "Arthur C. Clarke thinks big, but Cliff Pickover outdoes them both." In his newest book, Cliff Pickover outdoes even himself, probing a mystery that has baffled mystics, philosophers, and scientists throughout history--What is the nature of time?In Time: A Traveler's Guide , Pickover takes readers to the forefront of science as he illuminates the most mysterious phenomenon in the universe--time itself. Is time travel possible? Is time real? Does it flow in one direction only? Does it have a beginning and an end? What is eternity? Pickover's book offers a stimulating blend of Chopin, philosophy, Einstein, and modern physics, spiced with diverting side-trips to such topics as the history of clocks, the nature of free will, and the reason gold glitters. Numerous diagrams ensure readers will have no trouble following along.By the time we finish this book, we understand a wide variety of scientific concepts pertaining to time. And most important, we will understand that time travel is, indeed, possible.

  14. When CERN travels abroad

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    For the first time the new CERN travelling exhibition has gone abroad. The venue is Torino, in Italy, where it is being shown at the Museum of Natural Science in the framework of the activities of the EuroScience Open Forum (ESOF 2010). Soon after the event, the exhibition will fly to Copenhagen. The CERN traveling exhibition was inaugurated in 2009. The new ‘Accelerating Science’ exhibition was inaugurated in 2009 as part of the celebrations to mark the 450th anniversary of the University of Geneva. “CERN’s travelling exhibition is an important tool for outreach in our Member states as it carries the main messages that constitute the backbone of the Laboratory’s education and communication policy”, explains Rolf Landua, head of the Education Group, which manages the exhibition. “The 2010 European Science Open Forum in Torino will gather a lot of experts and visitors from the general public who will be able to experience in an ...

  15. Carlson Wagonlit Travel

    CERN Document Server

    2006-01-01

    Carlson Wagonlit Travel wishes to remind you of the following conditions concerning travel to the USA. Passport conditions Since 26 October 2004, nationals of the countries covered by the US Visa Waiver Programme have been required to present a valid machine-readable passport when entering the United States. Failing this, they require a valid US non-immigrant visa in addition to their passport. Passports issued after 25 October 2005 must also bear a digital photograph. Passports issued after 25 October 2006 must contain biometric data to allow visa-free entry to the US. Advanced Passenger Information System (APIS) form Since 4 October 2005, all non-US citizens travelling to the USA have been required to complete the APIS form before departure and present it when they check in. This new procedure will certainly increase the time it takes to check in. We therefore advise passengers to present themselves at the respective check-in desk in good time. The APIS form can be downloaded from our homepage: w...

  16. [Travelers, mad, wandering].

    Science.gov (United States)

    Vaschetto, Emilio

    2014-01-01

    This article explores the notion of "wandering" through the use of some phenomena enrolled at the dawn of modernity such as the Rousseau dromomanie's philosopher and writer, the origin of the first mad traveler (Albert Dadas), epidemics of mad travelers Europe and romantic tourism (with renewed acquires significance in the "beat generation" of the twentieth century). These historical facts are "mounting" as play contemporary manifestations such as loss, disorientation, to lose one's way, and wandering without reducing them only to clinical psychosis. Readings of classic psychiatrists such as Régis, Foville, Sérieux and Capgras, Tissié, go hand in hand with the current readings of the philosopher Ian Hacking and critics of pop culture as S. Reynolds and D. Diederichsen, illustrating how the travel's phenomenon can make different subjective configurations depending on historical times. In conclusion it is noted that not only psychosis exposes the wandering soul of suffering but there are also subject positions (as will be exemplified in a clinical case) and go no further nesting wandering into human existence.

  17. Update on traveler's diarrhea.

    Science.gov (United States)

    Strum, W B

    1988-07-01

    Traveler's diarrhea affects a substantial number of travelers to high-risk areas of the world. The key to controlling this troublesome disease is prevention. The most important preventive measures depend on educating patients to consume only safe foods and pure water. Physicians cannot overemphasize the importance of avoiding high-risk foods and of boiling water if a safe water supply is not available. Prophylactic medications are a secondary consideration and should be prescribed with discretion. In most cases, diarrhea is mild and self-limited, requiring only fluid and electrolyte replacement and perhaps an antidiarrheal agent. In moderate to severe cases, the addition of an antimicrobial agent may be of benefit. Until an efficacious polyvalent vaccine is developed, caution and common sense, together with discretionary dietary and hygienic practices, are the best defenses against traveler's diarrhea. The ultimate solution is greatly improved sanitation and personal hygiene, especially in high-risk countries. However, only dreamers will consider waiting for this transformation to occur.

  18. Home range and travels

    Science.gov (United States)

    Stickel, L.F.; King, John A.

    1968-01-01

    The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels

  19. Fellow travellers: Working memory and mental time travel in rodents.

    Science.gov (United States)

    Dere, Ekrem; Dere, Dorothea; de Souza Silva, Maria Angelica; Huston, Joseph P; Zlomuzica, Armin

    2017-03-19

    The impairment of mental time travel is a severe cognitive symptom in patients with brain lesions and a number of neuropsychiatric disorders. Whether animals are also able to mentally travel in time both forward and backward is still a matter of debate. In this regard, we have proposed a continuum of mental time travel abilities across different animal species, with humans being the species with the ability to perform most sophisticated forms of mental time travel. In this review and perspective article, we delineate a novel approach to understand the evolution, characteristics and function of human and animal mental time travel. Furthermore, we propose a novel approach to measure mental time travel in rodents in a comprehensive manner using a test battery composed of well-validated and easy applicable tests. Copyright © 2017. Published by Elsevier B.V.

  20. Health hazards of international travel.

    Science.gov (United States)

    Cossar, J H; Reid, D

    1989-01-01

    The growth of travel and the increasing numbers of those affected by travel-related illnesses, some of a serious nature, will cause this subject to demand the attention of the medical profession, the travel trade, travellers themselves and the health authorities of countries receiving tourists. Provision of appropriate advice for the traveller is a shared responsibility, best channelled mainly through travel agencies; it can moreover be shown to be cost-beneficial. Continued monitoring of illness in travellers and provision of information systems geared to this problem and its prevention are fully justified. They should be based on traditional channels of communication and currently-available modern technology, and be readily accessible to medical and related workers. Increased collaboration between medical workers, health educators and those involved in the travel trade would be a positive and useful contribution towards the reduction of illness and discomfort among travellers and the associated expense incurred by the various national health services concerned. There are clearly economic benefits from the development of international tourism, but these have to be balanced in countries accepting tourists by attention to the prevention of illnesses associated with travel.

  1. Approaches to groundwater travel time

    International Nuclear Information System (INIS)

    Kaplan, P.; Klavetter, E.; Peters, R.

    1989-01-01

    One of the objectives of performance assessment for the Yucca Mountain Project is to estimate the groundwater travel time at Yucca Mountain, Nevada, to determine whether the site complies with the criteria specified in the Code of Federal Regulations, Title 10 CFR 60.113 (a). The numerical standard for performance in these criteria is based on the groundwater travel time along the fastest path of likely radionuclide transport from the disturbed zone to the accessible environment. The concept of groundwater travel time as proposed in the regulations, does not have a unique mathematical statement. The purpose of this paper is to discuss the ambiguities associated with the regulatory specification of groundwater travel time, two different interpretations of groundwater travel time, and the effect of the two interpretations on estimates of the groundwater travel time

  2. Approaches to groundwater travel time

    International Nuclear Information System (INIS)

    Kaplan, P.; Klavetter, E.; Peters, R.

    1989-01-01

    One of the objectives of performance assessment for the Yucca Mountain Project is to estimate the groundwater travel time at Yucca Mountain, Nevada, to determine whether the site complies with the criteria specified in the Code of Federal Regulations. The numerical standard for performance in these criteria is based on the groundwater travel time along the fastest path of likely radionuclide transport from the disturbed zone to the accessible environment. The concept of groundwater travel time, as proposed in the regulations, does not have a unique mathematical statement. The purpose of this paper is to discuss (1) the ambiguities associated with the regulatory specification of groundwater travel time, (2) two different interpretations of groundwater travel time, and (3) the effect of the two interpretations on estimates of the groundwater travel time. 3 refs., 2 figs., 2 tabs

  3. Time travel a history

    CERN Document Server

    Gleick, James

    2016-01-01

    From the acclaimed author of The Information and Chaos, here is a mind-bending exploration of time travel: its subversive origins, its evolution in literature and science, and its influence on our understanding of time itself. The story begins at the turn of the previous century, with the young H. G. Wells writing and rewriting the fantastic tale that became his first book and an international sensation: The Time Machine. It was an era when a host of forces was converging to transmute the human understanding of time, some philosophical and some technological: the electric telegraph, the steam railroad, the discovery of buried civilizations, and the perfection of clocks. James Gleick tracks the evolution of time travel as an idea that becomes part of contemporary culture—from Marcel Proust to Doctor Who, from Jorge Luis Borges to Woody Allen. He investigates the inevitable looping paradoxes and examines the porous boundary between pulp fiction and modern physics. Finally, he delves into a temporal shift that...

  4. Anthropological Invariants in Travel Behavior

    OpenAIRE

    Marchetti, C.

    1994-01-01

    Personal travel appears to be much more under the control of basic instinct than of economic drive. This may be the reason for the systematic mismatch between the results of cost benefit analysis and the actual behavior of travelers. In this paper a list of the basic instincts that drive and contain travelers' behavior has been put together, showing how they mesh with technological progress and economic constraints.

  5. Travelling gradient thermocouple calibration

    International Nuclear Information System (INIS)

    Broomfield, G.H.

    1975-01-01

    A short discussion of the origins of the thermocouple EMF is used to re-introduce the idea that the Peltier and Thompson effects are indistinguishable from one another. Thermocouples may be viewed as devices which generate an EMF at junctions or as integrators of EMF's developed in thermal gradients. The thermal gradient view is considered the more appropriate, because of its better accord with theory and behaviour, the correct approach to calibration, and investigation of service effects is immediately obvious. Inhomogeneities arise in thermocouples during manufacture and in service. The results of travelling gradient measurements are used to show that such effects are revealed with a resolution which depends on the length of the gradient although they may be masked during simple immersion calibration. Proposed tests on thermocouples irradiated in a nuclear reactor are discussed

  6. SUNSCEEN FOR TRAVELLERS

    Directory of Open Access Journals (Sweden)

    Novita Lavi N

    2013-05-01

    Full Text Available The sun exposure brings negative effects on the skin such like early aging, spots and skin cancer as the most terrible effect. To reduce the adverse effects of the sun, it is not enough just to behavioral therapy, but also had no protection from the outside. Especially for travellers that exposed by the sun excessively. There is sunscreen, product specially formulated to absorb or deflect ultraviolet rays. A sunscreen preparation contains chemical compounds that can absorb, scatter or reflect sunlight on the skin. This writing contains about effect of ultraviolet, skin protection from ultraviolet from behavioral aspect, variaty and contents of sunscreen and sunscreen application for travellers. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  7. International Travelers' Sociodemographic, Health, and Travel Characteristics: An Italian Study.

    Science.gov (United States)

    Troiano, Gianmarco; Mercone, Astrid; Bagnoli, Alessandra; Nante, Nicola

    Approximately the 8% of travelers requires medical care, with the diagnosis of a vaccine-preventable disease. The aim of our study was to analyze the socio-demographic, health and travel characteristics of the Italian international travelers. We conducted a cross sectional study from January 2015 to June 2016, at the Travel Medicine Clinic of Siena, asking the doctor to interview patients who attended the Clinic, recording socio-demographic and travel information, malaria prophylaxis, vaccinations. The data were organized in a database and processed by software Stata®. We collected 419 questionnaires. Patients chose 71 countries for their travels; the favorite destinations were: India (6.31%), Thailand (6.31%), and Brazil (5.10%). The mean length of stay was 36.17 days. Italians, students, and freelancers tended to stay abroad for a longer time (mean: 36.4 days, 59.87 days and 64.16 days respectively). 33.17% of our sample used drugs for malaria chemoprophylaxis: 71.9% of them used Atovaquone/Proguanil (Malarone®), 26.6% used Mefloquine (Lariam®), 1.5% other drugs. The vaccinations that travelers mostly got in our study were to prevent hepatitis A (n = 264), the typhoid fever (n = 187), the Tetanus + Diphtheria + Pertussis (n = 165), the Yellow fever (n = 118) and the cholera (n = 78). Twenty-eight (6.68%) refused some recommended vaccinations. The vaccines mostly refused were for Typhoid fever (n = 20), hepatitis a (n = 9), and cholera (n = 9). Our results demonstrated that Italian international travelers are at-risk because of their poor vaccinations adherence. This implies that pre-travel counseling is fundamental to increase the knowledge of the risks and the compliance of future travelers. Copyright © 2016 Icahn School of Medicine at Mount Sinai. Published by Elsevier Inc. All rights reserved.

  8. Pre-travel advice seeking from GPs by travellers with chronic illness seen at a travel clinic.

    Science.gov (United States)

    Gagneux-Brunon, Amandine; Andrillat, Carole; Fouilloux, Pascale; Daoud, Fatiha; Defontaine, Christiane; Charles, Rodolphe; Lucht, Frédéric; Botelho-Nevers, Elisabeth

    2016-03-01

    Travellers are ageing and frequently report chronic illness. Pre-travel health advice is crucial, particularly in this subgroup, and general practitioners (GPs) are first in line for treatment adjustment before departure. Our aim is to evaluate pre-travel health advice seeking from GPs by travellers with chronic illness seen at a travel clinic. A cross-sectional observational survey using a questionnaire was conducted between August 2013 and July 2014 in travellers attending the travel medicine clinic of a tertiary university hospital in France. During the study, 2019 travellers were included. Mean age was 39.4 years (±18.8). Three hundred and ninety-one (19.4%) travellers reported a history of a chronic illness. Arterial hypertension and diabetes mellitus were the most frequently reported illnesses, affecting, respectively, 168 (8.3%) travellers and 102 (5.1%). Hajj pilgrims were more likely to report a history of chronic illness than other travellers. Only 810 (40.1%) travellers sought pre-travel advice from their GP. Six hundred and fifty-two (40.1%) healthy travellers and 158 (40.5%) travellers reporting chronic illness sought pre-travel advice from their GP (P = 0.96). Travellers with a history of chronic illness do not seek pre-travel health advice from their GP more frequently than healthy travellers. Travel health specialists are generally not the best practitioners to manage the care of underlying medical conditions presenting risks during travel. However, GPs offer continuity and disease management expertise to improve the specificity of pre-travel planning. Thus, ongoing collaboration between the traveller, GP and travel health specialist is likely to yield the best outcomes. © International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.

  9. Carlson Wagonlit Travel is moving

    CERN Multimedia

    2013-01-01

    The renovation of the Main Building continues!   Because of this, Carlson Wagonlit Travel will move from building 62 to building 510 on 4 October and the agency will be closed in the afternoon. An emergency service will be organised for official travels only. Phone: 022 799 75 73 & 022 799 75 78 / e-mail: cern@carlsonwagonlit.ch

  10. U.S. holiday travel

    Science.gov (United States)

    2003-11-01

    The Thanksgiving and Christmas/New Years holiday periods are among the busiest long-distance travel periods of the year. During the 6-day Thanksgiving travel period, the number of long-distance trips (to and from a destination 50 miles or more awa...

  11. Rabies and Risk to Travelers

    Centers for Disease Control (CDC) Podcasts

    Each year over 55,000 people die because of rabies, mostly from being bitten by rabid dogs. Over half of all rabies infections occur in children under the age of 15 who live in developing countries, but travelers are not immune. This podcast discusses some of the activities that put travelers at risk for rabies and describes ways to prevent infection.

  12. Travel and Adult Transformative Learning

    Science.gov (United States)

    Lindstrom, Steven K.

    2011-01-01

    This phenomenological research study examines the lived experience of individual adult transformation in the context of travel. Adults throughout history have experienced profound personal and perception changes as a result of significant travel events. Transformative learning occurs through experience, crisis, and reflection, all of which are…

  13. U.S. business travel

    Science.gov (United States)

    2003-10-01

    Americans make more than 405 million long-distance business trips per year, : accounting for 16% of all long-distance travel, according to a : preliminary analysis of the National Household Travel Survey (NHTS). : Conducted from 2001 to 2002, the NHT...

  14. 49 CFR 229.55 - Piston travel.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Piston travel. 229.55 Section 229.55... Piston travel. (a) Brake cylinder piston travel shall be sufficient to provide brake shoe clearance when... piston travel may not exceed 11/2 inches less than the total possible piston travel. The total possible...

  15. Travel time variability and rational inattention

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Jiang, Gege

    2017-01-01

    This paper sets up a rational inattention model for the choice of departure time for a traveler facing random travel time. The traveler chooses how much information to acquire about the travel time out-come before choosing departure time. This reduces the cost of travel time variability compared...

  16. Monitoring Travel Time Reliability on Freeways

    NARCIS (Netherlands)

    Tu, Huizhao

    2008-01-01

    Travel time and travel time reliability are important attributes of a trip. The current measures of reliability have in common that in general they all relate to the variability of travel times. However, travel time reliability does not only rely on variability but also on the stability of travel

  17. Alternate Double Single Track Lines

    Energy Technology Data Exchange (ETDEWEB)

    Moraga Contreras, P.; Grande Andrade, Z.; Castillo Ron, E.

    2016-07-01

    The paper discusses the advantages and shortcomings of alternate double single track (ADST) lines with respect to double track lines for high speed lines. ADST lines consists of sequences of double and single track segments optimally selected in order to reduce the construction and maintenance costs of railway lines and to optimize the timetables used to satisfy a given demand. The single tracks are selected to coincide with expensive segments (tunnels and viaducts) and the double tracks are chosen to coincide with flat areas and only where they are necessary. At the same time, departure times are adjusted for trains to cross at the cheap double track segments. This alternative can be used for new lines and also for existing conventional lines where some new tracks are to be constructed to reduce travel time (increase speed). The ADST proposal is illustrated with some examples of both types (new lines and where conventional lines exist), including the Palencia-Santander, the Santiago-Valparaíso-Viña del Mar and the Dublin-Belfast lines, where very important reductions (90 %) are obtained, especially where a railway infrastructure already exist. (Author)

  18. International Development Research Centre Governor Travel Policy

    International Development Research Centre (IDRC) Digital Library (Canada)

    André Lavoie

    business. Governors are required to travel to conduct IDRC business, attend ... of Governors, liaise with Centre management, and perform specific representational functions on ..... Travel between Points of Origin and Destination - Air Travel.

  19. Double Chooz

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Christian [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

    2006-05-15

    The goal of the Double Chooz reactor neutrino experiment is to search for the neutrino mixing parameter {theta}{sub 13}. Double Chooz will use two identical detectors at 150 m and 1.05 km distance from the reactor cores. The near detector is used to monitor the reactor {nu}-bar {sub e} flux while the second is dedicated to the search for a deviation from the expected (1/distance){sup 2} behavior. This two detector concept will allow a relative normalization systematic error of ca. 0.6 %. The expected sensitivity for sin{sup 2}2{theta}{sub 13} is then in the range 0.02 - 0.03 after three years of data taking. The antineutrinos will be detected in a liquid scintillator through the capture on protons followed by a gamma cascade, produced by the neutron capture on Gd.

  20. Double supergeometry

    Energy Technology Data Exchange (ETDEWEB)

    Cederwall, Martin [Division for Theoretical Physics, Department of Physics, Chalmers University of Technology,SE 412 96 Gothenburg (Sweden)

    2016-06-27

    A geometry of superspace corresponding to double field theory is developed, with type I I supergravity in D=10 as the main example. The formalism is based on an orthosymplectic extension OSp(d,d|2s) of the continuous T-duality group. Covariance under generalised super-diffeomorphisms is manifest. Ordinary superspace is obtained as a solution of the orthosymplectic section condition. A systematic study of curved superspace Bianchi identities is performed, and a relation to a double pure spinor superfield cohomology is established. A Ramond-Ramond superfield is constructed as an infinite-dimensional orthosymplectic spinor. Such objects in minimal orbits under the OSp supergroup (“pure spinors”) define super-sections.

  1. Double ambidexterity

    DEFF Research Database (Denmark)

    Kaulio, Matti; Thorén, Kent; Rohrbeck, René

    2017-01-01

    We leverage the business model innovation and ambidexterity literature to investigate a contradictory case, the Swedish-Finnish Telecom operator TeliaSonera. Despite being challenged by three major disruptions, the company not only still exists but also enjoys remarkably good financial performance....... Building on extant archival data and interviews, we carefully identify and map 26 organizational responses during 1992–2016. We find that the firm has overcome three critical phases by experimenting and pioneering with portfolios of business models and/or technological innovations. We describe...... this behaviour as double ambidexterity. We use an in-depth case study to conceptualize double ambidexterity and discuss its impact on the business's survival and enduring success....

  2. Carlson Wagonlit Travel

    CERN Multimedia

    Carlson Wagonlit Travel

    2005-01-01

    Chères clientes, chers clients, Le 3 janvier dernier, nous vous avons informé de la décision des compagnies aériennes de supprimer les commissions versées aux agences de voyages suisses. Cette mesure a été introduite progressivement pour être appliquées maintenant par toutes les compagnies, à quelques rares exceptions près. En conséquence, en accord avec le CERN, nous serons dans l'obligation d'appliquer une nouvelle liste de prix de nos transactions pour les voyages privés. Elle sera applicable dès le lundi 25 juillet 2005. Carlson Wagonlit Travel (CWT) vous propose : Son service de conseil personnalisé, professionnel et compétent Sa recherche de la solution la plus économique et la mieux adaptée à vos besoins Sa neutralité dans les comparaisons de prix et prestations Des informations com...

  3. Calculation of groundwater travel time

    International Nuclear Information System (INIS)

    Arnett, R.C.; Sagar, B.; Baca, R.G.

    1984-12-01

    Pre-waste-emplacement groundwater travel time is one indicator of the isolation capability of the geologic system surrounding a repository. Two distinct modeling approaches exist for prediction of groundwater flow paths and travel times from the repository location to the designated accessible environment boundary. These two approaches are: (1) the deterministic approach which calculates a single value prediction of groundwater travel time based on average values for input parameters and (2) the stochastic approach which yields a distribution of possible groundwater travel times as a function of the nature and magnitude of uncertainties in the model inputs. The purposes of this report are to (1) document the theoretical (i.e., mathematical) basis used to calculate groundwater pathlines and travel times in a basalt system, (2) outline limitations and ranges of applicability of the deterministic modeling approach, and (3) explain the motivation for the use of the stochastic modeling approach currently being used to predict groundwater pathlines and travel times for the Hanford Site. Example calculations of groundwater travel times are presented to highlight and compare the differences between the deterministic and stochastic modeling approaches. 28 refs

  4. Experienced travel time prediction for congested freeways

    OpenAIRE

    Yildirimoglu, Mehmet; Geroliminis, Nikolaos

    2013-01-01

    Travel time is an important performance measure for transportation systems, and dissemination of travel time information can help travelers make reliable travel decisions such as route choice or departure time. Since the traffic data collected in real time reflects the past or current conditions on the roadway, a predictive travel time methodology should be used to obtain the information to be disseminated. However, an important part of the literature either uses instantaneous travel time ass...

  5. Patients with mental problems - the most defenseless travellers.

    Science.gov (United States)

    Felkai, Peter; Kurimay, Tamas

    2017-09-01

    Severe mental illness occurring abroad is a difficult situation for patients, their families, and for the local medical community. Patients with mental problem are doublely stigmatized due to their mental illness and because they are foreigners in an unfamiliar country. The appropriate treatment is often delayed, while patients are often dealt with in a manner that violates their human rights. Moreover, repatriation - which is vital in this case - is often delayed due to the lack of international protocols for the transportation and treatment of mentally ill travelers. Authors analyzed several factors related to acute mental health problems during travel: the etiology of symptoms, the appropriate treatment possibilities abroad, and medical evacuation and repatriation of the psychotic patient. The article presents a brief review of travel-related mental disorders, the epidemiology of mental health issues faced by travelers, and the significance of pre-travel advice for these patients. The first problem is to recognize (and redress) the particular challenges faced by a psychotic patient in a strange country. The second challenge is to prepare the patients, often in a poor psychiatric state, for medical evacuation by commercial aircraft. Another important question is the best way to take the patient through customs and security control. All of these, as yet unresolved, issues can make the mental patient virtually defenseless. Although timely repatriation of a mentally ill patient is vital and urgent, most travel insurance policies exclude treatment and repatriation costs incurred due to acute mental illness. The high cost of treatment and repatriation must be paid by the patient or their family, which could lead to severe financial strain or insolvency. Changing the approaches taken by the local mental health care community, police, airport security, and insurance companies remain a challenge for psychiatrists. © International Society of Travel Medicine, 2017

  6. GH Travel & Mission Support System

    Data.gov (United States)

    US Agency for International Development — HTRAMS is a travel data collection system for GH that collects information on both the basic details of an employee's trips (destination, length, purpose, etc.) and...

  7. PPL Travel & Mission Support System

    Data.gov (United States)

    US Agency for International Development — PTRAMS is a travel data collection system for PPL that collects information on both the basic details of an employee's trips (destination, length, purpose, etc.) and...

  8. Traveler's Health: Avoid Bug Bites

    Science.gov (United States)

    ... Safety Road Safety - 8 Steps MERS Health Advisory poster MERS Pictogram CDC Guide for Healthy Travel Website ... other accommodations that are air conditioned or have good window and door screens so bugs can’t ...

  9. Travelers' Health: Injuries and Safety

    Science.gov (United States)

    ... Safety Road Safety - 8 Steps MERS Health Advisory poster MERS Pictogram CDC Guide for Healthy Travel Website ... possible, fly on larger planes (>30 seats), in good weather, during the daylight hours, and with experienced ...

  10. DCHA Travel & Mission Support System

    Data.gov (United States)

    US Agency for International Development — DTRAMS is a travel data collection system for DCHA that collects information on both the basic details of an employee's trips (destination, length, purpose, etc.)...

  11. Transmedia storytelling on travel stories

    Directory of Open Access Journals (Sweden)

    Adolfo Baltar Moreno

    2016-01-01

    Full Text Available Travel stories form part of a great tradition inside Western Culture which has served historically to describe, to understand and to imagine other cul - tures and communities, far or near, being constituted into a real narra - tive genre. This type of story has been and is a reflection of the perception of the world based on the imaginary worlds created by the travelling narrators. How do modern authors of travel stories take advantage of the opportunities offered by transmedia storytelling? The present article explores the potential of these types of stories as a privileged object of study for transmedia storytelling studies, from the analysis of a sample of 80 narrative productions based on experiences of travel and presented in diverse editions of the Festival Le Grand Bivouac (France. It also shows the existence of a new contemporary trend inside this narrative form that transcends its literary nature.

  12. Bacterial infec tions in travellers

    African Journals Online (AJOL)

    namely bacterial causes of travellers' diarrhoea and skin infections, as well as .... Vaccination: protective efficacy against typhoid may be overcome by ingesting a high bacterial load. Vaccine ..... preparation such as cream sauce. Only after ...

  13. Travel time estimation using Bluetooth.

    Science.gov (United States)

    2015-06-01

    The objective of this study was to investigate the feasibility of using a Bluetooth Probe Detection System (BPDS) to : estimate travel time in an urban area. Specifically, the study investigated the possibility of measuring overall congestion, the : ...

  14. Travel reliability inventory for Chicago.

    Science.gov (United States)

    2013-04-01

    The overarching goal of this research project is to enable state DOTs to document and monitor the reliability performance : of their highway networks. To this end, a computer tool, TRIC, was developed to produce travel reliability inventories from : ...

  15. Radiation hazard when we travel?

    International Nuclear Information System (INIS)

    Muhamat Omar

    2003-01-01

    It is apparent that we are all exposed to natural radiation while travelling from one place to another. Air and sea travelers receive the highest and the lowest radiation dose respectively. The doses received by on-land travelers are generally low although some places near the mineral and slag heaps show high radiation levels. With proper management and enforcement, the contribution from these heaps on the roadsides can be easily removed. The other important radiation source is the tunnels built through granite rocks. However, this is more concern to the construction workers rather than to travelers. Thus, the authors are of the opinion that it is worth to look into the radiation exposures to the tunnel construction workers

  16. Long distance travel ‘today’

    DEFF Research Database (Denmark)

    Christensen, Linda

    2014-01-01

    This paper presents an overview of the Dane’s long distance travel. It is a part of the Drivers and Limits project about long distance travel. Long distance travel is in the project defined as infrequent travel with overnight stay. Danes 15-85 years-old travel in average 5.5 long distance travel...... per year og which a third is for international destinations, a third is for domestic second homes and a third are other domestic trips. However, 87% of the kilometres are for international destinations and only 4% are for domestic second homes. Travel activity is very uneven distributed with only half...... of the population having had a journey during the last three month. At the other hand 60% have travelled internationally during the last year and only 2% have never travelled abroad. The paper presents among other things how the travel activity is distributed on travel purpose and mode and how the mode choice...

  17. Ground-water travel time

    International Nuclear Information System (INIS)

    Bentley, H.; Grisak, G.

    1985-01-01

    The Containment and Isolation Working Group considered issues related to the postclosure behavior of repositories in crystalline rock. This working group was further divided into subgroups to consider the progress since the 1978 GAIN Symposium and identify research needs in the individual areas of regional ground-water flow, ground-water travel time, fractional release, and cumulative release. The analysis and findings of the Ground-Water Travel Time Subgroup are presented

  18. Time travel in Goedel's space

    International Nuclear Information System (INIS)

    Pfarr, J.

    1981-01-01

    An analysis is presented of the motion of test particles in Goedel's universe. Both geodesical and nongeodesical motions are considered; the accelerations for nongeodesical motions are given. Examples for closed timelike world lines are shown and the dynamical conditions for time travel in Goedel's space-time are discussed. It is shown that these conditions alone do not suffice to exclude time travel in Goedel's space-time. (author)

  19. Sequentially pulsed traveling wave accelerator

    Science.gov (United States)

    Caporaso, George J [Livermore, CA; Nelson, Scott D [Patterson, CA; Poole, Brian R [Tracy, CA

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  20. Characteristics and pre-travel preparation of travelers at a Canadian pediatric tertiary care travel clinic: A retrospective analysis.

    Science.gov (United States)

    Ma, Xiao Wei; Pell, Lisa G; Akseer, Nadia; Khan, Sarah; Lam, Ray E; Louch, Debra; Science, Michelle; Morris, Shaun K

    2016-01-01

    International travelers are susceptible to a wide spectrum of travel related morbidities. Despite rising number of international travelers in Canada, the demographics, risk profiles, and preventative strategies of high-risk traveler groups, including pediatric travelers visiting friends and relatives (VFRs) are not well described. A descriptive analysis was conducted on pre-travel consultations completed between January 2013 and August 2014 at a large pediatric tertiary care center in Toronto, Canada. Data on demographics, travel characteristics, and pre-travel interventions were extracted from 370 pre-travel consultations. Results were compared between all VFR and non-VFR travelers, as well as between children traveling to visit friends and relatives, for vacation, and for education and/or volunteer purposes. Forty-eight percent of consultations were for children travel to visit friends and/or relatives than for other purposes (29% vs 9%, p travel for >28 days than children traveling for vacation (43% vs 1%, p traveling for education/volunteer purposes (43% vs 21%, p = 0.03). Around half of cVFRs traveled to destinations in Asia (51%). The majority stayed with locals, friends and/or relatives (85%), and nearly all traveled to urban destinations (98%). The most prescribed interventions for children were azithromycin (84%), Dukoral (66%), and the hepatitis A vaccine (60%). Atovaquone/proguanil was the most commonly prescribed antimalarial for children. Children that travel to visit friends and relatives represent a unique travel group and may require specific considerations during pre-travel preparations. Our findings can help develop targeted pre-travel strategies for children VFRs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Intercity Travel Demand Analysis Model

    Directory of Open Access Journals (Sweden)

    Ming Lu

    2014-01-01

    Full Text Available It is well known that intercity travel is an important component of travel demand which belongs to short distance corridor travel. The conventional four-step method is no longer suitable for short distance corridor travel demand analysis for the time spent on urban traffic has a great impact on traveler's main mode choice. To solve this problem, the author studied the existing intercity travel demand analysis model, then improved it based on the study, and finally established a combined model of main mode choice and access mode choice. At last, an integrated multilevel nested logit model structure system was built. The model system includes trip generation, destination choice, and mode-route choice based on multinomial logit model, and it achieved linkage and feedback of each part through logsum variable. This model was applied in Shenzhen intercity railway passenger demand forecast in 2010 as a case study. As a result, the forecast results were consistent with the actuality. The model's correctness and feasibility were verified.

  2. Infectious Risks of Traveling Abroad.

    Science.gov (United States)

    Chen, Lin H; Blair, Barbra M

    2015-08-01

    A popular leisure activity, international travel can be associated with some infections. The most common travel-related illnesses appear to be gastrointestinal, dermatologic, respiratory, and systemic febrile syndromes. The pretravel medical consultation includes immunizations, malaria chemoprophylaxis, self-treatment for traveler's diarrhea, and advice on the prevention of a myriad of other infectious causes including dengue, chikungunya, rickettsiosis, leptospirosis, schistosomiasis, and strongyloidiasis. Travel to locations experiencing outbreaks such as Ebola virus disease, Middle East respiratory syndrome, avian influenza, and chikungunya call for specific alerts on preventive strategies. After travel, evaluation of an ill traveler must explore details of exposure, including destinations visited; activities; ingestion of contaminated food or drinks; contact with vectors, animals, fresh water, or blood and body fluids; and other potential exposures. Knowledge of the geographic distribution of infectious diseases is important in generating the differential diagnoses and testing accordingly. Empiric treatment is sometimes necessary when suspicion of a certain diagnosis is strong and confirmatory tests are delayed or lacking, particularly for infections that are rapidly progressive (for example, malaria) or for which timing of testing is prolonged (such as leptospirosis).

  3. Inter-temporal variation in the travel time and travel cost parameters of transport models

    OpenAIRE

    Börjesson, Maria

    2012-01-01

    The parameters for travel time and travel cost are central in travel demand forecasting models. Since valuation of infrastructure investments requires prediction of travel demand for future evaluation years, inter-temporal variation of the travel time and travel cost parameters is a key issue in forecasting. Using two identical stated choice experiments conducted among Swedish drivers with an interval of 13 years, 1994 and 2007, this paper estimates the inter-temporal variation in travel time...

  4. Danish long distance travel A study of Danish travel behaviour and the role of infrequent travel activities

    DEFF Research Database (Denmark)

    Knudsen, Mette Aagaard

    2014-01-01

    , this is problematic. The average travel distance has steadily increased during the latest decades together with the increasing motorisation of daily travel and international aviation. Previously most focus has been on domestic daily travel activities, but globalisation has, together with changes in price structures......), the TU overnight survey, and the Danish Tourism Statistics from the Business and Holiday Survey (HBS). This has enabled focus on infrequent travel activities segmented relative to travel purpose, distance threshold, or travelling with overnight stays. At an overall level the thesis has three main.......g. socio-economic variables. The analysis of Danish travel activities described in the three different travel surveys has outlined detailed information on Danish travel behaviour at an aggregated level during the past two decades. It has above all revealed the significant role of leisure travel. Private...

  5. Morbidity among Israeli paediatric travellers.

    Science.gov (United States)

    Rabinowicz, Shira; Schwartz, Eli

    2017-09-01

    International travel, particularly to developing countries, is becoming increasingly common among the Israeli population, including an increase in the number of travelling children. Since children are a distinct travellers' population, data about their post-travel morbidity are needed. A retrospective study which examined all children (0-19 years old) who presented to our centre after international travel from 1999 to 2015. About 314 children were seen. The mean age was 10 years (SD ± 5.8). Most of the patients (80.6%) were tourists, and the rest were expatriates. The main destinations visited were South-Asia (46.5%), Sub-Saharan Africa (33.4%), Latin-America (7%) and Europe (6.4%). Overall, the most common diagnoses were gastrointestinal (GI) (mainly chronic) disorders (30.6%), followed by febrile diseases (26.4%), among which 18.1% of patients were diagnosed with dengue fever and 12% with malaria. Dermatologic conditions accounted for 25.2%. Additional diagnoses were schistosomiasis (6.4%) and neuropsychiatric symptoms (2.2%). A substantial part, 10.8%, had eosinophilia, either symptomatic or asymptomatic. Travellers to Asia, compared to travellers to Africa, presented more commonly with GI illness (OR 2.02, 95% confidence interval 1.13-3.61), and dermatologic conditions (OR 1.94, 95% confidence interval 1.05-3.61). Morbidity was associated with a variety of transmission modes, such as food-borne illnesses (30.9%), bite and sting wounds (10.2%), mosquito-borne infections (8%), freshwater contact (6.7%) and tick-borne infections (2.2%). The main conditions seen in paediatric returning travellers were GI, febrile and dermatologic illnesses, some may be rare in their country of origin. Targeting care for the suspected pathogens based on updated knowledge of epidemiology and thorough travel history is essential. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  6. Danish long distance travel A study of Danish travel behaviour and the role of infrequent travel activities

    OpenAIRE

    Knudsen, Mette Aagaard; Rich, Jeppe; Nielsen, Otto Anker

    2014-01-01

    Historically there has been a lack of knowledge with respect to long distance travel. Due to the considerable contribution of long distance travel to total travelled kilometres and the related energy consumption from the transport sector and derived impacts on greenhouse emissions, this is problematic. The average travel distance has steadily increased during the latest decades together with the increasing motorisation of daily travel and international aviation. Previously most focus has been...

  7. Towards More Responsible Business Travel : Green Travel Guide for Business Travellers

    OpenAIRE

    Aila, Anu

    2010-01-01

    The purpose of this research type thesis is to find ways how to develop sustainability in business travel. The target is increase the level of understanding and knowledge to respect natural environment and local cultures and find the right channels and ways to raise the knowledge. The study has been done to raise the awareness how business travel can be more sustainable. This thesis analyzes sustainable tourism based on the economic, environmental, and socio-cultural considerations. Green...

  8. 8 CFR 1244.15 - Travel abroad.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Travel abroad. 1244.15 Section 1244.15... REGULATIONS TEMPORARY PROTECTED STATUS FOR NATIONALS OF DESIGNATED STATES § 1244.15 Travel abroad. (a) After... Status shall not constitute permission to travel abroad. Permission to travel may be granted by the...

  9. 49 CFR 230.76 - Piston travel.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Piston travel. 230.76 Section 230.76... Tenders Brake and Signal Equipment § 230.76 Piston travel. (a) Minimum piston travel. The minimum piston travel shall be sufficient to provide proper brake shoe clearance when the brakes are released. (b...

  10. 8 CFR 244.15 - Travel abroad.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Travel abroad. 244.15 Section 244.15 Aliens... NATIONALS OF DESIGNATED STATES § 244.15 Travel abroad. (a) After the grant of Temporary Protected Status... to travel abroad. Permission to travel may be granted by the director pursuant to the Service's...

  11. A relational approach to analysing leisure travel

    NARCIS (Netherlands)

    Ettema, D.F.; Schwanen, T.

    2012-01-01

    Leisure travel makes up a very significant part of daily travel and therefore needs to be considered in any travel demand management or general land use and transportation policy. Yet, research into leisure mobility has tended to ignore important aspects of leisure travel, such as its joint

  12. The value of travel time variance

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Engelson, Leonid

    2011-01-01

    This paper considers the value of travel time variability under scheduling preferences that are defined in terms of linearly time varying utility rates associated with being at the origin and at the destination. The main result is a simple expression for the value of travel time variability...... that does not depend on the shape of the travel time distribution. The related measure of travel time variability is the variance of travel time. These conclusions apply equally to travellers who can freely choose departure time and to travellers who use a scheduled service with fixed headway. Depending...... on parameters, travellers may be risk averse or risk seeking and the value of travel time may increase or decrease in the mean travel time....

  13. Exploring the Positive Utility of Travel and Mode Choice

    Science.gov (United States)

    2017-08-01

    Why do people travel? Underlying most travel behavior research is the derived-demand paradigm of travel analysis, which assumes that travel demand is derived from the demand for spatially separated activities, traveling is a means to an end (reaching...

  14. Knowledge, attitudes, and practices evaluation about travel medicine in international travelers and medical students in Chile.

    Science.gov (United States)

    Guerrero-Lillo, Lisette; Medrano-Díaz, Jorge; Pérez, Carmen; Chacón, Rodrigo; Silva-Urra, Juan; Rodriguez-Morales, Alfonso J

    2009-01-01

    Because information about travel medicine in Chile is lacking, a knowledge, attitudes, and practices evaluation in international travelers and medical students was done. The travelers and medical students did not know the travel medicine and sanitary conditions of their destinations, although they perceived travel-associated health risks, but <10% had any vaccination and 5% got sick during international trips.

  15. 76 FR 43236 - Federal Travel Regulation (FTR): Temporary Duty (TDY) Travel Allowances: Notice of Public Meeting

    Science.gov (United States)

    2011-07-20

    ...; Sequence 5] Federal Travel Regulation (FTR): Temporary Duty (TDY) Travel Allowances: Notice of Public... public meeting. SUMMARY: The General Services Administration (GSA) is revising the Federal Travel Regulation (FTR) in an effort to streamline travel policies, increase travel efficiency and effectiveness...

  16. 76 FR 46216 - Federal Travel Regulation (FTR): Temporary Duty (TDY) Travel Allowances: Notice of Public Meeting...

    Science.gov (United States)

    2011-08-02

    ...; Sequence 5] Federal Travel Regulation (FTR): Temporary Duty (TDY) Travel Allowances: Notice of Public... and the general public in an effort to streamline travel policies, incorporated travel efficiency and.... Flynn, Deputy Director, Office of Travel, Transportation & Asset Management. [FR Doc. 2011-19482 Filed 8...

  17. Costs of travel time uncertainty and benefits of travel time information: Conceptual model and numerical examples

    NARCIS (Netherlands)

    Ettema, D.F.; Timmermans, H.J.P.

    2006-01-01

    A negative effect of congestion that tends to be overlooked is travel time uncertainty. Travel time uncertainty causes scheduling costs due to early or late arrival. The negative effects of travel time uncertainty can be reduced by providing travellers with travel time information, which improves

  18. Observational Study of Travelers' Diarrhea.

    Science.gov (United States)

    Meuris

    1995-03-01

    Background: European air travelers returning from Algeria, Egypt, Mexico, Morocco, and Tunisia were interviewed about their experience of travelers' diseases upon arrival in Brussels. Diarrhea was mentioned by 37% of the adults and 27% of the children. These subjects were questioned about the types of measures taken, type and duration of drug treatment (if any), and about duration of diarrhea and side effects experienced. Methods: Final analysis was performed based on 2160 interviews. The largest proportion of diarrhea was reported in the age group 15-24 years (46%). Results: The majority of the 2160 subjects had opted for drug treatment (81%): 927 subjects for loperamide alone, 235 for loperamide in combination with nifuroxazide, and 178 for nifuroxazide alone. Other drugs had been used less frequently. The median time to recovery was 2.4 days with loperamide compared to 3.2 days with nifuroxazide and to 3.4 days for the no-treatment group. Conclusions: A stratification of the results by severity of the diarrhea suggests a rank of antidiarrheal potency as follows: loperamide > nifuroxazide > no-drug treatment. The side effect with the highest incidence was constipation (2.4% with loperamide). (J Travel Med 2:11-15, 1995) Travelers' diarrhea is usually defined as the passage of at least three unformed stools per day or any number of such stools when accompanied by fever, abdominal cramping, or vomiting. The definition may be broadened to include more trivial bowel disturbance.1,2 The duration of this self-limited disease generally is 3 to 5 days. Medical intervention aims at shortening the duration of disease, thus allowing the sufferer to resume his or her usual activities at an early stage. A shortened period of recovery to physical well-being has obvious favorable economic implications if the traveler is on business and may help the maintenance of a desired level of quality of life while a traveler is on holiday. An observational study of various medical

  19. Health, sustainability and student travel.

    Science.gov (United States)

    Green, Gill; Morris, Jenny; Wade, Margaret

    2012-01-01

    A survey of 246 pre-registration nursing students in a University in the South West of England was carried out to explore the impact of course related travel on the student experience. Results from the survey indicated that students' main mode of transport to practice placements was by car which reflects the rural nature of the South West and the relative paucity of public transport. Long distances that many students travel to their study centre and to placements, and the concurrent financial strain that this creates, impacted negatively on the student experience. Students recognised the need to travel to a place of study and clinical placements and suggestions of minimising the negative impact of travel were offered. These included the increased use of electronic delivery of lectures, attendance at local university premises, the provision of shared transport to placements and placements closer to the student's home. Few students, however, considered the environmental impact of travel. Higher Education Institutions need to address issues of sustainability through promoting student wellbeing and taking steps to reduce greenhouse gas emissions. It is therefore important that student awareness of sustainability related issues is increased as well as focusing on reducing the environmental impact through organisational change. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Future Trends in Business Travel Decision Making

    Science.gov (United States)

    Mason, Keith J.

    2002-01-01

    This research surveys twenty large companies and their travellers to identify and evaluate the effects of pressures on the business travel market in the future. The influence of the following areas on the decision making process are addressed: (1) Corporate travel policies and increasing professionalism in corporate purchasing; (2) The development of global strategic airline alliances; (3) The emergence of low cost airlines on short haul markets; and (4) The development of internet based booking tools and travel agency IT. The survey shows differences in views between travel managers, and travellers with regard to corporate travel policies. While travel managers see policy rules, travellers interpret these as guidelines, indicating travel managers will need to take further actions to exercise true control of travel budgets. The data shows that companies are more likely to prescribe a class of airline ticket, than the choice of airline itself. Corporate hierarchical bias in travel policies is still common both for short and particularly long haul flying. Other findings show that while travel managers believe that their companies are likely to sign global deals with strategic airline groups within a five year period in a bid to consolidating spending, they also believe that nearly a third of short haul flying will be taken with low cost carriers, indicating further penetration in this business travel market by these carriers. The paper also provides other predictions about the business travel market, based on the survey findings.

  1. A stated adaptation approach to assess changes in individuals’ activity-travel behavior in presence of personalized travel information

    NARCIS (Netherlands)

    Parvaneh, Zahra; Arentze, Theo; Timmermans, Harry

    2014-01-01

    The rapid and inevitable growth of availability of travel information for travellers has increased expectations among policy makers about the benefits of travel information. It is increasingly expected that providing advanced travel information can trigger particular travel behaviors that would

  2. Fundamental Travel Demand Model Example

    Science.gov (United States)

    Hanssen, Joel

    2010-01-01

    Instances of transportation models are abundant and detailed "how to" instruction is available in the form of transportation software help documentation. The purpose of this paper is to look at the fundamental inputs required to build a transportation model by developing an example passenger travel demand model. The example model reduces the scale to a manageable size for the purpose of illustrating the data collection and analysis required before the first step of the model begins. This aspect of the model development would not reasonably be discussed in software help documentation (it is assumed the model developer comes prepared). Recommendations are derived from the example passenger travel demand model to suggest future work regarding the data collection and analysis required for a freight travel demand model.

  3. Travel and disease vector ticks.

    Science.gov (United States)

    McGarry, John W

    2011-03-01

    There are approximately twenty species of hard (ixodid) ticks worldwide that frequently affect human populations, many of which are associated with serious, sometimes fatal disease(s). When a tick travel souvenir is presented in the clinic, the risk must be immediately assessed by identifying the tick in question, ascertaining its disease vector status and determining if there has been the opportunity for the transfer of potential pathogens. This short review on identification of disease vector ticks and aspects of blood feeding and disease transmission includes the results of an examination of 59 specimens removed from UK domestic travellers and international travellers between 2002 and 2010. Sixteen tick species belonging to six genera were recorded and almost all showed evidence of blood feeding, which appears to contradict the view that because of their size, adult ticks are found early and therefore present an insignificant risk. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Elasticity of Long Distance Travelling

    DEFF Research Database (Denmark)

    Knudsen, Mette Aagaard

    2011-01-01

    With data from the Danish expenditure survey for 12 years 1996 through 2007, this study analyses household expenditures for long distance travelling. Household expenditures are examined at two levels of aggregation having the general expenditures on transportation and leisure relative to five other...... aggregated commodities at the highest level, and the specific expenditures on plane tickets and travel packages at the lowest level. The Almost Ideal Demand System is applied to determine the relationship between expenditures on transportation and leisure and all other purchased non-durables within...... packages has higher income elasticity of demand than plane tickets but also higher than transportation and leisure in general. The findings within price sensitiveness are not as sufficient estimated, but the model results indicate that travel packages is far more price elastic than plane tickets which...

  5. Toxoplasmosis as a travel risk.

    Science.gov (United States)

    Sepúlveda-Arias, Juan C; Gómez-Marin, Jorge E; Bobić, Branko; Naranjo-Galvis, Carlos A; Djurković-Djaković, Olgica

    2014-01-01

    Toxoplasma gondii is a protozoan parasite with worldwide distribution that infects more than one third of the global population. Primary infection in immunocompetent individuals is usually asymptomatic; however, different organs can be affected in immunocompromised individuals leading to the development of encephalitis, myocarditis or pneumonitis. The prevalence of infection with Toxoplasma as well as its genetic structure varies geographically and for that reason travel may be considered as a risk factor to acquire the infection. As toxoplasmosis is a foodborne disease, health care providers should give health education on prevention measures to all prospective travelers in order to decrease the risk of infection in endemic areas. This review presents an overview of the infection with T. gondii with some considerations for travelers to and from endemic zones. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Rabies and Risk to Travelers

    Centers for Disease Control (CDC) Podcasts

    2007-10-01

    Each year over 55,000 people die because of rabies, mostly from being bitten by rabid dogs. Over half of all rabies infections occur in children under the age of 15 who live in developing countries, but travelers are not immune. This podcast discusses some of the activities that put travelers at risk for rabies and describes ways to prevent infection.  Created: 10/1/2007 by National Center for the Prevention, Detection and Control of Infectious Diseases (NCPDCID).   Date Released: 10/5/2007.

  7. Traveling-Wave Membrane Photomixers

    Science.gov (United States)

    Wyss, R. A.; Martin, S. C.; Nakamura, B. J.; Neto, A.; Pasqualini, D.; Siegel, P. H.; Kadow, C.; Gossard, A. C.

    2001-01-01

    Traveling-wave photomixers have superior performance when compared with lumped area photomixers in the 1 to 3 THz frequency range. Their large active area and distributed gain mechanism assure high thermal damage threshold and elimination of the capacitive frequency roll-off. However, the losses experienced by the radio frequency wave traveling along the coplanar strips waveguide (due to underlying semi-infinite GaAs substrate) were a serious drawback. In this paper we present device designs and an experimental setup that make possible the realization of photomixers on membranes which eliminate the losses.

  8. Value of travel time savings

    DEFF Research Database (Denmark)

    Le Masurier, P.; Polak, J.; Pawlak, Janet

    2015-01-01

    A team of specialist market researchers and Value of Time experts comprising members from SYSTRA, Imperial College London and the Technical University of Denmark has conducted a formal audit and peer review of research undertaken by Arup/ITS Leeds/Accent to derive Value of Travel Time Savings...... Preference (RP) models that were used to derive final Values of Travel Time (VTT). This report contains the findings of our audit and peer review of the procedures adopted by the research team during data collection of the three surveys (SP, RP and Employers Surveys); a peer review of the reported approach...

  9. Pre-travel care for immunocompromised and chronically ill travellers: A retrospective study

    NARCIS (Netherlands)

    van Aalst, Mariëlle; Verhoeven, Roos; Omar, Freshta; Stijnis, Cornelis; van Vugt, Michèle; de Bree, Godelieve J.; Goorhuis, Abraham; Grobusch, Martin P.

    2017-01-01

    Background: Immunocompromised and chronically ill travellers (ICCITs) are susceptible to travel related diseases. In ICCITs, pre-travel care regarding vaccinations and prophylactics is complex. We evaluated the protection level by preventive measures in ICCITs by analysing rates of vaccination

  10. Safe travels? HIV transmission among Britons travelling abroad.

    Science.gov (United States)

    Rice, B; Gilbart, V L; Lawrence, J; Smith, R; Kall, M; Delpech, V

    2012-05-01

    The aim of the study was to identify and describe the characteristics of persons born in the UK who acquire HIV infection abroad. Analyses using case reports and follow-up data from the national HIV database held at the Health Protection Agency were performed. Fifteen per cent (2066 of 13 891) of UK-born adults diagnosed in England, Wales and Northern Ireland between 2002 and 2010 acquired HIV infection abroad. Thailand (534), the USA (117) and South Africa (108) were the countries most commonly reported. As compared with UK-born adults acquiring HIV infection in the UK, those acquiring HIV infection abroad were significantly (P sex with a commercial sex worker (5.6% vs. 1%, respectively). Among men infected in Thailand, 11% reported sex with a commercial sex worker. A substantial number of UK-born adults are acquiring HIV infection in countries with generalized HIV epidemics, and in common holiday destinations. Of particular concern is the high proportion of men infected reporting sex with a commercial sex worker. We recommend HIV prevention and testing efforts be extended to include travellers abroad, and that sexual health advice be provided routinely in travel health consultations and in occupational health travel advice packs, particularly to those travelling to high HIV prevalence areas and destinations for sex tourism. Safer sex messages should include an awareness of the potential detrimental health and social impacts of the sex industry. © 2012 British HIV Association.

  11. Change as a travel benefit: Exploring the impact of travel ...

    African Journals Online (AJOL)

    This paper aims, firstly, at identifying the main dimensions of perceived change induced in young people by a travel experience and, secondly, at understanding which dimensions of the tourism experience have the greatest influence on this change. A survey was designed based on the contemporary literature and ...

  12. Collection Development "Mini-Travel Guides": Traveling Light

    Science.gov (United States)

    Kaufmann, Linda M.

    2009-01-01

    Predictions regarding how much traveling Americans will be doing this year and where they might go vary, but it is expected that many will cut back on what is increasingly considered a luxury. Even so, gasoline prices are down substantially from a year ago, the stronger dollar means better prices in Europe, and there are discounts in all areas of…

  13. Travel Behavior Change in Older Travelers: Understanding Critical Reactions to Incidents Encountered in Public Transport

    OpenAIRE

    Sundling, Catherine

    2015-01-01

    Accessibility of travel may be better understood if psychological factors underlying change in travel behavior are known. This paper examines older (65+) travelers? motives for changing their travel behavior. These changes are grounded in critical incidents earlier encountered in public-transport travel. A scientific framework is developed based on cognitive and behavioral theory. In 29 individual interviews, travelers? critical reactions (i.e., cognitive, emotional, and/or behavioral) to 77 ...

  14. Mind your travel ! Motivation, time use, and intent : Three factors of travel to be investigated

    OpenAIRE

    PAPON , Francis; Meissonnier , Joël

    2013-01-01

    The objective is to investigate the drivers of travel demand beyond the need to travel to destination; travellers may engage a trip for the sake of it, at least to some extent: travel includes a share of 'primary utility'. The paper focuses on two types of data and analysis: the primary utility of travel questions passed in the last French national travel survey, and eight dimensions of a trip proposed from a sociological analysis. The paper mixes these approaches and correlate survey answ...

  15. Effect of Rainfall on Travel Time and Accuracy of Travel Time prediction with rainfall

    OpenAIRE

    CHUNG, E; EL-FAOUZI, NE; KUWAHARA, M

    2007-01-01

    Travel time is an important parameter to report to travelers. From the user's perspective, accurate predictions and an estimate of their precision are more beneficial than the current travel time since conditions may change significantly before a traveler completes the journey. Past researches have developed travel time prediction models without considering accidents and rain. Normally accident and Rain may cause to increase travel time. Therefore, it may be interesting to consider Rain and a...

  16. Contact Frequency, Travel Time, and Travel Costs for Patients with Rheumatoid Arthritis

    OpenAIRE

    Sørensen, Jan; Linde, Louise; Hetland, Merete Lund

    2014-01-01

    Objectives. To investigate travel time, and travel cost related to contacts with health care providers for patients with rheumatoid arthritis (RA) during a three-month period. Methods. Patient-reported travel time and travel cost were obtained from 2847 patients with RA. Eleven outpatient clinics across Denmark recruited patients to the study. Data collected included frequency, travel time and travel costs for contacts at rheumatology outpatient clinics, other outpatient clinics, general prac...

  17. Individual traveller health priorities and the pre-travel health consultation.

    Science.gov (United States)

    Flaherty, Gerard T; Chen, Bingling; Avalos, Gloria

    2017-09-01

    The purpose of this study was to examine the principal travel health priorities of travellers. The most frequently selected travel health concerns were accessing medical care abroad, dying abroad, insect bites, malaria, personal safety and travel security threats. The travel health risks of least concern were culture shock, fear of flying, jet lag and sexually transmitted infections. This study is the first to develop a hierarchy of self-declared travel health risk priorities among travellers. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. The value of travel time variance

    OpenAIRE

    Fosgerau, Mogens; Engelson, Leonid

    2010-01-01

    This paper considers the value of travel time variability under scheduling preferences that are de�fined in terms of linearly time-varying utility rates associated with being at the origin and at the destination. The main result is a simple expression for the value of travel time variability that does not depend on the shape of the travel time distribution. The related measure of travel time variability is the variance of travel time. These conclusions apply equally to travellers who can free...

  19. Double inflation

    International Nuclear Information System (INIS)

    Silk, J.; Turner, M.S.

    1986-04-01

    The Zel'dovich spectrum of adiabatic density perturbations is a generic prediction of inflation. There is increasing evidence that when the spectrum is normalized by observational data on small scales, there is not enough power on large scales to account for the observed large-scale structure in the Universe. Decoupling the spectrum on large and small scales could solve this problem. As a means of decoupling the large and small scales we propose double inflation (i.e., two episodes of inflation). In this scenario the spectrum on large scales is determined by the first episode of inflation and those on small scales by a second episode of inflation. We present three models for such a scenario. By nearly saturating the large angular-scale cosmic microwave anisotropy bound, we can easily account for the observed large-scale structure. We take the perturbations on small scales to be very large, deltarho/rho approx. = 0.1 to 0.01, which results in the production of primordial black holes (PBHs), early formation of structure, reionization of the Universe, and a rich array of astrophysical events. The Ω-problem is also addressed by our scenario. Allowing the density perturbations produced by the second episode of inflation to be large also lessens the fine-tuning required in the scalar potential and makes reheating much easier. We briefly speculate on the possibility that the second episode of inflation proceeds through the nucleation of bubbles, which today manifest themselves as empty bubbles whose surfaces are covered with galaxies. 37 refs., 1 fig

  20. Double Outlet Right Ventricle

    Science.gov (United States)

    ... Right Ventricle Menu Topics Topics FAQs Double Outlet Right Ventricle Double outlet right ventricle (DORV) is a rare form of congenital heart disease. En español Double outlet right ventricle (DORV) is a rare form of congenital ...

  1. Package and Assisted Travel Arrangement

    Directory of Open Access Journals (Sweden)

    Ivan Tot

    2015-01-01

    Full Text Available In the ordinary legislative procedure before the European Parliament and the Council, there is a proposal of the European Commission for the adoption of a new directive that would bring the regulation of the contract on organized tours into line with current market development of organized trips. The proposal is intended to regulate the various combinations of travel services that are today offered to passengers, particularly online, which are identical or comparable to the travel services provided in a classic pre-arranged package. The subject of the paper are the provisions of the proposal of the directive which govern the field of application of the proposed directive, in particular the proposed changes regarding the concept of "package" contained in the European Commission proposal and amendments of the European Parliament, as well as the analysis of the proposed new concept of "assisted travel arrangements." The paper also critically refers to the method of targeted maximum harmonization as a proposed new intensity of the harmonization. The conclusion is that, despite the welcome updating of an outdated text of the directive on package travel which is line with the current market needs, the proposed text of the new directive is burdened with technical and complex definitions that could lead to significant difficulties in their transposition into the provisions of national law of the Member States.

  2. Travel Agent. Occupational Simulation Kit.

    Science.gov (United States)

    Peterson, Wayne

    This career exploration instructional booklet on the travel agent's occupation is one of several resulting from the rural southwestern Colorado CEPAC Project (Career Education Process of Attitude Change). Based on a job analysis and utilizing a programed instructional format, the following content is included: A brief description of what a travel…

  3. (including travel dates) Proposed itinerary

    Indian Academy of Sciences (India)

    Ashok

    31 July to 22 August 2012 (including travel dates). Proposed itinerary: Arrival in Bangalore on 1 August. 1-5 August: Bangalore, Karnataka. Suggested institutions: Indian Institute of Science, Bangalore. St Johns Medical College & Hospital, Bangalore. Jawaharlal Nehru Centre, Bangalore. 6-8 August: Chennai, TN.

  4. Preparing Students for Travel Abroad.

    Science.gov (United States)

    Novotny, Jeanne

    1989-01-01

    This article outlines information which can be provided by the school nurse or health educator to help make student trips abroad healthy as well as educational. Topics covered include: food and water, traveler's diarrhea, handwashing, insect and animal bites, stress, and prior health problems. (IAH)

  5. Communication from Carlson Wagonlit Travel

    CERN Multimedia

    2009-01-01

    We are pleased to inform our customers that the range of tourist guides and roadmaps on sale in our offices has now been extended. We aim to help you prepare your upcoming holiday or business trip in any way we can. Please do not hesitate to contact us should you need any further information. The team at CARLSON WAGONLIT TRAVEL

  6. Travel Abroad as Culture Study.

    Science.gov (United States)

    Jantz, Richard K.; Weaver, V. Phillips

    1992-01-01

    Encourages traveling by teachers to enrich the multicultural curriculum in their classes. Includes suggestions and resources for planning overseas trips and using them to broaden teachers' perspectives and to provide background material for curriculum development. Outlines "case studies" of trips to Hungary and Greece. (CFR)

  7. Your Travel Dollar. Money Management.

    Science.gov (United States)

    Baran, Nancy H., Ed.

    This illustrated guide was designed to familiarize consumers with planning a vacation trip, whether domestic or abroad. The guide covers setting up a budget; package tours; cruises and charter flights; travel agencies and clubs; and arranging stays in hotels/motels, rental condominiums, bed-and-breakfasts, hostels, campsites, and private…

  8. Twitter for travel medicine providers.

    Science.gov (United States)

    Mills, Deborah J; Kohl, Sarah E

    2016-03-01

    Travel medicine practitioners, perhaps more so than medical practitioners working in other areas of medicine, require a constant flow of information to stay up-to-date, and provide best practice information and care to their patients. Many travel medicine providers are unaware of the popularity and potential of the Twitter platform. Twitter use among our travellers, as well as by physicians and health providers, is growing exponentially. There is a rapidly expanding body of published literature on this information tool. This review provides a brief overview of the ways Twitter is being used by health practitioners, the advantages that are peculiar to Twitter as a platform of social media, and how the interested practitioner can get started. Some key points about the dark side of Twitter are highlighted, as well as the potential benefits of using Twitter as a way to disseminate accurate medical information to the public. This article will help readers develop an increased understanding of Twitter as a tool for extracting useful facts and insights from the ever increasing volume of health information. © International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.

  9. Time Travel in the Library

    Science.gov (United States)

    Brown, Donna W.

    2005-01-01

    A Time Travel project in the library gives enthusiasm to students to connect with the past and reinforces their research skills while instilling respect for the past years. The librarian should choose one specific decade to highlight in the library and create an extravaganza that would allow memorabilia from that time period to be located without…

  10. Danish travel activities: do we travel more and longer – and to what extent?

    DEFF Research Database (Denmark)

    Knudsen, Mette Aagaard

    Two separate Danish National travel surveys are analysed to outline the amount and extent of national and international travelling during the latest 15-20 years; the national travel survey (TU) describes mainly national daily travel activities, whereas the holiday and business travel survey...... describes national and international travel activities including overnight stay(s). When sampling only respondents with trips above 100 kilometres, they only accounts for around 2% of all daily travel activities, however, this share appears to increase and suggest in general that we do travel longer....... But due to this limited share of trips, the overall impacts of longer distance travelling vanish when considering all daily travel activities. Especially as about 95% of all daily travel destinations range less than 50 kilometres away and in total induce an average trip length of 20 kilometres. If focus...

  11. 77 FR 5252 - Federal Travel Regulation; GSA E-Gov Travel Service (ETS) Transition to E-Gov Travel Service 2...

    Science.gov (United States)

    2012-02-02

    ... Travel Regulation; GSA E-Gov Travel Service (ETS) Transition to E-Gov Travel Service 2 (ETS2) AGENCY..., ETS Program Manager Center for Travel Management (QMCD), Office of Travel and Transportation Services (QMC), at [email protected] or (703) 605-2151. SUPPLEMENTARY INFORMATION: The Federal Travel...

  12. Risk factors and pre-travel healthcare of international travellers attending a Dutch travel clinic: a cross-sectional analysis.

    Science.gov (United States)

    Wieten, Rosanne W; van der Schalie, Maurice; Visser, Benjamin J; Grobusch, Martin P; van Vugt, Michèle

    2014-01-01

    The number of international travellers is currently estimated to exceed one billion annually. To address travel related health risks and facilitate risk reduction strategies, detailed knowledge of travellers' characteristics is important. In this cross-sectional study, data of a 20% sample of travellers visiting the Academic Medical Center (AMC) travel clinic Amsterdam from July 2011 to July 2012 was collected. Itineraries and protection versus exposure rates of preventable infectious diseases were mapped and reported according to STROBE guidelines. 1749 travellers were included. South-Eastern Asia, South-America and West-Africa were most frequently visited. 26.2% of the population had pre-existing medical conditions (often cardiovascular). Young and VFR travellers had a longer median travel time (28 and 30 days) compared to the overall population (21 days). Young adult travellers were relatively often vaccinated against hepatitis B (43.9% vs. 20.5%, p travellers. Pre-travel guidelines were well adhered to. Young adult travellers had high-risk itineraries but were adequately protected. Improvement of hepatitis B and rabies protection would be desirable, specifically for VFRs. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Vaccination knowledge, attitude and practice among Chinese travelers who visit travel clinics in Preparation for international travel.

    Science.gov (United States)

    Zhang, Min; Zhang, Jianming; Hao, Yutong; Fan, ZhengXing; Li, Lei; Li, Yiguang; Ju, Wendong; Zhang, Hong; Liu, Wei; Zhang, Mengzhang; Wu, Di; He, Hongtao

    2016-06-01

    Although international travel has become increasingly more common in main land China, few data are available on vaccination knowledge, attitude and practice (KAP) among Chinese travelers. In each of 14 International Travel Healthcare Centers (ITHCs) situated in mainland China 200 volunteers were recruited for a cross-sectional investigation by questionnaire on KAP related to travel vaccinations. For the evaluation the study subjects were grouped by demographic data, past travel experience, travel destination, duration of stay abroad, purpose of travel. Among the 2,800 Chinese travelers who participated in the study, 67.1% were aware of national and travel vaccination recommendations. The knowledge about vaccine preventable diseases was low. The most common sources (73.4%) of information were requirements by destination countries obtained in connection with the visa application, Chinese companies employing workers/laborers for assignments overseas, and foreign schools. The overall acceptance rate of recommended vaccines was 68.7%, but yellow fever was accepted by 99.8% of the participants when recommended. Among 81.1% respondents who recalled to have received vaccinations in the past, only 25.9% of them brought the old vaccination records with them to their ITHC consultations. The results indicate that increased awareness of the importance of pre-travel vaccination is needed among the travellers in order to improve their KAP. © International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.

  14. Demographics, health and travel characteristics of international travellers at a pre-travel clinic in Marseille, France.

    Science.gov (United States)

    Aubry, Camille; Gaudart, Jean; Gaillard, Catherine; Delmont, Jean; Parola, Philippe; Brouqui, Philippe; Gautret, Philippe

    2012-09-01

    With the aim to identify at-risk individuals among a cohort of international travellers, 3442 individuals who sought advice at Marseille travel health centre in 2009 were prospectively included. Demographics, travel characteristics, chronic medical conditions, vaccinations and antimalarial chemoprophylaxis were documented. Chronic medical conditions were reported by 11% of individuals, including hypertension (39%), asthma (20%), thyroid disease (15%) and depression (13%). 4% reported taking a daily medication, and psychotropic and cardiovascular medications were the most commonly used. Older travellers (≥60 years) accounted for 10% of the travellers and the prevalence of chronic medical conditions was 27% in this group. Individuals aged 15 years or less accounted for 13% of the travellers. Age, last minute travel (17%) and neurological and psychiatric diseases were the most frequent factors that influenced Yellow fever vaccination and malaria chemoprophylaxis, with more than one tenth of the travellers reporting at least one risk factor for which adjusted advice may be necessary. Migrants visiting their relatives in their origin country accounted for 14% of travellers and 73% of this group travelled with their family including young children. We demonstrate that a significant proportion of travellers are at-risk (43%) because of their travel conditions (VFR), their age, or their health status, and should be targeted for risk reduction strategies. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Risk factors and pre-travel healthcare of international travellers attending a Dutch travel clinic: a cross-sectional analysis

    NARCIS (Netherlands)

    Wieten, Rosanne W.; van der Schalie, Maurice; Visser, Benjamin J.; Grobusch, Martin P.; van Vugt, Michèle

    2014-01-01

    The number of international travellers is currently estimated to exceed one billion annually. To address travel related health risks and facilitate risk reduction strategies, detailed knowledge of travellers' characteristics is important. In this cross-sectional study, data of a 20% sample of

  16. Tips for Traveling with HomePEN

    Science.gov (United States)

    ... pump); if not, you might be able to purchase one. A well-travelled consumer cautions against using ... purposes. Bon Voyage! Oley Consumers with Significant Travel Experience Carol Pelisser* HPEN (603) 625-2362; capunique@comcast. ...

  17. Staying Healthy While You Travel (For Parents)

    Science.gov (United States)

    ... cooked or washed well and peeled. Meats and fish should be well cooked and eaten just after ... Kids Need Vaccines Before Traveling? Ebola Typhoid Fever Flying and Your Child's Ears Active Vacations Traveling and ...

  18. Travel Recommendations for the Nursing Mother

    Science.gov (United States)

    ... mothers traveling to malarious areas should ensure the antimalarial included is compatible with breastfeeding before beginning travel. ... submit" value="Submit" /> Division of Nutrition, Physical Activity, and Obesity About Us Nutrition Physical Activity Overweight & ...

  19. Travel vaccines: information for health care workers

    African Journals Online (AJOL)

    2016-07-04

    scale epidemics mostly of type A occur ... or difficulty in breathing, chest pain for pneumonia to ear pain, ..... Pavli A, Maltezou H. Travel-acquired Japanese encephalitis and vaccination ... Society for Travel Medicine (SLAMVI).

  20. Dynamic travel time estimation using regression trees.

    Science.gov (United States)

    2008-10-01

    This report presents a methodology for travel time estimation by using regression trees. The dissemination of travel time information has become crucial for effective traffic management, especially under congested road conditions. In the absence of c...

  1. Network structure and travel time perception.

    Science.gov (United States)

    Parthasarathi, Pavithra; Levinson, David; Hochmair, Hartwig

    2013-01-01

    The purpose of this research is to test the systematic variation in the perception of travel time among travelers and relate the variation to the underlying street network structure. Travel survey data from the Twin Cities metropolitan area (which includes the cities of Minneapolis and St. Paul) is used for the analysis. Travelers are classified into two groups based on the ratio of perceived and estimated commute travel time. The measures of network structure are estimated using the street network along the identified commute route. T-test comparisons are conducted to identify statistically significant differences in estimated network measures between the two traveler groups. The combined effect of these estimated network measures on travel time is then analyzed using regression models. The results from the t-test and regression analyses confirm the influence of the underlying network structure on the perception of travel time.

  2. The practice of travel medicine in Europe.

    Science.gov (United States)

    Schlagenhauf, P; Santos-O'Connor, F; Parola, P

    2010-03-01

    Europe, because of its geographical location, strategic position on trade routes, and colonial past, has a long history of caring for travellers' health. Within Europe, there is great diversity in the practice of travel medicine. Some countries have travel medicine societies and provisions for a periodic distribution of recommendations, but many countries have no national pre-travel guidelines and follow international recommendations such as those provided by the WHO. Providers of travel medicine include tropical medicine specialists, general practice nurses and physicians, specialist 'travel clinics', occupational physicians, and pharmacists. One of the core functions of the European Centre for Disease Prevention and Control-funded network of travel and tropical medicine professionals, EuroTravNet, is to document the status quo of travel medicine in Europe. A three-pronged approach is used, with a real-time online questionnaire, a structured interview with experts in each country, and web searching.

  3. Back-to-Africa', 'Double Consciousness' and the African Diaspora ...

    African Journals Online (AJOL)

    the time. These sentiments are encapsulated in DuBois' theory of “double consciousness”— “two ... histories of crossing, migration, exile, travel and exploration spawning .... suggest a conspicuous presence of the supernatural next to the real.

  4. Double hard scattering without double counting

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gaunt, Jonathan R. [VU Univ. Amsterdam (Netherlands). NIKHEF Theory Group; Schoenwald, Kay [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2017-02-15

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  5. Double hard scattering without double counting

    International Nuclear Information System (INIS)

    Diehl, Markus; Gaunt, Jonathan R.

    2017-02-01

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  6. Healthy Travel for International Adoptions

    Centers for Disease Control (CDC) Podcasts

    The number of international adoptions, many from developing countries, has doubled in the last 10 years. This podcast discusses ways adoptive families can protect their own health and the health of their new children.

  7. FACTORS INFLUENCING THE EVOLUTION OF YOUTH TRAVEL

    Directory of Open Access Journals (Sweden)

    Student Claudia MOISĂ

    2010-01-01

    Full Text Available Youth travel is an important part of global tourism, consequently, getting to know the evolution of this form of tourism requires an approach of the aspects regarding the permissive and restrictive factors that influence the youth travel dynamic worldwide. In terms of the factors that influence youth travel, we highlighted these two categories of factors (permissive and restrictive and, within each category, we tried to singularize the influence of every factor over youth travel.

  8. Travel related diseases and optimizing preventive strategies

    NARCIS (Netherlands)

    Wieten, R.W.

    2016-01-01

    With the figure of 1 billion annual travellers continuously increasing, travel is becoming more and more common. The binding element of this thesis is the aim to contribute to the improvement of pre-travel healthcare. The diseases studied either carry a high mortality (rabies, malaria, yellow fever)

  9. Travelling 'green': is tourists' happiness at stake?

    NARCIS (Netherlands)

    Nawijn, J.; Peeters, P.M.

    2010-01-01

    Several western governments have implemented environmental policies which increase the cost of air travel. Such policies aim to reduce the impact of air travel on climate change, but at the same time they restrict tourists in their travels. This study examines the extent to which the average

  10. Psychological Aspects of Travel Information Presentation

    NARCIS (Netherlands)

    Dicke-Ogenia, M.

    2012-01-01

    Congestion on road networks causes severe problems in and around large cities. Consequences of congestion include an increase in travel time and travel costs, environmental costs, economic costs, increased energy use and decreased economic growth, reduced travel time reliability, and reduced quality

  11. Discounts at the Carlson Wagonlit travel agency

    CERN Document Server

    2008-01-01

    The Carlson Wagonlit travel agency is offering exceptional discounts of up to 40% for bookings with M-Travel before 29 February 2008 and Helvetic Tours before 30 March 2008. For terms and conditions and further information please contact the CERN Carlson Wagonlit Travel office, Main Building (500), Tel. 72763.

  12. 32 CFR 726.6 - Travel orders.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Travel orders. 726.6 Section 726.6 National... MENTALLY INCOMPETENT MEMBERS OF THE NAVAL SERVICE § 726.6 Travel orders. The Chief of Naval Personnel or the Deputy Commandant, Manpower & Reserve Affairs, may issue travel orders to a member to appear...

  13. Risk of rabies exposure among travellers

    NARCIS (Netherlands)

    Wieten, R. W.; Tawil, S.; van Vugt, M.; Goorhuis, A.; Grobusch, M. P.

    2015-01-01

    In recent years, requests for rabies immunoglobulin have increased at Amsterdam's Academic Medical Center's travel clinic. Travellers who received rabies pre-exposure prophylaxis (PrEP) before travel departure have immunological memory that can quickly be activated by timely booster vaccinations

  14. 38 CFR 21.7603 - Travel expenses.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Travel expenses. 21.7603...) VOCATIONAL REHABILITATION AND EDUCATION Educational Assistance for Members of the Selected Reserve Counseling § 21.7603 Travel expenses. The Department of Veterans Affairs will not pay for any costs of travel to...

  15. 38 CFR 21.7103 - Travel expenses.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Travel expenses. 21.7103...) VOCATIONAL REHABILITATION AND EDUCATION All Volunteer Force Educational Assistance Program (Montgomery GI Bill-Active Duty) Counseling § 21.7103 Travel expenses. (a) Travel for veterans and servicemembers. (1...

  16. 38 CFR 21.9585 - Travel expenses.

    Science.gov (United States)

    2010-07-01

    ...) VOCATIONAL REHABILITATION AND EDUCATION Post-9/11 GI Bill Counseling § 21.9585 Travel expenses. VA will not pay for any costs of travel to and from the place of counseling regardless of whether the individual... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Travel expenses. 21.9585...

  17. Travel and venous thrombosis: a systematic review

    NARCIS (Netherlands)

    Kuipers, S.; Schreijer, A. J. M.; Cannegieter, S. C.; Bueller, H. R.; Rosendaal, F. R.; Middeldorp, S.

    2007-01-01

    In the past decade, numerous publications on the association between venous thrombosis (VT) and travel have been published. Relative and absolute risks of VT after travel, and particularly after travel by air, have been studied in case-control and observational follow-up studies, whereas the effect

  18. Recommended vaccines for international travelers to India.

    Science.gov (United States)

    Verma, Ramesh; Khanna, Pardeep; Chawla, Suraj

    2015-01-01

    India's tourism industry generated 6.6% of the nation's Gross Domestic Product (GDP) during 2012. International travel to India is predicted to grow at an average annual rate of ∼ 8% over the next decade. The number of foreign tourists has increased by 9% to 5.8 million. Approximately 8% of travelers to developing countries require medical care during or after travel; the main diagnoses are vaccine-preventable diseases. Travelers to India can be exposed to various infectious diseases; water-borne, water-related, and zoonotic diseases may be imported to India where the disease is not endemic. The World Health Organization (WHO) emphasizes that all international travelers should be up to date with routine vaccinations. The recommended vaccinations for travelers to India vary according to the traveler's age, immunization history, existing medical conditions, duration, legal requirements for entry into countries being visited, travelers preferences, and values. Travelers should consult with a doctor so that there is sufficient time for completion of optimal vaccination schedules. No matter where traveling, one should be aware of potential exposure to certain organisms that can cause severely illnesses, even death. There is no doubt that vaccines have reduced or virtually eliminated many diseases that killed or severely disabled children and adults just a few generations ago. Thus, travelers must take recommended vaccines per schedule before traveling to India.

  19. Environmental Impact of Long Distance Travel

    DEFF Research Database (Denmark)

    Christensen, Linda

    This paper presents an analysis of the CO2 emission resulting from long distance travel by Danes. The emissions are analysed as the Danes’ footprint the whole way from Denmark to the final destination. International travel represents 31% of the Danes’ CO2 emission from passenger travel and the cl...

  20. Environmental Impact of Long Distance Travel

    DEFF Research Database (Denmark)

    Christensen, Linda

    2016-01-01

    This paper presents an analysis of the CO2 emission resulting from long distance travel by Danes. The emissions are analysed as the Danes’ footprint the whole way from Denmark to the final destination. International travel represents 31% of the Danes’ CO2 emission from passenger travel and the cl...

  1. Family structure and its relationship to travel

    Science.gov (United States)

    Christine Cornell McCreedy; Joseph T. O' Leary; Daniel Fesenmaier

    1992-01-01

    This paper examines the relationship between family structure and travel to further understand what differences exist between family groups. Results indicate that the absence of a husband delays travel for single mothers and that they are not as well-off as their married counterparts. We examine other travel and leisure studies to make comparisons with these data,...

  2. 5 CFR 630.207 - Travel time.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Travel time. 630.207 Section 630.207... and General Provisions for Annual and Sick Leave § 630.207 Travel time. The travel time granted an employee under section 6303(d) of title 5, United States Code, is inclusive of the time necessarily...

  3. Travellers' profile, travel patterns and vaccine practices--a 10-year prospective study in a Swiss Travel Clinic.

    Science.gov (United States)

    Boubaker, Rim; Meige, Pierrette; Mialet, Catherine; Buffat, Chantal Ngarambe; Uwanyiligira, Mediatrice; Widmer, Francine; Rochat, Jacynthe; Fossati, Annie Hérard; Souvannaraj-Blanchant, Manisinh; Payot, Sylvie; Rochat, Laurence; de Vallière, Serge; Genton, Blaise; D'Acremont, Valérie

    2016-01-01

    The travel clinic in Lausanne serves a catchment area of 700 000 of inhabitants and provides pre- and post-travel consultations. This study describes the profile of attendees before departure, their travel patterns and the travel clinic practices in terms of vaccination over time. We included all pre-travel first consultation data recorded between November 2002 and December 2012 by a custom-made program DIAMM/G. We analysed client profiles, travel characteristics and vaccinations prescribed over time. Sixty-five thousand and forty-six client-trips were recorded. Fifty-one percent clients were female. Mean age was 32 years. In total, 0.1% were aged travellers had pre-existing medical conditions. Forty-six percent were travelling to Africa, 35% to Asia, 20% to Latin America and 1% (each) to Oceania and Europe; 19% visited more than one country. India was the most common destination (9.6% of travellers) followed by Thailand (8.6%) and Kenya (6.4%). Seventy-three percent of travellers were planning to travel for ≤ 4 weeks. The main reasons for travel were tourism (75%) and visiting friends and relatives (18%). Sixteen percent were backpackers. Pre-travel advice were sought a median of 29 days before departure. Ninety-nine percent received vaccine(s). The most frequently administered vaccines were hepatitis A (53%), tetanus-diphtheria (46%), yellow fever (39%), poliomyelitis (38%) and typhoid fever (30%). The profile of travel clinic attendees was younger than the general Swiss population. A significant proportion of travellers received vaccinations that are recommended in the routine national programme. These findings highlight the important role of travel clinics to (i) take care of an age group that has little contact with general practitioners and (ii) update vaccination status. The most commonly prescribed travel-related vaccines were for hepatitis A and yellow fever. The question remains to know whether clients do attend travel clinics because of compulsory

  4. Information impact on quality of travel choices: analysis of data from a multimodal travel simulator

    NARCIS (Netherlands)

    Chorus, C.G.; Arentze, T.A.; Timmermans, H.J.P.; Silva, da A.N.R.; Souza, de L.C.L.

    2007-01-01

    This paper investigates the impact of travel information on the quality of travel choices. It distinguishes itself from earlier studies on this topic by empirically investigating the impact of a variety of travel information types on the quality of observed multimodal travel choices. Choice quality

  5. 78 FR 73702 - Federal Travel Regulation (FTR); Telework Travel Expenses Test Programs

    Science.gov (United States)

    2013-12-09

    ...; Docket Number 2013-0012, Sequence 1] RIN 3090-AJ23 Federal Travel Regulation (FTR); Telework Travel...). ACTION: Final rule. SUMMARY: GSA is amending the Federal Travel Regulation (FTR) to incorporate the Telework Enhancement Act of 2010, which establishes and authorizes telework travel expenses test programs...

  6. Travel intermediaries and responsibility for compliance with EU travel law : A scattered legal picture

    NARCIS (Netherlands)

    de Vries, Anne

    Travel intermediaries, commonly known as travel agencies, are important and well-known actors in the travel sector and online travel agencies such as Expedia, Booking.com and AirBnB are booming. Although intermediaries obviously bring clear benefits for contracting parties, they also complicate the

  7. On the relationship between travel time and travel distance of commuters

    NARCIS (Netherlands)

    Rietveld, P.; Zwart, A.P.; Wee, van G.P.; Hoorn, van der T.

    1999-01-01

    This paper gives a detailed empirical analysis of the relationships between different indicators of costs of commuting trips by car: difference as the crow flies, shortest travel time according to route planner, corresponding travel distance, and reported travel time. Reported travel times are

  8. On the relationship between travel time and travel distance in the Netherlands

    NARCIS (Netherlands)

    Rietveld, P.; Zwart, B.; van Wee, B.; van der Hoorn, A.I.J.M.

    1999-01-01

    This paper gives a detailed empirical analysis of the relationships between different indicators of costs of commuting trips by car: difference as the crow flies, shortest travel time according to route planner, corresponding travel distance, and reported travel time. Reported travel times are

  9. TRAVEL IN THE SCHENGEN AREA

    CERN Multimedia

    Relations with the Host States Service

    2001-01-01

    You are reminded that holders of French residence permits (for example, the carte spéciale issued by the French Ministry of Foreign Affairs, a resident's card, a temporary residence card or a receipt issued during the renewal of such residence documents) do not need visas for tourist travel (including conferences) to countries applying the provisions of the Schengen Convention, provided that the duration of the travel is less than three months. The countries applying the provisions of the Schengen Convention are Austria, Belgium, France, Germany, Greece, Italy, Luxembourg, the Netherlands, Portugal and Spain; and since 25 March 2001 Denmark, Finland, Iceland, Norway and Sweden. For longer stays and for other than tourist visits, you are strongly advised to make enquiries at the relevant consulates.http://www.cern.ch/relations/

  10. Travelling-wave-sustained discharges

    International Nuclear Information System (INIS)

    Schlueter, Hans; Shivarova, Antonia

    2007-01-01

    This review is on discharges maintained by travelling waves: new plasma sources, discovered in 1974 and considered as a prototype of the gas discharges according to their definition as nonlinear systems which unify in a self-consistent manner plasmas and fields. In the presentation here of the fluid-plasma models of the diffusion-controlled regime of the travelling-wave-sustained discharges (TWSDs), the basic features of the discharge maintenance-the discharge self-consistency and the electron heating in the high-frequency field-are stressed. Operation of stationary and pulsed discharges, discharge maintenance without and in external magnetic fields as well as discharge production in different gases (argon, helium, helium-argon gas mixtures and hydrogen) are covered. Modulation instability of diffusion-controlled discharges and discharge filamentation at higher gas pressures are also included in the review. Experimental findings which motivate aspects of the reported modelling are pointed out

  11. Plasma Colloquium Travel Grant Program

    International Nuclear Information System (INIS)

    Hazeltine, R.D.

    1998-01-01

    OAK B188 Plasma Colloquium Travel Grant Program. The purpose of the Travel Grant Program is to increase the awareness of plasma research. The new results and techniques of plasma research in fusion plasmas, plasma processing space plasmas, basic plasma science, etc, have broad applicability throughout science. The benefits of these results are limited by the relatively low awareness and appreciation of plasma research in the larger scientific community. Whereas spontaneous interactions between plasma scientists and other scientists are useful, a focused effort in education and outreach to other scientists is efficient and is needed. The academic scientific community is the initial focus of this effort, since that permits access to a broad cross-section of scientists and future scientists including undergraduates, graduate students, faculty, and research staff

  12. The Cultural Dimensions of Travelling

    Directory of Open Access Journals (Sweden)

    Agata Wiza

    2013-07-01

    Full Text Available The aim of this article is to consider the educational benefits of a journey in the context of the increasing social and career mobility. Changes in locations and ways of life lead to changes in how we think about the world and fosters reflection on its diversity. The author analyses various forms of individual tourism aimed at deeper understanding of the culture that we are getting to know. The thesis could be drawn that travelling to another culture expands the knowledge of one’s own culture and oneself. The possibility of confronting other cultures affects the way we perceive our own. Travelling gives us distance to our day-to-day life and an opportunity to learn more about ourselves.

  13. Travelling waves in heterogeneous media

    OpenAIRE

    Boden, Adam

    2013-01-01

    In this thesis we study the existence of travelling wave type solutions for a reaction diffusion equation in R2 with a nonlinearity which depends periodically on the spatial variable. Specifically we will consider a particular class of nonlinearities where we treat the coefficient of the linear term as a parameter. For this class of nonlinearities we formulate the problem as a spatial dynamical system and use a centre manifold reduction to find conditions on the parameter and nonlinearity for...

  14. Travel Software using GPU Hardware

    CERN Document Server

    Szalwinski, Chris M; Dimov, Veliko Atanasov; CERN. Geneva. ATS Department

    2015-01-01

    Travel is the main multi-particle tracking code being used at CERN for the beam dynamics calculations through hadron and ion linear accelerators. It uses two routines for the calculation of space charge forces, namely, rings of charges and point-to-point. This report presents the studies to improve the performance of Travel using GPU hardware. The studies showed that the performance of Travel with the point-to-point simulations of space-charge effects can be speeded up at least 72 times using current GPU hardware. Simple recompilation of the source code using an Intel compiler can improve performance at least 4 times without GPU support. The limited memory of the GPU is the bottleneck. Two algorithms were investigated on this point: repeated computation and tiling. The repeating computation algorithm is simpler and is the currently recommended solution. The tiling algorithm was more complicated and degraded performance. Both build and test instructions for the parallelized version of the software are inclu...

  15. Dietary Advice for Airline Travel.

    Science.gov (United States)

    Leggat; Nowak

    1997-03-01

    In addition to their regular meal service, most of the major domestic and international airlines offer special meals. It should be noted that regular meal services on international flights often give a choice of meals, even in economy class, and often include a salad and or fruit dish, which could be consumed by most people. More airlines also seem to be moving towards having at least one more culturally appropriate meal on the menu, particularly for relevant flight sectors. However, these meals may be inappropriate for some passengers, and there is a need for this special meals service. Meals services on airlines have improved greatly in recent years, particularly with the employment of consultant dietitians to the catering staff of airlines and advances in chef training. Special meal services are designed to cater to the most common variations of meals required by most passengers for medical, religious, or other reasons. The special requirements for these meals are described elsewhere.1 It is important to realize that the meals are designed and the ingredients interpreted by that airline, and may not necessarily reflect what the traveler might eat at home. So it is important to advise travelers not to have high expectations of this special meal service. This paper aims to provide some basic practical advice for selection of special diets for airline travelers.

  16. Schistosomiasis in european travelers and migrants

    DEFF Research Database (Denmark)

    Lingscheid, Tilman; Kurth, Florian; Clerinx, Jan

    2017-01-01

    Schistosomiasis remains one of the most prevalent parasitic diseases worldwide and the infection is frequently found in travelers and migrants. The European Network for Tropical Medicine and Travel Health conducted a sentinel surveillance study on imported schistosomiasis between 1997 and 2010...... or antigen testing. Schistosomiasis remains a frequent infection in travelers and migrants to Europe. Travelers should be made aware of the risk of schistosomiasis infection when traveling to sub-Saharan Africa. Posttravel consultations particularly for returning expatriates are useful given the high...

  17. Post-harmonised European National Travel Surveys

    DEFF Research Database (Denmark)

    Christensen, Linda; Sobrino Vázquez, Natalia

    Look-up tables are collected and analysed for 12 European National Travel Surveys (NTS) in a harmonized way covering the age group 13-84 year. Travel behaviour measured as kilometres, time use and trips per traveller is compared. Trips per traveller are very similar over the countries whereas...... of walking trips rather similar with a higher level of cycling in the Netherlands, more public transport in Switzerland, and more air traffic in Sweden. Normally kilometres per respondent / inhabitant is used for national planning purpose and this is very affected by the share of mobile travellers...

  18. Additive measures of travel time variability

    DEFF Research Database (Denmark)

    Engelson, Leonid; Fosgerau, Mogens

    2011-01-01

    This paper derives a measure of travel time variability for travellers equipped with scheduling preferences defined in terms of time-varying utility rates, and who choose departure time optimally. The corresponding value of travel time variability is a constant that depends only on preference...... parameters. The measure is unique in being additive with respect to independent parts of a trip. It has the variance of travel time as a special case. Extension is provided to the case of travellers who use a scheduled service with fixed headway....

  19. Travel and migration associated infectious diseases morbidity in Europe, 2008

    NARCIS (Netherlands)

    Field, Vanessa; Gautret, Philippe; Schlagenhauf, Patricia; Burchard, Gerd-Dieter; Caumes, Eric; Jensenius, Mogens; Castelli, Francesco; Gkrania-Klotsas, Effrossyni; Weld, Leisa; Lopez-Velez, Rogelio; de Vries, Peter; von Sonnenburg, Frank; Loutan, Louis; Parola, Philippe; Simon, Fabrice; Weber, Rainer; Cramer, Jakob; Pérignon, Alice; Odolini, Silvia; Carosi, Giampiero; Chappuis, François

    2010-01-01

    Europeans represent the majority of international travellers and clinicians encountering returned patients have an essential role in recognizing, and communicating travel-associated public health risks. To investigate the morbidity of travel associated infectious diseases in European travellers, we

  20. EPA’s Travel Efficiency Method (TEAM) AMPO Presentation

    Science.gov (United States)

    Presentation describes EPA’s Travel Efficiency Assessment Method (TEAM) assessing potential travel efficiency strategies for reducing travel activity and emissions, includes reduction estimates in Vehicle Miles Traveled in four different geographic areas.

  1. The impact of injection anxiety on education of travelers about common travel risks.

    Science.gov (United States)

    Noble, Lorraine M; Farquharson, Lorna; O'Dwyer, Niamh A; Behrens, Ron H

    2014-01-01

    Despite many travelers receiving at least one vaccination during the pre-travel consultation, little is known about travelers' fear of injections and the impact this may have on educating travelers about health risks associated with their trip. This study aimed to investigate: (1) the prevalence of injection anxiety in travelers attending a pre-travel consultation, (2) whether anxiety due to anticipating a vaccination adversely affects recall of information and advice, and (3) whether clinicians can recognize travelers' anxiety, and how they respond to anxious travelers. Consecutive adult travelers (N = 105) attending one of two inner-city travel clinics completed self-report measures of state anxiety, injection anxiety, and symptoms of needle phobia immediately before and after their pre-travel consultation. Clinicians were also asked to rate travelers' anxiety and report any anxiety management strategies. Standardized information was presented during the consultation and recall of information and advice was assessed immediately post-consultation. Delayed recall (24 hours) was assessed for a subsample (20%) of participants. More than one third of travelers reported feeling nervous or afraid when having an injection (39%). Travelers' state anxiety was related to their psychological and physiological reactions to needles, and reduced significantly post-consultation. Recall of information and advice varied, with failure of recall ranging from 2 to 70% across 15 items, and delayed recall being significantly lower. No relationship was found between recall and anxiety. Clinician-rated anxiety moderately correlated with travelers' self-reported anxiety. A significant proportion of travelers experienced injection anxiety when attending the pre-travel consultation, with some travelers reporting symptoms consistent with criteria for Blood Injection Injury phobia. There were important gaps in recall of information and advice about common travel risks. Although no

  2. Business travel and sustainability. Part III. In: Handbook of Sustainable Travel: People, Society, and Transportation Systems

    OpenAIRE

    AGUILERA, Anne

    2013-01-01

    Business travel has been relatively neglected in strategies to promote sustainable travel. A two-stage approach is taken beginning by showing how sustainability of business travel is relevant not only environmentally, but also from an economic and social perspective. On the one hand, this form of travel helps to generate jobs in numerous business sectors, not only in transportation. On the other hand, the social dimension cannot be ignored either, since business travel is often a source of fa...

  3. [The profile of Israeli travelers to developing countries: perspectives of a travel clinic].

    Science.gov (United States)

    Stienlauf, Shmuel; Meltzer, Eyal; Leshem, Eyal; Rendi-Wagner, Pamela; Schwartz, Eli

    2010-09-01

    The number of Israeli travelers is increasing, including the number of travelers to developing countries. This study aimed to characterize the profile of Israeli travelers to developing countries. Data regarding demographics, travel destinations, trip duration and the purpose of travel were collected on travelers attending the pre-travel clinic at the Sheba Medical Center during a period of 9 years. Between the dates 1/1/1999 and 31/12/2007, 42,771 travelers presented for consultation at the Sheba Medical Center pre-travel clinic. The average age was 30.8 +/- 13.4 years and 54% of the travelers were males. The female proportion increased from 42% in 1999 to 49% in 2006. There was a steady increase in the number of travelers attending our clinic, except in 2003 (coinciding with the SARS epidemic). Post-army backpackers (20-25 year-old age group) were only 43% of the travelers. Children (60 years) comprised 4.4% and 4.6% of the travelers, respectively. The favorite destinations were Asia (55%), followed by Latin America (27%) and Africa (13%). The distribution of travel destinations varied significantly during the study period. Of note is the sharp decline in travel to Africa following the terrorist attack in Mombassa, Kenya (November 2002). The median trip duration changed during the study period, from 30 to 45 days, between 1999-2004 and 2005-2007 respectively. The majority (87%) of voyagers traveled for pleasure, 6% went for business, and 7% were representatives of governmental organizations. This study found an increasing diversity in the traveler population (more women, more children and older travelers) and more diversity in travel destinations. Disease outbreaks and terrorist attacks had transient negative impacts on the number of travelers.

  4. Drug use, travel and HIV risk.

    Science.gov (United States)

    Lee, D; Bell, D C; Hinojosa, M

    2002-08-01

    A study was conducted to examine the travel experiences of a community sample of 160 drug users and 44 non-users recruited as part of a study of HIV risk. Of the sample, 47% (96/204) reported intercity travel in the previous ten years. Results showed that men were more likely to travel than women, Anglos more than minorities, and young persons more than old. When travellers testing HIV-seropositive (n = 13) were compared with seronegative travellers, HIV-positive travellers reported more sex while travelling than HIV-negative persons, but virtually all of the difference reported involved sex with condoms. There were no significant differences in sex risk behaviours while travelling between drug users and non-drug users, or in sex risk behaviors between drug injectors and non-injectors. Travellers had fewer injection partners while travelling than they had while at home. There was also a significant difference in number of sex partners with whom a condom was not used, with fewer sex partners while travelling.

  5. [Travel medicine for HIV-infected patients].

    Science.gov (United States)

    Rossi, M; Furrer, H

    2001-06-01

    Many HIV-infected persons travel from temperate zones to (sub)tropical destinations. HIV-specific immigration issues, medical resources abroad and problems regarding travelling with multiple medications have to be anticipated. When prescribing immunizations and specific chemoprophylaxis, the stage of immunodeficiency as well as drug interactions with antiretrovirals and medicaments against opportunistic infections have to be taken into account. Live vaccines may be contraindicated. Immunocompromised HIV-infected travellers have a higher risk for serious courses of diseases by enteropathogens. Therefore a good information about food hygiene is important and a prescription of an antibiotic to take in case of severe diarrhea may be indicated. A new antiretroviral combination therapy should not be started immediately before travelling to the tropics. The possibility to continue an established HIV treatment during travel has to be evaluated cautiously. With good pre-travel advice the risk of severe health problems is low for most HIV-infected travellers.

  6. Business travelers: vaccination considerations for this population.

    Science.gov (United States)

    Chen, Lin H; Leder, Karin; Wilson, Mary E

    2013-04-01

    Illness in business travelers is associated with reduced productivity on the part of the employee as well as the employer. Immunizations offer a reliable method of preventing infectious diseases for international business travelers. The authors review the travel patterns of business travelers, available data on illnesses they encounter, their potential travel-associated risks for vaccine-preventable diseases and recommendations on immunizations for this population. Routine vaccines (e.g., measles, tetanus and influenza) should be reviewed to assure that they provide current coverage. The combined hepatitis A and hepatitis B vaccine with a rapid schedule offers options for those with time constraints. Other vaccine recommendations for business travelers need to focus on their destinations and activities and underlying health, taking into account the concept of cumulative risk for those with frequent travel, multiple trips or long stays.

  7. Accurate estimation of indoor travel times

    DEFF Research Database (Denmark)

    Prentow, Thor Siiger; Blunck, Henrik; Stisen, Allan

    2014-01-01

    The ability to accurately estimate indoor travel times is crucial for enabling improvements within application areas such as indoor navigation, logistics for mobile workers, and facility management. In this paper, we study the challenges inherent in indoor travel time estimation, and we propose...... the InTraTime method for accurately estimating indoor travel times via mining of historical and real-time indoor position traces. The method learns during operation both travel routes, travel times and their respective likelihood---both for routes traveled as well as for sub-routes thereof. InTraTime...... allows to specify temporal and other query parameters, such as time-of-day, day-of-week or the identity of the traveling individual. As input the method is designed to take generic position traces and is thus interoperable with a variety of indoor positioning systems. The method's advantages include...

  8. RP and SP Data-Based Travel Time Reliabiality Analysis

    OpenAIRE

    Lu, Ming

    2013-01-01

    Travel time is considered to be the key criterion when making travel related decisions. As the travel decisions are made in a dynamic environment, the travel time also changes according to the real-time operations of the transport system. More and more evidence proves that travellers are not only interested in the expected travel time but also in travel time reliability. Especially for trips that are made regularly, reliability is valued more than travel time itself. This dissertation focuses...

  9. TRAVEL

    Institute of Scientific and Technical Information of China (English)

    Phoenix

    2010-01-01

    <正>01DIY制衣爱好者之家>巴黎的Cafe数不胜数,Sweat Shop却独具一格,制衣爱好者们可以在这里一边踩着缝纫机,一边和气味相投的同好们交换心得。这家店位于巴黎第十区,毗邻Canal Saint-Martin。店内设有一张共享桌,以及10张备有缝纫机和台灯的缝纫桌。制衣爱好者可以以每小时6欧元或每天25欧元的价格(包茶和咖啡)租用。因为靠近食肆Bob’s JuiceBar,店内的食物便由这家小食店供应,包括各种口味的有机松饼和素食小吃。

  10. Travellers and influenza: risks and prevention.

    Science.gov (United States)

    Goeijenbier, M; van Genderen, P; Ward, B J; Wilder-Smith, A; Steffen, R; Osterhaus, A D M E

    2017-01-01

    Influenza viruses are among the major causes of serious human respiratory tract infection worldwide. In line with the high disease burden attributable to influenza, these viruses play an important, but often neglected, role in travel medicine. Guidelines and recommendations regarding prevention and management of influenza in travellers are scarce. Of special interest for travel medicine are risk populations and also circumstances that facilitate influenza virus transmission and spread, like travel by airplane or cruise ship and mass gatherings. We conducted a PUBMED/MEDLINE search for a combination of the MeSH terms Influenza virus, travel, mass gathering, large scale events and cruise ship. In addition we gathered guidelines and recommendations from selected countries and regarding influenza prevention and management in travellers. By reviewing these search results in the light of published knowledge in the fields of influenza prevention and management, we present best practice advice for the prevention and management of influenza in travel medicine. Seasonal influenza is among the most prevalent infectious diseases in travellers. Known host-associated risk factors include extremes of age and being immune-compromised, while the most relevant environmental factors are associated with holiday cruises and mass gatherings. Pre-travel advice should address influenza and its prevention for travellers, whenever appropriate on the basis of the epidemiological situation concerned. Preventative measures should be strongly recommended for travellers at high-risk for developing complications. In addition, seasonal influenza vaccination should be considered for any traveller wishing to reduce the risk of incapacitation, particularly cruise ship crew and passengers, as well as those participating in mass gatherings. Besides advice concerning preventive measures and vaccination, advice on the use of antivirals may be considered for some travellers. © International Society of

  11. The Archaeology of Time travel – An introduction

    OpenAIRE

    Petersson, Bodil; Holtorf, Cornelius

    2010-01-01

    This article introduces the concept of Time Travel as a new way to approach the past in our age. The article deals with the question: What role does the past play for people in our time? The time travel discussion focusses on the following themes: Time travel between materality and virtuality; Time travel on the market of experiences; Designing time travel; Evaluating time travel.

  12. Travel agents and the prevention of health problems among travelers in Québec.

    Science.gov (United States)

    Provost, Sylvie; Gaulin, Colette; Piquet-Gauthier, Blandine; Emmanuelli, Julien; Venne, Sylvie; Dion, Réjean; Grenier, Jean-Luc; Dessau, Jean-Claude; Dubuc, Martine

    2002-01-01

    Among the factors influencing travelers to seek preventive health advice before departure, the travel agent's recommendation plays an important role. The objective of our study was to document the practices and needs of travel agents in Québec (Canada) in relation to the prevention of health problems among travelers. In June 2000, a cross-sectional descriptive survey was carried out among travel agents from all travel agencies in Québec. One agent per agency was asked to answer our questions. Data were collected using a 32-item telephone questionnaire. Altogether, 708 travel agents from the 948 agencies contacted answered our questionnaire (participation rate: 75%). Most respondents (81%) believed that the travel agent has a role to play in the prevention of health problems among travelers, especially to recommend that travelers consult a travel clinic before departure. Although over 80% of the agents interviewed mentioned recommending a visit to a travel clinic before an organized tour to Thailand or a backpacking trip in Mexico, less than half said they make the same recommendation for a stay in a seaside resort in Mexico. The majority of respondents were acquainted with the services offered in travel health clinics, and these clinics were the source of travel health information most often mentioned by travel agents. However, nearly 60% of the agents questioned had never personally consulted a travel clinic. When asked about the best way to receive information about travelers' health, more than 40% of respondents favoured receiving information newsletters from public health departments regularly whereas 28% preferred the Internet. Despite the limits of this study, our results should help the public health network better target its interventions aimed to inform travel agents on prevention of health problems among travelers.

  13. A profile of travelers--an analysis from a large swiss travel clinic.

    Science.gov (United States)

    Bühler, Silja; Rüegg, Rolanda; Steffen, Robert; Hatz, Christoph; Jaeger, Veronika K

    2014-01-01

    Globally, the Swiss have one of the highest proportions of the population traveling to tropical and subtropical countries. Large travel clinics serve an increasing number of customers with specific pre-travel needs including uncommon destinations and preexisting medical conditions. This study aims to identify health characteristics and travel patterns of travelers seeking advice in the largest Swiss travel clinic so that tailored advice can be delivered. A descriptive analysis was performed on pre-travel visits between July 2010 and August 2012 at the Travel Clinic of the Institute of Social and Preventive Medicine, University of Zurich, Switzerland. A total of 22,584 travelers sought pre-travel advice. Tourism was the main reason for travel (17,875, 81.5%), followed by visiting friends and relatives (VFRs; 1,715, 7.8%), traveling for business (1,223, 5.6%), and "other reasons" (ie, volunteer work, pilgrimage, study abroad, and emigration; 1,112, 5.1%). The main travel destination was Thailand. In the VFR group, the highest proportions of traveling children (258, 15.1%) and of pregnant or breastfeeding women (23, 3.9%) were observed. Mental disorders were more prominent in VFRs (93, 5.4%) and in travel for "other reasons" (63, 5.7%). The latter stayed for the longest periods abroad; 272 (24.9%) stayed longer than 6 months. VFR travelers received the highest percentage of yellow fever vaccinations (523, 30.5%); in contrast, rabies (269, 24.2%) and typhoid vaccinations (279, 25.1%) were given more often to the "other travel reasons" group. New insights into the characteristics of a selected and large population of Swiss international travelers results in improved understanding of the special needs of an increasingly diverse population and, thus, in targeted preventive advice and interventions. © 2014 International Society of Travel Medicine.

  14. 基于混合遗传算法的中国旅行商问题满意解%Satisfactory Solution-Hybrid Genetic Algorithm of China Travelling Salesman Problem

    Institute of Scientific and Technical Information of China (English)

    王攀; 商海燕; 潘利群; 徐承志

    2000-01-01

    针对组合优化中的旅行商问题,提出了贪心法与遗传算法相结合的混合遗传算法.文中给出了相应步骤并就中国旅行商问题得出满意解,该解优于已报道的结果.

  15. Travel itinerary uncertainty and the pre-travel consultation--a pilot study.

    Science.gov (United States)

    Flaherty, Gerard; Md Nor, Muhammad Najmi

    2016-01-01

    Risk assessment relies on the accuracy of the information provided by the traveller. A questionnaire was administered to 83 consecutive travellers attending a travel medicine clinic. The majority of travellers was uncertain about destinations within countries, transportation or type of accommodation. Most travellers were uncertain if they would be visiting malaria regions. The degree of uncertainty about itinerary potentially impacts on the ability of the travel medicine specialist to perform an adequate risk assessment, select appropriate vaccinations and prescribe malaria prophylaxis. This study reveals high levels of traveller uncertainty about their itinerary which may potentially reduce the effectiveness of their pre-travel consultation. © The Author 2016. Published by Oxford University Press on behalf of International society of travel medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. What proportion of international travellers acquire a travel-related illness? A review of the literature.

    Science.gov (United States)

    Angelo, Kristina M; Kozarsky, Phyllis E; Ryan, Edward T; Chen, Lin H; Sotir, Mark J

    2017-09-01

    As international travel increases, travellers may be at increased risk of acquiring infectious diseases not endemic in their home countries. Many journal articles and reference books related to travel medicine cite that between 22-64% of international travellers become ill during or after travel; however, this information is minimal, outdated and limited by poor generalizability. We aim to provide a current and more accurate estimate of the proportion of international travellers who acquire a travel-related illness. We identified studies via PubMed or travel medicine experts, published between January 1, 1976-December 31, 2016 that included the number of international travellers acquiring a travel-related illness. We excluded studies that focused on a single disease or did not determine a rate based on the total number of travellers. We abstracted information on traveller demographics, trip specifics, study enrollment and follow-up and number of ill travellers and their illnesses. Of 743 studies, nine met the inclusion criteria. The data sources were from North America (four studies) and Europe (five studies). Most travellers were tourists, the most frequent destination regions were Asia and Africa, and the median trip duration ranged from 8-21 days. Six studies enrolled participants at the travellers' pre-travel consultation. All studies collected data through either extraction from the medical record, weekly diaries, or pre- and post-travel questionnaires. Data collection timeframes varied by study. Between 6-87% of travellers became ill across all studies. Four studies provided the best estimate: between 43-79% of travellers who frequently visited developing nations (e.g. India, Tanzania, and Kenya) became ill; travellers most frequently reported diarrhoea. This is the most comprehensive assessment available on the proportion of international travellers that develop a travel-related illness. Additional cohort studies would provide needed data to more precisely

  17. The assessment of collective dose for travellers travelling by water

    International Nuclear Information System (INIS)

    Yue Qingyu; Jiang Ping; Jin Hua

    1992-06-01

    The major contribution to the various radiation exposure received by mankind comes from natural radiation. Some environmental change caused by human beings and some activities of mankind may decrease or increase the radiation exposure level from natural radiation. People travelling by air will receive more exposure dose and by water will receive less. China has about 18000 km coast line and the inland water transportation is very flourishing. According to statistic data from Ministry of Transportation in 1988, the turnover in that year was about 2 x 10 10 man.km. The total number of fisherman for inshore fishing was nearly two million reported by Ministry of Farming, Animal Husbandry and Fishery. We measured 212 points in six typical shipping lines of inshore lines and inland rivers, and the distance was 5625 km. The average natural radiation exposure dose rate received by travellers in each shipping line was calculated. From that the assessment of collective dose equivalent for passengers by water and fishermen was derived. The value is 32.7 man.Sv for passengers and 265.3 man.Sv for fishermen

  18. 41 CFR 301-71.105 - Must we issue a written or electronic travel authorization in advance of travel?

    Science.gov (United States)

    2010-07-01

    ... or electronic travel authorization in advance of travel? 301-71.105 Section 301-71.105 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES AGENCY RESPONSIBILITIES 71-AGENCY TRAVEL ACCOUNTABILITY REQUIREMENTS Travel Authorization § 301-71.105...

  19. Hepatitis B Vaccination Status among Japanese Travelers.

    Science.gov (United States)

    Yaita, Kenichiro; Yahara, Koji; Sakai, Yoshiro; Iwahashi, Jun; Masunaga, Kenji; Hamada, Nobuyuki; Watanabe, Hiroshi

    2017-05-08

    This study clarified the characteristics of travelers who received hepatitis B vaccinations. Subjects were 233 Japanese travelers who visited our clinic prior to travel. We summarized the characteristics of the clients and performed two comparative studies: first, we compared a hepatitis B-vaccinated group with an unvaccinated group; second, we compared a group that had completed the hepatitis B vaccine series with a group that did not complete the series. The hepatitis B vaccine was administered to 152 clients. Factors positively associated with the hepatitis B vaccination (after adjusting for age and sex) included the following: travel for business or travel as an accompanying family member; travel to Asia; travel for a duration of a month or more; and, inclusion of the vaccine in a company or organization's payment plan. Meanwhile, factors negatively associated with the vaccination were travel for leisure or education, and travel to North America or Africa. Among 89 record-confirmed cases, only 53 completed 3 doses. The completion rate was negatively associated with the scheduled duration of travel if it was from a month to less than a year (after adjusting for age and sex). The present study provides a basis for promoting vaccination compliance more vigorously among Japanese adults.

  20. Pediatric travel consultation in an integrated clinic.

    Science.gov (United States)

    Christenson , J C; Fischer , P R; Hale , D C; Derrick , D

    2001-01-01

    In May 1997, a pediatric travel service was created within a larger integrated University-County Health Department international travel clinic. The purpose of the service was to further enhance the travel advice and care provided to children and their parents or guardians. The current study was designed to describe the care of children in this setting and to compare the care of children seen in the Pediatric Travel Service with that of children seen by other providers. All pediatric patients (defined as individuals Mexico, South America, and Southeast Asia. When compared to travelers seen in the Regular Clinic, individuals in the Pediatric Travel Service group were more likely to travel for humanitarian work, and for parental work relocation. Persons in the Regular Clinic were more likely to travel to Mexico and Central America. They were also more likely to travel on vacation and for missionary work or study. Hepatitis B and tetanus-diphtheria booster vaccinations were given more frequently to travelers seen in the Regular Clinic. Also, ciprofloxacin and antimotility agents were more commonly prescribed in this group. No differences were noted in the duration of travel or in the time interval between clinic visit and departure. While general travel advice was considered to be similar in both clinic groups, some differences were observed in the frequency of administration of certain vaccines and prescriptions of medications. These differences were likely due to a difference in age in the two study groups. The high volume and success of the clinic suggest that integrated pediatric and adult travel services in a coordinated setting can be effective.

  1. Dynamics of traveling reaction pulses

    International Nuclear Information System (INIS)

    Dovzhenko, A. Yu.; Rumanov, E. N.

    2007-01-01

    The growth of activator losses is accompanied by the decay of a traveling reaction pulse. In a ring reactor, this propagation threshold is present simultaneously with a threshold related to the ring diameter. The results of numerical experiments with pulses of an exothermal reaction reveal the transition from pulse propagation to a homogeneous hot regime, established regimes with periodic variations of the pulse velocity, and oscillatory decay of the pulse. When the medium becomes 'bistable' as a result of the variation in parameters, this factor does not prevent the propagation of pulses, but leads to changes in the pulse structure

  2. Geometric scaling as traveling waves

    International Nuclear Information System (INIS)

    Munier, S.; Peschanski, R.

    2003-01-01

    We show the relevance of the nonlinear Fisher and Kolmogorov-Petrovsky-Piscounov (KPP) equation to the problem of high energy evolution of the QCD amplitudes. We explain how the traveling wave solutions of this equation are related to geometric scaling, a phenomenon observed in deep-inelastic scattering experiments. Geometric scaling is for the first time shown to result from an exact solution of nonlinear QCD evolution equations. Using general results on the KPP equation, we compute the velocity of the wave front, which gives the full high energy dependence of the saturation scale

  3. Healthy Travel for International Adoptions

    Centers for Disease Control (CDC) Podcasts

    2007-10-22

    The number of international adoptions, many from developing countries, has doubled in the last 10 years. This podcast discusses ways adoptive families can protect their own health and the health of their new children.  Created: 10/22/2007 by National Center for the Prevention, Detection and Control of Infectious Diseases (NCPDCID).   Date Released: 10/24/2007.

  4. Equilibrium double layers in extended Pierce diodes

    International Nuclear Information System (INIS)

    Ciubotariu-Jassy, C.I.

    1992-01-01

    The extended Pierce diode is similar to the standard (or classical) Pierce diode, but has passive circuit elements in place of the short circuit between the electrodes. This device is important as an approximation to real bounded plasma systems. It consists of two parallel plane electrodes (an emitter located at x=0 and a collector located at x=l) and a collisionless cold electron beam travelling between them. The electrons are neutralized by a background of comoving massive ions. This situation is analysed in this paper and new equilibrium double layer (DL) plasma structures are obtained. (author) 6 refs., 3 figs

  5. Medical oxygen and air travel.

    Science.gov (United States)

    Lyznicki, J M; Williams, M A; Deitchman, S D; Howe, J P

    2000-08-01

    This report responds to a resolution that asked the American Medical Association (AMA) to take action to improve airport and airline accommodations for passengers requiring medical oxygen. Information for the report was derived from a search of the MEDLINE database and references listed in pertinent articles, as well as through communications with experts in aerospace and emergency medicine. Based on this information, the AMA Council on Scientific Affairs determined that commercial air travel exposes passengers to altitude-related hypoxia and gas expansion, which may cause some passengers to experience significant symptoms and medical complications during flight. Medical guidelines are available to help physicians evaluate and counsel potential passengers who are at increased risk of inflight hypoxemia. Supplemental oxygen may be needed for some passengers to maintain adequate tissue oxygenation and prevent hypoxemic complications. For safety and security reasons, federal regulations prohibit travelers from using their own portable oxygen system onboard commercial aircraft. Many U.S. airlines supply medical oxygen for use during flight but policies and procedures vary. Oxygen-dependent passengers must make additional arrangements for the use of supplemental oxygen in airports. Uniform standards are needed to specify procedures and equipment for the use of medical oxygen in airports and aboard commercial aircraft. Revision of federal regulations should be considered to accommodate oxygen-dependent passengers and permit them to have an uninterrupted source of oxygen from departure to destination.

  6. Greenhouse Earth: A Traveling Exhibition

    International Nuclear Information System (INIS)

    Booth, W.H.; Caesar, S.

    1992-09-01

    The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a ''demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a ''satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change

  7. Diarrhea in the International Traveler.

    Science.gov (United States)

    Duchini; Rodgers

    1999-06-01

    International travelers to developing countries have a 40% risk of developing a diarrheal illness, usually acute and occasionally chronic. Preventive measures, including diet and lifestyle modifications, are highly recommended but may not be sufficient. Prophylaxis with bismuth subsalicylate or an antimicrobial should be considered in travelers with immunodeficiencies, co-morbid conditions, achlorhydria, or those who cannot afford a loss of time. Oral rehydration is the primary goal of therapy. Bismuth-subsalicylate is a first-line agent for treatment of milder cases with less than three watery bowel movements per day and prominent nausea. Use of an antibiotic is indicated for more severe cases or in the presence of fever, dysentery, or severe dehydration. A short course of a quinolone is highly effective, safe and well tolerated. Antimicrobial resistance among enteropathogens is growing and appropriate therapeutic modifications should be considered according to specific geographic areas. Metronidazole may be empirically added in those cases that do not respond to quinolones. Specific guidelines for particular pathogens are highlighted.

  8. Travel to Asia and traveller's diarrhoea with antibiotic treatment are independent risk factors for acquiring ciprofloxacin-resistant and extended spectrum β-lactamase-producing Enterobacteriaceae-a prospective cohort study.

    Science.gov (United States)

    Reuland, E A; Sonder, G J B; Stolte, I; Al Naiemi, N; Koek, A; Linde, G B; van de Laar, T J W; Vandenbroucke-Grauls, C M J E; van Dam, A P

    2016-08-01

    Travel to (sub)tropical countries is a well-known risk factor for acquiring resistant bacterial strains, which is especially of significance for travellers from countries with low resistance rates. In this study we investigated the rate of and risk factors for travel-related acquisition of extended spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E), ciprofloxacin-resistant Enterobacteriaceae (CIPR-E) and carbapenem-resistant Enterobacteriaceae. Data before and after travel were collected from 445 participants. Swabs were cultured with an enrichment broth and sub-cultured on selective agar plates for ESBL detection, and on plates with a ciprofloxacin disc. ESBL production was confirmed with the double-disc synergy test. Species identification and susceptibility testing were performed with the Vitek-2 system. All isolates were subjected to ertapenem Etest. ESBL and carbapenemase genes were characterized by PCR and sequencing. Twenty-seven out of 445 travellers (6.1%) already had ESBL-producing strains and 45 of 445 (10.1%) travellers had strains resistant to ciprofloxacin before travel. Ninety-eight out of 418 (23.4%) travellers acquired ESBL-E and 130 of 400 (32.5%) travellers acquired a ciprofloxacin-resistant strain. Of the 98 ESBL-E, predominantly Escherichia coli and predominantly blaCTX-M-15, 56% (55/98) were resistant to gentamicin, ciprofloxacin and co-trimoxazole. Multivariate analysis showed that Asia was a high-risk area for ESBL-E as well as CIPR-E acquisition. Travellers with diarrhoea combined with antimicrobial use were significantly at higher risk for acquisition of resistant strains. Only one carbapenemase-producing isolate was acquired, isolated from a participant after visiting Egypt. In conclusion, travelling to Asia and diarrhoea combined with antimicrobial use are important risk factors for acquiring ESBL-E and CIPR-E. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All

  9. Trends and characteristics among HIV-infected and diabetic travelers seeking pre-travel advice.

    Science.gov (United States)

    Elfrink, Floor; van den Hoek, Anneke; Sonder, Gerard J B

    2014-01-01

    The number of individuals with a chronic disease increases. Better treatment options have improved chronic patients' quality of life, likely increasing their motivation for travel. This may have resulted in a change in the number of HIV-infected travelers and/or travelers with Diabetes Mellitus (DM) visiting our travel clinic. We retrospectively analyzed the database of the travel clinic of the Public Health Service Amsterdam, between January 2001 and December 2011 and examined the records for patients with these conditions. Of the 25,000 travelers who consult our clinic annually, the proportion of travelers with HIV or DM has increased significantly. A total of 564 HIV-infected travelers visited our clinic. The mean age was 41 years, 86% were male, 43% visited a yellow fever endemic country and 46.5% had a CD4 count Travelers with low CD4 counts traveled significantly more often to visit friends or relatives. A total of 3704 diabetics visited our clinic. The mean age was 55 years, 52% were male, 27% visited a yellow fever endemic country and 36% were insulin-dependent. Insulin-dependent diabetics traveled more often for work than non-insulin-dependent diabetics. Adequately trained and qualified travel health professionals and up-to-date guidelines for travelers with chronic diseases are of increasing importance. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Travel risk behaviors as a determinants of receiving pre-travel health consultation and prevention.

    Science.gov (United States)

    Shady, Ibrahim; Gaafer, Mohammed; Bassiony, Lamiaa

    2015-01-01

    An estimated 30-60 % of travelers experience an illness while traveling. The incidence of travel-related illness can be reduced by preventive measures such as those provided by the Traveler Health Clinic (THC) in Kuwait. The present study is an analytical comparative study between groups of travelers visiting the THC during the study period (May 2009 - December 2010) and an age- and gender-matched control group of non-visitors (800 people). Both groups completed a modified pre-departure questionnaire. Bivariate analysis revealed that Kuwaitis (68.2 %), those traveling for work (25.3 %) or leisure (59.5 %), those living in camps (20.4 %) or hotels (64.0 %), and those with knowledge of the THC from the media (28.1 %) or other sources (57.3 %), were more likely to be associated with a high frequency of visits to the THC ( p  travelers heading to Africa (47 %) and South America (10 %) visited the THC more than did others ( P  travel, duration of stay, and choice of travel destination are independent predictors of receiving pre-travel consultation from the THC. Nationality, purpose of travel, length of stay, and travel destination are predictors for receiving a pre-travel consultation from the THC.

  11. International double taxation

    OpenAIRE

    Körbl, Hugo

    2012-01-01

    1 Summary This thesis deals with the issue of international double taxation of income and capital and methods for its solution. International double taxation is an issue which states began to deal with in the late 19th century. This interest intensified after the First World War when also the League of Nations (predecessor of the United Nations) began to deal with international double taxation. Most attention the phenomenon of double taxation of income and capital with an international elemen...

  12. 38 CFR 60.5 - Travel.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Travel. 60.5 Section 60.5... TEMPORARY LODGING § 60.5 Travel. As a condition for receiving temporary lodging under this part, a veteran must be required to travel either 50 or more miles, or at least two hours from his or her home to the...

  13. Travel time variability and airport accessibility

    OpenAIRE

    Koster, P.R.; Kroes, E.P.; Verhoef, E.T.

    2010-01-01

    This discussion paper resulted in a publication in Transportation Research Part B: Methodological (2011). Vol. 45(10), pages 1545-1559. This paper analyses the cost of access travel time variability for air travelers. Reliable access to airports is important since it is likely that the cost of missing a flight is high. First, the determinants of the preferred arrival times at airports are analyzed, including trip purpose, type of airport, flight characteristics, travel experience, type of che...

  14. Standardized training in nurse model travel clinics.

    Science.gov (United States)

    Sofarelli, Theresa A; Ricks, Jane H; Anand, Rahul; Hale, Devon C

    2011-01-01

    International travel plays a significant role in the emergence and redistribution of major human diseases. The importance of travel medicine clinics for preventing morbidity and mortality has been increasingly appreciated, although few studies have thus far examined the management and staff training strategies that result in successful travel-clinic operations. Here, we describe an example of travel-clinic operation and management coordinated through the University of Utah School of Medicine, Division of Infectious Diseases. This program, which involves eight separate clinics distributed statewide, functions both to provide patient consult and care services, as well as medical provider training and continuing medical education (CME). Initial training, the use of standardized forms and protocols, routine chart reviews and monthly continuing education meetings are the distinguishing attributes of this program. An Infectious Disease team consisting of one medical doctor (MD) and a physician assistant (PA) act as consultants to travel nurses who comprise the majority of clinic staff. Eight clinics distributed throughout the state of Utah serve approximately 6,000 travelers a year. Pre-travel medical services are provided by 11 nurses, including 10 registered nurses (RNs) and 1 licensed practical nurse (LPN). This trained nursing staff receives continuing travel medical education and participate in the training of new providers. All nurses have completed a full training program and 7 of the 11 (64%) of clinic nursing staff serve more than 10 patients a week. Quality assurance measures show that approximately 0.5% of charts reviewed contain a vaccine or prescription error which require patient notification for correction. Using an initial training program, standardized patient intake forms, vaccine and prescription protocols, preprinted prescriptions, and regular CME, highly trained nurses at travel clinics are able to provide standardized pre-travel care to

  15. Psychological Aspects of Travel Information Presentation

    OpenAIRE

    Dicke-Ogenia, M.

    2012-01-01

    Congestion on road networks causes severe problems in and around large cities. Consequences of congestion include an increase in travel time and travel costs, environmental costs, economic costs, increased energy use and decreased economic growth, reduced travel time reliability, and reduced quality of life. Therefore, mitigation of congestion is deemed necessary. Within the Dutch program “Verkeer en Vervoer” (Traffic and Transport) funded by Connekt/NWO, strategies to mitigate congestion are...

  16. Approach to Immunization for the Traveling Child.

    Science.gov (United States)

    Myers, Angela L; Christenson, John C

    2015-12-01

    Children are traveling to regions of the world that could pose a risk of acquiring diseases such as malaria, dermatosis, and infectious diarrhea. Most of these can be prevented by modifying high-risk behaviors or through the use of medications. Many of these same regions are endemic with diseases that are preventable through vaccination. Clinicians must be able to effectively prepare their pediatric-age travelers for international travel. Preventive education, prophylactic and self-treating medications, and vaccinations are all important components of this preparation. Familiarity with the use of travel vaccines is imperative. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Dinamika Bisnis Travel Umroh Se Kota Pasuruan Di Era Globalisasi

    OpenAIRE

    Masitah, Dewi

    2015-01-01

    This research aims to know how the Ethics and responsibility of PT TRAVEL Umrah conducts its travel business?. This background research of Various motivations variety PT TRAVEL Umrah in implementing its travel business. Is that motivation is not only a business commodity, so causing a few problems related to that Travel, among others, the cheapness of travel so that the number of Umrah pilgrims displaced and not so depart with many reasons such as the visa is not out or travel unclear. This ...

  18. Students' use of social media during the travel process

    OpenAIRE

    Nemec Rudež, Helena; Vodeb, Ksenija

    2015-01-01

    Purpose – The purpose of the study is to explore how students as an important travel segment are involved in social media during the travel process and explore the underlying dimensions of social media use by students during the travel process. Design/methodology/approach – The quantitative research focuses on the students’ use of social media in the three phrases of the travel process – before travel, during travel and after travel separately. Survey instrument was a structured questionna...

  19. Factors Adopting E-Travel Website: The Case of Indonesia

    OpenAIRE

    Vera Pujani; Alfitman; Refdinal Nazir

    2012-01-01

    E-travel is travel agency-s companies employing internet and website as e-commerce context. This study presents numerous initial key factors of electronic travel model based on small travel agencies perspectives. Browsing previous studies related to website travel activities are conducted. Five small travel agencies in Indonesia has been deeply interviewed in case studies. The finding of this research is identifying numerous characteristics and dimension factors and travel website operations ...

  20. Double-slit experiment in momentum space

    Science.gov (United States)

    Ivanov, I. P.; Seipt, D.; Surzhykov, A.; Fritzsche, S.

    2016-08-01

    Young's classic double-slit experiment demonstrates the reality of interference when waves and particles travel simultaneously along two different spatial paths. Here, we propose a double-slit experiment in momentum space, realized in the free-space elastic scattering of vortex electrons. We show that this process proceeds along two paths in momentum space, which are well localized and well separated from each other. For such vortex beams, the (plane-wave) amplitudes along the two paths acquire adjustable phase shifts and produce interference fringes in the final angular distribution. We argue that this experiment can be realized with the present-day technology. We show that it gives experimental access to the Coulomb phase, a quantity which plays an important role in all charged particle scattering but which usual scattering experiments are insensitive to.

  1. Contact frequency, travel time, and travel costs for patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Sørensen, Jan; Linde, Louise; Hetland, Merete Lund

    2014-01-01

    Objectives. To investigate travel time, and travel cost related to contacts with health care providers for patients with rheumatoid arthritis (RA) during a three-month period. Methods. Patient-reported travel time and travel cost were obtained from 2847 patients with RA. Eleven outpatient clinics...... across Denmark recruited patients to the study. Data collected included frequency, travel time and travel costs for contacts at rheumatology outpatient clinics, other outpatient clinics, general practitioners, privately practicing medical specialists, inpatient hospitals and accident and emergency...... and 13 € on travelling per contact, corresponding to a total of 4.6 hours and 56 € during the 3-month period. There was great variation in patient travel time and costs, but no statistically significant associations were found with clinical and sociodemographic characteristics. Conclusion. The results...

  2. Effectiveness of different approaches to disseminating traveler information on travel time reliability. [supporting datasets

    Science.gov (United States)

    2013-11-30

    Travel time reliability information includes static data about traffic speeds or trip times that capture historic variations from day to day, and it can help individuals understand the level of variation in traffic. Unlike real-time travel time infor...

  3. Valuing travel time variability: Characteristics of the travel time distribution on an urban road

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Fukuda, Daisuke

    2012-01-01

    This paper provides a detailed empirical investigation of the distribution of travel times on an urban road for valuation of travel time variability. Our investigation is premised on the use of a theoretical model with a number of desirable properties. The definition of the value of travel time...... variability depends on certain properties of the distribution of random travel times that require empirical verification. Applying a range of nonparametric statistical techniques to data giving minute-by-minute travel times for a congested urban road over a period of five months, we show that the standardized...... travel time is roughly independent of the time of day as required by the theory. Except for the extreme right tail, a stable distribution seems to fit the data well. The travel time distributions on consecutive links seem to share a common stability parameter such that the travel time distribution...

  4. Challenges to providing pre-travel care for travellers visiting friends and relatives: an audit of a specialist travel medicine clinic.

    Science.gov (United States)

    Rowe, Kate; Chaves, Nadia; Leder, Karin

    2017-09-01

    Travellers visiting friends and relatives (VFRs) often have complex pre-travel needs. We identified the characteristics, destinations, vaccinations and pre-travel advice provided to VFRs and compared these with non-VFR travellers. The significant differences we found suggest that future research should focus on improving the uptake of recommended interventions in VFR travellers. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  5. A travel clinic in your office: grow your practice and protect international travelers.

    Science.gov (United States)

    Kirsch, Michael

    2009-01-01

    Medical practices today face economic challenges from declining reimbursements and rising overhead costs. Physicians need to develop new income sources to invigorate their practices and remain viable. Travel medicine-advising and immunizing international travelers-is a rapidly growing specialty in the United States that generates substantial cash reimbursements and professional satisfaction. Travel Clinics of America, a physician-operated company, specializes in helping physicians to incorporate travel medicine into their existing practices.

  6. A process model of voluntary travel behavior modification and effects of Travel Feedback Programs (TFPs)

    OpenAIRE

    Taniguchi, Ayako

    2007-01-01

    This study tested an integrated process model of travel behavior modification. We used a model that combined the theory of planned behavior (TPB), norm activation theory (NAT), a theory of implementation intention, and theories of habit. To test the integrated model, we used panel data (n = 208) obtained before and after travel feedback programs (TFPs); the TFP is a communication program aimed at voluntary travel behavior modification, from automobile use to non-auto means of travel such as p...

  7. The Development of Independent Travel in China in the Future and Travel Agents’ Coping Strategies

    OpenAIRE

    Pan, Yulu

    2010-01-01

    Abstract The purpose of this research is to understand the general trend of independent travel in China from tourists’ perspectives and what strategies travel agents should adopt to cope with the increased independent travel. This project is based on both primary research and secondary research. Quantitative and qualitative data are collected and analyzed for deeply exploration about independent travel in order to understand tourists’ attitudes, expectations and perspectives. By this w...

  8. Travel mode choice and travel satisfaction : bridging the gap between decision utility and experienced utility

    OpenAIRE

    De Vos, Jonas; Mokhtarian, Patricia L; Schwanen, Tim; Van Acker, Veronique; Witlox, Frank

    2016-01-01

    Over the past decades research on travel mode choice has evolved from work that is informed by utility theory, examining the effects of objective determinants, to studies incorporating more subjective variables such as habits and attitudes. Recently, the way people perceive their travel has been analyzed with transportation-oriented scales of subjective wellbeing, and particularly the satisfaction with travel scale. However, studies analyzing the link between travel mode choice (i.e., decisio...

  9. Exploring disagreement prevention and resolution in travel decision-making of young Chinese travellers

    OpenAIRE

    Song, Hanqun; Sparks, Beverley; Wang, Ying

    2017-01-01

    The young Chinese travel market is becoming increasingly significant in domestic and international tourism. However, there is limited research on the market. This study examines the decision-making processes of young Chinese travellers, with a particular interest in disagreement prevention and resolution. On the basis of interviews with 25 young Chinese travellers, this study found that while a small number of travellers did not perceive any disagreement, or did not voice their disagreement, ...

  10. Residential self-selection and travel : The relationship between travel-related attitudes, built environment characteristics and travel behaviour

    NARCIS (Netherlands)

    Bohte, W.

    2010-01-01

    Most Western national governments aim to influence individual travel patterns – at least to some degree – through spatial planning in residential areas. Nevertheless, the extent to which the characteristics of the built environment influence travel behaviour remains the subject of some debate among

  11. Double layers in space

    International Nuclear Information System (INIS)

    Carlqvist, P.

    1982-07-01

    For more than a decade it has been realised that electrostatic double layers are likely to occur in space. We briefly discuss the theoretical background of such double layers. Most of the paper is devoted to an account of the observational evidence for double layers in the ionosphere and magnetosphere of the Earth. Several different experiments are reviewed including rocket and satellite measurements and ground based observations. It is concluded that the observational evidence for double layers in space is very strong. The experimental results indicate that double layers with widely different properties may exist in space. (Author)

  12. Double layers in space

    International Nuclear Information System (INIS)

    Carlqvist, P.

    1982-01-01

    For more than a decade it has been realised that electrostatic double layers are likely to occur in space. The author briefly discusses the theoretical background of such double layers. Most of the paper is devoted to an account of the observational evidence for double layers in the ionosphere and magnetosphere of the Earth. Several different experiments are reviewed including rocket and satellite measurements and ground based observations. It is concluded that the observational evidence for double layers in space is very strong. The experimental results indicate that double layers with widely different properties may exist in space. (Auth.)

  13. Double-double effect and coordination number

    International Nuclear Information System (INIS)

    Mioduski, T.

    1992-01-01

    The original method of interpretation together with its theoretical foundations is developed, making it possible to use location and direction of the double-double (tetrad) effect within the Ln and An series to determine the coordination number (CN) complexes of the f-block elements. The method is applied for potentiometric and radiometric equilibrium studies. It has been pointed and that the decisive factor for the direction of the double-double effect in the case of the Gibbs energy variations is a difference in the CN of the f-element ion between the reaction product complex and that for the reaction substrate the ''regular'' effect for a given tetrad is accompanied by decrease in the CN while the ''reverse'' effect by increase in the CN. (author). 122 refs, 5 tabs, 8 figs

  14. Trends and characteristics among HIV-infected and diabetic travelers seeking pre-travel advice

    NARCIS (Netherlands)

    Elfrink, Floor; van den Hoek, Anneke; Sonder, Gerard J. B.

    2014-01-01

    The number of individuals with a chronic disease increases. Better treatment options have improved chronic patients' quality of life, likely increasing their motivation for travel. This may have resulted in a change in the number of HIV-infected travelers and/or travelers with Diabetes Mellitus (DM)

  15. The New England travel market: generational travel patterns, 1979 to 1996

    Science.gov (United States)

    Rod Warnick

    2002-01-01

    Generations of travelers who select New England as a primary destination are examined over time from the years of 1979 through 1996 and the analysis serves to update an earlier review of generational travel patterns of the region (Warnick, 1994). Changes in travel patterns are noted by overall adjusted annual change rates by demographic and geographic regions of...

  16. Examining the Relationship between Online Travel Agency Information and Traveler Destination Transaction Decisions

    Science.gov (United States)

    Yerby, Dennis

    2012-01-01

    The purpose of this quantitative study was to examine the role that available Online Travel Agency (OTA) destination information may have on a traveler's perceptions and intent in transaction decisions with that respective OTA. Specifically, this research examined a pleasure traveler's transaction perceptions and intentions with an OTA…

  17. 75 FR 24434 - Federal Travel Regulation (FTR); Transportation in Conjunction With Official Travel and Relocation

    Science.gov (United States)

    2010-05-05

    ...-0010, sequence 1] RIN 3090-AJ02 Federal Travel Regulation (FTR); Transportation in Conjunction With Official Travel and Relocation AGENCY: Office of Governmentwide Policy, General Services Administration (GSA). ACTION: Final rule. SUMMARY: This final rule amends the Federal Travel Regulation (FTR), by...

  18. You, too, can be an international medical traveler: Reading medical travel guidebooks

    NARCIS (Netherlands)

    Ormond, M.E.; Sothern, M.

    2012-01-01

    Drawing on literature on self-help and travel guide writing, this paper interrogates five international medical travel guidebooks aimed at encouraging American and British audiences to travel abroad to purchase medical care. These guidebooks articulate a three-step self-help “program” to produce a

  19. The Concept of Travel Medicine and the Actual Situation of Travel-Related Illnesses.

    Science.gov (United States)

    Tunalı, Varol; Turgay, Nevin

    2017-06-01

    Travel medicine defines all diseases and medical situations that are related to travel. Travel medicine comprises infectious diseases, traumas, altitude sickness, sun burns, embolisms, jet lag, and many more travel-related situations. With the increasing possibility and ease of travel, the number of people who have travelled internationally has exceeded 1.13 billion in 2014, and the revenues of international travel have exceeded 1.25 trillion dollars. With every passing day, international travels are shifting toward the developing countries and to more exotic regions of the world, and travelers tend to be more adventurous and daring, thereby increasing risky behaviors during travels. Traveling plays an important role in transmitting infections such as Zika virus infection, Ebola, avian flu, severe acute respiratory syndrome, Chikungunya, and dengue fever and is the principal reason for the epidemics of these types of infections on a global scale. With this background, we suggest that travel medicine is an important but "neglected" medical discipline as the discipline of Parasitology itself like most parasitic diseases.

  20. 25 CFR 700.533 - Restrictions affecting travel and travel expense reimbursement.

    Science.gov (United States)

    2010-04-01

    ... having or seeking business with the Commission. (d) Commission employees traveling on official business, as well as employees traveling on personal business, may not accept the use of private airplanes... official business, provided administrative procedures have been followed in making the travel arrangements. ...

  1. [Ciguatera poisoning in Spanish travellers].

    Science.gov (United States)

    Gascón, Joaquim; Macià, Maria; Oliveira, Inés; Corachán, Manuel

    2003-05-31

    Ciguatera poisoning appears after ingestion of contaminated fish from tropical coral reefs. Due to the diversity of clinical symptoms and the absence of a specific test in humans, the diagnosis is often difficult. A retrospective study of 10 patients consulting for a clinical and epidemiological picture compatible with ciguatera poisoning after a trip to tropical countries between 1993 and 2000. Most infections but one were acquired in the Caribbean area and there were 8 females. Clinical manifestations started within the first 24 hours after fish ingestion. Chief symptoms were diarrhea and nausea, followed by neurological symptoms, mainly limbs paresthesias that persisted for several weeks. The severity of clinical symptoms was variable and not related to age or initial symptoms. Ciguatera poisoning has to be considered in the diagnosis of acute gastroenteritis affecting travellers to tropical areas.

  2. The interactive surrogate travel system.

    Science.gov (United States)

    Nakajima, I; Ichimura, A; Juzoji, H; Mugita, K

    1999-01-01

    The Interactive Surrogate Travel (IST) system is based on the super-miniaturized system of virtual technology, Cave Automatic Virtual Environment (CAVE). Using bilateral virtual reality (VR-to-VR) communications, IST enables the testing of subjects via interactive communications. It appears that IST will find practical applications in the near future. We examined the utility of IST in medical treatment and psychiatric tests. Psychiatric symptoms reflect human pathos, which in turn are greatly influenced by culture. If these culture-bound symptoms can be adequately communicated between providers and clients of different cultures, we can develop effective telepsychiatric services across different societies and cultures. IST requires high-speed transmission and gigabyte circuits. A pilot project tested the utility of IST (through the use of optical fiber communications on earth) as a basis for experiments via the Gigabit satellite, to be launched in the year 2002.

  3. Surgical travellers: tapestry to Bayeux.

    Science.gov (United States)

    Hedley-Whyte, John; Milamed, Debra R

    2014-09-01

    The planning for surgery in war was revisited in 1937 when Ian Fraser was elected a member of the Surgical Travellers. At their 1938 Surgical Travellers meeting in Vienna, Ian and Eleanor Fraser were evicted from their hotel room by the Nazis. The 1939 meeting in Belfast discussed the organization of surgery and the conduct of Emergency Medical Service Hospitals in the United Kingdom; the vast majority were to be under civilian government and military control. From 1943 lengthy and informative organizational meetings were held at least monthly under the chairmanship of Sir Alexander Hood, KBE, Head of the RAMC. Surgical Consultants, now Major Generals, Brigadiers or Full Colonels in the British and U.S. Armies stationed in the UK, prepared for the invasion of Europe. The allocation of medical, surgical, nursing and auxiliary responsibilities was delineated. Liaison with the RAF and US Army Air Force was close as it was with the proposed leaders, Ulstermen Brooke and Montgomery. Montgomery chose Arthur Porritt as Surgeon in Chief to Supreme Headquarters Allied Expeditionary Force (SHAEF), and Eisenhower, General Albert W. Kenner. Just after D-Day, Porritt met Ian Fraser, who had waded in on Arromanches Beach. The triage and evacuation plans for Allied casualties had been controversial, particularly as regards Landing Ship Tanks (LSTs). The dispute with the Hood-selected surgeons on one side, against medical and surgical deployment of LSTs, and Admiral Ernest King and Winston Churchill on the other, favouring LST use for surgery and evacuation. King and Churchill were correct but total Allied air superiority allowed wide use of many of the Allies' Dakotas; 10,000 DC-3s were eventually in service. Supported by forty Allied combat planes to each Luftwaffe, the dispute about Landing Ship Tank use in about a fortnight became moot. The multifaceted role of the Princess Royal in the Emergency Medical Services of the United Kingdom and her close liaison with the Consultant

  4. Limiting Behavior of Travelling Waves for the Modified Degasperis-Procesi Equation

    Directory of Open Access Journals (Sweden)

    Jiuli Yin

    2014-01-01

    Full Text Available Using an improved qualitative method which combines characteristics of several methods, we classify all travelling wave solutions of the modified Degasperis-Procesi equation in specified regions of the parametric space. Besides some popular exotic solutions including peaked waves, and looped and cusped waves, this equation also admits some very particular waves, such as fractal-like waves, double stumpons, double kinked waves, and butterfly-like waves. The last three types of solutions have not been reported in the literature. Furthermore, we give the limiting behavior of all periodic solutions as the parameters trend to some special values.

  5. Safe and Healthy Travel to China

    Centers for Disease Control (CDC) Podcasts

    2008-10-09

    In this podcast, Dr. Phyllis Kozarsky, CDC Travel Medicine expert, discusses what travelers should do to ensure a safe and healthy trip to China.  Created: 10/9/2008 by National Center for Preparedness, Detection, and Control of Infectious Diseases (NCPDCID), Division of Global Migration and Quarantine (DGMQ).   Date Released: 10/9/2008.

  6. Home Education, School, Travellers and Educational Inclusion

    Science.gov (United States)

    D'Arcy, Kate

    2014-01-01

    The difficulties Traveller pupils experience in school are well documented. Yet those in home educating go unreported. Monk suggests this is because some groups are overlooked; that gypsies and Travellers are often not perceived as home educators. This article highlights how the move to home education is seldom a free choice for Traveller…

  7. Regularity and irreversibility of weekly travel behavior

    NARCIS (Netherlands)

    Kitamura, R.; van der Hoorn, A.I.J.M.

    1987-01-01

    Dynamic characteristics of travel behavior are analyzed in this paper using weekly travel diaries from two waves of panel surveys conducted six months apart. An analysis of activity engagement indicates the presence of significant regularity in weekly activity participation between the two waves.

  8. Beyond Europe: The New Student Travel

    Science.gov (United States)

    Deresiewicz, William

    2009-01-01

    The academic year has ended, and over the past few weeks, thousands of students have traveled abroad for the summer or the first year after college. However, students aren't heading abroad in the same direction, or the same spirit, that their parents or grandparents did. This article examines why the patterns of student travel has changed.

  9. Travel medicine : knowledge, attitude, practice and immunisation

    NARCIS (Netherlands)

    Roukens, Anna Helena Elvire

    2010-01-01

    In an epoch where every generation travels more frequently and at longer distances than the previous generation, with a mean increase of 30 million travellers per year from 1995 until today, physicians throughout the world are confronted with new diseases. In absolute numbers, this implies that each

  10. Travel assistance device deployment to transit agencies.

    Science.gov (United States)

    2010-08-01

    The ability to travel where and when one desires is a basic requirement for independent living that most people take for granted. To travel independently, a transit rider practices at least 23 skills including finding the route, arriving at the corre...

  11. Collective Travel Planning in Spatial Networks

    KAUST Repository

    Shang, Shuo; Chen, Lisi; Wei, Zhewei; Jensen, Christian; Wen, Ji-Rong; Kalnis, Panos

    2015-01-01

    meeting points. When multiple travelers target the same destination (e.g., a stadium or a theater), they may want to assemble at meeting points and then go together to the destination by public transport to reduce their global travel cost (e.g., energy

  12. OPEN SPACE ALLOCATION AND TRAVEL COSTS

    OpenAIRE

    Kovacs, Kent F.

    2003-01-01

    The gain from dividing parks into smaller pieces to reduce travel costs is weighed against the loss in services the parks provide since they are smaller. The optimal number of parks is dependent on whether travel costs are concentrated in parts of the town.

  13. Can Electricity Powered Vehicles Serve Traveler Needs?

    Directory of Open Access Journals (Sweden)

    Jianhe Du

    2013-06-01

    Full Text Available Electric vehicles (EV, Hybrid Electric Vehicles (HEV or Plug-in Hybrid Electric Vehicles (PHEV are believed to be a promising substitute for current gas-propelled vehicles. Previous research studied the attributes of different types of EVs and confirmed their advantages. The feasibility of EVs has also been explored using simulation, retrospective survey data, or a limited size of field travel data. In this study, naturalistic driving data collected from more than 100 drivers during one year are used to explore naturalistic driver travel patterns. Typical travel distance and time and qualified dwell times (i.e., the typical required EV battery recharging time between travels as based on most literature findings are investigated in this study. The viability of electric cars is discussed from a pragmatic perspective. The results of this research show that 90 percent of single trips are less than 25 miles; approximately 70 percent of the average annual daily travel is less than 60 miles. On average there are 3.62 trips made between four-hour dwell times as aggregated to 60 minutes and 50 miles of travel. Therefore, majority of trips are within the travel range provided by most of the currently available EVs. A well-organized schedule of recharging will be capable of covering even more daily travels.

  14. Gibbon travel paths are goal oriented.

    Science.gov (United States)

    Asensio, Norberto; Brockelman, Warren Y; Malaivijitnond, Suchinda; Reichard, Ulrich H

    2011-05-01

    Remembering locations of food resources is critical for animal survival. Gibbons are territorial primates which regularly travel through small and stable home ranges in search of preferred, limited and patchily distributed resources (primarily ripe fruit). They are predicted to profit from an ability to memorize the spatial characteristics of their home range and may increase their foraging efficiency by using a 'cognitive map' either with Euclidean or with topological properties. We collected ranging and feeding data from 11 gibbon groups (Hylobates lar) to test their navigation skills and to better understand gibbons' 'spatial intelligence'. We calculated the locations at which significant travel direction changes occurred using the change-point direction test and found that these locations primarily coincided with preferred fruit sources. Within the limits of biologically realistic visibility distances observed, gibbon travel paths were more efficient in detecting known preferred food sources than a heuristic travel model based on straight travel paths in random directions. Because consecutive travel change-points were far from the gibbons' sight, planned movement between preferred food sources was the most parsimonious explanation for the observed travel patterns. Gibbon travel appears to connect preferred food sources as expected under the assumption of a good mental representation of the most relevant sources in a large-scale space.

  15. International Development Research Centre Corporate Policy Travel

    International Development Research Centre (IDRC) Digital Library (Canada)

    André Lavoie

    manage and control their business travel-related expenses. 3. ... is paid by IDRC funds (internal or external) — i.e. contractors, participants, interviewees and .... be responsible for providing the Designated Travel Agency with any information ... The Manager, Corporate Accounting (Finance and Administration Division) shall:.

  16. “All Inclusive” Package Travel

    Directory of Open Access Journals (Sweden)

    Nicola Soldati

    2011-01-01

    Full Text Available Travel and tourism contracts are regulated under Articles from 82 to 100 of the Italian Consumer Code. Those articles are specifically dedicated to the regulation of tourist services, providing an accurate and precise definition of "tourist packages". This paper presents a study of travel and tourism under Italian law.

  17. Parametric form of QCD travelling waves

    OpenAIRE

    Peschanski, R.

    2005-01-01

    We derive parametric travelling-wave solutions of non-linear QCD equations. They describe the evolution towards saturation in the geometric scaling region. The method, based on an expansion in the inverse of the wave velocity, leads to a solvable hierarchy of differential equations. A universal parametric form of travelling waves emerges from the first two orders of the expansion.

  18. Clostridium difficile infection in returning travellers

    NARCIS (Netherlands)

    Michal Stevens, A.; Esposito, Douglas H.; Stoney, Rhett J.; Hamer, Davidson H.; Flores-Figueroa, Jose; Bottieau, Emmanuel; Connor, Bradley A.; Gkrania-Klotsas, Effrossyni; Goorhuis, Abraham; Hynes, Noreen A.; Libman, Michael; Lopez-Velez, Rogelio; McCarthy, Anne E.; von Sonnenburg, Frank; Schwartz, Eli; van Genderen, Perry J. J.; Scott Benson, L.; Leung, Daniel T.

    2017-01-01

    There is increasing recognition of the contribution of community-acquired cases to the global burden of Clostridium difficile infection (CDI). The epidemiology of CDI among international travellers is poorly understood, and factors associated with international travel, such as antibiotic use and

  19. Travel time variability and airport accessibility

    NARCIS (Netherlands)

    Koster, P.R.; Kroes, E.P.; Verhoef, E.T.

    2011-01-01

    We analyze the cost of access travel time variability for air travelers. Reliable access to airports is important since the cost of missing a flight is likely to be high. First, the determinants of the preferred arrival times at airports are analyzed. Second, the willingness to pay (WTP) for

  20. Cybermediation in the Tourism and Travel Industries

    Science.gov (United States)

    Killion, Les

    Travel and tourism are second only to pornography in adopting Internet-based technologies to intermediate between those supplying the total travel experience, and those seeking to satisfy leisure needs by engaging in tourism. From Thomas Cook in the 1800s, traditional ‘travel trade networks’ have provided the components of the travel experience: transport, accommodation and attractions. However, the Internet has encouraged customer self-service, and on-going debate regarding the future of traditional travel trade intermediaries. The intermediation debate suggests the emergence of ‘hybrid’ intermediation systems combining customer self-service with face-to-face customer contacts characteristic of traditional travel agents. A focus group investigation identified profiles and motives of customers using the Internet to make holiday arrangements. Potential cost savings are a primary motivation for customer self-service. Using the Internet for travel and tourism is becoming commonplace among older travellers as well as younger people. In gathering information before making holiday decisions, potential tourists also engage in a Web 2.0 environment where family and friends, not established intermediaries, provide reliable and authentic information via their individual blogs.

  1. 78 FR 50340 - Travelers' Information Stations

    Science.gov (United States)

    2013-08-19

    ... conveyed through advertising.'' Some broadcasters contended that this would siphon off advertising revenues...-emergency, non-travel-related information would dilute the effectiveness of TIS in assisting travelers and... the field strength of TIS stations may ``not exceed 2 mV/m when measured with a standard strength...

  2. 20 CFR 416.1498 - What travel expenses are reimbursable.

    Science.gov (United States)

    2010-04-01

    ... necessary, to the coach fare for air travel between the specified travel points involved unless first-class... same two points. “Total cost” includes the cost for all the authorized travelers who travel in the same... under this section for travel to the hearing site from any point within the geographic area of the...

  3. 41 CFR 301-30.1 - What is emergency travel?

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false What is emergency travel? 301-30.1 Section 301-30.1 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES ALLOWABLE TRAVEL EXPENSES 30-EMERGENCY TRAVEL § 301-30.1 What is...

  4. 29 CFR 785.39 - Travel away from home community.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Travel away from home community. 785.39 Section 785.39... Principles Traveltime § 785.39 Travel away from home community. Travel that keeps an employee away from home overnight is travel away from home. Travel away from home is clearly worktime when it cuts across the...

  5. 29 CFR 776.12 - Employees traveling across State lines.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Employees traveling across State lines. 776.12 Section 776... Engaging âin Commerceâ § 776.12 Employees traveling across State lines. Questions are frequently asked as... questions arise are those of traveling service men, traveling buyers, traveling construction crews...

  6. 5 CFR 550.1404 - Creditable travel time.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Creditable travel time. 550.1404 Section... ADMINISTRATION (GENERAL) Compensatory Time Off for Travel § 550.1404 Creditable travel time. (a) General. Subject... off for time in a travel status if— (1) The employee is required to travel away from the official duty...

  7. Good health abroad a traveller's handbook

    CERN Document Server

    Jopling, W H

    2013-01-01

    Good Health Abroad: A Traveller's Handbook guides travelers of possible risks to health, comfort and peace of mind encountered abroad. It discusses the steps to be taken before departure, during the journey, and upon arrival of the tourist. It addresses the measures to protect the health of the individual. Some of the topics covered in the book are the medical and dental check-up; active immunization; vaccination against smallpox, yellow fever, and cholera; optional vaccinations in regions of the world; optional vaccinations which are restricted to special categories of travelers; anti-glare precautions; and pre-travel exercises. The definition of acclimatization is covered. The medical, visa, and currency requirements are discussed. The text describes the clothing for warm, temperate, and cold climates. A study of the travel sickness, postural oedema, package cruises, and survival at sea are presented. A chapter is devoted to the food, water, heat effects abroad. Another section focuses on the accidental hyp...

  8. Travel fosters tool use in wild chimpanzees.

    Science.gov (United States)

    Gruber, Thibaud; Zuberbühler, Klaus; Neumann, Christof

    2016-07-19

    Ecological variation influences the appearance and maintenance of tool use in animals, either due to necessity or opportunity, but little is known about the relative importance of these two factors. Here, we combined long-term behavioural data on feeding and travelling with six years of field experiments in a wild chimpanzee community. In the experiments, subjects engaged with natural logs, which contained energetically valuable honey that was only accessible through tool use. Engagement with the experiment was highest after periods of low fruit availability involving more travel between food patches, while instances of actual tool-using were significantly influenced by prior travel effort only. Additionally, combining data from the main chimpanzee study communities across Africa supported this result, insofar as groups with larger travel efforts had larger tool repertoires. Travel thus appears to foster tool use in wild chimpanzees and may also have been a driving force in early hominin technological evolution.

  9. [Vaccinations and malaria prophylaxis for international travelers].

    Science.gov (United States)

    Alberer, Martin; Löscher, Thomas

    2015-05-01

    The prevention of infectious diseases by vaccination and by counselling about malaria prophylaxis is a central aspect of travel medicine. Besides mandatory vaccinations required for entry to certain countries various vaccinations may be indicated depending on destination and type of travel as well as on individual risks of the traveler. In addition, pre-travel counselling should always include a check-up of standard vaccinations. Protection against mosquito bites is the basis of malaria prophylaxis. The addition of chemoprophylaxis is warranted in high risk areas. When regular chemoprophylaxis is not applied it is recommended to carry an appropriate antimalarial drug which can be used for emergency stand-by treatment in case of unexplained fever and when medical attention is not available within 24 hours. Travelers should realize that self-treatment is a first-aid measure and that they should still seek medical advice as soon as possible. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Personal security a guide for international travelers

    CERN Document Server

    Spencer, Tanya

    2013-01-01

    Personal Security: A Guide for International Travelers provides the perfect mix of lessons-learned, tools, and recommendations from experts so that readers can personalize their own approach to managing travel risks. If followed, the information provided will allow readers to get out and experience the local culture while still traveling safely.-Bernie Sullivan, Director Global Security, Hanesbrands Inc....a must-have for any traveler. Having worked in South and Southeast Asia, I know the advice provided in the book holds the key to keeping safe, avoiding dangerous situations, and managing threats when they occur. The book's methodological framework, combined with the author's extensive experience and hands-on knowledge, provide very practical and useful advice.-Kathrine Alexandrowiz, Independent consultant at Kathalyst, former coordinator for the "Regional Risk Management Project for NGOs in Asia Pacific" (ECHO)... a go-to guide for all travelers irrespective of mission or purpose. An excellent piece of work...

  11. Substituting telecommunications for travel - Feasible or desirable

    Science.gov (United States)

    Van Vleck, E. M.

    1974-01-01

    This paper reviews recent advances in telecommunications and examines the detailed structure of travel to estimate the feasibility of substituting telecommunications for various travel objectives. The impact of travel is analyzed from a social, economic, energy, and pollution standpoint to assess the desirability of substitution. Perhaps 35-50% of the nation's travel could, in theory, be replaced by very advanced telecommunications (such as a much improved large-screen teleconferencing network), but public resistance would be massive. Much economic dislocation would result since, for example, over 25% of retail sales are travel-related. The energy savings would be modest since only 25% of the nation's energy is consumed by transportation. However, all pollution would be reduced substantially since transportation accounts for 75% of the carbon monoxide, 60% of the hydrocarbon, and 55% of the nitrogen oxide pollution in the nation. Problems related to the implementation of large-scale substitution are discussed.

  12. International travel patterns and travel risks for stem cell transplant recipients.

    Science.gov (United States)

    Mikati, Tarek; Griffin, Kenneth; Lane, Dakotah; Matasar, Matthew; Shah, Monika K

    2015-01-01

    Stem cell transplantation (SCT) is being increasingly utilized for multiple medical illnesses. However, there is limited knowledge about international travel patterns and travel-related illnesses of stem cell transplant recipients (SCTRs). An observational cross-sectional study was conducted among 979 SCTRs at Memorial Sloan Kettering Cancer Center using a previously standardized and validated questionnaire. International travel post SCT, pre-travel health advice, exposure risks, and travel-related illnesses were queried. A total of 516 SCTRs completed the survey (55% response rate); of these, 40% were allogeneic SCTRs. A total of 229 (44.3%) respondents reported international travel outside the United States and Canada post SCT. The international travel incidence was 32% [95% confidence interval CI 28-36] within 2 years after SCT. Using multivariable Cox regression analysis, variables significantly associated with international travel within first 2 years after SCT were history of international travel prior to SCT [hazard ratio (HR) = 5.3, 95% CI 2.3-12.0], autologous SCT (HR = 2.6, 95% CI 1.6-2.8), foreign birth (HR = 2.3, 95% CI 1.5-3.3), and high income (HR = 2.0, 95% CI 1.8-3.7). During their first trip, 64 travelers (28%) had traveled to destinations that may have required vaccination or malaria chemoprophylaxis. Only 56% reported seeking pre-travel health advice. Of those who traveled, 16 travelers (7%) became ill enough to require medical attention during their first trip after SCT. Ill travelers were more likely to have visited high-risk areas (60 vs 26%, p = 0.005), to have had a longer mean trip duration (24 vs 12 days, p = 0.0002), and to have visited friends and relatives (69 vs 21%, p travel was common among SCTRs within 2 years after SCT and was mainly to low-risk destinations. Although the overall incidence of travel-related illnesses was low, certain subgroups of travelers were at a significantly higher risk. Pre-travel

  13. Post-infectious sequelae of travelers' diarrhea.

    Science.gov (United States)

    Connor, Bradley A; Riddle, Mark S

    2013-01-01

    Travelers' diarrhea (TD) has generally been considered a self-limited disorder which resolves more quickly with expeditious and appropriate antibiotic therapy given bacteria are the most frequently identified cause. However, epidemiological, clinical, and basic science evidence identifying a number of chronic health conditions related to these infections has recently emerged which challenges this current paradigm. These include serious and potentially disabling enteric and extra-intestinal long-term complications. Among these are rheumatologic, neurologic, gastrointestinal, renal, and endocrine disorders. This review aims to examine and summarize the current literature pertaining to three of these post-infectious disorders: reactive arthritis, Guillain-Barré syndrome, and post-infectious irritable bowel syndrome and the relationship of these conditions to diarrhea associated with travel as well as to diarrhea associated with gastroenteritis which may not be specifically travel related but relevant by shared microbial pathogens. It is hoped this review will allow clinicians who see travelers to be aware of these post-infectious sequelae thus adding to our body of knowledge in travel medicine. Data for this article were identified by searches of PubMed and MEDLINE, and references from relevant articles using search terms "travelers' diarrhea" "reactive arthritis" "Guillain-Barré syndrome" "Post-Infectious Irritable Bowel Syndrome." Abstracts were included when related to previously published work. A review of the published literature reveals that potential consequences of travelers' diarrhea may extend beyond the acute illness and these post-infectious complications may be more common than currently recognized. In addition since TD is such a common occurrence it would be helpful to be able to identify those who might be at greater risk of post-infectious sequelae in order to target more aggressive prophylactic or therapeutic approaches to such individuals. It is

  14. The assessment of collective dose for travellers travelling by water

    International Nuclear Information System (INIS)

    Yue Qingyu; Jian Ping; Jin Hua

    1994-01-01

    The major contribution to various radiation exposure received by mankind comes from natural radiation. Some environmental change caused by human beings and some activities of mankind may decrease or increase the radiation exposure level from natural radiation. China has about 18000 km coast line and the inland water transportation is very flourishing. According to statistic data from Ministry of Transportation in 1988, the turnover in that year was about 2 x 10 10 man·km. The total number of fisherman for inshore fishing was nearly two millions reported by Ministry of Farming, Animal Husbandry and Fishery. We measured exposure dose rates over 212 points in six typical shipping lines of inshore lines and inland rivers, and the distance was 5625 km. The average natural radiation exposure dose rate received by travellers in each shipping line was calculated. From that the assessment of collective dose equivalent for passengers by water and fishermen was derived. The value is 32.7 man·Sv for passengers and 265.3 man·Sv for fishermen

  15. Travel Behavior Change in Older Travelers: Understanding Critical Reactions to Incidents Encountered in Public Transport.

    Science.gov (United States)

    Sundling, Catherine

    2015-11-18

    Accessibility of travel may be better understood if psychological factors underlying change in travel behavior are known. This paper examines older (65+) travelers' motives for changing their travel behavior. These changes are grounded in critical incidents earlier encountered in public-transport travel. A scientific framework is developed based on cognitive and behavioral theory. In 29 individual interviews, travelers' critical reactions (i.e., cognitive, emotional, and/or behavioral) to 77 critical incidents were examined. By applying critical incident technique (CIT), five reaction themes were identified that had generated travel-behavior change: firm restrictions, unpredictability, unfair treatment, complicated trips, and earlier adverse experiences. To improve older travelers' access to public transport, key findings were: (a) service must be designed so as to strengthen the feeling of being in control throughout the journey; (b) extended personal service would increase predictability in the travel chain and decrease travel complexity; consequently, (c) when designing new services and making effective accessibility interventions, policy makers should consider and utilize underlying psychological factors that could direct traveler behavior.

  16. Contact Frequency, Travel Time, and Travel Costs for Patients with Rheumatoid Arthritis

    Directory of Open Access Journals (Sweden)

    Jan Sørensen

    2014-01-01

    Full Text Available Objectives. To investigate travel time, and travel cost related to contacts with health care providers for patients with rheumatoid arthritis (RA during a three-month period. Methods. Patient-reported travel time and travel cost were obtained from 2847 patients with RA. Eleven outpatient clinics across Denmark recruited patients to the study. Data collected included frequency, travel time and travel costs for contacts at rheumatology outpatient clinics, other outpatient clinics, general practitioners, privately practicing medical specialists, inpatient hospitals and accident and emergency departments. Results. Over a 3-month period, patients with RA had on average 4.4 (sd 5.7 contacts with health care providers, of which 2.8 (sd 4.0 contacts were with rheumatology outpatient clinics. Private car and public travel were the most frequent modes of travel. The average patient spent 63 minutes and 13 € on travelling per contact, corresponding to a total of 4.6 hours and 56 € during the 3-month period. There was great variation in patient travel time and costs, but no statistically significant associations were found with clinical and sociodemographic characteristics. Conclusion. The results show that patients with RA spend private time and costs on travelling when they seek treatment. These findings are particularly important when analyzing social costs associated with RA.

  17. Contact frequency, travel time, and travel costs for patients with rheumatoid arthritis.

    Science.gov (United States)

    Sørensen, Jan; Linde, Louise; Hetland, Merete Lund

    2014-01-01

    Objectives. To investigate travel time, and travel cost related to contacts with health care providers for patients with rheumatoid arthritis (RA) during a three-month period. Methods. Patient-reported travel time and travel cost were obtained from 2847 patients with RA. Eleven outpatient clinics across Denmark recruited patients to the study. Data collected included frequency, travel time and travel costs for contacts at rheumatology outpatient clinics, other outpatient clinics, general practitioners, privately practicing medical specialists, inpatient hospitals and accident and emergency departments. Results. Over a 3-month period, patients with RA had on average 4.4 (sd 5.7) contacts with health care providers, of which 2.8 (sd 4.0) contacts were with rheumatology outpatient clinics. Private car and public travel were the most frequent modes of travel. The average patient spent 63 minutes and 13 € on travelling per contact, corresponding to a total of 4.6 hours and 56 € during the 3-month period. There was great variation in patient travel time and costs, but no statistically significant associations were found with clinical and sociodemographic characteristics. Conclusion. The results show that patients with RA spend private time and costs on travelling when they seek treatment. These findings are particularly important when analyzing social costs associated with RA.

  18. Double Girder Bridge Crane with Double Cycling: Scheduling Strategy and Performance Evaluation

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2014-01-01

    Full Text Available This paper introduces a novel quay crane design, double girder bridge crane (DGBC. DGBC is capable of handling containers of two adjacent bays simultaneously, avoiding crane collisions, saving travelling and reposition cost, and eventually improving terminal efficiency. This problem is formulated as a resource-constrained project scheduling with objective to minimize the maximum completion time. A two-stage heuristic algorithm is proposed in which an operating sequences on each bay is obtained by double cycling, and the integrated timetable for both bays is constructed by solving resource conflicts using the proposed minimum cost strategy. We examine effectiveness and performance of applying DGBC with double cycling. A case study is presented to illustrate how DGBC works with the two-stage method. Three extreme cases with respective conflict types are investigated to develop the performance bounds of DGBC with double cycling. The results show that DGBC can significantly improve terminal productivity, and outperforms single girder crane in both makespan and the lift operation percentage. The highest DGBC efficiency does not require maximum double cycles in two bay schedules; rather the integrated timetable for two bays is the main contribution to the DGBC performance as it yields better cooperation between two spreaders and the driver.

  19. Naive newcomer or shrewd salesman

    International Nuclear Information System (INIS)

    Bergesen, H.O.; Sydnes, A.K.

    1990-01-01

    The book discusses the energy policy and conflict relations in the Norwegian petroleum sector. The purpose of the book is to describe how Norwegian society and its decisionmakers have responded to the conflicting interests, to analyze how domestic economic and political life and external relations have changed in this process, and to evaluate how this has affected Norway's position in the oil and gas markets together with the international relations surrounding them. 92 refs., 21 figs., 4 tabs

  20. German travelers' preferences for travel vaccines assessed by a discrete choice experiment.

    Science.gov (United States)

    Poulos, Christine; Curran, Desmond; Anastassopoulou, Anastassia; De Moerlooze, Laurence

    2018-02-08

    Many travelers to regions with endemic infectious diseases do not follow health authorities' recommendations regarding vaccination against vaccine-preventable infectious diseases, before traveling. The determinants of individual travelers' decisions to vaccinate before traveling are largely unknown. This study aimed to provide this information using a discrete choice experiment (DCE) administered to four types of German travelers: (1) business travelers; (2) travelers visiting friends and relatives (VFR); (3) leisure travelers; and (4) backpackers. A DCE survey was developed, pretested and administered online. It included a series of choice questions in which respondents chose between two hypothetical vaccines, each characterized by four disease attributes with varying levels describing the of risk, health impact, curability and transmissibility of the disease they would prevent (described with four disease attributes with varying levels of risk, health impact, curability and transmissibility), and varying levels of four vaccine attributes (duration of protection, number of doses required, time required for vaccination, and vaccine cost). A random-parameters logit model was used to estimate the importance weights each traveler type placed on the various attribute levels. These weights were used to calculate mean monetary equivalents (MMEs) of changes in each attribute (holding all others constant) and of hypothetical disease-vaccine combinations. All traveler types' choices indicated that they attached the greatest importance to the risk and health impact of disease and to the vaccine cost whereas the other disease and vaccine attributes were less important for their decisions about travel vaccines. An option of not choosing any of the vaccine-pairs presented was rarely selected indicating that travelers' generally prefer to be vaccinated rather than not. The MMEs of changes in vaccine attributes indicated a very high variability between the individual travelers

  1. Travel and migration associated infectious diseases morbidity in Europe, 2008

    NARCIS (Netherlands)

    Field, V.; Gautret, P.; Schlagenhauf, P.; Burchard, G.D.; Caumes, E.; Jensenius, M.; Castelli, F.; Gkrania-Klotsas, E.; Weld, L.; Lopez-Velez, R.; de Vries, P.; von Sonnenburg, F.; Loutan, L.; Parola, P.

    2010-01-01

    Background: Europeans represent the majority of international travellers and clinicians encountering returned patients have an essential role in recognizing, and communicating travel-associated public health risks. Methods: To investigate the morbidity of travel associated infectious diseases in

  2. Dynamic travel information personalized and delivered to your cell phone.

    Science.gov (United States)

    2011-01-01

    The policy of FDOT is to use the Florida Advance Traveler Information System as the primary method to disseminate timely and important travel information to the public so that the public can make informed decisions regarding their travel plans....

  3. Observing Double Stars

    Science.gov (United States)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  4. Formation of double layers

    International Nuclear Information System (INIS)

    Leung, P.; Wong, A.Y.; Quon, B.H.

    1981-01-01

    Experiments on both stationary and propagating double layers and a related analytical model are described. Stationary double layers were produced in a multiple plasma device, in which an electron drift current was present. An investigation of the plasma parameters for the stable double layer condition is described. The particle distribution in the stable double layer establishes a potential profile, which creates electron and ion beams that excite plasma instabilities. The measured characteristics of the instabilities are consistent with the existence of the double layer. Propagating double layers are formed when the initial electron drift current is large. Ths slopes of the transition region increase as they propagate. A physical model for the formation of a double layer in the experimental device is described. This model explains the formation of the low potential region on the basis of the space charge. This space charge is created by the electron drift current. The model also accounts for the role of ions in double layer formation and explains the formation of moving double layers. (Auth.)

  5. [Business travel and staying abroad].

    Science.gov (United States)

    Holdener, F; Stahel, E

    1989-11-01

    The growing internationalization of business and the economy is leading more and more working people to spend short or even long stays abroad. With fast journeys across several time zones, travellers are mainly confronted with problems of time difference adjustment, commonly known as "jet lag". For longer stays, especially when the family comes along too, a number of additional difficulties may arise which are not normally faced by tourists. People's physical ability to tolerate a long stay in the tropics is rarely questioned nowadays, except in cases of serious physical illness. However, the effects of such stays on an individual's psychological condition are receiving increasing attention. Inoculations and advice are largely determined by the epidemiology of infectious diseases and the medical infrastructure of the country of destination. Death caused by illness can almost always be avoided through the appropriate prophylaxis and/or therapy. Unfortunately, the same does not apply to accidents. The local medical infrastructure in the larger cities of the developing countries and the range of flights available for sick and injured people are continually improving with a few exceptions.

  6. Functional features of travel magazines: retrospective view

    Directory of Open Access Journals (Sweden)

    Gromova Lyudmila Petrovna

    2015-09-01

    Full Text Available The article considers the features of the functional purpose of travel magazines (travelogue, their genesis, evolution, traits, depending on the socio-political context and, accordingly, requests from the readership. The progenitor of the travel magazines in Russia was journey literature that took root in the genre of travel notes. The forerunner of today’s travelogues can be considered «Nikita Akinfievich Demidov’s travel magazine» (1786, presenting daily travel notes, mostly laconic, sometimes deployed to fascinating travel notes Magazines at different times performed cultural and educational, didactic, aesthetic and ideological functions, immersing the reader in the living conditions of the countries and continents, showing the diversity of the world. Today, traveling is seen as a multifaceted activity that is due to the result of freedom of movement, numerous hiking trails, access to information in the network space takes new character. Accordingly, the media market is a process of qualitative and quantitative changes. There is a growing number of distribution channels, many of which are convergent evolution. The transformation of the old forms is determined by market demand. These processes are inevitably reflected in the dominance of certain functions of the travelogue. However, their essential purpose remains the same: to inform, educate and entertain.

  7. Globalization of leptospirosis through travel and migration.

    Science.gov (United States)

    Bandara, Medhani; Ananda, Mahesha; Wickramage, Kolitha; Berger, Elisabeth; Agampodi, Suneth

    2014-08-12

    Leptospirosis remains the most widespread zoonotic disease in the world, commonly found in tropical or temperate climates. While previous studies have offered insight into intra-national and intra-regional transmission, few have analyzed transmission across international borders. Our review aimed at examining the impact of human travel and migration on the re-emergence of Leptospirosis. Results suggest that alongside regional environmental and occupational exposure, international travel now constitute a major independent risk factor for disease acquisition. Contribution of travel associated leptospirosis to total caseload is as high as 41.7% in some countries. In countries where longitudinal data is available, a clear increase of proportion of travel-associated leptospirosis over the time is noted. Reporting patterns is clearly showing a gross underestimation of this disease due to lack of diagnostic facilities. The rise in global travel and eco-tourism has led to dramatic changes in the epidemiology of Leptospirosis. We explore the obstacles to prevention, screening and diagnosis of Leptopirosis in health systems of endemic countries and of the returning migrant or traveler. We highlight the need for developing guidelines and preventive strategies of Leptospirosis related to travel and migration, including enhancing awareness of the disease among health professionals in high-income countries.

  8. Traveling with children: beyond car seat safety.

    Science.gov (United States)

    Polli, Janaina Borges; Polli, Ismael

    2015-01-01

    To spread knowledge and instigate the health professional to give advice on childcare during travels and on child transport safety. Literature review through the LILACS and MEDLINE(®) databases, using the terms: travel, safety, protective equipment, child, preventive medicine, retrieving articles published in the last 21 years. The authors analyzed 93 articles, of which 66 met the inclusion criteria after summaries were read. For drafting this article, the following sub-themes were proposed: getting ready to travel with children; knowing some of the transfer risks (air, land and water transportation) and exploring the destination with children (sun exposure, accommodations, altitude, food, traveler's diarrhea, insect bites) and return from the trip with children. Over the years, there has been an increase in the number of children who travel around the world. However, this population is still subject to health problems while traveling and may be even more susceptible than the adult age group. These problems arise from a variety of factors, including exposure to infectious organisms, the use of certain types of transportation, and participation in some activities, such as hiking at high altitudes, among others. However, when traveling with children, these risk factors can be overlooked; a trip that is considered safe for an adult might not be a good choice for this age group. The pediatric consultation should be a good opportunity to optimize preventive guidelines at the pre-trip planning. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  9. Multimodal Network Equilibrium with Stochastic Travel Times

    Directory of Open Access Journals (Sweden)

    M. Meng

    2014-01-01

    Full Text Available The private car, unlike public traffic modes (e.g., subway, trolley running along dedicated track-ways, is invariably subject to various uncertainties resulting in travel time variation. A multimodal network equilibrium model is formulated that explicitly considers stochastic link capacity variability in the road network. The travel time of combined-mode trips is accumulated based on the concept of the mean excess travel time (METT which is a summation of estimated buffer time and tardy time. The problem is characterized by an equivalent VI (variational inequality formulation where the mode choice is expressed in a hierarchical logit structure. Specifically, the supernetwork theory and expansion technique are used herein to represent the multimodal transportation network, which completely represents the combined-mode trips as constituting multiple modes within a trip. The method of successive weighted average is adopted for problem solutions. The model and solution method are further applied to study the trip distribution and METT variations caused by the different levels of the road conditions. Results of numerical examples show that travelers prefer to choose the combined travel mode as road capacity decreases. Travelers with different attitudes towards risk are shown to exhibit significant differences when making travel choice decisions.

  10. A microlevel analysis of residential context and travel time

    OpenAIRE

    Tim Schwanen; Martin Dijst; Frans M Dieleman

    2002-01-01

    The literature on the association between residential context and travel concentrates on distance traveled and modal choice, as these variables are the most important from an environmental perspective. Travel time has received less attention -- an unfortunate oversight in our view, as people's travel decisions are determined by time rather than by distance. By using data from the 1998 Netherlands National Travel Survey, we have considered travel time associated with trip purpose and transport...

  11. Mapping Generic Territory: The Pedagogy and Practice of Travel Writing

    OpenAIRE

    Roberts, Zoe

    2016-01-01

    This thesis engages with travel writing at two levels: pedagogically and practically. It discusses at length, the unique configuration of travel writing’s literary currencies and conventions. Primary linguistic data were collected from travel texts collated within a portfolio of the researcher’s own negotiated and sustained practice as a travel writer. Within this portfolio the researcher engaged with a variety of travel text types, including a travel blog, prose and a poem. A close reading ...

  12. Nonlinear interactions of counter-travelling waves

    International Nuclear Information System (INIS)

    Matsuuchi, Kazuo

    1980-01-01

    Nonlinear interactions between two waves travelling in opposite directions are investigated. When a nonlinear Klein-Gordon equation is adopted as a model equation, it is shown that such a wave system is governed by a simple set of equations for their complex amplitudes. Steady progressive waves governed by this set are investigated for various cases classified according to the signs of the coefficients. It is then found that one wave travelling in one direction appears from a certain point and the other travelling in the opposite direction has a constant amplitude from that point. This phenomenon may be regarded as a sort of reflection in spite of no rigid boundary. (author)

  13. HIV in elderly women after travelling abroad

    DEFF Research Database (Denmark)

    Jespersen, Sanne; Thorsteinsson, Kristina; David, Kim Peter

    2016-01-01

    We report two cases of HIV infection among female travellers of older age. A Danish woman in her eighties was diagnosed with acute HIV infection after travelling to West Africa. A sexual history was not recorded before her third hospital visit. A West African woman in her seventies who had been...... living in Denmark for 40 years was diagnosed with advanced HIV after having been to West Africa for family visits. We want to emphasize that women of older age also have sex that may put them at risk of HIV, that febrile returning travellers should be tested for HIV, and that presence of HIV indicator...

  14. Pre-travel advice: an overview.

    Science.gov (United States)

    Sanford, Christopher

    2002-12-01

    The message of the pre-travel provider is necessarily paradoxic. First the provider lists a score of causes of illness and premature demise, and then states, "But it sounds like a great trip and I think you'll have fun." Pre-travel providers need to walk a fine line: they must encourage patients to be cautious but not paranoid, optimistic but realistic. This discussion is complicated further by the fact that risk reduction is not the only consideration; if it were, practitioners would advise patients to remain in the developed world and foray from their homes only to visit health clubs and the fruit-and-vegetable section of grocery stores. A tacit assumption in travel medicine is that some degree of acceptance of heightened risk is tolerated for the benefit of improved quality of life offered by travel abroad. The amount of risk that is reasonable to accept for a given benefit in quality of life yielded by travel cannot be quantified, however. Providers must render judgments on what is "reasonable" and what is not, and this complex decision is based on equal parts medical knowledge and intuition. At one extreme, mountaineers in Nepal have been found to have a 2.4% mortality rate per expedition [83,84]. The travel provider might make the reasonable decision to counsel these travelers to avoid that activity. These travelers most likely will ignore that advice, at which point the provider must endeavor to reduce risk to the extent possible. Other situations in which the provider should advise a change in itinerary or activities include counseling parents who plan to take an infant to high altitude or a pregnant woman who plans to scuba dive. If travelers remain cloistered in their hotel rooms, eating all meals from room service and watching CNN, then it could be suggested that they are overly risk-adverse and might consider foraying out of the hotel, despite the potential associated increased risks to health. Conversely, if travelers find themselves on motorcycles

  15. Principles of valuing business travel time savings

    OpenAIRE

    Fowkes, A.S.

    2001-01-01

    OVERVIEW\\ud \\ud There are two approaches to valuing travel time savings to business people. The first is that which has formed the basis of UK policy for about 30 years, and which is set out in Section 2. This takes the value of travel time savings on employer’s business as equal to the gross wage rate plus an allowance for other costs that the employer saves. These might include such things as desk space, computer, tools, uniform, protective clothing, travel expenses. These were investigated...

  16. Kapitza–Dirac effect with traveling waves

    International Nuclear Information System (INIS)

    Hayrapetyan, Armen G; Götte, Jörg B; Grigoryan, Karen K; Petrosyan, Rubik G

    2015-01-01

    We report on the possibility of diffracting electrons from light waves traveling inside a dielectric medium. We show that, in the frame of reference which moves with the group velocity of light, the traveling wave acts as a stationary diffraction grating from which electrons can diffract, similar to the conventional Kapitza–Dirac effect. To characterize the Kapitza–Dirac effect with traveling light waves, we make use of the Hamiltonian Analogy between electron optics and quantum mechanics and apply the Helmholtz–Kirchhoff theory of diffraction. (fast track communication)

  17. Travelling wave solutions in delayed cooperative systems

    International Nuclear Information System (INIS)

    Li, Bingtuan; Zhang, Liang

    2011-01-01

    We establish the existence of travelling wave solutions for delayed cooperative recursions that are allowed to have more than two equilibria. We define an important extended real number that is used to determine the speeds of travelling wave solutions. The results can be applied to a large class of delayed cooperative reaction–diffusion models. We show that for a delayed Lotka–Volterra reaction–diffusion competition model, there exists a finite positive number c * + that can be characterized as the slowest speed of travelling wave solutions connecting two mono-culture equilibria or connecting a mono-culture with the coexistence equilibrium

  18. Ocean acoustic tomography - Travel time biases

    Science.gov (United States)

    Spiesberger, J. L.

    1985-01-01

    The travel times of acoustic rays traced through a climatological sound-speed profile are compared with travel times computed through the same profile containing an eddy field. The accuracy of linearizing the relations between the travel time difference and the sound-speed deviation at long ranges is assessed using calculations made for two different eddy fields measured in the eastern Atlantic. Significant nonlinearities are found in some cases, and the relationships of the values of these nonlinearities to the range between source and receiver, to the anomaly size associated with the eddies, and to the positions of the eddies are studied. An analytical model of the nonlinearities is discussed.

  19. Representation of Central Asia and Traveling Self in Vambery’s Travels in Central Asia

    Directory of Open Access Journals (Sweden)

    Ahmad Gholi

    2016-03-01

    Full Text Available In the course of the nineteenth century Arminius Vambery, an anglophile travel writer, in the guise of a mendicant dervish with a group of Tartar pilgrims departs to secluded and sealed Central Asia. After six months travel in the Khanates of Central Asia, he undertakes a journey to England where he offers his observations to the Royal Geographical Society and publishes his travelogue, Travel in Central Asia. Despite its literary merits and connection with British imperialism, the travelogue has not been scrutinized separately by the scholars of travel writing. To fill the gap, this article by drawing on the theories of post-structuralism: Orientalism and Postcolonialism, endeavors to unveil the political agenda behind the travel writer’s representation of his travelees, destination, and his own traveling self. Additionally, it argues that the travel writer in dialogue with other Western travel writers to deterritorialize his traversed region or justify the prospective presence of Britain in Central Asia, represents his journey destination as the locus of barbarity, a region under the grip of despotic rulers, as well as an area with frozen time, while to exhibit his Eurocentrism, he portrays his traveling subject as the a suffering hero and a benign traveler.

  20. Health risks, travel preparation, and illness among public health professionals during international travel.

    Science.gov (United States)

    Balaban, Victor; Warnock, Eli; Ramana Dhara, V; Jean-Louis, Lee Ann; Sotir, Mark J; Kozarsky, Phyllis

    2014-01-01

    Few data currently exist on health risks faced by public health professionals (PHP) during international travel. We conducted pre- and post-travel health surveys to assess knowledge, attitudes, and practices (KAP), and illnesses among PHP international travelers. Anonymous surveys were completed by PHP from a large American public health agency who sought a pre-travel medical consult from September 1, 2009, to September 30, 2010. Surveys were completed by 122 participants; travelers went to 163 countries. Of the 122 respondents, 97 (80%) reported at least one planned health risk activity (visiting rural areas, handling animals, contact with blood or body fluids, visiting malarious areas), and 50 (41%) reported exposure to unanticipated health risks. Of the 62 travelers who visited malarious areas, 14 (23%) reported inconsistent or no use of malaria prophylaxis. Illness during travel was reported by 33 (27%) respondents. Most of the PHP travelers in our study reported at least one planned health risk activity, and almost half reported exposure to unanticipated health risks, and one-quarter of travelers to malarious areas reported inconsistent or no use of malaria chemoprophylaxis. Our findings highlight that communication and education outreach for PHP to prevent travel-associated illnesses can be improved. Published by Elsevier Ltd.