WorldWideScience

Sample records for average travel speed

  1. Near surface spatially averaged air temperature and wind speed determined by acoustic travel time tomography

    Directory of Open Access Journals (Sweden)

    Armin Raabe

    2001-03-01

    Full Text Available Acoustic travel time tomography is presented as a possibility for remote monitoring of near surface airtemperature and wind fields. This technique provides line-averaged effective sound speeds changing with temporally and spatially variable air temperature and wind vector. The effective sound speed is derived from the travel times of sound signals which propagate at defined paths between different acoustic sources and receivers. Starting with the travel time data a tomographic algorithm (Simultaneous Iterative Reconstruction Technique, SIRT is used to calculate area-averaged air temperature and wind speed. The accuracy of the experimental method and the tomographic inversion algorithm is exemplarily demonstrated for one day without remarkable differences in the horizontal temperature field, determined by independent in situ measurements at different points within the measuring field. The differences between the conventionally determined air temperature (point measurement and the air temperature determined by tomography (area-averaged measurement representative for the area of the measuring field 200m x 260m were below 0.5 K for an average of 10 minutes. The differences obtained between the wind speed measured at a meteorological mast and calculated from acoustic measurements are not higher than 0.5 ms-1 for the same averaging time. The tomographically determined area-averaged distribution of air temperature (resolution 50 m x 50 m can be used to estimate the horizontal gradient of air temperature as a pre-condition to detect horizontal turbulent fluxes of sensible heat.

  2. Multi-Scale Visualization Analysis of Bus Flow Average Travel Speed in Qingdao

    Science.gov (United States)

    Yong, HAN; Man, GAO; Xiao-Lei, ZHANG; Jie, LI; Ge, CHEN

    2016-11-01

    Public transportation is a kind of complex spatiotemporal behaviour. The traffic congestion and environmental pollution caused by the increase in private cars is becoming more and more serious in our city. Spatiotemporal data visualization is an effective tool for studying traffic, transforming non-visual data into recognizable images, which can reveal where/when congestion is formed, developed and disappeared in space and time simultaneously. This paper develops a multi-scale visualization of average travel speed derived from floating bus data, to enable congestion on urban bus networks to be shown and analyzed. The techniques of R language, Echarts, WebGL are used to draw statistical pictures and 3D wall map, which show the congestion in Qingdao from the view of space and time. The results are as follows:(1) There is a more severely delay in Shibei and Shinan areas than Licun and Laoshan areas; (2) The high congestion usually occurs on Hong Kong Middle Road, Shandong Road, Nanjing Road, Liaoyang West Road and Taiping Road;(3) There is a similar law from Monday to Sunday that the congestion is severer in the morning and evening rush hours than other hours; (4) On Monday morning the severity of congestion is higher than on Friday morning, and on Friday evening the severity is higher than on Monday evening. The research results will help to improve the public transportation of Qingdao.

  3. A constant travel time budget? In search for explanations for an increase in average travel time

    NARCIS (Netherlands)

    Rietveld, P.; Wee, van B.

    2002-01-01

    Recent research suggests that during the past decades the average travel time of the Dutch population has probably increased. However, different datasources show different levels of increase. Possible causes of the increase in average travel time are presented here. Increased incomes have probablyre

  4. Road and Street Centerlines, Average Freeway/Arterial/Low Speed Arterial Travel Speeds - Spring and Fall 2010 Data collected during PM Peak period (4:30 - 6:30pm) and AM Peak Period (7 - 9am) on selected roadways - GPS travel speeds at 1,000 ft interval, Published in 2010, 1:2400 (1in=200ft) scale, Baltimore Metropolitan Council.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — , published at 1:2400 (1in=200ft) scale, was produced all or in part from Field Survey/GPS information as of 2010. It is described as 'Average Freeway/Arterial/Low...

  5. Safety Impact of Average Speed Control in the UK

    DEFF Research Database (Denmark)

    Lahrmann, Harry Spaabæk; Brassøe, Bo; Johansen, Jonas Wibert

    2016-01-01

    in the UK. The study demonstrates that the introduction of average speed control results in statistically significant and substantial reductions both in speed and in number of accidents. The evaluation indicates that average speed control has a higher safety effect than point-based automatic speed control....

  6. Floating Car Data Based Nonparametric Regression Model for Short-Term Travel Speed Prediction

    Institute of Scientific and Technical Information of China (English)

    WENG Jian-cheng; HU Zhong-wei; YU Quan; REN Fu-tian

    2007-01-01

    A K-nearest neighbor (K-NN) based nonparametric regression model was proposed to predict travel speed for Beijing expressway. By using the historical traffic data collected from the detectors in Beijing expressways, a specically designed database was developed via the processes including data filtering, wavelet analysis and clustering. The relativity based weighted Euclidean distance was used as the distance metric to identify the K groups of nearest data series. Then, a K-NN nonparametric regression model was built to predict the average travel speeds up to 6 min into the future. Several randomly selected travel speed data series,collected from the floating car data (FCD) system, were used to validate the model. The results indicate that using the FCD, the model can predict average travel speeds with an accuracy of above 90%, and hence is feasible and effective.

  7. Speed ot travelling waves in reaction-diffusion equations

    Energy Technology Data Exchange (ETDEWEB)

    Benguria, R.D.; Depassier, M.C. [Facultad de Fisica, Pontificia Universidad Catolica de Chile, Avda. Vicuna Mackenna 4860, Santiago (Chile); Mendez, V. [Facultat de Ciencies de la Salut, Universidad Internacional de Catalunya, Gomera s/n 08190 Sant Cugat del Valles, Barcelona (Spain)

    2002-07-01

    Reaction diffusion equations arise in several problems of population dynamics, flame propagation and others. In one dimensional cases the systems may evolve into travelling fronts. Here we concentrate on a reaction diffusion equation which arises as a simple model for chemotaxis and present results for the speed of the travelling fronts. (Author)

  8. Impact of connected vehicle guidance information on network-wide average travel time

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2016-12-01

    Full Text Available With the emergence of connected vehicle technologies, the potential positive impact of connected vehicle guidance on mobility has become a research hotspot by data exchange among vehicles, infrastructure, and mobile devices. This study is focused on micro-modeling and quantitatively evaluating the impact of connected vehicle guidance on network-wide travel time by introducing various affecting factors. To evaluate the benefits of connected vehicle guidance, a simulation architecture based on one engine is proposed representing the connected vehicle–enabled virtual world, and connected vehicle route guidance scenario is established through the development of communication agent and intelligent transportation systems agents using connected vehicle application programming interface considering the communication properties, such as path loss and transmission power. The impact of connected vehicle guidance on network-wide travel time is analyzed by comparing with non-connected vehicle guidance in response to different market penetration rate, following rate, and congestion level. The simulation results explore that average network-wide travel time in connected vehicle guidance shows a significant reduction versus that in non–connected vehicle guidance. Average network-wide travel time in connected vehicle guidance have an increase of 42.23% comparing to that in non-connected vehicle guidance, and average travel time variability (represented by the coefficient of variance increases as the travel time increases. Other vital findings include that higher penetration rate and following rate generate bigger savings of average network-wide travel time. The savings of average network-wide travel time increase from 17% to 38% according to different congestion levels, and savings of average travel time in more serious congestion have a more obvious improvement for the same penetration rate or following rate.

  9. Speed dependence of averaged EMG profiles in walking

    NARCIS (Netherlands)

    Hof, AL; Elzinga, H; Grimmius, W; Halbertsma, JPK

    2002-01-01

    Electromyogram (EMG) profiles strongly depend on walking speed and, in pathological gait, patients do not usually walk at normal speeds. EMG data was collected from 14 muscles in two groups of healthy young subjects who walked at five different speeds ranging from 0.75 to 1.75 ms(-1). We found that

  10. Integrating stochastic time-dependent travel speed in solution methods for the dynamic dial-a-ride problem.

    Science.gov (United States)

    Schilde, M; Doerner, K F; Hartl, R F

    2014-10-01

    In urban areas, logistic transportation operations often run into problems because travel speeds change, depending on the current traffic situation. If not accounted for, time-dependent and stochastic travel speeds frequently lead to missed time windows and thus poorer service. Especially in the case of passenger transportation, it often leads to excessive passenger ride times as well. Therefore, time-dependent and stochastic influences on travel speeds are relevant for finding feasible and reliable solutions. This study considers the effect of exploiting statistical information available about historical accidents, using stochastic solution approaches for the dynamic dial-a-ride problem (dynamic DARP). The authors propose two pairs of metaheuristic solution approaches, each consisting of a deterministic method (average time-dependent travel speeds for planning) and its corresponding stochastic version (exploiting stochastic information while planning). The results, using test instances with up to 762 requests based on a real-world road network, show that in certain conditions, exploiting stochastic information about travel speeds leads to significant improvements over deterministic approaches.

  11. Spreading speeds and traveling waves for non-cooperative reaction-diffusion systems

    CERN Document Server

    Wang, Haiyan

    2010-01-01

    Much has been studied on the spreading speed and traveling wave solutions for cooperative reaction-diffusion systems. In this paper, we shall establish the spreading speed for a large class of non-cooperative reaction-diffusion systems and characterize the spreading speed as the slowest speed of a family of non-constant traveling wave solutions. As an application, our results are applied to a partially cooperative system describing interactions between ungulates and grass.

  12. Averaged EMG profiles in jogging and running at different speeds

    NARCIS (Netherlands)

    Gazendam, Marnix G. J.; Hof, At L.

    2007-01-01

    EMGs were collected from 14 muscles with surface electrodes in 10 subjects walking 1.25-2.25 m s(-1) and running 1.25-4.5 m s(-1). The EMGs were rectified, interpolated in 100% of the stride, and averaged over all subjects to give an average profile. In running, these profiles could be decomposed in

  13. Planning the most suitable travel speed for high frequency railway lines

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.

    2005-01-01

    This paper presents a new method to calculate the most suitable travel speed for high frequency railway lines to achieve as much capacity as possible for congested railway lines. The method calculates the most suitable travel speed based on the braking distance and information about...... of the railway line, and the more buffer time on the railway line, the better punctuality and the better possibilities to run more trains. Based on the described method a case example from the suburban railway lines of Copenhagen will be shown. The case example shows that a reduction of the maximum travel speed...

  14. The volitional travel speed varies with reproductive state in mature female brown trout Salmo trutta

    DEFF Research Database (Denmark)

    Svendsen, Jon Christian; Aarestrup, Kim; Dolby, Jes;

    2009-01-01

    This study tested the effect of reproduction on the volitional travel speed of mature female brown trout Salmo trutta L. The downstream travel speed in the pre-spawning state was 0·25 m s−1 (95% CI : 0·19, 0·34) while it increased significantly to 0·65 m s−1 (95% CI: 0·49, 0·87) in the post...

  15. Desing And Implementation Of A Digitally Controlled Compact Speed Driver For Travelling Wave Ultrasonic Motor

    OpenAIRE

    Altan Gencer

    2013-01-01

    In this paper, a compact size digitally controlled speed driver for travelling wave ultrasonic motor was designed and implemented. Although the driver system is light in weight, simple, small in size, it is possible to enter speed and direction digitally as well as tracking the real motor speed, voltage and current on an LCD. The implemented system was tested in a laboratory for different speed and load cases and obtained results are presented.

  16. Desing And Implementation Of A Digitally Controlled Compact Speed Driver For Travelling Wave Ultrasonic Motor

    Directory of Open Access Journals (Sweden)

    Altan Gencer

    2013-05-01

    Full Text Available In this paper, a compact size digitally controlled speed driver for travelling wave ultrasonic motor was designed and implemented. Although the driver system is light in weight, simple, small in size, it is possible to enter speed and direction digitally as well as tracking the real motor speed, voltage and current on an LCD. The implemented system was tested in a laboratory for different speed and load cases and obtained results are presented.

  17. TRAVELING WAVE SPEED AND SOLUTION IN REACTION-DIFFUSION EQUATION IN ONE DIMENSION

    Institute of Scientific and Technical Information of China (English)

    周天寿; 张锁春

    2001-01-01

    By Painlevé analysis, traveling wave speed and solution of reaction-diffusion equations for the concentration of one species in one spatial dimension are in detail investigated. When the exponent of the creation term is larger than the one of the annihilation term, two typical cases are studied, one with the exact traveling wave solutions, yielding the values of speeds, the other with the series expansion solution, also yielding the value of speed. Conversely, when the exponent of creation term is smaller than the one of the annihilation term, two typical cases are also studied, but only for one of them, there is a series development solution, yielding the value of speed, and for the other, traveling wave solution cannot exist. Besides, the formula of calculating speeds and solutions of planar wave within the thin boundary layer are given for a class of typical excitable media.

  18. Communication: Green-Kubo approach to the average swim speed in active Brownian systems

    Science.gov (United States)

    Sharma, A.; Brader, J. M.

    2016-10-01

    We develop an exact Green-Kubo formula relating nonequilibrium averages in systems of interacting active Brownian particles to equilibrium time-correlation functions. The method is applied to calculate the density-dependent average swim speed, which is a key quantity entering coarse grained theories of active matter. The average swim speed is determined by integrating the equilibrium autocorrelation function of the interaction force acting on a tagged particle. Analytical results are validated using Brownian dynamics simulations.

  19. Actuator disk model of wind farms based on the rotor average wind speed

    DEFF Research Database (Denmark)

    Han, Xing Xing; Xu, Chang; Liu, De You;

    2016-01-01

    Due to difficulty of estimating the reference wind speed for wake modeling in wind farm, this paper proposes a new method to calculate the momentum source based on the rotor average wind speed. The proposed model applies volume correction factor to reduce the influence of the mesh recognition...

  20. General Ripple Mobility Model: A Novel Mobility Model of Uniform Spatial Distribution and Diverse Average Speed

    Science.gov (United States)

    Chen, Chun-Hung; Wu, Ho-Ting; Ke, Kai-Wei

    Simulations are often deployed to evaluate proposed mechanisms or algorithms in Mobile Ad Hoc Networks (MANET). In MANET, the impacts of some simulation parameters are noticeable, such as transmission range, data rate etc. However, the effect of mobility model is not clear until recently. Random Waypoint (RWP) is one of the most applied nodal mobility models in many simulations due to its clear procedures and easy employments. However, it exhibits the two major problems: decaying average speed and border effect. Both problems will overestimate the performance of the employed protocols and applications. Although many recently proposed mobility models are able to reduce or eliminate the above-mentioned problems, the concept of Diverse Average Speed (DAS) has not been introduced. DAS aims to provide different average speeds within the same speed range. In most mobility models, the average speed is decided when the minimum and maximum speeds are set. In this paper, we propose a novel mobility model, named General Ripple Mobility Model (GRMM). GRMM targets to provide a uniform nodal spatial distribution and DAS without decaying average speed. The simulations and analytic results have demonstrated the merits of the outstanding properties of the GRMM model.

  1. THE SPEED OF GRAVITY AND HYPER-FAST TRAVEL IN GENERAL RELATIVITY

    Directory of Open Access Journals (Sweden)

    Trunev A. P.

    2014-06-01

    Full Text Available The equation of parabolic type, describing the evolution of the gravitational field on the scale of the solar system, galaxy and cluster galaxies is derived from the Einstein equation. Space-time metric compatible with the post-Newtonian approximation and the metric of the expanding universe, and allowing hyper-fast travel in Einstein's theory of gravitation is considered. It is shown that the speed of hyper-fast travel depends on the implementation, including the parameters of ground state of the expanding universe. A criterion for the maximum speed of motion of material bodies has been proposed

  2. Time series models to simulate and forecast hourly averaged wind speeds in Quetta, Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Lalarukh Kamal [Balochistan University, Quetta (Pakistan). Dept. of Mathematics; Yasmin Zahra Jafri [Balochistan University, Quetta (Pakistan). Dept. of Statistics

    1997-07-01

    Stochastic simulation and forecast models of hourly average wind speeds are presented. Time series models take into account several basic features of wind speed data including autocorrelation, non-Gaussian distribution and diurnal nonstationarity. The positive correlation between consecutive wind speed observations is taken into account by fitting an ARMA (p,q) process to wind speed data transformed to make their distribution approximately Gaussian and standardized to remove scattering of transformed data. Diurnal variations have been taken into account to observe forecasts and its dependence on lead times. We find the ARMA (p,q) model suitable for prediction intervals and probability forecasts. (author)

  3. A novel car following model considering average speed of preceding vehicles group

    Science.gov (United States)

    Sun, Dihua; Kang, Yirong; Yang, Shuhong

    2015-10-01

    In this paper, a new car following model is presented by considering the average speed effect of preceding vehicles group in cyber-physical systems (CPS) environment. The effect of this new consideration upon the stability of traffic flow is examined through linear stability analysis. A modified Korteweg-de Vries (mKdV) equation was derived via nonlinear analysis to describe the propagating behavior of traffic density wave near the critical point. Good agreement between the simulation and the analytical results shows that average speed of preceding vehicles group leads to the stabilization of traffic systems, and thus can efficiently suppress the emergence of traffic jamming.

  4. Validity of a Wearable Accelerometer Device to Measure Average Acceleration Values During High-Speed Running.

    Science.gov (United States)

    Alexander, Jeremy P; Hopkinson, Trent L; Wundersitz, Daniel W T; Serpell, Benjamin G; Mara, Jocelyn K; Ball, Nick B

    2016-11-01

    Alexander, JP, Hopkinson, TL, Wundersitz, DWT, Serpell, BG, Mara, JK, and Ball, NB. Validity of a wearable accelerometer device to measure average acceleration values during high-speed running. J Strength Cond Res 30(11): 3007-3013, 2016-The aim of this study was to determine the validity of an accelerometer to measure average acceleration values during high-speed running. Thirteen subjects performed three sprint efforts over a 40-m distance (n = 39). Acceleration was measured using a 100-Hz triaxial accelerometer integrated within a wearable tracking device (SPI-HPU; GPSports). To provide a concurrent measure of acceleration, timing gates were positioned at 10-m intervals (0-40 m). Accelerometer data collected during 0-10 m and 10-20 m provided a measure of average acceleration values. Accelerometer data was recorded as the raw output and filtered by applying a 3-point moving average and a 10-point moving average. The accelerometer could not measure average acceleration values during high-speed running. The accelerometer significantly overestimated average acceleration values during both 0-10 m and 10-20 m, regardless of the data filtering technique (p < 0.001). Body mass significantly affected all accelerometer variables (p < 0.10, partial η = 0.091-0.219). Body mass and the absence of a gravity compensation formula affect the accuracy and practicality of accelerometers. Until GPSports-integrated accelerometers incorporate a gravity compensation formula, the usefulness of any accelerometer-derived algorithms is questionable.

  5. Frequency domain averaging based experimental evaluation of gear fault without tachometer for fluctuating speed conditions

    Science.gov (United States)

    Sharma, Vikas; Parey, Anand

    2017-02-01

    In the purview of fluctuating speeds, gear fault diagnosis is challenging due to dynamic behavior of forces. Various industrial applications employing gearbox which operate under fluctuating speed conditions. For diagnostics of a gearbox, various vibrations based signal processing techniques viz FFT, time synchronous averaging and time-frequency based wavelet transform, etc. are majorly employed. Most of the time, theories about data or computational complexity limits the use of these methods. In order to perform fault diagnosis of a gearbox for fluctuating speeds, frequency domain averaging (FDA) of intrinsic mode functions (IMFs) after their dynamic time warping (DTW) has been done in this paper. This will not only attenuate the effect of fluctuating speeds but will also extract the weak fault feature those masked in vibration signal. Experimentally signals were acquired from Drivetrain Diagnostic Simulator for different gear health conditions i.e., healthy pinion, pinion with tooth crack, chipped tooth and missing tooth and were analyzed for the different fluctuating profiles of speed. Kurtosis was calculated for warped IMFs before DTW and after DTW of the acquired vibration signals. Later on, the application of FDA highlights the fault frequencies present in the FFT of faulty gears. The result suggests that proposed approach is more effective towards the fault diagnosing with fluctuating speed.

  6. High-Speed Train Stop-Schedule Optimization Based on Passenger Travel Convenience

    Directory of Open Access Journals (Sweden)

    Dingjun Chen

    2016-01-01

    Full Text Available The stop-schedules for passenger trains are important to the operation planning of high-speed trains, and they decide the quality of passenger service and the transportation efficiency. This paper analyzes the specific manifestation of passenger travel convenience and proposes the concepts of interstation accessibility and degree of accessibility. In consideration of both the economic benefits of railway corporations and the travel convenience of passengers, a multitarget optimization model is established. The model aims at minimizing stop cost and maximizing passenger travel convenience. Several constraints are applied to the model establishment, including the number of stops made by individual trains, the frequency of train service received by each station, the operation section, and the 0-1 variable. A hybrid genetic algorithm is designed to solve the model. Both the model and the algorithm are validated through case study.

  7. [Predictors of Average Speed in Orienteering: The Number of Controls is Crucial].

    Science.gov (United States)

    Gasser, B A

    2016-06-01

    The aim of this study was to compare differences in average speed in the three competition forms orienteering sprint, long distance and hunt start, and to identify reasons for speed differences. In contrast to classic running disciplines, average speed increased with longer distances, which is probably due to technical requirements or the number of controls, which decreased proportionally with longer distances. These analyses emphasise the importance of map-reading in the area of controls since these parts of the races seem to bear a great deal of potential to optimize running times, thereby enabling runners to achieve their maximum performance levels. Based on these findings, the principal of focusing training on one distance due to biological constraints is less important in orienteering than it is in running disciplines. However, if runners do choose to focus on a certain speed, e. g. in the case of elite runners, analogous to 5-km runs, the training of sprints or half-marathons for the classic distance should be structured and organised. Runners prioritising sprint should therefore focus on lactate tolerance or speed work in training whereas runners prioritising classic distance should put emphasis on basic endurance and threshold training. To sum up, this study highlights the relevance of cognitive-technical skills in the control area of races. These elements should constantly be trained by orienteers, independently of physical constraints, in order for them to realise their full potential in races.

  8. An improved car-following model with two preceding cars' average speed

    Science.gov (United States)

    Yu, Shao-Wei; Shi, Zhong-Ke

    2015-01-01

    To better describe cooperative car-following behaviors under intelligent transportation circumstances and increase roadway traffic mobility, the data of three successive following cars at a signalized intersection of Jinan in China were obtained and employed to explore the linkage between two preceding cars' average speed and car-following behaviors. The results indicate that two preceding cars' average velocity has significant effects on the following car's motion. Then an improved car-following model considering two preceding cars' average velocity was proposed and calibrated based on full velocity difference model and some numerical simulations were carried out to study how two preceding cars' average speed affected the starting process and the traffic flow evolution process with an initial small disturbance, the results indicate that the improved car-following model can qualitatively describe the impacts of two preceding cars' average velocity on traffic flow and that taking two preceding cars' average velocity into account in designing the control strategy for the cooperative adaptive cruise control system can improve the stability of traffic flow, suppress the appearance of traffic jams and increase the capacity of signalized intersections.

  9. Evaluation of travelling vortex speed by means of vortex tracking and dynamic mode decomposition

    Science.gov (United States)

    Hyhlík, Tomáš

    2016-06-01

    The article deals with the analysis of unsteady periodic flow field related to synthetic jet creation. The analyses are based on the data obtained using ANSYS Fluent solver. Numerical results are validated by hot wire anemometry data measured along the jet centerline. The speed of travelling vortex ring is evaluated by using vortex tracking method and by using dynamic mode decomposition method. Vortex identification is based on residual vorticity which allows identifying regions in the flow field where fluid particles perform the rotational motion. The regime of the synthetic jet with Re = 329 and S = 19.7 is chosen. Both the vortex tracking and the dynamic mode decomposition based vortex speed evaluation indicate an increase in the vortex speed close to the orifice and then decrease with maximum reaching almost one and half of orifice centerline velocity. The article contains extended version the article presented at the conference AEaNMiFMaE 2016.

  10. Experimental investigation of a moving averaging algorithm for motion perpendicular to the leaf travel direction in dynamic MLC target tracking

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jai-Woong; Sawant, Amit; Suh, Yelin; Cho, Byung-Chul; Suh, Tae-Suk; Keall, Paul [Department of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul, Korea 131-700 and Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul, 131-700 (Korea, Republic of); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States) and Department of Radiation Oncology, Asan Medical Center, Seoul, 138-736 (Korea, Republic of); Department of Biomedical Engineering, College of Medicine, Catholic University of Korea, Seoul, 131-700 and Research Institute of Biomedical Engineering, Catholic University of Korea, Seoul, 131-700 (Korea, Republic of); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States) and Radiation Physics Laboratory, Sydney Medical School, University of Sydney, 2006 (Australia)

    2011-07-15

    Purpose: In dynamic multileaf collimator (MLC) motion tracking with complex intensity-modulated radiation therapy (IMRT) fields, target motion perpendicular to the MLC leaf travel direction can cause beam holds, which increase beam delivery time by up to a factor of 4. As a means to balance delivery efficiency and accuracy, a moving average algorithm was incorporated into a dynamic MLC motion tracking system (i.e., moving average tracking) to account for target motion perpendicular to the MLC leaf travel direction. The experimental investigation of the moving average algorithm compared with real-time tracking and no compensation beam delivery is described. Methods: The properties of the moving average algorithm were measured and compared with those of real-time tracking (dynamic MLC motion tracking accounting for both target motion parallel and perpendicular to the leaf travel direction) and no compensation beam delivery. The algorithm was investigated using a synthetic motion trace with a baseline drift and four patient-measured 3D tumor motion traces representing regular and irregular motions with varying baseline drifts. Each motion trace was reproduced by a moving platform. The delivery efficiency, geometric accuracy, and dosimetric accuracy were evaluated for conformal, step-and-shoot IMRT, and dynamic sliding window IMRT treatment plans using the synthetic and patient motion traces. The dosimetric accuracy was quantified via a {gamma}-test with a 3%/3 mm criterion. Results: The delivery efficiency ranged from 89 to 100% for moving average tracking, 26%-100% for real-time tracking, and 100% (by definition) for no compensation. The root-mean-square geometric error ranged from 3.2 to 4.0 mm for moving average tracking, 0.7-1.1 mm for real-time tracking, and 3.7-7.2 mm for no compensation. The percentage of dosimetric points failing the {gamma}-test ranged from 4 to 30% for moving average tracking, 0%-23% for real-time tracking, and 10%-47% for no compensation

  11. Spreading Speed, Traveling Waves, and Minimal Domain Size in Impulsive Reaction–Diffusion Models

    KAUST Repository

    Lewis, Mark A.

    2012-08-15

    How growth, mortality, and dispersal in a species affect the species\\' spread and persistence constitutes a central problem in spatial ecology. We propose impulsive reaction-diffusion equation models for species with distinct reproductive and dispersal stages. These models can describe a seasonal birth pulse plus nonlinear mortality and dispersal throughout the year. Alternatively, they can describe seasonal harvesting, plus nonlinear birth and mortality as well as dispersal throughout the year. The population dynamics in the seasonal pulse is described by a discrete map that gives the density of the population at the end of a pulse as a possibly nonmonotone function of the density of the population at the beginning of the pulse. The dynamics in the dispersal stage is governed by a nonlinear reaction-diffusion equation in a bounded or unbounded domain. We develop a spatially explicit theoretical framework that links species vital rates (mortality or fecundity) and dispersal characteristics with species\\' spreading speeds, traveling wave speeds, as well as minimal domain size for species persistence. We provide an explicit formula for the spreading speed in terms of model parameters, and show that the spreading speed can be characterized as the slowest speed of a class of traveling wave solutions. We also give an explicit formula for the minimal domain size using model parameters. Our results show how the diffusion coefficient, and the combination of discrete- and continuous-time growth and mortality determine the spread and persistence dynamics of the population in a wide variety of ecological scenarios. Numerical simulations are presented to demonstrate the theoretical results. © 2012 Society for Mathematical Biology.

  12. Impact of On-street Parking on Urban Arterial Performance: A Quantitative Study on Travel Speed and Capacity Deterioration

    Directory of Open Access Journals (Sweden)

    Sugiarto

    2013-08-01

    Full Text Available Traffic congestion has been a serious social and technical problem since the early year’s rapid motorization in Banda Aceh, Aceh Province of Indonesia. Urban arterial performance becomes the crucial concerns of many traffic engineers. Arterial performances were analyzed using oblique cumulative plots and breakdown method. The approaches are time series treatment between cumulative vehicles arrival versus time contracted from data recorded by video cameras. Investigations were conducted during both morning and evening peak hours on three regular weekdays for observing saturation condition in order to observe the maximum capacity under prevailing conditions. This study examined the impact of presence on-street parking on deterioration both travel speed and capacity. It found that capacity diminished slightly 10-13% (275-368vph compared to the pre-breakdown condition. Likewise, during the breakdown, speed dropped about 13-19% (3-5kph controlled by pre-breakdown as well. The simulation software so called VISSIM 5.30 was governed to estimate the measurement of effectiveness (MOEs by removing on-street parking from a site of study. The MOEs reveal that removing on-street parking able to reduce average delay approximately 12 sec/veh (32% and increase speed about 5kph (24%.

  13. CUTTING REGULARITY AND DISCHARGE CHARACTERISTICS BY USING COMPOSITE COOLING LIQUID IN WIRE CUT ELECTRICAL DISCHARGE MACHINE WITH HIGH WIRE TRAVELING SPEED

    Institute of Scientific and Technical Information of China (English)

    LIU Zhidong

    2008-01-01

    The analysis of cutting regularity is provided through using and comparing two typical cooling liquids. It is proved that cutting regularity is greatly affected by cooling liquid's washing ability. Discharge characteristics and theoretic analysis between two electrodes are also discussed based on discharge waveform. By using composite cooling liquid which has strong washing ability, the efficiency in the first stable cutting phase has reached more than 200 mm2/min, and the roughness of the surface has reached Ra<0.8 μm after the fourth cutting with more than 50 mm2/min average cutting efficiency. It is pointed out that cutting situation of the wire cut electrical discharge machine with high wire traveling speed (HSWEDM) is better than the wire cut electrical discharge machine with low wire traveling speed (LSWEDM) in the condition of improving the cooling liquid washing ability. The machining indices of HSWEDM will be increased remarkably by using the composite cooling liquid.

  14. Average but not continuous speed match between motoneurons and muscle units of rat tibialis anterior.

    Science.gov (United States)

    Bakels, R; Kernell, D

    1993-10-01

    1. Properties of single motoneuron/muscle-unit combinations were determined for tibialis anterior (TA) in rats anesthetized with pentobarbital. The TA observations were systematically compared with those obtained earlier by the use of the same techniques from rat medial gastrocnemius (MG). 2. TA motoneurons were investigated with regard to afterhyperpolarization (AHP; total duration 32-74 ms, amplitude 0.39-4.96 mV) and axonal conduction velocity (41-79 m/s). TA muscle-unit measurements included the time course of the isometric twitch (time-to-peak force 10.8-18.0 ms; total duration 42-92 ms), the maximum tetanic force (22-217 mN), and a measure of fatigue sensitivity (fatigue index 5-100%). The range of twitch and AHP durations ("speed range") was markedly smaller in the present TA material than for MG. 3. The mean duration of the TA motoneuronal AHP (49 +/- 8 ms, mean +/- SD) was close to that of its muscle-unit twitch (56 +/- 12 ms). Thus an "average" speed match existed between TA motoneurons and their muscle fibers. 4. For TA there was no correlation between the time courses of AHP and twitch. Thus there was for TA no "continuous" speed match between the motoneurons and their muscle fibers. 5. For TA twitches or AHPs studied separately, there was a significant correlation between different time course measures. Furthermore, compared with TA units having relatively fast twitches, those with slower twitches tended to show 1) a smaller maximum tetanic force and 2) a greater AHP amplitude. Fatigue-resistant units tended to have slower twitches than fatigue-sensitive ones.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. MODIFICATION OF CARBON STEEL BY LASER SURFACE MELTING: PART I: EFFECT OF LASER BEAM TRAVELLING SPEED ON MICROSTRUCTURAL FEATURES AND SURFACE HARDNESS

    Directory of Open Access Journals (Sweden)

    Hashem F. El-Labban

    2013-01-01

    Full Text Available The present study aims to improve the surface hardness of carbon steel by application of laser surface melting of effective conditions. The travelling speed of laser beam during this treatment is one of the important treatment conditions. This study aims to investigate the effect of laser surface melting with different beam speeds on macro and microstructure as well as the hardness distribution through the thickness of carbon steel. To achieve this target, three different travelling speeds (1500, 1000 and 500 mm min-1 at a constant beam power of 800 W were chosen in this study. The resulted laser treated specimens were investigated in macro and microscopically scale using optical and scanning electron microscope. Hardness measurements were also carried out through the thickness of the laser treated specimens. The laser treated areas with all used travelling speeds results in melted and solidified zone on the surface of the steel. In the same time, Plates of acicular martensite structure were observed within the upper part of the melted and solidified zone in almost all experimental conditions, while some bainite structure in ferrite grains are detected in its lower part. By increasing the travelling speed, the depth of the laser treated zone was decreases, while travelling speed has much less significant effect on the laser treated zone width. The size of the formed martensite plates was increased by decreasing the travelling speed from 1500 to 500 mm min-1. On the other hand, the travelling speed has a straight effect on the length of the acicular martensite; as the travelling speed increases, the acicular martensite became longer, while it shows fine acicular martensite at lower travelling speeds. The depth that full martensite structure can be reached is increased by increasing travelling speed. At lower travelling speed (500 mm min-1, large amount of bainite structure is observed at the center of the treated zone up to its lower end. The

  16. Effect of Travel Speed on the Stress Corrosion Behavior of Friction Stir Welded 2024-T4 Aluminum Alloy

    Science.gov (United States)

    Wang, Wen; Li, Tianqi; Wang, Kuaishe; Cai, Jun; Qiao, Ke

    2016-05-01

    The effect of travel speed on stress corrosion cracking (SCC) behavior of friction stir welded 2024-T4 aluminum alloy was investigated by slow strain rate tensile test. Microstructure and microhardness of the welded joint were studied. The results showed that the size of second phase particles increased with increasing travel speed, and the distribution of second phase particles was much more homogeneous at lower travel speed. The minimum microhardness was located at the boundary of nugget zone and thermomechanically affected zone. In addition, the SCC susceptibility of the friction stir welded joint increased with the increase of travel speed, owing to the size and distribution of second phase particles in the welds. The anodic applied potentials of -700, -650, -600 mV, and cathodic applied potential of -1200 mV facilitated SCC while the cathodic applied potential of -1000 mV improved the SCC resistance. The SCC behavior was mainly controlled by the metal anodic dissolution at the open circuit potential, and hydrogen accelerated metal embrittlement.

  17. Ultra-High-Speed Travelling Wave Protection of Transmission Line Using Polarity Comparison Principle Based on Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Dong Wang

    2015-01-01

    Full Text Available The traditional polarity comparison based travelling wave protection, using the initial wave information, is affected by initial fault angle, bus structure, and external fault. And the relationship between the magnitude and polarity of travelling wave is ignored. Because of the protection tripping and malfunction, the further application of this protection principle is affected. Therefore, this paper presents an ultra-high-speed travelling wave protection using integral based polarity comparison principle. After empirical mode decomposition of the original travelling wave, the first-order intrinsic mode function is used as protection object. Based on the relationship between the magnitude and polarity of travelling wave, this paper demonstrates the feasibility of using travelling wave magnitude which contains polar information as direction criterion. And the paper integrates the direction criterion in a period after fault to avoid wave head detection failure. Through PSCAD simulation with the typical 500 kV transmission system, the reliability and sensitivity of travelling wave protection were verified under different factors’ affection.

  18. Spreading speed and travelling wave solutions of a partially sedentary population

    Science.gov (United States)

    Volkov, Darko; Lui, Roger

    2007-12-01

    In this paper, we extend the population genetics model of Weinberger (1978, Asymptotic behavior of a model in population genetics. Nonlinear Partial Differential Equations and Applications (J. Chadam ed.). Lecture Notes in Mathematics, vol. 648. New York: Springer, pp. 47-98.) to the case where a fraction of the population does not migrate after the selection process. Mathematically, we study the asymptotic behaviour of solutions to the recursion un+1 = Qg[un], where ... In the above definition of Qg, K is a probability density function and f behaves qualitatively like the Beverton-Holt function. Under some appropriate conditions on K and f, we show that for each unit vector{xi} [isin] Rd, there exists a c*g({xi}) which has an explicit formula and is the spreading speed of Qg in the direction{xi} . We also show that for each c [≥] c*g({xi}), there exists a travelling wave solution in the direction{xi} which is continuous if gf '(0) [≤] 1.

  19. Planar undulator motion excited by a fixed traveling wave: Quasiperiodic Averaging, normal forms and the FEL Pendulum

    CERN Document Server

    Ellison, James A; Vogt, Mathias; Gooden, Matthew

    2013-01-01

    We present a mathematical analysis of planar motion of energetic electrons moving through a planar dipole undulator, excited by a fixed planar polarized plane wave Maxwell field in the X-Ray Free Electron Laser (FEL) regime. Our starting point is the 6D Lorentz system, which allows planar motions, and we examine this dynamical system as the wavelength of the traveling wave varies. By scalings and transformations the 6D system is reduced, without approximation, to a 2D system in a form for a rigorous asymptotic analysis using the Method of Averaging (MoA), a long time perturbation theory. The two dependent variables are a scaled energy deviation and a generalization of the so-called ponderomotive phase. As the wavelength varies the system passes through resonant and nonresonant (NR) zones and we develop NR and near-to-resonant (NtoR) normal form approximations. For a special initial condition and on resonance, the NtoR normal form reduces to the well-known FEL pendulum system. We then state and prove NR and Nt...

  20. Planar undulator motion excited by a fixed traveling wave. Quasiperiodic averaging normal forms and the FEL pendulum

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James A.; Heinemann, Klaus [New Mexico Univ., Albuquerque, NM (United States). Dept. of Mathematics and Statistics; Vogt, Mathias [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Gooden, Matthew [North Carolina State Univ., Raleigh, NC (United States). Dept. of Physics

    2013-03-15

    We present a mathematical analysis of planar motion of energetic electrons moving through a planar dipole undulator, excited by a fixed planar polarized plane wave Maxwell field in the X-Ray FEL regime. Our starting point is the 6D Lorentz system, which allows planar motions, and we examine this dynamical system as the wave length {lambda} of the traveling wave varies. By scalings and transformations the 6D system is reduced, without approximation, to a 2D system in a form for a rigorous asymptotic analysis using the Method of Averaging (MoA), a long time perturbation theory. The two dependent variables are a scaled energy deviation and a generalization of the so- called ponderomotive phase. As {lambda} varies the system passes through resonant and nonresonant (NR) zones and we develop NR and near-to-resonant (NtoR) MoA normal form approximations. The NtoR normal forms contain a parameter which measures the distance from a resonance. For a special initial condition, for the planar motion and on resonance, the NtoR normal form reduces to the well known FEL pendulum system. We then state and prove NR and NtoR first-order averaging theorems which give explicit error bounds for the normal form approximations. We prove the theorems in great detail, giving the interested reader a tutorial on mathematically rigorous perturbation theory in a context where the proofs are easily understood. The proofs are novel in that they do not use a near identity transformation and they use a system of differential inequalities. The NR case is an example of quasiperiodic averaging where the small divisor problem enters in the simplest possible way. To our knowledge the planar prob- lem has not been analyzed with the generality we aspire to here nor has the standard FEL pendulum system been derived with associated error bounds as we do here. We briefly discuss the low gain theory in light of our NtoR normal form. Our mathematical treatment of the noncollective FEL beam dynamics problem in

  1. Are the average gait speeds during the 10meter and 6minute walk tests redundant in Parkinson disease?

    Science.gov (United States)

    Duncan, Ryan P; Combs-Miller, Stephanie A; McNeely, Marie E; Leddy, Abigail L; Cavanaugh, James T; Dibble, Leland E; Ellis, Terry D; Ford, Matthew P; Foreman, K Bo; Earhart, Gammon M

    2017-02-01

    We investigated the relationships between average gait speed collected with the 10Meter Walk Test (Comfortable and Fast) and 6Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r>0.70, pMeter Walk Test (r=0.75) and Fast 10Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II-IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population.

  2. The Effects of the Planned High-Speed Rail System on Travel Times and Spatial Development in the European Alps

    Directory of Open Access Journals (Sweden)

    Elisa Ravazzoli

    2017-02-01

    Full Text Available One of the direct effects of introducing high-speed railway lines is a significant reduction in travel times between major cities. This is particularly relevant in mountain areas. It not only makes cities more easily reachable with more sustainable transport systems but can also encourage different travel behavior and reduce environmental pressures on sensitive areas. A comprehensive analysis of the spatiotemporal effects of the introduction of high-speed railways in the Alpine arc has not yet been developed. To help fill this gap, this study uses multidimensional scaling and the geographical information system to illustrate the time–space compression. This term indicates the erosion of spatial and temporal distances in the areas of the Alps directly affected by the new railway lines. Six trans-Alpine high-speed railway lines are analyzed, comparing current and projected travel times by train. A time-based map is created to show the time–space compression in every transversal direction, particularly on the French and the Austrian side of the Alps. Implications in terms of local accessibility are also analyzed, focusing on the Autonomous Province of Bolzano/Bozen-South Tyrol. Finally, the paper discusses the importance of time-based maps for the understanding of sociospatial dynamics and the possible implications for spatial development.

  3. Rolling element bearing defect diagnosis under variable speed operation through angle synchronous averaging of wavelet de-noised estimate

    Science.gov (United States)

    Mishra, C.; Samantaray, A. K.; Chakraborty, G.

    2016-05-01

    Rolling element bearings are widely used in rotating machines and their faults can lead to excessive vibration levels and/or complete seizure of the machine. Under special operating conditions such as non-uniform or low speed shaft rotation, the available fault diagnosis methods cannot be applied for bearing fault diagnosis with full confidence. Fault symptoms in such operating conditions cannot be easily extracted through usual measurement and signal processing techniques. A typical example is a bearing in heavy rolling mill with variable load and disturbance from other sources. In extremely slow speed operation, variation in speed due to speed controller transients or external disturbances (e.g., varying load) can be relatively high. To account for speed variation, instantaneous angular position instead of time is used as the base variable of signals for signal processing purposes. Even with time synchronous averaging (TSA) and well-established methods like envelope order analysis, rolling element faults in rolling element bearings cannot be easily identified during such operating conditions. In this article we propose to use order tracking on the envelope of the wavelet de-noised estimate of the short-duration angle synchronous averaged signal to diagnose faults in rolling element bearing operating under the stated special conditions. The proposed four-stage sequential signal processing method eliminates uncorrelated content, avoids signal smearing and exposes only the fault frequencies and its harmonics in the spectrum. We use experimental data1

  4. An Analytical and Experimental Investigation of Average Laser Power and Angular Scanning Speed Effects on Laser Tube Bending Process

    Directory of Open Access Journals (Sweden)

    Imhan Khalil Ibraheem

    2017-01-01

    Full Text Available Laser tube bending is a new technique of laser material forming to produce a complex and accurate shape due to its flexibility and high controllability. Moreover, the defects during conventional tube forming such as thinning, wrinkling, spring back and ovalization can be avoided in laser tube bending process, because there is no external force used. In this paper an analytical investigation has been conducted to analyses the effects of average laser power and laser scanning speed on laser tube bending process, the analytical results have been verified experimentally. The model used in this study is in the same trend of the experiment. The results show that the bending angle increased with the increasing of average laser power and decreased with the increasing of angular scanning speed.

  5. High-throughput machining using a high-average power ultrashort pulse laser and high-speed polygon scanner

    Science.gov (United States)

    Schille, Joerg; Schneider, Lutz; Streek, André; Kloetzer, Sascha; Loeschner, Udo

    2016-09-01

    High-throughput ultrashort pulse laser machining is investigated on various industrial grade metals (aluminum, copper, and stainless steel) and Al2O3 ceramic at unprecedented processing speeds. This is achieved by using a high-average power picosecond laser in conjunction with a unique, in-house developed polygon mirror-based biaxial scanning system. Therefore, different concepts of polygon scanners are engineered and tested to find the best architecture for high-speed and precision laser beam scanning. In order to identify the optimum conditions for efficient processing when using high-average laser powers, the depths of cavities made in the samples by varying the processing parameter settings are analyzed and, from the results obtained, the characteristic removal values are specified. For overlapping pulses of optimum fluence, the removal rate is as high as 27.8 mm3/min for aluminum, 21.4 mm3/min for copper, 15.3 mm3/min for stainless steel, and 129.1 mm3/min for Al2O3, when a laser beam of 187 W average laser powers irradiates. On stainless steel, it is demonstrated that the removal rate increases to 23.3 mm3/min when the laser beam is very fast moving. This is thanks to the low pulse overlap as achieved with 800 m/s beam deflection speed; thus, laser beam shielding can be avoided even when irradiating high-repetitive 20-MHz pulses.

  6. The need for speed: testing acceleration for estimating animal travel rates in terrestrial dead-reckoning systems.

    Science.gov (United States)

    Bidder, Owen R; Soresina, Marion; Shepard, Emily L C; Halsey, Lewis G; Quintana, Flavio; Gómez-Laich, Agustina; Wilson, Rory P

    2012-02-01

    Numerous methods are currently available to track animal movements. However, only one of these, dead-reckoning, has the capacity to provide continuous data for animal movements over fine scales. Dead-reckoning has been applied almost exclusively in the study of marine species, in part due to the difficulty of accurately measuring the speed of terrestrial species. In the present study we evaluate the use of accelerometers and a metric known as overall dynamic body acceleration (ODBA) as a proxy for the measurement of speed for use in dead-reckoning. Data were collated from previous studies, for 10 species locomoting on a treadmill and their ODBA measured by an attached data logger. All species except one showed a highly significant linear relationship between speed and ODBA; however, there was appreciable inter- and intra-specific variance in this relationship. ODBA was then used to estimate speed in a simple trial run of a dead-reckoning track. Estimating distance travelled using speed derived from prior calibration for ODBA resulted in appreciable errors. We describe a method by which these errors can be minimised, by periodic ground-truthing (e.g., by GPS or VHF telemetry) of the dead-reckoned track and adjusting the relationship between speed and ODBA until actual known positions and dead-reckoned positions accord.

  7. Traveling waves and spreading speed on a lattice model with age structure

    Directory of Open Access Journals (Sweden)

    Zongyi Wang

    2012-09-01

    Full Text Available In this article, we study a lattice differential model for a single species with distributed age-structure in an infinite patchy environment. Using method of approaches by Diekmann and Thieme, we develop a comparison principle and construct a suitable sub-solution to the given model, and show that there exists a spreading speed of the system which in fact coincides with the minimal wave speed.

  8. Speed hysteresis and noise shaping of traveling fronts in neural fields: role of local circuitry and nonlocal connectivity

    Science.gov (United States)

    Capone, Cristiano; Mattia, Maurizio

    2017-01-01

    Neural field models are powerful tools to investigate the richness of spatiotemporal activity patterns like waves and bumps, emerging from the cerebral cortex. Understanding how spontaneous and evoked activity is related to the structure of underlying networks is of central interest to unfold how information is processed by these systems. Here we focus on the interplay between local properties like input-output gain function and recurrent synaptic self-excitation of cortical modules, and nonlocal intermodular synaptic couplings yielding to define a multiscale neural field. In this framework, we work out analytic expressions for the wave speed and the stochastic diffusion of propagating fronts uncovering the existence of an optimal balance between local and nonlocal connectivity which minimizes the fluctuations of the activation front propagation. Incorporating an activity-dependent adaptation of local excitability further highlights the independent role that local and nonlocal connectivity play in modulating the speed of propagation of the activation and silencing wavefronts, respectively. Inhomogeneities in space of local excitability give raise to a novel hysteresis phenomenon such that the speed of waves traveling in opposite directions display different velocities in the same location. Taken together these results provide insights on the multiscale organization of brain slow-waves measured during deep sleep and anesthesia.

  9. Speed hysteresis and noise shaping of traveling fronts in neural fields: role of local circuitry and nonlocal connectivity

    Science.gov (United States)

    Capone, Cristiano; Mattia, Maurizio

    2017-01-01

    Neural field models are powerful tools to investigate the richness of spatiotemporal activity patterns like waves and bumps, emerging from the cerebral cortex. Understanding how spontaneous and evoked activity is related to the structure of underlying networks is of central interest to unfold how information is processed by these systems. Here we focus on the interplay between local properties like input-output gain function and recurrent synaptic self-excitation of cortical modules, and nonlocal intermodular synaptic couplings yielding to define a multiscale neural field. In this framework, we work out analytic expressions for the wave speed and the stochastic diffusion of propagating fronts uncovering the existence of an optimal balance between local and nonlocal connectivity which minimizes the fluctuations of the activation front propagation. Incorporating an activity-dependent adaptation of local excitability further highlights the independent role that local and nonlocal connectivity play in modulating the speed of propagation of the activation and silencing wavefronts, respectively. Inhomogeneities in space of local excitability give raise to a novel hysteresis phenomenon such that the speed of waves traveling in opposite directions display different velocities in the same location. Taken together these results provide insights on the multiscale organization of brain slow-waves measured during deep sleep and anesthesia. PMID:28045036

  10. Optics. Spatially structured photons that travel in free space slower than the speed of light.

    Science.gov (United States)

    Giovannini, Daniel; Romero, Jacquiline; Potoček, Václav; Ferenczi, Gergely; Speirits, Fiona; Barnett, Stephen M; Faccio, Daniele; Padgett, Miles J

    2015-02-20

    That the speed of light in free space is constant is a cornerstone of modern physics. However, light beams have finite transverse size, which leads to a modification of their wave vectors resulting in a change to their phase and group velocities. We study the group velocity of single photons by measuring a change in their arrival time that results from changing the beam's transverse spatial structure. Using time-correlated photon pairs, we show a reduction in the group velocity of photons in both a Bessel beam and photons in a focused Gaussian beam. In both cases, the delay is several micrometers over a propagation distance of ~1 meter. Our work highlights that, even in free space, the invariance of the speed of light only applies to plane waves.

  11. Speed and income

    DEFF Research Database (Denmark)

    Fosgerau, Mogens

    2005-01-01

    The relationship between speed and income is established in a microeconomic model focusing on the trade-off between travel time and the risk of receiving a penalty for exceeding the speed limit. This is used to determine when a rational driver will choose to exceed the speed limit. The relationship...... between speed and income is found again in the empirical analysis of a cross-sectional dataset comprising 60,000 observations of car trips. This is used to perform regressions of speed on income, distance travelled, and a number of controls. The results are clearly statistically significant and indicate...... an average income elasticity of speed of 0.02; it is smaller at short distances and about twice as large at the longest distance investigated of 200 km....

  12. Intercity Business Travel Characteristics of the Changchun-Jilin High-speed Rail%长吉高铁城际商务客流出行特征

    Institute of Scientific and Technical Information of China (English)

    赵渺希; 刘珺; 周璇; 陈晨

    2014-01-01

    高速铁路已成为城际商务出行的重要交通方式之一。选取长吉高铁出行群体为研究对象开展问卷调查,获取受访者基本信息和出行信息,探索城际商务客流出行特征。首先分析商务和非商务出行群体在社会经济属性、交通行为特征方面的差异。以非商务出行群体为参照,比较分析商务出行群体在区域层面和城市层面的空间分布特征。在区域层面,由于城市功能地位的差异,长春、吉林商务出行目的地在空间分布上呈现明显的不对称性;在城市内部,商务出行具有更为明显的出行目的地,而非商务出行相对离散。最后指出,相关规划应强调以高效的综合交通体系满足城市核心区之间的商务联系,同时在运输组织上进一步降低商务出行时耗。%High-speed rail has become one of the important modes for intercity business travel. Based on the survey of Changchun-Jilin High-speed Rail passengers, this paper investigates the intercity business travel characteristics. The paper first analyzes the differences in socioeconomic characteristics and travel behaviors between business and non-business travel groups, and then compares the spatial distribution characteristics of business travel group at the regional and the urban level using the non-business travel group as a reference. At the region level, there exists significant difference on spatial distribution of busi-ness travel destinations between Changchun and Jilin due to their different functionalities and locations. At the urban level, business travel shows obvious destinations while non-business travel shows relatively dis-perse destinations. Finally, the paper points out that planning should emphasize facilitating business con-nections between urban center areas with high-quality comprehensive transportation systems and further decrease business travel time through effective transportation organization.

  13. Demanda energética de uma semeadora-adubadora em diferentes velocidades de deslocamento e rotações do motor Energy needs of a planter at different travel and engine speeds

    Directory of Open Access Journals (Sweden)

    João Cleber Modernel da Silveira

    2013-03-01

    Full Text Available A velocidade de operação do trator influencia diversos aspectos, entre eles o consumo de combustível, a capacidade operacional e a qualidade de semeadura. Este trabalho teve como objetivo avaliar a demanda energética de um conjunto trator-semeadora-adubadora em sistema plantio direto, em função das velocidades de deslocamento e rotações no eixo do motor, na semeadura da cultura do milho. Os 12 tratamentos foram constituídos de quatro velocidades de deslocamento, obtidas em função dos escalonamentos de marchas e de três rotações do motor do trator. Durante a semeadura, monitoraram-se a velocidade de operação, a rotação do motor, a força de tração e o consumo horário de combustível. Os resultados mostraram que o requerimento de potência na barra de tração, média, por linha de semeadura, por profundidade do sulco e por área mobilizada aumentou com o aumento da velocidade de operação do conjunto mecanizado. O consumo horário de combustível foi elevado com o aumento da velocidade de operação e da rotação do motor, sendo menor na rotação do motor de 1.500 rpm.The operating speed of the tractor influences various aspects, including fuel consumption, operational capacity and sowing quality. This study aimed to assess the energy needs of a tractor-planter when sowing maize in a no-tillage system, according to its travel speed and the rotation speed of the motor shaft. The 12 treatments consisted of four travel speeds, obtained by staggering the gears, and three tractor-engine rotation speeds. During sowing, the speed of operation, engine speed, the traction force and hourly consumption of fuel were monitored. The results showed that the average power requirement on the drawbar per seeding row, groove depth, and worked area, increased with an increase in the operating speeds of the mechanism. Hourly fuel consumption went up with the increase in operating and engine-rotation speeds, being lowest at a speed of 1,500 rpm.

  14. Analyzing the influence of curl speed in fatiguing biceps brachii muscles using sEMG signals and multifractal detrended moving average algorithm.

    Science.gov (United States)

    Marri, Kiran; Swaminathan, Ramakrishnan

    2016-08-01

    In this work, an attempt has been made to analyze surface electromyography (sEMG) signals of fatiguing biceps brachii muscles at different curl speeds using multifractal detrended moving average (MFDMA) algorithm. For this purpose, signals are recorded from fifty eight healthy subjects while performing curl exercise at their comfortable speed until fatigue. The signals of first and last curls are considered as nonfatigue and fatigue conditions, respectively. Further, the number of curls performed by each subject and the endurance time is used for computing the normalized curl speed. The signals are grouped into fast, medium and slow using curl speeds. The curl segments are subjected to MFDMA to derive degree of multifractality (DOM), maximum singularity exponent (MXE) and exponent length multifractality index (EMX). The results show that multifractal features are able to differentiate sEMG signals in fatiguing conditions. The multifractality increased with faster curls as compared with slower curl speed by 12%. High statistical significance is observed using EMX and DOM values between curl speed and fatigue conditions. It appears that this method of analyzing sEMG signals with curl speed can be useful in understanding muscle dynamics in varied neuromuscular conditions and sports medicine.

  15. On the Relationship between Solar Wind Speed, Earthward-Directed Coronal Mass Ejections, Geomagnetic Activity, and the Sunspot Cycle Using 12-Month Moving Averages

    Science.gov (United States)

    Wilson, Robert M.; Hathaway, David H.

    2008-01-01

    For 1996 .2006 (cycle 23), 12-month moving averages of the aa geomagnetic index strongly correlate (r = 0.92) with 12-month moving averages of solar wind speed, and 12-month moving averages of the number of coronal mass ejections (CMEs) (halo and partial halo events) strongly correlate (r = 0.87) with 12-month moving averages of sunspot number. In particular, the minimum (15.8, September/October 1997) and maximum (38.0, August 2003) values of the aa geomagnetic index occur simultaneously with the minimum (376 km/s) and maximum (547 km/s) solar wind speeds, both being strongly correlated with the following recurrent component (due to high-speed streams). The large peak of aa geomagnetic activity in cycle 23, the largest on record, spans the interval late 2002 to mid 2004 and is associated with a decreased number of halo and partial halo CMEs, whereas the smaller secondary peak of early 2005 seems to be associated with a slight rebound in the number of halo and partial halo CMEs. Based on the observed aaM during the declining portion of cycle 23, RM for cycle 24 is predicted to be larger than average, being about 168+/-60 (the 90% prediction interval), whereas based on the expected aam for cycle 24 (greater than or equal to 14.6), RM for cycle 24 should measure greater than or equal to 118+/-30, yielding an overlap of about 128+/-20.

  16. The Parallel Worm Tracker: a platform for measuring average speed and drug-induced paralysis in nematodes.

    Directory of Open Access Journals (Sweden)

    Daniel Ramot

    Full Text Available BACKGROUND: Caenorhabditis elegans locomotion is a simple behavior that has been widely used to dissect genetic components of behavior, synaptic transmission, and muscle function. Many of the paradigms that have been created to study C. elegans locomotion rely on qualitative experimenter observation. Here we report the implementation of an automated tracking system developed to quantify the locomotion of multiple individual worms in parallel. METHODOLOGY/PRINCIPAL FINDINGS: Our tracking system generates a consistent measurement of locomotion that allows direct comparison of results across experiments and experimenters and provides a standard method to share data between laboratories. The tracker utilizes a video camera attached to a zoom lens and a software package implemented in MATLAB. We demonstrate several proof-of-principle applications for the tracker including measuring speed in the absence and presence of food and in the presence of serotonin. We further use the tracker to automatically quantify the time course of paralysis of worms exposed to aldicarb and levamisole and show that tracker performance compares favorably to data generated using a hand-scored metric. CONCLUSIONS/SIGNIFICANCE: Although this is not the first automated tracking system developed to measure C. elegans locomotion, our tracking software package is freely available and provides a simple interface that includes tools for rapid data collection and analysis. By contrast with other tools, it is not dependent on a specific set of hardware. We propose that the tracker may be used for a broad range of additional worm locomotion applications including genetic and chemical screening.

  17. High speed laser drilling of metals using a high repetition rate, high average power ultrafast fiber CPA system.

    Science.gov (United States)

    Ancona, A; Röser, F; Rademaker, K; Limpert, J; Nolte, S; Tünnermann, A

    2008-06-09

    We present an experimental study on the drilling of metal targets with ultrashort laser pulses at high repetition rates (from 50 kHz up to 975 kHz) and high average powers (up to 68 Watts), using an ytterbium-doped fiber CPA system. The number of pulses to drill through steel and copper sheets with thicknesses up to 1 mm have been measured as a function of the repetition rate and the pulse energy. Two distinctive effects, influencing the drilling efficiency at high repetition rates, have been experimentally found and studied: particle shielding and heat accumulation. While the shielding of subsequent pulses due to the ejected particles leads to a reduced ablation efficiency, this effect is counteracted by heat accumulation. The experimental data are in good qualitative agreement with simulations of the heat accumulation effect and previous studies on the particle emission. However, for materials with a high thermal conductivity as copper, both effects are negligible for the investigated processing parameters. Therefore, the full power of the fiber CPA system can be exploited, which allows to trepan high-quality holes in 0.5mm-thick copper samples with breakthrough times as low as 75 ms.

  18. Study on the saturation characteristics of high-speed uni-traveling-carrier photodiodes based on field screening analysis

    Institute of Scientific and Technical Information of China (English)

    Tuo Shi; Bing Xiong; Changzheng Sun; Yi Luo

    2011-01-01

    A back-illuminated mesa-Structure InGaAs/InP charge-compensated uni-traveling-carrier (UTC) photodi-ode (PD) is fabricated, and its saturation characteristics are investigated. The responsivity of the 40-μm-diameter PD is as high as 0.83 A/W, and the direct current (DC) saturation current is up to 275 mA. The 1-dB compression point at the 3-dB cutoff frequency of 9 GHz is measured to be 100 mA, corresponding to an output radio frequency (RP) power of up to 20.1 dBm. According to the calculated electric field distributions in the depleted region under both DC and alternating current (AC) conditions, the saturation of the UTC-PD is caused by complete field screening at high optical injection levels.%@@ A back-illuminated mesa-structure InGaAs/InP charge-compensated uni-traveling-carrier(UTC) photodiode(PD) is fabricated,and its saturation characteristics are investigated.The responsivity of the 40-μmdiameter PD is as high as 0.83 A/W,and the direct current(DC) saturation current is up to 275 Ma.

  19. Choice of best possible metaheuristic algorithm for the travelling salesman problem with limited computational time: quality, uncertainty and speed

    Directory of Open Access Journals (Sweden)

    Marek Antosiewicz

    2013-04-01

    Full Text Available We compare six metaheuristic optimization algorithms applied to solving the travelling salesman problem. We focus on three classical approaches: genetic algorithms, simulated annealing and tabu search, and compare them with three recently developed ones: quantum annealing, particle swarm optimization and harmony search. On top of that we compare all results with those obtained with a greedy 2-opt interchange algorithm. We are interested in short-term performance of the algorithms and use three criteria to evaluate them: solution quality, standard deviation of results and time needed to reach the optimum. Following the results from simulation experiments we conclude that simulated annealing and tabu search outperform newly developed approaches in short simulation runs with respect to all three criteria. Simulated annealing finds best solutions, yet tabu search has lower variance of results and converges faster.

  20. Modified Motor Vehicles Travel Speed Models on the Basis of Curb Parking Setting under Mixed Traffic Flow

    Directory of Open Access Journals (Sweden)

    Zhenyu Mei

    2012-01-01

    Full Text Available The ongoing controversy about in what condition should we set the curb parking has few definitive answers because comprehensive research in this area has been lacking. Our goal is to present a set of heuristic urban street speed functions under mixed traffic flow by taking into account impacts of curb parking. Two impacts have been defined to classify and quantify the phenomena of motor vehicles' speed dynamics in terms of curb parking. The first impact is called Space impact, which is caused by the curb parking types. The other one is the Time impact, which results from the driver maneuvering in or out of parking space. In this paper, based on the empirical data collected from six typical urban streets in Nanjing, China, two models have been proposed to describe these phenomena for one-way traffic and two-way traffic, respectively. An intensive experiment has been conducted in order to calibrate and validate these proposed models, by taking into account the complexity of the model parameters. We also provide guidelines in terms of how to cluster and calculate those models' parameters. Results from these models demonstrated promising performance of modeling motor vehicles' speed for mixed traffic flow under the influence of curb parking.

  1. Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

    1989-04-01

    This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

  2. Fabrication and characterization of novel high-speed InGaAs/InP uni-traveling-carrier photodetector for high responsivity

    Institute of Scientific and Technical Information of China (English)

    陈庆涛; 任晓敏; 黄永清; 费嘉瑞; 段晓峰; 刘凯; 刘锋; 康超; 汪君楚; 房文敬

    2015-01-01

    A top-illuminated circular mesa uni-traveling-carrier photodetector (UTC-PD) is proposed in this paper. By employ-ing Gaussian graded doping in InGaAs absorption layer and InP depleted layer, the responsivity and high speed response characteristics of the device are optimized simultaneously. The responsivity up to 1.071 A/W (the external quantum effi-ciency of 86%) is obtained at 1550 nm with a 40-µm diameter device under 10-V reverse bias condition. Meanwhile, the dark current of 7.874 nA and the 3-dB bandwidth of 11 GHz are obtained with the same device at a reverse bias voltage of 3V.

  3. Travelers' Health: Water Disinfection for Travelers

    Science.gov (United States)

    ... Water Disinfection Infographics for Travelers MERS Health Advisory poster Food and Water: What's Safer Health Advisory: MERS ... prevent recontamination during storage Table 2-10. Microorganism size and susceptibility to filtration ORGANISM AVERAGE SIZE (µm) ...

  4. 浅析武广“高铁旅游生态圈”的构建策略及保障机制%Analysis on the Building Strategies and Protection Mechanisms of Wuhan- Guangzhou "High- speed Rail Travel Ecosystem"

    Institute of Scientific and Technical Information of China (English)

    方微

    2012-01-01

    中国高铁的快速发展催生出新时代高铁旅游的发展,关于通过构建高铁旅游生态圈来推动高铁沿线城市旅游发展的讨论和研究开始进入视野。本文以武广高铁为载体,建立联动广东、湖南、湖北旅游的高铁旅游生态圈,从树立“粤湘鄂”旅游品牌、交通服务体系、旅游服务系统、加强旅游产品创新等方面探讨了构建武广高铁旅游生态圈的策略,并提出相应的保障机制,激发粤、湘、鄂旅游在高铁时代发展的新活力。%The rapid development of Chinab high - speed rail spawned the development of high - speed rail travel of a new era, discussions and researches on high - speed railway line to promote urban tourism development by building high - speed rail travel ecosystem began to enter people's field of vision. With Wuhan - Guangzhou high - speed rail as a carrier, this article builds the high speed rail travel ecosystem among the linkage of Guangdong, Hunan and Hubei, and discusses the strategy of building eco - tourism circle of Wuhan - Guangzhou high - speed rail from establishing tourism brand of " Guangdong, Hunan, Hubei" , traffic service system, tourism service sys- tem, and strengthening the tourism product innovation and so on. Finally, the article puts forward corresponding security mechanisms to stimulate new vitality of Guangdong, Hunan and Hubei tourism development high - speed rail in the era.

  5. 高铁时代旅行社面临的机遇和挑战%Opportunities and challenges that travel agency face in the high speed railway ages

    Institute of Scientific and Technical Information of China (English)

    何忠诚; 朱慧

    2012-01-01

    The extraordinary development of China's high speed railway and the formation of high speed railway's tourism city circle and city belt have a significant impact on China's travel agencies.The article analyzes the opportunities of travel agencies in the age of the high speed railway: the increasing number of travelers provides broad and potential market space for the travel agencies;the high speed railway provides important prerequisites for travel agencies to develop more and deeper tourist routes;the outbound travel bureaus will have the growth of potential customers;the condition of low season will be improved.At the same time,the article points out the challenges that travel agencies will confront:the visitors will reduce their dependence on travel agencies;most travel agencies which develop new tourism products and lines will feel difficult and beyond their ability;the travel agencies's income of air ticketing business will be affected;the service reception capacity will encounter comprehensive tests.Thus,the paper proposes the corresponding countermeasures and suggestions:it's imperative to build the vertical division system;the travel agencies should revolve around the high speed railway to design and develop tourism products.The reception capacity should be improved,especially we should strengthen the management and training to the guides.%高铁在中国的超常规发展以及高铁旅游城市圈和城市带的形成,对我国旅行社的发展产生重要的影响。文章分析了高铁时代旅行社面临的机遇,即出游人数增多,为旅行社提供了广阔的潜在市场空间;为旅行社开发更多、更深层次的旅游线路,提供了重要先决条件;出境组团旅行社将会迎来客源的增长;旅行社旅游淡季的状况将得到改善。同时指出旅行社还将面临着挑战,即游客对旅行社的依赖减少;多数旅行社开发新旅游产品和线路是心有余而力不足;旅行社航空票务代

  6. Determination of hydrologic properties needed to calculate average linear velocity and travel time of ground water in the principal aquifer underlying the southeastern part of Salt Lake Valley, Utah

    Science.gov (United States)

    Freethey, G.W.; Spangler, L.E.; Monheiser, W.J.

    1994-01-01

    A 48-square-mile area in the southeastern part of the Salt Lake Valley, Utah, was studied to determine if generalized information obtained from geologic maps, water-level maps, and drillers' logs could be used to estimate hydraulic conduc- tivity, porosity, and slope of the potentiometric surface: the three properties needed to calculate average linear velocity of ground water. Estimated values of these properties could be used by water- management and regulatory agencies to compute values of average linear velocity, which could be further used to estimate travel time of ground water along selected flow lines, and thus to determine wellhead protection areas around public- supply wells. The methods used to estimate the three properties are based on assumptions about the drillers' descriptions, the depositional history of the sediments, and the boundary con- ditions of the hydrologic system. These assump- tions were based on geologic and hydrologic infor- mation determined from previous investigations. The reliability of the estimated values for hydro- logic properties and average linear velocity depends on the accuracy of these assumptions. Hydraulic conductivity of the principal aquifer was estimated by calculating the thickness- weighted average of values assigned to different drillers' descriptions of material penetrated during the construction of 98 wells. Using these 98 control points, the study area was divided into zones representing approximate hydraulic- conductivity values of 20, 60, 100, 140, 180, 220, and 250 feet per day. This range of values is about the same range of values used in developing a ground-water flow model of the principal aquifer in the early 1980s. Porosity of the principal aquifer was estimated by compiling the range of porosity values determined or estimated during previous investigations of basin-fill sediments, and then using five different values ranging from 15 to 35 percent to delineate zones in the study area that were assumed to

  7. Connected Traveler

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Alex

    2015-11-01

    The Connected Traveler project is a multi-disciplinary undertaking that seeks to validate potential for transformative transportation system energy savings by incentivizing efficient traveler behavior. This poster outlines various aspects of the Connected Traveler project, including market opportunity, understanding traveler behavior and decision-making, automation and connectivity, and a projected timeline for Connected Traveler's key milestones.

  8. Behavioural effects of fixed speed cameras on motorways: overall improved speed compliance or kangaroo jumps?

    Science.gov (United States)

    De Pauw, Ellen; Daniels, Stijn; Brijs, Tom; Hermans, Elke; Wets, Geert

    2014-12-01

    The present study evaluates the speed effects of fixed speed cameras on motorways. Two locations with speed cameras were extensively examined in a quasi-experiment: (1) a two-lane motorway and (2) a three-lane motorway, each with a posted speed limit of 120 km/h and sited in Flanders, Belgium. The effect is analysed through a before-and-after comparison of travel speeds. General time trends and fluctuations were controlled through the analysis of the speeds at comparison locations. At each of the two roads, data were gathered at five measurement points from 3 km upstream to 3.8 km downstream of the camera. Three outcomes were analysed: (1) average speed, (2) the odds of drivers exceeding the speed limit and (3) the odds of drivers exceeding the speed limit by more than 10%. Speeds decreased on average by 6.4 km/h at the camera locations. Both the odds of drivers exceeding the speed limit (-80%) and the odds of drivers exceeding the speed limit by more than 10% (-86%) decreased considerably. However, before and beyond the cameras the speeds hardly, if at all, reduced. Moreover, the analyses of the speed profiles before and beyond the cameras show that drivers do slow down quite abruptly before the camera and speed up again after passing the camera. It is concluded that a V-profile is found in the spatial speed distribution for both locations.

  9. Speeding Up

    Institute of Scientific and Technical Information of China (English)

    YU SHUJUN

    2010-01-01

    In the wake of the global financial crisis, China has amazed the world with the speed of its economic recovery. But what has been even more surprising is the speed of its railway evolution. The unveiling of the 1,069-km Wuhan-Guangzhou High-speed Railway on December 26, 2009 pushed China's high-speed rail sys-tem-the total mileage, the average speed and the technology-to rank first in the world almost overnight.

  10. Averaged Propulsive Body Acceleration (APBA) Can Be Calculated from Biologging Tags That Incorporate Gyroscopes and Accelerometers to Estimate Swimming Speed, Hydrodynamic Drag and Energy Expenditure for Steller Sea Lions.

    Science.gov (United States)

    Ware, Colin; Trites, Andrew W; Rosen, David A S; Potvin, Jean

    2016-01-01

    Forces due to propulsion should approximate forces due to hydrodynamic drag for animals horizontally swimming at a constant speed with negligible buoyancy forces. Propulsive forces should also correlate with energy expenditures associated with locomotion-an important cost of foraging. As such, biologging tags containing accelerometers are being used to generate proxies for animal energy expenditures despite being unable to distinguish rotational movements from linear movements. However, recent miniaturizations of gyroscopes offer the possibility of resolving this shortcoming and obtaining better estimates of body accelerations of swimming animals. We derived accelerations using gyroscope data for swimming Steller sea lions (Eumetopias jubatus), and determined how well the measured accelerations correlated with actual swimming speeds and with theoretical drag. We also compared dive averaged dynamic body acceleration estimates that incorporate gyroscope data, with the widely used Overall Dynamic Body Acceleration (ODBA) metric, which does not use gyroscope data. Four Steller sea lions equipped with biologging tags were trained to swim alongside a boat cruising at steady speeds in the range of 4 to 10 kph. At each speed, and for each dive, we computed a measure called Gyro-Informed Dynamic Acceleration (GIDA) using a method incorporating gyroscope data with accelerometer data. We derived a new metric-Averaged Propulsive Body Acceleration (APBA), which is the average gain in speed per flipper stroke divided by mean stroke cycle duration. Our results show that the gyro-based measure (APBA) is a better predictor of speed than ODBA. We also found that APBA can estimate average thrust production during a single stroke-glide cycle, and can be used to estimate energy expended during swimming. The gyroscope-derived methods we describe should be generally applicable in swimming animals where propulsive accelerations can be clearly identified in the signal-and they should also

  11. Exploratory analysis of travel speed based on floating car data%浮动车行程速度探索性分析

    Institute of Scientific and Technical Information of China (English)

    刘兴权; 欧阳俊; 陆锋; 段滢滢

    2012-01-01

    Urban transport system is a participatory, dynamic and open complex system. Conventional statistical methods such as mean and variance can no longer describe and discover potential characteristics of urban traffic flow* Furthermore, although existing mathematical models have been presented to reveal quantitatively nonlinear dynamics and chaos mechanism of traffic flows, it is still unavailable in practice because of its complicated expressions and lack of accuracy and flexibility. In this paper, exploratory analysis of travel speed based on the floating car data was discussed, and examined using real data sets of the fifth ring roadway sections in Beijing. This paper presented an exploratory analysis method for traffic anomaly detection based on quantile that conducts strong anti-disturbance and robustness performance. The results of applications showed that the proposed idea was feasible and effective, and could provide a referencial perspective on studying characteristics of traffic flow, especially traffic anomaly detection.%城市交通系统是一个有人参与的、动态的和开放的复杂系统.传统的均值、方差等统计方法已难以直观地表达和发现城市交通流的潜在特征.而目前基于确定的交通流数学模型虽然能定量地揭示其非线性动力学特征,但存在着表达式复杂却精确度不够且灵活性欠缺和通用性不强的问题.本文探讨了城市行车速度的探索性分析方法的可行性,并以北京市四环内路段行车速度为例进行试验,结果表明,浮动车行车速度的探索性分析方法是有效的和实用的,可为交通流的特征分析特别是实时交通异常检测的研究提供参考思路.

  12. [Travelers' vaccines].

    Science.gov (United States)

    Ouchi, Kazunobu

    2011-09-01

    The number of Japanese oversea travelers has gradually increased year by year, however they usually pay less attention to the poor physical condition at the voyage place. Many oversea travelers caught vaccine preventable diseases in developing countries. The Vaccine Guideline for Oversea Travelers 2010 published by Japanese Society of Travel Health will be helpful for spreading the knowledge of travelers' vaccine and vaccine preventable diseases in developing countries. Many travelers' vaccines have not licensed in Japan. I hope these travelers' vaccines, such as typhoid vaccine, meningococcal vaccine, cholera vaccine and so on will be licensed in the near future.

  13. Virtual speed sensors based algorithm for expressway traffic state estimation

    Institute of Scientific and Technical Information of China (English)

    XU DongWei; DONG HongHui; JIA LiMin; QIN Yong

    2012-01-01

    The accurate estimation of expressway traffic state can provide decision-making for both travelers and traffic managers.The speed is one of the most representative parameter of the traffic state.So the expressway speed spatial distribution can be taken as the expressway traffic state equivalent.In this paper,an algorithm based on virtual speed sensors (VSS) is presented to estimate the expressway traffic state (the speed spatial distribution).To gain the spatial distribution of expressway traffic state,virtual speed sensors are defined between adjacent traffic flow sensors.Then,the speed data extracted from traffic flow sensors in time series are mapped to space series to design virtual speed sensors.Then the speed of virtual speed sensors can be calculated with the weight matrix which is related with the speed of virtual speed sensors and the speed data extracted from traffic flow sensors and the speed data extracted from traffic flow sensors in time series.Finally,the expressway traffic state (the speed spatial distribution) can be gained.The acquisition of average travel speed of the expressway is taken for application of this traffic state estimation algorithm.One typical expressway in Beijing is adopted for the experiment analysis.The results prove that this traffic state estimation approach based on VSS is feasible and can achieve a high accuracy.

  14. Validation of travel times to hospital estimated by GIS

    Directory of Open Access Journals (Sweden)

    Sauerzapf Violet

    2006-09-01

    Full Text Available Abstract Background An increasing number of studies use GIS estimates of car travel times to health services, without presenting any evidence that the estimates are representative of real travel times. This investigation compared GIS estimates of travel times with the actual times reported by a sample of 475 cancer patients who had travelled by car to attend clinics at eight hospitals in the North of England. Methods Car travel times were estimated by GIS using the shortest road route between home address and hospital and average speed assumptions. These estimates were compared with reported journey times and straight line distances using graphical, correlation and regression techniques. Results There was a moderately strong association between reported times and estimated travel times (r = 0.856. Reported travel times were similarly related to straight line distances. Altogether, 50% of travel time estimates were within five minutes of the time reported by respondents, 77% were within ten minutes and 90% were within fifteen minutes. The distribution of over- and under-estimates was symmetrical, but estimated times tended to be longer than reported times with increasing distance from hospital. Almost all respondents rounded their travel time to the nearest five or ten minutes. The reason for many cases of reported journey times exceeding the estimated times was confirmed by respondents' comments as traffic congestion. Conclusion GIS estimates of car travel times were moderately close approximations to reported times. GIS travel time estimates may be superior to reported travel times for modelling purposes because reported times contain errors and can reflect unusual circumstances. Comparison with reported times did not suggest that estimated times were a more sensitive measure than straight line distance.

  15. 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.

  16. State Averages

    Data.gov (United States)

    U.S. Department of Health & Human Services — A list of a variety of averages for each state or territory as well as the national average, including each quality measure, staffing, fine amount and number of...

  17. 1961~2010年河西地区平均风速时空变化趋势分析%Spatial and Temporal Trends of Average Wind Speed in Hexi Area in 1961-2010

    Institute of Scientific and Technical Information of China (English)

    张克新; 潘少明; 曹立国

    2014-01-01

    利用河西地区15个气象站点1961~2010年月平均风速和最大风速日值资料,采用M-K突变检验、ArcGIS中的IDW插值和小波分析等方法分析河西地区平均风速的时空变化趋势。结果表明:近50 a来,河西地区年平均风速呈明显下降趋势,其递减速率为0.14 m/( s•10 a)(α=0.001);该地区四季平均风速均呈减少趋势且减少趋势相同;平均风速的变化在空间分布上存在差异,具体表现为年平均风速的递减趋势是自西向东逐渐减小,瓜州和玉门是该地区减幅最大的区域,而乌鞘岭却呈现出微增的趋势;风速的长期变化具有一定的突变性,其年平均风速在1985年发生突变;该地区平均风速存在存在多尺度的周期结构特性,其变化周期为6、19和25 a。%Hexi area is characterized with a vulnerable ecological system and severe soil erosion in the north-west of China. Analyzing the trend of the average wind speed is critical for wind resources management and soil erosion control in this region. Based on the monthly average wind speed of the 15 weather stations in Hexi area from 1961 to 2010 and using the methods of climate trending rate, 5 years running mean tread, Inverse Distance Weighted interpolation, Mann-Kendall abrupt change test and wavelet analysis method, the spatial and temporal trends of the average wind speed as well as the possible influential factors were analyzed in Hexi area of Gansu Province from 1961 to 2010. The main results are as follows:1) The annual average wind speed was 2.9 m/s in Hexi area. The annual average wind speed obviously decreased at the rate of approximately 0.14m/(s·10 a) (α=0.001) in Hexi area during the period of 1961-2010. Furthermore, on the seasonal scale, the decreased rate of four seasons was similar. The mainly reason why the annual average wind speed decreased significantly was that the frequency of 5 or more than 5 levels of wind have decreased over recent

  18. Towards a Metropolitan Fundamental Diagram Using Travel Survey Data.

    Science.gov (United States)

    Wang, Kai; Levinson, David M

    2016-01-01

    Using travel diary data from 2000-2001 and 2010-2012 this research examines fundamental traffic relationships at the metropolitan level. The results of this paper can help to explain the causes of some traffic phenomena. Network average speed by time of day can be explained by trip length and cumulative number of vehicles on the road. A clockwise hysteresis loop is found in the Metropolitan Fundamental Diagram in the morning period and a reverse process happens in the afternoon.

  19. Study of speed endurance middle distance runners

    Directory of Open Access Journals (Sweden)

    Golovaschenko R.V.

    2013-12-01

    Full Text Available Purpose : To investigate the boost performance speed endurance runners who specialize in middle-distance running . Material and methods : The study involved team members Vinnytsia region in an amount of 44 people, whose average age was 20,2 ± 2,1 years. Classes are held during the 21-day mesocycle, 5 times a week, twice a day. Things were aimed at enhancing the development of indicators of special speed endurance. Results : The dynamics of the running speed of the model segments that characterize speed endurance athletes. Proved that the improved running 400 meter intervals helps reduce travel time competitive distance of 1500 meters. Conclusion : The use of the program contributes to higher speed endurance, which determines the result in the women's 1,500 meters.

  20. Travel Mode Detection Exploiting Cellular Network Data

    Directory of Open Access Journals (Sweden)

    Kalatian Arash

    2016-01-01

    Full Text Available There has been growing interest in exploiting cellular network data for transportation planning purposes in recent years. In this paper, we utilize these data for determining mode of travel in the city of Shiraz, Iran. Cellular data records -including location updates in 5minute time intervals- of 300,000 users from the city of Shiraz has been collected for 40 hours in three consecutive days in a cooperation with the major telecommunications service provider of the country. Depending on the density of mobile BTS’s in different zones of the city, the user location can be located within an average of 200 meters. Considering data filtering and smoothing, data preparation and converting them to comprehensible traces is a large portion of the work. A novel approach to identify stay locations is proposed and implemented in this paper. Origin-Destination matrices are then created based on trips detected, which shows acceptable consistency with current O-D matrices. Finally, Travel times for all trips of a user is estimated as the main attribute for clustering. Trips between same origin and destination zones are combined together in a group. Using K-means algorithm, records within each group are the portioned in two or three clusters, based on their travel speeds. Each cluster represents a certain mode of travel; walking, public transportation or driving a private car.

  1. Travel patterns in China.

    Directory of Open Access Journals (Sweden)

    Tini Garske

    Full Text Available The spread of infectious disease epidemics is mediated by human travel. Yet human mobility patterns vary substantially between countries and regions. Quantifying the frequency of travel and length of journeys in well-defined population is therefore critical for predicting the likely speed and pattern of spread of emerging infectious diseases, such as a new influenza pandemic. Here we present the results of a large population survey undertaken in 2007 in two areas of China: Shenzhen city in Guangdong province, and Huangshan city in Anhui province. In each area, 10,000 randomly selected individuals were interviewed, and data on regular and occasional journeys collected. Travel behaviour was examined as a function of age, sex, economic status and home location. Women and children were generally found to travel shorter distances than men. Travel patterns in the economically developed Shenzhen region are shown to resemble those in developed and economically advanced middle income countries with a significant fraction of the population commuting over distances in excess of 50 km. Conversely, in the less developed rural region of Anhui, travel was much more local, with very few journeys over 30 km. Travel patterns in both populations were well-fitted by a gravity model with a lognormal kernel function. The results provide the first quantitative information on human travel patterns in modern China, and suggest that a pandemic emerging in a less developed area of rural China might spread geographically sufficiently slowly for containment to be feasible, while spatial spread in the more economically developed areas might be expected to be much more rapid, making containment more difficult.

  2. Travelling diabetics.

    Science.gov (United States)

    Chełmińska, Katarzyna; Jaremin, Bogdan

    2002-01-01

    During the past several decades, the number of both business and tourist travels has greatly increased. Among them are persons suffering from chronic diseases, including diabetics for whom travels pose the additional health-hazard. Irrespective of better education, self-control and constantly improving quality of specialistic equipment available, diabetics still are the group of patients requiring particular attention. In the case of travelling diabetics, problems may occur concerning the transport and storage of insulin, as well as control of glycaemia, all caused by irregularity of meals, variable diet, physical activity, stress, kinetosis (sea voyages), and the change of time zones. The travel may as well evoke ailments caused by the change of climate and concomitant diseases such as traveller's diarrhoea, malaria, etc. Apart from avoiding glycaemia fluctuations, important for retaining health of diabetics is the prevention of other diseases and carrying the necessary drugs.

  3. Travelers' Health: Travel and Breastfeeding

    Science.gov (United States)

    ... I J K L M N O P Q R S T U V W X Y Z # ... search/groups ). Mothers who plan to use a breast pump while traveling may need an electrical current ... during travel because exclusive breastfeeding means feeding only breast milk, no other foods or drinks, which protects ...

  4. [Travel medicine].

    Science.gov (United States)

    Schubert, S; Grimm, M

    2009-07-01

    Travel medicine deals with travellers' diseases. The target group is therefore distinct from tropical medicine. It has gained in significance due to the increase in tourism and professional work abroad in the last 50 years. Dangerous and widespread diseases in tropical countries, in particular tropical malaria, have come into focus in industrialized countries because of their appearance in travellers. Travel medicine deals not only with infectious or transmittable diseases, but also with the ability of patients with chronic diseases to travel, the medical aspects of flying, as well as the health hazards of professional work or high-risk sports abroad. The risk of disease as a result of travelling can be minimized by advice and prophylactic measures, such as vaccinations and drug prophylaxis against malaria, if indicated. On return, medical symptoms should be investigated promptly to ensure early detection of life-threatening disease courses, particularly tropical malaria, as well as to prevent the occurrence of small-scale epidemics. A small number of diseases can also emerge after several years, such as benign types of malaria, amoebic liver abscess and visceral leishmaniasis (kala-azar). Aids also belongs to these diseases. Therefore, in this era of HIV pandemic travellers concerned should be made aware of the risks.

  5. Zero Energry Travel

    CERN Document Server

    Ahmad, Othman; Chekima, Ali

    2011-01-01

    It is fundamentally possible to travel with zero energy based on Newton Laws of Motion. According to the first law of motion, a body will continue to travel for infinite distance unless it is acted upon by another force. For a body in motion, the force which stops perpetual motion is friction. However, there are many circumstances that friction is zero, for example in space, where there is vacuum. On earth, gravity makes objects to be in constant contact with each other generating friction but technology exists to separate them in the air using powerful magnetic forces. At low speeds, the friction caused by air is minimal but we can create vacuum even on land for high speed travel. Another condition for travelling is for it to stop at its destination. On land, we can recover the kinetic energy back into electrical energy using brushless permanent magnet generators. These generators can also convert electric energy into kinetic energy in order to provide motion. This article reviews technologies that will allo...

  6. TRAVEL INFORMATION

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Mauritius Travel From August 31 to September 6, a high- level government delegation from Mauritius visited China. The delegation was headed by the President of Mauritius, Sir Anerood Jugnauth, and included the Minister of Tourism,

  7. 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...

  8. Travelers' Health: Cruise Ship Travel

    Science.gov (United States)

    ... Water Disinfection Infographics for Travelers MERS Health Advisory poster Food and Water: What's Safer Health Advisory: MERS ... cruise ships can vary widely depending on ship size, itinerary, length of cruise, and passenger demographics. Generally, ...

  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 tourist

  10. Travel Fever

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China to become the world’s No.1 tourist destination by 2015 May 19 is a special day in China’s history. On that day 400 years ago,Xu Xiake (1587-1641),wellknown geographer,traveler and explorer of the Ming Dynasty (1368-1644),started a lifelong journey,leading to the publication of the monumental Xu Xiake’s Travel Notes,known for its detailed and accurate geographical information. The book also provided valuable insight into local customs and habits.

  11. Time travel?

    CERN Document Server

    Deser, Stanley D; Deser, Stanley; Jackiw, Roman

    1992-01-01

    To travel into the past, to observe it, perhaps to influence it and correct mistakes of one's youth, has been an abiding fantasy of mankind for as long as we have been aware of a past. Here are described some recent scientific investigations on this topic.

  12. Traveler's Diarrhea

    Science.gov (United States)

    ... probably safe to eat or drink the following:Soft drinks that are carbonated (such as cola).Hot drinks, ... for Staying HealthyInternational travel has its share of health and safety challenges. Talk to your doctor about the area ...

  13. Empirical Study of Travel Time Estimation and Reliability

    OpenAIRE

    Ruimin Li; Huajun Chai; Jin Tang

    2013-01-01

    This paper explores the travel time distribution of different types of urban roads, the link and path average travel time, and variance estimation methods by analyzing the large-scale travel time dataset detected from automatic number plate readers installed throughout Beijing. The results show that the best-fitting travel time distribution for different road links in 15 min time intervals differs for different traffic congestion levels. The average travel time for all links on all days can b...

  14. Effectiveness of Motorcycle speed controlled by speed hump

    Directory of Open Access Journals (Sweden)

    Pornsiri Urapa

    2014-09-01

    Full Text Available Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road.

  15. Revenue Management Model for High-Speed Railway Based on Traveler Choice%基于旅客选择的高速铁路客运收益管理研究

    Institute of Scientific and Technical Information of China (English)

    张力; 蓝伯雄

    2012-01-01

    本文旨在探讨收益管理在高速铁路客运中的应用,给出了存在多级票价时,考虑旅客选择行为的铁路客运收益管理模型,优化结果能够同时给出发车指令和座位出售限制.利用模拟数据对模型进行了数值试验,表明在不同路段长度下,考虑旅客选择行为的总收益较需求独立模型均有所提高,且随着票价等级增多而增长.%This paper deals with the application of revenue management to high-speed railway industry. We present a railway passenger revenue management model considering traveler choice behavior in case of multi-fare. The result gives the booking limits of each fare class and train scheduling as well. Numerical experiments on simulation data show that total revenue of the choice model is higher than those of independent demand, and surges with the increase of fare classes.

  16. [Pregnancy and traveling].

    Science.gov (United States)

    Walentiny, C

    2009-03-01

    The second trimester is the safest time for travelling, because the pregnant woman feels generally most at ease and the risk of spontaneous abortion and pre-term labour is very low. Possible risks must be discussed with the obstetrician before travelling. If the pregnancy is uncomplicated most airlines allow flying up to the 36th (domestic flights) and 35th (international flights) week of gestation. Unless the fetal oxygen supply is already impaired at ground level due to an underlying disease, flying does not pose a risk of fetal hypoxia. Radiation exposure during a long distant flight is low compared to the average annual exposure dosage, but the risk of thrombosis is increased. Altitudes up to 2,500 m pose no problem. Sufficient time to acclimatize must be taken when travelling to high altitudes and exercise kept to a minimum. Scuba diving is contraindicated. Since only a few drugs are completely safe during pregnancy a thorough risk/benefit evaluation is mandatory. Treatment of infections can be considerably complicated, but any necessary treatment should not be withheld because of the fear of potential fetal injury. Good knowledge of local medical resources is essential before travelling. Several personal protective measures minimize the risk of infection: food and water precautions, protection from insect bites and avoidance of crowds, unsafe sex and, if need be, freshwater. Many vaccinations are recommended for travellers. However, live vaccines are contraindicated in pregnant women because of theoretical considerations. Exceptionally a yellow fever vaccination may be given after the first trimester. Killed, inactivated or polysaccharide vaccines can be given after the first trimester after a thorough risk/benefit evaluation. Because of the potentially devastating effect of malaria to the mother and the child, travelling to endemic malaria regions should be avoided. If the risk of infection is high chemoprophylaxis with mefloquine is indicated. In low

  17. Speed management : enforcement and new technologies.

    NARCIS (Netherlands)

    Wegman, F.C.M. & Goldenbeld, C.

    2006-01-01

    Due to the massive character of speeding and inappropriate travel speeds, speed management continues to be an important and challenging policy area. Estimates are that in about a quarter to one third of fatal crashes excessive speeds are involved, making speed one of the crucial factors in road safe

  18. Calculating Speed of Sound

    Science.gov (United States)

    Bhatnagar, Shalabh

    2017-01-01

    Sound is an emerging source of renewable energy but it has some limitations. The main limitation is, the amount of energy that can be extracted from sound is very less and that is because of the velocity of the sound. The velocity of sound changes as per medium. If we could increase the velocity of the sound in a medium we would be probably able to extract more amount of energy from sound and will be able to transfer it at a higher rate. To increase the velocity of sound we should know the speed of sound. If we go by the theory of classic mechanics speed is the distance travelled by a particle divided by time whereas velocity is the displacement of particle divided by time. The speed of sound in dry air at 20 °C (68 °F) is considered to be 343.2 meters per second and it won't be wrong in saying that 342.2 meters is the velocity of sound not the speed as it's the displacement of the sound not the total distance sound wave covered. Sound travels in the form of mechanical wave, so while calculating the speed of sound the whole path of wave should be considered not just the distance traveled by sound. In this paper I would like to focus on calculating the actual speed of sound wave which can help us to extract more energy and make sound travel with faster velocity.

  19. Scouting the spectrum for interstellar travellers

    CERN Document Server

    Garcia-Escartin, Juan Carlos

    2012-01-01

    Advanced civilizations capable of interstellar travel, if they exist, are likely to have advanced propulsion methods. Spaceships moving at high speeds would leave a particular signature which could be detected from Earth. We propose a search based on the properties of light reflecting from objects travelling at relativistic speeds. Based on the same principles, we also propose a simple interstellar beacon with a solar sail.

  20. Travel during Pregnancy

    Science.gov (United States)

    ... Events Advocacy For Patients About ACOG Travel During Pregnancy Home For Patients Search FAQs Travel During Pregnancy ... Pregnancy FAQ055, February 2016 PDF Format Travel During Pregnancy Pregnancy When is the best time to travel ...

  1. Accurate estimation of indoor travel times

    DEFF Research Database (Denmark)

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

    2014-01-01

    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. In...... are collected within the building complex. Results indicate that InTraTime is superior with respect to metrics such as deployment cost, maintenance cost and estimation accuracy, yielding an average deviation from actual travel times of 11.7 %. This accuracy was achieved despite using a minimal-effort setup...

  2. 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.

  3. 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.

  4. Estimation Models for Average Speed of Traffic Flow Based on GPS Data of Taxi%基于出租车GPS数据的路段平均速度估计模型

    Institute of Scientific and Technical Information of China (English)

    姜桂艳; 常安德; 李琦; 伊峰

    2011-01-01

    The existing average speed estimation models based on GPS ( global positioning system) data of taxis are not applicable where high precision and low cost are of necessities. Two traditional models, namely a time integral model and a time interpolation model, based on the GPS data of taxis were modified, and the two modified models were combined to form a hybrid model. The three new models were verified using GPS data of taxis obtained from a part of road network of a large city. The results shown that the estimating precisions of the two modified models increased by 1. 5% and 19.7% , respectively, compared with the original time integral model and time interpolation model, and those of the hybrid model by 2. 8% and 8. 8% , respectively, compared with the two modified models.%为了解决现有基于GPS数据的路段平均速度估计模型应用条件苛刻、难以满足低成本和高精度信息需求问题,考虑不同类型GPS车辆运行特征,设计了两个基于出租车GPS数据估计路段平均速度的改进模型.基于两个改进模型,设计了路段平均速度的融合估计方法.用某城市局部路网的出租车GPS数据验证两个改进模型,并与传统模型进行了对比分析.结果表明,在不增加成本的条件下,两个改进模型的估计精度分别比传统模型提高了1.5%与19.7%;融合估计方法的精度比两个改进模型分别提高了2.8%与8.8%.

  5. Changing speed-VMT distributions: the effects on emissions inventories and conformity.

    Science.gov (United States)

    Nanzetta, K; Niemeier, D; Utts, J M

    2000-03-01

    The emissions factor modeling component of the motor vehicle emissions inventory (MVEI) modeling suite is currently being revised by the California Air Resources Board (CARB). One of the proposed changes in modeling philosophy is a shift from using link-based travel activity data to trip-based travel data for preparing mobile emissions inventories. Also as part of the revisions, new speed correction factors (SCFs) will be developed by CARB for the revised model. The new SCFs will be derived from vehicle emissions on 15 new driving cycles, each constructed to represent a typical trip at a specific average speed. This paper discusses how the new SCFs will affect transportation conformity and emissions inventory development, and evaluates the differences in total emissions produced by trip-based and link-based distributions of speed and vehicle miles of travel (VMT). We simulated both link-based and trip-based speed-VMT distributions using travel data from the Sacramento and San Diego travel demand models. On the basis of the simulation results, there is reason to expect that mobile emissions inventories constructed using the proposed trip-based philosophy will differ markedly from those constructed in the current manner. Noting that results may vary by region, increases are expected in the CO and HC inventory levels, with concomitant decreases in the NOx mobile emissions inventories.

  6. Travel/Travelers and Parasitic Diseases

    Science.gov (United States)

    ... care providers. Health departments, the travel industry, multinational corporations, missionary and volunteer organizations, and travelers can also ... PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel file ...

  7. 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...

  8. Bus Operation Monitoring Oriented Public Transit Travel Index System and Calculation Models

    Directory of Open Access Journals (Sweden)

    Jiancheng Weng

    2013-01-01

    Full Text Available This study proposed a two-dimensional index system which is concerned essentially with urban travel based on travel modes and user satisfaction. First, the public transit was taken as an example to describe the index system establishing process. In consideration of convenience, rapid, reliability, comfort, and safety, a bus service evaluation index system was established. The indicators include the N-minute coverage of bus stops, average travel speed, and fluctuation of travel time between stops and bus load factor which could intuitively describe the characteristics of public transport selected to calculate bus travel indexes. Then, combined with the basic indicators, the calculation models of Convenience Index (CI, Rapid Index (RI, Reliability Index (RBI, and Comfort Index (CTI were established based on the multisource data of public transit including the real-time bus GPS data and passenger IC card data. Finally, a case study of Beijing bus operation evaluation and analysis was conducted by taking real bus operation data including GPS data and passenger transaction recorder (IC card data. The results showed that the operation condition of the public transit was well reflected and scientifically classified by the bus travel index models.

  9. Development of control strategy of variable speed limits for improving traffic operations at freeway bottlenecks

    Institute of Scientific and Technical Information of China (English)

    李志斌; 刘攀; 王炜; 徐铖铖

    2014-01-01

    A control strategy of variable speed limits (VSL) was developed to reduce the travel time at freeway recurrent bottleneck areas. The proposed control strategy particularly focused on preventing the capacity drop and increasing the discharge flow. A cell transmission model (CTM) was developed to evaluate the effects of the proposed VSL control strategy on the traffic operations. The results show that the total travel time is reduced by 25.5% and the delay is reduced by 56.1%. The average travel speed is increased by 34.3% and the queue length is reduced by 31.0%. The traffic operation is improved by the proposed VSL control strategy. The way to use the proposed VSL control strategy in different types of freeway bottlenecks was also discussed by considering different traffic flow characteristics. It is concluded that the VSL control strategy is effective for merge bottlenecks but is less effective for diverge bottlenecks.

  10. Home range and travels

    Science.gov (United States)

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

    1968-01-01

    . Peromyscus generally used and maintained several or many different home sites and refuges in various parts of their home ranges, and frequently shifted about so that their principal activities centered on different sets of holes at different times. Once established, many Peromyscus remained in the same general area for a long time, perhaps for the duration of their lives. Extent of their travels in different directions and intensity of use of different portions of their home ranges varied within a general area in response to habitat changes, loss of neighbors, or other factors. Various authors have obtained both direct and indirect evidence of territoriality, in some degree, among certain species of Peromyscus. Young mice dispersed from their birth sites to establish home ranges of their own. Adults also sometimes left their home areas; some re-established elsewhere; others returned after exploratory travels. Most populations contained a certain proportion of transients; these may have been wanderers or individuals exploring out from established home ranges or seeking new ones. When areas were depopulated by removal trapping, other Peromyscus invaded. Invasion rates generally followed seasonal trends of reproduction and population density. Peromyscus removed from their home areas and released elsewhere returned home from various distances, but fewer returned from greater distances than from nearby; speed of return increased with successive trials. The consensus from present evidence is that ho-ming is made possible by a combination of random wandering and familiarity with a larger area than the day-to-day range. Records of juvenile wanderings during the dispersal phase and of adult explorations very nearly encompassed the distances over which any substantial amount of successful homing occurred. Methods of measuring sizes of home ranges and the limitations of these measurements were discussed in brief synopsis. It was co

  11. Travel time and travel cost in European air travel

    OpenAIRE

    Dusek, Tamas

    2012-01-01

    The aim of the study is to examine two issues of consumer air travel accessibility in Europe, namely flight time and ticket costs. The first part of the paper discusses the various methodological problems of creating time matrix and cost matrix of air travel. Because of problems of conceptualizing of the air travel network and the modifiable areal unit problem the analysis is conducted on several spatial levels. The smallest network consists of 15 busiest airports and the largest network has ...

  12. INTEGRATED SPEED ESTIMATION MODEL FOR MULTILANE EXPREESSWAYS

    Science.gov (United States)

    Hong, Sungjoon; Oguchi, Takashi

    In this paper, an integrated speed-estimation model is developed based on empirical analyses for the basic sections of intercity multilane expressway un der the uncongested condition. This model enables a speed estimation for each lane at any site under arb itrary highway-alignment, traffic (traffic flow and truck percentage), and rainfall conditions. By combin ing this model and a lane-use model which estimates traffic distribution on the lanes by each vehicle type, it is also possible to es timate an average speed across all the lanes of one direction from a traffic demand by vehicle type under specific highway-alignment and rainfall conditions. This model is exp ected to be a tool for the evaluation of traffic performance for expressways when the performance me asure is travel speed, which is necessary for Performance-Oriented Highway Planning and Design. Regarding the highway-alignment condition, two new estimators, called effective horizo ntal curvature and effective vertical grade, are proposed in this paper which take into account the influence of upstream and downstream alignment conditions. They are applied to the speed-estimation model, and it shows increased accuracy of the estimation.

  13. Childhood and Travel Literature.

    Science.gov (United States)

    Espey, David

    If children are not present in most travel literature--precisely because the genre has most typically been the domain of solitary male travelers who are escaping domestic obligation, routine, the familiar, and the family--they nevertheless are an integral part of the genre. The traveler is in many ways a child, an innocent abroad. Traveler writers…

  14. Travel-related illness.

    Science.gov (United States)

    Ziegler, Carol C

    2013-06-01

    Travel abroad for business and pleasure should be safe and meaningful for the traveler. To assure that safe experience, certain processes should be considered before travel. A thorough pretravel health assessment will offer patients and health care providers valuable information for anticipatory guidance before travel. The destination-based risk assessment will help determine the risks involved in travel to specific locations and guide in the development of contingency plans for all travelers, especially those with chronic conditions. Diseases are more prevalent overseas, and immunizations and vaccinations are all important considerations for persons traveling abroad.

  15. Rabies in travelers.

    Science.gov (United States)

    Gautret, Philippe; Parola, Philippe

    2014-03-01

    Most cases of rabies in travelers are associated with dog bites and occur in adults who are commonly migrants. The incidence of injuries to travelers caused by potentially rabid animals is approximately 0.4 % per month of stay. Dogs account for 51 % of cases, but nonhuman primates are the leading animals responsible for injuries in travelers returning from Southeast Asia. Travel to Southeast Asia, India and North Africa, young age, and traveling for tourism are risk factors for potential exposure. More than 70 % of travelers are not immunized prior to departing and do not receive adequate care when injured. The intradermal vaccination route has been proven economical, safe and immunogenic in travelers. The immunity provided by the three-dose series is long-lasting and should be considered an investment for future travel. Abbreviated schedules may be used for last-minute travelers.

  16. Why Does Light Have a Finite Speed?

    Science.gov (United States)

    Brusca, Stephen

    1985-01-01

    Examines the question "Why does light travel at speed c?", dispelling the widespread qualitative notion that the speed of light results from time delays in the interaction of electric and magnetic fields. Also presents information by which readers can work on their own qualitative insights concerning the speed of light. (JN)

  17. Effect of travel speed and suction carried by a pneumatic planter on seed dosage and germination Efecto de la velocidad de avance y de la succión de una sembradora neumática en la dosificación y germinación de semillas

    Directory of Open Access Journals (Sweden)

    Herrera G Óscar A.

    2006-09-01

    Full Text Available

    The effect of the travel speed and suction carried by the John Deere 7300 pneumatic planterʼs vacuum pump on ICA-305 corn, FUNKʼS HW-1758 sorghum, and Soyica P-34 soybean seeds dosage, germination, and vigor was studied; five travel speeds were assessed (2, 4, 6, 8 and 10 km/h and two vacuum pump work pressures (-1241.4 and -1738.0 Pa, at the sprocket combination 16/28. Seed weight (g supplied and seed of variance distribution in two lineal meters, seed feasibility by germination and vigor tests, were determined. Analysis of variance for means of the variable and four regression models (linear, quadratic, cubic and quadruple were applied. The linear regression model selected to explain correlation lead to conclude that travel speed of plant equipment do not affect seed dosage at two working pressures. No effect was found of planting work pressure on seed dosage. No effect was found of planting work pressure and travel speed on corn, sorghum, and soybean seed germination and germinated plantules vigor.

    Key words: corn, sorghum and soybean planting; pneumatic planter; planting travel speed; planting work pressure; seeds dosage and germination.

    Se estudió el efecto en maíz (ICA-305, sorgo (FUNKʼS HW-1758 y soya (Soyica P-34, de cinco (5 velocidades de marcha (2, 4, 6, 8 y 10 km/h y dos presiones de trabajo de la bomba de vacío (-1241.4 y -1738.0 Pa; en la relación de piñones 16/28 de la caja de cambios de la sembradora neumática John Deere 7300. Se determinó el peso dosificado y la distribución de la semilla en dos metros lineales; la viabilidad mediante pruebas de germinación y el vigor de plántulas germinadas. Se empleó análisis de varianza para las medias de las variables y se probaron cuatro modelos de regresión (lineal, cuadrático, cúbico y cuártico. En el modelo de regresión lineal elegido

  18. Zika Travel Information

    Science.gov (United States)

    ... Partners GeoSentinel Global TravEpiNet Mobile Apps RSS Feeds Zika Travel Information Recommend on Facebook Tweet Share Compartir ... website . World Map of Areas with Risk of Zika Zika Travel Notices Zika Virus in Cape Verde ...

  19. Travelling with HIV

    DEFF Research Database (Denmark)

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

    2013-01-01

    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...

  20. Travel Inside the Ear

    Science.gov (United States)

    ... Home » Health Info » Hearing, Ear Infections, and Deafness Travel Inside the Ear Video When sound waves reach ... are smaller than an orange seed. It then travels into the inner ear, which is filled with ...

  1. 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 ...

  2. 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...

  3. Phase Behavior and Implications for Travel time Observables (PHASE 2)

    Science.gov (United States)

    2015-09-30

    Phase behavior and implications for travel - time observables (PHASE-2) Emmanuel Skarsoulis Foundation for Research and Technology Hellas...perturbation behavior of travel time observables due to sound-speed perturbations. OBJECTIVES The objective is to study the behavior of the wave-theoretic...for this work came from the results of previous studies, supported by ONR, suggesting that the perturbation behavior of different travel - time

  4. Travel epidemiology. WHO perspective.

    Science.gov (United States)

    Gezairy, Hussein A

    2002-12-01

    International travel is undertaken by large, and ever increasing numbers of people for professional, social, recreational and humanitarian purposes, and this upward trend looks set to continue. Travelers are exposed to a variety of health risks of the unfamiliar environment of the visited area. The risk of exposure is determined by destination, duration of the visit, purpose of the visit, behavior of the traveler and underlying physical and biological status of the traveler. However, most risks can be minimized by suitable precautions taken before, during and after travel. Travelers can themselves, also, easily introduce any infectious agents they may harbor to the visited area. Many infectious diseases have been introduced in many parts of the world through travel and trade. Travel has been identified as a prime factor in the global spread of infectious diseases. In a world of rapid air travel, no country is safe from infectious diseases. An outbreak in one country can easily and rapidly be transmitted across long distances to affect other countries through travel and trade. The World Health Organization devotes great attention to prevention and control of global spread of infectious diseases and minimizing the negative effect of international travel on health. The main strategies of the World Health Organization for minimizing the negative effects of expanding travel on global health security include developing the necessary strategies, rules and regulations; strengthening global communicable diseases surveillance and response; dissemination of related information throughout the world and strengthening national capacity for communicable diseases surveillance and response.

  5. 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 tr

  6. Traveling and Asthma

    Science.gov (United States)

    ... Emergency Room? What Happens in the Operating Room? Traveling and Asthma KidsHealth > For Kids > Traveling and Asthma A A A What's in this ... t have to get in the way of travel fun. Let's find out how to be prepared ...

  7. Traveling Wave Solutions for Generalized Bretherton Equation

    Institute of Scientific and Technical Information of China (English)

    Amin Esfahani

    2011-01-01

    This paper studies the Generalized Bretherton equation using trigonometric function method including the sech-function method, the sine-cosine function method, and the tanh-function method, and He's semi-inverse method (He's variational method).Various traveling wave solutions are obtained, revealing an intrinsic relationship among the amplitude, frequency, and wave speed.

  8. Travelling Ideas, Power and Place

    DEFF Research Database (Denmark)

    Tait, Malcolm; Jensen, Ole B.

    2007-01-01

    propose a framework that focuses our understanding of how ideas are translated into new spatial settings.  The examples of the Urban Village and the Business Improvement District will be used to explicate the analytical framework.  In concluding, the paper assesses the utility of the analytic framework......A multitude of concepts and ideas have shaped practices in professions such as planning, urban design and urban management.  Now, however, the speed and intensity by which these ideas travel seems historically unprecedented. This paper explores how some of these ideas are formed and circulated...

  9. Comprehensive care of travelers.

    Science.gov (United States)

    Pust, R E; Peate, W F; Cordes, D H

    1986-12-01

    Travel, especially if it is international, often means major changes for the family. Family physicians should assess the epidemiologic risk and psychosocial significance of travel or relocation in light of the family's life-cycle stage and antecedent health. Using core references, which are kept current in partnership with public health agencies, family physicians are able to provide comprehensive immunization, medications, and patient education for all travel risks. Families are given medical record summaries and recommended sources of care at their destination. Eight weeks after their return patients are reassessed for newly acquired illness and helped to integrate the perspectives gained during the travel into the family's future dynamics. Taking advantage of growing travel medicine opportunities, family medicine educators should base the care of travelers and teaching of residents on defined competence priorities. Travelers' health provides a mutually rewarding model of shared care with public health consultants in the community medicine curriculum.

  10. Travelers, keep your yardsticks covered!

    CERN Document Server

    Fraundorf, P B

    1997-01-01

    This note is about introducing classical mechanics in a way that overtly dispels Newtonian misconceptions, minimizing the obstacles to a student's eventual understanding of space-time. This is done by operationally defining all quantities that depend on the observer's state of motion, including time, with respect to a specific ``map-frame'', and by introducing the classical equations for energy, momentum, and velocity-addition as low-speed approximations. It also provides tools for quantifying unidirectional motion at any speed, by students freshly-introduced to constant acceleration. This is done by describing traveler-time as the invariant in the metric equation, presented as a space-time extension of Pythagoras' theorem. Confusions involving frame-dependent simultaneity and length-contraction are minimized by considering only distances measured by observers in the reference map-frame.

  11. Numerical study on the restriction speed of train passing curved rail in cross wind

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The results of numerical investigations of aerodynamic forces and moment coefficients of flow passing a simplified train geometry under different wind speeds are summarized. To compute numerically the different coefficients, the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations, combined with the k-ε turbulence model, were solved using finite volume technique. The pres-sure-velocity fields were coupled using the SIMPLE algorithm. At each iteration the pressure correction was obtained by solving a velocity divergence-derived Poisson-like equation. With the computed aerodynamic forces, the formula of the restriction speed at which the train passed curved rail in cross wind was deduced to analyse the influences of aerodynamic forces on the restriction speed. Results of numerical investigations showed that aerodynamic lift and overturn moment increased more and more rapidly with train speed and wind speed. The enhancement trends showed nonlinear phenomena and enhanced risk in the course of train movement. When the train travels at a high speed and encounters a huge cross wind, the influence involved by nonlinear risk increment will extremely impair safety of train. The following conclusion can also be drawn: The effect of aerodynamic lift makes restriction speed reduce, however, the influences of aerodynamic drag to the limit train speed rest on the direction of wind flow. When the wind blows from inner rail to outer rail, aerodynamic forces shall reduce the restriction speed, by contraries, when the wind blows from outer rail to inner rail, aerodynamic forces shall increase the restriction speed.

  12. Numerical study on the restriction speed of train passing curved rail in cross wind

    Institute of Scientific and Technical Information of China (English)

    CHEN RuiLin; ZENG QingYuan; ZHONG XinGu; XIANG Jun; GUO XiaoGang; ZHAO Gang

    2009-01-01

    The results of numerical investigations of aerodynamic forces and moment coefficients of flow passing a simplified train geometry under different wind speeds are summarized. To compute numerically the different coefficients, the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) equations,combined with the k-ε turbulence model, were solved using finite volume technique. The pressure-velocity fields were coupled using the SIMPLE algorithm. At each iteration the pressure correction was obtained by solving a velocity divergence-derived Poisson-Iike equation. With the computed aerodynamic forces, the formula of the restriction speed at which the train passed curved rail in cross wind was deduced to analyse the influences of aerodynamic forces on the restriction speed. Results of numerical investigations showed that aerodynamic lift and overturn moment increased more and more rapidly with train speed and wind speed. The enhancement trends showed nonlinear phenomena and enhanced risk in the course of train movement. When the train travels at a high speed and encounters a huge cross wind, the influence involved by nonlinear risk increment will extremely impair safety of train.The following conclusion can also he drawn: The effect of aerodynamic lift makes restriction speed reduce, however, the influences of aerodynamic drag to the limit train speed rest on the direction of wind flow. When the wind blows from inner rail to outer rail, aerodynamic forces shall reduce the restriction speed, by contraries, when the wind blows from outer rail to inner rail, aerodynamic forces shall increase the restriction speed.

  13. 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...

  14. Histoplasmosis in Israeli travelers.

    Science.gov (United States)

    Segel, Michael J; Rozenman, Judith; Lindsley, Mark D; Lachish, Tamar; Berkman, Neville; Neuberger, Ami; Schwartz, Eli

    2015-06-01

    Histoplasmosis is a common endemic human mycoses acquired mostly in the Americas. We reviewed 23 cases of histoplasmosis in Israeli travelers; 22 had traveled to Central or South America and one to North America. Fourteen cases had been exposed to bat habitats and were symptomatic, presenting ≤ 3 months after their return. Asymptomatic patients (N = 9) were diagnosed during the evaluation of incidental radiological findings or because a travel partner had been suspected of Histoplasma infection, 16-120 months after their return. Serological testing was positive in 75% of symptomatic cases but only 22% of asymptomatic cases. Histoplasmosis should be considered in travelers returning from the Americas with respiratory or febrile illness within weeks of return, particularly if exposed to bat habitats. Travel history is essential in patients presenting with pulmonary nodules, even years after travel to endemic countries.

  15. 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...

  16. The Image of travelling

    DEFF Research Database (Denmark)

    Grand, Karina Lykke

    2016-01-01

    The Danish painter Martinus Rørbye was among of the Danish artists to reinvent the traditions of the genre of travel painting in the 1830s. His changes and developments of a new complex pictorial strategy were in many ways an answer to the changes in society, especially the advent of tourism....... The new travel image had its focus on concurrency, everyday life and the secular world, resulting in images that anticipated the photographic travel image, the snapshot and the travel postcard. The advent of this new strategy proved to have a very long after-life, as tourists and travellers of today still...... and experienced and how he interpreted this knowledge, visually and in words. Rørbye is my primary research focus, but his artistic struggles are very similar to other artists travelling in Italy at the time. I therefore use Martinus Rørbye’s Italian sojourn as a prism of interpretation....

  17. The stiffness variation of a micro-ring driven by a traveling piecewise-electrode.

    Science.gov (United States)

    Li, Yingjie; Yu, Tao; Hu, Yuh-Chung

    2014-09-16

    In the practice of electrostatically actuated micro devices; the electrostatic force is implemented by sequentially actuated piecewise-electrodes which result in a traveling distributed electrostatic force. However; such force was modeled as a traveling concentrated electrostatic force in literatures. This article; for the first time; presents an analytical study on the stiffness variation of microstructures driven by a traveling piecewise electrode. The analytical model is based on the theory of shallow shell and uniform electrical field. The traveling electrode not only applies electrostatic force on the circular-ring but also alters its dynamical characteristics via the negative electrostatic stiffness. It is known that; when a structure is subjected to a traveling constant force; its natural mode will be resonated as the traveling speed approaches certain critical speeds; and each natural mode refers to exactly one critical speed. However; for the case of a traveling electrostatic force; the number of critical speeds is more than that of the natural modes. This is due to the fact that the traveling electrostatic force makes the resonant frequencies of the forward and backward traveling waves of the circular-ring different. Furthermore; the resonance and stability can be independently controlled by the length of the traveling electrode; though the driving voltage and traveling speed of the electrostatic force alter the dynamics and stabilities of microstructures. This paper extends the fundamental insights into the electromechanical behavior of microstructures driven by electrostatic forces as well as the future development of MEMS/NEMS devices with electrostatic actuation and sensing.

  18. FORMS OF YOUTH TRAVEL

    OpenAIRE

    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...

  19. Using Optic Flow for the Estimation of Travel Distance

    Directory of Open Access Journals (Sweden)

    Markus Lappe

    2011-05-01

    Full Text Available Much research on optic flow has been concerned with the estimation of heading and the control of the direction of self-motion. In my presentation I will instead focus on a different use of optic flow, namely the estimation of the distance that one has traveled. Optic flow in itself does not provide travel distance, only the combination of distance and speed (time-to-contact is directly available. However, when scaling information from the environment is present, such as the distance to the ground when standing or walking on flat terrain, an integration of the optical velocity can yield ego-speed and travel distance. I will present experiments that show that humans can use optic flow for the estimation of travel distance, but that they often under- and, in some conditions, overestimate a movement's extent. I will then present a model of travel distance estimation from optic flow that is based on leaky path integration.

  20. Update on travelers' health.

    Science.gov (United States)

    Weber, Carol J

    2005-10-01

    As an international traveler, contact your health care provider at least 4 to 6 weeks before departure to obtain needed vaccinations and prophylactic medications. Be aware of the occurrence of any disease outbreaks in the countries you are visiting. While traveling, don't forget that one of the most important practices in preventing illness from infections is handwashing. Wash your hands carefully and frequently with soap and water, and if soap and water are not available use an alcohol-based hand rub. Be a responsible traveler by becoming informed about health risks and what to do to avoid them before you travel.

  1. Turbulent boundary-layer control with spanwise travelling waves

    Energy Technology Data Exchange (ETDEWEB)

    Whalley, Richard D; Choi, Kwing-So, E-mail: Richard.Whalley@nottingham.ac.uk, E-mail: Kwing-So.Choi@nottingham.ac.uk [Faculty of Engineering, University of Nottingham, Nottingham, NG7 2RD (United Kingdom)

    2011-12-22

    It has been demonstrated through numerical simulations using Lorentz forcing that spanwise travelling waves on turbulent wall flows can lead to a skin-friction drag reduction on the order of 30%. As an aeronautical application of this innovative flow control technique, we have investigated into the use of Dielectric-Barrier-Discharge (DBD) plasma actuators to generate spanwise travelling waves in air. The near-wall structures modified by the spanwise travelling waves were studied using the PIV technique in a wind tunnel, while the associated turbulence statistics were carefully documented using hot-wire anemometry. We observed the spreading of low-speed fluid by the spanwise travelling streamwise vortices, which seems to have greatly attenuated the turbulence production process. This is very much in line with the finding of DNS studies, where wide low-speed ribbons replaced the low-speed streaks.

  2. 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.

  3. Application of Hybrid Encoding Genetic Algorithm on Pickup and Delivery Traveling Salesman Problem with Traffic Conditions

    Directory of Open Access Journals (Sweden)

    S. Patvichaichod

    2011-01-01

    Full Text Available Problem statement: This study deals with the pickup and delivery traveling salesman problem with traffic conditions (PDTSPTW, an extension of the pickup and delivery traveling salesman problem (PDTSP where each customer to be served is associated with two quantities of product to be collected and delivered. Almost PDTSP problems uses distance between each point of customers as Euclidean Distance and are not concerned with other parameters to find minimal cost. Approach: The PDTSPTC concerns more parameters, such as street network and vehicle speed, which results it closer to the real world condition. The study also proposes the developed genetic algorithm called “Hybrid Encoding Genetic Algorithm (HEGA”. The concept is to combine binary encoding and integer encoding together, causing the in complexity of the algorithm structure and the ease of implementation. Results: the HEGA can save the travel cost about 26-57%. It is obviously seen that HEGA in the PDTSPTC test problems result the fast convergence that is about 12-43% and in all, the computational time is under 6 seconds. Conclusion: The HEGA performs quite well when testing a test problem. Computation times are small in all case. The PDTSPTC is closer to real-world conditions than PDTSP. This problem can be applied in logistics immediately if the distance of streets, traffic conditions (average vehicle speed in each street and vehicle conditions (fuel consumption rate and vehicle capacity are known.

  4. Accessibility, Congestion and Travel Delays in Dar es Salaam

    DEFF Research Database (Denmark)

    Melbye, Dea Christine; Møller-Jensen, Lasse; Andreasen, Manja Hoppe

    2015-01-01

    on to present a review of research into travel speed levels and congestion in Dar es Salaam. A set of city-wide maps of accessibility and delay levels are constructed based on available speed data and road network data obtained from the OpenStreetMap project and the findings are discussed with respect...

  5. Efeitos da velocidade e da direção do vento na uniformidade de aplicação de água de sistemas autopropelidos Effects of wind speed and direction on water application uniformity of traveler irrigation systems

    Directory of Open Access Journals (Sweden)

    Henrique F. E. de Oliveira

    2012-08-01

    quantitative analysis about the effects of wind velocity and direction on water application uniformity of traveler irrigation systems. Simulations indicated that as wind direction moves from perpendicular to parallel to the sprinkler travel axis, the deleterious effects of wind velocity are enhanced. Therefore, these results demonstrated that both wind direction and wind speed must be considered on towpath spacing recommendations.

  6. Traveling with children

    Science.gov (United States)

    ... let them inspect it. Small jars of baby food travel well. They make little waste and you can dispose of them easily. Air ... not eat raw fruits or vegetables. Eat only food that is hot and has been cooked ... and hotels for guidance and assistance. For foreign travel, check ...

  7. 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!

  8. 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...

  9. Information for travellers' physicians.

    Science.gov (United States)

    Allison, D J; Blinco, K

    1990-07-01

    Physicians can obtain advice about international travel for their patients from many different sources of information. The authors review some of the most common sources based on their experience at the International Travellers' Clinic operated by the New Brunswick Department of Health and Community Services in Fredericton. They identify readily available handbooks and periodicals and compare two computer software programs.

  10. Information for Travellers' Physicians

    OpenAIRE

    Allison, David J; Blinco, Kimberley

    1990-01-01

    Physicians can obtain advice about international travel for their patients from many different sources of information. The authors review some of the most common sources based on their experience at the International Travellers' Clinic operated by the New Brunswick Department of Health and Community Services in Fredericton. They identify readily available handbooks and periodicals and compare two computer software programs.

  11. Traveling and Asthma

    Science.gov (United States)

    ... What Happens in the Operating Room? Traveling and Asthma KidsHealth > For Kids > Traveling and Asthma A A A What's in this article? Pack ... Or how about sleepover camp? If you have asthma , you'll be packing more than your clothes ...

  12. Monitoring travel times in an urban network using video, GPS and Bluetooth

    OpenAIRE

    Jie, L.; van Zuylen, H.J.; Chunhua, L.; Shoufeng, L.

    2011-01-01

    The travel time is an important measure for the quality of traffic. This paper discusses a few methods to measure or estimate the travel time in urban road networks. First of all, it is important to know that urban travel times display a large variation, so that the measurement of a single (average) travel time is not so meaningful. The travel time distribution is more relevant than the single value of the average. This distribution can be obtained from observations of travel times of individ...

  13. Valuation of travel time savings for intercity travel: The Madrid-Barcelona corridor

    DEFF Research Database (Denmark)

    Roman, Concepcion; Carlos Martin, Juan; Espino, Raquel

    2014-01-01

    We derive values of travel time savings (VOT) for the Madrid-Barcelona corridor, linking the two largest cities in Spain, based on the estimation of discrete choice models among the main public transport services in the corridor: air transport, high speed rail (HSR) and bus. The new HSR alternative...... (which started to operate in February 2008) competes directly with one of the densest airline domestic markets in the world, and its introduction produced substantial improvements in level of service, achieving reductions in travel time of more than 50% over the conventional train. A specifically...... to provide useful information to quantify users' benefits during the lifespan of a given project. We found, as expected, that HSR and air transport users exhibit substantially higher values for saving travel time than bus travellers. Also as expected, savings of waiting time are more valued than savings...

  14. Capacitated Vehicle Routing with Nonuniform Speeds

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath;

    2016-01-01

    is the distance traveled divided by its speed.Our algorithm relies on a new approximate minimum spanning tree construction called Level-Prim, which is related to but different from Light Approximate Shortest-path Trees. We also extend the widely used tour-splitting technique to nonuniform speeds, using ideas from...... the 2-approximation algorithm for scheduling in unrelated machines....

  15. Comparison Of Travel Behaviour In 11 European Countries By Use Of Post- Harmonized European National Travel Surveys

    DEFF Research Database (Denmark)

    Christensen, Linda; Hubert, Jean-Paul; Järvi, Tuuli;

    2014-01-01

    of this paper is to compare travel behaviour among 11 European counties using NTS’s. A post-harmonization process is developed to overcome methodological differences between the surveys and to isolate the differences in travel behaviour. Travel behaviour is measured as mileage, time use, and trips per trip......Travel behaviour comparison among countries has become interesting to understand structural differences in travel behaviour between countries which are important to help developing more sustainable transport policies. To that end, National Travel Surveys (NTS’s) are the most suitable tool. The aim......-maker by mode and differences between countries as a function of travel distance, purpose, license holding, and family type are presented. The results demonstrate that the number of trips per responding trip-maker on an average day are very similar over the countries whereas mileage differs most, from 33 km...

  16. Valuation of travel time for international long-distance travel - results from the Fehmarn Belt stated choice experiment

    DEFF Research Database (Denmark)

    Mabit, Stefan Lindhard; Rich, Jeppe; Burge, Peter

    2013-01-01

    of travel time savings (VTTS). The final model, which was formulated as a nested logit model and included Box–Cox transformed travel time and cost attributes, revealed several interesting findings. Firstly, we found damping effects in both cost and time – most strongly in cost. Secondly, we found...... significant interactions among travel cost and time, and journey characteristics, such as distance and duration. This had direct impact on the VTTS, which was shown to decrease with distance and duration. Thirdly, we found that air travel implies a higher average VTTS, which is to be expected but rarely......The geographical scope of travel varies from short distances in urban areas to long distances across cities and countries. While urban travel has been widely analysed in the literature, travel over longer distances and particularly across countries, has received much less attention. While this may...

  17. Epidemiology of traveler's diarrhea.

    Science.gov (United States)

    Castelli, F; Carosi, G

    1995-01-01

    Annually, over 75 million international passengers travel to tropical areas, more than 20 million of whom come from industrialized countries. They experience a high rate of traveler's diarrhea (TD), varying from 20 to 56%, which may result in serious limitations to their activities. The cause of TD is considered to be infectious in the overwhelming majority of cases and, apart from differences in relative importance, the list of responsible microbial agents is fairly constant regardless of geographic origin. The ingestion of contaminated food or water is considered to be the principal mode of transmission of the enteric pathogens of TD. Several factors have been proposed as playing a role in the etiogenesis of diarrhea in travelers, including personal (age, socioeconomic status, body weight, preexisting gastrointestinal illnesses), behavioral (mode of travel, standard of accommodation, eating in public places, dietary errors) and travel-related (destination, duration of stay, country of origin, season) factors, which are reviewed in detail.

  18. Season and Weather Effects on Travel-Related Mood and Travel Satisfaction

    Science.gov (United States)

    Ettema, Dick; Friman, Margareta; Olsson, Lars E.; Gärling, Tommy

    2017-01-01

    This study examines the effects of season and weather on mood (valence and activation) and travel satisfaction (measured by the Satisfaction with Travel Scale). Analyses are presented of 562 time-sampled morning commutes to work made by 363 randomly sampled people in three different Swedish cities asking them to use smartphones to report their mood in their home before and directly after the commutes. These reports as well as satisfaction with the commute obtained in summer and winter are linked to weather data and analyzed by means of fixed-effects regression analyses. The results reveal main effects of weather (temperature and precipitation) on mood and travel satisfaction (temperature, sunshine, precipitation, and wind speed). The effects of weather on mood and travel satisfaction differ depending on travel mode. Temperature leads to a more positive mood, wind leads to higher activation for public transport users, and sunshine leads to a more negative mood for cyclists and pedestrians. Sunshine and higher temperatures make travel more relaxed although not for cycling and walking, and rain and snow lead to a higher cognitive assessed quality of travel. PMID:28220100

  19. Aggregation and Averaging.

    Science.gov (United States)

    Siegel, Irving H.

    The arithmetic processes of aggregation and averaging are basic to quantitative investigations of employment, unemployment, and related concepts. In explaining these concepts, this report stresses need for accuracy and consistency in measurements, and describes tools for analyzing alternative measures. (BH)

  20. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    1999-01-01

    In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...... approximations to the Riemannian metric, and that the subsequent corrections are inherient in the least squares estimation. Keywords: averaging rotations, Riemannian metric, matrix, quaternion...

  1. Monitoring speed before and during a speed publicity campaign.

    Science.gov (United States)

    van Schagen, Ingrid; Commandeur, Jacques J F; Goldenbeld, Charles; Stipdonk, Henk

    2016-12-01

    Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road-side radars, mounted in light poles, were used and registered the speeds on 20 locations in built-up areas. Speeds of over 10 million vehicles were measured. Ten locations had a posted speed limit of 50km/h; the other ten had a posted speed limit of 30km/h. Posters were placed at half of each group of locations to remind drivers of the speed limit. The average speed on the 50km/h roads was 46.2km/h, and 36.1km/h on the 30km/h roads. The average proportions of vehicles exceeding the speed limit were 33.3% and 70.1% respectively. For the 30km/h roads, the data shows differences in speed and speeding behaviour between the six distinguished observation periods, but overall these differences cannot be logically linked to the contents of the phases and, hence, cannot be explained as an effect of the campaign. The only exception was an effect of local speed limit reminders on the 30km/h roads. This effect, however, was temporary and had disappeared within a week.

  2. 基于电压调节的行波超声波电机转速模糊PID控制%Fuzzy PID Speed Control of Traveling Wave Ultrasonic Motor Using Voltage Amplitude Regulation

    Institute of Scientific and Technical Information of China (English)

    史敬灼; 张慧敏

    2011-01-01

    Accordance with ultrasonic motor's time-variable nonlinearity, a online adaptive correction based on fuzzy logic was presented. The special nature of ultrasonic motor's speed control were fully taken into account in designing fuzzy rules. The amplitude of driving voltage was used as the control parameter to realite the control method. The experiments indicate that the control characteristics are much better than that of PID controller.%针对超声波电机的时变非线性,给出了基于模糊逻辑的PID控制参数在线自适应校正方法.模糊规则设计中充分考虑了超声波电机转速控制的特殊性.采用驱动电压幅值作为控制量,实现了该控制方法.实验表明,控制性能优于PID控制器.

  3. Travelling waves in hybrid chemotaxis models

    CERN Document Server

    Franz, Benjamin; Painter, Kevin J; Erban, Radek

    2013-01-01

    Hybrid models of chemotaxis combine agent-based models of cells with partial differential equation models of extracellular chemical signals. In this paper, travelling wave properties of hybrid models of bacterial chemotaxis are investigated. Bacteria are modelled using an agent-based (individual-based) approach with internal dynamics describing signal transduction. In addition to the chemotactic behaviour of the bacteria, the individual-based model also includes cell proliferation and death. Cells consume the extracellular nutrient field (chemoattractant) which is modelled using a partial differential equation. Mesoscopic and macroscopic equations representing the behaviour of the hybrid model are derived and the existence of travelling wave solutions for these models is established. It is shown that cell proliferation is necessary for the existence of non-transient (stationary) travelling waves in hybrid models. Additionally, a numerical comparison between the wave speeds of the continuum models and the hybr...

  4. Average Bandwidth Allocation Model of WFQ

    Directory of Open Access Journals (Sweden)

    Tomáš Balogh

    2012-01-01

    Full Text Available We present a new iterative method for the calculation of average bandwidth assignment to traffic flows using a WFQ scheduler in IP based NGN networks. The bandwidth assignment calculation is based on the link speed, assigned weights, arrival rate, and average packet length or input rate of the traffic flows. We prove the model outcome with examples and simulation results using NS2 simulator.

  5. [Thromboembolism in travelers].

    Science.gov (United States)

    Bihari, I; Sándor, T

    2001-11-11

    The association between long haul travel and the risk of venous thromboembolism are suspected for long time. Mostly air travel related thrombosis series have been reported in the literature. Risk factors can be classified as: 1. travel related factors (coach position, immobilization, prolonged air travel, narrow seat and room, diuretic effect of alcohol, insufficient fluid intake, dehydration, direct pressure on leg veins, rare inspiration). 2. air plane related risk factors (low humidity, relative hypoxia, stress). 3. patient related factors (hereditary and acquired thrombophylia, previous deep venous thrombosis, age over 40, recent surgery or trauma, gravidity, puerperium, oestrogen containing pills, varicosity, chronic heart disease, obesity, fever, diarrhoea, vomiting, smoking). No patient related factors were found in some cases. To reduce the hazards air travellers are rightly concerned to know the level of the risk and the airlines should be responsible for this information. People should discuss with their physician what prophlylactic measures should be taken, such as compression stockings or low molecular weight heparin. Not only flight but car, bus and train travellers are also at risk of developing venous thromboembolism. Long haul travel alone is a separate risk factor for venous thromboembolism.

  6. Understanding taxi travel patterns

    Science.gov (United States)

    Cai, Hua; Zhan, Xiaowei; Zhu, Ji; Jia, Xiaoping; Chiu, Anthony S. F.; Xu, Ming

    2016-09-01

    Taxis play important roles in modern urban transportation systems, especially in mega cities. While providing necessary amenities, taxis also significantly contribute to traffic congestion, urban energy consumption, and air pollution. Understanding the travel patterns of taxis is thus important for addressing many urban sustainability challenges. Previous research has primarily focused on examining the statistical properties of passenger trips, which include only taxi trips occupied with passengers. However, unoccupied trips are also important for urban sustainability issues because they represent potential opportunities to improve the efficiency of the transportation system. Therefore, we need to understand the travel patterns of taxis as an integrated system, instead of focusing only on the occupied trips. In this study we examine GPS trajectory data of 11,880 taxis in Beijing, China for a period of three weeks. Our results show that taxi travel patterns share similar traits with travel patterns of individuals but also exhibit differences. Trip displacement distribution of taxi travels is statistically greater than the exponential distribution and smaller than the truncated power-law distribution. The distribution of short trips (less than 30 miles) can be best fitted with power-law while long trips follow exponential decay. We use radius of gyration to characterize individual taxi's travel distance and find that it does not follow a truncated power-law as observed in previous studies. Spatial and temporal regularities exist in taxi travels. However, with increasing spatial coverage, taxi trips can exhibit dual high probability density centers.

  7. [Traveling with immunosuppression].

    Science.gov (United States)

    Birkenfeld, G

    2014-03-01

    The rapidly increasing number of patients with immunosuppression is followed by their expectation to lead-as much as possible-a "normal" life, including long-distance travel. The advice and preventive measures for diseases associated with travelling depend overall on the mode of the patient's immunosuppression. This report explains the individual preventive possibilities, limits and risks for travellers with asplenia, common variable immunodeficiency, chronic inflammatory bowel and rheumatic diseases, HIV, as well as for patients having undergone solid organ or bone marrow transplantation or chemotherapy.

  8. Your Average Nigga

    Science.gov (United States)

    Young, Vershawn Ashanti

    2004-01-01

    "Your Average Nigga" contends that just as exaggerating the differences between black and white language leaves some black speakers, especially those from the ghetto, at an impasse, so exaggerating and reifying the differences between the races leaves blacks in the impossible position of either having to try to be white or forever struggling to…

  9. On Averaging Rotations

    DEFF Research Database (Denmark)

    Gramkow, Claus

    2001-01-01

    In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

  10. 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

  11. Travel Inside the Ear

    Medline Plus

    Full Text Available ... stirrup. These are the smallest bones in your body. Together they are smaller than an orange seed. It then travels into the inner ear, which ... organizations Related Topics ...

  12. Travelers' Health: Leishmaniasis, Cutaneous

    Science.gov (United States)

    ... Water Disinfection Infographics for Travelers MERS Health Advisory poster Food and Water: What's Safer Health Advisory: MERS ... noise, they are small (approximately one-third the size of mosquitoes), and their bites might not be ...

  13. Travelers' Health: Rabies

    Science.gov (United States)

    ... Water Disinfection Infographics for Travelers MERS Health Advisory poster Food and Water: What's Safer Health Advisory: MERS ... weight may be small in relation to the size and number of wounds. RIG is difficult to ...

  14. Traveling-wave photodetector

    Science.gov (United States)

    Hietala, Vincent M.; Vawter, Gregory A.

    1993-01-01

    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.

  15. Malaria and Travelers

    Science.gov (United States)

    ... a CDC Malaria Branch clinician. malaria@cdc.gov Malaria and Travelers Recommend on Facebook Tweet Share Compartir ... may be at risk for infection. Determine if malaria transmission occurs at the destinations Obtain a detailed ...

  16. Travel Inside the Ear

    Medline Plus

    Full Text Available ... Info » Hearing, Ear Infections, and Deafness Travel Inside the Ear Video When sound waves reach your ear, ... heard a soft sound or a loud sound. The sound passes through the outer ear and is ...

  17. Why They Travel Alone?

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    "WHY Chinese Women Travel Alone" was the theme of a special edition of "Truth Talk" a popular talk show on China Central Television (CCTV), which focused on a few middle-aged women from different cultural backgrounds, social classes, and various educational backgrounds who had all branched out on their own for one reason or another. Each woman spoke of her experiences and feelings while travelling alone. They were all

  18. Freedom of Movement (Common Travel Area) (Travel Documentation) Bill 2014

    DEFF Research Database (Denmark)

    Butler, Graham; Hunt, Brian; Flanagan, Terence

    2014-01-01

    Private Members' Bill (legislation) introduced in Dáil Éireann (House of Deputies), Houses of the Oireachtas (Irish Parliament). An Act to reinforce the Common Travel Area by providing for passport-free travel for persons who are entitled to travel within the Common Travel Area without a passport...

  19. Average-passage flow model development

    Science.gov (United States)

    Adamczyk, John J.; Celestina, Mark L.; Beach, Tim A.; Kirtley, Kevin; Barnett, Mark

    1989-01-01

    A 3-D model was developed for simulating multistage turbomachinery flows using supercomputers. This average passage flow model described the time averaged flow field within a typical passage of a bladed wheel within a multistage configuration. To date, a number of inviscid simulations were executed to assess the resolution capabilities of the model. Recently, the viscous terms associated with the average passage model were incorporated into the inviscid computer code along with an algebraic turbulence model. A simulation of a stage-and-one-half, low speed turbine was executed. The results of this simulation, including a comparison with experimental data, is discussed.

  20. Contribution of ultrasonic traveling wave to chemical-mechanical polishing.

    Science.gov (United States)

    Li, Liang; He, Qing; Zheng, Mian; Liu, Zheng

    2015-02-01

    The ultrasonic vibrators are introduced into the chemical-mechanical polishing devices, and in this polishing system, the ultrasonic vibrators generate ultrasonic traveling wave and keep coaxial with the polished silicon wafer rotating at given speed so as to compare the texture of the polished silicon wafers. And the experiments on the chemical-mechanical polishing with assisted ultrasonic vibration are accomplished in order to investigate the effect of the ultrasonic vibration on the chemical-mechanical polishing. Via comparing the roughness average of the two silicon wafers polished with assisted ultrasonic vibration and without assisted vibration, it is found that the morphology of the silicon wafer polished with assisted vibration is superior to that without assisted vibration, that is, this series of experiments indicate that the ultrasonic vibration is beneficial to the chemical-mechanical polishing. Aiming at understanding the contribution of the ultrasonic vibration to chemical-mechanical polishing in detail, the model of the chemical-mechanical polishing with the assisted ultrasonic vibration is built up, which establishes the relationship of the removal rate and the polishing variables such as the rotary speed of silicon wafers, the amplitude and the frequency of vibrators, the particle density of polishing slurry and the characteristics of polishing pad etc. This model not only could be used to explain the experimental results but also to illuminate the roles played by the polishing variables.

  1. Destination therapy: safety and feasibility of national and international travel.

    Science.gov (United States)

    Coyle, Laura A; Martin, Michele M; Kurien, Sudha; Graham, Joel D; Gallagher, Colleen; Silver, Marc A; Slaughter, Mark S

    2008-01-01

    Results for Destination Therapy (DT) continue to improve with advanced technology, better patient selection, and experienced clinical management. Quality of life for these patients is an important component of the overall success of DT, and traveling is becoming more common. We reviewed our experience with long-distance travel in our DT population. All patients implanted with a left ventricular assist device for DT were followed prospectively. Long-distance travel was considered to be >200 miles, one way from their homes. There were 15 patients (14 men) with an average age of 66 years (range, 30-82) who traveled a combined total of 40 long-distance trips. Four trips were international (Spain, Canada (2), and Puerto Rico), 35 within the continental U.S., and one to Hawaii. The average one way distance traveled was 925 miles with a range of 218-4256 miles. The average time away from home was 8.3 days (range, 2-30). Patients traveled by airplane (17), car (23), and one trip included a 5 day cruise. Five complications occurred: driveline trauma, delay of reentry into the United States, missed flight, red heart alarm from bearing wear, and dehydration. All patients returned home safely for routine follow-up. Long-distance travel is possible for DT patients. Anticipating potential problems and careful planning is necessary for safe national and international travel.

  2. High-Speed RaPToRS

    Science.gov (United States)

    Henchen, Robert; Esham, Benjamin; Becker, William; Pogozelski, Edward; Padalino, Stephen; Sangster, Thomas; Glebov, Vladimir

    2008-11-01

    The High-Speed Rapid Pneumatic Transport of Radioactive Samples (HS-RaPToRS) system, designed to quickly and safely move radioactive materials, was assembled and tested at the Mercury facility of the Naval Research Laboratory (NRL) in Washington D.C. A sample, which is placed inside a four-inch-diameter carrier, is activated before being transported through a PVC tube via airflow. The carrier travels from the reaction chamber to the end station where it pneumatically brakes prior to the gate. A magnetic latch releases the gate when the carrier arrives and comes to rest. The airflow, optical carrier-monitoring devices, and end gate are controlled manually or automatically with LabView software. The installation and testing of the RaPToRS system at NRL was successfully completed with transport times of less than 3 seconds. The speed of the carrier averaged 16 m/s. Prospective facilities for similar systems include the Laboratory for Laser Energetics and the National Ignition Facility.

  3. A crust and upper mantle model of Eurasia and North Africa for Pn travel time calculation

    Energy Technology Data Exchange (ETDEWEB)

    Myers, S; Begnaud, M; Ballard, S; Pasyanos, M; Phillips, W S; Ramirez, A; Antolik, M; Hutchenson, K; Dwyer, J; Rowe, C; Wagner, G

    2009-03-19

    We develop a Regional Seismic Travel Time (RSTT) model and methods to account for the first-order effect of the three-dimensional crust and upper mantle on travel times. The model parameterization is a global tessellation of nodes with a velocity profile at each node. Interpolation of the velocity profiles generates a 3-dimensional crust and laterally variable upper mantle velocity. The upper mantle velocity profile at each node is represented as a linear velocity gradient, which enables travel time computation in approximately 1 millisecond. This computational speed allows the model to be used in routine analyses in operational monitoring systems. We refine the model using a tomographic formulation that adjusts the average crustal velocity, mantle velocity at the Moho, and the mantle velocity gradient at each node. While the RSTT model is inherently global and our ultimate goal is to produce a model that provides accurate travel time predictions over the globe, our first RSTT tomography effort covers Eurasia and North Africa, where we have compiled a data set of approximately 600,000 Pn arrivals that provide path coverage over this vast area. Ten percent of the tomography data are randomly selected and set aside for testing purposes. Travel time residual variance for the validation data is reduced by 32%. Based on a geographically distributed set of validation events with epicenter accuracy of 5 km or better, epicenter error using 16 Pn arrivals is reduced by 46% from 17.3 km (ak135 model) to 9.3 km after tomography. Relative to the ak135 model, the median uncertainty ellipse area is reduced by 68% from 3070 km{sup 2} to 994 km{sup 2}, and the number of ellipses with area less than 1000 km{sup 2}, which is the area allowed for onsite inspection under the Comprehensive Nuclear Test Ban Treaty, is increased from 0% to 51%.

  4. On the treatment of airline travelers in mathematical models.

    Directory of Open Access Journals (Sweden)

    Michael A Johansson

    Full Text Available The global spread of infectious diseases is facilitated by the ability of infected humans to travel thousands of miles in short time spans, rapidly transporting pathogens to distant locations. Mathematical models of the actual and potential spread of specific pathogens can assist public health planning in the case of such an event. Models should generally be parsimonious, but must consider all potentially important components of the system to the greatest extent possible. We demonstrate and discuss important assumptions relative to the parameterization and structural treatment of airline travel in mathematical models. Among other findings, we show that the most common structural treatment of travelers leads to underestimation of the speed of spread and that connecting travel is critical to a realistic spread pattern. Models involving travelers can be improved significantly by relatively simple structural changes but also may require further attention to details of parameterization.

  5. Risk assessment in travel medicine.

    Science.gov (United States)

    Leggat, Peter A

    2006-01-01

    Risk assessment is an integral part of pre-travel and post- assessment. Risk assessment largely determines what health and safety advice and interventions are given within the relevant prevailing travel health guidelines. Risk assessment needs time and depends on information, including that given by the traveller. Risk assessment also needs to be documented. Risk assessment of the traveller preferably starts before they enter the consulting room, where travellers may complete a pre-travel health questionnaire. Armed with this information, risk assessment may be assisted by access to computerised travel health databases and the published literature. Experience of travel to the destination may also assist in risk assessment and the tour operator, overseas employer or agency, the traveller or even the travel health advisers themselves may provide this information.

  6. Monitoring travel times in an urban network using video, GPS and Bluetooth

    NARCIS (Netherlands)

    Jie, L.; Van Zuylen, H.J.; Chunhua, L.; Shoufeng, L.

    2011-01-01

    The travel time is an important measure for the quality of traffic. This paper discusses a few methods to measure or estimate the travel time in urban road networks. First of all, it is important to know that urban travel times display a large variation, so that the measurement of a single (average)

  7. On the Origin of Traveling Pulses in Bistable Systems

    CERN Document Server

    Elphick, C; Malomed, B A; Meron, E

    1997-01-01

    The interaction between a pair of Bloch fronts forming a traveling domain in a bistable medium is studied. A parameter range beyond the nonequilibrium Ising-Bloch bifurcation is found where traveling domains collapse. Only beyond a second threshold the repulsive front interactions become strong enough to balance attractive interactions and asymmetries in front speeds, and form stable traveling pulses. The analysis is carried out for the forced complex Ginzburg-Landau equation. Similar qualitative behavior is found in the bistable FitzHugh-Nagumo model.

  8. Faster than light motion does not imply time travel

    CERN Document Server

    Andréka, H; Németi, I; Stannett, M; Székely, G

    2014-01-01

    Seeing the many examples in the literature of causality violations based on faster-than- light (FTL) signals one naturally thinks that FTL motion leads inevitably to the possibility of time travel. We show that this logical inference is invalid by demonstrating a model, based on (3+1)-dimensional Minkowski spacetime, in which FTL motion is permitted (in every direction without any limitation on speed) yet which does not admit time travel. Moreover, the Principle of Relativity is true in this model in the sense that all observers are equivalent. In short, FTL motion does not imply time travel after all.

  9. Colored Traveling Salesman Problem.

    Science.gov (United States)

    Li, Jun; Zhou, MengChu; Sun, Qirui; Dai, Xianzhong; Yu, Xiaolong

    2015-11-01

    The multiple traveling salesman problem (MTSP) is an important combinatorial optimization problem. It has been widely and successfully applied to the practical cases in which multiple traveling individuals (salesmen) share the common workspace (city set). However, it cannot represent some application problems where multiple traveling individuals not only have their own exclusive tasks but also share a group of tasks with each other. This work proposes a new MTSP called colored traveling salesman problem (CTSP) for handling such cases. Two types of city groups are defined, i.e., each group of exclusive cities of a single color for a salesman to visit and a group of shared cities of multiple colors allowing all salesmen to visit. Evidences show that CTSP is NP-hard and a multidepot MTSP and multiple single traveling salesman problems are its special cases. We present a genetic algorithm (GA) with dual-chromosome coding for CTSP and analyze the corresponding solution space. Then, GA is improved by incorporating greedy, hill-climbing (HC), and simulated annealing (SA) operations to achieve better performance. By experiments, the limitation of the exact solution method is revealed and the performance of the presented GAs is compared. The results suggest that SAGA can achieve the best quality of solutions and HCGA should be the choice making good tradeoff between the solution quality and computing time.

  10. [Counsel for traveling children].

    Science.gov (United States)

    Sorge, F; Gendrel, D

    2013-01-01

    Consultation of child traveler has two main objectives: to assess of health risk related to the child's health status and history and also the risk related to travel environment; to counsel and prescribe preventive measure to reduce these travel health risks. The evaluation is based on physical examination and a detailed interview including personal history and information regarding the regions of proposed travel. Up to date knowledge of the epidemiology of visited sites, preventive measures and presumptive treatment is required. Essential health recommendations include, in case of exposure, prevention of malaria, arthropod borned diseases and vaccine preventable diseases. For all destinations advice regarding prevention of diarrhea, accident risks and aggravation of preexisting chronic diseases is needed. Universal primary prevention counselling is valuable for all travellers regardless of their age. In the case of children, special attention must be given to food and water hygiene, sun and heat exposure, swimming risks and transports security measures. Evaluation of risk and health education take time and often several visits are needed to complete the immunization schedule before departure.

  11. Negative Average Preference Utilitarianism

    Directory of Open Access Journals (Sweden)

    Roger Chao

    2012-03-01

    Full Text Available For many philosophers working in the area of Population Ethics, it seems that either they have to confront the Repugnant Conclusion (where they are forced to the conclusion of creating massive amounts of lives barely worth living, or they have to confront the Non-Identity Problem (where no one is seemingly harmed as their existence is dependent on the “harmful” event that took place. To them it seems there is no escape, they either have to face one problem or the other. However, there is a way around this, allowing us to escape the Repugnant Conclusion, by using what I will call Negative Average Preference Utilitarianism (NAPU – which though similar to anti-frustrationism, has some important differences in practice. Current “positive” forms of utilitarianism have struggled to deal with the Repugnant Conclusion, as their theory actually entails this conclusion; however, it seems that a form of Negative Average Preference Utilitarianism (NAPU easily escapes this dilemma (it never even arises within it.

  12. Dovekie - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  13. Razorbill - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  14. The traveling transect

    DEFF Research Database (Denmark)

    Braae, Ellen Marie; Diedrich, Lisa; Lee, Gini

    2013-01-01

    The practice of landscape architecture is most often a cultivation of open space alongside an open-ended dialogue with the presence and complexities of the cultural and natural features of places, usually resulting in projects generating site resolution rather than pure invention ex nihilo. However...... conditions, correspond to the fields of natural sciences and to spatial aesthetics. The Travelling Transect method, inspired by Alexander von Humboldt’s method of transareal travelling and transversal collecting of ephemeral information from site, informs our exploratory fieldwork in the water landscapes...

  15. Culture shock and travelers.

    Science.gov (United States)

    Stewart, L; Leggat, P A

    1998-06-01

    As travel has become easier and more affordable, the number of people traveling has risen sharply. People travel for many and varied reasons, from the business person on an overseas assignment to backpackers seeking new and exotic destinations. Others may take up residence in different regions, states or countries for family, business or political reasons. Other people are fleeing religious or political persecution. Wherever they go and for whatever reason they go, people take their culture with them. Culture, like language, is acquired innately in early childhood and is then reinforced through formal and complex informal social education into adulthood. Culture provides a framework for interpersonal and social interactions. Therefore, the contact with a new culture is often not the exciting or pleasurable experience anticipated. When immersed in a different culture, people no longer know how to act when faced with disparate value systems. Contact with the unfamiliar culture can lead to anxiety, stress, mental illness and, in extreme cases, physical illness and suicide. "Culture shock" is a term coined by the anthropologist Oberg. It is the shock of the new. It implies that the experience of the new culture is an unpleasant surprise or shock, partly because it is unexpected and partly because it can lead to a negative evaluation of one's own culture. It is also known as cross-cultural adjustment, being that period of anxiety and confusion experienced when entering a new culture. It affects people intellectually, emotionally, behaviorally and physically and is characterized by symptoms of psychological distress. Culture shock affects both adults and children. In travelers or workers who have prolonged sojourns in foreign countries, culture shock may occur not only as they enter the new culture, but also may occur on their return to their original culture. Children may also experience readjustment problems after returning from leading sheltered lives in expatriate

  16. Malaria prevention in travelers.

    Science.gov (United States)

    Genton, Blaise; D'Acremont, Valérie

    2012-09-01

    A common approach to malaria prevention is to follow the "A, B, C, D" rule: Awareness of risk, Bite avoidance, Compliance with chemoprophylaxis, and prompt Diagnosis in case of fever. The risk of acquiring malaria depends on the length and intensity of exposure; the risk of developing severe disease is primarily determined by the health status of the traveler. These parameters need to be assessed before recommending chemoprophylaxis and/or stand-by emergency treatment. This review discusses the different strategies and drug options available for the prevention of malaria during and post travel.

  17. Time a traveler's guide

    CERN Document Server

    Pickover, Clifford A

    1998-01-01

    ""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? P

  18. Existence, Uniqueness and Asymptotic Stability of Time Periodic Traveling Waves for a Periodic Lotka-Volterra Competition System with Diffusion.

    Science.gov (United States)

    Zhao, Guangyu; Ruan, Shigui

    2011-06-01

    We study the existence, uniqueness, and asymptotic stability of time periodic traveling wave solutions to a periodic diffusive Lotka-Volterra competition system. Under certain conditions, we prove that there exists a maximal wave speed c(*) such that for each wave speed c ≤ c(*), there is a time periodic traveling wave connecting two semi-trivial periodic solutions of the corresponding kinetic system. It is shown that such a traveling wave is unique modulo translation and is monotone with respect to its co-moving frame coordinate. We also show that the traveling wave solutions with wave speed c c(*).

  19. The travel-related carbon dioxide emissions of atmospheric researchers

    Science.gov (United States)

    Stohl, A.

    2008-11-01

    Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who like other scientists rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of CO2. In this paper, the CO2 emissions of the employees working at an atmospheric research institute (the Norwegian Institute for Air Research, NILU) caused by all types of business travel (conference visits, workshops, field campaigns, instrument maintainance, etc.) were calculated for the years 2005 2007. It is estimated that more than 90% of the emissions were caused by air travel, 3% by ground travel and 5% by hotel usage. The travel-related annual emissions were between 1.9 and 2.4 t CO2 per employee or between 3.9 and 5.5 t CO2 per scientist. For comparison, the total annual per capita CO2 emissions are 4.5 t worldwide, 1.2 t for India, 3.8 t for China, 5.9 t for Sweden and 19.1 t for Norway. The travel-related CO2 emissions of a NILU scientist, occurring in 24 days of a year on average, exceed the global average annual per capita emission. Norway's per-capita CO2 emissions are among the highest in the world, mostly because of the emissions from the oil industry. If the emissions per NILU scientist derived in this paper are taken as representative for the average Norwegian researcher, travel by Norwegian scientists would nevertheless account for a substantial 0.2% of Norway's total CO2 emissions. Since most of the travel-related emissions are due to air travel, water vapor emissions, ozone production and contrail formation further increase the relative importance of NILU's travel in terms of radiative forcing.

  20. Travel health. Part 1: preparing the tropical traveller.

    Science.gov (United States)

    Carroll, Bernadette; Daniel, Amanda; Behrens, Ron H

    The health threats of modern day travel change as population, wealth and tourism increase across the world. A series of three articles have been written to describe the spectrum of health issues associated with travel. Pre-travel health advice has become more focused on risk assessment and educating the traveller about infectious disease and the more frequent non-infectious hazards associated with travel, while ensuring they are not unnecessarily exposed to injury from vaccines and drugs. In part one, the role of the health advisor and the needs of the traveller are examined. The importance of risk assessment during a consultation is described and factors that influence recommendations and prescribing are explored. As most travel-associated morbidity and mortality is non-vaccine preventable, the focus of the pre-travel consultation should be on educating the traveller and influencing behaviour change. The second article in this series deals with the highest risk group of travellers--residents who visit friends and relatives. It highlights their specific problems and special needs and how to influence their risk of disease by addressing their health beliefs and their cultural dimension of risk. The third article explores the common, and not so common, clinical problems found in returned travellers. Nurses have to deal with a large range of clinical problems and diagnostic dilemmas when attending to the returned traveller. The review provides a perspective on the frequency and severity of problems and how nurses should manage travel associated disease.

  1. Transferring 2001 National Household Travel Survey

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Patricia S [ORNL; Reuscher, Tim [ORNL; Schmoyer, Richard L [ORNL; Chin, Shih-Miao [ORNL

    2007-05-01

    Policy makers rely on transportation statistics, including data on personal travel behavior, to formulate strategic transportation policies, and to improve the safety and efficiency of the U.S. transportation system. Data on personal travel trends are needed to examine the reliability, efficiency, capacity, and flexibility of the Nation's transportation system to meet current demands and to accommodate future demand. These data are also needed to assess the feasibility and efficiency of alternative congestion-mitigating technologies (e.g., high-speed rail, magnetically levitated trains, and intelligent vehicle and highway systems); to evaluate the merits of alternative transportation investment programs; and to assess the energy-use and air-quality impacts of various policies. To address these data needs, the U.S. Department of Transportation (USDOT) initiated an effort in 1969 to collect detailed data on personal travel. The 1969 survey was the first Nationwide Personal Transportation Survey (NPTS). The survey was conducted again in 1977, 1983, 1990, 1995, and 2001. Data on daily travel were collected in 1969, 1977, 1983, 1990 and 1995. In 2001, the survey was renamed the National Household Travel Survey (NHTS) and it collected both daily and long-distance trips. The 2001 survey was sponsored by three USDOT agencies: Federal Highway Administration (FHWA), Bureau of Transportation Statistics (BTS), and National Highway Traffic Safety Administration (NHTSA). The primary objective of the survey was to collect trip-based data on the nature and characteristics of personal travel so that the relationships between the characteristics of personal travel and the demographics of the traveler can be established. Commercial and institutional travel were not part of the survey. Due to the survey's design, data in the NHTS survey series were not recommended for estimating travel statistics for categories smaller than the combination of Census division (e.g., New

  2. WATER TUNNEL EXPERIMENTAL INVESTIGATION ON THE DRAG REDUCTION CHARACTERISTICS OF THE TRAVELING WAVY WALL

    Institute of Scientific and Technical Information of China (English)

    YAO Yan; LU Chuan-jing; SI Ting; ZHU Kun

    2011-01-01

    Drag reduction experiment of the traveling wavy wall at high Reynolds number is conducted. A suit of traveling wavy wall device is developed. The drag forces of the traveling wavy wall with various wave speeds ( c ) are measured under different water speeds (U) in the K15 cavitation water tunnel and are compared with that of the flat plate. The results show that the mean drag force of the traveling wavy wall have decreased and then increased with oscillation frequency increasing at the same flow speed.Under different flow speeds, when traveling wave wall reached to the minimum of drag force, the corresponding the ratio of the wall motion phase speed c to flow speed U, c/U is slightly different. Within the parameters of the experiment, when c/U reaches a certain value, the drag force of the traveling wavy wall can be less than that of the flat plate. The drag reduction can be up to 42%.Furthermore, as the value of c / U increases, the traveling wavy wall can restrain the separation and improve the quality of flow field.

  3. Beijing Time Travel

    Institute of Scientific and Technical Information of China (English)

    ROBERT T.TUOHEY

    2010-01-01

    @@ Dally travel within Beijing need not be anymore troublesome than going about any major metropolis.Simply,certain basic facts need to be kept in mind,and ordinary precautions taken.Essentially,it's the same situation as midtown Manhattan or downtown Tokyo,except everyone's speaking Chinese.

  4. Beijing Time Travel

    Institute of Scientific and Technical Information of China (English)

    ROBERT; T.TUOHEY

    2010-01-01

    Daily travel within Beijing need not be anymore troublesome than going about any major metropolis.Simply,certain basic facts need to be kept in mind,and ordinary precautions taken.Essentially,it’s the same situation as midtown Manhattan or downtown Tokyo,except everyone’s speaking Chinese.

  5. Gulliver's Travels. [Lesson Plan].

    Science.gov (United States)

    Rooks, Kirsten; McLean, Mary

    Based on Jonathan Swift's novel "Gulliver's Travels," this lesson plan presents activities designed to help students understand that Swift comments on undesirable outcomes of advances in science; and other authors have also warned against abuse of science. The main activity of the lesson involves students developing a poster illustrating views of…

  6. 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.

  7. 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 variou

  8. On China's High-Speed Railway Technology

    Institute of Scientific and Technical Information of China (English)

    You-tong FANG

    2011-01-01

    Energy and environmental issues have become increasingly prominent in matters of transportation.Compared with road,air,and sea transportation,railway transportation has the advantages of a large transmission capacity,with rapid,safe,and on-time travel,requiring less land resources,with lower energy consumption,less environmental pollution,and the capacity to operate under most weather conditions.In particular,high-speed railway technology has been growing rapidly.Since the world's first high-speed railway was built in Japan in 1964,more than ten countries and regions have developed high-speed railways,operating over a total of more than 10000 km.High-speed railways not only provide the public with a new type of rapid,convenient,safe,and comfortable travel,but also greatly boost the socio-economic development of the country.

  9. Speed mathematics

    CERN Document Server

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  10. 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....

  11. Epidemic spreading by objective traveling

    Science.gov (United States)

    Tang, Ming; Liu, Zonghua; Li, Baowen

    2009-07-01

    A fundamental feature of agent traveling in social networks is that traveling is usually not a random walk but with a specific destination and goes through the shortest path from starting to destination. A serious consequence of the objective traveling is that it may result in a fast epidemic spreading, such as SARS etc. In this letter we present a reaction-traveling model to study how the objective traveling influences the epidemic spreading. We consider a random scale-free meta-population network with sub-population at each node. Through a SIS model we theoretically prove that near the threshold of epidemic outbreak, the objective traveling can significantly enhance the final infected population and the infected fraction at a node is proportional to its betweenness for the traveling agents and approximately proportional to its degree for the non-traveling agents. Numerical simulations have confirmed the theoretical predictions.

  12. 75 FR 43395 - Campaign Travel

    Science.gov (United States)

    2010-07-26

    ... Campaign Travel AGENCY: Federal Election Commission. ACTION: Announcement of effective date. SUMMARY: On... of the Honest Leadership and Open Government Act governing campaign travel on noncommercial aircraft.... SUPPLEMENTARY INFORMATION: On December 7, 2009, the Commission published final rules governing campaign...

  13. Travel opinion leaders and seekers

    DEFF Research Database (Denmark)

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

    2011-01-01

    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......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...

  14. Travel, speed and entertainment in cinema territories and aviation

    Directory of Open Access Journals (Sweden)

    João Luís Jesus Fernandes

    2016-02-01

    Full Text Available Book review and critical reading of a book that crosses cinema and the aviation transport, a work that understands the latter as a territory of cinema diffusion. The films shown in the aircraft are designed to entertain the passengers, keep them calm, but also to promote marketing campaigns and lifestyles.

  15. Travel and Adventure Medicine Resources.

    Science.gov (United States)

    Sanford, Christopher A; Pottinger, Paul S

    2016-03-01

    Given the ever-changing nature of travel medicine, practitioners who provide pretravel and posttravel care are obligatorily students for the duration of their professional careers. A large variety of resources are available for medical practitioners. Providers should join at least one travel or tropical medicine professional association, attend its annual meeting, and read its journal. The largest general travel medicine association is the International Society of Travel Medicine.

  16. The Stiffness Variation of a Micro-Ring Driven by a Traveling Piecewise-Electrode

    Directory of Open Access Journals (Sweden)

    Yingjie Li

    2014-09-01

    Full Text Available In the practice of electrostatically actuated micro devices; the electrostatic force is implemented by sequentially actuated piecewise-electrodes which result in a traveling distributed electrostatic force. However; such force was modeled as a traveling concentrated electrostatic force in literatures. This article; for the first time; presents an analytical study on the stiffness variation of microstructures driven by a traveling piecewise electrode. The analytical model is based on the theory of shallow shell and uniform electrical field. The traveling electrode not only applies electrostatic force on the circular-ring but also alters its dynamical characteristics via the negative electrostatic stiffness. It is known that; when a structure is subjected to a traveling constant force; its natural mode will be resonated as the traveling speed approaches certain critical speeds; and each natural mode refers to exactly one critical speed. However; for the case of a traveling electrostatic force; the number of critical speeds is more than that of the natural modes. This is due to the fact that the traveling electrostatic force makes the resonant frequencies of the forward and backward traveling waves of the circular-ring different. Furthermore; the resonance and stability can be independently controlled by the length of the traveling electrode; though the driving voltage and traveling speed of the electrostatic force alter the dynamics and stabilities of microstructures. This paper extends the fundamental insights into the electromechanical behavior of microstructures driven by electrostatic forces as well as the future development of MEMS/NEMS devices with electrostatic actuation and sensing.

  17. Cloud speed sensor

    Directory of Open Access Journals (Sweden)

    V. Fung

    2013-10-01

    Full Text Available Changing cloud cover is a major source of solar radiation variability and poses challenges for the integration of solar energy. A compact and economical system that measures cloud motion vectors to estimate power plant ramp rates and provide short term solar irradiance forecasts is presented. The Cloud Speed Sensor (CSS is constructed using an array of luminance sensors and high-speed data acquisition to resolve the progression of cloud passages across the sensor footprint. An embedded microcontroller acquires the sensor data and uses a cross-correlation algorithm to determine cloud motion vectors. The CSS was validated against an artificial shading test apparatus, an alternative method of cloud motion detection from ground measured irradiance (Linear Cloud Edge, LCE, and a UC San Diego Sky Imager (USI. The CSS detected artificial shadow directions and speeds to within 15 and 6% accuracy, respectively. The CSS detected (real cloud directions and speeds without average bias and with average weighted root mean square difference of 22° and 1.9 m s−1 when compared to USI and 33° and 1.5 m s−1 when compared to LCE results.

  18. Elasticity of Long Distance Travelling

    DEFF Research Database (Denmark)

    Knudsen, Mette Aagaard

    2011-01-01

    a household. Due to a high share of corner solutions among the expenditures on plane tickets and package travelling, the expenditures on these specific commodities are examined with a Tobit approach. The model results find both plane tickets and travel packages to be luxury goods. It also states that travel...

  19. Lattice Boltzmann simulation of transverse wave travelling in Maxwell viscoelastic fluid

    Institute of Scientific and Technical Information of China (English)

    Li Hua-Bing; Fang Hai-Ping

    2004-01-01

    A nine-velocity lattice Boltzmann method for Maxwell viscoelastic fluid is proposed. Travelling of transverse wave in Maxwell viscoelastic fluid is simulated. The instantaneous oscillating velocity, transverse shear speed and decay rate agree with theoretical results very well.

  20. 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 ...

  1. Remote sensing of temperature and wind using acoustic travel-time measurements

    Directory of Open Access Journals (Sweden)

    Manuela Barth

    2013-04-01

    Full Text Available A remote sensing technique to detect area-averaged temperature and flow properties within an area under investigation, utilizing acoustic travel-time measurements, is introduced. This technique uses the dependency of the speed of acoustic signals on the meteorological parameters temperature and wind along the propagation path. The method itself is scalable: It is applicable for investigation areas with an extent of some hundred square metres as well as for small-scale areas in the range of one square metre. Moreover, an arrangement of the acoustic transducers at several height levels makes it possible to determine profiles and gradients of the meteorological quantities. With the help of two examples the potential of this remote sensing technique for simultaneously measuring averaged temperature and flow fields is demonstrated. A comparison of time histories of temperature and wind values derived from acoustic travel-time measurements with point measurements shows a qualitative agreement whereas calculated root-mean-square errors differ for the two example applications. They amount to 1.4 K and 0.3 m/s for transducer distances of 60 m and 0.4 K and 0.2 m/s for transducer distances in the range of one metre.

  2. Existence of travelling wave solutions for a Fisher-Kolmogorov system with biomedical applications

    Science.gov (United States)

    Belmonte-Beitia, Juan

    2016-07-01

    We consider a Fisher-Kolmogorov system with applications in oncology Pérez-García et al. (2015). Of interest is the question of the existence of travelling front solutions of the system. When the speed of the travelling wave is sufficiently large, existence of such fronts is shown using singular geometric perturbation theory.

  3. The severe acute respiratory syndrome: impact on travel and tourism.

    Science.gov (United States)

    Wilder-Smith, Annelies

    2006-03-01

    SARS and travel are intricately interlinked. Travelers belonged to those primarily affected in the early stages of the outbreak, travelers became vectors of the disease, and finally, travel and tourism themselves became the victims. The outbreak of SARS created international anxiety because of its novelty, its ease of transmission in certain settings, and the speed of its spread through jet travel, combined with extensive media coverage. The psychological impacts of SARS, coupled with travel restrictions imposed by various national and international authorities, have diminished international travel in 2003, far beyond the limitations to truly SARS hit areas. Governments and press, especially in non SARS affected areas, have been slow to strike the right balance between timely and frequent risk communication and placing risk in the proper context. Screening at airport entry points is costly, has a low yield and is not sufficient in itself. The low yield in detecting SARS is most likely due to a combination of factors, such as travel advisories which resulted in reduced travel to and from SARS affected areas, implementation of effective pre-departure screening at airports in SARS-hit countries, and a rapid decline in new cases at the time when screening was finally introduced. Rather than investing in airport screening measures to detect rare infectious diseases, investments should be used to strengthen screening and infection control capacities at points of entry into the healthcare system. If SARS reoccurs, the subsequent outbreak will be smaller and more easily contained if the lessons learnt from the recent epidemic are applied. Lessons learnt during the outbreak in relation to international travel will be discussed.

  4. Aging and space travel

    Science.gov (United States)

    Mohler, S. R.

    1982-01-01

    The matter of aging and its relation to space vehicle crewmembers undertaking prolonged space missions is addressed. The capabilities of the older space traveler to recover from bone demineralization and muscle atrophy are discussed. Certain advantages of the older person are noted, for example, a greater tolerance of monotony and repetitious activities. Additional parameters are delineated including the cardiovascular system, the reproductive system, ionizing radiation, performance, and group dynamics.

  5. 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.

  6. Diversity does not travel!

    DEFF Research Database (Denmark)

    Lund, Rebecca; Meriläinen, Susan; Tienari, Janne

    2014-01-01

    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....

  7. 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.

  8. [Traveling with small children].

    Science.gov (United States)

    Olivier, C

    1997-01-01

    Traveling with children especially in the tropics requires special planning. Contraindications are rare but care providers should obtain information about medical and transfusional facilities at the destination. Children should receive all vaccinations required for international travel and for specific countries, taking into account age, location, duration of stay, and purpose of trip. A first aid kit should be packed containing a thermometer, bandages, antiseptic agents, a total sunscreen preparation, a mosquito net, sterile compresses, tablets for water disinfection, and indispensable medications (antimalarial agents, antipyretics, oral rehydration solutions, antiemetics, and eye wash). The main indication for chemoprophylaxis is malaria. Chloroquine is recommended for most locations but proguanil may be necessary in areas of resistance. Special attention must be paid to skin care in infants: maintaining cleanliness, avoiding cuts insofar as possible, and treating any wounds. Clothing must be carefully laundered and adequate to prevent overexposure to sunlight and insect bites. Insect bites must also be prevented by applying repellents, using mosquito nets, and wearing insecticide-treated garments. Handwashing by people who prepare meals and by the children before eating is important to prevent food poisoning. Breast feeding is advisable for infants. Thorough cooking of meats, rinsing of fresh produce, drinking of bottled beverages, and sterilization of water are also important food safety measures. These precautions are usually adequate to allow safe travel with children.

  9. 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 ...

  10. Carlson Wagonlit Travel

    CERN Multimedia

    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...

  11. Superluminal travel requires negative energies

    OpenAIRE

    Olum, Ken D.

    1998-01-01

    I investigate the relationship between faster-than-light travel and weak-energy-condition violation, i.e., negative energy densities. In a general spacetime it is difficult to define faster-than-light travel, and I give an example of a metric which appears to allow superluminal travel, but in fact is just flat space. To avoid such difficulties, I propose a definition of superluminal travel which requires that the path to be traveled reach a destination surface at an earlier time than any neig...

  12. Ring aggregation pattern of Human Travel Trips

    CERN Document Server

    Wang, Zi-Yang; Zhu, Peng; Qin, Yong; Jia, Li-Min

    2015-01-01

    Although a lot of attentions have been paid to human mobility, the relationship between travel pattern with city structure is still unclear. Here we probe into this relationship by analyzing the metro passenger trip data.There are two unprecedented findings. One, from the average view a linear law exists between the individual's travel distance with his original distance to city center. The mechanism underlying is a travel pattern we called "ring aggregation", i.e., the daily movement of city passengers is just aggregating to a ring with roughly equal distance to city center.Interestingly, for the round trips the daily travel pattern can be regarded as a switching between the home ring at outer area with the office ring at the inner area. Second, this linear law and ring aggregation pattern seems to be an exclusive characteristic of the metro system. It can not be found in short distance transportation modes, such as bicycle and taxi, neither as multiple transportation modes. This means the ring aggregation p...

  13. Unconscious local motion alters global image speed.

    Directory of Open Access Journals (Sweden)

    Sieu K Khuu

    Full Text Available Accurate motion perception of self and object speed is crucial for successful interaction in the world. The context in which we make such speed judgments has a profound effect on their accuracy. Misperceptions of motion speed caused by the context can have drastic consequences in real world situations, but they also reveal much about the underlying mechanisms of motion perception. Here we show that motion signals suppressed from awareness can warp simultaneous conscious speed perception. In Experiment 1, we measured global speed discrimination thresholds using an annulus of 8 local Gabor elements. We show that physically removing local elements from the array attenuated global speed discrimination. However, removing awareness of the local elements only had a small effect on speed discrimination. That is, unconscious local motion elements contributed to global conscious speed perception. In Experiment 2 we measured the global speed of the moving Gabor patterns, when half the elements moved at different speeds. We show that global speed averaging occurred regardless of whether local elements were removed from awareness, such that the speed of invisible elements continued to be averaged together with the visible elements to determine the global speed. These data suggest that contextual motion signals outside of awareness can both boost and affect our experience of motion speed, and suggest that such pooling of motion signals occurs before the conscious extraction of the surround motion speed.

  14. Rabies vaccination for international travelers.

    Science.gov (United States)

    Gautret, Philippe; Parola, Philippe

    2012-01-05

    Rabies prevention in travelers is a controversial issue. According to experts, the decision to vaccinate results from an individual risk assessment based on the duration of stay, the likelihood of engagement in at-risk activities, the age of the traveler, the rabies endemicity and access to appropriate medical care in the country of destination. However, no detailed information is available regarding the last two determinants in many regions. Twenty-two cases of rabies were reported in tourists, expatriates and migrant travelers over the last decade, including three cases following short-term travel of no more than two weeks. Studies on rabies post-exposure prophylaxis (PEP) in travelers show that overall, 0.4% (range 0.01-2.3%) of travelers have experienced an at-risk bite per month of stay in a rabies-endemic country, while 31% of expatriates and 12% of tourists were vaccinated against rabies before traveling. The main reason cited by travelers for not being vaccinated is the cost of the vaccine. The majority of patients who sustained a high risk injury was not vaccinated against rabies before traveling and were not properly treated abroad. From available studies, the following risk factors for injuries sustained from potentially rabid animals may be identified: traveling to South-East Asia, India or North Africa, young age, and traveling for tourism. The duration of travel does not appear to be a risk factor. It should be noted that "at-risk activities" have not been addressed in these studies. Detailed rabies distribution maps and information on the availability of rabies biologics are urgently needed in order to identify those travelers who need pre-travel vaccination. Meanwhile, cost-minimization of rabies pre-exposure vaccination may be achieved in several ways, notably by using the intra-dermal method of vaccination.

  15. 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.

  16. Travelling Waves in Hybrid Chemotaxis Models

    KAUST Repository

    Franz, Benjamin

    2013-12-18

    Hybrid models of chemotaxis combine agent-based models of cells with partial differential equation models of extracellular chemical signals. In this paper, travelling wave properties of hybrid models of bacterial chemotaxis are investigated. Bacteria are modelled using an agent-based (individual-based) approach with internal dynamics describing signal transduction. In addition to the chemotactic behaviour of the bacteria, the individual-based model also includes cell proliferation and death. Cells consume the extracellular nutrient field (chemoattractant), which is modelled using a partial differential equation. Mesoscopic and macroscopic equations representing the behaviour of the hybrid model are derived and the existence of travelling wave solutions for these models is established. It is shown that cell proliferation is necessary for the existence of non-transient (stationary) travelling waves in hybrid models. Additionally, a numerical comparison between the wave speeds of the continuum models and the hybrid models shows good agreement in the case of weak chemotaxis and qualitative agreement for the strong chemotaxis case. In the case of slow cell adaptation, we detect oscillating behaviour of the wave, which cannot be explained by mean-field approximations. © 2013 Society for Mathematical Biology.

  17. Time, travel and infection.

    Science.gov (United States)

    Cliff, Andrew; Haggett, Peter

    2004-01-01

    The collapse of geographical space over the last 200 years has had profound effects on the circulation of human populations and on the transfer of infectious diseases. Three examples are used to illustrate the process: (a) the impact of the switch from sail to steamships in importing measles into Fiji over a 40-year period; (b) changes in measles epidemic behaviour in Iceland over a 150-year period; and (c) changes in the spread of cholera within the United States over a 35-year period. In each case, the link between time, travel and disease has been an intimate one.

  18. Travel Demand Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, Frank [ORNL; Garrow, Dr. Laurie [Georgia Institute of Technology

    2011-01-01

    This chapter describes the principal types of both passenger and freight demand models in use today, providing a brief history of model development supported by references to a number of popular texts on the subject, and directing the reader to papers covering some of the more recent technical developments in the area. Over the past half century a variety of methods have been used to estimate and forecast travel demands, drawing concepts from economic/utility maximization theory, transportation system optimization and spatial interaction theory, using and often combining solution techniques as varied as Box-Jenkins methods, non-linear multivariate regression, non-linear mathematical programming, and agent-based microsimulation.

  19. The SUN S TRAVELS

    Institute of Scientific and Technical Information of China (English)

    Robert; Louis; Stevenson

    2005-01-01

    The sun is not a-bed, when I At night upon my pillow lie; Stilt round the earth his Way he takes, And morning after morning makes. White here at home, in shining day, We round the sunny garden play, Each tittle Indian sleepy - head Is being kissed and put to bed. And When at eve I rise from tea, Day dawns beyond the Atlantic Sea; And all the children in the West Are getting up and being dressed.The SUN'S TRAVELS@Robert Louis Stevenson

  20. Travelling fronts in stochastic Stokes’ drifts

    KAUST Repository

    Blanchet, Adrien

    2008-10-01

    By analytical methods we study the large time properties of the solution of a simple one-dimensional model of stochastic Stokes\\' drift. Semi-explicit formulae allow us to characterize the behaviour of the solutions and compute global quantities such as the asymptotic speed of the center of mass or the effective diffusion coefficient. Using an equivalent tilted ratchet model, we observe that the speed of the center of mass converges exponentially to its limiting value. A diffuse, oscillating front attached to the center of mass appears. The description of the front is given using an asymptotic expansion. The asymptotic solution attracts all solutions at an algebraic rate which is determined by the effective diffusion coefficient. The proof relies on an entropy estimate based on homogenized logarithmic Sobolev inequalities. In the travelling frame, the macroscopic profile obeys to an isotropic diffusion. Compared with the original diffusion, diffusion is enhanced or reduced, depending on the regime. At least in the limit cases, the rate of convergence to the effective profile is always decreased. All these considerations allow us to define a notion of efficiency for coherent transport, characterized by a dimensionless number, which is illustrated on two simple examples of travelling potentials with a sinusoidal shape in the first case, and a sawtooth shape in the second case. © 2008 Elsevier B.V. All rights reserved.

  1. Large deviations for a random speed particle

    CERN Document Server

    Lefevere, Raphael; Zambotti, Lorenzo

    2011-01-01

    We investigate large deviations for the empirical measure of the position and momentum of a particle traveling in a box with hot walls. The particle travels with uniform speed from left to right, until it hits the right boundary. Then it is absorbed and re-emitted from the left boundary with a new random speed, taken from an i.i.d. sequence. It turns out that this simple model, often used to simulate a heat bath, displays unusually complex large deviations features, that we explain in detail. In particular, if the tail of the update distribution of the speed is sufficiently oscillating, then the empirical measure does not satisfy a large deviations principle, and we exhibit optimal lower and upper large deviations functionals.

  2. 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...

  3. Ion Acoustic Travelling Waves

    CERN Document Server

    Webb, G M; Ao, X; Zank, G P

    2013-01-01

    Models for travelling waves in multi-fluid plasmas give essential insight into fully nonlinear wave structures in plasmas, not readily available from either numerical simulations or from weakly nonlinear wave theories. We illustrate these ideas using one of the simplest models of an electron-proton multi-fluid plasma for the case where there is no magnetic field or a constant normal magnetic field present. We show that the travelling waves can be reduced to a single first order differential equation governing the dynamics. We also show that the equations admit a multi-symplectic Hamiltonian formulation in which both the space and time variables can act as the evolution variable. An integral equation useful for calculating adiabatic, electrostatic solitary wave signatures for multi-fluid plasmas with arbitrary mass ratios is presented. The integral equation arises naturally from a fluid dynamics approach for a two fluid plasma, with a given mass ratio of the two species (e.g. the plasma could be an electron pr...

  4. Traveling-Wave Tubes

    Science.gov (United States)

    Kory, Carol L.

    1998-01-01

    The traveling-wave tube (TWT) is a vacuum device invented in the early 1940's used for amplification at microwave frequencies. Amplification is attained by surrendering kinetic energy from an electron beam to a radio frequency (RF) electromagnetic wave. The demand for vacuum devices has been decreased largely by the advent of solid-state devices. However, although solid state devices have replaced vacuum devices in many areas, there are still many applications such as radar, electronic countermeasures and satellite communications, that require operating characteristics such as high power (Watts to Megawatts), high frequency (below 1 GHz to over 100 GHz) and large bandwidth that only vacuum devices can provide. Vacuum devices are also deemed irreplaceable in the music industry where musicians treasure their tube-based amplifiers claiming that the solid-state and digital counterparts could never provide the same "warmth" (3). The term traveling-wave tube includes both fast-wave and slow-wave devices. This article will concentrate on slow-wave devices as the vast majority of TWTs in operation fall into this category.

  5. The Travelling Telescope

    Science.gov (United States)

    Murabona Oduori, Susan

    2015-08-01

    The telescope has been around for more than 400 years, and through good use of it scientists have made many astonishing discoveries and begun to understand our place in the universe. Most people, however, have never looked through one. Yet it is a great tool for cool science and observation especially in a continent and country with beautifully dark skies. The Travelling Telescope project aims to invite people outside under the stars to learn about those curious lights in the sky.The Travelling Telescope aims to promote science learning to a wide range of Kenyan schools in various locations exchanging knowledge about the sky through direct observations of celestial bodies using state of the art telescopes. In addition to direct observing we also teach science using various hands-on activities and astronomy software, ideal for explaining concepts which are hard to understand, and for a better grasp of the sights visible through the telescope. We are dedicated to promoting science using astronomy especially in schools, targeting children from as young as 3 years to the youth, teachers, their parents and members of the public. Our presentation focuses on the OAD funded project in rural coastal Kenya.

  6. A Discrete Velocity Kinetic Model with Food Metric: Chemotaxis Traveling Waves.

    Science.gov (United States)

    Choi, Sun-Ho; Kim, Yong-Jung

    2017-02-01

    We introduce a mesoscopic scale chemotaxis model for traveling wave phenomena which is induced by food metric. The organisms of this simplified kinetic model have two discrete velocity modes, [Formula: see text] and a constant tumbling rate. The main feature of the model is that the speed of organisms is constant [Formula: see text] with respect to the food metric, not the Euclidean metric. The uniqueness and the existence of the traveling wave solution of the model are obtained. Unlike the classical logarithmic model case there exist traveling waves under super-linear consumption rates and infinite population pulse-type traveling waves are obtained. Numerical simulations are also provided.

  7. Physical Theories with Average Symmetry

    OpenAIRE

    Alamino, Roberto C.

    2013-01-01

    This Letter probes the existence of physical laws invariant only in average when subjected to some transformation. The concept of a symmetry transformation is broadened to include corruption by random noise and average symmetry is introduced by considering functions which are invariant only in average under these transformations. It is then shown that actions with average symmetry obey a modified version of Noether's Theorem with dissipative currents. The relation of this with possible violat...

  8. Average Convexity in Communication Situations

    NARCIS (Netherlands)

    Slikker, M.

    1998-01-01

    In this paper we study inheritance properties of average convexity in communication situations. We show that the underlying graph ensures that the graphrestricted game originating from an average convex game is average convex if and only if every subgraph associated with a component of the underlyin

  9. CONCEPTUAL CLARIFICATIONS REGARDING YOUTH TRAVEL

    OpenAIRE

    Lect. Ph.D Student Moisa Claudia Olimpia

    2010-01-01

    Currently, there is no clear definition for the youth travel concept. This concept emerged much latter than the first forms of manifestation of tourism for young people, namely the beginning of the ’90s when the first studies regarding youth travel were also conducted. No doubt, the concept of youth travel ensues from three notions, namely: youth, tourism and vacation – in the sense of free time. All the definitions used by tourism organizations, by various national tourism administrations an...

  10. Communication from Carlson Wagonlit Travel

    CERN Multimedia

    2008-01-01

    Entry requirements for the USA: "ESTA" (Electronic System for Travel Authorization) online registration The requirement to register before entering the USA announced by the Department of Homeland Security (DHS) is to be introduced on 12 January 2009. Visitors to the USA will then be required to register their personal data and travel data online not less than 72 hours prior to travel. https://esta.cbp.dhs.gov/ General information on entry requirements for the USA are also available on the Carlson Wagonlit Travel website under the heading „CWT informs": http://www.carlsonwagonlit.ch

  11. Communication from Carlson Wagonlit Travel

    CERN Multimedia

    2009-01-01

    Entry requirements for the USA: "ESTA" (Electronic System for Travel Authorization) online registration The requirement to register before entering the USA announced by the Department of Homeland Security (DHS) is to be introduced on 12 January 2009. Visitors to the USA will then be required to register their personal data and travel data online not less than 72 hours prior to travel. https://esta.cbp.dhs.gov/ General information on entry requirements for the USA is also available on the Carlson Wagonlit Travel website under the heading „CWT informs": http://www.carlsonwagonlit.ch

  12. Sampling Based Average Classifier Fusion

    Directory of Open Access Journals (Sweden)

    Jian Hou

    2014-01-01

    fusion algorithms have been proposed in literature, average fusion is almost always selected as the baseline for comparison. Little is done on exploring the potential of average fusion and proposing a better baseline. In this paper we empirically investigate the behavior of soft labels and classifiers in average fusion. As a result, we find that; by proper sampling of soft labels and classifiers, the average fusion performance can be evidently improved. This result presents sampling based average fusion as a better baseline; that is, a newly proposed classifier fusion algorithm should at least perform better than this baseline in order to demonstrate its effectiveness.

  13. The General Traveling Salesman Problem

    CERN Document Server

    Kleiman, Howard

    2011-01-01

    This is concerned with essentially two ways in which to construct algorithms for obtaining both approximate and exact solutions to the general traveling salesman problem (GTSP)(the triangle equality need not be satisfied). The first uses an arbitrary n-cycle to permute the columns of an n X n matrix with weighted entries. In doing so, we obtain negative entries. Using these entries, we from negative cycles. We give a formula for the length of cycles necessary to obtain an n-cycle by patching. Using patching of negative cycles, we obtain an n-cycle. The second portion of the algorithm gives procedures for obtain an exact solution to the GTSP. Our second algorithm uses the average arc-value (aav) of a path. We first obtain an n-cycle in a manner similar to that in the first algorithm. Call this T_UPPERBOUND. We then construct paths each of which has an aav less than that of T_UPPERBOUND. Using parallel programming, we construct all paths whose values are less than that of T_UPPERBOUND. Then either we obtain an ...

  14. Stimulus motion propels traveling waves in binocular rivalry.

    Directory of Open Access Journals (Sweden)

    Tomas Knapen

    Full Text Available State transitions in the nervous system often take shape as traveling waves, whereby one neural state is replaced by another across space in a wave-like manner. In visual perception, transitions between the two mutually exclusive percepts that alternate when the two eyes view conflicting stimuli (binocular rivalry may also take shape as traveling waves. The properties of these waves point to a neural substrate of binocular rivalry alternations that have the hallmark signs of lower cortical areas. In a series of experiments, we show a potent interaction between traveling waves in binocular rivalry and stimulus motion. The course of the traveling wave is biased in the motion direction of the suppressed stimulus that gains dominance by means of the wave-like transition. Thus, stimulus motion may propel the traveling wave across the stimulus to the extent that the stimulus motion dictates the traveling wave's direction completely. Using a computational model, we show that a speed-dependent asymmetry in lateral inhibitory connections between retinotopically organized and motion-sensitive neurons can explain our results. We argue that such a change in suppressive connections may play a vital role in the resolution of dynamic occlusion situations.

  15. A study on the Antarctic circumpolar wave mode-A coexistence system of standing and traveling wave

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Antarctic circumpolar wave (ACW) has become a focus of the air-sea coupled Southern Ocean study since 1996, when it was discovered as an air-sea coupled interannual signal propagating eastward in the region of the Antarctic Circumpolar Current (ACC). In order to analyze the mechanism of discontinuity along the latitudinal propagation, a new idea that ACW is a system with a traveling wave in the Southern Pacific and Atlantic Ocean and with a concurrent standing wave in the southern Indian Ocean is proposed in this paper. Based on the ideal wave principle, the average wave parameters of ACW is achieved using a non-linear approximation method, by which we find that the standing part and the traveling part possess similar radius frequency, proving their belonging to an integral system. We also give the latitudinal distribution of wave speed with which we could tell the reason for steady propagation during the same period. The spatial distribution of the propagation reveals complex process with variant spatial and temporal scales-The ENSO scale oscillation greatly impacts on the traveling process, while the result at the south of Australia indicates little connection between the Indian Ocean and the Pacific, which may be blocked by the vibration at the west of the Pacific. The advective effect of ACC on the propagation process should be examined clearly through dynamical method.

  16. Solar wind travel time

    Science.gov (United States)

    Russell, C. T.

    A useful rule of thumb in solar terrestrial studies is that the solar wind travels 4 Earth radii (RE) per minute. Long-term studies of solar wind velocity [e.g., Luhmann et al., 1993; 1994] show that the median velocity is about 420 km/s, corresponding to 3.96 RE min-1. The quartiles are about 370 km/s and 495 km/s, corresponding to 3.48 Re min-1 and 4.66 Re min-1 respectively. This number helps estimate the delays expected when observing a discontinuity at a solar wind monitor; one example is ISEE-3 when it was at the forward libration point (about 60 min). It is also helpful for estimating how much time passes before the dayside magnetosphere is compressed as denser solar wind flows by (about 2.5 min).

  17. Determination of Scheduled Travel Time for a Fixed Transit Route Based on Multistate Model

    Institute of Scientific and Technical Information of China (English)

    Shukai Chen; Daniel Jian Sun; and Rui Xue

    2016-01-01

    In order to provide the guideline for bus drivers to adjust speed to minimize scheduled deviation, the method for setting bus scheduled travel time is proposed. Firstly, multistate model is introduced to fit historical travel time data and identify different service states. Based on the calibrated travel time distribution parameters, an optimization model is proposed, followed by a Monte Carlo ( MC) simulation based genetic algorithm ( GA) procedure to obtain the optimal scheduled time. A case study from a fixed bus route from Shenzhen is used to demonstrate the model applicability. The sensitivity analysis is conducted to study the effects of parameters setting on optimal slack time for each segment. The results show that multistate model fits travel time under peak hours better than Lognormal distribution, and the length of scheduled travel time basically reflects travel time reliability.

  18. The Electromechanical Behavior of a Micro-Ring Driven by Traveling Electrostatic Force

    Directory of Open Access Journals (Sweden)

    Kuo-Yi Huang

    2012-01-01

    Full Text Available There is no literature mentioning the electromechanical behavior of micro structures driven by traveling electrostatic forces. This article is thus the first to present the dynamics and stabilities of a micro-ring subjected to a traveling electrostatic force. The traveling electrostatic force may be induced by sequentially actuated electrodes which are arranged around the flexible micro-ring. The analysis is based on a linearized distributed model considering the electromechanical coupling effects between electrostatic force and structure. The micro-ring will resonate when the traveling speeds of the electrostatic force approach some critical speeds. The critical speeds are equal to the ratio of the natural frequencies to the wave number of the correlative natural mode of the ring. Apart from resonance, the ring may be unstable at some unstable traveling speeds. The unstable regions appear not only near the critical speeds, but also near some fractions of some critical speeds differences. Furthermore the unstable regions expand with increasing driving voltage. This article may lead to a new research branch on electrostatic-driven micro devices.

  19. 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

  20. Physical Theories with Average Symmetry

    CERN Document Server

    Alamino, Roberto C

    2013-01-01

    This Letter probes the existence of physical laws invariant only in average when subjected to some transformation. The concept of a symmetry transformation is broadened to include corruption by random noise and average symmetry is introduced by considering functions which are invariant only in average under these transformations. It is then shown that actions with average symmetry obey a modified version of Noether's Theorem with dissipative currents. The relation of this with possible violations of physical symmetries, as for instance Lorentz invariance in some quantum gravity theories, is briefly commented.

  1. 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 ti

  2. EFFECT OF CONGESTION ON FUEL COST AND TRAVEL TIME COST ON MULTI-LANE HIGHWAYS IN INDIA

    Directory of Open Access Journals (Sweden)

    Madhu Errampalli

    2015-12-01

    Full Text Available The vehicles normally move at their free speeds when it is least impeded due to traffic flow under lean traffic (free flow conditions. As traffic flow increases, the vehicles cannot sustain their free speeds due to interactions from other vehicles in the traffic stream. In addition to that the vehicles that are operating in the congested traffic conditions will consume more fuel than those operating in steady state traffic conditions for the same average speed. This leads to increase in travel time and fuel consumption of the vehicles and thereby adding to total road user cost (RUC. On the contrary, fuel consumption is also high at very high speeds under free flow traffic flow conditions leading to increase RUC. Considering these scenarios, the travel time and fuel cost of the vehicle due to the congestion and free flow conditions (uncongested has to be necessarily modelled in order to estimate realistic assessment of RUC on Indian highways. In the present study, the congestion cost relationships have been developed between Congestion Factor, a ratio of cost under congestion and steady state conditions and Volume-Capacity Ratio by considering various vehicle types plying on varying widths of multi-lane highways (four, six and eight lane divided carriageways through the collection of exhaustive time related and fuel related data. Time related data was collected through questionnaire survey method whereas fuel consumption data was collected using advanced sophisticated fuel flow measuring equipment (V-Box. The developed equations have been successfully applied to demonstrate their applicability in terms of estimating realistic effect of congestion on time and fuel cost by considering a section on NH-2 in Delhi. The analysis shows that the congestion effect is more significant on fuel cost for heavy commercial vehicles whereas it is more prominent on time cost for passenger vehicles. However, the congestion effect on combined fuel and time cost is

  3. Traveling Wave Solutions for Lotka-Volterra System Re-Visited

    CERN Document Server

    Leung, Anthony W; Feng, Wei

    2009-01-01

    Using a new method of monotone iteration of a pair of smooth lower- and upper-solutions, the traveling wave solutions of the classical Lotka-Volterra system are shown to exist for a family of wave speeds. Such constructed upper and lower solution pair enables us to derive the explicit value of the minimal (critical) wave speed as well as the asymptotic rates of the wave solutions at infinities. Furthermore, the traveling wave corresponding to each wave speed is unique modulo a translation of the origin. The stability of the traveling wave solutions with non-critical wave speed is also studied by spectral analysis of the linearized operator in exponentially weighted Banach spaces.

  4. Spatial-Temporal Analysis on Spring Festival Travel Rush in China Based on Multisource Big Data

    Directory of Open Access Journals (Sweden)

    Jiwei Li

    2016-11-01

    Full Text Available Spring Festival travel rush is a phenomenon in China that population travel intensively surges in a short time around Chinese Spring Festival. This phenomenon, which is a special one in the urbanization process of China, brings a large traffic burden and various kinds of social problems, thereby causing widespread public concern. This study investigates the spatial-temporal characteristics of Spring Festival travel rush in 2015 through time series analysis and complex network analysis based on multisource big travel data derived from Baidu, Tencent, and Qihoo. The main results are as follows: First, big travel data of Baidu and Tencent obtained from location-based services might be more accurate and scientific than that of Qihoo. Second, two travel peaks appeared at five days before and six days after the Spring Festival, respectively, and the travel valley appeared on the Spring Festival. The Spring Festival travel network at the provincial scale did not have small-world and scale-free characteristics. Instead, the travel network showed a multicenter characteristic and a significant geographic clustering characteristic. Moreover, some travel path chains played a leading role in the network. Third, economic and social factors had more influence on the travel network than geographical location factors. The problem of Spring Festival travel rush will not be effectively improved in a short time because of the unbalanced urban-rural development and the unbalanced regional development. However, the development of the modern high-speed transport system and the modern information and communication technology can alleviate problems brought by Spring Festival travel rush. We suggest that a unified real-time traffic platform for Spring Festival travel rush should be established through the government's integration of mobile big data and the official authority data of the transportation department.

  5. Quantized average consensus with delay

    NARCIS (Netherlands)

    Jafarian, Matin; De Persis, Claudio

    2012-01-01

    Average consensus problem is a special case of cooperative control in which the agents of the network asymptotically converge to the average state (i.e., position) of the network by transferring information via a communication topology. One of the issues of the large scale networks is the cost of co

  6. The travel-related carbon dioxide emissions of atmospheric researchers

    Directory of Open Access Journals (Sweden)

    A. Stohl

    2008-04-01

    Full Text Available Most atmospheric scientists agree that greenhouse gas emissions have already caused significant changes to the global climate system and that these changes will accelerate in the near future. At the same time, atmospheric scientists who – like other scientists – rely on international collaboration and information exchange travel a lot and, thereby, cause substantial emissions of carbon dioxide (CO2. In this paper, the CO2 emissions of the employees working at an atmospheric research institute (the Norwegian Institute for Air Research, NILU caused by all types of business travel (conference visits, workshops, field campaigns, instrument maintainance, etc. were calculated for the years 2005–2007. It is estimated that more than 90% of the emissions were caused by air travel, 3% by ground travel and 5% by hotel usage. The travel-related annual emissions were between 1.9 and 2.4 t CO2 per employee or between 3.9 and 5.5 t CO2 per scientist. For comparison, the total annual per capita CO2 emissions are 4.5 t worldwide, 1.2 t for India, 3.8 t for China, 5.9 t for Sweden and 19.1 t for Norway. The travel-related CO2 emissions of a NILU scientist, occurring in 24 days of a year on average, exceed the global average annual per capita emission. Norway's per-capita CO2 emissions are among the highest in the world, mostly because of the emissions from the oil industry. If the emissions per NILU scientist derived in this paper are taken as representative for the average Norwegian researcher, travel by Norwegian scientists would nevertheless account for a substantial 0.2% of Norway's total CO2 emissions. Since most of the travel-related emissions are due to air travel, water vapor emissions, ozone production and contrail formation further increase the relative importance of NILU's travel in terms of radiative forcing.

  7. Travel Writing on the Edge: An Intermedial Approach to Travel Books and Travel Blogs

    Directory of Open Access Journals (Sweden)

    Calzati Stefano

    2015-08-01

    Full Text Available After discussing the limits and potentialities of the definitions of travel writing proposed by Paul Fussell (1980. Patrick Holland and Graham Huggan (1998 and Jan Borm (2004, the article presents a characterization of travel writing both as a genre with a precise rhetorical status, as well as a praxis of knoivledge, which derives from the interplay between travelling and writing. Building on this, a comparison between two Italian travel books and two Italian travel blogs about China is proposed. Specifically, by considering these texts as “intermedial transpositions” (Wolf 2008 that realize the same generic and epistemological matrix (i.e. travel writing, a Multimodal Critical Discourse Analysis (MCDA is conducted in order to assess: 1 how the book and the blog, as different medial formats, interpret the rhetorical features of the travel writing genre: and 2 to what extent the gnoseological and cross-cultural potentials of travel writing, as a praxis of knowledge, is affected by the process of transposition.

  8. 2001 New York State NHTS: Travel Patterns of Special Populations

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Patricia S [ORNL; Reuscher, Tim [ORNL

    2010-03-01

    Policymakers rely on transportation statistics, including data on personal travel behavior, to formulate strategic transportation policies, and to improve the safety and efficiency of the U.S. transportation system. Data on personal travel trends are needed to examine the reliability, efficiency, capacity, and flexibility of the Nation's transportation system to meet current demands and accommodate future demands; to assess the feasibility and efficiency of alternative congestion-alleviating technologies (e.g., high-speed rail, magnetically levitated trains, intelligent vehicle and highway systems); to evaluate the merits of alternative transportation investment programs; and to assess the energy-use and air-quality impacts of various policies. To address these data needs, the U.S. Department of Transportation (USDOT) initiated an effort in 1969 to collect detailed data on personal travel. The 1969 survey was the first Nationwide Personal Transportation Survey (NPTS). The survey was conducted again in 1977, 1983, 1990, 1995, and 2001. Data on daily travel were collected in 1969, 1977, 1983, 1990 and 1995. Longer-distance travel was collected in 1977 and 1995. The 2001 National Household Travel Survey (NHTS) collected both daily and longer-distance trips in one survey. The 2001 survey was sponsored by three USDOT agencies: Federal Highway Administration (FHWA), Bureau of Transportation Statistics (BTS), and National Highway Traffic Safety Administration (NHTSA). The primary objective of the survey was to collect trip-based data on the nature and characteristics of personal travel so that the relationships between the characteristics of personal travel and the demographics of the traveler can be established. Commercial and institutional travel was not part of the survey. New York State participated in the 2001 NHTS by procuring additional 12,000 sample households. These additional sample households allowed New York State to address transportation planning issues

  9. Prediction of Target Travel During Missile Time of Flight. A Computer Simulation

    Science.gov (United States)

    1978-06-01

    limited , but increases with practice. Although both experiments measured subjects’ ability to predict future target travel, results from the first...18 17. SD of Decision Time As a Funcion of Target Speed and Relative Gap Size ....... .............................. 19 18. Mean Decision...speed were varied within the limits described in Table IC (Appendix C). In the Gap program, time of flight (TF), target speed, and re’ ,dp size were

  10. 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...

  11. Exact near-wall traveling waves of plane Poiseuille flow

    Science.gov (United States)

    Gibson, John; Brand, Evan

    2013-11-01

    We present several spatially-localized equilibrium and traveling-wave solutions of plane Couette and plane Poiseuille flow. The solutions consist of highly concentrated and spanwise-localized alternating streamwise rolls, centered over low-speed streamwise streaks and flanked on either side by high-speed streaks. For large Reynolds numbers the solutions develop critical layers that are concentrated at isolated points on the critical surface u = c . For several traveling-wave solutions of plane Poiseuille flow, the rolls are concentrated near one wall, producing streaks near the wall and larger reduction of the bulk flow in the core. These solutions form particularly isolated and elemental versions of near-wall coherent structures in shear flows and capture, as precise time-independent solutions of Navier-Stokes, the process by which near-wall rolls exchange momentum between the wall and core regions and thereby increase drag.

  12. Gaussian moving averages and semimartingales

    DEFF Research Database (Denmark)

    Basse-O'Connor, Andreas

    2008-01-01

    In the present paper we study moving averages (also known as stochastic convolutions) driven by a Wiener process and with a deterministic kernel. Necessary and sufficient conditions on the kernel are provided for the moving average to be a semimartingale in its natural filtration. Our results...... are constructive - meaning that they provide a simple method to obtain kernels for which the moving average is a semimartingale or a Wiener process. Several examples are considered. In the last part of the paper we study general Gaussian processes with stationary increments. We provide necessary and sufficient...

  13. Uniqueness and stability of traveling waves for cellular neural networks with multiple delays

    Science.gov (United States)

    Yu, Zhi-Xian; Mei, Ming

    2016-01-01

    In this paper, we investigate the properties of traveling waves to a class of lattice differential equations for cellular neural networks with multiple delays. Following the previous study [38] on the existence of the traveling waves, here we focus on the uniqueness and the stability of these traveling waves. First of all, by establishing the a priori asymptotic behavior of traveling waves and applying Ikehara's theorem, we prove the uniqueness (up to translation) of traveling waves ϕ (n - ct) with c ≤c* for the cellular neural networks with multiple delays, where c* < 0 is the critical wave speed. Then, by the weighted energy method together with the squeezing technique, we further show the global stability of all non-critical traveling waves for this model, that is, for all monotone waves with the speed c traveling waves, when the initial perturbations around the monotone traveling waves decay exponentially at far fields, but can be arbitrarily large in other locations.

  14. Last-Minute Travel Application

    OpenAIRE

    Hubner, Andre; Lenz, Mario; Borch, Roman; Posthoff, Michael

    2000-01-01

    In this article, we present a last-minute travel application as part of a complete virtual travel agency. Each year, a significant amount of tour packages are sold as last minute tours in Germany. It is impossible for a travel agent to keep track of all the offered tour packages. Electronic-commerce applications might present the best possible tour package for a specific customer request. Traditional database-driven applications, as used by most of the tour operators, are not sufficient enoug...

  15. On the impossibility of superluminal travel: the warp drive lesson

    CERN Document Server

    Barceló, Carlos; Liberati, Stefano

    2010-01-01

    The question of whether it is possible or not to surpass the speed of light is already centennial. The special theory of relativity took the existence of a speed limit as a principle, the light postulate, which has proven to be enormously predictive. Here we discuss some of its twists and turns when general relativity and quantum mechanics come into play. In particular, we discuss one of the most interesting proposals for faster than light travel: warp drives. Even if one succeeded in creating such spacetime structures, it would be still necessary to check whether they would survive to the switching on of quantum matter effects. Here, we show that the quantum back-reaction to warp-drive geometries, created out of an initially flat spacetime, inevitably lead to their destabilization whenever superluminal speeds are attained. We close this investigation speculating the possible significance of this further success of the speed of light postulate.

  16. A novel sandwich-type traveling wave piezoelectric tracked mobile system.

    Science.gov (United States)

    Wang, Liang; Shu, Chengyou; Zhang, Quan; Jin, Jiamei

    2017-03-01

    In this paper, a novel sandwich-type traveling wave piezoelectric tracked mobile system was proposed, designed, fabricated and experimentally investigated. The proposed system exhibits the advantages of simple structure, high mechanical integration, lack of electromagnetic interference, and lack of lubrication requirement, and hence shows potential application to robotic rovers for planetary exploration. The tracked mobile system is comprised of a sandwich actuating mechanism and a metal track. The actuating mechanism includes a sandwich piezoelectric transducer and two annular parts symmetrically placed at either end of the transducer, while the metal track is tensioned along the outer surfaces of the annular parts. Traveling waves with the same rotational direction are generated in the two annular parts, producing the microscopic elliptical motions of the surface particles on the annular parts. In this situation, if the pre-load is applied properly, the metal track can be driven by friction force to achieve bidirectional movement. At first, the finite element method was adopted to conduct the modal analysis and harmonic response analysis of the actuating mechanism, and the vibration characteristics were measured to confirm the operating principle. Then the optimal driving frequency of the system prototype, namely 35.1kHz, was measured by frequency sensitivity experiments. At last, the mechanical motion characteristics of the prototype were investigated experimentally. The results show that the average motion speeds of the prototype in dual directions were as 72mm/s and 61.5mm/s under the excitation voltage of 500VRMS, respectively. The optimal loading weights of the prototype in bi-directions were 0.32kg and 0.24kg with a maximum speed of 59.5mm/s and 61.67mm/s at the driving voltage of 300VRMS, respectively.

  17. Fault location method for transmission line based on traveling waves

    Institute of Scientific and Technical Information of China (English)

    ZHENG Na; ZHAO Yulin

    2007-01-01

    The single phase grounding fault location is the focus which researchers pay attention to and study in power system. The accurate fault location can lighten the patrolling burden, and enhance the reliability of the power network. It adopts A/D which has high speed, and uses TMS320VC5402 DSP chip as the system core. This paper presented theory of operation based on traveling waves and achieved software and hardware in detail.

  18. Momentum harvesting techniques for solar system travel

    Science.gov (United States)

    Willoughby, Alan J.

    1991-01-01

    Astronomers are lately estimating there are 400,000 earth visiting asteroids larger than 100 meters in diameter. These asteroids are uniquely accessible sources of building materials, propellants, oxygen, water, and minerals. They also constitute a huge momentum reserve, potentially usable for travel throughout the solar system. To use this momentum, these stealthy objects must be tracked and the ability to extract the desired momentum obtained. Momentum harvesting by momentum transfer from asteroid to spacecraft, and by using the momentum of the extraterrestrial material to help deliver itself to its destination is discussed. The purpose is neither to quantify nor justify the momentum exchange processes, but to stimulate collective imaginations with some intriguing possibilities which emerge when momentum as well as material is considered. A net and tether concept is the suggested means of asteroid capture, the basic momentum exchange process. The energy damping characteristics of the tether determines the velocity mismatch that can be tolerated, and hence the amount of momentum that can be harvested per capture. As the tether plays out of its reel, drag on the tether steadily accelerates the spacecraft and dilutes, in time, the would-be collision. A variety of concepts for riding and using asteroids after capture are introduced. The hitchhiker uses momentum transfer only. The beachcomber, the caveman, the swinger, the prospector, and the rock wrecker also take advantage of raw asteroid materials. The chemist and the hijacker go further, they process the asteroid into propellants. Or, an asteroid railway system could be constructed with each hijacked asteroid becoming a scheduled train. Travelers could board this space railway system assured that water, oxygen propellants, and shielding await them. Austere space travel could give way to comforts, with a speed and economy impossible without nature's gift of earth visiting asteroids.

  19. 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...

  20. Mosquito Bite Prevention For Travelers

    Science.gov (United States)

    ... and parasites that can cause diseases like chikungunya, dengue, Zika, and malaria. If you are traveling to an area where malaria is found, talk to your healthcare provider about malaria prevention medication that may be available. Protect yourself and ...

  1. 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.)...

  2. Travelers' Health: Viral Hemorrhagic Fevers

    Science.gov (United States)

    ... Climates Humanitarian Aid Workers Humanitarian Aid Workers in Ecuador Insurance International Adoption Jet Lag Last-Minute Travel ... Landry ML, Warnock DW, editors. Manual of Clinical Microbiology. 10th ed. Washington, DC: ASM Press; 2011. p. ...

  3. 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...

  4. 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.

  5. Speed of information diffusion within fund families

    OpenAIRE

    Cici, Gjergji; Jaspersen, Stefan; KEMPF Alexander

    2015-01-01

    We document that the speed of information dissemination within mutual fund families positively affects the performance of member funds. This suggests that the resulting benefits of higher information precision far outweigh free-riding costs associated with fast internal dissemination. The performance effect intensifies when information travels across managers from different rather than same styles. This is consistent with fast information diffusion aggregating complementary insights that shar...

  6. On Hamiltonians Generating Optimal-Speed Evolutions

    OpenAIRE

    2008-01-01

    We present a simple derivation of the formula for the Hamiltonian operator(s) that achieve the fastest possible unitary evolution between given initial and final states. We discuss how this formula is modified in pseudo-Hermitian quantum mechanics and provide an explicit expression for the most general optimal-speed quasi-Hermitian Hamiltonian. Our approach allows for an explicit description of the metric- (inner product-) dependence of the lower bound on the travel time and the universality ...

  7. Sequentially pulsed traveling wave accelerator

    Science.gov (United States)

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    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.

  8. A model of multidestination travel

    DEFF Research Database (Denmark)

    Morisugi, H.; Tussyadiah, Iis; Kono, T.

    2006-01-01

    , specifically address the choice of a single destination. This article is intended to explain multiple destination choice using Lancaster's characteristics model and a discussion of model implications of some marketing strategies for destinations as well as for tour operators. The model developed herein...... explains that packages of multiple destinations can create preferable combinations of characteristics for certain travelers. Furthermore, the model provides useful strategies for tour operators in combining destinations into a travel menu or package. © 2006 Sage Publications....

  9. 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).

  10. Vocal attractiveness increases by averaging.

    Science.gov (United States)

    Bruckert, Laetitia; Bestelmeyer, Patricia; Latinus, Marianne; Rouger, Julien; Charest, Ian; Rousselet, Guillaume A; Kawahara, Hideki; Belin, Pascal

    2010-01-26

    Vocal attractiveness has a profound influence on listeners-a bias known as the "what sounds beautiful is good" vocal attractiveness stereotype [1]-with tangible impact on a voice owner's success at mating, job applications, and/or elections. The prevailing view holds that attractive voices are those that signal desirable attributes in a potential mate [2-4]-e.g., lower pitch in male voices. However, this account does not explain our preferences in more general social contexts in which voices of both genders are evaluated. Here we show that averaging voices via auditory morphing [5] results in more attractive voices, irrespective of the speaker's or listener's gender. Moreover, we show that this phenomenon is largely explained by two independent by-products of averaging: a smoother voice texture (reduced aperiodicities) and a greater similarity in pitch and timbre with the average of all voices (reduced "distance to mean"). These results provide the first evidence for a phenomenon of vocal attractiveness increases by averaging, analogous to a well-established effect of facial averaging [6, 7]. They highlight prototype-based coding [8] as a central feature of voice perception, emphasizing the similarity in the mechanisms of face and voice perception.

  11. The effect of travel restrictions on the spread of a highly contagious disease in Sweden

    CERN Document Server

    Camitz, Martin

    2016-01-01

    Travel restrictions may reduce the spread of a contagious disease that threatens public health. In this study we investigate what effect different levels of travel restrictions may have on the speed and geographical spread of an outbreak of a disease similar to SARS. We use a stochastic simulation model of the Swedish population, calibrated with survey data of travel patterns between municipalities in Sweden collected over three years. We find that a ban on journeys longer than 50 km drastically reduces the speed and the geographical spread of outbreaks, even with when compliance is less than 100%. The result is found to be robust for different rates of inter-municipality transmission intensities. Travel restrictions may therefore be an effective way to mitigate the effect of a future outbreak.

  12. The Role of the Harmonic Vector Average in Motion Integration

    Directory of Open Access Journals (Sweden)

    Alan eJohnston

    2013-10-01

    Full Text Available The local speeds of object contours vary systematically with the cosine of the angle between the normal component of the local velocity and the global object motion direction. An array of Gabor elements whose speed changes with local spatial orientation in accordance with this pattern can appear to move as a single surface. The apparent direction of motion of plaids and Gabor arrays has variously been proposed to result from feature tracking, vector addition and vector averaging in addition to the geometrically correct global velocity as indicated by the intersection of constraints (IOC solution. Here a new combination rule, the harmonic vector average (HVA, is introduced, as well as a new algorithm for computing the IOC solution. The vector sum can be discounted as an integration strategy as it increases with the number of elements. The vector average over local vectors that vary in direction always provides an underestimate of the true global speed. The harmonic vector average however provides the correct global speed and direction for an unbiased sample of local velocities with respect to the global motion direction, as is the case for a simple closed contour. The HVA over biased samples provides an aggregate velocity estimate that can still be combined through an IOC computation to give an accurate estimate of the global velocity, which is not true of the vector average. Psychophysical results for type II Gabor arrays show perceived direction and speed falls close to the intersection of constraints direction for Gabor arrays having a wide range of orientations but the IOC prediction fails as the mean orientation shifts away from the global motion direction and the orientation range narrows. In this case perceived velocity generally defaults to the harmonic vector average.

  13. Estimating pedestrian speed using aggregated literature data

    Science.gov (United States)

    Bosina, Ernst; Weidmann, Ulrich

    2017-02-01

    Since about 80 years, human walking speed has been measured for different purposes. The comparability of the results of these measurements is low, as the walking speed is influenced by a vast amount of parameters and no standardised measurement conditions exist. This work describes the most important factors influencing walking speed based on existing literature and estimates their impact. For this purpose, all walking speed measurements available in the literature were collected and reviewed. Using this data, the parameter values for different influences were computed and grouped according to their strength, which enables to determine the most important measurement parameters in future walking speed experiments. In addition, standardised measurement conditions are proposed which would provide a baseline for future studies and thus enhance their scientific value. For each of these conditions average walking speeds are calculated and the significance of the walking speed differences was determined.

  14. Simulating hydroplaning of submarine landslides by quasi 3D depth averaged finite element method

    Science.gov (United States)

    De Blasio, Fabio; Battista Crosta, Giovanni

    2014-05-01

    G.B. Crosta, H. J. Chen, and F.V. De Blasio Dept. Of Earth and Environmental Sciences, Università degli Studi di Milano Bicocca, Milano, Italy Klohn Crippen Berger, Calgary, Canada Subaqueous debris flows/submarine landslides, both in the open ocean as well as in fresh waters, exhibit extremely high mobility, quantified by a ratio between vertical to horizontal displacement of the order 0.01 or even much less. It is possible to simulate subaqueous debris flows with small-scale experiments along a flume or a pool using a cohesive mixture of clay and sand. The results have shown a strong enhancement of runout and velocity compared to the case in which the same debris flow travels without water, and have indicated hydroplaning as a possible explanation (Mohrig et al. 1998). Hydroplaning is started when the snout of the debris flow travels sufficiently fast. This generates lift forces on the front of the debris flow exceeding the self-weight of the sediment, which so begins to travel detached from the bed, literally hovering instead of flowing. Clearly, the resistance to flow plummets because drag stress against water is much smaller than the shear strength of the material. The consequence is a dramatic increase of the debris flow speed and runout. Does the process occur also for subaqueous landslides and debris flows in the ocean, something twelve orders of magnitude larger than the experimental ones? Obviously, no experiment will ever be capable to replicate this size, one needs to rely on numerical simulations. Results extending a depth-integrated numerical model for debris flows (Imran et al., 2001) indicate that hydroplaning is possible (De Blasio et al., 2004), but more should be done especially with alternative numerical methodologies. In this work, finite element methods are used to simulate hydroplaning using the code MADflow (Chen, 2014) adopting a depth averaged solution. We ran some simulations on the small scale of the laboratory experiments, and secondly

  15. Averaged Electroencephalic Audiometry in Infants

    Science.gov (United States)

    Lentz, William E.; McCandless, Geary A.

    1971-01-01

    Normal, preterm, and high-risk infants were tested at 1, 3, 6, and 12 months of age using averaged electroencephalic audiometry (AEA) to determine the usefulness of AEA as a measurement technique for assessing auditory acuity in infants, and to delineate some of the procedural and technical problems often encountered. (KW)

  16. Ergodic averages via dominating processes

    DEFF Research Database (Denmark)

    Møller, Jesper; Mengersen, Kerrie

    2006-01-01

    We show how the mean of a monotone function (defined on a state space equipped with a partial ordering) can be estimated, using ergodic averages calculated from upper and lower dominating processes of a stationary irreducible Markov chain. In particular, we do not need to simulate the stationary ...

  17. Travel Time Estimation and Prediction using Mobile Phones: A Cost Effective Method for Developing Countries

    Directory of Open Access Journals (Sweden)

    Satyakumar, M.

    2014-01-01

    Full Text Available Conventional data collection methods lack real time information and involve excessive cost of installation and maintenance. A real-time, low cost travel time data collection system can be developed using mobile phones. This project examines the use of mobile phones for travel time prediction of public transit vehicles and develops a dynamic travel time prediction model. Personnel were employed in public transit vehicles with mobile phones and these mobile phones were tracked continuously. Space information of the mobile phones represents the position of the buses and movement pattern of these mobile phones in turn represents the movement pattern of the public buses. The starting and arrival time at sections obtained from the cellular database were used to get the travel time and speed. Results obtained were statistically significant and it shows that use of mobile phone for travel time data collection is a low cost data collection technique for Indian cities.

  18. Practical advice for perioperative travel nurses.

    Science.gov (United States)

    Brumley, Cindy L

    2002-10-01

    Travel nursing presents unique opportunities that permanent employees may never experience. Today's nursing shortage allows travel nurses to fill temporary staff positions while experiencing the sights, culture, and cuisine of a location of their choosing. This creates a beneficial situation for travel nurses, hospitals, travel companies, and, ultimately, patients. Knowledgeable, flexible nurses and traveler-friendly hospitals can extend contracts if mutually agreeable, thus prolonging the benefits. Before beginning the adventure, however, travelers must have realistic expectations. Many disappointed travelers may have been more successful had they done better research.

  19. 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....

  20. Choosing between travel agencies and the Internet

    OpenAIRE

    2015-01-01

    M.A. (Tourism and Hospitality Management) Travel agents have been traditionally seen as the key intermediary between suppliers of travel services and the traveller. Developments in the field of information technology offer consumers an alternative to booking via a travel agent - the option to plan and arrange holidays online. Due to the ever developing nature of technology, travellers have the luxury of a multitude of choices in their everyday life - particularly so in making decisions reg...

  1. Chaotic operation and chaos control of travelling wave ultrasonic motor.

    Science.gov (United States)

    Shi, Jingzhuo; Zhao, Fujie; Shen, Xiaoxi; Wang, Xiaojie

    2013-08-01

    The travelling wave ultrasonic motor, which is a nonlinear dynamic system, has complex chaotic phenomenon with some certain choices of system parameters and external inputs, and its chaotic characteristics have not been studied until now. In this paper, the preliminary study of the chaos phenomenon in ultrasonic motor driving system has been done. The experiment of speed closed-loop control is designed to obtain several groups of time sampling data sequence of the amplitude of driving voltage, and phase-space reconstruction is used to analyze the chaos characteristics of these time sequences. The largest Lyapunov index is calculated and the result is positive, which shows that the travelling wave ultrasonic motor has chaotic characteristics in a certain working condition Then, the nonlinear characteristics of travelling wave ultrasonic motor are analyzed which includes Lyapunov exponent map, the bifurcation diagram and the locus of voltage relative to speed based on the nonlinear chaos model of a travelling wave ultrasonic motor. After that, two kinds of adaptive delay feedback controllers are designed in this paper to control and suppress chaos in USM speed control system. Simulation results show that the method can control unstable periodic orbits, suppress chaos in USM control system. Proportion-delayed feedback controller was designed following and arithmetic of fuzzy logic was used to adaptively adjust the delay time online. Simulation results show that this method could fast and effectively change the chaos movement into periodic or fixed-point movement and make the system enter into stable state from chaos state. Finally the chaos behavior was controlled.

  2. 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

  3. Poliomyelitis--prevention in travellers.

    Science.gov (United States)

    Mayer, Cora A; Neilson, Amy A

    2010-03-01

    This article is the second in a series providing a summary of prevention strategies and vaccination for infections that may be acquired by travellers. The series aims to provide practical strategies to assist general practitioners in giving travel advice, as a synthesis of multiple information sources which must otherwise be consulted. Poliomyelitis is a potentially fatal viral illness, which may cause acute flaccid paralysis and permanent central nervous system damage. Ongoing global efforts to eradicate poliomyelitis have been under way since 1988. Travellers are at risk of infection in countries with endemic wild poliomyelitis virus or imported cases, and can spread the infection to areas where poliomyelitis has been eradicated. While all adults should be immune to poliomyelitis, it is important that at-risk travellers are vaccinated appropriately. Vaccine options and regions currently reporting poliomyelitis are presented from a number of sources, which may facilitate the process of giving travel advice in a general practice setting, although it is also important to seek up-to-date epidemiological information.

  4. 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.

  5. Dependability in Aggregation by Averaging

    CERN Document Server

    Jesus, Paulo; Almeida, Paulo Sérgio

    2010-01-01

    Aggregation is an important building block of modern distributed applications, allowing the determination of meaningful properties (e.g. network size, total storage capacity, average load, majorities, etc.) that are used to direct the execution of the system. However, the majority of the existing aggregation algorithms exhibit relevant dependability issues, when prospecting their use in real application environments. In this paper, we reveal some dependability issues of aggregation algorithms based on iterative averaging techniques, giving some directions to solve them. This class of algorithms is considered robust (when compared to common tree-based approaches), being independent from the used routing topology and providing an aggregation result at all nodes. However, their robustness is strongly challenged and their correctness often compromised, when changing the assumptions of their working environment to more realistic ones. The correctness of this class of algorithms relies on the maintenance of a funda...

  6. High average power supercontinuum sources

    Indian Academy of Sciences (India)

    J C Travers

    2010-11-01

    The physical mechanisms and basic experimental techniques for the creation of high average spectral power supercontinuum sources is briefly reviewed. We focus on the use of high-power ytterbium-doped fibre lasers as pump sources, and the use of highly nonlinear photonic crystal fibres as the nonlinear medium. The most common experimental arrangements are described, including both continuous wave fibre laser systems with over 100 W pump power, and picosecond mode-locked, master oscillator power fibre amplifier systems, with over 10 kW peak pump power. These systems can produce broadband supercontinua with over 50 and 1 mW/nm average spectral power, respectively. Techniques for numerical modelling of the supercontinuum sources are presented and used to illustrate some supercontinuum dynamics. Some recent experimental results are presented.

  7. Measuring Complexity through Average Symmetry

    OpenAIRE

    Alamino, Roberto C.

    2015-01-01

    This work introduces a complexity measure which addresses some conflicting issues between existing ones by using a new principle - measuring the average amount of symmetry broken by an object. It attributes low (although different) complexity to either deterministic or random homogeneous densities and higher complexity to the intermediate cases. This new measure is easily computable, breaks the coarse graining paradigm and can be straightforwardly generalised, including to continuous cases an...

  8. IMPACTS OF LOWER SPEED LIMITS IN SOUTH AUSTRALIA

    Directory of Open Access Journals (Sweden)

    J.E. WOOLLEY

    2002-01-01

    This paper reports on a more holistic assessment of such schemes taking into account factors in addition to speed and crashes including: traffic volume displacement, physical road network characteristics, environmental factors, community ownership and acceptance, enforcement effort and impact on travel times. The research work has included the analysis of extensive traffic data, community surveys and focus groups, the collection of environmental and travel time data from an instrumented probe vehicle and the computer modelling of road networks. The work reported is based on over 10 years of working with a 40km/h lower urban speed limit area in South Australia. The paper expands the notion of using speed and crash outcomes as the only criteria for measuring the success of lower speed limit schemes.

  9. Speed and structure of turbulent fronts in pipe flow

    CERN Document Server

    Song, Baofang; Hof, Björn; Avila, Marc

    2016-01-01

    The dynamics of laminar-turbulent fronts in pipe flow is investigated for Reynolds numbers between Re=1900 and Re=5500 using extensive direct numerical simulations. In this range the flow undergoes a continuous transition from localised puffs to weakly expanding and ultimately to strongly expanding turbulent slugs (Barkley et al. 2015). We here investigate the physical distinction between these two types of slug by analysing time-resolved statistics of their downstream fronts in the frame moving at the bulk turbulent advection speed. While weak fronts travel slower than the bulk turbulent advection speed, implying local relaminarisation, strong fronts travel faster and so feed on the laminar flow ahead. At Re$\\approx$2900 the downstream front speed becomes faster than the advection speed, marking the onset of strong fronts. We argue that large temporal fluctuations of production and dissipation at the laminar-turbulent interface drive the dynamical switches between the two types of front observed up to Re$\\si...

  10. 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.

  11. Existence and qualitative properties of travelling waves for an epidemiological model with mutations

    Science.gov (United States)

    Griette, Quentin; Raoul, Gaël

    2016-05-01

    In this article, we are interested in a non-monotonic system of logistic reaction-diffusion equations. This system of equations models an epidemic where two types of pathogens are competing, and a mutation can change one type into the other with a certain rate. We show the existence of travelling waves with minimal speed, which are usually non-monotonic. Then we provide a description of the shape of those constructed travelling waves, and relate them to some Fisher-KPP fronts with non-minimal speed.

  12. Travel epidemiology: the Saudi perspective.

    Science.gov (United States)

    Memish, Ziad A; Venkatesh, S; Ahmed, Qanta A

    2003-02-01

    The Kingdom of Saudi Arabia occupies four-fifths of the Arabian Peninsula, with a land area of 2 million square kilometres. Saudi Arabia holds a unique position in the Islamic world, as the custodian of the two holiest places of Islam, in Mecca and Medina. Annually, some 2 million Muslims from over 140 countries embark on Hajj. This extraordinary en masse migration is a unique forum for the study of travel epidemiology since the Hajj carries various health risks, both communicable and non-communicable, often on a colossal scale. Non-communicable hazards of the Hajj include stampede and motor vehicle trauma, fire-related burn injuries and accidental hand injury during animal slaughter. Communicable hazards in the form of outbreaks of multiple infectious diseases have been reported repeatedly, during and following the Hajj. Meningococcal meningitis, gastroenteritis, hepatitis A, B and C, and various zoonotic diseases comprise some of the possible infectious hazards at the Hajj. Many of these infectious and non-infectious hazards can be avoided or averted by adopting appropriate prophylactic measures. Physicians and health personnel must be aware of these risks to appropriately educate, immunize and prepare these travellers facing the unique epidemiological challenges of Hajj in an effort to minimize untoward effects. Travel epidemiology related to the Hajj is a new and exciting area, which offers valuable insights to the travel specialist. The sheer scale of numbers affords a rare view of migration medicine in action. As data is continually gathered and both national and international policy making is tailored to vital insights gained through travel epidemiology, the Hajj will be continually safeguarded. Practitioners will gain from findings of travel related epidemiological changes in evolution at the Hajj: the impact of vaccinating policies, infection control policies and public health are afforded a real-world laboratory setting at each annual Hajj, allowing us to

  13. Travelling wave analysis of a mathematical model of glioblastoma growth.

    Science.gov (United States)

    Gerlee, Philip; Nelander, Sven

    2016-06-01

    In this paper we analyse a previously proposed cell-based model of glioblastoma (brain tumour) growth, which is based on the assumption that the cancer cells switch phenotypes between a proliferative and motile state (Gerlee and Nelander, 2012). The dynamics of this model can be described by a system of partial differential equations, which exhibits travelling wave solutions whose wave speed depends crucially on the rates of phenotypic switching. We show that under certain conditions on the model parameters, a closed form expression of the wave speed can be obtained, and using singular perturbation methods we also derive an approximate expression of the wave front shape. These new analytical results agree with simulations of the cell-based model, and importantly show that the inverse relationship between wave front steepness and speed observed for the Fisher equation no longer holds when phenotypic switching is considered.

  14. 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...

  15. 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.

  16. Black Holes: A Traveler's Guide

    Science.gov (United States)

    Pickover, Clifford A.

    1998-03-01

    BLACK HOLES A TRAVELER'S GUIDE Clifford Pickover's inventive and entertaining excursion beyond the curves of space and time. "I've enjoyed Clifford Pickover's earlier books . . . now he has ventured into the exploration of black holes. All would-be tourists are strongly advised to read his traveler's guide." -Arthur C. Clarke. "Many books have been written about black holes, but none surpass this one in arousing emotions of awe and wonder towards the mysterious structure of the universe." -Martin Gardner. "Bucky Fuller thought big. Arthur C. Clarke thinks big, but Cliff Pickover outdoes them both." -Wired. "The book is fun, zany, in-your-face, and refreshingly addictive." -Times Higher Education Supplement.

  17. 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.

  18. Urban Traffic Eco-Driving: Speed Advisory Tracking

    OpenAIRE

    De Nunzio, Giovanni; Canudas De Wit, Carlos; Moulin, Philippe

    2014-01-01

    International audience; The evaluation of the benefits of an Eco-Driving assistance system is carried out in the urban environment in presence of traffic lights. The traffic evolution is modeled macroscopically with the Urban Variable-Length Model in a variable speed limits framework. Under the assumption of equal boundary flows, the vehicles in a road section dispose themselves according to well defined equilibrium conditions which are dependent on the traveling speed in the free-flow part o...

  19. 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...... holidays. The majority of international travel is within Europe, but increasing travelling outside Europe is furthermore emerging. In total these trends implies that Danes do travel more and longer, which is related to a general increase in travelling within the whole population, but also more holidays per...

  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......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 climate burden from long overseas distances is especially high even though only few travel overseas. The travel activity is furthermore increasing much more for long distances than for European destinations. Domestic travel activity with overnight stay is nearly stagnating. The study furthermore shows...

  1. Diffusive behavior of a greedy traveling salesman

    Science.gov (United States)

    Lipowski, Adam; Lipowska, Dorota

    2011-06-01

    Using Monte Carlo simulations we examine the diffusive properties of the greedy algorithm in the d-dimensional traveling salesman problem. Our results show that for d=3 and 4 the average squared distance from the origin is proportional to the number of steps t. In the d=2 case such a scaling is modified with some logarithmic corrections, which might suggest that d=2 is the critical dimension of the problem. The distribution of lengths also shows marked differences between d=2 and d>2 versions. A simple strategy adopted by the salesman might resemble strategies chosen by some foraging and hunting animals, for which anomalous diffusive behavior has recently been reported and interpreted in terms of Lévy flights. Our results suggest that broad and Lévy-like distributions in such systems might appear due to dimension-dependent properties of a search space.

  2. High speed data converters

    CERN Document Server

    Ali, Ahmed MA

    2016-01-01

    This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.

  3. Measures for speed management.

    NARCIS (Netherlands)

    2009-01-01

    Measures for speed management are essential for limiting the negative effects of driving too fast and at inappropriate speeds. To begin with, safe and credible speed limits need to be determined. Dynamic and variable speed limits that take into account the current circumstances, such as weather cond

  4. Visual processing speed in old age

    DEFF Research Database (Denmark)

    Habekost, Thomas; vogel, asmus; Rostrup, Egill;

    2013-01-01

    of the speed of a particular psychological process that are not confounded by the speed of other processes. We used Bundesen's (1990) Theory of Visual Attention (TVA) to obtain specific estimates of processing speed in the visual system controlled for the influence of response latency and individual variations......Habekost, T., Vogel, A., Rostrup, E., Bundesen, C., Kyllingsbaek, S., Garde, E., Ryberg, C. & Waldemar, G. (2012). Visual processing speed in old age. Scandinavian Journal of Psychology. Mental speed is a common concept in theories of cognitive aging, but it is difficult to get measures...... of the perception threshold. A total of 33 non-demented old people (69-87 years) were tested for the ability to recognize briefly presented letters. Performance was analyzed by the TVA model. Visual processing speed decreased approximately linearly with age and was on average halved from 70 to 85 years. Less...

  5. Time-distance helioseismology: A new averaging scheme for measuring flow vorticity

    CERN Document Server

    Langfellner, Jan; Birch, Aaron C

    2014-01-01

    Time-distance helioseismology provides information about vector flows in the near-surface layers of the Sun by measuring wave travel times between points on the solar surface. Specific spatial averages of travel times have been proposed for distinguishing between flows in the east-west and north-south directions and measuring the horizontal divergence of the flows. No specific measurement technique has, however, been developed to measure flow vorticity. Here we propose a new measurement technique tailored to measuring the vertical component of vorticity. Fluid vorticity is a fundamental property of solar convection zone dynamics and of rotating turbulent convection in particular. The method consists of measuring the travel time of waves along a closed contour on the solar surface in order to approximate the circulation of the flow along this contour. Vertical vorticity is related to the difference between clockwise and counter-clockwise travel times. We applied the method to characterize the vortical motions ...

  6. 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...

  7. 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.

  8. 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…

  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. CITM: Asian's Largest Travel Show

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Jointly hosted by China National Tourism Administration, Yunnan Provincial People's Government and General Administration of Civil Aviation of China, China International Travel Mart (CITM) is a major step to develop inbound tourism, to increase tourism receipts in foreign exchanges, and to enhance the international status of China's tourism industry.

  11. 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...

  12. 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

  13. A Travel To Hong Kong

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    This summer holiday,I had travelled to Hong Kong with many other students.We went to Hong Kong by plane.Hong Kong is very small,but there are many people living there. In Hong Kong,all of the buildings are very tall.There are lots of shops there and

  14. Travel to the Rio Olympics

    Centers for Disease Control (CDC) Podcasts

    2016-07-21

    Learn how to stay healthy and safe when travelling to the 2016 Olympic Games in Rio de Janeiro.  Created: 7/21/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 7/21/2016.

  15. Bonaparte's Gull - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  16. Laughing Gull - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  17. Leach's Storm Petrel - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  18. Wilson's Storm Petrel - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  19. Surf Scoter - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  20. Cory's Shearwater - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  1. Great Shearwater - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  2. Roseate Tern - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  3. Black Scoter - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  4. Red Phalarope - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  5. Herring Gull - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  6. Common Eider - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  7. Common Loon - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  8. Northern Gannet - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  9. Common Tern - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  10. Pomarine Jaeger - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  11. Sooty Shearwater - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  12. Northern Fulmar - Avian Average Annual Abundance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data represent predicted number of individuals of each listed seabird species per standardized survey segment (15 minute travel time at 10 knots = approx. 2.5...

  13. Exploring THz band for high speed wireless communications

    DEFF Research Database (Denmark)

    Yu, Xianbin; Zhang, Hangkai; Jia, Shi;

    2016-01-01

    We overview recent trend in developing high speed wireless communication systems by exploring large bandwidth available in the THz band, and we also present our recent experimental achievements on 400 GHz wireless transmission with a data rate of up to 60 Gbit/s by using a uni-travelling carrier...

  14. Shear wave speeds at the base of the mantle

    NARCIS (Netherlands)

    Castle, John C.; Hilst, R.D. van der; Creager, K.C.; Winchester, John P.

    2006-01-01

    We inverted 4864 ScS-S and 1671 S(diff)-SKS residual travel times for shear wave speed anomalies at the base of the Earth's mantle. We applied ellipticity corrections, accounted for mantle structure outside of the basal layer using mantle tomography models, and employed finite size sensitivity kerne

  15. Radiation Risk Projections for Space Travel

    Science.gov (United States)

    Cucinotta, Francis

    2003-01-01

    Space travelers are exposed to solar and galactic cosmic rays comprised of protons and heavy ions moving with velocities close to the speed of light. Cosmic ray heavy ions are known to produce more severe types of biomolecular damage in comparison to terrestrial forms of radiation, however the relationship between such damage and disease has not been fully elucidated. On Earth, we are protected from cosmic rays by atmospheric and magnetic shielding, and only the remnants of cosmic rays in the form of ground level muons and other secondary radiations are present. Because human epidemiology data is lacking for cosmic rays, risk projection must rely on theoretical understanding and data from experimental models exposed to space radiation using charged particle accelerators to simulate space radiation. Although the risks of cancer and other late effects from cosmic rays are currently believed to present a severe challenge to space travel, this challenge is centered on our lack of confidence in risk projections methodologies. We review biophysics and radiobiology data on the effects of the cosmic ray heavy ions, and the current methods used to project radiation risks . Cancer risk projections are described as a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. Risk projections for space travel are described using Monte-Carlo sampling from subjective error di stributions that represent the lack of knowledge in each factor that contributes to the projection model in order to quantify the overall uncertainty in risk projections. This analysis is applied to space mi ssion scenarios including lunar colony, deep space outpost, and a Mars mission. Results suggest that the number of days in space where cancer mortality risks can be assured at a 95% confidence level to be below the maximum acceptable risk for radi ation workers on Earth or the International Space Station is only on the order

  16. Improved road traffic emission inventories by adding mean speed distributions

    NARCIS (Netherlands)

    Smit, R.; Poelman, M.; Schrijver, J.

    2008-01-01

    Does consideration of average speed distributions on roads-as compared to single mean speed-lead to different results in emission modelling of large road networks? To address this question, a post-processing method is developed to predict mean speed distributions using available traffic data from a

  17. A rational approach to the traveling wave phenomenon.

    Science.gov (United States)

    Tonndorf, J

    1979-01-01

    To aid comprehension of cochlear traveling waves, the present article will explain this complex phenomenon in terms of its underlying principles: (1) fluid mechanics, with particular reference to a tangible, analogous event, wave transformation on sloping beaches; (2) the central role of the cochlear stiffness gradient with respect to an energy exchange between travel speed and amplitude of cochlear waves, low pass filter action with distance, and impedance matching for the benefit of wave progression; (3) spatial domain and frequency domain considerations; (4) the solution to the classic dilemma between cochlear tuning and damping; and (5) the task of the helicotrema. I will not discuss the ultimate mechanical stimulation of cochlear hair cells that is mediated by shearing interactions between the tectorial membrane and the organ proper.

  18. Short-Term Speed Prediction Using Remote Microwave Sensor Data: Machine Learning versus Statistical Model

    Directory of Open Access Journals (Sweden)

    Han Jiang

    2016-01-01

    Full Text Available Recently, a number of short-term speed prediction approaches have been developed, in which most algorithms are based on machine learning and statistical theory. This paper examined the multistep ahead prediction performance of eight different models using the 2-minute travel speed data collected from three Remote Traffic Microwave Sensors located on a southbound segment of 4th ring road in Beijing City. Specifically, we consider five machine learning methods: Back Propagation Neural Network (BPNN, nonlinear autoregressive model with exogenous inputs neural network (NARXNN, support vector machine with radial basis function as kernel function (SVM-RBF, Support Vector Machine with Linear Function (SVM-LIN, and Multilinear Regression (MLR as candidate. Three statistical models are also selected: Autoregressive Integrated Moving Average (ARIMA, Vector Autoregression (VAR, and Space-Time (ST model. From the prediction results, we find the following meaningful results: (1 the prediction accuracy of speed deteriorates as the prediction time steps increase for all models; (2 the BPNN, NARXNN, and SVM-RBF can clearly outperform two traditional statistical models: ARIMA and VAR; (3 the prediction performance of ANN is superior to that of SVM and MLR; (4 as time step increases, the ST model can consistently provide the lowest MAE comparing with ARIMA and VAR.

  19. 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.

  20. Travel Recommendations for the Nursing Mother

    Science.gov (United States)

    ... Address What's this? Submit What's this? Submit Button Breastfeeding Information for Families Breastfeeding Hotline The HHS Office ... State and Local Programs Travel Recommendations for the Nursing Mother Recommend on Facebook Tweet Share Compartir Travel ...

  1. 49 CFR 229.55 - Piston travel.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.55 Piston travel. (a) Brake cylinder piston travel shall be sufficient to provide brake shoe clearance...

  2. Air travel, life-style, energy use and environmental impact

    Energy Technology Data Exchange (ETDEWEB)

    Krueger Nielsen, S.

    2001-09-01

    shown in this report, the current level of passenger air travel per capita in Europe may be considered within environmentally sustainable limits by the middle of this century provided that the current average greenhouse gas intensity of air travel is halved by then. Conversely, for exsample, an average American citizen today travels almost three times as much by air as an average European, thereby already exceeding the sustainabillity target for the World's citizens on average by the middle of this century that is proposed in this report. (EHS)

  3. A travelers' clinic in an academic setting.

    OpenAIRE

    Cordes, D H; Baca, C T; Grant, K. J.

    1989-01-01

    The Department of Family and Community Medicine at the University of Arizona has operated a travelers' clinic since 1983, staffed primarily by faculty and residents from the sections of preventive medicine, occupational medicine, and family medicine. We describe the clinic experience in providing preventive medical services to international travelers. Summer months are the busiest. Destinations of the travelers show a clear predominance of travel to less-developed countries, and this is refle...

  4. 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.

  5. Viral hepatitis in international travellers: risks and prevention.

    Science.gov (United States)

    Khuroo, Mohammad Sultan

    2003-02-01

    Viral hepatitis is caused by a number of unrelated hepatotrophic viruses, known and unknown. Five hepatitis viruses namely HAV, HBV, HCV, HDV and HEV have been well characterized and the epidemiology and disease pattern of each agent has been defined. In the West, HAV, HBV and HCV are major causes of viral hepatitis. In the East, HEV is the most common cause of viral hepatitis. HAV is ubiquitous in childhood in such countries and accounts for less than 4% of disease in adults. Viral hepatitis becomes a problem to an international traveller when he envisages a journey from low endemic to high endemic area and is susceptible to the infection endemic at his destination. Millions of such potentially susceptible travellers from Europe, the USA, Canada, Japan, Australia, and New Zealand visit endemic areas every year for various reasons. Viral hepatitis is the most common reported immunization-preventable disease among travellers to developing countries. Imported viral hepatitis incapacitates the incumbents for an average of 4-10 weeks. Considering the magnitude of the travel, the number of cases of viral hepatitis and case fatality of around 2%, the disease causes significant morbidity and mortality in such communities. It has been estimated that viral hepatitis occurs 100 times more frequently than typhoid fever and 1,000 times more often than cholera in travellers to developing countries. Hepatitis A is the most common form of viral hepatitis in travellers and cumulative data have shown a risk of 3-6 cases/1,000 persons/month of stay whereas the risk of acquiring hepatitis B is 10 times lower.

  6. 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

  7. Business Travellers Vote DRAGONAIR "Best China Airline"

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ (BEIJING) Dragonair was announced as winner of the Best China Airline category in the Business Traveller Asia-Pacific 2005 Annual Travel Awards today. The magazine asked subscribers who were frequent travellers to vote for an airline based on 17 criteria,including cabin staff, comfort, route network and scheduling.

  8. 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...

  9. [Cyclospora cayetanensis outbreak in travelers to Cuba].

    Science.gov (United States)

    Ramírez-Olivencia, Germán; Herrero, Maria Dolores; Subirats, Mercedes; Rivas González, Pablo; Puente, Sabino

    2008-11-01

    Initially described in travelers, outbreaks of cyclosporiasis were soon linked to imported food products. An outbreak of cyclosporiasis in Spanish travelers is described. After identification of Cyclospora cayetanensis in stool analyses, a specific questionnaire was completed. Pyrosis was described in 57% of cases (4/7). Peptic symptoms can be a useful clue to indicate the diagnosis of cyclosporiasis in patients with travelers' diarrhea.

  10. Travelling 'green': Is tourists' happiness at stake?

    NARCIS (Netherlands)

    J. Nawijn (Jeroen); P.M. Peeters (Paul)

    2010-01-01

    textabstractSeveral 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 ave

  11. 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...

  12. Business Travellers Vote DRAGONAIR "Best China Airline"

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

      (BEIJING) Dragonair was announced as winner of the Best China Airline category in the Business Traveller Asia-Pacific 2005 Annual Travel Awards today. The magazine asked subscribers who were frequent travellers to vote for an airline based on 17 criteria,including cabin staff, comfort, route network and scheduling.……

  13. 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)

  14. Discounts at the Carlson Wagonlit travel agency

    CERN Multimedia

    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.

  15. Traveling waves in an optimal velocity model of freeway traffic

    Science.gov (United States)

    Berg, Peter; Woods, Andrew

    2001-03-01

    Car-following models provide both a tool to describe traffic flow and algorithms for autonomous cruise control systems. Recently developed optimal velocity models contain a relaxation term that assigns a desirable speed to each headway and a response time over which drivers adjust to optimal velocity conditions. These models predict traffic breakdown phenomena analogous to real traffic instabilities. In order to deepen our understanding of these models, in this paper, we examine the transition from a linear stable stream of cars of one headway into a linear stable stream of a second headway. Numerical results of the governing equations identify a range of transition phenomena, including monotonic and oscillating travelling waves and a time- dependent dispersive adjustment wave. However, for certain conditions, we find that the adjustment takes the form of a nonlinear traveling wave from the upstream headway to a third, intermediate headway, followed by either another traveling wave or a dispersive wave further downstream matching the downstream headway. This intermediate value of the headway is selected such that the nonlinear traveling wave is the fastest stable traveling wave which is observed to develop in the numerical calculations. The development of these nonlinear waves, connecting linear stable flows of two different headways, is somewhat reminiscent of stop-start waves in congested flow on freeways. The different types of adjustments are classified in a phase diagram depending on the upstream and downstream headway and the response time of the model. The results have profound consequences for autonomous cruise control systems. For an autocade of both identical and different vehicles, the control system itself may trigger formations of nonlinear, steep wave transitions. Further information is available [Y. Sugiyama, Traffic and Granular Flow (World Scientific, Singapore, 1995), p. 137].

  16. Supersonic stall flutter of high-speed fans

    Science.gov (United States)

    Adamczyk, J. J.; Stevans, W.; Jutras, R.

    1981-01-01

    An analytical model is proposed for predicting the onset of supersonic stall bending flutter in high-speed rotors. The analysis is based on a modified two-dimensional, compressible, unsteady actuator disk theory. The stability boundary predicted by the analysis is shown to be in good agreement with the measured boundary of a high speed fan. The prediction that the flutter mode would be a forward traveling wave sensitive to wheel speed and aerodynamic loading is confirmed by experimental measurements. In addition, the analysis shows that reduced frequency and dynamic head also play a significant role in establishing the supersonic stall bending flutter boundary of an unshrouded fan.

  17. Fundamentals of traveling wave ion mobility spectrometry.

    Science.gov (United States)

    Shvartsburg, Alexandre A; Smith, Richard D

    2008-12-15

    Traveling wave ion mobility spectrometry (TW IMS) is a new IMS method implemented in the Synapt IMS/mass spectrometry system (Waters). Despite its wide adoption, the foundations of TW IMS were only qualitatively understood and factors governing the ion transit time (the separation parameter) and resolution remained murky. Here we develop the theory of TW IMS using derivations and ion dynamics simulations. The key parameter is the ratio (c) of ion drift velocity at the steepest wave slope to wave speed. At low c, the ion transit velocity is proportional to the squares of mobility (K) and electric field intensity (E), as opposed to linear scaling in drift tube (DT) IMS and differential mobility analyzers. At higher c, the scaling deviates from quadratic in a way controlled by the waveform profile, becoming more gradual with the ideal triangular profile but first steeper and then more gradual for realistic profiles with variable E. At highest c, the transit velocity asymptotically approaches the wave speed. Unlike with DT IMS, the resolving power of TW IMS depends on mobility, scaling as K(1/2) in the low-c limit and less at higher c. A nonlinear dependence of the transit time on mobility means that the true resolving power of TW IMS differs from that indicated by the spectrum. A near-optimum resolution is achievable over an approximately 300-400% range of mobilities. The major predicted trends are in agreement with TW IMS measurements for peptide ions as a function of mobility, wave amplitude, and gas pressure. The issues of proper TW IMS calibration and ion distortion by field heating are also discussed. The new quantitative understanding of TW IMS separations allows rational optimization of instrument design and operation and improved spectral calibration.

  18. 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 usual

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

    NARCIS (Netherlands)

    de Vries, Anne

    2016-01-01

    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

  20. 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/

  1. Multiply Phased Traveling BPS Vortex

    CERN Document Server

    Kimm, Kyoungtae; Cho, Y M

    2016-01-01

    We present the multiply phased current carrying vortex solutions in the U(1) gauge theory coupled to an $(N+1)$-component SU(N+1) scalar multiplet in the Bogomolny limit. Our vortex solutions correspond to the static vortex dressed with traveling waves along the axis of symmetry. What is notable in our vortex solutions is that the frequencies of traveling waves in each component of the scalar field can have different values. The energy of the static vortex is proportional to the topological charge of $CP^N$ model in the BPS limit, and the multiple phase of the vortex supplies additional energy contribution which is proportional to the Noether charge associated to the remaining symmetry.

  2. Plasma Colloquium Travel Grant Program

    Energy Technology Data Exchange (ETDEWEB)

    Hazeltine, R.D.

    1998-09-14

    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.

  3. Fast Moving Average Recursive Least Mean Square Fit

    Science.gov (United States)

    2016-06-07

    Method 4.2 Numerical Simulation 4.3 Speed Comparisons .• 4.4 Discussion of Results • SUMMARY AND CONCLUSIONS REFERENCES...the method of implementation, numerical accuracy, computer simulation procedure, and the result of computing timings between the batch and the...due to reduced computation could make the moving average LMSF procedure competitive for many real-time processing applications . 15. SUBJECT TERMS

  4. Strong and Weak Property of Travelling Wave Front Solutions for a Class of Degenerate Parabolic Equations

    Institute of Scientific and Technical Information of China (English)

    LI Zheng-yuan; LIU Ying-dong; YE Qi-xiao

    2001-01-01

    In this paper we study the strong and weak property of travelling wave front solutions for a class of degenerate parabolic equations. How the strong and weak property changes under the effects of wave speed and reaction-diffusion terms are showed.

  5. Effect of fare and travel time on the demand for domestic air transportation

    Science.gov (United States)

    Eriksen, S. E.; Liu, E. W.

    1979-01-01

    An econometric travel demand model was presented. The model was used for analyzing long haul domestic passenger markets in the United States. The results showed the sensitivities of demand to changes in fares and speed reflecting technology through more efficient aircraft designs.

  6. Minimum Covering with Travel Cost

    CERN Document Server

    Fekete, Sandor P; Schmidt, Christiane

    2011-01-01

    Given a polygon and a visibility range, the Myopic Watchman Problem with Discrete Vision (MWPDV) asks for a closed path P and a set of scan points S, such that (i) every point of the polygon is within visibility range of a scan point; and (ii) path length plus weighted sum of scan number along the tour is minimized. Alternatively, the bicriteria problem (ii') aims at minimizing both scan number and tour length. We consider both lawn mowing (in which tour and scan points may leave P) and milling (in which tour, scan points and visibility must stay within P) variants for the MWPDV; even for simple special cases, these problems are NP-hard. We show that this problem is NP-hard, even for the special cases of rectilinear polygons and L_\\infty scan range 1, and negligible small travel cost or negligible travel cost. For rectilinear MWPDV milling in grid polygons we present a 2.5-approximation with unit scan range; this holds for the bicriteria version, thus for any linear combination of travel cost and scan cost. F...

  7. 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.

  8. The origin of traveling waves in an emperor penguin huddle

    OpenAIRE

    Gerum, RC; Fabry, B.; Metzner, C.; Beaulieu, M.; Ancel, A.; Zitterbart, Daniel

    2013-01-01

    Emperor penguins breed during the Antarctic winter and have to endure temperatures as low as −50 °C and wind speeds of up to 200 km h−1. To conserve energy, they form densely packed huddles with a triangular lattice structure. Video recordings from previous studies revealed coordinated movements in regular wave-like patterns within these huddles. It is thought that these waves are triggered by individual penguins that locally disturb the huddle structure, and that the traveling wave serves to...

  9. An Improved Particle Swarm Optimization for Traveling Salesman Problem

    Science.gov (United States)

    Liu, Xinmei; Su, Jinrong; Han, Yan

    In allusion to particle swarm optimization being prone to get into local minimum, an improved particle swarm optimization algorithm is proposed. The algorithm draws on the thinking of the greedy algorithm to initialize the particle swarm. Two swarms are used to optimize synchronously. Crossover and mutation operators in genetic algorithm are introduced into the new algorithm to realize the sharing of information among swarms. We test the algorithm with Traveling Salesman Problem with 14 nodes and 30 nodes. The result shows that the algorithm can break away from local minimum earlier and it has high convergence speed and convergence ratio.

  10. GPS observation of traveling ionospheric disturbances related to Moscow megacity

    Science.gov (United States)

    Zakharov, V. I.; Gorchakov, G. I.

    2017-01-01

    We present the results of GPS-signal radio interferometry observations obtained in the period of summer 2010 (97 days) at the stations in the Moscow region. The stations belong to MNGS (Moscow Navigational and Geodetic Support) and IGS (International Geophysical Services) networks. We observed traveling ionospheric disturbances (TIDs) in a ring form around Moscow. Empirical functions of the parameters (motion speed and observation period) are obtained and discussed. It is shown that the observed distributions are manifestations of the acoustic-gravity waves and may be associated with a special heat regime, including the urban heat island established in the Moscow region during summer 2010 in the conditions of a blocking anticyclone.

  11. Controlling the onset of turbulence by streamwise traveling waves. Part 1: Receptivity analysis

    CERN Document Server

    Moarref, Rashad

    2010-01-01

    We examine the efficacy of streamwise traveling waves generated by a zero-net-mass-flux surface blowing and suction for controlling the onset of turbulence in a channel flow. For small amplitude actuation, we utilize weakly nonlinear analysis to determine base flow modifications and to assess the resulting net power balance. Receptivity analysis of the velocity fluctuations around this base flow is then employed to design the traveling waves. Our simulation-free approach reveals that, relative to the flow with no control, the downstream traveling waves with properly designed speed and frequency can significantly reduce receptivity which makes them well-suited for controlling the onset of turbulence. In contrast, the velocity fluctuations around the upstream traveling waves exhibit larger receptivity to disturbances. Our theoretical predictions, obtained by perturbation analysis (in the wave amplitude) of the linearized Navier-Stokes equations with spatially periodic coefficients, are verified using full-scale...

  12. L2-stability of traveling wave solutions to nonlocal evolution equations

    Science.gov (United States)

    Lang, Eva; Stannat, Wilhelm

    2016-10-01

    Stability of the traveling wave solution to a general class of one-dimensional nonlocal evolution equations is studied in L2-spaces, thereby providing an alternative approach to the usual spectral analysis with respect to the supremum norm. We prove that the linearization around the traveling wave solution satisfies a Lyapunov-type stability condition in a weighted space L2 (ρ) for a naturally associated density ρ. The result can be applied to obtain stability of the traveling wave solution under stochastic perturbations of additive or multiplicative type. For small wave speeds, we also prove an alternative Lyapunov-type stability condition in L2 (m), where m is the symmetrizing density for the traveling wave operator, which allows to derive a long-term stochastic stability result.

  13. Convergence to travelling waves in Fisher's population genetics model with a non-Lipschitzian reaction term.

    Science.gov (United States)

    Drábek, Pavel; Takáč, Peter

    2017-02-14

    We consider a one-dimensional population genetics model for the advance of an advantageous gene. The model is described by the semilinear Fisher equation with unbalanced bistable non-Lipschitzian nonlinearity f(u). The "nonsmoothness" of f allows for the appearance of travelling waves with a new, more realistic profile. We study existence, uniqueness, and long-time asymptotic behavior of the solutions u(x, t), [Formula: see text]. We prove also the existence and uniqueness (up to a spatial shift) of a travelling wave U. Our main result is the uniform convergence (for [Formula: see text]) of every solution u(x, t) of the Cauchy problem to a single travelling wave [Formula: see text] as [Formula: see text]. The speed c and the travelling wave U are determined uniquely by f, whereas the shift [Formula: see text] is determined by the initial data.

  14. Vehicle routing problem with time-varying speed

    Institute of Scientific and Technical Information of China (English)

    LIU Yun-zhong

    2010-01-01

    Vehicle routing problem with time-varying speed(VRPTS)is a generalization of vehicle routing problem in which the travel speed between two locations depends on the passing areas and the time of a day.This paper proposes a simple model for estimating time-varying travel speeds in VRPTS that relieves much bur den to the data-related problems.The study further presents three heuristics(saving technique,proximity priority searching technique,and insertion technique)for VRPTS,developed by extending and modifying the existing heuristics for conventional VRP.The results of computational experiments demonstrate that the proposed estimation model performs well and the saving technique is the best among the three heuristics.

  15. The elite weightlifter's strength and speed qualities

    Directory of Open Access Journals (Sweden)

    Yukhno Y.O.

    2010-01-01

    Full Text Available The problems of estimation of power and speed possibilities of skilled weightlifter's are considered. In an experiment used complex REV 9000. The method of biomechanics control is developed. It allows in optimum terms to estimate the level of development of separate biolinks of body of sportsman. Speed power possibilities of right extensor higher on the average on 13%. Razgibatel' has large readiness to active reduction in the conditions of considerable tensions.

  16. The elite weightlifter's strength and speed qualities

    OpenAIRE

    Yukhno Y.O.; Sergienko K.N.; Khmelnitska I.V.

    2010-01-01

    The problems of estimation of power and speed possibilities of skilled weightlifter's are considered. In an experiment used complex REV 9000. The method of biomechanics control is developed. It allows in optimum terms to estimate the level of development of separate biolinks of body of sportsman. Speed power possibilities of right extensor higher on the average on 13%. Razgibatel' has large readiness to active reduction in the conditions of considerable tensions.

  17. [True and virtual risks of travellers].

    Science.gov (United States)

    Hatz, C; Walz, A; Genton, B; Behrens, R

    2014-05-01

    Evidence-based information on travel associated mortality is scarce. Perception, intuition and the availability of interventions such as vaccinations and chemoprophylaxis often guide pre-travel advice. Important risks including accidents and cardiovascular events are not routinely included in pre-travel consultations although they cause more fatalities and costs than infectious diseases. The increased risk of sustaining a road accident in poor economy countries should always be mentioned. The general practitioner is further best placed to discuss possible problems of travellers with chronic diseases before travel.

  18. Tourists get US visas for group travel

    Institute of Scientific and Technical Information of China (English)

    Robert Goodman

    2008-01-01

    <正>Chinese will soon be able to travel to the United States on tourist visas,according to an agreement signed in Beijing Tuesday. The memorandum of understanding(MOU) signed between the two countries to facilitate outbound tourist group travel grants the US Approved Destination Status(ADS) after years of negotiations,making it the 134th country on China’s list. Chinese travelers will be able to travel in groups as early as in spring.Currently,the US issues only business travel visas.

  19. TRAVEL

    Institute of Scientific and Technical Information of China (English)

    Carrie Tsang; Phoenix

    2010-01-01

    <正>01意大利首间国家级当代艺术博物馆>由Zaha Hadid建筑事务所设计的MAXXINational Museum of XXI Century Arts位于罗马,是意大利第一个致力于当代艺术的国家公共博物馆。Zaha Hadid在1999年胜出了这个项目的国际设计比赛,2003年开始动工,工程目前已进入完竣阶段,为馆址

  20. TRAVEL

    Institute of Scientific and Technical Information of China (English)

    Venice Lau

    2012-01-01

    <正>01拥抱三百六十度天堂级珊瑚水景〉马尔代夫向来都是热门的旅游胜地,最近由Dusit集团开设的Dusit Thani Maldives豪华酒店于今年二月落成,成为当地的新地标。酒店位于Baa Atoll的Mudhdhoo lsland岛上,从首都马累乘坐海上飞机三十五分钟便可到达。一百幢独立别墅充满泰式的建筑艺术气息,而且配备高科技设计。不同特色的度假别墅包括海滩别墅(Beac:h Villas)、舄湖别墅(LagoorVillas)及海洋别墅(Ocean Villas),此外更有两种极尽豪华的海洋亭阁(Ocean Pavilions)及海滩府邸(Ocean Resldences),每幢

  1. Performance and Ease Influence Perceived Speed.

    OpenAIRE

    Witt, Jessica; Sugovic, Mila

    2010-01-01

    According to the action-specific perception account, perception is a function of optical information and the perceiver’s ability to perform the intended action. While most of the evidence for the action-specific perception account is on spatial perception, in the current experiments we examined similar effects in the perception of speed. Tennis players reproduced the time the ball traveled from the feeder machine to when they hit it. The players judged the ball to be moving faster on trials w...

  2. 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.

  3. [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.

  4. The Optimization of Passengers’ Travel Time under Express-Slow Mode Based on Suburban Line

    Directory of Open Access Journals (Sweden)

    Xiaobing Ding

    2016-01-01

    Full Text Available The suburban line connects the suburbs and the city centre; it is of huge advantage to attempt the express-slow mode. The passengers’ average travel time is the key factor to reflect the level of rail transport services, especially under the express-slow mode. So it is important to study the passengers’ average travel time under express-slow, which can get benefit on the optimization of operation scheme. First analyze the main factor that affects passengers’ travel time and then mine the dynamic interactive relationship among the factors. Second, a new passengers’ travel time evolution algorithm is proposed after studying the stop schedule and the proportion of express/slow train, and then membrane computing theory algorithm is introduced to solve the model. Finally, Shanghai Metro Line 22 is set as an example to apply the optimization model to calculate the total passengers’ travel time; the result shows that the total average travel time under the express-slow mode can save 1 minute and 38 seconds; the social influence and value of it are very huge. The proposed calculation model is of great help for the decision of stop schedule and provides theoretical and methodological support to determine the proportion of express/slow trains, improves the service level, and enriches and complements the rail transit operation scheme optimization theory system.

  5. INTELLIGENT SPEED ADAPTATION (ISA AND ROAD SAFETY

    Directory of Open Access Journals (Sweden)

    H.L. OEI, M.Sc.

    2002-01-01

    Full Text Available An ISA system consists of GPS to determine the car's position, a CD-ROM in the car containing information of a road network including the prevailing speed limit of each road section, and feedback to the driver. Experiments in Sweden are testing several options, from warning the driver to a resisting force exerted by the accelerator pedal that can be countered by the driver. In the Netherlands the system intervenes so the limit cannot be exceeded. Experiments in Sweden have recently been concluded and an evaluation is in progress. In the Netherlands the project was concluded early 2001. The field experiments so far mainly concern the measure of acceptance of the system(s by the public. Several simulation studies have also been conducted. Little is known as yet from practical research of the effects of ISA on road safety, though a large safety potential is assumed. For the Dutch situation, based on the assumption that all passenger cars are fitted with ISA and an assumed speed distribution as the result of ISA, a theoretical calculation is made of the effects of ISA on speed and safety. The result is an estimated reduction of road casualties of 25 to 30%. Further, the assumed speed distribution is validated with field measurements of the experiment in the city of Tilburg. The result is that the measured average speed of the speed distribution fits quite well with the calculated average speed.

  6. Optimal swimming speed in head currents and effects on distance movement of winter-migrating fish

    DEFF Research Database (Denmark)

    Brodersen, J.; Nilsson, P.A.; Ammitzbøl, J.

    2008-01-01

    ecologically and economically important. We here use passive and active telemetry to study how winter migrating roach regulate swimming speed and distance travelled per day in response to variations in head current velocity. Furthermore, we provide theoretical predictions on optimal swimming speeds in head...... currents and relate these to our empirical results. We show that fish migrate farther on days with low current velocity, but travel at a greater ground speed on days with high current velocity. The latter result agrees with our predictions on optimal swimming speed in head currents, but disagrees...... with previously reported predictions suggesting that fish ground speed should not change with head current velocity. We suggest that this difference is due to different assumptions on fish swimming energetics. We conclude that fish are able to adjust both swimming speed and timing of swimming activity during...

  7. 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.

  8. Determination trends and abnormal seasonal wind speed in Iraq

    Energy Technology Data Exchange (ETDEWEB)

    Hassoon, Ahmed F. [Department of Atmospheric Sciences, College of Science, AL- Mustansiriyah University, Baghdad (Iraq)

    2013-07-01

    Monthly observed wind speed data at four weather stations (Baghdad, Mosul, Basra, Rutba) at 10m above surface were used to explore the temporal variations of the wind speed (1971-2000) in Iraq. There are different methods to analyze wind speed variation data, but the time series are one of the powerful analysis methods to diagnose the seasonal wind speed anomaly. The results show most high abnormal data is found in summer seasons in all the stations of study, where it concentrated at 1975, 1976, 1978,1996-1995, 2000. Rutba station is different where its high deviation about annual average at nearly all the seasons, in this station there are trends in seasonal wind towards decreases in all the seasons, for example in winter it reached to about 0.046m/s.a-1, while in other stations Mosul and Basra there increases in annual seasonal wind speed trends in seasons spring, summer, autumn where its reached higher value at summer in Basra about 0.0482m/s.a-1. The second method to determine abnormal annual seasonal wind speed is through comparison seasonal average wind speed, where the average wind speed at the seasons summer and spring in Baghdad and Basra station have very high averages at nearly all years, this cannot see in Mosul and Rutba, in Rutba the seasonal average is intersected with each other, summer and spring is not have greater seasonal average in this station.

  9. Travel Writing Revisited1 Travel Writing Revisited1

    Directory of Open Access Journals (Sweden)

    Édina Pereira Crunfli

    2008-04-01

    Full Text Available In compiling the essays for this volume, Steve Clark’s main concern is a revisionist one. This collection represents a shift away from what is sometimes called the “homoglossic” obsession with Empire present in postcolonial theory, from Edward Said’s influential Orientalism (1978, through Mary Louise Pratt’s Imperial Eyes (1992, to David Spurr’s The Rhetoric of Empire (1993. This book resists the temptation to think in terms of “the reduction of cross-cultural encounter to simple relations of domination and subordination.” Challenging Pratt, Clark describes her thesis (of travel writing producing the rest of the world for European readerships at particular points in Europe’s expansionist trajectory as “hyperbolic”. In compiling the essays for this volume, Steve Clark’s main concern is a revisionist one. This collection represents a shift away from what is sometimes called the “homoglossic” obsession with Empire present in postcolonial theory, from Edward Said’s influential Orientalism (1978, through Mary Louise Pratt’s Imperial Eyes (1992, to David Spurr’s The Rhetoric of Empire (1993. This book resists the temptation to think in terms of “the reduction of cross-cultural encounter to simple relations of domination and subordination.” Challenging Pratt, Clark describes her thesis (of travel writing producing the rest of the world for European readerships at particular points in Europe’s expansionist trajectory as “hyperbolic”.

  10. Traveling waves in rapid solidification

    Directory of Open Access Journals (Sweden)

    Karl Glasner

    2000-02-01

    Full Text Available We analyze rigorously the one-dimensional traveling wave problem for a thermodynamically consistent phase field model. Existence is proved for two new cases: one where the undercooling is large but not in the hypercooled regime, and the other for waves which leave behind an unstable state. The qualitative structure of the wave is studied, and under certain restrictions monotonicity of front profiles can be obtained. Further results, such as a bound on propagation velocity and non-existence are discussed. Finally, some numerical examples of monotone and non-monotone waves are provided.

  11. Improved Traveling-Wave Tube

    Science.gov (United States)

    Rousseau, Art; Tammaru, Ivo; Vaszari, John

    1988-01-01

    New space traveling-wave tube (TWT) provides coherent source of 75 watts of continuous-wave power output over bandwidth of 5 GHz at frequency of 65 GHz. Coupled-cavity TWT provides 50 dB of saturated gain. Includes thermionic emitter, M-type dispenser cathode providing high-power electron beam. Beam focused by permanent magnets through center of radio-frequency cavity structure. Designed for reliable operation for 10 years, and overall efficiency of 35 percent minimizes prime power input and dissipation of heat.

  12. 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

    ... ADMINISTRATION Federal Travel Regulation; GSA E-Gov Travel Service (ETS) Transition to E-Gov Travel Service 2... of a bulletin. SUMMARY: The attached bulletin announces GSA ETS Transition to ETS2. DATES: Effective.... Frank Robinson, ETS Program Manager Center for Travel Management (QMCD), Office of Travel...

  13. 7 CFR 1209.12 - On average.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false On average. 1209.12 Section 1209.12 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS....12 On average. On average means a rolling average of production or imports during the last two...

  14. ASSESSMENT OF COLLECTIVE DOSE FOR TRAVELLERS BY WATERS

    Institute of Scientific and Technical Information of China (English)

    岳清宇; 姜萍; 等

    1995-01-01

    People travelling by air will receive more exposure dose and by water will receive less one.According to statistic data from the Ministry of Communications in 1988,the turnover in that year was about 2×1010 man.km.The total number of fishermen for inshore fishing was nearly two million reported by Ministry of Agriculture,Animal Husbandry and Fishery.Based on measured data on 212 points in six typical shipping lines of inshore lines and inland rivers,and the total voyage is 5625km,the average natural radiation dose rate received by travellers was calculated.From that assessment of collective effective dose for passengers by water and fishermen was derived.The value is 32.7man.Sv for passengers and 265.3man.Sv for fishermen.

  15. 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

    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 proble......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...... ownership and a consequently underestimation of the respective income elasticity. The study evaluates the impact of measurement error and reveals considerable problems in the data collection of income which in this case reduces the income elasticity. The second paper includes all three Danish travel surveys...... between 0.1-1.4 when iv measured in terms of travel demand and from 0.2-0.6 when measured in terms of travel distances. The final paper differs from the others as it explores and evaluates the impacts of the Oresund Bridge ten years after its opening. The new bridge resulted in significant changes...

  16. A Study of Wind Statistics Through Auto-Regressive and Moving-Average (ARMA) Modeling

    Institute of Scientific and Technical Information of China (English)

    尹彰; 周宗仁

    2001-01-01

    Statistical properties of winds near the Taichung Harbour are investigated. The 26 years′incomplete data of wind speeds, measured on an hourly basis, are used as reference. The possibility of imputation using simulated results of the Auto-Regressive (AR), Moving-Average (MA), and/or Auto-Regressive and Moving-Average (ARMA) models is studied. Predictions of the 25-year extreme wind speeds based upon the augmented data are compared with the original series. Based upon the results, predictions of the 50- and 100-year extreme wind speeds are then made.

  17. Analysis Groove Characteristics of Friction Dishes in Wet Speeding Clutch

    Institute of Scientific and Technical Information of China (English)

    HongYue; LiuJin; JinShiliang

    2004-01-01

    The impacts of different groove shapes, numbers, and angle of friction dish on transmitting torque, speed, push pressure in wet speeding clutch are discussed in this paper. Since the wet speeed governing clutch works within hydrodynamic lubrication mixture lubrication. boundary, lubrication and contact situation, the oils combining with a-hydrocarbon or polyester are getting widely used as lubricant.The power-law fluid model with Patir-Cheng average flow model, GT asperity contact model and oil film inertia are applied for average Reynolds equation setting, In order to investigate the relationship between average push pressure within hydrodynamic lubrication and mixture lubrication, average transmitting torque and output speed, the numeral calculation and analysis are presented. According to calculation, it is found that the groove shape, groove angle and groove numbers affect the average transfer torque and push pressure with the speed rate.

  18. 46 CFR 154.1864 - Vessel speed within speed reduction.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vessel speed within speed reduction. 154.1864 Section... Vessel speed within speed reduction. The master shall ensure that the speed of the vessel is not greater than the posted speed reduction....

  19. [Infectious aetiologies of travelers' diarrhoea].

    Science.gov (United States)

    Cavallo, J-D; Garrabé, E

    2007-11-01

    Traveler's diarrhoea (TD) occurs in 20 to 60% of European or North-American travelers in intertropical areas. Following return from endemic zone, malaria must always be evocated in front of febrile diarrhoea. Many causative infectious agents are involved in TD and their frequency may vary according to destination and seasons. The main agents involved in TD are Escherichia coli pathovars (especially enterotoxigenic and enteroaggregative E. coli) followed by enteroinvasive bacteria (Campylobacter spp., Shigella spp., Salmonella enterica), enteric viruses (norovirus, rotavirus) and protozoa (Gardia intestinalis, Cryptosporidium parvum et Entamoeba histolytica). The development of molecular biology methods as PCR may allow us to evaluate the relative frequency of these agents and especially of viral agents in TD. Protozoa and microsporidia are more frequently isolated in persistent and chronic TD, especially in compromised patients. A complete etiological research in routine microbiology laboratories is difficult and time-consuming, related to the high diversity of causative agents and the need for specific methods. Implementation of laboratory diagnosis is highly recommended when diarrhoea is associated with fever or presence of blood in stools, immunosuppression, antibiotic treatment (Clostridium difficile toxins) or in case of persistent/chronic diarrhoea. According to the high frequency of acquired antibiotic-resistance in enteric bacteria, an antibiogram must be performed for all causative bacterial agents.

  20. Is Interstellar Space Travel Possible?

    CERN Document Server

    Singal, Tanmay

    2013-01-01

    It is shown that space travel, even in the most distant future, will remain confined to our own planetary system, and a similar conclusion will hold forth for any other civilization, no matter how advanced it might be, unless those extra-terrestrial species have life spans order of magnitude longer than ours. Even in such a case it is unlikely that they will travel much farther than their immediate stellar neighbourhood, as each such excursion will exhaust the resources of their home planet so much that those will dwindle rather fast and there might not be much left for the further scientific and technological advancements. So the science-fiction fancy of a "Galactic Empire" may ever remain in our fantasies only. And as for the mythical UFOs, whose quiet appearances do get reported in the press once in a while, recent explorations have shown no evidence that any such thing could have an origination within our own solar system itself. And a "quiet trip" back and forth from a distant star is almost impossible a...

  1. [Travellers and multi-drug resistance bacteria].

    Science.gov (United States)

    Takeshita, Nozomi

    2012-02-01

    The number of international travellers has increased. There is enormous diversity in medical backgrounds, purposes of travel, and travelling styles among travellers. Travellers are hospitalized abroad because of exotic and common diseases via medical tourism. This is one way of transporting and importing human bacteria between countries, including multi-drug resistant organisms. In developing countries, the antimicrobial resistance in Shigella sp. and Salmonella sp. have been a problem, because of this trend, the first choice of antibiotics has changed in some countries. Community acquired infections as well as hospital acquired infections with MRSA, multi-drug resistance (MDR) Pseudomonas aeruginosa, and ESBL have been a problem. This review will discuss the risk of MDR bacterial infectious diseases for travellers.

  2. Traveling Lamb wave in elastic metamaterial layer

    Science.gov (United States)

    Shu, Haisheng; Xu, Lihuan; Shi, Xiaona; Zhao, Lei; Zhu, Jie

    2016-10-01

    The propagation of traveling Lamb wave in single layer of elastic metamaterial is investigated in this paper. We first categorized the traveling Lamb wave modes inside an elastic metamaterial layer according to different combinations (positive or negative) of effective medium parameters. Then the impacts of the frequency dependence of effective parameters on dispersion characteristics of traveling Lamb wave were studied. Distinct differences could be observed when comparing the traveling Lamb wave along an elastic metamaterial layer with one inside the traditional elastic layer. We further examined in detail the traveling Lamb wave mode supported in elastic metamaterial layer, when the effective P and S wave velocities were simultaneously imaginary. It was found that the effective modulus ratio is the key factor for the existence of special traveling wave mode, and the main results were verified by FEM simulations from two levels: the level of effective medium and the level of microstructure unit cell.

  3. Exponentially slow traveling waves on a finite interval for Burgers' type equation

    Directory of Open Access Journals (Sweden)

    Pieter De Groen

    1998-11-01

    Full Text Available In this paper we study for small positive $epsilon$ the slow motion of the solution for evolution equations of Burgers' type with small diffusion, $$ u_t=epsilon u_{xx}+f(u,u_x,, quad u(x,0=u_0(x, quad u(pm 1,t=pm 1, $$ on the bounded spatial domain $[-1,1]$; $f$ is a smooth function satisfying $f(1>0, f(-1<0$ and $int_{-1}^{1}f(tdt=0$. The initial and boundary value problem~($star$ has a unique asymptotically stable equilibrium solution that attracts all solutions starting with continuous initial data $u_0$. On the infinite spatial domain ${mathbb R}$ the differential equation has slow speed traveling wave solutions generated by profiles that satisfy the boundary conditions of~($star$. As long as its zero stays inside the interval $[-1,1]$, such a traveling wave suitably describes the slow long term behaviour of the solution of ($star$ and its speed characterizes the local velocity of the slow motion with exponential precision. A solution that starts near a traveling wave moves in a small neighborhood of the traveling wave with exponentially slow velocity (measured as the speed of the unique zero during an exponentially long time interval $(0,T$. In this paper we give a unified treatment of the problem, using both Hilbert space and maximum principle methods, and we give rigorous proofs of convergence of the solution and of the asymptotic estimate of the velocity.

  4. Order-Optimal Consensus through Randomized Path Averaging

    CERN Document Server

    Benezit, F; Thiran, P; Vetterli, M

    2008-01-01

    Gossip algorithms have recently received significant attention, mainly because they constitute simple and robust message-passing schemes for distributed information processing over networks. However for many topologies that are realistic for wireless ad-hoc and sensor networks (like grids and random geometric graphs), the standard nearest-neighbor gossip converges as slowly as flooding ($O(n^2)$ messages). A recently proposed algorithm called geographic gossip improves gossip efficiency by a $\\sqrt{n}$ factor, by exploiting geographic information to enable multi-hop long distance communications. In this paper we prove that a variation of geographic gossip that averages along routed paths, improves efficiency by an additional $\\sqrt{n}$ factor and is order optimal ($O(n)$ messages) for grids and random geometric graphs. We develop a general technique (travel agency method) based on Markov chain mixing time inequalities, which can give bounds on the performance of randomized message-passing algorithms operating...

  5. 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...

  6. Traveling Baseball Players' Problem in Korea

    OpenAIRE

    Jeong, Hyang Min; Kim, Sang-Woo; Kim, Aaram J.; Choi, Younguk; Eun, Jonghyoun; Kim, Beom Jun

    2012-01-01

    We study the so-called the traveling tournament problem (TTP), to find an optimal tournament schedule. Differently from the original TTP, in which the total travel distance of all the participants is the objective function to minimize, we instead seek to maximize the fairness of the round robin tournament schedule of the Korean Baseball League. The standard deviation of the travel distances of teams is defined as the energy function, and the Metropolis Monte-Carlo method combined with the sim...

  7. Spatially uniform microflows induced by thermoviscous expansion along a traveling temperature wave: Analogies with electro-osmotic transport

    Science.gov (United States)

    Pal, Debashis; Chakraborty, Suman

    2012-07-01

    We discover that thermoviscous expansion along a traveling wave in a microfluidic channel may be capable of generating a spatially uniform flow profile in a time-averaged sense. We further delineate that the resultant complex flow characteristics, realized by virtue of an intricate interplay between thermal compression-expansion waves and temperature-dependent viscosity variations and controlled by an external heating, may be remarkably characterized by a unique thermal penetration depth scale (analogous to Debye length in electro-osmosis) and a velocity scale (analogous to the Helmholtz Smulochowski velocity in electro-osmosis) that in turn depends on the considerations of “thin” and “thick” microchannel limits, as dictated by the thermal penetration depth as compared to the lateral extent of the microfluidic channel. We show that, when the thermal penetration depth is small as compared to the channel height, a uniform velocity profile is generated in the channel in a time-averaged sense. The velocity scale characterizing this uniform flow may be represented by a function of the thermal diffusivity, volumetric expansion coefficient and thermal viscosity coefficient of the fluid, characteristic amplitude and speed of the thermal wave, as well as the channel height. Results from the present study are expected to provide valuable insights towards arresting hydrodynamic dispersion in microchannels by nonelectrochemical means, following a pH-independent route.

  8. 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.

  9. [New approaches of malaria prevention for travelers].

    Science.gov (United States)

    Voumard, Rachel; Berthod, Delphine; Rochat, Laurence; D'Acremont, Valérie; Genton, Blaise; De Vallière, Serge

    2016-05-01

    Malaria is declining in many tropical countries. This reduction challenges our usual preventive strategies. In moderate to low risk areas, the Swiss guidelines recommend a stand-by emergency treatment. Controversies between experts are numerous though. Professionals at the Travel Clinic in Lausanne has explored shared-decision making through three clinical studies. The first showed that travelers visiting moderate to low risk malaria areas prefer a standby emergency treatment rather than chemoprophylaxis. The second study investigates the use of rapid diagnostic tests by travelers. The third focuses on the prospects of tropical telemedicine. Involving the traveler into the debate is a priority, until a vaccine becomes available.

  10. Willingness to travel to avoid conflicts in Danish forests

    DEFF Research Database (Denmark)

    Bakhtiari, Fatemeh; Jacobsen, Jette Bredahl; Jensen, Frank Søndergaard

    2014-01-01

    Conflicts among forest visitors have direct effects on the quality of a recreational experience. As the number of visitors to forests close to residential areas increases, as well as the number of different activities, so does the potential for perceived conflicts. According to the literature......, expanding knowledge of conflict characteristics and their causes is important for recreation planners and managers who aim to reduce conflicts. In the present study, different forest user groups were identified and categorised according to their pursued activities, and for each group, causes of conflict...... groups suggests that some groups have a WTT further than the average to reach a forest with ‘Few’ visitors. The average WTT to reach a forest area with ‘Few’ visitors. ‘Mountain bikers,’ ‘Peace and nature lovers’ and ‘Horse riders’ are willing to travel 4 km more than the average per visit to reach...

  11. Traveling Wave Solutions of An Ordinary-Parabolic System in R^2 and a 2D-Strip

    Directory of Open Access Journals (Sweden)

    Yanling Tian

    2016-04-01

    Full Text Available We investigate a prey-predator model, which we describe by an ordinary-parabolic system. We obtain four types of wave solutions of this system, which are connecting different equilibria. To establish the existence of four types of traveling wave solutions with double wave speeds, we introduce a new approach to constructing monotonous iteration schemes. Moreover, by using spreading speeds, we establish the non-existence of traveling wave solutions. Our results provide insight into the dynamics of this model system.

  12. Computation of traveling wave fronts for a nonlinear diffusion-advection model.

    Science.gov (United States)

    Mansour, M B A

    2009-01-01

    This paper utilizes a nonlinear reaction-diffusion-advection model for describing the spatiotemporal evolution of bacterial growth. The traveling wave solutions of the corresponding system of partial differential equations are analyzed. Using two methods, we then find such solutions numerically. One of the methods involves the traveling wave equations and solving an initial-value problem, which leads to accurate computations of the wave profiles and speeds. The second method is to construct time-dependent solutions by solving an initial-moving boundary-value problem for the PDE system, showing another approximation for such wave solutions.

  13. 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...

  14. 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...

  15. Traveling waves and breathers in an excitatory-inhibitory neural field

    Science.gov (United States)

    Folias, Stefanos E.

    2017-03-01

    We study existence and stability of traveling activity bump solutions in an excitatory-inhibitory (E-I) neural field with Heaviside firing rate functions by deriving existence conditions for traveling bumps and an Evans function to analyze their spectral stability. Subsequently, we show that these existence and stability results reduce, in the limit of wave speed c →0 , to the equivalent conditions developed for the stationary bump case. Using the results for the stationary bump case, we show that drift bifurcations of stationary bumps serve as a mechanism for generating traveling bump solutions in the E-I neural field as parameters are varied. Furthermore, we explore the interrelations between stationary and traveling types of bumps and breathers (time-periodic oscillatory bumps) by bridging together analytical and simulation results for stationary and traveling bumps and their bifurcations in a region of parameter space. Interestingly, we find evidence for a codimension-2 drift-Hopf bifurcation occurring as two parameters, inhibitory time constant τ and I-to-I synaptic connection strength w¯i i, are varied and show that the codimension-2 point serves as an organizing center for the dynamics of these four types of spatially localized solutions. Additionally, we describe a case involving subcritical bifurcations that lead to traveling waves and breathers as τ is varied.

  16. Automated Urban Travel Interpretation: A Bottom-up Approach for Trajectory Segmentation.

    Science.gov (United States)

    Das, Rahul Deb; Winter, Stephan

    2016-11-23

    Understanding travel behavior is critical for an effective urban planning as well as for enabling various context-aware service provisions to support mobility as a service (MaaS). Both applications rely on the sensor traces generated by travellers' smartphones. These traces can be used to interpret travel modes, both for generating automated travel diaries as well as for real-time travel mode detection. Current approaches segment a trajectory by certain criteria, e.g., drop in speed. However, these criteria are heuristic, and, thus, existing approaches are subjective and involve significant vagueness and uncertainty in activity transitions in space and time. Also, segmentation approaches are not suited for real time interpretation of open-ended segments, and cannot cope with the frequent gaps in the location traces. In order to address all these challenges a novel, state based bottom-up approach is proposed. This approach assumes a fixed atomic segment of a homogeneous state, instead of an event-based segment, and a progressive iteration until a new state is found. The research investigates how an atomic state-based approach can be developed in such a way that can work in real time, near-real time and offline mode and in different environmental conditions with their varying quality of sensor traces. The results show the proposed bottom-up model outperforms the existing event-based segmentation models in terms of adaptivity, flexibility, accuracy and richness in information delivery pertinent to automated travel behavior interpretation.

  17. APPLICATION OF TRAVEL TIME RELIABILITY FOR PERFORMANCE ORIENTED OPERATIONAL PLANNING OF EXPRESSWAYS

    Science.gov (United States)

    Mehran, Babak; Nakamura, Hideki

    Evaluation of impacts of congestion improvement scheme s on travel time reliability is very significant for road authorities since travel time reliability repr esents operational performance of expressway segments. In this paper, a methodology is presented to estimate travel tim e reliability prior to implementation of congestion relief schemes based on travel time variation modeling as a function of demand, capacity, weather conditions and road accident s. For subject expressway segmen ts, traffic conditions are modeled over a whole year considering demand and capacity as random variables. Patterns of demand and capacity are generated for each five minute interval by appl ying Monte-Carlo simulation technique, and accidents are randomly generated based on a model that links acci dent rate to traffic conditions. A whole year analysis is performed by comparing de mand and available capacity for each scenario and queue length is estimated through shockwave analysis for each time in terval. Travel times are estimated from refined speed-flow relationships developed for intercity expressways and buffer time index is estimated consequently as a measure of travel time reliability. For validation, estimated reliability indices are compared with measured values from empirical data, and it is shown that the proposed method is suitable for operational evaluation and planning purposes.

  18. More Than Just Speed

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The 1,318-km Beijing-Shanghai High-Speed Railway will finally come into operation at the end of June.Since construction began three years ago,the speedy railway has grabbed worldwide attention because of its design as the world’s longest and fastesthigh-speed rail line utilizing the most advanced technology.

  19. Speed enforcement in Norway

    DEFF Research Database (Denmark)

    Elvik, Rune

    2015-01-01

    This paper probes the relationship between changes in the risk of apprehension for speeding in Norway and changes in the amount of speeding. The paper is based on a game-theoretic model of how the rate of violations and the amount of enforcement is determined by the interaction between drivers...

  20. 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

  1. Condition monitoring of gearboxes using synchronously averaged electric motor signals

    Science.gov (United States)

    Ottewill, J. R.; Orkisz, M.

    2013-07-01

    Due to their prevalence in rotating machinery, the condition monitoring of gearboxes is extremely important in the minimization of potentially dangerous and expensive failures. Traditionally, gearbox condition monitoring has been conducted using measurements obtained from casing-mounted vibration transducers such as accelerometers. A well-established technique for analyzing such signals is the synchronous signal average, where vibration signals are synchronized to a measured angular position and then averaged from rotation to rotation. Driven, in part, by improvements in control methodologies based upon methods of estimating rotor speed and torque, induction machines are used increasingly in industry to drive rotating machinery. As a result, attempts have been made to diagnose defects using measured terminal currents and voltages. In this paper, the application of the synchronous signal averaging methodology to electric drive signals, by synchronizing stator current signals with a shaft position estimated from current and voltage measurements is proposed. Initially, a test-rig is introduced based on an induction motor driving a two-stage reduction gearbox which is loaded by a DC motor. It is shown that a defect seeded into the gearbox may be located using signals acquired from casing-mounted accelerometers and shaft mounted encoders. Using simple models of an induction motor and a gearbox, it is shown that it should be possible to observe gearbox defects in the measured stator current signal. A robust method of extracting the average speed of a machine from the current frequency spectrum, based on the location of sidebands of the power supply frequency due to rotor eccentricity, is presented. The synchronous signal averaging method is applied to the resulting estimations of rotor position and torsional vibration. Experimental results show that the method is extremely adept at locating gear tooth defects. Further results, considering different loads and different

  2. Adding a lens Improves spinning speed characterization.

    Science.gov (United States)

    Mihaliuk, Eugene; Gullion, Terry

    2015-11-01

    Highly stable sample rotation is important in many solid-state NMR experiments. Whether the necessary stability is achieved is not always clear. Typically only an average frequency over some time interval (often relatively long and unknown) is available from the spinning speed controller readout, which is not representative of the short-term variations of instantaneous rotation frequency. The necessity of the relatively slow measurement of spinning speed is a consequence of phase noise in the tachometer, which prevents speed measurement to be both rapid and precise at the same time. We show that adding a lens to the tachometer, without any other changes in the probe, reduces phase noise by nearly an order of magnitude and allows improved measurement of the spinning speed.

  3. Interpreting Sky-Averaged 21-cm Measurements

    Science.gov (United States)

    Mirocha, Jordan

    2015-01-01

    Within the first ~billion years after the Big Bang, the intergalactic medium (IGM) underwent a remarkable transformation, from a uniform sea of cold neutral hydrogen gas to a fully ionized, metal-enriched plasma. Three milestones during this epoch of reionization -- the emergence of the first stars, black holes (BHs), and full-fledged galaxies -- are expected to manifest themselves as extrema in sky-averaged ("global") measurements of the redshifted 21-cm background. However, interpreting these measurements will be complicated by the presence of strong foregrounds and non-trivialities in the radiative transfer (RT) modeling required to make robust predictions.I have developed numerical models that efficiently solve the frequency-dependent radiative transfer equation, which has led to two advances in studies of the global 21-cm signal. First, frequency-dependent solutions facilitate studies of how the global 21-cm signal may be used to constrain the detailed spectral properties of the first stars, BHs, and galaxies, rather than just the timing of their formation. And second, the speed of these calculations allows one to search vast expanses of a currently unconstrained parameter space, while simultaneously characterizing the degeneracies between parameters of interest. I find principally that (1) physical properties of the IGM, such as its temperature and ionization state, can be constrained robustly from observations of the global 21-cm signal without invoking models for the astrophysical sources themselves, (2) translating IGM properties to galaxy properties is challenging, in large part due to frequency-dependent effects. For instance, evolution in the characteristic spectrum of accreting BHs can modify the 21-cm absorption signal at levels accessible to first generation instruments, but could easily be confused with evolution in the X-ray luminosity star-formation rate relation. Finally, (3) the independent constraints most likely to aide in the interpretation

  4. Traveling waves of selective sweeps

    CERN Document Server

    Durrett, Rick

    2009-01-01

    The goal of cancer genome sequencing projects is to determine the genetic alterations that cause common cancers. Many malignancies arise during the clonal expansion of a benign tumor which motivates the study of recurrent selective sweeps in an exponentially growing population. To better understand this process, Beerenwinkel et al.(2007) consider a Wright-Fisher model in which cells from an exponentially growing population accumulate advantageous mutations. Simulations show a traveling wave in which the time of the first k-fold mutant, $\\tau_k$, is approximately linear in $k$ and heuristics are used to obtain formulas for $E\\tau_k$. Here, we consider the analogous problem for the Moran model and prove that as the mutation rate $\\mu\\to 0$, $\\tau_k \\sim c_k \\log(1/\\mu)$, where the $c_k$ can be computed explicitly.

  5. Enslaved Constitution: Obstructing the Freedom to Travel

    Directory of Open Access Journals (Sweden)

    Mitchell F. Crusto

    2008-04-01

    Full Text Available Does the Constitution protect a citizen’s intra-state travel (within a state from unjustified state prohibition? To date, the Supreme Court has not ruled directly on the issue, and many federal courts believe that the right to intrastate travel is not constitutionally protected. This Article explores the constitutional right of intra-state travel that is free from wrongful state infringement along public roadways by law-abiding citizens. Using critical legal history, this Article poses that federal courts’ denial of the right to intrastate travel consciously or unconsciously reflects the antebellum, Southern legal doctrine of people as property, which regulated the travel of enslaved African descendants.The constitutionality of intra-state travel arose most recently during the Hurricane Katrina Crisis when the City of Greta, Louisiana police barricaded a federal highway, denying would-be evacuees the ability to flee from the flooding City of New Orleans. In an ensuing action for infringement of the would-be evacuees’ constitutional right to intra-state travel, Federal District Judge Mary Ann Vial Lemmon dismissed the matter in Dickerson v. City of Gretna, holding that “[w]hile there is no doubt that a fundamental right of interstate travel exists, the Supreme Court has not ruled on whether a right of intra[-]state travel exists. This Court declines to find that there is a fundamental right to intra[-]state travel.” The Fifth Circuit affirmed the ruling.This Article recommends that when federal courts assess whether there is a constitutional right to intra-state travel, they should embrace the American paradigm of liberty and abandon the antebellum, Southern paradigm of enslavement. Consistent with Professor Derrick Bell’s “interestconvergence” principle, all Americans benefit when the Constitution protects the human rights of the least powerful American.

  6. 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

  7. 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…

  8. 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 “

  9. An Update on Travel Vaccines and Issues in Travel and International Medicine.

    Science.gov (United States)

    Rogers, Bonnie; Bunn, William B; Connor, Bradley A

    2016-08-23

    The fields of travel and international medicine are rapidly changing and growing. The role of occupational and travel health nurses is expanding and should be a focus for the future. At the American Association of Occupational Health Nurses Annual meeting on March 24, 2015, in Boston, five presentations were included in the session, An Update on Travel Vaccines and Issues in Travel and International Medicine. This article summarizes three of the presentations and includes a portion of the information generated by the Centers for Disease Control and Prevention (CDC) included in the fourth presentation. The first section focuses on the Essential Elements of Travel Medicine Programs including the pre-travel care assessment, trip research and risk identification, medication intervention review, non-pharmaceutical and prevention strategies, and post-travel care. The next section is an overview of key issues for business travelers. The growth in the number of international business travelers and unique aspects of business travel are emphasized in a comprehensive travel health program. This section also includes a discussion of expatriates and their special risks identified in recent literature (e.g., an assessment of the significant costs of health events and productivity losses by both business travelers and expatriates). The final section offers a specific example of a vaccine-preventable disease, namely, Japanese encephalitis (JE) virus, and needed changes in JE vaccine recommendations.

  10. Installation position determination of wind speed sensors on steel pole along a high-speed railway

    Institute of Scientific and Technical Information of China (English)

    熊小慧; 梁习锋

    2016-01-01

    In order to consider the influence of steel pole on the measurement of wind speed sensors and determinate the installation position of wind speed sensors, the flow field around wind speed sensors was investigated. Based on the three-dimensional steady Reynolds-averaged Navier-Stokes equations andk-ε double equations turbulent model, the field flow around the wind speed sensor and the steel pole along a high-speed railway was simulated on an unstructured grid. The grid-independent validation was conducted and the accuracy of the present numerical simulation method was validated by experiments and simulations carried out by previous researchers. Results show that the steel pole has a significant influence on the measurement results of wind speed sensors. As the distance between two wind speed sensors is varied from 0.3 to 1.0 m, the impact angles are less than ±20°, it is proposed that the distance between two wind speed sensors is 0.8 m at least, and the interval between wind speed sensors and the steel pole is more than 1.0 m with the sensors located on the upstream side.

  11. Regulation of stroke pattern and swim speed across a range of current velocities: Diving by common eiders wintering in polynyas in the Canadian Arctic

    NARCIS (Netherlands)

    Heath, J.P.; Gilchrist, H.G.; Ydenberg, R.C.

    2006-01-01

    Swim speed during diving has important energetic consequences. Not only do costs increase as drag rises non-linearly with increasing speed, but speed also affects travel time to foraging patches and therefore time and energy budgets over the entire dive cycle. However, diving behaviour has rarely be

  12. A Vehicle Traveling Time Prediction Method Based on Grey Theory and Linear Regression Analysis

    Institute of Scientific and Technical Information of China (English)

    TU Jun; LI Yan-ming; LIU Cheng-liang

    2009-01-01

    Vehicle traveling time prediction is an important part of the research of intelligent transportation system. By now, there have been various kinds of methods for vehicle traveling time prediction. But few consider both aspects of time and space. In this paper, a vehicle traveling time prediction method based on grey theory (GT) and linear regression analysis (LRA) is presented. In aspects of time, we use the history data sequence of bus speed on a certain road to predict the future bus speed on that road by GT. And in aspects of space, we calculate the traffic affecting factors between various roads by LRA. Using these factors we can predict the vehicle's speed at the lower road if the vehicle's speed at the current road is known. Finally we use time factor and space factor as the weighting factors of the two results predicted by GT and LRA respectively to find the fina0l result, thus calculating the vehicle's travehng time. The method also considers such factors as dwell time, thus making the prediction more accurate.

  13. Travel Times of Later Phases for Transmitting Waves through a Fracturing Westerly Granite Sample under a Triaxial Compressive Condition

    Science.gov (United States)

    Imahori, A.; Kawakata, H.; Hirano, S.; Yoshimitsu, N.; Takahashi, N.

    2015-12-01

    In laboratory, it is well-known that the elastic wave speed varies prior to compression fracture of the rock (e.g., Lockner et al., 1977, JGR). Using an enough number of travel times of elastic wave paths in a sample, we can estimate internal structure of the sample. However, the number of the elastic wave transducers is limited, and only the travel times of the first arrival are available in most experiments. Employing broadband transducers (Yoshimitsu et al., 2014, GRL), later phases become available to be analyzed. In the present study, we conduct a triaxial compressive test at room temperature under a dry condition and a confining pressure of 50 MPa, using a cylindrical Westerly granite sample of 100 mm long by 50 mm in diameter. Eight transducers are attached on the sample surface. One of the transducers is used as a wave source and voltage steps are repeatedly applied to it. The elastic waves passing through the sample are sensed by the other broadband transducers, and recorded at a sampling rate of 20 Msps. P-wave speed is estimated from the travel time of the direct P, and Vp/Vs value is assumed to be the √3 to give S-wave speed. We assume that all wave paths never bend except at the top and bottom surface of the sample. We calculate the travel times of later phases reflected at the top and/or bottom surfaces within 3 times. We collate the calculated travel times with observed waveforms. We can identify the travel time of two phases: single reflection from both top and bottom of the sample. On the other hand, some other observed and calculated phase arrivals do not match with each other. Then, we try to identify some remarkable phases using the calculated travel times of PS and SP converted waves and interfacial waves, taking into consideration of wave speed anisotropy.

  14. On the minimal speed and asymptotics of the wave solutions for the lotka volterra system

    CERN Document Server

    Hou, Xiaojie

    2010-01-01

    e study the minimal wave speed and the asymptotics of the traveling wave solutions of a competitive Lotka Volterra system. The existence of the traveling wave solutions is derived by monotone iteration. The asymptotic behaviors of the wave solutions are derived by comparison argument and the exponential dichotomy, which seems to be the key to understand the geometry and the stability of the wave solutions. Also the uniqueness and the monotonicity of the waves are investigated via a generalized sliding domain method.

  15. Accurate Switched-Voltage voltage averaging circuit

    OpenAIRE

    金光, 一幸; 松本, 寛樹

    2006-01-01

    Abstract ###This paper proposes an accurate Switched-Voltage (SV) voltage averaging circuit. It is presented ###to compensated for NMOS missmatch error at MOS differential type voltage averaging circuit. ###The proposed circuit consists of a voltage averaging and a SV sample/hold (S/H) circuit. It can ###operate using nonoverlapping three phase clocks. Performance of this circuit is verified by PSpice ###simulations.

  16. Spectral averaging techniques for Jacobi matrices

    CERN Document Server

    del Rio, Rafael; Schulz-Baldes, Hermann

    2008-01-01

    Spectral averaging techniques for one-dimensional discrete Schroedinger operators are revisited and extended. In particular, simultaneous averaging over several parameters is discussed. Special focus is put on proving lower bounds on the density of the averaged spectral measures. These Wegner type estimates are used to analyze stability properties for the spectral types of Jacobi matrices under local perturbations.

  17. The Destined Death of the Travelling Salesman

    Institute of Scientific and Technical Information of China (English)

    何苗

    2015-01-01

    Death of a Travelling Salesman is a short story with heated discussion and dispute. Death, as the title of the story presents, has always been the center of criticism. This paper aims to dissect this short story, and to discuss the destined death of the travelling salesman.

  18. OPEN SPACE ALLOCATION AND TRAVEL COSTS

    OpenAIRE

    Kent F. Kovacs

    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.

  19. Travel and the Social Studies Teacher.

    Science.gov (United States)

    Prince, Doris, Ed.

    1985-01-01

    Travel allows teachers to gather the data and realia to enliven history or global education in the classroom. In this special issue teachers describe personal travel experiences to many parts of the globe. Points of interest, itineraries, budgets, and artifacts collected are discussed. (RM)

  20. Tropical diarrhoea: new developments in traveller's diarrhoea.

    Science.gov (United States)

    Lima, A A

    2001-10-01

    Traveller's diarrhoea is the most common illness acquired by visitors to developing countries, affecting 20-50% of the 35 million people who travel from industrialized countries each year. Important risk factors include point of origin and destination of the traveller, host factors, and exposure to contaminated food and water. The most common causes of traveller's diarrhoea in adults in developing countries include infection with Escherichia coli, Shigella spp., Salmonella spp., Campylobacter spp., Vibrio parahaemolyticus (in Asia), rotavirus (in Latin America), and protozoa (Giardia, Cryptosporidium and Cyclospora spp., and Entamoeba histolytica). No pathogen is identified in over half of patients with traveller's diarrhoea, however. The primary objectives of treatment of traveller's diarrhoea are to reduce the symptoms and duration of diarrhoeal illness, to reduce inconvenience caused by such illness and to prevent cancellation of planned activities. These important objectives are best accomplished by empirical self-therapy with a combination of antimicrobial agents and loperamide. Since the first use of ciprofloxacin, fluoroquinolones have become the drugs of choice in empirical therapy for moderate-to-severe traveller's diarrhoea in adults. The options for children include nalidixic acid, trimethoprim-sulfamethoxazole (along with erythromycin if Campylobacter infection is a possibility) and furazolidone. Education on hygiene and safe food preparation help to prevent many diarrhoeal diseases, including traveller's diarrhoea.

  1. 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.

  2. Travel-Study as Learning in Sociology.

    Science.gov (United States)

    Forster, Brenda; Prinz, Andrew K.

    1988-01-01

    Discusses the objectives, characteristics, and outcomes associated with a joint "sociology-urban studies, travel-study, minicourse program." Describes how students in a four-day, two-credit-hour course travel to cities such as Washington, DC and Toronto to be exposed to different cultures, organizational structures, and social arrangements.…

  3. Traveling Policies: Hijacked in Central Asia

    Science.gov (United States)

    Silova, Iveta

    2005-01-01

    Since the collapse of the Soviet Union, Central Asian education reform discourses have become increasingly similar to distinctive Western policy discourses traveling globally across national boundaries. Tracing the trajectory of "traveling policies" in Central Asia, this article discusses the way Western education discourses have been…

  4. 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

  5. Traveling Policies: Hijacked in Central Asia

    Science.gov (United States)

    Silova, Iveta

    2005-01-01

    Since the collapse of the Soviet Union, Central Asian education reform discourses have become increasingly similar to distinctive Western policy discourses traveling globally across national boundaries. Tracing the trajectory of "traveling policies" in Central Asia, this article discusses the way Western education discourses have been hybridized…

  6. International travel and the elite athlete.

    Science.gov (United States)

    Pipe, Andrew L

    2011-01-01

    International travel is a frequent occurrence in the life of the elite athlete; such travel can pose challenges to the sport medicine practitioner. Travel is also the reality of many recreational level or sub-elite athletes as opportunities for international competition and training proliferate. An appreciation of the range of responsibilities associated with the preparation for and the strategies to facilitate such travel is essential for any physician charged with the care of athletes and teams. An appreciation of (1) the medical and public health challenges associated with competition in a particular setting; (2) the requirements for vaccination and immunization; (3) the strategies for the management of jet lag and climatic or environmental extremes; (4) the range of supplies and equipment necessary for travel to certain locales; (5) the need to ensure the availability of ample familiar and nutritious foods; (6) the potential need for specialty care in strange settings; (7) the management of common travel-associated illness; and (8) the challenges associated with the evacuation of an injured athlete are fundamental to the successful management of international travel involving athletes and teams. The adoption of a methodical approach to pre-trip planning can ensure an enhanced travel experience, illness-free training and competition, and facilitate optimal performance.

  7. 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.

  8. 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.

  9. A steady-state saturation model to determine the subsurface travel time (STT in complex hillslopes

    Directory of Open Access Journals (Sweden)

    T. Sabzevari

    2010-06-01

    Full Text Available The travel time of subsurface flow in complex hillslopes (hillslopes with different plan shape and profile curvature is an important parameter in predicting the subsurface flow in catchments. This time depends on the hillslopes geometry (plan shape and profile curvature, soil properties and climate conditions. The saturation capacity of hillslopes affect the travel time of subsurface flow. The saturation capacity, and subsurface travel time of compound hillslopes depend on parameters such as soil depth, porosity, soil hydraulic conductivity, plan shape (convergent, parallel or divergent, hillslope length, profile curvature (concave, straight or convex and recharge rate to the groundwater table. An equation for calculating subsurface travel time for all complex hillslopes was presented. This equation is a function of the saturation zone length (SZL on the surface. Saturation zone length of the complex hillslopes was calculated numerically by using the hillslope-storage kinematic wave equation for subsurface flow, so an analytical equation was presented for calculating the saturation zone length of the straight hillslopes and all plan shapes geometries. Based on our results, the convergent hillslopes become saturated very soon and they showed longer SZL with shorter travel time compared to the parallel and divergent ones. The subsurface average flow rate in convergent hillslopes is much less than the divergent ones in the steady state conditions. Concerning to subsurface travel time, convex hillslopes have more travel time in comparison to straight and concave hillslopes. The convex hillslopes exhibit more average flow rate than concave hillslopes and their saturation capacity is very low. Finally, the effects of recharge rate variations, average bedrock slope and soil depth on saturation zone extension were investigated.

  10. 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...

  11. 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...

  12. What documents should a foreigner hold for traveling in Tibet

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Applying for alien's travel permit: Before start your trip to Tibet, you need to contact with travel agency in Tibet through local counterpart, providing them with your traveling date, travel route, purpose of travel, name,passport number, vocation, the name of your working place and your address. You will receive answer from Tibet side quickly。

  13. Average-Time Games on Timed Automata

    OpenAIRE

    Jurdzinski, Marcin; Trivedi, Ashutosh

    2009-01-01

    An average-time game is played on the infinite graph of configurations of a finite timed automaton. The two players, Min and Max, construct an infinite run of the automaton by taking turns to perform a timed transition. Player Min wants to minimise the average time per transition and player Max wants to maximise it. A solution of average-time games is presented using a reduction to average-price game on a finite graph. A direct consequence is an elementary proof of determinacy for average-tim...

  14. Grassmann Averages for Scalable Robust PCA

    DEFF Research Database (Denmark)

    Hauberg, Søren; Feragen, Aasa; Black, Michael J.

    2014-01-01

    arbitrarily corrupt the results. Unfortunately, state-of-the-art approaches for robust PCA do not scale beyond small-to-medium sized datasets. To address this, we introduce the Grassmann Average (GA), which expresses dimensionality reduction as an average of the subspaces spanned by the data. Because averages...... to vectors (subspaces) or elements of vectors; we focus on the latter and use a trimmed average. The resulting Trimmed Grassmann Average (TGA) is particularly appropriate for computer vision because it is robust to pixel outliers. The algorithm has low computational complexity and minimal memory requirements...

  15. Decomposing variations of geopotential height in the troposphere and stratosphere into stationary and travelling waves

    Science.gov (United States)

    Guryanov, Vladimir; Eliseev, Alexey

    2016-07-01

    The ERA-Interim geopotential height in the Northern Hemisphere from November to March, 1992-2015 in the layer from between pressure levels 1000 mb and 1 mb is expanded into stationary and travelling zonal waves with zonal wavenumbers, k, from 1 to 10, and with periods, T, from 2 to 156 days (the so called Hayashi spectra). Among the studied waves, the largest amplitude is attained by the stationary and travelling waves with zonal wavenumber k=1 and with periods from 3 to 4 weeks in the upper stratosphere over the latitudinal belt 60-70oN. The stationary waves with k from 1 to 3 and with T from 2 to 3 weeks are most pronounced in the stratosphere. In turn, the largest amplitudes of the travelling waves with zonal wavenumbers k ≥ 5 are found in the troposphere. The dominant periods of the latter waves are about 1 week or slightly higher, and this dominant period basically decrease with increasing wavenumber. In the upper stratosphere, the eastward travelling waves generally dominate over westward ones. The only exception is the longest zonal mode with k=1, for which the amplitude of the westward travelling wave is larger than that for the eastward one. The period of the travelling waves dominating in the upper stratosphere is close to 3 weeks. In the upper troposphere, the amplitudes of the eastward waves with k from 4 to 10 is several-fold larger than those for their westward counterparts. The latter is reflected in the larger average wavenumber of the eastward travelling wave in comparison to that of the westarward one. The period of the gravest of the dominant travelling waves in the upper troposphere is close to one week, and it decreases to 2-4 days for the dominant travelling waves with k=8-10.

  16. 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...... a downward tendency with higher density. The resulting immobile share is very dependent on data collection methodology, sampling method, quality of interviewer felt-work etc. The paper shows other possibilities to improve local surveys based on comparison with other countries. Background In...

  17. Limitations of typhoid vaccination for travellers.

    Science.gov (United States)

    Stephen, J; Mara, N; Nathwani, D

    1996-12-01

    Around one-third of travellers to endemic areas receive pre-travel typhoid vaccination, increasingly with the new parenteral vaccination Typhim Vi (Mérieux). More than 200 cases of Salmonella typhi and S. paratyphi infection are imported into the UK each year. Despite the widespread use of immunisation, non-specialist clinicians and the travelling public do not appear to fully appreciate the limitations of currently available vaccination. These limitations are not adequately highlighted in either the Green Book of Immunisation against Infectious Diseases (HMSO, 1992) or the new handbook Health Information for Overseas Travel (HMSO, 1995) which are important sources of reference for clinicians and practice nurses. This may delay consideration of diagnosis and presentation for treatment in immunised travellers.

  18. Health precautions for travelers to Mexico.

    Science.gov (United States)

    Peate, W F; Pust, R E

    1985-03-01

    After Canada, Mexico is the most popular destination for Americans traveling outside the United States. As a developing country, Mexico presents numerous health hazards to American visitors, including the prevalent travelers' diarrhea (turista), from which 40% will suffer, and the less common typhoid, dengue, rabies, malaria, taeniasis, cysticercosis, and trichinosis. Environmental hazards, including sun, heat, high altitude, motion sickness, and accidents, also threaten the unwary traveler. In the event of illness or injury, Americans may find medical facilities unfamiliar and less well equipped than those in the United States. Utilizing both an individualized risk assessment for each traveler and readily available references, physicians, in partnership with local public health agencies, can develop comprehensive preventive health plans for their patients traveling to Mexico.

  19. Gas speed flow transducer

    Directory of Open Access Journals (Sweden)

    Godovaniouk V. N.

    2011-08-01

    Full Text Available The design of a gas speed flow transducer using the coupling of gas speed and heat streams within the transducer itself is proposed. To maintain the heat balance between two thermoresistors under gas stream at different temperatures, it provides energy consumption monitoring. The detailed combined planar technology for the transducer production is presented. The worked-out measurement procedure allows to make measurements in the temperature range. Information enough to organize production of cheap, reliable and precise gas speed flow transducers is given.

  20. Improvement on Transportation Safety on Bus by Installing A Speed Limiter in Conventional Engine to Reduce Speed Rate

    Directory of Open Access Journals (Sweden)

    Pranoto Hadi

    2016-01-01

    Full Text Available Driving is one of the conditions when the driver should be given special attention to make the motor vehicle in driving way and the driver should be in a good condition. However, the problem is in a certain condition the driver lost their control speed due to their target and minimize the driving time and it led the high potential to accident. Therefore, speed limiter which applied in the bus is urgently needed to reduce the accident and improve their awareness of road safety. Developed speed limiter is completed by fuel cut-off system to prevent the engine and maintain the speed. Limitation of speed be adapted by government regulation. From the results show that the highest and average speed of 136 km/h and 123.5 km/h is observed by bus speed prior to use speed limiter. After speed limiter applied in the bus, the approved maximum speed is 90 km/h. Those data approve that the speed limiter can reduce 83% from the top speed before speed limiter applied.

  1. The Impact of Reviews and Average Rating on Hotel-Booking-Intention: A Qualitative Study

    DEFF Research Database (Denmark)

    Buus, Line Thomassen; Jensen, Charlotte Thodberg; Jessen, Anne Mette Karnøe

    2016-01-01

    User-generated information types (ratings and reviews) are highly used when booking hotel rooms on Online Travel Agency (OTA) websites. The impact of user-generated information on decision-making is often investigated through quantitative research, thereby not examining in depth how and why...... travelers use this information. This paper therefore presents a qualitative study conducted to achieve a deeper understanding. We investigated the use of reviews and average rating in a hotel-booking-context through a laboratory experiment, which involved a task of examining a hotel on a pre-designed OTA...... website followed by an interview. We processed the data from the interview, and the analysis resulted in a model generalizing the use of reviews and average rating in the deliberation phase of a hotel-booking. The findings are overall consistent with related research. Yet, beyond this, the qualitative...

  2. Model-based Integration of Past & Future in TimeTravel

    DEFF Research Database (Denmark)

    Khalefa, Mohamed E.; Fischer, Ulrike; Pedersen, Torben Bach

    2012-01-01

    We demonstrate TimeTravel, an efficient DBMS system for seamless integrated querying of past and (forecasted) future values of time series, allowing the user to view past and future values as one joint time series. This functionality is important for advanced application domain like energy....... The main idea is to compactly represent time series as models. By using models, the TimeTravel system answers queries approximately on past and future data with error guarantees (absolute error and confidence) one order of magnitude faster than when accessing the time series directly. In addition...... it to answer approximate and exact queries. TimeTravel is implemented into PostgreSQL, thus achieving complete user transparency at the query level. In the demo, we show the easy building of a hierarchical model index for a real-world time series and the effect of varying the error guarantees on the speed up...

  3. Traveling wave solutions for epidemic cholera model with disease-related death.

    Science.gov (United States)

    Zhang, Tianran; Gou, Qingming

    2014-01-01

    Based on Codeço's cholera model (2001), an epidemic cholera model that incorporates the pathogen diffusion and disease-related death is proposed. The formula for minimal wave speed c (∗) is given. To prove the existence of traveling wave solutions, an invariant cone is constructed by upper and lower solutions and Schauder's fixed point theorem is applied. The nonexistence of traveling wave solutions is proved by two-sided Laplace transform. However, to apply two-sided Laplace transform, the prior estimate of exponential decrease of traveling wave solutions is needed. For this aim, a new method is proposed, which can be applied to reaction-diffusion systems consisting of more than three equations.

  4. Traveling Wave Solutions for Epidemic Cholera Model with Disease-Related Death

    Directory of Open Access Journals (Sweden)

    Tianran Zhang

    2014-01-01

    Full Text Available Based on Codeço’s cholera model (2001, an epidemic cholera model that incorporates the pathogen diffusion and disease-related death is proposed. The formula for minimal wave speed c∗ is given. To prove the existence of traveling wave solutions, an invariant cone is constructed by upper and lower solutions and Schauder’s fixed point theorem is applied. The nonexistence of traveling wave solutions is proved by two-sided Laplace transform. However, to apply two-sided Laplace transform, the prior estimate of exponential decrease of traveling wave solutions is needed. For this aim, a new method is proposed, which can be applied to reaction-diffusion systems consisting of more than three equations.

  5. Shallow-water acoustic tomography from angle measurements instead of travel-time measurements.

    Science.gov (United States)

    Aulanier, Florian; Nicolas, Barbara; Mars, Jérôme I; Roux, Philippe; Brossier, Romain

    2013-10-01

    For shallow-water waveguides and mid-frequency broadband acoustic signals, ocean acoustic tomography (OAT) is based on the multi-path aspect of wave propagation. Using arrays in emission and reception and advanced array processing, every acoustic arrival can be isolated and matched to an eigenray that is defined not only by its travel time but also by its launch and reception angles. Classically, OAT uses travel-time variations to retrieve sound-speed perturbations; this assumes very accurate source-to-receiver clock synchronization. This letter uses numerical simulations to demonstrate that launch-and-reception-angle tomography gives similar results to travel-time tomography without the same requirement for high-precision synchronization.

  6. Wind_Speeds_Master

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set included wind speeds for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came from...

  7. Speeding up Transportation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 2007 was an excellent year for the transportation industry, marked by high speed railway transportation, development of the national expressway network and launch of the Chang'e lunar probe satellite.

  8. Averaged null energy condition and quantum inequalities in curved spacetime

    CERN Document Server

    Kontou, Eleni-Alexandra

    2015-01-01

    The Averaged Null Energy Condition (ANEC) states that the integral along a complete null geodesic of the projection of the stress-energy tensor onto the tangent vector to the geodesic cannot be negative. ANEC can be used to rule out spacetimes with exotic phenomena, such as closed timelike curves, superluminal travel and wormholes. We prove that ANEC is obeyed by a minimally-coupled, free quantum scalar field on any achronal null geodesic (not two points can be connected with a timelike curve) surrounded by a tubular neighborhood whose curvature is produced by a classical source. To prove ANEC we use a null-projected quantum inequality, which provides constraints on how negative the weighted average of the renormalized stress-energy tensor of a quantum field can be. Starting with a general result of Fewster and Smith, we first derive a timelike projected quantum inequality for a minimally-coupled scalar field on flat spacetime with a background potential. Using that result we proceed to find the bound of a qu...

  9. Police enforcement and driving speed.

    NARCIS (Netherlands)

    2008-01-01

    Speed limits are violated frequently in the Netherlands. As speed is an important factor in road crashes, the surveillance of driving speeds is one of the spearheads in the policy plans of the Dutch police. Different methods of speed enforcement have proved to be effective in reducing speed and cras

  10. 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 Eur

  11. Travels with the Fossil Hunters

    Science.gov (United States)

    Whybrow, Peter J.

    2000-04-01

    Whether dodging bullets in West Africa, or rabid dogs in Pakistan, surviving yak-butter tea in Tibet, or eating raw fish in China, the life of a globe-trotting fossil hunter is often hazardous and always filled with surprises. Travels with the Fossil Hunters lets readers share the wonder, joys of discovery, and excitement of these intrepid scientists. Packed with more than 100 beautiful, full-color photographs, the volume takes readers on twelve expeditions to remote parts of the world in search of diverse fossil remains, from those of dinosaurs to human ancestors. Each expedition by paleontologists from London's Natural History Museum reveals the problems and challenges of working in extreme conditions, from the deserts of the Sahara and Yemen to the frozen wastes of Antarctica, from the mountains of India to the forests of Latvia. Along the way they also describe the paleontology and geology of the countries they visit and the scientific reasons for their expeditions. With a foreword from Sir David Attenborough and an introduction from Richard Fortey, this fascinating book will appeal to amateur and professional fossil hunters alike and to readers interested in accounts of exotic locales. Peter Whybrow is a research scientist at the Natural History Museum, London. His research interests include Arabian Miocene vertebrates, paleoclimates, paleogeography, and biotic diversity. He is senior editor with A. Hill of Fossil Vertebrates of Arabia (Yale University Press, New Haven, 1999).

  12. WIDTHS AND AVERAGE WIDTHS OF SOBOLEV CLASSES

    Institute of Scientific and Technical Information of China (English)

    刘永平; 许贵桥

    2003-01-01

    This paper concerns the problem of the Kolmogorov n-width, the linear n-width, the Gel'fand n-width and the Bernstein n-width of Sobolev classes of the periodicmultivariate functions in the space Lp(Td) and the average Bernstein σ-width, averageKolmogorov σ-widths, the average linear σ-widths of Sobolev classes of the multivariatequantities.

  13. 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.

  14. 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.

  15. NOAA Average Annual Salinity (3-Zone)

    Data.gov (United States)

    California Department of Resources — The 3-Zone Average Annual Salinity Digital Geography is a digital spatial framework developed using geographic information system (GIS) technology. These salinity...

  16. Stochastic averaging of quasi-Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    朱位秋

    1996-01-01

    A stochastic averaging method is proposed for quasi-Hamiltonian systems (Hamiltonian systems with light dampings subject to weakly stochastic excitations). Various versions of the method, depending on whether the associated Hamiltonian systems are integrable or nonintegrable, resonant or nonresonant, are discussed. It is pointed out that the standard stochastic averaging method and the stochastic averaging method of energy envelope are special cases of the stochastic averaging method of quasi-Hamiltonian systems and that the results obtained by this method for several examples prove its effectiveness.

  17. On weakly singular and fully nonlinear travelling shallow capillary-gravity waves in the critical regime

    CERN Document Server

    Mitsotakis, Dimitrios; Assylbekuly, Aydar; Zhakebaev, Dauren

    2016-01-01

    In this Letter we consider long capillary-gravity waves described by a fully nonlinear weakly dispersive model. First, using the phase space analysis methods we describe all possible types of localized travelling waves. Then, we especially focus on the critical regime, where the surface tension is exactly balanced by the gravity force. We show that our long wave model with a critical Bond number admits stable travelling wave solutions with a singular crest. These solutions are usually referred to in the literature as peakons or peaked solitary waves. They satisfy the usual speed-amplitude relation, which coincides with Scott-Russel's empirical formula for solitary waves, while their decay rate is the same regardless their amplitude. Moreover, they can be of depression or elevation type independent of their speed. The dynamics of these solutions are studied as well.

  18. International Marketing & Relations of MATKA Travel Fair in Helsinki

    OpenAIRE

    Kharel, Suraj

    2015-01-01

    This Bachelor’s thesis was done in order to know about the international marketing and atmosphere of MATKA Nordic Travel Fair in Helsinki. The topic of this thesis International Marketing & Relations of MATKA Travel Fair in Helsinki itself is an interesting topic. It shows how international atmosphere and marketing is done in MATKA Nordic Travel Fair and international atmosphere in MATKA Nordic Travel Fair. The MATKA Nordic Travel Fair in Helsinki is only one of the biggest travel fair in Fin...

  19. Naturalistic speeding data: Drivers aged 75 years and older

    Directory of Open Access Journals (Sweden)

    Anna Chevalier

    2016-09-01

    Full Text Available The data presented in this article are related to the research article entitled “A longitudinal investigation of the predictors of older drivers׳ speeding behavior” (Chevalier et al., 2016 [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75–94 years (median 80 years, 52% male living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.

  20. Naturalistic speeding data: Drivers aged 75 years and older.

    Science.gov (United States)

    Chevalier, Anna; Chevalier, Aran John; Clarke, Elizabeth; Wall, John; Coxon, Kristy; Brown, Julie; Ivers, Rebecca; Keay, Lisa

    2016-09-01

    The data presented in this article are related to the research article entitled "A longitudinal investigation of the predictors of older drivers׳ speeding behavior" (Chevalier et al., 2016) [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75-94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS) data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.