015504-1 The shear wave speed is an upper limit for the speed of cracks loaded in tension in linear elastic solids. We have discovered that in a nonlinear material, cracks in tension (mode I) exceed this sound speed and travel in an intersonic range between shear and longitudinal wave speeds. The experiments are conducted in highly stretched sheets of rubber; intersonic cracks can be produced s...

We study a simple geometric model of transportation facility that consists of two points between which the travel speed is high. This elementary definition can model shuttle services, tunnels, bridges, teleportation devices, escalators or moving walkways. The travel time between a pair of points is defined as a time distance, in such a way that a customer uses the transportation facility only i...

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. Classicall...

We examine sequential spatial pattern formation in a tissue interaction model for skin organ morphogenesis. Pattern formation occurs as a front sweeps across the domain leaving in its wake a steady state spatial pattern. Extensive numerical simulations show that these fronts travel with constant wave speed. By considering the envelope of the solution profile we present a novel method of calcula...

1 October 2004 is the 40th anniversary of the opening of the Tokaido Shinkansen, the world’s first high-speed railway that marked the start of the era of high-speed rail travel. Ten years ago, the October issue of JRTR 3 published a special feature entitled 30 Years of High Speed Railways. This article summarizes the events in highspeed railways in the last 10 years and discusses their future p...

One of the ways to define mobility in a transportation system is total travel time for all travelers using the transportation network. A good assessment of the mobility is essential for knowing the points of congestion in the network and the factors responsible for the congestion. Also the change in mobility from the baseline to the horizon year would give the modeler an idea of the effectivene...

the velocity data of seismic waves in a region has an important role in locating occurred events. information such as velocity ratio of vp/vs and velocity curves for pg, pn, sg, and sn phases directly affect the locating results. it is well known that the vp/vs ratio can be used to predict lithology, and that s-waves are sensitive to microcracks aligned by the present day stress field. also, th...

Travel speed is a key measure of effectiveness for evaluating urban arterials. The Highway Capacity Manual (HCM) methodology of predicting speeds along urban streets requires complex calculations and input not typically available in long-range planning, thereby requiring the use of default values. This paper demonstrates that a simple and practical method of estimating travel speed along urban ...

exhaust emissions contribute greatly to air pollution, the social cost of which may occur as danger to human health, attracting huge medical expenses, causing absenteeism and hence loss of productivity. these are incentives to reduce exhaust emissions to the barest minimum. two major cities in ghana, accra and kumasi, are struck by vehicular traffic jams especially during rush-hours and are gra...

Desert ants, Cataglyphis, use path integration as a major means of navigation. Path integration requires measurement of two parameters, namely, direction and distance of travel. Directional information is provided by a celestial compass, whereas distance measurement is accomplished by a stride integrator, or pedometer. Here we examine the recently demonstrated pedometer function in more detail....