The value of travel time savings (VTTS) is the monetary value attached to save a determined amount of travel time. VTTS is also the most important benefit category aimed at justifying investments in transport infrastructures by public administrations. Hence VTTS played a significant role in various economic studies, both analytical and empirical (Zamparini & Reggiani, 2007). "It is difficult to...

Offset surfaces play an important role in various CAD/CAM applications. Given a set of oriented points, we propose a hierarchical method in this paper to fit both the zero-level surface and its offset surface with a single implicit function. The implicit function is formed by compactly supported radial basis functions (CSRBFs). Different from other existing methods in literature, our approach r...

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...

An e,;perimental technique for the investigation of the behaviour of acoustic wave propagation through a turbulent medium is discussed. The present study utilizes the ultrasonic travel-time technique to di­ agnose a grid-generated turbulence. Travel-time variance is studied versus mean Dow velocity. travel distance and outer turbulence scale. The effect of therma.l fluctuations. which result in...

Ryan M. Eustice Department of Naval Architecture and Marine Engineering, University of Michigan, Ann Arbor, Michigan 48109 e-mail: [email protected] Hanumant Singh Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543 e-mail: [email protected] Louis L. Whitcomb Department of Mechanical Engineering, Johns Hopkins University, Baltim...

We describe our development of a road traffic CA (Cellular Automata) model of the four most common types of 4-way intersection (Yield-controlled intersections, Stop-controlled intersections, Signal-controlled intersections, and Roundabout-based intersection). We developed this model to study how these four different types of 4-way intersection affect road traffic flow and congestion in general ...

This paper reports the formulation and evaluation of a centralized extended Kalman filter designed for a novel navigation system for underwater vehicles. The navigation system employs Doppler sonar, depth sensors, synchronous clocks, and acoustic modems to achieve simultaneous acoustic communication and navigation. The use of a single moving reference beacon eliminates the requirement for the u...

This paper describes the use of orthogonal space-time block codes to overcome the performance and complexity difficulties associated with the use of Shaped Offset QPSK (SOQPSK) modulation, a ternary continuous phase modulation (CPM), in multiple-input multiple-output telemetry systems. The orthogonal space-time block code is applied to SOQPSK waveforms in the same way it would be applied to sym...