We present a model of directed communication network with endogenous link strength. Agents are endowed with a fixed amount of resource which they can distribute over links. They obtain indirect benefit by the path maximizing the product of link strength. In this environment, the wheel architecture is shown to be not only the unique efficient architecture but also the unique Nash architecture. J...

A small-scale laboratory apparatus was built to study liquid friction modifier (LFM) behavior in a top-of-rail application. field experiment also carried out complement the findings. KELTRACK® (a water-based LFM) used as test fluid. Laser-induced fluorescence served measure LFM thickness left on track after passage of wheel. The lab experiments show that cannot withstand high wheel-rail contact...

Summary We propose a new unit root test for stationary null hypothesis H0 against alternative H1. Our approach is nonparametric as only assumes that the process concerned I(0) without specifying any parametric forms. The based on fact sample autocovariance function converges to finite population an while it diverges infinity with roots. Therefore rejects large values of function. To address tec...

Sharp large deviation estimates for stochastic differential equations with small noise, based on minimizing the Freidlin-Wentzell action functional under appropriate boundary conditions, can be obtained by integrating certain matrix Riccati along minimizers or instantons, either forward backward in time. Previous works this direction often rely existence of isolated positive definite second var...

This paper deals with Epi.q, a family of mobile robots whose main characteristic is a wheel-legged hybrid locomotion. These multi-purpose robots can be successfully exploited for security and surveillance tasks. The document presents state of the art security robotics, the Epi.q mechanical architecture, the concept behind the robot driving unit, three prototypes and the design of a new one.

Unstructured off-road environments with complex terrain obstacles and pavement properties bring obvious challenges for special purpose autonomous vehicle control. A cascade direct yaw moment control strategy (CDYC), which contains a main loop servo loop, is proposed to enhance the accuracy stability of an independent eight in-wheel motor-driven rear-wheel steering (8WD/RWS). In double PID contr...