No abstract

As a result of the imprecise positioning accuracy, the satellite-based positioning system cannot offer the reliable and continuous positioning service for vehicular active safety application or vehicle monitoring in urban center with dense buildings or underground. With the advent of Vehicle Ad hoc Network (VANET), the Roadside Unit (RSU) can be considered as an anchor or base station to offer positioning reference. The ground-based positioning solution can help us acquire more precise position information through many times interaction, but multiple communications will result in heavy burden for network and more energy consumption. In this paper, we firstly analyze the pros and cons of representative algorithm, i.e., Symmetric Double SideTwo way Ranging (SDS-TWR). Then, we propose a novel energy-saving One-Sided Synchronous Two-Way Ranging (OSS-TWR) algorithm to reduce the communication times, which gains lower energy consumption and better performance than SDS-TWR. The experiments verify the validity of our solution. Finally, we make a conclusion and discuss the future works of vehicular positioning.

The optimization of facility-based systems is considered. First, the congestion game is converted into a matrix form, so that the matrix approach is applicable. Then, a facilitybased system with a system performance criterion is considered. A necessary and sufficient condition is given to assure that the system is convertible into a congestion game with the given system performance criterion as its potential function by designing proper facility-cost functions. Using this technology, for a dynamic facility-based system the global optimization may be reached when each agent optimizes its payoff functions. Finally, the approach is extended to those systems which are partly or nearly convertible.

This paper investigates the stability of (switched) polynomial systems. Using semi-tensor product of matrices, the paper develops two tools for testing the stability of a (switched) polynomial system. One is to convert a product of multi-variable polynomials into a canonical form, and the other is an easily verifiable sufficient condition to justify whether a multi-variable polynomial is positive definite. Using these two tools, the authors construct a polynomial function as a candidate Lyapunov function and via testing its derivative the authors provide some sufficient conditions for the global stability of polynomial systems.