under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract In this paper, we give an a posteriori error estimates with constitutive law for some obstacle problem. The error estimator involves some parameter ε appeared in some penalized equation.

Degradation is a common problem for polymer matrix composites (PMCs) under low thermal cycling conditions. This paper investigates the effects of low thermal cycling on total mass loss (TML) and surface degradation of PMCs. Unnotched and open-hole specimens were weighed before and after low thermal cycling. The total mass loss and surface degradation of the specimens were studied over 250 cycle...

The aim of a soccer game is to score more goals than the opponent does. The chances of doing so increase when all the own players are continuously present on the field. In the RoboCup Standard Platform League (SPL), the only reasons for players not to participate in a game are that they either have been penalized or they have not been ready for the match in the first place. This paper presents ...

In recent years mobile networks have expanded dramatically, compared with other wireless networks. Routing protocols in these networks are designed with the assumption that there is no attacker node, so routing protocols are vulnerable to various attacks in these networks. In this paper, we review the network layer attacks and then we simulate the impact of black hole attack on ad hoc on demand...

An obstacle representation of a graph consists of a set of polygonal obstacles and a distinct point for each vertex such that two points see each other if and only if the corresponding vertices are adjacent. Obstacle representations are a recent generalization of classical polygon–vertex visibility graphs, for which the characterization and recognition problems are long-standing open questions....

A mobile robot system, capable of performing various tasks for the physically disabled, has been developed. To avoid collision with unexpected obstacles, the mobile robot uses ultrasonic range finders for detection and mapping. The obstacle avoidance strategy used for this robot is described. Since this strategy depends heavily on the performance of the ultrasonic range finders, these sensors a...

rectangular waveguide (wr) is one of the earliest types of transmission lines. rectangular waveguide can be produced by hot extrusion process. in this paper, the hot extrusion process of cuzn5 rectangular waveguide was investigated by finite element method (fem). in addition, genetic algorithm method (ga) was used to optimize the die geometry and process conditions to achieve the lowest magnitu...

As drones and autonomous cars become more widespread it is becoming increasingly important that robots can operate safely under realistic conditions. The noisy information fed into real systems means that robots must use estimates of the environment to plan navigation. Efficiently guaranteeing that the resulting motion plans are safe under these circumstances has proved difficult. We examine ho...

Autonomous flight in confined or cluttered environments such as houses or urban canyons requires high manoeuvrability, fast mapping from sensors to actuators and very limited overall system weight. Although flying animals are well capable of solving this problem, roboticists have difficulties at reproducing such capabilities. This paper describes why and how we took inspiration from flying inse...