This thesis is about wireless multi-hop networks such as wireless sensors networks or hybrid sensor/actuator networks and actuator networks. Those kinds of networks are composed of independent entities (nodes, i.e. the robots) which have very limited computing and memory capabilities. Moreover, they are battery powered and have to work in an efficient way. They communicate through the radio med...

— In Geographic Routing protocols (e.g. GPSR), a node makes packet forwarding decisions based on the coordinates of its neighbors and the packet’s destination. Geo-routing uses greedy forwarding as a default; if this fails (e.g. the packet is trapped in a dead end caused by holes and/or obstacles), a recovery scheme based on perimeter routing is invoked. This however often leads to degraded per...

background: regarding to the significant of the possibility of the malaria epidemic and nuisance of mosquitoes dur­ing the active season, the fauna and some ecological activities of mosquitoes in related to tree holes were investi­gated from april to december 2009 in neka county of mazandaran province, northern iran. methods: larval collection was carried out from natural, artificial breeding p...

We consider two optimization problems with geometric structures The rst one con cerns the following minimization problem termed as the rectilinear polygon cover problem Cover certain features of a given rectilinear polygon possibly with rectilinear holes with the minimum number of rectangles included in the polygon Depending upon whether one wants to cover the interior boundary or corners of th...

In this paper, we combat the problem of performance optimization in wireless sensor networks. Specifically, a novel framework is proposed to handle two major research issues. Firstly, we optimize the utilization of resources available to various nodes at hand. This is achieved via proposed optimal network clustering enriched with layer-adaptive 3-tier communication mechanism to diminish energy ...

As more and more real Wireless Sensor Network’s (WSN) applications have been tested and deployed over the last five years, the research community of WSN realises that several issues need to be revisited from practical angles, such as reliability and security. In this paper, we address the reliability issue by designing a general energy-efficient, load balanced, fault-tolerant and scalable routi...

Nowadays, since wireless sensor networks (WSN)s are increasingly being used in challenged environments such as underground mines, tunnels, oceans and the outer space, fault-tolerance need has become a major requirement for routing protocols. So far, the proposed fault-tolerance methods or algorithms aim to recover the isolated failures which occur different parts of the network in different tim...

Wireless sensor networks (WSNs) consist of a large collection of small nodes providing collaborative and distributed sensing ability in unpredictable environments. Given their unattended nature, it is important for the routing algorithm in WSN to deal well with the node failures, resource depletion, and other abnormality. In this paper, an information-driven task routing (IDTR) is introduced fo...

Abstract A quest for geographic routing schemes of wireless sensor networks when nodes are deployed in areas with obstacles has resulted numerous ingenious proposals and techniques. However, there is a lack solutions complicated cases wherein the source or sink located close to specific hole, especially cavern-like regions large complex-shaped holes. In this paper, we propose scheme deal existe...