Many real-world systems involve distributed and selfish agents who optimize their own objective function. In these systems, we need to design efficient mechanisms so that system-wide objective is optimized despite agents acting in their own self interest. In this thesis, we develop approximation algorithms and decentralized mechanisms for various combinatorial optimization problems in such syst...

In the classical facility location problemwe are given a set of facilities, with associated opening costs, and a set of clients. The goal is to open a subset of facilities, and to connect each client to the closest open facility, so that the total connection and opening cost is minimized. In some applications, however, open facilities need to be connected via an infrastructure. Furthermore, con...

Wireless Sensor Networks (WSNs) can be defined as a self-configured and infrastructureless wireless networks to monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants and to cooperatively pass their data through the network to a main location or sink where the data can be observed and analysed. A sink or base station acts like an inte...

a sensor network is made up of a large number of sensors with limited energy. sensors collect environmental data then send them to the sink. energy efficiency and thereby increasing the lifetime of sensor networks is important. direct transfer of the data from each node to the central station will increase energy consumption. previous research has shown that the organization of nodes in cluster...

In recent years, the maximization of a lifetime for wireless sensor networks is considered an important area researchers. The (WSNs) contain two types sensors that called nodes and sink which node send information to central (sink node) collected its data. Choosing best location critical problem faces networks. this paper, we propose method choosing by applying Salp Swarm Algorithm (SSA) after ...

The popularity of Wireless Sensor Network (WSN) has increased tremendously in recent times. WSN has the potential to connect the physical world with the virtual world by forming a network of sensor nodes. Sensor nodes transmit the data to the other nodes present in their range. Localization in radio networks has been an intense area of research for quite some years, for military, civil and sens...

The research interest in the cooperation of tiny devices to monitor several kinds of magnitudes or the different events that may arise in a particular wide area has increased in the last years. This cooperation yields new – and robust – communication algorithms so that the information can flow from the sensors to a data sink, where it will be further processed. All these tasks can be simplified...

Large-scale wireless sensor networks consist of thousands of tiny and low cost nodes with very limited energy, computing power and communication capabilities. They have a myriad of possible applications. They can be used in hazardous and hostile environments to sense for deadly gases and high temperatures, in personal area networks to monitor vital signs, in military and civilian environments f...