Thesis (M.S. in computer science )--Washington State University, August 2009. / Title from PDF title page (viewed on Apr. 2, 2010). "School of Electrical Engineering and Computer Science." Includes bibliographical references (p. 65-73).

Thesis (M.Sc.)--York University, 2008. Graduate Programme in Computer Science. / Typescript. Includes bibliographical references (leaves 147-152). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR51580

AN ABSTRACT OF THE THESIS OF ISMAIL GUNEYDAS, for the Master of Science degree in Computer Science, presented on 5th November 2008, at Southern Illinois University Carbondale. TITLE: ACTOR POSITIONING IN WIRELESS SENSOR AND ACTOR NETWORKS USING MATCHING THEORY. MAJOR PROFESSOR: Dr. KEMAL AKKAYA In most of the Wireless sensor and actor network (WSAN) applications, the locations for the actors are determined autonomously by the collaboration of actors and/or sensors in order to eliminate human intervention as much as possible. Particularly, sensors can collaborate in a distributed manner and elect cluster-heads (CHs) among them which will be taking into account the distribution of the sensors within the region. In such cases, the actors can then move to such sensor locations (i.e., replace them as cluster-heads) as they have the ability to move by talking to nearby sensors/actors. Such movement, however, should be done wisely in order to minimize the total distance that will be traveled by the actors so that their lifetimes can be extended. Nevertheless, this may not be possible since not all the actor and CH locations will be known to each actor. In addition, the actors may not be reachable to each other and thus conflicts in assignments can easily occur. In this thesis, we propose an actor-CH location matching algorithm which will detect the CH locations and assign the actors to such locations in a distributed manner with the minimized travel distance. We adapt the Gale-Shapley (G-S) stable matching algorithm from Matching Theory in order to prevent conflicts and minimize the travel distance. In this matching algorithm, actors are regarded as men and CHs are regarded as women. First, we detect the CH locations through running a quorum-based search within the sensor network. Later, G-S is run on actor and CH locations. Once the locations are determined, each actor moves to that location. We evaluated the performance of our approach through simulation and have shown that our approach can produce results very close to the brute force approach.

Wireless sensor network has been an area of interest among researchers. Designing a wireless sensor network involves multiple issues such as size and processing capacity of the sensors, number of the cluster heads, number of the base stations, routing protocols, battery of the nodes, layout of the system, etc. Battery is a critical factor, since sensor networks do not involve maintenance as they are situated in remote places. Hence the available battery must be utilized effectively to increase the efficiency. In our study we address issues associated with battery such that to increase the lifetime of the system. Existing standards for the sensors are implemented with each node having equal battery level `B' referred to as `Uniform system' in our study. Thus total amount of battery consumed by N nodes is `N * B'. In our approach we study the distribution of this `N * B' battery in non-uniform manner, referred as `Non-uniform system', such that each node would be allocated with different battery level depending upon its position and amount of information it receives and transmits. Initially we commence with the observation of the behavior of this approach on a chain of nodes. These nodes generate information at constant rate and transmit per cycle. We observed that there is a huge amount of increase in the lifetime as compared to lifetime of the uniform system. We step further in our experimentation by restricting the amount of battery each node can have and then quantizing it. Results indicate that only 3 levels of batteries instead of N, give us significant increase in the lifetime. These results validate our approach for practical implementation. We progressed by observing success of our approach on random topology where nodes are laid randomly in the area of experimentation. Approximately same increase in the lifetime as achieved initially without restricting battery levels can be achieved. Simulation results show that non-uniform system performs much better than uniform system. This approach of non uniform battery levels can be implemented in sensor networks such that system lives longer giving more throughput and thus increasing efficiency.

Wireless sensor networks (WSNs) are systems of resource-constrained sensor nodes (SNs), distributed throughout a sensor field. Energy limitations persist due to the wireless nature of SNs and an interest in minimizing the cost and physical footprint of SNs. Due to the resource-constrained nature of SNs, much WSN research has focused on energy-efficient communication algorithms. Communication algorithms are necessary for energy-efficient data transmission between SNs and the transmission of data collected by SNs to a base station. A popular algorithm known as Low-Energy Adaptive Clustering Hierarchy (LEACH) achieves more energy-efficient communication by organizing SNs into clusters for localized communication. When SNs are mobile, the energy efficiency of LEACH is degraded because of geographic dispersion of SN clusters. This thesis proposes LEACH-Centered Cluster-head (LEACH-CCH), a clustering algorithm aimed at improving WSN lifetime in cases of stationary and mobile sensor nodes. Mobile sensor network applications are explored including vehicle-to-infrastructure communication networks.

No description available.

Doctor of Philosophy (PhD) / Sensor networks have great potential to be employed in mission critical situations like battlefields but also in more everyday security and commercial applications such as building and traffic surveillance, habitat monitoring and smart homes etc. However, wireless sensor networks pose unique security challenges. While the deployment of sensor nodes in an unattended environment makes the networks vulnerable to a variety of potential attacks, the inherent power and memory limitations of sensor nodes makes conventional security solutions unfeasible. Though there has been some development in the field of sensor network security, the solutions presented thus far address only some of security problems faced. This research presents a security framework WSNSF (Wireless Sensor Networks Security Framework) to provide a comprehensive security solution against the known attacks in sensor networks. The proposed framework consists of four interacting components: a secure triple-key (STKS) scheme, secure routing algorithms (SRAs), a secure localization technique (SLT) and a malicious node detection mechanism. Singly, each of these components can achieve certain level of security. However, when deployed as a framework, a high degree of security is achievable. WSNSF takes into consideration the communication and computation limitations of sensor networks. While there is always a trade off between security and performance, experimental results prove that the proposed framework can achieve high degree of security with negligible overheads.

Doctor of Philosophy (PhD) / Sensor networks have great potential to be employed in mission critical situations like battlefields but also in more everyday security and commercial applications such as building and traffic surveillance, habitat monitoring and smart homes etc. However, wireless sensor networks pose unique security challenges. While the deployment of sensor nodes in an unattended environment makes the networks vulnerable to a variety of potential attacks, the inherent power and memory limitations of sensor nodes makes conventional security solutions unfeasible. Though there has been some development in the field of sensor network security, the solutions presented thus far address only some of security problems faced. This research presents a security framework WSNSF (Wireless Sensor Networks Security Framework) to provide a comprehensive security solution against the known attacks in sensor networks. The proposed framework consists of four interacting components: a secure triple-key (STKS) scheme, secure routing algorithms (SRAs), a secure localization technique (SLT) and a malicious node detection mechanism. Singly, each of these components can achieve certain level of security. However, when deployed as a framework, a high degree of security is achievable. WSNSF takes into consideration the communication and computation limitations of sensor networks. While there is always a trade off between security and performance, experimental results prove that the proposed framework can achieve high degree of security with negligible overheads.

Wireless sensor networks (WSNs) are becoming increasingly pervasive in a number of applications. Due to the nature of WSNs, one of their biggest constraints is limited node energy. As WSNs grow in popularity, the prevalent issue remains to keep wireless sensor nodes alive for as long as possible, or risk disrupting the network. This dissertation develops a model based on the principles of game theory to improve the energy efficiency of wireless sensor nodes and increase the network lifetime by influencing the way routing takes place. The benefit of this model is a routing algorithm that is easily implementable and increases network lifetime by improving energy efficiency in the network. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015

Wireless sensor networks (WSNs) are becoming increasingly pervasive in a number of applications. Due to the nature of WSNs, one of their biggest constraints is limited node energy. As WSNs grow in popularity, the prevalent issue remains to keep wireless sensor nodes alive for as long as possible, or risk disrupting the network. This dissertation develops a model based on the principles of game theory to improve the energy efficiency of wireless sensor nodes and increase the network lifetime by influencing the way routing takes place. The benefit of this model is a routing algorithm that is easily implementable and increases network lifetime by improving energy efficiency in the network. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015