Abstract A wireless sensor network (WSN) is a form of network that consists of randomly distributed devices/nodes ina known space. In this kind of environment there are two major concerns that governs the efficiency, availability andfunctionality of the network, namely power consumption and fault tolerance. This paper introduces a new algorithm thatis Power Efficient Cluster Algorithm (PECA). The main focus... A wireless sensor network (WSN) is a form of network that consists of randomly distributed devices/nodes ina known space. In this kind of environment there are two major concerns that governs the efficiency, availability andfunctionality of the network, namely power consumption and fault tolerance. This paper introduces a new algorithm thatis Power Efficient Cluster Algorithm (PECA). The main focus of the proposed algorithm is to reduce the power consumptionrequired to setup the network since it is the stage where power is used the most. This is achieved by reducing the totalnumber of radio transmission required for the network setup. As a fault tolerance approach, the algorithm stores someinformation about each node for easier recovery of the network should any node fails in the network. The proposedalgorithm is compared with Self Organizing Sensor (SOS) algorithm; the result shows that PECA consume significantlyless power than SOS. Read More Read Less

Abstract The crucial issue in Wireless Sensor Networks is saving energy so that the lifetime of in-field deployments canbe extended. It was documented that the communication is generally the most energy consuming task and needs to bereduced in order to build resource-efficient long-term applications. It is evident that the communication demand forretrieving query results from deep within the sensor network is... The crucial issue in Wireless Sensor Networks is saving energy so that the lifetime of in-field deployments canbe extended. It was documented that the communication is generally the most energy consuming task and needs to bereduced in order to build resource-efficient long-term applications. It is evident that the communication demand forretrieving query results from deep within the sensor network is typically high. As a result, frequent non-continuous dataacquisition consumes a lot of energy and shortens the lifetime of the sensor network significantly. We address the issue ofoptimizations for processing high amounts of unique queries by using a dynamic adaptive caching scheme: the DACS. InDACS query results can be retrieved from caches that are placed nearer to the query source instead of sending queriesdeep into the network. The communication demand can be significantly reduced and the entire network lifetime isextended. To verify cache coherence in sensor networks with non-reliable communication channels, an approximativeupdate policy is used. To localize the adequate cache adaptively, model-driven queries including a degree of demandedresult quality can be defined. The entire logic is thereby processed by DACS and hidden to the user. We hav Read More Read Less

Abstract To provide viable solutions in computational problems, the Grid networks take advantage of the resourcesavailable by many computers connected within the networks. To achieve a scalable and reliable Grid network system, theworkload needs to be efficiently distributed among the computing resources accessible on the network. Therefore, adistributed and scalable load-balancing scheme for Grid Networks is proposed in this paper. Besides... To provide viable solutions in computational problems, the Grid networks take advantage of the resourcesavailable by many computers connected within the networks. To achieve a scalable and reliable Grid network system, theworkload needs to be efficiently distributed among the computing resources accessible on the network. Therefore, adistributed and scalable load-balancing scheme for Grid Networks is proposed in this paper. Besides we develop a latencyreduction workload distribution protocol for Grid networks. In this work we document that introducing a latency reductionfactor in the random sampling can reduce the effects of communication latency in the Grid network environment. Simulationresults show that the resulted network system provides an effective, scalable, and reliable load-balancing scheme for thedistributed resources available on Grid networks. Read More Read Less

Abstract The issues in Wireless Sensor Networks (WSNs), are challenging as well as their applications demand for goodservices, distribution, modularity and intelligence. WSNs are characterized by varying software architectures, which hasled to the development of a plethora of WSN middlewares, management and reconfiguration protocols. To ensure thepotential of evolving WSN technologies and software architectures, it is required that the users can... The issues in Wireless Sensor Networks (WSNs), are challenging as well as their applications demand for goodservices, distribution, modularity and intelligence. WSNs are characterized by varying software architectures, which hasled to the development of a plethora of WSN middlewares, management and reconfiguration protocols. To ensure thepotential of evolving WSN technologies and software architectures, it is required that the users can move away fromtraditional approaches towards an adaptable service oriented hybrid architecture, which should ideally run on the platefor wireless sensor devices, to minimize redundant protocol stack overhead. More importantly, the middleware shouldprovide distributed machine to machine communication and implementation level model driven architectures shoulddescribe how the WSN works at each level of the network. In our work we present the compelling arguments for this visionof future WSNs and demonstrates how some of these concepts have been implemented on a significantly large physicalWSN in NIMBUS Center of Embedded Systems Research Cork Ireland. Besides, this work provides an overview ofimplementation of the hybrid native architecture (HNA) on sensor devices and its collaborative functionality with a modelbased Open Framework Middleware (OFM) for WSN. Read More Read Less

Abstract In recent years, the complexity of dynamic and collaborative computing environments in Grid is increasingand hence the access control has become a critical factor. In the earlier works, many approaches have been proposed ingrid environment for scalable and efficient authorizations that are either VO-centric or Resource-centric. While analyzingthe different kinds of proposed authorization systems, we observed that the VO-level and... In recent years, the complexity of dynamic and collaborative computing environments in Grid is increasingand hence the access control has become a critical factor. In the earlier works, many approaches have been proposed ingrid environment for scalable and efficient authorizations that are either VO-centric or Resource-centric. While analyzingthe different kinds of proposed authorization systems, we observed that the VO-level and Resource-level authorizationsystems look at two different aspects of the grid authorization. Indeed, they complement each other, and can be implementedtogether to provide a holistic authorization solution. Hence in this study, we propose a new access control frameworkwhich uses an extended two level RBAC model in Grid computing environments. By separating the administrations ofusers by VO level policies and mapping these policies to resources by resource or service providers, our scheme providesdecentralized, autonomous, and fine-grained security management. The art of this approach is support of high flexibilityin policy configuration, dynamically modifying authorization policies and reducing the cost of policy management. Read More Read Less