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Wireless sensor Network(WSN) has newly drawn lots of attention due to its application in the medical, environment, military and industry. Due to maximum coverage, sensor node has mobility for improving network coverage in the wireless sensor network. The spatially distributed sensor nodes collect from the environment through the movement. Mobility of sensor is based on connectivity and optimizes the coverage on whole target area. Finding near optimal solutions for sensor deployment is issued in Wireless sensor networks (WSN). Optimum deployment of the sensor nodes is favorable to the largest potential utilization of the sensor network. Optimization deployment of the mobile sensor provides fault tolerance in WNSN that can help network prolonging the lifetime, reduce the size of complexity and increase the quality of service (QoS) especially for WSNs applications. Wireless sensor deployment problem, by using the power of Particle Swarm Optimization (PSO) in order to minimize movement of the mobile node and increase the lifetime of the network while optimizing the network coverage.

Wireless Sensor Network is consisting of number of limited sensor devices which are communicated over the wireless media. There are a lot of its application in military, health and industry. As sensor devices are resource restricted, the networks exposed to different types of attacks and conventional techniques against these attacks are not desirable due to the resource constrained nature of these kinds of networks. Therefore, security in WSNs is a challenging task due to inheritance limitations of sensors and it becomes a good topic for researchers. In this paper we focus at secure hierarchal routing protocols in wireless sensor networks and represent selected approaches which focusing at this matter. Finally we develop a matrix which generalizes previous works and analyze the proposed matrix and then suggests the protocols to be applied in proper application.

This paper outlines a theoretical framework intended to provide a more ecological and holistic accounting of how, why and where people learn in relation to constructs of human difference – race, class, disability designation, etc. – as learners circulate across places and associated operating value systems over multiple timescales. The framework for <i>cultural learning pathways</i> is an application and elaboration of Ole Dreier's theory of persons in diversities of structures of social practice with a focus on the learning of disciplinary practices and the development of discipline-related identities. We summarize relevant learning phenomena along extended cultural pathways from three team ethnographies of science learning. We outline how power-related issues associated with privilege and marginalization are attended to in relation to the social, cultural, and material circumstances of learning within and across environments and discuss future research opportunities.

Calls for the improvement of science education in the USA continue unabated, with particular concern for the quality of learning opportunities for students from historically nondominant communities. Despite many and varied efforts, the field continues to struggle to create robust, meaningful forms of science education. We argue that 'settled expectations' in schooling function to (a) restrict the content and form of science valued and communicated through science education and (b) locate students, particularly those from nondominant communities, in untenable epistemological positions that work against engagement in meaningful science learning. In this article we examine two episodes with the intention of reimagining the relationship between science learning, classroom teaching, and emerging understandings of grounding concepts in scientific fields – a process we call <i>desettling</i>. Building from the examples, we draw out some key ways in which desettling and reimagining core relations between nature and culture can shift possibilities in learning and development, particularly for nondominant students.