In Wireless Sensor Networks (WSNs) energy is a scarce resource which must be utilized efficiently in order to enhance the network lifetime. Two-Tiered Wireless Sensor Network (TT-WSN) architecture is proposed to improve the lifetime longevity of the network. In TT-WSN the lower tier consists of sensor nodes (SN), which are mainly responsible for sensing the environment and forwarding the data to its one hop neighbor relay node (RN). While the upper tier is constituent of more power affluent relay nodes (RNs), which deliver the data to the base station through potentially multiple connected relay nodes in a multi-hop fashion. As relay nodes are more expensive, it is therefore desirable to deploy a minimum number of such nodes so that every sensor node has at least one relay node as its one-hop neighbor and all the relay nodes form a connected network. Unfortunately the problem of finding such a minimum set of relay nodes is NP-Hard. Thus an approximation based algorithm is required to solve the problem in polynomial time. Existing solutions are either very complex or less efficient. In this paper we present a fast approximation algorithm to solve the problem in polynomial time. The performance of the algorithm is compared with the existing algorithms through simulations. The extensive simulation results show that our algorithm outperforms the existing algorithms in terms of number of relay nodes deployed.
Abstract:Incompetency of masons is a problem because they execute many construction activities. This imparts the need to identify factors that affect the competency of masons on construction sites. Factors related to motivation, skills and personality traits are identified. A questionnaire instrument consisting of 15 factors related to the three categories was forwarded to masons on construction projects. Responses collected on a five-point Likert scale were analysed for relative importance index (RII), which was used as the basis for ranking the factors. 'Resistance to change', 'lack of appreciation', and 'lack of formal training' were identified as the first, second, and third most important factors affecting the competency of masons on construction projects. The impact of the category of motivation was found to be the highest on the competency of masons, followed by skills, and personality traits. These findings may be utilised as an assessment tool for determining the competency of masons and identifying areas that need improvements.Keywords: masons; competency; performance; skills; motivation; personality traits.Reference to this paper should be made as follows: Choudhry, R.M. and Zafar, B. (2017) has demonstrated a strong interest in improving the efficiency, productivity and safety of construction projects. He has published 81 papers in refereed journals and conferences.Bilal Zafar is a graduate student in the
Abstract-As chip multiprocessors transition from multi-core to many-core, on-chip network power is increasingly becoming a key barrier to scalability. Studies have shown that on-chip networks can consume up to 36% of the total chip power, while analysis of network traffic reveals that for extended periods of execution time, network load is well below the network capacity in many applications. In recent studies, researchers have proposed to exploit this temporal variability in network traffic to dynamically turn off links, buffers and segments of the onchip routers. In this work, we make the case for a polymorphic topology, called Cubic Ring (cRing), that allows dynamically turning off over 30% of resources in a 2D network (and more in higher dimensional networks), with less than 5% increase in average distance. As a result, cRing networks provide an elegant way to trade off network bandwidth for lower (static) power. A complete formalism for the proposed cRing topologies and the associated routing algorithm is presented, along with evaluation under synthetic workloads.
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