Since the existence of characteristics of heterogeneity, limited energy, complexity and so forth, it turns into a research hot spot on the security mechanism of wireless sensor networks (WSN), especially the problems on the key management. On regard of the deficiency of extant secret sharing schemes, we develop a (t, n) threshold secret sharing scheme which is based on the cylinder model, including the procedures of master-key reconfiguration and sub-key updating. This scheme enables several nodes to be responsible for the security of key together, and by the mean time, we introduce a monitoring mechanism to improve the capability of anti-capturing. With the security theoretical analysis and the comparison with the performance on B-PCGR, GKD simulation experiment, it reveals that our scheme satisfies the security requirement of key management in wireless sensor networks, and can effectively reduce the cost on communication and computation

Optical networks with DWDM (Dense Wavelength Division Multiplex) can provide multiple data channels to supply high speed, high capacity to perform bandwidth-intensive multicast transmission service. Light-tree is a popular technique applied to support point-to-multipoint multicast services. Any failure during a multicast session would cause severe service loss or disruptions, especially when the faults occur near the source node. A novel ring-based local fault recovery mechanism, Multiple Ring-based Local Restoration (MRLR), for point-to-multipoint multicast traffic based on the minimum spanning tree (MST) in WDM mesh networks is proposed in this article. The MRLR mechanism dismembers the multicast tree into several disjoint segment-blocks (sub-trees) and reserves preplanned spare capacity to set up multiple protection rings in each segment-block for providing rapid local recovery. The MRLR scheme outperforms other methodologies in terms of the blocking probability, recovery time, and average hop count of protection path per session for different network topologies.

<p>The Miles Canyon suspension bridge is a 40 m long historic wooden suspension pedestrian bridge across the Yukon River near Whitehorse, Yukon, Canada. The bridge is owned and maintained by the Government of Yukon (GY). The bridge forms an important link in the local trail system and is important for tourism access to some of the historic sites of the Klondike Gold Rush. Non-destructive testing in winter 2015 revealed advanced decay in many members, necessitating full superstructure replacement. A temporary rehabilitation was performed to allow the bridge to temporarily reopen for the summer 2016 tourist season, with a full superstructure replacement in fall 2016. Replacement timber members were carefully selected, detailed, and prefabricated, giving the rehabilitated structure an extended lease on life with proper upkeep and maintenance. Construction of both phases of the work were completed on time and on budget.</p>

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