Abstract-Wireless sensor networks (WSNs) have been extensively researched recently. This paper makes two contributions to this field. First, we promote a new concept of long-thin (LT) topology for WSNs, where a network may have a number of linear paths of nodes as backbones connecting to each other. These backbones are to extend the network to the intended coverage areas. At the first glance, a LT WSN only seems to be a special case of numerous WSN topologies. However, we observe, from real deployment experiments, that such a topology is quite general in many applications and deployments. The second contribution is that we show that the address assignment and thus the tree routing scheme defined in the original ZigBee specification may work poorly, if not fail, in a LT topology. We thus propose simple, yet efficient, address assignment and routing schemes for a LT WSN. Simulation results and prototyping experiences are also reported.Index Terms-address assignment, long-thin network, routing protocol, wireless sensor network, ZigBee.

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The concept of a spectrum-modifying layer is proposed for the design of a silicon-based guided-mode resonance filter. To realize such a novel device, a grating and waveguide structures are fabricated simultaneously in a suspended silicon nitride membrane. The cladding layer of the silicon substrate is replaced by the silicon dioxide membrane to reduce the absorption loss of the bulky substrate. Moreover, the silicon dioxide membrane plays a role in modifying the spectral response. According to the experimental results of the proposed structures, symmetrical line shapes and improved sidebands of nonresonance are demonstrated.

An important issue of wireless sensor networks is object tracking, where the key steps include event detection, target classification, location estimation and location management. The main theme of this paper is location management. Because imprecision is an inherent property in object-tracking sensor networks, this paper focuses on the scenarios where users can tolerate a certain degree of imprecision in their query results. We intend to develop a location management scheme that can achieve two goals. First, multiple precision levels are provided. Second, the query cost is proportional to the precision level. To achieve these two goals, we propose a tree-based imprecision-tolerant location management scheme that includes three major components: (1) update and query mechanisms that can support imprecision-tolerant queries, (2) the approach to taking the statistics of imprecisiontolerant queries and (3) a tree construction algorithm that can reduce the query cost and minimize the increment of update cost. Performance evaluations are conducted through simulations to verify the proposed scheme.

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ZrMn 6 Sn 6−x Ga x (0.25 x 3.50) compounds of HfFe 6 Ge 6 -type structure (P6/mmm) have been studied using powder neutron diffraction experiments in the 2-600 K temperature range. Below their magnetic ordering temperatures, these phases adopt commensurate easy-plane magnetic arrangements: + − − + antiferromagnetic AF2 (x 0.60) or ferromagnetic (x 0.70). At low temperature, the Ga-poor compounds (x 0.80) exhibit a transition to concentration-dependent incommensurate configurations. Upon increasing the Ga content, this incommensurate state evolves from helimagnetic to fan-like through arrangements we termed antifan-like. The Mn moment value is close to m Mn ≈ 2.0 µ B for the Ga-rich and Ga-poor compounds and reaches a maximum amplitude of m Mn ≈ 3.0 µ B in the (anti)fan-like structures of intermediate concentrations. A tentative (x, T ) magnetic phase diagram is presented. The occurrence of Lifshitz point(s) is forecast for 0.60 < x < 0.70.

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