Evolution of structural ({\alpha}) relaxation-time anomalies in GexSe1-x Chalcogenide glasses

We examine enthalpy relaxation across the chalcogenide glass series GexSe1-x, prepared over close-by compositions using conventional melt-quenching technique. We estimate the timescale {\tau}(Tg) characterizing enthalpic relaxation near the kinetic glass transition temperature, using the non-reversing heat-flow data obtained from MDSC (modulated differential scanning calorimetry) measurements over a wide range of compositions (2.1 {\lessthanequalto} r {\lessthanequalto} 2.8, r = 2x+2). Anomalies in the enthalpy-relaxation characteristic-times {\tau}g(r) are identified as marking rigidity-transitions encountered in successive Ge-doping of polymeric selenium chains.Comment: 10 pages, 3 figures, 30 reference

Product Dimension of Forests and Bounded Treewidth Graphs

The product dimension of a graph G is defined as the minimum natural number l such that G is an induced subgraph of a direct product of l complete graphs. In this paper we study the product dimension of forests, bounded treewidth graphs and k-degenerate graphs. We show that every forest on n vertices has a product dimension at most 1.441logn+3. This improves the best known upper bound of 3logn for the same due to Poljak and Pultr. The technique used in arriving at the above bound is extended and combined with a result on existence of orthogonal Latin squares to show that every graph on n vertices with a treewidth at most t has a product dimension at most (t+2)(logn+1). We also show that every k-degenerate graph on n vertices has a product dimension at most \ceil{8.317klogn}+1. This improves the upper bound of 32klogn for the same by Eaton and Rodl.Comment: 12 pages, 3 figure

Role of ZigBee Technology in Wireless Networking

Zigbee technology is a kind of newly arisen wireless network technology has low frequency, short distance communication, low speed, low power consumption, and low cost, wireless mesh networking Technology. It, Application of Zigbee wireless communication technology, is Industrial control and monitoring sensor networks, building automation, home control and automation, toys and games etc. and With the rapid development of IT industry and the strong functional expansion of SCM, Zigbee wireless communication technology will play an important role in wireless sensor network (WSN). In this paper, Zigbee wireless communication technology and the process of establishing Zigbee network are introduced, the application of Zigbee wireless communication technology is studied in the real world. The ZigBee standard provides network, security, and application support services operating on top of the IEEE 802.15.4 Medium Access Control (MAC) and Physical Layer (PHY) wireless standard. It employs a suite of technologies to enable scalable, self-organizing, self-healing networks that can manage various data traffic patterns