Energy-efficiency analysis of cluster-based routing protocols in wireless sensor network

This paper extends the conditions of the cluster-based routing protocols in terms of general algorithm complexity of data fusion, general compressing ratio of data fusion, and network area with long distance. Corresponding three general evaluation methods to evaluate the energy efficiency of the cluster-based routing protocols such as LEACH, PEGASIS, and BCDCP are provided. Moreover, three facts are found in them: (1) High-level software energy macro model is used to compute the energy dissipation of general data fusion software and make the constant value of energy dissipation of 1-bit data fusion an especial instance. (2) Multi-hop energy efficiency is related to the radio hardware parameters and the dynamic topology of network and the above protocols do not exploit the best use of the energy efficiency of multi-hop scheme. (3) High-energy dissipation non-cluster-head nodes, whose number changes with the density of the sensor nodes in clusters, worsen the death of nodes. The numerical results of experiments reprove these discoveries. Furthermore, they provide helpful guide for improving the above routing protocols to extent their application ranges.

Advances in tailored hot stamping – innovations in material and local patchwork topology

Hot stamping is now commonplace in the automotive industry. The continuing need by automotive manufacturers to reduce weight while increasing crashworthiness has driven the industry to seek new hot stamping solutions. Tailored hot stamping can be thought to produce a part that has patchwork of hard and soft regions. In this context, patchwork means that there is a relational organization (topology) to the network of hard and soft regions. The next generation of tailored hot stamping will therefore combine new steel grades together into a single part, and secondly will be able to locally tailor material properties to meet detailed engineering targets. The key to meeting engineering demands will be how the patchwork material properties are organized on the part. This paper will briefly outline our latest research in tailoring parts.