Applied Mechanics and Materials Vols. 427-429

Abstract: Since the 1970s, with the in-depth study of graph partitioning, we have found that, graph partitioning, both in the fields of academic researches and engineering applications, has its own important applications, such as the layout of the fiber-optic network in telecommunication network. Therefore, the graph partitioning problem has been widespread concerning and largely studied by the scholars at home and abroad. Tabu search, as one of the modern optimization algorithm, has been playing an invaluable effect in many fields. And by now, both graph partitioning and tabu search have been developed to a certain extent, but few people consider the integration of the two problems, coordinate optimization, so as to achieve better results. Therefore, this paper proposes a graph partitioning method based on coordination and optimization of constructive graph partitioning algorithm and tabu search algorithm and obtains a graph partitioning algorithms of good efficiency and quality. In the experimental part of the paper, optical distribution network partitioning problem is transformed into a graph partitioning model. Experimental results show that the efficiency and quality of the partitioning method are acceptable in optical distribution network division.

Abstract: Optical Distribution Network is a kind of optical transmission path connecting Optical Line Terminal and Optical Network Unit. This article mainly studies how to optimize broadband loan problems of the backbone network. In order to get the best allocation scheme of the Optical Distribution Network problems, we propose a solution which is converting the Optical Distribution Network partitioning problem into a graph partitioning model, and solve the problem by adopting Graph partitioning algorithms. Graph partitioning is about the undirected graph , is the collection of all vertexes. is the collection of all sides. Any vertex in the vertex set has weight value of a positive integer. Any side in a side set has weight value of a positive integer. The vertex set is divided into non-intersecting subsets , and .As to every subset , it has ,,.What we need to solve is to get the minimum sum of weight values between m non-intersecting subsets. The experimental results show that Graph partitioning algorithm is efficient.

Abstract: To address the security problems caused by the fake readers, and the weakness of low authentication protocol efficiency, a new RFID security authentication protocol based on Hash function is proposed. The security ability of the protocol is compared with other protocols' and is proved by doing the formal analysis. The theoretical analysis and formal proof is presented to prove the security ability of the protocol. Consequently, the result showed that the new protocol could protect the data privacy, achieve the data synchronization, prevent the tag from location tracking, avoid information reproduction, prevent clone and counterfeit and possess forward security ability which was useful for low-cost tags.

Abstract: Energy-Constrained Ferry Route Design (ECFRD) Problem is an NP-hard problem to minimize the total route length of a message ferry to access all the sensor nodes in a sparse wireless sensor network, while the route length of a tour under a given value due to the energy constraint. In this paper, we propose an angle partitioning based algorithm (APBA) to solve the ECFRD problem. In APBA, the nodes are partitioned into groups according to the tangent angles of their coordinates, and the route length of each group will not exceed the energy constraint. The experimental results show that APBA can greatly reduce the total route length of the ferry. In the best case, 35% of the total route length can be saved, comparing previous nearest neighbor based split and route algorithms.

Abstract: In the traditional scheduling scheme of the message ferry in wireless sensor networks, the route of a ferry is usually designed as a simple cycle. Closed Walk Ferry Route Design (CWFRD) aims to design the ferry route as a closed walk which contains more than one simple cycle to minimize the average weighted delay of the sensed data to the sink. In this paper, an Modified Ant Colony Optimization Algorithm (MACOA) is proposed to solve the CWFRD problem. The experimental results show that MACOA can greatly reduce the average weighted delay, comparing the previous proposed algorithms.

Abstract: Aiming at the deficiency in the hierarchical routing algorithm, an improved routing algorithm of ring based multi-hop clustering (IRBMC) is developed. The main idea of IRBMC is to divide wireless sensor networks field into heterogeneous spacing rings to control the cluster number and build unequal size of clusters in different rings. To ensure the higher energy level nodes having more chance to become cluster head, the improved average residual energy estimation is used to determine the probability of nodes in each ring to be the cluster heads. Simulation results illustrate that IRBMC has a better result in prolonging the lifetime of network with the multi-level energy than the stable election protocol (SEP) for clustered heterogeneous wireless sensor networks, the low-energy adaptive clustering hierarchy (LEACH), and the ring based multi-hop clustering (RBMC) algorithm. The lifetime of IRBMC is 1.14 times of SEP, 1.57 times of LEACH, and 1.6 times of RBMC.

Abstract: Efficient parallel iterative algorithm is investigated for solving block-tridiagonal linear systems on distributed-memory multi-computers. Based on Galerkin theory, the communication only need twice between the adjacent processors per iteration step. Furthermore, the condition for convergence is given when the coefficient matrix A is a symmetric positive definite matrix. Numerical experiments implemented on the cluster verify that our algorithm parallel acceleration rates and efficiency are higher than the multisplitting one, and has the advantages over the multisplitting method of high efficiency and low memory space.

Abstract: The idea of orthogonal space is introduced into multiple watermarking, and a new type of multiple watermarking method based on the principle of orthogonality is summarized. Two different subclasses are introduced, while in one subclass, the watermarks are made to be orthogonal to each other before embedded, and in the other subclass, the watermarks are embedded into the cover vectors which are orthogonal to each other and extracted from the original cover. The performances of the two subclasses are compared and analyzed, and the analytic results show that the multiple watermarking method based on the principle of orthogonality has very good performances, such as the capacity of singular watermark and the number of watermarks that can be embedded, and what's more, it can avoid the interference of one watermark signal with another.

Abstract: 4-ary vector expression was defined by 3-ary vector to describe subject and data item in dataspace. Association method between subject and data item was represented. Correlation of data item was defined by 4-ary vector. Correlation and association way between data items were represented by 4-ary vector. The validity of these methods was verified in technical document library.

Abstract: Similar to the orthogonal frequency division multiple access (OFDMA) system, the carrier frequency offset (CFO) is a challenging problem in the single carrier frequency division multiple access (SC-FDMA) system, which can destroy the orthogonality among the subcarriers. As a consequence, multi-access interference (MAI) along with serious performance degradation will be induced. In this paper, a zero forcing (ZF)-based MAI cancellation scheme is proposed. Compared with other cancellation schemes, the proposed one mitigates the interferences in the time domain instead of the frequency domain. Simulation results show that the proposed method can significantly reduce the degradation and enhance the Bit Error Ratio (BER) performance.