Applied Mechanics and Materials Vol. 696

Abstract: Mineral resources development overseas needs foreign geological literature, this paper carried out a research on the construction of a foreign geological literature integration service system, and discuss the system framework, functional analysis, system implementation in detail. The target of foreign geological literature integration service system is to establish a database and carry out information services through the collection and collation of foreign geological literature information and foreign hot topic in the field of geology and mineral information. The system utilizes database technology, geographic information systems technology, data mining techniques and other network information technology, to achieve the integration of resources, professional services and management of geological library.

Abstract: This paper focuses its research work on the capacity and outage performances of a distributed multiple-input multiple-output (DMIMO) system in a multi-cell environment. For this purpose, the multi-cell DMIMO structure is modeled first, and based on this model, the so-called blanket communication and selective communication schemes are compared, and the formula of the output signal to interference plus noise ratio (SINR) of the above two schemes are given to illustrate the way of an inter-cell interference affecting the system performance. Then the expressions of the average capacity and outage probability are derived by using the probability density function (PDF) of the output SINR in the preferred selective communication scheme with some necessary approximations. Finally, the computer simulations are provided to explore the possible rule of upper layer network scheduling in overcoming the inter-cell interferences and in optimizing the capacity and outage performances in the DMIMO systems.

Abstract: To solve multi-radio multichannel (MRMC) wireless Mesh network channel assignment problems, we propose and study the PGCA (channel assignment based on potential game) method. PGCA takes each link of the network as a player by designing rational potential function. The action strategies between links select resources containing channel and space information. PGCA converts maximum network throughput into minimum network interference by joint game. Simulation results show PGCA algorithm has better performance in terms of convergence speed and the network throughput. The end-to-end delay has connected with the number of links.

Abstract: This paper proposes a MIMO-OFDM signal detection algorithm with joint ML and MMSE-OSIC based on researches of ML algorithm and MMSE-OSIC algorithm. This kind of algorithm is an improved algorithm of MMSE-OSIC. Comparing to the traditional MMSE-OSIC algorithm, this algorithm uses ML detection on the relatively weaker signal layer. According to the experiment, it was found close to the optimal detection performance, much less complicated than the ML algorithm, which is a near-optimal and low-complexity MIMO-OFDM detection algorithm.

Abstract: For multi-relay orthogonal frequency division multiplexing (OFDM) systems, efficient subcarrier pairing and resource allocation are significant to boost the system performance. We study the joint optimization problem of subcarrier assignment, subcarrier pairing and power allocation, to maximize the system transmission rate under a total power constraint. Many previous works formulate such a problem as a mixed integer programming problem, then transform it into a convex optimization problem by continuous relaxation and pair all the subcarriers using Hungarian method, which requires high computation complexity. In this paper, we assign each subcarrier in both hops to the relay that has the highest channel gain on that subcarrier. Since the numbers of subcarriers assigned to each relay in both hops, denoted as n₁(k) and n₂(k), are probably different, we first sort the subcarriers in descending order and pair the front min {n₁(k),n₂(k)} subcarriers assigned to each relay in sorted way, then we assign and pair the remaining subcarriers using Hungarian method. Due to the decrease of matrix dimensions when using Hungarian method, the computation complexity of the suboptimal algorithm is reduced. Simulation results show that the suboptimal algorithm provides the similar performance to that of the optimal algorithm with much lower computation complexity.

Abstract: Wireless Mesh Networks (WMN) is distributed broadband wireless network architecture with characteristic of high throughput and high data rate. The quantity of research being conducted in this area has dramatically increased recently. Medium Access Control (MAC) is the key technology to exploit the multi-hop advantage of WMN. This paper introduces two major research topic of MAC design in WMN, the topology control and link scheduling. A survey of recent research on these topics is given in detail.

Abstract: This paper puts forward and realizes an algorithm which optimize the video encoding based on human selective attention. The algorithm considering the influence of human visual attention area have on mode selection, correct the traditional pattern of full search algorithm, and find a more effective rapid method to determine the best encoding mode, so as to achieve the whole optimization of video coding algorithm. The experimental results show that the proposed algorithm can improve the subjective experience of the video sequence, effectively reduces the time of video encoding without significantly affect the PSNR.

Abstract: We introduce the clustering algorithm to the behavior measure, which can effectively detect the malicious behavior, and the simulation verifies the efficiency of the scheme. This method can be well applied to the user behavior measure under open network.

Abstract: Based on the idea of privilege set, this paper proposes a threshold group signature scheme with multiple privilege sets. Only when the joint involvement of ordinary users under satisfied conditions and privileged users with multiple privilege sets can the valid proxy group signature be generated. Some members can’s forge signatures, which can help resist attacks. The threshold signature scheme has good features of privilege sets and threshold characteristics, unforgeability of signature and anonymity of verification and traceability of identity.

Abstract: In view of the poor portability, low efficiency of this interface existing monitoring scheme, the paper studies the protocol specification, signaling processes related S6a interface in the LTE (Long Term Evolution, Long Term Evolution) network, etc., then brings forth a synthetic scheme related with the Diameter protocol association. After passing through the current network data test, a relatively accurate method to reproduce S6a interface signaling processes, the scheme verifies the correctness and feasibility of the program, and provides a reliable guarantee basis for monitoring the interface.