Applied Mechanics and Materials Vols. 40-41

Abstract: Cooperation of enterprises, colleges and institutes in essence is the management of knowledge supply chain. The cooperation can bring about excess earnings, with fair and reasonable profit allocation playing the role of power mechanism which facilitates cooperation of partners. We adopt a method that combines qualitative and quantitative research and establishes the profit allocation mechanism bonding cooperation of enterprises, colleges and institutes. Empirical analysis of cooperation profits allocation methods are carried out with the application of Shapley value.

Abstract: SCUBA diving is popular used ,while its safety is not ensured as underwater communication can not be established, in order to improve the safety of scuba diving ,here through the study on features of different ways of underwater communication, we think that the laser underwater communication is best way .

Abstract: Science and technology innovation is the power of enterprise development, since the 1980s, A series of science and technology policies have been formulated according to the needs in different periods. Because the policy varies in different circumstances, science and technology innovation environment, such as social innovation atmosphere, information and service supply still depend on the creation of local authority. Therefore, this paper defines the framework of the technology innovation, takes up the countermeasure of improving local innovation in science and technology, including: create favorable policy environment, and build scientific and technological innovation atmosphere, guide the limited resources, technology intermediary market, so as to coordinate and support local technology innovation and achieve the goal of the coordinate development of the science& technology, economy and society. Technological innovation is the originality of scientific research and technological innovation, refers to the floorboard of creation and application of new technology, new knowledge, new technology, using the new mode of production and management model, and develop new products, improve product quality, provide the new service process. Macro frame is refers to the macro-control of laws, regulations and policies, China national science and technology innovation policy innovation of science and technology is the place where, macro frame to support science and technology innovation in the science and technology to implement national policy.

Abstract: Electronic contract platform based on electronic signature technology effectively compensates for the defects of traditional paper contract, reduces the human, material and financial expenditure and improves working efficiency, which has become a new profit growth point of the enterprises. It meets the needs of fast-paced business mode and promotes supply chain operations. Comprehensive research on operation model foe Electronic contract services platform is discussed in this paper.

Abstract: In view of the current application deficiency of neuro-fuzzy network, a new optimal method of neurofuzzy network based on variable precision rough set is presented and its application in complex systems modeling is discussed. This method takes the β classification accuracy of variable precision rough set theory as information function to select the condition attribute, and then modeling data are discredited through selecting a proper precision to forms a decision table. Finally, the significant attributes and the key attribute values are extract from the decision table by using reduction algorithm based on variable precision, and are map pad into the fuzzy rules.It simplifies the fuzzy rules and therefore optimize the structure of neuro- fuzzy network effectively, reducing the training time of neural network greatly and improving the precision of training. This method has been applied to the modeling of non-linear time-delay system with a large number of sam-pling data, the validity and feasibility of this method is demonstrated by an example of modeling.

Abstract: The network hub nodes consumed excessive energy and failed prematurely, thus it reduced the network lifetime. In order to solve the problem, distributed lifetime optimized routing algorithm (DLOR) for wireless sensor networks was proposed. Energy for transmitting data and neighbor node residual energy were considered comprehensively. Then new weight function was introduced and distributed asynchronous Bellman-Ford algorithm was also used to construct the shortest routing tree. Finally, data were gathered along the shortest routing tree to sink node. Simulation results show that DLOR algorithm can extend network lifetime and enable cost-effective energy consumption. Under certain conditions, DLOR algorithm outperforms PEDAP, GreedyDijkstra, LET, Ratio-w and Sum-w algorithms.

Abstract: This paper proposes a method of the coupling modal, which is able to miniaturize the tunable cavity filter while keeping its bandwidth balancing. The filter consists of a tunable cavity dual-bandpass filter and a triangular twin-loop as its inter-cavities coupling structure. We analyzed and calculated the bandwidth of the filter changing with the size and position of the triangular twin-loop. To prove the advancement of the design, a tunable coaxial cavity dual-bandpass filter operating at 230MHz and 409MHz was fabricated and measured. The size is less then a half that of the conventional tunable filter with same specifications. The insertion loss is lower than 1.2dB at operating frequencies. And the bandwidth in lowband and highband are both more than 2.5MHz with the insertion loss less then 3dB. Experiment results and theoretic analysis agree well. This novel model can contribute to the miniaturization of RF and microwave systems with high quality.

Abstract: Mobile Ad hoc Network (MANET) has attracted lots of research efforts these years, mainly due to its appealing applications in no infrastructure situations such as battle fields and disaster recovery operations [1]. In this paper, we explore wireless Ad Hoc network focusing on its Routing Protocol AODV, we in depth analyze its operation principles and the problems exist in AODV routing protocol. AODV routing protocol is vulnerable, it is always exposed to many attacks, such as DoS, black hole, etc. [2] Through exhaustive researching the behaviors of black hole attack in NS2 simulation platform, and we finally propose a new routing security strategy to defense the black hole attack in AODV. Simulation results show that the strategy we proposed can not only effectively defense the black hole nodes, but also has better routing performance for moderate or small scale Ad Hoc Networks.

Abstract: The performance of backoff algorithm plays an important role in designing efficient Medium Access Protocols for Ad hoc networks. In this paper, we propose three backoff algorithms for Ad hoc networks. The first algorithm aims at higher fairness, and the second aims at stronger adaptivity. Then, we combine the first two algorithms to propose an optimized backoff algorithm. We use NS2 to simulate Ad hoc network environment to evaluate the performance of our improved backoff algorithms. The results show that our algorithms exhibit a significant improvement in throughput and fairness with the existing BEB and AASC algorithm.

Abstract: Histogram analysis for wavelet coefficients is powerful steganalysis for detecting the presence of secret information embedded in the wavelet coefficients. In order to improve the security, a wavelet-based steganography against histogram analysis is presented. First, a cover image is divided into blocks, and every block is decomposed into wavelet. Then, if the secret bit is not same as the information denoted by nonzero wavelet coefficient, the absolute value of wavelet coefficient is subtracted by 1, if the value of wavelet coefficient was 0 after embedding the secret bit, the secret bit should be embedded into next wavelet coefficient. If the sum of wavelet coefficients is large, the wavelet coefficients of next level should be embedded by secret information. Finally, the stego-image can be obtained by using the inverse wavelet transform. From the experimental results, the proposed method could effectively keep the identity of histogram for wavelet coefficients and maintain a good visual quality of stego-image.