Advanced Materials Research Vols. 181-182

Abstract: Put forward the method that one kind of calculation antithetical couplet moved the planet circular system efficiency , and expounded uniteing the relation moved between the positive and negative direction drive efficiency of planet circular system . List its efficiency calculation formula that variously joins under the different mobile states of merit rate of method

Abstract: The Stewart machining robot adopts a closed ring structure; the shaft was connected with a number of spatial links. In the coordinate system fixed on the cutter, the coordinates of the hinges joining control links and shaft can be determined. And the posture of the tool can be determined as well. Corresponding to every posture of machining, the position of shaft can made the lengths of the two Control axes equal. So that if one of the controlling ends of NC system controls two axes simultaneously, a 5 coordinate system can realize the function of the 6- coordinate system.

Abstract: from the generation principle and meshing theory of spiral bevel gear, this paper present a method to produce the conjugate tooth surface of point contact, and find its application on the spiral bevel gear with circular tooth profile and cycloid teeth. The equation of tooth surface of this kind is deduced as well.

Abstract: This Sharing over web is an effective approach to improve the utilization factor of Numeric Control (NC) equipments. However, the complex schedule of the multi-queuing system has always been the difficulty of the sharing system. This research applies the burgeoning grid technology regarding the NC resource scheduling as the Constraint Satisfaction Problem (CSP) to develop the correlation-based self-organizing model, involving both logic model and computational model, which constructed based on the analysis of the complex correlations among the NC resource. The self-organizing CSP model is able to provide the mathematic foundation for overcoming the above difficulty in multi-queuing system.

Abstract: In the previous research, a novel embedded multi-phase optimization methodology was proposed to solve the NC-hard difficulty of self-organizing system involving the complex correlated constraints, which has been theoretically verified. This paper takes a serial of comparable experiments to demonstrate the efficiency of the previously proposed novel methodology. First, the description of the universal problem is given, based which the mathematic model for the self-organizing system is elected. Second, a detailed example that includes complex correlated relationship is suggested. Finally, the detailed experiments verify the correct of the proposed methodology, which integrates these two sub optimization problems into a searching loop to ensure the feasibility of solution and improve the searching efficiency in the complex correlated system, with the graphics, figures, and tables.

Abstract: In this study, tensile experiments of Twaron fiber tows under different strain rates (quasi-static:0.001s-1, dynamic: 800s-1~2400s-1) were carried out with MTS 810.23 materials tester and split Hopkinson tension bar (SHTB) respectively. The results showed that the mechanical properties of the Twaron fiber tows were sensitive to strain rate: the stiffness and failure stress of the fiber tows increased distinctly as the strain rate increased, while the failure strain decreased. From scanning electronic microscope (SEM) photographs of the fracture surface, it is indicated that the Twaron fiber tows failed in a more tough mode and the axial split will become more severe as the strain rate increases.

Abstract: The method of merging concept lattice in domain ontology construction can describe the implicit concepts and relationships between concepts more appropriately for semantic representation and query match. In order to enrich semantic query, the paper intends to apply the theory of Formal Concept Analysis (FCA) to establish source concept lattices, through which the domain concepts are extracted from source concept lattices to generate the optimized concept lattice. Then, the ontology tree is generated by lattice mapping ontology algorithm (LMOA) combing some hierarchical relations in the optimized concept lattice. The experiment proves that the domain ontology can be achieved effectively by merging concept lattices and provide the semantic relations more precisely.

Abstract: The vehicle routing problem with delivery and pick-up service was considered in this paper. A tabu search was proposed to determine the optimal set of routes to totally satisfy both the delivery and pick-up demand. Performances are compared with other heuristics appeared in the literature recently by the bench-mark data sets. The computational results show that the proposed approaches produce high quality results within a reasonable computing time.

Abstract: One of the key issues in practical speech processing is to achieve robust voice activity detection (VAD) against the background noise. Most of the statistical model-based approaches have tried to employ the Gaussian assumption in the discrete Fourier transform (DFT) domain, which, however, deviates from the real observation. For a class of VAD algorithms based on Gaussian model and Laplacian model, we incorporate complex Laplacian probability density function to our analysis of statistical properties. Since the statistical characteristics of the speech signal are differently affected by the noise types and levels, to cope with the time-varying environments, our approach is aimed at finding adaptively an appropriate statistical model in an online fashion. The performance of the proposed VAD approaches in stationary noise environment is evaluated with the aid of an objective measure.

Abstract: The communication networks used to smart power grid include wired and wireless networks in terms of data transmission mode, and wireless networks mainly refer to wireless sensor networks (WSN). Accordingly, the data security in smart power grid involves the data transmission security in both cable networks and WSN. WSN is an application-specific network, and a promising research in smart power grid field. In this paper, we use the digital watermarking technology to solve WSN security in smart power grid. Firstly we propose a watermark mechanism based on alternating current, including watermark generation, embedding and detection algorithms. And then we use simulation results to demonstrate its feasibility and efficiency.