Applied Mechanics and Materials Vols. 256-259

Abstract: Combining the techniques of discrete event simulation and virtual-reality, research on real-time interactive simulation for concrete dam construction process is conducted, under the virtual-reality environment. The key technologies are discussed, including the modeling of DEM, optimization for real-time displaying of 3D scene, collision checking, real-time interaction and so on. A framework for the system of virtual-reality simulation for concrete dam construction operations based on Vega is presented. Virtual-reality supplies for construction simulation with a real-time interactive 3D simulation environment to inspect the validity of simulation model, which improves the simulation credibility and becomes a helpful tool for real-time decision making of construction operations. An example is performed to illustrate the feasibility of the system.

Abstract: HHT is widely used to analyze nonlinear and non-stationary signals. But how to extend boundaries of signals in decomposition processes is a key problem of HHT. A new technique based on response surface method (RSM), which establishes the recursive relations between sample points of signals, is presented to deal with this difficult problem. Besides, the boundary extension problem arising from HHT can be described by mathematical least squares problem but traditional gradient algorithms may diverge when the Hessian matrix of the object function of the least squares problem is non-positive. It has been proved that the generalized inverse of the linear equations (derived from the linear least squares problem) by singular value decomposition is the solution of original linear least squares problems. Thereby the divergence problem is also solved. Analysis results with respect to simulation signals and measured signals show that the method with new boundary extension technique performs successfully for HHT.

Abstract: The cable between elevator and cage was used as the object of this study, we use the finite element theory to establish the finite element model of the cable system. Then the motion response curve between the elevator and cage and the tension curve of the cable was gotten from solving the finite element equation by using the Runge-Kutta method. We have studied the effect of the length of the cable on the motion response between elevator and cage.

Abstract: A numerical method RFPA-T (Thermal Induced Rock Failure Process Analysis) code is used to study the thermal cracking processes of quasi-brittle materials subjected to high or low temperature. The numerical results indicate that thermal stress concentrating along the interface between the matrix and the embedded grains due to their different coefficient of thermal expansion (CTE). The modeling results indicate that θ-crack is generated during temperature increment as the CTE of the embedded grain is smaller than that of the matrix. However, radial-cracks emerged when the temperature decrease. The results obtained from RFPA-T code show a good agreement with experimental evidence of crack patterns caused by thermal expansion mismatch.

Abstract: In the paper, the non-metallic bulletproof helmet is analyzed in research. The way can not accurately describe and transmit the shape messages of free-curve and free-camber , in design drawing by hand, design period long and a large amount of work, a large number of data are lose and man-made muff. Advance to use the way combine Rhino software and AutoCAD 2007 software in The Computer Simulation Auxiliary Design of non-metallic bulletproof helmet, raise design level.

Abstract: In the effective combination of conflicting evidences using the Dempster-Shafer evidence theory, the first step is to reasonably measure the conflict between evidences, but there are limitations in the existing conflict measurement methods. Two new conflict measurement methods based on conjunctive combination rule are put forword, which overcome the limitations of the existing measurement methods. They have four satisfactory properties. Firstly, new methods can measure the total conflict between any pieces of evidence simultaneously, which can satisfy the interchangeability and combinability. Secondly, they overcome the operational problem of the existing binary conflict measurement methods. Thirdly, they are more suitable for people's intuitive logic reasoning. Another, their moderate complexity are easy for project implementation. So new methods have better comprehensive effect under different evidence conditions.

Abstract: The paper focuses on development and application of a decision support system BPsim.DSS, which greatly simplifies analysts work and allows them make their job more efficiently and allows prediction of consequences of taken decisions. Paper gives an example of the system deployment in production environment, a construction company and presents achieved results.

Abstract: Data streams are continuous, unbounded and coming with high speed which put forward a strong challenge against traditional association rules mining algorithms. In this paper, we give a comprehensive summary on association rules mining algorithm from three side including single-pass scanning algorithm, data processing model, memory optimization. At last, we discuss the main problems and future research directions.

Abstract: 3-D object recognition was different from 2-D one. In order to improve recognition rate, it was necessary to establish a full features base. With object as center, the paper offered a view space projection method of Multi-Camera Revolve Batch Rendering. Firstly, constructed three dimensional models for object, set positions for model and camera of top view. Then by the max panel stick to one of axis angle, copied camera with equal interval. Set up the moving path for hemisphere, and constraint to corresponding camera. In the last, established batch script with output parameters, automatic preservation random projection images for three dimensional objects.

Abstract: IPTV has great value for media provider and consumer interaction, and it also can be configured in a number of functions to complete the user selection. This paper is mainly to introduce the key technology and protocol standards of IPTV related theory and IPTV set-top box. On the basis of this study high-definition IPTV system based on ST-7109 is designed. On the ST-7109 platform, the embedded terminal broadcast of the streaming media is realized by using embedded Linux software. The text also researches ST7109 module internal resources, as well as designs good source decoder hardware circuit on the base of peripheral interface circuit of the function; it also finishes the design and analysis surround set-top box software, function module, real-time operating system Linux.