Advanced Materials Research Vols. 765-767

Abstract: Discontinuous Deformation Analysis (DDA) is an emerging numerical simulation technology in rock engineering field, which could be used to analyze discontinuous blocks movement. DDA has been widely used in the areas ranging from rock slope stability analysis, underground chamber constructions to earth quake loading predictions. But so far, there is no pre and post processing program for DDA algorithm. In order to make DDA more effectively meet the needs of practical projects, and analyze the computing results more clearly, effectively and conveniently, in this paper, we use an open source VTK (Visualization Toolkit) system to visualize the results of DDA, design and implement a visualization system. We also developed friendly GUI (Graphic User Interface) based on QT. Finally, we demonstrate this tool with two project examples, which will prove that the visualization system is direct, convenient and easy to extension.

Abstract: The role of agents is the key problems in the agent-based combat simulation system. Based on the analyses of the operation roles' characteristic in the operational organization, the meaning and relation between the role concepts such as ability, duty, position and rules were analyzed. Uses these concepts and relations, propose the role's model of operation military in the battlefield. Defined the concept of the role, relation and axiom, and according with the logical formalized description, establish the role model based on ontology. Then the application of ontology in agents role modeling was detailed discussed in the background of cooperative anti-submarine warfare.

Abstract: in emergency, to improve the collaborative observation capacity of multiple platform resources, including satellite, airship and UAV (Unmanned Aerial Vehicle), an approach for deploying resources based on genetic optimization is proposed in this paper. We model the observation area into grids, and formulate the multi-platform resource deployment as a combination optimization problem, which has the goal of maximizing the cover probability of the observation area in the constraint of response time. Integer encoding is adopted in the approach to represent the positions of resources. Besides, elitism strategy is applied to improve the convergence rate. Experiment results demonstrate that the approach based on genetic can get satisfactory multi-platform resources deployment solutions in a short time, solving multi-platform resource optimization deployment problem effectively.

Abstract: A high-order parabolic equation (PE) method is applied to calculate the Bistatic RCS of two-dimensional (2-D) Electrically-large Objects. According to the shapes of objexts, Crank-Nicolson and Pade (1,0) schemes are introduced to solve the high-order PE. The numerical results demonstrate that the method not only extends the accurate angle range but also decreases the rotation times and computational time in comparison with the traditional low-order parabolic equation method.

Abstract: This paper proposes a method of reduced-reference image quality assessment based on watermarking algorithm in underwater acoustic channel. By embedding the watermark image into the original one, then delivering the combined image through the channel distortion, the same channel distortion would be exposed to the original and the watermark image. In the receiver, we use the blind extraction methods to recover the watermark image and use the watermark degradation to evaluate the quality of the original one. In this paper, we build two kinds of channels: AWGN channel and Rice fading channel to validate the feasibility of the method which would be used in the underwater acoustic channel.

Abstract: The alternating direction implicit finite-difference time-domain (ADI-FDTD) method is an unconditionally stable numerical scheme, being proposed to remove stability limitations in conventional FDTD methods. Though the computation efficiency has been improved by ADI-FDTD, significant errors have been observed at large time steps. By compensating truncation errors, a low error ADI-FDTD method in Debye media is proposed based the ER(error reduced)-ADI-FDTD, complete three dimensional equations are derived. Simulation results are anlalyzed and compared with existing methods.

Abstract: In order to improve the low efficient and the noise effect of remote sensing image reconstruction, an algorithm of adaptive dual gradient projection for sparse reconstruction of compressed sensing theory is proposed. Point to the high frequency noise of remote sensing image, the ADGPSR algorithm pursuits the projection direction in two conjudate directions, thus the high frequency noise effect is overcame. Experiment results show that, compared with the GPSR algorithm, the ADGPSR algorithm on remote sensing image improves the signals reconstruction accuracy.

Abstract: In the process of reservoir 3D modeling and display, when the data amount of the model was large, the visual model would become huge. While the oil exploration and development experts might usually pay more attention to the distribution of the cells within some layers, some areas, or some regions with specific attribute range. This article used the MeshViz and DialogViz extended module of the Open Inventor to achieve the interactive display technology including extracting slices of the 3-dimensional model and the filtering valid cells based on the specific range of the attribute value. The proposed method could extract specific slices and display the ROI region interactively, and could help the user to analyze the characteristics of three-dimensional reservoir model more efficiently.

Abstract: Spectral clustering algorithms inevitable exist computational time and memory use problems for large-scale spectral clustering, owing to compute-intensive and data-intensive. We analyse the time complexity of constructing similarity matrix, doing eigendecomposition and performing k-means and exploiting SPMD parallel structure supported by MATLAB Parallel Computing Toolbox (PCT) to decrease eigendecomposition computational time. We propose using MATLAB Distributed Computing Server to parallel construct similarity matrix, whilst using t-nearest neighbors approach to reduce memory use. Ultimately, we present clustering time, clustering quality and clustering accuracy in the experiments.

Abstract: Taking 3D borehole data for research object, an algorithm flow of volume rendering based GPU is given. According to the limited and discrete characteristics of 3D borehole data, Kriging interpolation algorithm is used to construct a regular grid data model. Ray-casting algorithm based on GPU is realized with the Visualization Toolkit (VTK). The results show that after the application of volume rendering technology, it is easy to practice the functions of arbitrary section displaying, volume clipping and volume data extracting which are practicalities.