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51.
Pattern Analysis and Applications - Precise tracking of a point-target on a nonlinear trajectory is challenging and has applications ranging from traffic analysis to microscopic particle tracking....  相似文献   
52.
Lattice-based flow field modeling   总被引:2,自引:0,他引:2  
We present an approach for simulating the natural dynamics that emerge from the interaction between a flow field and immersed objects. We model the flow field using the lattice Boltzmann model (LBM) with boundary conditions appropriate for moving objects and accelerate the computation on commodity graphics hardware (GPU) to achieve real-time performance. The boundary conditions mediate the exchange of momentum between the flow field and the moving objects resulting in forces exerted by the flow on the objects as well as the back-coupling on the flow. We demonstrate our approach using soap bubbles and a feather. The soap bubbles illustrate Fresnel reflection, reveal the dynamics of the unseen flow field in which they travel, and display spherical harmonics in their undulations. Our simulation allows the user to directly interact with the flow field to influence the dynamics in real time. The free feather flutters and gyrates in response to lift and drag forces created by its motion relative to the flow. Vortices are created as the free feather falls in an otherwise quiescent flow.  相似文献   
53.
Fast Hybrid Approach for Texturing Point Models   总被引:1,自引:0,他引:1  
We present three methods for texturing point models from sample textures. The first method, the point parameterization method, uses a fast distortion‐bounded parameterization algorithm to flatten the point model's surface into one or more 2D patches. The sample texture is mapped onto these patches and alpha blending is used to minimize the discontinuity in the gaps between the patches. The second method is based on neighborhood matching where a color is assigned to each point by searching the best match within an irregular neighborhood. The hybrid method combines the former two methods, capitalizing on the advantages of both. The point parameterization method is used first to color most of the points, and the point neighborhood‐matching method is then applied to the points belonging to the gaps between the parameterized patches to minimize the discontinuity. We opt for fast texture generation, while some discontinuities may appear in the gaps of anisotropic textures.  相似文献   
54.
Many expert system researchers have reported in recent years that situation-action symbolic production rules frequently fail to provide adequate knowledge representation schemes without resorting to numeric computation. However, despite the need to integrate symbolic and quantitative computation into one coherent framework of knowledge, surprisingly few architectures have been proposed for achieving this goal. This paper explores the integration of qualitative and numeric processing in expert systems. We address the topic with respect to the construction of expert systems that perform the tasks of design and multiple fault troubleshooting. This paper shows that these tasks can be handled effectively when an appropriate interface is established between the heuristic and the numeric knowledge-based components. Specifically, we demonstrate how to interface heuristic knowledge with non-linear optimization models in order to allow an expert system greater expressiveness. An actual example is presented from the machining domain.  相似文献   
55.
TheTexture Synthesis Language (TSL) is a new high-level graphics language which provides tools for defining and generating regular and random (irregular) synthetic textures. The textures are used to fill in planar regions or can be mapped onto other surfaces. The building block for generating textures is a texture tile, i.e., a rectangular matrix oftexels (texture elements). The programmer constructs texture tiles utilizing predefined constant tiles, user-defined tiles, and texel-based operations. Tiles can be transformed and combined in various ways, and can then be used to tessellate planar polygons.This work was partially supported by the National Science Foundation under grant DCR-86-03603  相似文献   
56.
Previously obtained results for the covariance, power spectrum, and variance of the phase-induced intensity noise (PIIN) at the output of optical systems with multiple paths are modified to include the effect of non-Lorentzian source lineshapes. In the coherent limit (delay≪source coherence time), the source relaxation oscillations significantly change the spectral shape of the PIIN at the output of such multiple-path architectures  相似文献   
57.
Six studies explore the role of goal shielding in self-regulation by examining how activation of focal goals to which the individual is committed inhibits the accessibility of alternative goals. Consistent evidence was found for such goal shielding, and a number of its moderators were identified: Individuals' level of commitment to the focal goal, their degree of anxiety and depression, their need for cognitive closure, and differences in their goal-related tenacity. Moreover, inhibition of alternative goals was found to be more pronounced when they serve the same overarching purpose as the focal goal, but lessened when the alternative goals facilitate focal goal attainment. Finally, goal shielding was shown to have beneficial consequences for goal pursuit and attainment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
58.
Real time discrete shading   总被引:1,自引:1,他引:0  
A shading technique for voxel-based images, termedcongradient shading, is presented. As the surface information is not available in voxel representation, the surface normal must be recovered from the 3D discrete voxel map itself. The technique defines the normal as one of a finite set of neighborhood-estimated gradients and can thus employ precalculated look-up tables. Furthermore, a table-driven mechanism permits changing the light source parameters by merely redefining the look-up table. The technique uses only simple arithmetic operations and is thus suitable for hardware implementation. Since it has been implemented not as a post-processor, but as part of the projection pipeline of the cube architecture, congradient shading can be executed in real time. Two versions of the technique in real time. Two versions of the technique have been conceived and implemented:unidirectional shading, in which the gradient is estimated only from neighborhoods along the scan-lines;bidirectional shading, in which both horizontal and vertical components of the gradient are considered. In spite of the simplicity of the technique, the results are practically indistinguishable from images generated by conventional techniques.This work was supported by the National Science Foundation under grants DCR 8603603, CCR 8743478, CCR 8717016, and MIP 8805130  相似文献   
59.

The mechanical properties (stress–strain behavior) of three hexagonal metals, two grades of commercially pure titanium (CP-Ti) and zirconium (CP-Zr), are systematically characterized before and after heat treatment. Those materials are investigated under quasi-static (< 1 s−1) and dynamic (> 2000 s−1) tension, compression, dominant, and pure shear to draw general conclusions as to the effect of the same heat treatment and, specifically, dynamic shear failure propensity in those hexagonal materials. The results do not reveal any consistent influence of the texture on the overall quasi-static and dynamic mechanical (stress–strain) response of the investigated materials. However, when the propensity to dynamic shear failure is specifically considered, it appears that texture variations of the CP-Ti grades have more influence than purely microstructural changes resulting from the heat treatment for both materials. When no other changes than grain growth are induced, such as in the case of CP-Zr, it appears that grain growth does not significantly affect the dynamic shear failure toughness of this material. It therefore seems like no general conclusions can be drawn as to the effect of heat treatment and associated texture changes of these three hexagonal metals on their mechanical and failure properties. Thus, despite their common crystallographic features, those materials must be considered individually rather than as belonging to the general family of hexagonal metals.

  相似文献   
60.
Prostate cancer (PCa) is a common malignant cancer of the urinary system. Drug therapy, chemotherapy, and radical prostatectomy are the primary treatment methods, but drug resistance and postoperative recurrence often occur. Therefore, seeking novel anti-tumor compounds with high efficiency and low toxicity from natural products can produce a new tumor treatment method. Matijin-Su [N-(N-benzoyl-L-phenylalanyl)-O-acetyl-L-phenylalanol, MTS] is a phenylalanine dipeptide monomer compound that is isolated from the Chinese ethnic medicine Matijin (Dichondra repens Forst.). Its derivatives exhibit various pharmacological activities, especially anti-tumor. Among them, the novel MTS derivative HXL131 has a significant inhibitory effect against prostate tumor growth and metastasis. This study is designed to investigate the effects of HXL131 on the growth and metastasis of human PCa cell lines PC3 and its molecular mechanism through in vitro experiments combined with proteomics, molecular docking, and gene silencing. The in vitro results showed that HXL131 concentration dependently inhibited PC3 cell proliferation, induced apoptosis, arrested cell cycle at the G2/M phase, and inhibited cell migration capacity. A proteomic analysis and a Western blot showed that HXL131 up-regulated the expression of proliferation, apoptosis, cell cycle, and migration-related proteins CYR61, TIMP1, SOD2, IL6, SERPINE2, DUSP1, TNFSF9, OSMR, TNFRSF10D, and TNFRSF12A. Molecular docking, a cellular thermal shift assay (CETSA), and gene silencing showed that HXL131 had a strong binding affinity with DUSP1 and TNFSF9, which are important target genes for inhibiting the growth and metastasis of PC3 cells. This study demonstrates that HXL131 exhibited excellent anti-prostate cancer activity and inhibited the growth and metastasis of prostate cancer cells by regulating the expression of DUSP1 and TNFSF9.  相似文献   
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