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Estimation of distribution algorithms (EDAs) are stochastic optimization techniques that explore the space of potential solutions by building and sampling explicit probabilistic models of promising candidate solutions. While the primary goal of applying EDAs is to discover the global optimum or at least its accurate approximation, besides this, any EDA provides us with a sequence of probabilistic models, which in most cases hold a great deal of information about the problem. Although using problem-specific knowledge has been shown to significantly improve performance of EDAs and other evolutionary algorithms, this readily available source of problem-specific information has been practically ignored by the EDA community. This paper takes the first step toward the use of probabilistic models obtained by EDAs to speed up the solution of similar problems in the future. More specifically, we propose two approaches to biasing model building in the hierarchical Bayesian optimization algorithm (hBOA) based on knowledge automatically learned from previous hBOA runs on similar problems. We show that the proposed methods lead to substantial speedups and argue that the methods should work well in other applications that require solving a large number of problems with similar structure. 相似文献
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Chao MW Lin CH Assa J Lee TY 《IEEE transactions on visualization and computer graphics》2012,18(5):729-740
The rapid growth of motion capture data increases the importance of motion retrieval. The majority of the existing motion retrieval approaches are based on a labor-intensive step in which the user browses and selects a desired query motion clip from the large motion clip database. In this work, a novel sketching interface for defining the query is presented. This simple approach allows users to define the required motion by sketching several motion strokes over a drawn character, which requires less effort and extends the users’ expressiveness. To support the real-time interface, a specialized encoding of the motions and the hand-drawn query is required. Here, we introduce a novel hierarchical encoding scheme based on a set of orthonormal spherical harmonic (SH) basis functions, which provides a compact representation, and avoids the CPU/processing intensive stage of temporal alignment used by previous solutions. Experimental results show that the proposed approach can well retrieve the motions, and is capable of retrieve logically and numerically similar motions, which is superior to previous approaches. The user study shows that the proposed system can be a useful tool to input motion query if the users are familiar with it. Finally, an application of generating a 3D animation from a hand-drawn comics strip is demonstrated. 相似文献
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大学校园的学风是学校师生整体精神面貌的全面反映,也是学生健康成才的软环境,但是当前和谐校园学风建设出现很多不和谐现象,主要原因是受到学习态度、学习环境和教学环境的影响。要通过加强特殊学生过程管理,发挥党员先锋模范作用和培养学生科技和社会实践能力等途径促进大学生综合素质的提高,推动和谐校园学风建设。 相似文献
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The samples were fabricated by 220 t thixomolded machine made by Japan Steel Works. The microstructure from the AZ91D magnesium alloy chips to the thixomolded products was investigated. Melting behavior of the chips in thixomolding process was analyzed. The evolution processing of solid phase morphology was studied, and evolution model was put forward. The results show that microstructures in outer zone of a chip and the inner zone are obviously different, and the severe distortion takes place in the brim of the chip, where the grains are observed to be bent, distorted, even broken. The severe plastic deformation region is firstly molten, then segregation area in the inner of the chip continues to melt. The liquid phase in solid phase does not formed by liquid entrapped during shearing process, but primarily induced by internal composition segregation. 相似文献
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在计算机网络信息技术成为社会进步助力的同时,网络信息安全也面临着严重的威胁。本文简要分析了影响计算机网络信息安全的主要因素,并就这些问题对网络信息的安全防范进行了探讨。 相似文献
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本文针对城市污水处理自动控制系统进行研究,开发设计了一套基于PLC,并通过工业以太网和PROFIBUS总线联网的污水处理自控系统。该系统采用改良型A2/O工艺,在长春市北郊污水处理厂实现了污水处理的全自动控制,实际运行稳定,效果良好。 相似文献
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本文在对计算机网络战作用和对象分析的基础上,探讨了信息战背景下计算机网络攻击系统的组成和作用,提出了一个体系结构的完整解决方案和若干需要重点突破的关键技术和方向。 相似文献
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The design of a three-channel solar radiometer used to determine total columnar atmospheric water-vapor amounts is presented. The main channel is located in the 0.94-μm water-vapor band, and two other channels are located in adjacent nonabsorption regions of the solar spectrum and are used to remove scattering effects from the main channel. Water-vapor transmittance is determined by means of a modified Langley approach, and these transmittances are converted to columnar water vapor by means of a band model developed at the University of Arizona. Several cases are presented in which columnar water-vapor amounts are determined through the use of the instrument and method described here. These results are compared with sounding-balloon results. Tests of the method indicate that columnar water vapor may be retrieved with an uncertainty of less than 10%. 相似文献