遗传算法的改进及其在各向异性介质参数反演中的应用

目前，常规的遗传算法对变异进程不能实行控制，当变异概率取得较大时，就会以极大的几率使种群中很多成员出现退化的现象，从而使遗传算法变得象蒙特卡洛方法那样，把大量的计算工作浪费在无意义的空间部分，其结果使常规遗传算法不得不采用很小的变异概率。这样做的结果显然不利于算法作全局搜索，存在易陷于局部极值的缺陷。为在扩大模型空间的搜索范围和保持种群多样性的同时，又能对变异过程进行控制，通过引入Metropolis抽样准则，提出了一种改进的遗传算法。同常规算法相比，改进算法更有利于作全局搜索，具有改善遗传算法全局收敛性的效果。针对正交各向异性介质模型，用改性的遗传算法进行了各向异性多参数反演工作，以说明新方法在处理这样高度非线性最优化问题时的处理效果。     

变截面型材轧制过程的规则式专家控制算法

针对变截面型材轧制过程控制系统的复杂性和不确定性，提出了一种规则式专家控制算法，该算法基于比例模式、保持模式及极值判断法，采用模式识别技术对系统动态特征进行在线识别、推理，再通过模式匹配选取控制策略，实现对被控对象的多模态转换控制和开闭环结合控制．该控制算法不需要被控对象精确的数学模型，即能得到高性能的控制品质．     

φ8800mm焦炭塔的焊后整体热处理

介绍了直径8800mm的两台焦炭塔采取燃油法焊后整体热处理的工艺系统及热处理过程,各项 数据表明,整体热处理效果良好,完全符合设计要求。     

基于模板的关联规则挖掘算法

借用粗糙集理论中α-约简的概念,提出了一种新的基于模板的启发式关联规则挖掘算法.在已获得模板T和原信息表的基础上创建一张新的决策表,先将组成模板的描述子的知识量作为启发函数,知识量大的描述子优先成为候选α-约简集中的元素,再对候选α-约简集中的元素进行计数,从而选择满足阈值的约筒集作为最终的近似最短α-约简,即通过启发式算法求描述子集的近似最短α-约简来获取近似最优强关联规则,并以示例验证了该算法.     

The Pole Term in Linear Response Theory: An Example From the Transverse Response of the Electron Gas

In linear response theory, the dielectric response at zero frequency sometimes appears to violate the f-sum rule, which has apparent implications for causality. Here, we study the origin of this apparent discrepancy, focusing on Lindhard’s formula for the transverse response of the electron gas. At non-zero frequency, first-order poles contribute to the imaginary part of the dielectric function in the usual way. At zero frequency, second-order poles contribute in a way which forces a careful consideration of the notation of summation and integration to avoid an error. A compact formula for the contribution of the second-order poles is presented. The sense in which the f-sum rule is satisfied is discussed.     

Numerical and analytical study on deep biaxial bending collapse of thin-walled beams

The objective of the paper is to get a fundamental understanding of large rotation response of thin-walled prismatic beams subjected to biaxial bending. Square and rectangular section beams were subjected to a cantilever bending with hinge rotation up to 40°. A general purpose nonlinear FE code PAM-CRASH was used to generate results. Altogether 94 computer runs were made by changing aspect ratio, condition of the loading and bending plane with respect to principal inertia axes of the cross section. The main emphasis was placed on the determination of initial and subsequent yield loci. It was also shown that the direction of the vector of generalized strain rates obeys the normality rule. Calculated in the paper was also a critical angle defining a preferable direction of bending. The present finding can be used to better interpret results of FE calculation of automotive bodies and to develop simplified crash-oriented design tools.     

考夫曼法采观今论

围绕审知法采的连系性，考夫曼将演绎、归纳、骈推与比类连成体系。其中，演绎为仆，比类是首脑，归纳辅佐，骈推守护清白。演绎在审判训疏与说服总系统中是协和元。考夫曼归纳观的归宿是对旧的律意说服的重新组织。其创新点是说服的三阶式。他的贡献是以逻辑组织连系骈推与演绎。考夫曼认为，法采进程的本质不是逻辑推合，而是比较。律令的颁布与司法中逻辑组织的相似性在于其比类基础。考察了考夫曼比较点的选择后显示，不可抹煞两领域之间的红线。认为考夫曼的重大贡献是将比类引入审判陈说的总组织，它是原省、衡议后的第三元。在论述的基础上，为比类设定了两则对行的准法。     

Feature and rule selection in categorization tasks.

The process by which stimuli are assigned to categories has been traditionally conceptualized as bottom-up. Accordingly, stimulus features are supposed to be the fundamental units of analysis, and categorization to be accomplished on the basis of feature category correlations (cue validities). Alternatively, top-down processes are invoked, in which case one begins with a given categorization rule and then assigns stimuli to categories on that basis. Bottom-up and top-down views share a fundamental weakness, namely, they are unable to specify how features or rules, respectively, are acquired. This difficulty can be overcome if it is assumed that the process starts with neither features nor rules, but with stimuli. Then, as a result of experience with stimuli belonging to different categories, the cognitive system discovers and uses locally constructed features that maximally discriminate between the categories at hand. According to this view, the relationship between a target and a contrast category is the main factor affecting what subjects learn about each. Two experiments were conducted to explore this hypothesis. Both experiments support the notion that the relationship between the target and contrast category significantly determines which critical features are extracted as being defining of either category. In particular, it determines the level of generality of these features. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simulation of deformation and lifetime behavior of a fcc single crystal superalloy at high temperature under low-cycle fatigue loading

This work deals with the formulation of a three-dimensional crystallographic time-incremental lifetime rule for face-centered cubic (fcc) single crystals used for gas-turbine blade applications. The damage contribution rate of each slip system to the total damage is governed by the current values of the resolved shear stress and the slip rate on the corresponding slip system. The damage rule is combined with a crystallographic viscoplastic deformation model. For the nickel-base single-crystal superalloy CMSX4 at 950 °C, various strain- and stress-controlled uniaxial cyclic tests with and without hold-times can be described for different crystal orientations by one set of material parameters. For verification, simulation results for a single-crystal specimen with a notch have been compared with corresponding experimental results. The predicted lifetime is within the factor of two of the measured one.     

冰雪融水型多沙河流水库泥沙设计

以新疆喀拉喀什河乌鲁瓦提水库泥沙设计为实例，分析了冰雪融水型多沙河流的水、沙特性，并根据水库担负的任务，利用水动力学泥沙数学模型及经典的三角洲整体平衡模型，进行了多方案水库淤积率比较。在此基础上，确定了水库调水、调沙运行方式，并布设了与之相应的泄流排沙设施，得出乌鲁瓦提水库有效库容可长期保持。