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991.
旋量理论与矢量积法相结合求解雅可比矩阵 总被引：6，自引：0，他引：6
雅可比矩阵是描述机器人特征的重要参数之一。基于旋量理论和矢量积法,本文提出了求解雅可比矩阵的改进方法。该方法继承了旋量理论用于机器人操作的优越性,避免了采用传统DH参数法来建立局部坐标系,简化了机器人运动学、动力学的分析方法。本文针对一种三分支机器人进行了计算机仿真,结果证实了所提方法的正确性与实用性。 相似文献
992.
基于图论的复杂系统建模技术研究 总被引：1，自引：0，他引：1
建立了一种利用系统深层知识描述复杂系统的模型———SMBD,该模型将复杂系统抽象为一个由三元组描述的有向图G,并给出了图G的矩阵化表示和层次分解方法。SMBD能够根据研究需要动态扩展节点和有向边的约束,从而使该模型具有良好的可扩展能力。在SMBD的建模过程中引入了面向对象的建模思想,进一步增强了模型的可扩展性和可维护性。文章通过SMBD在复杂机电系统故障诊断中的实际应用说明了模型的适用性。 相似文献
993.
减少方差法是提高蒙特卡洛抽样效率的方法。本文结合实例分析了三种不同的计算方法用于计算球罐模糊失效概率 ,其计算效率都高于直接抽样法 相似文献
994.
Jiesong ZHANG 《深圳大学学报(理工版)》2021,38(02):208-213
In order to describe the memory effects of catastrophe events such as earthquake,typhoon and to transfer risk reasonably,we adopt a catastrophe impact model with power-law waiting time,so called the fractional compound Poisson process,to describe the underwriting risk of insurance companies and to study the pricing for catastrophe insurance-linked bonds. Firstly,we use the moment matching method to get the generalized Pareto-type approximation distribution for the cumulative losses. Then,the formula for bond price is derived under the CIR (Cox-Ingersoll-Ross) interest rate model. At last,numerical examples are used to verify the validity of the approximation for loss distribution. The results show that with the increase of memory parameter,the change trend of expected risk and bond price is opposite,and both of them may have a polymorphic trend of increasing,decreasing or both,which is closely related to the maturity level. 相似文献
995.
996.
基于非常规天然气的开发实践,逐渐形成了以“不断突破开发技术界限”为核心的“极限动用”理念,支撑中国非常规天然气规模效益开发,提出并论述了非常规天然气“极限动用”开发理论,阐述其理论内涵,梳理其系列开发技术及开发实践.理论内涵即针对“极限气藏”,采用“极限技术”,建立地下连通体,增大泄流面积,提高动用范围,追求最大单井产... 相似文献
997.
Considering the stratum anti-drilling ability,drill bit working conditions,drill bit application effect and drill bit economic benefits,the similarity of stratum anti-drilling ability was evaluated by grey relational analysis theory to screen out candidate drill bits with reference values. A new comprehensive performance evaluation model of drill bit was established by constructing the absolute ideal solution,changing the relative distance measurement method,and introducing entropy weight to work out the closeness between the candidate drill bits and ideal drill bits and select the reasonable drill bit. Through the construction of absolute ideal solution,improvement of relative distance measurement method and introduction of entropy weight,the inherent defects of TOPSIS decision analysis method,such as non-absolute order,reverse order and unreasonable weight setting,can be overcome. Simple in calculation and easy to understand,the new bit selection method has good adaptability to drill bit selection using dynamic change drill bit database. Field application has proved that the drill bits selected by the new drill bit selection method had significant increase in average rate of penetration,low wear rate,and good compatibility with the drilled formations in actual drilling. This new method of drill bit selection can be used as a technical means to select drill bits with high efficiency,long life and good economics in oilfields. 相似文献
998.
This paper presents the dynamic method for fault diagnosis based on the updating of Interval-valued belief structures （IBSs）. The classical Jeffrey＇s updating rule and the linear updating rule are extended to the framework of IBSs. Both of them are recursively used to generate global diagnosis evidence with the form of Interval basic belief assignment （IBBA） by updating the previous evidence with the incoming evidence. The diagnosis decision can be made by global diagnosis evidence. In the process of evidence updating, the similarity factors of evidence are used to determine switching between the extended Jef frey＇s and linear updating rules, and to calculate the linear combination weights. The diagnosis examples of machine rotor show that the proposed method can provide more reliable and accurate results than the diagnosis methods based on Dempster-Shafer evidence theory. 相似文献
999.
Jérémie Bourdon;Markus Nebel;Brigitte Vallée 《法国自动化、信息与运筹学；理论与应用信息》2001,35(2):163-185
Digital trees or tries are a general purpose flexible data structure that implements dictionaries built on words. The present paper is focussedon the average-case analysis of an important parameter of thistree-structure, i.e. , the stack-size. The stack-size of a tree is the memory needed by a storage-optimal preorder traversal. The analysis is carried outunder a general model in which words are produced by a source (in the information-theoretic sense)that emits symbols.Under some natural assumptions that encompass all commonlyused data models (and more), we obtain a precise average-case and probabilistic analysis of stack-size. Furthermore, we studythe dependency between the stack-size and the ordering on symbols inthe alphabet:we establish that, when the source emits independent symbols, theoptimal ordering arises when the most probable symbol is the last one in this order. https://doi.org/10.1051/ita:2001114 相似文献
1000.
对输电设备的利用份额问题建立了数学模型,提出了潮流标注图上不存在有向回路的定理,在此基础上利用图论方法开发了适合任何复杂电力系统的高效算法。 相似文献