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基于关系代数的数据立方体格的优化实现方法 被引量:2
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作者 王庆大 王海洋 《山东科技大学学报(自然科学版)》 CAS 2003年第2期92-95,共4页
多维数据立方体是数据仓库和OLAP服务器的主要数据组织模型 ,多维数据立方体格的实现占用大量的时间和空间资源。本文提出了一种基于关系代数的多维数据立方体格的实现算法 ,针对ROLAP和MOLAP的不同实现形式提供了一种综合的优化算法。
关键词 数据仓库 数据立方体格 关系代数 优化生成算法 数据组织模型 ROLAP MOLAP
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一种基于动态故障树的SBDD方法
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作者 张晓策 燕雪峰 周勇 《计算机科学》 CSCD 北大核心 2017年第9期195-199,共5页
在分析基于Pandora的动态故障树时,SBDD方法未考虑各底事件间复杂的关系,造成生成的SBDD中存在无效分支,即计算的不交化割集中存在无效割集。针对该问题,提出了一种基于动态故障树的SBDD方法,可以动态删除无效节点,避免无效分支的产生... 在分析基于Pandora的动态故障树时,SBDD方法未考虑各底事件间复杂的关系,造成生成的SBDD中存在无效分支,即计算的不交化割集中存在无效割集。针对该问题,提出了一种基于动态故障树的SBDD方法,可以动态删除无效节点,避免无效分支的产生。该方法主要包括两个方面:基于结构式排序方法的关系式排序方法和动态优化SBDD生成算法。关系式排序方法的基本思想是利用故障树的结构关系和底事件间的关系给底事件赋予不同的排序优先级。在底事件排序队列的基础上,使用动态优化SBDD生成算法来生成SBDD。在计算过程中,该算法动态删除无效的节点,使结果中不存在无效割集。实验结果表明,在相近的时间内,使用基于动态故障树的SBDD方法生成的SBDD规模更小,不交化割集数目更少且不存在无效割集。 展开更多
关键词 PANDORA 动态故障树 SBDD方法 动态优化SBDD生成算法 关系式排序方法
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Layout problem of multi-component systems arising for improving maintainability 被引量:5
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作者 罗旭 杨拥民 +2 位作者 葛哲学 温熙森 官凤娇 《Journal of Central South University》 SCIE EI CAS 2014年第5期1833-1841,共9页
To improve the mainlainability design efficiency and quality, a layout optimization method for maintainability of multi-component systems was proposed. The impact of the component layout design on system maintainabili... To improve the mainlainability design efficiency and quality, a layout optimization method for maintainability of multi-component systems was proposed. The impact of the component layout design on system maintainability was analyzed, and the layout problem for maintainability was presented. It was formulated as an optimization problem, where maintainability, layout space and distance requirement were formulated as objective functions. A multi-objective particle swarm optimization algorithm, in which the constrained-domination relationship and the update strategy of the global best were simply modified, was then used to obtain Pareto optimal solutions for the maintainability layout design problem. Finally, application in oxygen generation system of a spacecraft was studied in detail to illustrate the effectiveness and usefulness of the proposed method. The results show that the concurrent maintainability design can be carried out during the layout design process by solving the layout optimization problem for maintainability. 展开更多
关键词 MAINTAINABILITY layout problem OPTIMIZATION multi-component system multi-objective particle swarm optimization
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Modeling and optimization of unbalanced multi-stage logistic system
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作者 徐杭 徐榕 叶庆泰 《Journal of Southeast University(English Edition)》 EI CAS 2005年第2期220-224,共5页
To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each ... To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each stage, the Pruefer number is used. With theimproved decoding procedure, any Pruefer number produced stochastically can be decoded to a feasiblelogistic pattern, which can match with the capacities of the nodes of the logistic system. Withthese two innovations, a new modeling method based on parameterized interface distribution and thePriifer number coding is put forward. The corresponding genetic algorithm, named as PIP-GA, can findbetter solutions and require less computational time than st-GA. Although requiring a little moreconsumption of memory, PIP-GA is still an efficient and robust method in the modeling andoptimization of unbalanced multi-stage logistic systems. 展开更多
关键词 LOGISTICS optimization genetic algorithm Priifer number spanning tree parameterized interface distribution unbalanced multi-stage logistic system
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基于pfSense的智能网络入侵检测技术研究 被引量:1
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作者 杨磊 《信息与电脑》 2023年第3期31-33,共3页
传统基于生成树优化的网络入侵检测技术存在识别率低等问题,为了进一步提升检测率,提出基于pfSense的智能网络入侵检测技术,同时借助数据集针对实验进行验证。实验结果表明,与其他技术相比,该技术可以更好地识别攻击类型。
关键词 pfSense 智能网络入侵检测 生成优化算法
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A novel 3-layer mixed cultural evolutionary optimization framework for optimal operation of syngas production in a Texaco coal-water slurry gasifier
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作者 曹萃文 张亚坤 +3 位作者 于腾 顾幸生 辛忠 李杰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第9期1484-1501,共18页
Optimizing operational parameters for syngas production of Texaco coal-water slurry gasifier studied in this paper is a complicated nonlinear constrained problem concerning 3 BP(Error Back Propagation) neural networks... Optimizing operational parameters for syngas production of Texaco coal-water slurry gasifier studied in this paper is a complicated nonlinear constrained problem concerning 3 BP(Error Back Propagation) neural networks. To solve this model, a new 3-layer cultural evolving algorithm framework which has a population space, a medium space and a belief space is firstly conceived. Standard differential evolution algorithm(DE), genetic algorithm(GA), and particle swarm optimization algorithm(PSO) are embedded in this framework to build 3-layer mixed cultural DE/GA/PSO(3LM-CDE, 3LM-CGA, and 3LM-CPSO) algorithms. The accuracy and efficiency of the proposed hybrid algorithms are firstly tested in 20 benchmark nonlinear constrained functions. Then, the operational optimization model for syngas production in a Texaco coal-water slurry gasifier of a real-world chemical plant is solved effectively. The simulation results are encouraging that the 3-layer cultural algorithm evolving framework suggests ways in which the performance of DE, GA, PSO and other population-based evolutionary algorithms(EAs) can be improved,and the optimal operational parameters based on 3LM-CDE algorithm of the syngas production in the Texaco coalwater slurry gasifier shows outstanding computing results than actual industry use and other algorithms. 展开更多
关键词 3-Layer mixed cultural evolutionary framework Optimal operation Syngas production Coal-water slurry gasifier
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