共查询到19条相似文献,搜索用时 78 毫秒
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粗集理论是对不精确、不完整、不确定的数据进行上近似和下近似的计算、分类和约简 ,寻找其隐含的关系和模式 ,产生新的规则 ,确定规则的可信度。介绍了知识库的形式化定义、知识的等价、约简等一些基本概念 ,提出了旋转机械故障诊断知识表达系统的思路 相似文献
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通过对化工生产的特点进行分析,设计出决策支持系统的总体结构并研究其特征和功能;介绍粗集理论在决策分析中的应用,利用粗集进行决策属性值的表征和属性的约简,得出简约化的决策规则。 相似文献
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将粗集理论应用到旋转机械故障的智能诊断中,在信息不完备情况下,不需要事先的假设和专家经验,在 粗糙度不变的情况下进行推理和在决策分明性不变意义下进行决策,找出其规律性,并提供规则的可信度;同时能 对旋转机械故障的知识库的进行约简,消除多余的条件属性和冗余的信息,导出最小简化决策表。 相似文献
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简述了甲醇制丙烯(MTP)工业装置的工艺流程,结合神华宁夏煤业集团50万t/a煤基甲醇制丙烯装置的运行情况,重点分析了装置开车以来遇到的主要技术问题:工艺蒸汽中杂离子超标、干燥器吸附能力差、DME反应器床层超温、激冷水系统油水分离不达标等,并介绍了相应的解决措施。生产实践表明,煤基甲醇制丙烯装置工艺路线总体设计合理,实际运行参数和设计值有较好的吻合性。 相似文献
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对于化工、石化行业使用最广的一类机器-往复式压缩机的故障诊断,提出了一种粗集集成神经网络的故障诊断专家系统模型,模型中粗集约简算法首先被用来对诊断输入数据进行约简,然后被用来对神经网络进行剪枝优化;测试结果表明该系统诊断时不仅速度快,而且正确率高,明显优于其它系统。 相似文献
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介绍了该装置加氢反应器的工艺流程和优化前运行参数。从温度,压力方面分析了造成反应器参数波动的原因,并提出了相应的解决方案。 相似文献
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在工程风险评价的失效可能性计算中,故障树重要度分析是一项重要技术,它经常遇到许多不确定、不完整的因素.采用粗糙集理论对这些不确定、不完整数据进行处理与分析,并通过埋地燃气管道的外腐蚀故障树重要度分析的实例,阐述了粗糙集理论的概念、原理、方法和应用.结果表明,粗糙集理论是一种完全基于客观的综合重要度分析方法,在工程上具有实用意义. 相似文献
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肺癌细胞的早期诊断相当困难,肺癌细胞的特征选择依据难以把握.提出根据肺癌细胞的每个特征属性对粗糙集下、上近似集的影响程度作为属性约简的依据,根据约简的结果,再采用扩展的相近关系粗糙集对肺癌细胞进行识别诊断.利用下近似集中的结果进行判断可以提高识别的准确率,利用上近似集中的结果进行判断可以降低肺癌细胞识别的漏诊率.从识别的结果来看,方法行之有效. 相似文献
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传统粗糙集分类要求苛刻和分类结果单调,既不能充分利用原有信息,也容易导致求出的属性指标的权重雷同.变精度粗糙集降低了分类的要求,不仅使分类更为丰富,而且更能充分利用原有信息,求得的属性指标权重一般不会雷同.运用变精度粗糙集和TOPSIS对我国部分上市水泥生产企业的盈利能力进行了评价.首先运用变精度粗糙集求出评价指标的权... 相似文献
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Under the circumstance of perceptual consumption, it is still challenging to grasp consumer's emotions and demands due to the large search space, diversified preferences, and easy fatigue of consumers. To reduce user fatigue and enlarge search space, a novel method was presented to design and optimize the pattern of yarn-dyed plaid fabric using the isolation niche genetic algorithm and rough set theory. Each pattern was encoded as a chromosome based on the real number code. The population was initialized and evolved using INGA to maintain the diversity. The rough set theory was adopted as the fitness function of isolation niche genetic algorithm to extract the consumer's demands. After multiple evolutions, a large set of practical patterns of the yarn-dyed plaid fabric are obtained. Experiments were carried out by 24 testers of different ages and genders. The results prove that the proposed method based on the isolation niche genetic algorithm and rough set theory is feasible and effective, supplying references to the designer. 相似文献
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Wang Shuai Hao Zhenhua Lu Huilin Liu Goudong Wang Jiaxing Xu Pengfei 《American Institute of Chemical Engineers》2012,58(2):440-455
Collisional motion of inelastic rough spheres is analyzed on the basis of the kinetic theory for flow of dense, slightly inelastic, slightly rough sphere with the consideration of gas–solid interactions. The fluctuation kinetic energy of particles is introduced to characterize the random motion of particles as a measure of the translational and rotational velocities fluctuations. The kinetic energy transport equation is proposed with the consideration of the redistribution of particle kinetic energy between the rotational and translational modes and kinetic energy dissipation by collisions. The solid pressure and viscosity are obtained in terms of the particle roughness and restitution coefficient. The partition of the random‐motion kinetic energy of inelastic rough particles between rotational and translational modes is shown to be strongly affected by the particle restitution coefficient and roughness. Hydrodynamics of gas–solid bubbling fluidized beds are numerically simulated on the basis of the kinetic theory for flow of rough spheres. Computed profiles of particles are in agreement with the experimental measurements in a bubbling fluidized bed. The effect of roughness on the distribution of energy dissipation, kinetic energy, and viscosity of particles is analyzed. © 2011 American Institute of Chemical Engineers AIChE J, 2012 相似文献