共查询到20条相似文献,搜索用时 125 毫秒
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对现有的词语相似度算法进行分析,提出一种基于知网,面向语义、可扩展的词语相似度计算方法,通过对实验结果进行分析,所提出的词语语义相似度计算方法比以前的方法更好,在计算词语相似度时,准确率更高。 相似文献
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分析了军械紧急调运方案优选决策的混合多属性特点。基于TOPSIS方法的基本原理,首先通过方案属性值的四维属性值转化,将不同类型的属性值统一成相同的形式,然后通过定义四维空间相似度,将各类型属性值的相似度计算规范到统一的度量空间,解决了含有实数、区间数、语言值和不确定语言值等多种不同决策属性值的的军械紧急调运方案优选这一混合型多属性决策问题。计算示例表明了该方法的可操性和有效性。 相似文献
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目的为了简化印刷图像质量主观评价方法。方法提出基于多尺度结构相似度的印刷图像质量评价研究,将多尺度结构相似度应用在印刷图像质量评价上。结果实验仿真表明,多尺度结构相似度模型客观评价结果与主观评价结果的相关系数最高,为0.7698,表明两者是强相关关系。结论提出的基于多尺度结构相似度的印刷图像质量评价方法,是印刷图像质量评价的一种有效的新方法。 相似文献
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目的研究在Matlab中度量彩色图像之间结构相似度的评价算法,用以评估彩色图像的质量。方法以灰度图像的结构相似度评价模型(SSIM)为基础,在Matlab中将以RGB色空间存储的彩色图像转换到亮度信息和色彩信息分别度量的YUV色彩空间中,设计算法度量彩色图像之间的亮度比较值、对比度比较值和结构比较值,综合三部分后可得彩色图像之间的结构相似度。结果实验结果表明,利用彩色结构相似度算法可以计算彩色图像与参考图像之间的相似度数值,用作质量评价,且其评价结果与人类视觉感知评价(即主观评价)结果保持一致。结论该方法可作为一种新型的彩色图像质量评价准则。 相似文献
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基于数据驱动思想,提出了一种相同工况下的滚动轴承寿命预测方法。针对轴承全寿命监测数据,根据K-means聚类算法划分轴承运行状态空间,考虑到隐马尔科夫模型主链为状态链的不足,对状态转移矩阵重新定义,将主链改进为寿命链,建立了基于改进HMM的全寿命状态驻留时间模型;将观测轴承数据、实时与建模数据进行Pearson相似度分析,构造寿命比例调节系数,实现寿命模型参数的动态修正和观测轴承寿命的自适应预测。采用美国辛辛那提大学实验中心轴承试验数据开展了应用研究,通过一组轴承全寿命数据实现了对其它轴承不同阶段及全寿命的预测,与传统的隐马尔科夫模型、灰色模型预测等方法预测结果相比,所提算法兼具较好的预测准确性和模型的泛化性。 相似文献
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This paper presents a heuristic method for the design optimization and a regression model for the performance evaluation of closed automatic assembly systems (AASs). The heuristic method is based on a queueing network model. This method can be used to set the number of pallets in an AASs and the buffer space between each pair of stations to obtain the optimal system utilization. The regression model is based on computer simulation experiments which use the system design obtained from the heuristic method. It can provide a quick method for the performance evaluation of closed automatic assembly systems. 相似文献
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构建评价指标的层次结构,运用层次分析法对评价指标进行主观赋权;利用评价指标本身的数据信息,运用熵法进行客观赋权。采用乘法合成法将二者结合建立主、客观组合赋权模型。以髋关节手术植入金属材料的选择为例,运用该组合赋权模型得到了10种候选材料的9种评价指标的权重,并用TOPSIS进行综合评价。评价结果表明,最佳髋关节手术植入材料为Ti-6A1-4V,与实践一致.验证了所得髋关节手术植入材料9种评价指标权重的合理性和可靠性,说明该模型是生物医学材料评价指标权重确定的一种有效、可行方法. 相似文献
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Translated from Izmeritel'naya Tekhnika, No. 5, pp. 13–14, May, 1988. 相似文献
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李丹 《制冷与空调(北京)》2013,(1):70-74
列举一些在变风量空调系统设计中值得思考和需要注意的问题,如系统新风量的确定、新风的分配、风道的设计、变风量末端装置的选取、内外分区系统的设计、噪声和控制等,并提出一些参考建议。 相似文献
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在用传统的相似产品法进行可靠性预计时,所选取的相似产品与评价对象之间差异较大,会造成预计结果的偏差较大。为解决这一问题,提出了一种基于"功能—运动—动作"结构化分解的可靠性预计新方法。通过明确产品的各大运动功能建立功能层,分析完成各功能的机械部件运动建立运动层,确定实现各机械部件运动的元动作运动单元建立元动作层,建立了可靠性预计的"功能—运动—元动作运动单元"层次模型。引入区间层次分析法,确定了"功能—运动—元动作运动单元"层次模型中各子代运动单元对父代运动单元的可靠性影响权重,并构建了由子代运动单元预计父代运动单元可靠性的数学模型。确定影响评价机械结构相似度的因素,构建了区间数综合评判云模型并选取与元动作运动单元相似的参考结构,以区间数综合评价云模型得出的相似度值修正参考结构的可靠性数据来预计元动作运动单元的可靠性。将元动作运动单元的可靠性预计值代入数学模型,层层预计父代运动单元的可靠性,从而得出整个产品的可靠性水平。最后以数控转台为例进行了分析,得出了可靠性预计值,并将该方法与传统方法进行了比较。结果表明,新的可靠性预计方法具有较好的可行性和较高的准确性。 相似文献
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AbstractComprehensive gene expression analysis using DNA microarrays has become a widespread technique in molecular biological research. In the biomaterials field, it is used to evaluate the biocompatibility or cellular toxicity of metals, polymers and ceramics. Studies in this field have extracted differentially expressed genes in the context of differences in cellular responses among multiple materials. Based on these genes, the effects of materials on cells at the molecular level have been examined. Expression data ranging from several to tens of thousands of genes can be obtained from DNA microarrays. For this reason, several tens or hundreds of differentially expressed genes are often present in different materials. In this review, we outline the principles of DNA microarrays, and provide an introduction to methods of extracting information which is useful for evaluating and designing biomaterials from comprehensive gene expression data. 相似文献
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Nowadays selecting the most suitable robot is a difficult task for manufacturing firms due to increase in production demands and availability of various robot models. Robot evaluation and selection can be regarded as a multiple criteria decision-making (MCDM) problem and three key issues are the assessment of robots, the determination of criteria weights and the prioritisation of alternatives. This paper aims to propose an integrated model based on hesitant 2-tuple linguistic term sets and an extended QUALIFLEX approach for handling robot selection problems with incomplete weight information. The new model can not only manage uncertain and imprecise assessment information of decision-makers with the aid of hesitant 2-tuple linguistic term sets, but also derive the important weights of criteria objectively when the weight information is incompletely known. Moreover, based on the extended QUALIFLEX algorithm, the priority orders of robots can be clearly determined and a more reasonable and credible solution can be yielded in a particular industrial application. Finally, a robot selection case study is carried out, and comparative experiments indicate the practicality and effectiveness of the proposed integrated linguistic MCDM approach. 相似文献
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Sustainability in freight transportation demands for a balance among economic, environmental, and social aspects in shipping commodities throughout a supply chain. The performance evaluation of sustainable freight transportation (SFT) systems is of prime importance as it facilitates perpetual and objective assessment for advancements towards sustainability targets. In this study, we propose a comprehensive framework to assess the sustainability performance of freight transportation systems. We pinpoint critical success factors (CSFs) affecting the performance of SFT by carrying out an extensive literature review and conducting a Delphi study to seek experts’ opinions from industry as well as academia. Further, a comprehensive hierarchical framework is developed to establish inter-relationships among these CSFs followed by prioritisation of these CSFs. The application of the proposed framework is illustrated through a case example. This framework would also serve as a reference for decision-makers in selecting the most sustainable freight transportation system. 相似文献