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采用CAA对CATIA进行二次开发,建立了钣金零件的检验规划系统.通过钣金零件的检验规划系统得到特征的检验方法,并将所有特征对应的检验方法通过智能三维标注技术,标注到三维模型上.智能三维标注,即通过人机智能交互的方式,将所有的检验信息全部表示在三维图上,简单,直观,明了. 相似文献
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针对蛋白质交互作用关系(PPI)抽取研究中已标注语料有限而未标注生物医学自由文本易得的问题,进行了基于直推式支持向量机(TSVM)与主动学习融合的蛋白质交互作用关系抽取研究.通过自主选择最优的未标注样本加入到TSVM的训练过程中,最大程度地提高了系统的性能.实验结果表明,TSVM与主动学习融合的算法在少量已标注样本和大量未标注样本组成的混合样本集上取得了较好的学习效果,与传统的支持向量机(SVM)和TSVM算法相比,能有效地减少学习样本数,提高分类精度,在AImed语料上取得了F测度为64.12%的较好性能. 相似文献
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<正>图像检索是在图像库大量的图像中快速、准确地找到满足用户需要的图像的技术。传统的图像检索技术是采用文本标注的方法,但是这种方法缺点是标注工作量巨大,无法避免标注过程中的主观性。基于内容的图像检索技术,可以有效地克服文本标注方法的缺点,提高图像检索系统的性能,本文主要研究应用图像密度特征对图像形状进行检索的问题。 相似文献
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面对大型复杂机械研发周期长、设计量巨大等问题,采用"Top-Down"设计理念,提出了一种基于几何特征与参数关系的复杂产品三维模型架构定义方法,并通过建立模型快速定义向导和三维标准模型库,实现了复杂产品三维设计的模型快速定义过程.以某大型机械产品为实例,论证了该技术的可行性. 相似文献
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本文将变精度粗糙集模型推广到基于一般包含度的广义变精度粗糙集,利用包含度的性质讨论广义变精度粗糙集的性质。给出广义齐次包含度的定义,验证了常用的概率型包含度等均为广义齐次包含度;给出基于该广义变精度粗糙集的知识约简的方法。不同的包含度代表不同的决策语义,因此借助一般包含度研究变精度粗糙集,能够使尽可能多的有用信息被提取、挖掘,克服了基本粗糙集模型中由于要求绝对精确的包含关系而使大量有用信息丢失,进一步推广了粗糙集模型,拓宽了粗糙集在数据挖掘、知识发现、模式识别及决策分析等领域中的应用。 相似文献
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不同的机械加工方法会形成相异的表面粗糙纹理.为了探析不同粗糙纹理对齿轮传动润滑效应之影响,基于实际测量所获得的一系列粗糙度数值,进行了45组数值计算.计算结果显示:当粗糙度均方根值σ≤0.15 μm时,粗糙度对齿面油膜厚度与接触应力影响甚微;当σ>0.15 μm后,随着σ的增大,纵、横向纹理粗糙齿面接触应力均呈线性规律增加,但前者的接触应力始终大于后者.尤其是当σ≥0.55 μm时,与光滑齿面相比,纵、横向纹理粗糙齿面接触应力分别增大90%和80%;与此同时,纵向纹理膜厚值减低40%,而横向纹理膜厚值增大80%以上.在此基础上,针对纵、横向两种粗糙纹理齿面,分别建立了轮齿接触应力与齿面粗糙度之间的回归方程.最后,给出了横向纹理粗糙齿面的润滑效果要优于纵向纹理粗糙齿面的研究结论. 相似文献
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目的 针对小尺寸和特征不明显的纸杯缺陷在检测过程中易出现漏检、错检的问题,提出一种基于改进YOLOv5s模型纸杯缺陷检测方法。方法 在原始模型的Backbone部分引入CBAM注意力机制模块,提升模型的特征提取能力;增加一个YOLO检测头,将三尺度检测改为四尺度检测,提高模型对小目标和特征不明显目标的检测能力;在Neck部分借鉴加权双向特征金字塔网络BiFPN,对原始模型中的PANet进行部分改进,加强模型的特征融合能力。结果 结果显示,改进后的模型YOLOv5s–CXO精度为89.1%、召回率为90.4%、平均精度均值为89.5%,比原始模型的精度提高了1.5%、召回率提高了1.3%、平均精度均值提高了1.2%。结论 本文的改进方法有效提高了模型的检测能力,对小尺寸和特征不明显纸杯缺陷的检测效果有明显提升。 相似文献
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基于矢量空间模型和最大熵模型的词义问题解决策略 总被引:2,自引:0,他引:2
针对单义词的词义问题构建了融合触发对(trigger pair)的矢量空间模型用来进行词义相似度的计算,并以此为基础进行了词语的聚类;针对多义词的词义问题应用融合远距离上下文信息的最大熵模型进行了有导词义消歧的研究。为克服以往词义消歧评测中通过人工构造带有词义标记的测试例句而带来的覆盖程度小、主观影响大等问题,将模型的评测直接放到了词语聚类和分词歧义这两个实际的应用中。分词歧义的消解正确率达到了92%,词语聚类的结果满足进一步应用的需要。 相似文献
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影响采矿方案的因素错综复杂,为了建立科学合理的采矿方案评价体系,首先将影响因素进行分级,利用模糊数学确定各级影响因素的权重.由于噪声数据的存在,采用优势变精度粗糙集构建采矿方案评价体系,可以辨识规则间的不相容性,对条件属性进行约简,并生成最少偏好规则集,分类质量为100%.然后利用灰色关联度理论对约简后的属性进行优势分析,得到各属性对于方案的重要程度,完善采矿方案评价体系.研究结果表明:优势变精度粗糙集相对于经典粗糙集更具规则性,构建采矿方案评价体系是科学有效的. 相似文献
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Named entity recognition (NER) is essential in many natural language processing (NLP) tasks such as information extraction and document classification. A construction document usually contains critical named entities, and an effective NER method can provide a solid foundation for downstream applications to improve construction management efficiency. This study presents a NER method for Chinese construction documents based on conditional random field (CRF), including a corpus design pipeline and a CRF model. The corpus design pipeline identifies typical NER tasks in construction management, enables word-based tokenization, and controls the annotation consistency with a newly designed annotating specification. The CRF model engineers nine transformation features and seven classes of state features, covering the impacts of word position, part-of-speech (POS), and word/character states within the context. The F1-measure on a labeled construction data set is 87.9%. Furthermore, as more domain knowledge features are infused, the marginal performance improvement of including POS information will decrease, leading to a promising research direction of POS customization to improve NLP performance with limited data. 相似文献
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Raj Bridgelall Md Tahmidur Rahman Jerome F. Daleiden Denver Tolliver 《International Journal of Pavement Engineering》2018,19(1):82-87
The international roughness index (IRI) is the prevalent indicator used to assess and forecast road maintenance needs. The fixed parameters of its simulation model provide the advantage of requiring relatively few traversals to produce a consistent index. However, the static parameters also cause the model to under-represent roughness that riders experience from profile wavelengths outside of the model’s response range. A connected vehicle method that uses a similar but different index to characterise roughness can do so by accounting for all vibration wavelengths that the actual vehicles experience. This study characterises and compares the precision of each method. The field studies indicate that within seven traversals, the connected vehicle approach could achieve the same level of precision as the procedure used to produce the IRI. For a given vehicle and segment lengths longer than 50 m, the margin-of-error diminished below 1.5% after 50 traversals, and continued to improve further as the traversal volume grew. Practitioners developing new tools to evaluate pavement performance will benefit from this study by understanding the precision trade-off to recommend the best practices in utilising the connected vehicle method. 相似文献
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A systematic analysis is performed for the estimation of parameters for the Michaelis–Menten kinetic using the dynamic mechanistic model. As quality measure the Cramer–Rao lower bond (CRLB) is used. Depending on three different optimization criteria, two different measurement errors, the process operation mode (batch and fed-batch) as well as the error of the rough estimates of the parameters used for optimal experimental design the CRLB is calculated. These values are used to decide, if optimal experimental design is favourable compared to equidistant measurement points. It will be demonstrated, that optimization criteria A and E are just slightly more favourable than criteria D. The considered measurement errors give different results, but will not change the design and the precision of the parameters significant. The fed-batch process operation gives always a significant higher precision of the parameters compared to the batch mode. If the rough estimated parameter values, with which the optimal experimental design is carried out, are just known with low accuracy equidistant measurement points are in favour to model-based optimal experimental design. Using a batch process the error of the rough value of k2 (=vmax/Etot) must be smaller than 17% and of Km smaller than 40% so an optimal experimental design is worth for the parameter estimation. For fed-batch the errors of the rough estimates can be even bigger (up to 40% for k2 and 68% for Km). 相似文献