Results 81 to 90 of about 11,003 (181)
基于半监督学习的断路器弹簧机构机械特性监测及状态评估技术研究
Gaoya dianqi, 2022 针对断路器弹簧机构机械特性监测及状态识别系统普遍存在监测类型不全、特征值提取单一、判断标准太过绝对等问题，文中提出了基于小波及半监督学习的多特征分析的断路器弹簧操动机构机械状态识别新方法。通过感知元件对分合闸线圈电流、动触头位移等信号进行采集，采用小波算法对信号进行滤波处理，分析断路器弹簧操动机构的分合闸线圈电流、动触头位移等信号与断路器异常状态之间的对应关系，提取特征值，建立半监督学习多分类网络模型，实现断路器弹簧操动机构故障的机械特性监测及状态识别。实验结果验证了此方法具有较高的诊断正确率 ...
彭跃辉 +3 more
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A Study of Xiamen-Zhangzhou-Quanzhou Metropolitan Area Development Strategy Based On Collaboration Theory [PDF]
, 2013 近年来,区域协调与合作不断涌现,都市圈已成为新时期城市竞争的焦点。协同学的创立与发展为区域一体化进一步的协调发展提供了理论基础与实践指导。研究就协同学在都市圈发展过程中的应用模式与方法展开讨论,以厦漳泉都市圈为例,采用主成分分析法和系统聚类法对序参量等关键指标进行筛选,并对不同县市进行等级划分,最终利用协同学的原理为厦漳泉都市圈的发展提出建议与对策。In recent years, regional collaboration and cooperation emerge and ...
尹秋怡, 李永玲, 王慧, 阎欣
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Hydrochemical characteristics and water quality dynamic analysis of shallow groundwater in Huaibei Plain [PDF]
Shallow groundwater is the most important source of agricultural water supply in Huaibei Plain, and its water quality has attracted wide attention.
Chunfang ZHU +7 more
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Quality Evaluation of Nine Varieties of Blueberry Based on Principal Component Analysis [PDF]
To investigate the quality characteristics of different varieties of blueberry, the quality differences on appearance, physicochemical properties, and sugar and acid composition were analyzed.
Gang LIU +9 more
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Hydrochemical characteristics and component sources of water in underground reservoirs in the Daliuta Coal Mine [PDF]
ObjectiveUnderground reservoirs in coal mines are capable of storing and purifying mine water. A deep understanding of the hydrochemical characteristics and formation mechanisms of water in underground reservoirs is identified as an important ...
Binbin JIANG +6 more
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Gaoya dianqi, 2018 根据目前基于100 MS/s超宽带检测实现多局放源识别和干扰抑制依据的局部放电波形特征提取及分类,指出实现此系统的关键技术为脉冲群波形的快速特征提取。其一般通过对脉冲群时、频域波形进行非线性映射,形成特征参数的2D平面或3D空间,再进行无监督聚类分析即可实现局放源间和噪声源的分离。针对目前应用较多的等效时频法,提出了时频自相法和时频熵法,基于指数模型和蒙特卡洛法产生仿真脉冲群,对上述3种时频算子进行了特征参数2D平面和3D空间的可分类性评定。可分类性测度值表明 ...
魏本刚, 姚周飞, 贺林, 李悦
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Gaoya dianqi, 2020 针对气体绝缘金属全封闭开关设备（gas insulated switchgear,GIS）故障频发问题,提出一种基于振动特征估计的GIS设备故障检测与分析方法;首先,提取GIS设备金属外壳振动信号特征并基于通用自回归模型建立系统的状态空间模型;然后,采用粒子滤波算法对GIS设备振动特征进行估计。同时,将特征估计值与实际测量值之间残差的绝对值作为设备故障检测指标,结合自适应阈值方法来检测故障;最后,依据振动特征残差的变化趋势实现机械故障与放电故障的隔离。对多组变电站现场GIS设备不同故障前 ...
赵洪山, 高玉峰
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Research Progress of Non-destructive Testing Technology in Beef Quality [PDF]
Beef is rich in nutrients and is one of the favored meats among consumers. Market price, consumer willingness to buy and satisfaction are affected by the quality of beef, so it is important to test the quality of beef.
Hao LIU +8 more
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Research Progress on Geographical Origin Traceability and Authentication of Citri Reticulatae Pericarpium [PDF]
Citri Reticulatae Pericarpium (CRP) has both culinary and medicinal uses, with high medicinal and economic value. However, CRP fraud such as mislabeling of the geographical origin, passing off, and aging time cheating has occurred frequently, which ...
LIU Wenwen, WEI Wan, CHEN Yan, ZHAO Jie, FU Manqin, WANG Xu
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Gaoya dianqi, 2011 介绍了基于超声检测的气体绝缘组合电器（gas insulated switchgear,GIS）典型绝缘缺陷识别技术。该技术由基于幅值模式（amplitude mode,AM）、飞行模式（flying mode,FM）、基于相位模式（phase mode,PM）的特征参数提取与判别3个主要模块组成。其中,针对AM提取的特征参数有频率成分50 Hz和100 Hz,用于区分缺陷信号与背景噪声,以及周期最大最小有效值比和周期最大最小峰值比用于区分自由金属微粒和其他超声信号 ...
司文荣, 黄华, 傅晨钊, 李彦明
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