Results 11 to 20 of about 16,622 (118)
Gaoya dianqi, 2021 对GIS的振动信号进行分析可以及时有效的发现设备中存在的故障。在GIS设备的故障诊断中,特征提取是最为关键的步骤,文中针对单一种类的特征提取方法提取到的特征容易缺乏特异性这一缺点,提出了基于复合特征的GIS振动信号特征提取方法。首先将奇异值分解和基于总体最小二乘准则的旋转不变技术这两种时频法结合起来对振动信号中具有明确物理意义的特征量进行提取,对于没有明确物理意义的特征量,通过数据序列法中的变分模态分解和多重分形来对其进行提取;然后将这两种特征量组合得到新的特征量 ...
马星光 +5 more
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Gaoya dianqi, 2020 核熵成分分析（kernel entropy component analysis,KECA）方法在处理非线性数据集,去除冗余信息方面具有独特的优势。针对电力变压器故障诊断中有效特征提取困难,KECA中核参数选择繁琐以及忽略了样本类别信息等问题,文中提出一种自适应核函数优化学习的监督核熵成分分析特征提取方法,用于电力变压器敏感特征量的提取。首先收集电力变压器不同状态下的样本数据,并结合样本类别信息建立一个依赖数据的核函数 ...
彭丽维, 张彼德, 孔令瑜, 梅婷
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Gaoya dianqi, 2022 机械故障是断路器发生的主要故障之一，断路器分合闸过程中产生的振动信号可以有效反应其运行状态。针对现有的时频域分析等线性分析方法在提取断路器振动信号时存在的局限性，提出并探讨了一种基于相空间重构的断路器振动信号边缘特征提取方法，用于刻画断路器的非线性特征，为断路器的状态诊断提供依据。搭建故障模拟平台模拟断路器正常状态、触头磨损、线圈老化、低操作电压、合闸弹簧失效的振动信号；结合分形理论和边缘检测算法提取振动信号的边缘图像和边缘特征量，从边缘图像形态 ...
盛健 +6 more
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Institutional lessons from the Nordic management model
Conservation Biology, EarlyView.Abstract To improve wildlife management outcomes, in terms of reaching management goals and increasing legitimacy, Nordic countries have developed institutional systems involving stakeholders that aim for a more inclusive and participatory model.
Jens Nilsson +2 more
wiley +1 more source
Conservation Biology, EarlyView.Abstract The sustainability of area‐based conservation initiatives depends on their value to society. Conservation often focuses inside protected areas, but the impacts of protected areas beyond their boundaries (spillovers) are critical for their social license.
Ilaria Gliottone +5 more
wiley +1 more source
Co‐Teaching in a Virtual Intensive Study Language Programme: Insights From Team Ethnography
International Journal of Applied Linguistics, EarlyView.ABSTRACT As virtual study abroad becomes an increasingly important form of international education, little is known about how transnational teaching is organised and sustained across institutions. Using activity theory as an analytical framework and team ethnography as methodology, this study examines a virtual intensive study (VIS) programme delivered
Zhu Hua +7 more
wiley +1 more source
Dianci bileiqi, 2022 大部分的电压致热型设备由于温升不明显，故障判断难度较大，并且红外图像受到背景复杂，尺寸多的影响，导致红外图像特征提取困难，另外，大多数现有的检测工作依靠人工判别，且存在判断分歧。目前，代替人工判别的研究中，许多只利用单一的特征来表征热图像中的故障特征。针对此类问题，笔者提出一种基于多特征融合的电压致热型设备故障提取方法。此方法将红外图像多故障目标检测算法和多特征融合算法相结合，建立动态决策准则。首先提取红外图像的三种典型特征，包括颜色、纹理和轮廓特征，继而通过融合算法(串行融合、并行融合和DCA ...
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Dianci bileiqi, 2022 传统方法在进行±1 100 kV输电线路复合绝缘子缺陷多源特征及模式识别时，去噪效果不佳，无法提取准确的缺陷特征，模式识别用时较长。为此，提出一种新的方法解决以上问题。对输电线路复合绝缘子图像进行均衡化处理，实现图像增强；采用均值滤波方法实现图像去噪，并在二维熵的基础上完成图像分割。提取直线特征、斑点特征和分块统计特征构建复合绝缘子缺陷的特征集，应用BPSO算法融合直线特征、斑点特征与分块统计特征，获得复合绝缘子缺陷特征，构建输电线路复合绝缘子缺陷模式识别模型，实现复合绝缘子缺陷特征及模式的识别 ...
王建, 舒胜文, 金铭, 李勇杰
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Equine Veterinary Journal, Volume 58, Issue 6, Page 1627-1635, November 2026.Abstract Background The middle conchal sinus (MCS) (ethmoidal sinus) remains one of the least understood equine paranasal compartments. Despite recognition of its involvement in sinonasal disease, disorders of the MCS often remain underdiagnosed in the absence of computed tomographic (CT) imaging due to limited anatomical understanding and challenges ...
J.‐B. Pavard +3 more
wiley +1 more source
World Food Policy, Volume 12, Issue 2, November 2026.ABSTRACT Household food expenditure continues to be a key factor in ensuring the realization of the Human Right to Adequate Food. Particularly in Brazil, access to food can be limited by economic constraints in vulnerable families, especially among farming families, who have been more vulnerable to food insecurity in recent years in the country.
Lucas de Almeida Moura +3 more
wiley +1 more source