Results 21 to 30 of about 5,854 (114)
Developmental Medicine &Child Neurology, Volume 61, Issue 3, Page E1-E35, March 2019., 2019 目的 本国际临床指南由欧洲残疾儿童学会（the European Academy of Childhood Disability，EACD）牵头制定，旨在解决发育性协调障碍（developmental coordination disorder，DCD）的定义、诊断、评估、干预以及与社会心理方面的临床应用关键问题。 方法 本指南针对五个领域的关键问题，通过文献综述和专家团队的正式讨论达成共识。为保证指南的循证基础，以“机制”、“评估”和“干预”为检索词, 对2012年更新以来提出的最新建议以及新增的“社会心理问题”和“青少年/成人”为检索词进行检索。根据牛津大学循证医学中心证据等级 (证据水平 [level of evidence, LOE]1–4) 将结果进行分类，最终转化为指南建议。并由国际 ...
Jing Hua +6 more
wiley +1 more source
World Water Policy, Volume 11, Issue 3, Page 735-750, August 2025.ABSTRACT Ensuring the efficient operation of water supply facilities in the agro‐industrial sector is critical for sustainable resource management. The article streamlines the grouping of works performed during the operation of water supply facilities in six stages, differing in purpose, duration, and frequency of work.
Ekaterina Khmel +3 more
wiley +1 more source
Ultrasound in Obstetrics &Gynecology, Volume 65, Issue 1, Page 114-121, January 2025.ABSTRACT Objective Adhesions between the uterus, bladder and anterior abdominal wall are associated with clinical sequelae, including chronic pelvic pain and dyspareunia, and can also yield complications during surgery. The transvaginal sonographic (TVS) sliding bladder sign is a minimally invasive diagnostic tool to evaluate the presence of ...
N. Min +9 more
wiley +1 more source
Risk, Hazards &Crisis in Public Policy, Volume 15, Issue 2, Page 203-235, June 2024.Abstract Misinformation presents a challenge to democracies, particularly in times of crisis. One way in which misinformation is spread is through voice messages sent via messenger groups, which enable members to share information on a larger scale. Gaining user perspectives on digital misinformation interventions as countermeasure after detection is ...
Katrin Hartwig +2 more
wiley +1 more source
Challenges in humanitarian response implementation: a large‐scale review of aid worker perspectives
Disasters, Volume 48, Issue 2, April 2024.Aid workers offer important perspectives for understanding better the most pervasive challenges that arise when implementing emergency response programming in humanitarian settings. This large sample study provides a global review of these perspectives, derived from 4,679 applications to the National NGO Program on Humanitarian Leadership, in which aid
Vincenzo Bollettino +6 more
wiley +1 more source
Gaoya dianqi, 2019 文中提出了一种气体绝缘组合电器（gas insulated switchgear,GIS）超声波检测异常信号的时频特征计算与诊断方法。首先运用希尔伯特—黄变换（Hilbert-Huang transform,HHT）得到描述超声波信号包络线的时频特征的Hilbert幅值谱。在此基础上,给出了离散条件下Hilbert边际谱与平稳性指数的计算方法,分别表示信号中各频率成分的总强度和平稳性。然后将Hilbert边际谱与平稳性指数结合起来分析,可以直观读取信号的时频特征,进而推断出异常气室的故障原因 ...
管敏渊 +7 more
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Gaoya dianqi, 2015 局部放电脉冲具有非平稳特性,采用联合时频域分析比常规的单域分析更能诊断放电的特征。因此,针对现场GIS可能存在的缺陷类型,设计了针板、悬浮和空穴的缺陷模型,提取其在工频电压下局部放电脉冲的Gabor分布特征,并采用BP人工神经网络对特征参数进行训练和测试;同时通过现场110 kV GIS的缺陷的局部放电实测,对放电脉冲Gabor特征分析的有效性进行了研究。结果表明,放电脉冲的时频特征图谱能够得到有效提取,为放电评估提供参考,特征参数的训练识别率和测试识别率较高,利于放电类型的识别。
任重
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Gaoya dianqi, 2020 断路器动作时,分合闸线圈电流特征能够反映断路器操动机构或者二次回路的运行状态,分析分合闸线圈电流特性,对断路器故障诊断具有重要意义。文中提出了基于改进集合模态分解（MEEMD）的分合闸线圈电流特征值提取方法。该方法使用MEEMD分解分合闸线圈电流信号,得到经验模态分量（IMF）,然后对分量求其瞬时频率,利用频率谱中峰值所对应坐标表征原始信号的特征值。实验结果表明,该方法能正确有效提取分合闸线圈电流特征值。
张佳, 陈志英, 陈丽安, 陈庆荣
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Gaoya dianqi, 2010 研究电晕放电辐射信号的时频特性,对于电气设备的故障诊断、在线监测以及辐射源定位等都有重要意义。笔者利用Hinich法和ADF法对电晕放电电磁辐射信号的高斯性、线性和平稳性进行了定量分析和检验,结果显示此类信号具有非高斯性、非线性和非平稳性。在此基础上,通过双谱估计和时频分析方法研究了电晕放电辐射信号的时频域特征,结果表明:放电辐射信号的持续时间较短,其频率主要分布在较高频段,分布范围较宽,能量主要集中在400800 MHz范围内,与背景噪声信号的时频域特征有明显区别,有利于对信号进行特征提取和目标识别。
刘卫东, 刘尚合, 胡小锋
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Gaoya dianqi, 2020 为了对变压器有载分接开关的运行状态进行识别,该研究首先对其运行状态和故障特征进行总结分析,针对分接开关运行过程中产生的振动信号,利用集合经验模态（EEMD）分解为多个固有模态函数分量（IMF）,再经过希尔伯特变换法,结合能量熵提取得到基于时频分析的特征向量。将特征向量输入自适应遗传算法（AGA）优化的BP神经网络模型中进行故障识别,并进行数据仿真,与相空间重构后提取的特征向量（PPDC）进行对比,验证不同网络模型下,所提方法的识别准确率和收敛速度。结果表明,以PPDC故障样本作为模型输入时 ...
曹宏
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