Results 41 to 50 of about 35,375 (133)
Gaoya dianqi, 2005 利用基于边单元的有限元法,对一台200km/h高速电力机车主变压器的油箱损耗进行了三维有限元分析和计算。由于电力机车主变压器是高漏抗,多绕组变压器,经试验（采用放大法）得到该台变压器油箱损耗为31.245kW,使用FEM二维有限元分析法计算结果为45.791kW,而采用三维有限元分析法计算结果为30.478kW。从而表明,采用三维有限元分析能够更加准确地计算主变压器油箱的涡流分布和杂散损耗,为其采取有效的屏蔽措施提供了更加可靠的科学依据。
李季, 罗隆福, 许加柱
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Policy Studies Journal, Volume 54, Issue 4, November 2026.ABSTRACT Artificial intelligence (AI) has gained much interest in public administration and public policy fields in recent years. Research on and that uses AI has so far treated it as an object or context within the broader administrative and governance discourse.
Yanto Chandra, Jianxiang Tan
wiley +1 more source
四川大学学报. 自然科学版, 2015 为进一步提高无线传感器网络节点跟踪定位精度降低能耗,提出一种多目标拥挤度差分优化的贝叶斯量化变分滤波预估WSN跟踪定位算法.首先,针对定位问题,采用贝叶斯量化变分滤波方法对目标下一位置区域进行预测,利用量化变分滤波方式选取合适的定位参与节点,并设计了量化变分滤波的多目标参数优化模型.其次,针对传统多目标优化算法寻优精度不高的问题,设计了基于种群个体拥挤度状况的多目标差分进化算法,对量化变分滤波算法参数进行优化,实现了滤波参数的多目标优化.最后,通过实验仿真表明,该算法能够有效实现目标节点的跟踪定位 ...
张睿敏, 陈钟, 李晓斌
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Making Policy Evidence Traceable: A Modular Preregistration Framework for Policy Evaluation
Policy Studies Journal, Volume 54, Issue 4, November 2026.ABSTRACT Preregistration is increasingly used in policy research, but its value depends on whether preregistered commitments can be clearly linked to reported analyses. Policy studies often involve multiple outcomes, evolving administrative data, consequential design and analytic choices, and adaptive implementation, making it difficult to distinguish ...
Yiyun Xia, Tianhao Zhao, Yuhao Ba
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基于振动信号EMD-HT时频分析的变压器有载分接开关故障诊断
Gaoya dianqi, 2012 把一列时间序列数据通过经验模态分解（empirical mode decomposition,EMD）为本征模态函数组（intrinsic mode function,IMF）,然后进行希尔伯特变换（hilbert transformation,HT）得到频谱的信号时频分析方法引用到变压器有载分接开关切换机构的振动信号分析领域。笔者介绍了该方法的理论和算法。首先采用仿真信号对该方法进行仿真验证,然后把一实测的有载分接开关故障振动信号进行基于EMD-HT方法的时频分析。通过仿真和实例信号分析结果说明 ...
张惠峰 +4 more
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Review of Policy Research, Volume 43, Issue 6, November 2026.ABSTRACT The EU policy framework for nature restoration has undergone a significant change with the adoption of the Nature Restoration Regulation. Since 2022, the EU has developed a new comprehensive and continent‐wide legislation to restore degraded ecosystems and halt biodiversity loss, which came into force in August 2024 and is an integral part of ...
Ronit Justo‐Hanani
wiley +1 more source
Gaoya dianqi, 2008 笔者基于可拓理论,提出了一种可拓评价法和可拓层次分析法相结合的变压器状态综合评估方法。首先,采用可拓层次分析法（EAHP）,将变压器状态信息之间的相对重要度采用一个可拓区间数来表示,构造可拓判断矩阵,准确计算变压器状态信息指标的权重。然后,应用可拓评价法,通过计算物元之间的关联函数同时进行定性和定量分析,实现变压器状态的综合评估。实例分析证明了该方法的正确性和有效性,为变压器的状态维修提供了合理的决策依据。
谢庆 +4 more
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A class of montonicity-preserving subdivision scheme(一类矩形域上生成保单调面的细分法)
Zhejiang Daxue xuebao. Lixue ban, 2003 离散细分法是构造曲线曲面的一类重要方法,而在实际中某些细分法要求是保形的,即初始控制点是单调的,那么细分最终生成的曲线或曲面也要求是单调的.本文用构造法构造了一类在等距离意义下矩形域上生成线性保单调曲面的细分法,该细分法具有插值性、局部性、线性不变性,齐次性和仿射不变性,并用数学归纳法证明了该类细分法的保单调性、收敛性和光滑性.
LILi(李黎), PANZhi-geng(潘志庚)
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Review of Policy Research, Volume 43, Issue 6, November 2026.ABSTRACT Nature conservation conflicts increasingly extend beyond ecological objectives to disputes over decision‐making legitimacy, institutional authority, and competing understandings of landscape and expertise. This article examines the conflict over the proposed designation of Křivoklátsko as a national park in the Czech Republic between 2021 and ...
Filip Simon
wiley +1 more source
Gaoya dianqi, 2010 以变压器油中溶解气体和变压器故障之间的关系为基础,提出了一种自适应分级多分类支持向量机变压器故障诊断方法。此方法基于模式识别特征提取的思想,采用不同的输入向量,对变压器有无故障和故障类型判别时,采取分级决策结构。采用自适应优化算法对多分类支持向量机进行优化,通过诊断效果和不同类型故障识别率的比较,得出变压器油中溶解气体的组分含量比值更能反映变压器故障类型,最终测试效果比较和支持向量机参数分析,可以看出该方法具有较高的准确率和良好的泛化能力。
杨洪, 古世甫, 陶加贵, 苟建
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