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Guangtongxin yanjiu, 2020 噪声传递特性是传送网承载设备的典型时钟同步特性之一。针对传统选频法测试效率较低,且难以全面反映设备带内增益情况的问题,文章通过对时间偏差（TDEV）特性和噪声传递频率响应关系的分析,提出了基于TDEV的时钟噪声传递特性估算方法。实验结果表明,该方法有效解决了现有选频法在测试效率或测试精度方面的不足,可更好地满足现有承载设备时钟和面向5G超高精度的增强型同步以太时钟噪声传递特性的测试需求。
李曙方 +4 more
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Study becomes insight: Ecological learning from machine learning
Methods in Ecology and Evolution, Volume 12, Issue 11, Page 2117-2128, November 2021., 2021 Abstract The ecological and environmental science communities have embraced machine learning (ML) for empirical modelling and prediction. However, going beyond prediction to draw insights into underlying functional relationships between response variables and environmental ‘drivers’ is less straightforward.
Qiuyan Yu +5 more
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Trends and knowledge gaps in field research investigating effects of anthropogenic noise
Conservation Biology, Volume 35, Issue 1, Page 115-129, February 2021., 2021 Abstract Anthropogenic noise is a globally widespread sensory pollutant, recognized as having potentially adverse effects on function, demography, and physiology in wild animals. Human population growth and associated changes in urbanization, transportation, and resource extraction all contribute to anthropogenic noise and are predicted to increase in ...
Paul Jerem, Fiona Mathews
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Effects of spatial autocorrelation and sampling design on estimates of protected area effectiveness
Conservation Biology, Volume 34, Issue 6, Page 1452-1462, December 2020., 2020 Abstract Estimating the effectiveness of protected areas (PAs) in reducing deforestation is useful to support decisions on whether to invest in better management of areas already protected or to create new ones. Statistical matching is commonly used to assess this effectiveness, but spatial autocorrelation and regional differences in protection ...
Pablo Jose Negret +5 more
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Decision‐support tools for dynamic management
Conservation Biology, Volume 34, Issue 3, Page 589-599, June 2020., 2020 Abstract Spatial management is a valuable strategy to advance regional goals for nature conservation, economic development, and human health. One challenge of spatial management is navigating the prioritization of multiple features. This challenge becomes more pronounced in dynamic management scenarios, in which boundaries are flexible in space and ...
Heather Welch +4 more
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Dizhen xuebao, 2021 选取四川省数字测震台网2015年1月1日至2018年12月31日期间60个固定台站的三分量连续波形记录，计算了台站噪声加速度功率谱密度及相应的概率密度函数分布，统计了不同频率下的噪声功率谱密度值分布，对不同区域、不同频率下背景噪声水平的变化特征予以分析。结果表明：大部分地震台站的高频段噪声由于受到台站附近人为的、规律的作息生活和生产方式的影响，呈现明显的季节性变化和日变化，即夏季噪声水平升高，冬季降低，在农历春节期间达到全年最低值，地理空间分布特征不明显；第二类地脉动冬季噪声水平升高，夏季降低 ...
Jiangtao Xie +3 more
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Gaoya dianqi, 2021 针对当前特高压变电站噪声检测系统存在的功耗大、成本高、操作繁琐等问题,结合MEMS传感器技术研制了新型变电站噪声检测系统。以变电站噪声信号声纹特征及环境特性为基础,进行了传声器元件的选型、封装,噪声检测装置内置CORTEX M0控制器,实时计算输出机器监测噪声的A计权声压级数值至上位机监控平台,装置可并行定时及阈值触发两种采集命令进行原始数据的存储。整个检测系统可通过ZigBee实现大规模的组网监测,由上位机监控平台发送指令完成站内所有噪声检测装置的管控 ...
田昊洋 +5 more
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Gaoya dianqi, 2022 变压器外部噪声控制系统对提升变电站声环境质量具有重要意义。噪声控制系统的布放位置和结构参数选择需要依据变压器空间噪声的干涉衰减和频谱特性。目前对变压器不同位置噪声干涉衰减规律的研究很少。文中测量了山西省内某1 000 kV特高压变压器噪声，研究了变压器A、B、C相以及AB、BC相中间位置噪声干涉衰减规律。变压器A、B、C相声压级随测量点到变压器立面距离增加单调下降，略有波动，分为快衰减段和慢衰减段。变压器AB、BC相中间位置，由于近场干涉作用出现明显的振荡段。在振荡段高频分量单调下降 ...
张超, 刘国强, 芦竹茂, 俞华
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新型电力系统下负载因素对三相油浸式变压器振动噪声特性影响的试验研究
Gaoya dianqi, 2022 为了研究新型电力系统下负载因素对S13-M400/10配电变压器振动噪声特性的影响，文中在半消声室中搭建了振动噪声试验平台探究了该变压器的整体模态及其散热片的振动噪声特性，研究了谐波、不平衡负载、过励磁、过载等因素对于该变压器振动噪声特性的影响。研究结果表明，S13-M400/10配电变压器整体模态频谱复杂，固有频率较多；散热片的振动比相邻的油箱箱体部分振动更强烈；三相不平衡负载中不平衡相为B相时振动、噪声小于不平衡相为A相和C相时的振动、噪声；5次谐波下该变压器振动噪声剧增 ...
张壮壮 +5 more
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Gaoya dianqi, 2017 为了降低特高压交流变电站内变压器、电抗器等设备对电晕噪声检测的影响,根据变压器、电抗器噪声与电晕噪声的差异化时频特征,提出了一种电晕噪声提取方法,利用小波分析方法对原始电晕噪声信号进行多频带分解,采用阻带梳状滤波器对重构后的电晕噪声低频部分进行滤波处理,从中消除变压器本体及电抗器噪声,根据电晕噪声的短时脉冲性以及变压器冷却装置噪声的平稳性,利用基于谱减法的语音增强技术从电晕与冷却装置的混合噪声信号中提取出纯净电晕声信号。结果表明,利用该方法能够剔除带噪电晕声信号中的变压器、电抗器本体噪声以及冷却装置噪声,
吴晓文 +4 more
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