Results 21 to 30 of about 849 (155)
Rapid Identification and Extraction of Anthropogenically Disturbed Regions Resulting from Production and Construction Projects in Hubei Province from 2017 to 2021 [PDF]
, 2023 [Objective] This study attempted to identify and extract anthropogenic disturbance areas resulting from production and construction projects in Hubei Province from 2017 to 2021.
Hua Li +3 more
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Conservation Biology, Volume 32, Issue 3, Page 660-671, June 2018., 2018 Abstract Habitat loss is a key driver of biodiversity loss. However, hardly any long‐term time series analyses of habitat loss are available above the local scale for finer‐level habitat categories. We analysed, from a long‐term perspective, the habitat specificity of habitat‐area loss, the change in trends in habitat loss since 1989 (dissolution of ...
Marianna Biró +2 more
wiley +1 more source
Research prospects of user information detection from encrypted traffic of mobile devices [PDF]
, 2021 Encrypted traffic analysis of mobile devices can obtain multiple types of user information in an active or passive way, which provides protection for network security management and user privacy protection.The basic principles and key methods of data ...
Shunzheng YU, Tengfei ZHANG
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Study on the factors affecting the adsorption of CO2 from power plant flus gas in coal left in goaf area [PDF]
, 2023 Utilizing the adsorption characteristics of coal rock in the goaf to storage CO2 not only reduces the cost of carbon capture and separation, but also prevents spontaneous combustion of coal left in goaf area.
Fei GAO, Peng WANG, Yafei SHAN
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Zhongguo youzhi, 2023 为实现对市面上常见以及实际案件中出现的动物油样本进行快速无损识别，借助光谱分析技术和机器学习算法，基于连续分类策略，对不同动物油样本在种类及品牌/来源地方面进行区分和认定。收集了247份动物油样本(鸡油、牛油、鹅油、猪油、羊油、鸭油)，对其进行红外光谱扫描，采用自动基线校正和峰面积归一化消除样本基线漂移和量纲不一致情况；再分别采用Savitzky-Golay平滑、二项式平滑、邻域平均法、FFT滤波、一阶导数和二阶导数对红外光谱进行预处理，比较了6种预处理方法在降噪方面的差异性 ...
邱薇纶1，王晓庆2 QIU Weilun1, WANG Xiaoqing2
doaj +1 more source
Proactive migration model of SWIM service based on situation awareness [PDF]
, 2019 To solve the problem that in the system wide information management (SWIM) network,the SWIM service provider suffers from SWIM service interruption,service delay increase or service quality degradation due to malicious attack or self-failure.Therefore,a ...
Jin LEI, Shengyan ZHOU, Zhijun WU
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Gaoya dianqi, 2022 有载分接开关（on-load tap changer,OLTC）是电力变压器中唯一可以运动的机构，具有复杂的机械结构。为了解决有载分接开关机械故障诊断中样本库无法涵盖所有故障类型的问题，文中提出了一种基于驱动电机电流与振动信号的有载分接开关故障诊断方法。首先，文中研究了有载分接开关多源监测信号的特征提取方法，提出了驱动电机电流信号的持续时间、绝对值之和以及开关本体振动信号的经验模态分解能量等特征。接着，文中结合随机森林（random forest）和孤立森林（isolation forest）算法 ...
马勇 +6 more
doaj
Soft detection model of corrosion leakage risk based on KNN and random forest algorithms [PDF]
Objective The integrity management of urban gas pipeline networks demands effective risk assessment methods. Corrosion leakage risk assessment necessitates the comprehensive integration of risk assessment factors with various detection operations ...
Chengzhi LI +4 more
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Gaoya dianqi, 2020 为提高断路器机械振动信号的时—频特征分类能力、减小噪声干扰和提高断路器状态识别的准确性,提出一种基于S变换与优化随机森林算法的高压断路器机械故障诊断方法。首先,对高压断路器原始振动信号进行S变换;然后对S变换得到的时—频矩阵进行局部奇异值分解,以每个子矩阵的最大奇异值为特征向量;之后,将特征向量输入到随机森林中,以泛化误差与诊断准确率为综合指标对树的棵数进行寻优,构建最优随机森林分类器,最终实现对高压断路器机械故障状态的准确判别。对断路器实测振动数据开展对比实验,结果表明,新方法的特征类可分性好 ...
张欣 +5 more
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Gaoya dianqi, 2022 为进一步提高变压器传统故障诊断方法的准确率,提出了一种基于随机森林(RF)特征优选,结合鲸鱼算法(WOA)优化支持向量机(SVM)的变压器故障诊断方法。该方法首先利用5种常见油中溶解气体构建24维待选特征集合,其次利用RF算法中MDA指标对特征进行排序,通过序列反向搜索法优选出11维DGA特征量作为输入以消除冗余特征,最后将WOA算法用于SVM惩罚因子和核参数的优化,进而实现故障诊断。仿真结果表明,优选出的特征组合可有效提高诊断准确率,WOA-SVM故障诊断模型较PSO-SVM、GA-SVM ...
安国庆 +5 more
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