In order to diagnose gear shifting process in automated manual transmission（AMT）,a semi-quantitative signed directed graph（SDG）model is applied.Mathematical models are built by analysis of the power train dynamic ...In order to diagnose gear shifting process in automated manual transmission（AMT）,a semi-quantitative signed directed graph（SDG）model is applied.Mathematical models are built by analysis of the power train dynamic and the gear shifting control process.The SDG model is built based on related priori knowledge.By calculating the fuzzy membership degree of each compatible passway and its possible fault source,we get the possibilities of failure for each possible fault source.We begin with the nodes with the maximum possibility of failure in order to find the failed part.The diagnosis example shows that it is feasible to use the semi-quantitative SDG model for fault diagnosis of the gear shifting process in AMT.展开更多
基于乡村地区老龄化日益严峻的背景,文章以乡村老年友好社区为主题,对Web of Science核心合集数据库中相关文献进行知识图谱量化分析,并根据关键词共现、国家—地区合作网络、研究热点和趋势等,将2003—2021年国外乡村老年友好社区的研...基于乡村地区老龄化日益严峻的背景,文章以乡村老年友好社区为主题,对Web of Science核心合集数据库中相关文献进行知识图谱量化分析,并根据关键词共现、国家—地区合作网络、研究热点和趋势等,将2003—2021年国外乡村老年友好社区的研究分为萌芽、起步、高速增长3个发展阶段。同时,依据关键词聚类分析结果与关键词出现频次,重点分析社区发展、人本观念和社会参与、交通设施与医疗卫生服务设施等主题内容的研究现状,总结出现有研究呈现单一要素向包含社会、物质等多维度综合环境要素转变趋势,具有明显的问题导向、社会导向与政策导向,未来研究与实践应使用动态发展视角,以应对乡村老年友好社区面临的不断变化的挑战。展开更多
The clustering of objects(individuals or variables)is one of the most used approaches to exploring multivariate data.The two most common unsupervised clustering strategies are hierarchical ascending clustering(HAC)and...The clustering of objects(individuals or variables)is one of the most used approaches to exploring multivariate data.The two most common unsupervised clustering strategies are hierarchical ascending clustering(HAC)and k-means partitioning used to identify groups of similar objects in a dataset to divide it into homogeneous groups.The proposed topological clustering of variables,called TCV,studies an homogeneous set of variables defined on the same set of individuals,based on the notion of neighborhood graphs,some of these variables are more-or-less correlated or linked according to the type quantitative or qualitative of the variables.This topological data analysis approach can then be useful for dimension reduction and variable selection.It’s a topological hierarchical clustering analysis of a set of variables which can be quantitative,qualitative or a mixture of both.It arranges variables into homogeneous groups according to their correlations or associations studied in a topological context of principal component analysis(PCA)or multiple correspondence analysis(MCA).The proposed TCV is adapted to the type of data considered,its principle is presented and illustrated using simple real datasets with quantitative,qualitative and mixed variables.The results of these illustrative examples are compared to those of other variables clustering approaches.展开更多
粉尘浓度预测可为粉尘防治提供依据。为探明国内外露天矿粉尘浓度预测研究进展,针对中国知网和Web of Science收录的粉尘浓度预测相关文献,采用CiteSpace、VOSviewer可视化图谱分析软件,从文献计量学角度对关键词进行处理,提取高频关键...粉尘浓度预测可为粉尘防治提供依据。为探明国内外露天矿粉尘浓度预测研究进展,针对中国知网和Web of Science收录的粉尘浓度预测相关文献,采用CiteSpace、VOSviewer可视化图谱分析软件,从文献计量学角度对关键词进行处理,提取高频关键词、研究热点,生成聚类图谱和热点时间轴。根据可视化分析结果,从露天矿粉尘浓度影响因素、指标体系、预测方法3个方面进行分析。结果表明:露天矿粉尘浓度的影响因素研究主要体现在生产强度和气象因素方面,选取的粉尘浓度预测指标通常有剥离量、采煤量、温度、湿度、风速、风向等;粉尘浓度预测方法主要采用神经网络、随机森林、线性回归等以及结合粒子群、遗传算法优化的组合算法预测模型。未来露天矿粉尘浓度预测研究应深入挖掘影响粉尘浓度的因素和科学建立预测指标体系,加强机器学习和智能优化算法的组合应用。展开更多
传统的交变磁场测量(Alternating current field measurement,ACFM)技术具有缺陷定量准确、无需接触等优点,但是不能检测深层缺陷;脉冲涡流检测技术(Pulsed eddy current testing,PECT)具有较好的深层缺陷检测能力,但由于采用瞬态响应...传统的交变磁场测量(Alternating current field measurement,ACFM)技术具有缺陷定量准确、无需接触等优点,但是不能检测深层缺陷;脉冲涡流检测技术(Pulsed eddy current testing,PECT)具有较好的深层缺陷检测能力,但由于采用瞬态响应信号分析方法,容易受到提离效应干扰,工程实际应用较为困难,并且定量能力弱于ACFM技术。结合ACFM和PECT的优势,提出了脉冲交变磁场测量技术(Pulsed alternating current field measurement,PACFM)。该技术采用脉冲周期信号作为激励信号源,基于瞬态脉冲响应信号,采用三维场量测量和瞬态信号分析相结合的方法实现缺陷识别与定量评估。对瞬态响应信号中能够表征磁场变化规律的特征量进行提取,通过研究发现PACFM不仅具有与ACFM等同的表面缺陷检测能力,而且具有优异的深层缺陷识别与定量评估能力,抗干扰能力强,具有较高的应用价值和前景。展开更多
The rapid development of the Network makes the comprehensive analysis as well as the quantitative evaluation of its security become more and mere important. This paper illustrates the major realization process of a Ne...The rapid development of the Network makes the comprehensive analysis as well as the quantitative evaluation of its security become more and mere important. This paper illustrates the major realization process of a Network Security Quantitative Evaluation System,which,from an intruder's angle ,established a Hierarchy Intrusion Relationship Graph by analyzing the credit degree fusion and relevancy of the secure information of the target network and by combining with powerful database information. At last, by applying some relative mathematics model and arithmetic, the paper analyzes and evaluates the security of this Network Hierarchy Intrusion Relationship Graph comprehensively and quantitatively.展开更多
基金Supported by the Basic Research Foundation of Beijing Institute of Technology(20130342035)
文摘In order to diagnose gear shifting process in automated manual transmission（AMT）,a semi-quantitative signed directed graph（SDG）model is applied.Mathematical models are built by analysis of the power train dynamic and the gear shifting control process.The SDG model is built based on related priori knowledge.By calculating the fuzzy membership degree of each compatible passway and its possible fault source,we get the possibilities of failure for each possible fault source.We begin with the nodes with the maximum possibility of failure in order to find the failed part.The diagnosis example shows that it is feasible to use the semi-quantitative SDG model for fault diagnosis of the gear shifting process in AMT.
文摘基于乡村地区老龄化日益严峻的背景,文章以乡村老年友好社区为主题,对Web of Science核心合集数据库中相关文献进行知识图谱量化分析,并根据关键词共现、国家—地区合作网络、研究热点和趋势等,将2003—2021年国外乡村老年友好社区的研究分为萌芽、起步、高速增长3个发展阶段。同时,依据关键词聚类分析结果与关键词出现频次,重点分析社区发展、人本观念和社会参与、交通设施与医疗卫生服务设施等主题内容的研究现状,总结出现有研究呈现单一要素向包含社会、物质等多维度综合环境要素转变趋势,具有明显的问题导向、社会导向与政策导向,未来研究与实践应使用动态发展视角,以应对乡村老年友好社区面临的不断变化的挑战。
文摘The clustering of objects(individuals or variables)is one of the most used approaches to exploring multivariate data.The two most common unsupervised clustering strategies are hierarchical ascending clustering(HAC)and k-means partitioning used to identify groups of similar objects in a dataset to divide it into homogeneous groups.The proposed topological clustering of variables,called TCV,studies an homogeneous set of variables defined on the same set of individuals,based on the notion of neighborhood graphs,some of these variables are more-or-less correlated or linked according to the type quantitative or qualitative of the variables.This topological data analysis approach can then be useful for dimension reduction and variable selection.It’s a topological hierarchical clustering analysis of a set of variables which can be quantitative,qualitative or a mixture of both.It arranges variables into homogeneous groups according to their correlations or associations studied in a topological context of principal component analysis(PCA)or multiple correspondence analysis(MCA).The proposed TCV is adapted to the type of data considered,its principle is presented and illustrated using simple real datasets with quantitative,qualitative and mixed variables.The results of these illustrative examples are compared to those of other variables clustering approaches.
文摘粉尘浓度预测可为粉尘防治提供依据。为探明国内外露天矿粉尘浓度预测研究进展,针对中国知网和Web of Science收录的粉尘浓度预测相关文献,采用CiteSpace、VOSviewer可视化图谱分析软件,从文献计量学角度对关键词进行处理,提取高频关键词、研究热点,生成聚类图谱和热点时间轴。根据可视化分析结果,从露天矿粉尘浓度影响因素、指标体系、预测方法3个方面进行分析。结果表明:露天矿粉尘浓度的影响因素研究主要体现在生产强度和气象因素方面,选取的粉尘浓度预测指标通常有剥离量、采煤量、温度、湿度、风速、风向等;粉尘浓度预测方法主要采用神经网络、随机森林、线性回归等以及结合粒子群、遗传算法优化的组合算法预测模型。未来露天矿粉尘浓度预测研究应深入挖掘影响粉尘浓度的因素和科学建立预测指标体系,加强机器学习和智能优化算法的组合应用。
文摘传统的交变磁场测量(Alternating current field measurement,ACFM)技术具有缺陷定量准确、无需接触等优点,但是不能检测深层缺陷;脉冲涡流检测技术(Pulsed eddy current testing,PECT)具有较好的深层缺陷检测能力,但由于采用瞬态响应信号分析方法,容易受到提离效应干扰,工程实际应用较为困难,并且定量能力弱于ACFM技术。结合ACFM和PECT的优势,提出了脉冲交变磁场测量技术(Pulsed alternating current field measurement,PACFM)。该技术采用脉冲周期信号作为激励信号源,基于瞬态脉冲响应信号,采用三维场量测量和瞬态信号分析相结合的方法实现缺陷识别与定量评估。对瞬态响应信号中能够表征磁场变化规律的特征量进行提取,通过研究发现PACFM不仅具有与ACFM等同的表面缺陷检测能力,而且具有优异的深层缺陷识别与定量评估能力,抗干扰能力强,具有较高的应用价值和前景。
文摘The rapid development of the Network makes the comprehensive analysis as well as the quantitative evaluation of its security become more and mere important. This paper illustrates the major realization process of a Network Security Quantitative Evaluation System,which,from an intruder's angle ,established a Hierarchy Intrusion Relationship Graph by analyzing the credit degree fusion and relevancy of the secure information of the target network and by combining with powerful database information. At last, by applying some relative mathematics model and arithmetic, the paper analyzes and evaluates the security of this Network Hierarchy Intrusion Relationship Graph comprehensively and quantitatively.
