We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial c...We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial compression. Complete axial stress-strain curves were classified into four types, i.e., single peak, softening after multi-peak yield platform, hardening after multi-peak yield platform and multi-peak dur- ing softening. Observation of crack evolution on the specimen surface reveals that the deformation behavior is correlated to the closure of pre-existing joint, development of fractures in rock matrix and teeth shearing of the shear plane. To investigate the brittleness of the specimens, the ratio of the residual strength to the maximum peak strength as well as the first and last peak strains were studied. At the same joint inclination angle, the ratios between residual strength and the maximum peak strength and the last peak strains increased while the first peak strain decreased with the increase of joint continuity factor. At the same joint continuity factor, the curves of the three brittleness parameters vs. joint inclina- tion angle can either be concave or convex single-oeak or wave-shaoed.展开更多
静止变频器(static frequency converter,SFC)在运输行业、电力行业、工业自动化、新能源行业应用广泛,已成为现代工业生产中重要的一环。然而,SFC驱动电机易引发电能质量问题,以抽水蓄能电站为例,SFC起动产生的谐波导致厂用电设备损坏...静止变频器(static frequency converter,SFC)在运输行业、电力行业、工业自动化、新能源行业应用广泛,已成为现代工业生产中重要的一环。然而,SFC驱动电机易引发电能质量问题,以抽水蓄能电站为例,SFC起动产生的谐波导致厂用电设备损坏或自动装置误动作,甚至谐波传递至上级电网,影响电网的安全稳定运行。针对SFC起动过程中的谐波问题,研究非特征谐波产生机理,建立考虑限流电抗器的SFC网侧电流精准数学模型,分析得出影响非特征谐波含量的主要因素,揭示断续换相过程、电机内部扰动和外部扰动过程对非特征谐波的普适性影响规律。最后,基于某抽水蓄能电站的实际参数搭建Matlab/Simulink仿真模型,结合现场测试结果,验证所提方法对抽水蓄能电站内部非特征谐波特性分析的正确性与准确性。展开更多
尽管抽水蓄能已被广泛采用,但其作为能源存储和削峰填谷的首选解决方案,仍面临重大挑战。抽水蓄能电站内部静态变频器(static frequency converter,SFC)的启动过程会引发严重的电能质量问题,可能危及电厂设备完整性或干扰自动化系统。...尽管抽水蓄能已被广泛采用,但其作为能源存储和削峰填谷的首选解决方案,仍面临重大挑战。抽水蓄能电站内部静态变频器(static frequency converter,SFC)的启动过程会引发严重的电能质量问题,可能危及电厂设备完整性或干扰自动化系统。研究抽水蓄能电站SFC起动过程谐波传递机理,可为抽水蓄能电站治理装置布局提供理论参考。首先,建立SFC网侧电流数学模型,分析抽水蓄能电站SFC起动过程的谐波特性;其次,根据某抽水蓄能电站的实际参数,建立该电站输电线路和变压器的谐波传递模型,推导出谐波电流和电压的传递系数,结合仿真结果阐明谐波在该电站内的传递机理;最后,基于该抽水蓄能电站的实际测试结果,验证了该抽水蓄能电站谐波传递机理分析的准确性,该分析结果具有普适性,可为其他抽水蓄能电站谐波传递分析提供理论价值。展开更多
多视图聚类(Multi-View Clustering,MVC)旨在利用不同视图间的一致性和互补性来高效处理多视图数据,是大数据分析中重要的研究方向之一.然而,现有方法无法有效学习到多视图信息间的潜在联系,且缺乏考虑视图重要性差异问题.针对上述这些...多视图聚类(Multi-View Clustering,MVC)旨在利用不同视图间的一致性和互补性来高效处理多视图数据,是大数据分析中重要的研究方向之一.然而,现有方法无法有效学习到多视图信息间的潜在联系,且缺乏考虑视图重要性差异问题.针对上述这些问题,本文提出了一种基于分布对齐变分自编码器的深度多视图聚类方法(Deep Multi-View Clustering based on Distribution Aligned Variational Autoencoder,DMVCDA).首先,针对特定视图我们利用多个变分自编码器从不同视图中提取潜在特征,并对特征的分布进行对齐,以挖掘包含基本信息的潜在特征;然后,引入视图权重参数,获取共享的潜在特征;最后,在潜在特征上建立面向聚类的损失目标,使得学习到的潜在特征更适合聚类任务,从而提高聚类精度.在五个公共多视图数据集上的实验结果表明,我们的模型在精确度(ACC)、标准互信息(NMI)和纯度(Purity)等多个聚类评价指标上均表现出优异的性能.展开更多
基金supported by the National Natural Science Foundation of China (No. 11102224)the Fundamental Research Funds for the Central Universities of China(No. 2009QL05)
文摘We investigated the combined influence of joint inclination angle and joint continuity factor on deforma- tion behavior of jointed rock mass for gypsum specimens with a set of non-persistent open flaws in uni- axial compression. Complete axial stress-strain curves were classified into four types, i.e., single peak, softening after multi-peak yield platform, hardening after multi-peak yield platform and multi-peak dur- ing softening. Observation of crack evolution on the specimen surface reveals that the deformation behavior is correlated to the closure of pre-existing joint, development of fractures in rock matrix and teeth shearing of the shear plane. To investigate the brittleness of the specimens, the ratio of the residual strength to the maximum peak strength as well as the first and last peak strains were studied. At the same joint inclination angle, the ratios between residual strength and the maximum peak strength and the last peak strains increased while the first peak strain decreased with the increase of joint continuity factor. At the same joint continuity factor, the curves of the three brittleness parameters vs. joint inclina- tion angle can either be concave or convex single-oeak or wave-shaoed.
文摘静止变频器(static frequency converter,SFC)在运输行业、电力行业、工业自动化、新能源行业应用广泛,已成为现代工业生产中重要的一环。然而,SFC驱动电机易引发电能质量问题,以抽水蓄能电站为例,SFC起动产生的谐波导致厂用电设备损坏或自动装置误动作,甚至谐波传递至上级电网,影响电网的安全稳定运行。针对SFC起动过程中的谐波问题,研究非特征谐波产生机理,建立考虑限流电抗器的SFC网侧电流精准数学模型,分析得出影响非特征谐波含量的主要因素,揭示断续换相过程、电机内部扰动和外部扰动过程对非特征谐波的普适性影响规律。最后,基于某抽水蓄能电站的实际参数搭建Matlab/Simulink仿真模型,结合现场测试结果,验证所提方法对抽水蓄能电站内部非特征谐波特性分析的正确性与准确性。
文摘尽管抽水蓄能已被广泛采用,但其作为能源存储和削峰填谷的首选解决方案,仍面临重大挑战。抽水蓄能电站内部静态变频器(static frequency converter,SFC)的启动过程会引发严重的电能质量问题,可能危及电厂设备完整性或干扰自动化系统。研究抽水蓄能电站SFC起动过程谐波传递机理,可为抽水蓄能电站治理装置布局提供理论参考。首先,建立SFC网侧电流数学模型,分析抽水蓄能电站SFC起动过程的谐波特性;其次,根据某抽水蓄能电站的实际参数,建立该电站输电线路和变压器的谐波传递模型,推导出谐波电流和电压的传递系数,结合仿真结果阐明谐波在该电站内的传递机理;最后,基于该抽水蓄能电站的实际测试结果,验证了该抽水蓄能电站谐波传递机理分析的准确性,该分析结果具有普适性,可为其他抽水蓄能电站谐波传递分析提供理论价值。
文摘多视图聚类(Multi-View Clustering,MVC)旨在利用不同视图间的一致性和互补性来高效处理多视图数据,是大数据分析中重要的研究方向之一.然而,现有方法无法有效学习到多视图信息间的潜在联系,且缺乏考虑视图重要性差异问题.针对上述这些问题,本文提出了一种基于分布对齐变分自编码器的深度多视图聚类方法(Deep Multi-View Clustering based on Distribution Aligned Variational Autoencoder,DMVCDA).首先,针对特定视图我们利用多个变分自编码器从不同视图中提取潜在特征,并对特征的分布进行对齐,以挖掘包含基本信息的潜在特征;然后,引入视图权重参数,获取共享的潜在特征;最后,在潜在特征上建立面向聚类的损失目标,使得学习到的潜在特征更适合聚类任务,从而提高聚类精度.在五个公共多视图数据集上的实验结果表明,我们的模型在精确度(ACC)、标准互信息(NMI)和纯度(Purity)等多个聚类评价指标上均表现出优异的性能.
