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SSA-MLP模型在岩质边坡稳定性预测中的应用
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作者 侯克鹏 包广拓 孙华芬 《安全与环境学报》 CAS CSCD 北大核心 2024年第5期1795-1803,共9页
岩质边坡的力学参数量化及稳定性分析对岩质边坡灾害的防治具有重要意义。Hoek-Brown(H B)准则是一种用于确定岩体力学参数的经典方法,能反映出边坡岩体变形和位移的非线性破坏特征。在此基础上,首先,提出一种麻雀搜索算法(Sparrow Sear... 岩质边坡的力学参数量化及稳定性分析对岩质边坡灾害的防治具有重要意义。Hoek-Brown(H B)准则是一种用于确定岩体力学参数的经典方法,能反映出边坡岩体变形和位移的非线性破坏特征。在此基础上,首先,提出一种麻雀搜索算法(Sparrow Search Algorithm,SSA)改进多层感知器(Multi-Layer Perceptron,MLP)的神经网络模型,并用于边坡稳定性预测、指标敏感性分析及参数反演。其次,将收集的1085组岩质边坡的几何参数和H B准则参数等作为输入变量,极限平衡理论Bishop法求解的安全系数作为输出变量,对SSA MLP模型进行训练学习和性能评估。最后,将该模型运用于25个边坡实例,验证模型的有效性。结果显示,该模型收敛速度快、精度高,为边坡稳定性分析和参数量化提供了一种新思路。 展开更多
关键词 安全工程 边坡稳定性 HOEK-BROWN准则 多层感知器(MLP)神经网络 麻雀搜索算法 参数反演
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Two-Stage Interactive Multi-Objective Decision-Making Method Based on the Satisfactoriness Criterion
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作者 蒋尚华 江孝感 徐南荣 《Journal of Southeast University(English Edition)》 EI CAS 1998年第2期93-100,共8页
In this paper, for multi objective decision making, the defects on the commonly used interactive methods based on the satisfactoriness criterion is studied. Then a class of two stage interactive method based on the... In this paper, for multi objective decision making, the defects on the commonly used interactive methods based on the satisfactoriness criterion is studied. Then a class of two stage interactive method based on the satisfactoriness criterion is proposed for improvement with the satisfactoriness criterion being determined through the collection of the decision makers preference information. An application example is presented for illustration of applicability of the method. 展开更多
关键词 multi objective decision making satisfactoriness criterion collection of preference information
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基于决策者偏好构造的概率语言型Z-number多属性决策方法 被引量:1
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作者 王旭婷 毛军军 张新宇 《海南师范大学学报(自然科学版)》 CAS 2024年第2期135-143,共9页
由于决策环境的日益复杂,专家评价信息往往会包含专家偏好,因此有必要对专家偏好进行识别与处理。针对这一情况,提出了基于决策者偏好构造的概率语言型Z-number并应用于多属性决策问题中。首先,针对专家偏好未知的情况,提出了一种基于... 由于决策环境的日益复杂,专家评价信息往往会包含专家偏好,因此有必要对专家偏好进行识别与处理。针对这一情况,提出了基于决策者偏好构造的概率语言型Z-number并应用于多属性决策问题中。首先,针对专家偏好未知的情况,提出了一种基于修正的平均得分距离,由专家评价信息确定专家偏好。然后,依据得到的专家偏好,利用GOWPA算子与最大熵生成概率语言型Z-number。同时,获得专家评价信息的可信度,由专家可信度聚合专家信息并采用TODIM方法对方案进行排序。最后,在国家大力提倡节能减排的背景下,将所提方法应用于国家绿色矿山试点企业的选取上,验证了所提方法的有效性和可行性。 展开更多
关键词 概率语言型Z-number 偏好 GOWPA算子 最大熵 多准则群决策
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基于LMD与AO-PNN的中介轴承故障诊断方法 被引量:2
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作者 徐石 栾孝驰 +2 位作者 李彦徵 沙云东 郭小鹏 《航空发动机》 北大核心 2024年第2期114-120,共7页
针对航空发动机中介轴承受噪声干扰大、传递路径复杂导致采用传统方法难以进行故障诊断的问题,提出了一种基于局部均值分解(LMD)与相关系数-能量比-峭度准则、结合天鹰座优化算法(AO)优化概率神经网络(PNN)的中介轴承故障诊断方法。使用... 针对航空发动机中介轴承受噪声干扰大、传递路径复杂导致采用传统方法难以进行故障诊断的问题,提出了一种基于局部均值分解(LMD)与相关系数-能量比-峭度准则、结合天鹰座优化算法(AO)优化概率神经网络(PNN)的中介轴承故障诊断方法。使用LMD对传感器采集的振动信号进行分解;利用相关系数-能量比-峭度准则判决筛选分解得到的PF分量,重构筛选后的信号;计算重构信号的多尺度排列熵(MPE),以构建特征向量;通过AO优化的PNN的平滑因子,将优化后的神经网络用于中介轴承的故障诊断。基于中介轴承故障试验数据对诊断结果进行了分析,结果表明:提出的方法可以有效诊断高背景噪声、复杂路径干扰下的航空发动机中介轴承的典型故障,与粒子群优化的概率神经网络方法(PSO-PNN)和传统的PNN方法相比,其诊断准确率分别提高了3.875%和8.125%,具有较好的全局收敛性和计算鲁棒性。 展开更多
关键词 局部均值分解 故障诊断 相关系数-能量比-峭度准则 多尺度排列熵 天鹰座优化算法 中介轴承 航空发动机
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Approach for uncertain multi-objective programming problems with correlated objective functions under C_(EV) criterion 被引量:2
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作者 MENG Xiangfei WANG Ying +2 位作者 LI Chao WANG Xiaoyang LYU Maolong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第6期1197-1208,共12页
An uncertain multi-objective programming problem is a special type of mathematical multi-objective programming involving uncertain variables. This type of problem is important because there are several uncertain varia... An uncertain multi-objective programming problem is a special type of mathematical multi-objective programming involving uncertain variables. This type of problem is important because there are several uncertain variables in real-world problems.Therefore, research on the uncertain multi-objective programming problem is highly relevant, particularly those problems whose objective functions are correlated. In this paper, an approach that solves an uncertain multi-objective programming problem under the expected-variance value criterion is proposed. First, we define the basic framework of the approach and review concepts such as a Pareto efficient solution and expected-variance value criterion using an order relation between various uncertain variables.Second, the uncertain multi-objective problem is converted into an uncertain single-objective programming problem via a linear weighted method or ideal point method. Then the problem is transformed into a deterministic single objective programming problem under the expected-variance value criterion. Third, four lemmas and two theorems are proved to illustrate that the optimal solution of the deterministic single-objective programming problem is an efficient solution to the original uncertainty problem. Finally, two numerical examples are presented to validate the effectiveness of the proposed approach. 展开更多
关键词 uncertainty theory uncertain multi-objective programming expected-variance value criterion
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N-P准则下的多传感器信息融合算法设计
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作者 荀亚敏 张杰 +1 位作者 翟芸翎 翟灵瑞 《自动化仪表》 CAS 2024年第8期85-90,96,共7页
传感器是环境感知中实现高度自动化的关键组件。为了实现多传感器系统高水平的抗干扰性和鲁棒性,针对局部传感器稳定性差及精度不足的问题,创新性地提出了一种基于统计判决的多传感器信息融合算法。首先,完成了多传感器融合的基本建模,... 传感器是环境感知中实现高度自动化的关键组件。为了实现多传感器系统高水平的抗干扰性和鲁棒性,针对局部传感器稳定性差及精度不足的问题,创新性地提出了一种基于统计判决的多传感器信息融合算法。首先,完成了多传感器融合的基本建模,并设计了单传感器的单值概率特性计算方法。然后,对传统单传感中卡尔曼滤波方法进行了优化设计,消除了累计误差的影响。最后,通过引入奈曼-皮尔逊(N-P)准则完成了多维度评估的多传感器信息融合算法设计。接收者操作特征(ROC)曲线评估试验结果证明了所提算法在理论上的正确性和合理性。相比其他算法,所提算法在抗干扰性和容错性等性能方面有显著优势。实际无人机测试证明了该算法具有一定的实用性。 展开更多
关键词 多传感器融合 信息融合 统计判决 卡尔曼滤波 奈曼-皮尔逊准则 接收者操作特征曲线
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Decision-Making Method for Problem of Goal Type Based on Evaluation Criterion
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作者 蒋尚华 冯勤超 +1 位作者 江孝感 徐南荣 《Journal of Southeast University(English Edition)》 EI CAS 2002年第3期254-258,共5页
The presently existing decision making method for problem of goal type, i.e. the goal programming, is popular to some extent. In this paper we analyzed the features of the problem and the method,based on which we foun... The presently existing decision making method for problem of goal type, i.e. the goal programming, is popular to some extent. In this paper we analyzed the features of the problem and the method,based on which we found some defects of the method and pointed out these defects. To overcome these defects we absorbed the spirit and exploited concepts of evaluation criterion and the fault measure of evaluation criterion. We proposed and applied a method with an evaluation criterion, after which we also p... 展开更多
关键词 multi objective decision making evaluation criterion fault measure of evaluation criterion pre optimized objective set
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Multi Objective Decision Making Method Based on Evaluation Criterion for Problems with Linear Value Function
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作者 蒋尚华 韩勇 徐南荣 《Journal of Southeast University(English Edition)》 EI CAS 1998年第1期114-121,共8页
A class of interactive multi objective decision making method by means of evaluation criterion is proposed for problems with linear value function,in which case,the decision maker(DM) usually has only unwhole infor... A class of interactive multi objective decision making method by means of evaluation criterion is proposed for problems with linear value function,in which case,the decision maker(DM) usually has only unwhole information of weights for objectives. The concept of fault measure of the evaluation criterion is proposed to measure the deviation of the evaluation criterion from the DMs preference structure.The approach to obtain an upper boundary of fault measure of an evaluation criterion,and the approach to modify the evaluation criterion to be one with smaller fault measure,and the approach to obtain a pre optimized objective set by evaluation criterion with certain fault measure are also proposed. 展开更多
关键词 multi objective decision making evaluation criterion fault measure of evaluation criterion pre optimized objective set
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基于Multi-Fisher准则的语音混合特征提取和特征增强方法 被引量:3
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作者 赵鑫 陈晓冬 +3 位作者 常昕 齐麟 汪毅 郁道银 《纳米技术与精密工程》 CSCD 北大核心 2017年第4期317-322,共6页
提出一种基于多层Fisher(Multi-Fisher)准则的语音混合特征提取和特征增强方法,用于腹腔镜自动定位系统,通过对特定医生的语音指令准确识别,并对非特定人和非特定语音指令拒识,实现对腹腔镜的姿态控制和位置定位,保证腹腔镜位置和姿态... 提出一种基于多层Fisher(Multi-Fisher)准则的语音混合特征提取和特征增强方法,用于腹腔镜自动定位系统,通过对特定医生的语音指令准确识别,并对非特定人和非特定语音指令拒识,实现对腹腔镜的姿态控制和位置定位,保证腹腔镜位置和姿态的准确性.利用Multi-Fisher准则对特征参数分类提取和融合,并对特征参数匹配相应的Multi-Fisher比权重,配合拒识门限,提高特定人语音指令识别精度,增强系统的安全性.实验表明,相比于传统的梅尔频率倒谱系数(MFCC)特征参数,利用Multi-Fisher准则筛选后的特征参数使准确率从86.1%提高到94.2%;经过特征参数增强,准确率进一步提高到95.3%,而识别平均时间仅为283.1 ms,满足实时性要求. 展开更多
关键词 multi—Fisher准则 MFCC 语言混合特征 特征增强 嵌入式系统 实时
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基于SRCKFw-检测的多传感器融合的姿态解算算法 被引量:1
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作者 乔美英 李宛妮 +1 位作者 姚文豪 史有强 《电子测量与仪器学报》 CSCD 北大核心 2023年第5期127-135,共9页
针对惯性导航系统受模型误差和测量异常值误差的影响,姿态解算结果易出现精度差甚至发散的问题,提出了一种基于平方根容积卡尔曼滤波(square-root cubature Kalman filter,SRCKF)w-检测的多传感器姿态融合算法。利用协方差匹配法对SRCK... 针对惯性导航系统受模型误差和测量异常值误差的影响,姿态解算结果易出现精度差甚至发散的问题,提出了一种基于平方根容积卡尔曼滤波(square-root cubature Kalman filter,SRCKF)w-检测的多传感器姿态融合算法。利用协方差匹配法对SRCKF的新息序列进行自适应调整,经过调整后的新息在迭代过程中会补偿量测噪声方差阵,减小模型误差影响;再利用调整后的新息进行误差探测,提高w-检测的探测精度,并构造观测值替换准则进行误差观测值替换,解决测量异常值误差带来的影响;最后利用SRCKF进行姿态融合,陀螺仪的姿态作为状态方程,经检测替换后的加速度计和磁力计姿态作为量测方程。实验表明,所提算法可以准确估计系统姿态,与传统算法相比解算精度平均可提升62.43%,在不同条件下,算法整体性能均可得到大幅提升,并能快速进行姿态解算,保证解算精度。 展开更多
关键词 多传感器融合 平方根容积卡尔曼滤波 协方差匹配 新息自适应调整 观测值替换准则
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基于k-近邻局部线性邻域重建的多视角聚类算法
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作者 马盈仓 吴也凡 +1 位作者 邢志伟 袁林 《纺织高校基础科学学报》 CAS 2023年第3期75-83,共9页
多视图聚类旨在利用不同视图间互为差异、互相补充的信息对数据对象进行聚类,如何融合不同视角的数据是多视角聚类算法的重要问题之一。为了能更准确有效地刻画视角间的相似关系,提出一种基于k-近邻局部线性邻域重建的多视角聚类算法。... 多视图聚类旨在利用不同视图间互为差异、互相补充的信息对数据对象进行聚类,如何融合不同视角的数据是多视角聚类算法的重要问题之一。为了能更准确有效地刻画视角间的相似关系,提出一种基于k-近邻局部线性邻域重建的多视角聚类算法。首先,利用数据点间的距离分配概率近邻,得到各视角数据对应的相似矩阵;其次,通过引入k-近邻,对各视角相似矩阵进行局部线性邻域重建后融合为统一的相似矩阵;同时,引入HSIC刻画不同视角的多样性。通过将统一图的学习与多样性学习整合在统一的框架中,本模型有能力输出一个包含了各视图多样信息的融合图。通过交替迭代算法,所提模型可以被很好地优化。多个公开数据集上的对比实验证明了所提出算法的有效性优于其他已有算法。 展开更多
关键词 多视角聚类 图学习 K-近邻 局部线性 希尔伯特-施密特独立准则
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Partial Stability Approach to Consensus Problem of Linear Multi-agent Systems 被引量:8
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作者 CHEN Yang-Zhou GE Yan-Rong ZHANG Ya-Xiao 《自动化学报》 EI CSCD 北大核心 2014年第11期2573-2584,共12页
关键词 线性变换 多AGENT系统 定性方法 Hurwitz稳定性 一致性协议 增益矩阵 收敛时间 多代理系统
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Numerical failure analysis of a continuous reinforced concrete bridge under strong earthquakes using multi-scale models 被引量:3
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作者 Li Zhongxian Chen Yu Shi Yundong 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2017年第2期397-413,共17页
Previous failure analyses of bridges typically focus on substructure failure or superstructure failure separately. However, in an actual bridge, the seismic induced substructure failure and superstructure failure may ... Previous failure analyses of bridges typically focus on substructure failure or superstructure failure separately. However, in an actual bridge, the seismic induced substructure failure and superstructure failure may influence each other. Moreover, previous studies typically use simplified models to analyze the bridge failure; however, there are inherent defects in the calculation accuracy compared with using a detailed three-dimensional (3D) finite element (FE) model. Conversely, a detailed 3D FE model requires more computational costs, and a proper erosion criterion of the 3D elements is necessary. In this paper, a multi-scale FE model, including a corresponding erosion criterion, is proposed and validated that can significantly reduce computational costs with high precision by modelling a pseudo-dynamic test of an reinforced concrete (RC) pier. Numerical simulations of the seismic failures of a continuous RC bridge based on the multi-scale FE modeling method using LS-DYNA are performed. The nonlinear properties of the bridge, various connection strengths and bidirectional excitations are considered. The numerical results demonstrate that the failure of the connections will induce large pounding responses of the girders. The nonlinear deformation of the piers will aggravate the pounding damages. Furthermore, bidirectional earthquakes will induce eccentric poundingsto the girders and different failure modes to the adjacent piers. 展开更多
关键词 numerical simulation erosion criterion multi-scale finite element (FE) model failure mechanism failuremode
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Multi-features Based Approach for Moving Shadow Detection 被引量:4
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作者 周宁 周曼丽 +1 位作者 许毅平 方宝红 《Journal of Donghua University(English Edition)》 EI CAS 2004年第6期76-80,共5页
In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving... In the video-based surveillance application, moving shadows can affect the correct localization and detection of moving objects. This paper aims to present a method for shadow detection and suppression used for moving visual object detection. The major novelty of the shadow suppression is the integration of several features including photometric invariant color feature, motion edge feature, and spatial feature etc. By modifying process for false shadow detected, the averaging detection rate of moving object reaches above 90% in the test of Hall-Monitor sequence. 展开更多
关键词 MOVING SHADOW detection multi - features MOVING OBJECT DETECTION
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The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) 被引量:41
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作者 Xiang-Qun Cui Yong-Heng Zhao +52 位作者 Yao-Quan Chu Guo-Ping Li Qi Li Li-Ping Zhang Hong-Jun Su Zheng-Qiu Yao Ya-Nan Wang Xiao-Zheng Xing Xin-Nan Li Yong-Tian Zhu Gang Wang Bo-Zhong Gu A-Li Luo Xin-Qi Xu Zhen-Chao Zhang Gen-Rong Liu Hao-Tong Zhang De-Hua Yang Shu-Yun Cao Hai-Yuan Chen Jian-Jun Chen Kun-Xin Chen Ying Chen Jia-Ru Chu Lei Feng Xue-Fei Gong Yong-Hui Hou Hong-Zhuan Hu Ning-Sheng Hu Zhong-Wen Hu Lei Jia Fang-Hua Jiang Xiang Jiang Zi-Bo Jiang Ge Jin Ai-Hua Li Yan Li Ye-Ping Li Guan-QunLiu Zhi-Gang Liu Huo-Ming Shi Zheng-Hong Tang Qing-Sheng Tao Xiang-Yan Yuan Chao Zhai Jing Zhang Yan-Xia Zhang Yong Zhang Ming Zhao Fang Zhou Guo-Hua Zhou Jie Zhu Si-Cheng Zou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第9期1197-1242,共46页
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effecti... The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects. 展开更多
关键词 techniques: wide field telescope - active optics - multi fiber - spectroscopy survey - data reduction
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基于Hoek-Brown准则的地下洞室围岩稳定性分析 被引量:2
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作者 汤艳春 郑玉照 朱泽民 《人民长江》 北大核心 2023年第3期154-160,共7页
基于Hoek-Brown准则,针对该准则中与围岩稳定性相关联因素,如最大主应力σ1、最小主应力σ3、岩石强度指标GSI和岩石单轴抗压强度σci,对水电站大型地下洞室围岩稳定性的影响开展分析,建立相关数值计算模型和方案,分析σ1、σ3、GSI和... 基于Hoek-Brown准则,针对该准则中与围岩稳定性相关联因素,如最大主应力σ1、最小主应力σ3、岩石强度指标GSI和岩石单轴抗压强度σci,对水电站大型地下洞室围岩稳定性的影响开展分析,建立相关数值计算模型和方案,分析σ1、σ3、GSI和σci影响下大型地下洞室围岩变形、塑性区深度的变化规律。研究结果表明:根据不同σ1、σ3、GSI和σci条件下地下洞室围岩变形、塑性区深度的变化规律,可将围岩变形和塑性区深度划分为3个阶段:基本不变阶段、缓变阶段、陡变阶段。根据洞室围岩的塑性区特征,并结合洞室变形趋势等可将围岩变形和塑性区划分为自稳域、可控域、不可控域,得到基于Hoek-Brown准则的水电站地下洞室地应力-岩体强度-围岩稳定关系。自稳域对应地下洞室围岩处于稳定或基本处于稳定状态;可控域对应围岩有一定的变形或松弛破坏,但在一定支护策略下可控制变形或维持围岩稳定;不可控域对应围岩变形或松弛破坏较为明显,在一般支护策略下无法控制围岩变形或维持围岩稳定。根据研究成果可对Hoek-Brown准则下不同地应力大小、不同岩体强度的地下洞室进行围岩稳定性综合评判,用于系统指导地下洞室群的全过程设计和建设。 展开更多
关键词 大型地下洞室 HOEK-BROWN准则 多因素影响 围岩稳定性评判
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CONSENSUS ANALYSIS AND DESIGN OF LINEAR INTERCONNECTED MULTI-AGENT SYSTEMS 被引量:1
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作者 陈阳舟 李伟 +1 位作者 代桂平 A.Yu.ALEKSANDROV 《Acta Mathematica Scientia》 SCIE CSCD 2015年第6期1305-1317,共13页
We deal with the state consensus problem of a general Linear Interconnected Multi-Agent System (LIMAS) under a time-invariant and directed communication topology. Firstly, we propose a linear consensus protocol in a... We deal with the state consensus problem of a general Linear Interconnected Multi-Agent System (LIMAS) under a time-invariant and directed communication topology. Firstly, we propose a linear consensus protocol in a general form, which consists of state feedback of the agent itself and feedback form of the relative states between the agent and its neighbors. Secondly, a state-linear-transformation is applied to equivalently transform the state consensus problem into a partial stability problem. Based on the partial stability theory, we derive a sufficient and necessary criterion of consensus convergence, which is expressed via the Hurwitz stability of a real matrix constructed from the parameters of the agent models and the protocols, and present an analytical formula of the consensus function. Lastly, we propose a design procedure of the gain matrices in the protocol by solving a bilinear matrix inequality. 展开更多
关键词 linear interconnected multi-agent system (LIMAS) partial stability state-linear-transformation criterion of consensus convergence consensus design
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A Comparative Study of Acute Hemodynamic Effects of Multi -site Cardiac Pacing in patients with cardiac function NYHA class ⅠtoⅡ without bundle branch block 被引量:2
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作者 朱参战 崔长琮 +5 位作者 张全发 薛小临 刘维维 刘引会 《South China Journal of Cardiology》 CAS 2001年第2期101-105,共5页
Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class Ⅰ to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS ... Objective To compare the acute hemodynamic effects of five different pacing modes in patients with cardiac function NYHA class Ⅰ to Ⅱ without bundle branch block (BBB). Methods This study included 12 patients (SSS 7, Ⅲ°AVB 5) undergoing pacemaker implantation. Right ventricular apex (RVA), right ventricular outflow tract (RVOT), right ventricular bifocal (RV-Bi), left ventricular base (LVB) and bi -ventricular (Bi-Ⅴ) pacing at 60 -80 ppm were done in VVI mode prior to implantation of DDD pacemaker. The cardiac index (CI), mean pulmonary artery pressure (mPAP) and pulmonary capillary wedge pressure (PCWP) were measured with Swan - Ganz thermodilution catheter after 5 minutes of each pacing mode. Results (1) Comparing to pacing at RVA (CI: 2. 41± 0. 38 L/min per m2, PCWP: 16. 7 ±3.3 mmHg), the CI increased and the PCWP decreased significantly in pacing at RVOT(CI: 2. 63 ± 0.46, PCWP: 13. 8±2. 3), LVB(CI: 2. 78±0.52, PCWP: 14. 4±3.1), RV-Bi(CI: 2. 83±0.57, PCWP: 12. 8± 2. 5) and Bi -Ⅴ pacing (CI: 2. 94± 0.60, PCWP: 12. 7±2. 5), P < 0. 01, respectively. (2) The CI of RV-Bi and Bi-Ⅴ pacing was higher than that of RVOT and LVB pacing, the PCWP was lower, P < 0. 05, respectively. (3) There was no significant difference between RV - Bi pacing and Bi-Ⅴ pacing in CI and PCWP. Conclusion There is no significant difference between RV - Bi pacing and Bi -V pacing in the acute hemodynamic effects; however,dual - site pacing is much better than single site pacing in that aspect for patients with cardiac function NYHA class Ⅰ to Ⅱ without BBB. Among single site pacing, the RVOT and LVB pacing is better than RVA pacing in cardiac function. 展开更多
关键词 multi - site cardiac pacingHemodynamics
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Research on A Master - slave Multi - microcomputers Control System for Hollow Spindle Fancy Yarn Spinning Machine
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作者 李志蜂 陈子展 阵瑞琪 《Journal of China Textile University(English Edition)》 EI CAS 1999年第1期49-52,共4页
In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardwar... In this paper, a successfully studied and developed master - slave muld - microcomputers control system based on PC - BUS for hollow spindle fancy yarn spinning machine, mainly Its overall scheme, software and hardware construction, is introduced. Spinning experiments show that the system achieves satisfactory result. This system can solve the diftkultles of mechatronical fusion between domestic hollow splndk fancy yarn spuming muchine and its microcomputer control technology. 展开更多
关键词 hollow SPINDLE FANCY YAM spinning machine mechatrvnical fusion MASTER - SLAVE multi - microcomputers control system PC - BUS.
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On the Representation of Multi-layer Woven Structure
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作者 易洪雷 丁辛 《Journal of China Textile University(English Edition)》 EI CAS 1999年第3期14-16,共3页
A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the rein... A quantitative method is developed to identify the structures of multi-layer woven fabric in this study. Six structural parameters are selected to represent the fabric structure. With some design criteria for the reinforcement of textile composites, the relationships among the structural parameters are derived for different binding patterns of the fabric structure. The conditions, which meet the requirements of structural cell stability,are also discussed. 展开更多
关键词 multi - layer woven FABRIC structural parame-ter BINDING PATTERN TEXTILE composite .
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