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Ignition Pattern Analysis for Automotive Engine Trouble Diagnosis Using Wavelet Packet Transform and Support Vector Machines 被引量:11
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作者 VONG Chi-man WONG Pak-kin +1 位作者 TAM Lap-mou ZHANG Zaiyong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第5期870-878,共9页
Engine spark ignition is an important source for diagnosis of engine faults.Based on the waveform of the ignition pattern,a mechanic can guess what may be the potential malfunctioning parts of an engine with his/her e... Engine spark ignition is an important source for diagnosis of engine faults.Based on the waveform of the ignition pattern,a mechanic can guess what may be the potential malfunctioning parts of an engine with his/her experience and handbooks.However,this manual diagnostic method is imprecise because many spark ignition patterns are very similar.Therefore,a diagnosis needs many trials to identify the malfunctioning parts.Meanwhile the mechanic needs to disassemble and assemble the engine parts for verification.To tackle this problem,an intelligent diagnosis system was established based on ignition patterns.First,the captured patterns were normalized and compressed.Then wavelet packet transform(WPT) was employed to extract the representative features of the ignition patterns.Finally,a classification system was constructed by using multi-class support vector machines(SVM) and the extracted features.The classification system can intelligently classify the most likely engine fault so as to reduce the number of diagnosis trials.Experimental results show that SVM produces higher diagnosis accuracy than the traditional multilayer feedforward neural network.This is the first trial on the combination of WPT and SVM to analyze ignition patterns and diagnose automotive engines. 展开更多
关键词 automotive engine ignition pattern diagnosis pattern classification wavelet packet transform support vector machines.
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基于自适应反馈机制的小差异化图像纹理特征信息数据检索
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作者 刘洋 毛克明 《江苏大学学报(自然科学版)》 CAS 北大核心 2025年第1期73-81,共9页
针对小差异化图像纹理相似度和噪声等因素导致纹理特征挖掘效果较差的问题,设计一种自适应反馈结合局部二值机制的小差异化图像纹理特征挖掘方法.使用规范割策略将图像数据各点拟作节点,使用节点间的连接线权重计算2点的相似度,采用支... 针对小差异化图像纹理相似度和噪声等因素导致纹理特征挖掘效果较差的问题,设计一种自适应反馈结合局部二值机制的小差异化图像纹理特征挖掘方法.使用规范割策略将图像数据各点拟作节点,使用节点间的连接线权重计算2点的相似度,采用支持向量机训练图像属性参数分类图像属性,进一步归纳图像类别.运用跳跃连接方法传输图像数据,将数据引入卷积神经网络剔除图像噪声.将中心点像素值当作反馈因子,创建自适应反馈判定条件,利用局部二值模式实现小差异化图像纹理特征挖掘.在MATLAB平台进行试验,从卷积神经网络收敛性、图像频谱纹理单元数、平均准确率、图像数据匹配度等方面进行了分析,分析结果表明:随着迭代次数不断增加,精度损失逐渐降低,基本收敛到稳定值,达到了预期训练效果;所提出方法挖掘的图像频谱纹理单元数3800个以上,更贴合人眼视觉信息;平均准确率为0.87,准确率@1、准确率@5和准确率@10的平均值分别为0.90、0.84和0.85;挖掘耗时低于5 s,图像数据匹配度高于90.3%,验证了所提出方法可在图像纹理特征识别操作中发挥应有作用. 展开更多
关键词 小差异化图像 纹理特征 数据挖掘 自适应反馈 属性分类 跳跃连接 局部二值模式 支持向量机
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Fast Training of Support Vector Machines Using Error-Center-Based Optimization 被引量:3
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作者 L. Meng, Q. H. Wu Department of Electrical Engineering and Electronics, The University of Liverpool, Liverpool, L69 3GJ, UK 《International Journal of Automation and computing》 EI 2005年第1期6-12,共7页
This paper presents a new algorithm for Support Vector Machine (SVM) training, which trains a machine based on the cluster centers of errors caused by the current machine. Experiments with various training sets show t... This paper presents a new algorithm for Support Vector Machine (SVM) training, which trains a machine based on the cluster centers of errors caused by the current machine. Experiments with various training sets show that the computation time of this new algorithm scales almost linear with training set size and thus may be applied to much larger training sets, in comparison to standard quadratic programming (QP) techniques. 展开更多
关键词 support vector machines quadratic programming pattern classification machine learning
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Forecasting regional economic growth using support vector machine model 被引量:1
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作者 ZHANG Kun 《Ecological Economy》 2019年第3期186-192,共7页
Support vector machine(SVM)is a new technology in data mining.It is a new tool to solve machine learning problems with the help of optimization.Support vector machines belong to a new machine learning that extends fro... Support vector machine(SVM)is a new technology in data mining.It is a new tool to solve machine learning problems with the help of optimization.Support vector machines belong to a new machine learning that extends from statistical learning theory.Its structure is relatively simple,with good generalization ability and global optimality.Support vector machine has provided a unified framework for solving finite sample learning problems,and there are many solutions proposed.It can deal with those more complex problems and introduce the characteristics of the support vector machine model.Aiming at the application of the model in economic forecasting,a method to improve the prediction accuracy of the model is proposed.The theoretical analysis and practical application verification are performed,which shows that this method can obtain more accurate prediction results. 展开更多
关键词 support VECTOR MACHINE pattern RECOGNITION ECONOMIC growth FORECAST
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Least Squares Support Vector Machine Based Real-Time Fault Diagnosis Model for Gas Path Parameters of Aero Engines 被引量:1
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作者 王旭辉 黄圣国 +2 位作者 王烨 刘永建 舒平 《Journal of Southwest Jiaotong University(English Edition)》 2009年第1期22-26,共5页
Least squares support vector machine (LS-SVM) is applied in gas path fault diagnosis for aero engines. Firstly, the deviation data of engine cruise are analyzed. Then, model selection is conducted using pattern sear... Least squares support vector machine (LS-SVM) is applied in gas path fault diagnosis for aero engines. Firstly, the deviation data of engine cruise are analyzed. Then, model selection is conducted using pattern search method. Finally, by decoding aircraft communication addressing and reporting system (ACARS) report, a real-time cruise data set is acquired, and the diagnosis model is adopted to process data. In contrast to the radial basis function (RBF) neutral network, LS-SVM is more suitable for real-time diagnosis of gas turbine engine. 展开更多
关键词 Engine diagnosis Gas path Least squares support vector machine pattern search
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Hooke and Jeeves algorithm for linear support vector machine 被引量:1
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作者 Yeqing Liu Sanyang Liu Mingtao Gu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第1期138-141,共4页
Coordinate descent method is a unconstrained optimization technique. When it is applied to support vector machine (SVM), at each step the method updates one component of w by solving a one-variable sub-problem while... Coordinate descent method is a unconstrained optimization technique. When it is applied to support vector machine (SVM), at each step the method updates one component of w by solving a one-variable sub-problem while fixing other components. All components of w update after one iteration. Then go to next iteration. Though the method converges and converges fast in the beginning, it converges slow for final convergence. To improve the speed of final convergence of coordinate descent method, Hooke and Jeeves algorithm which adds pattern search after every iteration in coordinate descent method was applied to SVM and a global Newton algorithm was used to solve one-variable subproblems. We proved the convergence of the algorithm. Experimental results show Hooke and Jeeves' method does accelerate convergence specially for final convergence and achieves higher testing accuracy more quickly in classification. 展开更多
关键词 support vector machine CLASSIFICATION pattern search Hooke and Jeeves coordinate descent global Newton algorithm.
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深部破碎软岩巷道超前控顶加固及控制爆破技术
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作者 汪禹 张西良 +4 位作者 李龙福 殷登才 崔正荣 王小兵 金科 《爆破》 CSCD 北大核心 2024年第3期75-84,共10页
随着矿山开采深度逐渐增加,深部破碎围岩工程地质条件转为复杂多变,极大程度上影响巷道等工程施工过程及后续使用安全;为确保深部破碎软岩巷道施工过程中安全及质量,提出了软岩巷道超前控顶加固及控制爆破技术。针对钟九铁矿-550 m水平... 随着矿山开采深度逐渐增加,深部破碎围岩工程地质条件转为复杂多变,极大程度上影响巷道等工程施工过程及后续使用安全;为确保深部破碎软岩巷道施工过程中安全及质量,提出了软岩巷道超前控顶加固及控制爆破技术。针对钟九铁矿-550 m水平6号交岔点岩体裂隙极为发育、稳定性差等特点,拟采用超前控顶措施加固顶板围岩,提高深部破碎软岩巷道的承载力。为便于6号交岔点掘进施工,沿6号交岔点东北侧方向划分17个掘进区,并采用“四步”台阶法分段施工。针对同段起爆数码电子雷管,起爆器系统可随机设置单发雷管起爆间隔时间为3~5 ms,实现同段炮孔单孔单响,降低爆破振动对6号交岔点影响。根据不同掘进区总体岩性情况,优化支护方式(管棚支护、W型钢带及锚索支护等联合支护方式等),确保6号交岔点后续使用期安全。试验结果表明:采用超前控顶加固、控制分区爆破技术,降低破碎软岩巷道顶板偏帮、下沉,保证6号交岔点断面成型效果,削减其支护、后期维护等综合成本达8.7%,该技术可为类似巷道施工提供一定指导建议。 展开更多
关键词 破碎软岩 台阶法施工 支护方式 数码电子雷管
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Dynamic Spatial Discrimination Maps of Discriminative Activation between Different Tasks Based on Support Vector Machines
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作者 Guangxin Huang Huafu Chen Feng Yin 《Applied Mathematics》 2011年第1期85-92,共8页
As a set of supervised pattern recognition methods, support vector machines (SVMs) have been successfully applied to functional magnetic resonance imaging (fMRI) field, but few studies have focused on visualizing disc... As a set of supervised pattern recognition methods, support vector machines (SVMs) have been successfully applied to functional magnetic resonance imaging (fMRI) field, but few studies have focused on visualizing discriminative regions of whole brain between different cognitive tasks dynamically. This paper presents a SVM-based method for visualizing dynamically discriminative activation of whole-brain voxels between two kinds of tasks without any contrast. Our method provides a series of dynamic spatial discrimination maps (DSDMs), representing the temporal evolution of discriminative brain activation during a duty cycle and describing how the discriminating information changes over the duty cycle. The proposed method was applied to investigate discriminative brain functional activations of whole brain voxels dynamically based on a hand-motor task experiment. A set of DSDMs between left hand movement and right hand movement were reached. Our results demonstrated not only where but also when the discriminative activations of whole brain voxels occurred between left hand movement and right hand movement during one duty cycle. 展开更多
关键词 Functional Magnetic RESONANCE Imaging Principal Component Analysis support Vector Machine pattern Recognition Methods Maximum-Margin HYPERPLANE
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Automatic signal detection based on support vector machine
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作者 王海军 刘贵忠 《Acta Seismologica Sinica(English Edition)》 CSCD 2007年第1期88-97,共10页
Algorithm of STA/LTA is frequently used in automatic signal detection, in which the range of detection threshold is (0, ∞), the optimal threshold should be determined by experiment to make a balance between false d... Algorithm of STA/LTA is frequently used in automatic signal detection, in which the range of detection threshold is (0, ∞), the optimal threshold should be determined by experiment to make a balance between false detection and missing detection. By using the theory of pattern recognition, a new algorithm for automatic signal detection based on support vector machine was proposed and the method of preprocess and pattern feature extraction were dis- cussed as well as the selection of kernel function for support vector machine. The detection performance of the new algorithm was analyzed by means of real seismic data. The experiments showed that the new method could simplify the selection of threshold and detect signal accurately. In addition to the better performance of anti-noise, the ratio of false detection could decrease 85% in comparison with that of STA/LTA. 展开更多
关键词 support vector machine EARTHQUAKE automatic processing pattern recognition
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数字平台场域互动观的建构研究 被引量:1
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作者 舒成利 刘芳颖 +1 位作者 赵晶旭 高山行 《华东经济管理》 CSSCI 北大核心 2024年第4期59-71,共13页
文章依据社会学中的场域理论,提出“数字平台场域互动观”。研究发现,数字平台具有“场域”属性,是一种商业场域,场域理论在此具有独到的解释力;互动在数字平台中扮演核心角色,是数字平台运行的微观基础;数字平台的场域互动模式包括同... 文章依据社会学中的场域理论,提出“数字平台场域互动观”。研究发现,数字平台具有“场域”属性,是一种商业场域,场域理论在此具有独到的解释力;互动在数字平台中扮演核心角色,是数字平台运行的微观基础;数字平台的场域互动模式包括同场域互动模式、跨场域互动模式和复跨场域互动模式;数字平台的互动模式决定了其治理机制,并呈现出多样化的特点,从而要求有相对应的保障机制。文章构建了一个平台研究的系统性理论框架,为推动数字平台领域研究、数字平台健康持续发展以及政府有效精准地规制数字平台提供了新思路。 展开更多
关键词 数字平台 场域理论 互动模式 治理机制 保障机制
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Training Robust Support Vector Machine Based on a New Loss Function
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作者 刘叶青 《Journal of Donghua University(English Edition)》 EI CAS 2015年第2期261-263,共3页
To reduce the influences of outliers on support vector machine(SVM) classification problem,a new tangent loss function was constructed.Since the tangent loss function was not smooth in some interval,a smoothing functi... To reduce the influences of outliers on support vector machine(SVM) classification problem,a new tangent loss function was constructed.Since the tangent loss function was not smooth in some interval,a smoothing function was used to approximate it in this interval.According to this loss function,the corresponding tangent SVM(TSVM) was got.The experimental results show that TSVM is less sensitive to outliers than SVM.So the proposed new loss function and TSVM are both effective. 展开更多
关键词 smoothing tangent approximate hinge Training classifier intuitive kernel quadratic retain
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基于黎曼普鲁克的手部离散动作识别方法
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作者 王志恒 沈家和 +1 位作者 都明宇 杨庆华 《高技术通讯》 CAS 北大核心 2024年第8期854-863,共10页
肌电信号能反映人体的运动意图,是外骨骼和假肢控制的主要信号之一。但受试者间的差异,增加了基于表面肌电信号(sEMG)的手部离散动作识别使用成本。针对这一情况,本文从域适应的角度出发,提出一种基于小型调整集的迁移学习建模方法。该... 肌电信号能反映人体的运动意图,是外骨骼和假肢控制的主要信号之一。但受试者间的差异,增加了基于表面肌电信号(sEMG)的手部离散动作识别使用成本。针对这一情况,本文从域适应的角度出发,提出一种基于小型调整集的迁移学习建模方法。该方法利用黎曼普鲁克分析(RPA)提取黎曼特征与传统时域特征作为支持向量机(SVM)的输入特征,并通过实验验证了其识别精度。在10名受试者身上进行了实验,在黎曼特征下黎曼普鲁克分析相比于不进行迁移学习的动作识别方法提高了5%~7%的准确率。在特征空间分布上,黎曼普鲁克分析后的黎曼特征的重合度更高。结果表明,该方法在基于肌电信号的手部离散动作识别上有明显优势。 展开更多
关键词 表面肌电信号(sEMG) 黎曼普鲁克分析(RPA) 手势识别 支持向量机(SVM) 迁移学习
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Optimized Complex Power Quality Classifier Using One vs. Rest Support Vector Machines 被引量:1
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作者 David De Yong Sudipto Bhowmik Fernando Magnago 《Energy and Power Engineering》 2017年第10期568-587,共20页
Nowadays, power quality issues are becoming a significant research topic because of the increasing inclusion of very sensitive devices and considerable renewable energy sources. In general, most of the previous power ... Nowadays, power quality issues are becoming a significant research topic because of the increasing inclusion of very sensitive devices and considerable renewable energy sources. In general, most of the previous power quality classification techniques focused on single power quality events and did not include an optimal feature selection process. This paper presents a classification system that employs Wavelet Transform and the RMS profile to extract the main features of the measured waveforms containing either single or complex disturbances. A data mining process is designed to select the optimal set of features that better describes each disturbance present in the waveform. Support Vector Machine binary classifiers organized in a “One Vs Rest” architecture are individually optimized to classify single and complex disturbances. The parameters that rule the performance of each binary classifier are also individually adjusted using a grid search algorithm that helps them achieve optimal performance. This specialized process significantly improves the total classification accuracy. Several single and complex disturbances were simulated in order to train and test the algorithm. The results show that the classifier is capable of identifying >99% of single disturbances and >97% of complex disturbances. 展开更多
关键词 Complex Power Quality Optimal Feature Selection ONE vs. REST support Vector Machine Learning Algorithms WAVELET Transform pattern Recognition
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Reflections on the Guardianship and Support System of the Elderly Under the Background of an Aging Society
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作者 王丽萍 LI Xiang(译) 《The Journal of Human Rights》 2019年第4期422-436,共15页
China Is aging society poses new challenges to guardianship system in the General Rules of the Civil Law of the People s Republic of China.The General Provisions of the Civil Law adapts to the requirements of the time... China Is aging society poses new challenges to guardianship system in the General Rules of the Civil Law of the People s Republic of China.The General Provisions of the Civil Law adapts to the requirements of the times and makes some important amendments and supplements to the guardianship system,notably the scope of adults with civil disability or limited capacity for civil conduct is no longer limited to people with a mental illness.However,there remain many deficiencies in the regulations.Based on the framework provisions of the existing guardianship system of the General Provisions of Civil Law,in the compilation of the marrage and family provisions in the Civil Code,it is necessary to strengthen the protection of the rights and interests of the elderly in an aging society,further improve the elderly guardianship system,including changing the single pattern of the guardianship system and improving the"dual subject"pattern of adult guardianship and adult support system,expand the scope of protected subject of guardianship,and improve the existing system of intentional custody,adult guardianship system,and guardianship and supervision system. 展开更多
关键词 aging SOCIETY GUARDIANSHIP SYSTEM ADULT GUARDIANSHIP support SYSTEM "dual subject"protection pattern
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四边固支板在均布荷载作用下的剪力分布规律
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作者 只红茹 尹涛 任增金 《水运工程》 2024年第4期33-36,55,共5页
沉箱底板抗剪往往需要控制底板厚度,而现有剪力分布规律研究较少,针对此问题采用有限元方法进行不同组合工况的计算,研究四边固支板在均布荷载作用下,板边最大剪力分布以及最大剪力随板厚、边长、长宽比的变化关系,得出最大剪力与平均... 沉箱底板抗剪往往需要控制底板厚度,而现有剪力分布规律研究较少,针对此问题采用有限元方法进行不同组合工况的计算,研究四边固支板在均布荷载作用下,板边最大剪力分布以及最大剪力随板厚、边长、长宽比的变化关系,得出最大剪力与平均剪力之比的一般规律。研究结果表明:板边剪力分布呈类抛物线形,板边最大剪力值小于弹性薄板理论计算的最大剪力值;相同尺度和荷载情况下,矩形板厚度增大其板边最大剪力值将有所减小;矩形板尺度增大,板边最大剪力值将迅速增大且最大剪力与平均剪力之比也有所增大;对于常用沉箱纵横隔墙间距和底板厚度,板边最大剪力与平均剪力之比通常为1.3~1.6。总结剪力分布与仓格尺度的关系,旨在为类似工程设计提供参考。 展开更多
关键词 四边固支板 剪力 分布规律 有限元
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留守经历、情感模式与互助型夫妻关系实践——留守经历的叙述与意义阐释
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作者 佟新 《山东女子学院学报》 2024年第1期13-25,共13页
研究通过对三位有过留守经历的女性叙述,理解其留守经历对她们情感生活的意义。研究发现,童年和奶奶的共同生活使她们记忆的是“有奶奶的家”,和奶奶一起生活,让她们学会了独立和能吃苦的精神。成长后的她们以独立身份经营自己的情感、... 研究通过对三位有过留守经历的女性叙述,理解其留守经历对她们情感生活的意义。研究发现,童年和奶奶的共同生活使她们记忆的是“有奶奶的家”,和奶奶一起生活,让她们学会了独立和能吃苦的精神。成长后的她们以独立身份经营自己的情感、生育与夫妻关系,大致形塑了三类情感模式:一类是以愤怒为基础的敏感和自尊式情感类型;一类是以艰苦勤劳为底色的自信和自主式情感类型;一类是以需求被满足为基础的自爱和学习型情感类型。新生代女性是我国欠发达地区的职业教育和新型城镇化发展的受惠者,她们抓住机会,掌握自己的命运,成为摆脱父权制和母亲命运的创造者、新型城镇化过程中互助型夫妻关系的主导者。 展开更多
关键词 留守经历 奶奶在的家 情感模式 主体性 互助型夫妻关系
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隧道斜向超前系统锚杆支护效果及承载规律
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作者 杜佳敏 何川 +3 位作者 汪波 徐国文 陈旭 徐昆杰 《隧道建设(中英文)》 CSCD 北大核心 2024年第8期1617-1631,共15页
为研究渝昆高铁斜向超前系统锚杆支护体系的力学特性,在乐业隧道开展了斜向超前系统锚杆现场试验,结合有限差分数值模拟,基于支护应力场的概念,实现斜向超前系统锚杆有效支护范围的定量描述,采用多指标(隧道位移差、围岩塑性区、围岩最... 为研究渝昆高铁斜向超前系统锚杆支护体系的力学特性,在乐业隧道开展了斜向超前系统锚杆现场试验,结合有限差分数值模拟,基于支护应力场的概念,实现斜向超前系统锚杆有效支护范围的定量描述,采用多指标(隧道位移差、围岩塑性区、围岩最小主应力)对斜向超前系统锚杆的支护效果进行定量评价。通过分析锚杆轴力、钢拱架轴力的分布特征,确定斜向超前支护体系的承载规律,并与现场试验结果进行验证和对比分析。结果表明:1)隧道开挖后,锚杆支护会形成支护应力场,即在开挖面附近形成了最大主应力增大区,而最大主应力的增大提高了岩体抵抗变形的能力;2)随着掌子面空间效应的减弱,斜向锚杆需要承担的围岩荷载逐渐增大,其有效支护的范围也逐渐增大;3)在掌子面附近,斜向锚杆支护提高了围岩的自承载能力,降低了拱顶、拱肩和拱腰处钢拱架的轴力,改善了钢拱架的受力特征。 展开更多
关键词 隧道 斜向超前系统锚杆 支护应力场 有效支护范围 支护效果 支护体系承载规律
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脑卒中病人夫妻沟通模式现状及影响因素 被引量:1
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作者 刘志薇 梅永霞 +5 位作者 张振香 林蓓蕾 陈素艳 刘晓 李昕 袁燕 《护理研究》 北大核心 2024年第7期1182-1189,共8页
目的:调查脑卒中病人夫妻沟通模式现状,并分析其影响因素。方法:采用便利抽样法,于2022年10月—2023年4月选取河南省某6所三级甲等医院神经内科的381例脑卒中病人为调查对象。采用一般资料调查表、改良版Rankin量表、中文版家庭韧性问... 目的:调查脑卒中病人夫妻沟通模式现状,并分析其影响因素。方法:采用便利抽样法,于2022年10月—2023年4月选取河南省某6所三级甲等医院神经内科的381例脑卒中病人为调查对象。采用一般资料调查表、改良版Rankin量表、中文版家庭韧性问卷、领悟社会支持量表、亲密关系满意度量表和沟通模式问卷进行调查。采用多元线性回归分析沟通模式的影响因素。结果:脑卒中病人的建设性沟通得分为(10.74±8.69)分,要求/回避沟通得分为(17.83±9.07)分,双方回避沟通得分为(8.64±4.85)分。多元线性回归分析结果显示,病人的性别、家庭人均月收入、患病后工作情况、病程、脑卒中次数、合并症数量、有无语言功能障碍、对自己病情了解程度、家庭韧性、领悟社会支持和亲密关系满意度是沟通模式的影响因素(P<0.05)。结论:脑卒中病人的建设性沟通有待提高,医护人员应根据沟通模式的影响因素制定针对性的干预措施,以帮助脑卒中病人夫妻积极应对疾病,改善其沟通模式,从而减轻其负性情绪。 展开更多
关键词 脑卒中 夫妻沟通模式 家庭韧性 社会支持 亲密关系 影响因素
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Progressive transductive learning pattern classification via single sphere
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作者 Xue Zhenxia Liu Sanyang Liu Wanli 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第3期643-650,共8页
In many machine learning problems, a large amount of data is available but only a few of them can be labeled easily. This provides a research branch to effectively combine unlabeled and labeled data to infer the label... In many machine learning problems, a large amount of data is available but only a few of them can be labeled easily. This provides a research branch to effectively combine unlabeled and labeled data to infer the labels of unlabeled ones, that is, to develop transductive learning. In this article, based on Pattern classification via single sphere (SSPC), which seeks a hypersphere to separate data with the maximum separation ratio, a progressive transductive pattern classification method via single sphere (PTSSPC) is proposed to construct the classifier using both the labeled and unlabeled data. PTSSPC utilize the additional information of the unlabeled samples and obtain better classification performance than SSPC when insufficient labeled data information is available. Experiment results show the algorithm can yields better performance. 展开更多
关键词 pattern recognition semi-supervised learning transductive learning CLASSIFICATION support vector machine support vector domain description.
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单向阀微弱内泄漏故障征提取与模式识别研究
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作者 熊力 刘宁 +1 位作者 童成彪 程军圣 《机械科学与技术》 CSCD 北大核心 2024年第5期756-764,共9页
单向阀被广泛应用于工程机械、农业机械、军事车辆液压系统中,泄漏是单向阀的常见故障。本文提出了一种基于时频分解的多源多域、多尺度特征提取与机器学习的单向阀微弱内泄漏故障诊断方法。对4类微弱内泄漏故障的振动信号和压力信号进... 单向阀被广泛应用于工程机械、农业机械、军事车辆液压系统中,泄漏是单向阀的常见故障。本文提出了一种基于时频分解的多源多域、多尺度特征提取与机器学习的单向阀微弱内泄漏故障诊断方法。对4类微弱内泄漏故障的振动信号和压力信号进行经验模态分解;采用时域、频域以及时频域的奇异值、波形因子、熵值等方法进行特征提取并构造故障特征向量;基于粒子群-支持向量机进行单向阀内泄漏故障模式识别。实验结果表明该方法能有效地检测单向阀内泄漏,模式识别准确率达到90%以上。本文为单向阀内泄漏量预测研究奠定了基础,具有较好的工程应用前景。 展开更多
关键词 单向阀 内泄漏 经验模态分解 支持向量机 模式识别
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