基于语音心理声学分析的驾驶疲劳检测EI北大核心CSCD

针对现有方法在分析角度和特征参数上的局限性,提出一种基于语音心理声学分析的驾驶疲劳检测方法。首先,借助心理声学感知掩蔽处理步骤,将语音中的疲劳高敏感性频率成分突显出来,并给予其更多的Bark域临界频带描述,以获得更为细致的疲劳信息表达;其次,提取多种心理声学感知特征来量化描述语音中的疲劳异常音,并针对语音波形不同步而导致的特征提取误差问题,给出了语音帧的快速对准方案;最后,将语音样本与多个参考样本对比分析所得的感知特征向量,来分别搭建多个特征层模糊支持向量机（FSVM）分类器,并通过动态贝叶斯网络（DBN）的决策层融合判决,实现更为准确、鲁棒的驾驶疲劳检测。实验结果表明,该方法的查准率、查全率和平均正确率（为92.4%）均优于现有方法,尤其对重度疲劳的检测效果较佳（正确率达96.1%）。     

基于语音心理声学分析的驾驶疲劳检测

针对现有方法在分析角度和特征参数上的局限性,提出一种基于语音心理声学分析的驾驶疲劳检测方法。首先,借助心理声学感知掩蔽处理步骤,将语音中的疲劳高敏感性频率成分突显出来,并给予其更多的Bark域临界频带描述,以获得更为细致的疲劳信息表达;其次,提取多种心理声学感知特征来量化描述语音中的疲劳异常音,并针对语音波形不同步而导致的特征提取误差问题,给出了语音帧的快速对准方案;最后,将语音样本与多个参考样本对比分析所得的感知特征向量,来分别搭建多个特征层模糊支持向量机(FSVM)分类器,并通过动态贝叶斯网络(DBN)的决策层融合判决,实现更为准确、鲁棒的驾驶疲劳检测。实验结果表明,该方法的查准率、查全率和平均正确率(为92.4%)均优于现有方法,尤其对重度疲劳的检测效果较佳(正确率达96.1%)。     

基于多生理信息及迁移学习的驾驶疲劳评估EI北大核心CSCD

目前基于多生理信号的驾驶疲劳评估方法得到广泛关注。针对驾驶疲劳识别率有待提高且受个体差异性影响的问题,提出了基于脑电、心电和肌电特征融合及迁移学习的驾驶疲劳评估方法。基于模拟驾驶平台同步采集20名健康受试者的脑电信号、心电信号和颈部肌电信号,基于时频分析方法和复杂度分析方法提取各生理信号特征并进行融合;然后,基于特征空间内大间隔映射（LMPROJ）的迁移学习方法实现对单一源域到目标域疲劳状态的初步判别;最后,将上述多个单一源域到目标域疲劳状态的判别结果进行决策级融合,以提高驾驶疲劳识别算法的准确性和鲁棒性。实验结果表明,基于多生理信号特征融合及迁移学习的驾驶疲劳识别率高于传统机器学习方法,且能提高不同受试者驾驶疲劳检测的鲁棒性,为多生理信号驾驶疲劳检测研究提供了新方法。     

多特征融合的驾驶员疲劳检测研究

针对驾驶疲劳检测中面部特征定位及驾驶员疲劳状态判别方法判断存在的不足,提出了利用监督下降算法同时定位驾驶员的多个面部特征。在眨眼、哈欠及点头判断的基础上,提取驾驶员眨眼频率、哈欠频率及点头频率多个特征值建立疲劳检测样本数据库,并构建朴素贝叶斯分类器进行疲劳判断。当驾驶员出现疲劳驾驶时及时给以警告信息,以预防交通事故发生。在实际的驾驶环境视频测试结果中,驾驶员疲劳状态的判别平均准确率达到了94.87%,具有较好的性能。     

基于多生理信息及迁移学习的驾驶疲劳评估

目前基于多生理信号的驾驶疲劳评估方法得到广泛关注。针对驾驶疲劳识别率有待提高且受个体差异性影响的问题,提出了基于脑电、心电和肌电特征融合及迁移学习的驾驶疲劳评估方法。基于模拟驾驶平台同步采集20名健康受试者的脑电信号、心电信号和颈部肌电信号,基于时频分析方法和复杂度分析方法提取各生理信号特征并进行融合;然后,基于特征空间内大间隔映射(LMPROJ)的迁移学习方法实现对单一源域到目标域疲劳状态的初步判别;最后,将上述多个单一源域到目标域疲劳状态的判别结果进行决策级融合,以提高驾驶疲劳识别算法的准确性和鲁棒性。实验结果表明,基于多生理信号特征融合及迁移学习的驾驶疲劳识别率高于传统机器学习方法,且能提高不同受试者驾驶疲劳检测的鲁棒性,为多生理信号驾驶疲劳检测研究提供了新方法。     

基于面部识别的驾驶员疲劳危险驾驶检测系统

为了有效降低驾驶员疲劳驾驶、短时间未看道路等危险驾驶的概率,设计了以面部特征为研究对象的人脸识别的检测系统.该系统通过对面部识别以及眼睛和嘴的定位跟踪,提取面部疲劳信息,将跟踪的图像信息传输到OpenCV视觉库进行图像处理,通过一系列的算法对驾驶员疲劳、危险驾驶行为进行判断、疲劳值计算,最后通过安全警报模块对驾驶员给予警报提示.经实验测试,该系统满足车载、实时性、准确性的要求,能够快速的检测驾驶员的危险驾驶状态,具有一定的实用性.     

融合面部特征的机动车驾驶人疲劳检测

为降低因驾驶人疲劳驾驶导致的交通事故,需要开展驾驶人疲劳检测研究.为满足在线实时检测的要求,本文提出了融合面部特征的机动车驾驶人疲劳检测方法,首先通过背景差分缩小检测区域、减少图像金字塔层数等方法对MTCNN人脸检测网络进行优化加速,加速后的速度与之前相比提升了258％.其次通过多级级联的残差回归树对人脸进行特征点检测,得到了人脸的特征点,最后通过融合面部嘴、眼开合度特征的方式建立驾驶人疲劳检测模型并进行训练.实验表明,该检测方法的准确率可达95.4％,每帧检测平均速度64 ms,检测速度快,能满足实时性的要求.     

融合面部特征的机动车驾驶人疲劳检测

为降低因驾驶人疲劳驾驶导致的交通事故,需要开展驾驶人疲劳检测研究.为满足在线实时检测的要求,本文提出了融合面部特征的机动车驾驶人疲劳检测方法,首先通过背景差分缩小检测区域、减少图像金字塔层数等方法对MTCNN人脸检测网络进行优化加速,加速后的速度与之前相比提升了258％.其次通过多级级联的残差回归树对人脸进行特征点检测,得到了人脸的特征点,最后通过融合面部嘴、眼开合度特征的方式建立驾驶人疲劳检测模型并进行训练.实验表明,该检测方法的准确率可达95.4％,每帧检测平均速度64 ms,检测速度快,能满足实时性的要求.     

非线性超声检测镁合金疲劳的仿真和试验

为了利用非线性超声检测AZ31镁合金的早期疲劳损伤,通过现有的本构关系建立了非线性超声检测有限元模型,计算了材料疲劳引起的内部微缺陷长度、数量和宽度变化对非线性超声系数的影响.计算结果表明,材料疲劳产生的微缺陷是产生二次谐波的原因,有限元方法可以有效模拟镁合金材料的超声非线性效应.进行了两个镁合金疲劳试件的非线性超声在线检测试验,研究发现,在镁合金疲劳早期,超声非线性系数随疲劳加载周数单调增加,但在疲劳后期出现了超声非线性系数减小的现象.试验结果表明,超声非线性系数对疲劳早期损伤非常敏感,可以用来表征材料的早期疲劳损伤程度,有限元计算结果与试验结果相吻合.     

驾驶员疲劳检测实时控制系统设计

为了实现对驾驶员疲劳状态的在线监测,建立了驾驶员疲劳检测实时控制系统。对该系统所采用的人脸识别、人脸跟踪技术、人眼定位以及疲劳状态判断等进行研究。首先,介绍了系统的构成,以模块化思想构建系统软件。接着,以MB-LBP算法对人脸进行特征分类,结合Adaboost级联算法提取人脸信息,并与经典的人脸识别算法进行了对比。然后,利用人脸跟踪技术提高人脸识别的效率,并成功地实现了人眼定位于检测。最后,使用椭圆拟合算法对检测出来的眼睛区域进行拟合,通过计算驾驶员单次眨眼时间,进行驾驶员疲劳状态判别。试验结果表明:所设计的基于驾驶员面部特征的驾驶员疲劳驾驶检测系统,能够有效地检测驾驶员的疲劳状态,平均正确检测率高于90%。基本满足驾驶员疲劳驾驶非接触检测实时性好、准确性高的要求。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.