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Rail Surface Defect Detection Based on Improved UPerNet and Connected Component Analysis
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作者 Yongzhi Min Jiafeng Li Yaxing Li 《Computers, Materials & Continua》 SCIE EI 2023年第10期941-962,共22页
To guarantee the safety of railway operations,the swift detection of rail surface defects becomes imperative.Traditional methods of manual inspection and conventional nondestructive testing prove inefficient,especiall... To guarantee the safety of railway operations,the swift detection of rail surface defects becomes imperative.Traditional methods of manual inspection and conventional nondestructive testing prove inefficient,especially when scaling to extensive railway networks.Moreover,the unpredictable and intricate nature of defect edge shapes further complicates detection efforts.Addressing these challenges,this paper introduces an enhanced Unified Perceptual Parsing for Scene Understanding Network(UPerNet)tailored for rail surface defect detection.Notably,the Swin Transformer Tiny version(Swin-T)network,underpinned by the Transformer architecture,is employed for adept feature extraction.This approach capitalizes on the global information present in the image and sidesteps the issue of inductive preference.The model’s efficiency is further amplified by the windowbased self-attention,which minimizes the model’s parameter count.We implement the cross-GPU synchronized batch normalization(SyncBN)for gradient optimization and integrate the Lovász-hinge loss function to leverage pixel dependency relationships.Experimental evaluations underscore the efficacy of our improved UPerNet,with results demonstrating Pixel Accuracy(PA)scores of 91.39%and 93.35%,Intersection over Union(IoU)values of 83.69%and 87.58%,Dice Coefficients of 91.12%and 93.38%,and Precision metrics of 90.85%and 93.41%across two distinct datasets.An increment in detection accuracy was discernible.For further practical applicability,we deploy semantic segmentation of rail surface defects,leveraging connected component processing techniques to distinguish varied defects within the same frame.By computing the actual defect length and area,our deep learning methodology presents results that offer intuitive insights for railway maintenance professionals. 展开更多
关键词 Rail surface defects connected component analysis TRANSFORMER UPerNet
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Application of a Fast Connected Components Labeling Algorithm in Processing Landmark Images 被引量:2
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作者 闫士举 王成焘 +2 位作者 陈统一 袁文 苏颖颖 《Journal of Shanghai Jiaotong university(Science)》 EI 2007年第3期383-387,393,共6页
Extracting geometric data of landmarks from fluoroscopic images plays an important role in camera calibration process of a fluoroscopic-image-based surgical navigation system. Connected components labeling is the esse... Extracting geometric data of landmarks from fluoroscopic images plays an important role in camera calibration process of a fluoroscopic-image-based surgical navigation system. Connected components labeling is the essential technique for the extraction. A new fast connected components labeling algorithm was presented. The definition of upward concave set was introduced to explain the algorithm. Feasibility and efficiency of the algorithm were verified with experiments. This algorithm performs well in labeling non-upward concave set connected components and applies to landmarks labeling well. Moreover, the proposed algorithm possesses a desirable characteristic that will facilitate the subsequent processing of fluoroscopic images. 展开更多
关键词 C-ARM surgical navigation system connected components labeling convex set
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A fast connected components labeling algorithm for binary images 被引量:1
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作者 付宜利 韩现伟 王树国 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2012年第3期81-87,共7页
A fast label-equivalence-based connected components labeling algorithm is proposed in this paper.It is a combination of two existing efficient methods,which are pivotal operations in two-pass connected components labe... A fast label-equivalence-based connected components labeling algorithm is proposed in this paper.It is a combination of two existing efficient methods,which are pivotal operations in two-pass connected components labeling algorithms.One is a fast pixel scan method,and the other is an array-based Union-Find data structure.The scan procedure assigns each foreground pixel a provisional label according to the location of the pixel.That is to say,it labels the foreground pixels following background pixels and foreground pixels in different ways,which greatly reduces the number of neighbor pixel checks.The array-based Union-Find data structure resolves the label equivalences between provisional labels by using only a single array with path compression,and it improves the efficiency of the resolving procedure which is very time-consuming in general label-equivalence-based algorithms.The experiments on various types of images with different sizes show that the proposed algorithm is superior to other labeling approaches for huge images containing many big connected components. 展开更多
关键词 binary image connected components labeling algorithm Union-Find label-equivalence
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On the numbers of connected components of hattorigraph 被引量:3
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作者 Chen Guiyun(Department of Mathematics Southwest China Normal University, Chongqing 630715) 《西南师范大学学报(自然科学版)》 CAS CSCD 1995年第4期345-347,共3页
OnthenumbersofconnectedcomponentsofhattorigraphChenGuiyun(DepartmentofMathematicsSouthwestChinaNormalUnivers... OnthenumbersofconnectedcomponentsofhattorigraphChenGuiyun(DepartmentofMathematicsSouthwestChinaNormalUniversity,Chongqing6307... 展开更多
关键词 Hattori图 连通分支数
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A Study of Method on Connectivity Analysis of Between Software Components
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作者 Hu Feng, Lin Zi yu , Pen De chun State Key Laboratory of Software Engineering, Wuhan University, Wuhan 430072, China 《Wuhan University Journal of Natural Sciences》 CAS 2001年第Z1期288-291,共4页
An analysis and computation method of connectivity between components that based on logical subtyping is first presented, the concepts of virtual interface and real interface, and quantitative analysis and computation... An analysis and computation method of connectivity between components that based on logical subtyping is first presented, the concepts of virtual interface and real interface, and quantitative analysis and computation formula of connectivity between interfaces are also introduced, that based on a extendable software architecture specification language model. We provide a new idea for solving the problem of connection between reuse components. 展开更多
关键词 connectivity analysis component interface logical subtyping
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On the growth of transcendental entire functions with multiply connected components
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作者 伍家凤 徐光伟 王小灵 《Journal of Shanghai University(English Edition)》 CAS 2007年第1期45-48,共4页
Let g and h be two transcendental entire functions. Suppose that the Fatou set F(goh) contains multiply connected components. In this article, we will consider the growth of the functions g and h.
关键词 multiply connected component Fatou set GROWTH
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Structural Analysis and Design of Steel Connections Using Component-Based Finite Element Model
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作者 Lubomir Sabatka Frantisek Wald +2 位作者 Jaromir Kabelac Drahoslav Kolaja Martin Pospisil 《Journal of Civil Engineering and Architecture》 2015年第8期895-901,共7页
This paper introduces CBFEM (component-based finite element model) which is a new method to analyze and design connections of steel structures. Design focused CM (component model) is compared to FEM (finite eleme... This paper introduces CBFEM (component-based finite element model) which is a new method to analyze and design connections of steel structures. Design focused CM (component model) is compared to FEM (finite elements models). Procedure for composition of a model based on usual production process is used in CBFEM. Its results are compared to those obtained by component method for portal frame eaves moment connection with good agreement. Design of moment resistant column base is demonstrated by a case loaded by two directional bending moments and normal force. Interaction of several connections in one complex joint is explained in the last example. This paper aims to provide structural engineers with a new tool to effectively analyze and design various joints of steel structures. 展开更多
关键词 Steel structures structural connections finite element model component model analytical model design model.
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The g-Component Connectivity of Some Networks
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作者 Ganghua Xie Yinkui Li 《Open Journal of Applied Sciences》 2023年第12期2421-2430,共10页
In 2012, Hsu et al. generalized the classical connectivity of graph G and introduced the concept of g-component connectivity CK<sub>g</sub> (G) to measure the fault tolerance of networks. In this pape... In 2012, Hsu et al. generalized the classical connectivity of graph G and introduced the concept of g-component connectivity CK<sub>g</sub> (G) to measure the fault tolerance of networks. In this paper, we determine the g-component connectivity of some graphs, such as fan graph, helm graph, crown graph, Gear graph and the Mycielskian graph of star graph and complete bipartite graph. 展开更多
关键词 g-component connectivity Mycielskian Graph The Fault Tolerance of Networks
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Altered intra- and inter-network brain functional connectivity in upper-limb amputees revealed through independent component analysis 被引量:2
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作者 Bing-Bo Bao Hong-Yi Zhu +6 位作者 Hai-Feng Wei Jing Li Zhi-Bin Wang Yue-Hua Li Xu-Yun Hua Mou-Xiong Zheng Xian-You Zheng 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第12期2725-2729,共5页
Although cerebral neuroplasticity following amputation has been observed, little is understood about how network-level functional reorganization occurs in the brain following upper-limb amputation. The objective of th... Although cerebral neuroplasticity following amputation has been observed, little is understood about how network-level functional reorganization occurs in the brain following upper-limb amputation. The objective of this study was to analyze alterations in brain network functional connectivity(FC) in upper-limb amputees(ULAs). This observational study included 40 ULAs and 40 healthy control subjects;all participants underwent resting-state functional magnetic resonance imaging. Changes in intra-and inter-network FC in ULAs were quantified using independent component analysis and brain network FC analysis. We also analyzed the correlation between FC and clinical manifestations, such as pain. We identified 11 independent components using independent component analysis from all subjects. In ULAs, intra-network FC was decreased in the left precuneus(precuneus gyrus) within the dorsal attention network and left precentral(precentral gyrus) within the auditory network;but increased in the left Parietal_Inf(inferior parietal, but supramarginal and angular gyri) within the ventral sensorimotor network, right Cerebelum_Crus2(crus Ⅱ of cerebellum) and left Temporal_Mid(middle temporal gyrus) within the ventral attention network, and left Rolandic_Oper(rolandic operculum) within the auditory network. ULAs also showed decreased inter-network FCs between the dorsal sensorimotor network and ventral sensorimotor network, the dorsal sensorimotor network and right frontoparietal network, and the dorsal sensorimotor network and dorsal attention network. Correlation analyses revealed negative correlations between inter-network FC changes and residual limb pain and phantom limb pain scores, but positive correlations between inter-network FC changes and daily activity hours of stump limb. These results show that post-amputation plasticity in ULAs is not restricted to local remapping;rather, it also occurs at a network level across several cortical regions. This observation provides additional insights into the plasticity of brain networks after upper-limb amputation, and could contribute to identification of the mechanisms underlying post-amputation pain. 展开更多
关键词 AMPUTATION functional connectivity functional magnetic resonance imaging independent component analysis NEUROIMAGING phantom pain phantom sensation resting-state networks
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Robust Virtual Network Embedding Based on Component Connectivity in Large-Scale Network 被引量:4
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作者 Xiaojuan Wang Mei Song +1 位作者 Deyu Yuan Xiangru Liu 《China Communications》 SCIE CSCD 2017年第10期164-179,共16页
Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuris... Virtual network embedding problem which is NP-hard is a key issue for implementing software-defined network which is brought about by network virtualization. Compared with other studies which focus on designing heuristic algorithms to reduce the hardness of the NP-hard problem we propose a robust VNE algorithm based on component connectivity in large-scale network. We distinguish the different components and embed VN requests onto them respectively. And k-core is applied to identify different VN topologies so that the VN request can be embedded onto its corresponding component. On the other hand, load balancing is also considered in this paper. It could avoid blocked or bottlenecked area of substrate network. Simulation experiments show that compared with other algorithms in large-scale network, acceptance ratio, average revenue and robustness can be obviously improved by our algorithm and average cost can be reduced. It also shows the relationship between the component connectivity including giant component and small components and the performance metrics. 展开更多
关键词 large-scale network component connectivity virtual network embedding SDN
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Unsupervised Segmentation Method of Multicomponent Images based on Fuzzy Connectivity Analysis in the Multidimensional Histograms 被引量:2
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作者 Sié Ouattara Georges Laussane Loum Alain Clément 《Engineering(科研)》 2011年第3期203-214,共12页
Image segmentation denotes a process for partitioning an image into distinct regions, it plays an important role in interpretation and decision making. A large variety of segmentation methods has been developed;among ... Image segmentation denotes a process for partitioning an image into distinct regions, it plays an important role in interpretation and decision making. A large variety of segmentation methods has been developed;among them, multidimensional histogram methods have been investigated but their implementation stays difficult due to the big size of histograms. We present an original method for segmenting n-D (where n is the number of components in image) images or multidimensional images in an unsupervised way using a fuzzy neighbourhood model. It is based on the hierarchical analysis of full n-D compact histograms integrating a fuzzy connected components labelling algorithm that we have realized in this work. Each peak of the histo- gram constitutes a class kernel, as soon as it encloses a number of pixels greater than or equal to a secondary arbitrary threshold knowing that a first threshold was set to define the degree of binary fuzzy similarity be- tween pixels. The use of a lossless compact n-D histogram allows a drastic reduction of the memory space necessary for coding it. As a consequence, the segmentation can be achieved without reducing the colors population of images in the classification step. It is shown that using n-D compact histograms, instead of 1-D and 2-D ones, leads to better segmentation results. Various images were segmented;the evaluation of the quality of segmentation in supervised and unsupervised of segmentation method proposed compare to the classification method k-means gives better results. It thus highlights the relevance of our approach, which can be used for solving many problems of segmentation. 展开更多
关键词 MULTIcomponENT IMAGES Unsupervised SEGMENTATION n-D HISTOGRAM FUZZY connected components Labelling n-D Compact HISTOGRAM Evaluation of SEGMENTATION Quality
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New Algorithm for Binary Connected-Component Labeling Based on Run-Length Encoding and Union-Find Sets 被引量:3
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作者 王洪涛 罗长洲 +2 位作者 王渝 郭贺 赵述芳 《Journal of Beijing Institute of Technology》 EI CAS 2010年第1期71-75,共5页
Based on detailed analysis of advantages and disadvantages of the existing connected-component labeling (CCL) algorithm,a new algorithm for binary connected components labeling based on run-length encoding (RLE) a... Based on detailed analysis of advantages and disadvantages of the existing connected-component labeling (CCL) algorithm,a new algorithm for binary connected components labeling based on run-length encoding (RLE) and union-find sets has been put forward.The new algorithm uses RLE as the basic processing unit,converts the label merging of connected RLE into sets grouping in accordance with equivalence relation,and uses the union-find sets which is the realization method of sets grouping to solve the label merging of connected RLE.And the label merging procedure has been optimized:the union operation has been modified by adding the "weighted rule" to avoid getting a degenerated-tree,and the "path compression" has been adopted when implementing the find operation,then the time complexity of label merging is O(nα(n)).The experiments show that the new algorithm can label the connected components of any shapes very quickly and exactly,save more memory,and facilitate the subsequent image analysis. 展开更多
关键词 binary images connected-component labeling run-length encoding union-find sets
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Real Time Speed Bump Detection Using Gaussian Filtering and Connected Component Approach 被引量:1
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作者 W. Devapriya C. Nelson Kennedy Babu T. Srihari 《Circuits and Systems》 2016年第9期2168-2175,共8页
An Intelligent Transportation System (ITS) is a new system developed for the betterment of user in traffic and transport management domain area for smart and safe driving. ITS subsystems are Emergency vehicle notifica... An Intelligent Transportation System (ITS) is a new system developed for the betterment of user in traffic and transport management domain area for smart and safe driving. ITS subsystems are Emergency vehicle notification systems, Automatic road enforcement, Collision avoidance systems, Automatic parking, Map database management, etc. Advance Driver Assists System (ADAS) belongs to ITS which provides alert or warning or information to the user during driving. The proposed method uses Gaussian filtering and Median filtering to remove noise in the image. Subsequently image subtraction is achieved by subtracting Median filtered image from Gaussian filtered image. The resultant image is converted to binary image and the regions are analyzed using connected component approach. The prior work on speed bump detection is achieved using sensors which are failed to detect speed bumps that are constructed with small height and the detection rate is affected due to erroneous identification. And the smartphone and accelerometer methodologies are not perfectly suitable for real time scenario due to GPS error, network overload, real-time delay, accuracy and battery running out. The proposed system goes very well for the roads which are constructed with proper painting irrespective of their dimension. 展开更多
关键词 Intelligent Transportation System Speed Bumps Driver Assistance System Gaussian and Median Filtering connected component Analysis
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Survivability of Components Assembly in Architecture
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作者 GUO Wei ZHENG Yanyan XU Renzuo 《Wuhan University Journal of Natural Sciences》 CAS 2008年第5期533-538,共6页
Based on the in-depth analysis of the interaction patterns between the components of software system in architecture, this paper illustrates that the association among them is complex and usually changeable during the... Based on the in-depth analysis of the interaction patterns between the components of software system in architecture, this paper illustrates that the association among them is complex and usually changeable during the running period. So we assume the interactions between two adjacency components are grouped into a single connector, which can be used to analyze the influence of components assembly on the survivability for software architecture. The survivability of the components assembly is mapped into the connectivity of graph model. We also bring forward a simplicity method to calculate and quantify the survivability of architecture that could provide a more usable model for designers to evaluate the architecture. 展开更多
关键词 SURVIVABILITY software architecture component-based software graph connectivity
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基于电成像的孔洞型碳酸盐岩储层连通性评价 被引量:1
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作者 孙建孟 程耀东 +2 位作者 何娟 刘璋 陈培元 《测井技术》 CAS 2024年第1期75-83,116,共10页
碳酸盐岩储层非均质性强,孔隙结构复杂,相较于常规碎屑岩储层,其孔隙度、渗透率关系的规律及特征不明显。碳酸盐岩储层的连通性与孔洞特征具有强相关性,且连通性是影响储层渗透率的重要因素,因此,对碳酸盐岩孔洞连通性的评价是孔洞型碳... 碳酸盐岩储层非均质性强,孔隙结构复杂,相较于常规碎屑岩储层,其孔隙度、渗透率关系的规律及特征不明显。碳酸盐岩储层的连通性与孔洞特征具有强相关性,且连通性是影响储层渗透率的重要因素,因此,对碳酸盐岩孔洞连通性的评价是孔洞型碳酸盐岩储层评价的关键问题。以伊拉克东南部B油田FQ-1井M组MB21亚油组孔洞型碳酸盐岩储层为例,基于地层微电阻率扫描成像(FMI)测井的高分辨率动态图像,利用最大类间方差算法(OTSU)进行二次迭代分割,识别电成像图像孔洞;根据8连通域标记法标记连通孔洞;提取每个连通孔洞的特征孔径、内部最长通道距离、内部最长通道与水平方向夹角、平均通道宽度这4个几何参数,最终构建孔洞型碳酸盐岩储层连通指数。连通指数在伊拉克东南部B油田FQ-1井M组MB21亚油组孔洞型碳酸盐岩储层的应用表明,利用此方法建立的连通指数与FQ-1井碳酸盐岩储层岩心渗透率相关系数达0.8437,并且连通指数曲线的趋势符合岩心渗透率在储层不同深度的分布情况,证明了连通指数可以指示储层孔隙结构较好、溶蚀孔洞发育的深度段,并可以划分储层中连通性较好的深度区间,该参数对于寻找碳酸盐岩储层渗透层具有重要意义。 展开更多
关键词 孔洞型碳酸盐岩 连通指数 电成像测井 孔洞识别 连通域标记
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基于多层全连接神经网络的6C地震波极化向量识别研究
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作者 廖成旺 庞聪 +1 位作者 江勇 吴涛 《大地测量与地球动力学》 CSCD 北大核心 2024年第4期331-335,435,共6页
利用机器学习原理,提出一种基于多层全连接(multi-layer fully connected, MFC)神经网络的六分量(six-component, 6C)地震波极化向量识别方法。首先利用6C地震波各波型极化向量数学模型和一系列仿真参数得到5种波型和噪声波型各5 000个... 利用机器学习原理,提出一种基于多层全连接(multi-layer fully connected, MFC)神经网络的六分量(six-component, 6C)地震波极化向量识别方法。首先利用6C地震波各波型极化向量数学模型和一系列仿真参数得到5种波型和噪声波型各5 000个极化向量数据集,然后随机选取其中5 000个作为测试集,其余划分为训练集,进行MFC神经网络与支持向量机(support vector machine, SVM)的综合辨识性能对比实验。结果表明,MFC神经网络模型识别5种极化向量类型(SH波和Love波视为一类)和6种极化向量类型的效果均显著优于SVM模型,平均识别率分别达到99.786%和87.940%。 展开更多
关键词 极化向量识别 六分量地震波 多层全连接神经网络 支持向量机
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基于改进连通域检测算法的电力工程图纸识别技术
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作者 樊冬梅 严文豆 +1 位作者 梁毅 刘巍巍 《沈阳工业大学学报》 CAS 北大核心 2024年第4期361-366,共6页
针对电力工程图纸识别中存在无法整体标记粘连字符以及标记效率较低的问题,提出了基于数学形态膨胀处理及简化决策树的连通域标记算法。利用可灵活设定的结构元素对输入图像进行膨胀处理,实现了对粘连字符的整体标记;通过分析相邻像素... 针对电力工程图纸识别中存在无法整体标记粘连字符以及标记效率较低的问题,提出了基于数学形态膨胀处理及简化决策树的连通域标记算法。利用可灵活设定的结构元素对输入图像进行膨胀处理,实现了对粘连字符的整体标记;通过分析相邻像素的各种可能性,设计了一种基于简化决策树的高效连通域标记算法,进而提升了电力工程图纸的识别效率。仿真结果表明,与传统方法相比,所提算法在实现整体标记粘连字符的同时,显著提高了算法的执行效率,其执行时间约为传统方法的1/2。 展开更多
关键词 电力工程图纸 字符定位 字符提取 连通域标记 粘连字符 决策树简化 数学形态膨胀 标记效率
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基于稠密连接的通道混合式PCANet的低分辨率有遮挡人脸识别
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作者 秦娥 何佳瑶 +2 位作者 刘银伟 朱娅妮 李小薪 《高技术通讯》 CAS 北大核心 2024年第6期602-615,共14页
针对低分辨率有遮挡人脸识别问题提出了基于稠密连接的通道混合式主成分分析网络(DCH-PCANet)。现有的PCANet模型的卷积层只使用了通道无关式卷积(CIC)。通道无关式卷积由于未考虑特征图在通道方向上的相关性,可以更好地凸显单个特征图... 针对低分辨率有遮挡人脸识别问题提出了基于稠密连接的通道混合式主成分分析网络(DCH-PCANet)。现有的PCANet模型的卷积层只使用了通道无关式卷积(CIC)。通道无关式卷积由于未考虑特征图在通道方向上的相关性,可以更好地凸显单个特征图的局部纹理特征,对于补偿因低分辨率、遮挡等因素导致的特征损失具有重要意义,但也会强化遮挡区域的特征,从而放大坏特征的影响范围;而通道相关式卷积(CDC)由于充分考虑了各特征图在通道方向上的相关性,可以较好地抑制坏特征的作用,形成较为稀疏的特征图。在PCANet中添加了基于通道相关式卷积的特征图提取分支,形成了通道混合式PCANet;并且引入了稠密连接,以充分利用低阶特征提升有遮挡图像识别的鲁棒性。针对如下4种数据集进行了实验:受控环境、真实遮挡和模拟低分辨率的人脸数据集(AR人脸数据集),非受控环境、真实遮挡和模拟低分辨率的人脸数据集(MFR2和PKUMasked-Face),非受控环境、真实遮挡和真实低分辨率的人脸数据集(自建数据集)。实验结果表明,与现有方法相比,所提出的基于稠密连接的通道混合式PCANet具更好的遮挡鲁棒性和低分辨率鲁棒性,可以作为前沿方法的有效补充,提升其识别性能。 展开更多
关键词 有遮挡人脸识别 主成分分析网络(PCANet) 通道相关式卷积(CDC) 稠密连接
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城市轨道交通装配式地下车站新型构件连接方案的抗剪及抗震性能分析
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作者 周华海 《城市轨道交通研究》 北大核心 2024年第4期144-149,154,共7页
[目的]为了进一步推广地下装配式结构在城市轨道交通工程中的应用,应对城市轨道交通车站明挖装配式出入口施工的关键技术(尤其是新型构件连接方案)进行研究。[方法]设计了由2块尺寸相同的不等边C形标准构件(有2道横向裂缝)拼接而成的城... [目的]为了进一步推广地下装配式结构在城市轨道交通工程中的应用,应对城市轨道交通车站明挖装配式出入口施工的关键技术(尤其是新型构件连接方案)进行研究。[方法]设计了由2块尺寸相同的不等边C形标准构件(有2道横向裂缝)拼接而成的城市轨道交通车站装配式出入口结构,基于此结构提出了一种新型的构件连接方案。通过模型试验及数值模拟,研究了该新型连接节点的抗剪性能和抗震性能,得出了不同受力条件下的荷载-位移曲线、抗剪形态、抗震耗能及延性等指标,验证了该新型连接节点的可靠性。[结果及结论]装配构件的截面抗剪承载力远高于传统现浇截面抗剪承载力;型钢的存在可以充分保证试件的抗剪能力;“承插接口+型钢插板”是一种可靠的连接方式,其各项性能与现浇试件相比大致相当;型钢插入长度的变化对接缝处裂缝及其最大承载力的影响很小,建议选用的型钢插入长度等与构件厚度一致。 展开更多
关键词 城市轨道交通 地下车站 装配式结构 新型构件连接方案 抗剪承载力 抗震屈服能力
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基于KPCA特征量降维的风电并网系统暂态电压稳定性评估
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作者 张晓英 史冬雪 +1 位作者 张琎 张鑫 《兰州理工大学学报》 CAS 北大核心 2024年第2期96-103,共8页
针对电力系统暂态电压稳定性评估中所需特征量数据庞大,影响模型训练时间,降低计算效率等问题,提出了一种基于核主成分分析方法KPCA和CPSO-BP组合的风电并网系统暂态电压稳定性评估方法.首先根据输入特征采集原始特征集,采用核主成分分... 针对电力系统暂态电压稳定性评估中所需特征量数据庞大,影响模型训练时间,降低计算效率等问题,提出了一种基于核主成分分析方法KPCA和CPSO-BP组合的风电并网系统暂态电压稳定性评估方法.首先根据输入特征采集原始特征集,采用核主成分分析算法对特征量进行非线性数据处理,提取出最优的特征集.然后将降维后的特征集作为CPSO-BP神经网络输入量进行监督学习,将得到的模型按照临界故障切除时间裕度值的大小进行分类,将分类后的样本进行风电并网系统的暂态电压稳定性评估和临界故障切除时间裕度值预测.仿真分析结果表明,对输入特征进行降维,保留重要输入特征量,剔除冗余特征量,不仅简化了模型,还提高了网络评估的准确性和计算效率. 展开更多
关键词 风电并网 核主成分分析算法 降维 CPSO-BP神经网络 暂态电压稳定性评估
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