基于计算机视觉的电厂车辆智能监测系统设计与实现

针对电厂运煤车辆的管理,设计并实现了一个基于计算机视觉的电厂运煤车辆智能监测系统.提出了一种基于颜色分割和数字形态学处理相结合的车牌定位算法和一种基于Sobel灰度边缘算子的车牌倾斜校正算法.实际应用表明,该系统有很强的鲁棒性,可以处理污损、变形、各种光照条件下的车牌,并且速度快、准确率高     

基于中文分词的文本相似度动态规划算法

针对传统的基于动态规划的对论文的文本相似度计算的不足,提出了一种基于中文分词和动态规划的论文文本相似度计算方法,并对此进行了讨论。该方法克服了一般基于动态规划的计算方法所具有的效率低,判断准确率低的缺点。通过对实际中的论文数据库中论文进行测试和分析,该算法能提高计算准确率,并一定程度上提高了运算速度,可以应用于论文防抄袭系统中。     

Power output characteristics of a finitely segmented faraday mhd generator

Accounting for the effect of finite segmentation of electrodes as a reduction of both the electrical conductivity of the working fluid and the Hall parameter, we have derived expressions of power density for a finitely segmented Faraday MHD generator with and without considerable electrode voltage drop. While calculating the actual loading factor through the electrode voltage drop, the latter has been estimated in a finitely segmented Faraday MHD generator with and without ash in the combustion products. The results have been discussed and compared with earlier results where the considered effects are not taken into account. It is found that the effects of finite segmentation of electrodes and the electrode voltage drop modify the power output characteristics significantly.     

Microscopic melanoma detection and classification: A framework of pixel‐based fusion and multilevel features reduction

The numbers of diagnosed patients by melanoma are drastic and contribute more deaths annually among young peoples. An approximately 192,310 new cases of skin cancer are diagnosed in 2019, which shows the importance of automated systems for the diagnosis process. Accordingly, this article presents an automated method for skin lesions detection and recognition using pixel‐based seed segmented images fusion and multilevel features reduction. The proposed method involves four key steps: (a) mean‐based function is implemented and fed input to top‐hat and bottom‐hat filters which later fused for contrast stretching, (b) seed region growing and graph‐cut method‐based lesion segmentation and fused both segmented lesions through pixel‐based fusion, (c) multilevel features such as histogram oriented gradient (HOG), speeded up robust features (SURF), and color are extracted and simple concatenation is performed, and (d) finally variance precise entropy‐based features reduction and classification through SVM via cubic kernel function. Two different experiments are performed for the evaluation of this method. The segmentation performance is evaluated on PH2, ISBI2016, and ISIC2017 with an accuracy of 95.86, 94.79, and 94.92%, respectively. The classification performance is evaluated on PH2 and ISBI2016 dataset with an accuracy of 98.20 and 95.42%, respectively. The results of the proposed automated systems are outstanding as compared to the current techniques reported in state of art, which demonstrate the validity of the proposed method.     

A 2D finite element analysis of the effect of numerical parameters on the reliability of Ti6Al4V machining modeling

Abstract

The numerical analysis, based on the finite element modeling (FEM), presents nowadays an efficient computational tool. It allows a better understanding of several thermo-mechanical phenomena involved during the machining process. However, its reliability heavily depends on the accurate definition of the numerical model. In this regard, a FE analysis focused on the 2D modeling of the Ti6Al4V dry orthogonal machining was carried out in this study. The relevance of different numerical meshing approaches and finite elements topologies was studied. The effect of the friction coefficient on the numerical chip morphology, its geometry, the cutting and the feed forces was investigated. The adequacy of several compared adaptive meshing approaches, in terms of the modeling of severe contact conditions taking place around the cutting-edge radius, was underlined in the current study. However, numerical serrated chips, closer to the experimental ones, were only predicted when the pure Lagrangian formulation was adopted and a proper determination of the failure energy was carried out. The definition of different mesh topologies highlighted the efficiency of the 4-node quadrangular mesh, with a suitable edge length, in increasing the agreement with the experimental data, while reducing the computing times.     

基于深度语义分割的多源遥感图像海面溢油监测

针对遥感图像海面溢油区域通常受到斑噪声以及强度不均等因素的影响,从而导致溢油区域监测效果较差的问题,本文引入了深度语义分割的方法,将深度卷积神经网络与全连接条件随机场相结合,形成端对端连接。以Resnet结构为基础,首先通过深度卷积神经网络对多源遥感图像粗分割并作为输入,然后经过改进的全连接条件随机场,利用高斯成对势和平均场近似定理,建立条件随机场形成递归神经网络作为输出。通过多源遥感图像对海面溢油区域进行监测,并利用可见光图像估计溢油区域面积。实验在所建立的多源遥感图像数据集上与其它先进模型进行对比,结果表明本文方法提高了溢油区域的分割精度以及精细细节程度,平均交并比为82.1%,监测效果具有明显地改善。     

1990年代北京市外商投资空间分布动态特征研究

以北京市的全球化发展为背景,等距选取1992、1995、1998三个断面年,采用栅格模型(Grids System),对1990年代前、中、后三个时期全部及第二、三产业外商直接投资在北京市域的空间分布特征进行实证分析,揭示了1990年代北京外商投资空间分布的两大动态特征:集聚-扩散-集聚的交互过程和向中心和向外围的双向同步推进.北京作为典型的发展中国家大城市,在1990年代表现出全球化以及由工业化向非工业化转变的同步进程,在空间上外资工业项目促进了在城市边缘区城市空间的定向突破,同时第三产业外资项目加速了其中心化的过程.     

基于改进的K-means聚类图像分割算法

介绍一种采用K—L变换、二维向量小波和改进的K—means结合的图像分割算法。阐述和分析了二维向量小波变换和Laws纹理能量测度，得出图像每个像素点可用9个纹理特性来描述的结论。运用K—means算法的思想对其进行改进，最后得出分割后的图像。试验结果证明，运用以上处理方法可显著提高分割速度和精度。     

Image segmentation of small defects in precision weldments with complex structure

In this paper, the X-ray nondestructive test method of small defects in precision weldments with complex structure was presented. To resolve the difficulty of defect segmentation in variable grey image, the image processing based on Visual Basic programming method was adopted. The methods of automatic contrast and partial grey stretch were used to enhance the X-ray detection image which has relatively low contrast, then automatic threshold method was carried out to segment the two high intensity zones, and weld zones which contain the small defects was extracted. Smoothing and sharpen processing were proceeded on the extracted weld zones, and small defects in X-ray detection image of weldments with complex structure were segmented by using the method of background subtraction in the end. The effects of raster were eliminated, and because of that the image processing was only proceeded on the extracted weld zones, the calculated speed using the above provided algorithm was improved.     

一流大学办学理念的基本特征及其形成条件

思想指导行动 ,即理念指导实践。一流的办学理念是一流大学办学成功的关键。以美国和英国为首的发达国家的世界一流大学的办学理念具有许多共同特征 ,即伦理本位、学术自由、使命指引、传承创新。基于此内涵特点的大学办学理念之形成条件主要有这样几个共性特征 ,即杰出校长的教育理念是关键、著名专家学者的贡献是基础、社会文化环境的影响是背景、国内外高水平交往是条件、大学享有自由权利是根本。