An interactive lung field segmentation scheme with automated capability

Feasible clinical application of any automated segmenting methodology demands more than just accuracy. Amendment to the automated delineation is necessary when the algorithm fails, however, integrated solution to such a scenario is largely absent in literature. Hence in this survey we devised an architecture that does both the automated and interactive lung field localizations using a single segmenting engine—random walker algorithm—so that intuitive amendment is only necessary when the automated generated delineation is unsatisfactory. The algorithm proceeds by first extracting 18 intensity profiles running horizontally, each of them equally spacing apart, and in each intensity profile three extreme points denoting the two lungs and the esophagus are determined through profile matching. This done, the algorithm removes profiles that do not intersect with the lung, and the rest of the extreme points are plugged into random walker algorithm to perform segmentation. The achieved accuracy in localization by the above was 0.8875 in terms of overlap measure (the maximum value for this parameter is 1) over 341 images. In the case where unsatisfactory delineation prompts amendment necessary, the user can interactively segment the lung by just a shift on some of the previous-determined points to the desired locations, and random walker algorithm is run again with the amended input. By such a fusion, the benefits of both the automated and interactive segmentation are shared in a single architecture.     

On Detectability and Observability of Discrete‐Time Stochastic Markov Jump Systems with State‐Dependent Noise

This paper mainly studies the notions of detectability and observability for discrete‐time stochastic Markov jump systems with state‐dependent noise. Two concepts, called “W‐detectability” and “W‐observability,” for such systems are introduced, and are shown to coincide with the other concepts on detectability and observability reported recently in literature. Moreover, some criteria and interesting properties for both W‐detectability and W‐observability are obtained.     

Color image segmentation using adaptive unsupervised clustering approach

This paper presents the Region Splitting and Merging-Fuzzy C-means Hybrid Algorithm (RFHA), an adaptive unsupervised clustering approach for color image segmentation, which is important in image analysis and in understanding pattern recognition and computer vision field. Histogram thresholding technique is applied in the formation of all possible cells, used to split the image into multiple homogeneous regions. The merging technique is applied to merge perceptually close homogeneous regions and obtain better initialization for the Fuzzy C-means clustering approach. Experimental results have demonstrated that the proposed scheme could obtain promising segmentation results, with 12% average improvement in clustering quality and 63% reduction in classification error compared with other existing segmentation approaches.     

高校应用写作教学中的困惑与出路

应用写作以其广泛的社会需求而受到高校的关注,但在教学中存在着一些问题,主要有:不重视任课教师的选配、任课教师职称评定难、任课教师的理论教学与写作实践脱节、学生的言语能力与写作水平下降。为切实解决高校应用写作教学中存在的问题,为社会培养复合型应用人才,学校领导要充分重视,从政策上予以保证;同时,教师要从事一些秘书写作工作,将理论与实践结合起来。而重视教材建设等,是解决上述问题的重要措施。     

探析网络安全防范体系及设计原理

随着互连网的高速发展,网络技术已经融入到人们生产、生活中的各个领域,但网络安全问题也越来越严重.本文针对网络安全防范的概念、互联网可能存在的风险、以及设计原理进行了一些探析.     

巧用Word替换命令

随着计算机技术迅猛发展并在各个领域应用得到相应推广,Office是目前最流行,Word在字处理方面应用基本上有90%占有率.文字处理方面,对Word简单输入排版,如替换命令,只是用它来查找和替换文字,对其更深层次应用如:替换字符格式、段落标记、分页符等方面还不了解.现谈谈Word中替换命令几点妙用.     

压差矢量水听器阵波束形成的优化

以各向同性噪声作为背景噪声场,对矢量水听器阵波束形成的优化方法进行了系统的研究.在分析各向同性噪声场中声压、振速相关性的基础上,利用最大信噪比准则推导了基阵的最佳增益与噪声场特性和阵列流形之间的关系,提出利用最佳增益权对阵列接收信号进行波束形成处理.通过对矢量水听器阵进行分解,将最佳增益波束形成引入矢量阵信号处理中.以二维压差矢量水听器阵作为接收基阵进行了仿真计算和湖上试验,结果表明,矢量阵的最佳增益波束形成可以获得性能更优的波束和更大的空间处理增益.     

An improved physically-based method for geometric restoration of distorted document images

In document digitization through camera-based systems, simple imaging setups often produce geometric distortions in the resultant 2D images because of the non-planar geometric shapes of certain documents such as thick bound books, rolled, folded or crumpled materials, etc. Previous works have demonstrated that arbitrary warped documents can be successfully restored by flattening a 3D scan of the document. These approaches use physically-based or relaxation-based techniques in their flattening process. While this has been demonstrated to be effective in rectifying the image content and improving OCR, these previous approaches have several limitations in terms of speed and stability. In this paper, we propose a distance-based penalty metric to replace the mass-spring model and introduce additional bending resistance and drag forces to improve the efficiency of the existing approaches. The use of Verlet integration and special plane collision handling schemes also help to achieve better stability without sacrificing efficiency. Experiments on various document images captured from books, brochures and historical documents with arbitrary warpings have demonstrated large improvements over the existing approaches in terms of stability and efficiency.     

Improvements of nonlinear dynamic modeling of hot-film MAF sensor

The operating procedure of engine requires that the mass air flow (MAF) sensor can measure the pulsation air flow accurately. Therefore the MAF sensor must possess fast response speed. It is necessary to study the dynamic characteristic of the MAF sensor. Both the experimental equipments and method used by authors previously are improved to obtain the sensor response data accurately in this paper. The static and dynamic separable modeling method is adopted to build the uniform nonlinear dynamic model of the hot-film MAF sensor in the Hammerstein and Wiener forms, which can describe the large/small flow-rate and positive/negative step responses. The performance indexes are calculated by the actual and model responses.