无参考图像质量评价研究进展

图像质量评价一直是图像处理和计算机视觉领域的一个基础问题,图像质量评价模型也广泛应用于图像/视频编码、超分辨率重建和图像/视频视觉质量增强等相关领域。图像质量评价主要包括全参考图像质量评价、半参考图像质量评价和无参考图像质量评价。全参考图像质量评价和半参考图像质量评价分别指预测图像质量时参考信息完全可用和部分可用,而无参考图像质量评价是指预测图像质量时参考信息不可用。虽然全参考和半参考图像质量评价模型较为可靠,但在计算过程中必须依赖参考信息,使得应用场景极为受限。无参考图像质量评价模型因不需要依赖参考信息而有较强的适用性,一直都是图像质量评价领域研究的热点。本文主要概述2012—2020年国内外公开发表的无参考图像质量评价模型,根据模型训练过程中是否需要用到主观分数,将无参考图像质量评价模型分为有监督学习和无监督学习的无参考图像质量评价模型。同时,每类模型分成基于传统机器学习算法的模型和基于深度学习算法的模型。对基于传统机器学习算法的模型,重点介绍相应的特征提取策略及思想;对基于深度学习算法的模型,重点介绍设计思路。此外,本文介绍了图像质量评价在新媒体数据中的研究工作及图像质量评价的应用。最后对介绍的无参考图像质量评价模型进行总结,并指出未来可能的发展方向。     

高阶统计量在故障诊断中的应用研究

近年来,国内外有关轴承的研究表明,轴承的振动与噪声对机电设备的寿命有着重要的影响。其中,故障信号的提取是一个关键问题。在轴承、齿轮等零件的故障诊断中,常常应用包络分析提取冲击信号,但当信噪比很低及故障信息十分微弱时,包络分析往往也很难获得满意的结果。本文以轴承为对象,在提取包络信号的基础上,进一步计算包络信号的高阶统计量估计值,成功地将滚子故障和外圈故障等信号进行了分离,效果十分明显。     

虚拟仪器实现的零件加工精度测量与分析系统

论述利用LabVIEW开发平台，实现机械零件加工精度分析系统中数据的采集，显示和存储，并通过大量数据的分析，得出加工误差的分布曲线图、X-R质量控制图等信息。     

基于数据融合与统计的设备参数劣化分析

在火力发电站的热力设备中，它们的正常运行都是通过各种曲线来判断的，参数在允许的范围内变化说明设备处于正常运行，然而当参数偏离某一范围发生劣化时，就意味设备即将发生故障。本文利用数据融合与数据统计的方法对设备参数劣化分析，就是利用历史数据，通过趋势建模分析预测出设备发生故障的时间地点．再进行及时相应处理，从而有效的消除故障．保证机组经济．安全运行。     

基于表面肌电信号的前臂手部多运动模式识别

基于表面肌电信号的肢体运动模式识别是假手仿生控制的基础，SEMG的个体差异与识别率是肌电假手实用化必须面对的问题。本文根据SEMG的频谱特性提出了一种新的特征提取方法——功率谱比值法。该方法的主要特点是以实时取得的SEMG功率谱信号为基础，确定最大功率谱附近的谱能量与全信号段谱能量之比为特征值，将人的个体差异影响降低到最低程度。模式分类器采用特别设计的Bayes统计决策算法，该方法在非特定人的条件下应用于前臂肌群的多运动模式识别时，识别正确率达到84％，已具备一定的实用性。     

Second-order stereology of benign and malignant alterations of the human mammary gland

The purpose of the present study was a quantitative characterization of the three-dimensional arrangement of the epithelial component of benign and malignant alterations of the female breast by combining stereology with stochastic geometry. Twenty cases of fibrous mastopathy and 20 cases of invasive ductal mammary cancer were studied at the light microscopic level. Segmentation of the epithelial tissue component was performed with an image analyser. From the resulting binary images, unbiased estimates of the covariance C(r) and the intensity V_v of the epithelial volume component were obtained automatically by computer. From these data, estimates of the correlation function k(r), of the pair correlation function g(r), of the radial distribution function RDF(r) and of the reduced second moment function K(r) of epithelial volume were determined. The estimates of C(r) and RDF(r) differed between groups, but these functions depend on spatial pattern and V_v. As carcinomas showed a significantly higher epithelial volume density V_v than mastopathies, estimation of C(r) and RDF(r) alone did not permit a safe distinction between possibly different types of spatial arrangement of epithelium in the benign and malignant lesions. Analysis of the estimates of k(r), g(r) and K(r), which are not influenced by V_v, showed definite interaction between epithelial volume elements, with clustering at short distances and repulsion at long distances. In both groups, the null hypothesis of purely random arrangement of epithelium had to be rejected. The clearest distinction between groups was obtained by estimation of g(r), which showed that short-range, tubular pattern as well as long-range, lobular architecture are better preserved in benign than in malignant lesions. The low interindividual scatter of k(r), g(r) and K(r) indicates a high biological significance of spatial pattern, which is presumably under strict genetic control. Potential uses of the method are: (i) the identification of biomathematical models which could contribute to a better understanding of the growth processes involved, (ii) conditional simulation of the underlying three-dimensional structures by computer, and (iii) supporting the diagnosis of mammary lesions with borderline histopathological appearance.     

Explorative statistical analysis of planar point processes in microscopy

Basic methods of explorative statistical analysis for stationary and isotropic planar point processes are briefly and informally reviewed. At the explorative level, planar point patterns may be characterized in terms of the intensity, the K-function and the pair correlation function. These second-order functions enable one to classify a given point process as completely random, clustering or repulsive. The repulsive behaviour may be quantified by an estimate of the hard-core distance. In the exploratory approach, the statistics are essentially free from model assumptions. Second-order spatial functions have been estimated to characterize genuine planar point processes in the macroscopic domain, for example in forestry, geography and epidemiology. For light microscopy and transmission electron microscopy, two situations are distinguished, which may be summarized as the genuine planar case and the stereological case. In the genuine planar case, a direct interpretation of the results of spatial statistics is feasible. Here, monolayers in cell culture, intramembranous particles on freeze fracture specimens and amacrine cells of the retina are mentioned as examples. In the stereological case, point patterns are generated by sections through 3D structures. Here the observed point patterns may arise as the centres of sectional profiles of particles, or as centres of sectional profiles of spatial fibre processes. In both situations, exploratory spatial point process statistics allow a quantitative characterization of sectional images for the purposes of group comparisons and classification. Moreover, for spatial fibre processes it has recently been shown that the observed pair correlation function of the centres of the fibre profiles is an estimate of the reduced pair correlation function of the fibre process in 3D. Hence for fibre processes a stereological interpretation of point process statistics obtained from sections is an additional option.     

静力触探数据整理中的标准差统计方法

用静力触探作为实例 ,分析几种标准差的统计方法的使用情况 ,指出了不适当的统计方法的原因     

关于火灾调查工作改革与发展思路的探讨

结合江西省实际 ,对火灾调查工作立案标准、火灾统计、火灾事故责任、放火案件调查和火灾物证的提取与送检进行了探讨     

火警事件统计系统中英比较分析

火警事件统计系统需要不断更新，以适应当代社会火灾形势与消防救援水平的发展，为科学分析预测火灾形势奠定基础。运用文献研究和对比分析等方法，对中英火警事件统计系统进行对比分析，着重比较分析统计指标体系和指标分类等方面的差异。研究结果可为今后我国火灾统计工作的更进一步发展提供参考。