三种FID信号特征参数提取方法及其对比研究

核磁共振找水仪采集信号的特征参数准确度对地下水的研究有很重要的意义．特征参数提取是否精确直接影响了反演解释含水层位置、含水量、以及孔隙度等水文地质信息．针对特征参数的多种提取方法,本文主要围绕线性拟合、非线性拟合和自相关拟合三种数据拟合方法进行对比,找出不同信噪比下最适合的特征参数提取方法．野外实测数据和反演结果也验证了方法的有效性．     

基于PID参数自整定的动态可调温度控制系统设计

为了提高煤矿降温系统的综合运行效益,设计了一种基于PID参数自整定的温度控制系统。为了满足动态可调温度的应用需求,利用PID控制器能够实现温度精确调节的目的,详细研究了PID参数自整定的方法,给出了设计的PID参数自整定主要函数和实现过程,得出了PID参数自整定温度控制系统.     

汽车轮胎压力与TPMS系统的发展

随着汽车进入家庭步伐的加快,人们对汽车的安全性能的要求越来越高,作为提高汽车主动安全性能措施之一的TPMS系统受到人们越来越多的关注。论文根据分析轮胎气压大小对轮胎性能和行驶性能的影响,指出对行驶中的汽车轮胎气压进行监测与报警的必要,论述TPMS系统的原理,并提出引导TPMS系统发展的三点看法。     

鸭河口水库浮游动物群落及其水质评价

为了掌握鸭河口水库水体的营养现状,为南阳市饮用水源的水质管理及供水处理提供理论指导,于2013年11月对鸭河口水库浮游动物和水质理化指标进行监测.按浮游动物水样采集标准方法采样,采用污水生物系统法和营养状态指数法对水源区进行富营养化程度评价.浮游动物有27种(隶属19科21属),其中枝角类和轮虫最多,均为9种,桡足类6种,原生动物3种,仅检测到1种β-中污(βm)指示种;浮游动物平均密度为2324 ind./L;水质理化监测指标中总氮超标,其他符合地表水Ⅰ类标准;库体水质营养状态指数为48.13.结合浮游动物群落与水质指标综合分析,鸭河口水库处于中营养状态.     

基于层次分析法汽车轮胎花纹的选择

针对不同轮胎花纹对汽车性能影响不同,使用层次分析、数理统计分析方法,分别探究了不同轮胎花纹的安全性和耐磨性以及节能性,构建了花纹轮胎最适选择等模型,使用Matlab、Visual C＋＋等软件编程,得到不同车型在不同路面及不同使用需求条件下轮胎花纹的选择方法.     

平煤八矿瓦斯抽采钻孔一注式封孔参数研究

针对瓦斯抽采钻孔封孔质量差,抽采浓度低的问题,提出在平煤八矿试验一注式封孔装置及工艺;通过考察封孔参数和钻孔孔口瓦斯浓度之间的关系,确定了穿层钻孔抽采瓦斯变化特征,煤层顺层钻孔最佳封孔参数;研究结果对采用类似封孔装置及工艺的矿井,确定最佳封孔参数提供了参考。     

一种基于立方体的摄像机内参数标定方法

摄像机标定方法是计算机视觉的重要内容之一。提出了一种基于立方体的标定方法。该方法的模型为立方体,从3个或多个不同的方位摄取图像,由直径的正交关系获得3组正交灭点,从而线性的求出摄像机的5个内参数。模拟图像和真实图像实验表明,文章的自标定方法有较好的灵活性和较高的鲁棒性。     

Prediction equation for head volume of Japanese young adults

Accurate measurement of head volume is indispensable for precise assessments of body composition determined by hydrostatic weighing without head submersion. The purpose of this study was to establish a prediction equation for head volume measured by the immersion method from multiple regression analysis using head parameters (head circumference, head length, head breadth, neck girth and head thickness) as independent variables. The participants were 106 Japanese young adults (55 males and 51 females) aged 17?–?27 years. Intra-class correlation coefficients (ICCs) for each head parameter and head volume in males and females were very high (ICC = 0.993?–?0.999, 0.992?–?0.998). Head circumference was closely related to head volume measured by the immersion method (r = 0.719, 0.861, P <?0.05), and was the most important parameter for the prediction equation in both sexes. Head breadth was related poorly (r = 0.475, 0.500, P <?0.05) and showed a small individual difference. It was, therefore, excluded from the independent variables. The prediction equation for males was predicted head volume = 122.10X ₁ + 106.19X ₃ + 37.16X ₄ - 89.46X ₅ - 4754.93, R = 0.909, SEE = 121.75?ml, and that for females was predicted head volume = 213.83X ₁ + 45.24X ₃ + 36.85X ₄ - 74.34X ₅ - 8912.43, R = 0.913, SEE = 136.26?ml (where X ₁ = head circumference, X ₃ = head length, X ₄ = neck girth, X ₅ = head thickness, and SEE = standard error of the estimate). The limits of agreement for predicted and measured head volume were –?234.5 to 234.1?ml for males, and ??261.0 to 261.0?ml for females. In cross-validation groups of both sexes, there were no significant differences between measured head volume and predicted head volume. The correlation coefficients between measured head volume and predicted head volume in males and females were 0.894 and 0.908, respectively. The predicted head volume from prediction equations was considered to have high reliability and validity.     

Sport and Mathematics: A Definition and Delineation

Abstract

Charles O. Dotson begins this section by discussing the concept of research reflecting high density logic, indicating that the most desirable research papers are those sharply reasoned contributions with maximal application of inductive syllogisms. This is followed by a critical review of the quality of research published in the Research Quarterly over the past 50 years. Dotson suggests that much of this research reflects low logical density, and concludes his paper with several recommendations for upgrading the logical density of research in physical education. The second paper in this section was prepared by Robert W. Schutz, who discusses the role of mathematical analysis in the study of sport strategy and structure and in the development and verification of theories of motor behavior. Schutz delineates a field of sports studies labelled sport mathematics and classifies topics of investigation amenable to mathematical analysis. He presents arguments supporting the identification of mathematics and sport as a subdiscipline within sports studies. Mathematical analysis in the study of motor behavior, on the other hand, is viewed as a methodology.     

单晶硅太阳电池制备工艺探讨

本文介绍目前晶体硅太阳电池制造工艺,通过实验给出各个工艺流程的工艺参数及可调节范围,说明各环节对太阳电池的贡献及注意问题。提出了通过优化各工艺流程来提高晶体硅太阳电池效率的一些方法。