农药pH值测定方法的研究

通过对原国家标准 GB1601-79(83)农药氢离子浓度的测定方法,以及 CIPACMT75 pH 值的测定方法的研究比较,建立了一种适用于农药原药、粉剂、可湿性粉剂、乳油等的水分散液(或水溶液)pH 值测定的新方法,即新的国家标准方法。新法等效采用了 CIPAC MT75 pH 值的测定方法,使农药 pH 值的测定更加准确合理,并可在国际范围内通用。     

驾驶员转向特性分类与在线辨识研究

针对汽车驾驶员转向特性分类与在线辨识问题,基于驾驶模拟器实验台,设计典型实验工况,选取具有一定驾驶经验的驾驶员进行实验研究。采集驾驶员转向过程实验数据并提取特征值,应用模糊C均值聚类算法将驾驶员转向特性分为谨慎型、一般型和激进型三类;根据分类实验数据应用BP神经网络算法建立驾驶员转向特性辨识模型,对模型辨识准确度进行离线验证,并基于辨识模型设计在线辨识方法。实验结果表明:研究方法能够实现对驾驶员转向特性的合理分类和在线准确辨识。     

基于温湿度变化对蒸压加气混凝土墙体变形影响试验研究

本文对加气混凝土墙体在温湿度变化下的开裂问题进行试验研究。通过调整内外墙体温度、湿度变化研究加气混凝土砌块应力应变的变化规律;利用ANSYS软件理论分析温差对墙体应力应变的影响。结果表明:随着内外墙体温差的增大,加气混凝土墙体的应变值越大;随着湿度的变化,应变值的变化不大。     

谈拉格朗日中值定理在高等数学课程教学中的应用

拉格朗日中值定理是微分学的基础定理之一,是连接函数及其导数之间关系的桥梁,有着广泛的应用。文章用七个例题,从三大方面总结了拉格朗日中值定理的灵活应用。这对于正确的理解和掌握拉格朗日中值定理,以及以后进一步学习数学具有重要的作用和深远的意义。     

International Trade

Values of net oil imports(-)/exports for Austria, Belgium, Denmark, Finland, France, Germany, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, the United Kingdom, Japan, Canada, the United States and Australia. Updated on a monthly basis. Number of imports for Belgium, France, Germany, Greece, Republic of Ireland, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, and Other EU-15 (EU-15), Norway, Poland, Switzerland, Turkey, and Other Europe (OECD Europe), Canada, Chile, Mexico, and the United States (OECD Western Hemisphere), and Australia, Japan, Republic of Korea, New Zealand, (OECD Asia-Pacific), and Total OECED. Current data for Austria, Belgium, Finland, France, Germany, Greece, Italy, Netherlands, Portugal, Spain, Sweden, the United Kingdom, Other EU-15 (EU-15), Czech Republic, Hungary, Poland, Slovakia, Turkey, and Other Europe (OECD Europe), Canada, Mexico, and the United States (OECD Western Hemisphere), Australia, Japan, Republic of Korea, and New Zealand (OECD Asia-Pacific). Updated on a monthly basis. Current data for principal importers of natural gas and the amount in which they import from United States, Republic of Korea, United Kingdom, France, Japan, Italy, Germany and Spain (Table 19.1). Current data for principal exporters of natural gas and the amount they export to Canada, Trinidad and Tobago, the United States, Netherlands, Norway, Russia, Turkmenistan, Qatar, Algeria, Nigeria, Indonesia, Malaysia and Australia (Table 19.2). Updated on a monthly basis.     

基于张量奇异值分解的人脸识别方法

在人脸识别领域应用张量奇异值分解( TSVD)来进行人脸特征的表示和提取,克服了过去的提取方法,如主成分分析法( PCA)等过于依赖拍摄条件的缺点。 TSVD将数据转换成三维线性模型,所以能避免二维线性方法中条件改变则精确度下降的问题,使得识别算法在变化的条件下获得了相对稳定的结果。在此基础上对算法进行了优化,利用矩阵分解,在不影响算法正确率的情况下,有效减少计算量,提高算法效率。基于Matlab对该算法进行了四组实验,并将结果与用PCA方法得到的结果对比,验证了该识别算法在变化条件下显著的正确性以及稳定性;同时,对优化的TSVD算法进行了实验验证,在数据量较大的情况下,该算法速度明显提高。     

KR字符串匹配算法的研究与实现

字符串匹配是判断模式串(短串)是否是文本串(长串)的子串。KR算法是一种随机串匹配算法,详细介绍KR串匹配算法的算法描述及代码实现过程,并对该算法进行测试,讨论该算法的实现效率。     

一例Java语言与C语言代码运行效率的比较

通过构建一个算法效率测试平台的简易模型,比较Java语言和C语言两种主流语言在实际环境中执行同一算法时所花费时间的区别．揭示C语言在算法效率测试平台上相对于Java语言具有执行速度快、效率高的特点．为程序设计人员在编写算法效率测试平台时选用何种语言进行编程提供了一种参考。     

A Bayesian approach to estimate the marginal loss distributions in operational risk management

One of the main problems in operational risk management is the lack of loss data, which affects the parameter estimates of the marginal distributions of the losses. The principal reason is that financial institutions only started to collect operational loss data a few years ago, due to the relatively recent definition of this type of risk. Considering this drawback, the employment of Bayesian methods and simulation tools could be a natural solution to the problem. The use of Bayesian methods allows us to integrate the scarce and, sometimes, inaccurate quantitative data collected by the bank with prior information provided by experts. An original proposal is a Bayesian approach for modelling operational risk and for calculating the capital required to cover the estimated risks. Besides this methodological innovation a computational scheme, based on Markov chain Monte Carlo simulations, is required. In particular, the application of the MCMC method to estimate the parameters of the marginals shows advantages in terms of a reduction of capital charge according to different choices of the marginal loss distributions.     

基于综合赋权的风险企业增值潜力灰色评价方法

风险企业的增值潜力可体现未来获利能力,故增值潜力应由获利能力的关键基础、前提条件及保障因素构成,据此构建了风险企业增值潜力评价指标体系.将综合赋权引入灰色综合评价方法,由层次分析法(AHP)、熵权法得到主观权和客观权;再运用线性规划方法求得对两类权重加权的权值,构造"综合权重",最后进行灰色评价.算例表明,该方法可行,且评价结果既符合客观实际又能反映主观要求.