On the Application of Conditional Independence to Ordinal Data

A special log linear parameterization is described for contingency tables which exploits prior knowledge that an ordinal scale of the variables is involved. It is helpful, in particular, in guiding the possible merging of adjacent levels of variables and may simplify interpretation if higher-order interactions are present. Several sets of data are discussed to illustrate the types of interpretation that can be achieved. The simple structure of the maximum likelihood estimates is derived by use of Lagrange multipliers.     

Disaggregating food consumption parameters : Designing targeted nutritional interventions

This article is concerned with a new nutritional intervention strategy, which is based on the belief that malnourished people eat different types of food to the well-nourished. The calculation of disaggregated food consumption parameters can identify ‘inferior’ food commodities; and the subsidization of these commodities will target intervention to those most in need. The effectiveness of this policy depends on the understanding of its theoretical basis. The author introduces the policy maker to this by reviewing the theoretical basis for consumption analysis, and then several key studies.     

用PKPM系列程序优化分析高层结构的几点体会

介绍了作者应用PKPM系列的程序,在高层建筑结构设计计算中的体会,其中对若干抗震设计的控制参数的含义、电算分析与调整操作作了介绍,包括:位移比、周期比、侧刚比、受剪承载力比、剪重比、刚重比、层间位移角以及各种参数的调整等方面。供结构设计工程师参考。     

焓湿图(i-d图)中各状态参数的关系

文章主要涉及焓湿图中9个状态参数(温度t、含湿量d、相对湿度φ、焓i、空气水蒸气分压力Pq、湿球温度ts、露点温度tl、空气饱和水蒸气分压力Pq,b和空气饱和水蒸气含湿量db)及对各状态参数之间关系的理解,作者用图示的方法说明这些状态参数之间的关系。     

钨系高速钢带状共晶碳化物级别的定量数值测定

为了实现高速钢带状碳化物的自动定量评级,在计算机图像仪上对钨系高速钢带状共晶碳化物不均匀度的国家标准评级图片进行了分析测定,还对实验数据进行了多种拟合处理.结果表明:碳化物总面积百分数、碳化物条带的平均宽度和条带内碳化物占整个碳化物的比例,可以作为衡量钨系高速钢带状共晶碳化物不均匀度的特征参数.     

Arrendamiento o compra de inmovilizado utilizando el endeudamiento

This work introduces the VNA (Clear Advantage of the Lease) criterion with the goal of letting any company that wants to incorporate fixed assets into his productive process, know whether it is better to realize it by means of a lease or through a debt-financed purchase. After analyzing the main lease types, the VNA criterion is applied to two different assumptions which also include an approximation to the legal Spanish regulation. Anyway, given its flexibility, the above mentioned criterion can be adapted to different cases and regulations. All kinds of results are obtained in this work, depending on the assumption adopted and on the variability granted to the different parameters used. In this respect, far from making hasty a priori affirmations on the convenience of leasing or buying fixed assets by means of debt, we recommend an ad hoc analysis in every case.     

北京市地区畜禽养殖污染总量估算

[目的]随着我国经济的发展,畜禽养殖业发展迅速的同时,日益增加的畜禽粪便排放也带来了生态环境污染问题。北京市由于特殊的经济和政策环境,畜禽产品需求量较大从而畜禽粪便排放量进一步增多,因此必须要加强对于北京畜禽养殖产业污染的防治,为生态环境保护及居民身体健康提供坚实保障。[方法]文章采用随机抽调与实地调研相结合的方式,了解北京市地区主要畜禽养殖情况,进一步使用畜禽养殖主要污染物排放量计算参数估算北京地区畜禽养殖主要污染物排放量。[结果]北京地区多以养殖生猪、牛、肉鸡为主;北京市11个区县产污量较大的3个区依次是顺义区、房山区和平谷区,主要污染物为化学耗氧量和总氮;通过实地调研,发现北京地区畜禽养殖存在以下问题:(1)资金技术欠缺,无法按照要求购买必须的污染防治设备;(2)小型养殖户应对风险能力弱;(3)部分养殖户抱侥幸心理,认为投资污染防治设备没有必要。[结论]加大畜禽养殖污染防治财政补贴力度,鼓励养殖者使用新型排污设备;各个区县主管农业的部门定期组织养殖者进行免费培训;加大扶持力度,促进有机肥市场发展;发挥资金及技术优势,优势互补;引导居民调整饮食结构,倡导健康生活与饮食习惯。     

1Cr18Ni9Ti CO_2激光焊接的工艺分析

激光焊接技术作为一种重要的现代熔融焊接技术,广泛应用于机械、化工、核电、电子工业等行业,它使用激光束作为其主要能量来源,将激光直接冲击在焊件的接头处,实现了自动化高速焊接。本文以1Cr18Ni9Ti CO2激光焊接为例,研究分析了CO2激光焊接的工艺特点及焊接质量的影响因素,并对不同厚度1Cr18Ni9Ti材料进行了焊接实验,结果显示厚度越大,允许的最大焊速越小、焊缝宽度越宽。     

350MW超临界循环流化床电厂热经济指标优化

本文借鉴国内同容量机组的设计经验,对神华河曲2×350MW超临界循环流化床燃煤机组进行了热经济指标优化,这些优化措施极大的降低了机组供电煤耗,提高了机组的热效率。     

新岩石物理参数研究

对于非常规的储层,例如页岩气,它的储层区是脆性的。在描述不同岩石物理的参数中,杨氏模量E是衡量岩石的脆性的。计算杨氏模量E时,需要有效密度,而计算密度时需要的大偏移距地震资料通常是很难得到的。针对这种情况提出了一种新岩石物理参数E,即杨氏模量和密度的乘积,通过与属性的对比体现其在AVO叠前反演中的优势。