Difunctorial Semantics of Object Calculus

In this paper we give a denotational model for Abadi and Cardelli's first order object calculus FOb_1+×μ (without subtyping) in the category pCpo. The key novelty of our model is its extensive use of recursively defined types, supporting self-application, to model objects. At a technical level, this entails using some sophisticated techniques such as Freyd's algebraic compactness to guarantee the existence of the denotations of the object types. The last sections of the paper demonstrates that the canonical recursion operator inherent in our semantics is potentially useful in object-oriented programming. This is witnessed by giving a straightforward translation of algebraic datatypes into so called wrapper classes.     

信息融合模型及其应用

针对现有信息融合模型过于抽象、不利于信息融合应用系统的设计等问题,本文提出了信息融合通用模型.该模型采用面向对象和形式化相结合的方法,解决了现有信息融合模型缺乏可重用性、可靠性等问题.最后,以智能交通系统ITS为例,简要说明如何利用信息融合通用模型应用于ITS的设计.     

对“文化景观”概念及其范畴的探讨

首先阐述了基于过程的景观内涵,赋予苏尔"文化景观是附着在自然景观之上的人类活动形态"这一经典概念表述以新的涵义。接着对可视或非可视、客观或主观、物质或非物质等文化景观现象的基本属性展开深入探讨。在此基础上,指出人类的生活活动作为文化景观的一部分,对文化景观具有特殊意义。并以之为契机,逐层深入地揭示出文化景观概念范畴的内在结构。     

我国无缝钢管生产的发展(上)

回顾了新中国成立前后我国由不能生产到生产出第一根无缝钢管直至发展成为世界第一大无缝钢管生产国的历史,详细介绍了我国无缝钢管重点生产厂鞍钢无缝钢管厂、攀钢集团成都无缝钢管有限责任公司、上海宝钢集团钢管分公司、天津钢管公司、包钢无缝钢管厂、衡阳钢管 (集团 )有限公司及大冶无缝钢管厂的设备及产品情况,探讨了我国无缝钢管生产今后发展的方向。     

废纸制浆造纸生产工艺和设备的优化与创新

介绍了有关欧美国家废纸的分类管理,并对加强中国废纸管理提出要求,及用普通废纸生产高质量文化用纸、特种纸的生产工艺和设备优化流程。     

空气分子污染探讨

介绍空气分子污染(AMC)的定义、国际标准AMC分级、国外污染物分类、洁净室AMC路径、AMC控制设施。     

Lot Acceptance and Compliance Testing Using the Sample Mean and an Extremum

In industry, one sometimes compares a sample mean and minimum, or a mean and maximum, to reference values to determine whether a lot should be accepted. Particularly prominent examples of such procedures are “Category B” sampling plans for checking the net contents of packaged goods. Because the exact joint distribution of an extremum and the mean of a sample is usually complicated, establishing these reference values using statistical considerations typically involves crude approximations or simulation, even under the assumption of normality. The purpose of this article is to use the saddlepoint method to develop a fairly simple and very accurate approximation to the joint cumulative distribution function (cdf) of the mean and an extremum of a normal sample. This approximation can be used to establish statistically based acceptance criteria or to evaluate the performance of sampling plans based on criteria derived in other ways. These uses are illustrated with examples.     

浅议钢塑排水管的种类及其性能对比探讨

目前,国内外排水管已大量采用钢塑管。本文就现况市场上的4种钢塑排水管的结构形式、性能及优缺点、连接方式进行了比较,供建设和设计单位参考。