面向产品生命周期的部分柔性技术选择

本文研究随机需求下产品生命周期不同阶段的部分柔性技术选择与生产能力规划问题。部分柔性技术是相对于完全柔性技术而言的,一种生产技术的柔性程度定义为能生产一产品类中产品个数多少的能力。不同柔性强度的生产技术,其投资成本和运行成本不同。本文首先建立了以计划期上总成本最小为目标的技术选择和生产能力规划模型,然后根据产品在其生命周期不同阶段的特点与市场需求的特点,应用所建立的模型进行仿真并总结产品导入期和成熟期技术选择的特点。     

国民性·怀疑与否定精神--鲁迅与道家文化片论之二

《鲁迅全集》中有四次提到《支那人气质》。可见,在鲁迅终其一生的关于中国国民性的思考、批判、重建和实践、选择之中,斯密司的《中国人气质》一书自始至终在其中都发挥着重要作用。阿Q所代表的中国国民性的核心就是“精神胜利法”,但这种“国民性”却并没有直接受到道家文化传统的影响,它是民间道教思维观念在日常生活中的衍化。鲁迅的怀疑与否定精神明显可见道家传统的影响,怀疑与否定精神本身并非只有消极、破坏的功能。从反面来看,正是怀疑与否定,才推动了积极、正面、建设的形成与发展。鲁迅经由与老庄道家非常接近的思路构建了“鲁迅式的沉默”世界,表现出他情感的丰厚博大。     

特指问表否定用法研究

疑问与否定两大范畴有一定的关联性。本文重点考察含疑问代词＂什么＂、＂谁＂、＂哪/哪儿/哪里＂等特指问表否定用法的相关类型,并总结出特指问表否定用法的产生机制及语用特点。本文认为这种否定用法是通过以疑问形式的语法结构为基础,由疑问代词本身、反问语气及语境合力产生的整体功能,其产生是以反问为机制的,表现了说话人的主观态度及感情色彩。     

英语语法"真""假"论

判断话语或言语的“真”与“假”有两条标准:一是依据客观事实;二是说写者意欲表达的信息。以此为主要依据,可以看出英语语法中的主谓一致、否定和时态所展示的不一致。主谓的不一致表现在谓语动词的数与结构的不一致和与意义的不一致;否定的“真”与“假”包含了否定的转移、形式的否定与意义的肯定以及结构的肯定与意义的否定;时态的讨论含盖了一般现在时表过去和将来时间,一般过去时表现在和将来时间以及SINCE从句、“假”主动态和“假”被动态等。     

Tuberculosis with relapse: A model

ABSTRACT

In a model of tuberculosis with relapse, the basic reproduction number R₀ includes new and relapse infections. Lyapunov functions help to prove that the global dynamic is completely determined by R₀. Replicated Latin hypercube sampling shows that early diagnosis and treatment are more efficient when relapse cases are considered.     

Dealing with omitted answers in a survey on social integration of immigrants in Italy

ABSTRACT

Surveys are used to infer the level of social integration of immigrants. Item response theory helps to describe the relationship among responses to test items and latent traits of interest. However, in the presence of nonignorable missing data, which are omitted responses depending on the latent traits to be measured, estimates of the model parameters are biased. To account for nonignorable missing data, the quantity and quality of contacts between immigrants and natives (so called “social integration”) are taken into account through a linear function of the response propensity. Higher education, no intention to migrate again, young age, Albanian nationality, and declaring a non-Muslim religion or none, comparatively favor social integration.     

Generalized Instrumental Variable Models

This paper develops characterizations of identified sets of structures and structural features for complete and incomplete models involving continuous or discrete variables. Multiple values of unobserved variables can be associated with particular combinations of observed variables. This can arise when there are multiple sources of heterogeneity, censored or discrete endogenous variables, or inequality restrictions on functions of observed and unobserved variables. The models generalize the class of incomplete instrumental variable (IV) models in which unobserved variables are single‐valued functions of observed variables. Thus the models are referred to as generalized IV (GIV) models, but there are important cases in which instrumental variable restrictions play no significant role. Building on a definition of observational equivalence for incomplete models the development uses results from random set theory that guarantee that the characterizations deliver sharp bounds, thereby dispensing with the need for case‐by‐case proofs of sharpness. The use of random sets defined on the space of unobserved variables allows identification analysis under mean and quantile independence restrictions on the distributions of unobserved variables conditional on exogenous variables as well as under a full independence restriction. The results are used to develop sharp bounds on the distribution of valuations in an incomplete model of English auctions, improving on the pointwise bounds available until now. Application of many of the results of the paper requires no familiarity with random set theory.     

英语否定结构几个值得注意的现象

英语中的否定结构十分复杂,它在很多方面与汉语的否定结构不完全对称,是英语语法体系的难点之一。本文主要从英汉两种语言对比的角度对英文否定结构中几个值得注意的现象进行了深入剖析,并通过具有代表性的例子使其更加直观地显现出来。     

逻辑递归性及其哲学思考

递归性是人的思维过程中普遍存在的动力机制。借助递归的思维路径,人们可以用简单的、自明的低层次要素描述、构造、说明复杂的整体,通过解决简单问题来解决复杂问题。递归问题丰富和补充了唯物辩证法关于事物联系和发展的否定之否定原理,并与复杂性科学和后现代主义哲学思潮密切相关,具有重要的理论意义     

话语理解中汉语隐性否定动词的框架转换及诱发机制研究

隐性否定是指一种形式肯定但意义否定的否定形式,这种否定在使用时没有句法层面上的否定标记,而是通过间接或者暗示的手段表达否定含义.本研究基于Jespersen对隐性否定动词所采用的划分方式,从中文语料库中选取四组隐性否定动词"避免"、"拒绝"、"否认"以及"怀疑"类,借助框架语义学相关理论,对它们在关键词激活环境下的框架转换现象进行研究.研究发现,在隐性否定的话语理解过程中,存在框架的转变,这一转变是由4个刺激条件(或诱发机制)引起的透视域的转变而引起的:语篇博弈效果;否定事件的主观否定性;事件表述的复杂性;隐性否定动词的语义内在矛盾性.该研究使我们认识到在实际语言交际中,话语使用者需要对语篇整体性进行思考,根据条件的变化而不断调整认知世界,以期实现语篇的正确理解,从而达到交际目的.