The Use of Situation Theory in Context Modeling

At the heart of natural language processing is the understanding of context dependent meanings. This paper presents a preliminary model of formal contexts based on situation theory. It also gives a worked‐out example to show the use of contexts in lifting, i.e., how propositions holding in a particular context transform when they are moved to another context. This is useful in NLP applications where preserving meaning is a desideratum.     

经典逻辑中的不确定性及其支持度

分析了经典逻辑中命题不确定性的存在性,提出了通过推理对命题不确定性的测度方法;详细描述了如何对原逻辑系统的扩展以建立具有不确定推理能力的新的逻辑系统URS;給出了URS的语法及语义,证明了URS的合理性与完全性定理,并与其它不确定推理方法作了比较.     

上下文一致性错误及其处理对应用的影响

在普适计算环境中,上下文信息由于受到噪声等不可控因素的干扰,面临着一致性错误的问题。这些错误会影响应用的正常运行,使其表现异常甚至失效。目前已经有自动的一致性错误处理方法来保障应用所获取的上下文满足数据层面的一致性约束,然而在数据层面保持一致是否能提升应用的运行质量并不明确。系统地研究了这个问题,并基于一组真实的上下文感知机器人小车应用,设计了一系列受控实验,来分析和比较在模拟和真实世界中上下文一致性错误的处理方式对应用运行质量的改善程度及潜在的负面影响。利用该实验的分析结果,将有助于提高普适计算中上下文感知应用的运行质量。     

The Liar, Context and Logical Form

This essay attempts to give substance to the claim that the liar'sparadox shows the truth predicate to be context sensitive. The aim ismodest: to provide an account of the truth predicate's contextsensitivity (1) that derives from a more general understanding ofcontext sensitivity, (2) that does not depend upon a hierarchy ofpredicates and (3) that is able to address the liar's paradox. Theconsequences of achieving this goal are not modest, though. Perhapssurprisingly, for reasons that will be discussed in the last section ofthis essay, a natural account of the truth predicate's contextsensitivity appears to lead naturally to a version of the correspondencetheory of truth according to which the truth predicate can be understoodas a relation holding between a sentence and a salient set of contexts.The plan of this essay is as follows. Section 1 contains a generalaccount of context sensitivity. The purpose of this section is toisolate certain features of context sensitivity and formal methods oftreating them, which we will then apply to the truth predicate. Section 2then outlines two minimal conditions to be satisfied by a truthpredicate. In Section 3, I present a version of the liar paradoxthat results from these conditions and the assumption that the truthpredicate is not context sensitive in the sense described in sectionone. Finally, in section four, I provide what appear to be naturalconsequences of a truth predicate's context sensitivity. Section 4 isadmittedly speculative and points in the direction for future research.     

A Historical View of Context

This paper examines a number of the approaches, origins and ideals of context-aware systems design, looking particularly at the way that history influences what we do in our ongoing activity. As a number of sociologists and philosophers have pointed out, past social interaction, as well as past use of the heterogeneous mix of media, tools and artifacts that we use in our everyday activity, influence our ongoing interaction with the people and media at hand. We suggest that ones experience and history is thus part of ones current context, with patterns of use temporally and subjectively combining and interconnecting different media as well as different modes of use of those media. One such mode of use is transparent use, put forward by Weiser as ubicomps design ideal. One theoretical finding is that this design ideal is unachievable or incomplete because transparent and more focused analytical use are interdependent, affecting and feeding into each other through ones experience and history. Using these theoretical points, we discuss a number of context-aware system designs that make good use of history in supporting ongoing user activity.     

常州城市古建筑的传统文脉研究

本篇是从相对微观的角度去了解常州城市建筑的历史文脉,从而给予正在加快拆建中的常州城市建设的过程中应注意的建筑特色和文脉方面提供资料。在此不是要去批判现状,而是要在城市发展到一定的必要阶段,通过对常州传统建筑文脉的研究,理出思路,让城市文脉得以延续。     

命题逻辑等值演算的计算机实现

本文针对等值演算理论,通过数据结构和C 程序设计语言,分析了命题公式的逻辑结构,设计出用广义表单链表的存储结构,并在此基础上探讨了如何实现其基本操作,从而进一步阐明了复杂等值演算的计算机实现算法.     

语义信息集成中上下文仲裁器的设计与实现

已有的基于模式映射的语义信息集成能够解决分布数据源之间的模式异构,对于普遍存在的上下文异构则无法解决.首先提出一种将暗含的上下文语义进行形式化描述的方法,然后在基于模式映射的语义信息集成基础上,增加上下文仲裁器以自动检测和解决上下文异构.详细介绍了上下文仲裁器的工作原理、设计思想与实现细节.     

基于布尔语义的Gentzen推导模型

布尔模型是信息检索系统的一种基础模型。给出了命题逻辑和布尔代数间的一种新的对应关系,其中布尔代数中的不等式对应Gentzen系统中的矢列式,使得当一个不等式在任意布尔代数中为真,当且仅当它所对应的矢列式是可证的。并且使得在信息检索中,针对信息的推理可以有效地转为偏序集上的运算。讨论的命题逻辑语言的运算符为、ù、ú;并且定义了项(a|t|t1ùt2|t1út2其中a是一个元素)来替代原先的公式和表示布尔代数中的元素。此外,定义了以布尔代数为论域的赋值v,将命题逻辑中的项赋值为布尔代数中的元素,并且如果tΔΓt vtΔΔt v,则矢列式ΓT D为真。最后给出了Gentzen系统下的可靠性和完备性定理的证明。     

汉语音节→汉字转换中的动态语境学习

本文从语言使用的局部性原理出发，引入动态语境网的概念，提出了在汉语音节→汉字转换中的动态语境学习方法，有效地提高了音节汉字的转换正确率。     

基于时、频域上下文模型的图像压缩算法

结合离散小波变换和基于上下文的自适应算术编码方法，提出了一种基于时、频域上下文预测模型的图像压缩算法．它通过分析在不同子带内的小波系数和同一子带内的小波系数之间的相关性，建立一个时、频域的上下文预测模型，并通过对增加的条件熵的分析，合理地对该模型中的上下文进行量化，得到合适的编码上下文用于自适应的算术编码以降低模型开销．与此同时，这种算法的输出码流是嵌入式的，可以很好的满足渐进式的传输需求．试验结果表明，该算法在各种压缩比下都获得了比JPEG2000要好的压缩效果．     

Distributed Context Retrieval and Consistency Control in Pervasive Computing

The challenge of saturating all phases of pervasive service provision with context-aware functionality lies in coping with the complexity of maintaining, retrieving and distributing context information. To efficiently represent and query context information a sophisticated modelling scheme should exist. To distribute and synchronise context knowledge in various context repositories across a multitude of administrative domains, streamlined mechanisms are needed. This paper elaborates on an innovative context management framework that has been designed to cope with free-text and location based context retrieval and efficient context consistency control. The proposed framework has been incorporated in a multi-functional pervasive services platform, while most of the mechanisms it employs have been empirically evaluated.     

决策形势背景的命题推演

在形势背景的基础上,通过弱化形式概念构成的条件,定义了比形式概念更为广泛的认知基本单位,即命题。基于一些基本概念如必然命题和充分命题,给出了命题的一些相关性质及各种命题间的关系,以及获取一些新命题的有效方式。通过确定一个命题的程度即确定度,探讨了基于决策形式背景中的命题推理方法,为形势背景上的不确定推理提供了一种新的认知框架。     

运用云模型评价复合网络情境的方法研究

由于网络的开放性、动态性、难控性等特征,网络情境参数的取值及其变化表现出模糊性、随机性等不确定特征,对Internet中软件系统的运行和管理具有重要的影响。在对实际网络应用需求分析的基础上,利用云模型在定性概念与定量数值之间转换的优点,研究了一种基于云模型的复合网络情境评价机制。它对多维网络情境因素的特征进行了刻画,能够实现多维情境参数与运行时网络环境评估之间的量化映射,较好地处理情境参数的不确定性和模糊性;通过加入用户误差承受度,动态调整样本数量,使建模结果更为稳定和准确;实现了在参数级和群体级两个粒度的网络情境参数特征建模,较好地表征了网络情境的整体评价,有助于避免配置抖动问题。该方法的效果通过系列仿真实验得到了验证。     

基于面本体的情境搜索研究

为了将用户的搜索过程与用户当前情境相关联,提出一种基于面本体的情境搜索模型(Faceted Ontology-based Context Search,FOCS)。FOCS根据情境本体对用户输入的关键字进行语义扩展,生成相应的搜索本体。通过面本体标注各类异构文档,利用洪泛相似度算法进行搜索本体与面本体的本体匹配,实现情境搜索。实验结果表明,提出的方法应用于搜索引擎,与传统的信息搜索比较,具有更好的查全率与查准率。     

Implicit Epistemic Aspects of Constructive Logic

In the present paper I wish to regard constructivelogic as a self-contained system for the treatment ofepistemological issues; the explanations of theconstructivist logical notions are cast in anepistemological mold already from the outset. Thediscussion offered here intends to make explicit thisimplicit epistemic character of constructivism.Particular attention will be given to the intendedinterpretation laid down by Heyting. This interpretation, especially as refined in the type-theoretical work of Per Martin-Löf, puts thesystem on par with the early efforts of Frege andWhitehead-Russell. This quite recent work, however,has proved valuable not only in the philosophy andfoundations of mathematics, but has also foundpractical application in computer science, where thelanguage of constructivism serves as an implementableprogramming language, and within the philosophy oflanguage.\footnote{Nordstr\"{o}m et al. (1990) give an overview of the work in computerscience, whereas Ranta (1995) provides an impressiveconstructivist alternative to Montague Grammar usingthe richer type structure of Martin-L\"{o}f in placeof the simple classical type theory of Church.} Mypresentation will be carried out through a contrastwith standard metamathematical work.\footnote{Troelstra and van Dalen (1988) give an encyclopedictreatment of the metamathematics of constructivism.}In the course of the development I have occasion tooffer some novel considerations (in Sections~6 and 8) on thenature of proof and inference(-acts).     

Context and its representation

Recent work in HCI has argued that an adequate account of computer use and the user's understandings should pay attention to the contexts in which interactions take place. The paper reaffirms this claim and distinguishes some variants of it, but simultaneously argues that the specification of what is to count as ‘context’ is more problematic than is often supposed. Some empirical data in the form of a transcribed videotape of one interaction is discussed to illustrate the argument. Finally some implications for HCI are briefly considered.     

形式背景下的技能约简与评估

知识空间理论(KST)为构建知识评价体系提供了有效的途径.形式概念分析(FCA)是知识发现的有力工具.知识空间理论与形式概念分析间存在密不可分的联系.知识空间理论被运用于评估学习者的知识和指导未来的学习.目前,如何构建准确的知识结构是知识空间理论的重点研究问题.基于技能与问题间的关系,对知识空间理论与形式概念分析间的联...