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1.
Kulpa  Zenon 《Reliable Computing》1997,3(3):209-217
The paper presents two-dimensional graphical representations for the space of intervals (the IS-diagram) and arrangement interval relations (the W-diagram). The usefulness of the representations is illustrated with the example of proving equivalence of different characterizations of convex interval relations.  相似文献   

2.
Actions and Events in Interval Temporal Logic   总被引:23,自引:0,他引:23  
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3.
Numerous temporal relations of verbal actions have been analysed in terms of various grammatical means of expressing verbal temporalisation such as tense, aspect, duration and iteration. Here the temporal relations within verb semantics, particularly ordered pairs of verb entailment, are studied using Allen's interval-based temporal formalism. Their application to the compositional visual definitions in our intelligent storytelling system, CONFUCIUS, is presented, including the representation of procedural events, achievement events and lexical causatives. In applying these methods we consider both language modalities and visual modalities since CONFUCIUS is a multimodal system.  相似文献   

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This paper explores a formalism for describing a wide class of multimedia document constraints, based on an interval temporal logic. We describe the requirements that arise from the multimedia documents application area, and we illustrate these requirements using several examples. Then we present the temporal logic formalism that we use. This logic extends existing interval temporal logic with a number of new features: actions, framing of actions, past operators, a projection-like operator called filter and a new handling of interval length. The notation is applied to the specification of the examples, and in particular a set of logical manipulations, providing feedback to an author, is presented. A model theory, logic and satisfaction relation are defined for the notation.  相似文献   

7.
刘婷  林闯  刘卫东 《计算机学报》2002,25(6):637-644
该文在扩展时段时序逻辑的基础上提出了一种推理机制,这种推理机制基于时间Petri网模型及基本不等式规则,可由一组已知的扩展时段时序关系推出一些未知的扩展时段时序关系,对不确定时间段内发生的事件及其相互关系具有较好的描述能力,这种推理机制的优势在于定性地对扩展时段之间的时序关系进行推理分析,利用时间Petri网模型,可以对复杂时序逻辑关系进行化简,比单纯利用不等式规则的推理更直观,也更简单,是一种行之有效的方法。  相似文献   

8.
Direction relations between extended spatial objects are important commonsense knowledge. Skiadopoulos proposed a formal model for representing direction relations between compound regions (the finite union of simple regions), known as SK-model. It perhaps is currently one of most cognitive plausible models for qualitative direction information, and has attracted interests from artificial intelligence and geographic information system. Originating from Allen first using composition table to process time interval constraints; composing has become the key technique in qualitative spatial reasoning to check the consistency. Due to the massive number of basic directions in SK-model, its composition becomes extraordinary complex. This paper proposed a novel algorithm for the composition. Basing the concepts of smallest rectangular directions and its original directions, it transforms the composition of basic cardinal direction relations into the composition of interval relations corresponding to Allen''s interval algebra. Comparing with existing methods, this algorithm has quite good dimensional extendibility, that is, it can be easily transferred to the tridimensional space with a few modifications.  相似文献   

9.
Temporal relation classification is one of contemporary demanding tasks of natural language processing. This task can be used in various applications such as question answering, summarization, and language specific information retrieval. In this paper, we propose an improved algorithm for classifying temporal relations, between events or between events and time, using support vector machines (SVM). Along with gold-standard corpus features, the proposed method aims at exploiting some useful automatically generated syntactic features to improve the accuracy of classification. Accordingly, a number of novel kernel functions are introduced and evaluated. Our evaluations clearly demonstrate that adding syntactic features results in a considerable improvement over the state-of-the-art method of classifying temporal relations.  相似文献   

10.
Various data mining methods have been developed last few years for hepatitis study using a large temporal and relational database given to the research community. In this work we introduce a novel temporal abstraction method to this study by detecting and exploiting temporal patterns and relations between events in viral hepatitis such as “event A slightly happened before event B and B simultaneously ended with event C”. We developed algorithms to first detect significant temporal patterns in temporal sequences and then to identify temporal relations between these temporal patterns. Many findings by data mining methods applied to transactions/graphs of temporal relations shown to be significant by physician evaluation and matching with published in Medline.  相似文献   

11.
时态表示和推理是人工智能领域的重要研究内容之一,它的应用范围分布很广,从逻辑基础研究到知识系统的应用。区间代数是一种独立的与领域无关的时态理论。用区间代数能表示不确定的时态关系,可以很方便的用于时态推理,表达能力强;时态关系的区间表示比较直观,可理解性强;同时区间代数可以进一步扩展到二维空间领域,即将区间代数拓展为矩阵代数,实现二维空间推理。在一维时态推理中,将时态的区间表示和矩阵表示相结合,在提高计算效率的同时,保持了形象直观的时态表示。  相似文献   

12.
林闯  刘婷  曲扬 《计算机学报》2001,24(12):1299-1309
针对点-时段时序逻辑的不足,提出了一种新的时段时序逻辑--扩展时段时序逻辑,对不确定时间段发生的事件具有较好的描述能力。时间Petri网模型表示的引入,增强了扩展时段时序逻辑的描述直观性及分析能力,为进行线性推理提供了有利的工具。同时还提出了几种变迁间的实施推理规则。运用这些规则可以简化复杂时序关系的Petri网模型,并在线性时间复杂度内定量地得到各变迁间的时序逻辑关系,因而是一种行这有效的方法。  相似文献   

13.
林闯  曲扬  李雅娟 《计算机学报》2002,25(12):1338-1347
给出了扩展时段时序逻辑的时间Petri网(TPN)模型构造方法,在构造模型的同时对时序关系进行一致性检验,在模型的基础上提出了一种时序关系推理算法,这种推理算法基于TPN模型的性质及基本不等式规则,可由一组已知的扩展时段时序关系推出一些未知的扩展时段时序关系,这种推广理算法的优势在于利用了TNP模型的分析技术,减小了推理的时间复杂度比单纯利用不等式规则的推理更直观,也更简单,是一种有效的方法,最后,对扩展时段时序逻辑的TPN模型进行了扩充,增强了其模型和分析的能力。  相似文献   

14.
近年来,越来越多的研究关注事件时序关系,但大多数工作集中于提高事件关系分类器的性能,忽略了分类器错误所造成的事件关系间不一致的问题。该文利用了一个全局优化的推理模型来解决这一问题,将事件时序关系全局优化看成整数线性规划问题,使用了自反性、传递性、同指性、时序连接词、事件类型对等多个约束条件。实验结果表明,该文的全局推理方法与分类器相比,F1值提高了3.56%。
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15.
定义区间互反判断矩阵的区间一致性指标,计算 n 维的平均随机区间一致性指标的值。提出区间互反判断矩阵满意一致性的新定义,给出一种新的区间互反判断矩阵满意一致性的检验方法,用算例验证新的满意一致性定义的有效性。  相似文献   

16.
Extended interval temporal logic (EITL), an extension of the traditional point-interval temporal logic (PITL), is proposed. In contrast to PITL that represents the dynamic aspects of deterministic intervals, EITL can model and reason about the temporal relations among nondeterministic intervals in discrete-event systems, in which the duration of an event is indeterminate and only the lower bound and upper bound of the ending time can be predicted in advance. Time Petri nets (TPNs) are used for modeling EITL, for they give a straightforward view of temporal relations between the extended intervals and also provide a number of theoretical and practical analysis methods. An inference engine based on the TPN modeling complemented with algebraic inequalities is proposed to construct an analytical representation of the EITL relations and solve qualitative temporal reasoning problems. Linear inference mechanism based on TPN reduction rules is used to infer new temporal relations and handle quantitative temporal reasoning problems with linear time complexity, as our example shows.  相似文献   

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18.
朱维军  周清雷 《计算机科学》2010,37(11):227-229
模型检测技术在实时系统验证中被广泛使用。离散时间区间时序逻辑满足性是可判定的,因而也是可模型检测的。连续时间域时间区间时序逻辑是否可模型检测,则并不清楚。约束时间域到非负实数,证明了其可满足性是不可判定的,但存在该逻辑的可判定子集,并发现了这样的子集。由于模型检测问题可归约为时序逻辑满足性判定问题,因此结果表明,时间区间时序逻辑不可模型检测,但其可判定子集可模型检测。  相似文献   

19.
Conventional plotting programs adopt techniques such as adaptive sampling to approximate, but not to guarantee, correctness and completeness in graphing functions. Moreover, implicitly defined mathematical relations can impose an even greater challenge as they either cannot be plotted directly, or otherwise are likely to be misrepresented. In this paper, we address these problems by investigating interval constraint plotting as an alternative approach that plots a hull of the specified curve. We present some empirical evidence that this hull property can be achieved by a algorithm. Practical experience shows that the hull obtained is the narrowest possible whenever the precision of the underlying floating-point arithmetic is adequate. We describe IASolver, a Java applet (http://www.cs.brandeis.edu/~tim) that serves as testbed for this idea.  相似文献   

20.
传统关联规则挖掘是在整个事务数据库的时间范围内进行的,但有时用户想得到某一特定时间范围(如商品的促销阶段)内的关联规则,该文对这一问题进行了详细讨论,提出了基于定制时间的时态支持度、时态频繁项集、时态置信度、时态关联规则等概念,在传统Apriori算法的基础上提出了挖掘时态频繁项集的算法。另一方面,讨论了当同时考虑正、负关联规则出现的矛盾规则问题以及用相关性解决这一问题的方法,提出了挖掘正负时态关联规则的算法,实例说明了算法的执行过程及有效性。  相似文献   

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