首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11篇
  国内免费   3篇
  完全免费   2篇
  自动化技术   16篇
  2010年   2篇
  2004年   1篇
  2001年   2篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
排序方式: 共有16条查询结果,搜索用时 171 毫秒
1.
冯冼  冯建湘  徐建文 《计算机工程》2010,36(11):221-222,225
介绍一种采用信令网关构建大容量自动外呼系统的设计过程及关键技术。该过程包括系统的硬件架构、软件系统设计。关键技术包括设备控制、呼叫调度与管理、大批量号码存取等。与已有的电话外呼系统相比,该系统具有容量大、效率高、成本低、易于维护等特点。应用结果表明,该系统运行稳定可靠,具有较高的推广应用价值。  相似文献
2.
事务是由一组数据库操作序列组成的,具有ACID特性。然而,在大规模分布式应用环境下,传统的事务模型是不适用的。基于本地封闭世界假设,结合数据复制技术,提出一种基于本地封闭世界假设的分布式事务模型,阐述该事务模型的特点、并发控制策略,给出该事务模型的正确性证明,并用一个简化的教学管理系统说明该事务模型。  相似文献
3.
We propose criteria that any rule for inferring negative information from disjunctive databases should satisfy, and examine existing rules from this viewpoint. We then present a new inference rule, the ‘disjunctive database rule’ (DDR), and compare it to the existing rules with respect to the criteria. In particular, the DDR is equivalent to the CWA for definite databases, it infers no more negative information than the GCWA, and it interprets disjunction inclusively rather than exclusively. We generalize the DDR to a class of layered databases, describe an implementation of the DDR, ‘negation as positive failure’, and study its soundness and completeness properties.  相似文献
4.
Explicit representation of negative information in logic programs is not feasible in many applications such as deductive databases and artificial intelligence. Defining default rules which allow implicit inference of negated facts from positive information encoded in a logic program has been an attractive alternative to the explicit representation approach. There is, however, a difficulty associated with implicit default rules. Default rules such as the CWA and the GCWA, which closely model logical negation, are in general computationally intractable. This has led to the development of weaker definitions of negation such as the Negation-As-Failure (NF) and the Support-For-Negation (SN) rules which are computationally simpler. These are sound implementations of the CWA and the GCWA, respectively. In this paper, we define an alternative rule of negation based upon the fixpoint definition of the GCWA. This rule, called the Weak Generalized Closed World Assumption (WGCWA), is a weaker definition of the GCWA that allows us to implement a sound negation rule, called the Negation-As-Finite-Failure (NAFF), similar to the NF-rule and less cumbersome than the SN-rule. We present three definitions of the NAFF. Two declarative definitions similar to those for the NF-rule and one procedural definition based on SLI-resolution.  相似文献
5.
This paper extends Reiter’s closed world assumption to cases where the assumption is applied in a precedence order between predicates. The extended assumptions are: thepartial closed world assumption, thehierarchical closed world assumption and thestepwise closed world assumption. The paper also defines an extension of Horn formulas and shows several consistency results about the theory obtained from the extended Horn formulas by applying the proposed assumptions. In particular, the paper shows that both the hierarchical closed world assumption and the stepwise closed world assumption characterize the perfect model of stratified programs.  相似文献
6.
We address the problem of a consistent fixpoint semantics for general disjunctive programs restricted to stratifiable programs which do not recurse through negative literals. We apply the nonmonotonic fixpoint theory developed by Apt, Blair and Walker to a closure operatorT c and develop a fixpoint semantics for stratified disjunctive programs. We also provide an iterative definition for negation, called the Generalized Closed World Assumption for Stratified programs (GCWAS), and show that our semantics captures this definition. We develop a model-theoretic semantics for stratified disjunctive programs and show that the least state characterized by the fixpoint semantics corresponds to a stable-state defined in a manner similar to the stable-models of Gelfond and Lifschitz. We also discuss a weaker stratification semantics for general disjunctive programs based on the Weak Generalized Closed World Assumption.  相似文献
7.
This article argues that: (i) Defeasible reasoning is the use of distinctive procedures for belief revision when new evidence or new authoritative judgment is interpolated into a system of beliefs about an application domain. (ii) These procedures can be explicated and implemented using standard higher-order logic combined with epistemic assumptions about the system of beliefs. The procedures mentioned in (i) depend on the explication in (ii), which is largely described in terms of a Prolog program, EVID, which implements a system for interactive, defeasible reasoning when combined with an application knowledge base. It is shown that defeasible reasoning depends on a meta-level Closed World Assumption applied to the relationship between supporting evidence and a defeasible conclusion based on this evidence. Thesis (i) is then further defended by showing that the EVID explication of defeasible reasoning has sufficient representational power to cover a wide variety of practical applications of defeasible reasoning, especially in the context of decision making.  相似文献
8.
9.
In this paper, we study a new semantics of logic programming and deductive databases. Thepossible model semantics is introduced as a declarative semantics of disjunctive logic programs. The possible model semantics is an alternative theoretical framework to the classical minimal model semantics and provides a flexible inference mechanism for inferring negation in disjunctive logic programs. We also present a proof procedure for the possible model semantics and show that the possible model semantics has an advantage from the computational complexity point of view.This is a revised and extended version of the paper [36] which was presented at the Tenth International Conference on Logic Programming, Budapest, 21–25 June 1993.  相似文献
10.
姜云飞 《计算机学报》1995,18(7):517-522
本文提出了L集合的概念以及一种新的使用L集合的一阶数据库询问求值方法。因为这种方法对原数据库只增加一个新字句,所以询问求值的效率大为提高,而且因为可以直接使用L集合回答对数据库的询问,求值过程比较简单。  相似文献
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号