Pervasive computing in mobile ad hoc networks requires that applications query their network environment for services and react to a plethora of events fired by other devices in that network responding to such queries...
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ISBN:
(纸本)9781605583648
Pervasive computing in mobile ad hoc networks requires that applications query their network environment for services and react to a plethora of events fired by other devices in that network responding to such queries. Current context-aware and event-driven architectures require the programmer to react to these events via a carefully crafted network of observers and event handlers, while inherently introducing complex concurrency issues. This paper proposes the integration of two techniques to solve these problems: ambient references and reactive programming. Ambient references are object-oriented communication abstractions that represent nearby remote objects in the mobile network and that make it possible to generate the events mentioned above. The reactive programming paradigm provides an abstraction over events such that the application can be written in a conventional programming style with explicit control flow. Copyright 2008 ACM.
Extensions to the actor model have been proposed to ease the development of mobile ad hoc applications. However, programming in the actor model is still difficult as it does not provide abstractions to synchronously c...
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ISBN:
(纸本)9781605583648
Extensions to the actor model have been proposed to ease the development of mobile ad hoc applications. However, programming in the actor model is still difficult as it does not provide abstractions to synchronously coordinate multiple actors. Thus, when programmers want to coordinate two or more actors they have to do it by hand. Additionally, programmers need to write failure recovery code for failures caused by the concurrent access to the actors they are using. Coding this manually is error prone and might even be not feasible. We propose a language abstraction based on software transactional memory to coordinate actors. We show that the integration of software transactional memory with the actor model makes writing failure recovery code superuous. Moreover, we show that our system even handles those cases where manually writing the failure recovery code is not feasible. Copyright 2008 ACM.
Let σ={σi | i ∈ I} be some partition of the set of all primes P. A set H of subgroups of G is said to be a complete Hall σ-set of G if every member ≠ 1 of H is a Hall σi-subgroup of G, for some i ∈ I, and H con...
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Let σ={σi | i ∈ I} be some partition of the set of all primes P. A set H of subgroups of G is said to be a complete Hall σ-set of G if every member ≠ 1 of H is a Hall σi-subgroup of G, for some i ∈ I, and H contains exactly one Hall σi-subgroup of G for every σi ∈σ(G). A subgroup H of G is said to be:σ-permutable or σ-quasinormal in G if G possesses a complete Hall σ-set H such that HAx= AxH for all A ∈ H and x ∈ G:σ-subnormal in G if there is a subgroup chain A = A0≤A1≤···≤ At = G such that either Ai-1■Ai or Ai/(Ai-1)Ai is a finite σi-group for some σi ∈σ for all i = 1,..., *** Mn < Mn-1 <···< M1 < M0 = G, where Mi is a maximal subgroup of Mi-1, i = 1, 2,..., n, then Mn is said to be an n-maximal subgroup of G. If each n-maximal subgroup of G is σ-subnormal(σ-quasinormal,respectively) in G but, in the case n > 1, some(n-1)-maximal subgroup is not σ-subnormal(not σ-quasinormal,respectively) in G, we write mσ(G)= n(mσq(G)= n, respectively).In this paper, we show that the parameters mσ(G) and mσq(G) make possible to bound the σ-nilpotent length lσ(G)(see below the definitions of the terms employed), the rank r(G) and the number |π(G)| of all distinct primes dividing the order |G| of a finite soluble group G. We also give the conditions under which a finite group is σ-soluble or σ-nilpotent, and describe the structure of a finite soluble group G in the case when mσ(G)=|π(G)|. Some known results are generalized.
The left context in LR-based parsing is the sequence of states in the parsing stack. The right context is the vocabulary strings to appear for a given left context. We propose an efficient method of computing right co...
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The left context in LR-based parsing is the sequence of states in the parsing stack. The right context is the vocabulary strings to appear for a given left context. We propose an efficient method of computing right context for LR-based syntax error repair. The efficiency of our method is achieved from removing some redundancies in the method of previous work.
We extend static filtering in [8], a query optimization strategy based on seminaive evaluation on system graphs, so that it can efficiently handle stratified programs without extra overhead. The computation of static ...
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We extend static filtering in [8], a query optimization strategy based on seminaive evaluation on system graphs, so that it can efficiently handle stratified programs without extra overhead. The computation of static filters is formalized as a transformation so that the least fixed point of the transformation can be the static filters. The static filtering on stratified programs is shown to be complete with respect to the iterated fixed point semantics.
A syntactic error repair model is proposed, and is defined as a partial function from strings to sentences. The replacement of a substring of a string with a substring of a sentence is described by a repair pattern, w...
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A syntactic error repair model is proposed, and is defined as a partial function from strings to sentences. The replacement of a substring of a string with a substring of a sentence is described by a repair pattern, which is roughly a pair of strings of grammar symbols. The model can be efficient with some restriction on repair patterns. An LR-based implementation of the model is discussed.
作者：
KIM, DHCHOE, KMProgramming Languages Laboratory
Department of Computer Science Korea Advanced Institute of Science and Technology 371-1 Kusong-Dong Yusang-Gu Taejon 305-701 South Korea
An efficient backward execution algorithm in the AND/OR Process Model for parallel evaluation of logic programs is proposed. The efficiency of the algorithm is achieved by means of information acquired during executio...
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An efficient backward execution algorithm in the AND/OR Process Model for parallel evaluation of logic programs is proposed. The efficiency of the algorithm is achieved by means of information acquired during execution of clauses. The algorithm is considered to be efficient in the sense that it issues fewer number of cancel messages and avoids unnecessary resetting operations. Furthermore, it performs independent redoing and resetting more concurrently than other related works.
Martin-Löf's type theory contains a logic, a specification language and a programming language, so it is a tool with different uses. Although it is traditionally used as an integrated programming logic, it ma...
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This paper is about specification and verification of processes, modelled as CCS-agents. We show, by means of examples that Hennessy-Milner Logic (HML) with recursion is a suitable language for expressing implicit or ...
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Text classification is an important task of assigning objects from a universe to two or more classes, especially classification is to classify the topic or the theme of a document. In this research, we have analyzed t...
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