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This paper presents a parallel logic programming language named P-Prolog which is being developed as a logic programming language featuring both and- and or-parallelism. Compared with the other parallel logic programming languages, syntactic constructs such as read-only annotation,6) mode declaration2) and communication constraints7) are not used in P-Prolog. A new concept introduced in P-Prolog is the exclusive relation of guarded Horn clauses. Advances included in P-prolog. are:
  1. The synchronization mechanism can determine the direction of data flow dynamically.
  2. Guarded Horn clauses can be interpreted as eitherdon’t care nondeterminism ordon’t know non-determinism.
A prototype interpreter of P-Prolog has been implemented in C-Prolog. We are now implementing a P-Prolog interpreter in the C language.  相似文献   

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Stable semantics for disjunctive programs   总被引:1,自引:0,他引:1  
We introduce the stable model semantics fordisjunctive logic programs and deductive databases, which generalizes the stable model semantics, defined earlier for normal (i.e., non-disjunctive) programs. Depending on whether only total (2-valued) or all partial (3-valued) models are used we obtain thedisjunctive stable semantics or thepartial disjunctive stable semantics, respectively. The proposed semantics are shown to have the following properties:
  • ? For normal programs, the disjunctive (respectively, partial disjunctive) stable semantics coincides with thestable (respectively,partial stable) semantics.
  • ? For normal programs, the partial disjunctive stable semantics also coincides with thewell-founded semantics.
  • ? For locally stratified disjunctive programs both (total and partial) disjunctive stable semantics coincide with theperfect model semantics.
  • ? The partial disjunctive stable semantics can be generalized to the class ofall disjunctive logic programs.
  • ? Both (total and partial) disjunctive stable semantics can be naturally extended to a broader class of disjunctive programs that permit the use ofclassical negation.
  • ? After translation of the programP into a suitable autoepistemic theory \( \hat P \) the disjunctive (respectively, partial disjunctive) stable semantics ofP coincides with the autoepistemic (respectively, 3-valued autoepistemic) semantics of \( \hat P \) .
  •   相似文献   

    5.
    A DIN Kernel LISP Draft (DKLisp) has been developed by DIN as Reaction to Action D1 (N79), short term goal, of ISO WG16. It defines a subset language, as compatible as possible with the ANSICommon-Lisp draft, but also with theEuLisp draft. It combines the most important LISP main stream features in a single, compact, but nevertheless complete language definition, which thereby could be well suited as basis for a short term InternationalLisp Standard. Besides the functional and knowledge processing features, the expressive power of the language is well comparable with contemporary procedural languages, as e.g. C++ (of course without libraries). Important features ofDKLisp are:
  • to be a “Lisp-1,” but allowing an easy “Lisp-2” transformation;
  • to be a simple, powerful and standardized educationalLisp;
  • to omit all features, which are unclean or in heavy discussion;
  • DKLisp programs run nearly unchanged inCommon-Lisp;
  • DKLisp contains a simple object and package system;
  • DKLisp contains those data classes and control structures also common to most modernLisp and non-Lisp languages;
  • DKLisp offers a simple stream I/O;
  • DKLisp contains a clean unified hierarchical class/type system;
  • DKLisp contains the typical “Lisp-features” in an orthogonal way;
  • DKLisp allows and encourages really small but powerful implementations;
  • DKLisp comes in levels, so allowing ANSICommon-Lisp to be an extension ofDKLisp level-1.
  • The present is the second version of the proposal, namely version 1.2, with slight differences with respect to the one sent to ISO. Sources of such changes were the remarks generously sent by many readers of the previous attempt.  相似文献   

    6.
    We settle all relativized questions of the relationships between the following five propositions:
    • P = NP.
    • P = UP.
    • P = NP $\cap$ coNP.
    • All disjoint pairs of NP sets are P-separable.
    • All disjoint pairs of coNP sets are P-separable.
    We make the first widespread use of variations of generic oracles to achieve the necessary relativized worlds.  相似文献   

    7.
    The need to design and verify architectures to support parallel implementations of declarative languages has led to the development of a novel language, called Paragon, which bridges the gap between the top-level specification of the abstract machine, and its detailed implementation in terms of parallel processes and message passing. The central technical contributions in this paper are:
  • ? The introduction and specification of Paragon, a parallel object-oriented language based on graph rewriting and message passing principles.
  • ? An illustration of the approach at work in the design of a parallel supercombinator graph reduction machine.
  • ? A sketch proof that this design meets the requirements statement.
  •   相似文献   

    8.
    The main contribution of the present article consists of new 3D parallel and symmetric thinning schemes which have the following qualities:
  • They are effective and sound, in the sense that they are guaranteed to preserve topology. This guarantee is obtained thanks to a theorem on critical kernels;
  • They are powerful, in the sense that they remove more points, in one iteration, than any other symmetric parallel thinning scheme;
  • They are versatile, as conditions for the preservation of geometrical features (e.g., curve extremities or surface borders) are independent of those accounting for topology preservation;
  • They are efficient: we provide in this article a small set of masks, acting in the grid ?3, that is sufficient, in addition to the classical simple point test, to straightforwardly implement them.
  •   相似文献   

    9.
    This paper presents a kernel language KLND on the basis of analysing the kernel languagerequirements of new generation computer systems. These requirements are: the ability ofknow-ledge processing, the parallelism, the elegant mathematical properties of the comput-ation model which is appropriate for working as the basis of the novel architecture design, andthe suitability for writing large scale softwares. The main features of KLND are as follows: 1. several new language concepts. 2. the modularity, 3. the unification of logical and functional programming styles, 4. the exploitation of the parallelism. 5. the introduction of the type concept, 6. the introduction of the storage concept.  相似文献   

    10.
    In this paper, for a finitely generated monoid M, we tackle the following three questions:
    1. Is it possible to give a characterization of rational subsets of M which have polynomial growth?
    2. What is the structure of the counting function of rational sets which have polynomial growth?
    3. Is it true that every rational subset of M has either exponential growth or it has polynomial growth? Can one decide for a given rational set which of the two options holds?
    We give a positive answer to all the previous questions in the case that M is a direct product of free monoids. Some of the proved results also extend to trace monoid.  相似文献   

    11.
    We propose a technique for handling recursive axioms in deductive databases. More precisely, we solve the following problem: Given a relational query including virtual relations defined from axioms (Horn clauses, with variables in the conclusion predefined in the hypotheses), which can be recursive, how to translate this query into arelational program, i. e. a set of relational operations concerning only real relations (not virtual). Our solution has the following properties:
  • ? the program to evaluate the query always terminates,
  • ? the relational program is produced by a pure compilation of a source query and of the axioms, and is independent of the data values (there is no run-time),
  • ? the relational operations are optimized: theyfocus towards the computation of the query, without needless computations.
  • As far as we know, the Alexander Method is the first solution exhibiting all these properties. This work is partly funded by Esprit Project 112 (KIMS).  相似文献   

    12.
    The general specifications and design for a High-Speed General Information Management System, HSGIMS, to serve as the basis for a Global Information Network are given. Some of the key specifications that have been confirmed in experiments with a prototype of the HSGIMS are:
    1. Information (or data) and Question-type (or logical data) independence.
    2. Very small bounded search times that are independent of the amount of information that is managed and can be computed exactly.
    3. A fool-proof security system that can be used to protect databases against viruses and can also be easily invoked to deny unauthorized access by users.
    4. Efficient use of all storage and communications resources.
      相似文献   

    13.
    Inventive Machine project is the matter of discussion. The project aims to develop a family of AI systems for intelligent support of all stages of engineering design. Peculiarities of the IM project:
    1. deep and comprehensive knowledge base — the theory of inventive problem solving (TIPS)
    2. solving complex problems at the level of inventions
    3. application in any area of engineering
    4. structural prediction of engineering system development
    The systems of the second generation are described in detail  相似文献   

    14.
    RaumComputer     
    The RoomComputer is an embedded system and as such offers unprecedented chances to manage buildings. Several RoomComputers can be networked via the Intra-/Internet, which makes it possible to monitor, control, and manage rooms and buildings on a unified worldwide accessible platform, irrespective of any particular local technology. It can be easily installed in any building and gives access to a full set of services. It implements a distributed system, which provides secure and controlled access to services like
    1. control of light, heating, ventilation, air and climate
    2. communication facilities like unified messaging, telephone, fax, etc.
    3. reservation of rooms and required resources
    4. localization of persons and equipment within rooms and buildings
    5. entrance control (i.e. locking/unlocking doors)
    6. organization of maintenance and house keeping, and
    7. charging and billing.
      相似文献   

    15.
    We sketch a method for deduction-oriented software and system development. The method incorporates formal machine-supported specification and verification as activities in software and systems development. We describe experiences in applying this method. These experiences have been gained by using the LP, the Larch proof assistant, as a tool for a number of small and medium size case studies for the formal development of software and systems. LP is used for the verification of the development steps. These case studies include
  • ? quicksort
  • ? the majority vote problem
  • ? code generation by a compiler and its correctness
  • ? an interactive queue and its refinement into a network.
  • The developments range over levels of requirement specifications, designs and abstract implementations. The main issues are questions of a development method and how to make good use of a formal tool like LP in a goal-directed way within the development. We further discuss the value of advanced specification techniques, most of which are deliberately not supported by LP and its notation, and their significance in development, Furthermore, we discuss issues of enhancement of a support system like LP and the value and the practicability of using formal techniques such as specification and verification in the development process in practice.  相似文献   

    16.
    There are many expert systems that use experimental knowledge for diagnostic analysis and design. However, there are two problems for systems using only experiential knowledge:
    1. unexpected problems cannot be solved and
    2. acquiring experiential knowledge from human experts is difficult.
    To solve these problems, general principles or basic knowledge must be added to expert systems in addition to the experimental knowledge. In response, we previously proposed Qupras (Qualitative physical reasoning system) as a framework for basic knowledge. This system has two knowledge representations, one related to physical laws and the other to objects. By using this knowledge, Qupras reasons about the relations among physical objects, and predicts the next state of a physical phenomenon. Recently, we have improved some of Qupras’ features, and this pater desctibes the following main enhancements:
    1. inheritance for representation of objects,
    2. new primitive representations to describe discontinuous change, and
    3. control features for effective reasoning.
      相似文献   

    17.
    The application of glass in the microsystems technology becomes more and more important. Therefore, it is necessary to combine special microstrutturable glasses with various other materials (e.g. joining with silicon by anodic bonding, joining with metals by electroforming, joining with polymers by glueing, joining with various other glasses by brazing or diffusion welding). In order to increase the use of glass in the microsystems technology especially four fields of research are important:
  • -development of special glasses with various properties
  • -technologies of microstructuring
  • -technologies of joining
  • -application
  • These four topics are main research fields performed at the Institute of Glass/Ceramics-Technology and will be described in this paper.  相似文献   

    18.
    Applications in the automobile sector, wired or unwired, are today often integrated into a network of sensors and actors as well as in service functions, visualization, and entertainment. The paper presents an innovative platform, which is applicable for automotive and automation applications. & IT systems for automobiles and for business applications took a very different development direction.
  • ? In the automotive sector a lot of proprietary IT systems have been developed.
  • ? The increasing requirements of automotive applications require platform concepts, which are based on open standards.
  •   相似文献   

    19.
    In this paper, we examine the state of software engineering (SE) research from the point of view of the following research questions:
    • 1.What topics do SE researchers address?
    • 2.What research approaches do SE researchers use?
    • 3.What research methods do SE researchers use?
    • 4.On what reference disciplines does SE research depend?
    • 5.At what levels of analysis do SE researchers conduct research?
    To answer those questions, we examined 369 papers in six leading research journals in the SE field, answering those research questions for each paper.From that examination, we conclude that SE research is diverse regarding topic, narrow regarding research approach and method, inwardly-focused regarding reference discipline, and technically focused (as opposed to behaviorally focused) regarding level of analysis.We pass no judgment on the SE field as a result of these findings. Instead, we present them as groundwork for future SE research efforts.  相似文献   

    20.
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