Visual Prolog语言在测试设备故障诊断专家系统中的应用

Visual Prolog语言是人工智能与专家系统领域最著名的逻辑程序设计语言,适合表达人的思维和推理规则,能够方便地实现模式匹配、回溯、事实数据库和谓词等功能;针对导弹测试设备结构复杂、故障隔离与定位困难等情况,充分利用Visual Prolog语言在专家系统知识表示及逻辑推理过程中的优点,建立了一个基于规则的导弹测试设备故障诊断专家系统;通过应用表明Visual Prolog语言十分适合构建此类专家系统,并具有良好的开发应用前景.     

Pattern-matching spi-calculus

Cryptographic protocols often make use of nested cryptographic primitives, for example signed message digests, or encrypted signed messages. Gordon and Jeffrey’s prior work on types for authenticity did not allow for such nested cryptography. In this work, we present the pattern-matching spi-calculus, which is an obvious extension of the spi-calculus to include pattern-matching as primitive. The novelty of the language is in the accompanying type system, which uses the same language of patterns to describe complex data dependencies which cannot be described using prior type systems. We show that any appropriately typed process is guaranteed to satisfy robust authenticity, secrecy and integrity properties.     

P#: a concurrent Prolog for the .NET framework

We discuss P#, our implementation of a tool that allows interoperation between a concurrent superset of the Prolog programming language and C#. This enables Prolog to be used as a native implementation language for Microsoft's .NET platform. P# compiles a linear logic extension of Prolog to C# source code. We can thus create C# objects from Prolog and use C#'s graphical, networking and other libraries. We add language constructs on the Prolog side that allow concurrent Prolog code to be written. A primitive predicate is provided that evaluates a Prolog structure on a newly forked thread. Communication between threads is based on the unification of variables contained in such a structure. It is also possible for threads to communicate through a globally accessible table. All of the new features are available to the programmer through new built-in Prolog predicates. We discuss two software engineering tools implemented using P#. Copyright © 2004 John Wiley & Sons, Ltd.     

Automatic generation of MPEG test streams from high-level grammars

This paper describes a technique to generate complex, moving picture experts group (MPEG) data streams containing packets which range through a selected set of variants, as allowed by the grammar of the packet stream. The Prolog logic programming language has been used, whose declarative power allows data generation almost directly from the grammar, i.e. without the need for explicitly programming a grammar traversal mechanism as would be the case with an imperative language. A reasonably declarative style of grammar and variation definition is achieved, and at the same time, a reasonably efficient generation process. The basic idea is to use a declarative fragment of Prolog for the grammar, but to use imperative features of Prolog for matters like packet enumeration and packet payload generation. Generation of test data from grammars is not new, nor is the use of Prolog programs for generation of test data, but as far as we know, the combination of both has not reported on in the literature, nor its application to MPEG demultiplexers/decoders.     

用于网络入侵检测的模式匹配新方法

针对新一代网络入侵检测系统(NIDS)的创建需要先进的模式匹配引擎,提出一种模式匹配的新方案,利用基于硬件的可编程状态机技术(B-FSM)来实现确定性处理过程。该技术可以在一个输入流中同时获取大量模式,并高效地映射成转换规则。通过对网络入侵检测系统中普遍采用的规则集(Snort)进行实验,实验结果表明该方法具有存储高效、执行速度快、动态可更新等特点,可以满足NIDS的需要。     

目标独立的Prolog程序路径依赖分析语义

在Prolog程序分析中,考虑程序的执行路径和非逻辑的cut操作可提高程序分析的精度.当前用于Prolog程序路径依赖分析的语义因依赖于程序执行的目标而不适合目标独立的程序分析.为此,本文采用了一种携带路径信息并允许cut操作的Prolog抽象语法,在此基础上给出了Prolog的操作语义和一种目标独立的标号树(LT)语文,并证明了LT语义相对于操作语义的正确性.LT语义可作为目标独立的Prolog程序路径依赖分析的基础.     

Rotation-invariant pattern matching with color ring-projection

In this paper, we propose a rotation-invariant pattern-matching scheme for detecting objects in complex color images. The complexity and computational load for matching colored objects in arbitrary orientations are reduced significantly by the 1-D color ring-projection representation. It can rapidly select the possible locations of a reference template in the input scene by computing the normalized correlation of 1-D color ring-projection patterns. Objects in the candidate locations are then verified by the pixel-to-pixel template matching. To make the pixel-based matching invariant to rotation, a color feature is used as pixel density, and the axis of least second moment is employed to estimate the rotational angle of a colored pattern. The proposed method has shown promising result based on experiments on a variety of natural and industrial images.     

Implementation of tabled evaluation with delaying in Prolog

Unlike SLD resolution as implemented in Prolog, tabled evaluation with delaying guarantees termination for function free logic programs, avoids repeated computation of identical subqueries, and handles recursion through negation. It is often used in query processing and nonmonotonic reasoning where termination is required. The paper presents a new technique for incorporating tabled evaluation into existing Prolog systems. It requires neither time consuming modifications of a Prolog engine nor metainterpretation that can enormously slow down program execution. Instead, using a program transformation approach, the technique allows effective use of the advanced Prolog technology. The transformed program uses tabling primitives implemented externally in C that provide direct control over the search strategies. This brings efficiency as well as portability across Prolog systems. Experiences with a prototype implementation indicate that the approach results in a flexible and pragmatic method for query processing and nonmonotonic reasoning on top of Prolog. Performance measurements show that the method is efficient for practical applications     

An experiment in modeling human visual learning

This paper describes an experiment that was conducted for the purpose of modeling human learning of visual patterns. A simple visual pattern game, called Merlin, was used as the vehicle for this experiment as it exhibits a feature known as non-serializable subgoals and, as such, is somewhat difficult to master. While subjects played a computerized version of the game, their moves and times between moves were recorded by a computer. Each subject was also asked to keep a written record of the strategies they discovered while playing the game. Finally, after the subjects declared that they had mastered the game, they were interviewed and asked to describe their overall strategies.Programs were then written in Prolog that attempted to model the processes that human subjects used to master the game. The purpose of constructing these “machine learning” programs was to gain insight into the ways that learning (especially visual pattern learning) is actually accomplished by human beings.Four parallels between human learning and machine learning were examined: (1) the use of macro strategies; (2) the simplification of the search space by using rotations and reflections; (3) the recognition of symmetrical board positions; and (4) improvement with practice.     

A prolog technology theorem prover: Implementation by an extended prolog compiler

A Prolog technology theorem prover (PTTP) is an extension of Prolog that is complete for the full first-order predicate calculus. It differs from Prolog in its use of unification with the occurs check for soundness, the model-elimination reduction rule that is added to Prolog inferences to make the inference system complete, and depth-first iterative-deepening search instead of unbounded depthfirst search to make the search strategy complete. A Prolog technology theorem prover has been implemented by an extended Prolog-to-LISP compiler that supports these additional features. It is capable of proving theorems in the full first-order predicate calculus at a rate of thousands of inferences per second.This is a revised and expanded version of a paper presented at the 8th International Conference on Automated Deduction, Oxford, England, July 1986.This research was supported by the Defense Advanced Research Projects Agency under Contract N00039-84-K-0078 with the Naval Electronic Systems Command and by the National Science Foundation under Grant CCR-8611116. The views and conclusions contained herein are those of the author and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the Defense Advanced Research Projects Agency, the National Science Foundation, or the United States government. Approved for public release. Distribution unlimited.     

Man-machine communication in Portuguese: A friendly library service system

This paper enhances some of the main aspects of a system which converses in Portuguese to provide a library service covering the field of Artificial Intelligence. Its central feature is the use of logic as a single uniform language for knowledge and data representation, deductive information retrieval and linguistic analysis. The objective of designing this system was the development of a feasible method for consulting and creating data bases in natural Portuguese. The system is implemented in Prolog, a programming language essentially identical in syntax and semantics to a subset of predicate calculus in clausal form.     

调用模式和正确调用模式语义在Prolog程序测试中的应用*

将基于调用模式语义和正确调用模式语义的程序分析技术应用于Prolog程序的CPM测试。通过调用模式分析获得内部过程被调用和成功调用的条件,利用前者删除不满足调用条件的测试帧,或当删除条件不满足时利用该条件更新测试规格中过程属性的划分准则;利用后者预测CPM测试的结果。该方法可较好地保持程序测试的质量,改善Prolog程序的CPM测试过程。     

对语义网查询语言的逻辑推理优化

为了在SeRQL RDF查询语言的语境中对查询进行的转换和优化,提出了使用Prolog语言来处理推理策略原型的RDF图的方法,以及将SeRQL查询转化为优化Prolog目标的算法,实现了对语义网语言的结构化变换,并验证了Prolog模块的性能。     

A KNOWLEDGE-BASED SYSTEM FOR COURSE SCHEDULING

Abstract

A knowledge-based scheduling system has been developed for the domain of university class scheduling. The problem addressed is how to schedule courses during the various time periods throughout the day. The class schedule must satisfy a variety of appropriate constraints. The system, written in Prolog, resolves conflicting assignments through backtracking. The inefficiency of Prolog's backtracking feature, with respect to this application, is partly circumvented by the use of a dynamic circular array. The system is now being used to help schedule industrial engineering classes at the Pennsylvania State University.     

POPE — a parallel-operating prolog engine

An architecture is presented for the parallel execution of sequential Prolog. The architecture is based on a pipeline of unification processors and designed to work as a co-processor to a more conventional, UNIX based workstation. The unification processors execute highly optimized compiled Prolog code; however, the basic concept of the architecture could also increase the performance of interpreter based systems. It will be shown that even programs that do not exhibit any of the ‘classical’ forms of parallelism (i.e. AND-, OR-parallelism, etc.) can be effectively mapped onto the proposed architecture. The presented architecture should also prove very effective as a multi-user Prolog machine executing several independent Prolog programs in parallel. In contrast to other attempts to execute sequential Prolog in parallel we do not restrict the use of any of the standard Prolog language features such as dynamic assert/retract, CUT, etc. Simulation results show that peak execution rates of over 1000 KLIPS can be obtained.     

Critical factors in the evolution of logic programming and Prolog

Logic programming has received much critical attention over the past two decades from both a language perspective and as a methodology for practical problem solving. This paper presents a historical foundation of the approach and examines the development of Prolog since its first implementation. An analysis of the use of Prolog in commercial, research and teaching environments shows that there is an established base of users and that, after a period of rapid growth, the language currently enjoys continuing activity. The key to its success so far is due to its continuing evolution by including features that were not seen as being within the original concept as a pure logic language. Significant features which have contributed to the success of Prolog include integration with other languages, object oriented extensions, constraint representation, parallel execution as well as improved speed and robustness. Applications databases are analysed with respect to type of application, system status, type of developer, hardware platform, country of origin and the Prolog implementation used. Factors contributing to the success of Prolog are identified and likely future developments are explored.     

An Operator Precedence Parser for Standard Prolog Text

Prolog is a language with a dynamic grammar which is the result of embedded operator declarations. The parsing of such a language cannot be done easily by means of standard tools. Most often, an existing parsing technique for a static grammar is adapted to deal with the dynamic constructs. This paper uses the syntax definition as defined by the ISO standard for the Prolog language. It starts with a brief discussion of the standard, highlighting some aspects that are important for the parser, such as the restrictions on the use of operators as imposed by the standard in order to make the parsing deterministic. Some possible problem areas are also indicated. As output is closely related to input in Prolog, both are treated in this paper. Some parsing techniques are compared and an operator precedence parser is chosen to be modified to deal with the dynamic operator declarations. The necessary modifications are discussed and an implementation in C is presented. Performance data are collected and compared with a public domain Prolog parser written in Prolog. It is the first efficient public domain parser for Standard Prolog that actually works and deals with all the details of the syntax.