Extraction and representation of facts from legal briefs

In knowledge-based consultation systems, the quality of the advice rendered depends on the techniques employed to represent the domain knowledge, the explanation generating capabilities, and the control strategies utilized during the consultative advice stage. The ability to understand the problem is more crucial in providing effective consultation. In this work, the emphasis is on understanding and the consequent formulation of a plausible internal representation of legal briefs. The system developed, SIFTER, reads the given input text from a legal practitioner's point of view and retrieves from it those facts that are relevant to the particular type of case on hand. In other words, it uses the domain specific knowledge to identify the type of case and to yank out the necessary information pertaining to the case. The SIFTER generates a noun-phrase processed form of the input which contains pseudo names for the proper-nouns, dates and time-intervals. The verbs in the processed input are used to check whether the case specific events have occurred or not and then the appropriate fact-containing noun-phrases are used to instantiate the relevant legal variables and, hence, to construct an internal representation of the given problem which can then be readily used by the consultative advice stage of a problem solver or analyzer. The implementation has been done in LISP culling the required domain knowledge from the Industrial Dispute Act of India.     

KET: A knowledge engineering tool

The paper describes a knowledge engineering tool (named KET) designed to facilitate the development of expert systems in various application areas. As an architecture and basic function the system implements the most essential features of domain-independent expert systems: knowledge base interactive development and refinement, forward as well as backward logical inference, utilisation of uncertain knowledge, etc.The KET language integrates a fairly rich subset of the first-order predicate logic with the production systems architecture, covering in this way the advantages of two basic approaches to the knowledge representation problem. The frame-oriented methodology is presented by the following options: the user can define simple concepts by specifying named collections of attribute-value pairs and interconceptual relations; he (or she) can also describe specific objects in a similar way, refering them to already defined concepts in particular. The language achieves additional power by allowing arbitrary terms to be used as values. It is relatively natural in the sense that the knowledge and system behaviour are easily understood in convenient to a naive user terms, i.e. concepts, objects, facts, rules, questions and commands.KET consists of compiler, interpreter, editor, front-end and input-output modules. Its prototype version is written in BASIC and is operational on an IMCO 2 (compatible with Apple II) computer.The paper also aims to compare the system with the logic programming language PROLOG as well as to discuss some issues of implementation and the applicational methodology.     

A general-purpose natural language interface to an operating system

One of the most difficult tasks facing new computer users is the management of data and programs through an operating system (OS) interface. Both command languages and graphical interfaces can impede a user unfamiliar with the terminology and organizational techniques of modern file management systems. Various attempts have been made in recent years to develop systems that will enable users to interact with the computer in natural language. By simplifying the form of user input to an OS, such interfaces allow the user to concentrate on file management tasks rather than on the means of expressing OS-specific instructions. The Informational Network for a Natural Talking (INFANT) System was originally developed as a conversational system for communication at the level of a small child. It has since been adapted for use as a general-purpose English language interface for standard OS file management operations. The INFANT System reduces an input sentence to a hierarchy of standardized propositional forms, which are mapped through a propositional knowledge base and a compositional semantics process into a high-level representation of meaning. Its effectiveness as a working natural language interface has been verified in a pair of experiments performed in a college computer lab. © 1996 John Wiley & Sons, Inc.     

A discretization method for nonlinear delayed non-affine systems

The input time delay is always existent in the practical systems. Analysis of the delay phenomenon in a continuous-time domain is sophisticated. It is appropriate to obtain its corresponding discrete-time model for implementation via digital computer. This paper proposes a new discretization method for calculating a sampled-data representation of nonlinear time-delayed non-affine systems. The proposed scheme provides a finite-dimensional representation for nonlinear systems with non-affine time-delayed input enabling existing nonlinear controller design techniques to be applied to them. The performance of the proposed discretization procedure is evaluated by using a nonlinear system with non-affine time-delayed input. For this nonlinear system, various time delay values are considered.     

多语种自然语言生成系统中的预映射句子规划器

自然语言生成是研究如何用计算机来生成自然语言文本的研究领域 ,经典结构是宏观规划、微观规划和表层生成的流水线结构 .分析了多语种自然语言生成系统 ACNL G中的微观规划器 ,提出了“基于语言资源预映射的句子优化器”,它不仅对句子进行优化 ,而且负责将语种无关的文章内容映射到具体语种的表达方式中 .其核心思想就是将处理过程同具体语种的语言资源相分离 ,但同时又以语言资源为导向 ,既继承了现有方法的优点 ,同时也解决了多语种条件下各语种之间细微差别的处理问题 ,使句子优化能够针对目标语种的特点进行优化操作 ,从而使优化效果有实质的提高 ,进一步发展了多语种文本生成的理论     

Implementation of rule-based information systems for integratedmanufacturing

Focuses on the development of a methodology within a software environment for automating the rule-based implementation of specifications of integrated manufacturing information systems. The specifications are initially formulated in a natural language and subsequently represented in terms of a graphical representation by the system designer. A new graphical representation tool is based on updated Petri nets (UPN) that we have developed as a specialized version of colored Petri nets. The rule-based implementation approach utilizes the similarity of features between UPN and the general rule specification language used for the implementation. The automation of the translation of UPN to the rule specification language is expected to considerably reduce the life-cycle for design and implementation of the system. The application presented deals with the control and management of information flow between the computer-aided design, process planning, manufacturing resource planning and shop floor control databases. This provides an integrated information framework for computer integrated manufacturing systems     

Multi-layer logic — A predicate logic including data structure as knowledge representation language

A new generation computer is expected to be the knowledge processing system of the future. However, many aspects are yet unknown regarding this technology, and a number of fundamental concepts, directly concerning knowledge processing system design need investigation, such as knowledge, data, inference, communication, information management, learning, and human interface. These concepts are closely related to knowledge representation. In particular, methodology to materialize such concepts as above in computers are completely dependent upon them. Thus, knowledge representation is a key concept in the design of knowledge processing systems and, consequently, of new generation computer systems. Knowledge representation design is a very important task affecting the performance of new generation computer systems to be developed. We should first investigate the requirements for precise knowledge representation, considering its effects on system performance, then design knowledge representations to satisfy these requirements. This paper discusses (1) a new style of information processing, (2) requirements for knowledge representation and (3) a knowledge representation satisfying these requirements, a knowledge processing system designed on this basis and a new style of problem solving using this system.     

An integrated system for knowledge sharing among heterogeneous knowledge derivation systems

Solving problems in a complex application domain often requires a seamles integration of some existing knowledge derivation systems which have been independently developed for solving subproblems using different inferencing schemes. This paper presents the design and implementation of an Integrated Knowledge Derivation System (IKDS) which allows the user to query against a global database containing data derivable by the rules and constraints of a number of cooperative heterogeneous systems. The global knowledge representation scheme, the global knowledge manipulation language and the global knowledge processing mechanism of IKDS are described in detail. For global knowledge representation, the dynamic aspects of knowledge such as derivational relationships and restrictive dependencies among data items are modeled by a Function Graph to uniformly represent the capabilities (or knowledge) of the rule-based systems, while the usual static aspects such as data items and their structural interrelationships are modeled by an object-oriented model. For knowledge manipulation, three types of high-level, exploratory queries are introduced to allow the user to query the global knowledge base. For deriving the best global answers for queries, the global knowledge processing mechanism allows the rules and constraints in different component systems to be indiscriminately exploited despite the incompatibilities in their inferencing mechanisms and interpretation schemes. Several key algorithms required for the knowledge processing mechanism are described in this paper. The main advantage of this integration approach is that rules and constraints can in effect be shared among heterogeneous rule-based systems so that they can freely exchange their data and operate as parts of a single system. IKDS achieves the integration at the rule level instead of at the system level. It has been implemented in C running in a network of heterogenous component systems which contain three independently developed expert systems with different rule formats and inferencing mechanisms.Database Systems Research and Development Center, Department of Computer Information Sciences, Department of Electrical Engineering, University of Florida     

Embedded system design with ada as the system design language

Recent research in software engineering has produced a number of techniques for structuring an understanding of systems. Many of these techniques are applicable to the design of embedded computer systems and produce designs whose structures are easily expressible in the ada language. This language is itself structured so that the design of a system can be expressed independently of its implementation. Thus ada can be a useful system design language (SDL) with these techniques. This paper describes the software design problem in the development of embedded computer systems. It shows how ada can be used as an SDL, as well as a system implementation language. The essential point is that as an SDL ada encourages designers to use recent theory to develop better structures for their systems, and its subsequent use to implement the systems preserves those structures in the product.     

The development of a specification language for a computer security system

The primary goal of this paper is to define an initial step towards the definition of ‘systems grammar’ based on the notion of formal languages which can be used as a ‘tool’ in the formal representation of computer security systems. Currently all modelling done on computer security systems is written up as mathematical models. These mathematical models are usually based on the mathematics of relations amongst objects, as opposed to the model described in this paper which is based on the theory of formal languages. This paper is aimed at people who are doing research on the logical aspects of computer security. It is the first of a series of two papers. This paper will give interim results and make more specific the definition of a ‘formal language’ which suits the computer security environment. The second paper will illustrate the actual use of the defined ‘formal language’ and show how to represent the characteristics of a computer security environment by using this ‘formal language’.     

Heuristic, symbolic logic and knowledge-based approach to the design and construction of buildings

The emergence of knowledge-based expert systems provide means with which one can use the computer as an aid to the solution of an ill-structured problem. Expert systems are interactive computer programs based on heuristics, incorporating judgement, rules of thumb, intuition and expertise to provide knowledgeable advice about variety of tasks. Such specialized interactive computer programs can broadly be classified as (1) identifying the relevant design knowledge, (2) providing a formalism for representing and processing the knowledge and (3) implementing the formalism in a computer environment. While the first issue of identifying the relevant knowledge is through knowledge acquisition from various domain experts and verification of the same by other domain experts. The second issue is proper formalism for the varied knowledge requiring the use of logics (prepositional calculus) as a symbolic language; heuristics or rules of thumb wherever necessary and a suitable reasoning methodology, i.e. an inference technique. The third issue is the evaluation of a suitable strategy for successful computer implementation, i.e. the computer problem is subdivided into smaller tasks which have easy solutions; and the capability of interacting the solutions of the smaller tasks into a larger framework. Therefore, this will require theorem proving, search technique and a special purpose computer language such as PROLOG or readily available domain independent shells, i.e. expert system tools. The overall synthesis of all the above is termed as a knowledge-based expert system (KBES). In this paper a KBES is developed for a highly complex building element, ‘beam design’, as part of a larger model involving planning, analysis, design, optimization and cost forecasts along with other allied services such as plumbing and electrical services. In the development of KBES; the knowledge-base is purely heuristic and subjected to alteration by numerical calculations. For an effective search the modified depth technique is adopted. Heuristics are employed to further the search as and when required from the point of view of practical computer implementation. In the overall development, use is made of dependency diagrams, charts, tables and search trees. For computer implementation the necessary tool chosen was the M1 shell developed by Teknowledge Inc., U.S.A. This requires a PC-AT with 640 kB RAM and 40 MB hard disk. A brief overview of the expert system, followed by an example problem, is presented.     

A Software Tool for Constructing Traditional Chinese Medical Expert Systems

It is an urgent task to hnplemeut a lot of expert systems to capture the valuable expertise ofexperienced doctors of traditional Chinese medicine.In order to meet the needs,a software tool isdeveloped.It features a unified diagnosis model,a specially designed knowledge representationlanguage and an efficient but effective inference engine.To implement an expert system,it isonly necessary to input the expert's knowledge expressed in knowledge representation languagewithout the design of any additional software.The time and effort required for implementing anexpert system are thus greatly saved.The software is very compact and can run onmicrocomputers e.g.IBM-PC/XT.Two traditional Chinese medical expert systems have beensuccessfully implemented with the tool.     

Parallel model representations

Most mathematical programming models and knowledge-based systems in optimization from exist in various representations; however, the user is frequently not aware of this. For example, a model which is developed with a knowledge-based system such as the PM system of Krishnan (1988) will have several representations in Prolog and then will be translated into another representation in Structured Modeling before it is solved. Also, a model which is developed in the GAMS language will be translated into an MPS input form internally before the problem is passed to a solver such as MINOS. The results from MINOS are then passed back to GAMS and the user sees the results in the style of the GAMS representation of the model. This could be called a vertical set of model representations since the user can modify only one representation and the models are passed down directly to the solver.

This paper argues that in considering knowledge-based systems with optimization we should begin to employ a set of parallel model representations, any one of which the user can see and modify. These can be called horizontal model representations. For example, a given model might be represented in graphical, knowledge base, modeling language, and mathematical forms. The user would be able to modify any of these versions and have the other representations altered automatically to reflect the changes.     

石油价格预测专家系统OPFES的设计与实现

本文以国际市场石油价格预测问题为背景,采用了大型专家系统设计方法,论述了一个石油价格预测专家系统 OPFES(Oil Price Forecast Expert System)的设计方法.在系统中采用了广义知识表达树作为知识表达方法,系统结构上采用了四库结构(模型库、方法库、数据库、知识库).在推理机方面采用了二级推理:元知识级推理与对象级推理的灵活方式.在人机接口方面,采用了多级菜单驱动方式与有限的自然语言理解方式.整个系统的原型系统用 Turbo-Prolog 语言已在 PC/AT 机上实现.     

Information Extraction and Knowledge Acquisition from Texts Using Bilingual Question–Answering

A novel approach is introduced in this paper for the implementation of a question–answering based tool for the extraction of information and knowledge from texts. This effort resulted in the computer implementation of a system answering bilingual questions directly from a text using Natural Language Processing. The system uses domain knowledge concerning categories of actions and implicit semantic relations. The present state of the art in information extraction is based on the template approach which relies on a predefined user model. The model guides the extraction of information and the instantiation of a template that is similar to a frame or set of attribute value pairs as the result of the extraction process. Our question–answering based approach aims to create flexible information extraction tools accepting natural language questions and generating answers that contain information extracted from text either directly or after applying deductive inference. Our approach also addresses the problem of implicit semantic relations occurring either in the questions or in the texts from which information is extracted. These relations are made explicit with the use of domain knowledge. Examples of application of our methods are presented in this paper concerning four domains of quite different nature. These domains are: oceanography, medical physiology, aspirin pharmacology and ancient Greek law. Questions are expressed both in Greek and English. Another important point of our method is to process text directly avoiding any kind of formal representation when inference is required for the extraction of facts not mentioned explicitly in the text. This idea of using text as knowledge base was first presented in Kontos [7] and further elaborated in [9,11,12] as the ARISTA method. This is a new method for knowledge acquisition from texts that is based on using natural language itself for knowledge representation.     

Modeling with the semantic Web in the geosciences

Earth system science deals with complex systems that pose many significant representation challenges. Ontologies as knowledge repositories have been developed to support the primary goal of sharing knowledge in a manner that aids understanding. DARPA is currently developing an extension to OWL called SWRL (semantic Web rule language), which lets to express some aspects of rules and process behaviors. The semantic Web facilitates researchers' collaboration and model components automated discovery and use. Spatial data plays a key role in modeling the earth system as the input to models and as a measure against which results are validated.     

A content-search information retrieval process based on conceptual graphs

An intelligent information retrieval system is presented in this paper. In our approach, which complies with the logical view of information retrieval, queries, document contents and other knowledge are represented by expressions in a knowledge representation language based on the conceptual graphs introduced by Sowa. In order to take the intrinsic vagueness of information retrieval into account, i.e. to search documents imprecisely and incompletely represented in order to answer a vague query, different kinds of probabilistic logic are often used. The search process described in this paper uses graph transformations instead of probabilistic notions. This paper is focused on the content-based retrieval process, and the cognitive facet of information retrieval is not directly addressed. However, our approach, involving the use of a knowledge representation language for representing data and a search process based on a combinatorial implementation of van Rijsbergen’s logical uncertainty principle, also allows the representation of retrieval situations. Hence, we believe that it could be implemented at the core of an operational information retrieval system. Two applications, one dealing with academic libraries and the other concerning audiovisual documents, are briefly presented.     

Heterogeneous knowledge representation: integrating connectionist and symbolic computation

Heterogeneous knowledge representation allows combination of several knowledge representation techniques. For instance, connectionist and symbolic systems are two different computational paradigms and knowledge representations. Unfortunately, the integration of different paradigms and knowledge representations is not easy and very often is informal. In this paper, we propose a formal approach to integrate these two paradigms where as a symbolic system we consider a (logic) rule-based system. The integration is operated at language level between neural networks and rule languages. The formal model that allows the integration is based on constraint logic programming and provides an integrated framework to represent and process heterogeneous knowledge. In order to achieve this we define a new language that allows expression and modelling in a natural and intuitive way the above issues together with the operational semantics.     

Modeling robotic operations controlled by natural language

There are multiple ways to control a robotic system. Most of them require the users to have prior knowledge about robots or get trained before using them. Natural language based control attracts increasing attention due to its versatility and less requirements for users. Since natural language instructions from users cannot be understood by the robots directly, the linguistic input has to be processed into a formal representation which captures the task specification and removes the ambiguity inherent in natural language. For most of existing natural language controlled robotic system, they assume the given language instructions are already in correct orders. However, it is very likely for untrained users to give commands in a mixed order based on their direct observation and intuitive thinking. Simply following the order of the commands can lead to failures of tasks. To provide a remedy for the problem, we propose a novel framework named dependency relation matrix (DRM) to model and organize the semantic information extracted from language input, in order to figure out an executable sequence of subtasks for later execution. In addition, the proposed approach projects abstract language input and detailed sensory information into the same space, and uses the difference between the goal specification and temporal status of the task under implementation to monitor the progress of task execution. In this paper, we describe the DRM framework in detail, and illustrate the utility of this approach with experiment results.