From database to normbase

After the database concept, we are ready for the normbase concept. The object is to decouple organizational and technical knowledge that are now mixed inextricably together in the application programs we write today. The underlying principle is to find a way of specifying a social system as a system of norms. Our existing languages, developed to handle machine-like structures, do not enable us to embed our technical systems comfortably into the far more subtle human systems they should be serving.\ud \ud The present approach to the design of formal systems incorporates a philosophical position that obstructs one's thinking about the relationship between social systems and technical systems. The existing specification languages embody a view of the world as an objective reality. But social systems are constructed by their participants, so we propose a language that treats the world as essentially subjective. Our way of doing so introduces two fundamental postulates: (1) there is no reality without an agent, and (2) the agent only knows the world through actions. Based on these postulates, a formalism has been created that enables us to represent systems of social norms.\ud \ud In this system, meaning is regarded as a relationship between sign and behaviour (more strictly, invariants in the flux of behaviour). Semantic analysis is an essential prelude to norm analysis. A new prototype implementation of this normbase is under construction. The goal envisaged is explained in terms of an illustration of how the normbase would be used to develop a system. At every stage of design, the specification is turned immediately into a default version of a working system. The application programmer can then concentrate on tuning this system or developing another that can perform the business functions in the most efficient technical manner. Experiments have already shown the viability of the concepts and methods incorporated in this normbase

A Critical Review of Temporal Database Management Systems

There have been significant research activities in Temporal Databases during the last decade. However, the developments of a semantics of time, a temporal model for efficient database systems and temporal query languages still need much study. Based on the researches of the TDB group [Snodgrass 1987], the review of research about TDBMS in this dissertation mainly emphasises three aspects as follows. 1) The formulation of a semantics of time at the conceptual level. A topology of time and types of time attributes are introduced. A new taxonomy for time attributes is presented: assertion time, event time, and recording time. 2) The development of a model for TDBMS analogous to relational databases. Based on Snodgrass' classification, four kinds of databases: snapshot, rollback, historical and temporal are discussed in depth. But the discussion distinguishes some important differences from the representation of the TDB model: - historical relation for most enterprises is an interval relation, but not a sequence of snapshot slices indexed by valid time. The term "tuple" no longer simply refers to an entity as in traditional relational databases. It refers to different level representations of an object: entity, entity state, observation of entity, and observation of entity state in different types of databases. 3) The design of temporal query languages. We do not present a new temporal query language in this dissertation, but we discuss a Quel-like temporal query language, TQuel, in some depth. TQuel is compared with two other temporal query languages TOSQL and Legol 2.0. We centre the main discussion on TQuel's semantics for tuple calculus. The classification for the relationships between overlapping intervals suggests an approach using temporal logic to classify the derived tuples in tuple calculus. Under such an approach, a new presentation for tuple modification calculus is proposed, not only for interval relations, but also for event relations

Legal knowledge engineering: Computing, logic and law

The general problem approached in this thesis is that of building computer based legal advisory programs (otherwise known as expert systems or Intelligent Knowledge Based Systems). Such computer systems should be able to provide an individual with advice about either the general legal area being investigated, or advice about how the individual should proceed in a given case. In part the thesis describes a program (the ELl program) which attempts to confront some of the problems inherent in the building of these systems. The ELl system is seen as an experimental program (currently handling welfare rights legislation) and development vehicle. It is not presented as a final commercially implementable program. We present a detailed criticism of the type of legal knowledge contained within the system. The second, though in part intertwined, major subject of the thesis describes the jurisprudential aspects of the attempt to model the law by logic, a conjunction which is seen to be at the heart of the computer/law problem. We suggest that the conjunction offers very little to those who are interested in the real application of the real law, and that this is most forcefully seen when a working computer system models that conjunction. Our conclusion is that neither logic nor rule-based methods are sufficient for handling legal knowledge. The novelty and import of this thesis is not simply that it presents a negative conclusion; rather that it offers a sound theoretical and pragmatic framework for understanding why these methods are insufficient - the limits to the field are, in fact, defined

Conceptual Modeling in Law: An Interdisciplinary Research Agenda

The article describes how different approaches from the IS field of conceptual modeling should be transferred to the legal domain to enhance comprehensibility of legal regulations and contracts. It is further described how this in turn would benefit the IS discipline. The findings emphasize the importance of further interdisciplinary research on that topic. A research agenda that synthesizes the presented ideas is proposed based on a framework that structures the research field. Researchers from both disciplines, IS and Law, that are interested in this field should use the research agenda to position their research and to derive new and innovative research questions

Temporal data, temporal data models, temporal data languages and temporal database systems.

The study of temporal database systems is relatively new in the field of computer science. Two developments have led to the present interest. The advances of the storage technology for large amounts of data and applications' requirements for time-dependent data have prompted our study of temporal databases. This thesis conducts a survey of the major research areas concerning temporal databases. Temporal data, taxonomies of temporal data models, temporal data languages, and temporal database systems are presented. It is argued here that future database systems should handle the temporal domain by an integrated temporal database system. By understanding the present technology and the need of temporal database systems, our research in the area of real-time temporal database systems can begin. It is the purpose of this thesis to provide the background information and research references of temporal database systems as a first step towards the real-time database system research. Real-time database systems are time-constrained and temporally constituted. Solutions in temporal database systems can contribute to the design of real-time military applications using temporal database computers.http://archive.org/details/temporaldatatemp00homdCaptain, United States Marine CorpsApproved for public release; distribution is unlimited

Time dimension in the relational model

Call number: LD2668 .T4 CMSC 1987 C52Master of ScienceComputing and Information Science

Une méthodologie automatisée de la logique juridique

Le droit est une matière qui se prête très bien au traitement informatique. En effet nous pouvons dans cette discipline identifier deux aspects différents et complémentaires de la même réalité, à savoir l'aspect éthique et l'aspect logique. Dans cette étude, l'auteur se penche sur l'aspect logique du droit. Pour ce faire, il utilise la logique formelle afin de réduire sous forme de règles la matière portant sur le remboursement des améliorations faites sur l'immeuble d'autrui. Le résultat final en est un d'intelligence artificielle avec la réalisation d'un système expert portant le nom de LEX-A. Celui-ci a été réalisé sur ordinateur Macintosh et utilise le langage de programmation PROLOG.Law is a subject matter that lends itself well to data processing. Indeed, it is a discipline in which we can identify the two distinctive and complementary aspects of one reality : the ethical and the logical aspects. In this study, as the ethical question has been settled beforehand, the author delves into the logical aspect of law. To do so, he uses formal logic so as to reduce to logical rules the data related to the refunding of improvements made to a third party's building. The final result is one of artificial intelligence with the realization of an expert system bearing the name LEX-A. It was developed on a Macintosh computer and uses the PROLOG programming language