Abstract: Software now accounts for most of the cost of computer-based systems. Over the past thirty years, abstraction techniques such as high level programming languages and abstract data types have improved our ability to develop software. However, the increasing size and complexity of software systems have introduced new problems that are not solved by the current techniques. These new problems involve the system-level design of software, in which the important decisions are concerned with the kinds of modules and subsystems to use and the way these modules and subsystems are organized. This level of organization, the software architecture level, requires new kinds of abstractions. These new abstractions will capture essential properties of major subsystems and the ways they interact.

Abstract: In most object-oriented databases, as opposed to value-oriented databases, data are accessed by a programming language instead of a declarative query language. End users do not have a simple tool to perform their queries. This paper is concerned with the definition of an SQL-like query language on top of the O2 object-oriented database system. We study the influence of the object-oriented paradigm on a query language, describe our language through examples, define its semantics by means of an algebra and sketch the compilation of RELOOP in one of the languages supported by the O2 system.

Abstract: This paper describes the notion of Multilevel Secure Database Management System (MLS/DBMS) and the difficulties encountered in designing such a system. It then states a security policy for an MLS/DBMS and describes a design for query and update operation. Finally, the notion of a Multilevel Secure Knowledge Base Management System (MLS/KBMS) and a design for query operation in an MLS/KBMS is discussed.

Abstract: With the recent progress and popularization of computers and computer communications, the technology for the integrated use of distributed computer hardware and softwares through computer networks is becoming important. Especially, in the current paradigm of knowledge processing, it has become one of the main subjects to couple the knowledge based systems with remote or local database systems for their integrated and more intellectual use. We introduce a knowledge processing system KAUS (Knowledge Acquisition and Utilization System), which is a logic based system, and describe how to couple it loosely with existing relational database systems (RDBMSs). In loosely coupling, we take an approach to generate an intermediate language for the database access from the given query, translate it to the target RDB language then evaluate it in the RDBMS, and finally receive the result from the RDBMS. Queries implying database access are evaluated by the mixed use of interpretive and compiled method. We illustrate examples of coupling KAUS with a database system UNIFY which supports SQL and a personal database system dBaseIII which supports its own procedural language for data manipulation.

Abstract: AI techniques are currently applied to the development of products that are predominantly software. Without the benefit of software engineering practices and tools, AI based product development will follow the same lack of efficiency and productivity characteristic of conventional software production. To further the development to maturity of software engineering practice, the Software Engineering Institute conducts activities that lead to strengthening software engineering and the professionals who practice it. The institute will thus contribute also to the improvement of products that apply AI techniques.

Abstract: This paper carries out a retrospective analysis of the evolution of Software Engineering with reference to its techniques as well as its methodology. It then follows on to the development of Knowledge Engineering and considers the two approaches which were successively put forward: the paradigm of power as opposed to the paradigm of knowledge and their integration. Finally the existing similarities and differences between both KE and SE are established. These similarities and differences are analysed in the following four fields: in the design and development of software products and technologies; in the tools and design techniques and building of software; in the architecture of the software system; and in the architecture of the hardware system.

Abstract: The concept of a new universal relation system, called UDH (unified database handler), is given, allowing enquiries of relational databases without references to the underlying database scheme. Also, UDH attempts to decouple data manipulation requests from the database scheme via an additional layer above the database scheme, called semantic object scheme.

Abstract: We extend Datalog, a logic programming language for rule-based systems, by respectively integrating types, negation and functions. This extention of Datalog is called MilAnt. Furthermore, MilAnt consistency is defined as a stronger form of consistency for functions. It is known that consistency for functions is undecidable. We prove that MilAnt consistency is decidable and an algorithm is given to detect the MilAnt consistency of a MilAnt program. To this end, we use a mixture of dependencies that are local to a rule and dependencies that are global for the whole program.

Abstract: Designers of knowledge-based systems seem to have the perception that realistic systems can be built by individual programmers. This approach no longer works for very large systems. Building large systems is a collaborative effort of people who each take responsibility for only part of the work. Software engineering has focused on the complications arising from system size and organizing people. This paper describes how software engineering might help in recognizing the problems of building large knowledge-based systems and in offering some methods tools and techniques to solve these problems. The paper ends with making the point that benefits may also flow in the other direction, from Artificial Intelligence to software engineering, resulting in a general improvement of these tools, methods and techniques.

Abstract: A deductive object base is a deductive database that is constructed based of an object data model. Using mathematical logic as formal representation, it can be constructed to support classification, aggregation, generalization, and association. It further extends existing databases with procedural semantics. In this paper we extended the framework of deductive object base with the constructs for meta-knowledge. To enhance the quality of knowledge, we also present a knowledge assimilation scheme based on the resolutional scheme.

Abstract: A satisficing knowledge-based system reaches a satisfactory resolution as quickly as possible. A satisfactory resolution is one that reaches an answer that may not be optimal, but is satisfactory or heuristically “close enough”. This work focuses on the principles that can be used to support a methodology that will produce satisficing decisions in a data-driven knowledge-based system. A codified satisficing methodology that has been implemented is also presented. The purpose of satisficing is to resolve as few initial condition and goal states as can be managed consistent with reaching a satisfactory answer. This is within the normal constraints of an expert system, namely that the graph resolution would appear to be “natural” to a human user. This requires that the inference engine satisfactorily exhaust a particular topic before moving onto the next topic. Satisficing constraints, when attained, indicate that there is sufficient supporting information for a rule and that the evidence for it does not need to be further considered.

Abstract: Vertical fragmentation in database design is the process of assigning attributes to physical segments to improve the database performance. Experiments were conducted to measure the performances of four Fragmentation design methods in the three hardware environments with six transaction mixes, using simulation and quantitative modelling. Some hypotheses are laid down regarding database performance and are validated. The MRGB design method which considered the hardware characteristics produced highest fragmentation in micro (IBM AT), and lowest in mini (Prime), with mainframe (IBM) in between. MRGB design performed the best in the three systems. The Hammer & Niamir's design did its best in mini (61%), and better in mainframe (50%) than in mini (41%) in low update environment. While the fully fragmented design performed the best in micro and the worst in mainframe, the unfragmented design performed the best in mini and the worst in micro.

Abstract: A measure of semantic relatedness based on distance between objects in the database schema has previously been used as a basis for solving a variety of natural language understanding problems including word sense disambiguation, resolution of semantic ambiguities, and attachment of post noun modifiers. The use of min/max values which are usually recorded as part of the process of designing the database schema is proposed as a basis for solving the given problems as they arise in natural language database requests. The min/max values provide a new source of knowledge for resolving ambiguities and a semantics for understanding what knowledge has previously been used by distance measures in database schemas.

Abstract: This paper discusses the relationship between two optimization methods in deductive databases: the distribution of selections and the magic sets method. The former is a direct generalization of pushing selections in relational databases, and the latter realizes a more general view of selection propagation. The characteristics of the generalized form of the distribution of selections are discussed and compared to other methods. It is shown that the distribution of selections corresponds to one of the least effective variations of the magic sets method. It is also shown that both methods have essentially the same power for non-recursive queries. Hence, the magic sets method can be regarded as a natural generalization of pushing selections in relational databases.

Abstract: This paper describes the transformations used to produce an executable prototype from a very high level description of a software system in a computer-aided prototyping process. The high level description can include real-time constraints, which are difficult to treat using conventional compiler technology. The prototyping system uses two different sets of transformations, one for realizing data flow diagrams and the other for realizing hard real-time constraints. The transformations are implemented with the aid of an automatic translater generator.

Abstract: The utility and interest that proverbs and saying have always had is well known. All of them can be used when the space and time context is appropriate. In this sense, they can sometimes be used as heuristics. Nowadays, interest about game playing is focused in machine learning. The proposed system is based on a learning mechanism that acquires skills by modifying its behavior when studying past games. It selects a domino, taking into account the history of its games and, particularly, the “good” and “bad” moves. At the same time, scripts of actuation are generated by analyzing victories and losses.

Abstract: An expert system approach has recently been used for VSAM (Virtual Storage Access Method) file organisation [2] This paper applies a heurestic approach to the process of selecting physical organisations for multi-dimensional (m-d) data It analyses features of various access methods and using expert knowledge matches features for a range of m-d algorithms with corresponding characteristics of an application This paper focus on the system design of the KBS An example of the heuristic decision process is illustrated How to deal with incomplete information is briefly discussed

Abstract: It is desirable to answer queries posed to deductive databases by computing fixpoints because such computations are directly amenable to set-oriented fact processing. However, the classical fixpoint procedures based on bottom-up processing — the naive and semi-naive methods — are rather primitive and often inefficient. In this article, we rely on bottom-up meta-interpretation for formalizing a new fixpoint procedure that performs a different kind of reasoning: We specify a top-down query answering method, which we call the Backward Fixpoint Procedure. Then, we reconsider query evaluation methods for recursive databases. First, we show that the methods based on rewriting on the one hand, and the methods based on resolution on the other hand, implement the Backward Fixpoint Procedure. Second, we interpret the rewritings of the Alexander and Magic Set methods as specializations of the Backward Fixpoint Procedure. Finally, we argue that such a rewriting is also needed in a database context for implementing efficiently the resolution-based methods. Thus, the methods based on rewriting and the methods based on resolution implement the same top-down evaluation of the original database rules by means of auxiliary rules processed bottom-up.

Abstract: Object-oriented database systems are the focus of current research and development efforts Yet, there is no commonly accepted object model, nor is it clear whether such a model can be developed This paper reports on efforts to develop a formal framework that contains most features found in current object oriented database systems The framework contains two parts The first is a structural object model, including concepts such as structured objects, identity, and some form of inheritance For this model, we explain the distinction between values and (abstract) objects, describe a system as a directed graph, and discuss declarative languages The second part deals with higher-order concepts, such as classes and functions as data, methods, and inheritance This part is a sketch, and leaves many issues unresolved Throughout the paper, the emphasis is on logic-oriented modeling