Fundamenta Informaticae - Volume 12, issue 1

Article Type: Other

DOI: 10.3233/FI-1989-12101

Citation: Fundamenta Informaticae, vol. 12, no. 1, pp. i-vii, 1989

Authors: Chen, Keh-Hsun

Article Type: Research Article

Abstract: In this paper, a new kind of dependencies for databases, called dynamic hierarchical dependencies (DH-dependencies), is proposed and studied. DH-dependencies naturally suit DH-databases, which are based on Sandwall’s dynamic data hierarchy structure. An efficient inference algorithm on DH-dependencies is proposed and its correctness is proved. Information retrieval with DH-dependencies is investigated.

DOI: 10.3233/FI-1989-12102

Citation: Fundamenta Informaticae, vol. 12, no. 1, pp. 1-12, 1989

Authors: Michalewicz, Zbigniew | Groves, Lindsay

Article Type: Research Article

Abstract: A number of approaches have been taken to incorporating sets in relational databases. We review three such approaches and discuss a new approach, called restricted cardinality sets , which combines aspects of the other approaches, allowing both compound values and incomplete information to be represented. We show that this approach generalizes the other approaches, leading to a simpler, more flexible representation; and discuss the definition of algebraic operations on such sets.

DOI: 10.3233/FI-1989-12103

Citation: Fundamenta Informaticae, vol. 12, no. 1, pp. 13-27, 1989

Authors: Bergadano, F. | Gemello, R. | Giordana, A. | Saitta, L.

Article Type: Research Article

Abstract: This paper describes ML-SMART, a knowledge based system for inducing conceptual description from examples. It is organized as a problem solver and makes an integrated use of multiple search strategies, including characterization, constructive learning and deduction. The acquired knowledge consists of production rules organized into a network, which can be seen as a generalization of a decision tree. The condition part of the rules is expressed in a first order logic language also containing numerical quantification. The use of variables and functions allows highly structured concepts to be easily described. ML-SMART (Similarity-based Multiple-concept Acquisition and Reasoning Tool) is …a domain independent system, provided with a friendly interface to ease the task of configuring a new application. It is well suited to work in noisy environments and has been tested in different domains for the sake of comparison with other existing systems. Show more

DOI: 10.3233/FI-1989-12104

Citation: Fundamenta Informaticae, vol. 12, no. 1, pp. 29-49, 1989

Authors: Banerji, Ranan B.

Article Type: Research Article

Abstract: In some previous papers I have made efforts at drawing attention to some crucial representational problems standing in the way of learning and at clarifying the technical underpinnings of these. These problems occur both in learning from examples and in learning from explanations. In the introduction to this paper these problems are reiterated in summary. It is also pointed out that they have direct implications in the way one attaches statistical significance to concepts learned from examples. Later sections to this paper describes an effort being made at present to develop a learning algorithm which uses a flexible language …of representation. The algorithm has a limited amount of ability to modify the representation language. The limitations of the method are also discussed. Show more

DOI: 10.3233/FI-1989-12105

Citation: Fundamenta Informaticae, vol. 12, no. 1, pp. 51-77, 1989

Authors: Ras, Zbigniew W. | Zemankova, Mafia

Article Type: Research Article

Abstract: Humans are capable of producing compact high-level concept descriptions built from previously known concepts and attribute values. In the method presented here, initially concepts are described in terms of attribute values. These descriptions are in a probabilistic DNF form. Assuming a growing language, concepts already known to the system can be used in describing new concepts. The order of teaching the concepts is the key to producing their optimal descriptions. By “optimal” we mean the minimum number of occurrences of constants in descriptions. The problem of finding the minimal description for each concept is NP-complete, hence our proposed algorithm has …to be heuristic. Our strategy is based on clustering terms in concept descriptions in order to replace them by shorter higher level terms. Results of the algorithm are optimized concepts descriptions in terms of a growing language, and a concept network that can be used for further learning and reasoning within the concept knowledge base. Show more

DOI: 10.3233/FI-1989-12106

Citation: Fundamenta Informaticae, vol. 12, no. 1, pp. 79-95, 1989

Authors: Winkowski, Józef

Article Type: Research Article

Abstract: The equivalence of communicating processes with respect to their external behaviour is formalized and studied. The processes are represented by mathematical systems related to labelled event structures. The equivalence is similar to the known observational equivalence but it is defined in a manner which reflects how processes behave in distributed environments. It is shown that the introduced equivalence is a congruence with respect to operations as in CCS (Milner’s Calculus of Communicating Systems).

Keywords: process, action, occurrence, event, configuration, event structure, configuration system, sum, prefixing, composition, restriction, renaming, approximation order, fixed-point, observation, transition, simulation, bisimulation, equivalence

DOI: 10.3233/FI-1989-12107

Citation: Fundamenta Informaticae, vol. 12, no. 1, pp. 97-128, 1989