On first glance agent technology seems more like a hostile intruder into the database world. On the other hand, the two could easily complement each other, since agents carry out information processes whereas databases supply information to processes. Nonetheless, to view agent technology from a database perspective seems to question some of the basic paradigms of database technology, particularly the premise of semantic consistency of a database. The paper argues that the ensuing uncertainty in distributed databases can be modelled by beliefs, and develops the basic concepts for adjusting peer-to-peer databases to the individual beliefs in single nodes and collective beliefs in the entire distributed database.

The use of multimedia in courseware and Web based learning is a current topic. This is influenced by the wide availability and the permanently improving technical possibilities. The employment of multimedia technology in education makes it possible to illustrate and to grasp complex processes and coherences. However, the development of multimedia content is still a very costly and tedious task. In order to reduce the costs and effort needed to build multimedia contents, it is desirable to organize the content in a modular way so that it can be (re)used and created cooperatively. The authors present a development process for multimedia contents that supports a modular cooperative design of multimedia courseware. They argue that applying modularity to courseware design not only reduces the costs but also allows the development of a high quality reusable and configurable courseware. Configurable courseware can be adapted to meet the needs and characteristics of different lecturers, students and contexts.

Since participants in a design process are almost separated in time (in addition to the usual separation in space), databases are an ideal medium to support and control their interaction. The basic premise of the paper is that each design artifact can be represented as a design object which occupies a certain domain in an n-dimensional work space which includes time in order to reflect the design stage during which certain design decisions are valid. The central hypothesis of the paper is that various kinds of interaction among designers (such as detecting the effects of decisions by other designers and responding to them by, e.g., performing corrections or retracing older states in order to resume work from there, and such as detecting that their own decisions may affect either designers and reacting to them by explicit notification of changes to other individuals) can all be explained by the same concept of work space collision. Constraints associated with the work spaces can be used to arbitrate between the conflicts in the colliding work spaces. The idea is applied to a variety of interaction forms to demonstrate its validity.

Some of the shortcomings of current view integration methodologies, namely, a low emphasis on full-scale automated systems, a lack of algorithmic specifications of the integration activities, inattention to the design of databases with new properties such as databases for computer-aided design, and insufficient experience with data models with a rich set of type and abstraction mechanisms, are attacked simultaneously. The focus is on design databases for software engineering applications. The approach relies on a semantic model based on structural object-orientation with various features tailored to these applications. The expressiveness of the model is used to take the first steps toward algorithmic solutions, and it is demonstrated how corresponding tools could be embedded methodically within the view integration process and technically within a database design environment. The central ideal is to compute so-called assumption predicates that express suggested similarities between structures in two schemas to be integrated, and then have a human integrator confirm or reject them. The basic method is exemplified for the CERM data model that includes molecular aggregation, generalization, and versioning.>

Classical treatment of consistency violations is to back out a database operation or transaction.In applications with large numbers of fairly complex consistency constraints this clearly is an unsatisfactory solution.Instead, if a violation is detected the user should be given a diagnosis of the constraints that failed, a line of reasoning on the cause that could have led to the violation, and suggestions for a repair.The problem is particularly complicated in a deductive database system where failures may be due to an inferred condition rather than simply a stored fact, but the repair can only be applied to the underlying facts.The paper presents a system which provides automated support in such situations.It concentrates on the concepts and ideas underlying the approach and an appropriate system architecture and user guidance, and sketches some of the heuristics used to gain in performance.

One of the most promising approaches to database support of engineering applications is the concept of object-oriented database management. Object-orientation is usually approached from either a behavioral or structural viewpoint. The former emphasizes the application-specific manipulation of technical objects while hiding their structural details whereas the latter concentrates on the structural aspects and their efficient implementation. The thesis of the paper is that the two viewpoints may enter into a fruitful symbiosis where a behaviorally object-oriented system is implemented on top of a structurally object-oriented database system, thereby combining ease of use by the engineer with high database system performance. The thesis will be demonstrated in the paper by a user-friendly interface based on user-definable abstract datatypes and its implementation using a prototype for the non-first-normal-form (NF2) relational model, and will be supported by an engineering example application from off-line robot programming.

Article Free Access Share on Acquisition of terminological knowledge using database design techniques Authors: Christoph F. Eick Fakultat fur Informatik, Universitat Karlsruhe, Postfach 6380, D-7500 Karlsruhe Fakultat fur Informatik, Universitat Karlsruhe, Postfach 6380, D-7500 KarlsruheView Profile , Peter C. Lockemann Fakultat fur Informatik, Universitat Karlsruhe, Postfach 6380, D-7500 Karlsruhe Fakultat fur Informatik, Universitat Karlsruhe, Postfach 6380, D-7500 KarlsruheView Profile Authors Info & Claims SIGMOD '85: Proceedings of the 1985 ACM SIGMOD international conference on Management of dataMay 1985Pages 84–94https://doi.org/10.1145/318898.318905Published:01 May 1985Publication History 20citation379DownloadsMetricsTotal Citations20Total Downloads379Last 12 Months14Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Database system support has become an essential part of many computer applications, which have extended beyond the more traditional commercial applications to, among others, engineering applications. Correspondingly, application programming with the need to access databases has progressively shifted to scientifically oriented languages. Modern developments in these languages are characterized by advanced mechanisms for the liberal declaration of data types, for type checking, and facilities for modularization of large programs. The present paper examines how a DBMS can be accessed from such a language in a way that conforms to its syntax and utilizes its type-checking facilities, without modifying the language specification itself, and hence its compilers. The basic idea is to rely on facilities for defining modules as separately compilable units, and to use these to declare user-defined abstract data types. The idea is demonstrated by an experiment in which a specific DBMS (ADABAS) is hosted in the programming language (LIS). The paper outlines a number of approaches and their problems, shows how to embed the DML into LIS, and how a more user-oriented DML can be provided in LIS.

Data abstractions were originally conceived as a specification tool in programming. They also appear to be useful for exploring and explaining the capabilities and shortcomings of the data definition and manipulation facilities of present-day database systems. Moreover they may lead to new approaches to the design of these facilities. In the first section the paper introduces an axiomatic method for specifying data abstractions and, on that basis, gives precise meaning to familiar notions such as data model, data type, and database schema. In a second step the various possibilities for specifying data types within a given data model are examined and illustrated. It is shown that data types prescribe the individual operations that are allowed within a database. Finally, some additions to the method are discussed which permit the formulation of interrelationships between arbitrary operations.