271 research outputs found

    State-of-the-art on evolution and reactivity

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    This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks

    Active databases, business rules and reactive agents - what is the connection?

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    These three technologies were and still are mainly treated separately. Since not much work has been carried out in defining and combining them together, we are going to present what has been done and put accent on what could be done. Namely, they rely upon similar paradigms and concepts, as will be shown later on, and can be treated as complementary technologies. In this paper we will show that reactive agents react according to some set of business rules and active databases can be used as a suitable means for implementing business rules and in those way reactive agents as well. Since reactive agents have been well defined, recent improvements in the fields of active databases technology and especially business rules provide the reason to consider the benefits to be achieved from combining these fields

    Active databases, business rules and reactive agents - what is the connection?

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    These three technologies were and still are mainly treated separately. Since not much work has been carried out in defining and combining them together, we are going to present what has been done and put accent on what could be done. Namely, they rely upon similar paradigms and concepts, as will be shown later on, and can be treated as complementary technologies. In this paper we will show that reactive agents react according to some set of business rules and active databases can be used as a suitable means for implementing business rules and in those way reactive agents as well. Since reactive agents have been well defined, recent improvements in the fields of active databases technology and especially business rules provide the reason to consider the benefits to be achieved from combining these fields

    OBJECTIVE: a benchmark for object-oriented active database systems

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    Cataloged from PDF version of article.Although much work in the area of Active Database Management Systems (ADBMSs) has been done, it is not yet clear how the performance of an active DBMS can be evaluated systematically. In this paper, we describe the OBJECTIVE Benchmark for object-oriented ADBMSs, and present experimental results from its implementation in an active database system prototype. OBJECTIVE can be used to identify performance bottlenecks and active functionalities of an ADBMS, and to compare the performance of multiple ADBMSs. (C) 1999 Published by Elsevier Science Inc. All rights reserved

    Autonomic Database Management: State of the Art and Future Trends

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    In recent years, Database Management Systems (DBMS) have increased significantly in size and complexity, increasing the extent to which database administration is a time-consuming and expensive task. Database Administrator (DBA) expenses have become a significant part of the total cost of ownership. This results in the need to develop Autonomous Database Management systems (ADBMS) that would manage themselves without human intervention. Accordingly, this paper evaluates the current state of autonomous database systems and identifies gaps and challenges in the achievement of fully autonomic databases. In addition to highlighting technical challenges and gaps, we identify one human factor, gaining the trust of DBAs, as a major obstacle. Without human acceptance and trust, the goal of achieving fully autonomic databases cannot be realized

    A Multimodal Biometric System Based on an Active Database Paradigm

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    Today, on many occasions and in many different places, one must be authorised in order to use certain services or applications or to access protected data. A user (person) can be authorised in three different ways or combinations of ways: it is either information that the user knows, something that the user possesses or a measurement of some physical or psychological characteristics unique to that user, i.e. biometric characteristics. In this paper we emphasize this third possibility. When talking about biometrics we can distinguish two basic types of systems: unimodal and multimodal. The main difference is that the unimodal biometric system is based solely on a single biometric feature, while multimodal biometric systems combine several features. We intend to show how active databases could be used in order to implement a multimodal (unimodal) biometric system and reduce the time needed for authorisation (identification or verification). Specifically, the concept of reactivity upon which active databases rely could be the core of a multimodal biometric system, as will be shown in the paper. We will especially consider the use of complex events used in active databases for authorisation purposes. Key words: ADBMS, active database, complex events, biometrics, biometric systemDandanes se velikokrat dogodi, da ljudje, ki hočejo koristiti določene storitve ali aplikacije ali želijo dobiti pristop do zaščitenih podatkov itd., potrebujejo avtorizacijo. Uporabnik se lahko avtorizira na tri različne načine oziroma s kombinacijo teh treh načinov: s pomočjo nečesa, kar uporabnik pozna, s pomočjo nečesa, kar uporabnik poseduje, ali s pomočjo merjenja določenih fizičnih ali psihičnih značilnosti, ki so lastne in enkratne vsaki osebi, tj. tako imenovanih biometričnih značilnosti. V tem prispevku bo poudarek na tem zadnjem, tretjem načinu. Ko govorimo o biometriki, lahko razlikujemo med dvema osnovnima tipoma biometričnih sistemov - enomodalnim in večmodalnim biometričnim sistemom. Glavna razlika med njima je v tem, da enomodalni biometrični sistem temelji le na eni biometrični značilnosti, medtem ko večmodalni biometrični sistem za avtoriziranje posameznika kombinira več biometričnih značilnosti. V tem prispevku bomo pokazali, kako se lahko pri vgradnji večmodalnega (enomodalnega) biometričnega sistema uporabijo aktivne baze podatkov, s čimer se skrajša čas, ki je potreben za avtorizacijo (identifikacijo ali verifikacijo). Med drugim bomo pokazali, da je koncept reaktivnosti, na katerem temeljijo aktivne baze podatkov, lahko jedro večmodalnih biometričnih sistemov. Posebno pozornost bomo posvetili kompleksnim dogodkom za avtorizacijske namene, ki se v glavnem uporabljajo v aktivnih bazah podatkov. Ključne besede: ADBMS, aktivna baza podatkov, kompleksni dogodki, biometrika, biometrični siste

    Data Base Management Systems Panel. Third workshop summary

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    The discussions and results of a review by a panel of data base management system (DRMS) experts of various aspects of the use of DBMSs within NASA/Office of Space and Terrestrial Applications (OSTA) and related organizations are summarized. The topics discussed included the present status of the use of DBMS technology and of the various ongoing DBMS-related efforts within NASA. The report drafts of a study that seeks to determine the functional requirements for a generalized DBMS for the NASA/OSTA and related data bases are examined. Future problems and possibilities with the use of DBMS technology are also considered. A list of recommendations for NASA/OSTA data systems is included
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