The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform
Mario Luiz Tronco - One of the best experts on this subject based on the ideXlab platform.
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a Logical approach to the management of object identifiers in non conventional database management systems
Parallel and Distributed Computing: Applications and Technologies, 2011Co-Authors: Carlos Roberto Valencio, Andre Cid Ferrizzi, Bio Renato F De Almeida, Juliano Augusto Carreira, Mario Luiz TroncoAbstract:Non-conventional database management systems are used to achieve a better performance when dealing with complex data. One fundamental concept of these systems is object identity (OID), because each object in the database has a unique identifier that is used to access and reference it in relationships to other objects. Two approaches can be used for the implementation of OIDs: physical or Logical OIDs. In order to manage complex data, was proposed the Multimedia Data Manager Kernel (NuGeM) that uses a Logical Technique, named Indirect Mapping. This paper proposes an improvement to the Technique used by NuGeM, whose original contribution is management of OIDs with a fewer number of disc accesses and less processing, thus reducing management time from the pages and eliminating the problem with exhaustion of OIDs. Also, the Technique presented here can be applied to others OODBMSs.
Elena V. Ravve - One of the best experts on this subject based on the ideXlab platform.
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Dependency preserving refinements and the fundamental problem of database design
Data & Knowledge Engineering, 1998Co-Authors: Johann A. Makowsky, Elena V. RavveAbstract:We introduce a new point of view into database schemes by applying systematically an old Logical Technique: translation schemes, and their induced formula and structure transformations. This allows us to re-examine the notion of dependency preserving decomposition and its generalization refinement. We demonstrate the usefulness of this approach by recasting the theory of vertical and horizontal decompositions in our terminology. The most important aspect of this approach, however, lies in laying the groundwork for a formulation of the Fundamental Problem of Database Design, namely to exhibit desirable differences between translation equivalent presentations of data and to examine refinements of data presentations in a systematic way. The emphasis in this paper is not on results. The main line of thought is an exploration of the use of an old Logical tool in addressing the Fundamental Problem. Translation schemes allow us also to have a new look at normal forms of database schemes and to suggest a new line of search for other normal forms. Illustrating our Techniques we show that every scheme specified by functional and inclusion dependencies has a dependency-preserving refinement into BCNF. Furthermore we give a characterization of the embedded implicational dependencies (EID's) using FD's and inclusion dependencies (ID's) and a basic class of refinements consisting of projections and natural joins.
Carlos Roberto Valencio - One of the best experts on this subject based on the ideXlab platform.
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a Logical approach to the management of object identifiers in non conventional database management systems
Parallel and Distributed Computing: Applications and Technologies, 2011Co-Authors: Carlos Roberto Valencio, Andre Cid Ferrizzi, Bio Renato F De Almeida, Juliano Augusto Carreira, Mario Luiz TroncoAbstract:Non-conventional database management systems are used to achieve a better performance when dealing with complex data. One fundamental concept of these systems is object identity (OID), because each object in the database has a unique identifier that is used to access and reference it in relationships to other objects. Two approaches can be used for the implementation of OIDs: physical or Logical OIDs. In order to manage complex data, was proposed the Multimedia Data Manager Kernel (NuGeM) that uses a Logical Technique, named Indirect Mapping. This paper proposes an improvement to the Technique used by NuGeM, whose original contribution is management of OIDs with a fewer number of disc accesses and less processing, thus reducing management time from the pages and eliminating the problem with exhaustion of OIDs. Also, the Technique presented here can be applied to others OODBMSs.
Johann A. Makowsky - One of the best experts on this subject based on the ideXlab platform.
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Dependency preserving refinements and the fundamental problem of database design
Data & Knowledge Engineering, 1998Co-Authors: Johann A. Makowsky, Elena V. RavveAbstract:We introduce a new point of view into database schemes by applying systematically an old Logical Technique: translation schemes, and their induced formula and structure transformations. This allows us to re-examine the notion of dependency preserving decomposition and its generalization refinement. We demonstrate the usefulness of this approach by recasting the theory of vertical and horizontal decompositions in our terminology. The most important aspect of this approach, however, lies in laying the groundwork for a formulation of the Fundamental Problem of Database Design, namely to exhibit desirable differences between translation equivalent presentations of data and to examine refinements of data presentations in a systematic way. The emphasis in this paper is not on results. The main line of thought is an exploration of the use of an old Logical tool in addressing the Fundamental Problem. Translation schemes allow us also to have a new look at normal forms of database schemes and to suggest a new line of search for other normal forms. Illustrating our Techniques we show that every scheme specified by functional and inclusion dependencies has a dependency-preserving refinement into BCNF. Furthermore we give a characterization of the embedded implicational dependencies (EID's) using FD's and inclusion dependencies (ID's) and a basic class of refinements consisting of projections and natural joins.
Kalipada Maity - One of the best experts on this subject based on the ideXlab platform.
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application of mcdm based topsis method for the optimization of multi quality characteristics of modern manufacturing processes
International Journal of Engineering Research in Africa, 2016Co-Authors: Akhtar Khan, Kalipada MaityAbstract:Optimization of non-conventional machining (NCM) processes viz. AJM, AWJM, EDM, WEDM, ECM, ECMM, LBM, PAC, etc. has always been an open research area for researchers. In recent manufacturing environment, almost all the NCM processes consist of a number of input and output to be considered together. The purpose of the present article is to highlight the application of a multi-criteria decision making (MCDM) based method called Technique of Order Preference by Similarity of Ideal Solution (TOPSIS) in optimization of some modern manufacturing processes (MMPs). In the present paper, seven different MMPs namely Electro Chemical Honing (ECH), Abrasive Water Jet Machining (AWJM), Abrasive Jet Machining (AJM), Laser Beam Machining (LBM), Plasma Arc Cutting (PAC), Laser Cutting (LC) and Electric Discharge Machining (EDM) were exemplified. The multiple outcomes of all the illustrated MMPs have been optimized simultaneously by using TOPSIS method. It is a simple, systematic, and Logical Technique which can be employed to obtain the best parametric combination of cutting parameters. It was observed that the results attained by using TOPSIS method were almost tie with those derived by past researchers. This proves the applicability and adaptability of the TOPSIS method while solving different MCDM-based problems in a real manufacturing system.
