tailieunhanh - An Analysis of Geometric Modeling in Database Systems

According to our analysis, which included interviewing over 125 representative industry leaders in the region, the sector shows strong potential for growth across all dimensions: talent, which is affecting the creation of quality local content; content production, leveraging the expanding network of media free zones; consumption across traditional and new, digital platforms; and monetisation, through better targeting of audiences and new revenue streams. The industry is also expected to take advantage of the high proportion of young people in the Arab population. It is this segment that is best placed to drive content development and exploitation in this increasingly international. | An Analysis of Geometric Modeling in Database Systems ALFONS KEMPER and MECHTILD WALLRATH Universităt Karlsruhe Institut fur Informatik II D-7500 Karlsruhe West Germany The data-modeling and computational requirements for integrated computer aided manufacturing CAM databases are analyzed and the most common representation schemes for modeling solid geometric objects in a computer are described. The primitive instancing model the boundary representation and the constructive solid geometry model are presented from the viewpoint of database representation. Depending on the representation scheme one can apply geometric transformations to the stored geometric objects. The standard transformations scaling translation and rotation are outlined with respect to the data structure aspects. Some of the more recent developments in the area of engineering databases with regard to supporting these representation schemes are then explored and a classification scheme for technical database management systems is presented that distinguishes the systems according to their level of object orientation structural or behavioral object orientation. First several systems that are extensions to the relational model are surveyed then the functional data model DAPLEX the nonnormalized relational model NF2 and the database system R2D2 that provides abstract data types in the NF2 model are described. Categories and Subject Descriptors Programming Languages Language Constructs abstract data types- Database Management Logical Design data models Languages data description languages DDL data manipulation languages DML query languages Computer Applications Computer-Aided Engineering computer-aided manufacturing Computer Graphics Computational Geometry and Object Modeling hierarchy and geometric transformation General Terms Design Languages Additional Key Words and Phrases Engineering database systems geometric modeling object-oriented database systems INTRODUCTION Motivation