Abstract: Die Moving Picture Experts Group, eine Arbeitsgruppe der ISO SC29, ist seit 1988 aktiv und hat mit ihren MPEG-1/2/4 einen entscheidenden Einfluss auf die Multimedia-Industrie genommen.Mit der Verabschiedung MPEG-7 wurde von der Moving Picture Experts Group (MPEG) im März 2002 als Internationaler Standard verabschiedet. Nach der erfolgreichen Einführung der Standards MPEG-1/2/4 zur audiovisuellen Kodierung von Inhalten ist MPEG-7 ein Standard, der ein Austauschformat für Beschreibungen von multimedialen Inhalten festlegt.

Abstract: The Multimedia Description Standard MPEG-7 is an International Standard since February 2002. It defines a huge set of description classes for multimedia content, for its creation and its communication. This article investigates what MPEG-7 means to Multimedia Database Systems (MMDBSs) and vice versa. We argue that MPEG-7 has to be considered complementary to, rather than competing with, data models employed in MMDBSs. Finally we show by an example scenario how these technologies can reasonably complement one another..

Abstract: Multimedia databases; Processing of a multimedia join; Nearest neighbor search.

Abstract: This paper focuses on parallel query optimization. We consider the operator problem and introduce a new class of execution strategies called Linear-oriented Bushy Trees (LBT). Compared to the related approach of the General Bushy Trees (GBT) a significant complexity reduction of the operator ordering problem can be derived theoretically and demonstrated experimentally (e.g. compared with GBTs, LBTs authorize optimization time improvement that can reach up to 49%) without losing quality. Finally we demonstrate that existing commercial parallel query optimizers need little extension mod ifications in order to handle LBTs.

Abstract: Es läuft eine spannende Diskussion darüber, wie früh man Kinder an den Computer heranführen sollte. Jenseits solcher Intellektuellen-Diskussionen machen manche Firmen schon seit Jahren enorme Geschäfte mit Software und Hardware für Kinder im Kindergartenalter. Auch der erste Computer für Babys hat schon seinen Siegeszug auf dem amerikanischen Markt angetreten. Mit den Geschäftemachern zu diskutieren, ist wahrscheinlich nicht viel klüger als gegen Windmühlen zu kämpfen. Diese Firmen könnten ihre Geschäfte nicht machen, wenn es nicht viele Eltern, Großeltern, Pädagogen und Psychologen gäbe, die den Computer kleinen Kindern mit guter Absicht in die Hand geben. Die folgende Diskussion spricht die wohlwollenden Erwachsenen an, die sich für Kinder verantwortlich fühlen und sich nicht entscheiden können, wann und wie Kinder mit dem Phänomen Computer konfrontiert werden sollten.

Abstract: An approach is introduced for semi-automatic parallelization of object-oriented simulations. The basic idea is to prepare parallelization at the earliest possible stage in the life-cycle of the creation of new simulations (i.e. at modeling), thus minimizing causality conflicts at run-time. The object-oriented model of a simulation is enriched by hints, describing the estimated load and communication costs between major classes and objects. This helps to grasp the inherent parallelism of the model. Based on this additional information, a partitioning with minimal communication between partitions can be generated automatically. Remaining dependency-conflicts must be resolved at run-time. The GoSim [A. Stopper, GoSim, ein Ansatz zur Beschleunigung diskreter, objektorientierter, verteilter Simulationen, Ph.D. Thesis, Institute of Informatics, University Klagenfurt, 1997] simulation system is presented, which implements the described proposal and provides semi-automatic parallelization of large-scale and/or high-performance simulations. It provides a description language, a partitioning tool, a program-skeleton generator and a simulation engine. Some measurements prove the usability of the approach.

Abstract: The choice of the first-course programming language for a university-level computer science curriculum has pedagogical ramifications in terms of comprehensibility and mastery of fundamental concepts. This paper compares the merits of Java and Modula-3 as a first-course language.

Abstract: An architecture for a memory-resident, Parallel and Persistent ObjectSTore (PPOST) is suggested. Different object-oriented databases might be built on top of PPOST. The term memory-resident (or main memory based) means that the primary storage device is main memory. Persistence is guaranteed automatically by managing secondary and stable storage devices (such as main memory with uninterrupted power supply, discs and tapes). The architecture is able to take advantage of available main memory in a parallel or distributed environment. Thus, transactions can be actually performed with memory-speed, without being limited by the size of the memory of a given computer. Such an architecture is especially advantageous for applications requiring very fast answers, such as CAD or high-performance simulation.

Abstract: We claim that distributed object-oriented systems must provide a higher level of abstraction to their users, than usually provided. Especially, it is necessary to provide application-oriented, intelligent aggregates of objects with transparent distribution of their elements. Beside that, it seems to be not only reasonable, but also relatively easy to connect persistence with distribution. A system, offering distributed and persistent polymorphic sets of objects, on the level of a clean, type safe programming language is introduced. The user of such a system gets distribution and persistence in the same "natural" way, as users of traditional systems get volatile arrays of numbers or classes of objects.

Abstract: Informatik in der Schule - Informatik für die Schule.