Data Mining in a Multidimensional Environment

Data Mining and Data Warehousing are two hot topics in the database research area. Until recently, conventional data mining algorithms were primarily developed for a relational environment. But a data warehouse database is based on a multidimensional model. In our paper we apply this basis for a seamless integration of data mining in the multidimensional model for the example of discovering association rules. Furthermore, we propose this method as a userguided technique because of the clear structure both of model and data. We present both the theoretical basis and efficient algorithms for data mining in the multidimensional data model. Our approach uses directly the requirements of dimensions, classifications and sparsity of the cube. Additionally we give heuristics for optimizing the search for rules

MurMur: Database Management of MultipleRepresentations

Successful information management implies the ability to design accurate representations of the real world of interest to targeted applications. Current systems do not provide representation schemes supporting the diversity of user needs. In the context of interoperability, as in Web access to heterogeneous data sources, they can-not properly integrate the diversity of stored representations. The objective of the European project described inthis paper, MurMur 1 , is to enhance GIS (or DBMS) functionality so that, relying on more flexible representation schemes, users may easily manage information using multiple representations. The added functionality will support multiple coexisting representations of the same real-word phenomena (semantic flexibility), including representations of geographic data at multiple resolutions (cartographic flexibility). This will in particular make possible a semantically meaningful management of multiscale, integrated, and temporal geo-databases

A language and an execution model for the detection of active situations

This paper presents a thesis about a language and an execution model for the detection of situations aimed at reducing the complexity of active applications. This work has been motivated by the observation that in many cases, there is a gap between current tools that enable to react to a single event (following the ECA: Event – condition – action paradigm), and the reality, in which a single event may not require any reaction, however the reaction should be given to patterns over the event history. The concept of situation presented in this paper, extends the concept of composite event, in its expressive power, flexibility, and usability. This paper motivates the work, surveys other efforts in this are, and presents preliminary ideas for both the language and the execution model

Construction graphique d'entrepôts et de magasins de données

National audienceNowadays, decisional systems have became a significant research topic in databases. Data warehouses and data marts are the main elements of such systems. This paper presents our decisional support system. We present graphical interfaces which help the administrator to build data warehouses and data marts. We present a data warehouse building interface based on an object-oriented conceptual model. This model allows the warehouse data historisation at three levels: attribute, class and environment. Also, we present a data mart building interface which allows warehouse data to be reorganised through a multidimensional object-oriented model

On-line analytical processing in distributed data warehouses

The concepts of 'data warehousing' and 'on-line analytical processing' have seen a growing interest in the research and commercial product community. Today, the trend moves away from complex centralized data warehouses to distributed data marts integrated in a common conceptual schema. However, as the first part of this paper demonstrates, there are many problems and little solutions for large distributed decision support systems in worldwide operating corporations. After showing the benefits and problems of the distributed approach, this paper outlines possibilities for achieving performance in distributed online analytical processing. Finally, the architectural framework of the prototypical distributed OLAP system CUBESTAR is outlined

Using spatial-temporal maps for visualization of the karst development dynamics

Основная статьяThere is a problem of visualization dynamics of karst processes during territory monitoring. For this can be used geographic information system. All information on existing forms of karst processes can connected to the map based on the coordinates. But there is a need to include into GIS the information about the dynamics of the karst processes. There is a big problem to solve this task in traditional GIS. Development of karst processes has features that affect their visualization in GIS: the shape and the state of karst objects may change; existing karst forms can be replaced with new objects; the frequency of state changes and appearance of new objects is small; cartographic basis (map) may change as a result of the impact of natural phenomena and human activities. To solve the problem can be used spatial-temporal GIS. In paper the basic features of the karst processes development that affect their storage and display on maps are given. The questions of organization of karst processes dynamics visualization on the basis of spatial-temporal maps are presented. Practical issues of linking the objects in map, display of them geometry, determine temporal boundaries of objects existence are describes

Der Lehrstuhl Datenbank- und Informationssysteme der Universität Rostock

Im Jahr 2014 feierte der Lehrstuhl Datenbank- und Informationssysteme (LS DBIS) an der Universität Rostock sein zwanzigjähriges Bestehen. Zur Jubiläumsveranstaltung mit ehemaligen und aktuellen Studenten, Mitarbeitern, Kollegen und Kooperationspartnern wurde diverses Material aus 20 Jahren aufbereitet. In diesem Beitrag soll daraus ein Rückblick auf 20 Jahre Forschung und Lehre im Bereich Datenbank- und Informationssysteme sowie ein Ein- und Ausblick auf aktuelle Forschungsarbeiten gegeben werden