Karl Neumann

Handling changes of database schemas and corresponding ontologies

Currently, knowledge from biological research is stored in hundreds of databases, counting only public accessible ones. Finding specific data in these is a challenging task which can be supported by ontologies describing them. The maintenance of a corresponding ontology is time consuming manual work, because research database schemas change rapidly. Our project will reduce the work by automating tasks, like a generation process and applying schema changes to the corresponding ontology. We call the proposed method coevolution, because database schema and ontology are allowed to evolve independently without ever losing their connection to each other. Our method consists of initial ontology generation, manual annotation and change propagation steps.

Increasing Reusability in Information Systems Development by Applying Generic Methods

Increasing the reuse of parts of the specification and implementation of complex software systems, as for example information systems, may lead to substantial progress in the development process. This paper focuses on reusing parts of specifications with the help of generic methods and explores two aspects: the parameterization concepts of the languages UML and Troll, and how formal parameters in such concepts can be restricted if needed.

Keeping track of changes in database schemas and related ontologies

Connecting scientific databases is a challenging task which can be supported by ontologies describing them on a semantical level. Unfortunately, ontologies for databases are rarely used, because schemas of research databases change rapidly while the ontologies grow as well. Maintaining the connection between both is time consuming manual work. Therefore it is worthwhile to reduce the required work by automating tasks. We propose an approach that allows the database schema and the ontology to change and evolve, without ever losing their connection to each other. This is done by mapping database schemas to ontologies, enriching these ontologies with semantical information and transfering schema changes to the ontology

Modellierung und kartographische Visualisierung von Geodaten mit XML-basierten Sprachen

ZusammenfassungMit den XML-basierten Sprachen GML, XSLT und SVG lassen sich Geodaten nicht nur anwendungsorientiert modellieren, sondern auch kartenähnlich visualisieren. In dieser Fallstudie zeigen wir das, indem wir realistische Geodatenbestände der Landesvermessungsämter zunächst mit der Geography Markup Language (GML) nachmodellieren. So mit GML strukturierte Daten werden dann mit der Extensible Stylesheet Language for Transformation (XSLT) auf Elemente der Sprache Scalable Vector Graphics (SVG) abgebildet. Dabei wird der Prozess der kartografischen Visualisierung durch XSLT-Konstrukte modelliert und auch gleichzeitig implementiert. Als Ergebnis erhalten wir Grafiken, die den entsprechenden Karten der Landesämter zumindest nicht unähnlich sind. AbstractUsing the XML-based languages GML, XSLT and SVG, we modeled German geo data and also visualized it in map-like graphics. This case study shows the feasibility of that approach, by modelling the data with the Geography Markup Language (GML). Then, the GML-structured data is mapped with the Extensible Stylesheet Language for Transformation (XSLT) to elements of the language Scalable Vector Graphics (SVG). The process of cartographical visualization is thus modelled through XSLT-constructs and at same time also implemented. The results are graphics, which share close ressemblance to the corresponding maps of the official offices.

Regelorientierte Erzeugung von Karten-Entwürfen auf Geowissenschaftlichen Datenbanken

In der vorliegenden Arbeit werden Sprachmittel zur Definition von Regeln zur Kartenerzeugung und deren Umsetzung auf die Benutzerschnittstelle eines geowissenschaftliehen Datenbanksystems vorgestellt. Diese Regeln legen die Darstellung von Klassen geowissen- schaftlicher Objekte in ganzen Kartenarten fest. Der Entwurf einer konkreten Karte kann dann weitgehend automatisch, regelgesteuert durchgefuhrt werden.

A Displacement Method for Maps Showing Dense Sets of Points of Interest

In the past, point data only play a minor role in map generalization, as points are either already the result of generalization or are used for objects which are only shown on large scale maps. Now, with the growing availability of web mapping services the role of point data has changed: Besides route planning, the most common function of web maps is the visualization of user queries for points of interest. The limited size of commonly used displays often results in a smaller scale as would be appropriate for the maps content. The state of the art to resolve occurring cluttered point sets, is on the one hand interactivity and on the other hand the selection of points. Thus, often the available space is not optimally used. Therefore, we propose a displacement method to improve the readability of dense sets of points of interest.

Conceptual modeling of mobile object systems: language constructs for distinguishing between mobile and stationary subsystems

A couple of specification and modeling languages dedicated to the particularities of mobile systems have been developed as mobile hardware and software gain wide acceptance. Though these languages facilitate describing systems of mobile objects at different levels of abstraction, they do not allow to distinguish between the ever-mobile units and those which provide the fixed subsystems as the context for the mobile entities. However, as this is an essential distinction for many scenarios, in this article we present some suitable constructs as an extension of an already existing specification language from the area of information retrieval.

Techniques and language constructs for developing generic informations systems: a case study

When creating a family of systems, i.e. several systems of similar type which differ within some aspects, it is desirable to be able to express these differences already at the level of the specification, and to automatically obtain systems from it which are ready to run. The use of generic methods may lead to substantial progress in this area. This report explores two aspects: parameterization concepts at the specification level, which can be used to describe variants of a system, and generator programs, which produce runnable systems from prefabricated components.

Towards sentiment-driven maps showing touristic attractiveness

User generated texts on tourism-related social network sites do not only contain factual information, but also valuable opinions and ratings of locations. Nevertheless, most maps on these sites only show markers where something described in a user generated text is located. In particular, no further information is derived from the text and displayed on the maps. Moreover, generalization operations are not employed, although in most cases aggregation and displacement of the user generated content would be necessary to achieve more readable maps. Therefore, we propose a method which automatically creates user-sentiment enriched maps. We use natural language processing tools in order to mine user sentiments for specific places from user generated texts and we propose specially designed point symbols which represent the corresponding mined user sentiment for each location. Additionally, we propose a heuristic, based on Voronoi diagrams, which slightly displaces the aforementioned symbols in case they are very close. This makes the provided map easier to read.

Entwurf eines Datenbank-Prototyps für geowissenschaftliche Anwendungen

In dieser Arbeit wird die Konzeption eines Nichtstandard-Datenbanksystems fur geowissenschaftliche Anwendungen vorgestellt. Das System bietet eine objektorientierte Datenbanksprache mit einer erweiterbaren Menge von geometrischen Datentypen; in Anwendungsprogrammen ist die Datenbanksprache als eingebettete Datenteilsprache verfugbar, wobei von der Datenbank gelesene Objektmengen nach einem Abstrakten-Datentyp-Ansatz manipuliert werden konnen. Ein spezieller NF2-Datenbankkern ist als Grundlage fur eine effiziente Implementierung vorgesehen.