Parallel Graph Grammars with Instantiation Rules Allow Efficient Structural Factorization of Virtual Vegetation

Parallel rewriting of typed attributed graphs, based on the single-pushout approach extended by connection transformations, serves as the backbone of the multi-paradigm language XL, which is widely used in functional-structural plant modelling. XL allows to define instantiation rules, which enable an instancing of graphs at runtime for frequently occurring substructures, e.g., in 3-d models of botanical trees. This helps to save computer memory during complex simulations of vegetation structure. Instantiation rules can be called recursively and with references to graph nodes, thus providing a unifying formal framework for various concepts from the literature: object instancing, structural factorization, Xfrog multiplier nodes, L-systems with interpretation. We give simple examples and measure the computation time for an idealized growing virtual plant, taken from the GreenLab model, in its implementation with instantiation rules in XL, compared to a version without instantiation rules

Realization and Extension of the Xfrog Approach for Plant Modelling in the Graph-Grammar Based Language XL

Two well-known approaches for modelling virtual vegetation are grammar-based methods (L-systems) and the Xfrog method, which is based on graph transformations expanding "multiplier" nodes. We show that both approaches can be unified in the framework of "relational growth grammars", a variant of parallel graph grammars. We demonstrate this possibility and the synergistic benefits of the combination of both methods at simple plant models which were processed using our open-source software GroIMP

A Language-centered Approach to support environmental modeling with Cellular Automata

Die Anwendung von Methodiken und Technologien aus dem Bereich der Softwaretechnik auf den Bereich der Umweltmodellierung ist eine gemeinhin akzeptierte Vorgehensweise. Im Rahmen der "modellgetriebenen Entwicklung"(MDE, model-driven engineering) werden Technologien entwickelt, die darauf abzielen, Softwaresysteme vorwiegend auf Basis von im Vergleich zu Programmquelltexten relativ abstrakten Modellen zu entwickeln. Ein wesentlicher Bestandteil von MDE sind Techniken zur effizienten Entwicklung von "domänenspezifischen Sprachen"( DSL, domain-specific language), die auf Sprachmetamodellen beruhen. Die vorliegende Arbeit zeigt, wie modellgetriebene Entwicklung, und insbesondere die metamodellbasierte Beschreibung von DSLs, darüber hinaus Aspekte der Pragmatik unterstützen kann, deren Relevanz im erkenntnistheoretischen und kognitiven Hintergrund wissenschaftlichen Forschens begründet wird. Hierzu wird vor dem Hintergrund der Erkenntnisse des "modellbasierten Forschens"(model-based science und model-based reasoning) gezeigt, wie insbesondere durch Metamodelle beschriebene DSLs Möglichkeiten bieten, entsprechende pragmatische Aspekte besonders zu berücksichtigen, indem sie als Werkzeug zur Erkenntnisgewinnung aufgefasst werden. Dies ist v.a. im Kontext großer Unsicherheiten, wie sie für weite Teile der Umweltmodellierung charakterisierend sind, von grundsätzlicher Bedeutung. Die Formulierung eines sprachzentrierten Ansatzes (LCA, language-centered approach) für die Werkzeugunterstützung konkretisiert die genannten Aspekte und bildet die Basis für eine beispielhafte Implementierung eines Werkzeuges mit einer DSL für die Beschreibung von Zellulären Automaten (ZA) für die Umweltmodellierung. Anwendungsfälle belegen die Verwendbarkeit von ECAL und der entsprechenden metamodellbasierten Werkzeugimplementierung.The application of methods and technologies of software engineering to environmental modeling and simulation (EMS) is common, since both areas share basic issues of software development and digital simulation. Recent developments within the context of "Model-driven Engineering" (MDE) aim at supporting the development of software systems at the base of relatively abstract models as opposed to programming language code. A basic ingredient of MDE is the development of methods that allow the efficient development of "domain-specific languages" (DSL), in particular at the base of language metamodels. This thesis shows how MDE and language metamodeling in particular, may support pragmatic aspects that reflect epistemic and cognitive aspects of scientific investigations. For this, DSLs and language metamodeling in particular are set into the context of "model-based science" and "model-based reasoning". It is shown that the specific properties of metamodel-based DSLs may be used to support those properties, in particular transparency, which are of particular relevance against the background of uncertainty, that is a characterizing property of EMS. The findings are the base for the formulation of an corresponding specific metamodel- based approach for the provision of modeling tools for EMS (Language-centered Approach, LCA), which has been implemented (modeling tool ECA-EMS), including a new DSL for CA modeling for EMS (ECAL). At the base of this implementation, the applicability of this approach is shown

24th International Conference on Information Modelling and Knowledge Bases

In the last three decades information modelling and knowledge bases have become essentially important subjects not only in academic communities related to information systems and computer science but also in the business area where information technology is applied. The series of European – Japanese Conference on Information Modelling and Knowledge Bases (EJC) originally started as a co-operation initiative between Japan and Finland in 1982. The practical operations were then organised by professor Ohsuga in Japan and professors Hannu Kangassalo and Hannu Jaakkola in Finland (Nordic countries). Geographical scope has expanded to cover Europe and also other countries. Workshop characteristic - discussion, enough time for presentations and limited number of participants (50) / papers (30) - is typical for the conference. Suggested topics include, but are not limited to: 1. Conceptual modelling: Modelling and specification languages; Domain-specific conceptual modelling; Concepts, concept theories and ontologies; Conceptual modelling of large and heterogeneous systems; Conceptual modelling of spatial, temporal and biological data; Methods for developing, validating and communicating conceptual models. 2. Knowledge and information modelling and discovery: Knowledge discovery, knowledge representation and knowledge management; Advanced data mining and analysis methods; Conceptions of knowledge and information; Modelling information requirements; Intelligent information systems; Information recognition and information modelling. 3. Linguistic modelling: Models of HCI; Information delivery to users; Intelligent informal querying; Linguistic foundation of information and knowledge; Fuzzy linguistic models; Philosophical and linguistic foundations of conceptual models. 4. Cross-cultural communication and social computing: Cross-cultural support systems; Integration, evolution and migration of systems; Collaborative societies; Multicultural web-based software systems; Intercultural collaboration and support systems; Social computing, behavioral modeling and prediction. 5. Environmental modelling and engineering: Environmental information systems (architecture); Spatial, temporal and observational information systems; Large-scale environmental systems; Collaborative knowledge base systems; Agent concepts and conceptualisation; Hazard prediction, prevention and steering systems. 6. Multimedia data modelling and systems: Modelling multimedia information and knowledge; Contentbased multimedia data management; Content-based multimedia retrieval; Privacy and context enhancing technologies; Semantics and pragmatics of multimedia data; Metadata for multimedia information systems. Overall we received 56 submissions. After careful evaluation, 16 papers have been selected as long paper, 17 papers as short papers, 5 papers as position papers, and 3 papers for presentation of perspective challenges. We thank all colleagues for their support of this issue of the EJC conference, especially the program committee, the organising committee, and the programme coordination team. The long and the short papers presented in the conference are revised after the conference and published in the Series of “Frontiers in Artificial Intelligence” by IOS Press (Amsterdam). The books “Information Modelling and Knowledge Bases” are edited by the Editing Committee of the conference. We believe that the conference will be productive and fruitful in the advance of research and application of information modelling and knowledge bases. Bernhard Thalheim Hannu Jaakkola Yasushi Kiyok

The 1995 Goddard Conference on Space Applications of Artificial Intelligence and Emerging Information Technologies

This publication comprises the papers presented at the 1995 Goddard Conference on Space Applications of Artificial Intelligence and Emerging Information Technologies held at the NASA/Goddard Space Flight Center, Greenbelt, Maryland, on May 9-11, 1995. The purpose of this annual conference is to provide a forum in which current research and development directed at space applications of artificial intelligence can be presented and discussed

Maritime Augmented Reality mit a prioriWissen aus Seekarten

The main objective of this thesis is to provide a concept to augment mar- itime sea chart information into the camera view of the user. The benefit is the simpler navigation due to the offered 3D information and the overlay onto the real 3D environment. In the maritime context special conditions hold. The sensor technologies have to be reliable in the environment of a ship’s ferrous construction. The aug- mentation of the objects has to be very precise due to the far distances of observable objects on the sea surface. Furthermore, the approach has to be reliable due to the wide range of light conditions. For a practical solution, the system has to be mobile, light-weight and with a real-time performance. To achieve this goal, the requirements are set, the possible measurement units and the data base structure are presented. First, the requirements are analyzed and a suitable system is designed. By the combination of proper sensor techniques, the local position and orienta- tion of the user can be estimated. To verify the concept, several prototypes with exchangeable units have been evaluated. This first concept is based on a marker-based approach which leads to some drawbacks. To overcome the drawbacks, the second aspect is the improvement of the sys- tem and the analysis of markerless approaches. One possible strategy will be presented. The approach uses the statistical technique of Bayesian networks to vote for single objects in the environment. By this procedure it will be shown, that due to the a priori information the underlying sea chart system has the most benefit. The analysis of the markerless approach shows, that the sea charts structure has to be adapted to the new requirements of interactive 3D augmentation scenes. After the analysis of the chart data concept, an approach for the optimization of the charts by building up an object-to-object topology within the charts data and the Bayesian object detection approach is presented. Finally, several evaluations show the performance of the imple- mented evaluation application.Diese Arbeit stellt ein Konzept zur Verfügung, um Seekarteninformationen in eine Kamera so einzublenden, dass die Informationen lagerichtig im Sichtfeld des Benutzers erscheinen. Der Mehrwert ist eine einfachere Navigation durch die Nutzung von 3D-Symbolen in der realen Umgebung. Im maritimen Umfeld gelten besondere Anforderungen an die Aufgabenstellung. Die genutzten Sensoren müssen in der Lage sein, robuste Daten in Anwesenheit der eisenhaltigen Materialien auf dem Schiff zu liefern. Die Augmentierung muss hoch genau berechnet werden, da die beobachtbaren Objekte zum Teil sehr weit entfernt auf der Meeresoberfläche verteilt sind. Weiterhin gelten die Bedingungen einer Außenumgebung, wie variierende Wetter- und Lichtbedingungen. Um eine praktikable Anwendung gewährleisten zu können, ist ein mobiles, leicht-gewichtiges und echtzeitfähiges System zu entwickeln. In dieser Arbeit werden die Anforderungen gesetzt und Konzepte für die Hardware- und Softwarelösungen beschrieben. Im ersten Teil werden die Anforderungen analysiert und ein geeignetes Hardwaresystem entwickelt. Durch die passende Kombination von Sensortechnologien kann damit die lokale Position und Orientierung des Benutzers berechnet werden. Um das Konzept zu evaluieren sind verschiedene modulare Hardware- und Softwarekonzepte als Prototypen umgesetzt worden. Das erste Softwarekonzept befasst sich mit einem markerbasierten Erkennungsalgorithmus, der in der Evaluation einige Nachteile zeigt. Dementsprechende Verbesserungen wurden in einem zweiten Softwarekonzept durch einen markerlosen Ansatz umgesetzt. Dieser Lösungsansatz nutzt Bayes'sche Netzwerke zur Erkennung einzelner Objekte in der Umgebung. Damit kann gezeigt werden, dass mit der Hilfe von a priori Informationen die dem System zugrunde liegenden Seekarten sehr gut zu diesem Zweck genutzt werden können. Die Analyse des Systemkonzeptes zeigt des weiteren, dass die Datenstruktur der Seekarten für die Anforderungen einer interaktiven, benutzergeführten 3D- Augmentierungsszene angepasst werden müssen. Nach der ausführlichen Analyse des Seekarten-Datenkonzeptes wird ein Lösungsansatz zur Optimierung der internen Seekartenstruktur aufgezeigt. Dies wird mit der Erstellung einer Objekt-zu-Objekt-Topologie in der Datenstruktur und der Verbindung zum Bayes'schen Objekterkennungsalgorithmus umgesetzt. Anschließend zeigen Evaluationen die Fähigkeiten des endgültigen Systems