A Rule-Based, Integrated Modelling Approach for Object-Oriented Systems

AbstractIn this paper an integrated modelling approach for object-oriented systems is proposed. The integrated language consists of three layers. On the first layer UML class diagrams are used to define the structure of the modelled systems and OCL expressions specify queries, which do not modify the object configuration. On the second layer transformation rules model local state modifications of the system. On the third layer Nassi-Shneiderman diagrams describe complex control flows built over the rules and queries on the lower layers. The proposed integrated language is evaluated by a running example on modelling doubly linked lists and the mergesort algorithm

Graph Transformations for the Resource Description Framework

The Resource Description Framework (RDF) is a standard developed by the World Wide Web Consortium (W3C) to facilitate the representation and exchange of structured (meta-)data in the "SemanticWeb". While there is a large body of work dealing with inference on RDF, a concept for transformation and manipulation is still missing. Since RDF uses graphs as a formal basis, this paper proposes the use of algebraic graph transformations with their wealth of well-known constructions and results for this purpose. It turns out that RDF graphs are an interesting application area for graph transformation methods, where some significant differences to classical graphs yield practically relevant solutions for features like attribution, typing and globally unique nodes

Rule-Based Integration of Domain-Specific Modelling Languages

Domain-specific modelling languages (DSMLs) can increase the acceptance of (semi-)formal modelling techniques. They allow all stakeholders in an application domain to participate in the modelling process using notations that are close to their understanding of the domain. When several groups of stakeholders are concerned with a certain aspect of the modelled system, the question arises how different DSMLs can be integrated with respect to this aspect. In this paper, we propose rule-based transformations as a means to integrate heterogeneous DSMLs overlapping on dedicated aspects. We illustrate the approach by a running example of a small visual DSML for IT landscapes and a textual DSML for firewall configurations

Formal Modelling and Application of Graph Transformations in the Resource Description Framework

In dieser Arbeit wird eine Verbindung zwischen zwei Forschungsbereichen entwickelt. Auf der einen Seite ist das Resource Description Framework (RDF) die Basis des Semantic Web. Auf der anderen Seite hat die algebraische Graphtransformation eine lange Tradition darin, formal fundierte Modifikationskonzepte für Graphen und graphähnliche Strukturen zur Verfügung zu stellen. Durch den Entwurf eines algebraischen Transformationskonzepts für RDF werden die reichhaltigen theoretischen Ergebnisse der algebraischen Graphtransformation für die RDF-Welt nutzbar. Um dieses Ziel zu erreichen, wird zunächst die formale abstrakte Syntax und Semantik von RDF in der Sprache der Kategorientheorie, die bei Graphtransformationen intensiv genutzt wird, reformuliert. Dann wird ein abstraktes, kategorielles Transformations-Framework entwickelt, welches geeignet ist, anschließend durch RDF-Strukturen instanziiert zu werden. Dies ist notwendig, da keines der existierenden Frameworks in unmodifizierter Form anwendbar ist. Die hauptsächlichen theoretischen Ergebnisse sind eine sequenzielle Kompositionsoperation für Transformationsregeln und Theoreme, die die Möglichkeit zeigen, Transformationen entlang dieser sequenziell komponierten Regeln zu analysieren und synthetisieren. Diese Ergebnisse sind weiterhin ebenfalls für Transformationsregeln mit negativen Anwendungsbedingungen verfügbar. Die Anwendbarkeit des resultierenden Konzeptes für RDF-Graphtransformationen wird durch zwei Anwendungsszenarien gezeigt. Das eine ist eine klassische Semantic-Web-Anwendung, die bibliographische Metadaten verwaltet, während die andere RDF als abstrakte Syntax für domänenspezifische Modellierungssprachen verwendet.In this thesis, a connection between two areas of research is developed. On the one hand, the Resource Desription Framework (RDF) is the basis of the Semantic Web. On the other hand, algebraic graph transformation has a long history of providing formally well-founded modification concepts for various graph and graph-like structures. By designing an algebraic transformation approach for RDF, the rich theoretical results of algebraic graph transformation are made available to the RDF world. To achieve this goal, the formal abstract syntax and semantics of RDF is first reformulated in the language of category theory which is used heavily in graph transformation. Then, an abstract, categorical transformation framework is developed which is suitable for being afterwards instantiated by RDF structures. This is necessary since the existing frameworks are not applicable in an unmodified form. The main theoretical results are a sequential composition operation for transformation rules and theorems showing the possibility to analyse and synthesise transformations for these sequentially composed rules. Moreover, these results are also available for transformation rules with negative application conditions. The applicability of the resulting concept of RDF graph transformations is shown by two application scenarios. One is a classical Semantic Web application managing bibliographical metadata, while the other uses RDF as an abstract syntax for domain-specific modelling languages

Finitary M-adhesive categories

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Finitary M-adhesive categories are M-adhesive categories with finite objects only, where M-adhesive categories are a slight generalisation of weak adhesive high-level replacement (HLR) categories. We say an object is finite if it has a finite number of M-subobjects. In this paper, we show that in finitary M-adhesive categories we not only have all the well-known HLR properties of weak adhesive HLR categories, which are already valid for M-adhesive categories, but also all the additional HLR requirements needed to prove classical results including the Local Church-Rosser, Parallelism, Concurrency, Embedding, Extension and Local Confluence Theorems, where the last of these is based on critical pairs. More precisely, we are able to show that finitary M-adhesive categories have a unique ε'-M factorisation and initial pushouts, and the existence of an M-initial object implies we also have finite coproducts and a unique ε' -M pair factorisation. Moreover, we can show that the finitary restriction of each M-adhesive category is a finitary M-adhesive category, and finitarity is preserved under functor and comma category constructions based on M-adhesive categories. This means that all the classical results are also valid for corresponding finitary M-adhesive transformation systems including several kinds of finitary graph and Petri net transformation systems. Finally, we discuss how some of the results can be extended to non-M-adhesive categories

Finitary M-Adhesive Categories : Unabridged Version

Finitary M-adhesive categories are M-adhesive categories with finite objects only, where the notion M-adhesive category is short for weak adhesive high-level replacement (HLR) category. We call an object finite if it has a finite number of M-subobjects. In this paper, we show that in finitary M-adhesive categories we do not only have all the well-known properties of M-adhesive categories, but also all the additional HLR-requirements which are needed to prove the classical results for M-adhesive systems. These results are the Local Church-Rosser, Parallelism, Concurrency, Embedding, Extension, and Local Confluence Theorems, where the latter is based on critical pairs. More precisely, we are able to show that finitary M-adhesive categories have a unique E-M factorization and initial pushouts, and the existence of an M-initial object implies in addition finite coproducts and a unique E'-M' pair factorization. Moreover, we can show that the finitary restriction of each M-adhesive category is a finitary M-adhesive category and finitariness is preserved under functor and comma category constructions based on M-adhesive categories. This means that all the classical results are also valid for corresponding finitary M-adhesive systems like several kinds of finitary graph and Petri net transformation systems. Finally, we discuss how some of the results can be extended to non-M-adhesive categories

Correctness of Generalisation and Customisation of Concurrent Model Synchronisation Based on Triple Graph Grammars

Triple graph grammars (TGGs) have been successfully applied to specify and analyse bidirectional model transformations. Recently, a formal approach to concurrent model synchronisation has been presented, where a source and a target modification have to be synchronised simultaneously. In this approach, conflicts between the given and propagated source or target model modifications are taken into account. A semi-automatic conflict resolution strategy is proposed, where a formal resolution strategy can be combined with a user-specific strategy. Up to now, our approach requires deterministic propagation operations. In this paper, we want to relax this condition and also consider non-deterministic (conflicting) operations which might require backtracking. For optimisation, we propose to eliminate conflicts between the operational rules of a TGG using the concept of filter NACs. Nevertheless, concurrent synchronisation is non-deterministic from a user perspective: The user may choose between forward synchronisation and backward synchronisation. Moreover, the conflict resolution strategy may result in several solutions from which the user has to select the most adequate one. Hence, we discuss different kinds of customisation of the synchronisation process and explain the impacts of the different strategies

ngVLA Key Science Goal 5 Understanding the Formation and Evolution of Black Holes in the Era of Multi-Messenger Astronomy

The next-generation Very Large Array (ngVLA) will be a powerful telescope for finding and studying black holes across the entire mass range. High-resolution imaging abilities will allow the separation of low-luminosity black holes in the local Universe from background sources, thereby providing critical constraints on the mass function, formation, and growth of black holes. Its combination of sensitivity and angular resolution will provide new constraints on the physics of black hole accretion and jet formation. Combined with facilities across the spectrum and gravitational wave observatories, the ngVLA will provide crucial constraints on the interaction of black holes with their environments, with specific implications for the relationship between evolution of galaxies and the emission of gravitational waves from in-spiraling supermassive black holes and potential implications for stellar mass and intermediate mass black holes. The ngVLA will identify the radio counterparts to transient sources discovered by electromagnetic, gravitational wave, and neutrino observatories, and its high-resolution, fast-mapping capabilities will make it the preferred instrument to pinpoint electromagnetic counterparts to events such as supermassive black hole mergers. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment

Genome-wide identification and phenotypic characterization of seizure-associated copy number variations in 741,075 individuals

Copy number variants (CNV) are established risk factors for neurodevelopmental disorders with seizures or epilepsy. With the hypothesis that seizure disorders share genetic risk factors, we pooled CNV data from 10,590 individuals with seizure disorders, 16,109 individuals with clinically validated epilepsy, and 492,324 population controls and identified 25 genome-wide significant loci, 22 of which are novel for seizure disorders, such as deletions at 1p36.33, 1q44, 2p21-p16.3, 3q29, 8p23.3-p23.2, 9p24.3, 10q26.3, 15q11.2, 15q12-q13.1, 16p12.2, 17q21.31, duplications at 2q13, 9q34.3, 16p13.3, 17q12, 19p13.3, 20q13.33, and reciprocal CNVs at 16p11.2, and 22q11.21. Using genetic data from additional 248,751 individuals with 23 neuropsychiatric phenotypes, we explored the pleiotropy of these 25 loci. Finally, in a subset of individuals with epilepsy and detailed clinical data available, we performed phenome-wide association analyses between individual CNVs and clinical annotations categorized through the Human Phenotype Ontology (HPO). For six CNVs, we identified 19 significant associations with specific HPO terms and generated, for all CNVs, phenotype signatures across 17 clinical categories relevant for epileptologists. This is the most comprehensive investigation of CNVs in epilepsy and related seizure disorders, with potential implications for clinical practice