In model-driven development (MDD), domain-specific modeling languages (DSMLs) are used as tailor-made software languages targeting dedicated application domains. Due to the narrow domain coverage of DSMLs, demands to integrate their individual functionality into a consolidated DSML arise (e.g., developing a software product combining two or more pre-existing DSMLs). However, in order to realize the benefits of integrated DSMLs, it must be ensured that the integrated DSML is correctly implemented and behaves as specified. To support the integration and the test of DSMLs, this thesis presents an approach targeting the Meta Object Facility (MOF) and the Unified Modeling Language (UML)- a metamodeling infrastructure frequently employed for the MDD of software systems. The integration of DSMLs is based on a rewriting technique for model-to-text (M2T) transformations. This method allows for the reuse as well as for the automatic refactoring of M2T transformation templates to fix important syntactical mismatches between templates and the integrated DSML. To test an integrated DSML, scenarios are used to define domain requirements on an abstract level (via structured text descriptions). In a subsequent step, executable scenario tests are derived from the requirements-level scenarios. These executable scenario specifications are then employed to test the integrated DSML for compliance with corresponding domain requirements. Empirical evaluations of the approach (case studies, controlled experiment) demonstrate its successful application, collect evidence for its usefulness, and quantify its benefits. The integrated proof-of-concept implementations build on the Eclipse Modeling Framework (EMF), making use of and extending well-known Eclipse-based projects. All accompanying developments are placed into the public domain as free/libre open source software. Within the framework of this thesis, research results were originally published as individual contributions (workshop, conference, and journal articles). All research contributions are results of applying a design science research approach. (author's abstract)

In model-driven development (MDD), domain-specific modeling languages (DSMLs) act as a communication vehicle for aligning the requirements of domain experts with the needs of software engineers. With the rise of the UML as a de facto standard, UML/MOF-based DSMLs are now widely used for MDD. This paper documents design decisions collected from 90 UML/MOF-based DSML projects. These recurring design decisions were gained, on the one hand, by performing a systematic literature review (SLR) on the development of UML/MOF-based DSMLs. Via the SLR, we retrieved 80 related DSML projects for review. On the other hand, we collected decisions from developing ten DSML projects by ourselves. The design decisions are presented in the form of reusable decision records, with each decision record corresponding to a decision point in DSML development processes. Furthermore, we also report on frequently observed (combinations of) decision options as well as on associations between options which may occur within a single decision point or between two decision points. This collection of decision-record documents targets decision makers in DSML development (e.g., DSML engineers, software architects, domain experts). (authors' abstract) / Series: Technical Reports / Institute for Information Systems and New Media

In model-driven development (MDD), domain-specific modeling languages (DSMLs) act as a communication vehicle for aligning the requirements of domain experts with the needs of software engineers. With the rise of the UML as a de facto standard, UML/MOF-based DSMLs are now widely used for MDD. This paper documents design decisions collected from 90 UML/MOF-based DSML projects. These recurring design decisions were gained, on the one hand, by performing a systematic literature review (SLR) on the development of UML/MOF-based DSMLs. Via the SLR, we retrieved 80 related DSML projects for review. On the other hand, we collected decisions from developing ten DSML projects by ourselves. The design decisions are presented in the form of reusable decision records, with each decision record corresponding to a decision point in DSML development processes. Furthermore, we also report on frequently observed (combinations of) decision options as well as on associations between options which may occur within a single decision point or between two decision points. This collection of decision-record documents targets decision makers in DSML development (e.g., DSML engineers, software architects, domain experts). / Series: Technical Reports / Institute for Information Systems and New Media

In model-driven development (MDD), domain-specific modeling languages (DSMLs) act as a communication vehicle for aligning the requirements of domain experts with the needs of software engineers. With the rise of the UML as a de facto standard, UML/MOF-based DSMLs are now widely used for MDD. This paper documents design decisions collected from 90 UML/MOF-based DSML projects. These recurring design decisions were gained, on the one hand, by performing a systematic literature review (SLR) on the development of UML/MOF-based DSMLs. Via the SLR, we retrieved 80 related DSML projects for review. On the other hand, we collected decisions from developing ten DSML projects by ourselves. The design decisions are presented in the form of reusable decision records, with each decision record corresponding to a decision point in DSML development processes. Furthermore, we also report on frequently observed (combinations of) decision options as well as on associations between options which may occur within a single decision point or between two decision points. This collection of decision-record documents targets decision makers in DSML development (e.g., DSML engineers, software architects, domain experts). (authors' abstract) / Series: Technical Reports / Institute for Information Systems and New Media

In the process of model-driven development (MDD) of software artifacts, domain-specific modeling languages (DSMLs) are an integral part. They act as the communication vehicle for aligning the requirements of the domain expert with the needs of the software engineer. With the rise of the UML as de facto standard for modeling software systems, MOF/UML-based DSMLs are now widely used for MDD. This paper documents design decisions from ten DSML projects which are based on the MOF/UML and which we conducted over the last years. We present our experiences in the form of reusable decision templates for all decision points detected in each phase of the DSML development process. Furthermore, we report also on identified decision dependencies which may occur within a single decision or between two decisions. (author's abstract) / Series: Technical Reports / Institute for Information Systems and New Media

Es wird ein selbst entwickeltes Programm für Personalcomputer zur Simulation eines kieferorthopädischen Setups vorgestellt. Das Programm arbeitet mit einem Beispieldatensatz, der mikroskopisch gewonnen wurde. Mit dem Programm "VirtSet" lassen sich Zähne unabhängig voneinander positionieren, da sie sich auf eigene Koordinatensysteme beziehen. Die Ausrichtungen dieser Koordinatensysteme entsprechen den zahnärztlichen Richtungsbezeichnungen. Das Programm bietet eine halbautomatische Positionierung zu den mesialen und distalen Nachbarzähnen und zu den Antagonisten an. Das Programm erlaubt es, eine Zahnstellung mit mindestens vier antagonistischen Kontaktpunkten zu berechnen. Befinden sich beim Positionieren der Zähne Wurzelanteile außerhalb der Alveolarknochen, so wird dies dargestellt. Ferner wird ein Werkzeug zur exakten Positionierung der Zähne angeboten. Man kann die Zähne derart positionieren, daß sich Zahnanteile überlappen, und diese dann in einem speziellen Programmteil strippen. Zähne lassen sich extrahieren. Alle Änderungen an den Zähnen und deren Stellungen lassen sich rückgängig machen. Es wird ein halbindividueller Artikulator simuliert, mit dem man Protrusions-, Laterotrusions- und Okklusionsbewegungen realitätsnah darstellen kann. Mit virtuellem Kontaktpapier verschiedener Stärke lassen sich unterschiedliche Kontaktsituationen darstellen. Die Ausgabe erfolgt am Bildschirm in photorealistischer Darstellung. Es lassen sich diverse Einstellungen vornehmen, so daß man verschiedene Flächenarten wie zum Beispiel Zahnkronen-, Wurzel-, Kontaktpunkt- oder Artikulationsflächen differenzieren kann. Der Artikulator läßt sich von verschiedenen Seiten betrachten. Es lassen sich Bereiche unbegrenzt vergrößern und verkleinern. Die Darstellung auf dem Bildschirm läßt sich auf einem Drucker ausgeben, ebenso die Maße der durchgeführten Rotationen und Verschiebungen bezogen auf die zahn- und kieferspezifischen Achsen. Die Genauigkeit der Berechnungen liegt bei einem Mikrometer. Download des Computerprogramms für Windows95/98 / A computer program for simulating an orthodontic set up is presented. It seeks to offer a precise and practical contribution to computer-animated tools for orthodontics. The program is based on an exemplary set of data which was obtained microscopically. As a special feature, the teeth can be positioned independently as they refer to their own coordinate system. The alignments correspond to the dental nomenclature, for instance mesial, oral, apical. Moreover, antagonists and neighbouring teeth can be positioned semi-automatically. It is possible to calculate and present a minimum of four antagonistic contact points for each pair of teeth. If parts of the roots are outside the alveolar bone these are illustrated graphically. As another feature, the program offers a tool for an exact positioning of the teeth. Teeth can be positioned in an overlapping arrangement and subsequently can be stripped interdentally. The user can also extract teeth. Any changes of teeth and their positions can be reversed. Moreover the program allows to simulate a semi-individual articulator depicting protrusive, laterotrusive and occlusive movements authentically. The user can identify different contact points with the aid of virtual articulation foil. Besides, the program offers several application-oriented features: All computer-animated pictures have photographic qualities. That allows differentiations between various surface areas, such as crown, root, occlusal contact and articulation surfaces. The articulator can be looked at from different points of view. All areas can be zoomed in and out without limitations. Both the depictions and the measures of taken rotations related to the axes of individual teeth can be printed in full. The precision of all calculations is about one micrometer. Download the Computerprogram for MS-Windows95/98

Der Trend zu immer mehr parallelen Recheneinheiten innerhalb eines Prozessors stellt an die Softwareentwicklung neue Herausforderungen. Um die vorhandenen Ressourcen auszulasten und die stetige Steigerung der Parallelität in einen Leistungszuwachs umzusetzen, muss Software von der sequentiellen Verarbeitung in eine hochgradig parallele Verarbeitung übergehen. Diese Arbeit untersucht, wie solch eine parallele Verarbeitung in Bezug auf Relationale Datenbankmanagementsysteme umzusetzen ist. Dazu wird zunächst der gesamte Prozess der Anfragebearbeitung betrachtet und vier Problembereiche identifiziert, die für das Ziel der parallelen Anfragebearbeitung auf Mehrkern-Rechnerarchitekturen maßgeblich sind. Diese Bereiche sind die Hardware selbst, das physische Datenmodell sowie die Anfrageausführung und -optimierung. Diese vier Bereiche werden innerhalb eines Rahmenwerkes betrachtet. Nach einer Einführung, wird sich die Arbeit zunächst mit Grundlagen befassen. Dazu werden die Hardwarebestandteile Speicher und Prozessor betrachtet und ihre Funktionsweise erläutert. Auf diesem Wissen aufbauend, wird ein Hardwaremodell definiert. Es ermöglicht eine von der jeweiligen Hardwarearchitektur unabhängige Softwareentwicklung, ohne den Verlust an Funktionalität und Leistung. Im Weiteren wird das physische Datenmodell untersucht und analysiert, wie das physische Datenmodell eine optimale Anfrageausführung unterstützen kann. Die verwendeten Datenstrukturen müssen dafür einen effizienten und parallelen Zugriff erlauben. Die Analyse führt zur Entwicklung eines neuartigen Indexes, der die datenparallele Abarbeitung nutzt. Gefolgt wird dieser Teil von der Anfrageausführung, in der ein neues Anfrageausführungsmodell entwickelt wird, das auf der Verwendung des Taskkonzepts beruht und eine hohe und sehr leicht gewichtige Parallelität erlaubt. Den Abschluss stellt die Anfrageoptimierung dar, worin verschiedene Ideen für die Optimierung der Ressourcenverwaltung präsentiert werden. / The upcoming generation of many-core architectures poses several new challenges for software development: Software design and software implementation has to change from sequential execution to a highly parallel execution, such that it takes full advantage of the steadily growing number of cores on a single processor. With this thesis, we investigate such highly parallel program execution in the context of relational database management systems (RDBMSs). We consider the complete process of query processing and identify four problem areas which are crucial for efficient parallel query processing on many-core architectures. These four areas are: Hardware, physical data model, query execution, and query optimization. Furthermore, we present a framework which covers all four parts, one after another. First, we give a detailed survey of computer hardware with a special focus on memory and processors. Based on this survey we propose a hardware model. Our abstraction aims to simplify the task of software development on many-core hardware. Based on the hardware model, we investigate physical data models and evaluate how the physical data model may support optimal query execution by providing efficient and parallelizable data structures. Additionally, we design a new index structure that utilizes data parallel execution by using SIMD operations. The next layer within our framework is query execution, for which we present a new task based query execution model. Our query execution model allows for a lightweight parallelism. Finally, we cover query optimization by explaining approaches for optimizing resource utilization on a query local point of view as well as query global point of view.

Background: A key idea of feature orientation is to decompose a software product line along the features it provides. Feature decomposition is orthogonal to object-oriented decomposition it crosscuts the underlying package and class structure. It has been argued often that feature decomposition improves system structure (reduced coupling, increased cohesion). However, recent empirical findings suggest that this is not necessarily the case, which is the motivation for our empirical investigation. Aim: In fact, there is little empirical evidence on how the alternative decompositions of feature orientation and object orientation compare to each other in terms of their association with observable properties of system structure (coupling, cohesion). This motivated us to empirically investigate and compare the properties of three decompositions (object-oriented, feature-oriented, and their intersection) of 28 feature-oriented software product lines. Method: In an exploratory, observational study, we quantify internal attributes, such as import coupling and cohesion, to describe and analyze the different decompositions of a feature-oriented product line in a systematic, reproducible, and comparable manner. For this purpose, we use three established software measures (CBU, IUD, EUD) as well as standard distribution statistics (e.g., Gini coefficient). Results: First, feature decomposition is associated with higher levels of structural coupling in a product line than a decomposition into classes. Second, although coupling is concentrated in feature decompositions, there are not necessarily hot-spot features. Third, the cohesion of feature modules is not necessarily higher than class cohesion, whereas feature modules serve more dependencies internally than classes. Fourth, coupling and cohesion measurement show potential for sampling optimization in complex static and dynamic product-line analyses (product-line type checking, feature-interaction detection). Conclusions: Our empirical study raises critical questions about alleged advantages of feature decomposition. At the same time, we demonstrate how the measurement of structural attributes can facilitate static and dynamic analyses of software product lines. (authors' abstract) / Series: Technical Reports / Institute for Information Systems and New Media

Background: A key idea of feature orientation is to decompose a software product line along the features it provides. Feature decomposition is orthogonal to object-oriented decomposition it crosscuts the underlying package and class structure. It has been argued often that feature decomposition improves system structure (reduced coupling, increased cohesion). However, recent empirical findings suggest that this is not necessarily the case, which is the motivation for our empirical investigation. Aim: In fact, there is little empirical evidence on how the alternative decompositions of feature orientation and object orientation compare to each other in terms of their association with observable properties of system structure (coupling, cohesion). This motivated us to empirically investigate and compare the properties of three decompositions (object-oriented, feature-oriented, and their intersection) of 28 feature-oriented software product lines. Method: In an exploratory, observational study, we quantify internal attributes, such as import coupling and cohesion, to describe and analyze the different decompositions of a feature-oriented product line in a systematic, reproducible, and comparable manner. For this purpose, we use three established software measures (CBU, IUD, EUD) as well as standard distribution statistics (e.g., Gini coefficient). Results: First, feature decomposition is associated with higher levels of structural coupling in a product line than a decomposition into classes. Second, although coupling is concentrated in feature decompositions, there are not necessarily hot-spot features. Third, the cohesion of feature modules is not necessarily higher than class cohesion, whereas feature modules serve more dependencies internally than classes. Fourth, coupling and cohesion measurement show potential for sampling optimization in complex static and dynamic product-line analyses (product-line type checking, feature-interaction detection). Conclusions: Our empirical study raises critical questions about alleged advantages of feature decomposition. At the same time, we demonstrate how the measurement of structural attributes can facilitate static and dynamic analyses of software product lines. (authors' abstract) / Series: Technical Reports / Institute for Information Systems and New Media

Domänenspezifische Sprachen (DSLs) sind Software-Sprachen, die speziell für bestimmte Anwendungsdomänen entwickelt wurden. Mithilfe von DSLs können Domänenexperten ihr Domänenwissen auf einem hohen Abstraktionsniveau beschreiben. Wie andere Software-Sprachen auch, benötigen DSLs Sprachwerkzeuge, die Assistenz bei der Erstellung und Verarbeitung von domänenspezifischen Modellen bieten. Eine domänenspezifische Werkbank (DSW) ist ein Software-Werkzeug, welches mehrere solcher Sprachwerkzeuge für eine DSL miteinander integriert. Existierende Werkzeuge, die es erlauben eine DSW aufgrund der Beschreibung einer DSL automatisch generieren zu lassen, unterstützen jedoch nicht die Beschreibung und Generierung von editierbaren Sichten. Eine Sicht ist ein Teil einer DSW, der nur einen bestimmten Aspekt eines Modells darstellt. Diese Dissertation stellt spezielle Modelltransformationssprachen (MTLs) vor, mit denen die Synchronisation von Sichten in einer generierten DSW beschrieben werden kann. Dadurch können DSWs mit editierbaren Sichten mittels existierender Werkzeuge zur Generierung von Sprachwerkzeugen erstellt werden. Dafür wird eine DSW für die Nanophysik-Domäne sowie eine Taxonomie von Synchronisationstypen vorgestellt, welche es erlaubt genau zu bestimmen, welche Art von Modelltransformationen für die Synchronisation von Sichten in dieser Werkbank benötigt werden. Entsprechend dieser Anforderungen werden zwei MTLs entwickelt. Insbesondere wird eine bidirektionale MTL entwickelt. Mit solch einer Sprache kann man eine Relation, welche definiert ob zwei Modelle synchron sind, so beschreiben, dass die entsprechende Synchronisationslogik automatisch abgeleitet werden kann. Die gezeigten MTLs werden als interne DSLs - das heißt eingebettet als ausdrucksstarke Bibliotheken - in der Programmiersprache Scala implementiert. Auf diese Weise kann Scalas Typprüfung genutzt werden, um Transformationen und deren Komposition statisch zu verifizieren. / Domain-specific languages (DSLs) are software languages which are tailored to a specific application domain. DSLs enable domain experts to create domain-specific models, that is, high-level descriptions of domain knowledge. As any other software languages, DSLs rely on language tools which provide assistance for processing and managing domain-specific models. A domain-specific workbench is an integrated set of such tools for a DSL. A recently proposed approach is to automatically generate a domain-specific workbench for a DSL from a description of that DSL. However, existing tools which apply this approach do not support to describe and generate editable domain-specific views. A view is a part of domain-specific workbench that presents only one aspect of a model, for example, its hierarchical structure. This dissertation presents special model transformation languages which support the description of view synchronization in a generated domain-specific workbench. This allows a multi-view domain-specific workbench to be created with existing tools for language tool generation. We present a generated domain-specific workbench for the nanophysics domain and present a taxonomy of synchronization types. This allows us to precisely define what model transformations are required for view synchronization in that workbench. According to these requirements, we develop two transformation languages by adapting existing ones. In particular, we develop a bidirectional transformation language. With such a language one can describe a relation which defines whether two models are in sync and let the synchronization logic be inferred automatically. We implement model transformation languages as internal DSLs - that is, embedded as expressive libraries - in the Scala programming language and use Scala''s type checking for static verification of transformations and their composition.