Model-Based Run-time Verification of Software Components by Integrating OCL into Treaty

Model Driven Development is used to improve software quality and efficiency by automatically transforming abstract and formal models into software implementations. This is particularly sensible if the model’s integrity can be proven formally and is preserved during the model’s transformation. A standard to specify software model integrity is the Object Constraint Language (OCL). Another topic of research is the dynamic development of software components, enabling software system composition at component run-time. As a consequence, the system’s verification must be realized during system run-time (and not during transformation or compile time). Many established verification techniques cannot be used for run-time verification. A method to enable model-based run-time verification will be developed during this work. How OCL constraints can be transformed into executable software artifacts and how they can be used in the component-based system Treaty will be the major task of this diploma thesis.Modellgetriebene Entwicklung dient der Verbesserung von Qualität und Effizienz in der Software-Entwicklung durch Automatisierung der notwendigen Transformationen von abstrakten bzw. formalen Modellen bis zur Implementierung. Dies ist insbesondere dann sinnvoll, wenn die Integrität der ursprünglichen Modelle formal bewiesen werden kann und durch die Transformation gewährleistet wird. Ein Standard zur Spezifikation der Integrität von Softwaremodellen ist die Object Constraint Language (OCL). Eine weitere Forschungsrichtung im Software-Engineering ist die Entwicklung von dynamischen Komponenten-Modellen, die die Komposition von Softwaresystemen im laufenden Betrieb ermöglichen. Dies bedeutet, dass die Systemverifikation im laufenden Betrieb realisiert werden muss. Die meisten der etablierten Verifikationstechniken sind dazu nicht geeignet. In der Diplomarbeit soll ausgehend von diesem Stand der Technik eine Methode zur modellbasierten Verifikation zur Laufzeit entwickelt werden. Insbesondere soll untersucht werden, wie OCL-Constraints zur Laufzeit in ausführbare Software-Artefakte übersetzt und in dem komponentenbasierten System Treaty verwendet werden können

Überblick zur Softwareentwicklung in Wissenschaftlichen Anwendungen

Viele wissenschaftliche Disziplinen müssen heute immer komplexer werdende numerische Probleme lösen. Die Komplexität der benutzten wissenschaftlichen Software steigt dabei kontinuierlich an. Diese Komplexitätssteigerung wird durch eine ganze Reihe sich ändernder Anforderungen verursacht: Die Betrachtung gekoppelter Phänomene gewinnt Aufmerksamkeit und gleichzeitig müssen neue Technologien wie das Grid-Computing oder neue Multiprozessorarchitekturen genutzt werden, um weiterhin in angemessener Zeit zu Berechnungsergebnissen zu kommen. Diese Fülle an neuen Anforderungen kann nicht mehr von kleinen spezialisierten Wissenschaftlergruppen in Isolation bewältigt werden. Die Entwicklung wissenschaftlicher Software muss vielmehr in interdisziplinären Gruppen geschehen, was neue Herausforderungen in der Softwareentwicklung induziert. Ein Paradigmenwechsel zu einer stärkeren Separation von Verantwortlichkeiten innerhalb interdisziplinärer Entwicklergruppen ist bis jetzt in vielen Fällen nur in Ansätzen erkennbar. Die Kopplung partitioniert durchgeführter Simulationen physikalischer Phänomene ist ein wichtiges Beispiel für softwaretechnisch herausfordernde Aufgaben im Gebiet des wissenschaftlichen Rechnens. In diesem Kontext modellieren verschiedene Simulationsprogramme unterschiedliche Teile eines komplexeren gekoppelten Systems. Die vorliegende Arbeit gibt einen Überblick über Paradigmen, die darauf abzielen Softwareentwicklung für Berechnungsprogramme verlässlicher und weniger abhängig voneinander zu machen. Ein spezielles Augenmerk liegt auf der Entwicklung gekoppelter Simulationen.Fields of modern science and engineering are in need of solving more and more complex numerical problems. The complexity of scientific software thereby rises continuously. This growth is caused by a number of changing requirements. Coupled phenomena gain importance and new technologies like the computational Grid, graphical and heterogeneous multi-core processors have to be used to achieve high-performance. The amount of additional complexity can not be handled by small groups of specialised scientists. The interdiciplinary nature of scientific software thereby presents new challanges for software engineering. A paradigm shift towards a stronger separation of concerns becomes necessary in the development of future scientific software. The coupling of independently simulated physical phenomena is an important example for a software-engineering concern in the domain of computational science. In this context, different simulation-programs model only a part of a more complex coupled system. The present work gives overview on paradigms which aim at making software-development in computational sciences more reliable and less interdependent. A special focus is put on the development of coupled simulations

A high performance data parallel tensor contraction framework: Application to coupled electro-mechanics

The paper presents aspects of implementation of a new high performance tensor contraction framework for the numerical analysis of coupled and multi-physics problems on streaming architectures. In addition to explicit SIMD instructions and smart expression templates, the framework introduces domain specific constructs for the tensor cross product and its associated algebra recently rediscovered by Bonet et al. (2015, 2016) in the context of solid mechanics. The two key ingredients of the presented expression template engine are as follows. First, the capability to mathematically transform complex chains of operations to simpler equivalent expressions, while potentially avoiding routes with higher levels of computational complexity and, second, to perform a compile time depth-first search to find the optimal contraction indices of a large tensor network in order to minimise the number of floating point operations. For optimisations of tensor contraction such as loop transformation, loop fusion and data locality optimisations, the framework relies heavily on compile time technologies rather than source-to-source translation or JIT techniques. Every aspect of the framework is examined through relevant performance benchmarks, including the impact of data parallelism on the performance of isomorphic and nonisomorphic tensor products, the FLOP and memory I/O optimality in the evaluation of tensor networks, the compilation cost and memory footprint of the framework and the performance of tensor cross product kernels. The framework is then applied to finite element analysis of coupled electromechanical problems to assess the speed-ups achieved in kernel-based numerical integration of complex electroelastic energy functionals. In this context, domain-aware expression templates are shown to provide a significant speed-up over the classical low-level style programming techniques

Extracting proofs from documents

Often, theorem checkers like PVS are used to check an existing proof, which is part of some document. Since there is a large difference between the notations used in the documents and the notations used in the theorem checkers, it is usually a laborious task to convert an existing proof into a format which can be checked by a machine. In the system that we propose, the author is assisted in the process of converting an existing proof into the PVS language and having it checked by PVS. 1 Introduction The now-classic ALGOL 60 report [5] recognized three different levels of language: a reference language, a publication language and several hardware representations, whereby the publication language was intended to admit variations on the reference language and was to be used for stating and communicating processes. The importance of publication language ---often referred to nowadays as "pseudo-code"--- is difficult to exaggerate since a publication language is the most effective way..