View-based textual modelling

This work introduces the FURCAS approach, a framework for view-based textual modelling. FURCAS includes means that allow software language engineers to define partial and overlapping textual modelling languages. Furthermore, FURCAS provides an incremental update approach that enables modellers to work with multiple views on the same underlying model. The approach is validated against a set of formal requirements, as well as several industrial case studies showing its practical applicability

Configurable Software Performance Completions through Higher-Order Model Transformations

Chillies is a novel approach for variable model transformations closing the gap between abstract architecture models, used for performance prediction, and required low-level details. We enable variability of transformations using chain of generators based on the Higher-Order Transformation (HOT). HOTs target different goals, such as template instantiation or transformation composition. In addition, we discuss state-dependent behavior in prediction models and quality of model transformations

How To Touch a Running System

The increasing importance of distributed and decentralized software architectures entails more and more attention for adaptive software. Obtaining adaptiveness, however, is a difficult task as the software design needs to foresee and cope with a variety of situations. Using reconfiguration of components facilitates this task, as the adaptivity is conducted on an architecture level instead of directly in the code. This results in a separation of concerns; the appropriate reconfiguration can be devised on a coarse level, while the implementation of the components can remain largely unaware of reconfiguration scenarios. We study reconfiguration in component frameworks based on formal theory. We first discuss programming with components, exemplified with the development of the cmc model checker. This highly efficient model checker is made of C++ components and serves as an example for component-based software development practice in general, and also provides insights into the principles of adaptivity. However, the component model focuses on high performance and is not geared towards using the structuring principle of components for controlled reconfiguration. We thus complement this highly optimized model by a message passing-based component model which takes reconfigurability to be its central principle. Supporting reconfiguration in a framework is about alleviating the programmer from caring about the peculiarities as much as possible. We utilize the formal description of the component model to provide an algorithm for reconfiguration that retains as much flexibility as possible, while avoiding most problems that arise due to concurrency. This algorithm is embedded in a general four-stage adaptivity model inspired by physical control loops. The reconfiguration is devised to work with stateful components, retaining their data and unprocessed messages. Reconfiguration plans, which are provided with a formal semantics, form the input of the reconfiguration algorithm. We show that the algorithm achieves perceived atomicity of the reconfiguration process for an important class of plans, i.e., the whole process of reconfiguration is perceived as one atomic step, while minimizing the use of blocking of components. We illustrate the applicability of our approach to reconfiguration by providing several examples like fault-tolerance and automated resource control

Configurable Software Performance Completions through Higher-Order Model Transformations

Chillies is a novel approach for variable model transformations closing the gap between abstract architecture models, used for performance prediction, and required low-level details. We enable variability of transformations using chain of generators based on the Higher-Order Transformation (HOT). HOTs target different goals, such as template instantiation or transformation composition. In addition, we discuss state-dependent behavior in prediction models and quality of model transformations

Comprehensive measurement framework for enterprise architectures

Enterprise Architecture defines the overall form and function of systems across an enterprise involving the stakeholders and providing a framework, standards and guidelines for project-specific architectures. Project-specific Architecture defines the form and function of the systems in a project or program, within the context of the enterprise as a whole with broad scope and business alignments. Application-specific Architecture defines the form and function of the applications that will be developed to realize functionality of the system with narrow scope and technical alignments. Because of the magnitude and complexity of any enterprise integration project, a major engineering and operations planning effort must be accomplished prior to any actual integration work. As the needs and the requirements vary depending on their volume, the entire enterprise problem can be broken into chunks of manageable pieces. These pieces can be implemented and tested individually with high integration effort. Therefore it becomes essential to analyze the economic and technical feasibility of realizable enterprise solution. It is difficult to migrate from one technological and business aspect to other as the enterprise evolves. The existing process models in system engineering emphasize on life-cycle management and low-level activity coordination with milestone verification. Many organizations are developing enterprise architecture to provide a clear vision of how systems will support and enable their business. The paper proposes an approach for selection of suitable enterprise architecture depending on the measurement framework. The framework consists of unique combination of higher order goals, non-functional requirement support and inputs-outcomes pair evaluation. The earlier efforts in this regard were concerned about only custom scales indicating the availability of a parameter in a range.Comment: 22 Page

Model consistency management for systems engineering

Um der Komplexität der interdisziplinären Entwicklung moderner technischer Systeme Herr zu werden, findet die Entwicklung heutzutage meist modellbasiert statt. Dabei werden zahlreiche verschiedene Modelle genutzt, die jeweils unterschiedliche Gesichtspunkte berücksichtigen und sich auf verschiedenen Abstraktionsebenen befinden. Wenn die hierbei auftretenden Inkonsistenzen zwischen den Modellen ungelöst bleiben, kann dies zu Fehlern im fertigen System führen. Modelltransformations- und -synchronisationstechniken sind ein vielversprechender Ansatz, um solche Inkonsistenzen zu erkennen und aufzulösen. Existierende Modellsynchronisationstechniken sind allerdings nicht mächtig genug, um die komplexen Beziehungen in so einem Entwicklungsszenario zu unterstützen. In dieser Arbeit wird eine neue Modellsynchronisationstechnik präsentiert, die es erlaubt, Modelle verschiedener Sichten und Abstraktionsebenen zu synchronisieren. Dabei werden Metriken zur Erhöhung des Automatisierungsgrads eingesetzt, die Expertenwissen abbilden. Der Ansatz erlaubt unterschiedliche Grade an Benutzerinteraktion, von vollautomatischer Funktionsweise bis zu feingranularen manuellen Entscheidungen.The development of complex mechatronic systems requires the close collaboration of different disciplines, like mechanical engineering, electrical engineering, control engineering, and software engineering. To tackle the complexity of such systems, such a development is heavily based on models. Engineers use several models on different abstraction levels, for different purposes and with different view-points. Usually, a discipline-spanning system model is developed during the first, interdisciplinary system design phase. For the implementation phase, the disciplines use different models and tools to develop the discipline-specific aspects of the system. During such a model-based development, inconsistencies between the different discipline-specific models and the discipline-spanning system model are likely to occur, because changes to discipline-specific models may affect the discipline-spanning system model and models of other disciplines. These inconsistencies lead to increased development time and costs if they remain unresolved. Model transformation and synchronization are promising techniques to detect and resolve such inconsistencies. However, existing model synchronization solutions are not powerful enough to support the complex consistency relations of such an application scenario. In this thesis, we present a novel model synchronization technique that allows for synchronized models with multiple views and abstraction levels. To minimize the information loss and improve automation during the synchronization, it employs metrics to encode expert knowledge. The approach can be customized to allow different amounts of user interaction, from full automation to fine-grained manual decisions.Tag der Verteidigung: 24.10.2014Paderborn, Univ., Diss., 201

Reactive Model Transformation with ATL

International audienceModel-driven applications may maintain large networks of structured data models and transformations among them. The development of such applications is complicated by the need to reflect on the whole network any runtime update performed on models or transformation logic. If not carefully designed, the execution of such updates may be computationally expensive. In this paper we propose a reactive paradigm for programming model transformations, and we implement a reactive model-transformation engine. We argue that this paradigm facilitates the development of autonomous model-driven systems that react to update and request events from the host application by identifying and performing only the needed computation. We implement such approach by providing a reactive engine for the ATL transformation language. We evaluate the usage scenarios that this paradigm supports and we experimentally measure its ability to reduce computation time in transformation-based applications

The diffusion, modularization, and institutionalisation of Direct Social Actions in healthcare. The Greek Healthcare Arena: 1983-2019

This thesis is the product of my political and scholarly engagement with healthcare activism in Greece during the past decade and, more specifically, with the Social Clinics-Pharmacies’ movement that emerged in the country over the course of the most recent cycle of anti-austerity contention. The Social Clinics-Pharmacies’ movement was composed of grassroots clinics and/or pharmacies that provided free healthcare services and pharmaceuticals and engaged in protest tactics for reform in the Greek National Healthcare System. In just two years the movement became prominent and affected opportunities for itself. As such, and upon the closure of the cycle of contention and the rise of its ally-party SYRIZA into power in 2015, representatives of the movement were invited to participate in the drafting of healthcare reform around two of the most pressing and unresolved issues of the Greek National Healthcare System since its establishment in 1983. These pertained to the extension of coverage and the development of a comprehensive Primary Care level. I argue that this involvement of the movement into policymaking is an instance of movement institutionalization that reinforced convergence around tactics of healthcare provision from below as well as divergence in their strategic employment. By 2016 the movement had dissolved while individual clinics and/or pharmacies continued their operations. Departing from this case study, this thesis contributes to the existing social movement scholarship in at least three directions. First, it enriches analyses on repertoire innovation by providing a contextual and strategic perspective to the appropriation of tactics of healthcare provision by different actors. The expansion of Direct Social Action tactics (henceforth DSAs) has received attention over the past years and has been interpreted as reflecting a double deficit in democratic and welfare politics. I argue that healthcare DSAs compel us to study the configuration of strategies against fluctuating socio-economic and political environments and within particular institutional arrangements that advance as central for the domain of healthcare. In addition, this thesis advances the recent literature on DSAs by introducing a relational, dynamic and longitudinal perspective to their employment. This is achieved through the close investigation of healthcare DSA tactics from (i) the first instances of their utilisation after the establishment of the Greek National Healthcare System, (ii) their diffusion and modularization in the years following the 2010 crisis and the cycle of anti-austerity contention, as well as (iii) their solidification following movement institutionalization. Those three periods highlight the contextual and dynamic, interactive and strategic dimensions of the employment of healthcare DSAs. Last, this thesis embellishes accounts on movement institutionalization. More specifically the longitudinal investigation of the Social Clinics-Pharmacies allows us to approach institutionalization as at once a process and an outcome of the diffusion of healthcare DSAs in the Greek healthcare arena. As I hope to show the healthcare arena molded the profile of the movement as particularly institutionally oriented, and prone in assisting in and negotiating over progressive healthcare reform. This led to the swift institutionalisation of the movement at the peak of the Social Clinics-Pharmacies’ paradigm. Institutionalization, therefore, was a process composed of the various interactions between all those actors animating the Greek healthcare arena in the direction of repertoire innovation and healthcare reform. Institutionalization was also an outcome of collective action, with direct implications onto healthcare policy and indirect, unintended effects for the movement. Following movement institutionalisation, movement dissolution and the advent of reform, I observe the carving of different trajectories to and fro the same tactics of healthcare provision configured around the different interpretations of the reform and, relatedly, distinct strategic uses of healthcare DSAs

On the scope and assessment of pesticides in groundwater in Skåne, Sweden

Pesticides are known to occur in groundwater worldwide. However, long-term pollution concerns and cause-effect relationships for specific regions remain limited. This thesis explores the occurrence of pesticides in south-Swedish groundwater, with the aims of providing a better knowledge basis for assessment and management of present-day and future pollution risks. The investigations are restricted to Skåne, which is a relatively populous, intensively cultivated and geologically diverse region located at the tip of the Scandinavian Peninsula. The research shows that pesticides are present in very different types of groundwater systems around Skåne, suggesting a wide-ranging, multi-faceted and potentially long-lasting pollution concern. Seemingly, it is only the groundwater environments devoid of influence of waters having recharged since the onset of widespread pesticide use that may be regarded as completely safe and unaffected. Many of the pesticides detected stem from past, less restricted use, primarily for weed control outside of agriculture. Yet, current and future pollution concerns should not be regarded only as a matter of “old sins” as residues from currently used substances manifestly continue to leach towards and into the groundwater system. Through various analyses of comprehensive data sets both at the regional and the catchment scale, a number of particularly important aspects of regional pesticide occurrence in groundwater and future prediction thereof are inferred and investigated. In addition to application intensities and fundamental physicochemical pesticide properties, these include precipitation and recharge patterns in relation to pesticide application events, (mainly superficial) sorption and degradation processes efficiencies, multiple-scale subsurface physical heterogeneity directing water and solute flow (particularly the presence of preferential flow pathways), and groundwater turnover rates. Environmental tracers show great potential as tools for simple but effective calibration of transport models and for deciphering pollution trends and patterns. However, there are certain tracer-specific complications in need of further attention for future application in Skåne. For the future, regional as well as nationwide monitoring of pesticides in groundwater needs to be expanded and regulated for sound groundwater and pollution risk management and in order to be able to comply with environmental directives and the EU Water Framework Directive