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See detailTowards systemic change: On the co-creation and evaluation of a study programme in transformative sustainability science with stakeholders in Luxembourg
König, Ariane UL

in Current Opinion in Environmental Sustainability (2015), 16

This paper examines a study programme in ‘Sustainability and social innovation’ at the University of Luxembourg that was co-created with key external stakeholders in local sustainability transitions.The ... [more ▼]

This paper examines a study programme in ‘Sustainability and social innovation’ at the University of Luxembourg that was co-created with key external stakeholders in local sustainability transitions.The programme’s aim is to equip scientists and citizens for the practice of transformative sustainability science to change human environment interactions. Addressing socially salient, complex problems invites a re-conception of what role universities can play in knowledge production processes in more applied and local contexts. We critically discuss the programme’s ambition to provide a platform for transformative social learning for sustainability and to contribute to fostering systemic change in Luxembourg. We deduce design requisites to achieve these ambitions. The paper also discusses the role of different forms of evaluation in effecting individual programme and systemic change. Research insights were drawn from documentary and literature research, concept-building, programme implementation, observation, analysis, and evaluation by students and contributors. [less ▲]

Detailed reference viewed: 132 (11 UL)
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See detailTowards Temporal Conviviality Measures
Caire, Patrice UL; Alcalde, Baptiste UL; van der Torre, Leon UL et al

in Benelux Conference on Artificial Intelligence (2011)

Detailed reference viewed: 39 (1 UL)
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See detailTowards Test-Driven and Architecture Model-Based Security and Resilience Engineering
Saidane, Ayda; Guelfi, Nicolas UL

in Singh, Hardeep; Kaur, Kulwant (Eds.) Designing, Engineering, and Analyzing Reliable and Efficient Software (2013)

Detailed reference viewed: 44 (0 UL)
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See detailTowards the Arms Trade Treaty
Mochtak, Michal UL

in Majer, Marián; Ondrejcsál, Róbert; Tarasovič, Vladimír (Eds.) et al Panorama of global security environment 2014 (2015)

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See detailTowards the Existential Control of Boolean Networks: A Preliminary Report
Paul, Soumya UL; Pang, Jun UL; Su, Cui

in Proceedings of the 4th International Symposium on Dependable Software Engineering. Theories, Tools, and Applications (2018)

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See detailTowards the Formal Verification of Model Transformations: An Application to Kermeta
Amrani, Moussa UL

Doctoral thesis (2013)

Model-Driven Engineering (MDE) is becoming a popular engineering methodology for developing large-scale software applications, using models and transformations as primary principles. MDE is now being ... [more ▼]

Model-Driven Engineering (MDE) is becoming a popular engineering methodology for developing large-scale software applications, using models and transformations as primary principles. MDE is now being successfully applied to domain-specific languages (DSLs), which target a narrow subject domain like process management, telecommunication, product lines, smartphone applications among others, providing experts high-level and intuitive notations very close to their problem domain. More recently, MDE has been applied to safety-critical applications, where failure may have dramatic consequences, either in terms of economic, ecologic or human losses. These recent application domains call for more robust and more practical approaches for ensuring the correctness of models and model transformations. Testing is the most common technique used in MDE for ensuring the correctness of model transformations, a recurrent, yet unsolved problem in MDE. But testing suffers from the so-called coverage problem, which is unacceptable when safety is at stake. Rather, exhaustive coverage is required in this application domain, which means that transformation designers need to use formal analysis methods and tools to meet this requirement. Unfortunately, two factors seem to limit the use of such methods in an engineer’s daily life. First, a methodological factor, because MDE engineers rarely possess the effective knowledge for deploying formal analysis techniques in their daily life developments. Second, a practical factor, because DSLs do not necessarily have a formal explicit semantics, which is a necessary enabler for exhaustive analysis. In this thesis, we contribute to the problem of formal analysis of model transformations regarding each perspective. On the conceptual side, we propose a methodological framework for engineering verified model transformations based on current best practices. For that purpose, we identify three important dimensions: (i) the transformation being built; (ii) the properties of interest ensuring the transformation’s correctness; and finally, (iii) the verification technique that allows proving these properties with minimal effort. Finding which techniques are better suited for which kind of properties is the concern of the Computer-Aided Verification community. Consequently in this thesis, we focus on studying the relationship between transformations and properties. Our methodological framework introduces two novel notions. A transformation intent gathers all transformations sharing the same purpose, abstracting from the way the transformation is expressed. A property class captures under the same denomination all properties sharing the same form, abstracting away from their underlying property languages. The framework consists of mapping each intent with its characteristic set of property classes, meaning that for proving the correctness of a particular transformation obeying this intent, one has to prove properties of these specific classes. We illustrate the use and utility of our framework through the detailed description of five common intents in MDE, and their application to a case study drawn from the automative software domain, consisting of a chain of more than thirty transformations. On a more practical side, we study the problem of verifying DSLs whose behaviour is expressed with Kermeta. Kermeta is an object-oriented transformation framework aligned with Object Management Group standard specification MOF (Meta-Object Facility). It can be used for defining metamodels and models, as well as their behaviour. Kermeta lacks a formal semantics: we first specify such a semantics, and then choose an appropriate verification domain for handling the analysis one is interested in. Since the semantics is defined at the level of Kermeta’s transformation language itself, our work presents two interesting features: first, any DSL whose behaviour is defined using Kermeta (more precisely, any transformation defined with Kermeta) enjoys a de facto formal underground for free; second, it is easier to define appropriate abstractions for targeting specific analysis for this full-fledged semantics than defining specific semantics for each possible kind of analysis. To illustrate this point, we have selected Maude, a powerful rewriting system based on algebraic specifications equipped with model-checking and theorem-proving capabilities. Maude was chosen because its underlying formalism is close to the mathematical tools we use for specifying the formal semantics, reducing the implementation gap and consequently limiting the possible implementation mistakes. We validate our approach by illustrating behavioural properties of small, yet representative DSLs from the literature. [less ▲]

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See detailTowards the formalization of properties of cloud-based elastic systems
Bersani, Marcello Maria; Bianculli, Domenico UL; Dustdar, Schahram et al

in Proceedings of the 6th International Workshop on Principles of Engineering Service-oriented Systems (PESOS 2014) (2014)

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See detailTowards the Identification of Condition-Specific Microbial Populations from Human Metagenomic Data
Laczny, Cédric UL; Wilmes, Paul UL

in Keller, Andreas; Meese, Eckart (Eds.) Nucleic Acids as Molecular Diagnostics (2014)

Detailed reference viewed: 64 (6 UL)
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See detailTowards the knowledge democracy? Knowledge production and the civic role of the university.
Biesta, Gert UL

in Studies in Philosophy & Education (2007), 26(5), 467-479

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See detailTowards the Orchestration of Secured Services under Non-disclosure Policies
Avanesov, Tigran UL; Chevalier, Yannick; Rusinowitch, Michaël et al

in 6th International Conference on Mathematical Methods, Models and Architectures for Computer Network Security, MMM-ACNS 2012, St. Petersburg, Russia, October 17-19, 2012. Proceedings (2012)

The problem of finding a mediator to compose secured services has been reduced in our former work to the problem of solving deducibility constraints similar to those employed for cryptographic protocol ... [more ▼]

The problem of finding a mediator to compose secured services has been reduced in our former work to the problem of solving deducibility constraints similar to those employed for cryptographic protocol analysis. We extend in this paper the mediator synthesis procedure by a construction for expressing that some data is not accessible to the mediator. Then we give a decision procedure for verifying that a mediator satisfying this non-disclosure policy can be effectively synthesized. This procedure has been implemented in CL-AtSe, our protocol analysis tool. The procedure extends constraint solving for cryptographic protocol analysis in a significative way as it is able to handle negative deducibility constraints without restriction. In particular it applies to all subterm convergent theories and therefore covers several interesting theories in formal security analysis including encryption, hashing, signature and pairing. [less ▲]

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See detailTowards the Propagation of Model Updates along different Views in Multi-View Models
Gottmann, Susann UL; Nachtigall, Nico UL; Ermel, Claudia et al

in Proceedings of the 5th International Workshop on Bidirectional Transformations (2016), 1571

Models are the keystones in model-driven systems development. They describe systems at different layers of abstraction and with a focus to different domains. For each domain, dedicated domain specific ... [more ▼]

Models are the keystones in model-driven systems development. They describe systems at different layers of abstraction and with a focus to different domains. For each domain, dedicated domain specific visual modelling languages are used for model definitions with the idea to separate concerns to different domain experts. This enables precise problem and requirement definitions and should decrease efforts in developing and validating systems. We focus on multi-view models that are in relationship with source models by triple graph grammars. A multi-view model provides different views of the source model at different layers of abstraction but within the same DSL which is typically different from the DSL of the source model. In practice, elements in different views may overlap. We present an informal methodology for consistently propagating updates from one view to the other views and also to the source domain. We motivate our approach by multi-view models in a hospital scenario. [less ▲]

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See detailTowards the Systematic Analysis of Non-Functional Properties in Model-Based Engineering for Real-Time Embedded Systems
Brau, Guillaume UL; Navet, Nicolas UL; Hugues, Jérôme

in Science of Computer Programming (2018), 156

The real-time scheduling theory provides analytical methods to assess the temporal predictability of embedded systems. Nevertheless, their use is limited in a Model-Based Systems Engineering approach. In ... [more ▼]

The real-time scheduling theory provides analytical methods to assess the temporal predictability of embedded systems. Nevertheless, their use is limited in a Model-Based Systems Engineering approach. In fact, the large number of applicability conditions makes the use of real-time scheduling analysis tedious and error-prone. Key issues are left to the engineers: when to apply a real-time scheduling analysis? What to do with the analysis results?} This article presents an approach to systematize and then automate the analysis of non-functional properties in Model-Based Systems Engineering. First, preconditions and postconditions define the applicability of an analysis. In addition, contracts specify the analysis interfaces, thereby enabling to reason about the analysis process. We present a proof-of-concept implementation of our approach using a combination of constraint languages (REAL for run-time analysis) and specification languages (Alloy for describing interfaces and reasoning about them). This approach is experimented on architectural models written with the Architecture Analysis and Design Language (AADL). [less ▲]

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See detailTowards the time-variable gravity field from CHAMP
Weigelt, Matthias UL; Jäggi, A.; Prange, L. et al

Scientific Conference (2011, July)

Detailed reference viewed: 13 (0 UL)
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See detailTowards Translating Graph Transformation Systems by Model Transformation
Kastenberg, Harmen; Hermann, Frank UL; Modica, Tony

in Proc. Int. Workshop on Graph and Model Transformation (GraMoT'06) (2006)

Recently, many researchers are working on semantics preserving model transformation. In the field of graph transformation one can think of translating graph grammars written in one approach to a ... [more ▼]

Recently, many researchers are working on semantics preserving model transformation. In the field of graph transformation one can think of translating graph grammars written in one approach to a behaviourally equivalent graph grammar in another approach. In this paper we translate graph grammars developed with the GROOVE tool to AGG graph grammars by first investigating the set of core graph transformation concepts supported by both tools. Then, we define what it means for two graph grammars to be behaviourally equivalent, and for the regar/ded approaches we actually show how to handle different definitions of both - application conditions and graph structures. The translation itself is explained by means of intuitive examples. [less ▲]

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See detailTowards tunable defect arrangements in smectic liquid crystal shells utilizing the nematic-smectic transition in hybrid-aligned geometries
Liang, Hsin-Ling; Zentel, Rudolf; Rudquist, Per et al

in Soft Matter (2012), 8(20), 5443-5450

We produce and investigate liquid crystal shells with hybrid alignment—planar at one boundary, homeotropic at the other—undergoing a transition between the nematic (N) and smectic-A (SmA) phases. The ... [more ▼]

We produce and investigate liquid crystal shells with hybrid alignment—planar at one boundary, homeotropic at the other—undergoing a transition between the nematic (N) and smectic-A (SmA) phases. The shells display a dynamic sequence of patterns, the details depending on the alignment agents and on the diameter and thickness of the shell. In shells of sufficient diameter we typically find a transient striped texture near the N–SmA transition, stabilising into a pattern of tiled, more or less regularly spaced focal conic domains in the SmA phase. The domain size and spacing decrease with reduced shell thickness. In case of strong homeotropic anchoring at one boundary and small shell size, however, the increased curvature favors homeotropic against planar alignment in the smectic phase, and the shell then tends to adapt to complete homeotropic alignment at the final stage of the transition. This is the first study of hybrid-aligned smectic shells and the results constitute a beautiful demonstration of the capacity for dynamic structure formation and reformation via self-assembly in soft matter. The new patterns extend the range of arrays of topological defects that can be realised with liquid crystals in spherical morphology and the correlation between the feature arrangements and the variable parameters of the shell and its environment opens a route towards tunability. However, the observed strong impact from increasing curvature, even for these rather large shells, indicates that the choice of alignment agents inducing planar or homeotropic alignment with varying strength will become critical when targeting the most attractive colloidal size scale of about a micron or smaller. [less ▲]

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See detailTowards understanding of magnetization reversal in Nd-Fe-B nanocomposites: analysis by high-throughput micromagnetic simulations
Erokhin, S.; Berkov, D.; Ito, M. et al

in Journal of Physics : Condensed Matter (2018), 30

We demonstrate how micromagnetic simulations can be employed in order to characterize and analyze the magnetic microstructure of nanocomposites. For the example of nanocrystalline Nd-Fe-B, which is a ... [more ▼]

We demonstrate how micromagnetic simulations can be employed in order to characterize and analyze the magnetic microstructure of nanocomposites. For the example of nanocrystalline Nd-Fe-B, which is a potential material for future permanent-magnet applications, we have compared three different models for the micromagnetic analysis of this material class: (i) a description of the nanocomposite microstructure in terms of Stoner-Wohlfarth particles with and without the magnetodipolar interaction; (ii) a model based on the core-shell representation of the nanograins; (iii) the latter model including a contribution of superparamagnetic clusters. The relevant parameter spaces have been systematically scanned with the aim to establish which micromagnetic approach can most adequately describe experimental data for this material. According to our results, only the last, most sophisticated model is able to provide an excellent agreement with the measured hysteresis loop. The presented methodology is generally applicable to multiphase magnetic nanocomposites and it highligths the complex interrelationship between the microstructure, magnetic interactions, and the macroscopic magnetic properties. [less ▲]

Detailed reference viewed: 36 (4 UL)
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See detailTowards Visual Analytics of Multilayer Graphs for Digital Cultural Heritage
McGee, Fintan; During, Marten UL; Ghoniem, Mohammad

in Towards Visual Analytics of Multilayer Graphs for Digital Cultural Heritage (2016)

Detailed reference viewed: 61 (5 UL)
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See detailTowards whole cell "in silico" models for cellular systems: model set-up and model validation
Kremling, A.; Bettenbrock, K.; Fischer, S. et al

in Lecture Notes in Control and Information Sciences: Proceedings of the first multidisciplinary international symposium on Positive Systems (2004)

Detailed reference viewed: 23 (0 UL)
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See detailA towel less: Social norms enhance pro-environmental behavior in hotels
Reese, Gerhard UL; Loew, Kristina; Steffgen, Georges UL

in Journal of Social Psychology (2014), (154), 97-100

Previous research has shown that normative appeals to engage in environmentally friendly behavior were most effective when they were accompanied by a provincial norm (e.g., when norms matched individuals’ ... [more ▼]

Previous research has shown that normative appeals to engage in environmentally friendly behavior were most effective when they were accompanied by a provincial norm (e.g., when norms matched individuals’ immediate situational circumstances). Analyzing hotel guests’ towel-use during their stay, the current study tests whether messages employing provincial norms were more effective in reducing towel-use than standard environmental messages. In line with previous findings, guests of two hotels used significantly fewer towels when provincial normative appeals—rather than standard environmental messages—were communicated. These findings corroborate to the body of research demonstrating the power of social norms on environmental behavior. [less ▲]

Detailed reference viewed: 154 (18 UL)