References of "Internal report"
     in
Bookmark and Share    
Full Text
See detailTowards a Plug-and-Play and Holistic Data Mining Framework for Understanding and Facilitating Operations in Smart Buildings
Li, Daoyuan UL; Bissyande, Tegawendé François D Assise UL; Klein, Jacques UL et al

Report (2017)

Nowadays, a significant portion of the total energy consumption is attributed to the buildings sector. In order to save energy and protect the environment, energy consumption in buildings must be more ... [more ▼]

Nowadays, a significant portion of the total energy consumption is attributed to the buildings sector. In order to save energy and protect the environment, energy consumption in buildings must be more efficient. At the same time, buildings should offer the same (if not more) comfort to their occupants. Consequently, modern buildings have been equipped with various sensors and actuators and interconnected control systems to meet occupants’ requirements. Unfortunately, so far, Building Automation Systems data have not been well-exploited due to technical and cost limitations. Yet, it can be exceptionally beneficial to take full advantage of the data flowing inside buildings in order to diagnose issues, explore solutions and improve occupant-building interactions. This paper presents a plug-and-play and holistic data mining framework named PHoliData for smart buildings to collect, store, visualize and mine useful information and domain knowledge from data in smart buildings. PHoliData allows non technical experts to easily explore and understand their buildings with minimum IT support. An architecture of this framework has been introduced and a prototype has been implemented and tested against real-world settings. Discussions with industry experts have suggested the system to be extremely helpful for understanding buildings, since it can provide hints about energy efficiency improvements. Finally, extensive experiments have demonstrated the feasibility of such a framework in practice and its advantage and potential for buildings operators. [less ▲]

Detailed reference viewed: 11 (1 UL)
Full Text
See detailAn Integrated Approach for Effective Injection Vulnerability Analysis of Web Applications through Security Slicing and Hybrid Constraint Solving
Thome, Julian UL; Shar, Lwin Khin UL; Bianculli, Domenico UL et al

Report (2017)

Malicious users can attack Web applications by exploiting injection vulnerabilities in the source code. This work addresses the challenge of detecting injection vulnerabilities in a scalable and effective ... [more ▼]

Malicious users can attack Web applications by exploiting injection vulnerabilities in the source code. This work addresses the challenge of detecting injection vulnerabilities in a scalable and effective way. We propose an integrated approach that seamlessly combines security slicing with hybrid constraint solving, i.e., constraint solving based on a combination of automata-based solving and meta-heuristic search. We use static analysis to extract minimal program slices relevant to security from Web programs and to generate attack conditions. We then apply hybrid constraint solving to determine the satisfiability of attack conditions and thus detect vulnerabilities. The experimental results, using a benchmark suite comprising nine diverse and representative Web applications, show that our approach (implemented in the JOACO tool) is significantly more effective at detecting injection vulnerabilities than state-of-the-art approaches, achieving 98% recall, without producing any false alarm. We also compared the constraint solving module of our approach with state-of-the-art constraint solvers, using five different benchmark suites; our approach correctly solved the highest number of constraints (43177 out of 43184), without producing any incorrect result, and was the one with the least number of time-out/failing cases. In both scenarios, the execution time was practically acceptable, given the offline nature of vulnerability detection. [less ▲]

Detailed reference viewed: 47 (2 UL)
Full Text
See detailModeling Security and Privacy Requirements for Mobile Applications: a Use Case-driven Approach
Mai, Xuan Phu UL; Göknil, Arda UL; Shar, Lwin Khin UL et al

Report (2017)

Defining and addressing security and privacy requirements in mobile apps is a significant challenge due to the high level of transparency regarding users' (private) information. In this paper, we propose ... [more ▼]

Defining and addressing security and privacy requirements in mobile apps is a significant challenge due to the high level of transparency regarding users' (private) information. In this paper, we propose, apply, and assess a modeling method that supports the specification of security and privacy requirements of mobile apps in a structured and analyzable form. Our motivation is that, in many contexts including mobile app development, use cases are common practice for the elicitation and analysis of functional requirements and should also be adapted for describing security requirements. We integrate and adapt an existing approach for modeling security and privacy requirements in terms of security threats, their mitigations, and their relations to use cases in a misuse case diagram. We introduce new security-related templates, i.e., a mitigation template and a misuse case template for specifying mitigation schemes and misuse case specifications in a structured and analyzable manner. Natural language processing can then be used to automatically detect and report inconsistencies among artifacts and between the templates and specifications. Since our approach supports stakeholders in precisely specifying and checking security threats, threat scenarios and their mitigations, it is expected to help with decision making and compliance with standards for improving security. We successfully applied our approach to industrial mobile apps and report lessons learned and results from structured interviews with engineers. [less ▲]

Detailed reference viewed: 108 (14 UL)
Full Text
See detailGuru: Universal Reputation Module for Distributed Consensus Protocols
Biryukov, Alex UL; Feher, Daniel UL; Khovratovich, Dmitry UL

Report (2017)

In this paper we describe how to couple reputation systems with distributed consensus protocols to provide high-throughput highly-scalable consensus for large peer-to-peer networks of untrusted validators ... [more ▼]

In this paper we describe how to couple reputation systems with distributed consensus protocols to provide high-throughput highly-scalable consensus for large peer-to-peer networks of untrusted validators. We introduce reputation module Guru, which can be laid on top of various consensus protocols such as PBFT or HoneyBadger. It ranks nodes based on the outcomes of consensus rounds run by a small committee, and adaptively selects the committee based on the current reputation. The protocol can also take external reputation ranking as input. Guru can tolerate larger threshold of malicious nodes (up to slightly above 1/2) compared to the 1/3 limit of BFT consensus algorithms. [less ▲]

Detailed reference viewed: 117 (9 UL)
Full Text
See detailANED Country report on Social Protection and Article 28: Luxembourg
Limbach-Reich, Arthur UL; ANED core team

Report (2017)

Detailed reference viewed: 75 (8 UL)
See detailMapping Educational Paths of Youth Workers and Gathering Knowledge on Youth Work – Country Sheet Luxembourg.
Heinen, Andreas UL

Report (2017)

This report is part of a research initiative entitled Mapping Educational Paths of Youth Workers and Gathering Knowledge on Youth Work. Its main objective is to contribute to a better understanding and ... [more ▼]

This report is part of a research initiative entitled Mapping Educational Paths of Youth Workers and Gathering Knowledge on Youth Work. Its main objective is to contribute to a better understanding and sharing of information about the education and training of youth workers across Europe and what employment/ career paths it prepares them for. The data collected will be part of a report by the EU-CoE youth partnership. [less ▲]

Detailed reference viewed: 12 (0 UL)
Full Text
See detailTwo new projects on the Early Cold War period of European Integration
Paravantis, Spero UL

Report (2016)

Core Junior Web Page Announcement

Detailed reference viewed: 13 (1 UL)
Full Text
See detailShape Optimization Directly from CAD: an Isogeometric Boundary Element Approach Using T-splines
Lian, Haojie; Pierre, Kerfriden; Bordas, Stéphane UL

Report (2016)

Detailed reference viewed: 129 (4 UL)
Full Text
See detailDesign of Automotive Road Racing Rim with Aid of Topology Optimization
MARIN, Laurent; Kedziora, Slawomir UL

Report (2016)

A goal of this project was do develop a new good-looking racing rim of a sport car which would be lighter than existing ones. To achieve the goal, lightweight magnesium ally Mg ZK60-T5 was applied for the ... [more ▼]

A goal of this project was do develop a new good-looking racing rim of a sport car which would be lighter than existing ones. To achieve the goal, lightweight magnesium ally Mg ZK60-T5 was applied for the rim and its preliminary shape was developed employing topology optimisation. The rim was designed for forging technology; this means that it had to have all manufacturing features required by that production process. Basing on a literature review, loads, boundary conditions and structural requirements were estab-lished which were crucial for a farther development process. The initial design was created by means of the topology optimisation and then a parametric model was developed using a CAD system. As a next step, a first part of validation were done employing FEA in order to meet strength and stiffness targets, some modifications of the CAD model were imposed. As the last step, the final validation was done by means of simply fatigue assessment. The optimisa-tion and FEA were completed using Hyperworks 14/ Inspire 2015 software and the CAD model em-ploying Autodesk Inventor 2015. The results shows that the rim design meet theoretically all structural requirements and a good-looking shape was reached. Total mass of 7.9 kg of the designed rim is obtained, which means a re-duction about 1.8 kg with comparison with a reference rim. The 3D model and a technical drawing are completed; this means that the rim can be sent to a production phase. The results of the project show also that the topology optimisation technology provided by Hyper-works and the advanced CAD system can be used to generate competitive designs with any design offices without any difficulties. [less ▲]

Detailed reference viewed: 63 (8 UL)
Full Text
See detailTESMA : Requirements, Design and Implementation of a Teaching Specification, Management and Assessment tool
Jahic, Benjamin UL

Report (2016)

The definition and organisation of programs related to their courses of educational institutions is a very complex and exhaustive task. There is a demand for such a solution by the educational ... [more ▼]

The definition and organisation of programs related to their courses of educational institutions is a very complex and exhaustive task. There is a demand for such a solution by the educational institutions, as they need a detailed program descriptions for students and instructors. This task gets even more complicated if these programs and courses needs to be certified according to some international learning standards. At the moment, the availability of such methods or tools is very limited, except for some ad-hoc guidelines, which are use by some few universities, e.g. the Cornell University. Most of the institutions (e.g. University of Luxembourg) allows the professor to us their own methods for specifying their courses. Hence, most of the institutions are sharing similar problems, but using their own defined methods (e.g. naming conventions for its programs). At an university, professors are working in various domains and using therefore their own methods for specifying their courses, which results often in an incomplete program and course description. Methods such as SWEBOK (Software Engineering Body of Knowledge) and CS2103 (Computer Science Curricula 2013) which are program certifications according to an international learning standard are almost not known and used. Thus, programs and courses from different institution cannot be compared, since there is no common structure and process for specifying them. In this master thesis, we present TESMA (Tool for Educational Specification Management and Assessment of teaching programs), a tool based on a domain-specific language, which is dedicated to the teaching domain, for specifying, managing, and assessing programs. The Messir (Scientific Approach to Requirements Engineering) development method has been used for defining the concept and the requirements of the tool. Our research concentrates on the domain-specific language (DSL) in order to define requirements and improving the quality of the DSL’s. We focus on the development of an intuitive and maintainable domain-specific language, usable by people coming from different domains, e.g. software engineers, natural sciences, social sciences, linguistic, and so on. This thesis describes the requirements, the concepts, the realisation, and implementation of the tool, which are based on a domainspecific language of high quality for specifying programs. The quality of our DSL is assessed by a complete used cases related to the University of Luxembourg. [less ▲]

Detailed reference viewed: 61 (29 UL)
See detailProjet Accompagnement. Politiques et dispositifs au Luxembourg et à l’étranger visant l’amélioration de la qualité des établissements scolaires. Rapport synthétique.
Dierendonck, Christophe UL; Kerger, Sylvie UL; Milmeister, Marianne UL et al

Report (2016)

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la ... [more ▼]

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la division du SCRIPT (Service de coordination de la recherche et de l’innovation pédagogiques et technologiques), et conduite par l’Université du Luxembourg. L’étude poursuit quatre objectifs spécifiques : (1) dresser un état des lieux du soutien et de l’accompagnement actuellement proposés au Luxembourg aux écoles fondamentales dans leurs démarches de développement de la qualité scolaire, (2) décrire ce qui est mis en œuvre dans d’autres systèmes scolaires pour poursuivre cet objectif, (3) identifier des éléments intéressants et formuler des perspectives pour, le cas échéant, améliorer le dispositif actuel et (4) examiner l’intérêt et les conditions de réalisation d’études ultérieures en matière d’accompagnement des établissements scolaires au Luxembourg. [less ▲]

Detailed reference viewed: 46 (11 UL)
See detailProjet Accompagnement. Description de dispositifs étrangers visant l'amélioration de la qualité des établissements scolaires.
Dierendonck, Christophe UL; Kerger, Sylvie UL; Milmeister, Marianne UL et al

Report (2016)

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la ... [more ▼]

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la division du SCRIPT (Service de coordination de la recherche et de l’innovation pédagogiques et technologiques), et conduite par l’Université du Luxembourg. L’étude poursuit quatre objectifs spécifiques : (1) dresser un état des lieux du soutien et de l’accompagnement actuellement proposés au Luxembourg aux écoles fondamentales dans leurs démarches de développement de la qualité scolaire, (2) décrire ce qui est mis en œuvre dans d’autres systèmes scolaires pour poursuivre cet objectif, (3) identifier des éléments intéressants et formuler des perspectives pour, le cas échéant, améliorer le dispositif actuel et (4) examiner l’intérêt et les conditions de réalisation d’études ultérieures en matière d’accompagnement des établissements scolaires au Luxembourg. [less ▲]

Detailed reference viewed: 25 (5 UL)
See detailProjet Accompagnement. L'enquête par questionnaire auprès des présidents et des membres de comités d'école.
Dierendonck, Christophe UL; Kerger, Sylvie UL; Milmeister, Marianne UL et al

Report (2016)

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la ... [more ▼]

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la division du SCRIPT (Service de coordination de la recherche et de l’innovation pédagogiques et technologiques), et conduite par l’Université du Luxembourg. L’étude poursuit quatre objectifs spécifiques : (1) dresser un état des lieux du soutien et de l’accompagnement actuellement proposés au Luxembourg aux écoles fondamentales dans leurs démarches de développement de la qualité scolaire, (2) décrire ce qui est mis en œuvre dans d’autres systèmes scolaires pour poursuivre cet objectif, (3) identifier des éléments intéressants et formuler des perspectives pour, le cas échéant, améliorer le dispositif actuel et (4) examiner l’intérêt et les conditions de réalisation d’études ultérieures en matière d’accompagnement des établissements scolaires au Luxembourg. [less ▲]

Detailed reference viewed: 26 (2 UL)
See detailProjet Accompagnement. La consultation par entretiens des acteurs-clés de l'accompagnement des écoles au Luxembourg.
Dierendonck, Christophe UL; Kerger, Sylvie UL; Milmeister, Marianne UL et al

Report (2016)

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la ... [more ▼]

Le projet Accompagnement est une courte recherche de six mois (janvier à juin 2016), financée par le MENJE (Ministère de l’Education nationale, de l’Enfance et de la Jeunesse), et plus précisément par la division du SCRIPT (Service de coordination de la recherche et de l’innovation pédagogiques et technologiques), et conduite par l’Université du Luxembourg. L’étude poursuit quatre objectifs spécifiques : (1) dresser un état des lieux du soutien et de l’accompagnement actuellement proposés au Luxembourg aux écoles fondamentales dans leurs démarches de développement de la qualité scolaire, (2) décrire ce qui est mis en œuvre dans d’autres systèmes scolaires pour poursuivre cet objectif, (3) identifier des éléments intéressants et formuler des perspectives pour, le cas échéant, améliorer le dispositif actuel et (4) examiner l’intérêt et les conditions de réalisation d’études ultérieures en matière d’accompagnement des établissements scolaires au Luxembourg. [less ▲]

Detailed reference viewed: 30 (2 UL)
Full Text
See detailWatch out for This Commit! A Study of Influential Software Changes
Li, Daoyuan UL; Li, Li UL; Kim, Dongsun UL et al

Report (2016)

One single code change can significantly influence a wide range of software systems and their users. For example, 1) adding a new feature can spread defects in several modules, while 2) changing an API ... [more ▼]

One single code change can significantly influence a wide range of software systems and their users. For example, 1) adding a new feature can spread defects in several modules, while 2) changing an API method can improve the performance of all client programs. Developers often may not clearly know whether their or others’ changes are influential at commit time. Rather, it turns out to be influential after affecting many aspects of a system later. This paper investigates influential software changes and proposes an approach to identify them early, i.e., immediately when they are applied. We first conduct a post- mortem analysis to discover existing influential changes by using intuitions such as isolated changes and changes referred by other changes in 10 open source projects. Then we re-categorize all identified changes through an open-card sorting process. Subsequently, we conduct a survey with 89 developers to confirm our influential change categories. Finally, from our ground truth we extract features, including metrics such as the complexity of changes, terms in commit logs and file centrality in co-change graphs, to build ma- chine learning classifiers. The experiment results show that our prediction model achieves overall with random samples 86.8% precision, 74% recall and 80.4% F-measure respectively. [less ▲]

Detailed reference viewed: 105 (19 UL)
Full Text
See detailBayesian inference for material parameter identification
Rappel, Hussein UL; Beex, Lars UL; Hale, Jack UL et al

Report (2016)

Detailed reference viewed: 67 (13 UL)
Full Text
See detailStatic Analysis of Android Apps: A Systematic Literature Review
Li, Li UL; Bissyande, Tegawendé François D Assise UL; Papadakis, Mike UL et al

Report (2016)

Context: Static analysis approaches have been proposed to assess the security of Android apps, by searching for known vulnerabilities or actual malicious code. The literature thus has proposed a large ... [more ▼]

Context: Static analysis approaches have been proposed to assess the security of Android apps, by searching for known vulnerabilities or actual malicious code. The literature thus has proposed a large body of works, each of which attempts to tackle one or more of the several challenges that program analyzers face when dealing with Android apps. Objective: We aim to provide a clear view of the state-of-the-art works that statically analyze Android apps, from which we highlight the trends of static analysis approaches, pinpoint where the focus has been put and enumerate the key aspects where future researches are still needed. Method: We have performed a systematic literature review which involves studying around 90 research papers published in software engineering, programming languages and security venues. This review is performed mainly in five dimensions: problems targeted by the approach, fundamental techniques used by authors, static analysis sensitivities considered, android characteristics taken into account and the scale of evaluation performed. Results: Our in-depth examination have led to several key findings: 1) Static analysis is largely performed to uncover security and privacy issues; 2) The Soot framework and the Jimple intermediate representation are the most adopted basic support tool and format, respectively; 3) Taint analysis remains the most applied technique in research approaches; 4) Most approaches support several analysis sensitivities, but very few approaches consider path-sensitivity; 5) There is no single work that has been proposed to tackle all challenges of static analysis that are related to Android programming; and 6) Only a small portion of state-of-the-art works have made their artifacts publicly available. Conclusion: The research community is still facing a number of challenges for building approaches that are aware altogether of implicit-Flows, dynamic code loading features, reflective calls, native code and multi-threading, in order to implement sound and highly precise static analyzers. [less ▲]

Detailed reference viewed: 806 (25 UL)
Full Text
See detailGemRBAC-DSL: a High-level Specification Language for Role-based Access Control Policies
Ben Fadhel, Ameni UL; Bianculli, Domenico UL; Briand, Lionel UL

Report (2016)

A role-based access control (RBAC) policy restricts a user to perform operations based on her role within an organization. Several RBAC models have been proposed to represent different types of RBAC ... [more ▼]

A role-based access control (RBAC) policy restricts a user to perform operations based on her role within an organization. Several RBAC models have been proposed to represent different types of RBAC policies. However, the expressiveness of these models has not been matched by specification languages for RBAC policies. Indeed, existing policy specification languages do not support all the types of RBAC policies defined in the literature. In this paper we aim to bridge the gap between highly-expressive RBAC models and policy specification languages, by presenting GemRBAC-DSL, a new specification language designed on top of an existing, generalized conceptual model for RBAC. The language sports a syntax close to natural language, to encourage its adoption among practitioners. We also define semantic checks to detect conflicts and inconsistencies among the policies written in a GemRBAC-DSL specification. We show how the semantics of GemRBAC-DSL can be expressed in terms of an existing formalization of RBAC policies as OCL (Object Constraint Language) constraints on the corresponding RBAC conceptual model. This formalization paves the way to define a model-driven approach for the enforcement of policies written in GemRBAC-DSL. [less ▲]

Detailed reference viewed: 107 (22 UL)
Full Text
See detailIsogeometric boundary element methods for linear elastic fracture mechanics
Peng, Xuan; Atroshchenko, Elena; Kerfriden, Pierre et al

Report (2016)

Detailed reference viewed: 280 (20 UL)
Full Text
See detailThe Case for FIFO Real-Time Scheduling
Altmeyer, Sebastian UL; Sundharam, Sakthivel Manikandan UL; Navet, Nicolas UL

Report (2016)

Selecting the right scheduling policy is a crucial issue in the development of an embedded real-time application. Whereas scheduling policies are typically judged according to their ability to schedule ... [more ▼]

Selecting the right scheduling policy is a crucial issue in the development of an embedded real-time application. Whereas scheduling policies are typically judged according to their ability to schedule task sets at a high processor utilizations, other concerns, such as predictability and simplicity are often overlooked.In this paper, we argue that FIFO scheduling with offsets is a suitable choice when these concerns play a key role. To this end, we examine the predictability of FIFO, present a schedulability analysis for it and evaluate both, performance and predictability of FIFO scheduling with and without offsets. Our results show that FIFO with offsets exhibits competitive performance for task with regular periods, at an unmatched predictability. [less ▲]

Detailed reference viewed: 290 (51 UL)
Full Text
See detail2015 Lab report - Legato report 001
Bordas, Stéphane UL

Report (2016)

Detailed reference viewed: 409 (10 UL)
Full Text
See detailA Representation Theorem for Abstract Cumulative Aggregation
Ambrossio, Diego Agustin UL; Parent, Xavier UL; van der Torre, Leon UL

Report (2016)

From any two conditional obligations “X if A” and “Y if B”, cumulative aggregation derives the combined obligation “X ∪ Y if A ∪ (B \ X)”, whereas simple aggregation derives the obligation “X ∪ Y if A ∪ ... [more ▼]

From any two conditional obligations “X if A” and “Y if B”, cumulative aggregation derives the combined obligation “X ∪ Y if A ∪ (B \ X)”, whereas simple aggregation derives the obligation “X ∪ Y if A ∪ B”. We propose FC systems consisting of cumulative aggregation together with factual detachment, and we give a representation result for FC systems, as well as for FA systems consisting of simple aggregation together with factual detachment. We relate FC and FA systems to each other and to input/output logics recently introduced by Parent and van der Torre. [less ▲]

Detailed reference viewed: 110 (35 UL)
Full Text
See detailLean Model-Driven Development through Model-Interpretation: the CPAL design flow
Navet, Nicolas UL; Fejoz, Loïc; Havet, Lionel et al

Report (2015)

We introduce a novel Model-Driven Development (MDD) flow which aims at more simplicity, more intuitive programming, quicker turnaround time and real-time predictability by leveraging the use of model ... [more ▼]

We introduce a novel Model-Driven Development (MDD) flow which aims at more simplicity, more intuitive programming, quicker turnaround time and real-time predictability by leveraging the use of model-interpretation and providing the language abstractions needed to argue about the timing correctness on a high-level. The MDD flow is built around a language called Cyber-Physical Action Language (CPAL). CPAL serves to describe both the functional behaviour of activities (i.e., the code of the function itself) as well as the functional architecture of the system (i.e., the set of functions, how they are activated, and the data flows among the functions). CPAL is meant to support two use-cases. Firstly, CPAL is a development and design space exploration environment for CPS with main features being the formal description, the editing, graphical representation and simulation of CPS models. Secondly, CPAL is a real-time execution platform. The vision behind CPAL is that a model is executed and verified in simulation mode on a workstation and the same model can be later run on an embedded board with a timing-equivalent run-time time behaviour. [less ▲]

Detailed reference viewed: 101 (7 UL)
Full Text
See detailIsogeometric boundary element methods for three dimensional fatigue crack growth
Peng, Xuan; Atroshchenko, Elena; Kerfriden, Pierre et al

Report (2015)

The isogeometric boundary element method (IGABEM) based on NURBS is adopted to model fracture problem in 3D. The NURBS basis functions are used in both crack representation and physical quantity ... [more ▼]

The isogeometric boundary element method (IGABEM) based on NURBS is adopted to model fracture problem in 3D. The NURBS basis functions are used in both crack representation and physical quantity approximation. A stable quadrature scheme for singular integration is proposed to enhance the robustness of the method in dealing with highly distorted element. The convergence study in crack opening displacement is performed for penny-shaped crack and elliptical crack. Two ways to extract stress intensity factors (SIFs), the contour $M$ integral and virtual crack closure integral, are implemented based on the framework of dual integral equations. An algorithm is outlined and validated to be stable for fatigue crack growth, thanks to the smoothness not only in crack geometry but also in stress/SIFs solution brought by IGABEM. [less ▲]

Detailed reference viewed: 344 (14 UL)
Full Text
See detailBIX – Der Bibliotheksindex:
Pausch, Marie-Pierre UL; Park, Beth Anne UL; Ourth, Annette UL

Report (2015)

Detailed reference viewed: 89 (35 UL)
Full Text
See detailHarvesting Fix Hints in the History of Bugs
Bissyande, Tegawendé François D Assise UL

Report (2015)

In software development, fixing bugs is an im- portant task that is time consuming and cost-sensitive. While many approaches have been proposed to automatically detect and patch software code, the ... [more ▼]

In software development, fixing bugs is an im- portant task that is time consuming and cost-sensitive. While many approaches have been proposed to automatically detect and patch software code, the strategies are limited to a set of identified bugs that were thoroughly studied to define their properties. They thus manage to cover a niche of faults such as infinite loops. We build on the assumption that bugs, and the associated user bug reports, are repetitive and propose a new approach of fix recommendations based on the history of bugs and their associated fixes. In our approach, once a bug is reported, it is automatically compared to all previously fixed bugs using information retrieval techniques and machine learning classification. Based on this comparison, we recommend top-k fix actions, identified from past fix examples, that may be suitable as hints for software developers to address the new bug [less ▲]

Detailed reference viewed: 16 (0 UL)
Full Text
See detailA Study of Potential Component Leaks in Android Apps
Li, Li UL; Allix, Kevin UL; Li, Daoyuan UL et al

Report (2015)

We discuss the capability of a new feature set for malware detection based on potential component leaks (PCLs). PCLs are defined as sensitive data-flows that involve Android inter-component communications ... [more ▼]

We discuss the capability of a new feature set for malware detection based on potential component leaks (PCLs). PCLs are defined as sensitive data-flows that involve Android inter-component communications. We show that PCLs are common in Android apps and that malicious applications indeed manipulate significantly more PCLs than benign apps. Then, we evaluate a machine learning-based approach relying on PCLs. Experimental validation show high performance with 95% precision for identifying malware, demonstrating that PCLs can be used for discriminating malicious apps from benign apps. By further investigating the generalization ability of this feature set, we highlight an issue often overlooked in the Android malware detection community: Qualitative aspects of training datasets have a strong impact on a malware detector’s performance. Furthermore, this impact cannot be overcome by simply increasing the Quantity of training material. [less ▲]

Detailed reference viewed: 95 (1 UL)
Full Text
See detailLes langues dans les offres d'emploi au Luxembourg (1984-2014)
Pigeron-Piroth, Isabelle UL; Fehlen, Fernand UL

Report (2015)

Cette étude propose une analyse des demandes linguistiques dans les offres d’emploi au Luxembourg dans deux médias différents : 1) À partir d’un échantillon d’offres du Luxemburger Wort portant sur la ... [more ▼]

Cette étude propose une analyse des demandes linguistiques dans les offres d’emploi au Luxembourg dans deux médias différents : 1) À partir d’un échantillon d’offres du Luxemburger Wort portant sur la période 1984-2014, elle décrit l’évolution des compétences linguistiques exigées ou souhaitées sur le marché du travail du Luxembourg. 2) Pour tenir compte de l’importance croissante des recrutements en ligne, une deuxième étude porte sur un corpus d’offres publiées sur le site Internet Jobs.lu. La prise en compte de ces deux sources permet de montrer une segmentation linguistique entre les différentes branches d’activité et une augmentation des demandes langagières explicites au fil des 30 dernières années. [less ▲]

Detailed reference viewed: 621 (129 UL)
Full Text
See detailModel-Driven Security based on A Unified System of Security Design Patterns
Nguyen, Phu Hong UL

Report (2015)

Model-Driven Security (MDS) for secure systems development still has limitations to be more applicable in practice. A recent systematic review of MDS shows that current MDS approaches have not dealt with ... [more ▼]

Model-Driven Security (MDS) for secure systems development still has limitations to be more applicable in practice. A recent systematic review of MDS shows that current MDS approaches have not dealt with multiple security concerns system- atically. Besides, catalogs of security patterns which can address multiple security concerns have not been applied efficiently. This paper presents an MDS approach based on a unified System of Security design Patterns (SoSPa). In SoSPa, security design patterns are collected, specified as reusable aspect models to form a coherent system of them that guides developers in systematically addressing multiple security concerns. SoSPa consists of not only interrelated security design patterns but also a refinement process towards their application. We applied SoSPa to design the security of crisis management systems. The result shows that multiple security concerns in the case study have been addressed by systematically integrating different security solutions. [less ▲]

Detailed reference viewed: 129 (13 UL)
Full Text
See detailAn Extensive Systematic Review on Model-Driven Development of Secure Systems
Nguyen, Phu Hong UL

Report (2015)

Context: Model-Driven Security (MDS) is as a specialised Model-Driven Engineering research area for supporting the development of secure systems. Over a decade of research on MDS has resulted in a large ... [more ▼]

Context: Model-Driven Security (MDS) is as a specialised Model-Driven Engineering research area for supporting the development of secure systems. Over a decade of research on MDS has resulted in a large number of publications. Objective: To provide a detailed analysis of the state of the art in MDS, a systematic literature review (SLR) is essential. Method: We conducted an extensive SLR on MDS. Derived from our research questions, we designed a rigorous, extensive search and selection process to identify a set of primary MDS studies that is as complete as possible. Our three-pronged search process consists of automatic searching, manual searching, and snowballing. After discovering and considering more than thousand relevant papers, we identified, strictly selected, and reviewed 108 MDS publications. Results: The results of our SLR show the overall status of the key artefacts of MDS, and the identified primary MDS studies. E.g. regarding security modelling artefact, we found that developing domain-specific languages plays a key role in many MDS approaches. The current limitations in each MDS artefact are pointed out and corresponding potential research directions are suggested. Moreover, we categorise the identified primary MDS studies into 5 principal MDS studies, and other emerging or less common MDS studies. Finally, some trend analyses of MDS research are given. Conclusion: Our results suggest the need for addressing multiple security concerns more systematically and simultaneously, for tool chains supporting the MDS development cycle, and for more empirical studies on the application of MDS methodologies. To the best of our knowledge, this SLR is the first in the field of Software Engineering that combines a snowballing strategy with database searching. This combination has delivered an extensive literature study on MDS. [less ▲]

Detailed reference viewed: 35 (5 UL)
Full Text
See detailComputational Mechanics Lab Report 2013-2014
Bordas, Stéphane UL

Report (2015)

This is the report of the Computational Mechanics Lab led by Prof. Stéphane Bordas

Detailed reference viewed: 1141 (71 UL)
Full Text
See detailScience Productivity, Higher Education Development and the Knowledge Society (SPHERE Project) Final Report
Baker, David P.; Crist, John T.; Zhang, Liang et al

Report (2015)

This project created and analyzed a new, large global dataset on scientific journal articles, published between 1900 and 2011, and a series of case studies to examine how systems of higher education ... [more ▼]

This project created and analyzed a new, large global dataset on scientific journal articles, published between 1900 and 2011, and a series of case studies to examine how systems of higher education developed and grew nations’ capacity for scientific research. The analysis resulted in a series of new insights about global scientific production that were only possible with a consideration of long-term trends. First, despite predictions as early as the 1960s that the growth rate of “big science” would slow, the dataset shows in fact that “big science” started a phase of exponential growth in the early 1960s that has continued unabated for decades. “Big science” has transformed into “mega-global science” and the trends of global diffusion and regional differentiation began much earlier in the 20th century than is commonly understood. Second, the analysis of rates of regional journal article production also depicts clear shifts in the competition for ascendancy in scientific production. For the first half of the 20th century, global competition for scientific impact was primarily an Atlantic battle between the top producers of Europe (Germany, France, and the U.K.) and the United States. The locus of competition shifted by the, end of the 20th century to a contest between the current research “superpower, ” the United States, and the fast-growing producer, China, along with the many less populous countries of Western Europe with their highly productive science systems. With the contributions of other East Asian, high volume producers such as Japan and South Korea in the later decades of the 20th century, and simultaneous slowing of research production in U.S. science, the center of gravity for research production has been pulled eastward for the past two decades. Third, while science may indeed be an inherently global and collaborative enterprise, the trend toward global collaboration of authors is a relatively recent one. Historically, one-third of all research articles worldwide result from international collaboration, and less than 26 percent are the product of one researcher alone. In 1980 however only about 2 percent of all SCIE publications involved a collaboration across international lines. Three decades later this proportion is eleven times what it was in 1980. Finally, the study also concluded that overall volume of production is not a sufficient measure of scientific capacity by itself. When adjusting for the size of population and the economy the proportion of GDP spent on R&D or the number of researchers some smaller countries (especially in Europe) are more productive on a per capita basis than mid-sized or even larger ones. Similarly the ratio of investment in science to scientific production is much higher in the high volume producers than it is in some small states. While output is smaller in these states, they have maximized R&D investments more efficiently than their larger competitors. [less ▲]

Detailed reference viewed: 199 (23 UL)
Full Text
See detailGradient Smoothing in Finite Elasticity: near-incompressibility
Lee, Chang-Kye; Bordas, Stéphane UL; Kerfriden, Pierre

Report (2015)

Detailed reference viewed: 81 (9 UL)
Full Text
See detailA Comprehensive Modeling Framework for Role-based Access Control Policies
Ben Fadhel, Ameni UL; Bianculli, Domenico UL; Briand, Lionel UL

Report (2014)

Prohibiting unauthorized access to critical resources and data has become a major requirement for enterprises. Access control (AC) mechanisms manage requests from users to access system resources; the ... [more ▼]

Prohibiting unauthorized access to critical resources and data has become a major requirement for enterprises. Access control (AC) mechanisms manage requests from users to access system resources; the access is granted or denied based on authorization policies defined within the enterprise. One of the most used AC paradigms is role-based access control (RBAC). In RBAC, access rights are determined based on the user's role, e.g., her job or function in the enterprise. Many different types of RBAC authorization policies have been proposed in the literature, each one accompanied by the corresponding extension of the original RBAC model. However, there is no unified framework that can be used to define all these types of RBAC policies in a coherent way, using a common model. Moreover, these types of policies and their corresponding models are scattered across multiple sources and sometimes the concepts are expressed ambiguously. This situation makes it difficult for researchers to understand the state of the art in a coherent manner; furthermore, practitioners may experience severe difficulties when selecting the relevant types of policies to be implemented in their systems based on the available information. There is clearly a need for organizing the various types of RBAC policies systematically, based on a unified framework, and to formalize them to enable their operationalization. In this paper we propose a model-driven engineering (MDE) approach, based on UML and the Object Constraint Language (OCL), to enable the precise specification and verification of such policies. More specifically, we first present a taxonomy of the various types of RBAC authorization policies proposed in the literature. We also propose the GemRBAC model, a generalized model for RBAC that includes all the entities required to define the classified policies. This model is a conceptual model that can also serve as data model to operationalize data collection and verification. Lastly, we formalize the classified RBAC policies as OCL constraints on the GemRBAC model. To facilitate such operationalization, we make publicly available online the ECore version of the GemRBAC model and the OCL constraints corresponding to the classified RBAC policies. [less ▲]

Detailed reference viewed: 436 (174 UL)
Full Text
See detailEcho iTEO. Sprachräume
Kirsch, Claudine UL; Gretsch, Gérard UL

Report (2014)

Detailed reference viewed: 37 (2 UL)
Full Text
See detailShape optimisation directly from CAD: an isogeometric boundary element approach
Lian, Haojie; Bordas, Stéphane UL; Kerfriden, Pierre

Report (2014)

Detailed reference viewed: 51 (4 UL)
Full Text
See detailError controlled adaptive multiscale method for fracture in polycrystalline materials
Akbari Rahimabadi, Ahmad; Kerfriden, Pierre; Bordas, Stéphane UL

Report (2014)

A lack of separation of scales is the major hurdle hampering predictive and computationally tractable simulations of fracture over multiple scales. In this thesis an adaptive multiscale method is ... [more ▼]

A lack of separation of scales is the major hurdle hampering predictive and computationally tractable simulations of fracture over multiple scales. In this thesis an adaptive multiscale method is presented in an attempt to address this challenge. This method is set in the context of FE2 Feyel and Chaboche [2000] for which computational homogenisation breaks down upon loss of material stability (softening). The lack of scale separation due to the coalescence of microscopic cracks in a certain zone is tackled by a full discretisation of the microstructure in this zone. Polycrystalline materials are considered with cohesive cracks along the grain boundaries as a model problem. Adaptive mesh re nement of the coarse region and adaptive initiation and growth of fully resolved regions are performed based on discretisation error and homogenisation error criteria, respectively. In order to follow sharp snap-backs in load-displacement paths, a local arc-length technique is developed for the adaptive multiscale method. The results are validated against direct numerical simulation [less ▲]

Detailed reference viewed: 54 (1 UL)
Full Text
See detailTriple Graph Grammars in the Large for Translating Satellite Procedures - Extended Version
Hermann, Frank UL; Gottmann, Susann UL; Nachtigall, Nico UL et al

Report (2014)

Software translation is a challenging task. Several requirements are important - including automation of the execution, maintainability of the translation patterns, and, most importantly, reliability ... [more ▼]

Software translation is a challenging task. Several requirements are important - including automation of the execution, maintainability of the translation patterns, and, most importantly, reliability concerning the correctness of the translation. Triple graph grammars (TGGs) have shown to be an intuitive, wellde ned technique for model translation. In this paper, we leverage TGGs for industry scale software translations. The approach is implemented using the Eclipse-based graph transformation tool Henshin and has been successfully applied in a large industrial project with the satellite operator SES on the translation of satellite control procedures. We evaluate the approach regarding requirements from the project and performance on a complete set of procedures of one satellite. [less ▲]

Detailed reference viewed: 208 (49 UL)
Full Text
See detailAutomatically Exploiting Potential Component Leaks in Android Applications
Li, Li UL; Bartel, Alexandre UL; Klein, Jacques UL et al

Report (2014)

We present PCLeaks, a tool based on inter- component communication (ICC) vulnerabilities to perform data-flow analysis on Android applications to find potential component leaks (e.g., another component ... [more ▼]

We present PCLeaks, a tool based on inter- component communication (ICC) vulnerabilities to perform data-flow analysis on Android applications to find potential component leaks (e.g., another component can potentially exploit the leak). To evaluate our approach, we run PCLeaks on 2000 apps, randomly selected from Google Play store. PCLeaks reports 986 potential component leaks in 185 apps. For each leak reported by PCLeaks, PCLeaksValidator automatically generates an Android app which tries to exploit the leak. By manually running a subset of the generated apps, we find that 75% of the reported leaks are exploitable leaks. [less ▲]

Detailed reference viewed: 276 (29 UL)
Full Text
See detailA two-dimensional isogeometric boundary element method for linear elastic fracture
Peng, Xuan; Atroshchenko, Elena; Kulasegaram, Sivakumar et al

Report (2014)

Detailed reference viewed: 80 (5 UL)
Full Text
See detailI know what leaked in your pocket: uncovering privacy leaks on Android Apps with Static Taint Analysis
Li, Li UL; Bartel, Alexandre UL; Klein, Jacques UL et al

Report (2014)

Android applications may leak privacy data carelessly or maliciously. In this work we perform inter-component data-flow analysis to detect privacy leaks between components of Android applications. Unlike ... [more ▼]

Android applications may leak privacy data carelessly or maliciously. In this work we perform inter-component data-flow analysis to detect privacy leaks between components of Android applications. Unlike all current approaches, our tool, called IccTA, propagates the context between the components, which improves the precision of the analysis. IccTA outperforms all other available tools by reaching a precision of 95.0% and a recall of 82.6% on DroidBench. Our approach detects 147 inter-component based privacy leaks in 14 applications in a set of 3000 real-world applications with a precision of 88.4%. With the help of ApkCombiner, our approach is able to detect inter-app based privacy leaks. [less ▲]

Detailed reference viewed: 121 (19 UL)
Full Text
See detailInsights and Lessons Learned from Analyzing ICSE 2014 Survey and Review Data
Briand, Lionel UL; van der Hoek, André

Report (2014)

Detailed reference viewed: 2933 (43 UL)
Full Text
See detailA Model-Driven Approach to Offline Trace Checking of Temporal Properties with OCL
Dou, Wei UL; Bianculli, Domenico UL; Briand, Lionel UL

Report (2014)

Offline trace checking is a procedure for evaluating requirements over a log of events produced by a system. The goal of this paper is to present a practical and scalable solution for the offline checking ... [more ▼]

Offline trace checking is a procedure for evaluating requirements over a log of events produced by a system. The goal of this paper is to present a practical and scalable solution for the offline checking of the temporal requirements of a system, which can be used in contexts where model-driven engineering is already a practice, where temporal specifications should be written in a domain-specific language not requiring a strong mathematical background, and where relying on standards and industry-strength tools for property checking is a fundamental prerequisite. The main contributions are: the TemPsy language, a domain-specific specification language based on common property specification patterns, and extended with new constructs; a model-driven offline trace checking procedure based on the mapping of requirements written in TemPsy into OCL (Object Constraint Language) constraints on a conceptual model on execution traces, which can be evaluated using an OCL checker; the implementation of this trace checking procedure in the TemPsy-Check tool; the evaluation of the scalability of TemPsy-Check and its comparison to a state-of-the-art alternative technology. The proposed approach has been applied to a case study developed in collaboration with a public service organization, active in the domain of business process modeling for eGovernment. [less ▲]

Detailed reference viewed: 391 (121 UL)
Full Text
See detailOCLR: a More Expressive, Pattern-based Temporal Extension of OCL
Dou, Wei UL; Bianculli, Domenico UL; Briand, Lionel UL

Report (2014)

Modern enterprise information systems often require to specify their functional and non-functional (e.g., Quality of Service) requirements using expressions that contain temporal constraints ... [more ▼]

Modern enterprise information systems often require to specify their functional and non-functional (e.g., Quality of Service) requirements using expressions that contain temporal constraints. Specification approaches based on temporal logics demand a certain knowledge of mathematical logic, which is difficult to find among practitioners; moreover, tool support for temporal logics is limited. On the other hand, a standard language such as the Object Constraint Language (OCL), which benefits from the availability of several industrial-strength tools, does not support temporal expressions. In this paper we propose OCLR, an extension of OCL with support for temporal constraints based on well-known property specification patterns. With respect to previous extensions, we add support for referring to a specific occurrence of an event as well as for indicating a time distance between events and/or scope boundaries. The proposed extension defines a new syntax, very close to natural language, paving the way for a rapid adoption by practitioners. We show the application of the language in a case study in the domain of eGovernment, developed in collaboration with a public service partner. [less ▲]

Detailed reference viewed: 219 (83 UL)
Full Text
See detailSentiment Barometer in Financial News
Schommer, Christoph UL

Report (2014)

This booklet is a collection of project reports written by graduate students, who have participated the course "Machine Learning" in Winter Term 2013/14. Here, we have concerned Financial News Documents ... [more ▼]

This booklet is a collection of project reports written by graduate students, who have participated the course "Machine Learning" in Winter Term 2013/14. Here, we have concerned Financial News Documents regarding the Irish Financial Crisis in the years of 2009 - 2013. We have studied different forms of sentiments, for example with StoryTakes, Alerts, Headlines, authors, and others. [less ▲]

Detailed reference viewed: 92 (8 UL)
Full Text
See detailEvaluating the HPC Performance and Energy-Efficiency of Intel and ARM-based systems with synthetic and bioinformatics workloads
Plugaru, Valentin UL; Varrette, Sébastien UL; Pinel, Frédéric UL et al

Report (2014)

The increasing demand for High Performance Computing (HPC) paired with the higher power requirements of the ever-faster systems has led to the search for both performant and more energy-efficient ... [more ▼]

The increasing demand for High Performance Computing (HPC) paired with the higher power requirements of the ever-faster systems has led to the search for both performant and more energy-efficient architectures. This article compares and contrasts the performance and energy efficiency of two modern, traditional Intel Xeon and low power ARM-based clusters, which are tested with the recently developed High Performance Conjugate Gradient (HPCG) benchmark and the ABySS, FASTA and MrBayes bioinformatics applications. We show a higher Performance per Watt valuation of the ARM cluster, and lower energy usage during the tests, which does not offset the much faster job completion rate obtained by the Intel cluster, making the latter more suitable for the considered workloads given the disparity in the performance results. [less ▲]

Detailed reference viewed: 105 (19 UL)
Full Text
See detailStrain smoothing technique in 3D for nearly incompressible neo-Hookean material
Lee, Chang-Kye; Mihai, L. Angela; Kerfriden, Pierre et al

Report (2014)

Detailed reference viewed: 128 (12 UL)
Full Text
See detailFunctional Alloy Modules
Gammaitoni, Loïc UL; Kelsen, Pierre UL

Report (2014)

The Alloy language was developed as a lightweight modelling language that allows fully automatic analysis of software design models via SAT solving. The practical application of this type of analysis is ... [more ▼]

The Alloy language was developed as a lightweight modelling language that allows fully automatic analysis of software design models via SAT solving. The practical application of this type of analysis is hampered by two limitations: first, the analysis itself can become quite time consuming when the scopes become even moderately large; second, determining minimal scopes for the entity types (limiting the number of entities of each type) to achieve better running times is itself a non-trivial problem. In this paper we show that for the special case of Alloy modules specifying transformations we may be able to circumvent these limitations. We define the corresponding notion of functional module and define precise conditions under which such functional modules can be efficiently interpreted rather than analysed via SAT solving and we also explain how interpretation of functional Alloy modules can be seamlessly integrated with the SAT-based analysis of other modules. We provide evidence that for complex transformations interpreting functional modules may result in significant time savings. [less ▲]

Detailed reference viewed: 123 (48 UL)
Full Text
See detailGlobal energy minimization for multiple fracture growth
Sutula, Danas; Bordas, Stéphane UL

Report (2013)

Detailed reference viewed: 155 (5 UL)
See detailLes Épreuves Standardisées vues par les acteurs du terrain. Étude exploratoire.
Milmeister, Marianne UL; Milmeister, Paul UL; Weis, Christiane UL

Report (2013)

Afin de dépasser le stade des hypothèses, il a été décidé de récolter des informations quantitatives (au moyen d'un questionnaire à large échelle) et qualitatives (au travers de focus groups) quant à la ... [more ▼]

Afin de dépasser le stade des hypothèses, il a été décidé de récolter des informations quantitatives (au moyen d'un questionnaire à large échelle) et qualitatives (au travers de focus groups) quant à la façon dont sont perçues et utilisées les Épreuves Standardisées. Le but en est de mieux comprendre comment les différents acteurs concernés (directeurs, inspecteurs, enseignants, élèves et parents) perçoivent le dispositif des Épreuves Standardisées et tiennent compte des informations qui leur sont envoyées en retour (rapport NATIONAL, rapport ECOLE, rapport CLASSE, rapports ELEVE). Une attention particulière est portée à la compréhension et l'usage des rapports mis à disposition ainsi qu'aux éventuelles pistes d'amélioration de l'outil proposées par les acteurs concernés. Le présent document synthétise la phase exploratoire de l'étude qualitative (menée en 2013) en présentant (1) les guides d'entretien utilisés (et leur modification) et (2) une première analyse quant aux contenus développés par les personnes interrogées. [less ▲]

Detailed reference viewed: 30 (11 UL)
Full Text
See detailRefinement of AADL models using early-stage analysis methods : An avionics example
Brau, Guillaume UL; Hugues, Jérôme; Navet, Nicolas UL

Report (2013)

Model-Driven Engineering (MDE) is a relevant approach to support the engineering of distributed embedded systems with performance and dependability constraints. MDE involves models definitions and ... [more ▼]

Model-Driven Engineering (MDE) is a relevant approach to support the engineering of distributed embedded systems with performance and dependability constraints. MDE involves models definitions and transformations to cover most of the system life-cycle: design, implementation and Verifi cation & Validation activities towards system quali fication. Still, few works evaluate the early integration of performance evaluation based on architectural models. In this report, we investigate the early-stage use of analysis in AADL modeling. Precisely, we exemplify on an avionics case study how to dimension the data flows for an application distributed over an AFDX network. Based on the insight from this study, we suggest a simple framework and associated techniques to e fficiently support analysis activities in the early-stage design phases. [less ▲]

Detailed reference viewed: 149 (10 UL)
Full Text
See detailPerformance tuning of applications for HPC systems employing Simulated Annealing optimization
Plugaru, Valentin UL; Georgatos, Fotis UL; Varrette, Sébastien UL et al

Report (2013)

Building fast software in an HPC environment raises great challenges as software used for simulation and modelling is generally complex and has many dependencies. Current approaches involve manual tuning ... [more ▼]

Building fast software in an HPC environment raises great challenges as software used for simulation and modelling is generally complex and has many dependencies. Current approaches involve manual tuning of compilation parameters in order to minimize the run time, based on a set of predefined defaults, but such an approach involves expert knowledge, is not scalable and can be very expensive in person-hours. In this paper we propose and develop a modular framework called POHPC that uses the Simulated Annealing meta-heuristic algorithm to automatically search for the optimal set of library options and compilation flags that can give the best execution time for a library-application pair on a selected hardware architecture. The framework can be used in modern HPC clusters using a variety of batch scheduling systems as execution backends for the optimization runs, and will discover optimal combinations as well as invalid sets of options and flags that result in failed builds or application crashes. We demonstrate the optimization of the FFTW library working in conjunction with the high- profile community codes GROMACS and QuantumESPRESSO, whereby the suitability of the technique is validated. [less ▲]

Detailed reference viewed: 110 (30 UL)
Full Text
See detailIn-vehicle communication networks - a historical perspective and review
Navet, Nicolas UL; Simonot-Lion, Françoise

Report (2013)

The use of networks for communications between the Electronic Control Units (ECU) of a vehicle in production cars dates from the beginning of the 90s. The specific requirements of the different car ... [more ▼]

The use of networks for communications between the Electronic Control Units (ECU) of a vehicle in production cars dates from the beginning of the 90s. The specific requirements of the different car domains have led to the development of a large number of automotive networks such as LIN, CAN, CAN FD, FlexRay, MOST, automotive Ethernet AVB, etc.. This report first introduces the context of in-vehicle embedded systems and, in particular, the requirements imposed on the communication systems. Then, a review of the most widely used, as well as the emerging automotive networks is given. Next, the current efforts of the automotive industry on middleware technologies which may be of great help in mastering the heterogeneity, are reviewed, with a special focus on the proposals of the AUTOSAR consortium. Finally, we highlight future trends in the development of automotive communication systems. [less ▲]

Detailed reference viewed: 274 (27 UL)
Full Text
See detailThe Node-Based Smoothed Finite Element Method in nonlinear elasticity
Lee, Chang-Kye; Mihai, Angela; Bordas, Stéphane UL

Report (2013)

Detailed reference viewed: 119 (12 UL)
Full Text
See detailConceptual model and questionnaire: LLLight'in' Europe, Lifelong Learning, Innovation, Growth and Human Capital, Tracks in Europe
Brandi, Ulrik; Elkjær, Bente; Holford, John et al

Report (2013)

This report focuses on reviewing how lifelong learning strategies at an enterprise level influence the development of human capital. The conceptual analysis is to inform and guide semi-structured ... [more ▼]

This report focuses on reviewing how lifelong learning strategies at an enterprise level influence the development of human capital. The conceptual analysis is to inform and guide semi-structured interviews conducted in LLLight’in’Europe’s (FP7) participating enterprises. As a first step towards contributing to the current research and theoretical paradigms in strategic human resource management, the report builds on current models, keeping in mind the intangibles of human capital, the pervasiveness and ubiquitous attributes of situated learning at different levels within enterprises. [less ▲]

Detailed reference viewed: 54 (7 UL)
Full Text
See detailThe King Edward Point Geodetic Observatory
Teferle, Felix Norman UL

Report (2013)

During the period from 7th until 14th February 2013 Norman Teferle (University of Luxembourg) and Seth White (Unavco Inc.) visited King Edward Point (KEP) research station, South Georgia, to establish the ... [more ▼]

During the period from 7th until 14th February 2013 Norman Teferle (University of Luxembourg) and Seth White (Unavco Inc.) visited King Edward Point (KEP) research station, South Georgia, to establish the KEP Geodetic Observatory (KEPGO). The observatory consists of an autonomous, continuous Global Navigation Satellite System (GNSS) station with auxiliary equipment on Brown Mountain, as well as, benchmarks on Brown Mountain and at KEP research station. The primary objective of the observatory is to measure vertical land movements in order to study sea level changes using the KEP tide gauge record or satellite altimeter data. Therefore, the existing tide gauge was connected to the observatory through precise levelling and campaign GNSS observations. The levelling was carried out over the tide gauge itself, two existing United Kingdom Hydrographic Office (UKHO) and four newly established KEPGO tide gauge benchmarks (TGBMs). The GNSS observations were carried out on two benchmarks and their coordinates were computed with respect to the continuous GNSS station on Brown Mountain. Taking the UKHO height information together with the levelling and GNSS results it is suggested that the UKHO TGBM on the jetty may have settled by a few centimetres over the period from 2003 to 2013 and that the UKHO height datum requires a shift of by about -1 m in order to bring it closer to a globally consistent vertical reference system. This technical report details the installation work and analysis carried out during and after the visit. [less ▲]

Detailed reference viewed: 108 (6 UL)
Full Text
See detailSpace-time goal-oriented reduced basis approximation for linear wave equation
Hoang, Khac Chi; Kerfriden, Pierre; Bordas, Stéphane UL

Report (2013)

In this paper, we study numerically the linear damped second-order hyperbolic partial differen-tial equation (PDE) with affine parameter dependence using a goal-oriented approach by finite element (FE ... [more ▼]

In this paper, we study numerically the linear damped second-order hyperbolic partial differen-tial equation (PDE) with affine parameter dependence using a goal-oriented approach by finite element (FE) and reduced basis (RB) methods. The main contribution of this paper is the “goal-oriented” proper orthogonal decomposition (POD)–Greedy sampling procedure within the RB approximation context. First, we introduce the RB recipe: Galerkin projection onto a space YN spanned by solutions of the governing PDE at N selected points in parameter space. This set of N parameter points is constructed by the standard POD–Greedy sampling procedure already developed. Second, based on the affine parameter dependence, we make use of the offline-online computational procedures: in the offline stage, we generate the RB space; in the online stage, given a new parameter value, we calculate rapidly and accurately the space-time RB output of interest and its associated asymptotic error. The proposed goal-oriented POD–Greedy sampling procedure can now be implemented and will look for the parameter points such that it minimizes this (asymptotic) output error rather than the solution error (or, error indicator which is the dual norm of residual) as in the standard POD–Greedy procedure. Numerical results show that the new goal-oriented POD–Greedy sampling procedure improves significantly the accuracy of the space-time output computation in comparison with the standard POD–Greedy one. The method is thus ideally suited for repeated, rapid and reliable evaluation of input-output relationships within the space-time setting. [less ▲]

Detailed reference viewed: 85 (3 UL)
Full Text
See detailSurvey of Petri nets Slicing
Khan, Yasir Imtiaz UL; Guelfi, Nicolas UL

Report (2013)

Petri nets slicing is a technique that aims to improve the verification of systems modeled in Petri nets. Different Petri nets slicing constructions are studied along with algorithms to compute them ... [more ▼]

Petri nets slicing is a technique that aims to improve the verification of systems modeled in Petri nets. Different Petri nets slicing constructions are studied along with algorithms to compute them. Petri nets slicing was first developed to facilitate debugging but then devel- oped for alleviating the state space explosion problem for model checking Petri nets. This article has twofold objectives, the first is to unify all the existing slicing algorithms syntactically by the definition of a standard abstract syntax and rewriting of the studied slicing algorithms using the proposed syntax. The second is to discuss the contribution of each slicing construction and comparing the major differences between them. One of the interesting exploitation of the survey is for the selection and im- provement of slicing techniques for approaches concerned by optimizing verification of state event models. [less ▲]

Detailed reference viewed: 133 (9 UL)
Full Text
See detailOptimizing algebraic petri net model checking by slicing
Khan, Yasir Imtiaz UL

Report (2013)

Detailed reference viewed: 27 (3 UL)
Full Text
See detailThe Node-Based Smoothed Finite Element Method in nonlinear elasticity
Lee, Chang-Kye; Mihai, L. Angela; Bordas, Stéphane UL

Report (2013)

Detailed reference viewed: 81 (3 UL)
Full Text
See detailStudying Boardroom E-Voting Schemes: Usability and Trust
Khader, Dalia UL; McCall, Roderick UL; Lopez Becerra, JOSE MIGUEL UL

Report (2013)

This technical report presents initial results of an ongoing research on Usability and Trust in Boardroom E-voting Systems. OpenVote, an implementation of one of the existing boardroom e-voting schemes ... [more ▼]

This technical report presents initial results of an ongoing research on Usability and Trust in Boardroom E-voting Systems. OpenVote, an implementation of one of the existing boardroom e-voting schemes, is used as our case study. The primary contributions of this report are: ** A usability and trust study of the first version of the OpenVote System. ** The development of a questionnaire relating to usability and trust within boardroom e-voting systems. **An overview of a revised version of OpenVote. [less ▲]

Detailed reference viewed: 245 (41 UL)
Full Text
See detailVisual Modelling of and on Tangible User Interfaces
Tobias, Eric; Kelsen, Pierre UL

Report (2012)

The purpose of this thesis is to investigate the use and benefit of visual modelling languages (VMLs) in modelling on tangible user interfaces (TUIs), and modelling TUI applications. Three main research ... [more ▼]

The purpose of this thesis is to investigate the use and benefit of visual modelling languages (VMLs) in modelling on tangible user interfaces (TUIs), and modelling TUI applications. Three main research questions are asked: - Is it possible and practical to model an application or process using a TUI? - Which General-purpose VML (GPVML) performs best in modelling a VML scenario for use on TUI? - Is it realistic to use a GPVML to model complex TUI applications? To answer the first research question, a Business Process Model and Notation, version 2 (BPMN2), ideation scenario is used with a tangible widget toolkit prototype on a TUI table to evaluate the performance and obtain feedback from test candidates. The study showed that it is possible to model a process using a TUI and the test candidate feedback did not lead to the conclusion that the modelling was cumbersome or impractical. To find a suitable GPVML, the thesis explores and evaluates the current state of the art in VMLs for describing general problems. After gathering different VMLs, the thesis compares three languages using a simple scenario: the visual object constraint language (VOCL), augmented constraint diagrams (ACD), and the visual contract language (VCL). A weighted evaluation based on multiple quality criteria led to the conclusion that VCL is best suited to model TUI applications, answering the second research question. The thesis answers the third research question by using VCL to model a more complex and complete scenario of an ideation process, which is based on using a BPMN2 on a TUI. This is done to assess VCL's suitability to more complex problems and its maturity. The study concludes that VCL is not yet mature enough to enable its general applicability in a wide variety of settings. The three research questions were dressed with a hypothesis in mind: collaborative, novice friendly modelling environments are able to reduce the gap between stakeholders and software engineers during software projects, leading to a reduction of unrealistic expectations and an increase in the availability of domain knowledge. While the hypothesis is too broad to be proven by this thesis, the research questions answered here give some insights into how to approach it. [less ▲]

Detailed reference viewed: 85 (3 UL)
Full Text
See detailThe Simple Shear and Simple Tension Problems in Linear and Nonlinear Elasticity
Lee, Chang-Kye; Bordas, Stéphane UL

Report (2012)

Detailed reference viewed: 106 (9 UL)
Full Text
See detailNews and stock markets: A survey on abnormal returns and prediction models
Minev, Mihail UL; Schommer, Christoph UL; Grammatikos, Theoharry UL

Report (2012)

Vast amount of news articles are published daily reflecting global topics. The stories represent information about events and expert opinions, which may trigger positive or negative expectations on the ... [more ▼]

Vast amount of news articles are published daily reflecting global topics. The stories represent information about events and expert opinions, which may trigger positive or negative expectations on the stock markets. The literature describes various methods for analyzing such correlations. In this paper we consider related approaches for tracking the impact of news on abnormal stock returns. In the first part we introduce studies with back- ground in Finance. Primarily by applying statistical functions the works examine unusual price volatilities and explore possible sources and market conditions, e.g. biased investors, limited attention, macro-economic variables, country development state, et cetera. In the second part we present studies with background in Computer Science, which take advan- tage of historic news and the equivalent market values. By following the common learning paradigm the projects elaborate prototypes for trend and stock price prediction. In the current survey we evaluate leading approaches regarding the objectives, assumptions, in- put, techniques, and performance. Moreover we provide a comparison framework of the recent prototypes and identify gaps for future research. [less ▲]

Detailed reference viewed: 409 (17 UL)
See detailDiversité des jeunes et accès au bien-être (DJAB). Rapport de projet
Berg, Charles UL; Meyer, Jean-Louis; Milmeister, Marianne UL

Report (2012)

L'étude internationale "Health Behaviour in Schoolaged Children (HBSC)" de l'Organisation mondiale de la santé (OMS) a été menée dans les écoles de l'enseignement secondaire (et primaire) luxembourgeois ... [more ▼]

L'étude internationale "Health Behaviour in Schoolaged Children (HBSC)" de l'Organisation mondiale de la santé (OMS) a été menée dans les écoles de l'enseignement secondaire (et primaire) luxembourgeois et un premier rapport en a été publié sous l'intitulé "Das Wohlbefinden der Jugendlichen in Luxemburg". L’échantillon de l’étude comprend uniquement des adolescents scolarisés. Par cette approche, les jeunes en âge scolaire, ne fréquentant pas ou seulement irrégulièrement l’école, sont sous-représentés. Or, afin d’améliorer l’accès au bien-être et à la santé ainsi qu’à l’information y liée, il est important d’identifier les facteurs qui influencent les comportements de santé des jeunes en général et de ceux qui vivent des conditions difficiles en particulier. Par conséquent, il est indispensable d’étudier les jeunes dans la diversité de leurs réalités individuelles, familiales et sociales. Dans un but d’améliorer la représentativité de l’analyse et de faciliter aux professionnels concernés le développement de mesures concrètes de prévention, adaptés aux besoins spécifiques des jeunes, il nous semble important de répliquer l’enquête dans une optique comparative et analytique auprès de groupes de jeunes sous-représentés dans l’étude initiale. Il s’agit notamment de jeunes en situations individuelle, familiale et sociale difficiles et engagés dans des trajectoires vulnérables, comme par exemple des jeunes ayant abandonnés précocement l’école, des toxicomanes ou des jeunes placés dans un centre socio-éducatif. [less ▲]

Detailed reference viewed: 41 (12 UL)
Full Text
See detailBypassing the Combinatorial Explosion: Using Similarity to Generate and Prioritize T-wise Test Suites for Large Software Product Lines
Henard, Christopher UL; Papadakis, Mike UL; Perrouin, Gilles UL et al

Report (2012)

Software Product Lines (SPLs) are families of products whose commonalities and variability can be captured by Feature Models (FMs). T-wise testing aims at finding errors triggered by all interactions ... [more ▼]

Software Product Lines (SPLs) are families of products whose commonalities and variability can be captured by Feature Models (FMs). T-wise testing aims at finding errors triggered by all interactions amongst t features, thus reducing drastically the number of products to test. T-wise testing approaches for SPLs are limited to small values of t -- which miss faulty interactions -- or limited by the size of the FM. Furthermore, they neither prioritize the products to test nor provide means to finely control the generation process. This paper offers (a) a search-based approach capable of generating products for large SPLs, forming a scalable and flexible alternative to current techniques and (b) prioritization algorithms for any set of products. Experiments conducted on 124 FMs (including large FMs such as the Linux kernel) demonstrate the feasibility and the practicality of our approach. [less ▲]

Detailed reference viewed: 80 (5 UL)
Full Text
See detailA Survey on the Performance of Commercial Mobile Access Networks
Frank, Raphaël UL; Forster, Markus UL; Mario, Gerla et al

Report (2012)

Detailed reference viewed: 59 (4 UL)
Full Text
See detailLes retraites au Luxembourg : modélisation et évaluation d'un système diversifié avec répartition et capitalisation
Guigou, Jean-Daniel UL; Lovat, Bruno; Schiltz, Jang UL

Report (2010)

Nous développons un modèle permettant d évaluer l e¢ cacité d un système de pension diversi é - dont le nancement est basé à la fois sur la répartition et la capitalisation - à partir de données propres ... [more ▼]

Nous développons un modèle permettant d évaluer l e¢ cacité d un système de pension diversi é - dont le nancement est basé à la fois sur la répartition et la capitalisation - à partir de données propres au Luxembourg. Le critère d e¢ cacité retenu est celui de la soutenabilité à long terme du système. Nous comparons ainsi la soutenabilité dans le temps d un régime combinant répartition et capitalisation avec celle d un régime reposant uniquement soit sur la répartition, soit sur la capitalisation. Cette étude procède en trois étapes. La première étape consiste à mettre en évidence les courbes d évolution des salaires au Luxembourg. Pour y parvenir, nous avons utilisé une méthode statis- tique récente basée sur les trajectoires de développement. Nous avons estimé les paramètres du modèle à partir d une base de données unique, fournie par l IGSS, comprenant les salaires annualisés de tous les employés du secteur privé luxem- bourgeois. Nous avons ainsi obtenu neuf trajectoires moyennes d évolution des salaires ainsi que le poids de chacune d elles dans la société luxembourgeoise. La deuxième étape propose une évaluation du système d assurance-pension luxembourgeois à partir d un nouveau critère : le coe¢ cient de soutenabilité. Il s agit du nombre d euros que les actifs doivent gagner en moyenne pour assurer chaque euro de retraite avec la législation en vigueur. Nos estimations montrent la forte sensibilité du coe¢ cient de soutenabilité aux variables démographiques, mettant ainsi en évidence le risque qui pèse sur le système par répartition au Luxembourg. La troisième et dernière étape introduit la capitalisation dans l analyse. Concrè- tement, il s agit d une épargne-retraite constituée par annuités constantes et pla- cée à un taux d intérêt aléatoire. Le problème revient alors à déterminer le mon- tant optimal de l annuité pour chacun des neuf groupes d individus déjà identi és et d en déduire les ratios répartition/capitalisation correspondants. Notre critère repose là aussi sur le nombre d euros qu il est nécessaire de gagner pour assurer le nancement de chaque euro de retraite, et de la variabilité de ce nombre, mais en tenant compte cette fois-ci, non seulement de l e¤ort collectif (via la répartition), mais aussi de l e¤ort individuel (via la capitalisation). Le but est alors de contrôler la variabilité de l e¤ort total au sein du nouveau système, sous la contrainte d un gain en soutenabilité par rapport au système initial. Des résultats di¤érents en termes de ratio répartition/capitalisation d une part, et d annuités d autre part, sont obtenus en fonction du gain de soutenabilité que l on se donne a priori. [less ▲]

Detailed reference viewed: 74 (2 UL)
Full Text
See detailLes langues dans les offres d'emploi du Luxemburger Wort 1984-2009
Pigeron, Isabelle UL; Fehlen, Fernand UL

Report (2010)

Cette étude propose une analyse des demandes linguistiques figurant dans les offres d’emploi du Luxemburger Wort sur la période 1984-2009. A partir d’un échantillon de 60 éditions du quotidien national ... [more ▼]

Cette étude propose une analyse des demandes linguistiques figurant dans les offres d’emploi du Luxemburger Wort sur la période 1984-2009. A partir d’un échantillon de 60 éditions du quotidien national, l’étude passe en revue l’évolution des demandes linguistiques, mais aussi des compétences exigées ou souhaitées, et souligne les différences entre les branches d’activité. [less ▲]

Detailed reference viewed: 52 (12 UL)
Full Text
See detailEvaluation des Schulversuchs : Jean-Jaurès-Ganztagsschule
Joachim, Patrice UL

Report (2009)

Detailed reference viewed: 11 (2 UL)
See detailNeeds analysis report for Luxembourg in the frame of the EUCIM-TE-project
Berg, Charles UL; Joachim, Patrice UL; Kneip, Nico et al

Report (2009)

Detailed reference viewed: 23 (1 UL)