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See detailEnhancing Project Robustness: A Risk Management Perspective
Gericke, Kilian UL

Doctoral thesis (2011)

Product development projects are challenging management tasks. The complexity and dynamics of requirements and goals, the novelty of design tasks, and polytely (striving for multiple goals) can all affect ... [more ▼]

Product development projects are challenging management tasks. The complexity and dynamics of requirements and goals, the novelty of design tasks, and polytely (striving for multiple goals) can all affect the course of a project. Frequent consequences of these boundary conditions are unwanted events which inhibit a successful project. This work shall provide a better understanding of project robustness, its barriers and enablers. To achieve this goal, the work was conducted following a research approach based on the Design Research Methodology proposed by Blessing and Chakrabarti. The work is based on a comprehensive literature study which resulted in a model describing the causality of project failures. The underlying assumption of the project failure causality model, that companies which treat risks preventively and proactively are more likely to successfully finish their product development projects than other companies, is examined by an analysis of data from 141 small and medium sized enterprises (SMEs). Design methodologies, project management, risk management and maturity models such as the Capability Maturity Model Integration (CMMI) are proposed in order to support product development. The study validates the importance of the use of these systematic approaches to support product development projects, but none of the considered approaches on its own will secure project success. This suggests that the expected benefit (a robust project) can only be achieved using different approaches conjointly. While design methodologies and project management offer a rich support for development activities, risk management supports the project specific selection of appropriate risk treatment measures. A result of this work is a support for the pre-selection of risk treatment strategies based on the project failure causality model and its link to the proposed categorisation of risk treatment strategies. In this dissertation it is shown that the proposed categorisation of risk treatment strategies, the categorisation of the risk impact evolvement, and the question based support were easily understood by industrial experts. Their feedback validates the applicability and acceptance of the question based support as helpful for risk treatment strategy pre-selection, but also lead to a revision of the proposed support. The result is a matrix based support, intended to contribute to an enhancement of project robustness by supporting the process of risk treatment strategy selection which is currently only insufficiently supported. The matrix based support considers, in addition to traditional risk characteristics (likelihood of occurrence and severity of impact) the time-dependent evolvement of risk impacts. [less ▲]

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See detailCryptanalysis and design of symmetric primitives
Nicolic, Ivica UL

Doctoral thesis (2011)

Cryptographic primitives are the basic building blocks of various cryptographic systems and protocols. Their application is based on their well established properties. The security of a crypto system is ... [more ▼]

Cryptographic primitives are the basic building blocks of various cryptographic systems and protocols. Their application is based on their well established properties. The security of a crypto system is proven under the assumption that the underlying cryptographic primitives provide some specific security levels. Therefore it is critical to use primitives that can meet these requirements. However, there is no general approach of constructing fast and provably secure primitives. Rather, the primitives undergo years of thorough cryptanalysis and only after no attacks have been found, they can be considered for real world applications. This PhD thesis deals with the two main cryptographic primitives: block ciphers and cryptographic hash functions. The main contribution lies in presenting attacks on these algorithms. The analysis ranges from finding ad-hoc differential trails that are used for collision search and distinguishers on specific hash functions to automatic search tools that give the optimal differential trails for block ciphers. Weaknesses are shown for a number of SHA-3 candidates in the framework of rotational distinguishers and meet in-the-middle based preimage attacks. [less ▲]

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See detailEssays on corporate default process: UK and France
Nigam, Nirjhar UL

Doctoral thesis (2011)

The thesis has been conducted upon a unique and primary database manually collected through courts and various reliable sources (governmental and non-governmental offices). This is the major strength of ... [more ▼]

The thesis has been conducted upon a unique and primary database manually collected through courts and various reliable sources (governmental and non-governmental offices). This is the major strength of this thesis. With such a database, we built individual statistics on the corporate bankruptcies process in for two major European countries (France and United Kingdom). The collected data deals with the causes of financial default, the recovery rates of creditors, the process of decision making at the time of default, the efficiency of such decisions, etc. Such research project helps in distinguishing the origins of corporate financial default: are they independent from the national bankruptcy code or not? In order to test the effect of legal environment, we computed the most comprehensive legal indexes till date. Our legal indexes consist of more than 300 questions that explain the particular function of bankruptcy. We merge these indexes with the hand collected database for France and UK. This makes this thesis really unique as it is composed of original hand collected databases. To the best of our knowledge the UK database has no equivalence as for the first time we manage to include liquidations which constitute more than 85% of bankruptcies in UK. Even the scholars in UK lack such information. Such empirical work is completed by a microeconomic theoretical analysis and would yield interesting results that will be discussed in detail in the rest of the chapters of the thesis and also open avenues for future research work. Chapter 1 presents a brief introduction to the topic, explaining the research aims and research methodology. Chapter 2 presents the detailed survey of literature on bankruptcy. It starts by explaining the basic concept associated with bankruptcy, need of bankruptcy laws, the main objective of bankruptcy, the main processes associated with bankruptcy, classification of bankruptcy regimes and the law and finance approach to understand legal environment affecting bankruptcy. It explores the previous literature and findings and provides our contribution to the pre-existing literature and justifies our research goals and our approach. Chapter 3 empirically investigates the choice between informal and formal (court-supervised) restructuring of small and medium French firms in default. The procedure is depicted as a sequential game in which stakeholders first decide whether or not to engage in an informal negotiation. Then, conditional on opting for an informal workout, the creditors and the debtor can succeed or fail in reaching an agreement in order to restructure the firm’s capital structure. Based on a sample of 735 credit lines allocated to 386 French distressed firms, we test different hypotheses which captures i) coordination vs. bargaining power issues, ii) informational problems, iii) firms’ characteristics, and iv) loan characteristics. Using a sequential LOGIT approach, we first find that the probability for opting for an informal workout i) decreases when the bank is the debtor’s main creditor and ii) increases with the size of the loan. In addition, the likelihood of success of an informal workout i) decreases when the management of a badly rated firm is considered as incompetent, and ii) decreases when the bank is the debtor’s main creditor. The result concerning the bank as being the main creditor suggests that “bargaining power” argument dominates the “coordination” argument. Finally, we find no evidence of the impact of collateral on the decision between informal and formal restructuring. Chapter 4 describes the prevalent bankruptcy procedure of UK and France; in general it provides an entire macro view of the bankruptcy laws in given two countries. It presents the various formal and informal procedures, explains their functioning, how they are triggered and the underlying specificities about each process. It is very crucial to understand the working of each procedure as this forms the basis for the future chapters where we related the result of our summary statistics and econometrics to specificities of these procedure and come up with useful conclusions and insights. In chapter 5 the focus returns to the micro economic analysis. We explore the two unique hand coded databases, collected through different sources. Our database consists of 264 small and medium sized enterprises representing France and 564 small and medium sized enterprises representing UK. These countries represent two major legal systems prevailing in Europe: common law and civil law. Both legislations have features that are of interest for research. Based on are datasets we provide summary statistics on both the countries. Our descriptive statistics explains the average profile of our sample company, it provides us with the reasons that lead the company into bankruptcy, it provides us the detailed asset and liability structures of the firms and the detailed claim structure and recovery structure. In addition it also provides us with the duration of the procedure and the costs involved in the process. We also perform multivariate analysis to test the choice between continuation and liquidation for France and to test the factors that increase or decrease the chances of receivership (procedure made for the benefits of banks) and administration (regarded as reorganization procedure) in UK. The main aim of the chapter 6 is to find the legal characteristics that impact on the recovery rates. Previous studies (LLSV, Doing Business Report, World Bank) have usefully used a set of legal indexes to rank the bankruptcy law prevalent within the country. But they fail to identify the characteristics of bankruptcy procedures that create more recoveries. We give here elements of answer by taking into consideration two countries that are good representatives of the two main legal systems prevailing in Europe: France (Civil Law) and United Kingdom (Common Law). To enable this, we built original legal indexes comprising of 158 binary questions that highlight ten major dimensions of corporate bankruptcy procedures: (1) accessibility, (2) exclusivity, (3) bankruptcy costs, (4) production of information, (5) protection of the debtor’s assets, (6) protection of claims, (7) coordination of creditors, (8) decision power, (9) sanction of faulty management, and (10) inclination towards liquidation / reorganization. We then propose a mapping of procedures that shows a clear specialization between them. The French procedures (“redressement judiciaire” and “liquidation judiciaire”) are more protective of the debtor’s assets and favor more the coordination of secured claims, public claims, and unsecured claims. In UK, we find strong opposition between the procedures oriented to liquidation and the other procedures. [less ▲]

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See detailExpertise und diagnostische Urteilsbildung : ein sozial-kognitiver Ansatz
Böhmer, Matthias UL

Doctoral thesis (2011)

In this thesis experts’ diagnostic judgment formation is seen as a social cognitive process: It is analyzed as a person-related judgment and is investigated according to the social cognition paradigm. The ... [more ▼]

In this thesis experts’ diagnostic judgment formation is seen as a social cognitive process: It is analyzed as a person-related judgment and is investigated according to the social cognition paradigm. The theoretical foundation is provided by dual process models (e.g. continuum model), which assume two different strategies of person-related information processing in order to form a judgment. The heuristic strategy is characterized by a categorization process and the corresponding activation of a specific person category. The information integrating strategy focuses on individual characterization of a person and the corresponding collection and integration of individual person attributes. A judge’s expertise is acknowledged to have an essential influence on the process of judgment formation. Experts, in contrast to laymen, are able to switch between the two strategies. The degree to which diagnostic judgment formation can be described by means of dual process models is investigated in a series of four quasi-experiments including psychotherapists and teachers as experts and students and staff members of Saarland University as laymen. Thus, social judgment formation is compared in two different domains. Two experiments focus on judgment itself by measuring judgmental data. The two other experiments focus on attention allocation and person memory by measuring self-paced reading time and free recall. Results show the expected pattern in both professional domains. Both psychotherapists and teachers are able to switch between the two strategies. So experts’ diagnostic judgment formation can be described by means of dual process models. [less ▲]

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See detailBeing a newcomer in a multilingual school : a case study
Gómez Fernández, Roberto UL

Doctoral thesis (2011)

The present thesis aims at understanding the process of becoming a member in a diverse and multilingual primary school in Luxembourg. It is a case study about one child belonging to one of the ethnic and ... [more ▼]

The present thesis aims at understanding the process of becoming a member in a diverse and multilingual primary school in Luxembourg. It is a case study about one child belonging to one of the ethnic and linguistic communities most affected by school failure. ‘Romanophones’ or romance-language speaking students in Luxembourg are touched by low achievement rates of school success. Also newcomers find themselves in challenging situations and are also affected by this problem. By following this child during one academic year an epistemological conflict between ‘agentivity’ and ‘structure’ is proposed. The seven-year old child, Nuno, had to follow lessons in German and Luxembourgish when he had no knowledge of these languages at all at his arrival in November from another primary school in Brazil. A close look at his interactions and identity processes with his peers and teachers revealed a re-evaluation of Nuno’s capital and resources which affected his academic progress as well as his identity during the year. This re-evaluation resulted in a “decapitalization” (Martín Rojo, 2008; 2010) of some of Nuno’s pre-existing resources (e.g., Portuguese language), which could otherwise be used as a positive resource in his progression towards “full membership”, and the eventual formation of a “community of practice”. Nuno’s initial agentivity resisted categorizations and also what could be classified as gatekeeping practices towards him. Along the academic year some major changes took place (a change of teacher and teaching philosophies, the arrival of another Brazilian newcomer) which affected Nuno’s behaviour, learning and identity. The interview data and the audio-visual recordings provide insights into the difficulties a ‘romanophone’ newcomer must confront as well as the fact that a community of practice is in constant construction. [less ▲]

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See detailL’accès du public aux documents des institutions européennes: le développement d’un droit et sa mise en application (1973-2004)
Bagias, Andreas UL

Doctoral thesis (2011)

Access to official documents is a key outcome of the concept of transparency as applied to the institutions of the European Union. In the 1990s, transparency offered the promise of a cure to the ... [more ▼]

Access to official documents is a key outcome of the concept of transparency as applied to the institutions of the European Union. In the 1990s, transparency offered the promise of a cure to the “democratic deficit” from which these European institutions suffered. Key factors that underpinned progress towards greater transparency and the right of access to documents are identified as: the influence of globalization and the gradual adoption of national legislations of the various member states, the “Citizens Europe” movement, the legal evolution concerning access to environmental information, the institutional evolution of the European decision-making process, the difficulties encountered during the ratification of the Maastricht Treaty and, the accession of Sweden and Finland in 1995 to the European Union. These developments culminated with the insertion of article 255 to the Amsterdam Treaty and, under the 2001 presidency of Sweden, the adoption of Regulation (EC) No 1049/2001. Official statistics reveal, however, that the right of access to documents, produced and received by the European institutions, is rarely applied by European citizens. This right, like a working knowledge of the functioning of the European Union, remains the preserve of a small circle of professionals, usually established in Brussels. It seems that transparency and the right of access to documents does not bring the citizen closer to the European institutions and it does not solve the stated “democratic deficit”. Rather, this research finds that it has been used as an instrument in an institutional struggle to limit the power of the Council and the Commission. [less ▲]

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See detailGenetic Algorithm based roadmapping: A method for product innovation
Suzianti, Amalia UL

Doctoral thesis (2011)

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See detailElectronic structure and optical properties of III-N nanowires
Molina-Sanchez, Alejandro UL

Doctoral thesis (2011)

The term III-N nanowire (NW) will refer throughout this work to the free-standing nanowires made of group-III-nitrides semiconductors, namely InN, GaN and AlN. These nanostructures have a large length ... [more ▼]

The term III-N nanowire (NW) will refer throughout this work to the free-standing nanowires made of group-III-nitrides semiconductors, namely InN, GaN and AlN. These nanostructures have a large length/diameter ratio, of the order of 100 (sev- eral micrometers versus tenths of nanometers). The term free-standing highlights the fact that the NWs are not embedded in another material. The improvement of the epitaxial techniques, and in particular, those based on III-N semiconductors, has lead an important part of the Solid State Physics community to concentrate the attention in the last years towards a better understanding of the physical properties of those NWs. Nanowires present several di erences with respect to the still widely investi- gated two-dimensional layers and the zero-dimensional nanostructures (quantum dots). We would like to highlight the following: (i) Nanowires grow strain-free (except maybe at their base), and thus with a minimal presence of dislocations or defects along the main structure. This fact opens the possibility of growing high- quality materials with an important lattice mismatch with the substrate, contrary to the situation found in quantum dots or superlattices. (ii) Depending on the NW lateral dimensions, two types of NWs can be distinguished. When the diameter is larger than 20 nm, the electronic properties of the NWs can be considered as that of a bulk material, thus making them a suitable platform to study the bulk optical and transport properties, which can be hardly investigated in bulk samples (thin lms), that grow with a high density of defects, when there is a high lattice mismatch with the substrate. (iii) For NWs of smaller diameters (. 20 nm), on the other hand, the e ects of quantum con nement can lead to important changes in the optical and transport properties, which can open the possibility of tuning the NW properties by controlling their size. One can roughly classify the investigations on nanowires into three main re- search lines. The rst one concerns the fabrication, being the molecular beam epitaxy or/and the metal organic chemical vapor deposition (MOCVD) the two techniques that allow the growth of higher quality NWs. This research area is in 2 constant development, and is not limited only to the growth of pure compound NWs, but also alloy-based NWs, which extend the possibilities of allowing beyond those possible in standard bulk growth, or axially and radially structured NWs. New physical phenomena arise which must be tacked by the physical community, in particular the e ect of the surface in the optical and transport properties of the NWs. Another focus of research is based on applications to optoelectronics devices and photovoltaic cells. In particular, III-N NWs, as InN, GaN and AlN, have attracted a special interest of the scienti c community, due to the band gap engineering. InN has a band gap of 0.67 eV (1852 nm), in the infrared, whereas GaN and AlN have a band gap of 3.5 eV (355 nm) and 6.2 eV (200 nm), respec- tively, in the ultraviolet. This opens the possibility of covering the whole solar spectrum by an appropriate alloying. In this context, the theory and numerical simulations play a crucial role in the explanation of NWs properties and a better understanding of the observed phenomena. The predictions o ered by the theory can also drive the fabrication of new heterostructures and the design of devices. In this work, we have studied theoretically by using several models, the fundamental aspects of the electronic structure and optical properties of the III-N bulk semiconductors in the rst place, and have applied afterwards such models to the investigation of the III-N nanowires physical properties. [less ▲]

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See detailThe (Mis-)Measure of Children’s Cognitive Abilities.
Baudson, Tanja Gabriele UL

Doctoral thesis (2011)

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See detailBeing a Newcomer in a Multilingual School: A Case Study
Gomez-Fernandez, Roberto UL

Doctoral thesis (2011)

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See detailReservoir Computing Architectures for Modeling Robot Navigation Systems
Antonelo, Eric Aislan UL

Doctoral thesis (2011)

This thesis proposes a new efficient and biologically inspired way of modeling navigation tasks for autonomous mobile robots having restrictions on cost, energy consumption, and computational complexity ... [more ▼]

This thesis proposes a new efficient and biologically inspired way of modeling navigation tasks for autonomous mobile robots having restrictions on cost, energy consumption, and computational complexity (such as household and assistant robots). It is based on the recently proposed Reservoir Computing approach for training Recurrent Neural Networks. Robot Navigation Systems Autonomous mobile robots must be able to safely and purposefully navigate in complex dynamic environments, preferentially considering a restricted amount of computational power as well as limited energy consumption. In order to turn these robots into commercially viable domestic products with intelligent, abstract computational capabilities, it is also necessary to use inexpensive sensory apparatus such as a few infra-red distance sensors of limited accuracy. Current state-of-the-art methods for robot localization and navigation require fully equipped robotic platforms usually possessing expensive laser scanners for environment mapping, a considerable amount of computational power, and extensive explicit modeling of the environment and of the task. This thesis The research presented in this thesis is a step towards creating intelligent autonomous mobile robots with abstract reasoning capabilities using a limited number of very simple raw noisy sensory signals, such as distance sensors. The basic assumption is that the low-dimensional sensory signal can be projected into a high-dimensional dynamic space where learning and computation is performed by linear methods (such as linear regression), overcoming sensor aliasing problems commonly found in robot navigation tasks. This form of computation is known in the literature as Reservoir Computing (RC), and the Echo State Network is a particular RC model used in this work and characterized by having the high-dimensional space implemented by a discrete analog recurrent neural network with fading memory properties. This thesis proposes a number of Reservoir Computing architectures which can be used in a variety of autonomous navigation tasks, by modeling implicit abstract representations of an environment as well as navigation behaviors which can be sequentially executed in the physical environment or simulated as a plan in deliberative goal-directed tasks. Navigation attractors A navigation attractor is a reactive robot behavior defined by a temporal pattern of sensory-motor coupling through the environment space. Under this scheme, a robot tends to follow a trajectory with attractor-like characteristics in space. These navigation attractors are characterized by being robust to noise and unpredictable events and by having inherent collision avoidance skills. In this work, it is shown that an RC network can model not only one behavior, but multiple navigation behaviors by shifting the operating point of the dynamical reservoir system into different \emph{sub-space attractors} using additional external inputs representing the selected behavior. The sub-space attractors emerge from the coupling existing between the RC network, which controls the autonomous robot, and the environment. All this is achieved under an imitation learning framework which trains the RC network using examples of navigation behaviors generated by a supervisor controller or a human. Implicit spatial representations From the stream of sensory input given by distance sensors, it is possible to construct implicit spatial representations of an environment by using Reservoir Computing networks. These networks are trained in a supervised way to predict locations at different levels of abstraction, from continuous-valued robot's pose in the global coordinate's frame, to more abstract locations such as small delimited areas and rooms of a robot environment. The high-dimensional reservoir projects the sensory input into a dynamic system space, whose characteristic fading memory disambiguates the sensory space, solving the sensor aliasing problems where multiple different locations generate similar sensory readings from the robot's perspective. Hierarchical networks for goal-directed navigation It is possible to model navigation attractors and implicit spatial representations with the same type of RC network. By constructing an hierarchical RC architecture which combines the aforementioned modeling skills in two different reservoir modules operating at different timescales, it is possible to achieve complex context-dependent sensory-motor coupling in unknown environments. The general idea is that the network trained to predict the location and orientation of the robot in this architecture can be used to select appropriate navigation attractors according to the current context, by shifting the operating point of the navigation reservoir to a sub-space attractor. As the robot navigates from one room to the next, a corresponding context switch selects a new reactive navigation behavior. This continuous sequence of context switches and reactive behaviors, when combined with an external input indicating the destination room, leads ultimately to a goal-directed navigation system, purely trained in a supervised way with examples of sensory-motor coupling. Generative modeling of environment-robot dynamics RC networks trained to predict the position of the robot from the sensory signals learns forward models of the robot. By using a generative RC network which predicts not only locations but also sensory nodes, it is possible to use the network in the opposite direction for predicting local environmental sensory perceptions from the robot position as input, thus learning an inverse model. The implicit map learned by forward models can be made explicit, by running the RC network in reverse: predict the local sensory signals given the location of the robot as input (inverse model). which are fed back to the reservoir, it is possible to internally predict future scenarios and behaviors without actually experiencing them in the current environment (a process analogous to dreaming), constituting a planning-like capability which opens new possibilities for deliberative navigation systems. Unsupervised learning of spatial representations In order to achieve a higher degree of autonomy in the learning process of RC-based navigation systems which use implicit learned models of the environment for goal-directed navigation, a new architecture is proposed. Instead of using linear regression, an unsupervised learning method which extracts slowly-varying output signals from the reservoir states, called Slow Feature Analysis, is used to generate self-organized spatial representations at the output layer, without the requirement of labeling training data with the desired locations. It is shown experimentally that the proposed RC-SFA architecture is empowered with an unique combination of short-term memory and non-linear transformations which overcomes the hidden state problem present in robot navigation tasks. In addition, experiments with simulated and real robots indicate that spatial activations generated by the trained network show similarities to the activations of CA1 hippocampal cells of rats (a specific group of neurons in the hippocampus). [less ▲]

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See detailRobust topology management in DT-MANETs: An efficient tree-based decentralized and multi-objective approach
Piyatumrong, Apivadee UL

Doctoral thesis (2010)

Delay-tolerant mobile ad hoc network (DT-MANETs) feature frequent and long duration partitioned MANETs. It is a challenged environment where end-to-end connectivity cannot always be obtained. Furthermore ... [more ▼]

Delay-tolerant mobile ad hoc network (DT-MANETs) feature frequent and long duration partitioned MANETs. It is a challenged environment where end-to-end connectivity cannot always be obtained. Furthermore, communication in such network is heavily relying on collaboration between nodes since there is no central authority. Limited resources of communication nodes present another facet of problems in such network. Moreover, the communication is typically done using wireless technologies which are sharing among communication nodes. In order to provide a better quality of service in such environment, topology management technique is used to help controlling network topology. The aim is to manage network resource and to enhance efficiency of communication. In this work, we proposed to do it by constructing an efficient and robust tree-based topology. We model the environment using dynamic and partitioned graph. Under such circumstances, protocols must withstand topology and condition changing. In summary, doing topology management in DT-MANETs encounters the following issues: cooperation among nodes, limitation of resources of mobile node, sharing medium, dynamic and partitioned topology and unrealistic and unscalable approach of centralized algorithm in such environment. This study focuses on managing tree-based topology in DT-MANETs. A set of active links is managed such that the deterioration of network is avoid and the quality of service in DT-MANETs is enhanced. Efficiency and robustness metrics are proposed accordingly. This work proposed to use different quality criteria based on communication node and edge for the selection topology. Both single- and multi-objectives tree-based topology are studied. Algorithms for managing tree-based topology are proposed according to different objectives. All proposed algorithms are purely decentralized, asynchronous algorithm and use one-hop information. [less ▲]

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See detailModalités du développement professionnel d'enseignants du préscolaire et du primaire, dans le domaine du plurilinguisme: conception et évaluation d'une formation continue dans un pays plurilingue (Luxembourg)
Elcheroth, Sylvie UL

Doctoral thesis (2010)

This action-research consists in designing, implementing and evaluating the continuous teacher education programme ‘Ecole multilingue’. The programme is aimed at preschool and primary school teachers and ... [more ▼]

This action-research consists in designing, implementing and evaluating the continuous teacher education programme ‘Ecole multilingue’. The programme is aimed at preschool and primary school teachers and concerns the pedagogy of multilingualism. During the programme, video excerpts showing language learning practices at school were studied, multilingual projects were designed and implemented in the classes of the participants and discussions and exchanges took place within ten monthly meetings. The research questions are the following: What is the professional development that is realised throughout the programme? What are the characteristics of the programme that have afforded this development? The research positions itself within the framework of socio-constructivist and socio-cultural theories. The chosen methodology draws upon thematic analysis, grounded theory, analysis of interactions and analysis of practice. It implies the collection of different types of data: questionnaire, videotapes and transcriptions of the training meetings, logbook of the trainer-researcher, videotapes and descriptions of innovative practices. During the research process, description and analysis grids are used and designed, and research results are cut across. A reflexion about the double role of a trainer and a researcher is developed. The analysis reveals the representations about language learning, multilingual practices and institutional context, as well as the ways of analysing pupils’ learning processes, co-constructed by the participants. It characterises the innovative multilingual practices that the participants have developed in their classes, and it shows the process of accompanying-challenging by the trainer. It furthermore brings out the ways in which the different elements of the programme have contributed to the teachers’ development. It finally may inform a prospective, improved training programme. [less ▲]

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See detailCUBA: Artificial conviviality and user-behaviour analysis in web-feeds
Kaufmann, Sascha UL

Doctoral thesis (2010)

Conviviality is a concept of great depth that plays an important role in any social interaction. A convivial relation between individuals is one that allows the participating individuals to behave and ... [more ▼]

Conviviality is a concept of great depth that plays an important role in any social interaction. A convivial relation between individuals is one that allows the participating individuals to behave and interact with each other following a set of conventions that are shared, commonly agreed upon, or at least understood. This presupposes an implicit or an explicit regulation mechanism based on consensus or social contracts and applies to the behaviours and interactions of participating individuals. With respect to an intelligent web-based system, an applicable social contribution is the give of assistance to other users in situations that are unclear and in guiding him to find the right decision whenever a conflict arises. Such a convivial social biotope deeply depends on both implicit and explicit co-operation and collaboration of natural users inside a community. Here, the individual conviviality may benefit from “The Wisdom of Crowds”, which fosters a dynamic understanding of the user’s behaviour and a strong influence of an individual’s well being to another person(s). The web-based system CUBA focus on such a behavioural analysis through profiling and demonstrates a convivial stay within a web-based feed system. [less ▲]

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See detailDT4BP: a Business Process Modelling Language for Dependable Time-Constrained Business Processes
Capozucca, Alfredo UL

Doctoral thesis (2010)

Today, numerous organisations rely on information software systems to run their businesses. The effectiveness of the information software system then, depends largely on the degree to which the ... [more ▼]

Today, numerous organisations rely on information software systems to run their businesses. The effectiveness of the information software system then, depends largely on the degree to which the organisation's business is accurately captured in the business model. The business model is an abstract description of the way an organisation's functions. Thus, the more precise the business model, the more accurate the requirement definition of the information software system to be engineered.There are an abundance of tools and notations available today to support the development of many types of business process. Many of these artifacts rely on the concept of a business process to describe a business model. A business process is commonly known as a set of one or more linked procedures or activities which collectively realise a business objective or policy goal, normally within the context of an organisational structure defining functional roles and relationships". This thesis is concerned with modelling business processes as a means to accurately capture an organisation's activities and thus, the requirements of the software system that supports these activities.Among the infinite set of possible business processes, this thesis targets only those characterized by the qualities of dependability, collaboration and time. Business processes having these specific dimensions are referred to as Dependable, Collaborative and Time-Constrained (DCTC) business processes. A dependable business process is one whose failures or the number of occurrences in which business process misses its goal are not unacceptably frequent or severe (from certain viewpoint). A collaborative business process is one that requires the interaction of multiple participants to attain its goal. A time-constrained business process is one that owns at least one property expressed in terms of an upper or lower time bound. This thesis investigates how DCTC business processes can be described such that the resulting model captures all the relevant aspects of each dimension of interest. In addition, the business model must be comprehensible to the stakeholders involved not only in its definition, but also in its further use throughout the software development life cycle.A revision and analysis of notations that exist for modelling business processes conducted in this thesis have revealed that today there does not exist any modelling language that provides comprehensible, suitable and sufficiently expressive support for the characteristics of dependability, collaboration and time in an integrated manner. Hence, a significant part of this thesis is devoted to the definition of a new business process modelling language named DT4BP. The aim of this new modelling language is to be comprehensible, suitable and expressive enough to describe DCTC business processes. The definition of this new modelling language implies that a concrete syntax, an abstract syntax, a semantic domain and a semantic mapping is provided. The definition of this new modelling language is given following the Model-Driven Engineering (MDE) approach, and in particular the metamodelling principles. Thus, meta-models and model transformations are used to precisely specify the abstract syntax and semantic mapping elements of the language definition, respectively. Since DT4BP is a textual modelling language, its concrete syntax is specified by a context-free grammar. The Coordinated Atomic Actions conceptual framework with real-time extensions (Timed-CaaFWrk) is used as the semantic domain as it covers a large part of the abstractions included in dependable collaborative time-constrained business processes. The formalisation of this semantic domain according to the metamodelling principles is also part of the material presented in this thesis. Since the business model is considered as a representation of the requirement document the software system to be developed, it is crucial to validate whether it captures the requirements as intended by the stakeholder before going further in the software development process. Hence, besides the comprehensibility, suitability and expressiveness of the modelling language with respect to the domain of interest, it is of special interest to provide a mechanism that allows modellers to ensure that the business model is correct with respect to the stakeholder's expectations. One way of achieving this goal is to provide the modelling language with an executable semantics. In this manner, any business model can be executed on sample input data, and its dynamic behaviour observed. The observation of the dynamic behaviour of the model may be considered as a simulation of the model based on the sample input data. By performing several simulations of the model, the modeller, in cooperation with the stakeholder, can judge whether the business model is correct. This thesis provides an executable semantics for Timed-CaaFWrk that, used in combination with the model transformation that defines the semantic mapping element of the language definition, allows DT4BP models to be validated by simulation. In this manner, the dynamic behaviour of a particular DT4BP model for a given sample input data can be observed by transforming it into a Timed-CaaFWrk model, which is then run thanks to the given executable semantics. [less ▲]

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See detailAdaptation cognitive et vieillissement : entre automatisme et flexibilité
Tournier, Isabelle UL

Doctoral thesis (2010)

L'objectif général de cette thèse est d'étudier l'évolution au cours du vieillissement des processus automatiques et contrôlés, nécessaires à une bonne adaptation cognitive quotidienne. Nous nous ... [more ▼]

L'objectif général de cette thèse est d'étudier l'évolution au cours du vieillissement des processus automatiques et contrôlés, nécessaires à une bonne adaptation cognitive quotidienne. Nous nous intéressons à l'influence de différentes variables cognitives (mémoire de travail, vitesse de traitement et vocabulaire) ainsi qu'aux préférences de routinisation sur l'expression de ce possible effet de l'âge. Des épreuves de fluidités sémantiques simples (Expérience 1) et alternées (Expériences 2 et 3) et des formats simples (Expériences 5a et 6a) et alternés (Expériences 5b et 6b) de la tâche de Hayling ont été réalisés par des adultes jeunes (18-30 ans), âgés (60-74 ans) et très âgés (75 ans et plus). Ces épreuves nous permettent d'étudier le processus automatique à travers la diffusion de l'activation en mémoire sémantique et les processus contrôlés par le biais de l'inhibition et de la flexibilité. L'activité cérébrale associée à l'exécution de fluidités simples et alternées est étudiée chez des participants âgés à l'aide de l'imagerie optique (Expérience 4). Les résultats obtenus sont en faveur d'une réduction avec l'âge de l'efficience des processus contrôlés alors que celle des processus automatiques semble conservée. Des phénomènes de compensation se mettraient en place au cours du vieillissement, s'appuyant sur les processus automatiques et les connaissances accumulées. [less ▲]

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See detailFunctions of hepatitis C virus non-structural protein 2
Dentzer, Thomas UL

Doctoral thesis (2010)

An estimated 170 million people are infected with hepatitis C virus (HCV). 15-30% of HCV-induced chronic hepatitis progresses to cirrhosis within years to decades after infection, and 3-4% of them will ... [more ▼]

An estimated 170 million people are infected with hepatitis C virus (HCV). 15-30% of HCV-induced chronic hepatitis progresses to cirrhosis within years to decades after infection, and 3-4% of them will develop hepatocellular carcinoma. There is no vaccine available, and current HCV therapy of pegylated interferon-! in combination with ribavirin leads to a sustained response only in about 50% of infected patients. The HCV non-structural protein NS2 (MW 23 kDa) is a dimeric multifunctional hydrophobic protein with an essential but poorly understood role in infectious virus production. The N terminal region of NS2 interacts with membranes whereas the Cterminal region, together with the N-terminal third of NS3, forms the NS2-3 protease. NS2 is not required for RNA synthesis, although cleavage at the NS2/3 junction is necessary for replication. Further, NS2 has been shown to interact with a number of viral and host proteins; it has been reported to activate transcription factors, inhibit apoptosis, and is a substrate for host kinase phosphorylation and proteosomic degradation. NS2 determinants and their respective function in the HCV life cycle were investigated. Based on the crystal structure of the post-cleavage form of the NS2 protease domain, we mutated conserved features and analyzed the effects of these changes on polyprotein processing, replication, and infectious virus production. We found that mutations around the protease active site inhibit viral RNA replication by preventing NS2/3 cleavage. Supplementary assays indicated a dimerization defect for these mutant constructs, which prevented cleavage and RNA replication. In contrast, alterations in the dimer interface and at the C-terminal region did not affect replication, NS2 stability, or NS2 protease activity, but decreased infectious virus production. Analysis of the NS2/3 cleavage site revealed an additional function for several residues besides cleavage, notably in infectious virus production. A more comprehensive deletion and mutagenesis analysis of the C-terminal end of NS2 revealed the importance of its C-terminal residue in infectious particle production. Structural data suggests that the C-terminal leucine is locked in the active site, and mutation or deletion of this residue could therefore alter the NS2 folding and disrupt potential protein-protein interactions important for infectious particle production. Further, we established an NS2- 3 interaction model based on the solved NS2pro and NS3 crystal structures and assessed the importance of proximal residues for viral propagation. We were able to show genetic interactions between the viral proteins NS2 and E1 as well as NS2 and NS3. Additionally a pull down assay of strep-tagged NS2 followed by a mass spectrometry analysis divulged the physical interactions between NS2-E2, and NS2- NS3. Numerous host cell proteins could be identified to interact with NS2, involved in various pathways such as membrane trafficking, actin/myosin interactions or actin polymerization. In this study we dissected the residues of NS2 involved in its multiple essential roles and interactions in the HCV life cycle and established NS2 as a new viable target for HCV-specific inhibitors for future anti-viral therapeutics. [less ▲]

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See detailCondition assessment of concrete structures and bridges using vibration monitoring in comparison to changes in their static properties
Bungard, Volker UL

Doctoral thesis (2010)

The thesis deals with the non-destructive condition assessment of civil engineering structures made of reinforced and prestressed concrete as well as bridges and concentrates on a comparison of static and ... [more ▼]

The thesis deals with the non-destructive condition assessment of civil engineering structures made of reinforced and prestressed concrete as well as bridges and concentrates on a comparison of static and dynamic investigation methods. The main questions discuss the sensitivity of changes in static as well as in dynamic properties during the mechanical lifetime of those types of structures under laboratory conditions, the sensitivity of these changes when testing in-situ and the dimension of undesired environmental influences on the dynamic properties. Therefore, a gradually loaded laboratory reinforced concrete beam (cp. chapter 7) and a reinforced as well as a prestressed concrete slab (cp. chapter 8) are investigated for changes in their static and dynamic parameters until reaching their ultimate loads. Furthermore, a successively damaged and stepwise loaded laboratory reinforced concrete slab and a prestressed concrete slab (cp. also chapter 8) are under investigation and also compared in changes in their static as well as in dynamic properties during their lifetimes. By means of static and dynamic tests on a successively damaged and stepwise loaded prestressed concrete bridge (cp. chapter 9) it was possible to investigate the amount of changes in static and dynamic properties for a real in-situ object. A long-term measurement of a composite bridge (cp. chapter 10) demonstrates the environmental influences on the static and dynamic properties of a system which have to be considered when conducting comparative non-destructive condition assessment techniques on real objects. All tests are calculated respectively simulated by the method of the integration of stress (cp. chapter 6) or the finite element method by using the softwares ANSYS and SOFISTIK. Furthermore, measured eigenfrequencies and modeshapes are used to adapt finite element models with the aim to improve the model or to locate and quantify damaged areas. The work is a contribution to the application of non-destructive static and dynamic condition assessment methods on civil engineering structures made of concrete in the sector of civil engineering. [less ▲]

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See detailConception, synthèse et évaluation biologique de dérivés coumariniques en tant qu'agents anticancéreux potentiels
Hemmer, Marc UL

Doctoral thesis (2010)

IK9 was recently reported to be a potent inhibitor of cancer cell invasion and angiogenesis. It markedly reduced in vitro invasion of human HT1080 fibrosarcoma cells through collagen-coated porous ... [more ▼]

IK9 was recently reported to be a potent inhibitor of cancer cell invasion and angiogenesis. It markedly reduced in vitro invasion of human HT1080 fibrosarcoma cells through collagen-coated porous membranes (Boyden chamber assay) and in vivo tumour growth in athymic nude mice. It was furthermore able to decrease angiogenesis ex vivo in a rat aortic ring assay and in vivo in a choroidal neovascularisation mice model. It nevertheless presents some water solubility and stability problems, which should be taken into account for further investigations. In the first part of the project, we synthesized original IK9 derivatives, modulated at the 3- and 6-positions, by introducing functional groups able to improve water solubility and metabolic stability. Their in vitro anti-invasive potency was screened and the generated results highlighted some structure-activity relationships. A second part of the project was devoted to the elucidation of the actually unknown mechanism of action of IK9. Anti-invasive or anti-proliferative effects against endothelial cells, main actors of the angiogenic process, were not emphasised. We showed that IK9 acts likely not as an inhibitor of receptor tyrosine kinases (EGFR, PDGFR and VEGFR). The compound generates a weak decrease of mRNA coding for MMP 2 and 9, and on the other hand a substantial diminution of MMP 2 and 9 secretions by HT1080 fibrosarcoma cells. In conclusion, the consideration of anti-invasive properties together with the worked out solubility and stability profiles highlights several series, notably 6-hydroxycoumarins, 6-hydroxymethylcoumarins and coumarin-3-sulfonamides, whose interest as potential successors to IK9 is undeniable. [less ▲]

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See detailMethods for Extracting Meta-Information from bibliographic databases
Biryukov, Maria UL

Doctoral thesis (2010)

Due to intensive growth of the electronically available publications, bibliographic databases have become widespread. They cover a large variety of knowledge fields and provide a fast access to the wide ... [more ▼]

Due to intensive growth of the electronically available publications, bibliographic databases have become widespread. They cover a large variety of knowledge fields and provide a fast access to the wide variety of data. At the same time they contain a wealth of hidden knowledge that requires steps of extra processing in order to infer it. In this work we focus on extraction of such meta knowledge from the research bibliographic databases by looking at them from sociolinguistic, text mining and bibliometric perspectives. We choose the Digital Library and Bibliographic Database as a testbed for our experiments. In the framework of the sociolinguistic analysis we build a statistical system for the language identification of personal names. We show also that extension of a purely statistical model with the co-authors network boosts the system's performance. In the text mining scenario, we perform a number of experiments that focus on topic identification and ranking. While our topic detection approach remains generic and can be used for any kind of textual data, the topic ranking metrics are built upon the information provided by the bibliographic databases. The goal of our bibliometric study is to create a researcher's profile on DBLP and analyze some of the research communities defined by the different conferences, in terms of the publication activity, interdisciplinarity of research, collaboration trends and population stability. We also aim at exploring to what extent these aspects correlate with the conference rank. Each of the above topics constitutes a method of meta information extraction from bibliographic databases and other similarly structured data sources. [less ▲]

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See detailGeometry and Stochastic Calculus on Wasserstein spaces
Selinger, Christian UL

Doctoral thesis (2010)

P ([0, 1])) with respect to the Skorohod topology. In the last chapter we restrict ourselves to the space of histograms on the unit interval. We calculate the Wasserstein distances numerically and obtain ... [more ▼]

P ([0, 1])) with respect to the Skorohod topology. In the last chapter we restrict ourselves to the space of histograms on the unit interval. We calculate the Wasserstein distances numerically and obtain a Riemannian metric on the simplex. We investigate explosion behaviour of the respective diffusion processes in dimension 1 and 2. [less ▲]

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See detailPeer interactions in the primary classroom
Meyer, Anne UL

Doctoral thesis (2010)

The present research focuses on peer interactions engaged with the accomplishment of learning activities in the primary classroom. It is driven by the interest and need to understand learning and social ... [more ▼]

The present research focuses on peer interactions engaged with the accomplishment of learning activities in the primary classroom. It is driven by the interest and need to understand learning and social interaction taking place in peer group-s, and how the participants orient to the sequential organization of social interaction. The research draws on audio and video data stemming from the primary classroom in Luxembourg, and aims at 1) describing and analyzing the interactional organization of learning activities, 2) describing and analyzing the resources and methods, i.e. expert-novice-practices mobilized by young learners when orienting to the accomplishment of a learning activity, and 3) describing the opportunities for participation and for learning that may take place when learners orient to the accomplishment of a learning activity in peer interaction. Peer interaction is depicted as one form of a community of practice within which learning is situated and observable as learners in and through the deployment of expert-novice-practices orient to, and adapt to micro-shifts in the participation framework when accomplishing a learning activity. Results point to the fact that not only are expert-novice-practices deployed when young learners work in interaction, but these practices are also found to be inextricably linked to the constitution of expert-novice identities - this again has implications for how the learners orient to the accomplishment of a learning activity. [less ▲]

Detailed reference viewed: 87 (1 UL)
See detailLocal Languaging: Literacy Products and Practices in Gambian Society
Juffermans, Kasper UL

Doctoral thesis (2010)

Detailed reference viewed: 144 (1 UL)
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See detailPain modulation induced by Heterotopic Noxious Counter-Stimulation (HNCS) : psychophysiological assessment of adequate stimulation paradigms and sex-related effects
Streff, Anouk UL

Doctoral thesis (2010)

This work comprises three studies whose main concern was to find a valid tonic pain model able to trigger a genuine diffuse noxious pain inhibition. All studies were performed in healthy, drug-free ... [more ▼]

This work comprises three studies whose main concern was to find a valid tonic pain model able to trigger a genuine diffuse noxious pain inhibition. All studies were performed in healthy, drug-free volunteers and whereas the first two are validation studies, the third is an application study of the previous two. The aim of the first study was to characterize the cold pressor (CPT) and hot water immersion test (HIT) from a physiological and a psychophysical point of view. A second issue was to clarify the origin of potential autonomic responses during both tests; are they related to baroreflex activity or rather a consequence of the pain experience per se? The study was performed in 30 volunteers aged 19-57 (median 24) years, and consisted of a single session including one CPT (4 ± 0.2°C) and one HIT (47 ± 0.5°C) with a cut-off-point of 5 minutes. Participants were randomly assigned to sequence order (the sequence of both trials was alternated) and groups were paralleled with respect to gender. Cardiovascular, respiratory and electrodermal activities as well as subjective pain intensity were continuously monitored. Pain detection and tolerance thresholds as well as pain unpleasantness and nervous tension were assessed additionally. Both tests were found to be comparable with respect to intensity of subjective pain and time course, but a significantly higher blood pressure increase during CPT could be observed, compared to the HIT. In conclusion, the HIT appears to be less confounded with baroreflex activity and hence seems to be a more adequate tonic pain model. The second study tested the internal validity of inter-digital web pinching (IWP) with regard to its potential as DNIC-trigger. 24 gender-matched participants, aged 21-54 (median 25) years, volunteered for the controlled study. The protocol included the assessment of thermal and mechanical perceptual wind-up (WU) before and after a HIT (47.5 °C) or an IWP (15 N) of 2 minutes duration each. WU pain was induced by 10 repetitive (1 Hz) contact heat (max. 49°C; 5 5 mm thermode) or 10 ballistic impact stimuli (0.5 g at 9m/s) on the phalanges of the non-dominant hand. Cardiovascular and corrugator muscle activity as well as pain experience were permanently monitored. Both heterotopic noxious counter-stimulation (HNCS) types produced a similar pain experience, but a more pronounced cardiovascular activity was observed for the HIT. Painful water immersion is though accompanied by a stronger baroreceptor activity. WU pain was significantly reduced for both pain modalities, although the inhibition was somewhat stronger for the HIT than the IWP. The IWP, being practically uncontaminated by baroreflex sensitivity (BRS), proved its validity as DNIC-trigger. The third study investigated temporal characteristics of electrically elicited pain and nocifensive RIII-reflex activity in a gender-balanced sample of 28 volunteers aged 21-38 (median 27) years, using IWP as HNCS, a tonic pain model previously validated to be BRS-unrelated. Sex-related differences in the post HNCS time courses of pain perception were identified with women demonstrating a more rapid return to baseline compared to men. Interestingly, an opposite pattern was observed regarding nociceptive reflex activity with a steeper return rate of electromyographic responses in males, whereas those of women remained attenuated over the entire observation period. These findings may reflect a stronger defensive response to pain in women. [less ▲]

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See detailState Aid, Subsidy and Tax Incentives under EU and WTO Law
Micheau, Claire UL

Doctoral thesis (2010)

Detailed reference viewed: 158 (10 UL)
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See detailRobust Dominating Set based Virtual Backbones for Wireless Ad hoc Networks
Schleich, Julien UL

Doctoral thesis (2010)

Ad hoc networks are infrastructure-less spontaneous networks generally composed of wireless and mobile devices. From a practical point of view, ad hoc technologies offer solutions when infrastructure ... [more ▼]

Ad hoc networks are infrastructure-less spontaneous networks generally composed of wireless and mobile devices. From a practical point of view, ad hoc technologies offer solutions when infrastructure-based network are too costly, damaged or not suitable. Despite a wide panel of scenarios and the huge number of ad hoc capable devices currently in use, this technology is not widely used because of technical considerations mainly related to the lack of a global coordinator. In this thesis, we propose two different approaches to create virtual backbones in order to organize ad hoc networks. In a first time, we propose a centralized algorithm based on DC programming and DCA to solve the Min m-Vertex Dominating Set Problem and in a second part, we develop distributed and asynchronous algorithms, relying on 2-hop knowledge only, to build k-Vertex Connected m-Vertex Dominating Set-based Virtual Backbones. A global overview of the domain is provided through an extensive state-of-the-art and a hierarchical classification. The efficiency of both approaches is demonstrated with a wide panels of simulations, from randomly generated graphs to more realistic scenarios. [less ▲]

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See detailSignaling legitimacy for small and medium-size enterprises in transition environments - The case of the Bulgarian IT sector
Ivanova, Olga UL

Doctoral thesis (2010)

The process of institutional transition from one coordination mechanism to another one is an important period in the evolution of any society. Transitions are associated with fundamental political, legal ... [more ▼]

The process of institutional transition from one coordination mechanism to another one is an important period in the evolution of any society. Transitions are associated with fundamental political, legal, economic and social changes (Danis et al. 2010) affecting all aspects of life (Peng 2003). The transition from planned to open-market economy that has taken place in Central and Eastern Europe (CEE), East Asia, and the newly independent states of the former Soviet Union represents an institutional transition. An environment that goes through transition is characterized by high level of vulnerability and uncertainty which impacts all actors evolving in it, including the organizations (Peng 2003). The dynamic relationship environment-organization is reflected in the concept of legitimacy. Legitimacy is a pertinent concept to study the transition stage since it exists on the borderline between the organization and its environment. In transition environments, the processes of deinstitutionalization of the old structures and the reinstitutionalization of the new ones coexist. This leads to a lack of institutional framework to guide behavior of actors or a situation called institutional vacuum. Since institutions regulate economic exchanges (North 1990), the lack of them leads to elevated costs for all actors due to the proliferation of opportunistic behavior (Meyer 2001). In such environments, demonstrating legitimacy becomes crucial for the survival of structures and actors. Legitimation is sought by new elites (Raychev and Stoichev 2008), the government (Peng 2000a), the new laws, decrees and regulations (Stark 1992), and the private organizations (Peng 2000a). The success of the transition directly depends on the strategies of organizations evolving in such environments (Peng 2000). Small and medium-size enterprises (SMEs) play an important role as catalysts of the process of change (McIntyre 2003: 1) since they are expected to spur economic growth and employment (Peng 2000a), and maintain social peace (McIntyre 2003: 1). Despite their central role in transition environments, little is known about the challenges SMEs face and the actions that can be undertaken in order to overcome them (Danis, Chaburu and Lyles 2010). One of the main challenges of SMEs in transition environments is to demonstrate that they are legitimate players implying that they comply with the expectations of relevant stakeholders’ groups. The main objective of this study is to shed some light on how SMEs in transition environments gain organizational legitimacy necessary for obtaining stakeholders’ support. The interest of the study lies in the fact that if organizational legitimacy is problematic for all organizations due to changing norms, beliefs, and stakeholders’ expectations over time (Ashforth and Gibbs 1990), it is even more problematic for small organizations in transition environments since the norms, beliefs and expectations are not clearly defined. In order to address the legitimacy needs of small organizations in transition environments, I propose a signaling theory of legitimacy, which postulates that the legitimacy-claiming entities can rely on valid signals in order to demonstrate (communicate) their adherence to the requirements of the evaluating audiences. In general, the signaling theory of legitimacy should hold for any organization facing a liability - the discount the evaluating audiences place on it in comparison to its potential competitors. Organizations in transition environments face liability of origin (Bartlett and Ghoshal 2000) – a discount that the evaluating audiences (both domestic and foreign) may place on them based on their context of origin. For small organizations , the challenges resulting from liability of origin are even bigger because of their size, they are more prone to import instability from the environment. The higher level of vulnerability of small firms encourages them to engage in opportunistic behavior. Hence, demonstrating their legitimacy is a key issue for SMEs operating in transition environments. Organizational legitimacy becomes especially important when organizations engage in long-term arrangements since this requires an assessment of the organization not only in terms of its products/services but also in terms of its ongoing access to resources and capabilities as well as its reliability as a partner. In order to address the legitimacy needs of small firms evolving in transition environments and trying to obtain long-term partnerships, a new legitimacy typology is proposed. It is comprised of two types – functional and relational legitimacy. Functional legitimacy represents the adherence to the evaluating audiences’ requirements regarding relevant resources and capabilities. Relational legitimacy is the conformity with the evaluating audiences’ expectations regarding the reliability of an organization as a partner. Hence, this study addresses two research questions: 1. What are the dimensions (and valid signals) of functional and relational legitimacy (for small organizations in transition environment)? 2. Does using signals of specific types of legitimacy (depending on the liability faced) enhance organizational legitimacy? This doctoral research examines the legitimacy challenges of SMEs in transition environments trying to obtain long-term arrangements. In the first part of the study, the two types of legitimacy - functional and relational legitimacy - are constructed. Similar to organizational legitimacy (Deephouse and Carter 2005), functional and relational legitimacy are also multidimensional constructs comprised of different facets. In the second part, I examine whether the signals of functional and relational legitimacy help SMEs in transition environment gain organizational legitimacy. The research model is tested on data collected from the information technology (IT) sector in Bulgaria. Based on the data analysis and results, this research has several theoretical and methodological contributions. The results also have practical implications for the managers of small organizations in transition environments as well as the public policy agents. The theoretical contributions are associated mainly with the signaling theory of legitimacy. It looks at how organizations can overcome certain liabilities by communicating their adherence to the expectations of relevant stakeholders’ groups. Organizations can demonstrate their conformity to the evaluating audiences’ requirements by using valid signals – organizational characteristics that can be observed, are costly to imitate and are based on shared meaning between the sending and the receiving party. In addition, the study contributes to the literature on transition environments by looking at the particular case of SMEs and their attempt to demonstrate that they are legitimate players when trying to engage in long-term arrangements. The methodological contribution lies in the way the two types of legitimacy (functional and relational) are measured via formative measurement constructs (Diamantopoulos and Winklhofer 2001; Jarvis et al. 2003) under the partial least squares (PLS) technique. Formative constructs are associated with causality that goes from the manifest (directly observable) variable to the latent construct or in other words, the manifest variables cause/build the latent construct (Diamantopoulos 1999). This made possible to match the legitimacy claims of organizations from once side based on the functional and relational signals and the legitimacy granted by relevant stakeholders’ groups, on the other side. In addition, the research contributes to the growing number of studies in strategic management that use PLS as a structural equation modeling technique (Birkinshaw et al. 1995; Cool et al. 1989; Fornell et al. 1990; Johansson and Yip 1994; Tsang 2002). The practical implications of this research shed some light on which signals (organizational characteristics) are important for managers of small organizations in transition environments. Signals are costly and since all organizations (and especially small firms) have limited resources, managers have to know which signals to invest in. It is important to note that many managers disregard the relational aspect of their legitimacy claims which (based on the results of the study) are more important in the communication process between the legitimacy-claiming and legitimacy-granting entities. Overall, this study represents a fertile area for future research. Researchers can test the signaling theory of legitimacy in other contexts – i.e., other transition environments (Eastern Europe vs. China), as well as compare the signals used by organizations in transition environments and developed economies. Researchers can also test the signaling theory of legitimacy on organizations facing different liabilities (i.e. liability of market newness) and try to extend the existing legitimacy typologies. In addition, future studies can focus on issues of meaning construction (based on signals) in the communication process between organizations. [less ▲]

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See detailDie nationalsozialistische Kunst- und Kulturpolitik im Grossherzogtum Luxembourg 1934-1944
Lorent, Catherine UL

Doctoral thesis (2010)

This study is about the art and history in Luxembourg from 1934-1944. This decade where Luxembourg was occupied by Nazi Germany from 1940 to 1944, has not yet been represented focusing on the visuals arts ... [more ▼]

This study is about the art and history in Luxembourg from 1934-1944. This decade where Luxembourg was occupied by Nazi Germany from 1940 to 1944, has not yet been represented focusing on the visuals arts facing the national socialist oppressions and propaganda due to the tabooization of these years. After an incipient view about the development of the arts in Luxembourg during the 1930’s, the influence of the german propaganda through the Gesellschaft für Deutsche Literatur und Kunst and about the reception of the Nazi art politics in the Luxembourgish press, the national-socilalist politics of art culture and the effects on the Luxembourgish art scene are presented. during the occupation by the Hitler State. The aim is to gain a particular view about the germanisation of Luxembourgish art, artists and cultural institutions while Luxembourg had become a part of Gau Moselland. The themes pictured by the artists are analyzed in a way to show the propagandistic value of the caracteristics of a « regional » art for national-socialist art politics. Two Major questions are examined : How the artists dealed with the political and social upheavals in their country and : Were collaboration or resistance the only options to face the cultural oppressions of the Nazis ? [less ▲]

Detailed reference viewed: 166 (8 UL)
See detailCarbon Lock-in in der Automobilindustrie?
Maier, Urs UL

Doctoral thesis (2010)

Detailed reference viewed: 49 (7 UL)
See detailEfficient Data Dissemination Techniques For Multi-Hop Wireless Networks Applied to Vehicular Communications
Frank, Raphaël UL

Doctoral thesis (2010)

Multi-Hop Wireless Networks (MHWN) are composed of devices called nodes, which communicate in an ad hoc fashion. Such networks allow the relaying of transmissions over multiple wireless hops to provide an ... [more ▼]

Multi-Hop Wireless Networks (MHWN) are composed of devices called nodes, which communicate in an ad hoc fashion. Such networks allow the relaying of transmissions over multiple wireless hops to provide an extended service area. There are two main classes of MHWN. The first includes all networks that have a static network topology, e.g. Wireless Mesh Networks and Wireless Sensor Networks. The second specifies networks with a dynamic or mobile topology, e.g. Vehicular Networks. For both types, collaborative applications are of great importance. In such a scenario, information needs to be made available to multiple, or sometimes all nodes in the network. The trivial method, pure network flooding, is to retransmit the information at every hop exactly once. In previous studies it has been shown that such an approach considerably lowers the overall performance of the network by saturating the shared communication channel. In this thesis, we present two different approaches that perform efficient data dissemination among collaborative nodes in MHWNs. The primarily objective is to reduce the number of redundant retransmissions by selecting only a subset of nodes to be responsible for relaying the information without compromising global delivery. We propose one approach for each of the two classes using different methodologies. For static network topologies, we present a novel heuristic based on the Minimum Connected Dominating Set problem. This approach allows the election of a near-optimal set of relays that are able to reach every other node in the network, thus minimizing the number of retransmissions. We theoretically and experimentally validate our approach and compare it to other state-of-the-art dissemination techniques. For dynamic network topologies, we focus primarily on Vehicular Networks. We present a new routing protocol that makes use of an efficient dissemination technique to find robust communication paths between two vehicles. Strategic vehicles are elected as relays based on their position and on information about the local neighborhood. The protocol is evaluated using a novel simulation framework that takes into account specific characteristics of vehicular networks in urban environments, e.g. mobility of the vehicles and signal propagation. The performance evaluation shows that our protocol introduces only a low control overhead and provides robust communication paths that achieve high delivery ratios. [less ▲]

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See detailAnalysis and modelling of the noise generation during vibratory pile driving and determination of the optimization potential
Hanus, Vincent UL

Doctoral thesis (2010)

Impact driving, pressing and vibrodriving are the three main methods to drive sheet piles. The sound level generated during vibrodriving varies almost between the very high level of an impact driving and ... [more ▼]

Impact driving, pressing and vibrodriving are the three main methods to drive sheet piles. The sound level generated during vibrodriving varies almost between the very high level of an impact driving and the lowest sound level of a pressing. In the first part of this doctoral thesis, sound measurements feasibility is thoroughly studied. Particular attention is paid to the measurement conditions on construction sites and to the measurement methods (sound power level, beamforming and thermography). These methods are outlined and the provided results are compared. In addition, the different causes of noise are analysed and the influence of various parameters is quantified. In the second part, the acceleration measurements of the full-scale experiments are used to calibrate a Finite Element model. A parametric study analyses how the most important mechanical parameters influence the noise level. This research has shown that a decrease of the noise generation on construction sites can be obtained by two ways: by recommendations for installation of sheet piles at the construction site, and by requirement of constructive measures that significantly reduce the noise level. [less ▲]

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See detailUnderstanding and leveraging the social web for information retrieval
Noll, Michael UL

Doctoral thesis (2010)

Detailed reference viewed: 39 (1 UL)
See detailTree-Based computation in probalistic models
Ignac, Tomasz UL

Doctoral thesis (2010)

Detailed reference viewed: 47 (3 UL)
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See detailJanus kinases as targets for small molecule inhibitors
Kaczor, Jakub UL

Doctoral thesis (2010)

Many cytokines transduce signals by employing receptor/Janus kinase (Jak) complexes that, once activated, promote phosphorylation of several signaling proteins such as STAT transcription factors. The Jak ... [more ▼]

Many cytokines transduce signals by employing receptor/Janus kinase (Jak) complexes that, once activated, promote phosphorylation of several signaling proteins such as STAT transcription factors. The Jak/STAT pathway is normally tightly modulated by regulatory mechanisms preventing its over-activation. However, a number of genetic alterations in Jak kinase genes have been found in myeloproliferative neoplasms and leukemia that render the Jaks hyperactive and cytokine-independent. In the present thesis pharmacologic and genetic approaches were applied to study aspects of both the cytokine-dependent and -independent activation of the Jak/STAT pathway. We applied a chemical genetics approach to Janus kinases and generate analogue-sensitive Jak1 and Jak2 mutants. With these tools we could for the first time specifically inhibit either Jak1 or Jak2 and investigate their relative contributions in IFN signaling. Single inhibition of either Jak by an inhibitor analogue showed differential effects on IFN-mediated STAT1 phosphorylation, Jak2 inhibition having a stronger suppressive effect. Furthermore, we identified STAT1 and IRF1 as genes, whose increased expression upon IFN stimulation strongly depends on active Jak2 but not on Jak1. Most of the IFN-regulated genes, however, depend on both Jak1 and Jak2 activity. Exploiting this quick and reversible pharmacological inhibition of analogue-sensitive kinases we address the temporal requirement of Jak activity and the importance of different phases of the IFN response. Moreover, we further characterized constitutively active Jak2 mutants and show that SOCS proteins seem to be directly involved in their proteasome-mediated degradation. There is an increasing interest in developing small molecule inhibitors targeting Jaks and Jak mutants. We show that Erlotinib, an inhibitor targeting EGFR which is already used in the clinic to treat lung and pancreatic cancer, can have a beneficial additional effect if combined with a Jak-specific inhibitor on cell growth suppression and apoptosis of Jak2-V617F- or Jak3-A572V-positive leukemic cells. Erlotinib, in contrast to Jak inhibitors targeting Jaks directly affects the eIF2/ATF4 pathway in leukemic cells. This is of general interest since Erlotinib treatment in conjunction with other kinase inhibitors could be an interesting approach also in other kinase-dependant leukemias (e.g. BCR-ABL-positive CML). [less ▲]

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See detailEssays in international finance
Vermeulen, Robert John Gerard UL

Doctoral thesis (2010)

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See detailCompatibilités et incompatibilités liants cimentaires / superplastifiants
Nicolas, Edwige UL

Doctoral thesis (2010)

Currently required concrete strength imposes a lower water/cement ratio and use of superplasticizer to make easier the fresh material implementation. Polycarboxylate type products are very effective in ... [more ▼]

Currently required concrete strength imposes a lower water/cement ratio and use of superplasticizer to make easier the fresh material implementation. Polycarboxylate type products are very effective in the short term but can lead to a fast loss of workability in case of binder/superplasticizer incompatibility. The object of this work is the identification of cementitous phases involved in these rheological variations. Initially, flow of various superplasticized pastes is evaluated by a rheometer fitted with a ball measuring system. Compatible combinations flow like a Bingham’s fluid. An incompatibility results in an increase of yield stress and plastic viscosity or rheological properties evolution into Herschel-Bulkley’s fluid. Then, cement/superplasticizer combinations are characterized by rheological tests. Stiffening assessment of pastes and chemical characterisation of hydrated cements show that consistency is associated with amount and microstructure of formed ettringite. These parameters depend on initially present aluminate phase and calcium sulphates. Finally, study of synthetic cementitous systems states that calcium sulphates solubility, in presence of superplasticizer, is increased probably because Ca2+ ions complexation by polycarboxylates. As for the orthorhombic variety of aluminate phase, more reactive than cubic variety, it leads to a large amount of needle-shaped ettringite. [less ▲]

Detailed reference viewed: 102 (4 UL)
See detailL'investisseur face aux réseaux de distribution d' OPCVM
Borissova, Miroslava Andonova UL

Doctoral thesis (2010)

Detailed reference viewed: 64 (4 UL)
See detailNew approaches to the cryptanalysis of symmetric primitives
Khovratovich, Dmitry UL

Doctoral thesis (2010)

Detailed reference viewed: 70 (5 UL)
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See detailMechanische und thermische Untersuchungen zur Entwicklung eines Wärmedämmsteines aus Leichtbeton
Leufgens, Nadine UL

Doctoral thesis (2010)

The current discussion about the necessity of sustainable reduction of primary energy for heating of housing structures and of CO2 – emissions led the University of Luxembourg to issue a project to ... [more ▼]

The current discussion about the necessity of sustainable reduction of primary energy for heating of housing structures and of CO2 – emissions led the University of Luxembourg to issue a project to develop hybrid light-weight concrete blocks with high heat-insulating properties. Therefore, the demand for wall constructions limiting the heat flow through the outer wall was steadily growing. Because of the progressing standard of national and European Energy Saving Regulations for housing structures and office buildings in the past years, most of the producers of bricks and concrete masonry blocks were forced to develop new, innovative wall materials and constructions. For assessing the real actual state of the art of masonry blocks, 15 different bricks and blocks were taken from European free market as samples. It was shown, that especially for highly-heat insulating masonry lightweight concrete blocks (e.g. Vbl SW 2) with dry densities below 800 kg/m3 an optimization potential still exists. A relevant aspect for a critical estimation of a wall construction is the knowledge of mechanical and thermal lightweight aggregate concrete (LAC) parameters. The present work describes investigations for determining design limit values of the thermal and mechanical properties of LAC. Based on this, a mathematical approach to describe the strength, the thermal conductivity and for e.g. the stress-strain-relationship linked to the dry density in a range between 500 and 2000 kg/m3 was derived. For studying the material behavior of LAC, specimens were produced in laboratory tests as well as in the production line by fabricating solid lightweight concrete blocks without inner air holes. Due to the unsatisfying results of the market study, further investigations had to be done to determine the influence of size and slenderness effects on the strength of solid specimen and masonry blocks with inner air holes made of LAC. Additionally, combined influencing factors were studied on block sections cut out of hollow and solid masonry blocks. In the following, the experimental results were verified by simulations with the Finite-Element-Method using the commercial software ANSYS© for modeling different LAC-specimen geometries and the influence of the kind of load applications by a contact zone between steel plates and specimen. Subsequently, the results of these investigations and the achieved knowledge of the influencing factors on the load carrying capacity of the block structures lead to an analytical model approach for design purpose of masonry blocks based on the elasticity theory. This model allows quantitative predictions of the load bearing strength of hollow and solid masonry blocks with inner air holes arranged in a grid system. The analytical model is verified by comparison of experimental results of different block geometries. Finally, the knowledge of the load carrying behavior of different LAC specimen geometries achieved by various experimental and numerical results contribute to the construction of new prototypes of heat insulating masonry blocks made of LAC. Based on the results of the market study and numerical parameter studies, it is revealed that it is suggestive to separate the load bearing from the thermal function of the block by developing 3-layered Sandwich and composite blocks made of an insulating and load bearing part. [less ▲]

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See detailHydrological effects on gravity at the station of Walferdange, Luxembourg
Lampitelli, Carmine UL

Doctoral thesis (2010)

In this study, we look at the physical relationship between water storage variations driven by local precipitation events and local gravity changes at Walferdange, in the Grand Duchy of Luxembourg. A ... [more ▼]

In this study, we look at the physical relationship between water storage variations driven by local precipitation events and local gravity changes at Walferdange, in the Grand Duchy of Luxembourg. A synthesis of the different approaches that can be found in recent literature is proposed. Then, a new and simple scheme is provided to remove the effects of precipitation events in the gravity observations, For the gravity observations, we use the data collected by the superconducting gravimeter CT040 (SG) located in the Walferdange Underground Laboratory for Geodynamics (WULG), which provides high resolution relative gravity measurements from December 2003. In addition, a statistical analysis is presented to determine the correlation between the gravity signal variations registered by the SG and the water level of the nearby flowing Alzette River. The idea is that the gravity variation due to the precipitation should appear before the change in river level. Contrarily to the simple precipitation data, the gravity observation should also contain information on the degree of soil saturation, which depends on processes having a seasonal variability, as evapotranspiration, and on hydrogeological parameters like hydraulic conductivity. Understanding the relationship and temporal dependence between the observed precipitation and the gravity changes might improve the capacity to predict extreme events like flooding. [less ▲]

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See detailLe transfert des sûretés
Westendorf, Hannes UL

Doctoral thesis (2010)

Detailed reference viewed: 87 (1 UL)
See detailLaw-aware access control for international financial environments
Stieghahn, Michael UL

Doctoral thesis (2010)

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See detailAdaptive high-gain extended kalman filter and applications
Boizot, Nicolas UL

Doctoral thesis (2010)

The work concerns the ``observability problem” --- the reconstruction of a dynamic process's full state from a partially measured state--- for nonlinear dynamic systems. The Extended Kalman Filter (EKF ... [more ▼]

The work concerns the ``observability problem” --- the reconstruction of a dynamic process's full state from a partially measured state--- for nonlinear dynamic systems. The Extended Kalman Filter (EKF) is a widely-used observer for such nonlinear systems. However it suffers from a lack of theoretical justifications and displays poor performance when the estimated state is far from the real state, e.g. due to large perturbations, a poor initial state estimate, etc… We propose a solution to these problems, the Adaptive High-Gain (EKF). Observability theory reveals the existence of special representations characterizing nonlinear systems having the observability property. Such representations are called observability normal forms. A EKF variant based on the usage of a single scalar parameter, combined with an observability normal form, leads to an observer, the High-Gain EKF, with improved performance when the estimated state is far from the actual state. Its convergence for any initial estimated state is proven. Unfortunately, and contrary to the EKF, this latter observer is very sensitive to measurement noise. Our observer combines the behaviors of the EKF and of the high-gain EKF. Our aim is to take advantage of both efficiency with respect to noise smoothing and reactivity to large estimation errors. In order to achieve this, the parameter that is the heart of the high-gain technique is made adaptive. \textit{Voila}, the Adaptive High-Gain EKF. A measure of the quality of the estimation is needed in order to drive the adaptation. We propose such an index and prove the relevance of its usage. We provide a proof of convergence for the resulting observer, and the final algorithm is demonstrated via both simulations and a real-time implementation. Finally, extensions to multiple output and to continuous-discrete systems are given. [less ▲]

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See detailTolérance aux fautes et reconfiguration dynamique pour les applications distribuées à grande échelle
Besseron, Xavier UL

Doctoral thesis (2010)

This work deals with high performance computing on large scale platforms like computing grids. Computing grids are characterized by (1) frequent changes in execution context and, especially, by (2) a high ... [more ▼]

This work deals with high performance computing on large scale platforms like computing grids. Computing grids are characterized by (1) frequent changes in execution context and, especially, by (2) a high failure probability caused by the large number of components. Running an application efficiently in such an environment requires to consider these parameters. Our research work is based on the abstract representation of the application as a data flow graph from the parallel and distributed programming model Athapascan/Kaapi. This abstract representation is used to provide solutions for (1) dynamic reconfiguration and (2) fault tolerance issues. - First, we propose a dynamic reconfiguration mechanism that manages, transparently for the reconfiguration programmer, concurrent operations on the application state and mutual consistency of states for distributed reconfiguration. - Secondly, we present an original fault tolerance protocol that allows partial rollback of the application in case of failure. For this purpose, the set of strictly required computation tasks to recover is computed. These contributions are evaluated through the Kaapi and X-Kaapi software on the Grid'5000 computing platform. [less ▲]

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See detailPRISMA: A Software Product Line-oriented Process for the Requirements Engineering of Flexible Transaction Models
Gallina, Barbara UL

Doctoral thesis (2010)

Engineering the requirements of the right transaction model (right with respect to the business goals of the application to be supported) is a hard task since it involves the critical choice of the right ... [more ▼]

Engineering the requirements of the right transaction model (right with respect to the business goals of the application to be supported) is a hard task since it involves the critical choice of the right degree of ACIDity, that is the right selection of requirements in terms of Atomicity, Consistency, Isolation and Durability, which altogether are fundamental to ensure dependability and, more specifically, reliability. Up to now, this task is definitively not supported by a process. This thesis provides a novel process, called PRISMA. PRISMA is a Process for Requirements Identification, Specification and Machine-supported Analysis that targets transaction models. PRISMA is helpful as a prism in the identification of fundamental and constituting properties of transaction models to achieve, as a result of the PRISMA process, a correct and valid requirements specification. The main idea behind PRISMA is that transaction models may be considered as a product line and that variabilities and commonalities may be identified to distinguish similarities and differences among "products". Specifically, PRISMA is conceived for engineering the specification of a transaction model by placing the effort in revealing its Atomicity, Consistency, Isolation and Durability requirements, which represent the variabilities of the product line. PRISMA contributes on one hand in increasing quality, in particular dependability, and on the other hand in reducing time to market and cost by intensifying reusability. [less ▲]

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See detailReliable information acquisition in the presence of malicious sources
Staab, Eugen Valentin UL

Doctoral thesis (2010)

In distributed systems in which autonomous entities exchange information with each other, these entities have the freedom to provide incorrect information. This becomes especially relevant in scenarios ... [more ▼]

In distributed systems in which autonomous entities exchange information with each other, these entities have the freedom to provide incorrect information. This becomes especially relevant in scenarios where entities have incentives to do so, e.g., in peer-to-peer networks or volunteer computing systems. Cryptographic mechanisms can help to ensure data integrity and authenticity. However, while these mechanisms achieve a reliable transmission of information, they do not prevent the creation of incorrect information in the first place. Therefore, additional mechanisms are necessary to enable an entity to assess the correctness of acquired information. In specific applications, the correctness of acquired information can be verified, or be assessed by means of plausibility checks. This is not possible in general, though. Often the explicit verification of information is infeasible, for instance due to high costs. In this thesis, we investigate different generic approaches to ensure the correctness of information without explicitly verifying it. More precisely, we propose three mechanisms, each of which is suitable for certain scenarios and tasks: a spot-checking mechanism that uses known facts to ensure the correctness of acquired information; an evidence-based trust model that learns – based on past experience – to exclusively select trustworthy sources; and a collusion detection algorithm that addresses the main threat to mechanisms that ensure the correctness of information by means of redundancy. The proposed mechanisms are validated, theoretically and/or experimentally, against plausible attack strategies of malicious sources. We show that our mechanisms are able to deal with different kinds of attack strategies, and that our trust model and the collusion detection algorithm successfully identify malicious sources. [less ▲]

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See detailContribution à l'étude de la notion de crime organisé en Europe: L'exemple de la France et de la Grèce
Rodopoulos, Ioannis UL

Doctoral thesis (2010)

The presented study examines the juridical, socio-political and epistemological implications, caused by the insertion of the concept of organised crime into the European penal legislations, precisely the ... [more ▼]

The presented study examines the juridical, socio-political and epistemological implications, caused by the insertion of the concept of organised crime into the European penal legislations, precisely the French and Greek ones. Firstly, the study concerns the process by which the preexistent legal notions concerning criminal participation and group-based offenses have gradually been replaced by an allegedly univocal notion of organised crime, as well as the consequences of this substitution for the concerned juridical systems. This study of the “sein” of contemporary policy towards organised crime, invites us to think also about its “sollen”. The serious legal-dogmatic problems and the semantic entropy inherent to the concept, combined with the justified worries about the politico-philosophical orientations of contemporary criminal policy systems, lead us to rethink not only the utility of the juridicisation of a concept which is ontologically inappropriate for scientific treatment, but also the latent manichean tendencies behind this process; tendencies which, much more than organised crime itself, threaten the declared values of our societies and our justice systems. [less ▲]

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See detailNew tools for conviviality. Masks, norms, ontology, requirements and measures. Bridging the conviviality gap between policy and informatics
Caire, Patrice UL

Doctoral thesis (2010)

The notion of conviviality has an intuitive meaning for human society, which is to feel welcome in a community and at ease with its members. We believe it also has particular significance for the design ... [more ▼]

The notion of conviviality has an intuitive meaning for human society, which is to feel welcome in a community and at ease with its members. We believe it also has particular significance for the design of artificial social systems. Traditionally conviviality has been shown to be useful in human interactions, thus the abundance of artificial social systems is likely to benefit from its application. In this thesis, we explore the possibility of developing the concept of conviviality in artificial social systems in depth. We provide a number of tools to help designers of artificial social systems to include conviviality at the onset of their design. First, we identify what we believe to constitute a promising field of research. Second, we abstract the notion of conviviality. Starting from the philosophical notion proposed by Illich, “individual freedom realized in personal interdependence”. Using Taylor’s intuition about a conviviality mask, we advance a formalization in terms of interdependence of agents and their goals, and the social norms that determine that interdependence. Third, we operationalize conviviality for the development of artificial social systems. We establish correspondence between software engineering and social science domains. We formalize the interdependence between members of a group with dependence networks, and use the stakeholder-agent concept to pro- vide individual agents’ points of view. Fourth, we propose a way to elicit conviviality requirements during the early phase of the development of artificial social systems, using the Tropos agent methodology. Finally, we provide a glimpse of the type of conviviality properties that can be measured in artificial social systems, and thus define the convivial quality of the system. Throughout this thesis we illustrate our arguments with two running examples, one from Second Life, the other from the city of Luxembourg. [less ▲]

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See detailAlgorithms mapping into elliptic curves and applications
Icart, Thomas UL

Doctoral thesis (2010)

Detailed reference viewed: 93 (7 UL)
See detailK-Anonymity in Mobile Ad-Hoc Networks
Spiewak, Dagmara UL

Doctoral thesis (2010)

Detailed reference viewed: 60 (4 UL)
See detailAnalyse harmonique sur certains groupes de Lie à croissance polynomiale
Lahiani, Raza UL

Doctoral thesis (2010)

Detailed reference viewed: 46 (1 UL)
See detailApproaches for collaborative filtering in distributed environments
Gratz, Patrick UL

Doctoral thesis (2010)

Detailed reference viewed: 42 (3 UL)
See detailTopology dynamics and secure routing for predictable mobile networks
Fischer, Daniel UL

Doctoral thesis (2010)

Detailed reference viewed: 259 (3 UL)
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See detailSemiotik der digitalen Medienkunst: Eine funktionale Kunstbetrachtung
Huemer, Birgit UL

Doctoral thesis (2010)

Art-forms, which use digital technologies for production and design and which reflect these technologies critically, are becoming increasingly popular. Caused by technological development, art production ... [more ▼]

Art-forms, which use digital technologies for production and design and which reflect these technologies critically, are becoming increasingly popular. Caused by technological development, art production and design has changed considerably during the last years. Nowadays digital artworks are generated multimodally and integrate the visitor and the environment as represented and interactive participants into their work. In order to explore the meaning making potential of these artworks, I develop a systemic functional framework of analysis. This framework combines a sociological and a formal approach and offers an alternative perspective to enrich our knowledge and perception when engaging with art. It enables researchers to relate art and culture with communicative events and to analyse the interaction and exchange going on between artist, artwork, visitor and environment by describing semiotic resources that are used to generate digital artworks. The developed framework is a multimodal approach, based on semiotics and functional theory, which applies a sociological concept and functional categories to the analysis of multimodal texts. This multimodal approach enables researchers to explain how different semiotic systems or modes (language, image, sound, body language, facial expression and three-dimensional spaces, etc.) are related to each other in different genres such as every day language, scientific texts and art to realise meanings. Hitherto multimodal analysis has basically focused on the combination and relation of only two modes in a text (i.e. language and image). By analysing artworks that are generated of verbal, visual and acoustic modes of communication as well as physical objects in three-dimensional space the multimodal approach is extended in this thesis. Thus this work will contribute to multimodal research and art and media theory. With this framework of analysis major principles of design in digital art, that have become significant within the last years, can be explained. Principles that are addressed in this thesis are: transformation, modification and translation from one mode into another, virtual environments and telepresence, creating new visitor perspectives and interactive concepts as well as cohesion in digital art. [less ▲]

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See detailExperts going transnational: education at world exhibitions during the second half of the nineteenth century
Dittrich, Klaus UL

Doctoral thesis (2010)

This thesis investigates the educational sections of the great international exhibitions of the latter half of the nineteenth century. This thesis takes into account the participation of actors from ... [more ▼]

This thesis investigates the educational sections of the great international exhibitions of the latter half of the nineteenth century. This thesis takes into account the participation of actors from France, Germany, Japan and the United States. Focusing on education experts, this thesis is a contribution to a sociocultural history of an intellectual and administrative elite in an age of early globalisation. World exhibitions were one of the major media for the transnational circulation of educational knowledge. The central question is why education experts from these four countries invested so many resources in order to prepare and visit world exhibitions. Why did they go transnational? The thesis proposes two answers. Firstly, education experts used world exhibitions in order to appropriate the most advanced pedagogical models for their own institutional contexts. The concept of cultural transfers is a useful tool to analyse these appropriations. Knowledge circulation at world exhibitions made a crucial contribution to the institutionalisation of primary education and technical education. Secondly, education experts used world exhibitions to stage their own institutions on an international stage. The proud representation of the educational achievements of one’s own context was the final phase of successful cultural transfers. Educational displays became increasingly embedded in nationalist discourses. During the 1870s pedagogical know-how circulated relatively easily. Towards the turn of the century the self-representation of institutions became predominant. This original approach aims at furthering the understanding of globalisation in the nineteenth century. Still, the thesis argues that world exhibitions were in a large measure media for transnational professional discourses in many fields, including education. [less ▲]

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See detailSocial Spatial Difference Delimiting Borders in Berlin
Carr, Constance UL

Doctoral thesis (2010)

Detailed reference viewed: 94 (7 UL)
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See detailLa médiation de l’archéologie à la télévision : la construction d’une relation au passé.
Schall, Céline UL

Doctoral thesis (2010)

À l’heure actuelle, les occasions de « rencontrer » des hommes du passé (ou du moins leurs représentants) se multiplient : l’exposition d’archéologie ne présente plus seulement des objets, mais fait ... [more ▼]

À l’heure actuelle, les occasions de « rencontrer » des hommes du passé (ou du moins leurs représentants) se multiplient : l’exposition d’archéologie ne présente plus seulement des objets, mais fait découvrir au visiteur le mode de vie des anciens habitants d’un lieu ; les reconstitutions historiques font « revivre » des hommes du passé et mettent en scène courses de chars, artisanat et autres gestes « ancestraux » devant les yeux du public ; et enfin, les guides de monuments historiques prennent les traits de personnages-types, favorisant l’immersion et l’attachement au lieu. De la même manière, les émissions de télévision sur l’archéologie semblent de plus en plus effacer le scientifique et les vestiges du dispositif ; proposant ainsi une relation plus directe au passé et à l’homme du passé (c’est le cas par exemple de docufictions comme Homo Sapiens de Jacques Malaterre). Cette recherche questionne ainsi la relation au passé, proposée par les émissions de télévision sur l’archéologie. Comment ces films peuvent-ils créer une relation à la fois scientifique et symbolique au passé et à « l’autre » ? Quels sont les effets de cette nouvelle forme de médiation qui feint de s’effacer ? À l’inverse, quels sont les effets de l’affirmation du dispositif de médiation (dans les documentaires et les reportages) ? Pour répondre à ces questions, nous avons adopté une démarche « feuilletée », en « entonnoir ». Un corpus de référence réunit d’abord toutes les émissions sur l’archéologie diffusées entre 1995 et 2008, sur la télévision hertzienne française. Son analyse statistique permet de dégager des tendances générales quant à la représentation de l’archéologie à la télévision. Ensuite, l’analyse sémiopragmatique d’un corpus test de 13 émissions sur Pompéi, mène à la constitution d’un modèle d’analyse de la médiation du passé et d’un outil permettant la systématisation du recueil de données sur un grand nombre d’émissions. Enfin, un troisième corpus de 51 émissions permet la vérification de ce modèle et aboutit à l’identification de quatre types de construction de la relation au passé. L’apport de l’étude est triple : 1) elle génère des connaissances sur l’objet de recherche lui-même, c’est-à-dire sur les représentations les plus courantes de l’archéologie à la télévision ; 2) elle propose une méthodologie et un modèle d’analyse de la médiation fondés sur des outils issus de la sémiopragmatique ; 3) enfin, d’un point de vue théorique, la recherche permet d’envisager la médiation, non comme un lien sociétal ou un « entre-deux », mais comme une stratégie de modulation de la distance, possible notamment grâce à l’intervention de « figures » de médiation. Ces figures sont des éléments référentiels qui cristallisent des représentations sociales et qui ont des rôles à jouer dans l’énonciation et la narrativité de l’émission. [less ▲]

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See detailBearing capacity of steel fiber reinforced concrete flat slabs
Michels, Julien UL

Doctoral thesis (2009)

Detailed reference viewed: 184 (9 UL)
See detailJeunesses et respect dans une société fragmentée En quoi respect et reconnaissance sont au cœur des constructions identitaires des jeunes et de leur intégration dans la société ?
Kerivel, Aude UL

Doctoral thesis (2009)

La société s’interroge sur les actes irrespectueux de certains jeunes et ces derniers demandent du respect. Un paradoxe qui nous amène à donner la parole aux jeunes afin de comprendre le sens qu’ils ... [more ▼]

La société s’interroge sur les actes irrespectueux de certains jeunes et ces derniers demandent du respect. Un paradoxe qui nous amène à donner la parole aux jeunes afin de comprendre le sens qu’ils donnent au respect. D’un point de vue théorique et empirique, le respect se caractérise par sa pluralité de sens (dans la forme et le fond) et se définit souvent par son contraire : l’irrespect. Les deux sont directement liés : agir de manière irrespectueuse peut être un moyen de tenir l’autre en respect. L’irrespect subit par les jeunes nous conduit alors à considérer ces expériences en tant que relation intersubjective au travers de l’identité de l’offenseur et de l’offensé. Perçue comme égalitaire et réciproque, la relation de respect implique dans les discours des jeunes une hiérarchie ; celle ci nous amenant à interroger la notion d’autorité. L’autorité, autrefois inhérente au rapport entre adultes et jeunes, est aujourd’hui tantôt contestée, tantôt perçue comme une nécessité. Dans le contexte d’une société que l’on peut qualifier de fragmentée, la quête de respect nous semble au cœur des constructions identitaires des jeunes et de leur intégration. Les jeunes se trouvent au centre de multiples paradoxes : une liberté restreinte parmi des possibles déterminés, une égalité inaccessible dans la distribution de l’estime et une fraternité remise en cause par la lutte des places. Pour les jeunes, le respect serait le langage de la reconnaissance permettant la mobilité dans l’espace-temps. Une mobilité conditionnée par le fait d’avoir été considéré comme valable dans le regard de l’Autre et donc la possibilité de se percevoir comme respectable. [less ▲]

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See detailNichtgleichgewichtsphänomene, Strukturbildung und Grenzflächeneinflüsse in netzwerkbildenden Systemen aus optischer und akustischer Sicht.
Philipp, Martine UL

Doctoral thesis (2009)

Isostructural phase transitions occurring under non-equilibrium conditions are investigated using technologically relevant epoxies. The evolution of the hypersonic and optical properties during the ... [more ▼]

Isostructural phase transitions occurring under non-equilibrium conditions are investigated using technologically relevant epoxies. The evolution of the hypersonic and optical properties during the genesis of the polymeric network leads to deeper insight into the chemically induced sol-gel transition and glass transition, as demonstrated e.g. by the elastic anharmonicity and the generalised Cauchy relation. During gelation the refractive index versus chemical conversion behaves in an unexpected manner, indicating that in addition to the mass density an excess polarisability seems to contribute to the optical polarisability. The clarification of the isostructural phase transitions is impeded by the demixing tendency of the epoxy components which leads to different types of epoxy inhomogeneities on the nano- to mesoscopic scale. Taking benefit from a sample arrangement where both epoxy components are layered, the spatio-temporal evolution of acoustic properties gives supplementary information about trans-interfacial transport and structure formation processes. Of special technological relevance, but also of fundamental interest, is the influence of nanoscopic disturbances placed into the epoxy matrix. So-called interphases surrounding the nanoparticles modify and complicate the epoxy network formation, leading to long-lived metastable morphologies and properties. The role of the mixing sequence of the epoxy resin, the hardener and the nanoparticles for the polymerised epoxy state and the transient states during network formation, as well as the isostructural phase transitions is further elucidated. [less ▲]

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See detailZur Rotationskapazität von Verbundanschlüssen bei der Bemessung nach dem Fließgelenkverfahren
Hahn, Christoph UL

Doctoral thesis (2009)

The present work deals with the load bearing and rotational behaviour of composite connections in steel and concrete constructions. For typical buildings, composite connections are assumed to be rigid or ... [more ▼]

The present work deals with the load bearing and rotational behaviour of composite connections in steel and concrete constructions. For typical buildings, composite connections are assumed to be rigid or pinned. This assumption can lead to uneconomic structures. A design concept for the estimation of the available rotation capacity, the initial stiffness and the moment bearing capacity of semi-rigid connections is presented. On the basis of the plastic hinge theory diagrams were developed to prove the load carrying capacity and the serviceability of composite beams with semi-rigid connections. The presented design model is based on the evaluation of 9 self conducted tests and on the evaluation of 74 tests on composite connections from all over Europe. The availability of the model was proved by intensive nonlinear finite element simulations. [less ▲]

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