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See detailDevelopment and Application of an Asymptotic Level Transport Pollution Model for Luxembourg Energy Air Quality Project
Aleluia Da Silva Reis, Lara UL

Doctoral thesis (2013)

The connections between air pollution and the increase of respiratory diseases, are well known. In Europe, many efforts have been carried out towards the mitigation of the pollutants’ emissions over the ... [more ▼]

The connections between air pollution and the increase of respiratory diseases, are well known. In Europe, many efforts have been carried out towards the mitigation of the pollutants’ emissions over the last decades. The European Union supports the implementation of structural planning measures to control air pollution. The assessment and evaluation of these air quality policies must be carried out with the help of dedicated integrated assessment models. The use of integrated assessment models, which combine models from different fields, raises the need for developing specific modelling concepts in order to provide results to support policy decisions within a practical time frame. This work presents the methodology and the development of a dedicated air quality model for an integrated assessment model. This approach has been designed for the Luxembourg Energy and Air Quality, LEAQ, integrated assessment model. It combines an air quality model, AUSTAL2000-AYLTP, with a techno-economic model, ETEM, which computes ozone precursors emissions related to energy consumption. The models are coupled via an optimization engine, which minimizes the total energy cost for a given ozone level. AUSTAL2000, a Lagrangian transport model, has been adapted to receive a photochemical module, the AsYmptotic Level Transport Pollution, AYLTP. This module consists of a Look-Up Table of quasi-linear reaction rates. A balance has been found that gives an acceptable level of accuracy, given the reduction of computational time. The results of the air quality model have been compared with measurements, and with the regional model LOTOS-EUROS and are considered satisfactory for this type of approach. Regarding the LEAQ framework, two study cases have been simulated, one including only the national emissions from Luxembourg country, and a second one for the Luxembourg region, including the neighbouring countries emissions. [less ▲]

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See detailLa poésie graphique : Christian Dotremont, Roland Giguère, Henri Michaux et Jérôme Peignot
Pelard, Emmanuelle UL

Doctoral thesis (2013)

The purpose of this thesis is to define a type of modern visual poetry (20th – 21st), that we called graphic poetry. The graphic poetry focuses on a plastic and visual experimentation of the graphic sign ... [more ▼]

The purpose of this thesis is to define a type of modern visual poetry (20th – 21st), that we called graphic poetry. The graphic poetry focuses on a plastic and visual experimentation of the graphic sign, demonstrates an important conscience of the visual potential of the written form and tries to produce poetry in the materiality of the writing shapes. This artistic practice of poetry follows and also renews the poetic and plastic avant-gardes of the 20th century, more particularly surrealism. The graphic poetry refers to a practice of poem which is specifically graphic and includes a painting of the sign as a typographic work of the letter in order to produce the poem. The main characteristic of graphic poets is their double vocation : they are writers and visual artists. They experiment writing in its linguistic dimension and its graphic dimension, because they believe that the action of drawing a line or making of a linotype setting — namely the painting or the drawing of the word, of the graphic sign, the typography and the publishing — is already literature. In other words, graphic poets think that the creation and the materialization of the poem proceed of the same gesture. Christian Dotremont’s logograms, Roland Giguère’s artists’ books (Editions Erta) and prints-poems, Henri Michaux’s anthologies of invented painted signs and Jérôme Peignot’s typoems are some forms of graphic poetry. Our study focuses on francophone works, which come from Belgian, French and Quebec fields, published between 1950 and 2004. Three characteristics mainly define the graphic poetry : the ambiguity and the nomadism of the sign in relation to the semiotic systems (graphic, iconic and plastic), graphics rhythm and lyricism, as modalities of the expression of the subject in the graphic material, and a questioning of the distinction between autographic arts and allographic arts, requiring new ways of perception and reading of the poem and the book, that we called visual-reading and touch-reading. [less ▲]

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See detailEuropean Economic Integration through 'fiscality': A legal perspective
Pantazatou, Aikaterini UL

Doctoral thesis (2013)

The present thesis aims to explore the role and the evolution of tax and fiscal integration (and by implication, a central component of economic integration) from a legal perspective. “Integration through ... [more ▼]

The present thesis aims to explore the role and the evolution of tax and fiscal integration (and by implication, a central component of economic integration) from a legal perspective. “Integration through fiscality”, as perceived in this dissertation, comprises two components: direct taxation and fiscal policies (the public finance management of the Member States). The present thesis sets out by pointing to the paradox that, despite their central role in the attainment of an “economic union” without frontiers, “fiscal matters” remain without any solid constitutional framework. After demonstrating the lack of a “constitutional fiscal framework”, the thesis proceeds with a historical account, through the turning points of European Economic integration (Pre- Maastricht, Post-Maastricht and financial crisis). This narrative aims to show the inter institutional struggles among the different actors (the legislator, the Member States, the executive and the judiciary) in their bid to fill this lacuna in the European (Economic) Constitution, through distinct or sometimes parallel ways. To this end, the thesis primarily gives the institutional and constitutional background of ‘fiscality’, while it continues by analysing the different possibilities of integration through ‘fiscality’: a) positive integration through the legislator via hard or soft law means, b) spontaneous integration triggered by regulatory competition and the Member States, c) ‘coordinated’ integration prompted by the Member States, d) negative integration prompted by the CJEU, e) crisis-induced integration outside or within the EU law framework, f) integration by ‘force’, g) integration by exception. The thesis maintains that, notwithstanding the efforts of the CJEU that has risen as the key player pushing for integration in the area of the tax policy, it has been the recent financial crisis which has spurred the other actors towards more integration in the area of fiscal policies with the anticipated domino effects in the direct taxation field. The final part of the thesis attempts, by means of a normative claim, to sketch the salient features of a ‘fiscal Constitution’ for the EU, as part of the ‘new economic governance construction’, that will be both (politically) feasible and compliant with certain standards of legitimacy and the rule of law desiderata. [less ▲]

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See detailPrivacy in RFID and mobile objects
Trujillo Rasua, Rolando UL

Doctoral thesis (2013)

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See detailRelevance marking in lectures: a corpus-based study
Deroey, Katrien UL

Doctoral thesis (2013)

This dissertation by publication contains five articles and six introductory chapters. Deroey & Taverniers (2011) is a general study of the genre and provides an overview of lecture functions based on an ... [more ▼]

This dissertation by publication contains five articles and six introductory chapters. Deroey & Taverniers (2011) is a general study of the genre and provides an overview of lecture functions based on an examination of a lecture subcorpus and a literature study. Deroey (2012) investigates one information highlighting construction, basic wh-clefts, to establish what are the functions of the highlighted discourse and what this reveals about the genre and its disciplinary variation. Deroey & Taverniers (2012a) presents a comprehensive overview of lexicogrammatical markers of important discourse and classifies these into different patterns, while Deroey (submitted) proposes a classification in terms of their interactive and textual orientation. Finally, Deroey & Taverniers (2012b) explores the ways in which lecturers mark less important discourse lexicogrammatically. The six introductory chapters sketch the background to these studies by discussing (1) the lecture genre; (2) relevance marking as a metadiscursive feature; (3) internationalisation and English-medium instruction in higher education; (4) non-native speakers‖ difficulties with English lecture delivery and comprehension; (5) the research rationale; and (6) the lecture corpus. [less ▲]

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See detailNuevas estrategias farmacológicas en el tratamiento de la psoriasis
Andres Ejarque, Rosa Maria UL

Doctoral thesis (2013)

La psoriasis es una enfermedad inflamatoria crónica caracterizada por la inflamación de la piel, que viene acompañada por hiperproliferación de los queratinocitos, infiltración leucocitaria dérmica y una ... [more ▼]

La psoriasis es una enfermedad inflamatoria crónica caracterizada por la inflamación de la piel, que viene acompañada por hiperproliferación de los queratinocitos, infiltración leucocitaria dérmica y una angiogénesis incrementada. Los mecanismos patológicos que dirigen esta patología incluyen tanto respuestas de la inmunidad innata como de la adaptativa. En la presente tesis doctoral se ha ahondado en el estudio de la respuesta fisiopatológica de los queratinocitos a los cambios que se producen en el entorno de una placa psoriásica, con el objetivo de aportar evidencia de relevancia para el desarrollo de nuevos tratamientos farmacológicos. De este modo, se ha puesto de manifiesto que los mediadores proinflamatorios presentes en el contexto psoriásico son capaces de alterar la expresión de los receptores de adenosina, nucleósido implicado en el efecto antiinflamatorio del metotrexato, produciéndose una disminución de los receptores A2B y un aumento de los A2A. Así mismo, se ha demostrado que en piel psoriásica lesional existe una sobreactivación de los transductores de señales y activadores de la transcripción (STAT) 1 y 3, pese a que se produce una disminución mayoritaria de la expresión de las Janus cinasas (Jak). Además, se ha caracterizado el papel de diversos mediadores proinflamatorios en la modulación de estas vías de señalización. Recientemente se ha puesto de manifiesto la importancia de STAT3, así como del factor de transcripción nuclear κB (NF-κB) en la patogénesis de la psoriasis. Por ello, y con el fin de obtener nuevos fármacos útiles para el tratamiento de la enfermedad, en la presente tesis hemos evaluado el potencial efecto antipsoriásico de diversos derivados de origen natural en base a su capacidad para inhibir la activación de estos dos factores de transcripción. Para ello, iniciamos nuestro estudio mediante un screening previo en la línea de macrófagos murinos RAW 264.7 de una serie de moléculas obtenidas en su mayoría de esponjas marinas, así como del condroitín sulfato (CS), proteoglicano de amplio uso en la terapéutica de la osteoartritis. La siguiente fase de nuestro proceso de cribado se realizó en cultivos primarios de queratinocitos humanos, en los que se evaluó la capacidad para inhibir la liberación de las citocinas factor de necrosis tumoral α (TNFα) e interleucina (IL)8. Estos estudios preliminares nos llevaron a la selección del derivado semisintético 4-Benzo[b]tiofen-2-il-3-bromo-5-hidroxi-5H-furan-2-ona (BTH) y del CS para su estudio en profundidad. En la última fase de nuestro estudio, el pretratamiento de queratinocitos primarios humanos con el CS inhibió la activación del NF-κB y, en consecuencia, la liberación de citocinas proinflamatorias. Además, disminuyó la translocación al núcleo de STAT3 así como su actividad transcripcional, demostrando su potencial interés como nuevo fármaco antipsoriásico. Por otro lado, el derivado semisintético BTH también disminuyó la liberación de citocinas y quimiocinas proinflamatorias gracias a su efecto inhibidor de la activación del NF-κB. Además, disminuyó la activación de STAT3 a través del bloqueo de la fosforilación en el residuo de tirosina 705 (Tyr705). Estos resultados fueron confirmados in vivo mediante dos modelos de psoriasis en ratón: la hiperplasia epidérmica inducida por 12-O-tetradecanoilforbol-13-acetato (TPA) y la inflamación psoriásica inducida por imiquimod. En ambos modelos, la administración tópica del BTH previno el desarrollo de lesiones psoriásicas a través de la supresión de la fosforilación del NF-κB y el STAT3, confirmando el potencial de esta molécula como nuevo fármaco antipsoriásico. Globalmente, la presente tesis arroja nueva luz sobre el papel de la adenosina y las vías de señalización del NF-κB y el STAT3 en la patogénesis de la psoriasis y pone de manifiesto la eficacia de moléculas sencillas de origen natural en la paliación de su curso, sugiriendo el potencial interés de estas estrategias farmacológicas en el desarrollo de nuevos abordajes terapéuticos para el tratamiento de esta enfermedad. [less ▲]

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See detailEducational assessment: Two sides of the same coin
Fischbach, Antoine UL

Doctoral thesis (2013)

Detailed reference viewed: 262 (55 UL)
See detailModalities for Access Control: Logics, Proof-Theory and Applications
Genovese, Valerio UL

Doctoral thesis (2012)

Detailed reference viewed: 99 (3 UL)
See detailINACS: An Incremental and Adaptive System to manage Conversational Streams
Poray, Jayanta UL

Doctoral thesis (2012)

Detailed reference viewed: 200 (94 UL)
See detailTrust Dynamics: Beliefs, Preferences, Learning and Performance
Cortesi, Maurizio UL

Doctoral thesis (2012)

Detailed reference viewed: 60 (5 UL)
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See detailSimulation and computer-assisted analysis of actin cytoskeleton dynamics in living cells using fluorescence microscopy methods
Halavatyi, Aliaksandr UL

Doctoral thesis (2012)

Controlled in time and space by a variety of actin-binding proteins, assembly and disassembly of the actin cytoskeleton is involved in many biological and biophysical phenomena. In order to understand the ... [more ▼]

Controlled in time and space by a variety of actin-binding proteins, assembly and disassembly of the actin cytoskeleton is involved in many biological and biophysical phenomena. In order to understand the dynamics of such a complex intracellular system quantitative time-lapse imaging approaches are required. This thesis presents the results of the interdisciplinary project aimed at the quantitative evaluation of the effects of actin-binding proteins on actin turnover under physiological conditions. It combines fluorescence microscopy experiments, development of mathematical models and data processing tools to understand how regulatory proteins control actin dynamics. Confocal-microscopy-based Fluorescence Recovery After Photobleaching (FRAP) technique is a major experimental tool to measure the exchange of actin and actin-binding proteins between polymerised and monomeric pools. The developed models and computational algorithms allow to predict actin dynamics depending on regulatory proteins and to connect the experimental data to parameters characterising polymerisation dynamics, length and structures of actin filaments and activities of tested regulatory proteins. To test the models and to evaluate the activities of actin binding proteins without cellular constrains I combined quantitative FRAP analysis with a biomimetic assay which allows to reproduce major features of actin motility. This combination of techniques was utilised to measure the influence of previously characterised actin-binding proteins working together on actin dynamics in a concentration-dependent manner. In particular we investigated how capping and severing of actin filaments influences actin exchange in a bulk meshwork generated from spatially restricted nucleation. The experimental and analysis methods I developed were also used to investigate the dynamics of the actin cytoskeleton at focal adhesions of living cells. Taking as an example the focal adhesion protein zyxin and its binding partner Tes we addressed how the interactions of these proteins with actin regulate cytoskeleton dynamics. Taken together, the developed approaches and collected data help to better understand how regulatory proteins control actin dynamics in living cells. [less ▲]

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See detailWandel und Differenzierung von Kindheit als Re-Institutionalisierung. Eine Analyse der Reformpolitik zur Kleinkindbetreuung in Luxemburg
Haag, Christian UL

Doctoral thesis (2012)

The thesis focuses on the Luxembourgian social policy and law with regard to early childhood education and care for the last 25 years. Young children are not yet obligated to attend school. The care and ... [more ▼]

The thesis focuses on the Luxembourgian social policy and law with regard to early childhood education and care for the last 25 years. Young children are not yet obligated to attend school. The care and education of these children takes place in day care centres and in the household of child minders as well as in the private sphere of the parents’ home. Policy shapes the care of young children between parents’ home and day care through law and social rights. Along with that, policy implicitly uses ideas of early childhood and mental constructions of how young children grow up. The re-institutionalisation of early childhood is the central approach to analyse these ideas and constructions. In light of the social, cultural and political developments in Europe, especially concerning transformations of family forms and labour markets as well as welfare state change and restructuring, the mental constructions and ideas of early childhood fundamentally change. They become increasingly embedded in rationales in which the care of young children is oriented towards the labour market and the child care market. The qualitative document analysis examines this nexus with reference to the Luxembourgian social policy and law in three continuous phases. The 1990s are dominated by traditional ideas of ‘the young child in domestic care’ in an intimate relationship with the non-working mother. Around the turn of the century, this idea is overlaid by the idea of ‘the young child of working parents’ who is looked after outside the private sphere. Here, the main political rationales are based, not on the situation of young children, but on the occupational and private circumstances of parents and how to support them by means of child care. In the late 2000s, an entirely new idea of early childhood emerges in social policy and law on young children’s care. For the first time, the law strengthens the independent societal status of children and confers the right of care and education to ‘the legally individualised young child’. Paradoxically, these very different constructions of young children and corresponding ideas of early childhood nowadays pertain simultaneously. Therefore, the diversity and multi-layered nature of ideas shapes the contemporary everyday life of young children in Luxembourg. [less ▲]

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See detailL'application du droit européen de la concurrence aux entreprises des Etats tiers
Islentyeva, Ekaterina UL

Doctoral thesis (2012)

The aim of my thesis named “The Application of the European Competition Law to the third countries’ enterprises” was to study the specificity of the application of the EU competition law to the non-EU ... [more ▼]

The aim of my thesis named “The Application of the European Competition Law to the third countries’ enterprises” was to study the specificity of the application of the EU competition law to the non-EU enterprises. In the thesis all the conditions of the application of the EU law to the non-EU enterprise are examined in order to explain how exactly it is happening and what are the consequences, as well as the difficulties in the case of such application (the principle non bis in idem has been examined as well as the possibility of a conflict between the competition law and the intellectual property law and the international private law). However, not only the direct application of the EU competition law is possible. The EU Commission cooperates very actively with the third countries’ antitrust authorities by providing the assistance to the countries developing their Competition policies. Such cooperation between EU and China and between EU and Russia has been analyzed as well as national competition laws of these countries. The final result of the work is the proposal of an International agreement on competition law within the WTO, which contains a new mechanism of cooperation between the states and a formula for calculating and imposing the fines on the enterprises that violate the competition law. [less ▲]

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See detailConceptual Approaches for Securing Networks and Systems
Becker, Sheila UL

Doctoral thesis (2012)

Peer-to-peer real-time communication and media streaming applications optimize their performance by using application-level topology estimation services such as virtual coordinate systems. Virtual ... [more ▼]

Peer-to-peer real-time communication and media streaming applications optimize their performance by using application-level topology estimation services such as virtual coordinate systems. Virtual coordinate systems allow nodes in a peer-to-peer network to accurately predict latency between arbitrary nodes without the need of performing extensive measurements. However, systems that leverage virtual coordinates as supporting building blocks, are prone to attacks conducted by compromised nodes that aim at disrupting, eavesdropping, or mangling with the underlying communications. Recent research proposed techniques to mitigate basic attacks (inflation, deflation, oscillation) considering a single attack strategy model where attackers perform only one type of attack. In this work, we define and use a game theory framework in order to identify the best attack and defense strategies assuming that the attacker is aware of the defense mechanisms. Our approach leverages concepts derived from the Nash equilibrium to model more powerful adversaries. We apply the game theory framework to demonstrate the impact and efficiency of these attack and defense strategies using a well-known virtual coordinate system and real-life Internet data sets. Thereafter, we explore supervised machine learning techniques to mitigate more subtle yet highly effective attacks (frog-boiling, network-partition) that are able to bypass existing defenses. We evaluate our techniques on the Vivaldi system against a more complex attack strategy model, where attackers perform sequences of all known attacks against virtual coordinate systems, using both simulations and Internet deployments. [less ▲]

Detailed reference viewed: 80 (6 UL)
See detailPerformance and Security of Low-Latency Anonymisation Systems
Ries, Thorsten UL

Doctoral thesis (2012)

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See detailFinanzierung des Bildungswesens um 1800 in der Helvetischen Republik. Darstellung verschiedener Akteure sowie deren Einflussfaktoren und Wirkungen auf die wirtschaftliche Grundlage der Schule anhand ausgewählter Gemeinden und Städte in der Helvetischen Republik
Brühwiler, Ingrid UL

Doctoral thesis (2012)

In 1798/99 the Helvetic minister of education Stapfer interrogated all schools of the whole Helvetic Republic with a standardized questionnaire to get around 2400 answers. In my PhD thesis I focus on the ... [more ▼]

In 1798/99 the Helvetic minister of education Stapfer interrogated all schools of the whole Helvetic Republic with a standardized questionnaire to get around 2400 answers. In my PhD thesis I focus on the financial issues of the schools with the Stapfer-inquiry as the main-source; in addition I use different sources of different regional archives. My central question is how the elementary school system was financed at the end of the early modern period (around 1800). This main question leads to five sub-questions. As already in small regional areas different currencies occurred, one has to be selected as key currency. In my thesis it’s the Schaffhauser Batzen. Furthermore the teachers were paid in different wages of kind. All the miscellaneous fragments were standardized. Main results of my thesis are: the financing of schools were affected by the rural or urban areas the school or the teacher belonged to, the political background of the region, organizational structures of the school (like the election mode), economical issues (like the amount of the capital belonging to the school) and social structures. In some regions some factors were more dominant than in others. Additionally: the combination of different factors is varying and influences interact. The following factors were taken into account as well: the age of the teacher, the years of service and the range of subjects he taught. This second set of factors shaped the teachers income as well, but much less as the main parameters. Furthermore it can be demonstrated that the denominational affiliation had no influence to the salaries of the teachers if the main influences are taken into account. [less ▲]

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See detailIn Silico prediction of transcription factor binding sites by probabilistic models
Wienecke-Baldacchino, Anke UL

Doctoral thesis (2012)

The characterization of in silico detected transcription factor binding sites represents a fundamental problem in the field of regulatory gene expression analysis. Several approaches have been proposed to ... [more ▼]

The characterization of in silico detected transcription factor binding sites represents a fundamental problem in the field of regulatory gene expression analysis. Several approaches have been proposed to model DNA-protein-interactions, composed by two main classes: qualitative models considering a consensus sequence and quantitative models providing a measure of binding affinity. The latter can be further subdivided in models assuming an independent contribution of the nucleotides forming a potential binding site and more flexible ones implicating a positional interdependence. In this work the applicability of three probabilistic models to predict transcription factor binding sites has been investigated: (i) the simple position weight matrix (PWM), assuming independence, and two flexible models capturing positional interdependencies represented by a (ii) Chow-Liu Tree and (iii) Ensemble of Trees model. The training and validation of the models on the Mus musculus subset of the UniPROBE database revealed that complex models provide a better predictive power suggesting a high amount of transcription factors binding motifs being affected by positional interdependencies. Additionally, numerous transcription factors were detected, for which the Ensemble of Trees model outperformed both, the Chow-Liu Tree and PWM model. The UniPROBE-based trained models have been applied in a biological context - the prediction of differential binding profiles in five different ChIP-seq samples, followed by the detection of causative regulatory SNPs. The chosen set-up involved family trio data, meaning genotype data from a family composed of father, mother and daughter, providing internal validation. The models provide strong power to correctly classify true negatives in an independent biological sample, represented by a high specificity. The applied approach to detect causative regulatory SNPs, resulted in a candidate list of 20 SNPs. Those gain strong support by epigenetic markers and both, model-based predicted binding affinity of the comprising binding site and significant p-values, describing the effect of the nucleotide exchange. [less ▲]

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See detailIndividual adaptability : validation and application of the concept
Hamtiaux, Armanda UL

Doctoral thesis (2012)

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See detailEtude de propriétés dynamiques linéaires et non-linéaires de deux liquides colloïdaux modèles par rhéologie: DGEBA/Al2O3 et DGEBA/SiO2
Thomassey, Matthieu UL

Doctoral thesis (2012)

The dynamic mechanical behaviors of two model colloidal suspensions are compared in order to highlight microstructural changes in the suspensions. differentiate between the topological and physico ... [more ▼]

The dynamic mechanical behaviors of two model colloidal suspensions are compared in order to highlight microstructural changes in the suspensions. differentiate between the topological and physico-chemical impact of nanoparticles. For both systems the matrix material consists of the technologically relevant epoxy resin diglycidil ether of bisphenol A (DGEBA). The suspended nanoparticles are hydrophilic alumina and hydrophobic silica respectively. It will be shown that beside the classical α process an additional low-frequency relaxator exists whose qualitative frequency behavior is attributed to the pure presence of nanoparticles. The fine structure of the low-frequency relaxator depends on the physico-chemical surface properties of the nanoparticles. Similar to the α process the additional low-frequency relaxator shows cooperative behavior. Astonishingly, on the lines of the pure resin DGEBA, both colloidal suspensions show terminal behavior at very low frequency excitations. The nanoparticles are also shown to be responsible for non-linear dynamic and flow behaviors as well as for the emergence of free surface and volume instabilities. The transient character of flow is induced. [less ▲]

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See detailNumerical Investigation into the Primary Breakup of Liquid Jets and Sheets
Kannan, Kumar UL

Doctoral thesis (2012)

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See detailOpen-world Software: Specification, Verification and Beyond
Bianculli, Domenico UL

Doctoral thesis (2012)

Open-world software systems are built by composing heterogeneous,third-party components, whose behavior and interactions cannot be fully controlled or predicted; moreover, the environment they interact ... [more ▼]

Open-world software systems are built by composing heterogeneous,third-party components, whose behavior and interactions cannot be fully controlled or predicted; moreover, the environment they interact with is characterized by frequent, unexpected, and welcome changes. This class of software exhibits new features that often demand for rethinking and extending the traditional methodologies and the accompanying methods and techniques. In this thesis we deal with a particular class of open- world software, represented by service-based applications (SBAs). We focus on three specific aspects related to the development and provisioning of SBAs: specification, verification, and reputation management. With respect to these aspects, we provide methods and techniques that are i) suitable to deal with aspects such as change, evolution, and reliance on third- parties, and ii) able to improve the overall quality of the systems they are applied to. More specifically, concerning specification, we report on the findings of a study that analyzed requirements specifications of SBAs developed in research settings and in industrial settings. These findings have then driven the design of SOLOIST, a language used to specify the interactions of SBAs. Regarding verification, our contribution is twofold; we propose: i) a technique for automatically generating the behavioral interfaces of the partner services of a service composition, by decomposing the requirements specification of the composite service; ii) a framework for the definition of verification procedures (encoded as synthesis of semantic attributes associated with a grammar) that are made incremental using an approach based on incremental parsing and attributes evaluation techniques. Finally, as for reputation management, we present a reputation-aware service execution infrastructure, which manages the reputation of services used by composite SBAs in an automated and transparent manner. [less ▲]

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See detailGestural Interfaces for Elderly Users - Help or Hindrance?
Stossel, Christian UL

Doctoral thesis (2012)

Detailed reference viewed: 98 (1 UL)
See detailMythe et mémoire. Une relecture du discours jonasien sur Dieu
Borghese, Ester UL

Doctoral thesis (2012)

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See detailProvable Security and Indifferentiability
Mandal, Avradip UL

Doctoral thesis (2012)

In this thesis we consider different problems related to provable security and indifferentiability framework. Ideal primitives such as random oracles, ideal ciphers are theoretical abstractions of ... [more ▼]

In this thesis we consider different problems related to provable security and indifferentiability framework. Ideal primitives such as random oracles, ideal ciphers are theoretical abstractions of cryptographic hash functions and block ciphers respectively. These idealized models help us to argue security guarantee for various cryptographic schemes, for which standard model security proofs are not known. In the first part of this thesis we consider the problems related to ideal primitive construction starting from a different ideal primitive. We adopt the indifferentiability framework proposed by Maurer et. al. in TCC’04 for this purpose. The indifferentiability framework helps us to preserve the security guarantee of cryptographic schemes when the ideal primitives are replaced by indifferentiable constructions, even when the ideal primitives are used in a public manner. At first, we consider the problem of ideal cipher domain extension. We show the 3-round Feistel construction, built using n-bit ideal ciphers are actually indifferentiable from a 2n-bit ideal cipher. We also consider other related issues such as, why 2-round Feistel is not sufficient, security analysis in standard indistinguishability model for both 2 and 3 round constructions, etc. Afterwards, we consider the open problem: whether 6-round Feistel construction using random round functions is indifferentiable from a random invertible permutation or not. We give a partial positive answer to this question. We show the construction is actually publicly-indifferentiable (which is a restricted version of full indifferentiability) from an in- vertible random permutation. In the later part of the thesis, we concentrate on some issues related to the security of Probabilistic Signature Scheme (PSS). PSS with RSA trapdoor is a widely deployed randomized signature scheme. It is known to be secure in Random Oracle model. However, recently randomized signature scheme such as iso/iec 9796-2 is shown to be susceptible to hardware fault attacks. In this work we show, PSS is actually secure against random fault attacks in random oracle model. Afterwards, we consider the openproblem related to standard model security of PSS. We give a general negative result in this direction. We rule out existence of any black box proof technique showing security of PSS in standard model. [less ▲]

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See detailImpact of chromatin organization on the regulation of vitamin D receptor target genes expression in human prostate cells
Zimna, Anna Ewa UL

Doctoral thesis (2012)

Vitamin D Receptor (VDR) belongs to the superfamily of nuclear receptors that are in total 48 ligand-activated transcription factors that bind to the DNA and are involved in the regulation of gene ... [more ▼]

Vitamin D Receptor (VDR) belongs to the superfamily of nuclear receptors that are in total 48 ligand-activated transcription factors that bind to the DNA and are involved in the regulation of gene expression. The active form of vitamin D3, hormone 1α,25-dihydroxyvitaminD3 (1α,25(OH)2D3), is a natural ligand for VDR. The generally described physiological functions of 1α,25(OH)2D3-activated VDR target genes are stimulation of metabolism as well as differentiation and inhibition of inflammation and cellular proliferation. In this study we focus primarily on the target genes of VDR that could potentially have a positive role in cancer prevention. Microarrays were performed of human non-malignant prostate RWPE1 cells after 4 h and 24 h treatment with 100 nM 1α,25(OH)2D3 and among several hundred responsive genes, we identified multiple members of the kallikrein (KLK) gene family as putative primary VDR targets. The KLKs are serine proteases that have been shown to be deregulated in various cancers. The 15 genes in the KLK family cluster together on human chromosome 19 span roughly 270 kB. KLK6 was the most responsive gene (16-fold induction after 4h treatment), followed by its neighboring KLK5, KLK7, KLK8 and KLK9. This effect of 1α,25(OH)2D3 was confirmed by real-time quantitative PCR and loss-of-function experiments. Interestingly, the VDR-mediated induction of the KLK genes was less pronounced in the cancer than in non-malignant prostate cells. In addition, we analyzed the genomic sequence of the KLK cluster in silico and identified a number of putative VDR binding sites (VDREs) as well as putative insulator CTCF binding sites. Chromatin regions containing putative binding sites were analyzed by chromatin immunoprecipitation assays to assess their functionality in RWPE1 cells. Six VDREs were associated with VDR whereas validation of detected CTCF binding sites showed increased occupancy of CTCF upon 1α,25(OH)2D3 stimulation. These results allow describing the changes in chromatin architecture on the KLK locus after VDR activation. Taken together, our study shows that 1α,25(OH)2D3-activated VDR has an impact on the regulation of the whole KLK gene cluster in prostate cells. [less ▲]

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See detailRelations entre maîtres de forges, autorités communales et gouvernementales au Grand-Duché de Luxembourg, de 1850 à 1914 – une étude de cas : Differdange et Dudelange
Kovacs, Stéphanie UL

Doctoral thesis (2012)

Our research relates to the relations between municipalities, ironmasters and central power during the initial phase of the process of industrialisation (1870-1914) and ensuing urban development. This ... [more ▼]

Our research relates to the relations between municipalities, ironmasters and central power during the initial phase of the process of industrialisation (1870-1914) and ensuing urban development. This topic will be studied through a series of questions, to which the archives will try to give answers. The originality of this research lies in the fact that the question of the industrialisation is analysed under aspects which differ from those usually covered by Luxembourgish historiography, especially the impact of municipal finances on the relationship between local authorities and ironmasters. The study concludes that the rhythm of industrialisation of a municipality and the management of related impacts varies according to the degree of interaction between municipal authorities and ironmasters, which depends on a certain number of factors: the state of municipal finances following the settlement of steel factories, the nationality of the leaders of the factories, the weight of employers' paternalism, and finally, the socio-professional composition of the municipal bodies. The study also shows that the governmental authorities are reluctant to intervene in the relationship between municipal bodies and ironmasters, for fear they could offend Luxembourg's main providers of wealth. The study also shows that the government's involvement remains limited to specific cases. [less ▲]

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See detailMean Values and Functional Equations
Dascal, Judita UL

Doctoral thesis (2012)

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See detailLow-energy Secondary Ion Mass Spectrometry: Investigation of buried interfaces in multi-layer organic thin films
Ngo, Khanh Quyen UL

Doctoral thesis (2012)

Recently, the application of conjugated organic compounds increases significantly in optoelectronic devices. The main performances of these devices such as charge and energy transport, operational ... [more ▼]

Recently, the application of conjugated organic compounds increases significantly in optoelectronic devices. The main performances of these devices such as charge and energy transport, operational lifetime and energy conversion efficiency depend strongly on the doping and the interface structure. Therefore, in this project we develop dynamic SIMS analysis conditions using low energy primary ion beam to analyse multi-layered samples used in organic optoelectronic devices. The objective of this thesis is to study the different artefacts and mechanisms, which may arise in the low-energy depth profiling of organic materials and to optimize the SIMS conditions for interface resolution. For the objectives, in chapter I and II, a general introduction about the organic molecules, the fabrication techniques as well as fundamental aspects of the SIMS technique and the analysis conditions are presented. In chapter III, a study of the fragmentation of different organic films during sub-keV bombardment is performed. The typical secondary ions of different organic molecule are identified and chosen for depth profiling. Chapter IV is a study about air-contact induced topography change on Cs+ sputtered surface. This is useful to avoid artefacts when characterizing the Cs+ sputtered surfaces by AFM or by other techniques. The ability of low-energy SIMS to characterize the metal/organics interfaces is investigated in chapter V and VI. Chapter V is about the SIMS depth resolution and sputter-induced surface roughness studied on a series of metal – organic layered samples. In chapter VI, the diffusion of metal into organic layer seen in SIMS depth profiles is characterized. [less ▲]

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See detailThe territorial link as a condition to create a permanent establishment
Schaffner, Jean UL

Doctoral thesis (2012)

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See detailEmpirical Essays on Commodity Prices
Carpantier, Jean-Francois UL

Doctoral thesis (2012)

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See detailHistorische Geographie Phnom Penhs: Stadtentwicklung zwischen Planung und spontaner Ordnung, 1860-2010
Kolnberger, Thomas UL

Doctoral thesis (2012)

This thesis offers an analysis of Phnom Penh`s urban space in the longue durée, examining the concurrence of planning ‘from above’ and spontaneous order ‘from below’. By privileging the spatial point of ... [more ▼]

This thesis offers an analysis of Phnom Penh`s urban space in the longue durée, examining the concurrence of planning ‘from above’ and spontaneous order ‘from below’. By privileging the spatial point of view, the investigation attempts to overcome the false dichotomy of ‘planned’ versus ’unplanned’ order in urban development. Using Phnom Penh as a case-study for city development in a pre-colonial, colonial and post-colonial context, the production of space as a social process is identified in two ways: first ‘literally’ by a historical-critical analysis of the chronological course of urban construction based on archival records and, second, ‘visually’ by scrutinizing master and city plans as well as photographical veduta (i.e. aerial and satellite photography, photos of cityscapes or other relevant urban situations) of past and present. Structure: The thesis consists of five chapters (A-E), organised in three parts (Erster, Zweiter, Dritter Teil). After an introductory chapter (A), dealing with the research topic in general, the first part (chapters B-C) of the investigation follows a morphological approach. It presents the local building and historical town planning traditions of the lower Mekong region in pre-historical times onwards, analysing the pre-colonial times, followed by the French colonial era. The second part (chapter D) deals with the local development during the Cold War, subdivided in two distinct phases: the independence of decolonization (1954-1970s) and the civil war and Khmer Rouge-time (1970s-1989). The third part (chapter E) specifically examines the situation after the fall of the Pol Pot-regime: the ‘new’ independence after the Vietnamese and UN-intervention. The appendix is ex-tensive, but ‘tailor-made’ providing datasheets and detailed background information, e.g. on climate, to allow the interested reader to further deepen some topics. Research questions: Three questions run like a thread through the thesis as recurrent themes: (1) To what extent is the city development a ‘planned’ or ‘unplanned’ process, and which interactions between the two dynamics can be discerned? (2) What power politics from ‘above’ and ‘below’ make up the political economy of space? (3) What kind of continuities and discontinuities can be identified as persistency and change in the cityscape? Social engineering projects ‘from above’ (by diverse governments and power groups) have continuously been challenged, partly evaded and actively counteracted in their own interest ‘from below’ (by the ‘common man’, informal settlers), thus characterizing the social space of Phnom Penh as a ‘common field of action’ (gemeinsamer Aktionsraum). Since colonial times, the physical engineering of space (aligning the urban morphology into a grid-pattern; dividing the city space in [marketable] plots) has been both a transfer from abroad and a quasi-continuity of local proceedings in urban construction. From thispoint of view the transformation of the royal residence-town into a colonial city and the subsequent change from a colonial administration centre of lesser importance within the French Indochinese Union to a dominant capital city of an independent state are revealing a complex pattern of competing interests of all ‘spatial’ actors: rich and poor, mighty and weak, officials and individuals, military and civilian, singles and families. Attempts of social engineering by the use of the built environment and the imple-mentation of physical change to it, however, have also been producing ‘frictions’ (Friktionen) ever since. As result, a third degree of order, besides the intended and non-intended, has emerged: epiphenomena (Epiphänomene; Phänomene der dritten Art). The self-organisation through the ‘auto-agglomeration’ of businesses during the resettlement process after the fall of the Khmer Rouge is examined as an example for this kind of spatial (re)ordering. Concluding the longue durée-analysis of Phnom Penh, the spatial distribution is analysed and presented in full detail as economy of espionage and imitation in chapter (E). Methodology: In order to achieve the primary object of this undertaking to write a historical geography of the production of Phnom Penh’s space, a multidisciplinary approach was necessary, combining historical-critical analysis (Historisch-kritische Methode); geography (spatial analysis, urban morphology) and sociology (questionnaires and interviews, ‘observing participation’). The very heterogeneous mixture of archival sources and newly generated data that informs this study required a reflexive grounded theory. [less ▲]

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See detailDependency of network traffic monitoring
Wang, Shaonan UL

Doctoral thesis (2012)

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See detailSecurity and Network monitoring based on Internet flow measurements
Wagner, Cynthia UL

Doctoral thesis (2012)

Today's networks face continuously arising new threats, making analysis of network data for the detection of anomalies in current operational networks essential. Network operators have to deal with the ... [more ▼]

Today's networks face continuously arising new threats, making analysis of network data for the detection of anomalies in current operational networks essential. Network operators have to deal with the analysis of huge volumes of data. To counter this main issue, dealing with IP flows (also known as Netflows) records is common in network management. However in modern networks, even Netflow records still represent a high volume of data. Interest in traffic classification as well as attack and anomaly detection in network monitoring and security related activities has become very strong. This thesis addresses the topic of Netflow record analysis by introducing simple mechanisms for the evaluation of large quantities of data. The mechanisms are based on spatially aggregated Netflow records. These records are evaluated by the use of a kernel function. This similarity function analyses aggregated data on quantitative and topological pattern changes. By the use of machine learning techniques the aim is to use the aggregated data and classify it into benign traffic and anomalies. Besides the detection of anomalies in network traffic, traffic is analyzed from the perspective of an attacker and a network operator by using a game-theoretical model in order to define strategies for attack and defence. To extend the evaluation models, information from the application layer has been analyzed. An occurring problem with application flows is that in some cases, network flows cannot be clearly attributed to sessions or users, as for example in anonymous overlay networks. A model for the attribution of flows to sessions or users has been defined and related to this, the behaviour of attack and defence mechanisms is studied in the framework of a game. [less ▲]

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See detailSensor Fusion Combining 3-D and 2-D for Depth Data Enhancement
Garcia Becerro, Frederic UL

Doctoral thesis (2012)

Time-of-Flight (ToF) cameras are known to be cost-efficient 3-D sensing systems capable of providing full scene depth information at a high frame rate. Among many other advantages, ToF cameras are able to ... [more ▼]

Time-of-Flight (ToF) cameras are known to be cost-efficient 3-D sensing systems capable of providing full scene depth information at a high frame rate. Among many other advantages, ToF cameras are able to provide distance information regardless of the illumination conditions and with no texture dependency, which makes them very suitable for computer vision and robotic applications where reliable distance measurements are required. However, the resolution of the given depth maps is far below the resolution given by standard 2-D video cameras which, indeed, restricts the use of ToF cameras in real applications such as those for safety and surveillance. In this thesis, we therefore investigate how to enhance the resolution of ToF data and how to reduce the noise level within distance measurements. To that end, we propose to combine 2-D and ToF data using a low-level data fusion approach that enhances the low-resolution depth maps up to the same resolution as their corresponding 2-D images. [less ▲]

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See detailPhoto-Hall measurements on CuInSe2
Altenhofer, Georg UL

Doctoral thesis (2012)

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See detailAssessment of implicit and explicit algorithms in numerical simulation of granular matter
Samiei, Kasra UL

Doctoral thesis (2012)

The objectives of this dissertation are to investigate and demonstrate the potentials of implicit integration methods in predicting the dynamics of granular media and to describe the granular dynamics on ... [more ▼]

The objectives of this dissertation are to investigate and demonstrate the potentials of implicit integration methods in predicting the dynamics of granular media and to describe the granular dynamics on forward and backward acting grates by discrete element method. Traditionally, explicit integration methods are employed within the context of Discrete Element Method. Generally, explicit equations are simpler to solve than the implicit ones but they require a small time step to be utilized. In this study, an implicit Numerov integration scheme is employed to integrate the equations of motion. The implicit method is verified in different test cases starting from simple cases to more complicated cases including hundreds of particles. Comparing the results with the results of the explicit method, it is shown that the implicit method exhibits a distinguished advantage only at very large time steps. Taking into account the overhead of solving non-linear equations at each time step, it is concluded that implicit methods are computationally too expensive for their limited gains. Addressing the second objective of this study, the residence time distribution of granular particles on forward and backward acting grates are numerically predicted. Very good agreement between the predictions and the available experimental results is achieved. It can be concluded that the Discrete Element Method is highly capable of predicting the dynamics of solid fuel particles on grate systems. Future work shall include coupling of the method with computational fluid dynamics in order to account for thermal conversion of the fuel particles. [less ▲]

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See detailJudgement aggregation for multiagent systems
Slavkovik, Marija UL

Doctoral thesis (2012)

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See detailInvestment Fund Governance: An empirical investigation of Luxembourg UCITS
Hazenberg, Jan UL

Doctoral thesis (2012)

Investment funds potentially suffer from the conflict of interest between investors and fund management companies. Fund boards could help mitigate this conflict. In Luxembourg, the second largest fund ... [more ▼]

Investment funds potentially suffer from the conflict of interest between investors and fund management companies. Fund boards could help mitigate this conflict. In Luxembourg, the second largest fund domicile globally, fund boards are not required to have independent board members. Nevertheless, many firms have independent board members on their fund boards. The research question investigated is whether or not boards with (more) independent board members are more effective for investors, leading to lower costs (Total Expense Ratio) and/or better investment performance (Carhart alpha). With a multiple regression analysis, the relationship is analysed of the level of fund costs and performance with the funds’ governance characteristics, controlling for various other promoter, umbrella and fund variables. This approach did not provide consistent evidence that independent governance contributes to lower costs or better performance. The survey among board members showed that irrespective of whether or not the boards have independent board members, fund boards in the sample prioritise risk management and compliance aspects. Lower priority is given to investment performance and costs. Both for the level of costs and performance, whether or not the promoter had affiliated distribution in the group seems to be a more important driver than the composition of the fund board. [less ▲]

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See detailKesterite Equilibrium Reaction and the Discrimination of Secondary Phases from Cu2ZnSnS4
Berg, Dominik UL

Doctoral thesis (2012)

Kesterite (Cu2ZnSnS4 - CZTS) based thin films are of increasing interest in the field of thin film photovoltaics. In recent developments, mixed S-Se kesterite devices have shown power conversion ... [more ▼]

Kesterite (Cu2ZnSnS4 - CZTS) based thin films are of increasing interest in the field of thin film photovoltaics. In recent developments, mixed S-Se kesterite devices have shown power conversion efficiencies of more than 10 %, but yet a major challenge is the fabrication of single phase kesterite material for high quality solar cells. In this thesis, two aspects of the growth of single phase kesterite films have been studied in more detail. The first part focuses on the identification of secondary phases (e.g. ZnS and Cu2SnS3) and their discrimination from CZTS. Hereby, grazing incidence X-ray diffraction and Raman spectroscopy measurements were used to quantitatively identify secondary phases on a mixed, CZTS containing sample. Experimental results show, that in a measurement series a minimum of 7 % of ZnS or 28 % of Cu2SnS3 must be present in order to be identifiable. The second part of this thesis focuses on finding a way to grow absorber layers for high quality CZTS thin film solar cells. Hereby, it could be shown that it is important for the quality of the absorber layer to keep the equilibrium position of the formation reaction of CZTS close to the CZTS side throughout the annealing. To achieve this, it is suggested to anneal the precursors in the presence of sulfur and tin sulfide. A study showed that this novel annealing strategy helped to improve the power conversion efficiency of a device based on a vapor-deposited precursor from 0 % to 6.1 %. Within this context, a novel route to form CZTS from a simplified, only Cu and Zn containing precursor, has been introduced and a model of the formation reaction of CZTS from this simplified precursor has been suggested. [less ▲]

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See detailCuInSe2 thin film solar cells synthesised from electrodeposited binary selenide precursors
Fischer, Johannes UL

Doctoral thesis (2012)

The box must contain a summary in a maximum of 1,700 characters, spaces included. The fabrication of a CuInSe2 thin film solar cell from an electrodeposited precursor stack consisting of indium selenide ... [more ▼]

The box must contain a summary in a maximum of 1,700 characters, spaces included. The fabrication of a CuInSe2 thin film solar cell from an electrodeposited precursor stack consisting of indium selenide and copper selenide layers is demonstrated. A best conversion efficiency of 5.5% was achieved, a higher efficiency than previously reported in literature. The thesis focuses on three main parts: (i) electrochemistry of indium selenide: The incorporation of indium in the deposit requires the presence of selenium species. The obtained film consists of both amorphous In2Se3 and elemental Se. The Se/In ratio depends on the applied potential, although the deposition is mass transport controlled limited by the selenium ion concentration. The potential controls the balance of reduction kinetics between the In2Se3 and elemental Se and both compete for the same intermediate selenium species. (ii) phase reactions during annealing: The small interface area between the electrodeposited indium selenide and the copper selenide layer slows down the interdiffusion during the annealing process. Therefore the temperature required to react the precursor is higher than reported for similar stacks in literature. Copper selenide is retained at the surface for a longer time during the annealing process, where it undergoes the transitions CuSe2 => CuSe => Cu2Se. (iii) loss mechanisms in the solar cell: The highest solar cell conversion efficiency was obtained from a stoichiometric precursor compromising the advantages and disadvantages of Cu-poor and Cu-rich growth. The Cu-poor grown absorber showed a reverse pn-junction at the backside due to an incomplete reaction of the stack. The efficiency of the Cu-rich grown solar cell was limited by high interface recombination. [less ▲]

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See detailContribution à la résolution de la conjecture S-adique
Leroy, Julien UL

Doctoral thesis (2012)

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See detailSocial network analysis over dynamic graphs and application to urban mobile ad hoc networks
Herbiet, Guillaume-Jean UL

Doctoral thesis (2012)

Wireless mobile ad hoc networks (MANET) are composed of mobile communicating devices that self-organize to ubiquitously exchange information over the air. Envisioned applications for such networks cover ... [more ▼]

Wireless mobile ad hoc networks (MANET) are composed of mobile communicating devices that self-organize to ubiquitously exchange information over the air. Envisioned applications for such networks cover disaster relief situations, battlefield deployment and more generally any use-case that makes the deployment of wired or infrastructure-based networks too costly or simply unsuitable. Lately, new applications for MANETs are developing in the urban environment, namely mobile social networks and vehicular ad hoc networks. Despite this large spectrum of possible applications and the large number of wireless-capable devices available today, mobile ad hoc networks remain confidential. One important reason is the lack of reliability of wireless communications, especially on long path. In this thesis, we propose to cope with this problem by creating virtual structures that will group together limited set of users that are densely and reliably connected in order to favor the dynamic and robust exchange of information. Our proposal uses the concept of community, that first appeared in social network analysis. After reviewing the main concepts taken from this branch of graph theory and justifying the application by underlining the specificities of MANETs in the urban context, we formally present our contribution, based on epidemic propagation of community labels. Then we exhibit its applications on concrete communication systems and how it can benefit more generally to improve the management of wireless ad hoc networks topology. [less ▲]

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See detailBuild Operate and Transfer (BOT) Projects - Contribution à l’étude juridique d’une modalité de partenariat public-privé à la lumière de l'approche Law and Economics
Tatofie, Roger UL

Doctoral thesis (2012)

Infrastructures and utility services are fundamental to economic and human development. Therefore, investment in these areas is critical to economic growth, quality of life, poverty reduction, access to ... [more ▼]

Infrastructures and utility services are fundamental to economic and human development. Therefore, investment in these areas is critical to economic growth, quality of life, poverty reduction, access to education and health care and achieving many of the objectives of a robust economy. Yet, whereas the public sector provides the vast majority of financing for infrastructure services, investments have not matched demand, public funds or borrowings are insufficient and governments are seeking methods to improve the efficient procurement of infrastructure services. Private sector participation in public projects is increasingly becoming a reliable source of investment and, as far as public policies are concerned, an unavoidable feature of our contemporary society even in “core public policies” (for example, greater responsibility for financial planning and welfare provision is being increasingly shifted by the states to the private sector and individuals). In the area of infrastructures and utility services, Public-Private Partnerships (PPP), despite some of their challenging features, are one of the tools in a policy maker’s arsenal which help to increase investment in infrastructure services and improve its efficiency. One of the main advantages of PPP is that, unlike privatization, the government retains strategic control over the project and the ownership of its assets. PPP offers multiple options or structures. As shown in this study, Build, Operate and Transfer (BOT) Projects are one of the numerous options offered by PPP. In a BOT project, a private entity is given the right to design, finance, build and operate for a defined period (“concession period”) a facility that would normally be built by the government. The operation of the project generates revenues and the private entity uses these revenues to service debt and provide the investors with a return. At the end of the defined period, the private entity turns over the facility to the government. In practice, a number of parties - each with sometimes different interests, levels of sophistication and available resources - will be involved in a BOT project: the grantor/host government, the sponsors (generally throughout the project company), the lenders and the contractors (construction contractor, operator, offtake purchaser, input supplier) and the BOT approach can be used for different and various projects (power generation, water treatment, airports, roads, tunnels, bridges…) and, hence, has many variants such as BOO (Build, Own and Operate), BOOT (Build, Own, Operate and Transfer), BTO (Build, Transfer and Operate) etc. The BOT approach is not, however, a panacea for the host government and may involve some disadvantages. In effect, BOT projects are highly complex (from both financial and legal points of view), commercially driven projects, requiring extensive documentation and negotiation and a suitable political, legal, regulatory and economic environment. Nevertheless, it has many potential advantages and still is a viable alternative in most countries to the more traditional approach to public projects. For policy makers, practitioners, investors and, above all, the targeted populations to fully benefit from these advantages, the BOT concept must however be clarified and lifted from the fuzziness in which it has been plunged by commentators. There has actually been a dual view of the BOT concept: On one hand, some commentators consider the BOT concept as a simple public procurement modality, comparable to the concession model, and hence to be subjected to classical public law concepts, practices and requirements such as the public services, public ownership and standards and rules of public budget and accountancy. On the other hand, some other commentators view the BOT concept as a modality of project financing which should therefore be subjected to the requirements of profitability and risks sharing. However, if this dual view presents the BOT concept under two specialized lenses and tends to protect certain interests - i.e. public interests and private interests - it is in fact non satisfactory conceptually as well as practically. In fact, this dual view describes a unique reality which an economic cooperation characterized by harmony and conflict, change and equilibrium. The ambition and objective of this study is therefore to give a full understanding of the BOT concept and to shed light on its originality and its unity. The BOT concept is therefore considered as an economic cooperation device, demonstration made in this study principally under the light of law and economics approach. In effect, structuring a BOT project requires the use of (free) market tools (especially economic and financial tools), which render the law and economic approach perfectly suitable to analyze the BOT concept and reveal its rationality and coherence. Hence, the use of the (strategic) game theory to underline the mutual gains resulting from the cooperation between partners involved in a BOT project; the use of the incomplete contract theory to explain the special care needed to design the BOT contract and its possible adjustments; the use of the theory of the firm and financial contracting to explain the functions of coordination and integration of the project company; or also the use of the public choice theory to analyze the notion of general interest which has led to the conclusion that BOT projects are a combination of public and private interests in order to achieve optimality and mutual gains. More generally however, this study has adopted a pragmatic view, using various and different methods, because analyzing the relationships between State and market requires taking into account a great range of fields, considerations and expertise. This pragmatic approach suggested the study be carried out as a genealogic enterprise, such a process allowing a criticizing stance and a formulation of a new and global theoretical frame presenting the relics and the transformations of the current (dual) views of the BOT concept from which its originality and its unity derive. This study has therefore shown that the contractual, structural, economic and financial interdependence of the BOT project makes it an undeniable economic cooperation device. The BOT concept therefore acquires a conceptual unity which reinforces its functional and practical nature and adds a guarantee of legal security to its use. Besides, it has also been demonstrated that BOT is a signaling and an accountability tool for the partners involved in those operations. Ultimately, as regard to public projects, the BOT concept introduces a bit of rationality in equity and humanity to efficiency. [less ▲]

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See detailSuccess and well-being of young persons in Switzerland
Samuel, Robin UL

Doctoral thesis (2012)

Detailed reference viewed: 137 (12 UL)
See detailDesign and Modeling of Privacy-Friendly Reputation
Schiffner, Stefan UL

Doctoral thesis (2012)

Detailed reference viewed: 47 (2 UL)
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See detailViral regulation of nutrient assimilation by algae and prokaryotes
Sheik, Abdul UL

Doctoral thesis (2012)

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See detailSociality and Self-Organisation in Next-Generation Distributed Environments
Botev, Jean UL

Doctoral thesis (2011)

The proliferation of computationally powerful, interconnected devices entails a new generation of networked applications and social utilities characterized by a strong growth in scale and dynamics.<br ... [more ▼]

The proliferation of computationally powerful, interconnected devices entails a new generation of networked applications and social utilities characterized by a strong growth in scale and dynamics.<br />Distributed virtual environments constitute a privileged example, involving a high degree of interactivity as well as tightened constraints and requirements. As a response to these issues, this dissertation explores and substantiates sociality as a fundamental principle both in and for the design of such systems.<br />A specialized, dual peer-to-peer architecture is introduced, combining a highly-structured backbone overlay with a loosely-structured geometric client overlay synergistically complementing each other. To enable a global-scale, single-instanced environment, it is imperative to include as many client-side resources as possible and unburden the backbone. The focus of this dissertation therefore lies upon the latter, geometric overlay.<br />By taking an interdisciplinary perspective and leveraging different aspects of sociality, a series of self-organized approaches addressing major problem areas are proposed: a collaborative filtering mechanism for the handling of information overload created from the soaring amounts of users and objects; a confidentiality framework for the protection of sensitive data more likely exposed due to an increased interactivity; and two resource allocation schemes for fairly distributing surplus capacities in the face of critical regional surges.<br />Detailed evaluations show that these decentralized algorithms operate robustly and effectively, while yielding well-converging results in comparison to optimal, global-knowledge scenarios. [less ▲]

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See detailThe reading and mathematics performance of language-minority children in Luxembourg, Serbia and Europe: Is school instruction in their mother tongue important?
Aleksic, Gabrijela UL

Doctoral thesis (2011)

In order to explore the complex reality of the importance of mother tongue for the reading and mathematics performance of language-minority children, I conducted three studies. The aims of the studies ... [more ▼]

In order to explore the complex reality of the importance of mother tongue for the reading and mathematics performance of language-minority children, I conducted three studies. The aims of the studies were threefold: a) to investigate the reading and mathematics performance of language-minority preschool children in Luxembourg and Serbia (Study I). b) to identify predictors for early reading performance in the majority language (Study II). c) to conduct a meta-analysis on the effectiveness of bilingual as opposed to submersion programs in promoting the academic achievement of language-minority children (Study III). All three studies were theoretically anchored in the psycholinguistic constructs of Jim Cummins, as in OECD (2006, 2010) results reporting the underachievement of minority students in Europe. On the strength of this theory and drawing from empirical evidence, I propose three hypotheses: a) Hypothesis 1: language-minority children will score significantly lower in both reading and mathematics than language-majority children (Study I). b) Hypothesis 2: the significant predictors for early reading will be whether the test was conducted in the child’s mother tongue or not, the child’s gender, the level of education of the child’s parents, the child’s range of vocabulary, the child’s phonological awareness, competence in mathematics and the child’s behaviour (Study II). c) Hypothesis 3: bilingual education programs that include language-minority children’s mother tongue in school instruction are superior to submersion programs that exclude the children’s mother tongue in school instruction in promoting their academic achievement (Study III). International data show that those language-minority students who do not speak the school language of instruction at home are, on average, one year behind their native peers (Stanat & Christensen, 2007). This gap hampers student’s academic achievement, which in turn restrict the student’s opportunities in the labour market. The purpose of Study I was, therefore, to investigate the performance in reading and mathematics of language-minority preschool children in Luxembourg (N=174) and Serbia (N=159). MANOVA results showed that in Luxembourg, Portuguese children performed significantly lower than both native Luxembourgish children and other minority children. However, with regard to the testing of vocabulary and rhyming words - sections of the test which are evidently loaded with Luxembourgish-specific words - Portuguese and other minority children scored significantly lower than Luxembourgish children. I speculate that language of instruction can be one of the reasons for their possible low performance. In Serbia, Roma performed significantly lower than Hungarians, Serbs and other minority children. This finding may suggest that there are other variables, such as the socio-economic backgrounds of the children that may contribute to the low performance of both the Portuguese and Roma as language-minority groups at school. Thus, Hypothesis 1 is partly confirmed. Reading skills provide a crucial foundation for children’s success at school (Lonigan, Burgess, & Anthony, 2000) and beyond (Miles & Stipek, 2006). Good progress in reading and mathematics in the earliest years constitute the most important factors which continue to play a role at the age of 11 (Tymms, Jones, Albone, & Henderson, 2007). Study II, involving preschool children from Serbia (N=159) and Luxembourg (N=174), examines the predictive value of the child’s gender, the child’s mother tongue, the level of education of the child’s parents, the child’s range of vocabulary, the child’s phonological awareness, competence in mathematics and the child’s behaviour for early reading skills. For the Serbian sample, multilevel models showed that whether the test was administered in the child’s mother tongue at the age of 5 or not and competence in mathematics were the most significant predictors for early reading at the age of 7 after controlling for age, gender, vocabulary, phonics and behaviour. For the Luxembourgish sample, gender, vocabulary, phonological awareness and competence in mathematics at the age of 5 were significant predictors for reading at the same age, after controlling for age and the mother tongue. The level of parental education in the Serbian sample and the children’s behaviour in both samples proved not to be significant. Thus, Hypothesis 2 is partly confirmed. The education of language-minority children becomes increasingly important in today’s society. Five previous meta-analyses investigated the effectiveness of bilingual programs in promoting academic achievement of language-minority children in the United States. The present meta-analysis (Study III) investigates seven European studies on the topic. Results indicate a small positive effect (g=0.23) for bilingual over submersion programs on the academic achievement of language-minority children (also see Rolstad, Mahoney & Glass, 2005, 2008). This meta-analysis, therefore, appears to support bilingual education in Europe, the education that includes the mother tongue of language-minority children in the school instruction. Thus, Hypothesis 3 is confirmed. However, the results are restricted due to the small number of studies. More published studies in bilingual education in Europe are needed. [less ▲]

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See detailAnalysis of resynchronization mechanisms of stream ciphers
Priemuth-Schmid, Deike UL

Doctoral thesis (2011)

Stream ciphers are cryptographic primitives belonging to symmetric key cryptography to ensure data confidentiality of messages sent through an insecure communication channel. This thesis presents attacks ... [more ▼]

Stream ciphers are cryptographic primitives belonging to symmetric key cryptography to ensure data confidentiality of messages sent through an insecure communication channel. This thesis presents attacks on several stream ciphers, especially against their initialization methods. The first targets are the stream ciphers Salsa20 and Trivium. For both ciphers slid pairs are described. Salsa20 can be distinguished from a random function using only the slid pair relation. When a slid pair is given for Salsa20 both secret keys can be recovered immediately if the nonces and counters are known. Also an efficient search for a hidden slid pair in a large list of ciphertexts is shown. The efficiency of the birthday attack can be increased twice using slid pairs. For the cipher Trivium a large related-key class which produces identical keystreams up to a shift is presented. Then the resynchronization mechanism of the stream ciphers SNOW 3G and SNOW 2.0 is analyzed. Both ciphers are simplified by replacing all additions modulo 32 with XORs. A known IV key-recovery attack is presented for SNOW 3G and SNOW 2.0 where both ciphers have no feedback from the FSM. This attack works for any amount of initialization clocks. Then in both ciphers the feedback from the FSM is restored and the number of 33 initialization clocks is reduced. Chosen IV key-recovery attacks on SNOW 3G with 12 to 16 initialization clocks and SNOW 2.0 with 12 to 18 initialization clocks are shown. In a similar way versions of the stream cipher K2 are attacked. This cipher is simplified by replacing all additions modulo 32 with XORs as well. Chosen IV key-recovery attacks on versions with reduced initialization clocks from five to seven out of 24 are presented. For the version with seven initialization clocks also a chosen IV distinguishing attack is shown. The last part deals with a linear key-IV setup and known feedback polynomials of the shrinking generator. It is shown that this linear initialization results in a very weak cipher as only a few known IVs are required to recover the secret key. The original design of the shrinking generator does not include any initialization method so the initial state was assumed to be the secret key. [less ▲]

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See detailAn Alternative approach to extreme-risk management
Laube, Falk UL

Doctoral thesis (2011)

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See detailDe Bonn à Berlin : territoires, mémoires et échelles du politique
Laporte, Antoine UL

Doctoral thesis (2011)

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See detailInhomogeneities of epitaxial chalcopyrites studied by photoluminescence
Larsen, Jes K. UL

Doctoral thesis (2011)

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See detailLipid and Immune Functions of the Liver X Receptors in Human Macrophages
Diwo, Janine UL

Doctoral thesis (2011)

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See detailParallel hybrid optimization methods for permutation based problems
Mehdi, Malika UL

Doctoral thesis (2011)

Solving efficiently large benchmarks of NP-hard permutation-based problems requires the development of hybrid methods combining different classes of optimization algorithms. The key challenge here is how ... [more ▼]

Solving efficiently large benchmarks of NP-hard permutation-based problems requires the development of hybrid methods combining different classes of optimization algorithms. The key challenge here is how to find connections between the divergent search strategies used in each class of methods in order to build efficient hybridization strategies. Genetic algorithms (GAs) are very popular population-based metaheuristics based on stochastic evolutionary operators. The hybridization of GAs with tree-based exact methods such as Branch-and-Bound is a promising research trend. B&B algorithms are based on an implicit enumeration of the solution space represented as a tree. Our hybridization approach consists in providing a common solution and search space coding and associated search operators enabling an efficient cooperation between the two methods. The tree-based representation of the solution space is traditionally used in B&B algorithms to enumerate the solutions of the problem at hand. In this thesis, this special representation is adapted to metaheuristics. The encoding of permutations as natural numbers, which refer to their lexicographic enumeration in the tree, is proposed as a new way to represent the solution space of permutation problems in metaheuristics. Mapping functions between the two representations and special search operators are defined for general permutation problems. This common representation allows the design of efficient cooperation strategies between GAs and B&B algorithms. The proposed hybrid schemes have been parallelized and validated on standard benchmarks of the 3D quadratic assignment problem (Q3AP) using the computational grid Grid5000. [less ▲]

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