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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Anonymous Opt-Out and Secure Computation in Data Mining

Shepard, Samuel Steven 09 November 2007 (has links)
No description available.
82

Stratagèmes criminels à la jonction des pouvoirs publics et des milieux d’affaires : les élites délinquantes et le processus d’octroi des contrats publics de construction

Reeves-Latour, Maxime 12 1900 (has links)
La thèse a été évaluée par les personnes suivantes: Carlo Morselli, directeur de recherche et professeur à l'École de criminologie; Anthony Amicelle, président du jury et professeur à l'École de criminologie; Jean Bérard, membre du jury et professeur à l'École de criminologie; Carla Nagels, évaluatrice externe et professeur à l'Université libre de Bruxelles L'auteur aimerait remercier le Fonds de recherche du Québec - Société et culture (FRQSC), le Centre international de criminologie comparée (CICC) et l'École de criminologie pour le support financier octroyé à différentes étapes de la rédaction de la thèse. / La recherche trouve ses origines d’un scandale touchant l’industrie de la construction et les milieux politiques au Québec de la fin des années 2000 (à travers les allégations de corruption et de collusion soulevées par les médias) à la fin novembre 2015 (avec le dépôt du rapport final de la Commission d’enquête sur l’octroi et la gestion des contrats publics dans l’industrie de la construction, ci-après CEIC). L’argument principal est que les années de scandale ont permis au Québec de transiter d’une province considérée comme la terre mythique de la corruption au Canada à une entité développant une des structures anticorruptions les plus novatrices et sophistiquées dans le monde. La thèse est construite comme une étude de cas qui s’intègre aux trois grandes sphères de l’étude du phénomène criminel telles que définies par Sutherland et Cressey, à savoir le passage à l’acte, la réaction sociale et le contrôle social (1947, p.1). Dans l’étude du passage à l’acte, le concept de crime étatico-corporatif est mis à profit afin d’exposer l’aspect symbiotique des systèmes criminels alimentés à travers une interaction fondamentale entre poursuite d’intérêts publics et poursuite d’intérêts privés. De tels systèmes furent en effet identifiés dans plusieurs municipalités du Québec. Pour cette partie de la thèse, les données relatives à l’ensemble des contrats de construction octroyés par appel d’offres public par la ville de Laval dans son histoire (1965-2013) sont analysées à travers diverses mesures de réseaux sociaux. Cette portion de la thèse utilise également les témoignages issus des travaux de la CEIC, et des entretiens semi-directifs réalisés avec des acteurs provenant de diverses autorités de lutte à la collusion (truquage des appels d’offres) et à la corruption au Québec. La combinaison de ces méthodes permet d’évaluer la nature intégrée, historique et spatiale des délinquances recensées au sein de diverses municipalités, avec des indicateurs de collusion qui remontent aussi loin qu’à la création de la municipalité lavalloise dans les années 1960. Dans l’étude de la réaction sociale, un modèle d’analyse intégratif emprunté au domaine de la sociologie de l’action publique (Lascoumes et LeGalès, 2012) est utilisé pour mettre en relief les forces structurelles, organisationnelles et individuelles derrière la constitution du scandale québécois. Cette deuxième grande section de la thèse illustre comment ce scandale s’insère dans des tendances nationales et internationales d’intolérance accrue du public et d’intensification des contrôles à l’égard des actes criminels (corruption, collusion, pots-de-vin, fraude) révélés au coeur du scandale. Enfin, dans l’étude du contrôle social, l’analyse des témoignages issus des audiences de la CEIC est jumelée aux données découlant d’entretiens semi-directifs réalisés avec 22 acteurs provenant d’agences de contrôle créées à la suite du scandale : l’Unité permanente anticorruption (UPAC), le Bureau de l’inspecteur général (BIG) de la ville de Montréal, et le Bureau d’intégrité et d’éthique de Laval (BIEL). Cette dernière section illustre comment la transition d’une scène réglementaire permissive et hautement déficiente à un environnement réglementaire axée sur une mobilisation sans précédent de ressources policières, sur le partage d’information et sur la poursuite des conduites illégales au pénal s’avère très avantageuse, mais s’est accomplie – et s’accomplit toujours – à travers de nombreux défis pour les contrôleurs. / The research originated from a political scandal which spanned several years (2009-2015) in the province of Quebec. The thesis’ main argument is that the scandal years saw Quebec transformed from being considered the “historical golden land” of Canadian corruption into a province which developed one of the country’s most sophisticated systems of corruption and white-collar crime control. The thesis was constructed as a case-study, and addressed the three principal objects of criminological analysis: the breaking of laws, the making of laws, and the reaction to the breaking of laws (Sutherland and Cressey, 1947, p.1). The study applied multiple methods to achieve these goals. In the study of criminal decision-making (breaking of laws), Kramer and Michalowski’s (2006) state-corporate crime concept was applied to demonstrate the presence of multifactorial features of criminal systems fuelled by misbehaving at the intersection of private and public interests. Such conspiracies were found to be generalized across several municipalities throughout the province. For this portion of the thesis, data on all construction contracts awarded through public procurement in the entire history of what appeared to be one of Canada’s most corrupt municipalities, Laval (the 13th largest in the country), was systematically collected from 1965 to 2013. It was then analyzed using various social network measures. Testimonies from Quebec’s Commission of inquiry on the awarding and management of public contracts in the construction industry (hereafter, CEIC) were also coupled with a dozen of interviews conducted with regulators and corruption authorities in Quebec. The combination of methods helped assess the integrated, spatial and historical nature of illicit activities which undergirded many municipalities, Laval being one of the most notorious one. Traces of bid-rigging indicators in public procurement were indeed traced back to as early as the city’s founding in the 1960s. In the study of the making of laws, Lascoumes and Le Galès’ (2002) sociology of public action framework was expanded to investigate the structural, organizational, and individual forces behind the Quebec scandal. This section of the thesis unravels the sudden urge to legislate and investigate schemes that were deeply rooted in the province’s history. By making sense of the Quebec scandal, this sub-section demonstrates how larger structural and contextual factors gradually established increased incentives for elected officials to enhance legal and institutional controls on white-collar and corporate crimes which were found to be systemic across Quebec’s construction and political scenes. Finally, in the study of the reaction to the breaking of laws, testimonies from the CEIC were combined with interviews conducted with 22 actors in control agencies established as a direct result of the scandal: the Permanent Anticorruption Unit (UPAC in French), the Inspector General Bureau (BIG in French) of the city of Montreal, and the Bureau of integrity and ethics of Laval (BIEL in French). This last section shows how transitioning from a state of practical passivity to one of intense controls, monitoring, institutional rearrangements, and legislative efforts was accompanied, for regulatory and police authorities, by several benefits but substantial challenges as well.
83

Extracting group relationships within changing software using text analysis

Green, Pamela Dilys January 2013 (has links)
This research looks at identifying and classifying changes in evolving software by making simple textual comparisons between groups of source code files. The two areas investigated are software origin analysis and collusion detection. Textual comparison is attractive because it can be used in the same way for many different programming languages. The research includes the first major study using machine learning techniques in the domain of software origin analysis, which looks at the movement of code in an evolving system. The training set for this study, which focuses on restructured files, is created by analysing 89 software systems. Novel features, which capture abstract patterns in the comparisons between source code files, are used to build models which classify restructured files fromunseen systems with a mean accuracy of over 90%. The unseen code is not only in C, the language of the training set, but also in Java and Python, which helps to demonstrate the language independence of the approach. As well as generating features for the machine learning system, textual comparisons between groups of files are used in other ways throughout the system: in filtering to find potentially restructured files, in ranking the possible destinations of the code moved from the restructured files, and as the basis for a new file comparison tool. This tool helps in the demanding task of manually labelling the training data, is valuable to the end user of the system, and is applicable to other file comparison tasks. These same techniques are used to create a new text-based visualisation for use in collusion detection, and to generate a measure which focuses on the unusual similarity between submissions. This measure helps to overcome problems in detecting collusion in data where files are of uneven size, where there is high incidental similarity or where more than one programming language is used. The visualisation highlights interesting similarities between files, making the task of inspecting the texts easier for the user.
84

Essays in contract theory and industrial organization

Asseyer, Andreas 22 March 2016 (has links)
Diese Dissertation besteht aus drei unabhängigen Kapiteln in Vertragstheorie und Industrieökonomik. Die Kapitel 1 und 2 bearbeiten Fragestellungen der Vertragstheorie. In diesen Kapiteln studiere ich die Ausprägung der Informationsasymmetrien, die in vertraglichen Beziehungen entstehen, wenn die schlechter informierte Partei versucht ihren Informationsnachteil gegenüber dem Vertragspartner zu reduzieren. In Kapitel 1 analysiere ich die Möglichkeit, dass die schlechter informierte Vertragspartei eine dritte Partei – einen Berater oder Supervisor – konsultiert, der jedoch mit der besser informierten Partei kolludieren könnte. In Kapitel 2 analysiere ich den Fall, in dem die schlechter informierte Vertragspartei selbst Monitoring-Aktivitäten aufnehmen kann, um zusätzliche Information zu sammeln. In Kapitel 3 untersuche ich den Effekt von Informationsasymmetrien innerhalb von Unternehmen auf diskriminierende Preissetzungsstrategien in Zwischengutmärkten. Hierbei analysiere ich Preisdiskriminierung und die aus dieser resultierenden Wohlfahrtseffekte in einem Modell eines Zwischengutmarktes, auf dem ein monopolistischer Verkäufer ein Zwischengut an zwei Abnehmer verkauft, die aufgrund ihrer unterschiedlichen vertikalen Organisation unterschiedlich stark von Agenturkosten betroffen sind. / This dissertation consists of three independent chapters in the fields of contract theory and industrial organization. Chapters 1 and 2 are concerned with topics in contract theory. In these chapters, I study the form of information asymmetry that arises in contractual relationships where the less knowledgeable party can reduce its informational disadvantage vis-à-vis the contractual partner. In Chapter 1, I analyze the opportunity of the less knowledgeable party to consult a third party – an expert or supervisor – who can provide advice. In Chapter 2, the less knowledgeable party can itself engage in monitoring activities to gather additional information. In Chapter 3, I explore the effect of information asymmetry within firms on discriminatory pricing in intermediate good markets. In particular, I study price discrimination and the associated welfare effects in an intermediate good market where a monopolistic upstream firms sells an input to downstream firms that vary in their exposure to the problem of asymmetric information due to different degrees of vertical integration.
85

Security and usability of authentication by challenge questions in online examination

Ullah, Abrar January 2017 (has links)
Online examinations are an integral component of many online learning environments and a high-stake process for students, teachers and educational institutions. They are the target of many security threats, including intrusion by hackers and collusion. Collu-sion happens when a student invites a third party to impersonate him/her in an online test, or to abet with the exam questions. This research proposed a profile-based chal-lenge question approach to create and consolidate a student's profile during the learning process, to be used for authentication in the examination process. The pro-posed method was investigated in six research studies using a usability test method and a risk-based security assessment method, in order to investigate usability attributes and security threats. The findings of the studies revealed that text-based questions are prone to usability issues such as ambiguity, syntactic variation, and spelling mistakes. The results of a usability analysis suggested that image-based questions are more usable than text-based questions (p < 0.01). The findings identified that dynamic profile questions are more efficient and effective than text-based and image-based questions (p < 0.01). Since text-based questions are associated with an individual's personal information, they are prone to being shared with impersonators. An increase in the numbers of chal-lenge questions being shared showed a significant linear trend (p < 0.01) and increased the success of an impersonation attack. An increase in the database size decreased the success of an impersonation attack with a significant linear trend (p < 0.01). The security analysis of dynamic profile questions revealed that an impersonation attack was not successful when a student shared credentials using email asynchronously. However, a similar attack was successful when a student and impersonator shared information in real time using mobile phones. The response time in this attack was significantly different when a genuine student responded to his challenge questions (p < 0.01). The security analysis revealed that the use of dynamic profile questions in a proctored exam can influence impersonation and abetting. This view was supported by online programme tutors in a focus group study.
86

Essays in banking

Albertazzi, Ugo 07 September 2011 (has links)
Cette thèse contient trois études sur le fonctionnement des banques.<p>Le premier Chapitre analyse empiriquement comment la capacité d’offrir des emprunts à long terme est influencée par la dimension des intermédiaires financiers.<p>Le deuxième Chapitre analyse, avec un model théorique caractérisé par la présence de soft-budget constraint, ratchet effect et short-termism, comment la pression compétitive influence la capacité des banque de financer le firmes ayant des projets de bonne qualité.<p>Le troisième Chapitre examine, avec un model théorique du type moral hazard common agency, le conflits d'intérêts des banques universelles.<p><p>Financial intermediaries are recognized to promote the efficiency of resource allocation by mitigating problems of incentives, asymmetric information and contract incompleteness. The role played by financial intermediaries is considered so crucial that these institutions have received all over the world the greatest attention of regulators.<p>Across and within banking sectors it is possible to observe a wide variety of intermediaries. Banks may differ in their size, market power and degree of specialization. This variety raises interesting questions about the features of a well functioning banking sector. These questions have inspired an important body of economic literature which, however, is still inconclusive in many aspects. This dissertation includes three studies intending to contribute in this direction.<p>Chapter 1 will empirically study the willingness of smaller and larger lenders to grant long-term loans which, as credit to SME's, constitute an opaque segment of the credit market. Chapter 2 analyzes, with a theoretical model, the effects of competition on the efficiency of the banking sector when this is characterized by dynamic commitment issues which brings to excessive refinancing of bad quality investments (so called soft-budget constraint) or excessive termination of good ones (ratchet effect and short-termism). Chapter 3 presents a model to investigate to what extent the distortions posed by conflicts of interest in universal banks can be addressed through the provision of appropriate incentive schemes by the different categories of clients. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished
87

Hodnota přání dítěte v současné praxi opatrovnických řízení / The value of the Child's Wish in the Contemporary Pracities of the Proceedings Regardiny the Adjustment of Legal Relations towards Minor Children

Böhmová, Tereza January 2019 (has links)
This Diploma Thesis is focused on the issue of the value of a child's wish in the framework of the divorce/break-up settlement. In the theoretical part of this thesis, the child's status, its right to participate and the means of ensuring that in the mentioned framework are presented. In this thesis, the term child's wish is also discussed in the context of defending child's own interest. In the last chapter of the theoretical part, there is illustrated the suitable way how to interview a child. The aim of the practical part is to, through half-structured interviews with the professionals taking part in this process and an analysis of those interviews, answer the main research question: How do the professionals taking part in the divorce/break-up settlement perceive and deal with the child's wish in this process? The research part of this thesis is also focused on the possible space for change in the contemporary attitude towards children as participants of trials.
88

Le besoin de mentir : aspects cliniques et enjeux théoriques / The need to lie : clinical aspects end theoretical issues

Chapellon, Sébastien 08 November 2013 (has links)
Cette recherche s’attache à saisir les logiques inconscientes qui président au besoin de mentir. Elle s’intéresse au type de vulnérabilité psychique que le sujet contre-investit ainsi qu’à la nature de la communication inconsciente qu’il instaure avec ceux qu’il trompe. Après avoir recensé les différentes approches métapsychologiques existantes, les fonctions psychiques du mensonge sont explorées en regard de son rôle au cours du développement de l’enfant. Ensuite, l’examen de cas d’adultes rencontrés dans un dispositif d’accueil pour personnes en errance permet d’expliquer comment les sujets se défendent d’un vécu d’empiètement et le font vivre à ceux qu’ils trompent. Enfin, des exemples d’adolescents, observés dans le contexte de la protection de l’enfance contribuent à l’analyse des dynamiques intersubjectives impulsées par cet acte-parlé. L’ensemble de cette thèse démontre que malgré la difficulté que cette configuration clinique pose à l’observation, sa prise en compte permet de saisir la manière avec laquelle le sujet exprime une souffrance autrement indicible. / This research tries to understand the unconscious logics that preside over the need to lie. It analyses the type of psychological vulnerability a subject counter-invests as well as the origin of the unconscious communication he establishes with those he misleads. After having drawn up an inventory of the existing metapsychological approaches, the author examines the psychological functions of lying by taking into account its role during the development of the child. Then the examination of some adult cases that occurred in a homeless resource center will explain how, some subjects protect themselves from a harassment victim background and have others live the same experience with their lies. Finally, the author examines how cases of teenagers observed within the framework of childhood protection contribute to the analysis of the intersubjective dynamics impulsed by this acte-parlé. This work demonstrates that even though this clinical configuration is difficult to observe, if the psychologist would take it into account, it could help him understand how a patient expresses a pain that he could not tell by other means.
89

Towards Novelty-Resilient AI: Learning in the Open World

Trevor A Bonjour (18423153) 22 April 2024 (has links)
<p dir="ltr">Current artificial intelligence (AI) systems are proficient at tasks in a closed-world setting where the rules are often rigid. However, in real-world applications, the environment is usually open and dynamic. In this work, we investigate the effects of such dynamic environments on AI systems and develop ways to mitigate those effects. Central to our exploration is the concept of \textit{novelties}. Novelties encompass structural changes, unanticipated events, and environmental shifts that can confound traditional AI systems. We categorize novelties based on their representation, anticipation, and impact on agents, laying the groundwork for systematic detection and adaptation strategies. We explore novelties in the context of stochastic games. Decision-making in stochastic games exercises many aspects of the same reasoning capabilities needed by AI agents acting in the real world. A multi-agent stochastic game allows for infinitely many ways to introduce novelty. We propose an extension of the deep reinforcement learning (DRL) paradigm to develop agents that can detect and adapt to novelties in these environments. To address the sample efficiency challenge in DRL, we introduce a hybrid approach that combines fixed-policy methods with traditional DRL techniques, offering enhanced performance in complex decision-making tasks. We present a novel method for detecting anticipated novelties in multi-agent games, leveraging information theory to discern patterns indicative of collusion among players. Finally, we introduce DABLER, a pioneering deep reinforcement learning architecture that dynamically adapts to changing environmental conditions through broad learning approaches and environment recognition. Our findings underscore the importance of developing AI systems equipped to navigate the uncertainties of the open world, offering promising pathways for advancing AI research and application in real-world settings.</p>
90

The exploration of appraising internal controls to detect procurement fraud during the tender stage at mines

Venter, Jan Willem Nicolaas 02 1900 (has links)
Text in English / Procurement fraud is an enormous problem and the South African news is perforated with reports of this illicit act. Procurement fraud occurs in all the phases of the procurement cycle, but this illicit act is mostly committed during the tender phase. Business does not see procurement fraud as a crime and therefor this crime is committed due to non-existent internal controls and processes to assess the adequacy of these controls. The purpose of the research was to highlight that procurement fraud occurs when internal controls are being bypassed or if an entity has an ineffective internal control system. The researcher studied the appraising of internal controls to understand the role it plays in detecting, preventing and investigating procurement fraud, specifically during the tender phase. The research design utilised was a qualitative research approach and an empirical design plan or strategy, to obtain the information. The researcher opted for this design to obtain information from literature and information from individuals in appraising internal controls. This ensured a comprehensive data gathering process. The goal of this research was to provide practical recommendations to assist investigators in private and public sectors with investigations into procurement fraud during a tender. / Police Practice / M. Tech. (Forensic Investigation)

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