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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.
1

Defining Risk Assessment Confidence Levels For Use In Project Management Communications

Johnson, Gary 01 January 2008 (has links)
A review of the literature regarding risk management and effective risk communications identified that very few researchers have addressed risk assessment confidence levels when using risk scoring methods. The focus of this research is to develop a definition of risk assessment confidence levels for use in internal project management communications and to evaluate its usefulness. This research defines risk assessment confidence level as "The degree of certainty that the likelihood or consequence score (assigned by the risk assessor) reflects reality." A specific level of confidence is defined based on the types of analyses that were conducted to determine the risk score. A survey method was used to obtain data from a representative sample of risk assessment professionals from industry and academia to measure their opinion on the usefulness of the defined risk assessment confidence levels. The survey consisted of seven questions related to usefulness--four questions addressed the importance of stating confidence levels in risk assessments and three addressed the usableness of the proposed confidence level. Data were collected on the role and experience level of each of the respondents and the survey also included a comment section to obtain additional feedback. The survey generated 364 respondents representing a broad variety of roles associated with decision making and risk management with experience levels from fairly new to experienced risk assessors. The survey data were analyzed by calculating the proportion of respondents who gave negative, neutral and positive responses to the survey questions. An examination of the roles of the survey respondents indicated that no single group was dominant. A non-parametric Kruskal-Wallis test generally failed to reject the hypothesis that the means of the survey response distributions were identical. There was one exception which indicated that there are differences based on role and by inspection of the responses, it appears that decision makers, academics, and others more strongly support the need for confidence level information to reduce the difficulty in making risk based decisions in projects. The survey responses at a confidence level of 95% have a range of errors from 3.84 to 4.97%. Based on the results of the survey, 77 - 83% of those surveyed indicated agreement that knowing the confidence the assessors have in their assessment is important and would improve a management decision. The survey showed that 60 - 86% of the respondents agreed that the confidence levels and their definitions as presented in the survey were usable. The question with the lowest agreement (60%) was related to the way in which the individual levels were defined. The ad-hoc comments provided in the survey were divided into eleven groups based on similarity of the subject of the comment and then examined for common themes. These added additional insight into the results and useful information for future research efforts. This research validates that the use of risk assessment confidence levels is considered to be useful in project risk management. The research also identified several potential areas for future work, including determining the appropriate number of confidence levels that should be defined, refining the definition of the individual confidence level definitions, examining historical perspectives of whether the risk assessments were accurate, examining the concept of shiftability of risk assessments, further research on communication of variability of risk assessments, and research into the usefulness of risk matrices.
2

Study of WW decay of a Higgs boson with the ALEPH and CMS detectors

Delaere, Christophe 06 July 2005 (has links)
The Standard Model is a mathematical description of the very nature of elementary particles and their interactions, now seen as relativistic quantum fields. A key feature of the theory is the Brout-Englert-Higgs mechanism, responsible for the spontaneous symmetry breaking of the underlying gauge symmetry, and which implies the existence of a neutral Higgs particle. Searches for the Higgs boson were conducted at the Large Electron Positron collider until 2000 and are still ongoing at the Tevatron collider, but the particle has not been not observed. In order to better constrain models with an exotic electroweak symmetry breaking sector, a search for a Higgs boson decaying into a W pair is carried out with the ALEPH detector on 453 pb-1 of data collected at center-of-mass energies up to 209 GeV. The analysis is optimized for the many topologies resulting from the six-fermion final state. A lower limit at 105.8 GeV/c² on the Higgs boson mass in a fermiophobic Higgs boson scenario is obtained. The ultimate machine for the Higgs boson discovery is the Large Hadron Collider, which is being built at CERN. In order to evaluate the physics potential of the CMS detector, the WH associated production of a Higgs boson decaying into a W pair is studied. Performances of data acquisition and its sophisticated trigger system, particle identification and event reconstruction are investigated by performing a detailed analysis on simulated data. Three-lepton final states are shown to provide interesting possibilities. For an integrated luminosity of 100 fb-1, a potential signal significance of more than 5ó is obtained in the mass interval between 155 and 178 GeV/c². The corresponding precision on the Higgs boson mass and partial decay width into W pairs are evaluated. This channel also provides one of the very few possible avenues towards the discovery of a fermiophobic Higgs boson below 180 GeV/c². These studies required many original technical developments, that are also presented.
3

Study of WW decay of a Higgs boson with the ALEPH and CMS detectors

Delaere, Christophe 06 July 2005 (has links)
The Standard Model is a mathematical description of the very nature of elementary particles and their interactions, now seen as relativistic quantum fields. A key feature of the theory is the Brout-Englert-Higgs mechanism, responsible for the spontaneous symmetry breaking of the underlying gauge symmetry, and which implies the existence of a neutral Higgs particle. Searches for the Higgs boson were conducted at the Large Electron Positron collider until 2000 and are still ongoing at the Tevatron collider, but the particle has not been not observed. In order to better constrain models with an exotic electroweak symmetry breaking sector, a search for a Higgs boson decaying into a W pair is carried out with the ALEPH detector on 453 pb-1 of data collected at center-of-mass energies up to 209 GeV. The analysis is optimized for the many topologies resulting from the six-fermion final state. A lower limit at 105.8 GeV/c² on the Higgs boson mass in a fermiophobic Higgs boson scenario is obtained. The ultimate machine for the Higgs boson discovery is the Large Hadron Collider, which is being built at CERN. In order to evaluate the physics potential of the CMS detector, the WH associated production of a Higgs boson decaying into a W pair is studied. Performances of data acquisition and its sophisticated trigger system, particle identification and event reconstruction are investigated by performing a detailed analysis on simulated data. Three-lepton final states are shown to provide interesting possibilities. For an integrated luminosity of 100 fb-1, a potential signal significance of more than 5ó is obtained in the mass interval between 155 and 178 GeV/c². The corresponding precision on the Higgs boson mass and partial decay width into W pairs are evaluated. This channel also provides one of the very few possible avenues towards the discovery of a fermiophobic Higgs boson below 180 GeV/c². These studies required many original technical developments, that are also presented.
4

Understanding the behaviour of  IOCs during their lifecycle

Godavarti, Navya sree, Modali, Sivani January 2022 (has links)
An indicator of compromise is a digital artefact that detects data compromise. They sense the compromise happening, trace the intrusion and collect data. This data includes breached data and the address. All indicators have a limited period of a lifetime, in which these work the best time in their peak. Once the indicator starts decaying, then its performance of it deteriorates. Meaning there is an increase in false alarms of compromise. The most influential parameters in the performance of an IOC are related pulse, alerts, file score and IDS. These parameters influence both the working and decay of an indicator. But the relation between these is unknown; therefore, this thesis investigates the nature of the correlation between these parameters. Evaluating an IOC and its performance or decay is essential as these determine the quality of an indicator known as confidence in cybersecurity. In cybersecurity management, confidence (quality) is crucial in preventing or detecting threats. By understanding IOC's performance and decay, we can determine its confidence level. There has been a model generated to find confidence levels, and this thesis aims to improve those models. Here, the thesis proposes a case study to find the relation between parameters and use the findings in making an improved model finding confidence level.
5

Exploration de la régulation stratégique lors de la récupération mnésique et du potentiel mnésique de l’évaluation lors de l’apprentissage : implications pour la compréhension des troubles de la mémoire dans la schizophrénie / Strategic regulation in memory reporting and the mnemonic potential of judgements-of-learning : implication in the understanding of memory disturbances in schizophrenia

Akdogan, Elçin 22 September 2014 (has links)
La schizophrénie s’accompagne de troubles de mémoire limitant les possibilités d’insertion socio-professionnelle des patients en souffrant. La métamémoire concerne un savoir sur son propre savoir. L’objectif de cette thèse était d’explorer les théories et méthodes de la métamémoire pour y rechercher des possibilités d’améliorer les performances de mémoire des patients souffrant de schizophrénie. Dans un protocole prenant en compte les aspects de contrôle personnel lors de la récupération mnésique, nous avons montré que les patients peuvent atteindre des performances de mémoire comparables à celles des témoins lorsqu’ils sont guidés par les processus de la métamémoire (évaluation et contrôle), alors que leurs performances spontanées étaient déficitaires. Notre étude pilote portant sur l’exploration du potentiel mnésique du jugement d’apprentissage métamnésique a produit des résultats prometteurs. Cette stratégie semble être plus efficace que la stratégie la plus habituellement utilisée malgré sa faible efficacité, celle consistant à réapprendre les items. Nos résultats permettent d’entrevoir l’utilité de mémoire dans la schizophrénie. / Schizophrenia is accompanied by a wide range of cognitive difficulties which highly limit social and professional integration of patients suffering from it. Metamemory can be referred as knowledge about its own knowledge. The aim of this thesis was to explore theories and methods of metamemory which could be relevant in improving patients’ memory performances. In a study devoted to study personal control over memory reporting, our results have shown that patients can achieve comparable memory performances as control subjects while guided through metamemory processes (monitoring and control), where as their performance were spontaneously deficient. Our pilot study exploring the mnemonic potential of metamemory judgment of learning generated promising results. This strategy seems to be more efficient than the most commonly implemented but not very efficient learning strategy, relearning of to be learned items. Our results allow us to presume the utility of metamemory to enhance memory performances in schizophrenia.
6

Enhanced Prediction of Network Attacks Using Incomplete Data

Arthur, Jacob D. 01 January 2017 (has links)
For years, intrusion detection has been considered a key component of many organizations’ network defense capabilities. Although a number of approaches to intrusion detection have been tried, few have been capable of providing security personnel responsible for the protection of a network with sufficient information to make adjustments and respond to attacks in real-time. Because intrusion detection systems rarely have complete information, false negatives and false positives are extremely common, and thus valuable resources are wasted responding to irrelevant events. In order to provide better actionable information for security personnel, a mechanism for quantifying the confidence level in predictions is needed. This work presents an approach which seeks to combine a primary prediction model with a novel secondary confidence level model which provides a measurement of the confidence in a given attack prediction being made. The ability to accurately identify an attack and quantify the confidence level in the prediction could serve as the basis for a new generation of intrusion detection devices, devices that provide earlier and better alerts for administrators and allow more proactive response to events as they are occurring.
7

Generation of a full-envelope hydrodynamic database for hydrobatic AUVs : Combining numerical, semi-empirical methods to calculate AUV hydrodynamic coefficients

Miao, Tianlei January 2019 (has links)
The next generation of Autonomous Underwater Vehicles (AUV) can impact our observation of the world. The flight simulation and full-envelope hydrodynamics modeling can improve the performance of AUVs in terms of control, navigation and positioning. In order to achieve agile maneuverability, a more accurate database of full-envelope hydrodynamic coefficients is supposed to be generated. Two semi-empirical methods, Jorgensen and DATCOM, and two numerical method, Computational Fluid Dynamics (CFD) and XFLR5 are used to push the boundaries of hydrodynamic coefficients: lift, drag and moment coefficients for flight-style AUVs at the Swedish Maritime Robotics Center (SMaRC). A comparison of different approaches and tools, and an analysis of the most appropriate approaches for different regions of a defined maneuver has been conducted in this thesis. A data confidence level was proposed as a way to estimate the accuracy of the data and a structured database was built in terms of data confidence level. Different components of the AUV such as the hull body and wings were analyzed separately. The new database is input to a 3DOF Simulink model and the 6DOF SMaRC hydrobatics simulator for flight dynamics simulations. Simulations show that the new database has a good applicability.
8

Constructing confidence regions for the locations of putative trait loci using data from affected sib-pair designs

Papachristou, Charalampos 24 August 2005 (has links)
No description available.
9

Approche probabiliste pour l'estimation dynamique de la confiance accordée à un équipement de production : vers une contribution au diagnostic de services des SED / A probabilistic approach to dynamically estimate the confidence for production equipments : Contribution to the diagnosis of discrete event systems services.

Duong, Quoc Bao 19 December 2012 (has links)
Le travail que nous présentons dans ce mémoire apporte sa contribution au domaine dela surveillance et de la supervision en ligne des systèmes à événements discrets complexes.Il se place dans un contexte perturbé par l’occurrence d’aléas de fonctionnement d’une partieopérative au sein duquel nous visons à mettre à disposition des équipes de maintenance desoutils pour les aider à localiser rapidement les équipements à l’origine probable de défautsproduits : localiser mieux pour maintenir mieux et donc minimiser encore davantage les tempsde dérives équipements. Si les équipements de production étaient en mesure de détecterde telles dérives, le problème pourrait être considéré comme simple, cependant, la présenced’équipements de métrologie montre le contraire. Aussi, partant du constat que les équipementsde production ne peuvent être dotés d’un système de captage couvrant de manière exhaustivel’ensemble des paramètres à observer, que la fiabilité des capteurs est variable dans le temps,que les contextes de production sont particulièrement stressants, nous avons proposé ici dedévelopper une approche probabiliste basée sur un raisonnement Bayésien permettant d’estimeren temps réel la confiance qui peut être accordée aux opérations réalisées par les équipementsde production. / The work that we present in this paper contributes to the field of supervision, monitoringand control of complex discrete event systems services. It is placed in the context of randomfailure occurrence of operative parts where we focus on providing tools to maintenance teamsby locating the possible origin of potential defect products: better locate to better maintain, soeffectively to minimize more equipment’s time drift. If the production equipment were able todetect such drifts, the problem could be considered simple; however, metrology equipment addsto the complexity. In addition, because of an impossibility to equip the production equipment witha sensor system which comprehensively covers all parameters to be observed, a variable sensorreliability in time and a stressed production environments, we propose a probabilistic approachbased on Bayesian network to estimate real time confidence, which can be used for productionequipment?s operation.
10

Conscience du temps, sentiment de passage du temps : une approche métacognitive de la perception du temps / Awareness of time, feeling of time passage : a metacognitive approach of time perception

Lamotte, Mathilde 07 April 2016 (has links)
La métacognition concerne à la fois les connaissances des individus sur leur fonctionnement cognitif et les processus qui permettent de les réguler (Koriat, 2007). Or, l’étude de la perception du temps a mis en évidence que de nombreux éléments peuvent provoquer des distorsions temporelles, notamment, par exemple, l’attention ou les feedbacks. L’objectif de ce travail est donc de proposer un modèle intégratif de la métacognition de la perception du temps ; autrement dit d’intégrer les données issues des recherches classiques sur la perception du temps au sein d’un modèle métacognitif (Nelson et Narens, 1990).Notre première question était de vérifier l’existence de connaissances sur la perception du temps, et en particulier sur les facteurs à l’origine de distorsions temporelles. Les 3 expériences de notre première étude nous ont conduit à créer et valider le Questionnaire Métacognitif sur le Temps (MQT). Ce dernier, constitué de 24 items, met en évidence l’existence de connaissances plus fiables pour soi (sous-échelle Soi, 12 items) que pour autrui (sous-échelle Autrui, 12 items), sur deux facteurs connus pour affecter la perception du temps : le facteur Emotion (4 items) et le facteur Attention (8 items).Dans un deuxième temps, nous avons étudié l’influence des processus métacognitifs sur les jugements temporels. Ainsi, nous nous sommes intéressées à l’influence du processus de Contrôle métacognitif sur la performance à deux tâches temporelles. Notre hypothèse était que les connaissances sur le temps permettaient de réguler les jugements temporels. Les résultats de nos deux études (Etude 2 et 3, respectivement composées de une et deux expériences) ont confirmé l’importance du processus de Contrôle dans le jugement temporel. Ainsi, la simple conscience du rôle de l’attention sur la perception du temps provoque une réduction de l’effet attentionnel généralement observé (Etude 2). De plus, les connaissances explicites, erronées, données aux individus, provoquent une réduction voire une disparition de l’effet émotionnel automatique de la colère sur les jugements temporels (Etude 3). Enfin, nous avons exploré le lien entre processus de Monitoring et jugements temporels. Notre quatrième étude a mis en évidence la capacité des individus à estimer précisément la justesse de leurs jugements temporels sous certaines conditions. En effet, il apparaît que les individus sont sensibles à la difficulté de la tâche et à la gamme de durée. Ces deux dimensions affectent à la fois les jugements temporels et les jugements de certitude.Dans l’ensemble, les résultats de ce travail soulignent l’importance qu’il y a à tenir compte des processus métacognitifs dans l’étude de la perception du temps. / Metacognition concerns both individuals' knowledge about their cognitive functioning and the processes that regulate them (Koriat, 2007). The study of the perception of time showed that many factors cause temporal distortions, including, for example, attention or feedback. The purpose of this work is thus to propose an integrative model of metacognition of time perception; i.e. to integrate data based on conventional research on the perception of time in a metacognitive model (Nelson and Narens 1990).Our first question was to verify the existence of knowledge about the perception of time, especially on the factors responsible for temporal distortions. The three experiments of our first study led us to create and validate the Metacognitive Questionnaire on Time (MQT). The latter consists of 24 items that highlights the existence of knowledge, more reliable for oneself (subscale Self, 12 items) than for others (subscale Others, 12 items), on two factors known to affect time perception: an Emotion Factor (4 items) and an Attention factor (8 items).Secondly, we studied the influence of metacognitive processes on temporal judgments. Thus, we are interested in the influence of metacognitive Control process on performances in two temporal tasks. Our hypothesis was that knowledge about time allowed regulating the temporal judgments. The results of our studies (Study 2 and 3, respectively composed of one and two experiments) confirmed the importance of the Control process on temporal judgments. Thus, mere awareness of the role of attention on perception of time causes a reduction of the attentional effect generally observed (Study 2). Moreover, explicit erroneous knowledge given to participants causes a reduction or even disappearance of automatic emotional effect of anger on the temporal judgments (Study 3). Finally, we have explored the link between Monitoring process and temporal judgments. Our fourth study demonstrated the ability of individuals to accurately estimate the accuracy of their temporal judgments under certain conditions. Indeed, it appears that individuals are sensitive to task difficulty and duration range. These two dimensions affect both temporal judgments and confidence level estimates.Overall, the results of this study emphasize the importance to take account of metacognitive processes in the study of the perception of time.

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