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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.
291

Dynamique des communautés biologiques dans un contexte de restauration par injection sédimentaire et érosion maitrisée : cas du Vieux Rhin, France / Dynamics of biological communities in a context of restoration by gravel augmentation and controlled erosion : the case of the Old Rhine River, France

Staentzel, Cybill 25 April 2018 (has links)
Le Rhin a subi d’importantes modifications qui ont altéré la biodiversité de l’ensemble de la plaine alluviale. Des actions de restauration ont été initiées pour lui redonner une part de son fonctionnement hydromorphologique naturel. Le travail de thèse a consisté à évaluer les effets de ces restaurations et à mettre en évidence les processus mis en jeu dans les changements de la biocénose des milieux restaurés. Les résultats ont démontré que les communautés biologiques sont non seulement gouvernées par les modifications physiques post-restauration mais aussi par l’influence discrète de déterminants externes à la restauration tels que les invasions biologiques ou la dynamique interne du fleuve. L’aspect transitoire des bénéfices obtenus a été souligné comme la principale limite de l’injection sédimentaire alors que les épis transversaux artificiels mis en place dans le cadre d’un essai d’érosion maitrisée se sont révélés être les facteurs de durabilité des effets écologiques. / The Rhine River has undergone major engineering works that led to severe alterations which helped to alter the biodiversity of the entire floodplain. Restoration actions have been initiated to give it back a part of its natural hydro morphological functioning. The thesis consisted in evaluating the effects of these restorations and in highlighting the mechanisms and processes involved in biocoenosis changes of the restored environments. The results also showed that the post-restoration biological community is not only defined by post-restoration physical changes but also by the discrete influence of external determinants of restoration such as biological invasions or the internal dynamics of the river. The transitional aspect of the benefits incurred has been identified as the main limit of the gravel augmentation, while the implementation of transverse artificial groynes in the controlled bank erosion has proved to be factors of sustainability of the ecological effects.
292

Characterisation and host-parasite interaction of the piscine diplomonad Spironucleus salmonis

Fard, Mohammad Reza Saghari 11 December 2008 (has links)
Durch Parasiten stellen eine starke Gefährdung für die Aquakultur dar. Die durch diplomonaden Flagellaten bei der Regenbogenforelle Oncorhynchus mykiss verursachte Morbidität und Mortalität wurde bisher in Deutschland noch nicht gründlich untersucht. Ich habe diese Parasiten mittels SEM & TEM charakterisiert und wurde die Art Spironucleus salmonis bestimmt. Erstmals konnten die caudale Projektion, sich entleerende Vakuolen und verformbare Kernloben nachgewiesen werden. Ich untersuchte Mikrohabitatpräferenz von des Parasiten sowie pH-Profile in vier Darmabschnitten der Fische. Das Vorkommen und die Dichte von S. salmonis war in der Pylorusregion wesentlich höher als in anderen Bereichen. Das pH-Profil war bei infizierten und nicht infizierten Fischen gleich. Der optimale pH-Wert für S. salmonis war 7,1-7,5. Ich habe die Lebenszyklus der Diplomonaden mittels LM & SEM unter Kulturbedingungen untersucht. Die Enzystierung begann mit der Anheftung von Trophozoiten mit der Spitze der adhäsiven hinteren Flagellen aneinander oder an Fremdkörper. Die pyriformen Trophozoiten wurden kugelförmig, und die vorderen Flagellen inaktiv. Oberflächenbläschen produzierten eine lichtbrechende Zystenwand. Dies ist der erste Beschreibung der Multifunktionalität von Flagellen bei Diplomonaden. Ich untersuchte pathogene Mechanismen und sezierte die Pylorusregion sowie die Leber mittels H&E, PAS/AB. Bei infizierten Fischen trat eine signifikante Hypertrophie der Becherzellen auf. Zu erkennen war eine Hyperaktivität der Becherzellen, jedoch keine Hyperplasie. Ich entwickelte einen in vitro  Plasma-Inkubationstest zur Bestimmung der Suszeptibilität von Regenbogenforelle, Karpfen und Störe. Die unterschiedliche Resistenz von Stör, Karpfen und Regenbogenforelle gegen S. salmonis entsprechend zu den epizootiologischen Daten. Meine Untersuchungen führten zu einem neuen diagnostischen Hilfsmittel, Vorschlägen für neue Behandlungsmethoden, zu verbesserten in vitro-Kulturbedingungen und einem Modellsystem für die Multifunktionalität von Flagellen und flagellaren Signaltransduktion. / Parasitic diseases pose a significant threat to aquaculture. Diplomonad flagellates in rainbow trout Oncorhynchus mykiss are associated with morbidity and mortality; but in Germany has not been thoroughly studied. I characterised the species by SEM & TEM, which revealed Spironucleus salmonis, allowed its complete description including newly showing the caudal projection, discharging vacuoles, and deformable nuclear lobes; diagnostic keys were improved. The microhabitat preference of diplomonads was tested by recording occurrence and density of infection, and pH profile in 4 intestinal regions in fish. Occurrence and density of S. salmonis were significant higher in the pyloric region than elsewhere. The pH profile in uninfected and infected fish was similar; a causal relationship between microhabitat preference and pH was unlikely, and the optimal pH was between 7.1 – 7.5. I described life cycle and encystment using light and SEM. Encystment in culture began by trophozoites attaching at tip of adhesive posterior flagella to each other/debris. Pyriform trophozoites became sub-spherical, anterior flagella inactive, surface blebs produced a refractile cyst wall. Cysts clusters may exceed minimum infective dose for new infection; suggesting new treatment target. This is the first report of multi-functionality of flagella in diplomonads. I investigated pathogenic mechanism of diplomonads by sectioning and staining the pyloric region of the intestine and liver with H&E, and PAS/AB. There was significant hypertrophy of goblet cells in infected fish. The hyperactivity of goblet cells was seen, but no hyperplasia. This hyper-production of mucus may decrease nutrient absorption, underlying impaired growth in S. salmonis infected fish. I developed an in vitro plasma incubation test to predict host susceptibility of rainbow trout, carp, and sturgeon. The test showed the hierarchy of resistance of S. salmonis in sturgeon > carp > rainbow trout; this parallels epizootiological data. My research yielded new diagnostic tool, suggested new treatment target, improved in vitro conditions, and new model system for multi-functionality of flagella and flagellar signalling.
293

Place brand efficiency : resident, manager and tourist perceptions of the region brand / L’efficacité de la marque territoire : perceptions d'une marque région par les habitants, les managers et les touristes

Martin, Emeline 11 September 2017 (has links)
Dans un contexte de mondialisation, la concurrence accrue entre les territoires, dont l’objectif premier est de capter des habitants, des touristes et des entreprises, exacerbe les enjeux liés à leur attractivité. Afin de se différencier les collectivités territoriales et leurs agences de développement adoptent des approches de marketing territorial et commencent à mettre en place des techniques de marquage (dites place branding). Le place branding reprend plusieurs outils issus du domaine de la marque commerciale. Toutefois, le territoire est un « produit particulier » qui regroupe diverses parties prenantes dont les visions et les attentes peuvent diverger. Le succès d’une marque territoire reposera alors en partie sur la gestion de ces parties prenantes. Dès lors, ce travail doctoral entreprend d’adapter au contexte du place branding des concepts de marketing, en considérant les perceptions de trois groupes de parties prenantes, en vue d’améliorer l’efficacité de la marque territoire. Cette problématique de recherche est abordée selon trois questions de recherche: (1) Quelle est la légitimité publicitaire d’une marque territoire, telle que perçue par ses habitants ? Influence-t-elle l’efficacité des actions de place branding ? (2) Dans quelle mesure les gestionnaires de marques territoires ont recours à des stratégies de marketing communautaire afin d’implémenter une communication marketing intégrée (CMI) ? (3) Dans quelle mesure l’image de la marque région constitue-t-elle un vecteur pertinent de la promotion d’une destination, complémentaire à celle de la marque pays, auprès des touristes internationaux ? D’un point de vue théorique, cette recherche doctorale souligne l’importance d’adopter une approche parties prenantes à la compréhension de la marque territoire. Ce faisant, ce travail contribue à développer des preuves empiriques dans le domaine, notamment à l’échelle de la région qui est sous-représentée dans la littérature. Cette thèse met en évidence les similitudes entre la marque territoire et la marque commerciale, et renforce ainsi la validité externe de trois concepts issus du marketing classique. Différentes approches méthodologiques ont été développées et mobilisées. Ces éléments renforcent par ailleurs la validité interne de la présente recherche et contribuent à exclure l’existence d’un biais déclaratif. Les contributions managériales de cette thèse sont liées à ses implications méthodologiques dans la mesure où diverses grilles d’analyse sont proposées aux gestionnaires de marques territoires. Ces outils prennent en compte les spécificités et les enjeux associés aux principales parties prenantes de la marque, et visent à les impliquer dans les initiatives de place branding. Enfin, la mise en place d’une approche de communication marketing intégrée est conseillée. Premièrement, il est proposé que cette approche soit appliquée entre les différents acteurs du territoire. Les résultats montrent ainsi que l’intégration des habitants dans la démarche de place branding est un véritable enjeu qui nécessite une approche distincte de celle préconisée traditionnellement en marketing. Deuxièmement, l’approche de communication marketing intégrée devrait s’appliquer entre les différents niveaux de territoires de façon à tirer parti de l’image du territoire d’ordre supérieur. / In the globalized world, Nowhere, Place, is directly competing against Powerful, World, to attract residents, tourists and talent, as well as firms and investments, whether the place is a meta-region, a country, a region, a city or other locations. Whilst places and destinations around the world have been proclaiming their qualities for a long time, mainly to create awareness or maintain preference, those marketing communications campaigns are short-term and don’t contribute to unifying the place. To compete in such cutthroat environments, public authorities and place agencies have started to recognize the value of adopting branding techniques by way of practising place branding. Place branding adapts several tools developed in the field of commercial branding to contribute to place development and establish image-building strategies that render places more attractive to identified markets. As such, this doctoral work endeavours to adapt mainstream marketing concepts to the context of place branding, taking into account the views of three groups of stakeholders to enhance place brand efficiency. I address these research questions in a French region-branding context, according to three sub-questions that summarise the chapters of this thesis. First, what is the advertising legitimacy of a place brand as perceived by the residents? Does it influence place-branding efficiency? Second, to what extent do place brand managers use community marketing strategies to operationalize the integrated marketing communications (IMC) role of the place brand? Third, to what extent does the region brand image constitute a relevant vehicle for promoting a destination integral to the nation brand image, as perceived by international tourists? Results show that the representational and functional dimensions of a destination brand impact differently implicit attractiveness and intentions to visit. International tourists also perceive the region and the nation brand images as congruent overall, which contributes positively to their intentions to visit the region. From a theoretical point of view, this research highlights the importance of adopting a multi-stakeholder approach to understanding place branding. Doing so contributes to the development of empirical evidence in the domain, by studying the understudied region branding form. This dissertation also highlights similarities with commercial branding and reinforces the external validity of three classic marketing concepts. The methodological implications of this work come from the different methodological approaches (i.e. measurement tools and methods), developed to meet the specificities and stakes associated with the main stakeholders of a place brand. In addition, this approach reinforces the internal validity of the present research and contributes to ruling out the existence of a declarative bias. The managerial contributions of this thesis are connected with the methodological implications, inasmuch as it provides place brand managers with diverse analysis grids that will enable them to take into account the specificities and stakes associated with the main stakeholders of the place brand, and also involve stakeholders in the place-branding process. Finally, I demonstrate the need for an IMC approach that is per se—for example, through the use of an overall brand positioning that covers shared elements between stakeholders so that they all relate to the place brand, or through the adoption of a bottom-up rather than top-down approach to place branding. This approach also should be able to extend to other place scales, by leveraging the image of a higher-order place.
294

Funcionalidade e função executiva em idosos saudáveis e portadores de demência na doença de Alzheimer: estudo de validação do Executive Function Performance Test-Br / Funcionality and Executive Function in helthy and carriers of dementia in Alzheimer\'s disease elderlies: validation study of the Executive Function Performance Test - Br

Neubern, Patricia Cardoso Buchain 20 March 2018 (has links)
Introdução: Na Doença de Alzheimer, o comprometimento no desempenho nas Atividades de Vida Diária (AVD) impacta diretamente a autonomia e independência do indivíduo. A capacidade funcional determina o nível de auxílio que uma pessoa irá necessitar no cotidiano para uma vida em segurança e com autonomia. Dentre os domínios cognitivos, a Função Executiva tem sido relatada como a mais associada com o desempenho de funcionalidade. Há a necessidade de instrumentos válidos para avaliar os déficits das funções executivas no desempenho de tarefas de mundo real em pacientes com doença de Alzheimer (DA) no Brasil. Objetivo: Validar a versão brasileira do teste Executive Performance Test (EFPT) em pacientes com doença de Alzheimer (DA). Métodos: Adaptação cultural do EFPT para o português do Brasil. Os estudos de confiabilidade e validade foram realizados com três grupos de idosos: controles, DA leve e DA moderada. Este estudo examinou a estabilidade do instrumento, a consistência interna (alfa de Cronbach), a validade de constructo e de critério e análises de precisão. Resultados: A amostra foi composta de 83 participantes com 60 anos ou mais, distribuídos em três grupos: controle, DA leve e DA moderada. A confiabilidade inter examinadores foi alta (ICC = 0,985), com alta consistência interna (Cronbach ? = 0,967). Houve forte correlação entre EFPT-Br Total e DAFS-BR (r = -0.762), correlação fraca a moderada com a bateria cognitiva e correlação moderada a forte com a bateria funcional. Foi realizado o cálculo da da ROC multiclasse área sob a curva de 0,8933, a pontuação sugerida para diferenciar os grupos : menor que 8 para controles; entre 9 e 27 para DA leve; e acima de 28 para DA moderada, para discriminar grupos. Conclusão: O EFPT-BR é um teste válido, com parâmetros psicométricos satisfatórios, para discriminar pacientes saudáveis, com DA leve e DA moderada na realização de tarefas instrumentais. O teste fornece informações consistentes para auxiliar a compreensão do desempenho de pacientes com DA na realização de atividades de vida diária com mais autonomia e segurança / Background: In Alzheimer\'s disease, the impairment in performing Activities of Daily Life (ADL) directly affects the autonomy and independence of the individual. The functionality determine a person needs for a safe and autonomous life. Among the cognitive domains, Executive Function has been reported as the most associated with functionality performance. There is a need for valid assessments to evaluate the deficits of executive functions in performing of real world tasks with patients with Alzheimer\'s disease (AD) in Brazil. Objective: To validate to Brazilian Portuguese version of the Executive Function Performance Test (EFPT) in Alzheimer disease (AD) patients. Methods: Cultural adaptation of EFPT to Brazilian Portuguese. The reliability and validity studies were performed with three groups of elderly: controls, mild AD and moderate AD. This study examines instrument stability, an internal consistency (Cronbach\'s alpha), a construct and criterion validity, and precision analyzes. Results: The sample consisted of 83 participants aged 60 years and over, divided into three groups: control, mild AD and moderate AD. The inter-examiner reliability was high (ICC = 0.985), with high internal consistency (Cronbach ? = 0.967). There was a strong correlation between EFPT-Br Total and DAFS-BR (r = -0.762), weak to moderate correlation with a cognitive battery and moderate to strong correlation with the functional battery. We performed the calculation of the ROC multiclass area under the curve of 0.8933, a score suggested to differentiate the groups: less than 8 for controls; between 9 and 27 for mild AD; and above 28 for moderate AD, to discriminate groups. Conclusion: EFPT-BR is a valid test with satisfactory psychometric parameters to discriminate healthy patients with mild AD and moderate AD in performing instrumental tasks. The test provides consistent information to assist in understanding the performance of AD patients in carrying out more autonomous and safe daily life activities
295

Somatiska perspektiv inom balett : en kvalitativ studie om balettlärares användning av somatiska förhållningssätt i undervisning

Hreinsdóttir, Ingunn Elísabet, Dahlrot, Johanna January 2018 (has links)
Ballet and somatic practice are two different fields with separate approaches regarding the body and its movement. Ballet in general is structured by a specific frame emerging from traditions and conventions which have effect on the dancer’s movement patterns and body. On the other hand, a somatic approach initiates movement from within which depends on the individual daily condition. The practitioners are encouraged to work from their own terms, therefore all bodies can be included in somatic practices. The aim of this study was to find out which somatic principles and perspectives ballet teachers use in their ballet teaching and how they relate it to their teaching methods. Our empirical material consist of observations and interviews with three different ballet teachers that took place in Stockholm, which later are processed with content analysis. The content analysis resulted in five main categories. Based on the data collection the result showed that the ballet teachers use somatic approach in their teaching. It also revealed three basic components in their teaching which are: anatomy, the use of language and the use of touch. These three components complement each other and provide the dancer tools to support their dancing as well as becoming more aware of their body’s function. A fundamental element in somatic is the dancer’s negotiation about their bodily needs. Through their choices the dancer can develop a deeper awareness that can maintain a physical balance which leads to a sustainable body.
296

Knowledge management in a global setting : a critique of knowledge transfer and the role of knowledge workers

Konstantinou, Efrosyni January 2008 (has links)
As a form of expert labour and organizational resource, knowledge workers are important in organizational life as producers and consumers of knowledge. The role of knowledge workers and the ways in which they transfer their knowledge become important as they possess the symbolic and analytic skills to undertake work which is contingent upon the application of ambiguous knowledge in uncertain, networked business environments. Yet, in much of the existing literature knowledge workers and knowledge transfer seem to have been partially interpreted and through a perspective maintaining an emphasis on organizational performance. Current understanding of the role of knowledge workers sees knowledge workers as either willing or reluctant to share knowledge, i.e. as either contributing to organizational efficiency or its opposite, while knowledge sharing is unequivocally understood as beneficial for organizational performance. The aim of the study is to produce an interpretation of knowledge transfer and the role of knowledge workers that extends beyond simplified and limited categories. The perspective of the knowledge worker is centrally adopted and, using this approach, the identity of knowledge workers and their interpretation of knowledge sharing are explored. The study focuses on 58 knowledge workers in the subsidiaries of five high-tech multinational companies in Athens, Greece, where complex, ambiguous knowledge work and operational interdependencies are supported by elaborate architectures of Knowledge Management initiatives. The method of data collection is interviews and data have been analysed by using QSR N-VIVO and developing thematic conceptual matrices. The findings suggest that, across organizational contexts, knowledge workers construct and maintain identities of competence and upward mobility and exhibit a combination of behaviour. Here, knowledge is better seen as being traded, rather than shared. Knowledge exchanges are subject to a set of knowledge trading principles which reflect self-interested and instrumental conceptualizations of competence and lead to the discrimination and selection of knowledge categories, uses and groups of colleagues. It is indicated that different conceptualizations of the self and various behaviours co-exist and manifest interchangeably thus both supporting and undermining corporate priorities throughout the course of practice. Knowledge worker self and behaviour play an ambivalent role in relation to corporate priorities disturbing but also harmonizing the organizational context. Monochrome notions of ‘sharing’, or interpretations assuming either the willingness to share knowledge or not reflect only part of who the knowledge worker is and why he/she transfers knowledge.
297

La notion de fonctionnalité en droit canadien : quels fondements pour quels usages?

Jonnaert, Caroline 01 1900 (has links)
Ce mémoire analyse la notion de fonctionnalité. D'origine jurisprudentielle, ce concept tend à maintenir la dichotomie traditionnelle entre le régime des marques de commerce et celui des brevets. À la lecture des jugements rendus en la matière, le maintien d'une telle dichotomie empêcherait notamment de prolonger indûment un monopole échu sous le régime des brevets par l'enregistrement d'une marque de commerce. Cette étude tente de mieux cerner le concept de fonctionnalité et, plus précisément, de justifier son existence. Pour ce faire, une étude approfondie des régimes des marques de commerce et des brevets, nous permet de comprendre que chacun de ces corps de règles répond à une logique différente. Les fonctions des marques de commerce et des brevets sont en effet distinctes et aucun chevauchement ne semble être permis. Cette situation est d'ailleurs propre à ces régimes spécifiques. Un examen de l'étendue de la notion de fonctionnalité nous permet de constater que d'autres droits de propriété intellectuelle peuvent coexister. À titre d'exemple, nous croyons qu'une intersection est possible entre les régimes des dessins industriels et des marques de commerce. À l'issue de ces recherches, nous constatons que la notion de fonctionnalité est un principe jurisprudentiel bien établi en droit canadien visant à empêcher tout renouvellement à perpétuité d'un brevet par le biais du droit des marques de commerce. L'existence de ce principe nous semble être justifiée en matière de marques de commerce et de brevets. Cette conclusion pourrait toutefois différer dans le cadre d'autres droits de propriété intellectuelle, les fonctions de ces autres régimes semblant permettre des chevauchements. / This memory analyzes the notion of functionality. Of case law origin, this concept tends to maintain the traditional dichotomy between trademarks and patents regimes. In light of judgments rendered on that matter, the preservation of such dichotomy would notably prevent from illegally prolonging a monopoly fallen under the regime of patents by the registration of a trademark. This study tries to understand the concept of functionality and, more specifically, to justify its existence. In order to reach this goal, a detailed study of the regimes of trademarks and patents lead us to conclude that each of these bodies of rules answers to a different logic. Indeed, the functions of trademarks and patents are different and no overlapping seems to be allowed. This situation is particular to these two specific regimes. An examination of the area of the notion of functionality leads us to notice that other rights of intellectual property can coexist. For example, we believe that an intersection is possible between the regimes of industrial designs and trademarks. As a conclusion, we notice that the notion of functionality is a well established principle in Canada which tends to prevent any perpetual renewal of a patent under the trademarks regime. We believe that the existence of this concept is justified under trademarks and patents laws. However, this conclusion could differ within the framework of the other intellectual property rights, since these other rights' functions seem to allow an intersection between them.
298

Discovery and Analysis of Aligned Pattern Clusters from Protein Family Sequences

Lee, En-Shiun Annie 28 April 2015 (has links)
Protein sequences are essential for encoding molecular structures and functions. Consequently, biologists invest substantial resources and time discovering functional patterns in proteins. Using high-throughput technologies, biologists are generating an increasing amount of data. Thus, the major challenge in biosequencing today is the ability to conduct data analysis in an effi cient and productive manner. Conserved amino acids in proteins reveal important functional domains within protein families. Conversely, less conserved amino acid variations within these protein sequence patterns reveal areas of evolutionary and functional divergence. Exploring protein families using existing methods such as multiple sequence alignment is computationally expensive, thus pattern search is used. However, at present, combinatorial methods of pattern search generate a large set of solutions, and probabilistic methods require richer representations. They require biological ground truth of the input sequences, such as gene name or taxonomic species, as class labels based on traditional classi fication practice to train a model for predicting unknown sequences. However, these algorithms are inherently biased by mislabelling and may not be able to reveal class characteristics in a detailed and succinct manner. A novel pattern representation called an Aligned Pattern Cluster (AP Cluster) as developed in this dissertation is compact yet rich. It captures conservations and variations of amino acids and covers more sequences with lower entropy and greatly reduces the number of patterns. AP Clusters contain statistically signi cant patterns with variations; their importance has been confi rmed by the following biological evidences: 1) Most of the discovered AP Clusters correspond to binding segments while their aligned columns correspond to binding sites as verifi ed by pFam, PROSITE, and the three-dimensional structure. 2) By compacting strong correlated functional information together, AP Clusters are able to reveal class characteristics for taxonomical classes, gene classes and other functional classes, or incorrect class labelling. 3) Co-occurrence of AP Clusters on the same homologous protein sequences are spatially close in the protein's three-dimensional structure. These results demonstrate the power and usefulness of AP Clusters. They bring in similar statistically signifi cance patterns with variation together and align them to reveal protein regional functionality, class characteristics, binding and interacting sites for the study of protein-protein and protein-drug interactions, for diff erentiation of cancer tumour types, targeted gene therapy as well as for drug target discovery.
299

An Artificial Intelligence-Driven Model-Based Analysis of System Requirements for Exposing Off-Nominal Behaviors

Madala, Kaushik 05 1900 (has links)
With the advent of autonomous systems and deep learning systems, safety pertaining to these systems has become a major concern. The existing failure analysis techniques are not enough to thoroughly analyze the safety in these systems. Moreover, because these systems are created to operate in various conditions, they are susceptible to unknown safety issues. Hence, we need mechanisms which can take into account the complexity of operational design domains, identify safety issues other than failures, and expose unknown safety issues. Moreover, existing safety analysis approaches require a lot of effort and time for analysis and do not consider machine learning (ML) safety. To address these limitations, in this dissertation, we discuss an artificial-intelligence driven model-based methodology that aids in identifying unknown safety issues and analyzing ML safety. Our methodology consists of 4 major tasks: 1) automated model generation, 2) automated analysis of component state transition model specification, 3) undesired states analysis, and 4) causal factor analysis. In our methodology we identify unknown safety issues by finding undesired combinations of components' states and environmental entities' states as well as causes resulting in these undesired combinations. In our methodology, we refer to the behaviors that occur because of undesired combinations as off-nominal behaviors (ONBs). To identify undesired combinations and ONBs that aid in exposing unknown safety issues with less effort and time we proposed various approaches for each of the task and performed corresponding empirical studies. We also discussed machine learning safety analysis from the perspective of machine learning engineers as well as system and software safety engineers. The results of studies conducted as part of our research shows that our proposed methodology helps in identifying unknown safety issues effectively. Our results also show that combinatorial methods are effective in reducing effort and time for analysis of off-nominal behaviors without overlooking any dependencies among components and environmental entities of a system. We also found that safety analysis of machine learning components is different from analysis of conventional software components and detail the aspects we need to consider for ML safety.
300

Analyse du rôle de l’interaction de VirB6 avec VirB10 dans le système de sécrétion de type IV

Mary, Charline 04 1900 (has links)
No description available.

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