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Venösa infarter används för att ge intravenösa läkemedel samt blodprovstagning. De venösa infarter som används inom sjukvården är perifera venkatetrar, midlines, PICC-lines och andra centralvenösa infarter. Midlinekatetern är en perifer infart med längre kateter och längre livslängd än en sedvanlig perifer venkateter, men räknas ej som en centralvenös infart. Indikation för midlines är patienter som är svårstuckna samt har behov av en perifer infart med en livslängd mellan fyra och fjorton dagar.  Syftet med studien var att undersöka patientsäkerheten av midlinekatetrar hos slutenvårdspatienter.  Studiens metod var en litteraturstudie med systematiskt tillvägagångssätt. I resultatet analyserades kvantitativa- och mixed method-artiklar. En induktiv analysmetod användes.  I resultatet framkom det att lokala och systemiska infektioner var relativt låga vid användning av midlinekatetrar. Dock var mekaniska komplikation av högre frekvens hos patienter med midlinekatetrar jämfört med centralvenösa infarter, men lägre än vid användning av perifera venkatetrar. Midlinekatetrar minskar även insättande av centralvenösa infarter vilka har högre risk för svåra komplikationer.  Slutsatsen är att midlinekatetrar, om de används vid rätt indikation, kan minska användning och därmed komplikationer från centralvenösa infarter samt minska lidande hos patienter på grund av upprepade nålstick. Mer svensk forskning behövs då inga svenska artiklar identifierades. Även ett behov av ytterligare forskning med ett patientcentrerat perspektiv fastställdes. / Venous accesses are used to provide intravenous drugs as well as to draw blood samples. The types of venous accesses that are used in hospitals are peripheral venous catheters, midline catheters, PICC-lines and other central venous access devices. A midline catheter is a peripheral access with a longer catheter and longer lifespan than a conventional peripheral venous catheter, but does not count as a central venous access. Indications for midlines are patients with difficult venous accesses and patients with the need of an access with a lifespan between four to 14 days.  The aim of this review was to investigate the patient safety of midline catheters in hospitalised patients.  The method of the study was a review with a systematic approach. Quantitative and mixed method articles were analysed. An inductive analysis method was used.  The results showed that local and systemic infections were relatively low in the use of midline catheters. However, the prevalence of mechanical complications among patients were higher in midline catheters than in central venous devices, but lower than in peripheral venous catheters. Midline catheters can also reduce the use of central venous accesses, which have a higher risk of severe complications.  The conclusion is that midline catheters, if used with the right indication, could decrease the  use and complications from central venous catheters and decrease patient suffering. More Swedish research is needed as no Swedish articles were found. Furthermore a need for additional research with a patient-centered perspective was identified.

Mechanisms for improving the execution efficiency of graph algorithms on Data-Parallel Architectures were proposed and identified. Execution of graph algorithms on GPGPU architectures, the prevalent data-parallel architectures was considered. Irregular and data dependent accesses in graph algorithms were found to cause significant idle cycles in GPGPU cores. A prefetching mechanism that reduced the amount of idle cycles by prefetching a data-dependent access pattern found in graph algorithms was proposed. Storing prefetches in unused spare registers in addition to storing them in the cache was shown to be more effective by the prefetching mechanism. The design of the cache hierarchy for graph algorithms was explored. First, an exclusive cache hierarchy was shown to be beneficial at the cost of increased traffic; a region based exclusive cache hierarchy was shown to be similar in performance to an exclusive cache hierarchy while reducing on-chip traffic. Second, bypassing cache blocks at both the level one and level two caches was shown to be beneficial. Third, the use of fine-grained memory accesses (or cache sub-blocking) was shown to be beneficial. The combination of cache bypassing and fine-grained memory accesses was shown to be more beneficial than applying the two mechanisms individually. Finally, the impact of different implementation strategies on algorithm performance was evaluated for the breadth first search algorithm using different input graphs and heuristics to identify the best performing implementation for a given input graph were also discussed.

Made available in DSpace on 2014-06-11T19:26:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-03-29Bitstream added on 2014-06-13T20:15:26Z : No. of bitstreams: 1 sousa_la_me_botfca.pdf: 322410 bytes, checksum: 0fe9b53ef3e72f89c4e721e86c6496fa (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A espécie Baccharis trimera conhecida como carqueja, está inserida no Bioma pertencente à Mata Atlântica, uma das florestas tropicais com maior diversidade biológica do planeta. Por esse motivo, intervenções científicas que busquem sua preservação e diminuição do extrativismo tornam-se necessárias. Com o intuito de melhorar a qualidade da matéria prima para fitoterápicos, na produção de carqueja sugere-se a adoção de práticas de manejo sustentável e cultivo de plantas selecionadas. A introdução de espécies silvestres no cultivo sistematizado requer estudos fitotécnicos para sondagem do desempenho das mesmas frente a esta condição. Portanto, este trabalho objetivou avaliar a produtividade de três acessos de B. trimera, cultivados sob adubação organo-mineral em casa de vegetação, visto que esta espécie é nativa, de uso medicinal e obtida por extrativismo. Os acessos foram obtidos de plantas procedentes de Botucatu-SP e Campos do Jordão-SP. O experimento foi instalado em esquema fatorial em delineamento de blocos ao acaso (6 tratamentos de adubação x 3 acessos) com 4 repetições. O cultivo foi conduzido em casa de vegetação do Setor de Horticultura do DPV/FCA/UNESP. Os tratamentos constaram de: condição natural do solo (testemunha); adubação orgânica (esterco bovino curtido 30t.ha-1); adubação mineral 1 (NPK-20;80;85kg.ha-1) adubação mineral 2 (NPK-35;120;150kg.ha-1); adubação organo-mineral 1 (esterco bovino curtido 30t.ha-1 + NPK-20;80;85kg.ha-1) e adubação organo-mineral 2 (esterco bovino curtido 30t.ha-1 + NPK-35;120;150kg.ha-1). A adubação foi realizada no transplantio. Após 120 e 240 dias de cultivo, avaliaram-se os seguintes aspectos fitométricos: acúmulo de matéria fresca e seca, largura média das alas caulinares, número de ramificações, altura das plantas... / The Baccharis trimera specie known as carqueja, Atlantic Forest is inserted inside of biom belong, one of the tropical forests of bigger biological diversity of all the planet. For this reason, scientific interventions that search its preservation, they become necessary. With intention to improve the quality of the substance cousin for phytoterapic, in the production of carqueja suggests it adoption of practical of sustainable handling and culture of selecteds plants. The introduction of wild species in the systemize culture requires phytotechnics studies for sounding of the performance of same the front to this condition. Therefore, this work objectified to evaluate the productivity of three accesses of B. trimera, cultivated under fertilization organic-mineral in greenhouse, since this species is native, of use medicinal and gotten by extractivism. The accesses had been gotten of plants originating Botucatu-SP and fields of the Jordão-SP. The experiment was installed in factorial project in delineation of randomized blocks (the 6 treatments of fertilization x 3 accesses) and 4 repetitions. The culture was lead in greenhouse of the Horticulture Sector of the DPV/FCA/UNESP. The treatments had consisted of: natural condition of the ground (witness); organic fertilization (30t.ha-1 farm yard manure); mineral fertilization 1 (NPK-20;80;85kg.ha-1) mineral fertilization 2 (NPK-35;120;150kg. ha-1); fertilization organic-mineral 1 (30t.ha-1 farm yard manure + NPK-20;80;85 kg.ha-1) and fertilization organic-mineral 2 (60t.ha-1 farm yard manure + NPK-35;120;150kg.ha-1). The fertilization was carried through in the plantation. After 120 and 240 days of culture, the phytometrics aspects of the aerial part had been evaluated: cool substance and dries, average width of the sections stems, number of ramifications, height of the plants and texts of nitrogen (N), phosphorus (P) and potassium (K)...(Complete abstract click electronic access below)

Made available in DSpace on 2015-03-26T13:40:06Z (GMT). No. of bitstreams: 1 texto completo.pdf: 306256 bytes, checksum: 5e206a1bfc74dd2b223fdef1b7789111 (MD5) Previous issue date: 2007-03-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The genetic variability of nine accesses of tomato (Lycopersicon esculentum Mill.) of indeterminate type, of the Vegetable Germplasm Bank of the Viçosa Federal University was evaluated for photosynthetic capacity (A), dry matter, partitioning dry matter and yield, having been used as standard of the cultivating tomato the Santa Clara cultivar. The experiment was lead in protecting environment and favorable conditions of the irrigation, nutrition and temperature requirements, in randomized complete block design, with 10 treatments and 5 repetitions. It was measured photosynthesis with analyzer of gas for infra-red ray, LI-6400, between 51 and 56 days before of the transplanting (DBT). To the 83 DAT and in the end of the productive cycle (EPC), IAF was determined. In EPC the dry mass of the fruits, leaves, roots and shoots was gotten for drying in dryer equipment to 75ºC until constant weight. The partitioning index of leaves, shoot, root and fruit had been calculated that the reason between dry matter of each part and the dry matter total and expresses in relative values. The data had been submitted analyze of variance (F; p<0,01), test of Tukey (p<0,05) and Pearson correlation (r) using statistical software SAEG 9. The results had shown to genetics significant variability (test F, p<0,01) for all the evaluated characteristics. Was determined too, that not exist correlation between A, dry matter total and yield, but IAF correlated negatively with A. The assimilate partitioning to vegetative part competes strong with the one of the fruits. This showed that are possible to have productive plants with small IAF to the ones of the current tomato cultivate, if to combine high A and harvest index, being allowed to visualize one another ideotype of plants that demand little resources for similar unit of plant with current productivity cultivar. Promising accesses for favorable characteristics of the evaluated had been identified. / Foi avaliada a variabilidade genética de nove acessos de tomateiro de tipo indeterminado do Banco de Germoplasma de Hortaliças da Universidade Federal de Viçosa, com base na capacidade fotossintética (A), matéria seca total, partição de fotoassimilados e produção. Tendo sido utilizado como padrão de referencia o cultivar Santa Clara. O experimento foi conduzido em ambiente protegido e condições favoráveis de irrigação, nutrição e temperatura, em delineamento de blocos completos casualizados, com 10 tratamentos e 5 repetições. Mediu-se a fotossíntese, com analisador de gás por infravermelho LI-6400, entre 51 e 56 dias após do transplante (DAT). Aos 83 DAT e no final do ciclo produtivo foi determinado IAF. No final do ciclo produtivo foi obtida a massa seca dos frutos, folhas, caule e raiz por secagem em estufa a 75 ºC até peso constante. Os índices de partição de assimilados às folhas, caule, raiz e fruto foram calculados com base na fração da massa total seca e expressos em valores relativos. Os dados foram submetidos a analise de variância (F; p<0,01), teste de Tukey (p<0,05) e correlação de Pearson (r), utilizando o programa estatístico SAEG 9. Os resultados mostraram significativa variabilidade genética para todas as características avaliadas (Teste F; p< 0,01). Entre os acessos estudados não houve correlação alguma entre A, matéria seca total e produção. A correlacionou negativamente com IAF. Matéria seca e partição de assimilados não tiveram associação alguma. A partição de fotoassilados à parte vegetativa, compete fortemente com a dos frutos. Este conjunto de relações mostra que é possível ter plantas produtivas com menores IAF aos das atuais cultivares, se combinar, elevadas A e índices de partição aos frutos, permitindo visualizar um outro ideotipo de plantas que demandam menos recursos por unidade de planta com produtividade similares às atuais cultivares. Foram identificados acessos promissores para combinações favoráveis das características avaliadas.

In content-based image retrieval (CBIR) systems, there are two general types of search: target search and category search. Unlike queries in traditional database systems, users in most cases cannot specify an ideal query to retrieve the desired results for either target search or category search in multimedia database systems, and have to rely on iterative feedback to refine their query. Efficient evaluation of such iterative queries can be a challenge, especially when the multimedia database contains a large number of entries, and the search needs many iterations, and when the underlying distance measure is computationally expensive. The overall processing costs, including CPU and disk I/O, are further emphasized if there are numerous concurrent accesses. To address these limitations involved in relevance feedback processing, we propose a generic framework, including a query model, index structures, and query optimization techniques. Specifically, this thesis has five main contributions as follows. The first contribution is an efficient target search technique. We propose four target search methods: naive random scan (NRS), local neighboring movement (LNM), neighboring divide-and-conquer (NDC), and global divide-and-conquer (GDC) methods. All these methods are built around a common strategy: they do not retrieve checked images (i.e., shrink the search space). Furthermore, NDC and GDC exploit Voronoi diagrams to aggressively prune the search space and move towards target images. We theoretically and experimentally prove that the convergence speeds of GDC and NDC are much faster than those of NRS and recent methods. The second contribution is a method to reduce the number of expensive distance computation when answering k-NN queries with non-metric distance measures. We propose an efficient distance mapping function that transfers non-metric measures into metric, and still preserves the original distance orderings. Then existing metric index structures (e.g., M-tree) can be used to reduce the computational cost by exploiting the triangular inequality property. The third contribution is an incremental query processing technique for Support Vector Machines (SVMs). SVMs have been widely used in multimedia retrieval to learn a concept in order to find the best matches. SVMs, however, suffer from the scalability problem associated with larger database sizes. To address this limitation, we propose an efficient query evaluation technique by employing incremental update. The proposed technique also takes advantage of a tuned index structure to efficiently prune irrelevant data. As a result, only a small portion of the data set needs to be accessed for query processing. This index structure also provides an inexpensive means to process the set of candidates to evaluate the final query result. This technique can work with different kernel functions and kernel parameters. The fourth contribution is a method to avoid local optimum traps. Existing CBIR systems, designed around query refinement based on relevance feedback, suffer from local optimum traps that may severely impair the overall retrieval performance. We therefore propose a simulated annealing-based approach to address this important issue. When a stuck-at-a-local-optimum occurs, we employ a neighborhood search technique (i.e., simulated annealing) to continue the search for additional matching images, thus escaping from the local optimum. We also propose an index structure to speed up such neighborhood search. Finally, the fifth contribution is a generic framework to support concurrent accesses. We develop new storage and query processing techniques to exploit sequential access and leverage inter-query concurrency to share computation. Our experimental results, based on the Corel dataset, indicate that the proposed optimization can significantly reduce average response time while achieving better precision and recall, and is scalable to support a large user community. This latter performance characteristic is largely neglected in existing systems making them less suitable for large-scale deployment. With the growing interest in Internet-scale image search applications, our framework offers an effective solution to the scalability problem.

Orientador: Luis Vítor Silva do Sacramento / Banca: Dirceu Maximino Fernandes / Banca: José Roberto Pinto de Souza / Resumo: A espécie Baccharis trimera conhecida como carqueja, está inserida no Bioma pertencente à Mata Atlântica, uma das florestas tropicais com maior diversidade biológica do planeta. Por esse motivo, intervenções científicas que busquem sua preservação e diminuição do extrativismo tornam-se necessárias. Com o intuito de melhorar a qualidade da matéria prima para fitoterápicos, na produção de carqueja sugere-se a adoção de práticas de manejo sustentável e cultivo de plantas selecionadas. A introdução de espécies silvestres no cultivo sistematizado requer estudos fitotécnicos para sondagem do desempenho das mesmas frente a esta condição. Portanto, este trabalho objetivou avaliar a produtividade de três acessos de B. trimera, cultivados sob adubação organo-mineral em casa de vegetação, visto que esta espécie é nativa, de uso medicinal e obtida por extrativismo. Os acessos foram obtidos de plantas procedentes de Botucatu-SP e Campos do Jordão-SP. O experimento foi instalado em esquema fatorial em delineamento de blocos ao acaso (6 tratamentos de adubação x 3 acessos) com 4 repetições. O cultivo foi conduzido em casa de vegetação do Setor de Horticultura do DPV/FCA/UNESP. Os tratamentos constaram de: condição natural do solo (testemunha); adubação orgânica (esterco bovino curtido 30t.ha-1); adubação mineral 1 (NPK-20;80;85kg.ha-1) adubação mineral 2 (NPK-35;120;150kg.ha-1); adubação organo-mineral 1 (esterco bovino curtido 30t.ha-1 + NPK-20;80;85kg.ha-1) e adubação organo-mineral 2 (esterco bovino curtido 30t.ha-1 + NPK-35;120;150kg.ha-1). A adubação foi realizada no transplantio. Após 120 e 240 dias de cultivo, avaliaram-se os seguintes aspectos fitométricos: acúmulo de matéria fresca e seca, largura média das alas caulinares, número de ramificações, altura das plantas ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Baccharis trimera specie known as carqueja, Atlantic Forest is inserted inside of biom belong, one of the tropical forests of bigger biological diversity of all the planet. For this reason, scientific interventions that search its preservation, they become necessary. With intention to improve the quality of the substance cousin for phytoterapic, in the production of carqueja suggests it adoption of practical of sustainable handling and culture of selecteds plants. The introduction of wild species in the systemize culture requires phytotechnics studies for sounding of the performance of same the front to this condition. Therefore, this work objectified to evaluate the productivity of three accesses of B. trimera, cultivated under fertilization organic-mineral in greenhouse, since this species is native, of use medicinal and gotten by extractivism. The accesses had been gotten of plants originating Botucatu-SP and fields of the Jordão-SP. The experiment was installed in factorial project in delineation of randomized blocks (the 6 treatments of fertilization x 3 accesses) and 4 repetitions. The culture was lead in greenhouse of the Horticulture Sector of the DPV/FCA/UNESP. The treatments had consisted of: natural condition of the ground (witness); organic fertilization (30t.ha-1 farm yard manure); mineral fertilization 1 (NPK-20;80;85kg.ha-1) mineral fertilization 2 (NPK-35;120;150kg. ha-1); fertilization organic-mineral 1 (30t.ha-1 farm yard manure + NPK-20;80;85 kg.ha-1) and fertilization organic-mineral 2 (60t.ha-1 farm yard manure + NPK-35;120;150kg.ha-1). The fertilization was carried through in the plantation. After 120 and 240 days of culture, the phytometrics aspects of the aerial part had been evaluated: cool substance and dries, average width of the sections stems, number of ramifications, height of the plants and texts of nitrogen (N), phosphorus (P) and potassium (K)...(Complete abstract click electronic access below) / Mestre

El presente trabajo de investigación tiene como objetivo mejorar el proceso de Monitoreo de Accesos y Comportamiento de Usuarios en Entorno Cloud de la gerencia de Seguridad Tecnológica, este proceso es uno de los principales controles en el programa de seguridad de la información y ciberseguridad de Mibanco por contribuir en la detección oportuna de eventos de seguridad, evitar incidentes que pudieran afectar a la organización y por el cumplimiento de estándares de seguridad que debe cumplir toda entidad financiera. El trabajo de investigación se desarrolló en seis capítulos donde en primer lugar, se detalla el Marco Teórico utilizado; luego en el capítulo de Desarrollo de Proyecto, se realiza el análisis de la arquitectura empresarial y la identificación de los problemas objetivos que se deben trabajar para la mejora del proceso. Asimismo, en los demás capítulos se desarrolló la arquitectura de software de solución y la gestión del proyecto. / The objective of this research work is to improve the process of Monitoring Accesses and User Behavior in the Cloud Environment of the Technological Security management, this process is one of the main controls in the information security and cybersecurity program of Mibanco by contribute to the timely detection of security events, avoid incidents that could affect the organization and for the fulfillment of security standards that every financial entity must comply with. The research work was developed in six chapters where, first, the Theoretical Framework used is detailed; Then, in the Project Development chapter, the analysis of the business architecture and the identification of the objective problems that must be worked on to improve the process is carried out. Likewise, in the other chapters the solution software architecture and project management were developed. / Tesis

La caractérisation des composants hyperfréquences après leur fabrication, est généralement réalisée par la mesure de paramètres S à l’aide d’un analyseur vectoriel de réseau (VNA). La précision de mesure dépend étroitement de la qualité du calibrage de l’analyseur vectoriel, qui permet de corriger les erreurs inhérentes au système de mesure. Des composants particuliers, dits étalons ou standards, dont les paramètres sont complètement ou partiellement connus, sont mesurés lors de la procédure de calibrage afin de déterminer les erreurs systématiques du système. La réalisation d’un circulateur coplanaire (les trois ports sont à 120 degrés les uns des autres) travaillant autour de 40 GHz est l’un des axes de recherche du laboratoire depuis plusieurs années et la caractérisation des prototypes a toujours été un souci important. Le calibrage est réalisé avec un kit commercial, avec les pointes positionnées en face à face. La mesure des dispositifs CPW à accès orthogonaux ou obliques après un calibrage avec un ensemble de standards conventionnels (droits) peut engendrer des erreurs supplémentaires. L’objectif de notre travail est donc de concevoir un ensemble de standards à accès inclinés à 120 degrés permettant de calibrer l’analyseur vectoriel « 2-ports » en positionnant directement les pointes à 120 degrés. La méthode de calibrage TRL (THRU – REFLECT - LINE) a été choisie. Le travail à accomplir se résume comme suit : - faire une étude de simulation du nouveau kit de calibrage à concevoir ; - mettre en évidence l’effet des accès coudés sur les lignes de transmission des standards ; - proposer une méthode de calcul qui tient compte de ces effets lors de la procédure de calibrage ; - mesurer quelques échantillons réalisés afin de vérifier la validité de la procédure de calibrage proposée. Les résultats obtenus au cours de ce travail ont pu être validés expérimentalement et offrent de nouvelles perspectives pour la mesure des composants planaires à accès non conventionnels / Microwave components characterization after the fabrication steps is usually performed by measuring S parameters using a Vector Network Analyzer (VNA). The measurement accuracy is highly dependent on the quality of the VNA calibration, which corrects the inherent errors in the measurement system. Specific components, called standards and whose parameters are completely or partially known, are measured during the calibration procedure to determine systematic errors of the system. Fabricating a coplanar circulator (the three ports are at 120 degrees position) functioning around 40 GHz is one of the laboratory’s research areas for several years and characterization of prototypes has always been a major concern. Usually, the calibration is made with a commercial kit ; probes are in face-to-face position. Measurements of CPW devices with orthogonal or bended accesses (120 degrees in our case) after VNA calibration with conventional (straight) set of standards may generate additional errors. The aim of our work is to design a set of standards with 120_ bended accesses allowing the calibration of the “2-ports” network analyzer. Therefore, probes are directly set at 120_ position. TRL (THRU - REFLECT -LINE) calibration procedure is chosen for the standards design. The work to be done is as follows : - to make a simulation study of the new calibration kit to design ; - to determine the bended accesses effects on the standards transmission lines ; - to propose a calculation method that takes account of these effects during the calibration procedure ; - to measure some fabricated samples to verify the validity of the proposed calibration procedure. The results of this research work have been experimentally validated and offer new perspectives for measuring planar components with unconventional accesses

Une des étapes les plus cruciales dans le processus d’analyse des performances d’une application est la détection des goulets d’étranglement. Un goulet étant tout évènement qui contribue à l’allongement temps d’exécution, la détection de ses causes est importante pour les développeurs d’applications afin de comprendre les défauts de conception et de génération de code. Cependant, la détection de goulets devient un art difficile. Dans le passé, des techniques qui reposaient sur le comptage du nombre d’évènements, arrivaient facilement à trouver les goulets. Maintenant, la complexité accrue des micro-architectures modernes et l’introduction de plusieurs niveaux de parallélisme ont rendu ces techniques beaucoup moins efficaces. Par conséquent, il y a un réel besoin de réflexion sur de nouvelles approches.Notre travail porte sur le développement d’outils d’évaluation de performance des boucles de calculs issues d’applications scientifiques. Nous travaillons sur Decan, un outil d’analyse de performance qui présente une approche intéressante et prometteuse appelée l’Analyse Décrémentale. Decan repose sur l’idée d’effectuer des changements contrôlés sur les boucles du programme et de comparer la version obtenue (appelée variante) avec la version originale, permettant ainsi de détecter la présence ou pas de goulets d’étranglement.Tout d’abord, nous avons enrichi Decan avec de nouvelles variantes, que nous avons conçues, testées et validées. Ces variantes sont, par la suite, intégrées dans une analyse de performance poussée appelée l’Analyse Différentielle. Nous avons intégré l’outil et l’analyse dans une méthodologie d’analyse de performance plus globale appelée Pamda.Nous décrirons aussi les différents apports à l’outil Decan. Sont particulièrement détaillées les techniques de préservation des structures de contrôle du programme,ainsi que l’ajout du support pour les programmes parallèles.Finalement, nous effectuons une étude statistique qui permet de vérifier la possibilité d’utiliser des compteurs d’évènements, autres que le temps d’exécution, comme métriques de comparaison entre les variantes Decan / A crucial step in the process of application performance analysis is the accurate detection of program bottlenecks. A bottleneck is any event which contributes to extend the execution time. Determining their cause is important for application developpers as it enable them to detect code design and generation flaws.Bottleneck detection is becoming a difficult art. Techniques such as event counts,which succeeded to find bottlenecks easily in the past, became less efficient because of the increasing complexity of modern micro-processors, and because of the introduction of parallelism at several levels. Consequently, a real need for new analysis approaches is present in order to face these challenges.Our work focuses on performance analysis and bottleneck detection of computeintensive loops in scientific applications. We work on Decan, a performance analysis and bottleneck detection tool, which offers an interesting and promising approach called Decremental Analysis. The tool, which operates at binary level, is based on the idea of performing controlled modifications on the instructions of a loop, and comparing the new version (called variant) to the original one. The goal is to assess the cost of specific events, and thus the existence or not of bottlenecks.Our first contribution, consists of extending Decan with new variants that we designed, tested and validated. Based on these variants, we developed analysis methods which we used to characterize hot loops and find their bottlenecks. Welater, integrated the tool into a performance analysis methodology (Pamda) which coordinates several analysis tools in order to achieve a more efficient application performance analysis.Second, we introduce several improvements on the Decan tool. Techniquesdeveloped to preserve the control flow of the modified programs, allowed to use thetool on real applications instead of extracted kernels. Support for parallel programs(thread and process based) was also added. Finally, our tool primarily relying on execution time as the main concern for its analysis process, we study the opportunity of also using other hardware generated events, through a study of their stability, precision and overhead