Dissertations / Theses on the topic 'Science – atlases'
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Ekström, Ola, and Jonas Olsfelt. "Self-organizing maps : en atlas över informationsrymden." Thesis, Högskolan i Borås, Institutionen Biblioteks- och informationsvetenskap / Bibliotekshögskolan, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-16791.
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The purpose of this thesis is to examine how semantic relations in a document collection can be visualized with a Kohonen self-organizing map. It can be seen as a map of the information space which can be used to support information retrieval. The study makes a comparison of the possible differences between a map that is based on morphologically unprocessed text and a map where the text has been lemmatized. The text that is being processed is the definitions of all the existing instances in WordNet of a random selection of indexing terms from the Times-collection. The purpose is to see if morphological processing somehow can show different semantic connections between term instances based on their definitions. Eventually some different cartographic and display methods are compared to examine their strengths and weaknesses when used as possible applications of information visualization. The results show only marginal advantage of visualization based on lemmatized text. The lemmatization brings together new instances of words but the semantic relations are far from unambiguous. The conclusion drawn from this study is that the authors didn't find any single visualization method that can show all aspects in a map. Different combinations of three and two dimensional methods might be required to get a better picture of an information space.Uppsatsnivå: D
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Thomas, Joel. "COMPARATIVE ANALYSIS OF WIND ATLASES: WIND RESOURCE ASSESSMENT OF FORESTED SITES FOR WIND POWER DEVELOPMENT." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-448544.
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Wind atlases are interactive databases used extensively for preliminary wind resource assessment aimed at optimal wind power development. The selection and processing of wind atlas data are important and will determine the quality of the subsequent WRA (Wind Resource Assessment) phases. This study aims to compare, process, and interpret different wind atlases in determining effective wind resource analysis for 14 different sites in Sweden. The wind atlas data is accessed, parsed, and compared using multiple methodologies to ensure a fair comparison. Several variables like wind speed, wind direction, temperature, production values, etc. are analysed and compared amongst the wind atlas data. The corrected versions of the data are drawn out to conclude and determine how well those databases represent the realistic conditions in a forested site. The data is also compared and validated with measurement data. The results indicate several layers of insights into the wind resource regime. The preliminary results from 14 sites show that New European Wind Atlas (NEWA) and Global Wind Atlas (GWA) agreed sufficiently on the subject of the wind conditions for most of the sites. Methodologies like downscaling and long-term correction introduced to the wind atlas data provided more insights and proved that the database could expand and include more complex wind conditions in the coming years. Furthermore, the comparison and analysis of wind atlas data along with measurement data revealed that NEWA aligned the most to the actual wind conditions for a site. Several uncertainties are considered but more validation and thorough insights in the future could determine and give more affirmations to the idea put forward. Further studies could be conducted along with the inclusion of additional layers, variables, and databases to the wind atlases.
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Hagemann, Kilian. "Mesoscale wind atlas of South Africa." Doctoral thesis, University of Cape Town, 2008. http://hdl.handle.net/11427/5287.
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This thesis explores the utility of the MM5 regional climate model iii product big a detailed wind climatology for South Africa in the context of wind power applications. Given the background of limited available computational resources a sophisticated temporal subsetting algorithm is developed and applied. The goal here is to allow a high resolution 18 by 18km simulation to be carried out over only 365 days of historical records (20 March 1996 until 19 March 1997), yet ensure that it is possible to construct a reasonably accurate climatology from such a short time period because it represents the most typical year available. Throughout the research the modelâs sensitivity towards different boundary layer and cwnulus parametrisations as well as observational and grid nudging is investigated in depth. New error metrics are specifically designed and applied based on 17 reliable lOni weather stations around the country with the specific purpose of evaluating model skill with respect to the wind patterns that are important for wind turbines. An optimal model configuration is established by using the Pleim Xiu land surface scheme coupled with the Atmospheric Convective Model for the planetary boundary layer, in addition to the Kain Fiitsch II cumulus parametrisation and observational wind nudging. The model is then integrated at 18km for the entire country and the results validated in detail. It is found that average wind speeds are within 0.2 + 0.7ms (68% confidence interval) and that the daily cycle, which constitutes the largest part of the observed variance, is predicted to within 18% + 20% of amplitude and lii of timing at coastal sites.
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Hossler, Fred E. "Ultrastructure Atlas of Human Tissues." Digital Commons @ East Tennessee State University, 2014. http://amzn.com/1118284534.
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Presents a variety of scanning and transmission electron microscope images of the major systems of the human body. This book looks at the structure and function of tissues at the subcellular and molecular level, an important perspective in understanding and combating diseases.https://dc.etsu.edu/etsu_books/1047/thumbnail.jpg
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Dyrebrant, Tobias. "Utveckling av användargränssnittet för Atlas Copcos portal för samarbete med underleverantörer (SCP)." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-51592.
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Vid skapandet av ett användargränssnitt bör en utvecklare utgå från en rad designprinciper. Detta möjliggör ett effektivt användarflöde, där användaren navigerar genom systemet utan svårigheter. Därigenom kan användaren till fullo absorbera informationen som systemet erbjuder. Designprinciperna ligger till grund för det praktiska arbetet som utfördes för denna rapport. Syftet var att utveckla en webbportal som användes av ett företag för samarbete med dess underleverantörer. Genom att utgå från principerna, samt intervjuer med användarna, skulle förbättringar göras på det nuvarande systemet. Detta skulle resultera i en bättre användarupplevelse och en optimal effektivitet för systemet. Det praktiska arbetet delades upp i två steg. Det första steget innefattade konkreta ändringar på det nuvarande systemet, där mindre justeringar introducerades som enkelt kunde implementeras på den nuvarande webbportalen. Det andra steget handlade om en analys av marknadens främsta designlösningar, vilket skulle visa på existerande smarta och trendanpassade lösningar som kunde användas vid förbättring av systemet. Dessa steg utgjorde processen för det förbättringsarbete som skulle utföras på webbportalen. Resultatet blev ett användargränssnitt som tillfredsställer majoriteten av användare. Genom de objektiva designprinciperna skapades ett användarvänligt system med ett effektivt användarflöde.When creating a user interface, a developer should base their work on a number of design principles. This enables an effective user flow, where the user navigates through the system without difficulties. Thereby the user can absorb the information that the system provides to the fullest. These design principles form the basis of the practical work that was carried out for this report. The purpose was to develop a web portal, which was used by a company for collaboration with its suppliers. By basing the development on the principles, as well as interviews with the users, improvements were to be made on the current system. This should result in a better user experience and an optimal efficiency of the system. The practical work was divided into two stages. The first stage involved concrete changes on the current system, where smaller adjustments were introduced that could easily be implemented on the current web portal. The second stage was about an analysis of the market's leading design solutions, which should show existing smart and up-to-date solutions that could be used to improve the system. These steps constituted the process of improvement work that was to be carried out on the web portal. The result was a user interface that satisfies the majority of users. Through the objective design principles a user friendly system with an efficient user flow was created.
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Parker, Vincent. "Statistical analysis of bird atlas data from Swaziland." Master's thesis, University of Cape Town, 1995. http://hdl.handle.net/11427/20195.
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The question of what determines the observed geographical distributions of animal species is one of great interest to natural scientists. In general terms, these distributions are known to be related to a number of environmental factors, but the nature of the relationships and the relative importance of the different factors remain poorly understood. This investigation sets out to obtain more insight into these questions by using statistical methods to explore the relationships between the observed geographical distributions of bird species in Swaziland and a number of environmental variables. In 1985 I set out to compile a bird atlas of Swaziland. Data were accumulated between 1985 and 1991 and the bird atlas submitted to a publisher in May 1993. The text of the bird atlas is included here as Appendix 2 because it provides the essential background to this dissertation. The introductory section of the atlas includes a description of the data gathering process. The analysis included in the bird atlas was aimed at a popular readership and was not intended to form part of an academic dissertation Chapter 1 describes the use of logistic regression to investigate the relationships between the bird distribution patterns and a set of environmental variables and to predict the distributions. Chapter 2 describes the results of applying the methods described in Chapter 1 for all of the bird species for which data were available. Because this paper was aimed at a different readership, some repetition of material contained in Chapter 1 was unavoidable. In Chapter 3, biplot techniques were used to obtain a graphical representation of the bird atlas data.
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Arbisser, Amelia M. "Multi-atlas segmentation in head and neck CT scans." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76905.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 45-46).
We investigate automating the task of segmenting structures in head and neck CT scans, to minimize time spent on manual contouring of structures of interest. We focus on the brainstem and left and right parotids. To generate contours for an unlabeled image, we employ an atlas of labeled training images. We register each of these images to the unlabeled target image, transform their structures, and then use a weighted voting method for label fusion. Our registration method starts with multi-resolution translational alignment, then applies a relatively higher resolution affine alignment. We then employ a diffeomorphic demons registration to deform each atlas to the space of the target image. Our weighted voting method considers one structure at a time to determine for each voxel whether or not it belongs to the structure. The weight for a voxel's vote from each atlas depends on the intensity difference of the target and the transformed gray scale atlas image at that voxel, in addition to the distance of that voxel from the boundary of the structure. We evaluate the method on a dataset of sixteen labeled images, generating automatic segmentations for each using the other fifteen images as the atlas. We evaluated the weighted voting method and a majority voting method by comparing the resulting segmentations to the manual segmentations using a volume overlap metric and the distances between contours. Both methods produce accurate segmentations, our method producing contours with boundaries usually only a few millimeters away from the manual contour. This could save physicians considerable time, because they only have to make small modifications to the outline instead of contouring the entire structure.
by Amelia M. Arbisser.
M.Eng.
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Custo, Anna. "Purely optical tomography : atlas-based reconstruction of brain activation." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44446.
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Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 151-161).
Diffuse Optical Tomography (DOT) is a relatively new method used to image blood volume and oxygen saturation in vivo. Because of its relatively poor spatial resolution (typically no better than 1-2 cm), DOT is increasingly combined with other imaging techniques, such as MRI, fMRI and CT, which provide high-resolution structural information to guide the characterization of the unique physiological information offered by DOT. This work aims at improving DOT by offering new strategies for a more accurate, efficient, and faster image processor. Specifically, after investigating the influence of Cerebral Spinal Fluid (CSF) properties on the optical measurements, we propose using a realistic segmented head model that includes a novel CSF segmentation approach for a more accurate solution of the DOT forward problem. Moreover, we outline the benefits and applicability of a Diffusion Approximation-based faster forward model solver. We also describe a new registration algorithm based on superficial landmarks which is an essential tool for the purely optical tomographic image process proposed here. A purely optical tomography of the brain during neural activity will greatly enhance DOT applicability and provide many advantages, in the sense that DOT low cost, portability and non-invasiveness would be fully exploited without the compromises due to the MRI role in the DOT forward image process. We achieve a purely optical tomography by using a generalized head model (or atlas) in place of the subject specific anatomical MRI. We validate the proposed imaging protocol by comparing measurements derived from the DOT forward problem solution obtained using the subject specific anatomical model versus these acquired using the atlas registered to the subject, using a database of 31 healthy human. subjects, and focusing on a set of 12 functional regions of interest.
(cont.) We conclude our study presenting data obtained from 3 experimental subjects having undergone median nerve stimuli. We apply our purely optical tomography protocol to the 3 subjects and analyze the observations derived from both the DOT forward and inverse solutions. The experimental results demonstrate that it is possible to guide the DOT forward problem with a general anatomical model in place of the subject's specific head geometry to localize the macro anatomical structures of neural activity.
by Anna Custo.
Sc.D.
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Bosse, Michael Carsten. "ATLAS: a framework for large scale automated mapping and localization." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/30088.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (p. 203-207).
This thesis describes a scalable robotic navigation system that builds a map of the robot's environment on the fly. This problem is also known as Simultaneous Localization and Mapping (SLAM). The SLAM problem has as inputs the control of the robot's motion and sensor measurements to features in the environment. The desired output is the path traversed by the robot (localization) and a representation of the sensed environment (mapping). The principal contribution of this thesis is the introduction of a framework, termed Atlas, that alleviates the computational restrictions of previous approaches to SLAM when mapping extended environments. The Atlas framework partitions the SLAM problem into a graph of submaps, each with its own coordinate system. Furthermore, the framework facilitates the modularity of sensors, map representations, and local navigation algorithms by encapsulating the implementation specific algorithms into an abstracted module. The challenge of loop closing is handled with a module that matches submaps and a verification procedure that trades latency in loop closing with a lower chance of incorrect loop detections inherent with symmetric environments. The framework is demonstrated with several datasets that map large indoor and urban outdoor environments using a variety of sensors: a laser scanner, sonar rangers, and omni-directional video.
by Michael Carsten Bosse.
Ph.D.
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Liang, Tong. "Atlas-based Segmentation of Temporal Bone Anatomy." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1491835850819812.
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Sloper, John Erik. "Error management in ATLAS TDAQ : an intelligent systems approach." Thesis, University of Warwick, 2010. http://wrap.warwick.ac.uk/34613/.
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This thesis is concerned with the use of intelligent system techniques (IST) within a large distributed software system, specifically the ATLAS TDAQ system which has been developed and is currently in use at the European Laboratory for Particle Physics(CERN). The overall aim is to investigate and evaluate a range of ITS techniques in order to improve the error management system (EMS) currently used within the TDAQ system via error detection and classification. The thesis work will provide a reference for future research and development of such methods in the TDAQ system. The thesis begins by describing the TDAQ system and the existing EMS, with a focus on the underlying expert system approach, in order to identify areas where improvements can be made using IST techniques. It then discusses measures of evaluating error detection and classification techniques and the factors specific to the TDAQ system. Error conditions are then simulated in a controlled manner using an experimental setup and datasets were gathered from two different sources. Analysis and processing of the datasets using statistical and ITS techniques shows that clusters exists in the data corresponding to the different simulated errors. Different ITS techniques are applied to the gathered datasets in order to realise an error detection model. These techniques include Artificial Neural Networks (ANNs), Support Vector Machines (SVMs) and Cartesian Genetic Programming (CGP) and a comparison of the respective advantages and disadvantages is made. The principle conclusions from this work are that IST can be successfully used to detect errors in the ATLAS TDAQ system and thus can provide a tool to improve the overall error management system. It is of particular importance that the IST can be used without having a detailed knowledge of the system, as the ATLAS TDAQ is too complex for a single person to have complete understanding of. The results of this research will benefit researchers developing and evaluating IST techniques in similar large scale distributed systems.
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Missenard, Yves. "Le relief des Atlas Marocains : contribution des processus asthénosphériques et du raccourcissement crustal, aspects chronologiques." Phd thesis, Université de Cergy Pontoise, 2006. http://tel.archives-ouvertes.fr/tel-00125775.
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L'objectif de cette thèse est l'étude des mouvements verticaux et la caractérisation des processus à l'origine de ces mouvements au sein d'une chaîne de montagnes intracontinentale. Les mécanismes contrôlant l'évolution de la topographie sont nombreux et encore mal connus. La chaîne du Haut Atlas marocain est située à plus de 600 km de la limite de plaque Afrique-Europe et supporte pourtant le deuxième sommet d'Afrique (Jbel Toubkal, 4165 m). L'absence de racine crustale développée sous la chaîne, conséquence d'un taux de raccourcissement assez faible (~20 km), implique donc l'existence d'un autre processus permettant de maintenir une telle topographie. La réalisation de profils géophysiques nous permet de montrer qu'un amincissement lithosphérique provoque un soulèvement d'environ 1000 m dans l'Anti-Atlas, le Haut Atlas Central, et le Moyen Atlas. Certains bassins d'avant-pays sont aussi affectés, comme les bassins du Souss, de Ouarzazate ou de Missour. La zone amincie est une bande d'orientation Nord-Est / Sud-Ouest recoupant les principaux domaines structuraux marocains et probablement lalimite de plaque Afrique-Europe.
Le raccourcissement crustal est le deuxième mécanisme à l'origine du relief de cette chaîne. Une analyse structurale sur la base des données de terrain dans le Haut Atlas de Marrakech nous a permis de montrer l'existence d'une stratigraphie mécanique contrastée. Plusieurs niveaux de décollements potentiels y sont identifiés en particulier dans le Viséen, le Cambrien, le Trias et le Sénonien. L'héritage complexe de cette région, située à la limite entre les rifts Triasico-Liasiques Atlantique et Téthysien, contrôle leur activation sur les bordures de la chaîne. Celle-ci entraîne la formation de structures variées : zones triangulaires, plis secondaires (« rabbit ears »), imbrications. Un groupe basal rigide est distingué. Il inclut le Précambrien, et localement le Paléozoique et le Trias. Une coupe complète de la
chaîne est présentée.
La chronologie de la déformation et l'âge de l'amincissement de la lithosphère sous la chaîne sont finalement discutés. Une analyse détaillée de la géologie de l'avant-pays sud du Haut Atlas de Marrakech est combinée aux résultats obtenus par comptage de traces de fissions pour proposer un scénario d'évolution. Une première phase de raccourcissement est identifiée à l'Eocène Supérieur – Oligocène. Au Miocène Inférieur – Moyen, la lithosphère est amincie et une phase de dénudation affecte l'ensemble de la chaîne et son avant-pays. Enfin, une dernière phase de raccourcissement a lieu au Plio-Quaternaire.
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Damet, Jerome. "Physics and Detector Simulation Studies of B-Meson Decays in ATLAS." Doctoral thesis, Uppsala University, Department of Nuclear and Particle Physics, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1284.
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Zhang, Jia Ph D. Massachusetts Institute of Technology. "The constant atlas : mapping public data for individuals and their cities." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/119075.
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Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 131-136).
Over the past ten years the ability of institutions and businesses to capture, aggregate, and process an individual's data has grown significantly as digital technology has increasingly integrated into our daily lives. In the urban informatics context and in computational social science, projects use data collected about our behavior in the urban environment to solve problems including traffic congestion and public safety, the creation of targeted advertising, and the development of entire neighborhoods. Some projects using aggregate data may ultimately benefit individuals by making improvements to their environment at large. Although individuals are the source of aggregate information, an individual citizen often does not directly engage with the data collected about them. The research contained in this dissertation explores a series of visualization experiments concerning direct engagement between citizens and public datasets such as the U.S.Census. In order for such visualizations to be effective, they not only have to efficiently communicate data, but must also be intuitive, evocative, and utilize narratives presented from the user's perspective. In this dissertation I address the question: How can we design visualizations which inform daily interaction between individuals and public data about their environment? To answer this question, the dissertation introduces 4 sets of maps: (1) the Powers Map and Scopes Map contextualizes Census data(American Community Survey) by invoking changes in scale, (2) the Sightline Map and Cross Section Map use a person's physical experiences to orient Census data, (3) the Filtered Satellite Maps give qualitative comparisons of conditions described by Census tables, and (4) the Personal History Map leverages an individual's geospatial history to filter Census data. These 4 map groups share the goal of allowing us, as individuals, to use public data to design our own experiences within our environments and to make use of public data directly on our own behalf.
by Jia Zhang.
Ph. D.
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Leney, Katharine J. C. "Searches for Higgs bosons in the di-tau decay channels at the ATLAS experiment." Thesis, University of Liverpool, 2010. http://livrepository.liverpool.ac.uk/1459/.
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The search for the Higgs boson will be one of the primary tasks of the LHC. One of the most promising channels in the search for a low mass Higgs boson will be the scenario where the Higgs is produced via Vector Boson Fusion and subsequently decays to a pair of tau leptons. One of the dominant (and most complex) backgrounds to this analysis is expected to come from tt decays. Monte Carlo samples with a centre-of-mass energy of 14 TeV are used to investigate the contributions from different tt decay modes and to develop methods to reduce the contribution from this background process and improve the overall sensitivity of the analysis. A technique to estimate contributions from background processes when there are insufficient Monte Carlo samples available to calculate this directly is also presented. A low mass Standard Model Higgs boson will require at least 10 inverse femtobarns of data before a discovery (or exclusion) can be claimed, but extensions to the Standard Model that realise Supersymmetry predict that there should be three neutral Higgs bosons. The production cross-section is strongly enhanced and it is there- fore expected that competitive limits on an MSSM Higgs boson can be made using data from the 2010-2011 LHC data-taking period (1 inverse femtobarn expected with 7 TeV centre-of-mass collisions). A search strategy for an MSSM Higgs boson decaying to two taus is presented, focusing on ensuring analysis robustness during this early period. Comparisons with the first ATLAS data are also made.
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Wu, Xue. "Atlas based image reconstruction for diffuse optical imaging of the human brain." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6605/.
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Diffuse Optical Tomography (DOT) has been applied to imaging functional activations in the adult brain. Registered-atlas models are acceptable alternative forward models for the subject-specific models. In this work, different landmark-based rigid registration methods are quantitatively evaluated and compared in geometrical accuracy of the registration result, accuracy of light propagation approximation and recovery accuracy of the brain activations based on the whole head and localized head regions. The most suitable registration methods are selected based on accuracy and efficiency and they vary based on region of interest. For example, the most suitable registration method for recovery of whole cortex activation is the registration method based on 19 landmarks from the EEG 10/20 system and non-iterative Point to Point algorithms (EEG19nP2P registration). Efficiency of the recovery process is another popular research area in DOT. In this work, a modified generation approach of the light propagation approximation is designed based on a reduced sensitivity matrix and parallelisation process. It improves the storage efficiency by >1000% and time efficiency by ~400%. Based on this approach, the brain activation recovery of DOT can be processed on a normal laptop without large memory requirements within 45 minutes which is more suitable for a portable system.
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Szadaj, Antek. "Performance studies of Low-Gain Avalanche Diodes for the ATLAS High-Granularity Timing Detector." Thesis, KTH, Fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-240145.
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Schwoerer, Maud. "'Etudes des états finals diphoton dans l'expérience ATLAS au LHC : mesure de section efficace différentielle, découverte d'une nouvelle résonance dans la recherche du boson de Higgs et étude de ses propriétés'." Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00978539.
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Cette thèse sera centrée sur les analyses des événements diphotons dans le détecteur ATLAS. L'activité évoluera au cours du temps et couvrira différents aspects: compréhension de la réponse du détecteur, participation a la prise de données, analyse physique et recherche de signaux de physique au-delà du modèle standard.
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Freeland, Debra Jeanette. "ODYSSEUS RE-IMAGINED: EXPERIMENTAL FICTION RESPONDS TO THE CALL OF THE ANCIENTS- TECHNOLOGY AND SCIENCE FULFILL CLASSIC EPIC DEVICES IN CLOUD ATLAS AND THE SILENT HISTORY." CSUSB ScholarWorks, 2019. https://scholarworks.lib.csusb.edu/etd/929.
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The timeless, lyrical poem of Ancient Greece, revered for its grand battles, supernatural forces and legendary heroes is a fading memory of a forgotten past. Many critics, scholars, and authors like Theodore Steinberg concur, “. . . “[the] twentieth-century epic” is oxymoronic, the epic died with Milton” (10). Yet, the echoes of the past resound in the present as the characteristics and literary conventions of the Homeric epic are easily found in contemporary genres, including fantasy, sci-fi, and dystopian fiction. What has emerged is not a repeat of the past, but something different, something new. The influence of science and technology is apparent even to the most relaxed reader. Contemporary writers have adapted forms of technology, communication, and modern science to perform as the traditional literary devices of the epic genre.
In his book, Epic in American Culture, Christopher N. Phillips remarks that ,”Epic did not die with Milton . . . it developed new power and shape. . .” as writers dismissed the traditional formats to allow for artistic growth advancing the use and understanding of epic, “. . . the new insights, literary and cultural history that emerge once synchronic, monolithic definition of form are abandoned-the surprises in the archive of American literary engagements with the epic form are myriad” (4,10). This release of boundaries allowed space to create, one that intersects with specific moments in time and sociocultural influence, allowing the inclusion of modern understanding and experiences. I found a kernel in Catherine Morley’s book, The Quest for Epic, where she examines the influence of the epic on the American novel, and the means with which writers continue to approach and engage epic , “. . . compulsively and consciously appropriated and reinvented aspects of the antique and the modern European epic traditions to advance their own aesthetic designs” (13). Furthering the writer’s vision is only part of the epic’s adaptation, and the formulation of other genres, including sci-fi and fantasy, provide many reference points in its long evolutionary cycle. Why the need for new genres? What did writers have to address to warrant these spaces? Technology was one answer. Technological advancements placed a demand upon writers, stirring the authors to push against canonical boundaries. The cultural importance of the mythology surrounding the epic is infused, and the result is an expanded, (dare I say new?), technology rich, contemporary epic. Same genus, different species.
So, what does this new cutting-edge insertion look like? How does it function? What role does technology play in contemporary figuration's of the epic? How does modern science perform in ancient conventions? Can they maintain the ethos of the traditional Homeric epic? This thesis will investigate through literary scholarship and theory, Homer’s classics, Iliad and The Odyssey, and two contemporary novels, David Mitchell’s Cloud Atlas and The Silent History by Eli Horowitz, Matthew Derby, and Kevin Moffett.
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Sjöström, Fredrik. "Auto-triggering studies of Low Gain Avalanche Detectors for the ATLAS High-Granularity Timing Detector." Thesis, KTH, Fysik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-253905.
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Holmberg, Mei-Li. "Studies of Low Gain Avalanche Detector prototype sensors for the ATLAS High-Granularity Timing Detector." Thesis, KTH, Fysik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-253906.
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Vik, Torbjorn. "Modèles statistiques d'apparence non gaussiens. Application à la création d'un atlas probabiliste de perfusion cérébrale en imagerie médicale." Phd thesis, Université Louis Pasteur - Strasbourg I, 2004. http://tel.archives-ouvertes.fr/tel-00008583.
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La tomoscintigraphie par émission mono-photonique (TEMP) est une méthode d'imagerie fonctionnelle 3D qui apporte des informations sur le débit sanguin cérébral (également appelé perfusion cérébrale). Cette méthode d'imagerie, par la détection visuelle d'anomalies de perfusion caractérisées par des zones hypo- ou hyper-intenses, est utilisée pour le diagnostic chez des patients atteints d'accidents vasculaires cérébraux, de démence, d'épilepsie ou d'autres pathologies cérébrales. La détection d'anomalies focalisées observées chez les patients ayant une attaque cérébrale est relativement aisée, alors que les anomalies diffuses, observées en début de démence, lors d'un accident entraînant une oxygénation insuffisante du cerveau ou suite à une exposition à une substance toxique, sont plus difficilement observables. Dans ces cas, une analyse quantitative des images, utilisant un atlas et des outils statistiques s'appuyant sur une base d'images de cas normaux, peut apporter une aide précieuse au diagnostic. Le travail présenté dans cette thèse est centré sur la problématique de la construction et de l'évaluation d'un atlas probabiliste de perfusion cérébrale à partir des images TEMP de sujets dits normaux. Les objectifs d'un tel atlas sont doubles : (1) création d'une cartographie statistique de la perfusion cérébrale d'une population normale, décrite de manière compacte, et (2) identification des différences de perfusion cérébrale qui sont statistiquement significatives entre une image TEMP d'un individu et l'atlas probabiliste. L'utilisation d'un atlas devrait avoir un impact important sur les applications cliniques où l'analyse qualitative d'images TEMP est pratique courante. Afin d'atteindre ces objectifs, trois points ont été abordés : le développement de modèles statistiques qui décrivent de façon fidèle la perfusion cérébrale, les outils de traitement d'images utilisés pour rendre les cerveaux "comparables", et enfin, l'évaluation expérimentale de l'atlas.
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Lu, Tiffany T. "Integrating physical objects Into digital displays : design of a 3D campus map for the MIT Atlas Center." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/105980.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (page 57).
An emerging trend in consumer technology has been to build smarter technology into physical objects and to control those objects through digital interfaces. This blend of different interfaces for the internet of things reflects a response to a need for integrating technology more deeply into everyday life and providing more intuitive and natural interfaces. As these technologies advance, the line between digital information and physical objects will blur. This project explores how physical objects can be integrated into digital interfaces through the development of an interactive 3D campus map, a component of the new MIT Atlas Service Center. The installation combines physical objects with a large touch screen table in order to create a blended engaging experience. Through the design of both the experience and interface of the installation, we explore how digital information and physical objects can work together to help people understand spatial and contextual information. The campus map allows users to explore various aspects of MIT culture from basic navigational information to the latest MIT research to what's going on around campus right now, and also provides a modular platform for any location-based data visualization.
by Tiffany T. Lu.
M. Eng.
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Gutierrez, Ortiz Nicolas Gilberto. "Top-tagging with shower deconstruction and search for single production of vector-like quarks at ATLAS." Thesis, University of Glasgow, 2015. http://theses.gla.ac.uk/6714/.
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The identification of high transverse momentum top quarks is an essential ingredient of many searches for new physics. This thesis presents, for the first time, the performance of shower deconstruction, a new top-tagging algorithm, using data collected with the ATLAS detector at the LHC. The distribution of the shower deconstruction observable, the likelihood ratio χSD, is shown to be very well modelled by modern Monte Carlo generators, and is compared to several other algorithms and jet substructure observables. Shower deconstruction is shown to have the best quark- and gluon-jet background rejection over a wide range of signal efficiency. Vector-like quarks are a feature of several new physics models. As they do not gain their mass from a Yukawa coupling, they are still allowed by constraints set by Higgs production cross section measurements. These, so-called, fermionic-partners can play a role similar to that of bosonic-partners in supersymmetric models, providing a solution for the naturalness problem. This thesis presents the first dedicated search for single production of vector-like quarks, using data collected with the ATLAS detector, introducing novel strategies for separating signal from background. This work extends the exclusion limits from production of pairs of vector-like quarks, from 700 GeV to 950 GeV, for suitably large vector-like quarks couplings. Also, exclusion limits on the coupling versus vector-like quark mass space are presented for the first time. Large-R jet triggers are first introduced in ATLAS during Run 1 to cover topologies where these jets play a predominant role. In this thesis, several performance metrics of these triggers are presented, using data collected with the ATLAS detector, highlighting their advantages over standard jet triggers. Also, an example of how these triggers can be combined to lepton triggers to increase the efficiency of a search for new physics is shown.
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Martin, Sébastien. "Utilisation d'atlas anatomiques et de modèles déformables pour la segmentation de la prostate en IRM." Phd thesis, Grenoble 1, 2008. http://www.theses.fr/2008GRE10287.
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Le principal objectif de cette thèse est le développement d'outils permettant le contourage automatique de la prostate en IRM. Dans un futur proche, ces outils s'intègreront à des systèmes informatiques permettant d'assister le clinicien dans la réalisation du geste de curiethérapie de la prostate. Notre méthode se base sur l'utilisation d'un atlas anatomique et de modèles déformables pour réaliser une segmentation automatique de la prostate. La méthode se déroule suivant une approche hiérarchique en 3 étapes permettant d'intégrer efficacement différents types de connaissances a priori. Une première étape de pré-traitements permet la correction des très fortes inhomogénéités d'intensités caractéristiques des images IRM acquises par l'intermédiaire de sondes endorectales. Dans une seconde étape, l'anatomie du patient est mise en correspondance avec un atlas anatomique ; ce qui permet d'obtenir une première segmentation du rectum et de la prostate. Enfin, dans une dernière étape, deux modèles déformables évoluent successivement pour raffiner les segmentations précédemment obtenues. Dans un premier temps, le rectum est segmenté suivi de la prostate. L'intégration du rectum dans le processus de segmentation permet de contraindre l'évolution du modèle déformable de la prostate. L'atlas anatomique utilisé est construit grâce à un algorithme de recalage hybride permettant la mise en correspondance d'une population sur une référence. L'algorithme hybride en exploitant conjointement des informations géométriques et iconiques permet la construction d'atlas qui se sont avérés plus performants que ceux construits par un recalage iconique purIn this thesis we focus on the development of tools for the automatic segmentation of the prostate gland in Magnetic Resonance Images. In a near future, these tools will be used to help clinicians for prostate brachytherapy. Our method is based on the use of both an anatomical atlas and deformable models to achieve an automatic segmentation. We use a hierachical approach composed of three steps. In the first step, a pre-processing of input images is performed to correct the inhomogeneity of images acquired with an endorectal MRI coil. In the second step, the target patient is registered onto an anatomical atlas ; this step allows for a first segmentation of the prostate and of the rectum. In the last step, two deformable models evolve to refine segmentations obtained in the previous step. The segmentation of the rectum is executed first. In a second time, a deformable model evolves to segment the prostate. The segmentation of the rectum is used to constrain the evolution of the prostate deformable model. The anatomical atlas is built using a hybrid registration method. The later both exploits geometric and intensity-based information for mapping a population onto a standard patient. We have shown that this strategy improves the accuracy of obtained automatic segmentations
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Martin, Sébastien. "Utilisation d'atlas anatomiques et de modèles déformables pour la segmentation de la prostate en IRM." Phd thesis, Université Joseph Fourier (Grenoble), 2008. http://tel.archives-ouvertes.fr/tel-00374342.
Full textAbstract:
Le principal objectif de cette thèse est le développement d'outils permettant le contourage automatique de la prostate en IRM. Dans un futur proche, ces outils s'intègreront à des systèmes informatiques permettant d'assister le clinicien dans la réalisation du geste de curiethérapie de la prostate. Notre méthode se base sur l'utilisation d'un atlas anatomique et de modèles déformables pour réaliser une segmentation automatique de la prostate. La méthode se déroule suivant une approche hiérarchique en 3 étapes permettant d'intégrer efficacement différents types de connaissances a priori. Une première étape de pré-traitements permet la correction des très fortes inhomogénéités d'intensités caractéristiques des images IRM acquises par l'intermédiaire de sondes endorectales. Dans une seconde étape, l'anatomie du patient est mise en correspondance avec un atlas anatomique ; ce qui permet d'obtenir une première segmentation du rectum et de la prostate. Enfin, dans une dernière étape, deux modèles déformables évoluent successivement pour raffiner les segmentations précédemment obtenues. Dans un premier temps, le rectum est segmenté suivi de la prostate. L'intégration du rectum dans le processus de segmentation permet de contraindre l'évolution du modèle déformable de la prostate. L'atlas anatomique utilisé est construit grâce à un algorithme de recalage hybride permettant la mise en correspondance d'une population sur une référence. L'algorithme hybride en exploitant conjointement des informations géométriques et iconiques permet la construction d'atlas qui se sont avérés plus performants que ceux construits par un recalage iconique pur.
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Bitadze, Alexander. "Thermo-dynamical measurements for ATLAS Inner Detector (evaporative cooling system)." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/5186/.
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During the construction, installation and initial operation of the Evaporative Cooling System for the ATLAS Inner Detector SCT Barrel Sub-detector, some performance characteristics were observed to be inconsistent with the original design specifications, therefore the assumptions made in the ATLAS Inner Detector TDR were revisited. The main concern arose because of unexpected pressure drops in the piping system from the end of the detector structure to the distribution racks. The author of this theses made a series of measurements of these pressure drops and the thermal behavior of SCT-Barrel cooling Stave. Tests were performed on the installed detector in the pit, and using a specially assembled full scale replica in the SR1 laboratory at CERN. This test setup has been used to perform extensive tests of the cooling performance of the system including measurements of pressure drops in different parts of system, studies of the thermal profile along the stave pipe for different running conditions / parameters and coolant flow measurements in the system. The pressure drops in the system and the associated temperatures in the barrel cooling loops have been studied as a function of the system variables, for example; input liquid pressure, vapour back pressure, module power load and input liquid temperature. Measurements were performed with 10, 11, 12, 13 barabs inlet liquid pressure in system, 1.2, 1.6, 2.0, 2.5, 3.0, 4.0, 5.0, 6.0 barabs vapour back pressure in system, and 0 W, 3 W, 6 W, 9 W, 10.5W power applied per silicon module. The measurements clearly show that the cooling system can not achieve the design evaporation temperature of -25C in every part of the detector (SCT Barrel loops) in case of 13 barabs nominal inlet liquid pressure, 1.2 barabs minimum possible back pressure and 6W nominal power per SCT Barrel silicon module and especially at the end of the ATLAS ID operation period when modules will work on full power of 10.5 W. This will lead to the problem of thermal run-away of the ATLAS SCT, especially near the end of the operational period after significant radiation exposure has occurred. The LHC luminosity profile, depletion voltage and leakage current values and the total power dissipated from the modules were revised. Thermal runaway limits for the ATLAS SCT sub-detector were also revised. Results show that coolants evaporation temperature necessary for the sub-detector's safe operation over the full lifetime (10 years) is -15C with a safety factor of 2. Laboratory measurements clearly show that the cooling system can not achieve even this necessary evaporation temperature of -15C. It is now impossible to make mechanical modifications to the cooling system, for example; changing the diameter of the cooling pipes, or the thermal performance of the in-system heat exchanger or reducing the vapour back pressure. It was therefore decided to investigate changes to the cooling fluid and to test mixtures of Hexafluoroethane (R116) C2F6 and Octafluoropropane(R218) C3F8 at differing ratios instead of just pure C3F8 coolant presently used. For this purpose, a new "blending" machine was assembled in the SR1 laboratory, with a new device an "on-line acoustic flow meter and fluorocarbon coolant mixture analyzer" (Sonar Analyzer) attached to it. The Machines were connected to the already existing laboratory test station and new extensive tests were performed to investigate different proportion of C3F8/C2F6 blends to find the mixture ratio which resulted in the best operational performance as measured by: the temperature distribution, pressure drops and flow parameters over the system, to ensure best cooling performance of SCT Barrel cooling loops for long term ATLAS SCT operation. Measurements were performed with different percentage of C2F6 (1%, 2%, 3%, 5%, 10%, 20%, 25%) coolant in the C3F8/C2F6 mixture, for different power (0 W, 3 W, 6 W, 9 W, 10.5W) applied to dummy modules on the SCT cooling stave, with 13 barabs inlet liquid pressure and for different vapour back pressures (1.2, 1.6, 2.0, 2.5, 3.0 barabs) in the system. Results prove that with 25% of C2F6 in the blend mixture, it is possible to lower the evaporation temperature by ~10C in the case of nominal operation parameters of the system. The ATLAS Inner Detector Evaporative Cooling System can therefore reach the necessary evaporation temperature and therefore can guarantee thermal stability of the SCT, even at the end of the operation period.
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Laamrani, El Idrissi Ahmed. "Recherche par télédétection géologique de sites potentiels d'hydrocarbures dans l'Anti-Atlas marocain." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ37783.pdf.
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Kuwertz, Emma. "A search for supersymmetry in di-lepton final states using the razor variables with the ATLAS detector." Licentiate thesis, KTH, Partikel- och astropartikelfysik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103025.
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Moreno-Fortuny, Gabriel. "Generating Radiosity Maps on the GPU." Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/1081.
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Global illumination algorithms are used to render photorealistic images of 3D scenes taking into account both direct lighting from the light source and light reflected from other surfaces in the scene. Algorithms based on computing radiosity were among the first to be used to calculate indirect lighting, although they make assumptions that work only for diffusely reflecting surfaces. The classic radiosity approach divides a scene into multiple patches and generates a linear system of equations which, when solved, gives the values for the radiosity leaving each patch. This process can require extensive calculations and is therefore very slow. An alternative to solving a large system of equations is to use a Monte Carlo method of random sampling. In this approach, a large number of rays are shot from each patch into its surroundings and the irradiance values obtained from these rays are averaged to obtain a close approximation to the real value. This thesis proposes the use of a Monte Carlo method to generate radiosity texture maps on graphics hardware. By storing the radiosity values in textures, they are immediately available for rendering, making this algorithm useful for interactive implementations. We have built a framework to run this algorithm and using current graphics cards (NV6800 or higher) it is possible to execute it almost interactively for simple scenes and within relatively low times for more complex scenes.
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Pasuwan, Patrawan. "Measurements of luminosity and a search for dark matter in the ATLAS experiment." Licentiate thesis, Stockholms universitet, Fysikum, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-193096.
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This licentiate thesis presents contributions to the luminosity measurement from the data recorded by the ATLAS detector in 2017 using a track-counting technique, as well as a search for dark matter in the ATLAS experiment using 139 fb-1 of √s = 13 TeV pp collision data delivered by the LHC from 2015 to 2018. Track-counting luminosity measurements in low-luminosity operations are performed to study the effect of low collision rates on luminosity determination. The luminosity measured in a calibration transfer procedure using the track-counting technique is used to correct the pile-up dependence observed in ATLAS’s main luminosity detector called LUCID. A search in the final state of a lepton, jets and missing transverse energy, where the final state is produced from a pair of top quarks and a spin-0 scalar/pseudoscalar mediator, is presented. A dedicated signal region is designed to target this final state in which the mediator decays into dark matter particles. The signal region covers the search in the mass plane of the mediator and the dark matter particle. Dedicated control regions are designed to estimate the top-quark background events, as well as the events where a Zboson is produced in association with the top quarks. The signal region event counts in the data have not been unblinded yet, but expected exclusion limits at 95% confidence level as a function of mediator mass are presented. Scalar and pseudoscalar mediators are expected to be excluded up to 200 and 250 GeV, respectively, for the dark matter mass of 1 GeV, and the coupling strengths of the mediator to the dark matter and Standard Model particles of 1.
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Little, Francesca. "The smooth is better than the rough : an exploitation of reporting rate information in Southern Africa bird atlas data." Doctoral thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/8592.
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Includes bibliographical references.The Southern African Bird Atlas Project (Harrison at el. 1997a, b) and the Mozambique Bird Atlas Project (Parker 1999) generated data on reporting rates for birds that takes into account the likelihood of species detection in a given area. Our main objective in this thesis is to explore methods for analysing and summarising reporting rate data. The observed reporting rate data are subject to bias due to differential sampling effort and observer errors. We use a logistic regression model suitable for binomial type data to replace the observed reporting rates with smoothed probabilities of detection. To base our prediction on data from the surrounding neighbourhood, we choose as explanatory variables the north-south and west-east coordinates relative to the target grid cell for which the prediction is being made. We explore some variants of our general smoothing approach that relates to the presentation of the smoothed distributions. The smoothed distributions of detection probabilities are presented as multicoloured maps. We consider two alternative ways of subdividing the range of detection probabilities into sub-intervals. One approach is species-specific, while the other imposes an absolute subdivision on all species distributions. For species with highly fragmented distributions, we introduce the possibility of using a weighted average between observed reporting rates and smoothed detection probabilities as the final value to be plotted. The weights are based on the extent of coverage and the underlying degree of fragmentation. The identification of patterns of distributions for species is an important part of biogeography and plays a major role in the identification of areas where conservation efforts should be targeted. Interest centres around identifying areas of species richness, centres for narrow eudemism and zones of transition in species composition. We explore the benefits of using a range of detection probabilities in comparison to the use of presence-absence data to identify areas rich in species and rich in narrow-endemic species. We transform existing measures for species richness and species endemism by replacing presence-absence data with detection probability deciles that reflect the relative likelihood of detecting a species in a given grid cell. The resulting measures give more weight to the areas where species have the core of their distributions and down-weight the peripheral edges of the species distributions, where detection probabilities may be too small to guarantee continued survival. The use of a mathematical model to generate smoothed distributions of detection probabilities enables us to calculate gradients for the detection probability surfaces for species. We can define the concept of individual species gradients that reflect the relative degree of change among detection probabilities within the overall range of occurrence for the species. We combine the gradients for all species in several different ways. Large values for the overall sums of the gradients indicate areas of large fluctuation in species composition. On the other hand, small values for the overall gradient sums indicate areas of relative stability. We also sum the gradients in one of 16 directions. These directional gradient sums distinguish between areas where the changes in species detection probability distributions occur in isolated directions, thus indicating ecological transition zones, and areas of random fluctuation, indicative of species fragmentation. In this thesis we do not derive new statistical methods. We adapt existing techniques to deal with the abundance component of the data generated by the bird atlas projects. We show how the measures based on reporting rate data, rather than presence-absence data, add substantial insight into patterns of distribution of bird species in southern Africa.
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Bessidskaia, Bylund Olga. "Top quark and heavy vector boson associated production at the ATLAS experiment : Modelling, measurements and effective field theory." Doctoral thesis, Stockholms universitet, Fysikum, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-147262.
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The Standard Model (SM) of particle physics describes the elementary particles that constitute matter and their interactions. The predictions of the SM have been confirmed by numerous experimental results. However, several questions of particle phenomena in the Universe remain unaddressed by the Standard Model, which suggests that the SM can be extended to a more complete theory. One approach to search for extensions of the SM is to test the predictions of the Standard Model in high precision measurements and see whether the results falsify the SM. For this reason, production of the ttZ and ttW processes at the ATLAS experiment at CERN is studied. It is investigated whether the SM gives correct predictions for these processes and how much room there is for contributions from new physics that give similar final states. Three measurements of ttZ and ttW production are performed. The first measurement is performed at 8 TeV collision energy. The next measurement uses data collected in 2015 at 13 TeV collision energy, when the production cross sections for these processes are considerably larger. The third measurement uses ten times as much data at 13 TeV collision energy. This analysis is not public at the time of writing, so only preliminary results for the expected sensitivity are presented. The new physics affecting ttZ production is parametrised in the model-independent framework of Effective Field Theory. Five effective operators that can affect ttZ production are studied and their coefficients are constrained in a fit to simulated data for the third measurement. The major background process tWZ is modelled at NLO in QCD. In order to avoid overlaps with ttZ, the Diagram Removal (DR) method is employed in two versions: one where the quantum interference is neglected (DR1) and another where it is modelled (DR2). The differences between the two predictions are explored and enter the measurement as a modelling uncertainty.
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Jovicevic, Jelena. "Probing the Standard Model Higgs boson in the WW decay mode with the ATLAS detector at the LHC." Licentiate thesis, KTH, Partikel- och astropartikelfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-120272.
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This thesis is concerns an analysis to probe the Higgs boson in the H→WW(*)→lvlv decay mode, one of three analyses contributing to the discovery of the Higgs boson at a mass of mH = 125 GeV in July 2012. The dataset used are the proton-proton collisions collected with the ATLAS detector at the CERN Large Hadron Collider during 2012 at a centre of mass energy of 8 TeV, and correspond to a total integrated luminosity of 13.0 fb-1. An excess of events is observed in the data over the expected number of background events. The significance of the excess is estimated to be 2.8 standard deviations and the signal strength, defined as a ratio of the observed cross-section for the signal to the cross section predicted for a Standard Model Higgs boson with a mass of 125 GeV, is measured to be υ = 1:5 ± 0:6. At present, all results in the H→WW(*)→lvlv decay mode concerning the newly discovered particle are compatible with the expectations from the Standard Model for a Higgs boson with a mass of mH = 125 GeV. In addition, an optimisation of the thresholds used to check the stability of the electronics calibration constants in the ATLAS Liquid Argon Calorimeter is presented. The calibration constants enters the calculation of the energy of the individual cells in the calorimeter and have to be validated regularly. The study is performed on calibration data from 2010 and 2011. New thresholds, based on the statistical behavior of the calibration constants, are determined separately for the different calorimeter regions.QC 20130404
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Labhar, Mohamed. "Les milieux forestiers et pré-forestiers du moyen atlas central nord-occidental :approche géographique, phytoécologique et dynamique." Doctoral thesis, Universite Libre de Bruxelles, 1998. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212025.
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Bourget, Emilie. "Télédétection et atlas de paysages : approche multiscalaire des paysages en Bretagne." Phd thesis, Université Rennes 2, 2011. http://tel.archives-ouvertes.fr/tel-00670229.
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A l'échelle de la Bretagne comme de la France, la gestion et la protection des paysages passe en premier lieu par leur connaissance, ainsi que le stipule la Convention Européenne du Paysage (2000). La présente recherche propose une approche objectivée du paysage, considéré comme une partie visible du territoire, dont les caractères peuvent s'étudier àdifférentes échelles. Un état de l'art de la définition et de la cartographie des unités paysagères permet tout d'abord de passer en revue les différentes approches, scientifiques et plus usuelles, de la délimitation des paysages, et conduit à proposer une méthode alliant traitements d'une classification pixel à moyenne résolution spatiale et connaissances expertes, afin de produire un découpage harmonisé des ensembles paysagers à l'échelle régionale. Une seconde méthodologie basée sur le traitement " orienté-objet " de données télédétectées à haute résolution spatiale aboutit ensuite à la définition des unités paysagères à l'échelle infradépartementale sur deux zones d'étude (le Pays de Saint-Brieuc et l'ensemble paysager des Landes de Lanvaux), et à l'approche renouvelée du traitement des limites de ces unités :l'utilisation de buffers permet d'établir une typologie quantitative de ces limites, du passage franc au continuum paysager. Enfin, l'analyse paysagère et les cartographies produites dans les deux premières parties de la réflexion sont appliquées, dans une optique écopaysagère, à la problématique actuelle de délimitation des Trames Vertes et Bleues impulsée par le Grenelle de l'Environnement ; elles peuvent constituer un socle de réflexion dans la caractérisation des réseaux écologiques par l'approche " habitat ", mais également permettre spécifiquement une délimitation plus fine des paysages de vallées, dans une optique d'aide à la décision dans ces politiques publiques
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Ray, Cyril. "ATLAS, une plate-forme pour la modélisation et la simulation de systèmes désagrégés." Phd thesis, Université Rennes 1, 2003. http://tel.archives-ouvertes.fr/tel-00090373.
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Cette thèse introduit une méthodologie composée d'une démarche de modélisation et d'un support informatique pour la simulation distribuée et l'analyse de systèmes complexes à larges flux de données désagrégées. Le choix méthodologique proposé est influencé à la fois par le système à simuler et par l'architecture informatique servant de support de simulation dans le but de proposer une solution où l'aspect technique soit en accord avec l'aspect conceptuel. La démarche de modélisation intègre une description hiérarchique représentant l'organisation interne d'un système complexe, la construction d'un graphe logique traduisant une décomposition structurelle du système. Le graphe logique est ensuite utilisé pour réaliser une projection qui produit un graphe physique établissant une abstraction qui lie le niveau de représentation conceptuel et le système distribué sous-jacent. La plate-forme Atlas est un support de simulation distribuée à événements discrets dirigée par le temps et dont les propriétés dynamiques reproduisent le comportement de larges flux de données désagrégées. Une des particularités de cette plate-forme réside dans le concept de migration physique par groupe qui donne une solution adaptée pour réaliser et coordonner la migration de larges flux d'objets. Cette migration par groupe possède de nombreux avantages pour la simulation de systèmes sociétaux et urbains, notamment pour les systèmes en transport. L'utilisation de notre méthodologie et de sa plate-forme est illustrée par une application en transport qui modélise et simule les flux de personnes entre les différents halls d'un terminal d'aéroport.
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Thouvenot, François. "Aspects géophysiques et structuraux des Alpes occidentales et de trois autres orogènes (Atlas, Pyrénées, Oural)." Phd thesis, Université Joseph Fourier (Grenoble), 1996. http://tel.archives-ouvertes.fr/tel-00739809.
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La sismologie et les grands profils sismiques sont ici plus particulièrement utilisés pour étudier la structure profonde de quatre orogènes. Pour les Alpes occidentales, nous traitons d'abord de l'atténuation intrinsèque des ondes sismiques dans la croûte supérieure et de sa dépendance en fonction de la fréquence. Nous faisons ensuite le point sur l'état des connaissances sur l'allochtonie et l'écaillage Iithosphérique vers le milieu des années quatre-vingt. C'est en effet à cette époque que le profil Ecors-Crop Alpes à permis de davantage détailler la structure de la croûte par sismique réflexion verticale En sismique réflexion grand-angle, on a pu observer le Moho profond de la zone de racine et, dans le domaine briançonnais, une écaille de manteau imbriquée dans la croûte alpine. La sismicité et la sismotectonique des Alpes occidentales sont ensuite examinées à la lumière des données récemment acquises par le réseau Sismalp qui surveille l'activité du Sud-Est de la France. Les données télésismiques obtenues par ce même réseau ont été utilisées pour procéder à une tomographie télésismique de la limite de plaques Eurasie-Adriatique jusqu'à 200 km de profondeur. Les trois autres orogènes sont étudiés de façon plus succincte. La structure profonde de l'Atlas tunisien est d'abord présentée à travers les résultats d'une campagne de sondages sismiques profonds. Nous avons ensuite appliqué aux coupes de sismique réflection verticale du profil Ecors Pyrénées les techniques de migration mises au point dans les Alpes. Nous concluons par l'étude de la partie centrale de l'Oural par sismique réflexion grand-angle et par tomographie télésismique, deux techniques éprouvées précédemment dans les Alpes.
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Binet, S. "Environnement logiciel et étalonnage de l'échelle en énergie des jets dans l'expérience ATLAS." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2006. http://tel.archives-ouvertes.fr/tel-00140524.
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Ce document présente le travail réalisé pour doter l'environnement logiciel de la collaboration ATLAS, ATHENA, d'une bibliothèque d'outils pour l'analyse de physique ainsi que pour l'extraction d'une fonction d'étalonnage de l'énergie des jets à partir d'évènements de physique (étalonnage in-situ).La partie logicielle expose les différents composants de l'architecture logicielle qui a la gestion du flot de données simulées et reconstruites, ainsi que les différentes étapes de ce flot, avant et pendant la prise de données. La construction d'une bibliothèque d'outils facilitant la reconstruction d'objets physiques, leur association avec les entités Monte-Carlo et les interfaces de programmation de ces objets est ensuite détaillée, l'accent étant mis sur l'importance d'avoir un langage et des outils communs à l'ensemble de la collaboration afin de partager l'effort de validation de ces outils et ainsi obtenir des résultats de physique reproductibles.
Dans la partie analyse, l'implémentation dans le framework ATHENA d'un algorithme d'étalonnage de l'énergie des jets légers en utilisant la désintégration de bosons W en une paire de jets est traitée. A partir de l'application de cet algorithme sur des données simulées via la simulation rapide et la simulation complète, il semble envisageable de connaître l'échelle en énergie des jets légers à hauteur du pour-cent. Enfin, l'étude de faisabilité de l'extraction de l'échelle en énergie des jets de b en utilisant le processus γZ° \to γb barb est exposée. Il est montré que l'application de coupures séquentielles ne permet pas d'extraire le signal par rapport au bruit de fond. Cependant, une approche multivariable pourrait améliorer la sélection, permettant de collecter un nombre suffisant de paires Z° pour réaliser l'étalonnage en énergie des jets de b.
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Elyoussi, Mohammed. "Sédimentologie et paléogéographie du Permo-Trias du Haut Atlas central (Maroc)." Phd thesis, Grenoble 1, 1986. http://tel.archives-ouvertes.fr/tel-00705637.
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La série permotriasique du Haut-Atlas Central (Maroc) est étudiée sous divers aspects: L'étude stratigraphique, sédimentologique et paléontologique a permis de diviser cette série en six formations: F1 et F2 attribuées au Permien par analogie latérale. de faciès, de type torrentiel de comblement de bassins locaux; F3 d'âge difficile à préciser, la sédimentation est toujours continentale, mais de glacis, à croûtes et sols carbonatés; F4, F5 (elle-même subdivisée en trois membres F5a, F5b, F5c) et F6 d'age trias supérieur: l'étude paléontologique de plusieurs gîtes fossilifères (Lamellibranches, pollens, gymnospermes, traces de pas de vertébrés) précisent l'âge Carnien supérieur (= Tuvalien) du membre F5a. Le dépôt est marin littoral. Une tectonique synsédimentaire distensive, héritée de la tectonique hercynienne est mise en évidence. L'analyse des paléocourants, la typologie des zircons et l'étude pétrographique, ont permis de situer l'origine des sédiments dans un secteur localisé au Sud, Sud-Est et à l'Est du bassin étudié, plus précisément dans l'Anti-Atlas.
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Jouhari, Abdellatif. "Minéralisations à Au-Mo-Cu de la bordure orientale du massif du Tichka dans leur cadre géologique (Haut-Atlas occidental, Maroc)." Phd thesis, Grenoble 1, 1989. http://tel.archives-ouvertes.fr/tel-00703272.
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Le massif du Tichka représente un des plutons "granitiques" hercynien du Maroc. Il est situé dans le Haut-Atlas occidental à environ 100 km au SW de Marrakech. Cette étude a montré que la partie orientale ainsi que les apophyses qui émanent de celle-ci sont caractérisées par la présence de cinq groupes pétrographiques (diorites. diorites quartziques, granodiorites. monzogranite et granitoïdes) tandis que son encaissant est fait d'une série volcano-sédirnentaire d'âge paléozoïque(Cambrien inférieur). L'ensemble a été structuré et métamorphisé lors de l'orogenèse hercynienne. L'origine du pluton reste l'objet de plusieur hypothèses(origine purement crustale ou origine double à la fois crustale et rnantéllique). Bien que limitée à la prise en considération des termes acides (qui affleurent dans la partie orientale) les argurnents géochimiques apportés dans la présente étude (éléments traces) plaident davantage pour la second hypothèse. On a montré aussi que le volcanisme du Cambrien inférieur est de nature calco-alcaline. Concernant les minéralisations,l' accent a été porté plus particulièrement sur les indices à molybdène (secteur d'!kissane), à cuivre (secteur du Tizi n'Israquen) et surtout à or (secteur d'Oukilal). Outre la description minéralogique détallée de ces indices (avec notamment la description d'un nouveau sulfure d'or, bismuth et plomb) à Oukilal, cette étude a permis de poser le problème de la genèse des minerais. Deux phases successives ont été reconues dans la mise en place de la minéralisation à molybdène. Une première phase (riche en molybdénite) à gangue quartzo-feldspathique, une seconde (moins riche) à gangue uniquement quartzeuse. Pour le cuivre,on a pu mettre en évidence l'existence d'une zonation verticale à l'intérieur des filons. Elle peut correspondre à des modifications physico-chimiques du fluide ascendant. Concernant l'or, trois stades de minéralisation ont été reconnus: le premier à mispickel (peu aurifère) surtout, le second à pyrrhotite (peu aurifère) plus pyrite, le troisième à paragenèse beaucoup plus complexe incluant notamment les élémenlts Cu, Pb, Zn, Bi, Te et Au. Ce troisième stade correspond à une fissuration tardive liée à la tectonique hercynienne. C'est lui qui a donné lieu à la cristallisation du sulfure d'or, bismuth, plomb signalé précédemment.
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Parisot, Sarah. "Understanding, Modeling and Detecting Brain Tumors : Graphical Models and Concurrent Segmentation/Registration methods." Phd thesis, Ecole Centrale Paris, 2013. http://tel.archives-ouvertes.fr/tel-00978520.
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The main objective of this thesis is the automatic modeling, understanding and segmentation of diffusively infiltrative tumors known as Diffuse Low-Grade Gliomas. Two approaches exploiting anatomical and spatial prior knowledge have been proposed. We first present the construction of a tumor specific probabilistic atlas describing the tumors' preferential locations in the brain. The proposed atlas constitutes an excellent tool for the study of the mechanisms behind the genesis of the tumors and provides strong spatial cues on where they are expected to appear. The latter characteristic is exploited in a Markov Random Field based segmentation method where the atlas guides the segmentation process as well as characterizes the tumor's preferential location. Second, we introduce a concurrent tumor segmentation and registration with missing correspondences method. The anatomical knowledge introduced by the registration process increases the segmentation quality, while progressively acknowledging the presence of the tumor ensures that the registration is not violated by the missing correspondences without the introduction of a bias. The method is designed as a hierarchical grid-based Markov Random Field model where the segmentation and registration parameters are estimated simultaneously on the grid's control point. The last contribution of this thesis is an uncertainty-driven adaptive sampling approach for such grid-based models in order to ensure precision and accuracy while maintaining robustness and computational efficiency. The potentials of both methods have been demonstrated on a large data-set of heterogeneous Diffuse Low-Grade Gliomas. The proposed methods go beyond the scope of the presented clinical context due to their strong modularity and could easily be adapted to other clinical or computer vision problems.
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Nedjahi, Abdellah. "La cedraie de chrea (atlas Blidéen) : Phénologie, productivité, régénération." Nancy 1, 1988. http://www.theses.fr/1988NAN10196.
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Étude des caractéristiques écologiques, phénologiques et dendrométriques du cèdre de l'atlas. Évaluation de la production et de la productivité ligneuse de cette cédraie. Définition de son potentiel de régénération naturelle et de ses possibilités d'extension
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Lundholm, Jonathan. "Plattformsoberoende widgets med giljotinpackade bakgrundstexturer." Thesis, Linköpings universitet, Programvara och system, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-107639.
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Vi har i detta arbete skapat ett API för widgets på Android och iOS för Visiarcs utvecklingsverktyg CoffeeMaker. CoffeeMaker använder sig av multiplattform-API:t Cocos2dx och försöker, i så stor utsträckning det är möjligt, förhålla sig till det reaktiva programmeringsparadigmet. Vi använde oss av olika designmönster för att jämna ut skillnaderna mellan Android och iOS interface och implementerade funktionalitet för knappar, checkboxes, radioknappar och textfält på dessa två plattformar. Dessa widgets tematiseras enligt ett JSON-liknande format och använder sig av en texturatlas för att spara resurser. Vi behövde en texturpackare som lämpade sig att köras under en applikations initiering och ibland även under själva körningen. Vi fann en snabb heuristik, O(n2), med god täthet, ca 94% enligt vår testmetod.We have in this work created an widgets API on Android and iOS for Visiarcs development platform CoffeeMaker. CoffeeMaker uses the multiplattform-API Cocos2dx and tries to use the reactive programming paradigm as much as possible. We used design patterns to try to smoothen out the differences between Android and iOS and implemented functionality for buttons, checkboxes, radiobuttons and textfields on these platforms. These widgets are themeble with a JSON-like format and uses a texture atlas to be sparse on system resources. We needed a texture packer which was suited to be run during runtime of a userspace application. We found a quick heurustic, O(n2), with good density, approximately 94% according to our test method.
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Lignereux, Yves. "Atlas stéréotaxique de l'encéphale de la vache frisonne (Bos Taurus L. )." Toulouse 3, 1986. http://www.theses.fr/1986TOU30147.
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Short, Daniel R. "A search for supersymmetry with the ATLAS detector using kinematic shape constraints in events containing one electron or muon." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:0c427106-4595-42d7-aa65-37f03fae7db7.
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The ATLAS experiment is used to observe the √s=7 TeV proton-proton collisions produced by the LHC at CERN. This gives an unprecedented opportunity to search for physics beyond the Standard Model at hitherto unexplored kinematic regimes. Supersymmetry (SUSY) provides interesting solutions to a variety of theoretical problems that may be encountered in the Standard Model at high energy scales, while providing signatures that may be observed at the LHC. However, in order to produce a search that is sensitive to SUSY it is vital to understand how the physics that has been discovered to date may produce signatures that mimic those expected from SUSY. Statistical models are constructed using both Monte Carlo and data-driven predictions of various background processes. The expectations are compared to the observed data for selections containing one electron or muon, each in association with jets and missing transverse momentum. Kinematic variable shapes, in the form of histograms, are used to enhance the sensitivity of the search. Squark and gluino masses in a MSUGRA SUSY model are excluded up to 1200 GeV, while gluino masses up to 900 GeV are excluded in a simplified SUSY model. Model-independent limits are also set, excluding theoretical models with efficiency times cross section above 1 fb.
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Eble, Florian. "Prospective study for the development of an analysis to measure the tri-linear Higgs coupling using the Matrix Element Method with the ATLAS experiment at the HL-LHC." Thesis, KTH, Fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-291100.
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Sunneborn, Gudnadottir Olga. "Exploring selections across channels in Dark Matter searches with top quarks at the ATLAS experiment of the LHC." Thesis, Uppsala universitet, Högenergifysik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-393949.
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Current estimates put Dark Matter to 26% of the energy-matter content of the universe, but very little is known about it other than its gravitational interactions. Eorts to learn more about Dark Matter include searching for it at high energy particle colliders. The lack of information about the nature of Dark Matter makes this a complicated task, and many searches are performed in dierent channels, and considering dierent theoretical models. In this thesis, I explore two such analyses, performed in the ATLAS collaboration using data from the ATLAS detector at the Large Hadron Collider at CERN: the tW+MET (missing transverse energy) nal state and the tt+MET nal state. I have made a generation-level study of the overlap between the signal regions used, and come to the conclusion that there is some. I have also compared the models used in these analyses, the 2HDM+a and the simplied spin-0 pseudoscalar model. Given the simplications made in my study, however, more sophisticated approaches should be used before anything conclusive can be said.
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TUDURI, JOHANN. "Processus de formation et relations spatio-temporelles des minéralisations à or et argent en contexte volcanique Précambrien (Jbel Saghro, Anti-Atlas, Maroc). Implications sur les relations déformation-magmatisme-volcanisme-hydrothermalisme." Phd thesis, Université d'Orléans, 2005. http://tel.archives-ouvertes.fr/tel-00008937.
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Dans le Jbel Saghro (Anti-Atlas oriental, Maroc), deux évènements tectono-magmatiques ont été reconnus et mis en relation avec les processus hydrothermaux. Le socle sédimentaire Néoprotérozoïque moyen a été affecté par une déformation ductile faible, sous le contrôle d'une direction de raccourcissement orientée ca. NW-SE, responsable de la formation de grands plis et d'une schistosité plan axial, d'accidents décrochants dextres N070-090°E, de chevauchements localisés et de la mise en place de plutons granodioritiques syntectoniques. Le deuxième évènement se caractérise par l'instauration d'un important volcano-plutonisme acide Néoprotérozoïque supérieur associé au dépôt des principales minéralisations à Au-Ag du secteur. A Kelâa M'Gouna, cet épisode a été rattaché à la formation d'une caldera ignimbritique. Bien que chacun des dépôts hydrothermaux présente des spécificités particulières, toutes les structures minéralisées se sont formées en réponse à une direction de raccourcissement orientée ca. WNW-ESE, la même qui contrôle la mise en place du volcanisme ignimbritique.
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Pelleter, Ewan. "Géologie, géochimie et géochronologie du gisement aurifère de Tamlalt-Menhouhou (Haut-Atlas oriental)." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2007. http://tel.archives-ouvertes.fr/tel-00192430.
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En raison de sa localisation particulière en bordure du craton Ouest Africain, le Maroc révèle une histoire géodynamique complexe qui commence au Paléoprotérozoïque et qui se poursuit jusqu'aux derniers évènements alpins. Ce polyphasage se traduit notamment par la formation de minéralisations télescopées dans le temps et dans l'espace. Le gisement aurifère de Tamlalt-Menhouhou se situe sur la bordure sud de la boutonnière paléozoïque de Tamlalt (Haut-Atlas oriental), jouxtant la limite entre la chaîne intra-cratonique atlasique du Haut- Atlas et la chaîne panafricaine de l'Anti-Atlas. Les minéralisations sont encaissées dans des formations volcano-sédimentaires de l'Ediacarien (âge U/Pb : 569 ± 8 Ma) probablement mise en place dans un contexte d'arrière-arc. Les roches felsiques néoprotérozoïques ont révélé le caractère fertile de la croûte néoprotérozoïque supérieure avec la présence d'une minéralisation barytique et d'une minéralisation ferrifère de type "Banded Iron Formations". Le secteur aurifère de Tamlalt-Menhouhou est recoupé par de nombreux décrochevauchements compatibles avec une tectonique cisaillante dextre. Deux minéralisations aurifères ont pu être identifiées : (i) une minéralisation aurifère primaire de type "Iron Oxide Copper Gold deposit" (IOCG) associée à un altération sodique (± calcique) caractérisée par un enrichissement en Au, Cu, Fe, Co, Ni, Mo, As, Sb, ± Bi, et (ii) une minéralisation aurifère secondaire de type "Shear zone related gold deposit" associée aux altérations argilleuses et phylliteuses localisées le long des décro-chevauchements. L'étude détaillée à la microsonde ionique effectuée sur les zircons hydrothermaux génétiquement associés au phénomène d'albitisation permet d'obtenir un âge Ordovicien supérieur de 449 ± 8 Ma pour la minéralisation aurifère primaire, ce qui constitue une première au Maroc. Cet âge est confirmé par la datation 40Ar/39Ar sur deux mono-grains de muscovites soulignant le potentiel des zircons à enregistrer des évènements hydrothermaux, et leur intérêt en métallogénie. La minéralisation aurifère secondaire est datée à 293 ± 7 Ma (Stéphano-autunien) par géochronologie 40Ar/39Ar sur des phengites associées à l'altération argilleuse et phylliteuse et aux veines de quartz aurifères. Cet âge est en accord avec celui proposé pour la phase cisaillante dextre tardi-varisque, et souligne l'importance de cette orogenèse pour la remobilisation de pré-concentrations métallifères.