The diploma thesis deals with research of the jet issuing from the defrost duct of Skoda Octavia car. Components of velocity and turbulence intensity were measured using hot wire anemometry. Obtained data were presented in graphs and contour maps. Results were confronted with previous research.

I samband med utbrottet av covid-19 introducerades kontaktspårningsapplikationer (contact tracing application, CTA), eftersom de har bevisats kunna vara ett effektivt verktyg för kontaktspårning och därmed minska smittspridning. CTA kan med hjälp av Bluetooth signaler bestämma en individs positionering och vilka personer de varit i kontakt med. Detta innebär att personlig data om dess användare samlas in, hanteras och lagras. CTA är beroende av en hög acceptans och användningsnivå för att fungera på ett effektivt sätt. I tidigare forskningsstudier uppmärksammas därmed att etiken kopplad till dessa applikationerna behöver belysas. Studien syftar därmed till att belysa vilka etiska problem som finns kopplade till användningen av CTA. Studien är utformad som en litteraturstudie med en kvalitativ innehållsanalys. Resultatet består av en sammanställning av de etiska problemen kopplade till CTA utifrån kategorierna i ramverket PAPA. Sammanställningen visar på att det finns många etiska problem kopplade till CTA som behöver bemötas och det visar även på att det är till stor del samma etiska problem som uppstår och är relevanta inom IS idag, som det har varit inom området i årtionden sedan PAPA skapades. / During the outbreak of covid-19, contact tracing applications (CTA) were introduced as they have been proven to be an effective tool for contact tracing and thereby reduce the spread of infection. With Bluetooth signals, CTA can determine an individual’s positioning and which people they have been in contact with. This means that personal data about its users is collected, managed, and stored. CTA depends on a high level of acceptance and usage to function effectively. In previous research studies, attention is thus drawn to the fact that ethics linked to these applications need to be enlightened. Therefore, this study aims to shed light on the ethical problems associated with CTA. The study is designed as a literature review with a qualitative content analysis. The result consists of a compilation of the ethical problems linked to CTA based on the categories in the PAPA framework. The compilation shows that there are many ethical problems linked to CTA that need to be addressed and it also shows that it is largely the same ethical problems that arise and are relevant in IS today, as it has been in the field for decades since PAPA was created.

Computed tomography angiography (CTA) of the brain poses challenges on the imaging system; the contrast between blood vessels and surrounding soft tissue is very low, and to render small intricate vessel structures high spatial resolution is needed. Higher precision angiography would facilitate more accurate diagnosis of pathological conditions. The aim of this work was to analyze the factors which contribute to the image quality in cerebrovascular imaging contexts and make a comparison between state-of-the-art energy-integrating and photon counting CT systems. A geometrical model was devised to mimic the conditions of cerebral angiography. Different parameters and detectors were used to reconstruct images of a spherical head phantom. Compton noise was added to several image acquisitions after a Monte Carlo study was used to estimate the scatter to primary ratio (SPR) with a spherical phantom. The images were evaluated qualitatively and quantitatively. A real phantom was scanned with an experimental photon counting detector and compared with the simulated approach. The work resulted in qualitative reconstructed images, a decrease in SPR when introducing air gaps and improved resolution but worsened contrast as a result of smaller detector sizes. The SPR was shown to be higher in cone-beam geometry than fan-beam geometry. Electronic noise present with energy integrating detectors was shown to degrade image quality significantly in low dose imaging, reducing contrast when imaging vascular-like structures. Photon counting detectors without electronic noise could provide greater image quality and better diagnostic information.

The substantial advances of coronary CTA have resulted in a boost of use of this new technique in the last several years, which brings a big challenge to radiologists by the increasing number of exams and the large amount of data for each patient. The main goal of this study was to develop a computer tool to facilitate coronary CTA analysis by combining knowledge of medicine and image processing.Firstly, a competing fuzzy connectedness tree algorithm was developed to segment the coronary arteries and extract centerlines for each branch. The new algorithm, which is an extension of the “virtual contrast injection” method, preserves the low density soft tissue around the coronary, which reduces the possibility of introducing false positive stenoses during segmentation.Secondly, this algorithm was implemented in open source software in which multiple visualization techniques were integrated into an intuitive user interface to facilitate user interaction and provide good over¬views of the processing results. Considerable efforts were put on optimizing the computa¬tional speed of the algorithm to meet the clinical requirements.Thirdly, an automatic seeding method, that can automatically remove rib cage and recognize the aortic root, was introduced into the interactive segmentation workflow to further minimize the requirement of user interactivity during post-processing. The automatic procedure is carried out right after the images are received, which saves users time after they open the data. Vessel enhance¬ment and quantitative 2D vessel contour analysis are also included in this new version of the software. In our preliminary experience, visually accurate segmentation results of major branches have been achieved in 74 cases (42 cases reported in paper II and 32 cases in paper III) using our software with limited user interaction. On 128 branches of 32 patients, the average overlap between the centerline created in our software and the manually created reference standard was 96.0%. The average distance between them was 0.38 mm, lower than the mean voxel size. The automatic procedure ran for 3-5 min as a single-thread application in the background. Interactive processing took 3 min in average with the latest version of software. In conclusion, the presented software provides fast and automatic coron¬ary artery segmentation and visualization. The accuracy of the centerline tracking was found to be acceptable when compared to manually created centerlines.

Die vorliegende Arbeit beschäftigt sich mit zwei Aspekten der Gammastrahlungsastronomie. Einerseits studiert sie die Anforderungen an das zukünftige CTA-Observatorium für Gammastrahlung und präsentiert insbesondere Abschätzungen der Datenmengen, die während des Betriebs des Observatoriums anfallen werden. Für das größere CTA-Teleskopfeld auf der Südhalbkugel werden demnach eine Triggerate von 13 kHz und Datenraten von bis zu 2500 MB/s erwartet. Unter der Annahme, dass 15% der Zeit für Beobachtungen genutzt werden können, ergibt sich in 15 Jahren ein Datenvolumen von bis zu 165 PB. Die Implementation eines entsprechenden Systems zur Datenerfassung und -speicherung stellt eine Herausforderung dar, die jedoch mit existierenden Technik bewältigt werden kann. Andererseits befasst sie sich mit dem Supernovaüberrest RX J0852.0-4622 (auch bekannt als Vela Junior), präsentiert die Ergebnisse einer Analyse von Daten, die mit dem H.E.S.S.-Experiment genommen wurden, und geht der Frage nach, ob RX J0852.0-4622 ein kosmischer Teilchenbeschleuniger ist. Dabei erlauben die präzisen Messungen eine im Vergleich zu früheren Veröffentlichungen verbesserte Bestimmung der Eigenschaften der emittierenden Teilchenpopulation. Es ergibt sich, dass das Energiespektrum von RX J0852.0-4622 ein Potenzgesetz ist, das zu hohen Energien hin mit einer Abschneideenergie von 7.2 TeV exponentiell unterdrückt wird. Abschließend wird anhand von Simulation gezeigt, dass CTA die Abschneideenergie von RX J0852.0-4622 signifikant besser bestimmen können wird. Diese genauere Vermessung des Energiespektrums sollte dazu beitragen, den hadronischen oder leptonischen Charakter der Emission aufzuklären. / This work focuses on two different aspects of gamma-ray astronomy. On the one hand, it studies the instrumental challenge posed by the future CTA Observatory by estimating the amount of data to be collected. Based on an analysis of simulated data, the more demanding southern array is expected to have an array trigger rate of 13 kHz, a data rate of up to 2500 MB/s and a data volume after 15 yr of operation and assuming a duty cycle of 15% of up to 165 PB. The design of the data acquisition and storage systems will be a challenge but should be manageable with existing technologies. On the other hand, it studies supernova remnants, by presenting analysis results of the gamma-ray data of the RX J0852.0-4622 supernova remnant (commonly known as Vela Junior) measured with the operating H.E.S.S. experiment and interpreting them in order to check the plausibility of RX J0852.0-4622 being a cosmic ray accelerator. The more precise measurements permit a better determination of the parent particle population properties with respect to previous publications. More precisely, a clear curvature of the spectrum of RX J0852.0-4622 is measured with an exponential energy cut-off at 7.2 TeV. Finally, the analysis of simulated data shows that CTA should be able to significantly improve the determination of the spectral energy cut-off of RX J0852.0-4622, which should help in identifying the nature of the gamma-ray emission.

Die vorliegende Arbeit beschreibt einen semi-analytischen Ansatz zur Modellierung der Dichteverteilung von DM im Galaktischen Halo. Aus den verschiedenen Substrukturmodellen wird die γ-Strahlungsintensität, welche die Erde erreicht, berechnet. Eine Spannbreite plausibler γ-Strahlungsintensitäten aufgrund der Paarvernichtung Galaktischer DM wird vorgeschlagen, welche die Vorhersagen verschiedener früherer Studien umfasst, und es werden die durchschnittlichen Massen, Abstände und ausgedehnten Strahlungsprofile der γ-strahlungsintensivsten DM-Verdichtungen berechnet. Schließlich werden die DM-Modelle für eine umfassende Berechnung der Nachweismöglichkeit Galaktischer Substrukturen mit CTA verwendet. Die instrumentelle Sensitivität zum Nachweis der γ-strahlungsintensivsten DM-Substruktur wird für eine mit CTA geplanten großflächigen Himmelsdurchmusterung außerhalb der Galaktischen Ebene berechnet. Die Berechnung wird mit CTA Analyse- Software und einer Methode durchgeführt, welche auf einer Likelihood beruht. Eine alternative, ebenfalls Likelihood-basierte Analysemethode wird entwickelt, mit welcher DM-Substrukturen als äumliche Anisotropien im Multipolspektrum des Datensatzes einer Himmelsdurchmusterung nachgewiesen werden können. Die Analysen ergeben, dass eine Himmelsdurchmusterung mit CTA und eine anschließende Suche nach γ-Strahlung von DM-Substrukturen Wirkungsquerschnitte für eine Paarvernichtung in der Größenordnung von (σv) > 1 × 10−24 cm3 s−1 für eine DM-Teilchenmasse von mχ ∼ 500 GeV auf einem Vertrauensniveau von 95% ausschließen kann. Diese Sensitivität ist vergleichbar mit Langzeitbeobachtungen einzelner Zwerggalaxien mit CTA. Eine modellunabhängige Analyse ergibt, dass eine Himmelsdurchmusterung mit CTA Anisotropien im diffusen γ-Strahlungshintergrund oberhalb von 100 GeV für relative Schwankungen von CPF > 10−2 nachweisen kann. / In the current understanding of structure formation in the Universe, the Milky Way is embedded in a clumpy halo of dark matter (DM). Regions of high DM density are expected to emit enhanced γ-radiation from the DM relic annihilation. This γ-radiation can possibly be detected by γ-ray observatories on Earth, like the forthcoming Cherenkov Telescope Array (CTA). This dissertation presents a semi-analytical density modeling of the subclustered Milky Way DM halo, and the γ-ray intensity at Earth from DM annihilation in Galactic subclumps is calculated for various substructure models. It is shown that the modeling approach is able to reproduce the γ-ray intensities obtained from extensive dynamical DM simulations, and that it is consistent with the DM properties derived from optical observations of dwarf spheroidal galaxies. A systematic confidence margin of plausible γ-ray intensities from Galactic DM annihilation is estimated, encompassing a variety of previous findings. The average distances, masses, and extended emission profiles of the γ-ray-brightest DM clumps are calculated. The DM substructure models are then used to draw reliable predictions for detecting Galactic DM density clumps with CTA, using the most recent benchmark calculations for the performance of the instrument. A Likelihood-based calculation with CTA analysis software is applied to find the instrumental sensitivity to detect the γ-ray-brightest DM clump in the projected CTA extragalactic survey. An alternative Likelihood-based analysis method is developed, to detect DM substructures as anisotropies in the angular power spectrum of the extragalactic survey data. The analyses predict that the CTA extragalactic survey will be able to probe annihilation cross sections of ⟨σv⟩ > 1 × 10−24 cm3 s−1 at the 95% confidence level for a DM particle mass of mχ ∼ 500 GeV from DM annihilation in substructures. This sensitivity is compatible with long-term observations of single dwarf spheroidal galaxies with CTA. Independent of a particular source model, it is found that the CTA extragalactic survey will be able to detect anisotropies in the diffuse γ-ray background above 100 GeV at a relative amplitude of CP_F > 10−2.

No description available.

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No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_PerfilEpidemiologicoUsuarios.pdf: 4728871 bytes, checksum: 4a327f46edd182df856ef8b921cba215 (MD5) Previous issue date: 2011 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / A pandemia pelo HIV e aids representam um fenômeno global, dinâmico e instável. Uma das principais conquistas alcançadas no controle da epidemia foi a criação e a expansão dos Centros de Testagem e Aconselhamento (CTA) em várias regiões do país. Estes centros representam a porta de entrada do indivíduo infectado no sistema de saúde e constituem serviços especializados no diagnóstico, orientação sobre transmissão e prevenção do HIV. O objetivo geral da pesquisa foi descrever o perfil epidemiológico, assim como os comportamentos de risco dos usuários que foram atendidos no CTA-Belém, entre janeiro de 2008 e dezembro de 2010 com sorologia positiva para HIV. Para tal finalidade foi realizada uma busca ativa e sigilosa nos prontuários arquivados respeitando o anonimato dos usuários e todos os preceitos éticos que envolvem a manipulação das informações. Foram analisados os dados de 547 usuários soropositivos para HIV do CTA-Belém durante o período de estudo (prevalência de 6,09%). Os resultados da pesquisa esclareceram o perfil dos usuários soropositivos, que eram em maioria da população geral e não faziam parte de nenhum grupo mais vulnerável à infecção viral e procuraram o serviço por terem sido expostos à alguma situação de risco e encaminhados por outros serviços/profissionais de saúde. No que tange ao comportamento de risco, 98,5% relataram exposição sexual e os resultados alertam para o não uso de preservativos em relações sexuais fixas e eventuais, sendo os principais motivos para este comportamento a confiança no parceiro, a não disponibilidade de preservativo no momento da relação sexual e outros. Conclui-se que embora haja similaridades em relação à outros estudos desenvolvidos no país e com a atual tendência da epidemia de HIV/AIDS, existem peculiaridades em nossa região que merecem melhor direcionamento da intervenção preventiva por parte da saúde pública tais como disponibilização gratuita de preservativos e campanhas de orientação para o uso dos mesmos em relações estáveis, inclusive na população com maior escolaridade e situação profissional estável. / The pandemic of HIV and aids represent a global phenomenon, dynamic and unstable. One of the main achievements in controlling the epidemic was the creation and expansion of Counseling and Testing Centers (CTC) in several regions of the country. These centres represent the input port of the individual is infected in the health system and provide specialist services in diagnosis, guidance on HIV transmission and prevention. The overall objective of the survey was to describe the epidemiological profile, as well as the risk of users behaviors that were serviced in CTA-Belém, between January 2008 and December 2010 with positive serology for HIV. For this purpose was held an active pursuit and confidentially in medical records archived respecting the anonymity of users and all ethical precepts that involve the manipulation of information. Were analyzed the data of 547 users with HIV of CTA-Belém during the study period (prevalence 6,09%). The results of the survey clarified the profile of users with AIDS, who were in the majority of the general population and were not part of any group more vulnerable to viral infection and sought service have been exposed to some risk and forwarded by other services/health professionals. Regarding the risky behavior, 98.5% reported sexual exposure and results warn not to use condoms in sex with both fixed and with possible partners, being the main reasons for this behavior trust in partnerthe non-availability of condoms during sexual intercourse and others. It is concluded that although there are similarities in relation to other studies developed in the country and with the current trend of HIV/AIDS epidemic, there are peculiarities in our region who deserve better targeting of preventive intervention on the part of public health such as providing free condoms and guidance campaigns for use in stable relationships, including in the population with higher education and professional situation stable.

La Centrale de traitement d'Air par Dessiccation (CAD) offre un contrôle complet de la température et de l'humidité dans les locaux climatisés. Son élément clé est la roue dessicante qui permet la dessiccation de l'air et une régénération continue. A travers cette étude, nous nous intéressons au développement d'une méthodologie pour obtenir un modèle dynamique de la roue utilisable dans les algorithmes de contrôle avancés de la CAD. La roue dessicante peut être considérée comme un système de type multi-entrées/multi-sorties (MIMO). La seconde partie de ce mémoire concerne l'identification expérimentale des paramètres des modèles d'état de la roue dessicante pour deux types de modèles : boîte noire et boîte grise. Dans le cas de la boîte noire, tous les paramètres du modèle sont identifiés expérimentalement. Dans le cas de la boîte grise, certains paramètres sont dérivés de considérations physiques et les paramètres restants sont identifiés en utilisant les mesures expérimentales des entrées et des sorties. Les paramètres du modèle boîte grise ont une signification physique. En comparaison avec les modèles boîte noire, les modèles boîte grises sont moins précis sur le domaine sur lequel les paramètres ont été identifiés, mais beaucoup plus précis en dehors de ce domaine. Comme les paramètres ont une signification physique, leurs valeurs ne varient pas de manière significative avec le point de fonctionnement utilisé pour l'identification. Dans l'approche boîte grise, les valeurs des paramètres obtenues pour les modèles linéaires sont presque identiques pour tous les modèles locaux du coté dessiccation et pour tous les modèles locaux du coté régénération ; cela nous a permis de considérer qu'un modèle local est valable pour tout le domaine de variation des variables d'entrée. Le modèle final de la roue dessicante se compose de deux modèles globaux : un pour le côté de la dessiccation et l'autre pour le côté de la régénération. La troisième partie de ce travail consiste dans l'identification des coefficients de transfert de masse et de chaleur au sein de la roue dessicante en utilisant un modèle boîte grise. Le coefficient de transfert de masse, le coefficient de transfert convectif et le nombre de Nusselt ont été obtenus en écrivant les paramètres du modèle d'état en fonction d'une seule variable et en exprimant les paramètres en fonction des caractéristiques géométriques et des propriétés de matériaux de la roue. Ce travail contribue au développement d'un modèle d'état utilisable pour la synthèse des algorithmes de contrôle pour la roue dessicante.

This is a case study of the alternative labour union organization Central de Trabajadores de la Argentina (CTA) in Argentina and the most recent project under process striving for system change, named the Constituyente Social. The case under study is used to illustrate the perception of power in relation to aspirations for societal change among the left in Latin America. The overall struggle of the CTA and the Constituyente Social is to create a more just society based on a deepening of democracy, more participatory in character. Two understandings of power are presented, on the one hand is the taking power concept, inherited from the political struggles where the belief is that power needs to be taken from the elite in order to succeed with structural change in society. On the other hand is the creating power perception, best exemplified with the Zapatista movement in Mexico. There is no conquering of power in this view, but a creation and strengthening of power among the masses. The theoretical chapter presents a view that unites these two perceptions, arguing for the need to intersect the vertical (power taking) and the horizontal (power creating) struggles. The Constituyente Social is analyzed in relation to this intersection, providing concrete examples of where the two power perceptions are utilized, sometimes simultaneously. The overall conclusion is that the dichotomization usually done between the two understandings of power is incomplete and may even damage the struggle for societal change.