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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

A Survey Strategy for Light Echoes from Historical Supernovae in the Milky Way

Oaster, Lindsay 08 1900 (has links)
Hundreds of years after exploding, the original light from a supernova can still be observed in the form of light echoes. This light scatters off interstellar dust and is re-directed back toward Earth; due to the extra travel time, we observe the echo after the initial outburst. At some time t after observing the outburst, the surface of equal travel paths defines an ellipsoid with Earth and the supernova at the foci. If dust intersects this ellipsoid it is possible to scatter the light and produce an echo. In this thesis, I develop a relative probability model for the detection of supernova light echoes based on the physical characteristics of interstellar dust and absorption near the Galactic plane. This model includes a dust scattering function, distribution (scale height) of dust in the Galaxy, the dilution of echo flux with distance, and absorption along the supernova-dust-Earth travel paths. I have tested the model's predictions against observations and compared it with a prior survey strategy based on IRIS (re-processed IRAS) maps. Currently the IRIS-based strategy is more effective at selecting good paintings but its detection rate is only around 5%, highlighting the elusiveness of echo appearances. This work considers six historical supernovae in the Milky Way, all of which exploded in the pre-telescopic era (with the possible exception of Cas A) and were recorded as "guest stars" in astronomy records from Asia, Europe, and the Middle East. Their light echoes could give us information on these historically significant events and an opportunity to simultaneously study a supernova in outburst and several hundred years later. Early investigations suggest that the distribution of CO in the Galaxy may anti-correlate with the best paintings for light echoes; if a CO-echo link can be established, this would be useful in future light echo surveys. / Thesis / Master of Science (MSc)
62

Emotion and knowing : being attuned to the world

Hardy, Carter M. 01 January 2010 (has links)
The question "what is an emotion?" has been asked often throughout the history of philosophy, but few have come to an agreement about a definition or even how to study the emotions. In this thesis, I attempt to describe the nature and importance of emotions in terms of the way emotions affect one's experience of the world. I begin by analyzing five different theories of emotion: those of the Stoics, Aristotle, Spinoza, William James, and Sartre, which depict a wide range of theories that view emotion in both a positive and a negative sense. From them, I come to general definition of emotion that utilizes the strengths of the historical theories and goes beyond them. Then, I tum to addressing the way emotions affect the way the world is experienced. Using Heidegger, I claim that emotions attune people to the world, so that they notice different aspects of the world in one emotional state than they would in another emotional state. From here, the relationship between emotions and rationality is addressed. I claim that emotions are not irrational or arational, but are important to reason because they function as salience generators. As salience generators, emotions focus the reasoning process, narrowing down the options so that one can reason more quickly and with personal purpose. Finally, it is explained that emotion, though helpful to reason, is not a perfect way of knowing. Emotions are shown to be subjective, but not in a negative sense. They can be misleading at times, but they can still be trusted through three methods: (1) harmony between ways of knowing, (2) intersubjective corroboration, and (3) personal reflection.
63

From heavy atoms to the outer galaxy : characterizing the chemistry of the Milky Way halo

Roederer, Ian Ulysses 26 October 2010 (has links)
This dissertation describes our efforts to use the assembly of matter on nuclear scales as a probe of the assembly of matter on Galactic scales. To investigate the former, we characterize the detailed abundance patterns of the heaviest elements found in ancient, metal-poor stars in the Galaxy. In particular, we place new constraints on and identify several new correlations among the nuclei produced by the rapid nucleosynthetic process, which we use to refine current models of the physical conditions of this process. To investigate the latter, we apply our knowledge of stellar nucleosynthesis to examine correlations between the space motions of stars and their compositions, which retain a record of the composition of the interstellar medium where they formed many billions of years ago. Using new high quality stellar spectra collected from McDonald Observatory and Las Campanas Observatory, we confirm the relative chemical homogeneity of a well-known stellar stream and identify several chemical differences between the two major components of the stellar halo of the Galaxy. Each of these results has significant implications for our understanding of how the Galactic halo formed, grew, and evolved. More profoundly, these results indicate that we have not yet fully characterized the cosmic origins of the heaviest elements in the universe and that we will likely need to examine large samples of metal-poor stars at great distances from the Sun to potentially do so. / text
64

Wayshowing i Visualiceringscenter C : Jämförelse av observationer under skyltskapande i virtuell miljo / Wayshowing : Signage design process in virtual reality

Syversen, Eva January 2012 (has links)
Denna kandidatuppsats behandlar wayshowing i en 3D-modell av Visualiseringscenter C, Norrköping. Syftet är att undersöka olika sätt att göra skyltar i virtuell miljö och vilket sätt som är mest lättarbetat för användaren som ska skapa dessa skyltar. Uppsatsen utgår från teori om wayshowing och om hur en bra skylt ska se ut för att uppfylla sitt syfte. Med hjälp av denna teori har skyltar skapats i en 3D-miljö. Det insamlade materialet som resultaten är baserade på kommer från två strukturerade observationer och en intervju. Deltagaren och observatören i observationerna var författaren själv och under intervjun hördes en student med liknande erfarenheter kring grafisk design och 3D som författaren. I observationerna testades två sätt att skapa skyltar; ett sätt där texturen gjordes innan skyltarna tillverkades i 3D-miljön och ett sätt där texturen gjordes efter det att skyltarna hade tillverkats i 3D- miljön. Resultaten från observationerna visar att det senare sättet är smidigast att använda eftersom det är lättare att anpassa texturen till skylten efter det att skylten har blivit modellerad i 3D. Observationerna undersökte även vilka digitala processer som användes och vilken tid de processerna tog. Under observationerna framkom att rendering var den digitala process om användes flest gånger. Den process som ansågs ta mest tid var så kallade tutorials, att ta reda på och införskaffa kunskap om hur ett moment kan utföras. Observationerna visade även att det är tidssparande att återanvända kameror, material och 3D-modeller. / This bachelor thesis is about wayshowing in a 3D model of Visualiseringscenter C, Norrköping. The aim is to examine different ways to make signs in a virtual environment and which of these ways is the easiest to apply for the user. The essay is based on theory regarding wayshowing and how a good sign should look in order to fulfill its purpose. With the use of this theory, signs have been created in a 3D environment. The collected data which the results are based on comes from two structured observations and one interview. The participant and the observer of the observations was the author herself and the interview was done with a student who has similar experiences in graphic design and 3D as the author. The observations evaluated two different ways to create signs. One way in which the texture was made before the signs were made in the 3D environment and one way in which the texture was made after the signs had been manufactured in the 3D environment. The results of the observations show that the latter approach is more convenient to use because it is easier to adjust the texture after the sign has been created. The observations also considered the digital processes used and the time spent on these processes. The observations revealed that rendering was the most used digital process. The digital process which was most time consuming was the use of tutorials, i.e. to acquire knowledge of how an previously unknown digital process could be performed. The observations also revealed that re-use of cameras, materials, and 3D models was time saving.
65

Dialogen som skapar förändring

Nilsson, Charlotte, Daun, Anna January 2012 (has links)
The purpose of this study is to gain increased understanding of managers´ attitudes and knowledge about its role in the internal organizational communication. We want to understand how managers define dialogue and further understand the role that dialogue plays for managers. We want to see whether the different managers highlight some common foundations or differences in the dialogue. With the help of the following two questions we wish to understand managers´ relationship to the dialogue within the internal organizational communication:   -What meaning does the dialogue have for managers in the private sector? -What role does the dialogue play in the internal organizational communication according to these managers?   We use qualitative interviews as the data collection method of our material. Using material from the interviews and mainly in accordance with William Isaacs’ theory of dialogue, we can answer our questions.   The result shows that managers' views on the dialogue in many cases are similar to Isaacs’ vision but differs in part. The managers believe that employees are there to contribute to the company. The dialogue is used so that the employees in the business understand and reach the financial goals and visions. Isaacs says that all people are part of a whole and the dialogue is needed to achieve agreement and change. Isaacs also takes up the four pillars of an effective dialogue: listen, respect, await and talk undisguised.  Several of the managers agree with Isaacs that there has to exist a certain platform for an effective dialogue. We discovered three categories of the dialogues’ meaning and role for the managers and that the categories depend on the type of organization. All managers believe that the dialogue’s role is an important part of a well functioning organization. / Syftet med denna undersökning är att få ökad förståelse kring chefers syn och kunskap om dialogens betydelse inom den interna organisationskommunikationen.  Vi vill förstå hur chefer definierar dialog och vidare försöka förstå vilken roll dialogen spelar för chefer. Vi vill se om de olika cheferna belyser några gemensamma grundpelare eller skillnader vad gäller dialog. Med hjälp av följande två frågeställningar önskar vi förstå chefers relation till dialogen inom intern organisationskommunikation:    - Vad betyder dialog för chefer inom den privata sektorn? - Vilken roll spelar dialogen i den interna organisationskommunikationen enligt dessa chefer?   Vi använder oss av kvalitativa intervjuer som insamlingsmetod av vårt material. Med hjälp av materialet från intervjuerna och huvudsakligen William Isaacs teori om dialogen kan vi besvara våra frågeställningar.    Resultatet visar att chefers syn på dialogen i många fall är lik Isaacs syn men skiljer sig delvis.  Cheferna anser att människan är till för verksamheten och dialogen är till för att människorna i verksamheten ska kunna förstå och nå de ekonomiska mål och visioner vilka är uppsatta. Isaacs menar att alla är delar av en helhet och dialogen krävs för att kunna uppnå samförstånd och förändring. Isaacs tar även upp fyra grundpelare för en fungerande dialog; lyssna, respektera, avvakta och tala oförställt. Flera av cheferna håller med Isaacs om grunderna för en dialog. Vi kommer fram till tre kategorier för dialogens betydelse och roll för cheferna och att kategorierna är beroende av verksamhetstypen.  Samtliga chefer anser att dialogens roll är en viktig del för en fungerande verksamhet.
66

Hygiene and Sanitation Promotion towards Cholera Prevention on District Level in Mozambique : A Communication Analysis

Booij, Dorrit, Al-Ayoubi, Daniel January 2015 (has links)
Cholera remains a threat to public health in many developing countries, including Mozambique. Although the disease is easily preventable by practices of hygiene and sanitation, cases are reported in the country every year, as for example in the Lago district in 2015. This qualitative research project set out to explore in what ways the promotion of hygiene and sanitation practices on district level in Mozambique is carried out. Therefore, actors, messages and channels involved in these communication processes were explored via a field study in Lago and a review of relevant literature. Subsequently, the results of the field study and literature review were analysed by applying the concepts of one-way and two-way communication which are part of public relations theory. This analytical framework allowed the researchers to fill a gap identified in the existing literature about hygiene and sanitation promotion, which did not seem to include communication theories linked to public relation practices when it came to hygiene and sanitation promotion in developing countries as a method to prevent cholera. It has been found that the one-way communication approach towards the public was successful in handling the recent cholera outbreak of 2015, however, the approach is not substantial and should be improved into a two-way communication approach, which would allow the local population to express their needs in hygiene and sanitation, as well as their capabilities to implement change in these matters. Simultaneously, a lack of resources within the district authorities involved in hygiene and sanitation promotion seems to encourage one-way communication towards the public from their side, as two-way communication would demand further resources for research into the above mentioned needs and capabilities of communities.
67

Performance Analysis of MIMO Relay Networks with Beamforming

January 2012 (has links)
abstract: This dissertation considers two different kinds of two-hop multiple-input multiple-output (MIMO) relay networks with beamforming (BF). First, "one-way" amplify-and-forward (AF) and decode-and-forward (DF) MIMO BF relay networks are considered, in which the relay amplifies or decodes the received signal from the source and forwards it to the destination, respectively, where all nodes beamform with multiple antennas to obtain gains in performance with reduced power consumption. A direct link from source to destination is included in performance analysis. Novel systematic upper-bounds and lower-bounds to average bit or symbol error rates (BERs or SERs) are proposed. Second, "two-way" AF MIMO BF relay networks are investigated, in which two sources exchange their data through a relay, to improve the spectral efficiency compared with one-way relay networks. Novel unified performance analysis is carried out for five different relaying schemes using two, three, and four time slots in sum-BER, the sum of two BERs at both sources, in two-way relay networks with and without direct links. For both kinds of relay networks, when any node is beamforming simultaneously to two nodes (i.e. from source to relay and destination in one-way relay networks, and from relay to both sources in two-way relay networks), the selection of the BF coefficients at a beamforming node becomes a challenging problem since it has to balance the needs of both receiving nodes. Although this "BF optimization" is performed for BER, SER, and sum-BER in this dissertation, the solution for optimal BF coefficients not only is difficult to implement, it also does not lend itself to performance analysis because the optimal BF coefficients cannot be expressed in closed-form. Therefore, the performance of optimal schemes through bounds, as well as suboptimal ones such as strong-path BF, which beamforms to the stronger path of two links based on their received signal-to-noise ratios (SNRs), is provided for BERs or SERs, for the first time. Since different channel state information (CSI) assumptions at the source, relay, and destination provide different error performance, various CSI assumptions are also considered. / Dissertation/Thesis / Ph.D. Electrical Engineering 2012
68

Analise de imagens nivel de cinza utilizando metodos quimiometricos / Analysis of gray-scale images by using chemometric methods

Ribeiro, Fabiana Alves de Lima 15 August 2007 (has links)
Orientador: Marcia Miguel Castro Ferreira / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-10T22:13:52Z (GMT). No. of bitstreams: 1 Ribeiro_FabianaAlvesdeLima_D.pdf: 3726334 bytes, checksum: 73ef285be301366b14be78adce7c034e (MD5) Previous issue date: 2007 / Resumo: Imagens são utilizadas na investigação científica há muito tempo, inicialmente apenas como ferramentas para a representação da prática científica, e após o surgimento das técnicas de microscopia, como instrumento para registro e análise instrumental. Com o aperfeiçoamento das técnicas de obtenção de imagens, cresceu a demanda por técnicas quantitativas e sistematizadas para extrair-lhes informações, e capazes de estabelecer critérios estatisticamente confiáveis para, por exemplo, detectar similaridades, padrões, classificar, e até mesmo gerar modelos preditivos. Neste trabalho, métodos quimiométricos foram utilizados como ferramenta quantitativa para a análise de imagens nível de cinza, utilizando como exemplos imagens de microscopia de força atômica de fibras capilares de diferentes classes. Fibras capilares são frequentemente utilizadas em clínicas, indústrias ambientais e análises forenses, para o diagnóstico de doenças, avaliação da exposição aos agentes tóxicos e poluentes e detecção de abuso de drogas. Para este trabalho foram utilizados dois conjuntos de dados: um deles formado por amostras de fibras caucasianas submetidas ao tratamento de descoloração e outro com fibras de diferentes etnias. O objetivo foi utilizar métodos quimiométricos para construir modelos classificatórios capazes de identificar corretamente novas imagens. Diversas estratégias foram testadas e os melhores resultados foram obtidos utilizando os métodos SIMCA (Soft Independent Modeling of Class Analogy), PARAFAC (Parallel Factor Analysis), MPCA (Multi-way Principal Component Analysis) e NPLS (Multi-way Partial Least Squares). Os modelos quantitativos apresentaram erros de calibração abaixo de 10% e erros de predição em torno de 10%. Com exceção de uma das aplicações, que é específica para fibras capilares, os outros métodos de análise de imagens propostos podem ser utilizados na análise quantitativa de qualquer tipo de imagem nível de cinza / Abstract: Images have been used in scientific investigation for a long time, initially as a tool for representation of the scientific practice and, after the microscopy development, as an instrument for registration and instrumental analysis. With the improvement of microscopic techniques, there was an increase on the demand for quantitative and systematic tools to extract relevant information from images and for techniques capable to establish reliable statistical approaches, for example, to detect similarities, patterns and for classification. In this work, multivariate methods were used as quantitative tools for the analysis of nível de cinza images of different classes of hair fibers. These images were obtained by atomic force microscopy. Hair fibers are frequently used in medical clinics, environmental industries and forensic analyses, for the diagnosis of diseases, evaluation of the exposure to toxic agents and pollutants, and detection of abuse of drugs. In this work two data sets were used: the first one contained caucasian hair fibers submitted to peroxide treatment and the second one contained fibers from different ethnic origin (oriental, african and caucasian). The goal was to use chemometric methods to build classification models capable to identify new images correctly. Several strategies were tested and the best results were obtained by using SIMCA (Soft Independent Modeling of Class Analogy), PARAFAC (Parallel Factor Analysis), MPCA (Multi-way Principal Component Analysis) and NPLS (Multi-way Partial Least Squares). The models presented calibration errors below 10% and prediction errors around 10 %. With exception of the descriptor analysis, which is specific for hair fibers images, the proposed methods can be useful for quantitative analysis of any kind of nível de cinza images / Doutorado / Físico-Química / Doutor em Ciências
69

Intergenericidade em anÃncios publicitÃrios: uma abordagem semiolinguÃstica / INTER-GENDER IN ADVERTISING:a semilinguistic approach

MarÃlia de Carvalho Cerveira 26 June 2009 (has links)
nÃo hà / Este trabalho apresenta um estudo sobre intergenericidade, como recurso de persuasÃo em anÃncios publicitÃrios, analisado a partir do modelo teÃrico da SemiolinguÃstica, proposto por Charaudeau (2008), cujo objetivo à verificar de que modo a intergenericidade participa da construÃÃo enunciativa, considerando a posiÃÃo adotada pelo sujeito (alocutivo, elocutivo e delocutivo) na encenaÃÃo e analisar de que forma a posiÃÃo adotada por este sujeito no anÃncio contribui para a construÃÃo da persuasÃo. / This work presents a study about all genres, like persuasion resource in advertising, analyzed from Semilinguistics theoretical model, it was proposed by Charaudeau (2008), whose goal is to verify how all genres takes part in the enunciated construction, considering the position which was adopted by the subject (allocution, elocution and no locution) in the staging and to analyze which form the position adopted by this subject in the advertisings contributes for the construction of the persuasion. We have analyzed 20 advertisings that advertise or sell one benefit or service. Like analysis criterion of all genres, we consider that there was deviation or maintenance of the sense, of the content, of the thematic and of the style of the involved genres. Yet in the analysis of the argumentative way, we chose as analysis categories, the argumentative relation (assertive of departure, of arrival and of the passageway) and the argumentative device (proposal, proposition and persuasion) the analyses revealed that the investigated advertisings did not suffer alteration of their recurring elements (body of the text and signature/type). For all genres, while stylistic resource, reproduces profound or superficially the contract, the thematic and the textual organization from other genre, allowing that the advertising assumes all the characteristics of this other genre, inclusive of the positioning of the subjects inside the enunciated staging without the appellative character be abandoned. In the analysis of the enunciated way , we verify that all genres served to build a staging in which the subject commentator practices influence relation and authority in relation to the interlocutor attesting a positioning of the own allocution of the advertisings. we also prove that the argumentation starts being organized from all genres and, thus, the genre used in the advertising serves like cloth of fund for the development of the staging. In short, the analyses proved that all served as the base element of the staging composition as advertised as argumentative and, therefore, it takes part and it interferes in the construction of the way of telling of the advertising genre.
70

The co-construction of helping services in Ennerdale

Roper, Jonathan 12 September 2005 (has links)
The co-construction of helping services in the community of Ennerdale is a study that explores men’s reluctance to make use of helping and psychological services. Academic and informal literature informs us that men are often unwilling to seek medical or psychological assistance and that the male stereotypes view these services as utilised only by the weak and powerless. A great part of men’s unwillingness is furthermore related to historical male roles and the perception that the helping, and specifically the psychological services, are for the weak and insane. This research study was conducted in the Community of Ennerdale, a community south of Johannesburg. A focus group was conducted with adult male volunteers from the community and individual interviews were conducted with two psychologists, one medical doctor, and one church minister. The study was conducted from a social constructionist epistemology that falls within the qualitative research framework. The social constructionist epistemology views our (individuals) understanding and views of our world as a uniquely social process that is influenced by our gender, culture, language, and history. A discourse analysis was utilised to analyse the information obtained from both the focus group and individual interviews. The results from this research study indicate that a great part of men’s reluctance is related to the dominant male discourses and male scripts that construct men as superior and proud individuals who are not supposed to display weakness or inability. The helping and psychological services are constructed as services that assist the weak, insane and powerless, constructing an identity of weakness and insanity which men wait to avoid. The most common indicator for men’s reluctance is the historical constructs of the helping services and the historical constructs and discourses related to masculinity and appropriate male behaviour. / Dissertation (MA (Counselling Psychology))--University of Pretoria, 2006. / Psychology / unrestricted

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