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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.
371

The Role of Dynamical Equilibrium Pressure in the Different Molecular Gas Ratios and Star Formation Properties of Cluster Galaxies and Field Galaxies / Dynamical Equilibrium Pressure in Cluster and Field Galaxies

Jindel, Taavishi January 2024 (has links)
The environment of a galaxy influences its gas and star formation properties via evolutionary mechanisms, such as ram pressure stripping and tidal stripping. In particular, the molecular to atomic gas ratio and dynamical equilibrium pressure are key parameters for understanding star formation in galaxies. I use 1.2 kpc resolution data for galaxies in the Virgo Cluster from the VERTICO survey and for field galaxies from the HERACLES survey to study the spatially resolved relationship between molecular to atomic gas ratios and star formation properties (eg. star formation rate, molecular gas depletion time) in galaxies as a function of dynamical equilibrium pressure. I find that cluster galaxies have higher molecular to atomic gas ratios at a given dynamical equilibrium pressure than field galaxies do. Within both samples there is strong galaxy to galaxy variation in the relationship driven by the gas content of each galaxy. In order to investigate the role of cluster environmental mechanisms on the properties of cluster galaxies I use atomic gas deficiency as a proxy for these environmental mechanisms. I find that atomic gas deficiency plays a significant role in the gas properties, star formation properties and dynamical equilibrium pressure of cluster galaxies. / Thesis / Master of Science (MSc)
372

Gamma-ray bursts in the local universe

Chapman, Robert January 2009 (has links)
With energy outputs >~10^51 erg in 0.1-1000 seconds, Gamma-ray Bursts (GRBs) are the most powerful events yet observed in the Universe. As such they are potential probes of the very early Universe, back to the era of re-ionisation and the first stars, but at the same time they have been observed to span a wide range in luminosity and redshift from the relatively local Universe (z~0.0085) out to z~6.29. GRBs divide into two classes based primarily on their duration as measured by T90 (the time taken to observe 90% of the total burst fluence). Long bursts (L-GRBs) have T90>~2 seconds, and shorts (S-GRBs) T90<~2 seconds. Though much has been learned regarding long duration GRBs since the first afterglow discovery in 1997 (including their likely association with massive core collapse supernovae), much remains unknown regarding short duration GRBs. In this work, after a brief historical introduction and review, we present analyses of the angular cross-correlation on the sky of short GRBs from the BATSE catalogue with galaxies in the local Universe sampled from the PSCz Redshift Survey and the Third Reference Catalogue of Bright Galaxies (RC3). In particular we show that 20%+/-8% (1 sigma) of all BATSE short duration bursts (localised to 10 degrees or better) show correlation with galaxy samples (morphological T-type<=4) within ~112 Mpc. Our statistics thus provide evidence that a substantial fraction of BATSE short GRBs show a tendency to be associated with large scale structure on the sky traced by a variety of galaxy types. Short GRBs are believed to be produced in the final merger of compact object (neutron star-neutron star or neutron star-black hole) binaries, though other possible progenitors are known to exist. The short initial spike of a giant flare from a Soft Gamma Repeater (SGR) such as the December 27th 2004 event from SGR1806-20 would have been detectable by BATSE as a short GRB if it occurred in a galaxy within ~30-50 Mpc (assuming a distance to SGR1806-20 of 15 kpc). Using the observed luminosities and rates of Galactic SGR giant flares, as well as theoretical predictions for the rate of binary mergers, we investigate the ability of plausible Luminosity Functions (LF), singly and in combination, to reproduce our observed correlations and a cosmological S-GRB population. We find the correlations are best explained by a separate population of lower luminosity S-GRBs, with properties consistent with them being due to giant flares from extra-galactic SGRs. Overall predicted number counts are a good fit to the observed BATSE number counts, and furthermore, the wider redshift distribution is consistent with the early Swift S-GRB redshift distribution. The three closest GRBs which have been observed to date were all long duration bursts, and we have therefore also searched for cross-correlation signals between the BATSE long GRBs and local galaxies. The three nearby bursts shared several similar properties such as being under-luminous, spectrally soft and of low variability. We have therefore also investigated a subset of L-GRBs with light curve properties similar to these known nearby bursts. The whole sample is found to exhibit a correlation level consistent with zero (1 sigma upper limit=10%, equivalent to 144 bursts) out to a radius of ~155 Mpc, but a spectrally soft, low observed fluence and low variability subset shows a correlation level of 28%+/-16% (=50+/-28 bursts) within 155 Mpc. These results are consistent with low-luminosity, low-variability bursts being a separate sub-class of L-GRBs which may be much more prevalent in the local Universe than their high-luminosity, cosmologically distant counterparts. To investigate this further, we once again examined plausible luminosity functions for single and dual high and low luminosity populations, based on observed intrinsic rates from the literature. The local population was once again found only to be produced to a sufficient level (while maintaining consistency with the observed overall number counts) by a separate low luminosity population with intrinsic rates several hundred times greater than their cosmological counterparts. Constraining the models via the Swift overall redshift distribution instead of threshold-adjusted BATSE number counts showed that the dual LF models were able to produce excellent fits to the entire redshift distribution while adequately reproducing a local population. Finally, suggestions are made as to the direction future work may follow in order to build on these initial investigations, as well as to how observations with future missions and detectors such as Fermi (formerly GLAST), Advanced LIGO and LOFAR may shed further light on nearby GRBs.
373

[en] A SMOOTH TRANSITION PERIODIC AUTO REGRESSIVE MODEL FOR SHORT TERM ELECTRICITY LOAD FORECAST / [pt] UM MODELO DE MÚLTIPLOS REGIMES AUTO REGRESSIVO PERIÓDICO COM TRANSIÇÃO SUAVE APLICADO A PREVISÃO DE CURTO PRAZO DE CARGA DE ENERGIA ELÉTRICA

LUIZ FELIPE MOREIRA DO AMARAL 16 May 2007 (has links)
[pt] Essa tese considera um modelo não linear para se obter previsões de curto prazo de carga de energia elétrica. O modelo combina um modelo de múltiplos regimes auto-regressivo com transição suave com um periódico auto-regressivo criando o modelo de múltiplos regimes periódico com transição suave (STPAR). Um método de construção do modelo é desenvolvido com métodos estatísticos simples e um teste de linearidade contra a hipótese de modelo periódico autoregressivo com transição suave. Outros dois destes foram elaborados para se avaliar o modelo estimado: um teste de Multiplicador de Lagrange (LM) para a hipótese de auto-correlação serial dos resíduos e outro teste LM para a hipótese de não linearidade remanescente. Um experimento de Monte Carlo foi implementado para avaliar a performance dos testes propostos. Estimação por mínimos quadrados não lineares é considerado. Finalmente, dados de carga de energia elétrica do estado de New South Wales na Austrália são apresentados e foram usados como exemplo real. Outros modelos foram utilizados para comparar a performance do modelo. / [en] This thesis considers a non linear approach to obtain short term forecast for electricity load. The model combines a smooth transition autoregressive process with a periodic autoregressive time series model, creating the Smooth Transition Periodic Autoregressive (STPAR) model. A model-building procedure is developed and a linearity test against smooth transition periodic auto-regressive is proposed. Other two tests were created to evaluate the model: a Lagrange multiplier (LM) test for the hypothesis of no error autocorrelation and LM-type test for the hypothesis of no remaining non-linearity. A Monte Carlo experiment was implemented to evaluate the performance of the proposed tests. Estimation by nonlinear least squares is considered. Finally, load data from New South Wales State in Australia`s electricity retail market is presented and will be used as a real example. Other models were used to compare the performance of the proposes model.
374

Soluções semi-analíticas para objetos astrofísicos compactos / Semi-analytical solutions for a compact astrophysical object

Avellar, Marcio Guilherme Bronzato de 12 March 2008 (has links)
Nesta dissertação, estuda-se estrelas compactas constituídas por uma forma estável do plasma ultra-relativístico de {\\it quarks} e glúons, a {\\it strange quark matter} ou matéria estranha, com pequena fração de elétrons para manter a neutralidade de carga. São abordadas, aqui, soluções matemáticas razoáveis que descrevem com simplicidade e agilidade certas propriedade dessas estrelas, a começar pela importantíssima relação massa-raio. Um perfil gaussiano para a densidade de energia foi escolhido como ponto de partida para contruir uma solução matemática para o problema e são apresentadas as motivações para tal escolha. Prova-se que o perfil escolhido não soluciona as Equações de Einstein exatamente e uma solução aproximada é fornecida. A seguir, as conhecidas soluções Tolman IV e Buchdahl I foram utilizadas para modelar uma estrela estranha com base no estudo de Alcock, Farhi e Olinto. Discute-se, ainda, como foi redescoberta a solução exata de Finch e Skea e discute-se, também, a solução exata para uma estrela de {\\it quarks} de Komathiraj e Maharaj, construída para um problema ligeiramente diferente, que incluía a existência de um campo elétrico. Conclui-se o trabalho comparando os resultados numéricos de Alcock, Farhi e Olinto com a solução aproximada aqui desenvolvida, apresentando o intervalo de validade desta solução. Além disso, são feitas comparações entre as diferentes soluções exatas e as características que cada uma delas exibe, e discute-se qual delas deve-se utilizar, tendo em mente que característica da estrela estranha se quer estudar. Os caminhos existentes para solucionar as Equações de Einstein, quando se quer modelar um objeto compacto, são discutidos e apontam-se quais os problemas que alguém encontrará ao seguir cada caminho. Por fim, relaciona-se a construção da relação massa-raio com a diferenciação dos tipos de objetos compactos que podem, em princípio, existir. / In this dissertation we study compact stars constituted by a stable form of ultra-relativistic quark-gluon plasma, the strange matter, with a small fraction of electrons to keep the neutrality of charge. We address here reasonable mathematical solutions that describe with simplicity and agility some properties of these stars, beginning by the important mass-radius relationship. A gaussian energy density profile was chosen as the starting point for the construction of a mathematical solution for this problem and the motivations for this choice was presented. We prove that this profile is not an exact solution for the Einstein Field Equations and an approximated solution is presented. Following, the previous known solutions of Tolman IV and Buchdahl I were used to model a strange star, based on the work of Alcock, Farhi and Olinto. We discuss the rediscovery of the exact solution of Finch and Skea and also the exact solution for a quark star by Komathiraj and Maharaj, constructed to a problem slightly different, that includes the existence of an electric field. We conclude this work comparing the numerical results of Alcock, Farhi and Olinto with the approximated solution here developed, presenting the range of validity of this solution. Furthermore, comparisons were made between the different exact solutions and the features displayed by each one and we discuss which solution must be used when one have in mind which features of the strange star one wants to study. The existent ways for solving the Einstein Equations when we want to model a compact star are discussed and we point out the problems that one will find in following each way. At last, we make a relation between the mass-radius relationship and the differentiation of the many types of compact objects that could, in principle, exist.
375

Avaliação do Star Schema Benchmark aplicado a bancos de dados NoSQL distribuídos e orientados a colunas / Evaluation of the Star Schema Benchmark applied to NoSQL column-oriented distributed databases systems

Scabora, Lucas de Carvalho 06 May 2016 (has links)
Com o crescimento do volume de dados manipulado por aplicações de data warehousing, soluções centralizadas tornam-se muito custosas e enfrentam dificuldades para tratar a escalabilidade do volume de dados. Nesse sentido, existe a necessidade tanto de se armazenar grandes volumes de dados quanto de se realizar consultas analíticas (ou seja, consultas OLAP) sobre esses dados volumosos de forma eficiente. Isso pode ser facilitado por cenários caracterizados pelo uso de bancos de dados NoSQL gerenciados em ambientes paralelos e distribuídos. Dentre os desafios relacionados a esses cenários, destaca-se a necessidade de se promover uma análise de desempenho de aplicações de data warehousing que armazenam os dados do data warehouse (DW) em bancos de dados NoSQL orientados a colunas. A análise experimental e padronizada de diferentes sistemas é realizada por meio de ferramentas denominadas benchmarks. Entretanto, benchmarks para DW foram desenvolvidos majoritariamente para bancos de dados relacionais e ambientes centralizados. Nesta pesquisa de mestrado são investigadas formas de se estender o Star Schema Benchmark (SSB), um benchmark de DW centralizado, para o banco de dados NoSQL distribuído e orientado a colunas HBase. São realizadas propostas e análises principalmente baseadas em testes de desempenho experimentais considerando cada uma das quatro etapas de um benchmark, ou seja, esquema e carga de trabalho, geração de dados, parâmetros e métricas, e validação. Os principais resultados obtidos pelo desenvolvimento do trabalho são: (i) proposta do esquema FactDate, o qual otimiza consultas que acessam poucas dimensões do DW; (ii) investigação da aplicabilidade de diferentes esquemas a cenários empresariais distintos; (iii) proposta de duas consultas adicionais à carga de trabalho do SSB; (iv) análise da distribuição dos dados gerados pelo SSB, verificando se os dados agregados pelas consultas OLAP estão balanceados entre os nós de um cluster; (v) investigação da influência de três importantes parâmetros do framework Hadoop MapReduce no processamento de consultas OLAP; (vi) avaliação da relação entre o desempenho de consultas OLAP e a quantidade de nós que compõem um cluster; e (vii) proposta do uso de visões materializadas hierárquicas, por meio do framework Spark, para otimizar o desempenho no processamento de consultas OLAP consecutivas que requerem a análise de dados em níveis progressivamente mais ou menos detalhados. Os resultados obtidos representam descobertas importantes que visam possibilitar a proposta futura de um benchmark para DWs armazenados em bancos de dados NoSQL dentro de ambientes paralelos e distribuídos. / Due to the explosive increase in data volume, centralized data warehousing applications become very costly and are facing several problems to deal with data scalability. This is related to the fact that these applications need to store huge volumes of data and to perform analytical queries (i.e., OLAP queries) against these voluminous data efficiently. One solution is to employ scenarios characterized by the use of NoSQL databases managed in parallel and distributed environments. Among the challenges related to these scenarios, there is a need to investigate the performance of data warehousing applications that store the data warehouse (DW) in column-oriented NoSQL databases. In this context, benchmarks are widely used to perform standard and experimental analysis of distinct systems. However, most of the benchmarks for DW focus on relational database systems and centralized environments. In this masters research, we investigate how to extend the Star Schema Benchmark (SSB), which was proposed for centralized DWs, to the distributed and column-oriented NoSQL database HBase. We introduce proposals and analysis mainly based on experimental performance tests considering each one of the four steps of a benchmark, i.e. schema and workload, data generation, parameters and metrics, and validation. The main results described in this masters research are described as follows: (i) proposal of the FactDate schema, which optimizes queries that access few dimensions of the DW; (ii) investigation of the applicability of different schemas for different business scenarios; (iii) proposal of two additional queries to the SSB workload; (iv) analysis of the data distribution generated by the SSB, verifying if the data aggregated by OLAP queries are balanced between the nodes of a cluster; (v) investigation of the influence caused by three important parameters of the Hadoop MapReduce framework in the OLAP query processing; (vi) evaluation of the relationship between the OLAP query performance and the number of nodes of a cluster; and (vii) employment of hierarchical materialized views using the Spark framework to optimize the processing performance of consecutive OLAP queries that require progressively more or less aggregated data. These results represent important findings that enable the future proposal of a benchmark for DWs stored in NoSQL databases and managed in parallel and distributed environments.
376

A crítica cinematográfica e o star system nas revistas de fãs: A Cena Muda e Cinelândia (1952-1955) / A crítica cinematográfica e o star system nas revistas de fãs: A Cena Muda e Cinelândia (1952-1955)

Adamatti, Margarida Maria 06 March 2009 (has links)
O objetivo desta dissertação é analisar a cobertura jornalística ao cinema brasileiro durante os anos cinqüenta em duas revistas de fãs: A Cena Muda (1921-1955) e Cinelândia (1952-1967), avaliando a estrutura da crítica cinematográfica e seu papel como geradora do star system brasileiro. A análise do material de nosso estudo congrega os anos de 1952 a 1955, único período em que as duas publicações coexistiram. Através da análise comparativa com a cobertura ao cinema de Hollywood, traçamos os paralelos da configuração do estrelismo brasileiro, com especial atenção às estratégias de legitimação do sistema para aumentar o interesse dos leitores e às peculiaridades da crítica em lidar com o star system. / This dissertation has by finality the study of the journalistic coverage to the brazilian cinema during the fifties in two fan magazines: A Cena Muda (1921-1955) and Cinelândia (1952-1967) to assess the structure of the critic cinematograph and their role as producer of brazilian star system. The material analysis of our study assembles the years of 1952 to 1955, only period in which both publications coexisted. Through the comparative analysis with the coverage of the Hollywood cinema, we draw the parallel with the configurations of brazilian star system, with special interest to the system legitimacy strategies to increase the readers interest and to the peculiarities of the critic to handle with the star system.
377

Spatially-resolved studies of nearby star-forming galaxies

Kumari, Nimisha January 2018 (has links)
Spatially-resolved studies of nearby star-forming galaxies are essential to understand various physical and chemical phenomena at play in the interstellar medium in the galaxies, and consequently to obtain a comprehensive picture of galaxy formation and evolution. In this thesis, I perform spatially-resolved analyses of chemical abundances and star-formation in nearby star-forming galaxies - blue compact dwarf galaxies (BCDs) and spiral galaxies. I map various properties of H II regions and the surrounding gas within three BCDs, using integral field spectroscopic (IFS) data from the Gemini Multi-Object Spectrograph-North. While answering questions related to chemical homogeneity, ionisation mechanisms and stellar populations within BCDs, I address more profound issues, which go beyond the characterisation of studied BCDs and aim to explain global phenomena with broader implications. The BCD NGC 4449 hosts a metal-poor central star-forming region, which I explain by various scenarios related to the interplay between star-formation, metal-distribution and gas dynamics within galaxies. The BCD NGC 4670 shows an unusual negative relationship between the nitrogen-to-oxygen ratio and oxygen abundance at spatially-resolved scales. I explore this relation with chemical evolution models and by comparison to other star-forming galaxies and suggest that nitrogen enrichment, variations in star-formation efficiency or hydrodynamical effects may be responsible for the observed relation. For another BCD, SBS 1415+437, the spatially-resolved abundances on average agree with the integrated abundance, implying that low-redshift spatially-resolved results may be directly compared with unresolved high-redshift results. I study spiral galaxies to address long-standing issues related to the reliability of metallicity calibrators and the Schmidt Law of star-formation. Using IFS data of twenty-four spiral galaxies taken with the Multi-Unit Spectroscopic Explorer, I find that the current strong-line metallicity calibrators for H II regions are unsuitable for regions dominated by diffuse ionised gas (DIG). I devise new recipes for estimating the metal-content of the DIG. For another set of nine spiral galaxies, I use multi-wavelength data to show that the spatially-resolved Schmidt relation is very sensitive to the consideration of diffuse background, which is a component unrelated to the current star-formation. Removal of this component from the SFR tracers and the atomic gas results in similar local and global Schmidt relation. To conclude, the spatially-resolved analyses presented in this thesis have led to discoveries and further questions, which I will address in my ongoing and future works.
378

Properties of turbulent star-forming clusters : models versus observations

Schmeja, Stefan January 2006 (has links)
<p> Stars are born in turbulent molecular clouds that fragment and collapse under the influence of their own gravity, forming a cluster of hundred or more stars. The star formation process is controlled by the interplay between supersonic turbulence and gravity. In this work, the properties of stellar clusters created by numerical simulations of gravoturbulent fragmentation are compared to those from observations. This includes the analysis of properties of individual protostars as well as statistical properties of the entire cluster. </p> <p> It is demonstrated that protostellar mass accretion is a highly dynamical and time-variant process. The peak accretion rate is reached shortly after the formation of the protostellar core. It is about one order of magnitude higher than the constant accretion rate predicted by the collapse of a classical singular isothermal sphere, in agreement with the observations. </p> <p> For a more reasonable comparison, the model accretion rates are converted to the observables bolometric temperature, bolometric luminosity, and envelope mass. The accretion rates from the simulations are used as input for an evolutionary scheme. The resulting distribution in the T<sub>bol</sub>-L<sub>bol</sub>-M<sub>env</sub> parameter space is then compared to observational data by means of a 3D Kolmogorov-Smirnov test. The highest probability found that the distributions of model tracks and observational data points are drawn from the same population is 70%. </p> <p> The ratios of objects belonging to different evolutionary classes in observed star-forming clusters are compared to the temporal evolution of the gravoturbulent models in order to estimate the evolutionary stage of a cluster. While it is difficult to estimate absolute ages, the realtive numbers of young stars reveal the evolutionary status of a cluster with respect to other clusters. The sequence shows Serpens as the youngest and IC 348 as the most evolved of the investigated clusters. </p> <p> Finally the structures of young star clusters are investigated by applying different statistical methods like the normalised mean correlation length and the minimum spanning tree technique and by a newly defined measure for the cluster elongation. The clustering parameters of the model clusters correspond in many cases well to those from observed ones. The temporal evolution of the clustering parameters shows that the star cluster builds up from several subclusters and evolves to a more centrally concentrated cluster, while the cluster expands slower than new stars are formed. </p> / <p>Sterne entstehen im Inneren von turbulenten Molekülwolken, die unter dem Einfluss ihrer eigenen Gravitation fragmentieren und kollabieren. So entsteht ein Sternhaufen aus hundert oder mehr Objekten. Der Sternentstehungsprozess wird durch das Wechselspiel von Überschallturbulenz und Gravitation reguliert. In dieser Arbeit werden verschiedene Eigenschaften solcher Sternhaufen, die mit Hilfe von numerischen Simulationen modelliert wurden, untersucht und mit Beobachtungsdaten verglichen. Dabei handelt es sich sowohl um Eigenschaften einzelner Protosterne, als auch um statistische Parameter des Sternhaufens als Ganzes.</p> <p>Es wird gezeigt, dass die Massenakkretion von Protosternen ein höchst dynamischer und zeitabhängiger Prozess ist. Die maximale Akkretionsrate wird kurz nach der Bildung des Protosterns erreicht, bevor sie annähernd exponentiell abfällt. Sie ist, in Übereinstimmung mit Beobachtungen, etwa um eine Größenordnung höher als die konstante Rate in den klassischen Modellen.</p> <p>Um die Akkretionsraten der Modelle zuverlässiger vergleichen zu können, werden sie mit Hilfe eines Evolutionsschemas in besser beobachtbare Parameter wie bolometrische Temperatur und Leuchtkraft sowie Hüllenmasse umgewandelt. Die dreidimensionale Verteilung dieser Parameter wird anschließend mittels eines Kolmogorov-Smirnov-Tests mit Beobachtungsdaten verglichen.</p> <p>Die relative Anzahl junger Sterne in verschiedenen Entwicklungsstadien wird mit der zeitlichen Entwicklung der Modelle verglichen, um so den Entwicklungsstand des Sternhaufens abschätzen zu können. Während eine genaue Altersbestimmung schwierig ist, kann der Entwicklungsstand eines Haufens relativ zu anderen gut ermittelt werden. Von den untersuchten Objekten stellt sich Serpens als der jüngste und IC 348 als der am weitesten entwickelte Sternhaufen heraus.</p> <p>Zuletzt werden die Strukturen von jungen Sternhaufen an Hand verschiedener statistischer Methoden und eines neuen Maßes für die Elongation eines Haufens untersucht. Auch hier zeigen die Parameter der Modelle eine gute Übereinstimmung mit solchen von beobachteten Objekten, insbesondere, wenn beide eine ähnliche Elongation aufweisen. Die zeitliche Entwicklung der Parameter zeigt, dass sich ein Sternhaufen aus mehreren kleineren Gruppen bildet, die zusammenwachsen und einen zum Zentrum hin konzentrierten Haufen bilden. Dabei werden neue Sterne schneller gebildet als sich der Sternhaufen ausdehnt.</p>
379

Röda eller blå stjärnor : Politiska budskap i Star Trek / Red or Blue Stars : Political Messages in Star Trek

Grönberg, Anders, Lundberg, Emanuel January 2009 (has links)
Denna uppsats undersöker TV-serien Star Treks värderingar ur ett politiskt ideologiskt perspektiv. Star Trek är en amerikansk science fiction-serie som skapades av Gene Roddenberry i mitten av 1960-talet. Frågeställningarna behandlar om det finns politiskt relaterade värderingar framställda i Star Trek, vilken politisk ideologi som mest liknar värderingarna i serien, och om det går att tolka det som om Star Trek har en ideologisk värdegrund. Med hjälp av dagordningsteori, kritisk medieteori och teorier om budskap diskuteras TV-bolagens makt över seriens innehåll. De politiska ideologierna konservatism, liberalism och socialism har valts för att kunna jämföras med analysmaterialet. Sex avsnitt från originalserien analyserades med hjälp av en hermeneutik och kvalitativ metod för att bäst kunna få insikt i materialet. Den faktiska analysen har skett med den narratologiska aktantmodellen samt närläsning baserad på kritisk medieteori, där citat bryts ut och tolkas. Resultaten har delats in i tre kategorier, nämligen ekonomi, människosyn och samhällsstruktur för att underlätta sammanställandet. Undersökningen visar att det finns både positivt och negativt framställda värderingar i Star Trek.Ingen politisk ideologi framställs som denenda rätta, men tendensen är att konservatism är minst propagerat för, medan den demokratiska varianten av socialism verkar förespråkas mest. Att resultatet blev splittrat kan härledas till att medieföretagen har stort inflytande över innehållet och att det är svårt att konsekvent framhäva en politisk ideologi i en TV-serie som Star Trek. Detta till följd av formatet på serierna och att de amerikanska TV-bolagen sätter speciella kommersiella krav på produktionen. Det reflekteras också över att politiska värderingar i ett underhållningmedium kan vara effektiva eftersom de politiska budskapen inte har fokus utan intas indirekt. / This thesis examines the values in the TV-series called Star Trek from a political perspective. Star Trek is an American science fiction-series that was created byGene Roddenberry during the mid-1960s. The queries are about whether or not political values are expressed in Star Trek, what political ideology is coherent with those, and if it is possible to interpret this as if Star Trek has an actual politically ideological fundament. Media power over content has been discussed, and because of this there has been made use of critical media theories together with theory of agenda setting and message. The political ideologies of conservatism, liberalism and socialism have been chosen to be compared with the material of analysis.Seven episodes of the original series have been chosen to get a good view of the material by the use of hermeneutic and qualitative research methodology.The analysis was done with the narratological actant model plus a method based on critical media theory, where quotes are being extracted and interpreted. The results have been categorised as either relating to economics, view of mankind or structure of society. The examination shows that there are both positively and negatively described values in Star Trek. No distinct political ideology is being clearly advocated, but there are tendencies for negative views of conservative values aswell as a positive coherence with democratic socialism. The results were difficult to conclude, and this could point towards that the media companies have big influence over their transmitted contents, and that it is difficult to consistently highlight politically ideological values in a television series like Star Trek. This is because the format of TV-series set by american commercial interests puts certain demands on productions. There are reflections about that political values in a medium of entertainment could be effective since the political messages are not in focus but received indirectly.
380

Impact of Continuous Commissioning® on the Energy Star® Rating of Hospitals and Office Buildings

Kulkarni, Aditya Arun 2011 December 1900 (has links)
Re-commissioning, retro-commissioning, Continuous Commissioning® (CC®) are examples of successful systematic processes implemented in buildings to reduce overall building energy consumption, and improve efficiency of systems and their operations and control. The impact of the Continuous Commissioning® Process on the Energy Star® Rating (ESR) of office buildings and hospitals is examined in this thesis. The improvement in performance of a building, and subsequently its ESR, is found to be influenced by its initial ESR, while its location has no impact on improvement. The improvement in ESR is observed to be almost linearly proportional to the percentage of energy saved. For 10% - 20% reductions in energy use typical of the CC® process, the ESR is increased by 10-19 ESR ranks for office buildings and by 13 - 26 ESR ranks for hospitals. The CC® process is found to potentially enable an office building of average initial ESR of 62 and a hospital of average initial ESR of 55, located anywhere in the US, to be eligible to achieve ESR of 75 and consequently the Energy Star recognition. The improvement of ESR is a function of the initial ESR and the building type; hence it is observed to be different for hospitals and office buildings in the study. For hospital and office building models occupying 100,000 ft² of floor area each, a difference of about 30% in the ESR improvement (greater for hospitals) is observed. The energy intensities may be different for buildings with same ESRs that have different location and/or type. An averaged maximum difference of energy intensity of approximately 10% is observed to exist for identical buildings and of the same type but located at different locations. Hospitals are observed to be more than twice as energy intensive as office buildings for the same location and equal ESRs. ESR plotted against % energy savings at site reveals the stepped nature of ESR system. At specific initial ESR and corresponding % savings a reduction of up to approximately 1% for office buildings and up to 1.5% for hospitals does not change the respective ESRs for the model set of buildings in the study.

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