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Optimization of Massive MIMO Systems for 5G NetworksChataut, Robin 08 1900 (has links)
In the first part of the dissertation, we provide an extensive overview of sub-6 GHz wireless access technology known as massive multiple-input multiple-output (MIMO) systems, highlighting its benefits, deployment challenges, and the key enabling technologies envisaged for 5G networks. We investigate the fundamental issues that degrade the performance of massive MIMO systems such as pilot contamination, precoding, user scheduling, and signal detection. In the second part, we optimize the performance of the massive MIMO system by proposing several algorithms, system designs, and hardware architectures. To mitigate the effect of pilot contamination, we propose a pilot reuse factor scheme based on the user environment and the number of active users. The results through simulations show that the proposed scheme ensures the system always operates at maximal spectral efficiency and achieves higher throughput. To address the user scheduling problem, we propose two user scheduling algorithms bases upon the measured channel gain. The simulation results show that our proposed user scheduling algorithms achieve better error performance, improve sum capacity and throughput, and guarantee fairness among the users. To address the uplink signal detection challenge in the massive MIMO systems, we propose four algorithms and their system designs. We show through simulations that the proposed algorithms are computationally efficient and can achieve near-optimal bit error rate performance. Additionally, we propose hardware architectures for all the proposed algorithms to identify the required physical components and their interrelationships.
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A state management and persistency architecture for peer-to-peer massively multi-user virtual environmentsGilmore, John Sebastian 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Recently, there has been significant research focus on Peer-to-Peer (P2P) Massively
Multi-user Virtual Environments (MMVEs). A number of architectures have been
presented in the literature to implement the P2P approach. One aspect that has
not received sufficient attention in these architectures is state management and
state persistency in P2P MMVEs. This work presents and simulates a novel state
management and persistency architecture, called Pithos.
In order to design the architecture, an investigation is performed into state consistency
architectures, into which the state management and persistency architecture
should fit. A novel generic state consistency model is proposed that encapsulated all
state consistency models reviewed. The requirements for state management and persistency
architectures, identified during the review of state consistency models, are
used to review state management and persistency architectures currently receiving
research attention.
Identifying some deficiencies present in current designs, such as lack of fairness,
responsiveness and scalability, a novel state management and persistency architecture,
called Pithos, is designed. Pithos is a reliable, responsive, secure, fair and
scalable distributed storage system, ideally suited to P2P MMVEs. Pithos is implemented
in Oversim, which runs on the Omnet++ network simulator. An evaluation
of Pithos is performed to verify that it satisfies the identified requirements.
It is found that the reliability of Pithos depends heavily on object lifetimes. If an
object lives longer on average, retrieval requests are more reliable. An investigation
is performed into the factors influencing object lifetime. A novel Markov chain model
is proposed which allows for the prediction of objects lifetimes in any finite sized
network, for a given amount of redundancy, node lifetime characteristics and object
repair rate. / AFRIKAANSE OPSOMMING: Onlangs is daar ’n beduidende navorsingsfokus op Eweknie Massiewe Multi-gebruiker
Virtuele Omgewings (MMVOs). ’n Aantal argitekture is in die literatuur beskikbaar
wat die eweknie benadering voorstel. Een aspek wat nie voldoende aandag
ontvang in hierdie argitekture nie is toestandsbestuur en toestandsvolharding in
eweknie MMVOs. Hierdie werk ontwerp en simuleer ’n nuwe toestandsbestuur- en
toestandsvolhardingargitektuur genaamd Pithos.
Ten einde die argitektuur te ontwerp is ’n ondersoek uitgevoer in toestandskonsekwentheidargitekture,
waarin die toestandsbestuur- en toestandsvolhardingargitektuur
moet pas. ’n Nuwe generiese toestandskonsekwentheidargitektuur word voorgestel
wat alle hersiene toestandskonsekwentheid argitekture vervat. Die vereistes vir
die toestandsbestuur- en toestandsvolhardingargitekture, geidentifiseer tydens die
hersiening van die toestandskonsekwentheidargitekture, word gebruik om toestandsbestuuren
toestandsvolhardingargitekture te hersien wat tans navorsingsaandag geniet.
Identifisering van sekere leemtes teenwoordig in die huidige ontwerpe, soos ’n
gebrek aan regverdigheid, responsiwiteit en skaleerbaarheid, lei tot die ontwerp van
’n nuwe toestandsbestuur- en toestandsvolhardingargitektuur wat Pithos genoem
word. Pithos is ’n betroubare, responsiewe, veilige, regverdige en skaleerbare verspreide
stoorstelsel, ideaal geskik is vir eweknie MMVOs. Pithos word geïmplementeer
in Oversim, wat loop op die Omnet++ netwerk simulator. ’n Evaluering
van Pithos word uitgevoer om te verifieer dat dit voldoen aan die geïdentifiseerde
behoeftes. Daar is gevind dat die betroubaarheid van Pithos afhang van die objek leeftyd.
As ’n objek gemiddeld langer leef, dan is herwinning versoeke meer betroubaar. ’n
Ondersoek word uitgevoer na die faktore wat die objek leeftyd beïnvloed. ’n Nuwe
Markov ketting model word voorgestel wat voorsiening maak vir die voorspelling van
objek leeftye in eindige grootte netwerke, vir gegewe hoeveelhede van oortolligheid,
nodus leeftyd eienskappe en objek herstelkoers.
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Cosmologie et modifications à grandes distances de l'interaction gravitationnelleZiour, Riad 19 January 2010 (has links) (PDF)
Dans le cadre de la relativité générale, l'observation de la phase actuelle d'accélération de l'expansion de l'Univers soulève de nombreuses questions car elle semble indiquer l'existence d'une "énergie noire" dont on ne connaît pas la nature. Afin de pouvoir expliquer l'accélération de l'Univers sans énergie noire, d'autres théories de la gravité ont été proposées. Cette thèse est consacrée à l'étude de certaines de ces théories de gravité modifiée, ainsi qu'aux méthodes d'observation qui peuvent les contraindre. La première partie de cette thèse présente un panorama des théories de gravité modifiée ainsi que leurs motivations. La seconde partie analyse les théories de gravité massive et le mécanisme dit « de Vainshtein », qui permet à certaines solutions de la gravité massive de différer fortement de la relativité générale aux échelles cosmologiques tout en satisfaisant les contraintes expérimentales au sein du système solaire. La validité de ce mécanisme y est démontré pour la première fois, au travers de l'étude de certaines solutions à symétrie sphérique. La troisième partie traite des modifications scalaires de la gravité ; un nouveau modèle de gravité scalaire y est notamment proposé, inspiré du mécanisme de Vainshtein de la gravité massive. Enfin, la quatrième partie décrit les différentes observations locales, astrophysiques et cosmologiques, susceptibles de contraindre les théories de gravité modifiée.
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Threelogy in two parts 3-algebras in BLG models and a study of TMG solutionsRitter, Patricia Diana January 2012 (has links)
This thesis is a review of research done over the course of the past 4 years, divided into two unrelated parts. The rst is set in the context of Bagger-Lambert-Gustavsson models, based on 3-Lie algebras. In particular I will describe theories with metric 3-algebras of inde nite signature: these present elds with negative kinetic terms. The problem can be solved by gaugeing away the non-physical degrees of freedom, to obtain other well understood theories. I will show how this procedure can be easily applied for 3-algebra metrics of any inde nite signature. Part II of this thesis focuses on solutions of topologically massive gravity (TMG): particular attention is devoted to warped AdS3 black holes, which are discussed in great detail. I will present a novel analysis of the near horizon geometries of these solutions. I further propose an approach for searching for new solutions to 3-dimensional gravity based on conformal symmetry. This approach is able to yield most of the known axisymmetric stationary TMG backgrounds.
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The use of massive multiplayer online games to evaluate C4I systemsJuve, Kambra R. 03 1900 (has links)
Approved for public release, distribution is unlimited / Human Systems Integration Report / In the past few years, Massive Multiplayer Online Games (MMOG) have gained in popularity in the gaming industry, the public and the Department of Defense. Improvements to computer technology and the increased data transfer rate over networks have caused the potential applications for networked environments to blossom. MMOGs are a product of these improvements, as technological advancements have made it possible for the masses to gain access to virtual environments and participate. The ability to communicate and interact within the virtual environment has the potential to make MMOG technology an ideal tool for evaluating C4I systems. The design and evaluation of C4I systems with MMOGs has the potential to allow for exploration in the areas of warfighter effectiveness, emergent behavior, collective decision making, human systems integration and effective information flow. This thesis strives to illustrate how a C4I system modeled in an MMOG can aid designers in gathering insights on the effectiveness of the system in various combat situations. The insights will be gathered through the interactions of players with the modeled system in the virtual environment. The human interaction with the modeled C4I system provides the ability to capture the effects of the C4I system on the warfighter. The resultant effects of the C4I system on the warfighter directly contribute to the overall combat effectiveness of the deployed military forces. The background of MMOGs and C4I systems, and attributes of MMOGs that are desirable in evaluating C4I systems are introduced and discussed. FORCEnet, a global C4I architecture still in the conceptual phase is then used as an example to illustrate the potential rewards to using MMOGs to evaluate C4I systems. / Lieutenant, United States Navy
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Studium slévárenských vad v masivních odlitcích / Study of foundry defects in heavy castingsČech, Jan January 2013 (has links)
A massive castings defects are examined in this doctoral thesis, specialise in steels passing through peritectic transformation. There are typical types of defects at massive steel castings, as contrasted to „ordinary“ internal and surface ones. For massive steel castings are typical defects under feeders like conchoidal fractures, segregations, microporesities, reoxidation products. Combination of Al and Zr is an ordinary final deoxidation of EOP and LF steel for castings in ŽĎAS a.s. foundry. The aim of Al + Zr combination was to both deep deoxidation by Al (decrease of bubbles risk) and denitrification by Zr (decrease of conchoidal fractures). This theses refute premission mentioned above and verified persisting risk of defects under massive feeders, even though Al + Zr deoxidation is used. A final deoxidation by increased amount of Al was examinated, in combination with other deoxidation agents. Castings had 11 [cm] maximal modulus, and occurence of conchoidal fracture, reoxidation products and primary austenite grain size was evaluated. A selected optimal final deoxidations (Al, Al+Ti, Al+Zr) as a result from experiment described above, were evaluated on castings with 15 [cm] maximal modulus. The result of experiment is, that is not possible to repeatedly produce massive steel casting using EOP metallurgical equipment without defects under feeders, despite of deoxidation and pouring temperature optimalization. The defect indications look like conchoidal fracture, but there are microporesity and impurities instead. Finally, castings with maximal modulus 15 [cm] were produced using so called secondary metallurgy (LF, VD). Secondary metallurgy allowed to both significant decrease of sulfur and degassing of melted metal. Only this metallurgical procedure guarantees production of heavy steel castings without typical defects under massive feeders
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Effective and unsupervised fractal-based feature selection for very large datasets: removing linear and non-linear attribute correlations / Seleção de atributos efetiva e não-supervisionada em grandes bases de dados: aplicando a Teoria de Fractais para remover correlações lineares e não-linearesFraideinberze, Antonio Canabrava 04 September 2017 (has links)
Given a very large dataset of moderate-to-high dimensionality, how to mine useful patterns from it? In such cases, dimensionality reduction is essential to overcome the well-known curse of dimensionality. Although there exist algorithms to reduce the dimensionality of Big Data, unfortunately, they all fail to identify/eliminate non-linear correlations that may occur between the attributes. This MSc work tackles the problem by exploring concepts of the Fractal Theory and massive parallel processing to present Curl-Remover, a novel dimensionality reduction technique for very large datasets. Our contributions are: (a) Curl-Remover eliminates linear and non-linear attribute correlations as well as irrelevant attributes; (b) it is unsupervised and suits for analytical tasks in general not only classification; (c) it presents linear scale-up on both the data size and the number of machines used; (d) it does not require the user to guess the number of attributes to be removed, and; (e) it preserves the attributes semantics by performing feature selection, not feature extraction. We executed experiments on synthetic and real data spanning up to 1.1 billion points, and report that our proposed Curl-Remover outperformed two PCA-based algorithms from the state-of-the-art, being in average up to 8% more accurate. / Dada uma grande base de dados de dimensionalidade moderada a alta, como identificar padrões úteis nos objetos de dados? Nesses casos, a redução de dimensionalidade é essencial para superar um fenômeno conhecido na literatura como a maldição da alta dimensionalidade. Embora existam algoritmos capazes de reduzir a dimensionalidade de conjuntos de dados na escala de Terabytes, infelizmente, todos falham em relação à identificação/eliminação de correlações não lineares entre os atributos. Este trabalho de Mestrado trata o problema explorando conceitos da Teoria de Fractais e processamento paralelo em massa para apresentar Curl-Remover, uma nova técnica de redução de dimensionalidade bem adequada ao pré-processamento de Big Data. Suas principais contribuições são: (a) Curl-Remover elimina correlações lineares e não lineares entre atributos, bem como atributos irrelevantes; (b) não depende de supervisão do usuário e é útil para tarefas analíticas em geral não apenas para a classificação; (c) apresenta escalabilidade linear tanto em relação ao número de objetos de dados quanto ao número de máquinas utilizadas; (d) não requer que o usuário sugira um número de atributos para serem removidos, e; (e) mantêm a semântica dos atributos por ser uma técnica de seleção de atributos, não de extração de atributos. Experimentos foram executados em conjuntos de dados sintéticos e reais contendo até 1,1 bilhões de pontos, e a nova técnica Curl-Remover apresentou desempenho superior comparada a dois algoritmos do estado da arte baseados em PCA, obtendo em média até 8% a mais em acurácia de resultados.
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The Red Supergiants in the Supermassive Stellar Cluster Westerlund 1 / As Supergigantes Vermelhas no Aglomerado Estelar Supermassivo Westerlund 1Arévalo, Aura de Las Estrellas Ramírez 12 July 2018 (has links)
The purpose of this dissertation is to study the Red Supergiant stars (RSGs) in the supermassive young cluster Westerlund 1 through a photometric and spectral analysis. Due to its characteristics, Westerlund 1 is one of the most interesting young massive clusters in the Milky Way and has an impressive population of massive stars, with four RSGs among them. This represents a rare oportunity to study this type of stars in a cluster with well known distance and reddening. Apart from contributing to the general knowledge about RSGs, which parameters are poorly known due to their scarcity, an analysis of these four stars will contribute to solve the puzzle of the formation history of Westerlund 1. For the analysis presented here, photometric data of the four RSGs in Westerlund 1 were used, along with near infrared spectra covering the region from ~8400 Å to ~8900 Å, obtained at two different epochs with the 1.60 m telescope at Observatório do Pico dos Dias (OPD) and the Southern Astrophysical Research Telescope (SOAR). Magnitudes obtained with JHK band photometry were used to calculate effective temperatures and bolometric corrections at the K band through different methods involving the color indices (V-K)_0 and (J-K)_0, in order to determine the luminosities and locate the four RSGs in a Hertzsprung-Russell diagram (HRD). A spectral analysis was performed with the aim of estimating spectral types and the same stellar parameters calculated with the photomety. First, a visual comparison of the depth and strength of the main spectral features (TiO and VO bandheads, and CaT and Fe I lines) was carried out to classify the stars by spectral type. For this purpose, spectra of the four RSGs in the cluster were compared to a group of spectra from well studied reference stars, some of them also RSGs. Then, given their strong dependence on Teff, equivalent widths (EWs) of Fe I lines were measured in all the spectra available. By comparing the EWs measured on spectra of the four RSGs and the reference stars, the Teff\'s of the most similar reference stars were assigned to the RSGs in the cluster. With the Teff\'s obtained through the spectral analysis, new points were added to the initial HRD. The final objective of the present work was to estimate the initial masses and ages of the RSGs in Westerlund 1. This was accomplished by superimposing up to date evolutionary tracks and isochrones to the HRD. Masses and ages were determined for the cases with and without rotation, obtaining an average age for the RSGs of 8 Myr, thus doubling the age of the host cluster determined from the pre-main sequence (PMS). In the final part, it is presented a brief discussion about the discrepancy of the age of Westerlund 1 measured with the PMS isochrones and the age of the RSGs, as well as the uncertainties it raises regarding the formation history of the cluster. / O objetivo desta dissertação é estudar as estrelas Supergigantes Vermelhas (RSGs) no aglomerado jovem supermassivo Westerlund 1 através de uma análise fotométrica e espectral. Devido às suas características, Westerlund 1 é um dos aglomerados jovens mais interessantes da Via Láctea e tem uma população importante de estrelas massivas, com quatro RSGs entre elas. Isso representa uma oportunidade rara para estudar este tipo de estrelas em um aglomerado com a distância e avermelhamento bem conhecidos. Além de contribuir para o conhecimento geral sobre RSGs, cujos parâmetros são pouco conhecidos devido à sua escassez, uma análise dessas quatro estrelas contribuirá para resolver o enigma da história da formação de Westerlund 1. Para a análise apresentada aqui, foram utilizados dados fotométricos das quatro RSGs em Westerlund 1, juntamente com espectros no infravermelho próximo cobrindo a região de ~8400 Å a ~8900 Å, obtidos em duas épocas diferentes com o telescópio de 1.60 m do Observatório do Pico dos Dias (OPD) e o Southern Astrophysical Research Telescope (SOAR). Magnitudes obtidas com a fotometria nos filtros JHK foram usadas para calcular temperaturas efetivas e correções bolométricas na banda K através de diferentes métodos envolvendo os índices de cor (V-K)_0 e (J-K)_0, a fim de determinar as luminosidades e localizar as quatro RSGs em um diagrama de Hertzsprung-Russell (HRD). Uma análise espectral foi realizada com o objetivo de estimar os tipos espectrais e os mesmos parâmetros estelares calculados com a fotometria. Primeiramente, uma comparação visual da profundidade e força das principais características espectrais (as bandas moleculares de TiO e VO e as linhas de CaT e Fe I) foi realizada para classificar as estrelas por tipo espectral. Para este propósito, os espectros das quatro RSGs no aglomerado foram comparados com um grupo de espectros de estrelas de referência bem estudadas, algumas delas também RSGs. Depois, dada a sua forte dependência com a Teff, as larguras equivalentes (EWs) das linhas de Fe I foram medidas em todos os espectros disponíveis. Comparando as EWs medidas nos espectros das quatro RSGs e nos das estrelas de referência, as Teff das estrelas de referência mais similares foram atribuídas às RSGs do aglomerado. Com as Teff obtidas através da análise espectral, novos pontos foram adicionados ao HRD inicial. O objetivo final do presente trabalho foi estimar as massas iniciais e as idades das RSGs em Westerlund 1. Isto foi realizado através da sobreposição no HRD de caminhos evolutivos e de isócronas. Massas e idades foram determinadas para os casos com e sem rotação, obtendo-se uma média de idade para as RSGs de 8 milhões de anos, duplicando assim a idade do aglomerado ao que as RSGs pertencem, e que foi medida através de estrelas de pré-sequência principal (PMS). Na parte final, é apresentada uma breve discussão sobre a discrepância da idade de Westerlund 1 medida com as isócronas da PMS e a idade das RSGs, bem como as incertezas que isso suscita em relação à história da formação do aglomerado.
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Interações estratégicas em games massivos online: visibilidade de simulacros identitários e a axiologia do Transmog em World of WarcraftRazera, Bruno Ayres 26 June 2018 (has links)
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Previous issue date: 2018-06-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The research investigates how the game mode Massively Multiplayer Online Role Playing Game (MMORPG), by strategic concomitance, directs the player to operate by the visibility, to build the meaning of their simulacra identity. Concomitance, according to linguistics, is the designation of one or more actions, things or facts that occur simultaneously; coexistence or simultaneity. In this study the strategic concomitance has the coexistence as the relation of a strategist sender with the subject that provides his own tactic in simultaneity, working values in a same logical line. The most popular game of the genre, World of Warcraft (WOW), is taken as an object, as the immersion of its players is sanctioned by its great geographic reach and number of users who remain, year after year, faithful to the product, generating a movement large volume financial instrument, as well as employing new electronic technology tools and practices. The act of playing keeps the subject in interaction with other subjects and in the operation of this visibility that they construct identity simulations, shaped by the enunciative choices to make-see. In the analysis of the game, the use of the device called "transmog" was used to transform the appearance of the player's equipment. Syntagmatic operations call the device in its placement in discourse and thus build the axiology that makes the subject have to be, a simulacrum of socialized doing that establishes visibility as its main value. The theoretical-methodological support for the analysis is given by the discursive semiotic theory of Greimas (2014, 2007, 2002), which structures the generative path of meaning, the basis of the construction of meaning. It is also supported by Landowski's (1992, 1997, 2013, 2014a, 2014b) socio-demographic concept that, through the regimes of meaning and interaction, as well as through the regimes of visibility, allows to elucidate lived practices of the participants and their simulacrums built in the game. The theories of other semioticians are also bases for the elaboration of the axiological taxonomy of transmog. The bibliographical references also include a review of the history of the games and the survey of works with this theme. To carry out the study, there are analyzes of the transmog phenomenon, highlighting the dynamics of the interactions of the audience of World of Warcraft; in short, the study of the discursive practices of this device in the game, surrounded by the regimes of visibility, meaning and interaction. It was possible, with this, to verify the hypothesis that the visibility values in the game allow to maintain and extend the immersion of the players in a continuity, corresponding to the social practices: transmog, this device in game, does not determine the values in game, as facilitator and computer of an axiological exchange shared to the player. In addition, this work contributed to the theoretical basis for the area of communication that deals with the strategies of the gaming industry / A pesquisa investiga como a modalidade de game Massively Multiplayer Online Role Playing Game (MMORPG), por concomitância estratégica, direciona o jogador a operar pela visibilidade, para a construção do sentido de seus simulacros identitários. Concomitância, de acordo com a linguística, é a designação de uma ou mais ações, coisas ou fatos que ocorrem em simultâneo; coexistência ou simultaneidade. Neste estudo a concomitância estratégica tem como coexistência a relação de um destinador estrategista com o sujeito que provê própria tática em simultaneidade, trabalhando valores em uma mesma linha lógica. O game World of Warcraft (WOW), mais popular do gênero, é tomado como objeto, pois a imersão de seus jogadores é sancionada por seu grande alcance geográfico e número de usuários que permanecem, ano após ano, fiéis ao produto, gerando uma movimentação financeira de grande volume, além de empregar instrumentos e práticas novas de tecnologias eletrônicas. O ato de jogar coloca o sujeito em interação com outros sujeitos e é na operação dessa visibilidade que são construídos simulacros identitários, moldados pelas escolhas enunciativas para fazer-ver. Recortou-se, na análise do game, o uso do dispositivo denominado como “transmog”, que consiste em permitir transformar esteticamente a aparência dos equipamentos do jogador. As operações sintagmáticas convocam o dispositivo na sua colocação em discurso e assim constroem a axiologia que faz o sujeito ter para ser, simulacro do fazer socializado que instaura a visibilidade como seu principal valor. O suporte teórico-metodológico para a análise é dado pela teoria semiótica discursiva de Greimas (2014; 2007; 2002), que estrutura o percurso gerativo de sentido, a base da construção da significação. Apoia-se também na sociossemiótica de Landowski (1992; 1997; 2013; 2014a; 2014b) que, pelos regimes de sentido e de interação, assim como pelos regimes de visibilidade, permite elucidar práticas vividas dos partícipes e do seu fazer em sociedade, pelos simulacros construídos no game. As teorias de outros semioticistas são também bases para a elaboração da taxonomia axiológica do transmog. Os referenciais bibliográficos incluem ainda uma revisão da história dos games e do levantamento de trabalhos com esta temática. Para realizar o estudo, há análises do fenômeno do transmog, destacando a dinâmica das interações do público de World of Warcraft; em minudência, a do estudo das práticas discursivas desse dispositivo no game, nos envoltos dos regimes de visibilidade, de sentido e de interação. Foi possível, com isso, verificar a hipótese de que os valores de visibilidade no game possibilitam manter e ampliar a imersão dos jogadores em uma continuidade, correspondente às práticas sociais: o transmog, este dispositivo in game, não determina os valores em jogo, funcionando como facilitador e ordenador de um câmbio axiológico partilhado ao jogador. Além disso, este trabalho contribuiu para o embasamento teórico para a área da comunicação que trata das estratégias da indústria dos games
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Influência da formação estelar versus buracos negros de nucleos ativos de galaxias (AGN) na evolução de ventos galácticos / Star Formation versus Active Galactic Nuclei (AGN) Black Hole feedback in the Evolution of Galaxy OutflowsBohórquez, William Eduardo Clavijo 10 August 2018 (has links)
Ventos (em inglês outflows) de ampla abertura e larga escala sâo uma característica comum em galáxias ativas, como as galáxias Seyfert. Em sistemas como este, onde buracos negros supermassivos (em inglês super massive black holes, SMBHs) de núcleos galácticos ativos de galáxias (em inglês active galactic nuclei, AGN) coexistem com regiões de formação estelar (em inglês star forming, SF), nâo está claro das observações se o AGN SMBH ou o SF (ou ambos) são responsaveis pela indução desses ventos. Neste trabalho, estudamos como ambos podem influenciar a evolução da galáxia hospedeira e seus outflows, considerando galáxias tipo Seyfert nas escalas de kilo-parsec (kpc). Para este objetivo, estendemos o trabalho anterior desenvolvido por Melioli & de Gouveia Dal Pino (2015), que considerou ventos puramente hidrodinâmicos impulsionados tanto pela SF quanto pelo AGN, mas levando em conta para este último apenas ventos bem estreitos (colimados). A fim de obter uma melhor compreensão da influencia (feedback) desses mecanismos sobre a evolução da galáxia e seus outflows, incluímos também os efeitos de ventos de AGN com maior ângulo de abertura, já que ventos em forma de cone podem melhorar a interação com o meio interestelar da galáxia e assim, empurrar mais gás nos outflows. Além disso, incluímos também os efeitos dos campos magnéticos no vento, já que estes podem, potencialmente, ajudar a preservar as estruturas e acelerar os outflows. Realizamos simulações tridimensionais magneto-hidrodinâmicas (MHD) considerando o resfriamento radiativo em equilíbrio de ionização e os efeitos dos ventos do AGN com dois diferentes ângulos de abertura (0º e 10º) e razões entre a pressão térmica e a pressão magnética beta=infinito, = 300 e 30, correspondentes a campos magnéticos 0, 0,76 micro-Gauss e 2,4 micro-Gauss respectivamente. Os resultados de nossas simulações mostram que os ventos impulsionados pelos produtos de SF (isto é, pelas explosões de supernovas, SNe) podem direcionar ventos com velocidades 100-1000 km s¹, taxas de perda de massa da ordem de 50 Massas solares/ano, densidades de ~1-10 cm-3 e temperaturas entre 10 e 10 K, que se assemelham às propriedades dos denominados absorvedores de calor (em inglês warm absorbers, WAs) e também são compatíveis com as velocidades dos outflows moleculares observadas. No entanto, as densidades obtidas nas simulações são muito pequenas e as temperaturas são muito grandes para explicar os valores observados nos outflows moleculares (que têm n ~150-300 cm³ e T<1000 K). Ventos colimados de AGN (sem a presença de ventos SF) também são incapazes de conduzir outflows, mas podem acelerar estruturas a velocidades muito altas, da ordem de ~10.000 km s¹ e temperaturas T> 10 K, tal como observado em ventos ultra rapidos (em inglês, ultra-fast outflows, UFOs). A introdução do vento de AGN, particularmente com um grande ângulo de abertura, causa a formação de estruturas semelhantes a fontes galácticas. Isso faz com que parte do gás em expansão (que está sendo empurrado pelo vento de SF) retorne para a galáxia, produzindo um feedback \'positivo\' na evolução da galáxia hospedeira. Descobrimos que esses efeitos são mais pronunciados na presença de campos magnéticos, devido à ação de forças magnéticas extras pelo vento AGN, o qual intensifica o efeito de retorno do gás (fallback), e ao mesmo tempo reduz a taxa de perda de massa nos outflows por fatores de até 10. Além disso, a presença de um vento de AGN colimado (0º) causa uma remoção significativa da massa do núcleo da galáxia em poucos 100.000 anos, mas este é logo reabastecido pelo de gás acretante proveniente do meio interestelar (ISM) à medida que as explosões de SNe se sucedem. Por outro lado, um vento de AGN com um grande ângulo de abertura, em presença de campos magnéticos, remove o gás nuclear inteiramente em alguns 100.000 anos e não permite o reabastecimento posterior pelo ISM. Portanto, extingue a acreção de combustível e de massa no SMBH. Isso indica que o ciclo de trabalho desses outflows é de cerca de alguns 100.000 anos, compatível com as escalas de tempo inferidas para os UFOs e outflows moleculares observados. Em resumo, os modelos que incluem ventos de AGN com um ângulo de abertura maior e campos magnéticos, levam a velocidades médias muito maiores que os modelos sem vento de AGN, e também permitem que mais gás seja acelerado para velocidades máximas em torno de ~10 km s¹, com densidades e temperaturas compatíveis com aquelas observadas em UFOs. No entanto, as estruturas com velocidades intermediárias de vários ~100 km s¹ e densidades até uns poucos 100 cm³, que de fato poderiam reproduzir os outflows moleculares observados, têm temperaturas que são muito grandes para explicar as características observadas nos outflows moleculares, que tem temperaturas T< 1000 K. Além disso, estes ventos de AGN não colimados em presença de campos magnéticos entre T< 1000 K. Alem disso, estes grandes ventos AGN de angulo de abertura em fluxos magnetizados reduzem as taxas de perda de massa dos outflows para valores menores que aqueles observados tanto em outflows moleculares quanto em UFOs. Em trabalhos futuros, pretendemos estender o espaço paramétrico aqui investigado e também incluir novos ingredientes em nossos modelos, como o resfriamento radioativo fora do equilíbrio, a fim de tentar reproduzir as características acima que não foram explicadas pelo modelo atual. / Large-scale broad outflows are a common feature in active galaxies, like Seyfert galaxies. In systems like this, where supermassive black hole (SMBH) active galactic nuclei (AGN) coexist with star-forming (SF) regions it is unclear from the observations if the SMBH AGN or the SF (or both) are driving these outflows. In this work, we have studied how both may influence the evolution of the host galaxy and its outflows, considering Seyfert-like galaxies at kilo-parsec (kpc) scales. For this aim, we have extended previous work developed by Melioli & de Gouveia Dal Pino (2015), who considered purely hydrodynamical outflows driven by both SF and AGN, but considering for the latter only very narrow (collimated) winds. In order to achieve a better understanding of the feedback of these mechanisms on the galaxy evolution and its outflows, here we have included the effects of AGN winds with a larger opening angle too, since conic-shaped winds can improve the interaction with the interstellar medium of the galaxy and thus push more gas into the outflows. Besides, we have also included the effects of magnetic fields in the flow, since these can potentially help to preserve the structures and speed up the outflows. We have performed three-dimensional magneto-hydrodynamical (MHD) simulations considering equilibrium radiative cooling and the effects of AGN-winds with two different opening angles (0º and 10º), and thermal pressure to magnetic pressure ratios of beta=infinite, 300 and 30 corresponding to magnetic fields 0, 0.76 micro-Gauss and 2.4 micro-Gauss, respectively. The results of our simulations show that the winds driven by the products of SF (i.e., by explosions of supernovae, SNe) alone can drive outflows with velocities ~100-1000 km s¹, mass outflow rates of the order of 50 Solar Masses yr¹, densities of ~1-10 cm³, and temperatures between 10 and 10 K, which resemble the properties of warm absorbers (WAs) and are also compatible with the velocities of the observed molecular outflows. However, the obtained densities from the simulations are too small and the temperatures too large to explain the observed values in molecular outflows (which have n ~ 150-300 cm³ and T<1000 K). Collimated AGN winds alone (without the presence of SF-winds) are also unable to drive hese outflows, but they can accelerate structures to very high speeds, of the order of ~ 10.000 km s¹, and temperatures T> 10 K as observed in ultra-fast outflows (UFOs). The introduction of an AGN wind, particularly with a large opening angle, causes the formation of fountain-like structures. This makes part of the expanding gas (pushed by the SF-wind) to fallback into the galaxy producing a \'positive\' feedback on the host galaxy evolution. We have found that these effects are more pronounced in presence of magnetic fields, due to the action of extra magnetic forces by the AGN wind producing enhanced fallback that reduces the mass loss rate in the outflows by factors up to 10. Furthermore, the presence of a collimated AGN wind (0º) causes a significant removal of mass from the core region in a few 100.000 yr, but this is soon replenished by gas inflow from the interstellar medium (ISM) when the SNe explosions fully develop. On the other hand, an AGN wind with a large opening angle in presence of magnetic fields is able to remove the nuclear gas entirely within a few 100.000 yr and does not allow for later replenishment. Therefore, it quenches the fueling and mass accretion onto the SMBH. This indicates that the duty cycle of these outflows is around a few 100.000 yr, compatible with the time-scales inferred for the observed UFOs and molecular outflows. In summary, models that include AGN winds with a larger opening angle and magnetic fields, lead to to be accelerated to maximum velocities around 10 km s¹ (than models with collimated AGN winds), with densities and temperatures which are compatible with those observed in UFOs. However, the structures with intermediate velocities of several ~100 km s¹ and densities up to a few 100 cm3, that in fact could reproduce the observed molecular outflows, have temperatures which are too large to explain the observed molecular features, which have temperatures T<1000 K. Besides, these large opening angle AGN winds in magnetized flows reduce the mass loss rates of the outflows to values smaller than those observed both in molecular outflows and UFOs. In future work, we intend to extend the parametric space here investigated and also include new ingredients in our models, such as non-equilibrium radiative cooling, in order to try to reproduce the features above that were not explained by the current model.
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