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The observed bispectrum for SKA and other galaxy surveysJolicoeur, Sheean January 2019 (has links)
Philosophiae Doctor - PhD / Next-generation galaxy surveys will usher in a new era of high precision cosmology.
They will increasingly rely on the galaxy bispectrum to provide improved constraints
on the key parameters of a cosmological model to percent level or even beyond. Hereby,
it is imperative to understand the theory of the galaxy bispectrum to at least the same
level of precision. By this, we mean to include all the general relativistic projection
effects arising from observing on the past lightcone, which still remains a theoretical
challenge. This is because unlike the galaxy power spectrum, the galaxy bispectrum
requires these lightcone corrections at second-order. For the rst time, this PhD project
looks at all the local relativistic lightcone e ects in the galaxy bispectrum for a
at
Friedmann-Lemaitre-Robertson-Walker Universe, giving full details on the second-order
scalars, vectors and tensors. These lightcone effects are mostly Doppler and gravitational
potential contributions. The vector and tensor modes are induced at second order by
scalars. We focus on the squeezed shapes for the monopole of the galaxy bispectrum
because non-Gaussianity of the local form shows high signatures for these triangular
con gurations. In the exact squeezed limit, the contributions from the vectors and
tensors vanish. These relativistic projection effects, if not included in the analysis of
observations, can be mistaken for primordial non-Gaussianity. For future surveys which
will probe equality scales and beyond, all the relativistic corrections will need to be
considered for an accurate measurement of primordial non-Gaussianity.
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Cosmology with next generation radio telescopesWitzemann, Amadeus January 2019 (has links)
Philosophiae Doctor - PhD / The next generation of radio telescopes will revolutionize cosmology by
providing large three-dimensional surveys of the universe. This work presents
forecasts using the technique 21cm intensity mapping (IM) combined with
results from the cosmic microwave background, or mock data of galaxy
surveys. First, we discuss prospects of constraining curvature independently
of the dark energy (DE) model, finding that the radio instrument HIRAX
will reach percent-level accuracy even when an arbitrary DE equation of state
is assumed. This is followed by a study of the potential of the multi-tracer
technique to surpass the cosmic variance limit, a crucial method to probe
primordial non-Gaussianity and large scale general relativistic e↵ects. Using
full sky simulations for the Square Kilometre Array phase 1 (SKA 1 MID)
and the Large Synoptic Survey Telescope (LSST), including foregrounds, we
demonstrate that the cosmic variance contaminated scenario can be beaten
even in the noise free case. Finally, we derive the signal to noise ratio for the
cosmic magnification signal from foreground HI intensity maps combined
with background galaxy count maps. Instruments like SKA1 MID and
HIRAX are highly complementary and well suited for this measurement.
Thanks to the powerful design of the planned radio instruments, all results
confirm their potential and promise an exciting future for cosmology.
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Detecting Baryon Acoustic Oscillations with HI Intensity Mapping using MeerKATEngelbrecht, Brandon January 2019 (has links)
>Magister Scientiae - MSc / Future radio surveys as the Square Kilometer Array (SKA) and its precursor, the "Meer"
Karoo Array Telescope (MeerKAT), will map the Neutral Hydrogen (HI) in large areas of
the sky using the intensity mapping (IM). HI IM is currently one of the most promising ways
of accessing the Large-Scale Structure of the Universe. The distribution of matter in the
Universe not only encodes its composition but also how it evolves and its initial conditions.
An effect on the matter distribution that will be detected by the SKA on the post re-ionization
Universe are the Baryonic Acoustic Oscillations (BAO). While it has been shown that in
single dish mode the SKA can measure the BAO peak in the radial 21cm power spectrum
at low redshifts, this possibility has not yet been studied in detail for the MeerKAT. In this
thesis we construct a set of full sky simulations to test how well MeerKAT will be able
to extract the BAO wiggles along the line of sight. These simulations are done for the
frequencies corresponding to MeerKAT L-band. The maps combine the cosmological HI
signal, systematic noise, cosmological foregrounds and the instrumental telescope beam. A
model-independent estimator is used to extract the BAO wiggles by subtracting a smooth
polynomial component from the 21cm radial power spectrum. We test with simulations
if this estimator is biased and the signal to noise of the extraction. We conclude that we
are able to remove contaminants and recover the cosmological HI signal while not risking
the recovery of the BAO signal. We investigate the effects of varying the sky area and the
observational hours on the signal to noise ratio for the BAO wiggles. We found that for a
HI IM experiment using MeerKAT, the optimal sky area to detect the BAO along the line of
sight is 50% of the sky. With a signal-to-noise ratio of 3.37. This can be achieved with 2000
hours of exposure time
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Risk Management ProjectYan, Lu 02 May 2012 (has links)
In order to evaluate and manage portfolio risk, we separated this project into three sections. In the first section we constructed a portfolio with 15 different stocks and six options with different strategies. The portfolio was implemented in Interactive Brokers and rebalanced weekly through five holding periods. In the second section we modeled the loss distribution of the whole portfolio with normal and student-t distributions, we computed the Value-at-Risk and expected shortfall in detail for the portfolio loss in each holding week, and then we evaluated differences between the normal and student-t distributions. In the third section we applied the ARMA(1,1)-GARCH(1,1) model to simulate our assets and compared the polynomial tails with Gaussian and t-distribution innovations.
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Risk Management ProjectShen, Chen 02 May 2012 (has links)
In order to evaluate and manage portfolio risk, we separated this project into three sections. In the first section we constructed a portfolio with 15 different stocks and six options with different strategies. The portfolio was implemented in Interactive Brokers and rebalanced weekly through five holding periods. In the second section we modeled the loss distribution of the whole portfolio with normal and student-t distributions, we computed the Value-at-Risk and expected shortfall in detail for the portfolio loss in each holding week, and then we evaluated differences between the normal and student-t distributions. In the third section we applied the ARMA(1,1)-GARCH(1,1) model to simulate our assets and compared the polynomial tails with Gaussian and t-distribution innovations.
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[en] RECONSTRUTION OF GEOMETRY BASED IN CONNECTIVITY AND MESH SAMPLES / [pt] RECONSTRUÇÃO DE GEOMETRIA A PARTIR DA CONECTIVIDADE DA MALHA E DE PONTOS DE CONTROLECATIUSCIA ALBUQUERQUE BENEVENTE BORGES 31 August 2007 (has links)
[pt] Este trabalho busca reconstruir a geometria de uma malha
partindo de sua conectividade e de um conjunto esparso de
pontos com geometria conhecida, denominados pontos de
controle. O problema é formulado como a maximização da
suavidade da superfície fixando a posição dos pontos de
controle. Nessa formulação, o método consiste em resolver
um sistema linear esparso aplicando-se mínimos quadrados.
Diferentes propostas para a seleção de pontos de controle,
o método de minimização e a construção do sistema linear
são apresentadas e comparadas. / [en] This work aims at reconstructing the geometry of a mesh
from its connectivity and a small set of control points,
whose geometry is known.The problem
is formulated as a maximization of the surface smoothness
restricting the
position of the control points. With this formulation, the
method reduces
to solving a sparse linear system using least squares
minimization. Several
proposals for the selection of the control points, the
minimization method
and the linear system construction are presented and
compared .
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A PRIVATIZAÇÃO DOS ESPAÇOS PÚBLICOS EM GOIÂNIA: O CASO DAS PRAÇAS.Nascimento, Cristiane Roldan de Carvalho 11 August 2015 (has links)
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Previous issue date: 2015-08-11 / The privatization of public goods can have multiple understandings. However does
the most punctual is the passage of good public right to an essentially private good.
Regarding the public squares, this phenomenon occurs both in the light of Law,
where the state by virtue of their prerogatives donates the squares, and illegally,
though, if studied with the government contribution. Thus, this work aims at the
comprehension of public spaces privatization process nowadays. In this context, our
research was conducted in three places in the city of Goiania, in an attempt to reveal
the mechanisms used by the State in the transformation of a good common use in
private equity. Therefore, this work is based on the study of public space for the
production of capital. The pretext of urban development, public squares are being
decimated. Now fractionated, now suppressed, now privatized. In Goiania, a number
of squares that privatized. The public squares are usually located in the central points
of the neighborhoods, being object of fierce local real estate speculation, clearly
demonstrating the lack of state control over public spaces in Goiania, and also
revealing the inapplicability of the Master Plan, regarding the urban planning. A
phenomenon seen in 1950, when the state (before solely responsible for urban
installment) gave local business pressures. Given this situation, it is increasing in the
city, new ways of living and leisure, such as shopping centers, residential and others.
Thus, the lack of patrons in public areas, can compromise severely the existence of
the squares and the privatization of squares is by far concern because it disrupts
social relations, with the quality of life of a group, and transforms public spaces in
goods. / A privatização dos bens públicos pode ter vários entendimentos. Contundo, o mais
pontual é a passagem do bem de direito público para um bem essencialmente
privado. No que tange as praças públicas, esse fenômeno ocorre tanto à luz da Lei,
onde o Estado por força de suas prerrogativas faz doação das praças, como
ilegalmente, porém, no caso estudado com o aporte do governo. Desse modo, este
trabalho tem por objetivo a compreenção do processo de privatização dos espaços
públicos na contemporaneidade. Dentro desse contexto, nossa pesquisa foi
realizada em três praças na cidade de Goiânia, na tentativa de revelar quais os
mecanismos utilizados pelo Estado na transformação de um bem de uso comum do
povo em patrimônio privado. Assim sendo, este trabalho baseia-se no estudo do
espaço público pela produção do capital. Ao pretexto do desenvolvimento urbano, as
praças públicas estão sendo dizimadas. Ora fracionadas, ora suprimidas, ora
privatizadas. Em Goiânia, são várias as praças que privatizadas. As praças públicas,
geralmente estão localizadas em pontos centrais dos bairros, sendo objeto da
acirrada especulação imobiliária local, demonstrando claramente a falta de controle
do Estado sobre os espaços públicos em Goiânia, e também, revelando a
inaplicabilidade do Plano Diretor, no que tange o planejamento urbano. Fenômeno
este percebido a partir de 1950, quando o Estado (antes único responsável pelo
parcelamento urbano) cedeu às pressões empresariais locais. Diante desse quadro,
é crescente na cidade, novas formas de viver e lazer, tais como os shoppings
centers, residenciais e outros. Desse modo, a falta de frequentadores nos espaços
públicos, pode comprometer severamente as existência das praças e a privatização
das praças é de longe preocupante, pois rompe com as relações sociais, com a
qualidade de vida de um grupo, bem como transforma os espaços públicos em
mercadorias.
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A PRAÇA MARECHAL FLORIANO PEIXOTO EM PONTA GROSSA – PARANÁ:O PROCESSO DE URBANIZAÇÃO E A CONSTITUIÇÃO DE UM LUGAR DE MEMÓRIAViglus, Vera Marina 06 February 2017 (has links)
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Previous issue date: 2017-02-06 / The research work is based on the assumption that the Marechal Floriano Peixoto Square constitutes a place of memory for the city of Ponta Grossa, in the state of Paraná. Through a qualitative, documentary, exploratory research, we sought to understand how the formation of this urban space occurred, especially in the first three decades of the twentieth century, a time that essential symbologies crystallized making possible to perceive this square within the perspective of the historian French author Pierre Nora regarding the constitution of a place of memory. The consolidation of these symbologies was accompanied by the solidification of a process of urbanization influenced by world order factors due to the process of industrialization, the strengthening of the capitalist system and the process of modernization of the Brazilian cities, with special emphasis on the republican context, resulting in differentiated social practices and urban developments such as the creation of squares, street paving, trading development, industries installation and railways construction. The sources used are part of the collections of the Ponta Grossa House of Memories and the Campos Gerais Museum of the Ponta Grossa State University, constituting itself in photographs, newspapers, municipal posture codes from the years of 1891 and 1914, and commemorative albums from Paraná from 1923 and 1927. The study revealed that it was precisely in the first three decades of the twentieth century that the Square began to add material, symbolic and functional elements that point to an official and institutionalized history. It was also possible to verify, in later periods, the construction of other monuments, as well as the implementation of other elements that have re-appropriated the symbology already crystallized in this space, which makes it possible to show, through the sources listed, that the Square, along its process of urbanization, brings with it crystallization marks of memory that can be perceived by the records of a past lived, therefore the Marechal Floriano Peixoto Square is perceived as a place of memory for the city of Ponta Grossa. / O trabalho de pesquisa parte do pressuposto de que a Praça Marechal Floriano Peixoto constitui-se em um lugar de memória para a cidade de Ponta Grossa, no estado do Paraná. Através de pesquisa qualitativa, documental, de caráter exploratório, buscou-se compreender como se deu a formação deste espaço urbano, especialmente nas três primeiras décadas do século XX, momento em que se cristalizaram simbologias essenciais que possibilitam percebê-lo dentro da perspectiva do historiador francês Pierre Nora no que concerne à constituição de um lugar de memória. À consolidação destas simbologias, aliou-se a solidificação de um processo de urbanização influenciado por fatores de ordem mundial em decorrência do processo de industrialização, do fortalecimento do sistema capitalista e do processo de modernização das cidades no Brasil, com especial ênfase no contexto republicano, resultando em diferenciadas práticas sociais e desdobramentos urbanos como a criação de praças, calçamento de ruas, desenvolvimento do comércio, instalação de indústrias e construção de ferrovias. As fontes utilizadas fazem parte dos acervos da Casa da Memória de Ponta Grossa e do Museu Campos Gerais da Universidade Estadual de Ponta Grossa, constituindo-se em fotografias, jornais, códigos de posturas municipais dos anos de 1891 e 1914 e álbuns comemorativos do Paraná dos anos de 1923 e 1927. O estudo revelou que foram justamente nas três primeiras décadas do século XX que a Praça passou a agregar elementos materiais, simbólicos e funcionais que apontam para uma história oficial e institucionalizada. Foi possível verificar, também, em períodos posteriores, a construção de outros monumentos, bem como a implementação de outros elementos que se reapropriam da simbologia já cristalizada neste espaço, o que permite evidenciar, pelas fontes elencadas, que a Praça, ao longo de seu processo de urbanização, traz marcas de cristalização da memória passíveis de serem percebidas pelos registros de um passado vivido, compreendendo-se, portanto, a Praça Marechal Floriano Peixoto como um lugar de memória para a cidade de Ponta Grossa.
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Hospitalidade pública: o caso da Praça Gustavo Teixeira em São Pedro, SP / Public hospitality: the case of the Gustavo Teixeira Square in São Pedro, SPQuiararia, Clarissa Campos 08 June 2018 (has links)
O presente estudo teve como objetivo identificar e analisar como a hospitalidade pública se manifesta na Praça Gustavo Teixeira, em São Pedro, Estado de São Paulo, a partir das relações estabelecidas entre moradores e turistas, tendo como base as dimensões de acessibilidade, legibilidade e identidade. A metodologia utilizada foi uma combinação de pesquisa bibliográfica e documental, fundamentada em documentos de arquivos públicos, fotografias e mapas da Prefeitura Municipal de São Pedro; relatórios de pesquisa baseados em trabalho de campo de auxiliares. Dentre as técnicas de coleta de dados estão observação sistemática e pesquisa de caráter qualitativo, exploratória e com questões semiestruturadas e abertas, o que permitiu um melhor direcionamento no decorrer da conversa informal. O grupo de entrevistados divide-se em moradores, composto por seis pessoas que possuem envolvimento com o local de pesquisa em todos os momentos da vida; e visitantes, composto por mais seis pessoas que não possuem envolvimento diário com o local. Constatou-se que a maioria dos moradores visita a Praça diariamente; suas falas são repletas de sentimentos pelo local; percebem, nitidamente, uma interação com outros moradores e com turistas; a dimensão da acessibilidade, por meio da localização, da qualidade das vias de acesso, da divulgação das atividades, está presente; a legibilidade, por sua vez, faz-se nítida por possuir área verde, bancos, coreto, tranquilidade de cidade do interior; e, por fim, a identidade é percebida na forma como os anfitriões conversam, nas atividades realizadas teatro, música, literatura, quermesse, museu que leva o nome do poeta. Já o grupo de turistas visita a Praça quase todas as vezes que está na Estância, com exceção de um integrante que a visitou pela primeira vez; são motivados pela natureza e pela segurança característica de cidade pequena ao deixar os filhos brincarem em meio ao espaço verde; notam um acolhimento por parte dos moradores, tanto na Praça quanto no comércio do entorno; a acessibilidade é percebida pelas informações passadas em pontos de informações turísticas, no comércio, na internet, na fácil localização por estar no centro da cidade; a dimensão da legibilidade faz-se presente no espaço verde em meio ao urbano, nas lembranças da infância e no encontro com amigos; já a identidade é percebida no artesanato e na gastronomia do entorno, na relação amigável entre as pessoas / The present study aimed to identify and analyze how public hospitality is manifested in Gustavo Teixeira Square, in São Pedro, State of São Paulo, based on relationships established between residents and tourists, based on the accessibility, readability and identity dimensions. The methodology used was a combination of bibliographical and documentary research, based on public records documents, photographs and maps of the São Pedro City Hall; research reports based on auxiliary field work. Among the techniques of data collection are observation systematic and qualitative, exploratory research with semi structured and open questions, which allowed a better targeting during the informal conversation. The group of interviewees is divided into residents, composed of six people who have involvement with the research site at all times of life; and visitors, composed of another six people who do not have daily involvement with the place. It was verified that the residents visit the Square daily; their lines are full of feelings for the place; they perceive, clearly, an interaction with other residents and tourists; the accessibility dimension, through location, the quality of the access roads, the dissemination of activities, is present; the readability, in turn, is made clear by having green area, benches, gazebo, tranquility of inner city; and, finally, the identity is perceived in the way the hosts talk, in the activities performed - theater, music, literature, kermesse, museum that bears the name of the poet. Already the group of tourists visits the Square every time it is in the Estancia, except for one member who visited it for the first time; are motivated by the nature and safety characteristic of a small town - by letting their children play in the green space; they notice a welcome on the part of the residents, both in the Square and in the commerce of the surroundings; the accessibility is perceived by the information passed in points of tourist information, in the commerce, in the internet, in the easy location for being in the center of the city; the dimension of readability is present in the green space in the middle of the urban, in the memories of childhood and in the encounter with friends; already the identity is perceived in the crafts and in the gastronomy of the surroundings, in the friendly relationship between the people
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Investigação do comportamento eletroquímico do inseticida fipronil e desenvolvimento de metodologia eletroanalítica / Investigation of the electrochemical behavior of the insecticide fipronil and development of electroanalytical methodologyAmaral, Raquel Bonatto do 25 May 2012 (has links)
Essa tese de doutorado apresenta o estudo eletroquímico da oxidação do inseticida fipronil bem como o desenvolvimento de metodologias analíticas para a determinação deste composto em amostras de águas naturais. Os experimentos foram realizados sobre os eletrodos de compósito grafite-poliuretana (GPU) e carbono vítreo modificado com nanotubos de carbono de paredes múltiplas (GC-MWCNTs) utilizando a Voltametria de Onda Quadrada (SWV). A Voltametria Cíclica (CV) foi utilizada para diagnosticar o grau de reversibilidade da reação de oxidação do inseticida assim como a natureza do transporte do material eletroativo para a superfície dos eletrodos. Os resultados dos estudos da oxidação eletroquímica do fipronil utilizando o eletrodo de GPU mostraram que a oxidação do fipronil apresenta um em 0,70 V (vs. EAg/AgCl) e ocorre de forma totalmente irreversível e controlada por adsorção das espécies na superfície do eletrodo. Foram obtidas curvas analíticas para o fipronil no intervalo de 2,0 a 14,0 x 10-5 mol L-1, resultando um limite de detecção (LD) de 139 µg L-1 e Limite de Quantificação (LQ) de 480 µg L-1. Para a oxidação do fipronil no eletrodo GC-MWCNTs os resultados mostraram que a oxidação do fipronil apresenta apenas um pico em 0,50 V (vs. EAg/AgCl) e ocorre de forma totalmente irreversível e controlado por difusão a adsorção das espécies na superfície do eletrodo. Os LD e LQ obtidos foram de 26 µg L-1 e 147 µg L-1, respectivamente. O estudo por eletrólise a potencial controlado revelou que a oxidação do inseticida fipronil envolve a participação de um elétron. A metodologia desenvolvida para ambos os eletrodos foi aplicada em amostras de águas naturais, testes de recuperação foram realizados mostrando eficiência de recuperação 96,0% para o eletrodo de GPU e de 94,6% para o eletrodo de GC-MWCNTs. / In this thesis a study of the electrochemical oxidation of the insecticide fipronil and the development of analytical methodologies for the determination of this compound in natural water samples is presented. The experiments were performed at graphite-polyurethane composite electrodes (GPU) and a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs-GC). The electrodes were caracterized using square wave voltammetry (SWV). Cyclic voltammetry (CV) was used to diagnose the degree of reversibility of the oxidation reaction of the insecticide as well as the nature of the transport of the electroactive material to the surface of the electrodes. The electrochemical oxidation of fipronil studies using the GPU electrode showed that fipronil oxidation presents a peak at 0.70 V (vs. EAg/AgCl) which is totally irreversible and controlled by adsorption of species on the electrode surface. Analytical curves were obtained for fipronil in the range 2.0 to 14 x 10-5 mol L-1, with a detection limit (LD) of 139 µg L-1 and a quantification limit (LQ) of 480 µg L-1. For the oxidation of fipronil in the GC-MWCNTs electrode the results showed that fipronil oxidation presents a peak at 0.50 V (vs. EAg/AgCl) which is totally irreversible and diffusion controlled the adsorption of species on the electrode surface. The LD and LQ were obtained 26 µg L-1 and 147 µg L-1, respectively. The study by controlled potential electrolysis showed that oxidation of the insecticide fipronil involves the participation of one electron. The methodology developed for both electrodes was applied to natural water samples, recovery tests were performed showing recovery efficiency of 96.0% for the GPU electrode and 94.6% for MWCNTs-GC electrode.
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