Title: Modelling the Orion Nebula Cluster Author: Václav Pavlík Department: Astronomical Institute of the Charles University Supervisor: doc. RNDr. Ladislav Šubr, Ph.D. (Astronomical Institute of the Charles University) Abstract: Young star clusters are widely discussed from the point of view of their evolution and structure. In this work we focused our attention on studying a typical representative of these objects - the Orion Nebula Cluster (ONC, M 42) - based on the observational data, including their confrontation with N- body models from Šubr et al. (2012). These numerical models were inspired by the recently proposed evolutionary scenario, according to which the star clusters begin their evolution from very dense initial conditions. From the analysis of the X-ray sources we revealed that the ONC is likely to be rotationally symmetric in the inner area (� 0.7 pc). Further analysis including also optical and IR observational data led us to the conclusion that the ONC is elongated from the North-East to the South-West on large scales (up to 2 pc). We also compared radial profiles of different mass groups of stars and we discovered a possibly inverse mass segregation between stars with masses in the interval (1 ; 5) M⊙ and the stars less massive than 0.5 M⊙ in the range from 0.5 pc to 1.5 pc. This...

This thesis is focused on estimation of general economical situation of the firm Oděvní podnik, a.s. from year 2003 to 2009. The thesis is divided into two main parts. In first part the methodology is defined. Second part evaluates the company through the use of methods, which are defined in first part. The main methods I used are ratio analysis and analysis of absolute indicators. One part of this thesis is focused on application of bankruptcy and creditworthy models. The aim was to find out if this models are able to predict the bad financial situation, in which the company at present is.

Made available in DSpace on 2014-06-11T19:22:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-07Bitstream added on 2014-06-13T19:48:36Z : No. of bitstreams: 1 mannis_gdb_me_ia.pdf: 3194427 bytes, checksum: 2374fc542cb39f88a904a9fe24e7d7ef (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho de mestrado tem como seu principal objetivo demonstrar que a aplicação de diferentes métodos analíticos a uma mesma obra e sua posterior comparação é uma metodologia eficaz para o estudo da linguagem musical, em particular de uma obra específica e que, através deste procedimento, informações de interesse teórico e interpretativo, que vão além da aplicação isolada de cada método, podem ser alcançadas. Para tanto, foi feita a análise de um movimento de grande duração inserido em uma obra extensa, composta pelo austríaco Gustav Mahler (1860-1911): a Sinfonia nº3. Sobre esta obra foram realizadas três análises: formal segundo Schoenberg e Rosen; motívica, segundo Réti; e schenkeriana, segundo Salzer.Os métodos foram comparados entre si, de modo a identificarem-se as convergências e divergências entre eles; com base nas divergências e convergências, foramindicadas possibilidades de leitura da obra. Ao final, estes resultados foram confrontados com gravações realizadas por grandes orquestras, tendo à frente regentes reconhecidos como grandes intérpretes da obra de Mahler, verifinco como foram solucionados os problemas de divergência analítica e observando, ainda, se as convergências podem ser confirmadas em suas interpretações. / The present Master's Degree dissertation seeks to demonstrate that the utilization of different analytical methods to a single opus, and their posterior comparation, in an efficient method for the study of musical language, particularly of an specific opus, and that, through this procedure, information on theoretical and interpretative interest that go beyond the isolated utilization of each method can be reached. Therefore, three analysis of the first movement of Gustav Mahler's 3rd Symphony were made. The three analysis were; formal, according to Schoenberg and Rosen; motivic according to Réti; and schenkerian, according to Salzer. The methods were compared to each other so it would be possible to identify similarities and differences amont them. Then, based on these similarities and differences, possibilities of reading of the work were indicated. In the end, these results were confronted with recording made by great orchestras, conducted by great maestros well-known as great interpreters of Mahler's opus, verifying how the problems of analytical diffrences were resolved and observing as well if the similarities coud be confirmed in their interpretations.

<p>The global impact of the converging dual epidemics of tuberculosis (TB) and human immunodeficiency virus (HIV) is one of the major public health challenges of our time, because in many countries, human immunodeficiency virus (HIV) and mycobacterium tuberculosis (TB) are among the leading causes of morbidity and mortality. It is found that infection with HIV increases the risk of reactivating latent TB infection, and HIV-infected individuals who acquire new TB infections have high rates of disease progression. Research has shown that these two diseases are enormous public health burden, and unfortunately, not much has been done in terms of modeling the dynamics of HIV-TB co-infection at a population level. In this thesis, we study these models and design and analyze robust numerical methods to solve them. To proceed in this direction, first we study the sub-models and then the full model. The first sub-model describes the transmission dynamics of HIV that accounts for behavior change. The impact of HIV educational campaigns is also studied. Further, we explore the effects of behavior change and different responses of individuals to educational campaigns in a situation where individuals may not react immediately to these campaigns. This is done by considering a distributed time delay in the HIV sub-model. This leads to Hopf bifurcations around the endemic equilibria of the model. These bifurcations correspond to the existence of periodic solutions that oscillate around the equilibria at given thresholds. Further, we show how the delay can result in more HIV infections causing more increase in the HIV prevalence. Part of this study is then extended to study a co-infection model of HIV-TB. A thorough bifurcation analysis is carried out for this model. Robust numerical methods are then designed and analyzed for these models.&nbsp / Comparative numerical results are also provided for each model.</p>

University of Macau / Faculty of Science and Technology / Department of Mathematics

Nuclear reactor design requires the calculation of integral core parameters and power and radiation profiles. These physical parameters are obtained by the solution of the linear neutron transport equation over the geometry of the reactor. In order to represent the fine structure of the nuclear core a very small geometrical mesh size should be used, but the computational capacity available these days is still not enough to solve these transport problems in the time range (hours-days) that would make the method useful as a design tool. This problem is traditionally solved by the solution of simple, smaller problems in specific parts of the core and then use a procedure known as homogenization to create average material properties and solve the full problem with a wider mesh size. The iterative multi-level solution procedure is inspired in this multi-stage approach, solving the problem at fuel-pin (cell) level, fuel assembly and nodal levels. The nested geometrical structure of the finite element representation of a reactor can be used to create a set of restriction/prolongation operators to connect the solution in the different levels. The procedure is to iterate between the levels, solving for the error in the coarse level using as source the restricted residual of the solution in the finer level. This way, the complete problem is only solved in the coarsest level and in the other levels only a pair of restriction/interpolation operations and a relaxation is required. In this work, a multigrid solver is developed for the in-moment equation of the spherical harmonics, finite element formulation of the second order transport equation. This solver is implemented as a subroutine in the code EVENT. Numerical tests are provided as a standalone diffusion solver and as part of a block Jacobi transport solver.

The presented work deals with two distinct problems in the field of Mathematical Physics. The first part is dedicated to an 'almost' solution of Villani's conjecture, a known conjecture related to a Statistical Mechanics model invented by Kac in 1956, giving a rigorous explanation of some simple cases of the Boltzmann equation. In 2003 Villani conjectured that the time it will take the system of particles in Kac's model to equilibrate is proportional to the number of particles in the system. Our main result in this part is a proof, up to an epsilon, of that conjecture, showing that for all practical purposes we can consider it to be true. The second part of the presentation is based on a joint work with Prof. Michael Loss and is dedicated to a newly developed trace inequality for the fractional Laplacian, connecting between the fractional Laplacian of a function and its restriction to intersection of hyperplanes. The newly found inequality is sharp and the functions that attain equality in it are completely classified.

<p>The global impact of the converging dual epidemics of tuberculosis (TB) and human immunodeficiency virus (HIV) is one of the major public health challenges of our time, because in many countries, human immunodeficiency virus (HIV) and mycobacterium tuberculosis (TB) are among the leading causes of morbidity and mortality. It is found that infection with HIV increases the risk of reactivating latent TB infection, and HIV-infected individuals who acquire new TB infections have high rates of disease progression. Research has shown that these two diseases are enormous public health burden, and unfortunately, not much has been done in terms of modeling the dynamics of HIV-TB co-infection at a population level. In this thesis, we study these models and design and analyze robust numerical methods to solve them. To proceed in this direction, first we study the sub-models and then the full model. The first sub-model describes the transmission dynamics of HIV that accounts for behavior change. The impact of HIV educational campaigns is also studied. Further, we explore the effects of behavior change and different responses of individuals to educational campaigns in a situation where individuals may not react immediately to these campaigns. This is done by considering a distributed time delay in the HIV sub-model. This leads to Hopf bifurcations around the endemic equilibria of the model. These bifurcations correspond to the existence of periodic solutions that oscillate around the equilibria at given thresholds. Further, we show how the delay can result in more HIV infections causing more increase in the HIV prevalence. Part of this study is then extended to study a co-infection model of HIV-TB. A thorough bifurcation analysis is carried out for this model. Robust numerical methods are then designed and analyzed for these models.&nbsp / Comparative numerical results are also provided for each model.</p>

The thesis investigates the concepts of archaeological spatial association within the context of both site and regional data sets. The techniques of geophysical surveying, surface distribution collection and aerial photography are described and discussed. Several new developments of technique are presented as well as a detailed discussion of the problems of data presentation and analysis. The quantitative relationships between these data sets are explored by modelling them as operands and describing association in terms of operators. Both local and global measures of association are considered with a discussion as to their relative merits. Methods for the spatial association of regional lattice and point processes are developed. A detailed discussion of distance based spatial analysis techniques is presented.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais / Analyses of soils and plants, essential for crop fertilization management, are based on methodologies that are time and reagent consuming. Near infrared spectroscopy (NIR - Near-infrared) has proven as a faster and cleaner alternative for simultaneous quantification of compounds. This study evaluates the methodologies based on NIR combined with multivariate calibration methods to estimate levels of silicon (Si), organic matter (O.M.) and clay in soils, and total nitrogen (N-Total) in maize and soybean leaves. Calibration of models for soil analysis was done with 170 soil samples while that for leaf analysis used 109 (58 maize and 51 soybean), obtaining their spectra in a near infrared spectroscopy NIR model 900PLS belonging to the Laboratory Fertilizers, Federal University of Uberlandia (Lafer), Uberlândia-MG, where the models were built. The mathematical method used was the partial least squares: PLS. The model validation has been crossed and the number of latent variables ranged between 5 and 8. The reference methods for comparison were: colorimetric-extraction with calcium chloride (0,01 mol L-1) for analysis of soluble Si in the soil, Walkley-Black Colorimetric analysis of O.M. and the pipette method for clay analysis. The models for determination of N-Total were compared to the Semimicro-Kjeldahl method. After calibration and cross validation, the models were tested and the results evaluated using the correlation coefficient (r), the calibration (RMSEC) and the prediction errors (RMSEP), and relative error (ER). Also, Student s t test at 0,05 significance was used to test for equality between averages. Correlations of 0,71, 0,84 and 0,85 were obtained in the calibration of models for analysis of Si content in the soil, O.M. and clay, respectively. The prediction from these models showed low correlations (lower than 0,5) with significant t test for silicon and clay. The RMSEC obtained from Si analysis was 2,03, RMSEP of 5,74 and ER of 59,2%. To O.M. the RMSEC was 0,81, RMSEP = 1,03 and ER = 39,3%. The analysis of clay presented RMSEC = 11,2, RMSEP = 16,55 and ER = 34,7%. In the analysis of maize and soybean leaf nitrogen calibration correlations of 0,85 and 0,88 were obtained, respectively. Good correlations were obtained for prediction of maize (r = 0,80) and soybean (0,76) samples, with non significant t-test, indicating that leaf analysis for the values predicted by the models NIR/PLS did not differ from those of the reference methods. Calibration and prediction errors for N in maize and soybean were smaller than 5,0 g kg-1, and the ER for N analysis in maize (8,3%) greater than that of soybean (5,7%). The observed results demonstrate greater efficiency in the use of near infrared analysis for leaf than for soil analysis. / As análises de solos e plantas, essenciais no manejo da adubação das culturas, estão baseadas em metodologias que consomem tempo e reagentes. A espectroscopia de infravermelho próximo (NIR Near-infrared) tem se mostrado uma alternativa mais rápida e limpa para quantificação simultânea de compostos. Objetivou-se nesse trabalho avaliar as metodologias baseadas na região NIR, aliada a métodos de calibração multivariada para estimar teores de silício (Si), matéria orgânica (M.O.) e argila em solos e, nitrogênio total (N-Total) em folhas de milho e soja. Para isto, 170 amostras de solos foram utilizadas para a calibração de modelos de análises de solos e 109 amostras de folhas (58 de milho e 51 de soja), sendo seus espectros obtidos em um espectrofotômetro de infravermelho próximo modelo NIR 900PLS pertencente ao Laboratório de Fertilizantes da Universidade Federal de Uberlândia (LAFER), em Uberlândia-MG, onde os modelos foram construídos. O método matemático utilizado foi o de mínimos quadrados parciais: PLS (Parcial Least Squares). A validação dos modelos foi cruzada e o número de variáveis latentes variaram entre 5 e 8. Os métodos de referência comparados foram: colorimétrico com extração por cloreto de cálcio (0,01 mol L-1) para análise do Si solúvel no solo, Walkley-Black colorimétrico para análise de M.O. e o método da Pipeta para análise da argila. Os modelos para determinação do N-Total foram comparados ao método Semimicro-Kjeldahl. Após a calibração e validação cruzada, foi feita a previsão dos modelos onde os resultados foram avaliados através do coeficiente de correlação (r), pelos erros de calibração (RMSEC) e previsão (RMSEP), e erro relativo percentual (ER), além disso, um teste t de student a 0,05 de significância foi aplicado para testar a igualdade entre as médias. Correlações de 0,71, 0,84 e 0,85 foram obtidas na calibração de modelos para análise do teor de Si no solo, M.O. e argila, respectivamente. A previsão a partir desses modelos apresentou correlações baixas (menores que 0,5) com teste t significativo para silício e argila. O RMSEC obtido na análise de Si foi de 2,03, RMSEP de 5,74 e ER de 59,2%. Para M.O. o RMSEC foi de 0,81, RMSEP=1,03 e ER=39,3%. A análise de argila teve RMSEC=11,2, RMSEP=16,55 e ER=34,7%. Na análise do N foliar em milho e soja, foram obtidas na calibração correlações de 0,85 e 0,88, respectivamente. Na previsão de amostras foram conseguidas boas correlações para milho (r=0,80) e soja (0,76), com teste t não significativo, indicando que para análises foliares os valores previstos pelos modelos NIR-PLS não diferiram dos obtidos pelos métodos de referência. Os erros de calibração e previsão para N em milho e soja foram menores que 5,0 g kg-1, sendo o ER para análise de N em milho (8,3%) maior do que o de soja (5,7%). Os resultados observados demonstram uma maior eficiência no uso do infravermelho próximo NIR-PLS para análises foliares do que para análises de solos. / Mestre em Agronomia