Data can be collected in the form of counts in many situations. In other words, the number of deaths from an accident, the number of days until a machine stops working or the number of annual visitors to a city may all be considered as interesting variables for study. This study is motivated by two facts; first, the vital role of the continuous Weibull distribution in survival analyses and failure time studies. Hence, the discrete Weibull (DW) is introduced analogously to the continuous Weibull distribution, (see, Nakagawa and Osaki (1975) and Kulasekera (1994)). Second, researchers usually focus on modeling count data, which take only non-negative integer values as a function of other variables. Therefore, the DW, introduced by Nakagawa and Osaki (1975), is considered to investigate the relationship between count data and a set of covariates. Particularly, this DW is generalised by allowing one of its parameters to be a function of covariates. Although the Poisson regression can be considered as the most common model for count data, it is constrained by its equi-dispersion (the assumption of equal mean and variance). Thus, the negative binomial (NB) regression has become the most widely used method for count data regression. However, even though the NB can be suitable for the over-dispersion cases, it cannot be considered as the best choice for modeling the under-dispersed data. Hence, it is required to have some models that deal with the problem of under-dispersion, such as the generalized Poisson regression model (Efron (1986) and Famoye (1993)) and COM-Poisson regression (Sellers and Shmueli (2010) and Sáez-Castillo and Conde-Sánchez (2013)). Generally, all of these models can be considered as modifications and developments of Poisson models. However, this thesis develops a model based on a simple distribution with no modification. Thus, if the data are not following the dispersion system of Poisson or NB, the true structure generating this data should be detected. Applying a model that has the ability to handle different dispersions would be of great interest. Thus, in this study, the DW regression model is introduced. Besides the exibility of the DW to model under- and over-dispersion, it is a good model for inhomogeneous and highly skewed data, such as those with excessive zero counts, which are more disperse than Poisson. Although these data can be fitted well using some developed models, namely, the zero-inated and hurdle models, the DW demonstrates a good fit and has less complexity than these modifed models. However, there could be some cases when a special model that separates the probability of zeros from that of the other positive counts must be applied. Then, to cope with the problem of too many observed zeros, two modifications of the DW regression are developed, namely, zero-inated discrete Weibull (ZIDW) and hurdle discrete Weibull (HDW) models. Furthermore, this thesis considers another type of data, where the response count variable is censored from the right, which is observed in many experiments. Applying the standard models for these types of data without considering the censoring may yield misleading results. Thus, the censored discrete Weibull (CDW) model is employed for this case. On the other hand, this thesis introduces the median discrete Weibull (MDW) regression model for investigating the effect of covariates on the count response through the median which are more appropriate for the skewed nature of count data. In other words, the likelihood of the DW model is re-parameterized to explain the effect of the predictors directly on the median. Thus, in comparison with the generalized linear models (GLMs), MDW and GLMs both investigate the relations to a set of covariates via certain location measurements; however, GLMs consider the means, which is not the best way to represent skewed data. These DW regression models are investigated through simulation studies to illustrate their performance. In addition, they are applied to some real data sets and compared with the related count models, mainly Poisson and NB models. Overall, the DW models provide a good fit to the count data as an alternative to the NB models in the over-dispersion case and are much better fitting than the Poisson models. Additionally, contrary to the NB model, the DW can be applied for the under-dispersion case.

Submitted by Luiz Felipe de Melo Santos (felipemelo.biologia@gmail.com) on 2019-01-26T15:00:46Z No. of bitstreams: 1 001-2019-Luiz Felipe de Melo Santos.pdf: 2201809 bytes, checksum: 0858caf6045635fdc1eb50f8be76eb88 (MD5) / Approved for entry into archive by Fabio Sampaio Rosas null (fabio@dracena.unesp.br) on 2019-01-28T12:24:37Z (GMT) No. of bitstreams: 1 Santos_lfm_me_dra.pdf: 2201809 bytes, checksum: 0858caf6045635fdc1eb50f8be76eb88 (MD5) / Made available in DSpace on 2019-01-28T12:24:37Z (GMT). No. of bitstreams: 1 Santos_lfm_me_dra.pdf: 2201809 bytes, checksum: 0858caf6045635fdc1eb50f8be76eb88 (MD5) Previous issue date: 2018-11-27 / O enxofre é, provavelmente, o macronutriente menos empregado nas adubações, o que resulta na redução de rendimento e qualidade de forragem. Entre os nutrientes, apresenta um importante papel por participar em várias funções biológicas, faz parte da composição dos aminoácidos cisteína, metionina e cistina, acetil-CoA, bem como de enzimas que participam da fotossíntese e o metabolismo do nitrogênio. O objetivo foi avaliar a produção e estado nutricional dos capins Piatã e Mombaça em resposta a aplicação de doses e fontes de sulfato e enxofre elementar em Argissolo Vermelho Amarelo. Em virtude disso, realizou-se dois experimentos em casa de vegetação na Faculdade de Ciências Agrárias e Tecnológicas, UNESP, Campus de Dracena – SP, o primeiro foi no período de janeiro a março de 2017 e o segundo de outubro a janeiro de 2018, com o capim Piatã e de Mombaça, respectivamente. O delineamento experimental foi em blocos casualizados com quatro repetições, arranjados em esquema fatorial, 4x5, com quatro fontes de enxofre (Gipsita, Fosfogesso, S elementar em pó e S elementar pastilhado) e cinco doses de enxofre (0, 50, 100, 150 e 200 mg kg-1).Foram determinados os parâmetros biométricos como número de perfilhamento, massa seca da parte aérea (MSPA) e massa seca de raízes (MSR). O estado nutricional das plantas foi avaliado por meio da leitura SPAD e análise de macronutrientes N, P, K, Ca, Mg, S na parte aérea das plantas. Avaliou-se também o enxofre residual do solo e o pH do solo. Os resultados demonstraram que adubação com S aumentou a produção de MSPA, MSR, número de perfilhos, quantidade de folhas por colmo, índice SPAD e promoveu uma melhor qualidade de estado nutricional da forragem em ambos os experimentos. A granulométrica das fontes apresentou uma forte influencia na disponibilização de S, o que é possível de ser constado pelos menores incrementos na produção e absorção de S verificados com o uso da fonte SEPA em relação às demais fontes, tanto na espécie Urochloa brizantha quanto da espécie Megathyrsus maximum. De forma geral a aplicação ideal de S foi essencial para otimizar o rendimento dos capins Piata e Mombaça em todas as fontes testadas de S, enquanto a baixa oferta de S resulta em desequilíbrio nutricional e menor rendimento. / Sulfur is probably the least used macronutrient in fertilization, which results in reduced yield and forage quality. Among nutrients, it plays an important role because it participates in several biological functions, is part of the composition of the amino acids cystine, methionine and cysteine, acetyl-CoA, as well as enzymes involved in photosynthesis and nitrogen metabolism. The objective was to evaluate the production and nutritional status of the Piatã and Mombasa grass in response to the application of doses and sources of sulfate and elemental sulfur in Yellow Red Ultisol. In view of that, two greenhouse experiments were carried out at the Faculty of Agrarian and Technological Sciences, UNESP, Dracena Campus - SP, the first one was in the period from January to March 2017 and the second from October to February 2018, with Piatã grass and Mombasa grass, respectively. The experimental design was in randomized blocks with four replications, arranged in a factorial scheme, 4x5, with four sulfur sources (Fosfogesso, Grajau, S-Elementar and Sulfurgran) and five doses of sulfur (0, 50, 100, 150 e 200 mg kg-1). Biometric parameters such as tillering number, shoot dry mass and roots dry mass were determined. The nutritional status of the plants was evaluated by SPAD reading and analysis of N, P, K, Ca, Mg and S macronutrients in shoot dry mass. Residual sulfur and soil pH were also evaluated. The results showed that S fertilization increased the yield of MSPA, MSR, number of tillers, number of leaves per stem, SPAD index and promoted a better quality of forage nutritional status in both experiments. The granulometric of the sources had a strong influence on the availability of S, which is possible to be consisted of the smaller increases in the production and absorption of S verified with the use of the SEPA source in relation to the other sources, both in the species Urochloa brizantha and of the species Megathyrsus maximum. In general, the ideal application of S was essential to optimize the yield of the Piata and Mombasa grasses in all tested sources of S, while the low supply of S results in nutritional imbalance and lower yield.

by Sin Yu Tsang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (leaves 40-42). / Chapter Chapter 1. --- Introduction --- p.1 / Chapter Chapter 2. --- Two-level structural equation model --- p.5 / Chapter Chapter 3. --- Estimation of the model under general constraints --- p.11 / Chapter Chapter 4. --- Estimation of the model under linear constraints --- p.22 / Chapter Chapter 5. --- Simulation results --- p.27 / Chapter 5.1 --- "Artificial examples for ""modified"" EM algorithm" --- p.27 / Chapter 5.2 --- "Artificial examples for ""restricted"" EM algorithm" --- p.34 / Chapter Chapter 6. --- Discussion and conclusion --- p.38 / References --- p.40 / Tables --- p.43

Introdução: o envelhecimento está associado a perdas cardiorrespiratórias e neuromusculares, que estão relacionadas com quedas, hospitalizações e perda da independência funcional. O treinamento concorrente (TC) já está estabelecido como a melhor ferramenta para combater estes declínios e, portanto, deve-se entender a melhor forma de prescrever este treinamento. Com relação a parte neuromuscular do TC, o uso de repetições máximas (RM) vem sendo questionado sobre sua eficácia e, em idosos, ainda não existem estudos abordando este tema. Objetivo: investigar possíveis diferenças nas adaptações neuromusculares à execução ou não execução de repetições máximas nos exercícios de força, explorando também o uso do volume equalizado (número de repetições igualadas com as repetições máximas), durante o TC em homens idosos. Materiais e métodos: o estudo contou com 12 semanas de TC feito duas vezes na semana; 32 homens idosos foram randomizados para um dos três diferentes grupos: grupo com repetições máximas (GRM); grupo com repetições submáximas (GRNM), que trabalhava com 50% do volume do GRM; e um grupo que trabalhava com volume equalizado (GRNMVE), ou seja, mesmo volume do GRM, porém com ausência de séries chegando até a falha concêntrica. As variáveis analisadas foram o 1RM (kg) no exercício LG e EJ, CIVM dos extensores de joelho direito no dinamômetro isocinético, na qual foram avaliados: PTIso, TPT nos intervalos 0-50, 0100 e 0-250 m.s e EMG (μV) do músculo RF e VL, desempenho de saltos CMJ e SJ, avaliados no tapete de saltos e EM do quadríceps por US. A análise estatística dos dados está apresentada em média e DP. Todas as análises foram feitas no software SPSS 21.0, com nível de significância de  < 0,05 para todas as variáveis. O TE, que foi calculado pela diferença na média pré e pós treinamento da variável dividido pelo DP pré treinamento. Resultados: todos os grupos incrementaram seus valores de base para o período pós treinamento. Para a força máxima, 1RM LG e EJ incrementaram em todos grupos (p < 0,05 e p < 0,001, respectivamente), sem diferenças entre eles (ganhos ~50% e ~30% para LG e EJ, respectivamente). O PTIso teve incrementos, mas não significativos, (p = 0,072; incrementos de 5 – 15%). Para a TPT 0-50m.s (p=0,066) não teve ganhos significativos, porém os intervalos da TPT 0-100 (p=0,027; ganhos ~15%) e TPT 0-250m.s (p<0,05; ganhos~12%) foram significativos para todos os grupos. Para o desempenho de saltos, o CMJ teve uma tendência significativa (p=0,056; ganhos de 3-12%) e o SJ teve incrementos significativos (p<0,05; ganhos ~15%), para todos os grupos, sem diferenças entre os grupos. Para os valores de EMG RF e EMG VL (p>0,05 para ambos), não houve incremento em todos os grupos. Para os valores de EM, todos os grupos aumentaram seus valores, sem diferenças entre os grupos, de modo significativo (p<0,05), com exceção ao VI, que não teve ganhos significativos (VI: p= 0,85), sem diferenças entre os grupos. Para o somatório do quadríceps, todos os grupos incrementaram seus valores significativamente (p<0,05; ganhos de 2-10%), sem diferenças entre os grupos. Para a tensão específica, todos os grupos incrementaram seus valores significativamente (p< 0,001; ganhos de 11-29%), sem diferenças entre eles. Conclusões: o uso de repetições máximas no treino de força (TF), dentro do contexto do TC, em idosos, não é necessário, já que não foi observada vantagem no GRM. Mesmo um menor volume de treinamento foi capaz de induzir a mesma magnitude de adaptações. / Introduction: aging is associated with cardiorespiratory and neuromuscular losses, which are related to falls, hospitalizations, and loss of functional independency. Concurrent training (CT) is already established to be the best form to fight these declines and, therefore, it is necessary to understand the best way to prescribe these type of training. Regarding the neuromuscular part from the CT, the use of repetitions maximum (RM) is being questioned about it’s efficacy and, in elderly, this them has not yet been approached. Objective: investigate the possible differences in the neuromuscular adaptations due to the execution of maximum repetitions in strength training, also exploring the use of equalized volume, during the CT in elderly men. Materials and methods: the study accounted with 12 weeks of CT, done twice a week; 32 male elderly were randomized into one of the three groups: one protocol using RM, referred by the GRM initials; another protocol using 50% of the volume from the GRM, referred by the GRNM initials; and the last protocol using the same volume from the GRM, but with more series to equalize the total volume, without reaching concentric failure, referred by the initials GRNMVE. The analyzed variables were 1RM (kg) for the LG and EJ exercises, MIVC of the knee extensors, in which were computed: PTIso, RFD at the 0-50, 0-100 and 0-250 m.s intervals and the EMG (μV) from RF and VL muscles. Jump’s performance from the CMJ and SJ, at the jump’s carpet, MT done by US. All the data are presented in media and ST. all the analyzes were made in the SPSS software, version 21.0, with the significance level set at  < 0,05 for all variables. The EF was calculated by the difference between the means from pre to post training, divided by the pre training SD. Results: all groups increased their values from baseline to post training. For maximum strength, 1RM LG and EJ increased in all groups (p<0,05 e p<0,001, respectively), without differences between them (gains ~50% and ~30% for LG e EJ, respectively). PTIso increased their values, but without significance (p = 0,072; gains from 5 to 15%). For RFD 0-50 m.s, there were no significative gains (p=0,066), but there significant gains for the intervals RFD 0-100m.s (p=0,027; ganhos ~15%) RFD 0-250 m.s (p<0,05; ganhos~12%) for all groups. For the jump’s performance, the CMJ had a trend towards signifcance (p=0,056; increases from 3 to 12%) and SJ had significant gains (p<0,05; ganhos ~15%), for all grops, with no difference between them.For thw EMG RF e EMG VL values, there was no difference found (p>0,05 for both) in any group. For the MT values, all groups increased their baseline values for all muscles (p<0,05), except for VI, that showed no significative gains (VI: p= 0,85), with no difference between the groups. For the total quadriceps MT, all groups increased their values (p<0,05; gains from 2 to 10%), without any group differences. Fot the MQ quality values, all groups increased their baseline values (p< 0,001; gains from 11 to 29%), with no difference between them. Conclusions: the use of RM on the ST, inside the context of CT, in elderly, is not necessary, because it was not noted an advantage for the GRM. Even a smaller volume of training was able to induce the same magnitude adaptations.

Orientador: Reges Heinrichs / Resumo: O enxofre é, provavelmente, o macronutriente menos empregado nas adubações, o que resulta na redução de rendimento e qualidade de forragem. Entre os nutrientes, apresenta um importante papel por participar em várias funções biológicas, faz parte da composição dos aminoácidos cisteína, metionina e cistina, acetil-CoA, bem como de enzimas que participam da fotossíntese e o metabolismo do nitrogênio. O objetivo foi avaliar a produção e estado nutricional dos capins Piatã e Mombaça em resposta a aplicação de doses e fontes de sulfato e enxofre elementar em Argissolo Vermelho Amarelo. Em virtude disso, realizou-se dois experimentos em casa de vegetação na Faculdade de Ciências Agrárias e Tecnológicas, UNESP, Campus de Dracena – SP, o primeiro foi no período de janeiro a março de 2017 e o segundo de outubro a janeiro de 2018, com o capim Piatã e de Mombaça, respectivamente. O delineamento experimental foi em blocos casualizados com quatro repetições, arranjados em esquema fatorial, 4x5, com quatro fontes de enxofre (Gipsita, Fosfogesso, S elementar em pó e S elementar pastilhado) e cinco doses de enxofre (0, 50, 100, 150 e 200 mg kg-1).Foram determinados os parâmetros biométricos como número de perfilhamento, massa seca da parte aérea (MSPA) e massa seca de raízes (MSR). O estado nutricional das plantas foi avaliado por meio da leitura SPAD e análise de macronutrientes N, P, K, Ca, Mg, S na parte aérea das plantas. Avaliou-se também o enxofre residual do solo e o pH do solo. Os res... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

In order to determine the timing of Antarctic ice sheet retreat and advance during the Late Quaternary, various tools are used to measure the age of marginal marine sediments. Carbonate 14C dating is a well-established approach, but requires foraminiferal microfossils, shells or other carbonate materials that are rare in most Antarctic regions, and may also suffer from vital effects, which can result in variability of up to 500 years in living organisms. Bulk acid insoluble organic (AIO) 14C dates are frequently as an alternative, but this approach works best where high productivity and sedimentation rates reign, and not too well in condensed sequences where high proportions of detritus are present. Compound specific dating methods have also been employed, but these may still yield an average age from a mixture of components and require very large sample sizes. Alternate methods of applying a chronology have also been used, such as magnetic intensity dating, or regional correlation with well-dated cores, but these may not always provide accurate and precise dates. Here I present work, some published with co-authors, of progressive improvements of Ramped PyrOx 14C dating, which utilizes the thermochemical degradation of components within a bulk AIO sediment sample. This dissertation focuses on the study, improvement and application of advanced Ramped PyrOx techniques. These improvements include novel techniques, such as compositing and isotope dilution that I use to date sediments where the proportion of contemporaneously deposited carbon is very small relative to other detrital components, and maximize the accuracy of resulting dates while minimizing costs in precision from utilizing ultra-small fractions of the bulk sample. Ramped PyrOx 14C dating techniques allows us to generate chronologies for cores that would otherwise go undated. Furthermore, these techniques can be used to push the limits of radiocarbon dating not only to regions where accurate core chronologies have been difficult to come by, but also further back in time, into marine sediment horizons deposited at or before the last glacial maximum (LGM), where highly detrital material has precluded radiocarbon dating in the past. Wider use of these techniques can enable more coordinated a priori coring efforts to constrain regional glacial responses to rapid warming.

Abstract not available

Image reconstruction, in common with many other inverse problems, is often mathematically ill-posed in the sense that solutions are neither stable nor unique. Ultrasonic image reconstruction is particularly notorious in this regard, with narrow transducer bandwidths and limited - sometimes sparsely sampled apertures posing formidable difficulties for conventional signal processing. To overcome these difficulties, some form of regularisation is mandatory, whereby the ill-posed problem is restated as a closely related, well-posed problem, and then solved uniquely. This thesis explores the application of maximum entropy (MaxEnt) regularisation to the problem of reconstructing complex-valued imagery from sparsely sampled coherent ultrasonic field data, with particular emphasis on three-dimensional problems in the non-destructive evaluation (NDE) of materials. MaxEnt has not previously been applied to this class of problem, and yet in comparison with many other approaches to image reconstruction, it emerges as the clear leader in terms of resolution and overall image quality. To account for this performance, it is argued that the default image model used with MaxEnt is particularly meaningful in cases of ultrasonic scattering by objects embedded in homogeneous media. To establish physical and mathematical insights into the forward problem, linear equations describing scattering from both penetrable and impenetrable objects are first derived using the Born and physical optics approximations respectively. These equations are then expressed as a shift-invariant computational model that explicitly incorporates sparse sampling. To validate this model, time-domain scattering responses are computed and compared with analytical solutions for a simple canonical test case drawn from the field of NDE. The responses computed via the numerical model are shown to accurately reproduce the analytical responses. To solve inverse scattering problems via MaxEnt, the robust Cambridge algorithm is generalised to the complex domain and extended to handle broadband (multiple-frequency) data. Two versions of the augmented algorithm are then compared with a range of other algorithms, including several linearly regularised algorithms and lastly, due to its acknowledged status as a competitor with MaxEnt in radio-astronomy, the non-linear CLEAN algorithm. These comparisons are made through simulated 3-D imaging experiments under conditions of both complete and sparse aperture sampling with low and high levels of additive Gaussian noise. As required in any investigation of inverse problems, the experimental confirmation of algorithmic performance is emphasised, and two common imaging geometries relevant to NDE are selected for this purpose. In monostatic synthetic aperture imaging experiments involving side-drilled holes in an aluminium plate and test objects immersed in H2O, MaxEnt image reconstruction is demonstrated to be robust against grating-lobe and side-lobe formation, in addition to temporal bandwidth restriction. This enables efficient reconstruction of 2-D and 3-D images from small numbers of discrete samples in the spatial and frequency domains. The thesis concludes with a description of the design and testing of a novel polyvinylidene fluoride (PVDF) bistatic array transducer that offers advantages over conventional point-sampled arrays in terms of construction simplicity and signal-to-noise ratio. This ultra-sparse orthogonal array is the only one of its kind yet demonstrated, and was made possible by MaxEnt signal processing.

Object recognition in the visual cortex is based on a hierarchical architecture, in which specialized brain regions along the ventral pathway extract object features of increasing levels of complexity, accompanied by greater invariance in stimulus size, position, and orientation. Recent theoretical studies postulate a non-linear pooling function, such as the maximum (MAX) operation could be fundamental in achieving such invariance. In this paper, we are concerned with neurally plausible mechanisms that may be involved in realizing the MAX operation. Four canonical circuits are proposed, each based on neural mechanisms that have been previously discussed in the context of cortical processing. Through simulations and mathematical analysis, we examine the relative performance and robustness of these mechanisms. We derive experimentally verifiable predictions for each circuit and discuss their respective physiological considerations.

Die Zuwanderung nach Tirana führte im Verlauf der 1990er Jahre zu einem enormen Flächenverbrauch auf Kosten landwirtschaftlicher Flächen im Umland der albanischen Hauptstadt. Im Rahmen der vorliegenden Arbeit wird die Entwicklung des rasanten Flächenverbrauchs mit computergestützten Methoden dokumentiert. Grundlage der Untersuchung bilden zwei zu unterschiedlichen Zeitpunkten (1988 und 2000) aufgenommene Satellitenszenen, mit Hilfe derer eine Änderungsanalyse durchgeführt wird. Ziel der Änderungsanalyse ist es, den Flächennutzungswandel zu analysieren, Daten zu generieren und die Ergebnisse in geeigneter Weise zu visualisieren. Zu den protagonistischen Verfahren der Änderungsanalyse zählen sowohl die Maximum-Likelihood Klassifikation sowie ein wissensbasierter Klassifizierungsansatz. Die Ergebnisse der Änderungsanalyse werden in Änderungskarten dargestellt und mittels einer GIS-Software statistisch ausgewertet.