The three-parameter lognormal distribution is widely used in many areas of science. Some modifications have been proposed to improve the maximum likelihood estimator. In some cases, however, the modified maximum likelihood estimates do not exist or the procedure encounters multiple estimates. The purpose of this research is focused on estimating the threshold or location parameter , because when is known, then the other two estimated parameters are obtained from the first two MLE equations. In this research, a method for constructing confidence intervals, confidence limits, and point estimator for the threshold parameter is proposed. Monte-Carlo simulation, bisection method, and SAS/IML were used to accomplish this objective. The bias of the point estimator and mean square error (MSE) criteria were used throughout extensive simulation to evaluate the performance of the proposed method. The result shows that the proposed method can provide quite accurate estimates.

Orientador: Fernando Antônio Campos Gomide / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-18T11:42:14Z (GMT). No. of bitstreams: 1 Marques_VitorHugoAlmeida_M.pdf: 2517224 bytes, checksum: e0259e1018ac57ec9a5cb95e0d65284b (MD5) Previous issue date: 2011 / Resumo: Esta dissertação introduz um sistema nebuloso genético (SNG) para adaptação de parâmetros em meta-heurísticas. Duas meta-heurísticas entre as mais usadas foram consideradas como exemplos, algoritmo genético e busca tabu. Os parâmetros trabalhados na busca tabu são relacionados às memórias, de curto prazo e de longo prazo. Já os parâmetros do algoritmo genético a sofrer adaptação são as taxas de reprodução e mutação. Sistemas baseados em regras nebulosas oferecem um mecanismo natural para descrever comportamentos globais como combinação de regras de controle. Eles também herdam um meio de gradualmente alternar entre regras que conjuntamente definem uma estratégia de controle. Dessa forma, esses sistemas são candidatos naturais para construir estratégias de controle de parâmetro porque eles proveem um maneira de desenvolver mecanismos baseados na natureza específica de uma região de busca e as transições entre suas fronteiras. Uma aplicação usando o problema clássico de roteamento de veículos com janela de tempo foi incluído para avaliar o desempenho do sistema nebuloso genético. Resultados experimentais mostram que meta-heurísticas com o mecanismo de adaptação com SNG melhoram o comportamento da busca e a qualidade das soluções quando comparado à versões padrões ( sem SNG ) e com parâmetros constantes dos algoritmos genético e busca tabu. Eles também geram boas soluções sub-ótimas mais rápidas que métodos exatos desenvolvidos para o problema e que são reportados na literatura / Abstract: This dissertation introduces a genetic fuzzy system for parameter adaptation of metaheuristics. Two metaheuristics, among the most used ones, have been considered as examples, genetic algorithm and tabu search. The considered parameters of the tabu search are related to the short and long term memories. Parameters of the genetic algorithm under adaptation are the mutation and reproduction rates. Fuzzy rule-based models offer a natural mechanism to describe global behavior as a combination of control rules. They also inherit a means to gradually shift between control rules which jointly defines a control strategy. They are a natural candidate to construct parameter control strategies because they provide a way to develop decision mechanisms based on the specific nature of search regions and transitions between their boundaries. An application using the classic vehicle routing problem with time windows is included to evaluate the genetic fuzzy system performance. Experimental results show that metaheuristics with GFS improve search behavior and solution quality when compared against standard, constant parameters genetic and tabu search approaches. It also provides reasonably good suboptimal solutions faster than specially tailored exact methods reported in the literature / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

Objective: To compare the translucency of six different porcelains indicated for veneers, with various shades and opacities. Methods: 13mm diameter and 0.7mm thickness discs were fabricated for the following porcelains (A1 shade; n=5): Empress Esthetic (EE), e.maxPress (EP), InLine (IL) (Ivoclar Vivadent); VITA PM9 (VPM), Vitablocks MarkII (VMII) (Vita Zahnfabrik); Kavo Everest G-Blank (KEG) (KaVo Dental GmbH) and Lava Zirconia (LZ) (3M ESPE). IL and LZ respectively served as positive and negative controls. Groups with different shades (BL2, BL4, A1, B1), as well as high (HT) and low translucencies (LT), were fabricated for e.maxPress. The luminous reflectance (Y) and color coordinates (CIE L*a*b*) were measured with a colorimeter (CIE illuminant D65, 2-degree observer function) with the specimens placed on black and white backgrounds. Contrast ratios (CR = YB/YW) and translucency parameters (TP= [(LB* - LW*)2 + (aB* - aW*)2 + (bB* - bW*)2 ]1/2) were calculated. One-way ANOVA and post-hoc Tukey's HSD tests were used to analyze the data (α = 0.05). Results: Statistically significant differences in CR and TP were found among porcelains (P < .0001). The CR means in order of decreasing translucency were: VPM (0.15) > VMII (0.24), IL (0.25), KEG (0.26) > EP HTB1 (0.32), EE (0.34) > EP HTA1 (0.37), EP HTBL4 (0.37) > EP HTBL2 (0.43), EP LTA1 (0.47) > LZ (0.73). The TP means in order of decreasing translucency were: VPM (40.34) > VMII (33.66), KEG (33.52), IL (32.44) > EP HTB1 (27.96), EE (27.64) > EP HTA1 (26.59), EP HTBL4 (26.14) > EP HTBL2 (22.70), EP LTA1 (21.35) > LZ (10.43). Translucency of conventional feldspathic porcelain was comparable to that of machinable feldspathic porcelain. Pressable feldspathic porcelain presented the greatest translucency. Shade and thickness influenced lithium disilicate porcelain translucency. Conclusion: Various ceramics systems designed for porcelain veneers present various degrees of translucency.

MSCAGR (Animal Science) / One of the ways to minimise cost and promote health in humans and animals is to use natural feed additives instead of antibiotics. Moringa oleifera (Moringa) is a phytobiotic which possess anti-microbial and immune-modulatory properties and contains high levels of nutrients and it can be used as a feed additive. Probiotics are feed additives which consist of living microorganisms that have beneficial effects on the physiology and health of other organisms. The objective of the study was to determine the effect of various levels of Moringa oleifera and probiotics inclusion on growth performance, carcass characteristics and cost benefit analysis for broiler chicken production. Moringa oleifera leaf powder was purchased from Bethel Farm No:683 Bethel mission Gucksdadt Vryheid in Zululand district AbaQulusi municipality. The study was a 5x2 factorial design with five levels of Moringa and two levels of probiotic. Six hundred (600) Ross 308-day old chicks were received and fed commercial starter. The experimental treatments were randomly divided into five levels of Moringa with and without probiotics introduced through drinking water at grower to finisher phase. The diets were supplemented with different inclusion levels of Moringa (Mo) as follows: 0g/kg (M0), 0.6g/kg (M3), 1.2g/kg (M6), 1.8g/kg (M9), 2.4g/kg (M12) of Moringa oleifera leaf meal (MOLM) and probiotic at P0 (0ml/bird/week), P1 (1 ml/bird/week) of a commercial probiotic administered in water for the first three weeks (starter phase). The experiment had three replications with 20 birds per replicate. MOLM and PRB interaction had no significant effect (P>0.05) on any of growth parameters and same findings with MOLM. Probiotics treatments had significantly reduced (P < 0.05) mortality rate (MTRT) in the grower phase. MOLM×PRB had significant effect on (P<0.01) feed intake (FI), MOLM had significantly reduced (P< 0.05) average bodyweight gain (ABWG) and FI in finisher phase. MOLM and PRB interaction had significant effect (P< 0.05) on dressed weight only and non-significant effect (P>0.05) on the rest of carcass parameters. MOLM inclusion levels did not significantly affect (P>0.05) back fat weight. However, MOLM inclusion level significantly reduced (P< 0.05) dressed weight, shank length, wing weight, drum and thigh weight, back weight and breast muscle weight. PRB inclusion in the diets significantly increased (P< 0.01) shank size and drum + thigh weights (P<0.05). MOLM and PRB inclusion level had no significant effect (P>0.05) on giblets parameters. MOLM and PRB interaction had significant effect on (P<0.05) water holding capacity (WHC) and hardness. MOLM had significant effect (P<0.05) on pH and dripping loss. A significant effect between (MOLM×PRB) Moringa oleifera leaf meal and probiotics (P<0.01) was observed on CD, C* and b*. MOLM had significant effect (P<0.01) on CD, C*, a*, b*, L*, PRB had significant effect (P<0.01) on h*(increased) and a*(reduced) on colour parameters. MOLM fed at P0 resulted in higher mortality at grower stage. It is concluded that MOLM can be added up to 12% with or without PRB without affecting growth performance at finisher phase and carcass characteristics. Inclusion of MOLM up to 12% had good impact on hardness and water holding capacity in the meat. PRB presence improved the growth performance of birds supplemented with MOLM up to 12% inclusion level. MOLM diets were not economically profitable compared to control diet due to high price level of Moringa oleifera powder supplemented in the diets and no best return weight gain per rand invested amongst the diets. / NRF

Alors que la simulation numérique prend aujourd'hui une place essentielle dans de nombreuses branches de l'ingénierie, les évolutions incroyables des moyens de calculs peinent à compenser la complexité croissante des modèles que les ingénieurs sont amenés à traiter. Dans ce contexte, les modèles réduits sont de véritables outils d'aide à la décision car ils permettent, une fois construits, d'évaluer un très grand nombre de scénarios en temps quasi réel. En particulier, la méthode PGD (Proper Generalized Decomposition) initiée au LMT a connu de très nombreux développements (problèmes non linéaires, multiéchelles, multiphysiques...) et conduit à des gains en temps CPU pouvant atteindre plusieurs ordres de grandeur.Malheureusement, l'essor de ces modèles réduits est actuellement freiné par la difficulté à les calculer lorsque le nombre de paramètres à prendre en compte augmente. Toutes les techniques de réduction de modèles actuelles (PGD comprise) peinent à traiter des problèmes à très grand nombre de paramètres (la limite actuelle tourne autour de la vingtaine de paramètres), ce qui constitue un verrou scientifique majeur pour l'essor de ces techniques. Cette thèse présente une adaptation de la méthode PGD qui permet le traitement de tels problèmes.Trois contributions principales ont permis d'atteindre de telles performances. D'une part, une nouvelle structure de données plus proche de la physique du problème a été développée. Elle introduit deux échelles de représentation des fonctions paramétriques et donne son nom à la méthode : la Parameter-Multiscale PGD. Par ailleurs, une discrétisation spatiale discontinue particulièrement adaptée à nos méthodes de résolution a été implémentée, la WTDG (Weak Trefftz Discontinuous Galerkin). Enfin de nouveaux algorithmes ont été développés pour construire des modèles réduits qui permettent des gains de temps conséquents pour des problèmes ayant jusqu'à mille paramètres. / Numerical simulation is nowadays a major tool in a large number of engineering fields. Nevertheless, even the recent incredible improvements of the computational power can hardly compensate the increasing complexity of the models used by engineers. In this context, Reduced Order Models (ROM) can be major decision-maker tools because, once they have been computed, they can be used to evaluate a very large number of test cases in a duration close to real time. The PGD (Proper Generalized Decomposition) in particular, is a method introduced at the LMT which has been adapted to many cases (non-linear problems, multiscale, multiphysics) and leads to savings of CPU time reaching several orders of magnitude.Unfortunately, it is currently difficult to build ROM with an increasing number of parameters. All the actual model reduction technics (including the PGD) can hardly solve problems with a high number of parameters (the current limit is about twenty parameters). It is a major barrier to a larger development of these methods. This PhD thesis presents a new methodology based on the PGD able to take into account high numbers of parameters.This goal has been achived thanks to three major contributions. First, a new data structure faithfull to mecanical properties of the problem has been developed. To that end, two different scales are introduced in the parametric space, giving its name to our method : Parameter-Multiscale PGD. Furthermore, the WTDG (Weak Treffz Discontinuous Galerkin) method has been inpemented. It is a discontinuous spatial discretisation adapted to our resolution techniques. Finally, new algorithms have been developed to built reduced order models of problems taking into account up to one thousand parameters.

The aim of this study was to determine how the performance of the Egyptian high jumpers is depending on the kinematic parameters of a take-off phase. The sample of the study has been selected from competitors of the high jump event - three jumpers representing the Egyptian international athletic team. The researcher has studied the sample using a direct measurement by a synchronized 3D video system to measure the kinematic parameters. The researcher has found a relation between record level and vertical velocity components with improvement in technique and better fitness levels, thus the Egyptian jumpers can achieve further progress in their results. This raises optimism because Omer Samir (A2) is very young and his current record 2.02m gives hope for future World - Class. Key words High jump, kinematic parameters, take-off phase.

This thesis presents the results of a study of the effect of variations of systemic parameters on the structural response of single degree of freedom systems subjected to Incremental Dynamic Analysis. The systemic parameters are mass, stiffness, damping, yield strength and geometric stiffness. Each of these parameters was varied one at a time while the other values were kept constant. For each variation of parameters a set of single-record IDA curves was obtained. Five to six ground motions were used for this study to generate the single-record IDA curves. These ground motions were scaled prior to their application on the structure. The scaling factor was based on the spectral acceleration at the fundamental frequency of the structure at 5% of critical damping. The scale factor is affected if the system parameters are changed. An important issue for this study was whether to persist with scaling corresponding to the median value from the range of the values of the parameter or to update the scaling according to the system. Based on some tests using both methods, the median scaling approach was found to be more suitable. The IDA curves for variation of parameters were then investigated to identify any trends that may help in qualitatively predicting the response of a system relative to another system. The response was measured by the peak displacement and the maximum base shear of the system. A clear trend was identified when the damping or the yield strength was varied. However, no definite trend was observed when the material stiffness or the geometric stiffness of the system was varied. / Master of Science

It is generally assumed that the implementation of adaptive control requires a precise identification of plant parameters. In the case of a system with varying parameters, the identification problem gets very involved,as speed of identification and accuracy are contradictory requirements. In this thesis it has been shown that using a feedback policy, the optimal controller is relatively· insensitive to changes in plant parameters as long as these lie within some specified ranges. It is, therefore, concluded that, with such an arrangement, adaptive control can be implemented if one has only the knowledge of the ranges within which the parameters of the plant lie. Thus identification can be carried on more rapidly, as stringent accuracy is no longer necessary. / Thesis / Master of Engineering (ME)

The finite element analysis (FEA) is a numerical method widely used to predict the metal-cutting performance in both academic and industrial studies, avoiding the high expense and time consumption of experimental methods. The problem is how to calibrate reliable fracture-parameters as chip-separation criterion are implemented into FEA modelling. This thesis introduces a calibration method of the Johnson-Cook fracture parameters used in the orthogonal metal cutting modelling with a positive rake angle for AISI 1045 steel. These fracture parameters were obtained based on a set of quasi-static tensile tests, with smooth and pre-notched round bars at room temperature and elevated temperatures. The fracture parameters were validated by low- and high-strain rate simulations corresponding to tensile tests and orthogonal metal-cutting processes respectively in ABAQUS/Explicit. Compared to literature calibration methods, this method is simpler, less expensive but valid. / Thesis / Master of Applied Science (MASc)

<p> The lattice parameters and crystal symmetry of silane (SiH4) are examined by X-ray powder diffraction. Comparisons are made with vibrational spectrum and birefringence measurements and with respect to an order-disorder transition between the two solid phases of silane.</p> / Thesis / Master of Science (MSc)