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Valuation of option embedded fixed income securities.January 1998 (has links)
by Matthew Bailey Greenberg, Ng Hin Wah. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 61-62). / ABSTRACT --- p.ii / TABLE OF CONTENTS --- p.iv / Chapter / Chapter I. --- INTRODUCTION --- p.1 / Chapter II. --- CONVERTIBLE BONDS AND WARRANTS --- p.3 / ConvertIBle Bonds --- p.3 / Value At Maturity --- p.5 / Value Before Maturity --- p.6 / Warrants --- p.8 / The Difference Between Convertible Bonds and Warrants --- p.11 / Considerations of Issuing Convertibles and Bond with Warrants --- p.13 / Valuation of Convertible Bond --- p.15 / Valuation of Warrants --- p.18 / Chapter III. --- CALLABLE BONDS --- p.20 / Performance Characteristics of Callable Bonds --- p.21 / Valuation of a Two-year Callable Bond with the Salomon Brothers Model --- p.22 / Valuation of a Three-year Callable Bond with the Salomon Brothers Model --- p.25 / Step1: Determination of ru and rd --- p.27 / "Step 2: Determination of ruu, rud and rdd " --- p.28 / "Black, Derman & Toy Model (BDT) " --- p.30 / Step 1: Determination of ru and rd --- p.31 / "Step 2: Determination of ruu, rud and rdd " --- p.32 / Chapter IV. --- SINKING-FUND BONDS --- p.37 / Advantages for the Investor --- p.38 / Disadvantages for the Investor --- p.38 / Methods Used by Issuers for Early Bond Redemption --- p.39 / Valuation of Non-callable Sinking Fund Bonds --- p.40 / Valuation of Callable Sinking Fund Bond --- p.45 / Chapter V. --- VALUATION OF A CALLABLE BOND BY A COMPUTERIZED PROGRAM… --- p.47 / System requirements --- p.48 / Opening the program file --- p.48 / Manual for using the program --- p.48 / Construction of Interest Rate Tree --- p.48 / Valuation of a Callable Bond --- p.50 / APPENDIX --- p.55 / BIBLIOGRAPHY --- p.61
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Avaliação de tratamentos de superfície em diferentes sistemas cerâmicos e seu efeito na resistência de união a um cimento resinoso /Ribeiro, João Gustavo Rabelo. January 2005 (has links)
Orientador: José Cláudio Martins Segalla / Banca: Regina Helena Barbosa Tavares da Silva / Banca: Marcos Ribeiro Moysés / Resumo: O objetivo deste estudo foi avaliar o efeito de três tratamentos superficiais na resistência de união de um cimento resinoso a três cerâmicas dentais: Duceram Plus (DP), IPS Empress II (IPS) e In-Ceram Alumina (INC), e analisar a topografia superficial dessas cerâmicas submetidas aos mesmos tratamentos superficiais. Para o teste de resistência de união foram confeccionadas 18 amostras de cada material (7,5mm de diâmetro x 3,0mm de espessura), incluídas em resina acrílica e polidas até lixa nº 600. As amostras foram divididas em três grupos: a) jateamento com partículas de óxido de alumínio de 50 æm; b) condicionamento com ácido fluorídrico 10%; c) associação de "a" e "b". As amostras foram lavadas e secas. A área de adesão da cerâmica foi delimitada com matriz metálica perfurada (5,0mm de diâmetro e 3,0mm de espessura). Foi aplicado silano, adesivo e cimento resinoso Variolink II, fotoativado por 40 segundos. As amostras receberam 1000 ciclos térmicos de 5 a 55°C. O ensaio de cisalhamento foi realizado em máquina de ensaios MTS 810, com célula de carga de 10 kN e velocidade de 0,5 mm/min. Para a topografia superficial foram confeccionados um coping de IPS, um do INC e uma coroa de DP, seguindo as recomendações dos fabricantes. Cada coping ou coroa foi cortado com disco diamantado em quatro partes: uma delas não recebeu nenhum tratamento, e as demais receberam um dos tratamentos acima descritos. Fotomicrografias foram obtidas por meio de microscopia eletrônica de varredura e a análise foi feita de acordo com a característica da superfície. Pode-se concluir que: o tratamento associado não ofereceu vantagens em relação ao condicionamento ácido, para os materiais DP e IPS; para o INC o tratamento associado não ofereceu vantagens em relação ao jateamento. A DP e o IPS apresentaram resultados melhores em relação ao INC, independentemente dos tratamentos ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the effect of three surface treatments on the shear bond strength of a resin luting cement to three ceramics materials: Duceram Plus (DP), IPS Empress II (IPS) and In-Ceram Alumina (INC), and to assess its surface topography after these treatments. Eighteen specims were fabricated to each material (7,5 mm in diameter x 3,0 mm in thickness), embebed in acrylic resin and ground up to 600 grit. The specims were randomly divided into 3 groups of 6 specims: (a) airborne particle abrasion with 50 æm aluminum oxide; (b) 10% hydrofluoric acid etching; (c) "a" and "b" treatments. The specims were cleaned and dried. Silane, adhesive and resin luting cement Variolink were applied in 5,0 mm in diameter and 3,0 mm height to ceramic surface and then light cured. All specims were termocycled (1000, 5-55°C). The shear bond strength was then measured in a testing machine MTS 810, at a crosshead speed of 0,5 mm/min. To asses the surface topography, one coping each of IPS and INC, and a DP crown were fabricated following the manufacturer's instructions. Each coping or crown was sectioned into 4 equal parts by a diamond disk. One part didn't receive any treatment, and the others, received treatments as above described. Photomicrographs were obtained by a SEM, and the superficial characteristic was described. In conclusion, the associate treatment didn't offer advantages in relation to the acid etching, for DP and IPS; for INC the associate treatment didn't offer advantages in relation to the airborne. DP and IPS presented the best results, independently of the superficial treatments. The photomicrographs showed compatible correlation of the superficial characteristic with the bond strength values. / Mestre
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Využití matematicko-statistického modelování pro odhady spotřeby fixního kapitálu a stavů nefinančních aktivit / The use of mathematical and statistical modeling for the estimates of consumption of fixed capital and stocks of non-financial assetsSixta, Jaroslav January 2004 (has links)
The aim of this dissertation thesis is to compile a systematic methodical approach for fixed assets as a national methodology. It focuses on stocks, consumption of fixed capital and capital services. The thesis is divided into three parts and six chapters. Chapter one and chapter two are used as a general theoretical base for chapters 3 to 5. Chapter 3 is based on a standard approach to the perpetual inventory method (PIM) as it is used in the Czech Republic. Chapter 4 is devoted to capital services and to an alternative approach to PIM. It is not used in the Czech Republic until now. Estimates are an integral part of the chapter. Chapter 5 describes capital services for other non-market producers, both methodology and estimates are covered. The impact of the change of the so-called cost method used for the estimates of output of other non-market producers on gross domestic product is calculated. The change consists in the substitution of consumption of fixed capital by capital services. Chapter 6 summarizes and explains the consequences in terms of national accounts.
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Dlouhodobý hmotný majetek z pohledu českých účetních předpisů / Tangible fixed assets from the perspective of Czech accounting standardsDolejší, Lukáš January 2010 (has links)
The thesis is focused on accounting of tangible fixed assets from the perspective of Czech accounting standards. The aim is to describe accounting for acquisition, usage and disposal of tangible fixed assets. The thesis also analyzes different kinds of tangible fixed assets valuation and depreciation. Theoretical knowledge is applied to accounting of tangible fixed assets by Bohemia Asfalt, Ltd.
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Sincronização da ovulação para a inseminação artificial em tempo fixo (IATF) durante a estação reprodutiva desfavorável em fêmeas bubalinas / Synchronization of ovulation for fixed-time artificial insemination (FTAI) during the off breeding season in buffalo.Roberto Mendes Porto Filho 29 September 2004 (has links)
Foram comparadas diferentes doses de eCG e hCG associadas a dispositivos intravaginais de progesterona (DIV), para avaliar o crescimento folicular e a ovulação, bem como a taxa de prenhez após a IATF e a funcionalidade do CL 12 dias após a sincronização em búfalas, durante a estação reprodutiva desfavorável. Para tanto, foram realizados cinco experimentos. Nos experimentos 1, 2 e 4, os grupos foram estabelecidos em função da ciclicidade dos animais, avaliada pelas concentrações plasmáticas de progesterona mediante colheita de sangue por punção da veia jugular no D-10 e no D0. Nos experimentos 3 e 5, os grupos foram estabelecidos em função da condição corporal e da ordem de parto. Em todos os experimentos as búfalas receberam um DIV associado a 2mg de Benzoato de Estradiol (BE) no D0. No D9 o DIV foi retirado, e procedeu-se à administração de 0,150mg de prostaglandina (PGF). No experimento 1, as búfalas do G1 (Controle, n=9) e do G2 (eCG, n=10) receberam 1500UI de hCG no D11; o G2 recebeu também 500UI de eCG no D-9; a IATF foi realizada no D12. Nesse experimento, o diâmetro máximo do folículo dominante (DMFD) foi de 12,6 ± 3,0 e 13,4 ± 1,7mm para o G1 e o G2, respectivamente (P>0,05); o diâmetro do folículo ovulatório (DFO) foi de 14,9 ± 2,9 (G1) e de 14,0 ± 1,6mm (G2; P>0,05); o intervalo entre a retirada do DIV e a ovulação (IROV) foi de 78,0 ± 12 (G1) e 68,0 ± 9,0h (G2; P>0,05); a taxa de ovulação (TO) foi de 44,4 (G1) e 70,0% (G2; P> 0,05). A área do CL (ACL) foi de 31,6 ± 19,9 (G1) e de 29,9 ± 9,7mm2 (G2; P>0,05); a concentração plasmática de P4 (P4) foi de 1,3 ± 1,4 (G1) e 2,0 ± 1,6ng/ml (G2; P>0,05); a taxa de prenhez (TP) foi de 22,2 (G1) e 60% (G2; P=0,11). No experimento 2, as búfalas do G1 (1500 UI de hCG; n=21) e do G2 (1000UI de hCG; n=21) receberam 500UI de eCG no D9; no D11, o G1 recebeu 1500UI de hCG e o G2 1000UI de hCG. Os resultados desse experimento são relatados a seguir: DMFD de 12,4 ± 2,3 (G1) e 12,2 ± 2,5mm (G2; P>0,05); DFO de 12,6 ± 2,3 (G1) e 12,5 ± 2,7mm (G2; P>0,05); IROV de 67,7 ± 18,1 (G1) e 72,8 ± 16,7h (G2; P>0,05); TO de 67,7 (G1) e 67,7% (G2; P>0,05); ACL de 24,8 ± 9,2 (G1) e 28,3 ± 17,2mm2 (G2; P>0,05); P4 de 2,3 ± 1,4 (G1) e 2,4 ± 1,3ng/ml (G2; P>0,05). No experimento 3, os animais foram tratados de forma idêntica àqueles do experimento 2, porém as búfalas do G1 (n=83) e do G2 (n=91) receberam a IATF no D12. Nesse experimento, foi obtida TP de 53 (G1) e de 53,8% (G2; P>0,05). No Experimento 4, as búfalas do G1 (n=10) receberam 500UI e as do G2 (n=11) 400UI de eCG; os dois grupos receberam 1000UI de hCG no D11. Esse experimento teve como resultados: DMFD de 13,2 ± 1,4 (G1) e 13,8 ± 1,8mm (G2; P>0,05); DFO de 13,7 ± 1,1 (G1) e 14,2 ± 1,5mm (G2; P>0,05); IROV de 71,1 ± 11,7 (G1) e 75,0 ± 5,5h (G2; P>0,05); TO de 70,0 (G1) e 72,7% (G2; P>0,05); ACL de 28,4 ± 8,6 (G1) e 31,6 ± 10,3mm2 (G2; P>0,05); P4 de 2,7 ± 1,2 (G1) e 3,3 ± 2,9ng/ml (G2; P>0,05). No experimento 5 (G1/n=54; G2/n=51) foi adotado o mesmo protocolo do experimento 4, porém as búfalas receberam a IATF no D12. Esse experimento resultou em TP de 42,6 (G1) e 43,1% (G2; P>0,05). Assim, foi possível concluir que as concentrações de 400UI de eCG e de 1000UI de hCG, associadas ao DIV, foram suficientes para induzir o crescimento folicular, a ovulação e a prenhez em búfalas durante o período reprodutivo desfavorável. / Different dosage of eCG and hCG were compared in association to progesterone intravaginal device (IVD) in female buffalo during the off breeding season with the purpose of evaluating the follicular growing and ovulation as well as the pregnancy rate after FTAI and functionality of the CL, twelve days after the synchronization. For this, 5 experiments were done. For the establishments of the groups in the experiments 1,2 and 4 blood samples were collected for the analysis of plasmatic concentrations of P4 on D -10 and D0 to verify the cyclicity. In the experiments 3 and 5 the groups were established due body condition score and number of calving. In all the experiments the buffaloes received a IVD associated with 2mg of estradiol benzoate (EB) on D0. On D9 the IVD was extracted and it was followed by the administration of 0,150mg of prostaglandin (PGF). In the exp. 1 the buffaloes of G1 (control, n=9) and G2 (eCG, n=10) received 1500IU of hCG on D11. On G2 was administrated 500IU of eCG on D9. The FTAI was done on D12. The maximun diameter of dominant follicle (MDDF) was 12.6 ± 3.0 and 13.4 ± 1.7mm to the G1 and G2, respectively (P>0,05). The diameter of the ovulatory follicle (DOF) was 14.9 ± 2.9 (G1) and 14.0 ± 1.6mm (G2; P>0,05). The interval between the device withdrawn and ovulation (DWO) was 78.0 ± 12.0 (G1) and 68.0 ± 9.0h (G2; P>0,05). The ovulation rate (OR) was 44.4 (G1) and 70.0% (G2; P>0,05). The CL area (CLA) was 31.6 ± 19.9 (G1) and 29.9 ± 9.7mm2 (G2; P>0,05). The plasmatic concentration of P4 (P4) was 1.3 ± 1.4 (G1) and 2.0 ± 1.6ng/ml (G2; P>0,05). The pregnancy rate (PR) was 22.2 (G1) and 60% (G2; P=0,11). In the exp. 2 the buffalo females of G1 (1500IU of hCG; n=21) and G2 (1000IU of hCG; n=21) received 500IU of eCG on D9. On D11, G1 received 1500IU of hCG and G2 1000IU of hCG. The MDDF was 12.4 ± 2.3 (G1) and 12.2 ± 2.5mm (G2; P>0,05), the DOF was 12.6 ± 2.3 (G1) and 12.5 ± 2.7mm (G2; P>0,05), DWO was 67.7 ± 18.1 (G1) and 72.8 ± 16.7h (G2; P>0,05), the OR was 67.7 (G1) and 67.7% (G2; P>0,05), the CLA was 24.8 ± 9.2 (G1) and 28.3 ± 17.2mm2 (G2; P>0,05) and the P4 was 2.3 ± 1.4 (G1) and 2.4 ± 1.3ng/ml (G2; P>0,05). The exp. 3 was identical to exp.2, although the animals of G1 (n=83) and G2 (n=91) received the FTAI on D12. The PR was 53.0 (G1) and 53,8% (G2; P>0,05). In exp. 4, the animals of G1 (n=10) received 500IU and G2 (n=11) 400IU of eCG. Both groups received 1000IU of hCG on D11. The MDDF was 13.2 ± 1.4 (G1) and 13.8 ± 1.8mm (G2; P>0,05), the DOF was 13.7 ± 1.1 (G1) and 14.2 ± 1.5mm (G2; P>0,05), the DWO was 71.1 ± 11.7 (G1) and 75.0 ± 5.5h (G2; P>0,05), the OR was 70.0 (G1) and 72.7% (G2; P>0,05), the CLA was 28.4 ± 8.6 (G1) and 31.6 ± 10.3mm2 (G2; P>0,05) and the P4 was 2.7 ± 1.2 (G1) and 3.3 ± 2.9ng/ml (G2; P>0,05). In exp. 5 (G1/n=54; G2/n=51) was done the same protocol in the exp. 4, although the animals received the FTAI on D12. The PR was 42.6 (G1) and 43.1% (G2; P>0,05). Dosage of 400IU of eCG and 1000IU of hCG, associated to IVD for FTAI were enough to induce follicular growing, ovulation and pregnancy in buffalo females during the off breeding season.
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Sêmen refrigerado bovino reduz os danos espermáticos e aumenta a taxa de prenhez na IATF? / Does the bovine cooled semen reduces sperm damage and increases the pregnancy rate in the FTAI?Octavio Fabián Bao Tarragó 22 February 2017 (has links)
O objetivo do presente estudo foi avaliar a viabilidade da refrigeração do sêmen bovino comparada com a criopreservação. Este estudo foi realizado em dois experimentos. No primeiro experimento foram comparados os efeitos in vitro do sêmen refrigerado em três meios diluidores comerciais a 5° C por até 48 horas, e criopreservado em dois meios. Para este experimento foram utilizados ejaculados de 10 touros da raça Nelore. Cada ejaculado foi dividido em três alíquotas, sendo diluídas nos meios Botubov®, Steridyl® e Bovidyl®. Após a diluição o sêmen foi envasado em palhetas e refrigerado nos três diluidores e criopreservado utilizando somente os meios Botubov® e Steridyl®. A refrigeração do sêmen foi realizada a 5° C por até 48 horas em sistema passivo de refrigeração BotuFlex® e a criopreservação realizada em sistema automatizado TK 4.000®. O sêmen foi avaliado nos tempos 0, 24, 36 e 48 horas após a refrigeração e após a descongelação, para cada diluidor. Foram realizadas análises dos padrões de cinética espermática pelo sistema computadorizado de análise espermática (CASA, programa SCA - Sperm Class Analyser), integridade das membranas plasmática e acrossomal, potencial de membrana mitocondrial e estresse oxidativo por sondas fluorescentes, sob microscopia de epifluorescência e morfologia espermática por microspcopia de contraste de interferência diferencial (DIC). Notou-se efeito de tempo de refrigeração para os três diluidores para de 0 para 24h, se mantendo semelhante até 48 h. Os diluiores Botubov® e Steridyl® preservaram as características espermáticas de forma semelhante até 48 horas de refrigeração diferindo apenas na variável de velocidade curvilianear; no entanto, ambos foram superiores ao diluidor Bovidyl®, para as variáveis, motilidade total, motilidade progressiva, células rápidas, velocidade curvilinear, velocidade progressiva, velocidade do trajeto, retilinearidade, integridade da membrana plasmática, alto potencial de mitocondrial e espermatozoides com membranas plasmática e acrossomal íntegras e alto potencial mitocondrial. O segundo experimento foi realizado, baseado nos resultados do primeiro experimento, para avaliar os efeitos da refrigeração e da criopreservação do sêmen sobre a fertilidade in vivo. Foram utilizados ejaculados de três touros das raças Brangus, Braford e Angus, com idade entre 5 e 7 anos. O sêmen foi colhido por meio de vagina artificial, o ejaculado foi dividido em três alíquotas, sendo duas alíquotas para refrigeração e uma para criopreservação. Para a refrigeração o sêmen foi diluído nas concentrações de 15x106 (R15) e 30x106 (R30) espermatozoides/palheta e para a criopreservação diluído na concentração de 30x106 espermatozoides/palheta (CRIO). Para todas as diluições foi utilizado o meio Botubov® e o sêmen armazenado em palhetas de 0,5 mL. A refrigeração foi realizada a temperatura de 5° C por 48 horas em sistema passivo de refrigeração BotuFlex® e a criopreservação em sistema automatizado TK®. Foram sincronizadas 552 vacas da raça Brangus em programas de inseminação artificial em tempo fixo. Os resultados da taxa de prenhez para os grupos de vacas inseminadas foram de 49,4% para R15, 43,38% para R30 e 47,59% para o sêmen criopreservado. Pode-se concluir que a refrigeração do sêmen a 5° C por 48 horas resulta em taxa de prenhez semelhante às obtidas com o sêmen criopreservado, sendo que esses resultados indicam que a refrigeração por até 48 horas pode ser uma opção de uso para IATF. / The objective of the present study was to evaluate the viability of cooling bovine semen compared to cryopreservation. This study was carried out in two experiments. In the first experiment, the in vitro effects of cooled semen were compared in three commercial extenders at 5° C for up to 48 hours, and cryopreserved in two extender. For this experiment were used ejaculates of 10 Nellore bulls. Each ejaculate was divided into three aliquots, being diluted in the Botubov®, Steridyl® and Bovidyl® extenders. After dilution, the semen was cooled into three extenders and cryopreserved using the Botubov® and Steridyl®. Semen refrigeration was performed at 5° C for up to 48 hours in BotuFlex® passive refrigeration system and cryopreservation performed in TK 3.000® automated system. Semen was evaluated at 0, 24, 36 and 48 hours after refrigeration and after thawing, for each diluent. The sperm kinetics of the spermatic kinetics (CASA, SCA - Sperm Class Analyzer), plasma and acrosomal membrane integrity, mitochondrial membrane potential and oxidative stress by fluorescent probes were analyzed under epifluorescence microscopy and sperm morphology By Differential Interference Contrast Microscopy (DIC). The Botubov® and Steridyl® diluents were very similar after 48 hours of cooling differing significantly only in the Curvilianear Velocity (VCL) 106.04 m/s and 124.56 m/s. The Bovidyl® diluent yielded results significantly lower than the 48 hours of refrigeration for the variables: total motility (MT), progressive motility (MPRO), fast cells (RAP), curvilinear velocity (VCL), progressive velocity (AP), plasma membrane integrity (PI), high mitochondrial potential (AP), and spermatozoa with intact plasma and acrosomal membranes and high mitochondrial potential (PIAIA). The second experiment was carried out, based on the results of the first experiment I, to evaluate the effects of cooled and cryopreservation of semen on in vivo fertility. We used ejaculates of three bulls of the Brangus, Braford and Angus breeds of a IA center, aged between 5 and 7 years. The semen was collected by artificial vagina, the ejaculate was divided into three aliquots, two aliquots for refrigeration and one for cryopreservation. For cooling, the semen was diluted in the concentrations of 15x106 (R15) and 30x106 (R30) spermatozoa/straw, for cryopreservation diluted in the concentration of 30x106 spermatozoa / vane (CRIO). For all dilutions, the Botubov® medium and the semen stored in 0.5 mL vial were used. Refrigeration was carried out at a temperature of 5° C for 48 hours in BotuFlex® passive refrigeration system and cryopreservation in an automated TK® system. 552 Brangus cows were synchronized in fixed-time artificial insemination programs. The results of the pregnancy rate for the groups of inseminated cows were 49.4% for R15, 43.38% for R30 and 47.59% for cryopreserved semen. It can be concluded that the cooling of the semen at 5° C for 48 hours results in pregnancy rate similar to those obtained with cryopreserved semen, and these results indicate that refrigeration for up to 48 hours may be an option of use for FTAI.
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Análise do efeito da precisão finita no algoritmo adaptativo sigmoidal / Analysis of the effect of finite precision on the sigmoidal adaptive algorithmFonseca, José de Ribamar Silva 16 February 2017 (has links)
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Previous issue date: 2017-02-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) / The adaptive filtering is currently an important tool in the statistical processing
of signals, especially when it is necessary to process signals from environments with
unknown statistics varying with time. The adaptive filtering study was driven by the development
of the Least Mean Square algorithm (LMS) in 1960. Since then other adaptive
algorithms have come up with a better performance than LMS algorithm with respect to
misadjustment and convergence rate. Among them, the Sigmoidal algorithm (SA) which
showed superior to the LMS, for the convergence rate and the mismatch in their implementations
infinite precision. In hardware devices such as DSPs, microcontrollers and
FPGAs, adaptive algorithms are implemented in finite precision, in general, fixed point
arithmetic. When the adaptive filters are implemented in finite precision some effects
can affect their performance. Ultimately lead to divergence due to quantization errors
specified in the approximation process of the variables involved in the adaptive processing
of their original values. Thus, this article aims to analyze the performance of the adaptive
algorithm Sigmoidal (SA) in finite precision when implemented using fixed-point arithmetic.
In particular, the analysis of its performance curve and mismatch, comparing them
in different word lengths (number of bits). The results presented in this article proposes
a series of Taylor Ln gradient of cost function (cosh αe) algorithm SA for implementation
in finite precision. We analyze its performance curve for different lengths of words. It
shows that the algorithm is stable in its performance compared to convergence to different
lengths of words, and that the increase in mismatch level at steady state is sensitive or
afected by the quantization of the variables involved in the calculations of this algorithm. / A filtragem adaptativa constitui atualmente uma ferramenta importante no
processamento estatístico de sinais, especialmente quando é necessário processar sinais
provenientes de ambientes com estatísticas desconhecidas que variam com o tempo. O estudo
de filtragem adaptativa foi impulsionado com o desenvolvimento do algoritmo Least
Mean Square (LMS) em 1960. Desde então outros algoritmos adaptativos têm surgido
com um desempenho superior ao algoritmo LMS em relação ao desajuste e à taxa de
convergência. Entre eles, o algoritmo Sigmoidal (SA) que se apresentou superior ao LMS,
em relação a taxa de convergência e o desajuste em suas implementações na forma analógica.
Nos dispositivos de hardware, tais como DSPs, Microcontroladores e FPGAs, os
algoritmos adaptativos são implementados na forma digital, onde a precisão é finita, em
geral, com aritmética de ponto fixo. Quando os filtros adaptativos são implementados
em precisão finita alguns efeitos podem afetar o seu desempenho. Em última análise,
levar à divergência devido aos erros de quantização especificados no processo de aproximação
dos valores das variáveis envolvidas no processamento adaptativo de seus valores
originais. Assim, este trabalho propõe analisar o desempenho do algoritmo adaptativo
Sigmoidal (SA) em precisão nita, quando implementado utilizando aritmética de ponto
xo. Em particular, a análise de sua curva de desempenho e o desajuste, comparando-os
em diferentes comprimentos de palavras (número de bits). Os resultados apresentados
neste trabalho propõe uma aproximação em série de Taylor do gradiente da função de
custo Ln(cosh αe) do algoritmo SA para implementação em precisão finita. Analisamos
a sua curva de desempenho para diferentes comprimentos de palavras. Mostra-se que
o algoritmo apresenta estabilidade em seu desempenho em relação à convergência, para
diferentes comprimentos de palavras, e que o aumento no nível do desajuste em estado estacionário
é sensível ou influenciado pela quantização dos valores das variáveis envolvidas
nos cálculos desse algoritmo.
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A An?lise da Teledensidade como Contribui??o ao Entendimento dos Fatores Estrat?gicos ? Sustentabilidade Das Empresas Concession?rias de Telefonia Fixa Brasileiras / The Teledensity Analysis as Contribuition to the Agreement of the Strategic Factors for the Sustentation of the Companies Concessionaries of Fixed Brazilian Telephony.Figueira Filho, H?lio Fernandez 24 August 2006 (has links)
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Previous issue date: 2006-08-24 / This dissertation deals with the dynamic environment regarding the Brazilian residential
telephone service established since its privatization, in 1997. The territorial division made by
players with distinct strategies, all followed by a strict federal law, and the existence of a
regulation organ for telecom services (ANATEL) contributed for the continuous expansion
suffered by the sector between 1997 and 2003. At the same time, the mobile telephone industry
revealed its competitive side, willing to increase its participation in this newborn market share.
Considering this context, we search and present the theoretical and practical concepts for
companies that offer residential telephone services so they can use them to create marketing
strategies in order to defend themselves from the mobile telephone service threat and assure its
sustentability as well. By using marketing concepts, wich allows the correct interaction between
companies and the market, we add the possibility of using a statistic tool, specifically the linear
regression type, that can point out the influence degree on different customers by the current and
future demand for residential phone services. This right perception, even before the strategy
itself, is fundamental condition for the future decision making regarding this sector of services.
By analyzing the telephone market, a line is drawn between the present time, solid but with no
further growth perspectives, and the future, that hides threats and opportunities in several
segments, obliging companies to constantly study the customer s behave, each day more
demanding, but still undefined. The segmentation concept, acquired by the analysis of the
variables available that presented influence in the volume of residential phones in use,
demonstrates the importance of the social classes and customer companies in the agreement and
demand of the services offered. From this facts, the work has its closure by concluding that, if
there is any group of consumers that demonstrates its force by the numbers of telephone lines in
use, there is another one that is more vulnerable to the cancellation of the existing lines. / Esta disserta??o apresenta a forte din?mica apresentada pelo setor de telefonia fixa no mercado
brasileiro a partir de sua privatiza??o, em 1997. A divis?o do territ?rio brasileiro entre empresas
com estrat?gias distintas e tendo como ponto comum uma forte legisla??o federal, acompanhada
de um ?rg?o regulador (ANATEL), fomentou este crescimento at? 2003. No mesmo per?odo a
telefonia m?vel mostrou-se competitiva e capaz de disputar este mercado ainda em forma??o.
Partindo deste contexto, s?o pesquisados e apresentados os subs?dios te?ricos necess?rios ?s
empresas concession?rias de telefonia fixa para que, atrav?s do entendimento do cen?rio atual,
possam ser criadas estrat?gias que garantam sua sustentabilidade frente ? amea?a da telefonia
m?vel. Aos conceitos de marketing, que possibilitam o correto encadeamento de etapas de
an?lise da intera??o empresa/mercado, soma-se a possibilidade de uso de ferramenta estat?stica,
mais exatamente a regress?o linear, capaz de utilizar segmentos de mercado na pondera??o da
influ?ncia de grupos distintos de consumidores na demanda atual e futura de acessos fixos. Esta
percep??o correta, antes mesmo da defini??o da estrat?gia, ? condi??o sine qua non para a
tomada de decis?o sobre o futuro deste setor da economia. Faz-se assim uma caminhada entre o
presente, que se mostra forte por?m sem grandes perspectivas de crescimento, e o futuro, que
esconde amea?as e oportunidades em diferentes segmentos, exigindo das organiza??es modelos
distintos de acompanhamento de um mercado consumidor heterog?neo e exigente, por?m ainda
n?o definido. A segmenta??o, obtida pela an?lise das vari?veis dispon?veis que apresentaram
influ?ncia no volume de acessos fixos em uso, demonstra a import?ncia das classes sociais e das
empresas consumidoras no entendimento e na demanda dos servi?os oferecidos. A partir desta
constata??o, o trabalho se conclui com a avalia??o de que, se existe um grupo de consumidores
que demonstra sua for?a pela quantidade de linhas em uso, existe outro que se apresenta mais
vulner?vel ao cancelamento das linhas existentes.
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Reator anaeróbio- aeróbio com recirculação da fase líquida aplicado ao tratamento de efluente de abatedouro de aves / Anaerobic- aerobic reactor with recirculation of the liquid phase applied to poultry slaughterhouse wastewater treatmentLopes, Carla Limberger 17 February 2016 (has links)
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Previous issue date: 2016-02-17 / The aim of this study was to evaluate a combined anaerobic-aerobic upflow fixed-bed reactor with recirculation of the liquid phase for the removal of nitrogen and organic matter from poultry slaughterhouse wastewater. The reactor was made of an acrylic tube of internal diameter of 93 mm and the length of 1000 mm with a useful volume of 5.6 L being 3.5 L corresponding to the anaerobic compartments and 2.1 L to the aerobic one. The bed for immobilization of the biomass was formed by expanded clay and polyurethane foam. For discussing the results, this study was divided into three articles. In the first article, was evaluated the reactor performance with respect to the elimination of nitrogen (≈65 mg.NT.L-1) and organic matter (≈600 mg.DQO.L-1) due to the recirculation rate (R = 0.5, 1 and 2) and the hydraulic retention time (HRT) of 11 h (6.8 h in anaerobic condition and 4.2 h in aerobic condition) over the time. The best operating condition was obtained at the recirculating rate of 2. In this condition, the total nitrogen removal was 65% with the effluent concentration of 6 mg.NH4+.L-1 e 12 mg.NO3-.L-1. For all condition, the organic matter removal was greater than to 95% with the effluent concentration of approximately 20 mg.COD.L-1. Thus, the increasing of the recirculation rate influenced positively in the reactor performance. In the second article, the hydraulic detention time was evaluated (HDT) at 14 h, 11 h and 8 h with the recirculation rate (R) of 0.5 (Step I), R = 1 (Step II) and R 2 = (Step III). The affluent average concentrations were 65 mg.NT.L-1, 580 mg.COD.L-1, 77 mg L-1 of total alkalinity and pH of 6.4. The samples were collected inlet and output of each compartment along the reactor height. In the Step I, the nitrification efficiencies were 76%, 70% and 41% respectively for 14 h, 8 h and 11 h, showing the effect of HRT. In all steps, the alkalinity has been regarded as the limiting factor of the process and its deficit was 10 to 30%. It was attributed to this factor the low efficiency of total nitrogen removal of about 45%. Throughout the experiment the removal efficiency of organic matter in terms of chemical oxygen demand (COD) was over 90% and made to fit the first order kinetic model for degradation of the substrate. In the third article, was evaluated the hydrodynamic behavior of this system, through stimulus response tests using eosin Y dye as tracer. It has been evaluated the hydraulic retention time of 8 h with three recirculation rates, of .0.5, 1 and 2 times. Under these conditions, the removal of organic matter was greater than 90% and nitrogen conversion was favored by applying lower loads of (0.18 Kg.N.m-3.d-1). It was found that the hydrodynamic evaluation showed the continuous-stirred reactors behavior with 2 to 2.5 reactors in series (N-CSTR). / O objetivo desse trabalho foi avaliar um reator combinado anaeróbio-aeróbio de leito fixo e fluxo ascendente com recirculação da fase líquida, para a remoção de nitrogênio e matéria orgânica proveniente de água residuária de abatedouro de aves. O reator foi confeccionado em um tubo de acrílico de diâmetro interno de 93 mm e comprimento de 1000 mm, com volume útil de 5,6 L, sendo 3,5 L correspondentes aos compartimentos anaeróbios e 2,1 L correspondentes ao compartimento aeróbio. O leito para a imobilização da biomassa foi formado por argila expandida e espuma de poliuretano. A apresentação desse trabalho foi dividida em três artigos. No primeiro artigo, avaliou-se o desempenho do reator em relação à remoção de nitrogênio (≈65 mg.N.L-1) e de matéria orgânica (≈600 mg.DQO.L-1) em função da taxa de recirculação (R=0,5; 1 e 2) e do tempo de detenção hidráulica (TDH) de 11 horas (6,8 horas na condição anaeróbia e 4,2 horas na condição aeróbia), ao longo do tempo. A melhor condição operacional foi obtida com taxa de recirculação de 2. Nessa condição, a eficiência de remoção de nitrogênio total foi de 65% com concentrações efluentes de 6 mg.NH4+.L-1 e 12 mg.NO3-.L-1. Para todas as condições testadas, a eficiência de remoção de matéria orgânica apresentou-se superior a 95%, com concentração efluente de aproximadamente 20 mg.DQO.L-1. Assim, o aumento da taxa de recirculação influenciou positivamente no desempenho do reator. No segundo artigo, avaliaram-se os tempos de detenção hidráulica (TDH) de 14 horas, 11 horas e 8 horas com taxa de recirculação (R) de 0,5 (Ensaio I), R=1 (Ensaio II) e R=2 (Ensaio III). As concentrações médias afluentes foram 65 mg.NT.L-1, 580 mg.DQO.L-1, 77 mg.L-1 de alcalinidade total e pH de 6,4. As amostras foram coletadas na entrada e saída de cada compartimento, ao longo da altura do reator. Na Etapa I, e as eficiências de nitrificação foram de 76%, 70% e 41%, respectivamente para 14 horas, 11 horas e 8 horas, evidenciando o efeito do TDH. Em todas as etapas, a alcalinidade foi considerada o fator limitante do processo e o seu déficit variou de 10% a 30%. Atribuiu-se a esse fator a baixa eficiência na eliminação de nitrogênio total de aproximadamente 45%. Durante todo o experimento, a eficiência de remoção de matéria orgânica em termos de demanda química de oxigênio (DQO) foi superior a 90% e apresentou ajuste ao modelo cinético de primeira ordem para a degradação do substrato. No terceiro artigo, avaliou-se o comportamento hidrodinâmico desse sistema, a partir de ensaios de estímulo resposta utilizando o traçador Eosina Y. Avaliou-se o tempo de detenção hidráulica de 8 horas com as três taxas de recirculação, de 0,5, 1 e 2 vezes. Nessas condições, a remoção de matéria orgânica foi superior a 90% e a conversão de nitrogênio foi beneficiada com a aplicação de cargas menores (0,18 Kg.N.m-3.d-1). Na avaliação hidrodinâmica verificou-se que o reator apresentou comportamento de reator de mistura completa com 2 a 2,5 reatores em série (N-CSTR).
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Learning and loss aversion : evidence from a financial betting marketÓ Briain, Tomás January 2016 (has links)
This research is motivated by a number of open questions in the behavioural finance literature. Firstly, if investors do not learn in a rational Bayesian manner but rather suffer from biases set out in the naïve reinforcement hypothesis, rationality assumptions in individual preference models may not hold. I use a unique longitudinal dataset comprising in excess of 1.5 million fixed-odds financial bets, where bettors perform identical, consecutive decisions which mimic financial choices made in a laboratory, but the use of their own funds departs from the artificiality of an experiment. I present evidence of unwarranted overconfidence generated by reinforcement learning in both real and simulated markets. Secondly, Kahneman and Tversky (1979) state that losses loom larger than gains. I examine whether the disposition to avoid losses is driving behaviour in the losing domain in the dataset and conclude that there is little evidence of loss aversion. I differentiate between betting on Financial Markets, in which agents may perceive an internal locus of control, and betting on the simulated market, where results are uncorrelated and in which the emotions of regret and disappointment may not loom as large. Finally, Odean (1998) provides evidence that investors readily realise paper gains by selling their winning stocks, yet hold on to their losing stocks too long. This loss aversion is consistent with Kahneman and Tversky (1979) prospect theory, however, how long would the investor hold on to a stock that is losing value on a day-to-day basis? Conversely, would an investor rush to sell a stock that has yielded positive returns in each month during the past year? I test the interaction between learning and loss aversion in a financial betting experiment in which two treatment groups are subjected to consecutive gains or losses.
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