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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A framework for modeling the liquidity and interest rate risk of demand deposits / Ett ramverk för att modellera likviditets- och ränterisk för inlåning

Henningsson, Peter, Skoglund, Christina January 2016 (has links)
The objective of this report is to carry out a pre-study and develop a framework for how the liquidity and interest rate risk of a bank's demand deposits can be modeled. This is done by first calibrating a Vasicek short rate model and then deriving models for the bank's deposit volume and deposit rate using multiple regression. The volume model and the deposit rate model are used to determine the liquidity and interest rate risk, which is done separately. The liquidity risk is determined by a liquidity quantile which estimates the minimum deposit volume that is expected to remain in the bank over a given time period. The interest rate risk is quantified by an arbitrage-free valuation of the demand deposit which can be used to determine the sensitivity of the net present value of the demand deposit caused by a parallel shift in the market rates. Furthermore, an immunization and a replicating portfolio are constructed and the performances of these are tested when introducing the same parallel shifts in the market rates as in the valuation of the demand deposit. The conclusion of this thesis is that the framework for the liquidity risk management that is developed gave satisfactory results and could be used by the bank if the deposit volume is estimated on representative data and a more accurate model for the short rate is used. The interest rate risk framework did however not yield as reliable results and would be more challenging to implement as a more advanced model for the deposit rate is required. / Målet med denna rapport är att utveckla ett ramverk för att bestämma likviditets-och ränterisken som är relaterad till en banks inlåningsvolym. Detta görs genom att först ta fram en modell för korträntan via kalibrering av en Vasicek modell. Därefter utvecklas, genom multipelregression, modeller för att beskriva bankens inlåningsvolym och inlåningsränta. Dessa modeller används för att kvantifiera likviditets- och ränterisken för inlånings-volymen, vilka beräknas och presenteras separat. Likviditetsrisken bestäms genom att en likviditetskvantil tas fram, vilken estimerar den minimala inlånings-volymen som förväntas kvarstå hos banken över en given tidsperiod. Ränterisken kvantifieras med en arbitragefri värdering av inlåningen och resultatet används för att bestämma känsligheten för hur nuvärdet av inlåningsvolymen påverkas av ett parallellskifte. Utöver detta bestäms en immuniseringsportfölj samt en rep-likerande portfölj och resultatet av dessa utvärderas mot hur nuvärdet förändras givet att samma parallellskifte i ränteläget som tidigare introduceras. Slutsatsen av projektet är att det framtagna ramverket för att bestämma likviditetsrisken för inlåningen gav bra resultat och skulle kunna implementeras i dagsläget av banken, förutsatt att volymmodellen estimeras på representativ data samt att en bättre modell för korträntan används. Ramverket för att bestämma ränterisken gav dock inte lika tillförlitliga resultat och är mer utmanande att implementera då en mer avancerad modell för inlåningsräntan krävs.
22

An Attempt at Pricing Zero-Coupon Bonds under the Vasicek Model with a Mean Reverting Stochastic Volatility Factor / Ett Försök att Prisätta Nollkupongobligationer med hjälp av Vasicekmodellen med en Jämviktspendlande Stokastisk Volatilitetsfaktor

Neander, Benjamin, Mattson, Victor January 2023 (has links)
Empirical evidence indicates that the volatility in asset prices is not constant, but varies over time. However, many simple models for asset pricing rest on an assumption of constancy. In this thesis we analyse the zero-coupon bond price under a two-factor Vasicek model, where both the short rate and its volatility follow Ornstein-Uhlenbeck processes. Yield curves based on the two-factor model are then compared to those obtained from the standard Vasicek model with constant volatility. The simulated yield curves from the two-factor model exhibit "humps" that can be observed in the market, but which cannot be obtained from the standard model. / Det finns empiriska bevis som indikerar att volatiliteten i finansiella marknader inte är konstant, utan varierar över tiden. Dock så utgår många enkla modeller för tillgångsprisättning från ett antagande om konstans. I det här examensarbetet analyserar vi priset på nollkupongobligationer under en stokastisk Vasicekmodell, där både den korta räntan och dess volatilitet följer Ornstein-Uhlenbeck processer. De räntekurvor som tas fram genom två-faktormodellen jämförs sedan med de kurvor som erhålls genom den enkla Vasicekmodellen med konstant volatilitet. De simulerade räntekurvorna från två-faktormodellen uppvisar "pucklar" som kan urskiljas i marknaden, men som inte kan erhållas genom standardmodellen.
23

Regression Modeling of Time to Event Data Using the Ornstein-Uhlenbeck Process

Erich, Roger Alan 16 August 2012 (has links)
No description available.
24

可轉換公司債存續期間之分析 / Anatomy of the convertible bond duration

陳嘉霖, Cheb, Chia-Lin Unknown Date (has links)
論文名稱:可轉換公司債存續期間之分析 校所組別:國立政治大學金融研究所 畢業時間:九十年度第二學期 提要別:碩士學位論文提要 研究生:陳嘉霖 指導教授:陳松男博士 論文提要及內容: 本研究在分析可轉債的存續期間,在存續期間的衡量上是採用有效存續期間法;而在可轉換公司債的評價上,假設股票價格服從幾何布朗寧運動,無風險利率的變動符合Hu1I-white利率模型,並且考量利率與股票報酬之間的相關性,建立可轉換公司債評價六元樹形圖。 本研究分別針對到期期限長短、價內外程度、股價波動度、利率波動度、股價與利率相關係數及票面利率等六項參數,作可轉換公司債存續期間的敏感度分析,研究結果為:1 加入贖回條款後,可轉債的存續期間高於未加任何條款下的可轉債存續期間。2 加入賣回條款後,可轉債的存續期間低於未加任何條款下的可轉債存續期間。3 加入贖回及賣回候款後,可轉債的存續期間會介於僅含贖回條款與僅含賣回條款的存續期間之中。4 距到期日愈長可轉債的存續期間愈高。5 愈價外的可轉債其存續期間愈高。6 股票波動度愈高,可轉債的存續期間愈低。7 利率波動度增加則可轉債的存續期間上升。8 股票價格與利率相關係數由正至負,可轉債的存續期間上升。9 若贖回權愈小,則票息上升會增加可轉債的存續期間。 關鍵字:可轉換公司債、存續期間、有效存續期間、六元樹、Hull-white、利率模型 / Title of Thesis: Anatomy of the Convertible Bond Duration Name of Institute: Graduate Institute of Money and Banking, NCCU Graduate Date: June, 2002 Name of Student: Chen, Chia-Lin Advisor: Dr. Chen, Son-Nan Abstract: This thesis uses effective duration method to anatomize the convertible bond duration. With the assumptions that stock price follows Geometric Brownian Motion and risk-free interest rate follows Hull and White model, we built a hexanomial tree to value the convertible bond. This thesis analyses the effects of the six parameters . They are maturity date, the ratio of the stock price versus the strike price, the correlation between stock return and interest rate, stock return volatility, interest rate volatility, and coupons. The conclusions include nine points. First, the value of convertible bond duration including call clauses is higher then pure convertible bond duration. Second, the value of convertible bond duration including put clauses is lower than pure convertible bond duration. Third, the value of convertible bond duration including both call and put clauses is between only including call or put clauses ones. Fourth, the longer the time to maturity is, the higher the convertible bond duration is. Fifth, the higher the ratio of the strike price versus the stock price is , the higher the convertible bond duration is. Sixth, the higher the stock volatility is , the lower the convertible bond duration is. Seventh, the higher the interest rate volatility is , the higher the convertible bond duration is. Eighth, the value of the correlation between stock return and interest rate increases from a negative value to a positive one, then the convertible bond duration increases. Ninth, if the value of call right is very small , the convertible bond duration will increase by the increasing of the coupon . Keywords: Convertible Bond, Duration, Effective Duration, Hexanomial Tree, Hull and White Interest Rate Model
25

Fyziologická odezva závodníků lodní třídy Fireball při modelovém závodu v okruhovém jachtingu / Physiological response of competitors Fireball dinghy class in the model sailing race.

Lambl, David January 2012 (has links)
Title: Physiological response of competitors Fireball dinghy class in the model sailing race. Objectives: The main intention of the thesis is to detect the physical demands (difficulties) of sailing boat race categorized as Fireball double crew. The variables of physiological response to the load of competitors recorded are being measured using simulated race under laboratory conditions. At that point, this opportunity enabled us to carry out further comparisons and examine the physical demands of individual post at various directions of wind. Methods: The entire investigation of detecting physiological functions of competitors will be carried out noninvasively throughout the simulation of sailing using metabolic analyser tool and sport tester. From the feedback, we will obtained figures and originate the physiological response of human body to the load. Due to the investigation is being implemented on the double crew boat Fireball; both competitors (crew/helmsman) performing different tasks will be simulated and examined individually. Simulated race will last 24 minutes and competitors will have to face different wind courses, precisely cruising upwind, crosswind and tailwind. Results: From the measured results, we can state that most of the time during simulated race, the performance of racers...
26

Modelos flexíveis para dados de tempos de vida em um cenário de riscos competitivos e mecanismos de ativação latentes / Flexible models for data fifetime in a competing risk scenario and latente activation schemes

Delgado, José Julio Flores 26 May 2014 (has links)
Na literatura da área da análise de sobrevivência existem os modelos tradicionais, ou sem fração de cura, e os modelos de longa duração, ou com fração de cura. Recentemente tem sido proposto um modelo mais geral, conhecido como o modelo com fatores de risco latentes com esquemas de ativação. Nesta tese são deduzidas novas propriedades que possuem a função de sobrevivência, a função de taxa de risco e o valor esperado, quando e considerado o modelo com fatores de risco latentes. Estas propriedades são importantes, já que muitos outros modelos que tem aparecido na literatura recentemente podem ser considerados como casos particulares do modelo com fatores de risco latentes. Além disto, são propostos novos modelos de sobrevivência e estes são aplicados a conjuntos de dados reais. Também é realizado um estudo de simulação e uma análise de sensibilidade, para mostrar a qualidade destes modelos / In the survival literature we can find traditional models without cure fraction and longterm models with cure fraction. A more general risk factor model with latent activation scheme has been recently proposed. In this thesis we deduce new properties for the survival function, hazard function and expected value for this model. Since many recent survival models can be regarded as particular cases of the risk factor model with latent activation scheme these properties are of great relevance. In addition we propose new survival models that are applied to real data examples. A simulation and sensibility analysis are also performed to asses the goodness of fit of these models
27

在常微分方程下利用二次逼近法探討人口成長模型問題 / On the Parabola Approximation Method in Ordinary Differential Equation - Modelling Problem on The Population Growth

李育佐, Li,Yu Tso Unknown Date (has links)
在人口統計領域中,早期習慣將人口變化視為時間的函數,企圖以Deterministic Function來刻劃,例如:1798年Malthus提出的Malthusian Growth Model ;1825年Gompertz提出的Gompertz Model以及1838年Verhulst主張以Logistic Function描述人口成長。而近年來則是傾向於逐項分析各種因素的隨機性模型,例如:1983年Holford加入世代的APC模型;1992年Lee 和Carter提出的Lee-Carter死亡率模型以及2003年Renshaw與Haberman提出改善Lee-Carter死亡率模型的Reduction Factor模型。 人口變化主要分成自然增加與社會增加,而自然增加是為出生扣掉死亡,社會增加則為移入扣掉移出。首先,本文先不考慮遷移的部分,各別以出生與死亡人口的變化為研究對象,視其變化為一隨時間變動的動態系統,以常微分方程來刻劃。由台灣地區人口統計資料顯示,出生率或死亡率都有逐年下降的趨勢,而且隨著時間而變化加劇的傾向,使得以往使用的模型不易捕捉變化,因此我們提出「二次逼近法」,從出生、死亡人數對時間的變化率與曲度利用數值分析的方式來估計出生與死亡數,進而從中找出在此動態系統背後隱藏的規則。而後再同時考慮其他各種變項,以偏微分方程來刻劃,最後即可建立台灣地區人口變化模型。 / In early population statistics, the population changes were regarded as a function of time so that people tended to describe the variations by deterministic functions. For instance, Malthus proposed the Malthusian Growth Model in 1798; Gompertz presented Gompertz Model in 1825; Verhulst advocated using logistic function to describe an increase in population. In recent years, people tend to use the stochastic forecast method to analyse every factor term by term. For instance, the Age-Period-Cohort (APC) Model which was proposed by Holford in 1983; Lee and Carter proposed the Lee-Carter Mortality Model in 2003; and Renshaw and Haberman proposed the Reduction Factor Model in 2003 that improve the Lee-Carter Mortality Model. The population changes equal to nature and social increase, where the nature increase is the difference between birth and death population, and the social increase is the difference between immigrants and emigrants. First, we focus on natural increase rather than social increase. Moreover, we use ordinary differential equation to decribe the variation as a dynamic system over time. From the data obtained from the Ministry of Interior Taiwan, we know that the fertility and mortality has been decreasing, and the change is getting more violent year by year. Under the consideration that previous models are not able to accurately present the changes of birth and death, we proposed "second-order (or parabola) approximation method." From the variation rates and curvatures of birth and death population, we estimated the population size. Furthermore, we want to find the rule in the dynamic system. Later we will consider other factors simultaneously, and describe them by partial differential equation. Finally, the population model is constructed.
28

Modeling based on a reparameterized Birnbaum-Saunders distribution for analysis of survival data / Modelagem baseada na distribuição Birnbaum-Saunders reparametrizada para análise de dados de sobrevivência

Leão, Jeremias da Silva 09 January 2017 (has links)
Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-04-24T18:48:10Z No. of bitstreams: 1 TeseJSL.pdf: 1918523 bytes, checksum: 4d551d58b97032091209f65b7428e992 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-25T18:50:15Z (GMT) No. of bitstreams: 1 TeseJSL.pdf: 1918523 bytes, checksum: 4d551d58b97032091209f65b7428e992 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-04-25T18:50:23Z (GMT) No. of bitstreams: 1 TeseJSL.pdf: 1918523 bytes, checksum: 4d551d58b97032091209f65b7428e992 (MD5) / Made available in DSpace on 2017-04-25T18:59:25Z (GMT). No. of bitstreams: 1 TeseJSL.pdf: 1918523 bytes, checksum: 4d551d58b97032091209f65b7428e992 (MD5) Previous issue date: 2017-01-09 / Não recebi financiamento / In this thesis we propose models based on a reparameterized Birnbaum-Saunder (BS) distribution introduced by Santos-Neto et al. (2012) and Santos-Neto et al. (2014), to analyze survival data. Initially we introduce the Birnbaum-Saunders frailty model where we analyze the cases (i) with (ii) without covariates. Survival models with frailty are used when further information is nonavailable to explain the occurrence time of a medical event. The random effect is the “frailty”, which is introduced on the baseline hazard rate to control the unobservable heterogeneity of the patients. We use the maximum likelihood method to estimate the model parameters. We evaluate the performance of the estimators under different percentage of censured observations by a Monte Carlo study. Furthermore, we introduce a Birnbaum-Saunders regression frailty model where the maximum likelihood estimation of the model parameters with censored data as well as influence diagnostics for the new regression model are investigated. In the following we propose a cure rate Birnbaum-Saunders frailty model. An important advantage of this proposed model is the possibility to jointly consider the heterogeneity among patients by their frailties and the presence of a cured fraction of them. We consider likelihood-based methods to estimate the model parameters and to derive influence diagnostics for the model. In addition, we introduce a bivariate Birnbaum-Saunders distribution based on a parameterization of the Birnbaum-Saunders which has the mean as one of its parameters. We discuss the maximum likelihood estimation of the model parameters and show that these estimators can be obtained by solving non-linear equations. We then derive a regression model based on the proposed bivariate Birnbaum-Saunders distribution, which permits us to model data in their original scale. A simulation study is carried out to evaluate the performance of the maximum likelihood estimators. Finally, examples with real-data are performed to illustrate all the models proposed here. / Nesta tese propomos modelos baseados na distribuição Birnbaum-Saunders reparametrizada introduzida por Santos-Neto et al. (2012) e Santos-Neto et al. (2014), para análise dados de sobrevivência. Incialmente propomos o modelo de fragilidade Birnbaum-Saunders sem e com covariáveis observáveis. O modelo de fragilidade é caracterizado pela utilização de um efeito aleatório, ou seja, de uma variável aleatória não observável, que representa as informações que não podem ou não foram observadas tais como fatores ambientais ou genéticos, como também, informações que, por algum motivo, não foram consideradas no planejamento do estudo. O efeito aleatório (a “fragilidade”) é introduzido na função de risco de base para controlar a heterogeneidade não observável. Usamos o método de máxima verossimilhança para estimar os parâmetros do modelo. Avaliamos o desempenho dos estimadores sob diferentes percentuais de censura via estudo de simulações de Monte Carlo. Considerando variáveis regressoras, derivamos medidas de diagnóstico de influência. Os métodos de diagnóstico têm sido ferramentas importantes na análise de regressão para detectar anomalias, tais como quebra das pressuposições nos erros, presença de outliers e observações influentes. Em seguida propomos o modelo de fração de cura com fragilidade Birnbaum-Saunders. Os modelos para dados de sobrevivência com proporção de curados (também conhecidos como modelos de taxa de cura ou modelos de sobrevivência com longa duração) têm sido amplamente estudados. Uma vantagem importante do modelo proposto é a possibilidade de considerar conjuntamente a heterogeneidade entre os pacientes por suas fragilidades e a presença de uma fração curada. As estimativas dos parâmetros do modelo foram obtidas via máxima verossimilhança, medidas de influência e diagnóstico foram desenvolvidas para o modelo proposto. Por fim, avaliamos a distribuição bivariada Birnbaum-Saunders baseada na média, como também introduzimos um modelo de regressão para o modelo proposto. Utilizamos os métodos de máxima verossimilhança e método dos momentos modificados, para estimar os parâmetros do modelo. Avaliamos o desempenho dos estimadores via estudo de simulações de Monte Carlo. Aplicações a conjuntos de dados reais ilustram as potencialidades dos modelos abordados.
29

Recupera??o e purifica??o de quitosanases usando adsor??o em leito expandido com streamline DEAE com modelagem e simula??o usando redes neurais / Recovery and Purification of Chitosanases using Expanded Bed Adsorption with Streamline DEAE with Modeling and Simulation using Neural Networks

Padilha, Carlos Eduardo de Ara?jo 18 December 2013 (has links)
Made available in DSpace on 2014-12-17T15:01:34Z (GMT). No. of bitstreams: 1 CarlosEAP_DISSERT.pdf: 1904684 bytes, checksum: 4fd2147b17a381ad69d921436b5c83de (MD5) Previous issue date: 2013-12-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Expanded Bed Adsorption (EBA) is an integrative process that combines concepts of chromatography and fluidization of solids. The many parameters involved and their synergistic effects complicate the optimization of the process. Fortunately, some mathematical tools have been developed in order to guide the investigation of the EBA system. In this work the application of experimental design, phenomenological modeling and artificial neural networks (ANN) in understanding chitosanases adsorption on ion exchange resin Streamline? DEAE have been investigated. The strain Paenibacillus ehimensis NRRL B-23118 was used for chitosanase production. EBA experiments were carried out using a column of 2.6 cm inner diameter with 30.0 cm in height that was coupled to a peristaltic pump. At the bottom of the column there was a distributor of glass beads having a height of 3.0 cm. Assays for residence time distribution (RTD) revelead a high degree of mixing, however, the Richardson-Zaki coefficients showed that the column was on the threshold of stability. Isotherm models fitted the adsorption equilibrium data in the presence of lyotropic salts. The results of experiment design indicated that the ionic strength and superficial velocity are important to the recovery and purity of chitosanases. The molecular mass of the two chitosanases were approximately 23 kDa and 52 kDa as estimated by SDS-PAGE. The phenomenological modeling was aimed to describe the operations in batch and column chromatography. The simulations were performed in Microsoft Visual Studio. The kinetic rate constant model set to kinetic curves efficiently under conditions of initial enzyme activity 0.232, 0.142 e 0.079 UA/mL. The simulated breakthrough curves showed some differences with experimental data, especially regarding the slope. Sensitivity tests of the model on the surface velocity, axial dispersion and initial concentration showed agreement with the literature. The neural network was constructed in MATLAB and Neural Network Toolbox. The cross-validation was used to improve the ability of generalization. The parameters of ANN were improved to obtain the settings 6-6 (enzyme activity) and 9-6 (total protein), as well as tansig transfer function and Levenberg-Marquardt training algorithm. The neural Carlos Eduardo de Ara?jo Padilha dezembro/2013 9 networks simulations, including all the steps of cycle, showed good agreement with experimental data, with a correlation coefficient of approximately 0.974. The effects of input variables on profiles of the stages of loading, washing and elution were consistent with the literature / A adsor??o em leito expandido (ALE) ? uma t?cnica integrativa que alia conceitos de cromatografia e fluidiza??o de s?lidos. A diversidade de par?metros envolvidos e seus efeitos sinerg?ticos dificultam a tarefa de otimiza??o da opera??o. Felizmente, algumas ferramentas matem?ticas foram desenvolvidas de modo a direcionar as investiga??es do sistema ALE. Assim, o presente trabalho prop?e a aplica??o do planejamento experimental, modelagem fenomenol?gica e redes neurais artificiais (RNAs) na compreens?o da adsor??o de quitosanases na resina de troca i?nica Streamline? DEAE. A cepa Paenibacillus ehimensis NRRL B-23118 foi respons?vel pela produ??o das quitosanases. Nos ensaios de adsor??o usando o leito na forma expandida foi utilizada uma coluna de 2,6 cm de di?metro por 30,0 cm de altura, acoplada a uma bomba perist?ltica. Na base da coluna existia um distribuidor de microesferas de vidro com altura de 3,0 cm. Os ensaios de determina??o de tempo de resid?ncia (DTR) revelaram elevado grau de mistura, entretanto, os coeficientes de Richardson-Zaki mostraram que a coluna estava no limiar da estabilidade. Pelas regress?es das isotermas puderam-se ajustar os dados de equil?brio de adsor??o, na presen?a de diferentes sais da escala liotr?pica. O resultado do planejamento apontou que a for?a i?nica e a velocidade influenciam a recupera??o e pureza das quitosanases. As massas moleculares das duas esp?cies de quitosanases foram estimadas por SDS-PAGE, obtendo-se aproximadamente 23 kDa e 52 kDa. A modelagem fenomenol?gica foi direcionada para descrever as opera??es em batelada e na coluna cromatogr?fica. As simula??es foram executadas no Microsoft Visual Studio, usando a linguagem Fortran. O modelo de taxa constante ajustou-se ?s curvas cin?ticas com excel?ncia, nas condi??es de atividade iniciais 0,232, 0,142 e 0,079 UA/mL. As curvas de ruptura simuladas apresentaram algumas disparidades com os dados experimentais, principalmente quanto ? inclina??o. Os testes de sensibilidade do modelo sobre a velocidade superficial, dispers?o axial e concentra??o inicial mostraram conformidade com artigos publicados. A rede neural foi constru?da no ambiente MATLAB, por meio da Neural Network Toolbox. A valida??o cruzada foi usada para melhorar a capacidade de generaliza??o. Carlos Eduardo de Ara?jo Padilha dezembro/2013 6 Aperfei?oaram-se os par?metros da RNA at? se obter as configura??es 6-6 (atividade enzim?tica) e 9-6 (prote?nas totais), fun??o de ativa??o tansig e algoritmo de treinamento Levenberg-Marquardt. As simula??es da rede neural, incluindo todo o ciclo da opera??o, mostraram boa concord?ncia com os dados experimentais, com coeficiente de correla??o da ordem de 0,974. Os efeitos das vari?veis de entrada sobre os perfis das etapas de carga, lavagem e elui??o foram compat?veis com a literatura
30

Modelos flexíveis para dados de tempos de vida em um cenário de riscos competitivos e mecanismos de ativação latentes / Flexible models for data fifetime in a competing risk scenario and latente activation schemes

José Julio Flores Delgado 26 May 2014 (has links)
Na literatura da área da análise de sobrevivência existem os modelos tradicionais, ou sem fração de cura, e os modelos de longa duração, ou com fração de cura. Recentemente tem sido proposto um modelo mais geral, conhecido como o modelo com fatores de risco latentes com esquemas de ativação. Nesta tese são deduzidas novas propriedades que possuem a função de sobrevivência, a função de taxa de risco e o valor esperado, quando e considerado o modelo com fatores de risco latentes. Estas propriedades são importantes, já que muitos outros modelos que tem aparecido na literatura recentemente podem ser considerados como casos particulares do modelo com fatores de risco latentes. Além disto, são propostos novos modelos de sobrevivência e estes são aplicados a conjuntos de dados reais. Também é realizado um estudo de simulação e uma análise de sensibilidade, para mostrar a qualidade destes modelos / In the survival literature we can find traditional models without cure fraction and longterm models with cure fraction. A more general risk factor model with latent activation scheme has been recently proposed. In this thesis we deduce new properties for the survival function, hazard function and expected value for this model. Since many recent survival models can be regarded as particular cases of the risk factor model with latent activation scheme these properties are of great relevance. In addition we propose new survival models that are applied to real data examples. A simulation and sensibility analysis are also performed to asses the goodness of fit of these models

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