Relevant bibliographies by topics / Survival analysis (Biometry) / Dissertations / Theses
To see the other types of publications on this topic, follow the link: Survival analysis (Biometry).

Dissertations / Theses on the topic 'Survival analysis (Biometry)'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 August 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 dissertations / theses for your research on the topic 'Survival analysis (Biometry).'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.

1

Wardak, Mohammad Alif. "Survival analysis." CSUSB ScholarWorks, 2005. https://scholarworks.lib.csusb.edu/etd-project/2810.

Full text
Abstract:
Survival analysis pertains to a statistical approach designed to take into account the amount of time an experimental unit contributes to a study. A Mayo Clinic study of 418 Primary Biliary Cirrhosis patients during a ten year period was used. The Kaplan-Meier Estimator, a non-parametric statistic, and the Cox Proportional Hazard methods were the tools applied. Kaplan-Meier results include total values/censored values.
APA, Harvard, Vancouver, ISO, and other styles
2

葉英傑 and Ying-Kit David Ip. "Analysis of clustered grouped survival data." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31226127.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Ip, Ying-Kit David. "Analysis of clustered grouped survival data /." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2353011x.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

林國輝 and Kwok-fai Lam. "Topics in survival analysis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B30408994.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Lam, Kwok-fai. "Topics in survival analysis /." Hong Kong : University of Hong Kong, 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13829919.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Zhang, Xinjian. "HIV/AIDS relative survival analysis." unrestricted, 2007. http://etd.gsu.edu/theses/available/etd-07262007-123251/.

Full text
Abstract:
Thesis (M.S.)--Georgia State University, 2007.
Title from file title page. Gengsheng (Jeff) Qin, committee chair; Ruiguang (Rick) Song, Xu Zhang, Yu-Sheng Hsu, committee members. Electronic text (79 p. : col. ill.) : digital, PDF file. Description based on contents viewed Sept. 16, 2008. Includes bibliographical references (p. 38-42).
APA, Harvard, Vancouver, ISO, and other styles
7

Wong, Chun-mei May. "Multilevel models for survival analysis in dental research." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B3637216X.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Zhou, Feifei, and 周飞飞. "Cure models for univariate and multivariate survival data." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B45700977.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Lee, Yau-wing. "Modelling multivariate survival data using semiparametric models." Click to view the E-thesis via HKUTO, 2000. http://sunzi.lib.hku.hk/hkuto/record/B4257528X.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

梁翠蓮 and Tsui-lin Leung. "Proportional odds model for survival data." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B42575011.

Full text
APA, Harvard, Vancouver, ISO, and other styles
11

Leung, Tsui-lin. "Proportional odds model for survival data." Click to view the E-thesis via HKUTO, 1999. http://sunzi.lib.hku.hk/hkuto/record/B42575011.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Volinsky, Christopher T. "Bayesian model averaging for censored survival models /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/8944.

Full text
APA, Harvard, Vancouver, ISO, and other styles
13

Jubane, Ido. "A simulation study of the behaviour of the logrank test under different levels of stratification and sample sizes." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1018558.

Full text
Abstract:
In clinical trials, patients are enrolled into two treatment arms. A researcher may be interested in studying the effectiveness of a new drug or the comparison of two drugs for the treatment of a disease. This survival data is later analysed using the logrank test or the Cox regression model to detect differences in survivor functions. However, the power function of the logrank test depends solely on the number of patients enrolled into the study. Because statisticians will always minimise type I and type II errors, a researcher carrying out a clinical trial must define beforehand, the number of patients to be enrolled into the clinical study. Without proper sample size and power estimation a clinical trial may fail to detect a false hypothesis of the equality of survivor functions. This study presents through simulation, a way of power and sample size estimation for clinical trials that use the logrank test for their data analysis and suggests an easy method to estimate power and sample size in such clinical studies. Findings on power analysis and sample size estimation on logrank test are applied to two real examples: one is the Veterans' Administration Lung Cancer study; and the other is the data from a placebo controlled trial of gamma interferon in chronic granulotomous disease.
APA, Harvard, Vancouver, ISO, and other styles
14

Fan, Juanjuan. "Dependency estimation over a finite bivariate failure time region /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/9548.

Full text
APA, Harvard, Vancouver, ISO, and other styles
15

Lam, Chung-sang. "Survival analysis of the timing of goals in soccer games." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B32028635.

Full text
APA, Harvard, Vancouver, ISO, and other styles
16

Zhang, Zhigang. "Nonproportional hazards regression models for survival analysis /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p3144473.

Full text
APA, Harvard, Vancouver, ISO, and other styles
17

Wong, Chun-mei May, and 王春美. "Multilevel models for survival analysis in dental research." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B3637216X.

Full text
APA, Harvard, Vancouver, ISO, and other styles
18

Louw, Elizabeth Magrietha. "Fitting of survival functions for grouped data on insurance policies." Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-11282005-123928.

Full text
APA, Harvard, Vancouver, ISO, and other styles
19

Long, Yongxian, and 龙泳先. "Semiparametric analysis of interval censored survival data." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45541152.

Full text
APA, Harvard, Vancouver, ISO, and other styles
20

Puza, Borek Dalibor. "Aspects of Bayesian biostatistics." Thesis, Canberra, ACT : The Australian National University, 1994. http://hdl.handle.net/1885/140911.

Full text
APA, Harvard, Vancouver, ISO, and other styles
21

李友榮 and Yau-wing Lee. "Modelling multivariate survival data using semiparametric models." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B4257528X.

Full text
APA, Harvard, Vancouver, ISO, and other styles
22

Liu, Fei, and 劉飛. "Statistical inference for banding data." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2008. http://hub.hku.hk/bib/B41508701.

Full text
APA, Harvard, Vancouver, ISO, and other styles
23

Liu, Fei. "Statistical inference for banding data." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41508701.

Full text
APA, Harvard, Vancouver, ISO, and other styles
24

Lai, Xin. "Extensions on long-term survivor model with random effects /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ms-b3008233xf.pdf.

Full text
Abstract:
Thesis (Ph.D.)--City University of Hong Kong, 2009.
"Submitted to Department of Management Sciences in partial fulfillment of the requirement for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 118-126)
APA, Harvard, Vancouver, ISO, and other styles
25

Lam, Chung-sang, and 林仲生. "Survival analysis of the timing of goals in soccer games." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B32028635.

Full text
APA, Harvard, Vancouver, ISO, and other styles
26

Louw, Elizabeth Magrietha. "Fitting of survival functions for grouped data on insurance policies." Diss., University of Pretoria, 2002. http://hdl.handle.net/2263/29891.

Full text
Abstract:
The aim of the research is the statistical modelling of parametric survival distributions of grouped survival data of long- and shortterm policies in the insurance industry, by means of a method of maximum likelihood estimation subject to constraints. This methodology leads to explicit expressions for the estimates of the parameters, as well as for approximated variances and covariances of the estimates, which gives exact maximum likelihood estimates of the parameters. This makes direct extension to more complex designs feasible. The statistical modelling offers parametric models for survival distributions, in contrast with non-parametric models that are used commonly in the actuarial profession. When the parametric models provide a good fit to data, they tend to give more precise estimates of the quantities of interest such as odds ratios, hazard ratios or median lifetimes. These estimates form the statistical foundation for scientific decisionmaking with respect to actuarial design, maintenance and marketing of insurance policies. Although the methodology in this thesis is developed specifically for the insurance industry, it may be applied in the normal context of research and scientific decision making, that includes for example survival distributions for the medical, biological, engineering, econometric and sociological sciences.
Dissertation (PhD (Mathematical Statistics))--University of Pretoria, 2002.
Mathematics and Applied Mathematics
unrestricted
APA, Harvard, Vancouver, ISO, and other styles
27

Shinohara, Russell. "Estimation of survival of left truncated and right censored data under increasing hazard." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100210.

Full text
Abstract:
When subjects are recruited through a cross-sectional survey they have already experienced the initiation of the event of interest, say the onset of a disease. This method of recruitment results in the fact that subjects with longer duration of the disease have a higher chance of being selected. It follows that censoring in such a case is not non-informative. The application of standard techniques for right-censored data thus introduces a bias to the analysis; this is referred to as length-bias. This paper examines the case where the subjects are assumed to enter the study at a uniform rate, allowing for the analysis in a more efficient unconditional manner. In particular, a new method for unconditional analysis is developed based on the framework of a conditional estimator. This new method is then applied to the several data sets and compared with the conditional technique of Tsai [23].
APA, Harvard, Vancouver, ISO, and other styles
28

Lim, Hee-Jeong. "Statistical analysis of interval-censored and truncated survival data /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3025635.

Full text
APA, Harvard, Vancouver, ISO, and other styles
29

Wong, Kin-yau, and 黃堅祐. "Analysis of interval-censored failure time data with long-term survivors." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48199473.

Full text
Abstract:
Failure time data analysis, or survival analysis, is involved in various research fields, such as medicine and public health. One basic assumption in standard survival analysis is that every individual in the study population will eventually experience the event of interest. However, this assumption is usually violated in practice, for example when the variable of interest is the time to relapse of a curable disease resulting in the existence of long-term survivors. Also, presence of unobservable risk factors in the group of susceptible individuals may introduce heterogeneity to the population, which is not properly addressed in standard survival models. Moreover, the individuals in the population may be grouped in clusters, where there are associations among observations from a cluster. There are methodologies in the literature to address each of these problems, but there is yet no natural and satisfactory way to accommodate the coexistence of a non-susceptible group and the heterogeneity in the susceptible group under a univariate setting. Also, various kinds of associations among survival data with a cure are not properly accommodated. To address the above-mentioned problems, a class of models is introduced to model univariate and multivariate data with long-term survivors. A semiparametric cure model for univariate failure time data with long-term survivors is introduced. It accommodates a proportion of non-susceptible individuals and the heterogeneity in the susceptible group using a compound- Poisson distributed random effect term, which is commonly called a frailty. It is a frailty-Cox model which does not place any parametric assumption on the baseline hazard function. An estimation method using multiple imputation is proposed for right-censored data, and the method is naturally extended to accommodate interval-censored data. The univariate cure model is extended to a multivariate setting by introducing correlations among the compound- Poisson frailties for individuals from the same cluster. This multivariate cure model is similar to a shared frailty model where the degree of association among each pair of observations in a cluster is the same. The model is further extended to accommodate repeated measurements from a single individual leading to serially correlated observations. Similar estimation methods using multiple imputation are developed for the multivariate models. The univariate model is applied to a breast cancer data and the multivariate models are applied to the hypobaric decompression sickness data from National Aeronautics and Space Administration, although the methodologies are applicable to a wide range of data sets.
published_or_final_version
Statistics and Actuarial Science
Master
Master of Philosophy
APA, Harvard, Vancouver, ISO, and other styles
30

Tang, On-yee. "Estimation for generalized linear mixed model via multiple imputations." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B30687652.

Full text
APA, Harvard, Vancouver, ISO, and other styles
31

Tang, On-yee, and 鄧安怡. "Estimation for generalized linear mixed model via multipleimputations." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B30687652.

Full text
APA, Harvard, Vancouver, ISO, and other styles
32

Baade, Ingrid Annette. "Survival analysis diagnostics." Thesis, Queensland University of Technology, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
33

Cheung, Tak-lun Alan, and 張德麟. "Modelling multivariate interval-censored and left-truncated survival data using proportional hazards model." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29536637.

Full text
APA, Harvard, Vancouver, ISO, and other styles
34

Wang, Pei-Yu, and n/a. "Novel survival factors with a gender specific twist for motor neurons." University of Otago. Department of Anatomy & Structural Biology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070504.143741.

Full text
Abstract:
The survival of motor neurons is controlled by multiple factors, which regulate different aspects of their physiology. The identification of these factors is important because of their relevance for motor neuron disease. This thesis began with a search for novel growth factors that naturally keep these neurons alive. Members of the TGF-β superfamily, including Mullerian inhibiting substance (MIS) and bone morphogenetic protein 6 (BMP6), were identified as putative survival factors following a cDNA microarray analysis of a mouse model of motor neuron disease. MIS is a gonad-derived hormone with a male bias. It induces the degeneration of the female reproductive tract during development and it was thought to have no physiological function outside of the reproductive system. In this thesis, multiple techniques were used to show that adult motor neurons produce MIS and its receptors. The copy number of MIS mRNA in motor neurons was comparable with that of the testis, whereas the mRNA of the MIS type II receptor (MISRII) in motor neurons appeared to be the most abundant receptor of the TGF-β superfamily. These results were confirmed using Western blot and immunohistochemistry. Thus, MIS may exert its function through an autocrine or a paracrine mechanism between neighbouring motor neurons. The function of MIS was examined using a culture system and a mouse null mutation of MISRII. The in vitro assays showed strong neurotrophic effects of MIS on embryonic motor neurons with the maximum extent of survival being similar to that achieved by the classical motor neuron survival factor, GDNF. MIS has a male bias in utero raising the issue of whether motor neurons are sexually dimorphic. Consistent with this, the number of motor neurons in the lumbar lateral motor column of neonatal male MISRII+/+ mice was 13 % greater than in female mice (P = 0.01). The nuclei of male motor neurons were approximately 20 % larger than their female counterparts (P = 0.000). MISRII-/- male mice had 18 % fewer motor neurons than wild-type males (P = 0.01) and the mean size of their motor neurons was 20 % smaller (P = 0.000). The number and size of motor neurons in the MISRII-/- males was not different to those of MISRII+/+ females. These results implicate MIS as being responsible for neuronal survival as well as producing sexual dimorphism of the limb innervating motor neurons. Since MIS does not appear to be expressed in the embryonic neuromuscular system, it is postulated that MIS is a gonad-derived neurotrophic factor for developing motor neurons. The BMP type II receptor (BMPRII) was the second most abundant receptor of the TGF-β superfamily expressed by motor neurons. One of its ligands, BMP6, was found to have a neurotrophic effect on motor neurons in culture but was slightly less potent than MIS. BMP6 mRNA was detected in nerve, skeletal muscle and spinal cord, but not in motor neurons. BMP6 immunoreactivity was mainly associated with the myelinated Schwann cells and satellite glia that surround motor neurons. In skeletal muscles, immunoreactivity was not detected in muscle fibers, nor the postsynaptic region of the neuromuscular junction (NMJ). BMP6 was, however, associated with the interstitial cells of skeletal muscles. Double nerve ligations were used to examine whether Schwann cell-derived BMP6 interacts with motor neurons. Consistent with this, BMP6 was retrogradely transported in motor axons. These observations collectively suggest that BMP6 is a glia-derived regulator of motor neurons. MIS and minority of BMP6 were anterogradely transported towards the NMJ. Their receptors, MISRII and BMPRII, were detected in the postsynaptic portions of the adult NMJ. These observations raised the possibility that MIS and BMP6 may be regulators of the adult NMJ. Since functional redundancy amongst the members of the TGF-β superfamily has been suggested, the function of MIS/BMP6 signaling at the NMJ was therefore examined in mice with muscle-specific deletion of Smad4, a central mediator of TGF-β superfamily pathways. More than 75% of animals lacking Smad4 in muscles died before embryonic day (E) 14 and none survived postnally. This was due to the loss of functional Smad4 in developing cardiac myocytes, which resulted in severe heart defects and early death of embryos. Thus, the function of MIS/BMP6 signaling at the adult NMJ could not be studied. Finally, this thesis briefly examined the phenotypes of mice carrying double null mutations of MISRII and TGF-β2. The animals died at an early stage and showed a more severe phenotype than either of the single null mutants. This suggests that functional redundancy among members of the TGF-β superfamily exists in many organs. In summary, motor neurons require multiple sources of growth factors for their survival. MIS and BMP6 were discovered as novel survival factors for motor neurons in this study. MIS was implicated as a regulator of sexual dimorphism in developing motor neurons, whereas both MIS and BMP6 appear to regulate mature motor neurons, and possibly the NMJ.
APA, Harvard, Vancouver, ISO, and other styles
35

Fang, Jing. "On testing for the Cox model using resampling methods." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/HKUTO/record/B39558356.

Full text
APA, Harvard, Vancouver, ISO, and other styles
36

Fang, Jing, and 方婧. "On testing for the Cox model using resampling methods." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39558356.

Full text
APA, Harvard, Vancouver, ISO, and other styles
37

Kim, Seong W. "Bayesian model selection using intrinsic priors for commonly used models in reliability and survival analysis /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841159.

Full text
APA, Harvard, Vancouver, ISO, and other styles
38

Lee, Gunhee. "Noninformative priors for some models useful in reliability and survival analysis /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9720544.

Full text
APA, Harvard, Vancouver, ISO, and other styles
39

Thompson, Nicola Dawn. "Survival time from diagnosis of candidemia an application of survival methods for epidemiology to the Mycoses Study Group multi-center observational study of hospitalized patients with candidemia /." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117558533.

Full text
Abstract:
Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xi, 108 p.; also includes graphics (some col.) Includes bibliographical references (p. 101-108). Available online via OhioLINK's ETD Center
APA, Harvard, Vancouver, ISO, and other styles
40

Hata, Milene Elissa [UNESP]. "Aplicação de análise de sobrevivência no estudo da imobilidade tônica e do comportamento de reintegração social de perdizes (Rhynchotus rufescens)." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/110556.

Full text
Abstract:
Made available in DSpace on 2014-11-10T11:09:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-17Bitstream added on 2014-11-10T11:57:53Z : No. of bitstreams: 1 000791484_20160101.pdf: 43333 bytes, checksum: 262a2698faeadb4cab4b7a3171811cc2 (MD5) Bitstreams deleted on 2016-01-04T10:26:17Z: 000791484_20160101.pdf,. Added 1 bitstream(s) on 2016-01-04T10:28:12Z : No. of bitstreams: 1 000791484.pdf: 1660378 bytes, checksum: 1b1612c5e778466cf417d45fd83990a4 (MD5)
O estudo dos comportamentos de imobilidade tônica (IT) e de reintegração social (CRS) pode revelar as interações homem-animal e animalanimal, refletindo no bem-estar dos animais no ambiente de cativeiro, acarretando, assim, em respostas positivas ou negativas para a produção e lucratividade do sistema de criação. Visando entender o nível de medo e a manifestação de sociabilidade em perdizes (Rhynchotus rufescens), a metodologia de análise de sobrevivência foi utilizada para estimar o tempo de permanência em IT e o tempo transcorrido para um animal se unir com seu conspecífico. Para isto, perdizes criadas no Setor de Animais Silvestres - FCAV - Unesp submetidas às avaliações de IT e de CRS, no período de 2006 a 2010, foram utilizadas. As observações de IT foram realizadas em 539 aves e os resultados revelaram que os efeitos de ano de nascimento, mês e peso corporal da ave na época da medida de IT foram importantes fontes de variação na duração do tempo em catatonia. Além disso, aves com maior peso corporal tenderam a permanecer maior tempo em IT. Observações de CRS realizados em 503 aves mostraram que as mais velhas levaram mais tempo para unir-se ao conspecífico. O efeito aleatório de pai foi significativo (p < 0,05) para IT e a herdabilidade estimada (h2) empregando-se o software Survival Kit foi igual a 0,37. A h2 para CRS foi 0,31, entretanto supõe-se alto erro-padrão associado a esta estimativa devido ao efeito aleatório de pai não ter sido significativo (p < 0,05). A correlação entre os valores genéticos de IT e de CRS foi 0,0598 (p = 0,1491), evidenciando a inexistência de genes de efeito aditivo comuns entre estes dois comportamentos na população analisada. É possível aplicar a seleção nas aves para diminuir o tempo de permanência em IT, sem alterar o nível de socialização
The study of tonic immobility (TI) and social reinstatement behavior (SRB) can reveal interactions between man-animal and animal-animal. Those interactions reflect on the welfare of captive animals and may result in positively or negatively effects on the production and profitability of production system. Aiming at understanding the level of fear and the manifestation of sociability in red-winged tinamou (Rhynchotus rufescens), the survival analysis was applied to estimate the time in TI and also the time expent to an animal join with its conspecific. For this, redwinged tinamous reared in the Setor de Animais Silvestres – FCAV – Unesp hatched from 2006 to 2010 underwent TI and SRB evaluations. The observations of TI were performed in 539 birds and the results revealed that the effects of year of birth, month, and body weight of the bird at the time the measure of TI were important sources of variation for the time in catatonia; furthermore, birds with higher body weight tended to remain longer in TI. The SRB observations made in 503 birds showed that the older birds spent more time then the younger to join with their conspecific. The random effect of sire was significant (p < 0.05) for TI and the estimated heritability (h2) by Survival Kit software was equal to 0.37. The h2 for SRB was 0.31, however the estimate is supposed to have a high standard error associated with due to the random effect of sire being not significant. The correlation between the predicted breeding values of TI and SRB was 0.0598 (p = 0.1491), evidencing the non existence of common additive genes between these two traits in the studied population. Therefore, selection to decrease the time in TI could be applied on TI, without changing the level of socialization in this population
APA, Harvard, Vancouver, ISO, and other styles
41

Novaes, Edimar Izidoro [UNESP]. "Análise do uso das águas de uma empresa do ramo petroquímico via análise de sobrevivência." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/124115.

Full text
Abstract:
Made available in DSpace on 2015-06-17T19:34:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-11-19. Added 1 bitstream(s) on 2015-06-18T12:46:56Z : No. of bitstreams: 1 000831297.pdf: 830613 bytes, checksum: fa1703f2831e3d6345b6288ab0e519ff (MD5)
Na literatura é discutido o uso de planárias como bioindicadores de qualidade das águas, pois diferentes dos ensaios de toxicologia clássica, os animais conseguem captar efeitos de exposição a longo prazo. Atualmente, uma das técnicas de se verificar a qualidade das águas com o uso de planárias é realizando o teste cometa. Propomos uma forma alternativa para verificar a qualidade das águas utilizando planárias, a qual consiste em acompanhar o tempo de vida das mesmas inseridas em diferentes ambientes aquáticos. No estudo presente foram utilizados os dados obtidos por uma empresa que atua no ramo petroquímico e que utiliza as águas do rio Jaguari em seu processo de produção, nos quais foram aplicadas as técnicas estatísticas de análise de sobrevivência para comparar os níveis de poluentes tóxicos nos diferentes ambientes aquáticos. Também propomos um modelo de regressão para realizar inferências nos tempos de vida das planárias para os diferentes locais dos quais foram coletadas as amostras de água. O novo método proposto apresentou uma forma eficiente e de baixo custo no uso das planárias da espécie Dugesia Tigrina como bioindicadores de qualidade de águas.
In literature the use of planarians as bioindicators of water quality is discussed, because differently from classic toxicology tests, the animals are able to capture long term exposition effects. Currently, one of techniques to verify the water quality with the use of planarians is performing the comet assay. We propose a new alternative to verify the water quality by accompany lifetime planarians on different aquatic environments. In the present study we used data obtained from a petrochemical company that uses Jaguari river on its production process. Survival Analysis was used to compare the levels of toxic pollutants on different aquatic environments. We also propose a regression model to make inference in the lifetimes of planarians for the different locations from which water samples were collected. The new proposed method presented an efficient and low cost way to use planarians of Dugesia Tigrina specie as water quality bioindicators
APA, Harvard, Vancouver, ISO, and other styles
42

Novaes, Edimar Izidoro. "Análise do uso das águas de uma empresa do ramo petroquímico via análise de sobrevivência /." Botucatu, 2014. http://hdl.handle.net/11449/124115.

Full text
Abstract:
Orientador: Miriam harumi Tsunemi
Banca: Luciana Vaz de Arruda Silveira
Banca: Diogo Francisco Rossoni
Resumo: Na literatura é discutido o uso de planárias como bioindicadores de qualidade das águas, pois diferentes dos ensaios de toxicologia clássica, os animais conseguem captar efeitos de exposição a longo prazo. Atualmente, uma das técnicas de se verificar a qualidade das águas com o uso de planárias é realizando o teste cometa. Propomos uma forma alternativa para verificar a qualidade das águas utilizando planárias, a qual consiste em acompanhar o tempo de vida das mesmas inseridas em diferentes ambientes aquáticos. No estudo presente foram utilizados os dados obtidos por uma empresa que atua no ramo petroquímico e que utiliza as águas do rio Jaguari em seu processo de produção, nos quais foram aplicadas as técnicas estatísticas de análise de sobrevivência para comparar os níveis de poluentes tóxicos nos diferentes ambientes aquáticos. Também propomos um modelo de regressão para realizar inferências nos tempos de vida das planárias para os diferentes locais dos quais foram coletadas as amostras de água. O novo método proposto apresentou uma forma eficiente e de baixo custo no uso das planárias da espécie Dugesia Tigrina como bioindicadores de qualidade de águas.
Abstract: In literature the use of planarians as bioindicators of water quality is discussed, because differently from classic toxicology tests, the animals are able to capture long term exposition effects. Currently, one of techniques to verify the water quality with the use of planarians is performing the comet assay. We propose a new alternative to verify the water quality by accompany lifetime planarians on different aquatic environments. In the present study we used data obtained from a petrochemical company that uses Jaguari river on its production process. Survival Analysis was used to compare the levels of toxic pollutants on different aquatic environments. We also propose a regression model to make inference in the lifetimes of planarians for the different locations from which water samples were collected. The new proposed method presented an efficient and low cost way to use planarians of Dugesia Tigrina specie as water quality bioindicators
Mestre
APA, Harvard, Vancouver, ISO, and other styles
43

Hata, Milene Elissa. "Aplicação de análise de sobrevivência no estudo da imobilidade tônica e do comportamento de reintegração social de perdizes (Rhynchotus rufescens) /." Jaboticabal, 2014. http://hdl.handle.net/11449/110556.

Full text
Abstract:
Orientador: Sandra Aidar de Queiroz
Coorientador: Sabrina Luzia Caetano
Banca: Janaina Della Torre da Silva
Banca: Patricia Tholon
Banca: Danísio Prado Munari
Banca: Isabel Cristina Boreli
Resumo: O estudo dos comportamentos de imobilidade tônica (IT) e de reintegração social (CRS) pode revelar as interações homem-animal e animalanimal, refletindo no bem-estar dos animais no ambiente de cativeiro, acarretando, assim, em respostas positivas ou negativas para a produção e lucratividade do sistema de criação. Visando entender o nível de medo e a manifestação de sociabilidade em perdizes (Rhynchotus rufescens), a metodologia de análise de sobrevivência foi utilizada para estimar o tempo de permanência em IT e o tempo transcorrido para um animal se unir com seu conspecífico. Para isto, perdizes criadas no Setor de Animais Silvestres - FCAV - Unesp submetidas às avaliações de IT e de CRS, no período de 2006 a 2010, foram utilizadas. As observações de IT foram realizadas em 539 aves e os resultados revelaram que os efeitos de ano de nascimento, mês e peso corporal da ave na época da medida de IT foram importantes fontes de variação na duração do tempo em catatonia. Além disso, aves com maior peso corporal tenderam a permanecer maior tempo em IT. Observações de CRS realizados em 503 aves mostraram que as mais velhas levaram mais tempo para unir-se ao conspecífico. O efeito aleatório de pai foi significativo (p < 0,05) para IT e a herdabilidade estimada (h2) empregando-se o software Survival Kit foi igual a 0,37. A h2 para CRS foi 0,31, entretanto supõe-se alto erro-padrão associado a esta estimativa devido ao efeito aleatório de pai não ter sido significativo (p < 0,05). A correlação entre os valores genéticos de IT e de CRS foi 0,0598 (p = 0,1491), evidenciando a inexistência de genes de efeito aditivo comuns entre estes dois comportamentos na população analisada. É possível aplicar a seleção nas aves para diminuir o tempo de permanência em IT, sem alterar o nível de socialização
Abstract: The study of tonic immobility (TI) and social reinstatement behavior (SRB) can reveal interactions between man-animal and animal-animal. Those interactions reflect on the welfare of captive animals and may result in positively or negatively effects on the production and profitability of production system. Aiming at understanding the level of fear and the manifestation of sociability in red-winged tinamou (Rhynchotus rufescens), the survival analysis was applied to estimate the time in TI and also the time expent to an animal join with its conspecific. For this, redwinged tinamous reared in the Setor de Animais Silvestres - FCAV - Unesp hatched from 2006 to 2010 underwent TI and SRB evaluations. The observations of TI were performed in 539 birds and the results revealed that the effects of year of birth, month, and body weight of the bird at the time the measure of TI were important sources of variation for the time in catatonia; furthermore, birds with higher body weight tended to remain longer in TI. The SRB observations made in 503 birds showed that the older birds spent more time then the younger to join with their conspecific. The random effect of sire was significant (p < 0.05) for TI and the estimated heritability (h2) by Survival Kit software was equal to 0.37. The h2 for SRB was 0.31, however the estimate is supposed to have a high standard error associated with due to the random effect of sire being not significant. The correlation between the predicted breeding values of TI and SRB was 0.0598 (p = 0.1491), evidencing the non existence of common additive genes between these two traits in the studied population. Therefore, selection to decrease the time in TI could be applied on TI, without changing the level of socialization in this population
Doutor
APA, Harvard, Vancouver, ISO, and other styles
44

Layton, Danielle Maree. "Indexing, reporting and identification of time-to-event survival analyses in the dental literature." Thesis, University of Oxford, 2015. http://ora.ox.ac.uk/objects/uuid:46b35968-ceda-4a50-bc7b-878743efd000.

Full text
Abstract:
Objective: This research explored how time-to-event dental articles were indexed and reported, and sought solutions to help improve the reporting and identification of these articles, so that they could be more easily found and used to inform practice and research. Methods: Articles reporting time-to-event dental outcomes in humans were identified from the 50 dental journals with the highest impact factor for 2008. These were handsearched, identifying 'case' articles (n=95), active controls (likely false positives, n=91), and passive controls (other true negatives, n=6796). The medical subject headings (MESH) that had been assigned to the articles in MEDLINE, and words used in titles and abstracts describing time-to-events were compared between the 'cases' and controls. Time-to-event words and figures within articles were also sought, and reporting quality was assessed. Search strategies to identify time-toevent articles were developed, using indexing terms and free-text words. An independent cohort of articles was used to validate the search strategies, consisting of 148 time-to-event articles handsearched from 6514 articles in the 50 dental journals with the highest impact factor for 2012. The findings of the research were used to draft guidance to improve reporting, which was circulated amongst 78 stakeholder experts for comment, and modified. Results: MeSH indexing of time-to-event analyses was inconsistent and inaccurate, author descriptions in abstracts and titles varied, and the quality of time-to-event reporting and graphics in the body of those articles was poor. The burden faced by someone wishing to find and use these articles was considered high. Sensitive, precise and optimized electronic search strategies were developed and validated with sensitivities up to 92% and precisions up to 93%. The draft guidance attracted comment from 46 experts across 15 countries, with approximately 90% of the 130 comments accepted into the revised version. The importance of good quality reporting was endorsed, and there was high interest in commending the guidance to authors, reviewers, and training dental specialists. Conclusions: This research programme explored how time-to-event dental articles were reported, and used those findings to suggest solutions that would help to improve the identification and use of these data, reducing research waste.
APA, Harvard, Vancouver, ISO, and other styles
45

Akcin, Haci Mustafa. "Direct adjustment method on Aalen's additive hazards model for competing risks data." unrestricted, 2008. http://etd.gsu.edu/theses/available/etd-04182008-095207/.

Full text
Abstract:
Thesis (M.S.)--Georgia State University, 2008.
Title from file title page. Xu Zhang, committee chair; Yichuan Zhao, Jiawei Liu, Yu-Sheng Hsu, committee members. Electronic text (51 p.) : digital, PDF file. Description based on contents viewed July 15, 2008. Includes bibliographical references (p. 50-51).
APA, Harvard, Vancouver, ISO, and other styles
46

Argenton, Juliana Luz Passos 1984. "Árvore de regressão para dados censurados e correlacionados." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/307181.

Full text
Abstract:
Orientador: Hildete Prisco Pinheiro
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica
Made available in DSpace on 2018-08-24T02:10:38Z (GMT). No. of bitstreams: 1 Argenton_JulianaLuzPassos_M.pdf: 2087574 bytes, checksum: b6014c3478501f5128fd13ddf952e6dd (MD5) Previous issue date: 2013
Resumo: O objetivo deste trabalho é apresentar uma metodologia de árvore de regressão para dados censurados e correlacionados. O conjunto de dados analisado foi obtido a partir de uma pesquisa realizada entre Dezembro de 2005 e Janeiro de 2006, que entrevistou 119 famílias (1712 indivíduos) que vivem no pequeno vilarejo de Baependi, no Estado de Minas Gerais. São apresentadas duas metodologias com base no modelo de riscos proporcionais, a primeira desconsidera a possível correlação existente entre os indivíduos de uma mesma família e usa a primeira iteração da estimativa da verossimilhança completa nas divisões dos nós. Na segunda metodologia apresentada, a correlação entre os indivíduos de uma mesma família é incorporada no modelo de riscos proporcionais através de uma variável de fragilidade com distribuição Gama, neste caso o valor da estatística Escore é usado para escolher a melhor divisão dos nós. O objetivo da análise é avaliar as variáveis que aumentam o risco de apresentar hipertensão, diabetes tipo II e colesterol alto, que são os três principais fatores que aumentam o risco de doenças no coração. As variáveis respostas são as idades de diagnóstico desses fatores de risco. A censura é definida de acordo com a observação da idade do indivíduo no momento do diagnóstico da doença e a idade do indivíduo no momento da pesquisa. Desta forma, uma idade de diagnóstico maior que a idade no momento da pesquisa caracteriza a censura.
Abstract: The objective of this work is to present methods of regression trees for censored and correlated data. The dataset analyzed was obtained from a survey, in which 119 families (1712 individuals) living in Baependi village, in the Brazilian state of Minas Gerais, were interviewed. Two methodologies based on the proportional hazard model are presented. The first disregards the possible correlation among the individuals of the same family, using the first step of a full likelihood estimation procedure for splitting nodes. In the second methodology, the correlation among the individuals of the same family is incorporated in the proportional hazard model through a frailty variable with Gamma distribution. In this case, the value of the Score statistic is used for choosing the best splitting node. The main purpose of the analysis is to evaluate the variables that increase the risk of hypertension, type II diabetes and high cholesterol, which are the top three main factors that increase the risk of heart conditions. The response variables are the age-of-onset of these risk factors. Censoring is defined by observing the individual's age-of-onset at the moment of diagnosis and also at the moment of the survey. This way, an age-of-onset higher than the age at the moment of the survey indicates censoring.
Mestrado
Estatistica
Mestra em Estatística
APA, Harvard, Vancouver, ISO, and other styles
47

Liang, Yi. "Likelihood ratio test for the presence of cured individuals : a simulation study /." Internet access available to MUN users only, 2002. http://collections.mun.ca/u?/theses,157472.

Full text
APA, Harvard, Vancouver, ISO, and other styles
48

Tordoff, Kevin P. "Estimating failure probabilities and testing for treatment effects in the presence of competing risks." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1196211881.

Full text
APA, Harvard, Vancouver, ISO, and other styles
49

Riddlesworth, Tonya. "Estimation for the Cox model with various types of censored data." Doctoral diss., University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4827.

Full text
Abstract:
In survival analysis, the Cox model is one of the most widely used tools. However, up to now there has not been any published work on the Cox model with complicated types of censored data, such as doubly censored data, partly-interval censored data, etc., while these types of censored data have been encountered in important medical studies, such as cancer, heart disease, diabetes, etc. In this dissertation, we first derive the bivariate nonparametric maximum likelihood estimator (BNPMLE) F[subscript n](t,z) for joint distribution function F[sub 0](t,z) of survival time T and covariate Z, where T is subject to right censoring, noting that such BNPMLE F[subscript n] has not been studied in statistical literature. Then, based on this BNPMLE F[subscript n] we derive empirical likelihood-based (Owen, 1988) confidence interval for the conditional survival probabilities, which is an important and difficult problem in statistical analysis, and also has not been studied in literature. Finally, with this BNPMLE F[subscript n] as a starting point, we extend the weighted empirical likelihood method (Ren, 2001 and 2008a) to the multivariate case, and obtain a weighted empirical likelihood-based estimation method for the Cox model. Such estimation method is given in a unified form, and is applicable to various types of censored data aforementioned.
ID: 030646247; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2011.; Includes bibliographical references (p. 101-104).
Ph.D.
Doctorate
Mathematics
Sciences
Mathematics
APA, Harvard, Vancouver, ISO, and other styles
50

Tsai, Rodrigo 1974. "Aplicações de cópulas em modelos de riscos múltiplos dependentes e em modelos de misturas de distribuições." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/305843.

Full text
Abstract:
Orientador: Luiz Koodi Hotta
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica
Made available in DSpace on 2018-08-21T13:55:30Z (GMT). No. of bitstreams: 1 Tsai_Rodrigo_D.pdf: 3859687 bytes, checksum: 1064b1fa05b98307d97763bb79e95de4 (MD5) Previous issue date: 2012
Resumo: Nesse trabalho discutimos aplicações de cópulas a modelos de riscos múltiplos com dependência e modelos de misturas de distribuições. Numa primeira parte analisamos a inclusão de dependência entre os fatores de risco do modelo de riscos múltiplos. Os modelos de riscos múltiplos são uma família de modelos flexíveis para representar dados de tempos de vida. Suas maiores vantagens sobre os modelos de risco simples incluem a habilidade de representar funções de taxa de falha com formas não usuais e a facilidade de incluir covariáveis. O objetivo principal dessa parte é modelar a dependência existente entre as causas latentes de falha do modelo de riscos múltiplos por meio de funções de cópulas. A escolha da função de cópulas bem como das funções de distribuição dos tempos latentes de falha resultam numa classe flexível de distribuições de sobrevivência que é capaz de representar funções de taxa de falha de formas multimodais, forma de banheira e contendo efeitos locais dados pela concorrência dos riscos. A identificação e estimação do modelo proposto também são discutidas. Ao eliminar a restrição de suporte positivo para as variáveis latentes, o método pode ser utilizado para gerar uma família rica de distribuições univariadas contendo assimetrias e múltiplas modas. Na segunda parte propomos um modelo de mistura de distribuições generalizado utilizando cópulas. O parâmetro da cópula é útil para definir formas de assimetria e ponderar com maior ou menor peso determinadas regiões do suporte das distribuições componentes para compor a mistura. pesos das distribuições componentes variam no suporte da distribuição e não são restritos à soma unitária. A modelagem resultante acrescenta uma maior flexibilidade aos modelos de misturas na representação de dados com densidades de várias formas multimodais e assimétricas. O modelo tem como casos particulares o modelo de mistura tradicional, o modelo de riscos múltiplos e o modelo de fração de cura. Os modelos são aplicados a dados simulados e reais da literatura. Foram utilizados os métodos de estimação de máxima verossimilhança e os critérios de ajuste de Akaike e Bayesiano para a seleção dos modelos. Os modelos representaram bem os conjuntos de dados analisados em comparação com metodologias propostas na literatura
Abstract: In this work, we discuss the application of copula to polyhazard and mixture models. First we analyse the inclusion of dependence among failure causes in the polyhazard models. The polyhazard models constitute a family of flexible models to represent lifetime data. Their main advantages over single hazard models include the ability to represent hazard rate functions with unusual shapes and the ease of including covariates. The main purpose in this first part is to model the dependence that exists among the latent causes of failure in the polyhazard model by copula functions. The choice of the copula function as well as the latent failure distributions produces a flexible class of survival distributions that is able to model hazard functions with unusual shapes such as bathtub or multimodal curves, while also modelling local effects given by the competing risks. The model identification and estimation are also discussed. Dropping the restriction of positive support for the latent variables, the method can be used to generate a rich family of univariate distributions with asymmetries and multiple modes. In the second part a generalized mixture model using copula functions is proposed. To assemble the mixture model, the parameter of the copula function is used to define asymmetry shapes and to attribute more or less weight to chosen regions of the component distributions. The weights of the component distributions vary on the support of the distribution and are not restricted to the unitary sum. The resulting model increases the flexibility of the mixture models to represent data with densities with several multimodal and asymmetric shapes. Special cases of the model are the traditional mixture models, the polyhazard model, and the cure fraction model. Simulated and empirical data from the literature are analysed by the proposed models. The estimation was done by maximum likelihood methods and the selection of the models used the Akaike and Bayesian criteria. The proposed models exhibited very good fit to the data sets in comparison to other methodologies presented in the literature
Doutorado
Estatistica
Doutor em Estatística
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the bibliographies on the topic 'Survival analysis (Biometry)' for other source types:
Journal articles Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography