51 |
Eliminating Redundant and Less-informative RSS News Articles Based on Word Similarity and A Fuzzy Equivalence RelationGarcia, Ian 10 January 2007 (has links) (PDF)
The Internet has marked this era as the information age. There is no precedent in the amazing amount of information, especially network news, that can be accessed by Internet users these days. As a result, the problem of seeking information in online news articles is not the lack of them but being overwhelmed by them. This brings huge challenges regarding processing of online news feeds, i.e., how to determine which news article is important, how to determine the quality of each news article, and how to filter irrelevant and redundant information. In this thesis, we propose a method for filtering redundant and less-informative RSS news articles that solves the problem of excessive number of news feeds observed in RSS news aggregators. Our filtering approach measures similarity among RSS news entries by using the Fuzzy-Set Information Retrieval model and a fuzzy equivalent relation for computing word/sentence similarity to detect redundant and less-informative news articles.
|
52 |
Bilder som ska skapa trygghet : En studie om hur bilder kan minska oro inför och uppmuntra deltagande i gynekologisk cellprovtagningNielsen, Isabelle January 2023 (has links)
Idag erbjuds alla kvinnor mellan åldern 23 – 70 gratis gynekologisk cellprovtagning i Sverige. Trots detta är det bara 63,7% i åldersgruppen 23 – 29 som deltar i screeningen. Kallelse till besök kommer via posten. I denna studie har det undersökts om man med hjälp av visualiseringar kan få fler kvinnor att delta i gynekologisk cellprovtagning samt att minska obehaget inför ett besök. Under studiens gång har gestaltningsförslag tagits fram med målet att öka deltagandet. Tidigare studier kring varför kvinnor i Sverige avböjer att delta i gynekologisk cellprovtagning och hälsokommunikation tillsammans med bilder samt teorier inom kognition, perception, bild och text i samspel har legat till grund för hela arbetet. Metoder som intervju, dokumentanalys och skiss har använts för att motivera gestaltningsförslagets utformning. Allt detta resulterade i ett gestaltningsförslag i form av ett informationsblad som skickas med det brev den nuvarande kallelse kommer i, till de kvinnor som inte tidigare har valt att delta i provtagningen i Sverige. Informationsbladet innehåller illustrationer som komplement till information om vad HPV är, hur det sprids, varför det är viktigt att delta och hur själva provtagnings processen går till. Resultatet pekar mot att större andel av målgruppen hade övervägt att delta i screeningen samt att de upplever att obehaget skulle minskas vid användande av illustrationer. / Nowadays all women between the ages of 23 - 70 get offered free pap smear in Sweden. Despite this, only 63,7% attend the screening between the ages of 23 – 29. The women receive a mail that include a call notice for the visit. This study is going to explore how visualization could help increase the amount that attend the pap smear and reduce the discomfort before a visitation. During the study, an artefact was created. Previous studies about why women in Sweden do not participate in pap smear testing, images in health communication and theories about cognition, perception and image and text in interaction laid the foundation for the work. Methods like interviews, documentation analysis and sketches were used to motivate the artefact design. All of this concluded in an artefact representing an information sheet, which is supposed to be sent out alongside the mail of the current call notice to all women in Sweden who have decided to not attend the pap smear. The information sheet includes information about what HPV is, how it spreads, why it is important to attend, and how the actual process of the testing is done, with illustrations as a supplement. The results point toward an indication that more women in Sweden would consider attending the pap smear, and that the discomfort about the process is reduced.
|
53 |
Robotic Search Planning In Large Environments with Limited Computational Resources and Unreliable CommunicationsBiggs, Benjamin Adams 24 February 2023 (has links)
This work is inspired by robotic search applications where a robot or team of robots is equipped with sensors and tasked to autonomously acquire as much information as possible from a region of interest. To accomplish this task, robots must plan paths through the region of interest that maximize the effectiveness of the sensors they carry. Receding horizon path planning is a popular approach to addressing the computationally expensive task of planning long paths because it allows robotic agents with limited computational resources to iteratively construct a long path by solving for an optimal short path, traversing a portion of the short path, and repeating the process until a receding horizon path of the desired length has been constructed. However, receding horizon paths do not retain the optimality properties of the short paths from which they are constructed and may perform quite poorly in the context of achieving the robotic search objective. The primary contributions of this work address the worst-case performance of receding horizon paths by developing methods of using terminal rewards in the construction of receding horizon paths. We prove that the proposed methods of constructing receding horizon paths provide theoretical worst-case performance guarantees. Our result can be interpreted as ensuring that the receding horizon path performs no worse in expectation than a given sub-optimal search path. This result is especially practical for subsea applications where, due to use of side-scan sonar in search applications, search paths typically consist of parallel straight lines. Thus for subsea search applications, our approach ensures that expected performance is no worse than the usual subsea search path, and it might be much better.
The methods proposed in this work provide desirable lower-bound guarantees for a single robot as well as teams of robots. Significantly, we demonstrate that existing planning algorithms may be easily adapted to use our proposed methods. We present our theoretical guarantees in the context of subsea search applications and demonstrate the utility of our proposed methods through simulation experiments and field trials using real autonomous underwater vehicles (AUVs). We show that our worst-case guarantees may be achieved despite non-idealities such as sub-optimal short-paths used to construct the longer receding horizon path and unreliable communication in multi-agent planning. In addition to theoretical guarantees, An important contribution of this work is to describe specific implementation solutions needed to integrate and implement these ideas for real-time operation on AUVs. / Doctor of Philosophy / This work is inspired by robotic search applications where a robot or team of robots is equipped with sensors and tasked to autonomously acquire as much information as possible from a region of interest. To accomplish this task, robots must plan paths through the region of interest that maximize the effectiveness of the sensors they carry. Receding horizon path planning is a popular approach to addressing the computationally expensive task of planning long paths because it allows robotic agents with limited computational resources to iteratively construct a long path by solving for an optimal short path, traversing a portion of the short path, and repeating the process until a receding horizon path of the desired length has been constructed. However, receding horizon paths do not retain the optimality properties of the short paths from which they are constructed and may perform quite poorly in the context of achieving the robotic search objective. The primary contributions of this work address the worst-case performance of receding horizon paths by developing methods of using terminal rewards in the construction of receding horizon paths. The methods proposed in this work provide desirable lower-bound guarantees for a single robot as well as teams of robots. We present our theoretical guarantees in the context of subsea search applications and demonstrate the utility of our proposed methods through simulation experiments and field trials using real autonomous underwater vehicles (AUVs). In addition to theoretical guarantees, An important contribution of this work is to describe specific implementation solutions needed to integrate and implement these ideas for real-time operation on AUVs.
|
54 |
Risk-Aware Human-In-The-Loop Multi-Robot Path Planning for Lost Person Search and RescueCangan, Barnabas Gavin 12 July 2019 (has links)
We introduce a framework that would enable using autonomous aerial vehicles in search and rescue scenarios associated with missing person incidents to assist human searchers. We formulate a lost person behavior model and a human searcher model informed by data collected from past search missions. These models are used to generate a probabilistic heatmap of the lost person's position and anticipated searcher trajectories. We use Gaussian processes with a Gibbs' kernel for data fusion to accurately model a limited field-of-view sensor. Our algorithm thereby computes a set of trajectories for a team of aerial vehicles to autonomously navigate, so as to assist and complement human searchers' efforts. / Master of Science / Our goal is to assist human searchers using autonomous aerial vehicles in search and rescue scenarios associated with missing person incidents. We formulate a lost person behavior model and a human searcher model informed by data collected from past search missions. These models are used to generate a probabilistic heatmap of the lost person’s position and anticipated searcher trajectories. We use Gaussian processes for data fusion with Gibbs’ kernel to accurately model a limited field-of-view sensor. Our algorithm thereby computes a set of trajectories for a team of aerial vehicles to autonomously navigate, so as to assist and complement human searchers’ efforts.
|
55 |
Contributions méthodologiques à l’estimation de la survie nette : comparaison des estimateurs et tests des hypothèses du modèle du taux en excès / Methodological contribution to net survival estimation : estimator comparison and test of the parametric hazard model assumptionDanieli, Coraline 16 December 2014 (has links)
La survie nette est un indicateur très utilisé en épidémiologie des cancers. Il s'agit de la survie que l'on observerait si la seule cause de mortalité était le cancer ; il est le seul indicateur épidémiologique utilisable à des fins de comparaisons de survie (entre périodes/pays) car il s'affranchit des éventuelles différences de mortalité dues aux autres causes que le cancer. Le premier objectif de notre travail était d'analyser les performances des différentes méthodes d'estimation de la survie nette sur données simulées ainsi que sur données réelles afin que les méthodes non biaisées soient reconnues scientifiquement et soient les seules à être utilisées par la suite. Nous avons ainsi démontré que deux approches étaient capables d'estimer sans biais la survie nette : l'approche non paramétrique de Pohar-Perme et l'approche reposant sur une modélisation multivariée du taux de mortalité en excès dû au cancer. Cette dernière approche impose une stratégie de construction difficile à mettre en place. Le deuxième objectif était de développer une boîte à outils composée de différents tests permettant de vérifier les différentes hypothèses faites lors de la construction d'un modèle de régression du taux de mortalité en excès. Ces hypothèses concernent habituellement la proportionnalité ou non de l'effet des covariables, leur forme fonctionnelle, ainsi que la fonction de lien utilisée. Le troisième objectif était une application épidémiologique qui visait à étudier l'impact des facteurs pronostiques, tel que le stade au diagnostic, sur la survie nette conditionnelle, en d'autres termes sur la dynamique du taux de mortalité en excès, après la survenue d'un cancer du côlon / Net survival is one of the most important indicators in cancer epidemiology. It is defined as the survival that would be observed if cancer were the only cause of death. This is the only one indicator allowing comparisons of cancer impact between countries or time periods because it is not influenced by death because of other causes. The first objective of this work was to compare the performance of several estimators of the net survival in a simulation study and then on real data in order to promote unbiased methods. Those methods are the non-parametric Pohar-Perme method and the parametric multivariable excess rate model. The latest one needs a model building strategy. The use of diagnostic procedures for model checking is an essential part of the modeling process. The second objective was to develop a tool box composed of diagnostic tools allowing to check hypothesis usually considered when constructing an excess mortality rate model, that is, the proportionality or not of the effect of covariates, their functional form and the link function. The third objective deals with the study of the impact of prognostic variables, such as stage at diagnosis, on conditional net survival, that is, on the dynamic of the excess hazard mortality after the diagnosis of colon cancer
|
56 |
An Informed System Development Approach to Tropical Cyclone Track and Intensity ForecastingRoy, Chandan January 2016 (has links)
Introduction: Tropical Cyclones (TCs) inflict considerable damage to life and property every year. A major problem is that residents often hesitate to follow evacuation orders when the early warning messages are perceived as inaccurate or uninformative. The root problem is that providing accurate early forecasts can be difficult, especially in countries with less economic and technical means. Aim: The aim of the thesis is to investigate how cyclone early warning systems can be technically improved. This means, first, identifying problems associated with the current cyclone early warning systems, and second, investigating if biologically based Artificial Neural Networks (ANNs) are feasible to solve some of the identified problems. Method: First, for evaluating the efficiency of cyclone early warning systems, Bangladesh was selected as study area, where a questionnaire survey and an in-depth interview were administered. Second, a review of currently operational TC track forecasting techniques was conducted to gain a better understanding of various techniques’ prediction performance, data requirements, and computational resource requirements. Third, a technique using biologically based ANNs was developed to produce TC track and intensity forecasts. Systematic testing was used to find optimal values for simulation parameters, such as feature-detector receptive field size, the mixture of unsupervised and supervised learning, and learning rate schedule. Five types of 2D data were used for training. The networks were tested on two types of novel data, to assess their generalization performance. Results: A major problem that is identified in the thesis is that the meteorologists at the Bangladesh Meteorological Department are currently not capable of providing accurate TC forecasts. This is an important contributing factor to residents’ reluctance to evacuate. To address this issue, an ANN-based TC track and intensity forecasting technique was developed that can produce early and accurate forecasts, uses freely available satellite images, and does not require extensive computational resources to run. Bidirectional connections, combined supervised and unsupervised learning, and a deep hierarchical structure assists the parallel extraction of useful features from five types of 2D data. The trained networks were tested on two types of novel data: First, tests were performed with novel data covering the end of the lifecycle of trained cyclones; for these test data, the forecasts produced by the networks were correct in 91-100% of the cases. Second, the networks were tested with data of a novel TC; in this case, the networks performed with between 30% and 45% accuracy (for intensity forecasts). Conclusions: The ANN technique developed in this thesis could, with further extensions and up-scaling, using additional types of input images of a greater number of TCs, improve the efficiency of cyclone early warning systems in countries with less economic and technical means. The thesis work also creates opportunities for further research, where biologically based ANNs can be employed for general-purpose weather forecasting, as well as for forecasting other severe weather phenomena, such as thunderstorms.
|
57 |
Faktaskriv med eget driv : En jämförande studie av faktatextskrivande på lågstadiet i den traditionella skolan och inom Montessoripedagogiken / Writing facts with motivation : A study about writing informative texts in primary school comparing traditional education and the Montessori educationHammar, Johanna January 2017 (has links)
Syftet med denna uppsats är dels att undersöka de innebörder lärare ger undervisningen med faktatexter och att skriva faktatexter med egna ord på lågstadiet och dels att inom samma område undersöka om det finns några skillnader mellan den traditionella skolan och montessoripedagogiken. För att uppfylla syftet genomfördes kvalitativa gruppintervjuer med lärare från två pedagogiska inriktningar, montessoripedagogiken och den traditionella skolan. Min undersökning visar att när det handlar om att skriva faktatexter och att utmana elever i de yngre åldrarna att skriva faktatexter med egna ord så skiljer sig inte montessoriundervisningen och den traditionella skolan specifikt. De resultat som framkom var att man inom båda pedagogiska inriktningarna utgår från elevgruppen när ett faktatextarbete startas upp samt anser att vikten av begreppsförståelsen är stor. När det kommer till att låta eleverna skriva faktatexter med egna ord visade undersökningen att alla lärare använder samma metod, nämligen att ta bort befintlig text och låta eleverna skriva det de minns. / The aim of this thesis is divided into two part. Firstly, the aim is to investigate what meanings teachers associate with the teaching of informative texts and their thoughts on pupils writing texts with their own words at primary school. Secondly, the aim is to investigate whether there are any differences between traditional education and Montessori education with respect to the latter aim. In order to fulfill this aim, qualitative group interviews were conducted with teachers from the two pedagogical orientations. My survey shows that when it comes to writing informative texts and challenging students of the younger ages to write informative texts with their own words there are no major differences between the traditional approach and Montessori approach. The result also shows that in both educational settings the teachers start by learning what the students already know about the subject and proceed from there. They think it is important to teach the children new vocabulary as well. When it comes to letting students write informative texts using their own words, the survey shows that teachers from the both pedagogical orientations use the same method, namely to put aside the original text and let the students write what they remember.
|
58 |
Historiska manér : Hur förändring av manér kan förtydliga ett historiskt förloppThiel, Rebecca January 2019 (has links)
The following essay is a thesis in Information Design with orientation in Informative illustration. The collaboration with the TT News Agency, which forms the basis of the work, presupposes that an information graphic about the history of smoking is produced, which occurs in connection with the new tobacco law coming into force on July 1, 2019. The purpose of the thesis is to examine how the formation of image manners can affect the historical connection to an illustration, and examine whether this can contribute to a perceived development of time. The aim of the enquiry is to explore whether it is possible to create a "timeline" without a line, using manners. Through data collection and theories in semiotics, visual rhetoric, cognitive visualization and perception, as well as previous experiences throughout the education in Informative illustration, concept and design proposals were created. Methods used in the thesis are image analysis and testing, which took the form of an internet survey. The former was implemented to understand how the manners of the illustration should look like to create an affiliation to the stated time periods. The latter was carried out to investigate whether the target group experiences the connection between the illustrations and the time periods, and to investigate whether the illustrations together contribute to a historical development. The result of the study shows that manners can contribute with a historical connection, but the illustrations with a more distinctive appearance are considered easier to interpret. The result also concluded that object´s, such as clothes and jewelry, contributes to the understanding of the illustrations historical affiliation. Manners can also contribute to a perceived historical development, whereupon 96 percent of the survey participants perceived this. / Följande undersökning är ett examensarbete i Informationsdesign med inriktningen Informativ illustration. Samarbetet med TT Nyhetsbyrån, som ligger till grund för arbetet, förutsätter att en informationsgrafik om rökningens historia gestaltas, vilket sker i samband med att den nya tobakslagen träder i kraft 1 juli 2019. Syftet med examensarbetet är att undersöka hur utformning av bildmanér kan påverka den historiska kopplingen till en illustration, samt undersöka om detta kan bidra till en upplevd utveckling av tid. Målet med undersökningen är att utforska om det är möjligt att skapa en ”tidslinje” utan linje, med hjälp av manér.Genom datainsamling och teorier inom semiotik, visuell retorik, kognitiv visualisering och perception, samt tidigare erfarenheter inom utbildningen Informativ illustration, utformades koncept- och gestaltningsförslag. Metoder som brukats i arbetet är bildanalys och utprovning, vilket tog form utav en surveyundersökning. Den förstnämnda genomfördes för att få en inblick i hur gestaltningarnas manér bör se ut för att skapa en tillhörighet till dess specifika tidsperiod. Den nästnämnda genomfördes för att undersöka om målgruppen upplever illustrationernas koppling till de tänka tidsperioderna , samt undersöka om målgruppen anser att illustrationerna i samverkan bidrar till en historisk utveckling.Resultatet av undersökningen påvisar att manér kan bidra med en historisk koppling, däremot anses de illustrationer med ett mer utmärkande manér enklare att avläsa. Det framkom även att bildobjekt och föremål, likt kläder och smycken, är bidragande vid förståelse för illustrationens historiska tillhörighet. Likaså kan manér bidra med en upplevd historisk utveckling, varpå 96 procent av enkätens deltagare anses uppfatta detta.
|
59 |
Marcadores Genéticos de Ancestralidade em Comunidades Fundadas por Açorianos na Ilha de Santa Catarina / Ancestry Informative Markers in Partially Isolated Communities Founded by Azoreans in the Santa Catarina IslandMuniz, Yara Costa Netto 30 May 2008 (has links)
As comunidades da Costa da Lagoa (CL) e São João do Rio Vermelho (RV) estão localizadas na Ilha de Santa Catarina, Sul do Brasil, e foram colonizadas na segunda metade do século XVIII por imigrantes vindos do Arquipélago de Açores. Estudos demográficos e genéticos mostraram também a presença de componentes africanos e ameríndios. CL é considerada isolada devido à sua localização geográfica e RV está em fase de quebra de isolado pelo aumento de migração, principalmente nos últimos 20 anos. Os objetivos deste estudo foram verificar a hipótese dos diferentes graus de isolamento nas duas comunidades, estimar as proporções de mistura étnica, assim como estabelecer comparações entre elas e com portugueses, especialmente açorianos. As freqüências de oito AIMs (FY, RB, LPL, AT3, Sb19.3, APO, PV92 e CYP1A1) e dos STRs do haplótipo estendido do cromossomo Y foram então estimadas nas comunidades de CL (n=120), RV (n=163) e na amostra urbana HM (n=50) a partir de PCR e PCR-RFLP. A informação obtida a partir das mesmas foi comparada com resultados de estudos históricos, demográficos e genéticos prévios realizados nestas comunidades. As análises estatísticas empregaram programas já descritos (GENEPOP, DISPAN, GDA, ARLEQUIN, STRUCTURE, MVSP e ADMIX 2 e 3). Com relação ao cromossomo Y, concluímos que as duas comunidades ainda apresentam semelhanças considerando as análises de diferenciação gênica. Isto pode ser devido à origem comum e recente e à proximidade geográfica, o que torna possível um fluxo de homens entre as duas comunidades. Entretanto, o acréscimo no número de marcadores ligados ao cromossomo Y permitiu a diferenciação entre estas duas comunidades, como mostram os valores de FST e de diferenciação haplotípica. As estimativas de mistura indicam preponderância do componente europeu. Entretanto, dada à indisponibilidade da literatura, faz-se ainda necessária uma escolha mais adequada das freqüências parentais no caso dos Y-STRs. Admitindo que os AIMs sejam marcadores mais eficientes em estimativas de mistura étnica, dado seus altos diferenciais de freqüência alélica entre populações parentais, as contribuições de populações não européias (principalmente africanas) observadas mantém a hipótese de cruzamentos preferenciais entre homens portugueses e mulheres ameríndias e/ou africanas na formação das comunidades. / The communities of Costa da Lagoa (CL) and São João do Rio Vermelho (RV) are located on Santa Catarina Island, southern Brazil, and were settled on the second half of XVIII century by immigrants came from Azores Archipelago. Demographic and genetic studies have also been indicated the presence of African and Amerindian components. CL is considered genetically isolated due to its geographic localization and isolate breaking is occurring in RV due to the increased migration to the local, mainly in the last 20 years. The aims of the present study were to verify the hypothesis of the different degrees of isolation in the two communities, to estimate the proportions of ethnic admixture, as well as to establish comparisons between them and with Portuguese, particularly Azoreans. Allele frequencies of eigth AIMs (FY, RB, LPL, AT3, Sb19.3, APO, PV92 e CYP1A1) and of the extended Y haplotype STRs were estimated in the CL (n=120), RV (n=163) and in the urban sample HM (n=50) by means of PCR and PCR-RFLP. These data were compared with previous results from historical, demographical and genetical studies realized in these communities. Statistical analysis were carried out employing the GENEPOP, DISPAN, GDA, ARLEQUIN, STRUCTURE, MVSP and ADMIX 2 and 3 softwares. The communities showed more similarity in relation to Y chromosome on the analysis of gene differentiation, which could be due to the recent and common origin and the geographic proximity, and the interchange mainly male-mediated between them. However, the increased number of Y-linked STRs made possible the differentiation between these communities, as depicted by the FST values and the haplotypic differentiation. The ethnic admixture estimates detected a major European contribution but, due to the literature unavailability, a more suitable choice of the parental frequencies for the Y-STRs estimates is needed. Once AIMs are markers more efficient than Y-STRs on admixture estimates, due to their large allele frequency differentials between parental populations, the non-european contributions (mainly Africans) observed support the hypothesis of biased mating between Portuguese men and Amerindian and/or African women during the formation of these communities.
|
60 |
Estimação e comparação de curvas de sobrevivência sob censura informativa. / Estimation and comparison of survival curves with informative censoring.Cesar, Raony Cassab Castro 10 July 2013 (has links)
A principal motivação desta dissertação é um estudo realizado pelo Instituto do Câncer do Estado de São Paulo (ICESP), envolvendo oitocentos e oito pacientes com câncer em estado avançado. Cada paciente foi acompanhado a partir da primeira admissão em uma unidade de terapia intensiva (UTI) pelo motivo de câncer, por um período de no máximo dois anos. O principal objetivo do estudo é avaliar o tempo de sobrevivência e a qualidade de vida desses pacientes através do uso de um tempo ajustado pela qualidade de vida (TAQV). Segundo Gelber et al. (1989), a combinação dessas duas informações, denominada TAQV, induz a um esquema de censura informativa; consequentemente, os métodos tradicionais de análise para dados censurados, tais como o estimador de Kaplan-Meier (Kaplan e Meier, 1958) e o teste de log-rank (Peto e Peto, 1972), tornam-se inapropriados. Visando sanar essa deficiência, Zhao e Tsiatis (1997) e Zhao e Tsiatis (1999) propuseram novos estimadores para a função de sobrevivência e, em Zhao e Tsiatis (2001), foi desenvolvido um teste análogo ao teste log-rank para comparar duas funções de sobrevivência. Todos os métodos considerados levam em conta a ocorrência de censura informativa. Neste trabalho avaliamos criticamente esses métodos, aplicando-os para estimar e testar curvas de sobrevivência associadas ao TAQV no estudo do ICESP. Por fim, utilizamos um método empírico, baseado na técnica de reamostragem bootstrap, a m de propor uma generalização do teste de Zhao e Tsiatis para mais do que dois grupos. / The motivation for this research is related to a study undertaken at the Cancer Institute at São Paulo (ICESP), which comprises the follow up of eight hundred and eight patients with advanced cancer. The patients are followed up from the first admission to the intensive care unit (ICU) for a period up to two years. The main objective is to evaluate the quality-adjusted lifetime (QAL). According to Gelber et al. (1989), the combination of both this information leads to informative censoring; therefore, traditional methods of survival analisys, such as the Kaplan-Meier estimator (Kaplan and Meier, 1958) and log-rank test (Peto and Peto, 1972) become inappropriate. For these reasons, Zhao and Tsiatis (1997) and Zhao and Tsiatis (1999) proposed new estimators for the survival function, and Zhao and Tsiatis (2001) developed a test similar to the log-rank test to compare two survival functions. In this dissertation we critically evaluate and summarize these methods, and employ then in the estimation and hypotheses testing to compare survival curves derived for QAL, the proposed methods to estimate and test survival functions under informative censoring. We also propose a empirical method, based on the bootstrap resampling method, to compare more than two groups, extending the proposed test by Zhao and Tsiatis.
|
Page generated in 0.1539 seconds