Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 27 for “"Joint models"”.
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Joint models for longitudinal and survival data
… we proposed to use bivariate change point models for two longitudinal outcomes with a focus on estimating the correlation between the two change points. We adopted a Bayesian approach for parameter estimation and inference. In the second part, we considered the situation when time-to-event …
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Diagnostics for joint models for longitudinal and survival data
Joint models for longitudinal and survival data are a class of models that jointly analyse an outcome repeatedly observed over time such as a bio-marker and associated event times. These models are useful in two practical applications; firstly focusing on survival outcome whilst accounting for time …
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Joint Models for Longitudinal Analysis and Competing Risks in Survival Analysis
… these dependencies, we propose and apply several models: 1. Linking the Cause-specific Hazards Model for competing risks analyses with a model for longitudinal ordinal measurements through a correlated random effects structure. To do this, we apply a 2009 approach by Li et al. (2009), and use this …
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Joint models for nonlinear longitudinal profiles in the presence of informative censoring
… data. These techniques include standard survival models for modeling the time to gametocyte emergence and the duration of gametocytemia. The longitudinal nonlinear gametocyte profile would typically be modeled using nonlinear mixed effect models. These nonlinear models could then subsequently be …
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Joint identification in structural waveguides using wave reflection and transmission coefficients
The dynamic modelling of one-dimensional jointed structures is relevant to many engineering applications, such as pipe systems and beam networks in constructions. Currently available techniques are undermined by inadequate ability to model the joints and other discontinuities due to uncertainty in …
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Modeling and identification of flexible joints in vehicle structures
A simple, design-oriented model of joints in vehicle structures is developed. This model accounts for the flexibility, the offsets of rotation centers of joint branches, and the coupling between rotations of a joint branch in different planes. The model parameters consist of torsional spring rates, …
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The development and validation of a geometrically simplified and an accurate finite element model of the wrist joint
The injury to the wrist joint resulting from a fall onto the outstretched hand was simulated using two models. The two validated three-dimensional wrist joint models were created using the general purpose finite element software, ABAQUS. The first model, a Geometrically Simplified half symmetry …
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Spoken Language Understanding: from Spoken Utterances to Semantic Structures
… the last decades: generative and discriminative models. The former are robust to over-fitting and they are less affected by noise but they cannot easily integrate complex structures (e.g. trees). In contrast, the latter can easily integrate very complex features that can capture arbitrarily long …
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Approaches for Handling Time-Varying Covariates in Survival Models
Survival models are used in analysing time-to-event data. This type of data is very common in medical research. The Cox proportional hazard model is commonly used in analysing time-to-event data. However, this model is based on the proportional hazard (PH) assumption. Violation of this assumption …
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Semiparametric Bayesian Joint Model With Variable Selection
… time-to-event histories. Recently, methods for jointly modeling longitudinal and survival data have gained popularity in the statistical literature. In this dissertation, we consider the problem of variable selection in a joint modeling framework where longitudinal and survival data are modeled …
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Modelling multivariate longitudinal outcomes and time-to-event data
… a time-to-event outcome among subjects. Joint models for longitudinal and survival data simultaneously analyse repetitively measured outcomes and associated event times. They offer valuable applications in two contexts: accounting for time-varying covariates measured with error when …
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Joint Hedonic Travel Cost Method: Combining Revealed and Stated Preference Data to Estimate Demand for Attribute Quality of Sport Fishing in Illinois
… advances in recreation valuation: conjoint analysis and combined revealed and stated preference data. The combination of these techniques creates a joint hedonic travel cost method that consists of using better quality data to overcome the problem of multicollinearity and appearance of …
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Parental Involvement during the College Transition: Trajectories and Associations with Academic Success, Well-Being, and Individuation
… parent involvement, student outcomes, and their joint associations. Fixed and random effects were examined to determine intraindividual and interindividual change. Joint association models involved regressing the student outcome slopes onto the involvement slopes. Covariates were included (e.g., …
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Longitudinal and survival statistical methods with applications in renal medicine
… occurrences on the subsequent kidney function. Joint modelling of longitudinal and time-to-event outcome and Cox model with time-varying covariate are considered to answer the first problem. Whilst parameters are estimated by maximum likelihood (ML) using an expectation-maximisation (EM) …
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A Clearer Picture of Musculoskeletal Disorders of the Knee and Thumb Through the Lens of Image-Based Finite Element Analysis
… subchondral bone cysts (SBCs). The equine stifle joint provides a natural animal model for studying SBCs. Finite element models were used to examine three cyst sizes of approximately 0.03 cm3 (C1), 0.5 cm3 (C2), and 1 cm3 (C3) in the equine stifle joint. Fluid pressure was simulated by using a …
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Explicit Finite Element Modeling of Knee Mechanics During Simulated Dynamic Activities
… natural knee is one of the most commonly injured joints in the body due to relatively high loads and motions that can lead to debilitating degenerative diseases such as osteoarthritis. Total knee arthroplasty is a clinically successful method for eliminating pain in the osteoarthritic knee, but is …
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Causal Inference Methods for Microbiome Data
… mixed-effects zero-inflated generalized linear models (MEZIGLM) with natural effects models, this method accounts for overdispersion, zero inflation, and subject-level heterogeneity while constructing generalized confidence intervals for natural direct and indirect effects. A second-order …
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Essays on Financial Econometrics
… and testing of time series models for Value-at-Risk (VaR) and Expected</p><p>Shortfall (ES), which is the average return on a risky asset conditional on the return</p><p>being below some quantile of its distribution, namely its VaR.</p><p>The rst chapter, which is joint work …
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Methods for handling missing data in cohort studies where outcomes are truncated by death
… and dropout. We show, first, that linear mixed models and joint models (that model both the outcome and survival processes) produce immortal cohort inference. This makes the parameters in the longitudinal (sub-)model difficult to interpret. Second, a thorough comparison of well-known methods …
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DEVELOPMENTS IN E&EM GEOPHYSICS:JOINT INVERSION, TIME-SERIES ANALYSIS AND SYSTEM CALIBRATION
… and bridge between the large-scale geophysical models derived from the airborne campaign and their lithostratigraphic interpretation. At the same time, the HydroGeosITe was designed to serve as a calibration site for AEM systems, supporting future campaigns. Accordingly, a key research objective …
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