Local signal detection is useful in many scientific areas such as imaging processing and speech recognition, for extracting meaningful patterns from noisy signals. In this dissertation, we study estimation and local signal detection for spatial data distributed over irregular domains. In particular, we use bivariate splines defined on triangulations to...
Missing data is one of the major methodological problems in longitudinal studies. It not only reduces the sample size, but also can result in biased estimation and inference. It is crucial to correctly understand the missing mechanism and appropriately incorporate it into the estimation and inference procedures. Traditional methods, such...
We consider two semiparametric regression models for data analysis, the stochastic additive model (SAM) for nonlinear time series data and the additive coefficient model (ACM) for randomly sampled data with nonparametric structure. We employ the SCAD-penalized polynomial spline estimation method for estimation and simultaneous variable selection in both models. It...
Monotone additive models are useful in estimating productivity curves or analyzing disease risk where the predictors are known to have monotonic effects on the response. Existing literature mainly focuses on univariate monotone smoothing. Available methods for the estimation of monotone additive models are either difficult to interpret or have no...
A copula is the representation of a multivariate distribution. Copulas are used to model multivariate data in many fields. Recent developments include copula models for spatial data and for discrete marginals. We will present a new methodological approach for modeling discrete spatial processes and for predicting the process at unobserved...
Species diversification in aquaculture has been driven and influenced by various factors including consumer preference, technical innovations such as advances in artificial propagation, economies of scale, risk diversification, policy orientation, among others. Global aquaculture development in general has been associated with species diversification in terms of both increasing number of...
Diffusion processes in networks are common models for many domains, including species colonization, information/idea cascade, disease propagation and fire spreading. In diffusion networks, a diffusion event occurs when a behavior spreads from one node to the other following a probabilistic model, where the behavior could be species, an idea, a...
Cubic phase Li₇La₃Zr₂O₁₂ (LLZO) is a promising solid electrolyte for all solid-state lithium-ion battery, due to its reasonable ionic conductivity, stable against metallic Li, wide chemical window, and thermal and chemical stability. The main aim of this thesis is to investigate the influences of different synthesis methods on the structure...
New synthetic strategies have been investigated for nano-dimensioned
graphite particles or even isolated graphene sheets. One approach is to prepare
graphite intercalation compounds (GICs) with low layer charge density and
appropriate gallery height, followed by the colloidal dispersion or exfoliation of the
resulting GICs. A series of anions has been...
Increasing grain yield in wheat (Triticum aestivum L.) is a challenging task, because yield is a complex trait controlled by many genes and highly influenced by environmental factors. The genetic control of yield components and other traits associated with yield may be less complex and thus more manageable for breeding....