For the data exhibiting a dependency structure, the exact likelihood is rarely available to researchers mainly because of unobserved initial values and unknown innovation distributions. It is the case in practice to assume a tractable score for the data for the sake of easy analysis. The adopted tractable score is referred to as the in...
Current literature on neural connectivity and dynamics, or equivalently, structure and function, is systemically reviewed in the current article. Based on fMRI data, I have specifically discussed how changes in the connectivity of a neural network affect the spatiotemporal network dynamics qualitatively. I have also considered local dy...
Over the past decades, there has been considerable interest in applying statistical machine learning methods in survival analysis. Ensemble based approaches, especially random survival forests, have been developed in a variety of contexts due to their high precision and non-parametric nature. This article aims to provide a timely revie...
Competing risks data commonly arise when an occurrence of an event precludes other type of events from being observed. Recently, competing-risks models with frailty have been studied for clustered competing-risks data that may be correlated. In this paper, we propose a variable selection procedure for fixed effects in the cause-specifi...
Lactic acid bacteria was isolated from Chonggak and Baechu kimchi and characterized by a sugar fermentation analysis. Leuconostoc strains (1B12, BD5H and CH5H) growing at 40℃ were isolated and compared with L. mesenteroides subsp. mesenteroides KCTC 3722 grown at a mesophilic temperature (30℃). Among these, L. mesenteroides BD5H could ...
To understand the brain, it is essential to understand neuronal electrophysiological properties. The Allen Brain Atlas Data Portal contains extensive data recorded from neurons in the mouse visual cortex. Here, the electrophysiological properties of excitatory and inhibitory neurons were compared on the basis of the data provided. As i...
This study was carried out to evaluate the effects of aroma hand massage using lavender oil on the improvement of sleep quality in hospitalized elderly inpatients. The patients (>65 years old) hospitalized in K care hospital were divided into two groups: the lavender group (17 people receiving aroma hand massage using lavender oil) and...
The free radical scavenging effects of baked and extruded wheat flour products were determined. Ferulic acid was selected as a model phenolic compound and mixed with wheat flour at a level of 250 μg/g based on the flour weight. Free radical scavenging activity (FRSA) against the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) was determin...
In this paper, we propose a deep recommender system that utilizes purchase history data of customers when ratings for products are not available at all. The purchase history data of these customers are obtained between May 2014 and July 2015 from nationwide branches of a particular supermarket chain. If the customer’s purchase cycle fo...
Bayesian statistics holds promise for improved decision making with limited data. This approach will likely achieve wider acceptance in the environmental health and safety community if it is made available in easily accessible software. The objectives of this study were to explore the calculation parameters and to discuss the issues in...
In this study, we develop a novel updating-based method for penalized estimators for the mean vector and the covariance matrix. With a linear combination of predictors, the coefficients can be estimated by maximizing a penalized log likelihood function, and using coordinate descent algorithm is used to handle the l1-penalized function....
Datasets from DNA microarray experiments, which are in the form of large matrices of expression levels of genes, often have missing values. However, the existing statistical methods including the principle components analysis (PCA) and Hotelling’s t-test are not directly applicable for the datasets having missing values due to the fact...
The purpose of this study was to identify risk factors for type 2 diabetes (T2D) in Korean adults. The data were divided into two types of variables ((i) socioeconomic and demographic factors and (ii) behavioral risk factors) using data obtained through the Korea National Health and Nutrition Examination Survey (2014). Multiple logisti...
The heterogeneity of patients’ responses in many treatment programs stems from the characteristics of their diverse background. Accordingly, paradigms of clinical decisions are shifting from “one-size-fits-all” rules to individualized treatment rules (ITRs). In statistical frameworks, an ITR is defined as a mapping of patient informati...
