• Communications for Statistical Applications and Methods
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• v.27 no.1
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• pp.149-161
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• 2020

In this paper we extend the functional principal component analysis for real-valued random functions to the case of Hilbert-space-valued functional random objects. For this, we introduce an autocovariance operator acting on the space of real-valued functions. We establish an eigendecomposition of the autocovariance operator and a Karuhnen-Loève expansion. We propose the estimators of the eigenfunctions and the functional principal component scores, and investigate the rates of convergence of the estimators to their targets. We detail the implementation of the methodology for the cases of compositional vectors and density functions, and illustrate the method by analyzing time-varying population composition data. We also discuss an extension of the methodology to multivariate cases and develop the corresponding theory.

• Journal of the Korea Institute of Military Science and Technology
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• v.2 no.2
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• pp.52-60
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• 1999

By implementing the Systems Engineering process for the aircraft preliminary design, functional analysis study is performed, hence Functional Interface Data Flow(FIDF) and Functional Flow Block Diagram(FFBD) are generated. Based on FIDF and FFBD, allocable and non-allocable design/performance/RM＆S requirements are allocated to the appropriate levels. Weight and cost tracking and design margin management methodologies are studied and implemented for the balanced aircraft design.

• The Korean Journal of Applied Statistics
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• v.32 no.4
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• pp.607-618
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• 2019

A new and interesting task in statistics is to effectively analyze functional data that frequently comes from advances in modern science and technology in areas such as meteorology and biomedical sciences. Functional linear regression with scalar response is a popular functional data analysis technique and it is often a common problem to determine a functional association if a functional predictor variable affects the scalar response in the models. Recently, Kong et al. (Journal of Nonparametric Statistics, 28, 813-838, 2016) established classical testing methods for this based on functional principal component analysis (of the functional predictor), that is, the resulting eigenfunctions (as a basis). However, the eigenbasis functions are not generally suitable for regression purpose because they are only concerned with the variability of the functional predictor, not the functional association of interest in testing problems. Additionally, eigenfunctions are to be estimated from data so that estimation errors might be involved in the performance of testing procedures. To circumvent these issues, we propose a testing method based on fixed basis such as B-splines and show that it works well via simulations. It is also illustrated via simulated and real data examples that the proposed testing method provides more effective and intuitive results due to the localization properties of B-splines.

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.971-978
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• 2014

This study investigates the developmental conditions of functional clothes for the elderly. First, preceding studies and relevant web sites were analyzed along with a survey of commercial functional elderly clothes in Korea. A KIPRIS patent information database was used to study registered and disclosed patents and utility models in order to analyze patent application trends in relevant fields. Patents were searched by year of application from 1990 to 2013. Keywords used for searching included 'senior, aged, and elderly'. Among collected data, overlapping and irrelevant data were excluded to select 162 cases for analysis. Details of analysis are annual patent application trends of functional elderly clothes, topic analysis, shape and characteristics. An examination of commercially available functional clothing products for the elderly indicated that most of products were developed in the form of inner wear or protective clothing for seniors who have bodily discomfort. An annual patent application of functional elderly clothes showed slight fluctuations; however, there was an overall increase. For patent topics, technologies related to secretion and excretion were the most at 47 cases total (29%), followed by 23 cases (14%) on biometric information technology. However, the development of relevant technologies seems necessary in the future as therapeutic function and fiber technologies gradually stagnate.

• Korean Management Science Review
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• v.24 no.2
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• pp.57-72
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• 2007

Many Applications of scientific research have coupled with functional data signal clustering techniques to discover novel characteristics that can be used for the diagnoses of several issues. In this article we present an interpretable multi-scale cluster hierarchy framework for clustering functional data using its multi-aspect frequency information. The suggested method focuses on how to effectively select transformed features/variables in unsupervised manner so that finally reduce the data dimension and achieve the multi-purposed clustering. Specially, we apply our suggested method to mutual fund returns and make superior-performing funds group based on different aspects such as global patterns, seasonal variations, levels of noise, and their combinations. To promise our method producing a quality cluster hierarchy, we give some empirical results under the simulation study and a set of real life data. This research will contribute to financial market analysis and flexibly fit to other research fields with clustering purposes.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.40-54
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• 2006

It's not easy to detect the high quality and functional compounds for control quality of food materials. The electronic nose was an instrument, which comprised of an array of electronic chemical sensors with partial specificity and an appropriate pattern recognition system, capable of recognizing simple or complex odors. It can conduct fast analysis and provide simple and straightforward results and is best suited for quality control and process monitoring in the field of functional foods. Numbers of applications of an electronic nose in the functional food industry include discrimination of habitats for medicinal food materials, monitoring storage process, lipid oxidation, and quality control of food and/or processing with principal component analysis, neural network analysis and the electronic nose based on GC-SAW sensor. The electronic nose would be possibly useful for a wide variety of quality control in the functional food and plant cultivation when correlating traditional analytical instrumental data with sensory evaluation results or electronic nose data.

• The Research Journal of the Costume Culture
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• v.14 no.6
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• pp.1056-1068
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• 2006

The purpose of this study is to examine the changes and the using condition of functional cosmetics through articles of newspaper and the survey on functional cosmetics. The data analysis examined newspaper articles that demonstrate a grasp of the general trends of cosmetics, and these articles were chosen from the "Cosmetics Newspapers" and the "Jangeop Newspaper" with content primarily emphasizing articles about cosmetics. All articles on functional cosmetics were collected for the period from 2000 to 2005, and excluding repeated articles a total of 703 cases were examined. In addition, a survey was performed to examine how much women are using functional cosmetics and what the current state of their use is. This survey was conducted from October $1{\sim}20$, 2004, and respondents consisted of 350 adult females living in the areas of Daejeon, North and South Chungcheong Provinces and Daegu. Responses from a total of 302 individuals were included in the data analysis. The results of this study show a situation where the current use of functional cosmetics is gradually increasing, and because of external changes in the skin resulting from the development of modern society, functional cosmetics are being used by women as a means of increasing their opportunities for personal expression due to their skin improvement effects as well as increased confidence and a sense of satisfaction.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2000.11a
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• pp.41-44
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• 2000

With the advent of DNA microarray and "chip" technologies, gene expression in an organism can be monitored on a genomic scale, allowing the transcription levels of many genes to be measured simultaneously. Functional interpretation of massive expression data and linking such data to DNA sequences have become the new challenges to bioinformatics. I will us yeast cell cycle expression data analysis as an example to demonstrate how special database and computational methods may be used for extracting functional information, I will also briefly describe a novel clustering algorithm which has been applied to the cell cycle data.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.380-391
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• 1998

This study was conducted to develop a theoretical model for the determinants of activities of daily living in Korean rural elderly people. The theoretical model was derived from Lawton's Ecological Model to explain human behavior. The model includes determinant variables for functional status such as age, sex, physical status, cognitive status, physical environment, social environment, and depression. Data for this study was collected from 189 elderly people in a rural district near Chonju City. The data was analyzed with SPSS PC/sup +/4.1 and LISREL 8. The analysis of the data showed that the first proposed theoretical model did not fit the collected data well. In order to increase the fit of the model to the data, the model was modified by deleting the exogenous variables of sex, physical environment, and social environment. The fit of the modified model to the data was increased and was move suitable. The results of this study show that the determinants of the activities of Korean rural elderly people were age, perceived physical condition, cognitive status, and depressional status. Age has a significant direct and indirect effect on the activities of daily living of rural elderly people. Perceived physical condition has a significant indirect effect through depression on activities of daily living. Cognitive status also has a significant indirect effect through depression on functional status. Depression has a significant direct effect on the functional status. Physical environment and social environment showed reversal relationships to functional status. In conclusion, the results of this study show that personal characteristic factors are more important than environmental characteristic factors for functional status of elderly people. However, the importance of depression to functional status in Korean rural elderly people and the reverse relationship between social environment and functional status, reflect Korean specificity. Korean nursing needs to focus more on this Korean specificity in order to develop nursing knowledge and practice appropriate to Korean people.

• International Journal of Advanced Culture Technology
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• v.10 no.3
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• pp.313-324
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• 2022

This study aims to quantitatively understand the influence of changes in functional cosmetics purchasing sentiment on purchasing behavior and purchase satisfaction after the COVID-19 pandemic and present empirical analysis results regarding the rapidly changing cosmetics consumption market. This study empirically analyzed the structural relationship between non-face-to-face service purchase behavior, functional cosmetics purchase behavior, and functional cosmetics purchase satisfaction to predict purchase behavior of functional cosmetics by psychological characteristics after COVID-19. The collected data were analyzed using SPSS 22.0 (Statistical Package for Social Science) program and Amos 21.0, and correlation analysis was performed to understand the relationship between consumers' purchasing behaviors of functional cosmetics according to their perception of risk of COVID-19 carried out.Summarizing the results of this study, it was found that the higher the anxiety after the corona outbreak, the higher the non-face-to-face service purchase behavior and the functional cosmetics purchase behavior. It was found that purchase satisfaction increased when purchasing behavior of functional cosmetics increased, but purchase satisfaction decreased as anxiety increased after the outbreak of Corona.In this study, a sample of 1452 people were used as research data, and the theoretical implications for the development of functional cosmetics were presented by confirming the effect of changes in non-face-to-face service purchase behavior according to psychological characteristics after Corona 19 on consumer satisfaction.