• Korean journal of food and cookery science
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• v.28 no.6
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• pp.741-751
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• 2012

This study was conducted to understand sensory characteristics of commercial functional beverages, to analyze and the drivers of liking and disliking of it by Korean consumers. Descriptive analysis and consumer taste testing were conducted with ten commercial products of functional beverages. Samples were consisted of good for beauty, relieving hangovers, and health tonics. For the descriptive analysis, 45 attributes were developed by ten panelists and it shows differences among the all samples. For the consumer testing, 81 panels evaluated the overall liking, acceptance of appearance, odor, flavor, and texture of 10 samples. As a result, attributes of brightness, yellow color, Nurungji flavor, roasted bean power flavor, and milky texture of functional beverages were positive drivers of liking, but attributes of astringent texture, bitter taste, and viscosity were negative drivers of liking on the commercial functional beverages.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.4
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• pp.295-299
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• 2004

The prices of domestic green tea products are relatively expensive and price differences within products of the same levels of quality are various. Also, there is no basic criteria on evaluation of green tea quality. To group 43 commercial green tea products into several parts by the principal component and cluster analyses, this work was done by use of 8 chemical constituents which were analyzed by NIR system. The principal component and cluster analyses revealed 8 groups. The first group included 16 products that had lower free amino acid and theanine contents. The second group included 5 products having higher free amino acid and theanine contents, but lower ash contents. The third group included 13 products showing medium values of 8 constituents. The IV group included 4 products having higher contents of moisture, free amino acids, and theanine. The V group included 1 product showing higher moisture but lower catechins contents. The VI group included 2 products that had higher moisture and catechins contents, but lower free amino acid and theanine contents. The VII group had higher moisture and catechins contents. The VIII group had higher ash and vitamin C contents. The free amino acid contents which were the most important in flavor evaluation of green tea quality did highly positively correlate with the contents of total nitrogen $(0.956^{**}),\;theanine\;(0.981^{**}),\;and\;caffeine\;(0.793^{**})$, but negatively with the contents of ash $(-0.884^{**})$. The catechins used as for functional ingredients did correlate with contents of caffeine(+) and vitamin C(-), respectively.

• Communications for Statistical Applications and Methods
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• v.31 no.3
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• pp.309-322
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• 2024

Identifying algae in water is important for managing algal blooms which have great impact on drinking water supply systems. There have been various microscopic approaches developed for algae classification. Many of them are based on the morphological features of algae. However, there have seldom been mathematical frameworks for comparing the shape of algae, represented as a planar continuous curve obtained from an image. In this work, we describe a recent framework for computing shape distance between two different algae based on the elastic metric and a novel functional representation called the square root velocity function (SRVF). We further introduce statistical procedures for multiple shapes of algae including computing the sample mean, the sample covariance, and performing the principal component analysis (PCA). Based on the shape distance, we classify six algal species in watersheds experiencing algal blooms, including three cyanobacteria (Microcystis, Oscillatoria, and Anabaena), two diatoms (Fragilaria and Synedra), and one green algae (Pediastrum). We provide and compare the classification performance of various distance-based and model-based methods. We additionally compare elastic shape distance to non-elastic distance using the nearest neighbor classifiers.

• Preventive Nutrition and Food Science
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• v.17 no.3
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• pp.184-191
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• 2012

The purpose of this study was to investigate the fatty acid profiles in 18 soybean cultivars grown in Korea. A total of eleven fatty acids were identified in the sample set, which was comprised of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1, ${\omega}7$), stearic (C18:0), oleic (C18:1, ${\omega}9$), linoleic (C18:2, ${\omega}6$), linolenic (C18:3, ${\omega}3$), arachidic (C20:0), gondoic (C20:1, ${\omega}9$), behenic (C22:0), and lignoceric (C24:0) acids by gas-liquid chromatography with flame ionization detector (GC-FID). Based on their color, yellow-, black-, brown-, and green-colored cultivars were denoted. Correlation coefficients (r) between the nine major fatty acids identified (two trace fatty acids, myristic and palmitoleic, were not included in the study) were generated and revealed an inverse association between oleic and linoleic acids (r=-0.94, p<0.05), while stearic acid was positively correlated to arachidic acid (r=0.72, p<0.05). Principal component analysis (PCA) of the fatty acid data yielded four significant principal components (PCs; i.e., eigenvalues>1), which together account for 81.49% of the total variance in the data set; with PC1 contributing 28.16% of the total. Eigen analysis of the correlation matrix loadings of the four significant PCs revealed that PC1 was mainly contributed to by oleic, linoleic, and gondoic acids, PC2 by stearic, linolenic and arachidic acids, PC3 by behenic and lignoceric acids, and PC4 by palmitic acid. The score plots generated between PC1-PC2 and PC3-PC4 segregated soybean cultivars based on fatty acid composition.

• Korean Journal of Medicinal Crop Science
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• v.26 no.1
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• pp.32-41
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• 2018

Background: To obtain useful safflower resources for breeding and research of functional materials, the present study was conducted to determine fatty acid compositions and antioxidant activities of 281 safflower accessions collected from East Asia including South Korea. Methods and Results: Lipid contents and fatty acids compositions were evaluated using soxhlet extraction and gas chromatography, respectively. A antioxidant activities were analyzed using a spectrophotometer. The evaluation range of safflower accessions showed very wide variation. In terms of lipid contents, the China accessions were higher than the collection from other regions, whereas antioxidant activities did not differ among regions. The result of the principal component analysis showed that the first and second principal component cumulatively explained 90.6% of the total variation. In clustering the safflower accessions, the tree showed four major clades. Group II (16 accessions) was high in lipid content, oleic acid and linoleic acid, whereas group III (50 accessions) exhibited higher antioxidant activities than other groups. Conclusions: It was recommended that the China collections be utilized as a useful resource for research on functional oil materials. These results provided valuable information for safflower breeders and researchers of functional food.

• The Korean Journal of Applied Statistics
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• v.33 no.6
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• pp.805-812
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• 2020

High-frequency data are now prevalent in financial time series. As a functional data arising from high-frequency financial time series, we are concerned with the intraday volatility to which functional principal component analysis (FPCA) is applied in order to achieve a dimension reduction. A review on FPCA and R function is made and high-frequency KOSPI volatility is analysed as an application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.2
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• pp.149-155
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• 2017

To establish cultivation areas for the stable production of yacon, this study investigated the productivity and functional component contents of yacon in eight regions of Korea from 2011 to 2013. The results of principal component analysis using these data were as follows. A survey of 16 agricultural traits and meteorological data in the eight yacon cultivation areas showed that five factors (average temperature, maximum temperature, minimum temperature, frost-free days, and fructooligosaccharide content) were highly significant at the p < 0.001 level. Among the 16 agricultural traits and meteorological data used in the main component analysis of yacon cultivation areas, approximately eight contributed to the first principal component, and approximately four contributed to each of the second and third principal components. In particular, factors related to productivity, fructooligosaccharide content, and temperature change were considered important criteria for the classification of cultivation areas. The cultivation areas were divided into three groups by principal component analysis. In Group I, containing the Jinbu and Bonghwa areas in the mid-highland region at 500-560 m above sea level, the product yield was the highest at 2,622-3,196 kg/10a, the fructooligosaccharide content was also the highest at 9.04-9.62%, and the mean temperature was $17.3-18.5^{\circ}C$. In Group II, the areas Suncheon, Okcheon, Yeoju, and Gangneung, at 20-180 m above sea level, had the lowest yield, relatively lower fructooligosaccharide content, and the highest temperature. The areas in Group III showed values intermediate between those of Group I and Group II. For the different yacon cultivation areas, the product quantity and fructooligosaccharide content differed according to the environmental temperature, and the temperature conditions and number of frost-free days are considered important indicators for cultivation sites. Therefore, in terms of producing yacon with high quality, cultivation at 500-560 m is considered to give a higher yield and functional fructooligosaccharide content.

• Korean Journal of Plant Resources
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• v.33 no.4
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• pp.293-302
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• 2020

Morphological characteristics of Ziziphus jujuba accessions, including 'Ilbon', were investigated to verify the possibility of 'Ilbon' as a breeding material. 'Ilbon' has smaller leaves and fruits and a lower total soluble solids content compared to the major Z. jujuba accessions. However, total polyphenol content and antioxidant capacity were highest in 'Ilbon' among the Z. jujuba accessions. In addition, 'Ilbon' could produce intact seeds and seed productivity of 'Ilbon' was highest compared with major Z. jujuba accessions. Principal component analysis and clustering analysis using the morphological characteristics of Z. jujuba accessions have been classified them to geographical origin. In particular, 'Ilbon' was clearly distinguished from the major Z. jujuba accessions. Therefore, 'Ilbon', which has the highest seed productivity and functional component, will be used as a material for cross breeding and will promote genetic study of Z. jujuba.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.191-194
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• 2011

문서를 이루는 단어들의 빈도수가 지수법칙(power law)를 따른다는 지프의 법칩(Zipf's law)이 있다. 이러한 단어분포를 고려하여 문서의 토픽을 찾아내는 기계학습법이 디리쉴레 프로세스(Dirichlet process) 이다. 이를 발전시켜서 데이터의 잠재 요인(latent factor)들을 베이즈 확률모델에 기반한 샘플링 바탕으로 찾는 방법이 인디언 뷔페 과정(Indian buffet process) 이다. 우리는 25가지의 특징(feature)들에 대한 점수(rating)들이 볼드(blood oxygen dependent level) 신호와 함께 주어지는 PBAIC 2007 데이터에 주성분 분석법(principal component analysis)를 적용했다. PBAIC 2007 데이터는 비디오 게임을 수행하며 기능적뇌영상(functional magnetic resonance imaging, fMRI) 촬영을 하여 얻어진 공개데이터이다. 우리의 연구에서는 주성분 분석법을 이용하여 10개의 독립 성분(independent component)들을 찾았다. 그리고 1.75초 마다 촬영된 BOLD 신호와 10개의 고유벡터(eigenvector)들간의 내적을 취하여 가중치(weight)를 구하였다. 성분들의 가중치를 낮은 순서로 정렬함으로써 각 시간마다 주도적으로 영향을 미치는 성분들을 알아낼 수 있었다.

• Korean Journal of Agricultural Science
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• v.36 no.2
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• pp.219-224
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• 2009

Two functional modified-butterfats (MF668 and MF866) were synthesized with two blends (6:6:8 and 8:6:6, w/w%) of anhydrous butterfat (ABF), palm stearin (PS) and flaxseed oil (FSO, omega-3) via lipase-catalyzed interesterification reaction. Their flavor characteristic was investigated using electronic nose and SPME-GC/MS analysis. Each flavor pattern of ABF, FSO, MF668 and MF866 was significantly discriminated with first principal component score of 95.16% in PCA plot. In functional modified-butterfats analyzed with SPME-GC/MS, various volatile compounds such as aldehydes, ketones, acids, and alkanes were detected.