• Journal of the Korean Geographical Society
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• v.44 no.1
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• pp.1-16
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• 2009

This study aims to classify climate zones using Empirical Orthogonal Function and clustering analyses considering both air temperature and rainfall features in South Korea. When examining climatic characteristics of air temperature and rainfall by seasons, the distribution of air temperature is affected by topography and latitude for all seasons in South Korea. The distribution of rainfall demonstrated that the Yeongdong area, the southern coastal area and Jeju island have higher rainfall while the central area in Gyeongsangbuk-do is the least rainfall area. Clustering analyses of average linkage method and Ward's method was carried out using input variables derived from principal component scores calculated through Empirical Orthogonal Function analysis for air temperature and rainfall. Ward's method showed the best result of classification of climate zones. It was well reflected effects of topography, latitude, sea, the movement of surface pressure systems, and an administrative district.

• YAKHAK HOEJI
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• v.52 no.5
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• pp.345-354
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• 2008

This study was designed to investigate the anti-diabetic effect and mechanism of Korean red ginseng extract through transcriptomics in C57BL/KsJ db/db mice. The db/db mice were randomly divided into six groups: diabetic control group (DC), red ginseng extract low dose group (RGL, 100 mg/kg), red ginseng extract high dose group (RGH, 200 mg/kg), metformin group (MET, 300 mg/kg), glipizide group (GPZ, 15 mg/kg) and pioglitazone group (PIO, 30 mg/kg), and treated with drugs once per day for 10 weeks. At the end of treatment, we measured blood glucose, insulin, hemoglobin A1c (HbA1c), triglyceride (TG), adiponectin, leptin, non-esterified fatty acid (NEFA). RGL-treated group lowered the blood glucose and HbA1c levels by 19.6% and 11.4% compared to those in diabetic control group. In addition, plasma adiponectin and leptin levels in RGL-treated groups were increased by 20% and 12%, respectively, compared to those in diabetic control. Morphological analyses of liver, pancreas and epidydimal adipose tissue were done by hematoxylin-eosin staining, and pancreatic islet insulin and glucagon levels were detected by double-immunofluorescence staining. RGL-treated group revealed higher insulin contents and lower glucagon contents compared to diabetic control. To elucidate an action mechanism of Korean red ginseng, DNA microarray analyses were performed in liver and fat tissues, and western blot and RT-PCR were conducted in liver for validation. According to hierarchical clustering and principal component analysis of gene expression Korean red ginseng treated groups were close to metformin treated group. In summary, Korean red ginseng lowered the blood glucose level through protecting destruction of islet cells and shifting glucose metabolism from hepatic glucose production to glucose utilization and improving insulin sensitivity through enhancing plasma adiponectin and leptin levels.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.137-144
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• 2009

In this study, quantitative and pattern recognition analyses for the quality evaluation of Herba Epimedii using HPLC was developed. For quantitative analysis, five major bioactive constituents, hyperin, epimedin A, epimedin B, epimedin C, and icariin were determined. Analysis was carried out on Capcell pak $C_{18}$ column ($250{\time}4.6$ mm, 5 ${\mu}m$) with a mobile phase of mixture of acetonitrile and 0.1% formic acid, using UV detection at 270 nm. The linear behavior was observed over the investigated concentration range (2-50 ${\mu}g/mL;\;r_2\;>$ 0.99) for all analytes. The intraand inter-day precisions were lower than 4.3% (as a relative standard deviation, RSD) and accuracies between 95.1% and 104.4%. The HPLC analytical method for pattern recognition analysis was validated by repeated analysis of one reference sample. The RSD of intra- and inter-day variation of relative retention time (RRT) and relative peak area (RPA) of the 12 selected common peaks were below 0.8% and 4.7%, respectively. The developed methods were applied to analysis of twenty Herba Epimedii extract samples. Contents of hyperin, epimedin A, epimedin B, epimedin C, and icariin were calculated to be 0$\sim$0.79, 0.69$\sim$1.91, 0.93$\sim$9.58, 0.65$\sim$3.05, and 2.43$\sim$11.8 mg/g dried plant. Principal component analysis (PCA) showed that most samples were clustered together with the reference samples but several apart from the main cluster in the PC score plot, indicating differences in overall chemical composition between two clusters. The present study suggests that quantitative determination of marker compounds combined with pattern-recognition method can provide a comprehensive approach for the quality assessment of herbal medicines.

• Journal of Plant Biotechnology
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• v.49 no.1
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• pp.46-60
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• 2022

The genetic variability and population structure of apple mosaic virus (ApMV) have been studied; however, synonymous codon usage patterns influencing the survival rates and fitness of ApMV have not been reported. Based on phylogenetic analyses of 52 ApMV coat protein (CP) sequences obtained from apple, pear, and hazelnut, ApMV isolates were clustered into two groups. High molecular diversity in GII may indicate their recent expansion. A constant and conserved genomic composition of the CP sequences was inferred from the low codon usage bias. Nucleotide composition and relative synonymous codon usage (RSCU) analysis indicated that the ApMV CP gene is AU-rich, but G- and U-ending codons are favored while coding amino acids. This unequal use of nucleotides together with parity rule 2 and the effective number of codon (ENC) plots indicate that mutation pressure together with natural selection drives codon usage patterns in the CP gene. However, in this combination, selection pressure plays a more crucial role. Based on principal component analysis plots, ApMV seems to have originated from apple trees in Europe. However, according to the relative codon deoptimization index and codon adaptation index (CAI) analyses, ApMV exhibited the greatest fitness to hazelnut. As inferred from the results of the similarity index analysis, hazelnut has a major role in shaping ApMV RSCU patterns, which is consistent with the CAI analysis results. This study contributes to the understanding of plant virus evolution, reveals novel information about ApMV evolutionary fitness, and helps find better ApMV management strategies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.1
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• pp.8-19
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• 2023

Adzuki beans have gained popularity in recent years due to their health benefits. Breeding of Adzuki beans is less favorable than with other legumes due to low genetic diversity. This study aimed to evaluate the genetic diversity of 252 adzuki bean germplasms from China, Japan, and Korea using 18 agro-morphological parameters and comparing their performance to three prominent Korean cultivars: Geomguseul, Arari, and Chungjupat. Leaf shape, pod color, and seed coat color were among the qualitative traits that showed wide variations. The quantitative variables also showed wide variations among adzuki bean germplasms. Although there was no significant difference (p < 0.05), the average rate of germination declined in the order of Korean (91.44%) > Chinese (91.31%) > Japanese (87.47%) adzuki beans. Chinese adzuki beans needed fewer days to flower (DF, 58.22 days) and days to mature (DM, 107.13 days), which varied significantly compared to the Korean and Japanese adzuki beans (p < 0.05). The average number of pods per plant (PPP) and one-hundred seeds weight (HSW) were higher in Japanese adzuki beans compared to the Korean and Chinese adzuki beans although the variation of each was not significant. Almost 29.76% of the accessions had early-blooming flowers, 3.97% were premature, 21.43% produced more PPP, and 3.97% yielded more SPP compared to control cultivars. Results of hierarchical cluster and principal component analyses revealed three clusters with significant variation in all quantitative variables except for RG (p < 0.05). The key factors in multivariate analyses were DF, DM, and HSW. Our study investigated the genetic diversity of adzuki bean accessions and identified ten early maturing and ten high PPP-yielding accessions. Our findings would help farmers and breeders to select the top-performing accessions that can provide them with various options.

• Journal of Korea Trade
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• v.27 no.3
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• pp.161-178
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• 2023

Purpose - purpose of this paper is to analyze the effects of the investment facilitation levels of 11 RCEP countries (excluding Myanmar, Brunei, and Laos due to lack of data) on China's outward foreign direct investments(OFDI) using balanced panel data from 2010 to 2019. Design/methodology - First, four investment facilitation measurement indicators (regulatory environment, infrastructure, financial market, ease of doing business) were selected,investment facilitation scores of the 11 countries were obtained using the principal component analysis, an investment gravity model was established with nine explanatory variables (investment facilitation level, market size, population, geographic distance, degree of opening, tax level, natural resources, whether the country is an APEC member or not, and whether a valid bilateral investment treaty with China has been concluded) were used to establish an investment gravity model, and regression analyses were conducted with OLS and system GMM. Findings - The results of the regression analyses showed that investment facilitation levels had the greatest effect on China's OFDI, all four first-level indicators had positive effects on China's OFDI, and among them, the institutional environment had the greatest effect. In addition, it was shown that explanatory variables such as market size, population, geographical distance, degree of openness, natural resources, and whether or not a valid bilateral investment treaty has been concluded would have positive effects on China's OFDI, while tax levels and APEC membership would impede China's OFDI to some extent. Originality/value - Since the Regional Comprehensive Economic Partnership (RCEPT) came into effect not long ago, there are not so many studies on the effects of investment facilitation levels of RCEP member states on China's OFDI, and the investment facilitation measurement index constructed in this paper is relatively systematic and scientific because it includes all the contents of investment facilitation related to the life cycle of company's foreign direct investments.

• Korean Journal of Environment and Ecology
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• v.26 no.6
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• pp.884-891
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• 2012

The characteristic of fish fauna and distribution by habitat type in the Yanghwa stream were investigated from August, 2008 to June, 2009. During the surveyed period, 30 species belonging 8 families were collected. And there were 10 Korea endemic species(33.3%), including Rhodeus uyekii et and so on. Dominant species was Rhodeus notatus, and subdominant species was Pseudorasbora parva. Dominant species according to habitat type was Pseudorasbora parva in Dam type pool and Channel conected pool, Pseudogobio esocinus(Run), Zacco platypus(Riffle), Rhodeus notatus(Side channel and Substrate type pool), Squalidus gracilis majimae(Meander type pool), and Carassius auratus(Channel unconnected pool), respectively. As a results of community analysis in the Yanghwa Stream, diversity, richness, and abundance indices showed relatively high values, indicating that studied stream have relatively stable community structure. Moreover, cluster and principal component analysis were divided by two groups(lotic and lentic habitats), suggest that species and individuals were different among habitat types.

• The Journal of Engineering Geology
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• v.22 no.2
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• pp.207-221
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• 2012

A statistical analysis of time series of water level at 27 groundwater monitoring wells was conducted to analyze the surface water-groundwater connectivity in the wide alluvial plains surrounding the Nakdong River, Korea. Change in groundwater level is strongly related to river water level, yielding an average cross-correlation coefficient of 0.601, which is much higher than that between rainfall and groundwater level (0.125). Principal component analysis of groundwater level indicates that wells in the study area can be classified into two groups: wells in Group A are located close to a river, have water levels closely related to river level, and generally show a large increase in groundwater level during heavy rainfall. On the other hand, wells in Group B located far from a river are relatively less related to river level. Including hydrologic and statistical analyses, geochemical analysis and temperature monitoring are additionally required to reveal the relationship between surface water level and groundwater level, and to assess the possibility of groundwater flooding.

• Food Science and Preservation
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• v.23 no.5
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• pp.727-737
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• 2016

This study was carried out to determine the descriptive sensory profile of oriental melon. The sensory profile of oriental melons (cultivated in Seonju, Kyungsangbuk-do) were used quantitative descriptive analyses and twelve trained panel developed the total forty sensory attributes related appearance, aroma, texture etc. Six appearances attributes and two aromas attributes were derived from whole oriental melon with skin. Five aromas, six tastes and six textures were derived from the mesocarp of oriental melon. And also, oriental melons were analyzed for pH, titratable acidity, solid soluble contents and weight. The weight, titratable acidity and soluble solid content of oriental melons showed significant differences according to samples. And also, in the sensory attributes of these samples by trained panel and consumer test, there were significant differences between organic cultivated samples and conventional cultivated samples. Based on principal component analysis of sensory attributes data by trained panel and consumer, oriental melons were primary separated along the first principal component, which accounted for 27.73% (trained panel test) and 19.82% (consumer test) of total variance (trained panel test; 58.36%, consumer test; 46.18%) between the samples farm, cultivation method, total acidity, sweet aroma, bitterness, etc. Generally, whole oriental melon with skin showed significant differences in the sensory attributes according to cultivation method and farms. But, the mesocarp and endocarp part showed not certainly differences in the sensory attributes between organic cultivated samples except conventional cultivated samples.

• Korean Journal of Remote Sensing
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• v.15 no.2
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• pp.91-105
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• 1999

Spatial data integration using multiple geo-based data sets has been regarded as one of the primary GIS application issues. As for this issue, several integration schemes have been developed as the perspectives of mathematical geology or geo-mathematics. However, research-based approaches for statistical/quantitative assessments between integrated layer and input layers are not fully considered yet. Related to this niche point, in this study, spatial data integration using multiple geoscientific data sets by known integration algorithms was primarily performed. For spatial integration by using raster-based GIS functionality, geological, geochemical, geophysical data sets, DEM-driven data sets and remotely sensed imagery data sets from the Ogdong area were utilized for geological thematic mapping related by mineral potential mapping. In addition, statistical/quantitative information extraction with respective to relationships among used data sets and/or between each data set and integrated layer was carried out, with the scope of multiple data fusion and schematic statistical assessment methodology. As for the spatial integration scheme, certainty factor (CF) estimation and principal component analysis (PCA) were applied. However, this study was not aimed at direct comparison of both methodologies; whereas, for the statistical/quantitative assessment between integrated layer and input layers, some statistical methodologies based on contingency table were focused. Especially, for the bias reduction, jackknife technique was also applied in PCA-based spatial integration. Through the statistic analyses with respect to the integration information in this case study, new information for relationships of integrated layer and input layers was extracted. In addition, influence effects of input data sets with respect to integrated layer were assessed. This kind of approach provides a decision-making information in the viewpoint of GIS and is also exploratory data analysis in conjunction with GIS and geoscientific application, especially handing spatial integration or data fusion with complex variable data sets.