• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1627-1642
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• 2021

This study aims to evaluate physical fitness according to the bone age of youth, and ultimately provide basic data for balanced development of youth through physical fitness standard indicators according to the bone age. A total of 730 youth aged 11 to 13 years in bone age and 11 to 13 years in chronological age were selected as subjects; and after taking X-ray films to calculate the bone age, they were evaluated by using the TW3 method. A total of 2 components in physique, which were stature and weight, were measured using a stadiometer(Hanebio, Korea, 2021) and Inbody 270(Biospace, Korea, 2019). A total of 7 components in physical fitness were measured as well, which included muscular strength (Hand Grip Strength), balance (Bass Stick Test), agility (Plate Tapping), power (Standing Long Jump), flexibility (Sit&Reach), muscular endurance (Sit-Up), and cardiovascular endurance (Shuttle Run). Descriptive statistics and independent t-test were conducted for data processing using the SPSS PC/Program(Version 26.0), and it was considered significant at the level of p< .05. The results of this study may be summarized as follow. First, the result of comparing the bone age and the chronological age of 11 to 13 years old in physical fitness, males showed significant difference in muscular strength, power, muscular endurance, and cardiovasular endurance. In females, muscular strength, balance, agility, power, flexibility, muscular endurance, and cardiovascular endurance showed significant difference. Second, physical fitness standard indicators were presented for each gender and age (11-13 years old) of youth according to the bone age; and based on this, physical fitness standard indicators, which are basic data for physical fitness evaluation according to the bone age of youth, were presented.

• Journal of the Korean Applied Science and Technology
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• v.39 no.1
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• pp.63-73
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• 2022

The aim of this study was to cluster according to the bone age of elementary school students in order to analyze the physique, physical fitness, and skeletal maturation of each cluter group and to provide basic data for the balanced development of elementary school students through data analysis. The subjects of this study were 2243 students aged 8 to 13 years, and the skeletal maturation were calculated by applying them to the TW3 method score conversion table after the X-ray films were taken. A total of 2 components in physique were measured using a stadiometer(Hanebio, Korea, 2021) and the Inbody 270(Biospace, Korea, 2019), and a total of 7 components in physical fitness, which included muscular strength(Hand Grip Strength), balance(Bass Stick Test), agility(Plate Tapping), power(Standing Long Jump), flexibility(Sit&Reach), muscular endurance(Sit-Up), and cardiovascular endurance(Shuttle Run) were measured as well. K-Means clustering method, cross-tabulation analysis, and one-way variable analysis(ANOVA) were conducted for data processing using the SPSS PC/Program(Version 26.0) and Bristics Studio Tool, and it was considered significant at the level of p< .05. The results of this study may be summarized as follow. First, as a result of clustering using three components of skeletal maturation: retarded, normal, and advanced, cluster 1(Retarded) showed excellence in muscular strength, balance, and agility. cluster 2(Normal) showed poor flexibility, whereas cluster 3(Advanced) showed excellence in muscular strength. Second, as a result of analyzing the differences in physique according to the clustering of elementary school students by their individual characteristics, cluster 3(Advanced) showed excellence in height, weight, and body fat percentage. Third, as a result of analyzing the differences in physical fitness according to the clustering of elementary school students by their individual characteristics, cluster 3(Advanced) showed excellence in Hand Grip Strength(Left, Right), whereas cluster 1(Retarded) showed excellence in Bass Stick Test, and cluster 3(Advanced) showed excellence in Standing Long Jump.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.400-412
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• 2023

In this study, the biogeochemistry management (BGC-MAN) model was applied to North and South Korea pine and oak forest stands to evaluate the Net Primary Productivity (NPP), an indicator of forest ecosystem productivity. For meteorological information, historical records and East Asian climate scenario data of Shared Socioeconomic Pathways (SSPs) were used. For vegetation information, pine (Pinus densiflora) and oak(Quercus spp.) forest stands were selected at the Gwangneung and Seolmacheon in South Korea and Sariwon, Sohung, Haeju, Jongju, and Wonsan, which are known to have tree nurseries in North Korea. Among the biophysical information, we used the elevation model for topographic data such as longitude, altitude, and slope direction, and the global soil database for soil data. For management factors, we considered the destruction of forests in North and South Korea due to the Korean War in 1950 and the subsequent reforestation process. The overall mean value of simulated NPP from 1991 to 2100 was 5.17 Mg C ha^-1, with a range of 3.30-8.19 Mg C ha^-1. In addition, increased variability in climate scenarios resulted in variations in forest productivity, with a notable decline in the growth of pine forests. The applicability of the BGC-MAN model to the Korean Peninsula was examined at a time when the ecosystem process-based models were becoming increasingly important due to climate change. In this study, the data on the effects of climate change disturbances on forest ecosystems that was analyzed was limited; therefore, future modeling methods should be improved to simulate more precise ecosystem changes across the Korean Peninsula through process-based models.