• Journal of Astronomy and Space Sciences
• /
• v.38 no.4
• /
• pp.229-236
• /
• 2021

We present for the first time the characteristics of upper atmospheric horizontal winds over the Korean Peninsula. Winds and their variability are derived using four-year measurements by the Korea Astronomy and Space Science Institute (KASI) meteor radar. A general characteristic of zonal and meridional winds is that they exhibit distinct diurnal and seasonal variations. Their changes indicate sometimes similar or sometimes different periodicities. Both winds are characterized by either semi-diurnal tides (12 hour period) and/or diurnal tides (24 hour period) from 80-100 km. In terms of annual change, the annual variation is the strongest component in both winds, but semi-annual and ter-annual variations are only detected in zonal winds.

• Clinical and Experimental Reproductive Medicine
• /
• v.49 no.3
• /
• pp.196-201
• /
• 2022

Objective: This prospective consecutive study investigated the variation in sperm DNA fragmentation (SDF) in multiple semen samples from patients with cancer. Methods: Eighty-one patients with various cancers underwent multiple semen collections on 3 consecutive days for sperm cryopreservation prior to cancer treatment. A commercial Halosperm kit was used to measure SDF. Within- and between-subject coefficients of variation were estimated via random-effects analysis of variance to assess the consistency of semen parameters and SDF. Intraclass correlation coefficients (ICCs) were calculated to assess the magnitude of the between-subject component of variance relative to the total variance. Results: The volume of semen in the day-2 and day-3 samples was significantly lower compared with the day-1 sample. Most parameters showed high ICC values, suggesting that within-subject fluctuations were small relative to the between-subject variability. The highest ICC values were identified for the SDF (ICC, 0.68; 95% confidence interval [CI], 0.45-0.84) and semen volume (ICC, 0.67; 95% CI, 0.45-0.84). Conclusion: Our findings showed that repeated ejaculates from patients with cancer had stable SDF levels.

• Journal of Life Science
• /
• v.18 no.3
• /
• pp.291-297
• /
• 2008

We investigated whether 1) the combined capsaicin (75 mg), sesamin (30 mg), and L-carnitine (900 mg) (CCSC) ingestion enhances autonomic nervous system (ANS) activities including thermogenic sympathetic activity as energy metabolic modulator, 2) ${\beta}_3-AR$ polymorphism of each subject influences with ANS activity. Seven healthy males $(22.0{\pm}0.5\;yr)$ volunteered for this study. The cardiac autonomic nervous activities evaluated by means of heart rate variability of power spectral analysis were continuously measured during 5 min every 30 min for total 120 min resting condition with CCSC or placebo oral administration chosen at random. The results indicated that, there are not $Arp/Arg^{64}$ variants of the ${\beta}_3-AR$ genotypes in our subjects. There were not also significant differences in heart rate during rest between both trials. The difference of ANS activity did not reach the statistical significance between both trials. However, the significant improvement showed TOTAL power, HF component, and the indices of SNS and PNS activities before and at 30 min after CCSC ingestion (p<0.05, respectively). In conclusions, although each component of combined CCSC is associated with lipolysis and/or fat oxidation, the combined CCSC consumption is not influenced in stimulation of thermogenic sympathetic activity as modulator of energy metabolism. In rather, our results suggested that CCSC ingestion improves the balance of both SNS and PNS activities. Therefore, it will be considered many combined nutrient components for ergogenic and/or lipolysis effects as well as genetic variants affecting ANS activity in further studies.

• Education of Primary School Mathematics
• /
• v.17 no.2
• /
• pp.95-111
• /
• 2014

The purpose of this study is to determine the relationship between metacognition and math creative problem solving ability. Specific research questions set up according to the purpose of this study are as follows. First, what relation does metacognition has with creative math problem-solving ability of mathematically gifted elementary students? Second, how does each component of metacognition (i.e. metacognitive knowledge, metacognitive regulation, metacognitive experiences) influences the math creative problem solving ability of mathematically gifted elementary students? The present study was conducted with a total of 80 fifth grade mathematically gifted elementary students. For assessment tools, the study used the Math Creative Problem Solving Ability Test and the Metacognition Test. Analyses of collected data involved descriptive statistics, computation of Pearson's product moment correlation coefficient, and multiple regression analysis by using the SPSS Statistics 20. The findings from the study were as follows. First, a great deal of variability between individuals was found in math creative problem solving ability and metacognition even within the group of mathematically gifted elementary students. Second, significant correlation was found between math creative problem solving ability and metacognition. Third, according to multiple regression analysis of math creative problem solving ability by component of metacognition, it was found that metacognitive knowledge is the metacognitive component that relatively has the greatest effect on overall math creative problem-solving ability. Fourth, results indicated that metacognitive knowledge has the greatest effect on fluency and originality among subelements of math creative problem solving ability, while metacognitive regulation has the greatest effect on flexibility. It was found that metacognitive experiences relatively has little effect on math creative problem solving ability. This findings suggests the possibility of metacognitive approach in math gifted curricula and programs for cultivating mathematically gifted students' math creative problem-solving ability.

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

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.16 no.4
• /
• pp.345-352
• /
• 2010

The objective of this paper is to explore the short-term variability of water temperature and chlorophyll a (Chl-a) derived from in-situ and satellite data (NOAA, Sea WiFS and QuikScat) in the upwelling region of the southeastern part of Korean Peninsula in June and August, 2007. Particularly we focused on the spatial variability of sea surface temperature(SST) and Chl-a in the East Korean Warm Current region. In the results of the in-situ data, the peaks of Chl-a in june was shown at a depth of 50m The peaks of Chl-a in August was shown at a depth of 10m at the stations 4 and 5 near the land, and a depth of 30m at the other stations. The Chl-a concentrations in August were also lower than those in june except for station 5. As a result, the peaks of Chl-a in August occurred at a depth of 20~40 m shallower than those of Chl-a in june. This indicates that the nutrient-rich water within the mixed layer depth may be immediately supplied by the coastal upwelling, which is due to the southerly component of wind. The relationship between SST and Chl-a showed a negative correlation, and the high concentration of Chl-a occurred in the cold water area. The southerly wind and the East Korean Warm Current influenced a remarkable offshore movement of the cold water and Chl-a near the coastal area.

• Asian-Australasian Journal of Animal Sciences
• /
• v.31 no.2
• /
• pp.167-179
• /
• 2018

Objective: The aim of this study was to create a set of microsatellite markers with high polymorphism for the genetic monitoring and genetic structure analysis of local goose populations. Methods: Novel microsatellite markers were isolated from the genomic DNA of white Roman geese using short tandem repeated probes. The DNA segments, including short tandem repeats, were tested for their variability among four populations of geese from the Changhua Animal Propagation Station (CAPS). The selected microsatellite markers could then be used to monitor genetic variability and study the genetic structures of geese from local geese farms. Results: 14 novel microsatellite loci were isolated. In addition to seven known loci, two multiplex sets were constructed for the detection of genetic variations in geese populations. The average of allele number, the effective number of alleles, the observed heterozygosity, the expected heterozygosity, and the polymorphism information content were 11.09, 5.145, 0.499, 0.745, and 0.705, respectively. The results of analysis of molecular variance and principal component analysis indicated a contracting white Roman cluster and a spreading Chinese cluster. In white Roman populations, the CAPS populations were depleted to roughly two clusters when K was set equal to 6 in the Bayesian cluster analysis. The founders of private farm populations had a similar genetic structure. Among the Chinese geese populations, the CAPS populations and private populations represented different clads of the phylogenetic tree and individuals from the private populations had uneven genetic characteristics according to various analyses. Conclusion: Based on this study's analyses, we suggest that the CAPS should institute a proper breeding strategy for white Roman geese to avoid further clustering. In addition, for preservation and stable quality, the Chinese geese in the CAPS and the aforementioned proper breeding scheme should be introduced to geese breeders.

• Journal of Wetlands Research
• /
• v.13 no.1
• /
• pp.1-11
• /
• 2011

A chronic drought stress has been imposed during non-rainy season(from winter to spring) since 1990s. We faced the most significant water crisis in 2001, and the drought was characterized by sultry weather and severe drought on a national scale. It has been widely acknowledged that the drought related damage is 2-3 times serious than floods. In the list of the world's largest natural disaster compiled by NOAA, 4 of the top 5 disasters are droughts. And according to the analysis from the NDMC report, the drought has the highest annual average damage among all the disasters. There was a very serious impact on the economic such as rising consumer price during the 2001 spring drought in Korea. There has been flood prevention measures implemented at national-level but for mitigation of droughts, there are only plans aimed at emergency (short-term) restoration rather than the comprehensive preventive measures. In addition, there is a lack of a clear set of indicators to express drought situation objectively, and therefore it is important and urgent to begin a systematic study. In this study, a nonstationary downscaling model using RCM based climate change scenario was first applied to simulate precipitation, and the simulated precipitation data was used to derive Standardized Precipitation Index (SPI). The SPI under climate change was used to evaluate the spatio-temporal variability of drought through principal component analysis at three different time scales which are 2015, 2045 and 2075. It was found that spatio-temporal variability is likely to modulate with climate change.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.7 no.2
• /
• pp.43-50
• /
• 2002

This study focused on variability of the sea water temperatures observed off the Dangjin Power Plant in the central west coast of Korea for the period of 1998-1999. Spatial averaged temperature shows the annual range of $20.3^{\circ}C$, with minimum of $3.3^{\circ}C$ in February and maximum of $23.6^{\circ}C$ in August. Horizontal distribution patterns are seasonally reversing: The temperatures are increasing toward inshore of the period of April to October, while they are increasing toward of offshore for the rest of year. Spectral analyses of temperature records show significant peaks at M2 and S2 tidal periods, since the water movement in the study area is influenced by strong tide. The responses of temperature variations to tidal phase show different seasonal characteristics: The temperatures are increasing at flood phases in winter and ebb phases in summer. Amplitudes of the components at M2 and S2 periods are $0.8^{\circ}C\;and\;0.5^{\circ}C$, accounting for 70-80% of daily variation. Coherency analyses between non-tidal components of temperature and wind speed show that in summer, northerly wind components significantly coherent with temperature at 2.8 days period, while in winter, southerly wind component is coherent with 2.4 days period, with 0.6 and 0.7 day phase-lags, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.1
• /
• pp.208-215
• /
• 2020

This study investigated the relationship among gait variables and physical fitness variables for Korean elderly people. Two hundred elderly people aged 65 to 85, (100 men and 100 women) participated in this study. They performed senior fitness test consisting of 6 tests, 3 additional physical tests (vertical jump, one leg stand, and grip force), body composition measures, and gait test. The gait test used shoes having an inertia measurement device in the outer-soles. The results indicated that the stride length, 6-min walking, lean body mass, and dumbbell curls were significantly affected by age (the above 75 group vs. the below 75 group). Among 33 measured parameters, the principal component analysis (PCA) revealed five PCs such as gait characteristics, physical features, gait variability, and fitness levels. In addition, the correlation analysis showed that the preferred walking speed was significantly, positively associated with stride length and single support time, whereas it was negatively associated with double support time and gait variability.(Ed note: please confirm my modification) In conclusion, sarcopenia should be avoided in elderly people, and resistance exercise is highly recommended to help elderly people maintain their gait ability.