• Environmental and Resource Economics Review
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• v.29 no.4
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• pp.419-442
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• 2020

The majority of the natural gas demand in South Korea is mainly determined by the heating demand. Accordingly, there is a distinct seasonality in which the gas demand increases in winter and decreases in summer. Moreover, the degree of sensitiveness to temperature on gas demand has changed over time. This study firstly introduces changing temperature response function (TRF) to capture effects of changing seasonality. The temperature effect (TE), estimated by integrating temperature response function with daily temperature density, represents for the amount of gas demand change due to variation of temperature distribution. Also, this study presents an innovative way in forecasting daily temperature density by employing functional principal component analysis based on daily max/min temperature forecasts for the five big cities in Korea. The forecast errors of the temperature density and gas demand are decreased by 50% and 80% respectively if we use the proposed forecasted density rather than the average daily temperature density.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.1003-1013
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• 2021

Thioredoxin (TRX) protein is an antioxidant responsible for reducing other proteins by exchanging cysteine thiol-disulfide and is also known for its anti-allergic and anti-aging properties. On the other hand, epidermal growth factor (EGF) is an important material used in the cosmetics industry and an essential protein necessary for dermal wound healing facilitated by the proliferation and migration of keratinocytes. EGF also assists in the formation of granulation tissues and stimulates the motility of fibroblasts. Hence, genetically modified soybeans were developed to overexpress these industrially important proteins for mass production. A single-dose oral-toxicity-based study was conducted to evaluate the potential toxic effects of TRX and EGF proteins, as safety assessments are necessary for the commercial use of seed-specific protein-expressing transgenic soybeans. To achieve this rationale, TRX and EGF proteins were mass purified from recombinant E. coli. The single-dose oral-toxicity tests of the TRX and EGF proteins were carried out in six-week old male and female Institute of Cancer Research (ICR) mice. The initial evaluation of the single-dose TRF and EGF treatments was based on monitoring the toxicity signatures and mortality rates among the mice, and the resultant mortality rates did not show any specific clinical symptoms related to the proteins. Furthermore, no significant differences were observed in the weights between the treatment and control groups of male and female ICR mice. After 14 days of treatment, no differences were observed in the autopsy reports between the various treatment and control groups. These results suggest that the minimum lethal dose of TRX and EGF proteins is higher than the allowed 2,000 mg·kg^-1 limit.

• Korean Journal of School Psychology
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• v.16 no.3
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• pp.433-451
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• 2019

This study aimed to develop and validate the Classroom Problem Behavior Scale - Elementary School Version (CPBS-E) measure which is unique to classroom problem behavior exhibited by Korean elementary school students. The focus was on developing a universal screening instrument designed to identify and provide intervention to students who are at-risk for severe social-emotional and behavioral problems. Items were initially drawn from the literature, interviews with elementary school teachers, common office discipline referral measures used in U.S. elementary schools, penalty point systems used in Korean schools, 'Green Mileage', and the Inventory of Emotional and Behavioral Traits. The content validity of the initially developed items was assessed by six classroom and subject teachers, which resulted in the development of a preliminary scale consisting of 63 two-dimensional items (i.e., Within Classroom Problem Behavior and Outside of Classroom Problem Behavior), each of which consisted of 3 to 4 factors. The Within Classroom Problem Behavior dimension consisted of 4 subscales (not being prepared for class, class disruption, aggression, and withdrawn) and the Outside of Classroom Problem Behavior dimension consisted of 3 subscales (rule-violation, aggression, and withdrawn). The CPBS-E was pilot tested on a sample of 154 elementary school students, which resulted in reducing the scale to 23 items. Following the scale revision, the CPBS-E was validated on a sample population of 209 elementary school students. The validation results indicated that the two-dimensional CPBS-E scale of classroom problem behavior was a reliable and valid measure. The test-retest reliability was stable at above .80 in most of the subscales. The CPBS-E measure demonstrated high internal consistency of .76-.94. In examining the criterion validity, the scale's correlation with the Teacher Observation of Classroom Adaptation-Checklist (TOCA-C) was high and the aggression and withdrawn subscales of the CPBS-E demonstrated high correlations with externalization and internalization, respectively, of the Child Behavior Checklist - Teacher Report Form CBCL-TRF). In addition, the factor structure of the CPBS-E scale was examined using the structural equation model and found to be acceptable. The results are discussed in relation to implications, contributions to the field, and limitations.

• Journal of Life Science
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• v.19 no.10
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• pp.1463-1467
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• 2009

Telomeres, comprised of tandem repeats of TTAGGG sequences, are special nucleoprotein structures that protect and stabilize chromosome ends. These structures form the crux of the telomere concept of aging, senescence and genomic instability. The classic terminal restriction fragment (TRF) analysis to quantify the amount of telomeric DNA is disadvantageous in species containing ultra long telomeres like in mice (100Kb). In this study, we used a more sensitive quantitative fluorescence in situ hybridization (Q FISH) technique to quantify telomeric DNA, and used it as a biological aging marker in mice. 12 litters each of Senescence-Resistant (SAMR1) and -Prone (SAMP1) known as senescence accelerated mouse strains were purchased from Central Lab, Animal Inc. We quantified the amount of telomeric DNA using telomere specific DNA probes on the two strains of male mice at 8 weeks, 18 weeks and 26 weeks of age. The amount of telomeric DNA correlated with aging and age associated changes in body and organ weight between SAMR1 and SAMP1 strains of mice. These data suggest the usefulness of the amount of telomeric DNA as a biological aging marker in human aging studies.

• Journal of Climate Change Research
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• v.4 no.4
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• pp.305-316
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• 2013

The purpose of this study is to monitor the flux of $CO_2$ between the atmosphere and forest. The main research activities are conducted at Taehwa Mt. (Gangju, Kyeonggi, Korea), The Taehwa site is located 60 km north-east from the center of Seoul Metropolitan Area. The TRF flux tower is in the middle of a Korean Pine (Pinus koraiensis) plantation ($400m{\times}400m$), surrounded by a mixed forest. Eddy covariance method was used for $CO_2$ flux above the forest. $CO_2$ flux was measured from September to November 2011 and March to June 2012. It was found that $CO_2$ fluxes were observed between the atmosphere and forest. $CO_2$ was absorbed by plants through photosynthesis during the day and released during the night. $CO_2$ flux were respectively observed 0.7~0.2, 0.5~0.1, $0.3{\sim}0.1mgCO_2m^{-2}s^{-1}$ in Septem- ber, October, November 2011. $CO_2$ fluxes released by plants in the early morning(00:00~07:30h) and evening(18:00~24:00h) time. But $CO_2$ was absorbed by plants through photosynthesis in the day time(08:00~7:30h).