• Food Science of Animal Resources
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• v.25 no.3
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• pp.322-327
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• 2005

This study was intended to provide basic information which might be useful in increasing added values to the pork from Korean native black pigs (KNP), through comparative evaluation on carcass characteristics and meat qualities between KNP and four exotic breed groups including Duroc (DD), Landrace (LL), Yorkshire (YY), and LYD-cross (1/4LL 1/4YY, 1/2DD), and the results were summarized as follows. Live weight carcass weight, dressed meat weight, skin weight, fat weight and bone weight of KNP were significantly (p<0.05) lower than those of DD, LL, YY and LYD-cross. Carcass yield and dressed meat yield were also significantly (p<0.05) lower in KNP than other 4 groups, however, total fat, skin, bone, kidney and kidney fat in percentage were significantly (p<0.05) higher for KNP than others. Dressed meat yield was highest for YY, followed by LYD-cross and KNP. Weight of belly was 6.12, 9.43, and 9.52 kg for KNP, YY and LYD-cross, respectively. Percent belly of KNP was $11.11\%$ while other groups ranged from 11.5 to $12.2\%$ Shear force value was not different among the treatments. KNP had significantly (p<0.05) lower water holding capacity (WHC), and cooking loss, but significantly (p<0.05) higher in juiciness comparatively. KNP had significantly (p<0.05) higher $a^{*}$ value while DD had significantly (p<0.05) lower than other breeds.

• Journal of Educational Research in Mathematics
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• v.25 no.1
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• pp.21-58
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• 2015

The aim of this study is to look into the didactical background for teaching proportional reasoning in elementary school mathematics and offer suggestions to improve teaching proportional reasoning in the future. In order to attain these purposes, this study extracted and examined key ideas with respect to the didactical background on teaching proportional reasoning through a theoretical consideration regarding various studies on proportional reasoning. Based on such examination, this study compared and analyzed textbooks used in the United States, the United Kingdom, and South Korea. In the light of such theoretical consideration and analytical results, this study provided suggestions for improving teaching proportional reasoning in elementary schools in Korea as follows: giving much weight on proportional reasoning, emphasizing multiplicative comparison and discerning between additive comparison and multiplicative comparison, underlining the ratio concept as an equivalent relation, balancing between comparisons tasks and missing value tasks inclusive of quantitative and qualitative, algebraic and geometrical aspects, emphasizing informal strategies of students before teaching cross-product method, and utilizing informal and pre-formal models actively.

• Journal of Environmental Science International
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• v.22 no.2
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• pp.151-161
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• 2013

The assessment of personal exposure is a critical component in population-based epidemiologic studies of air pollution. This study was conducted to apply and compare the four exposure estimation methods of individual-level to air pollution concentration in a cohort including 2,283 subjects in Gwangyang, Korea. Individual-level exposure of air pollution were estimated using multiple approaches, including average across all monitors, nearest monitor, and spatial interpolation by inverse distance weighting and kriging. The mean concentrations of $PM_{10}$, $NO_2$, $SO_2$, CO, $O_3$ by four exposure estimation methods were slightly different but not significantly different from each other. Cross-validation showed that kriging was more accurate than other exposure estimation methods because kriging has probably predicted individual exposure levels equivalent to residential locations after estimating the parameters of a model according to the spatial surface of air pollution concentration. These data support that spatial interpolation methods may provide better estimates than selecting the value from the nearest monitor and averaging across values from all monitors by reflecting spatial attributes of air pollution on personal level.

• Journal of the Korean Magnetics Society
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• v.26 no.2
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• pp.67-69
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• 2016

Recently, cost of rare-earth magnets has been raised, because rare-earth magnets are monopolized and the export is also regulated in China. For this reason, the induction motor is operated without the rare-earth magnets. The efficient development of induction motor is more important for economical scheme. A torque of the induction motor is computed and the correlation between dimension and resistance of the squirrel cage rotor is investigated. Also, the correlation between leakage reactance and torque was analyzed with respect to the same dimension of rotor with different shapes. Therefore, this paper proposes the method of improvement for squirrel cage rotor.

• Journal of Electrochemical Science and Technology
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• v.6 no.3
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• pp.106-110
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• 2015

This study investigates Cu(II) complexes of cyclam, propylene cross-bridged cyclam (PCB-cyclam), and propylene cross-bridged cyclam diacetate (PCB-TE2A) as homogeneous electrocatalysts for CO₂ reduction in comparison with Ni(II)-cyclam. It is found that Cu(II)-cyclam can catalyze CO₂ reduction at the potential close to its thermodynamic value (0.75 V vs. Ag/AgCl) in tris-HCl buffer (pH 8.45) on a glassy carbon electrode. Cu(II)-cyclam, however, suffers from severe demetalation due to the insufficient stability of Cu(I)-cyclam. Cu(II)-PCB-cyclam and Cu(II)-PCB-TE2A are revealed to exhibit much less demetalation behavior, but poor CO₂ reduction activities as well. The inferior electrocatalytic ability of Cu(II)-PCB-cyclam is ascribed to its redox potential that is too high for CO₂ reduction, and that of Cu(II)-PCB-TE2A to the steric hindrance preventing facile contact with CO₂ molecules. This study suggests that in addition to the redox potential and chemical stability, the stereochemical aspect has to be considered in designing efficient electrocatalysts for CO₂ reduction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.413-419
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• 2011

This study was conducted to determine the physicochemical properties of a giant embryo rice 'P47JB-4-B-5-B' derived from the cross between 'P47', a mutant of 'Hwayoung' induced by T-DNA insertion, and 'Junam'. The grain appearance and chemical components of the embryo were analyzed and compared with a donor cultivar, 'Hwayoung'. The proportion of embryo weight to grain weight of 'P47 JB-4-B-5-B' was 2.2 times heavier (6.7%) than that (3.1%) of 'Hwayoung'. Total free amino acid content (75.81 mg/100 g) of 'P47JB-4-B-5-B' was 2.1 times higher than that of 'Hwayoung'. The GABA content in brown rice was 14.06 mg/100 g in 'P47JB-4-B-5-B' and 6.8 mg/100 g in 'Hwayoung'. Especially, the GABA content in brown rice of 'P47JB-4-B-5-B' remarkably increased (about 33 times from 1.48 mg to 44.81 mg/100 g) 2 days after germination. Continuous frequency distributions and transgressive segregation in embryo length and width were observed in the $F_2$ population of the cross between 'P47' and 'Cheongcheong', indicating that the giant embryo was controlled by quantitative trait loci. However, embryo length and width demonstrated high broad sense heritability, implying that giant embryonic traits could be selected in earlier generations in comparison with other quantitative traits.

• Journal of Korean Library and Information Science Society
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• v.46 no.1
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• pp.345-372
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• 2015

Most academic journals in the world today typically require submission of journal article titles in English. However, most authors and reviewers are insensitive to the fact that cultural differences at a national level exist in writing titles. In this paper, journal article titles that have been published in the United States and Korea were compared in order to find cross-national cultural characteristics in these titles. To conduct this study, sample titles in the field of social sciences were obtained from two bibliographic databases-Scopus and RISS. A frequency count on number of variables was used: length of title, types of titles and n-gram phrases. In addition, a variety of similarities and differences found from this study including the type of words and phrases that Korean authors tend to favor in journal articles. The results showed that there is a considerable amount of cultural related variability in the construction of journal article titles. This study suggests that cross national characteristics of journal article titles should be emphasized in the future.

• Research in Community and Public Health Nursing
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• v.27 no.2
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• pp.95-105
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• 2016

Purpose: This study examined the characteristics differences associated with 1-year continuous smoking abstinence in Korean young adult and middle-aged male workers. Methods: 'Korea National Health and Nutrition Examination Survey (KNHANES)' is an ongoing surveillance system that assesses the health and nutritional status of Koreans. For a secondary analysis of cross-sectional data from KNHANES VI-1, this study selected 683 Korean male workers as a subpopulation, who were young adult or middle-aged. The subpopulation was composed of success or failure group of 1-year continuous smoking abstinence. Binomial logistic regression analysis was performed. Results: Success group was more likely to be older, live in urban areas, rate their health status as excellent or good, and have ever been diagnosed with hypertension than failure group. Additionally, Success group was less likely to have used electronic cigarettes (e-cigarettes), drink more than once a month, and have been exposed to secondhand smoking in workplace within a week. Conclusion: Developing smoking cessation programs requires consideration of resources in rural areas, promoting self-efficacy, restricting e-cigarettes and drinking, and promoting a smoke-free workplace.

• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.589-601
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• 2016

Sea surface currents were estimated by applying the Maximum Cross Correlation (MCC), Zero-mean Sum of Absolute Distances (ZSAD), and Zero-mean Sum of Squared Distances (ZSSD) algorithms to Himawari-8/Advanced Himawari Imager (AHI) thermal infrared channel data, and the comparative analysis was performed between the results of these algorithms. The sea surface currents of the Kuroshio Current region that were retrieved using each algorithm showed similar results. The ratio of errors to the total number of estimated surface current vectors had little difference according to the algorithms, and the time required for sea surface current calculation was reduced by 24% and 18%, relative to the MCC algorithm, for the ZSAD and ZSSD algorithms, respectively. The estimated surface currents were validated against those from satellite-tracked surface drifter and altimeter data, and the accuracy evaluation of these algorithms showed results within similar ranges. In addition, the accuracy was affected by the magnitude of brightness temperature gradients and the time interval between satellite image data.

• Journal of Korea Water Resources Association
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• v.48 no.6
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• pp.439-449
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• 2015

In this study, reliable future runoff projections based on RCPs for Yongdam dam watershed was performed using SWAT model, which was validated by k-fold cross validation method, and investigated the factors that cause the differences with respect to runoff projections between this study and previous studies. As a result, annual average runoff compared to baseline runoff would increase 17.7% and 26.1% in 2040s and 2080s respectively under RCP8.5 scenario, and 21.9% and 44.6% in 2040s and 2080s respectively under RCP4.5 scenario. Comparing the results to previous studies, minimum and maximum differences between runoff projections over different studies were 10.3% and 53.2%, even though runoff was projected by the same rainfall-runoff model. SWAT model has 27 parameters and physically based complex structure, so it tends to make different results by the model users' setting. In the future, it is necessary to reduce the cause of difference to generate standard runoff scenarios.