• Journal of the Korean Society of International Agriculture
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• v.31 no.4
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• pp.428-436
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• 2019

As the main objective of rice breeding programs, rice eating quality is one of critical factors directly determining the market price and the consumer preference. However, the genetic complexity of eating quality and the difficulty in accurate evaluation often constrain improvement of the eating quality in rice breeding programs. In addition, given that the rice eating quality of current cultivars has already reached some high-level, diversifying of genetic resources are demanded more than ever to improve the rice eating quality. In this study, we developed a recombinant inbred lines (RILs) population derive from Wandoaengmi6, a japonica-type Korean weedy rice with high eating quality and a high degree of glossiness of cooked rice. Year-to-year correlations between the traits in three years were shown normal distribution for major agronomic traits and physicochemical characteristics. After evaluating tested traits related to eating quality procedure, a total of ten lines were ultimately selected from the population. Increasement of the taste of cooked rice (TA) and the overall eating quality (OE) were confirmed in the selected lines, which are caused by alleles derived from Wandoaengmi6 without any linkage drag. These results indicate that the utility of wide genomic resources in Korean landrace could be of application in various rice breeding programs and countermeasure to contribute to properly response to climate change.

• Korean Journal of Culture and Social Issue
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• v.14 no.4
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• pp.19-37
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• 2008

The youth unemployment issue has not shown any improvement in years. The purpose of this study was to observe how employment issues affecting university students influence their life aims, self-efficacy, view of reality, view of the future, and life satisfaction. 239 students from three universities located in Seoul and Gyeonggi province were assessed through the instrument FLL and questions about employment issues, their life aims, life satisfaction and also their employment perspective. A total of 34 items of the FLL were divided through factor analysis into six higher life aims, self-love, family love and interpersonal aims, personal-financial aims, social-public aims, moral aims and political and ideological aims. Using Cluster analysis, three group profiles were found depending on the employment perspective such as a better view of reality, better self-efficacy, and better life satisfaction. A t-test was conducted in order to compare the two groups classified according to favorable or unfavorable employment perspectives. No significant differences existed between the groups in the perception of youth unemployment or in social-demographic factors, such as gender, age, and academic year. However, in life aims, the unfavorable group showed significantly higher interest in the domains of family love and interpersonal aims, personal -financial aims, and social-public aims than the favorable perspective group. Conversely, this group showed a significantly greater negative view of reality in most life domains, as it evaluated that its aims are more poorly achieved than the comparable group. Also, the unfavorable perspective group showed a lesser degree of self-efficacy in most life domains and the same in the category of life satisfaction, i.e., lesser satisfaction in all life domains except for family love, and moral aims. However, no significant difference existed between the groups in the view of the future. The results were discussed in relation to other social-cognitive factors for life satisfaction found in preceding studies.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.435-445
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• 2023

The aim of this study was to explore the effects of vinegar extract from seed of common buckwheat (Fagopyrum esculentum Moench) and seed of tartary buckwheat (F. tataricum Gaertner) on acute ethanol-induced hangover in Sprague-Dawley rats. Vinegar extract from buckwheat is rich choline, quercetin and its glycoside, rutin known as flavonoid antioxidants. The test extract containing buckwheat was proven to alleviate hangovers through a significant reduction in the concentration of alcohol and acetaldehyde in the context of an alcohol-induced hangover model. Hepatic alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities were significantly higher in buckwheat vinegar-treated rats than in ethanol-treated rats. Moreover, tartary buckwheat vinegar upregulated antioxidant enzyme such as superoxide dismutase and Catalase activities in liver tissues. These results suggest that buckwheat vinegar extract could alleviate ethanol-induced hangover symptoms by elevating activities related to hepatic ethanol-metabolizing enzymes against ethanol induced metabolites, and in particular, tartary buckwheat should be further developed to be a novel anti-hangover material.

• Korea Trade Review
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• v.48 no.3
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• pp.43-68
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• 2023

In this study, in relation to "Chapter 3 Support for Priority Purchase of Technology Development Products" of the 「Market Channel Support Act」, this study investigated the positive growth impact of technology development products subject to preferential purchase on small and medium sized enterprises. The data used for empirical verification is for 371 companies that obtained certification for technology development products subject to preferential purchase in 2016 and Data from SMEs were collected from 2017 to 2021, Sales, operating profit, and net profit was identified, and empirical verification. And conducted through statistical analysis to determine whether it had a positive effect on the growth factors of SMEs. In addition, data from 225 technology development product certification companies were collected, and empirical testing was conducted through t-test analysis on the change in growth factors before and after acquiring certification. As a result of statistical analysis, it was found that the total assets, certified sales, operating profit, and net profit, which are the growth factors of a company, are all positively affected according to the type of technology development product certification. However, in the case of authentication types, some authentications showed significant negative results. In addition, significant results were derived that after acquiring certification had a positive effect on growth factors than before acquiring certification. Consistent with this conclusion, I think that it is effective for technology development-based SMEs to enter the public procurement market and utilize the technology development product priority purchase policy for market exploitation and corporate growth. And the government should strengthen the market support policy to create demand so that SMEs can enter the procurement market and actively utilize the preferential purchase system, and come up with an improvement plan so that public institutions can actively utilize the preferential purchase system.

• Journal of the Korean Applied Science and Technology
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• v.41 no.2
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• pp.508-519
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• 2024

In this study, in order to evaluate the possibility of using Jubak as a functional cosmetic material, evaluation of antioxidant activity according to fractions and anti-wrinkle efficacy in CCD-986sk cells, a human fibroblast, were conducted. As a result of confirming the antioxidant activity by measuring ABTS⁺ radical scavenging ability, Jubak's Ethyl Acetate fractions was found to be 75.5% at a concentration of 1,000 ㎍/ml, showing the highest antioxidant activity among the extraction solvents. The wrinkle improvement effect was confirmed by measuring the inhibitory activity of elastase and collagenase, and in both test results, Jubak's Ethyl Acetate fractions showed the highest efficacy at a concentration of 1,000 ㎍/ml. As a result of measuring the synthesis rate of pro-collagen type I in CCD-986sk cells induced by UVB, Jubak showed the highest efficacy in the order of Ethyl Acetate, Water, Acetonitrile, and Hexan fractions at the same concentration of 20 ㎍/ml. As a result of measuring the inhibition rate of MMP-1, a collagen degrading enzyme, all four solvent fractions showed an efficacy of more than 70% at 20 ㎍/ml. As a result of measuring the mRNA expression levels of pro-collagen type I, MMP-1, and MMP-3 in a real-time PCR experiment, the protein expression level of pro-collagen type I increased when treated with Jubak fractions compared to the UVB group alone. The mRNA expression levels of MMP-1 and MMP-3 were confirmed to be decreased, and Ethyl Acetate fractions was the most effective in improving wrinkles after the control group (EGCG). As a result, it was confirmed that the Ethyl Acetate fractions among Jubak's solvent fractions has an anti-wrinkle effect against photoaging caused by UVB stimulation, and is expected to be used as a natural material for cosmetics.

• Journal of The Korean Association For Science Education
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• v.29 no.2
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• pp.137-155
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• 2009

The purpose of the present study was to analyse the effectiveness of a gifted education program. To analyse the effectiveness of an education program for the gifted affiliated with a university, the study carried out a quasi-experimental design to compare the 153 gifted students who enrolled in an education center for the gifted and the 131 potentially gifted students who were nominated by teachers for their high achievements and interests in science but without any education services for the gifted. These two groups of students were compared in the aspects of problem finding ability in science, motivation, self regulation, science-related attitudes, and science anxiety through the pre- and post-treatment settings. The results indicated that the gifted group showed a significant improvement in originality and elaboration of problem-finding ability, but the potentially gifted group showed significant decrease in most variables of problem finding. Related to motivation and self-regulated learning, gifted students showed an increase in cognitive strategy use and decrease in intrinsic value, but the potentially gifted students showed significant decreases in most variables related to motivation and self-regulation, except intrinsic value. Related to the scientific attitudes and science anxiety, there were no significant changes between pre- and post-tests in the gifted group, but significant decreases in most variables were found in the potentially gifted group. The results of paired t-test and Ancova indicate that significant differences between the gifted and the potentially gifted groups are mainly due to the significantly lowered performance in post tests in the potentially gifted group, rather than a significant increase in gifted group.

• The Journal of Engineering Geology
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• v.34 no.2
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• pp.279-294
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• 2024

Large-scale civil engineering structures such as dams require a systematic approach to jointed rock-mass grouting to prevent water leakage into the foundations and to ensure safe operation. In South Korea, rock grouting design often relies on the experience of field engineers that was gained in similar projects, highlighting the need for a more systematic and reliable approach. Rock-mass grouting is affected mainly by hydrogeology and the presence of discontinuities, involving factors such as the rock quality designation (RQD), joint spacing (Js), Lugeon value (Lu), and secondary permeability index (SPI). This study, based on data from field investigations of 14 domestic sites, analyzed the correlation between hydrogeological factors (Lu and SPI), discontinuity characteristics (RQD and Js), and grout take, and systematically established a design method for rock grouting. Analysis of correlation between the variables RQD, Js, Lu, and SPI yielded Pearson correlation (r) values as follows: Lu-SPI, 0.92; RQD-Lu, -0.75; RQD-Js, 0.69; RQD-SPI, -0.65; Js-Lu, -0.47; and SPI-Js, -0.41. The grout take increases with Lu and SPI values, but there is no significant correlation between RQD and Js. The proposed approach for grouting design based on SPI values was verified through analysis and comparison with actual curtain-grouting construction, and is expected to be useful in practical applications and future studies.

• Korean Journal of Culture and Social Issue
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• v.12 no.5_spc
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• pp.45-79
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• 2006

The purpose of this paper was to review the results of the subjective well-being(swb) studies performed by Hahn and coworkers in Korean culture. As the correlates of swb, we dealt with demographic/individual difference variables, intrapersonal variables, interpersonal process variables, and Korean cultural variables. We proposed that the components of swb were consisted of quality of life(cognitive swb) and overall happy feelings about one's own life(emotional swb). It was also assumed that a measure of total swb could be calculated by summated mean of cognitive swb and emotional swb measures. The data of the swb studies were analyzed and interpreted according to the above three measures of swb. The results of a nationwide survey(Hahn, 2004) from age of 19 to 75 years ald(n=2,230) showed significant simple correlation coefficients between the following demographic/individual difference variables and swb: Gender difference in swb was found(total swb r=.08, p<.001; life satisfaction r=.10, p<.001; overall emotional swb r=.05, p<.05). Men were happier than women in terms of all three measures of swb. It was also found that women appeared to experience greater positive and negative emotions. Correlation between age and emotional swb(r=.09, p<.001) was significant, but life satisfaction was not significant(r=.04, n.s). Correlations between economic status and swb were also significant(total swb r =.23, p<.001; life satisfaction r=.15 p<.001; overall emotional swb r=.15, p<.001l). Although existence of father was negatively related to emotional swb(r=-.05, p<.05), the existence of mother was not related to any of swb measures. Similarly existence of brothers was related positively to overall emotional swb, but existence of sisters was not. Though existence of son was not related to swb, daughter contributed negatively to swb(total swb -.12, p<.01; life satisfaction -.09, p<.05; emotional swb r=-.12, p<.01). We assumed that family member-in-Iaw also contributed to swb because the extended dose social networks were important in Korean culture. The results showed that the following family member-in-law variables were related to swb: Parents-in-law(total swb r=.11, p<.01; life satisfaction r=.10, p<.01; emotional swb r=.10, p<.01), father-in-law(total swb r=.11, p<.01; life satisfaction r=.11, p<.01; emotional swb r=.06, n.s). The result suggested that especially father-in-law contributed to swb through financial and social support. Correlations between emotional experiences in everyday life and swb were also presented. The range of correlation coefficients between the positive emotion measures and swb were r=.30~.48(p<.001) when the above two measures obtained at same time. But the range decreased to r=.19~32(p<.001) when the swb measure was obtained 9 month later longitudinally. Intercorrelations between positive emotional experience; and life satisfaction were r=.37~58(p<.001) when two measures were obtained at same time. We also examined the effects of the intrapersonal cognitive responses to the most stressful life event upon swb. The results of nationwide survey(n=1,021) showed that self-disclosure(total swb r=.09, p<.010; life satisfaction r=.10, p<.01; emotional swb r=.07, p<.01), rumination(total swb r=-.17, p<.001), thought avoidance(total swb r=.12, p<.001; life satisfaction r=-.08; emotional swb r=-.12, p<.001) and suppression(total swb r=-.13, p<.001; life satisfaction r=-.08, p<.05: emotional swb r=-.13, p<.001) contributed to swb. It was also suggested that mismatch between self-guide and regulatory focus contributed negatively to emotional swb. It was also found that social comparison motives and fulfillment of the motives contributed to swb. The results of a survey research(n=363 college students) revealed that the higher the general social comparison motive, the lower the swb(total swb r=-.15, P<.01: life satisfaction r=-.17. p<.01; emotional swb r=-.10, p<.05). It was also found that satisfaction level of self-evalution motive contributed positively to swb(total swb r=-.14. p<.01: life satisfaction r=-.12, p<.05; emotional swb r=.15, p<.001). Both of self-improvement motive(r=.13, p<.05) and satisfaction level of self-improvement motive(r=.12, p<.05) contributed positively to emotional swb, respectively. The above results suggested that swb was depended upon the interaction effect of social comparison motive; and level of fulfillment of the motives. We also reported the significant multiple predictors of swb in a sample of age from 60years to 89years olds. The results of multiple regression analysis showed that the significant multiple predictors of swb were past illness(β=.174, p<.001), economic status(β=.418, p<.001), marital satisfaction(β=.0841, p<.001), satisfaction of offsprins(β=.065, p<.01), expectation level of social support from offsprings(β=-.049, p<.001), and negative emotions(β=-.454. p<.001) among 16 social psychological factors. It was also found that swb was an important multiple predictors of physical health. This finding was replicated in a longitudinal study. Both of positive and negative emotional experiences were significant multiple predictors of physical health one year later. The results of the discriminant analysis showed both of total swb and positive emotional experiences contributed to discriminate the happy and healthy olds from unhappy and unhealthy olds. We paper also examined the effects of the nonnative social behaviors upon swb in Korean culture. The main hypotheses of the study(Hahn, 2006, in press) was that the important nonnative behaviors would influence on swb through both of the mediation processes of adjustment to social relationships and psychological stress. The survey data were collected from 2,129 adults age of 19 to 75, from 7 regional areas in Korea. The results of the study revealed that almost all of correlation coefficients between 15 normative social behaviors and the above three criteria w-ere significant. The fitness test results of the covariance structural equation model showed that all of the fitness indices were satisfactory (GFI=.974, AGFI=.909, NNFI=.922, NFI=.973, CFI=.974. RMR=.049, RMSEA=.073). The results of the analysis revealed that the following five path coeffi6ents from behaviors to social adjustment were significant; behavior tor family and family members(t=5.87, p<.001), courteous behavior(t=4.39, p<.001), faithful behavior (t=2.15. p<.05). collectivistic behavior(t=8.31, p<.001). Seven path coefficients from the normative behaviors to psychological stress were significant; behavior for family and family members (t=-4.63, p<.001), faithful behavior(t=-3.86, p<.001). suppression of emotional expression(t=3.99, p<.001), trustworthy and dependable behavior(t=-2.21, p<.05), collectivistic behavior(t=3.72, p<.001), effortful and diligent behavior(t=2.94, p<.001), husbandry and saving behavior(t=3.40, p<.001). The above results suggested that four normative behaviors among seven behaviors contributed negatively to psychological stress in current Korean society. The results abo confirmed the hypothesized paths from social adjustment (t=10.40, p<.001) to swb and from psychological stress(t=-19.74, p<.001) to swb. The important results of the study were discussed in terms of the Confucian traditions and recent social changes in Korean culture. Finally limitations of this review paper were discussed and the suggestions for the future study were also proposed.

• Tuberculosis and Respiratory Diseases
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• v.41 no.1
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• pp.1-10
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• 1994

Background: Patients with mitral stenosis(MS) have been demonstrated to have a variable degree of pulmonary dysfunction and exercise impairment. The hemodynamic changes of MS can be reversed after percutaneous mitral balloon valvuloplasty(PMV), but the extent and time course of the imporvement in pulmonary function and exercise capacity are not defined. Methods: In order to investigate the early(3 weeks or less)and late(3 months or more) effects of PMV on pulmonary function and determine if the pulmonary dysfunction is reversible even in patients with moderate to severe pulmonary hypertension, we performed the spirometry, measurements of diffusing capacity and lung volumes, and incremental exercise tests in patients with MS before and after PMV. Results: In 46 patients with MS(age: $40{\pm}12$years, male to female ratio: 1:2, mitral valve area: $0.8{\pm}0.2cm^2$) there was a significant increase in FVC(P<0.0025), $FEV_1$(P<0.001), $FEF_{25-75%}$(P<0.001, $FEF_{50%}$(P<0.001), PEF(P<0.0005), MVV(P<0.005), $\dot{V}O_2$max (P<0.0001), and AT(P<0.0001) after average 10 days of PMV. Also there was a significant decrease in DLco(P<0.0001) and DL/VA(P<0.0001). At later($5{\pm}2$months) follow-up in 11 patients, there was no further improvement in any parameters of pulmonary function and exercise test. Twenty nine patients with sinus rhythm were divided into 16 patients with pulmonary arterial pressure(PAP) more than 35mmHg and/or tricuspid regurgitation grade n or more(group A) and 13 patients with PAP less than 35mmHg(group B). Group A Patients had significantly lower FVC(P<0.001), $FEV_1$(P<0.001), DLco(P<0.05), $\dot{V}O_2$ max(P<0.025) and mitral valve area(P<0.025) than group B patients. Group A patients after PMV, showed significant increase in FVC(P<0.001), maximum $O_2$ pulse(P<0.00001) and $\dot{V}O_2$ max(P<0.00025). Both group showed an increase in AT(P<0.0001, P<0.005), but group A showed greater decrease in $\dot{V}E/\dot{V}O_2$ and $\dot{V}E/\dot{V}CO_2$ both at AT(P<0.001, P<0.001) and $\dot{V}O_2$ max(P<0.0001, P<0.0001) after PMV compared with group B. Conclusion: These data suggest that patients with MS can show increased pulmonary function and exercise performance within 1 month after PMV. Patients with moderate to severe pulmonary hypertension had a significant increase in exercise performance compared with those with mild to no pulmonary hypertension and it is thought to be related to a significat decrease of ventilation for a given oxygen consumption at maximum exercise.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.135-149
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• 2020

Artificial intelligences are changing world. Financial market is also not an exception. Robo-Advisor is actively being developed, making up the weakness of traditional asset allocation methods and replacing the parts that are difficult for the traditional methods. It makes automated investment decisions with artificial intelligence algorithms and is used with various asset allocation models such as mean-variance model, Black-Litterman model and risk parity model. Risk parity model is a typical risk-based asset allocation model which is focused on the volatility of assets. It avoids investment risk structurally. So it has stability in the management of large size fund and it has been widely used in financial field. XGBoost model is a parallel tree-boosting method. It is an optimized gradient boosting model designed to be highly efficient and flexible. It not only makes billions of examples in limited memory environments but is also very fast to learn compared to traditional boosting methods. It is frequently used in various fields of data analysis and has a lot of advantages. So in this study, we propose a new asset allocation model that combines risk parity model and XGBoost machine learning model. This model uses XGBoost to predict the risk of assets and applies the predictive risk to the process of covariance estimation. There are estimated errors between the estimation period and the actual investment period because the optimized asset allocation model estimates the proportion of investments based on historical data. these estimated errors adversely affect the optimized portfolio performance. This study aims to improve the stability and portfolio performance of the model by predicting the volatility of the next investment period and reducing estimated errors of optimized asset allocation model. As a result, it narrows the gap between theory and practice and proposes a more advanced asset allocation model. In this study, we used the Korean stock market price data for a total of 17 years from 2003 to 2019 for the empirical test of the suggested model. The data sets are specifically composed of energy, finance, IT, industrial, material, telecommunication, utility, consumer, health care and staple sectors. We accumulated the value of prediction using moving-window method by 1,000 in-sample and 20 out-of-sample, so we produced a total of 154 rebalancing back-testing results. We analyzed portfolio performance in terms of cumulative rate of return and got a lot of sample data because of long period results. Comparing with traditional risk parity model, this experiment recorded improvements in both cumulative yield and reduction of estimated errors. The total cumulative return is 45.748%, about 5% higher than that of risk parity model and also the estimated errors are reduced in 9 out of 10 industry sectors. The reduction of estimated errors increases stability of the model and makes it easy to apply in practical investment. The results of the experiment showed improvement of portfolio performance by reducing the estimated errors of the optimized asset allocation model. Many financial models and asset allocation models are limited in practical investment because of the most fundamental question of whether the past characteristics of assets will continue into the future in the changing financial market. However, this study not only takes advantage of traditional asset allocation models, but also supplements the limitations of traditional methods and increases stability by predicting the risks of assets with the latest algorithm. There are various studies on parametric estimation methods to reduce the estimated errors in the portfolio optimization. We also suggested a new method to reduce estimated errors in optimized asset allocation model using machine learning. So this study is meaningful in that it proposes an advanced artificial intelligence asset allocation model for the fast-developing financial markets.