• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.541-546
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• 2021

Hydrated liquid crystalline vesicles containing a high content of ceramide were prepared by constituting an optimal composition in which ceramides can be mutually self-associated with phospholipid and cholesterol. From the result of manufacturing various vesicles with different component composition, when the edge activator sodium deoxycholate (SDOC) and the solubilizer PEG-60 hydrogenated castor oil (HCO 60) were mixed to form vesicles, the smallest nano-sized particles were produced and the vesicle dispersion solution was weakly acidic and maintained the most stable state. In addition, it was confirmed through polarized light microscopy and thermal analysis that the addition of SDOC and HCO 60 had an effect on the inhibition of crystallinity of lipid components such as ceramide. The stability of the vesicle dispersion solution was maintained without change in appearance and viscosity even after long-term storage at high temperature for eight weeks.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.105-116
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• 2019

Oil adsorption during hair or body washing is responsible for the hair conditioning. In this study, we established a method to extract oil from a substrate, and to determine amount of adsorbed oil upon substrate using a conventional absorption spectroscopy. We controlled the mole fraction of a surfactant in a mixture of anionic and amphoteric surfactants because that it induces the coacervate that regulates amount of adsorbed oil through the alteration of oil viscosity. Based on this, we established the optimized condition for adsorption and extraction for oil. UV absorbance were employed to estimate the amount of adsorbed oil using optical absorbance after extraction via adsorption. The estimation was confirmed by comparing with a mass analysis in HPLC and an adhesive energy in AFM. It has been proved that this method can be applied to all cases of oil adsorption from the results with various cationic polymers and a complex system of the polymers which regulate the oil adsorption.

• The Korean Journal of Applied Statistics
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• v.34 no.4
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• pp.589-597
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• 2021

In simple and multiple regression, there is a difference in the meaning of regression coefficients, and not only are the estimates of regression coefficients different, but they also have different signs. Understanding the relative contribution of explanatory variables in a regression model is an important part of regression analysis. In a standardized regression model, the regression coefficient can be interpreted as the change in the response variable with respect to the standard deviation when the explanatory variable increases by the standard deviation in a situation where the values of the explanatory variables other than the corresponding explanatory variable are fixed. However, the size of the standardized regression coefficient is not a proper measure of the relative importance of each explanatory variable. In this paper, the estimator of the regression coefficient in multiple regression is expressed as a function of the correlation coefficient and the coefficient of determination. Furthermore, it is considered in terms of the effect of an additional explanatory variable and additional increase in the coefficient of determination. We also explore the relationship between estimates of regression coefficients and correlation coefficients in various plots. These results are specifically applied when there are two explanatory variables.

• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.277-282
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• 2021

Two hydrophobic imidazolium based ionic liquids including 1-benzyl-3-butylimidazolium hexafluorophosphate [BzBIM]PF₆ and 1-pentyl-3-butylimidazolium hexafluorophosphate [PBIM]PF₆ having the same anion and different cation parts were synthesized. The structural composition of these ionic liquids were confirmed with Fourier-transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (¹H-NMR). Their physiochemical properties such as viscosity, ionic conductivity and thermal stability alongside electrochemical potential window range for both ionic liquid electrolytes were characterized and compared to each other. The overall results revealed that [BzBIM]PF₆ has higher thermal and electrochemical stabilities and viscosity than that of [PBIM]PF₆ probably due to the presence of benzyl ring in the imidazolium cation providing strong intermolecular π-π interactions.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.343-350
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• 2022

In this article, we report a case study on the cause of abnormal fermentation of Takju based on a microbial community analysis of wheat-based Nuruk and Takju using next-generation sequencing. The microbial community showed notable changes during alcoholic fermentation. Members of the genera Aspergillus and Staphylococcus were dominant in Nuruk, whereas Saccharomyces, Pediococcus, Bacillus, Lactobacillus, and Enterobacter were predominant during Takju fermentation. In particular, members of the Enterobacter and Bacillus genera that were present were identified as the opportunistic pathogens B. wiedmannii and E. cloacae. The relative abundance of two species increased in Mitsul-3, wherein the concentration of organic acid rapidly decreased, and in Deotsul-1, in which raw materials were added. Furthermore, the relative abundance of lactic acid bacteria (LAB) in both the Nuruk and Takju was very low. Therefore, this result showed that the abnormal proliferation of E. cloacae and B. wiedmannii in Takju was due to the absence of LAB.

• Composites Research
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• v.35 no.4
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• pp.288-297
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• 2022

This study investigated the effect of addition of zirconia(zirconium oxide) powder on the curing behavior of phenolic resins. The heating rate controlled curing and isothermal curing behaviors of the phenol resin according to the content of the zirconia powder were analyzed. The viscosity and thermal decomposition characteristics of the phenolic resin with the zirconia content were also examind. From the DSC analysis, the degree of cure and the rate of cure were obtained. Finally, the activation energy for the cure reaction were calculated from the DSC data of the zirconia added phenolic resin. As a found, the higher the zirconia content, the longer the curing was delayed and the greater the activation energy required for curing. Additionally, the TGA result that as the content of zirconia increased, less weight loss was observed. The surface tackiness of the Carbon/Phenol prepreg was partially changed according to the zirconia content, but had no significant effect.

• Korean Journal of Comparative Education
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• v.24 no.1
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• pp.1-29
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• 2014

The purpose of this case study is to examine and compare the basic characteristics of quality assurance systems of the 3 leading countries in international higher education: Australia, Canada, and the Netherlands. The comparative analysis of the three cases demonstrates that, taking a more commercial stance on the international education service market, quality assurance systems of the 3 countries aim at facilitating effective promotion of student recruitment and enhancing their national brand image as advanced knowledge society. Consequently, rules and regulations of their systems are concerned primarily with strengthening institutional capacities to educate international students effectively, and, ultimately, improving their learning experiences in the host countries. Compared to these foreign cases, the newly-adopted quality assurance system in Korea places too much emphasis on internationalization process itself, thereby neglecting evaluation of educational capabilities of higher education institutions. Further implications for improvement of the Korean International Education Quality Assurance System(IEQAS) are discussed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.1
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• pp.103-114
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• 2023

This study collected various data of urban roadways to analyze the effect of travel speed change, and a GRU-based short-term travel speed prediction model was developed using such big data. The baseline model and the double exponential smoothing model were selected as comparison models, and prediction errors were evaluated using the RMSE index. The model evaluation results revealed that the average RMSE of the baseline model and the double exponential smoothing model were 7.46 and 5.94, respectively. The average RMSE predicted by the GRU model was 5.08. Although there are deviations for each of the 15 links, most cases showed minimal errors in the GRU model, and the additional scatter plot analysis presented the same result. These results indicate that the prediction error can be reduced, and the model application speed can be improved when applying the GRU-based model in the process of generating travel speed information on urban roadways.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.10
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• pp.461-469
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• 2018

The main purpose of this study is to examines peculiar competitive advantages of Korean women businessmen(Han-Sang) in Australia. The results of case analysis are summarized as follows. First competitive advantage is CEO's excellent dynamic capabilities like wonderful adaptability, woman's unique delicate management style, mom's unique emotional leadership and showing leadership by example. Second competitive advantage is Korean peculiar sincerity and diligence, can-do spirit, perseverance and fast implementation. Lastly, The social status as Korean immigrants made them weak position in Australian society but it was found that they have made weakness a strength. They built up the solidarity with Korean immigrant society and took advantage of it for their business. Based on the results, implications for researchers and practitioners are discussed.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.11-11
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• 2020

18년 물관리일원화 이후 인프라와 사람 중심으로부터 자연과 인간의 조화를 위한 환경·생태계의 자연성 회복으로의 물관리 패러다임 전환이 빠르게 이루어지고 있으며, 대규모 국책사업이후의 하천 관리에 있어서도 기존의 이수, 치수, 환경이라는 단순한 기능적 구분을 벗어나 보다 근본적이고 장기적인 대국민 서비스로의 전환을 도모하고 있다. 또한, ICBAM 등으로 정의되는 4차산업혁명 기반 기술의 접목이 거의 대부분의 분야에서 이루어지고 있는 것을 실질적으로 체감하는 시기가 도래하였다. 그러나, 하천 및 수자원 관리분야에서의 기술은 근대 엔지니어링의 기초가 되는 수로 건설 등으로부터 시발되어 사실상 가장 앞선 과학적 진보의 토대를 갖추었으나 최근의 기술적 트렌드를 잘 추종하지 못하는 것처럼 비추어 지는 것이 사실이다. 주된 이유로서 기후변화라는 광범위하고 장기적인 입력요소를 가진 하천관리 시스템의 특성상 불확실성의 추정 및 즉각적인 응답이 어려운 부분이 분명히 존재하지만, 실질적으로 여전히 해소되지 않는 부분은 하천의 기초자료 수집에 대한 효율성과 신뢰도가 낮은 것이라고 하겠다. 또한, 유역으로부터 댐-다기능보-하천으로 이어지는 의사결정을 위한 다양한 형태의 자료로부터 적절한 정보를 수집하는 체계(거버넌스의 문제이자 기술적/재정적 한계)가 확립되지 않은 점도 고려해야 할 것이다. 본 연구에서는 인공지능을 활용한 하천의 유량 예측 등을 위해 필요한 수자원 기초데이터의 근원적인 수집 및 관리상의 문제점에 대해서 검토하고자 하였으며, ARIMA, Kalman Filtering, MA 및 복합기법을 통한 자료처리 기법을 적용하여 상황에 맞게 오차 및 불확실성의 저감을 위한 방안을 찾고자 하였다. 또한, 이용자 중심의 하천 관리에 근접한다고 볼 수 있는 스마트워터시티 개념에서의 바람직한 하천관리 기법에 대해서 논의하고, 관련하여 근자에 개발한 하천의 물리적 해석 도구들에 대해서 적용 사례를 검토한다. 마지막으로, 지식기반의 하천관리 의사결정 플랫폼 개발을 위해서 기존의 기계학습을 통한 자동화된 의사결정에 부가하여 전문가와 시스템이 상호작용을 통해서 AI를 학습시켜 결정한 사항을 전문가의 의사결정에 참고하는 MCRDR기법의 적용의 적용 가능성과 도입 방향에 대해서 논의하였다.