• 한국식생활문화학회지
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• 제30권2호
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• pp.197-205
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• 2015

This study was conducted to investigate the bioconversion of ginsenosides as well as anti-inflammatory activities of fresh ginseng Kkakdugi during fermentation. Fresh ginseng Kkakdugi reached proper ripeness, pH 4.30, and acidity 1.69% at $15^{\circ}C$ after 10 days. Lactic acid bacteria grew until reaching $1.10{\times}10^9CFU/mL$ after 20 days of fermentation, and ${\beta}$-glucosidase activity increased from 1.154 to 1.885 units/g. The bioconversion of ginsenosides was confirmed based on increased content of Rg3, an aglycone, from 0.13 to 0.17 mg/g during fermentation through HPLC. Fresh ginseng Kkakdugi did not display cytotoxicity up to the concentrations of $80{\mu}g/mL$, regardless of ripening period. Nitrite production and expression of inflammation-related proteins, iNOS and COX-2, decreased in a dose-dependent manner regardless of ripening period. From these results, fresh ginseng Kkakdugi showed the bioconversion of ginsenosides to aglycone during the lactic acid fermentation as well as an anti-inflammatory effect through the reduction of NO production and iNOS and COX-2 expression.

• 한국전기전자재료학회논문지
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• 제24권12호
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• pp.962-968
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• 2011

In this study, we investigated the effects of Mn dopant (0.1~3.0 at% $Mn_3O_4$ sintered at 1000$^{\circ}C$ for 1 h in air) on the bulk trap (i.e. defect) and grain boundary properties of ZnO, ZM(0.1~3.0) using admittance spectroscopy (AS), and impedance-modulus spectroscopy (IS & MS). As a result, three kinds of defect were found below the conduction band edge of ZnO as 0.09~0.14 eV (attractive coulombic center), 0.22~25 eV ($Zn^{{\cdot}{\cdot}}_i$), and 0.32~0.33 eV ($V^{\cdot}_o$). The oxygen vacancy increased with Mn doping. In ZM, an electrically single grain boundary as double Schottky barrier was formed with 0.82~1.0 eV of activation energies by IS & MS. We also find out that the barriers of grain boundary of Mn-doped ZnO (${\alpha}$-factor=0.13) were more stabilized and homogenized with temperature compared to pure ZnO.

• 한국전기전자재료학회논문지
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• 제26권12호
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• pp.909-914
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• 2013

CIGS is one of thin film solar cell and has been studied so much, because of the possibility of low price and high efficiency. Until now, co-evaporation and sputtering were typical method to prepare CIGS absorption layer, and a few company commercialized solar cell by these method. However, non-vacuum process which has been studied for long time has not been progressed, though the merit of low price. Especially, aerosol deposition method has not been reported, because it is difficult to prepare a large quantity of various CIGS powder. In this study, CIGS powder was synthesized by mechanochemical method and CIGS absorption layer was deposited by aerosol deposition method. The thickness of the CIGS layer was controlled by the number of deposition and the surface roughness of it was affected by the amount of flow gas. And, also, I-V curve of it appeared metallic property in the case of 'as deposition'. After heat treatment in Se-rich atmosphere, the electrical property of it changed to a semiconductor. CdS and transparent conduction layer were formed by a typical method on it for solar cell. The efficiency of cell was appeared 0.19%. Though the efficiency was low because of the disharmony in the after-process, it was conformed that CIGS solar cell could be prepared by aerosol deposition.

• Interaction and multiscale mechanics
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• 제1권2호
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• pp.211-230
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• 2008

Owing to the growing size of the eigenvalue problem and the growing number of eigenvalues desired, solution methods of iterative nature are becoming more popular than ever, which however suffer from low efficiency and lack of proper convergence criteria. In this paper, three efficient iterative eigenvalue algorithms are considered, i.e., subspace iteration method, iterative Ritz vector method and iterative Lanczos method based on the cell sparse fast solver and loop-unrolling. They are examined under the mode error criterion, i.e., the ratio of the out-of-balance nodal forces and the maximum elastic nodal point forces. Averagely speaking, the iterative Ritz vector method is the most efficient one among the three. Based on the mode error convergence criteria, the eigenvalue solvers are shown to be more stable than those based on eigenvalues only. Compared with ANSYS's subspace iteration and block Lanczos approaches, the subspace iteration presented here appears to be more efficient, while the Lanczos approach has roughly equal efficiency. The methods proposed are robust and efficient. Large size tests show that the improvement in terms of CPU time and storage is tremendous. Also reported is an aggressive shifting technique for the subspace iteration method, based on the mode error convergence criteria. A backward technique is introduced when the shift is not located in the right region. The efficiency of such a technique was demonstrated in the numerical tests.

• BMB Reports
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• 제42권10호
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• pp.685-690
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• 2009

Angiogenesis is essential for tumor growth and vascular endothelial cell growth factor (VEGF) plays a key role in this process. Conversely, sphingosine 1-phosphate (S1P) is a biologically active sphingolipid known to play a key role in cancer progression by regulating endothelial cell proliferation and migration. In this study, the authors found that S1P increases the level of VEGF mRNA in human umbilical vein endothelial cells (HUVECs) and immortalized HUVECs (iHUVECs). Additionally, S1P was found to increase VEGF promoter activity in MS-1 mouse pancreatic islet endothelial cells. Furthermore, a pharmacological inhibitory study revealed that $G_{\alpha i/o}$-mediated phospholipase C, Akt, Erk, and p38 MAPK signaling are involved in this S1P-induced expression of VEGF. A component of AP1 transcription factor is important for S1P-induced VEGF expression. Taken together, these findings suggest that S1P enhances endothelial cell proliferation and migrat ion by upregulating the expression of VEGF mRNA.

• 한국항공우주학회지
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• 제36권1호
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• pp.22-30
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• 2008

본 논문은 헬리콥터 기동비행문제를 비선형 최적제어기법으로 정식화 하고 이를 indirect method를 적용하여 해석하는 기법에 대해 연구하였다. 주어진 기동비행 경로에 대한 오차를 벌칙함수 형태의 가격(비용, 목적)함수로 채택하고 이를 최소화하도록 정식화하면 기동비행은 구속조건이 없는 최적제어문제로 정식화 된다. 정식화 결과로 얻어지는 이점 경계값 문제는 Multiple Shooting Method (MSM)을 적용하여 해석하였다. 본 논문은 shooting node의 수와 상태변수의 초기화 방법 등이 수치해법에 주는 영향을 분석하여 수렴성 확보에 필요한 조건을 식별하고 수렴반경을 증가시킬 수 있는 방안에 초점을 두었다. 연구결과는 헬리콥터와 같이 불안정한 시스템의 최적제어 문제에 indirect method를 적용하는 경우 수치해법의 안정성과 수렴성을 확보할 수 있는 방법을 제시한다.

• 공학교육연구
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• 제22권6호
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• pp.28-39
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• 2019

In order to improve this, Korean universities should reorganize their curriculum such as job system research and job - based program development according to the demand of industry in order to improve their working ability due to the decrease of the school - age population and the youth unemployment rate. In this study, first, conceptualization of friendly education and definition of industry - university cooperation and analysis of cases related to friendly - educational cooperation between industry and academia, second, analysis of fusion healing majors in Healing Bio - I want to conduct research. Konkuk University Healing Bioresource College conducted a survey based on demand such as experts and industry for the development of industry - academic cooperation - friendly curriculum. As a result of this process, I developed a curriculum development committee to study the internal and external environment through the literature survey, focus group interviews, and Delphi research. The purpose of this study is to develop competitiveness curriculum reflecting competitiveness of human resource development in Korea, to develop competitiveness curriculum that reflects customized opinions of societal demand, to organize systematic curriculum to have practical ability, to strengthen the employment link through development of curriculum in accordance with the direction of human resources development, We will make contribution to build the system of operation from the center to the consumer center, evaluation of the practical ability through the curriculum and the feedback system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권11호
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• pp.3967-3983
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• 2014

The performance of an partial relay selection on the decode-and-forward (DF) mode cognitive radio (CR) relay networks is studied, with some important factors, including the outage probability, the bit error ratio (BER), and the average channel capacity being analyzed. Different from the conventional relay selection schemes, the impact of spectrum sensing process as well as the spectrum utilization efficiency of primary users on the performance of DF-based CR relaying networks has been taken into consideration. In particular, the exact closed-form expressions for the figures of merit such as outage probability, BER, and average channel capacity over independent and identically distributed (i.i.d.) Rayleigh fading channels, have been derived in this paper. The validity of the proposed analysis is proven by simulation, which showed that the numerical results are consistent with the theoretical analysis in terms of the outage probability, the BER and the average channel capacity. It is also shown that the full spatial diversity order can always be obtained at the signal-to-noise ratio (SNR) range of [0dB, 15dB] in the presence of multiple potential relays.

• 디지털융복합연구
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• 제14권4호
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• pp.379-385
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• 2016

최근 IT 기업들에서 미래 산업으로 자동차에 관한 관심이 지속적으로 증가 하고 있다. 구글, 애플, 삼성과 같은 IT전문 기업들이 자동차 산업에 뛰어 들어 커넥티드카 분야에 많은 연구를 집중 하고 있다. 이러한 시점에서 커넥티드카의 개념에 대해 알아 보고 현재 커넥티드카의 여러 방법 중 하나인 미리링크에 관해 알아 본다. 또한 이러한 커넥티드카의 과도기적인 시점에서 아이폰을 이용한 미러링크의 한 방법을 제안하고 이것을 이용한 커넥티드카의 활용방법에 대해 알아보는 것을 본 연구의 목적으로 한다. 이러한 제안은 현재 자동차를 구매한 많은 사람들이 추가 비용을 들이지 않고 앞으로 출시될 커넥티드카의 기능을 포함 하고 있는 자동차를 미리 경험 할 수 있는 기회가 될 것이며 사용하고 있는 스마트 폰을 통해 자동차를 커넥티드카로 만들 수 있는 경험을 하게 될 것이다.

• 대한안전경영과학회지
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• 제18권3호
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• pp.63-70
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• 2016

The main point of this study is to find out duplicates and differences among various regulations from different organizations. Also, it focuses on creating a reasonably unified regulation system to standardize safety & environment management. In this study, I analyzed the commonalities and the differences of two systems which are typical korean Process Safety Management System and off-site Consequence Analysis. It is confirmed that there are 25 species of overlapped material of those two systems and assessment like handling material information, facilities lists, hazardous substances and list of machine power. Process safety report focuses on onsite workers and facility protect. On the other hand, off-site Consequence Analysis focuses on design, arrangement and management of handling facility from off-site influence. I found difference two system of Enforcement purposes and way. Contradiction of Harmful information of Chemicals Control Act and occupation safety and health acts from same material. To be specific, There are no unit rule of occupation safety and health acts. so it permit inch, psi etc. But Chemicals Control Act provides that m, Mpa units. Therefore, Each regulatory duplication of items for chemicals management, standardization is writing so that you can coordinate overlapping items in the measures the need to be presented.