• Title/Summary/Keyword: 2 order system

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China's Economic Slow-down and the Middle-Income Trap Controversy (중국의 저성장과 '중진국함정론'에 근거한 위기요인 분석)

  • Kim, Eui-Dong
    • International Area Studies Review
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    • v.20 no.2
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    • pp.113-140
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    • 2016
  • This paper first extracts the main basis for the Middle-Income Trap(MIT) to apply these grounds to reality of the Chinese economy. And then confirmed crisis factors of China economy. Also discussed then the economic reforms of China in order to not fall into the MIT. After reviewing previous research extracted six factors the results will correspond to comply with the Chinese economy. Those are 'Over-investment', 'excess capacity' 'reduction of TFP continued,' 'disappearance and the aging of the population bonus', 'excessive debt and structural adjustment and financial instability of the company', 'income unequal expansion', 'low financial and information infrastructure accessibility', and 'low transparency index'. China's policy direction to avoid the MIT generally set properly, but proof that implementation process not easy, was appearing everywhere. After all, China economy should be modified now to a reforms of 'government failure' and promotion of function for ongoing restructuring system in the market. Because of the SDR incorporation from 2015, it is inevitable to face major constraints in the external aspects.

Validation on the Analytical Method of Ginsenosides in Red Ginseng

  • Cho B. G.;Nho K. B.;Shon H. J.;Choi K. J.;Lee S. K.;Kim S. C;Ko S. R.;Xie P. S.;Yan Y. Z.;Yang J. W.
    • Proceedings of the Ginseng society Conference
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    • 2002.10a
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    • pp.491-501
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    • 2002
  • A cross-examination between KT&G Central Research Institute and Guangzhou Institute for Drug Control was carried out in order to select optimum conditions for extraction, separation and determination of ginsenosides in red ginseng and to propose a better method for the quantitative analysis of ginsenosides. The optimum extraction conditions of ginsenosides from red ginseng were as follows: the extraction solvent, $70\%$ methanol; the extraction temperature, $100^{\circ}C;$ the extraction time, 1 hour for once; and the repetition of extraction, twice. The optimum separation conditions of ginsenosides on the SepPak $C_{18}$ cartridge were as follows: the loaded amount, 0.4 g of methanol extract; the washing solvents, distilled water of 25 ml at first and then $30\%$ methanol of 25 ml; the elution solvent, $90\%$ methanol of 5 ml. The optimum HPLC conditions for the determination of ginsenosides were as follows: column, Lichrosorb $NH_2(25{\times}0.4cm,$ 5${\mu}m$, Merck Co.); mobile phase, a mixture of acetonitrile/water/isopropanol (80/5/15) and acetonitrile/water/isopropanol (80/20/15) with gradient system; and the detector, ELSD. On the basis of the optimum conditions a method for the quantitative analysis of ginsenosides were proposed and another cross-examination was carried out for the validation of the selected analytical method conditions. The coefficient of variances (CVs) on the contents of ginsenoside-$Rg_{1}$, -Re and $-Rb_1$ were lower than $3\%$ and the recovery rates of ginsenosides were $89.4\~95.7\%,$ which suggests that the above extraction and separation conditions may be reproducible and reasonable. For the selected HPLC/ELSD conditions, the CVs on the detector responses of ginsenoside-Rg, -Re and $-Rb_1$) were also lower than $3\%$, the regression coefficients for the calibration curves of ginsenosides were higher than 0.99 and two adjacent ginsenoside peaks were well separated, which suggests that the above HPLC/ELSD conditions may be good enough for the determination of ginsenosides.

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Vibration Analysis of Large Structures by the Component-Mode Synthesis (부분구조진동형 합성방법에 의한 대형구조계의 진동해석)

  • B.H. Kim;T.Y. Chung;K.C. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.30 no.3
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    • pp.116-126
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    • 1993
  • The finite element method(FEM) has been commonly used for structural dynamic analysis. However, the direct global application of FEM to large complex structures such as ships and offshore structures requires considerable computational efforts, and remarkably more in structural dynamic optimization problems. Adoption of the component-mode synthesis method is an efficient means to overcome the above difficulty. Among three classes of the component-mode synthesis method, the free-interface mode method is recognized to have the advantages of better computational efficiency and easier implementation of substructures' experimental results, but the disadvantage of lower accuracy in analytical results. In this paper, an advanced method to improve the accuracy in the application of the free-interface mode method for the vibration analysis of large complex structures is presented. In order to compensate the truncation effect of the higher modes of substructures in the synthesis process, both residual inertia and stiffness effects are taken into account and a frequency shifting technique is introduced in the formulation of the residual compliance of substructures. The introduction of the frequency shrift ins not only excludes cumbersome manipulation of singular matrices for semi-definite substructural systems but gives more accurate results around the specified shifting frequency. Numerical examples of typical structural models including a ship-like two dimensional finite element model show that the analysis results based on the presented method are well competitive in accuracy with those obtained by the direst global FEM analysis for the frequencies which are lower than the highest one employed in the synthesis with remarkably higher computational efficiency and that the presented method is more efficient and accurate than the fixed-interface mode method.

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Applicability Estimation of Ballast Non-exchange-type Quick-hardening Track Using a Layer Separation Pouring Method (층 분리주입을 이용한 도상자갈 무교환방식 급속경화궤도의 적용성 평가)

  • Lee, Il Wha;Jung, Young Ho;Lee, Min Soo
    • Journal of the Korean Society for Railway
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    • v.18 no.6
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    • pp.543-551
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    • 2015
  • Quick-hardening track (QHT) is a construction method which is used to change from old ballast track to concrete track. Sufficient time for construction is important, as the construction should be done during operational breaks at night. Most of the time is spent on exchanging the ballast layer. If it is possible to apply the ballast non-exchange type of quick-hardening track, it would be more effective to reduce the construction time and costs. In this paper, pouring materials with high permeability are suggested and a construction method involving a layer separation pouring process considering the void condition is introduced in order to develop ballast non-exchange type of QHT. The separate pouring method can secure the required strength because optimized materials are poured into the upper layer and the lower layer for each void ratio condition. To ensure this process, a rheology analysis was conducted on the design of the pouring materials according to aggregate size, the aggregate distribution, the void ratio, the void size, the tortuosity and the permeability. A polymer series was used as the pouring material of the lower layer to secure the void filling capacity and for adhesion to the fine-grained layer. In addition, magnesium-phosphate ceramic (MPC) was used as the pouring material of the upper layer to secure the void-filling capacity and for adhesion of the coarse-grained layer. As a result of a mechanics test of the materials, satisfactory performance corresponding to existing quick-hardening track was noted.

Anti-Oxidative and Inhibitory Effect of Saussurea involucrata on MMP-1 in UVA-irradiated Human Dermal Fibroblast (설련의 항산화능와 사람 섬유아세포에서 UVA에 의한 MMP-1발현 저해효과)

  • Sim, Gwan-Sub;Kim, Jin-Hwa;Na, Young;Lee, Dong-Hwan;Lee, Bum-Chun;Zhang, Yong-He;Pyo, Hyeong-Bae
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.4 s.54
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    • pp.329-335
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    • 2005
  • In order to investigate the effects of Saussurea involucrata on (relationship between) aging (and Saussurea involucrata), we examined the activities of antioxidation, in vitro MMP inhibition and UVA-induced MMP-1 expression in human dermal fibroblasts. S. involucrata showed scavenging activities radicals and reactive oxygen species (ROS) with the $IC_{50}$ values of $3.89{\mu}g/mL$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and $67.29{\mu}g/mL$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. At the concentration of $1000{\mu}g/mL$, S. involucrata showed 93.27% inhibition on lipid peroxidation of linoleic acid. S. involucrata inhibited the activities of MMP-1 in a does-dependent manner and the $IC_{50}$ value calculated from semi-log plots was $97.18{\mu}g/mL$. Also, UVA induced MMP expression in human dermal fibroblasts was reduced 42.86% by treatment with S. involucrata, and MMP-1 mRNA expression was reduced in a dose-dependent manner. Therefore S. involucrata was able to significantly inhibit MMP expression in protein and mRNA level. All these results suggested that S. involucrata might act as an anti-aging agent by antioxidation and reducing UVA-induced MMP-1 production.

Development of Computer Code for Simulation of Multicomponent Aerosol Dynamics -Uncertainty and Sensitivity Analysis- (다성분 에어로졸계의 동특성 묘사를 위한 전산 코드의 개발 -불확실성 및 민감도 해석-)

  • Na, Jang-Hwan;Lee, Byong-Whi
    • Nuclear Engineering and Technology
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    • v.19 no.2
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    • pp.85-98
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    • 1987
  • To analyze the aerosol dynamics in severe accidents of LMFBR, a new computer code entitled MCAD (Multicomponent Aerosol Dynamics) has been developed. The code can treat two component aerosol system using relative collision probability of each particles as sequences of accident scenarios. Coagulation and removal mechanisms incorporating Brownian diffusion and gravitational sedimentation are included in this model. In order to see the effect of particle geometry, the code makes use of the concept of density correction factor and shape factors. The code is verified using the experimental result of NSPP-300 series and compared to other code. At present, it fits the result of experiment well and agrees to the existing code. The input variables included are very uncertain. Hence, it requires uncertainty and sensitivity analysis as a supplement to code development. In this analysis, 14 variables are selected to analyze. The input variables are compounded by experimental design method and Latin hypercube sampling. Their results are applied to Response surface method to see the degree of regression. The stepwise regression method gives an insight to which variables are significant as time elapse and their reasonable ranges. Using Monte Carlo Method to the regression model of LHS, the confidence level of the results of MCAD and their variables is improved.

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Antioxidative activity of roasted Pueraria lobata root extracts (로스팅 칡 추출물의 항산화 활성)

  • Choi, Goo-Hee;Kim, Hyun Jung;Park, In-Jae;Kim, Bong-Gyun;Kim, Hoi-Yeong;Jeong, Jae-Hyun;Cho, Ju-Hyun
    • Food Science and Preservation
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    • v.24 no.3
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    • pp.440-445
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    • 2017
  • We evaluated the antioxidative activity of extracts of P. lobata root depending on roasting conditions. P. lobata roots were roasted at three different temperature at $150^{\circ}C$, $200^{\circ}C$, and $250^{\circ}C$ and three different time at 10 min, 20 min, and 30 min respectively. Roasted P. lobata root was extracted using water at $85^{\circ}C$ for 6 h and filtered using filter paper, followed by then evaporated ($12{\pm}0.3^{\circ}Brix$) and freeze-dried. The concentration of maker compound puerarin was determined using a high performance liquid chromatography system. 2 phenolic compounds, flavonoid contents, and antioxidant activities of the extract powder were evaluated. Puerarin contents, Phenolic compounds, and flavonoid contents of roasted P. lobata root were higher than those of unroasted P. lobata root. The results of DPPH and ABTS showed that roasted P. lobata root possessed higher antioxidant activity than unroasted P. lobata root. This study suggested that roasting process could be applied to P. lobata root in order to achieve its high quality and functionality.

Health Risk Assessment with Source Apportionment of Ambient Volatile Organic Compounds in Seoul by Positive Matrix Factorization (수용체 모델(PMF)를 이용한 서울시 대기 중 VOCs의 배출원에 따른 위해성평가)

  • Kwon, Seung-Mi;Choi, Yu-Ri;Park, Myoung-Kyu;Lee, Ho-Joon;Kim, Gwang-Rae;Yoo, Seung-Sung;Cho, Seog-Ju;Shin, Jin-Ho;Shin, Yong-Seung;Lee, Cheolmin
    • Journal of Environmental Health Sciences
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    • v.47 no.5
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    • pp.384-397
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    • 2021
  • Background: With volatile organic compounds (VOCs) containing aromatic and halogenated hydrocarbons such as benzene, toluene, and xylene that can adversely affect the respiratory and cardiovascular systems when a certain concentration is reached, it is important to accurately evaluate the source and the corresponding health risk effects. Objectives: The purpose of this study is to provide scientific evidence for the city of Seoul's VOC reduction measures by confirming the risk of each VOC emission source. Methods: In 2020, 56 VOCs were measured and analyzed at one-hour intervals using an online flame ionization detector system (GC-FID) at two measuring stations in Seoul (Gangseo: GS, Bukhansan: BHS). The dominant emission source was identified using the Positive Matrix Factorization (PMF) model, and health risk assessment was performed on the main components of VOCs related to the emission source. Results: Gasoline vapor and vehicle combustion gas are the main sources of emissions in GS, a residential area in the city center, and the main sources are solvent usage and aged VOCs in BHS, a greenbelt area. The risk index ranged from 0.01 to 0.02, which is lower than the standard of 1 for both GS and BHS, and was an acceptable level of 5.71×10-7 to 2.58×10-6 for carcinogenic risk. Conclusions: In order to reduce the level of carcinogenic risk to an acceptable safe level, it is necessary to improve and reduce the emission sources of vehicle combustion and solvent usage, and eco-car policies are judged to contribute to the reduction of combustion gas as well as providing a response to climate change.

Study on the Evaluation Method of Autonomous Vehicle Driving Ability Based on Virtual Reality (가상환경 기반 자율주행 운전능력 평가방안 연구)

  • Kim, Joong Hyo;Kim, Do Hoon;Joo, Sung Kab;Oh, Seok Jin
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.5
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    • pp.202-217
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    • 2021
  • Following the fatal accident of pedestrians caused by Autonomous Vehicle by Uber, the world's largest ride-hailing company, two people were killed in a self-driving car accident by Tesla in April. There is a need to ensure the safety of road users. Accordingly, in order to secure the safety of Autonomous Vehicle driving, it is necessary to evaluate Autonomous Vehicle driving technologies in various situations based on the road and traffic environment in which the Autonomous vehicle will actually drive. Therefore, this study used UC-win/Road ver.14.0 based on general driver's license test questions to present a virtual reality-based Autonomous Vehicles driving ability evaluation tool among various driving ability test method. Based on this, it was intended to test driving ability for unexpected situations in complex and diverse driving environments, and to confirm its practical applicability as an optimal tool for Autonomous vehicle ability test and evaluation.

Development Strategy of Korean Economy Through Economic Cooperation with Central Asian Countries (한국의 지속적인 경제성장을 위한 중앙아시아 진출 확대 전략)

  • Chung, Haing Deuck;Lee, Sang Ho
    • International Area Studies Review
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    • v.13 no.2
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    • pp.311-368
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    • 2009
  • In order to survive the on-going natural resource war, Korea needs various efforts such as enhancing self-exploitation ratio, increasing the supply of new-reuse energy, strengthening cooperation with resource rich countries. Central Asian countries are geometrically far away from Korea. However, Korea should try to develop political, economic and ethnic relationship with those countries into much higher dimension to secure various natural resources. Major countries including U.S., EU. Japan and China are approaching Central Asian countries with long term perspective. Improving country-image through enlargement of ODA is the first concern of those countries. Korea should try to follow their practices. Government should try to improve Korea's image in the first place and lead economic cooperation with very detailed supportive measures to induce Korean firms' investment into the Central Asian countries. In the due process, a lot of information about those countries' political climate, social situation, ethnical composition, major religions, educational system, current state and structure of economies and industries, etc should be made available to Korean firms.