• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.46-51
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• 2012

This study aims to develop the performance analysis program on the staged combustion cycle of the liquid rocket engine using liquid oxygen(LOx) as oxidizer, liquid hydrogen(LH2) and RP-1 as fuel. The developed analysis program can obtain the propellant mass flow rate, the specific impulse, and representative design values of engine components for the required thrust satisfying pressure, mass flow, and energy balance conditions. The analysis results show that the the specific impulses (Isp) compared to those of the real engines have been less than 1%. With additional constraints, the program will be improved for the system optimization.

• Informatization Policy
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• v.25 no.1
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• pp.3-29
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• 2018

The Federal Communications Commission voted to repeal net neutrality protections on December 14, 2017. This is the very opposite decision of the net neutrality rule that the Obama administration has consistently maintained. The ensuing storm from the repeal of net neutrality protections has an extensively effect enough on individuals and businesses to cover the entire spectrum, and the impact is hard to assess in the U. S. content industry, which dominates the worldwide Internet content and platform market. On the other hand, Korea's net neutrality protections have been firmly pursued, and there is no sign of change even after the decision happened in the U. S. Net neutrality is not a simple theme that is associated with the Constitution, such as freedom of expression, as well as the issue of network enhancement to prepare for 5G. Accordingly, this study examines how the net neutrality has been carried out in the U. S. and Korea over the years, and provides the issues of Internet enhancement, perspectives of ISP and ICP, and implications for the Constitution, market economy, fair competition and zero rating. This research delivers future direction and implications of domestic net neutrality policies.

• The Korean Society of Law and Medicine
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• v.18 no.1
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• pp.103-141
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• 2017

The (Korean) Medical Services Act revised in 2009 introduces the accreditation of specialty hospital. When a hospital meets prescribed standards, passes a board review, and is accredited as a specialty hospital by the Minister of Health and Welfare, then it may use 'specialty hospital' in its name and certification mark of specialty hospital. The problem is that the (Korean) Fair Trade Commission and the (Korean) Ministry of Health and Welfare, both of which have authorities to regulate advertising in general and in health care service in turn, announced the guidelines to prohibit internet (portal) service providers to provide keyword search ads service using key-words such as 'specialty' or 'specialized in' for those who are not accredited by the Minister of Health and Welfare. In this article, whether these guidelines can be justified by the current regime and whether the current specialty hospital policy is agreeable would be examined. To do this, the legal nature of accreditation of specialty hospital, the limit of advertisement regulation, the law of keyword search ads, and the liability of internet service providers also would be analyzed.

• Journal of Life Science
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• v.18 no.12
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• pp.1764-1770
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• 2008

The goal of this study is to increase production of astaxanthin in recombinant Escherichia coli by engineered isoprenoid pathway. We have previously reported structural and functional analysis of the astaxanthin biosynthesis genes from a marine bacterium, Paracoccus haeundaensis. The carotenoid biosynthesis gene cluster involved in astaxanthin production contained six carotenogenic genes (crtW, crtZ, crtY, crtI, crtB, and crtE genes) and recombinant E. coli harboring six carotenogenic genes from P. haeundaensis produced 400 ${\mu}g$/g dry cell weight (DCW) of astaxanthin. In order to increase production of astaxanthin in recombinant E. coli, we have cloned 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (lytB), farnesyl diphosphate (FPP) synthase (ispA), and isopentenyl (IPP) diphossphate isomerase (idi) in the isoprenoid pathway from E. coli and coexpressed these genes in recombinant E. coli harboring the astaxanthin biosynthesis genes. This engineered E. coli strain containing both isoprenoid pathway gene and astaxanthin biosynthesis gene cluster produced 1,200 ${\mu}g$/g DCW of astaxanthin, resulting 3-fold increased production of astaxanthin.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.174-174
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• 1994

항종양 물질의 탐색 및 연구 작업이 미생물을 대상으로 행해져 온것은 이미 오래전부터 이며, 기존의 연구 발표된 것들을 볼때 미생물 스크리닝의 증요성은 점차 증대되어가고 있다. 이에 본 연구에서는 국내 토양에서 방선균 약 1000여주를 분리하여 항종양 물질을 생산하는 방선군의 분리, 동전하고, 그 생산물질의 특성을 밝히고자 하였다. 방선균의 분리는 전국 각지에선 채집한 토양시료 각 1 g 씩을 80 $^{\circ}C$에서 90분간 건조처리한후 멸균된 증류수를 이용하여 각 단계별로 희석하여 Starch nitrate casein agar와 Glycerol asparagine agar를 사용하여 방선균을 분리하였다. 분리된 방선균을 Yeast extract-malt extract 액체 배지에서 7일간(160 rpm/28 $^{\circ}C$) 배양하였다. 여기에서 얻어진 배양액을 이용하여 항종양능을 확인한기 위해서 암세포주인 L1210주와 P388 D$_1$주, 정상 세포주로는 Vero 세포주를 이용한 MTT colorimetric assay를 이용하였다. 이들 실현에 대한 결과로써 S-104, 117, 409의 세 균주의 항종양물질 생산 균주를 분리하였다. 이들 균주가 생산하는 물질들은 기존의 시판 항암제인 Adriamycin에 비해 높게 나타났으며, 이들 균주의 동정은 ISP의 기준에 의하여 행하였다.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.2
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• pp.173-180
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• 2015

North Korea has developed ballistic missiles over the past 30 years. It is believed that they have a variety of ballistic missiles more than 1,000. Because these ballistic missiles threaten South Korea directly, accurate analysis of them is essential. Flight trajectories of the ballistic missiles are generally changed by means of adjusting payload weight, Isp, flight path angle, and cut-off time. The flight path angle is widely used to control the missile range. However it is difficult to predict the missile trajectory exactly in real operational environment because the missile could be launched according to its intention and purpose. This work analyzed the 1,000 km range MRBM's trajectory characteristics from adjusting flight path angle which is depressed as well as lofted method. The analysis of missile trajectory characteristics is based on the simulation of the missile trajectory model developed by KNDU research team.

• Journal of Korean Library and Information Science Society
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• v.43 no.1
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• pp.53-72
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• 2012

The purposes of this research are to search and analyze information theories which are useful to approach bibliotherapy in terms of 'therapeutic' readers' advisory service, and to propose a conceptual model of 'therapeutic' readers' advisory service on the basis of such theoretical foundations. To the end, Dervin's sense-making theory and Kuhlthau's ISP model are introduced and applied to the conceptual model. The conceptual model is profoundly based on Dervin's situation-gap-use metaphor and Kuhlthau's Uncertainty Principle.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.167-172
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• 2012

This paper aims on comparative analysis of measuring efficiency of occupied bandwidth between MRTG average traffic and internet real-time traffic by measuring the type of internet application service. Through this analysis, the user can measure their internet line and occupy a certain amount of bandwidth and will have to invest on how much is compared to MRTG maximum traffic graph. The result of measurement proved 1.4 times to 20 times occupied bandwidth error rate between real-time and average traffic by the type of internet services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3094-3097
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• 2009

The use of general-purpose divider is inevitable to implement a image down-scaler when an arbitrary scaling ratio is given. To get an output at every clock from the divider, the divider should be implemented by LUT, however, its hardware size will be bigger and bigger as the precision level is increased. In this paper, a new image scaling algorithm is presented for a arbitrary scaling ratio, which do not requires a general-purpose or LUT-based divider. The proposed algorithm utilizes only comparators and adders such that the hardware size can be reduced by 1/10 compared to the conventional approaches.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.807-808
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• 2010

To insert payload to the orbit over the 200km-altitude using launch vehicle which has 300sec the Isp, multi staging technique for launch is necessary. The range between the sea-level to the transfer orbit about 200~250km is for operation of 1st and 2nd rocket engines and the higher altitude is for propulsion system of the acceleration block and satellite. The upper stage rocket engine should have the high technology for entering the payload into the orbit precisely more than the performance for high thrust level. With this investigation of the upper stage rocket engines which have been used, we want to understand their development trend and prospect which is going to be references for the development of ours.