• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.464-473
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• 2016

The air temperatures of the coast and inland are rising due to an increase in carbon dioxide emissions and abnormal climate phenomena caused by global warming, El Nino, La Nina and so on. The sea levels of the Earth are rising by approximately 2.0 mm per year (global average value) due to the thermal expansion of sea water, melting of glaciers and other causes by global warming. On the other hand, when it comes to designing a hydraulic structure or coastal hydraulic structure, the standard of the design water level is decided by analyzing four largeness tide values and a harmonic constant with the observed tidal water level or simulating numerical model. Therefore, the design tidal water level needs to consider an increasing speed of the seawater level, which corresponds to the design frequency. In the present study, the observed tidal water levels targeting 46 tidal stations operated by the Korea Hydrographic and Oceanographic Administration (KHOA) from the beginning of observations to 2015 per hour were collected. The variation of the monthly and yearly and increasing ratio were performed and divided into 7 seas, such as east and west part of the Southern Sea, south part and middle of the East Sea, south part and middle of the Western Sea, and Jeju Sea. The current study could be used to determine the cause of local seawater rises and reflect the design tidal water level as basic data.

• Journal of the Economic Geographical Society of Korea
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• v.12 no.2
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• pp.195-214
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• 2009

The Mangi yoram("萬機要覽"), a guidebook of state affairs, was published by royal command in the late Joseon period. Its chapters on financial affairs(財用篇) are particularly remarkable, as they explain on all aspects of the national finance of the late Joseon period in a clear manner. The financial part of the Mangi yoram includes metallic mineral resources, such as the location of gold, silver, copper, lead deposits and the prosperity and decline of the mines, and the various uses of each of the minerals. These are still regarded as valuable resources. Its contents on agricultural geography comprise not only the total yearly output of grains, paddyfields and dryfields, their taxation and standards of taxation, but also ginseng which was famous in the outside world in the pre-modern era. The book also clearly explains distribution of agricultural dikes for irrigation and their functions. The book also contains information on forestry geography, e.g. the varieties of pine trees and their distribution and mountain containment policies. Contents related to commercial geography consist of material on different types of markets such as the yukuijeon(六矣廛), sijeon(市廛), peongsisuh(平市署), nanjeon(亂廛), and the distribution, size and prosperity and decline of the border markets of the northern frontier such as the hoeryungkaesi(會寧開市) and geongwonkaesi(慶源開市). Contents related to transport geography are the distribution and functions of government granaries etc. Obviously, this book contains detailed information on various aspects of Korean geography. If we try to understand the contents of this book from the framework of modern geographical classification schemes, the geographic information contained in the book assumes even greater significance. In sum one may conclude that this book, which the king kept by his side, contained useful geography related knowledge and necessary information, and was directly relevant to the administration of the country. It exerted immense influence on the contemporary intellectual world of Joseon Korea, and was regarded as an invaluable resource.

• Journal of Life Science
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• v.30 no.5
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• pp.460-467
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• 2020

Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed cancers in the word. Although radiation and chemotherapy are generally effective, there are various side effects that greatly limit the effectiveness of these treatments. Therefore, traditional herbs may have potential as important resources for the discovery of liver cancer therapeutics. In this study, we selected three Korean herbal medicine formulas from the Donguibogam, namely Bigihwan (BGH), Daechilgithang (DCGT), and Mokwhyangbinranghwan (MHBRH), and evaluated their anti-cancer effects on HCC cells. According to our results of three ethanol extracts, BGH was more effective at suppressing HCC growth than DCGT or MHBRH. Furthermore, flow cytometry analysis showed that inhibition of HCC proliferation by the three extracts was associated with the induction of apoptosis and autophagy. In particular, BGH significantly increased mitochondrial impairment and showed the possibility of inducing mitophagy in comparison with the other two extracts. BGH prominently upregulated the levels of microtubule-associated protein light chain-3 which was accompanied by a decrease in the expression of anti-apoptotic Bcl-2 without altering the expression of pro-apoptotic Bax. In addition, the levels of PTEN-induced kinase 1 were also markedly increased in BGH-treated HCC cells. Moreover, autophagy blocking improved cell viability and reduced apoptosis after the three treatments, indicating that autophagy by these extracts enhances HCC cells against cytotoxicity. In conclusion, our findings show that BGH demonstrates the highest anti-cancer activity among the three formulas and inhibits the proliferation of HCC cells through autophagy induction.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.48-48
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• 2011

2010년 약 19.5 GWp 의 규모로 성장한 태양광 시장의 주요 소재는 실리콘을 이용한 태양전지이며, 고성능 및 고효율 태양전지 시장이 급성장 하였다. 이러한 고품질 태양전지에 사용되는 주요 원료인 9N 급 폴리실리콘은 2008년 4월 $265/kg 까지 상승하였으나, 점차 하향안정세에 있으며, 급속한 가격 경쟁을 통해 당분간 장기공급가가 50$/kg 이하로 하락할 것으로 전망된다. 이러한 실리콘 제조기술 중 가장 많이 사용되는 기술은 Trichloro-silane (TCS) 또는 Mono-silane (MS)를 사용하는 기상법인 일명 Siemens 공정이다. 이러한 기상법의 경우 12N 이상의 초고품질 실리콘 제조가 가능하나, 대규모의 설비투자(1억원/폴리실리콘 1톤)와 높은 에너지(120 kWh/kg)가 요구된다. 이에 최근 기상법이 아닌 야금학적인 정련법에 대한 기술이 개발되고 있으며, 이는 금속 실리콘을 슬래그 처리, 편석 분리, 응고 급랭, 전자빔, 플라즈마 등을 이용하여 정련하는 공정을 말한다. 야금학적 정련법은 순도 면에서 기상법에 비하여 낮은 단점이 있음에도 불구하고, 여러 장점들로 인해 활발히 연구되며 점차 실용화 되고 있는 매우 유용한 기술이다. 야금학적 정련법의 주요 장점은 기상법에 비해 약 25% 정도의 설비 투자비로 가능하고, 금속 실리콘을 직접 사용하며, 에너지 payback이 짧다. 또한, 산 및 염화실렌을 사용하지 않으므로 환경 문제를 적게 야기하고, 생산설비의 확장성도 매우 높다. 본 연구에서는 국내 규석광을 이용하여 일련의 정련 공정을 거쳐 고순도SG(Solar Grade)급 실리콘을 제조하고자 하였다. 실리콘 용융 환원로를 개발하고 순도를 높이기 위해 슬래그정련법을 이용하였으며, 생산된 3N 급의 금속 실리콘을 비기상법정련 방식인 일방향 응고와 플라즈마 정련 및 전자기유도 용해법을 이용하여 고순도의 실리콘을 제조하였다. 본 연구에서는 상업생산을 개시한 외국의 E사와 비교하여 산침출공정을 거치지 않으므로 실리콘회수율 및 환경부하 절감의 장점을 갖고 있으며 최종 순도 실리콘 6N 이상, 보론 함유량 0.2 ppm 이하를 달성하였으며, 기존 기상법 대비 약 20%의 전력 감소와 약 13%의 금속실리콘 원료 절감 효과가 있었다. 저가/고순도 SG급실리콘의 제조기술 개발은 향후 세계 태양광 시장에 대한 경쟁력을 확보하고, 시장 점유율 상승에 기여할 수 있으며, 산업 확대를 통한 주변 산업으로의 파급 효과가 매우 클 것으로 예상된다.

• Journal of Life Science
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• v.25 no.5
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• pp.607-614
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• 2015

Cancers are the largest cause of mortality and morbidity all over the world. Cordycepin, an adenosine analog, is a major functional component of the Cordyceps species, which has been widely used in traditional Oriental medicine. Over the last decade, this compound has been reported to possess many pharmacological properties, such as an ability to enhance immune function, as well as anti-inflammatory, antioxidant and anti-cancer effects. Recently, numerous studies have reported interesting properties of cordycepin as a chemopreventive agent as well. There is an accumulating body of experimental evidences suggesting that cordycepin impedes cancer progression by promoting apoptosis, inducing cell cycle arrest, modulating intracellular signaling pathways, and inhibiting invasion and metastasis of cancer cells. In many cancer cell lines, cordycepin inhibits growth and cell cycle progression by inducing arrest of the G2/M phase, resulting from the inhibition of retinoblastoma protein phosphorylation and induction of cyclin-dependent kinase inhibitors. To induce apoptosis, cordycepin activates the extrinsic and intrinsic pathways, which promotes reactive oxygen species generation and the downstream activation of kinase cascades. Cordycepin also can activate alternative pathways to cell death such autophagy. In addition, cordycepin can inhibit the pro-metastatic processes of cancer cell detachment, migration, and invasion through a variety of mechanisms, including the nuclear factor-kappa B and activated protein-1 signaling pathways. In this review, we summarized the variety of action mechanisms by which cordycepin may mediate chemopreventive effects on cancer and discussed the potential of this natural product as a promising therapeutic inhibitor of cancer development.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.134-139
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• 2010

Mycobacterium tuberculosis (Mtb) is one of the most successful pathogens to infect one third of world population. Th1-mediated immunity against Mtb infection is known as critical to express mycobacteriostatic function but it is not sufficient to resolve the infection. In this study, to verify the possibility Mtb itself change the gene expression to survive against host immune response, expression pattern of selected H37Rv genes, 16S rRNA, acr, fbpA, aceA, and ahpC, during the course of infection was measured with absolute quantitation method using real-time RT-PCR. The total number of transcripts of 16S rRNA increased during the course of infection, which was coincide with the increasing CFU. The total number of fbpA transcripts per CFU, which encode typical secreted Mtb antigen, Ag85A, increased for 10 days of infection before decreasing. The number of transcripts of acr per CFU, which encode heat shock protein, ${\alpha}$-crystallin, increased during the infection, and ahpC and aceA, they both are enzymes produced in oxidative stressful condition, increased for 20 days and then slightly decreased on day 30. These findings are one of survival strategy of pathogen evading host immune response lead to persistent infection inside host cells.

• Journal of the Korean association of regional geographers
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• v.14 no.2
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• pp.93-104
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• 2008

This article will divide agricultural change process in Yanbian area into the period of japan rule, socialism and later time of the reform and open policy and so on. It will analyze the changes of Yanbian agriculture in every period influenced by external environment influence. The conclusions are as follow: first, under the influence of the japan rule, the policy about Korean Minority immigrants in japan and the original work agriculture and the group tribe construction, Yanbian fanning was controlled by the Japanese. Therefore, Yanbian's agriculture became the tool to satisfy the war and plunder the resource for Japanese. It shows the obviously peripheral characteristics. Second, in socialism time, Yanbian's agriculture was influenced by the rural communalization. The fanning completely belongs to the country, the agricultural production is influenced by the idea of "grain as the key link" which it only pays attention to take the cultivation industry and the production of grain in the interior of cultivation industry. Therefore, it has not been able fully to use the rich natural resource. Third, after reform and open policy, the countrysides were implemented family contract responsibility system, the farmer can rent the land for a long time, and the enthusiasm of agricultural production was improved. Moreover, due to the social market economy-system, the farmer carried on the agricultural production activities according to the market's demands and various departments of the agriculture obtained the coordinate development.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.926-929
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• 2014

In Korea MVNO was introduced in 2011 when twenty seven years had passed since Korea Mobile Telecom started mobile phone service in 1984. Whithout having its frequency bands and network facilities MVNO can resell the mobile telecom services to the consumers by purchasing MNO's service. That can bring competition more efffective that can lower communication costs through the alternatives. In the early 2000s, the need for the introduction of the MVNO has been raised already by scholars in Korea. But it wasn't until the late 2000s, rate cuts appeared to be a major policy issue, and in 2011 Korean government begin to try to introduce its own MVNO's. In may 2014, MVNO's mobile communication market share reached 6%, but Korea dose not have a firm system yet. However, if government authorities did not insist 3 mobile telecom companies system and recognize global MVNO flow quickly the national cost would be significantly reduced. In the mean time mobile telecom companies have maintained similar billing system and level of service but competed to attract consumers only. It looks like some level of mutual collision and the government cannot help recognizing the situation but it did not do any effective policy improvement effort and government only levied penalties.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.554-561
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• 2022

Technology development related to maritime autonomous surface ships (MASS) is actively progressing around the world. However, since there are still many technically unresolved problems such as communication, cybersecurity, and emergency response capabilities, it is expected that it will take a lot of time for MASS to be commercialized. In this study, we proposed a ship group navigation system in which one leader ship and several follower ship are grouped into one group. In this system, when the leader ship begins to navigate, the follower ship autonomously follows the path of the leader ship. For path following, PD (proportional-derivative) control is applied. In addition, each ship navigates in a straight line shape while maintaining a safe distance to prevent collisions. Speed control was implemented to maintain a safe distance between ships. Simulations were performed to verify the ship group navigation system. The ship used in the simulation is the L-7 model of KVLCC2, which has related data disclosed. And the MMG (Maneuvering Modeling Group) standard method proposed by the Japan Society of Naval Architects and Ocean Engineering (JASNAOE) was used as a model of ship maneuvering motion. As a result of the simulation, the leader ship navigated along a predetermined route, and the follower ship navigated along the leader ship's path. During the simulation, it was found that the three ships maintained a straight line shape and a safe distance between them. The ship group navigation system is expected to be used as a navigation system to solve the problems of MASS.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.177-200
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• 2017

This writer have thus far reviewed the civil and criminal obligations of the directors of a parent company that sponsored financially troubled affiliates. What was discussed here applies to logistics companies in the same manner. Hanjin Shipping cannot expect its parent company, Korean Air to prop it up financially. If such financial aid is offered without any collateral, under Korean criminal law, the directors of the parent company bears the burden of civil and criminal responsibility. One way to get around this is to secure fairness in terms of the process and the content of aid. Fairness in terms of process refers to the board of directors making public all information and approving such aid. Fairness in terms of content refers to impartial transactions that block out any possibilities of the chairman of the corporate group acting in his private interest. In the case of Korean Air bailing out Hanjin, the meeting of board of directors were held five times and a thorough review was conducted on the risks involved in the loans being repaid or not. After the review, measures to guard against undesirable scenarios were established before finally deciding on bailing out Hanjin. As such, there are no issues. In terms of the fairness of content, too, there were practically no room for the majority shareholder or controlling shareholder to pocket profits at the expense of the company. This is because the continued aid offered to a financially troubled company (i.e. Hanjin Shipping) was a posing a burden to even the controlling shareholder. This writer argues that the concept of the interest of the entire corporate group needs to be recognized. That is, it must be recognized that the relationship of control and being controlled between parent company and affiliate company, or between affiliate companies serves a practical benefit to the ongoing concern and growth of the group and is therefore just. Moreover, the corporate group and its affiliates, as well as their directors and management must recognize that they have an obligation to prioritize the interests of the corporate group ahead of the interests of the company that they are directly associated with. As such, even if Korean Air offered a loan to Hanjin Shipping without collateral, the act cannot be treated as an offense to law, nor can the directors be accused of damages that they bear the responsibility of compensating under civil law.