• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2012년도 추계학술대회
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• pp.84-85
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• 2012

지속적인 유가 상승과 탄소배출 규제 강화는 기업들로 하여금 높은 경쟁력을 가지도록 요구한다. 따라서 고객 서비스 증대와 비용절감을 위해 효율적인 물류시스템을 구축하고 운영하는 것에 많은 노력을 기울이고 있으며 경쟁력을 가지는 물류단지의 필요성이 증대되고 있는 실정이다. 이러한 물류도시를 구축하기 위해서는 적절한 정책과 화물수송 공동화를 통한 물류시스템이 필요하다. 특히, 단지내 물류시스템의 체계구축을 통한 효율적인 운영은 저비용 친환경적인 측면에서 매우 중요하다. 따라서 본 연구에서는 물류단지내 효율적 운송을 위한 물류네트워크를 운영 모델을 제시하고 특히 운송 다단화 단계를 통해 문제에 접근하고자 한다.

• 한국기계가공학회지
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• 제18권8호
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• pp.60-66
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• 2019

This study aims to develop and manufacture a device for inspecting impurities in a sealed aluminum container using an X-ray technique. Two X-ray oscillators and detectors are used to detect the entire sample. The stage for sample movement was fabricated using two high-voltage generators and X-ray detectors arranged diagonally. In addition, the high-voltage generator is composed of a vacuum tube, a high-voltage generator, and circulating oil for cooling. It includes a control unit for controlling other equipment, a power supply unit, and a video output unit; the most important part of the X-ray is the X-ray generation part. In this study, a flat panel was used along with the aim of developing the detector part. In particular, the development of the scintillator introduced in this study is a primary focus. The developed scintillator can be combined with a lens and can then be assembled with a charge coupled device (CCD) sensor.

• 무역학회지
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• 제44권5호
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• pp.127-142
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• 2019

As Korea's steel industry exports 38 percent of its total steel production, the future management environment of the steel industry will change depending on the outcome of the FTA negotiations. The overall industrial structure of the domestic steel industry depends on the rules of origin, which are directly linked to the effect of concessionary tariffs. Therefore, negotiations on rules of origin are as important as tariff liberalization for Korea's steel industry. Korea's cold-rolled and plated companies are expected to be negatively affected as the country of origin standards of steel products have not considered the steel production processes in Korea. In future FTA talks, the country of origin rules should be agreed on a change of tariff classification basis. This result would secure a stable export market through increased predictability of steelmakers and reduce the risk of increased costs of oil and intangible products. In addition, the government should consider the structure of domestic supply and demand so that it does not impose constraints on the change of tariff classification. Finally, participants in the negotiations should consider the opinions of the domestic steel industry.

• 한국안전학회지
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• 제36권4호
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• pp.1-11
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• 2021

Piping systems comprising pumps and valves are essential in the power plant, oil, and defense industry. Their purpose includes a stable supply of the working fluid or ensuring the target system's safe operation. However, piping system accidents due to leakage of toxic substances, explosions, and natural disasters are prevalent In addition, with the limited maintenance personnel, it becomes difficult to detect, isolate, and reconfigure the damage of the piping system and recover the unaffected area. An autonomous recovery piping system can play a vital role under such circumstances. The autonomous recovery algorithms for the piping system can be divided into low-pressure control algorithms, hydraulic resistance control algorithms, and flow inventory control algorithms. All three methods include autonomous opening/closing logic to isolate damaged areas and recovery the unaffected area of piping systems. However, because each algorithm has its strength and weakness, appropriate application considering the overall design, vital components, and operating conditions is crucial. In this regard, preliminary research on algorithm's working principle, its design procedures, and expected damage scenarios should be accomplished. This study examines the characteristics of algorithms, the design procedure, and working logic. Advantages and disadvantages are also analyzed through simulation results for a simplified piping system.

• The Journal of Asian Finance, Economics and Business
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• 제9권8호
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• pp.7-17
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• 2022

The article discusses the problems caused by inflation in the developing Asia-Pacific region during the time of the worldwide pandemic and suggests innovative solutions to the problem. The reality is that some of the commodity groups from the consumer basket (e.g., non-seasonal fruits, electronics, furniture, hotel, and restaurant services, etc.) fail to reflect the needs of the low-income earners, which make the majority in developing countries. At the same time, the inflation targeting regime has become outdated and not reliable, because of uncontrolled exogenic factors (imported inflation, fluctuation in oil prices, supply chain disruption, Russia-Ukraine war, etc.) prevailing on endogenic factors and thus making it impossible to control the price stability, especially in developing countries. Since, the old-fashioned inflation index and inflation targeting mechanisms regrettably fail to fully reflect both the society and governmental/central banks' expectations, based on which we first should have better care and second create better policies; we propose to use a combination of already well-known indexes and policies, with the new statistical indicators, which reflects price fluctuations on the medication, utilities, and nutrition.

• 한국화재소방학회논문지
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• 제31권5호
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• pp.53-62
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• 2017

경제 및 산업의 원천 에너지원인 전력은 생산과 소비의 지역적 상이함으로 장거리 수송을 필수로 하며, 다중환상망(Multi-loop) 형식의 송배전계통으로 전력을 공급한다. 실질적 사용에 앞서, 변전소내 변압기를 통해 변전과정을 거쳐 각 사용처의 특성을 고려하여 전력공급이 이루어지고 있으며 변압기는 본체, 권선, 절연유, 부싱등의 구조로 결합되어 있다. 변전소에서 발생하는 변압기화재는 가구와 상업시설등에 전기공급을 중단시키고 각종 안전사고를 발생시키는 1차 손실뿐만 아니라 2차적으로 경제 손실을 야기한다. 화재의 원인은 부싱 하부파손에 따른 절연유 유출과 약 1초 이내 발화점에 도달하는 절연유에 의한 화재의 연쇄반응으로 파악된다. 화재피해의 최소화를 위해 연기감지기, 자동소화설비 등이 구축되어있으나 감지기의 동작 및 소화가스 방출지연 등으로 화재진화를 위한 골든타임 확보의 부재가 문제되고 있다. 이에 본 연구는 초기 화재진화에 따른 골든타임 확보의 중요성에 따라 화재확산을 방지하고 절연유 누출을 차단하는 능동적 메커니즘의 필요에 따라 수행되었다. 따라서 화염에 의해 팽창하는 고온형상 유지물질과 기계적 화염차단장치를 적용한 부싱방화구조체를 개발하였다. 실제 부싱 및 프렌지규격을 적용하여 제작된 변압기모형에 부싱방화구조체를 설치하여 실규모 화재실험을 수행하였다. 초기화염으로부터 3초내에 정확한 위치와 높이에 부싱방화구조체가 작동함을 확인하였으며 이는 실제 변압기화재 시 화염 확대를 효과적으로 차단할 수 있을 것으로 사료된다.

• 비파괴검사학회지
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• 제14권2호
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• pp.122-131
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• 1994

일반적으로 회전기기의 저어널 베어링 부분은 윤활유 공급의 부족이나 윤활층에 이물질이 혼입되면 시스템의 고장이나 가동중단 등의 원인이 되기도 한다. 따라서 베어링 손상에 기인하는 사고와 관련된 안전운전 문제와 유지비용의 절감을 위해 여러가지 파괴 및 비파괴시험법들이 사용되어 왔다. 본 연구에서는 저어널 베어링에서 가장 발생하기 쉬운 윤활층에의 이물질 혼입에 의해 야기되는 베어링 파손의 조기검출을 위해 음향방출 기술을 적용하였으며, 전보의 연구에 이어 좀더 정량적이고 체계적인 실험을 수행하였다. 실험실용으로 직접 제작한 모의 베어링 시스템을 이용하여 여러 형태의 인위적인 이물질 혼입 상태를 만들어 실험하였으며 베어링 손상 및 결함 형태의 해석을 위해 AE rms level, 파형분석, AE 변수 등의 여러 파라메터를 사용하여 분석 고찰하였다. 그 결과 AE rms level의 변화가 이물질 혼입의 영향에 민감함을 보여주었으며 AE 변수 등 다른 정보들로부터 손상 원인별로 신호형태를 확인할 수 있었다.

• 한국석유지질학회지
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• 제7권1_2
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• pp.19-27
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• 1999

에너지 자원의 빈국인 한국은 에너지 자원의 기본적인 사용량 중에서 절대적인 양을 차지하는 석유 및 천연가스를 $100{\%}$수입에 의존하고 있다. 정부가 유사시 즉각적으로 실시하여야 할 중요한 역할 중의 하나가 이와 같은 유용한 에너지 자원을 다양하게 확보하는 것이다. 가스 하이드레이트는 천연가스와 다론 형태의 에너지로서 그 매장량이 해양이나 영구동토지역 등 전세계적으로 분포되어 있으므로 가까운 미래의 천연가스 대체 자원으로서 주목을 받고 있다. 특히 한반도 주변의 동해에 많은 양의 가스 하이드레이트가 매장되어 있을 것으로 기대된다 따라서 이 논문에서는 국내외 연구 및 기술개발 동향을 검토하여 탄성파 탐사를 통한 해석, 가스 하이드레이트의 특성 및 물리적인 물성, 그리고 가스 하이드레이트의 활용 기술 등에 관련된 국내의 중장기적인 가스 하이드레이트의 기본적인 연구 및 기술개발에 대하여 전체적인 프로젝트의 개요를 설명하였다.

• 환경위생공학
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• 제7권2호
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• pp.1-10
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• 1992

Since 1960's along with industrialization and urbanization, economic growth has been . achieved, however, at the same time, environmental condition has been seriously deteriorated. . Currently, volume of wastewater has been increasing at annual rate of 7% in sewage and 20% in industrial wastewater. However, the nation's sewage treatment serves only 33% of the municipal wastewater as of 1991. Major portion of air pollutants comes from combustion of oil and coal which comprise 81% of total energy use and emission gases from motor vehicles increasing at an accelerated rate. It is known that Korea generates the highest amount of waste per capta. Nevertheless, it is not sufficient to reduce the volume of waste by means of resources recovery and recycling. Recognizing the importance of global environmental problems such as ozone layer depletion, global warming and acid rain, international society has been making various efforts since the 1972 Stockholm conference. In particular, it is expected that the Rio conference which has adopted the Rio declaration and Agenda 21 will form a crucial turning point of the emerging new world order after the Cold War confrontation. To cope with such issues as domestic pollution and global environmental problems, the fundamental national policy aims at harmonizing "environmental protection and sustainable development". The Ministry of Environment has recently set up a mid-term comprehensive plan which includes annual targets for environmental protection. According to the government plan, gradual improvement of various environmental conditions and specific measures to achieve them is planned in time frame. Additional sewage treatment plants will be constructed in urban areas with the target to treat 65% of the nation's municipal sewage by 1996. Supply of clean fuels such as LNG will also be expanded starting from large cities as a cleaner substitute energy for coal and oil. In parallel with expansion of LNG, emphasis will be placed on installation of stack monitoring system. Due to the relatively limited land, government's basic policy for solid waste treatment is to develop large scale landfill facilities rather than small sized ones. Thirty three regional areas have been designated for the purpose of waste management. For each of these regions, big scale landfill site is going to be developed. To increase the rate of waste recycling the government is planning to reinforce separate collection system and to provide industries with economic incentives. As a part of meeting the changing situation on global environmental problems after UNCED, and accommodation regulatory measures stipulated in the global environmental conventions and protocols, national policy will try to alter industrial and economic structure so as to mitigate the increasing trends of energy consumption, by encouraging energy conservation and efficiency. In this regard, more attention will be given to the policy on the development of the cleaner technology. Ultimately, these policies and programs will contribute greatly to improving the current state of national public health.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.56-61
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• 2009

Paradigm depending only on fossil fuel for building heat source is rapidly changing. Accelerating the change, as it has been known, is obligation for reducing green house gas coming from use of fossil fuel, i.e. reaction to United Nations Framework Convention on Climate Change. In addition, factors such as high oil price, unstable supply, weapon of petroleum and oil peak, by replacing fossil fuel, contributes to advance of environmental friendly renewable energy which can be continuously reusable. Therefore, current new energy policies, beyond enhancing effectiveness of heat using equipments, are to make best efforts for national competitiveness. Our country supports 11 areas for new renewable energy including sun light, solar heat and wind power. Among those areas, ocean thermal energy specifies tidal power generation using tide of sea, wave and temperature differences, wave power generation and thermal power generation. But heat use of heat source from sea water itself has been excluded as non-utilized energy. In the future, sea water heat source which has not been used so far will be required to be specified as new renewable energy. This research is to survey local heating system in Europe using sea water, central solar heating plants, seasonal thermal energy store and to analyze large scale central solar heating plants in German. Seasonal thermal energy store necessarily need to be equipped with large scale thermal energy store. Currently operating central solar heating system is a effective method which significantly enhances sharing rate of solar heat in a way that stores excessive heat generating in summer and then replenish insufficient heat for winter. Construction cost for this system is primarily dependent on large scale seasonal heat store and this high priced heat store merely plays its role once per year. Since our country is faced with 3 directional sea, active research and development for using sea water heat as cooling and heating heat source is required for seashore villages and building units. This research suggests how to utilize new energy in a way that stores cooling heat of sea water into seasonal thermal energy store when temperature of sea water is its lowest temperature in February based on West Sea and then uses it as cooling heat source when cooling is necessary. Since this method utilizes seasonal thermal energy store from existing central solar heating plant for heating and cooling purpose respectively twice per year maximizing energy efficiency by achieving 2 seasonal thermal energy store, active research and development is necessarily required for the future.