• Journal of Electrical Engineering and Technology
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• 제12권6호
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• pp.2089-2098
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• 2017

Microgrid is a convenient, reliable, and eco-friendly approach for the integration of Distributed Generation (DG) sources into the utility power systems. To date, AC microgrids have been the most common architecture, but DC microgrids are gaining an increasing interest owing to the provision of numerous benefits in comparison with AC ones. These benefits encompass higher reliability, power quality and transmission capacity, non-complex control as well as direct connection to some DG sources, loads and Energy Storage Systems (ESSs). In this paper, main challenges and available approaches for the protection of AC and DC microgrids are discussed. After description, analysis and classification of the existing schemes, some research directions including coordination between AC and DC protective devices as well as development of combined control and protection schemes for the realization of future hybrid AC/DC microgrids are pointed out.

• 한국건축시공학회지
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• 제9권1호
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• pp.75-80
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• 2009

The Korean society, which faces a new issue of foreign labores, is actively conducing safety consciousness of foreign labors. Foreign labors of domestic industry reached about 360,000 recently. it has become the essential resources to fill up insufficient labor in construction industry. Although most foreign labors participate in safety education well and understand its object, some foreign labors have negative recognition of it. Some foreign labors well comprehend the importance of safety facilities but think those unnecessary. Based on these results, this research pointed out the need to review training manuals, the development of educational programs, improvement of educational facilities to improve safety education of construction, and finally to discussed these issues.

• 한국항만학회지
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• 제10권1호
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• pp.25-36
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• 1996

Generally, it is pointed out that a nonlinear analysis is needed to estimate accurately the water surface fluctuation and dynamic responses of a floating structure in case of large wave reflection. In this study, a frequency-domain method is applied and newly developed to analyze the nonlinear characteristics of the air-chamber floating breakwater. The air-chamber floating breakwater in this study can control well the wave transformation, motions of the structure and its natural frequency by adjusting the air depth in the chamber. Experiments are carried out to verify the numerical results. It is appeared that the mean water level is setup in the anti-node and setdown in the node, while the nonlinearity in wave profile is larger in the node than in the anti-node. Because of vertical mooring system, the sway, especially the time-independent nonlinear component, plays predominant role in the motion. On the other hand, the time-dependent component, as well as the time-independent one to the tensile force of mooring line contributes greatly, and the time averaged value presents tensional force oriented to the onshore side due drift force.

• Geomechanics and Engineering
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• 제15권1호
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• pp.677-686
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• 2018

Aimed at serious casing damage problem during the process of oilfield development by injecting water, based on seepage mechanics, fluid mechanics and the theory of rock mechanics, the multi-physics coupling theory was also taken into account, the mathematical model for production of petroleum with water flooding was established, and the method to solve the coupling model was presented by combination of Abaqus and Eclipse software. The Q9G3 block in Jibei oilfield was taken for instance, the well log data and geological survey data were employed to build the numerical model of Q9G3 block, the method established above was applied to simulate the evolution of seepage and stress. The production data was imported into the model to conduct the history match work of the model, and the fitting accuracy of the model was quite good. The main mechanism of casing damage of the block was analyzed, and some wells with probable casing damage problem were pointed out, the displacement of the well wall matched very well with testing data of the filed. Finally, according to the simulation results, some useful measures for preventing casing damage in Jibei oilfield was proposed.

• 한국빅데이터학회지
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• 제4권1호
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• pp.1-10
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• 2019

FTA가 확산됨에 따라 향후 급증할 것으로 예상되는 실제조사 등을 대비하여 국내거래 단계에서 원산지 정보의 정확성과 신뢰도 증진 필요성이 높아지고 있다. 그러나 현실적으로 원산지 관련 정보를 수집 및 관리하는데 있어 많은 문제점을 내포하고 있다. 이는 FTA 활용이익의 수출자 편향성과 발급유인 부족 등과 함께 국내 제조기업들의 원산지 정보유통과 관리기술에 관한 부족도 중요한 원인으로 지적되고 있다. 본 논문에서는 프라이빗 블록체인인 Hyperledger Fabric을 사용하여 원산지정보 관리시스템 프로토타입 구축을 통해 국내 기업들의 원활한 FTA원산지 (포괄) 확인서의 관리 및 유통의 효율성을 증진하고, 조작방지를 통한 신뢰성 증진을 지원하는 방안을 제시한다. 블록체인은 분산원장 혹은 신뢰 인터넷으로 불리면서 공급망 상에서 여러 관련기업들이 원산지 정보를 높은 신뢰성을 가지고 즉시 유통할 수 있는 기술적인 인프라를 제공하지만 아직 이의 실제 비즈니스 적용에 관한 연구는 시작단계에 머물러 있다.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2008년도 춘계학술발표대회 논문집
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• pp.323-327
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• 2008

The population of the elderly and elderly living alone goes on increasing. Most elderly does not want to move into another place out of their present living environment. So it is essential to know their living conditions for the quality of living, especially the aged living alone out of their children' care. Unfortunately there is scarcely any house designed for the aged, especially elderly living alone until now. So this study investigated the living environment of the elderly living alone in gunsan city. The ratio of the female aged living alone is about 3 times than the male but the male population is increasing. Most of them are troubled with more than a disease and use aids and feel the necessity of the others' help. The ratio of the absolute poverty among the elderly living alone is about 30%. The majority of them are almost 65-84 years old with living detached house. Most of them own their house. They living in detached house are of a mind to remodel bath/toilet first of all and they living in apartment or row houses have a intention of remodeling an air conditioner and paper walls and ceiling and flooring of all things in house. As the bath and restroom have been pointed as a dangerous space for elderly, the elderly living alone pointed out them as to be remodeled. It seemed the air conditioner in house do not work well in view of their poor economic condition. For the elderly It is needed economic and institutional supports of private organization or government.

• Korean Journal of Acupuncture
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• 제22권4호
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• pp.175-185
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• 2005

Objective : The skill of locating acupoints accurately is an essential part of acupuncture treatment. Bone-scale has been used as a basic coordinates to locate acupoints and has been considered as an important factor of locating acupoints. This study was designed to stress the impotance of QieXunMenAn, which means pressing and rubbing softly the surface around the part pointed with proportional method, in locating acupoints. Methods and results : All expressions related with QieXunMenAn, among the descriptions of acupoint locations in ${\ulcorner}Zhenjiudacheng{\lrcorner}$, were investigated. The activity of QieXunMenAn has been regarded as an important method of locating acupoints since Neijing. QieXunMenAn means pressing and rubbing softly the surface around the part pointed with proportional method. It is a process of locating acupoint in detail by finger-sensation after locating the point with proportional method. Xianzhang, Dongmaiyingshou, and Wanwanzhong have been used to describe how to locate acupuncture-point through QieXunMenAn procedure. Xianzhong means a small depression or a pit on the surface of the body. Wanwanzhong describes that it feels very soft and tender. Descriptions related with QieXunMenAn procedures were found in around 87% of acupoint locations, thus stressing out its procedure. Conclusions : Bone-scale and QieXunMenAn do not mean different methods but the procedures that should be both performed every time when we locate most of the acupoints. Until recently, QieXunMenAn has been paid less attention that it should be. OieXunMenAn as well as bone-scale may be necessary to help locate acupoints accurately.

• 한국수산과학회지
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• 제5권4호
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• pp.121-127
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• 1972

한국산 가자미과어류의 미설골의 형태를 비교 관찰하여 다음과 같은 특질을 가지고 있음을 알았다. 1. 좌골부선단의 위치가 속 또는 종에 따라 달리하고 있는데, 주부의 선단에서 각을 이루는 부분까지의 거리의 1/2(Platichthys 및 Cleisthenes), 앞쪽에서 1/3(Eopsetta 및 Tanakius), 뒷쪽에서 1/4(Verasper 및 Dexistes), 동일위치 (Limanda, Clidoderma, Glyptocephalus 및 Microstomus), 2배의 거리 (Kareius 및 Pleuronichthys)에 있는 것등으로 나누어지며 , 좌골부선단의 모양은 절두형인 것(Eopsetta, Verasper, Limanda, Platichthys, Tanakius 및 Glyptocephalus), 끝이 뾰족하고 위로 향한 것(Kareius, Pleuronichthys, Clidoderma 및 Microstomus), 끝이 뾰족하며 앞으로 향한 것(Cleisthenes 및 Dexistes)등 세가지형으로 나누어진다. 2. 분문돌기는 발달정도에 따라 차이가 있고 그 모양도 다양하다. 비교적 큰 것에 속하는 것(Eopsetta, Verasper, Platichthys, Tanakius, Kareius 및 Dexistes), 작은 것(Pleuronichthys 및 Clidoderma), 막대기 모양인 것(Glyptocephalus), 보통인 것(Limanda, Microstomus 및 Cleisthenes)등 의 네가지로 나누어지며, 모양은 상연이 둘로 갈라져 날개 모양을 한 것(Eopsette, Verasper, Limanda, Platichthys, Tanakius, Glyptocephalus, Kareius, Pleuronichthys 및 Clidoderma), 끝이 뾰족한 것 (Microstomus 및 Cleisthenes), 절두형에다 내연이 발달한 것(Dexistes) 등 세가지로 나누어진다. 3. 주부와 좌골부가 만드는 각도는 Pleuronichthys, Clidoderma, Microstomus의 반타원형을 제외하고는 $30^{\circ}$에서 $60^{\circ}$까지의 각도를 이루고 있다.

• 한국산림과학회지
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• 제105권2호
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• pp.238-246
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• 2016

본 연구는 Post-2020을 대비하는 일본의 REDD+의 국가전략과 각 기관별 추진현황을 파악하고, JCM(Joint Credit Mechanism) REDD+ 가이드라인의 문제점에 대한 우리나라 REDD+의 대응 방안 및 시사점을 제시하는 것을 목적으로 한다. JCM-REDD+ 가이드라인의 기술적 한계를 보면, REDD+ 사업의 대상이 되는 산림의 적합성은 세이프가드 간섭이 적은 곳을 선점하는 문제가 있으며, 참조배출기준선의 설정은 기준연도에 따라서 추세선이 변화하기 때문에 배출량 차이가 발생할 수 있다. 또한, REDD+의 배출이동(누출)은 누출지역이 발생하였을 때, 누출면적과 관계없이 일정계수를 곱하여 산출하기 때문에 불확실성을 포함하고 있으며, 모니터링 실시방침은 국가 및 준국가 단위의 방법만을 제시하고 있어 프로젝트 단위의 방법론이 필요하다. 마지막으로 세이프가드에 대한 방침은 세부사항 없이 목록으로만 제시하고 있어 국제통용의 항목 규정이 필요하다. 이와 같은 문제점들은 크레딧의 분배와 계층적접근(Nested Approach) 등의 더블카운팅(Double Counting) 문제와도 관련이 있으며, 앞으로 우리나라는 이를 고려하여 REDD+ 사업을 시행해야 할 것이다.

• 한국수학사학회지
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• 제5권1호
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• pp.81-95
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• 1988

In Akhakkyebom(낙학궤범), one of the greatest Korean Sources, a great mistake was found in the lengths of the pitch pipes. Whanjong(황종) from which the other eleven pitches are calculated, is nine inches by decimal system. But the rest are from 9inches by nonary system. To find out how such a contradictory combination could put into so great a book, all the sources available wereexamined. In the process of investigating the numeral change of the lengths of the pitchpipes, it was found that fixation of this contradictory combination was due to the tradiction of Confucianism, which is specialized by its adherence of the old. SongHyon(성현) couldn't understand well enough Tsai Yuan-ting's(몽원정) Account of the science of the pitch pipes in Lu-luhsin-shui(율여신서), Neither could Yi Hye-gu(이혜구) who translated Akhakkwebom(낙학궤범) into Korean. The parts they misunderstood were pointed out and explained as it should be in this thesis. Several other accounts of the science of the pitch pipes like Chu Tsai-yu's and Jing Farng's are also explained. The Pitch-pipes which were said to have been made by Pak Yon(박연) were found out to be of Chu Tsai-yu's. Those which Yi Sang dok(이상덕) wrote were one of Pak Yon's achievements turned out to be of Tsai Yuen-ting's(몽원정), And othe interesting mistakes were pointed out in thesis thesis. Most of these mistakes were made, I think, because of the lack of the study on the historical background. That's why I tried to examine all the sources available on pitch-pipes. In the lengths of the pitch-pipes preserved in Shih-chi(사기) by Ssu-ma Ch'ien(사마천), several letters were found to have been misprinted. Some 칠's should be “십” and the letter “일” in Hyopchong(황종) should be “칠”. I couldn't deal with all the lengths of the pitch-pipes in this thesis. Especially the real length of the old measure of Whangjong(황종) made by PakYon(박연) is remained still unknown. I believe a lot more study should be poured on this field to know our traditional music as it was.