• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.296-296
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• 2016

한강유역의 다목적댐인 소양강댐, 충주댐, 횡성댐의 운영이 하류부에 미치는 조절효과를 분석하기 위해 3개의 다목적댐이 모두 운영되고 있는 현재의 유역상황과 소양강댐, 충주댐, 횡성댐이 각각 없을 경우를 가정하여 시나리오별로 팔당댐 지점에서 유황곡선 차이를 검토함으로써, 3개 다목적댐의 조절효과를 정량적으로 분석하였다. 각 시나리오별 유출분석시 소양강댐, 충주댐, 횡성댐의 운영이 이루어질 경우에는 각 댐의 방류량 자료가 모형에 고려되도록 하였으며, 반대로 댐 운영이 이루어지지 않을 경우에는 각 댐의 유입량 자료가 모형에 반영되도록 하였다. 또한, 북한강 본류구간에 위치한 의암댐과 청평댐에 대해서는 발전용댐이기 때문에 유입량이 모두 방류되는 것으로 가정하여 적용하였다. 분석기간은 횡성댐의 자료 기간을 고려하여 2001~2009년을 선정하였으며, 시나리오별 각 댐의 조절효과를 정량화하기 위해 하류부인 팔당댐 지점에서의 유황곡선 차이를 계산하여 비교하는 방법을 이용하였다. 소양강댐 운영에 따른 팔당댐 지점에서의 조절유량은 약 10.3억$m^3$이며 조절기간은 304일로 분석되었고, 충주댐 운영에 따른 조절유량은 약 11.9억$m^3$에 조절기간은 336일, 횡성댐 운영에 따른 조절유량은 약 0.53억$m^3$에 조절기간은 303일로 분석되었다. 3개 다목적댐이 모두 운영될 경우의 유황 조절효과는 약 22.5억$m^3$에 333일로 분석되었다.

• Geomechanics and Engineering
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• 제28권2호
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• pp.145-155
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• 2022

Safety is a most important parameters in underground railway transportation; Also stability of underground tunnel is very important in tunneling engineering. Design of a reliable support system requires an evaluation of both ground demand and support capacity. Iran's traditional railway tunnels are mainly supported with masonry structures or unsupported in high quality rock masses. A decrease in rock mass quality due to changes in groundwater regime creep and fatigue in rock and similar phenomena causes tunnel safety to decrease during time. The case study is an old tunnel in Iran, called "Keshvar"; it is more than 50 years old railway organization. In operating this Tunnel, until the several problems came up based on stability and leaking water. The goal of study is evaluation of the various reinforcement systems for supporting of the tunnel. The optimal selection of the reinforcement system is examined using TOPSIS Fuzzy method in light of the looming and available uncertainties. Several factors such as; the tunnel span, maintenance, drainage, sealing, ventilation, cost and safety were based to choose the method and system of designing. Therefore, by identifying these parameters, an optimal reinforcement system was selected and introduced. Based on optimization system for analysis, it is revealed that the systematic rock bolts and shotcrete protection had a most appropriate result for these kind of tunnel in Iran.

• 동남아시아연구
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• 제21권3호
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• pp.105-138
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• 2011

The 11th Congress of the Vietnamese Communist Party(VCP) held in January 2011 was the forum to reconfirm the gradual reform. By analysing the documents submitted to the Congress, it can be realized that the VCP's reform policy reveals the compromise between conservative and progressive perspectives by "the Socialist-oriented Market Economy". The VCP proposes to proceed the balanced reform for the sustainable development by multi-sector economy to achieve the basis of the modern state by 2020 on the one hand and also urges to strive against "the peaceful evolution" to defend the socialist regime from abroad as well as within the party itself on the other hand. In personnel structure of the Central Committee and Politburo, this term of the Party still keeps the balance of the localities and sectors of the society. No big change was in the selection of top leaders, as almost of them were promoted slightly in the existing echelon of the Politburo. On the prospect of the reform process Vietnam will continue the reform as gradual as before.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.478-478
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• 2012

Recently, there are many researches in order to increase the deposition rate (D/R) and improve film uniformity and quality in the deposition of microcrystalline silicon thin film. These two factors are the most important issues in the fabrication of the thin film solar cell, and for the purpose of that, several process conditions, including the large area electrode (more than 1.1 X 1.3 (m2)), higher pressure (1 ~ 10 (Torr)), and very high frequency regime (VHF, 40 ~ 100 (MHz)), have been needed. But, in the case of large-area capacitively coupled discharges (CCP) driven at frequencies higher than the usual RF (13.56 (MHz)) frequency, the standing wave and skin effects should be the critical problems for obtaining the good plasma uniformity, and the ion damage on the thin film layer due to the high voltage between the substrate and the bulk plasma might cause the defects which degrade the film quality. In this study, we will propose the new concept of the large-area multi-electrode (a new multi-electrode concept for the large-area plasma source), which consists of a series of electrodes and grounds arranged by turns. The experimental results with this new electrode showed the processing performances of high D/R (1 ~ 2 (nm/sec)), controllable crystallinity (~70% and controllable), and good uniformity (less than 10%) at the conditions of the relatively high frequency of 40 MHz in the large-area electrode of 280 X 540 mm2. And, we also observed the SEM images of the deposited thin film at the conditions of peeling, normal microcrystalline, and powder formation, and discussed the mechanisms of the crystal formation and voids generation in the film in order to try the enhancement of the film quality compared to the cases of normal VHF capacitive discharges. Also, we will discuss the relation between the processing parameters (including gap length between electrode and substrate, operating pressure) and the processing results (D/R and crystallinity) with the process condition map for ${\mu}c$-Si:H formation at a fixed input power and gas flow rate. Finally, we will discuss the potential of the multi-electrode of the 3.5G-class large-area plasma processing (650 X 550 (mm2) to the possibility of the expansion of the new electrode concept to 8G class large-area plasma processing and the additional issues in order to improve the process efficiency.

• 원예과학기술지
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• 제32권4호
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• pp.473-483
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• 2014

In this work, the effects of shade combination, shade height and wind regime on greenhouse climate were quantified. A two-dimensional (2-D) computational fluid dynamics (CFD) model was developed based on an 11-span plastic greenhouse in eastern China for wind almost normal to the greenhouse orientation. The model was first validated with air temperature profiles measured in a compartmentalized greenhouse cultivated with mature lettuce (Lactuca sativa L., 'Yang Shan'). Next, the model was employed to investigate the effect of shade combinations on greenhouse microclimate patterns. Simulations showed similar airflow patterns in the greenhouse under different shade combinations. The temperature pattern was a consequence of convection and radiation transfer and was not significantly influenced by shade combination. The use of shade screens reduced air velocity by $0.02-0.20m{\cdot}s^{-1}$, lowered air temperature by $0.2-0.8^{\circ}C$ and raised the humidity level by 0.9-2.0% in the greenhouse. Moreover, it improved the interior climate homogeneity. The assessment of shade performance revealed that the external shade had good cooling and homogeneity performance and thus can be recommended. Furthermore, the effects of external shade height and wind regime on greenhouse climate parameters showed that external shade screens are suitable for installation within 1 m above roof level. They also demonstrated that, under external shade conditions, greenhouse temperature was reduced relative to unshaded conditions by $1.3^{\circ}C$ under a wind speed of $0.5m{\cdot}s^{-1}$, whereas it was reduced by merely $0.5^{\circ}C$ under a wind speed of $2.0m{\cdot}s^{-1}$. Therefore, external shading is more useful during periods of low wind speed.

• 한국수자원학회논문집
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• 제41권7호
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• pp.711-723
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• 2008

본 연구에서는 수문변화 지표법을 적용하여 11개 주요 다목적댐의 월 유량 크기, 연 최소.최대유량 크기와 지속기간, 고.저맥파 빈도와 주기, 수문곡선 변화 비율과 빈도를 분석하였다. 월 유량변화 분석 결과, 갈수기에 해당하는 1월부터 6월과 10월부터 12월까지는 유입량이 $6.38m^3/sec{\sim}39.84m^3/sec$이었으나, 방류량은 $20.36m^3/sec{\sim}49.43m^3/sec$로 $1.84%{\sim}200.98%$가 증가하였다. 우기철인 7월부터 9월까지는 유입량이 $79.06m^3/sec{\sim}137.12m^3/sec$ 이었으나, 방류량은 $65.32m^3/sec{\sim}80.16m^3/sec$로 $18.19%{\sim}40.39%$가 감소하였다. 연 최소.최대 유량변화 분석 결과는 1일 최소유량이 $82.86%{\sim}2,950%$가 증가하였으며, 연 최소 및 최대 유량변화는 1일 최소유량은 $82.86%{\sim}2,950%$가 증가하였으나, 1일 최대유량은 $34.78%{\sim}83.96%$가 감소하였다. 고.저맥파의 빈도와 주기의 분석 결과, 저맥파의 발생 횟수는 댐 조절후 $29.67%{\sim}99.07%$가 감소하였으며, 고맥파의 발생횟수도 $4.6%{\sim}92.35%$가 감소하였다. 수문곡선 변화 비율과 빈도의 분석 결과 상승률은 $15.84%{\sim}79.31%$가 감소하였으며, 하강율은 $1.97%{\sim}107.10%$가 감소하였다. 유량변화정도 분석 결과는 1일 최소유량은 $0.60{\sim}2.67$ 증가하였으며, 1일 최대 유량은 $0.50{\sim}1.00$으로 감소하였다.

• 기술혁신연구
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• 제20권2호
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• pp.161-187
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• 2012

상대적으로 비싼 에너지비용이 소요되는 신재생에너지를 사업화하기 위해서는 혁신적인 기술진보가 필수적이다. 신재생에너지 기술은 타 기술에 비해 충분한 실증-보급의 검증과정을 거치는 Long term High Risk의 특성이 있다. 본 연구는 전략적 니치 관리(SNM, Strategic Niche Management) 개념을 적용하여 정부의 신재생에너지 R&D를 단기 성과지향에서 중장기적 성장으로, 에너지시스템의 효율화 중심에서 사회시스템과의 상호교류 중심으로 전환하는 정책실행적 모델을 제안하고자 한다. 이를 위해 다층적 관점(MLP, Multi-Level Perspective)을 분석틀로 하여 태양광 기술개발과제가 니치단계에서 사업화 단계로 성장하는 과정을 고찰하였다. 분석결과 박막실리콘과 CIGS의 급속한 발전의 배경에는 개발주체가 과거 메모리 반도체의 NAND와 NOR 간 경쟁에서 사전적 학습효과가 있었다. 이를 통해 니치기술 중 경쟁기술이 존재할수록 학습효과는 더욱 배가됨을 확인할 수 있었다. 또한 산업계를 중심으로 학계와 출연연구소가 공동연구를 추진할 때 사업화로 진행되는 가능성이 높았다. 따라서 정부 연구개발의 사업화를 촉진하기 위해서는 과제기획 단계에서 지원대상 발굴시 기존 시장을 확보하고 있는 산업군에서 얻을 수 있는 경험(실패 또는 성공), Network 형성 단계 등의 지식흐름을 검토할 필요가 있음을 제안한다. 본 연구가 구성한 전략적 니치 관리(Strategic Niche Management)의 개념틀은 메타적 차원이며 향후, 실증을 위한 검증과 추가적 정합성 분석으로 구체화 할 것이다.

• 한국조경학회지
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• 제43권4호
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• pp.1-14
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• 2015

서구에서는 인체의 오감 중 시각을 가장 중요하게 여기고 있으나, 시각중심주의적 사고는 많은 문제점을 내포하고 있다. 시각중심주의는 주체를 특권화하며, 다른 감각들과의 상호작용을 억제하면서 세계에 대한 경험을 시각 영역에 한정한다. 그러나 경험은 다양한 양식의 '만짐'으로써 이해될 수 있으며, 감촉성과 관련이 있다. 현대조경에서는 시각중심주의에 반하여 신체의 다감각적 측면에 관심이 고조되면서 외부공간에서 신체의 개입이 중요한 이슈가 되었다. 본 연구는 주체의 능동적 체험을 촉발하는 촉지적 지각 체제에 대한 가능성을 탐구한다. 촉지적 지각은 주체의 능동적 체험을 이끄는 촉매적 역할을 수행하며, 이러한 촉지적 지각을 통해 주체는 장소성을 체험한다. 촉지적 지각은 다양한 감각의 동시성과 상호작용을 통하여 촉각을 통해 알고 있던 것을 드러냄으로써 능동적인 참여를 이끌어낸다. 촉지적 지각 체제는 다양한 분야에서 연구되었으나, 조경 분야에서는 연구가 이루어지지 않았다. 이에 본 연구는 모더니즘 이전에 나타난 조경에 한하여 촉지적 지각의 양상에 관하여 논하고자 한다. 촉지적 지각에 대한 이론적 배경에서는 선행연구 및 문헌 고찰을 통하여 촉지적 지각의 개념을 명확히 하고, 촉지적 지각의 특성을 도출한 연후, 시각중심주의 체제의 문제점과 촉지적 지각의 필요성을 논하다. 촉지적 지각의 역사적 전개 과정에서는 시각 체제의 변화 과정을 시대순으로 살펴보며, 시각중심적 사고와 반-시각중심적 사고가 각 시대의 건축과 조경에 어떻게 투영되었는지를 문헌 및 사례를 통하여 고찰한다. 이후, 시대적 변화 과정에서 시각 체제가 조경 분야에 미친 영향을 고찰한다.

• Tribology and Lubricants
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• 제31권1호
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• pp.21-27
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• 2015

We carry out experiments to characterize textured bearing steel with varying hole density and depth. Textured surface is believed to reduce the friction coefficient, and improve performance and wearing caused by third-body contact. We employ three lubrication regime conditions based on the Stribeck curve: boundary lubrication, mixed lubrication, and hydrodynamic lubrication. Ultrasonic machining is an untraditional machining method wherein abrasive grit particles are used. The hammering process on the work piece surface by abrasive provides the desired form. In this study, we create multi-holes on the bearing steel surface for texturing purposes. Holes are formed by an ultrasonic machine with a diameter of 0.534 mm and a depth of about 2-4 mm, and they are distributed on the contact surface with a density between 1.37-2.23%. The hole density over the surface area is an important factor affecting the friction. We test nine types of textured specimens using four times replication and compare them with the untextured specimen using graphs, as well as photographs taken using a scanning electron microscope. We use Analyzes variant in this experiment to find the correlation between each pair of treatments. Finally, we report the effect of hole density and depth on the friction coefficient.

• 항공우주정책ㆍ법학회지
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• 제7권
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• pp.151-175
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• 1995

In recent years, questions have arisen under several forms with respect to the need for adapting present legal order established under the Chicago Convention and relevant customary rules into newly developed environment surrounding the international air transport industry. Major feature of such trends included in opinions for modification of the present legal order might be defined as more liberalistic approach to this industry. In this respect, many scholars and lawyers in this field agree with a view that a theoretical tie between an aircraft/air liners and a register - State lies in political and strategical concern of the State so that each aircraft/air liners has been attributed a single nationality. In the context of such concern, each aircraft/air liners has been related with each register-State in the form of "genuine connection". However, present and near future development of air transport industry and its world - wide market requires some modification of such single nationality regime. Taking into account such circumstances, States as creator of present legal order are in the process of establishing new legal order where air liners with multi - nationality are capable of satisfying to such needs. As adopting a series of liberalization package for air transport industry in european continent, European Union adopts a concept of "community air carrier", by which an air space of each member State is open to each other, especially through the grant of cabotage right. A serious concern may arise in such grant because the Article 7 of the Chicago Convention prohibits such grant on an exclusive basis. While many theoretical opinions have been put forward concerning the interpretation of that article, a case of European Union shall be a good test of the range of its application. It is anticipated that future development around this issue shaH furnish us a major feature of the liberalization of international air transportation and an adaptation process of present legal order.