• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.427-429
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• 1993

In this paper, GIS (Geographical Information System) for KODAS (Korea Distribution Automation System) will be presented. It has been developed to display the status of distribution power line facilities with background geographical map information (eg. address, street, railways and building) and provides various menu screen that can be handled easily. We will discuss computer system I/F between Host computer and GIS, DB structure for GIS and It's functions.

• 한국콘텐츠학회논문지
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• 제14권5호
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• pp.30-43
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• 2014

본 연구는 최근 증가하고 있는 온라인 콘텐츠 유통 사업자들의 비즈니스 모델을 탐색하기 위하여 최근 빠르게 성장하고 있는 미국의 넷플릭스와 훌루를 분석하였다. STOF 분석 틀을 도입, 두 사업자의 외부 환경, 서비스 영역, 조직 영역, 재무 영역을 분석하여 본 결과, 초기 비즈니스 모델은 분명하게 차별화되고 있는 것으로 나타났다. 넷플릭스는 저렴한 비용으로 온, 오프라인 통합 서비스를 제공하고 콘텐츠 추천 서비스를 제공함으로써 성장할 수 있었던 반면, 훌루는 유료 방송과의 경쟁에 직면하여 수용자 락인을 목적으로 무료 서비스를 시작함으로써 광고 없이 TV 콘텐츠를 시청하고자 하는 수용자를 끌어들일 수 있었다. 그러나 시간이 지날수록 두 사업자의 비즈니스 모델은 동질화되어 가는 것으로 나타났다. 특히 시장의 경쟁 심화와 서비스 영역의 동질화가 이에 영향을 미친 것으로 분석된다. 또한 경쟁 심화라는 외부 환경적 요인은 콘텐츠 소싱 비용의 증가 및 수익률 감소로 직결되고 있는 것으로 나타났다. 이는 콘텐츠 및 수용자 가치를 창출할 수 있는 차별적인 비즈니스 모델의 구축이 필요함을 시사한다.

• 한국콘텐츠학회논문지
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• 제15권9호
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• pp.509-526
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• 2015

본 연구에서는 N-스크린 시대의 미국, 영국, 일본의 유력 신문사의 디지털 콘텐츠 유료화 전략을 비교, 분석했다. 분석의 틀로는 디지털 콘텐츠의 유료화 시점, 시장 세분화 여부, 4P 마케팅 믹스 전략이 활용됐다. 해외 주요 신문사들의 디지털 콘텐츠 유료화 전략은 2000년을 전후로 시작된 후, 2000년 초중반 캐즘을 겪었고 2010년 모바일 기기의 확산으로 본격화된 것으로 나타났다. 분석 대상 신문사 대부분은 상품 측면에서 시장을 세분화하는 모습을 보이진 않았다. 4P 전략의 관점에서 상품 전략의 경우, e-paper와 디지털 콘텐츠를 축으로 프리미엄 서비스가 부가되는 방식으로 전개되고 있었다. 가격 전략은 연성 체계와 혼합 체계가 주로 활용됐다. 유통전략은 디지털 콘텐츠에 대한 세분화 여부에 따라 대별됐다. 디지털 콘텐츠의 유통경로는 '디지털'로 묶어 하나의 대상으로 간주하면 단일 요금제, 그렇지 않고 각각의 단말기마다 세분화 한 경우에는 복합 요금제가 선택됐다. 판촉 전략에서는 종이신문과의 번들링 전략이 주로 채택되는 가운데, 시범 이용을 두고 분석 결과가 서구(미국과 영국)와 일본 간 상이하게 나타났다.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2621-2627
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• 2023

In Experimental Advanced Superconducting Tokamak (EAST) experiments, to achieve long pulse and high-power ICRH system operation, a new kind of ICRH antenna has been designed. One of the most critical factors in limiting the operation of long pulse and high power is the intense heat load in the front face of the ICRH antenna, especially the Faraday Screen (FS). Therefore, the cooling channels of FS need to be designed. According to thermal-hydraulic analysis, the FS tubes are divided into several groups to achieve more excellent water cooling capability. The number of series and parallel tubes in one group is chosen as six. This antenna went into service in the spring of 2021, and it is delightful that the temperature distribution of the FS tube is below 400 ℃ in 14.5 s and 1.8 MW ICRH system operation. However, the active water-cooling design was not carried out on the upper and lower plates of FS, which led to severe ablations on that region under long pulse and high power operation, and the temperature is up to 800. Therefore, the upper and lower side plates of the FS were designed with water cooling based on thermal-hydraulic analysis. During the 2022 winter experiments, the temperature of ICRH antenna FS was lower than 400 in the pulse of 200s and the power of 1 MW operation.

• 한국컴퓨터정보학회논문지
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• 제12권3호
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• pp.235-241
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• 2007

국내농산물에 대한 원산지 확인 및 각 프로세스별 정보의 관리는 수입개방여파와 더불어 다양한 소비자계층의 다양한 기호를 충족시켜 줄 수 있는 안심하고 질 좋은 제품을 최종 소비자에게 전달하기 위한 시스템 구축에 많은 노력을 하고 있다. 이는 생산 농가에서 가공, 처리, 판매 단계에서 발생하는 많은 정보들이 원천데이터의 생성에서부터 판매단계까지의 정보가 잘 관리되고 있지 않다는 현실이 식품의 안전을 확인하는데 문제를 발생시키는바 생산이력정보시스템의 구축의 필요성을 야기하고 있다. 따라서 본 논문에서는 축산물의 생산에서 가공, 처리, 유통, 판매 과정에서 발생하는 각 프로세스별 관련 정보를 관리 처리할 수 있는 생산이력시스템(Traceability System)에 대한 국내외 사례와 일반 생산농가를 대상으로 한 시스템 구축과 도입방안에 대해 살펴보았다.

• 센서학회지
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• 제17권6호
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• pp.418-424
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• 2008

The PZT based piezoelectric thick films prepared by screen printing method have been mainly used as a functional material for MEMS applications due to their compatibility of MEMS process. However the screen printed thick films generally reveal poor electrical and mechanical properties because of their porous microstructure. To improve microstructure we mixed attrition milled powder with ball milled powder of 0.01Pb$(Mg_{1/2}W_{1/2})O_3$-0.41Pb$(Ni_{1/3}Nb_{2/3})O_3$-$0.35PbTiO_3$-$0.23PbZrO_3$+0.1 wt% ${Y_2}{O_3}$+1.5 wt% ZnO composition. By mixing 25 % of attrition milled powder and 75 % of ball milled powder, the broadest particle size distribution was obtained, leading to a dense thick film with crack-free microstructure and improved dielectric properties. The X-ray diffraction analysis revealed that the film was in wellcrystallized perovskite phase. The remanent polarization was increased from $13.7{\mu}C/cm^2$ to $23.3{\mu}C/cm^2$ at the addition of 25 % attrition milled powder.

• Journal of Mechanical Science and Technology
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• 제14권1호
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• pp.121-129
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• 2000

The thermal performance of a flat evaporator for capillary pumped loop (CPL) applications was investigated. Two to four layers of coarse wire screen wicks were placed onto the heated surface to provide irregular passages for vapor flow. The evaporator and condenser were separated by a distance of 1.2 m and connected by individual liquid and vapor lines. The wall material was copper and the working fluid was ethanol. The experimental facility utilized a combination of capillary and gravitational forces for liquid return, and distribution over the evaporator surface. The tubing used for vapor and liquid lines was 9.35 mm or less in diameter and heat was removed from the condenser by convection of air. A heat flux of up to $4.9{\times}10^4$ $W/m^2$ was applied to a flat evaporator having dimensions of 100 mm by 200 mm, 20 mm thick. The thermal resistance of the system as well as the temperature characteristics of the system was investigated as the evaporator heat flux and the condenser cooling capacity varied. The performance of the evaporator and effect of condenser cooling capacity were analyzed and discussed.

• 한국농공학회논문집
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• 제55권6호
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• pp.31-35
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• 2013

This study was carried out to present the pressure drop for various wind speeds through nine types of screens used in horticultural facilities. The screens have been widely used to prevent harmful insects from being entered into agricultural facilities, to reduce strong wind and to shade a light as well. Whatever the usage of the screens was, it was necessary to have good knowledge of how much the screen caused a pressure drop for wind speeds when analyzing both the inner thermal-flow distribution in the facility and the effect of reducing wind speed by using CFD. Furthermore, as for wind screens, the pressure drop for wind speeds was needed as a design load in evaluating the structural stability of the structures supporting the screens. Therefore, the pressure drop through the screens for wind speeds of 5~30 $m{\cdot}s^{-1}$ at about 5 $m{\cdot}s^{-1}$ interval and inflow angles of $0{\sim}45^{\circ}$ at an interval of $15^{\circ}$ was respectively measured in a subsonic wind tunnel. The relation of the pressure drop for various screens was well fitted as a secondorder polynomial expression.

• 설비공학논문집
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• 제20권12호
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• pp.789-794
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• 2008

Recently, much attention has been paid in the field of defrosting because clear windshield in vehicle without effecting the thermal comfort is realized essentially. Then in winter, defrosting performance is one of the important factors in vehicle design to make certain driver's view. In this study, the velocity profile, temperature distribution and frost melting pattern on the windshield screen have been predicted in three dimensional geometry of an automobile interior. Numerical analyses predict a detailed description of fluid flow and temperature patterns on the inside windshield screen, utilizing the flow through defroster nozzle. Numerical prediction established a good defrosting performance with the standard distance ratio and the defroster nozzle angle ranging from $30^{\circ}$ to $40^{\circ}$, which satisfy the condition of National Highway Traffic Safety Administration (NHTSA) completely.

• 방송공학회논문지
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• 제9권2호
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• pp.119-130
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• 2004

We have developed a prototype super-high-definition (SHD) digital cinema distribution system that can store, transmit, and display eight-million-pixel motion pictures that have the image quality of a 35-mm film movie. The system contains a movie server, a real-time decoder, and an SHB projector. Using a Gigabit Ethernet link and TCP/IP, the server transmits JPEG2000 compressed motion picture data streams to the decoder at transmission speeds as high as 300 Mbps. The received data streams are decompressed by the decoder, and then projected onto a screen via the projector. By using an enlarged TCP window, multiple TCP streams, and a shaping function to control the data transmission quantity, we achieved real-time streaming of SHD movie data at about 300 Mbps between Chicago and Los Angeles, a distance of more than 3000 km. We also improved the decoder performance to show movies with Image qualities of 450 Mbps or higher. Since UDP is more suitable than TCP for fast long-distance streaming, we have developed an SHD digital cinema UDP relay system, in which UDP is used for transmission over a fast long-distance network. By using four pairs of server-side-proxy and decoder-side-proxy, 450-Mbps movie data streams could be transmitted.