• Title/Summary/Keyword: 유동매체

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Analysis for Aerodynamic Resistance of Chrysanthemum Canopy through Wind Tunnel Test (풍동실험을 통한 국화군락의 공기유동 저항 분석)

  • Yu, In-Ho;Yun, Nam-Kyu;Cho, Myeong-Whan;Lee, In-Bok
    • Journal of Bio-Environment Control
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    • v.17 no.2
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    • pp.83-89
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    • 2008
  • A wind tunnel test was conducted at Protected Horticulture Experiment Station of National Horticultural Research Institute in Busan to find the aerodynamic resistance and quadratic resistance coefficient of chrysanthemum in greenhouse. The internal plants of the CFD model has been designed as a porous media because of the complexity of its physical shapes. Then the aerodynamic resistance value should be input for analyzing CFD model that crop is considered while the value varies by crops. In this study, the aerodynamic resistance value of chrysanthemum canopy was preliminarily found through wind tunnel test. The static pressure at windward increased as wind velocity and planting density increased. The static pressure at leeward decreased as wind velocity increased but was not significantly affected by planting density. The difference of static pressure between windward and leeward increased as wind velocity and planting density increased. The aerodynamic resistance value of chrysanthemum canopy was found to be 0.22 which will be used later as the input data of Fluent CFD model. When the planting distances were $9{\times}9\;cm$, $11{\times}11\;cm$, and $13{\times}13\;cm$, the quadratic resistance coefficients of porous media were found to be 2.22, 1.81, and 1.07, respectively. These values will be used later as the input data of CFX CFD model.

From Multivalent Mediality to Cross-Sector Synergy: The Archetypal Function of Dramatized Blockbuster Ballad Music Videos in Hallyu Entertainment (한류 컨텐츠의 원형으로서의 서사적 블록버스터 발라드 뮤직 비디오 고찰)

  • Shin, Haerin
    • Review of Culture and Economy
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    • v.20 no.1
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    • pp.21-50
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    • 2017
  • The rise of Hallyu (Korean Wave) has generated a treasury of historiographic and cultural inquiries into the phenomenal success of South Korea's media entertainment industry. Whereas the majority of such studies focus on TV dramas and popular music, there is a medium, or rather a hybrid sub-genre within the medium category of short films, that must be reexamined and thus appreciated as the archetypal predecessor of popular Hallyu contents: music videos. The rapidly changing social, political, and economic climate in the mid- to late 1990s called for content that would grasp the attention of a younger, increasingly mobile population with diversified interests and routines that no longer guaranteed fixed-time viewership. Meanwhile, the advent of cable TV channels and high-speed internet service ensured greater temporal and infrastructural accessibility. The media entertainment industry's response to the new opportunities and challenges arising from these sudden growths in the scale, range, connectivity, and mobility of consumer demographics was synergetic cross-sector collaboration in the form of dramatized blockbuster music videos, which combined two popular and lucrative genres: trendy dramas and ballad music. In this essay, by relocating Hallyu's archetypal medium/genre, I claim that increasing upward and sideways mobility across sectors not only inspired new production but also reconfigured the very concept, form, and impact of media-driven cultural imaginary in South Korea.

An Experimental Study on the Energy Separation in the Ratio of Nozzle Area of a tow Pressure Vortex Tube (저압용 보텍스튜브의 노즐면적비에 따른 에너지 분리특성에 관한 실험적 연구)

  • 오동진;최정원
    • Journal of Energy Engineering
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    • v.13 no.1
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    • pp.34-39
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    • 2004
  • The process of energy separation in a low pressure vortex tube with compressed air as a working medium is studied in detail. Experimental data of the temperature of the cold and hot air leaving the vortex tube are presented. The variation of the maximum wall temperature along the inner surface of a vortex tube and the temperature distribution in a vortex tube provide useful information about the location of the stagnation point of the flow field at the axis of the vortex tube Analysis of the results enabled to find the optimum ratio of nozzle area and the optimum shape of an orifice. From this optimum geometric setup of a low pressure and big vortex tube the effectiveness of energy separation was better than a high pressure and small vortex tube.

Dispersion of Silicon Nitride Particles and Sintering Additives of AlN and Nd$_2$O$_3$ in Nonaqueous Suspending Media (비수계분산매체에서 질화규소와 소결첨가제 AlN 및 Nd$_2$O$_3$의 분산)

  • 김재원;백운규;윤경진
    • Journal of the Korean Ceramic Society
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    • v.36 no.2
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    • pp.210-219
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    • 1999
  • The fundamental dispersion property of Si2N4 and a combination of AlN and Nd2O3 as sintering additives in a variety of organic solvents such as alcohols, hydrocarbons, ketones, and ethers was investigated. The stabilization mechanism and interaction between organic functional groups of the various organic additives were studied to clarify the dispersibility of the ceramic particles in the nonaqueous suspending medium. characterization of the suspensions was based mainly on electrokinetic sonic amplitude(ESA) measurements and the flow curves obtained from the rheological studies as well as estimated Hamaker constants. It was found that the contribution of electrostatic repulsive forces to the Si3N4, AlN and Nd2O3 stabilization in organic media is appreciably greater than anticipated and is dependent on the physicochemical properties of organic solvents.

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Characterization of a TSV sputtering equipment by numerical modeling (수치 모델을 이용한 TSV 스퍼터링 장비의 특성 해석)

  • Ju, Jeong-Hun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2018.06a
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    • pp.46-46
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    • 2018
  • 메모리 소자의 수요가 데스크톱 컴퓨터의 정체와 모바일 기기의 폭발적인 증가로 NAND flash 메모리의 고집적화로 이어져서 3차원 집적 기술의 고도화가 중요한 요소가 되고 있다. 1 mm 정도의 얇은 웨이퍼 상에 만들어지는 메모리 소자는 실제 두께는 몇 마이크로미터 되지 않는다. 수직방향으로 여러 장의 웨이퍼를 연결하면 폭 방향으로 이미 거의 한계에 도달해있는 크기 축소(shrinking) 기술에 의지 하지 않고서도 메모리 소자의 용량을 증대 시킬 수 있다. CPU, AP등의 논리 연산 소자의 경우에는 발열 문제로 3D stacking 기술의 구현이 쉽지 않지만 메모리 소자의 경우에는 저 전력화를 통해서 실용화가 시작되었다. 스마트폰, 휴대용 보조 저장 매체(USB memory, SSD)등에 수 십 GB의 용량이 보편적인 현재, FEOL, BEOL 기술을 모두 가지고 있는 국내의 반도체 소자 업체들은 자연스럽게 TSV 기술과 이에 필요한 장비의 개발에 관심을 가지게 되었다. 특히 이 중 TSV용 스퍼터링 장치는 transistor의 main contact 공정에 전 세계 시장의 90% 이상을 점유하고 있는 글로벌 업체의 경우에도 완전히 만족스러운 장비를 공급하지는 못하고 있는 상태여서 연구 개발의 적절한 시기이다. 기본 개념은 일반적인 마그네트론 스퍼터링이 중성 입자를 타겟 표면에서 발생시키는데 이를 다시 추가적인 전력 공급으로 전자 - 중성 충돌로 인한 이온화 과정을 추가하고 여기서 발생된 타겟 이온들을 웨이퍼의 표면에 최대한 수직 방향으로 입사시키려는 노력이 핵심이다. 본 발표에서는 고전력 이온화 스퍼터링 시스템의 자기장 해석, 냉각 효율 해석, 멀티 모듈 회전 자석 음극에 대한 동역학적 분석 결과를 발표한다. 그림1에는 이중 회전 모듈에 대한 다물체 동역학 해석을 Adams s/w package로 해석하기 위하여 작성한 모델이고 그림2는 180도 회전한 서브 모듈의 위상이 음극 냉각에 미치는 효과를 CFD-ACE+로 유동 해석한 결과를 나타내고 있다.

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Development of a New Heat Exchanger for the Super Cooling (HESC) to Enhance the Performance of the Heat Pump System for the Living Space by the Natural Energy (자연에너지를 이용한 생활공간 냉난방용 열펌프의 성능향상을 위한 과냉 촉진 신개념 열교환기(HESC) 개발)

  • Song, Heon
    • Journal of the Korean Solar Energy Society
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    • v.31 no.6
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    • pp.40-48
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    • 2011
  • 과냉 촉진을 위한 새로운 열교환기(HESC)가 생활공간의 냉난방을 위한 공기-물 열펌프의 성능계수 향상을 위해 본 연구에서 개발되었으며 그 효과를 실험적으로 분석하였다. 이 열교환기(HESC)는 여러 단계의 셀과 튜브로 구성되어 있으며, 열펌프 시스템의 응축기와 증발기 사이에 장착되었다. 실험 조건으로, 외기온은 $7^{\circ}C$에서 $-17^{\circ}C$, 입구 물 온도는 $7{\sim}10^{\circ}C$ 그리고 제 2열전달매체로서 물의 질량 유동율은 시간당 100에서 $300{\ell}$로 변화를 주었다. 본 실험에서 이 열교환기가 장착된 열펌프의 압축기에서의 냉매 입 출구 사이의 온도 차이는 열교환기가 장착되지 않은 열펌프보다 $15^{\circ}C$ 높았다. 이에 따라 이 열교환기가 장착된 열펌프 시스템은 외기온 $-10^{\circ}C$에서 COP가 0.8 증가하였다. 따라서 이 공기-물 열펌프 시스템은 최근 한국에서 실용화되고 있는 고비용이 요구되는 지열 열펌프 시스템을 대체하여 생활공간을 위한 냉난방 시스템으로서 중요한 역할을 할 수 있을 것으로 사료된다.

A Study on Digital Film Acting - Focus on Pratical Use of Stanislavsky's Circle of Attention (디지털영상연기방법 고찰 - 스타니슬랍스키의 주의집중의 범위를 중심으로)

  • Yoo, Dong-Hyuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.3
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    • pp.749-753
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    • 2014
  • The purpose of this study analyzes the basic elements of film acting based on Stanislavsky Circles of Attention. This research also demonstrates the basic elements on how to become a good film actor. I attempt to interpret Stanislavsky Circles of Attention, in order to adapt the size of camera shots and the location of microphones. This Circles of Attention is an effective method utilized for actors to help them understand and be absorbed in the work of art both in film and stage. It is useful for building a character in realism drama as well as in film. I believe Stanislavsky Circles of Attention is certainly the most advanced acting style in film because it proposes the importance of physical action for actors.

Netart Implementation Using Visualization of Image Color Data (이미지 컬러 데이터의 시각화를 통한 넷아트 구현)

  • Kim, Byeung-Won;Kim, Jong-Seo;Kwak, Hoon-Sung
    • The Journal of the Korea Contents Association
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    • v.9 no.6
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    • pp.53-61
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    • 2009
  • Among the properties of new media art works, interaction with audience has now become a big issue, and its influence to general arts, in particular media art, is being stressed more and more. Under the this influence, various experimental works using digital media are being produced and having a try to combination of art and multimedia technology on the network. This paper analyses studies about netart and suggests visualization expression of color data to be interactive between users and art works. The work is to make formative elements based fluid shapes on the analysis of color data extracted from images. This is a new experiment in picturesque expression of data and aesthetic visualization of data.

Design Scheme to Develop Integrated Remediation Technology: Case Study of Integration of Soil Flushing and Pneumatic Fracturing for Metal Contaminated Soil (복합복원기술 개발을 위한 설계안 : 중금속 오염토양을 위한 토양세척과 토양파쇄의 통합 사례 연구)

  • Chung, Doug-Young;Yang, Jae-E.
    • Korean Journal of Soil Science and Fertilizer
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    • v.39 no.1
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    • pp.29-37
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    • 2006
  • In remediation of the contaminated soil, it requires to select at least more than two remediation technologies depending on the fate and transport phenomena through complicated reactions in soil matrix. Therefore, methodologies related to develop the integrated remediation technology were reviewed for agricultural soils contaminated with heavy metals. Pneumatic fracturing is necessary to implement deficiency because soil washing is not effective to remove heavy metals in the subsurface soil. But it needs to evaluate the characteristics such as essential data and factors of designated technology in order to effectively apply them in the site. In the remediation site, the important soil physical and chemical factors to be considered are hydrology, porosity, soil texture and structure, types and concentrations of the contaminants, and fate and its transport properties. However, the integrated technology can be restrictive by advective flux in the area which remediation is highly effective although both soil washing and pneumatic fracturing were applied simultaneously in the site. Therefore, we need to understand flow pathways of the target contaminants in the subsurface soils, that includes kinetic desorption and flux, predictive simulation modeling, and complicated reaction in heterogenous soil.

A Study on the Thermal Flow of Waste Heat Recovery Unit (WHRU) for Ship's Organic Rankine Cycle Power Generation System using CFD Method (CFD를 활용한 선박고온도차발전용 WHRU의 열유동 해석에 관한 연구)

  • Whang, Dae-jung;Park, Sang-kyun;Jee, Jae-hoon;Bang, Eun-shin;Oh, Cheol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.5
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    • pp.647-655
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    • 2021
  • The IMO (International Maritime Organization) is discussing the improvement of energy ef iciency of ships in order to reduce greenhouse gas emissions from ships. Currently, by applying an ORC power generation system using waste heat generated from ships, high energy conversion efficiency can be expected from ships. This technology uses an organic medium based on Freon or hydrocarbons as the working fluid, which evaporates at a lower temperature range than water. Through this, it is possible to generate steam (gas) and generate power at a low and low temperature relatively. In this study, the analysis of heat flow between the refrigerant and waste heat in the ORC power generation system, which is an organic Rankine cycle, is analyzed using 3D simulation techniques to determine the temperature change, velocity change, pressure change, and mass change of the fluid flowing of the WHRU (Waste Heat Recovery Unit) inside and the outside the structure. The purpose of this study is to analyze how the mass change affects the structure, and this study analyzed the heat transfer of the heat exchanger from the refrigerant and the exhaust gas of the ship's main engine in the ORC power generation system using this technique.