• 제목/요약/키워드: 초공동

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카메라 및 관련 제품 특소세 폐지 시급

  • 한국광학기기협회
    • The Optical Journal
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    • v.12 no.6 s.70
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    • pp.15-16
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    • 2000
  • 올 초부터 사진 관련 단체와 업계가 하나가 되어 진행해 온 '카메라 특소세 폐지'를 위한 노력에도 불구하고, 올 개정은 무산됐다. 이제 내년 국회 개원을 기다리는 수밖에 없다. 비록 성사되지는 못한 데 안타까움은 남지만, 그래도 이번 활동은 모처럼 공동 목표 아래 관련 종사자들이 모여 하나의 목소리를 내는 계기가 됐다는 데서 의미를 찾을 수 있을 것이다. 모쪼록 '1회성 목소리 높이기'에 그치지 말고 체계적인 준비를 해가 내년에 좋은 소식을 들을 수 있

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Characteristics of Planting Design according to Parking Lots Type in Multi-family Housing Complex (공동주택단지의 주차장 유형에 따른 식재특성)

  • Hong, Seong-Rae;Jeong, Dae-Young;Shim, Sang-Ryul
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.1
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    • pp.43-49
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    • 2009
  • The number of registered vehicles increased to one million in 1985 and ten million in 1997, and the parking lots in multi-family housing complex that had been mainly constructed on the ground level began to be constructed in underground levels. Therefore, planting design in such complex were greatly changed. This study classifies the parking lots in multi-family housing complexes located in Cheongju into three categories: above-ground, mixture of above-ground and underground, and underground. The characteristics of planting design in each were then analyzed. The rate of parking per family increased by two or more in the type of mixture when compared to in the type of above-ground. As underground parking lots became dominant, the rate of parking per family increased to one car or more. The green area ratio did not change considerably when above-ground parking was combined with underground parking, but the green area per total floor space was reduced, which indicates the quality of green area became lower. Most of the parking lots in multi-family housing complexes since 2000 have been constructed underground, and the green area became larger. As for the species of trees used in planting design, trees that are vulnerable to damage by blight and harmful insects and may be repugnant have been reduced and replaced by trees whose shapes are beautiful and whose flowers and fruits can be appreciated, such as Chionanthus retusa, Malus floribunda, Styrax japonicus, Prunus mume, Lagerstroemia indica. Pine trees are variously planted with diversified standards, and, in particular, tall pine trees are being utilized as focal points. Herbaceous flowers began to be planted in underground parking lots constructed since 2000, and they are expected to be planted even more due to the appreciation of their flowers and their splendid appearance.

Induction of Demyelination of Neuronal cells by Sindbis Virus (Sindbis Virus에 의한 뉴런세포의 탈수초의 유도)

  • Sa, Young-Hee;Kim, Hyun Joo;Kweon, Tae Dong;Kim, Ji-Young;Lee, Bae Hwan;Hong, Seong-Karp
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.584-587
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    • 2018
  • Many viruses including mouse hepatitis virus, corona, measles, and sidbis viruses are known as causative virus of inducing demyelination which means destruction of myelination in nervous system of mice. The purpose of this study is to investigate processing of myelination by co-culture of Schwann cells and neuronal cells and demyelination induced by infection of sindbis virusin rat. Schwann cells and neuronal cells from dorsal root ganglion (DRG) in embryos (E16) of rat were cultured in vitro respectively. The purified neuronal cells with anti-mitotic agents and purified Schwann cells were co-cultured. After that, infection of sindbis virus into this myelinated co-culture system was performed. Myelination and demyelination process were observed using antibody of myelin basic protein meaning presence of myelination.We identified myelination and demyelination processing using antibody of peripheral myelin protein 22 (PMP 22) meaning presence of myelinated neuron. This study was supported by the Basic Research Program through the National Research Foundation (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2015R1C1A1A01053484 and 2017R1A2B3005753).

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Numerical Analysis of Supercavitating Flows of Two-Dimensional Simple Bodies (2차원 단순 물체의 초공동 유동에 대한 수치해석)

  • Lee, Hyun-Bae;Choi, Jung-Kyu;Kim, Hyoung-Tae
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.6
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    • pp.436-449
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    • 2013
  • In this paper, a numerical analysis is carried out to study the characteristics of supercavitating flows and the drag of relatively simple two-dimensional and axisymmetric bodies which can be used for supercavity generation device, cavitator, of a high-speed underwater vehicle. In order to investigate the suitability of numerical models, cavity flows around the hemispherical head form and two-dimensional wedge are calculated with combinations of three turbulence models(standard $k-{\epsilon}$, realizable $k-{\epsilon}$, Reynolds stress) and two cavitation models(Schnerr-Sauer, Zwart-Gerber-Belamri). From the results, it is confirmed that the calculated cavity flow is more affected by the turbulence model than the cavitation model. For the calculation of steady state cavity flows, the convergence in case of the realizable $k-{\epsilon}$ model is better than the other turbulence models. The numerical result of the Schnerr-Sauer cavitation model is changed less by turbulence model and more robust than the Zwart-Gerber-Belamri model. Thus the realizable $k-{\epsilon}$ turbulence model and the Schnerr-Sauer cavitation model are applied to calculate supercavitating flows around disks, two dimensional $10^{\circ}$ and $30^{\circ}$ wedges. In case of the disk, the cavitation number dependences of the cavity size and the drag coefficient predicted are similar to either experimental data or Reichardt's semi-empirical equations, but the drag coefficient is overestimated about 3% higher than the Reichardt's equation. In case of the wedges, the cavitation number dependences of the cavity size are similar to experimental data and Newman's linear theory, and the agreement of the cavity length predicted and Newman's linear theory becomes better as decreasing cavitation number. However, the drag coefficients of wedges agree more with experimental data than those of Newman's analytic solution. The cavitation number dependences of the drag coefficients of both the disk and the wedge appear linear and simple formula for estimating the drag of supercavitating disks and wedges are suggested. Consequently, the CFD scheme of this study can be applied for numerical analysis of supercavitating flows of the cavitator and the cavitator design.

Design of Supersonic Wind Tunnel for Analysis of Flow over a Backward Facing Step with Slot Injection (슬롯 분사가 있는 후향계단 유동장 분석을 위한 초음속풍동 설계)

  • Kim, Ick-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.363-367
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    • 2016
  • A test section of a supersonic wind tunnel was designed for the analysis of flow characteristics over a backward-facing step with Mach 1.0 slot injection in a supersonic flow of Mach 2.5. The cavity flow of a high-speed vehicle is very complex at supersonic speed, so it is necessary to do experiments using supersonic wind tunnels to verify numerical analysis methods. The previous 2D symmetrical nozzle was replaced with an asymmetrical nozzle. The inviscid nozzle contour was designed using Method of Characteristics (MOC), and the boundary layer thickness correction was reflected by experimental data from the wind tunnel. The results were compared with a CFD analysis. The PID control system was changed to be based on the change of tank pressure. This improved the control efficiency, and the run times of supersonic flow increased by about 1 second. The flow characteristics over a backward facing step with slot injection were visualized by a Schlieren device. This equipment will be used for an experimental study of the film cooling effectiveness over a cavity with various velocities, mass flows, and temperatures.

Infection of Semliki Forest Virus Induces Demyelination of Neuron (Semliki Forest Virus 감염은 뉴우런의 탈수초를 유발한다)

  • Kim, Hyun Joo;Sa, Young-Hee;Hong, Seong-Karp
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.6
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    • pp.1212-1217
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    • 2017
  • We constructed a population of myelinated cells with co-culture of neuronal cells and Schwann cells from DRG. Schwann cells and neuronal cells were isolated from dorsal root ganglion (DRG) in embryos of rat in vitro respectively. The cultured Schwann cells and cultured neuronal cells, respectively were co-cultured in a same plate. This procedure contains following four steps: first step of suspension of the embryonic dorsal root ganglion cells, second step of addition of anti-mitoticcocktail, third step of purification of dorsal root cells, and fourth step of addition of Schwann cells to dorsal root ganglion cells. These cells were performed accomplishment of myelination. This myelinated co-culture system was infected by Semliki forest virus and then induced demyelination processing in this myelinated co-culture. We identified myelination and demyelination processing using antibody of peripheral myelin protein 22 (PMP 22) meaning presence of myelinated neuron.

A Study on the External Wall Heating Temperature Distribution According to Opening Size in Building (건물의 개구부 크기에 따른 외벽 수열온도분포에 관한 연구)

  • Jung, Ui-In;Hong, Sang-Hun;Kim, Bong-Joo
    • Journal of the Korea Institute of Building Construction
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    • v.20 no.3
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    • pp.261-267
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    • 2020
  • This study used a real-scale model experiment to reproduce internal fires in residential buildings such as a multi-dwelling unit, in order to prevent damage caused by tens of thousands of fires witnessed each year and to take measures to cope with them. For experimental conditions, different opening sizes were applied to measure and analyze the heating temperature of the exterior wall. Results drawn are as following: when the experiment was conducted with opening sizes(horizontal length) each at 2,000mm, 1,600mm, and 1,400mm, the flashover occurred at 630 seconds, 505 seconds and 510 seconds, respectively. Also, the total heating time, in proportion to this, came to 815 seconds, 713 seconds and 721 seconds. The maximum heating temperature of the exterior wall by the opening size reached 282.4℃ at 2,000mm, 382.9℃ at 1,600mm, and 423.8℃ at 1,400mm. This represented that as the opening size gets smaller, the heating temperature of the exterior wall by fire spread becomes higher.

Effect of Orifice Length on Particle Distribution in Particle-laden Jet (입자 부상 제트에서 오리피스 길이가 입자 분포에 미치는 영향에 대한 연구)

  • Yoon, Jungsoo;Paik, Kyong-Yup;Khil, Taeock;Yoon, Youngbin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.16 no.6
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    • pp.9-15
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    • 2012
  • As a propellant of a high speed underwater vehicle, the hydro-reactive solid metal particles using seawater as a oxidizer maximizes its specific impulse when the solid metal particles and the seawater are uniformly mixed in the combustion chamber. The purpose of this study is to investigate the effects of injector geometry on the particle distribution of similarity point of view. For the purpose of this similarity of the mean velocity and particle number density along the radial direction was measured by Particle Image Velocimetry(PIV).

Temperature Compensation of NDIR CO2 Gas Sensor (비분산 적외선 이산화탄소 센서의 온도 보상)

  • Park, Jung-Min;Park, Young-Hwan;Yi, Seung-Hwan;Park, Jeong-Ik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.81-82
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    • 2005
  • 본 논문에서는 두 개의 오목 반사경으로 형성된 광 공동 구조의 비문산 적외선 (NDIR) 가스센서를 제작하였다. 증폭비는 18,000 배, 램프 off 시간은 3초로 일정하게 하고 펄스 modulation 시간을 200ms에서 600ms까지 변화시켰을 때. 300ms에서 가장 효율적인 출력신호를 확보할 수 있었다. 그리고 $5^{\circ}C$에서 $45^{\circ}C$까지 $10^{\circ}C$ 간격으로 온도를 변화시키면서 이산화탄소의 농도를 0ppm에서 2000ppm까지 증가시켰다. 이때, 약 400mV의 전압변화가 있었다. 온도가 상승함에 따라 0ppm에서의 출력전압은 감소하는 양상을 나타내었다. 또한 온도변화 대비 출력특성과의 상관성 해석을 통하여 온도 보상 방법을 고안하였으며, 본 연구에서 제작한 센서모듈의 응답시간은 약 30초였다.

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.A Study on Parents' Transnational Educational Passion in the Tendency of Globalization : The Potential and Limitations of Educational Nomadism (세계화의 흐름에서 학부모의 초국가적 교육열 - 교육노마디즘의 가능성과 한계를 중심으로 -)

  • Kim, So-Hee
    • Korean Journal of Culture and Arts Education Studies
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    • v.5 no.1
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    • pp.97-147
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    • 2010
  • Under the recent trend of globalization, a new proposal on education has not been able to avoid the request for multi-cultural trend. Furthermore, education has been exposed to circumstances which are far different from the previous situations in which global cooperation and intercultural understanding have been more emphasized. 'Educational Nomadism'is a metaphor of creating new value and significance of education. In fact, transnational education which could be a crisis and opportunity at the same time has recently been the mainstream throughout the world. In terms of education, Korea has encountered base hollowing-out in which excessive dependence on the US education and autonomous education coexist. In fact, the world has spent a lot of time and money to have better educational background on a resume through redundant expense by the government and parents. Under this critical situation, it's urgent to change Korea's modern education into a creative educational system in connection with an advanced foreign educational system and further develop the advantage of Korea's education. A parent's investment in his/her child is a support to create new culture as well as an assistance for hope and better future of Korean education. A new direction of parents' education fever that has opened a door to global communitas can stir up infinite potential through which the flow of education fever can be changed to the resources of new civilization. The global cooperation and efforts for communitas means the communication with this world. Through this communication, the culture in which people are forced to zero-sum competition can leap into the education for change of civilization which creates pleasure of self sufficiency and donation.