• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.994-999
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• 1993

To service with high quality electricity to customer, the utilities consider the DAS (Distribution Automation System) as a good means of it. The backbone of the DAS are communication and computer technique. Most of all, from the economical and functional point of view, the selection of transmission media for system communication is the key factor to achieve a successful DAS. In this paper author propose the method of the DAS communication which share its channel with CATV transmission line and analyze the effect.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.05a
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• pp.62-64
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• 1997

작물생육은 근권 부근의 온도와 밀접한 관계가 있다. 따라서 외부환경의 영향을 받기 쉬운 단순 경량화된 순환형 무토양재배시스템내의 양액 또는 배지의 온도 변화를 파악하여 환경조절을 통한 적정 생육환경을 조성할 수 있다면, 작물의 생산성에 기여할 수 있다. 본 연구는 순환식 무토양재배시스템의 위치별 온도 분포 및 배양액의 공급 과 온도변화와의 관계를 분석하였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.07a
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• pp.374-375
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• 2017

As the distribution of image contents is activated, users can easily access image contents through various routes and media.In this paper, we propose a new virtual reality (VR) system, which is based on the development of IT technology, in order to prepare for the fourth industrial revolution era.We propose a method of producing educational video contents that combines maximized virtual reality.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.355-357
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• 2004

최근 무선통신기술의 발전으로 PC뿐만 아니라 PDA, 휴대폰 등 다양한 장치를 통하여 멀티미디어 서비스를 제공받을 수 있게 되었다. 무선망은 유선망에 비해 대역폭이 낮기 때문에 높은 비트율을 갖는 스트림을 낮은 비트율로 변환하기 위해 트랜스코딩을 이용한다. 따라서 이러한 트랜스코딩 시스템에서 효율적으로 무선 스트리밍을 전송하기 위해서는 부하분산에 관한 연구가 필요하다 본 논문에서 제안한 클러스터 트랜스코딩 시스템은 스트리밍 서비스의 모바일 호스트 등급에 따른 CPU 사용량, 네트워크 대역폭, 메모리의 가중치를 계산하여 부하 배분에 사용할 수 있는 부하 분산 모델을 제시한다.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2038-2043
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• 2007

Analysis of the internal state of the blast furnace is needed to predict and control the operating condition. Especially, it is important to develop modeling of blast furnace for predicting cohesive zone because shape of cohesive zone influences on overall operating condition of blast furnace such as gas flow, temperature distribution and chemical reactions. Because many previous blast furnace models assumed cohesive zone to be fixed, they can't evaluate change of cohesive zone shape by operation condition such as PCR, blast condition and production rate. In this study, an axi-symmetric 2-dimensional steady state model is proposed to simulate blast furnace process using the general purpose-simulation code. And Porous media is assumed for the gas flow and the potential flow for the solid flow. Velocity, pressure and temperature distribution for gas and solid are displayed as the simulation results. The cohesive zones are figured in 3 different operating conditions.

• ETRI Journal
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• v.32 no.6
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• pp.940-949
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• 2010

Rack-level DC power supply is the optimal technology for providing DC power to a volume server without any power infrastructure changes in an existing AC data center. In this paper, we propose a smartly controllable and monitorable DC rack power system. The proposed system improves power efficiency by changing the power distribution architecture of a conventional method in the rack. We developed an optimal power control method in multipower modules to provide high efficiency at low loads. In addition, the proposed system provides real-time web monitoring of the rack power and environment around a rack. In our experiments, the proposed system improved the power efficiency by over 10% compared to an AC power system providing N+1 redundant power and power monitoring.

• Applied Microscopy
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• v.47 no.3
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• pp.101-104
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• 2017

In this investigation, synchrotron X-ray imaging was used to investigate the water distribution inside newly developed gas diffusion media in polymer electrolyte membrane fuel cells. In-situ radiography was used to reveal the relationship between the structure of the microporous layer (MPL) and the water flow in a newly developed MPL equipped with randomly arranged holes. A strong influence of these holes on the overall water transport was found. This contribution provides a brief overview to some of our recent activities on this research field.

• Korean Journal of Poultry Science
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• v.26 no.1
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• pp.27-33
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• 1999

The distribution of oviductal vessels of eight Korean native pheasants was observed after Latex casts of vessels. Latex was injected into thoracic aorta and posterior vena cava of these birds for cast preparation. The results were as follows: 1. The arteries suppling oviduct of the Korean native pheasants contained A. oviductalis cranialis, media, caudalis and vaginalis. The veins drainaging oviduct were stretched along the following ateries and all of the oviductal vessels were situated on the left side of the body. 2. The anterior oviductal artery arose from the pubic artery of the left external iliac artery and distributed to the infundibulum and the magnum of the oviduct. 3. The middle oviductal artery arose from the left sciatic artery and distributed to the isthmus and shell gland of the oviduct. 4. The caudal artery arose from the left internal pudendal artery of the median sacral artery and distributed to the caudal part of uterus and the cranial part of vagina. 5. The vaginal artery arose from the left internal pudendal artery of median sacral artery and distributed to the caudal part of vagina.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.275-277
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• 2011

손실 채널의 데이터 손실을 보상하는 오류 정정 부호로 주로 사용되는 LT 부호는 일반적으로 RSD (robust soliton distribution)을 따르는 nonsystematic 구조를 가진다. RSD 를 따르는 유한한 길이의 LT 부호의 경우 높은 손실률 가진 채널 환경에서는 적합하지 않다. 본 논문은 기존의 RSD 를 다소 변형하여 systematic LT 부호에 적합한 무게 분포를 설계 방법을 제시하고, 시뮬레이션을 통해 기존의 RSD 를 이용한 LT 부호와 논문에서 제안하는 systematic 성질을 가진 LT 부호의 성능을 비교해 본다.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.23-30
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• 2009

Slow sand filtration (SSF) was the first engineered/mechanical filtration process used in drinking water treatment. In SSF, untreated water slowly percolate through a bed of porous sand. Biological activity within the sand bed have the strongest influence on removal efficiency of pollutants by slow sand filtration. In this study, the microbial population distributions in slow sand filters operated at the various operation conditions was evaluated. The concentrations of $10^4$ to $10^5$ CFU per g dry wt. were observed. No significant differences were seen between the number of filter-covered materials. The data indicate that the temperature has affect on population distribution. Also, the light exposure was influenced on microorganism in slow sand filtration according to the heterotropic plate counts. The role of microorganism within the sand media requires further study.