• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 한국항해항만학회 2009년도 추계학술대회
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• pp.134-135
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• 2009

선박에서 주로 채택되는 열교환기는 쉘튜브형과 판형열교환기로 분류된다. 이 연구에서는 소형쉘튜브형 열교환기의 설계에서 중요한 요소인 냉각튜브와 벽면과의 간격에 따른 유동특성을 입자영상유속계를 이용하여 계측하였다. 연구 결과 벽면과의 거리변화에 따른 임계간격비는 0.25전후로 추정되었으며 벽면효과에 따른 정량적 데이터를 확보하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제18권8호
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• pp.344-349
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• 2017

Wall-climbing robots have been developed for various purposes, such as cleaning skyscraper windows, maintaining large structures, and welding vessels. Conventional wall-climbing robots use movement systems based on wheels or legs. However, wheeled robots suffer from slipping effects, while legged systems require many actuators and control systems for the complex linkage structure, which also increases the weight of the robot. To overcome these disadvantages, we propose a new wall-climbing robot that walks based on gorilla locomotion. The proposed robot consists of a DC drive motor, a vacuum pump for adsorption, and a micro controller for controlling the system. The performance of the robot was experimentally verified on vertical and horizontal flat surfaces. The robot could be used for various functions in industrial sites or disaster areas.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제34권12호
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• pp.67-74
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• 2006

An unsteady blockage-correction method utilizing wall pressure distribution on the test section has been developed for the wall interference correction of a closed test-section subsonic wind tunnel. The pressure distribution along the test section wall was decomposed into Fourier series and a quasi-steady method based on a measured-boundary-condition method was applied to each Fourier coefficient. The unsteady correction for a complete test period was accomplished by recombining each corrected terms. The present method was validated by appling computed unsteady flows over a cylinder and an oscillating airfoil in the test sections. The corrected results by the present method agreed well with free-air condition.

• Journal of the Korean Institute of Landscape Architecture
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• 제42권5호
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• pp.88-100
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• 2014

The purpose of the study is to analyze the regional effectiveness of wall-plantings by applying a biotope area ratio when wall-plantings are constructed in high density areas. For this, this study required a sample of the wall-planting's regional plan. Therefore, types of wall-planting were determined and applied to a sample site. Four types of wall-plantings were developed by formative features and functional features. Type "A" had simple and functional features, Type "B" had both mixed and functional features, Type "C" had both simple and landscape features and Type "D" had mixed and landscape features. Jung-gu District in Seoul was chosen as the sample site. Total investigations were performed three times for three months from June to August, 2011. Total green-able walls were located in 498 places with a total length of 8,449m and gross vertical area of $23,754.90m^2$. The classification results of total green-able walls by the four types were Type "A" at $1,936.65m^2$, Type "B" at $5,875.30m^2$, Type "C" at $12,487.85m^2$ and Type "D" at $3,455.10m^2$. This study analyzed how all facade areas of the green-able walls impacted the biotope area ratio at the site. First, the biotope area ratio regarding all the zones in Jung-gu District was defined as the gross biotope area ratio while the biotope area ratio regarding all of the artificial zones was defined as the net biotope area ratio. In the case of the gross biotope area ratio, 17.97% is current ration with a projected increase to 0.10% after wall-planting. In the case of the net biotope area ratio, 4.73% is the current ration with a projected increase to 0.11% after wall-planting. This 0.11% is about 2.28% of 4.73%. This study looks at all wall-plantings that have been constructed throughout a high density area to observe their impact on the improvement of ecological function therein. With consideration of the landscape value of the facade, the regional effectiveness of wall-planting is expected to increase even more.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2013년도 추계학술발표대회
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• pp.1421-1424
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• 2013

본 논문은 진공을 이용한 흡착방식과 바퀴형 이동방식을 이용하고 환경 탐지용 센서를 부착한 벽면 이동형 로봇의 구현에 관한 연구로서, 대형 구조물의 안전 검사 및 위험한 시설물의 보수 작업등을 보조하기 위한 목적이 있다. 로봇의 무게에 따른 중력을 견딜 수 있도록 강력한 진공흡착방식을 고안하여 다양한 벽면재질에도 견딜 수 있도록 설계하였으며, 바퀴형 이동방식을 택하여 높은 이동성과 제어 능력을 고려하였다. 벽면의 모서리를 이동하기 위해 이중 벽로봇 구조와 모서리 극복 이동 메카니즘을 제안하였으며 또한 환경 감지를 위한 카메라를 부착하여 시각정보 등 유용한 정보를 관리자와 통신을 통해 교환할 수 있도록 하여 지능능력과 활용성을 갖추었다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제33권7호
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• pp.1-8
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• 2005

For study on the unsteady wall interference effect, flows around a circular cylinder in closed test-section wind tunnels have been numerically investigated by solving compressible Navier-Stokes equations. The numerical scheme is based on a node-based finite-volume method with the Roe's flux-difference splitting and an implicit time-integration method coupled with dual time-step sub-iteration. The computed results showed that the unsteady pressure gradient over the cylinder is enhanced by the wall interference, and as a result the fluctuations of lift and drag are augmented. The drag is further increased because of the lower base pressure. The vortex shedding frequency is also increased by the wall interference. The pressure on the test section wall shows the harmonics having the shedding frequency contained in the wall effect.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제36권7호
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• pp.621-627
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• 2008

Aerodynamic data measured in a wind tunnel has inevitable errors due to the presence of the wind tunnel walls. These unwanted interference effects must be corrected for the wall interference free aerodynamic data. Streamline curvature effects are caused by straightening of streamlines due to wind tunnel walls. Classical Glauert's correction method that is a standard method for fixed wing aircraft is not suitable for rotary wing aircraft. In this paper, Heyson's correction method of which wake model is compatible with rotors is used to correct the rotor shaft angle as well as the dynamic pressure. The results of Heyson's method are compared with Glauert's correction method.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2011년도 추계학술발표대회
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• pp.253-256
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• 2011

본 논문은 진공흡착방식과 바퀴형 이동방식을 이용한 벽면이동형 지능로봇의 구현에 관한 연구로서, 대형 구조물의 검사 및 위험한 시설물의 보수 작업등에 사람을 대신하여 활용하는데 그 목적이 있다. 로봇의 무게에 따른 중력을 견딜수 있도록 강력한 진공흡착방식을 고안하여 불규칙한 벽면재질에도 견딜 수 있도록 설계하였으며, 바퀴형 이동방식을 택하여 이동을 위한 구조가 단순하고 제어 능력이 뛰어나다. 또한 환경 감지용 센서와 시각정보를 관리자와 통신을 통해 교환할 수 있도록 하여 지능능력과 활용성을 갖추도록 하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 한국방송∙미디어공학회 2016년도 추계학술대회
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• pp.199-200
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• 2016

전 세계적으로 효율이 높은 LED 조명이 각광 받기 시작하면서 기존의 조명보다 에너지 효율이 높은 LED 조명을 보다 효율적으로 사용하기 위한 다양한 방법들에 대한 관심이 높아지고 있다. 이에 본 논문에서는 기존의 스위치 구조의 제품을 분석하여 한계점을 파악하고, 사용자가 스위치를 교체하는 단순한 방식으로도 스마트 조명을 경험 할 수 있도록 LED조명을 효율적으로 사용하기 위한 벽면형 스위치 구조를 디자인 하고자한다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제32권1호
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• pp.1-12
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• 2004