• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.4
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• pp.221-229
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• 2008

This study analyze indoor thermal comfort properties such as PMV, PPD and fluid variables when the cooling loads are light, occupant and ventilation. There are 6 cases to study for the indoor unit installation conditions and ventilation rates. Numerical method is used to study the indoor environmental properties and experimental study is adapted to analyze reaching time by variable cooling load conditions.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.12
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• pp.2385-2394
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• 1992

Granular solid propellants having energy and fast burning rate produce great thrusts within extremely short time intervals. Thus numerical researchs prevailed rather than experimental. Using a 2-phase fluid dynamics model among 1-dimensional 2-phase models, a numerical program was set up to describe reacting flow fields, moving boundary with oscillating pressure waves and constitutive laws research. It deserves special emphasis that correlations of convective heat transfer coefficient and viscous drag force among constitutive laws are tested and discussed because slight variations of their constants make a large influence on their results. In this calculations, some of correlations make the large difference in results. Therefore constitutive laws for convective heat transfer coefficient and viscous drag force need more considerations with experiments.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.32 no.10
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• pp.17-21
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• 2003

국내 화장실 양변기의 배수 및 세정소음에 관한 실험실 측정결과를 소개하고자 한다. 1989년 대한주택공사에서 조사한 설문조사에 의하면 공동주택에서 외부로부터 들리는 소음에 대한 불만을 조사한 결과, 바닥충격음, 급배수설비 소음, 그리고, 공기전달음의 순으로 나타났다. 이와 같이 급배수시 발생소음은 공동주택 입주자의 주요한 민원중의 하나이다. 급배수설비 소음은 유체의 유동에 의하여 발생하며, 직접 공기중을 전파하여 가는 “공기전달음”과 배관지지 재료 및 구조체 등을 통해 재차 공기중을 전파하여가는 “고체전달음” 으로 구분된다. 여기서 “공기전달음”이란 실내에서 발생한 소리가 구조체를 진동하고 구조체는 인접실의 구조체 주변의 공기를 진동하여 소리가 방사되거나 또는 인접실간에 열려 있는 통로를 거쳐 전달되는 소음을 말하고 “고체전달음”이란 음원이 접하고 있는 건물구조체를 통하여 진동의 형태로 전달되는 소음을 일컫는다. 공동주택에서 배수관은 아래층 천장배관에 해당되므로 배수관에서 발생하는 소음은 아래층으로 직접 전달된다. 이러한 배수설비 소음은 배관재의 종류, 배관스페이스의 구조 및 위치 등에 따라 소음레벨이 달라지게 된다.(중략)

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.265-272
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• 1998

In this paper, the intoner noise reduction for subway railroad vehicles was studied by improving transmission loss of carbody panels and side doors, and on-line tests were conducted to examine the exterior noise levels at various running conditions. Also the transmission loss for design candidates of the carbody specimen was measured in two reverberation rooms. From the results of the tests, side door gap is the most dominant factor affecting the Interior noise level of subway railroad cars with a sliding typed side door. The next one is revealed to transmission loss of a floor panel. To improve the transmission loss of the carbody, many activities were conducted such as, treatment of resilient and sound-absorbing materials and reducing the gap of the side door by adopting a brush and rubber, etc. The estimated interior noise level for modified car which is designed with improved carbody panels is lower than original car by about 5㏈.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.4
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• pp.509-514
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• 2000

A numerical study has been performed to design duct parameters in the freezer of a domestic refrigerator. The visualization results of FDM analysis using the standard k-$\varepsilon$ model with inlet boundary conditions modelled in this paper show good agreements with the experimental ones in prediction overall flow characteristics. Dominant vortex flows are found in the left upper and right lower corners, while there exists large turbulent kinetic energy around the fan and right upper side of the fan. It, in turn, has effects on the performance and noise. It is recommended to locate the outlet far away from the fan in order to reduce the noise level.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.4
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• pp.301-306
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• 2016

This paper presents the results of a study for robust self-localization and indoor slam using external cameras (such as a CCTV) and odometry of mobile robot. First, a position of mobile robot was estimated by using maker and odometry. This data was then fused with camera data and odometry data using an extended kalman filter. Finally, indoor slam was realized by applying the proposed method. This was demonstrated in the actual experiment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.221-226
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• 2008

A typical unsteady internal ballistic analysis model was proposed to take account the erosive burning with the variance of local velocity and pressure along grain surface to the axis of a solid rocket combustor. The model introduced in this study showed good agreements with the results of previous research. It was investigated that the combustion pressure, grain length, initial temperature, and vaporization temperature of propellant affect on the erosive burning.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.163-164
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• 2014

Pseudolite systems are used for backup systems of GPS satellite or indoor navigation systems. The pseudolite transmits GPS-like signal on the ground. Fundamentally, to estimate a position, clock synchronization among satellites is essential, because GPS receiver uses measurement based on TOA. Therefore, in order to improve the navigation performance in applications using pseudolite, clock synchronization with GPS satellites is required. This paper proposes design of monitoring system for pseudolite clock synchronization. The monitoring system analyzes clock synchronization accuracy of pseudolite and can be used for clock adjustment.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.972-975
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• 2021

최근 한국 여름 기후의 열대화 현상이 급속화 됨에 따라 잦은 장마와 태풍으로 인해 방제 약품이 씻겨나가 방제가 제대로 안되는 경우가 많아졌다. 이는 식물과 작물들이 병해에 약해지는 계기를 만들었다. 따라서 본 논문에서는 그 중 실내 농사가 어려운 감귤에 중점을 잡고 감귤에서 주로 나타나는 흑점 영상 인식에 대한 모델을 제안하였다. HSV 공간으로의 변환과 LBP 기법을 통해 간단하지만 인식률을 높일 수 있는 방안을 마련하고자 했다. 자원과 계산을 효율적으로 사용하기 위해 모델을 간략화 하였으며 추후 스마트팜의 연구에 도움이 될 수 있을 것이라 기대한다.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.308-316
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• 2015

This study was conducted to investigate the situation of ICT apply to plastic greenhouse, and the results be apply to design of new one. A CFD analysis were conducted to monitering the ventilation and energy saving of the single span greenhouse newly designed. The causes of delay to apply ICT to plastic greenhouse are the high cost for installation(24%), insufficiency of after services(19%), often disorder(16%), unskillful management of soft ware(15%), insufficient ICT efficiency(13%) and unsatisfying of income increase(12%). The parts of problem occurred in ICT plastic greenhouse are the structure, actuator, environmental control system and sensor(approximate 14%, respectively), remote control technique(13%), plant management technique(12%), energy saving technique(10%) and utilization of software(8%). In the condition of lateral window closed, the average wind speed changed to slow, but it was faster in the condition of leeward side window opened than in the condition of lee and winward side window opened. The air movement in the condition of lateral window closed occur by air moving fan not by out air. It is not affect the room temperature but effective the uniformity of room temperature. The average temperature of low height greenhouse was uniform than high height one. The average temperature in condition of 3rd curtain opened become same with outside temperature after 2 hours, but take more 5 hours in condition of 3rd curtain closed.