• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1996.10a
• /
• pp.76-80
• /
• 1996

공정육묘는 기후의 영향을 쉽게 받는 자연광하에서 대부분의 생산이 이루어지기 때문에 계획적인 묘생산이 어렵게 된다. 향후 식물공장(Plant factory) 또는 폐쇄생태계생명유지시스템(Controlled ecological life support system, CELSS)과 같이 폐쇄도가 높은 식물생산 시스템에서는 식물종묘 생산의 대부분이 인공광을 이용한 조건에서 이루어질 것으로 예상된다. (중략)

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.638-641
• /
• 1992

In this paper, a hybrid position/force control scheme is proposed. The control scheme modifies the position command for force control against constraint surface of environment and is very simply designed and implemented. The merits of the control scheme are that it can cope with change of constraint conditions and small position inaccuracy of the environment. A constraint surface position observer is also proposed to reduce disturbances on controlled force.

• 제어로봇시스템학회:학술대회논문집
• /
• 1990.10b
• /
• pp.1196-1199
• /
• 1990

The authors proposed a new two-dimensional(2D) positioning system by use of M-array suitable for noisy environment in '88KACC and its revised version in '89KACC. This 2D positioning system is further improved to be used in practice; the computation time is improved by use of vector signal processor and the focussing process is improved by use of an electrically controlled zoom lense. It is shown that this system is robust to noise and also to misalignment of devices.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2003.09a
• /
• pp.302-305
• /
• 2003

The electrokinetic remediation tests for natural soil contaminated by lead are performed on unsaturated conditions, in which the degree of saturation is controlled through the changes in water content and the constant unit weight. At the degree of saturation of 70% the small acid range and electrical potential is developed. The changes in the water content are little above the saturation of 90%. But it is increased by 1.7 times at the degree of saturation of 70%. Finally, the efficiency of extraction is improved at 70% than 100%.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 2003.10a
• /
• pp.217-221
• /
• 2003

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.794-799
• /
• 2006

For various historical reasons and some technical reasons, the safety of dams has been controlled by an engineering standards-based approach, which has developed over many years, initially for the design of new dams, but increasingly applied over the past few decades to assess the safety of existing dams. And some countries were asked for risk assessment on existing dam, which included structural, hydraulic safety of dam and social risk. So, Many countries were developed and could be adapted as an additional tool to assist in decision-making for dam safety management.

• Journal of Bio-Environment Control
• /
• v.14 no.2
• /
• pp.76-82
• /
• 2005

Evaporative cooling pad system is one of the main cooling methods in greenhouses and its efficiency is very high. However, it has some disadvantages such as greenhouse temperature distributions are not uniform and installation cost is expensive. In this study, a CFD simulation model f3r predicting the air temperature distribution in the fan and fad cooling greenhouse was developed. The model was calibrated and validated against experimental data and a good fit was obtained. The influence of different outside wind, fan and pad height, ventilation rate, shading, and greenhouse length, were then examined. In order to reduce the internal temperature gradients, it is desired that the prevail wind direction and the fan and pad heights are considered. The simulation indicates that high ventilation rates and shading contribute to reduce the temperature gradients in the fan and pad cooling greenhouse. In order to maintain the desired greenhouse temperature, the pad-to-fan distance should be restricted according to the design climate conditions, shading and ventilation rates. The developed CFD model can be a useful tool to evaluate and design the fan and pad systems in the greenhouses with various configurations.

• Hwankyungkyoyuk
• /
• v.22 no.1
• /
• pp.56-67
• /
• 2009

The purpose of this study is to investigate the effect on the middle school students' attitude toward environment and interest in regional ecology and environment problem with PBL. The experimental group was made up with 96 students who were sampled for this study, and PBL program was applied to this group. The controlled group consisted of 103 students who were sampled this study, and traditional teaching method was applied to this group. The result is as follows: First, there was a statistically meaningful difference in attitude toward environment between two groups(F=51.929, p<0.1). It shows that PBL is very effective in attitude toward environment. Second, there was a statistically meaningful difference in interest for regional ecology and environment problem between two groups(F=9.707, p<0.1). It shows that PBL is an effective way to take learners' interest in regional ecology and environment problem. Third, The interview result shows that students who were applied to PBL comprehensed causes, solution and importances of the environment problem. Furthermore, the self-directed learning in PBL can make learners control their learning.

• Proceedings of KOSOMES biannual meeting
• /
• 2018.06a
• /
• pp.80-80
• /
• 2018

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2016.10a
• /
• pp.151-151
• /
• 2016