• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.315-318
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• 2002

우리나라 원예시설면적은 '00년 말 현재 52,189ha이며, 이중 단동형 비닐하우스 면적은 채소가 34,173ha로 대부분을 차지하고 있다. 단동형 비닐하우스에 사용하는 골재는 주로 ø25mm를 95%이상 사용하고 있으며, 서까래 간격은 지역별로 다르나 대부분 80cm 이상으로 설치되어 있다. 이와 같은 골재와 서까래간격은 구조적으로 매우 취약하여 자연재해에 대비하기 위해서는 자연재해시 사전ㆍ사후대책이 필수적이며, 근본적으로는 비닐하우스 구조적 안전성이 확보되어져야 한다. (중략)

• Journal of the Ergonomics Society of Korea
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• v.25 no.4
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• pp.153-157
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• 2006

The objective of this study was to establish a systematic ergonomic program for the prevention and control of work-related musculoskeletal disorders(WMSDs) in a machinery manufacturing company. The steps such as looking for the signs of WMSDs problems, setting the stage for action, training-building in-house expertise, gathering and examining the evidence of WMSDS, developing controls of health care management, and proactive ergonomic interventions were applied. The primary success factors were management commitment and encouragement, and harmonious union-management relations.

• International Journal of Fluid Machinery and Systems
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• v.9 no.1
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• pp.57-65
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• 2016

By high speed Liquid Droplet Impingement (LDI) on material, fluid systems are seriously damaged, therefore, it is important for the solution of the erosion problem of fluid systems to consider the effect of material in LDI. In this study, by using an in-house fluid/material two-way coupled method which considers reflection and transmission of pressure, stress and velocity on the fluid/material interface, high-speed LDI on wet/dry material surface is simulated. As a result, in the case of LDI on wet surface, maximum equivalent stress are less than those of dry surface due to damping effect of liquid film. Empirical formula of the damping effect function is formulated with the fluid factors of LDI, which are impingement velocity, droplet diameter and thickness of liquid film on material surface.

• The KSFM Journal of Fluid Machinery
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• v.20 no.2
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• pp.32-40
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• 2017

In this study, an in-house program to analyze the performance degradation for gas turbines is developed using MATLAB and is validated using commercial software. This program consists of design and off-design calculations. The results of design calculation is used for reference values of off-design calculation. The off-design calculation is composed of measured and expected performance analyses, and turbine inlet temperature correction. In general, performance degradation is analyzed by comparing the results of measured and expected performance analysis. However, if gas turbine performance degrades, turbine inlet temperature might increase due to the general control logic to comply with the power demand. Therefore, it is required to consider the deviation of turbine inlet temperature from the normal value in the performance diagnosis to analyze the performance degradation exactly. In this study, a special effort is given to the correction of turbine inlet temperature. The accuracy of the developed program is confirmed by comparison with commercial software, and its capability of performance diagnosis using the turbine inlet temperature correction is demonstrated.

• 유체기계공업학회:학술대회논문집
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• 2001.11a
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• pp.413-418
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• 2001

Emergency shut-on valve was developed to shut off natural gas at the front of a gas meter in the house. The shut-off flow rate and differential pressure of this valve was controlled by adjusting the distance between the spool and magnet. Also the spool shape was an important factor in the performance of this valve. The experimental and computational results will be useful for the design having better performance.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1999.11a
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• pp.253-255
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• 1999

We measured stand-by power of electrical machinery and appliance which are used at office and house. And we estimated potential electrical energy saving through stand-by power and the expecting number of supplied apparatus. As a result, We can reduce electrical energy by minimizing a stand-by power consumption up to three billion kWh which are equal to about 1/3 of an atomic power plant's generating power of 1 year.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.102-102
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• 2004

산업과 경제의 발달로 그 수요가 급속도로 증대되고 있는 항만물류를 처리하기 위한 여러 가지 항만하역장비에서 가장 핵심은 컨테이너를 선박에 양ㆍ적하하는 장비인 컨테이너 크레인이라 할 수 있다. 최근에는 이러한 컨테이너 크레인도 초대형 컨테이너선의 출현으로 인하여 이에 맞는 구조나 작동 방식을 보유할 수 있도록 연구가 활발히 진행되고 있다.(중략)

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.327-335
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• 1991

In Korea, farming population is rapidly decreased in each decade. Consequently, farming is becoming more complex with multi cropping, animal production and green house farming. In order to encounter this complexity of farming, expert system applications on diagnosis, planning, designing, management, control, and training are demanded to meet the needs of agricultural society. In this article, expert system establishment procedures are stated step by step and extensive literature review was conducted on the expert system development techniques.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.4
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• pp.78-83
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• 2011

Natural gas is one of the most promising alternatives to gasoline and diesel fuels because of its high thermal efficiency and lower harmful emissions, including $CO_2$. Although the high octane value of natural gas increases engine output and efficiency due to the high compression ratio, this fuel is prone to such difficulties as a narrow limit of inflammability and a slow combustion speed in the lean burn operation domain, leading to unstable combustion and higher emissions of harmful exhaust gases. Hydrogen blended with natural gas can extend the lean burn limit while maintaining stable, efficient combustion and achieving lower NOx, hydrocarbon and green house gas emissions. In this study, the effect of hydrogen addition on an engine performance and NOx emission characteristics was investigated in a heavy duty natural gas engine. The results showed that thermal efficiency was increased and NOx emissions were reduced due to the expansion of lean operation range under stable operation. NOx emission can be significantly reduced with the retard of spark advance timing.

• Journal of Biosystems Engineering
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• v.40 no.4
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• pp.368-372
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• 2015

Purpose: The purpose of this study is to verify the feasibility of using an infrared sensor to measure the body temperature of a sow. We first conducted experiments on three pigs by using three infrared sensors and one indoor temperature sensor. Methods: The three infrared sensors were installed inside our model house and were used to take temperature measurements per second of the backs of the pigs. While feeding, the temperatures of the backs of the pigs were measured at distances of 10 cm, 20 cm, and 30 cm from the infrared sensors. Results: We concluded that the relation between the temperature of the pigs' backs and the indoor temperature was y =0.549x + 18.459 at a measuring distance of 30 cm. The relation was y = 0.645x + 15.461 for a distance of 20 cm and y = 0.760x + 11.913 for a distance of 10 cm. We found high correlation between the indoor temperature and the temperature of the pigs' backs. Conclusions: It is possible to use an infrared thermometer to monitor the temperature of pigs' backs. This system seems to be feasible and effective in monitoring pig temperature. The use of an infrared thermometer will also make daily monitoring easy. In later experiments, the possibility of developing a system that can determine if an error can be corrected by using infrared sensor is explored by considering humidity variables.