• 한국초전도ㆍ저온공학회논문지
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• 제6권1호
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• pp.43-48
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• 2004

This paper deals with design and fabrication of heater-triggered switching system for the high-Tc superconducting (HTS) power supply with series-connected double-pancake load. Amongst all components, heater triggering is the most important element for the performance of HTS power supply. To fabricate the optimal heater-triggered system, its characteristics have been analysed through the simulation and expriment. The thermal analysis of switching parts of the Bi-2223 solenoid according to the heater input was carried out. Based upon the analysis, 8A electromagnet current and 1.5A DC Heater current were optimally derived, and 8s and 20s for the pumping period were selected in this experiment. In the experiment. the maximum pumping current reached about 24A with Bi-2223 pancake load of 6mH.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.204-209
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• 2007

This study was carried out to analyze the effect of wind load on the structural stability of a container crane according to the increase of the lifting capacity using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with $11.52m^{2}$ cross-section area. Each directional drag and overturning moment coefficients were investigated.

• 한국기계가공학회지
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• 제2권4호
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• pp.46-52
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• 2003

For position control of electro-hydraulic servo system, single rod cylinders and double rod cylinders are used. Single rod cylinders have simple structure for manufacturing but different volume ratio of two sides induce to non-linearity in process of then mathematical modeling. So only with conventional PID control method it is difficult to control single rod cylinders precisely. For mole precise position control of single rod cylinders, a controller which is inserted a velocity feedback PID controller and MRAC controller are proposed. With experiment control performances of three control methods are compared. In case of experiment, for external varying load to the system, a hydraulic cylinder and a pressure control valve are used. In conclusion a MRAC is considered a suitable control method for external varying load.

• 반도체디스플레이기술학회지
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• 제18권1호
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• pp.25-31
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• 2019

In this study, a new adhesion evaluating equipment and data processing methods were developed to overcome some limitations of existing evaluating equipment. Nano-diamond coated tool is a specimen of experiment. When applying frictional force and shear force on the specimen by a rotating polishing pad, delamination occurs at a moment. During each experiment, the vibration, load, and torque is obtained by accelerometer, loadcell and torque s+ kpensor. Frictional force and coefficient of friction are obtained by calculating torque and load. Based on FFT transformation, acceleration is processed and analyzed. As a result, the moment of delamination and the load at that time can be detected by the new developed equipment and measurement system. Finally, we call this load as an Adhesion force.

• 한국수자원학회논문집
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• 제56권1호
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• pp.23-34
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• 2023

본 연구에서는 실내실험과 수치모의를 통해 식생대에서의 소류사 이동 및 하도 변화를 분석하였다. 실내시험에서 식생대의 영향을 검토하기 위해 아크릴 봉으로 제작한 인공 식생대를 실험수로에 설치하였으며, 유량 조건을 조정하여 유량변화에 따른 식생대에서의 소류사 이동 및 하도 변화를 검토하였다. 다음으로 실내실험과 동일한 조건을 2차원 수치 모형인 Nays2D모형에 적용하여 수치모의를 수행하고, 그 결과를 실내실험 결과와 비교하여 수치모형의 적용성을 검토하였다. 마지막으로 적용성을 검토한 수치모형을 적용하여 식생밀도의 변화에 따른 소류사 이동 및 하도의 변화를 검토하였다. 실내실험과 수치모형을 적용하여 유량변화에 따른 식생대에서의 소류사 이동 및 하도 변화를 검토한 결과, 두 적용 방법의 결과가 유사하게 나타났다. 유량이 증가함에 따라 상류에서 유입된 소류사가 식생대 내부에 퇴적되었으며, 식생대 반대편에는 흐름이 집중되어 침식이 발생하였다. 또한 시간이 지날수록 하류방향으로 침식범위가 증가하였다. 식생밀도의 변화에 따른 소류사 이동 및 하도의 변화를 검토한 결과, 식생대의 식생밀도가 증가할수록 상류에서 유입된 소류사가 식생대 내부에 퇴적되었다. 또한 식생밀도의 증가로 인하여 흐름이 식생대의 반대편으로 집중되어 식생대 반대편 하도의 침식이 발생하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.666-671
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• 1993

Fatigue life prediction under multi-axial variable load were performed for Aluminium 7075-T651 alloy using SAE Notched specimen & Torque tube shaft component specimen. When variable multiaxial load is applied to material, maximum damaged plane(critical plane) change. To clarify the situation, experiment is performed on two different changing load path. For multiaxial fatigue life prediction, miner rule is expanded to critical plane theory. Shear based parameter and Elliptical parameter give better correlation. This suggests that miner rule can be applicable on multi-axial variable load.

• 한국해양공학회지
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• 제10권4호
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• pp.67-74
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• 1996

The paper focuse on the effect of a crack subjects to collaspe behabiors of statically indeterminate beams under concentrated load. Through the experiment and calculation, it was revealed that the collaspe load of statically indeterminate beams is much higher than that of statically determinate beams. The cumulative AE event counts of statically determinate beams was less than that of statically indeterminate beams, and the center notch beams sas revealed less than that of the side notch beams.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.325-327
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• 1999

In this research, selection of component load and measurement device is considered for accurate component load modeling. The procedure of component load characteristic experiments is also presented.

• 대한인간공학회지
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• 제23권4호
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• pp.45-56
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• 2004

The purpose of this study is to evaluate perceived discomfort of working postures in terms of upper body (back, shoulder, and elbow) flexions when an external load varies. Eighteen subjects participated in an experiment of appraising perceived discomfort of varying upper body postures with three levels of external loads given. The ANOVA results showed that the perceived discomfort of upper body postures was significantly affected by the external load. It was also apparent that the interactions between external load and upper body posture were significant (p< 0.001). The result implies that a new posture classification scheme for workload assessment methods may be in need to reflect such interactions between external load and upper body posture. In order to support the statement, a regression model of perceived discomfort of upper body postures obtained from the experiment was developed and compared to that of perceived discomfort of seven work-related postures found in automobile assembly operations. The correlation coefficient between predicted and actual values of perceived discomfort was about 0.96. It is expected that the result help to properly estimate the body stress resluting from worker's postures and external loads and can be used as a valuable design guideline on preventing work-related musculoskeletal diseases in industry.

• 설비공학논문집
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• 제18권12호
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• pp.947-954
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• 2006

Building energy consumption according to the ventilation has been considered to be an important subject. The purpose of this study is to investigate the cooling and heating loads in a test space with a forced ventilating system. In the test space, on/off controlled air-conditioning and forced ventilating facility were operated between 8 : 30 to 21 : 00 during 4 days and some important data like temperatures and energy consumption were measured to obtain actual thermal loads. The simulation was carried out in a mode of temperature level control using a TRNSYS 15.3 with a precisely measured air change amount and performance data of air-conditioner. Heating load and cooling load including sensible and latent were compared between by experiment and by simulation. Both of thermal loads associated with ventilation show a close agreement within an engineering tolerance.