• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.754-758
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• 2002

According to the enlargement of production facilities and structures, the requirements of high-capacity load cells are increased for monitoring the process conditions in many fields. Generally, however, the accuracy of the column-type high-capacity load cells is not enough due to the geometric nonlinearity. It is supposed to result from the fact that the whole spring element is under high-level stress for the uniform strain field. In this paper, a new shape of spring element is developed which utilizes the stress concentration. As a design criterion, an object function which quantifies the degree of nonlinearity is defined and optimized by use of response surface modeling. As a result, the weight of the spring element is reduced shout 50% in comparison to the conventional shape. The bonding positions of stain gages are found. which show theoretically zero geometrical nonlinearity, while the ratio of overload protection is reduced from 130% to 125% Also it is shown that the response surface method is very efficient in the optimization approach by use of FEM.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.73-81
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• 2006

In order to evaluate the thrust of a propulsion system, generally the captive thrust stand is used Based on the applied propulsion system, the various captive ways between thrust stand and the propulsion system are considered. In this paper, the effect of motor deformation generated during firing in horizontal thrust stand on the measured thrust is theoretically derived from classical beam theory. New flexure performance index is defined and estimated on the basis of the thrust measurement error. Its result is good agreement with numerical result of ABAQUS. This study showed that measurement reliability and safety of test can be highly upgraded, in case of two flexure-type captive thrust stand.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.6
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• pp.373-380
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• 2020

We have developed the hybrid prototype load cell structures. These developed load cell structures may increase the reliability of the load sensing by deriving the load values through the double sensing method through the vertical maximum deflection and bending stress of the simple beams. For this purpose, the structure design was performed so that the load value, the deflection and stress value could be output to the same value through the optimal structure design. The structurally designed dimensions reaffirmed the accuracy of the design through the structural analysis program and the matching of the load value and the deflection value. Based on the designed structural dimension, the prototype form was constructed through laser cutting and production using hot rolled steel materials. The developed prototype load cell structure can be used as good educational material in various subjects such as material mechanics, steel structure design, measurement engineering, and mechatronics engineering. It is also believed that the measurement system ideas can inform the occurrence of errors in the event of a problem, and if a major accident caused by a sensing error is predicted, it will show good utilization to prevent accidents.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.10 no.1
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• pp.14-26
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• 2011

In this paper, we've studied Optical Fiber Subscribe Transmit system. After receiving the ATM cell passing through the FIFO of the Asynchronous Transfer Method from the ATM Layer images to the VC4 signal payload passing through scrambling of the cell payload, HEC computation of the cell and inserting the Idle/Unassigned cell. At this time formed VC4 signal passing through the generating and inserting POH overhead at the same time indicating the start point of the cell by the H4 byte on the VC4 POH. This ATM cell transmits 155Mbps speed changing the optical signal after outputting the frame format at the STM-1 signal generation block through the AUG bus after generating J1 of the VC4 start point at the AU4 pointer generation block.

• Journal of the Korea Convergence Society
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• v.8 no.11
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• pp.49-56
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• 2017

Curling sweeping is one of important motion to control the position of the curling stone, and sweeping speed and applied force to the broom pad are major research subjects. In this study, a device was developed to measure the force applied to the curling broom pad in curling sweeping motion, and two load cells were mounted between the broom pad and pad holder. Analog signals generated from the load cells were sampled about 300 times per second using a micro controller, and then converted to 10-bit digital signals. Calibration of the load cell and set up of regression equations to convert the measured electrical signals into mass (force) was done by three M1 class weights, and the developed system was designed as wearable device to minimize increasing of total weight of the broom. Same force was applied to the developed system and a force plate that was using as a reference force measurement system in field of sports, and the difference between the measured values were showed about $0.909{\pm}1.375N$(mean and standard deviation). The developed system could be applied other kinds of study which required force measurement function similar to sweeping motion.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.45-49
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• 2014

In this paper, the performance of the interference cancellation using multiple receive antennas is evaluated for heterogeneous cellular systems when user association and load balancing problems are optimized for cell edge users. The simulation results show that the interference cancellation method remarkably improves the rate performance of load-balanced cells.

• Water for future
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• v.52 no.8
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• pp.84-92
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• 2019

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.1
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• pp.83-92
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• 2011

Evidence on the effect of $O_2$ reduction or current passage on the microstructure and morphology of the LSM and Ni-YSZ electrodes in solid oxide fuel cells. The microstructures of the electrodes were characterized as plate-like agglomerates. Current of $0.1\;A/cm^2$, $0.2\;A/cm^2$, $0.3\;A/cm^2$, at $800^{\circ}C$ were passed for 3 h. Then, we observed the cell structure and measured the cell performance before and after the experiment. There are changed with the load condition. The TPB of the cell increased when the cell structure changed. In particular, the decrease in activation loss is apparent as load increased. As a result, cell performance improved, and we confirmed that a optimal load condition existed.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.05a
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• pp.29-31
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• 2004

현재까지 진행된 연구는 새로운 검정 장비를 이용하여 개발된 우량 측정 메카니즘을 검정하였다. 그리고 중량식 우량계를 별도 제작하여 야외에서 정확한 우량 비교 검정을 위해 일본 쯔쿠바 대학 TERC노장에 설치하여 다음과 같은 결과를 얻을 수 있었다. 장기간 로드셀의 특성을 조사한 결과 장시간에 안정성이 입증되어 다양한 측정 장비 개발에 사용 가능함이 밝혀졌다. 새로운 검정 장비는 1 분 간격으로 정확한 강우량을 측정 할 수 있어 높은 분해능의 우량계를 검정할 수 있는 새로운 방안을 제시하였다. 본 연구의 가장 중요한 목표인 0.01 mm 급 우량 측정 메카니즘을 완성하였으며, 전도형 우량계가 가지고 있는 분해능 한계와 중량식 우량계가 갖는 배수의 문제점을 극복하였다 그리고 현업, 도시 수문, 토목 등의 여러 분야에서 요구하는 실시간 강우강도 관측 과 정확한 우량 측정이 가능한 우량계를 제작 할 수 있게 되었다. 본 연구에서 개발된 Lee-A type 우량계에 사용하는 접점신호와 로드셀의 중량 신호는 기존의 자동관측장비에 완벽한 호환성이 있어 적용에 문제점이 없다. 국내에서도 장비 개발이 충분히 될 수 있음을 알 수 있었으며, 새로운 장비 개발에 대한 가능성을 볼 수 있었다.

• Journal of Sensor Science and Technology
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• v.3 no.2
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• pp.24-32
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• 1994

A force sensor of 30 MN capacity using build-up technique in which three load cells of 10 MN capacity are arranged in parallel was fabricated. A column spring element was adopted as a shape of a strain gage type load cell. Temperature compensation circuits were used to reduce the error of a load cell. It was estimated that the total error of the fabricated force sensor is less than 0.1 %. The force sensor may be used to calibrate or test material testing machines above 4.5 MN capacity in industries.