• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.56-62
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• 2011

Terrain recognition ability is crucial to the performance of legged robots in an outdoor environment. For instance, a robot will not easily walk and it will tumble or deviate from its path if there is no information on whether the walking surface is flat, rugged, tough, and slippery. In this study, the ground surface recognition ability of robots is discussed, and to enable walking robots to recognize the surface state and changes, a central moment method was used. The values of the sensor signals (load cell) of robots while walking were detected in the supported section and were analyzed according to signal variance, skewness, and kurtosis. Based on the results of such analysis, the surface state was detected and classified.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1770-1773
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• 2005

The performance evaluation of AOV(air-operated valve) requires the processes to confirm the actuator system capability. It is necessary to evaluate the thrust of the air actuator for the margin evaluation. In this paper, to evaluate and analysis the air actuator, the performance test system and operating program are developed. This system is composed of several sensors such as pressure sensor, LVDT, and LoadCell which are used to get the data for evaluation. The LabVIEW was used for developing the operating program. The test system and operating program are proved through the actual test of the diaphragm actuator.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1318-1319
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• 2011

In this paper, we analyzed of growth and electrical characteristics of micro-cracks with thermal effect in PV module. The micro-cracks are increasing the breakage risk over the whole value chine from the wafer to the finished module, because the wafer or cell is exposed to mechanical stress. we experimentally analyze the direct impact of micro-cracks on the module power and the consequences after artificial aging. The first step, we made micro-cracks in PV module by mechanical load test according to IEC 61215. Next, PV modules applied the thermal cycling test, because microcracks accelerated aging by thermal cycling test. according to IEC61215. Before every test, we checked output and EL image of PV module.

• Journal of Environmental Science International
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• v.10 no.5
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• pp.323-327
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• 2001

A new method is developed to estimate the evaporation of water from a surface with high accuracy and resolution. The principle of new method is to detect a weight change of buoyant weight according to a change in water level of Class A Pan mesured by the use of a strain-gauge load cell. Field test of evaporation recording new instrument was carried out at Suwon for 10 days July 1999. It is possible in field observation to measure hourly evaporation amount by newly developed evaporation recording instrument in Class A Pan against strong solar radiation. Present study provide a possibility of domestic high accuracy instrument development below than 0.1mm water level measurement accuracy. If there is low humidity and high wind speed conditions which is possible to evaporate from water surface during night time. And it needs continuous study to understand between meteorological elements and latent heat effect at ground level by field observation study using high accuracy evaporation recording instrument.

• Journal of Environmental Science International
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• v.8 no.4
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• pp.419-422
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• 1999

A new method is developed to measure rainfall with high accuracy and resolution. The principle of new method is to detect a weight change of a buoyant weight according to a change in water level of raingage measured by the use of a strain-gage load cell. Field test of the method was carried out on 30 September 1998, when there was heavy rainfall with total amount of 189.60mm. The results are as follows; 1) In spite of heavy rainfall, this new method showed the total error of only 1.5% against the total amount of 189.60mm. 2) This new mechanism accomplished high accuracy and resolution at filed test in heavy rainy day. 3) The present study provided a possibility to develop a new raingage with an 0.01mm in rainfall measurement.

• ETRI Journal
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• v.32 no.5
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• pp.722-728
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• 2010

This paper presents the design and fabrication model of a touchpad based on a contact-resistance-type force sensor. The touchpad works as a touch input device, which can sense contact location and contact force simultaneously. The touchpad is 40 mm wide and 40 mm long. The touchpad is fabricated by using a simple screen printing technique. The contact location is evaluated by the calibration setup, which has a load cell and three-axis stages. The location error is approximately 4 mm with respect to x-axis and y-axis directions. The force response of the fabricated touchpad is obtained at three points by loading and unloading of the probe. The touchpad can detect loads from 0 N to 2 N. The touchpad shows a hysteresis error rate of about 11% and uniformity error rate of about 3%.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.8
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• pp.498-500
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• 2005

In a CDMA system, the capacity is variable and mainly depends on multiple access interference. The multiple access interference has a deep relationship with transmitted or received power The capacity of CDMA2000 1x system is considered to be limited by the forward link capacity Different rate data traffic requires different transmitted power and rate controlling enables the system utilize radio resource more efficiently. A very simple rate control algorithm for data calls in CDMA2000 1x system is proposed. In the proposed algorithm, by monitoring the total transmit power, we can simply adjust data rate to channel conditions and efficiently use radio resources. The proposed algorithm is easy to implement in power controlled CDMA systems.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.332-333
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• 2011

본 논문에서는 15V, 1kW 저전압 연료전지를 위한 고효율 전력변환장치를 제안한다. DC-DC 컨버터로는 15V에서 380V로의 고승압에 적합한 입력병렬 출력직렬 부스트 하프브리지를 제안하였는데 이는 전부하영역에서 ZVS 턴온으로 96%의 최고 효율을 달성하였다. 또한 DC-AC 인버터부는 상용전원으로의 변환 및 DC 링크 전압 제어를 수행한다. 1kW급 시작품을 제작하여 그 성능을 검증하였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.446_447
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• 2009

This paper describes operational analysis results of the DC micro-grid using detailed model of distributed generation. Detailed model of wind power generation, photo-voltaic generation, fuel-cell generation was implemented with the user-defined model of PSCAD/EMTDC software that is coded with C-language. Various simulation results confirm that the DC micro-grid can operate without any problem in both the interconnected mode and the islanded mode. The operation analysis result confirms that the DC micro-grid make it feasible to provide power to the load stably.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1972_1973
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• 2009

한의학에서는 사상체질(태양인, 태음인, 소양인, 소음인) 구분을 위해 손등피부의 특징 중 하나인 거침/미끄러움을 이용하여 한의사의 주관적인 판단으로 사상체질을 구분해 왔다. 한의사의 손등피부 거칠기의 주관적인 촉진을 정량적 및 객관적으로 진단하기 위하여 피부마찰력진단기기를 개발하였다. 피부마찰력진단기기는 3축 로드셀 센서를 이용하여 한의사가 손등피부를 만지는 것과 같은 움직임으로 측정하며, 측정된 물리량 중 피부의 거침/미끄러움으로 계산되는 운동마찰계수 값을 이용하여 손등피부의 특성을 나타내었다. 본 연구에서는 피부마찰력 진단기기를 이용하여 객관적으로 손등피부의 특성을 측정해 보고 사상체질 진단의 객관적인 지표를 찾는 것을 목표로 한다.