• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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• pp.507-512
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• 1999

In modern engineering practice, the grinding process is one of the most important and widely used operations for the precision finishing of components. In this paper, machining characteristics of external plunge grinding were investigated by using spindle motor current signal through hall sensor. Grinding experiments were performed in terms of various grinding conditions such as wheel speed, workpiece speed, infeed rate and spark-out time with conventional vitrified bonded WA wheel. The relationship between spindle motor current signal and metal removal rate in terms of infeed rate was induced the by analyzing spindle motor current signal.

• 한국정보통신학회논문지
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• 제16권7호
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• pp.1549-1558
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• 2012

위치 인식 시스템은 물류, 의료, 홈 네트워크, 군사, 교통 시스템 등 다양한 분야에서 활용된다. 본 논문에서는 무선 RF만으로 정밀한 위치 인식이 가능한 IEEE802.15.4a의 CSS(Chirp Spread Spectrum)방식을 기반으로 다양한 환경에서 사용할 수 있는 위치인식 시스템을 설계하였다. 실험 결과 20m의 반경을 가지는 공간에서 0.5m 미만의 오차범위를 가지는 위치 인식 시스템을 구현하였다.

• International Journal of Aeronautical and Space Sciences
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• 제1권2호
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• pp.50-67
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• 2000

The spacecraft simulator is used for command validation, operational check of the Satellite Operation Subsystem (SOS), spacecraft anomaly analysis support, satellite operator training etc. In this paper, S/W design features and modeling characteristics of the KOMPSAT Spacecraft Simulator Subsystem (SIM) are described. Validation procedures and simulation results are also provided. The SIM provides extensive simulation capabilities by including models for most of the spacecraft subsystems. The software structure of the SIM was designed and implemented so as to support operations not only in real-time but also in non real-time by utilizing the Hewlett Packard (HP) UNIX functions. The SIM incorporates as many user-friendly Man Machine Interface (MMI) windows as possible so that all the SIM normal operations can be executed through the MMI windows.

• 센서학회지
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• 제16권4호
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• pp.263-269
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• 2007

Although variable resistance displacement transducer is widely applied for its technical simplicity, electrical point contact limits measurement resolution (precision). The present study introduced roller shaped structure for electrical line contact. Proto-type transducer was developed and measurement characteristics were compared with a commercialized product. When the displacement was varied with steps of 5 mm, 1 mm, and down to 0.1 mm, the correlation coefficient between resistance and displacement decreased lower than 0.9 in the commercialized product while the proto-type transducer maintained values higher than 0.99. Therefore, the measurement resolution was enhanced by approximately 10 times. Since manufacturing also seemed easier, the present results would enable more accurate and less expensive manufacturing of variable resistance displacement transducer.

• 한국생산제조학회지
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• 제23권6호
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• pp.630-635
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• 2014

This study aims to develop a PZT-driven depth adjustment device with a flexure hinge and to investigate its static/dynamic characteristics. This device will be applied to rapidly and accurately trace a flat surface with slight waviness of up to several hundreds of micrometers in magnitude. One typical example is to cut a film coated on a steel plate. A depth control system composed of PMAC, PZT/PZT amplifier, flexure hinge/knife, and laser displacement sensor is implemented on a desktop three-axis machine and an actual cutting test is conducted on a steel workpiece with a sinusoidal-wavy surface. It is verified that the dynamic characteristics of the device limit the maximum cutting speed and depth precision.

• 대한임상검사과학회지
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• 제38권1호
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• pp.59-64
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• 2006

The pH-ISE(ion selective electrode) based on tribenzylamine as a hydrogen ion carrier was prepared and its electrochemical characterization was studied. It responded linearly to hydrogen ions in the range of pH 3.1 - pH 11.0 and the Nernstian slope showed 55.0 mV/pH (at $20{\pm}0.2^{\circ}C$), it also showed a fast response time of 8 sec. When it was directly applied to human blood(pH 6.0-8.5), we could get the same satisfying results. A good reproducibility and stability were shown with the precision of 2 mV (${\pm}0.1$). The pH-ISE based on tribenzylamine exhibited biocompatibility in clinical applications.

• 한국측량학회지
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• 제19권1호
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• pp.47-53
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• 2001

본 연구에서는 수치근접사진측량기법을 이용, 교량의 안전진단을 위한 변위를 측정하고자 하였다. 이에 재하 경우별로 디지털 카메라와 CCD카메라에 의한 동기영상을 획득, 분석하고 이를 동일조건에서 계측센서 및 정밀레벨에 의한 수직변위와 필름기반 영상해석 결과값과도 비교.분석을 수행하였다. 그 결과, 최대 0.83mm 편차내의 근접한 변위성과를 도출하므로써 교량의 거동측정 및 안전진단에 그 적용 가능성을 확인 할 수 있었다.

• International Journal of Aeronautical and Space Sciences
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• 제5권1호
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• pp.83-93
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• 2004

A new alignment calibration method of attitude sensors for the precisionattitude determination of a spacecraft based on the extended Kalman filter is proposed.The proposed method is divided into two steps connected in series: the gyro and thestar tracker calibration. For gyro calibration, alignment errors and scale factor errorsare estimated during the calibration maneuver under the assumption of a perfect startracker. Estimation of the alignment errors of the star trackers and compensation ofthe gyro calibration errors are then performed using the measurements includingpayload information. Performance of the proposed method are demonstrated bynumerical simulations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권12호
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• pp.6063-6079
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• 2019

When the length of sampling data sequence is too large, the method of gesture recognition based on traditional Dynamic Time Warping (DTW) algorithm will lead to too long calculation time, and the accuracy of recognition result is not high.Support vector machine (SVM) has some shortcomings in precision, Edit Distance on Real Sequences(EDR) algorithm does not guarantee that noise suppression will not suppress effective data.A new method based on Improved Interpolation Dynamic Time Warping (IIDTW)algorithm is proposed to improve the efficiency of gesture recognition and the accuracy of gesture recognition. The results show that the computational efficiency of IIDTW algorithm is more than twice that of SVM-DTW algorithm, the error acceptance rate is FAR reduced by 0.01%, and the error rejection rate FRR is reduced by 0.5%.Gesture recognition based on IIDTW algorithm can achieve better recognition status. If it is applied to unlock mobile phone, it is expected to become a new generation of unlock mode.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.523-526
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• 1987

The present metering transformer being used for measurement has the characteristics of high reliability and high efficiency. In the future, however, it is thought that the scales of mettering transformer will be larger and the cost of production will increase as the transmission voltage ascends to UHV. And, also, it wilt be not easy to ensure the aseismatic capability. For the purpose of settling these problems, by applying optical sensor technology to electric power systems and by developing optical current transformer and potential transformer, we will realize the saving in energy, reduction of cost prise, improvement in measuring precision.