• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.439-439
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• 2000

In this paper, the relationship among the vertical acceleration, measuring points and walking patterns is analyzed. To measure acceleration, the acceleration measurement unit and communication board is constructed. It uses MEMS accelerometer ADXL-202 that detects 2-axis acceleration simultaneously. It is shown by the experiment test that the walking pattern is recognized and walking step is detected at easy when acceleration measurement unit is mounted on leg.. This results can be directly utilized in designing the personal navigation system with low-cost inertial sensor.

• 한국과학교육학회지
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• 제27권5호
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• pp.421-431
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• 2007

본 연구의 목적은 우리나라 3학년부터 10학년까지의 과학교과서에 나타난 기초탐구과정 중 관찰과 측정이 어떻게 제시되어 있는지 알아보는 것이다. 분석결과는 다음과 같다. 관찰에서는 시각을 많이 사용하고, 고학년으로 올라가면서 관찰의 수준이 높아져 '단순관찰'에서 '비교하며 관찰하기'의 수가 증가하였고, 언어표현보다 글표현 방식이 증가하였다. 측정대상은 온도측정이 가장 많았고, 저학년에서 고학년보다 측정 설계가 많이 발견되었다. 측정도구의 사용법은 학년에 맞게 계획적으로 제시되지 않고 교과서의 탐구활동에서 관련된 측정도구가 제시될 때 설명되어 학생들이 측정방볍을 체계적으로 학습하지 못하도록 되어 있었다. 학년이 올라가면서 정성적 측정에서 정량적 측정이 많아졌으며, 단순측정보다 조작측정의 수가 급격하게 증가하였다. 측정결과의 활용에서는 단위사용, 단위변환, 유효 숫자처리, 오차와 불확실도 등에 대한 내용은 거의 제시되지 않는 문제점이 발견되었다.

• 한국운동역학회지
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• 제25권1호
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• pp.123-130
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• 2015

Purpose : The purpose of this study was to investigate the reliability of 3D-inertia measurement unit (IMU) based shoes in gait analysis. This was done with respect to the results of the optical motion capturing system and to collect reference gait data of healthy subjects with this device. Methods : The Smart Balance$^{(R)}$ system of 3D-IMU based shoes and Osprey$^{(R)}$ motion capturing cameras were used to collect motion data simultaneously. Forty four healthy subjects consisting of individuals in 20s (N=20), 40s (N=13), and 60s (N=11) participated in this study voluntarily. They performed natural walking on a treadmill for one minute at 4 different target speeds (3, 4, 5, 6 km/h), respectively. Results : Cadence (ICC=.998), step length (ICC=.970), stance phase (ICC=.845), and double-support phase (ICC=.684) from 3D-IMU based shoes were in agreement with results of optical motion system. Gait data of healthy subjects according to different treadmill speeds and ages were matched to previous literature showing increased cadence and reduced step length for elderly subjects. Conclusion : Conclusively, 3D-IMU based shoes in gait analysis were a satisfactory alternative option in measuring linear gait parameters.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1995년도 춘계학술대회 논문집
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• pp.1-8
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• 1995

This paper proposed a simple method for measuring surface roughness of ground surface. utilizing non-contact in-process measuring system using the diode laser. The measurement system is consisted of a laser unit with a diode laser and a cylindrical lens a detecting unit with polygon mirror and CCD array sensor. and a signal processing unit with a computer and device. During operation, this measuring system can provide information on surface roughness in the measuring distance with a single sampling and simultanilusly monitor the state of the grind wheel. The experimental results, showed that the increase of the feed rate and the dressing speed an caused increase in the surface roughness and when the surface roughness is 4Rmax-10Rmax, the cutting speed is 1653m/min-1665m/min. the feed rate is 0.2m/min-0.9m/min, the dressing speed is 0.2mm/rev-0.4mm/rev, the stylus method and the in-process method can be obtained the same results. thus under limited working conditions. using the proposed system. the surface roughness of the ground surface during cylindrical grinding can be obtained through the in-process measurement method using the diode laser.

• Journal of Electrical Engineering and Technology
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• 제12권3호
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• pp.996-1006
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• 2017

Phasor Measurement Unit (PMU) placement is a crucial problem for State Estimation (SE) of the power system, which can ensure that the power network is fully observed. Further, the observation reliability problem of the system has been concerned in the operation conditions. In this paper, based on modified weighted adjacent matrix ($A_w$), an optimal placement method is proposed to solve simultaneously two problems involving the optimal PMU placement problem and the observation reliability enhancement problem of the system. The purpose of the proposed method is to achieve both the minimum total cost and the maximum observation reliability, with a focus on increasing the security of observability, strengthening the observation reliability of buses as well as enhancing the effectiveness of redundancy. Simulations on IEEE 14, 24, 30 and 57 bus test systems are presented to justify the methodology. The results of this study show that the proposed method is not only ensuring the power network having the observability effectively but also enhancing significantly the observation reliability. Therefore, it can be a useful tool for SE of the power system.

• 한국안전학회지
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• 제10권3호
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• pp.30-41
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• 1995

This paper proposed a simple method for measuring surface roughness of ground surface. Utilizing non-contact in-process measuring system using the diode laser. The measurement system is consisted of a laser unit with a diode laser and a cylindrical lens, a detecting unit with polygon mirror and CCD array sensor, and a signal processing unit with a computer and device. During operation, this measuring system can provide information on surface roughness in the measuring distance with a single sampling and simultaniously monitor the state of the grind wheel. The experimental results, showed that the Increase of the feed rate and the dressing speed an caused increase in the surface roughness and when the surface roughness is 4Rmax-10Rmax, the cutting speed is 1653m/min-1665m/min, the table speed is 0.2n1/min -0.9m/min, the dressing speed is 0.2mm/rev～0.4mm/rev, the stylus method and the in-process method can be obtained the same results. Thus, under limited working conditions, using the proposed system, the surface roughness of the ground surface during cylindrical grinding can be obtained through the in-process measurement method using the diode laser.

• 항공우주시스템공학회지
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• 제16권5호
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• pp.94-101
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• 2022

본 논문에서는 해외수출용 유도무기체계에 탑재되는 MEMS 관성측정기의 특성과 탑재되는 유도무기체계의 운용 환경 분석을 통해서 신뢰성 입증을 위한 관성측정기 가속계수를 도출하고, 이를 기반으로 관성측정기 수명 시험을 설계하였다. 또한 설계된 수명 시험을 토대로 관성측정기 3조에 대한 수명 시험 수행을 통해 12년의 목표 수명을 입증하였다.

• Journal of Oral Medicine and Pain
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• 제48권4호
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• pp.144-151
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• 2023

Purpose: The aim of this study was to assess the repeatability of the electrical measurement of taste detection on different dates and in different sessions in healthy young females. Methods: The sites of electrical stimulation were the tip of the tongue, the posterolateral border of the tongue and the soft palate on the right side unilaterally. The measurements were repeated over three consecutive days, three sessions per day and three times for each session in seventeen healthy females. The repeatability of the measurement was assessed by the intraclass correlation coefficient (ICC). Results: In the dB unit, the ICC of the tip of the tongue and the soft palate was good (61.03 and 66.03, respectively); however, the lateral border of the tongue was a little lower (58.07). In the ㎂ unit, all three test sites had poor ICC. Variability was more significantly associated with the subject factor than with other factors such as trials, sessions and days in dB and ㎂ units. Conclusions: Electrogustometry, which measures electrical taste detection thresholds in the dB unit, is repeatable and acceptable for clinical use in assessing taste function in healthy young females.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.450-453
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• 2003

건선 사업에 일어서 초기 계획과 기성의 주기적이고 반복적인 비교 검토는 매우 중요하다. 이를 위해서는 정확한 현장 실적자료가 제공되어야하고, 작업량을 객관적으로 계량화하는 기준 및 진행상황을 정확히 반영한 진도율 산정이 필요하다. 이러한 진도율 산정을 위해서는 전체 사업이 명확한 작업범위를 갖는 단위작업으로 분할되어, 각 단위 작업에 필요한 정보가 할당되어야 한다. 국내 건설 사업에서와 같이 내역중심의 사업관리가 이루어지고 있는 상황하에서는 각 단위작업의 물량, 공사비 둥을 포함한 비용 정보 뿐만 아니라 일정 정보를 반영한 진도율 산정 방법이 필수적이며, 본 연구에서는 두 가지 정보에 의한 가중 진도율 산정방법을 제시하고자 한다.

• 한국해양공학회지
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• 제17권6호
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• pp.83-90
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• 2003

This paper presents an underwater hybrid navigation system for a semi-autonomous underwater vehicle (SAUV). The navigation system consists of an inertial measurement unit (IMU), and a Doppler velocity log (DVL), accompanied by a magnetic compass. The errors of inertial measurement units increase with time, due to the bias errors of gyros and accelerometers. A navigational system model is derived, to include the scale effect and bias errors of the DVL, of which the state equation composed of the navigation states and sensor parameters is 20. The conventional extended Kalman filter was used to propagate the error covariance, update the measurement errors, and correct the state equation when the measurements are available. Simulation was performed with the 6-d.o,f equations of motion of SAUV, using a lawn-mowing survey mode. The hybrid underwater navigation system shows good tracking performance, by updating the error covariance and correcting the system's states with the measurement errors from a DVL, a magnetic compass, and a depth sensor. The error of the estimated position still slowly drifts in the horizontal plane, about 3.5m for 500 seconds, which could be eliminated with the help of additional USBL information.