• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2665-2667
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• 2004

This paper presents a study of a position finding system for a reactor inspection robot. The position of PSD(Position Sensitive Detector) sensor is calculated by the degree of pan-tilt and the difference in height between pan-tilt and PSD. For that, the DSP which control pan-tilt is used for precise operation and the PIC microcontroller process PSD sensor data that indicate light incident position. A user using computer can acquire the conditions of pan-tilt and PSD.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.7
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• pp.656-663
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• 2007

A new dynamic balancing algorithm has been proposed to minimize the number of sensors necessary for the horizontal balancing of the mobile inverted pendulum while maintaining the same level of the commercial performance. The inverted pendulum technique is getting attention and there have been many researches on the Segway since the US inventor Dean Kamen commercialized. One of the major problems of the Segway is that many sensors are required for the control of the Segway, which results in the high price. In this research, a single gyro and a tilt sensor are fused to obtain the absolute tilt information, which is applied for the control of the mobile inverted pendulum. A dynamic balancing technique has been developed and applied for a robust control system against disturbances. The intelligent handling and stable curving of the Segway as a next generation mobile tool are verified with a human loading.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.404-408
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• 2009

Gas pipelines in bridges, roads and subway construction sections can undergo abrupt stress and vibration changes. To protect human life from any gas leakage accidents induced by the abrupt stress and vibration, the gas pipeline system needs to be continuously monitored. The estimation method of pipeline stress using MEMS wireless tilt sensor has been developed and its validity has been evaluated using a lab test bench.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.339-341
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• 2006

This paper proposes a method of container position measurement using automatic landing system that is estimated by a laser range finder. In the most of container position measurement methods, CCD cameras or laser scanners have been used to get the source data. However those sensors are not only weak for disturbances, for examples, the light, fog, and rain, but also the system cost is high. When the spreader arrives the goal position, it is still swung by inertia or by wind effect. In this paper, the spreader swung data have been used to find the container position. The laser range finder is equipped in the front side of spreader. It can measure distance and relative position between spreader and container. This laser range finder can be rotated as desired by a motor. And a tilt sensor is equipped on the spreader to measure spreader sway. We estimate the relative position information between the spreader and a container using the laser range finder and tilt sensor through the geometrical analysis.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.4
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• pp.19-24
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• 2013

The problem of elderly people with weak physical health has become a very important issue in the aging society. Elderly people with very low judgment and decision-making skills often falls because of the degradation of the strength and balance. Due to the fall triggered off fractures, parenchyma damage, and casualties, generally fast emergency treatment is needed. In this paper, an automatic fall detection system consisting of a triaxial accelerometer and tilt sensor. Using the fall system, the performance of the system was analyzed in many situations. The experimental results showed more than 92% analytical skills.

• PNF and Movement
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• v.20 no.2
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• pp.215-222
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• 2022

Purpose: The purpose of this study was to compare the effects of passive scapular upward rotation and posterior tilt and active scapular posterior tilt on the muscle activity of the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA). Methods: Fifteen healthy subjects performed general arm elevation, arm elevation with passive scapular upward rotation and posterior tilt, and arm elevation with active scapular posterior tilt. For active scapular posterior tilt, the subjects were trained in this movement using visual biofeedback and a motion sensor. During each arm elevation condition, electromyography was used to measure the muscle activity of the UT, LT, and SA. The measured data were analyzed using a one-way repeated ANOVA. Results: LT muscle activity was significantly increased during arm elevation with active scapular posterior tilt compared to both general arm elevation and arm elevation with passive scapular upward rotation and posterior tilt (p < 0.05). SA muscle activity was greater during arm elevation with passive scapular upward rotation and posterior tilt than during general arm elevation (p < 0.05). There was no significant change in UT muscle activity among the tested arm elevation conditions (p > 0.05). Conclusion: Performing arm elevation with active scapular posterior tilt and performing arm elevation with passive scapular upward rotation and posterior tilt may be useful strategies for increasing muscle activation of the LT and SA, respectively.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.116-124
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• 2011

In this study, a new method to estimate the bridge deflection is developed by using Wireless Tilt Sensor. Most of evaluations of structural integrity, it is very important to measure the geometric profile, which is a major factor representing the global behavior of civil structure, especially bridges. In the past, Because of the lack of appropriate methods to measure the deflection curve of bridges on site, the measurement of deflection had been done restrictly within just a few discrete points along the bridge. Also the measurement point could be limited to locations installed with displacement transducers. So, in this study, the deflection of the structure was measured by wireless tilt sensor instead of LVDT(Linear Variable Differential Transformer). Angle change of tilt sensor shows structural behavior by the change of the resistor values which is presented to voltage. Moreover, the maximum deflection was calculated by changing the deflection angle which was calculated as V(measured voltage) ${\times}$F(factor) to deflection. The experimental tests were carried out to verify the developed deflection estimation techniques. Because the base of tilt measuring is the gravity, uniform measurement is possible independent of a measuring point. Also, measuring values were showed very high accuracy.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.219.2-219.2
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• 2012

We are developing Adaptive Optics (AO) system for 24 inch telescope at Seoul National University Observatory. It consists of the tip-tilt correction system and the residual wavefront error correction system with a deformable mirror and a wavefront sensor. We present the construction and performance measurements of the tip-tilt correction system. The tip-tilt component is the single largest contributor to wavefront error, especially for small telescope. The tip-tilt correction system consists of a quadrant photodiode, a tip-tilt mirror and a feed back loop. The collimated He-Ne laser beam is used for input light source and is artificially disturbed by air turbulence generated by a heat gun. Most of the turbulence is of low frequency less than 20 Hz, but extends to a few hundreds Hz. It is found that the closed loop system using proportional-integral-derivative (PID) control successfully corrects tip-tilt error at a rate as high as 300~400 Hz.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.2
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• pp.141-149
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• 2010

It is essential to find oscillating angles and periods in a seaway when designing and manufacturing stabilizers. It is difficult to find oscillating angles and periods in high speed turning and they vary with ship speed and wave heading angles, therefore, proper algorithm to measure oscillating periods in a seaway. In the present study, three kinds of algorithms are developed to measure oscillating angles periods in a seaway. Dual axis tilt sensor of low price is used to measure oscillating angles, and the effect of lateral accelerations on tilt sensor have been reduced by the fusion algorithm using the gyro sensor signals. Analog and digital filters are applied to minimize the noise of the signals. Three kinds of algorithms, zero crossing, peak to peak and moving zero crossing algorithm, are developed to measure oscillating periods in a seaway. It is found that the moving zero algorithm showed the best results in the sea trials.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.14-21
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• 2004

This automotive headlight control system is newly proposed that, under my slope degree of the driving mad(flat up-hill, and down-hill) at night driving, the reflecting mirror of the headlight can be automatically controlled for safe driving. At first whether or not any vehicle is driven near is checked by photo sensor. Secondly, using the slope degree of the automotive feedbacked from the tilt sensor, the servo motor with the headlight is controlled to be turned right or down to the suitable angle. The servo motor is appropriately controlled according to road conditions. The proposed headlight control system is designed on the basis of the tested illumination intensity obtained according to any slope degree of roads. Finally, it is confirmed that the test model works very well in the given road conditions and environments.