• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.3
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• pp.259-264
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• 2014

This paper is research paper on the MPD(Magnet Position Device) for the outdoor MGV(Magnet /Magnet Gyro Guidance Vehicle). Usually, MGV is used in indoor environment because of a measurement height of the magnet position device. CMPD(Commercial magnet position device) has 30 mm measurement height, so this is suitable structure in indoor environment like to a flat surface. Outdoor environment is an uneven and irregular, So Outdoor MGV must has a suspension. But CMPD is unsuitable for outdoor environment because of a collision with a surface caused by suspension. Thus, measurement height of the outdoor MPD is positively necessary more than 100 mm. So, we suggest the outdoor MPD using analog magnet hall sensor, moving average filter and Characteristic(rate of the magnet hall sensor) function of the localization. Result of the experiments, the proposed Magnet Position Device for the outdoor MGV has localization accuracy 4.31 mm, measurement height 150 mm and width 150 mm and is efficient more than CMPD.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.487-489
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• 2016

In this paper, quad copter provides a method for preventing the possibility of accident in the air during a formation flight. The existing studies had a few studies upon the falls because quad copter formation flight was generally implemented indoors. Therefore, in this paper, we provide a self-diagnosis system to prevent a secondary accident for mismatching the Proportional-Integral-Derivative(PID) and detecting an abnormal communication modules each others in formation flying system. Scheme to be proposed, a system is that when one of the node meets a problem, the header node is sending the information of the current state to the server in the first and making a diagnosis itself in order to avoid the problems caused by dropping from the air. Therefore, if the difference between PID value of header node and slave node is greater than specified values or if it detects a defective sensors and communication modules, the proposed system is set to provide for moving toward a safe place. As a result, we expect that this proposed system is possible to minimize additional incidents by self adjusting the height through a self-diagnosis discovering flawed the acceleration sensor, gyro sensor and various attached sensors.

• Journal of Biomedical Engineering Research
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• v.33 no.1
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• pp.47-52
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• 2012

The purpose of this study is to investigate whether medication and deep brain stimulation (DBS) have differential effects on the speed and amplitude of bradykinesia in patients with Parkinson's disease (PD). Five PD patients with implanted DBS electrodes (age: $60.6{\pm}7.4yrs$, H&Y stage: $3.1{\pm}0.2$) participated in this study. FT (finger tapping) movement was measured using a gyrosensor system in four treatment conditions: Med (Medication)-off/DBS-off, Med-off/DBS-on, Med-on/DBS-off and Med-on/DBS-on. Quantitative measures representing average speed and amplitude of FT movement included root-mean-squared (RMS) angular velocity and RMS angle. One-way repeated measures ANOVA showed that RMS angular velocity of Med-on/DBS-on was significantly greater than those of Med-off/DBS-off and Med-off/DBS-on (p < 0.01) whereas RMS angle was not different among conditions (p = 0.06). Two way repeated measures ANOVA showed that only medication improved RMS angular velocity (p < 0.01), whereas both medication and DBS had no significant effect on RMS angle (p > 0.02). Effect size of RMS angular velocity was greater than that of RMS angle in both medication and DBS. This suggests that medication and DBS have differential effects on FT bradykinesia and velocity and amplitude impairments may be associated with different functional aspects in PD.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.6
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• pp.645-651
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• 2012

In this paper, we propose a new method for stabilizing the image captured from a camera mounted on a buoy robot. In this study, in order to solve the problem of cumulative errors and noise produced by a general gyro sensor measuring the orientation angle of the buoy robot, we propose new method for stabilizing the image. In this method, image processing techniques are combined with a newly designed target mounting mechanism that adapts to wave fluctuations. New target extraction and angle estimation techniques are introduced, along with the new mounting mechanism used for the camera and the target, which produce a stabilized image even if the buoy robot is on fluctuating waves.

• Journal of Biosystems Engineering
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• v.36 no.2
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• pp.116-121
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• 2011

This study was conducted to develop a robust navigator which could be in positioning for precision farming through developing a plural GPS receiver with 4 sets of GPS antenna. In order to improve positioning accuracy by integrating GPS signals received simultaneously, the algorithm for processing plural GPS signal effectively was designed. Performance of the algorithm was tested using a simulation program and a fixed point on WGS 84 coordinates. Results of this study are aummarized as followings. 1. 4 sets of lower grade GPS receiver and signals were integrated by kalman filter algorithm and geometric algorithm to increase positioning accuracy of the data. 2. Prototype was composed of 4 sets of GPS receiver and INS components. All Star which manufactured by CMC, gyro compass made by KVH, ground speed sensor and integration S/W based on RTOS(Real Time Operating System)were used. 3. Integration algorithm was simulated by developed program which could generate random position error less then 10 m and tested with the prototype at a fixed position. 4. When navigation data was integrated by geometrical correction and kalman filter algorithm, estimated positioning erros were less then 0.6 m and 1.0 m respectively in simulation and fixed position tests.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.674-677
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• 2010

The purpose of this study was to analyze bradykinesia of forearm movement in patients with Parkinson's disease (PD) as compared to those of normal subjects. A gyrosensor was selected for the measurement of forearm movement, because it can provide angular velocity signal which is free from the gravitational artifact and also because it can be conveniently used during clinical test of bradykinesia. Forty PD patients (age: $65.7\pm11.1$ yrs, H&Y stage:$2.3\pm0.5$), 14 age-matched elderly subjects ($65\pm3.9$ yrs) and 17 healthy young subjects ($24\pm2.1$ yrs) participated in this study. Angular velocity during forearm movement of pronation/supination was measured in both arms. Suggested quantitative measures of bradykinesia were root-mean-squared (RMS) angular velocity, RMS angle, peak power and total power which were derived from the angular velocity. ANOVA showed that all measures were significantly different among three groups (p<0.001). Subsequent post-hoc test revealed that all measures in PD patients were significantly smaller than in healthy elderly and healthy young subjects (p<0.05). This results suggest that PD patients can be differentiated from normal subjects using suggested measures.

• Journal of Biomedical Engineering Research
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• v.30 no.2
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• pp.142-146
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• 2009

The purpose of this study is to investigate the angular velocity of forearm pronation/supination movement in Parkinson's disease patients, as a quantitative measure of the bradykinesia. Thirteen Parkinson's disease patients ($64{\pm}11.0$ yrs, male:6, female:7) participated in the experiments. The subjects' both right and left forearms were scored by a rater according to rapid alternating movement of hands category in the UPDRS (unified Parkinson's disease rating scale) and the angular velocity of forearm pronation/supination was measured at the same time. As analysis parameters, RMS (root mean square) angular velocity and RMS angle were used. The parameters showed negative correlation with the clinical score (RMS angular velocity: r= - 0.914, RMS angle: r= -0.749). The RMS angular velocity of all clinical scales were significantly different one another except for the non significant difference between those of scale 3 and 4. RMS angle of scale 0 was significantly different from those of scale 2, 3, 4 and that of scale 1 was significantly different from those of scale 3 and 4. This suggests that RMS angular velocity can be used for a quantitative measure of bradykinesia in motor examination.

• Journal of Biomedical Engineering Research
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• v.31 no.3
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• pp.240-244
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• 2010

The purpose of this study is to compare finger tapping (FT) movement of patients with Parkinson's disease (PD) with normal subjects. A gyrosensor system was used for the measurement of FT movement, because it provides angular velocity free from the gravitational artifact and it can be used during clinical FT test listed in unified PD rating scale (UPDRS). Forty PD patients (age: 65.7 ${\pm}$ 11.1 yrs, H&Y stage:2.3 ${\pm}$ 0.5), 14 age-matched elderly subjects (65${\pm}$3.9 yrs) and 17 healthy young subjects (24${\pm}$2.1yrs) participated in this study. Angular velocity of finger tapping movement was measured in both right and left index finger. As quantitative measures, root-mean-squared (RMS) angular velocity, RMS angle, peak power and total power were used. ANOVA showed that all measures were significantly different among three groups (p<0.001) in all quantitative measures. Post-hoc test revealed that all quantitative measures except peak power in patients with PD were significantly smaller than in both healthy elderly and young subjects (p<0.01). This suggests that the measures developed in this study can distinguish patients with PD from normal subjects.

• Journal of the Korea Convergence Society
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• v.11 no.11
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• pp.195-201
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• 2020

This paper implemented quadcopter-type drone system and proposed the heuristic method for obtaining the optimum gain coefficients in order to minimize the settling time. Control system for quadcopter posture stabilization reads the posture data from accelerator and gyro sensor, revises the original posture data using Mahony filter, and drives 4 DC motors using PID controller. The first step of the proposed method is to obtain the gain coefficients using the Ziegler-Nichols method, and then determine the optimum gain coefficients using the heuristic method at the next 3 steps. The experimental result shows that the maximum overshoot decreases from 44.3 to 29.8 degrees and the settling time decreases from 2.6 to 1.7 seconds compared to the Ziegler-Nichols method. Therefore, we proved that the proposed method works well in quadcopter flight system with high motor noise while reducing trial and error to obtain the optimal PID gain coefficients.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.1
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• pp.51-56
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• 2013

In order to apply a biped robot in real world, the robot requires a robust walking and a function of localization, path planning and navigation. Recently, localization and path planning using RFID of mobile robot has been studying. However, when the biped robot walks, it has unstability and tends to leave the path. In the paper we propose a method of walking stabilization using FSR(Force Sensing Resistor), Gyro and accelerometer for the real biped robot. Also a path tracking algorithm using RFID sensor attached in robot's foot is proposed based on localization of the robot. The proposed algorithm is verified from walking experiments using real biped robot on uneven terrain and path tracking experiments on the RFID environments.