• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.72-77
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• 2006

In this paper, a remote screen control by mobile networks on embedded system is implemented. For this system a server program is ported on the embedded system connected with internet. And on the side of a mobile phone, a client program is ported using GVM. The embedded system can display the text from the mobile phone on its LCD. In the implemented embedded system, the text data from GVM emulator is sent to the system for display on its LCD. The realization of the proposed embedded system can display the text from a working mobile phone.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.72-76
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• 2023

The mobile card system used for mobile access control is connected to the door lock mounted on the door, enabling non-contact control. The RSSI (Received Signal Strength Indicator) of the BLE (Bluetooth Low Energy) communication packet used here can help to know the direction and distance of the mobile device. In this study, the desirable access control distance was calculated and implemented by setting the RSSI of the transmitter of the BLE packet used in mobile access control and processing the RSSI of the receiver.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.737-741
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• 2004

A mobile robot system is developed which is remotely controlled by a haptic master called ‘PHANTOM’. The mobile robot has 4 ultrasonic sensors and single CCD camera which detects the distance from a mobile robot to obstacles in the environment and sends this information to a haptic master. For more convenient remote control, haptic rendering process is performed like viscosity forces and obstacle avoidance forces. In order to show the effectiveness of the developed system, we experiment that the mobile robot runs through the maze and the time is checked to complete the path of the maze with/without the haptic information. Through this repeated experiments, haptic information proves to be useful for remote control of a mobile robot.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.6
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• pp.466-472
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• 2003

This paper describes a tracking control for the mobile robot based on fuzzy systems. Since the mobile robot has the nonholonomic constraints, these constraints should be considered to design a tracking controller for the mobile robot. One of the well-known tracking controllers for the mobile robot is the back-stepping controller. The conventional back-stepping controller includes the dynamics and kinematics of the mobile robot. The conventional back-stepping controller is affected by the derived velocity reference by a kinematic controller. To improve the performance of the conventional back-stepping controller, this paper uses the fuzzy systems known as the nonlinear controller. The new velocity reference for the back-stepping controller is derived through the fuzzy inference. Fuzzy rules are selected for gains of the kinematic controller. The produced velocity reference has properly considered the varying reference trajectories. Simulation results show that the proposed controller is more robust than the conventional back-stepping controller.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.335-338
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• 2005

In this paper, we propose a downlink power control scheme to apply in the unequal error protection multi-code CDMA mobile medicine system. The mobile medicine system contains (i) blood pressure and body temperature measurement value, (ii) ECG medical signals measured by the electrocardiogram device, (iii) mobile patient's history, (iv) G.729 audio signal, MPEG-4 CCD sensor video signal, and JPEG2000 medical image. By the help of the multi-code CDMA spread spectrum communication system with downlink power control scheme and unequal error protection strategy, it is possible to transmit mobile medicine media and meet the quality of service. Numerical analysis and simulation results show that the system is a well transmission platform in mobile medicine.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.381-381
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• 2000

This paper describes the path planning method in an unknown environment for an autonomous mobile robot equipped with CCD(Charge-Coupled Device) camera. The mobile robot moves along the guideline. The CCD camera is useful to detect the existence of a guideline. The wavelet transform is used to find the edge of guideline. Using wavelet transform, we can make an image processing more easily and rapidly. We make a fuzzy control rule using image data then make a decision the position and the navigation of the mobile robot. The center value that indicates the center of guideline is the input of fuzzy logic controller and the steering angle of the mobile robot is the fuzzy output. Some actual experiments for the mobile robot applied fuzzy control show that the mobile robot effectively moves to target position.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.215-221
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• 2010

This paper introduces development of location estimation and navigation system of mobile robots using USN and LEGO Mindstorms NXT. Developed system includes location estimation, location and navigation information display and navigation control parts. It used ZigBee based USN which was built with CC2431 chip to locate blind node and implemented fuzzy model to improve ability of calculation of distances from reference nodes and location of mobile robots. This paper proposed combination method of location estimation using USN and encoder which is built in motors of mobile robots. Experimental results showed proposed method is superior to the method which used USN only in location estimation and navigating robots. Developed system can locate current position of mobile robots and monitor information from sensor nodes like temperature, humidity and send control signal to mobile robot to move.

• Korean Journal of Human Ecology
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• v.24 no.6
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• pp.769-781
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• 2015

The purpose of this study was to examine the effects of self control and social support on the mobile phone dependence in elementary school students. The subjects were 392 children(187 boys, 205 girls) in 5, 6th grade from two elementary schools in Gyeonggi-do. The mobile phone dependence was assessed by the Mobile Phone Dependence Scale(Ko Seong-Ja, 2012), self control was measured by the Self-control Scale(Nam hyeon-mi, 1999) and social support was assessed by the Social Support Scale(Han mi hyun, 1996). Data were analyzed using descriptive statistics, t-test, Pearson correlations and hierarchical regressions. The major results of this study were as follows: First, there was no significant difference in mobile phone dependence by sex of the children. Second, children's mobile phone dependence were correlated with self control and social support. Finally, children's self control, family support and peer support significantly explained the mobile phone dependence. But peer support appeared to have negative corelation on mobile phone dependence, but appeared to have static effect in regression result by suppressor variables. So it needs to explore statistical function of suppressor variables in follow-up studies. Also research of this study indicate that self control enhancement program should be developed and parents should communicate more frankly and affectively with their children in order to prevent children's mobile phone dependence.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.2
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• pp.63-67
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• 2011

This paper presents the mobile robot control based on vision system. The proposed vision based controller consist of the camera tracking controller and the formation controller. Th e camera controller has the adaptive gain based on IBVS. The formation controller which is designed in the sense of the Lyapunov stability follows the leader. Simluation results show that the proposed vision based mobile robot control is validated for indoor mobile robot applications.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.76.2-76
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• 2002

Because of the wheeled mobile robot is modeled by nonlinear system framework and controlled by nonlinear algorithms or fuzzy algorithms, the treatment of wheeled mobile robot is very complecate and conservative. In this paper, a new model of two wheeled mobile robot, which is a type of linear system and treated easily, is presented. And we will show that the control algorithms based on the linear system theory is well work to the wheeled mobile robot by simulation and experiment.