• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.415-420
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• 2012

This paper proposes a novel type of tactile device utilizing magnetorheological (MR) fluid which can be applicable for haptic master of minimally invasive surgery (MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field (or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.31-32
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• 2007

This paper is concerned with design methodology of gateway using IEEE 802.15.4 for DeviceNet. Wireless gateway is composed of DeviceNet master and IEEE 802.15.4 coordinator and node devices. The test results show the availability of implemented gateway.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.579-581
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• 2004

We wish to develop micro-total analysis system (TAS) on a chip, and to make a trial approach to solve the important problem that is to detect ions separated by the electric field. We propose an idea, which is as for rotational motions of dipolar ions, which are affected by the ion atmosphere in outer regions. This is a new kind of the ion-sensitive field effect transistor (ISFET). We wish to develop the ISFET chips, and give more effective, fast and sensitive, capillary electrophoresis is designed in near future.

• 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.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.237-239
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• 2005

In this paper PLC Power Circuit with Hot-Swap Function is proposed for stable power supplies. The power modules of the proposed devices are implemented by CRM flyback converter using new synchronous rectifier circuit for high efficiency. By a variable switching frequency controller, this converter is operated with a reduced turn-on switching loss. Also, the load current in these power modules are shared by auto master / slave method using Outer loop. The proposed devices are analyzed in detail and optimized for high performance. Experimental results for a 100W power module at the variable switching frequency of 30$^{\sim}$70kHz were obtained to show the performance of the proposed device.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.100.6-100
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• 2002

The crane and the master-slave manipulators (MSM) are widely used as a remote handling device in nuclear facilities such as the hot cell. The equipment to be installed in the hot cell should be optimally placed within the workspace of the wall-mounted slave manipulator for the maintenance operation. Also, the slave manipulator with the end effectors should be properly positioned and oriented for the dedicated maintenance operation. Hence, the workspace and the motion of the slave manipulator, as well as, the remote operation task should be analyzed before installing the manipulators and the hot cell equipment. For this purpose, the 3D graphic simulator, which simulates the remote operation o...

• Journal of the Korean Institute of Telematics and Electronics
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• v.14 no.5
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• pp.1-6
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• 1977

When the input of synchronizer which is used for the purpose of synchronizing the master clock of computer with the interrupt system, a sort of random variable device, is gated with asynchronous intersection of the fall time of the master clock and the risetime oi the interrupt request, synchronizer is drived in Metastable region. This paper is presented circuit analysis of Metastable phenomena and analysis for transient process from metastable point to stable state, and also realities the collect logic with Inverter and open collector methods with a view to improving logic failure caused by the mishappen phenomena.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.394-401
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• 2003

We consider a PCB grouping problem arising from the electronic industry. Given a surface mounting device, several types of PCBs and a number of component feeders used to assemble the PCBs. the optimization problem is the PCB grouping problem while minimizing setup time of component feeders. We formulate the problem as an Integer programming model and propose a column generation approach to solve the Integer programming formulation. In this approach we decompose the original problem Into master problem and column generation subproblem Starting with a few columns in the master problem. we generate new columns successively by solving subproblem optimally. To solve the subproblem. we use a branrh-and-rut approach. Computational experiments show that our solution approach gives high quality solutions in a reasonable computing time.

• Journal of the Korean Operations Research and Management Science Society
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• v.11 no.2
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• pp.37-50
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• 1986

In combining dispersed optimization models, either primal or dual(or both) decomposition method widely used as an organizing device. Interpreting the methods economically, the concepts of price and resource-directive coordination are generally well accepted. Most of deomposition/ integration methods utilize either primal information of dual information, not both, from subsystems, while some authors have developed mixed decomposition approaches employing two master problems dealing primal and dual proposals separately. In this paper a hybrid decomposition method is introduced, where one hybrid master problem utilizes the underlying relationships between primal and dual information from each subsystem. The suggested method is well justified with respect to the flexibility in information flow pattern choice (some prices and other quantities) and to the compatibility of subdivision's optimum to the systemwide optimum, that is often lacking in conventional decomposition methods such as Dantzig-Wolfe's. A numerical example is also presented to illustrate the suggested approach.

• Korean Journal of Acupuncture
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• v.21 no.2
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• pp.1-28
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• 2004

Objectives : Human physiological changes in the state of qigong has been measured using EEG(Electroencephalography), functional MRI(functional Magnetic Resonance Image), EAV(Electro-Acupuncture according to Voll) and SQUID(Superconducting Quantum Interference Device) measurements. Methods & Results : EEGs were measured to study the differences between Qigong masters and Qi receiver on the changes of EEG. During Qigong, an alpha waves were increased. The power spectra indicate that the peak frequency of alpha waves increased during Qigong. Qi receiver's EEG signals seemed to affected by the state of himself. Brain activation did not observed when qigong master concentrates the Qi at Laogong(P8). But a localization of fMRI signal in the sensory cortex was observed by electric acupuncture stimulation at Laogong(P8). Five phase deviation of EAV were clearly changed in the both cases of Qigong master and Qi receiver. When a Qigong master concentrates the Qi at Yintang, Laogong(P8), Qihai(CV6) meridian points during Qigong state, the change of magnetic field around acupoints Yintang, Laogong points has been measured using 40-Channel DROS-SQUID apparatus. After smoothing process of the continuously measured magnetic signal around acupoints for a few minutes, we could observe that a series of peaks, magnitude of -1.0~2.5pT appeared. But there was no significant difference in changes of magnetic signal around acupoints. Physical signals of magnetocardiogram has been measured by using 2-Channel DROS SQUID(Magnetocardiogram). Physical signals of magnetocardiogram were clealy changed at the ST segments after S-wave when qigong master concentrates the Qi.