• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.8 no.1
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• pp.59-64
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• 1997

In this Paper, we developed an electrolarynx controlled by the EMG(electromyography) of the sternohyoid muscle, and rested the property of the new electrolarynx while normal persons with his own larynx use it. for the examination of property of the developed electrolarynx, our researchers performed three different experiments. The first experiment was tested whether that on/off control of the vibrator of the electrolarynx is synchronized with the activity of the sternohyoid EMG. In the second experiment, it was tested when the lower amplitude of the sternohyoid EMG is produced, whether the higher pitch of the electrolarynx is produced, and vice versa. The third experiment was tested the probability that the electrolarynx can produce the voiceless sound. As the results, we found that the developed electrolarynx had the good produce of the on/off vibrator control and the pitch control of the electrolarynx. Also, we ascertained the possibility that it can produce the voiceless sound.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.213-218
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• 2003

The equipment of industrial robot in manufacturing and assembly lines has rapidly increased. In order to achieve high productivity and flexibility, it becomes very important to develop the visual feedback control system with Off-Line Programming System(OLPS). We can save much efforts and time in adjusting robots to newly defined workcells by using OLPS. A proposed visual calibration scheme is based on position-based visual feedback. The calibration program firstly generates predicted images of objects in an assumed end-effector position. The process to generate predicted images consists of projection to screen-coordinates, visible range test and construction of simple silhouette figures. Then camera images acquired are compared with predicted ones for updating position and orientation data. Computation of error is very simple because the scheme is based on perspective projection which can be also expanded to experimental results. Computation time can be extremely reduced because the proposed method does not require the precise calculation of tree-dimensional object data and image Jacobian.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.380-384
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• 1992

The position control of a pneumatic cylinder suing low cost on-off valves is studied. The valve control band(VCB) was proposed toget fast response and toprevent solenoid valves from unnecessary switching at the beginning of response. A learning algorithm was used to compensate the nonlinearity and complexity in mathematical modelling of pheumatic on-off controlled positioning systems. In this algorithm, the desired performance index and modified learning rate, were proposed to improvespeed and convergence of learning control. It is shown experimentally that the proposed algorithm is robust to changes of system parameters: the setting time less than 1.0 sec and the error bound of .+-. 0.1 mm can be obtained. The effects of supply pressure, size of switching valves and the effect of multiple valves are discussed, and computer simulation onthe dynamic performances of the pneumatic system is also presented.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.759-762
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• 2002

A ZCT(Zero Current Transition) PWM(Pulse-Width-Modulation) boost converter using parallel MOSFET switch is proposed in this paper. The IGBT(main switch) of the proposed converter is always turned on with zero current switching and turned off with zero current/zero voltage switching. The MOSFET(auxiliary switch) is also operates with soft switching condition. In addtion to, the proposed converter eliminates the reverse recovery current of the freewheeling diode by adding the resonant inductor, Lr, in series with the main switch. Therefore, the turn on/turn off switching losses of switches are minimized and the conduction losses by using IGBT switch are reduced. In addition to, using parallel MOSFET switch overcomes the switching frequency limitation occurred by current tail. As mentioned above, the characteristics are verified through experimental results.

• Journal of the Korea Society of Computer and Information
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• v.21 no.11
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• pp.59-64
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• 2016

In this paper, we design and implement an Application based on android platform, which can control arduino Prime Smart Car using Bluetooth communication. This Application consist of Bluetooth communication module, manual mode module, and line-tracer mode module. In the Bluetooth communication module, it checks the on/off status of Smartphone Bluetooth. If Bluetooth status is off, it activates Bluetooth, selects the corresponding device from Bluetooth device list, and connects with a pair. In order to reduce coding time, we implements Bluetooth communication using inherited class from android Bluetooth package. In the manual mode module, it implements six direction moving button and stop button, which can control arduino Prime Smart Car. In the line-tracer mode module, it implements Prime Smart Car with self-driving function using TCRT5000 sensor. And moving button and stop button is disabled.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.573-579
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• 2007

The Leaky Bucket mechanism has been studied in many areas. There has been much interest in flow control in High Speed Networks using the Leaky Bucket. In this paper, We propose the Burst Tokens Fill method that performs well in Leaky Bucket to control the average rate, peak rate, and burst size. This scheme show the improvement of performance. However, This method does not apply all area of applications. Especially application of on-off shape is appropriate and the other area must need to care for appling this scheme.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.9
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• pp.431-436
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• 2005

This paper studies a novel boost DC-DC converter operated high efficiency for discontinuous current mode (DCM) control. The converter worked in DCM eliminates the complicated circuit control requirement, reduces a number of components, and reduces the used reactive components size. In the general DCM converter, the switching devices are turned-on the zero current switching (ZCS), and the switching devices must be switched-off at a maximum reactor current. To achieve the zero voltage switching (ZVS) at the switching turn-off, the proposed converter is constructed by using a new loss-less snubber circuit. Soft-switched operation of the proposed boost converter is verified by digital simulation and experimental results. A new boost converter achieves the soft-switching for all switching devices without increasing their voltage and current stresses. The result is that the switching loss is very low and the efficiency of boost DC-DC converter is high.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.285-288
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• 2001

In this paper we proposed the on line volt/var control schemes of the load Tap Changer (LTC) transformer and shunt capacitor bank for distribution volt/var regulation. In the existing volt/var control of the distribution substation, the voltage of feeders and var of distribution systems is mainly controlled by the LTC transformer tap position and on/off status of the shunt capacitor. The LTC and shunt capacitor bank has discrete operation characteristics and therefore it is very difficult to control volt/var at the distribution networks within the satisfactory levels. Also there is limitation of the operation times of the LTC and shunt capacitor bank because it is affects on their functional lifetime. The proposed volt/var control algorithm determine an optimal tap position of LTC and on/off status of shunt capacitors at a distribution network with the multiple feeders. The mathematical equations of the proposed method are introduced. Simple case study was performed to verify the effectiveness of the proposed method.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.751-753
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• 1999

In this paper, a simple SR method of AC motor has introduced. The method achived by appling the Pulse-Width Modulation(PWM) method to control the ON and OFF time of motor. The method is simple, practicable and has no problem of shift and out of control which is existed in SR method of SCR.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.8
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• pp.704-710
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• 2017

The supply of the liquid oxygen into a rocket combustor is simply controlled by the 'on' and 'off' positions of a main oxidizer shut-off valve. However, the partially opened position of a three-position valve can control and optimize the engine start transients by regulating the liquid oxygen flow rate during the start-up of the engine. In this paper, the design and performances of a three-position pneumatic poppet valve, which is intended to be employed in liquid rocket engines, have been presented.