• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2910-2912
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• 2000

Since the heavy-duty power manipulator has high ratio gear reducers at its joints, its dynamic characteristics are much slower than that of the master manipulator and it is likely to encounter the saturation in the input magnitude when it is used as the slave manipulator in telemanipulator systems. This paper proposes a force reflecting position control scheme for 2 axes heavy-duty power manipulator which compensates control input saturation. A series of experiments is shown to give an excellent tracking performance regardless of saturation.

• Korean Journal of Optics and Photonics
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• v.1 no.2
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• pp.162-168
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• 1990

Two ZnSe loss plates were installed in the resonator of waveguide CO2 laser which consisted of Pyrex capillary tube in order to change the internal loss. By rotating the loss plates, the output variations with the internalloss was measured on various discharge conditions. The variations could be explained by the Rigrod theory. and the saturation power and the unsaturated gain coefficient were determined by fitting of the experimental results. It was found that the saturation power increased while the unsaturated gain coefficient reduced as the discharge current or the gas flow rate increased.reased.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.333-336
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• 2001

The transient response in PDFA(Praseodymium-Doped Fiber Amplifier) is theoretically investigated. The PDFA has the spectral gain band in 1.3${\mu}{\textrm}{m}$. The transient model includes the transient buildup of the population inversion, the pump power, and the signal power and their transient variation along the fiber amplifier. The numerical analysis of transient model can predict the gain saturation, the variation of pump power and the gain as a function of the fiber length. It also shows the gain saturation and recovery effects depending on the pumping rate lead to distortion and saturation in the amplification of optical pulse. The results of numerical analysis, for the case of the Pr ion concentration of 1000ppm and the pump power of 0.5W the gain saturation is obtained 30dB at the length of 5m and the saturation time of upper level is 250 $mutextrm{s}$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.905-908
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• 2001

The microstructure and the magnetic properties of Mn-Zn ferrite, which were power loss and saturation magnetic flux density, were investigated as the function of the process before firing. The highest initial permeability and the lowest power loss were attained to the specimen with CaO 400 ppm as a resulted from the highest solubility to SiO$_2$and the creation of liquid phase which improved sintering. The biggest grain size, the highest saturation magnetic flux density and the lowest power loss, which was resulted from that the eddy current loss increased as grain size increased but the hysteresis loss much more decreased and the hysteresis loss strongly influenced on the total power loss rather than the eddy current loss, were obtained to the Mn-Zn ferrite added 2wt% PVA. The power loss was lowest and the saturation magnetic flux density was highest in case of 1 ton/$\textrm{cm}^2$ and the grain size was not influenced.

• Transactions of the Korean Society of Mechanical Engineers
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• v.5 no.2
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• pp.151-157
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• 1981

The concept of available evergy has been adopted in terms of effectiveness for and evaporator of vapor power cycle. This kind of practice is emphasezed in a case of heat and power cogeneration in order to find optimum condition for the energy utilzation of the exhaust gas. It has beed shown that the optimum condition can be given in terms of the saturation pressure or the saturation temperature of the working fluid. Similar method has been applide to show that the effectiveness is increased asymptotically with the number of evaporator stanges.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.5
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• pp.531-539
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• 1991

We develop an analytical model of the static and the dynamic characteristics of amorphous silicon thin film transistors (a-Si TFTs) in order to incorporate into a widely used circuit simulator such as SPICE. The critical parameters considered in our analytical model of a-Si TFT are the power factor (XN) of saturation source-drain current and the effective channel length (L') at saturation region. The power factor, XN must not always obey so-called

• Journal of the Korean Society for Precision Engineering
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• v.14 no.4
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• pp.104-109
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• 1997

A robust controller design to corrdinate a robot manipulator under unknown system parameters and bounded disturbance inputs is presented in this paper. Generally, robust controllers require high input torque so that they may face input saturation in actual application due to the power limitation of the actuator. To solve this problem, an improved robust controller with saturated input torque using a fuzzy logic control is proposed. Numerical examples are shown to validate the proposed controller using two degree-of-freedom planar arm.

• Water for future
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• v.28 no.5
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• pp.129-140
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• 1995

In this study we derived steady-state relationships between surface saturation area and subsurface outflow, and between surface saturation area and soil moisture storage through numerical experiments with Richards equation on a hillslope. Numerical experiments analyzed the sensitivity of topographic and soil hydraulic properties on steady-state relationships between surface saturation area and subsurface outflow. And the power law for the extent of surface saturation area was determined as a function of subsurface outflow or soil moisture storage.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.236-243
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• 2008

This paper analyses magnetic flux saturation of matching transformer considering characteristic of dynamic voltage restorer(DVR) system to solve voltage sags which are considered the dominant disturbances affecting power quality. This DVR consist of PWM inverter to inject arbitrary voltage, LC low pass filter and matching transformer for isolation and grid connection. However, the matching transformer has an excess of inrush current by magnetic flux saturation in the core of transformer. Due to this inrush current, the rating of matching transformers is double for needed nominal rating for protection of DVR. Therefore, in this paper, an advanced modeling method of magnetic flux saturation is used to analyze a magnitude and characteristic of magnetizing current. Simulation and experimental results considering characteristic of DVR system are provided to demonstrate the validity of the proposed analysis method.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.49 no.10
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• pp.572-581
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• 2000

When the manipulator consisting of high ratio gear reducers at its joints is used as the slave manipulator in teleoperated systems, its dynamic characteristics is much slower than that of the master manipulator and it is likely to encounter the saturation in the input magnitude. The control input saturation generates an windup phenomenon that the system stability and position tracking performance of the slave manipulator are to be deteriorated. This paper proposes an force reflecting control scheme and its design method which compensates the control input saturation with absolute stability. The proposed scheme is shown to give a stable force reflection while compensating for control input saturation effectively.