• Proceedings of the Membrane Society of Korea Conference
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• 1999.07a
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• pp.79-82
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• 1999

Using Small Angle Light Scattering (SALS), the effect of quench depth on the kinetics of phase separation for ternary solution blends was investigated. The system was composed of two polymers (polystyrene and polybutadiene) and a solvent (toluene). The analyses of the early stage of phase separation were based of the Cahn-Hilliard theory [1,5]. Apparent diffusion coefficients and the fastest mode of fluctuations were evaluated, when quench depth of the system were varied near the critical composition of polymer. In the late stage of phase separation, the domain growth showed a power law with the 1/3 exponent, i.e. $q_m(t)~t^{-1/3}$. For comparison between real images and scattering profiles with time, the image of phase domains with time were obtained by using Laser Confocal Scanning Microscopy (LSCM).

• The Journal of Information Technology
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• v.9 no.1
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• pp.55-63
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• 2006

In this paper, a Hangul recognition system using of Kohonen Network in the phoneme separation and learning is proposed. A Hangul consists of phoneme that are consists of strokes. The phoneme recognition and separation are very important in the recognition of character. So, the phonemes which mismatching has been happened are correctly separated through the learning of neural networks. also, learning rate($\alpha$) adjusted according to error, in order to solved that its decreased the number of iteration and the problem of local minimum, adaptively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.70-75
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• 2013

The electrical separation joint as a filter circuit distributes the track circuit frequency. The electrical separation joint is classified into the interval where reinforcing bars are insulated and not insulated through the length of track circuit. In case of incorrectly setting up the length of electrical separation joint, the amplitude of current on the track circuit is not over standard current which is the standard of current on the track circuit and it effects on the close frequency on track circuit. Then, it makes an accident or makes a train not receive information for train control. In this paper, the electrical separation joint model is suggested and parameters are numerically calculated in the model. Moreover, the length of electrical separation joint is analyzed and is demonstrated by uisng Matlab and PSpice program.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1866-1870
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• 2019

Residual salt separation is an essential step in pyroprocessing because its reaction products, as prepared by electrochemical unit processes, contain frozen residual electrolyte species, which are generally composed of alkali-metal chloride salts (e.g., LiCl, KCl). In this study, a simple technique that utilizes high-temperature gas flux as a driving force to melt and push out the residual salt in the reaction products was developed. This technique is simple as it only requires the use of a heating gun in combination with a gas injection system. Consequently, $LiNO_3-ZrO_2$ and $LiCl-ZrO_2$ mixtures were successfully separated by the high-temperature gas injection (separation efficiency > 93%), thereby demonstrating the viability of this simple technique for residual salt separation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.67-79
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• 1996

This paper presents a composite luminance signal processing system for NTSC, PAL and SECAM standards. Eaxh of the three standards employs its own specifications of subcarmier bandwidth and luminance signal waveform. The proposed system, compatible to the specifications of the three standard and B/W TV, implements variable freqneucy characteristics by controlling filter coefficients. The major features of the system are a luminance/chroma separation unit and an aperture compensation unit. The luminance/chroma separation unit employes a notch filter selection a trap freqneyc to atenuate unwanted color signals in luminance signal bands. The aperture compensation unit comprises two subunits, to provide clear color definition for each of the three standards: a primary compensation circuit and a variable compensation circuits. The proposed system yields a 40 dB gain from the chroma/luminance separation and a 10 dB gain from the aperture compensation unit.

• Journal of Aerospace System Engineering
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• v.7 no.3
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• pp.20-25
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• 2013

In case of cube satellite, it is difficult to realize the same performance as commercial satellite due to its highly restricted unit accommodation space. To maximize the performance of the cube satellite, design concept considering the multi-function of satellite is required. In this paper, mechanism design of cube satellite which is applicable for the holding and release of multi-deployable structures has been proposed and investigated. In addition, a switch mechanism design for the autonomous system operation just after the cube satellite separation from P-POD has also been proposed. The effectiveness of the mechanism design for holding and release of multi-deployable structures has been demonstrated by EM test of the holding and release mechanism.

• Journal of Institute of Control, Robotics and Systems
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• v.1 no.2
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• pp.119-126
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• 1995

The purpose of this study is to develop the technique of energy recovery and energy saving by using the optimization of heat exchanger network synthesis. This article proposes a new method of determining the optimal target of a heat exchanger network synthesis problem of which data feature multiple pinch points. The system separation method we suggest here is to subdivide the original system into independent subsystems with one pinch point. The optimal cost target was evaluated and the original pinch rules at each subsystem were employed. The software developed in this study was applied to the Alko prosess, which is an alcohol production process, for the synthesis of heat exchanger network. It was possible to save about 15% of the total annual cost.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.145-152
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• 1998

This paper presents an optimum design of a rotor-bearing spindle system for a ultra centrifuge (80,000 RPM) supported by ball bearings with nonlinear stiffness characteristics. To obtain the nonlinear bearing stiffnesses, a ball bearing is modeled in five degrees of freedom and is analyzed quasi-statically. The dynamic behaviors of the nonlinear rotor-bearing system are analyzed by using a transfer-matrix method iteratively. For optimization. we use the cost function that simultaneously minimizes the weight of a rotor and maximizes the separation margins to yield the critical speeds as far from the operating speed as possible. Augmented Lagrange Multiplier (ALM) method is employed for the nonlinear optimization problem. The result shows that the rotor-bearing spindle system is optimized to obtain 9.5％ weight reduction and 21％ separation margin.

• Journal of Power System Engineering
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• v.3 no.1
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• pp.29-37
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• 1999

The flow characteristics of a NACA0012 airfoil was investigated in rectangular water circulating channel. The flow patterns around an airfoil at various angles of attack between $0^{\circ}\;and\;30^{\circ}\;at\;Re=1.91{\times}104$ were visualized and measured with 2-D PIV system and laser sheet illumination. Flow behaviors such as velocity distribution, kinetic energy and flow separation etc. around an airfoil were obtained by means of 2-D PIV system. The behaviors show the difference of flow pattern clearly and separation phenomena become more active with increasing angle of attack.

• The Journal of the Acoustical Society of Korea
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• v.18 no.6
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• pp.3-8
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• 1999

In this paper, we propose a new active noise control system that cancels the only noise signal from the mixture selectively. A blind source separation realized by a dynamic recurrent neural network is used as a preprocessor of the active noise control system and separates the desired signal and the noise signal. The active noise control system adaptively generates an anti-noise signal to remove the only noise signal separated by the blind source separation. Computer simulation results show that the proposed scheme is effective to construct a selective attention system.