• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.5
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• pp.373-378
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• 2001

The optimization method based on an enhanced genetic algorithms is for multimodal function optimization in this paper. This method is consisted of two main steps. The first step is a global search step using the genetic algorithm(GA) and function assurance criterion(FAC). The belonging of an population to initial solution group is decided according to the FAC. The second step is to decide the similarity between individuals, and to research the optimum solutions by single point method in reconstructive search space. Four numerical examples are also presented in this papers to comparing with conventional methods.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.7
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• pp.525-530
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• 2012

We present the results of a study of the polarizing photovoltaic (PV) effects in an aligned polymer bulk heterojuction PV layer. The fairly uniform in-plane uniaxial alignment of the PV layer with a macroscopic axial orientational order parameter of 0.40 was achieved by means of a simple rubbing technique. Moreover, reflective polarizing PSCs having the aligned PV layers were applied to power-generating reflective type liquid crystal displays (LCDs), which exhibited a maximum contrast ratio of 1.7. These results form a promising foundation for various energy harvesting polarization dependent opto-electrical LCD device applications.

• The Journal of Information Technology
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• v.10 no.2
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• pp.29-35
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• 2007

In this paper, we describe a study on the relationship between alkaline magenta emulsion manufacture and hardening test of films. The hardeners were prepared by condensation of equimolar amounts of trichlorotriazine with benzene-or naphthalene-based amino or oxy acids at 0 to $5^{\circ}C$ and at pH 7, and used as hardening agents for gelatin. The hardening test of alkaline magenta emulsion was studied at pH 8.5. For example I(R=ONa) had strong hardening properties, I substituted with an aminobenzosulfonate moiety (R=NHC6H4-p-SO3Me where Me = K, Na) was a much weaker gelatin hardener, and when substituted with amino- or oxynaphthalene derivative (II, III) did not harden gelatin at all. Compound with 2 dichlorotriazine groups as IV exhibited hardening properties. The hardener can be used in alkaline magenta emulsion layer of film and showed good hardening effect.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.533-538
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• 2001

This paper describes a combinational method to compute the global and local solutions of optimization problems. The present hybrid algorithm uses both a genetic algorithm and a local concentrate search algorithm (e. g simplex method). The hybrid algorithm is not only faster than the standard genetic algorithm but also supplies a more accurate solution. In addition, this algorithm can find the global and local optimum solutions. The present algorithm can be supplied to minimize the resonance response (Q factor) and to yield the critical speeds as far from the operating speed as possible. These factors play very important roles in designing a rotor-bearing system under the dynamic behavior constraint. In the present work, the shaft diameter, the bearing length, and clearance are used as the design variables.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.2 s.233
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• pp.287-293
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• 2005

In the present study, to determine the flow rate of droplets supplied to heat transfer surface after (j-1)th rebound, $D_X[j{\ge}2]^{\ast}$, it was assumed that the rebound droplets are distributed according to the Gaussian distribution from 0 to L, in which the flight distance L is determined by maximum flight distance $L_{max}$. We also assumed that $L_{max}$ is dependent on the air flow velocity and mean size of droplets. The local heat flux of a dilute spray in high temperature region was predicted using the newly evaluated $D_X[j{\ge}2]^{\ast}$. In addition, the predicted results by the present model were compared with the existing experimental data.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.449-455
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• 2001

도로교통소음의 저감을 위해 설치되는 방음벽의 성능평가를 위해서는 흡음률 및 투과손실과 같은 음향성능에 대한 평가뿐만 아니라, 풍압 및 충격하중과 같은 구조성능과 방음판 제작에 사용되는 재질에 관한 성능평가도 수반되어야 한다. 따라서, 본 논문에서는 이러한 방음벽의 성능평가를 위한 음향 구조 및 재질에 관한 시험 및 평가방법을 제시하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.458-461
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• 2008

The primary objective of this study is to provide simple analytical tools to estimate dynamic characteristics of steel framed floor system in hospital building for vibration serviceability due to human activities, bogie, medical equipment. and so on. In order to evaluate the dynamic characteristics and vibration levels according to steel framed floor system, we had executed impact test and measurement on steel structure floor system in various hospital buildings. But perhaps most importantly, how to make the most of deduced design factor for design of hospital building. therefore we presented the access method such as the three-dimensional F.E. numerical analysis on the basis of the design drawing, and the properties of all floors for estimation of vibration level in hospital building.

• Journal of ILASS-Korea
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• v.19 no.1
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• pp.15-18
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• 2014

In the present study, experiment on the evaporation of pure water droplet on heated surface was conducted, and the evaporative heat transfer coefficients were calculated from experimental results. The pure water droplet of about $10{\mu}l$ was applied onto the heat transfer surface, then the shape of the droplet was analyzed during the evaporation. In addition, the effect of surface roughness on the evaporative heat transfer was also investigated. Experimental results showed that the evaporative heat transfer coefficients increased rapidly along with the increase of surface temperature and the heat transfer coefficients increased with the increase of surface roughness.

• Journal of ILASS-Korea
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• v.25 no.2
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• pp.68-73
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• 2020

In the present study, experiments on the film boiling of liquid droplets on oxidized copper surface was conducted. The shape of pure water droplets was observed, and the evaporation rate of them was measured during the film boiling evaporation process. The droplet of initial volume 16 ~ 30 µl was applied onto the oxidized copper surface heated up to 300 ~ 500℃, then the shape of the droplet was analyzed during the film boiling evaporation. Experimental results showed that there was good correlation between dimensionless volume and dimensionless time. However, a significant difference in evaporation rate for small and large droplets discussed in previous study was not found.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.192-197
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• 2001

Before we have made known the study of shape development of interference device for vehicle noise control. It's primary object greatly attenuate the noise due to transport vehicle by small products installed on the noise barrier edge. Also, it is able to improve the insertion loss of a noise barrier without increasing the height. The present time, we set up a newly manufactured products on the noise barrier edge and testify to it's the performance make use of an experiment and evaluation. In this paper the performance of noise barriers with attached newly developed products in terms of shape, absorptive material and split panel, are examined using field test.