• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.243-246
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• 2002

In this paper, an advanced load balancing algorithm in nth order Hypercube distributed system has been proposed. The new algorithm uses centralized load-balancing to avoid blocking phenomenon and processor thrashing, and shows the results which makes loads to approach average value of loads. The new algorithm os compared with several other algorithm and it shows a merit in cost function value.

• Proceedings of the KIEE Conference
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• summer
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• pp.1355-1357
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• 2004

The hydraulic brake system is recently apply to the AGT system such merit as installation is convenient and brake force is stronger than pneumatic brake system. The hydraulic brake system consist of brake operating unit, electronic control unit, air compressor and pneumatic/hydraulic tranducer. The components of it are controlled and designed to perform the function of brake system. Therefore, This paper design and the hydraulic brake system and propose the derection of development for Urban Transit System.

• Applied Science and Convergence Technology
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• v.25 no.5
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• pp.88-91
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• 2016

The $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$+xwt%PbO systems at temperature of $1250^{\circ}C$ for 4 hours was successful synthesized. In this study, PbO-doped $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$ systems with non-linear behaviors showed ordering-degree dependence at the low temperature range were prepared using the columbite precursor method. And the characteristic of remnant polarization vs. electric field were analyzed. The pyroelectric, dielectric and piezoelectric properties of partially disordered $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$+xwt%PbO solid solutions were studied as a function of temperature, frequency, and electric field. It showed distinct features of temperature dependent of pyroelectric coefficient, spontaneous polarization and dielectric constant at about $50^{\circ}C$. The figure of merit was calculated as pyroelectric coefficient, dielectric constant and dissipation factor. It was found that the high voltage responsivity FV, high detectivity FD were $0.0373m^2/C$ and $0.6735{\times}10^{-4}Pa{-1/2}$, respectively, in the $Pb[(Mg_{1/3}Ta_{2/3})_{0.7}Ti_{0.3}]O_3$+3.0 wt%PbO system.

• 대한공업교육학회지
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• v.30 no.1
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• pp.19-36
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• 2005

The purpose of this study is to develop the Public Practice Center's teaching-learning model by applying blended learning strategies which is complementary to the expected problems such as expansion of the educational object and diversity of the curriculum to maximize the educational effect and to analyze activation types of the Practical Practice Center to expand the Public Practice Center's function and role by studying the document. Blended Learning Strategies are established in consideration of the following eight (8) factors ; learning environment, learning purpose, learning contents, learning time, learning place, learning type, learning media, type of interaction. It is redesigned and amended to the KEDI's individual confirmation instruction model for skill learning (1975) which is considered to be effective in the filed of education by applying features, educational contents of the Public Practice Center's teaching and merit of Blended Learning Strategies simultaneous. This model is composed of six (6) steps as shown below; 1. Understanding on the purpose and orientation 2. Observation for demonstration of fundamental skill 3. Ex on-line learning 4. Acquirement of element skill 5. Confirmation for acquirement of fundamental skill 6. After on-line learning. Further to this, this model is designed so that the above eight factors will be applied to the students effectively and the merit of e-learning and off-line practice will be mixed to the learner's expectation and satisfaction.

• Journal of the Korean Graphic Arts Communication Society
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• v.22 no.1
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• pp.29-38
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• 2004

With increasing interests in environment matters over the world, incessant efforts to develop products which meet these environmental requirements have been made also in paint industry. Among the efforts in this field, UV(Ultra Violet) curing system is focused as one of most potential system. It is because this system not only proved to be environmentally friendly compared with heat curing system or other system but also has economical merit of smaller facility, less energy consumption, and better productivity. Superior properties in many application is surely one of its dominant merit. With these advantage UV system is applied to a variety of industrial fields and expected to have continuous growth in the future. As practical application of UV system has shown lasting progress, R&D on basic material of this system keeps up with. This is a study on photo-initiator that is a fundamental substance in UV curing method and amine, its aid for better effect. After reviewing on them in the aspects of function, economy, and stability, optimal foumula is pursued through experiments when applied to real products.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.423-426
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• 2001

Recently we have reported that the meander-patterned amorphous FeCoSiB films exhibit large change in their high frequency impedance by applying a strain, suggesting that the films are very attractive for making of a highly sensitive strain sensor elements. In this study, the effect of anisotropy on a change in the impedance of sputtered amorphous film patterns was investigated in the frequency range from 1MHz to 1GHz. As a function of applied strains, the high frequency impedance was extremely changed in the case of film patterns with transverse anisotropy due to excellent magnetomechanical coupling properties. As a summary, the maximum figure of merit f has measured about 2600 in the case of transverse anisotropy, and about 500 in the case of longitudinal anisotropy at 500 MHz. These values of F are approximately more than 1000 times higher than that of a conventional metal strain gauge (F 2) and more than 10 times higher than that of a semiconductor gauge (F 200).

• Transactions on Electrical and Electronic Materials
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• v.17 no.2
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• pp.121-124
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• 2016

ZnSnO₃ (ZTO)/Ag/ ZnSnO₃ (ZTO) trilayer films were prepared on glass substrates by radio frequency (RF) and direct current (DC) magnetron sputtering. The electrical resistivity and optical transmittance of the films were investigated as a function of the Ag interlayer thickness. ZTO films with a 15 nm thick Ag interlayer show the highest average visible transmittance (83.2%) in the visible range. In this study, the highest figure of merit (2.1×10⁻² Ω cm) is obtained with the ZTO 50 nm/Ag 15 nm/ZTO 50 nm films. The enhanced optical and electrical properties of ZTO films with a 15 nm thick Ag interlayer are attributed to the crystallization of the Ag interlayer, as supported by the distinct XRD pattern of the Ag (111) peaks. From the observed results, higher optical and electrical performance of the ZTO film with a 15 nm thick Ag interlayer seems to make a promising alternative to conventional transparent conductive ITO films.

• Smart Structures and Systems
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• v.21 no.5
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• pp.653-668
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• 2018

This work proposes and investigates re-centering negative stiffness dampers (NSDs) for vibration suppression in high-speed trains. The merit of the negative stiffness feature is demonstrated by active controllers on a high-speed train. This merit inspires the replacement of active controllers with re-centering NSDs, which are more reliable and robust than active controllers. The proposed damper design consists of a passive magnetic negative stiffness spring and a semi-active positioning shaft for re-centering function. The former produces negative stiffness control forces, and the latter prevents the amplification of quasi-static spring deflection. Numerical investigations verify that the proposed re-centering NSD can improve ride comfort significantly without amplifying spring deflection.

• Electronic Materials Letters
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• v.14 no.6
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• pp.725-732
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• 2018

The thermoelectric and transport properties of Ti-doped FeVSb half-Heusler alloys were studied in this study. $FeV_{1-x}Ti_xSb$ (0.1 < x < 0.5) half-Heusler alloys were synthesized by mechanical alloying process and subsequent vacuum hot pressing. After vacuum hot pressing, a near singe phase with a small fraction of second phase was obtained in this experiment. Investigation of microstructure revealed that both grain and particle sizes were decreased on doping which would influence on thermal conductivity. No foreign elements pick up from the vial was seen during milling process. Thermoelectric properties were investigated as a function of temperature and doping level. The absolute value of Seebeck coefficient showed transition from negative to positive with increasing doping concentrations ($x{\geq}0.3$). Electrical conductivity, Seebeck coefficient and power factor increased with the increasing amount of Ti contents. The lattice thermal conductivity decreased considerably, possibly due to the mass disorder and grain boundary scattering. All of these turned out to increase in power factor significantly. As a result, the thermoelectric figure of merit increased comprehensively with Ti doping for this experiment, resulting in maximum thermoelectric figure of merit for $FeV_{0.7}Ti_{0.3}Sb$ at 658 K.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.3
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• pp.213-218
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• 2017

In this study, a reverse design of the F-theta lens was proposed for a 2D scanner in remote welding applications. The curvature and distance of the lens were set as variables, and the focal length of the lens was set as the marginal ray height. The ZEMAX commercial software was used to perform a simulation with unlimited iterations for the optimization process. The target value was optimized using the internal Merit function with the weight factors of focal length and spot diameter. The number of lenses was four, and the focal length obtained from the results was 135mm that is slightly less than that of the commercial lens, which is set with a focal length of 185 mm. The calculated spot diameters are $1.3{\mu}m$, $6.2{\mu}m$, and $16.1{\mu}m$ for $0^{\circ}$, $12.5^{\circ}$ and $23^{\circ}$ of incident laser beam, respectively. It is expected that an optimized lens design is possible by performing the reverse design of a lens by the ray tracing method.