• Journal of the Optical Society of Korea
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• v.7 no.3
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• pp.188-192
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• 2003

The modal characteristics of the photonic crystal fibers are analyzed using the reliable and efficient plane wave expansion method. The mode profile, effective index and group velocity dispersion are obtained by solving Maxwell's vector wave equations without any approximation. The zero dispersion condition of a photonic crystal fiber is derived over a wide range of wavelengths. Higher-order modes are also easily found as a by-product of the plane wave expansion method. This method can be used to quickly and accurately design various optical properties of photonic crystal fibers.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3259-3263
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• 2007

This paper describes the proceedings of creating countermeasures after analysis and maintenance be able to conduct operation safely in a power plant. in order to operate the power plant in a stable and reliable way, the best condition of the govemor system can be maintained through the response characteristic analysis of the control device for the pitch blade control hydraulic actuator. The fan pitch blade control hydraulic actuator of a 500MW large-scale boiler is frequently operated under normal operation conditions. Common problems or malfunctions of the pitch blade control hydraulic actuators leads to the decline of boiler thermal efficiency and unexpected power plant trip. The inlet and outlet gas can be controlled by using the fan pitch blade control hydraulic actuator in order to regulate the internal pressure of the furnace and control the frequency in the power plant facility which utilizes soft coals as a power source.

• Korean Journal of Materials Research
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• v.13 no.3
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• pp.155-159
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• 2003

The polypyrrole and polyaniline thin film sensors which were made by chemical polymerization were employed to detect ethanol gas. With a single sensor element we can obtain characteristic patterns of behaviour across a very wide frequency range when measuring either resistance or capacitance. Impedance spectroscopy was employed to study the gas sensing behavior of both capacitance and resistance based sensors with conducting polymer as the active sensing element.

• The Journal of Korean Medical History
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• v.15 no.2
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• pp.21-44
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• 2002

"Dong Ui Bo Gam" was written by Huh jun that was influenced by Cho Sun Sung Confucianism's environment had been receptive to rich idea. "Dong Ui Bo Gam" "Shin Hyung Mun" was composed of the base on a full understanding in taoist idea. It had a real systemical structure, was help to taoist training. The taoist idea of "Dong Ui Bo Gam" was made up of the extension of mature theory and training in Cho Sun Dan Hak. Specially, The taoist idea of "Dong Ui Bo Gam" was had an effect on "Euibangyoochui" better as compared with "Dong Ui Bo Gam" "Shin Hyung Mun" in contents "Shin Hyung Jang Bu DO" generalized the whole contents of "Dong Ui Bo Gam", was influenced by taoist idea, also peculiar method that was not searched in other medical books. 'Heart 心' was handled importantally in "Dong Ui Bo Gam" "Shin Hyung Mun" under the influence of taoist idea and Cho Sun Sung Confucianism.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.373-375
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• 2004

The SRM is more robust and lower cost than other type motors. The inverter for SRM cannot have shoot through fault, since a phase winding of SRM is independent of other phase windings. The SRM has high starting torque and high power density. But it has torque ripples due to nonlinear magnetic characteristics. Therefore, SRM has highly non-linear torque producing characteristics. Because fuzzy logic is a flexible and general-purposed method for implementing non-linear dynamic functions, it is effective for the control of high current SRM. We design the fuzzy controller and demonstrate the fuzzy control system by MATLAB.

• Journal of Sensor Science and Technology
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• v.23 no.4
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• pp.217-223
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• 2014

Nerve agents are major chemical warfare agents with the "G series" and "V series" being the most widely known because of their lethal effect. Although not conspicuously used in major wars, the potential detrimental impact on modern society had been revealed from the sarin terror attack on Tokyo subway, which affected thousands of people. In this mini-review, major nerve agents of the "G series" and "V series" have been described along with various types of their detection methods. The physical properties and hydrolysis mechanisms of the major nerve agents are discussed since these are important factors to be considered in choosing detection methods, and specifying the procedures for sample preparations in order to enhance detection precision. Various types of extraction methods, including liquid-phase, solid-phase, gas-phase and solid-phase microextraction (SPME), are described. Recent development in the use of gas sensors for detecting nerve agents is also summarized.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2005.05a
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• pp.95-99
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• 2005

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2005.05a
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• pp.105-109
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• 2005

• Journal of Korea Multimedia Society
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• v.20 no.3
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• pp.491-499
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• 2017

The Information & Communication Technology (ICT) and the Internet of Things (IoT) have become the major issues in Republic of Korea recently. While RS-232, Zigbee, and WiFi-related technologies are used in the ICT-based systems, we focus on the Power Line Communication (PLC) in this paper. By carrying out OPNET simulations, we've implemented the PLC Router Node Model, PLC Terminal Node Model, PLC Link Model, and PLC Palette Model and executed the simulations arranging 20 holds within the range of 400m (20m apart). As a result, we confirmed that the slient node problem had occurred at the point of 200m-2000m (as of 2016) distance preventing further communications. However, the control group, by contrast, was able to carry out the communications by installing a router. We expect that this paper will contribute to the development of a foundation technology which will saves costs by performing the simulation prior to building actual large-scale ICT Complex in the future work.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.721-724
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• 2017

Designing the User-Based Voluntary Service Recommendation Program proposed in this study was motivated by the fact that it is not easy for volunteers to find a place for their services. Even though there are many volunteer centers or organizations, volunteers often experience difficulty in where and how they should apply for their work as those places are not well promoted. Thus, this program has been designed by applying the mobile push services along with location technology. The authors plan to introduce the program to the public as an open source by implementing the program with both Android and Python - hoping that the program will be useful to the users and volunteer organizations.