• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06a
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• pp.29-34
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• 1999

We present a practical method for removing biotches and restoring their mission data. To detect blotches, we employ a robust approach of local analysis of spatiotemporal anisotropic brightness continuity Our approach uses first-order spatiotemporal directional derivatives to select the smoothest direction for each examined pixel, and puts out the incorruption probability that he examined pixel may not be corrupted by blotches. As the restoration filter, were employ a spatiotemporal fuzzy filter whose response is adaptively controlled according to a fuzzy rule defined by the incorruption probability. The fuzzy filter is composed of the two different filter of the identity filter and the spatiotemporal directional-weighted-mean filter, and will put out an intermediate value between the original input brightness and the directional-weighted-mean brightness. We design the fuzzy rule in advance by a standard supervised learning fuzzy rule in advance by a standard supervised learning method. The computer simulations are presented.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.550-557
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• 1997

Production of so-called Halon fire extinguishing agents has been prohibited since January 1994 because of their ozone depletion potential, To replace them, several hydrofluorocarbons and fluorocarbons have been developed and utilized. A number of studies on flame extinguishing concentrations and flammability peak concentrations of them have been done. Although there was enough information for practical purpose, more knowledge on fire extinguishing characteristics of them should be attained for efficient use of them. In this study, peak concentrations of methane/air mixtures with gaseous halogenated hydrocarbons were measured at elevated temperature, because the former studies were done at room temperature and temperature of a fire room can be higher than usual. Measurement was done at $200^{\circ}C$, because measuring system could not endure higher temperature. This study revealed that peak concentrations of halogenated hydrocarbons differed little at elevated temperature. The halogenated hydrocarbons have almost the same fire extinguishing ability as Halon 1301.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.372-376
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• 1999

The deposited Cu film on the ferrite magnet was more deposited comparing with that on the plastic magnet. The Cu film became thicker on the S pole comparing with that on the N pole in the both of magnets. The thickness and texture coefficient of deposited copper film affected with direction of line of magnetic force. The difference of pole had little or no effect to the texture coefficient of deposited nickel film. The reaction rate on ferrite magnet and S pole was faster comparing with that on plastic magnet and N pole.

• Wind and Structures
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• v.35 no.5
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• pp.323-336
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• 2022

This study investigates the applicability of the direct identification of flutter derivatives in the time domain using Rational Function Approximation (RFA), where the extraction procedure requires either a combination of at least two wind speeds or one wind speed. In the frequency domain, flutter derivatives are identified at every wind speed. The ease of identifying flutter derivatives in the time domain creates a paradox because flutter derivative patterns sometimes change in higher-order polynomials. The first step involves a numerical study of RFA extractions for different deck shapes from existing bridges to verify the accurate wind speed combination for the extraction. The second step involves validating numerical simulation results through a wind tunnel experiment using the forced vibration method in one degree of freedom. The findings of the RFA extraction are compared to those obtained using the analytical solution. The numerical study and the wind tunnel experiment results are in good agreement. The results show that the evolution pattern of flutter derivatives determines the accuracy of the direct identification of RFA.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.8.1-8.1
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• 2007

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1995.10a
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• pp.95-100
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• 1995

-양사면에서의 쇄파현상은 많은 연구에 의해 매우 선명하게 됐다. 그러나, 실제의 해저지형은 연안사주가 존재하는 복합단면지형의 경우가 많고, 이러한 지형에서의 쇄파현상은 충분히 해명되어 있지 않다. 본 연구에서는 복합단면에서의 쇄파감쇠과정을 검토하는 기초적지형으로써 사면에 연접한 수평상을 선택하여 검토하도록 한다. 이러한 지형을 여기서는 수평step이라고 한다. 수평step상을 대상으로 하는 기존의 연구로써 굴천·곽(1966), 수구(1978)등을 들 수 있다. (중략)

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.04a
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• pp.62-66
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• 2010

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.962-966
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• 1989

A Digital Signal Processor (abbreviated to DSP) is used not only for digital signal processing but also for kinematic controls[l]. Then applications to these fields are expected to be developed. We propose a function calculation method on DSP which occupies no table memory. By using these functions, more fast or more accurate control will be achieved without using function table.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1200-1203
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• 2002

A temperature compensated Crystal Oscillator is widely used for the stable frequency source of mobile communication equipments. Recently, it has become necessary to reduce power consumption of TCXOs. In this paper, we have proposed a TCXO using weak inversion MOS transistors and have evaluated its fundamental characteristics.

• Progress in Superconductivity and Cryogenics
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• v.8 no.4
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• pp.1-7
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• 2006

This paper reviews AC loss characteristics of high $T_c$ superconductors. The mechanisms of AC loss generation are explained briefly, and AC losses are classified by the magnetic field components which generate them. A couple of analytical formulae of AC losses, which are useful for simple and rough AC loss estimations, are presented. AC loss characteristics of single BSCCO multifilamentary conductors and single YBCO coated conductors are reviewed based on previous experimental and numerical studies. AC loss characteristics of those two types of practical high $T_c$ superconductors are compared with each other.