• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.355-359
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• 1992

This paper presents a procedure to design a real time control system for a magnetic levitation system based on the state space approach by adopting a control method compensating attractive force according to load variation of maglev vehicle. Also the paper has realized a robust control algorithm for the change of self-inductance parameters and the disturbance such as the change of mass of Maglev vehicles. The theoretical results are applied to the gap control problems of an attractive-type-magnetic levitation system and the effectiveness is proved by the implementation of digital control using 16 bits microcomputer.

• Communications of the Korean Mathematical Society
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• v.22 no.1
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• pp.91-109
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• 2007

In this paper, we derive a change of scale formula for conditional Wiener integrals, as integral transforms, of possibly unbounded functions over Wiener paths in abstract Wiener space. In fact, we derive the change of scale formula for the product of the functions in a Banach algebra which is equivalent to both the Fresnel class and the space of measures of bounded variation over a real separable Hilbert space, and the $L_p-type$cylinder functions over Wiener paths in abstract Wiener space. As an application of the result, we obtain a change of scale formula for the conditional analytic Fourier-Feynman transform of the product of the functions.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2013.11a
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• pp.102-105
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• 2013

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2019.08a
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• pp.278-278
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• 2019

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.432-437
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• 1999

We have fabricated an in situ ellipsometer operating at He-Ne wavelength. It can be applied to the real-time, in-situ tracking of the ellisometric change which occurs during various sample treatments. As a rotating analyzer type, all optical elements and related parts are designed to share a common hollow-axis configuration, and hence the ellipsometer is compact in shape and simple in design. It is mountable on the spare ports of vacuum chamber with ease. Using this ellipsometer, we observed the effective density variation of previously grown $TiO_2$ thin films by using electron beam evaporation. The packing density of the as-grown film was 82%. When exposed to atomsphere, the micro-void of the film was filled with water vapor. This water-filled $TiO_2$ thin film was subject to heating/cooling cycles in vacuum and the ellipsometric variation versus temperature and cycling number was measured in real time using this in situ He-Ne ellipsometer.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.96.2-96.2
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• 2014

Using solar occultation data obtained by Cassini/Visual Infrared Mapping Spectrometer (VIMS), we were able to retrieve the 1 - 5 mm optical-depth spectra of the Titanian haze, for which only selected wavelength and altitudinal ranges were previously analyzed. We found that the gross 1 - 5 mm shapes of the retrieved haze spectra are significantly different from the spectra of tholin samples in the literature. We also derived the vertical variation of the spectral structure of the $3.3-3.4{\mu}m$ absorption feature of the Titan haze from the VIMS data recorded between 250 and 700 km altitude. We found a marked change between 480 and 580 km in the relative amplitudes of the 3.33 and $3.38{\mu}m$ features which are characteristic of aromatic (double C=Cchains or rings) or aliphatic (single C-C chains) structural groups, respectively. Dicussions on this spectral and altitudinal variation will be presented.

• Journal of the Korean Society for Railway
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• v.3 no.3
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• pp.131-138
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• 2000

The design of current collection system of high speed train requires the fundamental understandings for the dynamic characteristics of catenary system and pantograph. The stiffness of catenary system of high speed train has the varying characteristics for the change of contact point with pantograph, since the supporting pole and hanger make the different boundary conditions for the up-down stiffness of a trolley wire. The variation of stiffness results in Mathiue equation, which characterizes the stability of the system. However, the two-term variation of the stiffness due to span length and hanger distance cannot be solved analytically. In this paper, the stiffness variations are calculated and the physical reasoning of linear model and one term Mathieu equation are reviewed. And the numerical analysis for the two-term variation of the stiffness is done for the several design parameters of pantograph.

• Journal of the Korean Home Economics Association
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• v.24 no.3
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• pp.51-58
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• 1986

This study is to investigate the Function of sleeve for the construction of cuffs. Three measuremental items of sleeve cap high, length of sleeve and puff quantity of upper sleeve cap are compared between when the experimental man raises righthand static pose. The wearing test is done in sewing cuffs of either fixing up cuffs or not-fixing up cuffs, and in no cuffs. Three measuremental items are pulled length from sleeve end, pulled length from side waist line, and pulled dimensions from waist line. 1. The result according to the length and dimensions variation caused by a change of sleeve cap high. 2. The results according to the length and dimensions variation caused by a sort of sleeve length. 3. The results according to the length and dimension variation caused by the puff quantity of sleeve cap.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.663-671
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• 2001

This study estimated the impacts of the interest rate change on the forest products import quantities in Korea. The first objective is to analyze whether there is any causal relationship between change in the interest rate and changes in the import quantities of forest products in Korea. And the second objective is to evaluate the dynamics of the impacts of the interest rate change on the forest products import quantities in Korea. The relationship between the interest rate and the import quantity was represented by bivariate vector autoregressive model. Whether there is any causal relationship between change in the interest rate and changes in the import quantities of forest products was analyzed by the causality test. And the dynamics of the impacts of the interest rate change on the forest products import quantities were evaluated by variance decomposition analysis and impulse response analysis. The import quantity of forest products can be explained by the lagged interest rate variables and the lagged import quantity variables in Korea. Change in the interest rate causes change in the plywood import quantity in Korea. In the bivariate model of the plywood import quantity, after three months, the interest rate change accounts for about twenty percent of variation in the import quantity, and its own change accounts for about eighty percent of variation in the import quantity. On the other hand, the impact of a shock to the interest rate is significant for about six months on the import quantity of plywood in Korea. That is, if the interest rate change had an impact on the import quantity of plywood in Korea, it was only of a short-term nature.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.330-335
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• 2005

This study was performed for the analysis of the variation characteristics on riverbed according to the arrangement of stream. It was monitored of the variation progress of riverbed dependent on the elapsed time after the arrangement and It was studied that the hydraulic adjustment of the riverbed caused by the variation of the riverbed. The large amount of deposit just after the construction in which the riverbed was arranged to natural form was come from the reduction of flow rate by the installed artificialities such as weirs and stone weirs and by the stones or the concrete blocks attached to the stream sides of riverbanks. This phenomenon was well consistent with the usual characteristics that the accumulation is induced on upper stream of hydraulic artificialities and the erosion is induced on down stream of hydraulic artificialities. The large reduction of the deposit 1 year later after the construction showed that the riverbed eroded considerably because of the recovery of flow amount and the rise of flow rate.