• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.89-95
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• 2004

The measured damping ratio was analysed to obtain amplitude dependence. Wind-induced vibration of 20 story steel-framed building was measured to investigate amplitude dependence by RD method. Micro-tremo vibrations of 20 RC bearing wall typed buildings were performed to analysis the amplitude dependence by formula proposed by Tamua and ESDU. Amplitude dependent damping in 17 story steel-framed building was showed clearly in the increasing rate of 9%. But Amplitude dependent damping of 17 RC bearing wall typed buildings was very low in the increasing rate of 2.5%. The tendency of dynamic properties of building obtained here are useful for the validation of dynamic properties of buildings in the evaluation of serviceability.

• Journal of ILASS-Korea
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• v.9 no.3
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• pp.8-14
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• 2004

Characteristics of droplet vaporization at high ambient pressures and temperatures which are supercritical conditions is studied numerically by formulating one dimensional vaporization model in liquid dodecane and air. Modified Soave-Redlich-Kwong state equation is used to condider real gas effect. Non-ideal behavior of properties at near critical and supercritical conditions is considered in the high pressure condition. Characteristic spatial distribution of properties with various conditions of pressure and temperature is evaluated in order to understand vaporizing evolution.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.2
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• pp.187-198
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• 1995

An aim of this study performs effective management of cultural properties by developing digital information system which unifies dualitied management system. This study used close range photogrammetry for acquisition of digital information and designed database using GSIS to join spatial and nonspatial data. The result of this study achives the high level management and provides quickly precise data.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.221-224
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• 2010

When the image registration methods which were generally used to the low medium resolution satellite images is applied to the high spatial resolution images, some matching errors or limitations might be occurred because of the local distortions in the images. This paper, therefore, proposed the automatic image-to-image registration of high resolution satellite images using local properties of control points to improve the registration result.

• Journal of the Korean Society of Safety
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• v.19 no.3 s.67
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• pp.20-25
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• 2004

In order to obtain the flame Propagation speed in freely falling droplet suspension Produced by an ultrasonic atomizer, a light collecting probe named Multi-color Integrated Cassegrain Receiving Optics (MICRO) is applied to spark-ignited spherical spray flames. Two MICRO probes are used to monitor time-series signals of OH chemilumine-scence from two different locations in the flame. The flame propagation speed is calculated by detecting the arrival time difference of the propagating flame front. In addition, time-series images of OH chemiluminescence are simultaneously obtained by a high-speed digital CCD camera to ensure the validity of the MICRO system. Furthermore, relationship between the spray properties measured by phase Doppler anemometer (PDA) and the flame propagation speed are discussed with k different experimental conditions by changing the fuel injection rate. It was confirmed that the MICRO probe system was very useful and convenient to obtain the flame propagation speed and that the flame propagation speed was different depending on the spray properties.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.469-471
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• 1988

The basic modeling is analyzed on the optoelectronic properties of CSP-DH laser structure using self-consistent calculation of optical field and the electron-hole distribution in the active region. Laser properties is modelled include gain profile, threshold, near field and far field pattern. This new characterization is allowed for consideration such as carrier spatial hole burning due to strong optical fields which stimulate recombination.

• Structural Engineering and Mechanics
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• v.31 no.5
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• pp.481-506
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• 2009

The present study is concerned with the stochastic linear free vibration study of laminated composite plate embedded with piezoelectric layers with random material properties. The system equations are derived using higher order shear deformation theory. The lamina material properties of the laminate are modeled as basic random variables for accurate prediction of the system behavior. A $C^0$ finite element is used for spatial descretization of the laminate. First order Taylor series based mean centered perturbation technique in conjunction with finite element method is outlined for the problem. The outlined probabilistic approach is used to obtain typical numerical results, i.e., the mean and standard deviation of natural frequency. Different combinations of simply supported, clamped and free boundary conditions are considered. The effect of side to thickness ratio, aspect ratio, lamination scheme on scattering of natural frequency is studied. The results are compared with those available in literature and an independent Monte Carlo simulation.

• Journal of Astronomy and Space Sciences
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• v.5 no.2
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• pp.123-127
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• 1988

Interplanetary scintillation is the fluctuation produced in the apparent brightness of a radio source, due to refractive effects in the apparent brightness of a radio source, due to refractive effects in the turbulent solar wind flowing from the sun. If this medium is illuminated coherently, analysis of the spatial and temporal properties of the radiation reaching the earth allows the stochastic properties of the medium to be understood. Here, a brief review of method of interplanetary scintillation to study solar wind behavior will be introduced.

• Journal of the Optical Society of Korea
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• v.20 no.5
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• pp.593-600
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• 2016

Operation properties, such as output power, beam radius, and crystal temperature rise were investigated in a diode-pumped edge-cooled monolithic Yb:YAG laser with ~ 4 W pumping level. The output power showed saturation behavior because of severe temperature rise and poor spatial overlapping between pump beam and lasing mode. Face cooling geometry by using a sapphire plate was also investigated. No apparent saturation behavior in output power was observed due to the reduced temperature rise, which could be attributed to efficient heat removal through the crystal-sapphire interface.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.121-146
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• 2000

A novel system of magneto-optical microscope magnetometer (MOMM), capable of simultaneous local problems of magnetic properties as well as real-time magnetic domain evolution imaging of ferromagnetic thin films with 400-nm spatial resolution, New findings in domain reveral dynamics of Co-based multilayers: The reversal ratio of V/R is a governing physical parameter. The activation volumes of wall-motion and nucleation processes are generally unequal. Submicron-scale local coercivity variation determines domain reversal dynamics. A thermally activated relaxation process during domain reversal is existed on the submicron-scale in realistic films. Local variation of magnetic properties should be considered for a realistic simulation. The fantastic capabilities of the MOMM can open many possibilities to broaden and deepen our understanding of domain reversal phenomena in ferromagnetic thin films.