• Journal of the Korea Society of Computer and Information
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• v.17 no.7
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• pp.53-65
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• 2012

Existing method of creating Stereoscopy image, creates viewpoint image from the left and right by shooting one object with 2 lens in certain distance. However, in case of 3-D TV using Stereoscopy camera, the necessity to transmit 2 viewpoint images from the left and right simultaneously, increases the amount of bandwidth. Various and more effective alternatives are under discussion. Among the alternatives, DIBR(Depth Image Based Rendering) creates viewpoint images from the left and right using one image and its Depth information, thus decreasing the amount of transmitted bandwidth. For this reason, there have been various studies on Algorithm to create DIBR Image in existing Static Scene. In this paper, I would like to suggest Gaussian Hole-filling solution, which utilizes reverse-depth image to fill the hole naturally, while minimizing distortion of background. In addition, we have analyzed the effectiveness of each Algorithm by comparing and calculating its functions.

• Journal of the Korean Magnetics Society
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• v.23 no.5
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• pp.154-158
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• 2013

We have analyzed the magnetization curves measures by using VSM and MOKE in synthetic antiferromagnetic coupled CoB/Ru/CoB thin film. The measured results were compared with calculated ones by Stoner-Wohlfarth model based on the magnetization behavior of two ferromagnetic layers ($M_1$, $M_2$). The calculated total magnetization ($M_{tot}=M_1+M_2$) and single layer magnetization($M_1$) behaviors were compared with measured results by using VSM and MOKE, respectively. The total magnetization curve ($M_{tot}=M_1+M_2$) showed reversible magnetization behavior with flopping field of about 50 Oe. While single layer magnetization ($M_1$) behaviors showed irreversible magnetization behavior in the field range of $H_F$ < H < $H_F$. These magnetization behaviors were explained by the angle difference between magnetization directions of two ferromagnetic layers in SAF sample.

• 한국지구물리탐사학회:학술대회논문집
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• 2006.06a
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• pp.181-186
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• 2006

An imaging method of seismic sources using time-reversal wave propagation is presented. The method is based on the time-reversal invariance and the spatial reciprocity of the wave equation. Time-reversal wave propagation has been used to image anomalous features of a midium in medical imaging, non destructive testing and waveform tomography. Seismogram is the record whose energy is propagated from the seismic source. If time-reversed seismogram propagates back into the medium, seismic energy is concentrated at the origin time of the event and at the source location. In this work, a staggered-grid finite-difference method of the elastic wave equation is parallelized for 3-D wave propagation simulation. With numerical experiments, we show that the time-reversal imaging will enable us to explore the spatio-temporal history of complex earthquake.

• Journal of Sericultural and Entomological Science
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• v.18 no.2
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• pp.1-60
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• 1976

In present study, radioautography and electron-microscopy were applied by the author to the elucidation of the mechanism of diapause in Bombyx mori L. (1). Patterns of nucleic acid and protein syntheses during embryonic development of silkworms, incubated at high and at low temperatures, were demonstrated by means of radioautography with labelled precursors of nucleic acid and protein. On the third day after blastokinesis the embryo incubated at high temperature generally incorporated much of the $^3$H-glycine into the brain and the suboesophageal ganglion, and some into other regions. When incubated at low temperature, no difference in the pattern between the brain, the suboesophageal ganglion and other parts was observed. Radioautography with $^3$H-thymidine revealed no significant difference in DNA synthesis in embryos incubated at high and low temperatures. In diapausing eggs twenty days after deposition, only a few cells of the mesoderm incorporated the labelled material into their nuclei, but in the hibernated eggs all the nuclei of the mesoderm had thymidine incorporation. After blastokinesis only the anterior portion of the embryo around the brain and the suboesophageal ganglion had thymidine incorporation; this was not observed in the posterior portion.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.943-953
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• 2007

In this paper, we propose a Cassegrain antenna with a scalar feed horn opt rating in Ka-band. For an effective EM simulation of the Cassegrain antenna, the near-field of the feed hone is used ai the equivalent source of the Cassegrain antenna using the surface equivalent theorem. A corrugated circular horn operating with $HE_{11}$ mode is used as the feed horn. The angle and feed center of the main and sub reflectors are optimized to achieve maximum antenna efficiency. The designed feed horn shows the gain of 19dBi, the side-lobe level of less than -25dB and the half power beam width of $20^{\circ}$ at 33 GHz. The Cassegrain antenna shows the gain of 41dBi, the efficiency of 60%, the side-lobe level of less than -20dB and the half power beam width of $1.2^{\circ}$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.560-567
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• 2011

In this paper, we reduced the optical noise interference using polarizers in a visible light communication system. In a transmitter, two light-emitting diodes(LEDs) are modulated synchronously by the original and the reversed signals of the transmitted data, and the two LED lights are radiated through orthogonal polarizers. In a receiver, two optical signals are detected through orthogonal polarizers and differentially amplified to remove the optical noise. In an environment that noise light from a fluorescent lamp is much stronger than the signal, the receiver with orthogonal polarizers removed the 120 Hz noise, and synchronous light transmission of the original and the reversed signals using two LEDs reduced the illumination flickering to about one-eighth that using one LED.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.22-29
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• 2002

Usually, much harmonics are included and cause harmonic loss of motor, torque pulsation, electro-magnetic noise and shock etc. by switching function of inverter when drive induction motor variableness inside. It applied partial resonant Buck converter and three phase voltage type SPWM inverter circuit to induction motor driving system in this paper that see to solve such problem. Changed operation condition variously to do input current of circuit that propose sine-wave by unit power factor almost and capacitor supplied bringing back to life voltage by power supply arranging properly assistance diode and electric power switching. Power factor and efficiency improved as that minimize variation of input at power supply voltage polarity reverse by that add voltage reversal function. Also, by using output filter, reduced harmonic of output line to line voltage components, and introduce state space analysis and forecast operation of rectifier. Such all items confirmed validity through simulation and an experiment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.861-868
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• 2017

Near band infrared imaging technique has adopted for imaging EL2 and shallow level distributions in undoped semi-insulating LEC GaAs. This technique, which relies on the mapping of near bandgap infrared transmission, is both rapid and non-destructive. Until now no quantitative analysis has been reported for near band edge region which gives the reverse contrast on EL2 absorption images. This paper presents the spectral, spatial and temperature dependence of photoquenching forward and inverse mechanism in the band edge domain for cells and walls and for direct and inverted contrast conditions during transitory regimes. The difference in the threshold for the EL2w and EL2b defects could be attributed to the contribution of a different electrical assistance due to a different species of impurities. Quantitative analysis results show an increased density of EL2w and a small reduction of EL2b in the region of the walls where there is a high density of dislocations.

• Journal of the Korean Geotechnical Society
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• v.18 no.3
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• pp.73-85
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• 2002

This paper is focused on studying the undrained cyclic triaxial behavior of saturated Nak-dong River sand, using anisotropically consolidated specimens. A test of isotropically consolidated specimens was performed to compare the results of the anisotropically consolidated specimens. The cyclic shear stre3ngth of the sand under various combinations of initial static shear stress and relative density was considered. Failure was defined as a 5% double amplitude cyclic strain and a 5% residual axial strain for both reversal stress and no reversal stress conditions. Using this definition, the cyclic strength of the anisotropically consolidated specimens was affected by the initial static shear stress. For anisotropically consolidated Nak-dong River dense sand, the cyclic strength is greater than that of Toyolura silica sand but is smaller than that of Dogs Bay carbonate sand. By comparing the experimental and predictecl results, it was possible to predict the residual pore pressure of Nak-dong River sand using Hyodo's model with initial static shear stress subjected cyclic loading.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.6
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• pp.917-926
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• 1999

In this paper, the recording device for measuring the magnetic field waveforms associated with the cloud lightning discharges was made by the loop-type magnetic field sensor, and the measuring system of a distance between lightning stroke point and observatory site was proposed. The parameters including the time interval of superimposed pulses, zero-to-zero crossing time and the percentage depth of the dip for the positive and the negative magnetic field waveforms were statistically analyzed as a function of the distance between the lightning discharge point and the observatory site. The results could be summarized as follows; Several superimposed pulses were observed at the initial front part of the magnetic field waveform produced by cloud lightning discharges, and the mean time interval between superimposed pulses was about $4\mu\textrm{s}$. Also, the bipolar characteristic appeared significantly and the percentage depth of the dip was about 57~65%. It was known that the zero-to-zero crossing time of the electromagnetic fields is gradually decreased as a distance between lightning discharge point and observatory site is increased.