• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.527-534
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• 2001

Conventional stereo image acquisition uses a pair of frame grabbers in the CAS(Computer Assisted Surgery) system. In this Paper, we developed a synchronized stereo image acquisition method with only one frame grabber Two images from left and right camera each other. were merged with different color space without time delay and thus only one frame grabber was enough toy stereo image. Due to this synchronous Property of image acquisition, we can improve spatial revolution on the computation of 3D Position. Furthermore the overall costs for 3D navigator can be down and the extraction time of stereo Position tan be shortened.

• Electrical & Electronic Materials
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• v.9 no.1
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• pp.44-50
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• 1996

In this study, Selenium device was fabricated by vacuum evaporation method with the substrate temperature at room temperature and its electrical and optical properties were investigated to be used in optical device. The film properties largely depended on the transmittance and annealing time, and improved with aging owing to stress release. We found that the photocurrent of the films increase linearly with light illumination. As a result, Selenium device made by this method yielded a short circuit current density of 10.5mA/$\textrm{cm}^2$, an open circuit voltage of 39OmV.

• Transactions on Electrical and Electronic Materials
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• v.14 no.2
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• pp.82-85
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• 2013

This paper introduces 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) doped liquid crystal (LC) alignment properties on a rubbed polyimide (PI) layer as a function of the doping concentration of TIPS pentacene. Pretilt angles, photomicrographs, and electro-optical properties of TIPS pentacene doped LCs were comparable to those of pure LCs. However, TIPS pentacene in a LC medium supported twisted nematic-liquid crystal displays (TN-LCDs) to improve electro-optical properties. The threshold voltages observed in the TN cells decreased as the TIPS pentacene concentration increased. In addition, suitable response times were observed in TN cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.176-179
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• 2003

ITO films on PET substrate were prepared by DC magnetron sputtering method using powdery target with different deposition conditions. In addition, the electrical and optical properties were investigated. As the sputtering power and working pressure were higher, the resistvity of ITO films increased. The optical transmittance deteriorated with increasing sputtering power and thickness. As the working pressure increased, however, the optical transmittance improved at visible region of light. From these results, we could deposited ITO films with $8{\times}10^{-3}\;{\Omega}-cm$ of resistivity and 80% of transmittance at optimal conditions.

• Korean Journal of Optics and Photonics
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• v.12 no.2
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• pp.98-102
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• 2001

To analyze the saturating process of $Cr^{4+}:YAG$ crystal and plastic organic dye as the saturable absorber, we have measured the residual optical losses between a free running and a passive Q-switching mode for various optical densities. The undepleted ground state population density and the saturated transmission of the saturable absorber have been evaluated by the additional optical losses with the increased threshold pump energies between two resonators. ill the passive Q-switching mode, the saturable transmission of saturable absorber is less than the maxrnium saturable transmission due to the undepleted ground state population density. nsity.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.33-38
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• 1999

To investigate the image-forming property of optical system having Gaussian amplitude for polychromatic source, we calculated the chromaticity variation and the illuminance distribution. Considered polychromatic sources in this paper are A light which is on incandescent-tungsten lamp, C light which is a daylight, and $D_{65}$ light which is a extend daylight to the near ultraviolet. The polychromatic sources represent the different chromaticity values at a geometrical image point. The chromaticity variation of optical system having a Gaussian amplitude is smaller than that having an uniform amplitude. The illuminance distributions for polychromatic sources present nearly the same values, and the depth of focus for optical system having a Gaussian amplitude is wider than that having an uniform amplitude. From these results, we know that the depth of focus increases and the chromaticity variation decreases, when the incident light amplitude is modulated from an uniform amplitude to a Gaussian amplitude.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.71-77
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• 2014

Despite the ubiquity of electronic media, paper is still the most generally readable carrier of information. Because paper materials are deteriorated by chemical, biological and physical factors over time, there have been major concerns about the decay of large collections of books, publications, old maps, historical artifacts, and written records. Therefore, manufacture of permanent paper has been a highly debated issue in paper conservation research. Through the use of permanent paper, our new records, journals, library books, art works, and all culturally and historically important documents can be preserved. In this study, handsheets were made of mixture of hemp bast fiber produced by soda pulping and HwBKP varying the amount of hemp. Physical, mechanical and optical properties of each handsheet were examined. As the ratio of hemp bast fiber increased, mechanical properties were improved significantly, but opacity decreased. After aging, the optical properties of the handsheets mixed with the hemp bast fiber more decreased than those of the non-mixed handsheet. The more mixture ratio of hemp bast fiber increased, the more decreasing rate of optical properties increased. As a result, it was confirmed that hemp bast fiber is a very promising resource for the manufacturing of permanent paper.

• Journal of the Korean Ceramic Society
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• v.39 no.9
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• pp.835-839
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• 2002

Stoichiometric $LiNbO_3$(LN) single crystals of 1 mm diameter and 30∼40 mm length with co-doped the $Er_2O_3$ and MgO were grown by the Micro-Pulling Down(${\mu}$-PD) method. The grown crystals were investigated for the change of the up-conversion property by the $Er_2O_3$ and MgO addition and the optical damage by the MgO concentration. Also, the crystals were studied the defects using the optical microscope and it is identified the homogeneities of the distribution of the $Er_2O_3$ and MgO concentration by the Electron Probe Micro Analysis(EPMA).

• Korean Journal of Materials Research
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• v.27 no.6
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• pp.345-349
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• 2017

The effects of electron beam(EB) irradiation on the electrical and optical properties of InGaZnO(IGZO) thin films fabricated using a sol-gel process were investigated. As the EB dose increased, the electrical characteristic of the IGZO TFTs changed from semiconductor to conductor, and the threshold voltage values shifted to the negative direction. X-ray photoelectron spectroscopy analysis of the O 1s core level showed that the relative area of oxygen vacancies increased from 14.68 to 19.08 % as the EB dose increased from 0 to $1.5{\times}10^{16}electrons/cm^2$. In addition, spectroscopic ellipsometer analysis showed that the optical band gap varied from 3.39 to 3.46 eV with increasing EB dose. From the result of band alignment, it was confirmed that the Fermi level($E_F$) of the sample irradiated with $1.5{\times}10^{16}electrons/cm^2$ was located at the closest position to the conduction band minimum(CBM) due to the increase of electron carrier concentration.

• Current Applied Physics
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• v.18 no.12
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• pp.1465-1472
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• 2018

The magnetic and optical properties of Ce-doped ZnO systems have been widely demonstrated, but the effects of different strains of Ce-doped ZnO systems remain unclear. To solve these problems, this study identified the effects of biaxial strain on the electronic structure, absorption spectrum, and magnetic properties of Ce-doped ZnO systems by using a generalized gradient approximation + U (GGA + U) method with plane wave pseudopotential. Under unstrained conditions, the formation energy decreased, the system became stable, and the doping process became easy with the increase in the distances between two Ce atoms. The band gap of the systems with different strains became narrower than that of undoped ZnO without strain, and the absorption spectra showed a red shift. The band gap narrowed, and the red shift became weak with the increase of compressive strain. By contrast, the band gap widened, and the red shift became significant with the increase of tensile strain. The red shift was significant when the tensile strain was 3%. The systems with -1%, 0%, and 1% strains were ferromagnetic. For the first time, the magnetic moment of the system with -1% strain was found to be the largest, and the system showed the greatest beneficial value for diluted magnetic semiconductors. The systems with -3%, -2%, 2%, and 3% strains were non-magnetic, and they had no value for diluted magnetic semiconductors. The ferromagnetism of the system with -1% strain was mainly caused by the hybrid coupling of Ce-4f, Ce-5d, and O-2p orbits. This finding was consistent with Zener's Ruderman-Kittel-Kasuya-Yosida theory. The results can serve as a reference for the design and preparation of new diluted magnetic semiconductors and optical functional materials.