• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.630-632
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• 2018

The compensation characteristics of the distorted WDM channels compensated for by dispersion management (DM) and optical phase conjugation in the long-haul (50 fiber spans ${\times}$ 80 km) transmission link with the randomly distributed single mode fiber (SMF) length and residual dispersion per spans (RDPS) for implementing of the flexible link configuration are investigated.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.633-635
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• 2018

The compensation characteristics of the distorted WDM channels compensated for by dispersion management (DM) and optical phase conjugation in the long-haul (50 fiber spans ${\times}$ 80 km) transmission link with the randomly distributed single mode fiber (SMF) length and residual dispersion per spans (RDPS) are investigated as a function of the arrangement of SMF and dispersion compensating fiber (DCF) and the control position of net residual dispersion (NRD).

• Journal of information and communication convergence engineering
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• v.5 no.4
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• pp.377-381
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• 2007

Nonlinear effects and chromatic dispersion are the main causes of pulse degradation in high bit-rate WDM transmission systems and several architectures have been proposed to compensate them by means of optical phase conjugation. In this paper, a new method to exploit an optical phase conjugator (OPC) for nonlinearity and dispersion cancellation is disclosed. The proposed method is using optimal total dispersion of each fiber sections and it is simpler than those previously described in literature. Power penalty between WDM channels and the maximum launch power in $28{\times}40$ Gbps WDM transmission system designed by optimal total dispersion are more decreased and more increased than those in the conventional WDM transmission system with OPC, respectively. Furthermore, optimal total dispersion proposed in this research should provide the flexible design of WDM system, which less depends on OPC position.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.4
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• pp.14-21
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• 1992

An optical novelty filter is implemented using photorefractive materal(BaTiO$_{3}$) as a recording materal and commercial liquid crystal TV as a spatial light polarization modulator. If a signal beam incident at the proper, the loop and the crossing angle inside th e crystal is formed to get maximum diffraction efficiency and BaTiO$_{3}$ as a self-pumped phase conjugation mirror show that phase conjugate reflectivity was 20 times as much as ordinary polarization if signal beam is extraordinary. In this paper, the stoke's theorem which is a reciprocal theorem for which is a reciprocal theorem for beam path is experimentally proved, and good output images were obtained with optical experiment of novelty filter which is formed by use of Michelson interferometer.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.967-970
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• 2014

The compensation characteristics are investigated as a function of the deviation of residual dispersion per span (RDPS) in the optical transmission links with a randomly distributed RDPS and optical phase conjugation (OPC). The simulation results show that the effective launch power are more increased and the effective net residual dispersions (NRDs) are more increased, as the deviation of RDPS is more narrow.

• Korean Journal of Optics and Photonics
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• v.21 no.4
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• pp.146-150
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• 2010

In this paper we have applied phase conjugated holographyto DHM (digital holography microscopy) to remove phase aberration and noise. Generally,digital holographyincludes the phase information of the object, phase aberration terms introduced by the measurement system and noise terms (DC term and twin images). These aberrations and noise terms decrease the quality of the reconstructed phase image. We could obtain a conjugated hologram which includes only phase information of object. Experimentally we show that distortion of image and aberration of phase in a measurement system are removed using the conjugation hologram.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.260-262
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• 2003

We report several difluoro isothiocyanato tolane-based liquid crystal (LC) singles having a high optical birefringence. Several eutectic mixtures are formulatd using these LC singles exhibiting a wide nematic phase range and high birefringence. We will report the physical properties of and photochemical stability of these new eutectic mixtures.

• Proceedings of the Korean Society of Laser Processing Conference
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• 2005.06a
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• pp.126-129
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• 2005

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.98-98
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• 1997

This study was done to investigate the effect of vitamin E on hypoxia/reoxygenation-induced hepatic injury in isolated perfused rat liver. Rats were pretreated with vitamin E or vehicle(soybean oil). Isolated livers from fasted 18 hours were subjected to 45min of low flow hypoxia or N$_2$ hypoxia followed by reoxygenation for 30min. The perfusion medium used was KHBB(pH 7.4) and 50${\mu}$㏖/$\ell$ of ethoxycoumarin was added to the perfusate to determine the ability of hepatic drug-metabolizing systems, In low flow hypoxia model, total glutathione and oxidised glutathione levels were significantly increased by hepoxia/reoxygenation with slight increase in LDH levels. These increases were prevented by vitamin E pretreatment. In N$_2$ hypoxia model, LDH, total glutathione and oxidized glutathione levels were increased significantly by hypoxia but restored to normal level by reoxygenation. Vitamin E had little effect on this hypoxic damage. There were no significant changes in the rate of hepatic oxidation of 7-EC to 7-HC in both hepoxic models. But, the subsequent conjugation of 7-HC by sulfate or glucuronic acid were significantly decreased by hypoxia, but restored by reoxygenation in both hypoxia models. As opposed to our expectation, treatment with vitamin E aggrevated the decrease of the rate of conjugation and even inhibited the restoration by reoxygenation. Our findings suggest that hypoxia/reoxygenation diminishes phase II drug metabolizing function and this is, in part, related to decreased energy level.

• Macromolecular Research
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• v.11 no.1
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• pp.14-18
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• 2003

Grafting of glycidyl methacrylate (GMA) upon coralline hydroxyapatite in conjugation with demineralized bone matrix (CHA-DBM) using equal molar ratio of potassium persulfate/sodium metabisulfite redox initiating system was investigated in aqueous medium. The optimum reaction condition was standardized by varying the concentrations of backbone, monomer, initiator, temperature and time. The results obtained imply that the percent grafting was found to increase initially and then decrease in most of the cases. The optimum temperature and time were found to be 50 $^{\circ}C$ and 180 min, respectively, to obtain higher grafting yield. Fourier transform infrared (FT-IR) spectroscopy and X-ray powder diffraction (XRD) method were employed for the proof of grafting. The FT-IR spectrum of grafted CHA-DBM showed epoxy groups at 905 and 853 $cm^{-1}$ / and ester carbonyl group at 1731 $cm^{-1}$ / of poly(glycidyl methacrylate) (PGMA) in addition to the characteristic absorptions of CHA-DBM, which provides evidence of the grafting. The XRD results clearly indicated that the crystallographic structure of the grafted CHA-DBM has not changed due to the grafting reaction. Further, no phase transformation was detected by the XRD analysis, which suggests that the PGMA is grafted only on the surface of CHA-DBM backbone. The grafted CHA-DBM will have better functionality because of their surface modification and hence they may be more useful in coupling of therapeutic agents through epoxy groups apart from being used as osteogenic material.