• Korean Journal of Optics and Photonics
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• 제5권2호
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• pp.298-303
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• 1994

Microlens arrays are fabricated by melting "islands" of thick photoresist on a glass substrate. Microlenses with diameters $25\mu\textrm{m}$, $50\mu\textrm{m}$, $100\mu\textrm{m}$are made. Their surface profiles are obtained by a scanning electron microscope and a mechanical surface profilometer. The wavefront of the microlenses is measured by phase-shifting techniques using a Mach-Zehnder-like configuration. Thereby wavefront errors, focal lengths. point spread functions are obtained. The microlens with the diameter of $100\mu\textrm{m}$ has focal length of $164\mu\textrm{m}$ and spot diameter is less than $5\mu\textrm{m}$..

• Journal of the Korean Ceramic Society
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• 제41권3호
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• pp.197-201
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• 2004

SiO$_2$ and SiON thick films were deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique on silicon wafer (100) using SiH$_4$ and $N_2$O as precursor gases. In this work, the influence of rf power, and rf bias power on the optical and physical properties of SiO$_2$ and SiON thick films is presented. The refractive index decreases with increasing rf power, and rf bias power. The refractive index of the films varied from 1.4493 to 1.4952 at wavelength at 1552 nm, with increasing rf power, the nitrogen content decreases while the oxygen content increases, in a manner that the O/N ratio increases approximately linearly.

• Korean Journal of Materials Research
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• 제11권5호
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• pp.385-392
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• 2001

There have been many investigations and researches on PLC type of optical amplifiers because they are convenient for mass production and also can integrate multi-functional devices into a single chip. In this research. the fabrication of optical waveguide made of Si/$Sio_2$ by FHD(Flame Hydrolysis Deposition) for passive integrated optical devices and $1.5\mu\textrm{m}$ optical amplifier by Solution Doping method, which is one of the method doping $Er^{3+}$ into the thin film, are mainly discussed.

• Journal of Pharmaceutical Investigation
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• 제38권6호
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• pp.399-403
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• 2008

The aim of this study was to evaluate the difference of analytical methods for the pharmacokinetic study of bromosulfophthalein (BSP), an indicator of hepatobiliary function. The plasma and bile concentrations of BSP after intravenous administration were measured according to custom UV spectroscopy and HPLC, respectively. Plasma concentration of BSP measured by UV spectroscopy was similar to that measured by HPLC. There was no significant difference in the distribution volume, total body clearance, area under the curve and mean residence time of BSP between different analytical method groups. However, bile concentration of BSP measured by UV spectroscopy was overestimated compared with concentration measured by HPLC method. Biliary clearance of BSP obtained from UV spectroscopy method was almost 3 times higher than that obtained from HPLC method. Thus, a feasibility of UV spectroscopy method for high throughput pharmacokinetic evaluation of BSP was limited to the study based on the plasma concentration of BSP, not bile concentration.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제4권1호
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• pp.100-104
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• 1994

KTP seed crystals were grown by the hydrothermal method and the properties of grown crystals were investigated by means of infrared spectrophotometer. The hydrothermal conditions for high growth rates of seed crystals are as follows: temperature ranges, between , $430 and 450^{\circ}C $ ; hydrothermal solvent, 4m KF solution ; temperatures difference, $30<{\triangle}T<65^{\circ}C$ ; filling %, 65% ; growth method, vertical temperature gradient method. Under these conditions, morphologies of the grown KTP single crystals tended to be bounded by (100), (011) and (201) faces and hydroxyl groups were observed in the grown crystals.

• Journal of the Korean Institute of Telematics and Electronics D
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• 제35D권1호
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• pp.84-93
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• 1998

Planar graded index optical waveguides have been formed by Ag$^{+}$ ion exchange in the BK7 optical glass. The experimental results of diffusion and modal characteristics of Ag$^{+}$-Na$^{+}$ exchanged BK7 glass waveguides are presented. Measurements of the mode indices have been measured. We found the relations between the process and device parameters such as the diffusion depth and the square root of the diffusion time, diffusion coefficient and diffusion temperature, and diffusion ion concentration and surface index change. A theoretical gaussian function refractive index profile matched best with the measured data for all the guided modes. The empirical relations between the process and the device parameters are derived and subsequently used to formulate a systematic procedure for fabricating singlemode and multimode waveguides.uides.

• Journal of Pharmaceutical Investigation
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• 제2권1호
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• pp.14-17
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• 1972

Spectrophotometric determination of isonicotinic acid hydrazide sodium methane sulfonate was examined and a new method has been established. Isonicotinic acid hydrazide sodium methane sulfonate reacts with acetylacetone solution (NASH Reagent) to produce a yellow dye, which exhibits absorption maximum at about $412\;m{\mu}$. Limits of masurement of isonicotinic acid hydrazide sodium methane sulfonate was $20-100{\mu}g/ml$. By this method isonicotinic acid hydrazide methane sulfonate can be determined in the presence of isonicotinic acid hydrazide.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제26권11호
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• pp.1481-1487
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• 2002

The thin SiC filament technique has been employed to identify the possibility of measuring flame temperature, and especially unstable near-extinction flame temperature in an oxidizer deficient ambience, by comparing the relative visible (non-IR) luminosities of SiC filaments with thermocouple measured temperature in co-flowing, laminar propane/air diffusion flames. The results show good agreement between the digitized relative visible luminosity profiles of the SiC filaments and temperature profiles measured using a thermocouple at temperatures above $700^{\circ}C$, although, a non-linear calibration is probably required far the whole temperature range. The highest radial peak temperature exists near to the nozzle exit. and the centerline temperatures were virtually unchanged with increasing flame height in an oxidizer deficient near-extinction flame.

• Proceedings of the IEEK Conference
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.323-326
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• 1999

This paper describes a point matching method that is based on an expansion of the electromagnetic field in terms of a series of Bessel and modified Bessel functions multiplied by trigonometric functions. In this method, the electric and magnetic fields inside the waveguide core are matched to those outside the core at matching points on the boundary to yield matrix equations. As an example applying this method, the paper presents the results of the computation in the form of curves of the propagation constants in a semicircular optical waveguide, be formed by annealing for reduced insertion(radiation) loss when connected to optical fiber. The propagation curves are presented in a form of refractive index independent. Also, it presents relative energy distributions between inside the core and outside the core of various modes and presents field distributions.

• The Bulletin of The Korean Astronomical Society
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• 제35권1호
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• pp.55.1-55.1
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• 2010

대마젤란 은하에 속한 식쌍성의 시선속도 곡선을 완성하기 위하여 2009년 11월 칠레에 위치한 Cerro Tololo Inter-American Observatory (CTIO)의 1.5m 망원경과 R-C Spectrograph를 사용하여 중 분산 분광관측을 수행하였다. 분광관측은 380nm - 540nm 영역에서 $H_8,\;H_{\varepsilon},\;H_{\delta},\;H_{\Gamma},\;H_{\beta}$ 등의 흡수선을 관측하였다. 중분산으로 관측된 식쌍성의 각 구성원별에서 나오는 흡수선들은 구별되지 않으므로 이를 구별하기 위하여 구성원들의 Flux 비와 함께 gauss curves fitting 방법으로 각 흡수선들을 2개의 성분으로 분해하여 시선속도를 측정하고, 시선속도곡선을 완성하였다. 완성된 이중 시선속도 곡선은 Wilson & Devinney 차등 보정법으로 분석하여, 궤도 장반경, 질량비, 계의 시선속도 등을 구하였다. 또한 각 식쌍성들의 광도곡선을 분석하여 측광학적인 해를 구하고, 최종적으로 분광 및 측광관측의 해를 혼합하여 대마젤란은하 식쌍성들의 절대량을 구하였다. 이후 이를 바탕으로 거리를 구하여 기존에 발표된 마젤란은하의 거리와 비교하였다.