• Korean Journal of Optics and Photonics
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• v.24 no.4
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• pp.184-188
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• 2013

Two types of polymer-based optical splitters with $200{\mu}m$ large core are presented for optical multimode networks, such as smart home networks, intelligent automotive networks, etc. Optical splitters that have 1:1 symmetric and 9:1 asymmetric structure were fabricated by a ultra violet(UV)-imprint technology using a deep etched Si(silicon) master by the Bosch process. In this paper, we successfully fabricated the symmetric and asymmetric optical splitters with suitable optical network applications.

• Clean Technology
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• v.20 no.2
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• pp.179-188
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• 2014

The effect of desorption pressure on $CO_2/N_2$ breakthrough behaviors for 4 different adsorbents was studied at a fixed bed. Zeolite 3A, 4A, 5A, and 13X pellets were used as adsorbents. Cyclic operations were executed with varying desorption pressure from vacuum (0 bar) to 3 bar while other conditions such as adsorption step pressure (3 bar), temperature (293 K), composition ($CO_2:N_2=10:90$vol%) and flow rate (400 ccm) were fixed at constant values. Each adsorption and desorption step was set as 80 min, which totaled up to 160 min per a cycle. 5 cycles with adsorption and desorption steps were run overall. After the experiment, breakthrough time, saturation time, and adsorption amount were measured and compared in order to find an optimum adsorbent and a proper operating condition for a post combustion $CO_2$ capture process.

• Korean Journal of Agricultural Science
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• v.26 no.2
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• pp.61-69
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• 1999

The water quality of river has been deteriorated mainly by both point source pollution and nonpoint source pollution from the watershed. Techniques to cut point source pollutants down to the level required have been developed. But, techniques of best management practices to catch the nonpoint source pollutions and to control the routine of pollutants were not successively developed. The quality of closed water system such as reservoir, lake and farm pond is irresistable to being polluted mainly by nonpoint source pollutions. In this study, the population, land use, runoff coefficient, amount of rainfall, and runoff discharge in the watershed were surveyed to investigate the characteristics of water quality such as BOD, COD, SS, T-N, and T-P. After studying the changes of water quality in the viewpoint of land use such as paddy land, residential area, upland, forest and meadow, load factors of nonpoint source pollutant were calculated in Bangdong reservoir watershed. Residential area was more severe than other land use as far as BOD, COD and SS concerned. T-N and T-P released from the paddy and upland were higher than other land use. The 45.9% of total load of nonpoint source pollution was occured during the rainy season.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.48-58
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• 1997

[ $CuInTe_2$ ] synthesised in a horizontal electric furnace was found to be polycrystalline. Single crystals of $CuInTe_2$ were grown with the vertical Bridgman technique. The photoconductivity and photoluminescence of the crystals were measured in the temperature range 20 to 293 K. From the photocurrent peaks measured for the samples both perpendicular and parallel to c-axis, the energy band gaps of the samples were found to be 0.948 eV and 0.952 eV at room temperature respectively. The energy difference of the photocurrent and photoluminescence peaks of the samples both perpendicular and parallel to the c-axis measured at room temperature was a phonon energy, and its values were 22.12 meV and 21.4 meV respectively. The splitting of the valence band due to spin-orbit and crystal field interaction was calculated from the photocurrent spectra of the samples, The ${\Delta}cr\;and\;{\Delta}so$ are 0.046,0.014 eV respectively.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.197-202
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• 1993

Polymyositis (PM) is a inflammatory connective tissue disease involving predominantly skeletal muscles, characterized by symmetrical, proximal muscle weakness, inflammation, and frequently, degeneration. Interstitial lung disease in association with PM occurs in 5~10% of cases and carries an especially grave prognosis. Although the cause of lung involvement in PM is not known, the underlying pathologic process in the lung is an immune mediated inflammation of alveolar structures, alveolitis. It is of interest, therefore, that cyclophosphamide, an immune modulating agent, has been reported to be effective in the treatment of PM. We report a case of corticosteroid resistant PM associated with interstitial lung disease, successfully treated with cyclophosphamide. A 37-year-old female was presented with 8 months duration of cough, exertional dyspnea, and muscle weakness. She had typical symptoms, physical findings, and elevated muscle enzyme levels in serum with characteristic findings of muscle biopsy. She also had typical interstitial lung disease pattern on chest X-ray and high resolution CT with restrictive pattern on pulmonary function test. The findings of transbronchial lung biopsy was compatible with interstitial lung disease. She failed to respond to corticosteroid initially. Subsequently steroids and cyclophosphamide were given with excellent clinical improvement.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1996-2000
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• 2010

국내 시설원예 면적은 2005년 기준 52,022ha에 달하고 있으며 약 23%에 해당하는 12,000ha는 겨울철에 난방기를 가동하여 원예작물을 생산하고 있다. 농업용 난방기의 보급은 가온재배 면적의 증가와 더불어 급신장하고 있어 농업용 면세유 중 경유 공급액 약 9,260억원 중 62%에 해당하는 1,350,000톤이 시설원예 난방에 사용된 것으로 추산되고 있다. 지속적인 유가 상승으로 시설재배 농가의 경영이 악화되고 있어 최근 히트펌프를 이용한 냉난방시스템에 대한 연구가 수행되고 있다. 시설원예 냉난방에 사용되는 히트펌프의 열원은 다양하게 적용할 수 있으나 강변에 위치하고 있는 시설원예단지의 경우 연 중 풍부한 유량과 안정적인 수온을 얻을 수 있는 강변여과수는 매우 매력적인 열원이다. 본 연구에서는 시범지역으로 남강댐 하류에 위치하고 있는 진주지역의 시설원예단지와 낙동강 유역의 구미지역 시설원예단지의 두 곳에 대하여 1일 $1,000m^3$의 강변여과수 개발에 대한 조사를 수행하였다. 육안 및 현장여건에 대한 조사를 수행하고 인근 지하수 사용현황에 대한 조사를 실시하였다. 진주지역의 경우 일부 농가에서 지하수를 사용하고 있었으나 1일 8~10시간 취수에 최대 취수량은 약 $120m^3$ 정도였다. 반면, 구미지역의 경우 1999년 구미첨단원예농단 조성사업의 일환으로 양액재배에 농업용수를 공급할 목적으로 지하수 개발이 실시되었으며 최근 인근 국화축제를 개최하는 지역에서 신규로 지하수를 개발하여 사용 중이었다. 전기비저항 탐사를 실시한 결과 진주지역은 지하 약 6~17m 지점에 대수층이 존재하는 것으로 판단되었고, 구미지역은 지하 약 10~20m 지점에 대수층이 존재할 가능성이 있지만 지하 20m 지점부터는 대수층의 가능성이 높은 것으로 판단되었다. 두 지역에 각각 두 공을 시추하여 조사한 결과, 구미지역의 경우 수면높이가 지하 약 10m이고 각각 2.5m와 4.6m의 모래자갈층을 형성하고 있어 $1,000m^3$/일의 취수량 개발이 원활하지 않을 것으로 판단되었다. 한편, 진주지역은 수면높이가 지하 약 3m이고 각각 3.5m와 6.5m의 모래자갈층을 형성하고 있어 $1,000m^3$/일의 취수량 개발이 가능할 것으로 판단되었다. 현장 시추조사 및 기존관정 조사결과, 구미지역에 비하여 진주지역이 지하수 물량 확보가 상대적으로 용이하고 신규 굴착 가능지점이 다수 분포하고 있어 연구지점으로 활용하는데 유리할 것으로 판단되었다. 따라서 진주지역에 여과수열원 확보를 위해 2곳의 양수관정을 설치하고 히트펌프를 이용하여 시설원예의 냉난방을 실시할 예정이다.

• Membrane Journal
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• v.27 no.6
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• pp.487-498
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• 2017

In this study, pervaporation performances of water/methanol and water/butanol mixture were evaluated using zeolite 4A membranes manufacutred by FINETECH by experimental works and numerical modeling. Permeation and separation characteristics, such as flux and separation factor, were analyzed by gas chromatography (TCD) and liquid nitrogen traps. Experiments have shown that water is selectively separated from a mixture of water and methanol (separation factor up to approximately 250) and water and butanol (separation factor up to approximately 1,500). Generalized Maxwell Stefan (GMS) theory was implemented to predict pervaporation behaviors of water/alcohol mixtures and diffusional coefficients of zeolite layer were obtained through parameter estimation using $MATLAB^{(R)}$ optimization toolbox. Since the pore size of zeolite 4A are much larger than kinetic diameter of water molecules and smaller than those of methanol and butanol, zeolite 4A membranes can be applied to in situ water removal process such as membrane reactors or hybrid reaction-dehydration process.

• Korean Journal of Materials Research
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• v.8 no.8
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• pp.693-698
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• 1998

The effects of $AI_{2}$$O_{3}$ and the ratio of $Na_2O/B_2O_3$ on the phase separation and optical properties of sodium borosilicate glass film fabricated by AFD(Aerosol Flame Deposition) were investigated. When AI,O, of 6wt% was added to $66SiO_2-27B_2O_3-7Na_2O$ the clear glass film without any crystallization was produced under air-quenching condition after consolidation. As the amount of $AI_{2}$$O_{3}$ increased from 1.5 to 6.0 wt% the refractive index linearly increased from 1.4610 to 1.4701, and the difference of TE and TM mode causing by residual stress in film increased gradually. However, the difference of TE and TM mode to reveal birefringence could be minimized by annealing below the glass transition temperature after consolidation and air quenching. On the other hand. as the ratio of $Na_2O/B_2O_3$ increased the refractive index and birefringence of glass film tended to increase, but the measurement of their values were not available at over the critical ratio of $Na_2O/B_2O_3$, because of the cloudiness due to crystallization. The phase separation was greatly accelerated with increasing the ratio of $Na_2O/B_2O_3$.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.204-211
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• 2018

In this study, densities of water + N-Methyldiethanolamine (MDEA), Water + 2-Amino-2-Methyl-1-Propanol (AMP), MDEA + AMP binary systems and Water+MDEA+AMP ternary system were measured over the full range of composition at temperatures from 303.15 K to 333.15 K by using an Anton Paar digital vibrating tube densimeter (DMA4500). The experimental excess volumes have been obtained from the experimental density results and have been fitted using the Redlich-Kister-Muggianu expression. The parameters obtained from the binary excess volume data were used for the correlation of ternary system with one additional ternary parameter for each isotherm. All investigated binary and ternary systems are completely miscible, because the values of excess volume are negative under the examined conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.137-146
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• 2005

IP-based design methodology has been popularly employed for SoC design to reduce design complexity and to cope with time-to-market pressure. Interface modules for communication between system buses and IPs are required, since many IPs employ different protocols. Automatic generation of these interface modules would enhance designer's productivity and IP's reusability. This paper proposes an automatic interface generation system based on FSM generated from the protocol description of IPs. The proposed system provides the library modules for the standard buses to reduce the burdens of describing the protocols for data transfer from/to standard buses. Experimental results show that the area of the interface circuits generated by the proposed system had been increased slightly by 4.5% on the average when compared to manual designs. In the experiment, where bus clock is 100 Mhz and slave module clock is 34 Mhz, the latency of the interface had been increased by 7.1% in burst mode to transfer 16 data words. However, occupation of system bus can be reduce by 64.9%. A chip designer can generate an interface that improves the efficiency of system bus, by using this system.