• 한국통신학회논문지
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• 제29권5A호
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• pp.473-483
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• 2004

8 채널 ${\times}$ 40 Gbps 파장 분할 다중 (WDM ： Wavelength Division Multiplexing) 시스템에서 색 분산과 자기 위상 변조에 의해 왜곡된 광 펄스를 최상으로 보상할 수 있는 광 위상 공액기 (OPC : Optical Phase Conjugator)의 최적 펌프 광 전력을 채널 입력 전력 변화에 따라 수치 해석적으로 살펴보았다. 또한 OPC의 펌프 전력 변화에 따른 수신단에서 허용 가능한 채널의 최대 입력 전력 크기를 변조 파형 형식, 광섬유 분산 계수에 따라 살펴보았다. 본 논문에서 고찰한 WDM 시스템은 전체 전송 링크 중간에 HNL-DSF (Highly- Nonlinear Dispersion Shifted fiber)를 비선형 매질로 이용한 OPC를 두어 보상하는 경로 평균 강도 근사 (PAIA ： Path-Averaged Intensity Approximation) MSSI (Mid-Span Spectral Inversion) 기법에 기초를 두고 있다. 우선 최소의 눈 열림 패널티를 만드는 HNL-DSF On의 특정 펌프 광 전력의 크기는 변조 파형 형식, 초기 채널 입력 전력, 총 전송 거리, 광섬유분산 등의 복합적인 영향에 따라 다소 변화될 수는 있지만 전력 변환비를 1 근처로 만드는 값에서 결정되어야 한다는 것을 알 수 있었다. 또한 HNL-DSP OPC의 펌프 광 전력이 최소의 EOP를 결과하는 최적의 값이 아닌 다른 값으로 설정되어 있는 경우 양호한 수신을 가능하게 하는 채널의 최대 입력 전력 크기는 광섬유의 분산 계수가 비교적 적은 WDM 시스템에서 변조 파형 형식으로 NRZ보다 RZ를 사통하면 더욱 증가되는 것을 확인할 수 있었다.

• 한국의류학회지
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• 제36권4호
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• pp.412-421
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• 2012

The yerba mate that grows in the subtropical forests of South America is an evergreen tree within the Aquifoliaceae family. The yerba mate (Ilex paraguariensis) tea is habitually used as a drink in Argentina, Paraguay, Uruguay, and Southern Brazil. A wild mate tree needs about 25 years to fully grow to 15 a height of meters; however, they only grow to a height of 3-5 meters when cultivated. The leaves are 7-11 cm long and 3-5cm wide with a serrated margin. Yerba mate tea-based beverages are made from the leaves and stems of the mate tree. It is known that they contain a rich content of antioxidants and polyphenol, vitamins, amino acids, minerals and colorants. Dyeing properties of a mate plant in the silk, wool, linen and cotton fabrics were investigated. Constituents of colorant of mate tea are chlorophyll and carotinoid; in addition, it has more minerals such as (Fe, Ca, Mn, Mg, Na, K, Zn, and Cu) than green tea. Mate tea colorants showed good affinity to silk and wool fabrics. It was found that the optimum condition for dyeing was 30 minutes for dyeing time, 7 for pH of dyebath, and at a dyeing temperature of $80^{\circ}C$. The maximum absorbance wavelength (${\lambda}_{max}$) of silk and wool fabrics dyed with mate tea were at 420-440nm; however, that of linen and cotton fabrics were at 400nm. K/S values of fabrics dyed under optimum conditions were 1.979 for silk fabrics, 1.541 for wool fabrics, 0.551 for linens and 0.465 for cotton fabrics. Munsell hue values of dyed fabrics measured 3.1Y-6.4GY for silk, 1.4Y-8.3Y for wool, 5.5Y-3.7GY for linen, and 5.3Y-1.3GY for cotton. All dyed fabrics showed hues in-between greenish yellow and greenyellow. Colorfastness to rubbing, perspiration and dry-cleaning of dyed fabrics with mate tea were very good; however, the grades of colorfastness to washing of dyed linen and cotton fabrics were poor, and colorfastness to light were poor.

• Bulletin of the Korean Chemical Society
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• 제33권9호
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• pp.3055-3060
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• 2012

A simple, rapid and sensitive spectrofluorometric method was developed for the determination of folic acid (FA), based on its quenching effect on the fluorescence intensity of enoxacin (ENX)-europium ($Eu^{3+}$) complex as a fluorescent probe. Fluorometric interaction between ENX-$Eu^{3+}$ complex and FA was studied using UV-visible and fluorescence spectroscopy. The quenched fluorescence intensity at an emission wavelength of 614 nm was proportional to the concentration of FA. Optimum conditions for the determination of FA were investigated. Under optimal conditions, the reduced fluorescence intensity at 614 nm was responded linearly with the concentration of FA. The linearity was maintained in the range of $1.25{\times}10^{-9}$ to $1.50{\times}10^{-7}$ M (R = 0.9986) with the limit of detection ($3S_b/m$) (where $S_b$ is the standard deviation of blank and m is the slop of linear calibration curve) of $6.94{\times}10^{-10}$ M. The relative standard deviation (RSD) for 9 repeated measurements of $1.0{\times}10^{-9}$ M FA was 1.42%. This method was simple, cost effective, and relatively free of interference from coexisting substances. Successful determinations of FA in pharmaceutical formulation and biological samples with the developed method were demonstrated.

• 한국염색가공학회지
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• 제21권3호
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• pp.10-18
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• 2009

Dyeing process of the natural indigo powder onto ramie and silk fabrics was investigated by using glucose and calcium hydroxide as a reducing system. Effect of reduction and dyeing conditions such as temperature and time of reduction/dyeing, and concentrations of glucose and calcium hydroxide on the dyeing process were explored. Indigo powder was obtained by drying the conventional niram paste in an oven at $50^{\circ}C$. Color strength of the dyed fabrics was evaluated by K/S value measured at the wavelength of maximum absorption(${\lamda}$max). Munsell color coordinates(H V/C) were used to compare fabric colors of ramie and silk. Ramie fabric showed purple-blue color for all the temperature and time. On the contrary, silk fabric showed wide range of color including brown, brown-green, green at the different temperature. With the increase of K/S value, the coordinate of value(lightness) decreased for both of ramie and silk fabrics. The coordinate of hue(shade) changed drastically with the increase of K/S value for silk fabric, compared with that of ramie fabric which showed nearly constant value at the whole range of K/S value. Optimum concentrations of calcium hydroxide were for 6 g/L for ramie and 4 g/L for silk at $60^{\circ}C$ and 50 min. K/S value increased with the indigo concentration. Maximum K/S value was shown at $10{\sim}12$ g/L of glucose concentration. For both of ramie and silk fabrics, the colorfastness of washing and light was lower than that of rubbing. All the colorfastness values were improved with the increase of color strength.

• 한국재료학회지
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• 제22권3호
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• pp.145-149
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• 2012

Red phosphors of $Gd_{1-x}Al_3(BO_3)_4:{Eu_x}^{3+}$ were synthesized by using the solid-state reaction method. The phase structure and morphology of the phosphors were measured using X-ray diffraction (XRD) and field emission-scanning electron microscopy (FE-SEM), respectively. The optical properties of $GdAl_3(BO_3)_4:Eu^{3+}$ phosphors with concentrations of $Eu^{3+}$ ions of 0, 0.05, 0.10, 0.15, and 0.20 mol were investigated at room temperature. The crystals were hexagonal with a rhombohedral lattice. The excitation spectra of all the phosphors, irrespective of the $Eu^{3+}$ concentrations, were composed of a broad band centered at 265 nm and a narrow band having peak at 274 nm. As for the emission spectra, the peak wavelength was 613 nm under a 274 nm ultraviolet excitation. The intensity ratio of the red emission transition ($^5D_0{\rightarrow}^7F_2$) to orange ($^5D_0{\rightarrow}^7F_1$) shows that the $Eu^{3+}$ ions occupy sites of no inversion symmetry in the host. In conclusion, the optimum doping concentration of $Eu^{3+}$ ions for preparing $GdAl_3(BO_3)_4:Eu^{3+}$ phosphors was found to be 0.15 mol.

• 기술사
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• 제17권4호
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• pp.28-39
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• 1984

Experiments were carried out for the development of a processing method of soybean into full-fat or defatted flour, using two varieties of soybean (kwangkyo produced in Korea and Bragg produced in India) Samples were subjected to dry dehulling, size reduction and wet heat treatment processes to make soybean flours. The quality of soybean flours were evaluated, and the results obtained were summarized as follows. 1. Crude fiber content of dehulled soybean was under 3.0% which indicated satisfactory dehulling, and there was no significant difference in crude fibre content between two varieties. 2. When dehulled soybean was cracked into soy grits by a hammer mill, 98.71∼98.86％ of the soy grit was in the range of 10∼18 mesh which was the optimum size of particle for quick and uniform penetration of heat into the intra-particle air spaces. 3. Moisture content of soy flour after steam treatment at 15 psig for 5 to 30 min was only 0.29∼1.68% which did not hinder the next milling operation. 4. From the color analysis of soy flours, it was observed that the dominant wavelength for all the samples are in a very narrow range from 575 to 581 nm and the color variation was from yellow to yellowish orange. Twenty to twenty five ％ higher reflectance was observed in the defatted flours than full fat flours. The ％ chroma of the defatted flour slightly increased as the duration of steaming of soy grits increased, whereas that of the full-fat flour did not. 5. The protein extractability in the defatted flour at pH 7.6 showed progressive decrease in solubility from 48.40％ (Bragg), 75.20％ (kwangkyo) for untreated flours to 9.75％ (Bragg), 26.27％ (kwangkyo) for 30 min steaming. But Kwangkyo variety showed twice higher protein extractability than Bragg variety.

• 한국통신학회논문지
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• 제30권3A호
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• pp.168-177
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• 2005

장거리 3×40 Gbps 파장 분할 다중 시스템에서 색 분산과 자기 위상 변조에 의해 왜곡된 광 펄스를 최상으로 보상할 수 있는 최적의 펌프 광 전력을 수치적 방법으로 살펴보았다. 광 펄스 왜곡 보상 기법으로 경로 평균 강도 근사를 채택한 MSSI (Mid-Span Spectral Inversion) 기법을 사용하였고, 전체 전송로 중간에서 MSSI를 수행하는 광 위상 공액기(OPC)의 비선형 매질로는 HNL-DSF(Highly-Nonlinear Dispersion Shifted Fiber)를 이용하였다. 광 대역 WDM 전송을 위한 OPC의 비선형 매질로는 HNL-DSF가 매우 유용하다는 것을 확인하였고, 최상의 보상을 위한 OPC의 펌프 광 전력은 OPC를 통해 두 번째 광섬유로 입사하는 공액파 광 전력이 WDM 채널의 입력 광 전력과 같아지도록 전체 전송 거리와 관련하여 선택되어야 한다는 것을 확인하였다. 또한 적은 변환 효율을 갖는 WDM 채널의 개선된 보상은 전력 변환비를 1 이상으로 증가시킬 수 있는 전력의 펌프 광을 이용해야 얻을 수 있다는 것을 확인하였다.

• 한국의류산업학회지
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• 제11권6호
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• pp.953-960
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• 2009

The natural dyeing of fabrics with myrobalan extract was investigated. After dyeing of silk, cotton and rayon with myrobalan extract, the dyeability of myrobalan extract was evaluated with the conditions of concentration, temperature, time, repeat-numbers, pH, mordants variables, the changes of dyeability and surface colors by methods of mordanting and color fastness. The wavelength of maximum absorption of the colored solution from myrobalan extract appeared at 272 nm. Therefore, the substance of myrobalan extract was verified as tannin dyes. The optimum dyeing of fabrics was carried out at 30%(o.w.f) dye concentration. Silk fabrics dyed with myrobalan extract showed the highest K/S value at the temperature of $80^{\circ}C$ when it was dyed for seventy minutes, while cotton and rayon fabrics showed the highest K/S value at the temperature of $90^{\circ}C$ when they were dyed for seventy minutes and thirty minutes, respectively. Dyeing operation was carried out in acidic dyebath of pH 3. The K/S value of silk fabric was higher in pre-mordant stage than in post-mordant, while the K/S values of cotton and rayon fabrics were higher in post-mordant stage. The surface colors of dyed fabrics were different according to used mordants: Al and Cu mordanted fabrics were dyed in yellowish colors, while Fe mordanted fabric was dyed in khaki-black color. Light-fastness of the color fastness was improved in Fe-mordant. Washing-fastness was relatively good, and dry cleaning-fastness of dyed fabrics was excellent.

• 분석과학
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• 제13권3호
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• pp.304-308
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• 2000

모의사용후핵연료로부터 sodium bisulfite 수층에 회수된 요오드($I^-$)를 이온크로마토그래피법을 이용해 정량할 때, 0.1 M sodium bisulfite와 1 mM 질산의 영향 없이 미량 오오드(1ppm)를 정량하기 위한 방법을 검토하였다. AS4A-SC(DIONEX) 컬럼과 자외선검출기를 사용하였고 sodium bisulfite, 질산 및 요오드의 자외선 흡광도를 측정하여 요오드 정량에 적합한 흡수파장으로 230nm를 선택하였고 용리액 농도는 0.1 M NaCl이 효율적이었다. 이 조건에서 0-1,000ppb 범위의 검정곡선을 작성하였다. 이때 선형상환계수는 0.99993 이었으며 검출한계는 5 ppb였다. 상대표준편차는 1.26% 이었다.

• 약학회지
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• 제52권1호
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• pp.7-11
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• 2008

A high performance liquid chromatographic (HPLC) method for the determination of glycyrrhizic acid was developed for the quality control of traditional herbal medicinal preparation Bu-Zhong-Yi-Qi-Tang (BZYQT), which is well-known herbal medicine used as tonic. RP-HPLC analysis was carried out using Capcell pak $C_{18}$ MG column $(5\;{\mu},\;150{\times}4.6\;mm)$ and a mobile phase consisting of acetonitrile and water containing 0.03% phosphoric acid (pH 2.46) at a flow rate of 1.0 ml/min. The optimum wavelength for the detection of the glycyrrhizic acid was found at 250 nm using diode-array UV/VIS detector. The glycyrrhizic acid in BZYQT shows good linearity $(r^2>0.999)$ in the range of $15\;{\mu}g/ml$ to 500 ${\mu}g/ml$. The limit of detection (LOD) was less than 5 ng and R.S.D for intra-day and inter-day reproducibility was less than 7%. The mean recovery of the glycyrrhizic acid was $97.3{\sim}113.0%$. These results suggest that the developed HPLC method is simple and efficient, and could be contributed for the quality control of commercial BZYQT products.