• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1416-1418
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• 2005

A new DCM derivative containing a phenothiazine moiety, 4-(dicyanomethylene)-2-t-butyl-6-(9-ethylphenothiazine-2- enyl)-4H-pyran (DCPTZ), has been synthesized as an orange-red fluorescent dye molecule for organic lightemitting diodes (OLEDs). EL devices with the structure of $ITO/PEDOT-PSS/{\alpha}-NPD/Alq_3:DCPTZ/Alq_3/LiF/Al$ have been fabricated with changing the doping concentration of the DCPTZ. Maximum EL spectra of the devices ranged from $580{\sim}620$ nm depending on the doping concentration of the dye molecule. An EL device with 0.5 % doping concentration showed CIE coordinate (0.51, 0.47) at luminance of 100 $cd/m^2$. White light-emitting devices with the structure of $ITO/PEDOT-PSS/{\alpha}-NPD/{\alpha}-NPD:DCPTZ/DPVBi/Alq_3/$ LiF/Al have been also fabricated. The thickness of blue light-emitting 1,4-bis(2,2- diphenylvinyl)benzene (DPVBi) layer was changed to obtain a white light-emission. A white light-emission from the device was observed when the thickness of the DPVBi layer became thicker than 10 nm.

• Journal of the Korean Chemical Society
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• v.35 no.6
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• pp.659-666
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• 1991

A systematic analysis of 18 stimulants and narcotic analgesics containing nitrogen atom (s) in human urine by gas chromatography with nitrogen phosphorus detector (GC-NPD), is described. The urinary extract with diethyl ether at pH 8.5 showed good recoveries of the drugs and less interference peaks on GC chromatogram. Retention data were standardized by the calculation of relative retention times using diphenylamine as the internal standard. The relative standard deviations of retention times were less than 0.1% for the within-run analyses. The response factor (RRF) of a drug relative to the internal standard was calculated. RRF decreased with increasing number of nitrogen atoms. This technique can be adapted to various analytical toxicology problems.

• Journal of Technology Innovation
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• v.21 no.1
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• pp.165-198
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• 2013

The purpose of the study is to identify risk factors and analyze risk impacts to increase R&D outcome by taking into consideration the activities undertaken in each phase of New Product Development(NPD) process. The paper builds on survey research that has been developed new IT products within the past 5 years at SAMSUNG and LG subsidiaries in the Republic of Korea. This study identified risk factors in accordance with NPD process and evaluated the identified risk factors with survey questionnaires. To analyze the risk impacts were used to perform a logistic regression analysis based on R&D output. The impact of risk factors were higher for the low-output group. High-output group took a risk into consideration unique undertakings in project management and managed risk factors effectively in order to increase R&D output. Consequently, with the aim of improving output of R&D, a risk management is necessary to identify the risk factors for each phase of NPD and focus on managing risk factors with great effect.

• Journal of Life Science
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• v.11 no.5
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• pp.432-438
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• 2001

Various lactic acid bacteria were isolated from Korean Dongchimi (whole radish Kimichi with added water) in order to study their antimutagenic activity. Ames test using Salmonella enterica serovar typhimurium TA98 and TA100 showed the strain DLAB19 to have the highest antimutagenic activity among the 300 isolated strains against MNNG(N-methyl-N-nitro-N-nitrosoguanidine), NPD (4-nitro-O-phenylenediamine), 4-NQO(4-nitroquinoline-1-oxide) and AFB$_{1}$(aflatoxin B$_{1}$). The strain was identified as Leuconostoc mesenteroides subsp. cremoris according to the Bergeys Mannual Systematic Bscteriology based on its morphological, cultural, physiological characteristics and biological system Antimutagenic activity of Leu. mesenteroides subsp. cremoris DLAB19 was found in the culture supernatant suggesting the bacterium secretes, the antimutagenic substance in the media. The antimutagenic activity of Leu. mesenteroides subsp. cremoris DLAB19 was reconfirmed by the spore-rec assay using spores of Bacillus subtilis H17 (Rec$^{+}$) and M45 (Rec$^{[-10]}$ ).).

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.6
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• pp.81-93
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• 2019

As customers' needs are more diversified, the issue of managing product variety has become more important to manufacturers. It is because an increase in product variety may cause various inefficiencies in operations, while satisfying more diverse needs. Consequently, firms have introduced the concept of modularity to improve operational performance. Yet there are only a few studies which analytically investigate the effect of modularity in new product development (NPD). Therefore, this research develops an analytical model of exploring the effect of modularity on firm profitability when a component built upon new technology is introduced into an existing product, and provides important managerial implications on the NPD and technology management, which can guide the decision making on modularity in practice. The results show that it is necessary to increase modularity level when i) the product is easy to upgrade, ii) the product's price should be high due to external factors, and iii) the effect of new technology investment is uncertain, while it is desirable to increase the investment cost for introducing new products with low demand elasticity for modularity.

• Journal of Environmental Science International
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• v.15 no.8
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• pp.811-817
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• 2006

We were carried out to monitor pesticide residues in herbal medicine. In Korea Pharmacy, these are no critics for pesticides except 5 kinds of organic chlorines (BHC, DDT, Aldrin, Endrin, Dieldrin) and heavy metals. We analysed 53 kinds of pesticides consisted of 14 kinds of organochlorines, 20 kinds of organophosphoruses, and 19 kinds of pesticides estimated endocrine disruptor on 373 samples consisted with 30kinds of herbal medicine. In this study, Domestic, Chinese and Japanese herbal medicines were tested with GC/ECD, GC/NPD and then confirmed with GC/MSD. Recoveries were 75$\sim$l10% in ECD detector and 76$\sim$97% in NPD detector. Detection limits were 0.004$\sim$0.064ppm in ECD detector and 0.006$\sim$0.094ppm in NPD detector. Organochlorines and others were not detected in samples.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.8-10
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• 2010

We report the enhancement of hole injection using thermally evaporated $CuO_x$ layer between Ag anode and 4,4'-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl ($\alpha$-NPD) in top-emitting organic light-emitting diode (TEOLED). The operation voltage at the current density of $1mA/cm^2$ of TEOLEDs decreased from 6.2 V to 5.0 V as the $CuO_x$ layer inserted between Ag and $\alpha$-NPD. $\alpha$-NPD was deposited in situ on Ag/$CuO_x$ and Ag anodes, and their interface dipole energies were quantitatively determined using synchrotron radiation photoemission spectroscopy. The dipole energy of Ag/$CuO_x$ was lower by 0.05 eV even though Ag/$CuO_x$ had a higher work function. The work function of Ag/$CuO_x$ is higher by 0.53 eV than that of Ag, resulting in a decrease of the turn-on voltage via reduction of hole injection barrier.

• Analytical Science and Technology
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• v.21 no.2
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• pp.84-92
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• 2008

A method for the determination of trace amount of caffeine in urine and various drink samples using hollow fiber-liquid phase microextraction (HF-LPME) and capillary gas chromatograph/nitrogen phosphorus detector (GC/NPD) has been established. HF-LPME method has been optimized with respect to several experimental parameters including the effects of the hollow fiber length, extraction solvent, stirring mode, pH and salt concentration for the determination of caffeine from aqueous samples. The correlation coefficient of calibration curve for caffeine was 0.9994. The average recovery was 102%(n=3). The established method is feasible for the determination of trace amounts of caffeine in several aqueous sample. The limit of detection (LOD) and the limit of quantitation (LOQ) have been found to be 2.5 and 10 ng/mL, respectively. The established HF-LPME method for the analysis of caffeine from aqueous sample can be used for the determination of biological, food and environmental samples.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.1-7
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• 2006

In this paper, two types of blue organic light-emitting device were designed. We have analyzed the characteristics of Type I device without a hole blocking layer, and analyzed the characteristics of Type II device using a hole blocking layer of BCP or BAlq materials with 30 ${\AA}$ thickness. We obtained the ITO having the work function value of 5.02 eV using $N_2$ plasma treatment method with the plasma power 200 W. Type I device structure was ITO/2-TNATA/$\alpha$-NPD/DPVBi/$Alq_3$/LiF/Al:Li, and type II device structure was ITO/2-TNATA/$\alpha$-NPD/DPVBi/HBL/$Alq_3$/LiF/Al:Li. We have analyzed the characteristics of Type I and Type II device. The characteristics of the device were most efficiency on occasion of using a hole blocking layer of BAlq material with 30 ${\AA}$ thickness. Current density was 226.75 $mA/cm^2$, luminance was 10310 $cd/m^2$, Current efficiency was 4.55 cd/A, power efficiency was 1.43 lm/W at an applied voltage of 10V. The maximum EL wavelength of the fabricated blue organic light-emitting device was 456nm. The full-width at half-maximum (FWHM) for the EL spectra was 57nm. CIE color coordinates were x=0.1438 and y=0.1580, which was similar to NTSC deep-blue color with CIE color coordinates of x=0.14 and y=0.08.

• Food Science and Preservation
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• v.15 no.2
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• pp.293-299
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• 2008

Bacillus sp. SP-KSW3 is an auxothroph bacteria that is being used for starter in fermentation. Physico-chemical characteristics, enzyme activities, ACE inhibitor and antimutagenicity in fermented soybean (Kanjang) inoculated with Bacillus sp. SP-KSW3 starter was investigated for the ripening duration of fermentation. Tyrosinase and ACE showed 7% higher activity degree on the Kanjang maturated fermented 2 years with Bacillus sp. SP-KSW3 (Type I) than test field than Kanjang maturated 2 years (control). For antimutagenicity using S. enterica serovar Typhimurium TA100 against MNNG and NPD showed 35.17% and 28.37% (Type I). Similarly, S. enterica serovar Typhimurium TA98 was used against NPD and NQO showed 25.48% and 21.64% (Type I), respectively. Hydrogen donating ability 2 year for maturing (Type I) appeared most highly in the test eulogy 83.1% which it makes. Daidzin of isoflavone in fermented soybean showed similarly. Genistein was not detected The initial test field for daidzin and genistein contained 3.95 mg/kg and 1.25 mg/kg (Type I), respectively.