• Journal of the Korean Applied Science and Technology
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• v.26 no.1
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• pp.24-28
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• 2009

본 논문에서는 청색 인광 발광 물질인 bis(3,5-Difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium (III) (Flrpic)과 녹색 인광 발광 물질인 fac-tris(2-phenypyridine) irdium(III) ($Ir(ppy)_3$)와 적색 인광 발광 물질인 his(5-benzoyl-2-phenylpyridinato-C,N)iridium(III) (acetylacetonate) ($(Bzppy)_{2}Ir(acac)$)를 각각 적층하여 백색 유기 발광 다이오드를 제작하였고, 각각의 발광층 사이에 혼합된 스페이서인 4,4'-N,N'-dicarbazole-biphenyl (CBP):4,7-diphenyl-1,10-phenanthroline (BPhen)을 적층하여 그 때의 영향에 대하여 연구하였다. 최적화된 구조에서의 전력 효율은 $0.014\;mA/cm^2$에서의 19.7 lm/w를 나타내었으며, $0.127\;mA/cm^2$에서의 11.5%의 외부 양자 효율을 나타내었고, 8 V에서 Commission Internationale do I'Eclairage ($CIE_{x,y}$) coordinates (x=0.36, y=0.44)의 색좌표를 나타내었다.

• Journal of the Korean Ceramic Society
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• v.34 no.3
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• pp.314-322
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• 1997

The thin film processing and the applicability as a IMD material of SiO2 aerogels providing ultralow dielec-tric properties were studied. The SiO2 aerogel films with 0.5g/㎤ density (78% porosity) and 4000~21000$\AA$ thickness could be prepared at 25$0^{\circ}C$ and 1160 psig by supercritical drying of wet-gel films, which were spin-coated at the spin rate of 1000~7000 rpm on p-Si(111) wafer under the isopropanol atmosphere. The optimum viscosity of polymeric SiO2 sols for spin coating was in the range of 10~14 cP. The main fac-tors being able to control the film thickness and microstructures were found to be sol concentration, spin rpm, and aging time of wet-gel films. The dielectric constant of the SiO2 aerogel thin film was around 2.0 low enough to be applied to the next generation semiconductor device beyond the giga level.

• Journal of the Korean Ceramic Society
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• v.34 no.3
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• pp.289-295
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• 1997

Effect of ceramic processing was investigated on the microstructure and electronic properties of low loss Mn-Zn ferrite. Addition of CaO and SiO2 to calcined powder rather than to raw materials mixtured resulted in finer-grained microstructure. Higher oxygen pressure during sintering caused microstructural inhomogeneity and the increase in power loss and disaccommodation factor. Relatively low power loss was found for sintering up to 130$0^{\circ}C$ from powders calcined at high temperature and milled shortly. It was caused by slow densification rate and normal grain growth up to 130$0^{\circ}C$. Calcination at low temperature and prolonged milling enhanced den-sification, which gave a fine grained microstructure and low powder loss at sintering temperture below 120$0^{\circ}C$. Sintering temperature above 125$0^{\circ}C$, however, showed abnormal grain growth.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.2
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• pp.93-104
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• 2013

The purpose of this study was to develop a list of plants that adapted to the aquatic environment in urban areas based on the list of plants surveyed through literature review and field surveys, and to classify the types of vegetation according to the five categories of plant distributions set by the U.S. Fish and Wildlife Service (1988) in the aspect of the adaptability of plants to the aquatic environment. Results of the classification by category according to the adaptability to the aquatic environment for the plant species surveyed through literature review and field surveys showed that there are 45 species of OBL, 96 species of FACW, 66 species of FAC, and 94 species of FACU, totaling 650 species. In addition, a total of 50 species excluding exotic species, endangered species, and naturally introduced plants are proposed as appropriate plants for the urban aquatic environment that will be artificially constructed. The results of the study can be utilized as the basic information for maintaining diversity and stability of the ecosystem during the restoration of water ecology; they can serve as useful data for the development of an optimum vegetation model when planting in water spaces in the future and preparing proper planting plans for each space. In addition, it is believed that the information will be useful in wetland identification and evaluation by observing plant species that appear only in wetlands.

• The Journal of Internal Korean Medicine
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• v.41 no.5
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• pp.811-820
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• 2020

Objective: The aim of this study was to report the effectiveness of traditional Korean medicine treatment of a gait disturbance in a patient with idiopathic normal pressure hydrocephalus induced by secondary Parkinsonism. Methods: The patient was treated with Korean herbal medicine (Yukmijihwang-tang-gami), acupuncture, moxibustion, and rehabilitation exercise. The gait of the patient was evaluated by the 10 m Walk Test, Timed Up and Go (TUG) test, 360° turning test, Functional Ambulatory Category (FAC), and GAITRite. Results: After 20 days of traditional Korean medicine treatment, we observed improvement in the symptoms of the gait disturbance. Conclusion: Traditional Korean medicine treatment might be effective in the treatment of gait disturbance in patients with idiopathic normal pressure hydrocephalus induced by secondary Parkinsonism.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.908-914
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• 1996

A number of techniques have been studied for handling uncertainty in the development of expert systems. One of techniques adopted in many expert systems is the Dumpster-Shafer Evidence combination scheme. This has been the main focus among others due to is favorable features and computational complexity. In this paper, we develop and algorithm to deal with the exponential complexity inherent in Dempster-Shafer evidence combination. In the evidence combination process, we divide the frame of discernment into two groups, one for those common in both belief functions and the other for the rest. A property is found that in computing new belief function for the latter group, the result of evidence combination show linear change. The irrelevancy factor is derived and used to compute the change. The main idea of the method is to reduce the size of the frame of discernment and thus exponential complexity.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.4
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• pp.449-456
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• 2007

Dispersion coefficient preprocessing schemes have been examined to improve plume dispersion model performance in complex coastal areas. The performances of various schemes for constructing the sigma correction order were evaluated through estimations of statistical measures, such as bias, gross error, R, FB, NMSE, within FAC2, MG, VG, IOA, UAPC and MRE. This was undertaken for the results of dispersion modeling, which applied each scheme. Environmental factors such as sampling time, surface roughness, plume rising, plume height and terrain rolling were considered in this study. Gaussian plume dispersion model was used to calculate 1 hr $SO_2$ concentration 4 km downwind from a power plant in Boryeung coastal area. Here, measured data for January to December of 2002 were obtained so that modelling results could be compared. To compare the performances between various schemes, integrated scores of statistical measures were obtained by giving weights for each measure and then summing each score. This was done because each statistical measure has its own function and criteria; as a result, no measure can be taken as a sole index indicative of the performance level for each modeling scheme. The best preprocessing scheme was discerned using the step-wise method. The most significant factor influencing the magnitude of real dispersion coefficients appeared to be sampling time. A second significant factor appeared to be surface roughness, with the rolling terrain being the least significant for elevated sources in a gently rolling terrain. The best sequence of correcting the sigma from P-G scheme was found to be the combination of (1) sampling time, (2) surface roughness, (3) plume rising, (4) plume height, and (5) terrain rolling.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.115-118
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• 2000

The production of cultured coho salmon (Oncorhpchus kisutoh) in Korea has being increased year after year. Smolt being reared in freshwater suffer transferring into seawater and are farmed in cages for fattening. This handling processes including transportation, confinement into cages are unavoidable stress to fish in salmon farming and often end up to mass mortality, This study aimed to investigate the impact of handling process on the stress responses of coho salmon. The indicator of stress was measured by cortisol to be a first response, and for the second response test, glucose, triBlyceride, cholesterol, lactate and electrolyte of $K^+, Na^+, Cl^-$ in serum and the activities of alanine aminotrtnferase (ALT), aspartate aminotransferase(AST) and lactate dehydrogenase (LDH) were analyzed. As a result, the concentration of cortisol, glucose as well as LDH activity were significantly increased, whereas others showed no difference comparing with control group. It obviously demonstrated that handling process made fish stressful.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.119-123
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• 2000

To study the stress response of coho salmon (Oncorhpohus kisutch) during transportation, the stress responses of the fish confined in a container box filled with freshwater or $5{\%{\circ}}$ salt-water were monitored pre and post 10 hours transportation. Changes of cortisol as the first stress indicator, and glucose (GLC), lactate (LAC), triglyceride (TG), cholesterol (CHOL), sodium ($Na^+$), chloride ($Cl^-$), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) as the second stress indicators were compared between the fish in two hauling media. Results showed significantly lower levels of cortisol, GLC, LAC, TG, CHOL and AST in salt-water group than freshwater group, It was shown that using salt-water for transportation could lessen the stress level of the coho salmon.

• Journal of Information Display
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• v.3 no.1
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• pp.6-10
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• 2002

We have synthesized a new green Ir(III) complex fac-tris-(3-methyl-2-phenyl pyridine)iridium(III) $Ir(mpp)_3$ and fabricated phosphorescent polymer light-emitting device using it as a triplet emissive dopant in PVK. $Ir(mpp)_3$ showed absorption centered at 388 nm corresponding to the $^1MLCT$ transition as .evidenced by its extinction coefficient of the order of $10^3{\cdot}$ From the PL and EL spectra of the $Ir(mpp)_3$ doped PVK film, the emission maximum was observed at 523 nm, due to the radiative decay from the $^3MLCT$ state to the ground state, confirming a complete energy transfer from PVK to $Ir(mpp)_3$. The methyl substitution has probably caused a red shift in the absorption and emission spectrum compared to $Ir(mpp)_3$. The device consisting of a 2 % doped PVK furnished 4.5 % external quantum efficiency at 72 $cd/m^2$ (current density of 0.45 $mA/cm^2$ and drive voltage of 13.9 V) and a peak luminance of 25,000 $cd/m^2$ at 23.4 V (494 $mA/cm^2$). This work demonstrates the impact of the presence of a methyl substituent at the 3-position of the pyridyl ring of 2-phenylpyridine on the photophysical and electroluminescence properties.