• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2503-2508
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• 2014

This study is about the selection and noise test of electronic sensor which is preceded by electric Operating Cell(EOC) development using electronic sensor technology to solve the structural weakness of Mechanism Operated Cell(MOC) in VCB, and has a final target in product development minimizing contact malfunction of the chattering or rebounce states caused by existing MOC. In this test results, when opening and closing VCB, rising velocity of surge voltage in opening time was measured 4.2 times faster than closing time and noise decibel value was measured respectively 120dB and 110dB. When supplying 60kV power frequency overvoltage, we found that sensor output graph in VCB opening and closing times operated stably without distortion. When supplying 150kV $1.2{\times}50{\mu}s$ impulse frequency voltage, we found that voltage graph of output contact in sensor opening and closing sides maintained a normal condition without distortion, and when supplying 2500A current, we found that tested result of electric field noise operated stably without distortion.

• Journal of the Korean Institute of Gas
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• v.13 no.5
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• pp.1-6
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• 2009

This paper presents the fuel consumption effects of LPG vehicle depending on the atmospheric temperature, LP gas leakage of vaporizer, viscosity of engine oil and engine load conditions. The fuel consumption test results show that when the temperature of engine temperature rises, the fuel consumption efficiency increases in general. The fuel consumption efficiency for an atmosphere temperature of $24.2^{\circ}C$ is 13.6% high compared to that of $1^{\circ}C$. No leak vaporizer on fuel consumption efficiency is 5.3% high compared to that of the LP gas leak vaporizer. The fuel economy of new engine oils is just 1.1% high compared to that of used oils with a LPG vehicle mileage of 9,500km. This is not an influential factor compared with an atmospheric temperature and a LP gas leakage. The more important factors on the fuel consumption efficiency are driving conditions such as a rapid braking, abrupt start and fast acceleration. The test results indicate that the normal start is 32.3% high compared to that of an abrupt start and the fast acceleration is 10.8% high compared with that of an abrupt start. And the fuel consumption efficiency for a rapid braking is 18.3% higher than that of an abrupt start. These indicate that the driving condition is very important to reduce the fuel consumption rate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.255-256
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• 2006

In this paper, we investigated the. characteristics of fault current limiting according to fault angle in the integrated three-phase flux-lock type SFCL in fault types such as the single-line-to-ground fault, the double-line-to-ground fault and the three-line-to-ground fault. When the SFCL is operating under normal condition, the magnetic flux generated between primary and secondary coils of each single phase is canceled out perfectly, so that the impedance of the SFCL is also not generated and the power system can be operated normally without any loss, However, if a fault occurs even in any phase out of three phases, quench happened in SFCL elements and the current flowing secondary coil is restricted abruptly. Finally, the balance of magnetic flux in whole SFCL system is destroyed, and the fault currents in every phase could be limited at the same time irrespective of the fault types. As a result, the developed SFCL in this study were operated normally as expected and the purpose of the integration of 3 phase current limiting was also achieved successfully. However, the fault current limiting characteristics of the SFCL was dependant on the quench characteristics of HTSC elements in each phase, and it was expected that the improvement of the SFCL could be possible through the introduction of HTSC elements which have better critical characteristics.

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.135-140
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• 2002

An experiment was conducted to determine the effects of vitamin C supplementation on the performance and egg quality of layers. A total of 800 ISA Brown layers of 71 weeks old were assigned to one of the following diets containing 0, 3, 10, 50 or 100 ppm LG-vitamin C, 100ppm free ascorbic acid, 100 ppm Rovimix stay C-35 or 50 ppm LG-vitamin C supplemented with 100 ppm Zn methionine chelate. The feeding trial was conducted for flour weeks during the period of May to June when the average ambient temperature was $23.8^{\circ}C$ (5 :00 PM). Each treatment was replicated five times with 20 birds housed in 2 birds cage units. Vitamin C supplementation did not improve the overall performances (egg Production and egg Quality). Birds fed 100 ppm of LG vitamin C had the lowest egg Production while birds fed 100 ppm of Rovimix-35 had the lowest egg weight among birds fed different sources of vitamin C. Although supplementation of vitamin C over 50 ppm increased soft and broken egg Production, supplementation of 10 ppm LG vitamin C showed lowest soft and broken egg Production among all treatments. E99she11 thickness was highest in the treatment of 50 ppm LG vitamin C. In conclusion, supplementation of vitamin C at the level of 3 ~ 100 ppm did not significantly influence the laying performance and eggshell quality of laying hens under normal ambient(20 ~$26^{\circ}C$ ) condition.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.162-177
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• 2001

The hydrolysis rates of seven kinds of polyol ester base oils 〔POEs〕 of different branch shape were investigated by using a simple apparatus under mild acidic condition. Seven polyol ester base oils were made of poly hydric alcohols of two-four valence, normal or branched fatty acids of different carbon number. p-Toluene sulfonic acid was used as acid catalyst to accelerate the rate of hydrolysis. Partial esters and fatty acid produced by sequential hydrolysis of POEs were identified and their concentrations were determined by calibrated-internal standard method using Gas Chromatography. The rate constants of each step in sequential hydrolysis were determined by the least square method from rate equation and the concentration of each component, were compared with one another. It was shown that the rate of hydrolysis of POEs was strongly affected by whether molecular structure of fatty acid was straight chain or branch chain and which position was branched. The hydrolysis stability for all the POEs can be reasonably explained by using a steric hindrance effect anticipated fi:om their molecular structures affecting as water molecule makes an attack on the carbonyl carbon of POEs.

• Journal of Korean Society on Water Environment
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• v.34 no.4
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• pp.363-374
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• 2018

The Han River serves as an important water resource for the city of Seoul, Korea and in the neighboring metropolitan areas. From the Paldang dam to the Jamsil submerged weir, the 4 water intake stations that are located for the Seoul metropolitan population were under review in this study. Therefore the water quality management in this section is very important to monitor, analyze and review to rule out any safety concerns. In this study, a 3-D hydrodynamic model, EFDC (Environmental Fluid Dynamics Code), was applied to the downstream of the Paldang Dam in the Han River, which is about 23 km in length, to determine issues related to water resource management. The 3-D grid was composed of 2,168 horizontal grids and three vertical layers. In this case, the hydrodynamic model was calibrated and verified with an observed average daily water surface elevation, water temperature and flow rate data for 3 years (2013~2015). The developed EFDC model proved to reproduce the hydrodynamics of the Han River well. The composition ratios of the noted incoming flows at the monitored intake stations for 3 years and their flow patterns in the river were analyzed using the validated model. It was found that the flow of the Wangsuk Stream depended on the Paldnag dam discharge, and it was noted that the composition ratios of the stream at the intake stations changed accordingly. In a word, the Wangsuk Stream moved mainly along the right bank of the Han River under the condition of a normal dam flow. As can be seen, when the dam discharge rate was low, the incidence of lateral mixing was often seen. The scenario analyses were also conducted to predict the transport of conservative pollutants as in the case of a chemical spill accident. Generally speaking, when scenarios were applied, the arrival time and concentration of pollutants at each intake station was thus predicted.

• The Journal of Pediatrics of Korean Medicine
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• v.22 no.1
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• pp.69-93
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• 2008

Objectives The purpose of this study is to investigate the effect of KKHS on atopic dermatitis in an in-vivo experiment using an NC/Nga atopic dermatitis mouse, which has histological and clinical similarities to this condition in humans. Methods To investigate the effect of KKHS on atopic dermatitis (AD), we evaluated atopic dermatitis-like skin lesions by clinical skin index and analyzed immunological parameters in peripheral blood mononuclear cells(PBMCs), splenocytes, draining lymph node(DLN) and performed skin histology in ears and dorsal skin of atopic dermatitis of NC/Nga mouse in vivo. Results In vivo, clinical skin severity score was significantly lower in the KKHS group than in the control group. IgE, IL-6, TNF-${\alpha}$, IgM, IgG2a and IgG2b levels in serum decreased remarkably in the KKHS group than in the control group, and the level of IFN-${\gamma}$ production which is secreted from Th1 cell was increased by KKHS. After this experiment we analyzed immunological cells ($CD3^+$, $CD19^+$, $CD4^+$, $CD8^+$, $CD3^+CD69^+$, $CD4^+CD25^+$ and $CD49b^+$) by flow cytometry. It results that the total absolute number of $CD3^+$, $CD19^+$, $CD4^+$ and $CD8^+$ cells were recovered as much as normal state, and the level of $CD3^+CD69^+$ in isolated DLN and PBMCs were significantly decreased, and total absolute number of $Gr-1^+$, $CD11b^+$ and $CD3^+$ in dorsal skin of NC/Nga mouse were decreased by KKHS. We analyzed ear, DLN, and neck-back skin after biopsy and dyeing by hematoxyline/eosin(H&E), toluidine staining (mast cells marker). KKHS were very effective to the histological symptoms which are in dermal and epidermal thickening, hyperkeratosis and inflammatory cell infiltration. Ear thickness was significantly decreased compared with the control group and the size of inflammatory lymphocytes cells (ILC) and plasma cells (PC) in DLN were also decreased. Conclusions KKHS on atopic dermatitis in an in-vivo experiment using an NC/Nga atopic dermatitis mouse was very effectiveness to the atopy dermatitis treatment.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.19-23
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• 2002

This experiment was conducted to micropropagate bulblets via shoot cluster formation and massproduce normal bulblets from the sections of proliferated shoot clusters in Lilium asiatic hybrid 'Hae Hwa'. The induction of shoot clusters from the culture of bulblet sections was more effective than that of bulb scales on MS medium with 1.0 mg/L BA and 0.5 mg/L IAA. Proliferation of shoot clusters from the formed shoot cluster sections was the most favorable on medium containing 5.0 mg/L BA and 0.5 mg/L IAA. The formation and the growth of bulblets from shoot cluster sections were achieved effectively on medium with 60∼90 g/L sucrose. The leaves derived from shoot clusters grew vigorously but the bulblets from shoot clusters grew very poor in 5L air-lift bioreactor culture. By the addition of 30 mL fresh liquid medium containing doulble strength MS salts, 250 g/L sucrose and 5 g/L activated charcoal after 8 weeks in the shoot cluster culture on MS medium with 5.0 mg/L BA and 0.5 mg/L IAA, the number of bulblets was increased in light condition, but the growth of bulblets was not affected by light. Bulblet production was possible with the bulblet product at 53 to 68 mg in fresh weight by liquid medium addition after the proliferation of shoot cluster.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.4 no.2
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• pp.77-87
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• 1986

As for the deformation measurement of structure, there are many controversial points in using the methods by the strain guage, inclinometer, bial guage, and geodetic method because of the difficulty of instrument setting and the problem in the degree of accuracy of the results as well as in the economical aspect. Therefore, to verify the superiority of the Close- Range Photogrammetry method for the structural deformation measurement, the result of load deformation on the model structure, which was made using the Close-Range Photogrammetry method was compard with the results which was made using the methods of dial guage, precision level, and triangulation. In addition to that, to consider the general problem which would happen when C. R. P method was applied to the practical structure. The elements of C. R. P method like camera rotation angle ($\psi$,$\omega$), exposure elevation (Z$_{L}$), and angle of inclined base line ($\theta$) were experimented, and their specificities were reconsidered. As a result, the application of C. R. P method to the general structure is expected to be increased not only in the aspect of accuracy but in the economical aspect.t.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.574-581
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• 2001

The microbial properties and acid tolerance of the three kinds of Acetobacter sp. isolated from persimmon vinegar were investigated. Acid tolerance was also evaluated. Acetobacter sp. were gram negative, short rod, nonspore forming and motile. They reacted positively catalase, methyl red, oxidation fermentation, Voges-Proskauer and nitrate reduction tests and negative to hydrogen sulfide test and ONPG. Acetobacter sp. showed normal growth curve in Carr broth and there was no significant difference between isolates and (standard on) typical strains such as Acetobacter aceti (KCTC1010), Acetobacter liquefaciens (KCTC2804), Acetobacter diazotrophicus (KCTC 2859). Optimum temperature and initial ethanol concentration in incubation were $30^{\circ}C$ and 6%, respectively. Growth and acid production of Acetobacter sp. were suppressed by the concentration of above 4% acetic acid. The amount of $Mg^{++}$ release from Acetobacter sp. cells in medium was increased by acetic acid, and almost in the concentration of 6% acetic acid. Glycolysis by Acetobacter sp. had optimal pH about 6.0 to 7.0 and more stable in acidic condition than in alkalic. The $H^+-ATPase$ of Acetobacter sp. S-1 and S-3 showed a maximal activity between pH values of approximately 5.5 to 7.5 and 6.0 to 7.5, respectively.