• Journal of Power Electronics
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• 제16권4호
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• pp.1277-1287
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• 2016

This study proposes a novel isolated high step-up galvanic converter, which is suitable for renewable energy applications and integrates a boost converter, a coupled inductor, a charge pump capacitor cell, and an LC snubber. The proposed converter comprises an input inductor and thus features a continuous input current, which extends the life of the renewable energy chip. Furthermore, the proposed converter can achieve a high voltage gain without an extremely large duty cycle and turn ratio of the coupled inductor by using the charge pump capacitor cell. The leakage inductance energy can be recycled to the output capacitor of the boost converter via the LC snubber and then transferred to the output load. As a result, the voltage spike can be suppressed to a low voltage level. Finally, the basic operating principles and experimental results are provided to verify the effectiveness of the proposed converter.

• 전력전자학회논문지
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• 제23권4호
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• pp.281-285
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• 2018

An isolated feedback method for measuring the inverter DC-link voltage is proposed. This method provides a simple and economical solution to inverter control systems that use a flyback converter as a controller power supply. In the proposed method, data on the DC-link voltage are acquired when the primary side voltage appears on the secondary side of the flyback transformer, thereby eliminating the need to adopt an extra signal isolation method. To solve the non-synchronization problem between the flyback converter switching and main controller sampling, the external interrupt function of the micro-controller is used as a trigger signal for the A/D conversion.

• Mycobiology
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• 제42권2호
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• pp.158-166
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• 2014

In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant.

• 전기학회논문지P
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• 제54권4호
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• pp.171-178
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• 2005

The proposed dual-output DC-DC converter that bases on flyback converter can obtain two output voltage with non-isolated main-output and isolated sub-output at the same time using single-winding high frequency transformer. It can solve problems in multi-winding converter that use one main-switch, and also control quality of isolated sub-output voltage can be improved by additional sub-switch to the second. For analysis and design of the proposed converter system, converters are classified as operation mode from switching state and are become modeling by applying state space averaging method. Steady-state characteristics and dynamic characteristics are analyzed by DC component and perturbation component from state space averaging model. From experiment converter, validity of analysis and design for the propose converter system is confirm.

• 대한수의학회지
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• 제20권2호
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• pp.119-122
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• 1980

The udders of 28 culled dairy cows were removed at slaughter and bacteria isolated. Isolations of major known mammary pathogens comparised Staphylococcus sp. (40.7%), non-identified Gram's negative rods (33.2%) and E. coli (7.4%). In the mixed infection, Staphylococcus sp. was most frequently involved. Drug sensitivity tests were performed on several bacterial species by disc method. These tests indicated that the microorganisms isolated from clinical mastitis of dairy cows were more resistant to antimicrobial agents than the organisrms isolated from milk samples.

• 대한치과기공학회지
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• 제35권4호
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• pp.321-332
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• 2013

Purpose: This study was examined the characteristics of bacteria isolated from the dental stone that is made ??in the dental laboratory. Methods: 104 dental stones samples were collected from the 4 dental laboratory. Characteristics of bacteria were investigated by microorganism isolation culture method using a Blood Tryptic Soy Agar(TSA) medium. Results: The detected various bacteria was confirmed as pathogenic bacteria, non-pathogenic bacteria and natural bacteria. The isolated bacterial number was confirmed $2.9{\times}10^3CFU$ and maxium bacterial number of $3.0{\times}10^4CFU$. Conclusion: Therefore, infection prevention education is required, it must be to live up the hand-washing and wear protective clothing to protect themselves when working in a dental laboratory.

• 한국동물위생학회지
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• 제16권1호
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• pp.51-56
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• 1993

Feces were collected from pigs of various ages on slaughter house and swinery in the southern area of the kangwon-do. Treponema hyodysenteriae were isolated from the feces by the method of Jenkinson. and the effects of temperature on the survival of these organism were investigated. The results abtained are summerized as follows ; 1. T. hyodysenteriae were isolated from 22 fecal samples of 1, 296 samples, and showed higher incidence at 4-8week age groups than other age groups. 2. The organisms were isolated from 17 samples of 329 diarrhea samples and 5 samples of 967 non-diarrhea samples. 3. T hyodysenteriae survived long at $0-10^{\circ}C$ but survived short at $37^{\circ}C$ or above.

• 대한임상검사과학회지
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• 제41권2호
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• pp.52-56
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• 2009

Arcanobacterium haemolyticum was usually isolated from respiratory infection. Occasionally, the cases were reported to cause pharyngotonsillitis, cellutitis, and abscess. A. haemolyticum is V form gram-positive bacilli (coryneform bacilli), which isoften considered to be non-pathogenic normal flora or contaminants in respiratory, skin and wound infection. In order to discriminate from normal flora, incubation for at least 48 hours is recommended. We describe a case that A. haemolyticum was isolated from cellulitis with group G ${\beta}$-hemolytic Streptococcus, Klebsiella pneumoniae ssp. pneumoniae, and Prevotella disiens.

• 한국산업융합학회 논문집
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• 제4권2호
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• pp.167-175
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• 2001

In this study, a general perturbation method is presented to reanalysis dynamic response of base-isolated systems. The perturbation is expanded to general order and which provide the formulation of perturbed solutions. in which eigensolutions of non-modified system are treated as unperturbed solutions. The accuracy of present method is tested using a 2-DOF system with isolator, where the stiffness and damping coefficients of isolator are changed, respectively, The reanalyzed eigensolutions and response using perturbed solutions are successfully approached to exact ones after just first perturbation. Supposing the practical criterion as ${\pm}5%$ error, the modification range of -50%~30% from original system can be allowed for the first order perturbation. Using higher order solutions, the applicable range will be wide.

• Earthquakes and Structures
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• 제3권3_4호
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• pp.315-340
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• 2012

There are many types of seismic isolation devices that are being used today for structural control of earthquake response in buildings. The most commonly used are sliding bearings and elastomeric bearings, the latter with or without lead core. An alternative solution is the use of steel springs combined with viscoelastic fluid dampers, which is the case discussed in this paper. An analytical study of a three-story building supported on helical steel springs and viscoelastic fluid dampers, GERB Control System (GCS), subjected to near-fault earthquakes is presented. Several earthquakes records have been obtained by the acceleration network installed in the isolated building and in its non-isolated twin since they were finished. These experimental results are analysed and discussed. The aim is to show that the spring-based system can be an alternative for base isolation of small building located near active faults.