• 한국환경보건학회지
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• 제31권1호
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• pp.23-30
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• 2005

Staphylococcus aureus is one of the important pathogenic agents, which are related to the hygienic condition. This study performed for the detection of Staphylococcus aureus and screening staphylococcal enterotoxin a, b, c genes in strains isolated from the environment for production of non-pasteurized strawberry juice. A total of 44 samples were collected from utensils, machinery, employees, raw materials, and strawberry juices in 3 strawberry juice shops in Jinju, western Gyeongnam. The isolation rate of Staphylococcus aureus was 26%. Specially Staphylococcus aureus was frequently isolated from employee's hands, strawberry and strawberry juices. The sea, seb, and sec genes were also investigated by polymerase chain reaction (PCR). One hundred and 55% of each isolate had found sea gene and seb gene, respectively. However, sec gene was not detected anywhere. To prevent food-borne disease associated with juice, the accomplishment of HACCP to be more efficient and systematic is necessary.

• Journal of Chest Surgery
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• 제25권2호
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• pp.131-136
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• 1992

The effect of temperature of cardioplegic solution on myocardial preservation was studied using isolated rat heart perfusion technique. Twenty Sprague-Dawley rats, weighing 120~140gm, were pretreated with intraperitoneal injection of heparin sodium[300u/kg] and then the hearts were excised after cervical herniation 30 minutes later. The hearts were perfused in isolated working heart apparatus with oxygenated modified Tyrode solution at 37oC. After 10 minutes of non working heart perfusion, the hearts were subjected to arrest for 30 minutes by administration of 5cc cardioplegic solution at the temperature of 4oC [Group I ], 15oC [Group II], 25oC [Group III], 37oC[Group IV]. At the same time, the topical cooling of heart was performed using ice saline. After arrest, the hearts were reperfused by non working heart perfusion for 1 hour with modified Tyrode solution at 37oC. The CPK, GOT and LDH in reperfusate were measured at 5,20,40,60 minutes after start of reperfusion. With the values of those, we compared the effect of temperature of cardioplegic solution on myocardial preservation. The results were as follows; 1. The enzyme values in reperfusate were highest at 5 minute and after then declined. 2. At 5 minutes after reperfusion, the enzyme values in Group I were lower than those in other Groups. These results suggest that the cardioplegic solutions using for cardiac arrest and myocardial protection can be working better at 4oC than at any other temperature.

• Structural Engineering and Mechanics
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• 제31권6호
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• pp.639-662
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• 2009

A comprehensive investigation of the stochastic response of an isolated cable-stayed bridge subjected to spatially varying earthquake ground motion is performed. In this study, the Jindo Bridge built in South Korea is chosen as a numerical example. The bridge deck is assumed to be continuous from one end to the other end. The vertical movement of the stiffening girder is restrained and freedom of rotational movement on the transverse axis is provided for all piers and abutments. The longitudinal restraint is provided at the mainland pier. The A-frame towers are fixed at the base. To implement the base isolation procedure, the double concave friction pendulum bearings are placed at each of the four support points of the deck. Thus, the deck of the cable-stayed bridge is isolated from the towers using the double concave friction pendulum bearings which are sliding devices that utilize two spherical concave surfaces. The spatially varying earthquake ground motion is characterized by the incoherence and wave-passage effects. Mean of maximum response values obtained from the spatially varying earthquake ground motion case are compared for the isolated and non-isolated bridge models. It is pointed out that the base isolation of the considered cable-stayed bridge model subjected to the spatially varying earthquake ground motion significantly underestimates the deck and the tower responses.

• 전력전자학회논문지
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• 제18권4호
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• pp.342-348
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• 2013

In this paper, an improved non-isolated 3-level high step-up boost converter is proposed. By using the well known duality principle, the proposed converter is derived from two-phase buck converter. Compared with the traditional boost converter and 3-level boost converter, the proposed converter can obtain very high voltage conversion ratio and the voltage stress of switching devices and diodes is only 1/4 of the output voltage. A 1 kW prototype converter is built and tested to verify performances of the proposed converter.

• 한국미생물·생명공학회지
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• 제18권5호
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• pp.501-505
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• 1990

토양으로부터 분리한 Streptomyces 속 세균 KIS 13은 thiol 계통 단백질분해효소 활성을 특이적으로 저해하는 저분저량 저해물질을 생성하였다. 저해물질 생성은 세균체성장에 연관된 생성양상이 나타내었다. 배양액으로부토 butanol 추출, silicagel 60 column chromatography, Sephadex LH-2 gel-filtration chromatography, preparative HPLC 등의 과정을 통하여 단백질 분해효소 저해물질을 순수분리하였다. 이 저해물질은 Hammersten casein을 기질로 사용할때, papain에 대하여 non-competitive한 저해양상을 나타내었다.

• Natural Product Sciences
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• 제1권1호
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• pp.5-9
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• 1995

The metabolites of marine mollusk Mytilus edulis were isolated and characterized, revealing the presence of the rare free fatty acids and proteinogenic amino acids together with a non-proteinogenic free amino acid, taurine. The free fatty acids in this organism were particularly interesting for the presence of both unusual n-6 acid [20:4 (n-6)] and triple bond containing acid (2,5-octadecadiynoic acid). In addition to the proteinogenic amino acids commonly found in proteins, non-proteinogenic free amino acid taurine was isolated and the structure was determined by its physicochemical properties. Recently taurine has been given much interest in the molecular level because of diverse biological activities and the medicinal properties. Furthermore, the result of the analyses of analyses of free amino acids showed that glycine, glutamic acid, serine and alanine, which were considered to be related to the taste of this organism, are predominantly present.

• 한국정보처리학회논문지
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• 제7권6호
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• pp.1964-1972
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• 2000

For the Korean language, on acoustics, it creates a different form of phonetic value not a phoneme by its own peculiar property. Therefore, the construction of extended recognition system for understanding Korean language should be created with a study of the Korean rule-based system, before it can be used as post-processing of the Korean recognition system. In this paper, text-based Korean rule-based system featuring Korean peculiar vocal sound changing rule is constructed. and based on the text-based phonetic value result of the system constructed, a preliminary phonetic value segmentation border points with non-uniform blocks are extracted in Korean isolated word speech. Through the way of merge and recognition of the non-uniform blocks between the extracted border points, recognition possibility of Korean voice as the form of the phonetic vale has been investigated.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.25-26
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• 2011

In some cases of grid connected system using photovoltaic modules, high voltage step up ratio is required. In this paper, non-isolated 2-stage cascaded boost converter with coupled inductor is proposed. Due to reduce the input current ripple and size of the inductor by using coupled inductor method, this topology is suitable for MIC(Module Integrated Converter). The operational characteristic of the proposed topology is verified through the theorical analysis, simulation and experimental waveform.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.493-496
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• 1999

A new soft switching single stage AC-DC full bridge boost converter with unit input power factor and isolated output is presented in this paper. Due to the use of a non-dissipative snubber on the primary side, a single stage high-power factor isolated full bridge boost converter has a significant reduction of switching losses in the main switching devices. The non-dissipative snubber adopted in this study consists of a snubber capacitor Cr, a snubber inductor Lr, a fast recovery snubber diode Dr, and a commutation diode Dr, and a commutation diode Dp. This paper presents the complete operating principles, theoretical analysis and experimental results.

• 전력전자학회논문지
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• 제17권2호
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• pp.142-149
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• 2012

The independently regulated dual-output LLC resonant converter using only one power stage and one control IC is proposed in this paper. The conventional dual-output LLC resonant converter requires the extra non-isolated DC/DC converter to obtain the tightly regulated slave output voltage, which results in the low power conversion efficiency and high production costs. On the other hand, since the proposed converter controls the master and slave output voltages by pulse width modulation(PWM) and pulse frequency modulation(PFM), it can achieve tightly regulated dual output voltages without the additional non-isolated DC/DC converter. Therefore, it features a high efficiency and low cost. To confirm the validity of the proposed converter, theoretical analysis and experimental results from a 40W LED driver prototype are presented.