• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2013년도 춘계학술대회
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• pp.417-419
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• 2013

항만 VTS와 연안 VTS는 소속, 관제 구역, 주로 제공되는 서비스의 내용 등의 차이를 가지고 있다. 하지만 연안 VTS는 남해를 시작으로 전국으로 확장할 계획을 가지고 구축중이다. 그 결과 인접 VTS인 항만 VTS와 뗄 수 없는 사이가 되어버렸다. 여수는 항만 VTS와 연안 VTS가 동시에 시행되는 지역으로, 내년에는 인접 VTS인 통영 연안 VTS가 개국 될 예정이다. 반년 이상 운영되면서, 현재 가지고 있는 문제점에 대해 같이 생각해보고, 양 VTS간의 연계 필요성 및 방안에 관해 생각해보는 시간이 되었으면 한다.

• 전기학회논문지P
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• 제57권4호
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• pp.412-416
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• 2008

We have developed the calibration technique of the VT comparator using nonreactive standard resistors, which evaluates both accuracy and linearity of the VT comparator by comparing experimental values with theoretical values. The correction values of VT comparator obtained by using both our method and wide ratio error VT are consistent within the expanded uncertainty. Furthermore the specification for ratio error of VT comparator have been revaluated.

• 한국초등과학교육학회지:초등과학교육
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• 제39권1호
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• pp.54-68
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• 2020

The purpose of this study is to investigate how elementary teachers perceive and practice using Visual Thinking (VT) in science classes. For this, we collected 161 VT teaching materials for science that uploaded on the elementary teacher's online communities, and analyzed the characteristics. Also we interviewed four elementary teachers who have used VT in science class. The results are as follows. First, VT teaching materials shared in teacher's online communities were most often used to review the science concepts that students learned. Most of the materials required 'remember' among the Cognitive Process, and most of them provided layouts for VT activities. Second, the participants were using VT materials to review the science concepts they learned, so that students remember them. Third, the participants were satisfied because of the beliefs of effects as follows: facilitating learning and reviewing what students had learned; increasing students' positive reactions and confidence; learning through the interation among learners; the formation of habits thinking visually; indirect experiences of science class; possibility of class corresponding to learner characteristics. Fourth, the participants had difficulties in preparing for the VT science class, such as the burden of making VT materials, the long preparation time, concerns over overlapping contents, consideration of learners' VT skills, and the themselves' drawing ability. Furthermore, they also had difficulties in proceeding for the class, like different preference among learners about Visualization and loss of objectives in science class using VT. Fifth, the participants needed support as follows: platform to share students' VT results; VT case books and teachers' guidebooks; physical environment.

• 전기학회논문지
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• 제56권7호
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• pp.1268-1274
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• 2007

A recently developed methods for the on-site calibration of the voltage transformer (VT) comparator system have been reviewed in the paper. The method utilizes the several traveling standards consisting of the VT, the non-reactive standard resistors, the wide ratio error VT, and the decade resistors. The VT is used for the absolute evaluation of a standard VT belonging to the industry. The non-reactive standard resistor and wide ratio error VT are used for the linearity check of errors in the voltage comparator of the industry. The decade resistors are used for evaluation of a VT burden of the industry.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2010년도 추계학술대회
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• pp.209-211
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• 2010

본 연구는 싱가폴 VTS의 현장을 직접 방문하여 파악한 시설현황과 제도를 위주로 기술하였다. 관제사의 선발 시스템 및 교육 훈련 제도가 어떻게 운용되고 있는지에 대해서도 알아보았다. 또한 현재 싱가폴 VTS에서 추구하고 있는 차세대 VTS에 대한 방향에 초점을 맞추어 우리가 벤치마킹할 요소들에 대해서 집중적으로 검토해보고 우리나라 VTS의 발전방향을 모색하여 보았다.

• 전기학회논문지P
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• 제57권2호
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• pp.164-169
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• 2008

National standard system for calibrating voltage transformer(VT) up to primary voltage of 240 kV have been established in 2005. The system consists of voltage source, regulating unit, VT testing unit, standard VT, VT under test and VT burden. To verify and validate the performance for 240 kV VT calibration system, the comparison with the National Measurement Institute of Australia(NMIA) has been performed using same VTs. The comparison results of the VTs mesured at the Korea Research Institute of Stansdards and Science(KRISS) are consistent with those measured at NMIA within 0.002 % for ratio error and 0.14 min for phase displacement in the primary voltage ranges of Vp = 3300 V - 22000 V with a secondary voltage of Vs = 110 V.

• 한국미생물·생명공학회지
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• 제50권3호
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• pp.387-394
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• 2022

Verotoxin-1 (VT-1) or Shiga-like toxin 1 (Stx-1) is produced by enterohemorrhagic Escherichia coli (EHEC) and is an AB5 holotoxin with a strong inhibitor of protein synthesis. VT-1 is a type 2 ribosome-inactivating protein (RIP) that has been shown to have cytotoxic and anticancer potential by inducing necrosis, apoptosis, and cell cycle arrest, making it a promising antitumor candidate. Here, we tested the cytotoxicity of VT-1 on CaCo2 and NCM425 cell lines and the results showed that VT-1 was more potent on CaCo2. Morphological changes were also evaluated on the cellular level and the results showed that VT-1 caused a decrease in viable cell count, altered cell membrane permeability, and an increase in total nuclear intensity. On the other hand, VT-1 displayed a lesser impact on mitochondrial membrane potential (MMP) and cytochrome c release. On the expression of caspases 3 and 9, VT-1 exhibited an insignificant effect on both which alongside the mitochondrial membrane potential (MMP) and cytochrome c results, might indicate that CaCo2 suffered from the necrosis process as a mechanism of cell death after exposure to VT-1.

• 동아시아식생활학회지
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• 제16권2호
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• pp.145-155
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• 2006

This study investigated the correlation of the nutritional status of antioxidant vitamins and serum lipids and MDA levels in postmenopausal women. Data about general characteristics, dietary intakes and biochemical parameters, including serum lipids, MDA and antioxidant vitamins levels, were collected from 85 postmenopausal women. The subjects were classified into three groups according to their serum total cholesterol level: normocholesterolemia group (NC, < 200 mg/dL), moderate hypercholesterolemia group (MC, $200{\sim}239mg/dL$) and hypercholesterolemia group(HC, ${\geq}240mg/dL$). The results are as follows. 1) General characteristics and serum MDA levels were not significantly different among the three groups. 2) Daily nutrients intakes adjusted to energy intake were not significantly different among the three groups, and were compatible with dietary reference intakes (DRIs) for Koreans. 3) Dietary Vt. A, ${\beta}-carotene$, Vt. C and Vt. E intake were not significantly different among the groups, while Vt. E intake was positively related with serum TC (r=0.288, p<0.05) and triglyceride (r=0.341, p<0.001) levels. 4) Serum Vt. A level standardized by serum TC level was significantly low and serum Vt. E level was significantly high in the HC group. Serum Vt. E level was positively related with serum TC level (r=0.389, p<0.001). 5) Dietary Vt. E intake was negatively correlated to serum MDA level (r=-0.242 p<0.05). Serum Vt. C and Vt. E levels were also negatively correlated to serum MDA level (r=-0.312, p<0.001 and r=-0.299, p<0.05). When the correlation was analyzed only in the group with hypercholesterolemia, correlation coefficients between the antioxidant vitamin and serum MDA level were higher. We concluded that intakes of antioxidant vitamins can contribute to decreasing the risk of cardiovascular disease by decreasing the oxidative stress of body rather than by controlling serum lipid levels.

• 한국식품위생안전성학회지
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• 제15권3호
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• pp.241-247
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• 2000

국내 유통식품에서 verotoxin(VT)을 생성하는 대장균의 오염도를 조사하고 이로 인한 식중독의 발생을 사전에 예방하기 위하여 1997년부터 1999년 사이 햄버거. 식육 및 채소류에서 VT생성 대장균의 분포조사를 실시하였으며, 이 결과 분리된 대장균에 대한 분자생물학적 특성을 조사하였다 식육, 햄버거 및 채소류 총 1,700건의 식품 중에서 VT를 생성하는 대장균이 검출된 것은 3건으로 매우 낮은 검출율을 보였는데, 분리주의 혈청형은 각각 026 : H4, 0157 : H7 및 055 : Hl2였다. 혈청형 026 : H4 분리주는 VT I과 VT II를 생성하였고,055 : Hl2주는 VT I을 각각 생성하였으며, 두 분리주에서 eae유전자와 60 MDa plasmid DNA는 검출되지 않았다. 혈청형 0157 : H7주는 VT II를 생성하였고 60 MDa plasmid DNA는 검출되었으나 eae유전자는 확인되지 않았다. 따라서 분리된 VT생성 대장균들은 eae 유전자가 검출되지 않아 질병유발 가능성은 낮은 것으로 추정되었다. 항생제 내성능에서 혈청형 0157 : H7 분리주는 ampicillin과 streptomycin에 내성을 나타낸 반면, 혈청형 026 : H4주와 혈청형 055 : Hl2주는 ampicillin, carbenicillin, cephalothin, trimethoprim/sulfamethoxazole과 tetracycline에 내성을 보여 분리주의 다재내성능을 확인하였다 세포배양액으로 실시한 vero cell과 HeLa cell에 대한 세포독성능은 3주의 분리주에서 확인되었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권6호
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• pp.274-278
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• 2005

Voltage transformer(VT) comparison measurement system is usually used for measurements of ratio error and phase angle error of VT made in industry. Both ratio error and phase angle error in VT are critically influenced by values of burden of VT used. External burden effects on both ratio error and phase angle error in VT are theoretically calculated. From the theoretical calculation, a method of evaluation for linearity of ratio error and phase angle error in VT measurement system have been developed using the standard capacitive burdens, with negligible dissipation factor less than 10$^{-4}$. These burden consists of five standard capacitors, with nominal capacitance of 1.1 $\mu$F, 1 $\mu$F, 0.1 $\mu$F, 0.01 $\mu$F, 0.001 $\mu$F. The developed method has been applied in VT measurement system of industry, showing in good consistency and linearity within 0.001 $\%$ between theoretical and measured values.