• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.396-399
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• 2000

기존이 역률보상회로가 별도의 전력변화단을 가지고 있어 소자수가 많아지고 복잡한 하드웨어 구성을 가지고 있는 단점이 있다 본 논문에서는 별 도의 전력변환단을 가지지않고 PFC기능을 가지는 단일 전력단(Single-Stage) 단상 AC/DC Forward Converter에 대하여 실험하여 검증하였다

• Magazine of korean Tunnelling and Underground Space Association
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• v.20 no.4
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• pp.74-86
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• 2018

• Geotechnical Engineering
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• v.35 no.5
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• pp.8-24
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• 2019

• Construction Engineering and Management
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• v.21 no.4
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• pp.25-30
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• 2020

• LP가스
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• s.68
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• pp.21-30
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• 2000

LPG산업구조개편단이 지난 3월 15일부터 22일까지 영국과 일본을 방문했다. 출장단의 일원이었던 협회 권순영 상무의 보고서를 게재한다.

• Journal of the Korean earth science society
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• v.41 no.3
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• pp.307-319
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• 2020

The purpose of this study was to determine whether there are differences in the verbal interactions of earth science gifted depending on their communications structures and group status in small group activities. To this end, a small group activity was conducted to measure the density of the earth, and 8 small groups were selected, including 4 co-ownership type and 4 monopolistics type groups with different communication structures. And then, the framework was developed for analyzing verbal interactions to compare the differences in characteristics between small groups. The results are as follows. First, regardless of the communication structures, there were showing a simple pingpong-type communication structures for all small groups. Second, negative interactions such as 'restraint', 'command', 'complaint', and 'lack of confidence' predominantly appeared in all small groups. Third, the students in the status of out-lookers in small groups were mainly verbal interactions, such as instructing the other person, acting against the other person's actions, and expressing dissatisfaction with the attitudes and abilities of members. Therefore, teachers should guide students to use higher-level verbal interactions in their group activities in small group activities, and engage in students communication to prevent negative interactions from occurring. The teachers also need to check the level of achievement for students in the status of out-lookers in advance and guide them to participate more actively in small group activities. This study is meaningful in that it can be sued to design teaching and learning to improve students' problem solving and communication skills.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.297-304
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• 2013

Purpose: To investigate blue light rejection and the percentage of blue light in the visible light of blue light blocking lens according to light source, and to study prescriptions for blue light blocking lens Methods: UV-VIS spectrophotometer was used for blue light rejection and the percentage of blue light in the visible light according to light source, and the percentage of blue light in solar light was used to evaluate the prescription for blue light blocking lens. Results: The blue light rejection and the percentage of blue light in the visible light of each lens were depending on light sources. Through the way to compare the percentages of blue light in the visible light passing through the lens with that in solar light, blue light blocking lenses suitable to each light source could been selected. Conclusions: In the prescription for blue light blocking lens, inquiry for user's display must be preceded. And then the percentages of blue light in the visible light passing through the lens based on that in solar light may be useful as a method of evaluating the prescription for blue light blocking lens.

• Korean Journal of Veterinary Service
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• v.42 no.1
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• pp.25-30
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• 2019

The objective of this study was to assess the possibility of detecting Foot-and-Mouth Disease Virus (FMDV) from the herd-based oral fluids specimens collected by the cotton ropes from pig farms that were found as FMDV nonstructural protein (NSP) antibodies positive. The cotton ropes were applied to detect FMDV in the selected pig farms which NSP antibodies were continuously detected in 2016, including the one pig farm which FMDV antigen were detected at the specimens from the pigsty environment. As the result, FMDV antigen were not detected in the oral fluid specimens collected by the cotton ropes. Theoretically, to detect FMDV antigen from the pigs with NSP antibodies has very low possibility because FMDV antigen disappeared at the time when NSP antibodies were produced by FMDV. Therefore, in order to detect FMDV antigen from the oral fluids using the cotton rope, it would be more effective to be applied to target the FMDV infected pigs rather than the NSP antibodies positive pigs. The collected oral fluids using cotton rope could be useful test specimens to monitor high-density pig populations for FMDV infection. Then, oral fluids sampling using cotton rope will be used for the efficient FMDV surveillance to detect FMDV antigen.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.12
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• pp.59-65
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• 1998

In this paper, a novel rail-to-rail input stage circuit with improved transconductance Is designed. Its excellent performances over whole common-mode input voltage Vcm range is demonstrated by circuit simulator HSPICE. The novel input stage circuit comprises additional 4 input transistors and 4 current sources/sinks. It maintains DC currents of signal amplifying transistors when one of the differential input stage circuits operates, but it reduces these currents to 1/4 when both differential input stage circuits operates, As a result, a operational amplifier with the novel circuit maintains nearly constant transconductance performance and unity-gain frequency in strong inversion region. The novel circuit allows an optimal frequency compensation and uniform operational amplifier performance over whole Vcm range.

• Communications of Mathematical Education
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• v.15
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• pp.119-126
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• 2003

학교 현장에서 아이들을 지도하다 보면 문제해결력이 상당히 낮다는 것을 자주 경험하곤 한다. 따라서 그러한 문제점에 대하여 고민하고 다양한 방법을 생각해 보는데, 그 해결 방안으로 소집단 협력학습을 실시하여 아이들의 전반적인 문제해결능력을 높여 보고자 본 연구를 실시하게 되었다. 그러기 위하여 소집단의 구성을 수학 성적을 토대로 하여 5단계로 분류하여 실시하였다. 이에 따른 연구 문제로는 크게 3가지로 정하였는데 다음과 같다. 첫째, 소집단 협력학습이 일제 학습에 비하여 수학 문제해결 능력을 향상시켰는가? (실험반과 비교함) 둘째, 소집단 협력학습이 개인별 수학 문제해결능력을 향상시켰는가? (개인별 비교; 실험반에 국한됨) 셋째, 소집단 협력학습이 수학 교과에 대한 아동들의 수학적인 태도변화를 가져왔는가? 위에서 제시한 연구 문제들을 해결한 결과, 실험반이 비교반보다 문제해결력이 유의미한 수준으로 높게나왔고, 또한 5단계로 분류한 아동들 개개인의 문제해결력에서는 특히 중하위권에 있는 아동들이 실험 후에 문제해결력이 높게 나왔다. 끝으로, 아동들의 수학적인 태도 변화에 관한 설문에서는 소집단 협력학습으로 인하여 수학에 대한 흥미와 자신감이 많이 생긴 것으로 나왔다. 따라서 7차 교육과정에서 주장하는 단계형 수준별 교육과정을 실행하는데 있어서 소집단 협력학습이 하나의 대안이 될 수 있을거라 생각하고, 아동들의 문제해결력을 높이는 또 하나의 수업 형태로서도 시도해 볼만한 것이라 생각한다.