• Journal of Elementary Mathematics Education in Korea
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• v.17 no.2
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• pp.371-394
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• 2013

The purpose of this study is to understand the public education system in Korea, that features many pre-taught students, and to figure out how elementary school teachers teach them. To accomplish this study, 204 elementary school teachers in Seoul participated in a survey and the frequency and percentage were made. In addition, to add more depth to this study 5 elementary school teachers had several interviews. We obtained the following results. First, elementary school teachers generally think that the situation with many pre-taught students have had a bad effect on public education and pre-taught students are drilled but cannot understand what they have learnt. They also answered that they have low morale when teaching pre-taught students. Second, a large number of elementary school teachers think the situation with many of the pre-taught students does not help the public math education system, which influences the teachers' teaching style. Teachers who answered negative on pre-taught students are running their math classes focusing on understanding math concepts and activities. On the other hand, few teachers who answered positive on pre-taught students did not care about the situation with many pre-taught students.

• Journal of Gifted/Talented Education
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• v.21 no.2
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• pp.531-546
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• 2011

In order to investigate the differentiation for gifted students, we studied the present condition of differentiation applied in science classes at regular schools, private educational institutes, and gifted education centers. A questionnaire regarding differential instruction was administered to 90 eighth graders enrolled in university- based gifted centers in Seoul. The results of chi-square testing based on the questions and educational institutions showed that students used only a textbook at regular schools and several workbooks at private educational institutes, while students could use various specialty publications at gifted education centers. Students frequently took post-test at regular schools and private education institutes. Further, at regular schools and private education institutes, students who completed curricular activities early spent their time performing unrelated tasks or reviewing the lessons or solving problems. Gifted students tend to develop their interests by themselves through science classes at regular schools. However, efforts to group students according to their interests were predominant at the gifted education centers. The response rate for students' choice of curricular activities and teachers' preparation for advanced learners were the lowest in all questions.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.65-70
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• 2016

Investigation on weed flora in Angelica gigas upland fields was conducted to understand the current status of the weed flora and establish the control measures. Investigation was conducted twice, July and October in 2015. From this investigation, 105 species of 37 families including 27 exotics were identified and classified into 53 species of annuals, 24 species of biennials and 28 species of perennials. Dominance was the highest with Digitaria ciliaris, followed by Portulaca loeracea, Chenopodium album, Cyperus iria, Conyza canadensis, Galinsoga ciliata etc. in order. Chenopodium album was the highest in importance analysis and the followings were in order of Conyza canadensis, Galinsoga ciliata, Amaranthus lividus, Taraxacum offcinale etc. The yield of A. gigas was reduced 49.6% in no weeding plots comparing in weed managed plots.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.60-64
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• 2016

Investigation on weed flora in Lycium chinense upland fields was conducted to understand the current status of weed flora and establish the control measures. Investigation was conducted twice, May and June on 2015. From this investigation, 91 species of 30 families including 27 exotics were identified into 36 species of annuals, 28 species of biennials and 27 species of perennials. Dominance was the highest with Portulaca loeracea followed by Digitaria ciliaris, Stellaria media, Oxalis corniculata, Acalypha australis, Chenopodium album, Cyperus iria etc. in order. Chenopodium album was the highest in importance analysis and the followings were in order of Conyza canadensis, Conyza bonariensis, Senecio vulgaris, Amaranthus lividus, Sonchus asper etc.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.241-250
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• 2018

Online recruitment services have emerged as one of the most popular Internet services, providing job seekers with a comprehensive list of jobs and a search engine. But many recruitment services suffer from shortcomings due to their reliance on traditional client-pull information access model, in manay cases resulting in unfocused search results. Worldjob+, being operated by The Human Resources Development Service of Korea, addresses these problems and uses Splunk, a platform for analyzing machine data, to provide a more proactive and personalised services. It focuses on enhancing the existing system in two different ways: (a) using personalised automated matching techniques to proactively recommend most preferrable profile or specification information for each job opening announcement or recruiting company, (b) and to recommend most preferrable or desirable job opening announcement for each job-seeker. This approach is a feature-free recommendation technique that recommends information items to a given user based on what similar users have previously liked. A brief discussion about the potential benefit is also provided as a conclusion.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.261-265
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• 2005

This paper describes the DC-DC Converter for Ancillary Power Supply in Hybrid Electric Vehicle. DC-DC Converter is used for charging 12V auxiliary battery supplying electric power to head ramp, audio, ECU etc in automobiles. used DC-DC Converter Topology is PS-ZVS FB(Phase Shifted Zero Voltage Switching Full-Bridge) to reduce switching loss and EMI noise induced by high frequency operating condition. And For easy compensation and stable system response characteristic, current mode control method including slope compensation is employed. Constant current / constant voltage charging control method guarantee stable electric charging of auxiliary battery. Simulation toll PSIM6.0 is used for initial circuit parameter settings and H/W debuging. Thermal problems of Switching components in DC-DC Converter is improved by using Thermo Tracer.

• Korean Architects
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• no.12 s.368
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• pp.31-45
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• 1999

숨가쁘게 달려오던 한국사회는 문득 21세기의 문턱 앞에 서 있다. 지난 한 세기는 한국 뿐만 아니라 세계건축계에도 많은 변화와 발전이 있었다. 이렇다 할 준비없이 우리가 맞이하는 21세기는 정보와 문화가 주도할 것으로 예상된다. 새로운 밀레니엄에 대한 기대와 세기적 전환시대를 맞는 현 시점에서 그동안 한국건축은 급격한 경제성장과 아울러 새로운 서구적 건축의 유입으로 인해 우리는 건축문화에 대한 관심을 기울일 시간도 없이 양적인 성장을 계속해 왔다. 외래건축의 유입으로 인해 한국건축이 겪었던 문화적 충격은 단순한 문화적 충돌이 아니라 기존 도시구조의 대대적인 변형과 파괴에 시달려야 했으며, 이로 인한 불균형한 개발은 급조된 건축물을 생산하는 결과를 초래하게 되었고, 이와 함께 우리 건축문화의 모습은 기형적인 도시환경의 모습으로 대체되었다. 이러한 상황에서 다가올 21세기는 WTO세계무역기구의 발전과 더불어 국가간의 개방정책이 불가피하게 이루어지고 있으며, 이에 따라 사회 전분야에 걸쳐 새로운 시도는 빠르게 움직이고 있다. 건축분야 역시 문호 개방원칙에 따라 국가간 건축사자격 상호인증에 대한 각국간의 심도있는 논의와 그에 따른 교육 및 시험수준, 경력의 요구조건, 제반규제사항 등 각국의 상호 차이점에 대한 구체적인 협의가 올해 열린 UIA(세계건축사연맹) 북경 총회에서 승인되어 표준안이 공포되었다. 이에 따라 우리나라도 건축사자격 상호인증에 대한 대책 마련을 위해 공청회개최 등을 통해 본격적인 논의가 이루어지고 있다. 이제 우리 건축계도 새로운 세기를 맞는 시점에 서 있다. 이러한 상황에서 한국건축계는 급변하는 세계속에 우리의 건축문화를 계승 발전해야 할 과제를 안고 있다. 이에 본지에서는 밀레니엄 특집으로 '21세기 한국건축의 비전'이란 주제로 한국건축의 새천년의 미래를 내다보고 이를 통해 우리 건축이 담고 있는 현실과 문제의 실마리를 풀 수 있는 계기를 마련하고자 이번 특집이 계획되었으며, 또한 한국건축이 나아갈 바람직한 방향을 짚어 봄으로써 한국건축의 활로를 모색하고 세기적 전환시대를 맞는 우리 건축의 미래지향적 자료로 활용되었으면 한다.

• Journal of Sensor Science and Technology
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• v.7 no.4
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• pp.243-253
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• 1998

PVC membrane, which has been used for membrane of electrolyte sensors, shortened sensor lifetime due to poor adhesion to sensor surface and exhibited difficulty in standardization and mass-production. To overcome these problems, the membrane solution was prepared with neutral carrier, matrix(TEOS:DEDMS=1:3), solvent(ethanol), and a catalyzer(HCl). The fabricated electrolyte sensors showed typical electrical characteristics of MISFET (metal-insulator-semiconductor field-effect transistor). The K-, Ca- and Na-ISFETs showed sensitivity of 53, 25 and 50 mV/decade in wide concentration range, respectively. The response time was about 90 seconds and the drift was 0.05mV/hour. These results suggest that the sol-gel method and the lift-off technique can be applied to formation of membranes and expected to improve mass-productivity, standardzation of the sensors.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.105-108
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• 1996

Microbial and sensory changes during storage at $4^{\circ}C$ of Angelica keiskei juice pressurized at $5700\;kg_f/cm^2$ for 7 min, an optimum process condition suggested from the previous study, were investigated. Pseudomonas, which is responsible for putrefaction of refrigerated food, was totally inactivated by pressurization. E. coli and coliform bacteria were also completely inactivated. According to the sensory evaluation data, high hydrostatic pressure does not change sensory characteristics of freshness, sweetness and bitterness (P<0.05). However, after 8 day storage at $4^{\circ}C$, pressurized Angelica keiskei juice showed higher freshness than untreated control. These results indicated that the high hydrostatic pressure can be used as an effective process method for preserving Angelica keiskei juice.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.25-25
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• 2009

종래의 위보기 자세에서 용접은 중력이 모재의 표면으로 향하고 있어 용융금속이 중력에 의해 표면방향으로 흘러내리게 되어 용접 실시가 불가능하였다. 이에 Shield Gas Force, Trailing Gas Force 그리고 Ahead Gas Force를 적절히 적용하여 Position Welding에서 중력으로 인해 Molten Metal이 처지는 문제를 극복하여 생산성 향상으로 연결할 수 있음을 선행 실험을 통해 확인하였으나 기존의 C(Convergent)형, CP(Convergent Divergent)형 및 P(Parrallel)형 가스 노즐은 용접조건에 따라 실드 가스의 소모량이 많고, 토출되는 실드가스력이 부족하여 용접시 볼록한 이면 비드 형성을 위한 용융 풀을 효과적으로 제어 할 수 없다. 따라서 본 연구에서는 동일량의 실드 가스 공급시 가스 노즐을 통해 토출되는 실드가스의 소모를 줄이고 실드가스력을 극대화하여 저가의 고생산성을 가진 친 환경 용접기술(Green welding)에 부합하는 CDP(Convergent Divergent Parrallel)형 가스 노즐을 제작하여 기존의 CP형 가스 노즐과 비교 분석하였다. 또한 Overhead Position에서의 비드형상제어와 Flat Position에서 방풍효과를 비교해 보았다. 그 결과 CDP Nozzle은 CP Nozzle보다 동일한 유량에서 풍속은 3.5배, 냉각능력은 1.5배, 가스압력은 6.25배로 우수한 성능을 확인할 수 있었고, Overhead Position에서 가스 유량을 동일하게 하여 용접하였을 때 CP Nozzle의 경우 오목한 이면비드가 나타났지만 CDP Nozzle의 경우 볼록하게 양호한 이면비드 형상이 나타났고, Flat Position에서의 방풍효과 비교실험에서 CDP Nozzle에서는 깊고 균일한 용입을 CP Nozzle에서는 불안정한 용입이 나타났는데 이는 CDP Nozzle의 경우 풍속에 의한 Arc Blow가 적게 발생하여 상대적으로 더 나은 용입을 확인하였다.