UNESCO 협력학교의 효과성 분석 연구

조현기(Hyungi Cho) 글로벌교육연구학회 2021 글로벌교육연구 Vol.13 No.3

PISA 2018에서의 글로벌 역량의 혁신 영역 선정을 기점으로 글로벌 교육이 부각되기시작하였다. 글로벌 역량의 중요성이 대두되면서 교육에서 글로벌 역량을 함양시키기 위한연구의 필요성도 함께 제기되었다. UNESCO 협력학교는 현장에서 이루어지고 있는 글로벌교육 관련 활동 중에서 가장 오래되고 보편적으로 이루어지고 있지만 그 효과성에 대한연구는 제대로 이루어지고 있지 않은 상황이다. 본 연구에서는 글로벌 교육의 선구자적인역할을 담당하고 있는 UNESCO 협력학교의 효과성을 PISA 2018의 글로벌 역량을 중심으로 알아보고자 하였다. 본 연구를 위해서 UNESCO 협력학교 6개교와 비교집단으로 일반학교 6개교를 선정하였다. UNESCO 협력학교의 효과를 검증하기 위해 카이제곱검정, 상관분석, 독립표본 t검증을 실시하였다. 또한, 글로벌 역량과 해외거주 경험 사이의 연관성, 글로벌 역량과 해외여행빈도 사이의 연관성을 알아보기 위해 상관분석을 이용하였다. 마지막으로 UNESCO 협력학교와 일반학교 사이의 독립표본 t검증을 통해 유의미한 차이가 있는지 알아보았다. UNESCO 협력학교와 일반학교 사이의 독립표본 t검증에서는 기능 영역과 가치 영역에서유의미한 차이를 보였다. 또한, 글로벌 역량 전체 값으로 분석한 결과에서도 유의미한 차이가 있는 것으로 나타났다. At PISA 2018, global education was highlighted as an innovative area of global competency. As global capabilities become more important, the need to cultivate them has also been raised. The UNESCO partner schools are the oldest and most common among global education-related activities in the field, but studies on their effectiveness have not been conducted properly. In this study, the effectiveness of UNESCO partner schools was investigated with a focus on the global capabilities of PISA 2018. For this study, six UNESCO cooperative schools and six general schools were selected. To verify the effectiveness of UNESCO partner schools, chi-square test, correlation analysis, and independent sample t-test were performed. Exogenous variables were removed through chi-square test and correlation analysis. The effectiveness was investigated through independent sample t-test between UNESCO partner schools and general schools. In addition, in the independent sample t-test, there was a significant difference in function and value, and there was also a s ignificant d ifference in t he o verall valu e of global competency.

W.I.T.H 세계시민교육을 통한 공동체 역량 신장

조현기(Hyungi Cho) 글로벌교육연구학회 2017 글로벌교육연구 Vol.9 No.2

이 연구는 초등학생들의 공동체 역량을 신장시키기 위해 W.I.T.H 세계시민교육 프로그램을 개발하여 적용하였다. 연구자 학급에는 학교 생활에 적응하지 못하는 학생, 마음에 상처를 담고 있는 학생, 자기중심적으로 행동하는 학생 등 다양한 학생들이 여러 어려움을 가지고 있었다. 이에 연구자는 학생들이 공동체 생활을 보다 원활하게 할 수있도록 초등학생들의 공동체 역량을 신장시키는 것에 목적을 두었다. 또한, 공동체 역량 신장을 위해 W.I.T.H 세계시민교육 프로그램을 구안 및 적용하여 그 효과를 검증하도록 하였다. 이 프로그램은 여건 조성과 본 프로그램으로 나눠서 진행되었으며 적용 후에는 결론 도출을 위한 반성적 검토 과정을 거쳤다. 프로그램은 5개 영역, 15개 주제로 구성되어 있으며 세계시민교육 목표와 공동체 역량 목표로 수업이 진행된다. 반성적 검토 과정에서는 양적 검증과 이를 보완하기 위한 질적 검토로 이루어져 있다. 양적 검증은 연구자가 자체 제작한 초등학생 공동체 역량 검사를 통해 사전 검사와 사후 검사를 비교 분석한다. 질적 검토는 양적 검증을 보완하기 위해 심층면담, 소감문 분석 으로 진행하였다. 연구결과 연구자는 학생들의 공동체 역량을 신장시키기 위해서는 방법적인 측면과 내용적인 측면 두 가지 모두가 병행되어야 한다는 사실을 알았다. 또한, 함께하는 삶을 공부하는 과정에서 학생들의 공동체 역량은 자연스럽게 발전하고 성장 하였다. 후속 연구로는 공동체 역량 증진을 보다 효과적으로 이루기 위해 사춘기 학생들을 위한 공동체 프로그램을 함께 진행하는 것과 W.I.T.H 모형의 정련화하는 과정이 필요하다고 본다. This researcher developed and applied W.I.T.H Global Citizenship Education Program to enhance the community competence of elementary school students. In the researcher class, a variety of students who could not adjust to school life, with heart injuries, and acted self-centered, had various difficulties. The purpose of this research is to enhance the community competence so that they can make their life more comfortable. In addition, this program was designed and applied to verify the effectiveness. This program was divided into two categories: the creation of conditions and the program. The program consists of 5 areas and 15 themes. The course is taught with the goals of global citizenship education and community competence. As a result of this research, I found that both the methodical and the content aspects must be combined in order to enhance the students community competence. In addition, in the process of studying living together, the students community competence naturally developed and grew. Based on this, I think it is necessary to carry out a community program for adolescent students together with a process of refining the W.I.T.H model in order to achieve community competence more effectively.

GTM의 SPE 모듈 사용여부에 따른 BLDC 모터 구동을 위한 6-스텝 구동 수행 시간 분석

조현기(Hyungi Cho),장재환(Jeahwan Jang),정구민(Gumin Jeong) 한국자동차공학회 2017 한국자동차공학회 부문종합 학술대회 Vol.2017 No.5

500℃ 터빈 입구 조건의 수백 kWe급 초임계 이산화탄소 발전시스템 테스트루프 개발 연구

조준현(Junhyun CHO),신형기(Hyungi SHIN),조종재(Jongjae CHO),최봉수(Bongsu CHOI),노철우(Chulwoo ROH),이길봉(Gilbong LEE),이범준(Beomjoon LEE),나호상(Ho-Sang RA),백영진(Young-Jin Baik) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

KIER has developed a hundreds of kWe-class supercritical carbon dioxide power cycle (SCO₂) test loop for distributed heat sources such as biomass and waste heat recovery. A 120 kWe dual Brayton cycle which consists of two turbines, a compressor, two recuperators, a flue-gas heater and a cooler was developed and optimized. The turbine and compressor inlet conditions are 500℃/130bar and 35℃ /77bar, respectively. The low temperature turbo-generator was already manufactured and tested in 2017 successfully, it was developed as an axial impulse type turbine with a carbon-ring type mechanical seal and oil-lubricated tilting-pad bearings. A centrifugal type of compressor with a dry gas seal (DGS) and oil-lubricated tilting-pad bearings was developed. To reduce leakage flow, the DGS and its flow control system were manufactured. A LNG-fired flue gas heater which consists of a burner and shell-and-tube type heat exchanger was manufactured. A temperature of 650℃ flue gas was generated to heat carbon dioxide up to 500℃ at 130bar condition. Two PCHE type recuperators and one PCHE type cooler were manufactured. A piping stress analysis was conducted and a high temperature expansion joint was used at the flue-gas heater to mitigate thermal expansion. A full test loop would be constructed and operated in next year.

500℃ 터빈 입구 조건의 수백 kWe급 초임계 이산화탄소 발전시스템 테스트루프 개발 연구

조준현(Junhyun Cho),신형기(Hyungi Shin),조종재(Jongjae Cho),최봉수(Bongsu Choi),노철우(Chulwoo Roh),이길봉(Gilbong Lee),이범준(Beomjoon Lee),나호상(Ho-Sang Ra),백영진(Young-Jin Baik) 대한기계학회 2019 大韓機械學會論文集B Vol.43 No.9

한국에너지기술연구원에서는 바이오매스 및 폐열과 같은 분산 전원에 적합한 수백 kWe급 초임계 이산화탄소 발전사이클 테스트루프를 개발 중에 있다. 터빈 2기, 압축기, 복열기 2기, 연소배가스 이용 히터로 구성된 120kWe 용량의 이중 브레이튼 사이클을 개발하였으며, 목표 터빈 입구 조건은 500℃/135bar이다. 미캐니컬 씰과 틸팅패드 베어링으로 구성된 충동형 축류 터보-발전기는 2017년에 이미 제작, 시험을 성공적으로 완료하였다. 다음 단계로 드라이가스씰(DGS)이 적용된 원심형 압축기를 개발하였으며, 버너와 쉘앤튜브 열교환기로 구성된 650℃의 연소배가스 이용 히터를 제작하고, ASME 기준에 따라 배관 설계를 진행하였다. 전체 테스트루프는 올해 완성 및 운전을 목표로 하고 있다. KIER has being developing hundreds of kWe-class supercritical carbon dioxide power cycle test loops for distributed heat sources such as biomass and waste heat recovery. A 120 kWe dual Brayton cycle which consists of two turbines, a compressor, two recuperators, a flue-gas heater, and a cooler was developed. The target operating turbine inlet condition is 500 ℃/135 bar. An axial impulse-type turbogenerator with a mechanical seal and tilting-pad bearings was successfully manufactured and tested in 2017. As the next phase, a centrifugal-type compressor with a dry gas seal was developed. A 650 ℃ LNG-fired flue gas heater, which consists of a burner and shell-and-tube type heat exchanger, was manufactured. Piping design is carried out according to ASME standards. Full test loop will be constructed and operated in 2019.

축류형 초임계 이산화탄소 터보발전기 구동을 위한 테스트루프 개발 및 운전 연구

조준현(Junhyun CHO),신형기(Hyungi SHIN),조종재(Jongjae CHO),노철우(Chulwoo ROH),이길봉(Gilbong LEE),이범준(Beomjoon LEE),최봉수(Bongsu CHOI),나호상(Ho-Sang RA),백영진(Young-Jin Baik) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

To overcome reported failure problems of the turbomachinery for the supercritical carbon dioxide power cycle induced by the high rotational speed and the axial force, an axial impulse type turbo-generator with a partial admission nozzle was designed and manufactured to reduce the rotational speed as well as the axial force. Then, a turbine wheel part was separated by the carbon ring type mechanical seals to use the conventional oil-lubricated tilting-pad bearings. To drive the turbo-generator, a simple transcritical cycle using a liquid CO2 pump was constructed. A 600,000 kcal/h LNG fired thermal oil boiler and a 200 RT chiller were used as a heat source and heat sink. A target turbine inlet temperature and pressure were 200 °C and 130 bar, respectively. Two printed circuit heat exchangers were manufactured for both sides of the heater and cooler. A leakage make-up system by using a reciprocating CO2 compressor, a CO2 supply valve-train to the main loop and the mechanical seal, an oil cooler for the bearings, a load bank and control systems were installed. Before turbine power generating operation, a turbine bypass loop was operated by using an air-driven control valve to determine the system mass flow rate and to make turbine inlet conditions. Then, a 11 kW electric power was obtained under 205 °C and 100 bar of turbine inlet conditions and a continuous operating time was 45 minutes.

Improvement of reduction method combined with sub-domain scheme in large-scale problem

Kim, Hyungi,Cho, Maenghyo John Wiley Sons, Ltd. 2007 International Journal for Numerical Methods in Eng Vol.70 No.2

<P>For a few decades, various approximate techniques have been developed to calculate the eigenvalues in a reduced manner. In order to construct reliable reduced systems it is essential to select the proper primary degrees of freedom (PDOFs). Unless the PDOFs are selected properly, the selection of PDOFs might be localized and the eigenvalue prediction might emphasize excessively the lower modes or lose the important modes. Moreover, sometimes, it takes considerable amount of computing time to construct a reduced system in large-scale problem. These troubles in constructing reduced system can be avoided by applying reduction scheme in sub-domain level. After dividing global system into a number of sub-domains, reduced system which has only the PDOFs is constructed in each sub-domain. This paper presents new algorithms to construct efficient reduction system through three different schemes. They are version 1, version 2 and version 3 systems. The version 3 system is constructed by combining the advantages of the version 1 and the version 2 systems. Numerical examples demonstrate that the proposed version 3 method saves computational cost effectively and provides a reduced system which can predict accurate eigenvalues of global system. Copyright © 2006 John Wiley & Sons, Ltd.</P>

고유치 문제에서 요소단위에 기초한 축소모델의 구성에 관한 연구

김현기(HyunGi Kim),조맹효(Maenghyo Cho) 대한기계학회 2002 대한기계학회 기타 간행물 Vol.2002 No.11

보조변수법과 복소변수를 연동한 설계 민감도 해석 연구

김현기(Hyungi Kim),조맹효(Maenghyo Cho) 대한기계학회 2009 大韓機械學會論文集A Vol.33 No.3

The adjoint variable method can reduce computation time and save computer resources because it can selectively provide the sensitivity information for the positions that designers wish to measure. However, the adjoint variable method commonly employs exact analytical differentiation with respect to the design variables. It can be cumbersome to precisely differentiate every given type of finite element. This trouble can be overcome only if the numerical differentiation scheme can replace this exact manner of differentiation. But, the numerical differentiation scheme causes of severe inaccuracy due to the perturbation size dilemma. For assuring the accurate sensitivity without any dependency of perturbation size, this paper employs a complex variable that has been mainly used for computational fluid dynamics problems. The adjoint variable method combined with complex variables is applied to obtain the shape and size sensitivity for structural optimization. Numerical examples demonstrate that the proposed method can predict stable sensitivity results and that its accuracy is remarkably superior to traditional sensitivity evaluation methods.

주자유도 선정 기법에 의한 동하중의 등가 정하중으로의 변환

김현기(Hyungi Kim),조맹효(Maenghyo Cho) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11

The systematic method to construct equivalent static load from the given dynamic load is proposed in the present<br/> study. Previously reported works to construct equivalent static load were based on ad hoc methods. They may results in<br/> unreliable structural design. The present study proposes a selection scheme of degrees of freedom(d.o.f) for imposing<br/> the equivalent static loads. The d.o.fs are selected by Two-level condensation scheme(TLCS). TLCS consists of two<br/> two-steps. The first step is the energy estimation in element-level and the second step consists of the traditional<br/> sequential elimination precudure. Through several numerical examples, the efficiency and reliability of proposed<br/> scheme is verified.