• 전기의세계
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• 제25권6호
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• pp.69-73
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• 1976

Thd idle channel noise on FDM-microwave communication system is increasing because of the up-grade to wide-band loading. The thermal noise on receiver of microwave radio is measured according to their channel slot frequencies, low, meddle and high slots on the base band, from 60 channels to 960 channels. And suggested a consideration for system engineering, to reduce the thermal noise from radio microwave receivers, so as to improve signal to noise ratio.

• 항공우주시스템공학회지
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• 제4권1호
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• pp.27-31
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• 2010

The scope of this paper is to analyze the safety aspects of the Ka-band payload system which are associated with testing, transportation, integration, handling and storage. According to ESA philosophy and the ECSS-Q-40A "Space Product Assurance - Safety", safety hazard analysis of Ka band payload was performed. In this paper, it is indicated the requirements to be satisfied for eliminating, reducing, or controlling the hazards and by showing how they have been implemented in the COMS design. And it shows the safety hazard analysis result which has performed the analysis according to ESA document and also shows the potential hazard cause, potential effects, hazard grade and criteria resolution of Ka band COPS.

• 한국군사과학기술학회지
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• 제26권3호
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• pp.227-233
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• 2023

In this paper, to substitute the existing TWTA(Travailing Wave Tube Amplifier) component in small radar system, we developed the Ku band SSPA(Solid-State Power Amplifier) based on the fabrication of power MMIC (Monolithic Microwave Integrated Circuit) chips. For the development of the 500 W SSPA, the 40 W-grade power MMIC was designed by ADS(Advanced Design System) at Keysight company with UMS GH015 library, and was processed by UMS foundry service. And 70 W main power modules were achieved the 2-way T-junction combiner method by using the 40 W-grade power MMICs. Finally, the 500 W SSPA was fabricated by the wave guide type power divider between the drive power amplifier and power modules, and power combiner with same type between power modules and output port. The electrical properties of this SSPA had 504 W output power, -58.11 dBc spurious, 1.74 °/us phase variation, and -143 dBm/Hz noise level.

• 교육시설 논문지
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• 제21권1호
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• pp.23-32
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• 2014

Aim of this research is suggesting a satisfied studying space for lecturer, student and curriculum by abstraction of improvement plan which based on investigation and analysis of the space that teacher is using in lecturer and study support facility in school which managed in 'Department system'. This research focused on analyse of teacher's laboratory, teacher's room, and common room in middle and high school which managed and designed by 'Department system' and registered on 'Seoul office of education' and designed in management of department system between 2009 and 2012. With these process, a conclusion of this research is as in the following. Firstly, plan of teachers' private place which is efficient and stable is required through to get out of module which can cover subject band and grade band. Secondly, we have to focus on size of teachers' convenience facilities for convenience or official usage, movement radius, and improvement of working environments. Thirdly, 'Subject type teachers' laboratory' which organized by teachers who teach same subject is more efficient than 'Task type laboratory' which organized by teachers who working on same task for management of school. In fourth, 'Task type teachers' laboratory' arranged regardless with teachers' class room to teach, and it makes lack of connectivity between teacher and class room.

• 대한수학교육학회지:학교수학
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• 제14권4호
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• pp.531-552
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• 2012

2009 개정 교육과정에 따른 수학과 교육과정의 적용은 초 중학교의 경우 2013년부터이며 연차적으로 확대 적용될 전망이다. 새 교육과정의 적용이 시작되는 현 시점에서 '2009 개정 교육과정 총론'과 '2009 개정 교육과정에 따른 수학과 교육과정'이 유기적으로 연계하여 적용될 수 있도록 다각적인 검토를 통해 수학과 교육과정을 적용하는 데 발생하는 어려움, 즉 쟁점을 신중히 탐색하고 이에 대한 해결 방안을 마련할 필요가 있다. 수학과 교육과정 적용 시, 쟁점이 되는 항목은 2009 개정 교육과정 총론의 변화에 따른 것으로, 이는 학년군, 수준별 수업, 기준 수업시수의 20% 이내 증감 운영으로 구체화 할 수 있다. 본고에서는 이 세 가지의 쟁점 사항을 중심으로 수학과 교육과정을 적용하는데 있어서의 효율적인 방안을 모색하고자 하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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• pp.33-37
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• 2001

Recently, the HFPD measurement testing is widely used in partial discharge measurement of HV machines because HFPD measurement testing receives less influence of external noise and has a merit of good sensitivity. Also HFPD testing is able to offer the judgement standard of degradation level of HV machine and can detect discharge signals in live-line. Therefore it is very useful method compare to previous conventional PD testing method and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 센서 박막재료
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• pp.66-70
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• 2001

The partial discharge testing is widely used in diagnostic measuring technology because it gives low stress to power equipment which is undertaken tests. Therefore it is very useful method compare to previous destructive methods and effective diagnosis method in power system that requires on-line/on-site diagnosis. But partial discharges have very complex characteristics of discharge pattern, so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated system is manufactured and HFPD occurred from those simulator is measured with broad-band antenna in real time, the degradation grade of system is analyzed through produced patterns in simulated target according to the AI/statistics processing.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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• pp.18-22
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• 2000

The partial discharge testing is widely used in insulation property measurement because it gives low stress to high voltage equipment which is undertaken tests. Therefore it is very useful method compare to previous destructive methods and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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• pp.29-32
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• 2000

The partial discharge testing is widely used in insulation property measurement because it gives low stress to high voltage equipment which is undertaken tests. Therefore it is very useful method compare to previous destructive methods and effective diagnosis method in power transformer that requires on-line & on-site diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and PD/HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• 대한수학교육학회지:학교수학
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• 제15권4호
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• pp.759-783
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• 2013

학문적 수학으로부터 학교수학으로의 교수학적 변환 과정에서 교육과정과 교과서는 큰 비중을 차지한다. 2009 개정 교육과정에 따른 수학과 교육과정이 적용되기 시작한 현 시점에서 교육과정과 교과서의 연계성에 대한 분석은 중요한 과제이며, 특히 수학과에 새로 도입된 학년군제를 고려할 때 더욱 그러하다. 학년군제는 교육과정 운영상의 유연성뿐만 아니라 수학과 교과 내용의 구성에도 영향을 미쳐 학년군에 따른 성취기준은 학년제일 때에 비해 다소 통합적인 선정이 불가피하였고, 따라서 통합적으로 진술된 교육과정 성취기준이 빠지지 않고 교과서에 담겨져 교육과정의 의도대로 구현되었는가를 파악할 필요가 있다. 본 연구는 교육과정과 교과서의 연계성 파악을 위해 1~2학년군을 대상으로 교육과정 성취기준에 따른 교과서 분석, 교과서 소단원별 학습목표에 따른 성취기준과의 연계 분석, 용어와 기호와 관련한 교과서 분석, 수학적 과정과 관련한 교과서 분석을 실시하고, 그 결과에 기초한 교수학적 논의로부터 교육과정 및 교과서 개발을 위한 시사점을 제안한다.