• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.61-63
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• 2004

Focus Electrode(FE) 기능을 갖는 진행파관 증폭기(TWTA)를 구동하기 위하여 고전압 펄스전원 장치가 필요하다. 이 전원장치는 영부터 -5.0 kV TWT 캐소드 고전압 위에서 펄스 출력으로 동작 되어야 한다. 고전압펄스전원장치는 바이어스 전압이 영부터 -1.5 kV 사이를 연속적으로 가변 할 수 있어야 하고, 펄스의 반복 주파수는 CW로 부터 1 kHz 그리고 펄스폭은 $10\;{\mu}s$ 부터 $500\;{\mu}s$로 선택 가능하여야 한다. 그리고 출력펄스의 상승 및 하강 시간은 150 ns 보다 작아야 한다. 턴-온 및 오프의 스윗칭 시간을 만족시키기 위하여 고전압 스위치는 직렬로 연결된 FET 모듈을 사용하였다. 본 논문에서는 이러한 고전압 펄스전원장치의 설계 및 제작원리 그리고 시험결과에 대하여 다루었다.

• Asian Journal of Business Environment
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• 제4권3호
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• pp.13-18
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• 2014

Purpose - This study examines students' perspectives (stream-wise) of parameters affecting education quality in an affiliated undergraduate engineering institution in NCR, Haryana. Research design, data, and methodology - This study involves descriptive research and data collection using a structured questionnaire based on the Likert scale. The sample comprises 500 student respondents. For data analysis, an f-test was performed using high quality SPSS software. Results - For "Selection" and "Personality Development & Industry Exposure," the analysis of variance revealed a statistical difference between the mean values of the groups. Whereas, for "Academic Excellence," "Infrastructure," "Placements," and "Management & Administration," the analysis of variance revealed no statistical difference between the mean values of the groups. Conclusions - Students' perceptions about the "Selection" and "Personality Development & Industry Exposure" change according to the various specializations they opt for in their undergraduate engineering education in Haryana. Whereas, for "Academic Excellence," "Infrastructure," "Placements," and "Management & Administration," the perceptions of the students do not vary because of the different specializations they have opted for in their undergraduate engineering education.

• 전자공학회논문지B
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• 제33B권7호
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• pp.70-79
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• 1996

To increase the functionality of the memories, previous studies have deifned faults models and proposed functional testing algorithms with low complexity. Although conventional testing depended strongly on functional (voltage) testing method, it couldn't detect short and open defects caused by gate oxide short and spot defect which can afect memory reliability. Therefore, IDDQ (quiescent power supply current) testing is required to detect defects and thus can obtain high reliability. In this paper, we consider resistive shorts on gate-source, gate-drain, and drain-source as well as opens in mOS FET and observe behavior of the memory by analyzing voltage at storge nodes of the memory and IDDQ resulting from PSPICE simulation. Finally, using this behavioral analysis, we propose a linear testing algorithm of complexity O(N) which can be applicable to both functional testing and IDDQ testing simultaneously to obtain high functionality and reliability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1184-1186
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• 2004

Focus Electrode(FE) 기능을 갖는 진행파관 증폭기(TWTA)를 구동하기 위하여 고전압 펄스전원 장치가 필요하다. 이 전원장치는 영부터 -5.0 kV TWT 캐소드 고전압 위에서 펄스 출력으로 동작되어야 한다 고전압펄스전원장치는 바이어스 전압이 영부터 -1.5 kV사이를 연속적으로 가변 할 수 있어야 하고, 펄스의 반복 주파수는 CW로 부터 1 kHz 그리고 펄스폭은 $10\;{\mu}s$부터 $500\;{\mu}s$로 선택 가능하여야 한다. 그리고 출력펄스의 상승 및 하강 시간은 150 ns 보다 작아야 한다. 턴-온 및 오프의 스윗칭 시간을 만족시키기 위하여 고전압 스위치는 직렬로 연결된 FET 모듈을 사용하였다. 본 논문에서는 이러한 고전압 펄스전원장치의 설계 및 제작원리 그리고 시험결과에 대하여 다루었다.

• 한국전기전자재료학회논문지
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• 제22권12호
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• pp.1009-1013
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• 2009

In this study, we have been synthesized the dielectric layer using pure organic and organic-inorganic hybrid precursor on flexible substrate for improving of the organic thin film transistors (OTFTs) and, design and fabrication of organic thin-film transistors (OTFTs) using small-molecule organic semiconductors with pentacene as the active layer with record device performance. In this work OTFT test structures fabricated on polymerized substrates were utilized to provide a convenient substrate, gate contact, and gate insulator for the processing and characterization of organic materials and their transistors. By an adhesion development between gate metal and PI substrate, a PI film was treated using $O_2$ and $N_2$ gas. The best peel strength of PI film is 109.07 gf/mm. Also, we have studied the electric characteristics of pentacene field-effect transistors with the polymer gate-dielectrics such as cyclohexane and hybrid (cyclohexane+TEOS). The transistors with cyclohexane gate-dielectric has higher field-effect mobility, $\mu_{FET}=0.84\;cm^2/v_s$, and smaller threshold voltage, $V_T=-6.8\;V$, compared with the transistor with hybrid gate-dielectric.

• Structural Engineering and Mechanics
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• 제83권1호
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• pp.19-29
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• 2022

The angle steel frame confined concrete columns (ASFCs) are an emerging form of hybrid columns, which comprise an inner angle steel frame and a concrete column. The inner angle steel frame can provide axial bearing capacity and well confining effect for composite columns. This paper presents the experimental and theoretical studies on the seismic behaviour of ASFCs. The experimental study of the 6 test specimens is presented, based on the previous study of the authors. The theoretical study includes two parts. One part establishes the section analysis model, and it uses to analyze section axial force-moment-curvature. Another part establishes the section moment-curvature hysteresis model. The test and analysis results show that the axial compression ratio and the assembling of steel slabs influence the local buckling of the angle steel. The three factors (axial compression ratio, content of angle steel and confining effect) have important effects on the seismic behaviour of ASFCs. And the theoretical model can provide reasonably accurate predictions and apply in section analysis of ASFCs.

• 대한전자공학회논문지TC
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• 제41권2호
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• pp.65-70
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• 2004

본 논문에서는 비선형 RF(Radio Frequency) 증폭기의 선형화를 위한 새로운 구조의 전치왜곡 선형화기를 제안한다. 전치 왜곡에 이용되는 3차 비선형 성분은 RF 신호의 포락선(envelope) 전력을 이용하여 발생시킨다. 3차 왜곡 성분 발생기(3rd order distortion generator)는 FET로 구성되었고, 왜곡 신호 발생 후 남아 있는 주 신호 성분 제거를 위해 평형 결합 구조를 제시하였다. 발생된 3차 혼변조 신호는 RF 대역에서 진폭과 위상을 조절함으로써 최적의 선형화 조건을 만족시킨다. 2-tone 실험결과 증폭기의3차 흔변조특성이 30～40㏈ 개선되었다. IS-95 CDMA 신호 실험 결과 인접 채널 전력 비(ACPR)가 약 l0㏈이상 개선됨을 확인하였다.

• 공학기술논문지
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• 제11권4호
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• pp.267-271
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• 2018

A high-frequency therapy device with improved output by modifying a high-frequency stimulator was fabricated. The details of the design include generating part design, high-frequency transformer design, large output FET installation, DC voltage input part design and gate input driver design. Based on the real test using the pork meat, the temperature distributions according to the current electric transfer method, penetration depth, electrode diameter size were measured. In the CET method, the penetration depth was 0.5 cm and in the RET method, the penetration depth was 20 cm or more. In addition, it was confirmed that the temperature rise according to the penetration depth in the RET system was substantially constant, and the temperature rise was remarkable as the electrode diameter was small. As a result, it has been confirmed that the high frequency therapy device is highly affected by various conditions of the electrode.

• 한국산학기술학회논문지
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• 제13권4호
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• pp.1777-1783
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• 2012

본 논문에서는 DC모터의 출력특성을 개선할 수 있는 새로운 구조의 DC모터 구동회로를 설계하였고 이 회로를 이용한 콘트롤러를 개발하였다. 설계된 구동 회로에 의하여 콘트롤러는 자체발진회로의 스위칭 신호를 갖는 트랜스포머를 이용하여 연속적으로 DC모터를 구동할 수 있다. 또한 최대속도시, 제어회로의 기준전압 값을 삼각파보다 높게 유지할 수 있고 모터 구동 FET를 항상 온 값을 가지도록 하여 최대출력을 얻을 수 있도록 한다. 제안된 구동회로를 활용하여 24V-500W급 DC모터속도 컨트롤러를 개발하였고 소형전동차를 제작하고 구동시험을 실시하였다. 구동테스트 및 특성 측정결과, 구동전류 12A로써 DC모터의 전진 및 후진 속도를 연속 가변 할 수 있음을 보였다. 그 밖에 과전류 감시기능, 모터과열 감시기능의 정상동작을 확인하였으며, 배터리 잔량이 20~100%까지 6단계로 표시할 수 있음을 확인하였다.

• 대한한의학회지
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• 제26권3호
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• pp.13-26
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• 2005

Objectives : Applying herbal-acupuncture using Ursi Fet into Zusanli (UZ) on to the atopic dermatitis (AD) in mice to study changes in external dermal formation, change of leukocytes in vasculature, change of lipid formation in stratum corneum and distribution of ceramide. This study was done through forcing an injury to the mice's back skin which damages the lipid protection formation in the stratum corneum. Methods : The AD which was caused intentionally using the external application on the mice's back skin was treated with VB; the change of leukocytes in the vasculature was identified through optima 5.2 and Student's t-test and the results were made into a dermal formation graph. Results : After dispensing UZ into the AD, the dermal injury decreased. The recovery of the lipid protection formation which includes lipid and ceramide in the stratum comeum (for suppressing acute inflammation due to factors such as PKC, $TNF-\alpha,\;IL-1\beta$, which controlled the secretion of the relating inflammatory cytokine) also went on to show a decrease of both angiogenesis and degranulated mast cells. In addition, the decrease of epithelial injury also caused the growth of cells to decrease in the stratum basale and cytoclasis. In the vasculature, the leukocytes were also decreased na this could relate to a decrease in AD. Conclusions : UZ has an effect on AD by suppressing dermal injury through the recovery of the lipid protection formation in the stratum corneum.