Hardware Implementation of GaN-HEMT Based ZVS DC–DC Converter Considering PCB Layout

김종수,김현빈,이병국,김종수 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.1

The gallium nitride high electron mobility transistors (GaN HEMT) are among the most promising power semiconductor devices. However, these transistors have a small gate voltage margin compared with conventional power devices. In this paper, the gate voltage of GaN HEMTs is mathematically analyzed when it is applied to a zero voltage switching (ZVS) phase-shift full bridge (PSFB) DC–DC converter. The analysis accounts for nonlinear capacitance characteristics under the ZVS switching condition, and a critical parasitic inductance are derived to restrict the gate voltage to a safety operation area. The optimal layout for bridge topologies and gate drivers is proposed, to satisfy the derived parasitic inductance limitation. A 500-W-power laboratory phase-shift full-bridge DC–DC converter is implemented to verify the proposed layout.

김종수의 삶과 음악 증언

김종수 한국음악문헌학회 2018 음악문헌학 Vol.- No.9

준원자층 적층 방법으로 형성된 2형 양자점의 광 발광 특성 연구

김종수,조현준,소모근,김종수,김영호,이상준,이승현,Christiana B. Honsberg,김희대 한국물리학회 2019 새물리 Vol.69 No.8

We have studied the optical properties of InAs/GaAsSb submonolayer quantum dots (SML-QDs) through excitation intensity (Iex) and temperature dependent photoluminescence (PL) experiments. The SML-QDs with type-I (T-1) and type-II (T-2) band structures were grown using a GaAsSb spacer with a Sb composition of 0% and 15.8%. At 13 K, the PL signals from the T-1 and the T-2 samples were observed at 1.42 eV and 1.37 eV, respectively, when the Iex was 8.7 mW/cm2. The PL signal of the T-1 sample is due to the recombination of electrons and holes in the InAs SML-QDs. The PL signal of the T-2 sample is due to the recombination of electrons (in the GaAs electron band) and holes (in the GaAsSb spacer hole band) by type-II band alignment formed between GaAs and GaAsSb. The full widths at half maxima (FWHMs) of the T-1 and the T-2 samples were 7.09 meV and 24.6 meV, respectively, because the T-2 sample has a lower uniformity than the T-1 sample. As the excitation intensity was increased, the PL signals of the T-1 and the T-2 samples shifted to lower energy because of the quantum-confined Stark effect. As a result of these temperature-dependent PL experiments, the activation energy of the T-1 sample was found to be 30 meV. InAs/GaAsSb submonolayer 양자점(SML-QD)의 광학적인 특성을 여기광 세기(Iex)와 온도에 따른광발광 (Photoluminescence; PL) 실험을 통하여 연구하였다. 본 연구에 사용된 시료는 간격자인 GaAsSb 층의 Sb조성을 0%와 15.8%로 조절하여 Type-I (T-1) 과 Type-II (T-2) 밴드 구조의 SML-QD를 성장하였다. 13 K에서 Iex 가 8.3 mW/cm2 일 때 T-1과 T-2 시료의 PL신호는 각각 1.419 eV와 1.368 eV 에서 관측되었다. T-1 시료에서 관측된 전이신호는 InAs SML-QD의 전자와 정공간의 재결합에 의한것이다. T-2시료에서 관측된 PL신호는 GaAs와 GaAsSb 사이에 형성된 type-II 밴드 정렬에 의하여GaAs 전도대의 전자와 GaAsSb 간격자의 가전자대의 정공간의 재결합에 의한 것이다. 두 신호의 반값온폭 (Full-width at half maximum; FWHM)은 각각 7.09 meV와 24.6 meV 이었으며, 이는 T-2시료가T-1시료보다 균일성이 낮기 때문으로 사료된다. 여기광의 세기가 증가할수록 T-1와 T-2시료의 PL신호는낮은 에너지 쪽으로 이동하였는데, 이는 구속된 운반자에 의한 양자 구속 스타크 효과(quantum-confined Stark effect) 에 의한 것으로 사료된다. 온도 의존성 PL 실험의 결과, T-1 시료의 SML-QD의 활성화에너지는 30 meV이었다.

자기구성 퍼지 제어기법에 의한 AMI 로봇의 위치 및 속도 제어

김종수,정윤교,한성현,이진,장영희 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

In this paper, it is presented a new technique to the design and real-time implementation of fuzzy control system based-on digital signal processors in order to improve the precision and robustness for system of industrial robot. Fuzzy control has emerged as one of the most active and fruitful areas for research in the applications of fuzzy set theory, especially in the real of industrial processes. In this thesis, a self-organizing fuzzy controller for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variable of the controller, In the synthesis of a FLC, one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult, SOFC is proposed for a hierarchical control structure consisting of basic level and high level that modify control rules.

한외여과에 의한 용존 유기물의 분자량 분포

김종수,서준원 선문대학교 첨단과학기술연구소 1999 첨단과학기술연구소 논문집 Vol.4 No.-

정수와 폐수의 고도처리 시스템 설계와 운전에 있어서 용존 유기믈 분자량 분포에 관한 정보는 매우 중요 하다 UF박의 분획분자량과 분자량 분포 결정을 위한 UF시스템을 검증한 결과 시판되는 UP막의 분확 분자량은 실험상의 분획분자량과 유사한 값을 보여 주었다

High Efficiency Organic Photovoltaics using Preformed Poly 3-(hexylthiophene) Nanowires

김종수,이지황,박종환,심명선,심치영,조길원 한국고분자학회 2009 한국고분자학회 학술대회 연구논문 초록집 Vol.2009 No.10

폴리설폰 중공사막에 대한 산소/질소 혼합물의 분리

김종수,송근호,이광래 江原大學校 附設 環境硏究所 1999 環境硏究 Vol.16 No.-

국내 K-그룹 연구소에서 제조한 폴리설폰 중공사막의 산소/질소 혼합물에 대한 압력, stage cut, 공급기체 혼합물의 조성에 따른 분리성능을 조사하였다. 본 실험의 압력범위와 온도 30℃에서의 이상분리인자(O₂/N₂)는 5.7이었으며, 유입기체 혼합물의 21 mole% 산소농도가 약 50 mole%로 농축되었다. 저압츠과 고압측의 압력비는 산소농축에 미치는 영향이 적었으며, 이상분리인자의 영향은 매우 컸다. 그러나, 이상분리인자가 증가함에 따라 이상분리인자의 영향은 둔화되었다. 따라서, 이상분리인자가 큰 신소재 개발과 더불어 공정변수의 최저화가 필요하다. 수학적 모델링에 의한 예측치와 실험치가 잘 맞았다. The performance of the polysulfone hollow-fiber membrane manufactured by K-group Research Institute in Korea was investigated for the separation of O₂/N₂mixture as a function of pressure, stage cut, and feed gas composition. The ideal separation factor(O₂/N₂) at temperature 30℃ was around 5.7 in the pressure ranges studied. Oxygen concentration of 21 mole% in feed stream was concentrated to about 50%. Although the pressure ratio between high and low pressure side showed little effect, ideal separation factor showed greater effect on the oxygen enrichment. However, the effect was declined with increase in the ideal separation factor. Therefroe, the optimization of process variable is necessary as well as development of new material with high ideal separation factor. It was fond that experimental data were well correlated with the prediction of mathematical model.

두개강내 유표피종의 수술적 치료성적

김종수,정희원,이선호,정영섭,김현집,최길수,한대희 대한신경외과학회 1995 Journal of Korean neurosurgical society Vol.24 No.8

Fifteen patients with intracranial epidermoid cysts underwent microsurgical resection between January, 1980 and June, 1994. The average age of the patients was 38.9 years and the male to female ratio was 3 : 2. The most frequent location was the cerebellopontine angle(9) and other locations included parasellar(2), sylvian fissure(1), paratrigeminal(1), pineal(1) and parasagittal(1). Common clinical presentations were cranial nerve impairment and mass effect. Gross total removal was possible in 8 cases. During 57.9 months of mean follow up period there were 5 recurrences, one of which occurred after a complete surgical resection and the others were symptomatic recurrences after incomplete removal. The mean duration from the first operation to reoperation was 8 years and 3 months(2^(+10)-13^(+8) years). In every case of incomplete removal or even in complete removal cases, regular MRI follow up should be done for early detection of recurrence.

국내 출판유통 정보화 실태

김종수,박윤규,박정식,이재영 성공회대학교 2000 성공회대학논총 Vol.- No.15

디스크형 캠기구 설계를 위한 순간속도중심설계법의 연구

신중호,김종수 國立 昌原大學校 産業技術硏究所 1994 産技硏論文集 Vol.8 No.-

As direct contact mechanisms, cam and follower mechanisms are used commonly in many machinery. Disk-typed cam mechanisms have 4 different types due to the different type of followers, such as reciprocating roller type, reciprocating flat-face type, oscillating roller type, and oscillating flat-face type. Depending on the shape of cam and type of follower, the motion of cam-follower mechanism is determined. Thus design procedure must be well defined for determining acculately the shape of cam corresponding to the given motion of follower. In this paper, an instant velocity center method is proposed. This method calculates the instant velocity centers of cam and follower in contact motion at any time. From geometric relationships on contact points of cam with follower, cam shape can be determined using the instant velocity centers. Also this paper presents 4 different cams for demonstration of the proposed design method and the results gives the exact solutions of cam design.