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.

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.

김종수의 삶과 음악 증언

김종수 한국음악문헌학회 2018 음악문헌학 Vol.- No.9

자기구성 퍼지 제어기법에 의한 AM1 로봇의 위치 및 속도 제어

김종수,최석창,이종붕,김치원,한성현 한국공작기계학회 2002 한국공작기계학회 춘계학술대회논문집 Vol.2002 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.

신경회로망을 이용한 직류전동기의 센서리스 속도제어

김종수,강성주 한국정보통신학회 2003 한국정보통신학회논문지 Vol.7 No.8

근래에는 정확성과 신뢰성이 강한 센서리스 속도추정방법으로 전동기를 구동하기 위한 노력이 전개되고 있으며, 본 논문은 외란에 대한 강인성이 뛰어난 신경회로망을 이용하여 직류전동기의 센서리스 속도제어를 실현한 연구 결과이다. 〔6­8〕 신경회로망은 사람의 뇌가 경험을 통해 학습하듯이 주어진 입력에 대해 학습을 통하여 최적의 출력을 발생한다. 학습은 직류전동기의 수식모델을 통해 얻어진 전압$.$전류 및 회전자 속도를 입$.$출력 데이터로 사용하여 역전파 학습 알고리즘〔8〕을 통해 행하여지며, 학습 완료 후 얻은 최적의 연결강도를 이용하여 속도를 추정한다. 신경회로망에 의한 방식은 복잡한 알고리즘을 사용하지 않고도 정확한 속도 추정이 가능하며, 직류전동기의 문제점인 회전자 권선의 열에 의한 전동기의 성능 악화 및 속도 제어의 어려움을 해소하여 운전 조건에 따른 외란 등에도 강인한 제어 특성을 가질 뿐만 아니라 전 속도 영역에서 속도 응답 특성이 우수한 결과를 얻을 수 있었다. DC motor requires a rotor speed sensor for accurate speed control. The speed sensors such as resolvers and encoders are used as a speed detector, but they increase cost and size of the motor and restrict the industrial drive applications. So in these days, many papers have reported in the sensorless operation of DC motor〔3­5〕. This paper presents a new sensorless strategy using neural networks〔6­8〕. Neural network has three layers which are input layer, hidden layer and output layer. The optimal neural network structure was tracked down by trial and error, and it was found that 4­16­1 neural network structure has given suitable results for the instantaneous rotor speed. Also, learning method is very important in neural network. Supervised learning methods〔8〕 are typically used to train the neural network for learning the input/output pattern presented. The back­propagation technique adjusts the neural network weights during training. The rotor speed is gained by weights and four inputs to the neural network. The experimental results were found satisfactory in both the independency on machine parameters and the insensitivity to the load condition.

초고층 주상복합 건물의 구조적 특성

김종수 한국기술사회 2003 技術士 Vol.36 No.4

신경망을 이용한 협력적 추천 시스템의 성능 향상

김종수,도영아,류정우,김명원 한국뇌학회 2001 한국뇌학회지 Vol.1 No.2

개인화 기술은 과다한 정보를 줄이기 위한 여과 기술로서 최근 인터넷 사용자들과 정보 제공자들로부터 관심의 대상이 되고 있다. 그 중 가장 많이 사용되고 있는 개인화 기술은 협력적 추천으로서, 이 방법은 사용자에게 어떤 항목(상품)을 추천해주는 데 있어서 그 사용자의 다른 항목들에 대한 선호도나 추천 항목에 대한 다른 사용자들의 선호도를 이용하여 추천해준다. 협력적 추천 방법 중 보편적으로 많이 사용되는 최근접 이웃 방법은 유사한 사용자들의 행위에 기반하여 항목들을 추천해 준다. 그러나 이 방법은 사용자들간의 단순한 유사도를 계산함으로써 성능이 떨어지는 문제점이 있다. 데이터마이닝 기법을 적용하여 사용자 선호도 데이터로부터 추천 규칙을 생성하여 추천을 해주는 연관규칙 방법 또한 사용자나 항목간의 내용적, 분류적인 공통성 또는 개념에 의한 연관성을 고려하지 못하고, 단지 단순하고 표면적인 연관성만을 고려하는 문제점을 가지고 있다. 본 논문에서는 추천의 정확도를 향상시키기 위한 신경망 추천 모델을 제안한다. 신경망으로는 다층 퍼셉트론을 사용하여 우선 학습변수들과 입력차원의 변화에 따른 신경망에 기반한 협력적 추천의 성능에 대해 조사하고, 순수한 협력적 추천에서의 문제점인 희소성(sparsity)문제를 해결하기 위해 내용기반 추천과 협력적 추천을 병합한 모델을 신경망에서 보인다. 마지막으로 다른 협력적 추천 방법과의 비교를 통하여 본 신경망 추천 방법의 장점과 성능의 우수함을 보인다. Personalization is a filtering technique to reduce information overload and it recently draws attention upon internet users and information providers. The collaborative recommendation is one of the widely used personalization methods. It recommends a user an article based on other users preferences for the target article or the preferences for other articles of the target user. The nearest neighbor method is one of the common collaborative recommendation methods, which recommends articles based on the behavior of the similar users. However, it suffers from poor performance mainly because it fails in properly computing similarity between users. The rule method extracts recommendation rules from the users preference data using data mining technique. It also suffers from simple and superficial association between users or articles without utilizing conceptual level of association such as commonality in contents and category. In this paper we propose neural networks model to improve the accuracy of recommendations. We investigate various aspects of collaborative recommendation based on multi-layer perceptrons by varying parameters and the dimension of input data. We also combine the collaborative recommendation and the content-based recommendation within a neural network model to solve sparsity problem in pure collaborative recommendation. We finally demonstrate through experiments that the neural network based collaborative recommendation outperforms the existing methods.

인터넷 스포츠 마케팅 만족 요인에 대한 재방문 의사 결정 요인 연구

김종수,양재철 圓光大學校 附設 體力科學硏究所 2002 體力科學硏究 Vol.25 No.2

The development of web technology has changed the business to customer relationship as well as business to business relationship. marketing parading has been shifted from traditional mass marketing and target marketing to one to one marketing with emerging of internet sports marketing system which drive traditional companies to change their marketing strategies. Strategics use of web site in digital economy is the core competition for competitive advantages. Study on determinants of web site satisfaction is internet sports marketing system has been done in the filed of communications and information system partially Recently a few researches are done in the marketing filed, traditional ones as well as internet companies realize the important of internet marketing but partially implement their internet sports marketing strategy, which is in the early stage using as a bench marketing tool. The data analysis methods of this study are Frequency Analysis, Independent Group t Inspection, One-way ANOVA(Post Inspection: Scheffe', p<.05), Interrelation Analysis, Multiple Regression Analysis and use the SPSS WIN 10.0 This results from the lack of understanding the characteristics of internet marketing system and theoretical concept of consumer behavior on internet sports marketing. So we need to intergrate theories related internet sports marketing system and to define value exchange relationship between web site and users.

폴리에스터 필름 개발

김종수 한국고분자학회 1986 한국고분자학회 학술대회 연구논문 초록집 Vol.1986 No.4

호흡기 증상을 나타낸 소에서 Pasteurella spp의 분리 및 약제감수성

김종수,허정호,정명호,조명희,김남철,이국천,서종립,손성기 한국임상수의학회 2001 한국임상수의학회지 Vol.18 No.2

The present study was conducted to investigate isolation and antimicrobial drug susceptibility of Pasteurella spp from pneumonic calves and cows (pneumonic lungs) in Gyeongnam south area from January to November 2000. Pasteurella multocida and P haemolytica were isolated 136 (53.8%) and 22(8.7%), respectively, from 158 of 253 pneumonic calves of 1 to 12 months of age and from pneumonic lungs and simultaneous isolation rate of P mutocida and P haemolytica was 4 (1.6%). Seasonal isolation rate of Pasteurella spp in calves and pneumonic lungs varied from 3 to 65.2%, and it was higher in Fall. The majority of biochemical and cultural properties of P multocida and P haemolytica isolated from calves and pneumonic lung were identical to those of the reference strains employed. Pneumonic lesions of the examined lungs were histologically identified as purulent bronchopneumonia and fibrinous pneumonia. All isolates were resistant to penicillin, amikacin, lincomicin, colistin, cloxacilling, sulfonamide, kanamycin, sulfamethoxasoletrimetoprim, and gentamicin(>80%), but some of them were susceptible to amoxicillin, norfloxacin, cephalexin, cefazolin, orbifloxacin, enrofloxacin, and ciprofloxacin(>60%).