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

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.

고정밀 와이어컷 방전기 기술동향

김종수 전력전자학회 2005 전력전자학회지 Vol.10 No.5

고성능 클러스터 구축

김종수,김봉규,백창현 한국천문학회 2003 天文學會報 Vol.28 No.1

Digital Imaging Fiber-Optic Trans-Illumination과 Confocal Laser Scanning Microscope를 이용한 초기 법랑질 우식증 연구

김종수,김지태,김성오 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.1

최근 새로 개발된 DIFOTI(Digital Imaging Fiber-Optic Transillumination) 시스템의 초기 법랑질 우식증 진단 능력을 평가하고 임상 적용의 가능성을 타진해 보고자 본 연구를 시행하였다. 임상 연구는 유치 탈락 시기에 근접한 학령기 아동 23명을 대상으로 DIFOTI 이미지 촬영을 시행하고 자연 탈락된 유치 20개를 수거하여 CLSM 촬영 결과를 바탕으로 민감도(sensitivity)와 특이도(specificity)를 산출하였으며, 실험실 연구에서는 수거된 40개의 유치를 대상으로 Carbopol 인공 우식 용액으로 1,2,4 그리고 8일간 탈회시킨 후 각각 방사선 사진, DI-FOTI 이미지 그리고 CLSM와 비교 분석하여 다음과 같은 결론을 얻었다. 1. 구내에서 촬영한 DIFOTI 이미지의 민감도는 0.61이었고, 특이도는 0.63이었다. 2. 실험실에서 인공 탈회시킨 유치의 협설면 초기 우식증에 대한 DIFOTI 이미지의 민감도는 0.71 였고, 특이도는 0.75였다. The purpose of this study were to evaluate the efficacy of the newly developed Digital Imaging Fiber-Optic Trans-Illumination(DIFOTI) system in detecting carious lesions in in vivo as gold standard with confocal laser scanning microscopy and compared the efficacy of traditional radiography and DIFOTI system in in vitro as gold standard with confocal laser scanning microscopy, too. For the in vivo study, the subject pool consisted of 23 grammar school age patients just prior to entering the mixed dentition phase. Each patient was given a DIFOTI examination of the anterior and posterior teeth. During 6~8 months. the naturally expire primary teeth were collected and the efficacy of DIFOTI system was compared with confocal laser scanning microscopy. For in vitro study, 40 primary teeth were collected and decalcified by Carbopol decalcification solution for 1,2,4 and 8 days. Every experiment period. all teeth were DIFOTI examined and sectioned to take an image of confocal laser scanning microscopy. Sensitivity and specificity were calculated from the result of DIFOTI examine and confocal laser scanning microscopy analysis. The results and as follows: 1. From the in vivo study, the sensitivity of DIFOTI examine was 0.61 and specificity was 0.63. 2. From the in vitro study, the sensitivity of DIFOTI examine was 0.71 and specificity was 0.75.

초고압직류송전(100KV 20MW)

김종수 대한전기학회 1960 전기의 세계 Vol.96 No.8

두경부 편평세포암종에서 인유두종 바이러스와 p53과 Proliferating Cell Nuclear Antigen 발현의 임상적 의의

김종수,김민식,박경호,선동일,박동선,조승호 대한기관식도과학회 2001 大韓氣管食道科學會誌 Vol.7 No.2

The presence of HPV DNA and the expression of p53 protein and proliferating cell nuclear antigen(PCNA) in head and neck squamous cell carcinoma were determined to evaluate the relationship of these factors and their association with their pathologic stages and cervical lymph node metastasis. Among 65 patients the presence of HPV DNA was found in 12 cases(18.5%), p53 was found positive in 32 cases(49.2%) and expression of PCNA was observed in 24 cases(36.9%). The expression of PCNA was more frequent in the HPV positive cancers compared with the HPV negative ones(p =0.0018), and p53 revealed its higher rate of cooccurrence with the expression of PCNA(p =0.008), which might suggest that PCNA expression has a positive relationship with HPV and p53 mutation in head and neck cancer. There might be inverse relationship between HPV and p53 mutation(p =0.063), but 3 cases showed both HPV DNA positivity and p53 expression. HPV was detected at a higher rate in the early pathologic stages than in the advanced stages of cancer, and p53 expression was more frequently found in the advanced stages(p =0.044). These results suggests that HPV and p53 mutation might have different etiologic roles in the development of head and neck cancer, or cases with p53 mutation might have more aggressive behavior. PCNA expression showed no difference between early and late stages of cancer, and between cases with and without cervical lymph node metastasis.

고양이와 정상 정중신경 체성감각 유발전위와 체온변화가 이에 미치는 영향에 관한 연구

김종수,정영섭,왕규창,조병규,최길수 대한신경외과학회 1990 Journal of Korean neurosurgical society Vol.19 No.1

To determine the normal median nerve somatosensory evoked potentials in cat and to evaluate the effect of temperature change, following experiment was done. Median nerve somatosensory evoked potentials(MNSEP) were recoreded in 45 mongrel cats at 38.5℃, the normal temperature range in cats, and in 8 cats of them MNSEP was recorded at 37.5℃, 36.5℃ and 35.5℃ additionally. The results were as follows : 1) Seven peak waves were always recorded and they were named as Ⅰ. Ⅱ. P₁, Ⅲ, N₁, P₂, N₂, and central conduction time(CCT) was thought as Ⅰ -N₁ interpeak latency and it was 5.81±0.53msec. 2) The peak latencies of all waves and CCT were increased gradually as temperature decreased. The latencies of the late waves increased more than those of early waves as temperature decreased except N₂.

給餌와 無給餌에 따른 初生병아리의 體重, 卵黃및 消化器官의 變化에 關한 硏究

金鍾洙 順天大學校 農業科學硏究所 1987 農業科學硏究 Vol.1 No.-

This experiment was conducted to evaluate the changes of body weight, yellow yolk and digestive organs between feeding and nonfeeding treatment in broiler chicks. Twenty chicks were investigated respectively at twelve hours intervals after hatching in the two treatments. Body weight appealed highly significant at the 36hours after hatching between feeding and nonfeeding groups, decreased rapidly at 60hours after hatching in the nonfeeding group. Yellow yolk was decreased remarkably from 60hours after hatching in the nonfeeding group, contrasted with feeding group, however, no uniform significance was shown in two treatments. Ventricles gizzard showed highly significant from 132hours after hatching between two treatments. Duodenums length was highly significant from 36hours after hatching between two groups and increased remarkably from 48hours in the nonfeeding group, 36hours in feeding group, respectively. The length of small intestines and cecum showed highly significant from 72hours after hatching between two treatments. There was no significance in the length of colon and rectum between feeding and nonfeeding groups.