Undoped 및 Er-doped ZnGaInS_4 단결정의 성장과 광학적 Energy Gap

최성휴,방태환 조선대학교 기초과학연구소 2000 自然科學硏究 Vol.23 No.1

ZnGaInS_4 and ZnGaInS_4:Er^3+ single crystals crystallized in the rhombohedral (hexagonal) structure, with lattice constants a=3.831A˚, c=46.107A˚for ZnGaInS_4, and a=3.862A˚, c=46.283A˚for ZnGaInS_4:Er^3+. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of these compounds had a direct and indirect band gap, the direct and indirect energy gaps are found to be 3.165 and 3.001 eV for ZnGaInS_4, and 2.956 and 2.752eV for ZnGaInS_4:Ef^3+ at 10 K, respectively. The temperature dependence of the optical energy gap was well represented by the Varshni equation. The values of α, βof the direct and the indirect energy gap were found to be 9.56x10^-4eV/K, 11.6x10-4eV/K and 353K, 455K for the ZnGaInS_4, and the values of α, βof the direct and the indirect energy gap in the ZnGaInS_4:Er^3+ were given by 9.71x10^-4eV/K, 4.93x10^-4eV/K and 266K, 299K.

CdInGaS_4 및 CdInGaS_4 : Co^2+ 단결정의 광학적 특성

최성휴,방태환 조선대학교 기초과학연구소 1998 自然科學硏究 Vol.21 No.1

Undoped and Co-doped CdInGaS_4 single crystals were grown by the CTR(chemical transport reaction) technique using the iodine (8 mg/cc) as transport agent. The grown single crystals have a layered crystal structure that belongs to the space group C_3t'^5(R3m). the optical absorption measured near the fundamental absorption band edge showed that the optical band structure of these compounds has a direct and an indirect band gap. The fundamental absorption band edge of these single crystals shift to a shorter wavelength region by decreasing temperature and the optical absorption band edge region in Co-doped CdInGaS_4 is observed at a longer wavelength region due to cobalt dopant, than that of the optical absorption of undoped CdInGaS_4. The temperature dependence of the optical energy gaps in these compounds satisfy Varshni equation.

Undoped 및 Co-doped ZnIn₂S₄단결정의 광학적 Energy Gap의 온도의존성

최성휴,강대진,방태환 조선대학교 기초과학연구소 2001 自然科學硏究 Vol.24 No.-

ZnIn₂S₄ and ZnIn2S4 : Co^(2+) single crystals crystallized in the rhombohedral(hexagonal) space group C^(5)_(3v)(R3m). with lattice constants a =3.852 Å, c=37.215Å for ZnIn₂S₄ and a=3.823 Å and c=36.975 Å for ZnIn2S4 : Co^(2+). The direct and indirect energy gaps are found to be 2.771 and 2.672 eV for ZnIn₂S₄ and 2.301 and 2.156eV for ZnIn2S4 : Co^(2+) at 300K. The temperature dependence of the optical energy gap was well represented by the Varshni equation. the values of α and β of the direct and the indirect energy gap were found to be 4.504×10^(4)eV/K, 2.407×10^(-4) eV/K and 35K, 14K for the ZnIn₂S₄, and the values of α, β of the direct and the indirect energy gap in the ZnIn₂S₄ : Co^(2+) were given by 3.262×10^(4) eV/K, 4.121×10^(-4)eV/K and 23K, 31K.

Electromyography 기법을 이용한 씨름 덧걸이 기술의 상체 근 동원 비교분석

신성휴,임영태,김태완,박기자,권문석 한국운동역학회 2003 한국운동역학회지 Vol.13 No.1

Shin, S-H · Lim, Y-T · Kim, T-H · Park, K-J and Kwon, M-S. Electromyographical Analysis of Muscle Activities of Upper Trunk for Ssireum Dutguri Technique. Korean Journal of Sport Biomechanics, Vol. 13, no. 1, pp. 95-108. The purposes of this study were to analyze the muscle activities and the characteristics of muscle recruiting patterns of upper trunk for Ssirum dutguri technique using three top-ranked elite Ssirum players. The EMG technique was used to record muscle activities of both right and left sides of latissimus dorsi, biceps brachii, and erector spinae. Six surface electrodes were placed on the surface of the selected muscles and one ground electrode was also attached on the back of neck(C7). One video camera was also used to record the Ssirum motion to define 4 events and 3 phases for further analysis. The raw EMG data were filtered with band pass filter (50-400 Hz) to remove artifacts and then low pass filtered (4 Hz) to find the linear envelope which resemble muscle tension curve. This filtered EMG data were normalized to MVIC for the purpose of comparion between the subjects. The results were indicated that each subject with different physical characteristics showed very different muscle activity patterns. Although Ssirum dutguri is considered as foot technique the player grasped opponent's satba(belt) with both hands when they play. Because of this reason, activities of upper trunk muscles were relatively high. However, direct comparison between upper and lower body muscles was not possible due to the lack of the data in present study. Interestingly, all threes subjects showed that erector spinae muscle activity was comparatively higher than those of latissimus dorsi and biceps brachii. This implies to reinforce back muscle as a routine of training to improve performance or to prevent back injury. implies to reinforce back muscle as a routine of training to improve performance or to prevent back injury.

TINA 기반의 인터넷 멀티미디어 서비스 구조 설계

권태형,이상백,박동선,이경휴 한국정보전략학회 1999 추계공동학술대회 논문집 Vol.- No.01

본 논문에서는 TINA 기반의 인터넷 멀티미디어 서비스 구조를 설계하였다. 설계한 구조는 PSTN을 사용하여 인터넷에서 멀티미디어 서비스를 위한 Qos를 보장할 수 있도록 하였다. 본 논문에서 제시한 구조에서는 TINA 비즈니스 모델을 이용하여 사용자는 손쉽게 다양한 멀티미디어 서비스를 이용할 수 있도록 하고, 서비스 제공자는 서비스 제공이 손쉬우며 망 사업자 측면에서는 서비스 활성화에 따른 망 사용 증가로 인해 망 수요를 증가 시킬 수 있도록 하였다.

Er^3+ 단결정의 광학적 Energy Gap의 온도의존성 : Er^3+ Single Crystals CdGaInS_4 및 CdGaInS_4

최성휴,방태환 조선대학교 기초과학연구소 2000 自然科學硏究 Vol.23 No.1

CdGaInS_4 and CdGaInS_4:Er^3+ single crystals crystallized in the rhombohedral (hexagonal) structure, with lattice constants a=3.913A˚, c=37.245A˚for CdGaInS_4, and a=3.899A˚, c=36.970A˚for CdGaInS_4:Er^3+. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of these compounds had a direct and indirect band gap, the direct and indirect energy gaps are found to be 2.771 and 2.503 eV for CdGaInS_4, and 2.665 and 2.479eV for CdGaInS_4:Ef^3+ at 10 K. The temperature dependence of the optical energy gap was well represented by the Varshni equation. In CdGaInS_4, the values of α, βof the direct and the indirect energy gap were found to be 7.57x10^-4eV/K, 6.53x10-4eV/K and 240K, 197K, and the values of αand βof the direct and the indirect energy gap in the CdGaInS_4:Er^3+ were given by 8.28x10^-4eV/K, 2.08x10^-4eV/K and 425K, 283K, respectively.

골프스윙시 근육협응관계 구명을 위한 EMG 분석

심태용,신성휴,오승일,문정환 한국운동역학회 2004 한국운동역학회지 Vol.14 No.3

T. Y. SHIM, S. H. SHIN, S. I. OH, J. I-. MUN. EMG Analysis for Investigation Muscle-Collaborated Relationship during Golf Swing. Korean Journal of Sport Biomechanics, Vol. 14, No. 3, pp. 177-189, 2004. Kinematic and kinetic analysis using 3D Motion Capture system are common, yet there is little in the literature that discuss the relationship and coactivity between muscles during the golf swing. The purpose of this study was to describe the relationship between the employed 16 muscles during golf swing. We could observe 3 muscle patterns such as 'Line' shape, 'L' shape, and 'Loop' shape for the golf swing activity. The 'Line' shape indicates that two muscles act almost perfectly in phase, and the 'L' shape represents that two muscles act in a reciprocating manner(When one is active, the other is quiescent and vice versa). And the 'Loop' shape indicates that two muscles act sequently(After one is active, the other act). In these results, we knew the muscle patterns during golf swing is similar to the patterns during gait. And we presented it was possible to show the consistence of golf swing through the frequency analysis of muscle patterns. We believe that the results potentially useful for the golf players and coaches to analyze their performance.

CuAl_2S_4 단결정의 성장 및 광흡수 특성

방태환,최성휴 조선대학교 기초과학연구소 1998 自然科學硏究 Vol.21 No.1

CuAl_2S_4 single crystal was grown by the chemical transport reaction method using iodine (6mg/cc) as transport agent. The mixture of copper, aluminium, and sulfur elements with high purity (6N, 99.9999%) was used as the starting material. The colorless transparent single crystal with the shape of plate was grown. The single crystal was crystallized in the cubic structure with the lattice constants, a=9.956A˚. The fundamental absorption edge of the single crystal appeared at the near of 345mm. It was found from the relation between the optical absorption coefficient and the incident photon energy that the single crystal has the direct band structure and the optical energy gap is 4.05eV at 10K.

ZnIn_2S_4 및 ZnIn_2S_4 : Co^2+ 단결정의 광학적 특성

박복남,방태환,최성휴 조선대학교 기초과학연구소 1998 自然科學硏究 Vol.21 No.1

ZnIn_2S_4 and ZnIn_2S_4:CO^2+ single crystals crystallized in the rhombohedral (hexagonal) space group C_3v^5(R3m), with lattice constants a=3.859A˚, c=36.991A˚for ZnIn_2S_4, and a=3.664A˚and c=36.884A˚ for ZnIn_2S_4:Co^2+. The optical absorption measured near the fundamental band edge showed that the optical energy band structure of these compounds had a direct and indirect band gap, the direct and indirect energy gaps are found to be 2.778 and 2.682 eV for ZnIn_2S_4, and 2.658 and 2.601 eV for ZnIn_2S_4:Co^2+ at 293K. The impurity optical absorption peaks due to cobalt are observed in ZnIn_2S_4:Co^2+ single crystal. These impurity optical absorption peaks can be attributed to the electronic transitions between the split energy levels of Co^2+ ions located at T_d symmetry site of ZnIn_2S_4 host lattice.

모 제약회사 근로자들의 직업성 천식 유병률과 약제 분말 노출수준

오성수,최용휴,김은아,이영목,장재길,유장진,박승현,김태균,정수영,김규상,강성규 大韓産業醫學會 2006 대한직업환경의학회지 Vol.18 No.2

목적: 제약회사에서 직업상 천식의 유병 규모를 파악하고 작업공정에 대한 작업환경 측정을 통해 제약회사의 약제 분말에 대한 노출수준을 평가하고자 하였다. 방법: 제약회사에서 약제 분말에 노출되는 근로자를 대상으로 천식을 선별하기 위하여 설문조사 및 진찰, 혈액검사, 폐기능 검사 그리고 피부단자시험을 실시하였고, 각 부서별 공정에 따라서 총분진과 항생제 또는 효소제 분말에 대한 작업환경 측정을 실시하였다. 직업상 천식이 의심되는 근로자에 대하여 기관지과민성에 대한 검사(메타콜린을 이용한 비특이 기관지유발시험)와 약제 분말 기관지유발시험을 실시하여 확진하였다. 결과: 설문조사 및 진찰에서 작업 관련 천식 증상이 있는 근로자는 11명(34.4%)이었고, 약제 분말을 이용한 피부단자시험에서 1+ 이상 반응을 보인 근로자 10명(31.2%)이었다. 비특이 기관지유발시험 결과 8명(25.0%)이 양성(PC20 ≤16 mg/ml)이었다. 약제 분말 기관지유발시험을 통해 직업상 천식으로 확진된 근로자는 5명(15.6%)이었다. 작업환경 측정에서 원료를 충진하거나 투입하는 작업 그리고 정립작업에서 약제 분말에 대한 노출이 많았다. 결론: 제약회사에서 직업상 천식은 주로 제조공정 중 약제 분말에 노출된 근로자에서 발생하여, 증상 및 직업성 천식의 유병률이 높았다. 따라서 원료를 충진 또는 투입하는 작업과 정립작업 등 제조과적에서 약제 분말 노출을 줄이기 위한 세심한 주의가 필요하여, 약제 분말을 취급하는 근로자에 대해서는 천식 증상 조사뿐 아니라 정기적으로 피부단자시험, 비특이 기관지유발시험 등을 실시하여야 할 것이다. Objectives: After the investigation of one worker with occupational asthma, we surveyed the preva- lence of occupational asthma and the exposure level of pharmaceutical dust of 32 workers in a pharmaceutical company. Methods: Thirty-two of the 90 employees participated in the survey which consisted of questionnaire, blood sampling, spirometry and skin prick tests with 8 common allergens as well as 9 antibiotics and 2 enzymes. Various indices of the working environment were also measured. Subjects who had a symptom suggestive of work-related asthma or positive skin prick test were further investigated by PC20 methacholine. Nine subjects who had a PC20 result of 16 mg/ml or less (n=7) or had work-related symptoms and positive skin prick test (n=2) were referred to undergo a specific bronchial provocation test to phar- maceutical dust in an academic allergic disease center. Results: Eleven of 32 workers (34.4%) had a work-related symptom suggestive of occupational asthma. Ten (31.2%) showed positive skin prick test. 8 (25.0%) had a PC20 result of 16 mg/ml or less (indicative of significant bronchial hyperresponsiveness), and 5 (15.6%) had a positive result on the specific bronchial provocation test. Exposure levels of stuffing, input of raw materials and screening process were relatively high. Conclusions: This survey showed that pharmaceutical workers have an increased risk of occupational asthma. Although pharmaceutical factories maintain a relatively good working environment, careful control of respiratory tract exposures, especially during stuffing, input or raw materials and screening process, is important to prevent occupational asthma. Pharmaceutical workers need to undergo regular skin prick and methacholine bronchial provocation tests, as well as asthmatic symptom survey, to ensure the early detection and prevention of occupational asthma.