Digital Subtraction Angiography (DSA)시 Grid 사용유무에 따른 화상변화에 관한 연구

이성길,김승국,김영근 광주보건대학 1990 論文集 Vol.15 No.-

It has been investigated the variation of the image for using and no using the Grid at the D.S.A(Digital Subtraction Angiography) system. The result of experiment indicated that in the case of no using the Grid, (1) the irradiation dose of patient was reduced and the life of X-ray tube prolonged. (2) the variation of the contrast was not influence of using the Grid.

투시장치의 화질관리 실태 조사

이성길,김영근,김창복 광주보건대학 2004 論文集 Vol.29 No.-

It is important to control resolution for maintenance of good image quality in fluoroscopic unit. This study is to analyze current situation on control of image quality in fluoroscopic unit. Between the sixth and the twenty eighth March 2003, 77 fluoroscopic units in 40 hospitals in Seoul and Kyung-gi area were tested with fluoroscopic phantom(CDRH phantom, Nuclear associates, USA) and image quality test tool including hight contrast resolution patterns and low contrast objects. We exposed radiation in condition of colon study, and then counted the number of patterns on monitor, printed spot film, and printed abdominal film. In the test on monitor, suitable unit within standard number in hight contrast and low contrast test were 68(88%), 49(64%), respectively, and in the test on printed spot film 73(95%), 67(87%), respectively. The cases within standard number in hight contrast and low contrast test on all the two monitor and printed spot film were 44(57%), 65(84%), respectively. Thradiation was exposed from 100 to 120Kvp in fluoroscopy, and spot radiography 80 to 110Kvp mainly. In conclusion, it is necessary that image quality control is done continuously by standard of image quality control suitable for current situation.

펄스폭 변조에 의한 무정전 전원장치에 관한 연구

이성길,박해암 광주보건대학 1989 論文集 Vol.14 No.-

Recently Uninterruptible Power Supply (UPS) Systems are widely used in a variety of fields a s highily reliable power sources. This paper presents the operation and performance of an UPS using sinusoidal Pulse Width Modulation <PWM> techniques. By using the sinusoidal PWM method for UPS systems, the property of harmonics, efficiency and distortion can be improved. Experimental results showed that sinusoidal PWM techniques have good features for UPS system.

네트멜론의 착과절위 및 착과수가 네트발현, 품질 및 과중에 미치는 영향

이성길,이우승 慶北大學校農業科學技術硏究所 1996 慶北大農學誌 Vol.14 No.-

네트멜론에 있어서, 株當 葉數를 22枚로 제한하여 8, 10, 12, 14절의 1과착과와 8-9, 10-11, 12-13, 14-15절의 l2과 착과구를 설치하고 각각 네트 發現, 品質 및 收量에 미치는 影響이 어떠한지 알고자 '슈퍼VIP' 멜론을 이용하여 비닐하우스 내에서 春作栽培로 시험하여 다음과 같은 結果를 얻었다. 1) 株當 1果 着果는 着果節位 관계없이 네트발현이 양호하였으며, 着果節位가 높을수록 果 重, 果長, 果徑, 果肉두께가 증가되었고, 糖度와 貯藏性은 떨어졌다. 2) 株當 2果 着果는 着果節位가 높을수록 네트 發現이 우수하였고, 糖度, 果重, 果長, 果徑, 果肉두께가 증가하였으나, 貯藏性은 差異를 보이지 않았다. 3) 네트발현, 당도 저장성등 商品性은 株當 1果 着果가 2着 着果 보다 뛰어났으며, 12節에 서 1果 着果한 것이 가장 우수했다. 4) 收量性은 株當 2果 着果가 1果 着果보다 增加하였다. This study was carried out to determine the effect of fruit-set position and number of fruit set per plant on yield and quality including netting in "Super VIP" melon cultivated in spring season. 1) In training system of one fruit per plant, index of netting was acceptable, regardless of the node position of fruit-set. The higher node order of fruit set was, the heavier, longer, bigger in diameter the fruit set was, and the thicker the flesh was. However, soluble suger content and storability was decreased with increased node order. 2) In training system of two fruit per plant, the higher the fruit-set position in node order was, the better the netting index, fruit quality including fruit weight, length, diameter, and thickness of flesh were, but there was no difference in storability. 3) Fruits produced by one-fruit-per-plant training were superior to those produced by two-fruit-per-plant training in maker quality including netting, sugar content, storability. The fruit set on 12th node in one-fruit-plant training were the best in market quality. 4) Yield was increased by two-fruit-per-plant training.

X-선관 지지장치의 형태에 따른 광조사야와 X-선 조사야 차이가 영상의 왜곡에 미치는 영향에 관한 연구

이성길,김영근 광주보건대학 1993 論文集 Vol.18 No.-

The centering error and the difference of X-ray and light field are investigated to the effect of image distortion with X-ray equipment at the hospitals and clinics in Kwang ju. The conclusion is that: 1. The centering error of standing type is investigated more highly than the ceiling type. (p<0.05) 2. The error of centering beam is induced the distortion of image in the skull lateral projection. 3. The regular calibration in X-lay equipment is absolutely necessary for image quality control.

Cassette-증감지계 사용실태에 관한 연구

이성길,김영근 광주보건대학 1994 論文集 Vol.19 No.-

The intensifying screen speed and contact test are investigated with cassette-intensifying screen using the hospital and clinics in Kwangju. The results are as follows; 1. The using intensifying screen speed are extremely different each other. 2. The using intensifying screen are most H.S.(91%) 3. The most of using intensifying screen are not clear in period of using (H.S:54%,M.S:62%) 4. The film-screen contact functions are inferior as increase in size.

인버터식 X선장치의 관전압 맥동율 개선에 관한 연구

이성길(Seong-Gil Lee),임홍우(Hong-Woo Llm),조금배(Geum-Bae Cho),정수복(Soo-Bok Chung),백형래(Hyung-Lae Baek) 전력전자학회 1999 전력전자학술대회 논문집 Vol.1999 No.7

In order to radiate X -ray, the low ripple stabilized high voltage DC over the range of 40KV to 150KV is directly inflicted to X -ray tube. The energy characteristics of the radiated X -ray depend on the pulsating waveforms of the DC voltage supplied X -ray tube In general, the low ripple voltage waveforms with fast rising times are required to increase with the dosage per unit I1me lest the exposure I1me should be longer in orde that the motion artifacts of an object may be eliminated in actual The conventional types of X -ray generators were bulky in physical size and heavy in weight, and the control accuracies of the output voltages were not always satisfactory. The high frequency switching inverter and converter technology on power conversion and control systems have been greatly closed up introducing new power semiconductor devices. To decreasing the volume and the weight of high voltage transformer, and to stabilize ripple, a high frequency PWM inverter is connected between DC source and high voltage transformer. This paper describes the output characteristics according to stabilize ripple of X -ray tube voltage and compared the reproducibility, direcibility and doesage.

LC 공진형 PWM 인버터를 이용한 X선 발생장치의 특성에 관한 연구

이성길,박수강,임홍우,조금배,백형래,임양수 조선대학교 에너지.자원신기술연구소 2002 에너지·자원신기술연구소 논문지 Vol.24 No.1

The conventional types of X-ray generators were bulky in physical size and heavy in weight, and the control accuracies of the output voltages were not always satisfactory. The high frequency switching inverter and converter technology on power conversion and control systems have been greatly closed up introducing power semiconductor devices. In this paper, the newly developed converter to take the balance of the output voltage versus the ground are also presented in detail to decreasing the volume and the weight of high voltage transformer and to stabilize ripple. This converter consists of the two independent L-C series resonant circuits using the two capacitances and the two primary windings of high voltage transformer.

Inverter식 X선발생장치의 특성에 관한 연구

이성길,김영근 광주보건대학 1998 論文集 Vol.23 No.-

Out Put Characteristic has been Investigated for Single, Three Phase and Inverter Type X-ray Generators. The results was following ; 1. The percent ripple of tube-voltage wave form appeared of low to 89. 8~96.6(%) in single phase, 7.3~10.5(%) in three phase generators and 3.5~4.7(%) in inverter type X-ray generators. 2. Rectification type are according to single phase, three phase and inverter type X-ray generators and out put efficients were different from 1 : 1.47 : 1.94. 3. HVL for measuring of X-ray quality increased orderly for single phase, three phase and inverter type X-ray generators. 4. Reproducibility of X-ray out put has done a very good in conversion factor of less than 0.05 for all equipments. 5. Linearity of X-ray out put appear to short exposure about inverter type generators for safety.

放射線士의 勤務條件에 關한 硏究 : 光州 全南地域 放射線士 報酬를 中心으로

이성길,김영근 광주보건대학 1990 論文集 Vol.15 No.-

This study for the improvement of the working conditions of Radiological Technologicts is based on a qauestionaire reciered from 118 Radiological Technologists who are employed in medical institutions in the Kwangju and Chun-nam areas It was conducted between November 1989 March 1990. The conclusion of this study is as follows. 1. The average daily working time is almost 10 hours. (in 96.1 % of General Hospitals, 100% of Hospitals, 90.4% of Clinics) 2. Concerning holidays 92.3% of General Hospitals have 1 holiday(Rest Way) per week, 50.0% of Hospitals have 1 holidays(Rest Way) per week, 42.8% of Clinics have 1 holidays(Rest Way) per week. However 47.6% of Clinics have 1 holiday(Rest Way) every 2 week. 3. Their average duty intervals was almost within one and two per week. (in 30.8% of General Hospitals, 83.3% of Hospitals, 52.4% of Clinics) 4. Their monthly salary is higher in Hospitals and Clinics then in General Hospitals. 5. Their yearly bonus rate is General Hospitals 600∼70% (67.2%), Hospitals 400∼500%(41.6%), Clinics 100∼200%(47.5%). 6. Danger allowance is paid with the monthly salary in 80.8% of General Hospitals 25.0% of Hospitals. However in 95.2% of Clinics it is not paid entirely. 7. Their inital salary is about 300,000Won. 8. Their satisfaction of monthly salary is almost non satisfactin. 9. Their salary is raised regulary every year (in 46.1% of G. H. 50.0% of Hospitals), but it is irregulary in 71.4% of clinics. 10. Promotion system is managed in 92.3% of the G. H, in 58.3% of Hospitals. 11. Retirement allowance is assured in 98.1% of the G. H. in 66.7% of Hospitals, and in 28.6% of Clinics.