조수석 에어백 인플레이트 선정프로그램

조영기(Yeong-Gi Cho),김창수(Chang-Soo Kim),이세복(Sey-Bok Lee) 한국자동차공학회 2003 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

Inflator is the most important component to design Passenger Side Airbag(PAB). It is not only the weight portion of Inflator is up to 50% of PAB module and geometric characteristic (length and diameter) set the feature of module but also the Inflator output directly related to PAB performance. In general, more and more effort would be needed to tune up PAB module performance and component designs should be modified for this purpose But inflator output<br/> and characteristic themselves set the basis of the module performance. In this paper, it is shown the very first stage of PAB module development including inflator selecting procedure and identify the characteristic between Hybrid type(majority in domestic PAS module design) and Pyro type inflator.

대퇴 골두 충돌 증후군(Cam type)의 진단과 치료를 위한 자기공명 3D 영상 재구성 기법의 유용성

곽영곤(Yeong-Gon Kwak),김종일(Chong-Yeal Kim),조영기(Yeong-Gi Cho) 한국콘텐츠학회 2015 한국콘텐츠학회논문지 Vol.15 No.11

Hip FAI 진단과 수술 계획 시 Hip FAI MRI 검사시 3D 영상을 추가로 활용하여 CT 영상으로 이루어지는 Hip Clock face 영상을 MRI 3D 영상으로 대체할 수 있는지 비교 평가 하였다. Hip 자기공명 영상검사(MRI)와 3D Hip 컴퓨터 단층 촬영(CT)을 동시 시행한 환자 31명 (남: 21명 평균연령: 35세 여: 10명 평균연령: 40.3세)을 대상으로 분석하였으며, 영상평가는 정형외과 전문의 1명과 영상의학과 전문의 1명이 MR과 CT modality에서 Hip joint articular transverse ligament의 6 o’clock을 중심으로 Superior을 12 o’clock, Labrum의 전면을 3 o’clock, 반대쪽을 9 o’clock로 기술하는 Clock face을 재구성 한 후 11 o’clock에서 A. retinacular vessel, B. head neck junction, 12 o’clock A. Epiphyseal line, B. Cam lesion, 1,2,3,4 o’clock의 Cam lesion, Posterior Cam lesion확인 여부를 리커트(Likert scale) 5점 척도로 평가하였다(Independent t-test p〈0.05). 리커드 척도 결과 11 o’clock A. retinacular vessel MR 평균 값 3.69 ± 1.0, CT 평균값 2.8 ± 0.78이며 통계적으로 유의하였다(p〈0.001). B. head neck junction은 두 평가자간 차이가 없었다(p〈0.416). 12 o’clock A. Epiphyseal line MR 평균값 3.54 ± 1.00, CT 평균값 4.5 ± 0.62이었다(p〈0.000). B. Cam lesion은 두 평가자간 차이가 없었다(p〈0.532). 1,2,3,4 o’clock 의 Cam lesion과 Posterior Cam lesion은 통계적으로 유의하지 않았다(p〈0.656, p〈0.658). weighted Kappa 검증 결과 11 o’clock A.retinacular vessel CT K값이 0.663으로 가장 낮은 일치도였으며, 각각의 평가 항목의 일치도 평가 결과 매우 높은 결과로 두 평가자간 높은 신뢰도를 보여주었다. To minimize CT examination for Hip FAI diagnosis and operation plan. also, whether the MRI 3D images can replace Hip Clock face image was evaluated when performing Hip FAI MRI by using additional 3D image. This study analyzed Hip MRI and 3D Hip CT images of 31 patients in this hospital. For the purpose of evaluating the images, one orthopedic surgeon and one radiology specialist reconstructed Clock face, at MR and CT modality, by superior 12 o’clock, labrum front 3 o’clock, and the other side 9 o’clock, centering on Hip joint articular transverse ligament 6 o’clock. Afterwards, by the Likert Scale 5 point scale (independent t-test p<0.005), this study evaluated the check-up of A. retinacular vessel, B. head neck junction at 11 o’clock, A. Epiphyseal line, B. Cam lesion at 12 o’clock, and Cam lesion, Posterior Cam lesion at 1,2,3 and 4 o’clock. As for the verification of reliability among observers, this study verified coincidence by Cohen’s weighted Kappa verification. As a result of Likert scale for the purpose of qualitative evaluation about the image, 11 o’clock A. retinacular vessel MR average was 3.69 ± 1.0 and CT average was 2.8 ± 0.78. B. head neck juncton didn’t have a difference between two observers (p <0.416). 12 o’clock A. Epiphyseal line MR average was 3.54 ± 1.00 and CT average was 4.5 ± 0.62(p〈0.000). B. Cam lesion didn’t have a difference between two observers (p <0.532). 1,2,3,4 Cam lesion and Posterior Cam lesion were not statistically significant (p <0.656, p <0.658). As a result of weighted Kappa verification, 11 o’clock A.retinacular vessel CT K value was 0.663 and the lowest conformity. As a result of coincidence evaluation on respective item, a very high result was drawn, and two observers showed high reliability.

영유아 복부 선자세 촬영시 보조기구의 활용이 영상에 미치는 영향

임호태(Ho Tae Lim),고주영(Ju Yeong Go),강정아(Jung Ah Kang),전인기(In Gi Jeon),김태용(Tae Yong Kim),김금남(Keum Nam Kim),조영기(Yeong Gi Cho) 대한영상의학기술학회 2009 대한영상의학기술학회 논문지 Vol.2009 No.-

Purpose : “Abdomen erect” position is not very suitable for treatment, since it is not easy to hold the baby still as in “supine” position. In response, the necessity of a supplementary apparatus for babies got attention. By using the apparatus, the baby’s body movement and distortion could be prevented, enhancing the quality of the image. Materials and Methods : This study was performed among infants and todcllers(ages ranged from 3 months to 3 years) who didn’t use supplementary apparatus(total 117) from January to March 2008, and who used supplementary apparatus(total 124) from March to August 2008. The mode of examinations was usually done by fixing the children to the supplementary apparatus, but for some children who cannot stand by their own they were examined by supporting their shoulders from the back by their care givers or health care providers. The e-valuation items are the tiltness to one side, the hidening of their abdomen by the care givers’ hands, the adequateness of the collimator, the inclusion of the diaphragm, and the inclusion of both abdomen. Results : At the examination method using a supplementary apparatus produce wider diagnostic fields and 50% more adequate image than that not using a supplementary apparatus. Single fault results improved with 19% and images with more complicated one with two or more faults improved by more than 34% resulting in net increase in the image quality. The suggestive reason of this improvements is less mobility of the patients by fixing the patient firmly to the supplementary apparatus resulting in less repeat radiographing and more valuable images. Conclusion : For radiology, enhancing the quality of the picture takes precedence over technicality and doctor’s competence, which will help to provide the best medical service possible. On the contrary, it appears that the effort to improve the position of babies and children for better picture, has been dwindling. The use of a supplementary apparatus gave us a picture that was more in line with the purpose of the treatment, and the quality of the image improved visibly.

Dosimeter를 이용한 CT 검사실의 공간선량 분포에 대한 비교 분석

정재연(Jae yeon Jeong),김영빈(Yeong bin Kim),구양수(Yang su Ku),이광원(Gwang won Lee),조영기(Yeong gi Cho) 대한CT영상기술학회 2011 대한CT영상기술학회지 Vol.13 No.1

목 적 공간선량은 방사선의 이용과 관리에 중요한 사항이며 더욱이 방사선 관계종사자들은 상대적으로 방사선 구역에 오래 머물기 때문에 각별한 주의가 필요하다. CT검사실 조정실 내ㆍ외부의 공간선량을 측정하여 이에 대한 중요ㆍ위험성 인식 및 작업종사자가 받는 방사선피폭 을 감소시킬 수 있는 방안을 마련하고자 한다. 대상 및 방법 2010년 3월 1일부터 6월 30일까지이며 본관 CT실 조정실 내. 외부의 4개월 동안 발생한 공간선량을 비교분석하였다. 대상 장비로는 16 MDCT(Somatom Sensation16 Siemens, Germany)와 Dual Source CT(Somatom Definition Siemens, Germany)장비를 사용 하였으며, 또한 같은 공간에서의 조정실 실내 구조를 갖춘 상태에서 공간선량을 측정하였다. 측정기로는 Thermo ESM FH40G-L10 2EA를 사용하여 공간선량을 측정 하였으며 차폐기구는 Lead Glass 2EA(TRCT-500-140)를 이용하였다. 결 과 측정 기간동안 조정실 실내의 Max값은 18.3 uSv이었으며 실외의 Max값은 52.8 uSv 이었다. 조정실 실내의 Dose값은 20.22 uSv/week이었고, 실외 Dose 값은 72.64 uSv/week의 공간선량율을 보였다. 공간선량을 줄여 보고자 Lead Glass TRCT-500-140을 사용하였으며 사용전 조정실 실내의 평균 Max값은 4.61 uSv/week이었으며, 사용 후의 조정실 실내의 평균 Max값은 2.09 uSv/week이었다. 사용 전과 후의 2배의 공간선량율 차이를 보였다. 사용 전 조정실 내ㆍ외부의 평균 Dose값은 20.22 uSv/week, 72.64 uSv/week이었으며 사용 후 조정실 내ㆍ외부의 평균 Dose값은 12.8 uSv/week, 32.36 uSv/week의 공간선량율 차이를 보였다. 결 론 공간선량은 식약청 기준치인 0.1 mSv/week 보다 낮은 72.64 uSv/week로 비교적 안전한 것으로 보이지만 방사선방호의 최적화라는 관점에서 볼 때 저선량의 방사선이라도 장기적으로 피폭을 받게 되면 확률적영향이 발생될 수 있으므로 개인별 피폭 선량 데이터를 철저히 관리 분석하여 저감화조치 ALARA와 같은 체계적인 개인별 피폭선량 데이터의 철저한 관리로 개인 피폭관리에 만전을 기울어야 할 것이다. Ⅰ. Objective Spatial dose is a crucial factor in the use and management of radiation, and radiation- related workers should be managed more carefully because they stay in the radiation area relatively longer. Thus, this study purposed to measure spatial dose inside and outside of the control room of the CT Room, to emphasize the importance and risk of radiation exposure, and to make a plan to reduce radiation- related workers’ exposure to radiation. Ⅱ. Subjects and methods This study was conducted from March 1 to June 30, 2010, and made comparative analysis of spatial dose inside and outside the control room of the CT room in the main building for the four months. Machines used in this study were 16 MDCT (Somatom Sensation16 Siemens, Germany) and Dual Source CT (Somatom Definition Siemens, Germany), and spatial dose was measured in the environment where a control room was installed inside the same space. Spatial dose was measured using Thermo ESM FH40G-L10 2EA, and lead glass 1EA (TRCT-500-140) was used as a shielding tool. Ⅲ. Results During the measuring period, the maximum does inside the control room was 18.3 uSv, and that outside the room was 52.8 uSv. The spatial dose rate inside the control room was 20.22 uSv/week, and that outside the room was 72.64 uSv/week. In order to reduce spatial dose, we used lead glass TRCT- 500-140. Then, the mean maximum dose inside the control room decreased from 4.61 uSv/week before the use of the lead glass to 2.09 uSv/week after, showing a decrease by half with the use of the shielding tool. The mean spatial dose rates inside and outside the control room before the use of lead glass were 20.22 uSv/week and 72.64 uSv/week, respectively, and those after the use of lead glass were 12.8 uSv/week and 32.36 uSv/week, respectively, showing significant differences. Ⅳ. Conclusions Spatial dose looks relatively safe as 72.64 uSv/week, which is lower than 0.1 mSv/week, the upper limit required by KFDA, but from the viewpoint of the optimization of radiation protection, even to low-dose radiation, long-term exposure may increase the probability of damage. Therefore, individuals’ exposure should be controlled thoroughly through systematic analysis and management of data on individuals’ exposure dose such as ALARA.

FAI 환자의 30 Pelvic CT MPR 영상의 유용성

김종희(Jong Hee Kim),이득열(Deuk Yeol Lee),이광원(Gwang Won Lee),구양수(Yang Soo Ku),조영기(Yeong Gi Cho) 대한CT영상기술학회 2011 대한CT영상기술학회지 Vol.13 No.2

최근 증가하고 있는 FAI(femoroacetabular impingement syndrome) 영상진단에 3D Pelvic CT가 임상적으로 많이 시도되고 있다. 이에 본 연구는 CT MPR 영상들을 비교, 분석하여 FAI 진단에 있어 유용성을 알아보고자 한다. 대상 및 방법 2009년 7월부터 2010년 3월까지 본원으로 내원한 환자 중 FAI로 진단된 환자(Cam형 or Mixed형) 남자 14명, 여자 6명 총 20명을 대상으로 하였다. 방법은 일반 X-ray Hip joint axiolateral 영상과 3D Pelvic CT의 Oblique axial plane MPR영상과 Radial plane MPR 영상의 alpha angle을 측정하여 비교 분석하였다. 결과 일반 X-ray Hip joint axiolateral 영상과 3D Pelvic CT의 Oblique axial plane MPR 영상, 그리고 Radial plane MPR 영상의 alpha angle을 측정하여 비교, 분석한 결과 평균값이 각각 69.9° 72.8°, 75.4°로 Radial plane MPR 영상의 alpha angle이 75.4°로 가장 높게 측정되었다. 결론 일반 X-ray의 Hip joint axiolateral 영상에서는 정확한 자세와 각도로 촬영하여야만 의미있는 측정치를 얻을 수 있었으며, 3D Pelvic CT의 Oblique axial plane MPR의 alpha angle은 Radial plane MPR 영상보다 평균 2.6° 작게 측정되어 FAI가 저 평가되었다. 따라서 Radial plane MPR 영상이 더욱 유용하므로 FAI의 진단에 효율적이라 사료된다. I. Purpose Three-dimensional pelvic CT is often attempted clinically in the radiological diagnosis of FAI (femoroacetabular impingement syndrome), the incidence of which is increasing recently. Thus, this study purposed to examine the usefulness of CT MPR images in the diagnosis of FAI through comparative analysis of such images. II. Meterial and Methods The subjects of this study were 20 patients (14 males and 6 females) diagnosed with FAI (cam type or mixed type) sampled from patients who had visited the hospital during the period from July 2009 to March 2010. As to the method, we measured and compared the alpha angle in ordinary X-ray hip joint axiolateral images, and in oblique axial plane MPR images and radial plane MPR images of 3D Pelvic CT. III. Result When che alpha angle was measured and compared for ordinary X-ray hip joint axiolateral images, and oblique axial plane MPR images and radial plane MPR images of 3D Pelvic CT, the mean alpha angle was 69.9°, 72.8° and 75.4°, respectively, so it was large&t as 75.4° in radial plane MPR images. IV. Conclusions In ordinary X-ray hip joint axiolateral images, meaningful measurements can be obtained only when the position and angle of imaging are accurated, in addition, the mean alpha angle in oblique axial plane MPR images of 3D Pelvic CT was 2.6° smaller than that in radial plane MPR images, and as a result, FAI was underestimated. Accordingly, radial plane MPR images are more useful and thus should be considered in the diagnosis of FAI.

SiC 입자강화 알루미늄 복합재료 마멸특성

조경목,이희태,김수영,조영기 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.4

In the present study, wear properties, of cast Al-SiC_p composites were characterized. Wear tests were performed as a function of teat conditions including applied load, sliding speed and sliding distance under dry wear condition employing a block-on-roller type wear test machine. Wear mechanism of Al-SiC_p composites was also investigated by the analysis of worn surfaces and wear debris. Results show that wear resistance of Al alloy is improved with reinforcement of SiC_p especially with severer wear conditions such as high applied load and long sliding distance. Weight loss of Al-SiC_p composites almost linearly increases with applied load and sliding distance. There exists a transition point of wear behavior at which a minimum wear rate encountered in terms of the sliding speed. Wear mechanism is abrasive at the low speed and at .the transition speed, and adhesive/abrasive wear at the high speed range. It was found that uniform distribution of SiC_p reinforcement is desirable to improve the wear resistance of Al-SiC_p composites.