의료영상진단기기의 기술동향

김경우,김진국,Kim, Gyeong-U,Kim, Jin-Guk 한국정보디스플레이학회 2018 인포메이션 디스플레이 Vol.19 No.4

Protamin 투여로 야기되는 혈역학적 변화에 미치는 Indomethacin 의 영향

김경우,조건현,이홍균,Kim, Gyeong-U,Jo, Geon-Hyeon,Lee, Hong-Gyun 대한흉부심장혈관외과학회 1990 Journal of Chest Surgery (J Chest Surg) Vol.23 No.2

Protamine, a polycationic peptide extracted from fish, has been widely used for the reversal of anticoagulant action of heparin. However it may cause untoward circulatory side effects including hypotension and bradyarrhythmia. Nowadays, histamine and prostacyclin are regarded as one of the causative agents in the underlying mechanism of hemodynamic changes. To certify the possible role of histamine and prostacyclin, we observed simultaneous changes of the hemodynamic status, plasma concentration of thromboxane B, and circulating platelet count before and after intravenous injection of protamine. Experimental dogs, weighing 12-14kg, were divided into 2 groups; group A animals [n=10], were pretreated with indomethacin[2.5mg/kg] and group B animals[n=10] were pretreated with chlorpheniramine[0.5mg/kg] Heparin[3mg/kg] and protamine [3mg/kg] were administered sequentially in both groups. The results were as follows ; 1. The mean systemic arterial pressure was maintained well in groups A, whereas in group B it decreased from 165\ulcorner18mmHg to 138\ulcorner30mmHg[p<0.01] and 151\ulcorner21 mmHg[p<0.05] at 1 minute and 2 minutes after protamine injection. The mean pulmonary arterial pressure was not changed significantly in group A, whereas in group B it increased from 852 mmHg to 11\ulcorner3 mmHg[p<0.05], 11\ulcorner3 mmHg[p<0.05] and 10\ulcorner3 mmHg[p<0.05] at 1 minute, 3 minutes and 5 minutes after protamine injection. 2 The thromboxane B2 was not changed significantly in group A, whereas in group B it increased from 399\ulcorner401 \ulcornerg/ml to 744\ulcorner615 \ulcornerg/ml[p<0.05] and 814\ulcorner1070 \ulcornerg/ml [p<0.0 5] at 1 minute and 3 minutes after protamine injection without concomitant changes of pulmonary vascular resistance and pulmonary capillary wedge pressure. 3. The number of circulating platelet was not changed in group A, whereas in group B it decreased from 207100\ulcorner103600/\ulcornerl to 159700\ulcorner90900/\ulcornerl [p<0.05] at 1 minute after protamine injection, Although thromboxane B2 and platelet count were changed significantly after protamine injection, they did not cause the remarkable hemodynamic changes. Considering the above results, hemodynamic changes may be caused mainly by prostacyclin rather than thromboxane or platelet. Therefore, the pretreatment with cyclooxygenase inhibitor would be beneficial to prevent circulatory adverse effects of protamine for the patients undergoing cardiac surgery.

어선원 복지공간 확보를 위한 어선 선진화 방안 추진 연구

김경우,이희준,Kim, Kyung-Woo,Lee, Hee-Joon 선박안전기술공단 2013 선박안전 Vol.34 No.-

본 연구는 주력업종별 연 근해 어선원의 복지환경에 대한 실태조사 및 국내 외기준의 비교 분석하고 어선원 노동협약 및 일본 어선의 대형화취급방침을 고려하여 어선원 복지 공간 확보할 수 있는 시설기준(안)을 제시하고 시설기준(안) 적용을 통한 총톤수 증가량을 분석하여 "어업허가 및 신고 등에 관한 규칙" 등의 연근해 어업의 종류별 어업허가 상한톤수 개정(안)을 마련하였으며, 개정(안) 적용시 불법 건조를 방지할 수 있는 방안을 검토하여 제시하고자 하였다.

FRP 이음방식에 따른 구조강도 특성에 관한 연구

김경우,강대곤,백명기,박재학,Kim, Kung-Woo,Kang, Dae-Kon,Baek, Myoung-Kee,Park, Jai-Hak 해양환경안전학회 2015 해양환경안전학회지 Vol.21 No.6

본 연구는 해상에서의 안전사고의 경감과 국민의 생명을 보호하기 위한 목적으로 자체 연구를 수행하여 FRP의 수리공법인 Butt Joint, Lap Joint, V-Scarf Joint(12t, 16t, 20t), X-Scarf Joint(12t 16t, 20t)의 인장강도와 굽힘강도를 통해 이음방식에 따른 구조강도 특성을 실험하였다. 이음 방법에 따른 인장강도와 굽힘강도의 시험편을 종합 분석한 결과, 인장강도의 강도와 굽힘강도의 그래프 패턴은 비슷한 양상으로 증가와 감소를 하였으며, 인장강도와 굽힘강도 모두 X-Scarf-Butt Joint-V-Scarf-Lap Joint 순으로 강도가 우수하였다. 인장강도는 강도특성이 가장 우수한 X-Scarf라 하더라도 Basic Material의 57% 수준의 강도를 나타내었고 굽힘강도는 X-Scarf가 Basic Material의 77% 수준의 강도를 나타내었다. 종합적으로 Over-Lay 구분을 포함하여 X-Scarf 12t 이음이 인장강도, 굽힘강도 특성이 우수하였으며 Lap Joint가 가장 좋지 않았다. Scarf 이음시 Taper 길이에 따른 강도의 차이는 V-Scarf 이음은 Taper의 길이가 가장 큰 20t가 인장강도, 굽힘강도 특성이 우수한 반면 X-Scarf 이음은 Taper의 길이가 가장 짧은 12t가 인장강도, 굽힘강도 특성이 우수하여 상반되는 결과를 나타내었다. 선박에는 많은 Stress가 작용하여 시험편만을 가지고 실험한 본 연구와 직접적인 비교는 힘들지만, 재료의 가장 기본 특성을 인장강도와 굽힘강도 시험을 통해 확인할 수 있다. FRP 국부적인 수리 방법인 Butt Joint, Lap Joint, V-Scarf, X-Scarf 4가지의 이음방법에 따른 시험값과 모재 대비 감소되는 비율을 제시하였고 추가적으로 V-Scarf와 X-Scarf의 Taper 길이별 특성을 12t, 16t, 20t로 구분한 결과값을 제시함으로써 수리 현장에서의 위치별 특성에 맞는 수리 방법의 응용이 가능하도록 하였다. We studied about the strength characteristics of the FRP bonding method due to reduce accident on the oceans and protect life for my people. We test tension and bending strength of butt joint, lap joint, V-scarf joint, X-scarf joint. The result of test, it's pattern is similar both tension and bending strength. Tension strength and bending strength was excellent in order to X-scarf-butt joint-V-scarf-lap joint. The tension strength is the best properties X-scarf showed a 57% strength rate of the basic material, and bending strength showed a 77% strength rate of the basic material. Overall, the X-scarf 12t joint has most excellent properties of tension and bending strength. The lap joint has worst properties of tension and bending strength. We have to test having different over-lay of V-scarf and X-scarf joint each 12t, 16t, 20t. V-scarf of 20t over-lay has excellent character of tension and bending strength. But X-scarf of 12t over-lay has excellent character of tension and bending strength. The results are shown to the contrary. The ship is received a lot of stress. it's hard to compare a direction both actual and test. But we can acknowledge material basic characteristic of strength through tension and bending test. We give the four repair method; butt joint, lap joint, V-scarf joint, X-scarf joint and the reduced ratio in comparison with basic material; In addition give the separated data for V-scarf and X-scarf characteristic of 12t, 16t, 20t overlay length. For our study repair man can select good repair method in his work station.

Special Report - 평창동계올림픽 5G 시범서비스 방향

김경우,이승환,임신영,정양재,Kim, Gyeong-U,Lee, Seung-Hwan,Im, Sin-Yeong,Jeong, Yang-Jae 한국정보통신기술협회 2016 TTA저널 Vol.163 No.-

소형어선용 팽창식 구명뗏목 성능기준 개발에 관한 연구

김경우,장철민,박종오,이희준,Kim, Kyung-Woo,Jang, Cheol-Min,Park, Jong-O,Lee, Hee-Joon 해양환경안전학회 2014 해양환경안전학회지 Vol.20 No.5

In order to reduce the risk of deaths from hypothermia at sea, this paper suggests the performance criteria of life rafts for small fishing vessels less than 20 m in length. In our country, the life rafts are not used and have no performance criteria. This research compared the performance criteria of the domestic, foreign, international standards, and the performance comparison between foreign life rafts and the user-friendly valise prototype(2 & 4 persons) which is developed by this study. As a result, it is considered to be appropriate that ISO 9650-1 can be applied to the life rafts for offshore fishing vessels while a milder criteria can be applied to the life rafts for coastal fishing vessels. 본 연구에서는 해상에서의 저체온증 사망위험을 감소시키기 위해, 배의 길이 20미터 미만의 우리나라 소형어선에 비치하기 적합한 구명뗏목의 성능기준을 제안했다. 우리나라에는 소형어선용 구명뗏목이 사용되고 있지 않으며 관련 성능기준도 없다. 국내외 및 국제표준의 성능기준을 비교하고, 외국산 구명뗏목 및 본 연구로 개발된 가방형 시제품(2 4인승)의 성능 평가결과를 분석했다. 그 결과, 근해어선의 구명뗏목에는 ISO 9650-1 기준을 적용하고, 연안어선의 구명뗏목에는 ISO 9650-2보다 기준을 낮추어 적용하는 것이 적절할 것으로 판단된다.

다발성 피하조직 전이를 일으킨 기관지폐암 1례 보고

김경우,이홍균,Kim, Kyung-Woo,Lee, Hong-Kyun 대한흉부심장혈관외과학회 1979 Journal of Chest Surgery (J Chest Surg) Vol.12 No.4

Bronchogenic carcinoma with subcutaneous metastasis is rare, and the incidence ranged from 1.0 to 3.0 %. Therefore metastatic nodules are incidental findings in some instances. The distribution in order of frequency Is as follows: chest wall, scapular region, abdominal wall, course of spine, upper extremities and scalp etc, and mos. of nodules are between 0.5-2.0 cm in diameter. In this report, we present one case of a 54 year old male having bronchogenic carcinoma (squamous cell type) with multiple subcutaneous metastases. The metastatic nodules were located in subcutaneous tissue of right posterior chest wall ($4{\times}5$ cm), frontal scalp area (two; $2{\times}3$ cm, $0.5{\times}0.5$ cm), left scapular region ($1{\times}1$ cm) and left iliac crest ara ($1{\times}11$ cm).

재발성 군날개 환자에서 미세 다공성 신전된 폴리테트라플루오로에틸렌 삽입의 임상효과

김경우,김재찬.Kyoung Woo Kim. MD. Jae Chan Kim. MD. PhD 대한안과학회 2013 대한안과학회지 Vol.54 No.3

Purpose: To investigate the clinical effect of micro-multiporous e-PTFE insertion for severe recurrent pterygium with symblepharon. Methods: The present study included a total of 13 cases of recurrent pterygium associated with symblepharon, motility restriction and diplopia which had undergone micro-multiporous e-PTFE insertion after pterygium excision, 0.02% mitomycin C application, human amniotic membrane transplantation (AMT) and/or conjunctivo-limbal autograft (CLAU) between September 2010 and February 2011. One month after surgery, the inserted e-PTFE was removed. Recurrence of pterygium and symblepharon, motility restriction, diplopia and injection of ocular surface were evaluated for 11.92 ± 1.32 months of mean follow-up period. Results: Pterygial recurrence was not observed in 12 out of 13 eyes, and the 1 eye which recurred showed conjunctival recurrence. No postoperative symblepharon recurrence was observed in any of the 13 eyes. Diplopia and motility restriction disappeared in 11 out of 13 eyes, and were improved in the other 2 eyes. VAS (Visual Analogue Scale) injection scores in the wound site decreased after surgery in all patients. Conclusions: Micro-multiporous e-PTFE insertion combined with mitomycin C application, AMT and CLAU can be a useful surgical method to lower the postoperative recurrence rate and to improve the pterygium-related symptoms in severe recurrent pterygium.

폐실질 및 기관지에 발생한 과오종[3례 보고]

김경우,이홍균,Kim, Gyeong-U,Lee, Hong-Kyun 대한흉부심장혈관외과학회 1981 Journal of Chest Surgery (J Chest Surg) Vol.14 No.4

Pulmonary hamartoma is relatively common among the benign tumors of lung, and is credited to Albrecht who In 1904 described a disorganized arrangement of tissue normally present In an organ. But hamartoma has rare incidence of total pulmonary tumors, and especially endobronchial origin is extremely rare. We have experienced three cases of pulmonary hamartoma Including one bronchial origin. First case was a 27 years old woman who had multiple hamartomas, located all in right middle lobe and middle lobectomy was performed. Second case, a 56 years old woman, had endobronchial hamartoma, l x l .5x l .8cm in size and located at right intermediate bronchus. Right pneumonectomy was Inevitable because of It`s proximal location near the hilum. Third case, a 55 years old man, revealed sclerosing hemangioma microscopically, 4x4x5 cm In size, in right lower lobe and right lower lobectomy was performed. Postoperative course of all of them were uneventful and discharged with good general condition on the ~ 4th to 26th day postoperatively.

마찰접합 된 STK400 Tube의 미세조직과 기계적 특성 평가

김경우,송국현,Kim, Gyeong-Woo,Song, Kuk-Hyun 한국재료학회 2019 한국재료학회지 Vol.29 No.1

We evaluate the properties of friction welded STK400 steel tube in terms of the relationship between microstructures and mechanical properties. Friction welding is conducted at a rotation speed of 1,600 rpm and upset time of 3-7 sec for different thicknesses of STK 400 tubes. To analyse the grain boundary characteristic distributions(GBCDs) in the welded zone, electron backscattering diffraction(EBSD) method is introduced. The results show that a decrease in welding time (3 sec.) creates a notable increase grain refinement so that the average grain size decreases from $15.1{\mu}m$ in the base material to $4.5{\mu}m$ in the welded zone. These refined grains achieve significantly enhanced microhardness and a slightly higher yield and higher tensile strengths than those of the base material. In particular, all the tensile tested specimens experience a fracture aspect at the base material zone but not at the welded zone, which means a soundly welded state for all conditions.