• Journal of Chest Surgery
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• v.37 no.5
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• pp.410-415
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• 2004

Background: In the operation for coronary artery stenosis, the procedures for mitral regurgitation are restricted to cases of more than moderate mitral regurgitation or for the lesions in leaflets. This is based on the belief that the less than mild regurgitation are a form of reversible change results from ischemia with coronary artery stenosis. We studied the changes and prognostic factors of mitral regurgitation in patients with coronary artery stenosis and mitral regurgitation who underwent coronary artery bypass surgery alone. Material and Method: We reviewed the medical records of 90 patients with coronary artery stenosis and mitral regurgitation who underwent coronary artery bypass surgery alone by a single surgeon from Jan. 1995 to Dec. 2002, We grouped the patients according to the postoperative changes of mitral regurgitation, and then we statistically compared the findings of echocardiogram between preoperative and last follow up. Result: There were 24 cases with progression of mitral regurgitation, 12 cases without changes, 54 cases with improvements of mitral regurgitation in total 90 patients. The bypass to LAD was proven as the significant prognostic factor of mitral regurgitation. The preoperative end diastolic left ventricular volume index were higher in aggravated group with 105.38$\pm$38.89 $m\ell$ compared to 71.75$\pm$28,45 $m\ell$ in improvement group, and 84.00$\pm$11.66 $m\ell$ in no change group. The grade of preoperative mitral regurgitation did not show significant differences among the groups. Conclusion: The mitral regurgitation in patient with coronary artery stenosis can be improved after the coronary artery bypass surgery alone. However, the expectation of improvements based on the degree of preparative mitral regurgitation can not be justified, therefore, the procedures for mitral regurgitation should be aggressively considered even in the cases of mild mitral regurgitation. Also, further study should be performed to identify the exact prognostic factors of mitral regurgitation including the left ventricular volume index, and whether the left anterior descending artery has been bypassed.

• The Optical Journal
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• s.144
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• pp.25-25
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• 2013

뷰웍스(대표 김후식)가 국내 기업으로는 처음으로 무선 평판 엑스레이 디텍터 제품의 미국 식품의약국(FDA) 승인을 획득했다. 엑스레이 디텍터는 투사된 엑스레이 영상을 디지털 정보로 바꿔주는 장치다.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.101-104
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• 2015

A 4-years-old, intact male Golden retriever dog was presented with abdominal distension and dyspnea. Physical examination revealed arrhythmia and cardiac murmur. Generalized cardiomegaly, pleural effusion and ascites were shown on thoracic and abdominal radiographs. Two-dimensional echocardiography revealed abnormal mitral and tricuspid valve motion, mitral and tricuspid regurgitation, left ventricular eccentric hypertrophy and left atrial dilation. Color-flow Doppler imaging revealed turbulent flow extending into the left ventricle during diastole from the mitral valve orifice, and into the left atrium during systole. Spectral Doppler recordings revealed highly increased early diastolic mitral valve inflow and prolonged pressure half-time of mitral inflow. Based on the echocardiographic examination, the diagnosis was made as the mitral valve dysplasia concurrent with mitral valve stenosis and tricuspid valve dysplasia.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.12
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• pp.1073-1079
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• 2014

Aircraft parts are considered as a significant element for the continued airworthiness of the certified aircraft well as a partial component consisting of the new aircraft design. US FAA established the certification system of Parts Manufacturer Approval in 1965, which is contributing to the continued airworthiness of the aircraft in operation and to the expansion of worldwide market of aircraft parts. In this paper, we compared the differences of the certification systems between FAA Parts Manufacturer Approval and EASA European Part Approval, and proposed the rulemaking items to improve Korean Parts Manufacturer Certification System and to contribute to growth of aircraft parts industry.

• The Journal of Aerospace Industry
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• s.68
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• pp.38-63
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• 2006

디지털 하드웨어가 값이 싸다는 것과 그 외형적 크기도 작아지고 있으며 소모 전력도 적다는 경향 때문에 항공에서 디지털 시스템의 사용이 현저하게 증가하게 되었다. 일부에서는 디지털 실용화가 아날로그 기반의 설계를 대체하기까지 하고 있으며 전연 새로운 개념이 도입되고 있는데 이는 모두 디지털 시스템 덕분이다. 대부분의 경우 항공에서 디지털 시스템은 안전에 치명적인 특성을 가지며 해당 소프트웨어의 오류로 항공기의 지속적인 비행과 착륙을 할 수 없는 고장을 유발할 수 있다. 이러한 이유로 항공기에 적용되는 소프트웨어의 인증이 대두되는 것이다. 이 글에서는 향후 우리나라에서도 전개될 소프트웨어의 인증에 대비하여 인증의 기준으로 적용되고 있는 RTCA DO-178B의 내용을 살펴보고 전형적인 항공기 또는 TSOA 인증과정에서의 소프트웨어의 승인 프로세스를 살펴보았다.

• 정보화사회
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• s.17
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• pp.50-57
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• 1989

정보통신 역무제공 승인제는 그동안 승인방법을 둘러싸고 활발한 토론이 전개돼왔다. 허가제로 할것이냐, 아니면 등록제, 신고제로 할것이냐에 대한 의견이 분분했는데 올해는 이에대한 구체적 실행방안이 나올 전망이다. 한편 한국데이타통신은 지난해 12월 3차회선사용 완화 조치에 보조를 맞추고자 특정통신회선서비스 이용약관을 변경했다. 따라서 이번호에서는 현행의 정보통신역무제공 승인업무, 공동사용 특례승인업무 및 변경된 특정통신 회선서비스 이용약관을 게재한다.

• Journal of Korea Ship Safrty Technology Authority
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• s.24
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• pp.90-105
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• 2008

본 연구는 기존에 사용하고 있는 설계도서 작성 및 도면승인을 위한 검증시스템에 대하여 불편한 점들을 수정하는 등 보완 및 개선을 수행하여 선박설계 정보에 대하여 자체적으로 검증할 수 있는 시스템을 개발하고, 이를 활용하여 설계도서 작성이나 도면승인 업무를 수행함에 있어 신속하고 정확할 수 있도록 하기 위함이다.

• Electronics and Telecommunications Trends
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• v.9 no.2
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• pp.67-75
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• 1994

통신사업이 경쟁화되고 통신시장이 개방화 됨에 따라 각종 통신망에 접속되는 전기통신단말기기에 대한 신뢰성, 안전성 등을 확인하는 형식승인의 중요성이 높아지고 있으며, 일부 국가에서는 이러한 형식승인제도를 자국의 시장보호수단으로 활용하고 있는 실정이다. 따라서 우리도 국제동향을 신속히 파악하여 능동적으로 대처해야 할 것이다. 본 고에서는 OECD국가들을 중심으로 형식승인제도의 운영실태, 문제점 등을 분석하고 향후 개선 및 발전방향을 기술하였다.

• Journal of Chest Surgery
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• v.36 no.11
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• pp.820-827
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• 2003

Background: Mitral valve repair rather than replacement for mitral regurgitation (MR) offers a number of well-accepted benefits. However, the surgical results of repair for mitral valve endocarditis remain largely unknown. Material and Method: Fourteen patients who underwent mitral valve repair for MR caused by mitral valve endocarditis from April 1995 through October 2001 were reviewed retrospectively. There were 9 male patients and mean age was 32$\pm$10 years. Four patients had previous embolism and 2 had active infections. The grade of MR were III in 6 patients and IV in 8. Operatively, mitral annuloplasty was performed in 12 patients and various valvuloplasty techniques were applied in all patients. One patient had immediate valve replacement due to residual MR after weaning of cardiopulmonary bypass. Result: There was no early operative death. Early postoperative transthoracic echocardiography revealed no or grade I of MR and no or mild mitral stenosis in 13 patients. After the mean follow-up of 36 months, there was no late death, and no or grade I of MR in 11 patients (84.6%) and no or mild mitral stenosis in 12 patients (92.3%). Reoperation required in one patient (7.1%). The cumulative freedom from recurrent MR and valve-related reoperation at 5 years were 91$\pm$9% and 75$\pm$22%, respectively. Conclusion: This study suggests that mitral valve repair for mitral regurgitation caused by endocarditis offers good early and intermediate survival and functional improvement without reinfection, and it is an attractive alternative to valve replacement in selective patients with bacterial endocariditis.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.598-606
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• 1997

Among 136 patients having undergone mitral valve surgery from September of 1994 through August of 1995 in Sejong Heart Institute, forty four patients(18 males, 26 females) underwent mitral valve reconstruction using prosthetic rings and their clinical results were evaluated. Patients'ages ranged from 5 to 63 years(mean age 38.2 years). Mitral valvular diseases were due to rheumatic origin in 30 patients(68%), degenerative in 13(30%), and congenital in one patient(2%). Mitral regurgitation(MR) was in 33 patients(76%), mitral stenosis 2(5%), and mitral stenoinsufaciency 9 patients(19%). The patients were divided into Carpentier's functional groups : type I, 5 patients(11%) : type I, 24 patients(55%) ; type III, 4 patients (9%) i and mixed(II + III), 11 patients(25%). Average number of anatomic lesions of mitral valve per patient was 3.7. The techniques included prosthetic ring amluloplasty(44 patients, 32 Carpentier ring and 12 Duran ring), leaflet mobilization(24, 55%), chordae shortening(23, 52%), chordae transposition(23, 52%), commissurotomy(16, 35%), leaflet resection(9, 20%), papillary muscle splitting(8, 18%), and chordae reimplantation(1, 2%). Average 3.4 surgical procedures were applied on mitral valve per patient. There were two hospital mortality and one reoperation due to development of MR(grade III) after 2 weeks. During the mean follow up of 12 months, patients improved in terms of functional class of the New York Heart Association, which was mean 3.0 preoperatively and 1.3 postoperatively. Doppler echocardiographic studies showed adequate valve area(2.07$\pm$0.11 cm2 mean $\pm$standard error), improved ventricular contractiliy in 41 patients(93%), ab ence of MR in 23(53%), trace MR in 18(42%), and garde II MR in 2 patients(5%).