• Journal of Chest Surgery
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• 제19권3호
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• pp.457-463
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• 1986

Truncus Arteriosus is uncommon, accounting for 0.4%-2.8% of all congenital cardiac malformations. Truncus arteriosus has a poor prognosis in early infancy and defined as "a single arterial trunk that leaves the heart by way of a single arterial valve and that gives rise to the coronary, systemic and one or both pulmonary arteries directly." Through antemortem study of patients with truncus arteriosus the development of surgical techniques for palliation and correction was established. Recently we had surgical experience of truncus arteriosus - Collett '||'&'||' Edwards type 2. The main pulmonary artery was originated from truncus at right posterolateral aspect. Truncal valve was tricuspid with good coaptation. Ventricular septal defect was subarterial type of 2.0 cm in diameter. After detachment of the main pulmonary artery from truncus, truncus was repaired directly. Ventricular septal defect was closed with Dacron patch. Extracardiac valved conduit [Carpentier-Edwards: 16mm] was employed for making continuity between right ventricular outflow tract and pulmonary artery. Postoperatively, incomplete right bundle branch block on electrocardiogram was continued. Patient was died due to respiratory failure in postoperative 40 days.s.

• 대한화학회지
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• 제54권4호
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• pp.380-386
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• 2010

황산 용액에서 양극산화(anodization)에 의하여 생성되는 산화피막의 생성과정(growth kinetics)과 이 피막의 전기적 성질을 전기화학적 임피던스 측정법(electrochemical impedance spectroscopy)으로 조사하였다. 산화피막은 $Al_2O_3$로 점-결함 모형(point defect model)에 따라 성장하였으며, n-형 반도체의 전기적 성질을 보였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.356-356
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• 2013

Monolithic 3D-IC는 현대 집적회로에서 interconnect로 인해 발생되는 여러 문제들을 해결하기 위해 새롭게 제시되고 있는 기술적 개념으로 구현 시 하위 소자 및 interconnet들에 영향을 주지 않는 저온공정이 필수적이다. 특히 germanium (Ge)은 낮은 녹는점 및 높은 캐리어 이동도 덕분에 3D-IC 구현 시 상위 소자의 channel 물질에 적합한 것으로 알려져 있다. 최근 이러한 Ge을 결정화하기 위해 solid phase crystallization (SPC), metal induced crystallization (MIC), laser annealing과 같은 결정화 방법들이 보고되고 있다. 현재까지 SPC 방법에 의해 얻어진 poly-Ge의 도핑농도 및 이동도와 같은 전기적 특성에 대한 분석은 수행된 바 있으나 3D-IC 공정에 적용이 가능한 MIC 기술을 통해 얻어진 poly Ge 필름에 대한 전기적 특성분석은 부족한 상황이다. 본 연구는 SPC 뿐만 아니라 MIC 방법을 통해 ${\alpha}$-Ge를 결정화시키고 얻어진 poly-Ge 필름의 전기적 특성을 XRD 및 hall effect measurement를 통해 분석하였다. 특히 일반적으로 Ge 내에서 p-type dopant로 동작을 하는 defect과 n-type dopant인 phosphorus 관계를 고려하여 여러 온도에서 SPC 및 MIC에 의해 얻어진 phosphorus doped poly-Ge 필름들의 전기적 특성을 분석하였다.

• 대한기계학회논문집
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• 제12권6호
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• pp.1320-1326
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• 1988

본 연구에서는 파괴역학적인 해석법과 표면레프리카법을 확장, 적용시켜 피로 -크리프하의 유지시간에 따른 작은 표면균열의 분포상태와 이의 합체, 성장 및 밀도변 화특성을 해석하여 기초적 자료를 얻는다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.131-132
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• 2022

The type and proportion of construction work varies depending on the stage of progress, and the frequency of inspection and defect occurrences are different. If it is determined to be defective after the inspection, a delay may occur, and additional manpower and resources are required. Therefore, it is necessary to prevent these risks by classifying, deriving, and managing key management woks according to the progress. This study aims to contribute to the efficiency of the supervisor's inspection work by identifying the types of construction that should be managed intensively for each construction progress and deriving the time when defects occur frequently in each construction type.

• Journal of Chest Surgery
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• 제13권3호
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• pp.237-242
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• 1980

This is a case report of spontaneous regression of elevated pulmonary vascular resistance after the age of 6 years in a patient with partial endocardial cushion defect. The patient was first evaluated and considered to be highly risky for surgical correction because of obstructive type of pulmonary hypertension and presisting congestive heart failure at the age of 6 years, during which time medical treatment for congestive heart failure and sufferring from respiratory infection were only provided. Finally the patient was reevaluated at the age of 16 years, in January of 1980 when cardiac catheterization was revealed markedly reduced pulmonary vascular resistance and pulmonary hypertension as well. The patient was operated upon with uneventful postoperative recovery. So we report this case with review of the literatures regarding natural history regarding natural history of partial endocardial cushion defect.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.637-642
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• 2011

Rails are subjected to damage from rolling contact fatigue, which leads to defects such as cracks. Rolling contact fatigue damages on the surface of rail such as head check, squats are one of growing problems. Another form of rail surface damage, known as "Ballast imprint" has become apparent. This form of damage is associated with ballast particles becoming trapped between the wheel and the surface of rail. These defects are still one of the key reasons for rail maintenance and replacement. In this study, we have investigated whether the ballast imprint is an initiator of head check type cracks and effect of defect size using Finite element analysis. The FE analysis were used to investigate stresses and strains in subsurface of defects according to variation of defect size. Based on loading cycles obtained from FE analysis, fatigue analysis for each point was carried out.

• 비파괴검사학회지
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• 제6권1호
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• pp.23-30
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• 1986

The optimumultrasonic test conditions for the thin carbon fiber reinforced plastic (CFRP) sheet were determined for the immersed reflector plate method. The effects of the water distance, the surface conditions of the specimen and transducer characteristics were studied. For a reliable test the water distance between the transducer and the front surface of the specimen should be determined when the beam profile of the transducer appears in the bell-shape. The detectability of the defect was improved as the effective beam width of the ultrasonic transducer became narrow. The transducer should be properly chosen considering to the surface condition of the test material as well as the size and type of the defect to be detected. It was possible to detect the flat bottom hole whose diameter is as small as about 500 micrometer.

• 비파괴검사학회지
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• 제23권6호
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• pp.622-634
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• 2003

This paper is concerned with a computational method for recovering a crack shape of steam generator tubes of nuclear plants. Problems on the shape identification are discussed arising in the characterization of a structural defect in a conductor using data of eddy current inspection. A surface defect on the generator tube ran be detected as a probe impedance trajectory by scanning a pancake type coil. First, a mathematical model of the inspection process is derived from the Maxwell's equation. Second, the input and output relation is given by the approximate model by virtue of the hybrid use of the finite element and boundary element method. In that model, the crack shape is characterized by the unknown coefficients of the B-spline function which approximates the crack shape geometry. Finally, a parameter estimation technique is proposed for recovering the crack shape using data from the probe coil. The computational experiments were successfully tested with the laboratory data.

• 한국세라믹학회지
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• 제19권4호
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• pp.300-308
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• 1982

A new perovskite type compound, (Pb1a-χKy□χ-y) (Zr0.33Ti0.67)O3-χ+y/2 was proposed and synthesized by "Wet-Dry Combination Technique". This defect ferroelectric material was characterized by partial substitutions of K+ for Pb+2 in Pb(Zr0.33Ti0.67)O3. This material was mono-phasic perovskite compound at 800℃ for 1hr., but ZrO2 was more or less isolated from the (Pb1a-χKy□χ-y) (Zr0.33Ti0.67)O3-χ+y/2. As a result, snitering temperature, sintered density, curie temperature, and dielectric constant of test pieces decreased and a-axis was nearly constant, while c-axis gradually decreased with the value x in the region of tetragonal phase of PZT. It was also recognized that the defect structure caused by adding K+ was found in both A-site cation and O-site anion vacancies in the defect PZT.