• Journal of Chest Surgery
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• 제12권3호
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• pp.207-214
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• 1979

This 3-year-old girl was observed frequent exertional dyspnea and cyanosis at crying since birth. She was not premature baby and delivered at full term normally. On physical examination, she was underdeveloped-body weight 13.5 kg, height 99 cm.- and cyanotic. There was severe clubbing on fingers. There was grade II/VI ejection systolic murmur on left lateral border of the sternum. The preoperative examinations [EKG, echocardiogram, cardiac catheterization and biventriculogram] showed that complicated T.G.A. combined vena cava[S.D.D.]. Preoperatively, we decided the corrective surgery of Rastelli operation using a. pulmonary valved conduit. The operation was performed under total circulatory arrest using deep profound hypothermia combining with extracorporeal circulation. On operation, the anatomy of the heart showed that, 1. The subaortic conus was seen and subaortic muscles were hypertrophied. 2. The VSD[type II], behind the subaortic conus-about 1 cm. in diameter, was visible only through LV cavity and, 3. The pulmonary valve ring was hypoplastic and pulmonary valvular stenosis was seen also. The subpulmonic area [LV outflow tract] was obstructed with hypertrophied muscle and mitral valve. 4. Left superior vena cava was drained to RA via coronary sinus. 5. LAD coronary artery was originated from right coronary artery and ran anterior to the pulmonary artery. According to above anatomy, we performed the VSD closure with Teflon patch, and Mustard operation combined with LV-to-pulmonary artery bypass graft using the valve contained [Hancock 16 mm] conduit. Postoperatively, adequate blood pressure could be maintained under the state of using inotropic agent [epinephrine]. On the second postoperative day, the patient died of cardiac arrest due to low cardiac output syndrome, acute renal failure and pulmonary edema.

• 한국환경복원기술학회지
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• 제22권3호
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• pp.1-14
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• 2019

With a view to developing a database of death years of Korean firs (Abies koreana) at Yeongsil in Mt. Halla and investigating their abrupt inter-annual growth reduction tree-ring analysis was employed. To this end, 10 living trees (YSL) were selected to establish a master chronology and 20 dead trees were used to date their dead years. To investigate the difference in death years by death types, 10 trees, which remained standing (YSSD) out of the 20 dead trees were selected. The rest 10 dead trees were already fallen (YSFD). Two increment cores per tree at breast height were extracted in contour direction using an increment borer. A 106-year master chronology (1911-2016) was successfully established from the 10 YSLs. Through cross-dating between individual YSSD time series and the master chronology, it was verified that 1 YSSD was dead in summer 1978, 1 YSSD between autumn 1999 and spring 2000, 2 YSSDs in summer 2007, 1 YSSD in summer 2010, 1 YSSD in summer 2012, and 1 YSSD in summer 2013. The youngest tree rings of 2 YSSDs having no bark were in 1977 and 2002. For the YSFDs, it was verified that 1 YSFD was dead between autumn 1997 and spring 1998, 1 YSFD between autumn 2001 and spring 2002, 2 YSFDs between autumn 2009 and spring 2010, 1 YSFD in summer 2010, and 2 YSFDs between autumn 2012 and spring 2013, while the youngest tree rings of 2 YSFDs having no bark were in 1989 and 2004. To note, the death years of two trees, one from each death type (YSSD and YSFD), could not be verified due to poor cross-dating with the master chronology. The inter-annual growth reductions of YSSD and YSFD occurred more frequently and intensively than YSL. Typically, the YSFD showed the most frequent and intensive inter-annual growth reduction. On comparing the inter-annual growth reductions with the corresponding records of typhoons however we could not find any reliable relationship. Finally, from prior reports and results of the current study it can be concluded that the death and abrupt growth reduction of korean fir at Yeongsil in Mt. Halla are not caused by only a certain environmental factor but various factors.

• 한국전산구조공학회논문집
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• 제33권6호
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• pp.391-399
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• 2020

본 연구는 유한요소 해석모델을 이용해 아치 형상을 갖는 석션 상판의 거동을 분석하였다. 평판형 및 아치형 상판의 기본적인 구조성능에 대해 비교함으로써 아치형 상판의 이점을 설명하였다. 또한 아치형 상판의 기하 및 보강재 배치 변화에 따른 거동 변화를 비교하여 각 인자가 상판의 응력 및 변형에 미치는 영향을 조사하였다. 추가로 아치형 상판 가장자리의 경계조건 영향을 수치적으로 분석함으로써, 아치형 상판의 보강재 배치와 가물막이 벽체와의 상호거동 영향을 규명하고 이를 통해 보강형 아치형 상판의 구조설계의 기본 개념을 도출하였다. 평판형 상판과 달리 환형 보강재가 아치형 상판의 구조 거동을 확연히 개선시킬 수 있음을 확인하였으며, 방사 보강재의 역할은 상판 가장자리의 구속상태에 의존적이었다.

• Journal of Preventive Medicine and Public Health
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• 제6권1호
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• pp.81-85
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• 1973

One hundred and thirty one health articles (as 'original articles') reported in medical journals published in Korea during the period from Jan. to Dec. 1971. were selected as the study materials for tile purpose of resumption and criticism. Of a total of 131 articles, thirty-nine were not required the statistical application for the data processing and drawing their conclusions and ninty-two, 70.2%, were needed to apply. The 92 articles were divided into three groups by the types of study: 54 for experimental study, 30 for clinical case analytic study and 8 for field study. Each report was resumed and criticised under the statistical aspects in terms of data processing and the validity of the conclusions. The results of resumption of the 92 articles needed statistical application are summarized as follow; 1. Of the 54 articles of experimental studies resumed, thirty-one articles, 57.4%, were considered acceptable. Among the 38 articles classified as clnical case analytic and field studies, only 28.9 per cent were considered acceptable. In total 45.7 per cent or less than half were considered acceptable. 2. Types of errors encountered are as shown in Table 3. 3. The most frequently encountered error was that the conclusions were drawn without having made any statistical test. This type of error was found in 14 out of 35 errors presented in experimental studies, 11 of 35 in clinical case analytic studies and 5 of 9 in field studies and 30 out of 97, 38.2%, in total.

• Journal of Welding and Joining
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• 제30권6호
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• pp.98-105
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• 2012

The focus of this investigation is to evaluate the effect of joining parameter on the microstructure and mechanical properties of welds produced by friction stir lap welding. The dissimilar Al alloys, KS5J32 and AA6K31, were joined by friction stir lap welding technique under several welding conditions, and KS5J32 alloy was placed on the top of AA6K31 alloy. The tool rotation speeds were 1000, 1250, and 1500rpm, and the welding speeds were 100, 300, 500, 700mm/min, respectively. The results showed that two shapes of nugget, such as onion ring and irregular vortex type, were observed with various revolutionary pitch. In all welding conditions, fracture occurred at the soften region of bottom sheet(AA6K31) and the strengths were 64~78% of those of base metal. Fractured positions were classified into three types : HAZ, triple point, void depending on the revolutionary pitch. The actual thickness of specimen at the fractured location was decreased with decreasing heat input. A linear relationship exists between the effective thickness of fractured position and peak load.

• Journal of Photoscience
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• 제10권1호
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• pp.9-20
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• 2003

Recent studies on the photoreactivity of l,4-unsaturated systems have changed some ideas that were firmly established in this area of research for many years. Thus, we have described the first examples of 2-aza-di-$\pi$-methane (2-ADPM) rearrangements promoted by triplet-sensitization and by single electron transfer (SET) using electron-acceptor sensitizers. These reactions afford N-vinylaziridine and cyclopropylimine photoproducts in the first examples of di-$\pi$-methane processes that yield three-membered ring heterocycles. l-Aza-1,4-dienes also undergo SET-promoted l-aza-di-$\pi$-methane (l-ADPM) rearrangements via radical-cation intermediates using electron acceptor sensitizers. In some cases, alternative cyclizations yielding different carbocycles and heterocycles have been observed. The l-ADPM and di-$\pi$-methane (DPM) reactions also occur via radical-anion intermediates on irradiation using electron donor sensitizers. On the other hand, the photoreactivity reported for $\beta$,${\gamma}$-unsaturated aldehydes for many years was decarbonylation to the corresponding alkenes. However, our studies demonstrate that these compounds undergo the oxa-di-$\pi$-methane (ODPM) rearrangement with high chemical and quantum efficiency. A comparison of the photochemical reactivity of $\beta$,${\gamma}$-unsaturated aldehydes and corresponding methyl ketones has shown that the ketones do not undergo the ODPM rearrangement while the corresponding aldehydes are reactive by this pathway. Monosubstituted $\beta$,${\gamma}$-unsaturated aldehydes at C-2 undergo the ODPM rearrangement yielding the corresponding cyclopropane carbaldehydes diastereoselectively. Finally, we have described the first examples of reactions, similar to the well know Norrish Type I process, which take place in the triplet excited state of $\beta$,${\gamma}$-unsaturated carbonyl compounds by excitation of the C-C double bond instead of the carbonyl group.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.247.1-247.1
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• 2014

The capacitive coupled plasma is used widely in the semiconductor industries. Especially, the uniformity of the industrial plasma is heavily related with defect ratio of devices. Therefore, the industries need the capacitive coupled plasma source which can generate the uniform plasma and control the plasma's uniformity. To achieving the uniformity of the large area plasma, we designed multi-powered electrodes. We controlled the uniformity by controlling the power of each electrode. After this work, we started to research another concept of the plasma device. We make the plasma chamber that has multi-ground electrodes imaginary (CST microwave studio) and simulate the electric field. The shape of the multi-ground electrodes is ring type, and it is same as the shape of the multi-power electrodes that we researched before. The diameter of the side electrode's edge is 300mm. We assumed that the plasma uniformity is related with the impedance of ground electrodes. Therefore we simulated the imaginary chamber in three cases. First, we connected L (inductor) and C (capacitor) at the center of multi-ground electrodes. Second, we changed electric conductivity of multi-ground electrode. Third, we changed the insulator's thickness between the center ground electrode and the side ground electrode. The driving frequency is 2, 13.56 and 100 MHz. We switched our multi-powered electrode system to multi-ground electrode system. After switching, we measured the plasma uniformity after installing a variable vacuum capacitor at the ground line. We investigate the effect of ground electrodes' impedance to plasma uniformity.

• 대한전자공학회논문지
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• 제27권11호
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• pp.9-19
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• 1990

원통형 및 환형 유전체공진기의 복소유전율과 투자율을 측정하기 위한 이론적인 해석과 측정방법을 제시하였다. 두 개의 평면도체 사이에 유전체공진기를 놓고 공진주파수와 무부하 Q, 그리고 치수를 측정하면 복소유전율과 투자율을 구할 수 있으며 이 방법을 고차모우드에 대하여 반복적으로 행하면 더 넓은 주파수 범위에서 측정이 가능하다. 이 때 각각의 공진모우드는 유전체공진기의 방위각과 축방향에 대한 전계 세기의 변화를 측정함으로써 결정할 수 있다. 그리고 여러가지 오차의 요인들을 고려한 측정오차의 해석으로부터 $TE_{0np}$ 또는 quasi-TE 모우드를 측정에 이용할 경우 복소유전율의 실수부분은 $0.5{\%}$, 허수부분은 $4{\%}$ 이내의 측정오차를 가짐이 밝혀졌다.

• 임산에너지
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• 제21권2호
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• pp.43-50
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• 2002

위스키 숙성용 목통으로서 한국산 참나무속 목재의 이용 가능성을 검토하기 위하여 도관직경, 방사조직 밀도, 방사조직 높이, 타일로시스의 존재 유ㆍ무 등 해부학적 특성과 알콜 침지 중의 밀도, 색농도 변화 및 흡수량을 조사하였다. 본 실험에 사용된 참나무속 목재는 모두 환공재였고, 단열방사조직과 광방사조직으로 구성된 복합방사조직을 가지고 있었으며, 방사유세포는 대부분이 평복세포였다. 타일로시스는 루부라참나무를 제외한 공시재 모두에서 존재하였다. 목재 밀도는 알콜 침적 후 많이 감소하였다. 알콜 색 농도는 떡갈나무와갈참나무가 다른 수종보다 더 짙은 황갈색을 나타냈다. 홉수량은 변재가 심재보다 높았고, 특히 red oak가 white oak보다 더 크게 나타났다. 결론적으로 국산 참나무속 수종은 위스키숙성용 목통으로 사용될 수 있을 것으로 판단되었다.

• Composites Research
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• 제29권4호
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• pp.216-222
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• 2016

폴리디싸이클로팬타디엔 (p-DCPD) 수지를 경화하기 위해 개환반응이 사용된다. 이 반응은 텅스텐계 촉매를 이용한 반응이기 때문에 질소 조건에서 반응이 진행되어야 한다. 왜냐하면, 텅스텐계 수지는 촉매독 현상이 발생될 수 있기 때문에 대기조건에서는 사용이 어려운 것으로 알려져 있다. 이러한 문제를 개선하기 위해 본 연구에서는 대기 조건에서 텅스턴 (W)을 촉매로한 p-DCPD 대해 프레스 성형법을 이용하여 수지를 경화시켰다. 프레스 성형을 통해 p-DCPD (W) 수지를 경화시킬 경우 기계적 강도가 향상되는 결과를 얻었으며, 이는 DCPD 성형 단계에서 발생되는 기체를 압으로 눌러 미세 기공의 발생을 줄였기 때문이다. 촉매 독 현상이 발생되는 것은 반응시간이 길 때에 발생되지만, 짧은 성형을 시도하는 프레스 성형에서는 촉매 자체로 인한 물성 저하가 발생되지 않았다. 궁극적으로 p-DCPD 성형을 위해 대기 조건에서 성형이 가능하였으며, 경화 시간, 압력 변수를 조절할 경우 기계적 물성이 향상을 확인하였다.