• Nuclear Engineering and Technology
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• 제40권7호
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• pp.607-614
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• 2008

Since pipes with wall-thinning defects can collapse at fluid pressure that are lower than expected, the collapse moment of wall-thinned pipes should be determined accurately for the safety of nuclear power plants. Wall-thinning defects, which are mostly found in pipe bends and elbows, are mainly caused by flow-accelerated corrosion. This lowers the failure pressure, load-carrying capacity, deformation ability, and fatigue resistance of pipe bends and elbows. This paper offers a support vector regression (SVR) model further enhanced with a fuzzy algorithm for calculation of the collapse moment and for evaluating the integrity of wall-thinned piping systems. The fuzzy support vector regression (FSVR) model is applied to numerical data obtained from finite element analyses of piping systems with wall-thinning defects. In this paper, three FSVR models are developed, respectively, for three data sets divided into extrados, intrados, and crown defects corresponding to three different defect locations. It is known that FSVR models are sufficiently accurate for an integrity evaluation of piping systems from laser or ultrasonic measurements of wall-thinning defects.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2678-2685
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• 2020

The pipe bends and elbows in nuclear power plants (NPPs) are vulnerable to degradation mechanisms and can cause wall-thinning defects. As it is difficult to detect both the defects generated inside the wall-thinned pipes and the preliminary signs, the wall-thinning defects should be accurately estimated to maintain the integrity of NPPs. This paper proposes a deep fuzzy neural network (DFNN) method and estimates the collapse moment of wall-thinned pipe bends and elbows. The proposed model has a simplified structure in which the fuzzy neural network module is repeatedly connected, and it is optimized using the least squares method and genetic algorithm. Numerical data obtained through simulations on the pipe bends and elbows with extrados, intrados, and crown defects were applied to the DFNN model to estimate the collapse moment. The acquired databases were divided into training, optimization, and test datasets and used to train and verify the estimation model. Consequently, the relative root mean square (RMS) errors of the estimated collapse moment at all the defect locations were within 0.25% for the test data. Such a low RMS error indicates that the DFNN model is accurate in estimating the collapse moment for wall-thinned pipe bends and elbows.

• 한국임상수의학회지
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• 제25권5호
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• pp.420-423
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• 2008

Ventricular septal defects (VSDs) is an opening in the ventricular septum that allows blood to flow between the ventricles. Most ventricular septal defects are located in the upper ventricular septum and can be identified by auscultation. In this report, 2 dogs with heart murmur were diagnosed as VSD using radiography and echocardiography. In radiographs, bulging sign of the main pulmonary artery or the enlargement of the left ventricle was observed. The color Doppler examination showed the left-to-right shunting of blood via interventricular septal defect.

• Archives of Plastic Surgery
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• 제48권3호
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• pp.254-260
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• 2021

Background Myelomeningocele is a frequently seen condition at tertiary care hospitals. Its treatment involves a variety of plastic reconstructive techniques. Herein, we present a series of myelomeningocele patients treated using keystone flaps. Methods We gathered information regarding soft tissue reconstruction and the use of bilateral keystone flaps to treat myelomeningocele patients. We obtained data from clinical records and recorded the demographic characteristics of mothers and children with the condition. The size, level of defect, and complications detected during the follow-up were analyzed. Results A series of seven patients who underwent bilateral keystone flaps for myelomeningocele closure was analyzed. There were no cases of midline or major dehiscence, flap loss, necrosis, surgical site infections, or cerebrospinal fluid leakage. No revision procedures were performed. Minor complications included one case with minimal seroma and three cases with areas of peripheral dehiscence that healed easily using conventional measures. Conclusions The use of keystone flaps is an adequate option for closure of dorsal midline soft tissue defects related to myelomeningocele. This technique offers predictable results with an acceptable spectrum of complications. Robust blood flow can be predicted based upon anatomical knowledge.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1891-1894
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• 1999

We can classify the scratches after CMP process into micro-scratch and macro-scratches according to the scratch size, scratch intensity and defect map, etc. The micro-scratches on wafer after CMP process are discussed in this paper. From many causes, major factor that influences the formation of micro-scratch is known as particle size distribution of slurry.(1) It is indefinite what size or type of particle can cause micro-scratch on wafer surface, but there is possibility caused by large particle over 1um. The best way for controlling these large particle to inflow is to use the slurry filter on POU(Point of user). But the slurry filter(especially, depth-type filter) has sometimes the problem which makes more sever micro-scratches on wafer surface after CMP. We studied that depth-type slurry filter has what kind of week-points and the number of scratch could be reduced by lowering slurry flow rate and by using high spray bar which sprays DIW on polishing pad with high pressure.

• Journal of Acupuncture Research
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• 제18권3호
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• pp.114-122
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• 2001

Objective : The present study was carried out to determine if Juglandis Semen Aquacupuncture(JSA) exerts beneficial effect against the urine concentrating defect induced by glycerol injection in rabbits. Methods : In order to test the effect of JSA, rabbits were acupunctured with $0.5m{\ell}$ of 1%JSA for 7days at both sides of $Sh{\grave{e}}ns{\bar{u}}$(BL23) before the glycerol injection. The other animals were pretreated with an equal volume of saline instead of JSA. Results : The urine flow was reduced, but the urine osmolality was significantly lower than the basal period in glycerol-injected animals, indicating that glycerol causes the urine concentrating defect. The fractional excretion of Na and K was increased in glycerol-treated animals. The Free-water clearance and fractional water excretion(V/GFR) were increased in animals treated with glycerol. Conclusion : These results indicate that glycerol injection resulted an impairment in the urine concentrating ability in rabbits. Such changes were prevented by JSA. JSA may be used as a method to treat and prevent glycerol-induced acute renal failure.

• Current Photovoltaic Research
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• 제4권3호
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• pp.124-129
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• 2016

Recently industry has voiced a need for optimally designing the production process of low-cost, high-quality ingots by improving productivity and reducing production costs with the Czochralski process. Crystalline defect control is important for the production of high-quality ingots. Also oxygen is one of the most important impurities that influence crystalline defects in single crystals. Oxygen is dissolved into the silicon melt from the silica crucible and incorporated into the crystalline a far larger amount than other additives or impurities. Then it is eluted during the cooling process, there by causing various defect. Excessive quantities of oxygen degrade the quality of silicone. However an appropriate amount of oxygen can be beneficial. because it eliminates metallic impurities within the silicone. Therefore, when growing crystals, an attempt should be made not to eliminate oxygen, but to uniformly maintain its concentration. Thus, the control of oxygen concentration is essential for crystalline growth. At present, the control of oxygen concentration is actively being studied based on the interdependence of various factors such as crystal rotation, crucible rotation, argon flow, pressure, magnet position and magnetic strength. However for methods using a magnetic field, the initial investment and operating costs of the equipment affect the wafer pricing. Hence in this study simulations were performed with the purpose of producing low-cost, high-quality ingots through the development of a process to optimize oxygen concentration without the use of magnets and through the following. a process appropriate to the defect-free range was determined by regulating the pulling rate of the crystals.

• Journal of Chest Surgery
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• 제10권1호
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• pp.148-155
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• 1977

The clinical findings with cardioangiography and successful surgical treatment of a 10 year old girl with double-outlet right ventricle is reported at The Dept. of Thoracic and Cardiovascular Surgery, Korea University Hospital, College of Medicine. The patient has been suffered from intermittent cyanosis, palpitation, and exertional dyspnea since 1 year after NFSD, and a holosystolic ejection murmur of grade 4 at the left 3rd intercostal space with mild cyanosis of the lips was the only physical findings at the time of this admission. Cardiac catheterization revealed ventricular septal defect with left to right shunt of 43% and right to left shunt of 10.2%. On cardioangiography from the left ventricle revealed all of the left ventricular outflow shunted into the right ventricle through the large ventricular septal defect, and the aorta originated from the infundibular chamber of the right ventricle with left, anterior sided pulmonary artery. The atria, viscera, and ventricles were normally located, and right ventricular out-flow was narrowed with infundibular hypertrophy and pulmonary valvular stenosis. Surgical correction was accomplished by closure of the ventricular septal defect in such a way that left ventricular outflow was routed via a Teflon felt prosthetic tunnel to the aorta, and pulmonary valvulotomy with infundibulectomy Was done to pass Hegar`s dilator No. 15 for reconstruction of the right ventricular outflow tract. The patient tolerated complete repair and has continued to improve over a period of three months after operation with normal school life. Details of the disease and method of repair are presented with related references.

• Archives of Plastic Surgery
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• 제33권4호
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• pp.474-479
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• 2006

Purpose: To report of a series of successful reconstruction of soft tissue defect on distal leg with extensor digitorum brevis myo-cutaneous flap. Methods: Between April 2002 to December 2004, 7 patients with soft tissue defect on distal leg were operated with Extensor Digiotorum Brevis myocutaneous flap. 6 of these patients had osteomyelitis. Results: Extensor Digiotorum Brevis myocutaneous flap were used in 6 patients and reverse flow flap was used in one patient. Average follow up was 19 months. All flap were survived 100% without any complication and osteomyelitis were controled in all cases. Aesthetic and functional out come were excellent on both recipient and donor sites. Conclusion: The advantages of this flap are effectively control of local wound infection, constant and reliable anatomical structures, adequately thin flap. Technical easiness for raising flap and wide arch of rotation. Extensor Digitorum Brevis myo-cutaneous flap is one of ideal option for the reconstruction of distal leg and foot defects.

• Journal of Chest Surgery
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• 제31권7호
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• pp.718-721
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• 1998

심한 폐동맥고혈압증을 동반한 심실중격결손증을 교정하는 수술은 술후 높은 사망률 때문에 외과의에게 많은 어려움이 있다.. 최근에 술후 급성 우심부전이 발생시 우좌혈류단락이 가능하여 심혈류역학을 개선하는 일방성 판막 팻취를 이용한 수술이 안전한 수술법으로 보고되고 있다. 환자는 20 년 전에 선천성심질환을 진단을 받은 바 있으며, 내원 3 개월 전부터 운동성 호흡곤란이 발생하였고, 정밀검사상 심한 폐동맥 고혈압증을 동반한 심실중격결손증으로 진단되었다. 저자등은 심실중격결손을 첨포를 이용하여 폐쇄하는 대신에 술 후 우심실부전을 예방하는 일방성 판막 팻취를 이용하여 결손을 교정하였다. 환자는 건강한 상태로 술 후 14 일째 퇴원하였으며, 일방성 판막 개구부는 술 후 9 개월에 자연 폐쇄되었고, 12 개월 양호한 상태를 유지하고 있다.