• Journal of Chest Surgery
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• 제23권4호
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• pp.720-730
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• 1990

The complicated pulmonary emphysema including “Giant bullae” and spontaneous pneumothorax often involve both lungs, and controversy exists concerning which is the more rational means of surgical treatment-bilateral simultaneous operation or two staged operation. We report three cases of the complicated bilateral bullous emphysema and two cases of bilateral spontaneous pneumothorax treated through median sternotomy. We performed the ligation of bullae, bullectomy, cystectomy, wedge resection, and left lower lobectomy through median sternotomy. No technical problems were encountered through this approach, which provided maximum benefit with one operation In conclusions, median sternotomy may be appropriate for resection of emphysematous bullae, specially in a severe COPD patient who may be poorly tolerated the superimposed loss of respiratory function due to incisional pain, because median sternotomy permit bilateral exploration, minimal impairment of pulmonary function, simultaneous restoration of pulmonary function, less incisional pain than routine lateral thoracotomy.

• 대한두경부종양학회지
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• 제21권2호
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• pp.190-195
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• 2005

Background and Objectives: Fibula is the flap of choice for reconstruction of wide mandible defects after tumor ablation surgery. In mandible reconstruction, restoring the mandible frame to provide mandibular contour and dental arch while restoring masticatory function are important. Even though vascularized fibula can be osteotomized freely, proper design and flap insetting is not easy because of its three dimensional structure and difference in design according to the defect sites. We reviewed patients who underwent mandible reconstruction with fibular flaps according to the defect sites and suggest proper modification methods of fibular flap according to the various defects sites after tumor ablation surgery. Materials and Methods: Twelve consecutive mandible reconstruction with fibular free flaps were performed for defects after tumor ablation surgery. Patients were classified into 4 groups according to the type of mandibular defect(Group 1 : defect on central segment including symphysis, Group 2 : defect on lateral segment(with or without central segment) confined to body, Group 3 : defect on body and ascending ramus that does not include the condyle, Group 4 : defect including the condyle). Results: We suggest different modification methods of fibular free flap for each patient group. Group 1, 3 ; contour by using multiple closing wedge osteotomy. Group 2 ; single or double barrel reconstruction without wedge osteotomy. Group 4 ; contour using single or multiple wedge osteotomy and condylar reconstruction with costochondral graft. Conclusion: Fibular free flaps can be contoured to any desired shape after multiple osteotomies to restore various mandibular defects. It is a reliable and versatile method for reconstruction of mandibular defects after tumor ablation surgery.

• 대한조선학회논문집
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• 제57권1호
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• pp.23-34
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• 2020

This paper covers the development of prediction techniques for ice load on ice-breakers operating in continuous ice-breaking under level ice conditions using particle-based continuum mechanics. Ice is assumed to be a linear elastic material until the fracture occurs. The maximum normal stress theory is used for the criterion of fracture. The location of the crack can be expressed using a local scalar function consisting of the gradient of the first principal stress and the corresponding eigen-vector. This expression is used to determine the relative position of particle pair to the new crack. The Hertz contact model is introduced to consider the collisions between ice fragments and the collisions between hull and ice fragments. In order to verify the developed technique, the simulation results for the three-point bending problems of ice-specimen and the continuous ice-breaking problem around a wedge-type model ship with bow angle of 20° are compared with the experimental results carrying out at Korea Research Institute of Ships and Ocean Engineering (KRISO).

• Tribology and Lubricants
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• 제34권6호
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• pp.247-253
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• 2018

Temperature rise due to viscous shear of the lubricating oil generates hydrodynamic pressure, even if the lubricating surfaces are parallel. This effect, known as the thermal wedge effect, varies significantly with film-temperature boundary conditions. The bearing conducts a part of the heat generated; hence, the oil temperature varies with the thermal conductivity of the bearing. In this study, we analyze the effect of thermal conductivity on the thermohydrodynamic (THD) lubrication of parallel slider bearings. We numerically analyze the continuity equation, Navier-Stokes equation, energy equation including the temperature-viscosity and temperature-density relations for lubricants, and the heat conduction equation for bearing by creating a 2D model of the micro-bearing using the commercial computational fluid dynamics (CFD) code FLUENT. We then compare the variation in temperature, viscosity, and pressure distributions with the thermal conductivity. The results demonstrate that the thermal conductivity has a significant influence on THD lubrication characteristics of parallel slider bearings. The lower the thermal conductivity, the greater the pressure generation due to the thermal wedge effect resulting in a higher load-carrying capacity and smaller frictional force. The present results can function as the basic data for optimum bearing design; however, the applicability requires further studies on various operating conditions.

• 한국음향학회지
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• 제10권3호
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• pp.13-18
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• 1991

본 연구에서는 취약한 고체의 표면에 존재하는 crack에 탄성표면파를 입사 시켰을 때 발생하는 반사계수를 측정하여 파괴응력을 해석하는 방법을 연구 분석하였다. Crack이 존재하는 취약한 고체에서의 파괴응력은 임계응력확대계수와 정규화된 최대응력확대계수의 함수로써 나타나며, 이 때 정규화된 최대응력확대계수는 탄성표면파의 반사계수를 측정하여 구할 수 있었다. 실험을 위하여 Pyrex glass원판 중앙에 깊이가 0.5mm~0.9mm인 crack을 제작하였고, SAW wedge transducer를 피치캐치(pitch-catch) 모드로 구성하여 반사계수를 측정하고 파괴응력값을 산출하였으며 UTM(Universal Testing Machine)으로 측정한 값과 비교 분석하였다.

• 대한조선학회논문집
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• 제45권5호
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• pp.477-486
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• 2008

Numerical analysis for slamming impact phenomena has been carried out when 2-dimensional wedge shaped structure with finite deadrise angles enter the free surface by using a commertial CFD code, FLUENT. Fluid is assumed incompressible and entry speed of the structure is kept constant. Geo-reconstruct scheme (or PLIC-VOF scheme) is used for the tracking of the deforming free surface. User defined function of 6 degrees of freedom motion and moving dynamic mesh option are used for the expression of the downward motion of the structure and deforming of unstructured meshes adjacent to the structure. The magnitude and the location of impact pressure and the total drag force which is the summation of pressures distributed at the bottom of the structure are analyzed. Results of the analysis show good agreement with the results of similarity solution, asymptotic solution and the solution of BEM.

• 복식문화연구
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• 제16권6호
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• pp.1156-1168
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• 2008

This study investigated the preceding studies and concept of Glam Rock style, modernistically reinterpreted its aesthetic function and symbolism and connected them to design. It analyzed according to the standards for classification the Glam Rock style appearing mainly in the collections from 2002 S/S to 2007 S/S and presented four pieces of design through the analysis. Its findings are synthesized as follows. First, unstructured design constitutes mule stressing gold cubic overall. It takes an unstable form by the placement of unshapely front ball of foot from transforming Chopin and a relatively poor heel. Second, over trimming constitutes separated pumps in the form of over trimming irregularly a piece of broken glass, metal and thumb tack. Third, Mix & Match combines Boot body of flexible knit material with an acrylic wedge sandal. Fourth, a platform sandal has the structure of color contrast between yellow and bronze in calf fur of tiger-skin pattern. I hope that this study will be developed by reflecting Glam Rock spirit and style as cultural phenomena through analyzing Glam Rock style and presenting design according to selected standards for classification, inferring plastic beauty of fashion shoes from them, investigating the change and feature of age-specific shoe design and making a new attempt possible.

• Journal of Chest Surgery
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• 제37권1호
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• pp.98-101
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• 2004

복합 국소 동통 증후군은 외상이나 수술을 받았던 환자에게서 수술과 상관없는 사지 말단 부위의 동통, 이상 통증과 피부 온도, 색깔과 일치하지 않는 혈관 운동 이상, 발한 이상, 운동 장애와 위축이 나타나는 경우를 말한다. 말초나 중추에 있는 통증 수용체의 catecholamine에 대한 민감도가 증가되어 생기며 적외선 체열 검사를 통해 온도 차이를 확인하면 진단할 수 있으며 치료는 통증을 덜어주기 위한 치료와 장애가 있는 팔이나 다리의 기능 회복을 위한 재활 치료를 병행한다. 16세 남자에게서 수술 후 통증으로 야기된 수술 외 국소 부위에 생겨난 복합 국소 동통 증후군을 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 한국해양공학회지
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• 제21권3호
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• pp.8-15
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• 2007

This study is intended to examine the relationship between the magnitude of sand spit in the estuary of the stream and improvement of the quality of water that flaws into the sea, by means of hydraulic experimentation. In order to determine the effect of improvements of water quality when river flow is stagnant, the estuary flows into the sea through the small sand spit, and a two-dimensional physical model experiment was carried out. Distribution of concentration was decreased in response to an increase in length of sand spit and time. The experimental results are compared with theoretical results, based on the solution of the equation. Also, there are functions of influx prevention of salt wedge and purification of pollution water due to sand spit in small estuary.

• 한국통신학회논문지
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• 제36권4A호
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• pp.325-328
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• 2011

본 논문에서는 기하학적인 관점으로 이변량 가우시안 Q-함수의 Craig 표현에 대한 새롭고 간단한 유도를 제시하고 있다. 또한, 이러한 기하학적인 유도는 이변량 가우시안 Q-함수의 또 다른 Craig 표현 식을 제시하고 있다. 새롭게 유도된 이변량 가우시안 Q-함수의 Craig 식은 2개의 상관 가우시안 잡음에서 직교좌표의 변환으로 생성되는 2개 웨지 영역의 기하학으로부터 새롭게 구한 것이다. 제시된 Craig 형태는 이변량 가우시안 Q-함수로 표현되는 확률을 계산하는데, 중요한 역할을 할 수 있다.