• 대한치과교정학회지
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• 제20권1호
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• pp.169-179
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• 1990

Utilizing the repelling force of permanent magnet of find out weather it shows the findings of molar intrusion histologically and compares the result with the resin bite plane. As for the experimental animals, 10 cats of completion of permanent dentition with mean weight of 2.2kg which have flat occlusal plane of molar areas were used. I raised the cats under the condition of their being attached with manufactured appliance by direct bonding system and of their wearing vertical chin strap anesthetized for 12-14 hours per day through 5 days. Then, observing the root apex areas with lightmicroscope. The results were as follows; 1. In the group with resin bite plane, osteoblasts and osteoclasts could not find out but could find out periodontal ligment fiber obliquely angulated in the apical and lingual direction. 2. In the group with the permanent magnet, not only the obliquely angulated periodontal ligament fiber but also the osteoclasts at the apical areas were observed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1598-1606
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• 2007

In this paper, we present a thin circular beam finite element for the out-of-plane vibration analysis of curved beams. The element stiffness matrix and the element mass matrix are derived respectively from the strain energy and the kinetic energy by using the natural shape functions which are obtained from an integration of the differential equations of the finite element in static equilibrium. The matrices are formulated with respect to the local polar coordinate system or to the global Cartesian coordinate system in consideration of the effects of shear deformation and rotary inertias. Some example problems are analysed. The FEM results are compared with the theoretical ones to show that the presented finite element can describe quite efficiently and accurately the out-of-plane motion of thin curved beams.

• 한국강구조학회 논문집
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• 제25권1호
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• pp.93-102
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• 2013

본 연구에서는 철근콘크리트 벽과 강판 콘크리트 벽이 서로 수직면의 이질접합 형태로 만나는 벽의 면외 휨 거동 특성을 검토하기 위하여, L형 실험체를 제작하고 휨 실험을 수행하였다. 실험 시, 실험체의 동적특성을 확인하기 위하여 Push 및 Pull 하중을 반복하는 싸이클 하중을 구현하고자 하였다. Push 하중에 의한 실험 결과, 실험체의 공칭강도를 초과하는 휨 성능을 발휘하였으며, 이에 따라 설계에 적용된 수직철근의 미겹침 이음길이의 타당성을 확인할 수 있었다. 한편, Pull 하중 가력 시에는 수직철근이 최대 내력을 발휘하기 전에 접합부 콘크리트에서 전단 파괴 거동이 나타나, 이에 대한 보강이 필요함을 확인하였다.

• 한국강구조학회 논문집
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• 제19권1호
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• pp.129-137
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• 2007

본 연구에서는 X-브레이싱 접합부의 경계조건에 따른 탄성 면외 좌굴하중 및 유효 좌굴길이 계수에 관한 연구를 수행하였다. X-브레이싱의 접합부는 연결방법에 따라 강접합 혹은 단순 연결로 가정할 수 있으며, 이러한 접합부의 경계 조건은 X-브레이싱의 좌굴하중에 영향을 미친다. 본 연구에서는 접합부의 경계 조건에 따른 X-브레이싱의 면외 유효 좌굴길이 계수들을 유도 하였으며, 면외 유효 좌굴계수들은 압축부재와 인장부재의 길이비 $L_P$/$L_T$, 인장력과 압축력의 비 T/P, 및 인장부재와 압축부재의 Euler 좌굴하중의 비 $P_{ET}$/$P_{EP}$의 함수로 나타났다. 이러한 연구결과는 기존 연구자들 및 유한요소해석결과와 비교 분석하여 그 타당성과 적용성을 검증하였다. 마지막으로 유도된 면외 유효 좌굴길이 계수들을 비교하여 접합부의 경계 조건이 X-브레이싱의 면외 좌굴하중에 미치는 영향을 분석하였다.

• Archives of Plastic Surgery
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• 제35권5호
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• pp.545-552
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• 2008

Purpose: The transaxillary approach for breast augmentation has been advocated for patients and surgeons for several decades. However, this blind technique had many disadvantages including, traumatic dissection, difficult hemostasis, displacement of implants, and ill-defined asymmetrical location of inframammary crease. In the present study, the precise endoscopic electrocautery dissection was applied to eliminate the limits of blunt dissection throughout the procedures. Methods: From December 2006 to December 2007, a total of 103 patients with an average age of 29.5 years underwent endoscopic assisted transaxillary dual plane augmentation mammoplasty. The mean implant size was 243 cc with the range between 150 and 350 cc. Through a 4 cm axillary incision, electrocautery dissection for submuscular pockets was carried out under the endoscopic control. The costal origin of pectoralis muscle was completely divided to expose subcutaneous tissue and to make type I dual plane. Results: Using the endoscopic dissection, we achieved good aesthetic results including a short recovery period, less morbidity, and symmetrical well-defined inframammary crease. Type I dual plane procedure could support the consistent inframammary fold shape and be applied to most patients without breast ptosis. Minor complications did not occur, however, four major complications of capsular contracture occurred. Conclusion: In contrast to the era of the blind techniques, endoscopic assisted transaxillary dual plane breast augmentation can now be performed effectively and reproducibly. With Its advantage, the axillary application of endoscopy for augmentation mammaplasty is useful to achieve the optimal cosmetic outcomes.

• 콘크리트학회지
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• 제10권4호
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• pp.113-124
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• 1998

축력과 면내 및 면외의 두방향 휨모멘트를 받는 철근콘크리트 벽체에 대한 비선형 해석연구를 수행하였으며 , 해석결과를 분석하여 벽체의 강도산정법을 유도하였다. 비선형 해석연구를 위하여 철근콘크리트 벽체에 대한 재료 및 기하학적 비선형 해석을 수행할 수 있는 유한요소 해석방법을 개발하였다. 철근콘크리트의 재료모델로서 소성이론과 파괴모델의 통합모델을 사용하였다. 철근콘크리트 벽체에 대한 해석결과를 토대로 단면의 응력분포를 이상화하였으며, 이를 이용하여 새로운 강도산정법을 개발하였다. 이 방법에 따르면, 면외 휨모멘트에 의하여 단위길이의 벽체가 지지할 수 있는 축력이 결정되며, 이 허용 단위 축력에 따라서 총 축력과 면내 휨모멘트의 상호관계곡선이 결정된다. 면외 휨모멘트가 증가할수록 축력과 면내 휨모멘트의 상호관계곡선이 축소되며 이는 벽체 강도의 감소를 가리킨다. 이 새로운 방법을 , 휨변형후에도 단면이 평면으로 유지된다는 가정을 사용하는 기존의 강도산정법과 비교한다. 이 비교결과에 따르면 , 새로운 방법에 비하여 기존의 방법은 면외 휨모멘크가 작은 영역에서 벽체의 강도를 과소평가하며, 면외 휨모멘트가 큰 영역에서는 벽체의 강도를 과대평가한다.

• Journal of Welding and Joining
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• 제17권4호
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• pp.76-84
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• 1999

The residual stress generated when the steel plates were produced, did not influence on the out-of-plane deformation and residual stress generated by welding. When the initial deflection shape was a concave(Type I), the out-of-plane deformation became the same shape as that of the initial deflection and its magnitude became small. When the initial deflection made a winding in the welding direction(Type III), the out-of-plane deformation became large in the plate width. The initial deflection shape did not influence on residual stress and plastic strain produced by welding.

• 소음진동
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• 제10권5호
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• pp.849-858
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• 2000

In this paper the chaotic out-of-plane vibrations of the uniformly curved pipe with pulsating flow are theoretically investigated. The derived equations of motion contain the effects of nonlinear curvature and torsional coupling. The corresponding nonlinear ordinary differential equation is a type of nonhomogenous Hill's equation . this is transformed into the averaged equation by averaging theorem. Bifurcation curves of chaotic motion are obtained by Melnikov's method and plotted in several cases of frequency ratios. The theoretically obtained results are demonstrated by numerical simulation. And strange attractors are shown.

• Structural Engineering and Mechanics
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• 제45권5호
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• pp.613-629
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• 2013

In this article we will present a method to directly evaluate the critical point of a non-linear system by using the solution of a polynomial eigenvalue approximation as a starting point for an iterative non-linear system solver. This method will be used to evaluate out-of-plane buckling properties of truss structures for which the lateral displacement of the upper chord has been prevented. The aim is to assess for a number of example structures whether or not the linearized eigenvalue solution gives a relevant starting point for an iterative non-linear system solver in order to find the minimum positive critical load.

• 제어로봇시스템학회논문지
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• 제15권9호
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• pp.881-886
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• 2009

This paper presents a manipulation system consisting of a coarse/fine XY positioning system and an out-of-plane manipulator. The object of the system is to conduct tine positioning and manipulation of micro parts. The fine stage and the out-of-plane manipulator have compliant mechanisms with flexure hinges, which are driven by stack-type piezoelectric elements. In the fine stage, the compliant mechanism plays the roles of motion guide and displacement amplification. The out-of-plane manipulator contains three piezo-driven compliant mechanisms for large working range and fine resolution. For large displacement, the compliant mechanism is implemented by a two-step displacement amplification mechanism. The compliant mechanisms are manufactured by wire electro-discharge machining for flexure hinges. Experiments demonstrate that the developed system is applicable to a fine positioning and fine manipulation of micro parts.