• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.199-199
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• 2009

• Bulletin of the Korean Space Science Society
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• 2007.10a
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• pp.107.1-107.1
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• 2007

• Journal of Korean Foot and Ankle Society
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• v.15 no.3
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• pp.153-158
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• 2011

Purpose: This study was performed retrospectively and to compare the clinical outcomes of the surgical management using Antiglide plating and lateral plating for Danis-Weber type B isolated lateral malleolar fractures. Materials and Methods: Between March 2004 and March 2009, 92 patients were followed up for more than 6 months after surgical treatment. 49 patients were treated with Antiglide plating, whereas the remaining 43 patients underwent lateral plating. The results of the two groups were analyzed both radiographically and clinically using Ankle scoring system. Results: Both groups were comparable for age, sex distribution, time to surgery, and operation time. Bone union was noted at average of 8 weeks in all fractures. The mean ankle score was similar in both groups (94% versus 93%). Conclusion: Antiglide plating for Danis-Weber type B isolated lateral malleolar fracture is one of the good methods which has some advantages such as early ankle motion, ambulation and smaller operative incision.

• Journal of Chest Surgery
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• v.35 no.11
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• pp.822-825
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• 2002

The paravalvular leak after redo mitral prosthetic valve replacement is rare but serious complication when it does happen. This condition should be corrected surgically to increase life span and improve symptoms. But simple closure or patch closure of paravalvular leak are not effective in cases of weak annulus or broad defect. We report 3 cases of trido mitral valve replacement using mechanical valve with its sewing ring expanded by a collar of Dacron sheet. The prosthetic sewing ring is anchored on the weak mitral annulus with multiple interrupted sutures, while the Dacron collar is contineuously sutured to the left atrial wall for blood tight sealing. All of the three cases showed event free postoperative course.

• Journal of Yeungnam Medical Science
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• v.15 no.1
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• pp.164-172
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• 1998

The Graf stabilization has been introduced in treating lumbar spinal disorder associated with posterior instability. This study reviewed some problems of the Graf instrumentation as a soft stabilizer. The purpose of this study is to analyse the problems of the soft stabilization in spinal instability. We reviewed 145 cases which were operative treatment using the Graf instrument for lumbar spinal disorder associated with posterior instability at our department from May, 1991 to Dec, 1995. The mean follow up periods was 29 months ranging from 24 months to 6 years 8 months. Of the 145 cases, 22 cases were showed the problem. The diagnostic method were simple x-ray, flexion-extension lateral stress view and CT scan. Results were as follows: Adjacent segmental instability was 10 cases(6.9%), disc space narrowing was 8 cases(5.5%), screw loosening was 3 cases(2.1%) and breakage of the Graf band was 1 case(0.6%). The problems of the soft stabilization were adjacent segmental instability, disc space narrowing, screw loosening, and breakage of the Graf band. But the rate of adjacent segmental instability and disc space narrowing was lower than other lumbar spinal instrumentation.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.2
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• pp.115-120
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• 2009

Purpose: To evaluate the outcomes of three different surgical approaches in treating a distal radius fracture with dorsal communition. Materials and Methods: From April, 2006 to May, 2009, 49 patients over age of 60years old with unstable dorsal communition distal radius fracture were analyzed. We compared maintainability of reduction by radiological follow-up observations and clinical outcomes using Mayo wrist scores. One-Way ANOVA test was performed to examine the statistical correlation between the methods. Results: All three approaches provided satisfactory post-op reduction results. However, follow-up observations showed significant loss of reduction in the external fixation only group compared to the added bone graft group and the volar anatomical locking plate group (P<0.05). Mayo wrist score was indifferent between the three groups. Conclusion: Treatment of a distal radius fracture with severe dorsal communition using an external fixation only appears to be insufficient in maintaining reduction of a cancellous bone defect.

• Clinics in Shoulder and Elbow
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• v.15 no.1
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• pp.32-36
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• 2012

Purpose: The purpose of this study was to evaluate the radiologic and clinical outcomes after intercalary tricortical iliac bone graft with plate fixation for the nonunion of midshaft clavicular fractures. Material and Methods: Between September 2007 and May 2011, 10 patients who were treated by the intercalary tricortical iliac bone graft, with plate fixation for clavicle nonunion, were studied. The mean follow-up period was 30.7 (12~57) months. After the sclerotic bone was excised to the bleeding cortical bone, we interposed the tricortical iliac bone to provide structural support and restore clavicle length, and then fixed the plate and screws. The radiologic outcomes on the serial plain radiographs and clinical outcomes, according to UCLA, ASES and Quick DASH scores, were analyzed. Results: Bony union was obtained in all cases (100%) and the average union time was 18.4 (14~24) weeks. The average respective UCLA and ASES scores improved from 16.7 and 52.1 preoperatively to 27.4 and 83.6 postoperatively (p<0.05). The average Quick DASH score was 40.5, at the final follow-up. Complications were 2 shoulder stiffness, and one case had removal of device and arthroscopic surgery at 11 months, postoperatively. There were no implant failure or infection. Conclusion: Intercalary tricortical iliac bone graft, with plate fixation for the nonunion of midshaft clavicular fractures, is a good option that can provide structural support and restore clavicle length, as well as high union rate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.299-308
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• 2001

This paper presents the three-dimensional (3-D) study of the natural vibration of cantilevered laminated composite plates. The Ritz method is used to obtain stationary values of the associated Lagrangian functional with displacements approximated by mathematically complete polynomials satisfying the boundary conditions at the clamped edge exactly. The accuracy of the 3-D model is established through a convergence study of non-dimensional frequencies followed by a comparison of the converged 3-D solutions with analytical and experimental findings in the existing literature. A wide scope of 3-D frequency results explain the influence of a number of geometrical and material parameters for cantilevered laminated plates, namely aspect ratio (a/b), width-to-thickness ratio (a/h), orthotropy of material, number of plies (NP), fiber orientation angle(θ), and stacking sequence.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.205-205
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• 2022

본 연구에서는 심해 선형파 조건에서 수중 투과성 방파제 주변의 유속장에 대해 nonhomogeneous Riemann-Hilbert problem을 이용한 해석해 및 수치해를 도출하고, 이를 반사계수와 투과계수를 산정하는 데에 활용한다. 여러 개의 얇은 투과성 판이 일렬로 배열되어 수중에 고정되어있고 규칙파가 작용하는 경우, Riemann-Hilbert problem을 정의할 수 있다. 본 연구에서는 얇은 판으로 이루어진 수중 방파제에 대한 homogeneous Riemann-Hilbert problem을 푸는 것을 넘어, 투과성 판으로 이루어진 수중 방파제에 대해 nonhomogeneous Riemann-Hilbert problem을 정의하고, 이에 대해 무한경계조건과 판 근처에서의 유속장 경계조건을 이용해 해석해를 유도하였다. 투과성 방파제의 경우 permeable boundary를 가지므로 제시한 상황은 기하학적 비선형성을 지닌다. 이에 대해 투수성을 기초로 미소 매개변수를 정의하고, 섭동법(perturbation method)을 이용해 유속장에 대한 leading order solution과 first order solution을 도출하였다. Leading order solution은 Evans (1970) 등의 선행연구에서 제시한 해와의 비교를 통해 그 타당성을 검증하였고, First order solution을 이용해 반사계수와 투과계수를 산정하여 방파제의 투수성이 유속장에 미치는 영향을 고려하였다. 아울러 수치해를 도출하여 해석해의 결과와 비교 및 분석하였다. 본 연구에서 제시한 해석해는 방파제에 가해지는 힘을 산정하는 등 다양한 방향으로 활용 가능하며, 향후 수치해나 실험값을 비교, 검증하기 위한 기초 자료로써 활용될 수 있다.

• Composites Research
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• v.14 no.3
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• pp.42-50
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• 2001

Modeling of damage initiation in singly oriented ply (SOP) Fiber Metal Laminate (FML) under concentrated loading conditions was studied. The finite element method (FEM) base on the first order shear deformation theory is used for th\ulcorner modeling of damage initiation in SOP FML. The failure indices (FI) of the fiber prepreg and the metal laminate were calculated by using the Tasi-Hill failure criterion and the Miser yield criterion, respectively. To verify the present method, the failure analysis was conducted under uniaxial loading and cylindrical bending, then the analysis under concentrated load was conducted. The results show that the analysis is reasonable. An indentation test was conducted to compare a damage initiation load with a calculated FI. The test was conducted under two side clamped conditions to study the fiber orientation effect. Indentation curve was fitted using the Hertz equation and a damage initiation load is defined that the point which deviate the fitted curve from the real indentation curve. The damage initiation loads were obtained under various fiber orientations and compared with calculated FIs. The experiment was well matched with calculated FI. This results shows that the present method is suitable for the damage initiation modeling of SOP FML.