• Composites Research
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• v.34 no.1
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• pp.70-75
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• 2021

This paper presents a novel algorithm to reconstruct meso-scale representative volume elements (RVE), referring to experimentally observed features of Sheet Molding Compound (SMC) composites. Predicting anisotropic mechanical properties of SMC composites is challenging in the multiscale virtual test using finite element (FE) models. To this end, an SMC RVE modeler consisting of a series of image processing techniques, the novel reconstruction algorithm, and a FE mesh generator for the SMC composites are developed. First, micro-CT image processing is conducted to estimate probabilistic distributions of two critical features, such as fiber chip orientation and distribution that are highly related to mechanical performance. Second, a reconstruction algorithm for 3D fiber chip packing is developed in consideration of the overlapping effect between fiber chips. Third, the macro-scale behavior of the SMC is predicted by the multiscale analysis.

• Journal of Chest Surgery
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• v.29 no.4
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• pp.472-476
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• 1996

Malignant flrous histiocytoma is a rare deep-seated pleomorphlc sarcoma, although its incidence Increasing. In this report, we present a case of a malignant fibrous histiocytoma, arising in the left chest wall in a 37-year-ol4 male patient. He underwent radical on bloc resection which include excision of tumor on left upper chest wall with resection of ribs from the first to third, left upper lo ectomy and chest wall reconstruction with Marled Mesh. However, he had local recurrence and distant metastasis within 12 months of the original operation. Malignant fibrous histiocytoma is an agrressive disease entity, with a propensity for early and distant spread.

• Journal of the Semiconductor & Display Technology
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• v.20 no.4
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• pp.6-9
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• 2021

The 3D industry is drawing attention for its applications in various markets, including architecture, media, VR/AR, metaverse, imperial broadcast, and etc.. The current feature of the architecture we are introducing is to make 3D models more easily created and modified than conventional ones. Existing methods for generating 3D models mainly obtain values using specialized equipment such as RGB-D cameras and Lidar cameras, through which 3D models are constructed and used. This requires the purchase of equipment and allows the generated 3D model to be verified by the computer. However, our framework allows users to collect data in an easier and cheaper manner using cell phone cameras instead of specialized equipment, and uses 2D data to proceed with 3D modeling on the server and output it to cell phone application screens. This gives users a more accessible environment. In addition, in the 3D modeling process, object classification is attempted through deep learning without user intervention, and mesh and texture suitable for the object can be applied to obtain a lively 3D model. It also allows users to modify mesh and texture through requests, allowing them to obtain sophisticated 3D models.

• Archives of Plastic Surgery
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• v.46 no.5
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• pp.462-469
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• 2019

Background Incisional hernia is a common complication following visceral organ transplantation. Transplant patients are at increased risk of primary and recurrent hernias due to chronic immune suppression and large incisions. We conducted a retrospective review of patients with a history of liver or kidney transplantation who underwent hernia repair to analyze outcomes and hernia recurrence. Methods This is a single center, retrospective review of 19 patients who received kidney and/or liver transplantation prior to presenting with an incisional hernia from 2011 to 2017. All hernias were repaired with open component separation technique (CST) with biologic mesh underlay. Results The mean age of patients was $61.0{\pm}8.3years\;old$, with a mean body mass index of $28.4{\pm}4.8kg/m^2$, 15 males (78.9%), and four females (21.1%). There were seven kidney, 11 liver, and one combined liver and kidney transplant patients. The most common comorbidities were hypertension (16 patients, 84.2%), diabetes (9 patients, 47.4%), and tobacco use (8 patients, 42.1%). Complications occurred in six patients (31.6%) including hematoma (1/19), abscess (1/19), seroma (2/19), and hernia recurrence (3/19) at mean follow-up of $28.7{\pm}22.8months$. With the exception of two patients with incomplete follow-up, all patients healed at a median time of 27 days. Conclusions This small, retrospective series of complex open CST in transplant patients shows acceptable rates of long-term hernia recurrence and healing. By using a multidisciplinary approach for abdominal wall reconstruction, we believe that modified open CST with biologic mesh is a safe and effective technique in the transplant population with complex abdominal hernias.

• Journal of computational fluids engineering
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• v.19 no.3
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• pp.52-61
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• 2014

The present paper deals with the efficient computation of higher-order CFD methods for compressible flow using graphics processing units (GPU). The higher-order CFD methods, such as discontinuous Galerkin (DG) methods and correction procedure via reconstruction (CPR) methods, can realize arbitrary higher-order accuracy with compact stencil on unstructured mesh. However, they require much more computational costs compared to the widely used finite volume methods (FVM). Graphics processing unit, consisting of hundreds or thousands small cores, is apt to massive parallel computations of compressible flow based on the higher-order CFD methods and can reduce computational time greatly. Higher-order multi-dimensional limiting process (MLP) is applied for the robust control of numerical oscillations around shock discontinuity and implemented efficiently on GPU. The program is written and optimized in CUDA library offered from NVIDIA. The whole algorithms are implemented to guarantee accurate and efficient computations for parallel programming on shared-memory model of GPU. The extensive numerical experiments validates that the GPU successfully accelerates computing compressible flow using higher-order method.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.44-47
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• 2004

This paper proposes an approach for composite surface reconstruction from 2D serial cross-sections, where the number of contours varies from section to section. In a triangular surface-based approach taken in most reconstruction methods, a triangular $G^{1}$ surface is constructed by stitching triangular patches over a triangular net generated from the compiled contours. In the proposed approach, the resulting surface is a composite $G^{1}$ surface consisting of three kinds of surfaces: skinned, surface is first represented by a B-spline surface approximating the serial contours of the skinned region and then serial contours of the skinned region and then transformed into a mesh of rectangular Bezier patches. On branched and capped regions, triangular $G^{1}$ surfaces are constructed so that the connections between the triangular surfaces and their neighboring surfaces are $G^{1}$ continuous. Since each skinned region is represented by an approximated rectangular $G^{2}$ surface instead of an interpolated triangular $G^{1}$ surface, the proposed approach can provide more visually pleasing surfaces and realize more efficient data reduction than the triangular surface-based approach. Some experimental results demonstrate its usefulness and quality.

• Korean Journal of Optics and Photonics
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• v.17 no.4
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• pp.359-365
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• 2006

Wave-front error(WFE) is the main parameter that determines the optical performance of the opto-mechanical system. In the development of opto-mechanics, WFE due to the main loading conditions are set to the important specifications. The deformation of the optical surface can be exactly calculated thanks to the evolution of numerical methods such as the finite element method(FEM). To calculate WFE from the deformation results of FEM, another approximation of the optical surface deformation is required. It needs to construct additional grid or element mesh. To construct additional mesh is troublesomeand leads to transformation error. In this work, the moving least-squares approximation is used to reconstruct wave front error It has the advantage of accurate approximation with only nodal data. There is no need to construct additional mesh for approximation. The proposed method is applied to the examples of GOCI scan mirror in various loading conditions. The validity is demonstrated through examples.

• Archives of Reconstructive Microsurgery
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• v.10 no.2
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• pp.163-168
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• 2001

The defects of the abdominal wall could be brought about either congenitally, for instances in such cases as omphalocele or gastroschisis, or by various acquired causes-trauma, excision of tumors, excision of burn scar, tissue necrosis caused by infection, hematoma after abdominal surgery, tissue necrosis after radiation therapy and so on. As for the techniques of the reconstruction of the abdominal wall defects, many authors have developed and reported diverse methods. To summarize, primary closure, skin graft, local skin flaps, various myocutaneous flaps, free flap, fascia graft, artificial mesh, tissue expansion, etc could be used in the reconstruction of the abdominal wall defects. The periumbilical perforator-based island skin flap has a many advantages such as no significant sacrifice of the rectus abdominis muscle, wide rotation arc, reliable blood flow of the perforator, short elevation time for flap, and for middle-aged, obese patients, the donor site may be the best from the cosmetic point of view. We used perforator-based island skin flap in 5 cases with reasonable result from March 1999 to May 2001. There were no significant complications and donor sites could be repaired primarily.

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.35-42
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• 2011

Purpose: Blow-out fractures can be reduced using various methods. The orbital reconstruction technique using a balloon under endoscopic control has advantages over other methods. However, this method has some problems too, such as postoperative follow-up, management of the balloon catheter, and reduction of the posterior orbital floor. Thus, we developed a simple, effective method for orbital floor reduction that involves molding and shaping the antral balloon catheter. Methods: A 0, 30, or $70^{\circ}$, 4-mm endoscope was placed though a two-point, 5-mm maxillary antrostomy. The balloon catheter is placed directly at the orbital apex to reconstruct the anterior shelf (spherical shape), while it is turned in a U-shape towards the anterior maxilla for the posterior shelf (elliptical shape). Orbital floor defects, compound or comminuted fractures are reconstructed with alloplastic materials through an open lid incision under the endoscopic control. Results: This technique was applied to ten patients with orbital floor fractures: five anterior shelf and five posterior shelf fracture, respectively. Four of the patients had zygomatico-orbital fractures, while the rest had isolated orbital floor fractures. Two patients were given porous polyethylene implants Synpor$^{(R)}$) and three underwent reconstruction with a resorbable mesh plate. No complication associated with this technique was identified. Conclusion: The freestyle placement and selection of a urinary balloon catheter under endoscopic control and the preoperative estimation of the volume enhanced the stabilization of the orbital contour. This method improves the adaptation of the orbital floor without the risk of injuring the surrounding orbital contents, dissecting blindly, or using sharp traction. One drawback of this method is the patient's discomfort from the catheter during treatment.

• Archives of Plastic Surgery
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• v.39 no.1
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• pp.31-35
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• 2012

Background : Orbital roof fractures are frequently associated with a high energy impact to the craniofacial region, and displaced orbital roof fractures can cause ophthalmic and neurologic complications and occasionally require open surgical intervention. The purpose of this article was to investigate the clinical features and treatment outcomes of orbital root fractures combined with neurologic injuries after early reconstruction. Methods : Between January 2006 and December 2008, 45 patients with orbital roof fractures were admitted; among them, 37 patients were treated conservatively and 8 patients underwent early surgical intervention for orbital roof fractures. The type of injuries that caused the fractures, patient characteristics, associated fractures, ocular and neurological injuries, patient management, and treatment outcomes were investigated. Results : The patients underwent frontal craniotomy and free bone fragment removal, their orbital roofs were reconstructed with titanium micromesh, and associated fractures were repaired. The mean follow up period was 11 months. There were no postoperative neurologic sequelae. Postoperative computed tomography scans showed anatomically reconstructed orbital roofs. Two of the five patients with traumatic optic neuropathy achieved full visual acuity recovery, one patient showed decreased visual acuity, and the other two patients completely lost their vision due to traumatic optic neuropathy. Preoperative ophthalmic symptoms, such as proptosis, diplopia, upper eyelid ptosis, and enophthalmos were corrected. Conclusions : Early recognition and treatment of orbital roof fractures can reduce intracranial and ocular complications. A coronal flap with frontal craniotomy and orbital roof reconstruction using titanium mesh provides a versatile method and provides good functional and cosmetic results.