• Archives of Plastic Surgery
• /
• 제50권1호
• /
• pp.3-9
• /
• 2023

Background In breast reconstruction, synthetic meshes are frequently used to replace acellular dermal matrix (ADM), since ADM is expensive and often leads to complications. However, there is limited evidence that compares the types of substitutes. This study aimed to compare complications between materials via a network meta-analysis. Methods We systematically reviewed studies reporting any type of complication from 2010 to 2021. The primary outcomes were the proportion of infection, seroma, major complications, or contracture. We classified the intervention into four categories: ADM, absorbable mesh, nonabsorbable mesh, and nothing used. We then performed a network meta-analysis between these categories and estimated the odds ratio with random-effect models. Results Of 603 searched studies through the PubMed, MEDLINE, and Embase databases, following their review by two independent reviewers, 61 studies were included for full-text reading, of which 17 studies were finally included. There was a low risk of bias in the included studies, but only an indirect comparison between absorbable and non-absorbable mesh was possible. Infection was more frequent in ADM but not in the two synthetic mesh groups, namely the absorbable or nonabsorbable types, compared with the nonmesh group. The proportion of seroma in the synthetic mesh group was lower (odds ratio was 0.2 for the absorbable and 0.1 for the nonabsorbable mesh group) than in the ADM group. Proportions of major complications and contractures did not significantly differ between groups. Conclusion Compared with ADM, synthetic meshes have low infection and seroma rates. However, more studies concerning aesthetic outcomes and direct comparisons are needed.

• 동력기계공학회지
• /
• 제6권4호
• /
• pp.30-35
• /
• 2002

This study represents the effects of the material of the air cleaner on the performance in a 4-stroke spark-ignition engine for motorcycles. This study is mainly focused on the possibility of the adopting the STS wire mesh air cleaner of a S.I engine. For investigating the possibility of that, the engine power, the fuel consumption and the exhaust gas analysis were carried out for the synthetic fiber air cleaner and the different size of 200 mesh, 250 mesh, 300 mesh of STS wire mash air cleaner. As the results of this study, the performance of STS wire air cleaner was similar to the fiber air cleaner at 9000 rpm but 300 mesh of STS air cleaner had a high engine power and torque at 9500 rpm. In the case of the synthetic fiber air cleaner the concentration of CO was low at 6500 rpm and in the case of the 300 mesh in STS wire mesh air cleaner the concentration of HC was lowest at all experimental regions.

• Archives of Plastic Surgery
• /
• 제33권5호
• /
• pp.643-647
• /
• 2006

Purpose: The transverse rectus abdominis myocutaneous(TRAM) flap has become a mainstay of breast reconstruction. The chief disadvantage of the TRAM flap is its potential to create a weakness in the abdominal wall. Nowadays true hernia is less frequent, but bulging that appears at the muscle donor site, or at the contralateral side, or at the epigastric area is still remained as a problem. To prevent this complications, we have used synthetic mesh as well as abdominal muscle plication. Now we report the result of our methods. Methods: We started to use synthetic mesh and muscle plication as supplementary reinforcement for entire abdominal wall, after TRAM flap harvesting, in an attempt to stabilize it and achieve a superior aesthetic result since 2002. We observed complications of TRAM flap donor site, and compared our results (from January, 2002 to January, 2006) with other operator's result (before 2001) at the same hospital in aspect of incidence of abdominal complications. Results: 42 consecutive patients have been performed routine reinforcement with the extended mesh technique and muscle plication from January, 2002 to January, 2006. Mean patient follow up was 25.2 months. No hernia or mesh related infection were encountered and only one patient had a mild abdominal bulging. Nevertheless the our good results, there were no significant statistical differences were observed between two groups. Conclusion: We recommend the using of synthetic mesh and muscle plication for donor site reconstruction after TRAM flap breast reconstruction to improve strength as well as aesthetic quality of the abdominal wall.

• Archives of Plastic Surgery
• /
• 제46권5호
• /
• pp.470-474
• /
• 2019

Congenital absent sternum is a rare birth defect that requires early intervention for optimal long-term outcomes. Descriptions of the repair of absent sternum are limited to case reports, and no preferred method for management has been described. Herein, we describe the use of porcine acellular dermal matrix to reconstruct the sternum of an infant with sternal infection following attempted repair using synthetic mesh. The patient was a full-term male with trisomy 21, agenesis of corpus callosum, ventricular septal defect, patent ductus arteriosus, right-sided aortic arch, and congenital absence of sternum with no sternal bars. Following removal of the infected synthetic mesh, negative pressure wound therapy with instillation was used to manage the open wound and provide direct antibiotic therapy. When blood C-reactive protein levels declined to ${\leq}2mg/L$, the sternum was reconstructed using porcine acellular dermal matrix. At 21 months postoperative, the patient demonstrated no respiratory issues. Physical examination and computed tomography imaging identified good approximation of the clavicular heads and sternal cleft and forward curvature of the ribs. This case illustrates the benefits of negative pressure wound therapy and acellular dermal matrix for the reconstruction of absent sternum in the context of infected sternal surgical site previously repaired with synthetic mesh.

• 로봇학회논문지
• /
• 제19권2호
• /
• pp.188-195
• /
• 2024

This paper proposes a photorealistic real-time dense 3D mapping system that utilizes a neural network-based image enhancement method and mesh-based map representation. Due to the characteristics of the underwater environment, where problems such as hazing and low contrast occur, it is hard to apply conventional simultaneous localization and mapping (SLAM) methods. At the same time, the behavior of Autonomous Underwater Vehicle (AUV) is computationally constrained. In this paper, we utilize a neural network-based image enhancement method to improve pose estimation and mapping quality and apply a sliding window-based mesh expansion method to enable lightweight, fast, and photorealistic mapping. To validate our results, we utilize real-world and indoor synthetic datasets. We performed qualitative validation with the real-world dataset and quantitative validation by modeling images from the indoor synthetic dataset as underwater scenes.

• 항공우주시스템공학회지
• /
• 제17권4호
• /
• pp.1-9
• /
• 2023

최근 위성의 SAR(Synthetic Aperture Radar), 통신 및 신호 감시 임무가 고도화됨에 따라 경량화 및 전개 면적 대비 수납효율이 우수한 전개형 메쉬 안테나에 관한 연구가 활발히 수행되고 있다. 전개형 메쉬 안테나는 임무 주파수대역이 증가함에 따라 메쉬 제직 밀도의 척도인 OPI(Openings Per Inch)의 수가 증가하는 특징이 있으며, 이러한 OPI 변화는 메쉬의 광학물성 특성에 직접적인 영향을 미치므로 이에대한 연구가 필수적이다. 본 논문에서는 메쉬의 광학 물성치와 반사판에 대한 열적 관계를 검증하기 위해 기존 해외 연구사례를 바탕으로 메쉬의 다양한 광학적 특성에 따른 궤도 열해석 통해 메쉬와 안테나간의 열적 민감도 분석과 메쉬 반사판의 온도구배 영향성 분석을 수행하였다.

• 대한토목학회논문집
• /
• 제39권2호
• /
• pp.247-256
• /
• 2019

본 연구에서는 홍수모델링을 위해 삼각격자와 사각격자를 포함하는 혼합격자의 적용이 가능한 2차원 Godunov형 유한체적모형을 이용하여 격자형상과 해상도에 따른 홍수위, 홍수범람범위, 모형의 계산시간을 비교 분석하였다. 연구유역은 2000년 10월 29일부터 11월 19일까지 22일 동안 홍수가 발생한 영국의 Upton-upon Severn 유역이다. 홍수 모델링을 위해 고해상도 LiDAR (Light Detection And Ranging)를 이용하여 지형자료를 구축하였으며, 격자유형 및 해상도에 따른 2차원 홍수모델링 결과는 홍수기간 동안 촬영된 4개의 ASAR (Airborne Synthetic Aperture Radar) 영상자료와 비교하였다. 본 연구는 동일한 지형과 경계조건을 사용하더라도, 격자의 형상과 해상도에 따라 홍수위와 범람범위가 큰 차이를 가질 수 있음을 보여주었으며, 2차원 홍수모델링의 목적과 상황에 맞는 적절한 격자유형과 해상도의 선택이 필요함을 보여준다.

• 한국항행학회논문지
• /
• 제15권4호
• /
• pp.616-625
• /
• 2011

본 연구에서는 지형을 Rendering 기법의 대표적인 방법인 Geometry Clipmaps와 ROAM 2.0을 분석하여 Rendering 연산에 소요되는 연산을 CPU가 아닌 GPU에 중점을 두어 보다 빠르고 넓은 가시화 영역을 보장하는 확장된 Geometry Clipmaps 알고리즘을 제안한다. 확장된 알고리즘은 LOD(Level of Detail)을 통한 각 레벨의 Mesh 구성 방법, 레벨간의 연결망 Mesh 구성 방법, VFC(View Frustum Culling)을 사용하여 Rendering을 최적화 할 수 있는 Mesh Block화 방안 그리고 최대 1m 해상도를 갖는 고해상도 영상 Mapping 방안 등을 포함하고 있다.

• Nuclear Engineering and Technology
• /
• 제52권3호
• /
• pp.485-498
• /
• 2020

A diffusion synthetic acceleration (DSA) technique for the S_N transport equation discretized with the linear discontinuous expansion method with subcell balance (LDEM-SCB) on unstructured tetrahedral meshes is presented. The LDEM-SCB scheme solves the transport equation with the discrete ordinates method by using the subcell balances and linear discontinuous expansion of the flux. Discretized DSA equations are derived by consistently discretizing the continuous diffusion equation with the LDEM-SCB method, however, the discretized diffusion equations are not fully consistent with the discretized transport equations. In addition, a fine mesh rebalance (FMR) method is devised to accelerate the discretized diffusion equation coupled with the preconditioned conjugate gradient (CG) method. The DSA method is applied to various test problems to show its effectiveness in speeding up the iterative convergence of the transport equation. The results show that the DSA method gives small spectral radii for the tetrahedral meshes having various minimum aspect ratios even in highly scattering dominant mediums for the homogeneous test problems. The numerical tests for the homogeneous and heterogeneous problems show that DSA with FMR (with preconditioned CG) gives significantly higher speedups and robustness than the one with the Gauss-Seidel-like iteration.

• 한국원자력학회:학술대회논문집
• /
• 한국원자력학회 2001년도 춘계학술발표회요약집
• /
• pp.62-62
• /
• 2001