• Archives of Plastic Surgery
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• v.44 no.3
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• pp.234-237
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• 2017

Paraffinoma is a destructive complication of paraffin oil injection, usually associated with massive tissue destruction, thus requiring radical surgery and subsequent complex reconstruction. Although breast and penile paraffinomas have been widely described and their management is quite standardized, paraffinomas of the knee are still rare and only few case reports or small case series are available in the current literature. We describe the case of a 77-year-old man with a large paraffinoma of the right knee that occurred after self-injection of paraffin oil, 58 years before. He underwent wide surgical resection of the soft tissues overlying the knee and subsequent two-stage reconstruction by using acellular dermal matrix and, after 20 days, split-thickness skin grafts. Follow-up after 16 months showed no signs of skin ulcerations or inflammation, with an overall improvement in function. Even though conventional flap reconstructions may be still useful, the authors believe that acellular dermal matrices represent a safe, reliable, and less invasive alternative for challenging soft tissue reconstructions even in elderly patients with multiple medical problems.

• Journal of Computational Design and Engineering
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• v.3 no.3
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• pp.226-249
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• 2016

The symbiotic organisms search (SOS) algorithm is an effective metaheuristic developed in 2014, which mimics the symbiotic relationship among the living beings, such as mutualism, commensalism, and parasitism, to survive in the ecosystem. In this study, three modified versions of the SOS algorithm are proposed by introducing adaptive benefit factors in the basic SOS algorithm to improve its efficiency. The basic SOS algorithm only considers benefit factors, whereas the proposed variants of the SOS algorithm, consider effective combinations of adaptive benefit factors and benefit factors to study their competence to lay down a good balance between exploration and exploitation of the search space. The proposed algorithms are tested to suit its applications to the engineering structures subjected to dynamic excitation, which may lead to undesirable vibrations. Structure optimization problems become more challenging if the shape and size variables are taken into account along with the frequency. To check the feasibility and effectiveness of the proposed algorithms, six different planar and space trusses are subjected to experimental analysis. The results obtained using the proposed methods are compared with those obtained using other optimization methods well established in the literature. The results reveal that the adaptive SOS algorithm is more reliable and efficient than the basic SOS algorithm and other state-of-the-art algorithms.

• 한국전산유체공학회:학술대회논문집
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• 2009.11a
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• pp.164-169
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• 2009

Study on swimming of microorganisms like, sperm motility, cilia beating, bacterial flagellar propulsion has found immense significance in the field of biological fluiddynamics. Because of the complexity involved, it is challenging for the researchers to model such problems. Immersed boundary method has proved its efficacy in the field of biological fluiddynamics, The present work aims at performing a numerical study on the microorganism locomotion using the immersed boundary method proposed by Peskin[1]. A two-dimensional model of the microorganism is modeled as thin elastic filament described as a sine wave. The neutrally buoyant organism undergoing deformations is immersed in a viscous and incompressible fluid. The fluid quantities are described using Eulerian coordinates and the immersed body is represented by Lagrangian coordinates. The Eulerian and Lagrangian variables are connected by the Dirac delta function. The Navier-Stokes equations governing the fluid flow are solved using the fractional step method on a staggered Cartesian grid system. The developed numerical code in FORTRAN will be validated by comparing the numerical results with the available results.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05a
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• pp.29-44
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• 2002

Wetlands provide vital habitats for fish and wildlife while offering numerous other benefits. As in some other countries, however, Taiwan has witnessed the loss of a significant portion of its coastal wetlands due to large-scale reclamation projects along the coast. Most of the wetlands that still remain are seriously being threatened by both human activities and natural changes, such as drainage for agricultural production, filling for industrial development, discharge of wastes and drought. The administrative performance of the existing authorities and legislation in Taiwan has mostly been ineffective in protecting these precious, sensitive areas. This paper introduces the distribution of wetlands in Taiwan and highlights their invaluable functions and potential economic value. It also discussed the recent activities, both initiated by the government and the NGOs, to protect wetlands in Taiwan. Based on the above discussion, the paper identifies the wide-range of current problems related to their management and proposes the vision should have to save wetlands for the future. It argues that establishing clear policies and effective institutional mechanisms on wetland protection and conservation, classifying the wetlands for better management, and fully promoting public awareness and consciousness of the importance of the wetlands will not only be beneficial but will also address the urgent need to safeguard the wetlands in Taiwan. Additionally, the paper recognizes that international cooperation and collaboration on wetland restoration is essential and most challenging.

• The Korean Fashion and Textile Research Journal
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• v.21 no.6
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• pp.717-729
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• 2019

This study defines critical fashion designs and investigate its critical messages on fashion itself. The critical messages on fashion are categorized into two major issues of a fashion industry system and fashion consumer culture. This study contributes to the understanding of meaning and value for critical fashion messages that match critical art. As the research method, this study combines a literature review and case studies and the research scope focuses on cases that have appeared in fashion media since the 2000s when social critical messages in fashion began to emerge. The results of the study are as follows. Critical designers such as Viktor & Rolf, Elisa van Joolen, Issey Miyake, and Mary Ping have delivered messages challenging the nature of fashion industry system that criticize the cycle and limitation of a fashion system and pursues changes in perception of sustainability. The critical message on fashion consumer culture articulated by designers such as Alexander McQueen, Vivienne Westwood, Hussein Chalayan, and Ricarda Bigolin & Nella Themelios insist on the formation of community while delivering a critical message on social, political, and cultural problems that raise the mechanism of social awareness through fashion design.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.4
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• pp.1520-1542
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• 2020

Traditional software testing typically uses many physical resources to manually build various test environments, resulting in high resource costs and long test time due to limited resources, especially for small enterprises. Cloud computing can provide sufficient low-cost virtual resources to alleviate these problems through the virtualization of physical resources. However, the provision of various test environments and services for implementing software testing rapidly and conveniently based on cloud computing is challenging. This paper proposes a multilayer cloud testing model based on cloud computing and implements a hybrid cloud testing system based on virtual machines (VMs) and networks. This system realizes the automatic and rapid creation of test environments and the remote use of test tools and test services. We conduct experiments on this system and evaluate its applicability in terms of the VM provision time, VM performance and virtual network performance. The experimental results demonstrate that the performance of the VMs and virtual networks is satisfactory and that this system can improve the test efficiency and reduce test costs through rapid virtual resource provision and convenient test services.

• Archives of Reconstructive Microsurgery
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• v.8 no.1
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• pp.84-91
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• 1999

The female breast is a potent symbol of maternity, sexuality, and feminity. Unfortunately, the frequency of breast cancer and mastectomy are increasing in Korea, so the reconstruction of breast becomes a important surgical procedure. The purpose of this study is to analyze the results of breast reconstruction using free TRAM flap and to suggest the operative techniques for more successful results. This study is based on a series of 39 cases of breast reconstruction using free TRAM flap in mastectomized patients. Among these cases, 21 patients underwent immediate reconstruction and 18 patients underwent delayed reconstruction. 2 patients underwent immediate bilateral reconstruction. The postoperative courses of these cases are uneventful. Breast reconstruction following mastectomy is one of the most challenging problems in plastic surgery. Nowadays the free TRAM flap is accepted as an excellent method of autogenous tissue breast reconstruction. We conclude that this technique has advantages as follows. The free TRAM flap has not associated with the complications of implant-based reconstruction. It provides sufficient volume for ptotic and natural breast, easily concealed donor site, and secondary aesthetic benefit of abdominoplasty. Unlike conventional pedicled TRAM flap, it has superiority in blood supply, and can make liberal setting of flap and sparing of rectus muscle. So it can provide more satisfaction about the final result of breast reconstruction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.934-937
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• 2006

This investigation presents a topology formulation to design optimal poroelastic acoustic foams to maximize absorbing ability. For successful formulation, a single set of equations based on Biot's theory is adopted and an appropriate material interpolation strategy is newly developed. Because there was no earlier attempt to solve poroelastic acoustic foam design problems in topology optimization setting, many challenging issues including modeling and interpolation must be addressed. First, the simulation accuracy by a proposed unified model encompassing acoustic air and poroelastic material was checked against analytical and numerical results. Then a material interpolation scheme yielding a distinct acoustic air-poroelastic material distribution was developed. Using the proposed model and interpolation scheme, the topology optimization of a two-dimensional poroelastic acoustic foam for maximizing its absorption coefficient was carried out. Numerical results show that the absorption capacity of an optimized foam layout considerably increases in comparison with a nominal foam layout.

• Journal of Korea Multimedia Society
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• v.13 no.12
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• pp.1786-1797
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• 2010

Automatic understanding of contents in document image is a very hard problem due to involvement with mathematically challenging problems originated mainly from the over-determined system induced by document segmentation process. In both academic and industrial areas, there have been incessant and various efforts to improve core parts of content retrieval technologies by the means of separating out segmentation related issues using semi-structured document, e.g., invoice,. In this paper we proposed classification models for text lines on invoice document in which text lines were clustered into the five categories in accordance with their contents: purchase order header, invoice header, summary header, surcharge header, purchase items. Our investigation was concentrated on the performance of machine learning based models in aspect of linear-discriminant-analysis (LDA) and non-LDA (logic based). In the group of LDA, na$\"{\i}$ve baysian, k-nearest neighbor, and SVM were used, in the group of non LDA, decision tree, random forest, and boost were used. We described the details of feature vector construction and the selection processes of the model and the parameter including training and validation. We also presented the experimental results of comparison on training/classification error levels for the models employed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.10a
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• pp.99-102
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• 2000

In the supply chain network design, how to select the best location, capacity configuration of the suppliers and to assign manufacturers orders are a challenging issue. Especially when multi-tiers'suppliers are existed, the performance of supply chain is influenced by 2$\^$nd/ and 3$\^$rd/ suppliers. Supplier selection is multi-criteria problem which includes both qualitative and quantitative factors in supply chains. In order to select the best supplier it is necessary to make a trade off between these two factors such as cost, product quality, capacity, production lead time, deliver lead time and transportation lead tine of supplier constraints existed in multi-tiers supplier purchasing chain. In these circumstances, purchasing agents should decide two problems: which is the best supplier in each tier and how much should be purchased from each selected supplier. This research is intended to develop an integration of an analytical hierarchy process (AHP) and mathematical modeling proposed to consider two factors which may be conflicted in choosing the best supplier in each tier and placing the optimum order quantities to the supplier among multi-tiers suppliers.