• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 추계학술대회논문집
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• pp.233-236
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• 2003

A bumper comprises a bumper face, a bumper beam for distributing the load from the impacts applied to the bumper face and reinforcing the bumper, an absorber member interposed between the bumper face and the bumper beam, and a pair of bumper stays which secure the bumper beam to the vehicle body. A conventional bumper stay structure is assembled into several stamped parts, so several processes are needed and the structure is complicated. In this study the bumper stay is applied to the tubular hydroforming which is known to have several advantages such as the reduction of the number of the process and the part weight. The thickness distribution of the tube after hydroforming and the internal energy at the event of the a compression are mainly considered to evaluate the hydro-formability and energy absorption performance.

• Wind and Structures
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• 제21권6호
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• pp.709-726
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• 2015

In this study, a novel vision-based bolt-loosening monitoring technique is proposed for bolted joints connecting tubular steel segments of the wind turbine tower (WTT) structure. Firstly, a bolt-loosening detection algorithm based on image processing techniques is developed. The algorithm consists of five steps: image acquisition, segmentation of each nut, line detection of each nut, nut angle estimation, and bolt-loosening detection. Secondly, experimental tests are conducted on a lab-scale bolted joint model under various bolt-loosening scenarios. The bolted joint model, which is consisted of a ring flange and 32 sets of bolt and nut, is used for simulating the real bolted joint connecting steel tower segments in the WTT. Finally, the feasibility of the proposed vision-based technique is evaluated by bolt-loosening monitoring in the lab-scale bolted joint model.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 춘계학술대회 논문집
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• pp.202-205
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• 2004

A bumper comprises a bumper face, a bumper beam for distributing the load from the impacts applied to the bumper face and reinforcing the bumper, an absorber member interposed between the bumper face and the bumper beam, and a pair of bumper stays which secure the bumper beam to the vehicle body. A conventional bumper stay structure is assembled into several stamped parts, so several processes are needed and the structure is complicated. In this study the bumper stay is applied to the tubular hydroforming which is known to have several advantages such as the reduction of the number of the process and the part weight. The thickness distribution of the tube is mainly considered to evaluate the hydro-formability and the shape of the tube is determined.

• Journal of the Optical Society of Korea
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• 제13권2호
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• pp.256-260
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• 2009

The optical performance of the reflective polarizer was investigated over three kinds of direct-lit backlights and/or different configurations of the optical sheets. The optical gain factor achieved by using the reflective polarizer increased as the diffuse nature of the optical sheet was enhanced, because of the more efficient polarization conversion. In addition, the gain factor decreased substantially in flat-lamp backlights compared to tubular-lamp backlights, which was ascribed to the high loss factor during the polarization recycling process due to the complex structure and large area of flat lamps. All these results suggested that reducing the loss factor of the backlight is very important for efficient polarization conversion and thus high optical gain of the reflective polarizer.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 추계학술대회논문집
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• pp.27-31
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• 2004

A bumper comprises a bumper face, a bumper beam for distributing the load from the impacts applied to the bumper face and reinforcing the bumper, an absorber member interposed between the bumper face and the bumper beam, and a pair of bumper stays which secure the bumper beam to the vehicle body. A conventional bumper stay structure is assembled into several stamped parts, so several processes are needed and the structure is complicated. In this study the bumper stay is applied to the tubular hydroforming which is known to have several advantages such as the reduction of the number of the process and the part weight. The thickness distribution of the tube is mainly considered to evaluate the hydro-formability and the shape of the tube is determined.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.38-42
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• 2005

A bumper comprises a bumper cover, a bumper beam for distributing the load from the impacts applied to the bumper cover and reinforcing the bumper, an absorber member interposed between the bumper cover and tile bumper beam, and a pair of bumper stays which secure the bumper beam to the vehicle body. A conventional bumper stay structure is assembled into several stamped parts, so several processes are needed and the structure is complicated. In this study the bumper stay is applied to the tubular hydroforming which is known to have several advantages such as the reduction of the number of the process and the part weight. The thickness distribution of the tube is mainly considered to evaluate the hydro-formability and the shape of the tube is determined.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.39.1-39.1
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• 2011

Due to less turbulence and no land limitation, offshore wind energy gets more attention than onshore. Jacket structure is regarded as a suitable solution for the water depth ranging from 30 to 80 meters. In general, joint stress concentration of jacket support structures affects their fatigue life. Nowadays, most jacket structures for offshore wind turbines have tubular X-joint between legs. In this paper, a study on X-joint stress concentration of offshore wind turbine jacket structure is performed by using 50m water depth model. Stress of X-joint on offshore environmental conditions are discussed.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1815-1818
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• 2006

Imogolite which has chemical composition, $(HO)_3Al_2O_3SiOH$, was synthesized with orthosilicate acid and aluminium chloride at low pH solution. It has extremely large aspect ratio with an external diameter of 2nm and the length of a few micrometers. The high aspect ratio of the imogolite could make the material as the filler for the high strength fiber and as the wire for the electronic applications. Here, Imogolite that derives considerable microporosity from a nanometer-sized tubular structure has been modified with a conducting polymer, polypyrrole. Its bonding and wiring structure were confirmed by IR and TEM. The measured conductivity after modification with polypyrrole increased with polypyrrole thickness at various voltage conditions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권3호
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• pp.245-249
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• 2008

Epidermal growth factor is a single-chain polypeptide consisting of 53 amino acids and has a potent mitogenic activity that stimulates proliferation of various normal and neoplastic cells through the interaction with its specific receptor(epidermal growth factor receptor, EGFR). Pleomorphic adenoma is the most common salivary benign tumor and histologically, it contains the epithelial cell, the myo-epithelial cell and mesenchymal ingredient, which is various aspect. Adenoid cystic carcinoma is an infiltrative malignant salivary gland tumor with three different histological patterns: cribriform, tubular or solid. The tumor cell structure composed of modified myoepithelial cell, and basaloid cell. In this study, we used an immunohistochemical technique to investigate the expression of EGF in 6 specimens of adenoid cystic carcinoma and 10 specimens of pleomorphic adenoma taken from patients treated at Dept. of Oral and Maxillofacial Surgery, Dankook University. The results were as follows. 1. In pleomorphic adenoma, ductal structure and scattered spindle cells in hyalinized stroma, disclosing myxoid stroma and hyalin, cartilage formation were observed. Immunohistologically, weak EGF expression in ductal structure and negative in stromal area were observed. 2. Cribriform type of adenoid cystic carcinoma showed numerous pseudocyst surrounded by dark small neoplastic cells in the back-ground of fibrous connective tissue and moderate EGF expression of dark cells adjacent to pseudo lumen in cribriform pattern, while weak expression in other most cells. 3. Tubular type of adenoid cystic carcinoma showed numerous ductal pattern surrounded by two layered neoplastic cells in the back-ground of fibrous connective tissue and strong EGF expression in luminal cells of ductal structure, while weak expression in outer cells. From the results obtained, we suggest that EGF is mainly biosynthesized in cells forming duct like structures of tubulo-ductal type or cribriform adenoid cystic carcinoma and it may play a role, as a cell mitogen in adenoid cystic carcinoma growth.

• 패션비즈니스
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• 제18권2호
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• pp.148-165
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• 2014

The purpose of this study is to establish a theory about the necessary structure for knitwear design, and to propose it with the practical data through the actual development of a high value added knit structure. For this study, the market was conducted along with literature reviews on the existing studies and the relevant books about knit structures. The market research aimed at the products released in the spring/summer and fall/winter seasons of 2012-2013, focusing on brand for middle aged women. The utilization of the structure by item and the characteristics of knit design were studied. The research was conducted on S/S products in May and July, and F/W products in October and December. As a result of the market research, it was shown that the lightweight structures with permeability such as plain, lace, links and links, this is repeated and rib structure were frequently utilized during the S/S season, while double structures with good shape stability were greatly utilized during the F/W season. Also, during the F/W season, a cable structure and tubular jacquard that emphasized the volume or cubic effect were frequently used, and there were many jacquard structures where a change of color sense and motive were added. Concerning the knit structures development, the researcher designed the knit structure at the actual production site of the knit fashion. A total of 5 pieces of knit structures were developed by asking a professional for programming and knitting. To the developed structures, the study added a multi-gauged effect, herringbone transformation effect, 3-dimensional surface effect, color effects, geometric patterns, lace penetration effect, and soft surface effect in a water-drop shape. In addition, the structures had differences in the added values by mixing various structures and diversely expressing color sense on the knitting line. This study proposes the direction for 21st century knitwear product design, through the development of a high value added knit structure.