• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.2
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• pp.31-39
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• 2011

Concrete-filled steel tube(CFT) columns have become popular for building construction due to not only composite effect of steel tube and infilled concrete, but also more economical. The purpose of this paper is to propose the applicable boundary formula of width-to-thickness ratio for rectangular steel tube as using CFT column. A parametric study was performed taking width-to-thickness ratio of rectangular steel tube and compressive strength of concrete as the main parameter. The strength of concrete are selected to 30, 60, 90MPa. The non-linear analysis was adopted in order to take into account the effect of concrete strength. Finally, from the test and analysis results, the effect of increasing strength according to concrete strength and width-to-thickness of steel tube and plastic behavior of specimens were verified distinctly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.12
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• pp.2011-2018
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• 2003

To analyze the bending collapse behavior of an aluminum square tube beam under a bending load, a finite element simulation for the four-point bending test has been performed. Using an aluminum tube beam specimen partly inserted with two steel bars, the local buckling deformation near the center of the tube beam was induced. The maximum bending load and the bending collapse behavior obtained from the numerical simulation were in good agreement with experimental results. Using a combination of the four-point bending test and its finite element simulation, analysis of the local buckling and the accompanied bending collapse behavior of aluminum tube beam could be quantitative accomplished.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.110-113
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• 2004

Aluminum and CFRP tube is light-weight material representatively but collapse mechanism is different under axial loading. Aluminum tube absorbs energy by stable plastic deformation under axialloading. While CFRP(Carbon Fiber Reinforced Plastics)tube absorb synergy by unstable brittle failure but its specific strength and stiffness is higher than that of aluminum tube. In this study, for complement of detect and synergy effect by combination with the advantages of each member, the axialcollapsetests were performed for combined aluminum CFRP tubes which are composed of aluminum tubes wrapped with CFRP out side aluminum square tubes. Collapsecharacteristics were analyzed for combined square tubes which have different CFRP orientation angle and thickness. Test results were compared with that of aluminum tubes and CFRP tubes.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.149-152
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• 2000

By using a three-dimensional finite element program HydroFORM-3D based on a rigid-plastic model, the hydroforming process for automobile subfrmae is analyzed in this study. The goal of this study is to accomplish preform design and determine the level of internal pressure for producing final hydroformed subframe component. Prior to hydroforming, the initial tube blank must be bent to the approximate centerline of the final part to enable the tube to be placed in the die cavity, After then, a preforming operation like stamping is carried out to the prebent tube. Finally, hydroforming process is performed to the preformed tube to get the final production. And through ductile fracture theory, the failure, bursting, is predicted during hydroforming process for tube blank with different diameter.

• 연구논문집
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• s.30
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• pp.121-128
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• 2000

The failed tube received for this study has been used for approximately 10 year at $330^{\circ}C$ in a steam production boiler tube was fractured in the transversed direction to tube length, and fracture mode was typically intergranulas type without the plastic deformation. The fracture surface was covered by the oxide scale formed from the intermal high pressure steam at high temperature. The microstructure was not nearly thermal-degraded during the service. From this result, we can conclude that the oxide film was proferentialy formed into the grainboundary and this grainboundary oxide film was brittle-fractured by the thermal stress in the longitudinal direction to the tube brittle intergranular fracture mode.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2006.03a
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• pp.191-197
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• 2006

In this paper 35- and 72-story tube system and trussed tube system were designed and their seismic performances were evaluated by nonlinear static analysis. According to the analysis results, the tube system structures retained high stiffness and strength; however they showed brittle failure mode due to the yielding of columns. In the case of trussed tube system, columns in the side-side buckled first followed by the buckling of the braces. When buckling-restrained braces were applied, plastic hinges formed in the lower stories gradually spreads to the higher stories, resulting in ductile behavior.

• Archives of Plastic Surgery
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• v.40 no.4
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• pp.445-449
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• 2013

Retrobulbar hemorrhage, especially when associated with visual loss, is a rare but significant complication after facial bone reconstruction. In this article, two cases of retrobulbar hematoma after surgical repair of blow-out fracture are reported. In one patient, permanent loss of vision was involved, but with the other patient, we were able to prevent this by performing immediate decompression after definite diagnosis. We present our clinical experience with regard to the treatment process and method for prevention of retrobulbar hematoma using a scalp vein set tube and a negative pressure drainage system.

• Archives of Reconstructive Microsurgery
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• v.11 no.2
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• pp.146-152
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• 2002

As the defects of the penis caused by trauma, surgical amputation, or congenital abnormality give the patients both psychological trauma and functional impairment, reconstruction of the penis is mandatory. Radial forearm free flap is reliable one-stage procedure, which can reconstruct both the phallus and the urethra. Chang and Whang's adaptation of the "tube-in-a-tube" concept and its incorporation into a free flap design represented a major advance in microsurgical phallic construction. Biemer described a modification of the radial forearm flap design in which the neourethra was centered over the radial artery, but the phallic shaft was separated into two paraurethral swatches. The authors have performed one-stage penile reconstruction in two patients since 1998, using a radial forearm free flap. Our present design incorporates the original Biemer triple skin island and includes a fourth distal island for neoglans. One case was the amputation of the penis from felonious assault and the other case was the iatrogenic penile amputation from repetitive urologic surgery for congenital hypospadia. All patients showed aesthetically acceptable results and good tactile sensory recovery. Severe complications such as necrosis, fistula, or urethral stricture were not occurred. Biemer's method modified by the authors is reliable one-stage penile reconstruction providing good aesthetic and functional results.

• Archives of Plastic Surgery
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• v.44 no.6
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• pp.530-538
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• 2017

Background A pharyngocutaneous fistula is a common and difficult-to-manage complication after head and neck reconstruction. It can lead to serious complications such as flap failure, carotid artery rupture, and pharyngeal stricture, and may require additional surgery. Previous radiotherapy, a low serum albumin level, and a higher T stage have been proposed as contributing factors. We aimed to clarify the risk factors for pharyngocutaneous fistula in patients who underwent flap reconstruction and to describe our experiences in treating pharyngocutaneous fistula. Methods Squamous cell carcinoma cases that underwent flap reconstruction after cancer resection from 1995 to 2013 were analyzed retrospectively. We investigated several significant clinical risk factors. The treatment modality was selected according to the size of the fistula and the state of the surrounding tissue, with options including conservative management, direct closure, flap surgery, and pharyngostoma formation. Results A total of 127 cases (18 with fistulae) were analyzed. A higher T stage (P=0.048) and tube-type reconstruction (P=0.007) increased fistula incidence; other factors did not show statistical significance (P>0.05). Two cases were treated with conservative management, 1 case with direct closure, 4 cases with immediate reconstruction using a pectoralis major musculocutaneous flap, and 11 cases with direct closure (4 cases) or additional flap surgery (7 cases) after pharyngostoma formation. Conclusions Pharyngocutaneous fistula requires global management from prevention to treatment. In cases of advanced-stage cancer and tube-type reconstruction, a more cautious approach should be employed. Once it occurs, an accurate diagnosis of the fistula and a thorough assessment of the surrounding tissue are necessary, and aggressive treatment should be implemented in order to ensure satisfactory long-term results.

• Design & Manufacturing
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• v.1 no.1
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• pp.1-5
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• 2007

Double injection molding process is very efficient molding-method for molding the products which is consist of multi-materials. Fuel-tube holder which is necessary for automobil power train and circulation systems is composed of plastic and rubber materials to minimize the vibration and pulsation noises. In existing process, fuel-tube holder was made by the insert molding process or assembly process after molding. If fuel-tube holder is manufactured by double injection molding process, it may be realize to improve the product quality, efficiency of molding-process and retrenchment of manufacturing cost. In this study, for manufacturing fuel-tube holder by double injection molding process, the analysis of joining characteristics between PA6(polyamide 6) and TPE(thermoplastic elastomer) was executed and the double injectin mold for molding fuel-tube holder with core toggle mechanism was fabricated. Finally, fuel-tube holder was molding using fabricated double injection mold.