• Proceedings of the KSME Conference
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• 2001.06a
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• pp.351-356
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• 2001

A potential loss of structural integrity due to aging of nuclear piping may have a significant effect on the safety of nuclear power plants. In particular, failures due to the erosion and corrosion defects are a major concern. As a result, there is a need to assess the remaining strength of pipe with erosion/corrosion defects. In this paper, a limit load solution for the eroded and corroded SA106 Grade B pipes subjected by internal pressure is developed. based in 3-D finite element analyses, considering a wide range of the shape of pipeline, flaw depth and axial flaw length parametrically.

• Steel and Composite Structures
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• v.28 no.1
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• pp.25-37
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• 2018

For the first time, the parametric instability characteristics of tow-steered variable stiffness composite laminated (VSCL) cylindrical panels is investigated using B-spline finite strip method (FSM). The panel is considered containing geometrical defects including cutout and delamination. The material properties are assumed to vary along the panel axial length of any lamina according to a linear fiber-orientation variation. A uniformly distributed inplane longitudinal loading varies harmoni-cally with time is considered. The instability load frequency regions corresponding to the assumed in-plane parametric load-ing is derived using the Bolotin's first order approximation through an energy approach. In order to demonstrate the capabili-ties of the developed formulation in predicting stability behavior of the thin-walled VSCL structures, some representative results are obtained and compared with those in the literature wherever available. It is shown that the B-spline FSM is a proper tool for extracting the stability boundaries of perforated delaminated VSCL panels.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.110-114
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• 2003

In this study is proposed the advanced elasto-plastic analytical method which can identify complex structural behaviors on the splice part of steel structures such as sliding and plastic contact problem between splice plates and blots. Compliated boundary conditions and various manufacturing defects are considered in various analytical cases. In the design or repair phase the plastic behavior and ultimate strength of splice parts should be very carefully verified to extend the service life of steel structures.

• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.637-640
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• 2009

A 13-year-old female 30 kg Korean Jin-do dog was presented with severe defects due to vasculitis and perivascular dermatitis at the left antebrachium area. A left superficial brachial axial pattern flap was elevated to cover the defect and the wound was covered. However, one week post surgery, the flap was survived about 1/3 of total flap length. Remaining two thirds defects were performed by the free skin mesh graft as an additional method. After ten days, the entire wound was achieved completely. Skin flaps carry own blood supply in other hands, the flap method is dependent upon continuation of adequate circulation until vascularization takes place. Because they are much thicker than other grafts, this is a slower process and the flap method is vulnerable to problems with kinking or tension of the base. According to this case, a practician has to consider length of flap and thickness in order to vascular perfusion when superficial brachial axial pattern flap is performed in a dog.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.1
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• pp.95-103
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• 2015

This paper presents the effects of the tool shape on the geometrical characteristics of flat end-milled side walls. A tool shape is characterized by such parameters as helix angle, number of cutting edges, and diameter. The geometrical characteristics of the side walls are represented by the surface profiles in the feed and axial directions, which are orthogonal to each other. The geometrical defects in each direction are estimated based on the instantaneous apparent cutting areas, which are represented by the interference area between the tool and workpiece and that between the cutting edge and workpiece. It is confirmed that a geometrical defect in the feed direction is formed when the tool leaves the workpiece and the curvature of the tool path changes. Defects in the axial direction are also found in the side walls, except for the defect zone in the feed direction. An up-cut using an end-mill with a steeper helix angle, a greater number of cutting edges, and a smaller diameter are thus found to improve the geometrical accuracy of end-milled side walls.

• Korean Journal of Head & Neck Oncology
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• v.1 no.1
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• pp.35-61
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• 1985

The surgical treatment of advanced carcinomas and some benign tumors having clinically malignant behaviors of the head and neck region often require extensive resection, necessitating large flaps for reconstruction. Since the original upper arm flap was described by Tagliacozzi in 1597, a variety of technique such as random pattern local flap, axial flap, distant flap, scalping flap, myocutaneous flap, free flap etc. have been proposed for reconstruction of head, face and neck defects. Reconstruction of the facial defects usually require the use of distant tissue. Traditionally, nasal reconstruction has been carried out with a variety of forehead flaps. In recent years, there has been more acceptance of immediate repairs following the removal of these tumors. As a result, patients are more willing to undergo these extensive resections to improve their chances of cure, with the reasonable expectation that an immediate reconstruction will provide an adequate cosmetic result. Authors experienced 13 cases of head and neck tumor during last three and half years that required wide excision and immediate reconstruction with various flaps, not with primary closure or simple skin graft. We present our experience with varied flaps for reconstruction after wide resection of head and neck tumors 3 cases of defect of dorsum of nose or medial canthus with island forehead flaps, lower eyelid defect with cheek flap, cheek defect with Limberg flap, orbital floor defect with Temporalis muscle flap, lateral neck defects with Pectoralis major myocutaneous flap or Latissimus dorsi myocutaneous free flap, subtotal nose defect with scalping flap, wide forehead defect with Dorsalis pedis free flap and 3 cases of mandibular defect or mandibular defect combined with lower lip defect were reconstructed with free vascularized iliac bone graft or free vascularized iliac bone graft concomitantly combined with free groin flap pedicled on deep circumflex iliac vessels We obtained satisfactory results coincided wi th goal of treatment of head and neck tumors, MAXIMAL CURE RATE with MINIMAL MORBIDITY, OPTIMAL FUNCTION, and an APPEARANCE as close to normal as possible.

• Journal of Korean Neurosurgical Society
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• v.52 no.6
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• pp.541-546
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• 2012

Objective : The prefabrication of customized cranioplastic implants has been introduced to overcome the difficulties of intra-operative implant molding. The authors present a new technique, which consists of the prefabrication of implant molds using three-dimensional (3D) printers and polymethyl-methacrylate (PMMA) casting. Methods : A total of 16 patients with large skull defects (>100 $cm^2$) underwent cranioplasty between November 2009 and April 2011. For unilateral cranial defects, 3D images of the skull were obtained from preoperative axial 1-mm spiral computed tomography (CT) scans. The image of the implant was generated by a digital subtraction mirror-imaging process using the normal side of the cranium as a model. For bilateral cranial defects, precraniectomy routine spiral CT scan data were merged with postcraniectomy 3D CT images following a smoothing process. Prefabrication of the mold was performed by the 3D printer. Intraoperatively, the PMMA implant was created with the prefabricated mold, and fit into the cranial defect. Results : The median operation time was $184.36{\pm}26.07$ minutes. Postoperative CT scans showed excellent restoration of the symmetrical contours and curvature of the cranium in all cases. The median follow-up period was 23 months (range, 14-28 months). Postoperative infection was developed in one case (6.2%) who had an open wound defect previously. Conclusion : Customized cranioplasty PMMA implants using 3D printer may be a useful technique for the reconstruction of various cranial defects.

• Archives of Reconstructive Microsurgery
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• v.25 no.2
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• pp.25-28
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• 2016

Purpose: Reconstruction of small defects of the dorsal fingers and toes is a challenging task. Although adipofascial flap is widely used for these areas, additional refinements are warranted. In this paper, we define the appropriate defect size in the finger and toes that can be treated with the adipofascial flap, refine its surgical indications and present a few surgical tips. Materials and Methods: Twelve patients with dorsal defects of the fingers and toes were treated with a random-type adipofascial turn-over flap and skin graft. If the defect area exceeded the size that could be covered by a conventional design, the flap base was designed in oblique or curvilinear fashion to lengthen the flap. For accurate defect coverage, the width of the flap base was designed in an asymmetrical shape depending on the defect configuration, varying the width from 0.3 to 1.0 cm, as opposed to the standard 0.5 to 1.0 cm width. Moreover, the lateral limit of the flap was defined as the lateral axial line. The size of the defect ranged from $3.0{\times}1.7cm$ to $1.5{\times}1.3cm$. Results: All flaps survived completely. Gliding function of the hand was well preserved and there was no evidence of tendon adhesion. Conclusion: The small defect in the dorsal finger and toe can be defined as less than one phalanx-length, measuring about $3.0{\times}2.0cm$ in size. If the defect exceeds this dimension, it is recommended that a different option be considered. We believe the adipofascial flap is an excellent option for treating small defects.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.6
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• pp.519-523
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• 2013

A steam generator (SG) tube is an important component of a nuclear power plant (NPP). It works as a pressure boundary between the primary and secondary systems. The integrity of a SG tube can be assessed by an eddy current test every outage. The eddy current technique(adopting a bobbin probe) is currently the main technique used to assess the integrity of the tubing of a steam generator. An eddy current signal analyst for steam generator tubes continuously analyzes data over a given period of time. However, there are possibilities that the analyst conducting the test may get tired and cause mistakes, such as: missing indications or not being able to separate a true defect signal from one that is more complicated. This error could lead to confusion and an improper interpretation of the signal analysis. In order to avoid these possibilities, many countries of opted for automated analyses. Axial ODSCC (outside diameter stress corrosion cracking) defects on the tubes of OPR1000 steam generators have been found on the tube that are in contract with tube support plates. In this study, automated analysis software called CDS (computer data screening) made by Zetec was used. This paper will discuss the results of introducing an automated analysis system for an axial ODSCC on the tubes of an OPR1000 steam generator.

• Biomedical Science Letters
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• v.21 no.1
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• pp.15-22
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• 2015

Dexamethasone, a synthetic glucocorticoid (GC), is clinically administered to woman at risk for premature labor to induce fetal lung maturation. However, exposure to repeated or excess GCs leads to intrauterine growth restriction (IUGR) and subsequently increases risk of psychiatric and cardio-metabolic diseases in later life through fetal programming mechanisms. GCs are key mediators of stress responses, therefore, maternal nutrient restriction or psychological stress during pregnancy also causes negative impacts on birth and neurodevelopment outcome of fetuses, and other congenital defects, such as craniofacial and skeletal abnormalities. In this study, to examine the effect of prenatal stress on fetal skeletal development, dexamethasone (1 mg/kg [DEX1] or 10 mg/kg [DEX10] maternal body weight per day) was administered intraperitoneally at gestational day 7.5~9.5 and the skeletons were prepared from embryos at day 18.5. Seven out of eighteen (39%) embryos treated with DEX10 showed axial skeletal abnormalities in either the T13 or L1 vertebrae. In addition, examination of the sternum revealed that xiphoid process, the protrusive triangular part of the lower end of the sternum, was bent more outward or inward in DEX group embryos. In conclusion, our findings suggest a possible link to the understanding of the effect of uterine environment to the fetal skeletal features.