• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.94-97
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• 2009

Cast defect in large steel ingots are estimated in quality and compared each other cast conditions on simulation results by now. The cast defects, micro-crack, shrinkage, pin hole which are predictable in simulation with a reasonable accuracy. In this study, 15 ton steel ingot casting was simulated for solidification model and cast defect prediction. And the real cast was carried out in a foundry for the compeer to the simulation results, the cast defect prediction. Also, the quantity of predicted defect was tried to measuring with the defect mach counting for the various simulated cast conditions. The defect quantity work was used to find the optimized cast condition in DOE(design of experiment) procedure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.17-20
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• 1998

Thermal behavior of Flow Pattern Defect (FPD) and Large Pit (LP) in Czochralski Silicon crystals was investigated by applying high temperature ($\geq$1100$^{\circ}C$) annealing and non-agitation Secco etching. For evaluation of the effect of LP upon device performance / yield, DRAM and ASIC devices were fabricated. The results indicate that high temperature annealing generates LPs whereas it decreases FPD density drastically, and LP does not have detrimental effects on the performance /

• Journal of Korean Foot and Ankle Society
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• v.18 no.2
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• pp.76-79
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• 2014

In treatment of failure in ankle joint replacement therapy, talar avascular necrosis with massive bone defect, talus fracture with severe comminution and bone defect and ankle dislocation, treatment of large bone defects is considerably important for ankle joint stability and union, therefore, the choice of treatment for large bone defects is use of femoral head or iliac crest bone graft and rigid internal fixation. Because first generation total ankle arthroplasty performed for the first time using a cemented fixation technique requires a large amount of bone resection during re-surgery and there is some possibility of a larger bone defect after removal of implants, in cases where prosthesis for the defect is needed, performance of palliative femoral head or iliac crest bone graft and rigid internal fixation can be difficult. We report on a case of a 48-year-old woman who had experienced ankle pain for 25 years since undergoing total ankle arthroplasty. Because the patient had little ankle motion and rigid soft tissue despite a large bone defect caused by aseptic loosening, a good outcome was obtained only for the femoral cancellous bone graft using allo femoral head without internal fixation.

• Journal of Korean Neurosurgical Society
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• v.44 no.4
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• pp.211-216
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• 2008

Objective : The cranioplasty and ventriculoperitoneal (VP) shunt operation have been used to treat a large cranial defect with posttraumatic hydrocephalus (PTH). The aim of this study was to evlauate the difference of outcomes between in the shunting after the cranioplasty (group 1) and the cranioplasty after the shunting (group 2) in a large flaccid cranial defect with PTH. Methods : In this study, a retrospective review was done on 23 patients undergoing the cranioplasty and VP shunt operation after the decompressive craniectomy for a refractory intracranial hypertension from 2002 to 2005. All of 23 cases had a large flaccid concave cranial defect and PTH. Ten cases belong to group 1 and 13 cases to group 2. The outcomes after operations were compared in two groups 6 months later. Results : The improvement of Glasgow outcome scale (GOS) was seen in 8 cases (80.0%) of total 10 cases in group 1, and 6 cases (46.2%) of 13 cases in group 2. Three (75.0%) of 4 cases with hemiparesis in group 1 and 3 of 6 cases (50.0%) in group 2 were improved. All cases (2 cases) with decrease of visual acuity were improved in each group. Dysphasia was improved in 3 of 5 cases (60%) in group 1 and 4 of 6 cases (66.6%) in group 2. Conclusion : These results suggest that outcomes in group 1 may be better than in group 2 for a large flaccid concave cranial defect with PTH.

• Archives of Reconstructive Microsurgery
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• v.14 no.1
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• pp.50-56
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• 2005

There are limited treatment options in the reconstruction of the very large defect in the metaphyseal portion of distal femur and proximal tibia. Fibula is one of the most popular donor of the long bone reconstruction in reconstructive microsurgical field. It has many advantages such as very strong strut tubular bone, very reliable vascular anatomy with large vascular diameter and long pedicle. There are limited donor site problems such as transient peroneal nerve dysfunction. In those situations with the huge long bone defects in distal femur or proximal tibia, the defective bony shape and strength of the transplanted fibular bone is not enough if only one strut of the fibula is transferred. We performed 7 cases of "doule barrel" fibular transplantation on the metaphyseal portion of distal femur and proximal tibial large defects in which it is very difficult to fill the bony gap with conventional bone graft or callotasis methods. It takes averaged 8.3 months since that procedure to obtain bony union. After solid union of the transferred double barrelled fibular graft. There were no stress fracture in our series. So we can propose double barrel fibular graft is useful method in those cases with very large bone defect on the metaphysis of large long bone.

• Korean Journal of Materials Research
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• v.11 no.9
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• pp.781-785
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• 2001

The thermal behavior of Flow Pattern Defect (FPD) and Large Pit (LP) in Czochralski Silicon crystal was investigated by applying high temperature annealing ($\geq$$1100^{\circ}C$) and non-agitated Secco etching. For evaluation of the effect of LP upon device performance/yield, commercial DRAM and ASIC devices were fabricated. The results indicated that high temperature annealing generates LPs whereas it decreases FPD density drastically. However, the origins of FPD and LP seemed to be quite different by not showing any correspondence to their density and the location of LP generation and FPD extinction. By not showing any difference between the performance/yield of devices whose design rule is larger than 0.35 $\mu\textrm{m}$, LP seemed not to have detrimental effects on the performance/yield.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.454-458
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• 2010

Velopharyngeal insufficiency is defined as a status in which nasal cavity and oral cavity can not be sepa-rated when speaking, swallowing by any reason. It has been treated by palatorrhaphy, pharyn-geal flap, local flap, free flap etc. When the size of the defect is small, it can be restored by palatorrhaphy, pharyngeal flap etc. But they are not proper for treatment of the large size of defect. In that case, local flap and free flap are more beneficial. Although large defect can be restored by free flap technique, but it is very complex, time-consuming and may bring about esthetical, functional complications of donor site. Buccinator myomucosal flap is a kind of local flap and reported for the first time by Bozola et al in 1989 and it has become a useful way for reconstruction of large intraoral defect. Authors experienced the use of buccinators myomucosal flap for treating secondary velopharyngeal insufficiency with large soft palate defect and obtained good result. So we report the case with literature reviews.

• Archives of Reconstructive Microsurgery
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• v.22 no.2
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• pp.57-62
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• 2013

Purpose: The aim of this study is to report on the results and discuss the role of free flap followed by ipsilateral vascularized fibular transposition (IVFT) for reconstruction of large bone and soft tissue defect combined with infection by open tibia fracture. Materials and Methods: During the research period, lasting from December 2002 to June 2008 (Kyung Hee University Medical Center), data were collected from three patients who underwent IVFT after free flap. We analyzed the successiveness and persistency of the infection using free flapping, bone union, and hypertrophy between transposed fibula and tibia. Results: Regarding free flap, successive results were observed in all examples. In the final follow-up results, transposed fibulas all survived, having hypertrophy similar to that of adjacent tibia. Conclusion: Reconstruction of tibia defect with free flap followed by IVTF is a useful and safe method for avoidance of the potential risk of infection for patients with a large tibial bone defect and soft tissue defect associated with infection.

• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.81-84
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• 2008

Purpose: The goals of cranioplasty are to protect the brain from trauma and restore normal cranial contour with as few complication as possible. In patient who suffered from cranial defect, the most satisfactory form of cranioplasty may be archived with autogenous bone grafts. We report on the treatment of large frontal bone defect using pericranial flap and split-rib graft. Methods: A 29-year-old male was referred to our department. He was involved in an automobile accident resulting in large frontal bone and sinus defect and skull basal defect. The reconstruction was undertaken using galeal frontalis myofascial flap and split-rib cranioplasty using bicoronal incision. Results: The postoperative course was successful. For 9 months follow up period, there was no complication about hematoma, infection, CSF leakage and washboard deformity. He was pleased with the results even when absolute symmetry was not achieved. Conclusion: We experienced large frontal bone and sinus defect and skull basal defect patient and successfully treated with split-rib graft and galeal frontalis myofascial flap.

• Archives of Plastic Surgery
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• v.34 no.5
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• pp.667-670
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• 2007

Purpose: Among the materials for cranioplasty, autogenous bone is ideal because it is less susceptible to infection and has lower rates of subsequent exposure. However, the procedure is technically demanding to perform and requires a donor site. Disadvantages further exist when the defect is large and there are attendant limitations in donor site. The authors present their experience with reconstruction of large skull defect using right-angled zigzag osteotomized outer table of autogenous calvarial bone, overcoming the limitation in donor site. Methods: From 2000 to 2006, 9 patients were retrospectively reviewed, who had undergone reconstruction with right angled zigzag osteotomized outer table of autogenous calvarial bone. Results: Aesthetically satisfactory skull shape was achieved. Major complications of infection, hematoma, plate exposure, and donor site complications of dural tear with bleeding, cerebrospinal fluid leak, and meningitis were not seen. One patient had delayed wound healing and was successfully managed conservatively. Conclusion: Autogenous bone is the material of choice for cranioplasty, especially in complicated cases. Right angled zigzag osteotomy is a useful method in reconstruction of large skull defects with less donor site morbidity.