• Journal of the Korean Society for Nondestructive Testing
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• v.16 no.3
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• pp.162-173
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• 1996

Dry magnetic particle inspection(MPI) was performed to detect the surface defects of steel ingot cast billets. Magnetic properties of several materials were characterized by the measurement of the B-H hysteresis curve. The inspection results were evaluated in terms of the magnetizing current, temperature, and the amount of magnetic particles applied to billets. Magnetic flux leakage near the defect site of interest was measured and compared with the results of calculation by the finite element method in the case of direct magnetizing current. Direct and alternating magnetizing currents for materials were deduced by the comparison of the inspections. Results of the magnetic particle inspection by direct magnetizing current were compared with those of finite element method calculations, which were verified by measuring magnetic leakage flux above the surface and the surface defects of the material. For square rods, due to the geometrical effect, the magnetic flux density at the edges along the length of the rods was about 30% of that at the center of rod face for a sufficiently large direct magnetizing current, while it was about 70% for an alternating magnetizing current. Thus, an alternating magnetizing current generates rather uniform magnetic flux density over the rods, except for the region on the face across about 10 mm from the edge. The attraction of the magnetic particle by the magnetic leakage field was nearly independent of the surface temperature of the billets up to $150^{\circ}C$. However, the temperature should have been limited below $60^{\circ}C$ for an effective fixing of gathered magnetic particles to the billet surface using methylene chloride. We also found that the amount of applied magnetic particles tremendously affected the detection capability.

• Archives of Craniofacial Surgery
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• v.18 no.4
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• pp.255-260
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• 2017

Background: Surgery for reconstruction of defects after surgery should be performed selectively and the many points must be considered. The authors conducted this study to compare the local flap and skin graft by facial location in the reconstruction after resection of facial skin cancer. Methods: The authors performed the study in patients that had received treatment in Department of Plastic Surgery, Gyeongsang National University. The cases were analyzed according to the reconstruction methods for the defects after surgery, sex, age, tumor site, and tumor size. Additionally, the authors compared differences of aesthetic satisfaction (out of 5 points) of patients in the local flap and skin graft by facial location after resection of facial skin cancer by dividing the face into eight areas. Results: A total of 153 cases were confirmed. The most common facial skin cancer was basal cell carcinoma (56.8%, 87 cases), followed by squamous cell carcinoma (37.2%, 57 cases) and bowen's disease (5.8%, 9 cases). The most common reconstruction method was local flap 119 cases (77.7%), followed by skin graft 34 cases (22.3%). 86 patients answered the questionnaire and mean satisfaction of the local flap and skin graft were 4.3 and 3.5 (p=0.04), respectively, indicating that satisfaction of local flap was significantly high. Conclusion: When comparing satisfaction of patients according to results, local flap shows excellent effects in functional and cosmetic aspects would be able to provide excellent results rather than using a skin graft with poor touch and tone compared to the surrounding normal skin.

• Archives of Plastic Surgery
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• v.43 no.3
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• pp.265-271
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• 2016

Background Reconstruction of orofacial soft tissue defects is often challenging due to functional and aesthetic demands. Despite advances in orofacial soft tissue defect reconstruction using free flaps, locoregional flaps still remain an important option, especially in health resource-depleted environments. This retrospective study highlights our experiences in oral and maxillofacial soft tissue reconstruction using locoregional flaps. Methods A twenty-three years retrospective analysis of all patients managed in our department was undertaken. Information was sourced from patients' case notes and operating theater records. Data was analyzed using SPSS ver. 16 (SPSS Inc.) and Microsoft Excel 2007 (Microsoft). Results A total of 77 patients underwent orofacial soft tissue defect reconstruction within the years reviewed. Males accounted for 55 (71.4%) cases and trauma was the main etiological factor in 45 (58.4%) of the patients treated. When sites of defect were considered, the lip, 27 (32.1%), was the most frequent site followed by the nose, 17 (20.2%). Forehead flap, 51 (59.3%), was the most commonly used flap. Complications noted were tumor recurrences at the recipient bed in 3 (3.9%) cases, tumor occurrence at the donor site in 1 (1.3%) case and postoperative infection in 11 (14.3%) cases. Conclusions Locoregional flaps still have an important role in the rehabilitation of patients with orofacial soft tissue defects. They remain a vital tool in the armamentarium of the reconstructive surgeon, especially in health resource-depleted environments where advanced reconstructive techniques may not be feasible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.3
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• pp.713-719
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• 2000

In order to Prepare the$Ge_xSi_{1-x}/Si$(111) heterosructure by solid phase epitaxy (SPE), about 1000A of Au and about 1000A Ge were sequentially deposited on the Si(111) substrate. The resulting Ge/Au/Si(111) samples were isochronically annealed in the high vacuum condition. The behaviors of Au and Ge during thermal annealing and the structural Properties of $Ge_xSi_{1-x}$ films were characterized by Auger electron spectroscopy (AES), X-ray diffraction (XRD) and high resolution transmission electron microscopy (TEM). The a-Ge/Au/Si(111) structure was converted to the Au/GeSi/Si(111) structure. Defects such as stacking faults, point defects and dislocations were found at the GeXSil-X(111) interface, but the film was grown epitaxially with the matching face relationship of $Ge_xSi_{1-x}/$(111)/Si(111). Twin crystals were also found in the $Ge_xSi_{1-x}/$(111) matrix.

• Archives of Reconstructive Microsurgery
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• v.17 no.2
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• pp.87-93
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• 2008

Purpose: Because of good blood supply of the pedicled perforator flap and its advantage of not requiring vessel anastomosis compared to pedicled flap, it is widely used recently. The authors intended to report the results of various pedicled perforator flaps which have been performed to reconstruct the soft tissue defects and the utility of the flap. Methods: The study was conducted for 12 cases of pedicled perforator flap which were performed at the plastic surgery department of the current hospital from the period of June, 2005 to August, 2008. Four patients were male and eight patients were female and their age was ranged from 22 to 74 years old with mean age of 42.6 years old. The sites were 1 case on face, 3 cases on chest, 3 cases on back, 4 cases on coccyx, and 1 case on foot. Results: The defect sites of all patients were successfully reconstructed by using the pedicled perforator flap. Although most of the flaps revealed congestion at the early stage after the surgery, they were recuperated within few days. One case of skin flap was reported to be partially necrotized in old age woman who has no reliable perforator. Other than that, all defects were covered successfully and acceptable aethetically. Conclusion: As stated in above, the pedicled perforator flap has many useful advantages than the conventional pedicled flap and various free flap. Unless free flap must be required, the use of pedicled perforator flap is recommended by first choice for soft tissue coverage.

• Archives of Reconstructive Microsurgery
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• v.24 no.1
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• pp.7-12
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• 2015

Purpose: The rectus abdominis musculocutaneous (RAM) flap has contributed to the efficient reconstruction of soft tissue defects. The flap has the advantage of easy dissection, minimal donor site morbidity, and the constant vascular anatomy with long pedicle. Authors used the free RAM flap to reconstruct multi-located soft tissue defects while still considering functionality and aesthetics. We present the long-term outcomes and versatility of free RAM flaps. Materials and Methods: From 1994 to 2004, all patients who underwent soft tissue reconstruction with free RAM flap were reviewed retrospectively. The site of the reconstruction, vessels of anastomosis, type of RAM flap, and outcomes, including flap success rate, hospital stay after flap transfer, conduction of secondary procedure, flap complications, and donor-site complications were analyzed. Results: Twenty-one patients underwent 24 free RAM flaps in site of breast, face, upper extremity and lower extremity. Mean follow-up period was 36.1 months (range, 3~156 months). The overall success rate was 92% with only a loss of 2 flaps. Minor complications related to transferred flaps were necrosis of 2 partial flaps, hematoma formation in 3 cases, and a wound infection in 1 case. Donor site morbidity was not observed. Debulking surgery was performed in 4 patients, and scar revision was performed in 3 patients. Conclusion: Free RAM flap is a workhorse flap for general soft-tissue reconstruction with minimal donor site morbidity with aesthetically good results. Thus, the free RAM flaps are versatile, and sturdy for any sites of soft-tissue where reconstruction could be performed.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.12 no.2
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• pp.92-95
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• 2016

Beckwith-Wiedemann syndrome comprises multiple congenital anomalies with a risk of development of childhood tumors. Macroglossia is the predominent finding in Beckwith-Wiedemann syndrome and other findings include postnatal somatic gigantism, abdominal wall defects, nevus flammeus of the face, congenital heart defects, and cleft palate. The aim of this case presentation is to describe the dental treatment of a child with Beckwith-Wiedemann syndrome. A 3-year-old boy with Beckwith-Wiedemann syndrome visited to the Seoul National University Dental Hospital for dental evaluation and treatment. Due to the multiple caries and poor cooperation, we planned to perform the dental procedure under general anesthesia. The dental procedure was successfully performed and there was no airway complications after extubation. This case suggests that general anesthesia may be useful for the patient with uncooperative Beckwith-Wiedemann syndrome, since macroglossia and laryngomalacia may exacerbates airway compromise during dental sedation.

• Journal of the Korean Institute of Gas
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• v.11 no.2 s.35
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• pp.60-64
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• 2007

Chemical Process industry in Korea has over 30 year's of history and is likely to face potential incidents. The traditional risk analysis and control system in Chemical Process industry focuses on mechanical defects, overlooking the human performance control. Although development of automation technology and controlling technology was necessary, human decision factor is essential to preventing accidents in the Chemical Process. Almost all serious accidents take place when inappropriate humanperformance and mechanical defects of safety equipments simultaneously occurs. The AHRA(Advanced Human Reliability Analyzer) software has been developed to collect failure data and analyze human error probability (Reliability) in Chemical Process Industry in Korea. This paper describes the HRA analysis result of PIF(Performance Influencing Factor) evaluation, HEP(Human Error Probability) and root cause of accidents by applying a Chemical Process Industry related accident data. This analysis result should present a scheme that, by controlling human error factor other than putting safety management funds into the machinery in plants, can reduce cost and maximize the safety in Chemical Process Industry.

• The Journal of the Society of Stroke on Korean Medicine
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• v.22 no.1
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• pp.21-30
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• 2021

■ Background Patients with posterior cerebral artery infarction could complain of visual field defects or prosopagnosia that does not recognize a person's face. However, there has been no standardized treatment for these symptoms. ■ Case report A 57-year-old male patient complained homonymous hemianopia and prosopagnosia after posterior cerebral artery infarction. After combined Korean medicine treatment for 49 days, subjective visual field was improved and the discomfort associated with visual field defect and the disability of recognizing people was decreased. Evaluations were took place by assessing visual field using Automated Perimetry and Confrontation visual field exam. Discomfort caused by visual field defects or prosopagnosia was evaluated by visual analog scale. The patient was treated with acupuncture, moxibustion, and herbal medications. ■ Conclusion The present case report suggests that combined Korean medicine treatment might be effective to resolution of homonymous hemianopia and prosopagnosia after stroke.

• Archives of Plastic Surgery
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• v.46 no.5
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• pp.426-432
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• 2019

Background The mandible is an important structure that is located in the lower third of the face. Large mandibular defects after tumor resection cause loss of its function. This study assessed the outcomes and tumor recurrence after immediate mandibular reconstruction using a free fibula osteocutaneous flap following radical resection of ameloblastoma. Methods This is a retrospective non-randomized study of outcomes and tumor recurrence of all patients diagnosed with mandibular ameloblastoma from August 1997 until August 2017 (20 years) requiring free fibula osteocutaneous flap reconstruction at a single institution. The patients were identified through an electronic operative database; subsequently, their medical records and photo documentation were retrieved. Results Twenty-seven patients were included in this study. Eighteen patients were male, while nine were female. The majority of the patients (48.1%) were in their third decade of life when they were diagnosed with ameloblastoma. All of them underwent radical resection of the tumor with a surgical margin of 2 cm (hemimandibulectomy in cases with a large tumor) and immediate mandibular reconstruction with a free fibula osteocutaneous flap. Two patients required revision of a vascular anastomosis due to venous thrombosis postoperatively, while one patient developed a flap recipient site infection. The flap success rate was 100%. There was no tumor recurrence during a mean follow-up period of 5.6 years. Conclusions Mandibular ameloblastoma should be treated with segmental mandibulectomy (with a surgical margin of 2 cm) to reduce the risk of recurrence. Subsequent mandibular and adjacent soft tissue defects should be reconstructed immediately with a free fibula osteocutaneous flap.