• Journal of the military operations research society of Korea
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• v.35 no.2
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• pp.33-49
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• 2009

The objective of this study is as follows. First, the hazard function on the failure probability density function of the K-1 tracked vehicles can be occurred in the form of the bathtub curve. Second, the failure mode may be different under two different operational situations. The research result shows that the bathtub curve can be fitted in the Weibull distribution, that assumes different shapes according to the specific stage of the system's life cycle. The K-1 tracked vehicle has a relatively high hazard(failure) rate at the time of its first service. The failure rate starts decreasing for a time immediately after it goes into service. After the break-in period, the surviving components have a fairly constant hazard rate. As the K-1 system ages, deterioration of its various parts takes place and the hazard rate starts Increasing. Second, the result shows the failure rate in the harsh operational environment is higher than that in the mild operational environment. In conclusion, the bathtub curve can be logically appropriate in establishing the depot overhaul cycle. Moreover, it is necessary for determining the right time of the depot overhaul to consider not only the age of defense equipment but also the different operational environment.

• Radiation Oncology Journal
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• v.13 no.2
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• pp.191-198
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• 1995

Purpose: This analysis was to compare the result of radiation alone and chemoradiation in cervical cancer in terms of response, survival, failure, and complication. Materials and Methods: A retrospective analysis of 135 cervical cancer patients treated with definitive radiotherapy from November 1985 to December 1991 was performed. Fifty-six patients were treated with radiation alone and 79 patients were treated with cisplatin-based chemotherapy plus radiation. Follow-up period ranged from 5 to 105 months with a median 47 months. According to the FIGO classification, the patients were subdivided into 18 $(13.3\%)$ stage IB, 7 $(5.2\%)$ stage IIA, 97 $(71.9\%)$ stage IIB, and 9 $(6.7\%)$ stage IIIB. Results: A complete response was noted in 51 patients $(91.1\%)$ of the radiation alone group, and 68 patients $(86.1\%)$ of the chemoradiation group. There was no statistical difference in complete response rate between the two groups. Overall survival rate at 5 years was $73.3\%$. According to stage, overall survival rates at 5 years were $88.9\%$ in stage IB, $85.7\%$ in stage IIA, $73.8\%$ in stage IIB, and $37.5\%$ in stage IIIB, respectively. According to treatment modality, overall survival rates at 5 years were $81.9\%$ in the radiation alone group, $67.0\%$ in the chemoradiation group (p=0.22). Disease-free survival rate at 5 years were $70.4\%$ in the radiation alone group. $68.5\%$ in the chemoradiation group (p=0.85) Locoregional control rates at 5 years were $76.1\%$ in the radiation alone group, $73.8\%$ In the chemoradiation group (p=0.70). Distant disease-free survival rates at 5 years were $83.9\%$ in the radiation alone group, $90.3\%$ in the chemoradiation group (p=0.59). Treatment-related bone marrow suppressions were noted in 3 $(5.4\%)$ patients of the radiation alone group, 14 patients $(17.7\%)$ of the chemoradiation group (p(0.05). Grade 2 vesical complications were noted in 14 patients of the radiation alone group. and 10 Patients of the chemoradiation group. Grade 2 rectal complications were noted in 2 patients of the radiation alone group, and 3 Patients of the chemoradiation group. One case of rectal perforation was noted in the chemoradiation group, and grade 2 small bowel obstructions were noted in 2 patients of the radiation alone group. There were no statistical differences in the incidence of vesicar, rectal, and small bowel complicaions between the two groups. Conclusion: No statistical difference was found between the radiation alone group and the chemoradiation group in terms of response, survival, and failure. but the incidence of bone marrow suppression was higher in the chemoradiation group.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.1
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• pp.9-17
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• 2015

Glycogen storage disease (GSD) type Ia is rare inborn metabolic disorder, caused by glucose-6-phosphatase deficiency. It characterized by hepatomegaly, hypoglycemia, lactic acidosis, hypertriglyceridemia, and hyperuricemia and it is usually manifested in the infantile period. In addition, it is also associated with growth failure, pubertal delay, anemia, platelet dysfunction, osteopenia, and pulmonary hypertension. Hepatocellular adenoma and renal dysfunction are frequent late complications. Delayed diagnosis and inappropriate therapy lead to many complications such as growth failure, osteoporosis, refractory gout, renal failure, hepatocellular carcinoma (HCC), and pulmonary hypertension. Here, two Korean sisters diagnosed with GSD Ia, aged 33 and 36 respectively, were described and compared to recent articles about four adults with late diagnosis of GSD Ia. One sister had typical manifestations of GSD Ia including short stature (height, 145 cm), multiple hepatic adenoma, chronic kidney disease stage IV, and severe osteoporosis, whereas the older sister had normal stature (162 cm), one tiny hepatic nodule, and normal renal function. Direct sequencing of G6PC in two sisters identified a homozygous splicing mutation, c.645G>T, which is a prevalent mutation in Korea. Interestingly, our cases and four adults from recent reports had asymptomatic mild hypoglycemia and various manifestations including renal failure, HCC, fatty liver, or uncontrolled hyperlipidemia. These adult cases represent not only heterogenous phenotype to genotype within family members with GSD Ia but also long-term complications such as gouty arthritis, renal failure, and osteoporosis in untreated adult GSD Ia patients. In addition, lactic academia and hypertriglyceridemia are good markers of GSD Ia to distinguish from metabolic disease.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.172-178
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• 2015

Purpose: To investigate clinical outcomes of synchronous head and neck and esophageal cancer (SHNEC). Materials and Methods: We retrospectively reviewed 27 SHNEC patients treated with curative intent at a single institution. The treatment modality for individual cases was usually determined on a case by case basis. Results: The median follow-up duration for the surviving patients was 28.2 months. The most common site of head and neck cancer was hypopharyngeal carcinoma (n = 21, 77.7%). The lower esophagus was the most common location of esophageal carcinoma (n = 16, 59.3%). The 2-year progression-free survival (PFS) and overall survival (OS) rates were 57.5% and 39.6%. Major pattern of failure was locoregional recurrence in the study patients. Esophageal cancer stage, the Eastern Cooperative Oncology Group (ECOG) performance status, and pretreatment weight loss were significant prognostic factors for OS in univariate analysis. Treatment-related death was observed in two patients, and one patient developed a grade 4 late treatment-related complication. Conclusion: Although the survival outcome for SHNEC is poor, long-term survival might be achievable with aggressive treatment with stage I-II esophageal cancer and good performance.

• Earthquakes and Structures
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• v.12 no.1
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• pp.55-65
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• 2017

Earthquake resilience of substations is essential for reliable and sustainable service of electrical grids. The majority of substation equipment consists of cylindrical porcelain components, which are vulnerable to earthquake shakings due to the brittleness of porcelain material. Failure of porcelain equipment has been repeatedly observed in recent earthquakes. Hence, proper seismic modelling of porcelain equipment is important for various limit state checks in both product manufacturing stage and detailed substation design stage. Sheds on porcelain core and cemented joint between porcelain component and metal cap have significant effects on the dynamic properties of the equipment, however, such effects have not been adequately parameterized in existing design guidelines. This paper addresses this critical issue by developing a method for taking these two effects into account in seismic modelling based on numerical and analytical approaches. Equations for estimating the effects of sheds and cemented joint on flexural stiffness are derived, respectively, by regression analyses based on the results of 12 pieces of full-scale equipment in 500kV class or higher. The proposed modelling technique has further been validated by shaking table tests.

• Journal of Chest Surgery
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• v.45 no.6
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• pp.415-417
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• 2012

The development of Morgagni hernias is related to malformations of the embryologic septum transversum after failure of the sternal and costal fibrotendinous elements of the diaphragm to fuse. The overall incidence of Morgagni hernias among all congenital diaphragmatic defects is 3% to 4%. Inguinal hernias are the most common hernias in males and females (25% and 2%, respectively). An inguinal hernia is defined as a protrusion of the abdominal cavity contents through the inguinal canal. The combination of Morgagni and inguinal hernias is rare, and treatment using laparoscopic surgery has not been previously reported. This case presents a one-stage laparoscopic repair of Morgagni and inguinal hernias in a 2-month-old male.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.357-373
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• 2022

The high-temperature gas-cooled reactor pebble-bed module project is the first commercial Generation-IV NPP(Nuclear Power Plant) in China. A new joint is used for the vertical support of RPV(Reactor Pressure Vessel). The steel corbel is integrally embedded into the reactor-cabin wall through eight asymmetrically arranged pre-stressed high-strength bolts, achieving the different path transmission of shear force and moment. The vertical monotonic loading test of two specimens is conducted. The results show that the failure mode of the joint is bolt fracture. There is no prominent yield stage in the whole loading process. The stress of bolts is linearly distributed along the height of corbel at initial loading. As the load increases, the height of neutral axis of bolts gradually decreases. The upper and lower edges of the wall opening contact the corbel plate to restrict the rotation of the corbel. During the loading, the pre-stress of some bolts decreases. The increase of the pre-stress strength ratio of bolts has no noticeable effect on the structure stiffness, but it reduces the ultimate bearing capacity of the joint. A simplified calculation model for the elastic stage of the joint is established, and the estimation results are in good agreement with the experimental results.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1357-1362
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• 2016

Metastatic gestational trophoblastic neoplasia (GTN) is an uncommon cancer. The principal treatment consists of chemotherapy with or without surgery or radiotherapy. We here retrospectively reviewed the outcomes of metastatic GTN treated at our institute between January, 1999 and December, 2013. Sixty-three patients met the criteria. The median age was 30.0 years and almost 90% were referral cases. Nearly 40% of the studied patients presented with vaginal bleeding while 22.2% were asymptomatic. The most common antecedent pregnancy was hydatidiform mole (57.1%) followed by term pregnancy (20.6%). The median interval time from antecedent pregnancy to the development of GTN was three months and the median pretreatment B-hCG was 58,274 mIU/ml. Stage III (74.6%) was the most common staging followed by stage IV (20.6%) and stage II (4.8%). The most frequent surgery was hysterectomy (31.7%). Thoracotomy and craniotomy were performed in three and two patients, respectively. The most common first line chemotherapy regimen was methotrexate and folinic acid (36.5%) followed by EMA (etoposide, methotrexate, actinomycin D) (34.9%), EMACO (etoposide, methotrexate, actinomycin D, cyclophosphamide, vincristine) (17.5%) with the remission rate of 66.7%. Nearly one-third of the patients were given a subsequent chemotherapy regimen after failure with the first line therapy and showed a final response rate of 73.0%. However, in stage IV, the response to first line treatment was only 38.5%. In conclusion, the outcomes of metastatic GTN were poor especially with the higher stages.

• Korean Journal of Head & Neck Oncology
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• v.8 no.1
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• pp.25-30
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• 1992

The causes of treatment failure in head and neck cancer are locoregional recurrence, distant metastasis and second primary cancer. The favorite sites of second primary cancer are head and neck, lung and esophagus. But, the incidence of stomach cancer in Korea is the highest of all, high incidence of stomach cancer is expected in head and neck cancer patients. We experienced 2 cases of stomach cancer after successful treatment of primary head and neck cancer at Kang Nam St. Mary's hospital. The first case was a 60-year-old male with nasopharyngeal non-keratinizing carcinoma(stage III, T1N1M0). He received three cycles of induction chemotherapy including cisplatin and 5-fluorouracil followed by radiotherapy which resulted in complete response. Five months after completion of radiotherapy. stomach adenocarcinoma(stage IV, T4N2M1) was diagnosed. He received one cycle of FAM chemotherapy and died 4 months after diagnosis of stomach cancer. The second case was a 50-year-old male with pyriform sinus squamous cell carcinoma(stage II, T2N0M0). He received curative partial pharyngolaryngectomy followed by radiotherapy which result in free of disease. Four months after completion of radiotherapy. stomach adenocarcinoma(stage IV, T4N2M1) was diagnosed. Bypass gastrojejunostomy was performed. The screening test for stomach cancer including upper gastrointestinal X-xay series and/or endoscope of the stomach should be performed periodically for the patients with head and neck cancer in Korea.

• Archives of Plastic Surgery
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• v.46 no.6
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• pp.544-549
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• 2019

Background As the indications for postmastectomy radiotherapy expand, innovative solutions are required to reduce operative complications and reconstructive failure after prosthetic breast reconstruction. In this study, we investigated the effectiveness of acellular dermal matrix (ADM) inlay grafts in preventing postoperative wound dehiscence of irradiated breasts in the context of prosthetic breast reconstruction. Methods A retrospective analysis was conducted of 45 patients who received two-stage prosthetic reconstruction and radiotherapy following mastectomy. An ADM graft was placed beneath the incisional site during the second-stage operation in 19 patients using marionette sutures, whereas the control group did not receive the ADM reinforcement. Patient demographics and complications such as wound dehiscence, capsular contracture, peri-prosthetic infection, cellulitis, and seroma were compared between the two groups. Results During an average follow-up period of 37.1 months, wound dehiscence occurred significantly less often in the ADM-reinforced closure group (0%) than in the non-ADM group (23.1%) (P=0.032). There was no significant difference between the two groups in relation to other complications, such as capsular contracture, postoperative infection, or seroma. Conclusions The ADM inlay graft is a simple and easily reproducible technique for preventing incisional dehiscence in the setting of radiotherapy after prosthetic breast reconstruction. The ADM graft serves as a buttress to offload tension during healing and provides a mechanical barrier against pathogens. Application of this technique may serve to reduce complications in prosthetic breast reconstruction after radiotherapy.