• Proceedings of the KSME Conference
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• 2003.04a
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• pp.201-206
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• 2003

This study is test for STS304 specimen using bending and torsion state. Rounded specimen and notched specimen including fracture surface investigation was comparatively experimented, fatigue life according to degree of surface finishing was examined. Fatigue fracture probability of notched canilever specimens were predicted by P-S-N curve, median rank and Weibull distribution. And at the relation with the rotational speed and stress, the fatigue life of the test specimen was higher at high speed than low speed If summarize STS304 torsion result of fatigue test, is as following. Fatigue life prediction was available by Weibull statistics distribution, and 50% breakdown probability correlation equation was appeared as following.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.199-204
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• 2001

Big accidents of flyings, vessel, subways, gas equipments, buildings and bridge happens frenquently. Therefore many people are suffering harm of property. The destruction cause of macaine components is almost accused by fatigue. This study is test for STS304 specimen using pure and cantilever bending state. Rounded specimen and notched specimen including fracture surface investigation was comparatively experimented, fatigue life according to degree of surface finishing was examined. Fatigue fracture probability of notched canilever specimens were predicted by P-S-N curve, median rank and Weibull distribution. And at the relation with the rotational speed and stress, the fatigue life of the test specimen was higher at high speed than low speed.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.119-123
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• 2000

The characteristics of fatigue life distribution for Carbon/epoxy composite laminates was investigated under tension-tension loading(R=0.1). The statistical nature of the fatigue life of the composite materials was analyzed by Weibull, normal, lognormal distributions As a result, it was observed that the correlation between the experimental results and the theoretical predictions for the fatigue life is good. The distribution of the static ultimate strength has the characteristic of lognormal distribution and distribution of the fatigue life has characteristics of the weibull distribution.

• Radiation Oncology Journal
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• v.24 no.4
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• pp.243-247
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• 2006

$\underline{Purpose}$: To evaluate the treatment results and prognostic factors of palliative radiation therapy in the patients with unresectable advanced pancreatic cancer. $\underline{Materials\;&\;Methods$: Thirty-seven evaluable patients with unresectable advanced pancreatic cancer who were treated by palliative radiation therapy for pain relief at the Department of Radiation Oncology, Kangnam St. Mary's hospital, the Catholic University of Korea between March 1984 and February 2005 were analysed retrospectively. There were 22 men and 15 women. Age at diagnosis ranged from 30 to 80 (median 57) years. Twelve patients (32.4%) had liver metastases and 22 patients (59.5%) had lymph node metastases. Radiation therapy was delivered to primary tumor and regional lymph nodes with $1{\sim}2\;cm$ margin, and total dose was $3,240{\sim}5,580\;cGy$ (median 5,040 cGy). Chemotherapy with radiotherapy was delivered in 30 patients (81%) with 5-FU alone (21 patients) or gemcitabine (9 patients). The follow-up period ranged from 1 to 44 months. Survival and prognostic factors were analysed using Kaplan-Meier method and log-rank test respectively. $\underline{Results}$: Overall mean and median survival were 11 and 8 months and 1-year survival rate was 20%. Among 33 patients who were amenable for response evaluation, 7 patients had good response and 22 patients had fair response with overall response rate of 87.9%. Mild to moderate toxicity were observed in 14 patients with nausea, vomiting, and indigestion, but severe toxicity requiring interruption of treatment were not observed. Chemotherapy didn't influence the survival and symptomatic palliation, but the group containing gemcitabine showed a tendency of longer survival (median 12 months) than 5-FU alone group (median 5.5 months) without statistical significance (p>0.05). The significant prognostic factors were Karnofsky performance status and liver metastasis (p<0.05). Age, sex, tumor location, lymph node metastasis, and CA 19-9 level did not show any prognostic significance (p>0.05). $\underline{Conclusion}$: Radiation therapy was effective for symptomatic palliation in the patients with unresectable advanced pancreatic cancer and would play an important part in the survival benefit with gemcitabine or other targeted agents.

• Radiation Oncology Journal
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• v.19 no.4
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• pp.306-311
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• 2001

Purpose : In this retrospective study, we attempted to evaluate the treatment outcome and the prognostic factors of thymoma treated with surgery, radiotherapy and chemotherapy. Methods and materials : Between 1979 and 1998, 55 patients with thymoma were treated at the Seoul National University Hospital. Of these, 11 patients underwent surgery only, 33 patients received post-operative radiotherapy and 11 patients received radiotherapy only. Twenty-three patients had gross total resection and 21 patients subtotal resection. For postoperative radiotherapy, the radiation dose consisted of $41.4\~55.8\;Gy$. The average follow-up was 64 months, and ranged from 2 to 160 months. The sex ratio was 1:1 and the median age was 48 years $(15\~74\;years)$. Overall survival and disease-free survival were determined via the Kaplan-Meier method, and the log-rank was employed to evaluate for differences in prognostic factor. Results : The five- and 10-year survivai rates were $87\%\;and\;65\%$ respectively, and the median survival was 103 months. By univariate analysis, only stage (p=0.0017) turned out to be significant prognostic factors of overall survival. Also, stage (p=0.0007) was significantly predictive for overall survival in mutivariated analysis. Conclusion : This study showed the stage was found to be important prognostic factors, which influenced survival. Especially, as incomplete resection is related with poor results, complete resection is important to cure the invasive thymoma.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.517-523
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• 1996

From May 1988 to June 1994, )73 patients underwent exploratory thoracotomy for resection of non- small cell lung cancer, and 48 patients staged pathologically as lIIB were analyzed. 74 lesions were involvement of great vessel (n=26), heart (n=5), ipsilateral lung metastasis(n=4), esophagus (n=4), carina(n=3), mediastinum (n=2), trachea(n=1), spine (n=1) and 13lourO seeding(A=15). N3 lesions were involved in 6 patients. Extended pulmonary resection with radical mediastinal node dissection was possible in 25 patients, and exploration only was performed in 23 patients. The most frequent cause of unresectability was pleural seeding. Postoperative morbidity was )2 % (8125) and mortality was 16 % (41 25) in resected group. The adjutant therapy was given to 37 patients. The 1 year and 3 year survival for resected group ncluding operative deaths was 57.2%, and 2).8 % (median 15 months), but 48.4%, and 0 % (median 7 months) for exploration only group (Log-Rank test, p : 0.17). Our results suggest that extended pulmonary resection might be helpful for carefully selected patients with 74 non-small cell lung cancer, but meticulous preoperative work-up for staging, especially to detect pleural seeding and Invasion to the irlediastinal structures is a prerequisite to avoid unnecessary thoracotomy.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3941-3944
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• 2013

Background: The use of preoperative chemoirradiation is the commonest treatment strategy employed in Malaysia for locally advanced rectal cancer. We need to determine the local control and survival rates for comparison with established rates in the literature. Materials and Methods: This retrospective study analyzed all newly diagnosed patients with rectal adenocarcinoma who underwent long course preoperative radiotherapy (RT) at the Department of Radiotherapy and Oncology, Kuala Lumpur Hospital (HKL) between $1^{st}$ January 2004 and $31^{st}$ December 2010. The aim of the study was to determine the radiological response post radiotherapy, pathological response including circumferential resection margin (CRM) status, 3 years local control, 3 years overall survival (OS) and 3 years disease free survival (DFS). Statistical analysis was performed using the SPSS software. Kaplan-Meier and log rank analysis were used to determine survival outcomes. Results: A total of 507 patients with rectal cancer underwent RT at HKL. Sixty seven who underwent long course preoperative RT were eligible for this study. The median age at diagnosis was 60 years old with a range of 26-78 years. The median tumour location was 6 cm from the anal verge. Most patients had suspicion of mesorectum involvement (95.5%) while 28.4% of patients had enlarged pelvic nodes on staging CT scan. All patients underwent preoperative chemo-irradiation except for five who had preoperative RT alone. Only 38 patients underwent definitive surgery (56.7%). Five patients were deemed to be inoperable radiologically and 3 patients were found to have unresectable disease intraoperatively. The remaining 21 patients defaulted surgery (31.3%). The median time from completion of RT to surgery was 8 weeks (range 5.6 to 29.4 weeks). Fifteen patients (39.5%) had surgery more than 8 weeks after completion of RT. Complete pathological response was noted in 4 patients (10.5%). The pathological CRM positive rate after RT was 18.4%. With a median follow-up of 38.8 months, the 3 year local control rate was 67%. The 3 years rate for CRM positive (<2 mm), CRM clear (>2 mm) and pCR groups were 0%, 88.1% and 100% respectively (p-value of 0.007). The 3 year OS and DFS were 57.3% and 44.8% respectively. Conclusions: In conclusion, the approach of long course preoperative chemoirradiation for rectal cancer needs to be re-examined in our local setting. The high rate of local recurrence is worrying and is mainly due to patient defaulting post-preoperative chemoirradiation or delayed definitive surgery.

• Health Policy and Management
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• v.23 no.2
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• pp.176-187
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• 2013

Background: In 2006 Emergency Medical Services Index (EMSI), which summarizes the performance of regional emergency medical services system, was developed. This study assesses the performance of the EMSI to help determine whether EMSI can be used as evaluation tool. Methods: To build a composite score of the EMSI from predefined 24 indicators, 3 normalized values were calculated for each indicator, the normalized values of each indicator were weighted using 4 weighting methods, and the weighted values were aggregated into the final composite score using 2 aggregation schemes. The performance of EMSI was evaluated using 3 criteria: discrimination, construct validity, and sensitivity. Discrimination was the proportion of regions that did not include the overall median rank in the 5th to 95th percentiles rank interval, which was calculated from Monte Carlo simulation. Construct validity was a correlation among the alternative EMSIs. Sensitivity of EMSIs was evaluated by total shift of quartile membership and changes of 5th to 95th percentile intervals. Results: The total discrimination performance of the EMSI was 50.0%. Correlation coefficients between EMSIs using standardized values and those using rescaled values ranged from 0.621 to 0.997. Variation of the quartile membership of regions ranged from 0.0% to 75.0%. The total change in the 5th to 95th percentile intervals ranged from -19 to +17 places. Conclusion: The results suggested that the EMSI could be used as a tool for evaluating quality of regional EMS system and for identifying the areas for quality improvement.

• Journal of Preventive Medicine and Public Health
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• v.46 no.5
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• pp.226-236
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• 2013

Objectives: The aim of this study was to examine the levels of serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and evaluate their association with age, body mass index, smoking, military record-based variables, and estimated exposure to Agent Orange in Korean Vietnam veterans. Methods: Serum levels of TCDD were analyzed in 102 Vietnam veterans. Information on age, body mass index, and smoking status were obtained from a self-reported questionnaire. The perceived exposure was assessed by a 6-item questionnaire. Two proximitybased exposures were constructed by division/brigade level and battalion/company level unit information using the Stellman exposure opportunity index model. Results: The mean and median of serum TCDD levels was 1.2 parts per trillion (ppt) and 0.9 ppt, respectively. Only 2 Vietnam veterans had elevated levels of TCDD (>10 ppt). The levels of TCDD did not tend to increase with the likelihood of exposure to Agent Orange, as estimated from either proximity-based exposure or perceived self-reported exposure. The serum TCDD levels were not significantly different according to military unit, year of first deployment, duration of deployment, military rank, age, body mass index, and smoking status. Conclusions: The average serum TCDD levels in the Korean Vietnam veterans were lower than those reported for other occupationally or environmentally exposed groups and US Vietnam veterans, and their use as an objective marker of Agent Orange exposure may have some limitations. The unit of deployment, duration of deployment, year of first deployment, military rank, perceived self-reported exposure, and proximity-based exposure to Agent Orange were not associated with TCDD levels in Korean Vietnam veterans. Age, body mass index and smoking also were not associated with TCDD levels.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4045-4050
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• 2012

Objective: The impact of ablative oral cancer surgery was studied, with particular reference to recurrence and nodal metastasis, to assess survival probability and prognostic indicators and to elucidate if ethnicity influences the survival of patients. Methods: Patients who underwent major ablative surgery of the head and neck region with neck dissection were identified and clinical records were assessed. Inclusion criteria were stage I-IV oral and oropharyngeal malignancies necessitating resection with or without radiotherapy from 2004 to 2009. All individuals had a pre-operative assessment prior to the surgery. The post operative assessment period ranged from 1 year to 5 years. Survival distributions were analyzed using Kaplan-Meier curves. Results: 87 patients (males:38%; females:62%) were included in this study, with an age range of 21-85 years. Some 78% underwent neck dissections while 63% had surgery and radiotherapy. Nodal recurrence was detected in 5.7% while 20.5% had primary site recurrence within the study period. Kaplan-Meier survival analysis revealed that the median survival time was 57 months. One year overall survival (OS) rate was 72.7% and three year overall survival rate dropped to 61.5%. On OS analysis, the log-rank test showed a significant difference of survival between Malay and Chinese patients (Bonferroni correction p=0.033). Recurrence-free survival (RFS) analysis revealed that 25% of the patients have reached the event of recurrence at 46 months. One year RFS rate was 85.2% and the three year survival rate was 76.1%. In the RFS analysis, the log-rank test showed a significant difference in the event of recurrence and nodal metastasis (p<0.001). Conclusion: Conservative neck is effective, in conjunction with postoperative radiotherapy, for control of neck metastases. Ethnicity appears to influence the survival of the patients, but a prospective trial is required to validate this.