• Journal of Korean Institute of Industrial Engineers
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• v.40 no.3
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• pp.283-290
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• 2014

In the flat panel display industry, to meet production target quantities and the deadline of production, the scheduler and dispatching systems are major production management systems which control the order of facility production and the distribution of WIP (Work In Process). Especially the delivery time is a key factor of the dispatching system for the time when a lot can be supplied to the facility. In this paper, we use survival analysis methods to identify main factors of the delivery time and to build the delivery time forecasting model. To select important explanatory variables, the cox proportional hazard model is used to. To make a prediction model, the accelerated failure time (AFT) model was used. Performance comparisons were conducted with two other models, which are the technical statistics model based on transfer history and the linear regression model using same explanatory variables with AFT model. As a result, the mean square error (MSE) criteria, the AFT model decreased by 33.8% compared to the statistics prediction model, decreased by 5.3% compared to the linear regression model. This survival analysis approach is applicable to implementing the delivery time estimator in display manufacturing. And it can contribute to improve the productivity and reliability of production management system.

• Radiation Oncology Journal
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• v.36 no.4
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• pp.317-324
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• 2018

Purpose: This study aimed to evaluate the long-term survival outcomes and prognostic factors that affect the clinical outcomes of patients who underwent surgery and postoperative radiotherapy for major salivary gland mucoepidermoid carcinoma (MEC). Materials and Methods: We retrospectively reviewed the clinical data of 44 patients who underwent surgery followed by radiotherapy for primary MEC of the major salivary glands between 1991 and 2014. The median follow-up period was 9.8 years (range, 0.8 to 23.8 years). Results: The overall outcomes at 5 and 10 years were 81.5% and 78.0% for overall survival (OS), 86.2% and 83.4% for disease-free survival, 90.6% and 87.6% for locoregional recurrence-free survival, and both 90.5% for distant metastasis-free survival (DMFS). Histologic grade was the only independent predictor of OS (low vs. intermediate vs. high; hazard ratio = 3.699; p = 0.041) in multivariate analysis. A poorer survival was observed among patients with high-grade tumors compared with those with non-high-grade tumors (5-year OS, 37.5% vs. 91.7%, p < 0.001; 5-year DMFS, 46.9% vs. 100%, p < 0.001). Conclusion: Surgery and postoperative radiotherapy resulted in excellent survival outcomes for patients with major salivary gland MEC. However, high-grade tumors contributed to poor DMFS and OS. Additional aggressive strategies for improving survival outcomes should be developed for high-grade MEC.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3937-3940
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• 2015

Background: Pancreatic cancer risk is increased in patients with type 2 diabetes, while being reduced by metformin treatment. However, it is unclear whether metformin could be associated with clinical outcomes of patients with pancreatic cancer and concurrent type 2 diabetes. Materials and Methods: A pooled analysis of 4 publications including 1,429 patients was performed to investigate the association of metformin and overall survival(OS) in patients with pancreatic cancer and concurrent type 2 diabetes. Results: A borderline significant relative survival benefit was found in metformin treated patients compared with non-metformin treated patients (hazard ratio 0.80; 95% CI: 0.62-1.03). Conclusions: These results suggest that further investigation is warranted of whether metformin may benefit the survival of patients with pancreatic cancer and concurrent type 2 diabetes.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.25-28
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• 2014

Background: This study analyzed whether socio-economic factors affect the cause specific survival of soft tissue sarcoma (STS). Methods: Surveillance, Epidemiology and End Results (SEER) soft tissue sarcoma (STS) data were used to identify potential socio-economic disparities in outcome. Time to cause specific death was computed with Kaplan-Meier analysis. Kolmogorov-Smirnov tests and Cox proportional hazard analysis were used for univariate and multivariate tests, respectively. The areas under the receiver operating curve were computed for predictors for comparison. Results: There were 42,016 patients diagnosed STS from 1973 to 2009. The mean follow up time (S.D.) was 66.6 (81.3) months. Stage, site, grade were significant predictors by univariate tests. Race and rural-urban residence were also important predictors of outcome. These five factors were all statistically significant with Cox analysis. Rural and African-American patients had a 3-4% disadvantage in cause specific survival. Conclusions: Socio-economic factors influence cause specific survival of soft tissue sarcoma. Ensuring access to cancer care may eliminate the outcome disparities.

• Journal of the Korean Data and Information Science Society
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• v.23 no.2
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• pp.257-269
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• 2012

Global crisis expedites the change in the environment of industry and puts small size enterprises in danger of mass bankruptcy. Because of this, domestic small size enterprises is an urgent need of restructuring. Based on the small business data registered in the Credit Guarantee Fund, we estimated the survival probability in the context of the survival analysis. We also analyzed the survival time which are distinguished depending on the types of business in the small business. Financial variables were also conducted using COX regression analysis of small businesses by types of business. In terms of types of business wholesale and retail trade industry and services were relatively high in the survival probability than light, heavy, and the construction industries. Especially the construction industry showed the lowest survival probability. In addition, we found that construction industry, the bigger BIS (bank of international settlements capital ratio) and current ratio are, the smaller default-rate is. But the bigger borrowing bond is, the bigger default-rate is. In the light industry, the bigger BIS and ROA (return on assets) are, the smaller a default-rate is. In the wholesale and retail trade industry, the bigger bis and current ratio are, the smaller a default-rate is. In the heavy industry, the bigger BIS, ROA, current ratio are, the smaller default-rate is. Finally, in the services industry, the bigger current ratio is, the smaller a default-rate is.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8331-8335
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• 2014

Background: Previous studies accessing the association of CYP2C19 with outcomes of patients using tamoxifen for breast cancer have yielded conflicting results. The aim of this meta-analysis is to obtain a more precise estimate of effects of CYP2C19 polymorphisms and to clarify their effects on survival of the breast cancer patients using tamoxifen. Materials and Methods: A systematic search of PubMed and Embase was performed, comparing patients with or without $CYP2C19^*2$ and $CYP2C19^*17$, relevant articles searched for. The following outcomes were included from the eligible studies: disease-free survival (DFS) and overall survival (OS), expressed by hazard ratios (HR) with corresponding 95% confidence interval (CI). Subgroup analysis by genotypes was also performed. Pooled estimates were calculated using random-effect model in accordance to the heterogeneity. Results: Six studies met the inclusion criteria. The integrated OR on the association between CYP2C19 and DFS, calculated by the random-effect model, was 0.54 (95%CI=0.34-0.84, p=0.013). Subgroup analysis showed that both $CYP2C19^*2$ and $CYP2C19^*17$ were associated with increased survival. The pooled results of two studies for OS were OR=0.46 (95%CI=0.21-1.01, p=0.233). Conclusions: This meta-analysis suggests that the $CYP2C19^*2$ and $CYP2C19^*17$ genotypes are associated with increased survival in breast cancer patients using tamoxifen.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.263-264
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• 2006

For practical electrical insulation design of high temperature superconducting (HTS) power apparatuses, knowledge of the dielectric behavior of insulators in cryogenic liquid such as liquid nitrogen ($LN_2$) is essential. So in this paper, we discussed experimental investigations of breakdown and V-t characteristics of several insulators such as Kapton and glass fiber reinforced plastic (GFRP) that are candidates of insulator for HTS apparatus in cryogenic liquid. And we investigated the degradation of these insulation samples after breakdown with the microscope and SEM photograph. Moreover, survival and hazard analysis were performed.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6023-6026
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• 2012

The incidence of hepatocellular carcinoma (HCC) in Malaysia for the year 2001 was 2.8 per 100,000 people. The mortality rate is increasing. A retrospective cohort study measuring the survival of HCC patients who received treatment in Selayang Hospital was conducted from 1 January 2003 to 31 December 2006. The main objectives of the study were to measure the survival of the patients and to understand the influencing factors, especially ethnicity. The subjects were newly diagnosed cases of HCC by CT scan and histopathological assessment who underwent futher investigations and treatments in Hospital Selayang (inception cohort). The survival time was measured from the date of diagnosis until the subjects died, or failed to follow-up at the end of the study period (31 December 2007). A total of 299 patients were selected with 95 patients dying, the majority among Chinese (39.1%). Subgroup analysis according to ethnicity proved significantly that Chinese patients who had smaller tumor, less number of nodules, low AFP level, Child Pugh Class A and received surgical treatment had a better median survival rate compared to other ethnic groups. Malay (cHR: 1.3, 95%CI; 0.89-1.85) and Indian (cHR: 1.3, 95%CI; 0.74-2.26) patients had a poor survival compared to Chinese patients, but not in the final model. Therefore ethnicity may play a role in survival of HCC patients, but not as a main hazard prognostic factor.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.2
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• pp.35-54
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• 2009

The recent economic crisis not only reduces the profit of department stores but also incurs the significance losses caused by the increasing late-payment rate of credit cards. Under this pressure, the scope of credit prediction needs to be broadened from the simple prediction of whether this customer has a good credit or not to the accurate prediction of how much profit can be gained from this customer. This study classifies the delinquent customers of credit card in a Korean department store into homogeneous clusters. Using this information, this study analyzes the repayment patterns for each cluster and develops the credit prediction system to manage the delinquent customers. The model presented by this study uses Kohonen network, which is one of artificial neural networks of data mining technique, to cluster the credit delinquent customers into clusters. Cox proportional hazard model is also used, which is one of survival analysis used in medical statistics, to analyze the repayment patterns of the delinquent customers in each cluster. The presented model estimates the repayment period of delinquent customers for each cluster and introduces the influencing variables on the repayment pattern prediction. Although there are some differences among clusters, the variables about the purchasing frequency in a month and the average number of installment repayment are the most predictive variables for the repayment pattern. The accuracy of the presented system leaches 97.5%.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.sup3
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• pp.65-70
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• 2016

Lung cancer is one of the most common malignancies in the world. Its incidence and mortality rates are on the rise in Pakistan. However, epidemiological studies to identify common lung cancer determinants in the Pakistani population have been limited. In this study, data of 440 cases and 323 controls were collected from different hospitals in Peshawar and Islamabad, along with information about socio-demographic factors including age, sex and smoking. Univariate and multi-factorial analyses of socio-demographic factors in association with each other were also performed. Overall survival analysis highlighted that, out of 440 patients in the lung cancer dataset, 204 people were uncensored with a median survival time of 13 months (95% CI=12-18). There were 41 femaleand 399 male patients. Differences were observed between length of survival in the males and females (${\chi}12$ = 6.1; p-value = 0.01). Gender was observed to be significantly related to survival (p-value< 0.01), with better survival in females (hazard ratio=2). Cox regression was extended to adjust for the covariate age (z = 2.5; p-value = 0.02). Survival analysis was also performed on the basis of smoking groups (current smokers, former smokers and never smoked individuals) and smoking duration (smoking duration >10 years, <10 years and never smoked). Smoking duration was significantly associated with survival (p-value < 0.01), with better survival in never smokers in comparison to both smoking for greater or less than 10 years. Strong associations were observed for smoking group with duration greater than 10 years, OR=6.1(3.9-9.5) on univariate and multifactorial analysis OR=11.3(CI=6.8-19.3).