• The Journal of Korean Medicine
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• v.23 no.4
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• pp.91-97
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• 2002

Objective: This study was conducted to know the survival probability of the patients with cerebrovascular disease. Method: 1,341 patients who were suspected of having cerebrovascular disease clinically were investigated by telephone and NHIC (National Health Insurance Corporation) data. Conclusion: 1. The study population was grouped as 'Negative Brain CT findings' (11.8%), 'Hemorrhage' (12.4%) and 'Infarction' (75.7%). 2. The survival probabilities calculated by the Life Table method were statistically significant among brain CT finding groups (P<0.01). 3. The mean survival time calculated by the Kaplan-Meier method were also statistically significant among brain CT finding groups (P<0.01). 4. The result of Cox regression model was that sex (OR=0.7), age (OR=1.07), diabetes mellitus (OR=1.38), and heart disease (OR=1.69) affected the survival of the patients with cerebrovascular disease.

• Journal of the Korean Statistical Society
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• v.26 no.2
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• pp.277-288
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• 1997

For the analysis of survival data including covariates whose effects vary in time, the multiprocess discount survival model is proposed. The parameter vector modeling the time-varying effects of covariates is to vary between time intervals and its evolution between time intervals depends on the perturbation of the next time interval. The recursive estimation of the parameter vector can be obtained at the end of each time interval. The retrospective estimation of the survival function and the forecasting of the survival function of individuals of the specific covariates also can be obtained based on the information gathered until the end of the time interval.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.203-204
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• 2021

Bacteria used in self-healing concrete, which arrest the crack, helps increasing the durability is well known. However, the survival and activity of the bacteria are precisely unknown. In this research, to know the bacteria's survival curve on the surface of the cement composite, bacteria's survival curve has been measured by CFU at different curing days. The survival curve of 3 days and 7 days curing does not show the significant differences in their survival tendency. However, the slope of death phase of 7 days curing was steeper than the 3 days of curing. This research was focused on the death phase but for further research, set of interval time will be reduced and observe the lag phase and exponential phase.

• Journal of the Korean Data and Information Science Society
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• v.19 no.2
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• pp.487-496
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• 2008

Recently survival analysis becomes popular in a variety of fields so that a number of statistical packages are developed for analyzing the survival model. In this paper, several types of survival models are introduced and considered briefly. In addition, widely used three packages(SAS, SPSS, and STATA) for survival data are reviewed and their characteristics are investigated.

• Communications for Statistical Applications and Methods
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• v.4 no.2
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• pp.491-496
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• 1997

For the survival data analysis of no covariate the discount survival model is proposed to estimate the time-varying hazard rate and the survival function recursively. In comparison with the covariate case it provide the distributionally explicit evolution of hazard rate between time intervals under the assumption of a conjugate gamma distribution. Also forecasting of the hazard rate in the next time interval is suggested, which leads to the forcecasted survival function.

• Journal of Chest Surgery
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• v.41 no.5
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• pp.586-590
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• 2008

Background: Non-small cell lung cancer (NSCLC) patients histologically proven to have stage N2 disease by media-stinoscope or thoracoscope underwent subsequent neoadjuvant chemoradiotherapy. This study was designed to find out if there were any differences in survival or recurrence rates between N2 positive and N2 negative patients. Material and Method: Between January 1998 and December 2005, we retrospectively analyzed 69 patients who were divided into three groups. Group A consisted of patients whose N stage was downstaged, group B of patients whose N stage was the same, and Group C of patients who could not undergo surgery because of disease progression during neoadjuvant chemoradiotherapy. We analyzed and compared the mean survival, three-year survival, mean disease-free survival, and three-year disease-free survival rates for the three groups. Result: There were no demographic differences among the groups. The mean survival was 58, 47, and 21 months for groups A, B, and C, respectively. The mean survival was longest in group A, but no statistically significant difference was found on A-B or B-C group comparison (p>0.05). However, a significant difference was noted between group A and group C (p : 0.01). Three-year survival rates were 67%, 41%, and 21.6% for groups A, B, and C, respectively, with a statistical difference similar to that seen in mean survival. The mean disease-free survival was 44 months in group A and 45 months in group B, with no statistically significant difference noted. No significant differences were noted in the three-year disease-free survival rates (55.1%, 46.8%). Conclusion: There were no significant differences in survival or recurrence rates with changes in N stage after neoadjuvant chemoradiotherapy. However, mean survival, three-year survival, and three-year disease-free survival rates tended to be higher in downstaged patients. Nevertheless, the difference was statistically insignificant, and therefore further studies with more patients and longer follow-up are necessary to clarify the positive effects on the survival and prognosis of downstaged patients.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.328-341
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• 1987

We reviewed 147 cases of primary carcinoma of the lung between January 1975 and December 1986 at the Thoracic and Cardiovascular Department, Yonsei university College of Medicine, Seoul, Korea. There were 116 males and 31 females with 93.72% ranging in age from 40 to 69 years. The mean age was 61.01 years. To 69 years of age with 61.01 years of mean age. There were 92 [62.59%] cases of squamous cell carcinoma, 29 [19.73%] cases of adenocarcinoma, 8 [5.44%] cases of undifferentiated large cell carcinoma, 8 [5.44%] cases of undifferentiated small cell carcinoma and 10 [6.8%] cases of bronchoalveolar cell carcinoma. 50 [34.01%] patients in stage I and 49 [33.26%] patients in stage II underwent pneumonectomies and lobectomies with a 67.27% rate of resection, where as only 49.12% of stage III patients were resected. Also 7 [30.43%] of the 23 stage IV cases were surgically resected and confirmed stage IV after surgical resection. The actuarial survival rate according to classification are as follows. The one and 3 year survival rate of the patients in stage I were 96% and 84% respectively. The one and `3 year survival rate of the patients in stage II were 100% and 66.6%, whereas the one and 3 year survival rate of the patients in stage III, T3 were 78.57% and 69.84%. The survival rates of patients in stage I, II, III T3 were better than those of the other stages. There were significant differences in observed survival for patients with stage II as compared with the patients with stage Ill, T3. [p=0.0005]. An aggressive surgical approach still offered the greatest chance for long-term survival even in stage Ill, T3. The survival rate in patients with resectable cases including stage III, T3 might be improved with an aggressive surgical approach. The one and 3 year survival rates of patients in stage III, N2 were 56.67% and 43.7 I%. The one and 3 year survival rates of patients in stage IV were 21.43% and 3.57%. Patients in stage III, N2 or IV had markedly decreased survival rates. When the carcinoma cell type was the basis for the determination of rate of survival, the result were as follows; The one, 3 and 5 year survival rates of squamous cell carcinoma were 78.33%, 60.19%, and 57.32%, and the one and 3 year survival rates of adenocarcinoma were 55.56% and 44.49%. The survival rates of large cell carcinoma were 66.67%, and 44.45%, at one, three and five years respectively. The one and 3 year survival rates of bronchoalveolar cell carcinoma were 71.43% and 47.62%, the one, 3 and 5 year survival rates of small cell carcinoma were 40%, 20% and 20%. The survival rate of squamous cell carcinoma was better than that of other cell carcinomas, the survival rate of small cell carcinoma was the worst. The operative mortality rate was 1.36%. There were 10 cases of post-operative complications including 2 cases of bleeding which required further surgery, 2 cases of wound infection, and 4 cases of empyema thoracis. The length of survival of three of the empyema thoracis cases was 16, 98 and 108 months respectively, Four male patients all older than 47 years survived more than 9 years, post surgery, although one developed empyema thoracis. These four cases were initially classified as 2 cases of stage I and one each of stage II and stage III, T3. We have concluded that the survival rates of patients in stages I, II and III, T3 were improved after complete surgical resection.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3515-3519
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• 2016

Background: In Thailand, a national treatment protocol for childhood leukemia and lymphoma (LL) was implemented in 2006. Access to treatment has also improved with the National Health Security system. Since these innovations, survival of childhood LL has not been fully described. Materials and Methods: Trends and survival of children under 15 with childhood cancers diagnosed between 1993 and 2012 were investigated using the hospital-based data from the Khon Kaen Cancer Registry, Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand. Childhood cancers were classified into 12 diagnostic groups, according to the ICCC based on the histology of the cancer. Survival rates were described by period, depending on the treatment protocol. For leukemias and lymphomas, survival was assessed for 3 periods (1993-99, 2000-5, 2006-12) while for solid tumors it was for 2 periods (before and after 2000). The impacts of sex, age, use of the national protocol, and catchment area on leukemia and lymphoma were evaluated. Overall survival was calculated using the Kaplan-Meier method while the Cox proportional hazard model was used for multivariate analysis. Trends were calculated using the R program. Results: A total of 2,343 childhood cancer cases were included. Survival for acute lymphoblastic leukemia (ALL) from 1993-9, 2000-5, and 2006-12 improved significantly (43.7%, 64.6%, and 69.9%). This was to a lesser extent true for acute non-lymphoblastic leukemia (ANLL) (28.1%, 42.0%, and 42.2%). Survival of non-Hodgkin lymphoma (NHL) also improved significantly (44%, 65.5%, and 86.8%) but not for Hodgkin disease (HD) (30.1%, 66.1%, and 70.6%). According to multivariate analysis, significant risk factors associated with poor survival in the ALL group were age under 1 and over 10 years, while not using the national protocol had hazard ratios (HR) of 1.6, 1.3, and 2.3 respectively. In NHL, only non-use of national protocols was a risk factor (HR 3.9). In ANLL and HD, none of the factors influenced survival. Survival of solid tumors (liver tumors, retinoblastomas) were significantly increased compared to after and before 2000 while survival for CNS tumors, neuroblastoma and bone tumors was not changed. Conclusions: The survival of childhood cancer in Thailand has markedly improved. Since implementation of national protocols, this is particularly the case for ALL and NHL. These results may be generalizable for the whole country.

• Korean Journal of Animal Reproduction
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• v.19 no.4
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• pp.265-270
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• 1996

This study was carried out to investigate on the survival rates and in vitro developmental rates of bisected bovine embryos by micromanipulator and micropipette. Bisected embryos were cultured for 1∼5 days in 20% FCS＋TCM-199 medium. Survival rate and in vitro developmental rate were defined as development rate on in vitro culture or FDA-test. The results are summarized as follows ; 1. The survival rates of intact or free zona pellucida of bisected embryos were 30.3 and 25.0%, respectively. And the survival rates of bisected embryos by micromanipulator and micropipette were 33.3 and 26.7%, respectively. The survival rate of bisected embryos was significantly lower than that of non-bisection embryos(65.0%). 2. The survival rates of bisection embryos in cultured for 12, 24, 48, 72 hrs with 20% FCS＋TCM-199 medium were 40.0, 30.0, 23.3 and 13.3%, respectively. 3. The in vitro developmental rates of intact of free zona pellucida of bisected embryos by micromainipulator and micropipettes were 33.3 and 26.7%, respectively. The survival rate of bisection embryos was significantly lower than that of non-bisection embryos(45.0%).

• Korean Journal of Artificial Intelligence
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• v.6 no.2
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• pp.11-15
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• 2018

Breast cancer is one of the leading causes of cancer related death among women. So prediction of overall survival status is important into decided in adjuvant treatment. Deep belief network is a kind of artificial intelligence (AI). We intended to construct prediction model by deep belief network using associated clinicopathologic factors. 103881 cases were found in the Korean Breast Cancer Registry. After preprocessing of data, a total of 15733 cases were enrolled in this study. The median follow-up period was 82.4 months. In univariate analysis for overall survival (OS), the patients with advanced AJCC stage showed relatively high HR (HR=1.216 95% CI: 0.011-289.331, p=0.001). Based on results of univariate and multivariate analysis, input variables for learning model included 17 variables associated with overall survival rate. output was presented in one of two states: event or cencored. Individual sensitivity of training set and test set for predicting overall survival status were 89.6% and 91.2% respectively. And specificity of that were 49.4% and 48.9% respectively. So the accuracy of our study for predicting overall survival status was 82.78%. Prediction model based on Deep belief network appears to be effective in predicting overall survival status and, in particular, is expected to be applicable to decide on adjuvant treatment after surgical treatment.