• Korean Journal of Social Welfare
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• v.68 no.2
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• pp.107-130
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• 2016

This study is aimed at the exploratory research on the influence of the obligation of extension of the retirement age on the baby boom generation. The basic question of this study is about which of the baby boom generation can get how much benefit according as the extension of the retirement age becomes compulsory. The extension of the retirement age is the system that can be applied to regular full-time workers. Accordingly, this study is intending to analyze the characteristics of the workers having a high likelihood for benefits from extension of the retirement age by tracing the economic activity state and labor history of the baby boomers. For this purpose, this study looked into the change of the economic activity state by age cohort of the male baby boomers based on the data for the Korea Labor Panel's 4th(2001) & 17th(2014)year. Using Survival analysis, this study also analyzed who will continue to remain as a regular full-time wage earner. As the result of the analysis, it was found that the more the cohort ages of baby boomers increased, the smaller the probability of remaining as a regular full-time wage earner, and the group who can get benefits from extension of the retirement age was predicted to account for only 11.4% level among the baby boomers. In addition, the result showed that there was a high likelihood of getting more benefits from extension of the retirement age when the baby boomers worked for the government-invested institution, corporate bodies, and government organizations rather than working for private enterprises. Thus, it can be safely said that there might appear a generational conflict due to extension of the retirement age in that such jobs coincide with the ones favored by the rising generation.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.36-41
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• 1999

Purpose : We reviewed the treatment results for the patients with locally recurrent rectal carcinoma. The object was to evaluate the treatment outcome and to identify the prognostic factors influencing the survival. Methods and Materials: Twenty-eight patients with locally recurrent rectal carcinoma treated principally with external-beam radiation therapy between 1982 to 1996 in the Department of Radiation Oncology at Paik and Hanyang Hospital were reviewed retrospectively Of these, 17 patients had initially abdominoperineal resection, 9 had low anterior resection, and 2 had local excision. No patients had received adjuvant radiation therapy for the primary disease. There were 14 men and 14 women whose ages ranged from 31 to 72 years (median age:54.5). Median time from initial surgery to the start of radiation therapy for local recurrence was 11 months (4~47 months). Radiation therapy was given with total doses ranging from 27 to 64.8 Gy (median=51.2 Gy). Results : The median survival was 16.7 months. The 2-year and 5-year survival rates were 20.1%, 4.1% respectively. Upon multivariate analysis, overall survival was positively correlated with duration of intervals from initial surgery to local recurrence (P=0.039). Relief of pelvic symptoms was achieved in 17 of 28 patients (60.7%). Pain and bleeding responded in 40% and 100% of patients, respectively Conclusions : Patients with locally recurrent rectal carcinoma treated with radiotherapy have benefited symptomatically, and might have increased survivals with a small chance of cure. But, patient were rarely cured (median survival : 10 months, 5-year survival : less than 5%). Overall survival was positively correlated with long intervals from initial surgery to local recurrence. Future efforts should be directed to the use of effective therapy for patients with locally recurrent rectal carcinoma and adjuvant therapy for patients with rectal cancer to reduce the incidence of pelvic recurrence.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.1
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• pp.10-19
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• 2015

Purpose: The aim of the present study was to evaluate the long-term survival of implants retrospectively and determine the risk factors associated with implant failure. Materials and Methods: Of all implants that were placed at the Department of Periodontology of the Dental Hospital of Gangneung-Wonju National University from January 1998 to December 2012, 2265 implants that were followed up until June 2013 were included in this study. Data were collected from clinical and radiographic examinations from previous visits. The information gathered included gender, age, smoking status, implant diameter, implant length, surface of implant, location of implant within the dental arch, surgical techniques and existence of complications. Results: The survival rate before loading was 98.9%. The cumulative survival rate after 5 years of loading was 97.2%, and after 15 years of loading was 95.2%. In a simple logistic regression analysis, gender (P = 0.016), smoking status (P = 0.001), location of implant (P = 0.020) and existence of complications (P = 0.002) were statistically associated with implant failure and included in the multiple regression analysis. As a result of multiple logistic regression analysis, the variables statistically associated with implant failure (P < 0.05) were smoking status (P = 0.049) and existence of complications (P < 0.001). Conclusion: The cumulative survival rate of dental implants after 15 years of loading was 95.2% and that the variables statistically associated with implant failure were smoking status and existence of complications.

• Journal of Hospice and Palliative Care
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• v.18 no.1
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• pp.51-59
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• 2015

Purpose: Predicting life expectancy of terminally ill cancer patients is very important. In many studies, ferritin is detected at higher levels in the sera of cancer patients, and higher ferritin level correlates with aggressiveness of disease and poor outcomes of patients. This study evaluated a prognostic role of serum ferritin levels in terminally ill cancer patients. Methods: This study enrolled 65 terminally ill cancer patients from March through June 2012. We assessed routine laboratory findings including serum ferritin levels as well as demographic and clinical characteristics of the patients. To examine the association between serum ferritin levels and patient's characteristics, we used Spearman's correlation analysis, Wilcoxon's rank sum test or Kruskal-Wallis test, as appropriately. For multivariate analysis, Cox's proportional hazard regression model was used to evaluate significance of serum ferritin levels as a prognostic factor. Results: A negative correlation between serum ferritin levels and survival time was found. After adjusting for sex, age, performance status, creatinine levels and white blood cell counts, serum ferritin levels were significantly associated with survival time. Conclusion: Even at the very end of life of terminal cancer patients, serum ferritin levels were an independent prognostic factor for survival.

• Journal of Hospice and Palliative Care
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• v.17 no.2
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• pp.57-65
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• 2014

Purpose: Since most terminally ill cancer patients die of multiple organ failure, plasma endotoxin concentration levels may be used to predict the life expectancy. This study was performed to evaluate the clinical significance of endotoxin level in plasma as a prognostic factor for survival in patients with terminal cancer. Methods: This study was conducted with 56 terminally ill cancer patients, above 20 years old, from April 2009 through October 2009. Demographic characteristics, Karnofsky performance status, and survival time were evaluated. We analyzed blood levels of white blood cell hemoglobin, hematocrit, aspartate aminotransferase, alanine aminotransferase, c-reactive protein, total bilirubin and endotoxin in each patient. Results: We considered following variable for univariate analysis: plasma endotoxin level, sex, age, WBC, hemoglobin, hematocrit, AST, ALT, total bilirubin, CRP and severity of pain. Univariate analysis did not show a significant association between plasma endotoxin level and survival time. However, in a multivariate analysis with factors that were found to be significantly associated with survival sex, WBC count and total bilirubin level in univariate analysis, high levels of plasma endotoxin and short survival time were significantly related. Conclusion: Plasma endotoxin level could be used as a prognostic factor to predict the life expectancy of terminally ill cancer patients.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.13 no.4
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• pp.1-12
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• 2018

During few decades, Korean economy has been growing with heavy and manufacturing industries. However, the economy meets limitations of growth rate, and employment rate. The Korean government has been trying to overcome these limitations using development of venture businesses and re-organization of industrial ecosystem. These efforts make high survival rate of recent venture companies. There are previous researches about relation between characteristics of entrepreneur and managerial performance, there are several limitations. Firstly, most of papers were based on survey with specific region or industry. Secondly, related researches were carried out with unable to distinguish among firm's survival periods. This paper uses the '2017 Survey of Korea Venture Firms' data that is approved by the Korean government. This data includes whole industries and survival periods. The aim of this research is finding the effect of characteristics of entrepreneur on managerial performance of venture firms by different survival periods using data envelopment analysis (DEA). If entrepreneur has doctoral degree, the firm's managerial performance is lower than bachelor degree. In addition, over 10 years of working career, and joint-venture have positive effect on firm's performance. This paper can provide valuable information to venture related policy makers and investment decision makers.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.507-513
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• 2012

This research was performed to evaluate the superparamagnetic iron oxide nanoparticles'(SPIONs) cell toxicity and to measure the radiation cell survival curve changes of SPIONs-uptake glioblastoma multiforme cells. The results could be practically used as the fundamental data to ameliorate proton beam cancer therapy, for example, providing necessary GBM treatment dose in the proton beam therapy when the therapy takes advantage of SPIONs. The assessment of the toxicological evaluation of synthesized SPIONs was accomplished by MTT assay as an in vitro experiment. The results showed no meaningful differences in the cell survival rate at the $1-100{\mu}g/ml$ SPIONs concentrations, but the cell toxicity was shown as the cell survival rate decreased up to 74.2% at the $200{\mu}g/ml$ SPIONs concentration. Then, we measured each radiation cell survival curve for U373MG cells and SPIONs-uptake U373MG cells with 0~5 Gy of proton beam irradiations. It is learned from the analysis of the experimental results that the SPION-uptake cells' radiation survival rate was more rapidly decreased as the irradiation dose increased. In conclusion we confirmed that SPIONs-uptake in U373MG cells induces cell death at the much less dose than the lethal dose of SPION-non-uptake cell. This research shows that the therapeutic efficacy of glioblastoma multiforme treatment in proton beam therapy can be improved by SPIONs targeting to the GBM cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.3
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• pp.310-317
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• 2019

The purpose of this retrospective study was to evaluate the survival rate of composite resin restorations in permanent first molars in pediatric patients focusing on the influence of risk factors related to patients and teeth. 172 patients (6 - 12 years old) who had their permanent first molars restored with composite resin from July 2010 to July 2012 were investigated. From the dental records, the influence of the risk factors on the survival of restorations was assessed. Location of teeth, classification of cavities, patients' age and caries risk were included as risk factors in this study. The caries risks of patients were evaluated by the value of the decayed-missing-filled teeth index with the records of patients taken at 5 years old. Among 354 restorations, 272 restorations retained and 82 restorations were replaced. The overall cumulative survival rate at 5 years was 73.9%. The main reason for replacement of restorations was secondary caries (81.7%). Patients with older age group and with lower caries risk group showed higher survival rate of restorations. No statistically significant influence was detected between the survival rates and the possible risk factors : location of teeth, patients' age and caries risk. The survival rate of restorations was significantly affected by the classification of the cavities (p = 0.002).

• Journal of the Economic Geographical Society of Korea
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• v.23 no.4
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• pp.425-437
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• 2020

In Korea, the proportion of self-employed and unpaid family workers is relatively higher than other OECD countries and the operation periods of their businesses are generally shorter than others. This indicates frequent startups and closures and thus unstable employment status and income, which inevitably generates huge social costs. Restaurants are a representative business that self-employed workers easily enter and their 5-year survival rate is found to be lower than 20%. This is shorter survival period than other business sectors. This study aims to examine the associations of transport accessibility with restaurants' survival in Gwangju metropolitan area. Convenient location has been known to be a crucial factor for sales improvements and longer operation and such location is closely linked with good transport accessibility. Results from survival analysis on empirical data show that better access to road networks is significantly associated with longer survival of restaurants though subway accessibility is not. This can be explained by low modal share of subway in the study area and at the same time, requires further case studies where more developed and matured subway systems are in operation.

• 대한예방의학회:학술대회논문집
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• 1997.10a
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• pp.185-198
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• 1997