• Journal of the Korean Data and Information Science Society
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• v.25 no.2
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• pp.327-336
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• 2014

Recurrent event data occurs when a subject experiences same type of event repeatedly and is found in various areas such as the social sciences, Economics, medicine and public health. To analyze recurrent event data either a total time or a gap time is adopted according to research interest. In this paper, we analyze recurrent event data with incomplete observation gap using a gap time scale. That is, some subjects leave temporarily from a study and return after a while. But it is not available when the observation gaps terminate. We adopt an interval censoring mechanism for estimating the termination time. Furthermore, to model the association among gap times of a subject, a frailty effect is incorporated into a model. Programs included in Survival package of R program are implemented to estimate the covariate effect as well as the variance of frailty effect. YTOP (Young Traffic Offenders Program) data is analyzed with both proportional hazard model and a weibull regression model.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5097-5099
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• 2012

Objective: To assess associations of Type II DM with hepatocellular carcinoma occurrence in Nepal. Materials and Methods: This case control study was carried out using data retrieved from the register maintained in the Department of Biochemistry of Nepalese Army Institute of Health Sciences between 1st January, 2012, and 31st August, 2012. The variables collected were age, gender, HbA1c. All biochemical parameters were analyzed in the Central Laboratory of our hospital by standard validated methods. One way ANOVA was used to examine the statistical significant difference between groups with the LSD post-hoc test for comparison of means of case groups. Odds ratios (OR) were calculated using simple logistic-regression analysis. Results: Etiological factors for HCC were HBV, HCV, alcohol and cryptogenic cirrhosis. The highest age group belonged to the etiological category of HCV with a mean of $71.9{\pm}3.6$ (CI 69.3, 74.5) years and the lowest age group to the etiological category of HBV with $61.7{\pm}5.3$(CI 57.9, 65.5) years. The main imperative basis of HCC in present study was HCV (39.5%) and second most significant cause of HCC was alcohol (26%). Glycated hemoglobin was found to be more in males with HCC (7.9%) as compared to females (7.3%). The percentage of Type II diabetes mellitus was greater in HCC patients when compared to controls. This difference was statistically significant with an odd ratio of 4.63 (p<0.001). Conclusion: Type II DM influences incidence, risk of recurrence, overall survival, and treatment-related complications in HCC patients.

• Radiation Oncology Journal
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• v.31 no.3
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• pp.111-117
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• 2013

Purpose: To determine whether the maximum standardized uptake value (SUV) of [$^{18}F$] fluorodeoxyglucose uptake by positron emission tomography (FDG PET) ratio of lymph node to primary tumor (mSUVR) could be a prognostic factor for node positive non-small cell lung cancer (NSCLC) patients treated with definitive radiotherapy (RT). Materials and Methods: A total of 68 NSCLC T1-4, N1-3, M0 patients underwent FDG PET before RT. Optimal cutoff values of mSUVR were chosen based on overall survival (OS). Independent prognosticators were identified by Cox regression analysis. Results: The most significant cutoff value for mSUVR was 0.9 with respect to OS. Two-year OS was 17% for patients with mSUVR > 0.9 and 49% for those with mSUVR ${\leq}0.9$ (p = 0.01). In a multivariate analysis, including age, performance status, stage, use of chemotherapy, and mSUVR, only performance status (p = 0.05) and mSUVR > 0.9 (p = 0.05) were significant predictors of OS. Two-year OS for patients with both good performance (Eastern Cooperative Oncology Group [ECOG] ${\leq}1$) and mSUVR ${\leq}0.9$ was significantly better than that for patients with either poor performance (ECOG > 1) or mSUVR > 0.9, 23% (71% vs. 23%, p = 0.04). Conclusion: Our results suggested that the mSUVR was a strong prognostic factor among patients with lymph node positive NSCLC following RT. Addition of mSUVR to performance status identifies a subgroup at highest risk for death after RT.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.2
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• pp.68-75
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• 2007

After reports on regression of cancer in humans and animals infected with microbial pathogens date back more than 100 years, much effort has been spent over the years in developing a wild type or attenuated bacterial and purified bacterial proteins for the treatment of cancer. Pseudomonas aeruginosa exotoxin A (ETA) is known to inhibit cell growth and trigger significant cell death in various cancer cells. Although ETA induces apoptosis of cancer cells, its exact mechanism of action is not known yet. Four different assays were performed in this study: morphological assessment of apoptotic cells, cell cytotoxity, annexin-V binding assay, and cell cycle analysis. The proliferation and survival of the K-562 cells treated with ETA were decreased in a dose dependent manner. In addition, the apoptotic body of K-562 cells was induced by ETA treatment in a dose dependent manner. The ETA-induced apoptosis was confirmed by annexin-V binding assay. Flow cytometric analysis was examined to ascertain whether ETA could arrest the cell cycle at the sub-G1 phase. Our results suggest that P. aeruginosa ETA inhibits cell growth and induces apoptosis in human leukemia K-562 cells.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3465-3472
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• 2009

The aims of this study is to medical record data warehouse which had been collected from hospital information systems. continuous patient 2,118 60.5%, informally patient 1,385 39.5%. In using survival factors sex, age, area, insurance, admission-course, medical treatment, out-patient lesson, out-patient form, conference diagnosis, operation, cancer, medical reservation. As a result of making a predictive modeling using the logistic regression, the fitness of the predictive modeling of informally patient was 66.0% and neural network, the predictive was 66.72% and CHAID, the predictive was 63.25%, which is a data mining. The expected modeling of the informally patients, the hospital through the continuous patient management and trust of hospital.

• The Journal of the Korea Contents Association
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• v.12 no.11
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• pp.398-411
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• 2012

Recently, the hotel business requires to secure various client bases and accompany proper marketing and advertising activities for survival and development. Media PPL has been popular as an effective method to meet these requirements. Many studies have been practiced about the effect of media PPL marketing. This study was practiced to confirm the effect of the hotel place marketing using media PPL and the involvement for character in PPL. The following 4 assumptions are established for these purposes. The first confirms the impact relation between media PPL and hotel image. The second confirms whether the involvement for characters in media PPL influences the impact relation between media PPL and hotel image. The third confirms the impact relation between hotel image and purchasing behaviors. And the last confirms whether the involvement for characters in media PPL influences the impact relation between hotel image and purchasing behaviors. In order to analyze the assumptions established for this study, A questionnaires is carried out and factor analysis, reliability analysis and regression analysis are performed with them. According to the results of these analyses, all of 4 established assumptions are partly accepted.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.723-736
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• 2013

The importance of lapse rate is highly increasing due to the introduction of Cash Flow Pricing system, non-refund-of-reserve insurance policy, and IFRS (International Financial Reporting System) to the Korean insurance market. Researches on lapse rate have mainly focused on simple data analysis and regression analysis, etc. However, lapse rate can be analyzed by survival analysis and can be well explained in terms of several covariates with Cox proportional hazard model. Guaranteed minimum benefits embedded in variable annuities require more elegant statistical analysis of lapse rate. Hence, this paper analyzes data of policyholders with variable annuities by using Cox proportional hazard model. The key variables of policy holder that influences the lapse rate are payment method, premium, lapse insured to term insured, reserve-GMXB ratio, and age.

• The Journal of Information Systems
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• v.23 no.2
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• pp.67-90
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• 2014

Today, the company is trying to improve for business performance through the optimization of corporate resources. Most companies set up new strategy for obtaining competitive advantage for survival in rapid changes of the global business environment. IT has an important role to reduce cost and to increases business performance such as increasing sales, improving business skills and corporate image, etc. in the corporate environment. The development and use of IT resource is recognized as essential in connection with the business strategy. Most companies tried to establish the strategic use of information systems to gain competitive advantage. IT resource management is not clear in a tangible result of the business. The purpose of this study is to find out the relationship between IT competency and organizational performance through the mediating effect of strategic use of IS. IT competency consists of IT human resource, IT infrastructure, and IT vendor management. In direct relationship between three IT competence factors and organizational performance, the results of multiple regression analysis showed that IT human resource and IT vendor management are important determinants to influence organizational performance. The additional analysis for mediating effect of strategic use of IS showed that it has mediated the relationship between IT competency factors and organizational performance. This results give us an implication, not only the importance of IT competency development, but also the importance of strategic alignment of strategic use of IS with business strategy.

• The Korean Journal of Mycology
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• v.34 no.1
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• pp.34-38
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• 2006

To assess the effects of proton beam on radiation sensitivity of the basidiospore and mycelium of oyster mushroom (Pleurotus ostreatus), the $D_{10}$ values and $L_{50}$ (lethal 50%) values were analysed. By the proton beam radiation, the survival rate and germination rates increased at the dose of $10\;Gy{\sim}100\;Gy$ and then decreased significantly over 500 Gy. $L_{50}$ values of basidiospore and mycelium of Pleurotus ostreatus were over 500 Gy and 400 Gy, respectively. $D_{10}$ values were calculated from linear regression formulae ($D_{10}\;=\;-1/slope(b)$, y = a + bx) as 750 Gy and 1,250 Gy, respectively. Based on our experiment, the optimum dose of proton beam as a mutation source would be between from 500 Gy to 750 Gy for basidiospores and from 400 Gy to 1000 Gy for mycelium of oyster mushroom.

• Journal of Preventive Medicine and Public Health
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• v.40 no.4
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• pp.329-335
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• 2007

Objectives : To identify the effects of supplemental private health insurance on health care utilization and expenditure under the mandatory National Health Insurance(NHI) system in Korea. Methods : The data were collected by the National Cancer Center in Korea. Cancer patients who were newly diagnosed with stomach (ICD code, C16), lung(C33-C34), liver (C22), colorectal cancer(C18-C20) or breast(C50) cancer were included as study subjects. Data were gathered using a structured questionnaire from face-to-face interviews, the hospital Order Communication System (OCS) and medical records. Clinical, socio-demographic and private health insurance related factors were also gathered. The differences of health care utilization and expenditure were compared between those who have private health insurance and those who do not using t-test and multivariable regression analysis. Results : Individuals with private health insurance spent larger inpatient costs than those without, but no differences were found in utilization in other service such as hospital admissions, hospital days and physician visits. Conclusions : We found that private health insurance exerts a significant effect on the health care expenditure in inpatient service. These study results can provide a rational basis to plan a national health policy regarding private health insurance. Further studies are needed to investigate the impacts of private health insurance on cancer patients' outcomes and survival rates.