• Communications for Statistical Applications and Methods
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• 제28권5호
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• pp.411-424
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• 2021

Inference following two-stage adaptive designs (also known as two-stage randomization designs) with survival endpoints usually focuses on estimating and comparing survival distributions for the different treatment strategies. The aim is to identify the treatment strategy(ies) that leads to better survival of the patients. The objectives of this study were to assess the performance three commonly cited methods for estimating survival distributions in two-stage randomization designs. We review three non-parametric methods for estimating survival distributions in two-stage adaptive designs and compare their performance using simulation studies. The simulation studies show that the method based on the marginal mean model is badly affected by high censoring rates and response rate. The other two methods which are natural extensions of the Nelson-Aalen estimator and the Kaplan-Meier estimator have similar performance. These two methods yield survival estimates which have less bias and more precise than the marginal mean model even in cases of small sample sizes. The weighted versions of the Nelson-Aalen and the Kaplan-Meier estimators are less affected by high censoring rates and low response rates. The bias of the method based on the marginal mean model increases rapidly with increase in censoring rate compared to the other two methods. We apply the three methods to a leukemia clinical trial dataset and also compare the results.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.136-146
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• 2011

This study provides first-hand proteomic data on the survival strategy of Anabaena sp. PCC 7120 when subjected to long-term iron-starvation conditions. 2D-gel electrophoresis followed by MALDI-TOF/MS analysis of iron-deficient Anabaena revealed significant and reproducible alterations in ten proteins, of which six are associated with photosynthesis and respiration, three with the antioxidative defense system, and the last, hypothetical protein all1861, conceivably connected with iron homeostasis. Iron-starved Anabaena registered a reduction in growth, photosynthetic pigments, PSI, PSII, whole-chain electron transport, carbon and nitrogen fixation, and ATP and NADPH content. The kinetics of hypothetical protein all1861 expression, with no change in expression until day 3, maximum expression on the $7^{th}$ day, and a decline in expression from the $15^{th}$ day onward, coupled with in silico analysis, suggested its role in iron sequestration and homeostasis. Interestingly, the up-regulated FBP-aldolase, Mn/Fe-SOD, and all1861 all appear to assist the survival of Anabeana subjected to iron-starvation conditions. Furthermore, the $N_2$-fixation capabilities of the iron-starved Anabaena encourage us to recommend its application as a biofertilizer, particularly in iron-limited paddy soils.

• 복식문화연구
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• 제8권1호
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• pp.77-86
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• 2000

The purpose of this study is to identify the nature and trend of multinational corporations and to examine strategies for survival of local companies in newly-rising markets which stand against huge multinational corporations, through case study. This research has been done by the literature review of the articles, books and the case study. The results were as follow : First, if the pressure for the globalization of a industry is low and the possibility of overseas transfer of the competitive property of corporations are bare, the intensive strategy for the protection of a national market can be used against the invasion of a multinational corporations. Second, if the pressure for the globalization is still low and the retaining property can be transferred to abroad, a company can be expended to several foreign markets in the limited scope, using the success in a national market as a stepping-stone. Third, In case the pressure for the globalization is high and the competitive property of corporations are effective only in a national market, corporations can survive individually and continuously through the reorganization of corporation's property, which is the survival strategy against multinational corporations. Forth, if the pressure for the globalization is high and the property of corporations can be transferred to abroad, it is possible for corporations to compete with the multinational corporations confidently.

• Journal of Chest Surgery
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• 제52권4호
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• pp.195-204
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• 2019

Lobectomy is considered the standard strategy for early-stage non-small cell lung cancer (NSCLC). However, sublobar resection for NSCLC has recently received increased attention. The objective of this study was to compare 5-year survival, recurrence-free survival, postoperative mortality, and postoperative morbidities in patients who received segmentectomy versus those who received lobectomy through a meta-analysis. Sixteen studies were included and the combined hazard ratios or odds ratios were calculated. The results revealed that the 5-year survival rate after segmentectomy was comparable to that of lobectomy for stage IA NSCLC. However, segmentectomy for stage I NSCLC had lower rates of postoperative mortality and morbidities than lobectomy.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2893-2900
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• 2014

Background: Statistical methods are very important to precisely measure breast cancer patient survival times for healthcare management. Previous studies considered basic statistics to measure survival times without incorporating statistical modeling strategies. The objective of this study was to develop a data-based statistical probability model from the female breast cancer patients' survival times by using the Bayesian approach to predict future inferences of survival times. Materials and Methods: A random sample of 500 female patients was selected from the Surveillance Epidemiology and End Results cancer registry database. For goodness of fit, the standard model building criteria were used. The Bayesian approach is used to obtain the predictive survival times from the data-based Exponentiated Exponential Model. Markov Chain Monte Carlo method was used to obtain the summary results for predictive inference. Results: The highest number of female breast cancer patients was found in California and the lowest in New Mexico. The majority of them were married. The mean (SD) age at diagnosis (in years) was 60.92 (14.92). The mean (SD) survival time (in months) for female patients was 90.33 (83.10). The Exponentiated Exponential Model found better fits for the female survival times compared to the Exponentiated Weibull Model. The Bayesian method is used to obtain predictive inference for future survival times. Conclusions: The findings with the proposed modeling strategy will assist healthcare researchers and providers to precisely predict future survival estimates as the recent growing challenges of analyzing healthcare data have created new demand for model-based survival estimates. The application of Bayesian will produce precise estimates of future survival times.

• 식품기술
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• 제26권3호
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• pp.210-223
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• 2013

• Journal of Korean Neurosurgical Society
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• 제61권3호
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• pp.393-401
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• 2018

The prognosis of brain tumors in children has improved for last a few decades. However, the prognosis remains dismal in patients with recurrent brain tumors. The outcome for infants and young children in whom the use of radiotherapy (RT) is very limited because of unacceptable long-term adverse effect of RT remains poor. The prognosis is also not satisfactory when a large residual tumor remains after surgery or when leptomeningeal seeding is present at diagnosis. In this context, a strategy using high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) has been explored to improve the prognosis of recurrent or high-risk brain tumors. This strategy is based on the hypothesis that chemotherapy dose escalation might result in improvement in survival rates. Recently, the efficacy of tandem HDCT/auto-SCT has been evaluated in further improving the outcome. This strategy is based on the hypothesis that further dose escalation might result in further improvement in survival rates. At present, the number of studies employing tandem HDCT/auto-SCT for brain tumors is limited. However, results of these pilot studies suggest that tandem HDCT/auto-SCT may further improve the outcome. In this review, we will summarize our single center experience with tandem HDCT/auto-SCT for recurrent or high-risk brain tumors.

• 경영과학
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• 제28권3호
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• pp.47-60
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• 2011

While the literature is replete with arguments that corporate strategy, structure, and culture independently matter in explaining the growth and survival of firms, little theoretical and empirical attention has been devoted to understanding how the three organizational factors develop over time in interaction. Through in-depth case study, we examine the POSCO's historical development with respect to the strategy-structure-culture interface. Furthermore, by looking at the POSCO's longitudinal financial data we gain insight into whether the aligned evolution of strategy, structure, and culture is associated with performance.

• 대한안전경영과학회지
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• 제7권2호
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• pp.107-121
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• 2005

The growth and survival of a enterprise depend upon its proper strategic capability against the rapid change in environment. The enterprise that well accommodates the changing environment and properly uses the resources will continue its growth. The problems in accommodating business environment are how to focus the limited manufacturing strategy on certain point. The manufacturing innovation program receives a large effect in the manufacturing strategy. Consequently it follows the degree with manufacturing innovation program agrees with the manufacturing strategy determine the maximization of the manufacturing and management performance.

• Journal of Gastric Cancer
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• 제11권1호
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• pp.31-37
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• 2011

Purpose: We performed this study to evaluate the clinical presentation as well as the proper surgical intervention for ovarian metastasis from gastric cancers and these tumors were identified during postoperative follow-up. This will help establish the optimal strategy for improving the survival of patients with this entity. Materials and Methods: 22 patients (3.2%) with ovarian metastasis were noted when performing a retrospective chart review of (693) females patients who had undergone a resection for gastric cancer between 1981 and 2008. The covariates used for the survival analysis were the patient age at the time of ovarian relapse, the size of the tumor, the initial TNM stage of the gastric cancer, the interval to metastasis and the presence of gross residual disease after treatment for Krukenberg tumor. The cumulative survival curves for the patient groups were calculated with the Kaplan-Meier method and they were compared by means of the Log-Rank test. Results: The average age of the patients was 48.6 years (range: 24 to 78 years) and the average survival time of the 22 patients was 18.8 months (the estimated 3-year survival rate was 15.8%) with a range of 2 to 59 months after the diagnosis of Krukenberg tumor. The survival rate for patients without gross residual disease was longer than that of the patients with gross residual disease (P=0.0003). In contrast, patient age, the size of ovarian tumor, the initial stage of gastric adenocarcinoma, the interval to metastasis and adjuvant chemotherapy were not prognostic indicators for survival after the development of ovarian metastasis. Conclusions: Early diagnosis and complete resection are the only possible hope to improve survival. As the 3-year survival rate after resection of Krukenberg tumor is 15.8%, it seems worthwhile to consider performing tumorectomy as the second cytoreduction.