• 한국벤처창업학회:학술대회논문집
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• 2017.04a
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• pp.26-26
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• 2017

이 연구의 목적은 실제 창업하여 5년 이상 생존한 편의점이 최적의 입지유형에 위치한 것이 크다는 영향을 증명하는데 있다. 이 목적을 달성하기 위하여 서울 주요 지역의 5년 이상 생존 점포 사례를 본인과 지인의 사례 점포, A 메이저 프랜차이즈 편의점 직원이 제공한 자료를 토대로 연구 결과를 분석하고 실제 창업 생존률을 높이는데 도움을 주고자 한다. 실증분석결과, 첫째로 입지요인은 편의점 성과에 영향을 미치는 것으로 나타났다. 둘째, 최적의 입지유형에 위치한 점포는 5년 이상 생존하는데 영향을 주는 것으로 나타났다. 최적의 입지유형에 위치한 편의점 창업은 5년 이상 생존하는데 상당한 영향을 미치므로 입지유형에 대한 인식과 실전 적용은 필요한 것으로 나타났다. 전체 창업시장으로 보면 편의점과 같이 상품의 동질성이 높은 업종이나 위치에 중점을 둔 창업인 경우 까지 확대하여 창업가의 실패를 줄이고 장기적 생존률을 높일 수 있는 연구가 확대 되어야 할 것이다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.1
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• pp.66-73
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• 2007

일반 투자안의 의사결정에서와 마찬가지로 산업설비의 경제성 분석에서도 가장 중요한 결정 요소 중의 하나가 설비의 생존곡선 추정이다. 설비의 자산 가치가 감소하는 원인은 여러 가지가 있으나, 여러 원인 중 물리적 훼손이 과거의 산업설비에서는 가장 중요한 원인이었으므로 기존의 생존모형 분석에서는 lows 생존곡선을 이용하여 설비의 생존곡선을 추정하였다. 그러나 새로운 기술상의 변화로 인한 첨단 생산시스템의 설비교체 분석 시에는 적합지 않다. 따라서, 본 연구에서 제안된 혼합형 Weibull 함수를 이용하여 설비의 폐기 형태를 추정함으로써 설비들의 실제적인 생존곡선을 정확하게 파악할 수 있다.

• Korean Journal of Poultry Science
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• v.49 no.1
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• pp.15-23
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• 2022

We compared the degrees of vitality of 12 Korean native chicken breeds, such as Jaeraejong, Korean Rhode Island Red (Rhode), Korean White Leghorn, Korean Cornish (Cornish), and Korean Ogye breeds. The survival rate and telomere length were measured as vital markers. Telomere length was analyzed via quantitative fluorescence in situ hybridization method using the lymphocytes of 466 chickens. We found that the telomere length decreased linearly with increasing chronological age in all chicken breeds. Telomere length and telomere shortening rates (TSR) were significantly different among the chicken breeds after 20 weeks of age (P<0.01). Rhode had the longest telomere length and the lowest TSR, whereas Cornish had the shortest telomere length and the highest TSR. In terms of TSR, the telomere length of 50-week-old chickens was half of that of 8-week-old chickens. There was also a significant difference in survival rates among the breeds. Both Rhode and Korean Ogye had the highest survival rates, while Cornish had the lowest. There was a significant positive correlation between survival rate and telomere length, and telomere length in old age showed a higher correlation with survival rate than that in young age. Therefore, it is considered that TSR is more closely related to survival rate than the telomere length. Based on the telomere dynamics and survival rates of 12 Korean native chicken breeds, it was concluded that the Rhode breed and Cornish breed had the highest and lowest vitality, respectively.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.6
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• pp.67-78
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• 2015

The objective of this paper is to analyze survival rate and factors of FDI(Foreign direct investment) using FDI data of Ministry of Knowledge and Economy. Kaplan-Meier estimation was used. The result was as follows. M&A of FDI was much more risk than Greenfield FDI. .FDI to the IT-service industry was much more risk than FDI to the manufacturing industry. Partnership under 50% was much more risk than partnership over 50%. The accumulated survival rate of M&A was higher then Greenfield until fourth period but was lower than Greenfield after fourth period. The accumulated survival rate of M&A was lower than others from the first period to last period. There was no difference between Partnership under 50% and partnership over 50% to 4th period. After 4th period, Accumulated survival rate of partnership under 50% was higher than accumulated survival partnership over 50%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1269-1276
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• 2015

The mission capability of tank depends on its survivability. The survivability is ability for protection and tolerance by damage from threats. To improve the survivability of tank, we need an effectiveness analysis for loss of components, and accomplish performance enhancement using the result of analysis. In this paper, we develop a survivability analysis system for tank based on the importance. The importance numerically represents weight of each component which consisting of whole tank, also the importance is basic method of quantitative survivability analysis. To do this, we assign weight values to each component of tank, compose a weight tree, apply the importance calculation equation, and analyze the survivability of tank. Also we develop the system that consists of component structuralization and weight value setting program and survivability analysis and visualization program, and evaluate the system using implemented 3D CAD models of components of tank. The developed system apply to arrangement components.

• Journal of Technology Innovation
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• v.26 no.4
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• pp.98-121
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• 2018

This article analyzes the survival of Korean software firms from 1995 to 2015 by Cox regression model and product-limit method. The results show that survival rates are different for each sector: IT service, package software, game software and internet service. In addition, firm growth and investment in research and development positively affect software firm's survival, while slack resources negatively affect the software firm's survival. The implication of this study is that characteristics of the software industry and technologies should be taken into consideration in survival strategy of software firms and government policy. Previous research on survival analysis has been mainly conducted in the manufacturing industry or at the special circumstance such as the foreign exchange crisis of Korea in the late 1990s. The contribution of this study is that expanding the survival analysis to software firms in Korea which are becoming more important recently.

• The Korean Journal of Applied Statistics
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• v.35 no.1
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• pp.35-47
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• 2022

The receiver operating characteristic (ROC) curve was developed to quantify the classification ability of marker values (covariates) on the response variable and has been extended to survival data with diverse missing data structure. When survival data is understood as binary data (status of being alive or dead) at each time point, the ROC curve expressed at every time point results in time-dependent ROC curve and time-dependent area under curve (AUC). In particular, a follow-up study brings the change of cohort and incomplete data structures such as censoring and competing risk. In this paper, we review time-dependent ROC estimators under several contexts and perform simulation to check the performance of each estimators. We analyzed a dementia dataset to compare the prognostic power of markers.

• Journal of Embryo Transfer
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• v.14 no.1
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• pp.69-77
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• 1999

본 연구는 돼지 정액의 동결과정동안 flow cytometric 분석에 의한 정액내 생존정자의 비율을 조사하여 주관적으로 평가되는 활력 및 정상첨체율(normal apical ridge ; NAR)과 비교하여 정자의 손상과 생존성에 대한 적절한 평가법을 찾기 위하여 실시하였다. 동결과정 중 정액채취, 냉각, 예비동결 및 동결융해 후에 flow cytometric 분석에 의한 정자 생존율은 각각 93.0$\pm$3.6, 85.1$\pm$3.9, 28.9$\pm$6.8 및 26.1$\pm$5.9%이었다. 동결처리동안에 생존율은 예비동결 및 동결융해 후 가장 많은 정자사멸로 동결상태 이전의 생존율보다 유의적으로 낮게 나타났다. (p<0.05). 평가기법으로 정액 채취시 활력, NAR율 및 생존율을 조사한 결과 각각 91.0$\pm$4.2, 96.8$\pm$2.5 및 92.2$\pm$3.2%로 NAR율이 생존성 및 활력보다 높게 평가되었으며, 생존율이 활력보다 다소 높게 평가되었다. 그러나 동결융해 후에는 각각 44.0$\pm$8.9, 49.0$\pm$7.9 및 35.6$\pm$9.7%로 활력이 생존율보다 다소 높게 평가되었다. 전체적으로 NAR율은 활력은 생존율보다 높게 평가되었으며, SYBR-14 / PI(propidium iodide) 이중형광염색법에 의한 flow cytometric 평가법으로 생존율은 동결되지 않은 정액에서의 활력 및 NAR 평가보다 다소 민감하게 나타났다. 이러한 결과로 미루어보아 SYBR-14 / PI 형광염색에 의한 flow cytometry의 생존성 평가는 동결되지 않은 정액의 평가방법으로는 적절하지만 동결된 정액의 생존성 평가는 부적절한 것으로 사료되었다.

• The Korean Journal of Applied Statistics
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• v.27 no.6
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• pp.891-907
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• 2014

This article is concerned with one of the most important prior distributions for Bayesian analysis of survival and event history data, called Beta processes, proposed in Hjort (1990). We review the current state of the art of beta processes and their application to survival analysis. Relevant methodological and practical areas of research that we touch on relate to constructions, posterior distributions, large-sample properties, Bayesian computations, and mixtures of Beta processes.

• The Korean Journal of Applied Statistics
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• v.23 no.4
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• pp.705-713
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• 2010

Predicting survival from microarray data is not easy due to the problem of high dimensionality of data and the existence of censored observations. Also the limitation of individual gene analysis causes the shift of focus to the level of gene sets with functionally related genes. For developing a survival prediction model based on pathway information, the methods for selecting a supergene using principal component analysis and testing its significance for each pathway are discussed. Besides, the performance of gene filtering is compared.