• 제목/요약/키워드: Survival Probability

검색결과 249건 처리시간 0.024초

신뢰성 개념을 이용한 적정 포장 수명분포 선정 (Selection of Probability Distribution of Pavement Life Based on Reliability Method)

  • 도명식;권수안
    • 한국도로학회논문집
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    • 제12권1호
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    • pp.61-69
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    • 2010
  • 본 연구에서는 신뢰성 개념을 도입하여 최근 10년간의 수원과 의정부 지역의 일반국도 아스팔트 포장구간의 수명 데이터를 기반으로 적합한 모수적 수명분포 선정과 헤저드 함수 및 생존확률을 추정하였다. 최적 수명분포형을 찾기 위해 확률지 개념을 이용하여 모수를 추정하였으며 적정 확률분포형태의 결정은 Anderson-Darling 통계값을 이용하였다. 그 결과 분석 대상 지역 포장의 수명 데이터를 가장 잘 설명하는 수명분포는 대수정규(Lognormal)분포인 것으로 분석되었다. 또한 본 연구에서 제안한 대수정규분포에 의해 추정된 생존확률함수는 실제 관측값과 차이가 거의 없음을 확인하였다. 본 연구에서 제안한 신뢰성 개념을 이용한 분석 방법은 포장관리 및 유지보수 데이터가 축적되어감에 따라 비교적 용이하게 계속 update가 가능하며 따라서 보다 정확한 포장수명에 대한 신뢰도 값에 접근해 갈 수 있는 이점이 있다.

The Impact of Government Innovation Subsidies on the Survival of SMEs in Korea

  • Kim, Sangsin
    • STI Policy Review
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    • 제9권1호
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    • pp.55-76
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    • 2018
  • This study analyzed the effect of the government R&D subsidy program on long-term firm survival. In order to estimate the average treatment effect for the treated group, we used the survival analysis and matching method by constituting a comprehensive dataset of more than 90,000 observations. The analysis results show that the government R&D subsidy has a negative impact on long-term firm survival. In particular, not only the subsidy does not have a statistically significant effect on firm survival in the relatively short-term, the survival probability of the subsidized firms is statistically significantly lower than the non-subsidized firms after six years. These results can be seen as weakening the justification of government R&D support. There may be problems in the subsidy policy itself and the process of selection of subsidy awardees; however, the more fundamental problem is that the subsidy policy is concluded as the one-time event. Admittedly, it would be difficult for the government to precisely manage the subsidized projects over a long term period. However, in the case of a project in which short-term performance is detected, it would be necessary to provide a step-by-step support to strengthen the firm's competitiveness through further support and continuous development of performance. Of course, mid- and long-term evaluations of subsidy support policy should be performed in parallel with such phased support.

Family Firm Governance and Long-term Corporate Survival: Evidence from Korean Listed Firms

  • Ahn, Se-Yeon
    • 아태비즈니스연구
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    • 제12권1호
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    • pp.25-39
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    • 2021
  • Purpose - This study aims to examine whether family firm governance is related to long-term corporate survival. To find out whether and why family firms have higher chances of long-term survival compared to non family firms, this study analyzes the relationship between some governance characteristics that are prevalent in family firms and corporate long-term viability. Design/methodology/approach - This study utilizes a sample of 285 family firms listed on the Korea Stock Exchange (KSE) to probe the influence of governance characteristics on corporate survival. This study conducts Cox proportional hazard regression analysis to estimate the influences on the survival duration. Findings - The results indicate that firms with particular governance characteristics show higher long-term survivability. Specifically, the probability of firm's long-term survival is increased when the CEO is the largest shareholder, which may be related to CEO's stewardship attitudes. Research implications or Originality - This study has significance in that it examines the direct causal variables that enhance long-term corporate viability through a large scale empirical examination. Also, the study findings provide some clues as to why certain family firms outlive non-family firms.

Estimating the Five-Year Survival of Cervical Cancer Patients Treated in Hospital Universiti Sains Malaysia

  • Razak, Nuradhiathy Abd;Khattak, M.N.;Zubairi, Yong Zulina;Naing, Nyi Nyi;Zaki, Nik Mohamed
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권2호
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    • pp.825-828
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    • 2013
  • Objective: The objective of this study was to determine the five-year survival among patients with cervical cancer treated in Hospital Universiti Sains Malaysia. Methods: One hundred and twenty cervical cancer patients diagnosed between $1^{st}$ July 1995 and $30^{th}$ June 2007 were identified. Data were obtained from medical records. The survival probability was determined using the Kaplan-Meier method and the log-rank test was applied to compare the survival distribution between groups. Results: The overall five-year survival was 39.7% [95%CI (Confidence Interval): 30.7, 51.3] with a median survival time of 40.8 (95%CI: 34.0, 62.0) months. The log-rank test showed that there were survival differences between the groups for the following variables: stage at diagnosis (p=0.005); and primary treatment (p=0.0242). Patients who were diagnosed at the latest stage (III-IV) were found to have the lowest survival, 18.4% (95%CI: 6.75, 50.1), compared to stage I and II where the five-year survival was 54.7% (95%CI: 38.7, 77.2) and 40.8% (95%CI: 27.7, 60.3), respectively. The five-year survival was higher in patients who received surgery [52.6% (95%CI: 37.5, 73.6)] as a primary treatment compared to the non-surgical group [33.3% (95%CI: 22.9, 48.4)]. Conclusion: The five-year survival of cervical cancer patients in this study was low. The survival of those diagnosed at an advanced stage was low compared to early stages. In addition, those who underwent surgery had higher survival than those who had no surgery for primary treatment.

벤처기업의 효율성과 재무요인이 기업의 생존에 미치는 영향 분석 (The Analysis of Financial Factors and efficiency that influence on the Venture Business' Survival)

  • 송성환;권성훈;홍순기;유경진;배영임
    • 경영과학
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    • 제27권1호
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    • pp.107-116
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    • 2010
  • There are several stage in corporate's life cycle such as foundation, growth, maturity or bankruptcy. A bankruptcy is very important for corporate in the life cycle. Especially, venture business' life cycle is short compare to other type of corporate. A lot of venture businesses have emerged and bankrupted soon in the market. Venture businesses' survival or bankruptcy have been influenced by not only external environment like the rate of exchange, oil price, and foreign exchange crisis but also internal environment such as efficiency, process, human resources, finance and CEO. In this paper, we attempt to examine financial factors and efficiency that influence on the venture businesses' survival and bankruptcy. The more venture businesses have high efficiency score, the more they have high probability of survival.

Association of Educational Levels with Survival in Indian Patients with Cancer of the Uterine Cervix

  • Krishnatreya, Manigreeva;Kataki, Amal Chandra;Sharma, Jagannath Dev;Nandy, Pintu;Gogoi, Gayatri
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권8호
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    • pp.3121-3123
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    • 2015
  • The main objective of this paper was to assess the influence of educational level on the survival of uterine cervix cancer patients in our population. A total of 224 patients were registered in our registry, of which 178 had information on stage and different educational levels. The overall median survival (MS) was 23 months, with values of 18.5, 20.7 and 41.3 months for the illiterate, literate and qualified groups, respectively. In the illiterate patients, stage I was seen in 2.6% and stage IV in 11.8%, while in other 2 groups stage I was seen in 10% to 17% of patients at the time of diagnosis. The survival probability at around 50 months was around 42%, 30% and 26% (approximately) for qualified, literates and illiterates respectively [Log Rank (Mantel-Cox) showed p=0.023]. Emphasis on imparting education to females can be a part of comprehensive cancer control programme for improving the overall survival in patients with carcinoma of the uterine cervix in our population.

신흥국 기업의 지배구조와 기업의 장기 생존 (Corporate Governance and Long-term Corporate Survival in an Emerging Economy)

  • 김장훈;안세연
    • 무역학회지
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    • 제46권3호
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    • pp.65-79
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    • 2021
  • This paper investigates how corporate governance characteristics are related to long-term corporate survival in an emerging economy. We used the data of 311 companies listed on the Korean Stock Exchange (KSE) in 1979 and examined the survival chances of those companies through the IMF crisis in 1998, upon governance characteristics that are expected to increase long-term strategic orientations. We utilized Cox regression model for the analysis. The results indicate that firms with particular governance characteristics that may be tied to CEO's long-term orientations show higher long-term survivability. Specifically, the probability of a firm's long-term survival is increased when founding family ownership is sustained, the company ownership is concentrated, and the CEO is the largest shareholder. This study has significance in that it is one of initial tries to examine the impact of corporate governance on long-term corporate survival with large scale statistical analysis. Also, the study findings provide some clues as to why the portion of family firms in emerging economies is continuously increased, thus providing meaningful insights to corporate governance literature.

Model-Based Survival Estimates of Female Breast Cancer Data

  • Khan, Hafiz Mohammad Rafiqullah;Saxena, Anshul;Gabbidon, Kemesha;Rana, Sagar;Ahmed, Nasar Uddin
    • 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.

Evaluation of Probability of Survival Using Trauma and Injury Severity Score Method in Severe Neurotrauma Patients

  • Moon, Jung-Ho;Seo, Bo-Ra;Jang, Jae-Won;Lee, Jung-Kil;Moon, Hyung-Sik
    • Journal of Korean Neurosurgical Society
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    • 제54권1호
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    • pp.42-46
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    • 2013
  • Objective : Despite several limitations, the Trauma Injury Severity Score (TRISS) is normally used to evaluate trauma systems. The aim of this study was to evaluate the preventable trauma death rate using the TRISS method in severe trauma patients with traumatic brain injury using our emergency department data. Methods : The use of the TRISS formula has been suggested to consider definitively preventable death (DP); the deaths occurred with a probability of survival (Ps) higher than 0.50 and possible preventable death (PP); the deaths occurred with a Ps between 0.50 and 0.25. Deaths in patients with a calculated Ps of less than 0.25 is considered as non-preventable death (NP). A retrospective case review of deaths attributed to mechanical trauma occurring between January 1, 2011 and December 31, 2011 was conducted. Results : A total of 565 consecutive severe trauma patients with ISS>15 or Revised Trauma Score<7 were admitted in our institute. We excluded a total of 24 patients from our analysis : 22 patients younger than 15 years, and 2 patients with burned injury. Of these, 221 patients with head injury were analyzed in the final study. One hundred eighty-two patients were in DP, 13 in PP and 24 in NP. The calculated predicted mortality rates were 11.13%, 59.04%, and 90.09%. The actual mortality rates were 12.64%, 61.547%, and 91.67%, respectively. Conclusion : Although it needs to make some improvements, the present study showed that TRISS performed well in predicting survival of traumatic brain injured patients. Also, TRISS is relatively exact and acceptable compared with actual data, as a simple and time-saving method.