• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.4
• /
• pp.1533-1537
• /
• 2012

In general, breast cancer is the most common malignancy among women in developed as well as some developing countries, often being the second leading cause of cancer mortality after lung cancer. Using a parametric log-logistic model to consider the effects of prognostic factors, the present study focused on the 5-year survival of women with the diagnosis of breast cancer in Southern Iran. A total of 1,148 women who were diagnosed with primary invasive breast cancer from January 2001 to January 2005 were included and divided into three prognosis groups: poor, medium, and good. The survival times as well as the hazard rates of the three different groups were compared. The log-logistic model was employed as the best parametric model which could explain survival times. The hazard rates of the poor and the medium prognosis groups were respectively 13 and 3 times greater than in the good prognosis group. Also, the difference between the overall survival rates of the poor and the medium prognosis groups was highly significant in comparison to the good prognosis group. Use of the parametric log-logistic model - also a proportional odds model - allowed assessment of the natural process of the disease based on hazard and identification of trends.

• Journal of the Korean Data and Information Science Society
• /
• v.15 no.3
• /
• pp.605-616
• /
• 2004

In this paper we consider the proportional hazard models for survival analysis in the microarray data. For a given vector of response values and gene expressions (covariates), we address the issue of how to reduce the dimension by selecting the significant genes. In our approach, rather than fixing the number of selected genes, we will assign a prior distribution to this number. To implement our methodology, we use a Markov Chain Monte Carlo (MCMC) method.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2004.10a
• /
• pp.615-618
• /
• 2004

The previous quantitative bankruptcy prediction models cannot include time dimension. To overcome this limit, various dynamic models using survival analysis are developed recently. This paper emphasizes that the proportionality assumption must be adapted with caution when the Cox's proportional hazard model is used to explain bankruptcy. It is shown that a non-proportional hazard model including a change point model is a proper alternative, when the proportionality assumption is violated by the change of macroeconomic environment, such as the financial crisis in 1997.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2006.04a
• /
• pp.339-344
• /
• 2006

Slope failures are happen to natural disastrous when they occur in mountainous areas adjoining highways in Korea. The accidents associated with slope failures have increased due to rapid urbanization of mountainous areas. Therefore, Regular maintenance is essential for all slope and conducted to maintain road safety as well as road function. In this study, we take priority of making a database of risk factor of the failure of a slope before assesment and analysis. The purpose of this paper is to recommend a standard of Slope Management Information Sheet(SMIS) like as Hazard Map. The next research, we suggest to pre-estimated model of a road slope using Logistic Regression Model.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.8 no.2
• /
• pp.1-10
• /
• 2012

In this study, software products developed in the course of testing, software managers in the process of testing software test and test tools for effective learning effects perspective has been studied using the NHPP software. The finite failure nonhomogeneous Poisson process models presented and the life distribution applied exponential and log shaped type hazard function. Software error detection techniques known in advance, but influencing factors for considering the errors found automatically and learning factors, by prior experience, to find precisely the error factor setting up the testing manager are presented comparing the problem. As a result, the learning factor is greater than autonomous errors-detected factor that is generally efficient model could be confirmed. This paper, a failure data analysis of applying using time between failures and parameter estimation using maximum likelihood estimation method, after the efficiency of the data through trend analysis model selection were efficient using the mean square error and coefficient of determination.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.22 no.53
• /
• pp.79-88
• /
• 1999

This paper presents an integral model for product safety and product liability resulting from a defective product. The essence of the paper is the process of supply of manufacturing products which satisfy the product liability and the product safety in terms of consumers expectation levels. The main criteria of the product safety is the hazard level which involves in the severity and frequency. The proposed model shows the process to supply the manufactured products under the conditions that they are suitable in comparison of hazard level and safety level established by each company. If the product do not meet the safety level, this paper proposes that four different types of PL and PS countermeasures for the risk types are forward, respectively.

• The Korean Journal of Applied Statistics
• /
• v.11 no.1
• /
• pp.163-175
• /
• 1998

The change of hazard rates at some unknown time point has been the interest of many statisticians. But it was restricted to the constant hazard rates which correspond to the exponential distribution. In this paper we generalize the change-point model in which any specific functional forms of hazard rates are net assumed. The assumed model includes various types of changes before and after the unknown time point. The Nelson estimator of cumulative hazard function is introduced. We estimate the change-point maximizing slope changes of Nelson estimator. Consistency and asymptotic distribution of bootstrap estimator are obtained using the martingale theory. Through a Monte Carlo study we check the performance of the proposed method. We also explain the proposed method using the Stanford Heart Transplant Data set.

• 한국방재학회:학술대회논문집
• /
• 2009.02b
• /
• pp.36-42
• /
• 2009

A series of heavy rainfall, typhoon and earthquake disasters caused a proportionately large number of deaths among the elderly in the year 2004 in Japan. In response to these tragedies, the national government set up committees to reduce damage within the disaster vulnerable population for the next three years. The discussions in the committee led to a new conceptualization that disaster vulnerability was caused by a lack of interaction between a person's special needs and the environment's capacity and resources to meet them. This person-in-environment model of hazard vulnerability was applied to those who resided in the Nankai-Tonankai tsunami hazard-prone area. 123 home care service users were interviewed in terms of their self-evacuation ability, degree of social isolation, and building weakness as well as tsunami exposure risks. Results were quantified and scores of person-in-environmentmodel hazard vulnerability were obtained. These scores were then used to visualize socially created vulnerability by means of weighted kernel density mapping of both persons with special needs (PSN's) and persons with special needs at times of disaster (PSND's).

• Journal of the Korean Association of Geographic Information Studies
• /
• v.8 no.4
• /
• pp.81-90
• /
• 2005

Based on the landslide hazard scoring system of Korea Forest Research Institute, a GIS model for predicting landslide hazards was developed. The risk of landslide hazards was analyzed as the function of 7 environmental site factors for the terrain, vegetation, and geological characteristics of the corresponding forest stand sites. Among the environmental factors, slope distance, relative height and shapes of slopes were interpreted using the forestland slope interpretation module developed by Chung et al. (2002). The program consists of three modules for managing spatial data, analyzing landslide hazard and report-writing, A performance test of the model showed that 72% of the total landslides in Youngin-Ansung landslides area took place in the highly vulnerable zones of grade 1 or 2 of the landslide hazard scoring map.

• Journal of the Korean Society of Safety
• /
• v.26 no.2
• /
• pp.70-76
• /
• 2011

Industrial accident frequency in small- and medium-sized ship-building plants is much higher than that of large-sized ones so that safety management activities should be different. In that sense, voluntary hazard assessment would be helpful for small- and medium-sized plants. However, conventional hazard assessment items and methods had some problems that discouraged voluntary participation of plants concerned. This study aimed to develop a new model for small- and medium-sized ship-building plants that can promote and encourage voluntary hazard assessment activities. For that purpose, ship-building process was assumed as a sequence of phases, and accident characteristics were compared with them. From that result, relative weights of accident factors including ship-building phases, accident types, occupational category, accident-induced objects, and hazardous items were determined with accident frequency data and with the help of expert groups. Therefore, for web-based integrative computer programming, a plain but accident data-dependent model was developed, with an additive function for related agencies that want to collect assessment results. It is expected that this model would help small- and medium-sized ship-building plants that wanted not only simple checklists but also effective assessment and management guidelines.