• Journal of the Korean Statistical Society
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• v.35 no.3
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• pp.251-260
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• 2006

The proportional hazards model (PHM) can be associated with a non- homogeneous Markov chain (NHMC) in the sense that sample alignments in the PHM correspond to trajectories of the NHMC. As a result the partial likelihood widely used for the PHM is a probabilistic function of the trajectories of the NHMC. In this paper, we show that, as the total number of subjects involved increases, the trajectories of the NHMC, i.e. sample alignments in the PHM, converges to the solution of an ordinary differential equation which, subsequently, characterizes the almost sure limit of the partial likelihood.

• Fire Protection Technology
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• s.14
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• pp.5-12
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• 1993

This report is explained about test results of carbon dioxide extinguiching system components and pack-age type system (Kits) for automatic fire extinguishing system. A carbon dioxide system may be used to protect one or more hazards or hazards by menas of directional valves. Package system shall be installed to protect hazards within the limitations. The testing program was progressed by three items, external oppearance test, performance test and Total Flooding Fire Extinguishing System test. The object of this report is present the problem which apperar from the analysis of test results.

• Journal of the Korean Data and Information Science Society
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• v.15 no.2
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• pp.347-353
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• 2004

We propose a simple nonparametric estimator of relative risk in the two sample case of the proportional hazards model for complete data. The asymptotic distribution of this estimator is derived using a functional equation. We obtain the asymptotic normality of the proposed estimator and compare with Begun's estimator by confidence interval through simulations.

• International Journal of Safety
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• v.4 no.2
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• pp.43-46
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• 2005

The construction workers might be at the risk of many occupational injuries and illnesses. To protect workers from various hazards, industrial health and hygiene systems were specified for the construction workers by law. It is important to know the actual health and safety(H&S) conditions by tasks and the characteristics of injuries and illnesses of construction workers. This study was designed to investigate the actual conditions of construction workers exposed to various harmful substances and work elements including evaluation of health status of each worker and general H&S system. Questionnaire was sent to 600 construction workers nationwide and totally 367 people responded to it having 61.67% of response rate. The common construction hazards were dust(29.6%), noise(19.3%), repetitive motions(12.0%), handling excessive heavy materials(11.2%) in order. The repetitive motions and handling heavy materials related to muscle disorders accounted for 23.2%. The accident and injury types were in order of overexertion, falling, overturning, dropping or flying, electric shock, collision, etc.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.2
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• pp.1-9
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• 1998

To achieve high performance in VLIW processors, they must exploit the parallelism on application programs. Data dependency makes it difficult to find the instruction-level parallelism. Among the three kinds of data dependency, true dependency causes RAW(Read After Wirte) hazards that occur most frequently in VILW processors. Forwarding is a widely used technique to reduce the performance degradation caused by RAW hazards. However, forwarding requires too much area of the chip when it is applied to VLIW processors. In this paper, static forwarding is proposed to reduce the hardware cost of forwarding circuits. It needs an extended compiler to detect RAW hazards and control the proposed forwarding scheme via instruction. And it uses the modified register file to shrink the area of forwarding path. VLIW Processor Model is also designed to verify static forwarding. This paper describes the operation of static forwarding and the comparison with the conventional forwarding.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.192-194
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• 2009

This study presents on the analysis fire hazards of communication cable. In order to analyze fire hazards fire retardant tests and con-calorimeter test is conducted. The fire retardant tests are IEC 60332-1 and UL 94 test. The results show that IEC 60332-1 test and It 9t test are not effective to estimate fire hazard. And various parameter is obtained by con-calorimeter test. It is necessary to analysis effectively fire hazards of cable for new fire retardant test.

• International Journal of Reliability and Applications
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• v.10 no.2
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• pp.101-107
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• 2009

In the accelerated tests, the importance of correct failure analysis must be strongly emphasized. Understanding the failure mechanisms is requisite for designing and conducting successful accelerated life test. Under this presumption, a rational method must be identified to relate the results of accelerated tests quantitatively to the reliability or failure rates in use conditions, using a scientific acceleration transform. Most widely used models for relating the results of accelerated tests quantitatively to the reliability or failure rates in use conditions are an accelerated failure time model and a proportional hazards model. The purpose of this research is to compare the usability of the accelerated failure time model and proportional hazards model in the accelerated life tests.

• 한국문화재보존과학회:학술대회논문집
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• 2006.04a
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• pp.146-150
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• 2006

• Journal of the Korea Safety Management & Science
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• v.19 no.4
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• pp.133-140
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• 2017

The Ministry of Science, ICT and Future Planning made law for Pre-Hazard Risk Analysis in December 31, 2014 to protect researchers from continuing accidents in laboratory. Conducted before an experiment, Pre-Hazard Risk Analysis finds hazards of the experiment and rules to manage the hazards.So the Pre-Hazard Risk Analysis can support laboratory safety system by prevent accidents in laboratory. Pre-Hazards Risk Analysis is newly created system so that executors need Guidelines to perform this analysis properly. This study is to develop guide tool for Pre-Hazard Risk Analysis by analyzing other risk assessment systems; PSM, Off-site Consequence Assessment, laboratory safety system. Also, this study suggested how to establish database for Pre-Hazard Risk Assessment by analyse KRAS.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.255-258
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• 2015

Scaffolds are frequently used in construction projects. Despite the impact on the entire safety, scaffolds are rarely analyzed as part of the safety planning. While recent advances in BIM (Building Information Modeling) provides opportunity to address potential safety issues in the early planning stages, it is still labor-intensive and challenging to incorporate scaffolds into current manual jobsite safety analysis which is time-consuming and error-prone. Consequently, potential safety hazards related to scaffolds are identified and presented during the construction phase. The objective of this research is to integrate scaffolds into automated safety analysis using BIM. A safety checking system was created to simulate the movements of scaffolds along the paths of crews using the scaffolds. Algorithms in the system automatically identify safety hazards related to activities working on scaffolds. Then, the system was implemented in a commercially available BIM software program for case studies. The results show that the algorithms successfully identified safety hazards that were not noticed by project managers of the projects. The results were visualized in BIM to facilitate early safety communications.