• Journal of Applied Reliability
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• v.10 no.1
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• pp.73-91
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• 2010

All activities relate to railway traffic involve risk and that these arise from a combination of the nature of operating activities. Proper management system is required to provide the organizational capability to reveal, analyse and address these weaknesses over time and in reasonably practicable ways, which will determine the rate at which risks can be further reduced. This paper presents a systematic risk analysis approach to safety planning and decision making, informed by a range of risk assessment techniques. An railway organization's safety management system is also presented that shows the approaches taken to minimize the external risks, and identify the shared risks and explain how they will be controlled through collaboration with others.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.139-141
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• 2003

The outage cost has very important position for determination of the optimal level or optimal range of reliability in power system expansion planning. Establishing the worth of service reliability is a very difficult and subjective task. This paper addresses the role, need and assessment algorithm and methodology of the outage cost on power system expansion planning. Furthermore outage cost has been assessed using macro approach for our country 15years(1986-2001) in the case study.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.1
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• pp.42-48
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• 2008

A system of risk assessment is developed by using the reliability analysis which evaluate quantitatively both stability and performance of sloped-coastal structures according to several scenarios of sea-level rise. By using reliability functions on armor unit and run-up, the probabilities of failure can be straightforwardly calculated with respect to several design parameters such as nominal diameter of armor unit, slope of coastal structure, and freeboard height. By comparing the results before and after sea-level rise, it may be possible to exactly assess some ranges of decrease of stability and performance of sloped-coastal structure with respect to sea-level rise. Therefore, it can also be possible to make a decision which parameters should be repaired or strengthened in order to maintain the original stability and performance of sloped-coastal structures. Finally, The present results may be useful for designing some kinds of new sloped-coastal structures including the effect of sea-level rise.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.33-39
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• 2006

Home modification has come to be recognized as an important intervention strategy to manage health care conditions, maintain or improve functioning, ensure safety, and reduce the wheelchair user's dependency on others. However, the availability of skilled professionals with experience in home modifications for accessibility is limited. A system that enables accurate remote assessments would be an important tool to improve our ability to perform home assessments more easily and at decreased cost. A Remote Wheelchair Accessibility Assessment System (RWAAS) using Virtualized Reality(VR) technology was developed that enabled clinicians to assess the wheelchair accessibility of users' built environments from a remote location. Characteristics of the camera and 3D reconstruction program chosen for the system significantly affect its overall reliability. In this study, we performed two reliability analyses on the hardware and software components: 1) Verification that commercial software can construct sufficiently accurate 3D models by analyzing the accuracy of dimensional measurements in a virtualized environment; 2) comparison of dimensional measurements with four camera settings. Based on these two analyses, we were able to specify a consumer level digital camera and the Photomodeler Pro software for this system. And we then tested the feasibility of the selected software and hardware in an actual environment. Lastly, A field evaluation was performed to test whether this new system is comparable to the traditional method of accessibility assessment to evaluate its ability to assess the accessibility of a wheelchair user's typical built environment. The results of field trials showed high congruence between the assessments by two methods. Findings suggested that the RWAAS assessments have the potential to enable specialists to assess potential accessibility problems in built environments regardless of the location of the client, home, or specialist.

• English Language & Literature Teaching
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• v.15 no.4
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• pp.157-175
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• 2009

This paper offers a critical review of a newspaper argument regarding the problems of high school education assessment for university entrance examination system in the United Kingdom. The media account raises three sets of questioning to hold that the nation's long-standing A-levels have failed and is no longer viable as a high-stakes test. However, it is found that the writer's argumentations involving misleading conceptions can be deconstructed because of invalid reasoning and unreliable evidence. So, it is proposed that a reasonable solution to replace the discredited A-level exams should be to adopt an eclectic approach for assessing candidates' multiple capabilities; performance, potentiality and critical thinking skills. These criteria for component-oriented assessments are designed to measure their high school academic achievements and intellectual capacity for tertiary education; in the process of such measurement, critical-logical reasoning abilities for sound judgment and problem-solving tasks should be incorporated with the basic precondition that each university possesses its own discretion for the determination of adequate proportions to reflect each of the assessment outcomes. It is, therefore, expected that this critical review will inspire the readers to understand aspects of assessment as an educational field and to confirm how seriously they may be misguided by a distorted media argumentation without substantive background knowledge.

• International Journal of High-Rise Buildings
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• v.9 no.2
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• pp.175-185
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• 2020

Currently, few studies have been conducted to comprehend the seismic reliability of post-tensioned (PT) CLT shear wall structures, due to the complexity of this kind of structural system as well as due to lack of a reliable structural model. In this paper, a set of 4-, 8-, 12-, and 16-storey benchmark PT CLT shear wall structures (PT-CLTstrs) were designed using the direct displacement-based design method, and their calibrated structural models were developed. The seismic reliability of each PT-CLTstr was assessed based on the fragility analysis and based on the response surface method (RSM), respectively. The fragility-based reliability index and the RSM-based reliability index were then compared, for each PT-CLTstr and for each seismic hazard level. Results show that the RSM-based reliabilities are slightly less than the fragility-based reliabilities. Overall, both the RSM and the fragility-based reliability method can be used as efficient approaches for assessing the seismic reliabilities of the PT-CLTstrs. For these studied mid- and high-rise benchmark PT-CLTstrs, following their fragility-based reliabilities, the 8-storey PT-CLTstr is subjected to the least seismic vulnerability; while, following their RSM-based reliabilities, the 4-storey PT-CLTstr is subjected to the least seismic vulnerability

• Journal of Applied Reliability
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• v.16 no.3
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• pp.231-237
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• 2016

Purpose: It is not easy to suggest a quantitative data related to safety analysis. The objective of this paper is to propose a method of Safety Integrity Level (SIL) analysis and to suggest a SIL analysis result for single station controller in nuclear power plant based on IEC 61508. Methods: The Failure Modes and Effects Diagnostic Analysis (FMEDA) and average probability of failure on demand (PFD) are used for SIL assessment. Results: A SIL of single station controller is evaluated 4 by a reliability analysis results and PFD. Conclusion: A SIL analysis method and result for single station controller based on IEC 61508 are proposed in this paper. It can applicable for a manufacturer data in safety-related system.

• Computers and Concrete
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• v.6 no.4
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• pp.281-303
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• 2009

The lack of safety of bridge deck structures causes frequent repair and strengthening of such structures. The repair induces great loss of economy, not only due to direct cost by repair, but also due to stopping the public use of such structures during repair. The major reason for this frequent repair is mainly due to the lack of realistic and accurate assessment system for the bridge decks. The purpose of the present research was to develop a realistic expert system, called Bridge Slab-Expert which can evaluate reasonably the condition as well as the service life of concrete bridge decks, based on the deterioration models that are derived from both the structural and environmental effects. The diagnosis assessment of deck slabs due to structural and environmental effects are developed based on the cracking in concrete, surface distress and structural distress. Fuzzy logic is utilized to handle uncertainties and imprecision involved. Finally, Bridge Slab-Expert is developed for prediction of safety and remaining service life based on the chloride ions penetration and fick's second law. Proposed expert system is based on user-friendly GUI environment. The developed expert system will allow the correct diagnosis of concrete decks, realistic prediction of service life, the determination of confidence level, the description of condition and the proposed action for repair.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.6
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• pp.595-602
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• 2018

Objective: The Korean Triage and Acuity Scale (KTAS), which was implemented in 2016, needs to be assessed for its validity and reliability. Here we evaluate the relevance of emergency level assessment by analyzing the validity of KTAS as a Korean standardized triage system. Methods: We retrospectively analyzed the medical records of adults who presented to a local emergency room (ER) during an 18-month period. We compared medical resources used, life-saving interventions performed, length of stay (LOS) in ER, admission rate, and mortality at each KTAS level. Results: Among a total of 40,339 patients, most patients were at KTAS 4 (n=19,532, 48.4%) and the longest median LOS in ER was 450 minutes at KTAS 2. As the KTAS level increased, the percentage of medical resources used and lifesaving interventions performed increased significantly. The odds of total admission and intensive care unit admission were significantly higher at KTAS 1 through 4 compared to those at KTAS 5. The odds related to admission and mortality were also significantly higher at KTAS 3 than at KTAS 4. Conclusion: We concluded that the KTAS, as a Korean standardized triage system of emergency level assessment, is relevant. Further, KTAS 1-3 and KTAS 4-5 are appropriate criteria to distinguish emergency and non-emergency patients.

• Journal of the Korea Safety Management & Science
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• v.4 no.1
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• pp.37-47
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• 2002

Risk analysis is a formal deductive procedure for determining combinations of component failures and human errors that could result in the occurrence of specified undesired events at the system level. This method can be used to analyze the vast majority of industrial system reliability problems. This study deals with the application of knowledge-engineering and a methodology for the assessment ＆ measurement of reliability, availability, maintainability, and safety of industrial systems using FTA(fault tree analysis), A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach (insufficient Information concerning the relative frequencies of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations, The purpose of this study is to describe the knowledge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.