• 한국안전학회지
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• 제38권3호
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• pp.85-92
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• 2023

A safety helmet is considered the last gear to protect workers from harmful and dangerous events occurring on industrial sites. Recently, interest in the importance of personal protective equipment design reflecting individual characteristics has been emphasized to improve usability and convenience. However, it has been found that if it is inconvenient to wear or has poor work efficiency, it will not be used well or will be used incorrectly. In this study, an investigation was performed with 35 questions, direct observation, and intensive interviews of construction workers to determine the inconvenience and problems of wearing safety helmets. Moreover, managers of 9 construction sites in 6 cities were asked about the performance and design of safety helmets. As a positive answer, it was found that the brim (awning) of the safety helmet was shortened to give the safety glasses a light-shielding function. In addition, an upward adjustment all-in-one type safety helmet was requested. On the other hand, it was revealed that negative answers felt uncomfortable due to the brim (awning) on the front of the helmet. Based on the survey results, a new helmet model suitable for construction site activities was presented, and wearability improvement determinants were discovered through performance and design improvement.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권2호
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• pp.141-150
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• 2012

Ship damage caused by maritime casualties leads to marine pollution and loss of life and property. To prevent serious damage from maritime casualties, several types of safety regulations are applied in ship design. Damage stability regulation is one of the most important safety issues. Designs of ships for long international voyages must comply with these regulations. Current regulations, however, do not consider the characteristics of the operating route of each ship and reflect only ship size and type of cargo. In this paper, a damage safety assessment was undertaken for a ship carrying radioactive waste in actual wave conditions. Damage cases for safety assessment were constructed on the basis of safety regulations and related research results. Hull form, internal arrangement, loading condition and damage condition were modeled for damage safety simulation. The safety simulation was performed and analyzed for 10 damage cases with various wave heights, frequency and angle of attack on an operating route. Based on evaluation results, a design alternative was generated, and it was also simulated. These results confirmed that damage safety analysis is highly important in the design stage in consideration of the operating route characteristics by simulation. Thus a ship designer can improve safety from damage in this manner.

• Nuclear Engineering and Technology
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• 제53권2호
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• pp.498-508
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• 2021

Micro reactors are increasingly being considered for utilization as distributed power sources. Hence, the probabilistic safety assessment (PSA) of a direct supercritical-CO₂-cooled fast reactor, called micro modular reactor (MMR), was performed in this study; this reactor was developed using innovative design concepts. It adopted a modular design and passive safety systems to minimize site constraints. As the MMR is in its conceptual design phase, design weaknesses and valuable safety insights could be identified during PSA. Level 1 internal event PSA was carried out involving literature survey, system characterization, identification of initiating events, transient analyses, development of event trees and fault trees, and quantification. The initiating events and scenarios significantly contributing to core damage frequency (CDF) were determined to identify design weaknesses in MMR. The most significant initiating event category contributing to CDF was the transients with the power conversion system initially available category, owing to its relatively high occurrence frequency. Further, an importance analysis revealed that the safety of MMR can be significantly improved by improving the reliability of reactor trip and passive decay heat removal system operation. The findings presented in this paper are expected to contribute toward future applications of PSA for assessing unconventional nuclear reactors in their conceptual design phases.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.529-535
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• 2008

Recently a rolling stock has been requiring more convenience facilities for passenger as well as satisfied the basic functions. The convenience facilities design take into consideration safety factor, convenience and easy accessible for disable passenger. In a point of view, convenience facilities should be considered and designed as well as related safety. This paper describes points to be considered on design with related to convenience facilities and safety factor of Diesel Multiple Unit for Intercity through the IRISH DMU.

• 한국안전학회지
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• 제34권3호
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• pp.102-110
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• 2019

This paper describes the work and results of the preliminary Probabilistic Safety Assessment (PSA) for a research reactor in the design phase. This preliminary PSA was undertaken to assess the level of safety for the design of a research reactor and to evaluate whether it is probabilistically safe to operate and reliable to use. The scope of the PSA described here is a Level 1 PSA which addresses the risks associated with core damage. After reviewing the documents and its conceptual design, eight typical initiating events are selected regarding internal events during the normal operation of the reactor. Simple fault tree models for the PSA are developed instead of the detailed model at this conceptual design stage. A total of 32 core damage accident sequences for an internal event analysis were identified and quantified using the AIMS-PSA. LOCA-I has a dominant contribution to the total CDF by a single initiating event. The CDF from the internal events of a research reactor is estimated to be 7.38E-07/year. The CDF for the representative initiating events is less than 1.0E-6/year even though conservative assumptions are used in reliability data. The conceptual design of the research reactor is designed to be sufficiently safe from the viewpoint of safety.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제27권3호
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• pp.27-37
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• 2021

Purpose: The purpose of this study is to compare the changes in hospital accreditation evaluations, the changes in hospital building design guidelines, and the development of design indicators for reducing medical accidents in the state-of-the-art healthcare providers. Methods: The changes and tools were carefully investigated and compared that had been taken place and used in the building certification standards, design guidelines, and patient safety design standards to reduce accidents in the United States and the United Kingdom. Results: First, medical accidents are recognized as multiple defense layers rather than personal ones, and a public reporting and learning system is created, reporting the accidents in question publicly and suggesting ways to improve them based on the data at a time. Second, for the accreditation institute that secures the service quality of medical institutions, detailed standards for patient safety are continuously updated with focus on clinical trials. The United States is in charge of the private sector, but on the other hand the United Kingdom is in charge of the public sector. Third, the design guidelines are provided as web-based tools that complement various guidelines for patient safety, and are improved and developed as well. Fourth, detailed approaches are continuously developed and provided to secure patient safety and reduce medical accidents through appropriate research, evidence-based design and strict evaluations. Implications: When medical institutions make efforts to strength patient safety methods through valid design standards, accidents are expected to decrease, whereby hospital finances are also to be improved. A higher level of medical quality service will sure be secured through comprehensive certification evaluation.

• Communications for Statistical Applications and Methods
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• 제26권2호
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• pp.163-173
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• 2019

Simon's two-stage designs are frequently used in phase II single-arm trials for efficacy studies. A concern of safety studies is too many patients who experience an adverse event. We show that Simon's two-stage designs for efficacy studies can be similarly used to design a two-stage safety study by modifying some of the design parameters. Given the type I and II error rates and the proportion of adverse events experienced in the first stage cohort, we prescribe a procedure whether to terminate the trial or proceed with a stage 2 trial by recruiting additional patients. We study the relationship between a two-stage design with a safety endpoint and an efficacy endpoint as well as use simulation studies to ascertain their properties. We provide a real-life application and a free R package gen2stage to facilitate direct use of two-stage designs in a safety study.

• 한국안전학회지
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• 제22권1호
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• pp.7-12
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• 2007

There are two kinds of design process for sprinkler system. one is pipe schedule system and the other is hydraulically designed system. We have inefficient results when we design by hydraulically designed system because the design process for sprinkler system is restricted by domestic fire code. Therefore, it is essential to do an introduction of hydraulically designed system which is based on engineering for enhancing reliability and efficiency of sprinkler system. This study presents points at issue by comparing and studying design standards of sprinkler system from Korea, Japan and NFPA, and presents improvement plans of national fire safety code of sprinkler system by processing, comparing and analyzing designs according to piping schedule and hydraulically designed system about domestic objects. Installation standards of sprinkler system have to be applied not by object buildings but by hazard classification. It is hard to design an efficient sprinkler system for fire control when water supply requirement of sprinkler systems allocated according to a size of a building because the same purpose but other buildings may request more water requirement or less. We should sublate the pipe schedule system from national fire safety code and need to introduce the hydraulically designed system. The pipe schedule system presents easy access because it is based on the forecasted engineering calculations but it is applied to only small buildings like NFPA due to its low reliability.

• Journal of Ship and Ocean Technology
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• 제12권4호
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• pp.32-39
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• 2008

According to the increase of the requirement for the safety and environmental protection at sea, safety is a core design factor of maritime systems. Safety is defined as a perceived quality that determines to what extent the management, engineering and operation of a system is free of danger to life, property and the environment. There are many possible approaches in dealing with the safety of ships. The risk-based approach is one of the most systematic and reasonable way currently in design, operation and regulatory works for ship safety. This paper proposes a concept of total risk management for ship safety, and introduces a prototype system implemented based on this concept as a framework of design and operation of ships.

• Steel and Composite Structures
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• 제5권1호
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• pp.71-86
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• 2005

Based on the test data of Nippon Steel Corporation, the formulas for calculating mechanical properties of fire-resistant (FR) steel at elevated temperatures have been established. A practical approach for fire safety design of FR steel members, including axially compressed members, flexural members and eccentrically compressed members, is developed in this paper. Compared with the full-scale specimen experiments and FEM numerical analysis, this practical approach for fire safety design of FR steel members is demonstrated to be effective and precise.