• Nuclear Engineering and Technology
• /
• v.55 no.2
• /
• pp.623-639
• /
• 2023

The specific configuration of the safety systems in VVER-1000/V320 reactors allows a comprehensive study of the Loss of Coolant Accident (LOCA). In the present paper, a verification of the success criteria of the event trees headers for the medium and large break LOCA sequences is conducted. A detailed TRACEV5P5 thermal-hydraulic model of the reactor has been developed, including all safety systems. When analyzing the results of all sequences, some conservatism is observed in certain specific configurations as the success criterion of some headers is not consistent with the classic PSA level 1. Therefore, new proposals for the LOCA event trees are performed based on a reconfiguration of LOCA break ranges and the use of the expanded event trees approach.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2020.11a
• /
• pp.4-5
• /
• 2020

Pipe support is a representative structure that supports slab formwork, and it is a representative temporary equipment that has been systematically managed since the 1990s when the domestic temporary equipment performance test system was introduced. Nevertheless, it is also a reality that many of the products in circulation are used products that are reused and do not meet the performance of the initial manufacturing stage. However, if only new products are insisted, it could lead to delays in the process due to an increase in construction costs and difficulties in timely delivery. On the contrary, it is not acceptable for the safety of the construction site to use products of low quality without verification procedures or standards. Therefore, this study attempts to grasp the management system such as safety certification for temporary equipment and the actual condition of quality control to maintain performance, and propose improvement plans.

• Journal of the Korean Society of Safety
• /
• v.33 no.2
• /
• pp.76-85
• /
• 2018

The interest in the Building Information Modeling (BIM) technology has risen remarkably due to the effects on construction work period reduction, cost reduction, work safety improvement, and other factors. In civil engineering field, BIM applications mainly focus on data modeling and virtual construction. In this study, we present the BIM-based virtual construction and analyze the effects of BIM for the railway facilities so that the conventional approach to the equipment operation plan can be improved in order to prevent safety accidents which can result from unclear information during the operation plan. The BIM-based virtual construction technology is applied to establish the construction plan for the site with constraints, the installation of steel girder needs to be completed, avoiding interference with the existing high-speed railway operation within a given limited time. A virtual construction model consisting of topography, structures, equipments, and avatar was built and more detailed model, including safety guard rails, was then created. Specifications of the construction equipment were input as a database, and the virtual construction model was manipulated in the equipment operation planning. Through the BIM-based virtual construction, including the verification of alternative construction method, 311 million won was saved and the construction period was shortened by 87 days compared to the original plan. In addition, it was shown that the interest and participation of the construction workers can be increased by providing the 3D virtual scene for real construction work and various safety hazards occurring during equipment operation can be effectively removed in advance by the interactive worker education.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.9
• /
• pp.4341-4347
• /
• 2016

Background: Patient safety is one of the key components of nursing care for cancer cases. Valid and reliable context-based instruments are necessary for accurate evaluation of patient safety in oncology units. The aim of the present study was to develop and evaluate the psychometric properties of the Patient Safety Violation Scale in medical oncology units in Iran. Materials and Methods: In this methodological study, a pool of 58 items was generated through reviewing the existing literature. The validity of the 58-item scale was assessed through calculating impact score, content validity ratio, and content validity index for its items as well as conducting exploratory factor analysis. The reliability of the scale was evaluated by assessing its internal consistency and testretest stability. Study sample consisted of 300 oncology nurses who were recruited from thirteen teaching hospitals affiliated to Tehran University of Medical Sciences, Tehran, Iran. Results: Sixteen items were excluded from the scale due to having low impact scores, content validity ratios, or content validity indices. In exploratory factor analysis, the remaining 42 items were loaded on five factors including patient fall, verification of patientidentity, harm during care delivery, delay in care delivery, and medication errors. These five factors explained 62% of the total variance. The Cronbach's alpha of the scale and the test-retest interclass correlation coefficient were equal to 0.933 and 0.92, respectively. Conclusions: The 42-item Patient Safety Violation Scale is a simple and short scale which has acceptable validity and reliability. Consequently, it can be used for assessing patient safety in clinical settings such as medical oncology units and for research projects.

• Journal of the Korean Society of Safety
• /
• v.37 no.2
• /
• pp.10-17
• /
• 2022

Currently, in Korea, lower and upper tier qualifying quantities of the 97 substances requiring preparation for accidents have been designated. The information on the submission of chemical accident prevention management plan varies depending on whether the handling volume is above or below the lower or upper qualifying quantity. Because the criteria of the lower and upper qualifying quantities of substance requiring preparation for accidents are not stipulated in the Chemical Substances Control Act, this study attempted to establish a criterion through significance verification. In addition, the study investigated whether these qualifying quantities are related to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), toxic concentration endpoint, and National Fire Protection Association (NFPA). Finally, by comparing the risk categorization of the GHS, endpoint, and NFPA, it was evaluated whether the circulation-volume-based risk categorization of the substance requiring preparation for accidents that are in the top 13 is appropriate. The qualifying quantities of benzene, toluene, and sulfuric acid needed to be adjusted upward, while those of methyl alcohol and ammonia were adjusted downward from the current qualifying quantities. It is required to establish a quantified criterion that fully reflects the domestic situations in Korea and various indicators such as toxicity, physicochemical properties, and circulation volume for the qualified criterion of hazardous chemical substances. The study is expected to be helpful in establishing an efficient system by systematizing the criterion for qualifying quantity.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.4_2
• /
• pp.943-951
• /
• 2024

This paper considers the simulation-based installation and operation safety analysis of installation and operation machinery of USBL as underwater equipment in operation environments. The simulation model of this mechanical system was developed using flexible multibody dynamics simulation technology. Operation and environmental conditions were applied using dynamic forces model considering ocean environments. The developed simulation model was used to evaluate operation safety through eigenvalue analysis, dynamic forces analysis, and structural analysis. As the analysis results, the operation safety was very low in extreme operation condition due to increase of dynamic loads by VIV effect. It was not a problem because safety factor had more than 2.0 in this case. However, the operation safety should be further strengthened because the USBL and LARS was installed and utilized in unmanned vessel with automatic controls. In order to improve safety by avoiding VIV frequency, we redesigned the USBL pole.

• International conference on construction engineering and project management
• /
• 2024.07a
• /
• pp.1057-1064
• /
• 2024

The construction industry has witnessed a concerning rise in ladder-related accidents, necessitating the implementation of stricter safety measures. Recent statistics highlight a substantial number of accidents occurring while using ladders, emphasizing the mandatory need for preventative measures. While prior research has explored computer vision-based automatic monitoring for specific aspects such as ladder stability with and without outriggers, worker height, and helmet usage, this study extends existing frameworks by introducing a rule set for co-workers. The research methodology involves training a YOLOv5 model on a comprehensive dataset to detect both the worker on the ladder and the presence of co-workers in real time. The aim is to enable smooth integration of the detector into a mobile application, serving as a portable real-time monitoring tool for safety managers. This mobile application functions as a general safety tool, considering not only conventional risk factors but also ensuring the presence of a co-worker when a worker reaches a specific height. The application offers users an intuitive interface, utilizing the device's camera to identify and verify the presence of coworkers during ladder activities. By combining computer vision technology with mobile applications, this study presents an innovative approach to ladder safety that prioritizes real-time, on-site co-worker verification, thereby significantly reducing the risk of accidents in construction environments. With an overall mean average precision (mAP) of 97.5 percent, the trained model demonstrates its effectiveness in detecting unsafe worker behavior within a construction environment.

• Journal of Digital Convergence
• /
• v.12 no.9
• /
• pp.219-223
• /
• 2014

In line with the advanced wireless communication technology, M2M (Machine-to-Machine) communication has drawn attention in industry. M2M communication features are installed and operated in the fields where human accessibility is highly limited such as disaster, safety, construction, health and welfare, climate, environment, logistics, culture, defense, medical care, agriculture and stockbreeding. In M2M communication, machine replaces people for automatic communication and countermeasures as part of unmanned information management and machine operation. Wireless M2M inter-device communication is likely to be exposed to intruders' attacks, causing security issues, which warrants proper security measures including cross-authentication of whether devices are legitimate. Therefore, research on multiple security protocols has been conducted. The present study applied SessionKey, HashFunction and Nonce to address security issues in M2M communication and proposed a safe protocol with reinforced security properties. Notably, unlike most previous studies arguing for the security of certain protocols based on mathematical theorem proving, the present study used the formal verification with Casper/FDR to prove the safety of the proposed protocol. In short, the proposed protocol was found to be safe and secure.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.5
• /
• pp.432-439
• /
• 2015

MEMS solid thruster module is composed of solid thruster and its control board. It was developed for the purpose of an academic research. Therefore, thermo-mechanical design and verification for space usage were not considered in the design phase. To mount it on a cube satellite without any design modification, technical efforts at the system level structure design is required. In this study, we proposed a structural design concept to mount the MEMS thruster module by using brackets for guaranteeing structure safety under launch loads and easier mating and de-mating of MEMS thruster module during test phase. The effectiveness of the design has been verified through structural analysis and vibration test. In addition, electrical connection method using spring pins between MEMS thruster and control board is effective for guaranteeing the structural safety under launch vibration loads.

• Journal of the Korea Safety Management & Science
• /
• v.19 no.2
• /
• pp.117-133
• /
• 2017

The purpose of this study is to consider the relation between the deciding factors of local identity and local image improvement. To achieve this purpose, the deciding factors of local identity have been set as the following four: historical identity, cultural identity, (nature) scenery identity, and industrial identity. The writer has established a model to represent the relation between these factors and the local image improvement, namely 'Visitor Satisfaction' and 'Revisit Intentions', and framed a hypothesis for empirical verification. The study results are as follows: First, the deciding factors of local identity which this study addressed are empirically proven to have a significant effect on the visitor satisfaction and the intention to revisit in which is it likely that the greater the impact of the deciding factors, the higher the visitor satisfaction and revisit intentions would be. Second, the deciding factors of local identity, it appears that the 'historical identity' factor had the largest impact on the visitor satisfaction, and the 'cultural identity' factor had the largest impact on the revisit intentions. Therefore, of the four deciding factors, the 'historical identity' should be considered the highest priority to increase the visitor satisfaction, and the 'cultural identity' should be considered the highest priority to increase the revisit intentions. Third, based on the verification of the relation between the visitor satisfaction and revisit intentions, it can be presumed that the greater the visitor satisfaction, the higher the revisit intentions would be.