• Journal of Korean Society for Quality Management
• /
• v.41 no.4
• /
• pp.725-735
• /
• 2013

Purpose: The purpose of this study is to propose an Integrated Safety Evaluation Process (ISEP) that can enhances the safety aspect of the safety-critical system. This process utilizes the advantages of the iterative Systems Engineering process combined with the safety assessment process that is commonly and well defined in many standards and/or guidelines for railway, aerospace, and other safety-critical systems. Methods: The proposed process model is based on the predefined system lifecycle, in each phase of which the appropriate safety assessment activities and the safety data are identified. The interfaces between Systems Engineering process and the safety assessment process are identified before the two processes are integrated. For the integration, the elements at lower level of Systems Engineering process are combined with the relevant elements of safety assessment process. This combined process model is represented as Enhanced Functional Flow Block Diagram (EFFBD) by using CORE(R) that is commercial modelling tool. Results: The proposed model is applied to the lifecycle and management process of the United States aircraft system. The US aircraft systems engineering process are composed of twelve key elements, among which the requirements management, functional analysis, and Synthesis processes are considered for examplenary application of the proposed process. To synchronize the Systems Engineering process and the safety assessment process, the Systems Engineering milestones are utilized, where the US aircraft system has thirteen milestones. Taking into account of the nine steps in the maturity level, the integrated process models are proposed in some phases of lifecycle. The flows of processes are simulated using CORE(R), confirming the flows are timelined without any conflict between the Systems Engineering process and the safety assessment process. Conclusion: ISEP allows the timeline analysis for identifying activity and data flows. Also, the use of CORE(R) is shown to be effective in the management and change of process data, which helps for the ISEP to apply for the development of safety critical system. In this study, only the first few phases of lifecyle are considered, however, the implementation through operation phases can be revised by combining the elements of safety activities regarding those phases.

• Proceedings of the Korea Contents Association Conference
• /
• 2014.06a
• /
• pp.167-168
• /
• 2014

• Journal of Venture Innovation
• /
• v.7 no.2
• /
• pp.143-152
• /
• 2024

Recently, as a lot of software with AI functions has been developed, the number of software products with various prediction functions is increasing, and as a result, the importance of software quality has increased. In particular, as consideration for functional safety of products with AI functions increases, software quality management is being conducted at a national level. In particular, the GS Quality Certification System is a quality certification system for software products that is being implemented at the national level, and the GS Certification System is also researching quality evaluation methods for AI products. In this study, we attempt to present an evaluation model that satisfies the basic conditions of software quality based on international standards among the various quality evaluation models presented to verify software reliability. Considering the software quality characteristics of the artificial intelligence sector, we study quality evaluation models, diagnose quality, and predict failures. .In this study, we propose an international standard model for artificial intelligence based on the software reliability growth model, present an evaluation model, and present a method for quality diagnosis through the model. In this respect, this study is considered to be important in that it can predict failures in advance and find failures in advance to prevent risks by predicting the failure time that will occur in software in the future. In particular, it is believed that predicting failures will be important in various safety-related software.

• Journal of the Korean Society of Safety
• /
• v.32 no.1
• /
• pp.60-65
• /
• 2017

In this study, a simplified FE model for evaluating seismic performance of valve support was suggested and an apparatus for a real structure testing was developed. The seismic performances of three different types of valve supports were evaluated by the real structure testing. By comparing the results between the real structure testing and FEA using the simplified FE model, it was verified that the suggested simplified FE model can be utilized for comparative evaluation of seismic performance of valve supports.

• Journal of computational fluids engineering
• /
• v.20 no.3
• /
• pp.87-93
• /
• 2015

In this study, a numerical analysis was performed to simulate the thermal-hydraulic response of the secondary side of a steam generator(SG) model equipped with an orifice-type SG outlet flow restrictor to a main steam line break(MSLB) at a pressurized water reactor(PWR) plant. The SG analysis model includes the SG upper steam space and the part of the main steam pipe between the SG outlet and the broken pipe end. By comparing the numerical calculation results for the present SG model to those obtained for a simple SG model having no flow restrictor, the effects of the flow restrictor on the thermal-hydraulic response of SG to the MSLB were investigated.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05a
• /
• pp.635-640
• /
• 1998

Thermal fluid mixing behavior during a postulated medium-size hot leg break loss of coolant accident is analyzed for the international comparative assessment study on pressurized thermal shock (PTS-ICAS) proposed by OECD-NEA. The applicability of RELAP5 code to analyze thermal fluid mixing behavior is evaluated through a simple modeling relevant to the problem constraints. Based on the calculation result, the onset of Thermal stratification is investigated using Theofanous's empirical correlation. Sensitivity calculations using a fine node model and crossflow model are also performed to evaluate the modeling capability on multi-dimensional characteristics related to thermal fluid mixing.

• Nuclear Engineering and Technology
• /
• v.54 no.6
• /
• pp.2067-2076
• /
• 2022

The importance of safety culture has been emphasized to achieve a high level of safety. In this light, a systematic method to more properly deal with safety culture is necessary. Here, a decision-making tool that can apply a graded approach to the analysis of safety culture is proposed, called the F-D matrix, which determines the frequency and the difficulty of safety culture attributes recently defined by the IAEA. A hierarchical model of difficulty contributors was developed as a scoring standard, and its elements were weighted via expert evaluation using the analytic hierarchy process. The frequency of the attributes was derived by analyzing reported events from nuclear power plants in the Republic of Korea. Period-by-period comparisons with the F-D matrix can show trends in the change of the maturity level of an organization's safety culture and help to evaluate the effectiveness of previously implemented measures. In the evaluating the difficulty of the attributes in the recently developed harmonized safety culture model, the difficulties of Trending, Benchmarking, Resilience, and Documentation and Procedures were found to be relatively high, while the difficulties of Conflicts are Resolved, Ownership, Collaboration, and Respect is Evident were found to be relatively low. A case study was conducted with an analysis period of 10 years to attempt to reflect the many changes in safety culture that have been made following the Fukushima accident in March 2011. As a result of comparing two periods following the Fukushima accident, the overall frequency decreased by about 40%, providing evidence for the effects of the various improvements and measures taken following the increased emphasis on safety culture. The proposed F-D matrix provides a new analytical perspective and enables an in-depth analysis of safety culture.

• Journal of Advanced Navigation Technology
• /
• v.28 no.1
• /
• pp.95-101
• /
• 2024

This paper aims to establish a reconfigurable flight simulation environment to conduct safety evaluation of various electric vertical take-off and landing (eVTOL) aircraft. Since the inceptor, aircraft dynamics model, and controller applied to each eVTOL aircraft are different, it was configured to be variable so that a simulation can be executed for each eVTOL aircraft. Test elements and performance indicators were set to perform safety evaluation of eVTOL aircraft. Ground auxiliary equipments were designed and implemented in a simulation environment according to test procedures for each test element. In addition, to analyze safety performance, a simulation flight data collection environment based on MATLAB/Simulink and a tool for safety performance analysis were implemented. Test flight and analysis were conducted in the implemented simulation environment in this paper. Finally, this study shows the environment was verified by confirming that it was performed normally.

• Korean Journal of Construction Engineering and Management
• /
• v.5 no.1 s.17
• /
• pp.157-167
• /
• 2004

In developing an automated construction system, it is essential to propose a performance evaluation model and methodology, which can measure productivity, quality, safety and economic feasibility in order to verify its superiority. Recently, a tele-operated hume concrete pipe laying machine has been developed to solve several problems related to safety, quality, productivity in conventional method. The primary objective of this study is to propose a model and methodology for the performance evaluation of the developed tele-operated hume concrete pipe laying machine. Furthermore, this study evaluates the automation machine's performance compared with the existing hume pipe laying work by using data which obtained in many field trials. It is anticipated that the proposed model and methodology might be effectively used in analyzing the performance of other automation robots.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.4
• /
• pp.558-564
• /
• 2021

With the recent introduction of 5G, electromagnetic radiation sources are spreading throughout life, so it is necessary to establish a citizen-centered electromagnetic safety management system. In particular, the beamforming method of the 5G antenna increases the power density measurement of electromagnetic waves by more than 10 times when the wireless base station is installed, so it is unreasonable to determine the safety by physical measurement. Therefore, it is necessary to determine the presence or absence of electromagnetic wave safety in daily life through a predictive method by calculation through systematic model analysis. In this paper, in order to check the possibility of a 5G wireless base station using an electromagnetic wave numerical analysis tool as a way to solve this problem, we compared the measured values of the actual base stations and the predicted values through the prediction model to compare the reliability. A method of constructing a real-time base station electromagnetic wave strength prediction evaluation system combined with software was also proposed.