• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.308-313
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• 2016

Modern systems have become more and more complex due to the ever-increasing user requirements and rapid advance of technology. As such, the frequency of accidents due to system design errors or failure has been increasing. When the damage incurred by accidents to human beings or property is serious, the underlying systems are referred to as safety-critical systems. The development of such systems requires special efforts to ensure the safety of the human beings operating them. To cope with such a requirement, in this paper an approach is employed in which we consider safety starting from the conceptual design phase of the systems. Specifically, a systems design method that can detect functional failure is proposed by utilizing meta-models and M&S methods. To accomplish this, the safety design data from international safety standards are first extracted and also a meta-model is generated using SysML (systems modeling language). Then, a SysML-based system design method is proposed based on the use of the developed meta-model. We also discuss how the safety requirements can be created and verified using a simulation method. Finally, through a case study in automotive design, it is demonstrated that the detection of a functional failure and the verification of a safety requirement can be accomplished using the SysML-based M&S method. This study indicates that the use of meta-models can be useful for collecting and managing safety data and that the meta-model based M&S method can make it possible to satisfy the system requirements by reducing the design errors.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.11-19
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• 2014

Modern systems development becomes more and more complicated due to the need on the ever-increasing capability of the systems. In addition to the complexity issue, safety concern is also increasing since the malfunctions of the systems under development may result in the accidents in both the test and evaluation phase and the operation phase. Those accidents can cause disastrous damages if explosiveness gets involved therein such as in weapon systems development. The subject of this paper is on how to incorporate safety requirements in the design of safety-critical systems. As an approach, a useful system structure using the method of design structure matrix (DSM) is studied while reflecting the need on systems safety. Specifically, the effects of system components failure are analyzed and numerically modeled first. Also, the system components are identified and their interfaces are represented using a component DSM. Combining the results of the failure analysis and the component DSM leads to a modified DSM. By rearranging the resultant DSM, a modular structure is derived with safety requirements incorporated. As a case study, application of the approach is also discussed in the development of a military UAV plane.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2559-2566
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• 2014

Recently, safety accident by misstep at the gap between the platform and railway vehicle have frequently occurred to the mobility handicapped including disabled person, children etc. in metropolitan subway region. Particularly, because the curved platform's gap from platform to railway vehicle is max. 260mm it is important to securement of the passenger's safe mobility right. So it is necessary to platform safety step equipment for needs technology to interface gap between the platform and railway vehicle. In this study we examined the function & production requirements of platform safety step and performed the conceptual design considering the crash safety and maintenance easiness. Moreover, considering various performance requirements we suggested step's operation procedure & control flowchart.

• Journal of the Korean Society of Safety
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• v.14 no.2
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• pp.178-191
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• 1999

More than twenty methods were suggested for Human Reliability Analysis (HRA) in the field of safety analysis for Nuclear Power Plants (NPPs). However, there is still a high uncertainty on the analysis and a difficulty in performing HRA. New methods and approaches are under studying to overcome such limitations of current HRA. This paper presents some results of study to analysis limitations of current HRA in viewpoint of user, i.e., HRA analyst. The limitation analysis was based on 89 human error events modeled in a Probabilistic Safety Assessment (PSA) project for NPPs in Korea. Total 17 specific limitations were identified and categorized into seven groups. Important analysis has also been undertaken to assess the order of priority among those limitations. Finally, seven requirements with priority ranking were generated for an advanced framework and methodology of HRA.

• Journal of Applied Reliability
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• v.16 no.3
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• pp.216-223
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• 2016

Purpose: This paper suggests the procedure to enhance the reliability of the software of the medical device that is to cure, treat, diagnose, and prevent a disease or an abnormal health conditions. Methods: After test requirements are classified by the software requirements specification for safety and backgrounds, reliability assessment methods are suggested. Results: Verification and validation for function and safety can be performed whether the medical device software are implemented as intended. Conclusion: Procedure on the static analysis, unit test, integration test, and system test are provided for the medical device software.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.683-688
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• 2007

The importance of reliability and safety, recently, shows a tendency to increases in railway system constructions and projects. At the point of view of safety, especially, the railway authority proposes an establishment of the safety case that is the documented demonstration that products comply with the specific safety requirements in railway industry. In case of reliability activities, there is no systematic documented demonstration in the railway industry. At this circumstance, this study presents the establishment of Reliability, Availability and Maintainability Case for railway system based on the MoD(Ministry of Defence) 00-42. This RAM Case will support that systems and products produced from suppliers or manufacturers meet the specific RAM requirements during the system life cycle(i.e, from design to operation & maintenance) through systematic process and evidences. Also, it is expected that railway system operations will be managed and supported from reliability activities in accordance with RAM Case.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.136-142
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• 2000

One of the major requirements in preventing Work-related MusculoSkeletal Disorders(WMSDs) is to know definitely what vigorous exertion requirements are contained in a job. This requires improved job analysis tools which can accurately evaluate potentially harmful stresses to the musculoskeletal system. But to simply evaluate the level of stress at a joint, or in a muscle is not enough to motivate job changes. Therefore, the development of ergonomic evaluation tools for the jobs are important to ergonomics. The main objective is compared of the results that made by the ergonomic evaluation tools (e.g., BRIEF and RULA) in actually shoes manufacturing. These were developed in the foreign. So, it is priory needed to research of the ergonomics about Korean characteristic work by physiology and biomechanics.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1566-1573
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• 2008

Generally, a system or service is verified by requirements if it has met them in transforming customer requirements into a system or service. But as the national research and development projects to develope safety systems or standards or process in railway system domain, it can be quite limiting that the product or systems verification process presented the international or industrial standards to be applied. This paper has analyzed and made up for the general verification process and presented the effective and efficient verification process about safety system, safety standard, process, and safety documents and the methods to manage the outcomes of verification process.

• Nuclear Engineering and Technology
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• v.32 no.6
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• pp.537-548
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• 2000

The requirement of ultra high reliability of the safety critical software can not be demonstrated by testing alone. The specification based on formal method is recommended for safety system software. But there exist various kinds of formal methods, and this variety of formal method is recognized as an obstacle to the wide use of formal method. In this paper six different formal method have been applied to the same part of the functional requirements that is calculation algorithm intensive. The specification results were compared against the criteria that is derived from the characteristics that good software requirements specifications should have and regulatory body recommends to have. The application experience shows that the critical characteristics should be defined first, then appropriate method has to be selected. In our case, the Software Cost Reduction method was recommended for internal condition or calculation algorithm checking, and statechart method is recommended for the external behavioral description.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.2
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• pp.106-113
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• 2021

Today, the market and customer requirements for safety-related products in the Railway industry are continuously increasing, and companies that supply these products continue to make related efforts. However, the international standard requirements for making safety-related products are high, so small and medium-sized business companies are having difficulty developing them due to problems in time and cost to achieve them. This study examined government-centered international certificate policies and cases and suggested improvement measures based on the research results. In addition to supporting international certification costs, the government needs to expand technical consulting and expert training for them to solve problems in obtaining an international certificate.