• Journal of the Korea Safety Management & Science
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• v.5 no.4
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• pp.169-185
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• 2003

Recently many researchers contributed to the understanding of Quality Control System, but the use of economics in the design of quality assurance system is limited in treatment of the relationship between the average incoming quality level (or average process quality level) of the incoming lot and the average outgoing quality level of this lot. In this study, a traditional concept of sampling inspection plan for the quality assurance system is extended to a consideration of economic aspects in total production system by representing and analyzing the effects between proceeding and succeeding production process including inspection process. This approach recognizes that the decision at each manufacturing process (or assembly process), is to be determined not only by the cost and the average outgoing quality level of that process, but also by the input parameters of the cost and the incoming quality to the succeeding process. By analyzing the effects of the average incoming and outgoing quality, manufacturing or assembly process quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a general product manufacturing system with specified average outgoing quality limit are suggested.

• Journal of Applied Reliability
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• v.7 no.2
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• pp.89-100
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• 2007

For the certification of aircraft and part, it must be show the compliance with applicable requirements through system safety assessment. The safety assessment process should be planned and managed to provide the necessary assurance that all relevant failure conditions have been identified and that all significant combinations of failures which could cause those failure conditions have been considered. Complex systems, especially aircraft, should take into account any additional complexities and interdependencies which arise due to integration. In all cases involving integrated systems, the safety assessment process is of fundamental importance in establishing appropriate safety objectives for the system and determining that the implementation satisfies these objectives. This study review the safety assessment for the certification process of the aircraft engine system and analyze turbo-fan engine by fault analysis method for compliance with airworthiness requirement of aircraft engine system.

• Journal of Aerospace System Engineering
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• v.11 no.2
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• pp.30-34
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• 2017

This paper is concerned with product assurance for the secondary payload, which is used for technology and science research, in the satellite system, which consists primarily of the spacecraft and the primary payload (a high-resolution optical camera). The Korean satellite development program has successfully insured the safety of the spacecraft and primary payload. However, given the limits of budget and schedule, it is very important to establish adequate product assurance for the secondary payload, which has a lower priority than the spacecraft or primary payload. This paper studies the concept of product assurance for the secondary payload of technological and scientific equipment.

• Journal of Aerospace System Engineering
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• v.6 no.3
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• pp.7-12
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• 2012

The contents of aircraft system safety assessment vary depending on factors such as the complexity of the system, how critical the system is to flight safety, what volume of experience is available on the type of system and the novelty and complexity of the technologies being used. If the system safety assessment is to substantiate that the developed products are 'safe enough' to be taken into use, then the system safety assessment should be planned and managed to provide the necessary assurance that all relevant hazards and failure conditions have been identified and that all significant combinations of hazards and failures which could cause those conditions have been considered. The assessment must assist the designer and management in making decisions. It must make clear what the critical features of each system are and upon which special manufacturing techniques, inspection, testing, crew drills and maintenance practice they are critically dependent. This paper has prepared to study on promoting the efficiency of aircraft system safety assessment and to present how to compile system safety assessment strategy.

• Journal of Aerospace System Engineering
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• v.4 no.1
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• pp.27-31
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• 2010

The scope of this paper is to analyze the safety aspects of the Ka-band payload system which are associated with testing, transportation, integration, handling and storage. According to ESA philosophy and the ECSS-Q-40A "Space Product Assurance - Safety", safety hazard analysis of Ka band payload was performed. In this paper, it is indicated the requirements to be satisfied for eliminating, reducing, or controlling the hazards and by showing how they have been implemented in the COMS design. And it shows the safety hazard analysis result which has performed the analysis according to ESA document and also shows the potential hazard cause, potential effects, hazard grade and criteria resolution of Ka band COPS.

• International Journal of Safety
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• v.10 no.2
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• pp.16-20
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• 2011

The computer application on embedded system is recently more increased in accordance of the development of computer technology. In this trend, the depending of SW in embedded system, especially railway signaling system, is being increased further. So the testing for the safety of railway signaling system software became more important. Hence, the safety assurance of the vital software on the railway signaling system is very important but yet, not many works have been done. In this paper, we represented the implementation results of development of performance testing tool in railway signaling system. The implemented testing item had referred to the international standards in relation to the software for railway system, such as IEC 61508 and IEC 62279.

• Journal of the Korean Society of Safety
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• v.22 no.5
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• pp.71-76
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• 2007

Failures of equipments for train control systems are linked directly to extensive damages of human lives or financial losses from the increasing uses of train control equipments utilizing computers. Then safety activities for assuring safety and reliability are needed during the system life-cycle. Risk analysis is important phase to increase safety from determining the risk presented by the identified hazard. In this paper, we investigated several methods for risk estimation of safety activities, and then we drew a comparison between original methods to suggest optimized one in the application to train control systems. In the result of the comparison, we had plan to propose the risk analysis method called Best-Practice(BP) risk method combining advantages of the qualitative and the quantitative analysis. In addition, we attempted to apply the BP-risk method to domestic train control systems handling in Korea.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.35-42
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• 2008

There are many efforts toward the development of next generation gas safety management systems to improve the assurance, availability, and efficiency of the extant systems. Among them, the application of ubiquitous technology, such as RFID and USN, to the system is regarded as a promising approach for enabling such an innovation. Recently the ubiquitous technology became much affordable and available than before thanks to the reduced production cost and wide proliferation of the ubiquitous devices. In this paper, we analyze the core requirements for the next generation gas safety management systems based on the ubiquitous technology, and present an architectural design of a middleware to facilitate the realization of the system. We formally define an event model and present how to specify various situations related to gas safety management using the proposed event model.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1959-1962
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• 2009

In this paper, we derive the hazard which is a criterion of safety assurance by PHA for the ATP equipped in Korea Tilting Train. The ATP onboard equipment in Korea Tilting Train was introduced as ETCS Level l(which is ETCS specification). Also, the ATP trackside equipment was introduced as a ETCS SRS(System Requirement Specification) 2.2.2 and it has a target for commercial operation in 2009 late. In IEC 62278(EN50126), it recommend of PHA to derive a hazard of target system in concept establishment step and estimate if it can control as a tolerable level and then derive safety case to control the hazard by lifecycle. Therefore, we indicate the hazard using criterion of safety assurance by PHA using FRS (Functional Requirement Specification) 5.0. which is a upper criterion than SRS. The hazard of ATP onboard equipment derived in Korea Tilting Train will be able to use as ATP functional hazards of unified onboard equipment in G7 which is a multiple unit and preliminary hazards of ATP onboard equipment in NEL drived by Korail.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.2
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• pp.95-100
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• 2009

Recent advances in computer technology have brought more dependence on software to railway systems. Hence, the safety assurance of the vital software running on the railway system is very critical task and yet, not many works have been done. While much efforts have been reported to improve electronic hardware's safety, not so much systematic approaches to evaluate software's safety. In this paper, we suggested an automated analysis tool for S/W change impact in railway system, and presented its result of implementation. The analysis items in the implemented tool had referred to the international standards in relation to the software for railway system, such as IEC 61508 and IEC 62279. In these international standards, 'change impact analysis' for railway system S/W has to be required mandatorily. The proposed tool can be utilized at the assessment stage and also the software development stage.