• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.915-917
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• 1998

Optimal routing of distribution networks can be attained by keeping the line power capacity limit to handle load requirements, acceptable voltage at customer loads, and the reliability indices such as SAIFI, SAIDI, CAIDI, and ASAI limits. This method is composed of optimal loss reduction and optimal reliability cost reduction. The former is solved relating to the conductor resistance of all alternative routes, and the latter is solved relating to the failure rate and duration of each alternative route. The routing considering optimal loss only and both optimal loss and optimal reliability cost are compared in this paper. The results showed that reliability cost should be considered as well as loss reduction to achieve the optimal routing in the distribution networks.

• International Journal of Automotive Technology
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• 제4권3호
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• pp.135-140
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• 2003

In the deterministic optimization of a structural system, objective function, design constraints and design variables, are treated in a nonstatistical fashion. However, such deterministic engineering optimization tends to promote the structural system with lest reliability redundancy than obtained with conventional design procedures using the factor of safety. Consequently, deterministic optimized structures will usually have higher failure probabilities than unoptimized structures. Therefore, a balance must be developed between the satisfactions of the design requirements and the objectives of reducing manufacturing cost. This paper proposes the reliability-based design optimization (RBDO) technique, which enables the optimum design that considers confidence level for the vibration characteristics of structural system. Response surface method (RSM) is utilized to approximate the performance functions describing the system characteristics in the RBDO procedure. The proposed optimization technique is applied to the pillar section design considering natural frequencies of a vehicle structure.

• 정보처리학회논문지D
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• 제8D권3호
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• pp.247-256
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• 2001

소프트웨어는 갈수록 대규모화, 다기능화되는 방향으로 발전하고 있다. 더불어 소프트웨어에 관한 사용자의 요구 수준도 높아지고 있으며 특히 소프트웨어의 품질에 대한 요구는 지속적으로 높아지고 있다. 이러한 사용자의 요구를 만족시킬 수 있는 방안들이 다양한 관점에서 연구되고 있다. 그 중에서도 소프트웨어의 품질평가를 통해 그 결과를 개발자에게 피드백함으로써 소프트웨어의 품질을 향상시키려는 관점에서 품질평가 체계 및 방법론에 대한 연구가 활발히 진행되고 있다. 본 논문에서는 소프트웨어의 품질에 관한 국제표준인 ISO/IEC 9126의 품질특성 중 신뢰성에 대한 품질특성, 부특성, 내부특성의 체계에 따른 메트릭과 품질측정표를 개발함으로써 관련 내부특성의 품질평가를 통해 신뢰성에 대한 평가 결과를 산출할 수 있는 체계를 확립하고 내부특성을 이용하여 개발산출물에 대해 평가한 결과를 제시하였다.

• 기록학연구
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• 제10호
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• pp.3-26
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• 2004

ISO 15489:2001 addresses the principles and requirements with which organizations, both public and private, should comply on the management of their records to ensure that adequate records are created, captured and managed. The standard defines the characteristics that a record should have through records management system as follows: authenticity, reliability, integrity, and usability. Authenticity means that records can be proven to be what it purports to be, to have been created or sent by the person purported to have created or sent it, and to have been created or sent at the time purported. Reliability means that the contents of the records can be trusted as a full and accurate representation of the transactions, activities or facts to which they attest and can be depended upon in the course of subsequent transactions or activities. Integrity refers to ensuring that a record is complete and unaltered. Usability means that records can be located, retrieved, presented and interpreted. In order to have these characteristics, a record should be persistently linked to the metadata necessary to document a transaction. Metadata is "data describing context, content and structure of records and their management through time." Metadata ensure the creation and maintenance of authentic, reliable and usable records and the protection of the integrity of those records. It could be implemented by creating and capturing records management metadata in systems that create and manage records. There have been some projects and standard initiatives to identify a core set of records management metadata. Included are the Australian Recordkeeping Metadata Standard and the British Metadata Standard which is part of the Requirements for Electronic Records Management System. Recently ISO/TS 23081-1 is published to implement metadata requirements within the framework of ISO 15489. Public records management system in Korea is ruled by the Act on the Management of Archives by Public Agencies and Administrative Records Management Regulation. This article evaluates records and their descriptive elements captured and maintained by the records management system in Korea on the basis of the international metadata standards.

• 한국항행학회논문지
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• 제22권4호
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• pp.264-270
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• 2018

최근에 미국 또는 유럽 등에서 개발되거나 해당 국가의 영공에 취항하기 위한 민간 항공기에는 RTCA (radio technical commission for aeronautics)에서 발표하고 미연방항공국 (Federal Aviation Administration)에서 인정한 DO-178에 따른 탑재 소프트웨어 신뢰성 검증이 요구된다. 이는 각 분야에서 소프트웨어에 대한 의존이 날로 심화되는 가운데 사고 발생시 경제적, 사회적으로 치명적인 영향이 발생하는 민간 항공 분야에서 먼저 소프트웨어 신뢰도 향상을 위한 노력이 진행되었기 때문이다. 이 논문에서는 소프트웨어 신뢰도 향상을 위해 DO-178에서 요구하고 있는 요구사항 기반의 신뢰성 검증을 위해 선결되어야 할 요건들을 파악하고, 현재 방위사업청의 무기체계 획득 절차에 기반 하여 각 획득 단계에 맞는 점검 요소들을 분석하여 제시하였다. 또한 해외에서 축적된 정보를 바탕으로 식별된 주요 점검요소를 국내 항공기 개발 사업에 적용하고 적용결과를 분석하였다. 본 연구 결과 현재의 무기체계 획득 절차에 개발 단계별 소프트웨어 점검 요소를 추가하고 객관적 점검 기준을 제시하는 것으로 DO-178에 따른 요구사항 기반 소프트웨어 신뢰성 점검에 대한 개발관리가 가능한 것으로 확인되었다.

• 품질경영학회지
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• 제48권1호
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• pp.187-199
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• 2020

Purpose: This study suggests how to upgrade performance certification technology. Current performance certification of aviation security equipment and the requirements thereof were analyzed. Methods: The performance certification of aviation security equipment worldwide and identified issues with the domestic certification system were compared. The government must upgrade certification in terms of technical standards, the assessment methodology used, and the operating system. Results: Three principal conclusions were drawn. First, certification requirements must be based on a review of the technical literature and real-world experience. Second, development priorities must be set by reference to assessment techniques. Third, both research on the certification system and improvements thereof are essential. Conclusion: Certification of aviation security equipment performance requires gradual upgrading.

• 시스템엔지니어링학술지
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• 제2권1호
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• pp.31-36
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• 2006

Development of launch vehicle needs a large-scale and complicated System Engineering discipline interfacing to small-quantity production with special manufacturing processes. In general, the System Engineering discipline of launch vehicle has its relationship with Production, Operations, Product Assurance and Management disciplines and its internal partitions into the functions of System Engineering Integration & Control, Requirements Engineering, Analysis, Design and Configuration and Verification. As a function of Product Assurance, reliability of launch vehicle plays an significant role in risk management, system safety, flight safety and launch certification through design assurance. Moreover, major functions of systems engineering are integrated by means of reliability in the phases of design and verification. Therefore, derailed identification of system engineering interfaces of reliability, and execution of tasks for reliability assurance is required for successful development of launch vehicle. This paper identifies specific pattern and mechanism of the interfaces between reliability and system engineering.

• Journal of information and communication convergence engineering
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• 제20권2호
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• pp.79-89
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• 2022

To compute the mean and variance of component-based reliability software, we focused on path-based reliability analysis. System reliability depends on the transition probabilities of components within a system and reliability of the individual components as basic input parameters. The uncertainty in these parameters is estimated from the test data of the corresponding components and arises from the software architecture, failure behaviors, software growth models etc. Typically, researchers perform Monte Carlo simulations to study uncertainty. Thus, we considered a Markov chain Monte Carlo (MCMC) simulation to calculate uncertainty, as it generates random samples through sequential methods. The MCMC approach determines the input parameters from the probability distribution, and then calculates the average approximate expectations for a reliability estimation. The comparison of different techniques for uncertainty analysis helps in selecting the most suitable technique based on data requirements and reliability measures related to the number of components.

• 한국신뢰성학회지:신뢰성응용연구
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• 제10권3호
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• pp.161-169
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• 2010

Automobiles have become part of our lives in modern society. But since they can be detrimental once problems occur on the road safety requirements are stringent. In this paper DFSS procedure is applied to the establishment of headliner safety. Specifically, IDDOV is employed where problems are identified, areas for development clarified, optimization realized, and finally optimal conditions verified at the final stage.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.824-829
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• 1998

In regard to the very stringent-going requirements applied to power supply systems is nowadays applications, the reliability of typical UPS redundency systems are investigated. Several resonable assumptions are made to build up the probability models. The reliabilities of the typical UPS redundency systems are analysed. Their relating Relaibility and MTTF (Mean Time To Faults) are evaluated. It is resulted in that the MTTF of today's UPS redundency systems is unlikely to be beyond 1,000,000 hours.