• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.2
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• pp.157-173
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• 1993

Reliability growth modeling can be a requirement when bidding on large military hardware systems. Under current reliability warranty legislature, the reliability growth model can be later translated into necessary reliability performance which must be demonstrated over an extended period of usage. In this paper the modeling situation is concerned with determining the number of spares needed to support a projected reliability growth both at the fightine and in a depot inventory. The model differs from existing models for logistics planning in that we allow for the phenomena of reliability growth. The model can also be used to determine central depot staffing requirements based upon a specified system utilization.

• Journal of Applied Reliability
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• v.7 no.3
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• pp.111-118
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• 2007

In 2000, US Army Test and Evaluation Command (ATEC) released the status of reliability requirement levels and achievements for the military equipment which evaluated through the operational tests from 1985 to 1990 and from 1996 to 2000. The rates of military equipments that do not meet reliability requirements are 59% from 1985 to 1990 and 80% from 1996 to 2000. Thus, the US Army has figured out causes, taken steps and put them into practice, This paper is about the recent reliability problems and the latest tendency about US military equipment to acquirere liability level.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.32 no.3
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• pp.217-246
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• 2021

This study aimed to analyze the quality concepts and requirements of digital records as evidence and to find an implication to develop requirements for trusted digital records with securing authoritative qualities. To this end, this study compared requirements of records domain linking records process, records metadata and records systems with judicial domain on digital evidence, and identified the records requirements to secure the legal admissibility linking records and judicial domain. This study analyzed the relationship of quality concepts between digital records and digital evidence, found the legal admissibility is highly related to the reliability, and derived that it needs the measure to secure the reliability at the stage of records creation and capture. To prove authenticity of digital evidence, this study identified importance of records process, records metadata and records system, and proposed the necessity of measurement to secure records' evidence.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.613-628
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• 2019

In-Vehicle Infotainment provides navigation and various functions through the installation of the application. And infotainment is very important to control the entire vehicle by sending commands to the ECU. Infotainment supports a variety of wireless communication protocols to install and update applications. So Infotainment is becoming an attack surface through wireless communcation protocol for hacker's access. If malicious software is installed in infotainment, it can gain control of the vehicle and send a malicious purpose command to the ECU, affecting the life of the driver. Therefore, measures are needed to verify the security and reliability of infotainment software updates, and security requirements must be derived and verified. It must be developed in accordance with SDL to provide security and reliability, and systematic security requirements must be derived by applying threat modeling. Therefore, this paper conducts threat modeling to derive infotainment update security requirements. Also, the security requirements are mapped to the Common Criteria to provide criteria for updating infotainment software.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.2
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• pp.268-283
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• 2016

Aircraft manufacturing companies have to consider multiple derivatives to satisfy various market requirements. They modify or extend an existing aircraft to meet new market demands while keeping the development time and cost to a minimum. Many researchers have studied the derivative design process, but these research efforts consider baseline and derivative designs together, while using the whole set of design variables. Therefore, an efficient process that can reduce cost and time for aircraft derivative design is needed. In this research, a more efficient design process is proposed which obtains global changes from local changes in aircraft design in order to develop aircraft derivatives efficiently. Sensitivity analysis was introduced to remove unnecessary design variables that have a low impact on the objective function. This prevented wasting computational effort and time on low priority variables for design requirements and objectives. Additionally, uncertainty from the fidelity of analysis tools was considered in design optimization to increase the probability of optimization results. The Reliability Based Design Optimization (RBDO) and Possibility Based Design Optimization (PBDO) methods were proposed to handle the uncertainty in aircraft conceptual design optimization. In this paper, Collaborative Optimization (CO) based framework with RBDO and PBDO was implemented to consider uncertainty. The proposed method was applied for civil jet aircraft derivative design that increases cruise range and the number of passengers. The proposed process provided deterministic design optimization, RBDO, and PBDO results for given requirements.

• Journal of Applied Reliability
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• v.18 no.2
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• pp.161-172
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• 2018

Purpose: Test & Evaluation items are main contents which verify performance of the development system and they are deduced going through project management system stages. However, there is no systematic or standardized framework for Test & Evaluation items, so a lot of differences occur between projects and people are questioning whether verification items are selected for the optimization of the development system. In this regard, this research proposes the process of deducing Test & Evaluation items in a systematic way during a development stage by applying QFD (Quality Function Deployment) technique which reflects customers' requirements. Methods: Test & Evaluation items are recognized as customers' requirements, and QFD technique which refines and gathers various requirements of customers effectively during general products' development stage is applied to complete HOQ (House of Quality) Conclusion: There is no specific methodology for Test & Evaluation items, so currently, they are selected by including items which are given by similar projects or higher authorities. However, by utilizing QFD technique, selection of evaluation items which goes through more systematic process is expected to be possible.

• Journal of Applied Reliability
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• v.14 no.1
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• pp.81-91
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• 2014

The IEC 61508 standard was established to specify the functional safety of E/E/PE safety-related systems. Safety life cycle to provide the framework and direction for the application of IEC 61508 is included in this standard. In this paper, we describe overviews, objects, scopes, requirements and activities of each phase in safety life cycle. In addition, we introduce safety integrity level(SIL) which is used for verifying the safety integrity requirements of E/E/PE system and perform a case study to estimate hardware SIL by FMEDA. The SIL is evaluated by two criteria. One of them is the architectural constraints which restrict the maximum SIL by combination of SFF and HFT. The other is the probability of failure which is classified into PFD and PFH based on frequency of demand and calculated by safe or dangerous failure rates.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.233-236
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• 2005

In this study, the fundamental design procedure for the Smart UAV fuel supply system was set up, and the preliminary design was performed to meet the vehicle system requirements. The fuel system layout was determined through consideration of vehicle system requirements, and then fuel tank layout, design of components such as booster pump, jet pump, pipe, vent system, weight estimation, etc. were carried out.

• Journal of Applied Reliability
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• v.10 no.4
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• pp.237-250
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• 2010

Railway safety aims to ensure that railways take appropriate action to limit the risk of injury to persons or damage to property, to acceptable levels. Accreditation system specifies railway safety requirements to be included in a railway safety management system by any organization seeking to demonstrate the ability to control the processes that determine the acceptability of railway safety activities. The objective of this research is to investigate the international accreditation system for railway safety management. The yield information is quite valuable to operate collaborative processes with all interfacing transport operators and undertakings to facilitate risk control across the railway system.

• 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.