Purpose: The purpose of this study is to provide a comparison of reliability prediction models between MIL-HDBK-217F and Telcordia SR-332 and to analyze the reliability prediction results. Methods: The reliability of industrial tablet PC was predicted using MIL-HDBK-217F and Telcordia SR-332. To analyze the results, sensitivity analysis was conducted. Results: The reliability of MIL-HDBK-217F was predicted lower than the one of Telcordia SR-332. Considering the factors such as temperature, quality and environment, those provided reliability change of a particular part which highly contribute to the system failure. Conclusion: It is necessary to design the industrial tablet PC that consists of integrated circuits such as microprocessor and memory considering the operating temperature and quality factors.

Purpose: The purpose of this study was to develop the accelerated life test method for Constant Electrical Potential Electrolysis gas sensor (CEPE gas sensor). Methods: The parts and modules of CEPE gas sensor were analyzed by using Reliability Block Diagram (RBD). Failure Mode and Effect Analysis (FMEA) and Quality Function Deployment (QFD) methods were performed for each part to determine the most affecting stress factor in its life cycle. The long term testing was conducted at three different dry heat levels and the acceleration factor was developed by using Arrhenius relationship. Conclusion: The acceleration factor for CEPE gas sensor was developed by using FMEA, QFD, and statistical analysis for its failure data. Also qualification tests were designed to meet the target life.

Purpose: In this paper, we propose the output model of the optimal inventory requirements of the Maintenance Float (M/F). Weapon systems were modernized and increased costs. Thus, the complexity increases with. Alternatives to achieve the goal of availability of weapon systems and to reduce life-cycle cost are required. Especially, securing spare parts is more effective than adding the amount of equipment or maintenance facilities to achieve the goal of availability and reduce life cycle costs. However, securing spare parts and repair costs are directly related, so exact requirements are needed. Methods: Three kinds of methods (Calculation method of applying the Poisson distribution, Calculation method of considering the number of CSP, and Calculation method of applying M&S program) that this paper proposed compare the influence of the availability and the amount of spare parts. Result: We calculate the cost of M/F when the operational availability is over than 80% and compare that result. The biggest cost was calculated from the Poisson distribution method. We found that requirements and unit price is the key factor that gives a significant effect. Conclusion: These three kinds of methods can be used as a basis for Maintenance Float calculation. Among them, the calculation method based on CSP is optimal replacement equipment requirements calculation method.

Purpose: The purpose of this study is main factors (environmental conditions, pattern spacing, pattern material) that effect the ion-migration of PCB. Methods: Recently, the electronic components are becoming more high density of electronic device, so that electronic circuits have smaller pitches between the patten and more vulnerable to insulation failure. so the reliability of electric insulation of device has become an ever important issue as device contact pitches of pattern. Usually, ion-migration occurs in high temperature and high humidity environment as voltage is applied to the circuit. Under high temperature and high humidity, voltage applied electronic components respond to applied voltages by metals's electrochemical ionization and a conducting filament forms between the anode and cathode across a nonmetallic medium. This leads to short-circuit failure of the electronic component. Results: we studied ion-migration that occurs in accordance with the main factors (environmental conditions, pitches, pattern material). The PCB pattern material was made by two different types of material (free solder, OSP) for this research and pitches of pattern is 0.15mm, 0.3mm, 0.5mm. PCB was experimented in the environmental conditions (high temperature $120^{\circ}C$, high temperature and high humidity $85^{\circ}C$, 85%RH) and was analyzed for ion-migration through the experiment results. Conclusion: We confirmed that environmental condition, pitches of pattern, pattern material had effect on ion-migration of PCB.

Purpose: ASRP for the domestic development guided missiles requires not only for the reliability evaluation of the products in storage but also for the life cycle management of the products including development prototypes and initial production items. Methods: For this purpose, it should be performed to build a performance database before and after the accelerated aging test with shelf life items including development prototypes and initial production items, based on which the lifetime prediction should also be carried out. In addition, HILS must be applied for the acceptance test with the initial and follow-up production items, and also for ASRP for the long-term storage products in order to secure systematic quality assurance. Results: The results for the life cycle reliability Improving of domestic development of guided missiles are DB building of prescription Item performance, active application of HILS, Management associated with guided missiles life cycle and to Secure technology data about the introduction of foreign guided missiles. Conclusion: Furthermore, it is demanded that DTaQ, the managing agency of ASRP, actively take part in the process to maintain reliability engagement consistency over the life cycle of guided missiles.

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.

Purpose: Military maintenance involves corrective and preventive actions carried out to keep a system in or restore it to a predetermined condition. This research develops an optimal maintenance cycle for aviation oil testing equipment with acceptable reliability level and minimum maintenance cost. Methods: The optimal maintenance policy in this research aims to satisfy the desired reliability level at the lowest cost. We assume that the failure process of equipment follows the power law non-homogeneous Poisson process model and the maintenance system is a minimal repair policy. Estimation and other statistical procedures (trend test and goodness of fit test) are given for this model. Results: With time varying failure rate, we developed reliability-based maintenance cost optimization model. This model will reduce the ownership cost through adopting a proactive reliability focused maintenance system. Conclusion: Based on the analysis, it is recommended to increase the current maintenance cycle by three times which is 0.5 year to 1.5 years. Because of the system's built-in self-checking features, it is not expected to have any problems of preventative maintenance cycle.

Purpose: It is not easy to suggest a quantitative data related to safety analysis. The objective of this paper is to propose a method of Safety Integrity Level (SIL) analysis and to suggest a SIL analysis result for single station controller in nuclear power plant based on IEC 61508. Methods: The Failure Modes and Effects Diagnostic Analysis (FMEDA) and average probability of failure on demand (PFD) are used for SIL assessment. Results: A SIL of single station controller is evaluated 4 by a reliability analysis results and PFD. Conclusion: A SIL analysis method and result for single station controller based on IEC 61508 are proposed in this paper. It can applicable for a manufacturer data in safety-related system.

Purpose: Domestic electric railway Regenerative Energy Storage System seriously affects the maintenance cost of the total operating expenses of nearly 60% of the total LCC (Life Cycle Cost) due to high dependence on foreign Leading company. Therefore by developing the system, it is important to lower the maintenance cost in the domestic supply. This study about the capacitor Reliability test and the purpose of this study is development electric railway Regenerative Energy Storage System. Methods: In case of, having a close relation between the temperature and the reaction rate, Accelerated Model was known that according to Arrhenius' law of chemical activity. If you apply this formula in using allowable temperature range of the capacitor can induce the Arrhenius empirical formula used in much Manufacture Fields. We evaluate the capacitors Leading company through the Arrhenius model. in order to providing a base for the localization of Ultra Capacitor. Conclusion: In this paper, we conducted a reliability test. And it was performed by the accelerated life test and Cycle Test with temperature and C-rate. and then MTBF and B10 life are estimated by analyzing the accelerated life test result. This is thought to need detailed study applying complex stress than about whether it matches the actual behavior in electric railway.

Purpose: The purpose of this study is to measure the reliability of complex equipment. Reliability of product is one of the most important factor to achieve competitiveness in the market. While there were many researches for assessing the reliability on components and modules, research on quantitative assessment tool for equipment with many component was little because of equipment's complexity. Methods: In this article, we developed index to assess reliability management system by using IEC 60300 and Reliability Management Tool-kit. With MIR and BARS, we developed reliability index clauses relevant to reliability activities and found weight factor for each clause by survey on experts. Results: The results of this study were as follows; reliability index that can assess both management side and technology side of the company was developed. Conclusion: Using this index, we assessed the reliability of a manufacturing equipment and found out the current reliability level of the manufacturing equipment, and derived improvement points.

Recently, the subject of reliability attracts a great deal of domestic and international attentions and the extensive research activities are being conducted as well. Such trend exists mainly due to the fact that the research on the subject of reliability not only contributes to the theoretical developments, but also may find a wide range of applications in practice over several fields. In particular, the research regarding the maintenance policy incorporating certain types of warranty for repairable system and its application is being performed extensively by many researchers, and their efforts seem more concentrated on developing new maintenance policies which minimize the expected operating cost incurred for replacement and repair of the system, while keeping the system at high reliability. Effective maintenance policy may reduce the operating cost and decrease the downtime of the system during its mission period and consequently, increase the productivity of the system. In this article, the major areas of interest in the field of reliability and its historic perspectives are given briefly and the theoretical aspects in several fields of reliability including the maintenance and warranty policies is also discussed. Furthermore, the current domestic situation regarding the education and research on reliability is presented, along with the importance of reliability theory and the difficulty of training reliability personnel. Finally, the author's opinion for effective education system is proposed.