• Journal of the Korea Safety Management & Science
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• v.10 no.3
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• pp.81-87
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• 2008

The reliability prediction and evaluation for general electronic components are required to guarantee in quality and in efficiency. Although many methodologies for predicting the reliability of electronic components have been developed, their reliability might be subjective according to a particular set of circumstances, and therefore it is not easy to quantify their reliability. In this study reliability prediction of electronic components, that is the interface card, which is used in the CNC(Computerized Numerical Controller) of machine tools, was carried out using PRISM reliability prediction specification. Reliability performances such as MTBF(Mean Time Between Failure), failure rate and reliability were obtained, and the variation of failure rate for electronic components according to temperature change was predicted. The results obtained from this study are useful information to consider a counter plan for weak components before they are used.

• Journal of Korean Society for Quality Management
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• v.35 no.2
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• pp.27-36
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• 2007

A study to build a reliability model of electronic ballasts for the fluorescent lamp has been performed in this study. We selected the widely being used specification, MIL-HDBK-217 for the study. We briefly reviewed the basic concepts of the electronic ballast with the selected reliability specification. We then developed a reliability model for the ballast using MIL-HDBK-217 and predicted the reliability. We further provided some guides which should be considered in future model development.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.327-332
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• 2006

A study to build a reliability model of electronic ballasts for the fluorescent lamp has been performed in this paper. We selected the widely being used specification, MIL-HDBK-217 for the study. We briefly reviewed the basic concepts of the electronic ballast with the selected reliability specification. We then developed a reliability model for the ballast using MIL-HDBK-217 and predicted the reliability.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.4
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• pp.467-478
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• 2003

Automotive shock absorber may not be regarded as only one(simple) damping machine because it is composed of many components, and shows non-linear damping characteristics. No matter how advanced form of shock absorber is developed, the oil shock absorber can not be neglected. because their structures are based on the oil shock absorber. Therefore it is essential to accurately analyze the dynamic characteristics of oil shock absorber. It stands mainly roi damper valve tuning which nowadays is still exhaustively done by means of ride work. In this study, damping mechanism and dynamic characteristics for oil shock absorber of twin tube type are analyzed, based on the mathematical model considering internal flow and pressure. For the reliability of numerical prediction. the database is constructed within the limit of adequate reliability. Finally, the programmed system that gives out necessary specification by inputting damping specification and tolerance is to be constructed.

• IE interfaces
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• v.25 no.4
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• pp.472-479
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• 2012

Before an aircraft is delivered to customers, manufacturers have to verify required reliability for the aircraft. In usual, reliability of electronic equipments in military aircraft are predicted based on MIL-HDBK-217. But the specification has not been revised since 1995. Some alternatives including SR-332 and 217PLUS are suggested in this study. The processes and methods specified in MIL-HDBK-217 are compared with those of SR-332. Additionally, the predicted reliability of aircraft electronic equipment between usage data and field data are investigated using MIL-HDBK-217. The results show that predicted reliability of MIL-HDBK-217 is more conservative (underestimated) than that of usage data and field data.

• Journal of Power Electronics
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• v.6 no.2
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• pp.104-113
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• 2006

Satellites have provided the impetus for the orderly development of reliability engineering research and analysis because they tend to have complex systems and hence acute problems. They were instrumental in developing mathematical models for reliability, as well as design techniques to permit quantitative specification, prediction and measurement of reliability. Reliability engineering is based on implementing measures which insure an item will perform its mission successfully. The discipline of reliability engineering consists of two fundamental aspects; $(1^{st})$ paying attention to details, and $(2^{nd})$ handling uncertainties. This paper uses some of the basic concepts, formulas and examples of reliability theory in application. This paper emphasizes the practical reliability analysis of a Low Earth Orbit (LEO) Micro-satellite power subsystem. Approaches for specifying and allocating the reliability of each element of the power system so as to meet the overall power system reliability requirements, as well as to give detailed modeling and predicting of equipment/system reliability are introduced. The results are handled and analyzed to form the final reliability results for the satellite power system. The results show that the Electric Power Subsystem (EPS) reliability meets the requirements with quad microcontrollers (MC), two boards working as main and cold redundant while each board contains two MCs in a hot redundant.

• Journal of Applied Reliability
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• v.12 no.1
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• pp.1-12
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• 2012

The quality of a part has directly effect on part reliability. In the basis of MIL-HDBK-217F model, it is the determined rule that part's quality level should follow its nominal one written in its specification. If quality information is unknown, quality level of the part should be determined as 'Lower'. However, the prediction model is said to be short in reflecting parts applying 'state-of-the-art' technology and result in over-estimated failure rate by some reliability-related authorities or research institutes. In this study, the reliability prediction results by the model of MIL-HDBK-217F and Telcordia SR-332 are compared and analyzed to verify whether the statement is reasonable or not.

• Journal of KIISE:Software and Applications
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• v.29 no.12
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• pp.926-939
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• 2002

The formal specification methods with probability have been demanded in the area of fault real-time systems, in order to specify the uncertainty that the systems can encounter during their execution due to various environmental factors. This paper presents a new formal method with probability. namely Probabilistic Abstract Timed Machine (PATM), in order to analyze and predict system's behavior in dynamical environmental changes, This method classifies the factors into two classes: the variable and the constant. The analysis of system's behavior is performed on the probabilistic reachability graph generated from the ATM specification for the system. The analysis can predict any possibility that the behavior may not satisfy some safety requirements of the system, indicate which variable factors cause such satisfaction, and further recover from this unsatisfying fault state by fixing the variable factors. Consequently the reliability to the fault real-time systems can be improved.

• Journal of Aerospace System Engineering
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• v.18 no.2
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• pp.21-28
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• 2024

In light of the rapid development of the space industry, there has been increased attention on small satellites. These satellites rely on components that are considered to have lower reliability compared to larger-scale satellites. As a result, predicting reliability becomes even more crucial in this context. Therefore, this study aims to compare three reliability prediction techniques: MIL-HDBK-217F, RiAC-HDBK-217Plus, and FIDES. The goal is to determine a suitable reliability standard specifically for nano-satellites. Furthermore, we have refined the quality assurance factors of the manufacturing company. These factors have been adjusted to be applicable across various industrial sectors, with a particular focus on the selected FIDES prediction standard. This approach ensures that the scoring system accurately reflects the suitability for the aerospace industry. Finally, by implementing this refined system, we confirm the impact of the manufacturer's quality assurance level on the total failure rate.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.1
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• pp.83-104
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• 2011

Mobile grid is a combination of grid computing and mobile computing to build grid systems in a wireless mobile environment. The development of network technology is assisting in realizing mobile grid. Mobile grid based on established grid infrastructures needs effective resource management and reliable job scheduling because mobile grid utilizes not only static grid resources but also dynamic grid resources with mobility. However, mobile devices are considered as unavailable resources in traditional grids. Mobile resources should be integrated into existing grid sites. Therefore, this paper presents a mobile grid middleware interconnecting existing grid infrastructures with mobile resources and a mobile service agent installed on the mobile resources. This paper also proposes a mobile resource reliability-based job scheduling model in order to overcome the unreliability of wireless mobile devices and guarantee stable and reliable job processing. In the proposed job scheduling model, the mobile service agent calculates the mobile resource reliability of each resource by using diverse reliability metrics and predicts it. The mobile grid middleware allocated jobs to mobile resources by predicted mobile resource reliability. We implemented a simulation model that simplifies various functions of the proposed job scheduling model by using the DEVS (Discrete Event System Specification) which is the formalism for modeling and analyzing a general system. We also conducted diverse experiments for performance evaluation. Experimental results demonstrate that the proposed model can assist in improving the performance of mobile grid in comparison with existing job scheduling models.