• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.12
• /
• pp.1193-1200
• /
• 2008

The procedure of design for reliability which consists of reliability analysis and Failure Modes and Effects Analysis(FMEA) is established and reliability assesment is performed for the nano-satellite air-launching rocket, Mirinae II. By means of using the reliability analysis result, the feasibility to insert the Mirinae II to the target orbit for given mission time under operating environment is assessed. During the reliability analysis process, the system is categorized by Work Breakdown Structure(WBS), and reliability structure is defined by both Reliability Block Diagram(RBD) and schematics of the system. FMEA is used to determine the risk priority number of components and parts. The target reliability is satisfied by changing the design of components and parts with high-risk, hence the design for reliability to put the satellite in to the target orbit safely has been performed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.5
• /
• pp.1040-1048
• /
• 2016

Recently, the studies of integrated reliability analysis for combat systems are actively progressing. Especially, the research of integrated reliability analysis is emphasized to overcome limitations of the previous studies. In this paper, we propose a calculation technique for integrated hit probability based on front and side hit probabilities that analyzed in previous studies to improve the time-effectiveness. Also, we find out the integrated reliability of each component based on the integrated hit probability which is calculated, and we propose the method which applied the reliability block diagram technique to analyze the whole combat system of the reliability by function kills. For verifying the proposed method, we applied the proposed method to armored fighting vehicle model. The proposed method considers crew which does not considered the element in the previous study and expects to enhance the accuracy of reliability analysis and the time-effectiveness compared with the previous study.

• Journal of the Korean Society for Railway
• /
• v.10 no.5
• /
• pp.527-532
• /
• 2007

In this paper, we suggest those two design plans for power supply method of Hot Standby Sparing System; one is the plan using MTBF based on Constant Failure Rate, and the plan using Reliability Function is the other. Traditionally, RBD (Reliability Block Diagram) is used for reliability prediction which is required to meet any requirements before system operation. However, the system that has redundancy, such as Hot Standby Sparing System, Is not suitable for system reliability modeling using combination model, such as RBD. In this paper, therefore, we demonstrate that for redundancy controller, redundancy modeling design toward fault occurrence design is more effective to build up a system with higher reliability and achieve the effectiveness of loss cost due to maintenance and failure occurred in operation, rather than combinational modeling design.

• Journal of the Korean Society of Systems Engineering
• /
• v.17 no.1
• /
• pp.1-10
• /
• 2021

In this paper we proposed the alternative analysis of reliability design using redundancy technique. First, we presented the process for establishing the reliability design alternative analysis process considering the active redundancy and the standby redundancy. and then, the case analysis of A driving equipment was performed in accordance with the reliability design alternative analysis process presented. In case the series reliability design result is not met with the reliability target value. so, the target item for redundancy design of A driving equipment were selected as items with a severity of two or higher. The redundancy design applied with active and standby redundancy techniques were analyzed using BlockSim software. As a result, it was analyzed that reliability design to active redundancy with one of two elements required for A driving equipment is the most efficient compared to the target value of reliability. The results of this study can be usefully used before the reliability design is performed.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.133-136
• /
• 2003

In these days, the reliability analysis and prediction are applied for many industrial products and many products require guaranteeing the quality and efficiency of their products. In this study reliability prediction for core units of machine tools has been performed in order to improve and analyze its reliability. ATC(Automatic Tool Changer) and interface Card of PC-NC that are core component of the machine tools were chosen as the target of the reliability prediction. A reliability analysis tool was used to obtain the reliability data(failure rate database) for reliability prediction. It is expected that the results of reliability prediction be applied to improve and evaluate its reliability. Failure rate, MTBF (Mean Time Between Failure) and reliability for core units of machine tools were evaluated and analyzed in this study.

• Journal of the Korean Society for Railway
• /
• v.10 no.3 s.40
• /
• pp.319-326
• /
• 2007

During the design phase of a system, which requires high reliability and safety such as aircraft, high speed train and nuclear power plant, reliability engineer must set up the target system reliability. To meet a reliability goal for the system, reliability allocation should be done gradually from the system to its element. For this end, first of all, we need to construct functional block diagram based on the design output and PWBS(Project Work Breakdown System). Another important input data for reliability allocation is the relationship between the cost and the reliability. In this study we investigate various reliability allocation models, which can be applicable to aircraft, vehicle, and power plant, and etc. And we suggest a proper reliability allocation model which can be effectively applicable to KTX-II high speed train to achieve the target system reliability.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.45-57
• /
• 2007

During the design phase of a system, which requires high reliability and safety such as aircraft, high speed train and nuclear power plant, reliability engineer must set up the target system reliability. To meet a reliability goal for the system, reliability allocation should be done gradually from the system to its element. For this end, first of all, we need to construct functional block diagram based on the design output and PWBS(Project Work Breakdown System). Another important input data for reliability allocation is the relationship between the cost and the reliability. In this study we investigate various reliability allocation models, which can be applicable to aircraft, vehicle, and power plant, and etc. And we suggest a proper reliability allocation model which can be effectively applicable to KTX-II high speed train to achieve the target system reliability.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.14 no.1
• /
• pp.88-96
• /
• 1989

General measure in the reliability is the k-terminal reliability, which is the probability that the specified vertices are connected by the working edges. To compute the k-terminal reliability components are usually assumed to be statistically independent. In this study the modeling and analysis of the k-terminal reliability are investigated when dependency among components is considered. As the size of the network increases, the number of the joint probability parameter to represent the dependency among components is increasing exponentially. To avoid such a difficulty the structured-event-based-reliability model (SERM) is presented. This model uses the combination of the network topology (physical representation) and reliability block diagram (logical representation). This enables us to represent the dependency among components in a network form. Computational algorithms for the k-terminal reliability in SERM are based on the factoring algorithm Two features of the ractoring algorithm are the reliability preserving reduction and the privoting edge selection strategy. The pivoting edge selction strategy is modified by two different ways to tackle the replicated edges occuring in SERM. Two algorithms are presented according to each modified pivoting strategy and illustrated by numerical example.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.30 no.1
• /
• pp.1-7
• /
• 2007

This paper addresses a the maintenance system based on the concept of RAMS (Reliability, Availability, Maintenance, Safety) for the effective maintenance of the urban transit. A systematic approach for developing a cost-effective maintenance strategy based on the component reliability of the system in question is performed according to the following steps : definition of function, functional failures of the systems, construction of RBD (Reliability Block Diagram), and the calculation of reliability indices. The developed preventive maintenance system generates maintenance plan and repair request based on the analysed RAMS data of components and maintenance experience.

• Journal of Wind Energy
• /
• v.9 no.4
• /
• pp.5-8
• /
• 2018

Optimum performance and reliable operation of wind turbines and/or wind farms are crucial parameters for stakeholders such as OEMs, operators, owners and investors. The efficiency and life time of wind power heavily depends on operation and maintenance efforts. Every manufacturer or owner wants to have wind turbines with high reliability, which can be defined as the probability that a wind turbine will perform its designed function for a certain period of time under stated conditions. In this regard, IEC WG26 is now developing a technical specification defining information categories from which reliability metrics can be identified and reported.