• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.13 no.22
• /
• pp.59-64
• /
• 1990

This paper is aimed to study the standby redundant system with the relay of parallel structure, by making use of the character of standby system, which reliability is higher than parallel system's if the relay has higher reliability than a certain level. By assigning the low-priced relay to the subsystem, this method increases the relay reliability, optimizes the standby redundant system reliability without violating the restrictions, and consequently reduces the cost.

• Journal of Korea Society of Industrial Information Systems
• /
• v.20 no.4
• /
• pp.75-87
• /
• 2015

A redundant structure typically consists of primary component and standby component taking over the function of the primary component when the primary component fails. In this research, we consider a redundant structure in which a standby component can take over the function of more than one primary component when primary components fail. And we assume that the system has multi-state according to the states of components while all components have two states. This system is called as the multi-state redundant system with a multi-functional standby component. This type of redundant structure is frequently adapted by the system such as an aircraft in which the weight is an important design factor. In this paper, we propose new reliability model for this multi-state redundant system with a multi-functional standby component in order for evaluating the reliability of the system. Under the assumption that all components have constant failure rate, we evaluate the reliability of the system by applying Markov analysis method. And we investigate the effect of the multi-functional standby component by comparing reliabilities of the parallel system with multi-functional standby component and a simple parallel system and a parallel system with redundant structure.

• International Journal of Reliability and Applications
• /
• v.3 no.3
• /
• pp.147-154
• /
• 2002

In this paper, we consider the warm standby redundant system(WSRS) which is consisted of an active unit, a standby unit and a switchover device. In addition, the switchover processing is controlled by a control module. The effect of failure of the control module is taken into account to develop our reliability model for the redundant structure. For the performance evaluation of a redundant system with the function of switchover processing which is assumed to cause the increase of the failure rate of the system, some reliability indices, such as availability, average availability, reliability and steady state availability, are considered.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.267-270
• /
• 2000

In this paper, we consider the simple redundant structures with the function of hardware based active/standby control. The system includes two switch modules. The switch module is connected to a data bus, but only the active switch module has control of the data bus. The standby unit takes over the function of the active unit when the active unit failure or mode command are asserted. And this paper illustrate the high-speed router system and the overall redundant system architecture. The proposed redundant architecture for 80G Router system is verified and implemented with experiment.

• Journal of applied mathematics & informatics
• /
• v.5 no.1
• /
• pp.41-50
• /
• 1998

There are various notions of partial ordering between life-times of systems; stochastic ordering failure rate ordering and likeli-hood ration ordering. In this paper we show that for series systems with non i.i.d. exponential lifetimes of components standby redundancy at component level is better than that at system level in failure rate or-dering and likelihood ratio ordering. We also demonstrate that for 2-component parallel systems with i.i.d. exponential lifetimes of com-ponents standby system redundancy is better than standby component redundancy in failure rate ordering and likelihood ratio ordering.

• International Journal of Reliability and Applications
• /
• v.2 no.2
• /
• pp.107-115
• /
• 2001

This paper considers some reliability indices, such as availability, average availability, reliability and steady state availability, of a redundant system with the function of switchover processing. We also derive the confidence limits for steady state availability of such system. The system, which is considered in this paper, consists of an active unit, a standby unit and a switchover device. In addition, the switchover processing is controlled by a control module. The effect of failure of the control module is taken into account to develop our reliability model for the redundant structure. Numerical examples are presented to illustrate our results.

• Journal of the Korean Society for Railway
• /
• v.20 no.3
• /
• pp.349-355
• /
• 2017

Failures of railway systems can result in train delays or accidents, and therefore high reliability is required to ensure safety of railway systems. To improve reliability, railway systems are designed with redundant systems so that the standby system will continue to function normally even if the primary system fails. Generally, overall system reliability can be evaluated by the reliabilities of the parts of the whole system and the reliability of the redundant system considering common failures in case of each system is not conform physical, functional and process independent. In this study, the reliability of the hot-standby sparing system is analyzed the independent systems and dependent systems with common failures. The reliability for the standby system can be effectively analysed using Markov models, which can model the redundant configuration and the state transition.

• Journal of Korean Society for Quality Management
• /
• v.10 no.1
• /
• pp.13-15
• /
• 1982

A device is said to have three states if it has one good state and two mutually exclusive failure modes ; e. g., in one failure mode, it operates when it should not, in the other it doesn't operate when it Should. Some examples of such device include a fluid flow valve, an automatic machine, and an explosive. A Markov model is developed to obtain the availability Function of a 2-unit standby redundant system of such devices.

• Journal of Ocean Engineering and Technology
• /
• v.29 no.5
• /
• pp.380-385
• /
• 2015

In the development of an underwater construction robot, the reliability of the operating system is the most important issue because of its huge maintenance cost, especially in a deep sea application. In this paper, we propose a new redundant architectural design for the hydraulic control system of an underwater construction robot. The proposed architecture consists of dual independent modular redundancy management systems linked with a commercial profibus network. A cold standby redundancy management system consisting of a preprocessing switch circuit is applied to the signal network, and a hot standby redundancy management system is adapted to utilize two main controllers.

• Journal of Power Electronics
• /
• v.16 no.4
• /
• pp.1426-1437
• /
• 2016

In different industrial and mission oriented applications, redundant or standby semiconductor systems can be implemented to improve the reliability of power electronics equipment. The proper structure for implementation can be one of the redundant or standby structures for series or parallel switches. This selection is determined according to the type and failure rate of the fault. In this paper, the reliability and the mean time to failure (MTTF) for each of the series and parallel configurations in two redundant and standby structures of semiconductor switches have been studied based on different failure rates. The Markov model is used for reliability and MTTF equation acquisitions. According to the different values for the reliability of the series and parallel structures during SC and OC faults, a comprehensive comparison between each of the series and parallel structures for different failure rates will be made. According to the type of fault and the structure of the switches, the reliability of the switches in the redundant structure is higher than that in the other structures. Furthermore, the performance of the proposed series and parallel structures of switches during SC and OC faults, results in an improvement in the reliability of the boost dc/dc converter. These studies aid in choosing a configuration to improve the reliability of power electronics equipment depending on the specifications of the implemented devices.