Long-life space cryocooler applications, such as NASA's Atmospheric Infrared Sounder (AIRS) instrument, require that the cryocooler system possess a very high level of reliability. This need for high reliability not only demands that high reliability coolers be used, but often requires that some form of redundancy be incorporated. One common implementation is standby redundancy; however, active...

This paper presents a new mathematical model for a redundancyallocation problem (RAP) withcold-standby redundancy strategy and multiple component choices.The applications of the proposed model arecommon in electrical power, transformation,telecommunication systems,etc.Manystudies have concentrated onone type of time-to-failure, butin thispaper, two components of time-to-failures which follow hy...

Uncertain variable is defined as a measurable function from an uncertainty space to the set of real numbers for describing subjective uncertain phenomena, which is employed to characterize the element, component and system lifetimes in this paper. Within the framework of uncertainty theory, reliability measure and percentile lifetime are defined to measure the system reliability in this paper. ...

In this paper, we analyze spare parts supply for a system with a “k-outof-N” redundancy structure for key components, different standby policies (cold, warm and hot standby redundancy) and local spare parts inventories for sub-components. We assume multiple part types (sub-components) that fail randomly with exponentially distributed interfailure times. Due to the standby policies and the limit...

The combination of N-modular redundancy (NMR) and standby sparing has resulted in a promising redundancy technique for protecting those portions of a fault-tolerant system whose continuous real-time operation is essential. This technique, known as hybrid redundancy, uses N + Sp identical modules. N of these are connected to a majority voter to form an NMR core. The remaining Sp are used as stan...

This paper proposes a new fuzzy assessing procedure with application in management decision making. The proposed fuzzy approach build the membership functions for system characteristics of a standby repairable system. This method is used to extract a family of conventional crisp intervals from the fuzzy repairable system for the desired system characteristics. This can be determined with a set ...

To increase the reliability of a specific system, using redundant components is a common method which is called redundancy allocation problem (RAP). Some of the RAP studies have focused on k-out-of-n systems. However, all of these studies assumed predetermined active or standby strategies for each subsystem. In this paper, for the first time, we propose a k-out-of-<em...

In this research, a new hybrid model for the redundancy allocation problem (RAP) in series-parallel configuration with k-out-of-n subsystem is presented. given model, policy set to an active, warm standby, or no redundancy. standby policy, imperfect switch detected component's failure and replaced fail component one. So, subsystems' one of model's decision variables. We presented objective func...

In this paper we present SCMS-ER: Small Cell Management System Emergency Recovery. SCMS-ER provides a way of backing up Small Cell Management System critical data across two geographic locations. It also provides a plan for replication of backup data so that the client data is recoverable in the event of a disaster on the main site. Keywords—small cell, Femto cell, redundancy, geographic redund...

A marriage of N-modular redundancy (NMR) and standby sparing has resulted in a promising redundancy technique for protecting those portions of a fault-tolerant system whose continuous real-time operation is essential. This technique, known as hybrid redundancy, consists of N identical modules connected to a majority voter to form an NMR core. Disagreement detectors instruct a switch to replace ...