30,234 research outputs found
Redundancy and Aging of Efficient Multidimensional MDS-Parity Protected Distributed Storage Systems
The effect of redundancy on the aging of an efficient Maximum Distance
Separable (MDS) parity--protected distributed storage system that consists of
multidimensional arrays of storage units is explored. In light of the
experimental evidences and survey data, this paper develops generalized
expressions for the reliability of array storage systems based on more
realistic time to failure distributions such as Weibull. For instance, a
distributed disk array system is considered in which the array components are
disseminated across the network and are subject to independent failure rates.
Based on such, generalized closed form hazard rate expressions are derived.
These expressions are extended to estimate the asymptotical reliability
behavior of large scale storage networks equipped with MDS parity-based
protection. Unlike previous studies, a generic hazard rate function is assumed,
a generic MDS code for parity generation is used, and an evaluation of the
implications of adjustable redundancy level for an efficient distributed
storage system is presented. Results of this study are applicable to any
erasure correction code as long as it is accompanied with a suitable structure
and an appropriate encoding/decoding algorithm such that the MDS property is
maintained.Comment: 11 pages, 6 figures, Accepted for publication in IEEE Transactions on
Device and Materials Reliability (TDMR), Nov. 201
Probabilistic Analysis of LCF Crack Initiation Life of a Turbine Blade under Thermomechanical Loading
An accurate assessment for fatigue damage as a function of activation and
deactivation cycles is vital for the design of many engineering parts. In this
paper we extend the probabilistic and local approach to this problem proposed
in [1,2] and [3] to the case of non-constant temperature fields and
thermomechanical loading. The method has been implemented as a finite element
postprocessor and applied to an example case of a gas-turbine blade which is
made of a conventionally cast nickel base superalloy.Comment: 8 pages, 3 figure
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