In this article, we survey the developments with respect to generalized models of repairable systems during the 1990s, particularly for the last five years. In this field, we notice the sharp fundamental problem that voluminous and complicated models are proposed without sufficient evidence (or data) for justifying a success in tackling real engineering problems. Instead of following the myth o...

Reversibility is a key to efficient and maintainable NLG systems. In this paper, we present a formal definition of reversible NLG systems and develop a classification of existing natural language dialog systems in this framework.

A complex repairable system generally adopts multi-grade preventive maintenance. The optimization of maintenance decision making is usually regarded as a complex mathematical problem. This study proposes a three-grade preventive maintenance optimization method for complex repairable system based on field failure data. Specifically, all failures are classified into three categories: minor, moder...

In this paper, we present an optimal burn-in model for repairable assembly products (RAP) sold under warranty. The general repairable products, sold under warranty and optimal burn-in model by Sheu (2004) are further extended to the case in which the probability of type II failure is independent for a parent item. This paper investigates a parent item (product or system) made up of two items (s...

In this research, we study an optimal overhaul–replacement policy of a multi-degraded repairable system sold with a free replacement warranty. In the proposed replacement policy, a maintenance action and failure are dependent on a system degradation level and the system age, and hence the replacement model will provide more effective maintenance decisions. Failure of the system is modeled using...

A non-empty set F of n-bit vectors over alphabet {0, 1} is called singly repairable, if every vector u ∈ F satisfies the following conditions: (i) if any bit of u is changed (from 0 to 1 or vice versa), the new vector does not belong to F (ii) there is a unique choice of a different bit that can then be changed to give another vector 6= u in F . Such families F exist only for even n and we show...

In this work, we give locally repairable regenerating code (LRRC) [1]–[4] constructions that can protect the file size promised by the graph analysis of the modified family helper selection (MFHS) scheme [1] at the minimum-bandwidthregenerating (MBR) point. I. RANDOM LINEAR CODE CONSTRUCTION FOR A CLASS OF (n, k, d, r) PARAMETERS In this section, we prove the existence and construction of linea...