Optimal reliability improvement for used items sold with warranty

The market for used products is becoming more competitive and dealers of used products use warranty to promote sales as well as to provide assurnace to customers. Offering warranty results in additional costs associated with warranty servicing. This cost can be reduced through actions such as overhaul and upgrade that improves the reliability of the item. This is worthwhile only if the cost of improvement is less than the reduction in the warranty servicing cost. This paper deals with two models to decide on the reliability improvement strategies for used items sold with FRW policy.

Which version of the Eysenck Personality Profiler is best? 6-, 12- or 20-items per scale

Data provided by 400 first year undergraduate students were analysed to develop two short forms of the Eysenck Personality Profiler (EPP) in which each of the 22 primary scales is assessed by a 6-item and a 12-item version instead of the usual 20-item per scale measure. In comparison with the 6-item per scale measure, the 12-item version retains more of the characteristics of the long version and seems a good compromise between quality of data and administration time. (C) 2004 Elsevier Ltd. All rights reserved.

A new repair-replace strategy for items sold with a two-dimensional warranty

For repairable items, the manufacturer has the option to either repair or replace a failed item that is returned under warranty. In this paper, we look at a new warranty servicing strategy for items sold with two-dimensional warranty where the failed item is replaced by a new one when it fails for the first time in a specified region of the warranty and all other failures are repaired minimally. The region is characterised by two parameters and we derive the optimal values for these to minimise the total expected warranty servicing cost. We compare the results with other repair-replace strategies reported in the literature. (C) 2003 Elsevier Ltd. All rights reserved.

Filtering duplicate items over distributed data streams

In recent years many real time applications need to handle data streams. We consider the distributed environments in which remote data sources keep on collecting data from real world or from other data sources, and continuously push the data to a central stream processor. In these kinds of environments, significant communication is induced by the transmitting of rapid, high-volume and time-varying data streams. At the same time, the computing overhead at the central processor is also incurred. In this paper, we develop a novel filter approach, called DTFilter approach, for evaluating the windowed distinct queries in such a distributed system. DTFilter approach is based on the searching algorithm using a data structure of two height-balanced trees, and it avoids transmitting duplicate items in data streams, thus lots of network resources are saved. In addition, theoretical analysis of the time spent in performing the search, and of the amount of memory needed is provided. Extensive experiments also show that DTFilter approach owns high performance.