in this paper, the researchers have proposed a multi-dimensional knapsack model for project capital budgeting problem in uncertain situation which has been modeled through fuzzy sets. the optimistic and pessimistic situations were considered and associated deterministic models were yielded. numerical example has been supplied toillustrate the performance of proposed model. the results were prom...

In large scale distributed systems, replication is a popular technique for improving the accessibility of information and surviving the unreliability of communication networks. Pessimistic replication and optimistic replication are two contrasting replication models. They represent the two extremes in the availability-consistency. Pessimistic replication favors consistency over availability, wh...

Weather-related risks can substantially affect the crop volume depending on time and intensity of agricultural operations performed by the farmer. However, decisions under uncertainty are in some way also liable to another risk – that of excessively optimistic or pessimistic estimation of the decision maker. The paper presents results of optimistic and pessimistic farmer’s agricultural operatio...

in recent decades, using water resources is increased for the sake of industrial, domestic and agricultural water consumptions by increase in urbanization and industrial development in karaj region that fraction of groundwater resources is too much according to the recent drought years and reduced precipitation in middle-east. these outcomes has caused groundwater level drop, reduced in aquifer...

This paper introduces a new robust data envelopment analysis (RDEA) approach for analyzing and ranking the organizations’ operations strategies. In the proposed RDEA method, pessimistic and optimistic efficiencies of decision making units (DMUs) obtained from the robust counterpart of the envelopment form and the optimistic counterpart of the multiplier form of DEA are introduced. The inputs an...

We consider the extension of non-monotonic preference logic with the distinction between controllable (or endogenous) and uncontrollable (or exogenous) variables, which can be used for example in agent decision making and deliberation. We assume that the agent is optimistic about its own controllables and pessimistic about its uncontrollables, and we study ways to merge these two distinct dimen...

Optimistic concurrency control relies on end-of-transaction validation rather than lock acquisition prior to data accesses. Optimistic concurrency control is popular and various systems employ it based on a conviction that it increases concurrency, performance, and scalability. In contrast, we have concluded that optimistic concurrency control permits more concurrency than pessimistic concurren...

Message logging protocols are an integral part of a technique for implementing processes that can recover from crash failures. All message logging protocols require that, when recovery is complete, there be no orphan processes, which are surviving processes whose states are inconsistent with the recovered state of a crashed process. We give a precise speciication of the consistency property \no...

Message-logging protocols are an integral part of a popular technique for implementing processes that can recover from crash failures. All message-logging protocols require that, when recovery is complete, there be no orphan processes , which are surviving processes whose states are inconsistent with the recovered state of a crashed process. We give a precise speci cation of the consistency pro...

There are two types of critical values for birandom variable: the optimistic and pessimistic values. In this paper, some theoretical aspects of optimistic and pessimistic values of birandom variable are investigated. Based on the results, some properties of birandom chance-constrained programming models can be further discussed.