We consider pessimistic bilevel stochastic programs in which the follower maximizes over a fixed compact convex set strictly quadratic function, whose Hessian depends on leader's decision. The resulting random variable is evaluated by risk measure. Under assumptions including real analyticity of lower-level goal we prove existence optimal solutions. discuss an alternate model where leader hedge...

This paper presents the pessimistic time complexity analysis of the parallel algorithm for minimizing the fleet size in the pickup and delivery problem with time windows. We show how to estimate the pessimistic complexity step by step—this approach can be easily adopted to other parallel algorithms for solving complex transportation problems.

In traditional data envelopment analysis (DEA) the uncertainty of inputs and outputs is not considered when evaluating the performance of a unit. In other words, effects of uncertainty on optimality and feasibility of models are ignored. This paper introduces a new model for measuring the efficiency of decision making units (DMUs) having interval inputs and outputs. The proposed model is based ...

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.

The Kepler planet sample can only be used to reconstruct the underlying planet occurrence rate if the detection efficiency of the Kepler pipeline is known; here we present the results of a second experiment aimed at characterising this detection efficiency. We inject simulated transiting planet signals into the pixel data of ∼10,000 targets, spanning one year of observations, and process the pi...

Fault-tolerance techniques based on checkpointing and message logging have been increasingly used in real-world applications to reduce service down-time. Most industrial applications have chosen pessimistic logging because it allows fast and localized recovery. The price that they must pay, however, is the high failure-free overhead. In this paper, we introduce the concept of K-optimistic loggi...

In this paper we consider real-time concurrency control for the nested transaction model. We analyze problems that have pure optimistic and pessimistic approaches. As the solution we propose a hybrid concurrency control algorithm which acts as an optimistic for transactions from different transaction trees and as pessimistic inside a single transaction tree.