BACKGROUND Almost no research has examined the impact of explanatory style on social adjustment. We hypothesised that adolescents with a pessimistic style would be less likely to develop and maintain social support networks. METHODS Seven hundred and nineteen students (351 males and 366 females; 2 unknown; M(AGE) = 12.28, SD = .49) completed an anonymous survey in Grades 7 through 10. Explana...

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.

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.

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.