In this paper two new heuristics, named Min–min-C and Max–min-C, are proposed able to provide nearoptimal solutions to themapping of parallel applications, modeled as Task Interaction Graphs, on computational clouds. The aim of these heuristics is to determine mapping solutions which allow exploiting at best the available cloud resources to execute such applications concurrentlywith the other c...

Hayakawa (1990) has very recently studied the behavior of the power for several large sample tests for the mean direction vector of the Langevin distribution. These tests are not known to possess any non-trivial optimal property. Here we derive some multiparameter locally optimal tests, e.g., best first and second directional derivative tests and locally most mean powerful tests. For the case w...

We analyze two and three-dimensional variants of Hotelling’s model of differentiated products. In our setup, consumers can place different importance on each product attribute; this is measured by a weight in the disutility of distance in each dimension. Two firms play a two-stage game; they choose locations in stage 1 and prices in stage 2. We seek subgame-perfect equilibria. We find that all ...

Classical Fault Tree Analysis (FTA) can determine the effects of combinations of failure events on a system but cannot capture the potentially critical significance of the temporal ordering of events. In this paper, we propose a temporal extension based on the use of Priority-AND gates to allow relative temporal ordering and temporal analysis in FTA. The classical notion of minimal cut-sets is ...

Luca Trevisan [1] presented an approximation algorithm for Max Cut based on spectral partitioning techniques. He proved that the algorithm has an approximation ratio of at least 0.531. We improve this bound up to 0.6142. We also define and extend this result for the more general Maximum Colored Cut problem.

Minimal Cut Vectors (MCVs) and Minimal Path Vectors (MPVs) are one of the principal tools of reliability engineering. MCVs represent situations in which repair/improvement of any system component results in functioning/ improvement of the system. MPVs coincide with circumstances under which failure/degradation of any system component causes system failure/degradation. MCVs and MPVs allow us to ...

Min-max and min-max regret criteria are commonly used to define robust solutions. After motivating the use of these criteria, we present general results. Then, we survey complexity results for the min-max and min-max regret versions of some combinatorial optimization problems: shortest path, spanning tree, assignment, cut, s-t cut, knapsack. Since most of these problems are NP-hard, we also inv...

We are concerned with the control of quality of service (QoS) in wireless cellular networks utilizing linear receivers. We investigate the issues of fairness and total performance, which are measured by a utility function in the form of a weighted sum of link QoS. We disprove the common conjecture on incompatibility of min-max fairness and utility optimality by characterizing network classes in...

This paper investigates, for the first time in the literature, the approximation of minmax (regret) versions of classical problems like shortest path, minimum spanning tree, and knapsack. For a constant number of scenarios, we establish fully polynomial-time approximation schemes for the min-max versions of these problems, using relationships between multi-objective and min-max optimization. Us...