GPU-accelerated tree-based exact optimization methods

2013 ◽  
pp. 175-204
Author(s):  
������� ◽  
Igor Tsarkov

The project duration reduction problem in the conditions of limited renewable resources is one of the most popular themes within researches in area of project management�s mathematical models during more than 50 years. Nowadays applying of exact optimization methods in real practice is impossible, so heuristic methods are used in this problem resolution. Among a set of heuristic methods there is a considerable share of so-called multipass scheduling methods based on consecutive application of different heuristic rules of resource conflicts resolution to the same project. If at this each new schedule turns out with use of random numbers, they speak about sampling. In this paper a review of existing sampling methods will be made, and their efficiency research on the basis of PSPLIB projects will be conducted. Besides, has been received a confirmation that at a large number of iterations in a sampling method the parallel schemes surpass consecutive ones, and a new method of sampling combining various schemes and rules of priority has been constructed.


Author(s):  
Stephan Scheuerer

Decision support systems (DSSs) provide modern solution techniques that help the decision maker to find the best solution to a problem. These embedded solution techniques include and combine, but are not limited to, simulation, exact optimization methods, and heuristics. Especially in the field of heuristics, recent advances in metaheuristic methods have proved to be remarkably effective so that metaheuristics are nowadays the preferred way for solving many types of complex problems, particularly those of combinatorial nature. Some of these problems are, for example, the well-known “traveling salesman” problem, the generalized assignment problem, the set-covering problem, and vehicle and network routing applications. Most of all, metaheuristics allow us to solve real-world problems with a notably high level of complexity. This is where exact methods are often incapable of finding solutions whose qualities are close to that obtained by the leading metaheuristics. Metaheuristic applications with world-class performance can be found in all kinds of areas such as economics, engineering, and natural sciences.


2018 ◽  
Author(s):  
Gérard Cornuéjols ◽  
Javier Peña ◽  
Reha Tütüncü
Keyword(s):  

Author(s):  
Gerard Cornuejols ◽  
Reha Tutuncu
Keyword(s):  

TAPPI Journal ◽  
2013 ◽  
Vol 12 (4) ◽  
pp. 19-27
Author(s):  
PATRICK HUBER ◽  
LAURENT LYANNAZ ◽  
BRUNO CARRÉ

The fraction of deinked pulp for coated paper production is continually increasing, with some mills using 100% deinked pulp for the base paper. The brightness of the coated paper made from deinked pulp may be reached through a combination of more or less extensive deinking, compensated by appropriate coating, to optimize costs overall. The authors proposed general optimization methods combined with Kubelka-Munk multilayer calculations to find the most economical combination of deinking and coating process that would produce a coated paper made from DIP, at a given target brightness, while maintaining mechanical properties.


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