Abstract

Abstract

Abstract
This paper describes a new heuristic for the nesting problem based on a 2-exchange neighbourhood generation strategy. This mechanism guides the search through the solution space consisting of the sequences of pieces and relies on a low-level placement heuristic to actually convert one sequence in a feasible layout. The placement heuristic is based on a bottom-left greedy procedure with the ability to fill holes in the middle of the layout at a later stage. Several variants of the 2-exchange nesting heuristic were implemented and tested with different initial solution ranking criteria, different strategies for selecting the next solution, and different neighbourhood sizes. The computational experiments were based on data sets published in the literature. In most of the cases, the 2-exchange nesting algorithm generated better solutions than the best known solutions.

Abstract
This paper presents the most innovative aspects of a middleware architecture that enables the provision of advanced personalized services in a Virtual Home Environment context. Multimedia considerations to extend the architecture to support mobile multimedia in a ubiquitous access terminal and network environment are also included.

Abstract
This study introduces a technique for the design of multivariable decentralized proportional-integral controllers (Pl). This problem is addressed by first analyzing the pairing possibilities of the manipulated and controlled variables, which result in minor interaction between the loops; controller tuning is then performed by using the particle swarm optimization algorithm. The control objective is to design the multivariable controller for the several viable pairing possibilities, minimizing the error between the controller outputs and the set-point variables. Simulation results presented allow the conclusion that the proposed technique can tune the controller with all the loops closed, reducing the interaction effect. It is also shown that for this problem the particle swarm algorithm is faster in converging than a genetic algorithm.

Abstract
In VESPER1, the concept of VHE is being implemented and validated through the provision of a VHE system and various services to make use of it. This paper describes one of these services and presents how it validates VHE architecture aspects related with service adaptation to terminals and network, connection establishment, service personalization, session continuity/mobility and service advertisement. The paper also discusses some VHE usage scenarios of the resource discovery feature, showing how it plays an important role particularly in what concerns the ubiquitous service availability through the VHE platform.