Abstract
Several classification problems involve more than two classes. These problems are known as multiclass classification problems. One of the approaches to deal with multiclass problems is their decomposition into a set of binary problems. Recent work shows important advantages related with this approach. Several strategies have been proposed for this decomposition. The strategies most frequently used are All-vs-All, One-vs-All and Error Correction Output Codes (ECOC). ECOCs are based on binary words (codewords) and have been adapted to deal with multiclass problems. For such, they must comply with a number of specific constraints. Different dimensions may be adopted for the codewords for each number of classes in the problem. These dimensions grow exponentially with the number of classes present in a dataset. Two methods to choose the dimension of a ECOC, which assure a good trade-off between redundancy and error correction capacity, are proposed in this paper. The proposed methods are evaluated in a set of benchmark classification problems. Experimental results show that they are competitive with other multiclass decomposition methods.

Abstract
In general, distributed generation is not subject to a centralized dispatch and reactive power generation is usually restricted by operation rules defined by the distribution system operators. With the growth of distributed generation and microgrids in distribution networks, the development of voltage control functionalities for these units needs to be investigated. This requires a new operation philosophy to exploit reactive power generation capability of distributed generation and microgeneration with the objective of optimizing network operation: minimize active power losses and maintain voltage profiles within adequate margins. This implies that distributed generation should adjust their reactive power generation, i.e. supply an ancillary service of voltage and reactive power control. In addition to the growth in distributed generation penetration, microgeneration is expected to develop considerably and contribute to the implementation of efficient voltage control schemes. For this new scenario, a hierarchical voltage control scheme must be implemented, using communication and control possibilities that will be made available for microgrid operation. Technical advantages and feasibility of this operation philosophy are investigated in this chapter by analyzing the impact of the proposed control procedures on distribution networks. In addition, the identification of control action needs is assessed by solving an optimization problem, where voltage profiles are improved and active power losses minimized, subject to a set of technical constraints. The solution for this problem is obtained using an Evolutionary Particle Swarm Optimization algorithm. The control algorithm implemented will enable dealing even with extreme situations, where reactive power control is not sufficient to maintain system operation and therefore generation shedding actions must be performed.

Abstract

Abstract
This paper addresses the problem of scheduling multi-user jobs on clusters, both homogeneous and heterogeneous. A user job is composed by a set of dependent tasks and it is described by a direct acyclic graph (DAG). The aim is to maximize the resource usage by allowing a floating mapping of processors to a given job, instead of the common mapping approach that assigns a fixed set of processors to a user for a period of time. The simulation results show a better cluster usage. The scheduling algorithm minimizes the total length of the schedule (makespan) of a given set of parallel jobs, whose priorities are represented in a DAG. The algorithm is presented as producing static schedules although it can be adapted to a dynamic behavior as discussed in the paper.

Abstract

Abstract
The OSGi platform embodies the desirable concepts of modularity and dynamic components to build a Service Oriented Platform, whose components interact by means of well defined contracts. Despite being service oriented, it lacks mechanisms to differentiate service's customers from each other and, therefore, it fails to provide different Service Level Agreements. In this paper we start by isolating customers from each other and at a later stage provide mechanisms to offer adequate SLAs. As each client is isolated in a self-contained environment we are able to decouple them from the platform (and from the underlying node) to offer mobility among nodes. The advantages of this approach are two-fold: 1) ability to cope with node failures by migrating customers to healthy nodes and 2) optimization of global resource resource usage and further enforcement of SLA by migrating customers to nodes with adequate resources available. Copyright 2008 ACM.