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ParGRES is a middleware aimed to efficiently process heavy weight queries, typical of OLAP, on top of a database cluster. ParGRES achieves query processing speed-up through intra-and inter-query parallelism in a PC cluster environment with database replication and virtual partitioning. It accelerates both individual queries and system throughput. Our(More)
Organizations have to face new challenges, hold new opportunities, conquer and maintain important customers and get a better strategic position as faster as possible. The principles used in Autonomic Computing can be adapted to help them survive in this dynamic business scenario. Thus, organizations should count on processes that can be able to(More)
Nowadays, many authors suggest that business rules are a special class of information system requirements. Business rules should have a special handling, from the earliest analysis phases to the implementation. The related literature states many ways for business rule specification, among them, the UML Object Constraint Language (OCL). OCL is an adequate(More)
Many works have been proposed in order to improve the recommendation accuracy. Algorithms aiming to improve recommendation accuracy have been developed and evaluated. These algorithms usually work with training data sets which are learned and used to make predictions on users' tastes. The training data set choice is a difficult task not only due to the(More)
Neural networks is one of the techniques used for time series analysis. The performance of neural networks is affected by some parameters such as neural network structure and the quality of data preprocessing. These parameters need to be explored in order to obtain an optimal neural network. However, the manual establishment of different neural networks(More)
Traditional query processing provides exact answers to queries. However, in many applications, the response time of exact answers is often longer than what is acceptable. Approximate query processing has emerged as an alternative approach to give to the user an answer in a short time. The goal is to provide an estimated result in one order of magnitude less(More)