1997
Authors
Correia, ME; Silva, F; Costa, VS;
Publication
LOGIC PROGRAMMING - PROCEEDINGS OF THE 1997 INTERNATIONAL SYMPOSIUM
Abstract
One of the advantages of logic programming in the fact that it offers many sources of implicit parallelism, such as and-parallelism and or-parallelism Recently, research has been concentrated on integrating the different forms of parallelism into a single combined system. In this work we concentrate on the problem of integrating or-parallelism and independent and-parallelism for parallel Prolog systems. We contend that previous data structures require pure recomputation and therefore do not allow for orthogonality between and parallelism and or-parallelism. In contrast, we submit that a simpler solution, the sparse binding array, does guarantee this goal, and explain in detail how independent and-parallelism and or-parallelism can thus be efficiently combined.
2004
Authors
Lopes, R; Costa, VS; Silva, F;
Publication
Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Networks
Abstract
Logic programming provides a high-level view of programming that gives implementor; a vast latitude in what techniques to research towards obtaining the best performance for logic programs. The Emended Andorra Model was designed towards achieving reduction of the search space whilst exploiting all the available parallelism in the application. The BEAM is a first sequential implementation for the Extended Andorra Model with Implicit Control, that has been shown to obtain good results. In this work we propose the RAINBOW, a parallel execution model for the BEAM. We present a general overview of how to distribute work, propose alternative approaches towards addressing the binding problem for the EAM, and present a scheduling strategy.
2012
Authors
Ferreira, CA; Gama, J; Costa, VS;
Publication
COMPUTER AND INFORMATION SCIENCES II
Abstract
In this work we present XmuSer, a multi-relational framework suitable to explore temporal patterns available in multi-relational databases. xMuS er's main idea consists of exploiting frequent sequence mining, using an efficient and direct method to learn temporal patterns in the form of sequences. Grounded on a coding methodology and on the efficiency of sequence miners, we find the most interesting sequential patterns available and then map these findings into a new table, which encodes the multi-relational timed data using sequential patterns. In the last step of our framework, we use an ILP algorithm to learn a theory on the enlarged relational database that consists on the original multi-relational database and the new sequence relation. We evaluate our framework by addressing three classification problems.
2011
Authors
Ferreira, CA; Gama, J; Costa, VS;
Publication
PROGRESS IN ARTIFICIAL INTELLIGENCE
Abstract
In this work we present XMuSer, a multi-relational framework suitable to explore temporal patterns available in multi-relational databases. XMuSer's main idea consists of exploiting frequent sequence mining, using an efficient and direct method to learn temporal patterns in the form of sequences. Grounded on a coding methodology and on the efficiency of sequential miners, we find the most interesting sequential patterns available and then map these findings into a new table, which encodes the multi-relational timed data using sequential patterns. In the last step of our framework, we use an ILP algorithm to learn a theory on the enlarged relational database that consists on the original multi-relational database and the new sequence relation. We evaluate our framework by addressing three classification problems. Moreover, we map each one of three different types of sequential patterns: frequent sequences, closed sequences or maximal sequences.
2008
Authors
Ferreira, CA; Gama, J; Costa, VS;
Publication
20TH IEEE INTERNATIONAL CONFERENCE ON TOOLS WITH ARTIFICIAL INTELLIGENCE, VOL 1, PROCEEDINGS
Abstract
One of the major challenges in knowledge discovery is how to extract meaningful and useful knowledge from the complex structured data that one finds in Scientific and Technological applications. One approach is to explore the logic relations in the database and using, say, an Inductive Logic Programming (ILP) algorithm find descriptive and expressive patterns. These patterns can then be used as features to characterize the target concept, The effectiveness of these algorithms depends both upon the algorithm we use to generate the patterns and upon the classifier Rule mining provides an excellent framework for efficiently mining the interesting patterns that are relevant. We propose a novel method to select discriminative patterns and evaluate the effectiveness of this method on a complex discovery application of practical interest.
2012
Authors
Ferreira, CA; Gama, J; Santos Costa, V;
Publication
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Abstract
This work presents an optimized version of XMuSer, an ILP based framework suitable to explore temporal patterns available in multi-relational databases. XMuSer's main idea consists of exploiting frequent sequence mining, an efficient method to learn temporal patterns in the form of sequences. XMuSer framework efficiency is grounded on a new coding methodology for temporal data and on the use of a predictive sequence miner. The frameworks selects and map the most interesting sequential patterns into a new table, the sequence relation. In the last step of our framework, we use an ILP algorithm to learn a classification theory on the enlarged relational database that consists of the original multi-relational database and the new sequence relation. We evaluate our framework by addressing three classification problems and map each one of three different types of sequential patterns: frequent, closed or maximal. The experiments show that our ILP based framework gains both from the descriptive power of the ILP algorithms and the efficiency of the sequential miners. © 2012 Springer-Verlag Berlin Heidelberg.
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