8,714 research outputs found
An Optimized Soft Computing Based Passage Retrieval System
In this paper we propose and evaluate a soft computing-based passage retrieval system for Question Answering Systems (QAS). Fuzzy PR, our base-line passage retrieval system, employs a similarity measure that attempts to model accurately the question reformulation intuition. The similarity measure includes fuzzy logic-based models that evaluate efficiently the proximity of question terms and detect term variations occurring within a passage. Our experimental results using FuzzyPR on the TREC and CLEF corpora show that our novel passage retrieval system achieves better performance compared to other similar systems. Finally, we describe the performance results of OptFuzzyPR, an optimized version of FuzzyPR, created by optimizing the values of FuzzyPR system parameters using genetic algorithms
Combined optimization of feature selection and algorithm parameters in machine learning of language
Comparative machine learning experiments have become an important methodology in empirical approaches to natural language processing (i) to investigate which machine learning algorithms have the 'right bias' to solve specific natural language processing tasks, and (ii) to investigate which sources of information add to accuracy in a learning approach. Using automatic word sense disambiguation as an example task, we show that with the methodology currently used in comparative machine learning experiments, the results may often not be reliable because of the role of and interaction between feature selection and algorithm parameter optimization. We propose genetic algorithms as a practical approach to achieve both higher accuracy within a single approach, and more reliable comparisons
Learning to Reason: End-to-End Module Networks for Visual Question Answering
Natural language questions are inherently compositional, and many are most
easily answered by reasoning about their decomposition into modular
sub-problems. For example, to answer "is there an equal number of balls and
boxes?" we can look for balls, look for boxes, count them, and compare the
results. The recently proposed Neural Module Network (NMN) architecture
implements this approach to question answering by parsing questions into
linguistic substructures and assembling question-specific deep networks from
smaller modules that each solve one subtask. However, existing NMN
implementations rely on brittle off-the-shelf parsers, and are restricted to
the module configurations proposed by these parsers rather than learning them
from data. In this paper, we propose End-to-End Module Networks (N2NMNs), which
learn to reason by directly predicting instance-specific network layouts
without the aid of a parser. Our model learns to generate network structures
(by imitating expert demonstrations) while simultaneously learning network
parameters (using the downstream task loss). Experimental results on the new
CLEVR dataset targeted at compositional question answering show that N2NMNs
achieve an error reduction of nearly 50% relative to state-of-the-art
attentional approaches, while discovering interpretable network architectures
specialized for each question
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