1,333 research outputs found
A Hybrid Approach with Multi-channel I-Vectors and Convolutional Neural Networks for Acoustic Scene Classification
In Acoustic Scene Classification (ASC) two major approaches have been
followed . While one utilizes engineered features such as
mel-frequency-cepstral-coefficients (MFCCs), the other uses learned features
that are the outcome of an optimization algorithm. I-vectors are the result of
a modeling technique that usually takes engineered features as input. It has
been shown that standard MFCCs extracted from monaural audio signals lead to
i-vectors that exhibit poor performance, especially on indoor acoustic scenes.
At the same time, Convolutional Neural Networks (CNNs) are well known for their
ability to learn features by optimizing their filters. They have been applied
on ASC and have shown promising results. In this paper, we first propose a
novel multi-channel i-vector extraction and scoring scheme for ASC, improving
their performance on indoor and outdoor scenes. Second, we propose a CNN
architecture that achieves promising ASC results. Further, we show that
i-vectors and CNNs capture complementary information from acoustic scenes.
Finally, we propose a hybrid system for ASC using multi-channel i-vectors and
CNNs by utilizing a score fusion technique. Using our method, we participated
in the ASC task of the DCASE-2016 challenge. Our hybrid approach achieved 1 st
rank among 49 submissions, substantially improving the previous state of the
art
Object detection via a multi-region & semantic segmentation-aware CNN model
We propose an object detection system that relies on a multi-region deep
convolutional neural network (CNN) that also encodes semantic
segmentation-aware features. The resulting CNN-based representation aims at
capturing a diverse set of discriminative appearance factors and exhibits
localization sensitivity that is essential for accurate object localization. We
exploit the above properties of our recognition module by integrating it on an
iterative localization mechanism that alternates between scoring a box proposal
and refining its location with a deep CNN regression model. Thanks to the
efficient use of our modules, we detect objects with very high localization
accuracy. On the detection challenges of PASCAL VOC2007 and PASCAL VOC2012 we
achieve mAP of 78.2% and 73.9% correspondingly, surpassing any other published
work by a significant margin.Comment: Extended technical report -- short version to appear at ICCV 201
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