9,039 research outputs found
Oversampling for Imbalanced Learning Based on K-Means and SMOTE
Learning from class-imbalanced data continues to be a common and challenging
problem in supervised learning as standard classification algorithms are
designed to handle balanced class distributions. While different strategies
exist to tackle this problem, methods which generate artificial data to achieve
a balanced class distribution are more versatile than modifications to the
classification algorithm. Such techniques, called oversamplers, modify the
training data, allowing any classifier to be used with class-imbalanced
datasets. Many algorithms have been proposed for this task, but most are
complex and tend to generate unnecessary noise. This work presents a simple and
effective oversampling method based on k-means clustering and SMOTE
oversampling, which avoids the generation of noise and effectively overcomes
imbalances between and within classes. Empirical results of extensive
experiments with 71 datasets show that training data oversampled with the
proposed method improves classification results. Moreover, k-means SMOTE
consistently outperforms other popular oversampling methods. An implementation
is made available in the python programming language.Comment: 19 pages, 8 figure
Attribute Noise-Sensitivity Impact: Model Performance and Feature Ranking
Developing robust and less complex models capable of coping with environment volatility is the quest of every data mining project. This study attempts to establish heuristics for investigating the impact of noise in instance attributes data on learning model volatility. In addition, an alternative method for determining attribute importance and feature ranking, based on attribute sensitivity to noise is introduced. We present empirical analysis of the effect of attribute noise on model performance and how it impacts the overall learning process. Datasets drawn from different domains including Medicine, CRM, and security are employed by the study. Using proposed technique has practical implications by supporting building low volatile, high performance predictive models prior to production deployment. Also the study has implications for research by filling the gap in attribute noise research and its impact
Multi-Modal Multi-Scale Deep Learning for Large-Scale Image Annotation
Image annotation aims to annotate a given image with a variable number of
class labels corresponding to diverse visual concepts. In this paper, we
address two main issues in large-scale image annotation: 1) how to learn a rich
feature representation suitable for predicting a diverse set of visual concepts
ranging from object, scene to abstract concept; 2) how to annotate an image
with the optimal number of class labels. To address the first issue, we propose
a novel multi-scale deep model for extracting rich and discriminative features
capable of representing a wide range of visual concepts. Specifically, a novel
two-branch deep neural network architecture is proposed which comprises a very
deep main network branch and a companion feature fusion network branch designed
for fusing the multi-scale features computed from the main branch. The deep
model is also made multi-modal by taking noisy user-provided tags as model
input to complement the image input. For tackling the second issue, we
introduce a label quantity prediction auxiliary task to the main label
prediction task to explicitly estimate the optimal label number for a given
image. Extensive experiments are carried out on two large-scale image
annotation benchmark datasets and the results show that our method
significantly outperforms the state-of-the-art.Comment: Submited to IEEE TI
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