Feature Level Ensemble Method for Classifying Multi-Media Data

Multimedia data consists of several different types of data, such as numbers, text, images, audio etc. and they usually need to be fused or integrated before analysis. This study investigates a feature-level aggregation approach to combine multimedia datasets for building heterogeneous ensembles for classification. It firstly aggregates multimedia datasets at feature level to form a normalised big dataset, then uses some parts of it to generate classifiers with different learning algorithms. Finally, it applies three rules to select appropriate classifiers based on their accuracy and/or diversity to build heterogeneous ensembles. The method is tested on a multimedia dataset and the results show that the heterogeneous ensembles outperform the individual classifiers as well as homogeneous ensembles. However, it should be noted that, it is possible in some cases that the combined dataset does not produce better results than using single media data

Machine Learning Ensemble Methods for Classifying Multi-media Data

Multimedia data have, over recent years, been produced in many fields. They have important applications for such diverse areas as social media and healthcare, due to their capacity to capture rich information. However, their unstructured and separated nature gives rise to various problems. In particular, fusing and integrating multi-media datasets and finding effective ways to learn from them have proven to be major challenges for machine learning. In this thesis we investigated the development of the ensemble methods for classifying multi-media data in two key aspects: data fusion and model selection. For the data fusion, we devised two different strategies. The first one is the Feature Level Ensemble Method (FLEM) that aggregates all the features into a single dataset and then generates the models to build ensembles using this dataset. The second one is the Decision Level Ensemble Method (DLEM) that generates the models from each sub dataset individually and then aggregates their outputs with a decision fusion function. For the model selection we derived four different model selection rules. The first rule, R0, uses just the accuracy to select models. The rules R1 and R2 use firstly accuracy and then diversity to select models. In R3, we defined a generalised function that combines the accuracy and diversity with different weights to select models to build an ensemble. Our methods were compared with existing well known ensemble methods using the same dataset and another dataset that became available after our methods had been developed. The results were critically analysed and the statistical significance analyses of the results show that our methods had better performance in general and the generalised R3 is the most effective rule in building ensembles

Generalised Decision Level Ensemble Method for Classifying Multi-media Data

In recent decades, multimedia data have been commonly generated and used in various domains, such as in healthcare and social media due to their ability of capturing rich information. But as they are unstructured and separated, how to fuse and integrate multimedia datasets and then learn from them eectively have been a main challenge to machine learning. We present a novel generalised decision level ensemble method (GDLEM) that combines the multimedia datasets at decision level. After extracting features from each of multimedia datasets separately, the method trains models independently on each media dataset and then employs a generalised selection function to choose the appropriate models to construct a heterogeneous ensemble. The selection function is dened as a weighted combination of two criteria: the accuracy of individual models and the diversity among the models. The framework is tested on multimedia data and compared with other heterogeneous ensembles. The results show that the GDLEM is more exible and eective

An automated pattern recognition system for classifying indirect immunofluorescence images for HEp-2 cells and specimens

AbstractImmunofluorescence antinuclear antibody tests are important for diagnosis and management of autoimmune conditions; a key step that would benefit from reliable automation is the recognition of subcellular patterns suggestive of different diseases. We present a system to recognize such patterns, at cellular and specimen levels, in images of HEp-2 cells. Ensembles of SVMs were trained to classify cells into six classes based on sparse encoding of texture features with cell pyramids, capturing spatial, multi-scale structure. A similar approach was used to classify specimens into seven classes. Software implementations were submitted to an international contest hosted by ICPR 2014 (Performance Evaluation of Indirect Immunofluorescence Image Analysis Systems). Mean class accuracies obtained on heldout test data sets were 87.1% and 88.5% for cell and specimen classification respectively. These were the highest achieved in the competition, suggesting that our methods are state-of-the-art. We provide detailed descriptions and extensive experiments with various features and encoding methods

Deep Learning in Cardiology

The medical field is creating large amount of data that physicians are unable to decipher and use efficiently. Moreover, rule-based expert systems are inefficient in solving complicated medical tasks or for creating insights using big data. Deep learning has emerged as a more accurate and effective technology in a wide range of medical problems such as diagnosis, prediction and intervention. Deep learning is a representation learning method that consists of layers that transform the data non-linearly, thus, revealing hierarchical relationships and structures. In this review we survey deep learning application papers that use structured data, signal and imaging modalities from cardiology. We discuss the advantages and limitations of applying deep learning in cardiology that also apply in medicine in general, while proposing certain directions as the most viable for clinical use.Comment: 27 pages, 2 figures, 10 table