Benchmarking large-scale data management for Internet of Things

The Journal of Supercomputing - In the current era of the Internet of Things (IoT), massive number of sensors are used in our daily lives. Sensors are everywhere around us. They exist in our homes,...     

Learning the set covering machine by bound minimization and margin-sparsity trade-off

We investigate classifiers in the sample compression framework that can be specified by two distinct sources of information: a compression set and a message string of additional information. In the compression setting, a reconstruction function specifies a classifier when given this information. We examine how an efficient redistribution of this reconstruction information can lead to more general classifiers. In particular, we derive risk bounds that can provide an explicit control over the sparsity of the classifier and the magnitude of its separating margin and a capability to perform a margin-sparsity trade-off in favor of better classifiers. We show how an application to the set covering machine algorithm results in novel learning strategies. We also show that these risk bounds are tighter than their traditional counterparts such as VC-dimension and Rademacher complexity-based bounds that explicitly take into account the hypothesis class complexity. Finally, we show how these bounds are able to guide the model selection for the set covering machine algorithm enabling it to learn by bound minimization.     

Automatic detection of gadolinium-enhancing multiple sclerosis lesions in brain MRI using conditional random fields

Gadolinium-enhancing lesions in brain magnetic resonance imaging of multiple sclerosis (MS) patients are of great interest since they are markers of disease activity. Identification of gadolinium-enhancing lesions is particularly challenging because the vast majority of enhancing voxels are associated with normal structures, particularly blood vessels. Furthermore, these lesions are typically small and in close proximity to vessels. In this paper, we present an automatic, probabilistic framework for segmentation of gadolinium-enhancing lesions in MS using conditional random fields. Our approach, through the integration of different components, encodes different information such as correspondence between the intensities and tissue labels, patterns in the labels, or patterns in the intensities. The proposed algorithm is evaluated on 80 multimodal clinical datasets acquired from relapsing-remitting MS patients in the context of multicenter clinical trials. The experimental results exhibit a sensitivity of 98% with a low false positive lesion count. The performance of the proposed algorithm is also compared to a logistic regression classifier, a support vector machine and a Markov random field approach. The results demonstrate superior performance of the proposed algorithm at successfully detecting all of the gadolinium-enhancing lesions while maintaining a low false positive lesion count.