scholarly journals Imbalanced learning: Improving classification of diabetic neuropathy from magnetic resonance imaging

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243907
Author(s):  
Kevin Teh ◽  
Paul Armitage ◽  
Solomon Tesfaye ◽  
Dinesh Selvarajah ◽  
Iain D. Wilkinson

One of the fundamental challenges when dealing with medical imaging datasets is class imbalance. Class imbalance happens where an instance in the class of interest is relatively low, when compared to the rest of the data. This study aims to apply oversampling strategies in an attempt to balance the classes and improve classification performance. We evaluated four different classifiers from k-nearest neighbors (k-NN), support vector machine (SVM), multilayer perceptron (MLP) and decision trees (DT) with 73 oversampling strategies. In this work, we used imbalanced learning oversampling techniques to improve classification in datasets that are distinctively sparser and clustered. This work reports the best oversampling and classifier combinations and concludes that the usage of oversampling methods always outperforms no oversampling strategies hence improving the classification results.

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0239615
Author(s):  
Maeri Yamamoto ◽  
Epifanio Bagarinao ◽  
Itaru Kushima ◽  
Tsutomu Takahashi ◽  
Daiki Sasabayashi ◽  
...  

Structural brain alterations have been repeatedly reported in schizophrenia; however, the pathophysiology of its alterations remains unclear. Multivariate pattern recognition analysis such as support vector machines can classify patients and healthy controls by detecting subtle and spatially distributed patterns of structural alterations. We aimed to use a support vector machine to distinguish patients with schizophrenia from control participants on the basis of structural magnetic resonance imaging data and delineate the patterns of structural alterations that significantly contributed to the classification performance. We used independent datasets from different sites with different magnetic resonance imaging scanners, protocols and clinical characteristics of the patient group to achieve a more accurate estimate of the classification performance of support vector machines. We developed a support vector machine classifier using the dataset from one site (101 participants) and evaluated the performance of the trained support vector machine using a dataset from the other site (97 participants) and vice versa. We assessed the performance of the trained support vector machines in each support vector machine classifier. Both support vector machine classifiers attained a classification accuracy of >70% with two independent datasets indicating a consistently high performance of support vector machines even when used to classify data from different sites, scanners and different acquisition protocols. The regions contributing to the classification accuracy included the bilateral medial frontal cortex, superior temporal cortex, insula, occipital cortex, cerebellum, and thalamus, which have been reported to be related to the pathogenesis of schizophrenia. These results indicated that the support vector machine could detect subtle structural brain alterations and might aid our understanding of the pathophysiology of these changes in schizophrenia, which could be one of the diagnostic findings of schizophrenia.


2019 ◽  
Vol 8 (4) ◽  
pp. 2514-2519

Microarray is a fast and rapid growing technology which plays dynamic role in the medical field. It is an advanced than MRI (Magnetic Resonance Imaging) and CT scanning (Computerised Tomography). The purpose of this work is to make fine perfection against the gene expression. In this study the two clustering are used which fuzzy c means and k means and also it classifies with better results. The microarray data base indicates the classification in support vector machine. Segmentation is most important step in microarray image. The classification in support vector machine is compared with other two classifiers which means the k nearest neighbour and with the Bayes classifiers.


Author(s):  
Ángel Freddy Godoy Viera

Las técnicas de aprendizaje de máquina continúan siendo muy utilizadas para la minería de texto. Para este artículo se realizó una revisión de literatura en periódicos científicos publicados en los años de 2010 y 2011, con el objetivo de identificar las principales formas de aprendizaje de máquina empleadas para la minería de texto. Se utilizó estadística descriptiva para organizar, resumir y analizar los datos encontrados, y se presentó una descripción resumida de las principales encontradas. En los artículos analizados se hallaron 13 aplicadas para la minería de texto, el 83% de los artículos mencionaban de 1 a 3 técnicas de aprendizaje de máquina, las principales usadas por los autores en los artículos estudiados fueron support vector machine (svm), k-means (k-m),k-nearest neighbors (k-nn), naive bayes (nb), self-organizing maps (som). Los pares que aparecen con mayor frecuencia son svm/nb, svm/k-nn, svm/decission tree.


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