Imbalanced classes and dimensional disasters are critical challenges in medical image classification. As a classical machine learning model, the n -gram model has shown excellent performance in addressing this issue in text classification. In this study, we proposed an algorithm to classify medical images by extracting their n -gram semantic features. This algorithm first converts an image classification problem to a text classification problem by building an n -gram corpus for an image. After that, the algorithm was based on the n -gram model to classify images. The algorithm was evaluated by two independent public datasets. The first experiment is to diagnose benign and malignant thyroid nodules. The best area under the curve (AUC) is 0.989. The second experiment is to diagnose the type of fundus lesion. The best result is that it correctly identified 86.667% of patients with dry age-related macular degeneration (AMD), 93.333% of patients with diabetic macular edema (DME), and 93.333% of normal individuals.

Solving Mathematics Word Problem (MWP) is a basic ability of humanity, which can be mastered by most students at a young age. The existing artificial intelligence system is not good enough in numerical questions, like MWPs. The hard part of this problem is translating natural language sentences in MWP into mathematical expressions or equations. In recent researches, the Transformer network, which proved a great success in machine translation, is applied to automatic mathematic word problem-solving. While previous works have only shown the ability of Transformer model in MWP, how multiple factors such as encoding, decoding, and pre-training affect the performance of Transformer model has not received enough attention. The study is the first to examine the role of these factors experimentally. This paper proposes several methods to improve Transformer network performance in MWPs under the basis of previous studies, achieves higher accuracy compared to the previous state of the art. Pre-training on target tasks dataset improves the translation quality of the Transformer model greatly. Different token encoding and search algorithms also benefit prediction accuracy at the expense of more training and testing time.

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