After some pictures from Kyoto 京都, Fall and Winter, some pictures from Spring and Summer. In two weeks, my sabbatical year at Kyoto University will come to an end. It is difficult to sum up what this year has meant. It gave me the time and space to look at things differently, to revisit projects that needed a fresh perspective, and to let new ideas emerge. But above all, it was a wonderful opportunity to discover Kyoto slowly, through everyday life and through the changing seasons. From autumn colours and winter light to cherry blossoms, summer heat and festival evenings, the city never stopped surprising me…
The field of imbalanced self-supervised learning, especially in the context of tabular data, has not been extensively studied. Existing research has predominantly focused on image datasets. This paper aims to fill this gap by examining the specific challenges posed by data imbalance in self-supervised learning in the domain of tabular data, with a primary focus on autoencoders. Autoencoders are widely employed for learning and constructing a new representation of a dataset, particularly for dimensionality reduction. They are also often used for generative model learning, as seen in variational autoencoders. When dealing with mixed tabular data, qualitative variables are often encoded using a one-hot encoder with a standard loss function (MSE or Cross Entropy). In this paper, we analyze the drawbacks of this approach, especially when categorical variables are imbalanced. We propose a novel metric to balance learning: a Multi-Supervised Balanced MSE. This approach reduces the reconstruction error by balancing the influence of variables. Finally, we empirically demonstrate that this new metric, compared to the standard MSE: i) outperforms when the dataset is imbalanced, especially when the learning process is insufficient, and ii) provides similar results in the opposite case.
Marc will give a talk at the Kyoto Symposium in 京都市 on November 29th, on “Multivariate comonotonicity and multivariate dispersion orderings” based on some joint work with also Alfred (the paper can be found online on http://papers.ssrn.com/).
"sendo l'intento mio scrivere cosa utile a chi la intende…"