JUCS - Journal of Universal Computer Science 28(2): 141-159, doi: 10.3897/jucs.70549
LogSE: An Uncertainty-Based Multi-Task Loss Function for Learning Two Regression Tasks
expand article infoZeinab Ghasemi-Naraghi, Ahmad Nickabadi, Reza Safabakhsh
‡ Amirkabir University of Technology, Tehran, Iran
Open Access

Multi-task learning (MTL) is a popular method in machine learning which utilizes related information of multi tasks to learn a task more efficiently and accurately. Naively, one can benefit from MTL by using a weighted linear sum of the different tasks loss functions. Manual specification of appropriate weights is difficult and typically does not improve performance, so it is critical to find an automatic weighting strategy for MTL. Also, there are three types of uncertainties that are captured in deep learning. Epistemic uncertainty is related to the lack of data. Heteroscedas- tic aleatoric uncertainty depends on the input data and differs from one input to another. In this paper, we focus on the third type, homoscedastic aleatoric uncertainty, which is constant for differ- ent inputs and is task-dependent. There are some methods for learning uncertainty-based weights as the parameters of a model. But in this paper, we introduce a novel multi-task loss function to capture homoscedastic uncertainty in multi regression tasks models, without increasing the complexity of the network. As the experiments show, the proposed loss function aids in learning a multi regression tasks network fairly with higher accuracy in fewer training steps.

Multi-Task Learning, Bayesian Deep Network, Homoscedastic Uncertainty, Loss Function