4 research outputs found
Domain Adaptation via Alignment of Operation Profile for Remaining Useful Lifetime Prediction
Effective Prognostics and Health Management (PHM) relies on accurate
prediction of the Remaining Useful Life (RUL). Data-driven RUL prediction
techniques rely heavily on the representativeness of the available
time-to-failure trajectories. Therefore, these methods may not perform well
when applied to data from new units of a fleet that follow different operating
conditions than those they were trained on. This is also known as domain
shifts. Domain adaptation (DA) methods aim to address the domain shift problem
by extracting domain invariant features. However, DA methods do not distinguish
between the different phases of operation, such as steady states or transient
phases. This can result in misalignment due to under- or over-representation of
different operation phases. This paper proposes two novel DA approaches for RUL
prediction based on an adversarial domain adaptation framework that considers
the different phases of the operation profiles separately. The proposed
methodologies align the marginal distributions of each phase of the operation
profile in the source domain with its counterpart in the target domain. The
effectiveness of the proposed methods is evaluated using the New Commercial
Modular Aero-Propulsion System (N-CMAPSS) dataset, where sub-fleets of turbofan
engines operating in one of the three different flight classes (short, medium,
and long) are treated as separate domains. The experimental results show that
the proposed methods improve the accuracy of RUL predictions compared to
current state-of-the-art DA methods.Comment: 18 pages,11 figure
SimMMDG: A Simple and Effective Framework for Multi-modal Domain Generalization
In real-world scenarios, achieving domain generalization (DG) presents
significant challenges as models are required to generalize to unknown target
distributions. Generalizing to unseen multi-modal distributions poses even
greater difficulties due to the distinct properties exhibited by different
modalities. To overcome the challenges of achieving domain generalization in
multi-modal scenarios, we propose SimMMDG, a simple yet effective multi-modal
DG framework. We argue that mapping features from different modalities into the
same embedding space impedes model generalization. To address this, we propose
splitting the features within each modality into modality-specific and
modality-shared components. We employ supervised contrastive learning on the
modality-shared features to ensure they possess joint properties and impose
distance constraints on modality-specific features to promote diversity. In
addition, we introduce a cross-modal translation module to regularize the
learned features, which can also be used for missing-modality generalization.
We demonstrate that our framework is theoretically well-supported and achieves
strong performance in multi-modal DG on the EPIC-Kitchens dataset and the novel
Human-Animal-Cartoon (HAC) dataset introduced in this paper. Our source code
and HAC dataset are available at https://github.com/donghao51/SimMMDG.Comment: NeurIPS 202
DARE-GRAM : Unsupervised Domain Adaptation Regression by Aligning Inverse Gram Matrices
Unsupervised Domain Adaptation Regression (DAR) aims to bridge the domain gap between a labeled source dataset and an unlabelled target dataset for regression problems. Recent works mostly focus on learning a deep feature encoder by minimizing the discrepancy between source and target features. In this work, we present a different perspective for the DAR problem by analyzing the closed-form ordinary least square (OLS) solution to the linear regressor in the deep domain adaptation context. Rather than aligning the original feature embedding space, we propose to align the inverse Gram matrix of the features, which is motivated by its presence in the OLS solution and the Gram matrix's ability to capture the feature correlations. Specifically, we propose a simple yet effective DAR method which leverages the pseudo-inverse low-rank property to align the scale and angle in a selected sub-space generated by the pseudo-inverse Gram matrix of the two domains. We evaluate our method on three domain adaptation regression benchmarks. Experimental results demonstrate that our method achieves state-of-the-art performance. Our code is available at https://github.com/ismailnejjar/DARE-GRAM