We develop practical and theoretically grounded membership inference attacks (MIAs) against both independent and identically distributed (i.i.d.) data and graphstructured data. Building on the Bayesian decision-theoretic framework of [1], we derive the Bayes-optimal membership inference rule for node-level MIAs against graph neural networks, addressing key open questions about optimal query strategies in the graph setting. We introduce BASE and G-BASE, tractable approximations of the Bayes-optimal membership inference. G-BASE achieves superior performance compared to previously proposed classifier-based node-level MIA attacks. BASE, which is also applicable to non-graph data, matches or exceeds the performance of prior state-of-the-art MIAs, such as LiRA and RMIA, at a significantly lower computational cost. Finally, we show that BASE and RMIA are equivalent under a specific hyperparameter setting, providing a principled, Bayes-optimal justification for the RMIA attack.

Computational methods for learning to sample from the Boltzmann distribution--where the target distribution is known only up to an unnormalized energy function--have advanced significantly recently. Due to the lack of explicit target samples, however, prior diffusion-based methods, known as, often require importance-weighted estimation or complicated learning processes.

The supplementary material consists of the following. Additional Results of the DomainNet dataset for 5 and 10-shot settings with Resnet34 as backbone network are shown in Table 1. Results are reported in Tables 2 and 3 Discussion on Limitations and Societal Impacts. The architecture of the network is similar to [2]. All other hyperparameters used in our framework are described in the main paper.

Canonical work handling distribution shifts typically necessitates an entire target distribution that lands inside the training distribution.However, practical scenarios often involve only a handful target samples, potentially lying outside the training support, which requires the capability of extrapolation.In this work, we aim to provide a theoretical understanding of when extrapolation is possible and offer principled methods to achieve it without requiring an on-support target distribution.To this end, we formulate the extrapolation problem with a latent-variable model that embodies the minimal change principle in causal mechanisms.Under this formulation, we cast the extrapolation problem into a latent-variable identification problem.We provide realistic conditions on shift properties and the estimation objectives that lead to identification even when only one off-support target sample is available, tackling the most challenging scenarios.Our theory reveals the intricate interplay between the underlying manifold's smoothness and the shift properties.We showcase how our theoretical results inform the design of practical adaptation algorithms.

D istillation ( RCD-KD) which can effectively adapt to student's network capability via dynamically selecting suitable target domain samples for knowledge transferring.

Unsupervised domain adaptation (UDA) aims to enhance the generalization capability ofacertain model from asource domain toatargetdomain.