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Feature-Based Semantics-Aware Scheduling for Energy-Harvesting Federated Learning

Jeong, Eunjeong, Perin, Giovanni, Yang, Howard H., Pappas, Nikolaos

arXiv.org Artificial Intelligence

Federated Learning (FL) on resource-constrained edge devices faces a critical challenge: The computational energy required for training Deep Neural Networks (DNNs) often dominates communication costs. However, most existing Energy-Harvesting FL (EHFL) strategies fail to account for this reality, resulting in wasted energy due to redundant local computations. For efficient and proactive resource management, algorithms that predict local update contributions must be devised. We propose a lightweight client scheduling framework using the Version Age of Information (VAoI), a semantics-aware metric that quantifies update timeliness and significance. Crucially, we overcome VAoI's typical prohibitive computational cost, which requires statistical distance over the entire parameter space, by introducing a feature-based proxy. This proxy estimates model redundancy using intermediate-layer extraction from a single forward pass, dramatically reducing computational complexity. Experiments conducted under extreme non-IID data distributions and scarce energy availability demonstrate superior learning performance while achieving energy reduction compared to existing baseline selection policies. Our framework establishes semantics-aware scheduling as a practical and vital solution for EHFL in realistic scenarios where training costs dominate transmission costs.


Stochastic Approximation with Delayed Updates: Finite-Time Rates under Markovian Sampling

Adibi, Arman, Fabbro, Nicolo Dal, Schenato, Luca, Kulkarni, Sanjeev, Poor, H. Vincent, Pappas, George J., Hassani, Hamed, Mitra, Aritra

arXiv.org Artificial Intelligence

Motivated by applications in large-scale and multi-agent reinforcement learning, we study the non-asymptotic performance of stochastic approximation (SA) schemes with delayed updates under Markovian sampling. While the effect of delays has been extensively studied for optimization, the manner in which they interact with the underlying Markov process to shape the finite-time performance of SA remains poorly understood. In this context, our first main contribution is to show that under time-varying bounded delays, the delayed SA update rule guarantees exponentially fast convergence of the \emph{last iterate} to a ball around the SA operator's fixed point. Notably, our bound is \emph{tight} in its dependence on both the maximum delay $\tau_{max}$, and the mixing time $\tau_{mix}$. To achieve this tight bound, we develop a novel inductive proof technique that, unlike various existing delayed-optimization analyses, relies on establishing uniform boundedness of the iterates. As such, our proof may be of independent interest. Next, to mitigate the impact of the maximum delay on the convergence rate, we provide the first finite-time analysis of a delay-adaptive SA scheme under Markovian sampling. In particular, we show that the exponent of convergence of this scheme gets scaled down by $\tau_{avg}$, as opposed to $\tau_{max}$ for the vanilla delayed SA rule; here, $\tau_{avg}$ denotes the average delay across all iterations. Moreover, the adaptive scheme requires no prior knowledge of the delay sequence for step-size tuning. Our theoretical findings shed light on the finite-time effects of delays for a broad class of algorithms, including TD learning, Q-learning, and stochastic gradient descent under Markovian sampling.


Graph Neural Networks for Multi-Robot Active Information Acquisition

Tzes, Mariliza, Bousias, Nikolaos, Chatzipantazis, Evangelos, Pappas, George J.

arXiv.org Artificial Intelligence

This paper addresses the Multi-Robot Active Information Acquisition (AIA) problem, where a team of mobile robots, communicating through an underlying graph, estimates a hidden state expressing a phenomenon of interest. Applications like target tracking, coverage and SLAM can be expressed in this framework. Existing approaches, though, are either not scalable, unable to handle dynamic phenomena or not robust to changes in the communication graph. To counter these shortcomings, we propose an Information-aware Graph Block Network (I-GBNet), an AIA adaptation of Graph Neural Networks, that aggregates information over the graph representation and provides sequential-decision making in a distributed manner. The I-GBNet, trained via imitation learning with a centralized sampling-based expert solver, exhibits permutation equivariance and time invariance, while harnessing the superior scalability, robustness and generalizability to previously unseen environments and robot configurations. Experiments on significantly larger graphs and dimensionality of the hidden state and more complex environments than those seen in training validate the properties of the proposed architecture and its efficacy in the application of localization and tracking of dynamic targets.


'Voice Skins' Could Let Gamers Customize Their Voices Online

#artificialintelligence

Online, we can be whoever we want--a bulked-up soldier, a freakish banana, Sonic the Hedgehog--only until we start speaking. Over any online game's built-in chat or Discord, our voices have the power to immediately reveal information about our geographic region, our gender, even our ethnicity. Now, a company that makes "voice skins" is trying to change that, too. "You go online and have the freedom to design your avatar, choose your username, pick what communities you jump into. You can design your online persona completely separately from who you are in the real world," said Modulate founder Mike Pappas.


This AI lets you deepfake your voice to speak like Barack Obama

#artificialintelligence

The accent, emotion, and intonation are all mine. But somehow I now sound like a youngish woman with a high-pitched voice. My feminine "voice skin" was created by Modulate.ai, The firm uses machine learning to copy, model, and manipulate the properties of voice in a powerful new way. The technology goes far beyond the simple voice filters that can let you sound like Kylo Ren.


This AI lets you deepfake your voice to speak like Barack Obama

#artificialintelligence

The accent, emotion, and intonation are all mine. But somehow I now sound like a youngish woman with a high-pitched voice. My feminine "voice skin" was created by Modulate.ai, The firm uses machine learning to copy, model, and manipulate the properties of voice in a powerful new way. The technology goes far beyond the simple voice filters that can let you sound like Kylo Ren.


Using Redescription Mining to Relate Clinical and Biological Characteristics of Cognitively Impaired and Alzheimer's Disease Patients

Mihelčić, Matej, Šimić, Goran, Leko, Mirjana Babić, Lavrač, Nada, Džeroski, Sašo, Šmuc, Tomislav

arXiv.org Artificial Intelligence

We used redescription mining to find interpretable rules revealing associations between those determinants that provide insights about the Alzheimer's disease (AD). We extended the CLUS-RM redescription mining algorithm to a constraint-based redescription mining (CBRM) setting, which enables several modes of targeted exploration of specific, user-constrained associations. Redescription mining enabled finding specific constructs of clinical and biological attributes that describe many groups of subjects of different size, homogeneity and levels of cognitive impairment. We confirmed some previously known findings. However, in some instances, as with the attributes: testosterone, the imaging attribute Spatial Pattern of Abnormalities for Recognition of Early AD, as well as the levels of leptin and angiopoietin-2 in plasma, we corroborated previously debatable findings or provided additional information about these variables and their association with AD pathogenesis. Applying redescription mining on ADNI data resulted with the discovery of one largely unknown attribute: the Pregnancy-Associated Protein-A (PAPP-A), which we found highly associated with cognitive impairment in AD. Statistically significant correlations (p <= 0.01) were found between PAPP-A and various different clinical tests. The high importance of this finding lies in the fact that PAPP-A is a metalloproteinase, known to cleave insulin-like growth factor binding proteins. Since it also shares similar substrates with A Disintegrin and the Metalloproteinase family of enzymes that act as {\alpha}-secretase to physiologically cleave amyloid precursor protein (APP) in the non-amyloidogenic pathway, it could be directly involved in the metabolism of APP very early during the disease course. Therefore, further studies should investigate the role of PAPP-A in the development of AD more thoroughly.


How AI is Changing Customer Service

#artificialintelligence

Artificial intelligence, which uses algorithms and rules-based logic to automate a wide variety of tasks within many verticals, is hot. It occupies the top spot in 2017 tech trend lists from such notable companies as Ericsson and Gartner. Cognitive systems and AI adoption across a broad range of industries are likely to drive worldwide revenues from nearly $8 billion in 2016 to more than $47 billion in 2020, according to IDC. Automated customer service agents is one of the key AI areas that attracted investment last year, the research firm noted. "From better purchase recommendations, to smarter customer service that predicts what a consumer is actually trying to do, AI promises to fundamentally transform entire businesses and industries," said Scott Horn, CMO at customer engagement solution provider [24]7.