Publications

2026

• Adaptive Multi-UAV Relay Deployment Framework in Satellite Aerial Ground Integrated Systems
  
  • Bhola Bhola
  • Chen Yu-Jia
  • Balakrishnan Ashutosh
  • De Swades
  • Wang Li-Chun
  , 2026. <div><p>The sixth-generation (6G) communication networks are expected to provide high data rates, ultra-reliable communication, and massive connectivity, especially in challenging environments such as dense urban areas and disaster-affected regions. However, traditional terrestrial-only networks face significant challenges in these scenarios, including signal blockages from high-rise buildings, traffic congestion, and dynamic user distributions. To address these limitations, we propose the adaptive multi-UAV deployment (AMUD) framework within satellite airground integrated networks (SAGINs). The AMUD framework dynamically deploys amplify-and-forward multiple unmanned aerial vehicle relay (UAVr) in with low Earth orbit (LEO) satellites to improve coverage, alleviate congestion, and ensure reliable communication in non-line-of-sight and high-demand conditions. We formulate an optimization problem that aims to jointly maximize the energy efficiency of the total network and the total capacity while ensuring the fairness of the total capacity and satisfying the user's requirements. The simulation results demonstrate that AMUD improves the total capacity of the network, improves the total energy efficiency, and increases the fairness of the capacity compared to traditional LEO satellite and ground base station (LEO-GBS) only systems.</p></div> (10.48550/arXiv.2604.20466)
  DOI : 10.48550/arXiv.2604.20466
• INSTANT: COMPRESSING GRADIENTS AND ACTIVATIONS FOR RESOURCE-EFFICIENT TRAINING
  
  • Doan Tuan-Kiet
  • Tran Trung-Hieu
  • Tartaglione Enzo
  • Simidjievski Nikola
  • Nguyen Van-Tam
  , 2026. <div><p>Deep learning has advanced at an unprecedented pace. This progress has led to a significant increase in its complexity. However, despite extensive research on accelerating inference, training deep models directly within a resource-constrained budget remains a considerable challenge due to its high computational and memory requirements. In this paper, we introduce INSTANT (compressIng gradieNtS and acTivAtions for resource-efficieNt Training), a method designed to address both the computational and the memory bottlenecks when training. INSTANT reduces resource demands during backpropagation by projecting gradients and activations into a low-rank subspace and performing computation within that compressed representation. Experimental results demonstrate that INSTANT achieves a 15× reduction in computational cost and 32× reduction in activation memory with negligible impact on model performance. The code is available at INSTANT. * Equal contribution.</p><p>• We introduce a low-cost calibration technique to generate calibrated orthonormal bases for tensor projection, enabling significant reductions in memory and computations (Sec. 3.2). • We project activation tensors and gradients onto these orthonormal bases. To our knowledge, this is the first work to exploit the low-rank structure of activation gradients for all types of data distribution. We provide an error analysis of our gradient compression, illustrating that a high compression ratio is achievable with limited performance degradation (Sec. 3.3). • We evaluate INSTANT across multiple datasets and model architectures, consistently demonstrating good performance, achieving up to 32× memory savings and 15× computational cost reduction with only a 1% trade-off in accuracy compared to vanilla fine-tuning (Sec. 4).</p></div> <div>RELATED WORK<p>Activation compression. Activation compression is a recently emerging research direction that addresses the memory challenges during training. This approach offers several key advantages based on the following observations: (i) model weights remain uncompressed during training, thereby preserving their expressive capacity; (ii) activations are often large and exhibit significant redundancy, making them suitable for compression (Sakr &amp; Khailany, 2024; Miles et al., 2024). (Nguyen et al., 2024) applies SVD to compress activations to reduce huge memory usage for activations. However, this approach raises substantial computational overhead due to the high cost of performing SVD in each training iteration. (Sakr &amp; Khailany, 2024) (ESPACE) tackles SVD computational expense by using calibrated subspaces, which are periodically updated, to compress activations. They enable activation compression in the forward pass, reducing computational overhead in both the forward and backward phases. However, ESPACE is prone to error accumulation, as it relies on the universal fixed subspace across varying activations.</p><p>Optimizer state compression. Weight gradients are inherently low-rank (Yang et al., 2023a). Previous studies (Bernstein et al., 2018; Vogels et al., 2019) have leveraged this characteristic to address communication bottlenecks in distributed learning by reducing inter-device data transmission. GaLore (Zhao et al., 2024) and its variances (Muhamed et al., 2024; Shamshoum et al., 2025) leverage the low-rank property of weight gradients for compressing them to reduce memory usage in the optimizer state significantly. CompAct Shamshoum et al. ( 2025) further reduces the memory overhead</p></div>
• Polynomial-time thermalization and Gibbs sampling from system-bath couplings
  
  • Slezak Samuel
  • Scandi Matteo
  • Alhambra Álvaro M.
  • França Daniel Stilck
  • Rouzé Cambyse
  , 2026. Many physical phenomena, including thermalization in open quantum systems and quantum Gibbs sampling, are modeled by Lindbladians approximating a system weakly coupled to a bath. Understanding the convergence speed of these Lindbladians to their steady states is crucial for bounding algorithmic runtimes and thermalization timescales. We study two such families of processes: one characterizing a repeated-interaction Gibbs sampling algorithm, and another modeling open many-body quantum thermalization. We prove that both converge in polynomial time for several non-commuting systems, including high-temperature local lattices, weakly interacting fermions, and 1D spin chains. These results demonstrate that simple dissipative quantum algorithms can prepare complex Gibbs states and that Lindblad dynamics accurately capture thermal relaxation. Our proofs rely on a novel technical result that extrapolates spectral gap lower bounds from quasi-local Lindbladians to the non-local generators governing these dynamics.
• Drop the mask! GAMM—A Taxonomy for Graph Attributes Missing Mechanisms
  
  • Serrano Richard
  • Jeudy Baptiste
  • Laclau Charlotte
  • Largeron Christine
  , 2026, 16513, pp.298–311. Exploring missing data in attributed graphs introduces unique challenges beyond those found in tabular datasets. In this work, we extend the taxonomy for missing data mechanisms to attributed graphs by proposing GAMM (Graph Attributes Missing Mechanisms), a framework that systematically links missingness probability to both node attributes and the underlying graph structure. Our taxonomy enriches the conventional definitions of masking mechanisms by introducing graph-specific dependencies. We empirically demonstrate that state-of-the-art imputation methods, while effective on traditional masks, significantly struggle when confronted with these more realistic graph-aware missingness scenarios. (10.1007/978-3-032-23833-7_22)
  DOI : 10.1007/978-3-032-23833-7_22
• Tighter Bounds for Query Answering with Guarded TGDs
  
  • Amarilli Antoine
  • Benedikt Michael
  Logical Methods in Computer Science, Logical Methods in Computer Science Association, 2026. We consider the complexity of the open-world query answering problem, where we wish to determine certain answers to conjunctive queries over incomplete datasets specified by an initial set of facts and a set of guarded TGDs. This problem has been well-studied in the literature and is decidable but with a high complexity, namely, it is 2EXPTIME complete. Further, the complexity shrinks by one exponential when the arity is fixed. We show in this paper how we can obtain better complexity bounds when considering separately the arity of the guard atom and that of the additional atoms, called the side signature. Our results make use of the technique of linearizing guarded TGDs, introduced in Gottlob, Manna, and Pieris. Specifically, we present a variant of the linearization process, making use of a restricted version of the chase that we recently introduced. Our results imply that open-world query answering with guarded TGDs can be solved in EXPTIME with arbitrary-arity guard relations if we simply bound the arity of the side signature; and that the complexity drops to NP if we fix the side signature and bound the width of the dependencies.
• Doppler-Shannon Association in Vehicular Networks: A Stochastic Geometry Analysis
  
  • Balakrishnan Ashutosh
  • Baccelli François
  • Jhawar Sanjoy Kumar
  • Martins Philippe
  , 2026. Historically, in cellular networks, the user equipment (UE) association with a base station (BS) has been largely confined to nearest BS association strategies. Unlike cellular networks wherein the BSs are static, vehicular networks are prone to high mobility, resulting in the UE experiencing a Doppler shift. The Doppler shift further results in the fading channel exhibiting high temporal variability. In this work, we present a novel stochastic geometry framework, modeling the effects of the Doppler shift on the physical layer network performance through the coherence time. First, the statistics of the Doppler shift are studied in a two-and three-dimensional Poisson point process (PPP) setting. The distribution and the geometric factors influencing the Doppler shift are analyzed. Next, we propose Doppler shift aware utilities, modeling the Doppler shift induced Shannon rate achievable in time-selective fading links. Through these utilities, we analytically study the outage and coverage probabilities for a UE to achieve a given quality of service. These probabilities are computed based on the optimal BS association in vehicular networks, which goes beyond the closest Euclidean distance. In the UE-BS line of sight, the novel BS association policies factor the BS direction of motion and the fading gain, in addition to the Euclidean distance. We show that the nearest BS is no longer the optimal BS association, resulting in non-convex coverage tessellations associated with the BSs. Our analytical and simulation results illustrate the need for a Doppler shift correction, complementing the ideal SNR based Shannon performance. The network performance achieved through the proposed Doppler-Shannon based association is proved, analytically as well as through simulations, to be superior to the classical Shannon based association achieving spatially averaged gains up to 90% and 22% in a 2D and 3D setting, respectively.
• Functional requirements decomposition in set-based design
  
  • Sun Minghui
  • Chen Zhaoyang
  • Bakirtzis Georgios
  • Jafarzadeh Hassan
  • Fleming Cody
  Design Science, Cambridge University Press, 2026, 12, pp.e12, 1-35. Designing systems is typically uncertain and ambiguous at the early stages. Set-based design (SBD) supports alternative exploration and gradual uncertainty reduction during the early lifecycle, making it practical for complex system design. In parallel, functional requirements decomposition helps to advance the design incrementally. However, current literature on SBD lacks formal guidance on how to decompose functional requirements. To bridge this gap, we introduce a four-step method to decompose functional requirements for SBD hierarchically. We systematically define, reason and narrow the sets, breaking down the functional requirements into formal sub-requirements. This method allows parallel abstraction, ensuring the resulting system satisfies the top-level functional requirements (10.1017/dsj.2026.10053)
  DOI : 10.1017/dsj.2026.10053
• Proving execution platform contracts
  
  • Bourgeoisat Dorian
  • Brandner Florian
  • Kühne Ulrich
  Microprocessors and Microsystems: Embedded Hardware Design, Elsevier, 2026, 122, pp.105273. Since the discovery of the Spectre vulnerability and its media coverage, micro-architectural side channel attacks have gained considerable interest, both in research and the general public. These side channels threaten many usage scenarios that have become central to everybody’s daily lives. Be it cloud services, where virtual machines share the same physical hardware, be it web applications on different tabs of one’s web browser, or be it applications on one’s smart phone. In all these cases, sensitive data might be processed by software running on a hardware platform along with potentially malicious other pieces of software. Due to the micro-architectural side channels the malicious software may observe how this sensitive data is processed and thus extract information on the data – effectively leaking sensitive information. New vulnerabilities and counter-measures are discovered and publicized at a frantic rate, calling for a sea change in the way micro-architecture designs and software process sensitive data. Hardware/software contracts were recently proposed to establish a formal framework, providing formal guarantees against information leakage and allowing a clear separation of concerns between hardware and software. However, these contracts only focus on the interactions between the micro-architecture and the application software, missing a crucial element that governs and mediates most of these interactions: system software – such as operating systems or hypervisors. The objective of this work is to fill this gap and extend the contracts to include the operating system (OS). For this we formalize thread and memory management policies provided by the OS on top of a hardware model in order to study information leakage on such a platform. We first show through an exploration of concrete examples that the OS plays a crucial role in providing security guarantees to software processing sensitive data. Finally, we apply an inductive proof strategy on these formal platform models in order to establish contracts between the software, the OS, and the hardware. (10.1016/j.micpro.2026.105273)
  DOI : 10.1016/j.micpro.2026.105273
• Verification of statistical wave field theory reverberation time predictions
  
  • Prinn Albert G
  • Badeau Roland
  Applied Acoustics, Elsevier, 2026, 250, pp.111337, 1-12. Classical statistical reverberation models, such as Sabine’s and Eyring’s models, provide practitioners with efficient estimates of a room’s reverberation time based on its volume, surface area, and the absorption coefficients of its boundary surfaces. Absorption coefficients quantify sound absorption in terms of energy, which can be of limited use when detailed descriptions of interior acoustic fields are required. In such cases, describing absorption in terms of impedance or admittance is preferable. A statistical theory of wave fields has recently been proposed in the literature. The statistical wave field theory predicts reverberation time at high frequencies based on the locally reacting impedances of the surfaces present in a room. This study verifies the predictions of the statistical wave field theory using various numerical models. Additionally, predictions of the theory are indirectly validated by using the theory to estimate surface impedances from measured data, which are in turn used to predict reverberation times in a shoebox-shaped room and in a reverberation chamber. (10.1016/j.apacoust.2026.111337)
  DOI : 10.1016/j.apacoust.2026.111337
• Gaussian Process Regression of Steering Vectors With Physics-Aware Deep Composite Kernels for Augmented Listening
  
  • Di Carlo Diego
  • Koyama Shoichi
  • Aditya Arie Nugraha
  • Mathieu Fontaine
  • Yoshiaki Bando
  • Kazuyoshi Yoshii
  , 2026. This paper investigates continuous representations of steering vectors over frequency and microphone/source positions for augmented listening (e.g., spatial filtering and binaural rendering), enabling user-parameterized control of the reproduced sound field. Steering vectors have typically been used for representing the spatial response of a microphone array as a function of the look-up direction. The basic algebraic representation of these quantities assuming an idealized environment cannot deal with the scattering effect of the sound field. One may thus collect a discrete set of real steering vectors measured in dedicated facilities and super-resolve (i.e., upsample) them. Recently, physics-aware deep learning methods have been effectively used for this purpose. Such deterministic super-resolution, however, suffers from the overfitting problem due to the non-uniform uncertainty over the measurement space. To solve this problem, we integrate an expressive representation based on the neural field (NF) into the principled probabilistic framework based on the Gaussian process (GP). Specifically, we propose a physics-aware composite kernel that models the directional incoming waves and the subsequent scattering effect. Our comprehensive comparative experiment showed the effectiveness of the proposed method under data insufficiency conditions. In downstream tasks such as speech enhancement and binaural rendering using the simulated data of the SPEAR challenge, the oracle performances were attained with less than ten times fewer measurements.
• Revealing the Power Dynamics of Collaborative Sense-Making Supported by Participatory Data Physicalization
  
  • Cazacu Silvia
  • Panagiotidou Georgia
  • Moere Andrew Vande
  , 2026, pp.1186, Pages 1 - 21. While it is proven that the individual construction of a data physicalization aids personal sense-making, little is known about how sense-making is negotiated when it is shared by multiple, co-located participants. Since participatory data physicalization can inadvertently prioritize dominant views, we interpreted data feminism principles to design a collaborative physicalization construction process that empowers stakeholders and participants to co-determine how meanings are represented. This process revealed how the interplay of physical and non-physical actions during construction negotiations supported collaborative sense-making among 14 groups of 55 participants during 4 workshops, enabling us to articulate how explicit power is embodied by the physicalization artifact and negotiated between authoring and collaborating participants, and facilitators; whereas tacit power operates through artifact meanings, participant identity and design decisions. By providing one operationalization of data-feminist critique into the form of design requirements, our contributions support the design of more equitable physicalization and visualization construction methods. (10.1145/3772318.3791052)
  DOI : 10.1145/3772318.3791052
• Craft-Based Data Physicalization: Opportunities and Challenges
  
  • Bakhtiari Bahare
  • Daneshzand Foroozan
  • Sauvé Kim
  • Bressa Nathalie
  • Huron Samuel
  • Oehlberg Lora
  • Carpendale Sheelagh
  • Somanath Sowmya
  • Perin Charles
  , 2026, pp.Article No.: 931, Pages 1 - 8. This three-hour workshop will gather data visualization and HCI researchers and practitioners to explore the possibilities of data representation using craft techniques. Participants will submit a 2-4 page document including (i) a statement of their craft experience, (ii) representative images of physicalizations they have created using this craft technique, and (iii) a discussion of opportunities and challenges for physicalizing data in their craft domain. During the workshop, participants and organizers will work in groups to brainstorm ways of representing data through their shared craft of interest. Then, every group proposes a synthesis of opportunities and challenges of the craft technique they worked with. Together, the community will chart a research agenda on how craft can ex- pand the design space of data physicalization, inform the creation of more expressive and accessible authoring tools, and raise new questions around aesthetics, accuracy, and the role of slow making in data representation. (10.1145/3772363.3778766)
  DOI : 10.1145/3772363.3778766
• Promises, Perils, and (Timely) Heuristics for Mining Coding Agent Activity
  
  • Robbes Romain
  • Matricon Théo
  • Degueule Thomas
  • Hora Andre
  • Zacchiroli Stefano
  , 2026. In 2025, coding agents have seen a very rapid adoption. Coding agents leverage Large Language Models (LLMs) in ways that are markedly different from LLM-based code completion, making their study critical. Moreover, unlike LLM-based completion, coding agents leave visible traces in software repositories, enabling the use of MSR techniques to study their impact on SE practices. This paper documents the promises, perils, and heuristics that we have gathered from studying coding agent activity on GitHub. (10.1145/3793302.3793375)
  DOI : 10.1145/3793302.3793375
• Scaffolded Vulnerability: Chatbot-Mediated Reciprocal Self-Disclosure and Need-Supportive Interaction in Couples
  
  • Jiang Zhuoqun
  • Yeo Shunyi
  • Herremans Dorien
  • Perrault Simon
  , 2026, pp.Article No.: 1296, Pages 1 - 39. Reciprocal self-disclosure and need-supportive behavior are essential for close relationships, yet prior systems rarely engage the motivational underpinnings, autonomy, competence, and relatedness, that help partners internalize supportive behaviors. We introduce a Self-Determination Theory-guided chatbot that mediates selfdisclosure between romantic partners by scaffolding these needs through structured questions and reflection follow-ups. In a randomized study (N=72; 36 couples), we compared three conditions: Partner Support (PS: chatbot support + partner-reflection scaffolds), Direct Support (DS: chatbot support only), and Basic Prompt (BP: questions only). PS conversations were longest and most engaged; PS and DS elicited deeper disclosures and stronger relatedness support than BP. Within PS, reflection phases concentrated partnerprovided need support. Controlled motivation decreased across conditions, closeness increased only in PS, and vitality declined in BP. We contribute empirical evidence that SDT-guided mediation amplifies support and closeness, a design blueprint for relatedness technologies, and an SDT framework for advancing AI-mediated conversation design. (10.1145/3772318.3791370)
  DOI : 10.1145/3772318.3791370
• Challenges in Synchronous &amp; Remote Collaboration Around Visualization
  
  • Brehmer Matthew
  • Cordeil Maxime
  • Hurter Christophe
  • Itoh Takayuki
  • Büschel Wolfgang
  • Jasim Mahmood
  • Prouzeau Arnaud
  • Saffo David
  • Bartram Lyn
  • Carpendale Sheelagh
  • Zhu-Tian Chen
  • Cunningham Andrew
  • Dwyer Tim
  • Huron Samuel
  • Itoh Masahiko
  • Joshi Alark
  • Kiyokawa Kiyoshi
  • Kuzuoka Hideaki
  • Lee Bongshin
  • Molina León Gabriela
  • Reiterer Harald
  • Ryskeldiev Bektur
  • Schwabish Jonathan
  • Smith Brian A
  • Sumi Yasuyuki
  • Suzuki Ryo
  • Tang Anthony
  • Yang Yalong
  • Zhao Jian
  , 2026, pp.Article No.: 1007, 1-17. We characterize 16 challenges faced by those investigating and developing remote and synchronous collaborative experiences around visualization. Our work reflects the perspectives and prior research efforts of an international group of 29 experts from across human computer interaction and visualization sub-communities. The challenges are anchored around five collaborative activities that exhibit a centrality of visualization and multimodal communication. These activities include exploratory data analysis, creative ideation, visualization-rich presentations, joint decision making grounded in data, and real-time data monitoring. The challenges also reflect the changing dynamics of these activities in the face of recent advances in extended reality (XR) and artificial intelligence (AI). As an organizing scheme for future research at the intersection of visualization and computer-supported cooperative work, we align the challenges with a sequence of four sets of research and development activities: technological choices, social factors, AI assistance, and evaluation. (10.1145/3772318.3791117)
  DOI : 10.1145/3772318.3791117
• AI Agents and the Future of Deliberation: Designing Human-AI Collaboration for Democratic Dialogue
  
  • Zhang Weiyu
  • Yeo Shunyi
  • Perrault Simon
  • Pei Jiaxin
  • Liddo Anna De
  • Veri Francesco
  • Flechtner Maurice
  • Saggion Horacio
  , 2026, pp.Article No.: 986, Pages 1 - 6. As societies grapple with increasing polarization and information complexity, the need for constructive, inclusive, and well-informed deliberation has reached an unparalleled level. At the same time, AI agents, ranging from LLMs and multi-agent simulations and systems to conversational assistants and reflective companions, are rapidly reshaping how people communicate, reason together, and form collective judgments. These technologies hold the potential to scale democratic participation, foster inclusivity by bridging linguistic and cultural barriers, and introduce new forms of collaborative reasoning. Yet they also pose epistemic challenges to established notions of authenticity, legitimacy, and human autonomy in civic dialogue. This panel brings together leading researchers from Asia, Europe and North America to examine how AI technologies are transforming deliberation as both a social process and a design problem. It interrogates AI's role in shaping deliberative norms, influencing group dynamics, and redefining what it means to "reason together" in hybrid human-AI spaces. Through interactive polling, structured debates, and audience co-deliberation, the session invites CHI participants to collectively explore how we can design responsible, inclusive, and trustworthy deliberation interfaces that preserve the democratic values of deliberation while embracing the creative potential of AI. (10.1145/3772363.3790075)
  DOI : 10.1145/3772363.3790075
• Synthetic Abundance Maps for Unsupervised Super-Resolution of Hyperspectral Remote Sensing Images
  
  • Xu Xinxin
  • Gousseau Yann
  • Kervazo Christophe
  • Ladjal Saïd
  IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, IEEE, 2026. Hyperspectral single image super-resolution (HS-SISR) aims to enhance the spatial resolution of hyperspectral images to fully exploit their spectral information. While considerable progress has been made in this field, most existing methods are supervised and require ground truth data for training—data that is often unavailable in practice. To overcome this limitation, we propose a novel unsupervised training framework for HS-SISR, based on synthetic abundance data, where no high-resolution ground-truth reference is required for training. The approach begins by unmixing the hyperspectral image into endmembers and abundances. A neural network is then trained to perform abundance super-resolution using synthetic abundances only. These synthetic abundance maps are generated from a dead leaves model whose characteristics are inherited from the low-resolution image to be super-resolved and from the known point spread function (PSF) of the hyperspectral sensor. This trained network is subsequently used to enhance the spatial resolution of the original image's abundances, and the final super-resolution hyperspectral image is reconstructed by combining them with the endmembers. Experimental results demonstrate both the training value of the synthetic data and the effectiveness of the proposed method across 3 datasets, 3 scaling factors, and several evaluation metrics. The code is available at https://github.com/xinxinxu99/SISR-DL.git
• Adaptive gradient domain normalization for one-sided unsupervised medical image synthesis
  
  • Paniagua Kévin
  • Conze Pierre-Henri
  • Jaouen Vincent
  • Angelini Elsa
  , 2026.
• Leveraging Whole Slide Difficulty in Multiple Instance Learning to Improve Prostate Cancer Grading
  
  • Arrivat Marie
  • Peyret Rémy
  • Angelini Elsa
  • Gori Pietro
  , 2026, pp.1-4. Multiple Instance Learning (MIL) has been widely applied in histopathology to classify Whole Slide Images (WSIs) with slide-level diagnoses. While the ground truth is established by expert pathologists, the slides can be difficult to diagnose for non-experts and lead to disagreements between the annotators. In this paper, we introduce the notion of Whole Slide Difficulty (WSD), based on the disagreement between an expert and a non-expert pathologist. We propose two different methods to leverage WSD, a multi-task approach and a weighted classification loss approach, and we apply them to Gleason grading of prostate cancer slides. Results show that integrating WSD during training consistently improves the classification performance across different feature encoders and MIL methods, particularly for higher Gleason grades (i.e., worse diagnosis). (10.1109/ISBI61048.2026.11515564)
  DOI : 10.1109/ISBI61048.2026.11515564
• Structure preserving adversarial diffusion for unpaired medical image synthesis
  
  • Paniagua Kévin
  • Conze Pierre-Henri
  • Jaouen Vincent
  • Angelini Elsa
  , 2026.
• Fast tomographic SAR inversion by unrolling a greedy algorithm for sparse reconstruction
  
  • Mendes Cristiano Ulondu
  • Denis Loïc
  • Kervazo Christophe
  • Tupin Florence
  , 2026. <div><p>As a range-based imaging technique, synthetic aperture radar (SAR) is agnostic to targets' elevation. In urban areas, tomographic synthetic aperture radar (TomoSAR) retrieves the position of sparsely distributed targets along the elevation direction thanks to the phase information from multiple acquisitions of the same area. Compressive sensing (CS)-based methods have received a lot of attention during the last decade, producing satisfactory reconstructions from a limited number of acquisitions. To improve their performance and scalability for pixel-wise TomoSAR inversion, data-driven methods based on the deep unrolling of basis pursuit algorithms have recently been proposed. However, they depend on a discretization of the elevation direction, often leading to artifacts which have to be corrected in a post-processing step. In this paper, we present an approach inspired by the iterations of a greedy algorithm for sparse reconstruction that estimates continuous elevation positions of targets together with well-calibrated uncertainty predictions. Our approach achieves performances comparable to reference CS-based methods while offering significantly faster processing. The trained models and the code used in the different experiments are available at place holder.</p></div>
• Automated Derivation of Formal Properties from Requirements
  
  • Sultan Bastien
  • Apvrille Ludovic
  • Saqui-Sannes Pierre De
  , 2026, pp.1-8. Early detection of design errors in the life cycle of systems is one of the many benefits one may expect from using an model-based systems engineering approach. The formal verification of models is thus an issue. Among verification techniques, the paper focuses on model checking. Taking as input a set of properties and a model, model checking outputs a “yes/no” answer for each property saying whether the property is verified or not. The relevance of this proof relies on the relevance of the defined properties. The paper proposes solutions for automated generation of properties from a SysML model and, more specifically, from the requirements expressed in the SysML model. We introduce an AI- and syntactic rule-based process that assists systems engineers in the generation of syntactically correct CTL properties, along with complementary contributions for computing and propagating requirement coverage from formal verification results, backtracing them directly in the SysML requirement diagram. The approach is mathematically defined, with explanatory comments accompanying the formalism to support comprehension. The proposed approach is further implemented by the free software TTool-AI. The latter is an open source SysML toolkit extended with an LLM-based assistant. A satellite system and an embedded maritime system serve as case studies. (10.1109/SysCon66367.2026.11503633)
  DOI : 10.1109/SysCon66367.2026.11503633
• Evaluating DV/CV-QKD Architectures for SAFE Long-Term Secure Storage: A Risk Model and ILP-Based Cost Optimization Approach
  
  • Tasdighi Alireza
  • Alléaume Romain
  , 2026, pp.1-9. This paper presents a unified cost model and optimization framework for evaluating hybrid discrete variable / continuous variable quantum key distribution (DV/CV-QKD) architectures within the SAFE (Secure and Efficient) longterm secure storage (LTSS) protocol. The proposed methodology jointly models the information-theoretic and computational aspects of storage security over extended time horizons and integrates a stochastic integer linear programming (ILP) formulation with a quantitative risk model. By combining Sample-Average Approximation (SAA) with an analytically tractable compromise probability, the framework identifies feasible and cost-optimal SAFE topologies under heterogeneous transmission budgets, keyrate constraints, and security tolerances. Simulation results over randomly generated metropolitan-scale deployments reveal how DV, CV, and multiplexed (MUX) QKD modalities are adaptively selected to minimize infrastructure cost while maintaining a target global compromise probability ϵ. The findings show that mixed DV/CV configurations—particularly when combined with multiplexing—achieve significant cost reductions compared to single-modality networks, paving the way towards the deployment of cost-efficient network infrastructures able to leverage existing QKD technology to provide practical cryptographic advantage for long-term secure storage. (10.1109/QCNC69040.2026.00029)
  DOI : 10.1109/QCNC69040.2026.00029
• Breaking exponential complexity in games of ordered preference: A tractable reformulation
  
  • Lee Dong Ho
  • Li Jingqi
  • Peters Lasse
  • Bakirtzis Georgios
  • Fridovich-Keil David
  , 2026. Games of ordered preference (GOOPs) model multi-player equilibrium problems in which each player maintains a distinct hierarchy of strictly prioritized objectives. Existing approaches solve GOOPs by deriving and enforcing the necessary optimality conditions that characterize lexicographically constrained Nash equilibria through a single-level reformulation. However, the number of primal and dual variables in the resulting KKT system grows exponentially with the number of preference levels, leading to severe scalability challenges. We derive a compact reformulation of these necessary conditions that preserves the essential primal stationarity structure across hierarchy levels, yielding a "reduced" KKT system whose size grows polynomially with both the number of players and the number of preference levels. The reduced system constitutes a relaxation of the complete KKT system, yet it remains a valid necessary condition for local GOOP equilibria. For GOOPs with quadratic objectives and linear constraints, we prove that the primal solution sets of the reduced and complete KKT systems coincide. More generally, for GOOPs with arbitrary (but smooth) nonlinear objectives and constraints, the reduced KKT conditions recover all local GOOP equilibria but may admit spurious non-equilibrium solutions. We introduce a second-order sufficient condition to certify when a candidate point corresponds to a local GOOP equilibrium. We also develop a primal-dual interior-point method for computing a local GOOP equilibrium with local quadratic convergence. The resulting framework enables scalable and efficient computation of GOOP equilibria beyond the tractable range of existing exponentially complex formulations.
• Importance Sampling Optimization with Laplace Principle
  
  • Dragomir Radu-Alexandru
  • Portier François
  • Priser Victor
  , 2026. Grid search and random search are widely used techniques for hyperparameter tuning in machine learning, especially when gradient information is unavailable. In these methods, a finite set of candidate configurations is evaluated, and the best-performing one is selected. We propose a simple and computationally inexpensive refinement of this paradigm: instead of selecting a single best point, we form a weighted average of the evaluated configurations, where the weights are chosen using an importance sampling scheme inspired by the Laplace principle. This scheme can be implemented as a post-processing step on top of a random search, with no additional function evaluations. We also propose an iterative variant, where the sampling distributions are chosen adaptively to generate new candidate points around the previous estimate, in the spirit of Evolution Strategy (ES) methods. In a general non-convex setting, we show that, after n evaluations, the error of the proposed methods is of smaller order than n -2/(d+2) . This compares favorably to random search or grid search rates of n -1/d as soon as d &gt; 2. We illustrate the practical benefits of this averaging strategy on several examples.