Systems and Control · Cross-listed from cs.NI
Can AI Agents Deliver Verifiable Network-Wide Outcomes Across Authority Boundaries?
Tianzhu Zhang, Chih-Kai Huang and Meikang Qiu
AI
agents are increasingly involved in network automation, where they can initiate configuration changes through mediated operational interfaces and assess the resulting state. Nonetheless, operational networks usually span many devices and administrative domains. Realizing an operator's intent requires coordinating
agents with distinct authority scopes that define the resources they can access, the operations they can invoke, and the network state they can observe. This division limits the blast radius of an erroneous action but fragments the evidence needed to assess the network-wide outcome. Successful execution of a configuration action proposed by one
agent does not establish that remote devices responded as intended or that routing changes reached the required devices. A valid observation may also become stale after a subsequent change. Before the coordinated operation can be declared complete, a trusted assurance layer must collect current observations from the required scopes and determine whether they collectively support the operator's intended network-wide outcome. To address the completion admission problem, we present EvidenceNet, a runtime assurance layer for deciding whether coordinated
agent operations have achieved an operator's network intent. Its broker collects the post-change observations required by a completion contract, and its admission gate checks that the evidence comes from the required scopes, remains current, and satisfies the task rules. A verifier
agent provides an additional assessment of the observation content. Experiments on live routing networks show that post-change state checks recognize successful outcomes that configuration-action records alone cannot establish. Controlled interventions further show that EvidenceNet rejects completion when otherwise satisfactory observations have the wrong source, have been substituted, or are stale.
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Signal Processing
Low-Complexity Maximum Likelihood Detection for Type-Based Over-the-Air Computation
Marc Martinez-Gost, Miguel Ángel Lagunas and Ana Pérez-Neira
Type-based multiple access (TBMA) is a digital over-the-air computation (OAC) scheme that exploits symbol collisions over the wireless multiple-access channel to construct a histogram of the transmitted data at the receiver. This paper addresses the optimal detection of the transmitted histogram in TBMA over an additive white Gaussian noise (AWGN) channel. Since the number of possible received histograms grows combinatorially with both the number of transmitters and the data alphabet size, maximum-likelihood (ML) detection renders computationally infeasible. We prove that the ML detection problem can be solved by a greedy
algorithm based on successive interference cancellation (SIC). We derive the analytical mean squared error (MSE) of the ML detector and show that it decreases exponentially with the SNR. Numerical results validate the theoretical analysis and demonstrate that TBMA achieves superior performance compared with conventional analog OAC, particularly for nonlinear functions.
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Systems and Control
Context operations to architecture modelling output from large language models and evaluation criteria for their use in systems engineering design
Vinicius Kaster Marini and Petter Krus
The development of generative artificial intelligence resources enables opportunities of speeding up systems and engineering design work. This contribution introduces a framework of formal operations for assembling context in LLM-based engineering design. This framework involves the assembly of modular context units, including policy
prompts, reference units with persistence, and user questions with
prompt vectoring. This approach enables the systematic structuring of interactions with generative models. A formal method for evaluating modelling-as-code LLM outputs is also presented, which enables the evaluation of compliance to intent from LLM answers and thereby asses the support from LLMs for systems architecture modelling.
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Signal Processing
Sequential Transmit Covariance Optimization for Wireless Tracking Exploiting Observation History
Kaiyue Hou and Shuowen Zhang
This paper studies a multiple-input multiple-output (
MIMO) radar tracking system, where a multi-
antenna base station (BS) aims to track the location of a moving target over multiple time slots based on the observed echo signals, initial prior probability density function (PDF) of the target state, and state
evolution model. By exploiting the realized observation history in the past time slots, the BS sequentially updates the predictive state information and designs the transmit covariance
matrix before collecting the current echo observation. Considering a Gaussian random-walk model for the target location and a Gauss-Markov model for the complex radar cross-section (RCS) coefficient, we propose an effective method to characterize the predictive PDF conditioned on the realized observation history via Gaussian approximation. Based on this, we derive the conditional posterior Fisher information
matrix (PFIM) for the target state, and further characterize the conditional posterior Cramér-Rao bound (PCRB) for the mean-squared error (MSE) in estimating the target's location state as an explicit expression of the transmit covariance
matrix. Next, we formulate the sequential transmit covariance
matrix optimization problem to minimize the conditional PCRB for each time slot. Despite the non-convexity of the problem, we obtain the optimal solution via the Schur complement technique. Numerical results show that the proposed design effectively exploits the realized observation history, achieves a lower conditional PCRB than the
benchmark schemes, and improves tracking accuracy over time.
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Image and Video Processing · Cross-listed from cs.LG
Storage-Scalable Progressive Semantic Communication via Knowledge-Base Reuse
Heng Zhu, Ye Liu, Kun Zhu et al. (+1 more)
Existing knowledge-base-assisted semantic communication schemes commonly adopt either single knowledge-base quantization (SKBQ) or multi-knowledge-base residual quantization (MKBQ). SKBQ incurs limited storage overhead but has restricted quantization capacity, whereas MKBQ supports progressive refinement by assigning an independent knowledge base (KB) to each stage, causing the KB storage to grow linearly with the transmission depth. To address this problem, we propose storage-scalable knowledge-base reuse quantization (SSKBQ), which reuses a compact set of KBs across multiple residual refinement stages and thereby decouples the number of transmission stages from the number of maintained KBs. A stage-aware residual supervision mechanism is further introduced to regularize intermediate quantized representations and encourage progressive refinement. Experimental results demonstrate that KB reuse provides an effective solution to the storage scalability problem while maintaining competitive progressive reconstruction performance.
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All authors Heng Zhu, Ye Liu, Kun Zhu, Feifei Song
Systems and Control · Cross-listed from cs.CE
Joint nonlinearity in a stiffened aluminium wingbox panel and what it requires of a reduced basis
Nikolaos D. Tantaroudas and Evangelos Papatheou
A shell finite-element model of a stiffened aluminium wingbox panel, a laboratory structure shared by several experimental studies, is built with its plate-to-stiffener joints at the $78$ physical fastener positions and calibrated against measured modal data, a six-parameter sensitivity update of the substructure moduli within $\pm20\%$ reproducing the first five measured modes to $1.1$–$4.3\%$ with modal-assurance values of $0.88$–$1.00$. Making the fasteners nonlinear, at equal mesh, mass and damping, shows that joint nonlinearity enters the response strongly asymmetrically. Hardening is almost invisible, at most $+1\%$ in frequency, whereas softening or slipping the joints moves the first three resonances by $-2.1$, $-4.9$ and $-9.2\%$, and friction removes up to $80\%$ of the resonant peak before it recovers. Newmark integration of all $18{,}804$ degrees of freedom and a harmonic balance condensed exactly onto the joints and continued in arclength agree to $5.5\times10^{-4}$. A projection-based nonlinear model order reduction then locates the criterion that a jointed structure imposes on a reduced basis. The binding quantity is not the linear response, which eleven vectors reproduce to better than $0.01\%$, but the receptance of the structure between the joints, of which $126$ global eigenvectors carry about $2\%$, and without which the reduced model overpredicts the hardening shift of the fundamental by a factor of thirty and returns a value beyond the rigid-joint limit of the panel.
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Image and Video Processing
Cost-Aware Vision–Language Model Arbitration for Fabric Structure Recognition A Deployable Multi-Agent System
Chenwei Wang, Haochen Li, Shuk Ching Tang et al. (+3 more)
Recognizing a fabric's structure is a prerequisite for translating textile-specific material information into structured digital form for downstream supply-chain systems. Pure CNN classifiers are cost-efficient but fail on visually ambiguous categories;
vision–
language models (VLMs) generalize more broadly but cost much more per image and are unstable on specialist domains. We present a multi-
agent system in which a CNN cascade handles the easy majority and a VLM is invoked only as a selective arbiter, constrained to a top-3 taxonomy-consistent choice. The fabric taxonomy performs as a constraint for the whole recognition process to increase the accuracy and reduce the VLM calls. Meanwhile, the CNN cascade is distilled to a small parameter size to reduce the inference time and meet the needs of practical deployment. On a newly curated 14-class
benchmark, a flat ConvNeXt-Tiny baseline reaches $90.45\,\%$ top-1 and $76.9\,\%$ on the four hardest classes; \method's hierarchical cascade reaches $93.94\,\%$ top-1 and $94.50\,\%$ hard ($+17.6$\,pp). Tightening the VLM trigger from $60\,\%$ to $<\!10\,\%$ cuts API cost by ${\sim}90\,\%$ with no measurable accuracy loss. CPU inference is $\le\!93$\,ms without a VLM call ($9.3$\,ms distilled). Each prediction carries a machine-readable
reasoning record, offered as an entry point for future supply-chain documentation.
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All authors Chenwei Wang, Haochen Li, Shuk Ching Tang, Misbah Iqbal, Carman Lee, Elif Ozden-Yenigun
Signal Processing · Cross-listed from quant-ph
Accelerating A*-Based Algorithms for Decoding Quantum Low-Density Parity-Check Codes
Lamia Yous, Francisco Garcia Herrero and Mark F. Flanagan
Quantum low-density parity-check (QLDPC) codes represent a promising approach for error correction in
quantum computing. The recently proposed Tesseract decoder uses the A* search
algorithm that guarantees finding the most likely error pattern. However, practical implementations of Tesseract often involve an extremely large graph, and the inherently sequential nature of the search results in high computational overhead and long runtime. To improve decoding efficiency, we propose a two-stage decoding framework. First, a belief propagation (BP) decoder efficiently processes the syndrome. This step generates hard decisions (a binary error vector) and soft information (per-
qubit confidence levels). In non-convergent BP cases, a gating mechanism examines the BP decoder's output to identify and filter out
qubits with oscillating confidence values. In these cases, the refined output serves as input to Tesseract, which then attempts to identify and correct any residual errors. This hybrid approach leverages the high speed of BP decoding and delegates the more challenging decoding instances to Tesseract. Numerical results demonstrate a substantial reduction in overall decoding complexity while maintaining the logical error rate (LER) of the stand-alone Tesseract. Across all tested physical error rates, the proposed method achieves at least 5x reduction in the number of expanded nodes in the Tesseract, with a peak reduction of nearly 15x at a physical error rate of p = 0.05 for the [[126, 12, d < 11]] T1 code, and approximately 8.8x at p = 0.05 for the [[72, 12, 6]] bicycle bivariate (BB) code.
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Audio and Speech Processing · Cross-listed from cs.SD
Orukeet: Multilingual ASR with Frozen Gabor Kernels
Nathan Roll, Irene Yi, Büşra Marşan et al. (+6 more)
Orukeet replaces half of an adapted Parakeet encoder's temporal filters with 12,288 fitted Gabor kernels, freezes these replacements, and trains the remaining parameters on multilingual and multi-accent data. Final adaptation and checkpoint selection use LibriSpeech test-other. Across 20,146 FLEURS recordings in 25
languages, pooled word error rate (WER) falls from Parakeet's 11.01% to Orukeet's 9.85%, a 10.6% relative reduction. Orukeet has lower WER on 23 of the 25
languages. Orukeet outperforms Parakeet on 61 out of 74 tested splits, including LibriSpeech test-clean (1.46% vs. 1.53% WER), test-other (2.86% vs. 3.14%), and FLEURS English (3.82% vs. 4.28%). All comparisons decode the same audio with matched NeMo settings. The fitted kernels are stored as ordinary convolution weights, retaining Parakeet's architecture and inference operators.
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All authors Nathan Roll, Irene Yi, Büşra Marşan, Vianney Grenez, Gabriel Stein, Momcilo Mrkaic, Pavle Padjin, Vladimir Zeljkovic, Calbert Graham
Audio and Speech Processing
SCNet: Enhancing GAN-based Speech Generation with Subband Condition Network and Magnitude-aware Phase Loss
Nan Xu and Mingxue Yang
Recent
speech generation has been predominantly driven by GAN-based networks aimed at high-quality waveform synthesis from mel-spectrograms. However, these methods often operate as black-box models, leading to the loss of inherent spectral information. In this work, we propose SCNet, a GAN-based vocoder augmented with a Subband Condition Network to address this issue. Specifically, SCNet leverages a subband signal predicted by a lightweight condition network as prior knowledge. This subband signal is then transformed via STFT to obtain
Fourier coefficients, which are integrated into the backbone for the enhanced reconstruction. Additionally, to mitigate the phase wrapping, we introduce a magnitude-aware phase loss that computes instantaneous phase errors weighted by the corresponding magnitude, emphasizing regions with higher energy. Experimental results demonstrate that SCNet achieves superior performance in both objective and subjective evaluations for high-quality
speech generation.
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Systems and Control · Cross-listed from cs.CV
Elastoformer: Enabling Dynamic Adaptivity via Elastic Model Transformation
Sudaksh Kalra and Dolly Sapra
EdgeAI systems are increasingly employing computer
vision applications to enable intelligent, on-device decision-making in real-time. However, these deployments face highly dynamic operational conditions, with fluctuating constraints on latency, power availability, and
memory resources. Deep Neural Networks (DNN), which follow fixed computational execution flows, lack the flexibility to adapt to such variability, resulting in inefficient and suboptimal performance in edge scenarios. This underscores the need for architectures that are not only efficient but also dynamically scalable at runtime. In this paper, we propose Elastoformer: A framework that transforms conventional neural networks (NN) into Elastic NN capable of real-time elastic inference. Unlike the conventional bag-of-models approach, which requires maintaining multiple independent models for different operating conditions, Elastoformer offers a single, modular solution that dynamically switches between multiple modes of operation at runtime, adapting efficiently to the changing computational budgets of edge devices without the overhead of managing separate models. Experiments reveal that our framework achieves up to 85% reduction in computation FLOPs, 50% reduction in latency and 76% reduction in
memory overhead, while showcasing the architecture agnostic nature of the framework across both
Vision Transformers and CNNs. Our code is available at https://github.com/sudaksh14/Elastoformer.
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Systems and Control
Review on State-of-the-art Energy Systems in the Arctic
Bilal Babar and Sabrina Sartori
The Arctic regions remain heavily dependent on fossil fuels for energy generation. At the same time, the Arctic is warming at a rate considerably faster than the global average, increasing the need for low-carbon and
climate-resilient energy systems. This review documents the current energy systems and assesses state-of-the-art energy solutions applicable to Arctic and cold-
climate regions, as well as the future direction of these emerging energy systems, and analyses the role of energy storage, heating requirements, and advanced energy solutions. A total of 88 research articles were systematically reviewed. The reviewed studies indicate the potential for wind and solar to reduce dependence on fossil-fuel based energy generation. For energy storage, the reviewed solutions include hydrogen for long-term storage, battery-based system for short-term storage and regulation, and thermal storage using boreholes to meet heating demand. Where a fully renewable system cannot provide the required reliability, diesel can serve as back up generation. Some barriers to widespread adoption are technological, such as the need for specialized planning tools and equipment resilient to harsh weather, and social and institutional, such as the need for governmental support, subsidies, and appropriate legal frameworks.
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Audio and Speech Processing
Over-Tightening-Aware Pseudo-Labeling for Tight-Boundary Speaker Diarization
Shota Horiguchi, Takanori Ashihara, Marc Delcroix et al. (+2 more)
Training speaker diarization models on loose labels, such as
speech segments with padded boundaries or filled pauses, often results in similarly loose model outputs. To obtain tighter boundaries, pseudo-labeling based on the averaged outputs of causal and anticausal models has been proposed. However, since the pseudo-labels are estimation-based, they can suffer from over-tightening, which increases missed detections that can propagate as unrecoverable errors to downstream tasks. This paper carefully analyzes the causes of over-tightening and proposes three approaches to address them: (i) removing pause filling rather than padding, (ii) introducing a burn-in phase to mitigate missed detections near the beginning of causal and anticausal predictions, and (iii) making pseudo-label-based co-training aware of the non-causal model used for final inference. Experimental results show that the proposed method reduces missed detections caused by over-tightening and improves both diarization accuracy and downstream multi-talker ASR performance.
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All authors Shota Horiguchi, Takanori Ashihara, Marc Delcroix, Naohiro Tawara, Alexis Plaquet
Audio and Speech Processing
SpeechAnnotator: A Context-Aware Multi-Agent Framework and Benchmark for Multidimensional Speech Annotation
Qirui Zhan, Shuiyuan Wang, Jingbin Hu et al. (+10 more)
Recent controllable
speech generation requires training data with fine-grained annotations of speaker traits, prosody, emotion, paralinguistic cues, acoustic scenes, and context. Existing workflows often rely on manual correction, paid hosted
multimodal services, or fixed processing chains, which limits large-scale data processing through annotation cost, external-service dependence, or weak cross-stage recovery. We introduce SpeechAnnotator, a locally deployable, context-aware multi-
agent framework built entirely from open-source models and tools. Supporting frontend modules first obtain speaker-aware segments and final segment transcripts, while prior evidence extractors attach heterogeneous segment-level cues. Three specialist
agents then collaborate through shared state: the Planning
Agent converts local audio evidence, speaker history, neighboring segments, and recording-level context into field-specific contracts; the Labeling
Agent performs contract-guided
multimodal prediction for directly observable attributes; and the Review
Agent runs a bounded review loop that checks evidence support and cross-segment consistency, triggering relabeling only for unsupported or inconsistent fields. To address the fragmentation of existing evaluation resources across isolated tasks and narrow-domain test sets, we introduce SpeechAnnotator-Bench (SA-Bench), containing 8.87 hours of human-annotated audio across nine source formats, together with SpeechAnnotator-Eval (SA-Eval), which separates Timeline-Eval for speaker-aware timeline recovery, Closed-Eval for finite-set attributes, and Open-Eval for open-ended attributes. Experiments and ablations show that SpeechAnnotator provides a locally deployable alternative to commercial audio-capable systems, while the bounded review loop improves multidimensional annotation through evidence- and context-aware field-level recovery.
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All authors Qirui Zhan, Shuiyuan Wang, Jingbin Hu, Haoyu Zhang, Xiaming Ren, Jinrui Liang, Chaoren Yu, Bengu Wu, Yunxiang Chen, Houdun Liu, Su Feng, Liumeng Xue, Lei Xie
Audio and Speech Processing
NVV-Locator: From Transcript Tags to Acoustic Boundaries for Fine-Grained Nonverbal Vocalization Grounding
Yuang Cao, Bingshen Mu, Zhennan Lin et al. (+7 more)
Human
speech includes nonverbal vocalizations (NVVs), such as laughter, sighs, breaths, and coughs, which convey affective and interactional information. Existing approaches typically represent NVVs as transcript-level tags, providing limited supervision for their waveform-time boundaries. We present NVV-Locator for fine-grained NVV temporal grounding. We first unify 26 NVV categories across public resources and construct large-scale timestamp-supervised training data through dual-LLM verification, transcript-guided forced
alignment, and energy-based boundary refinement. We further introduce NVV-TimeBench, an expert-refined
benchmark with 667 utterances and 1,094 events. NVV-Locator uses a non-autoregressive slot-filling architecture to jointly predict lexical timestamps, NVV categories, and event boundaries. On NVV-TimeBench, it achieves 71.0% Micro F1, 70.2% Macro F1, 80.4% Macro mIoU, and 59.6 ms Macro mMAE, outperforming the evaluated large audio model counterparts. Evaluation on an external corpus further demonstrates the cross-corpus generalization of NVV-Locator.
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All authors Yuang Cao, Bingshen Mu, Zhennan Lin, Guojian Li, Haoyue Zhan, Jie Liu, Chuan Xie, Qiang Zhang, Liumeng Xue, Lei Xie
Systems and Control · Cross-listed from math.OC
The Global Asymptotic Stability Problem for Linear MPC Is Undecidable
Johan Löfberg
We prove that deciding global asymptotic stability for constrained finite-horizon linear model predictive control is undecidable. This holds at horizon one with identity state, input, and terminal weights, unique optimizers, and global feasibility. Separate reductions cover predicted-state boxes, hard input boxes, and quadratically softened input boxes. A fourth reduction fixes the state and input dimensions to three and six. Hence undecidability is not caused by long horizons, growing dimensions, failures of recursive feasibility, or nonuniqueness.
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Audio and Speech Processing
Source-Adaptive Data Curation for Bilingual NVV-Aware ASR
Yuang Cao, Qirui Zhan, Jingbin Hu et al. (+7 more)
Nonverbal vocalizations (NVVs), such as laughter, sighs, breaths, and coughs, convey affective and interactional information that conventional automatic
speech recognition (ASR) systems often discard. We present a bilingual Mandarin-English system for Track 1 of the NVVSpeech Challenge at ISCSLP 2026, which requires joint transcription of lexical content and 16 NVV categories at their transcript-relative positions. Our NVV-Aware Whisper adapts Whisper-medium through checkpoint-compatible vocabulary remapping, enabling lexical
tokens and inline NVV tags to be decoded within a unified autoregressive sequence without expanding the vocabulary. To provide reliable and diverse supervision, we further introduce a source-adaptive data curation strategy that refines public NVV corpora through acoustic augmentation and
multimodal LLM filtering, while mining spontaneous NVVs from in-the-wild media through automated preprocessing and annotation. Under the official bilingual evaluation protocol, the proposed system improves final score from 33.32 to 53.61, with ablations confirming the complementary benefits of the proposed data-curation components.
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All authors Yuang Cao, Qirui Zhan, Jingbin Hu, Ziyu Zhang, Yunxiang Chen, Houdun Liu, Su Feng, Bengu Wu, Lei Xie, Liumeng Xue
Audio and Speech Processing
SphereVAE: Hyperspherical Latent Autoencoders for Robust Autoregressive Speech Representation Modeling
Haoyu Zhang, Jingbin Hu, Hanke Xie et al. (+8 more)
With the rapid development of
speech generation technology, discrete codec representations have been widely used because they provide a stable prediction paradigm. In expressive
speech generation, however, the quantization bottleneck of discrete codecs results in information gaps in fine-grained prosody, timbre, pronunciation, and frame-to-frame continuity. Continuous representations (e.g., VAE latents), by eliminating this constraint, have emerged as a more effective alternative for autoregressive modeling. Yet when continuous representations are used as autoregressive prediction targets, prediction errors can accumulate along the generation chain, causing latent drift and degrading long-form stability. To mitigate this problem, we propose SphereVAE, which constrains the VAE latent space to the unit hypersphere. SphereVAE defines a Power Spherical posterior on the hypersphere and regularizes the latent distribution toward a uniform prior, so that information is encoded mainly by directional variation, providing a bounded
geometric target for autoregressive prediction and reducing the risk of norm drift. SphereVAE underperforms the standard VAE on reconstruction metrics due to reduced latent freedom. However, when integrated into VoxCPM for zero-shot TTS and long-text generation, it yields lower content error rates with comparable speaker similarity, and shows more stable long-range speaker consistency. These results indicate that an appropriate latent
geometric constraint can effectively mitigate autoregressive error accumulation and drift in
speech generation.
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All authors Haoyu Zhang, Jingbin Hu, Hanke Xie, Qirui Zhan, Wenhao Li, Ziyu Zhang, Xiaming Ren, Yue Li, Xunyu Zhu, Zhipeng Chen, Lei Xie
Systems and Control
Optimal Dispatch of a Hydrogen-Colocated Renewable-Powered Desalination Plant
Guochen Zhao and Ahmed S. Alahmed
This paper develops an analytical framework for profit-maximizing dispatch of water, electricity, and green hydrogen in a renewable-powered water desalination plant (WDP) combining thermal and reverse osmosis (RO) desalination. The optimal dispatch reveals that the schedules of the desalination units, electrolyzer, and grid interaction can all be characterized in closed form as functions of renewable generation. At low renewable output, the plant relies on thermal desalination and grid power while maintaining RO desalination and hydrogen production at their minimum setpoints. At high output, it reduces thermal desalination, increases RO desalination, and allocates surplus power and water to hydrogen production. For renewable output within a precomputed intermediate range, the WDP balances energy internally, allocating resources based on the relative marginal values of hydrogen and RO water. Simulations using real solar and plant data show that integrating RO and thermal desalination with renewable generation and hydrogen production achieves the highest daily profit of 75.945 k$, exceeding the best configuration without hydrogen by 15.1%.
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Audio and Speech Processing
UniStream: Multi-Expert Residual Vector Quantization for 48 kHz Causal Streaming Audio Coding
Mingyu Zhao and Zhiyong Wu
We present UniStream, a fully causal 48 kHz neural audio codec for streaming
speech, music, and environmental sounds. At its core is Multi-Expert Residual Vector Quantization (ME-RVQ), which replaces the single shared codebook in each residual quantization layer with four expert codebooks controlled by a deterministic Top-K router. Because routing decisions are derived solely from previously decoded quantized states, the decoder can reproduce the selected experts without transmitting expert identifiers, thereby expanding quantization capacity while adding 5.5M parameters. We further introduce an auxiliary Optimal Transport Conditional Flow Matching (OT-CFM) objective to regularize the quantized latent space during training. The flow module is removed entirely at inference and therefore incurs no runtime overhead. UniStream supports a 12 kbps Top-1 mode and a 22.5 kbps Top-2 mode within a causal 48 kHz encoder-decoder framework, while achieving real-time GPU inference. To complement narrow-band
speech metrics, we report 48 kHz ViSQOL audio mode, ViSQOL
speech mode, standard VGGish-FAD, DNSMOS P.835, and higher-rate reference comparisons with Opus and EnCodec. At 12 kbps, UniStream-Top1 achieves PESQ and UTMOS scores comparable to EnCodec while reducing
speech Mel-D from 13.07 to 8.21. At 22.5 kbps, UniStream-Top2 achieves a ViSQOL
speech-mode score of 4.67 and an environmental audio-mode score of 3.96, exceeding all evaluated systems operating at 12 kbps or below in the latter setting. It also comes within 0.03 MOS-LQO of Opus at 24 kbps on
speech in ViSQOL audio mode. Ablation studies confirm that ME-RVQ is the primary source of quality improvement, whereas OT-CFM provides perceptual gains on
speech with a mild trade-off in spectral distortion.
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Systems and Control · Cross-listed from cs.NI
Can AI Agents Detect and Repair Artifact Drift in Network Experiments?
Tianzhu Zhang, Weichen Tao, Changgang Zheng et al. (+4 more)
In recent years, AI
agents have evolved into capable assistants that carry out multi-step tasks in digital environments. The network systems community is beginning to explore these capabilities in operational and experimental settings. However, an
agent operating in network systems should not be judged solely by whether it completes the immediate task. The experiment record it modifies must also remain trustworthy. We call this property artifact integrity: the record's claims must remain supported by the available evidence, confined to the scope established by that evidence, and traceable through the artifacts that encode their support. To make this property measurable, we introduce NetArtifactBench, which tests whether AI
agents can repair inconsistent records derived from public network-system artifacts while preserving claims that remain supported. The
benchmark contains 52 instances with injected inconsistencies ranging from direct contradictions to unstated relations spread across several artifacts. We evaluate 23
agent configurations across three general-purpose AI
agent runtimes using deterministic scoring. The average contract pass rate is 65.3 % across 5,980 outputs, but no
agent runtime exceeds 30 % when repair requires recovering implicit relations and propagating changes across artifacts. These results reveal a sharp boundary between local correction and complete record-level repair. Therefore, we argue that artifact integrity should become a first-class design and evaluation requirement for AI
agents operating on network systems.
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All authors Tianzhu Zhang, Weichen Tao, Changgang Zheng, Yusheng Zheng, Long Chen, Xiaoyi Fan, Meikang Qiu
Systems and Control
Semi-Cooperative Passive Integrated Sensing and Communication by Utilizing Physical Layer Information of 5G Signals
Bo Wei, Ryusei Ogane and Hang Song
In recent years, integrated sensing and communication (
ISAC) has attracted significant
attention towards future cellular networks. Currently, various works have demonstrated sensing performance in existing wireless communication systems. Most of the demonstrations are based on passive type due to the
radio regulatory. However, because of the difficulty in access to the communication protocol stacks in commercial cellular systems, the evaluation of the cellular communication signals for semi-cooperative passive
ISAC is limited. In this paper, a semi-cooperative passive
ISAC system is developed with open-source 5G framework and software-defined
radio devices. And the performance is experimentally evaluated by utilizing the physical layer information of actual 5G signals from the developed system. In this system, communication is established with 5G signals and physical layer information are obtained and extracted for analysis. The performance of the system is verified by conducting experiments under several communication scenarios including the synchronization, pinging, and data transmission. Different physical layer information is collected, and the propagation characteristics are analyzed by a multi-path configuration. The experiment results demonstrated that variable bandwidths were utilized for different communication scenarios and the multipath was successfully detected with two different approaches. These results show that the developed system is promising for semi-cooperative passive
ISAC in wider application fields
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Systems and Control
Entropy-Regularized Optimal Transport for Time-Varying Multi-Agent Coverage Control
Italo Napolitano and Mario di Bernardo
This paper addresses time-varying coverage control for multi-
agent systems, formulated as the tracking of an evolving target density via
entropy-regularized semi-discrete optimal transport. Unlike the hard Laguerre partition of the unregularized formulation, entropic regularization assigns fractions of the mass at each point to all
agents, simplifying the design and numerical implementation of the control law. We derive a feedback-feedforward controller that tracks the evolving first-order optimality conditions with exponential convergence, and we investigate the role of the regularization parameter, which, above a critical threshold, renders the fully collapsed configuration locally optimal. Numerical experiments validate the theory: for moderate regularization, the proposed approach has performance comparable to the unregularized formulation and outperforms the corresponding Voronoi-based coverage baseline.
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Image and Video Processing
Morphological Decoupling-Based Skeletal Classification for Clinical Assessment of Malocclusion
Zhichun Jin, Zhicheng He, Hao Xu et al. (+4 more)
Malocclusion skeletal grading is a fundamental task in orthodontics, critical for diagnosis and treatment planning. Traditionally, cone-beam computed
tomography (CBCT) is used for visual measurement, and the reconstructed lateral cephalograms are handed over to expert dentists for diagnosis. However, manual review is time-consuming, labor-intensive, and subject to inter-operator variability. Therefore, an automatic CBCT-based system is needed for reliable malocclusion skeletal grading. In this case, we develop TeethGNN, a novel graph-based framework designed to combine CBCT image features with morphological information for accurate and efficient malocclusion grading. TeethGNN utilizes a decoupled learnable decoder to directly predict key morphological indicators from CBCT images, eliminating the need for manual measurements. These morphological features are then fused with image features using a graph neural network (GNN), which effectively models the relationships between the modalities. To further enhance robustness and calibration, we introduce a collaborative calibration strategy. This strategy combines multi-scale graph
adversarial perturbation for explicit calibration and nonlinear topological graph calibration for implicit confidence adjustment. Extensive experiments and ablation studies on our collected clinical
dataset demonstrate that our malocclusion measurement system achieves 77.08% in accuracy and 89.61% in AUC, outperforming the compared state-of-the-art methods. These results validate the effectiveness of graph-based
multimodal fusion and collaborative calibration in improving malocclusion grading performance. Our system shows strong potential for advancing computer-aided orthodontic diagnosis, providing an accurate and reliable solution for
vision-based clinical measurement and diagnosis.
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All authors Zhichun Jin, Zhicheng He, Hao Xu, Dongyang Li, Lin Wang, Hongliang Ren, Long Bai
Systems and Control
Spatial LLM Workload Shifting Needs Foresight: Model Commitment for AI Data Center Operation under Power Grid Constraints
Bojun Du, Hongyang Jia, Tonghui Li et al. (+4 more)
AI data centers may face power supply shortages during certain periods, requiring operators to shift large
language model (LLM) inference workloads spatially to maintain service rates. However, existing workload-shifting methods typically assume that any data center with sufficient computing resources can immediately serve shifted requests, which may lead to infeasible transfers and unserved demand. This letter proposes model commitment (MC), a mixed-integer linear programming framework that jointly schedules model deployment and cross-site request routing under power constraints and electricity-price signals. First, MC formulates the intertemporal coupling introduced by model replica loading. Second, it translates prefill and decode latency requirements into the amount of demand that each replica can serve. Case studies based on real-world data show that MC enables AI data center operators to achieve a 100% service rate under time-varying grid conditions and reduce total operating cost by 29.0%.
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All authors Bojun Du, Hongyang Jia, Tonghui Li, Qingchun Hou, Ze Wang, Ershun Du, Ning Zhang
Signal Processing
Cooperative LEO-Terrestrial Multistatic ISAC: CRLB Analysis, Scaling Laws, and Satellite Selection
Yunhui Li, Kaitao Meng, Emad Alsusa et al. (+1 more)
Low Earth orbit (LEO) satellites provide elevated and spatially diverse viewpoints for enhancing three-dimensional (3-D) sensing in integrated satellite-terrestrial networks (ISTNs). This paper investigates a LEO-assisted terrestrial multistatic integrated sensing and communication (
ISAC) network for 3-D target localisation, where multiple LEO satellites act as cooperative sensing illuminators and provide additional bistatic observations to distributed terrestrial radar receivers. We first model cooperative satellites as a homogeneous Poisson point process (PPP) and derive a tractable approximation of the average hybrid Cramér-Rao lower bound (CRLB). The resulting scaling laws show that the root-CRLB decreases with the inverse square root of the mean number of cooperative satellites for a fixed cooperation region, while increasing the cooperation radius at fixed satellite density yields logarithmic diminishing returns. We then develop an Earth-
curvature-aware Walker model incorporating orbital structure, satellite motion, visibility, and time-varying sensing geometry, and derive a tractable approximation of the corresponding hybrid CRLB. Analytical bounds on the marginal gain and a sufficient condition for ordering candidate satellites are obtained. Based on these results, a CRLB-oriented greedy satellite-selection strategy is proposed to account for SCNR-dependent reliability and
geometric complementarity with the terrestrial sensing configuration. The proposed strategy consistently outperforms
benchmarks and approaches exhaustive-search performance with substantially lower complexity. Monte Carlo simulations validate the analytical approximations for both models.
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All authors Yunhui Li, Kaitao Meng, Emad Alsusa, Kaiting You
Signal Processing
Multi-Stream Spatiotemporal Channel Coding for MIMO Systems: Transmission Scheme Design and Achievable Rate Optimization
Liang Jin, Xiaodong Xu, Shujun Han et al. (+3 more)
Spatiotemporal channel coding (STCC) can improve the achievable rate over traditional temporal channel coding (TCC) by leveraging spatial degrees of freedom to extend the codeword length. Although several information-theoretic foundations on STCC have been established, the investigation of transmission schemes from a communication-theoretic perspective remains in its early stages. This paper proposes a multi-stream over multi-subchannel STCC (STCC-MSC) under full channel state information assumption and optimizes its achievable rate in the finite blocklength regime. We first formulate the transmission architecture of STCC-MSC in a point-to-point
MIMO system, which introduces a stream-subchannel matching mechanism. We then maximize the achievable rate of STCC-MSC by jointly optimizing the subchannel assignment and power allocation strategies, which is formulated as a mixed-integer-nonlinear-programming problem. Next, a penalized alternating convex approximation (PACA)
algorithm is proposed to solve this problem. Subsequently, we extend the point-to-point STCC-MSC designs to the more general multi-user
MIMO systems, including both uplink and downlink scenarios. Finally, simulation results indicate that the PACA
algorithm achieves a 9.85% rate improvement over the
benchmark algorithm within the STCC-MSC scheme. Furthermore, the joint STCC-MSC-PACA scheme improves the achievable rate by 28.68% over TCC scheme.
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All authors Liang Jin, Xiaodong Xu, Shujun Han, Xiaoyu Chi, Ping Zhang, Chau Yuen
Signal Processing
A Fully Wave-Domain Wideband MU MIMO OFDM Transmitter via Stacked Intelligent Metasurfaces
Zheao Li, Jiancheng An and Chau Yuen
This paper proposes an advanced realization principle for wideband multiuser multiple-input multiple-output orthogonal frequency-division multiplexing (MU-
MIMO OFDM) transmitters, where the conventional transmitter-side baseband chain is physically synthesized in the wave domain. For design and optimization purposes, this fully wave-domain wideband MU-
MIMO OFDM transmitter implemented by a cascaded SIM structure is functionally partitioned into two cascaded SIM blocks. The first block, denoted as SIM_1, integrates symbol loading and channel-adaptive MU-
MIMO precoding updated at the channel-coherence timescale, mapping the user streams to a virtual port-subcarrier representation. The second block, denoted as SIM_2, acts as an offline-configured sampling-rate modulator that materializes the inverse discrete
Fourier transform (IDFT) and cyclic prefix (CP) insertion directly in the wave domain. This baseband-free architecture establishes a virtual-to-physical transition from information bits to radiated CP-extended OFDM waveforms. To account for practical nonidealities, SIM_2 is optimized to fit the ideal multi-port CP-OFDM operator, and its residual response is mapped into an effective coupling
matrix. Then, SIM_1 is optimized in a communication-oriented manner by jointly adapting discrete phase shifts and stream-subcarrier power loading to maximize the sum spectral efficiency. Results demonstrate the convergence, architecture trade-off, wave-domain OFDM materialization accuracy, and competitive performance of the proposed baseband-free transmitter.
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Audio and Speech Processing · Cross-listed from cs.CL
StreamAlign: Streaming Text-Aligned Speech Tokenization
Kang-wook Kim, Jinyoung Park, Jinsoo Kim et al. (+3 more)
Text-aligned
speech tokenization methods have emerged to better align
speech tokens with LLM
token spaces, enabling more effective utilization of pretrained LLMs. However, they rely on offline automatic
speech recognition (ASR), leading to two key limitations: (i) the need for complete utterances before tokenization, precluding real-time streaming, and (ii) vocabulary mismatch between ASR and LLMs, which reduces acoustic granularity from the subword to the word level. We introduce StreamAlign, a text-aligned
speech tokenization framework that enables streaming tokenization for real-time
speech-text joint modeling. StreamAlign performs online
speech-text
alignment by combining character-level RNN-Transducer
alignment with word-level ASR guidance, mitigating ASR-LLM vocabulary mismatch while preserving recognition accuracy. A proactive word boundary classifier anticipates word completion at chunk boundaries, reducing tokenization latency from 560 ms to 270 ms. On LibriSpeech, StreamAlign achieves the lowest WER and highest UTMOS among evaluated tokenizers. Furthermore, StreamAlign-SLM, a spoken
language model trained on StreamAlign units, outperforms other end-to-end spoken
language models in
speech continuation while achieving the strongest overall consistency on SALMon and spoken StoryCloze.
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All authors Kang-wook Kim, Jinyoung Park, Jinsoo Kim, Sehun Lee, Sang Hoon Woo, Gunhee Kim
Signal Processing
Efficient Graph Neural Networks for Multicarrier Wideband Hybrid Beamforming Optimization
Beier Li and Mai Vu
6G wireless technology is poised to adopt higher and wider frequency bands, leveraging highly directional beamforming. However, the vast bandwidths amplify the impact of beam squinting. Traditional solutions, such as adding a true-time-delay filter to each
antenna, are cost-prohibitive due to the required hardware scale. This paper proposes a signal processing alternative using Graph Neural Networks (GNNs) to optimize hybrid beamforming in multicarrier wideband systems. Using a bipartite graph to represent a shared analog beamformer among multiple subcarriers, we develop three GNN structures with distinct digital beamformer representations (i) at the subcarrier nodes, (ii) at the edges, or (iii) integrating traditional singular-value decomposition solutions. By designing an efficient message-passing mechanism, these structures offer insights into the impact of different GNN designs on communication system performance and computational complexity. Extensive analysis and ablation studies show that our proposed GNN structures outperform traditional optimization methods and existing ML-based solutions. Furthermore, the proposed GNNs exhibit strong resiliency to beam squinting and better robustness against imperfect CSI than even fully digital beamforming and all existing hybrid designs. These GNNs can also be extended to multi-user scenarios and demonstrate excellent generalization capabilities, allowing trained models to adapt to diverse multicarrier and multi-user settings without retraining.
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