Systems and Control · Cross-listed from math.DS
Analysis of a Stochastic Energy Supply and Demand Model with Renewable Integration
S.O.Edeki, S.Noeiaghdam, L. Hairong et al. (+2 more)
In this work, a
stochastic energy supply-demand model with renewable integration is developed and analyzed. The basic nonlinear deterministic model describing the relationship among regional demand, external supply, energy imports, and renewable resource integration is extended to an Ito-type
stochastic system that captures the uncertainties due to
market volatility, climatic variation, policy interventions, and technical changes. Also, the noise structure is multiplicative, ensuring proportional fluctuations and preservation of nonnegativity of the state variables. Global existence, uniqueness of positive solutions, moment boundedness, and
stochastic persistence are established rigorously. Furthermore, the deterministic system is analyzed, and
stochastic stability is examined using
matrix inequality criteria to guarantee almost sure exponential stability of the system in the
stochastic setting. Among other results,
stochastic perturbations significantly alter the effective system capacity compared to the deterministic case; however, under suitable parameter conditions, boundedness and stability cases are preserved. The Euler-Maruyama scheme is employed to perform numerical simulations to illustrate various dynamical behaviors and highlight the effects of uncertainty on system dynamics.The numerical reliability of the proposed model is further confirmed by additional numerical experiments via the Milstein scheme and parameter sensitivity analysis. Moreover, the results indicate that
stochastic effects should be considered for capturing complex energy systems' behavior under uncertainty and its implications for renewable integration.
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All authors S.O.Edeki, S.Noeiaghdam, L. Hairong, S. Kaennakham, I. D. Ezekiel
Signal Processing · Cross-listed from cs.IT
Spectral-Domain Spreading via Hadamard Transform for Robust Downlink Non-Orthogonal Multiple Access
Yaakoub Berrouche and Theodoros A. Tsiftsis
Non-orthogonal multiple access (NOMA) systems allowing multiple users sharing the same resource block offer significant gains in spectral efficiency which can enable the required massive access in future wireless systems. However, they face several challenges due to their sensitivity to power allocation coefficients, fading effects, and imperfect channel state information (CSI). To address these limitations, this paper proposes Hadamard-NOMA, an approach leveraging the Hadamard Transform (HT) at the source level prior to modulation. By introducing HT, the system mitigates the adverse impact of fading and CSI imperfections, reducing bit error rates (BER) and enhancing overall system reliability. Theoretical analysis and Monte Carlo simulations validate the effectiveness of this technique, demonstrating robust NOMA transmission in dynamic wireless environments. The proposed method offers a promising solution for next-generation wireless networks, ensuring more reliable performance under diverse transmission conditions. Simulation results confirm analytical predictions, demonstrating significant performance improvements over state-of-the-art T-NOMA and Usman-NOMA schemes. Specifically, for the Near user, a gain of 15 dB is achieved at a Bit Error Rate (BER) of $10^{-2}$, while the Far user benefits from a 10 dB gain at a BER of $10^{-1}$. Compared to Usman-NOMA, the proposed method provides an improvement of 15 dB for the Far user at BER $10^{-1}$. Additionally, in a two-user scenario with imperfect Successive Interference Cancelation (SIC), user 1 requires an SNR at least 14 dB lower than user 2 to achieve a BER of $10^{-3}$. These findings highlight the effectiveness of applying HT at the source stage, significantly mitigating CSI errors and making NOMA more resilient for next-generation wireless networks.
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Systems and Control
A Novel Phase-Noise Module for the QUCS Circuit Simulator. Part II : Noise Analysis
Torsten Djurhuus and Viktor Krozer
The paper documents the implementation of a novel phase-noise analysis module within the open-source QUCS
circuit simulator environment. The underlying
algorithm is based on a rigorous, unified time-domain methodology of (coupled) oscillator noise-response, recently proposed by the authors. The theoretical approach used to develop this model is entirely unconstrained by any empirical and/or phenomenological modelling techniques, such as e.g. LTI and LTV theory, and this differentiates it from all prior proposals on this topic. The paper introduces important, and previously unpublished, extensions to this framework, in the form of novel unified closed-form expressions for both the amplitude and phase-amplitude correlation response of a general coupled oscillating
circuit perturbed by noise. The research discussed herein has many important scientific and industrial applications w.r.t. predicting, synthesizing and optimizing the performance of noise-perturbed free-running and coupled autonomous
circuits operating under large-signal steady-state conditions. These timing
circuits are ubiquitous in all modern communication and remote-sensing systems and the developed simulation tools will prove to have great impact in various areas of industrial
circuit design. This paper represents second part of a two-part series with the first part discussing the implementation of the underlying steady-state analysis module. The open-source simulator, discussed and developed herein, applies advanced state-of-the-art
stochastic modelling techniques, in-order to produce noise simulation tools with capabilities and scope which, in many areas, exceed what is found in the commercial EDAs currently on the
market.
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Systems and Control
Leveraging Quantum Annealing for Large-Scale Household Energy Scheduling with Hydrogen Storage
Arash Khalatbarisoltani, Amin Mahmoudi, Jie Han et al. (+6 more)
Hydrogen integration into microgrids facilitates the absorption of intermittencies from renewable energy resources. However, significant challenges remain due to complex optimization problems, particularly in large-scale applications involving multiple fuel
cells (FCs) and electrolyzers (ELs) with numerous binary decision variables. This paper presents a hierarchical
quantum annealing (QA) model predictive control-based power allocation framework aimed at accelerating these optimization problems. First, in a day-ahead stage, the framework determines the startup and shutdown of the FCs and ELs. The short-term stage then refines the output power of the FCs and the hydrogen generation rate of the ELs. The feasibility is evaluated through a case study consisting of multiple households in Australia. Our findings demonstrate that while the traditional optimization approach performs satisfactorily in scenarios with a small number of households, the QA approach becomes more appropriate and effectively solves the problem within an acceptable range as the number of connected households increases.
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All authors Arash Khalatbarisoltani, Amin Mahmoudi, Jie Han, Muhammad Saeed, Wenxue Liu, Jinwen Li, Solmaz Kahourzade, Amirmehdi Yazdani, Xiaosong Hu
Systems and Control
A Curved Monopole Antenna for HF Radar with Enhanced Gain and Bandwidth
Masoud Salmani Arani, Reza Shahidi and Lihong Zhang
This paper presents the design and simulation of a new curved monopole
antenna optimized for skywave HF radar applications, with a systematic investigation of the effects of
curvature and fixed-section length on
antenna performance. The proposed design achieves improved impedance matching, broader bandwidth, and enhanced realized gain compared to a conventional quarter-wavelength monopole at 15 MHz. Parametric analysis shows that fully bending the monopole degrades performance, whereas introducing a straight section and carefully optimizing the
curvature enables a 18.5% gain increase and a 400 kHz bandwidth expansion. The single-element design is further extended to a 12-element linear array with 0.45{\lambda} spacing (where {\lambda} is the wavelength), demonstrating stable embedded-element behavior and improved low-to- moderate elevation gain for skywave over-the-horizon radar operation. At {\theta} = 30{\deg}, the proposed array achieves 14.04 dBi compared to 13.11 dBi for the reference array, corresponding to 24% gain enhancement, which is significant in high-power HF radar systems. These results confirm that the proposed curved monopole
antenna provides a compact, broadband, and scalable solution for next-generation HF radar arrays.
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Systems and Control
Temperature-Aware Scheduling of LLM Inference in Large-Scale Geo-Distributed Edge Data Centers with Distributed Optimization
Arash Khalatbarisoltani, Amin Mahmoudi, Jie Han et al. (+6 more)
The environmental impact of Large
Language Models (LLMs) on data centers hosting these models is becoming a significant concern. While many efforts have focused on reducing the substantial training overhead of LLMs, carbon and water consumption during the inference phase can often surpass the costs associated with their training. The cooling systems of data centers are crucial in this context, but they are frequently modeled with a location-independent efficiency term. However, their energy efficiency is highly influenced by ambient temperature, which can vary significantly across different geographical locations. Leveraging this temperature diversity can help reduce total cooling energy costs and improve the performance of edge data centers. To address these critical sustainability issues related to LLMs, this study proposes a temperature-aware approach that co-optimizes LLM energy costs, carbon emissions, time-to-first
token, and water consumption. The approach employs a distributed optimization
algorithm based on an alternating direction method of multipliers, aimed at enhancing the sustainability of LLM hosting across geo-distributed edge data centers in Australia. Our method demonstrates reductions in cooling energy consumption and improves overall cost efficiency for geo-distributed cloud environments.
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All authors Arash Khalatbarisoltani, Amin Mahmoudi, Jie Han, Muhammad Saeed, Wenxue Liu, Jinwen Li, Solmaz Kahourzade, Amirmehdi Yazdani, Xiaosong Hu
Systems and Control
Robust Cooperative Output Regulation of Discrete-Time Heterogeneous Multi-Agent Systems
Kursad Metehan Gul and Selahattin Burak Sarsilmaz
This article considers robust cooperative output regulation of discrete-time uncertain heterogeneous (in dimension) multi-
agent systems (MASs). We show that the solvability of this problem with an internal model-based distributed control law reduces to the existence of a structured control gain that makes the nominal closed-loop system
matrix of the MAS Schur. Accordingly, this article focuses on global and
agent-wise local sufficient conditions for the existence and design of such a structured control gain. Based on a structured Lyapunov inequality, we present a convexification that yields a linear
matrix inequality (LMI), whose feasibility is a global sufficient condition for the existence and design. Considering the individual nominal dynamics of each
agent, the existence is also ensured if each
agent solves a structure-free control problem. Its convexification yields LMIs that allow each
agent to separately design its structure-free control gain. Lastly, we study the relationships between the sets of control gains emerging from both global and local perspectives.
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Systems and Control
Tunable Input-to-State Safety with Input Constraints
Ming Li, Jin Chen and Dimos V. Dimarogonas
Tunable input-to-state safety (TISSf) generalizes the input-to-state safety (ISSf) framework by incorporating a tuning function that regulates safety conservatism while preserving robustness against perturbations. Despite its flexibility, the TISSf tuning function is often designed without explicitly incorporating actuator limits, which can lead to incompatibility with input constraints. To address this gap, this paper proposes a framework that integrates general compact input constraints into tuning function synthesis. Leveraging a
geometric perspective, we characterize the TISSf condition as a state-dependent half-space constraint and derive a verifiable certificate for input compatibility using support functions. This characterization transforms the compatibility requirement into a design constraint on the tuning function, yielding a prescriptive lower bound that defines an admissible family of tunings under input constraints. These results are specialized to norm-bounded, polyhedral, and box constraints, yielding tractable control design conditions. We show that these conditions, combined with tuning function monotonicity, guarantee input compatibility and recursive feasibility of the resulting quadratic program (QP)-based safety filter. Furthermore, an offline parameter selection procedure using a covering-based sampling strategy ensures compatibility across the entire safe set via a linear program (LP). A connected cruise control (CCC) application demonstrates robust safety under TISSf while enforcing input constraints by design.
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Systems and Control · Cross-listed from cs.GT
A Lightweight MPC Bidding Framework for Brand Auction Ads
Yuanlong Chen, Bowen Zhu, Bing Xia et al. (+1 more)
Brand advertising plays a critical role in building long-term consumer awareness and loyalty, making it a key objective for advertisers across digital platforms. Although real-time bidding has been extensively studied, there is limited literature on
algorithms specifically tailored for brand auction ads that fully leverage their unique characteristics. In this paper, we propose a lightweight Model Predictive Control (MPC) framework designed for brand advertising campaigns, exploiting the inherent attributes of brand ads – such as stable user engagement patterns and fast feedback loops – to simplify modeling and improve efficiency. Our approach utilizes online isotonic regression to construct monotonic bid-to-spend and bid-to-conversion models directly from streaming data, eliminating the need for complex machine learning models. The
algorithm operates fully online with low computational overhead, making it highly practical for real-world deployment. Simulation results demonstrate that our approach significantly improves spend efficiency and cost control compared to baseline strategies, providing a scalable and easily implementable solution for modern brand advertising platforms.
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All authors Yuanlong Chen, Bowen Zhu, Bing Xia, Yichuan Wang
Signal Processing
Secure and Robust Beamforming Design for STAR-RIS-aided MU-MIMO ISAC Systems
Rakesh Ranjan, Anshu Mukherjee, Manjesh K. Hanawal et al. (+2 more)
Simultaneous transmitting and reflecting reconfigurable intelligent surfaces (
STAR-RIS) offer a transformative approach for integrated sensing and communication (
ISAC) systems, particularly for enhancing physical layer security (PLS). This paper investigates a robust, secure downlink transmission framework for a
STAR-RIS empowered multi-user (MU) multiple-input multiple-output (MU-
MIMO) system, where a multi-
antenna dual-function radar and communication base station (DFRC-BS) that simultaneously transmits confidential messages to multiple intended users (IUs) and performs target sensing in the presence of malicious eavesdroppers. To optimize system security, we formulate a worst-case robust beamforming problem to maximize the secrecy rate. This formulation jointly designs the active transmit beamforming at the BS and the passive reflection, transmission coefficients at the
STAR-RIS, adheres to transmit power budgets, user quality-of-service (QoS) thresholds, sensing signal-to-interference-plus-noise ratio (SINR) requirements, maximum tolerable eavesdropping leakage, and practical phase shifts constraints. To efficiently tackle the formulated problem, we develop an alternating optimization (AO)
algorithm. Specifically, the S-procedure is employed to solve semi-infinite channel uncertainty constraints, while semidefinite relaxation (SDR) and penalty convex-concave programming (CCP) are applied to obtain tractable suboptimal solutions. Extensive simulation results validate the efficacy of the proposed framework and demonstrate significant improvement in spectral efficiency compared to conventional reflecting-only RIS (R-RIS) systems under stringent sensing conditions.
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All authors Rakesh Ranjan, Anshu Mukherjee, Manjesh K. Hanawal, Keshav Singh, Ioannis Krikidis
Audio and Speech Processing
Multi-View Based Audio Visual Target Speaker Extraction
Peijun Yang, Zhan Jin, Juan Liu et al. (+1 more)
Audio-Visual Target Speaker Extraction (AVTSE) aims to separate a target speaker's voice from a mixed audio signal using the corresponding visual cues. While most existing AVTSE methods rely exclusively on frontal-view
videos, this limitation restricts their robustness in real-world scenarios where non-frontal views are prevalent. Such visual perspectives often contain complementary articulatory information that could enhance
speech extraction. In this work, we propose Multi-View Tensor Fusion (MVTF), a novel framework that transforms multi-view learning into single-view performance gains. During the training stage, we leverage synchronized multi-perspective lip
videos to learn cross-view correlations through MVTF, where pairwise outer products explicitly model multiplicative interactions between different views of input lip
embeddings. At the inference stage, the system supports both single-view and multi-view inputs. Experimental results show that in the single-view inputs, our framework leverages multi-view knowledge to achieve significant performance gains, while in the multi-view mode, it further improves overall performance and enhances the robustness. Our demo, code and data are available at https://anonymous.4open.science/w/MVTF-Gridnet-209C/
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All authors Peijun Yang, Zhan Jin, Juan Liu, Ming Li
Signal Processing · Cross-listed from cs.NE
A Primer on Evolutionary Optimization Frameworks for Near-Field Multi-Source Localization
Seyed Jalaleddin Mousavirad, Parisa Ramezani, Mattias O'Nils et al. (+1 more)
This paper introduces evolutionary optimization as a grid-free training-free continuous-domain search mechanism for near-field multi-source localization, addressing the major limitations of grid-based subspace methods such as MUSIC and data-driven deep learning approaches. To this end, we develop two complementary evolutionary localization frameworks that operate directly on the continuous spherical-wave signal model and support arbitrary array geometries without requiring labeled data, discretized angle-range grids, or architectural constraints. The first framework, termed NEar-field
MultimOdal DE (NEMO-DE) associates each individual in the evolutionary population to a single source and optimizes a residual least-squares objective in a sequential manner, updating the data residual and enforcing spatial separation to estimate multiple source locations. To overcome the limitation of NEMO-DE under large power imbalances among the sources, we propose the second framework, named NEar-field Eigen-subspace Fitting DE (NEEF-DE), which jointly encodes all source locations and minimizes a subspace-fitting criterion that aligns a model-based array response subspace with the received signal subspace. The proposed formulations are not intrinsically tied to a specific optimizer; however, this work adopts differential
evolution (DE) as a representative evolutionary search strategy because of its simple implementation, small number of control parameters, and strong empirical performance in continuous nonconvex optimization problems. Numerical results show that the proposed frameworks provide competitive accuracy compared with MUSIC-type baselines while avoiding pre-defined grid construction and labeled training data. This work establishes evolutionary computation as a powerful and flexible paradigm for model-based near-field localization, paving the way for future innovations in this domain.
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All authors Seyed Jalaleddin Mousavirad, Parisa Ramezani, Mattias O'Nils, Emil Björnson
Signal Processing
Cooperative Multi-Satellite ISAC Networks: Centralized vs. Distributed Sensing
Jeongbin Kim, Jaehong Jo, Seunghyeon Jeon et al. (+3 more)
This paper investigates a downlink multi-satellite integrated sensing and communication (
ISAC) network, in which multiple satellites simultaneously transmit
ISAC signals to provide communication services to ground user equipments and enable cooperative sensing of airborne targets through multiple gateways. To support this dual functionality, we introduce communication and sensing beamforming designs based on uniform planar arrays with optimized power allocation. Building on these designs, we propose two cooperative sensing frameworks, namely centralized and distributed. In the centralized framework, each gateway forwards its sensing observations to a central unit (CU), where the positions of multiple targets are jointly estimated from the aggregated data. To mitigate the signaling overhead inherent in centralized processing, a distributed framework is further proposed, in which each gateway independently estimates target positions and transmits only the local estimates to the CU. To associate estimates from different gateways, a data association problem based on the squared Euclidean distance is formulated and efficiently solved using the Hungarian
algorithm. The final target positions are then obtained by minimizing the distance error. Simulation results demonstrate that the proposed centralized and distributed frameworks significantly outperform existing sensing schemes while satisfying communication performance requirements. Finally, we evaluate the sensing-communication trade-off from the viewpoints of sensing accuracy and communication power consumption under the proposed frameworks.
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All authors Jeongbin Kim, Jaehong Jo, Seunghyeon Jeon, Yo-Seb Jeon, Wonjae Shin, H. Vincent Poor
Signal Processing
MetaSort: An Accelerated Approach for Non-uniform Compression and Few-shot Classification of Neural Spike Waveforms
Luca M. Meyer and Majid Zamani
Many previous works in spike sorting study spike classification and compression independently. In this paper, a novel
algorithm is proposed called MetaSort to address these two problems. To deal with compression, a novel adaptive level crossing
algorithm is proposed to approximate spike shapes with high fidelity. Meanwhile, the latent feature representation is used to handle the classification problem. Besides, to guarantee MetaSort is robust and discriminative, the
geometric information of data is exploited simultaneously in the proposed framework by meta-transfer learning. Empirical experiments with in-vivo spike data demonstrate that MetaSort delivers promising performance, highlighting its potential and motivating continued development toward an ultra-low-power, on-chip implementation.
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Systems and Control
VB-NET: A physics-constrained gray-box deep learning framework for modeling air conditioning systems as virtual batteries
Yuchen Qi, Ye Guo and Yinliang Xu
The increasing penetration of renewable energy necessitates unlocking demand-side flexibility. While air conditioning (AC) systems offer significant thermal inertia, existing physical and data-driven models struggle with parameter acquisition, interpretability, and data scarcity. This paper proposes VB-NET, a physics-constrained gray-box deep learning framework that transforms complex AC thermodynamics into a standardized Virtual Battery (VB) model. We first mathematically prove the isomorphic equivalence between the AC and VB models. Subsequently, VB-NET is designed to strictly enforces physical laws by decoupling shared meteorological drivers from private building thermal fingerprints and
embedding a differentiable physics layer. Experimental results demonstrate that VB-NET significantly outperforms conventional black-box models in state of charge tracking while successfully recovering underlying thermodynamic laws to yield physically consistent parameters. Furthermore, utilizing multi-task learning and terminal sensitivity modulation, VB-NET overcomes the cold-start dilemma, achieving high-precision modeling for new AC units using only 2% to 6% of historical data. Ultimately, this study provides an interpretable and data-efficient pathway for aggregating decentralized AC resources for grid regulation.
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Audio and Speech Processing · Cross-listed from cs.SD
Analysis-Driven Procedural Generation of an Engine Sound Dataset with Embedded Control Annotations
Robin Doerfler and Lonce Wyse
Computational engine sound modeling is central to the automotive audio industry, particularly for active sound design applications and virtual prototyping. Emerging data-driven engine sound synthesis methods require large volumes of standardized, clean audio recordings with precisely time-aligned operating-state annotations: data that is difficult to obtain due to high costs, specialized measurement equipment requirements, and inevitable noise contamination. We present an analysis-driven framework for generating engine audio with sample-accurate control annotations. The method extracts harmonic structures from real recordings through pitch-adaptive spectral analysis, which then drive an extended parametric harmonic-plus-noise synthesizer. With this framework, we augment 5-10 min of source audio per engine 15-30x via diverse control trajectories and parametric variation, producing the Procedural Engine Sounds
Dataset (19.0 h, 5,935 files): a set of engine audio signals with sample-accurate RPM and torque annotations spanning a wide range of operating conditions, signal complexities, and harmonic profiles. Comparison against real recordings validates that the synthesized data preserves characteristic harmonic structures, and a baseline differentiable synthesis network trained on the
dataset confirms its suitability for data-driven engine sound modeling. The
dataset is released publicly to support research on engine timbre analysis, control parameter estimation, and neural generative synthesis.
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