Alessio Lukaj;Keigo Masuoka;Takumi Takahashi;Giuseppe Thadeu Freitas de Abreu;Hideki Ochiai
{"title":"Quaternion-Domain Super MDS for Robust 3D Localization","authors":"Alessio Lukaj;Keigo Masuoka;Takumi Takahashi;Giuseppe Thadeu Freitas de Abreu;Hideki Ochiai","doi":"10.1109/OJSP.2026.3693590","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3693590","url":null,"abstract":"This paper proposes a novel low-complexity three-dimensional (3D) localization algorithm for wireless sensor networks, termed quaternion-domain super multi-dimensional scaling (QD-SMDS). The algorithm is based on a reformulation of the SMDS, originally developed in the real domain and for two-dimensional (2D) problems, using quaternion algebra. By representing 3D coordinates as quaternions, the method constructs a rank-1 Gram edge kernel (GEK) matrix that integrates both relative distance and angular information between nodes, which enhances the noise reduction effect achieved through low-rank truncation employing singular value decomposition (SVD), thereby improving robustness against information loss. To further reduce computational complexity, we also propose a variant of QD-SMDS that eliminates the need for the computationally expensive SVD by leveraging the inherent structure of the quaternion-domain GEK matrix. This alternative directly estimates node coordinates using only matrix multiplications within the quaternion domain. Simulation results demonstrate that the proposed method significantly improves localization accuracy compared to the original SMDS algorithm, especially in scenarios with substantial measurement errors. The proposed method also achieves comparable localization accuracy without requiring SVD.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"621-642"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11520270","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148236198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Real-Time Non-Uniform Fast Fourier Transform for Multibeam Digital Beamforming","authors":"Piero Angeletti;Adem Coskun;Izzet Kale","doi":"10.1109/OJSP.2026.3719966","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3719966","url":null,"abstract":"This paper describes the structure of a reconfigurable digital beamforming network, which offers significant improvements in implementation complexity and cost, while maintaining a high degree of flexibility. This architecture supports a multi-beam array antenna and allows complete flexibility in steering each individual beam produced by this antenna, achieving computational complexity comparable to that of the Fast Fourier Transform as the number of beams and antenna elements change. The proposed architecture is built upon the theory behind the Non-Uniform Fast Fourier Transform and is demonstrated for linear array geometries with regular or non-regular element positions. Fixed-point simulations, with a view to real-time hardware implementation, demonstrate effective reduction in the computational complexity of the reconfigurable digital beamforming network and its full flexibility.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"1030-1042"},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11641003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149188481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mingzhuo Li;Guang Li;Linfeng Ye;Jiafeng Mao;Takahiro Ogawa;Konstantinos N. Plataniotis;Miki Haseyama
{"title":"SAS: Semantic-Aware Sampling for Generative Dataset Distillation","authors":"Mingzhuo Li;Guang Li;Linfeng Ye;Jiafeng Mao;Takahiro Ogawa;Konstantinos N. Plataniotis;Miki Haseyama","doi":"10.1109/OJSP.2026.3703204","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3703204","url":null,"abstract":"Deep neural networks have achieved impressive performance across a wide range of tasks, but this success often comes with substantial computational and storage costs due to large-scale training data. Dataset distillation addresses this challenge by constructing compact yet informative datasets that enable efficient model training while maintaining downstream performance. However, most existing approaches primarily emphasize matching data distributions or downstream training statistics, with limited attention to preserving high-level semantic information in the distilled data. In this work, we introduce a semantic-aware perspective for dataset distillation by leveraging Contrastive Language–Image Pretraining (CLIP) as a semantic prior for post-sampling. Our goal is to obtain distilled datasets that are not only compact but also semantically class-discriminative and diverse. To this end, we design three semantic scoring functions that quantify class relevance, inter-class separability, and intra-set diversity in a pretrained semantic space. Based on image pools generated by existing distillation methods, we further develop a two-stage strategy for effective sampling: the first stage filters semantically discriminative samples to form a reliable candidate set, and the second stage performs a dynamic diversity-aware selection to reduce redundancy while preserving semantic coverage. Extensive experiments across multiple datasets, image pools, and downstream models demonstrate consistent performance gains, highlighting the effectiveness of incorporating semantic information into dataset distillation.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"668-677"},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11561066","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148442449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pietro Bongini;Meiling Li;Andrea Costanzo;Benedetta Tondi;Mauro Barni
{"title":"Source Attribution of AI-Generated Images in Data Scarcity Conditions via Training-Free Resynthesis","authors":"Pietro Bongini;Meiling Li;Andrea Costanzo;Benedetta Tondi;Mauro Barni","doi":"10.1109/OJSP.2026.3710125","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3710125","url":null,"abstract":"Attributing synthetic images to the source that generated them is a difficult problem, particularly in data-scarcity conditions requiring the adoption of few-shot or zero-shot learning strategies. In this paper, we tackle this problem by introducing a training-free attribution method based on image resynthesis. Our method works by first automatically generating a textual prompt which describes the target image, and then using it to resynthesize the image with each candidate generator. Attribution is obtained by matching the image to the model whose resynthesis is most similar to the original one within an appropriate feature space - chosen based on a preliminary experimental analysis - among several possibilities offered by modern deep learning image analysis tools. Experiments using state-of-the-art few-shot models and other baselines show that our resynthesis-based method outperforms existing techniques when only a limited number of images are available for training or fine-tuning. Particular attention is given to assessing the robustness of the proposed method against common image processing operators and its adversarial robustness. In particular, the experimental results show that our method is robust to post-processing and that its adversarial robustness is significantly higher than that of baselines.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"730-745"},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11594904","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148479043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Asutosh Kar;Pradeep K. Shill;Abhishek S. Shamkuwar;Samridhi Saini;Vasundhara;S. Shoba;Mads Græsbøll Christensen
{"title":"Adaptive Improved Primal-Dual Distributed Stochastic Gradient Driven Distributed Active Noise Control System","authors":"Asutosh Kar;Pradeep K. Shill;Abhishek S. Shamkuwar;Samridhi Saini;Vasundhara;S. Shoba;Mads Græsbøll Christensen","doi":"10.1109/OJSP.2026.3701314","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3701314","url":null,"abstract":"Distributed active noise control (DANC) systems, typically employing the filtered-x least mean squares algorithm, are widely used for spatial noise reduction in acoustic networks. However, due to acoustic coupling among the nodes, vulnerability to impulsive interference, and degradation in non-Gaussian noise environments, the performance of these systems degrades. Additionally, most of the existing DANC frameworks neglect practical limitations in communication, such as transmission delays and interruptions, which limits their scalability in real-world deployments. To address these challenges, an adaptive improved distributed stochastic gradient (AIDSG) algorithm grounded within the primal-dual optimization framework is introduced in this paper. The proposed approach initiates an informed primal-dual update across nodes with instantaneous dual feedback, which results in resilience against colored and impulsive noise, accelerates convergence, and increases adaptability to dynamically changing acoustic environments. Four types of algorithm variants are presented, which address the trade-off between convergence speed and steady-state error. Simulation results on a five-node network validate the superiority of the AIDSG algorithm over conventional DANC and diffusion-based schemes while demonstrating better residual reduction performance, faster mean square convergence, and a better mean noise ratio under additive white Gaussian noise, colored noise, and impulsive noise conditions.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"643-658"},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11553366","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148433134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Speaker-Disentangled Chunk-Wise Regression for Syllabic Tokenization","authors":"Ryota Komatsu;Kota Kawakita;Takuma Okamoto;Takahiro Shinozaki","doi":"10.1109/OJSP.2026.3711530","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3711530","url":null,"abstract":"Unsupervised syllabic tokenization aims to learn discrete syllabic tokens that capture latent linguistic content-related structure from raw speech. Recent syllabic tokenization methods employ teacher-student distillation of the pretrained HuBERT to organize latent speech frame representations into syllabic segments. However, when trained with an utterance-level cross-entropy objective, the model predicts speaker identity rather than linguistic content, thereby compromising the purity of syllabic tokens. To address this problem, we propose a speaker-disentangled syllabic tokenizer that regresses speaker-perturbed student representations toward clean teacher targets within fixed-length chunks. Experimental results demonstrate that our proposed method achieves state-of-the-art performance in syllable boundary detection and syllabic segment clustering. Moreover, a speech language model trained on our syllabic tokens achieves a 7% relative improvement in syntactic and semantic understanding over the phone-level SpiRit-LM.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"800-808"},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11599637","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148626177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giovanna Sannino;Ivanoe De Falco;Nadia Brancati;Laura Verde;Maria Frucci;Daniel Riccio;Vincenzo Bevilacqua;Antonio Di Marino;Lucia Aruta;Valentina Virginia Iuzzolino;Gianmaria Senerchia;Myriam Spisto;Raffaele Dubbioso
{"title":"SAND: The Challenge on Speech Analysis for Neurodegenerative Disease Assessment","authors":"Giovanna Sannino;Ivanoe De Falco;Nadia Brancati;Laura Verde;Maria Frucci;Daniel Riccio;Vincenzo Bevilacqua;Antonio Di Marino;Lucia Aruta;Valentina Virginia Iuzzolino;Gianmaria Senerchia;Myriam Spisto;Raffaele Dubbioso","doi":"10.1109/OJSP.2026.3713044","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3713044","url":null,"abstract":"Recent advances in Artificial Intelligence (AI) and the exploration of noninvasive, objective biomarkers, such as speech signals, have encouraged the development of algorithms to support the early diagnosis of neurodegenerative diseases, including Amyotrophic Lateral Sclerosis (ALS). Voice changes in subjects suffering from ALS typically manifest as progressive dysarthria, which is a prominent neurodegenerative symptom because it affects patients as the disease progresses. Since voice signals are complex data, the development and use of advanced AI techniques are fundamental to extracting distinctive patterns from them. Validating AI algorithms for ALS diagnosis and monitoring using voice signals is challenging, particularly due to the lack of annotated datasets. In this work, we present the outcome of a collaboration between a multidisciplinary team of clinicians and computer science experts to create both a clinically annotated dataset and the “Speech Analysis for Neurodegenerative Diseases” (SAND) challenge based on it. By analyzing voice disorders, the SAND challenge provides an opportunity to develop, test, and evaluate AI models for the automatic early identification and prediction of ALS disease progression.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"766-775"},"PeriodicalIF":2.6,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11606418","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148626181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pradeep K. Shill;Asutosh Kar;Mads Græsbøll Christensen
{"title":"Temporal Dynamics Based Adaptive Control Mechanism for Improved Narrowband Noise Cancellation","authors":"Pradeep K. Shill;Asutosh Kar;Mads Græsbøll Christensen","doi":"10.1109/OJSP.2026.3692409","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3692409","url":null,"abstract":"Traditional hybrid narrowband active noise control (HNANC) systems typically rely on fixed or energy-based variable step-size adaptation. These adaptation methods sometimes result in suboptimal convergence and poor trade-offs between convergence speed and steady-state performance in the presence of nonstationary tonal disturbances and secondary-path modelling errors. These methods often necessitate persistent external references and face challenges in managing feedforward-feedback loop interactions, which impairs robustness in practical narrowband noise environments. This paper proposes a temporal coherence–driven adaptive control mechanism for HNANC systems, in which the instantaneous coherence between a predefined reference signal and the residual error is used as a tracking-confidence metric to regulate adaptive step-sizes. The temporal coherence emphasizes structured narrowband components while suppressing updates driven by incoherent residuals, thereby improving adaptation behavior under nonstationary conditions. The proposed approach integrates a supporting control filter with coherence-based step-size scheduling to coordinate feedforward and feedback adaptation using normalized least mean square algorithms. Simulation and experimental results under multiple narrowband noise scenarios demonstrate faster retracking and improved stability compared to state-of-the-art HNANC methods, with a modest increase in computational load.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"551-568"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11515074","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148171726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep Spatio-Temporal and Frequency Guided Fusion Network for Event-to-Video Reconstruction","authors":"Ramna Maqsood;Paulo Nunes;Caroline Conti;Luís Ducla Soares","doi":"10.1109/OJSP.2026.3693230","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3693230","url":null,"abstract":"Event-to-video (E2V) reconstruction has gained significant attention recently for its advantages in enabling high dynamic range and fast motion capture capabilities. However, event data encodes only relative brightness changes, lacking the absolute intensity information necessary for accurate reconstruction. Recent methods incorporate previously reconstructed images to provide intensity references but process them in the spatial domain where low- and high-frequency components are highly coupled. This spatial processing typically leads to the degradation of fine details and introduces artifacts such as over-smoothing, blurring and low contrast reconstruction. To address this, we propose a deep spatio-temporal and frequency guided fusion network for E2V reconstruction (DSTFN-E2V), featuring a dual-path architecture with two key components: i) a prior frequency decomposition module (PFDM), and ii) a spatio-temporal event-driven feature extraction module (STEM). The PFDM decouples low- and high-frequency information from previously reconstructed images and current event voxel grid via a 2D discrete wavelet transform, processing the low-frequency subband through residual blocks to preserve structural coherence and intensity references, while an edge-detail refinement module (ERM) enhances edge and texture details from high-frequency subbands. The frequency-specific features from PFDM and the spatio-temporal features from STEM are then integrated through the proposed event-image fusion blocks (EIFBs) that apply cross-attention across three encoder stages, enabling simultaneous structural preservation and detail recovery. Experiments on four real-world datasets demonstrate that DSTFN-E2V achieves state-of-the-art results with 12% SSIM improvements while being 50% faster than recent attention-based methods, with superior edge fidelity and reduced artifacts.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"541-550"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11520274","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148171749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eva Dubar;Sarah Dury;Gauthier Lafruit;Daniele Bonatto
{"title":"Failing to Reflect Reality: Gaussian Splatting’s Collapse on Non-Lambertian Surfaces","authors":"Eva Dubar;Sarah Dury;Gauthier Lafruit;Daniele Bonatto","doi":"10.1109/OJSP.2026.3685574","DOIUrl":"https://doi.org/10.1109/OJSP.2026.3685574","url":null,"abstract":"We explore the applicability of Gaussian Splatting (GS) to the view synthesis (VS) of non-Lambertian objects. Materials with anisotropic appearance have always been a failure case for VS, until the recent introduction of spherical harmonics promising satisfying results to handle view-directional aspects. Nevertheless, we demonstrate that highly non-Lambertian objects, such as glass or mirrors, remain impossible to correctly reconstruct and render with Gaussian primitives and spherical harmonics. This paper clarifies the reasons: (1) Gaussian Splatting optimization converges to incorrect geometry, and (2) spherical harmonics fail to represent consistent view dependencies. Benchmarking experiments confirm that gs produces false geometry even with ground truth data. Our findings call into question current material representations in view synthesis and motivate the use of more realistic primitives.","PeriodicalId":73300,"journal":{"name":"IEEE open journal of signal processing","volume":"7 ","pages":"447-455"},"PeriodicalIF":2.7,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11489163","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147828893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}