Signal Processing
A Multiscale Approach for Enhancing Weak Signal Detection
Dixon Vimalajeewa, Ursula U. Muller and Brani Vidakovic
Stochastic resonance (SR), a phenomenon originally introduced in
climate modeling, enhances signal detection by leveraging optimal noise levels within non-linear systems. Traditional SR techniques, mainly based on single-threshold detectors, are limited to signals whose behavior does not depend on time. Often large amounts of noise are needed to detect weak signals, which can distort complex signal characteristics. To address these limitations, this study explores multi-threshold systems and the application of SR in multiscale applications using wavelet transforms. In the multiscale domain signals can be analyzed at different levels of resolution to better understand the underlying dynamics. We propose a double-threshold detection system that integrates two single-threshold detectors to enhance weak signal detection. We evaluate it both in the original data domain and in the multiscale domain using simulated and real-world signals and compare its performance with existing methods. Experimental results demonstrate that, in the original data domain, the proposed double-threshold detector significantly improves weak signal detection compared to conventional single-threshold approaches. Its performance is further improved in the frequency domain, requiring lower noise levels while outperforming existing detection systems. This study advances SR-based detection methodologies by introducing a robust approach to weak signal identification, with potential applications in various disciplines.
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Audio and Speech Processing · Cross-listed from cs.SD
Beyond Discrete Categories: Multi-Task Valence-Arousal Modeling for Pet Vocalization Analysis
Junyao Huang and Rumin Situ
Traditional pet
emotion recognition from vocalizations, based on discrete classification, struggles with ambiguity and capturing intensity variations. We propose a continuous Valence-Arousal (VA) model that represents
emotions in a two-dimensional space. Our method uses an automatic VA label generation
algorithm, enabling large-scale annotation of 42,553 pet vocalization samples. A multi-task learning framework jointly trains VA regression with auxiliary tasks (
emotion, body size, gender) to enhance prediction by improving feature learning. Our Audio
Transformer model achieves a validation Valence Pearson correlation of r = 0.9024 and an Arousal r = 0.7155, effectively resolving confusion between discrete categories like "territorial" and "happy." This work introduces the first continuous VA framework for pet vocalization analysis, offering a more expressive representation for human-pet interaction, veterinary diagnostics, and behavioral training. The approach shows strong potential for deployment in consumer products like AI pet
emotion translators.
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Systems and Control · Cross-listed from math.OC
Optimal Control with Lyapunov Stability Guarantees for Space Applications
Abhijeet, Mohamed Naveed Gul Mohamed, Aayushman Sharma et al. (+1 more)
This paper investigates the infinite horizon optimal control problem (OCP) for space applications characterized by nonlinear dynamics. The proposed approach divides the problem into a finite horizon OCP with a regularized terminal cost, guiding the system towards a terminal set, and an infinite horizon linear regulation phase within this set. This strategy guarantees global asymptotic stability under specific assumptions. Our method maintains the system's fully nonlinear dynamics until it reaches the terminal set, where the system dynamics is linearized. As the terminal set converges to the origin, the difference in optimal cost incurred reduces to zero, guaranteeing an efficient and stable solution. The approach is tested through simulations on three problems: spacecraft attitude control, rendezvous maneuver, and soft landing. In spacecraft attitude control, we focus on achieving precise orientation and stabilization. For rendezvous maneuvers, we address the
navigation of a chaser to meet a target spacecraft. For the soft landing problem, we ensure a controlled descent and touchdown on a planetary surface. We provide numerical results confirming the effectiveness of the proposed method in managing these nonlinear dynamics problems, offering robust solutions essential for successful space missions.
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All authors Abhijeet, Mohamed Naveed Gul Mohamed, Aayushman Sharma, Suman Chakravorty
Systems and Control
Joint Detection, Channel Estimation and Interference Nulling for Terrestrial-Satellite Downlink Co-Existence in the Upper Mid-Band
Shizhen Jia, Mingjun Ying, Marco Mezzavilla et al. (+3 more)
The upper mid-band FR3 spectrum (7-24 GHz) has garnered significant interest for future cellular services. However, utilizing a large portion of this band requires careful interference coordination with incumbent satellite systems. This paper investigates interference from high-power terrestrial base stations (TN-BSs) to satellite downlink receivers. A central challenge is that the victim receivers, i.e., ground-based non-terrestrial user equipment (NTN-UEs) such as satellite customer premises equipment, must first be detected and their channels estimated before the TN-BS can effectively place nulls in their directions. We explore a potential solution where NTN-UEs periodically transmit preambles or beacon signals that TN-BSs can use for detection and channel estimation. The performance of this nulling approach is analyzed in a simplified scenario with a single victim, revealing the interplay between path loss and estimation quality in determining nulling performance. To further validate the method, we conduct a detailed multi-user site-specific ray-tracing (RT) simulation in a rural environment. The results show that the proposed nulling approach is effective under realistic parameters, even with high densities of victim units, although TN-BS may require a substantial number of
antennas.
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All authors Shizhen Jia, Mingjun Ying, Marco Mezzavilla, Doru Calin, Theodore S. Rappaport, Sundeep Rangan
Audio and Speech Processing · Cross-listed from cs.SD
Audible Networks: Deconstructing and Manipulating Sounds with Deep Non-Negative Autoencoders
Juan José Burred and Carmine-Emanuele Cella
We propose the use of Non-Negative Autoencoders (NAEs) for sound deconstruction and user-guided manipulation of sounds for creative purposes. NAEs offer a versatile and scalable extension of traditional Non-Negative
Matrix Factorization (NMF)-based approaches for interpretable audio decomposition. By enforcing non-negativity constraints through projected gradient descent, we obtain decompositions where internal weights and activations can be directly interpreted as spectral shapes and temporal envelopes, and where components can themselves be listened to as individual sound events. In particular, multi-layer Deep NAE architectures enable hierarchical representations with an adjustable level of granularity, allowing sounds to be deconstructed at multiple levels of abstraction: from high-level note envelopes down to fine-grained spectral details. This framework enables a wide new range of expressive, controllable, and randomized sound transformations. We introduce novel manipulation operations including cross-component and cross-layer synthesis, hierarchical deconstructions, and several randomization strategies that control timbre and event density. Through visualizations and resynthesis of practical examples, we demonstrate how NAEs can serve as flexible and interpretable tools for object-based sound editing.
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Signal Processing · Cross-listed from cs.IT
On Estimation of Angles of Arrival in Monostatic ISAC Without Instantaneous Transmit CSI
Ataher Sams, Simone Di Bari, Besma Smida et al. (+3 more)
This paper explores the fundamental limits of Integrated Sensing and Communication (
ISAC) in a more realistic setting compared to previous literature when the Base Staion (BS) has only statistical CSI of the communication user rather than full CSI. We analyze a monostatic setting where the BS performs multi-target Angle of Arrival (AoA) estimation while simultaneously communicating with one of the targets. We assume that the BS has statistical CSI about all AoAs, with less uncertainty in the AoA of the communication receiver. The communication receiver is assumed to have perfect CSI. Utilizing a
Bayesian Cramér-Rao Bound (BCRB) framework to characterize the fundamental limits of sensing under minimum mean square error (MMSE) criteria, we derive achievable BCRB-rate trade-off regions. Our approach introduces a number of transmission strategies that share power across sensing and communication beams over a coherence time. Our analysis reveals that beam allocation strategies leveraging the principal eigenvectors of the target-specific sensing
matrices minimize individual AoA estimation errors, while strategies balancing sensing and communication directions optimize joint estimation performance at the cost of individual accuracy. We demonstrate that leveraging updated BCRB-based sensing information for the communication receiver, due to its lower channel uncertainty, enables significantly improved communication rates.
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All authors Ataher Sams, Simone Di Bari, Besma Smida, Natasha Devroye, Daniela Tuninetti, Giorgio Taricco
Signal Processing
UAV-Assisted 3-D Localization for IoT Networks Using a Simple and Efficient TDOA-AOA Estimator
Mojtaba Amiri and Rouhollah Amiri
This letter proposes an algebraic solution for the problem of 3-D source localization utilizing the minimum number of measurements, i.e., one Time Difference of Arrival (TDOA) and one Angle of Arrival (AOA) pair. The proposed method employs a closed-form weighted least squares
estimator and enables the positioning using a single ground station and a cooperative
UAV relaying the signal. Analytical derivations and simulation results demonstrate effectiveness of the proposed approach, achieving near-optimal performance aligned with the Cramér-Rao Lower Bound (CRLB) under moderate Gaussian noise conditions.
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Systems and Control · Cross-listed from cs.RO
Whole Body Model Predictive Control for Spin-Aware Quadrupedal Table Tennis
David Nguyen, Zulfiqar Zaidi, Kevin Karol et al. (+2 more)
Developing table tennis
robots that mirror human speed, accuracy, and ability to predict and respond to the full range of ball
spins remains a significant challenge for legged
robots. To demonstrate these capabilities we present a system to play dynamic table tennis for quadrupedal
robots that integrates high speed perception, trajectory prediction, and agile control. Our system uses external cameras for high-speed ball localization, physical models with learned residuals to infer
spin and predict trajectories, and a novel model predictive control (MPC) formulation for agile full-body control. Notably, a continuous set of stroke strategies emerge automatically from different ball return objectives using this control paradigm. We demonstrate our system in the real world on a Spot quadruped, evaluate accuracy of each system component, and exhibit coordination through the system's ability to aim and return balls with varying
spin types. As a further demonstration, the system is able to rally with human players.
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All authors David Nguyen, Zulfiqar Zaidi, Kevin Karol, Jessica Hodgins, Zhaoming Xie
Signal Processing · Cross-listed from cs.NI
Curated Wireless Datasets for Aerial Network Research
Amir Hossein Fahim Raouf, Donggu Lee, Mushfiqur Rahman et al. (+18 more)
This Review consolidates publicly available aerial wireless measurement
datasets collected using AERPAW. We organize signal-level, power-level, and KPI-level
datasets under a unified taxonomy, harmonize metadata, and provide verified access with reproducible post-processing scripts. The curated catalog supports propagation modeling, machine learning, localization, and system-level evaluation for 5G-Advanced and emerging 6G aerial networks.
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All authors Amir Hossein Fahim Raouf, Donggu Lee, Mushfiqur Rahman, Saad Masrur, Gautham Reddy, Cole Dickerson, Md Sharif Hossen, Sergio Vargas Villar, An{\i}l Gürses, Simran Singh, Sung Joon Maeng, Martins Ezuma, Christopher Roberts, Mohamed Rabeek Sarbudeen, Thomas J. Zajkowski, Magreth Mushi, Ozgur Ozdemir, Ram Asokan, Ismail Guvenc, Mihail L. Sichitiu, Rudra Dutta
Systems and Control · Cross-listed from cs.ET
When to Reason: Semantic Router for vLLM
Chen Wang, Xunzhuo Liu, Yuhan Liu et al. (+4 more)
Large
Language Models (LLMs) demonstrate substantial accuracy gains when augmented with
reasoning modes such as chain-of-thought and inference-time scaling. However,
reasoning also incurs significant costs in inference latency and
token usage, with environmental and financial impacts, which are unnecessary for many simple
prompts. We present a semantic router that classifies queries based on their
reasoning requirements and selectively applies
reasoning only when beneficial. Our approach achieves a 10.2 percentage point improvement in accuracy on the MMLU-Pro
benchmark while reducing response latency by 47.1% and
token consumption by 48.5% compared to direct inference with vLLM. These results demonstrate that semantic routing offers an effective mechanism for striking a balance between accuracy and efficiency in open-source LLM serving systems
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All authors Chen Wang, Xunzhuo Liu, Yuhan Liu, Yue Zhu, Xiangxi Mo, Junchen Jiang, Huamin Chen
Image and Video Processing
Interlaced dynamic XCT reconstruction with spatio-temporal implicit neural representations
Mathias Boulanger and Ericmoore Jossou
In this work, we investigate the use of spatio-temporalImplicit Neural Representations (INRs) for dynamic X-ray computed
tomography (XCT) reconstruction under interlaced acquisition schemes. The proposed approach combines ADMM-based optimization with INCODE, a conditioning framework incorporating prior knowledge, to enable efficient convergence. We evaluate our method under diverse acquisition scenarios, varying the severity of global undersampling, spatial complexity (quantified via spatial information), and noise levels. Across all settings, our model achieves strong performance and outperforms Time-Interlaced Model-Based Iterative Reconstruction (TIMBIR), a state-of-the-art model-based iterative method. In particular, we show that the inductive bias of the INR provides good robustness to moderate noise levels, and that introducing explicit noise modeling through a weighted least squares data fidelity term significantly improves performance in more challenging regimes. The final part of this work explores extensions toward a practical reconstruction framework. We demonstrate the modularity of our approach by explicitly modeling detector non-idealities, incorporating ring artifact correction directly within the reconstruction process. Additionally, we present a proof-of-concept 4D volumetric reconstruction by jointly optimizing over batched axial slices, an approach which opens up the possibilities for massive parallelization, a critical feature for processing large-scale
datasets.
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Image and Video Processing
AI-Driven Radiology Report Generation for Traumatic Brain Injuries
Riadh Bouslimi, Houda Trabelsi, Wahiba Ben Abdssalem Karaa et al. (+1 more)
Traumatic
brain injuries present significant diagnostic challenges in emergency medicine, where the timely interpretation of medical images is crucial for patient outcomes. In this paper, we propose a novel AI-based approach for automatic radiology report generation tailored to cranial trauma cases. Our model integrates an AC-BiFPN with a
Transformer architecture to capture and process complex medical imaging data such as CT and MRI scans. The AC-BiFPN extracts multi-scale features, enabling the detection of intricate anomalies like intracranial hemorrhages, while the
Transformer generates coherent, contextually relevant diagnostic reports by modeling long-range dependencies. We evaluate the performance of our model on the RSNA Intracranial Hemorrhage Detection
dataset, where it outperforms traditional CNN-based models in both diagnostic accuracy and report generation. This solution not only supports radiologists in high-pressure environments but also provides a powerful educational tool for trainee physicians, offering real-time feedback and enhancing their learning experience. Our findings demonstrate the potential of combining advanced feature extraction with
transformer-based text generation to improve clinical decision-making in the diagnosis of traumatic
brain injuries.
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All authors Riadh Bouslimi, Houda Trabelsi, Wahiba Ben Abdssalem Karaa, Hana Hedhli
Systems and Control · Cross-listed from cs.RO
Reliability of Single-Level Equality-Constrained Inverse Optimal Control
Filip Bečanović, Kosta Jovanović and Vincent Bonnet
Inverse optimal control (IOC) allows the
retrieval of optimal cost function weights, or behavioral parameters, from human motion. The literature on IOC uses methods that are either based on a slow bilevel process or a fast but noise-sensitive minimization of optimality condition violation. Assuming equality-constrained optimal control models of human motion, this article presents a faster but robust approach to solving IOC using a single-level reformulation of the bilevel method and yields equivalent results. Through numerical experiments in simulation, we analyze the robustness to noise of the proposed single-level reformulation to the bilevel IOC formulation with a human-like planar reaching task that is used across recent studies. The approach shows resilience to very large levels of noise and reduces the computation time of the IOC on this task by a factor of 15 when compared to a classical bilevel implementation.
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Audio and Speech Processing
MeanVC: Lightweight and Streaming Zero-Shot Voice Conversion via Mean Flows
Guobin Ma, Jixun Yao, Ziqian Ning et al. (+4 more)
Zero-shot voice conversion (VC) aims to transfer timbre from a source speaker to any unseen target speaker while preserving linguistic content. Growing application scenarios demand models with streaming inference capabilities. This has created a pressing need for models that are simultaneously fast, lightweight, and high-fidelity. However, existing streaming methods typically rely on either autoregressive (AR) or non-autoregressive (NAR) frameworks, which either require large parameter sizes to achieve strong performance or struggle to generalize to unseen speakers. In this study, we propose MeanVC, a lightweight and streaming zero-shot VC approach. MeanVC introduces a
diffusion transformer with a chunk-wise autoregressive denoising strategy, combining the strengths of both AR and NAR paradigms for efficient streaming processing. By introducing mean flows, MeanVC regresses the average velocity field during training, enabling zero-shot VC with superior
speech quality and speaker similarity in a single sampling step by directly mapping from the start to the endpoint of the flow trajectory. Additionally, we incorporate
diffusion adversarial post-training to mitigate over-smoothing and further enhance
speech quality. Experimental results demonstrate that MeanVC significantly outperforms existing zero-shot streaming VC systems, achieving superior conversion quality with higher efficiency and significantly fewer parameters. Audio demos and code are publicly available at https://aslp-lab.github.io/MeanVC.
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All authors Guobin Ma, Jixun Yao, Ziqian Ning, Yuepeng Jiang, Lingxin Xiong, Lei Xie, Pengcheng Zhu
Audio and Speech Processing
DialoSpeech: Dual-Speaker Dialogue Generation with LLM and Flow Matching
Hanke Xie, Dake Guo, Chengyou Wang et al. (+8 more)
Recent advances in text-to-
speech (TTS) synthesis, particularly those leveraging large
language models (LLMs), have significantly improved expressiveness and naturalness. However, generating human-like, interactive dialogue
speech remains challenging. Current systems face limitations due to the scarcity of dual-track data and difficulties in achieving naturalness, contextual coherence, and interactional dynamics, such as turn-taking, overlapping
speech, and speaker consistency, in multi-turn conversations. To address these challenges, we propose DialoSpeech, a dual-track architecture combining a large
language model with Chunked Flow Matching for expressive, human-like dialogue
speech synthesis. DialoSpeech generates natural multi-turn conversations with coherent speaker turns and natural overlaps, supporting both Chinese and English and cross-lingual
speech synthesis. We introduce a data processing pipeline to construct dual-track dialogue
datasets, facilitating scalable training and experimental validation. Experiments show that our model outperforms baselines, offering a solution for generating human-like spoken dialogues. Audio samples are available at https://tiamojames.github.io/DialoSpeech
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All authors Hanke Xie, Dake Guo, Chengyou Wang, Yue Li, Wenjie Tian, Xinfa Zhu, Xinsheng Wang, Xiulin Li, Guanqiong Miao, Bo Liu, Lei Xie
Systems and Control
Learning to Mitigate Post-Outage Load Surges: A Data-Driven Framework for Electrifying and Decarbonizing Grids
Wenlong Shi, Dingwei Wang, Liming Liu et al. (+1 more)
Electrification and decarbonization are transforming power system demand and recovery dynamics, yet their implications for post-outage load surges remain poorly understood. Here we analyze a metropolitan-scale heterogeneous
dataset for Indianapolis comprising 30,046 feeder-level outages between 2020 and 2024, linked to smart meters and submetering, to quantify the causal impact of electric vehicles (EVs), heat pumps (HPs) and distributed energy resources (DERs) on restoration surges. Statistical analysis and causal forest inference demonstrate that rising penetrations of all three assets significantly increase surge ratios, with effects strongly modulated by restoration timing, outage duration and weather conditions. We develop a component-aware multi-task
Transformer estimator that disaggregates EV, HP and DER contributions, and apply it to project historical outages under counterfactual 2035 adoption pathways. In a policy-aligned pathway, evening restorations emerge as the binding reliability constraint, with exceedance probabilities of 0.057 when 30% of system load is restored within the first 15 minutes. Mitigation measures, probabilistic EV restarts, short thermostat offsets and accelerated DER reconnection, reduce exceedance to 0.019 and eliminate it entirely when 20% or less of system load is restored. These results demonstrate that transition-era surges are asset-driven and causally linked to electrification and decarbonization, but can be effectively managed through integrated operational strategies.
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All authors Wenlong Shi, Dingwei Wang, Liming Liu, Zhaoyu Wang
Systems and Control
Underground Power Distribution System Restoration Using Inverter Based Resources
Wenlong Shi, Hongyi Li and Zhaoyu Wang
Underground power distribution systems (PDSs) are increasingly deployed in urban areas. The integration of smart devices including smart switchgears, pad-mounted distribution
transformers and inverter-based resources (IBRs) enhance system resilience, however simultaneously introducing unique challenges. The challenges include inrush currents caused by trapped charges in underground cables, ferroresonance in distribution
transformers during energization, and three-phase load imbalance resulting from single-phase underground laterals. To address these issues, this paper proposes an underground PDS restoration framework using IBRs. Firstly, an underground cable energization model is developed to quantify inrush current by analyzing voltage differences across both switchgear terminals. Secondly, a distribution
transformer energization model is proposed to evaluate ferroresonance using Q-factor constraints based on underground cable capacitance and damping resistance. Thirdly, a phase-swapping model is proposed to improve load balancing by dynamically reassigning lateral-phase connections through smart switchgears. The proposed models are further integrated into a mixed-integer nonlinear programming (MINLP) formulation to maximize the total weighted restored load while constraining inrush currents, ferroresonance, and phase imbalance. To address the nonlinearity induced by impedance
matrix reordering during phase swapping, a permutation-based linearization technique is proposed. Finally, case studies on an underground PDS established based on IEEE 123-Node Test Feeder validate the effectiveness of the proposed strategy in improving uderground PDS restoration performance.
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Systems and Control · Cross-listed from quant-ph
Quantum memory optimisation using finite-horizon, decoherence time and discounted mean-square performance criteria
Igor G. Vladimirov, Ian R. Petersen and Guodong Shi
This paper is concerned with open
quantum memory systems for approximately retaining
quantum information, such as initial dynamic variables or
quantum states to be stored over a bounded time interval. In the Heisenberg picture of
quantum dynamics, the deviation of the system variables from their initial values lends itself to closed-form computation in terms of tractable moment dynamics for open
quantum harmonic oscillators and finite-level
quantum systems governed by linear or quasi-linear Hudson-Parthasarathy
quantum stochastic differential equations, respectively. This tractability is used in a recently proposed optimality criterion for varying the system parameters so as to maximise the
memory decoherence time when the mean-square deviation achieves a given critical threshold. The
memory decoherence time maximisation approach is extended beyond the previously considered low-threshold asymptotic approximation and to Schrödinger type mean-square deviation functionals for the reduced system state governed by the Lindblad master equation. We link this approach with the minimisation of the mean-square deviation functionals at a finite time horizon and with their discounted version which quantifies the averaged performance of the
quantum system as a temporary
memory under a Poisson flow of storage requests.
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Systems and Control
CPU- and GPU-Based Parallelization of the Robust Reference Governor
Hamid R. Ossareh, William Shayne and Samuel Chevalier
Constraint management is a central challenge in modern control systems. A solution is the Reference Governor (RG), which is an add-on strategy to pre-stabilized feedback control systems to enforce state and input constraints by shaping the reference command. While robust formulations of RG exist for linear systems, their extension to nonlinear systems is often computationally intractable. This paper develops a scenario-based robust RG formulation for nonlinear systems and investigates its parallel implementation on multi-core CPUs and CUDA-enabled GPUs. We analyze the computational structure of the
algorithm, identify parallelization opportunities, and implement the resulting schemes on modern parallel hardware. Benchmarking on a nonlinear hydrogen fuel
cell model demonstrates order-of-magnitude speedups (by as much as three orders of magnitude) compared to sequential implementations.
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