This paper investigates a multi-satellite cooperative covert satellite communication (SatCom) scheme, where a positive covert rate is achieved in ultra-dense low Earth orbit (LEO) satellite constellations by exploiting both interference and directional uncertainty. Specifically, interference arises from aggregate sidelobe leakage from other satellite transmissions, while directional uncertainty stems from the random selection of the transmitting satellite among multiple accessible ones. To this end, we first propose a LEO satellite network model and formulate the corresponding hypothesis testing problem for the cooperative covert SatCom scheme. The power distribution of the aggregate interference is quantified and approximated using stochastic geometry. Next, by analyzing the detection error probability and outage probability under the impact of aggregate interference, we derive an approximate covert capacity expression for the case of a single accessible satellite, which maintains a positive covert rate even as the slot length approaches infinity. Furthermore, by leveraging directional uncertainty through hiding the signal’s angle of arrival, we analyze the multi-satellite cooperative covert SatCom scheme, leading to a concise approximate expression that reveals significant covert capacity improvement. Numerical simulations are performed to verify the superiority of the proposed scheme, suggesting that a positive covert capacity can be achieved with interference uncertainty and significantly enhanced by directional uncertainty as the number of satellites increases.

With the growing adoption of time-series anomaly detection (TAD) technology, numerous studies have employed deep learning-based detectors to analyze time-series data in the fields of Internet services, industrial systems, and sensors. The selection and optimization of anomaly detectors strongly rely on the availability of an effective evaluation for TAD performance. Since anomalies in time-series data often manifest as a sequence of points, conventional metrics that solely consider the detection of individual points are inadequate. Existing TAD evaluators typically employ point-based or event-based metrics to capture the temporal context. However, point-based evaluators tend to overestimate detectors that excel only in detecting long anomalies, while event-based evaluators are susceptible to being misled by fragmented detection results. To address these limitations, we propose OIPR1, a novel TAD evaluator with area-based metrics. It models the process of operators receiving detector alarms and handling anomalies, utilizing area under the operator interest curve to evaluate TAD performance. Furthermore, we build a special scenario dataset to compare the characteristics of different evaluators. Through experiments conducted on the special scenario dataset and five real-world datasets, we demon-strate the remarkable performance of OIPR in extreme and complex scenarios. It achieves a balance between point and event perspectives, overcoming their primary limitations and offering applicability to broader situations.

Human experts typically integrate numerical and textual multimodal information to analyze time series. However, most traditional deep learning predictors rely solely on unimodal numerical data, using a fixed-length window for training and prediction on a single dataset, and cannot adapt to different scenarios. The powered pre-trained large language model has introduced new opportunities for time series analysis. Yet, existing methods are either inefficient in training, incapable of handling textual information, or lack zero-shot forecasting capability. In this paper, we innovatively model time series as a foreign language and construct ChatTime, a unified framework for time series and text processing. As an out-of-the-box multimodal time series foundation model, ChatTime provides zero-shot forecasting capability and supports bimodal input/output for both time series and text. We design a series of experiments to verify the superior performance of ChatTime across multiple tasks and scenarios, and create four multimodal datasets to address data gaps. The experimental results demonstrate the potential and utility of ChatTime.

Recent progress in video anomaly detection assumes that anomalies cannot be effectively reconstructed because they remain unseen during training. However, we observe that most existing methods excessively rely on appearance features, resulting in the accurate reconstruction of anomalies with subtle short-term appearance variations, which we refer to as appearance confusion. Meanwhile, many approaches fail to exploit sufficient semantic distinction, resulting in motion confusion for anomalies with motion patterns similar to normal ones. In this paper, we propose a masked self-supervised learning-based framework, which effectively addresses the two confusions by exploring context-aware motion patterns and discriminative semantic normality representations. First, we introduce reconstructing multi-pattern masked spatiotemporal information to motivate the model to capture motion patterns that focus on long-term context. Then, we design a semantic noise separation network to address motion confusion, facilitating the construction of semantic normality boundaries through semantic-aware separation. Extensive experiments on the Avenue and ShanghaiTech datasets validate the effectiveness of our proposed method.

Accurate forecasting of time series is crucial for many applications in the real world. Conventional methods primarily rely on statistical analysis of historical data, often leading to overfitting and failing to account for background information and constraints imposed by external events. Therefore, introducing large language models (LLMs) with robust textual capabilities holds significant potential. However, due to the inherent limitations of LLMs in handling numerical data, they do not exhibit advantages in precise numerical prediction tasks. Therefore, we propose a framework to integrate LLMs with conventional methods synergistically. Rather than directly outputting numerical predictions, we leverage the capabilities of the LLMs to generate textual temporal patterns, thereby fully utilizing their inherent knowledge and reasoning abilities. Additionally, we introduce a memory network designed to decode these textual representations into a format that numerical models can effectively interpret. This approach not only capitalizes on the strengths of the LLM in text processing but also bridges the gap between textual and numerical data, enhancing the overall predictive performance of the model. Our experimental results demonstrate the framework's effectiveness, achieving state-of-the-art performance on various benchmark datasets.

Synthetic images serve as a promising alternative to real images in 3D hand pose estimation, providing accurate annotations at a lower cost. However, the domain gap between real and synthetic images constrains the generalization ability of hand pose estimation trained on synthetic data. Previous methods rely on Generative Adversarial Networks (GANs) for domain translation; however, they fail to achieve realistic depth synthesis due to instability and limited image quality. Diffusion models provide high-quality synthesis due to their stability and controllability. However, existing methods often ignore the 3D structure awareness in hand image generation. In this paper, we propose a Dual-Branch 3D Spatial-Aware Latent Diffusion (DSW-LD) for realistic depth image generation. The Global Structure Module (GSM) and the Local Geometry Module (LGM) complement each other, with GSM capturing global spatial structure through coarse-grained 3D joint features and LGM focusing on local geometric details using fine-grained 3D mesh representations. To maintain the global structure consistency, we adopt a layer-aware injection mechanism that enables the model to adaptively learn the optimal representation from fused 2D latent representations and 3D joint features. To explicitly align 3D and 2D features of local regions and enhance the flexibility of feature matching, we design a dynamic depth-aware interpolation to project 3D mesh features into 2D image space. Both quantitative and qualitative experimental results demonstrate the superiority of our method over the state-of-the-arts for realistic depth synthesis. Compared to training only on real depth images, our method enables the hand pose estimator to achieve significantly better performance with our synthetic data and less real data (10%).

Multivariate time-series (MTS) classification tasks play a key role in data-driven applications spanning healthcare, finance, and mobile communication. As MTS data are typically collected from multiple interdependent sensors, the resulting temporal patterns inherently reflect the characteristics of the underlying sensing systems. Despite this connection, conventional MTS classification models predominantly focus on raw time-series data while disregarding valuable sensor-specific prior knowledge, which fundamentally constrains their classification accuracy. The emergence of large language models (LLMs) has encoded extensive sensor-related knowledge within their parameter spaces. However, effectively harnessing such knowledge to enhance MTS classification networks remains an open challenge. To address this, we propose Foresail, a status-guided neural framework that bridges this gap through systematic integration of LLM-derived sensor knowledge via the status relationship matrix and fine-grained status labels. Foresail can be seamlessly integrated with existing MTS networks to optimize performance and generate interpretable intermediate results. Experiments on irregularly and regularly sampled MTS data demonstrate that Foresail outperforms state-of-the-art approaches, achieving a notable improvement in F1-score of up to 10.9% compared to the basic MTS network.

Large Vision-Language Models (LVLMs) pretrained on large-scale multimodal data have shown promising capabilities in Video Anomaly Detection (VAD). However, their ability to reason about abnormal events based on scene semantics remains underexplored. In this paper, we investigate LVLMs’ behavior in VAD from a visual-textual co-occurrence perspective, focusing on whether their decisions are driven by statistical shortcuts between visual instances and textual phrases. By analyzing visual-textual co-occurrence in pretraining data and conducting experiments under different data settings, we reveal a hallucination phenomenon: LVLMs tend to rely on co-occurrence patterns between visual instances and textual phrases associated with either normality or abnormality, leading to incorrect predictions when these high-frequency objects appear in semantically mismatched contexts. To address this issue, we propose VAD-DPO, a direct preference optimization method supervised with counter-example pairs. By constructing visually similar but semantically contrasting video clips, VAD-DPO encourages the model to align its predictions with the semantics of scene rather than relying on co-occurrence patterns. Extensive experiments on six benchmark datasets demonstrate the effectiveness of VAD-DPO in enhancing both anomaly detection and reasoning performance, particularly in scene-dependent scenarios.

To fully leverage communication resources for pervasive sensing within existing architectures, it is crucial to enable perception through the use of transmitted data. Unlike traditional waveform designs that focus exclusively on modulation, this paper introduces a novel approach starting from the information bit level. By applying controlled perturbations, approximate codewords are aligned with deterministic optimization waveforms, effectively suppressing sidelobe levels and enhancing data-driven sensing capabilities. Additionally, to address decoding impairments caused by these perturbations, we propose a closed-loop reception algorithm that progressively removes residual disturbances while maintaining decoding accuracy. Simulations confirm the algorithm’s effectiveness in balancing communication and sensing performance. Compared to current time-division processing technologies, such as 5G frame structure perception based on reference signals, the proposed waveforms more effectively resolves the trade-off between communication and sensing.

With the rapid development of next-generation networks, the highly heterogeneous and dynamic nature of networks poses significant challenges for automated network management. Autonomous Network (AN), as a new network paradigm, aims to provide customers with a zero-wait, zero-touch, and zero-fault experience. AN facilitates network management through intent-driven interactions and provides on-demand resource orchestration and service scheduling. However, accurately translating user intents into commands and allocating resources on demand for services remain significant challenges for AN. Therefore, this paper proposes IAN, an intent-based AN framework guided by the Large Language Model (LLM). In the intent translation phase, IAN introduces RAG to enhance command generation quality by retrieving from manuals. In the resource allocation phase, the method utilizes LLM to analyze service characteristics, thereby guiding the training and inference of the resource allocation model to effectively distribute resources uniformly across emerging services. Experimental results demonstrate that IAN improves performance by 52.66% in intent translation tasks and increases overall gain by 33.57% in resource allocation tasks compared to other models.

Intent-Based Networking (IBN) represents an emerging network management concept that is designed to fulfill user service requirements through automation. At its core, IBN is capable of translating user intent into network policies, thereby enabling automated configuration and management. However, the application of IBN has been limited by challenges associated with automation and intelligence. The recent widespread adoption of Large Language Model (LLM) has partially mitigated these issues. Nonetheless, hardware heterogeneity and high dynamic networks remain significant challenges for IBN: (i) Devices from different vendors are challenging to manage uniformly; (ii) Aligning service demands with rapidly changing network status is difficult. To address these challenges, we propose LIT, a framework of LLM-empowered Intent Translation with manual guidance. LIT incorporates Retrieval-Augmented Generation (RAG) to reference hardware manuals and enhance the generation results of LLMs. To reduce noise from retrieval results, we optimized the general RAG process. Additionally, LIT introduces MoE (Mixture of Experts) to adjust parameter values according to network status by synthesizing results from multiple expert models. Experiments demonstrate that LIT alleviates the challenges faced by IBN, achieving a 57.5% improvement in F1 score compared to the baseline.

Federated learning (FL) has recently been applied to the parameter-efficient fine-tuning (PEFT) of large language models (LLMs). While promising, client resource heterogeneity has imposed the challenge of the "bucket effect" to FL, where model configuration must cater to the client with the fewest resources. To tackle this issue, heterogeneous low-rank adaptation (LoRA) has recently emerged in FL, which enables clients to do local fine-tuning with different LoRA ranks. However, existing works in this area typically adopt zero-padding, stacking, or singular value decomposition (SVD) for LoRA aggregation, which often incur precision loss or significant overhead, limiting their practicality. In this article, we propose ECLoRA, a novel method for federated fine-tuning with heterogeneous LoRA settings across clients. ECLoRA employs randomized SVD (RSVD) to dramatically reduce aggregation overhead while introducing an error compensation (EC) mechanism that incorporates the decomposition error from previous rounds to improve aggregation precision. Extensive experiments on four widely used foundation models across six public tasks demonstrate the effectiveness of ECLoRA. Specifically, ECLoRA is: (1) accurate, significantly improving the final model performance; (2) fast, accelerating convergence with an average speedup of $1.54\times $ to $3.01\times $ ; and (3) practical, reducing aggregation time by approximately $40\times $ compared to classical SVD.

Logs record crucial information about runtime status of software system, which can be utilized for anomaly detection and fault diagnosis. However, techniques struggle to perform effectively when dealing with interleaved logs and entities that influence each other. Although manually specifying a grouping field for each dataset can handle the single grouping scenario, the problems of multiple and heterogeneous grouping still remain unsolved. To break through these limitations, we first design a log semantic association mining approach to convert log sequences into Log-Entity Graph, and then propose a novel log anomaly detection model named Lograph. The semantic association can be utilized to implicitly group the logs and sort out complex dependencies between entities, which have been overlooked in existing literature. Also, a Heterogeneous Graph Attention Network is utilized to effectively capture anomalous patterns of both logs and entities, where Log-Entity Graph serves as a data management and feature engineering module. We evaluate our model on real-world log datasets, comparing with nine baseline models. The experimental results demonstrate that Lograph can improve the accuracy of anomaly detection, especially on the datasets where entity relationships are intricate and grouping strategies are not applicable.

This paper investigates covert communication in ultra-dense low Earth orbit (LEO) satellite systems, where the uncertainty of the aggregated interference formed by sidelobe leakages of satellite transmissions can be exploited to hide wireless signals from being detected by a warden. Specifically, we first propose a LEO satellite network model and the corresponding hypothesis testing problem for the covert satellite communication scheme, where the power distribution of the aggregated interference is quantified and then approximated by using stochastic geometry. After that, to analyze the impact of the aggregated interference, the covert transmission problem under constraints of the detection probability at Willie and the outage probability at Bob is formulated, where the achievable covert capacity is analyzed by considering different number of satellites N. Finally, numerical simulations are performed to verify the derived analytical results, which demonstrate that the covert capacity initially increases as$N$increases, while it becomes approximately proportional to$1/\sqrt{N}$for sufficiently large N.

Accurate long-term viewport prediction in tile-based 360° video adaptive streaming helps pre-download tiles for a further future, thus establishing a longer buffer to cope with network fluctuations. Long-term viewport motion is mainly influenced by Historical viewpoint Trajectory (HT) and Video Content information (VC). However, HT and VC are difficult to align in space due to their different modalities, and their relative importance in viewport prediction varies across prediction time steps. In this paper, we propose STAR-VP, a model that fuses HT and VC in a Space-aligned and Time-vARying manner for Viewport Prediction. Specifically, we first propose a novel saliency representation salxyz and a Spatial Attention Module to solve the spatial alignment of HT and VC. Then, we propose a two-stage fusion approach based on Transformer and gating mechanisms to capture their time-varying importance. Visualization of attention scores intuitively demonstrates STAR-VP's capability in space-aligned and time-varying fusion. Evaluation on three public datasets shows that STAR-VP achieves state-of-the-art accuracy for long-term (2-5s) viewport prediction without sacrificing short-term (<1s) prediction performance.

Learning multiple proxy tasks is a popular training strategy in semi-supervised video anomaly detection. However, the traditional method of learning multiple proxy tasks simultaneously is prone to suboptimal solutions, and simply executing multiple proxy tasks sequentially cannot ensure continuous performance improvement. In this paper, we thoroughly investigate the impact of task composition and training order on performance enhancement. We find that ensuring continuous performance improvement in multi-task learning requires different but continuous optimization objectives in different training phases. To this end, a training strategy based on progressive learning is proposed to enhance the multi-task learning in VAD. The learning objectives of the model in previous phases contribute to the training in subsequent phases. Specifically, we decompose video anomaly detection into three phases: perception, comprehension, and inference, continuously refining the learning objectives to enhance model performance. In the three phases, we perform the visual task, the semantic task and the open-set task in turn to train the model. The model learns different levels of features and focuses on different types of anomalies in different phases. Extensive experiments demonstrate the effectiveness of our method, highlighting that the benefits derived from the progressive learning transcend specific proxy tasks.

Network anomaly detection provides a reliable and stable service to detect faults and prevent security attacks effectively. However, existing detection methods still encounter many challenges. The supervised learning method is unsuitable because the anomaly samples are seriously sparse and hard to label. Unsupervised learning, as a promising method, is widely used while the discriminative features are ignored when reconstructing from the normal feature space. This paper proposes a novel probability correlation learning based on autoencoder called PCDetect, a semi-supervised learning method. Since we assumed the anomaly samples deviate from the distribution of normal samples, approximating the distribution of original data is proposed as an efficient preprocessing methodology to capture the discriminative features. Moreover, an encoder-decoder neural network associated with the proposed loss function is designed to learn the low-dimensional feature representation from raw data and constrain the latent representation to follow different referenced distributions based on a few anomaly labels. In this way, The correlation of the referenced distribution and the reconstruction of latent representation will be used to quantify the probability of anomaly. Extensive experiments are conducted on two public real-world datasets, NSL-KDD and UNSW-NB15. Results show the proposed PCDetect can efficiently cope with the imbalance and high-dimensional issues compared with several popular supervised learning methods, significantly improve the accuracy, and reduce the false rate as a whole compared with unsupervised learning.

Aspect term extraction and opinion word extraction are two fundamental subtasks of aspect-based sentiment analysis. The internal relationship between aspect terms and opinion words is typically ignored, and information for the decision-making of buyers and sellers is insufficient. In this paper, we explore an aspect–opinion pair extraction (AOPE) task and propose a Question-Driven Span Labeling (QDSL) model to extract all the aspect–opinion pairs from user-generated reviews. Specifically, we divide the AOPE task into aspect term extraction (ATE) and aspect-specified opinion extraction (ASOE) subtasks; we first extract all the candidate aspect terms and then the corresponding opinion words given the aspect term. Unlike existing approaches that use the BIO-based tagging scheme for extraction, the QDSL model adopts a span-based tagging scheme and builds a question–answer-based machine-reading comprehension task for an effective aspect–opinion pair extraction. Extensive experiments conducted on three tasks (ATE, ASOE, and AOPE) on four benchmark datasets demonstrate that the proposed method significantly outperforms state-of-the-art approaches.

In this paper, we introduce a continuous bitrate control and latency control model for the Live Video Streaming Challenge. Our model is based on Deep Deterministic Policy Gradient, popular on continuous control tasks. Simultaneously, it can take a fine-grained control through continuous control and does not need to discrete the continuous "latency limit", which is a buffer threshold to minimize end-to-end delay by frame skipping. In all considered live video scenarios, our model can provide a better quality of experience with improvements in average QoE of 3.6% than DQN which discrete the "latency limit". Additionally, challenge results show the effectiveness and applicability of the proposed model, which achieved top performance in 3 different networks that include high, low and oscillating throughput, and ranked the second place in the network with medium throughput.

Existing rateless codes have a very low intermediate symbol recovery rate. Therefore, a new analysis method named iterative and small degree first (I‐SDF) is presented for the design of optimised partial recovery Luby transform codes (PR‐LTC) in this study. On the basis of I‐SDF, the required number of encoded symbols with degree d in each decoding step is calculated by an iterative optimisation algorithm. Under the proposed design, R ( R < k ) input symbols can be recovered from as few encoded symbols as possible in PR‐LTC with message length k . Furthermore, multiple PR‐LTC (M‐PR‐LTC) is proposed to recover several partial recovery point (PRPs) efficiently. The analysis process is divided into multiple stages, and the required number of encoded symbols with degree d in each decoding step is calculated by a cross‐stage iterative optimisation algorithm. In addition, the interaction of each stage is adjusted by introducing a weight for each PRP. The PR‐LTC and M‐PR‐LTC are evaluated and compared with the existing schemes. The simulation results demonstrate that PR‐LTC and M‐PR‐LTC outperform other existing schemes in terms of average overhead, average degree of encoded symbols, memory usage, bit error rate and energy consumption.

In this study, the design of improved Luby transform codes with decreasing ripple size (LTC‐DRS) with feedback is presented. Under the proposed design, a new degree distribution algorithm named generalised degree distribution algorithm (GDDA) is proposed, which can achieve arbitrary ripple size revolution accurately. On the basis of GDDA, an accurate ripple size revolution based on binomial fitting is proposed, which can keep the ripple size to a suitable value throughout the decoding process. Furthermore, the authors introduce the feedback and propose a shifted ripple size revolution to diversify the degree values. The improved LTC‐DRS with feedback is evaluated and compared with the existing schemes. The simulation results demonstrate that it outperforms other existing schemes in terms of average overhead, average degree of encoded symbols, memory usage and energy consumption.

Due to the conflicts existing in the route objectives of overlay routing and traffic engineering, the interaction between the two selfish players may converge to an inefficient Nash equilibrium point, even if the better choice may exist. We formulate the interaction as an infinitely repeated two-player game, where overlay routing aims to minimize the average latency of overlay users and traffic engineering aims to minimize the maximum link utilization of overall network. The whole interaction process could be divided into two stages - learning stage and practice stage. The former collects the historical information and finds the best point with a simple learning algorithm, then the latter uses this point as equilibrium point and converges to it. The simulation results show that both overlay routing and traffic engineering can converge to the win-win results, and the overall network can avoid the performance volatility from endless oscillations.