Shuang Liang

Artificial intelligence (AI)-driven positioning and tracking systems combine geometric trajectories with behavior understanding in smart-city, healthcare, and autonomous environments. Skeleton sequences provide compact, privacy-preserving motion geometry, but labeled data are costly, and coordinate-only self-supervision cannot recover object, scene, or interaction cues. Vision-language transfer can supply these cues, but instance-level targets remain sensitive to noisy crops, incomplete descriptions, and ambiguous actions. We propose CrossVLS, which is a cross-modal vision-language-guided framework that transfers semantic knowledge from red, green, and blue (RGB) frames and generated language descriptions to a skeleton encoder during pretraining while retaining skeleton-only inference. CrossVLS replaces noisy instance-level transfer with a shared prototype space: skeleton, RGB, and language features are softly assigned to a common prototype bank through balanced optimal transport, and the resulting assignments define semantic soft targets for contrastive learning. A full-batch progressive training schedule gradually increases cross-modal guidance without splitting the physical batch, preserving the support set used to construct semantic targets. Experiments on NTU RGB+D 60, NTU RGB+D 120, and PKU-MMD demonstrate strong performance under linear and semi-supervised evaluation using only the pretrained skeleton encoder at inference. These results show that prototype-mediated vision-language transfer can improve skeleton representations for the behavior-interpretation stage of positioning and tracking pipelines.

Compared with frequent pattern mining, sequential pattern mining emphasizes the temporal aspect and finds broad applications across various fields. However, numerous studies treat temporal events as single time points, neglecting their durations. Time-interval-related pattern (TIRP) mining is introduced to address this issue and has been applied to healthcare analytics, stock prediction, etc. Typically, mining all patterns is not only computationally challenging for accurate forecasting but also resource-intensive in terms of time and memory. Targeting the extraction of TIRPs based on specific criteria can improve data analysis efficiency and better align with customer pReferences. Therefore, this article proposes a novel algorithm called TaTIRP to discover targeted TIRP. In addition, we develop multiple pruning strategies to eliminate redundant extension operations, thereby enhancing performance on large-scale datasets. Finally, we conduct experiments on various real-world and synthetic datasets to validate the accuracy and efficiency of the proposed algorithm.

Compared to frequent pattern mining, sequential pattern mining emphasizes the temporal aspect and finds broad applications across various fields. However, numerous studies treat temporal events as single time points, neglecting their durations. Time-interval-related pattern (TIRP) mining is introduced to address this issue and has been applied to healthcare analytics, stock prediction, etc. Typically, mining all patterns is not only computationally challenging for accurate forecasting but also resource-intensive in terms of time and memory. Targeting the extraction of time-interval-related patterns based on specific criteria can improve data analysis efficiency and better align with customer preferences. Therefore, this paper proposes a novel algorithm called TaTIRP to discover Targeted Time-Interval Related Patterns. Additionally, we develop multiple pruning strategies to eliminate redundant extension operations, thereby enhancing performance on large-scale datasets. Finally, we conduct experiments on various real-world and synthetic datasets to validate the accuracy and efficiency of the proposed algorithm.

Human-Object Interaction (HOI) detection has seen substantial advances in recent years. However, existing works focus on the standard setting with ideal images and natural distribution, far from practical scenarios with inevitable distribution shifts. This hampers the practical applicability of HOI detection. In this work, we investigate this issue by benchmarking, analyzing, and enhancing the robustness of HOI detection models under various distribution shifts. We start by proposing a novel automated approach to create the first robustness evaluation benchmark for HOI detection. Subsequently, we evaluate more than 40 existing HOI detection models on this benchmark, showing their insufficiency, analyzing the features of different frameworks, and discussing how the robustness in HOI is different from other tasks. With the insights from such analyses, we propose to improve the robustness of HOI detection methods through: (1) a cross-domain data augmentation integrated with mixup, and (2) a feature fusion strategy with frozen vision foundation models. Both are simple, plug-and-play, and applicable to various methods. Our experimental results demonstrate that the proposed approach significantly increases the robustness of various methods, with benefits on standard benchmarks, too. The dataset and code will be released.

3-D action recognition become a fast-pacing field in recent years. However, traditional approaches have limitations. They either focus on modeling overly detailed yet redundant information by reconstructing the coordinates of each body joint. Alternatively, they treat actions as a whole, overlooking the spatial and temporal variations in the semantic locality of actions. To address these limitations, we propose representing long-term actions as contexts of short-term actions organized by locality-aware graphs. In our framework, we take the inspiration that the continuity of motion and pose variations generate higher correlations. These correlations occur among spatio-temporally adjacent joints. Built upon this, we craft short-term actions as embeddings using spatio-temporal graph convolutions. This graph-based encoding not only captures richer high-level semantics but also maintains an awareness of the topology. To capture long-term action dynamics effectively, we integrate a graph convolutional gated recurrent unit (GraphGRU) for the fusion of action embeddings. Additionally, we introduce the context-aware topological attention (CTA) mechanism. Positioned between embedding encoding and context aggregation phases, CTA amplifies the features of context-relevant nodes. Lastly, we create self-supervision by contrasting predicted embeddings with actual encoded embeddings. This approach explicitly learns changes in dynamics to obtain distinct embeddings. Empirical evaluations demonstrate that our approach outperforms mainstream unsupervised 3-D action recognition methods.

Visual relationships are crucial for visual perception and reasoning, and cover tasks like Scene Graph Generation, Human-Object Interaction, and object affordance. Despite significant efforts, this field still suffers from the following limitations: specialists for a specific task without considering similar ones, strict and complex task formulations with limited flexibility, and underexploited reasoning with language and knowledge. To solve these limitations, we seek to build a new framework, one model for all tasks, over Large Multimodal Models (LMMs). LMMs offer the potential of unifying tasks, flexible forms, and reasoning with language. However, they fail to handle visual relationship tasks well. We find the obstacles include the conflicts between different tasks and insufficient instance-level information. We solve these problems by reforming the data for LMMs, rather than architectures, considering their strong language-in language-out capability. We propose to disassemble tasks into simple and common sub-tasks, verbally estimate instance confidence, and augment instance diversity, all without additional modules. These strategies help us build a visual relationship generalist, RelationLMM, with a simple architecture. Exhaustive experiments demonstrate RelationLMM is strong, generalizable and flexible to different tasks, with one model and one suite of weight.