Next Point-of-Interest (POI) recommendation task focuses on mining user behavioral preference patterns from historical check-ins to provide personalized suggestions for the next destination. Existing methods primarily rely on shallow contextual information and handcrafted feature interactions to predict the next POI. However, the inherent sparsity and complexity of user mobility patterns limit the computational capacity of non-reasoning models to capture deep intent, while large language models (LLMs) perform suboptimally because they lack a deep understanding of semantic IDs (SIDs) when SIDs are trained separately. To address these limitations, we propose Think2Go, a novel generative next POI recommendation framework, which enhances the model's comprehension of SID representations and explores diverse spatial-temporal patterns via test-time computational scaling. We unify supervised fine-tuning (SFT) and reinforcement learning (RL)-based reasoning within a single architecture, enabling joint optimization of memorization and adaptive reasoning to better retain user behavior patterns while exploring diverse user preferences. To further calibrate policy optimization in adaptive reasoning, we propose two advantage weighting mechanisms that integrate (1) prompt epistemic uncertainty, estimated via kernel density methods to assess the spatial-temporal periodic pattern alignment between queries and user history, promoting increased exploration under high epistemic uncertainty; and (2) reward-informed advantage scaling, captured by normalizing rewards against their maxima to adapt update magnitudes, thereby improving training stability and mitigating overfitting to noisy signals. This joint calibration forms an implicit curriculum learning strategy, delivering fine-grained, instance-aware policy updates that prevent entropy collapse and support robust exploration. Extensive experiments conducted on three real-world datasets demonstrate that Think2Go exhibits strong generalization capabilities and enhances the LLM's understanding of SIDs.

Next Point-of-Interest (POI) prediction is important to various human mobility applications, such as route planning and location-based advertising. To address the spatial-temporal sparsity issues arising from users' irregular and inconsistent visit times to different POIs, multi-granular structures can be incorporated to enhance feature representation through hierarchical relationships. However, existing methods often fall short in capturing the comprehensive multi-granularity spatial-temporal correlations due to three primary limitations: (1) users' complex mobility patterns entangled in single trajectory data, (2) limited mobility patterns details due to independent modeling at each granularity, and (3) low inference efficiency in cascaded multi-granularity predictions. To tackle these challenges, we propose a novel approach that models transformations across different granularities in both spatial regions and temporal periods as a diffusion process, leading to the development of the Multi-Granularity Spatial-Temporal Diffusion Network (MGSTDN). In particular, this model adopts a multi-task architecture, where predictions at varying spatial-temporal granularities (i.e., different diffusion steps) are treated as distinct tasks. By employing a multi-granularity diffusion mechanism in both spatial and temporal dimensions, it captures more nuanced spatial-temporal correlations, enhancing the physical constraints and behavioral pattern dependencies across granularities. During the diffusion process's forward stage, coarser-grained regions and periods are derived based on fine-grained features. In the reverse stage, finer-grained regions and periods are recovered from coarse-grained features, guided by encoded historical trajectory information, until the next POI is determined. To improve computational efficiency, we introduce a multi-granularity mapping propagation matrix, enabling parallel computation and accelerating the prediction process across different granularities. We evaluated the effectiveness of MGSTDN through extensive experiments on three datasets, demonstrating significant improvements over existing methods.

Next point-of-interest (POI) recommendation is to explore the historical check-in sequence information in location-based social networks (LBSNs) to recommend the next location that he/she might be interested in. However, most previous methods used only limited information of unimodal data (i.e., check-in sequences), while some recent methods have attempted to explore multimodal data (e.g., textual content) but lacked sufficient interactions between geographic behavior patterns and content behavior patterns. In this work, we argue that users usually consider geographical trajectories and textual content interdependently to determine the next location to visit. To this end, we propose a novel cross-modal aggregation attention network (CMAAN), which interactively learns multiview representations from POI sequence and content sequence for predicting the next POI. Our approach models inter-modal interaction correlations, intra-modal sequence correlations, and intra-modal semantic correlations simultaneously to fully discover contextual potential relations along the trajectories. Specifically, the intra-modal semantic correlations are able to capture the variable location functionalities under different contextual relationships of cross-modal interaction information. Moreover, we apply the aggregation attention to adaptively aggregate multiview representations which represent the comprehensive hidden state of the next POI. Extensive experiments on two large-scale datasets clearly demonstrate that our CMAAN achieves state-of-the-art performance.

Next Point-of-Interest (POI) recommendation has been proven effective at utilizing sparse, intricate spatial-temporal trajectory data to recommend subsequent POIs to users. While existing methods commonly alleviate the problem of data sparsity by integrating spatial-temporal context information, POI category features, and social relationships, they largely overlook the fact that the trajectory sequences collected in the datasets are often incomplete. This oversight limits the model’s potential to fully leverage historical context. In light of this background, we propose Trajectory Data Augmentation with Uncertainty (TAU) for Next POI Recommendation. TAU is a general graph-based trajectory data augmentation method designed to complete user mobility patterns by marrying uncertainty estimation into the next POI recommendation task. More precisely, TAU taps into the global transition pattern graph to identify sets of intermediate nodes located between every pair of locations, effectively leveraging edge weights as transition probabilities. During trajectory sequence construction, TAU selectively prompts intermediate nodes, chosen based on their likelihood of occurrence as pseudo-labels, to establish comprehensive trajectory sequences. Furthermore, to gauge the certainty and impact of pseudo-labels on the target location, we introduce a novel confidence-aware calibration strategy using evidence deep learning (EDL) for improved performance and reliability. The experimental results clearly indicate that our TAU method achieves consistent performance improvements over existing techniques across two real-world datasets, verifying its effectiveness as the state-of-the-art approach to the task.

Multi-focus image fusion in wireless visual sensor networks (WVSN) is a process of fusing two or more images to obtain a new one which contains a more accurate description of the scene than any of the individual source images. In this letter, we propose an efficient algorithm to fuse multi-focus images or videos using discrete cosine transform (DCT) based standards in WVSN. The spatial frequencies of the corresponding blocks from source images are calculated as the contrast criteria, and the blocks with the larger spatial frequencies compose the DCT presentation of the output image. Experiments on plenty of pairs of multi-focus images coded in Joint Photographic Experts Group (JPEG) standard are conducted to evaluate the fusion performance. The results show that our fusion method improves the quality of the output image visually and outperforms the previous DCT based techniques and the state-of-art methods in terms of the objective evaluation.