Instance-level change detection in 3D scenes presents significant challenges, particularly under uncontrolled conditions without labeled image pairs, varying camera poses, or restricted lighting. This paper addresses this challenge by developing a novel approach to detect changes in real-world scenarios. Leveraging 4D Gaussians to embed multiple images into 3D Gaussian distributions, our method enables the rendering of two coherent image sequences. By segmenting each image and assigning a unique identifier to each instance, we can efficiently identify changed instances through ID comparison. Additionally, we utilize change maps and classification encodings to categorize the 4D Gaussians as changed or unchanged, allowing for the rendering of a comprehensive change map from any view direction. Through extensive experiments on various instance-level change detection datasets, our method demonstrates significant improvements in detection accuracy over state-of-the-art methods like C-NERF and CYWS-3D, particularly in scenarios with large lighting variations.

Semi-supervised change detection (SSCD) utilizes partially labeled data and abundant unlabeled data to detect differences between multi-temporal remote sensing images. The mainstream SSCD methods based on consistency regularization have limitations. They perform perturbations mainly at a single level, restricting the utilization of unlabeled data and failing to fully tap its potential. In this paper, we introduce a novel Gate-guided Two-level Perturbation Consistency regularization-based SSCD method (GTPC-SSCD). It simultaneously maintains strong-to-weak consistency at the image level and perturbation consistency at the feature level, enhancing the utilization efficiency of unlabeled data. Moreover, we develop a hardness analysis-based gating mechanism to assess the training complexity of different samples and determine the necessity of performing feature perturbations for each sample. Through this differential treatment, the network can explore the potential of unlabeled data more efficiently. Extensive experiments conducted on six benchmark CD datasets demonstrate the superiority of our GTPC-SSCD over seven state-of-the-art methods.

Modeling the dynamic interactions between users and items on knowledge graphs is crucial for improving the accuracy of recommendation. Although existing methods have made great progress in modeling the dynamic knowledge graphs for recommendation, they usually only consider the mutual influence between users and items involved in the interactions, and ignore the influence propagation from the interacting nodes (i.e., users and items) on dynamic knowledge graphs. In this article, we propose an influence propagation-enhanced deep co-evolutionary method for recommendation, which can capture not only the direct mutual influence between interacting users and items but also influence propagation from multiple interacting nodes to their high-order neighbors at the same time on the dynamic knowledge graph. Specifically, the proposed model consists of two main components: the direct mutual influence component and the influence propagation component. The former captures direct interaction influence between the interacting users and items to generate the effective representations for them. The latter refines their representations via aggregating the interaction influence propagated from multiple interacting nodes. In this process, a neighbor selection mechanism is designed for selecting more effective propagation influence, which can significantly reduce the computational cost and accelerate the training. Finally, the refined representations of users and items are used to predict which item the user is most likely to interact with. The experimental results on three real-world datasets illustrate that the effectiveness and robustness of PIDKG outperform all state-of-the-art baselines and the efficiency of it is faster than most comparative baselines.

Change detection (CD) is to decouple object changes (i.e., object missing or appearing) from background changes (i.e., environment variations) like light and season variations in two images captured in the same scene over a long time span, presenting critical applications in disaster management, urban development, etc. In particular, the endless patterns of background changes require detectors to have a high generalization against unseen environment variations, making this task significantly challenging. Recent deep learning-based methods develop novel network architectures or optimization strategies with paired-training examples, which do not handle the generalization issue explicitly and require huge manual pixel-level annotation efforts. In this work, for the first attempt in the CD community, we study the generalization issue of CD from the perspective of data augmentation and develop a novel weakly supervised training algorithm that only needs image-level labels. Different from general augmentation techniques for classification, we propose the background-mixed augmentation that is specifically designed for change detection by augmenting examples under the guidance of a set of background changing images and letting deep CD models see diverse environment variations. Moreover, we propose the augmented & real data consistency loss that encourages the generalization increase significantly. Our method as a general framework can enhance a wide range of existing deep learning-based detectors. We conduct extensive experiments in two public datasets and enhance four state-of-the-art methods, demonstrating the advantages of our method. We release the code at https://github.com/tsingqguo/bgmix.

KG-to-text generation models aim to generate a natural language text with one or more sentences from input knowledge graphs (KGs). Recent models use either entity-level or word-level graphs as input data to generate texts. The Entity-level graph provides the relations between entities but neglects the relations between words within a single entity and different entities. In contrast, a word-level graph can better consider the rich semantic relations among words but can fail to capture the relations between entities. This paper proposes a novel graph-to-sequence model that encodes both entity-level and word-level KGs to enhance node representations and investigates different decoder architectures to integrate contextualized representations of words and entities effectively. Automatic and human evaluations demonstrate that our method outperforms previous single-granularity methods on two popular graph-to-text benchmarks.

Keyphrases can concisely describe the high-level topics discussed in a document that usually possesses hierarchical topic structures. Thus, it is crucial to understand the hierarchical topic structures and employ it to guide the keyphrase identification. However, integrating the hierarchical topic information into a deep keyphrase generation model is unexplored. In this paper, we focus on how to effectively exploit the hierarchical topic to improve the keyphrase generation performance (HTKG). Specifically, we propose a novel hierarchical topic-guided variational neural sequence generation method for keyphrase generation, which consists of two major modules: a neural hierarchical topic model that learns the latent topic tree across the whole corpus of documents, and a variational neural keyphrase generation model to generate keyphrases under hierarchical topic guidance. Finally, these two modules are jointly trained to help them learn complementary information from each other. To the best of our knowledge, this is the first attempt to leverage the neural hierarchical topic to guide keyphrase generation. The experimental results demonstrate that our method significantly outperforms the existing state-of-the-art methods across five benchmark datasets.

Abstract Change detection (CD) is a fundamental problem that aims at detecting changed objects from two observations. Previous CNN‐based CD methods detect changes through multi‐scale deep convolutional features extracted from two images. However, we find that change always occurs in the ‘Query’ image for fixed cameras. This condition means that changes can be detected in advance from a single image with a coarse change. In this paper, we propose an efficient CD method to detect precise changes from the change image. First, a change image selector is designed to identify the image containing changes. Second, a coarse change prior map generator is proposed to generate coarse change prior to indicate the position of changes. Then, we introduce a simple multi‐scale CD module to refine the coarse change detection. As only one image is used in the multi‐scale CD module, our method is more efficient in training and testing than other compared methods. Numerous experiments have been conducted to analyse the effectiveness of the proposed method. Experimental results show that the proposed method achieves superior detection performance and higher speed than other compared CD methods.

Emotion analysis of on-line user generated textual content is important for natural language processing and social media analytics tasks. Most of previous emotion analysis approaches focus on identifying users’ emotional states from text by classifying emotions into one of the finite categories, e.g., joy, surprise, anger and fear. However, there exists ambiguity characteristic for the emotion analysis, since a single sentence can evoke multiple emotions with different intensities. To address this problem, we introduce emotion distribution learning and propose a multi-task convolutional neural network for text emotion analysis. The end-to-end framework optimizes the distribution prediction and classification tasks simultaneously, which is able to learn robust representations for the distribution dataset with annotations of different voters. While most work adopt the majority voting scheme for the ground truth labeling, we also propose a lexiconbased strategy to generate distributions from a single label, which provides prior information for the emotion classification. Experiments conducted on five public text datasets (i.e., SemEval, Fairy Tales, ISEAR, TEC, CBET) demonstrate that our proposed method performs favorably against the state-of-the-art approaches.

Traditional supervised keyphrase extraction models depend on the features of labelled keyphrases while prevailing unsupervised models mainly rely on structure of the word graph, with candidate words as nodes and edges capturing the co-occurrence information between words. However, systematically integrating all these multidimensional heterogeneous information into a unified model is relatively unexplored. In this paper, we focus on how to effectively exploit multidimensional information to improve the keyphrase extraction performance (MIKE). Specifically, we propose a random-walk parametric model, MIKE, that learns the latent representation for a candidate keyphrase that captures the mutual influences among all information, and simultaneously optimizes the parameters and ranking scores of candidates in the word graph. We use the gradient-descent algorithm to optimize our model and show the comprehensive experiments with two publicly-available WWW and KDD datasets in Computer Science. Experimental results demonstrate that our approach significantly outperforms the state-of-the-art graph-based keyphrase extraction approaches.

Modelling users’ dynamic preference for personalized temporal recommendation has been a hot research topic. Traditional dynamic recommendation models divide a user’s interaction history into fixed-sized windows to learn the user’s evolving preference. This strategy however worsens the issue of data sparsity in that some sessions may have very little or even no interaction for preference inference. To alleviate the data sparsity issue and avoid errors due to data imputation that is commonly adopted by existing models, a novel session-based dynamic recommendation model that divides a user’s interaction history with dynamic window size is proposed. An empirical study on the users’ activity life cycles using real-world dataset is conducted to demonstrate the nonuniformness and aggregation of the users’ behavior patterns on the time dimension. Based on the study, a user’s interaction history is divided with dynamic temporal window size by using dynamic clustering. The user’s evolving profile is then constructed by modeling her preference in each session using Latent Dirichlet Allocation (LDA) and a time sensitive weighting scheme. Our dynamic model is designed for two major recommendation tasks: (1) top-N recommendation, which is provided by measuring the relevance of probabilistic topic distribution between the user’s profile in the next temporal domain and each candidate item, (2) rating prediction that is achieved by finding K nearest user/item neighbors based the similarity of probabilistic topic distribution between users/items. Extensive empirical experiments over two real datasets demonstrate the effectiveness and superiority of our method by comparing to representative temporal dynamic methods.