Popularity bias occurs when popular items are recommended far more frequently than they should be, negatively impacting both user experience and recommendation accuracy. Existing debiasing methods mitigate popularity bias often uniformly across all users and only partially consider the time evolution of users or items. However, users have different levels of preference for item popularity, and this preference is evolving over time. To address these issues, we propose a novel method called CausalEPP (Causal Intervention on Evolving Personal Popularity) for taming recommendation bias, which accounts for the evolving personal popularity of users. Specifically, we first introduce a metric called Evolving Personal Popularity to quantify each user's preference for popular items. Then, we design a causal graph that integrates evolving personal popularity into the conformity effect, and apply deconfounded training to mitigate the popularity bias of the causal graph. During inference, we consider the evolution consistency between users and items to achieve a better recommendation. Empirical studies demonstrate that CausalEPP outperforms baseline methods in reducing popularity bias while improving recommendation accuracy.

In the field of multi-document summarization (MDS), transformerbased models have demonstrated remarkable success, yet they suffer an input length limitation.Current methods apply truncation after the retrieval process to fit the context length; however, they heavily depend on manually well-crafted queries, which are impractical to create for each document set for MDS.Additionally, these methods retrieve information at a coarse granularity, leading to the inclusion of irrelevant content.To address these issues, we propose a novel retrieval-based framework that integrates query selection and document ranking and shortening into a unified process.Our approach identifies the most salient elementary discourse units (EDUs) from input documents and utilizes them as latent queries.These queries guide the document ranking by calculating relevance scores.Instead of traditional truncation, our approach filters out irrelevant EDUs to fit the context length, ensuring that only critical information is preserved for summarization.We evaluate our framework on multiple MDS datasets, demonstrating consistent improvements in ROUGE metrics while confirming its scalability and flexibility across diverse model architectures.Additionally, we validate its effectiveness through an in-depth analysis, emphasizing its ability to dynamically select appropriate queries and accurately rank documents based on their relevance scores.These results demonstrate that our framework effectively addresses context-length constraints, establishing it as a robust and reliable solution for MDS. 1 * Both authors contributed equally to this research.

Dynamic graph clustering aims to detect and track time-varying clusters in dynamic graphs, revealing the evolutionary mechanisms of complex real-world dynamic systems. Matrix factorization-based methods are promising approaches for this task; however, these methods often struggle with scalability and can be time-consuming when applied to large-scale dynamic graphs. Moreover, they tend to lack robustness and are vulnerable to real-world noisy data. To address these issues, we make three key contributions. First, to improve scalability, we propose temporal separated matrix factorization, where a single matrix is divided into multiple smaller matrices for independent factorization, resulting in faster computation. Second, to improve robustness, we introduce bi-clustering regularization, which jointly optimizes graph embedding and clustering, thereby filtering out noisy features from the graph embeddings. Third, to further enhance effectiveness and efficiency, we propose selective embedding updating, where we update only the embeddings of dynamic nodes while the embeddings of static nodes are fixed among different timestamps. Experimental results on six synthetic and five real-world benchmarks demonstrate the scalability, robustness and effectiveness of our proposed method. Source code is available at https://github.com/Clearloveyuan/DyG-MF.

Numerous effective methods have been developed to improve query-focused summarization (QFS) performance, e.g., pre-trained model-based and query-answer relevance-based methods. However, these methods still suffer from missing or redundant information due to the inability to capture and effectively utilize the interrelationship between the query and the source document, as well as between the source document and its generated summary, resulting in the summary being unable to answer the query or containing additional unrequired information. To mitigate this problem, we propose an end-to-end hierarchical two-stage summarization model, that first predicts essential content, and then generates a summary by emphasizing the predicted important sentences while maintaining separate encodings for the query and the source, so that it can comprehend not only the query itself but also the essential information in the source. We evaluated the proposed model on two QFS datasets, and the results indicated its overall effectiveness and that of each component.

With the booming development of social media, temporal link prediction (TLP), as a core technology, has been receiving increasing attention. However, current methods are based on graph neural networks, which suffer from the over-smoothing issue and easily yield indistinguishable node representations, degrading the prediction accuracy. Besides, they lack the ability to eliminate noisy temporal information and ignore the importance of high-order neighbor information for measuring the link probability between nodes. To solve these issues, we design a cross-view graph contrastive learning (GCL) framework for TLP, called Tacl. We first design two augmented views for GCL by enhancing the temporal and topological information to obtain distinguishable node representations. Then, we learn the evolution rule of temporal networks to help constrain consistency of node representations and eliminate noise. Finally, we incorporate the high-order neighbor information to measure the link probability between nodes. Extensive experiments demonstrate the effectiveness and robustness of Tacl.

Multi-modal personality traits recognition aims to recognize personality traits precisely by utilizing different modality information, which has received increasing attention for its potential applications in human-computer interaction. Current methods almost fail to extract distinguishable features, remove noise, and align features from different modalities, which dramatically affects the accuracy of personality traits recognition. To deal with these issues, we propose an emotion-guided multi-modal fusion and contrastive learning framework for personality traits recognition. Specifically, we first use supervised contrastive learning to extract deeper and more distinguishable features from different modalities. After that, considering the close correlation between emotions and personalities, we use an emotion-guided multi-modal fusion mechanism to guide the feature fusion, which eliminates the noise and aligns the features from different modalities. Finally, we use an auto-fusion structure to enhance the interaction between different modalities to further extract essential features for final personality traits recognition. Extensive experiments on two benchmark datasets indicate that our method achieves state-of-the-art performance and robustness.

Dynamic community detection (or graph clustering) in temporal networks has attracted much attention because it is promising for revealing the underlying mechanism of complex real-world systems. Current methods are criticized for the independence of graph representation learning and graph clustering, considerable noise during temporal information smoothing, and high time complexity. We propose a R obust T emporal S moothing C lustering method (RTSC), which involves joint graph representation learning and graph clustering, to solve these problems. RTSC can be formulated as a constrained multi-objective optimization problem. Specifically, three-order successive snapshots are first projected into the same subspace via graph embedding. We then use the embedding matrices to learn a common low-rank block-diagonal matrix that contains current clustering information and specific noise matrices with a sparse constraint to remove noise at each time step. To efficiently solve the challenging optimization problem, we also propose an optimization procedure based on the augmented Lagrangian multiplier (ALM) scheme. Experimental results on six artificial datasets and four real-world dynamic network datasets indicate that RTSC performs better than six state-of-the-art algorithms for dynamic clustering in temporal networks.

Social media has become a platform where users post their messages about a wide range of topics, making it a useful source of information to summarize events such as sports matches. Previous summaries of sports matches generated using social media tended to be biased towards one of the teams, due to a high proportion of the posts used being from fans of the teams involved. This is problematic because in general people desire summaries that are free from bias and objective. To remedy this problem and generate higher quality summaries, we propose two approaches. The first is a function maximization method which measures the objectivity of each post based on its constituent words. The second is a neural network-based approach, where we use an encoder-decoder architecture. Then, we compare them with an existing approach and show promising results that indicate the effectiveness of our methods.

Small images of emojis have unique characteristics as additional information in understanding writers’ intentions. They enable social media users to emphasize their emotions and to express gestural movements in their posts. In addition to emojis, kaomojis (emoticons or facemarks) also behave in a similar way. They are composed of a sequence of characters, which are popularized especially in Asian countries. Although both emojis and kaomojis fulfill similar functions and share the same meaning that can be clues in opinion mining or sentiment analysis, the previous researches have been biased to explore emojis and kaomojis separately. In this paper, we align emojis and kaomojis together as a single token in the Japanese context to offer a bridge between them. Specifically, we aim to judge whether emojis and kaomojis share the same meaning or are similar with each other. We assume that emojis and kaomojis are both a single word in order to obtain their linguistic information with the skip-gram model. Furthermore, we present a new approach to consider the appearances of emojis and kaomojis in themselves, meaning that we explore the information of their visually similar shapes. We regard both of them as a single image to take into account their visual information with the CNN model. We merge two different perspectives toward emojis and kaomojis by exploring their linguistic and visual information simultaneously on the same space. The experimental results showed that we can align an unlimited number of emojis and kaomojis together with their representations (embeddings), and adding the visual information to the linguistic information can improve their representations.

We present an automated, real-time tweet selection system for TV news programs. The system collects tweets related to a TV news program and chooses an appropriate tweet every 10 seconds for display. The selection procedure consists of two steps: assessing the importance of each tweet, and assessing the difference between the tweet and previously selected tweets. The previously selected tweets are taken into consideration for the purpose of maintaining the diversity of the entire set of selected tweets. We conducted experiments with a real TV news program and showed that the system developed in this study can select appropriate tweets.

The personality that is estimated based on documents of blogs or tweets in Twitter can not agree in the sender’s real personality. It is important that we recognize the difference between these estimated and real personalities. This paper constructs a knowledge-base for extracting the sender’s virtual personality in customer-generated media. We focus on sender’s emotions that are included in sender’s posts for automatic personality estimation. We examined the correlation between the ratio of each emotion term (anger, sadness, fear, disappointment, regret, guilt, shame, pleasure, and ease) in all sentences of each participant and the values of NEO-FFI (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience) based on the experiment that human subjects who stayed in each sender’s character answered to NEO-FFI.As an evaluation result, we find out that the sender’s virtual personality is potentially-correlated with emotions in sender’s posts.

Twitter has emerged as a platform for crowds to express their opinions. Many Twitter users post their opinions, impressions, and statuses of televised events such as sports events. However, since the volume of such posts is extremely huge, it requires a lot of time and effort to understand what happens within events. We propose a method of generating live sports updates from Twitter posts on an event. Our method selects descriptive and prompt tweets that are posted within a short time after important sub events by exploiting users called good reporters, who promptly explain what is happening at each moment throughout the event. The experimental results indicated that our new technique generated more comprehensive updates than other methods presented in previous work.

We propose a new model for the guided text summarization task. In this task, it is required that a generated summary covers all the aspects, which are predefined for the topic of the given document cluster; for example, aspects for the topic "Accidents and Natural Disasters" include WHAT, WHEN, WHERE, WHY, WHO AFFECTED, DAMAGES and COUNTERMEASURES. We use as a scorer for an aspect, the maximum entropy classifier that predicts whether each sentence reflects the aspect or not. We formalize the coverage of the aspects as a max-min problem, which enables a summary to cover aspects in a well-balanced manner. In the max-min problem, the minimum of the aspect scores is going to be maximized so that the summary contains all the aspects as much as possible. Furthermore, we integrate the model based on the max-min problem with the maximum coverage summarization model, which generates a summary containing as many conceptual units as possible. Through the experiments on benchmark datasets for the guided summarization, we show that our model outperforms other approaches in terms of ROUGE-2.

We propose to use a structured output learning for summary generation based on the maximum coverage problem. Our method learns a function that outputs the benefit of each conceptual unit in the document cluster for this summarization model. In the training, we iteratively run a greedy algorithm that accepts items (sentences) with different costs (length) in order to generate a summary within the given maximum length limit. We empirically show that the structured output learning works well for this task and also examine its behavior in several dierent settings.

We propose a multi-document generic summarization model based on the budgeted median problem. Our model selects sentences to generate a summary so that every sentence in the document cluster can be assigned to and be represented by a sentence in the summary as much as possible. The advantage of this model is that it covers the entire relevant part of the document cluster through sentence assignment and can incorporate asymmetric relations between sentences such as textual entailment.

Among a huge number of blogs on the internet, only some of them are considered to have great contents and worth to be explored. We call such kind of blogs cool blogs and attempt to identify them. To solve the cool blog identification problem, we consider three assumptions on cool blogs: (1) cool blogs tend to have definite topics, (2) cool blogs tend to have sufficient amount of blog entries, and (3) cool blogs tend to have certain levels of topic consistency among their blog entries. Corresponding to these assumptions, we extract a mixture of topic probabilities using a topic model, exploit the number of blog entries of each blog, and calculate the topic consistency among blog entries using distance functions over topic probabilities, respectively. We show the benefits of the proposed assumptions through these features. A feature unification model is also presented to achieve highest effectiveness. The experimental results on Japanese blog data show that we can improve the classification results by applying proposed assumptions.

We present a system to automatically generate RSS feeds from HTML documents that consist of time-series items with date expressions, e.g., archives of weblogs, BBSs, chats, mailing lists, site update descriptions, and event announcements. Our system extracts date expressions, performs structure analysis of a HTML document, and detects or generates titles from the document.

We present a system to automatically generate RSS feeds from HTML documents that consist of time-series items with date expressions, e.g., archives of weblogs, BBSs, chats, mailing lists, site update descriptions, and event announcements. Our system extracts date expressions, performs structure analysis of a HTML document, and detects or generates titles from the document.