Multi-modal recommender systems (MMRSs) have demonstrated significant potential in mitigating data sparsity and cold start problems by leveraging diverse multi-modal data, such as text and images. To further improve the recommendation accuracy, some MMRSs have integrated knowledge graphs (KGs) to enrich the graph structure with meaningful relationships between entities, giving rise to the task of KG-based MMRSs. Despite the promising results achieved by existing studies on this task, (i) they overlook the substantial noise introduced within the auxiliary information (i.e., both KGs and multi-modal data), and (ii) most of them struggle to effectively align the knowledge from history user-item interactions and auxiliary information. To tackle these limitations, we propose a novel model entitled MAGIC (noise Mitigation and knowledge Aignment for knowledge Graph-based multI-modal reCommendation). Specifically, to tackle the limitation (i), we design a noise-aware heterogeneous aggregation layer in the KG-based modal enhancement module. To address the limitation (ii), MAGIC introduces adversarial learning in the CF-based adversarial learning module, and exploits contrastive learning in the fusion and prediction module. The experiments conducted on two extended real-world datasets from different domains demonstrate the superiority of MAGIC over state-of-the-art baselines.

Complex social event summarization is a problem which has been important for real-world applications, including crisis management, rumor control and government policy tracking. However, in many critical situations, social events are complex and context-sensitive, which demands the online summarization of social events in an integrated manner. Motivated by this, we propose an online complex social event summarization approach, namely SOMA, which summarizes the complex social events over multiple attributes including media content and contexts simultaneously. The evaluation shows that our proposed approach outperforms the existing solutions for event summarizaiton in terms of effectiveness and efficiency.

Situation-awareness (SA) has been important for natural disaster management and smart decision making. Traditionally, security officers recognize disaster situations through emergency reporting with phone calls. However, due to the busy phone lines or power outages caused by disasters, traditional SA has been limited in terms of time and mitigation response, which may cause high loss in life and properties in disaster areas. Social media-based SA has been studied recently. However, existing systems are designed for events without nonconsecutive migrations over location and time. In this demo, we design HSAP, the first human-in-the-loop social media-based SA platform for effective and efficient management of disasters with complex event migrations. HSAP is designed with a number of novel techniques, including complex social event detection, summarization, and human-in-the-loop result filtering. We demonstrate the usage of HSAP via Nepal earthquake 2015.

Complex social event summarization is a problem which has been shown having great utility for real-world applications, including crisis management, rumor control and government policy tracking. In recent years there has been significant research effort spent on effectively extracting meaningful textual descriptions of an event. However, in many critical situations, social events are complex and context-sensitive, which demands the online summarization of social events in an integrated manner. In this paper, we propose the first online complex social event summarization approach, namely SOMA, which summarizes the complex social events over multiple attributes including media content and contexts simultaneously. Specifically, we first propose a deep learning model that comprehensively summarizes events in regards to the text description and locations that they appear in, by utilizing their hidden connections in posts. We then propose a summary generator over time, text and location to achieve a maximal coverage of the summary over the original social event and minimal redundancy of the summary. Furthermore, we propose a location estimation method to address the location sparsity issue of complex events by mining the correlation between text and location. The evaluation over four real-event datasets and three benchmark datasets shows that our proposed approach outperforms the existing solutions for event summarizaiton in terms of effectiveness and efficiency.

Event popularity prediction over social media is crucial for estimating information propagation scope, decision making, and emergency prevention. It has been widely inves-tigated by existing approaches focusing on predicting single attribute occurrences which are not comprehensive enough for representing complex social event propagation. Motivated by this, we propose a novel hashtag-influence-based event popularity prediction by mining the impact of an influential hashtag set on the event propagation. We have conducted extensive experiments to prove the effectiveness and efficiency of the proposed approach.

Event popularity prediction over social media is crucial for estimating information propagation scope, decision making, and emergency prevention. However, existing approaches only focus on predicting the occurrences of single attribute such as a message, a hashtag or an image, which are not comprehensive enough for representing complex social event propagation. In this paper, we predict the event popularity, where an event is described as a set of messages containing multiple hashtags. We propose a novel hashtag-influence-based event popularity prediction by mining the impact of an influential hashtag set on the event propagation. Specifically, we first propose a hashtag-influence-based cascade model to select the influential hashtags over an event hashtag graph built by the pairwise hashtag similarity and the topic distribution of event-related hashtags. A novel measurement is proposed to identify the hashtag influence of an event over its content and social impacts. A hashtag correlation-based algorithm is proposed to optimize the seed selection in a greedy manner. Then, we propose an event-fitting boosting model to predict the event popularity by embedding the feature importance over events into the XGBOOST model. Moreover, we propose an event-structure-based method, which incrementally updates the prediction model over social streams. We have conducted extensive experiments to prove the effectiveness and efficiency of the proposed approach.