KGAT: Knowledge Graph Attention Network for Recommendation

To provide more accurate, diverse, and explainable recommendation, it is compulsory to go beyond modeling user-item interactions and take side information into account. Traditional methods like factorization machine (FM) cast it as a supervised learning problem, which assumes each interaction as an independent instance with side information encoded. Due to the overlook of the relations among instances or items (e.g., the director of a movie is also an actor of another movie), these methods are insufficient to distill the collaborative signal from the collective behaviors of users. In this work, we investigate the utility of knowledge graph (KG), which breaks down the independent interaction assumption by linking items with their attributes. We argue that in such a hybrid structure of KG and user-item graph, high-order relations --- which connect two items with one or multiple linked attributes --- are an essential factor for successful recommendation. We propose a new method named Knowledge Graph Attention Network (KGAT) which explicitly models the high-order connectivities in KG in an end-to-end fashion. It recursively propagates the embeddings from a node's neighbors (which can be users, items, or attributes) to refine the node's embedding, and employs an attention mechanism to discriminate the importance of the neighbors. Our KGAT is conceptually advantageous to existing KG-based recommendation methods, which either exploit high-order relations by extracting paths or implicitly modeling them with regularization. Empirical results on three public benchmarks show that KGAT significantly outperforms state-of-the-art methods like Neural FM and RippleNet. Further studies verify the efficacy of embedding propagation for high-order relation modeling and the interpretability benefits brought by the attention mechanism.Comment: KDD 2019 research trac

Explainable Reasoning over Knowledge Graphs for Recommendation

Incorporating knowledge graph into recommender systems has attracted increasing attention in recent years. By exploring the interlinks within a knowledge graph, the connectivity between users and items can be discovered as paths, which provide rich and complementary information to user-item interactions. Such connectivity not only reveals the semantics of entities and relations, but also helps to comprehend a user's interest. However, existing efforts have not fully explored this connectivity to infer user preferences, especially in terms of modeling the sequential dependencies within and holistic semantics of a path. In this paper, we contribute a new model named Knowledge-aware Path Recurrent Network (KPRN) to exploit knowledge graph for recommendation. KPRN can generate path representations by composing the semantics of both entities and relations. By leveraging the sequential dependencies within a path, we allow effective reasoning on paths to infer the underlying rationale of a user-item interaction. Furthermore, we design a new weighted pooling operation to discriminate the strengths of different paths in connecting a user with an item, endowing our model with a certain level of explainability. We conduct extensive experiments on two datasets about movie and music, demonstrating significant improvements over state-of-the-art solutions Collaborative Knowledge Base Embedding and Neural Factorization Machine.Comment: 8 pages, 5 figures, AAAI-201

Generalized Second Price Auction with Probabilistic Broad Match

Generalized Second Price (GSP) auctions are widely used by search engines today to sell their ad slots. Most search engines have supported broad match between queries and bid keywords when executing GSP auctions, however, it has been revealed that GSP auction with the standard broad-match mechanism they are currently using (denoted as SBM-GSP) has several theoretical drawbacks (e.g., its theoretical properties are known only for the single-slot case and full-information setting, and even in this simple setting, the corresponding worst-case social welfare can be rather bad). To address this issue, we propose a novel broad-match mechanism, which we call the Probabilistic Broad-Match (PBM) mechanism. Different from SBM that puts together the ads bidding on all the keywords matched to a given query for the GSP auction, the GSP with PBM (denoted as PBM-GSP) randomly samples a keyword according to a predefined probability distribution and only runs the GSP auction for the ads bidding on this sampled keyword. We perform a comprehensive study on the theoretical properties of the PBM-GSP. Specifically, we study its social welfare in the worst equilibrium, in both full-information and Bayesian settings. The results show that PBM-GSP can generate larger welfare than SBM-GSP under mild conditions. Furthermore, we also study the revenue guarantee for PBM-GSP in Bayesian setting. To the best of our knowledge, this is the first work on broad-match mechanisms for GSP that goes beyond the single-slot case and the full-information setting

Privacy protection for e-health systems by means of dynamic authentication and three-factor key agreement

During the past decade, the electronic healthcare (e-health) system has been evolved into a more patient-oriented service with smaller and smarter wireless devices. However, these convenient smart devices have limited computing capacity and memory size, which makes it harder to protect the user’s massive private data in the e-health system. Although some works have established a secure session key between the user and the medical server, the weaknesses still exist in preserving the anonymity with low energy consumption. Moreover, the misuse of biometric information in key agreement process may lead to privacy disclosure, which is irreparable. In this study, we design a dynamic privacy protection mechanism offering the biometric authentication at the server side whereas the exact value of the biometric template remains unknown to the server. And the user anonymity can be fully preserved during the authentication and key negotiation process because the messages transmitted with the proposed scheme are untraceable. Furthermore, the proposed scheme is proved to be semantic secure under the Real-or-Random Model. The performance analysis shows that the proposed scheme suits the e-health environment at the aspect of security and resource occupation

Research on the social integration of the second generation of international Chinese immigrants: Example of children of Chinese immigrants from mainland China aged 17-35 in Lisbon, Portugal

Portugal has a long history of receiving immigrants, because of the aging of the population, the country's economic activities and pension issues become more and more serious, the role of foreign immigrants in the life of Portuguese society has become increasingly important. Logically that the second generation of immigrants will gradually grow to become an important force in building Portuguese society. However, due to various reasons, such as ethnicity, economic conditions, and social climate, the social status and development of the second generation of immigrants may not be in line with that of the native youth, and there are concerns about the degree of social integration and trends in their social status. This study focuses on the second generation of Chinese immigrants aged 17 to 35 years’ old who are of mainland Chinese origin and currently living in Lisbon, Portugal, with residence status. I will try to explore the identity of the second generation of Chinese immigrants in a multicultural environment by combining the theories of comprehensive cultural identity and social integration with the characteristics of the local Chinese society and integrate data from three aspects: family environment, schooling, and community. The results show that the second generation of immigrants has a strong sense of family mission and responsibility, has a higher level of education than the previous generation, and has a positive correlation between their professional development and the level of social integration of the previous generation.Portugal tem uma longa história de acolhimento de imigrantes, devido ao envelhecimento da população, as atividades econômicas do país e as questões previdenciárias se tornam cada vez mais sérias, o papel dos imigrantes estrangeiros na vida da sociedade portuguesa tem se tornado cada vez mais importante. Logicamente que a segunda geração de imigrantes irá gradualmente crescer para se tornar uma força importante na construção da sociedade portuguesa. Entretanto, devido a várias razões, tais como etnia, condições econômicas e clima social, o status social e o desenvolvimento da segunda geração de imigrantes pode não estar de acordo com o da juventude nativa, e há preocupações sobre o grau de integração social e tendências em seu status social. Este estudo se concentra na segunda geração de imigrantes chineses de 17 a 35 anos de idade que são de origem chinesa continental e que atualmente vivem em Lisboa, Portugal, com status de residência. Vou tentar explorar a identidade da segunda geração de imigrantes chineses em um ambiente multicultural, combinando as teorias de identidade cultural abrangente e integração social com as características da sociedade chinesa local e integrar dados de três aspectos: ambiente familiar, escolaridade e comunidade. Os resultados mostram que a segunda geração de imigrantes tem um forte senso de missão e responsabilidade familiar, tem um nível de educação superior à geração anterior, e tem uma correlação positiva entre seu desenvolvimento profissional e o nível de integração social da geração anterior

Research on the social integration of the second generation of international Chinese immigrants: Example of children of Chinese immigrants from mainland China aged 17-35 in Lisbon, Portugal

Portugal has a long history of receiving immigrants, because of the aging of the population, the country's economic activities and pension issues become more and more serious, the role of foreign immigrants in the life of Portuguese society has become increasingly important. Logically that the second generation of immigrants will gradually grow to become an important force in building Portuguese society. However, due to various reasons, such as ethnicity, economic conditions, and social climate, the social status and development of the second generation of immigrants may not be in line with that of the native youth, and there are concerns about the degree of social integration and trends in their social status. This study focuses on the second generation of Chinese immigrants aged 17 to 35 years’ old who are of mainland Chinese origin and currently living in Lisbon, Portugal, with residence status. I will try to explore the identity of the second generation of Chinese immigrants in a multicultural environment by combining the theories of comprehensive cultural identity and social integration with the characteristics of the local Chinese society and integrate data from three aspects: family environment, schooling, and community. The results show that the second generation of immigrants has a strong sense of family mission and responsibility, has a higher level of education than the previous generation, and has a positive correlation between their professional development and the level of social integration of the previous generation.Portugal tem uma longa história de acolhimento de imigrantes, devido ao envelhecimento da população, as atividades econômicas do país e as questões previdenciárias se tornam cada vez mais sérias, o papel dos imigrantes estrangeiros na vida da sociedade portuguesa tem se tornado cada vez mais importante. Logicamente que a segunda geração de imigrantes irá gradualmente crescer para se tornar uma força importante na construção da sociedade portuguesa. Entretanto, devido a várias razões, tais como etnia, condições econômicas e clima social, o status social e o desenvolvimento da segunda geração de imigrantes pode não estar de acordo com o da juventude nativa, e há preocupações sobre o grau de integração social e tendências em seu status social. Este estudo se concentra na segunda geração de imigrantes chineses de 17 a 35 anos de idade que são de origem chinesa continental e que atualmente vivem em Lisboa, Portugal, com status de residência. Vou tentar explorar a identidade da segunda geração de imigrantes chineses em um ambiente multicultural, combinando as teorias de identidade cultural abrangente e integração social com as características da sociedade chinesa local e integrar dados de três aspectos: ambiente familiar, escolaridade e comunidade. Os resultados mostram que a segunda geração de imigrantes tem um forte senso de missão e responsabilidade familiar, tem um nível de educação superior à geração anterior, e tem uma correlação positiva entre seu desenvolvimento profissional e o nível de integração social da geração anterior