OpenRaiser/Intern-Atlas huggingface dataset:
Time Interval Aware Self-Attention for Sequential Recommendation
Authors: Jiacheng Li, Yujie Wang, Julian J. McAuley
Venue: WSDM
Year: 2020

Sequential recommender systems seek to exploit the order of users' interactions, in order to predict their next action based on the context of what they have done recently. Traditionally, Markov Chains(MCs), and more recently Recurrent Neural Networks (RNNs) and Self Attention (SA) have proliferated due to their ability to capture the dynamics of sequential patterns. However a simplifying assumption made by most of these models is to regard interaction histories as ordered sequences, without regard for the time intervals between each interaction (i.e., they model the time-order but not the actual timestamp). In this paper, we seek to explicitly model the timestamps of interactions within a sequential modeling framework to explore the influence of different time intervals on next item prediction. We propose TiSASRec (Time Interval aware Self-attention based sequential recommendation), which models both the absolute positions of items as well as the time intervals between them in a sequence. Extensive empirical studies show the features of TiSASRec under different settings and compare the performance of self-attention with different positional encodings. Furthermore, experimental results show that our method outperforms various state-of-the-art sequential models on both sparse and dense datasets and different evaluation metrics.
Learning with Small Data
Authors: Zhenhui Li, Huaxiu Yao, Fenglong Ma
Venue: WSDM
Year: 2020

In the era of big data, it is easy for us collect a huge number of image and text data. However, we frequently face the real-world problems with only small (labeled) data in some domains, such as healthcare and urban computing. The challenge is how to make machine learn algorithms still work well with small data? To solve this challenge, in this tutorial, we will cover the state-of-the-art machine learning techniques to handle small data issue. In particular, we focus on the following three aspects: (1) Providing a comprehensive review of recent advances in exploring the power of knowledge transfer, especially focusing on meta-learning; (2) introducing the cutting-edge techniques of incorporating human/expert knowledge into machine learning models; and (3) identifying the open challenges to data augmentation techniques, such as generative adversarial networks. We believe this is an emerging and potentially high-impact topic in computational data science, which will attract both researchers and practitioners from academia and industry.
Initialization for Network Embedding: A Graph Partition Approach
Authors: Wenqing Lin, Feng He, Faqiang Zhang, Xu Cheng, Hongyun Cai
Venue: WSDM
Year: 2020

Network embedding has been intensively studied in the literature and widely used in various applications, such as link prediction and node classification. While previous work focus on the design of new algorithms or are tailored for various problem settings, the discussion of initialization strategies in the learning process is often missed. In this work, we address this important issue of initialization for network embedding that could dramatically improve the performance of the algorithms on both effectiveness and efficiency. Specifically, we first exploit the graph partition technique that divides the graph into several disjoint subsets, and then construct an abstract graph based on the partitions. We obtain the initialization of the embedding for each node in the graph by computing the network embedding on the abstract graph, which is much smaller than the input graph, and then propagating the embedding among the nodes in the input graph. With extensive experiments on various datasets, we demonstrate that our initialization technique significantly improves the performance of the state-of-the-art algorithms on the evaluations of link prediction and node classification by up to 7.76% and 8.74% respectively. Besides, we show that the technique of initialization reduces the running time of the state-of-the-arts by at least 20%.
Balanced Influence Maximization in Attributed Social Network Based on Sampling
Authors: Mingkai Lin, Wenzhong Li, Sanglu Lu
Venue: WSDM
Year: 2020

Influence maximization in social networks is the problem of finding a set of seed nodes in the network that maximizes the spread of influence under certain information prorogation model, which has become an important topic in social network analysis. In this paper, we show that conventional influence maximization algorithms cause uneven spread of influence among different attribute groups in social networks, which could lead to severer bias in public opinion dissemination and viral marketing. We formulate the balanced influence maximization problem to address the trade-off between influence maximization and attribute balance, and propose a sampling based solution to solve the problem efficiently. To avoid full network exploration, we first propose an attribute-based (AB) sampling method to sample attributed social networks with respect to preserving network structural properties and attribute proportion among user groups. Then we propose an attributed-based reverse influence sampling (AB-RIS) algorithm to select seed nodes from the sampled graph. The proposed AB-RIS algorithm runs efficiently with guaranteed accuracy, and achieves the trade-off between influence maximization and attribute balance. Extensive experiments based on four real-world social network datasets show that AB-RIS significantly outperforms the state-of-the-art approaches in balanced influence maximization.
Athena: A Ranking Enabled Scholarly Search System
Authors: Junfeng Liu, Shuai Ma, Renjun Hu, Chunming Hu, Jinpeng Huai
Venue: WSDM
Year: 2020

Scholarly search systems greatly aid the deep understanding of scholarly data and facilitate the research activities of scholars for scientific studies. Though a number of such systems have been developed, most of them either support rankings of limited search of entities or provide only basic ranking metrics. These existing systems also mainly adopt RDBMSs as their storage such that the linked feature of scholarly data is not fully exploited. In this study, we design and develop a novel scholarly search system Athena. (1) It supports four types of scholarly entity searches: articles, authors, venues and affiliations, and is equipped with five ranking metrics, including three traditional metrics and two comprehensive importance ranking metrics. (2) It also provides profiling of scholarly entities. (3) It further utilizes a graph storage to directly leverage the linked feature for speeding up the processing of complex queries. We demonstrate the advantages of Athena at scholarly search, profiling, graph storage and ranking quality.
Jointly Optimized Neural Coreference Resolution with Mutual Attention
Authors: Jie Ma, Jun Liu, Yufei Li, Xin Hu, Yudai Pan, Shen Sun, Qika Lin
Venue: WSDM
Year: 2020

Coreference resolution aims at recognizing different forms in a document which refer to the same entity in the real world. Although many models have been proposed and achieved success, there still exist some challenges. Recent models that use recurrent neural networks to obtain mention representations ignore dependencies between spans and their proceeding distant spans, which will lead to predicted clusters that are locally consistent but globally inconsistent. In addition, these models are trained only by maximizing the marginal likelihood of gold antecedent spans from coreference clusters, which will make some gold mentions undetectable and cause unsatisfactory coreference results. To address these challenges, we propose a neural coreference resolution model. It employs mutual attention to take into account the dependencies between spans and their proceeding spans directly (use attention mechanism to capture global information between spans and their proceeding spans). And our model is trained by jointly optimizing mention clustering and imbalanced mention detection, which enables it to detect more gold mentions in a document to make more accurate coreference decisions. Experimental results on the CoNLL-2012 English dataset show that our model can detect the most gold mentions and achieve the state-of-the-art coreference performance compared with baselines.
Beyond Statistical Relations: Integrating Knowledge Relations into Style Correlations for Multi-Label Music Style Classification
Authors: Qianwen Ma, Chunyuan Yuan, Wei Zhou, Jizhong Han, Songlin Hu
Venue: WSDM
Year: 2020

Automatically labeling multiple styles for every song is a comprehensive application in all kinds of music websites. Recently, some researches explore review-driven multi-label music style classification and exploit style correlations for this task. However, their methods focus on mining the statistical relations between different music styles and only consider shallow style relations. Moreover, these statistical relations suffer from the underfitting problem because some music styles have little training data. To tackle these problems, we propose a novel knowledge relations integrated framework (KRF) to capture the complete style correlations, which jointly exploits the inherent relations between music styles according to external knowledge and their statistical relations. Based on the two types of relations, we use graph convolutional network to learn the deep correlations between styles automatically. Experimental results show that our framework significantly outperforms the state-of-the-art methods. Further studies demonstrate that our framework can effectively alleviate the underfitting problem and learn meaningful style correlations.
Overlapping Community Detection in Static and Dynamic Networks
Authors: Renny Márquez
Venue: WSDM
Year: 2020

Studying behavior of systems through networks is important because it allows to understand them and make decisions based on this knowledge. Community detection is one of the tools used in this sense, for detection of groups in graphs. This can be done not only considering connections between nodes, but also including their attributes. Also, objects can be part of different groups with varying degrees, so overlapping fuzzy assignment is relevant in this context. Furthermore, most networks change overtime, so including this aspect also enhance the benefits of using community detection. Hence, in this doctoral thesis we propose to design models for overlapping community detection for static and dynamic networks with node attributes. Firstly, an approach based on a nonnegative matrix factorization generative model that automatically detects the number of communities in the network, is designed. Secondly, tensor factorization is used in order to overcome some of the challenges faced in the first model.
Predicting Human Mobility via Attentive Convolutional Network
Authors: Congcong Miao, Ziyan Luo, Fengzhu Zeng, Jilong Wang
Venue: WSDM
Year: 2020

Predicting human mobility is an important trajectory mining task for various applications, ranging from smart city planning to personalized recommendation system. While most of previous works adopt GPS tracking data to model human mobility, the recent fast-growing geo-tagged social media (GTSM) data brings new opportunities to this task. However, predicting human mobility on GTSM data is not trivial because of three challenges: 1) extreme data sparsity; 2) high order sequential patterns of human mobility and 3) evolving preference of users for tagging. In this paper, we propose ACN, an attentive convolutional network model for predicting human mobility from sparse and complex GTSM data. In ACN, we firstly design a multi-dimension embedding layer which jointly embeds key features (i.e., spatial, temporal and user features) that govern human mobility. Then, we regard the embedded trajectory as an "image" and learn short-term sequential patterns as local features of the image using convolution filters. Instead of directly using convention filters, we design hybrid dilated and separable convolution filters to effectively capture high order sequential patterns from lengthy trajectory. In addition, we propose an attention mechanism which learns the user long-term preference to augment convolutional network for mobility prediction. We conduct extensive experiments on three publicly available GTSM datasets to evaluate the effectiveness of our model. The results demonstrate that ACN consistently outperforms existing state-of-art mobility prediction approaches on a variety of common evaluation metrics.
SPread: Automated Financial Metric Extraction and Spreading Tool from Earnings Reports
Authors: Armineh Nourbakhsh, Mohammad M. Ghassemi, Steven Pomerville
Venue: WSDM
Year: 2020

In this paper, we present SPread, an automated financial metric extraction and spreading tool from earnings reports. The tool is created in a document-agnostic fashion, and uses an interpolation of tagging methods to capture arbitrarily complicated expressions. SPread can handle single-line items as well as metrics broken down into sub-items. A validation layer further improves the performance of upstream modules and enables the tool to reach an F1 performance of more than 87% for metrics expressed in tabular format, and 76% for metrics in free-form text. The results are displayed to end-users in an interactive web interface, which allows them to locate, compare, validate, adjust, and export the values.
Integrity 2020: Integrity in Social Networks and Media
Authors: Lluis Garcia Pueyo, Anand Bhaskar, Panayiotis Tsaparas, Aristides Gionis, Tina Eliassi-Rad, Maria Daltayanni, Yu Sun, Panagiotis Papadimitriou
Venue: WSDM
Year: 2020

The first Workshop on Integrity in Social Networks and Media is held in conjunction with the 13th ACM Conference on Web Search and Data Mining (WSDM) in Houston, Texas, USA. The goal of the workshop is to bring together researchers and practitioners to discuss content and interaction integrity challenges in social networks and social media platforms.
Stepwise Reasoning for Multi-Relation Question Answering over Knowledge Graph with Weak Supervision
Authors: Yunqi Qiu, Yuanzhuo Wang, Xiaolong Jin, Kun Zhang
Venue: WSDM
Year: 2020

Knowledge Graph Question Answering aims to automatically answer natural language questions via well-structured relation information between entities stored in knowledge graphs. When faced with a multi-relation question, existing embedding-based approaches take the whole topic-entity-centric subgraph into account, resulting in high time complexity. Meanwhile, due to the high cost for data annotations, it is impractical to exactly show how to answer a complex question step by step, and only the final answer is labeled, as weak supervision. To address these challenges, this paper proposes a neural method based on reinforcement learning, namely Stepwise Reasoning Network, which formulates multi-relation question answering as a sequential decision problem. The proposed model performs effective path search over the knowledge graph to obtain the answer, and leverages beam search to reduce the number of candidates significantly. Meanwhile, based on the attention mechanism and neural networks, the policy network can enhance the unique impact of different parts of a given question over triple selection. Moreover, to alleviate the delayed and sparse reward problem caused by weak supervision, we propose a potential-based reward shaping strategy, which can accelerate the convergence of the training algorithm and help the model perform better. Extensive experiments conducted over three benchmark datasets well demonstrate the effectiveness of the proposed model, which outperforms the state-of-the-art approaches.
NLP4REC: The WSDM 2020 Workshop on Natural Language Processing for Recommendations
Authors: Pengjie Ren, Zhaochun Ren, Fei Sun, Xiangnan He, Dawei Yin, Maarten de Rijke
Venue: WSDM
Year: 2020

Natural language processing is becoming more and more important in recommender systems. This half day workshop explores challenges and potential research directions in Recommender Systems (RSs) combining Natural Language Processing (NLP). The focus will be on stimulating discussions around how to combine natural language processing technologies with recommendation. We welcome theoretical, experimental, and methodological studies that leverage NLP technologies to advance recommender systems, as well as emphasize the applicability in practical applications. The workshop aims to bring together a diverse set of researchers and practitioners interested in investigating the interaction between NLP and RSs to develop more intelligent RSs.
A Structural Graph Representation Learning Framework
Authors: Ryan A. Rossi, Nesreen K. Ahmed, Eunyee Koh, Sungchul Kim, Anup Rao, Yasin Abbasi-Yadkori
Venue: WSDM
Year: 2020

The success of many graph-based machine learning tasks highly depends on an appropriate representation learned from the graph data. Most work has focused on learning node embeddings that preserve proximity as opposed to structural role-based embeddings that preserve the structural similarity among nodes. These methods fail to capture higher-order structural dependencies and connectivity patterns that are crucial for structural role-based applications such as visitor stitching from web logs. In this work, we formulate higher-order network representation learning and describe a general framework called HONE for learning such structural node embeddings from networks via the subgraph patterns (network motifs, graphlet orbits/positions) in a nodes neighborhood. A general diffusion mechanism is introduced in HONE along with a space-efficient approach that avoids explicit construction of the k-step motif-based matrices using a k-step linear operator. Furthermore, HONE is shown to be fast and efficient with a worst-case time complexity that is nearly-linear in the number of edges. The experiments demonstrate the effectiveness of HONE for a number of important tasks including link prediction and visitor stitching from large web log data.
Toward Activity Discovery in the Personal Web
Authors: Tara Safavi, Adam Fourney, Robert Sim, Marcin Juraszek, Shane Williams, Ned Friend, Danai Koutra, Paul N. Bennett
Venue: WSDM
Year: 2020

Individuals' personal information collections (their emails, files, appointments, web searches, contacts, etc) offer a wealth of insights into the organization and structure of their everyday lives. In this paper we address the task of learning representations of personal information items to capture individuals' ongoing activities, such as projects and tasks: Such representations can be used in activity-centric applications like personal assistants, email clients, and productivity tools to help people better manage their data and time. We propose a graph-based approach that leverages the inherent interconnected structure of personal information collections, and derive efficient, exact techniques to incrementally update representations as new data arrive. We demonstrate the strengths of our graph-based representations against competitive baselines in a novel intrinsic rating task and an extrinsic recommendation task.
DySAT: Deep Neural Representation Learning on Dynamic Graphs via Self-Attention Networks
Authors: Aravind Sankar, Yanhong Wu, Liang Gou, Wei Zhang, Hao Yang
Venue: WSDM
Year: 2020

Learning node representations in graphs is important for many applications such as link prediction, node classification, and community detection. Existing graph representation learning methods primarily target static graphs while many real-world graphs evolve over time. Complex time-varying graph structures make it challenging to learn informative node representations over time. We present Dynamic Self-Attention Network (DySAT), a novel neural architecture that learns node representations to capture dynamic graph structural evolution. Specifically, DySAT computes node representations through joint self-attention along the two dimensions of structural neighborhood and temporal dynamics. Compared with state-of-the-art recurrent methods modeling graph evolution, dynamic self-attention is efficient, while achieving consistently superior performance. We conduct link prediction experiments on two graph types: communication networks and bipartite rating networks. Experimental results demonstrate significant performance gains for DySAT over several state-of-the-art graph embedding baselines, in both single and multi-step link prediction tasks. Furthermore, our ablation study validates the effectiveness of jointly modeling structural and temporal self-attention.
Text Recognition Using Anonymous CAPTCHA Answers
Authors: Alexander Shishkin, Anastasia A. Bezzubtseva, Valentina Fedorova, Alexey Drutsa, Gleb Gusev
Venue: WSDM
Year: 2020

Internet companies use crowdsourcing to collect large amounts of data needed for creating products based on machine learning techniques. A significant source of such labels for OCR data sets is (re)CAPTCHA, which distinguishes humans from automated bots by asking them to recognize text and, at the same time, receives new labeled data in this way. An important component of such approach to data collection is the reduction of noisy labels produced by bots and non-qualified users. In this paper, we address the problem of labeling text images via CAPTCHA, where user identification is generally impossible. We propose a new algorithm to aggregate multiple guesses collected through CAPTCHA. We employ incremental relabeling to minimize the number of guesses needed for obtaining the recognized text of a good accuracy. The aggregation model and the stopping rule for our incremental relabeling are based on novel machine learning techniques and use meta features of CAPTCHA tasks and accumulated guesses. Our experiments show that our approach can provide a large amount of accurately recognized texts using a minimal number of user guesses. Finally, we report the great improvements of an optical character recognition model after implementing our approach in Yandex.
Ad Close Mitigation for Improved User Experience in Native Advertisements
Authors: Natalia Silberstein, Oren Somekh, Yair Koren, Michal Aharon, Dror Porat, Avi Shahar, Tingyi Wu
Venue: WSDM
Year: 2020

Verizon Media native advertising (also known as Yahoo Gemini native) serves billions of ad impressions daily, reaching several hundreds of millions USD in revenue yearly. Although we strive to provide the best experience for our users, there will always be some users that dislike our ads in certain cases. To address these situations Gemini native platform provides an ad close mechanism that enables users to close ads that they dislike and also to provide a reasoning for their action. Surprisingly, users do care about their ad experience and their engagement with the ad close mechanism is quite significant. While the ad close rate (ACR) is lower than the click through rate (CTR), they are of the same order of magnitude, especially on Yahoo mail properties. Since ad close events indicate bad user experience caused mostly by poor ad quality, we would like to exploit the ad close signals to improve user experience and reduce the number of ad close events while maintaining a predefined total revenue loss. In this work we present our ad close mitigation (ACM) solution that penalizes ads with high closing likelihood, in our auctions. In particular, we use the ad close signal and other available features to predict the probability of an ad close event, and calculate the expected loss due to such event for using the true expected revenue in the auction. We show that this approach fundamentally changes the generalized second price (GSP) auction and provides incentive for advertisers to improve their ads' quality. Our solution was tested in both offline and large scale online settings, serving real Gemini native traffic. Results of the online experiment show that we are able to reduce the number of ad close events by more than 20%, while decreasing the revenue in less than 0.4%. In addition, we present a large scale analysis of the ad close signal that supports various design decisions and sheds light on ways the ad close mechanism affects different crowds.