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Knowledge Vault: A Web-scale approach to probabilistic knowledge fusion
- In submission
, 2014
"... Recent years have witnessed a proliferation of large-scale knowledge bases, including Wikipedia, Freebase, YAGO, Mi-crosoft’s Satori, and Google’s Knowledge Graph. To in-crease the scale even further, we need to explore automatic methods for constructing knowledge bases. Previous ap-proaches have pr ..."
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Cited by 49 (6 self)
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Recent years have witnessed a proliferation of large-scale knowledge bases, including Wikipedia, Freebase, YAGO, Mi-crosoft’s Satori, and Google’s Knowledge Graph. To in-crease the scale even further, we need to explore automatic methods for constructing knowledge bases. Previous ap-proaches have primarily focused on text-based extraction, which can be very noisy. Here we introduce Knowledge Vault, a Web-scale probabilistic knowledge base that com-bines extractions from Web content (obtained via analysis of text, tabular data, page structure, and human annotations) with prior knowledge derived from existing knowledge repos-itories. We employ supervised machine learning methods for fusing these distinct information sources. The Knowledge Vault is substantially bigger than any previously published structured knowledge repository, and features a probabilis-tic inference system that computes calibrated probabilities of fact correctness. We report the results of multiple studies that explore the relative utility of the different information sources and extraction methods. Keywords Knowledge bases; information extraction; probabilistic mod-els; machine learning 1.
Hinge-loss Markov random fields and probabilistic soft logic
, 2015
"... A fundamental challenge in developing high-impact machine learning technologies is balancing the ability to model rich, structured domains with the ability to scale to big data. Many important problem areas are both richly structured and large scale, from social and biological networks, to knowledge ..."
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Cited by 6 (4 self)
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A fundamental challenge in developing high-impact machine learning technologies is balancing the ability to model rich, structured domains with the ability to scale to big data. Many important problem areas are both richly structured and large scale, from social and biological networks, to knowledge graphs and the Web, to images, video, and natural language. In this paper, we introduce two new formalisms for modeling structured data, distinguished from previous approaches by their ability to both capture rich structure and scale to big data. The first, hinge-loss Markov random fields (HL-MRFs), is a new kind of probabilistic graphical model that generalizes different approaches to convex inference. We unite three approaches from the randomized algorithms, probabilistic graphical models, and fuzzy logic communities, showing that all three lead to the same inference objective. We then derive HL-MRFs by generalizing this unified objective. The second new formalism, probabilistic soft logic (PSL), is a probabilistic programming language that makes HL-MRFs easy to define using a syntax based on first-order logic. We next introduce an algorithm for inferring most-probable variable assignments (MAP inference) that is much more scalable than general-purpose convex optimization software, because it uses message passing to take advantage of sparse dependency structures. We then show how to learn the parameters of HL-MRFs. The learned HL-MRFs are as accurate as analogous discrete models, but much more scalable. Together, these algorithms enable HL-MRFs and PSL to model rich, structured data at scales not previously possible.
Large-Scale Knowledge Graph Identification using PSL
"... Building a web-scale knowledge graph, which captures information about entities and the relationships between them, represents a formidable challenge. While many largescale information extraction systems operate on web corpora, the candidate facts they produce are noisy and incomplete. To remove noi ..."
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Cited by 1 (0 self)
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Building a web-scale knowledge graph, which captures information about entities and the relationships between them, represents a formidable challenge. While many largescale information extraction systems operate on web corpora, the candidate facts they produce are noisy and incomplete. To remove noise and infer missing information in the knowledge graph, we propose knowledge graph identification: a process of jointly reasoning about the structure of the knowledge graph, utilizing extraction confidences and leveraging ontological information. Scalability is often a challenge when building models in domains with rich structure, but we use probabilistic soft logic (PSL), a recentlyintroduced probabilistic modeling framework which easily scales to millions of facts. In practice, our method performs joint inference on a real-world dataset containing over 1M facts and 80K ontological constraints in 12 hours and produces a high-precision set of facts for inclusion into a knowledge graph. 1.
Joint prediction for entity/eventlevel sentiment analysis using probabilistic soft logic models
- In Proceedings of the 2014 Conference on Empirical Methods in Natural Language Processing (EMNLP
"... Abstract In this work, we build an entity/event-level sentiment analysis system, which is able to recognize and infer both explicit and implicit sentiments toward entities and events in the text. We design Probabilistic Soft Logic models that integrate explicit sentiments, inference rules, and +/-e ..."
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Abstract In this work, we build an entity/event-level sentiment analysis system, which is able to recognize and infer both explicit and implicit sentiments toward entities and events in the text. We design Probabilistic Soft Logic models that integrate explicit sentiments, inference rules, and +/-effect event information (events that positively or negatively affect entities). The experiments show that the method is able to greatly improve over baseline accuracies in recognizing entity/event-level sentiments.
Bonding Vertex Sets Over Distributed Graph: A Betweenness Aware Approach
"... ABSTRACT Given two sets of vertices in a graph, it is often of a great interest to find out how these vertices are connected, especially to identify the vertices of high prominence defined on the topological structure. In this work, we formally define a Vertex Set Bonding query (shorted as VSB), wh ..."
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ABSTRACT Given two sets of vertices in a graph, it is often of a great interest to find out how these vertices are connected, especially to identify the vertices of high prominence defined on the topological structure. In this work, we formally define a Vertex Set Bonding query (shorted as VSB), which returns a minimum set of vertices with the maximum importance w.r.t total betweenness and shortest path reachability in connecting two sets of input vertices. We find that such a kind of query is representative and could be widely applied in many real world scenarios, e.g., logistic planning, social community bonding and etc. Challenges are that many of such applications are constructed on graphs that are too large to fit in single server, and the VSB query evaluation turns to be NP-hard. To cope with the scalability issue and return the near optimal result in almost real time, we propose a generic solution framework on a shared nothing distributed environment. With the development of two novel techniques, guided graph exploration and betweenness ranking on exploration, we are able to efficiently evaluate queries for error bounded results with bounded space cost. We demonstrate the effectiveness of our solution with extensive experiments over both real and synthetic large graphs on the Google's Cloud platform. Comparing to the exploration only baseline method, our method achieves several times of speedup.
Joint Judgments with a Budget: Strategies for Reducing the Cost of Inference
"... Machine learning techniques are often subjected to test-time budgets, in scenarios that range from choosing which advertisements to show a user of a social network to detecting faces with the limited resources available in a digital camera. Solutions to this problem formulate a trade-off between the ..."
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Machine learning techniques are often subjected to test-time budgets, in scenarios that range from choosing which advertisements to show a user of a social network to detecting faces with the limited resources available in a digital camera. Solutions to this problem formulate a trade-off between the cost and quality of a model(Viola & Jones, 2001; Saberian & Vasconcelos, 2010; Xu et al., 2013) by formulating a loss function that combines a measure of error with a measure of computational cost. Minimizing this loss function on a training set drawn from the expected distribution of instances produces a model sensitive to computational cost. However, most work in this field has focused on classifiers that make predictions on independent instances, such as a single user or a single image. We consider a different setting, where judgments are made jointly over a set of instances. Structural or temporal applications can benefit from making such judgments jointly: choosing advertisements for a set of related users(Sharara et al., 2011) or recognizing actors in a sequence of images(Khamis et al., 2012) provide superior results. Performing such joint reasoning under a test-time budget requires a different approach; instead of feature computation, the key contributors to the computational cost in such models are the dependencies between predictions.
Ontology-Aware Partitioning for Knowledge Graph Identification
"... Knowledge graphs provide a powerful representation of entities and the relationships between them, but automatically constructing such graphs from noisy extractions presents numerous challenges. Knowledge graph identification (KGI) is a technique for knowledge graph construction that jointly reasons ..."
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Knowledge graphs provide a powerful representation of entities and the relationships between them, but automatically constructing such graphs from noisy extractions presents numerous challenges. Knowledge graph identification (KGI) is a technique for knowledge graph construction that jointly reasons about entities, attributes and relations in the presence of uncertain inputs and ontological constraints. Although knowledge graph identification shows promise scaling to knowledge graphs built from millions of extractions, increasingly powerful extraction engines may soon require knowledge graphs built from billions of extractions. One tool for scaling is partitioning extractions to allow reasoning to occur in parallel. We explore approaches which leverage ontological information and distributional information in partitioning. We compare these techniques with hash-based approaches, and show that using a richer partitioning model that incorporates the ontology graph and distribution of extractions provides superior results. Our results demonstrate that partitioning can result in order-of-magnitude speedups without reducing model performance.
Convex inference for community discovery in signed networks ∗
"... In contrast to traditional social networks, signed ones encode both relations of affinity and disagreement. Community discovery in this kind of networks has been successfully addressed using the Potts model, originated in statistical me-chanics to explain the magnetic dipole moments of atomic spins. ..."
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In contrast to traditional social networks, signed ones encode both relations of affinity and disagreement. Community discovery in this kind of networks has been successfully addressed using the Potts model, originated in statistical me-chanics to explain the magnetic dipole moments of atomic spins. However, due to the computational complexity of finding an exact solution, it has not been ap-plied to many real-world networks yet. We propose a novel approach to compute an approximated solution to the Potts model applied to the context of community discovering, which is based on a continuous convex relaxation of the original prob-lem using hinge-loss functions. We show empirically the benefits of the proposed method in comparison with loopy belief propagation in terms of the communities discovered. We illustrate the scalability and effectiveness of our approach by ap-plying it to the network of voters of the European Parliament that we have crawled for this study. This large-scale and dense network comprises about 300 votings pe-riods on the actual term involving a total of more than 730 voters. Remarkably, the two major communities are those created by the european-antieuropean antag-onism, rather than the classical right-left antagonism. 1
Understanding Influence in Online Professional Networks
"... Social networks have become part and parcel of our lives. With social networks, users have access to tremendous amount of information that influence many as-pects of their lives such as daily activities, habits, and decisions. Recently, there has been a growing interest in understanding influence in ..."
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Social networks have become part and parcel of our lives. With social networks, users have access to tremendous amount of information that influence many as-pects of their lives such as daily activities, habits, and decisions. Recently, there has been a growing interest in understanding influence in social networks. Previ-ous work in this area characterize influence as propagation of actions in the social network. However, typically only a single action type is considered in charac-terizing influence. In this paper, we present a holistic model to jointly represent different user actions and their respective propagations in the social network. Our model captures node features such as user seniority in the social network, and edge features such as connection strength to characterize influence. Our model is capable of representing and combining different kinds of information users as-similate in the social network and compute pairwise values of influence taking the different types of actions into account. We evaluate our models on data from LinkedIn and show the effectiveness of the inferred influence scores in predicting user actions. We further demonstrate that modeling different user actions, node and edge relationships between people leads to around 20 % increase in preci-sion at top k in predicting user actions, when compared to a model based only on General Threshold Model. 1