Semantic Networks
Approach for Semi-automatic Construction of Anti-infective Drug Ontology Based on Entity Linking
Shen, Ying, Deng, Yang, Yuan, Kaiqi, Liu, Li, Liu, Yong
The task of entity relation extraction discovers new relation facts and enables broader applications of knowledge graph. Distant supervision is widely adopted for relation extraction, which requires large amounts of texts containing entity pairs as training data. However, in some specific domains such as medicalrelated applications,entity pairs that have certain relations might not appear together, thus it is difficult to meet the requirement for distantly supervised relation extraction. In the light of this challenge, we propose a novel path-based model to discover new entity relation facts. Instead of finding texts for relation extraction, the proposed method extracts path-only information for entity pairs from the current knowledgegraph. For each pair of entities, multiple paths can be extracted, and some of them are more useful for relation extraction than others. In order to capture this observation, we employ attention mechanism to assign different weights for different paths, which highlights the useful paths for entity relation extraction. To demonstrate the effectiveness of the proposed method, we conduct various experiments on a large-scale medical knowledge graph. Compared with the state-of-the-art relation extraction methods using the structure of knowledge graph, the proposed method significantly improves the accuracy of extracted relation factsand achieves the best performance.
Embedding Uncertain Knowledge Graphs
Chen, Xuelu, Chen, Muhao, Shi, Weijia, Sun, Yizhou, Zaniolo, Carlo
Embedding models for deterministic Knowledge Graphs (KG) have been extensively studied, with the purpose of capturing latent semantic relations between entities and incorporating the structured knowledge into machine learning. However, there are many KGs that model uncertain knowledge, which typically model the inherent uncertainty of relations facts with a confidence score, and embedding such uncertain knowledge represents an unresolved challenge. The capturing of uncertain knowledge will benefit many knowledge-driven applications such as question answering and semantic search by providing more natural characterization of the knowledge. In this paper, we propose a novel uncertain KG embedding model UKGE, which aims to preserve both structural and uncertainty information of relation facts in the embedding space. Unlike previous models that characterize relation facts with binary classification techniques, UKGE learns embeddings according to the confidence scores of uncertain relation facts. To further enhance the precision of UKGE, we also introduce probabilistic soft logic to infer confidence scores for unseen relation facts during training. We propose and evaluate two variants of UKGE based on different learning objectives. Experiments are conducted on three real-world uncertain KGs via three tasks, i.e. confidence prediction, relation fact ranking, and relation fact classification. UKGE shows effectiveness in capturing uncertain knowledge by achieving promising results on these tasks, and consistently outperforms baselines on these tasks.
Words Can Shift: Dynamically Adjusting Word Representations Using Nonverbal Behaviors
Wang, Yansen, Shen, Ying, Liu, Zhun, Liang, Paul Pu, Zadeh, Amir, Morency, Louis-Philippe
Humans convey their intentions through the usage of both verbal and nonverbal behaviors during face-to-face communication. Speaker intentions often vary dynamically depending on different nonverbal contexts, such as vocal patterns and facial expressions. As a result, when modeling human language, it is essential to not only consider the literal meaning of the words but also the nonverbal contexts in which these words appear. To better model human language, we first model expressive nonverbal representations by analyzing the fine-grained visual and acoustic patterns that occur during word segments. In addition, we seek to capture the dynamic nature of nonverbal intents by shifting word representations based on the accompanying nonverbal behaviors. To this end, we propose the Recurrent Attended Variation Embedding Network (RAVEN) that models the fine-grained structure of nonverbal subword sequences and dynamically shifts word representations based on nonverbal cues. Our proposed model achieves competitive performance on two publicly available datasets for multimodal sentiment analysis and emotion recognition. We also visualize the shifted word representations in different nonverbal contexts and summarize common patterns regarding multimodal variations of word representations.
The Enterprise Knowledge Graph
Best conceived of as a "company brain," this knowledge graph focuses on integrating an organization's assortment of people, skills, experiences, materials, essential company databases, and projects, which greatly improves its self-knowledge and thereby yields competitive advantage. Compiled from combing through myriad databases, including those for human resources, emails, and manifold other sources, this knowledge graph provides the foundation for a rapid, detailed assessment of what knowledge and skills a company has at its disposal--and their relation to one another. This graph is designed to create better services and is extremely specific to an organization's industry, line of business, and area of specialization. For example, Google's and Yahoo's search engine endeavors mandate that they collect knowledge about every entity or subject in the world, so they can offer the most relevant, revealing information to their users. LinkedIn's knowledge graph, on the other hand, details people's professions, resumes, and career opportunities.1 Again, the relationships between these nodes are paramount.
Unseen Word Representation by Aligning Heterogeneous Lexical Semantic Spaces
Prokhorov, Victor, Pilehvar, Mohammad Taher, Kartsaklis, Dimitri, Lio, Pietro, Collier, Nigel
Word embedding techniques heavily rely on the abundance of training data for individual words. Given the Zipfian distribution of words in natural language texts, a large number of words do not usually appear frequently or at all in the training data. In this paper we put forward a technique that exploits the knowledge encoded in lexical resources, such as Word-Net, to induce embeddings for unseen words. Our approach adapts graph embedding and cross-lingual vector space transformation techniques in order to merge lexical knowledge encoded in ontologies with that derived from corpus statistics. We show that the approach can provide consistent performance improvements across multiple evaluation benchmarks: in-vitro, on multiple rare word similarity datasets, and invivo, in two downstream text classification tasks.
Differentiating Concepts and Instances for Knowledge Graph Embedding
Lv, Xin, Hou, Lei, Li, Juanzi, Liu, Zhiyuan
Concepts, which represent a group of different instances sharing common properties, are essential information in knowledge representation. Most conventional knowledge embedding methods encode both entities (concepts and instances) and relations as vectors in a low dimensional semantic space equally, ignoring the difference between concepts and instances. In this paper, we propose a novel knowledge graph embedding model named TransC by differentiating concepts and instances. Specifically, TransC encodes each concept in knowledge graph as a sphere and each instance as a vector in the same semantic space. We use the relative positions to model the relations between concepts and instances (i.e., instanceOf), and the relations between concepts and sub-concepts (i.e., subClassOf). We evaluate our model on both link prediction and triple classification tasks on the dataset based on YAGO. Experimental results show that TransC outperforms state-of-the-art methods, and captures the semantic transitivity for instanceOf and subClassOf relation. Our codes and datasets can be obtained from https:// github.com/davidlvxin/TransC.
Knowledge Graphs and AI in the Pharma Sector-PoolParty Semantic Suite
With the increasing speed of technological advancements, the pharmaceutical and healthcare industry needs to break up departmental data silos with Knowledge Graphs and AI to understand the value of their data. At PhUSE EU Connect 2018 we will introduce the innovative approach of PoolParty Semantic Suite to make the most out of your data with semantic data integration. Our partner Findwise, global experts in search-driven solutions for the pharmaceutical and healthcare industry, presents a series of four blog posts to help you understand how knowledge graphs and AI can leverage your data-driven innovation and improve healthcare outcome. We face grand societal challenges pinned down in the 17 UN sustainability goals and specifically number 3 Good Health and Well-being. Humans live a longer life, which shifts the population pyramid.
Knowledge Graphs and AI in the Pharma Sector (Part 2)-PoolParty Semantic Suite
In our previous post of this blog post series about knowledge graphs and AI in the pharmaceutical and healthcare industry, you got an overview of the challenges knowledge-intensive organizations face to be able to support data-driven innovation and improve healthcare outcome. In this blog post, you will learn by the hand of a use case about how connecting your siloed departmental data with external authoritative resources will leverage the value of your content assets. Visit us at PhUSE EU Connect 2018, where we will introduce the innovative approach of PoolParty Semantic Suite to make the most out of your data with semantic data integration. Stay tuned for upcoming blog posts that will help you understand how knowledge graphs and AI can leverage your organization. Our partner Findwise, global experts in search-driven solutions for the pharmaceutical and healthcare industry, are bringing all their expertise in information management and knowledge engineering into this blog post series. A smart semantic information engine will connect a variety of information systems relevant within the pharmaceutical and healthcare industry.
Semantic Role Labeling for Knowledge Graph Extraction from Text
Alam, Mehwish, Gangemi, Aldo, Presutti, Valentina, Recupero, Diego Reforgiato
This paper introduces TakeFive, a new semantic role labeling method that transforms a text into a frame-oriented knowledge graph. It performs dependency parsing, identifies the words that evoke lexical frames, locates the roles and fillers for each frame, runs coercion techniques, and formalises the results as a knowledge graph. This formal representation complies with the frame semantics used in Framester, a factual-linguistic linked data resource. The obtained precision, recall and F1 values indicate that TakeFive is competitive with other existing methods such as SEMAFOR, Pikes, PathLSTM and FRED. We finally discuss how to combine TakeFive and FRED, obtaining higher values of precision, recall and F1. Keywords: Semantic Role Labeling, Frame Semantics, Framester, Dependency Parsing, Role Oriented Knowledge Graphs 1. Introduction Most knowledge in linked data and knowledge graphs is of a relational nature: people participating in events, products having prices, artifacts with parts, works of art produced by artists, beers sold at a bar, etc. For that reason, a good part of integration and interoperability ends up consisting in aligning relations among heterogeneous schemas and data. This limit makes interoperability difficult.
Logic Attention Based Neighborhood Aggregation for Inductive Knowledge Graph Embedding
Wang, Peifeng, Han, Jialong, Li, Chenliang, Pan, Rong
Knowledge graph embedding aims at modeling entities and relations with low-dimensional vectors. Most previous methods require that all entities should be seen during training, which is unpractical for real-world knowledge graphs with new entities emerging on a daily basis. Recent efforts on this issue suggest training a neighborhood aggregator in conjunction with the conventional entity and relation embeddings, which may help embed new entities inductively via their existing neighbors. However, their neighborhood aggregators neglect the unordered and unequal natures of an entity's neighbors. To this end, we summarize the desired properties that may lead to effective neighborhood aggregators. We also introduce a novel aggregator, namely, Logic Attention Network (LAN), which addresses the properties by aggregating neighbors with both rules- and network-based attention weights. By comparing with conventional aggregators on two knowledge graph completion tasks, we experimentally validate LAN's superiority in terms of the desired properties.