# Ontologies

### Iteratively Learning Embeddings and Rules for Knowledge Graph Reasoning

Reasoning is essential for the development of large knowledge graphs, especially for completion, which aims to infer new triples based on existing ones. Both rules and embeddings can be used for knowledge graph reasoning and they have their own advantages and difficulties. Rule-based reasoning is accurate and explainable but rule learning with searching over the graph always suffers from efficiency due to huge search space. Embedding-based reasoning is more scalable and efficient as the reasoning is conducted via computation between embeddings, but it has difficulty learning good representations for sparse entities because a good embedding relies heavily on data richness. Based on this observation, in this paper we explore how embedding and rule learning can be combined together and complement each other's difficulties with their advantages. We propose a novel framework IterE iteratively learning embeddings and rules, in which rules are learned from embeddings with proper pruning strategy and embeddings are learned from existing triples and new triples inferred by rules. Evaluations on embedding qualities of IterE show that rules help improve the quality of sparse entity embeddings and their link prediction results. We also evaluate the efficiency of rule learning and quality of rules from IterE compared with AMIE+, showing that IterE is capable of generating high quality rules more efficiently. Experiments show that iteratively learning embeddings and rules benefit each other during learning and prediction.

### Towards a Forensic Event Ontology to Assist Video Surveillance-based Vandalism Detection

In the context of vandalism and terrorist activities, video surveillance forms an integral part of any incident investigation and, thus, there is a critical need for developing an "automated video surveillance system" with the capability of detecting complex events to aid the forensic investigators in solving the criminal cases. As an example, in the aftermath of the London riots in August 2011 police had to scour through more than 200,000 hours of CCTV videos to identify suspects. Around 5,000 offenders were found by trawling through the footage, after a process that took more than five months. With the aim to develop an open and expandable video analysis framework equipped with tools for analysing, recognising, extracting and classifying events in video, which can be used for searching during investigations with unpredictable characteristics, or exploring normative (or abnormal) behaviours, several efforts for standardising event representation from surveillance footage have been made [9, 10, 11, 22, 23, 28, 30, 37]. While various approaches have relied on offering foundational support for the domain ontology extension, to the best of our knowledge, a systematic ontology for standardising the event vocabulary for forensic analysis and an application of it has not been presented in the literature so far. In this paper, we present an OWL 2 [25] ontology for the semantic retrieval of complex events to aid video surveillance-based vandalism detection.

### Ontology of Card Sleights

We present a machine-readable movement writing for sleight-of-hand moves with cards -- a "Labanotation of card magic." This scheme of movement writing contains 440 categories of motion, and appears to taxonomize all card sleights that have appeared in over 1500 publications. The movement writing is axiomatized in $\mathcal{SROIQ}$(D) Description Logic, and collected formally as an Ontology of Card Sleights, a computational ontology that extends the Basic Formal Ontology and the Information Artifact Ontology. The Ontology of Card Sleights is implemented in OWL DL, a Description Logic fragment of the Web Ontology Language. While ontologies have historically been used to classify at a less granular level, the algorithmic nature of card tricks allows us to transcribe a performer's actions step by step. We conclude by discussing design criteria we have used to ensure the ontology can be accessed and modified with a simple click-and-drag interface. This may allow database searches and performance transcriptions by users with card magic knowledge, but no ontology background.

### Taxonomies, Ontologies And Machine Learning: The Future Of Knowledge Management

As an ontologist, I'm often asked about the distinctions between taxonomies and ontologies, and whether ontologies are replacing taxonomies. The second question is easy to answer: "No." Both taxonomies and ontologies serve vital, and often complementary, roles ... if they are used right. A taxonomy is, to put it simply, a categorization scheme. Most readers should be familiar with a few critical taxonomies such as the Linnaeus Taxonomy used to represent how animals are related to one another, and the Dewey Decimal System for libraries, which represents subject areas of interest.

### WebProt\'eg\'e: A Cloud-Based Ontology Editor

We present WebProt\'eg\'e, a tool to develop ontologies represented in the Web Ontology Language (OWL). WebProt\'eg\'e is a cloud-based application that allows users to collaboratively edit OWL ontologies, and it is available for use at https://webprotege.stanford.edu. WebProt\'ege\'e currently hosts more than 68,000 OWL ontology projects and has over 50,000 user accounts. In this paper, we detail the main new features of the latest version of WebProt\'eg\'e.

### Major Chinese Global Digital Services Join Yext Knowledge Network in Spring '19 Product Release

Yext, Inc., a Digital Knowledge Management (DKM) firm, announced integrations with some of the largest global digital services used by Chinese travelers around the world, as part of Yext's Spring '19 Product Release. The integrations with Baidu Map (Overseas), Fliggy, CK Map, and PIRT put businesses outside China in control of their brand information in the services that hundreds of millions of Chinese travelers all across the globe use to find places to eat, shop, stay, and more. "The Chinese digital landscape is made up of an entirely different set of services from those in the West. When Chinese travelers who use services like Baidu and Fliggy at home travel overseas, they use these same services to find businesses in the cities they are visiting," said Howard Lerman, Founder and CEO of Yext. "If a business's information isn't in these services, it is invisible to these potential customers. We're integrating with some of the largest Chinese services so businesses using Yext can provide perfect answers to Chinese travelers."

### EL Embeddings: Geometric construction of models for the Description Logic EL ++

An embedding is a function that maps entities from one algebraic structure into another while preserving certain characteristics. Embeddings are being used successfully for mapping relational data or text into vector spaces where they can be used for machine learning, similarity search, or similar tasks. We address the problem of finding vector space embeddings for theories in the Description Logic $\mathcal{EL}^{++}$ that are also models of the TBox. To find such embeddings, we define an optimization problem that characterizes the model-theoretic semantics of the operators in $\mathcal{EL}^{++}$ within $\Re^n$, thereby solving the problem of finding an interpretation function for an $\mathcal{EL}^{++}$ theory given a particular domain $\Delta$. Our approach is mainly relevant to large $\mathcal{EL}^{++}$ theories and knowledge bases such as the ontologies and knowledge graphs used in the life sciences. We demonstrate that our method can be used for improved prediction of protein--protein interactions when compared to semantic similarity measures or knowledge graph embedding

### Artificial Intelligence: The Revolution for SMEs - A Business Knowledge Network Event

AI - 'artificial intelligence' - promises to bring revolution to many parts of our lives: Smart assistants, fully robotic workplaces, driverless cars, "fake news" propaganda. As the digital world around us becomes smarter, what are the implications socially & economically? And what does the future really hold for us in a world of AI? This interesting and informative talk is delivered by Sven Latham from Noggin. Sven is a self-confessed data and computer geek, using big data & AI to analyse town centres.

### DIALOG: A framework for modeling, analysis and reuse of digital forensic knowledge

This paper presents DIALOG (Digital Investigation Ontology); a framework for the management, reuse, and analysis of Digital Investigation knowledge. DIALOG provides a general, application independent vocabulary that can be used to describe an investigation at different levels of detail. DIALOG is defined to encapsulate all concepts of the digital forensics field and the relationships between them. In particular, we concentrate on the Windows Registry, where registry keys are modeled in terms of both their structure and function. Registry analysis software tools are modeled in a similar manner and we illustrate how the interpretation of their results can be done using the reasoning capabilities of ontology

### Learning Ontologies with Epistemic Reasoning: The EL Case

We investigate the problem of learning description logic ontologies from entailments via queries, using epistemic reasoning. We introduce a new learning model consisting of epistemic membership and example queries and show that polynomial learnability in this model coincides with polynomial learnability in Angluin's exact learning model with membership and equivalence queries. We then instantiate our learning framework to EL and show some complexity results for an epistemic extension of EL where epistemic operators can be applied over the axioms. Finally, we transfer known results for EL ontologies and its fragments to our learning model based on epistemic reasoning.