Ontologies


On2Vec: Embedding-based Relation Prediction for Ontology Population

arXiv.org Artificial Intelligence

Populating ontology graphs represents a long-standing problem for the Semantic Web community. Recent advances in translation-based graph embedding methods for populating instance-level knowledge graphs lead to promising new approaching for the ontology population problem. However, unlike instance-level graphs, the majority of relation facts in ontology graphs come with comprehensive semantic relations, which often include the properties of transitivity and symmetry, as well as hierarchical relations. These comprehensive relations are often too complex for existing graph embedding methods, and direct application of such methods is not feasible. Hence, we propose On2Vec, a novel translation-based graph embedding method for ontology population. On2Vec integrates two model components that effectively characterize comprehensive relation facts in ontology graphs. The first is the Component-specific Model that encodes concepts and relations into low-dimensional embedding spaces without a loss of relational properties; the second is the Hierarchy Model that performs focused learning of hierarchical relation facts. Experiments on several well-known ontology graphs demonstrate the promising capabilities of On2Vec in predicting and verifying new relation facts. These promising results also make possible significant improvements in related methods.


AI Knowledge Map: How To Classify AI Technologies

#artificialintelligence

I have been in the space of artificial intelligence for a while and am aware that multiple classifications, distinctions, landscapes, and infographics exist to represent and track the different ways to think about AI. However, I am not a big fan of those categorization exercises, mainly because I tend to think that the effort of classifying dynamic data points into predetermined fixed boxes is often not worth the benefits of having such a "clear" framework (this is a generalization of course as sometimes they are extremely useful). I also believe this landscape is useful for people new to the space to grasp at-a-glance the complexity and depth of this topic, as well as for those more experienced to have a reference point and to create new conversations around specific technologies. What follows is then an effort to draw an architecture to access knowledge on AI and follow emergent dynamics, a gateway of pre-existing knowledge on the topic that will allow you to scout around for additional information and eventually create new knowledge on AI. I call it the AI Knowledge Map (AIKM).


Rule-based OWL Modeling with ROWLTab Protege Plugin

arXiv.org Artificial Intelligence

It has been argued that it is much easier to convey logical statements using rules rather than OWL (or description logic (DL)) axioms. Based on recent theoretical developments on transformations between rules and DLs, we have developed ROWLTab, a Protege plugin that allows users to enter OWL axioms by way of rules; the plugin then automatically converts these rules into OWL 2 DL axioms if possible, and prompts the user in case such a conversion is not possible without weakening the semantics of the rule. In this paper, we present ROWLTab, together with a user evaluation of its effectiveness compared to entering axioms using the standard Protege interface. Our evaluation shows that modeling with ROWLTab is much quicker than the standard interface, while at the same time, also less prone to errors for hard modeling tasks.


WATCH: Data ontology vs. machine learning and AI, part 2

#artificialintelligence

Tavi Truman, CTO and chief architect at RocketUrBiz, delves further into data ontology and artificial intelligence in the second part of the ICSF Hacker Connect session, "Living in a world without silos: Data ontology vs. machine learning and AI."


OWLAx: A Protege Plugin to Support Ontology Axiomatization through Diagramming

arXiv.org Artificial Intelligence

Once the conceptual overview, in terms of a somewhat informal class diagram, has been designed in the course of engineering an ontology, the process of adding many of the appropriate logical axioms is mostly a routine task. We provide a Protege plugin which supports this task, together with a visual user interface, based on established methods for ontology design pattern modeling.


Modeling OWL with Rules: The ROWL Protege Plugin

arXiv.org Artificial Intelligence

In our experience, some ontology users find it much easier to convey logical statements using rules rather than OWL (or description logic) axioms. Based on recent theoretical developments on transformations between rules and description logics, we develop ROWL, a Protege plugin that allows users to enter OWL axioms by way of rules; the plugin then automatically converts these rules into OWL DL axioms if possible, and prompts the user in case such a conversion is not possible without weakening the semantics of the rule.


AI Knowledge Map: How To Classify AI Technologies

#artificialintelligence

I have been in the space of artificial intelligence for a while and am aware that multiple classifications, distinctions, landscapes, and infographics exist to represent and track the different ways to think about AI. However, I am not a big fan of those categorization exercises, mainly because I tend to think that the effort of classifying dynamic data points into predetermined fixed boxes is often not worth the benefits of having such a "clear" framework (this is a generalization of course as sometimes they are extremely useful). I also believe this landscape is useful for people new to the space to grasp at-a-glance the complexity and depth of this topic, as well as for those more experienced to have a reference point and to create new conversations around specific technologies. What follows is then an effort to draw an architecture to access knowledge on AI and follow emergent dynamics, a gateway of pre-existing knowledge on the topic that will allow you to scout around for additional information and eventually create new knowledge on AI. I call it the AI Knowledge Map (AIKM).



AI Knowledge Map: How To Classify AI Technologies

#artificialintelligence

I have been in the space of artificial intelligence for a while and am aware that multiple classifications, distinctions, landscapes, and infographics exist to represent and track the different ways to think about AI. However, I am not a big fan of those categorization exercises, mainly because I tend to think that the effort of classifying dynamic data points into predetermined fixed boxes is often not worth the benefits of having such a "clear" framework (this is a generalization of course as sometimes they are extremely useful). I also believe this landscape is useful for people new to the space to grasp at-a-glance the complexity and depth of this topic, as well as for those more experienced to have a reference point and to create new conversations around specific technologies. What follows is then an effort to draw an architecture to access knowledge on AI and follow emergent dynamics, a gateway of pre-existing knowledge on the topic that will allow you to scout around for additional information and eventually create new knowledge on AI. I call it the AI Knowledge Map (AIKM).


Applying the Closed World Assumption to SUMO-based Ontologies

arXiv.org Artificial Intelligence

In commonsense knowledge representation, the Open World Assumption is adopted as a general standard strategy for the design, construction and use of ontologies, e.g. in OWL. This strategy limits the inferencing capabilities of any system using these ontologies because non-asserted statements could be assumed to be alternatively true or false in different interpretations. In this paper, we investigate the application of the Closed World Assumption to enable a better exploitation of the structural knowledge encoded in a SUMO-based ontology. To that end, we explore three different Closed World Assumption formulations for subclass and disjoint relations in order to reduce the ambiguity of the knowledge encoded in first-order logic ontologies. We evaluate these formulations on a practical experimentation using a very large commonsense benchmark automatically obtained from the knowledge encoded in WordNet through its mapping to SUMO. The results show that the competency of the ontology improves more than 47 % when reasoning under the Closed World Assumption. As conclusion, applying the Closed World Assumption automatically to first-order logic ontologies reduces their expressed ambiguity and more commonsense questions can be answered.