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 Ontologies


The KnowWhereGraph Ontology

arXiv.org Artificial Intelligence

KnowWhereGraph is one of the largest fully publicly available geospatial knowledge graphs. It includes data from 30 layers on natural hazards (e.g., hurricanes, wildfires), climate variables (e.g., air temperature, precipitation), soil properties, crop and land-cover types, demographics, and human health, various place and region identifiers, among other themes. These have been leveraged through the graph by a variety of applications to address challenges in food security and agricultural supply chains; sustainability related to soil conservation practices and farm labor; and delivery of emergency humanitarian aid following a disaster. In this paper, we introduce the ontology that acts as the schema for KnowWhereGraph. This broad overview provides insight into the requirements and design specifications for the graph and its schema, including the development methodology (modular ontology modeling) and the resources utilized to implement, materialize, and deploy KnowWhereGraph with its end-user interfaces and public query SPARQL endpoint.


A Pattern to Align Them All: Integrating Different Modalities to Define Multi-Modal Entities

arXiv.org Artificial Intelligence

The ability to reason with and integrate different sensory inputs is the foundation underpinning human intelligence and it is the reason for the growing interest in modelling multi-modal information within Knowledge Graphs. Multi-Modal Knowledge Graphs extend traditional Knowledge Graphs by associating an entity with its possible modal representations, including text, images, audio, and videos, all of which are used to convey the semantics of the entity. Despite the increasing attention that Multi-Modal Knowledge Graphs have received, there is a lack of consensus about the definitions and modelling of modalities, whose definition is often determined by application domains. In this paper, we propose a novel ontology design pattern that captures the separation of concerns between an entity (and the information it conveys), whose semantics can have different manifestations across different media, and its realisation in terms of a physical information entity. By introducing this abstract model, we aim to facilitate the harmonisation and integration of different existing multi-modal ontologies which is crucial for many intelligent applications across different domains spanning from medicine to digital humanities.


Explainable Moral Values: a neuro-symbolic approach to value classification

arXiv.org Artificial Intelligence

This work explores the integration of ontology-based reasoning and Machine Learning techniques for explainable value classification. By relying on an ontological formalization of moral values as in the Moral Foundations Theory, relying on the DnS Ontology Design Pattern, the \textit{sandra} neuro-symbolic reasoner is used to infer values (fomalized as descriptions) that are \emph{satisfied by} a certain sentence. Sentences, alongside their structured representation, are automatically generated using an open-source Large Language Model. The inferred descriptions are used to automatically detect the value associated with a sentence. We show that only relying on the reasoner's inference results in explainable classification comparable to other more complex approaches. We show that combining the reasoner's inferences with distributional semantics methods largely outperforms all the baselines, including complex models based on neural network architectures. Finally, we build a visualization tool to explore the potential of theory-based values classification, which is publicly available at http://xmv.geomeaning.com/.


Can Structured Data Reduce Epistemic Uncertainty?

arXiv.org Artificial Intelligence

One of the main issues with the current In the current era of Large Language Models (LLMs), with retrieval approaches using Retrieval-Augmented Generation an abundance of data, there is always a tricky question to is hallucination, where the model gives out irrelevant, be addressed: Is providing an abundance of data enough to incorrect, and unreal responses. By incorporating subsumptions solve complex tasks? The majority of modern-day models in the prompt, we ensure hallucination is minimized are fundamentally probabilistic, which though highly powerful and the response of the Language Model is more contextually in its way, gives the model only an uncertain output and factually intact. Section 4 presents key insights that cannot be reasoned out. This uncertainty is of 2 from our experimentation with ontologies in the medical domain, types, epistemic (EU) and aleatoric (AU), where the former demonstrating how our methodology could be used is also called reducible uncertainty, caused due to the lack of for quicker training and reducing hallucinations in LLMs.


Using off-the-shelf LLMs to query enterprise data by progressively revealing ontologies

arXiv.org Artificial Intelligence

Using Large Language Models (LLMs) to generate database queries is an area of active research. In [4], Sequeda et al. argue that knowledge graphs (KGs) with rich ontologies can enable an LLM to answer queries of enterprise complexity, noting that text-to-SQL benchmarks such as Spider [6] are not tailored to such queries. In addition to query complexity, an equally challenging problem in the enterprise setting is schema complexity, where the ontology itself is large and complex. This paper contributes an approach to using off-the-shelf LLMs and enterprise-scale ontologies to answer natural language questions on large data sets. We address the schema complexity problem by incrementally revealing "just enough" of an ontology that is needed to answer a given question.


Continual Learning with Evolving Class Ontologies

Neural Information Processing Systems

Lifelong learners must recognize concept vocabularies that evolve over time. A common yet underexplored scenario is learning with class labels that continually refine/expand old classes. For example, humans learn to recognize {\tt dog} before dog breeds. In practical settings, dataset {\it versioning} often introduces refinement to ontologies, such as autonomous vehicle benchmarks that refine a previous {\tt vehicle} class into {\tt school-bus} as autonomous operations expand to new cities. This paper formalizes a protocol for studying the problem of {\it Learning with Evolving Class Ontology} (LECO).


Towards Assurance of LLM Adversarial Robustness using Ontology-Driven Argumentation

arXiv.org Artificial Intelligence

Despite the impressive adaptability of large language models (LLMs), challenges remain in ensuring their security, transparency, and interpretability. Given their susceptibility to adversarial attacks, LLMs need to be defended with an evolving combination of adversarial training and guardrails. However, managing the implicit and heterogeneous knowledge for continuously assuring robustness is difficult. We introduce a novel approach for assurance of the adversarial robustness of LLMs based on formal argumentation. Using ontologies for formalization, we structure state-of-the-art attacks and defenses, facilitating the creation of a human-readable assurance case, and a machine-readable representation. We demonstrate its application with examples in English language and code translation tasks, and provide implications for theory and practice, by targeting engineers, data scientists, users, and auditors.


Improving the portability of predicting students performance models by using ontologies

arXiv.org Artificial Intelligence

One of the main current challenges in Educational Data Mining and Learning Analytics is the portability or transferability of predictive models obtained for a particular course so that they can be applied to other different courses. To handle this challenge, one of the foremost problems is the models excessive dependence on the low-level attributes used to train them, which reduces the models portability. To solve this issue, the use of high level attributes with more semantic meaning, such as ontologies, may be very useful. Along this line, we propose the utilization of an ontology that uses a taxonomy of actions that summarises students interactions with the Moodle learning management system. We compare the results of this proposed approach against our previous results when we used low-level raw attributes obtained directly from Moodle logs. The results indicate that the use of the proposed ontology improves the portability of the models in terms of predictive accuracy. The main contribution of this paper is to show that the ontological models obtained in one source course can be applied to other different target courses with similar usage levels without losing prediction accuracy.


Bottom-up Anytime Discovery of Generalised Multimodal Graph Patterns for Knowledge Graphs

arXiv.org Artificial Intelligence

Vast amounts of heterogeneous knowledge are becoming publicly available in the form of knowledge graphs, often linking multiple sources of data that have never been together before, and thereby enabling scholars to answer many new research questions. It is often not known beforehand, however, which questions the data might have the answers to, potentially leaving many interesting and novel insights to remain undiscovered. To support scholars during this scientific workflow, we introduce an anytime algorithm for the bottom-up discovery of generalized multimodal graph patterns in knowledge graphs. Each pattern is a conjunction of binary statements with (data-) type variables, constants, and/or value patterns. Upon discovery, the patterns are converted to SPARQL queries and presented in an interactive facet browser together with metadata and provenance information, enabling scholars to explore, analyse, and share queries. We evaluate our method from a user perspective, with the help of domain experts in the humanities.


Open Digital Rights Enforcement Framework (ODRE): from descriptive to enforceable policies

arXiv.org Artificial Intelligence

From centralised platforms to decentralised ecosystems, like Data Spaces, sharing data has become a paramount challenge. For this reason, the definition of data usage policies has become crucial in these domains, highlighting the necessity of effective policy enforcement mechanisms. The Open Digital Rights Language (ODRL) is a W3C standard ontology designed to describe data usage policies, however, it lacks built-in enforcement capabilities, limiting its practical application. This paper introduces the Open Digital Rights Enforcement (ODRE) framework, whose goal is to provide ODRL with enforcement capabilities. The ODRE framework proposes a novel approach to express ODRL policies that integrates the descriptive ontology terms of ODRL with other languages that allow behaviour specification, such as dynamic data handling or function evaluation. The framework includes an enforcement algorithm for ODRL policies and two open-source implementations in Python and Java. The ODRE framework is also designed to support future extensions of ODRL to specific domain scenarios. In addition, current limitations of ODRE, ODRL, and current challenges are reported. Finally, to demonstrate the enforcement capabilities of the implementations, their performance, and their extensibility features, several experiments have been carried out with positive results.