scholarly journals Incoherency Problems in a Combination of Description Logics and Rules

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Shasha Huang ◽  
Jing Hao ◽  
Dang Luo
Keyword(s):  
Knowledge Base ◽  
Description Logics ◽  
Knowledge Bases ◽  
Combination Method ◽  
Trust Level ◽  
Level Information ◽  
The Relationship

A paraconsistent semantics has been presented for hybrid MKNF knowledge bases—a combination method for description logics and rules. However, it is invalid when incoherency occurs in the knowledge base. In this paper, we introduce a semi-S5semantics for hybrid MKNF knowledge bases on the basis of nine-valued lattice, such that it is paraconsistent for incoherent knowledge base. It is shown that a semi-S5model can be computed via a fixpoint operator and is in fact a paraconsistent MKNF model when the knowledge base is incoherent. Moreover, we apply six-valued lattice to hybrid MKNF knowledge bases and present a suspicious semantics to distinguish different trust level information. At last, we investigate the relationship between suspicious semantics and paraconsistent semantics.

scholarly journals A Framework for Reasoning about Dynamic Axioms in Description Logics

2020 ◽  
Author(s):  
Bartosz Bednarczyk ◽  
Stephane Demri ◽  
Alessio Mansutti
Keyword(s):  
Knowledge Representation ◽  
Knowledge Base ◽  
Data Structures ◽  
Description Logics ◽  
Knowledge Bases ◽  
Dynamic Data Structures ◽  
Dynamic Data ◽  
Logical Connectives ◽  
Consistency Problem ◽  
Natural Means

Description logics are well-known logical formalisms for knowledge representation. We propose to enrich knowledge bases (KBs) with dynamic axioms that specify how the satisfaction of statements from the KBs evolves when the interpretation is decomposed or recomposed, providing a natural means to predict the evolution of interpretations. Our dynamic axioms borrow logical connectives from separation logics, well-known specification languages to verify programs with dynamic data structures. In the paper, we focus on ALC and EL augmented with dynamic axioms, or to their subclass of positive dynamic axioms. The knowledge base consistency problem in the presence of dynamic axioms is investigated, leading to interesting complexity results, among which the problem for EL with positive dynamic axioms is tractable, whereas EL with dynamic axioms is undecidable.

scholarly journals The Construction and Globalization of the Knowlege Base in Interhuman Communication Systems

2003 ◽  
Vol 28 (3) ◽  
Author(s):  
Loet Leydesdorff
Keyword(s):  
Knowledge Base ◽  
Communication Systems ◽  
Communication Theory ◽  
Human Language ◽  
Production Of Knowledge ◽  
Nous Permet ◽  
Level Information ◽  
The Relationship

Abstract: The relationship between the knowledge base and the globalization of communication systems is discussed from the perspective of communication theory. The author argues that interhuman communication takes place at two levels. At the first level information is exchanged and provided with meaning, and at the second level meaning can reflexively be communicated. Human language can be considered as the evolutionary achievement that enables us to use these two channels of communication simultaneously. Providing meaning from the perspective of hindsight is a recursive operation: a meaning that makes a difference can be considered as knowledge. If the production of knowledge is socially organized, the perspective of hindsight can further be codified. This adds globalization to the historically stabilized patterns of communications. Résumé : L'auteur décrit la relation entre la base de savoir et la mondialisation des systèmes de communication en recourant à la perspective offerte par la théorie de la communication. L'auteur soutient que la communication entre humains a lieu à deux niveaux. Au premier, on échange l'information et on lui donne du sens, et au second le sens peut se communiquer réflexivement. Il est possible de considérer la langue humaine comme étant l'accomplissement d'une évolution qui nous permet d'utiliser ces deux niveaux de communication simultanément. Donner du sens en prenant du recul est une opération récursive et, d'autre part, on peut considérer tout sens qui fait une différence comme du savoir. Dans la mesure où la production du savoir s'organise socialement, on peut codifier davantage la perspective permise par le recul. Cette codification accrue permet à la mondialisation d'avoir un effet sur les savoirs historiquement stabilisés des communications.

scholarly journals The role of semantics in mining frequent patterns from knowledge bases in description logics with rules

2010 ◽  
Vol 10 (3) ◽  
pp. 251-289 ◽  
Author(s):  
JOANNA JÓZEFOWSKA ◽  
AGNIESZKA ŁAWRYNOWICZ ◽  
TOMASZ ŁUKASZEWSKI
Keyword(s):  
Data Mining ◽  
Semantic Web ◽  
Knowledge Base ◽  
Description Logics ◽  
Pattern Discovery ◽  
Knowledge Bases ◽  
Frequent Pattern ◽  
Frequent Patterns ◽  
Representation Formalism

AbstractWe propose a new method for mining frequent patterns in a language that combines both Semantic Web ontologies and rules. In particular, we consider the setting of using a language that combines description logics (DLs) with DL-safe rules. This setting is important for the practical application of data mining to the Semantic Web. We focus on the relation of the semantics of the representation formalism to the task of frequent pattern discovery, and for the core of our method, we propose an algorithm that exploits the semantics of the combined knowledge base. We have developed a proof-of-concept data mining implementation of this. Using this we have empirically shown that using the combined knowledge base to perform semantic tests can make data mining faster by pruning useless candidate patterns before their evaluation. We have also shown that the quality of the set of patterns produced may be improved: the patterns are more compact, and there are fewer patterns. We conclude that exploiting the semantics of a chosen representation formalism is key to the design and application of (onto-)relational frequent pattern discovery methods.

Open Knowledge Base: Resources and Units of Knowledge

2020 ◽  
Author(s):  
Matheus Pereira Lobo
Keyword(s):  
Knowledge Base ◽  
Knowledge Bases

This paper is about highlighting two categories of knowledge bases, one built as a repository of links, and other based on units of knowledge.

scholarly journals PENGARUH KORUPSI, DEMOKRASI DAN POLITIK TERHADAP KEMISKINAN DI DELAPAN NEGARA ASEAN DENGAN PERTUMBUHAN EKONOMI SEBAGAI VARIABEL MODERASI

2019 ◽  
Vol 1 (3) ◽  
pp. 845
Author(s):  
Yolanda Yolanda
Keyword(s):  
Economic Growth ◽  
Time Series Data ◽  
Predictor Variable ◽  
Combination Method ◽  
Annual Reports ◽  
Series Data ◽  
Transparency International ◽  
Negative Effect ◽  
Asean Countries ◽  
The Relationship

This study aims the influence of corruption, democracy and politics on poverty in ASEAN countries with economic growth as a moderating variable. The method used is using the panel regression model. This data uses a combination method between time series data from 2013 - 2016 and a cross section consisting of 8 countries. Data obtained from World Bank annual reports, Transparency International and Freedom House. The results of this study indicate that (1) Corruption Perception Index (CPI) has a significant and negative effect on poverty, meaning that if the CPI increases then poverty will decrease (2) Democracy has no significant and negative effect on poverty. This means that if democracy increases, poverty will decrease (3) Politics has a significant and negative effect on poverty, meaning that if politics increases, poverty will decrease (4) Economic growth has a significant and positive effect on poverty, meaning if economic growth increases then poverty will decline (3) Economic growth unable to moderate the relationship between corruption, democracy and politics towards poverty in 8 ASEAN countries. Economic growth as an interaction variable is a predictor variable (Predictor Moderate Variable), which means that economic growth is only an independent variable.

scholarly journals Building an OWL ontology with Xper3

2018 ◽  
Vol 2 ◽  
pp. e25614 ◽  
Author(s):  
Florian Pellen ◽  
Sylvain Bouquin ◽  
Isabelle Mougenot ◽  
Régine Vignes-Lebbe
Keyword(s):  
Semantic Web ◽  
Knowledge Base ◽  
Expressive Power ◽  
Knowledge Bases ◽  
User Friendliness ◽  
Standard Format ◽  
Ontology Language ◽  
Closed World ◽  
Web Standards ◽  
Description Framework

Xper3 (Vignes Lebbe et al. 2016) is a collaborative knowledge base publishing platform that, since its launch in november 2013, has been adopted by over 2 thousand users (Pinel et al. 2017). This is mainly due to its user friendly interface and the simplicity of its data model. The data are stored in MySQL Relational DBs, but the exchange format uses the TDWG standard format SDD (Structured Descriptive DataHagedorn et al. 2005). However, each Xper3 knowledge base is a closed world that the author(s) may or may not share with the scientific community or the public via publishing content and/or identification key (Kopfstein 2016). The explicit taxonomic, geographic and phenotypic limits of a knowledge base are not always well defined in the metadata fields. Conversely terminology vocabularies, such as Phenotype and Trait Ontology PATO and the Plant Ontology PO, and software to edit them, such as Protégé and Phenoscape, are essential in the semantic web, but difficult to handle for biologist without computer skills. These ontologies constitute open worlds, and are expressed themselves by RDF triples (Resource Description Framework). Protégé offers vizualisation and reasoning capabilities for these ontologies (Gennari et al. 2003, Musen 2015). Our challenge is to combine the user friendliness of Xper3 with the expressive power of OWL (Web Ontology Language), the W3C standard for building ontologies. We therefore focused on analyzing the representation of the same taxonomic contents under Xper3 and under different models in OWL. After this critical analysis, we chose a description model that allows automatic export of SDD to OWL and can be easily enriched. We will present the results obtained and their validation on two knowledge bases, one on parasitic crustaceans (Sacculina) and the second on current ferns and fossils (Corvez and Grand 2014). The evolution of the Xper3 platform and the perspectives offered by this link with semantic web standards will be discussed.

scholarly journals Querying and Repairing Inconsistent Prioritized Knowledge Bases: Complexity Analysis and Links with Abstract Argumentation

2020 ◽  
Author(s):  
Meghyn Bienvenu ◽  
Camille Bourgaux
Keyword(s):  
Complexity Analysis ◽  
Knowledge Bases ◽  
Data Complexity ◽  
The Core ◽  
Inconsistency Handling ◽  
Definition Of ◽  
Priority Relation ◽  
Inconsistent Database ◽  
The Relationship ◽  
Computational Properties

In this paper, we explore the issue of inconsistency handling over prioritized knowledge bases (KBs), which consist of an ontology, a set of facts, and a priority relation between conflicting facts. In the database setting, a closely related scenario has been studied and led to the definition of three different notions of optimal repairs (global, Pareto, and completion) of a prioritized inconsistent database. After transferring the notions of globally-, Pareto- and completion-optimal repairs to our setting, we study the data complexity of the core reasoning tasks: query entailment under inconsistency-tolerant semantics based upon optimal repairs, existence of a unique optimal repair, and enumeration of all optimal repairs. Our results provide a nearly complete picture of the data complexity of these tasks for ontologies formulated in common DL-Lite dialects. The second contribution of our work is to clarify the relationship between optimal repairs and different notions of extensions for (set-based) argumentation frameworks. Among our results, we show that Pareto-optimal repairs correspond precisely to stable extensions (and often also to preferred extensions), and we propose a novel semantics for prioritized KBs which is inspired by grounded extensions and enjoys favourable computational properties. Our study also yields some results of independent interest concerning preference-based argumentation frameworks.

scholarly journals Improving the Quality of Linked Data Using Statistical Distributions

2018 ◽  
pp. 1638-1664 ◽  
Author(s):  
Heiko Paulheim ◽  
Christian Bizer
Keyword(s):  
Knowledge Base ◽  
Linked Data ◽  
Relational Databases ◽  
Knowledge Bases ◽  
Structured Data ◽  
Data Sources ◽  
Data Sets ◽  
Statistical Distributions ◽  
The Web

Linked Data on the Web is either created from structured data sources (such as relational databases), from semi-structured sources (such as Wikipedia), or from unstructured sources (such as text). In the latter two cases, the generated Linked Data will likely be noisy and incomplete. In this paper, we present two algorithms that exploit statistical distributions of properties and types for enhancing the quality of incomplete and noisy Linked Data sets: SDType adds missing type statements, and SDValidate identifies faulty statements. Neither of the algorithms uses external knowledge, i.e., they operate only on the data itself. We evaluate the algorithms on the DBpedia and NELL knowledge bases, showing that they are both accurate as well as scalable. Both algorithms have been used for building the DBpedia 3.9 release: With SDType, 3.4 million missing type statements have been added, while using SDValidate, 13,000 erroneous RDF statements have been removed from the knowledge base.

scholarly journals Formal Query Building with Query Structure Prediction for Complex Question Answering over Knowledge Base

2020 ◽  
Author(s):  
Yongrui Chen ◽  
Huiying Li ◽  
Yuncheng Hua ◽  
Guilin Qi
Keyword(s):  
Knowledge Base ◽  
Structure Prediction ◽  
Question Answering ◽  
State Transition ◽  
Knowledge Bases ◽  
Second Stage ◽  
Transition Strategy ◽  
Query Structure ◽  
Two Stages ◽  
Complex Question

Formal query building is an important part of complex question answering over knowledge bases. It aims to build correct executable queries for questions. Recent methods try to rank candidate queries generated by a state-transition strategy. However, this candidate generation strategy ignores the structure of queries, resulting in a considerable number of noisy queries. In this paper, we propose a new formal query building approach that consists of two stages. In the first stage, we predict the query structure of the question and leverage the structure to constrain the generation of the candidate queries. We propose a novel graph generation framework to handle the structure prediction task and design an encoder-decoder model to predict the argument of the predetermined operation in each generative step. In the second stage, we follow the previous methods to rank the candidate queries. The experimental results show that our formal query building approach outperforms existing methods on complex questions while staying competitive on simple questions.

Sign in / Sign up

Export Citation Format

Share Document