scholarly journals Explanations for Negative Query Answers under Existential Rules

2020 ◽  
Author(s):  
İsmail İlkan Ceylan ◽  
Thomas Lukasiewicz ◽  
Enrico Malizia ◽  
Cristian Molinaro ◽  
Andrius Vaicenavičius
Keyword(s):  
Knowledge Representation ◽  
Conceptual Knowledge ◽  
Complexity Analysis ◽  
Description Logics ◽  
Query Answering ◽  
Data Sources ◽  
Complexity Measures ◽  
Rule Languages ◽  
Wide Range ◽  
Ontology Languages

Ontology-mediated query answering is an extensively studied paradigm, where the conceptual knowledge provided by an ontology is leveraged towards more enhanced querying of data sources. A major advantage of ontological reasoning is its interpretability, which allows one to derive explanations for query answers. Indeed, explanations have a long history in knowledge representation, and have also been investigated for ontology languages based on description logics and existential rules. Existing works on existential rules, however, merely focus on understanding why a query is entailed, i.e., explaining positive query answers. In this paper, we continue this line of research and address another important problem, namely, explaining why a query is not entailed under existential rules, i.e., explaining negative query answers. We consider various problems related to explaining non-entailments from the abduction literature, and also introduce new problems. For all considered problems, we give a detailed complexity analysis for a wide range of existential rule languages and complexity measures.

scholarly journals Explanations for Inconsistency-Tolerant Query Answering under Existential Rules

2020 ◽  
Vol 34 (03) ◽  
pp. 2909-2916
Author(s):  
Thomas Lukasiewicz ◽  
Enrico Malizia ◽  
Cristian Molinaro
Keyword(s):  
Knowledge Base ◽  
Complexity Analysis ◽  
Knowledge Bases ◽  
Query Answering ◽  
Complexity Measures ◽  
Rule Languages ◽  
Wide Range ◽  
Inconsistent Knowledge

Querying inconsistent knowledge bases is a problem that has attracted a great deal of interest over the last decades. While several semantics of query answering have been proposed, and their complexity is rather well-understood, little attention has been paid to the problem of explaining query answers. Explainability has recently become a prominent problem in different areas of AI. In particular, explaining query answers allows users to understand not only what is entailed by an inconsistent knowledge base, but also why. In this paper, we address the problem of explaining query answers for existential rules under three popular inconsistency-tolerant semantics, namely, the ABox repair, the intersection of repairs, and the intersection of closed repairs semantics. We provide a thorough complexity analysis for a wide range of existential rule languages and for different complexity measures.

scholarly journals Explanations for Query Answers under Existential Rules

2019 ◽  
Author(s):  
İsmail İlkan Ceylan ◽  
Thomas Lukasiewicz ◽  
Enrico Malizia ◽  
Andrius Vaicenavičius
Keyword(s):  
Complexity Analysis ◽  
Query Answering ◽  
Decision Problems ◽  
Logical Theory ◽  
Logical Entailment ◽  
Ontology Languages

Ontology-mediated query answering is an extensively studied paradigm, which aims at improving query answers with the use of a logical theory. As a form of logical entailment, ontology-mediated query answering is fully interpretable, which makes it possible to derive explanations for query answers. Surprisingly, however, explaining answers for ontology-mediated queries has received little attention for ontology languages based on existential rules. In this paper, we close this gap, and study the problem of explaining query answers in terms of minimal subsets of database facts. We provide a thorough complexity analysis for several decision problems associated with minimal explanations under existential rules.

scholarly journals The Application of Complexity Analysis in Brain Blood-Oxygen Signal

2021 ◽  
Vol 11 (11) ◽  
pp. 1415
Author(s):  
Xiaoyang Xin ◽  
Shuyang Long ◽  
Mengdan Sun ◽  
Xiaoqing Gao
Keyword(s):  
Complexity Analysis ◽  
Spatial Scales ◽  
Blood Oxygen ◽  
Complexity Measures ◽  
Future Directions ◽  
Brain Physiology ◽  
Wide Range ◽  
Signal Complexity ◽  
Temporal And Spatial ◽  
The Brain

One of the daunting features of the brain is its physiology complexity, which arises from the interaction of numerous neuronal circuits that operate over a wide range of temporal and spatial scales, enabling the brain to adapt to the constantly changing environment and to perform various cognitive functions. As a reflection of the complexity of brain physiology, the complexity of brain blood-oxygen signal has been frequently studied in recent years. This paper reviews previous literature regarding the following three aspects: (1) whether the complexity of the brain blood-oxygen signal can serve as a reliable biomarker for distinguishing different patient populations; (2) which is the best algorithm for complexity measure? And (3) how to select the optimal parameters for complexity measures. We then discuss future directions for blood-oxygen signal complexity analysis, including improving complexity measurement based on the characteristics of both spatial patterns of brain blood-oxygen signal and latency of complexity itself. In conclusion, the current review helps to better understand complexity analysis in brain blood-oxygen signal analysis and provide useful information for future studies.

Analyzing the linguistic complexity of German learner language in a reading comprehension task

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zarah Weiss ◽  
Detmar Meurers
Keyword(s):  
Reading Comprehension ◽  
Language Proficiency ◽  
Complexity Analysis ◽  
College Level ◽  
Complexity Measures ◽  
Linguistic Complexity ◽  
Foreign Language Learners ◽  
Wide Range ◽  
Linguistic Methods ◽  
Learner Language

Abstract While traditionally linguistic complexity analysis of learner language is mostly based on essays, there is increasing interest in other task types. This is crucial for obtaining a broader empirical basis for characterizing language proficiency and highlights the need to advance our understanding of how task and learner properties interact in shaping the linguistic complexity of learner productions. It also makes it important to determine which complexity measures generalize well across which tasks. In this paper, we investigate the linguistic complexity of answers to reading comprehension questions written by foreign language learners of German at the college level. Analyzing the corpus with computational linguistic methods identifying a wide range of complexity features, we explore which linguistic complexity analyses can successfully be performed for such short answers, how learner proficiency impacts the results, how generalizable they are across different contexts, and how the quality of the underlying analysis impacts the results.

scholarly journals Nominals, Inverses, Counting, and Conjunctive Queries or: Why Infinity is your Friend!

2010 ◽  
Vol 39 ◽  
pp. 429-481 ◽  
Author(s):  
S. Rudolph ◽  
B. Glimm
Keyword(s):  
Knowledge Representation ◽  
Description Logic ◽  
Query Language ◽  
Description Logics ◽  
Knowledge Bases ◽  
Conjunctive Query ◽  
Conjunctive Queries ◽  
Decidability Result ◽  
Wide Range ◽  
Significant Attention

Description Logics are knowledge representation formalisms that provide, for example, the logical underpinning of the W3C OWL standards. Conjunctive queries, the standard query language in databases, have recently gained significant attention as an expressive formalism for querying Description Logic knowledge bases. Several different techniques for deciding conjunctive query entailment are available for a wide range of DLs. Nevertheless, the combination of nominals, inverse roles, and number restrictions in OWL 1 and OWL 2 DL causes unsolvable problems for the techniques hitherto available. We tackle this problem and present a decidability result for entailment of unions of conjunctive queries in the DL ALCHOIQb that contains all three problematic constructors simultaneously. Provided that queries contain only simple roles, our result also shows decidability of entailment of (unions of) conjunctive queries in the logic that underpins OWL 1 DL and we believe that the presented results will pave the way for further progress towards conjunctive query entailment decision procedures for the Description Logics underlying the OWL standards.

scholarly journals Making Cross Products and Guarded Ontology Languages Compatible

2017 ◽  
Author(s):  
Pierre Bourhis ◽  
Michael Morak ◽  
Andreas Pieris
Keyword(s):  
Description Logics ◽  
Order Logic ◽  
Query Answering ◽  
First Order Logic ◽  
First Order ◽  
Ontology Languages ◽  
Guarded Fragment

Cross products form a useful modelling tool that allows us to express natural statements such as "elephants are bigger than mice", or, more generally, to define relations that connect every instance in a relation with every instance in another relation. Despite their usefulness, cross products cannot be expressed using existing guarded ontology languages, such as description logics (DLs) and guarded existential rules. The question that comes up is whether cross products are compatible with guarded ontology languages, and, if not, whether there is a way of making them compatible. This has been already studied for DLs, while for guarded existential rules remains unanswered. Our goal is to give an answer to the above question. To this end, we focus on the guarded fragment of first-order logic (which serves as a unifying framework that subsumes many of the aforementioned ontology languages) extended with cross products, and we investigate the standard tasks of satisfiability and query answering. Interestingly, we isolate relevant fragments that are compatible with cross products.

scholarly journals Entropic measure unveils country competitiveness and product specialization in the World trade web

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gianluca Teza ◽  
Michele Caraglio ◽  
Attilio L. Stella
Keyword(s):  
Iterative Scheme ◽  
Entropy Function ◽  
Bipartite Networks ◽  
Complexity Measures ◽  
Wide Range ◽  
Self Consistent ◽  
Set Up ◽  
Technical Features ◽  
Country Competitiveness ◽  
Entropic Measure

AbstractWe show how the Shannon entropy function can be used as a basis to set up complexity measures weighting the economic efficiency of countries and the specialization of products beyond bare diversification. This entropy function guarantees the existence of a fixed point which is rapidly reached by an iterative scheme converging to our self-consistent measures. Our approach naturally allows to decompose into inter-sectorial and intra-sectorial contributions the country competitivity measure if products are partitioned into larger categories. Besides outlining the technical features and advantages of the method, we describe a wide range of results arising from the analysis of the obtained rankings and we benchmark these observations against those established with other economical parameters. These comparisons allow to partition countries and products into various main typologies, with well-revealed characterizing features. Our methods have wide applicability to general problems of ranking in bipartite networks.

A Set-theoretic Approach to Reasoning Services for the Description Logic 𝒟 ℒ D 4,×

2020 ◽  
Vol 176 (3-4) ◽  
pp. 349-384
Author(s):  
Domenico Cantone ◽  
Marianna Nicolosi-Asmundo ◽  
Daniele Francesco Santamaria
Keyword(s):  
Description Logic ◽  
Description Logics ◽  
Theoretic Approach ◽  
The Novel ◽  
Data Types ◽  
Left Hand ◽  
Rule Languages ◽  
Tableau System ◽  
High Scalability ◽  
Better Than

In this paper we consider the most common TBox and ABox reasoning services for the description logic 𝒟ℒ〈4LQSR,x〉(D) ( 𝒟 ℒ D 4,× , for short) and prove their decidability via a reduction to the satisfiability problem for the set-theoretic fragment 4LQSR. 𝒟 ℒ D 4,× is a very expressive description logic. It combines the high scalability and efficiency of rule languages such as the SemanticWeb Rule Language (SWRL) with the expressivity of description logics. In fact, among other features, it supports Boolean operations on concepts and roles, role constructs such as the product of concepts and role chains on the left-hand side of inclusion axioms, role properties such as transitivity, symmetry, reflexivity, and irreflexivity, and data types. We further provide a KE-tableau-based procedure that allows one to reason on the main TBox and ABox reasoning tasks for the description logic 𝒟 ℒ D 4,× . Our algorithm is based on a variant of the KE-tableau system for sets of universally quantified clauses, where the KE-elimination rule is generalized in such a way as to incorporate the γ-rule. The novel system, called KEγ-tableau, turns out to be an improvement of the system introduced in [1] and of standard first-order KE-tableaux [2]. Suitable benchmark test sets executed on C++ implementations of the three mentioned systems show that in several cases the performances of the KEγ-tableau-based reasoner are up to about 400% better than the ones of the other two systems.

scholarly journals Comparison between Online and Offline Price of Tobacco Products Using Novel Datasets

2018 ◽  
Vol 15 (10) ◽  
pp. 2282 ◽  
Author(s):  
Magdalena Opazo Breton ◽  
John Britton ◽  
Yue Huang ◽  
Ilze Bogdanovica
Keyword(s):  
Regression Analysis ◽  
Real Time ◽  
Control Measure ◽  
Data Sources ◽  
Tobacco Products ◽  
Product Range ◽  
Daily Data ◽  
Wide Range ◽  
Commercial Sources ◽  
Price Differences

Price of tobacco products has traditionally been relevant both for the industry, to respond to policy changes, and for governments, as an effective tobacco control measure. However, monitoring prices across a wide range of brands and brand variants requires access to expensive commercial sales databases. This study aims to investigate the comparability of average tobacco prices from two commercial sources and an in-house monitoring database which provides daily data in real time at minimal cost. We used descriptive and regression analysis to compare the monthly average numbers of brands, brand variants, products and prices of cigarettes and hand-rolling tobacco using commercial data from Nielsen Scantrack and Kantar Worldpanel, and an online price database (OPD) created in Nottingham, for the period from May 2013 to February 2017. There were marked differences in the number of products tracked in the three data sources. Nielsen was the most comprehensive and Kantar Worldpanel the least. Though average prices were very similar between the three datasets, Nottingham OPD prices were the highest and Kantar Worldpanel the lowest. However, regression analysis demonstrated that after adjustment for differences in product range, price differences between the datasets were very small. After allowing for differences in product range these data sources offer representative prices for application in price research. Online price tracking offers an inexpensive and near real-time alternative to the commercial datasets.

scholarly journals KEMANDIRIAN FINANSIAL LEMBAGA PENDIDIKAN MELALUI ENTREPRENEURSHIP DAN PARTNERSHIP

2016 ◽  
Vol 7 (1) ◽  
pp. 1197
Author(s):  
Ahmad Romadhon
Keyword(s):  
Participant Observation ◽  
Educational Institution ◽  
Boarding School ◽  
Research Data ◽  
Data Sources ◽  
Case Method ◽  
Financial Independence ◽  
Wide Range ◽  
Study Case ◽  
Depth Interviews

The objective of this research was to understand comprehensively the Financial Independent in Organization of Education through Entrepreneurship and partnership. it was a qualitative research with study case method conducted in Al Ashriyyah Nurul Iman Islamic Boarding School, Parung-Bogor. In this research data collecting with triangulation technique, Overall the researchers use participant observation, in-depth interviews, and documentation for the same data sources simultaneously. As a private educational institution, Al Ashriyyah Nurul Iman Foundation since its inception independently manage and develop the foundation to establish a wide range of entrepreneurial and cooperation with various institutions and circles. Financial independence has always strived through two things very well. Develop without relying on finance from other parties is a priority for YANIIBS, so that entrepreneurship and partnerships with these institutions become more developed and advanced

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