Modelling spatial reasoning systems with shape algebras and formal logic

1997 ◽  
Vol 11 (4) ◽  
pp. 273-285 ◽  
Author(s):  
Scott C. Chase
Keyword(s):  
Spatial Reasoning ◽  
Predicate Logic ◽  
Spatial Relations ◽  
Large Set ◽  
First Order ◽  
Reasoning Systems ◽  
Geometric Objects ◽  
Small Set ◽  
Definition Of ◽  
High Level

AbstractThe combination of the paradigms of shape algebras and predicate logic representations, used in a new method for describing designs, is presented. First-order predicate logic provides a natural, intuitive way of representing shapes and spatial relations in the development of complete computer systems for reasoning about designs. Shape algebraic formalisms have advantages over more traditional representations of geometric objects. Here we illustrate the definition of a large set of high-level design relations from a small set of simple structures and spatial relations, with examples from the domains of geographic information systems and architecture.

Logic And Prolog Database System

1989 ◽  
pp. 41-48
Author(s):  
Mohamed Othman
Keyword(s):  
Relational Database ◽  
Question Answering ◽  
Predicate Logic ◽  
Database System ◽  
Large Set ◽  
Inference System ◽  
First Order ◽  
Small Set ◽  
Representation Language ◽  
Initial Research

This paper discusses an initial research of a subfield of first order predicate logic applied to the database. Consideration has been made toward the relational database system.Here,the logic used boths as an inference system as well as a representation language. The use of logic for knowledge representation and manipulation is previously due to the work of question-answering system, which have been mainly concerned with the deductive manipulation of a small set of facts and thus require an inferential mechanism provided by logic. Similar techniques have been adopted to databases to handle large set of facts, open queries, and others. Keywords: Relational database, Programming in logic, classical interpretation, unification and queries

Computer-Aided Design Synthesis Using Syntactic Solid Modeling

1994 ◽  
Author(s):  
Vassilios E. Theodoracatos ◽  
Xiaogang Guan
Keyword(s):  
Computer Aided Design ◽  
Solid Modeling ◽  
Large Set ◽  
Complex Structures ◽  
Design Synthesis ◽  
Computer Aided ◽  
Grammar Rules ◽  
Small Set ◽  
Definition Of ◽  
Aided Design

Abstract This paper presents a new Computer-Aided Design (CAD) synthesis model which uses Plex Grammar as structural relationship descriptors and NURBS surface representation for constructing standard and non-standard solid entities. Here, the designer uses a syntactic design methodology for early topological and geometrical definition of the structure of concept alternatives resulting from the design process. This syntactic scheme provides the capability of describing a large set of complex structures by using a small set of simple entities. The recursive nature of the grammar and the hierarchical representation of the structure makes the description of complex structures simple and under the direct control of the designer. An object structure constructive tree is generated and subsequently translated into Plex Grammar production rules in order to form an Interconnection Matrix (ICM) expressing. The resulting Plex structure defined in the ICM expresses the topological information among entities which form the specific types of objects. By modifying the Plex grammar rules, various objects with different geometry and topology can easily be reconstructed. Compared to conventional solid modeling techniques, this approach provides more systematic object generation, easy manipulation and modification, control over congruity and the ability to represent sculptured shapes. Several examples of syntactic solid modeling applied in design synthesis will be presented for further usage in downstream applications.

A Logical Reconstruction of Leibniz’s Argument for His Complete Concept Conception of the Nature of Substance in Discours §8

2020 ◽  
Vol 23 (2) ◽  
pp. 447-473
Author(s):  
Ralf Busse
Keyword(s):  
Predicate Logic ◽  
Identity Of Indiscernibles ◽  
First Order ◽  
Real Definition ◽  
Concept Definition ◽  
Logical Reconstruction ◽  
Definition Of ◽  
Complete Concept ◽  
First Order Predicate Logic ◽  
Predication Relation

Abstract This paper develops a valid reconstruction in first-order predicate logic of Leibniz’s argument for his complete concept definition of substance in §8 of the Discours de Métaphysique. Following G. Rodriguez-Pereyra, it construes the argument as resting on two substantial premises, the “merely verbal” Aristotelian definition and Leibniz’s concept containment theory of truth, and it understands the resulting “real” definition as saying not that an entity is a substance iff its complete concept contains every predicate of that entity, but iff its complete concept contains every predicate of any subject to which that concept is truly attributable. An account is suggested of why Leibniz criticises the Aristotelian definition as merely nominal and how he takes his own definition to overcome this shortcoming: while on the Aristotelian basis the predication relation could generate endless chains, so that substances as endpoints of predication would be impossible, Leibniz’s definition reveals lowest species as such endpoints, which he therefore identifies with individual substances. Since duplicate lowest species make no sense, the Identity of Indiscernibles for substances follows. The reading suggests a Platonist interpretation according to which substances do not so much have but are individual essences, natures or forms.

scholarly journals Pretopologies and completeness proofs

1995 ◽  
Vol 60 (3) ◽  
pp. 861-878 ◽  
Author(s):  
Giovanni Sambin
Keyword(s):  
Classical Logic ◽  
Sequent Calculus ◽  
Predicate Logic ◽  
Linear Logic ◽  
Double Negation ◽  
Open Problems ◽  
Completeness Proof ◽  
Structural Rules ◽  
First Order ◽  
Definition Of

Pretopologies were introduced in [S], and there shown to give a complete semantics for a propositional sequent calculus BL, here called basic linear logic, as well as for its extensions by structural rules, ex falso quodlibet or double negation. Immediately after Logic Colloquium '88, a conversation with Per Martin-Löf helped me to see how the pretopology semantics should be extended to predicate logic; the result now is a simple and fully constructive completeness proof for first order BL and virtually all its extensions, including the usual, or structured, intuitionistic and classical logic. Such a proof clearly illustrates the fact that stronger set-theoretic principles and classical metalogic are necessary only when completeness is sought with respect to a special class of models, such as the usual two-valued models.To make the paper self-contained, I briefly review in §1 the definition of pretopologies; §2 deals with syntax and §3 with semantics. The completeness proof in §4, though similar in structure, is sensibly simpler than that in [S], and this is why it is given in detail. In §5 it is shown how little is needed to obtain completeness for extensions of BL in the same language. Finally, in §6 connections with proofs with respect to more traditional semantics are briefly investigated, and some open problems are put forward.

UNIFICATION IN SUPERINTUITIONISTIC PREDICATE LOGICS AND ITS APPLICATIONS

2018 ◽  
Vol 12 (1) ◽  
pp. 37-61 ◽  
Author(s):  
WOJCIECH DZIK ◽  
PIOTR WOJTYLAK
Keyword(s):  
Propositional Logic ◽  
Predicate Logic ◽  
Order Logic ◽  
Existential Quantifier ◽  
First Order ◽  
Admissible Rules ◽  
Structural Completeness ◽  
Individual Variables ◽  
Definition Of ◽  
Finitely Presented

AbstractWe introduce unification in first-order logic. In propositional logic, unification was introduced by S. Ghilardi, see Ghilardi (1997, 1999, 2000). He successfully applied it in solving systematically the problem of admissibility of inference rules in intuitionistic and transitive modal propositional logics. Here we focus on superintuitionistic predicate logics and apply unification to some old and new problems: definability of disjunction and existential quantifier, disjunction and existential quantifier under implication, admissible rules, a basis for the passive rules, (almost) structural completeness, etc. For this aim we apply modified specific notions, introduced in propositional logic by Ghilardi, such as projective formulas, projective unifiers, etc.Unification in predicate logic seems to be harder than in the propositional case. Any definition of the key concept of substitution for predicate variables must take care of individual variables. We allow adding new free individual variables by substitutions (contrary to Pogorzelski & Prucnal (1975)). Moreover, since predicate logic is not as close to algebra as propositional logic, direct application of useful algebraic notions of finitely presented algebras, projective algebras, etc., is not possible.

Looking at Faces: First-Order and Second-Order Features as Determinants of Facial Appearance

Perception ◽  
1988 ◽  
Vol 17 (1) ◽  
pp. 43-63 ◽  
Author(s):  
Gillian Rhodes
Keyword(s):  
Mental Representations ◽  
Three Dimensional ◽  
Spatial Relations ◽  
Second Order ◽  
Large Set ◽  
First Order ◽  
Feature Parameters ◽  
Similarity Judgments ◽  
Facial Similarity ◽  
Unfamiliar Faces

The encoding and relative importance of first-order (discrete) and second-order (configural) features in mental representations of unfamiliar faces have been investigated. Nonmetric multidimensional scaling (KYST) was carried out on similarity judgments of forty-one photographs of faces (homogeneous with respect to sex, race, facial expression, and, to a lesser extent, age). A large set of ratings, measurements, and ratios of measurements of the faces was regressed against the three-dimensional KYST solution in order to determine the first-order and second-order features used to judge similarity. Parameters characterizing both first-order and second-order features emerged as important determinants of facial similarity. First-order feature parameters characterizing the appearance of the eyes, eyebrows, and mouth, and second-order feature parameters characterizing the position of the eyes, spatial relations between the internal features, and chin shape correlated with the dimensions of the KYST solution. There was little difference in the extent to which first-order and second-order features were encoded. Two higher-level parameters, age and weight, were also used to judge similarity. The implications of these results for mental representations of faces are discussed.

scholarly journals Obtención de inferencias en documentos de pasantía descritos a nivel ontológico

Respuestas ◽  
2015 ◽  
Vol 20 (2) ◽  
pp. 119
Author(s):  
Germán Alejandro Pinilla-García ◽  
Julio Barón-Velandia
Keyword(s):  
Knowledge Base ◽  
Predicate Logic ◽  
First Order ◽  
Vast Amount ◽  
Implicit Information ◽  
Search Processes ◽  
Ontological Model ◽  
High Level ◽  
Computational Representation

ResumenAntecedentes: El número de usuarios que en la actualidad se apropia de prácticas de consulta utilizando sistemas documentales crece de manera significativa, sin embargo el uso convencional de procesos de búsqueda de manera textual o sintáctica, produce una extensa cantidad de resultados con bajo nivel de pertinencia, obligando al usuario a emplear un gran número de horas para acceder a los resultados proporcionados y determinar aquellos que presentan un alto grado de correspondencia con su área de interés. Objetivo: El objetivo fundamental de este trabajo es obtener un conjunto de inferencias mediante la lógica de predicados, a partir de un modelo ontológico de trabajos de grado en modalidad pasantía, las cuales permitan obtener información implícita a partir de las descripciones semánticas que representan a cada uno de los documentos referenciados. Metodología: El modelo ontológico se obtuvo consultando las normas y disposiciones acerca de pasantías, estableciendo los conceptos del dominio y las correspondientes relaciones entre conceptos; la representación computacional del modelo se realizó en lenguaje OWL y mediante lógica de predicados de primer orden, se establecieron las sentencias que permiten la realización de inferencias para obtener información implícita contenida en la base de conocimiento. Resultados: Entre las inferencias más significativas que se obtuvieron están: la tipificación de documentos relacionados con un tema de interés y la identificación de docentes por áreas de experticia. Conclusión: La aplicación de la lógica de predicados a esta modalidad de trabajos de grado permite realizar inferencias de manera dinámica sobre el contenido representado a nivel ontológico y puede utilizarse para complementar la información descrita explícitamente en el modelo, con respecto a temáticas y áreas de experticia de los docentes, independientemente de la ubicación de los repositorios de documentos. Las sentencias utilizadas pueden ser aplicadas a otras modalidades de grado como investigación y monografía.Abstract Background: The number of users that currently appropriates query practices using document systems has grown significantly, however, the conventional use of textual or syntactical search processes produces a vast amount of low-relevant results, forcing the user to employ a large number of hours to access the results provided and to determine those with a high level of correspondence with their field of interest. Objective: The main objective of this work was to obtain a set of inferences through predicate logic, from an internship documents ontological model, which allow to obtain implicit information from semantic descriptions representing each one of the referenced documents. Methods: The ontological model was obtained by consulting standards and provisions about internships, setting the domain concepts and the corresponding relations between concepts; the model computational representation was developed with OWL language and first-order predicate logic were used to establish the sentences that allow making inferences, to get implicit information in the knowledge base. Results: Among the most significant inferences that were obtained are: the classification of documents related to a topic of interest and the identification of teachers by areas of expertise. Conclusion: The application of predicate logic to internship documents allows to dynamically make inferences about the content represented at ontological level and can be used to complement the explicitly described information in the model, regarding issues and areas of expertise of the teachers, regardless of the location of document repositories. The statements used can be applied to other types of degree as research and monography.Palabras clave: Inferencia, lógica de predicados, ontología, pasantía.

Europe

2020 ◽  
pp. 649-666
Author(s):  
Andrea Renda
Keyword(s):  
Artificial Intelligence ◽  
Digital Technology ◽  
Policy Framework ◽  
Expert Group ◽  
Ethical Guidelines ◽  
Ethical Implications ◽  
Strong Focus ◽  
Ethics Guidelines ◽  
Definition Of ◽  
High Level

This chapter assesses Europe’s efforts in developing a full-fledged strategy on the human and ethical implications of artificial intelligence (AI). The strong focus on ethics in the European Union’s AI strategy should be seen in the context of an overall strategy that aims at protecting citizens and civil society from abuses of digital technology but also as part of a competitiveness-oriented strategy aimed at raising the standards for access to Europe’s wealthy Single Market. In this context, one of the most peculiar steps in the European Union’s strategy was the creation of an independent High-Level Expert Group on AI (AI HLEG), accompanied by the launch of an AI Alliance, which quickly attracted several hundred participants. The AI HLEG, a multistakeholder group including fifty-two experts, was tasked with the definition of Ethics Guidelines as well as with the formulation of “Policy and Investment Recommendations.” With the advice of the AI HLEG, the European Commission put forward ethical guidelines for Trustworthy AI—which are now paving the way for a comprehensive, risk-based policy framework.

scholarly journals Shape Sensing of a Complex Aeronautical Structure with Inverse Finite Element Method

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1388
Author(s):  
Daniele Oboe ◽  
Luca Colombo ◽  
Claudio Sbarufatti ◽  
Marco Giglio
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Strain Field ◽  
Element Analysis ◽  
Inverse Finite Element Method ◽  
Shape Sensing ◽  
Definition Of ◽  
High Level ◽  
Element Method

The inverse Finite Element Method (iFEM) is receiving more attention for shape sensing due to its independence from the material properties and the external load. However, a proper definition of the model geometry with its boundary conditions is required, together with the acquisition of the structure’s strain field with optimized sensor networks. The iFEM model definition is not trivial in the case of complex structures, in particular, if sensors are not applied on the whole structure allowing just a partial definition of the input strain field. To overcome this issue, this research proposes a simplified iFEM model in which the geometrical complexity is reduced and boundary conditions are tuned with the superimposition of the effects to behave as the real structure. The procedure is assessed for a complex aeronautical structure, where the reference displacement field is first computed in a numerical framework with input strains coming from a direct finite element analysis, confirming the effectiveness of the iFEM based on a simplified geometry. Finally, the model is fed with experimentally acquired strain measurements and the performance of the method is assessed in presence of a high level of uncertainty.

scholarly journals A fatal toxic shock-like syndrome post COVID-19 infection in a child

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Houda Ajmi ◽  
Wissem Besghaier ◽  
Wafa Kallala ◽  
Abdelhalim Trabelsi ◽  
Saoussan Abroug
Keyword(s):  
Ejection Fraction ◽  
Pediatric Intensive Care ◽  
Fresh Frozen Plasma ◽  
Multiple Organ ◽  
Clinical Feature ◽  
Fresh Frozen ◽  
Life Threatening ◽  
High Doses ◽  
Definition Of ◽  
High Level

Abstract Background Children affected by Coronavirus disease 2019 (COVID-19) showed various manifestations. Some of them were severe cases presenting with multi-system inflammatory syndrome (MIS-C) causing multiple organ dysfunction. Case presentation We report the case of a 12-year-old girl with recent COVID-19 infection who presented with persistent fever, abdominal pain and other symptoms that meet the definition of MIS-C. She had lymphopenia and a high level of inflammatory markers. She was admitted to pediatric intensive care unit since she rapidly developed refractory catecholamine-resistant shock with multiple organ failure. Echocardiography showed a small pericardial effusion with a normal ejection fraction (Ejection Fraction = 60%) and no valvular or coronary lesions. The child showed no signs of improvement even after receiving intravenous immunoglobulin, fresh frozen plasma, high doses of Vasopressors and corticosteroid. His outcome was fatal. Conclusion Pediatric patients affected by the new COVID-19 related syndrome may show severe life-threatening conditions similar to Kawasaki disease shock syndrome. Hypotension in these patients results from heart failure and the decreased cardiac output. We report a new severe clinical feature of SARS-CoV-2 infection in children in whom hypotension was the result of refractory vasoplegia.

Sign in / Sign up

Export Citation Format

Share Document