Geometric Tools Dedicated to the Adaption and Idealization of 3D Models for F.E. Analysis

1997 ◽  
Author(s):  
Philippe Véron ◽  
Jean-Claude Léon
Keyword(s):  
Geometric Model ◽  
A Priori ◽  
3D Models ◽  
Geometric Configuration ◽  
A Posteriori ◽  
Complex Shapes ◽  
Mesh Adaption ◽  
Node Removal ◽  
Candidate Node

Abstract Geometric adaptions and idealizations of 3D models for F.E. analysis purposes are often necessary. Geometric tools are proposed to partly automatize shape adaptions and idealizations of polyhedral models. The simplification process is monitored using error zones attached to each polyhedron vertex. Their dimension may be either set by the designer, by an a posteriori or by an a priori mechanical mesh adaption process. Such an approach allows to process various polyhedral models characterized by general and complex shapes. A classification of nodes and edges is carried out to apply a specific node removal operator in accordance with the local geometric configuration around a node. Moreover, specific criteria are used to select the best candidate node for removal. Also, additional operators have been developed to process particular configurations and produce the final idealized model. During this geometric idealization process, the shape restitution of the part is maintained through an inheritance process of the error zones. Topological changes as well as the coherence of the non-manifold geometric model are managed using specific criteria to produce acceptable approximations of idealized geometries.

Descartes’s Philosophical Theology

2019 ◽  
pp. 208-225
Author(s):  
Igor Agostini
Keyword(s):  
A Priori ◽  
Philosophical Theology ◽  
Strict Sense ◽  
A Posteriori ◽  
The Third ◽  
Definition Of ◽  
True Definition

In this chapter I argue the following thesis: 1) Descartes’s Meditations never formulate the problem of God’s existence as it is required by the precepts of order; in particular, the only problem of existence posed by Descartes after the classification of thoughts in the Third Meditation does not concern God directly, but generally aliqua res. 2) Though Descartes qualifies the two proofs of the Third Meditation as a posteriori, they cannot be considered as homologous in their structure to the traditional a posteriori proofs: they both—and the second in particular—contain components that are truly a priori. 3) The proof of the Fifth Meditation, as it starts from the true definition of God and God’s essence, does not constitute a quoadnos version of the a priori demonstration belonging to mathematics, but is, in a strict sense, a potissima demonstration that is at least as evident as those of mathematics.

Towards a structural-functional classification of fynbos: a comparison of methods

Bothalia ◽  
1979 ◽  
Vol 12 (4) ◽  
pp. 723-729 ◽  
Author(s):  
P. Linder ◽  
B. M. Campbell
Keyword(s):  
Numerical Methods ◽  
A Priori ◽  
Large Data ◽  
Large Data Sets ◽  
Data Sets ◽  
A Posteriori ◽  
Computer Based ◽  
Single Method ◽  
Working Hypotheses

The need for a classification of the vegetation of the fynbos region is stressed. In the present work we have evaluated some structural-functional approaches that could be used to classify and describe fynbos.  A priori and  a posteriori approaches to classification are reviewed. The a posteriori approach appears to be superior.Test data derived from 21 plots from a range of fynbos types were used to test some methods of collecting and analysing structural-functional information for an  a posteriori  classification. With respect to data collection, no single method was superior. However, a major improvement on our methodology would be possible if the growth-form system used were to be extended. The classifications that were erected were produced by means of computer-based numerical methods. These methods are essential if large data sets are to be analysed. However, the structural-functional classifications produced by numerical methods should only be regarded as working hypotheses; refinement of the classifications should proceed by intuitive methods. We feel that the a posteriori approach, even though it has its problems, will provide a suitable methodology for an ecologically meaningful classification of fynbos vegetation.

SYSTEMATIC APPROACH TO THE COMPOSITION OF CONTROL FUNCTIONS IN THE INFORMATION SECURITY SYSTEMS

2018 ◽  
pp. 71-80
Author(s):  
Georgiy Aleksandrovich Popov ◽  
Ekaterina Aleksandrovna Popova
Keyword(s):  
Information Security ◽  
Systematic Approach ◽  
A Priori ◽  
A Posteriori ◽  
Distribution Problem ◽  
Security Systems ◽  
Control Functions ◽  
Management Functions ◽  
Efficient Realization

The paper highlights the procedure of forming the composition of management functions in the information security systems, which is based on a systematic approach. The stages of the life cycle of the threat and the realization pattern of the function have been chosen as indicators of the classification of information security functions - a priori (before the threat was manifested, i.e. responses to threats are taken on a scheduled basis), or a posteriori (after the threat had been realized, i.e. responses to threats are taken in real time). Two classes of functions are distinguished: functions ensuring the information security and functions controlling mechanisms for ensuring the information security. The research of all the dedicated functions resulted in forming a set of 22 functions. For the information security functions there were built two diagrams of possible outcomes, such as successful protection of information, breaking the security system, or its damage in the course of the function realization. The procedure of finding probabilities for the outcomes using the diagrams has been described. The efficient realization of the functions offered is more dependent on the way the functions are used and organized in the framework of an integral technology of providing information security and on the amount of the resource and financial support of these functions. Building the diagram of the outcomes helps to formalize and solve the tasks of distribution of the resources needed for increasing the level of information security. As an example there have been presented two statements of the distribution problem for improving the efficiency of realization of each of the above functions.

A priori/a posteriori

2017 ◽  
Author(s):  
Heinrich Schepers ◽  
Giorgio Tonelli ◽  
Rudolf Eisler
Keyword(s):  
A Priori ◽  
A Posteriori

A Critique of Modernist Synthesis in Islamic Thought

1994 ◽  
Vol 11 (4) ◽  
pp. 475-503
Author(s):  
Masudul Alum Choudhury
Keyword(s):  
Scientific Inquiry ◽  
A Priori ◽  
Scientific Investigation ◽  
Muslim World ◽  
A Posteriori ◽  
Islamic Thought ◽  
And Behavior ◽  
Muslim Scholars

Is it the realm of theoretical constructs or positive applications thatdefines the essence of scientific inquiry? Is there unison between thenormative and the positive, between the inductive and deductivecontents, between perception and reality, between the micro- andmacro-phenomena of reality as technically understood? In short, isthere a possibility for unification of knowledge in modernist epistemologicalcomprehension? Is knowledge perceived in conceptionand application as systemic dichotomy between the purely epistemic(in the metaphysically a priori sense) and the purely ontic (in thepurely positivistically a posteriori sense) at all a reflection of reality?Is knowledge possible in such a dichotomy or plurality?Answers to these foundational questions are primal in order tounderstand a critique of modernist synthesis in Islamic thought thathas been raging among Muslim scholars for some time now. Theconsequences emanating from the modernist approach underlie muchof the nature of development in methodology, thinking, institutions,and behavior in the Muslim world throughout its history. They arefound to pervade more intensively, I will argue here, as the consequenceof a taqlid of modernism among Islamic thinkers. I will thenargue that this debility has arisen not because of a comparativemodem scientific investigation, but due to a failure to fathom theuniqueness of a truly Qur'anic epistemological inquiry in the understandingof the nature of the Islamic socioscientific worldview ...

Qualifier la qualité des données localisées numériques des réseaux d’eau et d’assainissement

2019 ◽  
Vol 11 ◽  
pp. 51-64
Author(s):  
M. LE MOAL
Keyword(s):  
A Priori ◽  
A Posteriori ◽  
Systèmes D’Information Géographique ◽  
Systèmes D’Information

Les systèmes d’information géographique (SIG) sont devenus incontournables dans la gestion des réseaux d’eau et d’assainissement et leur efficacité repose en très grande partie sur la qualité des données exploitées. Parallèlement, les évolutions réglementaires et les pratiques des utilisateurs augmentant notamment les échanges d’informations renforcent le rôle central des données et de leur qualité. Si la plupart des solutions SIG du marché disposent de fonctions dédiées à la qualification de la qualité des données, elles procèdent de la traduction préalable de spécifications des données en règles informatiques avant de procéder aux tests qualitatifs. Cette approche chronophage requiert des compétences métier. Pour éviter ces contraintes, Axes Conseil a élaboré un procédé de contrôle des données SIG rapide et accessible à des acteurs métier de l’eau et de l’assainissement. Plutôt qu’une lourde approche de modélisation a priori, le principe est de générer un ensemble d’indicateurs explicites facilement exploitables a posteriori par les acteurs du métier. Cette approche offre une grande souplesse d’analyse et ne nécessite pas de compétences informatiques avancées.

Kant’s ‘Transcendental Deduction’

2018 ◽  
Author(s):  
Barry Stroud
Keyword(s):  
A Priori ◽  
Human Mind ◽  
Critical Assessment ◽  
Structural Description ◽  
A Posteriori ◽  
Human Knowledge ◽  
Transcendental Deduction ◽  
The World ◽  
Empirical Realism

This chapter presents a straightforward structural description of Immanuel Kant’s conception of what the transcendental deduction is supposed to do, and how it is supposed to do it. The ‘deduction’ Kant thinks is needed for understanding the human mind would establish and explain our ‘right’ or ‘entitlement’ to something we seem to possess and employ in ‘the highly complicated web of human knowledge’. This is: experience, concepts, and principles. The chapter explains the point and strategy of the ‘deduction’ as Kant understands it, as well as the demanding conditions of its success, without entering into complexities of interpretation or critical assessment of the degree of success actually achieved. It also analyses Kant’s arguments regarding a priori concepts as well as a posteriori knowledge of the world around us, along with his claim that our position in the world must be understood as ‘empirical realism’.

Positive Psychology’s A Priori Problem

2017 ◽  
Vol 58 (3) ◽  
pp. 313-342 ◽  
Author(s):  
Barbara S. Held
Keyword(s):  
Conceptual Framework ◽  
A Priori ◽  
A Posteriori ◽  
Negative Numbers ◽  
Psychological States ◽  
Psychological Reality ◽  
Negative Results ◽  
Optimal Functioning ◽  
Conceptual Muddles ◽  
Negative Phenomena

The positive/negative distinction works well in many fields—for example, in mathematics negative numbers hold their own, and in medical pathology negative results are usually celebrated. But in positive psychology negativity should be replaced with positivity for flourishing/optimal functioning to occur. That the designation of the psychological states and processes deemed positive (good/desirable) and negative (bad/undesirable) is made a priori, independent of circumstantial particularity, both intrapersonal and interpersonal, does not seem to bother positive psychologists. But it should, as it results in conceptual muddles and dead ends that cannot be solved within their conceptual framework of positivity and negativity. Especially problematic is an ambiguity I find in positive psychologists’ a priori and a posteriori understandings of positivity and negativity, an ambiguity about constitutive and causal relations that pervades their science and the conclusions drawn from it. By eliminating their a priori dichotomy of positivity and negativity, positive psychologists might well find themselves in a better position to put back together the psychological reality that they have fractured in their ontologically dubious move of carving up psychological reality a priori into positive and negative phenomena. They then might find themselves better placed to “broaden and build” their own science of flourishing.

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