Search results for "computer program"

IMPROVEMENTS IN THE SYSTEMS-BASED MODELS GENERATOR SIGEM

1994

Program generators, for us, are computer programs that produce other computer programs. SIGEM is an expert system program generator that can help in the modeling process of real systems. It is associated with a methodology well adapted to modeling practice. In this paper, we present and compare this methodology with other similar ones. Static models (databases), dynamic models, rule-based expert systems, literal and/or numerical variables, probabilistic uncertainty in data and in functions, dimensioned variables, discrete event simulation, and other related problems can be treated with this methodology. We suggest a systems modeling methodology and a programming tool to increase generality …

Time Dependent Deterioration of the X-Ray Dental Diagnostic Equipment

2013

Modern dental X-ray examinations are essential for diagnosis. The goal of this paper is to demonstrate time dependent behavior of dose providing parameters, which help to determine equipment’s age effects on the x-ray machine parameters. Also the comparisons between two different dental X-ray generator equipment types half-period and high frequency was made.

On the generator problem

1990

DNASE1L3 Deficiency, New Phenotypes and Evidence for a Transient Type I Interferon Signaling

2021

Introduction: Deoxyribonuclease 1 like 3 (DNASE1L3) is a secreted enzyme that has been shown to digest the extracellular chromatin derived from apoptotic bodies, and DNASE1L3 pathogenic variants have been associated to a lupus phenotype. It is unclear whether interferon signaling is sustained in DNASE1L3 deficiency in humans. Objectives: Here, we report on four patients with pathogenic variations in DNASE1L3, including 2 previously undescribed causal variants, and expand the phenotype from SLE to vasculitis with gut involvement. To explore whether or not the interferon cascade was strongly and sustainably induced, Interferon stimulated genes (ISGs) expression was assessed for each patient. …

SYSTEMS DECOMPOSITION AND COUPLING

1993

In order to handle efficiently complex models of real systems, it is a convenient practice to decompose them into subsystems that are validated independently. The next step would be joining the subsystems into a global system and performing a new global validation. A formalization of this process is performed as a consequence of practical experience with a model generator expert system based on general systems theory.

Application of an innovative alignment optimisation method to a cross-cultural mean comparison of teacher self-efficacy: A cross-country study

2021

Teacher self-efficacy is a crucial personal characteristic that is important not only for teachers’ well-being but also for the overall teaching and learning. However, the difficulty to ascertain scalar invariance in the measurement of the construct has beset previous attempts of cross-cultural comparisons. This study implements an alignment optimisation method to compare and rank mean teacher self-efficacy of over 150,000 teachers across 48 countries and economies that participated in the Teaching and Learning International Survey (TALIS) that was conducted 2018. The findings show that Columbia, Portugal, United Arab Emirates, Hungary, and South Africa have teachers with the highest mean s…

Risk assessment of component failure modes and human errors using a new FMECA approach: application in the safety analysis of HDR brachytherapy

2014

Failure mode, effects and criticality analysis (FMECA) is a safety technique extensively used in many different industrial fields to identify and prevent potential failures. In the application of traditional FMECA, the risk priority number (RPN) is determined to rank the failure modes; however, the method has been criticised for having several weaknesses. Moreover, it is unable to adequately deal with human errors or negligence. In this paper, a new versatile fuzzy rule-based assessment model is proposed to evaluate the RPN index to rank both component failure and human error. The proposed methodology is applied to potential radiological over-exposure of patients during high-dose-rate brach…

Reference density trends in the major disciplines

2018

Abstract The aim of this study was to determine whether different areas of knowledge presented different behaviour with regard to the number of references cited per journal document or if, conversely, they shared the same reference density practices. Bibliometric and bibliographic data were collected from 27,141 journals (indexed between 2001 and 2015 in the SCImago Journal & Country Rank (SJR)) and the growth rates in reference density and number of documents and journals in each category were calculated at different levels of aggregation. Our analysis identified that (a) mean reference density values in some Social Sciences and Arts and Humanities categories were equal to or higher than t…

A PHENOMENOLOGICAL OPERATOR DESCRIPTION OF INTERACTIONS BETWEEN POPULATIONS WITH APPLICATIONS TO MIGRATION

2013

We adopt an operatorial method based on the so-called creation, annihilation and number operators in the description of different systems in which two populations interact and move in a two-dimensional region. In particular, we discuss diffusion processes modeled by a quadratic hamiltonian. This general procedure will be adopted, in particular, in the description of migration phenomena. With respect to our previous analogous results, we use here fermionic operators since they automatically implement an upper bound for the population densities.

Stability of radial symmetry for a Monge-Ampère overdetermined problem

2008

Recently the symmetry of solutions to overdetermined problems has been established for the class of Hessian operators, including the Monge-Ampère operator. In this paper we prove that the radial symmetry of the domain and of the solution to an overdetermined Dirichlet problem for the Monge-Ampère equation is stable under suitable perturbations of the data. © 2008 Fondazione Annali di Matematica Pura ed Applicata and Springer-Verlag.