537 research outputs found
Dominance Measuring Approach using Stochastic Weights
In this paper we propose an approach to obtain a ranking of alternatives in multicriteria decision-making problems when there is imprecision concerning the alternative performances, component utility functions and weights. We assume decision maker's preferences are represented by an additive multi-attribute utility function, in which weights are modeled by independent normal variables, the performance in each attribute for each alternative is an interval value and classes of utility functions are available for each attribute. The approach we propose is based on dominance measures, which are computed in a similar way that when the imprecision concerning weights is modeled by uniform distributions or by an ordinal relation. In this paper we will show how the approach can be applied when the imprecision concerning weights are represented by normal distributions. Extensions to other distributions, such as truncated normal or beta, can be feasible using Monte Carlo simulation techniques
La producciĂłn de artĂculos cientĂficos como competencia a desarrollar en las nuevas generaciones acadĂ©micas en Colombia
El concepto actual de las competencias acadĂ©micas, implica la importancia de saber desempeñarse en un medio y dentro de un contexto establecido para los docentes y alumnos de cada proceso acadĂ©mico en nuestra geografĂa, lo mismo que en diversidad de paĂses1. Es notoria a nivel de las instituciones acadĂ©micas en educaciĂłn superior, la ausencia marcada y formal de una competencia en lecto-escritura por parte de los principales actores, lo que implica una sensaciĂłn de atraso en la creaciĂłn de artĂculos cientĂficos, resĂşmenes, monografĂas y revisiones sistemáticas de la literatura cientĂfica en Colombia y en muchos otros paĂses2, 3
Ranking Alternatives on the Basis of a Dominance Intensity Measure
The additive multi-attribute utility model is widely used within MultiAttribute Utility Theory (MAUT), demanding all the information describing the decision-making situation. However, these information requirements can obviously be far too strict in many practical situations. Consequently, incomplete information about input parameters has been incorporated into the decisionmaking process. We propose an approach based on a dominance intensity measure to deal with such situations. The approach is based on the dominance values between pairs of alternatives that can be computed by linear programming. These dominance values are transformed into dominance intensities from which a dominance intensity measure is derived. It is used to analyze the robustness of a ranking of technologies for the disposition of surplus weapons-grade plutonium by the Department of Energy in the USA, and compared with other dominance measuring methods
Ergonomic factors that cause the presence of pain muscle in students of dentistry
Objective: To identify the ergonomic factors and the presence of muscular pain in dental students of VIII, IX, X semesters presently practicing at the clinics of the College of Dentistry of university of Cartagena, Colombia, South America. Materials and methods: This is a descriptive study carried out in dental students of the VIII, IX, and X semesters which were undergoing clinical practice at the College of Dentistry of University of Cartagena. A convenience sample of 83 students who met the inclusion criteria was taken and those who agreed to participate signed an informed consent. Data collection was obtained by means of a structured questionnaire for ergonomic factors and the presence of pain was identified palpating the muscles object of the study by a physical therapist. The variables evaluated were: presence of pain, affected muscles, affected zones, gender, postures and work environment. Results: The adoption of inadequate postures such as exaggerated flexions or cervical torsions could generate a higher frequency of muscular pain in dental students. The approximating muscle of the thumb showed 11% frequency of pain. The presence of muscular pain was higher for the female group participating in this study. Conclusions: Dentists are prone, since the beginning of their clinical practice as students, to lesions of the skeletal muscle system due to the clinical exercise of the profession, being the most common, muscle pain in the back, neck, shoulders and hands. This would imply initiating an occupational health program promoting healthy lifestyles in their academic environment and their future professional life, at the beginning of their clinical practice in dental school
Multiple hyperodontia: report of a case with 17 supernumerary teeth with non syndromic association
Supernumerary teeth or hyperodontia is an infrequent developmental alteration that appears in any area of the dental arches and can affect any dental organ. Multiple hyperodontia can be associated with several syndromes such as Gardner’s, cleidocranial dysplasia, tricho-rhino phalangic syndrome or in patients with cleft lip and palate.However, it can be present in patients without any systemic pathology. The presence of supernumerary teeth is associated with different alterations in neighboring teeth, being the most common: over retained teeth or delayed eruption, ectopic eruption, dental malposition, occlusal problems, diastemas and rotated neighboring teeth, among a series of associated pathologies.The routine use of radiographic images during examination is a valuable tool that helps make the early diagnosis of these types of abnormalities. Keeping in mind that there are different treatment options, the therapeutic modalities increase. A case of a 20 year old female patient with multiple supernumerary teeth with non syndromic association is presented. The teeth were located in the maxilla and the mandible causing a severe malocclusion
Mineral trioxide aggregate in primary teeth pulpotomy. A systematic literature review
Evidence-based dentistry is a critical evaluation, awareness of the available evidence to improve decision making about the care of individual patients and / or communities. Objective: To systematically analyze the available scientific literature on clinical and radiographic results of two materials used in pulpotomy in primary teeth: formocresol and mineral trioxide aggregate. Materials and methods: It was identified relevant publications through a search of electronic databases such as MEDLINE (Ovid) and The Cochrane Library. To be included in the review, studies had to define the material used in child patients with pulp exposure by caries or tooth-alveolar trauma. Results: Of the 21 articles obtained in the initial phase of the review, only 19 were available in full text and of these only met the requirements for inclusion 6 items, which were confronted, analyzed and discussed later. Conclusions: The clinical evidence available showed significant differences regarding the use of a material or another. In addition to the findings of clinical follow - radiographic and taking into account the potential toxicity of formocresol suggest the use of mineral trioxide aggregate pulpotomy of primary teeth
Agrandamiento gingival farmacoinducido: Serie de casos
Introduction: Gingival enlargement (GA) is a benign condition of the oral cavity that is characterized by the excessive growth of the gingiva in mass and volume. This lesion is not only caused by hereditary factors or poor oral hygiene, but also by the intake of medications, including antihypertensive, anticonvulsant and immunosuppressive drugs. Objective: To sensitize the prevention or early care in patients with pathologies that merit the use of antihypertensive and anticonvulsants in conjunction with the dentist, to treat or avoid the drug-induced gingival enlargement (DIGE). Materials and methods: A series of clinical cases of patients with gingival enlargement by various drugs are reported, including Phenytoin, Amlodipine and Nifedipine. Periodontal and gingivectomy hygienic phase measures were applied to obtain better effects. Results: Satisfactory results were obtained with a considerable decrease in DIGE. Conclusions: The integral management is important in conjunction with the treating physician to follow up the drug that can be generating gingival enlargement. It is necessary to employ an initial approach with strategies of periodontal hygiene, and in severe cases and, as last resort, the periodontal surgery with gingivectomy and gingivoplasty
Elements of the anthropological theory of didactics in the selection of contents in a course of fluid mechanics in engineering, a case study in Spanish universities.
The Anthropological Theory of Didactics has been applied to the field of didactics of mathematics with remarkable success. Fluid Mechanics is a discipline with a strong mathematical background, where mathematics is used for modeling the continuous nature. In addition, the Fluid Mechanics concepts are essential for the future engineer or scientist. For this reason, it is worth thinking whether the content that developed in engineering schools or science faculties are those demanded by the future professionals. The analysis has been done within the context of a case study framed in the Spanish noosphere, more particularly Universities and Companies. In this direction, the objective of this article is to know the institutional distance between the University and society as a demander of technologies based on Fluid Mechanics. To this end, the methodology based on the issuance of a questionnaire to experts focused on aspects such as present and emerging content associated with the Fluid Mechanics of an engineering degree is used. Note that the number of experts selected is reduced so as to consider the study as a sourcing for introducing expert thoughts on the fluid mechanics conception between university and companies. The results highlight the existence of an institutional distance between the University and the Enterprise (as a technology executor) in the conception of contents, thus establishing an area of potential improvement within the noosphere associated with fluid mechanics in Spain.post-print771 K
Elements of the Anthropological Theory of Didactics in the Selection of Contents in a Course of Fluid Mechanics in Engineering
The Anthropological Theory of Didactics has been applied to the field of didactics of mathematics with remarkable success. Fluid Mechanics is a discipline with a strong mathematical background, where mathematics is used for modeling the continuous environment. In addition, the Fluid Mechanics concepts are essential for the future engineer or scientist. For this reason, it is worth thinking whether the content that developed in engineering schools or science faculties are those demanded by the future professionals. The objective of this article is to know the institutional distance between the University and society as a demander of technologies based on Fluid Mechanics. To this end, the methodology based on the issuance of a questionnaire to experts focused on aspects such as present and emerging content associated with the Fluid Mechanics of an engineering degree is used. The results highlight the existence of an institutional distance between the University and the Enterprise (as a technology executor) in the conception of contents, thus establishing an area of potential improvement within the noosphere associated with fluid mechanics
ATOMISTIC SIMULATIONS OF HYDROGEN EMBRITTLEMENT IN PALLADIUM
Palladium hydrogen system has unique catalytic activities and up to 1:1 hydrogen adsorption capability. It is studied in the context of hydrogen embrittlement, which is a subset of stress corrosion cracking, with classical molecular dynamics techniques. Hydrogen embrittlement is a long lasting metallurgical challenge due to its intractability and unpredictability.
First, the thermomechanical properties are studied parametrically in a wide range of hydrogen concentration and temperature, serving a database for hierarchical multiscale simulations and constitutive models in mechanics. To quantitatively describe the kinetics of hydrogen segregation at crack tips, anisotropic diffusion properties are investigated under tensile/compressive loads in both elastic and plastic regions at different temperature and hydrogen concentration. Meanwhile, vacancy concentration as a function of strain is also studied in the same circumstances to quantitatively study the super abundant vacancy phenomenon and how it could initiate hydrogen embrittlement. Further, hydrogen interactions with coherent twin boundary is simulated at finite temperature. The local strength of twin boundary with hydrogen is estimated by molecular dynamics nanoindentation. At last, the heterogeneous nucleation mechanisms of defects under the influence of hydrogen content in single crystal pillars with different growth orientations are investigated to reveal the slip versus twin competition in plastic deformation. In short, a wide range of interesting topics are rigorously explored in the realm of atomistic hydrogen embrittlement
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