Acercamiento histórico epistemológico de la optimización

El discurso escolar del contenido de programación lineal, en los establecimientos educacionales chilenos, se ha convertido en un proceso mecánico y sin sentido para el estudiante. Para revertir esta mirada, se intenta dar respuesta a la siguiente interrogante ¿Cuáles son los significados reales que emergen y dan fuerza a la programación lineal? Se evidenciará el estudio del rol actual de la programación lineal y los procesos históricos de su surgimiento, con el fin de identificar aquellos factores que le dan fuerza a su desarrollo y construcción

Value Chain: From iDMU to Shopfloor Documentation of Aeronautical Assemblies

Competition in the aerospace manufacturing companies has led them to continuously improve the efficiency of their processes from the conceptual phase to the start of production and during operation phase, providing services to clients. PLM (Product Lifecycle Management) is an end-to-end business solution which aims to provide an environment of information about the product and related processes available to the whole enterprise throughout the product’s lifecycle. Airbus designs and industrializes aircrafts using Concurrent Engineering methods since decades. The introduction of new PLM methods, procedures and tools, and the need to improve processes efficiency and reduce time-to-market, led Airbus to pursue the Collaborative Engineering method. Processes efficiency is also impacted by the variety of systems existing within Airbus. Interoperability rises as a solution to eliminate inefficiencies due to information exchange and transformations and it also provides a way to discover and reuse existing information. The ARIADNE project (Value chain: from iDMU to shopfloor documentation of aeronautical assemblies) was launched to support the industrialization process of an aerostructure by implementing the industrial Digital Mock-Up (iDMU) concept in a Collaborative Engineering framework. Interoperability becomes an important research workpackage in ARIADNE to exploit and reuse the information contained in the iDMU and to create the shop floor documentation. This paper presents the context, the conceptual approach, the methodology adopted and preliminary results of the project

El "análisis de los caracteres", signos ambiguos y la idea de "sustitución" según Leibniz

Nuestro propósito en este escrito será investigar el tema de la "sustitución" en Leibniz en el contexto de lo que este autor denomina ars inveniendi (arte inventivo). Consideraremos, más específicamente, la utilización de algunas herramientas simbólicas empleadas en sus trabajos matemáticos a la luz de una serie de fragmentos filosóficos del autor inmediatamente posteriores a su estancia en París (1672 - 1676), período en el que se trazan las bases fundamentales del cálculo infinitesimal

Los usos de la optimización en una situación de selección

En el discurso Matemático Escolar la optimización es un proceso desprovisto de significaciones, procedimientos y argumentaciones, ya que existe una mayor centración en los objetos matemáticos utilizados en la aplicación de métodos de optimización que en sus usos. En este artículo se justifica la formulación de un Marco de Referencia de los usos de la optimización para valorar la justificación funcional que demandan otros dominios de conocimiento. De esta manera, se busca estrechar la distancia existente entre la matemática escolar y el cotidiano, con el fin de resignificar los usos de la optimización en el discurso Matemático Escolar

Industrial scale : estratègies metropolitanes per l'eficiència del transport industrial

El projecte "Industrial Scale" preten detectar i potenciar les condicions de contorn que ofereix un espai com el de l'estació de RENFE de Rubí. En primer lloc, detectem que és una estació molt infrautilitzada i d'ús pràcticament marginal, en un context totalment perifèric.D'altra banda, veiem potencial i oportunitat en la connectivitat a xarxes de mobilitat territorials, i la proximitat a grans superfícies de teixit industrial de caire productiu. A través d'un procés d'investigació hem observat que el transport amb tren és més eficient a nivell econòmic, energètic i ambiental. Amb aquestes condicions de contorn decidim intervenir sobre l'espai de l'estació de RENFE, proposant un canvi d'ús d'estació, de passatgers a port sec de mercaderies. Aquesta actuació permetrà al teixit industrial local una alternativa al transport rodat, a part de noves oportunitats i relacions econòmiques vinculades al corredor mediterrani de mercaderies, i per tant, un impacte socio-econòmic a la zona

Successful Latin American initiatives in biophysics

The II LAFeBS Congress aimed to promote a closer interaction between Latin American and Iberian Peninsula scientists in their respective fields of research, from structural proteomics to molecular bioenergetics. The speakers at this event reflected the importance and development of Biophysics in Latin American Countries, including Portugal and Spain; with 13 of them being invited to write review articles for this special issue of Biophysical Reviews. We hope that the integration of biophysics and biophysicists in Latin America, together with Portugal and Spain, through LAFeBS and POSLATAM can contribute to the future development of biophysics in these two historical partner regions.Instituto Multidisciplinario de Biología Celula

Potential of aqueous ozone to control aflatoxigenic fungi in Brazil nuts

The Brazil nut (Bertholethia excelsa) is an important non timber forest product (NTFP) from the Amazonian forest. Despite their nutritious value, Brazil nuts are susceptible to contamination with Aspergillus section Flavi fungi and consequently with aflatoxins. Since aqueous ozone reduces microorganisms population and has oxidant effect on aflatoxins, the effect of ozone on. Both natural and artificially contaminated Brasil nuts were studied in the present work. The former were inoculated with either 1x106 or 1x107 conidia mL-1 of A. flavus (MUM 9201). Previous assays were carried out to determine optimal parameters of the treatment. Different aqueous ozone contact time was assayed. The duration was controlled by the addition of a sodium formate solution. Such assays evidenced that the effect of ozone is almost immediate. Also, different ozone concentrations were assayed. The optimum ozone concentration depended on the initial viable spores on the nutshell. Also, the effect of the ozonization on the shell nut color was assessed by measuring chromaticity values of the treated fruits in the L*a*b* space coordinates. High concentrations of ozone affected both the luminosity and the hue of the nutshell. Finally, a concentrated aqueous ozone solution was assayed on both natural and artificially contaminated nuts. The remaining viable spores in the ozone solution were recorded and the rate of inactivation for each treatment was determined by assessing the ratio between the CFU of each treatment and the control. Ozonized nuts were also plated on MEA to recover the fungi population. Aqueous ozone was effective in reducing the conidia of Aspergillus flavus and the natural fungal population associated to Brazil nuts, although it seems to affect external appearance of the shell. The aqueous ozone solution may be recommended to control other mycotoxin producer Aspergilli, since ozone is regarded a generally recognized as safe (GRAS) product and it has been already used in many agricultural products, including the organically labels one like Brazil nuts.Fundação para a Ciência e a Tecnologia (FCT

Mohos productores de micotoxinas

info:eu-repo/semantics/publishedVersio

Avaliação das propriedades psicométricas do Questionário de Autorregulação Acadêmica (SRQ-A) em universitários chilenos

Introduction: The self-determination theory represents a framework to understand the factors that facilitate academic motivation, a relevant construct for educational contexts. One of the most used instruments to measure the construct is the Academic Self-Regulation Questionnaire (SQR-A), but there is a lack of psychometric background on the assessment of this measurement model of the Spanish version. Objective: To assess the factorial structure, internal consistency, and validity of the Academic Self-Regulation Questionnaire (SQR-A), in a sample of Chilean university students. Method: The participants were 808 students from two Chilean universities. The measurement model was evaluated using confirmatory factor analysis (CFA). The validity and reliability were assessed using mean-variance extracted and composite reliability. Results: The results show that the four-factor measurement model shows adequate levels of fit, in addition to adequate levels of validity and internal consistency. Conclusion: The Spanish version of the SRQ-A is a useful measure to be applied in higher education contexts.Introducción: La teoría de la autodeterminación representa un marco para comprender los factores que facilitan la motivación académica, constructo relevante para los contextos educativos. Uno de los instrumentos más utilizados para medir el constructo es el cuestionario de autorregulación académica (SRQ-A), pero se carece de antecedentes psicométricos sobre la evaluación de este modelo de medida en su versión en español. Objetivo: Evaluar la estructura factorial, consistencia interna y validez del cuestionario de autorregulación académica (SQR-A) en una muestra de estudiantes universitarios chilenos. Método: Los participantes fueron 808 estudiantes de dos universidades chilenas. El modelo de medida se evaluó mediante análisis factorial confirmatorio (AFC). La validez y confiabilidad se evaluaron mediante la varianza media extraída y la fiabilidad compuesta. Resultados: Los resultados muestran que el modelo de medida de cuatro factores presenta niveles de ajuste adecuados, además de niveles adecuados de validez y consistencia interna. Conclusión: La versión en español del SQR-A constituye una medida útil para ser aplicada en contextos de educación superior.Introdução: A teoria da autodeterminação representa um marco para compreender os fatores que facilitam a motivação acadêmica, construto relevante para os contextos educacionais. Um dos instrumentos mais utilizados para mensurar o construto é o questionário de autorregulação acadêmica (SRQ-A), mas faltam antecedentes psicométricos sobre a avaliação do modelo de medida da versão em espanhol do instrumento. Objetivo: Avaliar a estrutura fatorial, consistência interna e validade do questionário de autorregulação acadêmica (SQR-A) em uma amostra de estudantes universitários chilenos. Método: Os participantes foram 808 estudantes de duas universidades chilenas. O modelo de medida foi avaliado por meio de análise fatorial confirmatória (AFC). Validade e confiabilidade foram avaliadas por meio da variância média extraída e da confiabilidade composta. Resultados: Os resultados demonstram que o modelo de medida de quatro fatores apresenta níveis adequados de ajuste, bem como níveis adequados de validade e consistência interna. Conclusão: A versão em espanhol do SQR-A constitui uma medida útil para ser aplicada em contextos de ensino superior