Artículos en Revistas
Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/538
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Item New contributions to non linear process monitoring through kernel partial least squares(2013) Vega, Jorge Ruben; Godoy, José Luis; Marchetti, Jacinto; Zumoffen, DavidThe kernel partial least squares (KPLS) method was originally focused on soft-sensor calibration for predicting online quality attributes. In this work, an analysis of the KPLS-based modeling technique and its application to nonlinear process monitoring are presented. To this effect, the measurement decomposition, the development of new specific statistics acting on non-overlapped domains, and the contribution analysis are addressed for purposes of fault detection, diagnosis, and prediction risk assessment. Some practical insights for synthesizing the models are also given, which are related to an appropriate order selection and the adoption of the kernel function parameter. A proper combination of scaled statistics allows the definition of an efficient detection index for monitoring a nonlinear process. The effectiveness of the proposed methods is confirmed by using simulation examples. Keywords: KPLS Modeling, Fault Detection, Fault Diagnosis, Prediction Risk Assessment, Nonlinear Processes.Item A fault detection and diagnosis technique for multivariate processes using a PLS-decomposition of the measurement space(2013) Vega, Jorge Ruben; Godoy, José Luis; Marchetti, JacintoA newstatisticalmonitoring technique based on partial least squares (PLS) is proposed for fault detection and di- 24 agnosis inmultivariate processes that exhibit collinearmeasurements. A typical PLS regression (PLSR)modeling 25 strategy is first extended by adding the projections of the model outputs to the latent space. Then, a PLS- 26 decomposition of the measurements into four terms that belongs to four different subspaces is derived. In 27 Q2 order to online monitor the PLS-projections in each subspace, new specific statistics with non-overlapped do- 28 mains are combined into a single index able to detect process anomalies. To reach a complete diagnosis, a further 29 decomposition of each statistic was defined as a sum of variable contributions. By adequately processing all this 30 information, the technique is able to: i) detect an anomaly through a single combined index, ii) diagnose the 31 anomaly class from the observed pattern of the four component statistics with respect to their respective confi- 32 dence intervals, and iii) identify the disturbed variables based on the analysis of themain variable contributions 33 to each of the four subspaces. The effectiveness observed in the simulated examples suggests the potential appli- 34 cation of this technique to real production systems.Item Randomly-branched polymers by size exclusion chromatography with triple detection : computer simulation study for estimating errors in the distribution of molar mass and branching degree(2013) Vega, Jorge Rubén; Clementi, Luis A.; Meira, GregorioThis article theoretically evaluates the biases introduced into the distributions of molar masses (MMD) and the number of long chain branches per molecule (LCBD), when randomly-branched polymers are analyzed by size exclusion chromatography (SEC) with molar mass-sensitive detectors. The MMD of a polymer with tetrafunctional branch units has been calculated with the Stockmayer equation (1943); and an ideal SEC analysis has been simulated that assumes u-solvent, perfect measurements, and perfect fractionation by hydrodynamic volume except for a minor mixing in the detector cells. In ideal SEC, a negligible bias is introduced into the MMD, with the local dispersity exhibiting a maximum of 1.0035 at the high molar masses. This result is consistent with previous theoretical investigations, but differs qualitatively from experimental observationsofpolymerscontainingshort-andlong-chain branches. When including band broadening in the columns while still assuming perfect measurements, the MMDremainsessentiallyunbiased.Incontrast,poorMMD estimates are obtained when the chromatograms are contaminated with additive noise. Only qualitative estimates of the LCBD are possible, due to theoretical limitations combined with propagation of errors in a highly nonlinear calculation procedure.Item Capillary hydrodynamic fractionation of hydrophobic colloids: errors in the estimated particle size distribution(2013) Vega, Jorge Rubén; Clementi, Luis A.; Arretxe, Zohartze; Aguirreurreta, Ziortza; Agirre, Amaia; Leiza, José R.; Gugliotta, Luis M.Capillary hydrodynamic fractionation (CHDF) with turbidity detection at a single wavelength is an analytical technique that is often used for sizing the submicrometric particles of hydrophobic colloids. This article investigates three sources of errors that affect the particle size distribution (PSD) estimated by CHDF: diameter calibration errors, uncertainties in the particle refractive index (PRI), and instrumental broadening (IB). The study is based on simulated and experimental examples that involve unimodal and bimodal PSDs. Small errors in the diameter calibration curve can produce important deviations in the number average diameter due to systematic shifts suffered by the PSD modes. Moderate uncertainties in the PRI are unimportant in the analysis of unimodal PSDs, but in the specific case of bimodal PSDs, errors in the PRI can strongly affect the estimated number concentration of each mode. The typical IB correction (based on the IB function estimated from narrow standards) produces slightly erroneous average diameters but can lead to PSDs with underestimated widths and distorted shapes. In practice, the three investigated sources of errors can be present simultaneously, and uncertainties in the average diameters, the shape and width of the PSD, and the number concentration of the PSD modes are unavoidable.Item Relationships between PCA and PLS-regression(Revista Chem And Intell Lab Syst, 2014) Vega, Jorge Rubén; Godoy, José Luis; Marchetti, Jacinto L.This work aims at comparing several features of Principal Component Analysis (PCA) and Partial Least Squares Regression (PLSR), as techniques typically utilized for modeling, output prediction, and monitoring of multivariate processes. First, geometric properties of the decomposition induced by PLSR are described in relation to the PCA of the separated input and output data (X-PCA and Y-PCA, respectively). Then, analogies between the models derived with PLSR and YX-PCA (i.e., PCA of the joint input–output variables) are presented; and regarding to process monitoring applications, the specific PLSR and YX-PCA fault detection indices are compared. Numerical examples are used to illustrate the relationships between latent models, output predictive models, and fault detection indices. The three alternative approaches (PLSR, YX-PCA and Y-PCA plus X-PCA) are compared with regard to their use for statistical modeling. In particular, a case study is simulated and the results are used for enhancing the comprehension of the PLSR properties and for evaluating the discriminatory capacity of the fault detection indices based on the PLSR and YX-PCA modeling alternatives. Some recommendations are given in order to choose the more appropriate approach for a specific application: 1) PLSR and YX-PCA have similar capacity for fault detection, but PLSR is recommended for process monitoring because it presents a better diagnosing capability; 2) PLSR is more reliable for output prediction purposes (e.g., for soft sensor development); and 3) YX-PCA is recommended for the analysis of latent patterns imbedded in datasets.Item Anàlisis comparativo de las respuestas de alumnos de quìmica general sobre el cambio quìmico(2014) Avalis, Carlos; Noseda, Juan CarlosLa reacción química constituye el eje central para el proceso de enseñanza y aprendizaje de la química. Distintas líneas de investigación en la didáctica de la química, hacen referencia a la importancia de considerar tres niveles de representación de la materia para el proceso de enseñanza - aprendizaje del cambio químico; comprenderlos y relacionarlos es necesario para lograr un aprendizaje significativo de la química. Hasta el año 2013 el tema se desarrollaba: Clase teórica donde se explicaban los tres niveles de representación, para lo cual se utilizaba pizarrón y apoyo de power point, y clase de resolución de problemas en la que se aplican los conceptos desarrollados A partir del 2014 se implementó el uso de secuencias didácticas utilizando TIC como estrategias para la enseñanza y el aprendizaje del cambio químico. El objetivo de este estudio es determinar si el empleo de secuencias didácticas favorece la comprensión del cambio químico. Se analizaron las respuestas de los alumnos regulares de química general, 132 correspondientes al año 2013 y 115 al 2014, a una evaluación anónima y voluntaria, y el tiempo asignado fue de 40 minutos. Los resultados muestran una mejora en el proceso enseñanza aprendizaje del cambio químico, utilizando secuencias didácticas, esto se ve reflejado en los porcentajes totales que pasaron del 33,4 % (2013) al 68,5 % (2014).Item Extending the WS-Humantask architecture to support the resource perspective of BPEL processes(2014) Villarreal, Pablo; Stroppi, Luis Jesús Ramón; Chiotti, OmarThe globalization, modern markets, as well as new organizational management philosophies and advances in Information and Communications Technologies, encourage organizations to establish collaboration networks or interorganizational collaborations. In this paper we propose a technology solution based on software agents which allows supporting the management of collaborative business processes in environments dynamic inter-organizational collaborations. First, we propose a software agent platform that integrates in agent specification's the notions of Belief-Desire-Intention agent architecture with functionalities of process-aware information systems. The platform enables organizations to negotiate collaborations agreements in electronic format to establish dynamic inter-organizational collaborations and define the collaborative processes to be executed. Second, we propose a methodology that includes methods based on Model-Driven Development, which enable the generation of executable process models and the code of process-oriented agents, derived from conceptual models of collaborative processes. This methodology and methods are implemented and automated by software agents that enable the generations of these implementation artifacts, at run-time of the platform. Therefore, the platform enables the automatic generation of the technology solution that requires each organization to execute the agreed collaborative processes, where the generated artifacts are built and initialized in the platform, allowing the implementation and execution of these processes. In this way, the proposed agent-based platform allows to establish collaboration among heterogeneous and autonomous organizations focusing in the process-oriented integration.Item Software agents for management dynamic inter-organizational collaborations(2014) Villarreal, Pablo; Chiotti, Omar; Tello-Leal, EdgarThe globalization, modern markets, as well as new organizational management philosophies and advances in Information and Communications Technologies, encourage organizations to establish collaboration networks or interorganizational collaborations. In this paper we propose a technology solution based on software agents which allows supporting the management of collaborative business processes in environments dynamic inter-organizational collaborations. First, we propose a software agent platform that integrates in agent specification's the notions of Belief-Desire-Intention agent architecture with functionalities of process-aware information systems. The platform enables organizations to negotiate collaborations agreements in electronic format to establish dynamic inter-organizational collaborations and define the collaborative processes to be executed. Second, we propose a methodology that includes methods based on Model-Driven Development, which enable the generation of executable process models and the code of process-oriented agents, derived from conceptual models of collaborative processes. This methodology and methods are implemented and automated by software agents that enable the generations of these implementation artifacts, at run-time of the platform. Therefore, the platform enables the automatic generation of the technology solution that requires each organization to execute the agreed collaborative processes, where the generated artifacts are built and initialized in the platform, allowing the implementation and execution of these processes. In this way, the proposed agent-based platform allows to establish collaboration among heterogeneous and autonomous organizations focusing in the process-oriented integration.Item Software agents architecture for managing inter-organizational collaboration(2014) Villarreal, Pablo; Chiotti, Omar; Tello-Leal, EdgarThe globalization, modern markets, as well as new organizational management philosophies and advances in Information and Communications Technologies, encourage organizations to establish collaboration networks or interorganizational collaborations. In this paper we propose a technology solution based on software agents which allows supporting the management of collaborative business processes in environments dynamic inter-organizational collaborations. First, we propose a software agent platform that integrates in agent specification's the notions of Belief-Desire-Intention agent architecture with functionalities of process-aware information systems. The platform enables organizations to negotiate collaborations agreements in electronic format to establish dynamic inter-organizational collaborations and define the collaborative processes to be executed. Second, we propose a methodology that includes methods based on Model-Driven Development, which enable the generation of executable process models and the code of process-oriented agents, derived from conceptual models of collaborative processes. This methodology and methods are implemented and automated by software agents that enable the generations of these implementation artifacts, at run-time of the platform. Therefore, the platform enables the automatic generation of the technology solution that requires each organization to execute the agreed collaborative processes, where the generated artifacts are built and initialized in the platform, allowing the implementation and execution of these processes. In this way, the proposed agent-based platform allows to establish collaboration among heterogeneous and autonomous organizations focusing in the process-oriented integration.Item Selección del emplazamiento para instalación de generación distribuida en un corredor radial de 132 kV. Evaluación según estudios eléctricos en régimen estacionario(2014) Sangoi, Emmanuel; Cea, MarcosLa Argentina se encuentra inmersa en una profunda crisis energética. El retraso de inversiones en la red de transmisión ha propiciado, como solución inmediata y de corto plazo, la instalación de generación distribuida (GD). El corredor de 132 kV del noroeste de la Provincia de Santa Fe presenta una longitud extensa y demandas importantes en localidades agroindustriales. Frente a escenarios de máxima demanda, las caídas de tensión tornan dificultosa su operación normal. Por ello, han surgido proyectos de GD para instalar en la región, aunque su ubicación y potencias nominales no se corresponden a un óptimo desempeño del subsistema. En este trabajo se ha desarrollado una metodología tendiente a obtener los máximos módulos de potencia a instalar de GD y la ubicación óptima, según criterios de calidad del producto técnico, máxima eficiencia en el transporte y adaptación a las condiciones de diseño del equipamiento de las Estaciones Transformadoras (ET).Item Prioridad de instalación de proyectos de generación distribuida en un corredor radial según criterio de estabilidad de tensión(2014) Sangoi, Emmanuel; Cea, MarcosEl corredor radial del noroeste de la provincia de Santa Fe, debido a su gran extensión y demandas importantes, presenta serios inconvenientes para su operación normal frente a escenarios de máxima demanda. En trabajos anteriores el Grupo de Control y Seguridad Eléctrica ha evaluado la ubicación, el modo de despacho y los módulos de potencia más apropiados de la generación distribuida a instalar en la región. Este tipo de generación manifiesta impactos notables en los perfiles de tensión de un corredor radial. De acuerdo al desarrollo de las curvas P-V y Q-V, fue analizada la estabilidad de tensión del corredor y con ello se estableció un orden de prioridad en la ejecución de cada uno de los proyectos propuestos. Como aspecto desfavorable, se observa que una mayor inyección de potencia reduce el margen entre la tensión de colapso del sistema y la mínima admisible para la prestación normal del servicio.Item Modelado de una micro-fuente fotovoltaica con aporte de potencia eléctrica a una micro-red(2014) Sangoi, EmmanuelEn este trabajo, se implementa el modelo matemático de una celda fotovoltaica policristalina para simular el comportamiento de un panel solar genérico ante variaciones en la irradiancia y la temperatura ambiente. Con el modelo de panel ya validado, se plantea como primer caso de estudio una micro-fuente solar de 9,6 kWp que se conecta directamente a la red de baja tensión. Mediante simulaciones numéricas se analiza tanto el aporte energético como las curvas de potencia eléctrica inyectadas diariamente por este tipo de recurso distribuido. El modelo considera como datos de entrada a la información meteorológica de la ciudad de Santa Fe durante el año 2010. Los resultados permiten entender las características del comportamiento de una microfuente de este tipo y son parte de la información necesaria para el modelo dinámico de una microred eléctrica.Item Hacia el desarrollo de un repositorio institucional en UTN-FRSF : aspectos técnicos a considerar(2015) Ale, Mariel Alejandra; Gutiérrez, María de los Milagros; Ballejos, Luciana; Golobisky, FernandaLa creación de un repositorio institucional de acceso abierto para objetos digitales tiene como fin el difundir y discutir en la comunidad educativa de esta región los nuevos conceptos que se vienen gestando a fin de crear conciencia de la importancia de contar con una sociedad del conocimiento libre y plural, de fomentar el libre acceso, la reutilización, la visibilidad y la preservación de la propiedad intelectual universitaria en todas sus dimensiones. Uno de los problemas que se presentan en este tipo de sistemas es la interoperabilidad a nivel semántico, si bien el Sistema Nacional de Repositorios Digitales (SNRD) introduce lineamientos a cumplir en la implementación para poder ser cosechado, esto no es suficiente dado que los distintos repositorios pueden utilizar distintos estándares de metadatos. Este trabajo propone un marco conceptual para la implementación de repositorios institucionales en el contexto de universidades públicas, poniendo énfasis en la interoperabilidad semántica de la información contenida en los mismos. Se presenta desde un punto de vista tecnológico la implementación de un prototipo en la UTN – FRSF.Item Estimation of the particle size distribution of colloids from multiangle dynamic light scattering measurements with particle swarm optimization(2015) Vega, Jorge Ruben; Clementi, Luis A.In this paper particle Swarm Optimization (PSO) algorithms are applied to estimate the particle size distribution (PSD) of a colloidal system from the average PSD diameters, which are measured by multi-angle dynamic light scattering. The system is considered a nonlinear inverse problem, and for this reason the estimation procedure requires a Tikhonov regularization method. The inverse problem is solved through several PSO strategies. The evaluated PSOs are tested through three simulated examples corresponding to polysty-rene (PS) latexes with different PSDs, and two experimental examples obtained by simply mixing 2 PS standards. In general, the evalu-ation results of the PSOs are excellent; and particularly, the PSO with the Trelea’s parameter set shows a better performance than other implemented PSOs.Item Lightweight concrete : an alternative for recycling cellulose pulp(2015-04) Andrés, Federico N.; Beltramini, Loreley B.; Guilarducci, Anabela Guadalupe; Romano, Melisa S.; Ulibarrie, Nestor OscarFrom the analysis of the production process of molded pulp packaging, it can be seen that one of the residues generated in the molding is "pulp". When this waste cannot be reincorporated into the production line, is recovered by centrifugation in the effluent treatment system. With the intention of recycling this residue it was investigated the feasibility of their use in the manufacture of concrete blocks or panels lightened studying possible ways to use the material, either in the wet state (form is discharged from the process) or dry (dried in a controlled environment), analyzing the advantages and disadvantages of each alternative. For practical purposes, various dosages were proposed to maintain constant the amount of residue and varying the amounts and proportions of water and cement. Test specimens were made with various amounts of cement per m³ of concrete.Item Waste of molded pulp industry. Filler panel production for construction(2015-04) Andrés, Federico; Beltramini, Loreley B.; Guilarducci, Anabela Guadalupe; Romano, Melisa; Ulibarrie, Nestor OscarIn the production process for producing recycled pulp cellulose, there are waste generated by the raw material entering the system. This residue is separated from the pulp by physical methods, and is mainly composed of plastics, paper, laminated papers and other materials in smaller proportions. In order to recycle this waste, in this paper we analyze the viability of use in the production of insulated panels. With the untreated residue extracted from the plant, panels of 30 cm side and thickness of approximately 6 cm were made. On these panels, parameters such as density and compression strength were evaluated for the study of the homogeneity of the material obtainedItem Trabajo práctico integrador : estrategia para el desarrollo de competencias en carreras ingenieriles(RADI - Revista Argentina de Ingenería, 2016-10) Alzugaray, Gloria; Rodríguez Virasoro, Lucía; Orué, MatíasLos trabajos prácticos constituyen una estrategia ampliamente utilizada en la enseñanza, como actividad de afianzamiento de conceptos o para la evaluación de los objetivos de aprendizaje. Ante la necesidad de incorporar conocimiento sobre innovaciones tecnológicas en tiempo real, en un mundo signado por vertiginosos cambios científicos tecnológicos, el trabajo práctico integrador aparece como una herramienta potencialmente eficaz para acompañar la formación de los ingenieros. Se analiza cómo el trabajo práctico integrador genera competencias que hacen al quehacer científico tecnológico, tales como formular soluciones alternativas a las existentes en el mercado, seleccionar métodos, diseñar secuencias experimentales, analizar y elaborar conclusiones, entre otras.Item Un framework extensible para la integración de razonamiento basado en casos con aplicaciones empresariales orientadas a objetos(CONAIISI, 2017) Carignano, María Celeste; Gonnet, Silvio; Leone, HoracioEn la vida cotidiana, las personas utilizan su experiencia para resolver las situaciones que se presentan, recordando circunstancias similares y adaptando las soluciones en función de las características de cada problema particular. En el contexto empresarial, estas prácticas también se llevan a cabo. Muchas veces el conocimiento asociado a ciertas experiencias se encuentra distribuido en las aplicaciones existentes, por lo que solo es necesario identificarlo y definir mecanismos apropiados para poder recuperarlo y reutilizarlo. Razonamiento Basado en Casos es un paradigma de resolución de problemas que involucra el uso de experiencias pasadas para comprender y resolver nuevas situaciones. Se sustenta en la idea de que si una experiencia pasada fue exitosa puede ser utilizada en el presente, en su totalidad o como punto de partida, para decidir o resolver una nueva situación similar. Su principal hipótesis es que problemas similares tienen soluciones similares. En este trabajo, se presenta un framework cuyo objetivo es facilitar la implementación de Razonamiento Basado en Casos en aplicaciones empresariales orientadas a objetos con el fin de poder hacer uso de la experiencia y conocimiento adquirido en el pasado para solucionar y resolver situaciones actuales con calidad y consistenciaItem Estudio de fiabilidad de un método de valoración de clientes para la priorización de nuevos requerimientos(CONAIISI, 2017) Gonnet, Silvio; De Federico, Sara; Avogradini, Mariela; Melfi, LucianaLas empresas desarrolladoras de software agregan nuevas funcionalidades a sus productos a pedido de sus clientes. La decisión de elección de qué nuevos requerimientos serán implementados es un proceso delicado y crítico cuando el producto tiene una posición consolidada en el mercado y el número de solicitudes es alto. Usualmente este proceso es llevado a cabo por los CEOs de las empresas desarrolladoras de software, quienes deben tener en cuenta las reglas de negocio y múltiples factores que influyen tanto en el producto como en la empresa y los otros clientes. A partir de un relevamiento de las necesidades de las empresas desarrolladoras de software de la ciudad de Rosario, se identificó que muchos de estos factores se refieren al cliente solicitante, tales como su nivel financiero, su peso en el mercado, y su historia en la empresa. A partir de este relevamiento se propuso, una metodología de priorización que enfatiza la valoración del cliente desde todas las áreas de la organización. A partir de esta valoración se obtiene una calificación integral del cliente, la cual se relaciona a los requerimientos que éste solicite para realizar luego una priorización de las solicitudes de nuevas funcionalidades. El rol de esta calificación es tan fuerte en la priorización, que es necesario comprobar la fiabilidad de los métodos de valoración que se utilizan para obtenerla. Este trabajo muestra el estudio realizado para afirmar la fiabilidad del Método de Valoración citadoItem Learning path based-portfolio for personalized learning(2017-01) Romero, Lucila; Caliusco, María Laura; Gutiérrez, María de los MilagrosNowadays, lot of human activities have been affected by the use of technology needed to change in order to adapted. Particularly, in education domain the changes that occurred were not enough to break the traditional schemas of teaching. In this way, more and more people claim for real remodeling. Mainly, one of the most important subject is the necessity to adapt the teaching process to the particular characteristics of students, in a king of personalized learning. This work presents a conceptual framework, which proposes learning path based-portfolio as a way to personalize education. This framework uses semantic technologies, logical rules and agents to determine the student learning level and based on that propose course of actions.