Clasificación de variables y reconciliación de datos en ingeniería de procesos

Las medidas de proceso de las plantas térmicas se utilizan para tareas de control, evaluación de rendimientos, optimización de la operación, etc. Frecuentemente se dispone de más medidas que las necesarias. La reconciliación consiste en ajustar las medidas redundantes de modo que obedezcan las leyes de conservación y cualquier otra restricción que incorpore el modelo matemático de la planta. Como resultado: (i) se detectan y eliminan los errores sistemáticos de medida; (ii) se obtiene un conjunto consistente de medidas ajustadas; (iii) se estiman las variables no medidas por el método de máxima verosimilitud y (iv) se obtienen intervalos de confianza para los resultados. En este trabajo se propone el método de la descomposición QR para analizar, descomponer y resolver los problemas de reconciliación lineal. Los problemas de reconciliación no lineal pueden resolverse iterativamente linealizando las ecuaciones del modelo matemático. Se presenta un ejemplo para ilustrar la aplicación de los procedimientos de cálculo propuestos.Peer Reviewe

El perfil profesional de los formadores de formación continua en España

El objetivo de este trabajo es analizar y describir los perfiles profesionales del formador de formación continua en España. Con este propósito se ha elaborado un cuestionario estructurado que se ha aplicado de forma presencial a una muestra de 606 formadores a nivel nacional. El cuestionario ha proporcionado información sobre aspectos como el estatus socio-laboral del formador, el grado de profesionalización y la importancia de las competencias profesionales de los formadores. La información recabada ha sido analizada mediante métodos multivariantes para determinar los perfiles profesionales dominantes. El análisis cuantitativo incluye el Análisis de Componentes Principales Categóricos (CATPCA) para analizar las competencias y capacidades del formador y el análisis Cluster en Dos Fases para obtener los perfiles. De los resultados obtenidos se han deducido cuatro perfiles profesionales dominantes siendo las variables ocupacionales, experiencia profesional y de las capacidades las que mayor discrepancia provocan entre los cuatro perfiles hallados

Solving Multi-Objective Hub Location Problems with Robustness

Hub location problems (HLP) are considered in many logistic, telecommunications, and computer problems, where the design of these networks are optimized based on some objective(s) related to the cost or service. In those cases, direct routing between any origin and destination is not viable due to economic or technological constraints. From the seminal work of O'Kelly~\cite{OKelly86}, a huge number of works have been published in the literature. Early contributions were focused on analogue facility location problems, considering some assumptions to simplify the network design. Recent works have studied more complex models by incorporating additional real-life features and relaxing some assumptions, although the input parameters are still assumed to be known in most of the HLPs considered in the literature. This assumption is unrealistic in practice, since there is a high uncertainty on relevant parameters of real problems, such as costs, demands, or even distances. Consequently, a decision maker usually prefer several solutions with a low uncertainty in their objectives functions instead of the optimum solution of an assumed deterministic objective function. In this work we use a three-objective Integer Linear Programming model of the p-hub location problem where the average transportation cost, its variance, and the processing time in the hubs are minimized. The number of variables is $O(n^4)$ where $n$ is the number of nodes of the graph. ILP solvers can only solve small instances of the problems and we propose in this work the use of a recent hybrid algorithm combining a heuristic and exact methods: Construct, Merge, Solve, and AdaptUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Bogdanov-Takens resonance in time-delayed systems

We analyze the oscillatory dynamics of a time-delayed dynamical system subjected to a periodic external forcing. We show that, for certain values of the delay, the response can be greatly enhanced by a very small forcing amplitude. This phenomenon is related to the presence of a Bogdanov- Takens bifurcation and displays some analogies to other resonance phenomena, but also substantial differences.Comment: 14 pages, 8 figure

Planar ESPAR Array Design with Nonsymmetrical Pattern by Means of Finite-Element Method, Domain Decomposition, and Spherical Wave Expansion

The application of a 3D domain decomposition finite-element and spherical mode expansion for the design of planar ESPAR (electronically steerable passive array radiator) made with probe-fed circular microstrip patches is presented in this work. A global generalized scattering matrix (GSM) in terms of spherical modes is obtained analytically from the GSM of the isolated patches by using rotation and translation properties of spherical waves. The whole behaviour of the array is characterized including all the mutual coupling effects between its elements. This procedure has been firstly validated by analyzing an array of monopoles on a ground plane, and then it has been applied to synthesize a prescribed radiation pattern optimizing the reactive loads connected to the feeding ports of the array of circular patches by means of a genetic algorithm

On the Use of Parsing for Named Entity Recognition

[Abstract] Parsing is a core natural language processing technique that can be used to obtain the structure underlying sentences in human languages. Named entity recognition (NER) is the task of identifying the entities that appear in a text. NER is a challenging natural language processing task that is essential to extract knowledge from texts in multiple domains, ranging from financial to medical. It is intuitive that the structure of a text can be helpful to determine whether or not a certain portion of it is an entity and if so, to establish its concrete limits. However, parsing has been a relatively little-used technique in NER systems, since most of them have chosen to consider shallow approaches to deal with text. In this work, we study the characteristics of NER, a task that is far from being solved despite its long history; we analyze the latest advances in parsing that make its use advisable in NER settings; we review the different approaches to NER that make use of syntactic information; and we propose a new way of using parsing in NER based on casting parsing itself as a sequence labeling task.Xunta de Galicia; ED431C 2020/11Xunta de Galicia; ED431G 2019/01This work has been funded by MINECO, AEI and FEDER of UE through the ANSWER-ASAP project (TIN2017-85160-C2-1-R); and by Xunta de Galicia through a Competitive Reference Group grant (ED431C 2020/11). CITIC, as Research Center of the Galician University System, is funded by the Consellería de Educación, Universidade e Formación Profesional of the Xunta de Galicia through the European Regional Development Fund (ERDF/FEDER) with 80%, the Galicia ERDF 2014-20 Operational Programme, and the remaining 20% from the Secretaría Xeral de Universidades (Ref. ED431G 2019/01). Carlos Gómez-Rodríguez has also received funding from the European Research Council (ERC), under the European Union’s Horizon 2020 research and innovation programme (FASTPARSE, Grant No. 714150)

Tetranuclear [Rh4(μ-PyS2) 2(diolefin)4] complexes as building blocks for new inorganic architectures: Synthesis of coordination polymers and heteropolynuclear complexes with electrophilic d8 and d10 metal fragments

The reaction of [Rh4(μ-PyS2)2(cod) 4] (PYS2 = 2,6-pyridinedithiolate, cod = 1,5-cyclooctadiene) with CF3SO3Me gave the cationic complex [Rh4(μ-PyS2Me)2(cod) 4][CF3SO3]2 (1) with two 6-(thiomethyl)pyridine-2-thiolate bridging ligands from the attack of Me+ at the terminal sulfur atoms of the starting material. Under identical conditions [Rh4(μ-PyS2)2(tfbb)4] (tfbb = tetrafluorobenzobarrelene) reacted with CF3SO3Me to give the mixed-ligand complex [Rh4(μ-PyS2)(μ-PyS 2Me)(tfbb)4][CF3SO3] (2). The nucleophilicity of the bridging ligands in the complexes [Rh4(μ -PyS2)2(diolefin)4] was exploited to prepare heteropolynuclear species. Reactions with [Au(PPh3)(Me 2CO)][ClO4] gave the hexanuclear complexes [(PPh 3)2Au2Rh4(μ-PyS2) 2(diolefin)4][ClO4]2 (diolefin = cod (3), tfbb (4)). The structure of 4, solved by X-ray diffraction methods, showed the coordination of the [Au(PPh3)]+ fragments to the peripheral sulfur atoms in [Rh4(μ-PyS2) 2(diolefin)4 along with their interaction with the neighbor rhodium atoms. Neutral coordination polymers of formula [CIMRh 4(μ-PyS2)2(diolefin)4] n (M = Cu (5, 6), Au (7)) result from the self-assembly of alternating [Rh4(μ-PyS2)2(diolefin) 4] ([Rh4]) blocks and MCI linkers. The formation of the infinite polymetallic chains was found to be chiroselective for M = Cu; one particular chain contains exclusively homochiral [Rh4] complexes. Cationic heterometallic coordination polymers of formula [MRh 4(μ-PyS2)2(diolefin)4] n (M = Ag (8, 9), Cu (10, 11)) and [Rh5(μ-PyS 2)2(diolefin)5]n[BF 4]n (12, 13) result from the reactions of [Rh 4] with [Cu(CH3CN)4]BF4, AgBF 4, and [Rh(diolefin)(Me2CO)2]BF4, respectively. The heterometallic coordination polymers exhibit a weak electric conductivity in the solid state in the range (1.2-2.8) × 10-7 S cm-1.The financial support from Ministerio de Ciencia y Tecnología (MCyT(DGI)/FEDER, Projects BQU2002-00074 and BQU2000-1170) is gratefully acknowledged.Peer Reviewe