K1,3K_{1,3}-covering red and blue points in the plane

We say that a finite set of red and blue points in the plane in general position can be $K_{1,3}$-covered if the set can be partitioned into subsets of size $4$, with $3$ points of one color and $1$ point of the other color, in such a way that, if at each subset the fourth point is connected by straight-line segments to the same-colored points, then the resulting set of all segments has no crossings. We consider the following problem: Given a set $R$ of $r$ red points and a set $B$ of $b$ blue points in the plane in general position, how many points of $R\cup B$ can be $K_{1,3}$-covered? and we prove the following results: (1) If $r=3g+h$ and $b=3h+g$, for some non-negative integers $g$ and $h$, then there are point sets $R\cup B$, like $\{1,3\}$-equitable sets (i.e., $r=3b$ or $b=3r$) and linearly separable sets, that can be $K_{1,3}$-covered. (2) If $r=3g+h$, $b=3h+g$ and the points in $R\cup B$ are in convex position, then at least $r+b-4$ points can be $K_{1,3}$-covered, and this bound is tight. (3) There are arbitrarily large point sets $R\cup B$ in general position, with $r=b+1$, such that at most $r+b-5$ points can be $K_{1,3}$-covered. (4) If $b\le r\le 3b$, then at least $\frac{8}{9}(r+b-8)$ points of $R\cup B$ can be $K_{1,3}$-covered. For $r>3b$, there are too many red points and at least $r-3b$ of them will remain uncovered in any $K_{1,3}$-covering. Furthermore, in all the cases we provide efficient algorithms to compute the corresponding coverings.Comment: 29 pages, 10 figures, 1 tabl

Enhanced CORILGA: Introducing the Automatic Phonetic Alignment Tool for Continuous Speech

The Corpus Oral Informatizado da Lingua Galega (CORILGA) project aims at building a corpus of oral language for Galician, primarily designed to study the linguistic variation and change. This project is currently under development and it is periodically enriched with new contributions. The long-term goal is that all the speech recordings will be enriched with phonetic, syllabic, morphosyntactic, lexical and sentence ELAN-complaint annotations. A way to speed up the process of annotation is to use automatic speech-recognition-based tools tailored to the application. Therefore, CORILGA repository has been enhanced with an automatic alignment tool, available to the administrator of the repository, that aligns speech with an orthographic transcription. In the event that no transcription, or just a partial one, were available, a speech recognizer for Galician is used to generate word and phonetic segmentations. These recognized outputs may contain errors that will have to be manually corrected by the administrator. For assisting this task, the tool also provides an ELAN tier with the confidence measure of each recognized word. In this paper, after the description of the main facts of the CORILGA corpus, the speech alignment and recognition tools are described. Both have been developed using the Kaldi toolki

CORILGA: a Galician Multilevel Annotated Speech Corpus for Linguistic Analysis [Póster]

Póster presentado no 9th Language Resources and Evaluation Conference (LREC 2014). Reykjavik, 26-31 maio 2014FEDER, Xunta de Galicia, Goberno de Españ

Análisis teórico-experimental del comportamiento de una bomba de calor con sistema de captación híbrido geotérmico-aerotérmico

La climatización y producción de ACS mediante bombas de calor está experimentando un importante desarrollo, tanto a nivel tecnológico como de implantación debido a la necesidad de sistemas cada vez más eficientes. Estos sistemas se basan en el aprovechamiento del calor existente en un medio (tierra, agua o aire) para transferirlo al lugar a climatizar, siendo los sistemas que emplean el aire ambiente (aerotermia) y el calor existente bajo la superficie terrestre (geotermia) los que mayor nivel de implantación han alcanzado. Si bien la solución más habitual pasa por el empleo de alguna de estas dos tecnologías de modo independiente, actualmente se están comercializando equipos que combinan ambos sistemas, de modo que se consiguen aprovechar las ventajas particulares de cada uno de ellos, como son el menor coste del captador aerotérmico frente al geotérmico, el aprovechamiento de periodos con elevadas temperaturas del aire ambiente o la posibilidad de funcionamiento aun en casos con riesgo de congelación del terreno. Teniendo en cuenta la escasa información sobre este tipo de equipos, se ha llevado a cabo un estudio teórico-experimental con el que pretende alcanzar una mejor compresión sobre el funcionamiento de este tipo de sistemas, obteniendo mapas de funcionamiento que permitan establecer el sistema de captación óptimo en función de las condiciones ambientales. Para ello se ha construido un banco de ensayos que ha permitido estudiar el comportamiento de una bomba de calor comercial acoplada a un aerotermo, a un sistema que simula los pozos geotérmicos o a ambos elementos en serie

K1,3-covering red and blue points in the plane

We say that a finite set of red and blue points in the plane in general position can be K1, 3-covered if the set can be partitioned into subsets of size 4, with 3 points of one color and 1 point of the other color, in such a way that, if at each subset the fourth point is connected by straight-line segments to the same-colored points, then the resulting set of all segments has no crossings. We consider the following problem: Given a set R of r red points and a set B of b blue points in the plane in general position, how many points of R ¿ B can be K1, 3-covered? and we prove the following results: (1) If r = 3g + h and b = 3h + g, for some non-negative integers g and h, then there are point sets R ¿ B, like {1, 3}-equitable sets (i.e., r = 3b or b = 3r) and linearly separable sets, that can be K1, 3-covered. (2) If r = 3g + h, b = 3h + g and the points in R ¿ B are in convex position, then at least r + b - 4 points can be K1, 3-covered, and this bound is tight. (3) There are arbitrarily large point sets R ¿ B in general position, with r = b + 1, such that at most r + b - 5 points can be K1, 3-covered. (4) If b = r = 3b, then at least 9 8 (r + b- 8) points of R ¿ B can be K1, 3-covered. For r > 3b, there are too many red points and at least r - 3b of them will remain uncovered in any K1, 3-covering. Furthermore, in all the cases we provide efficient algorithms to compute the corresponding coverings

Efecto del cambio de refrigerante en un sistema de producción de hielo líquido con generador de tipo rascador

El hielo líquido es un fluido secundario con un elevado potencial debido a su alta densidad de energía gracias al aprovechamiento del calor latente de cambio de fase de microcristales de hielo en una disolución acuosa, lo que permite su bombeo sin necesidad de equipos especiales. Hasta día de hoy, se han planteado muy distintos sistemas de generación de hielo líquido, de los cuales los generadores de superficie rascada son los que mayor nivel de implantación comercial han alcanzado. Por otra parte, las reglamentaciones existentes en referencia al uso de los refrigerantes halogenados hacen que sea necesario dar solución a aquellos sistemas que originalmente empleaban refrigerantes de tipo CFCs y HCFCs. En este trabajo, se analiza experimentalmente el efecto de la sustitución directa de R22 por R417A en un equipo de generación de hielo líquido con generador de superficie rascada. En el artículo, se describe el equipo experimental utilizado, se detalla la metodología experimental seguida y se presentan y analizan los principales resultados obtenidos

Work environment, stress, and driving anger: a structural equation model for predicting traffic sanctions of public transport drivers

Public transport is an effective and sustainable alternative to private vehicle usage, also helping to reduce the environmental impact of driving. However, the work environment of public transport operators is full of adverse conditions, which, together with their high mileage, may increase the occurrence of negative safety outcomes such as traffic accidents, often preceded by risky road behaviors enhanced by stress, anger, and difficult operating conditions. The aims of this study were, first, to determine the association between work-related psychosocial factors and individual characteristics of public transport drivers and the rate of traffic sanctions they are subject to; and second, to assess the mediation of driving anger in this relationship. A sample of professional drivers (57.4% city bus, 17.6% taxi, and 25% inter-urban bus male operators) was used for this cross-sectional study, responding to a five-section survey including demographic data and driving-related factors, psychosocial work factors including job stress, driving stress, risk predisposition, and driving anger. The results of this study showed significant associations between work-related factors: measures of stress and self-reported rates of traffic fines. Second, it was found that driving anger mediates the associations between driving stress, risk predisposition, and traffic sanctions; and partially mediates the association between driving experience, hourly intensity, and job stress. This study supports the idea that traffic penalties reported by public transport rates are preceded by work-related, personality, and other individual factors that, when combined with driving anger, enhance the occurrence of road misbehavior that may affect overall road safet

Optimización del dimensionado del sistema de captación de una bomba de calor geotérmica según la zona climática

Las bombas de calor geotérmicas pueden implicar ahorros energéticos importantes en comparación con sistemas de climatización clásicos, gracias al aprovechamiento del terreno, cuyas temperaturas son muy estables a lo largo del año, como foco térmico. El tamaño de los sistemas de captación va a influir notablemente en la eficiencia de las bombas de calor, por lo que es fundamental obtener una solución de compromiso entre las prestaciones de las bombas de calor y la inversión necesaria. Este artículo parte de un trabajo previo en el que se estudió el comportamiento de una bomba de calor geotérmica con inversión de ciclo al variar la superficie de intercambio (el número de pozos activos) del sistema de captación. Basándose en los datos experimentales obtenidos en dicho trabajo, y teniendo en cuenta los costes de este tipo de instalaciones, se ha realizado un análisis económico de la instalación, para analizar el impacto que tiene el número de perforaciones y la superficie de intercambio en el coste de la instalación y en el ahorro obtenido debido al aumento de la eficiencia, con el objetivo de alcanzar un dimensionado óptimo. Este análisis se ha realizado teniendo en cuenta las condiciones climáticas de capitales de provincia representativas de las zonas climáticas definidas según el Apéndice B de la Sección HE 1 del Documento Básico HE del Código Técnico de la Edificación. Se han obtenido diferentes soluciones y tiempos de retorno de la inversión según las condiciones ambientales consideradas

Experimental analysis of R-134a flow condensation in a smooth tube

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Condensation processes inside tubes are widely used in air conditioning and refrigeration industry, since they promote an improvement of the heat transfer, reducing the equipment size. The distribution of the liquid and vapour phases inside the tubes is crucial in the heat transfer process. Several studies have been carried out for flow regime maps and flow regime prediction techniques, in order to predict which flow pattern is expected according to parameters such as the geometry of the tubes, the flow rate and refrigerant properties. In this work, an experimental research was conducted to obtain different condensation flow patterns inside an 8 mm inner diameter smooth copper tube. Experiments were carried out for mass fluxes of 100, 200, 300, 400 and 600 kg/m2s, a saturation temperature of 40 ºC and varying the vapour quality from 0.20 to 0.80 at 0.15 intervals. Experimental photographs and videos are presented, discussed and compared against the results provided by some flow pattern maps and prediction techniques found in the literature.dc201

Demographic market segmentation on short banking movement descriptions applying Natural Language Processing

Xunta de Galicia | Ref. GRC2018/05