1,480 research outputs found

    Optimización temporal de las señales automáticas proporcionadas por indicadores técnicos bursátiles

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    [EN] Stock exchange indicators deliver buy/sell signals that enable analysts to improve the results of a strategy based strictly on fundamental analysis. Nonetheless, since the automatic implementation of signals as they appear may not yield optimal returns, the present paper analysed the suitability of using a series of technical indicators as guidance for portfolio results. A second aim pursued was to study how delaying the implementation of indicator signals may enhance profitability. A simulation was performed for the years 2005-2016 using the most representative index for the Spanish stock exchange, the IBEX35 and all its constituent securities, along with seven indicators (RoC, RSI, SMA, EMA, MACD, Bollinger bands and Stochastic Oscillator) and a total of 81 combinations of buy/sell lag times. The definition of three non-overlapping sub-periods to guarantee the reliability of the findings yielded a total of 61 236 simulated portfolios. The conclusion drawn from the results was that for certain combinations of indicators, delaying the implementation of buy/sell signals improves returns. More specifically, optimal lag times identified for RSI and EMA signals were shown to deliver statistically significant improvements in portfolio returns, irrespective of the period studied. Those findings were consistent the results of an alternative simulation in which the five securities that were both the most liquid and had the greatest impact on the index were not considered, to rule out the possible effect of the relative weight of securities on either portfolio returns or their normalisation.[ES] Los indicadores técnicos bursátiles transmiten al analista señales de compra/venta que, en el caso de ser ejecutadas en el momento de producirse, podrían no ser óptimas desde el punto de vista del resultado de la operación. El objetivo del presente trabajo es doble. En primer lugar, analizar la idoneidad del seguimiento de una batería de indicadores para la obtención de resultados en una cartera. En segundo lugar, estudiar cómo la introducción de retardos temporales entre las señales de los indicadores y la ejecución de las operaciones puede mejorar el resultado de la misma. Se ha realizado una simulación, para el intervalo 2005-2016, con 35 títulos y un índice, sobre 7 indicadores técnicos bursátiles (ROC, RSI, Cruce SMA, Cruce EMA, MACD, Bandas de Bollinger y oscilador estocástico) y un total de 81 combinaciones de retardos de compra/venta. La definición del modelo y la división en tres periodos no solapados genera un total de 61.236 carteras. Los resultados permiten concluir que existen combinaciones de indicador y retardos de compra/venta que proporcionan mejores resultados que la ejecución inmediata de la señal. Concretamente, se identifican retardos óptimos para RSI y cruce EMA que producen mejoras estadísticamente significativas en el resultado de una cartera de valores, independientemente del periodo estudiado. Estos resultados son consistentes con una simulación alternativa en la que se excluyó a los cinco activos más líquidos y de mayor capitalización, para descartar el posible efecto generado por el peso relativo de los valores en la rentabilidad de la cartera o en su normalización

    1,3-Dien-5-ynes: Versatile Building Blocks for the Synthesis of Carbo- and Heterocycles

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    1,3-Dien-5-ynes have been extensively used as starting materials for the synthesis of a wide number of different carbo- and heterocycles. The aim of this review is to give an overview of their utility in organic synthesis, highlighting the variety of compounds that can be directly accessed from single reactions over these systems. Thus, cycloaromatization processes are initially commented, followed by reactions directed toward the syntheses of five-membered rings, other carbocycles and, finally, heterocycles. The diverse methodologies that have been developed for the synthesis of each of these types of compounds from 1,3-dien-5-ynes are presented, emphasizing the influence of the reaction conditions and the use of additional reagents in the outcome of the transformations.Ministerio de Economía y Competitividad (MINECO) and FEDER (CTQ2013-41336-P, CTQ2013- 48937-C2-1-P, and CTQ2014-52488-R), Universidad de Alcalá (CCG2015/EXP-003) and Junta de Castilla y León (BU237U13

    Subjective symptoms related to GSM radiation from mobile phone base stations : a cross-sectional study

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    Objectives: We performed a reanalysis of the data from Navarro et al., 2003, in which health symptoms related to microwave exposure from mobile phone base stations (BS) were explored, including data obtained in a retrospective inquiry about fear of exposure from BS. Design: Cross-sectional study. Setting: La Ñora (Murcia), Spain. Participants: Participants with known illness in 2003 were subsequently disregarded: 88 participants instead of 101 (in 2003) were analysed. Since weather circumstances can influence exposure, we restricted data to measurements made under similar weather conditions. Outcomes and methods: A statistical method indifferent to the assumption of normality was employed: namely, binary logistic regression for modelling a binary response (e.g. suffering fatigue (1) or not (0)), and so exposure was introduced as a predictor variable. This analysis was carried out on a regular basis and bootstrapping [95% percentile method] was used to provide more accurate confidence intervals. Main outcome measures Results: The symptoms most related to exposure were: lack of appetite [odds ratio (OR)] = 1.58, 95% confidence interval (95%CI) = 1.23-2.03; lack of concentration [OR = 1.54, 95% CI = 1.25- 1.89]; irritability [OR = 1.51, 95% CI = 1.23-1.85]; and trouble sleeping [OR = 1.49, 95% CI = 1.20-1.84]. Changes in -2 log likelihood showed similar results. Concerns about the BS were strongly related with trouble sleeping [OR = 3.12, 95% CI = 1.10-8.86]. The exposure variable remained statistically significant in the multivariate analysis. The bootstrapped values were similar to the asymptotic confidence intervals. Conclusion: This study confirms our preliminary results. We observed that the incidence of most of the symptoms was related to exposure levels ¿ independently of the demographic variables and some possible risk factors. Concerns about adverse effects from exposure, despite being strongly related with sleep disturbances, do not influence the direct association between exposure and sleep

    Multiyear Life Cycle Assessment of switchgrass (Panicum virgatum L.) production in the Mediterranean region of Spain: A comparative case study

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    [EN] An LCA of the cultivation of switchgrass in the Mediterranean region of Spain is carried out, based on 2010-2013 inventory data from experimental plots of two sites, Moncofar and Orihuela. Thus, a 4-year cycle is evaluated, considering different sources of variability. The functional unit is 1 t of switchgrass (dry basis) for electricity generation. Besides typical impact categories, blue and green water consumption impacts are also addressed by using watershed-specific characterization factors. In 2010, the production in Orihuela is more input-intensive than it is in Moncofar, while the biomass yield is lower. This causes greater climate change as CO2-eq. (709.1 vs. 65.0 kg t(-1)) and greater metal depletion as Fe-eq. (8.1 vs. 1.5 kg t(-1)). In the subsequent years, the yields are higher in Orihuela, and Moncofar performs worse for some specific impact categories, mainly the toxicity-related ones, and also metal depletion as Fe-eq., but only in 2011 (2.0 vs. 1.2 kg t(-1)). Due to larger irrigation doses, the blue water impact as ecosystem-eq. water is always higher in Orihuela (e.g. in 2010, 2020 vs. 390 m(3) t(-1)). On the contrary, the green water impact, also as ecosystem-eq. water, is greater in Moncofar, except for the first year (86.8 vs. 15.2 m(3) t(-1)). Switchgrass from the two locations could be eligible for bioelectricity production in the European Union in accordance with the sustainability requirements for greenhouse gas savings. Ad hoc decisions on crop management are, however, critical to the environmental impacts, evidencing the importance of taking a multi-year approach.The research has been partially funded by the body Generalitat Valenciana through Fundacion Agroalimed, under the coordination of the Instituto Valenciano de Investigaciones Agrarias (IVIA). The authors would like to acknowledge the cooperatives Sociedad exportacion de agrios No 2 Coop. V. and Surinver for the guidance on the crop management.Escobar Lanzuela, N.; Ramírez-Sanz, C.; Chueca, P.; Molto Garcia, E.; Sanjuán Pellicer, N. (2017). Multiyear Life Cycle Assessment of switchgrass (Panicum virgatum L.) production in the Mediterranean region of Spain: A comparative case study. Biomass and Bioenergy. 107:74-85. doi:10.1016/j.biombioe.2017.09.008S748510

    Desarrollo de una placa de osteosíntesis personalizada como técnica de fijación y posicionamiento simultáneo del maxilar superior en osteotomías tipo Lefort I en cirugía ortognática

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    En este estudio se desarrolla una técnica de posicionamiento y fijación para osteotomías tipo Lefort I en cirugía ortognática. En concreto, se lleva a cabo una prueba de concepto de diseño de una placa de osteosíntesis multifunción customizada. Inicialmente se han analizado parámetros influyentes en la morfología y situación de la placa, según lo cual se ha diseñado la placa. Este diseño se ha validado mediante la impresión 3D de prototipos plásticos y ha sido validado por un cirujano maxilofacial especialista en cirugía ortognática. El resultado del diseño CAD (Computer-Aided Design) de la placa de osteosíntesis ha sido exitoso y se ha completado en un tiempo aceptable para una cirugía electiva. Gracias a las características de la placa se prevé que aumente la precisión del procedimiento y que, por tanto, se obtengan mejores resultados clínicos

    Desarrollo de una placa de osteosíntesis personalizada como técnica de fijación y posicionamiento simultáneo del maxilar superior en osteotomías tipo Lefort I en cirugía ortognática

    Get PDF
    En este estudio se desarrolla una técnica de posicionamiento y fijación para osteotomías tipo Lefort I en cirugía ortognática. En concreto, se lleva a cabo una prueba de concepto de diseño de una placa de osteosíntesis multifunción customizada. Inicialmente se han analizado parámetros influyentes en la morfología y situación de la placa, según lo cual se ha diseñado la placa. Este diseño se ha validado mediante la impresión 3D de prototipos plásticos y ha sido validado por un cirujano maxilofacial especialista en cirugía ortognática. El resultado del diseño CAD (Computer-Aided Design) de la placa de osteosíntesis ha sido exitoso y se ha completado en un tiempo aceptable para una cirugía electiva. Gracias a las características de la placa se prevé que aumente la precisión del procedimiento y que, por tanto, se obtengan mejores resultados clínicos

    An Expedient Method for the Umpolung Coupling of Enols with Heteronucleophiles

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    [EN] In this paper, we present an unprecedented and general umpolung protocol that allows the functionalization of silyl enol ethers and of 1,3-dicarbonyl compounds with a large range of heteroatom nucleophiles, including carboxylic acids, alcohols, primary and secondary amines, azide, thiols, and also anionic carbamates derived from CO2. The scope of the reaction also extends to carbon-based nucleophiles. The reaction relies on the use of 1-bromo-3,3-dimethyl-1,3-dihydro-1 lambda(3)[d][1,2]iodaoxole, which provides a key alpha-brominated carbonyl intermediate. The reaction mechanism has been studied experimentally and by DFT, and we propose formation of an unusual enolonium intermediate with a halogen-bonded bromide.The authors are grateful for support from the Swedish Research Council through Vetenskapsradet, and from the Goran Gustafsson Foundation. This project was also funded by the European Union's Horizon 2020 research and innovation programme under Grant Agreement 721223 and NordForsk through NordCO2 (85378)

    On the cup anemometer working condition monitoring

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    The analysis of the harmonic terms related to the rotational speed of a cup anemometer is a way to detect anomalies such as wear and tear, rotor non-symmetries (rotor damage) or problems at the output signal system. The research already done in this matter at the IDR/UPM Institute is now taken to cup anemometers working on the field. A 1-2 year testing campaign is being carried out in collaboration with Kintech Engineering. 2 Thies First Class Advanced installed at 58 m and 73 m height in a meteorology tower are constantly monitored. The results will be correlated to the anemometer performance evolution studied through several calibrations planned to be performed along the testing campaign

    Supercritical Water Gasification of Industrial Organic Wastes

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    La gasificación de agua supercrítica (GASC), en la que el agua supercrítica no solo es un disolvente para materiales orgánicos sino también un reactivo, es una de las aplicaciones para producir combustible a partir de recursos orgánicos. De esta forma, además de destruir las aguas residuales, se pretende aprovechar su potencial energético mediante la combustión del efluente gaseoso generado en el proceso, que contiene un alto poder calorífico debido a su alto contenido en hidrógeno e hidrocarburos ligeros. En este trabajo, el proceso GASC ha sido probado en un sistema de flujo continuo a escala de laboratorio con dos aguas residuales industriales diferentes que contienen una alta concentración de compuestos orgánicos, y ambos residuos tienen un alto potencial energético: residuos de aceite de corte (aguas residuales oleaginosas de industrias metalúrgicas) y vinazas (aguas residuales de destilerías de alcohol). Estudios sobre el proceso GASC de este tipo de aguas residuales no han sido publicado todavía. Se estudió la influencia de la temperatura, cantidad de oxidante y adición de catalizador sobre el rendimiento y composición de la fase gaseosa generada. Los experimentos se llevaron a cabo en el rango de temperatura de 450 a 550 ºC, la cantidad de oxidante varió desde la ausencia de oxígeno (coeficiente de oxígeno, n = 0) hasta el 20% de oxígeno estequiométrico (n = 0,2), y 250 bar de presión en todos los casos. Se obtuvo un máximo de 0,19 moles de H2 por DQOm inicial (DQOm se expresa como mol de O2 consumido para la oxidación total) en la fase gaseosa en las mejores condiciones.Supercritical Water Gasification (SCWG), in which supercritical water is not only a solvent for organic materials but also a reactant, is one of the applications for producing fuel from organic resources. In this way, besides the destruction of wastewaters, it is aimed to harness their energy potential by burning the gas effluent generated in the process, which contains a high level of heating power due to its high content in hydrogen and light hydrocarbons. In the work described here, SCWG has been tested on a laboratory scale continuous flow system with two different industrial wastewaters that contain a high concentration of organics, with both wastes having a high energy potential: cutting oil wastes, oleaginous wastewater from metalworking industries, and vinasses, alcohol distillery wastewater. Reports on SCWG processes on these types of wastewaters have not previously been published in the literature. The influence of the temperature, amount of oxidant and catalyst addition on the yield and composition of the gas phase generated were studied. Experiments were carried out in the temperature range 450 to 550 ºC, the amount of oxidant ranged from the absence of oxygen (oxygen coefficient, n = 0) to 20% of stoichiometric oxygen (n = 0.2), and 250 bar of pressure in all cases. A maximum of 0.19 mol H2 per initial CODm (CODm is given as mol O2 consumed for total oxidation) was obtained in the gas phase under the best conditions.Ministerio de Ciencia y Tecnología (proyecto CTQ2004-05605
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