842 research outputs found
Debiasing EQ-5D Tariffs. New estimations of the spanish EQ-5D value set under nonexpected utility
Este proyecto tiene como objetivo estimar las utilidades asociadas a los estados de salud definidos mediante el sistema EuroQol-5D a partir de la medición directa de las preferencias de una muestra de la población andaluza. Los valores obtenidos serán susceptibles de ser utilizados en el marco de estudios de evaluación económica de políticas sanitarias (análisis coste-utilidad) realizados en la comunidad andaluza y en el conjunto del estado. Para la valoración directa de un subconjunto de estados de salud se realizará una encuesta personal asistida por ordenador a una muestra representativa por sexo y cuotas de edad de la población española, extraída de la población residente en Andalucía. Los métodos que se aplicarán para obtener las preferencias y calcular las utilidades tratarán de corregir algunos de los sesgos que pueden afectar a las estimaciones existentes. Así, se adoptarán enfoques teóricos alternativos a los habitualmente empleados que permitirán relajar algunos de los supuestos que han sido puestos en cuestión a la luz de la evidencia empírica, como es el caso de la linealidad de la función de utilidad del tiempo de vida, la validez descriptiva de la teoría de la utilidad esperada o la separabilidad multiplicativa de las preferencias por cantidad y calidad de vida.EQ-5D, social tariff, utility curvature, probability weighting, rank-dependent utility, time trade-off, value lottery equivalence, certainlty equivalence
Improving scope sensitivity in contingent valuation: joint and separate evaluation of health states
We present data of a contingent valuation survey, testing the effect of evaluation mode on the monetary valuation of preventing road accidents. Half of the interviewees was asked to state their willingness to pay (WTP) to reduce the risk of having only 1 type of injury (separate evaluation, SE), and the other half of the sample was asked to state their WTP for 4 types of injuries evaluated simultaneously (joint evaluation, JE). In the SE group, we observed lack of sensitivity to scope while in the JE group WTP increased with the severity of the injury prevented. However, WTP values in this group were subject to context effects. Our results suggest that the traditional explanation of the disparity between SE and JE, namely, the so-called “evaluability,” does not apply here. The paper presents new explanations based on the role of preference imprecision
Noise Sources, Effects and Countermeasures in Narrowband Power-Line Communications Networks: A Practical Approach
The integration of Distributed Generation, Electric Vehicles, and storage without compromising the quality of the power delivery requires the deployment of a communications overlay that allows monitoring and controlling low voltage networks in almost real time. Power Line Communications are gaining momentum for this purpose since they present a great trade-off between economic and technical features. However, the power lines also represent a harsh communications medium which presents different problems such as noise, which is indeed affected by Distributed Generation, Electric Vehicles, and storage. This paper provides a comprehensive overview of the types of noise that affects Narrowband Power Line Communications, including normative noises, noises coming from common electronic devices measured in actual operational power distribution networks, and noises coming from photovoltaic inverters and electric vehicle charging spots measured in a controlled environment. The paper also reviews several techniques to mitigate the effects of noise, paying special attention to passive filtering, as for being one of the most widely used solution to avoid this kind of problems in the field. In addition, the paper presents a set of tests carried out to evaluate the impact of some representative noises on Narrowband Power Line Communications network performance, as well as the effectiveness of different passive filter configurations to mitigate such an impact. In addition, the considered sources of noise can also bring value to further improve PLC communications in the new scenarios of the Smart Grid as an input to theoretical models or simulations.This work has been partly funded by the Spanish Ministry of Economy and Competitiveness through the National Program for Research Aimed at the Challenges of Society under the project OSIRIS (RTC-2014-1556-3) and through the network of excellence REDYD2050 (ENE2015-70032-REDT)
Noise Sources, Effects and Countermeasures in Narrowband Power-Line Communications Networks: A Practical Approach
The integration of Distributed Generation, Electric Vehicles, and storage without compromising the quality of the power delivery requires the deployment of a communications overlay that allows monitoring and controlling low voltage networks in almost real time. Power Line Communications are gaining momentum for this purpose since they present a great trade-off between economic and technical features. However, the power lines also represent a harsh communications medium which presents different problems such as noise, which is indeed affected by Distributed Generation, Electric Vehicles, and storage. This paper provides a comprehensive overview of the types of noise that affects Narrowband Power Line Communications, including normative noises, noises coming from common electronic devices measured in actual operational power distribution networks, and noises coming from photovoltaic inverters and electric vehicle charging spots measured in a controlled environment. The paper also reviews several techniques to mitigate the effects of noise, paying special attention to passive filtering, as for being one of the most widely used solution to avoid this kind of problems in the field. In addition, the paper presents a set of tests carried out to evaluate the impact of some representative noises on Narrowband Power Line Communications network performance, as well as the effectiveness of different passive filter configurations to mitigate such an impact. In addition, the considered sources of noise can also bring value to further improve PLC communications in the new scenarios of the Smart Grid as an input to theoretical models or simulations.This work has been partly funded by the Spanish Ministry of Economy and Competitiveness through the National Program for Research Aimed at the Challenges of Society under the project OSIRIS (RTC-2014-1556-3) and through the network of excellence REDYD2050 (ENE2015-70032-REDT)
La valoración monetaria de los costes humanos de la siniestralidad vial en España
ResumenLos análisis coste-beneficio en el ámbito de la seguridad vial han de computar la totalidad de los costes, y dentro de ellos ocupan un lugar clave los costes humanos. En esta nota se da cuenta de dos estudios promovidos por la Dirección General de Tráfico orientados a la obtención de valores oficiales para España de los costes asociados a las víctimas mortales y no mortales de los accidentes de tráfico. Mediante la combinación del enfoque de la valoración contingente con la técnica de la lotería estándar (modificada), y con muestras amplias (n1=2020, n2=2000) representativas de la población española, se estimó en 1,4 millones de euros el valor monetario de prevenir un fallecido por accidente de tráfico. Para las lesiones graves y leves, los valores estimados fueron de 219.000 y 6100 euros, respectivamente. Las cifras obtenidas tienen un orden de magnitud similar al de los países de nuestro entorno.AbstractCost-benefit analyses in the field of road safety compute human costs as a key component of total costs. The present article presents two studies promoted by the Directorate-General for Traffic aimed at obtaining official values for the costs associated with fatal and non-fatal traffic injuries in Spain. We combined the contingent valuation approach and the (modified) standard gamble technique in two surveys administered to large representative samples (n1=2,020, n2=2,000) of the Spanish population. The monetary value of preventing a fatality was estimated to be 1.4 million euros. Values of 219,000 and 6,100 euros were obtained for minor and severe non-fatal injuries, respectively. These figures are comparable to those observed in neighboring countries
Estudio para la evaluación e introducción de tiendas de conveniencia online y offline en Colombia
Este estudio realizado a través de la presente tesis, pretende orientar y sustentar
la necesidad de introducir en las principales Ciudades de Colombia, tiendas de
conveniencia, con espacios contemplados entre 200 y 300 metros cuadrados, con un
énfasis en ventas Online y en cercanía a zonas altamente pobladas de estratos 4,5 y 6.
La finalidad, por la que se ha realizado esta investigación, es para soportar la
necesidad que tienen los colombianos que viven en las principales ciudades del país, en
tener soluciones de compra de artículos de primera necesidad cerca a sus hogares. Lo
anterior soportado en la limitación que hoy en día tienen las personas para visitar un
hipermercado, supermercado o formato similar, buscando tener soluciones más cercanas
a sus hogares y adicional tener canales alternos de compra, para optimizar sus
transacciones, preferiblemente de forma Online desde sus dispositivos móviles.
La investigación fue realizada en las tres principales ciudades de Colombia
(Bogotá, Cali, Medellín), en donde se encuestaron hombres y mujeres, entre los 25 y los
59 años, de estratos socio económicos 4, 5 y 6.
En síntesis, los resultados obtenidos corroboran la necesidad de abrir tiendas de
conveniencia en estas principales ciudades, ya que el 34% considera que el tema de
cercanía es de gran importancia a la hora de definir donde comprar. Adicionalmente, el
52% de los encuestados considera de suma importancia que el servicio de entrega a
domicilio sea ágil y gratuito, un porcentaje del 48%, consideran sumamente importante el
horario, por lo que tener disponibilidad de 24 horas al día los 365 días del año es de gran
importancia, para el 52% de las personas encuestadas, poder comprar por canales alternos tipo online es relevante a la hora de efectuar sus compras. Las cifras antes descritas
ratifican la necesidad de abrir tiendas de conveniencia en las principales Ciudades de
Colombia, con un marcado énfasis en ventas online (91% de los encuestados ha realizado
compras online) y ubicaciones en lugares preferentes en zonas de estratos 4, 5, 6,
cercanas a los hogares, lo cual permite que el cliente tenga a su disposición el canal web
o la tienda física. La recomendación es realizar una primera apertura en la Ciudad de
Bogotá, en el Barrio Santa Bárbara y posteriormente, continuar la expansión a 4 puntos
adicionales, un punto en la Ciudad de Cali en el Barrio Chipichape y un punto en la
Ciudad de Medellín en el Barrio El Poblado.
El negocio analizado de tiendas de conveniencia, presenta viabilidad de
incursión en las principales ciudades de Colombia, entendiendo, que la inversión
aproximada de lanzamiento y apertura de la primera tienda tendrá un costo aproximado
de USD$1,7MM, con un margen bruto de cerca del 30% y un plazo de retorno de
inversión de 6 años para la primera tienda, a medida que se logren las aperturas de las
demás tiendas proyectadas, se lograran mejores volúmenes y negociaciones de escala
para mejorar el margen bruto y reducir el tiempo de retorno de la inversión.Tesi
Advances in the Role of Dark Septate Endophytes in the Plant Resistance to Abiotic and Biotic Stresses
Endophytic fungi have been studied in recent decades to understand how they interact with their hosts, the types of relationships they establish, and the potential effects of this interaction. Dark septate endophytes (DSE) are isolated from healthy plants and form melanised structures in the roots, including inter- and intracellular hyphae and microsclerotia, causing low host specificity and covering a wide geographic range. Many studies have revealed beneficial relationships between DSE and their hosts, such as enhanced plant growth, nutrient uptake, and resistance to biotic and abiotic stress. Furthermore, in recent decades, studies have revealed the ability of DSE to mitigate the negative effects of crop diseases, thereby highlighting DSE as potential biocontrol agents of plant diseases (BCAs). Given the importance of these fungi in nature, this article is a review of the role of DSE as BCAs. The findings of increasing numbers of studies on these fungi and their relationships with their plant hosts are also discussed to enable their use as a tool for the integrated management of crop diseases and pests
Low temperature magnetic properties of a Ni50Mn34In16 ball-milled metamagnetic shape memory alloy
[EN] The effect of the atomic disorder induced by ball-milling on the structure and the magnetic properties has been analyzed in a Ni50Mn34In16 metamagnetic shape memory alloy. The as-milled samples displayed an amorphous structure which crystallizes to a disordered B2 structure on annealing. On further annealing, several recovery processes leading to the austenitic L21 structure and the subsequent martensitic transformation are observed. As a result of the recovery processes, the magnetic order drastically varies concurrent with the long-range atomic order. In particular, the magnetism evolves from a frustrated magnetic state compatible with a canonical spin-glass, observed in the amorphous structure, to the well-developed ferromagnetic state.This work has been carried out with the financial support of the Spanish “Ministerio de Economía y Competitividad” and FEDER funding, projects no. MAT2012-37923 and MAT2015-65165-C2-R. I. Unzueta acknowledges financial support from the Basque Government Grant nos. IT-443-10 and PRE_2014_214
Identification of Ni-vacancy defect in Ni-Mn-Z (Z = Ga, Sn, In): An experimental and DFT positron annihilation study
[EN] By means of experimental positron-annihilation-lifetime measurements and theoretical density functional theory (DFT) positron-lifetime calculations, vacancy-type defects in Ni50Mn50−xSnx (x=25, 20,15,13,10) and Ni50Mn50−xInx (x=25,20,16,13) systems are systematically studied. The study is extended to Ni-Mn-Ga systems as well. Experimental results are complemented with electron-positron DFT calculations carried out within the local density approximation and generalized gradient approximation, where five different parametrizations accounting for the γ(r) enhancement factor are analyzed. Theoretical results indicate that the Boronski-Nieminen parametrization of γ(r) is the one that best predicts the experimental results, which ultimately enables us to identify VNi as the vacancy present in the studied samples. The characteristic positron lifetime related to VNi ranges between 181 and 191 ps in Ni-Mn-Sn/In systems. Positron-annihilation-lifetime spectroscopy results in these two systems delimit the lower bound of the achievable vacancy concentration, which is much larger compared with the reported values in Ni-Mn-Ga systems. The present work, along with setting the basis for positron simulations in Ni-Mn based Heusler alloys, delimits the effect that the variation of vacancies has in the martensitic transformation in Ni-Mn-Sn systemsThis work is supported by the Basque Government and Spanish Ministry of Economy and Competitiveness under grants IT-1005-16, IT-756-13 and MAT2015-65165-C2-R (MINECO/FEDER). I. Unzueta also wants to acknowledge the Basque Government Grant PRE-2014-214
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