4,187 research outputs found
An optimal transportation approach for assessing almost stochastic order
When stochastic dominance does not hold, we can improve
agreement to stochastic order by suitably trimming both distributions. In this
work we consider the Wasserstein distance, , to stochastic
order of these trimmed versions. Our characterization for that distance
naturally leads to consider a -based index of disagreement with
stochastic order, . We provide asymptotic
results allowing to test vs , that,
under rejection, would give statistical guarantee of almost stochastic
dominance. We include a simulation study showing a good performance of the
index under the normal model
Regression-based seasonal unit root tests
The contribution of this paper is three-fold. Firstly, a characterisation theorem of the sub-hypotheses comprising the seasonal unit root hypothesis is presented which provides a precise formulation of the alternative hypotheses against which regression-based seasonal unit root tests test. Secondly, it proposes regressionbased tests for the seasonal unit root hypothesis which allow a general seasonal aspect for the data and are similar both exactly and asymptotically with respect to initial values and seasonal drift parameters. Thirdly, limiting distribution theory is given for these statistics where, in contrast to previous papers in the literature, in doing so it is not assumed that unit roots hold at all of the zero and seasonal frequencies. This is shown to alter the large sample null distribution theory for regression t-statistics for unit roots at the complex frequencies, but interestingly to not affect the limiting null distributions of the regression t-statistics for unit roots at the zero and Nyquist frequencies and regression Fstatistics for unit roots at the complex frequencies. Our results therefore have important implications for how tests of the seasonal unit root hypothesis should be conducted in practice. Associated simulation evidence on the size and power properties of the statistics presented in this paper is given which is consonant with the predictions from the large sample theory.Seasonal unit root tests; seasonal drifts; characterisation theorem
Supramolecular polymer networks based on cucurbit[8]uril host-guest interactions as aqueous photo-rheological fluids
A low-mass fraction (≤0.75 wt%) supramolecular polymer network is fabricated as an aqueous photo-rheological fluid (PRF) via cucurbit[8]uril mediated host–guest interactions. UV irradiation can induce the transition from a highly viscous and rigid gel into a Newtonian-like fluid.C.S.Y.T. thanks Ministry of Education of Malaysia and MARA University of Technology for their financial supports. J. L. is financially supported by the Marie Curie FP7 SASSYPOL ITN programme. J.d.B. is grateful for a Marie Curie Intra-European Fellowship (Project 273807). O.A.S thanks the ERC for their funding.This is the final version of the article. It first appeared from RSC via http://dx.doi.org/10.1039/C5PY01115
La investigació formativa en l’assignatura optativa d’informática aplicada a la investigació educativa
Podeu consultar el document complet a: http://diposit.ub.edu/dspace/handle/2445/65797En la investigació formativa l’alumnat és protagonista actiu del seu propi procés, fent del
professorat un acompanyant cap a l’aprenentatge autònom. L’alumnat adopta un rol actiu,
prenent les seves pròpies decisions, integrant coneixements, i desenvolupant competències
diverses. En aquesta innovació apostem per l’aprenentatge orientat a projectes (ABP) i
l’avaluació amb portafolis digital, com estratègies per a la investigació formativa. La finalitat de
l’estudi que presentem és l’anàlisi de la innovació en una assignatura del grau de Pedagogia,
des de la perspectiva de l’alumnat participant; mitjançant el mètode per enquesta.
Els principals resultats obtinguts evidencien la idoneïtat de la innovació docent implementada
per tal de potenciar el desenvolupament d’habilitats de pensament d’ordre superior. L’ABP
afavoreix l’adquisició i integració dels nous coneixements; destaquem especialment el
desenvolupament de dues competències bàsiques com són el treball col·laboratiu i la capacitat
de reflexió. Per al desenvolupament d’aquestes competències han resultat especialment útils,
segons l’alumnat, les activitats d’aprenentatge autònom, les activitats col·laboratives, les del
projecte d’investigació i el portafolis
Drivers of change and conservation needs for vertebrates in drylands: an assessment from global scale to Sahara-Sahel wetlands
Drylands range across more than half of the global terrestrial area and harbour about a quarter of continental vertebrate species, many of them endemic. However, this fauna is being increasingly threatened, in particular the one that inhabits deserts, one of the last biomes on earth. This work tracks the most relevant global change drivers acting on drylands, especially in deserts and arid regions, the conservation actions being developed, and the research needs for vertebrate conservation, following IUCN standardised classification schemes. Using the Sahara-Sahel wetlands as case study, it is provided a detailed examination of these aspects to support regional biodiversity conservation and human welfare. Deserts and arid regions are threatened by the synergistic effects of increasing development of urban areas, agriculture, energy production, mining, transportation and service corridors, resulting in pollution, invasive species, human intrusions and disturbance, biological resource overuse and in general, natural system modifications. In addition, climate change together with social underdevelopment of many desert-range countries places the mitigation of threat factors in a large and complex web of global-local societal challenges. Conservation actions targeting land/water and species protection and management, as well as education, awareness, capacity building, and legislation measures to increase livelihood development, are being developed. Additional research efforts are need to enhance biodiversity conservation planning, monitoring biodiversity and land-degradation status (based on Essential Biodiversity Variables), and quantification of socioeconomic factors associated with sustainable use of natural resources and human development. Sahara-Sahel wetlands are important life-support systems for both humans and vertebrates, the last vulnerable to listed global threats. They offer framework scenario to revert current environmental and societal challenges in deserts. Long-term conservation of desert vertebrate biodiversity requires appropriate policy instruments to promote sustainable use of natural resources. Raising environmental alertness within local communities of uniqueness of desert biodiversity is needed to promote policy change
Growth and yield models in Spain: historical overview, contemporary examples and perspectives
Producción CientíficaIn this paper we present a review of forest models developed in Spain in recent years for both timber and non timber production and forest dynamics (regeneration, mortality,..). Models developed are whole stand, size (diameter) class and individual-tree. The models developed to date have been developed using data from permanent plots, experimental sites and the National Forest Inventory. In this paper we show the different sub-models developed so far and the friendly use software. Main perspectives of forest modelling in Spain are presented
The antecedent role of a collaborative vs. a controlling corporate culture on firm-wide integrated marketing communication and brand performance
This study aims to (i) demonstrate the influence of two types of corporate culture (CC), namely collaborative and controlling, on firm-wide integrated marketing communication (IMC) implementation; and (ii) examine the mediating role of IMC on the relationship between CC and brand performance (BP). Data were gathered via a self-administered online survey among senior managers of service businesses (n = 180) and analyzed via path analysis. Findings show that the adoption of a collaborative culture positively affects IMC, and to a greater extent than a controlling culture. It is also found that IMC exerts a beneficial effect on brand competitive advantage. A key contribution of this study lies in providing empirical evidence of the mediation of IMC in the relationship between CC and BP, thus suggesting that, in terms of the resource-based view (RBV), IMC contributes to fostering organizational capability to translate organizational cultural values into competitive advantage.Este estudio pretende (i) demostrar la influencia de dos tipos de cultura corporativa (CC), la colaborativa y la controladora, en la implementación de la comunicación de marketing integrada (CMI) en toda la empresa; y (ii) examinar el papel mediador de la CMI en la relación entre la CC y el rendimiento de la marca (PB). Los datos se recopilaron mediante una encuesta en línea autoadministrada a altos directivos de empresas de servicios (n = 180) y se analizaron mediante análisis de trayectorias. Los resultados muestran que la adopción de una cultura de colaboración afecta positivamente a la CIM, y en mayor medida que una cultura de control. También se constata que la CIM ejerce un efecto beneficioso sobre la ventaja competitiva de las marcas. Una contribución clave de este estudio reside en aportar pruebas empíricas de la mediación de la CIM en la relación entre CC y BP, sugiriendo así que, en términos de la visión basada en los recursos (VBR), la CIM contribuye a fomentar la capacidad organizativa para traducir los valores culturales de la organización en ventajas competitivas.Junta de Andalucía [proyecto P12-SEJ2592]Gobierno Español [proyecto ECO2017-88458-R
- …