2,441 research outputs found

    Characterization of Banach valued BMO functions and UMD Banach spaces by using Bessel convolutions

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    In this paper we consider the space BMOo(R,X)BMO_o(\mathbb{R},X) of bounded mean oscillations and odd functions on R\mathbb{R} taking values in a UMD Banach space XX. The functions in BMOo(R,X)BMO_o(\mathbb{R},X) are characterized by Carleson type conditions involving Bessel convolutions and γ\gamma-radonifying norms. Also we prove that the UMD Banach spaces are the unique Banach spaces for which certain γ\gamma-radonifying Carleson inequalities for Bessel-Poisson integrals of BMOo(R,X)BMO_o(\mathbb{R},X) functions hold.Comment: 29 page

    The relationship between public and private bicycle use: the case of Seville

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    Despite the success achieved by Public Bicycle Sharing Systems (PBSS) across the world, several researchers provide evidence on their limitations and constraints in a medium-long term, and bicycle ownership may be considered as a complementary tool to promote a 'bicycle-culture'. This paper aims to cover the gap about the interaction between both systems (public bicycle / private bicycle) and which are the key aspects to explain the bicycle-buying decision. After a fieldwork based on surveys conducted in Seville (Spain), one of the cities currently acknowledged worldwide for its successful policy of promoting cycling, we apply a Discrete Choice Model. Our findings show that among the socio-demographic factors that favor the move from the PBSS to the private bicycle are: having a higher level of education, being more progressive ideologically-speaking, and being a resident of the city itself; while age and gender do not appear to be conclusive. Experienced users, for whom the bicycle is a part of his /her healthy lifestyle, state a greater willingness to buy a bicycle. And the main obstacles to make the jump from the PBSS to the private bicycle, and that any action plan to support private bicycle usage should take into account, are: the lack of proper parking at the origin/destination, and fear of theft

    Characterization of UMD Banach spaces by imaginary powers of Hermite and Laguerre operators

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    In this paper we characterize the Banach spaces with the UMD property by means of Lp-boundedness properties for the imaginary powers of the Hermite and Laguerre operators. In order to do this we need to obtain pointwise representations for the Laplace transform type multipliers associated with Hermite and Laguerre operators.Comment: 17 page

    Variable exponent Hardy spaces associated with discrete Laplacians on graphs

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    In this paper we develop the theory of variable exponent Hardy spaces associated with discrete Laplacians on infinite graphs. Our Hardy spaces are defined by square integrals, atomic and molecular decompositions. Also we study boundedness properties of Littlewood-Paley functions, Riesz transforms, and spectral multipliers for discrete Laplacians on variable exponent Hardy spaces

    Discrete harmonic analysis associated with ultraspherical expansions

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    We study discrete harmonic analysis associated with ultraspherical orthogonal functions. We establish weighted l^p-boundedness properties of maximal operators and Littlewood-Paley g-functions defined by Poisson and heat semigroups generated by certain difference operator. We also prove weighted l^p-boundedness properties of transplantation operators associated to the system of ultraspherical functions. In order to show our results we previously establish a vector-valued local Calder\'on-Zygmund theorem in our discrete setting

    Conical square functions associated with Bessel, Laguerre and Schr\"odinger operators in UMD Banach spaces

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    In this paper we consider conical square functions in the Bessel, Laguerre and Schr\"odinger settings where the functions take values in UMD Banach spaces. Following a recent paper of Hyt\"onen, van Neerven and Portal, in order to define our conical square functions, we use γ\gamma-radonifying operators. We obtain new equivalent norms in the Lebesgue-Bochner spaces Lp((0,∞),B)L^p((0,\infty ),\mathbb{B}) and Lp(Rn,B)L^p(\mathbb{R}^n,\mathbb{B}), 1<p<∞1<p<\infty, in terms of our square functions, provided that B\mathbb{B} is a UMD Banach space. Our results can be seen as Banach valued versions of known scalar results for square functions

    Solutions of Weinstein equations representable by Bessel Poisson integrals of BMO functions

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    We consider the Weinstein type equation Lλu=0\mathcal{L}_\lambda u=0 on (0,∞)×(0,∞)(0,\infty )\times (0,\infty ), where Lλ=∂t2+∂x2−λ(λ−1)x2\mathcal{L}_\lambda=\partial _t^2+\partial _x^2-\frac{\lambda (\lambda -1)}{x^2}, with λ>1\lambda >1. In this paper we characterize the solutions of Lλu=0\mathcal{L}_\lambda u=0 on (0,∞)×(0,∞)(0,\infty )\times(0,\infty ) representable by Bessel-Poisson integrals of BMO-functions as those ones satisfying certain Carleson properties

    Factores psicosociales relacionados con el autocuidado en la prevención, tratamiento y postratamiento del cáncer de mama

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    This paper discusses psychosocial factors which influence self-care in breast cancer patients during prevention, treatment and after-treatment phases. Self-care is defined as the set of activities that a patient consciously develops to look after her life, health and well-being, an it must be supported all over the different stages of the disease. Three different theoretical models are presented – Health Beliefs Model, Theory of Reasoned Action and Self-regulation Model – that try to understand how and why people practice self-care in chronic conditions and in breast cancer. Finally, the paper reflects upon the importance of women’s strength of spirit, of family relations and psychological interventions to improve self-care in the different phases of the diseaseEn el presente artículo se discute acerca de los factores psicosociales asociados al autocuidado en el cáncer de mama durante la prevención, el tratamiento y el postratamiento. El autocuidado se refiere a un conjunto de actividades que la persona realiza de manera consciente para mantener su vida, su salud y su bienestar, y es necesario que sea incentivado durante todas las etapas de la enfermedad. Se presentan distintos modelos teóricos – Modelo de Creencias de la Salud, Teoría de la Acción Razonada y Modelo de Autorregulación en Salud - que intentan entender cómo y porqué las personas se cuidan en situaciones de enfermedad crónica y su aplicación en el cáncer de mama. Por último, se reflexiona sobre la importancia del estado de ánimo de la mujer afectada, de la familia y de las intervenciones psicológicas para fomentar el autocuidado en las distintas etapas de la enfermedad

    Measuring the LCC effect on charter airlines in the Spanish airport system

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    Using a robust transfer function model methodology, the present paper seeks to offer empirical evidence regarding the size and type of effects that low-cost carriers (LCCs) have had on traffic for charter carriers (CCs) in the Spanish airport system by geographic market. We show an unmistakable substitution relationship between CCs and LCCs in the latter’s typical niche markets, national and European flights, while there is no reaction from the CCs in the segment of international flights outside the EU. Furthermore, substitution effects are smaller between CCs and LCCs on the domestic level than effects between LCCs and network carriers (NCs) and slightly larger on the European level. Lastly, CC traffic’s different sensitivity to terrorist attacks, day of the week, air accidents and the economic crisis is also evident. CCs should therefore be considered an independent category that warrants individualized analyses

    BMO functions and Balayage of Carleson measures in the Bessel setting

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    By BMOo(R)BMO_o(R) we denote the space consisting of all those odd and bounded mean oscillation functions on R. In this paper we characterize the functions in BMOo(R)BMO_o(R) with bounded support as those ones that can be written as a sum of a bounded function on (0,∞)(0,\infty ) plus the balayage of a Carleson measure on (0,∞)×(0,∞)(0,\infty )\times (0,\infty ) with respect to the Poisson semigroup associated with the Bessel operator Bλ=−x−λDx2λDx−λB_\lambda =-x^{-\lambda }Dx^{2\lambda }Dx^{-\lambda}, λ>0\lambda >0. This result can be seen as an extension to Bessel setting of a classical result due to Carleson
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