Ajuste entre estrategias de diversificación y estructuras multidivisionales: efecto sobre el resultado

El objetivo del presente trabajo es analizar la coherencia entre la estrategia de diversificación y la estructura multidivisional y su efecto sobre los resultados empresariales para el conjunto de los grandes grupos empresariales españoles diversificados. Para ello, y con el fin también de profundizar en los conceptos multidimensionales de estrategias de diversificación y estructuras multidivisionales, se utiliza el enfoque de la coherencia como desviación a un perfil “ideal”. Los resultados muestran que existen tres categorías estratégicas (diversificación relacionada, diversificación no relacionada y diversificación basada en el conocimiento, cada una de las cuales posee unas características estructurales “ideales” distintas. No obstante, sólo en el caso de la diversificación basada en el conocimiento se ha podido comprobar que la falta de coher encia entre la estrategia y la estructura tiene consecuencias negativas en la rentabilidad

Diversification decisions among family firms: the role of family involvement and generational stage

While prior literature has focused on whether family firms are more or less inclined to diversification than non-family firms, the examination of differences in diversification among family firms has received much less attention. We analyze how family involvement (in ownership, control, and management) and the generational stage in the company (first versus later generations) influence diversification among family firms. The empirical evidence is provided by a sample of publicly listed family firms from the EU. Our results show that larger levels of family involvement in the firm are associated with lower diversification. Furthermore, first-generation family firms are found to be less diversified than their later-generation counterparts

When Economics Meets Arts... in the Classroom

The aim of this paper is to examine the opportunities for the use of art as an educational resource to stimulate creativity in the teaching of Economics. The need to promote skill development to encourage reflection, critical analysis, imagination, interpretation of reality, the anticipation of change, the seeking of alternatives, etc. is essential in this area of knowledge. The analysis of the use of art as an educational tool through a classroom experience shows the opportunities offered by this approach, although the extent of its use in university education in non-artistic materials is still very low

Continuous symmetric Sobolev inner products

24 pages, no figures.-- MSC2000 codes: 42C05.MR#: MR1953647 (2003j:42029)Zbl#: Zbl pre05368623In this paper we consider the sequence of monic polynomials (Qn) orthogonal with respect to a symmetric Sobolev inner product. If Q_2n(x)=Pn(x^2) and Q_2n+1(x)=xRn(x^2), then we deduce the integral representation of the inner products such that (Pn) and (Rn) are, respectively, the corresponding sequences of monic orthogonal polynomials. In the semiclassical case, algebraic relations between such sequences are deduced. Finally, an application of the above results to Freud-Sobolev polynomials is given.The work of the second author was partially supported by Dirección General de Investigación (Ministerio de Ciencia y Tecnología) of Spain under grant BFM 2000-0206-C04-01 and INTAS project INTAS 2000-272.Publicad

Darboux transformation and perturbation of linear functionals

28 pages, no figures.-- MSC2000 codes: 42C05; 15A23.MR#: MR2055354 (2005b:15027)Zbl#: Zbl 1055.42016Let L be a quasi-definite linear functional defined on the linear space of polynomials with real coefficients. In the literature, three canonical transformations of this functional are studied: $\bold{xL}$, $\bold L+\bold C\delta (\bold x)$ and $\frac {1}{\bold x}\bold L +\bold C\delta(\bold x)$ where $\delta(x)$ denotes the linear functional $(\delta(x))(x )=\delta_{k,0}$, and $\delta_{k,0}$ is the Kronecker symbol. Let us consider the sequence of monic polynomials orthogonal with respect to L. This sequence satisfies a three-term recurrence relation whose coefficients are the entries of the so-called monic Jacobi matrix. In this paper we show how to find the monic Jacobi matrix associated with the three canonical perturbations in terms of the monic Jacobi matrix associated with L. The main tools are Darboux transformations. In the case that the LU factorization of the monic Jacobi matrix associated with xL does not exist and Darboux transformation does not work, we show how to obtain the monic Jacobi matrix associated with $\bold x \bold L$ as a limit case. We also study perturbations of the functional L that are obtained by combining the canonical cases. Finally, we present explicit algebraic relations between the polynomials orthogonal with respect to L and orthogonal with respect to the perturbed functionals.The work of the authors has been partially supported by Dirección General de Investigación (Ministerio de Ciencia y Tecnología) of Spain under grant BFM 2003-06335-C03-02 and NATO collaborative grant PST.CLG.979738.Publicad

Eigenvectors and minimal bases for some families of Fiedler-like linearizations

In this paper, we obtain formulas for the left and right eigenvectors and minimal bases of some families of Fiedler-like linearizations of square matrix polynomials. In particular, for the families of Fiedler pencils, generalized Fiedler pencils and Fiedler pencils with repetition. These formulas allow us to relate the eigenvectors and minimal bases of the linearizations with the ones of the polynomial. Since the eigenvectors appear in the standard formula of the condition number of eigenvalues of matrix polynomials, our results may be used to compare the condition numbers of eigenvalues of the linearizations within these families and the corresponding condition number of the polynomial eigenvalue problem.Publicad

Polynomial perturbations of bilinear functionals and Hessenberg matrices

20 pages, no figures.-- MSC2000 codes: 42C05; 15A23.MR#: MR2209234 (2008c:42024)Zbl#: Zbl 1134.42015This paper deals with symmetric and non-symmetric polynomial perturbations of symmetric quasi-definite bilinear functionals. We establish a relation between the Hessenberg matrices associated with the initial and the perturbed functionals using LU and QR factorizations. Moreover we give an explicit algebraic relation between the sequences of orthogonal polynomials associated with both functionals.The work of the authors has been partially supported by Dirección General de Investigación (Ministerio de Educacion y Ciencia) of Spain under Grant BFM 2003-06335-C03-02 and INTAS Research Network NeCCA INTAS 03-51-6637.Publicad

Comunicación familiar en el desarrollo del lenguaje oral de los niños de 4 a 5 años

El lenguaje oral es una de las competencias básicas que adquirirá el infante en el transcurso de cada etapa, existen varios factores cercanos a su entorno que condicionan este desarrollo, siendo la comunicación familiar uno de ellos. La presente investigación es de carácter cuantitativo con un nivel descriptivo-exploratorio. Tiene como objetivo analizar la importancia de la comunicación familiar en el desarrollo del lenguaje oral de los niños de 4 a 5 años de la Escuela de Educación Básica “Santa María de la Esperanza”. La muestra seleccionada fue de seis (6) docentes y 27 padres de familia. Para la recolección de datos fue necesario el uso de dos cuestionarios con escala de Likert, que determinaron el nivel de comunicación que existe en el grupo familiar y el nivel del lenguaje de los niños de las edades de 4 a 5 años según la perspectiva de los docentes. En cuanto a la validación del instrumento se lo realizó a través de criterios de expertos. Los análisis de los resultados se ejecutaron en el programa estadístico SPSS. La confiabilidad se consiguió mediante del alfa de Cronbach, con un 0,847 para primer instrumento y 0,785 para el segundo, que según su escala se considera aceptable. Los resultados obtenidos en las dimensiones de comunicación familiar dan como resultado una comunicación asertiva o abierta en los hogares de los niños entre las edades de 4 a 5 años y su nivel del lenguaje oral según la perspectiva de los docentes indican un nivel aceptable de acuerdo con su edad cronológica. Por lo cual, el estudio evidenció que una comunicación asertiva dentro del ámbito familiar contribuye en el infante al desarrollo apropiado del lenguaje oral

Analysis, design and experimental evaluation of connectivity management in heterogeneous wireless environments

Mención Internacional en el título de doctorThe future of network communications is mobile as many more users demand for ubiquitous connectivity. Wireless has become the primary access technology or even the only one, leading to an explosion in traffic demand. This challenges network providers to manage and configure new requirements without incrementing costs in the same amount. In addition to the growth in the use of mobile devices, there is a need to operate simultaneously different access technologies. As well, the great diversity of applications and the capabilities of mobile terminals makes possible for us to live in a hyper-connected world and offers new scenarios. This heterogeneity poses great challenges that need to be addressed to offer better performance and seamless experience to the final user. We need to orchestrate solutions to increase flexibility and empower interoperability. Connectivity management is handled from different angles. In the network stack, mobility is more easily handled by IP mobility protocols, since IP is the common layer between the different access technologies and the application diversity. From the end-user perspective, the connection manager is in charge of handling connectivity issues in mobile devices, but it is an unstandardized entity so its performance is heavily implementation-dependent. In this thesis we explore connectivity management from different angles. We study mobility protocols as they are part of our proposed solutions. In most of the cases we include an experimental evaluation of performance with 3G and IEEE 802.11 as the main technologies. We consider heterogeneous scenarios, with several access technologies where mobile devices have also several network interfaces. We evaluate how connectivity is handled as well as its influence in a handover. Based on the analysis of real traces from a cellular network, we confirm the suitability of more efficient mobility management. Moreover, we propose and evaluate three different solutions for providing mobility support in three different heterogeneous scenarios. We perform an experimental evaluation of a vehicular route optimization for network mobility, reporting on the challenges and lessons learned in such a complicated networking environment. We propose an architecture for supporting mobility and enhance handover in a passive optical network deployment. In addition, we design and deploy a mechanism for mobility management based on software-defined networking.Programa Oficial de Doctorado en Ingeniería TelemáticaPresidente: Arturo Azcorra Saloña.- Secretario: Ramón Agüero Calvo.- Vocal: Daniel Nunes Coruj