715 research outputs found
La Intervención Judicial de los Estados como Detractor del Arbitraje Comercial Internacional.
El presente trabajo de investigación y tesis, pretende hacer un análisis sobre la intervención judicial de los Estados en los casos de arbitraje comercial internacional, y con esto tratar de concluir si dichas intervenciones actúan como detractor del arbitraje comercial internacional
On the existence of pure strategy equilibria in large generalized games with atomic players
We consider a game with a continuum of players where only a finite number of them are atomic. Objective functions and admissible strategies may depend on the actions chosen by atomic players and on aggregate information about the actions chosen by non-atomic players. Only atomic players are required to have convex sets of admissible strategies and quasi-concave objective functions. We prove the existence of a pure strategy Nash equilibria. Thus, we extend to large generalized games with atomic players the results of equilibrium existence for non-atomic games of Schemeidler (1973) and Rath (1992). We do not obtain a pure strategy equilibrium by purification of mixed strategy equilibria. Thus, we have a direct proof of both Balder (1999, Theorem 2.1) and Balder (2002, Theorem 2.2.1), for the case where non-atomic players have a common non-empty set of strategies and integrable bounded codification of action profiles. Our main result is readily applicable to many interesting problems in general equilibrium. As an application, we extend Aumann (1966) result on the existence of equilibrium with a continuum of traders to a standard general equilibrium model with incomplete asset markets.Generalized games; Non-convexities; Pure-strategy Nash equilibrium
Interfacial depinning transitions in disordered media: revisiting an old puzzle
Interfaces advancing through random media represent a number of different
problems in physics, biology and other disciplines. Here, we study the
pinning/depinning transition of the prototypical non-equilibrium interfacial
model, i.e. the Kardar-Parisi-Zhang equation, advancing in a disordered medium.
We analyze separately the cases of positive and negative non-linearity
coefficients, which are believed to exhibit qualitatively different behavior:
the positive case shows a continuous transition that can be related to
directed-percolation-depinning while in the negative case there is a
discontinuous transition and faceted interfaces appear. Some studies have
argued from different perspectives that both cases share the same universal
behavior. Here, by using a number of computational and scaling techniques we
shed light on this puzzling situation and conclude that the two cases are
intrinsically different.Comment: 13 pages, 9 figure
Multi-scale Laplacian community detection in heterogeneous networks
Heterogeneous and complex networks represent the intertwined interactions
between real-world elements or agents. A fundamental problem of complex network
theory involves finding inherent partitions, clusters, or communities. By
taking advantage of the recent Laplacian Renormalization Group approach, we
scrutinize information diffusion pathways throughout networks to shed further
light on this issue. Based on inter-node communicability, our definition
provides a unifying framework for multiple partitioning measures: multi-scale
Laplacian (MSL) community detection algorithm. This new framework permits to
introduce a scale-dependent optimal partition in communities and to determine
the existence of a particular class of nodes, called metastable nodes, that
switching community at different scales are expected to play a central role in
the communication between different communities and, therefore in the control
of the whole network.Comment: 14 pages, 12 figure
Characterizing spatial point processes by percolation transitions
A set of discrete individual points located in an embedding continuum space
can be seen as percolating or non-percolating, depending on the radius of the
discs/spheres associated with each of them. This problem is relevant in
theoretical ecology to analyze, e.g., the spatial percolation of a tree species
in a tropical forest or a savanna. Here, we revisit the problem of aggregating
random points in continuum systems (from to dimensional Euclidean
spaces) to analyze the nature of the corresponding percolation transition in
spatial point processes. This problem finds a natural description in terms of
the canonical ensemble but not in the usual grand-canonical one, customarily
employed to describe percolation transitions. This leads us to analyze the
question of ensemble equivalence and study whether the resulting canonical
continuum percolation transition shares its universal properties with standard
percolation transitions, analyzing diverse homogeneous and heterogeneous
spatial point processes. We, therefore, provide a powerful tool to characterize
and classify a vast class of natural point patterns, revealing their
fundamental properties based on percolation phase transitions.Comment: 22 pages, 13 figure
Laplacian renormalization group for heterogeneous networks
The renormalization group is the cornerstone of the modern theory of
universality and phase transitions and it is a powerful tool to scrutinize
symmetries and organizational scales in dynamical systems. However, its
application to complex networks has proven particularly challenging, owing
to correlations between intertwined scales. To date, existing approaches
have been based on hidden geometries hypotheses, which rely on the
embedding of complex networks into underlying hidden metric spaces.
Here we propose a Laplacian renormalization group diffusion-based picture
for complex networks, which is able to identify proper spatiotemporal scales
in heterogeneous networks. In analogy with real-space renormalization
group procedures, we first introduce the concept of Kadanoff supernodes
as block nodes across multiple scales, which helps to overcome detrimental
small-world effects that are responsible for cross-scale correlations. We
then rigorously define the momentum space procedure to progressively
integrate out fast diffusion modes and generate coarse-grained graphs. We
validate the method through application to several real-world networks,
demonstrating its ability to perform network reduction keeping crucial
properties of the systems intact
Evolution in the Debian GNU/Linux software network : analogies and differences with gene regulatory networks
Biological networks exhibit intricate architectures deemed to be crucial for their functionality. In particular, gene regulatory networks, which play a key role in information processing in the cell, display non-trivial architectural features such as scale-free degree distributions, high modularity and low average distance between connected genes. Such networks result from complex evolutionary and adaptive processes difficult to track down empirically. On the other hand, there exists detailed information on the developmental (or evolutionary) stages of open-software networks that result from self-organized growth across versions. Here, we study the evolution of the Debian GNU/Linux software network, focusing on the changes of key structural and statistical features over time. Our results show that evolution has led to a network structure in which the out-degree distribution is scale-free and the in-degree distribution is a stretched exponential. In addition, while modularity, directionality of information flow, and average distance between elements grew, vulnerability decreased over time. These features resemble closely those currently shown by gene regulatory networks, suggesting the existence of common adaptive pathways for the architectural design of information-processing networks. Differences in other hierarchical aspects point to system-specific solutions to similar evolutionary challenges
Embryo development in Carica papaya Linn
Proyecto interdisciplinarioPapaya (Carica papaya Linn.) is a tropical plant whose draft genome has been sequenced. Papaya produces large fruits rich in vitamins A and C and is an important cash crop in developing countries. Nonetheless, little is known about how the female gametophyte develops, how it is fertilized and how it develops into a mature seed containing an embryo and an endosperm. The Papaya female gametophyte displays a Polygonum-type architecture consisting of two synergid cells, an egg cell, a central cell, and three antipodal cells. Reports are available of the presumed existence of varieties in which cross fertilization is bypassed and autonomous development of embryos occurs (e.g., apomixis). In this study, we analyzed the development of female gametophytes in a commercial Hawaiian parental line and in the presumed apomictic Costa Rican line L1. Samples were collected before and after anthesis to compare the overall structure, size and transcriptional patterns of several genes that may be involved in egg and endosperm cell fate and proliferation. These genes were the putative papaya homologs of ARGONAUTE9 (AGO9), MEDEA (MEA), RETINOBLASTOMA RELATED-1 (RBR1), and SLOW WALKER-1 (SWA1). Our results suggest that its feasible to identify the contour of structural features of Polygonum-type development, and that in bagged female flowers of line L1 we might have observed autonomous development of embryo-like structures. Possible downregulation of papaya homologs for AGO9, MEA, RBR1 and SWA1 was observed in embryo sacs from line L1 before and after anthesis, which may suggest a tentative link between suspected apomixis and transcriptional downregulation of genes for RNA-directed DNA methylation, histone remodelers, and rRNA processing. Most notably, the large size of the papaya embryo sac suggests that it could be a cytological alternative to Arabidopsis thaliana for study. Significant variation in embryo sac size was observed between the varieties under study, suggesting wide differences in the genetic regulation of anatomical features.Universidad de Costa Rica/[736-B5-A13]/UCR/Costa RicaUCR::VicerrectorÃa de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental AgrÃcola Fabio Baudrit Moreno (EEAFBM)UCR::VicerrectorÃa de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de BiologÃaUCR::VicerrectorÃa de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::JardÃn Botánico Lankester (JBL
Fundación de una aerolÃnea
En un mundo cada vez más global, en el que el interés de la gente por conocer todos los rincones del planeta va en aumento, es primordial tener los medios necesarios para satisfacerlo.Este proyecto,por tanto,nace con la idea de generar una oportunidad de negocio que pongalos medios necesarios para facilitar la movilidadde las personas,y asà poder dar satisfacciónalagente.En la primera parte del trabajo se realiza un análisis global del transporte aéreo, viendo los distintos modelos degestión aeroportuaria y la evolución del tráfico aéreo. Asà como numerosas definiciones útiles para la comprensión del trabajo.A continuación,se detallalaaerolÃnea y sus requisitos generales y especÃficos. Descripción del modelo de negocio Low Cost. Estudio y selección de la base de operaciones y punto de destino, dando lugar al trayecto Barcelona-Nueva Delhi. Estudio y selección de la ruta adecuada BCN-DHL. Selección de la aeronave para dar servicio en dicha rutay fuentes de ingresos y costes de la compañÃa.Finalmente se realiza un plan financieropara evaluar su viabilidad
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