Cost-efficiencies, profitability, and strategic behavior: evidence from Japanese commercial banks

DOI 10.1108/17439130610646162Purpose - to examine whether Japanese commerical banks exhibited economies of scale and economies of density at the time when the mega-merger wave in Japanese banking began in the late 1990's. Since this merger wave has not yielded efficiencies, this analysis aims to shed light on whether banks, at the start of the wave, had reason to believe that larger banks would be more efficient

Exponential torsion growth for random 3-manifolds

We show that a random 3-manifold with positive first Betti number admits a tower of cyclic covers with exponential torsion growth

Maximum occupation number for composite boson states

One of the major differences between fermions and bosons is that fermionic states have a maximum occupation number of one, whereas the occupation number for bosonic states is in principle unlimited. For bosons that are made up of fermions, one could ask the question to what extent the Pauli principle for the constituent fermions would limit the boson occupation number. Intuitively one can expect the maximum occupation number to be proportional to the available volume for the bosons divided by the volume occupied by the fermions inside one boson, though a rigorous derivation of this result has not been given before. In this letter we show how the maximum occupation number can be calculated from the ground-state energy of a fermionic generalized pairing problem. A very accurate analytical estimate of this eigenvalue is derived. From that a general expression is obtained for the maximum occupation number of a composite boson state, based solely on the intrinsic fermionic structure of the bosons. The consequences for Bose-Einstein condensates of excitons in semiconductors and ultra cold trapped atoms are discussed.Comment: 4 pages, Revte

Prewetting transition on a weakly disordered substrate : evidence for a creeping film dynamics

We present the first microscopic images of the prewetting transition of a liquid film on a solid surface. Pictures of the local coverage map of a helium film on a cesium metal surface are taken while the temperature is raised through the transition. The film edge is found to advance at constant temperature by successive avalanches in a creep motion with a macroscopic correlation length. The creep velocity varies strongly in a narrow temperature range. The retreat motion is obtained only at much lower temperature, conforming to the strong hysteresis observed for prewetting transition on a disordered surface. Prewetting transition on such disordered surfaces appears to give rise to dynamical phenomena similar to what is observed for domain wall motions in 2D magnets.Comment: 7 pages, 3 figures, to be published in Euro.Phys.Let

Electronic transport coefficients from ab initio simulations and application to dense liquid hydrogen

Using Kubo's linear response theory, we derive expressions for the frequency-dependent electrical conductivity (Kubo-Greenwood formula), thermopower, and thermal conductivity in a strongly correlated electron system. These are evaluated within ab initio molecular dynamics simulations in order to study the thermoelectric transport coefficients in dense liquid hydrogen, especially near the nonmetal-to-metal transition region. We also observe significant deviations from the widely used Wiedemann-Franz law which is strictly valid only for degenerate systems and give an estimate for its valid scope of application towards lower densities

Devociones republicanas:los avatares de la comunidad política a principios del siglo XIX

El artículo muestra que la República fue una referencia central en el lenguaje político de los primeros años del siglo XIX. Articulando nuevos y viejos sentidos, la República permite discutir las posibilidades de un análisis que, dejando de lado la entrada nacional, rastree las formas de la comunidad política. Para ello, la primera parte del artículo muestra algunos de los problemas que tiene la nación como categoría de análisis de las primeras décadas del siglo XIX colombiano. La segunda sección inicia señalando la pluralidad de alternativas para nominar la comunidad política disponibles a principios del XIX –patria, nación, patria republicana– y explora en detalle el lugar privilegiado que la República ocupaba en tal panorama. Finalmente, la última parte retoma la preocupación por la República subrayando su particular carácter católico. El artículo termina insistiendo en que este recorrido abre posibilidades y nuevas preguntas para pensar en una historia de las formas e itinerarios de las comunidades políticas en el siglo XIX colombiano.The article shows that the Republic was a pivotal reference point in the political language of early nineteenth-century Colombia. By articulating old and new meanings, the Republic allows us to discuss the possibilities of an analysis that, leaving aside the nation as a privileged concept, follows the changing shape of the political community. The article first discusses some of the problems with the analytical category of nation as the privileged way to understand the post-revolutionary period. Next, it highlights the various options available at the start of the nineteenth century to refer to the political community–fatherland, nation, republican homeland– to then emphasize the centrality of republican invocations. In the third section, it shows how the idea of the Republic was pervaded by Catholic references. The article concludes by insisting how this case suggests new ways of thinking about the shape and trajectory of political communities in early nineteenth-century Colombia.O artigo mostra que a República foi uma referência central na linguagem dos primeiros anos do século XIX. Articulando novos e velhos sentidos, a República permite discutir as possibilidades de uma análise que, deixando de lado a abertura nacional, investigue as formas da comunidade política. Portanto, a primeira parte do artigo mostra alguns dos problemas que tem a nação como categoria de análise das primeiras décadas do século XIX colombiano. A segunda seção começa ressaltando a pluralidade de alternativas, para nomear a comunidade política, disponíveis no início do século XIX –pátria, nação, pátria republicana– e explora com detalhes o lugar privilegiado que a República ocupava em tal panorama. Finalmente, a última parte retoma a preocupação pela República destacando seu particular caráter católico. O artigo termina insistindo que esta ocorrido abre possibilidades e novas perguntas para pensar em uma história das formas e itinerários das comunidades políticas no século XIX colombiano

Hydrodynamic object recognition using pressure sensing

Hydrodynamic sensing is instrumental to fish and some amphibians. It also represents, for underwater vehicles, an alternative way of sensing the fluid environment when visual and acoustic sensing are limited. To assess the effectiveness of hydrodynamic sensing and gain insight into its capabilities and limitations, we investigated the forward and inverse problem of detection and identification, using the hydrodynamic pressure in the neighbourhood, of a stationary obstacle described using a general shape representation. Based on conformal mapping and a general normalization procedure, our obstacle representation accounts for all specific features of progressive perceptual hydrodynamic imaging reported experimentally. Size, location and shape are encoded separately. The shape representation rests upon an asymptotic series which embodies the progressive character of hydrodynamic imaging through pressure sensing. A dynamic filtering method is used to invert noisy nonlinear pressure signals for the shape parameters. The results highlight the dependence of the sensitivity of hydrodynamic sensing not only on the relative distance to the disturbance but also its bearing

Roll-to-roll manufacturing of micropatterned adhesives by template compression

For the next generation of handling systems, reversible adhesion enabled by micropatterned dry adhesives exhibits high potential. The versatility of polymeric micropatterns in handling objects made from various materials has been demonstrated by several groups. However, specimens reported in most studies have been restricted to the laboratory scale. Upscaling the size and quantity of micropatterned adhesives is the next step to enable successful technology transfer. Towards this aim, we introduce a continuous roll-to-roll replication process for fabrication of high-performance, mushroom-shaped micropatterned dry adhesives. The micropatterns were made from UV-curable polyurethane acrylates. To ensure the integrity of the complex structure during the fabrication process, flexible templates were used. The compression between the template and the wet prepolymer coating was investigated to optimize replication results without structural failures, and hence, to improve adhesion. As a result, we obtained micropatterned adhesive tapes, 10 cm in width and several meters in length, with adhesion strength about 250 kPa to glass, suitable for a wide range of applications. © 2018 by the authors

Excitonic condensate and quasiparticle transport in electron-hole bilayer systems

Bilayer electron-hole systems undergo excitonic condensation when the distance d between the layers is smaller than the typical distance between particles within a layer. All excitons in this condensate have a fixed dipole moment which points perpendicular to the layers, and therefore this condensate of dipoles couples to external electromagnetic fields. We study the transport properties of this dipolar condensate system based on a phenomenological model which takes into account contributions from the condensate and quasiparticles. We discuss, in particular, the drag and counterflow transport, in-plane Josephson effect, and noise in the in-plane currents in the condensate state which provides a direct measure of the superfluid collective-mode velocity.Comment: 7 pages, 3 figure

Deterministic Partial Differential Equation Model for Dose Calculation in Electron Radiotherapy

Treatment with high energy ionizing radiation is one of the main methods in modern cancer therapy that is in clinical use. During the last decades, two main approaches to dose calculation were used, Monte Carlo simulations and semi-empirical models based on Fermi-Eyges theory. A third way to dose calculation has only recently attracted attention in the medical physics community. This approach is based on the deterministic kinetic equations of radiative transfer. Starting from these, we derive a macroscopic partial differential equation model for electron transport in tissue. This model involves an angular closure in the phase space. It is exact for the free-streaming and the isotropic regime. We solve it numerically by a newly developed HLLC scheme based on [BerCharDub], that exactly preserves key properties of the analytical solution on the discrete level. Several numerical results for test cases from the medical physics literature are presented.Comment: 20 pages, 7 figure