Kipus: revista andina de letras. 11 (Reseñas)

Presenta las reseñas de los siguientes libros: Marcelo Báez, TIERRA DE NADIA, Quito: Libresa, 2000; 106 pp. -- Byron Rodríguez, BESTIARIO DE CENIZAS, 2a. ed., Quito: Eskeletra, 1999. -- Viviana Cordero, EL TEATRO DE LOS MONSTRUOS, Quito: coedición Libresa / B@ezOquendo, 2000; 310 pp. -- Fernando Cruz Kronfly, LA CARAVANA DE GARDEL. -- Jorge Dávila Vázquez, CÉSAR DÁVILA ANDRADE, COMBATE POÉTICO Y SUICIDIO, Cuenca: Universidad de Cuenca, 1999; 348 pp. -- Euler Granda, QUE TRATA DE UNOS GATOS, Quito: Casa de la Cultura Ecuatoriana, 1999. -- Edgar Freire, El BARRIO DE lOS PRODIGIOS (MEMORIAS DE UN NIÑO), Quito: Libresa, 1999; 178 pp. -- Jostein Gaarder, VITA BREVIS, Madrid: Siruela, 1997; 130 pp. -- Michael Handelsman, Lo AFRO Y LA PLURINACIONALIDAD: EL CASO ECUATORIANO VISTO DESDE SU LITERATURA, Mississippi: University of Mississippi, 1999; 196 pp. -- Iván Oñate, LA NADA SAGRADA, Quito: Eskeletra, 1999. -- Jorge Volpi, EN BUSCA DE KLINGSOR, Barcelona: Seix Barral, 1999. -- Rosa Montero, LA HLJA DEL CANÍBAL, Bogotá: Espasa, 1998; 338 pp. -- María E. Moscoso, LA CANCIÓN DE ROKOLA, Quito: El Conejo, 1999. -- Kenzaburo Oé, DINOS CÓMO SOBREVIVIR A NUESTRA LOCURA Barcelona: Anagrama, 1995. -- Pablo Rocca, compilador, PÁGINAS DE GUERRA (1806-1935), Montevideo: Banda Oriental, 1995; 87 pp. -- Javier Ponce, RESÍGNATE A PERDER, Quito: Seix Barral. 1998; 135 pp. -- Eduardo Rosenzvaig, LA CEPA. ARQUEOLOGÍA DE UNA CULTURA AZUCARERA, Buenos Aires: Universidad Nacional de Tucumán / Ediciones Letra Buena, 1999; tomo III, 608 pp. -- Abdón Ubidia, REFERENTES. ENSAYOS, Quito: El Conejo / UASB / Abya-Yala, 2000; 195 pp.

Estudio de recepción sobre la identidad nacional en el cine ecuatoriano en dos barrios de Quito

La tradición de los estudios de recepción en América Latina y en Ecuador se ha enfocado primordialmente en dos vías: los medios masivos como prensa, radio y televisión, éste último el más frecuente; y en los emisores y los contenidos que transmiten esos mensajes. El ojo en las audiencias, en los espectadores y públicos tiene un recorrido menor desde las ciencias sociales, situación que se agrava en el campo de los estudios de cine. En esa medida este trabajo abona para comprender las lecturas que los públicos de Quito hacen de las representaciones de la identidad nacional en el cine ecuatoriano. El planteamiento es estudiar en dos sectores socio-demográficamente distintos de Quito los consumos culturales, las mediaciones que intervienen y las matrices culturales que los constituyen, para comprender las significaciones que hacen alrededor de la identidad a partir de la recepción del cine ecuatoriano. Para ello las corrientes teóricas de Nestor García Canclini y Guillermo Orozco Gómez son los principales anclajes que encaminan un estudio que además pone en cuestionamiento ese repetido criterio de que el público ecuatoriano quiere verse en el cine nacional. Para sostener el estudio de recepción primero se plantea un marco teórico que problematiza a la recepción cinematográfica en relación con los públicos heterogéneos. Es una recepción que revaloriza el papel del perceptor de los textos, para este caso, las obras cinematográgicas. Se ubica a la recepción como una actividad, como un acto de producción de significaciones y dentro de un continuo proceso que resemantiza las propuestas de las películas. En el segundo capítulo se problematiza el concepto de la identidad nacional y se asume la línea de García Canclini sobre las multi-identidades, para acoplarlo en relación con la recepción de estas identidades en el cine ecuatoriano, para lo cual además de brinda un mapeo del cine local. En el tercer y último capítulo se analizan los resultados de la investigación de campo que estudió los sectores de La Loma Grande y el conjunto Jardines de Carcelén, exponiendo sus miradas críticas sobre las representaciones de identidad nacional que plantean las películas ecuatorianas, hecho que incluso explica en parte el por qué la gente no va a ver cine nacional.

A cell by cell anisotropic adaptive mesh ALE method

A cell by cell anisotropic adaptive mesh Arbitrary Lagrangian Eulerian (ALE) method for the solution of the Euler equations is described. An efficient approach to equipotential mesh relaxation on anisotropically refined meshes is developed. Results for two test problems are presented.

Perturbed Rankine vortices in surface quasi-geostrophic dynamics

An analytical dispersion relation is derived for linear perturbations to a Rankine vortex governed by surface quasi-geostrophic dynamics. Such a Rankine vortex is a circular region of uniform anomalous surface temperature evolving under quasi-geostrophic dynamics with uniform interior potential vorticity. The dispersion relation is analysed in detail and compared to the more familiar dispersion relation for a perturbed Rankine vortex governed by the Euler equations. The results are successfully verified against numerical simulations of the full equations. The dispersion relation is relevant to problems including wave propagation on surface temperature fronts and the stability of vortices in quasi-geostrophic turbulence.

An efficient flux difference splitting algorithm for unsteady duct flows of a real gas

A numerical scheme is presented for the solution of the Euler equations of compressible flow of a real gas in a single spatial coordinate. This includes flow in a duct of variable cross-section, as well as flow with slab, cylindrical or spherical symmetry, as well as the case of an ideal gas, and can be useful when testing codes for the two-dimensional equations governing compressible flow of a real gas. The resulting scheme requires an average of the flow variables across the interface between cells, and this average is chosen to be the arithmetic mean for computational efficiency, which is in contrast to the usual “square root” averages found in this type of scheme. The scheme is applied with success to five problems with either slab or cylindrical symmetry and for a number of equations of state. The results compare favourably with the results from other schemes.

An efficient numerical method for compressible flows of a real gas using arithmetic averaging

An efficient numerical method is presented for the solution of the Euler equations governing the compressible flow of a real gas. The scheme is based on the approximate solution of a specially constructed set of linearised Riemann problems. An average of the flow variables across the interface between cells is required, and this is chosen to be the arithmetic mean for computational efficiency, which is in contrast to the usual square root averaging. The scheme is applied to a test problem for five different equations of state.

An efficient shock capturing scheme for the pseudo-unsteady equations representing steady inviscid flow

An efficient algorithm is presented for the solution of the steady Euler equations of gas dynamics. The scheme is based on solving linearised Riemann problems approximately and in more than one dimension incorporates operator splitting. The scheme is applied to a standard test problem of flow down a channel containing a circular arc bump for three different mesh sizes.

An efficient shock capturing algorithm for compressible flows in a duct of variable cross-section

A numerical scheme is presented for the solution of the Euler equations of compressible flow of a gas in a single spatial co-ordinate. This includes flow in a duct of variable cross-section as well as flow with slab, cylindrical or spherical symmetry and can prove useful when testing codes for the two-dimensional equations governing compressible flow of a gas. The resulting scheme requires an average of the flow variables across the interface between cells and for computational efficiency this average is chosen to be the arithmetic mean, which is in contrast to the usual ‘square root’ averages found in this type of scheme. The scheme is applied with success to five problems with either slab or cylindrical symmetry and a comparison is made in the cylindrical case with results from a two-dimensional problem with no sources.

A non-uniform mesh scheme for compressible flow

A non-uniform mesh scheme is presented for the computation of compressible flows governed by the Euler equations of gas dynamics. The scheme is based on flux-difference splitting and represents an extension of a similar scheme designed for uniform meshes. The numerical results demonstrate that little, if any, spurious oscillation occurs as a result of the non-uniformity of the mesh; and importantly, shock speeds are computed correctly.

An efficient Riemann solver for unsteady flows with non-ideal gases

A Riemann solver is presented for the Euler equations of gas dynamics with real gases. This represents a more efficient version of an algorithm originally presented by the author.

Real gas flows in a duct

A numerical scheme is presented for the solution of the Euler equations of compressible flow of a real gas in a single spatial coordinate. This include flow in a duct of variable cross-section as well as flow with cylindrical or spherical symmetry, and can prove useful when testing codes for the two-dimensional equations governing compressible flow of a real gas. The scheme is applied with success to a problem involving the interaction of converging and diverging cylindrical shocks for four equations of state and to a problem involving the reflection of a converging shock.

Riemann solvers with primitive parameter vectors for two-dimensional compressible flows of a real gas

An analysis of averaging procedures is presented for an approximate Riemann solver for the equations governing the compressible flow of a real gas. This study extends earlier work for the Euler equations with ideal gases.

Numerical computation of an analytic singular value decomposition of a matrix valued function

This paper extends the singular value decomposition to a path of matricesE(t). An analytic singular value decomposition of a path of matricesE(t) is an analytic path of factorizationsE(t)=X(t)S(t)Y(t) T whereX(t) andY(t) are orthogonal andS(t) is diagonal. To maintain differentiability the diagonal entries ofS(t) are allowed to be either positive or negative and to appear in any order. This paper investigates existence and uniqueness of analytic SVD's and develops an algorithm for computing them. We show that a real analytic pathE(t) always admits a real analytic SVD, a full-rank, smooth pathE(t) with distinct singular values admits a smooth SVD. We derive a differential equation for the left factor, develop Euler-like and extrapolated Euler-like numerical methods for approximating an analytic SVD and prove that the Euler-like method converges.

Correlations between two sets of angular relation equations

It is shown here that the angular relation equations between direct and reciprocal vectors are very similar to the angular relation equations in Euler's theorem. These two sets of equations are usually treated separately as unrelated equations in different fields. In this careful study, the connection between the two sets of angular equations is revealed by considering the cosine rule for the spherical triangle. It is found that understanding of the correlation is hindered by the facts that the same variables are defined differently and different symbols are used to represent them in the two fields. Understanding the connection between different concepts is not only stimulating and beneficial, but also a fundamental tool in innovation and research, and has historical significance. The background of the work presented here contains elements of many scientific disciplines. This work illustrates the common ground of two theories usually considered separately and is therefore of benefit not only for its own sake but also to illustrate a general principle that a theory relevant to one discipline can often be used in another. The paper works with chemistry related concepts using mathematical methodologies unfamiliar to the usual audience of mainstream experimental and theoretical chemists.

Symmetric stability of compressible zonal flows on a generalized equatorial β plane

Sufficient conditions are derived for the linear stability with respect to zonally symmetric perturbations of a steady zonal solution to the nonhydrostatic compressible Euler equations on an equatorial � plane, including a leading order representation of the Coriolis force terms due to the poleward component of the planetary rotation vector. A version of the energy–Casimir method of stability proof is applied: an invariant functional of the Euler equations linearized about the equilibrium zonal flow is found, and positive definiteness of the functional is shown to imply linear stability of the equilibrium. It is shown that an equilibrium is stable if the potential vorticity has the same sign as latitude and the Rayleigh centrifugal stability condition that absolute angular momentum increase toward the equator on surfaces of constant pressure is satisfied. The result generalizes earlier results for hydrostatic and incompressible systems and for systems that do not account for the nontraditional Coriolis force terms. The stability of particular equilibrium zonal velocity, entropy, and density fields is assessed. A notable case in which the effect of the nontraditional Coriolis force is decisive is the instability of an angular momentum profile that decreases away from the equator but is flatter than quadratic in latitude, despite its satisfying both the centrifugal and convective stability conditions.