Nonlinear Dynamic in the Chilean Stock Market: Evidence from Returns and Trading Volume

In this paper we investigate the possible presence of nonlinear dynamics for stock index returns and trading volume at the Chilean Stock Market. To capture any nonlinear behavior in the series we estimate Smooth Transition Autoregressive (STAR) models and test them against the linear alternatives. As a complement to this univariate approach, we use Markov-Switching Vector Autoregressive (MS-VAR) models to investigate the empirical relationship between both variables. The results clearly show that the Chilean Stock Market is characterized by the presence of nonlinear patters in both series (trading volume and stock returns) as well as in their joint relationship. The presence of nonlinearities is a key issue in testing the Efficient Market Hypothesis (EMH), according to which stock returns and trading volume should be not related. Previous researches on the efficiency using data from the Chilean stock market, using linear models, support the hypothesis. However, the nonlinear patters we found in the data are a clear signal of misspecification problems in a testing procedure based on a linear approach.

Black-hole horizons as probes of black-hole dynamics II: geometrical insights

In a companion paper [1], we have presented a cross-correlation approach to near-horizon physics in which bulk dynamics is probed through the correlation of quantities defined at inner and outer spacetime hypersurfaces acting as test screens. More specifically, dynamical horizons provide appropriate inner screens in a 3+1 setting and, in this context, we have shown that an effective-curvature vector measured at the common horizon produced in a head-on collision merger can be correlated with the flux of linear Bondi-momentum at null infinity. In this paper we provide a more sound geometric basis to this picture. First, we show that a rigidity property of dynamical horizons, namely foliation uniqueness, leads to a preferred class of null tetrads and Weyl scalars on these hypersurfaces. Second, we identify a heuristic horizon news-like function, depending only on the geometry of spatial sections of the horizon. Fluxes constructed from this function offer refined geometric quantities to be correlated with Bondi fluxes at infinity, as well as a contact with the discussion of quasi-local 4-momentum on dynamical horizons. Third, we highlight the importance of tracking the internal horizon dual to the apparent horizon in spatial 3-slices when integrating fluxes along the horizon. Finally, we discuss the link between the dissipation of the non-stationary part of the horizon's geometry with the viscous-fluid analogy for black holes, introducing a geometric prescription for a "slowness parameter" in black-hole recoil dynamics.Comment: Final version published on PR

Non-linear Dynamics in the Chilean Stock Market: Evidence on Traded Volumes and Returns

In this paper we investigate the possible presence of nonlinear dynamics for stock index returns and trading volume in the Chilean stock market. To capture any nonlinear behavior of the series we estimate smooth transition autoregressive (STAR) models and then test them against the linear alternatives. As a complement to this univariate approach, we use Markov-Switching Vector Autoregressive (MS-VAR) models to investigate the empirical relationship between both variables. The results clearly show that the Chilean Stock Market is characterized by the presence of nonlinear patterns in both series (trading volume and stock returns) as well as in their joint relationship. The presence of nonlinearities is a key issue in testing the Efficient Market Hypothesis (EMH), according to which stock returns and trading volume should not be related. Previous research on the efficiency using data from the Chilean stock market, based on linear models, support the hypothesis. However, the nonlinear patters found in the data are a clear signal of misspecification problems in a testing procedure based on a linear approach.

Socio-economic development plans and the quality of education in Colombia

RESUMEN: El presente texto es una reflexión que se inscribe dentro de los análisis de los léxicos dominantes en la educación superior colombiana entre 1993 y 2012, con los cuales se anuncia un cambio de énfasis en la valoración social de la educación en su conjunto. Se parte de una descripción de la relación entre la sociedad y la educación y se insinúan las variaciones sufridas por esta última en las concepciones de las personas y su importancia social. Se toman como referencia los planes de desarrollo económico y social en Colombia para el período estudiado y se muestran cómo son explícitos y enfáticos los lenguajes alusivos a la educación como mercancía. En especial, se reconoce un viraje en el contexto de la educación superior hacia expresiones como eficiencia, eficacia, competencia, desarrollo, productividad, competitividad, mercado mundial, estandarización, crédito, mejoramiento de la calidad, autosostenibilidad, entre otros.ABSTARCT: The reflection outlined in this text makes part of the predominant lexical analysis in Colombian higher education between 1993 and 2012, which predicts a change of emphasis in the social value of education as a whole. It starts with a description of the relationship between society and education as well as the changes the latter has undergone in terms of people’s conceptions about it and its importance for society. The referential context is the socio-economic development plans in Colombia during the period under study in order to show that the language used to refer to education is clearly emphatic when alluding to it as a commodity. In particular, this article recognizes a shift in the context of higher education towards expressions such as efficiency, effectiveness, competition, development, productivity, competitiveness, global market, standardization, credit, quality improvement, self-sustainability, to name only a few

Variability-Aware Design of Subthreshold Devices

Over the last 10 years, digital subthreshold logic circuits have been developed for applications in the ultra-low power design domain, where performance is not the priority. Recently, devices optimized for subthreshold operation have been introduced as potential construction blocks. However, for these devices, a strong sensitivity to process variations is expected due to the exponential relationship of the subthreshold drive current and the threshold voltage. In this thesis, a yield optimization technique is proposed to suppress the variability of a device optimized for subthreshold operation. The goal of this technique is to construct and inscribe a maximum yield cube in the 3-D feasible region composed of oxide thickness, gate length, and channel doping concentration. The center of this cube is chosen as the maximum yield design point with the highest immunity against variations. By using the technique, a transistor is optimized for subthreshold operation in terms of the desired total leakage current and intrinsic delay bounds. To develop the concept of the technique, sample devices are designed for 90nm and 65nm technologies. Monte Carlo simulations verify the accuracy of the technique for meeting power and delay constraints under technology-specific variances of the design parameters of the device

Políticas públicas y profesión docente

Es inobjetable afirmar que la educación colombiana ha obtenido avances significativos en los últimos quince años a la luz de los indicadores predominantes de la calidad, pero a la vez, es necesario señalar que en ese mismo lapso la profesión docente se ha visto afectada negativamente. Particularmente se hace consideración a lo que reglamentó la Ley  115 de 1994 y que ha dejado de ponerse en práctica; se señalan algunos inconvenientes generados con la ejecución de la misma, las formas y los procedimientos en los concursos docentes, la invisibilización de las instituciones formadoras de maestros y los retrocesos en la cultura evaluativa instituciona

Políticas públicas y profesión docente

Es inobjetable afirmar que la educación colombiana ha obtenido avances significativos en los últimos quince años a la luz de los indicadores predominantes de la calidad, pero a la vez, es necesario señalar que en ese mismo lapso la profesión docente se ha visto afectada negativamente. Particularmente se hace consideración a lo que reglamentó la Ley  115 de 1994 y que ha dejado de ponerse en práctica; se señalan algunos inconvenientes generados con la ejecución de la misma, las formas y los procedimientos en los concursos docentes, la invisibilización de las instituciones formadoras de maestros y los retrocesos en la cultura evaluativa instituciona

Políticas públicas y profesión docente

RESUMEN: Es inobjetable afirmar que la educación colombiana ha obtenido avances significativos en los últimos quince años a la luz de los indicadores predominantes de la calidad, pero a la vez, es necesario señalar que en ese mismo lapso la profesión docente se ha visto afectada negativamente. Particularmente se hace consideración a lo que reglamentó la Ley 115 de 1994 y que ha dejado de ponerse en práctica; se señalan algunos inconvenientes generados con la ejecución de la misma, las formas y los procedimientos en los concursos docentes, la invisibilización de las instituciones formadoras de maestros y los retrocesos en la cultura evaluativa institucional.ABSTARCT: According to the predominant quality indicators it is undoubtedly that education in Colombia has obtained important developments during the last fifteen years; however, it is important to point out that over the same period the teaching profession has been affected negatively. In respect to the provisions of the Law 115 (1994) which have not been fully met, this paper addresses some of the obstacles in the compliance of such law, and some others related for example, to the forms and procedures followed by the government for the opening of teachers' positions, to other professions, the ignorance towards the institutions where teachers are trained and the way the institutional evaluation culture has been drawn back

La formación investigativa de los maestros : un asunto estratégico para la alta calidad

RESUMEN: El artículo tiene como propósito principal hacer evidente la importancia estratégica de la investigación en el desempeño profesional de los nuevos maestros. El tema comienza desarrollándose en el contexto de las organizaciones educativas colombianas en todos sus niveles, a partir de un plan estratégico de alta calidad. La formación investigativa se ha constituido en condición necesaria para el logro de la excelencia del maestro. El plan estratégico de alta calidad en torno a lo investigativo, hace relación a algunas generalidades conceptuales, y plantea la alternativa del plan de desarrollo investigativo, como estrategia de gestión a nivel de los procesos institucionales en que tiene cabida la articulación de los proyectos de aula, de los proyectos de núcleos y otros ámbitos definidos al interior de los proyectos educativos institucionales. Se presenta una propuesta del desarrollo de una cultura investigativa y se pone como ejemplo el papel que hasta el momento ha jugado el referente investigativo en los procesos de acreditación institucional, específicamente en las instituciones formadoras de maestros.ABSTARCT: The main objective of this article is to stress the strategic importance that research has in the teaching practice of new teachers. The article starts within the context of the educational organizations around Colombia, based on a strategic plan of high quality. Research oriented education has become a necessary condition for excellence in teaching. The strategic plan for high quality refers to some general concepts and to a plan for research development as an strategy for the administration of the institutional processes for articulating classroom projects, an other institutional spaces. The article finishes with a proposal for developing a research culture and presents, as an example, the role played by research processes in institutional accreditation of teachers’ schools