Market Efficiency and price discovery relationships between spot, futures and forward prices: The case of the Iberian Electricity Market (MIBEL)

This paper analyses the relationships between prices from three different markets within the Spanish zone of the Iberian Electricity Market (MIBEL), namely futures, spot and over the counter (OTC) forward markets. The study focuses on three items: (i) contrasting the Weak-form efficiency hypothesis of the markets involved in the study, (ii) analysing the Semi-strong-form efficient market hypothesis (EMH) of the MIBEL futures market and (iii) examining the price discovery relationships between the series of prices of the considered markets. The empirical results confirm that 1-month-, 1-quarter-, 1-year-ahead futures and spot markets satisfy, generally, the Weak-form efficiency hypothesis and that MIBEL futures market does not contradict the EMH in its Semi-strong-form. In addition, price discovery relationships have also been found. In particular, there is unidirectional causality from the futures market to the forward market and from the futures market to the spot market for 1-month- and 1-quarter-ahead maturities. This result may be indicative of the agents to use the price of the futures market as a valuable reference

Action recognition using the Rf Transform on optical flow images

The objective of this paper is the automatic recognition of human actions in video sequences. The use of spatio-temporal features for action recognition has become very popular in recent literature Instead of extracting the spatio-temporal features from the raw video sequence, some authors propose to project the sequence to a single template first. As a contribution we propose the use of several variants of the R transform for projecting the image sequences to templates. The R transform projects the whole sequence to a single image, retaining information concerning movement direction and magnitude. Spatio-temporal features are extracted from the template, they are combined using a bag of words paradigm, and finally fed to a SVM for action classification. The method presented is shown to improve the state-of-art results on the standard Weizmann action datasetPeer ReviewedPostprint (published version

Temporal segmentation of human actions in video sequences

Most of the published works concerning action recognition, usually assume that the action sequences have been previously segmented in time, that is, the action to be recognized starts with the first sequence frame and ends with the last one. However, temporal segmentation of actions in sequences is not an easy task, and is always prone to errors. In this paper, we present a new technique to automatically extract human actions from a video sequence. Our approach presents several contributions. First of all, we use a projection template scheme and find spatio-temporal features and descriptors within the projected surface, rather than extracting them in the whole sequence. For projecting the sequence we use a variant of the R transform, which has never been used before for temporal action segmentation. Instead of projecting the original video sequence, we project its optical flow components, preserving important information about action motion. We test our method on a publicly available action dataset, and the results show that it performs very well segmenting human actions compared with the state-of-the-art methods.Peer ReviewedPostprint (author's final draft

La reflexión de una maestra de Matemáticas en el "Prácticum" y en los inicios de su práctica docente

Presentamos un estudio exploratorio centrado en la reflexión de una maestra novel de matemáticas durante la etapa final de su formación inicial y su inmersión en la práctica. Analizamos el informe del Practicum y sus diarios de clases de acuerdo con la Grounded Theory. Nos fijamos en cómo es su reflexión en esos dos períodos, y la potencialidad de ésta para su desarrollo

Modelo de análisis de interacciones en un contexto colaborativo de desarrollo profesional

La participación de una maestra novel en un proyecto de investigación colaborativa se ha revelado decisiva para comprender su desarrollo profesional, respecto de la enseñanza de las matemáticas. El análisis de interacciones emerge como un elemento clave para comprender el qué y el cómo de ese desarrollo, porque a través de ellas la maestra construye su interpretación de las contribuciones de los demás, la cual modula el potencial formativo del contexto. Hemos desarrollado un instrumento de análisis de interacciones que pretende capturar tres rasgos dialógicos de cada contribución: la unidad de información, los copartícipes y los contextos que le dan sentido. Añadimos la columna de Contenido para registrar la aportación epistemológica de cada contribución al discurso

The impact of scale effects on the prevailing internet-based banking model in the US

Internet-based banks use a technology-intensive production process that may benefit from scale effects as they grow larger. This paper analyzes whether the predominant Internet-primary bank in the USA generates technology-based economies of scale. There is evidence of both favorable and adverse technology-based scale effects. As the leading Internet-primary bank gets larger, the financial performance gap with traditional banks shrinks while some of its critical competitive advantages wear down. The results suggest that unless the prevailing Internet-primary bank preserves the distinctive advantages of the Internet-based business model as it improves financial performance, it might end up converging with its branching competitors

Percepción social de acoso sexual en el trabajo

The sexual harassment in the work, is a social phenomenon that is going out to the light in the last years. The statistics inform about the shortage of denunciations that they take place in spite of being a phenomenon that every time becomes more visible in our company. The aim of the present study is to analyze the perception and information that exists related to the phenomenon of the sexual harassment as relevant variable for the accomplishment of programs of prevention both in professional futures and in the professionals who form a part of a job environment. One administered a questionnaire to a sample of 65 pupils / aces of the Qualifications of Psychology and 15 pupils / aces of the University of Huelva, and 44 persons who are immersed in the labour world. The results indicate lack of formation and information about the phenomenon of the sexual harassment as well as of awareness specially towards the victim.El acoso sexual en el trabajo, es un fenómeno social que está saliendo a la luz en los últimos años. Las estadísticas informan sobre la escasez de denuncias que se producen a pesar de ser un fenómeno que cada vez se hace más visible en nuestra sociedad. El objetivo del presente estudio es analizar la percepción e información que existe relacionado con el fenómeno del acoso sexual como variable relevante para la realización de programas de prevención tanto en futuros profesionales como en los profesionales que forman parte de un entorno laboral. Se administró un cuestionario a una muestra de 65 alumnos/as de la Titulación de Psicología y 15 alumnos/as de la Titulación de Ciencias del Trabajo de la Universidad de Huelva, y 44 personas que se encuentran inmersos en el mundo laboral. Los resultados indican falta de formación e información sobre el fenómeno del acoso sexual así como de sensibilización especialmente hacia la víctima

La escuela en Hunstanton: fachada reticulada vs fachada collage

After its sixty anniversary (and in spite of the fact that its architecture was left unprotected till the early 90s), the Secondary Modern School in Hunstanton by A+P Smithson remains as a perfect example of modernity in its own photogenic appearance. From the very moment it was built (1949-1953) till now, the dialectics formulated by its skin has been able to integrate into the landscape, as well as reconcile the functionality of their teaching program with it. The success of the language used in its different facades lies in the compositional rigor of mathematics taken to the extreme. The repetition as a projectual mechanism –both its constructive elements and the few necessary detail– makes this architecture an abstract entity, allowing dematerialize the perception of its large size. At the same time, each facade shares the ambiguity which is implied in combining simultaneously the visual permeability and the reflexes which are able to camouflage the interior. Variables as “velocity” and “approach” with which the covering is perceived –both from the inside and from the outside– make possible a game of gazes from this duality that resembles the facade elements as a “cinematographic frame”. Consequently, and placing this in the context of the inauguration of the building, Secondary Modern School in Hunstanton reminds the Free Cinema Movement.Tras su sexuaségimo aniversario –y a pesar de que su arquitectura quedó desprotegida hasta los primeros 90– la Secondary Modern School en Hunstanton, de A+P Smithson, sigue derrochando modernidad a través su fotogénica apariencia. Desde el momento en que fue construida (1949-1953) hasta hoy, la dialéctica formulada por su envolvente ha sido capaz de integrarla en el paisaje, así como de conciliar con el mismo la funcionalidad de su programa docente. El éxito del lenguaje empleado en sus distintas fachadas radica en el rigor de una matemática compositiva llevada al extremo. La repetición como mecanismo proyectual, tanto de sus elementos constructivos como de los contados detalles tipo, convierte su arquitectura en un ente abstracto, consiguiendo desmaterializar la percepción de su gran tamaño. Al mismo tiempo, cada fachada se hace partícipe de la ambigüedad que supone combinar simultáneamente la permeabilidad visual y los reflejos –capaces de camuflar su interior–. Las variables “velocidad” y “acercamiento”, con las que es percibida la envolvente tanto desde el interior como desde el exterior, hacen de esta dualidad un juego de miradas que asemeja los elementos de fachada a un “frame filmográfico” que, contextualizado en el momento en que fue inaugurada, recuerda al movimiento Free Cinema.

La fotografía de Nigel Henderson y la escuela en Hunstanton de A+P Smithson: una instantánea de la posguerra inglesa

Alison and Peter Smithson were great lovers of art and also were very interested in its evolution throughout history. After World War II, as certain functionalist reasonings from the architecture of the Modern Movement began to be questioned, from an artistic point of view the evolution of the dadaist material inside the surrealist movement started to be also questioned. In its multidisciplinary affiliation to the “Independent Group”, the Smithson met several artists who shared the same creative philosophy, among which was Nigel Henderson (1917-1985). Nigel Henderson can be considered a forgotten British pop culture pioneer whose work was focused on the photographic experimentation. When he moved to Bethnal Green (East London) he found a social reality more genuine and characteristic of postwar Britain and decided to turn it into his artistic theme. The two-dimensional imagery of Henderson is expanded by the Smithson’s three-dimensional space projected through its facade. The building skin has managed to continue exposing the school reality, so this establishes a new set of moving images. Each facade module is a sort of changing frame that converts the big surfaces in a video-sequence. Hunstanton School symbolises a real architectural event, a “snapshot” of its time, and reaffirms the importance the image as a document in the art world began to have. Despite the changes occurred in the building in order to adapt to the new programmatic requirements, flexibility of space and the “hologramic” capacity of its facade allow to develop a set of updated contents and images, perverting the definition of the initial temporality.Alison y Peter Smithson fueron unos grandes amantes del arte y, además, estaban muy interesados en la evolución del mismo a lo largo de la Historia. Tras la Segunda Guerra Mundial, al igual que se comenzaron a poner en duda determinados razonamientos funcionalistas característicos de la arquitectura del Movimiento Moderno, desde el punto de vista artístico se empezó a cuestionar el devenir dadaísta del material procedente del Movimiento Surrealista. En su filiación multidisciplinar al Independent Group, los Smithson conocieron a varios artistas que participaban de su misma filosofía creativa, entre los que destacaba Nigel Henderson (1917- 1985). Nigel Henderson puede considerarse un pionero olvidado de la cultura pop británica cuyo trabajo giraba en torno a la experimentación fotográfica. Cuando se mudó al barrio de Bethnal Green descubrió una realidad social que participaba de una cotidianeidad más genuina y característica de la Gran Bretaña de posguerra y decidió convertirla en material de estudio. El imaginario bidimensional de Henderson se extiende sobre el espacio tridimensional proyectado por los Smithson a través de su fachada. La piel del edificio ha conseguido seguir exponiendo la realidad docente constituyendo un nuevo conjunto de imágenes en movimiento. Cada módulo de cerramiento constituye una suerte de frame cambiante que convierte la fachada en video-secuencia. La escuela en Hunstanton simboliza un verdadero acontecimiento arquitectónico, una “instantánea” del momento en que fue engendrada y corrobora la importancia que comienza a tener la imagen como documento en el mundo del arte. A pesar de las modificaciones acaecidas en el edificio con el fin de adaptarse a los nuevos requerimientos programáticos, la flexibilidad del espacio y la capacidad “holográmica” de su envolvente permiten desenvolver un juego de actualización de contenidos e imágenes, pervirtiendo la definición de temporalidad inicial