1,363 research outputs found
A robust motion estimation and segmentation approach to represent moving images with layers
The paper provides a robust representation of moving images based on layers. To that goal, we have designed efficient motion estimation and segmentation techniques by affine model fitting suitable for the construction of layers. Layered representations, originally introduced by Wang and Adelson (see IEEE Transactions on Image Processing, vol.3, no.5, p.625-38, 1994) are important in several applications. In particular they are very appropriate for object tracking, object manipulation and content-based scalability which are among the main functionalities of the future MPEG-4 standard. In addition a variety of examples are provided that give a deep insight into the performance bounds of the representation of moving images using layers.Peer ReviewedPostprint (published version
Interpretive developments of the philosophy of education in the anglophone tradition: an attempt to systematise them
The introduction of the analytical method to the field of the philosophy of education led to a first golden age, which, as the method closed in on itself and isolated itself from educational reality, resulted in an epistemological and institutional crisis. In view of that crisis, the generations following that first period began a lively debate on how to move forward. This article, with the aim of considering the positions proposed, derives from this latter scenario. Its method is characterized by two basic elements. The first is a systematic review of all articles on philosophy of education by the main authors in the discipline. The second is a hermeneutic exercise that attempts to compose a unitary discourse combining the main sensitivities of all of them. This results in the identification of five notable groups that differ mainly in the relationship that philosophy of education must maintain with educational practice and, consequently, in how the philosopher’s exercise of education should be considered. This leads into a discussion about whether it is possible to consider all of these positions as integral parts of a whole that seeks to understand the phenomenon of education and improve it overall instead of regarding them as parts in themselves. If there is one reasonably clear conclusion, it is that it seems unlikely that a unifying perspective like the analytical one will reappear and that a dynamic of reciprocal dialogical relations is necessary as a new emerging paradigm.La introducción del método analítico en el ámbito de la filosofía de la educación dio lugar a una primera época dorada que, una vez el propio método se encerró en sí mismo y se aisló de la realidad educativa, originó una crisis epistemológica e institucional. Las generaciones posteriores a esa primera de Israel Scheffler y R. S. Peters, a la vista de esa crisis, comenzaron un amplio y rico debate sobre cómo conducirse en adelante. En ese último escenario nace este artículo, cuyo objetivo es realizar una aproximación a las principales posturas a la hora de comprender el área. El método que se ha seguido está caracterizado por dos notas esenciales. La primera, una revisión sistemática de todos los artículos sobre filosofía de la educación de los principales autores. La segunda, un ejercicio hermenéutico que intentará componer un discurso unitario con las principales sensibilidades de todos ellos. El resultado es la identificación de cinco grupos reseñables que difieren entre sí, principalmente, en la relación que ha de mantener la filosofía de la educación con la práctica educativa y, en consecuencia, cómo ha de pensarse el propio ejercicio del filósofo de la educación. Lo que da lugar a discusión sobre si no es posible pensar todas esas posturas, más que vistas en sí mismas parcialmente, como partes integrantes de un todo que busca comprender el fenómeno educativo y lo mejora globalmente. Pues, si hay una conclusión más o menos evidente, es que no parece que vaya a existir de nuevo una perspectiva unificadora como la analítica y que es necesario una dinámica de relaciones dialógicas recíprocas como nuevo paradigma emergente
Huelgas e intercambio político en España
A pesar de ser España uno de los países europeos con mayor actividad huelguística durante los últimos treinta años, la investigación empírica en este campo es inusualmente escasa y adolece de la falta de un análisis de largo recorrido. En este trabajo se aborda el estudio de la actividad huelguística en España durante las tres últimas décadas con el principal objetivo de desarrollar una explicación teóricamente fundada de su evolución y de sus principales mecanismos causales. Del análisis desarrollado se desprende que el acusado descenso de los niveles de conflictividad registrados durante los últimos quince años es atribuible al desplazamiento de la lucha por la distribución de la renta del mercado, donde la huelga es el principal mecanismo de presión, al ámbito político, donde las modalidades de actuación no se limitan a la huelg
La forma de las huelgas en España, 1905-2010
Conflict is a central element of industrial relations. Strikes are the most relevant aspect of the labor dispute and that the academic literature has given greater importance, both for its social significance –probably strikes have involved more workers than any other form of collective action during the twentieth century– as for its historical continuity, since the mid-nineteenth century strikes became the dominant form of social protest in industrial societies.This article examines strike activity in Spain during the twentieth century to explain its evolution. In contrast to other works that focus primarily on the intensity of strike activity, this research is focused on the shape of strikes, which allows observing the transformation suffered in its configuration. Therefore be seen as strikes have been modernized over the twentieth century. The results show that strikes in Spain have followed a logic of political action, and, therefore, not limited to the scope of the market.El conflicto es uno de los elementos centrales de las relaciones laborales. Las huelgas son el aspecto más destacado del conflicto de trabajo y al que la literatura académica ha concedido mayor trascendencia, tanto por su relevancia social —probablemente las huelgas han involucrado más trabajadores que cualquier otra forma de acción colectiva política o social durante el siglo XX— como por su continuidad histórica, ya que desde mediados del siglo XIX las huelgas se convirtieron en la forma dominante de protesta social en las sociedades industriales.En este artículo se analiza la actividad huelguística en España durante el siglo XX y se trata de dar una explicación teóricamente fundada a su evolución. A diferencia de otros trabajos que se centran principalmente en al intensidad de la actividad huelguística, en esta investigación se profundiza en la forma de las huelgas, lo que permite observar, más allá de los cambios en su intensidad, la transformación sufría en su configuración. Así, se muestra como las huelgas se han modernizado a lo largo del siglo XX. De los resultados obtenidos se desprende que las huelgas en España han seguido una lógica de acción política, y, por lo tanto, no limitada al ámbito del mercado
Evolutionary rule-based system for IPO underpricing prediction
Genetic And Evolutionary Computation Conference. Washington DC, USA, 25-29 June 2005Academic literature has documented for a long time the existence of important price gains in the first trading day of initial public offerings (IPOs).Most of the empirical analysis that has been carried out to date to explain underpricing through the offering structure is based on multiple linear regression. The alternative that we suggest is a rule-based system defined by a genetic algorithm using a Michigan approach. The system offers significant advantages in two areas, 1) a higher predictive performance, and 2) robustness to outlier patterns. The importance of the latter should be emphasized since the non-trivial task of selecting the patterns to be excluded from the training sample severely affects the results.We compare the predictions provided by the algorithm to those obtained from linear models frequently used in the IPO literature. The predictions are based on seven classic variables. The results suggest that there is a clear correlation between the selected variables and the initial return, therefore making possible to predict, to a certain extent, the closing price.This article has been financed by the Spanish founded research MCyT project TRACER, Ref: TIC2002-04498-C05-04M
The balance between cognitive and non-cognitive aspects of students’ well-being: a quantitative analysis
The objective of this work is to determine which students’ characteristics (of the 8th grade Spanish students) allow them finding a balance among different dimensions of well-being. Firstly, in order to measure the students’ well-being, we built four synthetic indexes related to anxiety, motivation, belonging to the educational centre and bullying. Then, different models are estimated using as explained variables those indexes and condition on students’ sociodemographic characteristics, use of ICTs, hours of study and a proxy for maturity. Based upon the estimated parameters a multiobjective problem is defined; the problem is solved with multiobjective programing using an achievement scalarazing function. The results allow to characterize the profile of those students who achieve an optimal balance among the different aspects of well-being evaluated, which may be used to design educational policies aimed at improving simultaneously cognitive and non-cognitive measures of students performance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Bitcoin: A long-run equilibrium with East Asian currencies
Treballs Finals del Màster de Ciències Actuarials i Financeres, Facultat d'Economia i Empresa, Universitat de Barcelona, Curs: 2019-2020, Tutor: Samer Ajour El ZeinThe purpose of the study will be focused on developing and demonstrating the existence of cointegration between the most important cryptocurrency in the world, BTC-Bitcoin, paired with three different local currencies from selected southeast Asian countries: China (BTC-CNY), South Korea (BTC-KRW) and Japan (BTC-JPY).
In order to achieve the proposed objective, it is extensively developed the entire process currently established by the most important econometric literature, from the analysis of stationarity of the series and the detection of unit roots to the validation of a VAR model to be contrasted with the Johansen test, its resultant cointegration equation (long-run model) and the dynamic adjustment for each of the target variables.
Finally, it has been proposed an ARDL bounds testing approach model to determine and contrast the results obtained with the Johansen test and ensure the existence of a real long-term relationship of the selected series, where the coefficients obtained that determine the link between integrated processes and steady state equilibrium (no growth steady state) using Johansen approach are: 0.0056 (lnBTCKRWt) and 0.0037 (lnBTCJPYt); and through the use of an ARDL bounds testing approach the following coefficients are obtained: 0.00556 (lnBTCKRWt) and 0.00426 (lnBTCJPYt
Teachers’ satisfaction as indicator of education system performance
We investigate the potential trade-off between some teacher characteristics, particularly teachers’ satisfaction, and different measures of pupils’ performance, in order to optimize the outputs of the Spanish education system. Our contribution to the existing literature is twofold: on the one hand, we provide estimates on the balance between teachers’ effectiveness and 4th grade students’ performance in Spain, by using recent survey data (TIMSS, 2011); on the other hand we implement a novel methodology which allows optimizing simultaneously a set of indicators on the outputs of the educational system. These analyses provide empirical evidence of the importance of investing in teacher satisfaction as a motivation mechanism for improving national educational achievement.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially supported by the Andalusian Regional Ministry of Innovation, Science and Enterprise (PAI group SEJ-532). We also acknowledge the research funding provided by Andalucía-Tech (Universidad de Malaga),the Research Plan of the University of Malaga (Capacity Building Programme I+D+i of Universities 2014-2015, FEDER Funds) and by the Ministry of Economy and Competitiveness of Spain (Research Project ECO2014-56397-P). Luis Alejandro Lopez-Agudo also acknowledges the research training provided by the “Programa de Doctorado en Economía y Empresa de la Universidad de Malaga”
A critical assessment of the goal replacement hypothesis for habitual behaviour
DL and SM was supported by grant PGC2018-094694-B-I00 (AEI / FEDER, UE) and grant 2017-T1/SOC-5147. (Comunidad de Madrid)
The Structure of Elongated Viral Capsids
AbstractThere are many viruses whose genetic material is protected by a closed elongated protein shell. Unlike spherical viruses, the structure and construction principles of these elongated capsids are not fully known. In this article, we have developed a general geometrical model to describe the structure of prolate or bacilliform capsids. We show that only a limited set of tubular architectures can be built closed by hemispherical icosahedral caps. In particular, the length and number of proteins adopt a very special set of discrete values dictated by the axial symmetry (fivefold, threefold, or twofold) and the triangulation number of the caps. The results are supported by experimental observations and simulations of simplified physical models. This work brings about a general classification of elongated viruses that will help to predict their structure, and to design viral cages with tailored geometrical properties for biomedical and nanotechnological applications
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