4,829 research outputs found
The number of maximal torsion cosets in subvarieties of tori
We present sharp bounds on the number of maximal torsion cosets in a
subvariety of the complex algebraic torus . Our
first main result gives a bound in terms of the degree of the defining
polynomials. A second result gives a bound in terms of the toric degree of the
subvariety.
As a consequence, we prove the conjectures of Ruppert and of Aliev and Smyth
on the number of isolated torsion points of a hypersurface. These conjectures
bound this number in terms of the multidegree and the volume of the Newton
polytope of a polynomial defining the hypersurface, respectively.Comment: 21 page
On isogenies of Prym varieties
We prove an extension of the Babbage-Enriques-Petri theorem for
semi-canonical curves. We apply this to show that the Prym variety of a generic
element of a codimension subvariety of is not isogenous
to another distinct Prym variety, under some mild assumption on .Comment: 8 page
External heating of a flat plate in a convective flow
The steady-state and Ãransient processes of the exteinal heating of a flat pÃate under a convective flow is studied in thÃs paper, with inclusión of the axial heat conduction tÃirough the pÃate. The balance equations reduce to a single integro-differential equation with only one parameter, a, denoting the ratio of the ability of the pÃate tocarry heat inthestreamwisedirectionto the abilityof the gas tocarry heat outof the pÃate. The two IÃmits of a good conducting plate ([alpha]-»[infinite]) and a bad conducting plate ([alpha]-»[infinite]) are analised through the application of a regular perturbation procedure for the first case and a singular perturbation technique for the latter. The existence of two boundary layers at both edges of the pÃate is shown and their structure are analysed. The evolution of the temperature of the pÃate is then obtained for a constant external energy flux input
The effects of displacement induced by thermal perturbations on the structure and stability of boundary-layer flows
The free-interaction influence of a thermal expansión process in boundary-layer gas flow is analyzed using the formalism of triple-deck theory. The physical model considered is the forced convection of a gas flowing over a flat plate subject to a heated slab. Both linearized and full nonlinear solutions are obtained using Fourier transform methods and spectral numericaà techniques. The influence of monochromatic thermal perturbation on boundary-layer stability (lower branch) is studied and first-ordcr correction of the lower branch neutral stability curve for the boundary-layer flow has been obtained. The shift of neutral stability is then computed for different values of the therma! perturbation wave number, making unstable some otherwise stable modes
Mixing layer ignition of hydrogen
A theoretical analysis is given for the high-temperature ignition in a laminar mixing layer between hydrogen and air at the high temperatures characteristic of supersonic combustión. We analyze the most important practical case where the temperature of the air stream is higher than that of the hydrogen stream. In this case, the chemical reactions responsible for ignition occur in the air side of the mixing layer, where the mixture is lean. A simplified reduced mechanism is found to describe the ignition process. The radicáis OH and H follow the steady-state approximation while the radical O is the chain branching species following an autocatalytic reaction with moderately large activation energy. Numerical results of the governing equations for large valúes of the activation energy are presented and from a symplified analysis, we obtain a closed form solution of the ignition distance as a function of the physicochemical parameters
Una aproximación crÃtica a las tasas judiciales desde el derecho financiero y tributario
El presente trabajo examina la implantación de las nuevas tasas judiciales tras la aprobación de la Ley 10/2012 (y su posterior reforma). El autor realiza un análisis crÃtico desde el ámbito del derecho financiero y tributario. En particular, se centra en la finalidad declarada de la medida adoptada, asà como en los lesivos efectos que puede tener sobre los usuarios del sistema judicialThis work examines the implementation of the new court fees, as a result of the Act
10/2012 (and its recent amendment). The author undertakes a critical analysis from the perspective
of tax and budgetary law. In particular, he focuses on the alleged purpose of this measure, as
well as the potential harmful effects on users of the justice syste
Competencias en el dÃa a dÃa de una ETT
Treball Final de Mà ster Universitari en Psicologia del Treball, de les Organitzacions i en Recursos Humans. Codi: SAK034. Curs: 2014/2015El siguiente trabajo de fin de máster (TFM) corresponde al Máster en psicologÃa del trabajo, de
las organizaciones y de los recursos humanos que se imparte en la Universitat Jaume I de
Castellón de la plana. El TFM incluye, en primer lugar, un breve resumen de aquellos aspectos
que el estudiante responsable ha considerado más importantes de cada asignatura del máster.
Posteriormente, se analizan y desarrollan las diferentes competencias, divididas en tres bloques
(básicas, profesionales del rol profesional y facilitadoras) que el estudiante ha podido aplicar en
sus prácticas externas, y valorando el nivel de las competencias antes y después del máster. A
continuación, se realiza una valoración personal, en la que el estudiante hablará de los aspectos
tanto positivos como negativos que se pueden mejorar respecto a las competencias. Por último,
tendrá lugar una breve reflexión personal acerca de su futuro profesional, hablando de donde se
ve y donde le gustarÃa trabajar de aquà a unos años, y sobre la posibilidad de utilizar los
conocimientos aprendidos en el desarrollo de su carrera profesional.The next TFM belongs to the work, organisations and human resources psycology master of the
University Jaume I in Castellon de la plana. The TFM includes, first of all, a short resume
about those aspects that the student has been considered especially important in each subject of
the master.The next step it´s and analysis of the diferent competences that the student has been
applied during the practicum and a assesment of the competences before and after the master.A
personal assesment about the positive an negative aspect of the development of the competences
is the third point, and a personal assesment about the possible profesional future and
development concludes the TFM
MetodologÃa para maximizar la rentabilidad de una terminal marÃtima de contenedores a través de la optimización de su grado de automatización
Son generalmente aceptadas las tendencias actuales de maximización de la automatización
para la adaptación de las terminales marÃtimas de contenedores a las cada vez mayores
exigencias competitivas del negocio de transporte de contenedores. En esta investigación, se
somete a consideración dichas tendencias a través de un análisis que tenga en cuenta la
realidad global de la terminal pero también su propia realidad local que le permita aprovechar
sus fortalezas y minimizar sus debilidades en un mercado continuamente en crecimiento y
cambio.
Para lo cual se ha desarrollado un modelo de análisis en el que se tengan en cuenta los
parámetros técnicos, operativos, económicos y financieros que influyen en el diseño de una
terminal marÃtima de contenedores, desde su concepción como ente dependiente para generar
negocio, todos ellos dentro de un perÃmetro definido por el mercado del tráfico de contenedores
asà como las limitaciones fÃsicas introducidas por la propia terminal.
Para la obtención de dicho modelo ha sido necesario llevar a cabo un proceso de estudio del
contexto actual del tráfico de contenedores y su relación con el diseño de las terminales
marÃtimas, asà como de las metodologÃas propuestas hasta ahora por los diferentes autores
para abordar el proceso de dimensionamiento y diseño de la terminal.
Una vez definido el modelo que ha de servir de base para el diseño de una terminal marÃtima
de contenedores desde un planteamiento multicriterio, se analiza la influencia de las diversas
variables explicativas de dicho modelo y se cuantifica su impacto en los resultados
económicos, financieros y operativos de la terminal.
Un paso siguiente consiste en definir un modelo simplificado que vincule la rentabilidad de una
concesión de terminal con el tráfico esperado en función del grado de automatización y del tipo
de terminal.
Esta investigación es el fruto del objetivo ambicioso de aportar una metodologÃa que defina la
opción óptima de diseño de una terminal marÃtima de contenedores apoyada en los pilares de
la optimización del grado de automatización y de la maximización de la rentabilidad del negocio
que en ella se desarrolla. It is generally accepted current trends in automation to maximize the adaptation of maritime
container terminals to the growing competitive demands of the business of container shipping.
In this research, is submitted to these trends through an analysis taking into account the global
reality of the terminal but also their own local reality it could exploit its strengths and minimize
their weaknesses in a market continuously growing and changing.
For which we have developed a model analysis that takes into account the technical,
operational, financial and economic influence in the design of a container shipping terminal,
from its conception as being dependent to generate business, all within a perimeter defined by
the market of container traffic and the physical constraints introduced by the terminal.
To obtain this model has been necessary to conduct a study process in the current context of
container traffic and its relation to the design of marine terminals, as well as the methodologies
proposed so far by different authors to address the process sizing and design of the terminal.
Having defined the model that will serve as the basis for the design for a container shipping
terminal from a multi-criteria approach, we analyze the influence of various explanatory
variables of the model and quantify their impact on economic performance, financial and
operational of the terminal.
A next step is to define a simplified model that links the profitability of a terminal concession with
traffic expected on the basis of the degree of automation and the kind of terminal.
This research is the result of the ambitious target of providing a methodology to define the
optimal choice of designing a container shipping terminal on the pillars of automation optimizing
and maximizing the profitability of the business that it develops
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