A Numerically efficient power optimization scheme for coded OFDM systems in achieving minimum frame error rate

Coded OFDM is a transmission technique that is used in many practical communication systems. In a coded OFDM system, source data are coded, interleaved and multiplexed for transmission over many frequency sub-channels. In a conventional coded OFDM system, the transmission power of each subcarrier is the same regardless of the channel condition. However, some subcarrier can suffer deep fading with multi-paths and the power allocated to the faded subcarrier is likely to be wasted. In this paper, we compute the FER and BER bounds of a coded OFDM system given as convex functions for a given channel coder, inter-leaver and channel response. The power optimization is shown to be a convex optimization problem that can be solved numerically with great efficiency. With the proposed power optimization scheme, near-optimum power allocation for a given coded OFDM system and channel response to minimize FER or BER under a constant transmission power constraint is obtained

Planar UWB Antenna with Modified Slotted Ground Plane

A compact coplanar waveguide-fed (CPW) monopole antenna for ultra-wideband wireless communication is presented. The proposed antenna comprises of a CPW-fed beveled rectangular patch with a modified slotted ground. The overall size of the antenna is 30 mm 27 mm 1.6 mm. The lower edge of the band is attained by properly decoupling the resonant frequencies due to the extended ground plane and the beveled rectangular patch of the antenna. The upper edge of the radiating band is enhanced by beveling the ground plane corners near the feed point. Experimental results show that the designed antenna operates in the 2.7–12 GHz band, for S11 10 dB with a gain of 2.7–5 dBi. Both the frequency domain and time domain characteristics of the antenna are investigated using antenna transfer function. It is observed that the antenna exhibits identical radiation patterns and reasonable transient characteristics over the entire operating band

Design Of Compact Microstrip Antennas Using A Modified Ground Plane

A method for simultaneously enhancing the bandwidth and reducing the size of microstrip antennas (MSAs) using a modified ground plane (GP) has been proposed with design formulas. A combshaped truncated GP is used for this purpose. This method provides an overall compactness up to 85% for proximity-coupled MSAs in the frequency range of 900 MHz–5.5 GHz with an improvement inbandwidth up to seven times when compared with the conventional ones

Isp Knowledge Portal : A Resource Discovery Tool In Optics

The need to structure knowledge is as important now as it ever has been. This paper has tried to study the ISP knowledge portal to explore how knowledge on various resources and topics in photonics and related areas are organized in the knowledge portal of International School of Photonics, CUSAT. The study revealed that ISP knowledge portal is one of the best portals in the filed. It provides a model for building an effective knowledge portal in other fields

Single Frame Image Super Resolution Using Learned Directionlets

In this paper, a new directionally adaptive, learning based, single image super resolution method using multiple direction wavelet transform, called Directionlets is presented. This method uses directionlets to effectively capture directional features and to extract edge information along different directions of a set of available high resolution images .This information is used as the training set for super resolving a low resolution input image and the Directionlet coefficients at finer scales of its high-resolution image are learned locally from this training set and the inverse Directionlet transform recovers the super-resolved high resolution image. The simulation results showed that the proposed approach outperforms standard interpolation techniques like Cubic spline interpolation as well as standard Wavelet-based learning, both visually and in terms of the mean squared error (mse) values. This method gives good result with aliased images also.

Effect of Concentration of DYE on the Storage Life of Plane Wave Gratings on Photopolymer Film

Holographic grating with good storage life in poly(vinyl alcohol) based photopolymer film, prepared by gravity settling method, with reduced concentration of the dye was found to give good diffraction efficiency without crosslinking. The material was found to show good diffraction efficiency and sensitivity (75% diffraction efficiency at exposure energy of 80 mJ/cm2). The shelf life of the photopolymer solution could be improved by storage at a temperature 4 C in refrigerator

Generic Finite Element Model for Mechanically Consistent Scaling of Composite Beam-to-column Joint with Welded Connection

To study the behaviour of beam-to-column composite connection more sophisticated finite element models is required, since component model has some severe limitations. In this research a generic finite element model for composite beam-to-column joint with welded connections is developed using current state of the art local modelling. Applying mechanically consistent scaling method, it can provide the constitutive relationship for a plane rectangular macro element with beam-type boundaries. Then, this defined macro element, which preserves local behaviour and allows for the transfer of five independent states between local and global models, can be implemented in high-accuracy frame analysis with the possibility of limit state checks. In order that macro element for scaling method can be used in practical manner, a generic geometry program as a new idea proposed in this study is also developed for this finite element model. With generic programming a set of global geometric variables can be input to generate a specific instance of the connection without much effort. The proposed finite element model generated by this generic programming is validated against testing results from University of Kaiserslautern. Finally, two illustrative examples for applying this macro element approach are presented. In the first example how to obtain the constitutive relationships of macro element is demonstrated. With certain assumptions for typical composite frame the constitutive relationships can be represented by bilinear laws for the macro bending and shear states that are then coupled by a two-dimensional surface law with yield and failure surfaces. In second example a scaling concept that combines sophisticated local models with a frame analysis using a macro element approach is presented as a practical application of this numerical model.

First-principles electronic theory of non-collinear magnetic order in transition-metal nanowires

The structural, electronic and magnetic properties of one-dimensional 3d transition-metal (TM) monoatomic chains having linear, zigzag and ladder geometries are investigated in the frame-work of first-principles density-functional theory. The stability of long-range magnetic order along the nanowires is determined by computing the corresponding frozen-magnon dispersion relations as a function of the 'spin-wave' vector q. First, we show that the ground-state magnetic orders of V, Mn and Fe linear chains at the equilibrium interatomic distances are non-collinear (NC) spin-density waves (SDWs) with characteristic equilibrium wave vectors q that depend on the composition and interatomic distance. The electronic and magnetic properties of these novel spin-spiral structures are discussed from a local perspective by analyzing the spin-polarized electronic densities of states, the local magnetic moments and the spin-density distributions for representative values q. Second, we investigate the stability of NC spin arrangements in Fe zigzag chains and ladders. We find that the non-collinear SDWs are remarkably stable in the biatomic chains (square ladder), whereas ferromagnetic order (q =0) dominates in zigzag chains (triangular ladders). The different magnetic structures are interpreted in terms of the corresponding effective exchange interactions J(ij) between the local magnetic moments μ(i) and μ(j) at atoms i and j. The effective couplings are derived by fitting a classical Heisenberg model to the ab initio magnon dispersion relations. In addition they are analyzed in the framework of general magnetic phase diagrams having arbitrary first, second, and third nearest-neighbor (NN) interactions J(ij). The effect of external electric fields (EFs) on the stability of NC magnetic order has been quantified for representative monoatomic free-standing and deposited chains. We find that an external EF, which is applied perpendicular to the chains, favors non-collinear order in V chains, whereas it stabilizes the ferromagnetic (FM) order in Fe chains. Moreover, our calculations reveal a change in the magnetic order of V chains deposited on the Cu(110) surface in the presence of external EFs. In this case the NC spiral order, which was unstable in the absence of EF, becomes the most favorable one when perpendicular fields of the order of 0.1 V/Å are applied. As a final application of the theory we study the magnetic interactions within monoatomic TM chains deposited on graphene sheets. One observes that even weak chain substrate hybridizations can modify the magnetic order. Mn and Fe chains show incommensurable NC spin configurations. Remarkably, V chains show a transition from a spiral magnetic order in the freestanding geometry to FM order when they are deposited on a graphene sheet. Some TM-terminated zigzag graphene-nanoribbons, for example V and Fe terminated nanoribbons, also show NC spin configurations. Finally, the magnetic anisotropy energies (MAEs) of TM chains on graphene are investigated. It is shown that Co and Fe chains exhibit significant MAEs and orbital magnetic moments with in-plane easy magnetization axis. The remarkable changes in the magnetic properties of chains on graphene are correlated to charge transfers from the TMs to NN carbon atoms. Goals and limitations of this study and the resulting perspectives of future investigations are discussed.

Creamos nuestro portal educativo : iespabloolavide.org.

Se presenta memoria final de proyecto educativo que muestra el desarrollo de un campus virtual, que permita equilibrar las carencias TICs del centro y su entorno social, en especial en el alumnado con una situación socioeconómica baja, ya que las conexiones serían wireless, evitando el coste de mantenimiento de conexiones ADSL a la mayoría del alumnado, fomentaría el empleo de las TICs por parte del profesorado y de toda la comunidad educativa. Se realiza en el IES Pablo de Olavide en La Carolina, Jaén. Los objetivos son: disponer de un dominio en internet; disponer de un servidor para soporte de dicho dominio; gestión de nuestro propio correo electrónico; disponer de un espacio web propio para publicar información por parte de profesores, departamentos, alumnos y padres; acceso a internet en todo el centro mediante cable y conexiones wireless; familiarizarse con el uso de software libre por parte de nuestra comunidad educativa; difundir entre la comunidad educativa un sistema de comunicación respetuoso con el medio ambiente, permitiendo un ahorro tanto de papel como en el trasporte de documentos convencional; creación de una página web con contenidos exclusivamente relacionados con el ámbito económico-empresarial; fomentar en el alumnado el conocimiento y el uso de las nuevas tecnologías de la información y de la comunicación; dotar al profesorado de un nuevo instrumento ameno y didáctico con el que desarrollar el proceso de enseñanza-aprendizaje; proporcionar al alumnado conocimientos de índole informático que les puedan resultar útiles en su futuro académico y profesional; aprovechar la inversión que ha realizado la Junta de Andalucía en el centro en lo referente a la dotación de material informático. El proceso consta de varias fases: contratación del dominio y aumento a 2 mbits del acceso a internet; cableado de la biblioteca y departamentos; actualización hardware del servidor; alta en el servidor a todo el profesorado; formación del profesorado en el uso del portal; alojamiento en el portal de un espacio para cada departamento, profesor, grupo y asociación de padres; compromiso de los departamentos a publicar materiales didácticos; actualización del software libre del servidor; configuración de servicios, publicación de una revista digital; rodaje del portal con al menos un grupo por etapa.

Uso de Internet y portal enlaces en las Escuelas Básicas de la Comuna de Valparaíso.

Conocer la realidad en torno al uso de Internet y el uso que hacen los docentes del Portal Enlaces del Ministerio de Educación chileno considerando los factores esenciales para la utilización de futuras estrategias, técnicas o materiales que puedan desarrollarse para aprovechar educativamente los potenciales de las páginas web. 25 establecimientos que imparten Educación Básica para niños en la Comuna de Valparaíso (Chile). Para la recogida de información se opta por la utilización de una encuesta estructurada que se aplico a los profesores de los centros participantes en el estudio. a) Un gran porcentaje de los profesores encuestados se ha conectado en alguna ocasión a Internet, poseen correo electrónico, obtienen recursos para su labor educativa a través de la red y visitan periódicamente sitios de Internet; b) Un porcentaje menor del profesorado admite haber participado en un chat o en una videoconferencia y señalan conocer cuales son los servicios que pueden obtener de Internet; c) Menos de la mitad de los profesores conocen los objetivos del Portal Enlaces; d) Solo un doce por ciento visita periódicamente este portal; e) Más del setenta por ciento del profesorado nunca ha participado en el foro de Enlaces y un veintiuno por ciento declara haberlo hecho en una ocasión. a) Existe un buen grado de conocimientos y manejo de Internet por parte de los profesores; b) La gran mayoría de ellos no lo han logrado a través del Portal Enlaces; c) La experiencia acumulada respecto al tema de Internet, por parte de los docentes, no es necesariamente fruto del uso de Internet con fines educativos; d) El portal Enlaces está lejos de ser un sitio que cumpla con los objetivos de unir a los estudiantes y profesores del país y de ser un lugar usado normalmente por los docentes para obtener materiales, ideas, etc.

Portal web per la localitzacó de restaurants

Desenvolupament,anàlisi, disseny i implementació d’un portal web, tipus cercador, per la recerca i localització d’establiments tipus restaurant, bars, bufets, etc,. Per altra banda es pretén oferir un sistema de gestió d’informació on les empreses del sector gastronòmic puguin mostrar la seva informació i la seva oferta

Portal de convivencia en Arag??n

P??gina web relacionada con la materia de convivencia. Se ofrece una plataforma para la divulgaci??n de los valores universales de la cultura de paz y a dar a conocer el importante trabajo que, en el ??mbito de la convivencia, desarrollan los centros docentes de Arag??n. Sirve como lugar de encuentro de la comunidad educativa, adem??s de posibilitar el intercambio de experiencias, el env??o de preguntas y sugerencias, la consulta de documentaci??n oficial, art??culos de prensa, herramientas de trabajo, novedades, enlaces de inter??s, etc..

Orientación : portal de educación orientativa de Aragón.

Página web del programa de orientación educativa, que incide especialmente en los alumnos para el conocimiento y valoración de sus propias aptitudes e intereses, en el desarrollo personal y de aprendizaje, y para que sea capaz de elegir y prepararse para la vida profesional. Su objetivo es servir de plataforma para la divulgación de experiencias e intercambio de materiales y recursos. Se publica información relacionada con la legislación vigente, actividades de formación, programas que se hayan llevado a cabo, bibliografía y enlaces de interés.

A escena : portal de teatro.

Página web del proyecto 'Teatro en la web'. Su objetivo es servir de plataforma para la divulgación de actividades de dramatización y teatro como parte de la educación básica. Sirve como lugar de encuentro de la comunidad educativa, además de posibilitar el intercambio de experiencias, el envío de preguntas y sugerencias, la consulta de actividades, talleres, enlaces, noticias e información.

Portal aragonés de meterología escolar.

Portal de meteorología que pretende poner al alcance una herramienta sencilla, intuitiva y versátil que permita hacer un seguimiento continuado, cómodo y completo de los datos que se obtienen para el estudio de la climatología. Las propuestas son adaptables a cada curso o centro y cada uno puede disponer de acceso autentificado al portal para que los alumnos introduzcan los datos que vayan tomando y los guarden para su consulta, análisis y comparación con otras localidades o comarcas.