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

Ni filled flexible multi-walled carbon nanotube–polystyrene composite films as efficient microwave absorbers

In this letter, we report flexible, non corrosive, and light weight nickel nanoparticle@multi-walled carbon nanotube–polystyrene (Ni@MWCNT/PS) composite films as microwave absorbing material in the frequency range of S band (2-4 GHz). Dielectric permittivity and magnetic permeability of composites having 0.5 and 1.5 wt. % filler amount were measured using the cavity perturbation technique. Reflection loss maxima of 33 dB (at 2.7 GHz) and 24 dB (at 2.7 GHz) were achieved for 0.5 and 1.5 wt. % Ni@MWCNT/PS composite films of 6 and 4 mm thickness, respectively, suggesting that low concentrations of filler provide significant electromagnetic interference shielding

Flexible microwave absorbers based on barium hexaferrite, carbon black, and nitrile rubber for 2–12 GHz applications

Flexile single layer electromagnetic wave absorbers were designed by incorporating appropriate amounts of carbon black in a nitrile butadiene rubber matrix along with an optimized amount of magnetic counterpart, namely, barium hexaferrite for applications in S, C, and X-bands. Effective dielectric permittivity and magnetic permeability were measured using cavity perturbation method in the frequency range of 2–12 GHz. The microwave absorbing characteristics of the composites were studied in the S, C, and X-bands employing a model in which an electromagnetic wave is incident normally on a metal terminated single layer. Reflection loss exceeding 20 dB is obtained for all the samples in a wide frequency range of 2–12 GHz when an appropriate absorber thickness between 5 and 9mm is chosen. The impact of carbon black is clearly observed in the optimized composites on the mechanical strength, thickness, band width of absorption, dielectric properties,

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.

Butyl rubber- ceramic composites for flexible electronic applications

The first chapter of the thesis gives a general introduction about flexible electronics, dielectrics and composites. The recent developments in flexible electronics also discussed in this chapter. The preparation and characterization techniques used for the butyl rubber ceramic composites are given in chapter 2. The synthesis and characterization of butyl rubber filled with low permittivity ceramic composites are described in chapter 3. The chapter 4 deals with the synthesis and characterization of butyl rubber-high permittivity ceramic composites. The effect of high permittivity ceramic fillers such as TiO2, Sr2Ce2Ti5O15 and SrTiO3 on dielectric, thermal and mechanical properties was studied. The present investigation deals with synthesis, characterization and properties of butyl rubber composites with low, high and very high ceramic fillers and also the effect of particle size on dielectric, thermal and mechanical properties of selected composites.

A study on the performance of flexible pavements on mature soil subgrades

The country has witnessed tremendous increase in the vehicle population and increased axle loading pattern during the last decade, leaving its road network overstressed and leading to premature failure. The type of deterioration present in the pavement should be considered for determining whether it has a functional or structural deficiency, so that appropriate overlay type and design can be developed. Structural failure arises from the conditions that adversely affect the load carrying capability of the pavement structure. Inadequate thickness, cracking, distortion and disintegration cause structural deficiency. Functional deficiency arises when the pavement does not provide a smooth riding surface and comfort to the user. This can be due to poor surface friction and texture, hydro planning and splash from wheel path, rutting and excess surface distortion such as potholes, corrugation, faulting, blow up, settlement, heaves etc. Functional condition determines the level of service provided by the facility to its users at a particular time and also the Vehicle Operating Costs (VOC), thus influencing the national economy. Prediction of the pavement deterioration is helpful to assess the remaining effective service life (RSL) of the pavement structure on the basis of reduction in performance levels, and apply various alternative designs and rehabilitation strategies with a long range funding requirement for pavement preservation. In addition, they can predict the impact of treatment on the condition of the sections. The infrastructure prediction models can thus be classified into four groups, namely primary response models, structural performance models, functional performance models and damage models. The factors affecting the deterioration of the roads are very complex in nature and vary from place to place. Hence there is need to have a thorough study of the deterioration mechanism under varied climatic zones and soil conditions before arriving at a definite strategy of road improvement. Realizing the need for a detailed study involving all types of roads in the state with varying traffic and soil conditions, the present study has been attempted. This study attempts to identify the parameters that affect the performance of roads and to develop performance models suitable to Kerala conditions. A critical review of the various factors that contribute to the pavement performance has been presented based on the data collected from selected road stretches and also from five corporations of Kerala. These roads represent the urban conditions as well as National Highways, State Highways and Major District Roads in the sub urban and rural conditions. This research work is a pursuit towards a study of the road condition of Kerala with respect to varying soil, traffic and climatic conditions, periodic performance evaluation of selected roads of representative types and development of distress prediction models for roads of Kerala. In order to achieve this aim, the study is focused into 2 parts. The first part deals with the study of the pavement condition and subgrade soil properties of urban roads distributed in 5 Corporations of Kerala; namely Thiruvananthapuram, Kollam, Kochi, Thrissur and Kozhikode. From selected 44 roads, 68 homogeneous sections were studied. The data collected on the functional and structural condition of the surface include pavement distress in terms of cracks, potholes, rutting, raveling and pothole patching. The structural strength of the pavement was measured as rebound deflection using Benkelman Beam deflection studies. In order to collect the details of the pavement layers and find out the subgrade soil properties, trial pits were dug and the in-situ field density was found using the Sand Replacement Method. Laboratory investigations were carried out to find out the subgrade soil properties, soil classification, Atterberg limits, Optimum Moisture Content, Field Moisture Content and 4 days soaked CBR. The relative compaction in the field was also determined. The traffic details were also collected by conducting traffic volume count survey and axle load survey. From the data thus collected, the strength of the pavement was calculated which is a function of the layer coefficient and thickness and is represented as Structural Number (SN). This was further related to the CBR value of the soil and the Modified Structural Number (MSN) was found out. The condition of the pavement was represented in terms of the Pavement Condition Index (PCI) which is a function of the distress of the surface at the time of the investigation and calculated in the present study using deduct value method developed by U S Army Corps of Engineers. The influence of subgrade soil type and pavement condition on the relationship between MSN and rebound deflection was studied using appropriate plots for predominant types of soil and for classified value of Pavement Condition Index. The relationship will be helpful for practicing engineers to design the overlay thickness required for the pavement, without conducting the BBD test. Regression analysis using SPSS was done with various trials to find out the best fit relationship between the rebound deflection and CBR, and other soil properties for Gravel, Sand, Silt & Clay fractions. The second part of the study deals with periodic performance evaluation of selected road stretches representing National Highway (NH), State Highway (SH) and Major District Road (MDR), located in different geographical conditions and with varying traffic. 8 road sections divided into 15 homogeneous sections were selected for the study and 6 sets of continuous periodic data were collected. The periodic data collected include the functional and structural condition in terms of distress (pothole, pothole patch, cracks, rutting and raveling), skid resistance using a portable skid resistance pendulum, surface unevenness using Bump Integrator, texture depth using sand patch method and rebound deflection using Benkelman Beam. Baseline data of the study stretches were collected as one time data. Pavement history was obtained as secondary data. Pavement drainage characteristics were collected in terms of camber or cross slope using camber board (slope meter) for the carriage way and shoulders, availability of longitudinal side drain, presence of valley, terrain condition, soil moisture content, water table data, High Flood Level, rainfall data, land use and cross slope of the adjoining land. These data were used for finding out the drainage condition of the study stretches. Traffic studies were conducted, including classified volume count and axle load studies. From the field data thus collected, the progression of each parameter was plotted for all the study roads; and validated for their accuracy. Structural Number (SN) and Modified Structural Number (MSN) were calculated for the study stretches. Progression of the deflection, distress, unevenness, skid resistance and macro texture of the study roads were evaluated. Since the deterioration of the pavement is a complex phenomena contributed by all the above factors, pavement deterioration models were developed as non linear regression models, using SPSS with the periodic data collected for all the above road stretches. General models were developed for cracking progression, raveling progression, pothole progression and roughness progression using SPSS. A model for construction quality was also developed. Calibration of HDM–4 pavement deterioration models for local conditions was done using the data for Cracking, Raveling, Pothole and Roughness. Validation was done using the data collected in 2013. The application of HDM-4 to compare different maintenance and rehabilitation options were studied considering the deterioration parameters like cracking, pothole and raveling. The alternatives considered for analysis were base alternative with crack sealing and patching, overlay with 40 mm BC using ordinary bitumen, overlay with 40 mm BC using Natural Rubber Modified Bitumen and an overlay of Ultra Thin White Topping. Economic analysis of these options was done considering the Life Cycle Cost (LCC). The average speed that can be obtained by applying these options were also compared. The results were in favour of Ultra Thin White Topping over flexible pavements. Hence, Design Charts were also plotted for estimation of maximum wheel load stresses for different slab thickness under different soil conditions. The design charts showed the maximum stress for a particular slab thickness and different soil conditions incorporating different k values. These charts can be handy for a design engineer. Fuzzy rule based models developed for site specific conditions were compared with regression models developed using SPSS. The Riding Comfort Index (RCI) was calculated and correlated with unevenness to develop a relationship. Relationships were developed between Skid Number and Macro Texture of the pavement. The effort made through this research work will be helpful to highway engineers in understanding the behaviour of flexible pavements in Kerala conditions and for arriving at suitable maintenance and rehabilitation strategies. Key Words: Flexible Pavements – Performance Evaluation – Urban Roads – NH – SH and other roads – Performance Models – Deflection – Riding Comfort Index – Skid Resistance – Texture Depth – Unevenness – Ultra Thin White Topping

Berufsanforderungen und flexible Altersgrenze

In 1973 the government of the Federal Republic plans to introduce a flexible retirement age. According to this new law, old age pensions can be paid already to people who are 63 years of age instead of 65 as at present. The government thus hopes to do more justice to the difference in capacity for work of elderly insured people and to the lact that the decline of life of humans depends to a certain extent on the occupational requirements demanded of them. Based on social science and medical research results this essay shows that the flexible retirement age cannot master these problems. The essay mentions in particular general relationships between age and work as well as special relationships between practised work, illness, disability and age. The bibliography includes literature connected with other aspects of the flexible retirement age.

Managing Quality Properties of Web Service Compositions

Web services from different partners can be combined to applications that realize a more complex business goal. Such applications built as Web service compositions define how interactions between Web services take place in order to implement the business logic. Web service compositions not only have to provide the desired functionality but also have to comply with certain Quality of Service (QoS) levels. Maximizing the users' satisfaction, also reflected as Quality of Experience (QoE), is a primary goal to be achieved in a Service-Oriented Architecture (SOA). Unfortunately, in a dynamic environment like SOA unforeseen situations might appear like services not being available or not responding in the desired time frame. In such situations, appropriate actions need to be triggered in order to avoid the violation of QoS and QoE constraints. In this thesis, proper solutions are developed to manage Web services and Web service compositions with regard to QoS and QoE requirements. The Business Process Rules Language (BPRules) was developed to manage Web service compositions when undesired QoS or QoE values are detected. BPRules provides a rich set of management actions that may be triggered for controlling the service composition and for improving its quality behavior. Regarding the quality properties, BPRules allows to distinguish between the QoS values as they are promised by the service providers, QoE values that were assigned by end-users, the monitored QoS as measured by our BPR framework, and the predicted QoS and QoE values. BPRules facilitates the specification of certain user groups characterized by different context properties and allows triggering a personalized, context-aware service selection tailored for the specified user groups. In a service market where a multitude of services with the same functionality and different quality values are available, the right services need to be selected for realizing the service composition. We developed new and efficient heuristic algorithms that are applied to choose high quality services for the composition. BPRules offers the possibility to integrate multiple service selection algorithms. The selection algorithms are applicable also for non-linear objective functions and constraints. The BPR framework includes new approaches for context-aware service selection and quality property predictions. We consider the location information of users and services as context dimension for the prediction of response time and throughput. The BPR framework combines all new features and contributions to a comprehensive management solution. Furthermore, it facilitates flexible monitoring of QoS properties without having to modify the description of the service composition. We show how the different modules of the BPR framework work together in order to execute the management rules. We evaluate how our selection algorithms outperform a genetic algorithm from related research. The evaluation reveals how context data can be used for a personalized prediction of response time and throughput.

Competencias para una educación cosmopolita.

Monográfico con el título: 'Competencias Educativas'. Resumen basado en el de la publicación

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.

Design and Implementation of a Flexible Robot

This robot has low natural frequencies of vibration. Insights into the problems of designing joint and link flexibility are discussed. The robot has three flexible rotary actuators and two flexible, interchangeable links, and is controlled by three independent processors on a VMEbus. Results from experiments on the control of residual vibration for different types of robot motion are presented. Impulse prefiltering and slowly accelerating moves are compared and shown to be effective at reducing residual vibration.

Agrupamiento flexible de alumnos en la Educación Primaria : una respuesta a la diversidad.

Verificar la eficacia de una experiencia de innovación sobre agrupamiento flexible de alumnos en una estructura multinivel; focalizando el problema en la necesidad de responder a la diversidad existente en cada aula,diseñando, frente a la organización tradicional graduada, una nueva estructura organizativa que establece tres modalidades distintas de agrupamiento: multinivel propiamente dicho, para las Áreas de Lengua y Matemáticas; graduado para el resto de las áreas, y flexible según tareas; se contempla, así mismo una organización también flexible de profesores y una adaptación del curriculum escolar a dicha estructura.. Son objeto de investigación todos los alumnos de Primer Ciclo de Educación Primaria del CP de Las Vegas en Corvera de Asturias.. Tras la exposición del marco teórico sobre el que gira la experiencia de innovación (curriculum escolar y organización de la enseñanza) se hace una descripción del proceso de planificación y puesta en práctica de la nueva estructura organizativa y se analiza su incidencia sobre los alumnos implicados, en relación con su actitud ante la enseñanza y con su rendimiento académico.. Escalas, registros, entrevistas, diario de investigación, grabaciones de las clases, encuestas, cuestionarios, etc.. Análisis cualitativo de los registros observacionales, de los resultados de las entrevistas, del contenido del diario de investigación, de las producciones de los alumnos; porcentajes de rendimiento académico, de movilidad internivelar de los alumnos.. El análisis de los datos confirma los efectos positivos de la estructura multinivel sobre la actitud y rendimiento de los alumnos al permitir que cada uno, respetando sus condiciones de partida, progrese de acuerdo a su capacidad y a su ritmo de aprendizaje. El planteamiento cooperativo del trabajo docente permitió que los profesores mejorarán su práctica y dispusieran de un mayor control, sobre sus actividades, incrementando su desarrollo profesional.. La estructura multinivel constituye una buena alternativa al problema de atención a la diversidad al introducir elementos de mayor racionalidad y flexibilidad en el funcionamiento de los centros docentes. La rigidez de la estructura organizativa graduada y la enseñanza homogénea y uniforme que produce, apoyada básicamente en los libros de texto estandarizados, dificulta un tratamiento educativo más individualizado y la aplicación práctica de la teoría del progreso continuo..

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.