Caracterización de usuario y tráfico en la evolución de la banda ancha en España

El mundo de las telecomunicaciones evoluciona a gran velocidad, acorde con las necesidades de los usuarios. El crecimiento del número de servicios a través de las conexiones que actualmente utilizamos para conectarnos a Internet (Ej. IPTV) con elevados requerimientos de ancho de banda, que junto a los servicios de nuevo nacimiento (ej. OTT), contribuyen tanto al aumento de la necesidad de mayores velocidades de conexión de los usuarios como a la implantación de nuevos modelos de calidad de servicio. Las redes de datos de banda ancha (fija y móvil) actuales deben, por lo tanto, experimentar una profunda transformación para conseguir solventar de una forma eficiente los problemas y las necesidades de tráfico, pudiendo así absorber el progresivo incremento del ancho de banda, dejando las puertas abiertas a futuras mejoras. Y para ello las operadoras se nutrirán con la valiosa información de tráfico y usuario que les lleven a tomar las mejores decisiones de cara a que las transformaciones llevadas a cabo cubran exactamente lo que el usuario demanda de la forma más eficiente posible. Con estas premisas, surgieron las ideas que se plasmaron como objetivos del PFC : La idea de narrar el despliegue de la banda ancha en España desde sus orígenes hasta la actualidad, enfocando su crecimiento desde un punto de vista sociotecnológico. Dando continuidad al punto anterior, se persiguió la idea de conocer las herramientas sociales y tecnológicas a raíz de las cuales se pueda realizar una previsión del tráfico en las redes de las operadoras en un futuro cercano. La pretensión de mostrar las características de los usuarios de banda ancha y del tráfico de datos que generan, que son de carácter crítico para las operadoras en la elaboración de forma adecuada de la planificación de sus redes. La intención de revelar los procedimientos de las operadoras para que, una vez conocidas las características de sus usuarios, se puedan cumplir los requisitos demandados por los mismos: QoS y los indicadores clave de rendimiento (KPIs) Por otro lado, el nivel de detalle dado pretende adecuarse a un público que no tenga profundos conocimientos sobre la materia, y salvo partes bastante concretas, se puede catalogar este trabajo como de abierto al público en general. ABSTRACT. The world of telecommunications is evolving at high speed, according to the needs of users. The growing of services number through the connections that currently have been used to connect to the Internet (eg IPTV ) with high bandwidth requirements, which together with the new birth services (eg OTT ) contribute both to increased the need for higher connection speeds users and the implementation of new models of service quality. Data networks broadband (fixed and mobile ) today must , therefore, undergo a deep transformation to achieve an efficient solving problems and traffic needs, thus being able to absorb the gradual increase of bandwidth, leaving the door open to future improvements. And for that the operators will be nurtured with valuable information and user traffic that lead them to make better decisions in the face of the transformations carried out exactly meet the user demand for the most efficient possible way. With these assumptions, the ideas that emerged were expressed as PFC objectives : The idea of narrating the broadband deployment in Spain from its origins to the present, focusing its growth from a socio-technological approach. Continuing the previous point, it pursued the idea of knowing the social tools and technology as a result of which it can perform a traffic forecast operators networks in the near future. The attempt to show the characteristics of broadband users and data traffic they generate, which are mission critical for operators in developing adequately planning their networks. The intention to disclose procedures for operators, once known the characteristics of their users, it can meet the requirements demanded by them: QoS and key performance indicators (KPI). On the other hand, the level of detail given suit seeks an audience that does not have deep knowledge on the subject, unless quite specific parts, this work can be classified as open to the general public.

SolarPaces 2013: Innovations on direct steam generation in linear fresnel collectors

Direct Steam Generation (DSG) in Linear Fresnel (LF) solar collectors is being consolidated as a feasible technology for Concentrating Solar Power (CSP) plants. The competitiveness of this technology relies on the following main features: water as heat transfer fluid (HTF) in Solar Field (SF), obtaining high superheated steam temperatures and pressures at turbine inlet (500ºC and 90 bar), no heat tracing required to avoid HTF freezing, no HTF degradation, no environmental impacts, any heat exchanger between SF and Balance Of Plant (BOP), and low cost installation and maintenance. Regarding to LF solar collectors, were recently developed as an alternative to Parabolic Trough Collector (PTC) technology. The main advantages of LF are: the reduced collector manufacturing cost and maintenance, linear mirrors shapes versus parabolic mirror, fixed receiver pipes (no ball joints reducing leaking for high pressures), lower susceptibility to wind damages, and light supporting structures allowing reduced driving devices. Companies as Novatec, Areva, Solar Euromed, etc., are investing in LF DSG technology and constructing different pilot plants to demonstrate the benefits and feasibility of this solution for defined locations and conditions (Puerto Errado 1 and 2 in Murcia Spain, Lidellin Newcastle Australia, Kogran Creek in South West Queensland Australia, Kimberlina in Bakersfield California USA, Llo Solar in Pyrénées France,Dhursar in India,etc). There are several critical decisions that must be taken in order to obtain a compromise and optimization between plant performance, cost, and durability. Some of these decisions go through the SF design: proper thermodynamic operational parameters, receiver material selection for high pressures, phase separators and recirculation pumps number and location, pipes distribution to reduce the amount of tubes (reducing possible leaks points and transient time, etc.), etc. Attending to these aspects, the correct design parameters selection and its correct assessment are the main target for designing DSG LF power plants. For this purpose in the recent few years some commercial software tools were developed to simulatesolar thermal power plants, the most focused on LF DSG design are Thermoflex and System Advisor Model (SAM). Once the simulation tool is selected,it is made the study of the proposed SFconfiguration that constitutes the main innovation of this work, and also a comparison with one of the most typical state-of-the-art configuration. The transient analysis must be simulated with high detail level, mainly in the BOP during start up, shut down, stand by, and partial loads are crucial, to obtain the annual plant performance. An innovative SF configurationwas proposed and analyzed to improve plant performance. Finally it was demonstrated thermal inertia and BOP regulation mode are critical points in low sun irradiation day plant behavior, impacting in annual performance depending on power plant location.

Correction of the Colour Variations under Uncontrolled Lighting Conditions

Esta tesis trata sobre métodos de corrección que compensan la variación de las condiciones de iluminación en aplicaciones de imagen y video a color. Estas variaciones hacen que a menudo fallen aquellos algoritmos de visión artificial que utilizan características de color para describir los objetos. Se formulan tres preguntas de investigación que definen el marco de trabajo de esta tesis. La primera cuestión aborda las similitudes que se dan entre las imágenes de superficies adyacentes en relación a su comportamiento fotométrico. En base al análisis del modelo de formación de imágenes en situaciones dinámicas, esta tesis propone un modelo capaz de predecir las variaciones de color de la región de una determinada imagen a partir de las variaciones de las regiones colindantes. Dicho modelo se denomina Quotient Relational Model of Regions. Este modelo es válido cuando: las fuentes de luz iluminan todas las superficies incluídas en él; estas superficies están próximas entre sí y tienen orientaciones similares; y cuando son en su mayoría lambertianas. Bajo ciertas circunstancias, la respuesta fotométrica de una región se puede relacionar con el resto mediante una combinación lineal. No se ha podido encontrar en la literatura científica ningún trabajo previo que proponga este tipo de modelo relacional. La segunda cuestión va un paso más allá y se pregunta si estas similitudes se pueden utilizar para corregir variaciones fotométricas desconocidas en una región también desconocida, a partir de regiones conocidas adyacentes. Para ello, se propone un método llamado Linear Correction Mapping capaz de dar una respuesta afirmativa a esta cuestión bajo las circunstancias caracterizadas previamente. Para calcular los parámetros del modelo se requiere una etapa de entrenamiento previo. El método, que inicialmente funciona para una sola cámara, se amplía para funcionar en arquitecturas con varias cámaras sin solape entre sus campos visuales. Para ello, tan solo se necesitan varias muestras de imágenes del mismo objeto capturadas por todas las cámaras. Además, este método tiene en cuenta tanto las variaciones de iluminación, como los cambios en los parámetros de exposición de las cámaras. Todos los métodos de corrección de imagen fallan cuando la imagen del objeto que tiene que ser corregido está sobreexpuesta o cuando su relación señal a ruido es muy baja. Así, la tercera cuestión se refiere a si se puede establecer un proceso de control de la adquisición que permita obtener una exposición óptima cuando las condiciones de iluminación no están controladas. De este modo, se propone un método denominado Camera Exposure Control capaz de mantener una exposición adecuada siempre y cuando las variaciones de iluminación puedan recogerse dentro del margen dinámico de la cámara. Los métodos propuestos se evaluaron individualmente. La metodología llevada a cabo en los experimentos consistió en, primero, seleccionar algunos escenarios que cubrieran situaciones representativas donde los métodos fueran válidos teóricamente. El Linear Correction Mapping fue validado en tres aplicaciones de re-identificación de objetos (vehículos, caras y personas) que utilizaban como caracterísiticas la distribución de color de éstos. Por otra parte, el Camera Exposure Control se probó en un parking al aire libre. Además de esto, se definieron varios indicadores que permitieron comparar objetivamente los resultados de los métodos propuestos con otros métodos relevantes de corrección y auto exposición referidos en el estado del arte. Los resultados de la evaluación demostraron que los métodos propuestos mejoran los métodos comparados en la mayoría de las situaciones. Basándose en los resultados obtenidos, se puede decir que las respuestas a las preguntas de investigación planteadas son afirmativas, aunque en circunstancias limitadas. Esto quiere decir que, las hipótesis planteadas respecto a la predicción, la corrección basada en ésta y la auto exposición, son factibles en aquellas situaciones identificadas a lo largo de la tesis pero que, sin embargo, no se puede garantizar que se cumplan de manera general. Por otra parte, se señalan como trabajo de investigación futuro algunas cuestiones nuevas y retos científicos que aparecen a partir del trabajo presentado en esta tesis. ABSTRACT This thesis discusses the correction methods used to compensate the variation of lighting conditions in colour image and video applications. These variations are such that Computer Vision algorithms that use colour features to describe objects mostly fail. Three research questions are formulated that define the framework of the thesis. The first question addresses the similarities of the photometric behaviour between images of dissimilar adjacent surfaces. Based on the analysis of the image formation model in dynamic situations, this thesis proposes a model that predicts the colour variations of the region of an image from the variations of the surrounded regions. This proposed model is called the Quotient Relational Model of Regions. This model is valid when the light sources illuminate all of the surfaces included in the model; these surfaces are placed close each other, have similar orientations, and are primarily Lambertian. Under certain circumstances, a linear combination is established between the photometric responses of the regions. Previous work that proposed such a relational model was not found in the scientific literature. The second question examines whether those similarities could be used to correct the unknown photometric variations in an unknown region from the known adjacent regions. A method is proposed, called Linear Correction Mapping, which is capable of providing an affirmative answer under the circumstances previously characterised. A training stage is required to determine the parameters of the model. The method for single camera scenarios is extended to cover non-overlapping multi-camera architectures. To this extent, only several image samples of the same object acquired by all of the cameras are required. Furthermore, both the light variations and the changes in the camera exposure settings are covered by correction mapping. Every image correction method is unsuccessful when the image of the object to be corrected is overexposed or the signal-to-noise ratio is very low. Thus, the third question refers to the control of the acquisition process to obtain an optimal exposure in uncontrolled light conditions. A Camera Exposure Control method is proposed that is capable of holding a suitable exposure provided that the light variations can be collected within the dynamic range of the camera. Each one of the proposed methods was evaluated individually. The methodology of the experiments consisted of first selecting some scenarios that cover the representative situations for which the methods are theoretically valid. Linear Correction Mapping was validated using three object re-identification applications (vehicles, faces and persons) based on the object colour distributions. Camera Exposure Control was proved in an outdoor parking scenario. In addition, several performance indicators were defined to objectively compare the results with other relevant state of the art correction and auto-exposure methods. The results of the evaluation demonstrated that the proposed methods outperform the compared ones in the most situations. Based on the obtained results, the answers to the above-described research questions are affirmative in limited circumstances, that is, the hypothesis of the forecasting, the correction based on it, and the auto exposure are feasible in the situations identified in the thesis, although they cannot be guaranteed in general. Furthermore, the presented work raises new questions and scientific challenges, which are highlighted as future research work.

Metodología para el análisis de la relación entre la competividad y la preparación tecnológica en 135 economías mundiales. Factores e indicadores clave de actuación. Conglomerados.

La investigación, plantea como podemos evaluar la competividad en 135 países a partir únicamente de variables tecnológicas. En la metodología se plantea el Protocolo de Cálculo para el total de las economías seleccionadas dentro de los periodos 2005-2006 y 2007-2008, realizando una evaluación estadística. Y estableciendo una discusión, donde analizamos la explicación de las relaciones así como la interpretación de los resultados. Finalmente, evaluamos las conclusiones para las economías mundiales. Dentro de estas economías, localizamos las variables que tienen que priorizarse para mejorar la competividad de las mismas. Estas variables par ten inicialmente de un grupo de 68, y al final de la implementación del método se reducen notablemente. Estas variables finales, llamadas Indicadores Claves de Actuación, se agrupan en factores (Factores Clave de Actuación) que nos simplifican notablemente lo planteado. Para cada grupo de economías se realizan los conglomerados de acuerdo a sus valores dentro de las variables seleccionadas. Se evalúa país a país un análisis detallado de su posicionamiento para cada uno de los Indicadores Claves de Actuación seleccionados matemáticamente. La principal voluntad de la presente información, es simplificar notablemente la comparación entre la competividad de las naciones y su nivel tecnológico. Palabras clave: indicadores, índices, economías, mundiales, análisis multivariante, regresión, factorización, clusterización, análisis de conglomerados, competividad, tecnología, políticas públicas, aspectos regulatorios, operaciones, estrategias comerciales, internet, comparativa cros nacionales, análisis multinivel. Analysis of the relationship between competitiveness and technological development for 135 worldwide countries. Factors and Key Performance Indicators. Clusters of economies Abstract:The research evaluates the competitiveness of 135 countries, based solely on technological variables. The methodology raises calculation protocol for the total of selected economies in the periods 2005-2006 and 2007- 2008. This protocol makes a statistical evaluation. And setting up a discussion, where we analyzed the explanation of the relationship and the interpretation of results. Finally, we evaluate the conclusions for the world economies. Within each group of economies, we know which variables need originally to be prioritized to improve the competitiveness. These variables are from a group of 68, and after the implementation of the method are reduced dramatically in number. These variables will be called Key Performance Indicators and will be grouped into Factors (Key Performance Factors) this will significantly simplify matters. Within this group of countries have been reduced three factors that collect their Key Performance Indicators . A country to country detailed analysis of their positions according to each of the Key Performance Indicators on a mathematical basis.The main desire of this research is to significantly simplify the comparison between the competitiveness of nations and their technological level. Key words: economies, innovation, competitiveness, public policy, business strategies.

Tecnología y competitividad en la economía mundial. Factores e indicadores clave de actuación

Durante los últimos 30 años se han creado una gran cantidad de índices e indicadores para evaluar la práctica totalidad de los países bajo distintas premisas. La tesis parte de un análisis detallado de más de un centenar de estos índices diferenciados entre los enfocados al desarrollo y los enfocados a la competitividad económica (véase Módulo I anexo) y tras esto, dentro del estudio teórico nos hemos centrado en 35 indicadores relacionados con la tecnología (capítulo 3, apartado 3.3.). La justificación, el objetivo de la investigación y la estructura de la tesis se presenta en el capítulo 2. Respecto a la metodología, tal y como se plantea en la hipótesis (apartado 2.2.), se presentan los criterios de selección de seis grupos de países (EP, EPC, EC, ECI, EI y EM)1, que se van a evaluar. Posteriormente se plantea el Protocolo de Cálculo para el total de grupos seleccionados dentro de los periodos 2005-2006 y 2007-2008 y se realiza una profunda evaluación estadística como se plantea dentro de la coherencia estadística explicada en el apartado 3.4.4.5. (también se dispone de los cálculos dentro de los Módulos II, III, IV y V anexos). Tras la metodología establecemos la construcción de un índice sintético NRI(A) y, tras esto, estudiamos las relaciones así como la interpretación de los resultados (capítulo 4, apartado 4.1.). Una vez obtenidos los resultados realizamos la validación de los mismos para el periodo 2007-2015 (capítulo 4 - apartado 4.2. – y los Módulos VI y VII anexos). En el capítulo 5, evaluamos el nivel de preparación tecnológico y su relación con la competitividad para los seis grupos de países (véase desde los apartados 5.1.y 5.2.). Dentro de cada uno de los seis grupos de países, sabemos las variables que cualitativamente tienen que priorizarse para mejorar el nivel de preparación tecnológica de los mismos. Estas variables inicialmente son sesenta y ocho – año 2007-08 –, y al final de la implementación del método se reducen notablemente. Estas variables finales, llamadas Indicadores Clave de Actuación (ICA), se agrupan – vía análisis factorial – en Factores Clave de Actuación que nos simplifican lo planteado. Para cada grupo de países se realizan los conglomerados de acuerdo a sus valores dentro de las ICAs en busca de singularidades y se ha llevado a cabo un análisis minucioso en función de los Indicadores Clave de Actuación. La Tesis, plantea científicamente como podemos evaluar el nivel de preparación tecnológica y su relación con la competitividad, desde un índice sintético creado NRI(A), que contempla únicamente Indicadores Clave de Actuación (variables seleccionadas) a partir de las variables originales del Network Readiness Index (NRI(R)) . Por último se plantea dentro de las conclusiones, capítulo 6, diferentes líneas de investigación, desarrollando dos de ellas que se pueden encontrar en el Modulo VIII anexo. Por un lado presentamos una línea de investigación centrada en 29 economías africanas (EA) de las que disponemos información fidedigna y por otro lado una segunda línea en la que nos centramos en la evaluación de España respecto a sus naciones coetáneas. La principal voluntad de la presente tesis doctoral, es simplificar la evaluación del nivel de preparación tecnológica y la relación de esta con la competitividad a partir de la creación de un índice sintético propio NRI(A). ABSTRACT - During the last 30 years, many institutions have been evaluating and endless range of variables in practically all of the world´s economies. This Thesis is the product of a detail analysis of more than one hundred indicators / index, which we have divided into two parts: those focused on development and those focused on economic competitiveness (see module I annex). Secondly, in our theoretical research we have concentrated on those indicators, which are related to technology (chapters 3, section 3.3). The selection criteria of the six economic groups to be evaluated are included in our methodology, as mentioned in the hypothesis (see section 2.2.). Subsequently the calculation procedure is also presented for all of the groups selected between the periods 2005-2006 and 2007-2008. Next, we perform a statistical study, which is presented accordingly in the segment dealing with statistics, section 3.4.4.5. The calculations are provided in modules I, II, III, IV and V annex. After the methods segment of the Thesis, we develop our argument, in which we presented the explanation of the relations as well as the interpretation of the results. Also at the chapter 4 you can find the result validation from 2007 till 2015. Finally in chapters 6, we evaluate the conclusions for the six economic groups (see section 6.2.). The Thesis scientifically explains the way in which we evaluate economic competitiveness in 135 countries from a standpoint of strictly technological variables. Six groups of countries are evaluated, being divided by criteria, which homogenize the economies under review. We recognize that the variables of each economic group should be prioritized in order to better their competitiveness. Initially the group consisted of 68 variables, a number which was considerably reduced after the implementation of our methodology. Likewise, these final variables, dubbed “key performance indicators”, were grouped into factors (key performance factors), which greatly simplify the prioritization process. At the same time, conglomerates have been created for each economic group according to their value concerning the selected variables. A detailed country – by – country analysis of their positioning in each of the six groups was conducted for each of the mathematically selected key performance indicators. Finally, at the Conclusion we introduce new research lines and between them we focus on two research lines in which ones we are working with (see chapter 6). We basically try to apply the multivariable analysis method, the factorial analysis and the conglomerates to designed and implemented our method first in a geographically group of countries (Africa) and secondly to evaluate and develop the public policies for Spain for the development of its competitively, comparing Spain to his coetaneous countries in Europe (see Module VIII). The main objective of this Doctoral Thesis is to noticeably simplify the comparison of the Network Readiness Index and its relation with the economic competitiveness of the countries using a new synthetic index design by us.

Análise de conflitos de usos múltiplos da água auxiliada por simulação computacional: bacia do rio Sapucaí - Mirim/Grande

Na mesma proporção que fontes de água potável são reduzidas, a competição por elas tem aumentado, conseqüência imediata da expansão de áreas urbanas e de novas demandas agro-industriais. Os conflitos gerados por esta competição tendem a comprometer o desenvolvimento sustentável e o progresso de uma forma geral, uma vez que resultam em perda de eficácia para vultuosos investimentos públicos e privados e em prejuízos para os usuários menos estruturados. Considerando os fatos acima, o objeto deste trabalho é o estabelecimento de cenários de alocação das disponibilidades hídricas entre usuários de água da bacia do Sapucaí-Mirim/Grande, visando determinar a convivência harmoniosa das várias finalidades de uso provenientes do mesmo recurso hídrico. Tal meta poderá ser alcançada através da análise dos indicadores de desempenho - confiabilidade, vulnerabilidade e resiliência - do sistema os quais serão obtidos com o auxílio do modelo de simulação IRAS (Interactive River Aquifer Simulation).

Contribuições ao processo de inserção das PMES no mercado de capitais brasileiro

O crescimento de uma empresa pode ser apoiado com recursos de terceiros provenientes do mercado de crédito ou do mercado de capitais. Credores ou potenciais investidores disponibilizam recursos a partir de um processo de avaliação de indicadores de performance. Para as PMEs que consideram o crescimento, conhecer como os indicadores relevantes se comportam ao longo de um ciclo de crescimento é uma questão estratégica. Fatores como tamanho, lucratividade, oportunidades de crescimento, composição de ativos das empresas, risco inerente aos resultados, têm sido vinculados a determinantes de uma estrutura de capital. Assim sendo, este trabalho busca verificar quais indicadores podem nortear o desempenho empresarial de PMEs ao longo de um ciclo de crescimento. Como contribuição original, este trabalho apresenta um painel com indicadores em diferentes estágios de crescimento que resultam na geração de valor para os proprietários e potenciais investidores do mercado de capitais. A amostra inicial é composta por 1.610 empresas para o período de 2010 a 2014. Entretanto, considerando a disponibilidade de informações, a amostra final é composta por 28 empresas de porte médio/grande, 387 empresas grandes e 138 empresas listadas na BM&FBOVESPA, totalizando 553 empresas. A metodologia adotada envolve a classificação de porte de empresa do BNDES como critério para definir ciclo de crescimento, e testes de estatística descritiva, análise fatorial, análise de correlação, regressão múltipla linear e montagem de painel. Como resultado, verificou-se que as variáveis tamanho, composição de ativos e lucratividade são fatores que explicam o endividamento de curto prazo para o estágio médias/grandes empresas. Ainda, que esses fatores explicam o endividamento de longo prazo para os estágios grandes e empresas listadas na BM&FBOVESPA. Tais resultados estão de acordo com estudos prévios, mas as variáveis relacionadas a volatilidade e crescimento não foram significantes nos modelos para os estágios de empresas. O painel montado a partir das variáveis de composição de ativos e lucratividade indicou que endividamento de curto prazo, endividamento de longo prazo, receita líquida, retorno sobre o patrimônio líquido e lucros antes de juros, impostos, depreciação e amortização (EBITDA) sinalizam empresas, em cada estágio de ciclo de crescimento do estudo, que buscam o crescimento com rentabilidade acima da média e atendem a critérios valorizados pelo investidor do mercado de capitais. Estes indicadores podem sinalizar o desempenho empresarial de PMEs ao longo de um ciclo de crescimento

Oxide Semiconductors For Organic Opto-electronic Devices

Development of transparent oxide semiconductors (TOS) from Earth-abundant materials is of great interest for cost-effective thin film device applications, such as solar cells, light emitting diodes (LEDs), touch-sensitive displays, electronic paper, and transparent thin film transistors. The need of inexpensive or high performance electrode might be even greater for organic photovoltaic (OPV), with the goal to harvest renewable energy with inexpensive, lightweight, and cost competitive materials. The natural abundance of zinc and the wide bandgap ($sim$3.3 eV) of its oxide make it an ideal candidate. In this dissertation, I have introduced various concepts on the modulations of various surface, interface and bulk opto-electronic properties of ZnO based semiconductor for charge transport, charge selectivity and optimal device performance. I have categorized transparent semiconductors into two sub groups depending upon their role in a device. Electrodes, usually 200 to 500 nm thick, optimized for good transparency and transporting the charges to the external circuit. Here, the electrical conductivity in parallel direction to thin film, i.e bulk conductivity is important. And contacts, usually 5 to 50 nm thick, are optimized in case of solar cells for providing charge selectivity and asymmetry to manipulate the built in field inside the device for charge separation and collection. Whereas in Organic LEDs (OLEDs), contacts provide optimum energy level alignment at organic oxide interface for improved charge injections. For an optimal solar cell performance, transparent electrodes are designed with maximum transparency in the region of interest to maximize the light to pass through to the absorber layer for photo-generation, plus they are designed for minimum sheet resistance for efficient charge collection and transport. As such there is need for material with high conductivity and transparency. Doping ZnO with some common elements such as B, Al, Ga, In, Ge, Si, and F result in n-type doping with increase in carriers resulting in high conductivity electrode, with better or comparable opto-electronic properties compared to current industry-standard indium tin oxide (ITO). Furthermore, improvement in mobility due to improvement on crystallographic structure also provide alternative path for high conductivity ZnO TCOs. Implementing these two aspects, various studies were done on gallium doped zinc oxide (GZO) transparent electrode, a very promising indium free electrode. The dynamics of the superimposed RF and DC power sputtering was utilized to improve the microstructure during the thin films growth, resulting in GZO electrode with conductivity greater than 4000 S/cm and transparency greater than 90 %. Similarly, various studies on research and development of Indium Zinc Tin Oxide and Indium Zinc Oxide thin films which can be applied to flexible substrates for next generation solar cells application is presented. In these new TCO systems, understanding the role of crystallographic structure ranging from poly-crystalline to amorphous phase and the influence on the charge transport and optical transparency as well as important surface passivation and surface charge transport properties. Implementation of these electrode based on ZnO on opto-electronics devices such as OLED and OPV is complicated due to chemical interaction over time with the organic layer or with ambient. The problem of inefficient charge collection/injection due to poor understanding of interface and/or bulk property of oxide electrode exists at several oxide-organic interfaces. The surface conductivity, the work function, the formation of dipoles and the band-bending at the interfacial sites can positively or negatively impact the device performance. Detailed characterization of the surface composition both before and after various chemicals treatment of various oxide electrode can therefore provide insight into optimization of device performance. Some of the work related to controlling the interfacial chemistry associated with charge transport of transparent electrodes are discussed. Thus, the role of various pre-treatment on poly-crystalline GZO electrode and amorphous indium zinc oxide (IZO) electrode is compared and contrasted. From the study, we have found that removal of defects and self passivating defects caused by accumulation of hydroxides in the surface of both poly-crystalline GZO and amorphous IZO, are critical for improving the surface conductivity and charge transport. Further insight on how these insulating and self-passivating defects cause charge accumulation and recombination in an device is discussed. With recent rapid development of bulk-heterojunction organic photovoltaics active materials, devices employing ZnO and ZnO based electrode provide air stable and cost-competitive alternatives to traditional inorganic photovoltaics. The organic light emitting diodes (OLEDs) have already been commercialized, thus to follow in the footsteps of this technology, OPV devices need further improvement in power conversion efficiency and stable materials resulting in long device lifetimes. Use of low work function metals such as Ca/Al in standard geometry do provide good electrode for electron collection, but serious problems using low work-function metal electrodes originates from the formation of non-conductive metal oxide due to oxidation resulting in rapid device failure. Hence, using low work-function, air stable, conductive metal oxides such as ZnO as electrons collecting electrode and high work-function, air stable metals such as silver for harvesting holes, has been on the rise. Devices with degenerately doped ZnO functioning as transparent conductive electrode, or as charge selective layer in a polymer/fullerene based heterojunction, present useful device structures for investigating the functional mechanisms within OPV devices and a possible pathway towards improved air-stable high efficiency devices. Furthermore, analysis of the physical properties of the ZnO layers with varying thickness, crystallographic structure, surface chemistry and grain size deposited via various techniques such as atomic layer deposition, sputtering and solution-processed ZnO with their respective OPV device performance is discussed. We find similarity and differences in electrode property for good charge injection in OLEDs and good charge collection in OPV devices very insightful in understanding physics behind device failures and successes. In general, self-passivating surface of amorphous TCOs IZO, ZTO and IZTO forms insulating layer that hinders the charge collection. Similarly, we find modulation of the carrier concentration and the mobility in electron transport layer, namely zinc oxide thin films, very important for optimizing device performance.

Gestión de la calidad y medioambiental y rendimiento empresarial: un análisis de los hoteles españoles

Un tema importante en la literatura sobre calidad es la relación entre la gestión de la calidad y el rendimiento empresarial. Lo mismo ocurre en el campo de la gestión medioambiental. La literatura ha analizado estos sistemas por separado y principalmente en empresas manufactureras. Este estudio analiza conjuntamente ambas prácticas de gestión en el sector hotelero. En concreto, este trabajo identifica los niveles de compromiso con la gestión de la calidad y la gestión ambiental de los hoteles españoles y examina la relación entre el compromiso conjunto con estos sistemas de gestión y el rendimiento empresarial. Los resultados muestran tres tipos de hoteles de acuerdo con su nivel de compromiso con la gestión de la calidad y la gestión ambiental: proactivos, intermedios y reactivos. Además, se ha comprobado que el rendimiento crece conforme mayores son los niveles de compromiso con la gestión de la calidad y el medio ambiente.

A software tool for accurate assessment of costs and CO2 emissions in wood transport using OpenStreetMap©

Costs and environmental impacts are key elements in forest logistics and they must be integrated in forest decision-making. The evaluation of transportation fuel costs and carbon emissions depend on spatial and non-spatial data but in many cases the former type of data are dicult to obtain. On the other hand, the availability of software tools to evaluate transportation fuel consumption as well as costs and emissions of carbon dioxide is limited. We developed a software tool that combines two empirically validated models of truck transportation using Digital Elevation Model (DEM) data and an open spatial data tool, specically OpenStreetMap©. The tool generates tabular data and spatial outputs (maps) with information regarding fuel consumption, cost and CO2 emissions for four types of trucks. It also generates maps of the distribution of transport performance indicators (relation between beeline and real road distances). These outputs can be easily included in forest decision-making support systems. Finally, in this work we applied the tool in a particular case of forest logistics in north-eastern Portugal

European Policy Uses of International Comparisons of Academic Achievement. ACES Working Papers, 2012

International large-scale assessments (ILSAs) and the resulting ranking of countries in key academic subjects have become increasingly significant in the development of global performance indicators and national level reforms in education. As one of the largest international surveys, the Programme for International Student Assessment (PISA) has had a considerable impact on the world of international comparisons of education. Based on the results of these assessments, claims are often made about the relative success or failure of education systems, and in some cases, such as Germany or Japan, ILSAs have sparked national level reforms (Ertl, 2006; Takayama, 2007, 2009). In this paper, I offer an analysis of how PISA is increasingly used as a key reference both for a regional2 entity like the European Union (EU) and for national level performance targets in the example of Spain (Breakspear, 2012). Specifically, the paper examines the growth of OECD and EU initiatives in defining quality education, and the use of both EU benchmarks and PISA in defining the education indicators used in Spain to measure and set goals for developing quality education. By doing so, this paper points to the role of the OECD and the EU in national education systems. It therefore adds to a body of literature pointing to the complex relationship between international, regional, and national education policy spaces (cf. Dale & Robertson, 2002; Lawn & Grek, 2012; Rizvi & Lingard, 2009).

Feasibility of controlling nitrification in predenitrification plants using DO, pH and ORP sensors

Experimental studies were carried out on a bench-scale nitrogen removal system with a predenitrification configuration to gain insights into the spatial and temporal variations of DO, pH and ORP in such systems. It is demonstrated that these signals correlate strongly with the operational states of the system, and could therefore be used as system performance indicators. The DO concentration in the first aerobic zone, when receiving constant aeration, and the net pH change between the last and first aerobic zones display strong correlations with the influent ammonia concentration for the domestic wastewater used in this study. The pH profile along the aerobic zones gives good indication on the extent of nitrification. The experimental results also showed a good correlation between ORP values in the last aerobic zone and effluent ammonia and nitrate concentrations, provided that DO in this zone is controlled at a constant level. These results suggest that the DO, pH and ORP sensors could potentially be used as alternatives to the on-line nutrient sensors for the control of continuous systems. An idea of using a fuzzy inference system to make an integrated use of these signals for on-line aeration control is presented and demonstrated on the bench-scale system with promising results. The use of these sensors has to date only been demonstrated in intermittent systems, such as sequencing batch reactor systems.

Managing innovative manufacturing

Editorial: The Managing Innovative Manufacturing (MIM) conference series started in 1993 in the UK. The first MIM conference was held at Keele University and, as from the second MIM at Leicester University in 1996, it became a biennial event with the University of Nottingham and Aston University hosting, respectively, the third and fourth conferences. The main areas of interest of the MIM conference series are: Manufacturing Strategy; Technology & Innovation Management; Human Resource Management; Organisation of Work; Product Design; Operations Planning and Control; Supply Chain Management; Performance Management. This special issue of the International Journal of Technology Management is based on selected papers from MIM2000 at Aston University, where it was organised by Aston Business School. The special theme of the Aston conference was Responsive Production and the Agile Enterprise. Altogether 82 papers were presented in parallel sessions. The eight papers included here were selected from the ‘Technology and Innovation’ stream. They have all been independently reviewed and revised before being accepted for publication. The authors of these papers are from the UK, Ireland, Turkey, the USA, the Netherlands and Hong Kong. They address a wide range of issues within the overall scope of Technology and Innovation with some papers having a geographical or sector focus and others being more general in nature. Participation in the MIM conferences has become increasingly international and to reflect this, the 2002 event is leaving the UK and being held at the University of Wisconsin-Milwaukee, in the USA. It is planned to hold the following MIM at the University of Aalborg, Denmark, in 2004.