922 resultados para Number development


Relevância:

30.00% 30.00%

Publicador:

Resumo:

The general objective of this work is to analyze the regulatory processes underlying flowering transition and inflorescence and flower development in grapevine. Most of these crucial developmental events take place within buds growing during two seasons in two consecutive years. During the first season, the shoot apical meristem within the bud differentiates all the basic elements of the shoot including flowering transition in lateral primordia and development of inflorescence primordia. These events practically end with bud dormancy. The second season, buds resume shoot growth associated to flower formation and development. In grapevine, the lateral meristems can give rise either to tendril or inflorescence primordia that are homologous organs. With this purpose, we performed global transcriptome analyses along the bud annual cycle and during inflorescence and tendril development. In addition, we approach the genomic analysis of the MIKC type MADS-box gene family in grapevine to identify all its members and assign them putative biological functions. Regarding buds developmental cycle, the results indicate that the main factors explaining the global gene expression differences were the processes of bud dormancy and active growth as well as stress responses. Non dormant buds exhibited up-regulation in functional categories typical of actively proliferating and growing cells (photosynthesis, cell cycle regulation, chromatin assembly) whereas in dormant ones the main functional categories up-regulated were associated to stress response pathways together with transcripts related to starch catabolism. Major transcriptional changes during the dormancy period were associated to the para/endodormancy, endo/ecodormancy and ecodormancy/bud break transitions. Global transcriptional analyses along tendril and inflorescence development suggested that these two homologous organs share a common transcriptional program related to cell proliferation functions. Both structures showed a progressive decrease in the expression of categories such as cell-cycle, auxin metabolism/signaling, DNA metabolism, chromatin assembly and a cluster of five transcripts belonging to the GROWTH-REGULATING FACTOR (GRF) transcription factor family, that are known to control cell proliferation in other species and determine the size of lateral organs. However, they also showed organ specific transcriptional programs that can be related to their differential organ structure and function. Tendrils showed higher transcription of genes related to photosynthesis, hormone signaling and secondary metabolism than inflorescences, while inflorescences have higher transcriptional activity for genes encoding transcription factors (especially those belonging to the MADS-box gene family). Further analysis along inflorescence development evidenced the relevance of additional functions likely related to processes of flower development such as fatty acid and lipid metabolism, jasmonate signaling and oxylipin biosynthesis. The transcriptional analyses performed highlighted the relevance of several groups of transcriptional regulators in the developmental processes studied. The expression profiles along bud development revealed significant differences for some MADS-box subfamilies in relation to other plant species, like the members of the FLC and SVP subfamilies suggesting new roles for these groups in grapevine. In this way, it was found that VvFLC2 and VvAGL15.1 could participate, together with some members of the SPL-L family, in dormancy regulation, as was shown for some of them in other woody plants. Similarly, the expression patterns of the VvFLC1, VvFUL, VvSOC1.1 (together with VvFT, VvMFT1 and VFL) genes could indicate that they play a role in flowering transition in grapevine, in parallel to their roles in other plant systems. The expression levels of VFL, the grapevine LEAFY homolog, could be crucial to specify the development of inflorescence and flower meristems instead of tendril meristems. MADS-box genes VvAP3.1 and 2, VvPI, VvAG1 and 3, VvSEP1-4, as well as VvBS1 and 2 are likely associated with the events of flower meristems and flower organs differentiation, while VvAP1 and VvFUL-L (together with VvSOC1.1, VvAGL6.2) could be involved on tendril development given their expression patterns. In addition, the biological function ofVvAP1 and VvTFL1A was analyzed using a gene silencing approach in transgenic grapevine plants. Our preliminary results suggested a possible role for both genes in the initiation and differentiation of tendrils. Finally, the genomic analysis of the MADS-box gene family in grapevine revealed differential features regarding number and expression pattern of genes putatively involved in the flowering transition process as compared to those involved in the specification of flower and fruit organ identity. Altogether, the results obtained allow identifying putative candidate genes and pathways regulating grapevine reproductive developmental processes paving the way to future experiments demonstrating specific gene biological functions. RESUMEN El objetivo general de este trabajo es analizar los procesos regulatorios subyacentes a la inducción floral así como al desarrollo de la inflorescencia y la flor en la vid. La mayor parte de estos eventos cruciales tienen lugar en las yemas a lo largo de dos estaciones de crecimiento consecutivas. Durante la primera estación, el meristemo apical contenido en la yema diferencia los elementos básicos del pámpano, lo cual incluye la inducción de la floración en los meristemos laterales y el subsiguiente desarrollo de primordios de inflorescencia. Estos procesos prácticamente cesan con la entrada en dormición de la yema. En la segunda estación, se reanuda el crecimiento del pámpano acompañado por la formación y desarrollo de las flores. En la vid, los meristemos laterales pueden dar lugar a primordios de inflorescencia o de zarcillo que son considerados órganos homólogos. Con este objetivo llevamos a cabo un estudio a nivel del transcriptoma de la yema a lo largo de su ciclo anual, así como a lo largo del desarrollo de la inflorescencia y del zarcillo. Además realizamos un análisis genómico de la familia MADS de factores transcripcionales (concretamente aquellos del tipo MIKC) para identificar todos sus miembros y tratar de asignarles posibles funciones biológicas. En cuanto al ciclo de desarrollo de la yema, los resultados indican que los principales factores que explican las diferencias globales en la expresión génica fueron los procesos de dormición de la yema y el crecimiento activo junto con las respuestas a diversos tipos de estrés. Las yemas no durmientes mostraron un incremento en la expresión de genes contenidos en categorías funcionales típicas de células en proliferación y crecimiento activo (como fotosíntesis, regulación del ciclo celular, ensamblaje de cromatina), mientras que en las yemas durmientes, las principales categorías funcionales activadas estaban asociadas a respuestas a estrés, así como con el catabolismo de almidón. Los mayores cambios observados a nivel de transcriptoma en la yema coincidieron con las transiciones de para/endodormición, endo/ecodormición y ecodormición/brotación. Los análisis transcripcionales globales a lo largo del desarrollo del zarcillo y de la inflorescencia sugirieron que estos dos órganos homólogos comparten un programa transcripcional común, relacionado con funciones de proliferación celular. Ambas estructuras mostraron un descenso progresivo en la expresión de genes pertenecientes a categorías funcionales como regulación del ciclo celular, metabolismo/señalización por auxinas, metabolismo de ADN, ensamblaje de cromatina y un grupo de cinco tránscritos pertenecientes a la familia de factores transcripcionales GROWTH-REGULATING FACTOR (GRF), que han sido asociados con el control de la proliferación celular y en determinar el tamaño de los órganos laterales en otras especies. Sin embargo, también pusieron de manifiesto programas transcripcionales que podrían estar relacionados con la diferente estructura y función de dichos órganos. Los zarcillos mostraron mayor actividad transcripcional de genes relacionados con fotosíntesis, señalización hormonal y metabolismo secundario que las inflorescencias, mientras que éstas presentaron mayor actividad transcripcional de genes codificantes de factores de transcripción (especialmente los pertenecientes a la familia MADS-box). Análisis adicionales a lo largo del desarrollo de la inflorescencia evidenciaron la relevancia de otras funciones posiblemente relacionadas con el desarrollo floral, como el metabolismo de lípidos y ácidos grasos, la señalización mediada por jasmonato y la biosíntesis de oxilipinas. Los análisis transcripcionales llevados a cabo pusieron de manifiesto la relevancia de varios grupos de factores transcripcionales en los procesos estudiados. Los perfiles de expresión estudiados a lo largo del desarrollo de la yema mostraron diferencias significativas en algunas de las subfamilias de genes MADS con respecto a otras especies vegetales, como las observadas en los miembros de las subfamilias FLC y SVP, lo cual sugiere que podrían desempeñar nuevas funciones en la vid. En este sentido, se encontró que los genes VvFLC2 y VvAGL15.1 podrían participar, junto con algunos miembros de la familia SPL-L, en la regulación de la dormición. De un modo similar, los patrones de expresión de los genes VvFLC1, VvFUL, VvSOC1.1 (junto con VvFT, VvMFT1 y VFL) podría indicar que desempeñan un papel en la regulación de la inducción de la floración en la vid, como se ha observado en otros sistemas vegetales. Los niveles de expresión de VFL, el homólogo en vid del gen LEAFY de A. thaliana podrían ser cruciales para la especificación del desarrollo de meristemos de inflorescencia y flor en lugar de meristemos de zarcillo. Los genes VvAP3.1 y 2, VvPI, VvAG1 y 3, VvSEP1-4, así como VvBS1 y 2 parecen estar asociados con los eventos de diferenciación de meristemos y órganos florales, mientras que VvAP1 y VvFUL-L (junto con VvSOC1.1 y VvAGL6.2) podrían estar implicados en el desarrollo del zarcillo dados sus patrones de expresión. Adicionalmente, se analizó la función biológica de los genes VvAP1 y VvTFL1A por medio de una estrategia de silenciamiento génico. Los datos preliminares sugieren un posible papel para ambos genes en la iniciación y diferenciación de los zarcillos. Finalmente, el análisis genómico de la familia MADS en vid evidenció diferencias con respecto a otras especies vegetales en cuanto a número de miembros y patrón de expresión en genes supuestamente implicados en la inducción de la floración, en comparación con aquellos relacionados con la especificación de identidad de órganos florales y desarrollo del fruto. En conjunto, los resultados obtenidos han permitido identificar posibles rutas y genes candidatos a participar en la regulación de los procesos de desarrollo reproductivo de la vid, sentando las bases de futuros experimentos encaminados a conocer la funciones biológicas de genes específicos.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

End-user development (EUD) is much hyped, and its impact has outstripped even the most optimistic forecasts. Even so, the vision of end users programming their own solutions has not yet materialized. This will continue to be so unless we in both industry and the research community set ourselves the ambitious challenge of devising end to end an end-user application development model for developing a new age of EUD tools. We have embarked on this venture, and this paper presents the main insights and outcomes of our research and development efforts as part of a number of successful EU research projects. Our proposal not only aims to reshape software engineering to meet the needs of EUD but also to refashion its components as solution building blocks instead of programs and software developments. This way, end users will really be empowered to build solutions based on artefacts akin to their expertise and understanding of ideal solutions

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The paper presents the main elements of a project entitled ICT-Emissions that aims at developing a novel methodology to evaluate the impact of ICT-related measures on mobility, vehicle energy consumption and CO2 emissions of vehicle fleets at the local scale, in order to promote the wider application of the most appropriate ICT measures. The proposed methodology combines traffic and emission modelling at micro and macro scales. These will be linked with interfaces and submodules which will be specifically designed and developed. A number of sources are available to the consortium to obtain the necessary input data. Also, experimental campaigns are offered to fill in gaps of information in traffic and emission patterns. The application of the methodology will be demonstrated using commercially available software. However, the methodology is developed in such a way as to enable its implementation by a variety of emission and traffic models. Particular emphasis is given to (a) the correct estimation of driver behaviour, as a result of traffic-related ICT measures, (b) the coverage of a large number of current vehicle technologies, including ICT systems, and (c) near future technologies such as hybrid, plug-in hybrids, and electric vehicles. The innovative combination of traffic, driver, and emission models produces a versatile toolbox that can simulate the impact on energy and CO2 of infrastructure measures (traffic management, dynamic traffic signs, etc.), driver assistance systems and ecosolutions (speed/cruise control, start/stop systems, etc.) or a combination of measures (cooperative systems).The methodology is validated by application in the Turin area and its capacity is further demonstrated by application in real world conditions in Madrid and Rome.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

tWatercore distribution inside apple fruit (block or radial), and its incidence (% of tissue) were relatedto the effect of solar radiation inside the canopy as measured by a set of low-cost irradiation sensors.221 samples were harvested in two seasons from the top and the bottom of the canopy and submittedto the non-invasive and non-destructive technique of magnetic resonance imaging (MRI) in order toobtain 20 inner tomography slices from each fruit and analyze the damaged areas using an interactive3D segmentation method. The number of fruit corresponding to each type of damage and the relevantpercentage were calculated and it was found that apples from the top of the tree were mainly of the radialtype (84%) and had more watercore (approx. 5% more) than apples from the bottom (65% radial). From theimage segmentation, the Euler number, a morphometric parameter, was extracted from the segmentedimages and related to the type of watercore symptoms. Apples with block watercore were grouped inEuler numbers between −400 and 400 with a small evolution. For apples with radial development, theEuler number was highly negative: up to −1439. Significant differences were also found regarding sugarcomposition, with higher fructose and total sugar contents in apples from the upper canopy, compared tothose in the lower canopy location. In the seasons studied (2011 and 2012), significantly higher sorbitoland lower sucrose and fructose contents were found in watercore-affected tissue compared to the healthytissue of affected apples and also compared to healthy apples.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Modeling is an essential tool for the development of atmospheric emission abatement measures and air quality plans. Most often these plans are related to urban environments with high emission density and population exposure. However, air quality modeling in urban areas is a rather challenging task. As environmental standards become more stringent (e.g. European Directive 2008/50/EC), more reliable and sophisticated modeling tools are needed to simulate measures and plans that may effectively tackle air quality exceedances, common in large urban areas across Europe, particularly for NO2. This also implies that emission inventories must satisfy a number of conditions such as consistency across the spatial scales involved in the analysis, consistency with the emission inventories used for regulatory purposes and versatility to match the requirements of different air quality and emission projection models. This study reports the modeling activities carried out in Madrid (Spain) highlighting the atmospheric emission inventory development and preparation as an illustrative example of the combination of models and data needed to develop a consistent air quality plan at urban level. These included a series of source apportionment studies to define contributions from the international, national, regional and local sources in order to understand to what extent local authorities can enforce meaningful abatement measures. Moreover, source apportionment studies were conducted in order to define contributions from different sectors and to understand the maximum feasible air quality improvement that can be achieved by reducing emissions from those sectors, thus targeting emission reduction policies to the most relevant activities. Finally, an emission scenario reflecting the effect of such policies was developed and the associated air quality was modeled.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This research addressed the development of a consolidated model designed especially to cover the security and usability attributes of a software product. As a starting point, we built a new usability model on the basis of well-known quality standards and models. We then used an existing security model to analyse the relationship between these two approaches. This analysis consisted of a systematic mapping study of the relationship between security and usability as global quality factors. We identified five relationship types: inverse, direct, relative, one-way inverse, and no relationship. Most authors agree that there is an inverse relationship between security and usability. However, this is not a unanimous finding, and this study unveils a number of open questions, like application domain dependency and the need to explore lower-level relationships between attribute subcharacteristics. In order to clarify the questions raised during the research, we conducted a second systematic mapping to further analyse the finer-grained structure of these factors, such as authentication as a subset of security and user efficiency as a subset of usability. The most relevant finding is that efficiency does not depend on the security level during the authentication process. There are other subfactors that require analysis. Accordingly, this research is the first part of a larger project to develop a full-blown consolidated model for security and usability.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Changing factors (mainly traffic intensity and weather conditions) affecting road conditions require a suitable optimal speed at any time. To solve this problem, variable speed limit systems (VSL) ? as opposed to fixed limits ? have been developed in recent decades. This term has included a number of speed management systems, most notably dynamic speed limits (DSL). In order to avoid the indiscriminate use of both terms in the literature, this paper proposes a simple classification and offers a review of some experiences, how their effects are evaluated and their results This study also presents a key indicator, which measures the speed homogeneity and a methodology to obtain the data based on floating cars and GPS technology applying it to a case study on a section of the M30 urban motorway in Madrid (Spain).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The project arises from the need to develop improved teaching methodologies in field of the mechanics of continuous media. The objective is to offer the student a learning process to acquire the necessary theoretical knowledge, cognitive skills and the responsibility and autonomy to professional development in this area. Traditionally the teaching of the concepts of these subjects was performed through lectures and laboratory practice. During these lessons the students attitude was usually passive, and therefore their effectiveness was poor. The proposed methodology has already been successfully employed in universities like University Bochum, Germany, University the South Australia and aims to improve the effectiveness of knowledge acquisition through use by the student of a virtual laboratory. This laboratory allows to adapt the curricula and learning techniques to the European Higher Education and improve current learning processes in the University School of Public Works Engineers -EUITOP- of the Technical University of Madrid -UPM-, due there are not laboratories in this specialization. The virtual space is created using a software platform built on OpenSim, manages 3D virtual worlds, and, language LSL -Linden Scripting Language-, which imprints specific powers to objects. The student or user can access this virtual world through their avatar -your character in the virtual world- and can perform practices within the space created for the purpose, at any time, just with computer with internet access and viewfinder. The virtual laboratory has three partitions. The virtual meeting rooms, where the avatar can interact with peers, solve problems and exchange existing documentation in the virtual library. The interactive game room, where the avatar is has to resolve a number of issues in time. And the video room where students can watch instructional videos and receive group lessons. Each audiovisual interactive element is accompanied by explanations framing it within the area of knowledge and enables students to begin to acquire a vocabulary and practice of the profession for which they are being formed. Plane elasticity concepts are introduced from the tension and compression testing of test pieces of steel and concrete. The behavior of reticulated and articulated structures is reinforced by some interactive games and concepts of tension, compression, local and global buckling will by tests to break articulated structures. Pure bending concepts, simple and composite torsion will be studied by observing a flexible specimen. Earthquake resistant design of buildings will be checked by a laboratory test video.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The potential shown by Lean in different domains has aroused interest in the software industry. However, it remains unclear how Lean can be effectively applied in a domain such as software development that is fundamentally different from manufacturing. This study explores how Lean principles are implemented in software development companies and the challenges that arise when applying Lean Software Development. For that, a case study was conducted at Ericsson R&D Finland, which successfully adopted Scrum in 2009 and subsequently started a comprehensible transition to Lean in 2010. Focus groups were conducted with company representatives to help devise a questionnaire supporting the creation of a Lean mindset in the company (Team Amplifier). Afterwards, the questionnaire was used in 16 teams based in Finland, Hungary and China to evaluate the status of the transformation. By using Lean thinking, Ericsson R&D Finland has made important improvements to the quality of its products, customer satisfaction and transparency within the organization. Moreover, build times have been reduced over ten times and the number of commits per day has increased roughly five times.The study makes two main contributions to research. First, the main factors that have enabled Ericsson R&D?s achievements are analysed. Elements such as ?network of product owners?, ?continuous integration?, ?work in progress limits? and ?communities of practice? have been identified as being of fundamental importance. Second, three categories of challenges in using Lean Software Development were identified: ?achieving flow?, ?transparency? and ?creating a learning culture?

Relevância:

30.00% 30.00%

Publicador:

Resumo:

El mercado ibérico de futuros de energía eléctrica gestionado por OMIP (“Operador do Mercado Ibérico de Energia, Pólo Português”, con sede en Lisboa), también conocido como el mercado ibérico de derivados de energía, comenzó a funcionar el 3 de julio de 2006. Se analiza la eficiencia de este mercado organizado, por lo que se estudia la precisión con la que sus precios de futuros predicen el precio de contado. En dicho mercado coexisten dos modos de negociación: el mercado continuo (modo por defecto) y la contratación mediante subasta. En la negociación en continuo, las órdenes anónimas de compra y de venta interactúan de manera inmediata e individual con órdenes contrarias, dando lugar a operaciones con un número indeterminado de precios para cada contrato. En la negociación a través de subasta, un precio único de equilibrio maximiza el volumen negociado, liquidándose todas las operaciones a ese precio. Adicionalmente, los miembros negociadores de OMIP pueden liquidar operaciones “Over-The-Counter” (OTC) a través de la cámara de compensación de OMIP (OMIClear). Las cinco mayores empresas españolas de distribución de energía eléctrica tenían la obligación de comprar electricidad hasta julio de 2009 en subastas en OMIP, para cubrir parte de sus suministros regulados. De igual manera, el suministrador de último recurso portugués mantuvo tal obligación hasta julio de 2010. Los precios de equilibrio de esas subastas no han resultado óptimos a efectos retributivos de tales suministros regulados dado que dichos precios tienden a situarse ligeramente sesgados al alza. La prima de riesgo ex-post, definida como la diferencia entre los precios a plazo y de contado en el periodo de entrega, se emplea para medir su eficiencia de precio. El mercado de contado, gestionado por OMIE (“Operador de Mercado Ibérico de la Energía”, conocido tradicionalmente como “OMEL”), tiene su sede en Madrid. Durante los dos primeros años del mercado de futuros, la prima de riesgo media tiende a resultar positiva, al igual que en otros mercados europeos de energía eléctrica y gas natural. En ese periodo, la prima de riesgo ex-post tiende a ser negativa en los mercados de petróleo y carbón. Los mercados de energía tienden a mostrar niveles limitados de eficiencia de mercado. La eficiencia de precio del mercado de futuros aumenta con el desarrollo de otros mecanismos coexistentes dentro del mercado ibérico de electricidad (conocido como “MIBEL”) –es decir, el mercado dominante OTC, las subastas de centrales virtuales de generación conocidas en España como Emisiones Primarias de Energía, y las subastas para cubrir parte de los suministros de último recurso conocidas en España como subastas CESUR– y con una mayor integración de los mercados regionales europeos de energía eléctrica. Se construye un modelo de regresión para analizar la evolución de los volúmenes negociados en el mercado continuo durante sus cuatro primeros años como una función de doce indicadores potenciales de liquidez. Los únicos indicadores significativos son los volúmenes negociados en las subastas obligatorias gestionadas por OMIP, los volúmenes negociados en el mercado OTC y los volúmenes OTC compensados por OMIClear. El número de creadores de mercado, la incorporación de agentes financieros y compañías de generación pertenecientes a grupos integrados con suministradores de último recurso, y los volúmenes OTC compensados por OMIClear muestran una fuerte correlación con los volúmenes negociados en el mercado continuo. La liquidez de OMIP está aún lejos de los niveles alcanzados por los mercados europeos más maduros (localizados en los países nórdicos (Nasdaq OMX Commodities) y Alemania (EEX)). El operador de mercado y su cámara de compensación podrían desarrollar acciones eficientes de marketing para atraer nuevos agentes activos en el mercado de contado (p.ej. industrias consumidoras intensivas de energía, suministradores, pequeños productores, compañías energéticas internacionales y empresas de energías renovables) y agentes financieros, captar volúmenes del opaco OTC, y mejorar el funcionamiento de los productos existentes aún no líquidos. Resultaría de gran utilidad para tales acciones un diálogo activo con todos los agentes (participantes en el mercado, operador de mercado de contado, y autoridades supervisoras). Durante sus primeros cinco años y medio, el mercado continuo presenta un crecimento de liquidez estable. Se mide el desempeño de sus funciones de cobertura mediante la ratio de posición neta obtenida al dividir la posición abierta final de un contrato de derivados mensual entre su volumen acumulado en la cámara de compensación. Los futuros carga base muestran la ratio más baja debido a su buena liquidez. Los futuros carga punta muestran una mayor ratio al producirse su menor liquidez a través de contadas subastas fijadas por regulación portuguesa. Las permutas carga base liquidadas en la cámara de compensación ubicada en Madrid –MEFF Power, activa desde el 21 de marzo de 2011– muestran inicialmente valores altos debido a bajos volúmenes registrados, dado que esta cámara se emplea principalmente para vencimientos pequeños (diario y semanal). Dicha ratio puede ser una poderosa herramienta de supervisión para los reguladores energéticos cuando accedan a todas las transacciones de derivados en virtud del Reglamento Europeo sobre Integridad y Transparencia de los Mercados de Energía (“REMIT”), en vigor desde el 28 de diciembre de 2011. La prima de riesgo ex-post tiende a ser positiva en todos los mecanismos (futuros en OMIP, mercado OTC y subastas CESUR) y disminuye debido a la curvas de aprendizaje y al efecto, desde el año 2011, del precio fijo para la retribución de la generación con carbón autóctono. Se realiza una comparativa con los costes a plazo de generación con gas natural (diferencial “clean spark spread”) obtenido como la diferencia entre el precio del futuro eléctrico y el coste a plazo de generación con ciclo combinado internalizando los costes de emisión de CO2. Los futuros eléctricos tienen una elevada correlación con los precios de gas europeos. Los diferenciales de contratos con vencimiento inmediato tienden a ser positivos. Los mayores diferenciales se dan para los contratos mensuales, seguidos de los trimestrales y anuales. Los generadores eléctricos con gas pueden maximizar beneficios con contratos de menor vencimiento. Los informes de monitorización por el operador de mercado que proporcionan transparencia post-operacional, el acceso a datos OTC por el regulador energético, y la valoración del riesgo regulatorio pueden contribuir a ganancias de eficiencia. Estas recomendaciones son también válidas para un potencial mercado ibérico de futuros de gas, una vez que el hub ibérico de gas –actualmente en fase de diseño, con reuniones mensuales de los agentes desde enero de 2013 en el grupo de trabajo liderado por el regulador energético español– esté operativo. El hub ibérico de gas proporcionará transparencia al atraer más agentes y mejorar la competencia, incrementando su eficiencia, dado que en el mercado OTC actual no se revela precio alguno de gas. ABSTRACT The Iberian Power Futures Market, managed by OMIP (“Operador do Mercado Ibérico de Energia, Pólo Português”, located in Lisbon), also known as the Iberian Energy Derivatives Market, started operations on 3 July 2006. The market efficiency, regarding how well the future price predicts the spot price, is analysed for this energy derivatives exchange. There are two trading modes coexisting within OMIP: the continuous market (default mode) and the call auction. In the continuous trading, anonymous buy and sell orders interact immediately and individually with opposite side orders, generating trades with an undetermined number of prices for each contract. In the call auction trading, a single price auction maximizes the traded volume, being all trades settled at the same price (equilibrium price). Additionally, OMIP trading members may settle Over-the-Counter (OTC) trades through OMIP clearing house (OMIClear). The five largest Spanish distribution companies have been obliged to purchase in auctions managed by OMIP until July 2009, in order to partly cover their portfolios of end users’ regulated supplies. Likewise, the Portuguese last resort supplier kept that obligation until July 2010. The auction equilibrium prices are not optimal for remuneration purposes of regulated supplies as such prices seem to be slightly upward biased. The ex-post forward risk premium, defined as the difference between the forward and spot prices in the delivery period, is used to measure its price efficiency. The spot market, managed by OMIE (Market Operator of the Iberian Energy Market, Spanish Pool, known traditionally as “OMEL”), is located in Madrid. During the first two years of the futures market, the average forward risk premium tends to be positive, as it occurs with other European power and natural gas markets. In that period, the ex-post forward risk premium tends to be negative in oil and coal markets. Energy markets tend to show limited levels of market efficiency. The price efficiency of the Iberian Power Futures Market improves with the market development of all the coexistent forward contracting mechanisms within the Iberian Electricity Market (known as “MIBEL”) – namely, the dominant OTC market, the Virtual Power Plant Auctions known in Spain as Energy Primary Emissions, and the auctions catering for part of the last resort supplies known in Spain as CESUR auctions – and with further integration of European Regional Electricity Markets. A regression model tracking the evolution of the traded volumes in the continuous market during its first four years is built as a function of twelve potential liquidity drivers. The only significant drivers are the traded volumes in OMIP compulsory auctions, the traded volumes in the OTC market, and the OTC cleared volumes by OMIClear. The amount of market makers, the enrolment of financial members and generation companies belonging to the integrated group of last resort suppliers, and the OTC cleared volume by OMIClear show strong correlation with the traded volumes in the continuous market. OMIP liquidity is still far from the levels reached by the most mature European markets (located in the Nordic countries (Nasdaq OMX Commodities) and Germany (EEX)). The market operator and its clearing house could develop efficient marketing actions to attract new entrants active in the spot market (e.g. energy intensive industries, suppliers, small producers, international energy companies and renewable generation companies) and financial agents as well as volumes from the opaque OTC market, and to improve the performance of existing illiquid products. An active dialogue with all the stakeholders (market participants, spot market operator, and supervisory authorities) will help to implement such actions. During its firs five and a half years, the continuous market shows steady liquidity growth. The hedging performance is measured through a net position ratio obtained from the final open interest of a month derivatives contract divided by its accumulated cleared volume. The base load futures in the Iberian energy derivatives exchange show the lowest ratios due to good liquidity. The peak futures show bigger ratios as their reduced liquidity is produced by auctions fixed by Portuguese regulation. The base load swaps settled in the clearing house located in Spain – MEFF Power, operating since 21 March 2011, with a new denomination (BME Clearing) since 9 September 2013 – show initially large values due to low registered volumes, as this clearing house is mainly used for short maturity (daily and weekly swaps). The net position ratio can be a powerful oversight tool for energy regulators when accessing to all the derivatives transactions as envisaged by European regulation on Energy Market Integrity and Transparency (“REMIT”), in force since 28 December 2011. The ex-post forward risk premium tends to be positive in all existing mechanisms (OMIP futures, OTC market and CESUR auctions) and diminishes due to the learning curve and the effect – since year 2011 – of the fixed price retributing the indigenous coal fired generation. Comparison with the forward generation costs from natural gas (“clean spark spread”) – obtained as the difference between the power futures price and the forward generation cost with a gas fired combined cycle plant taking into account the CO2 emission rates – is also performed. The power futures are strongly correlated with European gas prices. The clean spark spreads built with prompt contracts tend to be positive. The biggest clean spark spreads are for the month contract, followed by the quarter contract and then by the year contract. Therefore, gas fired generation companies can maximize profits trading with contracts of shorter maturity. Market monitoring reports by the market operator providing post-trade transparency, OTC data access by the energy regulator, and assessment of the regulatory risk can contribute to efficiency gains. The same recommendations are also valid for a potential Iberian gas futures market, once an Iberian gas hub – currently in a design phase, with monthly meetings amongst the stakeholders in a Working Group led by the Spanish energy regulatory authority since January 2013 – is operating. The Iberian gas hub would bring transparency attracting more shippers and improving competition and thus its efficiency, as no gas price is currently disclosed in the existing OTC market.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In the field of dimensional metrology, the use of optical measuring machines requires the handling of a large number of measurement points, or scanning points, taken from the image of the measurand. The presence of correlation between these measurement points has a significant influence on the uncertainty of the result. The aim of this work is the development of an estimation procedure for the uncertainty of measurement in a geometrically elliptical shape, taking into account the correlation between the scanning points. These points are obtained from an image produced using a commercial flat bed scanner. The characteristic parameters of the ellipse (coordinates of the center, semi-axes and the angle of the semi-major axis with regard to the horizontal) are determined using a least squares fit and orthogonal distance regression. The uncertainty is estimated using the information from the auto-correlation function of the residuals and is propagated through the fitting algorithm according to the rules described in Evaluation of Measurement Data—Supplement 2 to the ‘Guide to the Expression of Uncertainty in Measurement’—Extension to any number of output quantities. By introducing the concept of cut-off length, it can be observed how it is possible to take into account the presence of the correlation in the estimation of uncertainty in a very simple way while avoiding underestimation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In recent years, the concept of sustainable development has become increasingly recognized and important. Within organizations, sustainable development is often portrayed as a balancing act, and requires a combination of three elements to be considered: economy, environment, and society. Traditionally, organizational management research has been focused on economical and environmental fronts. However, social aspects are also important for organizations, especially those in emerging and developing countries. The goal of this paper is to investigate the potential of Clean Development Mechanism (CDM) projects to deliver social benefits in Brazil?s hydroelectricity sector. The investigation involved the assessment of 46 registered hydro CDM projects under the Kyoto Protocol in terms of their potential impact on the envisaged social development goals. Two case studies were also examined. Results indicate that organizations managing hydroelectric initiatives in Brazil can provide the pathway towards achieving a number of important social benefits. Successful projects were found to have good community involvement and were managed by both cooperative ventures and money making corporations. The research also identified several challenges that are hindering hydro CDM projects from delivering more social benefits, and enabled a number of recommendations to be extracted for the organizations facing these challenges.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

La adquisición de la competencia grupal es algo básico en la docencia universitaria. Esta tarea va a suponer evaluar diferentes factores en un número elevado de alumnos, lo que puede supone gran complejidad y un esfuerzo elevado. De cara a evitar este esfuerzo se puede pensar en emplear los registros de la interacción de los usuarios almacenados en las plataformas de aprendizaje. Para ello el presente trabajo se basa en el desarrollo de un sistema de Learning Analytics que es utilizado como herramienta para analizar las evidencias individuales de los distintos miembros de un equipo de trabajo. El trabajo desarrolla un modelo teórico apoyado en la herramienta, que permite relacionar las evidencias observadas de forma empírica para cada alumno, con indicadores obtenidos tanto de la acción individual como cooperativo de los miembros de un equipo realizadas a través de los foros de trabajo. Abstract — The development of the group work competence is something basic in university teaching. It should be evaluated, but this means to analyze different issues about the participation of a high number of students which is very complex and implies a lot of effort. In order to facilitate this evaluation it is possible to analyze the logs of students’ interaction in Learning Management Systems. The present work describes the development of a Learning Analytics system that analyzes the interaction of each of the members of working group. This tool is supported by a theoretical model, which allows establishing links between the empirical evidences of each student and the indicators of their action in working forums.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This document contains detailed description of the design and the implementation of a multi-agent application controlling traffic lights in a city together with a system for simulating traffic and testing. The goal of this thesis is to design and build a simplified intelligent and distributed solution to the problem with the traffic in the big cities following different good practices in order to allow future refining of the model of the real world. The problem of the traffic in the big cities is still a problem that cannot be solved. Not only is the increasing number of cars a reason for the traffic jams, but also the way the traffic is organized. Usually, the intersections with traffic lights are replaced by roundabouts or interchanges to increase the number of cars that can cross the intersection in certain time. But still there are places where the infrastructure cannot be changed and the traffic light semaphores are the only way to control the car flows. In real life, the traffic lights have a predefined plan for change or they receive information from a centralized system when and how they have to change. But what if the traffic lights can cooperate and decide on their own when and how to change? Using this problem, the purpose of the thesis is to explore different agent-based software engineering approaches to design and build a non-conventional distributed system. From the software engineering point of view, the goal of the thesis is to apply the knowledge and use the skills, acquired during the various courses of the master program in Software Engineering, while solving a practical and complex problem such as the traffic in the cities.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Automated Teller Machines (ATMs) are sensitive self-service systems that require important investments in security and testing. ATM certifications are testing processes for machines that integrate software components from different vendors and are performed before their deployment for public use. This project was originated from the need of optimization of the certification process in an ATM manufacturing company. The process identifies compatibility problems between software components through testing. It is composed by a huge number of manual user tasks that makes the process very expensive and error-prone. Moreover, it is not possible to fully automate the process as it requires human intervention for manipulating ATM peripherals. This project presented important challenges for the development team. First, this is a critical process, as all the ATM operations rely on the software under test. Second, the context of use of ATMs applications is vastly different from ordinary software. Third, ATMs’ useful lifetime is beyond 15 years and both new and old models need to be supported. Fourth, the know-how for efficient testing depends on each specialist and it is not explicitly documented. Fifth, the huge number of tests and their importance implies the need for user efficiency and accuracy. All these factors led us conclude that besides the technical challenges, the usability of the intended software solution was critical for the project success. This business context is the motivation of this Master Thesis project. Our proposal focused in the development process applied. By combining user-centered design (UCD) with agile development we ensured both the high priority of usability and the early mitigation of software development risks caused by all the technology constraints. We performed 23 development iterations and finally we were able to provide a working solution on time according to users’ expectations. The evaluation of the project was carried out through usability tests, where 4 real users participated in different tests in the real context of use. The results were positive, according to different metrics: error rate, efficiency, effectiveness, and user satisfaction. We discuss the problems found, the benefits and the lessons learned in the process. Finally, we measured the expected project benefits by comparing the effort required by the current and the new process (once the new software tool is adopted). The savings corresponded to 40% less effort (man-hours) per certification. Future work includes additional evaluation of product usability in a real scenario (with customers) and the measuring of benefits in terms of quality improvement.