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Imagen de apoyo de  ISA-88 modeling and fault diagnosis of irrigation control systems = Modelización ISA-88 y diagnóstico de fallos en sistemas control de riego

ISA-88 modeling and fault diagnosis of irrigation control systems = Modelización ISA-88 y diagnóstico de fallos en sistemas control de riego

Por: Liz Johanna Peña Rincón | Fecha: 01/01/2010

Actualmente los sistemas de control de riego SCADA son diseñados con modelos y protocolos que dependen exclusivamente de cada fabricante. Si se requiere una interoperabilidad a nivel de programación de riegos y estado real de actuadores y sensores, con algún sistema de gestión que no sea del mismo fabricante, significa una alta inversión económica y tecnológica, que en la mayoría de casos no es posible realizar. Adicionalmente los mecanismos de diagnóstico de fallos actuales, no permiten determinar los fallos que se presentan en los sensores, lo cual se vuelve crítico cuando se presenta una anomalía en el sistema y no se puede cumplir con una demanda de riego exigida. La finalidad principal de esta tesis es contribuir a la estandarización de los sistemas de control de riego y a la integración de mecanismos de diagnóstico de fallos avanzados. Para ello y partiendo de un caso de estudio de un sistema de control de riego piloto, la memoria se encuentra constituida por las siguientes tres partes:En la primera, se propone un modelo de procesos que pretende estandarizar los sistemas de control de riego y su interoperabilidad con sistemas de gestión. Todo esto bajo las normativas ISA-88 e ISA-95 y la especificación XML del ISA-88: Batch-ML. En este punto la tesis trata la descripción de los modelos físicos, de procedimientos y de procesos de sistemas de control de riego, por medio del lenguaje de marcas extensibles (XML), centrándose principalmente en la programación de órdenes de riego y en la determinación en tiempo real del estado de los dispositivos del sistema.Para validar dicha descripción, en la segunda parte se presenta la implementación de un software prototipo que supervisa y controla, por medio del protocolo industrial OPC, un sistema de control de riego piloto que actualmente pertenece al grupo de investigación CEPIMA (Centre d´Enginyeria de Processos i Medi Ambient) de la UPC, el cual colabora como socio académico del grupo de empresas públicas TRAGSA.Finalmente en la tercera parte, se realiza un estudio del diagnóstico de fallos del sistema - caso de estudio, partiendo de la problemática que este tipo de sistemas conlleva, al sólo poder determinar automáticamente los fallos que se presentan en las válvulas más no en los sensores de caudal existentes en el sistema. Por lo tanto se plantea utilizar una técnica de diagnóstico de fallos a nivel estructural, que permite detectar y aislar los fallos desde el análisis del comportamiento del mismo sistema. Todo esto desde el enfoque FDI.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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ISA-88 modeling and fault diagnosis of irrigation control systems = Modelización ISA-88 y diagnóstico de fallos en sistemas control de riego

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Imagen de apoyo de  Travelling imaginaries: Perceptions and representations of Niagara Falls through media

Travelling imaginaries: Perceptions and representations of Niagara Falls through media

Por: Angélica Yaneth Piedrahita Delgado | Fecha: 01/01/2013

This thesis critically examines travel imagery of Niagara Falls. The intention behind this examination is to inquire about the relationships between perception and the representation of this specific site. These relationships will be introduced considering historical contexts and aesthetic aspects of early travelogues and pictorial representations, such as early paintings and stereoscopic images.Throughout the paper, these depictions will be compared with today’s depictions of Niagara Falls on social media websites that involve publishing photographs and comments that describe the visitor’s experience. By comparing distinct ways of disseminating representations of the site organized in a chronological order, this paper aims at unfolding critical questions about travel representations through time and media.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Travelling imaginaries: Perceptions and representations of Niagara Falls through media

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Imagen de apoyo de  Evaluating the Efficiency of GUI Ripping for Automated Testing of Android Applications = Evaluando la eficiencia de GUI Ripping para automatización de pruebas de aplicaciones para Android

Evaluating the Efficiency of GUI Ripping for Automated Testing of Android Applications = Evaluando la eficiencia de GUI Ripping para automatización de pruebas de aplicaciones para Android

Por: Santiago Carrillo Barbosa | Fecha: 01/01/2014

Mobile devices and theri applications continue increasing at a fast rate. Android is the leading mobile operating system, with more than 1 billion active devices worldwide. In order to improve the quality of Android applications, we must explore and nd cost-e cient solutions to automate part of their testing process.GUI Ripping is a technique that allows a systematic and automated exploration of an application's Graphical User Interface (GUI).During this exploration, test cases are generated and executed. To evaluate GUI Ripping, I conducted an empirical experiment using GUI Ripper and the Monkey. The e ciency of these testing tools was evaluated, comparing the code coverage and the number of faults detected on two Android applications.The experiment results showed the better e ciency of GUI Ripping, achieving higher code coverage and fault detection rate.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Evaluating the Efficiency of GUI Ripping for Automated Testing of Android Applications = Evaluando la eficiencia de GUI Ripping para automatización de pruebas de aplicaciones para Android

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Imagen de apoyo de  Strategic aspects and recommendations for introducing photovoltaic systems in Colombia in bilateral cooperation with Germany (between Colombian and German enterprises)

Strategic aspects and recommendations for introducing photovoltaic systems in Colombia in bilateral cooperation with Germany (between Colombian and German enterprises)

Por: Juan Fernando Higuita Peña | Fecha: 01/01/2013

In this study, the Colombian electricity market, its regulation and its current tariff scheme was examined. Here, the operation of the electricity system and its value chain are described in detail. Future scenarios of supply and demand are also shown. The study presents a description of the legal incentives given by the government for the promotion of renewable energies, and strategic aspects and recommendations for the development of solar photovoltaic (PV) industry in Colombia were identified and formulated. In particular, strategies for collaboration between Colombia and Germany, which is a leader in the PV industry.The report presents an overview of solar PV systems markets worldwide and in Colombia. Regarding the solar market in Colombia, not only the historical development of the PV industry in the country is explained, but also the solar radiation in the whole country is shown. In the same way, this study shows a description of the most common alternatives for the electrification in off-grid areas and an enumeration of drivers and barriers for the development of the PV industry in the country.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Strategic aspects and recommendations for introducing photovoltaic systems in Colombia in bilateral cooperation with Germany (between Colombian and German enterprises)

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Imagen de apoyo de  The use of profile information of UK smartphone users in influencing attitudes towards visiting town centres

The use of profile information of UK smartphone users in influencing attitudes towards visiting town centres

Por: Santiago Zuluaga Sánchez | Fecha: 01/01/2013

Various town centres in the UK have been experiencing worrying symptoms, such as store closures, reduction of footfall, and decrease of retail floor-space. Specifically for the town centres in Greater Manchester, none of the alternatives considered for addressing this problem contemplated the potential of smartphones, personalisation, and social networks. This dissertation is motivated by the current relevance of these topics in different contexts; businesses, social and individual behaviour, retailers, and so forth.The goal of this dissertation is to develop a conceptual model where town centres use technologies and information about individuals to influence their attitude to visit the town centre. Explicitly, the model uses digital footprints in social media and social networks, and data from mobile and static sensors, to build a profile of UK smartphone users. From the information inferred, a personalised message or service can be delivered to the smartphone user which would influence his or her attitude towards visiting the town centre.The model is based on information flowing in both directions benefiting the user as well as the town centre. As sharing, extracting, and using information is an important part of the conceptual model, it is essential that it transmits trust to the users about the privacy of the data, and about the way it is handled. However, the empirical test of the model was not within the scope of this dissertation. Hence, it is proposed to be undertaken as a further research.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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The use of profile information of UK smartphone users in influencing attitudes towards visiting town centres

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Imagen de apoyo de  Proposed methodology for the design and assessment of a biological corridor in the Golfo Dulce Forest Reserve, Costa Rica = Propuesta metodológica en el diseño y evaluación de un corredor biológico en la reserva forestal Golfo Dulce, Costa Rica

Proposed methodology for the design and assessment of a biological corridor in the Golfo Dulce Forest Reserve, Costa Rica = Propuesta metodológica en el diseño y evaluación de un corredor biológico en la reserva forestal Golfo Dulce, Costa Rica

Por: Germán Leonardo Jiménez Romero | Fecha: 01/01/2000

Based on the characteristics of the study area, and those of the fauna studied, corridor designs were proposed using a methodology that considered three main elements: 1) Evaluation of habitat use by wildlife; 2) Use of a Geographical Information System (GIS) to define corridor boundaries (pathways between habitat quality ranks); 3) Management regulations using the corridor as part of the landscape. Herbivores were consistently present in those areas covered by primary forest. Omnivores were located in a wider variety of covers (grass and agriculture, secondary forest, primary forest, melina).Wildcats were located in primary and secondary forest cover types (mainly used by their herbivore prey). The three guilds were maintained far from highways and human settlements but near forest and water resources. Several species crossed the highways that surround the Golfo Dulce Forest Reserve (GDFR). Maps show that available habitat areas of ""excellent"" and ""good"" habitat quality features, were reduced for the species Panthera onca and Puma concolor, and their conflict areas were more extensive; this fact probably pushed these wildcats to move into heavily altered environments.This study reinforced affirmations about the necessity of corridors, based on identification of habitat that meets minimum quality requirements for wildlife (corridor users), and that defines or modifies their spatial distribution. The pathways designed by this procedure coincide with prior studies showing that critical areas for all wildcats species (and for other species related to them) were located north of Corcovado National Park (CNP), San Juan, Mogos, and the area where Piedras Blancas National Park (PBNP) borders the Golfo Dulce Forest Reserve (GDFR). However, the spatial location of corridors is quite different in this proposal and other possible pathway was identified for P. onca and its prey. This pathway was found to be in conflict toward Drake and wetlands of Sierpe Terraba too.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Proposed methodology for the design and assessment of a biological corridor in the Golfo Dulce Forest Reserve, Costa Rica = Propuesta metodológica en el diseño y evaluación de un corredor biológico en la reserva forestal Golfo Dulce, Costa Rica

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Imagen de apoyo de  M&A in the LatAm’s power industry: Drivers and hurdles of successful post-merger integration = Fusiones y adquisiciones en la industria eléctrica Latinoamericana: facilitadores y obstáculos de procesos

M&A in the LatAm’s power industry: Drivers and hurdles of successful post-merger integration = Fusiones y adquisiciones en la industria eléctrica Latinoamericana: facilitadores y obstáculos de procesos

Por: Ana María Mora Luna | Fecha: 01/01/2013

LatAm’s political stability, vigorous growth, and the liberalisation of the electricity markets coupled with the privatisation of their main companies account for the region’s recent protagonism. As a result, deal activity in the LatAm’s power industry increased substantially in the last decade, and understanding of the main challenges faced during the post-merger integration stage of the M&A process became critical for firms using M&A as a tool to accomplish corporate objectives. However, M&A practitioners cannot resort to the literature, as studies pertinent to the LatAm’s power industry are still incipient. In view of the above, the value of this research lies in the insights gained by examining current practice in post-merger integration in the LatAm’s power industry with the aid of semi structure interviews with seasoned M&A executives. Furthermore, by comparing current practice and the literature on the matter, a novel comprehension of the topic in the LatAm’s power industry context is established, and future discussion via cross-pollination of experiences is facilitated and energized. Collectively, the research’s findings provide the following considerations for current and future M&A experts in the LatAm’s power industry, particularly those responsible of leading the post--merger integration process.Taking a conservative stance on synergy assessment, and concentrating the post-merger integration to deliver rather conservative results, and when possible to capitalise on new sources of value creation are determinants of successful deals in the LatAm’s power industry; the highly regulated nature of the business, and the latent risks related to the political and social views about the role of private investors in the provision of public services support this recommendation. Due diligence is not a ‘hygiene factor’ but a determinant of successful post--merger integration; due diligence should be carried out to match up the entire post-merger integration process, identify hurdles and levers to drive the transformation, estimate how long it would take to realise synergies, and understand how the target’s management practices, routines, idiosyncrasy, and beliefs need to be moulded to make the achievement of the deal objectives possible. LatAm’s power companies should rely on the best practices of post-merger integration outlined in the literature in topics such as planning, measurement and monitoring, human resources, and communication in order to enhance the predictability and reassessment of the process, facilitate employees’ buy-in and management of stakeholders’ expectations, and minimise disruption of day-to-day activities.However, as long as the integration is anchored to the deal’s value drivers, flexibility should be allowed to adapt the plan in the meantime. Standard views about leadership, culture, organisation, and speed of integration should be avoided, as these post-merger integration topics are conditional on the deal type, and the extent to which target and acquirer firms’ organisation, processes, and culture need to change after the transaction. Practices related to these topics should be designed and deployed according to an in-depth examination of the integration approach required by the deal. Practitioners should ensure that ‘buy teams’ and ‘integration teams’ are connected; in particular, senior professionals from technical and operational positions should be involved in the planning and design of the post-merger integration to estimate synergies and risks. Furthermore, people in the ‘buy teams’ should be held accountable also for the success of the post-merger integration. There is no cookie-cutter approach to post-merger integration in the LatAm’s power industry; considerably more contingent research, and in-depth case studies are required in order to avoid getting in standard views of post-merger integration.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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M&A in the LatAm’s power industry: Drivers and hurdles of successful post-merger integration = Fusiones y adquisiciones en la industria eléctrica Latinoamericana: facilitadores y obstáculos de procesos

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Imagen de apoyo de  The use of derivatives and the cost of equity: Evidence from UK MNE’s = El uso de derivados y el costo de capital: Evidencia de empresas multinacionales en el Reino Unido

The use of derivatives and the cost of equity: Evidence from UK MNE’s = El uso de derivados y el costo de capital: Evidencia de empresas multinacionales en el Reino Unido

Por: María Ximena Caicedo Montana | Fecha: 01/01/2014

This paper studies the hedging activities of 104 non-financial UK MNEs from 2005 to 2009 to examine their potential effect on the cost of equity. We use the Fama and French Three Factor Model to estimate the cost of equity and we collect detailed information on hedging and risk management activities directly from the annual reports. Although we evidence a negative relation between the cost of equity and hedging activities, we find that the cost of equity is not significantly affected by whether firms are hedgers or non-hedgers.We further use different subsamples and we are able to observe that: (i) size and leverage are important factors in the analysis of hedging and cost of equity, and (ii) the financial crisis plays an active role in the way firms understand and react towards unexpected volatility and risk. Finally we find that controlling for endogeneity of the hedging decision and for potential sample selection bias our results are more robust and are supporting evidence for the negative and significant relationship between hedging and cost of equity.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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The use of derivatives and the cost of equity: Evidence from UK MNE’s = El uso de derivados y el costo de capital: Evidencia de empresas multinacionales en el Reino Unido

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Imagen de apoyo de  Estudio de la prevalencia de la parasitación por Demodex spp en el perro mediante una técnica de PCR en tiempo real

Estudio de la prevalencia de la parasitación por Demodex spp en el perro mediante una técnica de PCR en tiempo real

Por: Wendie Oriana Roldán Villalobos | Fecha: 01/01/2011

El objetivo del presente estudio fue evaluar la prevalencia de la parasitación por Demodex en el perro mediante una técnica de PCR en tiempo real (RT-PCR). Fueron utilizados 100 perros procedentes del Centro de Acogida y Protección Animal del Maresme (Mataró-Barcelona) que no presentaban signos clínicos compatibles con demodicosis y en cuyas historias tampoco constaba que hubieran padecido esta enfermedad. Se recogieron muestras de pelo de cada animal (250-300 pelos) de cinco localizaciones distintas (cabeza, dorso, miembros anteriores y posteriores y abdomen) y se llevó a cabo una técnica de RT-PCR para detectar el DNA de Demodex. Los resultados obtenidos mostraron un 17% de positividad, de los cuales 58,82% eran machos y 41,18% eran hembras. 64,71% animales de pelo largo y 35.29% de pelo corto.La ubicación del ácaro correspondió en su mayoría a abdomen (50%) y cabeza (33,33%), seguida de miembros posteriores (25%) y en igual proporción dorso y miembros anteriores (16,66%). Estos hallazgos confirman en un amplio muestreo de campo, la teoría de que los perros clínicamente sanos pueden albergar Demodex en sus folículos pilosos, y que por ende, las lesiones aparecen cuando la carga parasitaria aumenta significativamente. Se hace necesario continuar con este tipo de estudios para determinar si Demodex está presente sólo en una parte de la población canina (reservorios) que no supera el 20% o si por el contrario permanece en un pequeño número en la mayoría de perros, tal vez en migración constante, por lo que su detección se hace muy difícil.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Estudio de la prevalencia de la parasitación por Demodex spp en el perro mediante una técnica de PCR en tiempo real

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Imagen de apoyo de  Dynamics: Where the digital really moves. A proposal to improve the engagement of primary school children with sport using their ICT skills as a tool

Dynamics: Where the digital really moves. A proposal to improve the engagement of primary school children with sport using their ICT skills as a tool

Por: Paola Marcela Mejía Lizcano | Fecha: 01/01/2015

Children are having a sedentary lifestyle in front of a screen and this is generating problems in their health, their behaviour and their academic performance. The challenge that arises from this situation is How to improve the engagement of primary school children (8-12 years) with sport using their digital (ICT) skills as a tool? Nowadays children do not learn the basic motor skills properly and when they face sporty situations they cannot perform with competence and confidence. This fact makes them feel sport is not fun and as a result they avoid active activities and prefer sedentary ones. Additionally children usually need an adult –parents, teachers or coaches- to encourage them to be active, but if the adults are not skilled and well prepared to motivate them properly, the active experience is not good enough to build physical literacy on them. On the other hand, for doing activities in front of a screen -such as playing games- children explore, discover and learn alone.They spend hours doing the same activity because the fun is the main motivation for learning and mastering skills. This fact defined the concept of Dynamics: What if the motivation to practice physical activity is driven by the same exploration and discovery process the children are having with video-games? After researching what videogames are teaching to players a very important trend was found. Minecraft which is considered a videogame is actually a digital toy that offers a non-dictated play experience and helps children to have a transmedia learning through play. This means that the players have to explore, learn and master ways of playing not only using the game but other resources such as you tube tutorial videos, blogs, wikis and the Minecraft community among others.The proper use of these resources and the application and sharing of the information available makes possible to the players to play better and achieve their goals in the game while developing their digital literacy. If children are able to use different resources in different digital contexts to learn digital literacy while having fun why not include some physical resources to the game experience to make them learn physical literacy at the same time and become confident to perform any sporty activity? Under this principle Dynamics was developed. Dynamics is a game that uses Minecraft™ as a platform to encourage children to be active and develop their physical and digital literacy while exploring, building and using dynamic artefacts. To be able to play, children should collect dynamic blocks by doing physical exercises related to the basic motor skills in blocky spaces generated by them having a real space as a base. The Dynamic Blocks are available to the players according to their age, weight, height and bone-muscle-fat proportion. (This data that is stored and tracked by a multi-movement sensor) When the kid improves the fitness level and the mastery level, the advanced blocks are unlocked. In this way the game personalises the experience for each player. Using a see-through holographic headset Dynamics can be played in any indoor or outdoor place and prepares children to face sporty activities with competence and confidence while having fun being part of their Minecraft creations. Dynamics also allows parents, teachers and coaches teach motor skills to children and track their progress.
Fuente: Biblioteca Virtual Banco de la República Tipo de contenido: Tesis
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Dynamics: Where the digital really moves. A proposal to improve the engagement of primary school children with sport using their ICT skills as a tool

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