This thesis proposes a novel window aggregate sharing approach for out-of-order stream processing. We combined together the best of two worlds: the Google dataflow model for out-of-order stream processing and the Cutty aggregate sharing strategy. To our knowledge, our solution is the only aggregate sharing strategy for out-of-order stream processing that supports sliding, tumbling and session windows. Based on the experiments with the real world dataset DEBS12 [28] and a 3% out-of-order level, our solution has 1.24 higher throughput than the current implementation in Flink. Moreover, we show that the throughput of our solution becomes higher, as the out-of-order level increases.

Colombia, as many low and middle-income countries, has been deeply influenced by the predominant linear economic model by using their extensive natural resources to create, to some extent, wealth. However, the current environmental problems and global economy deceleration are challenging the country to find new ways to growth the economy without harming the environment. The circular economy (CE) seems to be a promising model to achieve this goal by reducing the dependency on non-renewables, improving the competitiveness through innovation and ¬generating new and rewarding jobs. Thus, this paper explored the enablers that would facilitate the transition towards a CE in Colombia given its specific circumstances such as development gaps in infrastructure and a large informal sector involved in recycling. As a result, an enabling framework was proposed based on secondary data and the insights from interviewing an expert on the field. This framework was the baseline to assess the CE in Colombia and to identify the main interventions that are required to support a transition towards a more sustainable economy. This assessment was carried out through secondary data and some interviews with professionals performing in sustainable development in the country. The evaluation showed that Colombia does not have at the moment the right enabling conditions for a CE deployment. Therefore, the country presents opportunities to reinforce a CE transition in terms of political coherence and a suitable fiscal framework that promotes sustainable practices as well as a robust IT infrastructure and ICTs appropriation among the enterprises to develop business models framed within the CE principles. Moreover, it is required a safe and profitable recovery of materials discouraging the current practices of recycling. Finally, it is important to promote financing schemes and the development of design-led approaches to production among the industrial sector to foster innovation as a key building block of a CE. The findings of this dissertation provide a starting point for future research about the enablers for a CE transition in the context of low and middle-income economies.

El método “El Avión de Papel” es para los niños de Colombia y está destinado a iniciar el camino de aprendizaje o la adquisición de la lengua francesa, para principiantes, niños o los niños con discapacidad mental que se proporcionan a través de la variedad de actividades y la simplicidad de contenido para los niños.Los contenidos proporcionan una comprensión más suave y progresiva de las materias básicas para el aprendizaje de la lengua francesa. Este método proporciona objetivos de aprendizaje, con actividades motivadoras y atractivas (canciones, juegos y proyectos de arte) que desarrollan las habilidades de producción y comprensión oral, iniciando con la introducción a la escritura.El método “El Avión de Papel” tiene como objetivo facilitar el aprendizaje del francés a los niños colombianos, de manera sencilla como un avión de papel, que es fácil de construir y utilizar a cualquier persona, en cualquier lugar.

The Colombian government introduced a capacity market to promote the diversification in the energy matrix, and protect users from high prices derived from dry seasonal events. Unfortunately, the flaws in the scarcity price definition- a mechanism that activates the capacity market obligation and sets a cap price for the spot market- have resulted in a market failure. Specifically, some generation plants have been forced to be unavailable because their variable costs are significantly higher than the scarcity price. This research presents an analysis and some possible alternatives fo the definition of the scarcity price in the Colombian Electricity market. An excel-based model was developed in order to analyse and compare different scarcity price definitions under three dimensions: i) Water management resources. ii) Penalty exposure of agents. iii) Change in prices for final demand. Results suggest that the proposed change in the scarcity price definition would induce to more efficient water management resources, and a reduction in the penalty exposure of agents. Complementary actions are recommended for policy makers in order to avoid some possible side effects of the implementation of a new scarcity price definition.

This thesis introduces a financial simulation model covering two related financial domains: Mobile Payments and Retail Stores systems. The problem we address in these domains is different types of fraud. We limit ourselves to isolated cases of relatively straightforward fraud. However, in this thesis the ultimate aim is to introduce our approach towards the use of computer simulation for fraud detection and its applications in financial domains. Fraud is an important problem that impact the whole economy. Currently, there is a lack of public research into the detection of fraud. One important reason is the lack of transaction data which is often sensitive. To address this problem we present a mobile money Payment Simulator (PaySim) and Retail Store Simulator (RetSim), which allow us to generate synthetic transactional data that contains both: normal customer behaviour and fraudulent behaviour. These simulations are Multi Agent-Based Simulations (MABS) and were calibrated using real data from financial transactions. We developed agents that represent the clients and merchants in PaySim and customers and salesmen in RetSim. The normal behaviour was based on behaviour observed in data from the field, and is codified in the agents as rules of transactions and interaction between clients and merchants, or customers and salesmen. Some of these agents were intentionally designed to act fraudulently, based on observed patterns of real fraud. We introduced known signatures of fraud in our model and simulations to test and evaluate our fraud detection methods. The resulting behaviour of the agents generate a synthetic log of all transactions as a result of the simulation. This synthetic data can be used to further advance fraud detection research, without leaking sensitive information about the underlying data or breaking any non-disclose agreements. Using statistics and social network analysis (SNA) on real data we calibrated the relations between our agents and generate realistic synthetic data sets that were verified against the domain and validated statistically against the original source. We then used the simulation tools to model common fraud scenarios to ascertain exactly how effective are fraud techniques such as the simplest form of statistical threshold detection, which is perhaps the most common in use. The preliminary results show that threshold detection is effective enough at keeping fraud losses at a set level. This means that there seems to be little economic room for improved fraud detection techniques. We also implemented other applications for the simulator tools such as the set up of a triage model and the measure of cost of fraud. This showed to be an important help for managers that aim to prioritise the fraud detection and want to know how much they should invest in fraud to keep the loses below a desired limit according to different experimented and expected scenarios of fraud.

Abstract: This contribution provides for a main comparison between the new Article X proposed by the OECD under Action 6 Final Draft and the new Article 22 of the 2016 US Model Income Tax Convention. For purposes of the above, this contribution is divided in two main parts. The first part contains a comparative analysis of the main differences resulting from a tax treaty policy perspective. The second part compares both proposals under an itemized approach. This second part addresses the specific wording differences between new Article X proposed by the OECD under Action 6 Final Draft and the new Article 22 of the US Model Income Tax Convention. At the time of drafting, some additional changes to the final version of the Article X proposed by the OECD under Action 6 could be made as consequence of the disclosure of the latest version of the US LOB on 17 February 2016. Resumen: Este artículo hace una comparaciòn entre el artìculo X propuesto por la OCDE bajo la acción 6 del reporte final contra la erosión de la base gravable y la transferencia de utilidades, y el nuevo artículo 22 del Modelo de Convenio del Impuesto sobre la Renta de los estados Unidos (modelo 2016). Para efectos delo anterior, el artículo está dividido en dos partes principales. La primera parte establece un análisis de las principales diferencias en materia de política tributaria en relación con la suscripción de tratados. La segunda parte analiza las diferencias específicas en la redacción de ambos artículos.

The Legal Transplant Theory proposed by A. Watson, K. Pistor and D. Berkowitz is defined as movement of a rule or a system of law from one country to another. Under this theory, the mentioned authors conclude that a legal change does not perform in an equal manner in the transplanting country as in the origin country. They argue that the adoption of it in the latter is the result of a comprehensive study of the socio-economic circumstances of the nation, while transplanting countries import the legal entity without having similar circumstances. Furthermore, under this theory, the successfulness of a legal transplant is determined by an adaptation process that the legislator, the governmental institutions and the society of the transplanting country shall undertake to prepare the scenario for the introduction. In consequence, transplanted legal changes are called to fail due to uninformed or erroneous decision made by the law-makers. Pistor and Berkowitz analyzed company regulation in various countries, among them Colombia, to support their theories. Regarding the Colombian case, they referred to the Codes of Commerce of 1853 and 1887, concluding that they were unsuccessful legal transplants from Spain and Chile, respectively.  This paper analyzes the abovementioned theory pretending to determine if the legal transplant theory was correctly applied to the Colombian case. Particular attention deserves the Sociedad por Acciones Simplificadas (S.A.S), which is a new hybrid business form adopted in Colombia as a transplant from the United States’ Limited Liability Company. In the light of this case, the document will determine whether this is called to be an unsuccessful legal transplant (as predicted by the Legal Transplant Theory). If the answer is negative, the document will determine if the S.A.S. is merely an exception of the theory or if it demonstrates the failure of such assumption.

In this paper the subject of documentary in digital times is studied in three chapters that aim to explore these main different angles: 1. The angle of documentary production, with the revision of some study cases; 2. The angle of the main supporting and funding agencies – European centred- that allow creators to fund their projects and; 3. The angle of the exhibition and distribution system, that´s been transformed today by the multiple online distribution platforms. The first chapter develops an overview of the film industry and the documentary box office in the UK and then takes a look on the access to audio-visual technology and the way this influences professional creators and amateurs today. The attempt is to link the ease of use of technology with contents that make the documentaries meaningful in current times, by using some examples that relate documentary to activism, art, politics and education. The second chapter focuses on the revision of three main funding sources –MEDIA at the European level and the British Film Institute and BRITDOC at the British level- which influence the dynamics of documentary filmmaking today enabling resources to be delivered under specific frameworks and supporting the development of connections with stakeholders that become partners and allies of the documentaries with common grounds of work, particular contexts and themes. The third chapter takes a closer look on the exhibition and distribution business structure and platforms to find a universe of possibilities where the future of audio-visual narratives still to be defined, but where certainly documentary has found a way to reach audiences and stand as a powerful medium of transformation.

Customer life time value (CLV) and delinquency behavior are two of the most important firm key performance indicators at the banking industry, and at any other business scenario in which customers are granted credits or loans. Coordination in decisions regarding these two important variables is essential to achieve overall firm performance. We develop a dynamic method that allows simultaneous coordination between CLV and credit risk management decisions while taking into account their time varying behavior, the observed and unobserved customer heterogeneity, and the panel data structure inherent to the CLV-credit risk context. The method, which is a combination of the extended Kalman filter for exponential family of distributions and a fixed effects model has not been illustrated and/or implemented before. Therefore, we show its validity form a theoretical and computational point of view, and how its results can be interpreted to make the desired decision coordination task using synthetic data.

This dissertation explores the analytical status of “hybrid” material transformations that flourish in the indigenous communities of Vichada, Colombia, in relation to the concept of culture. It suggests that these indigenous people live in a culturally intermittent reality as a result of the appropriation of the concept of cultura imposed from the outside world. However, their approach to materiality as becoming rather than being reveals a strategy of creation and recreation of value and identity through the production of meaningful connections in a changing environment, achieved through action, and more specifically by means of the act of making.