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Imagen de apoyo de From dreamt to relegated: Speed in Bogotá and TransMilenio, 1996-2006 = De soñada a relegada: la velocidad en Bogotá y TransMilenio, 1996-2006

From dreamt to relegated: Speed in Bogotá and TransMilenio, 1996-2006 = De soñada a relegada: la velocidad en Bogotá y TransMilenio, 1996-2006

Por: Carlos Felipe Pardo | Fecha: 2009

The dissertation develops an analysis of how speed (as a quotient of space and time) has been described as a positive attribute and an adequate solution to industrial development, cities' efficiency and, in general, citizens' well being, while time?space compression as an underlying process has been widely studied but rarely acknowledged in policy. It analyses the evolution of the discourse on speed from before Bogotá’s BRT system “TransMilenio” (in 1996) and until recently (in 2006) and how it may have influenced such discourse. It questions the usefulness of speed and some transport interventions in Bogotá, and how other more structural measures may be taken to solve a city’s ills. The dissertation provides a conceptual framework on time, cities and time?space compression and speed, followed by a description of Bogotá and TransMilenio and results of the study. It ends with a discussion on the role of speed in Bogotá, the evolution of transport planning, and time?space compression and how it relates to the case in question. 
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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From dreamt to relegated: Speed in Bogotá and TransMilenio, 1996-2006 = De soñada a relegada: la velocidad en Bogotá y TransMilenio, 1996-2006

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Imagen de apoyo de Development and Performance Evaluation of a Frequency-Agile Test Network = Implementación y evaluación de desempeño de una red de pruebas con frecuencias reconfigurables

Development and Performance Evaluation of a Frequency-Agile Test Network = Implementación y evaluación de desempeño de una red de pruebas con frecuencias reconfigurables

Por: Guilberth Martínez Vargas | Fecha: 2009

New generation wireless communication systems should support the increasing demand for efficient utilization of the electromagnetic spectrum. The Cognitive Radio (CR) paradigm is envisioned as a new technique to realize this goal. Nowadays, Software Defined Radios (SDRs) are the foundations on which the CR will be achieved. In this thesis we implemented an SDR network testbed based on a GNU radio platform. The test network was used to evaluate the actual performance of two methods that attempt to contribute as constituents of a Radio Environment Map (REM). REMs are a new approach to provide situation awareness for CRs. The first technique under analysis was a colouring-based frequency allocation mechanism that optimizes the assignment of frequency channels in the 2.4 GHz band. Its effectiveness was demonstrated using several performance tests in different scenarios and conditions. This study also explores the viability of using our SDR testbed to execute real-time power measurements to estimate the dynamics of indoor radio propagation. This is a preliminary step to obtain complete radio environment awareness, and thus contribute towards realizing the REM and CR approaches. 
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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  • Ingeniería

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Development and Performance Evaluation of a Frequency-Agile Test Network = Implementación y evaluación de desempeño de una red de pruebas con frecuencias reconfigurables

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Imagen de apoyo de The Failure of U.S. policies in Latin America: From The War on Drugs to The War on Terror = El fracaso de las políticas de los Estados Unidos en América Latina:de la guerra contra las drogas a la guerra contra el terrorismo

The Failure of U.S. policies in Latin America: From The War on Drugs to The War on Terror = El fracaso de las políticas de los Estados Unidos en América Latina:de la guerra contra las drogas a la guerra contra el terrorismo

Por: Luz Andrea Granados Castillo | Fecha: 2009

Since the 70s when cocaine consumption first took off in the US, this country has been fighting in Latin America the supply-side ‘war on drugs’ which was placed mainly in Colombia since the 90s, the only country in the region that has an additional component to the drugs problem, guerrillas and paramilitaries, both who use the drug trade to fuel a protracted conflict. The US fashioned under Clinton’s administration the controversial anti-drug strategy known as 'Plan Colombia' a policy that made Colombia the 3rd largest recipient of military aid in the world after Israel and Egypt until the Afghanistan and Iraq era; however after 9/11 the strategy took a different course from a war against drugs to a war against terrorism, significantly increasing the military counter-insurgency component of Plan Colombia, deepening the US dependence in the country and isolating it from the rest of Latin America. The results after 40 decades of US investment and intervention are questionable since the policies have proven to be a failure as they have not reached the expected results and have worsened the problems they tried to tackle. In a nutshell, the US anti-narcotics policy in Latin America has been a failure since after 40 decades and billions of dollars invested, it has not helped to curb production, trafficking and demand; but it has undermined the democracy and triggered conflict in countries where drugs are produced; the case of Colombia exemplifies this ‘war system’ where the ‘war on drugs’ shifted to ‘war on terrorism’ under the framework of the US strategy.
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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The Failure of U.S. policies in Latin America: From The War on Drugs to The War on Terror = El fracaso de las políticas de los Estados Unidos en América Latina:de la guerra contra las drogas a la guerra contra el terrorismo

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Imagen de apoyo de Performance Evaluation Of The Clinimacs System For The Positive Selection Of CD34+ Cells From Stem Cell Products Factors Affecting CD34+ Cell Recovery

Performance Evaluation Of The Clinimacs System For The Positive Selection Of CD34+ Cells From Stem Cell Products Factors Affecting CD34+ Cell Recovery

Por: Guillermo Andrés Orjuela Falla | Fecha: 2009

CD34+ cell dose in the transplanted product is still considered a measure of the engraftment potential in haemopoietic stem cell transplantation (HSCT). CD34+ selected products are characterised by their high purity and depleted T-cells. These characteristics have made them traditionally suitable to decrease the incidence of graft versus host disease, particularly in haploidentical HSCT. The CliniMACS is a state of the art cell sorting system based on magnetic particles conjugated to CD34 antibodies. This study retrospectively evaluated the CliniMACS system performance in terms of CD34+ purity and cell recovery, and T-cell depletion in the selected product. The results were compared against target values fixed by the processing centre, as well as against published data. Factors affecting the CD34+ cell recovery were also investigated and a pilot study was carried out to assess the effect of cryopreservation on the viability of the selected products. In total, 151 procedures were analysed. The mean recovery and purity were 64.82 + 16.19 and 88.0 + 11.0% respectively. The mean T-cell depletion was 4.7021 + 0.5129 logs. Only purity was slightly below the specification (90%), with the lowest values obtained from peripheral blood (PB) collections. Factors affecting the recoveries were the overall age of the product (p=0.001), overnight storage (p=0.002), and the use of a particular tubing set with the instrument (p=0.002). The mean CD34+ viability was not significantly different to the value before cryopreservation (p=0.068). Results from this study were comparable with published data of the CliniMACS system performance. Local investigations regarding the purity of PB products should be performed. For the first time, using a magnetic separation method, factors affecting CD34+ recovery were identified. The significance of the effect of product age and overnight storage on cell recovery, provide a rationale for further prospective studies
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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  • Medicina

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Performance Evaluation Of The Clinimacs System For The Positive Selection Of CD34+ Cells From Stem Cell Products Factors Affecting CD34+ Cell Recovery

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Imagen de apoyo de Policy Recommendations To Foster The Development Of The Vegetables Supply Chain In An Agrarian District = Recomendaciones de Políticas para Impulsar el Desarrollo de un Clúster Agrícola en un Distrito Agrario en Antioquia

Policy Recommendations To Foster The Development Of The Vegetables Supply Chain In An Agrarian District = Recomendaciones de Políticas para Impulsar el Desarrollo de un Clúster Agrícola en un Distrito Agrario en Antioquia

Por: Yúber Andrés Romero Aristizábal | Fecha: 2009

Oriente Antioqueño is an important region within Antioquia. There, the production of vegetables represents an important element of the economy, with approximately 12,000 farmers cultivating vegetables in four municipalities. There, farmers have inadequate training in agricultural practices, they lack adequate instruction on how to use fertilizers and pesticides, and also they do not have the appropriate instruments, among many other technological pitfalls. This situation leads to high levels of crops losses, higher costs of production, and sometimes, noncompliance with phytosanitary standards and environmental damage. In order to solve the problem this thesis analysis the outcome from central policies and covers the analysis of two international cases (in Brazil and Nicaragua) looking for new strategies to foster competitiveness in the production of vegetables.I identified four policy options: (1) maintaining the status quo, (2) increasing municipal revenues and restructuring UMATAs, (3) upgrading Law 811, and (4) implementing a cluster development program. The first alternative assesses the implications of letting the market operate under current conditions. Policy alternatives 2 and 3 evaluate the benefits from restructuring agricultural extension offices and the agreements of competitiveness. Finally, implementing a cluster development program explores the gains from creating a local strategy to generate an enabling environment in the production of vegetables. After evaluating the policy options using the criteria of political feasibility, administrative feasibility, effectiveness, efficiency, and equity, I recommend implementing a cluster development program. This option is likely to generate higher benefits as it counteracts problems in the supply and the demand side of the vegetables supply chain. Moreover, as a program implemented at the local level by local institutions, it promises better results.
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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Policy Recommendations To Foster The Development Of The Vegetables Supply Chain In An Agrarian District = Recomendaciones de Políticas para Impulsar el Desarrollo de un Clúster Agrícola en un Distrito Agrario en Antioquia

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Imagen de apoyo de Option-implied volatility and credit announcements: an event study approach = La volatilidad implícita en opciones y anuncios de crédito: estimacion via estudio de eventos

Option-implied volatility and credit announcements: an event study approach = La volatilidad implícita en opciones y anuncios de crédito: estimacion via estudio de eventos

Por: Nicolás Salamanca Acosta | Fecha: 2009

The aim of this paper was to measure the effect of different credit-related events on the option implied volatility of several companies that belong to the Dow Jones Euro Stoxx 50 index list. Measuring the effect of credit events on volatility will augment on the already important body of literature that investigates the volatility-related phenomena; in particular those who research the effect of news on volatility. I find that, over the entire window around the credit events, there was a decrease in the implied volatility but that only the negative events have a statistically significant effect, which reflects the stronger information content of negative credit events researched by previous papers. I also found that this negative effect is mainly due to a strong “reversal” effect in the post-event 10-day period, where the negative effect is stronger and more statistically significant (particularly for the negative events). Furthermore, during the pre-event period there is not much evidence that supports any type of foresight of the market. My results also suggest that there is a difference between the behavior of the implied volatility when the events are outlook changes and credit reviews, and when the event is a rating change (downgrade/upgrade).
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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  • Economía

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Option-implied volatility and credit announcements: an event study approach = La volatilidad implícita en opciones y anuncios de crédito: estimacion via estudio de eventos

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Imagen de apoyo de ‘Under the colombian flag’: nation-building on San Andrés and Providence islands, 1886-1930

‘Under the colombian flag’: nation-building on San Andrés and Providence islands, 1886-1930

Por: Sharika DeShawn Crawford | Fecha: 2009

Under the Colombian Flag examines the Colombian state‘s efforts to incorporate the Afro-Caribbean English-speaking Protestant islanders of San Andrés and Providence into the Spanish-speaking Catholic nation. The project analyzes how those cultural struggles and political negotiations shaped the Colombian nation-building process. I illustrate how Colombian political elites largely spoke of islanders‘ ethnic differences in terms of cultural attributes such as language, religion, and customs. In their minds, these characteristics were malleable. The Colombian nation-builders‘ project thus ignored North American and European pseudo-scientific understandings of race in order to incorporate ethnically and racially diverse populations into their homogenizing agenda, which promoted the Spanish language, Hispanic culture, Roman Catholicism, gendered notions of morality, and racial views of health and modernity. San Andrés and Providence islanders had a different understanding of racial and national identities. They tended to formulate their Colombian identity in terms of loyalty, reciprocity, and rights. My work contributes to the growing body of historical scholarship on race and nation-building in Latin America and the Caribbean as well as scholarship investigating the experiences of black communities in the Atlantic world.
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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‘Under the colombian flag’: nation-building on San Andrés and Providence islands, 1886-1930

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Imagen de apoyo de Coupling level set methods with the ensemble kalman filter for conditioning geological facies models to well and production data

Coupling level set methods with the ensemble kalman filter for conditioning geological facies models to well and production data

Por: David Leonardo Moreno Bedoya | Fecha: 2009

In the work we developed a new methodology based on the ensemble Kalman filter (EnKF) and the level set method for the continuous model updating of geological facies with respect to production and static (well logs) data. We modelled geological facies using a level set representation and further conditioned them to production and static data using the ensemble Kalman filter. The history matching was done in a continuous fashion since the filter does not depend on previous states and updates parameters and states of the physical system as it receives data from the fields. The methodology is completely new and may provide an alternative to the pluri-Gaussian method with competitive complexity times. Further, the methodology allows to involve prior knowledge of the reservoir as a template base case in a Bayesian-like update. The methodology was tested and compare to others and implemented on a real 3D north-sea and synthetic reservoirs.
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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Coupling level set methods with the ensemble kalman filter for conditioning geological facies models to well and production data

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Imagen de apoyo de Brain-machine interface for decoding imaginary limb movements = Interface cerebro computador para la decodificación de movimientos imaginarios

Brain-machine interface for decoding imaginary limb movements = Interface cerebro computador para la decodificación de movimientos imaginarios

Por: Anderson Mora Cortés | Fecha: 2009

In this thesis two different studies are presented separately because each study has a different purpose even though the two studies are complementary. For the first study an available dataset for BCI is used. This dataset is consistent with the aim of the first study because it allows the implementation and development of the proposed technique for BCI based on imaginary limb movement with a small amount of electrodes. The technique I implemented trough this study is a reliable option to be used for a BCI-based on imaginary movements. In the second study a different dataset is used because the requirements for the technique to be implemented are different. Training and testing dataset are necessary to describe a practical computational technique that is applied for a single trial classification based on a Common Spatial Pattern and complemented with a linear discriminator. The training data is used to build a classifier and the testing data allows measuring the performance of the classifier implemented. After testing the classifier the good performance obtained makes this technique of great interest for any imaginary movement based-BCI.
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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Brain-machine interface for decoding imaginary limb movements = Interface cerebro computador para la decodificación de movimientos imaginarios

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Imagen de apoyo de Race and racisms in selected history and social studies textbooks in Colombia and South Africa = Raza y racismos en libros- texto de historia y ciencias sociales en Colombia y Sur Africa

Race and racisms in selected history and social studies textbooks in Colombia and South Africa = Raza y racismos en libros- texto de historia y ciencias sociales en Colombia y Sur Africa

Por: Diana María Rodríguez Gómez | Fecha: 2009

This paper analyses how contemporary Colombian social studies and South African history textbooks represent notions of race and racism to combat the historical legacies of these countries. It uses Critical Discourse Analysis to argue that, while there has been significant progress made in overcoming racism in the new textbooks in the two countries, there are still many challenges. In particular the paper notes that notwithstanding the more equal and balanced representation of traditionally excluded subjects, new forms of exclusion still permeate new social studies and history textbooks in Colombia and South Africa. In reviewing the textbooks produced in the two countries, the paper provides markers for researchers and policy makers seeking to transform deep-seated inequities in society. 
Fuente: Biblioteca Virtual Banco de la República Formatos de contenido: Tesis
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Race and racisms in selected history and social studies textbooks in Colombia and South Africa = Raza y racismos en libros- texto de historia y ciencias sociales en Colombia y Sur Africa

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