The excavation for the 53-story reinforced concrete One Museum Park West building (OMPW) in Chicago was constructed using combined support systems. The building was supported by caissons and a perimeter wall formed by secant piles which transitioned to tangent piles below the bottom of the cut. After installing the perimeter wall and deep foundations for the building, the excavation for the reinforced concrete central core was supported by a circular cofferdam made of sheet piles and steel ring beams. This excavation was made using conventional bottom-up excavation techniques. The excavation for the rest of the building was made using a top-down method and was laterally braced with reinforced concrete floor slabs structurally connected to the secant pile walls and the reinforced concrete core. Field performance data during construction of the OMPW basements were collected with settlement points, inclinometers and strain gages installed in the concrete basement slabs. Significant settlements were observed adjacent to the excavation during wall and deep foundation installation, central core construction and top-down excavation. The influence of concrete material time-dependence of the floor slabs on the performance during top-down excavation is evaluated and a method for the separation of temperature-related strains from the excavation-induced strains in the concrete is described. The construction of the basements is simulated with a 3D numerical structural model to study the influence of the concrete material time-dependence of the floor slabs in the excavation-induced movements resulting from top-down construction. Computed strains in the floor slabs are compared with the observed performance data collected from the strain gages. For use in numerical simulation of the entire excavation process, hypoplasticity constitutive parameters for clays (HC model) at the element test level were calibrated with tests conducted on high quality block samples obtained from the excavation of Block 37 project in Chicago. They included oedometer tests, bender element measurements, and triaxial tests following different stress probes, and were further refined with seismic cone penetration results.  The entire OMPW excavation is simulated with the calibrated parameters with a fully coupled-flow deformation, three-dimensional finite element model. Influence of the construction of secant pile walls, concrete material time-dependence, and nonlinear concrete behavior of the perimeter pile walls on the performance of the OMPW excavation is determined. Conclusions about top-down construction are drawn in light of the measured and simulated performance of the OMPW excavation.

Concessional agreements have been to many developing countries the keystone to reach development. Since the middle twentieth century up to now roads, water - wastewater systems, electricity’s generation and distribution have been operated under arrangements that foster the private sector participation. Concessional agreements seem to be an advantageous feature of project finance for a country as a whole and perhaps that is why governments have mostly opted for this option. The foregoing sum up to developing world problems, as lack of own recourses to build, operate or maintain infrastructure and inexperience of public sector in these affairs, have arisen the utilization of concessional agreements. Developing countries use to follow the models pre-established by developed countries embracing either slightly or substantial changes in the schemes. Concessions have not been the exception. The questions then, rise from two sides. From the developed countries view it is appropriate to inquire: Did concessional agreements contributed to third world countries development? Are they still been utilized? If so, what made them work? What failed? On the other hand we should ask ourselves: Have developing countries followed carefully the third world concessional schemes? Have they settled new schemes? What were developing countries’ purposes when establishing concessional agreement schemes as public policies? Have those schemes worked or not? What is the landscape in a developed country such as Germmany and in a developing country such as Colombia? A concessional agreement as a project finance´s feature depends heavily on its preparation. Structuring phase plays a major role to reach success. Project finance is a matter of risk. Implementation of concessional agreements is as well a matter of risk. Parties assume their own project responsibility and therefore they relay in the project risks allocation. Risks allocation is the first mitigation measure. A proper structuration supposes an accurate allocation of risks and a better performance of each party. This research as of an appraisal between the role of infrastructure concessions in developed and developing countries, and has as a purpose to make a comparison between both schemes regarding the management of infrastructure concessions in their structuring phase paying special attention in the risks allocation and mitigation. The foregoing study would focus in Germany and Colombia´s scenarios principally, but using as reference other cases in specific issues, if necessary.

Making study and diagnosis to implement the OEA project for company Dexson Electric SAS and ensuring that all the conditions and requirements required by the DIAN or Customs authorities, it have been fulfilled in order to ensure efficient, safe and reliable foreign trade operations.

In the last decade, growing recognition has been given to the reparation of the harmful experiences of victims of armed conflicts as a way to transform war torn societies into sustainable peace. In the Colombian case, reparation measures have been introduced within the peace agreements from the mid-2000s onwards. Such initiatives have been oriented towards the reparation of rights, socio-economic improvements and cultural practices of people that have suffered the immediate effects of conflict; namely peasants and inhabitants of rural areas. However, many victimized groups still await reparation and continue to experience the absence of the state in regions, which are formally identified as successful post-conflict scenarios due to the absence of war. Therefore, daily life experiences of those are still being influenced and negatively affected by long-term effects of conflict. Despite the fact that the internal displacement phenomenon has long been addressed by academia, the trajectories and outcomes of unsupported returning processes on victims remain underdeveloped. Thus, this research aims to contribute to these matters by exploring the ways in which the effects of conflict have shaped victims’ livelihoods. Utilizing a mixed methods design, this article combines a variety of interviews and surveys conducted among rural families and key stakeholders. This research reveals how by returning to their territories, people of Pitacapacho found a claim on their agricultural vocation, and a way to avoid being an “urban poor”. However, the transition from self-consumption to wage labor and the change of the agricultural land use to the development of extractive industries are issues that indicate how peasant's ideas and practices towards the territory have been challenged and transformed.

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.

Trajectory planning has recently gained importance in the mobile robot community as a motion planning strategy to solve the problem of guiding the robot from a initial location to a target location in an environment with static or dynamic obstacles. This thesis is concerned with the timed elastic band approach and model predictive control to find the optimal trajectories subject to a differential constraints of a non-holonomic platform. The objective of this thesis is to augment the timed elastic band approach to general kinematics such as the mobile robots with differential drive, the car-like systems and the truck and trailer systems in specific environments. Several cost functions are evaluated to task of obstacle avoidance. For each kinematic, the metrics of traveling time starting from a fixed initial position to a goal location as well as the traversed distance between those states are evaluated. This thesis concludes with a comparative analysis of timed elastic bands with the robot motion planning approach RRT (Rapidly-exploration random tree).

Current policy-making understands human and ecological systems as independent, leading to the misconception that, though they interact, they can be managed separately. This often leads to policy overlooking the effects that the environment has on human structures, and vice versa. Under environmental stress, this disconnection may cause the community to fail, which can manifest in migration and conflict. In a climate-change scenario, it becomes increasingly important to consider social and environmental structures as one single system, that must be managed as a unit. Also, increasing the resilience of socio-ecological systems becomes a priority to prevent climatic disruptions to cause the system to collapse. This dissertation aims to learn from using systems thinking to interpret the Syrian crisis, following the 2006-2011 drought, and extract insights from using the same methodology in different contexts. This is done through the construction of two diagrams that help visualize socio-ecological system in a more accessible way, offering policy-makers an instrument to understand and manage socio-ecological systems more effectively. Finally, it discusses how these lessons can be helpful for the post-conflict process in Colombia, which shares many structural flaws with pre-conflict Syria, and explores how the methodology can be useful to identify and address these flaws for sustainable peace-building.

En este capítulo se presentan los resultados de un modelo bayesiano para la merluza del Atlántico norte, una especie que es poco vulnerable a cambios medio ambientales pero cuya biología todavía no es completamente conocida, ya que el crecimiento de la especie aún no se ha determinado con exactitud. Los resultados presentados comparan escenarios donde se utiliza información de diversos stocks de merluza para estimar parámetros biológicos como la mortalidad natural, la tasa de crecimiento y el reclutamiento máximo, con otros donde estos parámetros se asumen constantes. Texto tomado de la “Introducción general” de esta tesis.

This thesis explores how informal property rights are defined and enforced in the business of onstreet parking in Bogota. It establishes that informal businesses could not operate without such property rights and that the value of force has been underestimated in the scant literature devoted to the subject. To contribute to the construction of a currently non-existent informal property rights theory this thesis contrasts the research findings with traditional property rights theory and attempts to redefine classic property rights concepts to fit the context of the urban informal economy. Finally, the thesis explains how mafias can enforce informal property rights, the logic of their actions, and the dangers of their proliferation.

This paper will present two cases that deal with the constitutionality of assisted suicide, Washington v. Glucksberg 521 U.S. 702 (1997) of the Supreme Court of the United States and the judgment C – 239/1997 of the Constitutional Court of Colombia. The main purpose is to examine the understanding that each court presents about the rights to liberty and life, how they balance them and the arguments that each one wield to arrive to different decisions. Also, the paper underlines what considers inconsistences in both judgments. To achieve that goal, the paper will present a brief description of the reasoning and holding of each judgment, then, it will discuss the rights at stake, the balancing done by the courts, the need of regulation on the issue, the role of the legislature on this regard, and physicians´ dilemmas. Lastly, it will provide some conclusions. Este documento presentará dos sentencias ques estudian la constitucionalidad del suicidio asistido, Washington v. Glucksberg 521 U.S. 702 (1997) de la Corte Suprema de los Estados Unidos y la sentencia C - 239/1997 de la Corte Constitucional de Colombia. El objetivo principal es examinar el análisis que cada tribunal presenta sobre los derechos a la libertad y la vida, cómo los pondera y los argumentos que cada uno maneja para llegar a decisiones diferentes. Además, el artículo subraya qué considera incoherente en cada decisión. Para lograr ese objetivo, el documento presentará una breve descripción del razonamiento y los argumentos de cada sentencia, luego, discutirá los derechos en tensión, la ponderación hecha por los tribunales, la necesidad de regulación sobre el tema, el papel del legislador en este sentido, y los dilemas de los médicos. Por último, proporcionará algunas conclusiones.