La Sostenibilidad de Deuda frente a Riesgo de Catastrofes Naturales

Los desastres naturales son una importante fuente de vulnerabilidad en la región del Caribe. A pesar de ser una de las regiones del mundo con más altas probabilidades de desastres naturales, el Caribe tiene los niveles más bajos de cobertura de seguro. Este articulo examina la vulnerabilidad de las finanzas publicas de Belice debido a la alta ocurrencia de huracanes. El artículo estudia el potencial de instrumentos de aseguración que podrían reducir la vulnerabilidad a estos desastres naturales. Este estudio encuentra que el seguro de Riesgos Catastróficos mejora la sostenibilidad de la deuda del gobierno de Belice. La metodología aplicada por el estudio hace posible estimar el nivel apropiado de cobertura de seguro apropiado. Para el caso de Belice, es como máximo, US$120 millones por año. Organizaciones internacionales pueden jugar un papel importante en asistir a los países a sobrellevar las distorsiones de los mercados de seguros, como también en ayudar a disminuir la resistencia política interna contra la aplicación de esta póliza.

Debt Sustainability Under Catastrophic Risk: The Case for Government Budget Insurance

Natural disasters are an important source of vulnerability in the Caribbean region. Despite being one of the more disaster-prone areas of the world, it has the lowest levels of insurance coverage. This paper examines the vulnerability of Belize’s public finance to the occurrence of hurricanes and the potential impact of insurance instruments in reducing that vulnerability. The paper finds that catastrophic risk insurance significantly improves Belize’s debt sustainability. In addition, the methodology employed makes it possible to estimate the appropriate level of insurance, which for the case of Belize is a maximum coverage of US$120 million per year. International organizations can play a role in assisting countries to overcome distortions in insurance markets, as well as in helping to relax internal political resistance to the purchase of insurance policies.

Carnívoros invasores en Patagonia: Definiendo prioridades para su manejo usando el visón americano (Neovison vison) como caso de estudio

El visón Americano es una especie introducida con una amplia distribución en Patagonia y por su comportamiento de forrajeo es el carnívoro invasor con el mayor potencial para afectar a la biodiversidad en la región. La información disponible acerca de la presencia/ ausencia del visón en la región y de estimaciones poblacionales es muy escasa aun cuando esto es vital para la planificación de acciones de manejo. En este trabajo integramos la información disponible acerca de la presencia del visón hasta la fecha y evaluamos su presencia en sitios donde hay vacíos de información, basándonos en la ubicación de los puntos de liberación de individuos, distribución confirmada y estimaciones de la capacidad de dispersión. Proponemos una Herramienta de Priorización de Áreas (HPA) para definir sitios prioritarios para el manejo, superponiendo mapas de distribución de la especie, de hábitat adecuado y de áreas de importancia para la conservación de la biodiversidad. Entre las áreas prioritarias, seleccionamos tres y sugerimos un Protocolo de Tareas de Erradicación (PTE) como estrategia de manejo del visón americano, basado en experiencias de erradicación Europeas exitosas. Finalmente, estimamos costos relativos asociados a la implementación de tal PTE en cada una de las áreas seleccionadas. Presentamos este trabajo como una herramienta aplicada, enfocada en mostrar una forma simplificada para afrontar el problema de las especies invasoras en Patagonia y su manejo.The American mink is a widespread invasive carnivore in Patagonia, and due to its foraging behavior that allows it to exploit a wide variety of prey, it is the exotic carnivore with the highest potential impact on the region's biodiversity. Available regional information on mink presence/absence, as well as abundance estimations, is scarce even though it is vital to plan management actions. Here, we integrate the confirmed distribution of mink in Patagonia with its potential presence for areas where information is lacking, based on the location of animal releases and estimated dispersal rates. We propose an Area Prioritization Tool (APT) for invasive species management by overlapping habitat suitability, current known range, colonization fronts and areas deemed important for biodiversity conservation. Among the prioritized areas, we selected three and suggested a Protocol for Eradication Tasks (PET), based on successful mink eradication experiences in Europe. Finally, we estimated the relative costs associated with the PET's implementation in each area. We present this work as a systematic, applied tool to show a feasible way to face the invasive species problems in Patagonia and their management.Fil: Fasola, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Valenzuela, Alejandro Eduardo Jorge. Administración de Parques Nacionales. Delegación Regional Patagonia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The Determinants of Corporate Risk in Emerging Markets: An Option-Adjusted Spread Analysis

This study explores the determinants of corporate bond spreads in emerging market economies. Using a largely unexploited dataset, the paper finds that corporate bond spreads are determined by firm-specific variables, bond characteristics, macroeconomic conditions, sovereign risk, and global factors. A variance decomposition analysis shows that firm-level characteristics account for the larger share of the variance. In addition, the paper finds two asymmetries. The first is in line the sovereign ceiling “lite” hypothesis which states that the transfer of risk from the sovereign to the private sector is less than 1 to 1. The second is consistent with the popular notion that panics are common in emerging markets where investors are less informed and more prone to herding.

Model Predictive Control for Spacecraft Rendezvous in Elliptical Orbits with On/Off Thrusters

IFAC Workshop on Advanced Control and Navigation for Autonomous Aerospace Vehicles. 08/06/2015. SevillaIn previous works, the authors have developed a trajectory planning algorithm for spacecraft rendezvous which computed optimal Pulse-Width Modulated (PWM) control signals, for circular and eccentric Keplerian orbits. The algorithm is initialized by solving the impulsive problem first and then, using explicit linearization and linear programming, the solution is refined until a (possibly local) optimal value is reached. However, trajectory planning cannot take into account orbital perturbations, disturbances or model errors. To overcome these issues, in this paper we develop a Model Predictive Control (MPC) algorithm based on the open-loop PWM planner and test it for elliptical target orbits with arbitrary eccentricity (using the linear time-varying Tschauner-Hempel model). The MPC is initialized by first solving the open-loop problem with the PWM trajectory planning algorithm. After that, at each time step, our MPC saves time recomputing the trajectory by applying the iterative linearization scheme of the trajectory planning algorithm to the solution obtained in the previous time step. The efficacy of the method is shown in a simulation study where it is compared to MPC computed used an impulsive-only approach

Trajectory Planning for Spacecraft Rendezvous in Elliptical Orbits with On / Off Thrusters

The 19th World Congress of the International Federation of Automatic Control 2014 Cape Town, SudáfricaIn a previous work, the authors developed a trajectory planning algorithm for spacecraft rendezvous which computed optimal Pulse-Width Modulated (PWM) control signals, assuming that the target was moving in a circular Keplerian orbit. In this paper we extend the algorithm to the case of an elliptical target orbit with arbitrary eccentricity. Since the orbit is elliptical, the linear time-varying Tschauner-Hempel model is used, whose exact solution is possible by using true (or eccentric) anomaly instead of time (which is directly related to both via Kepler's equation). Unlike in the circular case, computing the PWM solution itself requires numerical integration. However, explicit linearization around the computed solution turns out to be possible and is exploited for rapidly improving the solution using linear programming (LP) techniques. The algorithm is initialized by solving the impulsive problem first; the impulses are converted to PWM signals, which are used as an initial guess. Using the explicit linearization and LP, the solution is refined until a (possibly local) optimal value is reached. The efficacy of the method is shown in a simulation study where it is compared to the impulsive-only approach

Trajectory Planning for Spacecraft Rendezvous with On / Off Thrusters

18th World CongressThe International Federation of Automatic ControlMilano (Italy) August 28 - September 2The objective of this work is to present a trajectory planning algorithm for spacecraft rendezvous that is able to incorporate Pulse-Width Modulated (PWM) control signals. The algorithm is based on linearization around a previously computed solution. To initialize the algorithm, a first solution needs to be obtained. To do so, the trajectory planning problem is solved using Pulse-Amplitude Modulated (PAM) control signals; these are then converted to PWM signals, which are used as an initial guess. Iterating, the solution is refined until an optimal value is reached. Simulations show that this method converges after a few iterations. The algorithm is simple and fast, hence it could be implemented online or used together with a Model Predictive Controller

Robust Model Predictive Control for Spacecraft Rendezvous with Online Prediction of Disturbance Bounds

IFAC Workshop Aerospace Guidance, Navigation and Flight Control Systems (AGNFCS' 09) Samara, RUSSIA June 30 - July 2, 2009A Model Predictive Controller is introduced to solve the problem of rendezvous of spacecraft, using the HCW model and including additive disturbances and line-of-sight constraints. It is shown that a standard MPC is not able to cope with disturbances. Then a robust Model Predictive Control that introduces the concepts of robust satisfaction of constraints is proposed. The formulation also includes a predictor of the disturbance properties which are needed in the robust algorithm. In simulations it is shown that the robust MPC scheme is able to handle not only additive disturbances (which are the ones used in the formulation) but also large multiplicative disturbances and unmodelled dynamics (due to eccentricity of the orbit of the target spacecraft)

Pulse-width predictive control for LTV systems with application to spacecraft rendezvous

This work presents a Model Predictive Controller (MPC) that is able to handle Linear Time-Varying (LTV) plants with Pulse-Width Modulated (PWM) control. The MPC is based on a planner that employs a Pulse-Amplitude Modulated (PAM) or impulsive approximation as a hot-start and then uses explicit linearization around successive PWM solutions for rapidly improving the solution by means of quadratic programming. As an example, the problem of rendezvous of spacecraft for eccentric target orbits is considered. The problem is modeled by the LTV Tschauner–Hempel equations, whose state transition matrix is explicit; this is exploited by the algorithm for rapid convergence. The efficacy of the method is shown in a simulation study.Ministerio de Economía y Competitividad DPI2008–05818Ministerio de Economía y Competitividad MTM2015-65608-

Feedback linearization control for a distributed solar collector field

This article describes the application of a feedback linearization technique for control of a distributed solar collector field using the energy from solar radiation to heat a fluid. The control target is to track an outlet temperature reference by manipulating the fluid flow rate through the solar field, while attenuating the effect of disturbances (mainly radiation and inlet temperature). The proposed control scheme is very easy to implement, as it uses a numerical approximation of the transport delay and a modification of the classical control scheme to improve startup in such a way that results compared with other control structures under similar conditions are improved while preserving short commissioning times. Experiments in the real plant are also described, demonstrating how operation can be started up efficiently.Ministerio de Ciencia y Tecnología DPI2004-07444-C04-04Ministerio de Ciencia y Tecnología DPI2005-0286