The Risk-Taking Channel and Monetary Transmission Mechanism in Colombia

The recent financial crisis has brought to the forefront the need of a better understanding of the transmission mechanisms of monetary policy. The main step forward in this direction has drawn on work aimed at stressing the role of the financial sector in this transmission. Particular emphasis has been place on how policy actions impact risk perceptions and attitudes of banks and other financial institutions, leading to shifts in the supply of credit. Along these lines, and based on evidence from Colombia, the present paper finds a significant link between low interest rates and banks’ risk taking based on evidence from Colombia. Lower interest rates raise the probability of default on new loans but reduce that on outstanding loans. Furthermore, this channel of policy transmission depends on some bank, loan and borrower characteristics, as well on macroeconomic conditions such as the rate of growth of the economy.Monetary policy, lending standards, risk taking, duration analysis, accelerated failure time models. Classification JEL: E44, G21, L14

Performance evaluation of a medium access control protocol for a distributed ARQ scheme in cooperative wireless networks

A performance evaluation of a medium access control protocol for a distributed ARQ scheme in cooperative wireless networks is presented in this paper. The protocol under evaluation is the Persistent Relay Carrier Sensing Multiple Access protocol (PRCSMA). The protocol was designed to be easily integrated in standard IEEE 802.11 networks in order to increase their performance and to extend coverage. The main goals of this paper are to present and to discuss the performance evaluation of the PRCSMA under different network configurations. Computer simulations demonstrate the robustness of the protocol under different scenarios.Peer ReviewedPostprint (author’s final draft

Prototipo de la fabricación de una bóveda con hormigón autocompactante con fibras poliméricas. Lecciones aprendidas

La realización de obras en las que se emplean materiales no tradicionales lleva asociada una complejidad estructural y constructiva. Con la comprobación in situ mediante la realización de un prototipo, se podrá poner a punto los equipos materiales y personales, los procedimientos de definición y ejecución, modelos de cálculos utilizados, etc. Con este objetivo se realizó un prototipo de una bóveda representativa a escala real que permitiera: seleccionar la dosificación de hormigón, entre las estudiadas previamente; optimizar el proceso de colocación, ajustando la localización de los puntos de hormigonado; y comprobar la adecuación de los equipos de hormigonado. Con las lecciones aprendidas de la fabricación de este prototipo se plantearon las modificaciones que se deben incorporar en obra. La experiencia adquirida llevó a modificar las fases de hormigonado y permitió adaptar los materiales al elemento construido

Spanish albacore (Thunnus alalunga) surface fishery in the Northeastern Atlantic, summary description in 2018.

Main features of the Spanish albacore (Thunnus alalunga) surface fishery in 2018 were summarized. Fishing activity took place during summer from June to August operating in offshore waters of the northeast Atlantic and in the Bay of Biscay. Albacore was targeted by troll fleet from June to August, mostly in off shore waters of northeast Atlantic and the baitboat in the Bay of Biscay. In 2018, the catch of the baitboat fleet increased 38% while troll fleet increased 15% compared to catch in year 2017. Size composition of catches taken by baitboats and troll fleets in 2018, showed a high proportion of age 2 group, followed by equivalent proportion of age 1 and age 3 groups albacore. Monthly spatial distribution of nominal catch rates were presented for both fleets

EL PROYECTO EÓLICO DE GENERACIÓN DE ENERGÍA ELÉCTRICA DENTRO DEL ÁREA PROTEGIDA DE FORTUNA: un caso de energía limpia con serios problemas ambientales.

The "Compañía Eléctrica Panameña S. A." interprise, iponsered by Unión FENOSA, is developing plans to contruct a plant to generate electric energy using the wind force on the protected area of Fortuna, province of Chiriquí. This initiative presages severe environmental lmpacts related to Complejo Hidroeléctrico Fortuna and its Protector Forest. From this polnt of view, we need to evaluate and analize the problems incited by this new project, and then we must assume the best position for the country benefit. This work intend to advance sorne reflections for discussion about this situation.Hacemos un análisis de los problemas ambientales del proyecto de generación de 30 MW promovido por la empresa "Compañía Eléctrica Panameña S.A.", con el patrocinio de Unión FENOSA que consiste en la Construcción de una Planta de Generación Eléctrica Eólica dentro del Área Protegida de Fortuna, en la provincia de Chiriquí. Se presagian impactos ambientales severos que afectarán el Complejo Hidroeléctrico Fortuna y su Bosque Protector. Adelantamos algunas reflexiones que permitan analizar y evaluar los problemas que surgen de este nuevo proyecto que permita asumir la posición más indicada para el beneficio del paí

Discrete element modelling and simulation of sand mould manufacture for the lost foam process

This paper presents a numerical model of mould manufacture for the lost foam casting process. The process of mould filling with sand and sand compaction by vibration are modelled using spherical (in 3D) or cylindrical (in 2D) discrete elements. The motion of discrete elements is described by means of equations of rigid body dynamics. Rigid particles interact among one another with contact forces, both in normal and tangential directions. Numerical simulation predicts defects of the mould due to insufficient sand compaction around the pattern. Combining the discrete element model of sand with the finite element model of the pattern allows us to detect possible distortion of the pattern during mould filling and compaction. Results of numerical simulation are validated by comparison with experimental data

Dynamics of fluctuations in a fluid below the onset of Rayleigh-B\'enard convection

We present experimental data and their theoretical interpretation for the decay rates of temperature fluctuations in a thin layer of a fluid heated from below and confined between parallel horizontal plates. The measurements were made with the mean temperature of the layer corresponding to the critical isochore of sulfur hexafluoride above but near the critical point where fluctuations are exceptionally strong. They cover a wide range of temperature gradients below the onset of Rayleigh-B\'enard convection, and span wave numbers on both sides of the critical value for this onset. The decay rates were determined from experimental shadowgraph images of the fluctuations at several camera exposure times. We present a theoretical expression for an exposure-time-dependent structure factor which is needed for the data analysis. As the onset of convection is approached, the data reveal the critical slowing-down associated with the bifurcation. Theoretical predictions for the decay rates as a function of the wave number and temperature gradient are presented and compared with the experimental data. Quantitative agreement is obtained if allowance is made for some uncertainty in the small spacing between the plates, and when an empirical estimate is employed for the influence of symmetric deviations from the Oberbeck-Boussinesq approximation which are to be expected in a fluid with its density at the mean temperature located on the critical isochore.Comment: 13 pages, 10 figures, 52 reference