COORDINACIÓN Y BÚSQUEDA DE NORMAS: UN ENFOQUE DESDE LA TEORÍA DE LA ELECCIÓN PÚBLICA

The present paper analyzes competitive coordination games from a public choice approach. In these, agents may engage in a rent-seeking competition for norms, which redefines property rights and has redistributive effects. For a binary population, the work shows that rent dissipation will depend on the asymmetry of the payoffs, the returns of the rent-seeking activities and on the population distribution. The main conclusion is that, under plausible conditions, the rent dissipation will not be perfect. Classification-JEL : D72rent-seeking, coordination games, welfare losses, collective action.

Carbon footprint of transhumant sheep farms: accounting for natural baseline emissions in Mediterranean systems

Purpose: Transhumance has rarely been analyzed through LCA approaches, and there is little evidence about its emissions level when conducted under different practices (by truck or on foot) or compared to sedentary livestock systems. Moreover, mobile pastoralism is strongly linked to natural resources by its seasonal grazing patterns, thereby occupying the niche of wild herbivores. Considering natural emission baselines in these ecosystems could have relevant effects when estimating their carbon footprint. Materials and methods: Inventory data of 20 sheep farms was collected to estimate the carbon footprint (CF) of lamb meat produced. Farms were divided into three sub-groups representing typical management practices in the region: (1) sedentary (SED), (2) transhumance by truck (THT), and (3) transhumance on foot (THF). Livestock GHG emissions were modeled according to herd structure and IPCC guidelines. Off-farm emissions from external feeds and fuels were accounted based on existent LCA databases. A natural baseline of wild herbivores was established from the population of red deer reported in a hunting preserve, previously considered to be a reference for the natural carrying capacity in Mediterranean ecosystems. GHG emissions of wild herbivores were estimated through two methods based on (1) IPCC guidelines and (2) allometric regression equations. Results and discussion: Carbon footprint ranged from 16.5 up to 26.9 kgCO2-eq/kg of lamb liveweight (LW). Significant differences were identified among sedentary and transhumant farms, the latter consistently showing lower CF values (SED: 25.1 kg CO2-eq/kg LW, THT: 18.3 kg CO2-eq/kg LW, THF: 18.2 kg CO2-eq/kg LW). Sedentary farms resulted in higher GHG emissions (+ 27%) and higher CO2 and N2O, contributions derived from the consumption of additional feeds. Both methods applied to compute emissions for wild herbivores led to similar results (25.3–26.8 Mg CO2-eq/km2), comparatively lower than estimation for transhumant sheep (47.7 Mg CO2-eq/km2). When considering natural baseline emissions, the CF of transhumant lamb meat is reduced by almost 30%, reaching values quite below those reported for intensive lamb production systems in Spain. Conclusions: From our results, mobility of grazing livestock can be considered as a strategy promoting climate change mitigation. This is achieved mainly by reducing the need of external feeds, while maximizing the use of local forage resources that otherwise would be difficult to valorize. Further reductions in the CF result when considering natural baseline emissions. The application of this new GHG accounting perspective could have relevant implications when aiming at climate neutrality of grazing-based ruminant systems.Purpose: Transhumance has rarely been analyzed through LCA approaches, and there is little evidence about its emissions level when conducted under different practices (by truck or on foot) or compared to sedentary livestock systems. Moreover, mobile pastoralism is strongly linked to natural resources by its seasonal grazing patterns, thereby occupying the niche of wild herbivores. Considering natural emission baselines in these ecosystems could have relevant effects when estimating their carbon footprint. Materials and methods: Inventory data of 20 sheep farms was collected to estimate the carbon footprint (CF) of lamb meat produced. Farms were divided into three sub-groups representing typical management practices in the region: (1) sedentary (SED), (2) transhumance by truck (THT), and (3) transhumance on foot (THF). Livestock GHG emissions were modeled according to herd structure and IPCC guidelines. Off-farm emissions from external feeds and fuels were accounted based on existent LCA databases. A natural baseline of wild herbivores was established from the population of red deer reported in a hunting preserve, previously considered to be a reference for the natural carrying capacity in Mediterranean ecosystems. GHG emissions of wild herbivores were estimated through two methods based on (1) IPCC guidelines and (2) allometric regression equations. Results and discussion: Carbon footprint ranged from 16.5 up to 26.9 kgCO2-eq/kg of lamb liveweight (LW). Significant differences were identified among sedentary and transhumant farms, the latter consistently showing lower CF values (SED: 25.1 kg CO2-eq/kg LW, THT: 18.3 kg CO2-eq/kg LW, THF: 18.2 kg CO2-eq/kg LW). Sedentary farms resulted in higher GHG emissions (+ 27%) and higher CO2 and N2O, contributions derived from the consumption of additional feeds. Both methods applied to compute emissions for wild herbivores led to similar results (25.3–26.8 Mg CO2-eq/km2), comparatively lower than estimation for transhumant sheep (47.7 Mg CO2-eq/km2). When considering natural baseline emissions, the CF of transhumant lamb meat is reduced by almost 30%, reaching values quite below those reported for intensive lamb production systems in Spain. Conclusions: From our results, mobility of grazing livestock can be considered as a strategy promoting climate change mitigation. This is achieved mainly by reducing the need of external feeds, while maximizing the use of local forage resources that otherwise would be difficult to valorize. Further reductions in the CF result when considering natural baseline emissions. The application of this new GHG accounting perspective could have relevant implications when aiming at climate neutrality of grazing-based ruminant systems

A generator of numerically-tailored and high-throughput accelerators for batched GEMMs

We propose a hardware generator of GEMM accelerators. Our generator produces vendor-agnostic HDL describing highly customizable systolic arrays guided by accuracy and energy efficiency goals. The generated arrays have three main novel aspects. First, the accelerators handle a large variety of computer number formats using intermediate representations based on our Sign Scale Significand (S3) format. Second, the processing elements perform all intermediate dot-product arithmetic operations required by the GEMM kernel without any intermediate rounding, which makes it possible to deliver better energy efficiency than state-of-the-art approaches while offering more accuracy and reproducible results. Third, our accelerators feature the Half-Speed Sink Down (HSSD) mechanism, which maximizes the overlap of host-accelerator data transfers with GEMM computations.We evaluate our automatically generated designs in a cutting-edge setup composed of a POWER9 host, CAPI (Coherent Accelerator Processor Interface) link, and a Virtex Ultrascale Plus FPGA. Arrays can operate at the speed of the link and saturate it to reach a 13GB/s throughput. Our fine-grain customization approach allows to cover a wide range of accuracy versus efficiency scenarios and can reach 0.65GOps/s/W while producing 1024 accurate bits or 148.7GOps/s/W with 6 accurate bits. Our configurations achieve up to 1613GOps/s system performance and power efficiencies of up to 240GOps/s/W for the FPGA. This automatic generator is the first being able to produce such a variety of designs. We improve the single-precision energy efficiency of state-of-the-art FPGA GEMM accelerators by 1.86×.This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 955606 Marc Casas is supported by Grant RYC-2017-23269 funded by MCIN/AEI/ 10.13039/501100011033 and by “ESF Investing in your future”Peer ReviewedPostprint (author's final draft

La transición política española a la democracia: un enfoque de Public Choice

En este artículo se trata de analizar y tratar de explicar porque la transición política española ocurrió de una forma tan rápida, pacífica, y consensuada. En este ánalisis se utilizan los instrumentos analíticos de la Teoría de la Elección Pública. En éste se parte de la hipótesis de que todos los agentes que participaron en la transición (el Rey, las Cortes franquistas, el Ejército y la burocracia, la Falange, la Iglesia Católica, todos los partidos políticos ilegales, todos los partidos nacionalistas, los sindicatos ilegales, el sindicato vertical, las asociaciones de empresarios y las potencias extranjeras) tenían tanto unos derechos de propiedad legales y/o reales (poderes) y restricciones o limitaciones. Todos ellos perseguían imponer su sistema de gobierno preferido a los demás agentes, pero su éxito o fracaso dependía de aquéllos. Pronto en el proceso todos se dieron cuenta de que ninguno tenía suficientes activos para imponer a los demás su sistema preferido de gobiemo. A partir de ahí, todos los agentes entraron en un rápido proceso de negociación, haciendo concesiones para obtener otras ventajas a cambio. Así nació la Constitución de 1978

La transición política española a la democracia: un enfoque de Public Choice

En este artículo se trata de analizar y tratar de explicar porque la transición política española ocurrió de una forma tan rápida, pacífica, y consensuada. En este ánalisis se utilizan los instrumentos analíticos de la Teoría de la Elección Pública. En éste se parte de la hipótesis de que todos los agentes que participaron en la transición (el Rey, las Cortes franquistas, el Ejército y la burocracia, la Falange, la Iglesia Católica, todos los partidos políticos ilegales, todos los partidos nacionalistas, los sindicatos ilegales, el sindicato vertical, las asociaciones de empresarios y las potencias extranjeras) tenían tanto unos derechos de propiedad legales y/o reales (poderes) y restricciones o limitaciones. Todos ellos perseguían imponer su sistema de gobierno preferido a los demás agentes, pero su éxito o fracaso dependía de aquéllos. Pronto en el proceso todos se dieron cuenta de que ninguno tenía suficientes activos para imponer a los demás su sistema preferido de gobiemo. A partir de ahí, todos los agentes entraron en un rápido proceso de negociación, haciendo concesiones para obtener otras ventajas a cambio. Así nació la Constitución de 1978

Application of the finite difference method in the study of wave propagation in a borehole

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric and Planetary Sciences, 1984.Microfiche copy available in Archives and Science.Bibliography: leaves 41-43.by Federico Pardo Casas.M.S

The Study of Wave Propagation in a Borehole Using the Finite Difference Method

Synthetic microseismograms of elastic wave propagation in a fluid-filled borehole were generated using both the finite difference technique and the discrete wavenumber summation technique. For the finite difference calculations, the solid-liquid borehole boundary was handled as a sharp boundary using a second order Taylor expansion of the displacements. and additionally, a rigid solid-liquid sharp interface is used to model the existence of the logging tool. A heterogeneous formulation was used to handle variations in formation properties. The finite difference grid has absorbing boundaries on two sides and axes of symmetry on the remaining two sides. A grid size no less than 10 points per wavelength was used. The results from the finite difference modeling were compared with the synthetic microseismograms generated by the discrete wavenumber summation method. A detailed comparison between the microseismograms generated by the two methods showed that the body waves (refracted P and S waves) are identical, while the guided waves showed a slight difference in both phase and amplitude. These differences are believed to be due to the dispersion generated by the finite difference method. We have studied the depth of investigation of the retracted body waves in an invaded or damaged borehole using the conventional ray theory approach and compared the results to those obtained by the finite difference method. The results show that the minimum source-receiver separation necessary to observe the unaltered formation depends on both the velocity gradient and the lowest and highest velocity of the damaged zone. Such an investigation shows us the importance of the length of the logging tool to be able to "see" past the damaged and invaded zone, and thus enables us to measure the true formation properties, as well as to estimate the depth of the damaged or invaded zone