2,388 research outputs found
ALLOCATION PROBLEMS WITH INDIVISIBILITIES WHEN PREFERENCES ARE SINGLE-PEAKED
We consider allocation problems with indivisible goods when agents’ preferences are single-peaked. Two natural procedures (up methods and temporary satisfaction methods) are proposed to solve these problems. They are constructed by using priority methods on the cartesian product of agents and integer numbers, interpreted either as peaks or opposite peaks. Thus, two families of solutions arise this way. Our two families of solutions satisfy properties very much related to some well-known properties studied in the case of perfectly divisible goods, and they have a strong relationship with the continuous uniform and equal-distance rules, respectively.Allocation problem, indivisibilities, single-peaked preferences, temporary satisfaction method, up method.
EGALITARIAN RULES IN CLAIMS PROBLEMS WITH INDIVISIBLE GOODS
In this work we deal with rationing problems. In particular with claims problems with indivisible goods, that is, problems in which a certain amount of indivisible units (of an homogeneous good), has to be distributed among a group of agents, when this amount is not enough to satisfy agents' demands. We define discrete rules to solve those problems that involve notions of fairness similar to those supporting the constrained-equal awards and the constrained-equal losses rules in the continuous case. Axiomatic characterizations of those solutions are provided.indivisible goods, claims problems, equal awards solution, equal losses solution.
Application of Computational Fluid Dynamics to the simulation and optimization of multi-environment bioreactors for wastewater treatment
RESUMEN: Los reactores multi-ambiente representan una alternativa innovadora para simplificar los trenes de tratamiento convencionales de Eliminación Biológica de Nutrientes (EBN), ya que son más compactos y pueden adaptarse a los requerimientos de calidad existentes. En concreto, el reactor AnoxAn es capaz de integrar las zonas anaerobia y anóxica del proceso convencional de EBN en un único reactor de flujo ascendente. Sin embargo, su zonificación multi-ambiental y la configuración de elementos singulares dan lugar a un comportamiento hidrodinámico complejo que interfiere en el funcionamiento óptimo del reactor. En por ello que, en la presente tesis doctoral, se realiza un análisis exhaustivo de la hidrodinámica de AnoxAn, asà como un estudio la influencia de la misma en la eficiencia biológica del proceso. Para ello, se desarrolla una herramienta numérica basada en Dinámica de Fluidos Computacional (CFD) con el software de código abierto OpenFOAM®, y se propone una metodologÃa para la optimización hidrodinámica de reactores multi-ambiente. Los resultados obtenidos en este trabajo han contribuido al desarrollo tecnológico y operacional de AnoxAn.ABSTRACT: Multi-environment reactors are an innovative alternative to simplify conventional Biological Nutrient Removal (BNR) treatment trains as they are more compact and can adapt to existing quality requirements. Concretely, AnoxAn unifies the anaerobic and anoxic zones of conventional BNR processes in a continuous upflow sludge blanket reactor. However, the multi environmental zoning and singular elements configuration give rise to a complex hydrodynamic behaviour that interferes in the desired biological operation of the reactor. Therefore, in this thesis, a comprehensive hydrodynamic assessment of AnoxAn is carried out, and the influence of the hydraulic behaviour on the biological efficiency of the process is evaluated. For that purpose, a Computational Fluid Dynamics (CFD) based numerical tool is developed with the open source toolbox OpenFOAM®, and a hydrodynamic optimization methodology for multi-environment reactors is proposed. The results obtained in this work have contributed to the development of technological and operational improvements of AnoxAn.A la Universidad de Cantabria primero (PRE03, CVE-2016-11670), y al Ministerio de
Educación, Cultura y Deporte del Gobierno de España después (FPU16-05036), por
proporcionarme mediante beca la financiación necesaria para la consecución de esta
tesis doctoral
Optimal Carbon Taxes for Emissions Targets in the Electricity Sector
The most dangerous effects of anthropogenic climate change can be mitigated
by using emissions taxes or other regulatory interventions to reduce greenhouse
gas (GHG) emissions. This paper takes a regulatory viewpoint and describes the
Weighted Sum Bisection method to determine the lowest emission tax rate that
can reduce the anticipated emissions of the power sector below a prescribed,
regulatorily-defined target. This bi-level method accounts for a variety of
operating conditions via stochastic programming and remains computationally
tractable for realistically large planning test systems, even when binary
commitment decisions and multi-period constraints on conventional generators
are considered.
Case studies on a modified ISO New England test system demonstrate that this
method reliably finds the minimum tax rate that meets emissions targets. In
addition, it investigates the relationship between system investments and the
tax-setting process. Introducing GHG emissions taxes increases the value
proposition for investment in new cleaner generation, transmission, and energy
efficiency; conversely, investing in these technologies reduces the tax rate
required to reach a given emissions target
- …