Return to Dollar, Generalized Distance Function and the Fisher Productivity Index

Exploring the duality between a return to dollar definition of profit and the generalized distance function we establish the relationship between the Laspeyres, Paasche and Fisher productivity indexes and their alternative Malmquist indexes counterparts. By proceeding this way, we propose a consistent decomposition of these productivity indexes into two mutually exclusive components. A technical component represented by the Malmquist index and an economical component which can be identified with the contribution that allocative criteria make to productivity change. With regard to the Fisher index, we indicate how researchers can further decompose the Malmquist technical component rendering explicit the sources of productivity change. We also show how the proposed model can be implemented by means of Data Envelopment Analysis techniques, and illustrate the empirical process with an example data set.Generalized Distance Function; Return to Dollar; Fisher and Malmquist Productivity Indexes

Interacciones entre fármacos de libre venta y de prescripción.

Tesis (Químico Farmacéutico)Los medicamentos son una de las herramientas terapéuticas más utilizadas en la práctica de la medicina, cuyo uso de manera apropiada permite la obtención de importantes beneficios sanitarios representados por la prevención, diagnóstico, curación, atenuación y tratamiento de las enfermedades y sus síntomas. No obstante, su utilización puede llevar a problemas importantes de morbilidad y de mortalidad. Las reacciones adversas son el resultado de una interacción entre el organismo el medicamento y una serie de factores extrínsecos adicionales. Influyen, por tanto, los factores propios, los ambientales, los ligados al propio enfermo (procesos farmacocinéticos, edad, estado patológico) y las asociaciones entre medicamentos. Estas últimas pueden dar lugar a i'11teracciones farmacológicas. Las cuales son necesarias conocer, para predecir las probables interacciones y así advertir a la población y a los profesionales del área de la salud, sobre los potenciales riesgos. Dado que no existen estudios en farmacia comunitaria sobre las interacciones farmacológicas potenciales. Se realizó un estudio observacional, transversal y descriptivo, mediante una encuesta aplicada a 731 clientes-pacientes que frecuentaban los locales de Farmacias Ahumada, de la Provincia de Santiago, con el objetivo de estudiar las posibles interacciones que pudiesen presentarse en la administración conjunta de fármacos de prescripción y de libre venta. De las encuestas realizadas se obtuvo que: el 76,34% de los clientes-pacientes se administra 3 o 4 medicamentos concomitantemente; el consumo promedio fue de 3,92 medicamentos; del total de fármacos el 59,97% corresponde a analgésicos, cardiovasculares y antiinfecciosos; las interacciones de severidad mayor corresponden a fármacos analgésicos + sistema nervioso central; las interacciones más frecuentes corresponden a fármacos analgésicos + cardiovasculares..

Motive of the SL4SL_4-character variety of torus knots

In this paper, we compute the motive of the character variety of representations of the fundamental group of the complement of an arbitrary torus knot into $SL_4(k)$, for any algebraically closed field $k$. For that purpose, we introduce a stratification of the variety in terms of the type of a canonical filtration attached to any representation. This allows us to reduce the computation of the motive to a combinatorial problem.Comment: 35 pages. Note: download source for the output of all the strata as separate fil

Generic Battery Model based on a Parametric Implementation

Batteries are a common element used in many electronic applications. Therefore, the analysis and simulation of these applications requires a battery model in order to validate the behavior of the whole system. Since batteries are based on different technologies, a modeling approach valid for any technology is a potential good alternative. Since there are similarities among the different technologies, it is possible to address the modeling of batteries as generic energy storage elements with particular differences. This work presents a battery model valid for different technologies based on a parametric implementation

Representation variety for the rank one affine group

The aim of this paper is to study the virtual classes of representation varieties of surface groups onto the rank one affine group. We perform this calculation by three different approaches: the geometric method, based on stratifying the representation variety into simpler pieces; the arithmetic method, focused on counting their number of points over finite fields; and the quantum method, which performs the computation by means of a Topological Quantum Field Theory. We also discuss the corresponding moduli spaces of representations and character varieties, which turn out to be non-equivalent due to the non-reductiveness of the underlying group.Comment: 28 pages, 3 figures. References adde

Modelling the spatial and sectoral benefits of productivity enhancing innovations using a transport oriented multiregional IO framework: the ‘megatruck’ in Spain

We render operational the model outlined by Carter (1990) via the introduction of the research methods necessary for studying the spatial and sectoral (upstream and downstream) benefits of productivity-enhancing innovations within a real interregional input–output framework. As case study we examine the reduction in production costs derived from the adoption of longer and heavier vehicles in freight road transportation. We exploit a new Spanish regional table including a detailed disaggregation of the transportation sector. The productivity gains at the national level, resulting from a 30% reduction in transport costs, amount to 2.95% of the GVA at market prices. Results show that firms operating in this niche market appropriate most of the gross operation surplus (which increases by 10%), consistent with the existence of market power. The remaining transportation sectors see profits slightly worsened, suggesting limited substitution effects. A high regional heterogeneity exists because of the different input–output structuresThis work was supported by Ministerio de Fomento, Spain: [Grant Number P42-08

On the advantages of symmetrical over asymmetrical multiphase AC drives with even phase number using direct controllers

Multiphase electric drives offer attractive advantages over conventional three-phase systems. Some of the benefits are shared by all multiphase configurations, but the performance can be highly affected by the specific location of the stator windings. While the asymmetrical configuration has been traditionally a popular choice, the symmetrical disposition in even-phase machines has a main advantage: it is possible to generate α – β voltages without any contribution in different x – y subspaces. This article explains and demonstrates this feature for the general case of distributed-winding symmetrical n -phase machines, with n being an even number. Fortunately, direct controllers can benefit from this characteristic by exclusively selecting voltage states with only α – β voltage production. To illustrate this capability, a finite-control-set model predictive control (FCS-MPC) using these special voltage states is also suggested in this work for symmetrical six-phase electric drives. This approach provides a greater simplicity and much less current distortion than in standard FCS-MPC for the asymmetrical configuration. Comparative experimental results confirm the minimal x – y injection of symmetrical configurations thanks to the proposed control actions (i.e., voltage states)Agencia Estatal de Investigación | Ref. RTI2018-096151-B-I00Xunta de Galicia | Ref. ED431F 2020/07Agencia Estatal de Investigación | Ref. RYC2018-024407-IAgencia Estatal de Investigación | Ref. PID2019-105612RB-I0

Uso de Herramientas de Simulación Electrónica como Apoyo Docente en Electrónica de Potencia

El objetivo de este trabajo es el mostrar cómo las herramientas de simulación electrónica pueden apoyar didácticamente al profesor en la enseñanza de asignaturas relacionadas con la electrónica de potencia. Se va a presentar un ejemplo guiado de uso de este tipo de herramientas en para el diseño del circuito de control de un convertidor CC/CC para una aplicación de alimentación dual en el entorno del automóvil. Para diseñar el circuito de control es necesario determinar en primer lugar la respuesta en frecuencia del convertidor. Se va a hacer uso del programa Simplorer con la biblioteca SMPS Library como herramienta de simulación para este ejemplo. Existen modelos en dicha biblioteca que permiten obtener la respuesta en frecuencia del circuito de forma directa. Este artículo explica los pasos que deben seguirse para diseñar el circuito de control de un convertidor Buck multi-fase usando tanto modelos promediados como modelos conmutados