Thermodynamics of firms' growth

The distribution of firms' growth and firms' sizes is a topic under intense scrutiny. In this paper we show that a thermodynamic model based on the Maximum Entropy Principle, with dynamical prior information, can be constructed that adequately describes the dynamics and distribution of firms' growth. Our theoretical framework is tested against a comprehensive data-base of Spanish firms, which covers to a very large extent Spain's economic activity with a total of 1,155,142 firms evolving along a full decade. We show that the empirical exponent of Pareto's law, a rule often observed in the rank distribution of large-size firms, is explained by the capacity of the economic system for creating/destroying firms, and can be used to measure the health of a capitalist-based economy. Indeed, our model predicts that when the exponent is larger that 1, creation of firms is favored; when it is smaller that 1, destruction of firms is favored instead; and when it equals 1 (matching Zipf's law), the system is in a full macroeconomic equilibrium, entailing "free" creation and/or destruction of firms. For medium and smaller firm-sizes, the dynamical regime changes; the whole distribution can no longer be fitted to a single simple analytic form and numerical prediction is required. Our model constitutes the basis of a full predictive framework for the economic evolution of an ensemble of firms that can be potentially used to develop simulations and test hypothetical scenarios, as economic crisis or the response to specific policy measures

Aerodynamic Shape Multi-Objective Optimization for SAE Aero Design Competition Aircraft

The SAE Regular Class Aero Design Competition requires students to design a radio-controlled aircraft with limits to the aircraft power consumption, take-off distance, and wingspan, while maximizing the amount of payload it can carry. As a result, the aircraft should be designed subject to these simultaneous and contradicting objectives: 1) minimize the aerodynamic drag force, 2) minimize the aerodynamic pitching moment, and 3) maximize the aerodynamic lift force. In this study, we optimized the geometric design variables of a biplane configuration using 3D aerodynamic analysis using the ANSYS Fluent. Coefficients of lift, drag, and pitching moment were determined from the completed 3D CFD simulations. Extracted coefficients were used in modeFRONTIER multi-objective optimization software to find a set of non-dominated (Pareto-optimal or best trade-off) optimized 3D aircraft shapes from which the winner was selected based to the desired plane performance

On the exposure to mobile phone radiation in trains

This report presents theoretical estimates of the Power Density levels which may be reached inside trains. Two possible sources of high levels of radiation are discussed. The first one arises since the walls of the wagons are metallic and therefore bounce back almost all radiation impinging on them. The second is due to the simultaneous emission of a seemingly large number of nearby telephones. The theoretical study presented here shows that Power Densities stay at values below reference levels always.Comment: 9 pages, 1 figur

Multi-Disciplinary Analysis and Design Optimization of a 3D Model Airplane

The SAE Regular Class Aero Design Competition requires students to design a model scale aircraft with limits to the power consumption, take-off distance, and wingspan, while maximizing the amount of payload it can carry. As a result, the aircraft should be designed subject to these simultaneous and contradicting objectives: 1) minimize the drag, 2) minimize the pitching moment, and 3) maximize the lift. This study aims to determine five optimized geometric design variables: 1) incidence angle of the wing, 2) incidence angle of the horizontal tail, 3) distance between the wing and the tail, 4) sweep angle of the winglets, and 5) height of the winglets. To determine the incidence angles, an airplane was initially designed using the highly cambered S1223 airfoil for the wing and the inverted NACA2409 airfoil for the tail. The same fuselage shape was used for all configurations where the only changes were the incidence angles and the distance between the wing and tail. Wing incidence angle was varied in the range 0° to 10°. Tail incidence angle was varied in the range -5° to 0°. Horizontal distance between the wing and the horizontal tail was varied in the range 4L to 10L, where L is the wing chord length. Each random combination of the design variables defined its own 3D aircraft configuration. Aerodynamics of each of these 3D aircraft shapes including their coefficients of lift, drag, and pitching moment were calculated using ANSYS Fluent software. Fourty such aircraft configurations were analyzed before the results were inputted into modeFrontier software to perform the multi-objective optimization study resulting in a Pareto-optimized set of the best trade-off 3D airplane geometries having the best combination of incidence angles and the wing-tail distance to achieve the three stated goals. Structural 3D analysis and static and dynamic stability analyses were also performed

Status report of the baseline collimation system of CLIC. Part II

Important efforts have recently been dedicated to the characterisation and improvement of the design of the post-linac collimation system of the Compact Linear Collider (CLIC). This system consists of two sections: one dedicated to the collimation of off-energy particles and another one for betatron collimation. The energy collimation system is further conceived as protection system against damage by errant beams. In this respect, special attention is paid to the optimisation of the energy collimator design. The material and the physical parameters of the energy collimators are selected to withstand the impact of an entire bunch train. Concerning the betatron collimation section, different aspects of the design have been optimised: the transverse collimation depths have been recalculated in order to reduce the collimator wakefield effects while maintaining a good efficiency in cleaning the undesired beam halo; the geometric design of the spoilers has been reviewed to minimise wakefields; in addition, the optics design has been optimised to improve the collimation efficiency. This report presents the current status of the the post-linac collimation system of CLIC. Part II is mainly dedicated to the study of the betatron collimation system and collimator wakefield effects.Comment: 25 pages, 13 figure

Rediseño de la asignatura Mecánica I para su impertición en modalidad b-learning.

Esta experiencia se enmarca dentro del conjunto de Proyectos coordinados de Innovación Educativa de distintas Escuelas de la Universidad Politécnica de Madrid (UPM) cuyo objetivo principal es la generación y adaptación de materiales didácticos para transformar de forma progresiva la docencia a formato semi-presencial o completamente a distancia. Como recursos educativos se han utilizado los Objetos de Aprendizaje (OA). En este trabajo se describe la experiencia en la asignatura de Mecánica I y se muestran algunos de los materiales preparados. También se presenta los resultados académicos alcanzados por los alumnos y la valoración cualitativa que hacen los estudiantes respecto a disponer de objetos digitales de aprendizaje

Migration diplomacy in a de facto destination country: Morocco’s new intermestic migration policy and international socialization by/with the EU

This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this recordThis article examines Morocco’s migration diplomacy with a focus on the New Migration Policy (NMP) it launched in 2013 as a destination country. It argues that the NMP serves the objectives of Moroccan foreign policy towards both Africa and the EU, as international socialization by/with the latter remains a primary driving force for the country’s migration policies. The main recent change in Morocco-EU socialization has been a return from norm-driven role playing to an overt exhibition of rational choice and a transactional attitude around migration/border control practices – while role playing has been reoriented towards Africa and the wider international community