Peltzman on Ice: Evidence on Compensating Behavior Using a Natural Experiment from Ice Hockey

We provide evidence of the Peltzman effect by tracking the professional path of each hockey player that ended up in the National Hockey League from 2001 to 2006. We take advantage of the fact that visor use has not always been compulsory throughout a player's career, which allows us to compare the change in behavior of users and non-users of visors when they are forced to use them. We find that whereas the average penalty minutes per game is 0.8, visors cause a substantial increase of 0.2 penalty minutes per game. Players become more aggressive when forced to wear a visor, partially offsetting its protective effect and creating potential spillover effects to other players.Peltzman Effect, Ice Hockey, Compensating Behavior

Aprendizajes significativos de la práctica etnocomunitaria en la Institución educativa empresarial

El siguiente escrito, reconociendo la practica Etnocomunitaria como el escenario de praxis que conduce a la labor profesional integra, a la luz de lo visto en la asignatura “Gestión y Desarrollo de Proyecto de Grado”, pretende reflexionar alrededor de lo vivido en la práctica Etnocomunitaria en la Institución Educativa Empresarial, teniendo en cuenta los aportes de los autores David Paul Ausubel1 alrededor del “Aprendizaje Significativo” y Marco Raúl Mejía respecto a la “Investigación como Estrategia Pedagógica”. En consecuencia, en un primer momento se realiza la contextualización del escenario de práctica partiendo de la reflexión que deviene de las condiciones particulares de éste, en un segundo momento se prosigue con los planteamientos teóricos y conceptuales que sustentaron el quehacer educativo y comunitario desarrollado, lo cual, se interrelaciona con la reflexión etnoeducativa, que permitió el análisis crítico de la experiencia vivida y como se generó un proceso dialógico y dialéctico

Alcance Jurisprudencial de la iniciativa legislativa reservada del Gobierno Nacional

A pesar de que en el constitucionalismo colombiano la regla general es el principio de libertad de iniciativa legislativa de los miembros del Congreso en el proceso de formación de las leyes, la Constitución ha establecido respecto de ciertas materias que la iniciativa corresponde de manera exclusiva al Gobierno Nacional. En ese orden de ideas, el presente artículo expone los argumentos empleados por la Corte Constitucional para precisar el alcance de la aplicación de las causales que limita la iniciativa legislativa en forma reservada al Gobierno Nacional

Descongestiónar la justicia administrativa, soluciones para un problema endémico

La congestión de los juzgados y tribunales administrativos es uno de los problemas del sistema judicial colombiano. La investigación llevada a cabo en los despachos judiciales de Bogotá, Medellín, Cali, Cartagena, Tunja y Bucaramanga busca encontrar las causas del represamiento. Entre éstas se encuentran la falta de recursos, la ineficacia de la conciliación y el trámite excesivo de demandas, muchas de ellas innecesarias. Finalmente, sugiere que la descongestión de la justicia administrativa se puede lograr a través de una estrategia que agilice los procesos de toma de decisión y una serie de medidas que eviten el trámite innecesario de demandas

Adaptación del modelo de Estado y del derecho nacional a la globalización económica y compatibilización con la vigencia del estado social de derecho

La globalización económica ha determinado una redefinición del papel del Estado, que de intervencionista y prestador pasa a regulador y garante de la prestación, determinando una adaptación del régimen jurídico aplicable por los Estados nacionales y propiciando la creación de un nuevo orden en el ámbito global, que pone en entredicho la capacidad actual de las organizaciones políticas de las sociedades para cumplir con los cometidos del Estado social, cuya vía de resolución parece ser la calidad del sistema regulatorio

Pem fuel cell modeling and converters design for a 48 v dc power bus

Fuel cells (FC) are electrochemical devices that directly convert the chemical energy of a fuel into electricity. Power systems based on proton exchange membrane fuel cell (PEMFC) technology have been the object of increasing attention in recent years as they appear very promising in both stationary and mobile applications due to their high efficiency, low operating temperature allowing fast startup, high power density, solid electrolyte, long cell and stack life, low corrosion, excellent dynamic response with respect to the other FCs, and nonpolluting emissions to the environment if the hydrogen is obtained from renewable sources. The output-voltage characteristic in a PEMFC is limited by the mechanical devices which are used for regulating the air flow in its cathode, the hydrogen flow in its anode, its inner temperature, and the humidity of the air supplied to it. Usually, the FC time constants are dominated by the fuel delivery system, in particular by the slow dynamics of the compressor responsible for supplying the oxygen. As a consequence, a fast load transient demand could cause a high voltage drop in a short time known as oxygen starvation phenomenon that is harmful for the FC. Thus, FCs are considered as a slow dynamic response equipment with respect to the load transient requirements. Therefore, batteries, ultracapacitors or other auxiliary power sources are needed to support the operation of the FC in order to ensure a fast response to any load power transient. The resulting systems, known as FC hybrid systems, can limit the slope of the current or the power generated by the FC with the use of current-controlled dc-dc converters. In this way, the reactant gas starvation phenomena can be avoided and the system can operate with higher efficiency. The purpose of this thesis is the design of a DC-DC converter suitable to interconnect all the different elements in a PEMFC-hybrid 48-V DC bus. Since the converter could be placed between elements with very different voltage levels, a buck-boost structure has been selected. Especially to fulfill the low ripple requirements of the PEMFCs, but also those of the auxiliary storage elements and loads, our structure has inductors in series at both its input and its output. Magnetically coupling these inductors and adding a damping network to its intermediate capacitor we have designed an easily controllable converter with second-order-buck-like dominant dynamics. This new proposed topology has high efficiency and wide bandwidth acting either as a voltage or as a current regulator. The magnetic coupling allows to control with similar performances the input or the output inductor currents. This characteristic is very useful because the designed current-controlled converter is able to withstand shortcircuits at its output and, when connected to the FC, it facilitates to regulate the current extracted from the FC to avoid the oxygen starvation phenomenon. Testing in a safe way the converter connected to the FC required to build an FC simulator that was subsequently improved by developing an emulator that offered real-time processing and oxygen-starvation indication. To study the developed converters and emulators with different brands of PEMFCs it was necessary to reactivate long-time inactive Palcan FCs. Since the results provided by the manual reactivation procedure were unsatisfactory, an automatic reactivation system has been developed as a complementary study of the thesis.En esta tesis se avanzo en el diseño de un bus DC de 48 V que utiliza como elemento principal de generación de energía eléctrica una pila de combustible. Debido a que la dinámica de las pilas de combustible están limitadas por sus elementos mecánicos auxiliares de control una variación rápida de una carga conectada a ella puede ocasionar daños. Es por esto que es necesario utilizar elementos almacenadores de energía que puedan suministrar estas rápidas variaciones de carga y convertidores para que gestionen de una forma controlada la potencia del bus DC. Durante la realización de pruebas de los convertidores es de gran importancia utilizar emuladores o simuladores de pilas de combustibles, esto nos permite de una forma económica y segura realizar pruebas criticas antes de conectar los convertidores a la pila. Adicionalmente una nueva topologia de convertidor fue presentada y ésta gestionará la potencia en el bu

Independence and Professionalism in the Institutional Design of Supreme Audit Institutions in Latin America and the Caribbean

The primary purpose of this research is to determine whether the institutional design of supreme audit institutions (SAIs) in Latin America and the Caribbean meets the criteria of independence and professionalism established in the principles of the Lima and Mexico Declarations of the International Organisation of Supreme Audit Institutions (INTOSAI) as a condition for the development of an efficient external governmental audit whose results may provide input for improved performance by audited bodies for the benefit of society. In accordance with the descriptive variables defined for this paper and in function of the information sources consulted, we were able to establish that the institutional design of the regional SAIs fulfil these principles. Nevertheless, because this conclusion is based on an analysis of the constitutional and legal norms that regulate SAIs and the documents generated by SAIs, such as auditing guidelines and manuals, management reports and audit reports, we cannot say that this effectively means that SAIs meet the parameters of independence and professionalism intended by the INTOSAI. Instead, political, institutional and communication challenges have arisen that must be overcome to move from formal compliance to real application. © 2015 by De Gruyter

Regulatory Protective Measures and Risky Behavior: Evidence from Ice Hockey

We provide evidence supporting the Peltzman effect, by which individuals required to wear protective gear end up taking additional risks that potentially offset the intended aim of the device. We take advantage of the fact that wearing a visor—a protective device in Ice Hockey—is mandatory in European, minor, and junior leagues but not in the NHL. This allows us to estimate the impact of wearing a visor by comparing the behavior in the NHL and other leagues of players who always wear a visor with that of players who wear one only when it is required. We find that when players are forced to wear a visor their behavior becomes more risky, earning an additional 0.19 penalty in minutes per game (compared to the average 1.14 penalty in minutes in our sample). We estimate an even larger effect of visors when we focus on players who were forced to use one during the 2004 season, when the NHL canceled its regular season and players had to move to European leagues temporarily. These estimates are not driven by players’ observable attributes, playing style, or other differences across leagues

The Canadian Cooperation Policy in the Assistance of the Anti personnel Landmines Victims in Colombia

The landmines are a subject of world-wide concern since the 1990’s when the in¬ternational community undertook a campaign for their ban. The prohibition came with the Ottawa Convention, signed by two-thirds of the UN Members. However today, more than ten years after that declaration, many States, including Colom¬bia, face the threat of landmines. As international cooperation is one of the instru¬ments contained in the Convention, this article reviews the cooperation policies implemented by Canada as one of the nations committed in the search for a solu¬tion to Colombian landmine problem