An empirical way to correct some drawbacks of mulliken population analysis

Indexación: ScieloThe problem of negative electronic populations and of occupation numbers greater than 2 has plagued Mulliken Population Analysis since the very beginning. Through the analysis of three model molecular systems, several basis sets and the relevant literature, we conclude that there is not enough evidence to assign the origin of these errors to the self-consistent scheme, to Mulliken's partition, to the basis set structure or to a combination of these. As Mulliken Population Analysis is still widely used, we have developed an empirical method to eliminate negative electronic populations and occupation numbers greater than 2. This method can be used for any partition of the electron density (not only Mulliken's), for any basis set and for any LCAO-MO methodology (semiempirical or ab initio). Finally, the method does not produce any change in the original atomic net charges.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072009000400036&lng=es&nrm=is

Bargaining and Incentive Compatibility: A Pareto Frontier Approach.

Two agents negotiate, according to the Nash bargaining solution, over the allocation of a single (divisible) commodity (or multiple commodities with fixed ordinal preferences). It has been shown that in this situation agents find dominant to report their least risk averse utility functions. This result depends crucially on the fact that in this kind of "distortion game", agents have been restricted to report risk-averse utility functions. This paper studies the distortion game originated when agents are also allowed to claim non risk-averse utility functions. Contrasting with previous literature, we find multiple Nash equilibria, multiple payo outcomes and the existence of a first-mover advantage.

An Extension of the Core solution Concept.

A solution concept for cooperative games, the extended core, is introduced. This concept is always nonempty yet coincides with the core whenever it is nonempty. Moreover, a non-cooperative framework can generate the extended core. Every transferable utility game is associated with a two-player zero-sum non-cooperative game. The min-max values of the associated zerosum games characterize when cooperative games have nonempty cores. If the core is empty, the min-max value determines how an exogenous regulator can impose costs on proper coalition formation so that there are no incentives to deviate from extended core imputations, which are necessarily feasible in the original game. In order to choose among the imputations belonging to the extended core, a proportional version of the nucleolus is proposed as a selection device.

Non-Minimal Flavored S3⊗Z2{\bf S}_{3}\otimes {\bf Z}_{2} Left-Right Symmetric Model

We propose a non-minimal left-right symmetric model (LRSM) with Parity Symmetry where the fermion mixings arise as result of imposing an ${\bf S}_{3}\otimes {\bf Z}_{2}$ flavor symmetry, and an extra ${\bf Z}^{e}_{2}$ symmetry is considered to suppress some Yukawa couplings in the lepton sector. As a consequence, the effective neutrino mass matrix possesses approximately the $\mu-\tau$ symmetry. The breaking of the $\mu-\tau$ symmetry induces sizable non zero $\theta_{13}$, and the deviation of $\theta_{23}$ from $45^{\circ}$ is strongly controlled by an $\epsilon$ free parameter and the complex neutrino masses. Then, an analytic study on the extreme Majorana phases is done since these turn out to be relevant to enhance or suppress the reactor and atmospheric angle. So that we have constrained the parameter space for the $\epsilon$ parameter and the lightest neutrino mass that accommodate the mixing angles. The highlighted results are: a) the normal hierarchy is ruled out since the reactor angle comes out being tiny, for any values of the Majorana phases; b) for the inverted hierarchy there is one combination in the extreme phases where the values of the reactor and atmospheric angles are compatible up to $2, 3~\sigma$ of C. L., but the parameter space is tight; c) the model favors the degenerate ordering for one combination in the extreme Majorana phases. In this case, the reactor and atmospheric angle are compatible with the experimental data for a large set of values of the free parameters. Therefore, this model may be testable by the future result that the Nova and KamLAND-Zen collaborations will provide.Comment: Version three. I added references and corrected typos. 19 pages. All figures replaced, section II changed. Analytic study improved. Conclusions unchange

The Politics of Abstract Art. Forma 1 and the Italian Communist Party

Este artículo examina el papel del grupo de artistas abstractos Forma 1 en relación con la política cultural del Partido Comunista Italiano durante la posguerra, como ejemplo de los intentos de superar la dicotomía establecida en Italia entre arte abstracto y realismo socialista y producir una alternativa a la confrontación entre ambos discursos estéticos. Mientras los artistas realistas socialistas subrayaban la necesidad de expresar contenidos políticos explícitos con un estilo que asegurase su máxima legibilidad para una audiencia de masas, los artistas de Forma 1 argumentaban que la abstracción significaba una crítica de la representación pictórica que podía contribuir a la crítica de la ideología burguesa, armonizando de este modo el marxismo con los desarrollos artísticos más avanzados. El PCI, por su parte, basaba su política artística en amplias alianzas de artistas e intelectuales antifascistas, que cada vez eran más difíciles de mantener en el clima de creciente confrontación política y cultural que siguió a la II Guerra Mundial

Memoria metodológica del plan exportador para la Pyme antioqueña Bienestar y Nutrición S. A. S. - Ma´Snacks para su estrategia comercial en el marco del Grupo Antioquia Exporta Más

En el 2015 se presentaron en Colombia los más bajos índices de comercio exterior de los últimos cinco años principalmente por la disminución de las exportaciones de petróleo y sus derivados; este sector presentó una variación del -31,3 % de un total de -34,9 % (Banco de la República de Colombia, 2016) -- Para atender esta situación, el Grupo Antioquia Exporta Más, iniciativa público-privada, pretende liderar la estructuración e implementación de una estrategia regional exportadora que apalanque no solo la competitividad de las pymes de la región, sino que contribuya a la meta nacional trazada para el año 2018 de llevar a las exportaciones no minero-energéticas a USD 30.000 millones; el objetivo, además, es que en esta meta Antioquia represente el 15,7 % (USD 4.726 millones), según lo reportado por el Grupo Antioquia Exporta Más (2015) -- Esta estrategia también busca potenciar otros sectores y mercados más promisorios en los que el departamento juega un papel importante, ya que en materia de comercio exterior se ha caracterizado por ser dinámico y por tener una importante participación en el total del país, tanto es así que en la actualidad ocupa el primer puesto (DANE, Departamento Administrativo Nacional de Estadísticas, 2016) -- A esta iniciativa se vincula la Universidad EAFIT con la participación de consultores reconocidos y estudiantes de posgrados, quienes intervinieron pymes cuyas exportaciones no excedan los USD 20.000 para diseñar el plan exportador con base en la metodología del Grupo Antioquia Exporta Más -- Una de las empresas seleccionadas para la consultoría, cuyo objetivo principal es diseñar un plan exportador para la empresa Bienestar y Nutrición S. A. S., empresa dedicada al desarrollo, producción y comercialización de snack saludables fortificados, y especializada en productos horneado

Rui López de Segura contra el Brocense*

My essay analyses the critique made by the 16th century humanist Rui López de Segura in his gramatical work Grammaticae Institutiones on some of El Brocense´s grammatical ideas such as noun gender or case morphology and so on. In a closer reading of the Brocense´s works, however, that were available to Rui Lopez it can be ascertained that most of his critique has no scientific ground and reveals to a certain degree some personal bias. Besides, some specific data extracted from these invectives lead us into thinking that the Grammaticae Institutiones text that we are currently working with was published later than 1563, date shown on the front cover.My essay analyses the critique made by the 16th century humanist Rui López de Segura in his gramatical work Grammaticae Institutiones on some of El Brocense´s grammatical ideas such as noun gender or case morphology and so on. In a closer reading of the Brocense´s works, however, that were available to Rui Lopez it can be ascertained that most of his critique has no scientific ground and reveals to a certain degree some personal bias. Besides, some specific data extracted from these invectives lead us into thinking that the Grammaticae Institutiones text that we are currently working with was published later than 1563, date shown on the front cover.My essay analyses the critique made by the 16th century humanist Rui López de Segura in his gramatical work Grammaticae Institutiones on some of El Brocense´s grammatical ideas such as noun gender or case morphology and so on. In a closer reading of the Brocense´s works, however, that were available to Rui Lopez it can be ascertained that most of his critique has no scientific ground and reveals to a certain degree some personal bias. Besides, some specific data extracted from these invectives lead us into thinking that the Grammaticae Institutiones text that we are currently working with was published later than 1563, date shown on the front cover.My essay analyses the critique made by the 16th century humanist Rui López de Segura in his gramatical work Grammaticae Institutiones on some of El Brocense´s grammatical ideas such as noun gender or case morphology and so on. In a closer reading of the Brocense´s works, however, that were available to Rui Lopez it can be ascertained that most of his critique has no scientific ground and reveals to a certain degree some personal bias. Besides, some specific data extracted from these invectives lead us into thinking that the Grammaticae Institutiones text that we are currently working with was published later than 1563, date shown on the front cover.My essay analyses the critique made by the 16th century humanist Rui López de Segura in his gramatical work Grammaticae Institutiones on some of El Brocense´s grammatical ideas such as noun gender or case morphology and so on. In a closer reading of the Brocense´s works, however, that were available to Rui Lopez it can be ascertained that most of his critique has no scientific ground and reveals to a certain degree some personal bias. Besides, some specific data extracted from these invectives lead us into thinking that the Grammaticae Institutiones text that we are currently working with was published later than 1563, date shown on the front cover