Propuesta de un modelo de negocio de iluminación para el uso eficiente y sostenible de la energía

La iluminación eficiente consiste en brindar luz a un espacio determinado utilizando recursos que consuman poca energía, produzcan confort para quien las utiliza y reduzcan el costo ambiental de producirlas. Este tipo de iluminación pretende generar valor agregado tanto al usuario como al inversionista que la posee, amortizando su inversión a través del ahorro generado al utilizar nuevas tecnologías y produciendo beneficios a través del tiempo debido a su equilibrio con el medio ambiente y vida útil extendida. La idea del presente estudio es brindar un modelo de iluminación eficiente que incluya los parámetros básicos que necesite un sistema de iluminación para ser considerado de valor agregado y amigable con el medio ambiente demostrando sus ventajas y desventajas en el momento de efectuar la selección a partir de unos criterios que incluyen aspectos económicos, técnicos y ambientales.

Búsqueda de selección en el polimorfismo 677C>T (c.665C>T) del gen de la metilentetrahidrofolato reductasa (MTHFR) en una población Colombiana

Se realizó un estudio genético – poblacional en dos grupos etarios de población colombiana con la finalidad de evaluar las diferencias genéticas relacionadas con el polimorfismo MTHFR 677CT en busca de eventos genéticos que soporten la persistencia de este polimorfismo en la especie humana debido que este ha sido asociado con múltiples enfermedades. De esta manera se genotipificaron los individuos, se analizaron los genotipos, frecuencias alélicas y se realizaron diferentes pruebas genéticas-poblacionales. Contrario a lo observado en poblaciones Colombianas revisadas se identificó la ausencia del Equilibrio Hardy-Weinberg en el grupo de los niños y estructuras poblacionales entre los adultos lo que sugiere diferentes historias demográficas y culturales entre estos dos grupos poblacionales al tiempo, lo que soporta la hipótesis de un evento de selección sobre el polimorfismo en nuestra población. De igual manera nuestros datos fueron analizados junto con estudios previos a nivel nacional y mundial lo cual sustenta que el posible evento selectivo es debido a que el aporte de ácido fólico se ha incrementado durante las últimas dos décadas como consecuencia de las campañas de fortificación de las harinas y suplementación a las embarazadas con ácido fólico, por lo tanto aquí se propone un modelo de selección que se ajusta a los datos encontrados en este trabajo se establece una relación entre los patrones nutricionales de la especie humana a través de la historia que explica las diferencias en frecuencias de este polimorfismo a nivel espacial y temporal.  

Análisis de los componentes de la candena de suministro y su relación con el desempeño organizacional en el sector prendas de vestir

Esta propuesta de investigación pretende aportar al proyecto de investigación “La administración de la cadena de suministro y su relación con el desempeño superior de la organización” a la elaboración de la primera etapa que consiste en la revisión de literatura para la elaboración y revisión del marco teórico de dicha investigación. Este proyecto se centra en el programa de estrategia y empresa en donde se realizará una investigación descriptiva acerca de la administración de la cadena de suministros, con el fin de estudiar la adopción y viabilidad de diferentes estrategias en el interior de las organizaciones, que puedan impactar en su desempeño y por lo tanto, en la competitividad y perdurabilidad de las empresas del sector de prendas de vestir en Colombia.

The Role of Collateral in Entrepreneurial Finance

Previous research has suggested collateral has the role of sorting entrepreneurs either by observed risk or by private information. In order to test these roles, this paper develops a model which incorporates a signalling process (sorting by observed risk) into the design of an incentivecompatible menu of loan contracts which works as a self-selection mechanism (sorting by private information). It then tests this Sorting by Signalling and Self-Selection Model, using the 1998 US Survey of Small Business Finances. It reports for the first time that: high type entrepreneurs are more likely to pledge collateral and pay a lower interest rate; and entrepreneurs who transfer good signals enjoy better contracts than those transferring bad signals. These findings suggest that the Sorting by Signalling and Self-Selection Model sheds more light on entrepreneurial debt finance than either the sorting-by-observed-risk or the sorting-by-private information paradigms on their own.

Inferential Implications of Over-Parametrization: A Case Study in Incomplete Categorical Data

P>In the context of either Bayesian or classical sensitivity analyses of over-parametrized models for incomplete categorical data, it is well known that prior-dependence on posterior inferences of nonidentifiable parameters or that too parsimonious over-parametrized models may lead to erroneous conclusions. Nevertheless, some authors either pay no attention to which parameters are nonidentifiable or do not appropriately account for possible prior-dependence. We review the literature on this topic and consider simple examples to emphasize that in both inferential frameworks, the subjective components can influence results in nontrivial ways, irrespectively of the sample size. Specifically, we show that prior distributions commonly regarded as slightly informative or noninformative may actually be too informative for nonidentifiable parameters, and that the choice of over-parametrized models may drastically impact the results, suggesting that a careful examination of their effects should be considered before drawing conclusions.Resume Que ce soit dans un cadre Bayesien ou classique, il est bien connu que la surparametrisation, dans les modeles pour donnees categorielles incompletes, peut conduire a des conclusions erronees. Cependant, certains auteurs persistent a negliger les problemes lies a la presence de parametres non identifies. Nous passons en revue la litterature dans ce domaine, et considerons quelques exemples surparametres simples dans lesquels les elements subjectifs influencent de facon non negligeable les resultats, independamment de la taille des echantillons. Plus precisement, nous montrons comment des a priori consideres comme peu ou non-informatifs peuvent se reveler extremement informatifs en ce qui concerne les parametres non identifies, et que le recours a des modeles surparametres peut avoir sur les conclusions finales un impact considerable. Ceci suggere un examen tres attentif de l`impact potentiel des a priori.

Parcerias público-privadas na presença de seleção adversa: uma análise numérica

Esta dissertação propõe-se a analisar a otimalidade de parcerias público-privadas (PPP) em um ambiente de seleção adversa. Mais especi calmente, analiso se as tarefas de construir e operar uma infraestrutura para serviços públicos deve ser realizada por um consórcio ou se devem ser realizadas por fi rmas contratadas separadamente. Para tal, diferentemente da literatura existente para o problema, focadas nos problemas de contratos incompletos e moral hazard, construo um modelo de seleção adversa multidimensional, onde as firrmas possuem informação privada e podem exercer um esforço não observável em cada atividade, com a existência de externalidade entre as tarefas, em uma extensão do modelo de La¤ont e Tirole (1986). Após defi nir algumas condições sob as quais PPP domina os meios usuais de contratação, utilizo de uma análise numérica para melhor compreender a solução do modelo, que se mostra altamente dependente da correlação entre os parâmetros de informação privada das firmas.

Foreign funding to an emerging market: the Monetary Premium Theory and the Brazilian Case, 1991 - 1998

We develop a framework to explain the private capital flows between the rest of the world and an emerging economy. The model, based on the monetary premium theory, relates an endogenous supply of foreign capitals to an endogenous differential of interest rates; its estimation uses the econometric techniques initiated by Heckman. Four questions regarding the capital flows phenomenon are explored, including the statistical process that governs the events of default and the impact of the probability of default on the interest rate differential. Using the methodology, we analyse the dynamics of foreign capital movements in Brazil during the 1991- 1998 period.

Forecasting Brazilian inflation by its aggregate and disaggregated data: a test of predictive power by forecast horizon

This work aims to compare the forecast efficiency of different types of methodologies applied to Brazilian Consumer inflation (IPCA). We will compare forecasting models using disaggregated and aggregated data over twelve months ahead. The disaggregated models were estimated by SARIMA and will have different levels of disaggregation. Aggregated models will be estimated by time series techniques such as SARIMA, state-space structural models and Markov-switching. The forecasting accuracy comparison will be made by the selection model procedure known as Model Confidence Set and by Diebold-Mariano procedure. We were able to find evidence of forecast accuracy gains in models using more disaggregated data

On the effects of non-tariff measures on Brazilian exports

This article proposes an alternative methodology for estimating the effects of non-tariff measures on trade flows, based on the recent literature on gravity models. A two-stage Heckman selection model is applied to the case of Brazilian exports, where the second stage gravity equation is theoretically grounded on the seminal Melitz model of heterogeneous firms. This extended gravity equation highlights the role played by zero trade flows as well as firm heterogeneity in explaining bilateral trade among countries, two factors usually omitted in traditional gravity specifications found in previous literature. Last, it also proposes a economic rationale for the effects of NTM on trade flows, helping to shed some light on its main operating channels under a rather simple Cournot’s duopolistic competition framework.

Supremo interesse: protagonismo político-regulatório e a evolução institucional do processo de seleção dos ministros do STF

Partindo da constatação de que o Brasil acompanha hoje um fenômeno global de protagonismo das cortes supremas nas sociedades complexas contemporâneas, notadamente na criação de políticas-públicas e regulação, o estudo procura mapear a evolução – e progressiva democratização – de uma estrutura de freios e contrapesos prevista na Constituição da República Federativa do Brasil de 1988 (“Constituição”), qual seja, o processo de seleção dos ministros do Supremo Tribunal Federal. Ao longo do texto é analisada a arquitetura institucional e constitucional do processo de indicação e aprovação de novos ministros, bem como exemplificadas mudanças no perfil dos atores políticos, no plexo de competências das instituições envolvidas e no contexto social, político, econômico e cultural que forçaram a transformação prática do modelo de seleção institucional, sem alteração, no entanto, da formatação originalmente prevista desde o Século XIX. Mapeando a origem e evolução da fórmula constitucional de colaboração entre o Poder Executivo e o Poder Legislativo para a escolha dos membros da cúpula do Poder Judiciário, o estudo identifica a origem do modelo brasileiro na inspiração da experiência norte-americana, descrevendo esta e os paralelos possíveis com aquele. A partir do marco central da Constituição, o trabalho procura demonstrar uma progressiva mobilização de atores políticos e sociais em relação ao processo de escolha, notadamente em relação ao momento em que os indicados para o Supremo Tribunal Federal são sabatinados pela Comissão de Constituição, Justiça e Cidadania do Senado Federal. Finalmente, são analisadas concretamente as sabatinas e algumas das suas principais discussões, buscando extrair lições que sirvam de norte colaborativo para a evolução da forma de seleção dos ministros do Supremo Tribunal Federal, inclusive como instrumento de controle prévio de seus membros, futuros elaboradores de políticas-públicas.

On the effects of non tariff measures on Brazilian exports

This article proposes an alternative methodology for estimating the effects of non-tariff measures on trade flows, based on the recent literature on gravity models. A two-stage Heckman selection model is applied to the case of Brazilian exports, where the second stage gravity equation is theoretically grounded on the seminal Melitz model of heterogeneous firms. This extended gravity equation highlights the role played by zero trade flows as well as firm heterogeneity in explaining bilateral trade among countries, two factors usually omitted in traditional gravity specifications found in previous literature. Last, it also proposes a economic rationale for the effects of NTM on trade flows, helping to shed some light on its main operating channels under a rather simple Cournot’s duopolistic competition framework

Análise aerodinâmica de perfis de asa para aeronaves experimentais tipo jn-1

The great importance in selecting the profile of an aircraft wing concerns the fact that its relevance in the performance thereof; influencing this displacement costs (fuel consumption, flight level, for example), the conditions of flight safety (response in critical condition) of the plane. The aim of this study was to examine the aerodynamic parameters that affect some types of wing profile, based on wind tunnel testing, to determine the aerodynamic efficiency of each one of them. We compared three types of planforms, chosen from considerations about the characteristics of the aircraft model. One of them has a common setup, and very common in laboratory classes to be a sort of standard aerodynamic, it is a symmetrical profile. The second profile shows a conFiguration of the concave-convex type, the third is also a concave-convex profile, but with different implementation of the second, and finally, the fourth airfoil profile has a plano-convex. Thus, three different categories are covered in profile, showing the main points of relevance to their employment. To perform the experiment used a wind tunnel-type open circuit, where we analyzed the pressure distribution across the surface of each profile. Possession of the drag polar of each wing profile can be, from the theoretical basis of this work, the aerodynamic characteristics relate to the expected performance of the experimental aircraft, thus creating a selection model with guaranteed performance aerodynamics. It is believed that the philosophy used in this dissertation research validates the results, resulting in an experimental alternative for reliable implementation of aerodynamic testing in models of planforms

Calling behavior and parasite intensity in Treefrogs, Hypsiboas prasinus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identificação e quantificação das proteínas miofibrilares, isoformas da cadeia pesada de miosina (MyHC) e o amaciamento da carne de bovinos Nelore (Bos indicus)

Pós-graduação em Genética e Melhoramento Animal - FCAV

On the impact of disproportional samples in credit scoring models: An application to a Brazilian bank data

Statistical methods have been widely employed to assess the capabilities of credit scoring classification models in order to reduce the risk of wrong decisions when granting credit facilities to clients. The predictive quality of a classification model can be evaluated based on measures such as sensitivity, specificity, predictive values, accuracy, correlation coefficients and information theoretical measures, such as relative entropy and mutual information. In this paper we analyze the performance of a naive logistic regression model (Hosmer & Lemeshow, 1989) and a logistic regression with state-dependent sample selection model (Cramer, 2004) applied to simulated data. Also, as a case study, the methodology is illustrated on a data set extracted from a Brazilian bank portfolio. Our simulation results so far revealed that there is no statistically significant difference in terms of predictive capacity between the naive logistic regression models and the logistic regression with state-dependent sample selection models. However, there is strong difference between the distributions of the estimated default probabilities from these two statistical modeling techniques, with the naive logistic regression models always underestimating such probabilities, particularly in the presence of balanced samples. (C) 2012 Elsevier Ltd. All rights reserved.