3,398 research outputs found
Ecological Inference with Entropy Econometrics: using the Mexican Census as a benchmark
Most regional empirical analyses are limited by the lack of data. Researchers have to use information that is structured in administrative or political regions which are not always economically meaningful. The non-availability of geographically disaggregated information prevents to obtain empirical evidence in order to answer some relevant questions in the field of urban and regional economics. The objective of this paper is to suggest an estimation procedure, based on entropy econometrics, which allows for inferring disaggregated information on local income from more aggregated data. In addition to a description of the main characteristics of the proposed technique, the paper illustrates how the procedure works taking as an empirical application the estimation of income for different classes of Mexican municipalities. It would be desirable to apply the suggested technique to a study case where some observable data are available and confront the estimates with the actual observations. For this purpose, we have taken the information contained in the Mexican census as a benchmark for our estimation technique. Assuming that the only available data are the income aggregates per type of municipality and State, we make an exercise of ecological inference and disaggregate these margins to recover individual (local) data.
Distinguished self-adjoint extensions of Dirac operators via Hardy-Dirac inequalities
We prove some Hardy-Dirac inequalities with two different weights including
measure valued and Coulombic ones. Those inequalities are used to construct
distinguished self-adjoint extensions of Dirac operators for a class of
diagonal potentials related to the weights in the above mentioned inequalities.Comment: 16 page
The tadpole of Pseudis minuta (Anura: Pseudidae), an apparent case of heterochrony
The external morphology, oral disc, and coloration pattern of the larva of Pseudis minuta are described. Tadpoles are mostly bottom dwellers that have a small, terminal oral disc with a labial tooth row formula 1(1-1)/(1-1)2. Internal oral anatomy is characterized using scanning electron microscopy, representing the only description available for the family Pseudidae. The coloration pattern of P. minuta tadpoles is compared with that of other pseudids. Pseudis minuta larvae do not exhibit the ontogenetic coloration change reported for P. paradoxa. Considering larval coloration, larval size, and reports of adult size, acceleration or hypermorphosis are suggested as possible heterochronic mechanisms involved in the evolution of Pseudis
Estudio térmico experimental y alternativas de usos de dos modelos de cocinas solares en zonas áridas
Este trabajo tiene como objetivo presentar el estudio experimental del comportamiento térmico de dos modelos de cocinas solares, el concentrador solar parabólico lineal y el horno solar inclinado tipo caja, junto a alternativas de aplicación en forma combinada. Está dirigido a la provisión de agua libre de contaminación, preparación y cocción de alimentos, para la arquitectura regional de zonas áridas alejadas o aisladas. La metodologÃa de investigación considera, procesos de transferencia de calor, estudios de comportamiento térmico solar a nivel experimental y de posibilidades de resolución de necesidades alimenticias. Los resultados demuestran convenientes tiempos de cocción, facilitando su utilización, según costumbres y localizaciones, en refugios y viviendas rurales. Las conclusiones obtenidas sobre los aspectos técnicos, ambientales y socioeconómicos vinculados a los sistemas solares analizados, permiten afirmar que sus aplicaciones en forma conjunta, contribuyen a mejorar a diario servicios domésticos e incrementar funciones y prestaciones.Fil: Buigues Nollens, Arturo. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Mecanica Aplicada; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Fariello, Marcelo O.. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Mecanica Aplicada; ArgentinaFil: Rojos, Esteban O.. Universidad Nacional de San Juan. Facultad de IngenierÃa. Instituto de Mecanica Aplicada; Argentin
The Migration of Skilled Women: A Case Study in the United
Abstract: This article concerns the case of Spanish women with higher education and their migration to the United Kingdom between 2009 and 2012. Based on an analysis of available statistical data and qualitative research (participant observation and 12 in-depth interviews), we explore the work and living conditions of migrant women. The results indicate: 1) that the number of migrants during the crisis is lower than previously thought and that, according to the available data, it cannot be classed as skilled migration; 2) similarly, that the socio-demographic profile is heterogeneous and, 3) that there are diverse economic conditions upon entry, often resulting in situations of vulnerability and social exclusion
Keeping Feet Dry: Rotterdam’s Experience in Flood Risk and Resilience Building
Rotterdam City in the South of Holland is one of the most vibrant cities you will find in the Netherlands. The city has gone through a transformation from the time it was bombed in the 1940s up to the time that a part of the city was flooded in 1953. Through extensive rebuilding and the Delta Plan project, the city has been well protected against any flooding disaster that may come. However, how resilient really is Rotterdam? Through in-depth interviews of key stakeholders in the City of Rotterdam, the study investigates the collective engagement in the city and how this has helped shape Rotterdam’s position in urban resilience. The study used the Collective Engagement Urban Resilience Framework as a framework to understand how disaster prone cities transform itself to become disaster resilient
PPROC, an ontology for transparency in'public procurement
Public procurement or tendering refers to the process followed by public authorities for the procurement of goods and services. In most developed countries, the law requires public authorities to provide online information to ensure competitive tendering as far as possible, for which the adequate announcement of tenders is an essential requirement. In addition, transparency laws being proposed in such countries are making the monitoring of public contracts by citizens a fundamental right. This paper describes the PPROC ontology, which has been developed to give support to both processes, publication and accountability, by semantically describing public procurement processes and contracts. The PPROC ontology is extensive, since it covers not only the usual data about the tender, its objectives, deadlines and awardees, but also details of the whole process, from the initial contract publication to its termination. This makes it possible to use the ontology for both open data publication purposes and for the overall management of the public contract procurement process
Precession of neutrino-cooled accretion disks in gamma-ray burst engines
Aims. We study the precession of accretion disks in the context of gamma-ray burst inner engines.
Methods. With an accretion disk model that allows for neutrino cooling, we evaluate the possible periods of disk precession and nutation due to the Lense-Thirring effect.
Results. Assuming jet ejection perpendicular to the disk midplane and a typical intrinsic time dependence for the burst, we find possible gamma-ray light curves with a temporal microstructure similar to what is observed in some subsamples.
Conclusions. We conclude that the precession and nutation of a neutrino-cooled accretion disk in the burst engine might be responsible for some events, especially those with a slow rise and a fast decay.Facultad de Ciencias Astronómicas y GeofÃsicasInstituto Argentino de RadioastronomÃ
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