18,084 research outputs found

    NSV 13983: A New Dwarf Nova in the Period Gap

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    Aims. NSV 13983 is catalogued as a dwarf nova based on a reported outburst from 2005. The system has not yet been studied spectroscopically. We attempt to confirm its nature as a dwarf nova and determine its orbital period. Methods. We derive the orbital period by using time-resolved spectroscopic data to measure radial velocities. Results. The average spectrum shows evidence that the system is a dwarf nova in quiescence. The radial velocity curves derived from measurements of the spectral lines H\alpha and H\beta, show a clear modulation with a period of 2.76 h. This places NSV 13983 below the upper edge of the gap in the period distribution of cataclysmic variables, implying that it is the 14th dwarf nova in the gap.Comment: 3 pages, 4 figures, 1 tables, accepted by A&

    Text-based Semantic Annotation Service for Multimedia Content in the Esperonto project

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    Within the Esperonto project, an integration of NLP, ontologies and other knowledge bases, is being performed with the goal to implement a semantic annotation service that upgrades the actual Web towards the emerging Semantic Web. Research is being currently conducted on how to apply the Esperonto semantic annotation service to text material associated with still images in web pages. In doing so, the project will allow for semantic querying of still images in the web, but also (automatically) create a large set of text-based semantic annotations of still images, which can be used by the Multimedia community in order to support the task of content indexing of image material, possibly combining the Esperonto type of annotations with the annotations resulting from image analysis

    The effects of lengthening the school day on female labor supply: Evidence from a quasi-experiment in Chile

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    In 1996, the Chilean government approved the extension of the school day, increasing the amount of time that students spend at school by 30%. Using data from the Chilean socio- economic household survey and administrative data from the Ministry of Education for 1990- 2006, we exploit the quasi-experimental nature of the reform’s implementation by time and region in order to identify the causal impact of the program on labor participation, employment and hours worked for women between 20 and 65 years old. The identification strategy relies on a fixed effect model of repeated cross-section. The results show a positive and significant effect on labor participation and female employment in all age groups and a negative and statistically significant effect on the number of hours worked. The main conclusion of this study is that the implicit childcare subsidy induced by the program had a positive and significant impact on the labor supply of women in Chile.Female labor supply; childcare; fertility; labor supply; Chile.
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