450 research outputs found

    Systematic evaluation of software product line architectures

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    The architecture of a software product line is one of its most important artifacts as it represents an abstraction of the products that can be generated. It is crucial to evaluate the quality attributes of a product line architecture in order to: increase the productivity of the product line process and the quality of the products; provide a means to understand the potential behavior of the products and, consequently, decrease their time to market; and, improve the handling of the product line variability. The evaluation of product line architecture can serve as a basis to analyze the managerial and economical values of a product line for software managers and architects. Most of the current research on the evaluation of product line architecture does not take into account metrics directly obtained from UML models and their variabilities; the metrics used instead are difficult to be applied in general and to be used for quantitative analysis. This paper presents a Systematic Evaluation Method for UML-based Software Product Line Architecture, the SystEM-PLA. SystEM-PLA differs from current research as it provides stakeholders with a means to: (i) estimate and analyze potential products; (ii) use predefined basic UML-based metrics to compose quality attribute metrics; (iii) perform feasibility and trade-off analysis of a product line architecture with respect to its quality attributes; and, (iv) make the evaluation of product line architecture more flexible. An example using the SEI’s Arcade Game Maker (AGM) product line is presented as a proof of concept, illustrating SystEM-PLA activities. Metrics for complexity and extensibility quality attributes are defined and used to perform a trade-off analysis

    The 12 prophets dataset

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    The "Ajeijadinho 3D" project is an initiative supported by the University of S\~ao Paulo (Museum of Science and Dean of Culture and Extension), which involves the 3D digitization of art works of Brazilian sculptor Antonio Francisco Lisboa, better known as Aleijadinho. The project made use of advanced acquisition and processing of 3D meshes for preservation and dissemination of the cultural heritage. The dissemination occurs through a Web portal, so that the population has the opportunity to meet the art works in detail using 3D visualization and interaction. The portal address is http://www.aleijadinho3d.icmc.usp.br. The 3D acquisitions were conducted over a week at the end of July 2013 in the cities of Ouro Preto, MG, Brazil and Congonhas do Campo, MG, Brazil. The scanning was done with a special equipment supplied by company Leica Geosystems, which allowed the work to take place at distances between 10 and 30 meters, defining a non-invasive procedure, simplified logistics, and without the need for preparation or isolation of the sites. In Ouro Preto, we digitized the churches of Francisco of Assis, Our Lady of Carmo, and Our Lady of Mercy; in Congonhas do Campo we scanned the entire Sanctuary of Bom Jesus de Matosinhos and his 12 prophets. Once scanned, the art works went through a long process of preparation, which required careful handling of meshes done by experts from the University of S\~ao Paulo in partnership with company Imprimate.Comment: Full dataset online at http://aleijadinho3d.icmc.usp.br/data.htm

    Quantile Regression Approaches for Auctions

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    PhDThe goal of this thesis is to propose a new quantile regression approach to identify and estimate the quantiles of the private value conditional distribution in ascending and rst price auctions under the Independent Private Value (IPV) paradigm. The quantile regression framework provides a exible and convenient parametrization of the private value distribution, which is not a ected by the curse of dimensionality. The rst Chapter of the thesis introduces a quantile regression methodology for ascending auctions. The Chapter focuses on revenue analysis, optimal reservation price and its associated screening level. An empirical application for the USFS timber auctions suggests an optimal reservation price policy with a probability of selling the good as low as 58% for some auctions with two bidders. The second Chapter tries to address this issue by considering a risk averse seller with a CRRA utility function. A numerical exercise based on the USFS timber auctions shows that increasing the CRRA of the sellers is su cient to give more reasonable policy recommendations and a higher probability of selling the auctioned timber lot. The third Chapter develops a quantile regression methodology for rst-price auction. The estimation method combines local polynomial, quantile regression and additive sieve methods. It is shown in addition that the new quantile regression methodology is not subject to boundary issues. The choice of smoothing parameters is also discussed.School of Economics and Finance at Queen Mary, University of Lon

    Taxa de acúmulo de matéria seca e biomassa aérea de uma pastagem de capim braquiária.

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    Esse estudo faz parte do projeto de pesquisa denominado "Variabilidade espacial dos índices de qualidade do solo para sistemas agropecuários Qualisolo". O objetivo do estudo é a obtenção da taxa de acúmulo de matéria seca e a biomassa aérea de uma pastagem de capim braquiária usualmente encontrada em propriedades rurais brasileiras de criação de gado de corte. No presente trabalho fez-se também, para efeito de comparação, a estimativa de taxa de acúmulo de matéria seca através de modelos empíricos da literatura que utilizam alguns elementos climáticos. O estudo foi realizado na fazenda experimental do Instituto de Zootecnia, em Nova Odessa (SP), de novembro de 2010 a junho de 2011. A pastagem foi manejada sob pastejo contínuo e taxa de lotação variável. A taxa média de acúmulo da forragem no período foi de 50,5 kg MS. ha?¹.dia?¹ e o acúmulo total de matéria seca em 213 dias foi 10.754,4 kg MS. ha?¹. A análise geoestatística da biomassa obtida em 50 pontos de amostragem revelou dependência espacial somente para a biomassa média dos meses agrupados de verão e outono.bitstream/item/58506/1/001-12.pd
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