1,171 research outputs found

    A Practical Example for Model-Driven Web Requirements

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    The number of approaches for Web environments has grown very fast in the last years: HDM, OOHDM, and WSDM were among the first, and now a large number can be found in the literature. With the definition of MDA (Model- Driven Architecture) and the acceptance of MDE (Model-Driven Engineering) techniques in this environment, some groups are working in the use of metamodels and transformations to make their approaches more powerful. UWE (UMLBased Web Engineering) or OOWS (Object-Oriented Web Solutions) are only some examples. However, there are few real experiences with Web Engineering in the enterprise environment, and very few real applications of metamodels and MDE techniques. In this chapter the practical experience of a Web Engineering approach, NDT, in a big project developed in Andalusia is presented. Besides, it shows the usability of metamodels in real environments

    A methodological proposal and tool support for the HL7 standards compliance in the development of health information systems

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    Health information systems are increasingly complex, and their development is presented as a challenge for software development companies offering quality, maintainable and interoperable products. HL7 (Health level 7) International, an international non-profit organization, defines and maintains standards related to health information systems. However, the modelling languages proposed by HL7 are far removed from standard languages and widely known by software engineers. In these lines, NDT is a software development methodology that has a support tool called NDT-Suite and is based, on the one hand, on the paradigm of model-driven engineering and, on the other hand, in UML that is a widely recognized standard language. This paper proposes an extension of the NDT methodology called MoDHE (Model Driven Health Engineering) to offer software engineers a methodology capable of modelling health information systems conforming to HL7 using UML domain models

    A Practical Environment to Apply Model-Driven Web Engineering

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    The application of a model-driven paradigm in the development of Web Systems has yielded very good research results. Several research groups are defining metamodels, transformations, and tools which offer a suitable environment, known as model-driven Web engineering (MDWE). However, there are very few practical experiences in real Web system developments using real development teams. This chapter presents a practical environment of MDWE based on the use of NDT (navigational development techniques) and Java Web systems, and it provides a practical evaluation of its application within a real project: specialized Diraya.Ministerio de Educación y Ciencia TIN2007-67843-C06-03Ministerio de Educación y Ciencia TIN2007-30391-

    Phylogenetic Patterns in Montane Troglodytes Wrens

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    Phylogenetic studies based on mitochondrial DNA sequences of 10 species of wrens in Troglodytes and related genera suggest a new hypothesis of relationships for the group. The Winter Wren (T. troglodytes) and the anomalous Timberline Wren (Thryorchilus browni) are distantly related to the remainder of Troglodytes. The latter group divides into a tropical montane group and a northern/lowland group that includes the northernmost two montane taxa (T. rufociliatus, T. brunneicollis). Erection of the genus Nannus for the Winter Wren is proposed. Song evolution in the complex has involved either convergent derivation or retention of primitive song types in distant lineages

    Optimal Fiscal Policy in the Uzawa-Lucas Model with CES Production

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    [Abstract]: This paper devises an endogenous growth model with human capital in the UzawaLucas framework in which the average human capital has a positive external effect on the goods sector. Unlike previous works, this paper assumes that output is produced with a CES technology and analyzes the existence, uniqueness, and stability of equilibrium. Also, a fiscal policy is devised that is capable of providing the required incentives to optimize the competitive equilibrium. In order to correct the market failure caused by the externality, the authors introduce a subsidy to human capital and analyze how it can be financed in an optimal way. Some simulation results are presented.(JEL O41, E62

    Interaction of landscape varibles on the potential geographical distribution of parrots in the Yucatan Peninsula, Mexico

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    La interacción de las variables del paisaje en la distribución geográfica potencial de los loros en la península de Yucatán, México La pérdida, degradación y fragmentación de las zonas boscosas están poniendo en peligro a las poblaciones de loros. En este estudio se determinó la influencia de la fragmentación en relación con la cobertura vegetal, los usos del suelo y la configuración espacial de los fragmentos, sobre los modelos de distribución geográfica potencial de los loros en la península de Yucatán, México. Se utilizó la distribución geográfica potencial de ocho especies de loros, teniendo en cuenta los mapas publicados recientemente y obtenidos con el algoritmo de máxima entropía, y se incorporó el mapa de probabilidad de distribución de cada especie. Se calcularon 71 parámetros y variables que evalúan la fragmentación forestal, la configuración espacial de los fragmentos, la proporción ocupada por vegetación y los usos del suelo en 100 parcelas de aproximadamente 29 km² distribuidas al azar dentro de las zonas de presencia y ausencia predichas para cada especie. Además, se tuvo en cuenta la relación entre las variables ambientales y la probabilidad de distribución de las especies. Se empleó una regresión de mínimos cuadrados parciales para analizar la relación existente entre las variables empleadas y los modelos de distribución potencial. Ninguna de las variables ambientales analizadas determina por sí sola la presencia, la ausencia ni la probabilidad de distribución de los loros en la península. Se observó que para las ocho especies, ya sea debido a la presencia y la ausencia o a la probabilidad de distribución, las variables explicativas más importantes son la interacción entre tres variables, en especial la interacción entre la superficie forestal total, la longitud total de los perímetros de los fragmentos y la cantidad de bosque tropical subperennifolio de altura mediana. La fragmentación del hábitat influye sobre la distribución geográfica potencial de estas especies en combinación con otros factores ambientales asociados a la misma, como son la proporción de las diferentes coberturas vegetales y los usos del suelo que se desarrollan en las áreas deforestadas.La interacción de las variables del paisaje en la distribución geográfica potencial de los loros en la península de Yucatán, México La pérdida, degradación y fragmentación de las zonas boscosas están poniendo en peligro a las poblaciones de loros. En este estudio se determinó la influencia de la fragmentación en relación con la cobertura vegetal, los usos del suelo y la configuración espacial de los fragmentos, sobre los modelos de distribución geográfica potencial de los loros en la península de Yucatán, México. Se utilizó la distribución geográfica potencial de ocho especies de loros, teniendo en cuenta los mapas publicados recientemente y obtenidos con el algoritmo de máxima entropía, y se incorporó el mapa de probabilidad de distribución de cada especie. Se calcularon 71 parámetros y variables que evalúan la fragmentación forestal, la configuración espacial de los fragmentos, la proporción ocupada por vegetación y los usos del suelo en 100 parcelas de aproximadamente 29 km² distribuidas al azar dentro de las zonas de presencia y ausencia predichas para cada especie. Además, se tuvo en cuenta la relación entre las variables ambientales y la probabilidad de distribución de las especies. Se empleó una regresión de mínimos cuadrados parciales para analizar la relación existente entre las variables empleadas y los modelos de distribución potencial. Ninguna de las variables ambientales analizadas determina por sí sola la presencia, la ausencia ni la probabilidad de distribución de los loros en la península. Se observó que para las ocho especies, ya sea debido a la presencia y la ausencia o a la probabilidad de distribución, las variables explicativas más importantes son la interacción entre tres variables, en especial la interacción entre la superficie forestal total, la longitud total de los perímetros de los fragmentos y la cantidad de bosque tropical subperennifolio de altura mediana. La fragmentación del hábitat influye sobre la distribución geográfica potencial de estas especies en combinación con otros factores ambientales asociados a la misma, como son la proporción de las diferentes coberturas vegetales y los usos del suelo que se desarrollan en las áreas deforestadas.The loss, degradation, and fragmentation of forested areas are endangering parrot populations. In this study, we determined the influence of fragmentation in relation to vegetation cover, land use, and spatial configuration of fragments on the potential geographical distribution patterns of parrots in the Yucatan Peninsula, Mexico. We used the potential geographical distribution for eight parrot species, considering the recently published maps obtained with the maximum entropy algorithm, and we incorporated the probability distribution for each species. We calculated 71 metrics/variables that evaluate forest fragmentation, spatial configuration of fragments, the ratio occupied by vegetation, and the land use in 100 plots of approximately 29 km², randomly distributed within the presence and absence areas predicted for each species. We also considered the relationship between environmental variables and the distribution probability of species. We used a partial least squares regression to explore patterns between the variables used and the potential distribution models. None of the environmental variables analyzed alone determined the presence/absence or the probability distribution of parrots in the Peninsula. We found that for the eight species, either due to the presence/absence or the probability distribution, the most important explanatory variables were the interaction among three variables, particularly the interactions among the total forest area, the total edge, and the tropical semi–evergreen medium– height forest. Habitat fragmentation influenced the potential geographical distribution of these species in terms of the characteristics of other environmental factors that are expressed together with the geographical division, such as the different vegetation cover ratio and land uses in deforested areas

    Conjugate heat transfer study of the impact of "thermo-swing" coatings on internal combustion engines heat losses

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    [EN] To comply with the very strict emissions regulation the automotive industry is succeeding in developing ever more efficient engines, and there is scope for more improvements. In this regard, some investigations have suggested that insulating the combustion chamber walls of an internal combustion engine (ICE) yield low thermal losses. Most of the literature available on this topic presents simplified models that do not allow studying in detail the coating impact on engine efficiency. A more precise approach that consists in the combination of Computational Fluid Dynamics (CFD) and Conjugate Heat Transfer (CHT) simulations is used in this paper to predict the heat losses through the combustion chamber walls of a spark ignition (SI) engine. Two configurations are considered for the single cylinder engine: the metallic case and the same engine with coated piston and cylinder head. The insulation material has a low thermal conductivity (k 3.0.co;2-fDai, X. (Hunter), Singh, S., Krishnan, S. R., & Srinivasan, K. K. (2018). Numerical study of combustion characteristics and emissions of a diesel–methane dual-fuel engine for a wide range of injection timings. International Journal of Engine Research, 21(5), 781-793. doi:10.1177/1468087418783637Broatch, A., Olmeda, P., García, A., Salvador-Iborra, J., & Warey, A. (2017). Impact of swirl on in-cylinder heat transfer in a light-duty diesel engine. Energy, 119, 1010-1023. doi:10.1016/j.energy.2016.11.040Andruskiewicz, P., Najt, P., Durrett, R., Biesboer, S., Schaedler, T., & Payri, R. (2017). Analysis of the effects of wall temperature swing on reciprocating internal combustion engine processes. International Journal of Engine Research, 19(4), 461-473. doi:10.1177/1468087417717903Poubeau, A., Vauvy, A., Duffour, F., Zaccardi, J.-M., Paola, G. de, & Abramczuk, M. (2018). Modeling investigation of thermal insulation approaches for low heat rejection Diesel engines using a conjugate heat transfer model. International Journal of Engine Research, 20(1), 92-104. doi:10.1177/1468087418818264Broatch, A., Margot, X., Novella, R., & Gomez-Soriano, J. (2016). Combustion noise analysis of partially premixed combustion concept using gasoline fuel in a 2-stroke engine. Energy, 107, 612-624. doi:10.1016/j.energy.2016.04.045Broatch, A., Margot, X., Novella, R., & Gomez-Soriano, J. (2017). Impact of the injector design on the combustion noise of gasoline partially premixed combustion in a 2-stroke engine. Applied Thermal Engineering, 119, 530-540. doi:10.1016/j.applthermaleng.2017.03.081Yakhot, V., & Orszag, S. A. (1986). Renormalization group analysis of turbulence. I. Basic theory. Journal of Scientific Computing, 1(1), 3-51. doi:10.1007/bf01061452Redlich, O., & Kwong, J. N. S. (1949). On the Thermodynamics of Solutions. V. An Equation of State. Fugacities of Gaseous Solutions. Chemical Reviews, 44(1), 233-244. doi:10.1021/cr60137a013Issa, R. . (1986). Solution of the implicitly discretised fluid flow equations by operator-splitting. Journal of Computational Physics, 62(1), 40-65. doi:10.1016/0021-9991(86)90099-9Torregrosa, A., Olmeda, P., Degraeuwe, B., & Reyes, M. (2006). A concise wall temperature model for DI Diesel engines. Applied Thermal Engineering, 26(11-12), 1320-1327. doi:10.1016/j.applthermaleng.2005.10.021Torregrosa, A. J., Olmeda, P., Martín, J., & Romero, C. (2011). A Tool for Predicting the Thermal Performance of a Diesel Engine. Heat Transfer Engineering, 32(10), 891-904. doi:10.1080/01457632.2011.548639Lu, Y., Zhang, X., Xiang, P., & Dong, D. (2017). Analysis of thermal temperature fields and thermal stress under steady temperature field of diesel engine piston. Applied Thermal Engineering, 113, 796-812. doi:10.1016/j.applthermaleng.2016.11.07

    Sugarcane (Saccharum sp. Hybrid) propagated in headspace renovating systems shows autotrophic characteristics and develops improved anti-oxidative response

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    Previous results have shown that sugarcane plantlets micropropagated in Temporary Immersion Bioreactors (TIB) demonstrated a better morphology and physiological behaviour when compared to plantlets propagated in Gelled Medium (GM). The present work focuses on the onset of oxidative stress symptoms at transfer to ex vitro and during acclimatization. The specific ROS being produced were identified and tissue-located by infiltrating leaves with specific O2 −.and H2O2 staining dyes, respectively NBT and DAB. TIB plantlets showed trichomes stained with NBT and DAB, their density decreasing with time. Stomata were coloured with NBT and DAB in GM and, at the end of acclimatization, plantlets from both systems presented the lowest level of staining of both stomata and trichomes. The response of the anti-oxidative system was also analysed through in vitro and in gel enzyme activities and transcription levels of genes for key response enzymes. At the end of the in vitro phase, GM plantlets showed higher activities of APX and MDHAR, while CAT, GR, GT and DHAR activities increased in TIB. At the end of acclimatization SOD and CAT increased mainly in TIB, while GM induced the increase of APX. The immunobloting of peroxiredoxins showed that Prxs were expressed at higher levels in TIB plantlets, some showing polymerization. The transcription of genes coding for key response enzymes was strongly upregulated in GM plantlets. In conclusion and comparing with GM, TIB produced plantlets closer to autotrophy and with improved mobilization of the anti-oxidative response
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