911 research outputs found

    Web browsing automation for applications quality control

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    Context: Quality control comprises the set of activities aimed to evaluate that software meets its specification and delivers the functionality expected by the consumers. These activities are often removed in the development process and, as a result, the final software product usually lacks quality. Objective: We propose a set of techniques to automate the quality control for web applications from the client-side, guiding the process by functional and nonfunctional requirements (performance, security, compatibility, usability and accessibility). Method: The first step to achieve automation is to define the structure of the web navigation. Existing software artifacts in the phase of analysis and design are reused. Then, the independent paths of navigation are found, and each path is traversed automatically using real browsers while different kinds of assessments are carried out. Results: The processes and methods proposed in this paper have been implemented by means of a reference architecture and open source tools. A laboratory experiment and an industrial case study have been performed in order to validate the proposal. Conclusion: The definition of navigation paths is a rich approach to model web applications. Grey-box (black-box and white-box) methods have been proved to be very valuable for web assessment. The Chinese Postman Problem (CPP) is an optimal way to find the independent paths in a web navigation modeled as a directed graph

    Modelos de optimización de localización de bases de bicicletas públicas: un enfoque basado en Sistemas de Información

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    Un número creciente de ciudades están implementando programas de bicicletas públicas para incrementar el uso de la bicicleta. Uno de los factores clave en el éxito de estos programas es la localización de las bases en relación a la demanda potencial (población, actividades, estaciones de transporte público). En este trabajo se propone una metodología apoyada en un Sistema de Información Geográfica (GIS) para optimizar la localización de bases de bicicletas en función de la distribución espacial de la demanda potencial de viajes. Esta metodología utiliza modelos de localización óptima de servicios. Aquí se comparan los resultados obtenidos mediante dos de las soluciones más usadas, mínima impedancia y máxima cobertura, concluyendo que el segundo es más útil para el objetivo del trabajo. En ambos casos se observan rendimientos decrecientes: con el aumento del número de bases las mejoras en cantidad de población cubierta y accesibilidad son cada vez menores. A la vez, estos modelos permiten también determinar la capacidad necesaria en las bases y conocer las características de su demanda según la cual se puede clasificar a las bases diferenciando entre generadoras y atractoras de viajes. Dado que también la estructura espacial de la red propuesta juega un papel importante en el uso de las bases, adicionalmente se realiza un análisis de accesibilidad para calcular el volumen de actividad que al que tiene acceso cada una de las bases. Este análisis permite descartar bases relativamente aisladas y que por lo tanto tendrían poca utilidad para sus potenciales usuarios

    Two-Dimensional Line Strength Maps in Three Well-studied Early-Type Galaxies

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    Integral field spectroscopy has been obtained for the nuclear regions of 3 large, well-studied, early-type galaxies. From these spectra we have obtained line strength maps for about 20 absorption lines, mostly belonging to the Lick system. An extensive comparison with multi-lenslet spectroscopy shows that accurate kinematic maps can be obtained, and also reproducible line strength maps. Comparison with long-slit spectroscopy also produces good agreement. We show that Mg is enhanced with respect to Fe in the inner disk of one of the three galaxies studied, the Sombrero. [Mg/Fe] there is larger than in the rest of the bulge. The large values of Mg/Fe in the central disk are consistent with the centres of other early-type galaxies, and not with large disks, like the disk of our Galaxy, where [Mg/Fe] is approximately 0. We confirm with this observation a recent result of Worthey (1998) that Mg/Fe is determined by the central kinetic energy, or escape velocity, of the stars, only, and not by the formation time scale of the stars. A stellar population analysis using the models of Vazdekis et al. (1996) shows that our observed H gamma agrees well with what is predicted based on the other lines. Using the line strength of the Ca II IR triplet as an indicator of the abundance of Ca, we find that Ca follows Fe, and not Mg, in these galaxies. This is peculiar, given the fact that Ca is an alpha-element. Finally, by combining the results of this paper with those of Vazdekis et al. (1997) we find that the line strength gradients in the three galaxies are primarily caused by variations in metallicity.Comment: 23 pages, Latex, includes mn.sty, accepted for publication in Monthly Notices of the Royal Astronomical Societ

    Taxonomic differences between Pinus sylvestris and P. uncinata revealed in the stomata and cuticle characters for use in the study of fossil material

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    Taxonomic differences in the needle epidermis characteristics of Pinus sylvestris L. and Pinus uncinata Ramond ex DC. from two Iberian populations were sought; such information could help identify these species when pollen analysis and the inspection of wood anatomy fails. The features of the cuticle are commonly well preserved in the fossil record. Although the epidermal patterns of the examined taxa were similar, qualitative differences were seen in the subsidiary and guard cells. P. sylvestris showed small subsidiary cells homogenously arranged around the opening of the epistomatal chamber, while P. uncinata showed small, lateral subsidiary cells and non-differentiated subsidiary cells in the polar position. The aperture of the epistomatic chamber of P. uncinata was also larger in diameter (15.1 ± 1.8 µm P. sylvestris; 21.1 ± 2.8 µm P. uncinata). Principal components analysis and discriminant analysis was performed on the features of the guard cells characterising the size and shape of the cuticular thickenings — all the variables analysed can be measured in disperse stomata in microscope preparations for pollen analysis. Significant differences were found in the upper woody lamellae width and the coefficient associated with the shape of the medial lamellae borders (discriminant analysis weighting 0.739 and 0.826 respectively). Other significant parameters included the coefficient associated with the relative size of the medial lamellae border width of the guard cells with respect to the distance between the external limits of the medial lamellae borders, and the length of the upper woody lamella. Different light regimens appeared not to significantly affect the variability of the studied features

    SELECTION FOR YIELD AT TWO FERTILIZER LEVELS IN SMALL-SEEDED COMMON BEAN

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    Selection for seed yield (visual in the F2, visual and pl:t yield from the F3 to F5, and yield tests in F6) was carried out in two crosses of common bean (Phaseolus vulgaris L.) in high and low soil fertility environments at ClAT-Quilichao, Colombia. Parents were small-seeded and tolerant to low soil phosphorus, possessed indeterminate bush growth habit, and belonged to lowland tropical gene pools of Middle America. The mean yield of selected lines from low (LFS) and high (HFS) soil fertility environments was significantly higher than the mean of the parents in both crosses when tested in high fertility (HF) but not in low fertility (LF). The highest yielding LFS and HFS lines from A 286 x (G 5059 x A 80) and the LFS line from A 286 x ICA Pijao outyielded the best check cultivar, Carioca, in HF. No line yielded significantly more than A 286, the best parent used in both crosses. The mean effect of fertilizer levels on selection for seed yield was nonsignificant. Lines selected under two environments showed similar but average response and high stability of performance under variable environments. Low soil fertility accelerated maturity and reduced 100-seed weight and seed yield\u2
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