2,610 research outputs found

    Quality of Web Mashups: A Systematic Mapping Study

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    The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-04244-2_8Web mashups are a new generation of applications based on the composition of ready-to-use, heterogeneous components. They are gaining momentum thanks to their lightweight composition approach, which represents a new opportunity for companies to leverage on past investments in SOA, Web services, and public APIs. Although several studies are emerging in order to address mashup development, no systematic mapping studies have been reported on how quality issues are being addressed. This paper reports a systematic mapping study on which and how the quality of Web mashups has been addressed and how the product quality-aware approaches have been defined and validated. The aim of this study is to provide a background in which to appropriately develop future research activities. A total of 38 research papers have been included from an initial set of 187 papers. Our results provided some findings regarding how the most relevant product quality characteristics have been addressed in different artifacts and stages of the development process. They have also been useful to detect some research gaps, such as the need of more controlled experiments and more quality-aware mashup development proposals for other characteristics which being important for the Web domain have been neglected such as Usability and ReliabilityThis work is funded by the MULTIPLE project (TIN2009-13838), the Senescyt program (scholarships 2011), and the Erasmus Mundus Programme of the European Commission under the Transatlantic Partnership for Excellence in Engineering - TEE Project.Cedillo Orellana, IP.; Fernández Martínez, A.; Insfrán Pelozo, CE.; Abrahao Gonzales, SM. (2013). Quality of Web Mashups: A Systematic Mapping Study. En Current Trends in Web Engineering. Springer. 66-78. https://doi.org/10.1007/978-3-319-04244-2_8S6678Alkhalifa, E.: The Future of Enterprise Mashups. Business Insights. E-Strategies for Resource Management Systems (2009)Beemer, B., Gregg, D.: Mashups: A Literature Review and Classification Framework. Future Internet 1, 59–87 (2009)Cappiello, C., Daniel, F., Matera, M.: A Quality Model for Mashup Components. In: Gaedke, M., Grossniklaus, M., Díaz, O. (eds.) ICWE 2009. LNCS, vol. 5648, pp. 236–250. Springer, Heidelberg (2009)Cappiello, C., Daniel, F., Matera, M., Pautasso, C.: Information Quality in Mashups. IEEE Internet Computing 14(4), 32–40 (2010)Cappiello, C., Matera, M., Picozzi, M., Daniel, F., Fernandez, A.: Quality-Aware Mashup Composition: Issues, Techniques and Tools. In: 8th International Conference on the Quality of Information and Communications Technology (QUATIC 2012), pp. 10–19 (2012)Fenton, N.E., Pfleeger, S.L.: Software Metrics: A Rigorous and Practical Approach, 2nd edn. International Thompson 1996, pp. I–XII, 1–638 (1996) ISBN 978-1-85032-275-7Fernandez, A., Insfran, E., Abrahão, S.: Usability evaluation methods for the web: A systematic mapping study. Information and Software Technology 53(8), 789–817 (2011)Garousi, V., Mesbah, A., Betin-Can, A., Mirshokraie, S.: A systematic mapping study of web application testing. Information and Software Technology 55(8), 1374–1396 (2013)Grammel, L., Storey, M.-A.: A survey of mashup development environments. In: Chignell, M., Cordy, J., Ng, J., Yesha, Y. (eds.) The Smart Internet. LNCS, vol. 6400, pp. 137–151. Springer, Heidelberg (2010)Hoyer, V., Fischer, M.: Market Overview of Enterprise Mashup Tools. In: Bouguettaya, A., Krueger, I., Margaria, T. (eds.) ICSOC 2008. LNCS, vol. 5364, pp. 708–721. Springer, Heidelberg (2008)ISO/IEC: ISO/IEC 25010 Systems and software engineering. Systems and software Quality Requirements and Evaluation (SQuaRE). System and software quality models (2011)Kitchenham, B., Charters, S.: Guidelines for performing Systematic Literature Reviews in Software Engineering. Version 2.3, ESBE Technical Report, Keele University, UK (2007)Mendes, E.: A systematic review on the Web engineering research. In: International Symposium on Empirical Software Engineering (ISESE 2005), pp. 498–507 (2005)OrangeLabs: State of the Art in Mashup tools, SocEDA project, pp. 1–59 (2011)Petersen, K., Feldt, R., Mujtaba, S., Mattsson, M.: Systematic mapping studies in software engineering. In: 12th International Conference on Evaluation and Assessment in Software Engineering (EASE), pp. 68–77 (2008)Raza, M., Hussain, F.K., Chang, E.: A methodology for quality-based mashup of data sources. In: 10th International Conference on Information Integration and Web-based Applications & Services (iiWAS 2008), pp. 528–533 (2008)Saeed, A.: A Quality-based Framework for Leveraging the Process of Mashup Component Selection (2009), https://gupea.ub.gu.se/handle/2077/21953Sharma, A., Hellmann, T.D., Maurer, F.: Testing of Web Services - A Systematic Mapping. In: 8th World Congress on Services (SERVICES 2012), pp. 346–352 (2012

    Hard diffraction from parton rescattering in QCD

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    We analyze the QCD dynamics of diffractive deep inelastic scattering. The presence of a rapidity gap between the target and diffractive system requires that the target remnant emerges in a color singlet state, which we show is made possible by the soft rescattering of the struck quark. This rescattering is described by the path-ordered exponential (Wilson line) in the expression for the parton distribution function of the target. The multiple scattering of the struck parton via instantaneous interactions in the target generates dominantly imaginary diffractive amplitudes, giving rise to an "effective pomeron" exchange. The pomeron is not an intrinsic part of the proton but a dynamical effect of the interaction. This picture also applies to diffraction in hadron-initiated processes. Due to the different color environment the rescattering is different in virtual photon- and hadron-induced processes, explaining the observed non-universality of diffractive parton distributions. This framework provides a theoretical basis for the phenomenologically successful Soft Color Interaction model which includes rescattering effects and thus generates a variety of final states with rapidity gaps. We discuss developments of the SCI model to account for the color coherence features of the underlying subprocesses.Comment: 12 pages, 9 figures, REVTeX4. Somewhat expanded and modified version, two new subsections added. To appear in PR

    Vibration-enhanced quantum transport

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    In this paper, we study the role of collective vibrational motion in the phenomenon of electronic energy transfer (EET) along a chain of coupled electronic dipoles with varying excitation frequencies. Previous experimental work on EET in conjugated polymer samples has suggested that the common structural framework of the macromolecule introduces correlations in the energy gap fluctuations which cause coherent EET. Inspired by these results, we present a simple model in which a driven nanomechanical resonator mode modulates the excitation energy of coupled quantum dots and find that this can indeed lead to an enhancement in the transport of excitations across the quantum network. Disorder of the on-site energies is a key requirement for this to occur. We also show that in this solid state system phase information is partially retained in the transfer process, as experimentally demonstrated in conjugated polymer samples. Consequently, this mechanism of vibration enhanced quantum transport might find applications in quantum information transfer of qubit states or entanglement.Comment: 7 pages, 6 figures, new material, included references, final published versio

    Characterization of the HD 108236 system with CHEOPS and TESS Confirmation of a fifth transiting planet

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    Context. The HD 108236 system was first announced with the detection of four small planets based on TESS data. Shortly after, the transit of an additional planet with a period of 29.54 d was serendipitously detected by CHEOPS. In this way, HD 108236 (V = 9.2) became one of the brightest stars known to host five small transiting planets (Rp < 3 R⊕). Aims. We characterize the planetary system by using all the data available from CHEOPS and TESS space missions. We use the flexible pointing capabilities of CHEOPS to follow up the transits of all the planets in the system, including the fifth transiting body. Methods. After updating the host star parameters by using the results from Gaia eDR3, we analyzed 16 and 43 transits observed by CHEOPS and TESS, respectively, to derive the planets’ physical and orbital parameters. We carried out a timing analysis of the transits of each of the planets of HD 108236 to search for the presence of transit timing variations. Results. We derived improved values for the radius and mass of the host star (R★ = 0.876 ± 0.007 R0 and M★ = 0.867-0.046+0.047M⊙). We confirm the presence of the fifth transiting planet f in a 29.54 d orbit. Thus, the HD 108236 system consists of five planets of Rb = 1.587±0.028, Rc = 2.122±0.025, Rd = 2.629 ± 0.031, Re = 3.008 ± 0.032, and Rf = 1.89 ± 0.04 [R⊕]. We refine the transit ephemeris for each planet and find no significant transit timing variations for planets c, d, and e. For planets b and f, instead, we measure significant deviations on their transit times (up to 22 and 28 min, respectively) with a non-negligible dispersion of 9.6 and 12.6 min in their time residuals. Conclusions. We confirm the presence of planet f and find no significant evidence for a potential transiting planet in a 10.9 d orbital period, as previously suggested. Further monitoring of the transits, particularly for planets b and f, would confirm the presence of the observed transit time variations. HD 108236 thus becomes a key multi-planetary system for the study of formation and evolution processes. The reported precise results on the planetary radii – together with a profuse RV monitoring – will allow for an accurate characterization of the internal structure of these planets

    A new dynamical modeling of the WASP-47 system with CHEOPS observations

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    Among the hundreds of known hot Jupiters (HJs), only five have been found to have companions on short-period orbits. Within this rare class of multiple planetary systems, the architecture of WASP-47 is unique, hosting an HJ (planet-b) with both an inner and an outer sub-Neptunian mass companion (-e and -d, respectively) as well as an additional non-transiting, long-period giant (-c). The small period ratio between planets -b and -d boosts the transit time variation (TTV) signal, making it possible to reliably measure the masses of these planets in synergy with the radial velocity (RV) technique. In this paper, we present new space- and ground-based photometric data of WASP-47b and WASP-47-d, including 11 unpublished light curves from the ESA mission CHaracterising ExOPlanet Satellite (CHEOPS). We analyzed the light curves in a homogeneous way together with all the publicly available data to carry out a global N-body dynamical modeling of the TTV and RV signals. We retrieved, among other parameters, a mass and density for planet -d of Md = 15.5 ± 0.8 M⊕ and ρd = 1.69 ± 0.22 g cm−3, which is in good agreement with the literature and consistent with a Neptune-like composition. For the inner planet (-e), we found a mass and density of Me = 9.0 ± 0.5 M⊕ and ρe = 8.1 ± 0.5 g cm−3, suggesting an Earth-like composition close to other ultra-hot planets at similar irradiation levels. Though this result is in agreement with previous RV plus TTV studies, it is not in agreement with the most recent RV analysis (at 2.8σ), which yielded a lower density compatible with a pure silicate composition. This discrepancy highlights the still unresolved issue of suspected systematic offsets between RV and TTV measurements. In this paper, we also significantly improve the orbital ephemerides of all transiting planets, which will be crucial for any future follow-up

    Correlated errors in Hipparcos parallaxes towards the Pleiades and the Hyades

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    We show that the errors in the Hipparcos parallaxes towards the Pleiades and the Hyades open clusters are spatially correlated over angular scales of 2 to 3 deg, with an amplitude of up to 2 mas. This correlation is stronger than expected based on the analysis of the Hipparcos catalog. We predict the parallaxes of individual cluster members, pi_pm, from their Hipparcos proper motions, assuming that all cluster members have the same space velocity. We compare pi_pm with their Hipparcos parallaxes, pi_Hip, and find that there are significant spatial correlations in pi_Hip. We derive a distance modulus to the Pleiades of 5.58 +- 0.18 mag using the radial-velocity gradient method. This value, agrees very well with the distance modulus of 5.60 +- 0.04 mag determined using the main-sequence fitting technique, compared with the value of 5.33 +- 0.06 inferred from the average of the Hipparcos parallaxes of the Pleiades members. We show that the difference between the main-sequence fitting distance and the Hipparcos parallax distance can arise from spatially correlated errors in the Hipparcos parallaxes of individual Pleiades members. Although the Hipparcos parallax errors towards the Hyades are spatially correlated in a manner similar to those of the Pleiades, the center of the Hyades is located on a node of this spatial structure. Therefore, the parallax errors cancel out when the average distance is estimated, leading to a mean Hyades distance modulus that agrees with the pre-Hipparcos value. We speculate that these spatial correlations are also responsible for the discrepant distances that are inferred using the mean Hipparcos parallaxes to some open clusters. Finally, we note that our conclusions are based on a purely geometric method and do not rely on any models of stellar isochrones.Comment: 33 pages including 10 Figures, revised version accepted for publication in Ap

    Mc Neil's Nebula in Orion: The Outburst History

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    We present a sequence of I-band images obtained at the Venezuela 1m Schmidt telescope during the outburst of the nebula recently discovered by J.W. McNeil in the Orion L1630 molecular cloud. We derive photometry spanning the pre-outburst state and the brightening itself, a unique record including 14 epochs and spanning a time scale of ~5 years. We constrain the beginning of the outburst at some time between Oct. 28 and Nov. 15, 2003. The light curve of the object at the vertex of the nebula, the likely exciting source of the outburst, reveals that it has brightened ~5 magnitudes in about 4 months. The time scale for the nebula to develop is consistent with the light travel time, indicating that we are observing light from the central source scattered by the ambient cloud into the line of sight. We also show recent FLWO optical spectroscopy of the exciting source and of the nearby HH 22. The spectrum of the source is highly reddened; in contrast, the spectrum of HH 22 shows a shock spectrum superimposed on a continuum, most likely due to reflected light from the exciting source reaching the HH object through a much less reddened path. The blue portion of this spectrum is consistent with an early B spectral type, similar to the early outburst spectrum of the FU Ori variable V1057 Cyg; we estimate a luminosity of L ~219 Lsun. The eruptive behavior of the McNeil nebula source, its spectroscopic characteristics and luminosity, suggest we may be witnessing an FU Ori event on its way to maximum. Further monitoring of this object will decide whether it qualifies as a member of this rare class of objects.Comment: 13 pages, 4 figures, accepted to ApJ Letter

    Gravel pits support waterbird diversity in an urban landscape

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    We assessed the benefit of 11 gravel pits for the settlement of waterbird communities in an urbanized area lacking natural wetlands. Gravel pits captured 57% of the regional species pool of aquatic birds. We identified 39 species, among which five were regionally rare. We used the Self Organizing Map algorithm to calculate the probabilities of presence of species, and to bring out habitat conditions that predict assemblage patterns. The age of the pits did not correlate with assemblage composition and species richness. There was a positive influence of macrophyte cover on waterbird species richness. Larger pits did not support more species, but species richness increased with connectivity. As alternative wetland habitats, gravel pits are attractive to waterbirds, when they act as stepping stones that ensure connectivity between larger natural and/or artificial wetlands separated in space
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