1,930 research outputs found

    Overcoming Language Dichotomies: Toward Effective Program Comprehension for Mobile App Development

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    Mobile devices and platforms have become an established target for modern software developers due to performant hardware and a large and growing user base numbering in the billions. Despite their popularity, the software development process for mobile apps comes with a set of unique, domain-specific challenges rooted in program comprehension. Many of these challenges stem from developer difficulties in reasoning about different representations of a program, a phenomenon we define as a "language dichotomy". In this paper, we reflect upon the various language dichotomies that contribute to open problems in program comprehension and development for mobile apps. Furthermore, to help guide the research community towards effective solutions for these problems, we provide a roadmap of directions for future work.Comment: Invited Keynote Paper for the 26th IEEE/ACM International Conference on Program Comprehension (ICPC'18

    The contamination of the surface of Vesta by impacts and the delivery of the dark material

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    The Dawn spacecraft observed the presence of dark material, which in turn proved to be associated with OH and H-rich material, on the surface of Vesta. The source of this dark material has been identified with the low albedo asteroids, but it is still a matter of debate whether the delivery of the dark material is associated with a few large impact events, to micrometeorites or to the continuous, secular flux of impactors on Vesta. The continuous flux scenario predicts that a significant fraction of the exogenous material accreted by Vesta should be due to non-dark impactors likely analogous to ordinary chondrites, which instead represent only a minor contaminant in the HED meteorites. We explored the continuous flux scenario and its implications for the composition of the vestan regolith, taking advantage of the data from the Dawn mission and the HED meteorites. We used our model to show that the stochastic events scenario and the micrometeoritic flux scenario are natural consequences of the continuous flux scenario. We then used the model to estimate the amounts of dark and hydroxylate materials delivered on Vesta since the LHB and we showed how our results match well with the values estimated by the Dawn mission. We used our model to assess the amount of Fe and siderophile elements that the continuous flux of impactors would mix in the vestan regolith: concerning the siderophile elements, we focused our attention on the role of Ni. The results are in agreement with the data available on the Fe and Ni content of the HED meteorites and can be used as a reference frame in future studies of the data from the Dawn mission and of the HED meteorites. Our model cannot yet provide an answer to the fate of the missing non-carbonaceous contaminants, but we discuss possible reasons for this discrepancy.Comment: 31 pages, 7 figures, 4 tables. Accepted for publication on the journal ICARUS, "Dark and Bright Materials on Vesta" special issu

    PCR-RFLP approaches to easily identify Pleuronectes platessa from other flatfishes: a rapid and efficient tool to control label information

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    Submitted by Patrícia Correia ([email protected]) on 2017-11-21T09:48:07Z No. of bitstreams: 1 Caldelli et al. - 2014 - PCR- RFLP approaches to easily identify Pleuronect.pdf: 566430 bytes, checksum: b24dccaef6a451b030a229b797e2e7c0 (MD5) Approved for entry into archive by Patrícia Correia([email protected]) on 2017-11-21T09:48:34Z (GMT) No. of bitstreams: 1 Caldelli et al. - 2014 - PCR- RFLP approaches to easily identify Pleuronect.pdf: 566430 bytes, checksum: b24dccaef6a451b030a229b797e2e7c0 (MD5) Made available in DSpace on 2017-11-21T09:48:34Z (GMT). No. of bitstreams: 1 Caldelli et al. - 2014 - PCR- RFLP approaches to easily identify Pleuronect.pdf: 566430 bytes, checksum: b24dccaef6a451b030a229b797e2e7c0 (MD5) Previous issue date: 201

    Biomechanical analysis of the upper body during overhead industrial tasks using electromyography and motion capture integrated with digital human models

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    In this paper, we present a biomechanical analysis of the upper body, which includes upper-limb, neck and trunk, during the execution of overhead industrial tasks. The analysis is based on multiple performance metrics obtained from a biomechanical analysis of the worker during the execution of a specific task, i.e. an overhead drilling task, performed at different working heights. The analysis enables a full description of human movement and internal load state during the execution of the task, thought the evaluation of joint angles, joint torques and muscle activations. A digital human model is used to simulate and replicate the worker’s task in a virtual environment. The experiments were conduced in laboratory setting, where four subjects, with different anthropometric characteristics, have performed 48 drilling tasks in two different working heights defined as low configuration and middle configuration. The results of analysis have impact on providing the best configuration of the worker within the industrial workplace and/or providing guidelines for developing assistance devices which can reduce the physical overloading acting on the worker’s body

    Development of site-specific biomechanical indices for estimating injury risk in cycling

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    In this paper we present novel biomechanical indices for site-specific assessment of injury risk in cycling. The indices are built from a multifactorial analysis based on the kinematics and kinetics of the cyclist from the biomechanical side, and muscle excitations and muscle synergies from the neurophysiological side. The indices are specifics for three body regions (back, knee, ankle) which are strongly affected by overuse injuries in cycling. We use these indices for injury risks analysis of a recreational cyclist, who offered to participate in the experiments. The preliminary results are promising towards the use of such indices for planning and/or evaluating training schedule with the final goal of reducing non-traumatic injuries in cycling

    Superconducting gap anisotropy of LuNi2B2C thin films from microwave surface impedance measurements

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    Surface impedance measurements of LuNi2B2C superconducting thin films as a function of temperature have been performed down to 1.5 K and at 20 GHz using a dielectric resonator technique. The magnetic penetration depth closely reproduces the standard B.C.S. result, but with a reduced value of the energy gap at low temperature. These data provide evidence for an anisotropic s-wave character of the order parameter symmetry in LuNi2B2C. From the evaluation of the real part of complex conductivity, we have observed constructive (type II) coherence effects in the electromagnetic absorption below Tc.Comment: 15 pages, 4 figure

    Spectrophotometric properties of dwarf planet Ceres from the VIR spectrometer on board the Dawn mission

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    We study the spectrophotometric properties of dwarf planet Ceres in the VIS-IR spectral range by means of hyper-spectral images acquired by the VIR imaging spectrometer on board the NASA Dawn mission. Disk-resolved observations with a phase angle within the 7<α<1327^{\circ}<\alpha<132^{\circ} interval were used to characterize Ceres' phase curve in the 0.465-4.05 μ\mum spectral range. Hapke's model was applied to perform the photometric correction of the dataset, allowing us to produce albedo and color maps of the surface. The VV-band magnitude phase function of Ceres was fitted with both the classical linear model and H-G formalism. The single-scattering albedo and the asymmetry parameter at 0.55μ\mum are w=0.14±0.02w=0.14\pm0.02 and ξ=0.11±0.08\xi=-0.11\pm0.08, respectively (two-lobe Henyey-Greenstein phase function); the modeled geometric albedo is 0.094±0.0070.094\pm0.007; the roughness parameter is θˉ=29±6\bar{\theta}=29^{\circ}\pm6^{\circ}. Albedo maps indicate small variability on a global scale with an average reflectance of 0.034±0.0030.034 \pm 0.003. Isolated areas such as the Occator bright spots, Haulani, and Oxo show an albedo much higher than average. We measure a significant spectral phase reddening, and the average spectral slope of Ceres' surface after photometric correction is 1.1%kA˚11.1\%k\AA^{-1} and 0.85%kA˚10.85\%k\AA^{-1} at VIS and IR wavelengths, respectively. Broadband color indices are VR=0.38±0.01V-R=0.38\pm0.01 and RI=0.33±0.02R-I=0.33\pm0.02. H-G modeling of the VV-band magnitude phase curve for α<30\alpha<30^{\circ} gives H=3.14±0.04H=3.14\pm0.04 and G=0.10±0.04G=0.10\pm0.04, while the classical linear model provides V(1,1,0)=3.48±0.03V(1,1,0^{\circ})=3.48\pm0.03 and β=0.036±0.002\beta=0.036\pm0.002. The comparison with spectrophotometric properties of other minor bodies indicates that Ceres has a less back-scattering phase function and a slightly higher albedo than comets and C-type objects. However, the latter represents the closest match in the usual asteroid taxonomy.Comment: 14 pages, 20 figures, published online on Astronomy and Astrophysics on 13 February 2017. Revised to reflect minor changes in text and figures made in proofs, updated value of V-R and R-
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