4,962 research outputs found

    Model Driven Mutation Applied to Adaptative Systems Testing

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    Dynamically Adaptive Systems modify their behav- ior and structure in response to changes in their surrounding environment and according to an adaptation logic. Critical sys- tems increasingly incorporate dynamic adaptation capabilities; examples include disaster relief and space exploration systems. In this paper, we focus on mutation testing of the adaptation logic. We propose a fault model for adaptation logics that classifies faults into environmental completeness and adaptation correct- ness. Since there are several adaptation logic languages relying on the same underlying concepts, the fault model is expressed independently from specific adaptation languages. Taking benefit from model-driven engineering technology, we express these common concepts in a metamodel and define the operational semantics of mutation operators at this level. Mutation is applied on model elements and model transformations are used to propagate these changes to a given adaptation policy in the chosen formalism. Preliminary results on an adaptive web server highlight the difficulty of killing mutants for adaptive systems, and thus the difficulty of generating efficient tests.Comment: IEEE International Conference on Software Testing, Verification and Validation, Mutation Analysis Workshop (Mutation 2011), Berlin : Allemagne (2011

    Inquiring the usage of aspect-oriented programming: an empirical study

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    International audienceBack in 2001, the MIT announced aspect-orientedprogramming as a key technology in the next 10 years.Nowadays, 8 years later, AOP is not widely adopted.Several reasons can explain this distrust in front ofAOP, and one of them is the lack of robust tools foranalysis, testing and maintenance. In order to developdedicated solutions for assisting the development withAOP, and increase its adoption, we need to understandhow it is actually used. In this paper we analyze 38aspect-oriented open source projects with respect tothe impact of aspects on the projects, and to coverageof the language features. This reveals that AOP iscurrently used in a cautious way. This work is a firststep to built support and development tools dedicatedto actual practices for AOP, based on empirical usage profiles

    Characterisation of wheel/rail roughness and track decay rates on a tram network

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    From the beginning of 2019, the new CNOSSOS-EU method shall be used for strategic noise mapping in application of Directive 2002/49/EC instead of national noise prediction methods. For the railway part, the operators are responsible for providing input data describing the different noise sources characterising the railway system. Concerning the rolling noise, the vehicle and the track have to be distinguished by providing specific transfer functions and wheel/rail roughness spectra. For conventional railways, default values are given in the CNOSSOS-EU method and national operators generally have experimental data at their disposal to evaluate these new input parameters. This is not the case for tram networks, for which very few measurements exist, notably concerning the wheel and rail roughness or the track transfer function. In 2018, Acoucité and IFSTTAR performed an acoustic test campaign on a French tram network in order to propose tram input data from pass-by measurements corresponding to various sites and vehicles. In this paper, the results concerning the direct measurements of wheel/rail roughness and track decay rates (a key parameter for the assessment of the track transfer function) are presented and discussed. The main differences with data corresponding to conventional railways are highlighted

    Modelling the impact of COVID-19-related programme interruptions on visceral leishmaniasis in India

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    BACKGROUND: In March 2020, India declared a nationwide lockdown to control the spread of coronavirus disease 2019. As a result, control efforts against visceral leishmaniasis (VL) were interrupted. METHODS: Using an established age-structured deterministic VL transmission model, we predicted the impact of a 6- to 24-month programme interruption on the timeline towards achieving the VL elimination target as well as on the increase of VL cases. We also explored the potential impact of a mitigation strategy after the interruption. RESULTS: Delays towards the elimination target are estimated to range between 0 and 9 y. Highly endemic settings where control efforts have been ongoing for 5-8 y are most affected by an interruption, for which we identified a mitigation strategy to be most relevant. However, more importantly, all settings can expect an increase in the number of VL cases. This increase is substantial even for settings with a limited expected delay in achieving the elimination target. CONCLUSIONS: Besides implementing mitigation strategies, it is of great importance to try and keep the duration of the interruption as short as possible to prevent new individuals from becoming infected with VL and continue the efforts towards VL elimination as a public health problem in India

    A cell-based smoothed finite element method for kinematic limit analysis

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    This paper presents a new numerical procedure for kinematic limit analysis problems, which incorporates the cell-based smoothed finite element method with second-order cone programming. The application of a strain smoothing technique to the standard displacement finite element both rules out volumetric locking and also results in an efficient method that can provide accurate solutions with minimal computational effort. The non-smooth optimization problem is formulated as a problem of minimizing a sum of Euclidean norms, ensuring that the resulting optimization problem can be solved by an efficient second-order cone programming algorithm. Plane stress and plane strain problems governed by the von Mises criterion are considered, but extensions to problems with other yield criteria having a similar conic quadratic form or 3D problems can be envisaged

    Isolation of bis-indole alkaloids with antileishmanial and antibacterial activities from Peschiera van heurkii (syn. Tabernaemontana van heurkii)

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    Des extraits de feuilles et d'écorces de tiges de #Peschiera van heurkii (Muell. Arg.) L. Allorge, (Syn. #Tabernaemontana van heurkii Muell. Arg.) ont montré une activité antileishmanienne et antibactérienne significative. Les activités étaient concentrées dans les fractions alcaloïdiques, desquelles ont été isolés et identifiés 20 alcaloïdes indoliques et bis-indoliques. La plus forte activité leishmanicide et antibactérienne fut observée avec les alcaloïdes dimères conodurine (1), N-démethyle - conodurine (=gabunine) et conoduramine. Les deux premiers composés se sont avérés faiblement toxiques vis-à-vis des cellules hôtes les macrophages, tout en présentant une forte toxicité pour les formes intracellulaires du parasite. #In vitro$, l'alcaloïde (1) s'est avéré moins actif que le médicament de référence, le glucantime (=N-methylglucamine antimonate). (Résumé d'auteur

    ALMA reveals the molecular gas properties of five star-forming galaxies across the main sequence at 3

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    International audienceWe present the detection of CO(5-4) with S/N> 7 - 13 and a lower CO transition with S/N > 3 (CO(4-3) for 4 galaxies, and CO(3-2) for one) with ALMA in band 3 and 4 in five main sequence star-forming galaxies with stellar masses 3-6x10^10 M/M_sun at 3 < z < 3.5. We find a good correlation between the total far-infrared luminosity LFIR and the luminosity of the CO(5-4) transition L'CO(5-4), where L'CO(5-4) increases with SFR, indicating that CO(5-4) is a good tracer of the obscured SFR in these galaxies. The two galaxies that lie closer to the star-forming main sequence have CO SLED slopes that are comparable to other star-forming populations, such as local SMGs and BzK star-forming galaxies; the three objects with higher specific star formation rates (sSFR) have far steeper CO SLEDs, which possibly indicates a more concentrated episode of star formation. By exploiting the CO SLED slopes to extrapolate the luminosity of the CO(1-0) transition, and using a classical conversion factor for main sequence galaxies of alpha_CO = 3.8 M_sun(K km s^-1 pc^-2)^-1, we find that these galaxies are very gas rich, with molecular gas fractions between 60 and 80%, and quite long depletion times, between 0.2 and 1 Gyr. Finally, we obtain dynamical masses that are comparable with the sum of stellar and gas mass (at least for four out of five galaxies), allowing us to put a first constraint on the alpha_CO parameter for main sequence galaxies at an unprecedented redshift
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