156 research outputs found

    Visualizing Object Oriented Software in Three Dimensions

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    There is increasing evidence that it is possible to perceive and understand increasingly comple x information systems if they are displayed a s graphical objects in a three dimensional space . Object-oriented software provides an interestin g test case - there is a natural mapping fro m software objects to visual objects . In this paper we explore two areas. 1) Information perception : we are running controlled experiments to determine empirically if our initial premise is valid; how much more (or less) can be understoo d in 3D than in 2D? 2) Layout: our strategy is to combine partially automatic layout with manua l layout. This paper presents a brief overview of the project, the software architecture and some preliminary empirical results

    Using Microservices to Customize Multi-Tenant SaaS: From Intrusive to Non-Intrusive

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    Customization is a widely adopted practice on enterprise software applications such as Enterprise resource planning (ERP) or Customer relation management (CRM). Software vendors deploy their enterprise software product on the premises of a customer, which is then often customized for different specific needs of the customer. When enterprise applications are moving to the cloud as mutli-tenant Software-as-a-Service (SaaS), the traditional way of on-premises customization faces new challenges because a customer no longer has an exclusive control to the application. To empower businesses with specific requirements on top of the shared standard SaaS, vendors need a novel approach to support the customization on the multi-tenant SaaS. In this paper, we summarize our two approaches for customizing multi-tenant SaaS using microservices: intrusive and non-intrusive. The paper clarifies the key concepts related to the problem of multi-tenant customization, and describes a design with a reference architecture and high-level principles. We also discuss the key technical challenges and the feasible solutions to implement this architecture. Our microservice-based customization solution is promising to meet the general customization requirements, and achieves a balance between isolation, assimilation and economy of scale

    Model-based fleet deployment in the IoT–edge–cloud continuum

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    With the increasing computing and networking capabilities, IoT devices and edge gateways have become part of a larger IoT–edge–cloud computing continuum, where processing and storage tasks are distributed across the whole network hierarchy, not concentrated only in the cloud. At the same time, this also introduced continuous delivery practices to the development of software components for network-connected gateways and sensing/actuating nodes. These devices are placed on end users’ premises and are characterized by continuously changing cyber-physical contexts, forcing software developers to maintain multiple application versions and frequently redeploy them on a distributed fleet of devices with respect to their current contexts. Doing this correctly and efficiently goes beyond manual capabilities and requires an intelligent and reliable automated solution. This paper describes a model-based approach to automatically assigning multiple software deployment plans to hundreds of edge gateways and connected IoT devices implemented in collaboration with a smart healthcare application provider. From a platform-specific model of an existing edge computing platform, we extract a platform-independent model that describes a list of target devices and a pool of available deployment plans. Next, we use constraint solving to automatically assign deployment plans to devices at once with respect to their specific contexts. The result is transformed back into the platform-specific model and includes a suitable deployment plan for each device, which is then consumed by our engine to deploy software components not only on edge gateways but also on their downstream IoT devices with constrained resources and connectivity. We validate the approach with a fleet deployment prototype integrated into a DevOps toolchain used by the partner application provider. Initial experiments demonstrate the viability of the approach and its usefulness in supporting DevOps for edge and IoT software development.publishedVersio

    The Isotope Effect in d-Wave Superconductors

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    Based on recently proposed anti-ferromagnetic spin fluctuation exchange models for dx2y2d_{x^2-y^2}-superconductors, we show that coupling to harmonic phonons {\it{cannot}} account for the observed isotope effect in the cuprate high-TcT_c materials, whereas coupling to strongly anharmonic multiple-well lattice tunneling modes {\it{can}}. Our results thus point towards a strongly enhanced {\it{effective}} electron-phonon coupling and a possible break-down of Migdal-Eliashberg theory in the cuprates.Comment: 12 pages + 2 figures, Postscript files, all uuencoded Phys. Rev. Lett. (1995, to be published

    Rôle de la charge inorganique des dentifrices sur la formation des biofilms

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    Biofilms have a significant effect on the development of numerous micro-organisms, as well in the case of waters intended for human consumption, as in the case of greywaters or natural resources. However, on the base of many analyses carried out on hundreds of biofilms, it was provenwithout any doubt that all the studied biofilms contain inorganic products sometimes in significant quantity. The characteristics of these inorganic products (formula, crystallinity) can be determined using the infrared absorption spectrometry based on CsBr micro-pellet analysis. These various products are analysed semi-quantitatively either directly by the measure of their absorbance or by comparing the absorbance before and after micro-pellet calcination. The calcination leads to the elimination of the organic compounds. The results show that the inorganic products are particularly abundant in the biofilms developed in the wastewater drains of domestic wash-hand basins, because of their remarkable abundance, due to very fast development kinetic. Thanks to the analysis methods, it is proven that silicon inorganic charges of the toothpastes are the main source of the development of these biofilms. In the case of non-domestic wash-hand basins, without toothpaste use, the biofilm development kinetic is lower

    Examining "The end of revolution": a foretaste of Wang Hui’s thought

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    Wang Hui is a significant contemporary Chinese thinker and a key representative of Chinese New Left thought. This article provides a critical review of some of the themes that emerge from Wang’s The End of Revolution as a means of situating his position in China’s intellectual landscape, with a particular mind to exploring the historicity of Wang’s thought as it informs his views. The essay engages some of the key discursive threads in The End of Revolution and provides a critical overview of Wang’s positions on neoliberalism, the tension between Western articulations of modernity and China’s own self-image

    Effects of temperature and dissolved CO2 on the scaling of water in the presence of copper and zinc

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    In this study, through the method of rapid controlled precipitation (RCP), the influence of temperature and dissolved CO2 on the scaling capacity of mineral water in the presence of copper and zinc ions was studied in laboratory experiments. The results indicated that with a rise in temperature or concentration of dissolved CO2, the scaling time of Salvetat water greatly decreased and the rate of precipitation considerably increased; therefore, the minimum dosage of copper or zinc ion for achieving total inhibition of scaling needed to be increased, which would provide better guidance for practical use of metal ions in inhibiting the scaling of drinking water

    Removal of algal blooms from freshwater by the coagulation-magnetic separation method

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    This research investigated the feasibility of changing waste into useful materials for water treatment and proposed a coagulation-magnetic separation technique. This technique was rapid and highly effective for clearing up harmful algal blooms in freshwater and mitigating lake eutrophication. A magnetic coagulant was synthesized by compounding acid-modified fly ash with magnetite (Fe 3 O 4 ). Its removal effects on algal cells and dissolved organics in water were studied. After mixing, coagulation, and magnetic separation, the flocs obtained from the magnet surface were examined by SEM. Treated samples were withdrawn for the content determination of chlorophyll-a, turbidity, chemical oxygen demand (COD), total nitrogen, and total phosphorus. More than 99 % of algal cells were removed within 5 min after the addition of magnetic coagulant at optimal loadings (200 mg L -1 ). The removal efficiencies of COD, total nitrogen, and phosphorus were 93, 91, and 94 %, respectively. The mechanism of algal removal explored preliminarily showed that the magnetic coagulant played multiple roles in mesoporous adsorption, netting and bridging, as well as high magnetic responsiveness to a magnetic field. The magnetic-coagulation separation method can rapidly and effectively remove algae from water bodies and greatly mitigate eutrophication of freshwater using a new magnetic coagulant. The method has good performance, is low cost, can turn waste into something valuable, and provides reference and directions for future pilot and production scale-ups
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