274 research outputs found

    Using Graph Transformation Systems to Specify and Verify Data Abstractions

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    This paper proposes an approach for the specification of the behavior of software components that implement data abstractions. By generalizing the approach of behavior models using graph transformation, we provide a concise specification for data abstractions that describes the relationship between the internal state, represented in a canonical form, and the observers of the component. Graph transformation also supports the generation of behavior models that are amenable to verification. To this end, we provide a translation approach into an LTL model on which we can express useful properties that can be model-checked with a SAT solver

    Cloud service localisation

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    The essence of cloud computing is the provision of software and hardware services to a range of users in dierent locations. The aim of cloud service localisation is to facilitate the internationalisation and localisation of cloud services by allowing their adaption to dierent locales. We address the lingual localisation by providing service-level language translation techniques to adopt services to dierent languages and regulatory localisation by providing standards-based mappings to achieve regulatory compliance with regionally varying laws, standards and regulations. The aim is to support and enforce the explicit modelling of aspects particularly relevant to localisation and runtime support consisting of tools and middleware services to automating the deployment based on models of locales, driven by the two localisation dimensions. We focus here on an ontology-based conceptual information model that integrates locale specication in a coherent way

    AIOCJ: A Choreographic Framework for Safe Adaptive Distributed Applications

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    We present AIOCJ, a framework for programming distributed adaptive applications. Applications are programmed using AIOC, a choreographic language suited for expressing patterns of interaction from a global point of view. AIOC allows the programmer to specify which parts of the application can be adapted. Adaptation takes place at runtime by means of rules, which can change during the execution to tackle possibly unforeseen adaptation needs. AIOCJ relies on a solid theory that ensures applications to be deadlock-free by construction also after adaptation. We describe the architecture of AIOCJ, the design of the AIOC language, and an empirical validation of the framework.Comment: Technical Repor

    Performance evaluation of an ORC unit integrated to a waste heat recovery system in a steel mill

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    Waste heat revalorization creates interesting opportunities to energy intensive industries. In the present project, a large-scale ORC pilot plant along with a waste heat recovery unit (WHRU) in a steel mill has been designed, commissioned and operated. The plant is part of the European Commission funded PITAGORAS project and it has been installed at ORI MARTIN in Brescia (Italy). Waste heat is recovered from the fumes of the Electric Arc Furnace (EAF) to produce saturated steam which is then delivered to a district heating (DH) network during heating season and to the ORC for electricity generation during the rest of the year. The main challenge was the integration of these systems in a single plant since the heat source is highly unstable and steady heat load is preferable for the DH and ORC for their safe operation. A steam accumulator of 150m3 volume was implemented between the WHRU and the ORC/DH systems to maintain a steady discharge pressure, to reduce the fast transients and to extend the supply over longer periods. The ORC has a nominal power output of 1,8MW and the preliminary results of the first weeks of operation of the ORC unit resulted in a net efficiency of 21.7%. Currently the plant is undergoing monitoring campaign which will provide additional data to further evaluate and optimize the system.The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007-2013 under grant agreement n° ENER / FP7EN / 314596 / PITAGORAS

    Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

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    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in the form of beads. Degradation of TCE by the anaerobic and dichloroethylene (DCE) by aerobic cultures was studied using dual reactors - anaerobic biofilm and aerobic immobilized bed reactor. The minimal mineral salt (MMS) medium saturated with TCE was pumped at the rate of 1 ml per hour into the anaerobic reactor. The MMS medium saturated with DCE and supplemented with xylenes and toluene (3 ppm each) was pumped at the rate of 1 ml per hour into the fluidized air-uplift-type reactor containing the immobilized aerobic cells. The concentrations of TCE and DCE and the metabolites formed during their degradation by the anaerobic and aerobic cultures were monitored by GC. The preliminary study suggests that the anaerobic and aerobic cultures of our isolates can degrade TCE and DCE

    Analysis of Energy-Efficient Buildings through Simulation and Formal Methods

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    In the last few years, the increasing interest in energy saving has led to invest resources in many research fields, in order to develop new tech-nologies to reduce energy consumption. One such field is energy man-agement systems for buildings. The interactions between the system con-trolling the building and its environment are complicated by the fact that they involve important timing properties, which can be expressed through a variety of formalisms. This paper introduces a formal model, expressed in a temporal logic language, through which designers can evaluate the temporal behavior of buildings\u2019 energy management systems. To this end, the formal model is analyzed through simulation, that is, through the generation of traces satisfying the temporal logic model

    Using graph transformation systems to specify and verify data abstractions

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    This paper proposes an approach for the specification of the behavior of software components that implement data abstractions. By generalizing the approach of behavior models using graph transformation, we provide a concise specification for data abstractions that describes the relationship between the internal state, represented in a canonical form, and the observers of the component. Graph transformation also supports the generation of behavior models that are amenable to verification. To this end, we provide a translation approach into an LTL model on which we can express useful properties that can be model-checked with a SAT solver
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