1,354,444 research outputs found
A conceptual framework for collective adaptive systems
No full textIn this paper we propose a conceptual framework to characterize Collective Adaptive Systems. By following the separation of concerns we represent these systems as a composition of three components: execution, context and adaptation, and we give a formal definition of all their concepts, defining their corresponding semantics and pointing out the interactions among them. Moreover, we formalize also the main properties that these systems should have, abstracting from any precise specification language or mode
A framework to support the design of a regenerative indoor environment
No full textIn recent decades, a new generation of “green indoor” spaces has fulfilled the latest regulations and guidelines for a carbon-neutral society. Their targets are reachable through certifications embracing sets of measures and the adverse effects on occupants. Notwithstanding this, it has constituted a significant step forward in building design. However, the challenges given by climate change and the ecological crises lead to the need for new disruptive approaches to indoor design and function, enhancing human health and adopting regenerative design” at the forefront of buildings’ conception. Besides the positive energyperformance attributes, the creation of a Regenerative Indoor Environment utilizes appropriate construction technologies and systems, to reinforce human
health, and enhance users’ experience. This regenerative paradigm shift foresees putting ecosystems at the centre and the users’ psycho-physiological wellbeing, thus magnifying their collaboration. Despite regenerative design gaining some attention, a framework towards its implementation promoting the actual performances of the indoor environment is still missing, and designers do navigate among guidelines with no apparent performance indicators to be achieved, technologies to be implemented, or methodologies for postoccupancy evaluations. These three levels, constituting a stepwise methodology, are addressed by the authors within the sections of this paper, and validated as an example of the office buildings’ typology. i) What characterizes a Regenerative Indoor Environment? ii) What technical solutions underpin the realization of a Regenerative Indoor Environment? iii) What methods or standards are crucial for its evaluation? With these premises, the paper contributes to supporting the creation of a regenerative indoor’ design, by sampling and outlining regenerative indoor performances to be obtained, describing the adequate tools to implement them, as well as by displaying approaches and solutions for their final verification
A Context-Aware Framework for Business Processes Evolution
No full textRun-time adaptability is a key feature of dynamic business environments, where the processes need to be constantly refined and restructured to deal with exceptional situations and changing requirements. The execution of such a system results in a set of adapted process variants instantiated on the same process model but dynamically restructured to handle specific contexts. Process evolution exploits the information on process variants to identify the best performing recurring adaptations and adopt them as general solutions in the process model. However, process variants are strictly related to specific execution contexts and cannot be adopted as general solutions. We propose a framework supporting context-aware evolution of business processes based on process instance execution and adaptation history. Instead of looking for recurring adaptations, we propose to look for recurring adaptation needs (i.e., process instances with the same context constraint violation and system configuration). Based on the analysis of adapted instances, we automatically construct and rank corrective evolution variants which can handle the problematic context. At the same time, we try to identify preventive evolution variants by constructing process variants which can prevent the adaptation need. We demonstrate the benefits of our approach using a car logistics scenario
Np95 è coinvolta nel mantenimento dell’informazione epigenetica della cromatina associata a repressione trascrizionale in cellule replicanti e P19 indotte a differenziare a neuroni.
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A Parametric Communication Model for the Verification of BPEL4WS Compositions
No full textIn this paper we describe an approach for the verification of Web service compositions defined by a set of BPEL4WS processes. The key aspect of such a verification task is the model adopted for representing the communications among the services participating to the composition. Indeed, these communications are asynchronous and buffered in the existing execution frameworks, while most verification approaches adopt a synchronous communication model for efficiency reasons. In our approach, we model the asynchronous nature of Web service interactions without introducing buffers, by allowing a reordering of the messages exchanged during these interactions. This way, we can provide an accurate model of a wider class of service composition scenarios, while preserving an efficient performance in verification
Towards Correctness Assurance in Adaptive Service-Based Applications
No full textService-based applications (SBAs) increasingly have to become adaptive in order to operate and evolve in highly dynamic environments. Research on SBAs thus has already produced a range of adaptation techniques and strategies. However, adaptive SBAs are prone to specific failures that would not occur in “static” applications. Examples are faulty adaptation behaviours due to changes not anticipated during design-time, or conflicting adaptations due to concurrently occurring events. For adaptive SBAs to become reliable and thus applicable in practice, novel techniques that ensure the correctness of adaptations are needed. To pave the way towards those novel techniques, this paper identifies different kinds of adaptation-specific failures. Based on a classification of existing adaptation approaches and generic correctness assurance techniques, we discuss how adaptation-specific failures can be addressed and where new advanced techniques for correctness assurance of adaptations are required
Finite State Verification for the Asynchronous Pi-Calculus
No full textThe pi-calculus is a development of CCS that has the ability of communicating channel names. The asynchronous pi-calculus is a variant of the pi-calculus where message emission is non-blocking.
Finite state verification is problematic in this context, since even very simple asynchronous pi-processes give rise to infinite-state behaviors. This is due to phenomena that are typical of calculi with name passing and to phenomena that are peculiar of asynchronous calculi.
We present a finite-state characterization of a family of finitary asynchronous pi-processes by exploiting History Dependent transition systems with Negative transitions (HDN), an extension of labelled transition systems particularly suited for dealing with concurrent calculi with name passing. We also propose an algorithm based on HDN to verify asynchronous bisimulation for finitary pi-processe
Licenziamento per eccessiva morbilità: cambio di rotta della giurisprudenza?
No full textLa nota commenta la sentenza della Cassazione civile, sez. lav., 4 settembre 2014, n. 18678, che ha ritenuto legittimo il licenziamento per giustificato motivo oggettivo irrogato a causa di reiterate assenze per malattia del lavoratore, senza superamento del periodo di comporto. Rimangono tuttavia notevoli interrogativi circa il rapporto tra la disciplina del recesso e la generale norma codicistica di cui all’art. 2110 c.c
Adaptation of Service-based Business Processes by Context-Aware Replanning
No full textService-based business processes are typically used by organizations to achieve business goals through the coordinated execution of a set of activities implemented as services and service compositions. Since they are executed in dynamic, open and non-deterministic environments, business processes often need to be adapted to exogenous context changes and execution problems. In this paper we provide an adaptation approach that can automatically adapt business processes to run-time context changes that impede achievement of a business goal. We define a formal framework that adopts planning techniques to automatically derive necessary adaptation activities on demand. The adaptation consists in identifying recovery activities that guarantee that the execution of a business process can be successfully resumed and, as a consequence, the business goals are achieved. The solution proposed is evaluated on a real-world scenario from the logistics domain
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