1,721,002 research outputs found
Fair Pi
No full textIn this paper, we define fair computations in the π-calculus [18]. We follow Costa and Stirling’s approach for CCS-like languages but exploit a more natural labeling method of process actions to filter out unfair process executions. The new labeling allows us to prove all the significant properties of the original one, such as unicity, persistence and disappearance of labels. It also turns out that the labeled pi-calculus is a conservative extension of the standard one. We contrast the existing fair testing with those that
naturally arise by imposing weak and strong fairness as defined by Costa and Stirling. This comparison provides the expressiveness of the various fair testing-based semantics and emphasizes the discriminating power of the one already proposed in the literature
Separation of synchronous and asynchronous communication via testing
No full textOne of the early results about the asynchronous π-calculus which significantly contributed to its popularity is the capability of encoding the output prefix of the (choiceless) pi-calculus in a natural and elegant way.
Encodings of this kind were proposed by Honda and Tokoro, by Nestmann and (independently) by Boudol.
We investigate whether the above encodings preserve De Nicola and Hennessy’s testing semantics. In this sense, it turns out that, under some general conditions, no encoding of output prefix is able to preserve the must testing. This negative result is due to (a) the non atomicity of the sequences of steps which are necessary in the asynchronous π-calculus to mimic synchronous communication, and (b) testing semantics’s sensitivity to divergence
Sanità sostenibile: servizi ubiquiti e personalizzati orientati al risparmio energetico
No full textIl concetto di sostenibilità ha dimostrato essere valido per un'ampia gamma di settori: tra questi vanno annoverati energia, agricoltura, foreste, edilizia, turismo e sanità che, benché eterogenei, risultano essere strettamente interconnessi tra loro in termini di sostenibilità. Ne consegue che politiche sostenibili orientate per ed applicate ad un settore specifico, possono influenzare in modo indiretto altri settori. Questo è particolarmente evidente nel caso della sanità e dell'energia. Un sistema sanitario è considerata sostenibile quando riesce a rispettare ed armonizzare a lungo termine vincoli di natura ecologica, ambientale, economica e sociale, perseguendo una politica di equilibrio sulle singole componenti del sistema
Uniformity in Multiscale Models: From Complex Automata to BioShape
No full textMany biological phenomena are inherently multiscale (MS) - i.e. they are characterised by interactions involving simultaneously different spatial and temporal scales. The needs of describing systems in a MS fashion and, more in general, MS problems across multiple scientific disciplines require a common modelling approach being able to (i) unify the common principles arising in general in MS scenarios (e.g. scale representation, scale separation and inter-scale interaction), (ii) support the effective combination of various single-scale models through well-defined scale coupling procedures, and consequently (iii) help to model and to simulate MS scenarios in a rigorous and systematic way.
Complex Automata (CxA) constitute a well-defined paradigm for multiscale modelling that goes towards the above mentioned characteristics.
BIOSHAPE, a 3D spatial geometric-based simulator, has been also defined as an independent modelling and simulation environment naturally able to represent, in the same model, different levels of multiscale systems. In this work we show that BIOSHAPE can be used to perform multiscale modelling and simulation using the same core ideas of the CxA approach
On Synchronous and Asynchronous Communication Paradigms
No full textThe pi-calculus, its asynchronous version and Boudol's mapping from the former language to the latter one are well-known mathematical objects in theoretical computer science. It is also well-known that the mapping is not fully-abstract w.r.t. most of the semantics defined over these two languages. In this paper we study and fix conditions on the existence of fully-abstract results for Boudol's mapping (and its variants). The testing theories \`a la De Nicola-Hennessy turned out to be very useful tools for such a purpose
Persistence and Testing Semantics in the Asynchronous Pi-Calculus
No full textIn [24] the authors studied the expressiveness of persistence in the asynchronous pi-calculus (Api) wrt weak barbed congruence. The study is incomplete because it ignores the issue of divergence. In this paper, we present an expressiveness study of persistence in the asynchronous pi-calculus (Api) wrt De Nicola and Hennessy’s testing scenario which is sensitive to divergence. Following [24], we consider Api and three sub-languages of it, each capturing one source of persistence: the persistent-input calculus (PIApi), the persistent-output calculus (POApi) and persistent calculus (PApi). In [24] the authors showed encodings
from Aπ into the semi-persistent calculi (i.e., POApi and PIApi) correct wrt weak barbed congruence. In this paper we prove that, under some general conditions, there cannot be an encoding from Api into a (semi)-persistent calculus preserving the must testing semantics
UBioLab: a web-LABoratory for Ubiquitous in-silico experiments
Get PDFThe huge and dynamic amount of bioinformatic resources (e.g., data and tools) available nowadays in Internet represents a big challenge for biologists –for what concerns their management
and visualization– and for bioinformaticians –for what concerns the possibility of rapidly creating and executing in-silico experiments involving resources and activities spread over the WWW hyperspace. Any framework aiming at integrating such resources
as in a physical laboratory has imperatively to tackle –and possibly to handle in a transparent
and uniform way– aspects concerning physical distribution, semantic heterogeneity,
co-existence of different computational paradigms and, as a consequence, of different invocation
interfaces (i.e., OGSA for Grid nodes, SOAP for Web Services, Java RMI for
Java objects, etc.). The framework UBioLab has been just designed and developed as a prototype following the above objective. Several architectural features –as those ones of
being fully Web-based and of combining domain ontologies, Semantic Web and workflow techniques– give evidence of an effort in such a direction.
The integration of a semantic knowledge management system for distributed (bioinformatic)
resources, a semantic-driven graphic environment for defining and monitoring ubiquitous
workflows and an intelligent agent-based technology for their distributed execution allows UBioLab to be a semantic guide for bioinformaticians and biologists providing (i) a flexible environment for visualizing, organizing and inferring any (semantics and computational) “type” of domain knowledge (e.g., resources and activities, expressed in a declarative form), (ii) a powerful engine for defining and storing semantic-driven ubiquitous in-silico experiments on the domain hyperspace, as well as (iii) a transparent, automatic and distributed environment for correct experiment executions
Sinergy: how semantics can improve early prevention of skin cancers.
No full textMelanoma is the major source of deaths related to skin cancer. The project “Sinergy”, in cooperation with Lega Italiana Lotta Tumori (L.I.L.T.) and ADiTech s.r.l., aims at realising a Cloud-based and semantic-driven framework for screening and analysis of skin lesions. The framework aims at being an ubiquitous laboratory in Cloud, equipped with semantic-driven tools for making analysis, defining/executing/sharing in-silico experiments, mining laboratory data and activities. The engine kernel, a multi-scale and multi-physics skin lesion ontology, not only makes intuitive any operation for non-expert users, but also improves diagnostic processes thanks to the possibility ofglobally reasoning on skin lesion variables relative to different biological scales (e.g., genetic, molecular, cellular, tissutal ones) and to not-biological ones (e.g., age, gender, location, geography, race)
ResourceHome: an RFID-based architecture and a flexible model for ambient intelligence
No full textIn this paper, we propose ResourceHome, an innovative RFID-based framework to locate objects in delimited environments and statically prevent/detect dangerous spatial/temporal configurations, i.e. configurations firing dangerous interactions of properties among objects.
Differently from most of RFID-based frameworks for spatial recognition, ResourceHome is equipped with an ontology-based knowledge model for describing two-dimensional environments
with fixed and mobile objects, as well as with a suitable First Order logic-based model for statically detecting spatial/temporal configurations of objects firing dangerous interactions
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