1,217 research outputs found
Composing Gradients for a Context-Aware Navigation of Users in a Smart-City
No full textRecent works suggested the use of self-organising spatial patterns, enacted as computational fields, to the problem of steering users towards their desired destination in complex environments. In a rich and open scenarios, various contextual services can enter the system providing additional information that can be exploited to guide users by suggesting paths that more likely satisfy their preferences. This can be done composing new information with the steering services already available in the system. Since the type and number of new services available can vary over time, such compositions must be identified dynamically, in an autonomous, spontaneous and unsupervised way. Moreover, in order to avoid the system to be overflooded by services that do not match any user preferences, a mechanism for identifying useless compositions and for removing them should be provided. In this paper we investigate this problem and propose a self-composition approach envisioned to support the composition of new services together with basic services for crowd steering, such that, depending on the actual (spatial/temporal) context in which the composition is deployed, users are steered across the path that better fit their preferences
Proceedings of FOCLASA 2005, 4th International Workshop on Foundations of Coordination Languages and Software Architectures
No full textA quarter-century of The Knowledge Engineering Review
No full textWe introduce the Special Issue of the journal created to celebrate 25 years of continuous publication. With this issue The Knowledge Engineering Review commences its 26th year of publication. To
mark a quarter-century of continuous publication, we decided to devote an issue of the journal to several non-technical papers exploring the past, the present, and the future of knowledge
engineering, intelligent systems, and artificial intelligence
A Self-Organising Infrastructure for Chemical-Semantic Coordination: Experiments in TuCSoN
No full textRecent works proposed the adoption of a nature-inspired approach of chemistry for implementing service architectures suitable for pervasive applications. In particular, Viroli and Casadei propose a chemical-semantic tuple-space model where coordination of data, devices and software agents — representing the services of the pervasive computing application — are reified into proper tuples managed by the coordination infrastructure. Service coordination is enacted by chemical-like reactions that semantically match those tuples accordingly enacting the desired interaction patterns (composition, aggregation, competition, con- textualisation, diffusion and decay). After showing and motivating the proposed coordination approach for situated, adaptive, and diversity-accomodating pervasive computing systems, in this paper we outline how it is possible to concretise the approach on the TuCSoN coordination infrastructure, which can been suitably enhanced with modules supporting fuzzy semantic-coordination and execution engine for chemical-inspired coordination laws
Using Probabilistic Model Checking and Simulation for Designing Self-Organizing Systems
No full textSelf-organization is a feasible metaphor for dealing with the growing complexity of today's software systems. Self-organization makes desired global system's behavior appear as an emergent property from component local interactions. The corresponding dynamics is usually non-linear so that the adoption of stochastic simulation and probabilistic model checking becomes essential in the early design stage. In this paper, as a reference example, a possible application of such techniques is shown on a problem called collective sort, whose emergent properties were analyzed by relying on the PRISM probabilistic model checker
Integrating Java and Prolog through generic methods and type inference
No full textP@J is a framework, based on the tuProlog open-source engine, allowing Prolog code to be used as possible implementation of a Java method: Java annotations are used for specifying all the necessary information to fill the Java-Prolog gap. This framework is useful to inject a declarative, logic-based paradigm into mainstream object-oriented programming, so as to easily code functionalities related to automatic reasoning, adaptivity, and conciseness in expressing algorithms.
In this paper, an extension of P@J is presented which improves the invocation technique for such Prolog-implemented methods. Java type inference of generic method calls is intensively used to automatically infer all the necessary paradigm mismatch information: this results in an elegant and concise invocation style, which further reduces the gap between Prolog goal satisfaction and Java method invocation. This new approach inspires some interesting applications: we show examples related to the implementation of abstract data types and parsers for context-free
grammars
Prototyping A&A ReSpecT in Maude
No full textAbstractThe formal modelling of programming languages has always been a challenging activity due to the gap occurring between formal definition and actual implementation. On the other hand, the Maude rewriting language has already proven to be a suitable tool to bridge the gap between theory and practice when implementing the operational semantics of programming languages. In particular, Maude has been exploited to model languages belonging to different paradigms and levels of abstraction, leading to specifications that represent de facto executable prototypes of such languages.In this paper we focus on A&A ReSpecT, a coordination language based on the agents and artifacts (A&A) meta-model, and exploit Maude to generate an execution machine for A&A ReSpecT programs, acting as an implementation of its operational semantics
Prototyping Concurrent Systems with Agents and Artifacts: Framework and Core Calculus
No full textAbstractMore and more aspects of concurrency and concurrent programming are becoming part of mainstream programming and software engineering, due to several factors such as the widespread availability of multi-core / parallel architectures and Internet-based systems. Besides the typical fine-grained support currently provided, however, we seek in this paper for an higher-level approach. We present simpA, a library-based extension of Java which provides programmers with agent and artifact abstractions on top of the basic OO layer, as a means to organise and structure concurrent applications. To pave the way towards identifying a true language extension for simpA, we define a core calculus of agents and artifacts, by suitabling mixing techniques coming from object-orientation and concurrency theory
Preface
No full textThis issue contains extended versions of selected papers from the 6th International Workshop on the Foundations of
Coordination Languages and Software Architectures (FOCLASA’07)
Simulating Emergent Properties of Coordination in Maude: the Collective Sort Case
No full textAbstractRecent coordination languages and models are moving towards the application of techniques coming from the research context of complex systems: adaptivity and self-organization are exploited in order to tackle the openness, dynamism and unpredictability of today's distributed systems. In this area, systems are to be described using stochastic models, and simulation is a valuable tool both for analysis and design. Accordingly, in this work we focused on modelling and simulating emergent properties of coordination techniques.We first develop a framework acting as a general-purpose engine for simulating stochastic transition systems, built as a library for the Maude term rewriting system. We then evaluate this tool to a coordination problem called collective sort, where autonomous agents move tuples across different tuple spaces according to local criteria, and resulting in the emergence of the complete clustering property
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