Modelling and analyzing adaptive self-assembling strategies with Maude

Building adaptive systems with predictable emergent behavior is a challenging task and it is becoming a critical need. The research community has accepted the challenge by introducing approaches of various nature: from software architectures, to programming paradigms, to analysis techniques. We recently proposed a conceptual framework for adaptation centered around the role of control data. In this paper we show that it can be naturally realized in a reflective logical language like Maude by using the Reflective Russian Dolls model. Moreover, we exploit this model to specify, validate and analyse a prominent example of adaptive system: robot swarms equipped with self-assembly strategies. The analysis exploits the statistical model checker PVeStA

Context-Aware Analysis of Data Sharing Agreements

A Data Sharing Agreement is an agreement among contracting parties regulating how they share data under certain contextual conditions. Upon the definition phase, where the parties negotiate the respective authorizations on data covered by the agreement, the resulting policy may be analysed in order to identify possible conflicts or incompatibilities among authorizations clauses. In this paper, we propose a formal framework for Data Sharing Agreement analysis. Our proposal is built on a process algebra formalism dealing with contextual data, encoded into the Maude engine to make it executable. The effectiveness of the analysis is shown through a sensitive data sharing test bed. Furthermore, we present an implementation of the analyser exposed as a Web Service built on top of Maude. The Web Service technology allows the modularity of the whole architecture with respect to the analysis tool

Implementing SOS with active objects: A case study of a multicore memory system

This paper describes the development of a parallel simulator of a multicore memory system from a model formalized as a structural operational semantics (SOS). Our implementation uses the Abstract Behavioral Specification (ABS) language, an executable, active object modelling language with a formal semantics, targeting distributed systems. We develop general design patterns in ABS for implementing SOS, and describe their application to the SOS model of multicore memory systems. We show how these patterns allow a formal correctness proof that the implementation simulates the formal operational model and discuss further parallelization and fairness of the simulator

A Conceptual Framework for Adapation

This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions

A Conceptual Framework for Adapation

This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions

A Conceptual Framework for Adapation

We present a white-box conceptual framework for adaptation. We called it CODA, for COntrol Data Adaptation, since it is based on the notion of control data. CODA promotes a neat separation between application and adaptation logic through a clear identification of the set of data that is relevant for the latter. The framework provides an original perspective from which we survey a representative set of approaches to adaptation ranging from programming languages and paradigms, to computational models and architectural solutions

From SOS to Asynchronously Communicating Actors

Structural Operational Semantics (SOS) provides a general format to describe a model as a transition system with very powerful synchronization mechanisms. Actor systems are distributed, asynchronously communicating units of computation with encapsulated state, with much weaker means of synchronizing between actors. In this paper, we discuss an implementation of a SOS model using actors in the object-oriented actor language ABS and how to argue that global properties about the model are inherited from the SOS level to the actor implementation. The work stems from a case study modelling the memory system of a cache-coherent multicore architecture

Towards Safer Information Sharing in the Cloud

Web interactions usually require the exchange of personal and confidential information for a variety of purposes, including enabling business transactions and the provisioning of services. A key issue affecting these interactions is the lack of trust and control on how data is going to be used and processed by the entities that receive it. In the traditional world, this problem is addressed by using contractual agreements, those are signed by the involved parties, and law enforcement. This could be done electronically as well but, in ad- dition to the trust issue, there is currently a major gap between the definition of legal contracts regulat- ing the sharing of data, and the software infrastructure required to support and enforce them. How to enable organisations to provide more automation in this pro- cess? How to ensure that legal contracts can be actually enforced by the underlying IT infrastructure? How to enable end-users to express their preferences and con- straints within these contracts? This article describes our R&D work to make progress towards addressing this gap via the usage of electronic Data Sharing Agree- ments (e-DSA). The aim is to share our vision, discuss the involved challenges and stimulate further research and development in this space. We specifically focus on a cloud scenario because it provides a rich set of?use cases involving interactions and information shar- ing among multiple stakeholders, including users and service providers.?

Definition of Data Sharing Agreements (The case of Spanish Data Protection Law)

Electronic sharing of data among different parties, includ- ing groups of organizations and/or individuals, while protecting their legitimate rights on these data, is a key both for business and societal transactions. However, data sharing clauses are usually specified in legal documents that are far from being amenable of automated processing by the electronic platform that should enforce them. Furthermore, different parties usually pursue different interests. This may lead to conflicts that need to be solved for the agreements to succeed. Addressing this prob- lem, in this paper we i) discuss a proposal for the definition of a machine processable electronic data sharing multilateral contract (e-DSA); ii) re- call a controlled natural language (CNL4DSA) developed for expressing e-DSA clauses, in particular, authorizations and obligations policies on data; iii) instantiate a resolution process that can solve potential con- flicts posed by different stakeholders? clauses, e.g., legal, organizational, and end-users? clauses, according to specific criteria. We illustrate our approach on a realistic e-Health scenario derived from one described by a Spanish medical institution. The main novelty of this paper are the ref- erence to the Spanish Data Protection Law (S)DPL as the basic source of policies regulating data exchange and the idea of a multi-step e-DSA definition phase that incrementally increases the contract granularity. To the best of our knowledge, this is one of the first attempts to investi- gate how a real DPL can be translated into privacy rules electronically manageable by a devoted e-DSA-based infrastructure.?