38,122 research outputs found

    To boldly go:an occam-π mission to engineer emergence

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    Future systems will be too complex to design and implement explicitly. Instead, we will have to learn to engineer complex behaviours indirectly: through the discovery and application of local rules of behaviour, applied to simple process components, from which desired behaviours predictably emerge through dynamic interactions between massive numbers of instances. This paper describes a process-oriented architecture for fine-grained concurrent systems that enables experiments with such indirect engineering. Examples are presented showing the differing complex behaviours that can arise from minor (non-linear) adjustments to low-level parameters, the difficulties in suppressing the emergence of unwanted (bad) behaviour, the unexpected relationships between apparently unrelated physical phenomena (shown up by their separate emergence from the same primordial process swamp) and the ability to explore and engineer completely new physics (such as force fields) by their emergence from low-level process interactions whose mechanisms can only be imagined, but not built, at the current time

    Implementing a distributed mobile calculus using the IMC framework

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    In the last decade, many calculi for modelling distributed mobile code have been proposed. To assess their merits and encourage use, implementations of the calculi have often been proposed. These implementations usually consist of a limited part dealing with mechanisms that are specific of the proposed calculus and of a significantly larger part handling recurrent mechanisms that are common to many calculi. Nevertheless, also the "classic" parts are often re-implemented from scratch. In this paper we show how to implement a well established representative of the family of mobile calculi, the distributed [pi]-calculus, by using a Java middleware (called IMC - Implementing Mobile Calculi) where recurrent mechanisms of distributed and mobile systems are already implemented. By means of the case study, we illustrate a methodology to accelerate the development of prototype implementations while concentrating only on the features that are specific of the calculus under consideration and relying on the common framework for all the recurrent mechanisms like network connections, code mobility, name handling, etc

    A Flexible and Modular Framework for Implementing Infrastructures for Global Computing

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    We present a Java software framework for building infrastructures to support the development of applications for systems where mobility and network awareness are key issues. The framework is particularly useful to develop run-time support for languages oriented towards global computing. It enables platform designers to customize communication protocols and network architectures and guarantees transparency of name management and code mobility in distributed environments. The key features are illustrated by means of a couple of simple case studies

    Towards a Formal Framework for Mobile, Service-Oriented Sensor-Actuator Networks

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    Service-oriented sensor-actuator networks (SOSANETs) are deployed in health-critical applications like patient monitoring and have to fulfill strong safety requirements. However, a framework for the rigorous formal modeling and analysis of SOSANETs does not exist. In particular, there is currently no support for the verification of correct network behavior after node failure or loss/addition of communication links. To overcome this problem, we propose a formal framework for SOSANETs. The main idea is to base our framework on the \pi-calculus, a formally defined, compositional and well-established formalism. We choose KLAIM, an existing formal language based on the \pi-calculus as the foundation for our framework. With that, we are able to formally model SOSANETs with possible topology changes and network failures. This provides the basis for our future work on prediction, analysis and verification of the network behavior of these systems. Furthermore, we illustrate the real-life applicability of this approach by modeling and extending a use case scenario from the medical domain.Comment: In Proceedings FESCA 2013, arXiv:1302.478

    The prevalence, communicability and co-occurrence of inverted hallucinations: an overlooked global public health concern

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    While scientific understanding concerning the role of biological pathogenic agents in the transmission of communicable diseases has increased markedly in recent decades, the possibility of a psychological pathogenic agent that underlies the transmission of a number of key global public health concerns has largely been overlooked. The present paper identifies inverted hallucinations as a novel category of hallucination that not only reflect a key public health concern in their own right, but also appear to play an active role in the gradual transmission of diseases traditionally deemed to be non-communicable, such as mental health problems, obesity, and social media addiction. More specifically, the present paper delineates the assumptions and indicative empirical support underlying inverted hallucination theory as well as the characteristic features, functional consequences, prevalence, communicability, and co-occurrence of inverted hallucinations in the general population. Inverted hallucinations appear to be both globally prevalent and communicable, and are estimated to affect the average person on at least an occasional basis. Inverted hallucinations cause individuals to succumb to states of mind wandering that distorts their perception of what is happening in the present moment and increases their susceptibility to other deleterious health conditions. Moreover, inverted hallucinations appear to reflect a key overlooked public health need that not only stunt human potential and quality of life but also pose a risk to the wellbeing of the population globally.N

    Locating Agents in RFID Architectures

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    The use of software agents can create an “intelligent” interface between users’ preferences and the back‐end systems. Agents are now able to interact and communicate with each other, forming a virtual community and feeding back the user with suggestions. Innovative systems related to Asset Tracking, Inventory and Shelving architectures are more often involving advanced communication techniques (e.g., RFID); these systems are responsible for user authentication and objects verification. RFID systems could have jamming situations where many objects are moving at the same time and in the same direction. Moreover, other disadvantages have also been observed, such as hindering further implementations, privacy and security issues problems, in addition to the system’s disruptive behavior in case of crowd checkouts (e.g., Supermarket and Airports). Addressing these disadvantages, this paper proposes a possible integration between a Multi‐Agent framework and an RFID‐based application (back‐end). This integration would allow objects (such as passports or goods) with RFID tags to better check‐out through airports or supermarket gates that contain RFID‐readers

    Name-passing calculi and crypto-primitives: A survey

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    The paper surveys the literature on high-level name-passing process calculi, and their extensions with cryptographic primitives. The survey is by no means exhaustive, for essentially two reasons. First, in trying to provide a coherent presentation of different ideas and techniques, one inevitably ends up leaving out the approaches that do not fit the intended roadmap. Secondly, the literature on the subject has been growing at very high rate over the years. As a consequence, we decided to concentrate on few papers that introduce the main ideas, in the hope that discussing them in some detail will provide sufficient insight for further reading
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