2,405 research outputs found
A Flexible and Modular Framework for Implementing Infrastructures for Global Computing
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
Orchestrating Tuple-based Languages
The World Wide Web can be thought of as a global computing architecture supporting the deployment of distributed networked applications. Currently, such applications can be programmed by resorting mainly to two distinct paradigms: one devised for orchestrating distributed services, and the other designed for coordinating distributed (possibly mobile) agents. In this paper, the issue of designing a pro-
gramming language aiming at reconciling orchestration and coordination is investigated. Taking as starting point the orchestration calculus Orc and the tuple-based coordination language Klaim, a new formalism is introduced combining concepts and primitives of the original calculi.
To demonstrate feasibility and effectiveness of the proposed approach, a prototype implementation of the new formalism is described and it is then used to tackle a case study dealing with a simplified but realistic electronic marketplace, where a number of on-line stores allow client
applications to access information about their goods and to place orders
Comparativism then and now
This is the author accepted manuscript. The final version is available from Brill via the DOI in this record.This chapter examines the relationship between classics and anthropology as relates to cross-cultural comparison. Despite an ancient pedigree, scholarly comparison of the classical cultures to one another (or to other cultures) has remained circumscribed. Christian Gottlob Heyne (1729â1812), who advocated understanding "the spirit of that time, its representations and relations and all its contemporary connections to things", has been all but forgotten. German Altertumswissenschaft rejected the "savage" comparativism of James George Frazer, William Warde Fowler, William F. Jackson Knight, and Herbert Jennings Rose as haphazard and superficial. This history probably explains the lack of any real comparative method in even the most "anthropological" classical scholarship in recent decades: J.-P. Vernant and Florence Dupont, for instance, noticeably eschew that "comparative sociology" identified by Radcliffe-Brown as the essence of anthropologyânot to mention large-scale intercultural comparisons along the lines of LĂ©vi-Strauss' Mythologiques. Some scholars, however, purposefully juxtapose Roman culture and Greek culture, with the possibility then of comparing these cultures with others both ancient and modern. Rather than predetermine the meaning of any specific cultural configuration by placing it alongside supposedly analogous representations, this "new comparativism" actively constructs meaning through juxtapositions and comparisons of what is different between cultures (see Detienne 2007; 2008). To illustrate this approach, this chapter compares metaphorical linguistic expressions in Greek and Latin, arguing that it is possible to tease out significant differences not only in how speakers of these languages conceived of certain experiences but also in their attitudes and values towardsâand thus behaviours and practices in respect ofâthose experiences. Here, metaphors of "making a mistake" are discussed to suggest that Latin's "wandering" metaphor has not only widespread semantic effects but also identifiable effects on culture more broadly conceived
Implementing Session Centered Calculi
Recently, specific attention has been devoted to the development of service oriented process calculi. Besides the foundational aspects, it is also interesting to have prototype implementations for them in order to assess usability and to minimize the gap between theory and practice. Typically, these implementations are done in Java taking advantage of its mechanisms supporting network applications. However, most of the recurrent features of service oriented applications are re-implemented from scratch. In this paper we show how to implement a service oriented calculus, CaSPiS (Calculus of Services with Pipelines and Sessions) using the Java framework IMC, where recurrent mechanisms for network applications are already provided. By using the session oriented and pattern matching communication mechanisms provided by IMC, it is relatively simple to implement in Java all CaSPiS abstractions and thus to easily write the implementation in Java of a CaSPiS process
Surface Effects on the Mechanical Elongation of AuCu Nanowires: De-alloying and the Formation of Mixed Suspended Atomic Chains
We report here an atomistic study of the mechanical deformation of AuxCu(1-x)
atomic-size wires (NWs) by means of high resolution transmission electron
microscopy (HRTEM) experiments. Molecular dynamics simulations were also
carried out in order to obtain deeper insights on the dynamical properties of
stretched NWs. The mechanical properties are significantly dependent on the
chemical composition that evolves in time at the junction; some structures
exhibit a remarkable de-alloying behavior. Also, our results represent the
first experimental realization of mixed linear atomic chains (LACs) among
transition and noble metals; in particular, surface energies induce chemical
gradients on NW surfaces that can be exploited to control the relative LAC
compositions (different number of gold and copper atoms). The implications of
these results for nanocatalysis and spin transport of one-atom-thick metal
wires are addressed.Comment: Accepted to Journal of Applied Physics (JAP
Network-aware Evaluation Environment for Reputation Systems
Parties of reputation systems rate each other and use ratings to compute reputation scores that drive their interactions. When deciding which reputation model to deploy in a network environment, it is important to find the
most suitable model and to determine its right initial configuration. This calls for an engineering approach for describing, implementing and evaluating reputation
systems while taking into account specific aspects of both the reputation systems and the networked environment where they will run. We present a software tool (NEVER) for network-aware evaluation of reputation systems and their rapid prototyping through experiments performed according to user-specified parameters. To demonstrate effectiveness of NEVER, we analyse reputation models based on the beta distribution and the maximum likelihood estimation
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