Enhancing the performance of Decoupled Software Pipeline through Backward Slicing

The rapidly increasing number of cores available in multicore processors does not necessarily lead directly to a commensurate increase in performance: programs written in conventional languages, such as C, need careful restructuring, preferably automatically, before the benefits can be observed in improved run-times. Even then, much depends upon the intrinsic capacity of the original program for concurrent execution. The subject of this paper is the performance gains from the combined effect of the complementary techniques of the Decoupled Software Pipeline (DSWP) and (backward) slicing. DSWP extracts threadlevel parallelism from the body of a loop by breaking it into stages which are then executed pipeline style: in effect cutting across the control chain. Slicing, on the other hand, cuts the program along the control chain, teasing out finer threads that depend on different variables (or locations). parts that depend on different variables. The main contribution of this paper is to demonstrate that the application of DSWP, followed by slicing offers notable improvements over DSWP alone, especially when there is a loop-carried dependence that prevents the application of the simpler DOALL optimization. Experimental results show an improvement of a factor of ?1.6 for DSWP + slicing over DSWP alone and a factor of ?2.4 for DSWP + slicing over the original sequential code

Normative Practical Reasoning via Argumentation and Dialogue

Postprin

Systemic approaches to incident analysis in aviation: comparison of STAMP, Agent-Based Modelling and Institutions

The rapid development and increasing complexity of modern socio-technical systems suggest an urgent need for systemic safety analysis approaches because traditional linear models cannot cope with this complexity. In the aviation safety literature, among systemic accident and incident analysis methods, Systems Theoretic Accident Modelling and Processes (STAMP) and Agent-based modelling (ABM) are the most cited ones. STAMP is a qualitative analysis approach known for its thoroughness and comprehensiveness. Computational ABM approach is a formal quantitative method which proved to be suitable for modelling complex flexible systems. In addition, from a legal point of view, formal systemic institutional modelling potentially provides an interesting contribution to accident and incident analysis. The current work compares three systemic modelling approaches: STAMP, ABM and institutional modelling applied to a case study in an aviation domain

Fine-grained access control via policy-carrying data

W. W. Vasconcelos acknowledges the support of the Engineering and Physical Sciences Research Council (EPSRC, UK) within the research project “Scrutable Autonomous Systems” (SAsSY, http://www.scrutable-systems.org, Grant ref. EP/J012084/1). Also in: Journal ACM Transactions on Reconfigurable Technology and Systems (TRETS) - Special Section on FCCM 2016 and Regular Papers TRETS Homepage archive Volume 11 Issue 1, March 2018 Article No. 31 ACM New York, NY, USAPeer reviewedPostprin

Sendero: An Extended, Agent-Based Implementation of Kauffman's NKCS Model

The idea of agents exploring a fitness landscape in which they seek to move from 'fitness valleys' to higher 'fitness peaks' has been presented by Kauffman in the NK and NKCS models. The NK model addresses single species while the NKCS extension illustrates coevolving species on coupled fitness landscapes. We describe an agent-based simulation (Sendero), built in Repast, of the NK and NKCS models. The results from Sendero are validated against Kauffman's findings for the NK and NKCS models. We also describe extensions to the basic model, including population dynamics and communication networks for NK, and directed graphs and variable change rates for NKCS. The Sendero software is available as open source under the BSD licence and is thus available for download and extension by the research community.Coevolution, Agent-Based Modelling, NK, NKCS, Fitness Landscape

LOG-IDEAH: ASP for Architectonic Asset Preservation

To preserve our cultural heritage, it is important to preserve our architectonic assets, comprising buildings, their decorations and the spaces they encompass. In some geographical areas, occasional natural disasters, specifically earthquakes, damage these cultural assets. Perpetuate is a European Union funded project aimed at establishing a methodology for the classification of the damage to these buildings, expressed as "collapse mechanisms". Structural engineering research has identified 17 different collapse mechanisms for masonry buildings damaged by earthquakes. Following established structural engineering practice, paper-based decisions trees have been specified to encode the recognition process for each of the various collapse mechanisms. In this paper, we report on how answer set programming has been applied to the construction of a machine-processable representation of these collapse mechanisms as an alternative for these decision-trees and their subsequent verification and application to building records from L\u27Aquila, Algiers and Rhodes. As a result, we advocate that structural engineers do not require the time-consuming and error-prone method of decisions trees, but can instead specify the properties of collapse mechanisms directly as an answer set program

The Challenge of Artificial Socio-Cognitive Systems

This paper is an invitation to carry out science and engineering for a class of socio-technical systems where individuals ¿ who may be human or artificial entities ¿ engage in purposeful collective interactions within a shared web-mediated social space. We put forward a characterisation of these systems and introduce some conceptual distinctions that may help to plot the work ahead. In particular, we propose a tripartite view that highlights the interplay between the institutional models that prescribe the behaviour of participants, the corre- sponding implementation of these prescriptions and the actual performance of the system. Building on this tripartite view we explore the problem of developing a conceptual framework for modelling this type of systems and how that framework can be supported by technological artefacts that implement the resulting models. The last section of this position paper is a list of challenges that we believe are worth facing. This work draws upon the contributions that the MAS community has made to the understanding and realization of the concepts of coordination, norms and institutions from an organisational perspective.The authors wish to acknowledge the support of SINTELNET (FET Open Coordinated Action FP7-ICT-2009-C Project No. 286370) in the writing of this paper.Peer Reviewe