130,569 research outputs found

    A Methodology for Agent-Oriented Analysis and Design

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    This paper presents a methodology for agent-oriented analysis and design. The methodology is general, in that it is applicable to a wide range of multi-agent systems, and comprehensive, in that it deals with both the macro-level (societal) and the micro-level (agent) aspects of systems. The methodology is founded on the view of a system as a computational organisation consisting of various interacting roles. We illustrate the methodology through a case study (an agent-based business process management system)

    The dMARS Architechure: A Specification of the Distributed Multi-Agent Reasoning System

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    The Procedural Reasoning System (PRS) is the best established agent architecture currently available. It has been deployed in many major industrial applications, ranging from fault diagnosis on the space shuttle to air traffic management and business process control. The theory of PRS-like systems has also been widely studied: within the intelligent agents research community, the belief-desire-intention (BDI) model of practical reasoning that underpins PRS is arguably the dominant force in the theoretical foundations of rational agency. Despite the interest in PRS and BDI agents, no complete attempt has yet been made to precisely specify the behaviour of real PRS systems. This has led to the development of a range of systems that claim to conform to the PRS model, but which differ from it in many important respects. Our aim in this paper is to rectify this omission. We provide an abstract formal model of an idealised dMARS system (the most recent implementation of the PRS architecture), which precisely defines the key data structures present within the architecture and the operations that manipulate these structures. We focus in particular on dMARS plans, since these are the key tool for programming dMARS agents. The specification we present will enable other implementations of PRS to be easily developed, and will serve as a benchmark against which future architectural enhancements can be evaluated

    Interaction Protocols in Agentis

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    Agentis is a framework for building interactive multiagent applications which is based upon a model of agent interaction whose key elements are services and tasks. Central to the operation of the system is the set of protocols that permit reliable, concurrent request and provision of services and tasks from and to agents, using an underlying asynchronous point-to-point messaging infrastructure. In this paper we focus on this aspect of the Agentis system and provide a detailed description of these protocols, together with a formal specification in Z. The specification can be seen as part of a more complete formal specification of the entire system, which provides an integrated and coherent way of describing the system at different levels. In so specifying the Agentis protocols, however, we also provide some general guidelines which may be applied to the specification of other protocols for agent interaction. 1 Introduction The Agentis system is a framework for building interactive appl..

    Depositional age, provenance and metamorphic age of metasedimentary rocks from southern Madagascar

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    Southern Madagascar is the core of a >1million km 2 Gondwanan metasedimentary belt that forms much of the southern East African Orogen of eastern Africa, Madagascar, southern India and Sri Lanka. Here the Vohibory Series yielded U-Pb isotopic data from detrital zircon cores that indicate that it was deposited in the latest Tonian to late Cryogenian (between ~900 and 640Ma). The deposition of the Graphite and Androyen Series protoliths is poorly constrained to between the late Palaeoproterozoic and the Cambrian (~1830-530Ma). The Vohibory Series protoliths were sourced from very restricted-aged sources with a maximum age range between 910 and 760Ma. The Androyen and Graphite Series protoliths were sourced from Palaeoproterozoic rocks ranging in age between 2300 and 1800Ma. The best evidence of the timing of metamorphism in the Vohibory Series is a weighted mean 206Pb/ 238U age of 642±8Ma from 3 analyses of zircon from sample M03-01. A considerably younger 206Pb/ 238U metamorphic age of 531±7Ma is produced from 10 analyses of zircon from sample M03-28 in the Androyen Series. This ~110Ma difference in age is correlated with the early East African Orogeny affecting the west of Madagascar along with its type area in East Africa, whereas the Cambrian Malagasy Orogeny affected the east of Madagascar and southern India during the final suturing of the Mozambique Ocean. © 2010 International Association for Gondwana Research.Alan S. Collins, Peter D. Kinny and Théodore Razakamanan

    MeSH term explosion and author rank improve expert recommendations

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    Information overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Neoproterozoic orogeny along the margin of Rodinia: Valhalla orogen, North Atlantic

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    Latest Mesoproterozoic to mid-Neoproterozoic (1030–710 Ma) sedimentation and orogenic activity that developed on the northeast Laurentian substrate around the North Atlantic borderlands and is currently exposed in Scotland, Shetland, East Greenland, Svalbard, and Norway, is herein defined as the Valhalla orogen. The site for the orogen was initiated by ~95° of clockwise rotation of Baltica with respect to Laurentia at the end of the Mesoproterozoic. This created a triangular ocean basin, the Asgard Sea, which received orogenic detritus from the Grenville-Sveconorwegian-Sunsas orogen. Sedimentary successions within the orogen accumulated during two cycles at 1030–980 Ma and 910–870 Ma, with each cycle terminated and the successions stabilized during tectonothermal episodes involving crustal thickening and igneous activity, some of calc-alkaline affinity, associated with the Renlandian (980–910 Ma) and Knoydartian (830–710 Ma) orogenic events. The Valhalla orogen represents an exterior accretionary orogen that developed along the margin of Laurentia and the Asgard Sea. The early stages of the Valhalla orogen are coeval with the final stages of the Grenville-Sveconorwegian-Sunsas orogen to the south, but are tectonically discrete; they constitute part of an exterior orogen that is entirely distinct from the interior orogen formed between collision of Laurentia, Baltica, and Amazonia.Peter A. Cawood, Rob Strachan, Kathryn Cutts, Peter D. Kinny, Martin Hand and Sergei Pisarevsk

    "Closing the R&D Gap, Evaluating the Sources of R&D Spending"

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    Both spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.

    A. D. Fricke, author

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    Black and white photograph of author, A. D. Fricke
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