87 research outputs found

    An Agent-Based Model of Collective Emotions in Online Communities

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    We develop a agent-based framework to model the emergence of collective emotions, which is applied to online communities. Agents individual emotions are described by their valence and arousal. Using the concept of Brownian agents, these variables change according to a stochastic dynamics, which also considers the feedback from online communication. Agents generate emotional information, which is stored and distributed in a field modeling the online medium. This field affects the emotional states of agents in a non-linear manner. We derive conditions for the emergence of collective emotions, observable in a bimodal valence distribution. Dependent on a saturated or a superlinear feedback between the information field and the agent's arousal, we further identify scenarios where collective emotions only appear once or in a repeated manner. The analytical results are illustrated by agent-based computer simulations. Our framework provides testable hypotheses about the emergence of collective emotions, which can be verified by data from online communities.Comment: European Physical Journal B (in press), version 2 with extended introduction, clarification

    Lead Speciation in the Dusts Emitted from Non-Ferrous Metallurgy Processes

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    The paper presents results for the speciation analysis of lead in dusts derived from dedusting of technological gasses from metallurgical processes of non-ferrous metals with different elementary content, made in accordance with two equal sequential extractions. Analytical procedure A provided possibilities for determination of fraction of Pb2+, metallic lead and fraction containing mainly lead sulfides. The second procedure (procedure B) was sequential extraction in accordance with Tessier. The results obtained in accordance with procedure A indicate that, regardless of the dust origin, the dominant group of Pb compounds is composed of lead salts which are soluble under alkaline conditions or lead compounds that form plumbites in the reaction with NaOH

    A web-based Toolbox to support the systemic eco-efficiency assessment in water use systems

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    The eco-efficiency assessment of a water use system at the meso level, as well as the estimation of the anticipated eco-efficiency improvements as a result of innovative practices/technologies, is a conceptually and methodologically challenging issue. A systemic approach is required to capture the complexity of all interrelated aspects and the interactions among the heterogeneous actors involved in the system. This involves mapping the behaviour of the system into representative models, structuring the analysis in easy to understand procedures and developing versatile software tools for supporting the analysis. This paper presents a web-integrated suite of tools and resources (EcoWater Toolbox) for assessing eco-efficiency improvements from innovative technologies in water use systems. Equipped with a continuously updated inventory of currently available technological innovations as well as a repository of eco-efficiency indicators and their evaluation rules, the EcoWater Toolbox supports a comprehensive four-step eco-efficiency assessment of a water use system: (1) allows the users to frame the case study by defining system boundaries, describing the water supply chain and value chains and including all the actors; (2) helps the users to establish a baseline eco-efficiency assessment, using the integrated modelling tools; (3) supports the users in identifying both sector-specific and system-wide technologies and practices to suit their situation, through the integrated technology inventory; and (4) enables the users to assess innovative technology solutions by developing predictive technology scenarios and comparing these with baseline results. At the core of the Toolbox are two modelling tools, which combine both economic and environmental viewpoints into a single modelling framework. The “Systemic Environmental Analysis Tool” (SEAT) assists in building a representation of the physical system, its processes and interactions and forms the basis for evaluating the environmental performance of the system. The “Economic Value chain Analysis Tool” (EVAT) addresses the value chain and focuses on the economic component of the eco-efficiency. Both tools provide a graphical model construction interface that is implemented in client-side and incorporate advanced features such as model scripting. The methodology adopted and the operational aspects of the EcoWater Toolbox are presented and demonstrated through the assessment of the eco-efficiency performance associated with the water value chain in the case of a milk production unit of a dairy industry

    A Place to Rest Your (Burnt) Bones? Mortuary Houses in Early Anglo-Saxon England

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Archaeological Journal on 5th October 2017, available online: doi: 10.1080/00665983.2017.1366704This article presents a fresh interpretation of square and rectangular mortuary structures found in association with deposits of cremated material and cremation burials in a range of early Anglo-Saxon (fifth-/sixth-century AD) cemeteries across southern and eastern England. Responding to a recent argument that they could be traces of pyre structures, a range of ethnographic analogies are drawn upon, and the full-range of archaeological evidence is synthesized, to re-affirm and extend their interpretation as unburned mortuary structures. Three interleaving significances are proposed: (i) demarcating the burial place of specific individuals or groups from the rest of the cemetery population, (ii) operating as ‘columbaria’ for the above-ground storage of the cremated dead (i.e. not just to demarcate cremation burials), and (iii) providing key nodes of commemoration between funerals as the structures were built, used, repaired and eventually decayed within cemeteries. The article proposes that timber ‘mortuary houses’ reveal that groups in early Anglo-Saxon England perceived their cemeteries in relation to contemporary settlement architectures, with some groups constructing and maintaining miniaturized canopied buildings to store and display the cremated remains of the dead
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