Agent Based Models of Competition and Collaboration

Swarm intelligence is a popular paradigm for algorithm design. Frequently drawing inspiration from natural systems, it assigns simple rules to a set of agents with the aim that, through local interactions, they collectively solve some global problem. Current variants of a popular swarm based optimization algorithm, particle swarm optimization (PSO), are investigated with a focus on premature convergence. A novel variant, dispersive PSO, is proposed to address this problem and is shown to lead to increased robustness and performance compared to current PSO algorithms. A nature inspired decentralised multi-agent algorithm is proposed to solve a constrained problem of distributed task allocation. Agents must collect and process the mail batches, without global knowledge of their environment or communication between agents. New rules for specialisation are proposed and are shown to exhibit improved eciency and exibility compared to existing ones. These new rules are compared with a market based approach to agent control. The eciency (average number of tasks performed), the exibility (ability to react to changes in the environment), and the sensitivity to load (ability to cope with differing demands) are investigated in both static and dynamic environments. A hybrid algorithm combining both approaches, is shown to exhibit improved eciency and robustness. Evolutionary algorithms are employed, both to optimize parameters and to allow the various rules to evolve and compete. We also observe extinction and speciation. In order to interpret algorithm performance we analyse the causes of eciency loss, derive theoretical upper bounds for the eciency, as well as a complete theoretical description of a non-trivial case, and compare these with the experimental results. Motivated by this work we introduce agent "memory" (the possibility for agents to develop preferences for certain cities) and show that not only does it lead to emergent cooperation between agents, but also to a signicant increase in efficiency

Techno-economic and uncertainty analysis of Biomass to Liquid (BTL) systems for transport fuel production

This work examines the technical and economic feasibility of Biomass-To-Liquid (BTL) processes for the manufacture of liquid hydrocarbon fuels. Six BTL systems are modelled and evaluated which are based on pressurised oxygen gasification of woody biomass, and specifically on circulating fluidised bed and entrained flow gasification systems. Three fuel synthesis technologies are considered: Fischer-Tropsch synthesis, methanol conversion followed by Methanol to Gasoline (MTG) and the Topsoe Integrated Gasoline (TIGAS) synthesis. Published modelling studies of BTL systems based on gasification have only used deterministic estimates of fuel production costs to assess economic viability without accounting for uncertainties of their model parameters. Unlike other studies, the present techno-economic assessment examines and quantifies the effect of uncertainty of key parameters on the fuel production costs. The results of this analysis show that there is a realistic chance (8–14%) of concepts based on Fischer-Tropsch synthesis meeting the cost of conventional fuels; that this probability could be increased to 50% with moderate tax incentives (an 8% reduction in the tax rate); but that deterministic estimates may be systematically underestimating likely production costs. The overall energy efficiency and production costs of the BTL designs evaluated range from 37.9% to 47.6% LHV and €17.88–25.41 per GJ of produced fuels, respectively. The BTL concept with the lowest production costs incorporates CFB gasification and FT synthesis. The model deterministic estimates of production costs of this design indicate that a BTL process is not yet competitive with conventional refineries since the biofuel production costs are approximately 8% higher than current market prices. Large scale biofuel production may be possible in the long term through subsidies, crude oil price rises and legislation

Holding up mirrors: reflections on academic literacy development across course curricula

The aim of the HEPPP funded project presented here is to embed support for the development of academic literacies (Lea & Street 1998) by developing inclusive curricula in courses with a high percentage of students from low socioeconomic status (LSES) backgrounds (Devlin et al. 2012). Reflection is central in both the Bachelor of Early Childhood Education (BECE) and the Bachelor of Social Work, and the student profiles in these two courses mirror each other, but the approach taken differs. Many BECE students enter university through a TAFE pathway, some have low or no school exit scores and may have faced significant educational disadvantage in the past (Whitington et al. 2009). The BECE team responded to the invitation to use the Harper (2011) framework for academic literacy mapping by revising it and making it their own. Similarly, a large proportion of social work students are mature aged and first in their family to attend university with many entering via the TAFE sector (Goldingay et al. 2011). This earlier study found differences between staff and student perceptions of the academic skills needed for success, so resources developed through the project drew on the student voice and student perceptions to invite new students into disciplinary practices. This presentation will illustrate the approaches taken by Language and Learning Advisers (LLAs) working collaboratively with these two academic teams to help academic staff reflect on, scaffold and support the development of the academic literacies relevant to their discipline and provide more relevant feedback (Jolly 2001)

Theology, News and Notes - Vol. 45, No. 04

Theology News & Notes was a theological journal published by Fuller Theological Seminary from 1954 through 2014.https://digitalcommons.fuller.edu/tnn/1134/thumbnail.jp

Strengthening Biblical Historicity vis-a`-vis Minimalism, 1992–2008 and Beyond. Part 2.3: Some Commonalities in Approaches to Writing Ancient Israel’s History

This series of articles covers scholarly works in English which can, at least potentially, be associated with a generally positive view of biblical historicity regarding periods preceding the Israelites’ return from exile. Part 2 covers works that treat the methodological issues at the center of the maximalist–minimalist debate. Parts 2.1 and 2.2 selectively survey the works of 24 non-minimalist scholars during two decades. In the absence of consensus, this article analyzes the works in Parts 2.1 and 2.2, tracing elements of approach that are held in common, at least among pluralities of non-minimalists (possible majorities are not noted). The first commonality of approach is that history is provisional, not final. The second is that history should become fully multidisciplinary. The third commonality is that historians should receive all historical evidence on an equal footing before examination and cross-examination. The fourth and last is that historians should become increasingly sensitive to cultural aspects and coding in ancient Near Eastern materials

(Re)acting Medicine: applying theatre in order to develop a whole-systems approach to understanding the healing response.

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Research in Drama Education: The Journal of Applied Theatre and Performance on 30/09/2014, available online: http://www.tandfonline.com/10.1080/13569783.2014.928007UK health and care provision is in crisis. Dominant practices, ideologies and infrastructure need to change. Our research team is investigating how performance-led research and creative practice is able to positively shape that change. Presently biomedicine holds the power; its reductionist research approach and acute medical model dominate. Neither are well-equipped to engage with increasing non-communicable, long-term, multi-issue, chronic ill-health. We believe that creative practitioners should be using their own well-established approaches to trouble this dominant paradigm to both form and inform the future of healing provision and wellbeing creation. Our transdisciplinary team (drama and medicine) is developing a methodology that is rooted in productive difference; an evolving synergy between two cultural and intellectual traditions with significant divergences in their world-view, perceptions, approaches and training methods. This commonality is underpinned by four assumptions that; (1) human-to-human interactions matter, (2) context matters, (3) the whole person and their community matters and (4) interpretation matters. Initially, we are using this methodology to investigate the fundamental human-to-human interaction of a person seeking healing (a healee) with a healer: we believe that this interaction enables the Healing Response - the intrinsic ability of the human organism to self-heal and regain homeostasis. In this paper we reflect on the project’s early stages

Theological diversity and canonical authority: an examination of how diverse viewpoints in the Old Testament may be acknowledged, interrelated and allowed to function theologically

SIGLELD:D49496/84 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Characteristics of sap trees used by yellow-bellied gliders in southern Queensland

An extensive survey was conducted to locate sap trees used by the yellow-bellied glider (Petaurus australis) throughout the forests and woodlands of southern Queensland, across an area of 43.7 million hectares. We recorded the characteristics of 478 sap trees located at 109 of 297 sites surveyed. Only 13 tree species were selected by gliders for sap feeding throughout the study region, with the grey gum species Eucalyptus longirostrata and E. biturbinata most likely to be incised for sap. Of the tree species used for sap feeding by gliders, trees \u3e40 cm in diameter at breast height (DBH) were used more than would be expected on the basis of their abundance in the forest. The number of sap trees with active and recently active feed scars at a site ranged from 0 to 12. Factors that appear to influence the abundance of active and recently active sap trees at a site include intensity of disturbance (basal area of cut stumps and dead trees), the number of stems in the 41-60 and 61-80 cm DBH classes, and number of Myrtaceae species. The response to these variables could be indicative of habitat quality, and the availability of alternative foraging substrates such as flower cover and decorticating bark. Intensification of selective logging in south-east Queensland, as an outcome of the Southeast Queensland Regional Forest Agreement, could potentially marginalise glider habitat. This would necessitate the retention of potential, or \u27recruit\u27, sap trees to maintain yellow-bellied glider habitat in these areas. © CSIRO 2005