4,574 research outputs found
Bayesian mixture modelling and inference based Thompson sampling in Monte-Carlo tree search
No full textMonte-Carlo tree search is drawing great interest in the domain of planning under uncertainty, particularly when little or no domain knowledge is available. One of the central problems is the trade-off between exploration and exploitation. In this paper we present a novel Bayesian mixture modelling and inference based Thompson sampling approach to addressing this dilemma. The proposed Dirichlet-NormalGamma MCTS (DNG-MCTS) algorithm represents the uncertainty of the accumulated reward for actions in the MCTS search tree as a mixture of Normal distributions and inferences on it in Bayesian settings by choosing conjugate priors in the form of combinations of Dirichlet and NormalGamma distributions. Thompson sampling is used to select the best action at each decision node. Experimental results show that our proposed algorithm has achieved the state-of-the-art comparing with popular UCT algorithm in the context of online planning for general Markov decision processe
Heterogeneous Multiscale Methods for modelling surface topography in Elastohydrodynamic Lubrication line contacts
No full textA multiscale method for the Elastohydrodynamic Lubrication (EHL) of line contacts is derived based on the Heterogeneous Multiscale Methods. Periodicity applies to the topographical features and lubricant flow, data is homogenised over a range of variables at a micro-scale and coupled into a macro-scale model. This is achieved using flow factors as calculated from metamodels, which themselves evolve with the solution procedure. Results are given for an idealised topography and illustrate significant deviations from smooth surface assumptions as quantified by the flow factors. Improvements in the accuracy and efficiency with previous work and large fluctuations due to micro-EHL are also presented. Validation of the multiscale method with a deterministic topography is provided demonstrating good accuracy and efficiency
HM, BSE, and adaptation: a Canadian prairie perspective
No full textIn May 2003, the first case of bovine spongiform encephalopathy (BSE) was identified in Alberta, and the impact was immediately devastating on farmers and rural communities across Canada. Not only were farmers faced by the impacts of BSE, they were also contending with record low farm incomes, changing commodity prices, and overall rural depopulation. One grassroots adaptation to this rural crisis is the adoption of Holistic Management (HM) by farmers in western Canada. Although growing in popularity, HM has yet to be systematically assessed in the literature. The overall objectives of this study were to characterize HM; to assess to what degree it simultaneously addresses environmental, economic, and social priorities; to examine the impacts caused by the BSE crisis on HM and non-HM producers; and to explore the potential of HM for adapting and dealing with future crises. This was carried out through a questionnaire that was mailed to 784 HM producers across western Canada. Qualitative and quantitative analysis of survey data showed that HM allowed producers to systematically address all three pillars of sustainability (environment, economic, and social). In particular, the social aspect emphasized in the practice of HM was unique compared to other approaches to agricultural sustainability that focus on economic and/or environmental priorities.
When comparing HM producers to non HM producers, the HM producers were less impacted by the BSE crisis. Indeed, holistic managers described how the occurrence of BSE and subsequent consequences to the entire industry actually made them more resilient. The key factors that helped HM producers adapt to the BSE crisis were community involvement, within the family and larger community, and farm management. New farm practices, such as rotational grazing, and the HM clubs to support these new farm innovations/practices also aided producers in adapting to the BSE crisis. The results of this study demonstrate the value of alternative community based approaches that address agricultural challenges in a truly holistic and sustainable manner.October 200
Beyond the blank slate: identities and interests at work
No full textIdentity has become the focal point of interest across the social sciences and with reference to a range of issues and fields of study (Cornelissen, Haslam and Balmer 2007). Papers on identity have long been a feature of the International Labour Process Conference (ILPC) and the 2009 event had its largest stream on that topic. What is the point of interest and connection for labour process analysis (LPA)? Historically, it has been focused on the so-called ‘missing subject’ debate. This is a well-trodden territory that we do not want to repeat in any detail here (though see chapter by Jaros in this volume). Suffice to say, the central issue has been how to fill the hole originally left by Braverman’s objectivism – his self-limiting choice to omit consideration of worker action and attitudes in relation to what he regarded as the long run tendency to work degradation. In one sense, this is a wholly misleading frame for debate in that few ever agreed with Braverman’s position, for the simple reason that the ‘subjective factor’ is part of the objective picture. All subsequent research in a labour process tradition has, therefore, examined and theorised worker agency in one way or another. For mainstream LPA, the subjective factor is addressed through consideration of issues of resistance (and more recently misbehaviour), creativity (such as the significance of tacit skills and knowledge to labour and capital) and consent (notably the games and discretionary practices that help to tie workers to the workplace order). In broad terms, such emphases are consistent with the Marxian tradition of writings on the self-activity of labour (without the teleological belief in the historical mission of the working class) and literatures of industrial sociology that focused on informal self-organisation of workers
Labour process theory and critical realism
No full textThis chapter explores the potential synergies between labour process theory (LPT) and critical realism (CR). Its purpose is not to suggest that using CR is a substitute for theorising within the LPT tradition. Rather it is to set out the view that CR conceptions of a layered ontology may help to address and resolve some long standing issues about the scope and character of LPT, particularly those associated with the idea of a ‘core’ theory, as discussed below and in several chapters within this volume (see also Edwards 2005)
Hadamard products and golden - thompson type inequalities
No full textAbstractBy using Hadamard products we give some reasonable upper and lower bounds of Golden-Thompson type for ∥eH1 +…+ Hm∥, where Hi(i = 1, 2, …, m) are arbitrary Hermitian matrices and ∥·∥ is an arbitrary unitarily invariant norm
Multiplicities, interwoven threads, holistic paths: the phronetic long-haul approach
No full textNo abstract available
An assessment of the impact of possible CAP reform scenarios on Romanian agriculture
No full textUsing a simplified model, with key-variable the prices of two different possible scenarios of CAP reform after 2013 (moderate and radical), this paper present a comparison between the price effects of implementation of each reform scenario at 2015 horizon on Romanian agriculture. This short analysis shows that, under the presented hypotheses, the net welfare effect, due to the price changes, for the selected products, is positive in both reform scenarios, yet greater in the case of the radical reform. Integrated in the large context of Romanian development, it seems that the influence of CAP reform upon agriculture and rural areas will be most likely a gradual one: an interpenetration between the two scenarios is foreseeable, starting with the moderate reform that will dominate the period around 2013, the reform measures acquiring a more radical character afterwards.CAP reform, Romania, welfare effects, Agricultural and Food Policy,
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