804 resultados para Computational learning theory
Resumo:
In recent years there has been an explosive growth in the development of adaptive and data driven methods. One of the efficient and data-driven approaches is based on statistical learning theory (Vapnik 1998). The theory is based on Structural Risk Minimisation (SRM) principle and has a solid statistical background. When applying SRM we are trying not only to reduce training error ? to fit the available data with a model, but also to reduce the complexity of the model and to reduce generalisation error. Many nonlinear learning procedures recently developed in neural networks and statistics can be understood and interpreted in terms of the structural risk minimisation inductive principle. A recent methodology based on SRM is called Support Vector Machines (SVM). At present SLT is still under intensive development and SVM find new areas of application (www.kernel-machines.org). SVM develop robust and non linear data models with excellent generalisation abilities that is very important both for monitoring and forecasting. SVM are extremely good when input space is high dimensional and training data set i not big enough to develop corresponding nonlinear model. Moreover, SVM use only support vectors to derive decision boundaries. It opens a way to sampling optimization, estimation of noise in data, quantification of data redundancy etc. Presentation of SVM for spatially distributed data is given in (Kanevski and Maignan 2004).
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BACKGROUND: The structure and organisation of ecological interactions within an ecosystem is modified by the evolution and coevolution of the individual species it contains. Understanding how historical conditions have shaped this architecture is vital for understanding system responses to change at scales from the microbial upwards. However, in the absence of a group selection process, the collective behaviours and ecosystem functions exhibited by the whole community cannot be organised or adapted in a Darwinian sense. A long-standing open question thus persists: Are there alternative organising principles that enable us to understand and predict how the coevolution of the component species creates and maintains complex collective behaviours exhibited by the ecosystem as a whole? RESULTS: Here we answer this question by incorporating principles from connectionist learning, a previously unrelated discipline already using well-developed theories on how emergent behaviours arise in simple networks. Specifically, we show conditions where natural selection on ecological interactions is functionally equivalent to a simple type of connectionist learning, 'unsupervised learning', well-known in neural-network models of cognitive systems to produce many non-trivial collective behaviours. Accordingly, we find that a community can self-organise in a well-defined and non-trivial sense without selection at the community level; its organisation can be conditioned by past experience in the same sense as connectionist learning models habituate to stimuli. This conditioning drives the community to form a distributed ecological memory of multiple past states, causing the community to: a) converge to these states from any random initial composition; b) accurately restore historical compositions from small fragments; c) recover a state composition following disturbance; and d) to correctly classify ambiguous initial compositions according to their similarity to learned compositions. We examine how the formation of alternative stable states alters the community's response to changing environmental forcing, and we identify conditions under which the ecosystem exhibits hysteresis with potential for catastrophic regime shifts. CONCLUSIONS: This work highlights the potential of connectionist theory to expand our understanding of evo-eco dynamics and collective ecological behaviours. Within this framework we find that, despite not being a Darwinian unit, ecological communities can behave like connectionist learning systems, creating internal conditions that habituate to past environmental conditions and actively recalling those conditions. REVIEWERS: This article was reviewed by Prof. Ricard V Solé, Universitat Pompeu Fabra, Barcelona and Prof. Rob Knight, University of Colorado, Boulder.
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Feedback-related negativity (FRN) is an ERP component that distinguishes positive from negative feedback. FRN has been hypothesized to be the product of an error signal that may be used to adjust future behavior. In addition, associative learning models assume that the trial-to-trial learning of cueoutcome mappings involves the minimization of an error term. This study evaluated whether FRN is a possible electrophysiological correlate of this error term in a predictive learning task where human subjects were asked to learn different cueoutcome relationships. Specifically, we evaluated the sensitivity of the FRN to the course of learning when different stimuli interact or compete to become a predictor of certain outcomes. Importantly, some of these cues were blocked by more informative or predictive cues (i.e., the blocking effect). Interestingly, the present results show that both learning and blocking affect the amplitude of the FRN component. Furthermore, independent analyses of positive and negative feedback event-related signals showed that the learning effect was restricted to the ERP component elicited by positive feedback. The blocking test showed differences in the FRN magnitude between a predictive and a blocked cue. Overall, the present results show that ERPs that are related to feedback processing correspond to the main predictions of associative learning models. ■
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This thesis attempts to quantify the amount of information needed to learn certain tasks. The tasks chosen vary from learning functions in a Sobolev space using radial basis function networks to learning grammars in the principles and parameters framework of modern linguistic theory. These problems are analyzed from the perspective of computational learning theory and certain unifying perspectives emerge.
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Esta edición revisada y actualizada con material adicional incorpora muchos de los cambios ocurridos en el campo de la educación de adultos en los últimos años. Entre sus novedades se destacan: material sobre las implicaciones éticas y políticas del aprendizaje permanente; repercusión de la globalización y de los cambios sociales; información sobre cómo las tecnologías están afectando al aprendizaje de la gente; también se incluyen diversos enfoques sobre el conocimiento y la adquisición y evaluación de conocimientos.
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Purpose – The purpose of this paper is to demonstrate analytically how entrepreneurial action as learning relating to diversifying into technical clothing – i.e. a high-value manufacturing sector – can take place. This is particularly relevant to recent discussion and debate in academic and policy-making circles concerning the survival of the clothing manufacture industry in developed industrialised countries. Design/methodology/approach – Using situated learning theory (SLT) as the major analytical lens, this case study examines an episode of entrepreneurial action relating to diversification into a high-value manufacturing sector. It is considered on instrumentality grounds, revealing wider tendencies in the management of knowledge and capabilities requisite for effective entrepreneurial action of this kind. Findings – Boundary events, brokers, boundary objects, membership structures and inclusive participation that addresses power asymmetries are found to be crucial organisational design elements, enabling the development of inter- and intracommunal capacities. These together constitute a dynamic learning capability, which underpins entrepreneurial action, such as diversification into high-value manufacturing sectors. Originality/value – Through a refinement of SLT in the context of entrepreneurial action, the paper contributes to an advancement of a substantive theory of managing technological knowledge and capabilities for effective diversification into high-value manufacturing sectors.
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Mainstreaming the LforS approach is a challenge due to dive rging institutional priorities, customs, and expectations of classically traine d staff. A workshop to test LforS theory and practice, and explore how to mainstream it, took place in a concrete context in a rural district of Mozambique, focusing on agricultural, forest and water resources. The evaluation showed that the principles of interaction applied pe rmitted to link rational know ledge with practical experience through mutual learning and iterative self-reflection. The combination of learning techniques was considered usef ul; participants called for further opportunities to apply the LforS methodology, proposing next steps.
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Network governance of collective learning processes is an essential approach to sustainable development. The first section of the article briefly refers to recent theories about both market and government failures that express scepticism about the way framework conditions for market actors are set. For this reason, the development of networks for collective learning processes seems advantageous if new solutions are to be developed in policy areas concerned with long-term changes and a stepwise internalisation of externalities. With regard to corporate actors’ interests, the article shows recent insights from theories about the knowledge-based firm, where the creation of new knowledge is based on the absorption of societal views. This concept shifts the focus towards knowledge generation as an essential element in the evolution of sustainable markets. This involves at the same time the development of new policies. In this context innovation-inducing regulation is suggested and discussed. The evolution of the Swedish, German and Dutch wind turbine industries are analysed based on the approach of governance put forward in this article. We conclude that these coevolutionary mechanisms may take for granted some of the stabilising and orientating functions previously exercised by basic regulatory activities of the state. In this context, the main function of the governments is to facilitate learning processes that depart from the government functions suggested by welfare economics.
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This paper fills an important gap in the human resource development (HRD) literature by considering the role that NGO intermediation initiatives can play in bringing together and developing corporate procurement officials (CPOs) and ethnic minority business owner-managers (EMBOs) supplying goods and services. It has been suggested that such initiatives hold great promise in helping ethnic minority businesses escape from their disadvantageous sectoral concentration in the UK. Using situated learning theory as an application lens, the main aim of this paper is to demonstrate how nurturing communities of practice of CPOs and EMBOs and facilitating their interaction can help their professional development and their approaches to procuring and supplying, respectively. The paper reports on the authors' experience with an action research programme encompassing two intermediation initiatives of this kind. The lessons drawn from this study are useful for all those concerned with HRD for inclusive procurement; intermediaries promoting inclusive procurement, large procurers who are willing to engage with supplier diversity and ethnic minority suppliers who wish to access corporate procurement systems and 'break-out'. © 2013 Taylor & Francis.
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Although the role of strategic leadership in developing organizational learning capabilities has been examined to a certain extent, the specific behaviors and mechanisms through which these capabilities are developed have not been adequately understood. Paucity of research in this direction is even more conspicuous in a small firm/entrepreneurship context, which has been linked to innovation, economic growth, and employment generation. Reporting on an ethnographic study of a knowledge-intensive, growth-oriented small firm, this article addresses this gap in the literature by integrating strategic leadership and organizational learning theory in an entrepreneurship context. In this undertaking, situated learning theory is used as the major analytical lens, to shed light on how strategic leadership can build organizational learning capabilities that underpin entrepreneurial performance in small firms. Finally, implications for situated learning theory as an organizational learning perspective and leadership practice in an entrepreneurship context are submitted. © 2012 Wiley Periodicals, Inc.
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An organisation’s ability to internalise external knowledge and learn from various sources in undertaking new product development and/or entering a new market is crucial to its competitive performance. Nevertheless, little attention has been paid to how growth-oriented small firms identify and exploit entrepreneurial opportunities, i.e. take entrepreneurial action, related to such methods of development, in a mature, contracting industry. The latter is particularly relevant to recent discussion and debate in academic and policy-making circles concerning the salvage of the clothing manufacture industry in developed industrialised countries, by intensifying efforts relating to diversification into high value manufacturing sectors. This paper, based on an instrumental case-firm, demonstrates analytically how learning as entrepreneurial action relating to diversifying into /technical clothing – i.e. a high value manufacturing/innovatory sector - takes place, drawing on situated learning theory. It is argued that learning relating to such entrepreneurial action is dynamic in nature and is founded on specific organising principles that foster both inter- and intracommunal learning.
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Purpose – The purpose of this paper is to evaluate how a UK business school is addressing the Government's skills strategy through its Graduate Certificate in Management, and to identify good practice and development needs and to clarify how the Graduate Certificate is adapting to the needs of Generation X and Millennial students. The paper also aims to test Kolb and Kolb's experiential learning theory (ELT) in a business school setting. Design/methodology/approach – A case study methodology was adopted. In order to get a cross-section of views and triangulate the data, three focus groups were held, supported by reading documentation about the programme of study. Findings – The skills strategy is not just an ambition for some business schools, but is already part of the curriculum. Generation X and the Millennials have more in common with the positive attitudes associated with older generations than stereotyped views might allow. ELT provides a useful theoretical framework for evaluating a programme of study and student attitudes. Research limitations/implications – The research findings from one case study are reported, limiting the generalisability of the study. Practical implications – Good practice and development needs are identified which support the implementation of the Government's skills strategy and address employer concerns about student skills. Originality/value – New empirical data are reported which supports the use of ELT in evaluating programmes of study and student attitudes to work.