961 resultados para Threshold concept theory
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Intuition is an important and under-researched concept in information systems. Prior exploratory research has shown that that there is potential to characterize the use of intuition in academic information systems research. This paper extends this research to all of the available issues of two leading IS journals with the aim of reaching an approximation of theoretical saturation. Specifically, the entire text of MISQ and ISR was reviewed for the years 1990 through 2009 using searchable PDF versions of these publications. All references to intuition were coded on a basis consistent with Grounded Theory, interpreted as a gestalt and represented as a mind-map. In the period 1990-2009, 681 incidents of the use of "intuition", and related terms were found in the articles reviewed, representing a greater range of codes than prior research. In addition, codes were assigned to all issues of MIS Quarterly from commencement of publication to the end of the 2012 publication year to support the conjecture that coding saturation has been approximated. The most prominent use of the term of "intuition" was coded as "Intuition as Authority" in which intuition was used to validate a statement, research objective or a finding; representing approximately 34 per cent of codes assigned. In research articles where mathematical analysis was presented, researchers not infrequently commented on the degree to which a mathematical formulation was "intuitive"; this was the second most common coding representing approximately 16 per cent of the codes. The possibly most impactful use of the term "intuition" was "Intuition as Outcome", representing approximately 7 per cent of all coding, which characterized research results as adding to the intuitive understanding of a research topic or phenomena.This research aims to contribute to a greater theoretical understanding of the use of intuition in academic IS research publications. It provides potential benefits to practitioners by providing insight into the use of intuition in IS management, for example, emphasizing the emerging importance of "intuitive technology". Research directions include the creation of reflective and/or formative constructs for intuition in information systems research and the expansion of this novel research method to additional IS academic publications and topics.
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The ‘Public interest’, even if viewed with ambiguity or scepticism, has been one of the primary means by which various professional roles of planners have been justified. Many objections to the concept have been advanced by writers in planning academia. Notwithstanding these, ‘public interest’ continues to be mobilised, to justify, defend or argue for planning interventions and reforms. This has led to arguments that planning will have to adopt and recognise some form of public interest in practice to legitimise itself.. This paper explores current debates around public interest and social justice and advances a vision of the public interest informed by complexity theory. The empirical context of the paper is the poverty alleviation programme, the Kudumbashree project in Kerala, India.
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Objectives In this study a prototype of a new health forecasting alert system is developed, which is aligned to the approach used in the Met Office’s (MO) National Severe Weather Warning Service (NSWWS). This is in order to improve information available to responders in the health and social care system by linking temperatures more directly to risks of mortality, and developing a system more coherent with other weather alerts. The prototype is compared to the current system in the Cold Weather and Heatwave plans via a case-study approach to verify its potential advantages and shortcomings. Method The prototype health forecasting alert system introduces an “impact vs likelihood matrix” for the health impacts of hot and cold temperatures which is similar to those used operationally for other weather hazards as part of the NSWWS. The impact axis of this matrix is based on existing epidemiological evidence, which shows an increasing relative risk of death at extremes of outdoor temperature beyond a threshold which can be identified epidemiologically. The likelihood axis is based on a probability measure associated with the temperature forecast. The new method is tested for two case studies (one during summer 2013, one during winter 2013), and compared to the performance of the current alert system. Conclusions The prototype shows some clear improvements over the current alert system. It allows for a much greater degree of flexibility, provides more detailed regional information about the health risks associated with periods of extreme temperatures, and is more coherent with other weather alerts which may make it easier for front line responders to use. It will require validation and engagement with stakeholders before it can be considered for use.
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Recent experimental observations of enhanced vibrational circular dichroism (VCD) in molecular systems with low-lying electronically excited states suggest interesting new applications of VCD spectroscopy. The theory describing VCD enhancement through vibronic coupling schemes was derived by Nafie in 1983, but only recently experimental evidence of VCD amplification has demonstrated the extent to which this effect can be exploited as a structure elucidation tool to probe local structure. In this Concept paper, we give an overview of the physics behind vibrational circular dichroism, in particular the equations governing the VCD amplification effect, and review the latest experimental developments with a prospective view on the application of amplified VCD to locally probe biomolecular structure.
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This paper addresses one of the issues in contemporary globalisation theory: the extent to which there is ‘one best way’ in which business can be done and organisations managed. It uses Czarniawska’s ‘Travels of Ideas’ model as an organising framework to present and understand how the concept of ‘Quality’, so important in contemporary approaches to manufacturing & services, and their management, travelled to, and impinged on, a newly opened vehicle assembly plant in Poland. The extent to which new meanings were mutually created in the process of translation is discussed, using ethnographic reporting and analysis techniques commonly used in diffusion research. Parallels between the process of translation as an idea becomes embedded into a new cultural location, and the processes which contemporary research has identified as important to organisational learning, are briefly discussed in conclusion.
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We report vibrational excitation (v(i) = 0 -> v(f) = 1) cross-sections for positron scattering by H(2) and model calculations for the (v(i) = 0 -> v(f) = 1) excitation of the C-C symmetric stretch mode of C(2)H(2). The Feshbach projection operator formalism was employed to vibrationally resolve the fixed-nuclei phase shifts obtained with the Schwinger multichannel method. The near threshold behavior of H(2) and C(2)H(2) significantly differ in the sense that no low lying singularity (either virtual or bound state) was found for the former, while a e(+)-acetylene virtual state was found at the equilibrium geometry (this virtual state becomes a bound state upon stretching the molecule). For C(2)H(2), we also performed model calculations comparing excitation cross-sections arising from virtual (-i kappa(0)) and bound (+i kappa(0)) states symmetrically located around the origin of the complex momentum plane (i.e. having the same kappa(0)). The virtual state is seen to significantly couple to vibrations, and similar cross-sections were obtained for shallow bound and virtual states. (c) 2007 Elsevier B.V. All rights reserved.
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We use the deformed sine-Gordon models recently presented by Bazeia et al [1] to take the first steps towards defining the concept of quasi-integrability. We consider one such definition and use it to calculate an infinite number of quasi-conserved quantities through a modification of the usual techniques of integrable field theories. Performing an expansion around the sine-Gordon theory we are able to evaluate the charges and the anomalies of their conservation laws in a perturbative power series in a small parameter which describes the ""closeness"" to the integrable sine-Gordon model. We show that in the case of the two-soliton scattering the charges, up to first order of perturbation, are conserved asymptotically, i.e. their values are the same in the distant past and future, when the solitons are well separated. We indicate that this property may hold or not to higher orders depending on the behavior of the two-soliton solution under a special parity transformation. For closely bound systems, such as breather-like field configurations, the situation however is more complex and perhaps the anomalies have a different structure implying that the concept of quasi-integrability does not apply in the same way as in the scattering of solitons. We back up our results with the data of many numerical simulations which also demonstrate the existence of long lived breather-like and wobble-like states in these models.
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This paper presents a theoretical analysis of the concept of historical consciousness. It argues that a focus on the epistemological problems of the concept can be a way of constructing a theory of the concept that both incorporates the diverse perspectives that exist in research about the concept and specifies how a historical consciousness can be developed in an individual.
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The outcome of an audience study supports theories stating that stories are a primary means by which we make sense of our experiences over time. Empirical examples of narrative impact are presented in which specific fiction film scenes condense spectators' lives, identities and beliefs. One conclusion is that spectators test the emotional realism of the narative for greater significance, connecting diegetic fiction experiences with their extra-diegetic world in their quest for meaning, self and identity. The 'banal' notion of the mediatization of religion theory is questioned as unsatisfactory in the theoretical context of individualized meaning-making processes. As a semantically negatively charged concept, it is problematic when analyzing empirical examples of spectators' use of fictional narratives, especially when trying to characterize the idiosyncratic and complex interplay between spectators' fiction emotions and their testing of mediated narratives in an exercise to find moral significance in extra-filmic life. Instead vernacular meaning-making is proposed.
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Aim. The aim of this study was to describe, explore and explain the concept of sustainability in nursing. Background. Although researchers in nursing and medicine have emphasised the issue of sustainability and health, the concept of sustainability in nursing is undefined and poorly researched. A need exists for theoretical and empirical studies of sustainability in nursing. Design. Concept analysis as developed by Walker and Avant. Method. Data were derived from dictionaries, international healthcare organisations and literature searches in the CINAHL and MEDLINE databases. Inclusive years for the search ranged from 1990 to 2012. A total of fourteen articles were found that referred to sustainability in nursing. Results. Sustainability in nursing involves six defining attributes: ecology, environment, future, globalism, holism and maintenance. Antecedents of sustainability require climate change, environmental impact and awareness, confidence in the future, responsibility and a willingness to change. Consequences of sustainability in nursing include education in the areas of ecology, environment and sustainable development as well as sustainability as a part of nursing academic programs and in the description of the academic subject of nursing. Sustainability should also be part of national and international healthcare organisations. The concept was clarified herein by giving it a definition. Conclusion. Sustainability in nursing was explored and found to contribute to sustainable development, with the ultimate goal of maintaining an environment that does not harm current and future generations' opportunities for good health. This concept analysis provides recommendations for the healthcare sector to incorporate sustainability and provides recommendations for future research.
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O presente artigo focaliza a genérica e abstrata análise monetária desenvolvida por Marx no inicio do Capital. Mais precisamente, pretende-se avaliar em que medida, se alguma, alguns aspectos da análise de Marx sobre o papel bastante contraditório desempenhado pela moeda no processo de circulação simples de mercadorias suportam uma interpretação sobre-determinista do método dialético por ele empregado. Baseando-se no conceito de sobre-determinação introduzido na literature Marxiana principalmente por Louis Althusser, o artigo conclui que o nexo real-monetário prevalecente na circulação simples de mercadorias pode ser concebida como um nexo sobre-determinado, ou seja, um nexo caracterizado por incorporar um regime de constitutividade.
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The aim of this paper is to analyze extremal events using Generalized Pareto Distributions (GPD), considering explicitly the uncertainty about the threshold. Current practice empirically determines this quantity and proceeds by estimating the GPD parameters based on data beyond it, discarding all the information available be10w the threshold. We introduce a mixture model that combines a parametric form for the center and a GPD for the tail of the distributions and uses all observations for inference about the unknown parameters from both distributions, the threshold inc1uded. Prior distribution for the parameters are indirectly obtained through experts quantiles elicitation. Posterior inference is available through Markov Chain Monte Carlo (MCMC) methods. Simulations are carried out in order to analyze the performance of our proposed mode1 under a wide range of scenarios. Those scenarios approximate realistic situations found in the literature. We also apply the proposed model to a real dataset, Nasdaq 100, an index of the financiai market that presents many extreme events. Important issues such as predictive analysis and model selection are considered along with possible modeling extensions.
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In this work we present a new clustering method that groups up points of a data set in classes. The method is based in a algorithm to link auxiliary clusters that are obtained using traditional vector quantization techniques. It is described some approaches during the development of the work that are based in measures of distances or dissimilarities (divergence) between the auxiliary clusters. This new method uses only two a priori information, the number of auxiliary clusters Na and a threshold distance dt that will be used to decide about the linkage or not of the auxiliary clusters. The number os classes could be automatically found by the method, that do it based in the chosen threshold distance dt, or it is given as additional information to help in the choice of the correct threshold. Some analysis are made and the results are compared with traditional clustering methods. In this work different dissimilarities metrics are analyzed and a new one is proposed based on the concept of negentropy. Besides grouping points of a set in classes, it is proposed a method to statistical modeling the classes aiming to obtain a expression to the probability of a point to belong to one of the classes. Experiments with several values of Na e dt are made in tests sets and the results are analyzed aiming to study the robustness of the method and to consider heuristics to the choice of the correct threshold. During this work it is explored the aspects of information theory applied to the calculation of the divergences. It will be explored specifically the different measures of information and divergence using the Rényi entropy. The results using the different metrics are compared and commented. The work also has appendix where are exposed real applications using the proposed method
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In the limit of small values of the aspect ratio parameter (or wave steepness) which measures the amplitude of a surface wave in units of its wave-length, a model equation is derived from the Euler system in infinite depth (deep water) without potential flow assumption. The resulting equation is shown to sustain periodic waves which on the one side tend to the proper linear limit at small amplitudes, on the other side possess a threshold amplitude where wave crest peaking is achieved. An explicit expression of the crest angle at wave breaking is found in terms of the wave velocity. By numerical simulations, stable soliton-like solutions (experiencing elastic interactions) propagate in a given velocities range on the edge of which they tend to the peakon solution. (c) 2005 Elsevier B.V. All rights reserved.