64 resultados para Conformal Field Theory


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Thunderstorm downbursts are important for wind engineers as they have been shown to produce the design wind speeds for mid to high return periods in many regions of Australia [1]. In structural design codes (e.g. AS/NZS1170.02-02) an atmospheric boundary layer (ABL) is assumed, and a vertical profile is interpolated from recorded 10 m wind speeds. The ABL assumption is however inaccurate when considering the complex structure of a thunderstorm outflow, and its effects on engineered structures. Several researchers have shown that the downburst, close to its point of divergence is better represented by an impinging wall jet profile than the traditional ABL. Physical modelling is the generally accepted approach to estimate wind loads on structures and it is therefore important to physically model the thunderstorm downburst so that its effects on engineered structures may be studied. An advancement on the simple impinging jet theory, addressed here is the addition of a pulsing mechanism to the jet which allows not only the divergent characteristics of a downburst to be produced, but also it allows the associated leading ring vortex to be developed. The ring vortex modelling is considered very important for structural design as it is within the horizontal vortex that the largest velocities occur [2]. This paper discusses the flow field produced by a pulsed wall jet, and also discusses the induced pressures that this type of flow has on a scaled tall building.

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The continuous steady-state current drive in a spherical argon plasma by transverse oscillating magnetic field (OMF) is investigated. The experimental results reveal that a rotating magnetic field is generated, and its amplitude depends linearly on the external steady vertical magnetic field. It has been shown that steady toroidal currents of up to about 400 A can be driven by a 490 kHz OMF with an input power of 1.4 kW. The generation of steady toroidal magnetic fields directed oppositely in the upper and lower hemispheres have been recorded. The measurements of time-varying magnetic fields unveil a strong nonlinear effect of the frequency-doubled field harmonics generation. The electron number density and temperature of up to 6.2×1018 m-3 and 12 eV have been obtained. The observed effects validate the existing theory of the OMF current drive in spherical plasmas.

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"The 3rd edition of this classic book offers practitioners, researchers and students a comprehensive introduction to, and overview of, career theory; introduces the Systems Theory Framework of career development; and demonstrates its considerable contemporary and innovative application to practice. A number of authors have identified the framework as one of a small number of significant innovations in the career development literature. The Systems Theory Framework of career development was developed to provide coherence to the career development field by providing a comprehensive conceptualisation of the many existing theories and concepts relevant to understanding career development. It is not designed to be a theory of career development; rather systems theory is introduced as the basis for an overarching, or metatheoretical, framework within which all concepts of career development, described in the plethora of career theories, can be usefully positioned and utilised in both theory and practice. It has been applied to the career development of children, adolescents and women. Since its first publication, the Systems Theory Framework has been the basis of numerous publications focusing on theoretical application and integration, practice and research, with a growing number of these by authors other than the framework developers. Its application across cultures also has been emphasised. The theoretical and practical unity of the Systems Theory Framework makes this book a worthy addition to the professional libraries of practitioners, researchers and students, new to, or experienced in, the field of career development."--PUBLISHER WEBSITE

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In 2008 we brought together much work at the intersection of entrepreneurship and human resource management (HRM) (Barrett & Mayson, 2008), after calls for more research (Baron, 2003; Katz, Aldrich, Welbourne & Williams, 2000; Tansky & Heneman, 2003). More has been collated since (Soriano, Dobon & Tansky, 2010; Tansky, Soriano & Dobon, 2010). We think it is now time again to regroup, pull conversational threads together and have a critical look at recent research at the intersection of HRM and Entrepreneurship. As editors of International Handbook of Entrepreneurship and HRM (Barrett & Mayson, 2008) we were privileged to collect 23 wonderfully diverse chapters from scholars around the globe addressing a range of issues at the intersection of the two pertinent disciplines or fields: HRM and entrepreneurship. This edition represented a coalescing of ideas that had been swirling about for some time. In three sections, the first dealt with theory and research methods, the second with the nature of HRM in small and entrepreneurial firms and the third with the functional aspects of HRM. At the time we were aware that the handbook did not cover the entire field and many topics were left unexplored. For example, the topic of regulation was generally absent while issues such as career advancement, performance management, organisational change and gender, diversity and ethnicity were also missing. In essence, the majority of those contributions sought to develop an understanding of the context in which particular aspects of HRM can be played out.

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AN ENGINEERING Workshop was held from 21 to 24 November 2006 in Veracruz, Mexico. Forty delegates from 12 countries attended the workshop on theory and practice of milling and diffusion extraction. This report provides a general overview of activities undertaken during that workshop which consisted of five technical sessions over two days with presentations and discussions plus two days of field and factory visits. Topics covered during the technical sessions included: power transmissions, cane preparation, diffusers, mills, and a comparison of milling and diffusion.

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I develop a model of individuals’ intentions to discontinue information system use. Understanding these intentions is important because they give insights into users’ willingness to carry out system tasks, and provide a basis for maintenance decisions as well as possible replacement decisions. I offer a first conceptualization of factors determining users’ discontinuance intentions on basis of existing literature on technology use, status quo bias and dual factor concepts. The model is grounded in rational choice theory to distinguish determinants of a conscious decision between continuing or discontinuing IS use. I provide details on the empirical test of the model through a field study of IS users in a retail organization. The work will have implications for theory on information systems continuance and dual-factor logic in information system use. The empirical findings will provide suggestions for managers dealing with cessation of information systems and work routine changes in organizations.

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The celebrated work of Lortie (1975) alerted teacher educators to the extended period of 'apprenticeship' that student teachers have been through before they arrive at teacher education programmes. The subjective implicit theories (Marland, 1992) developed by prospective teachers are shaped by their lifeworld experiences at school and in the case of physical education teachers, their experiences in sport. The biography of physical education teacher education (PETE) students tends to be characterised by ecto-mesomorphic individuals who have been socialised by the rigours of highly competitive sport (Gore, 1990; Macdonald, 1992; Rossi, 1996). We can add to this, the requirements of teacher preparation in physical education which for the most part are dominated by the traditions and rhetoric of the 'natural' bio-physical sciences; largely a legacy of Henry's (1964) work on physical education as an academic discipline, as well as that of Abernathy and Waltz the same year (Abernathy & Waltz, 1964). In the United Kingdom, Curl (1973) further advanced the argument in an attempt to justify human movement as an independent field of study with its own corpus of knowledge. It is little wonder then, that the dominant pedagogical discourse in physical education is, as Tinning (1991) discusses, one of performance pedagogy (see also Hendry, 1986 for an earlier discussion). The knowledge required to support such a discourse could be described as 'official' (Apple, 1993) and it assumes such status by virtue of the power appropriated by and bestowed upon the scientific community in PETE (Macdonald & Tinning, 1995; Sparkes, 1989, 1993). However, there are social reifiers too, and these tend to relate to the social construction of the body (Kirk, 1993; Kirk & Spiller, 1994; Gilroy, 1994) and what Tinning (1985) has termed the Cult of Slenderness. Furthermore the 'slender image' has become a signifier of 'good health'. This is inextricably linked to what might be considered as a health triplex—'exercise = fitness = health' (see Kirk & Colquhoun, 1989; Tinning & Kirk, 1991) which in Australia, underpins curriculum packages such as Daily Physical Education which teachers (often including physical education primary...

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The influence of constructivism and the ongoing drive for convergence, both of career theories and between theory and practice, have been key drivers in the career development literature for two decades (Patton, International Handbook of Career Guidance, 2008). Both contextual action theory and systems theory are derived from the root metaphor of contextualism, which has been proffered as a worldview to assist scientists and practitioners in organizing day-to-day experiential data. This chapter identifies the theoretical contributions of the Systems Theory Framework (STF) (Patton and McMahon, Career development and systems theory: A new development, 1999, Career psychology in South Africa, 2006) and Contextual Action Theory (Young and Valach, The future of career, 2000, Journal of Vocational Behavior 64:499–514, 2004; Young et al., Career choice and development, 1996, Career choice and development, 2002), each of which has advanced thinking in theory integration and in the integration between theory and practice in the career development and counseling field. Young et al. (Career development in childhood and adolescence, 2007) noted the connections between the Patton and McMahon systems theory approach and the contextual action theory approach and these connections will be highlighted in terms of the application of these theoretical developments to practice in career counseling, with a particular focus on the commonalities between the two approaches and what counselors can learn from each of them. In particular, this chapter will discuss common conceptual understandings and practice dimensions.

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Hardware ventures are emerging entrepreneurial firms that create new market offerings based on development of digital devices. These ventures are important elements in the global economy but have not yet received much attention in the literature. Our interest in examining hardware ventures is specifically in the role that information system (IS) resources play in enabling them. We ask how the role of IS resources for hardware ventures can be conceptualized and develop a framework for assessment. Our framework builds on the distinction of operand and operant resources and distinguishes between two key lifecycle stages of hardware ventures: start-up and growth. We show how this framework can be used to discuss the role, nature, and use of IS for hardware ventures and outline empirical research strategies that flow from it. Our work contributes to broadening and enriching the IS field by drawing attention to its role in significant and novel phenomena.

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This chapter examines the personal reflections and experiences of several pre-service and newly graduated teachers, including Kristie, who were involved in the NETDS program. Their documented professional journeys, which include descriptions of struggling when their privileged, taken-for-granted ways of being were destabilized, and grappling with tensions related to their own predispositions and values, are investigated in the context of Whiteness and privilege theory.

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The work of French sociologist, anthropologist and philosopher Pierre Bourdieu has been influential across a set of cognate disciplines that can be classified as physical culture studies. Concepts such as field, capital, habitus and symbolic violence have been used as theoretical tools by scholars and students looking to understand the nature and purpose of sport, leisure, physical education and human movement within wider society. Pierre Bourdieu and Physical Culture is the first book to focus on the significance of Bourdieu’s work for, and in, physical culture. Bringing together the work of leading and emerging international researchers, it introduces the core concepts in Bourdieu’s thought and work, and presents a series of fascinating demonstrations of the application of his theory to physical culture studies. A concluding section discusses the inherent difficulties of choosing and using theory to understand the world around us. By providing an in-depth and multi-layered example of how theory can be used across the many and varied components of sport, leisure, physical education and human movement, this book should help all serious students and researchers in physical culture to better understand the importance of social theory in their work.

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This workshop will snapshot Bourdieu's sociology. In recognition of Bourdieu's work as a powerful theoretical instrument to speculate the reproduction of social orders and cultural values, the workshop will firstly discuss the core concepts of habitus, capital, and field – the foundational triad of Bourdieu's sociology. Although Bourdieu's original work was built on some quantitative studies, his sociology has been largely qualitatively used in education research. Different from the bulk of extant research, the workshop will secondly showcase some quantitative and mixed methods research that uses a Bourdieusian framework. Mindful of such a framework helping understand social practice at a macro level, the workshop will then make an attempt to think through the macro and the micro by weaving together Bourdieu's sociology with Garfinkel's ethnomethodology. The workshop will conclude with some reflections and communications in terms of how to better realise the full value of Bourdieu in education research.

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Social work students consistently identify their field placement as having the most impact on their learning. Despite this, research on learning activities used during placement and the impact on practice competency and social work identity is limited. This is the second paper from a research study exploring student experiences of learning on placement. Data were gathered from 263 social work students about 14 key learning activities they experienced during placement. The more regularly students engaged in learning activities with their social work supervisor, the more likely they were to report a sense of social work identity and feelings of practice competence. However, the regular use of learning activities varied widely between placements. Surprisingly, approximately half the students did not regularly have the opportunity to observe social work practice, have their practice observed, or to link social work theory and the Code of Ethics to their practice with their social work supervisor.

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Post-traumatic stress disorder (PTSD) is a debilitating psychiatric disorder that has a major impact on the ability to function effectively in daily life. PTSD may develop as a response to exposure to an event or events perceived as potentially harmful or life-threatening. It has high prevalence rates in the community, especially among vulnerable groups such as military personnel or those in emergency services. Despite extensive research in this field, the underlying mechanisms of the disorder remain largely unknown. The identification of risk factors for PTSD has posed a particular challenge as there can be delays in onset of the disorder, and most people who are exposed to traumatic events will not meet diagnostic criteria for PTSD. With the advent of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM V), the classification for PTSD has changed from an anxiety disorder into the category of stress- and trauma-related disorders. This has the potential to refocus PTSD research on the nature of stress and the stress response relationship. This review focuses on some of the important findings from psychological and biological research based on early models of stress and resilience. Improving our understanding of PTSD by investigating both genetic and psychological risk and coping factors that influence stress response, as well as their interaction, may provide a basis for more effective and earlier intervention.