976 resultados para coupled-cluster theory
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We compare three alternative methods for eliciting retrospective confidence in the context of a simple perceptual task: the Simple Confidence Rating (a direct report on a numerical scale), the Quadratic Scoring Rule (a post-wagering procedure), and the Matching Probability (MP; a generalization of the no-loss gambling method). We systematically compare the results obtained with these three rules to the theoretical confidence levels that can be inferred from performance in the perceptual task using Signal Detection Theory (SDT). We find that the MP provides better results in that respect. We conclude that MP is particularly well suited for studies of confidence that use SDT as a theoretical framework.
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This research established innovative methods and a predictive model to evaluate water quality using the trace element and heavy metal concentrations of drinking water from the greater Brisbane area. Significantly, the combined use of Inductively Coupled Plasma - Mass Spectrometry and Chemometrics can be used worldwide to provide comprehensive, rapid and affordable analyses of elements in drinking water that can have a considerable impact on human health.
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We propose and mathematically examine a theory of calcium profile formation in unwounded mammalian epidermis based on: changes in keratinocyte proliferation, fluid and calcium exchange with the extracellular fluid during these cells' passage through the epidermal sublayers, and the barrier functions of both the stratum corneum and tight junctions localised in the stratum granulosum. Using this theory, we develop a mathematical model that predicts epidermal sublayer transit times, partitioning of the epidermal calcium gradient between intracellular and extracellular domains, and the permeability of the tight junction barrier to calcium ions. Comparison of our model's predictions of epidermal transit times with experimental data indicates that keratinocytes lose at least 87% of their volume during their disintegration to become corneocytes. Intracellular calcium is suggested as the main contributor to the epidermal calcium gradient, with its distribution actively regulated by a phenotypic switch in calcium exchange between keratinocytes and extracellular fluid present at the boundary between the stratum spinosum and the stratum granulosum. Formation of the extracellular calcium distribution, which rises in concentration through the stratum granulosum towards the skin surface, is attributed to a tight junction barrier in this sublayer possessing permeability to calcium ions that is less than 15 nm/s in human epidermis and less than 37 nm/s in murine epidermis. Future experimental work may refine the presented theory and reduce the mathematical uncertainty present in the model predictions.
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This study investigates the effects of trait anxiety on self-reported driving behaviours through its negative impacts on Central Executive functions. Following a self-report study that found trait anxiety to be significantly related to driving behaviours, the present study extended the predictions of Eysenck and Calvo’s Attentional Control Theory, proposing that anxiety affects driving behaviours, in particular driving lapses, through its impact across the Central Executive. Seventy-five Australian drivers participated in the study, completing the Parametric Go/No-Go and n-back tasks, as well as the State-Trait Anxiety Inventory and the Driving Behaviour Questionnaire. While both trait anxiety and processing efficiency of the Central Executive was found to significantly predict driving lapses, trait anxiety remained a strong predictor of driving lapses after processing efficiency was controlled for. It is concluded that while processing efficiency of the central Executive is a key determinant of driving lapses, another Central Executive function that is closer to the driving lapses in the trait anxiety – driving lapses relationship may be needed. Suggestions regarding how to improve future trait anxiety – driving behaviours research are discussed.
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Process modeling – the design and use of graphical documentations of an organization’s business processes – is a key method to document and use information about the operations of businesses. Still, despite current interest in process modeling, this research area faces essential challenges. Key unanswered questions concern the impact of process modeling in organizational practice, and the mechanisms through which impacts are developed. To answer these questions and to provide a better understanding of process modeling impact, I turn to the concept of affordances. Affordances describe the possibilities for goal-oriented action that a technical object offers to a user. This notion has received growing attention from IS researchers. The purpose of my research is to further develop the IS discipline’s understanding of affordances and impacts from information objects, such as process models used by analysts for information systems analysis and design. Specifically, I seek to extend existing theory on the emergence, perception and actualization of affordances. I develop a research model that describes the process by which affordances emerge between an individual and an object, how affordances are perceived, and how they are actualized by the individual. The proposed model also explains the role of available information for the individual, and the influence of perceived actualization effort. I operationalize and test this research model empirically, using a full-cycle, mixed methods study consisting of case study and experiment.
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Purpose Using the Theory of Planned Behaviour (TPB) framework, this study explored whether the standard TPB constructs explained variance in Gen Y individuals’ intentions to join their ideal organisation. Design/methodology/approach A mixed methods approach was used featuring qualitative and quantitative methods. Findings The overall TPB model accounted for a significant 51.6% of the variance in intention to join one’s ideal organisation in the next six months with the significant predictors in the model being subjective norm and perceived behaviour control but not attitude. Research limitations/implications Using graduating students from a single Australian university sample may mean that the current findings may not extend to all Gen Y individuals. The current study has demonstrated the explanatory utility of the TPB in relation to graduate Gen Y’s intention to join their ideal organisation, providing further evidence of the robustness of the TPB framework in an organisational setting. Practical implications These findings have implications for enhancing understanding of the most effective recruitment processes for Gen Y students entering the workforce. The findings could inform recruitment policies and strategies to attract Gen Y applicants. Originality/value To our knowledge this study is the first application of the TPB to this topic. The current research extends the recruitment literature with a theoretically-based investigation. Identification of factors which inform organisational recruitment strategies, allow organisations to stand out from their competitors and potentially achieve a larger application pool from which to select the best human capital and sustain competitive advantage.
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Objective. To evaluate the effectiveness of a single-session online theory of planned behaviour (TPB)-based intervention to improve sun-protective attitudes and behaviour among Australian adults. Methods. Australian adults (N = 534; 38.7% males; Mage = 39.3 years) from major cities (80.9%), regional (17.6%) and remote areas (1.5%)were recruited and randomly allocated to an intervention (N=265) and information only group (N = 267). The online intervention focused on fostering positive attitudes, perceptions of normative support, and control perceptions for sun protection. Participants completed questionnaires assessing standard TPB measures (attitude, subjective norm, perceived behavioural control, intention, behaviour) and extended TPB constructs of group norm (friends, family), personal norm, and image norm, pre-intervention (Time 1) and one week (Time 2) and one month post-intervention (Time 3). Repeated Measures Multivariate Analysis of Variance tested intervention effects across time. Results. Intervention participants reported more positive attitudes towards sun protection and used sunprotective measures more often in the subsequent month than participants receiving information only. The intervention effects on control perceptions and norms were non-significant. Conclusions. A theory-based online intervention fostering more favourable attitudes towards sun safety can increase sun protection attitudes and self-reported behaviour among Australian adults in the short term.
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A long-held assumption in entrepreneurship research is that normal (i.e., Gaussian) distributions characterize variables of interest for both theory and practice. We challenge this assumption by examining more than 12,000 nascent, young, and hyper-growth firms. Results reveal that variables which play central roles in resource-, cognition-, action-, and environment-based entrepreneurship theories exhibit highly skewed power law distributions, where a few outliers account for a disproportionate amount of the distribution's total output. Our results call for the development of new theory to explain and predict the mechanisms that generate these distributions and the outliers therein. We offer a research agenda, including a description of non-traditional methodological approaches, to answer this call.
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This thesis explored safety culture in a large Australasian construction and mining organisation, with a view to understanding how theory and practice can be integrated to improve safety culture and related outcomes within the industry. The research comprised three studies that investigated the relationship between safety culture, safety motivation, leadership and safety behaviour, and examined differences in perceptions of safety culture across the organisation. Research methodologies and samples included a modified Delphi method with safety leaders (n=41), a quantitative survey with a cross-section of the organisation (n=2,957), and group interviews with frontline supervisors and workers (n=29).
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Background and Purpose: - This paper focuses on the learning culture within the high performance levels of rowing. In doing so, we explore the case of an individual’s learning as he moves across athletic, coaching and administrative functions. This exploration draws on a cultural learning framework and complementary theorisings related to reflexivity. Method - This study makes use of an intellectually, morally and collaboratively challenging approach whereby one member of the research team was also the sole participant of this study. The participant’s careers as a high performance athlete, coach and administrator, coupled with his experience in conducting empirical research presented a rare opportunity to engage in collaborative research (involving degrees of insider and outsider status for each of the research team). We acknowledge that others have looked to combine roles of coach / athlete / administrator with that of researcher however few (if any) have attempted to combine them all in one project. Moreover, coupled with the approach to reflexivity adopted in this study and the authorship contributions we consider this scholarly direction uncommon. Data were comprised of recorded research conversations, a subsequently constructed learning narrative, reflections on the narrative, a stimulated reflective piece from the participant, and a final (re)construction of the participant’s story. Accordingly, data were integrated through an iterative process of thematic analysis. Results - The cultural (i.e., the ways things get done) and structural (e.g., the rules and regulations) properties of high performance rowing were found to shape both the opportunities to be present (e.g., secure a place in the crew) and to learn (e.g., learn the skills required to perform at an Olympic level). However, the individual’s personal properties were brought to bear on re-shaping the constraints such that many limitations could be overcome. In keeping with the theory of learning cultures, the culture of rowing was found to position individuals (a coxswain in this case) differentially. In a similar manner, a range of structural features was found to be important in shaping the cultural and personal elements in performance contexts. For example, the ‘field of play’ was found to be important as a structural feature (i.e., inability of coach to communicate with athletes) in shaping the cultural and personal elements of learning in competition (e.g., positioning the coxswain as an in-boat coach and trusted crewmate). Finally, the cultural and structural elements in rowing appeared to be activated by the participant’s personal elements, most notably his orientation towards quality performance. Conclusion - The participant in this study was found to be driven by the project that he cares about most and at each turn he has bent his understanding of his sport back on itself to see if he can find opportunities to learn and subsequently explore ways to improve performance. The story here emphasises the importance of learner agency, and this is an aspect that has often been missing in recent theorising about learning. In this study, we find an agent using his ‘personal emergent powers to activate the resources in the culture and structure of his sport in an attempt to improve performance. We conclude from this account that this particular high performance rowing culture is one that provided support but nonetheless encouraged those involved, to ‘figure things out’ for themselves – be it as athletes, coaches and/or administrators.
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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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This paper reports on two lengthy studies in Physical education teacher education (PETE) conducted independently but which are epistemologically and methodologically linked. The paper describes how personal construct theory (PCT) and its associated methods provided a means for PETE students to reflexively construct their ideas about teaching physical education over an extended period. Data are drawn from each study in the form of a story of a single participant to indicate how this came about. Furthermore we suggest that PCT might be both a useful research strategy and an effective approach to facilitate professional development in a teacher education setting.
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Previous studies showed that a significant number of the particles present in indoor air are generated by cooking activities, and measured particle concentrations and exposures have been used to estimate the related human dose. The dose evaluation can be affected by the particle charge level which is usually not considered in particle deposition models. To this purpose, in this paper we show, for the very first time, the electric charge of particles generated during cooking activities and thus extending the interest on particle charging characterization to indoor micro-environments, so far essentially focused on outdoors. Particle number, together with positive and negative cluster ion concentrations, was monitored using a condensation particle counter and two air ion counters, respectively, during different cooking events. Positively-charged particle distribution fractions during gas combustion, bacon grilling, and eggplant grilling events were measured by two Scanning Mobility Particle Sizer spectrometers, used with and without a neutralizer. Finally, a Tandem Differential Mobility Analyzer was used to measure the charge specific particle distributions of bacon and eggplant grilling experiments, selecting particles of 30, 50, 80 and 100 nm in mobility diameter. The total fraction of positively-charged particles was 4.0%, 7.9%, and 5.6% for gas combustion, bacon grilling, and eggplant grilling events, respectively, then lower than other typical outdoor combustion-generated particles.
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We show that the cluster ion concentration (CIC) in the atmosphere is significantly suppressed during events that involve rapid increases in particle number concentration (PNC). Using a neutral cluster and air ion spectrometer, we investigated changes in CIC during three types of particle enhancement processes – new particle formation, a bushfire episode and an intense pyrotechnic display. In all three cases, the total CIC decreased with increasing PNC, with the rate of decrease being greater for negative CIC than positive. We attribute this to the greater mobility, and hence the higher attachment coefficient, of negative ions over positive ions in the air. During the pyrotechnic display, the rapid increase in PNC was sufficient to reduce the CIC of both polarities to zero. At the height of the display, the negative CIC stayed at zero for a full 10 min. Although the PNCs were not significantly different, the CIC during new particle formation did not decrease as much as during the bushfire episode and the pyrotechnic display. We suggest that the rate of increase of PNC, together with particle size, also play important roles in suppressing CIC in the atmosphere.