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The purpose of this paper is to propose a robust method to estimate the parameters of Jiles‐Atherton model of ferromagnetic hysteresis by fitting the model to symmetrical hysteresis loops. The performance of the method is evaluated by both theoretical and experimental data.

Jiles‐Atherton model with five parameters describes the hysteretic behaviour of ferromagnetic materials. To calculate the model parameters, the most common data displaying the hysteresis features are the hysteresis loops stimulated by symmetrical steady state excitations, e.g. sinusoidal sources. Using the characteristic equations at specific points on these hysteresis loops, the Jiles‐Atherton model parameters can be determined by curve fitting and numerical optimized iteration.

Practicality and robustness were not well considered by the conventional parameter estimation method: the initial curve starting from demagnetization is not always available and a direct iterative algorithm to solve the characteristic equations is sensitive to the initial values of the iteration and the evaluation order of the equations because of two main reasons. The first one is that the basic equation group has non‐unique solutions, which is caused by the nonlinearity of the characteristic equations and the fact that there are more unknown quantities (i.e. five model parameters) than the equations available; the second reason is the multimodal feature of the problem, which means that there are many local minima for the iteration algorithm to be trapped in. So curve fitting around the loop tips is proposed before numerical iteration. The goal is to make the initial values, particularly saturation magnetization M_s, not far away from the desired solution to increase the possibility of converging to a physical result. The optimized iterative method with the enhanced ability to avoid local minima and find global roots is then applied to obtain the model parameters.

The proposed method overcomes the difficulties of the other techniques which assume zero remanence. It is also robust as it is guaranteed to converge to physical solutions. The method can facilitate further development and it formed the preliminary basis of our earlier work, where the variation of the Jiles‐Atherton model parameters with different magnetic field strengths was investigated and applied to the simulation of transformer inrush current.

The purpose of this paper is to consider the nature of leadership in the current context where the crisis in global capitalism seems to be encouraging a mechanistic approach to the management of healthcare. The paper urges an holistic leadership ethos to encourage an holistic approach to care and treatment.

The paper utilises an extensive overview of the leadership literature, and also used practical examples of care and leadership practice.

Care and capability need to be partners, but concern has been expressed at all levels of society that a reductionist model is being implemented in many caring professions.

The implications for leadership are that one of the most vital current requirements is to encourage a spirit-filled leadership at all levels in the organisations that provide care.

The paper addresses the issue that leadership can never be a purely intellectual or emotional activity, it must combine all aspects of the person in an holistic approach.

This paper aims to compare different static history-independent hysteresis models (mathematical-, behavioural- and physical-based ones) and a history-dependent hysteresis model in terms of parameter identification effort and accuracy.

The discussed models were tested for distorted-excitation waveforms to explore their predictions of complex magnetization curves. Static hysteresis models were evaluated by comparing the calculated and measured major and minor static hysteresis loops.

The analysis shows that the resulting accuracy of the different hysteresis models is strongly dependent on the excitation waveform, i.e. smooth excitations, distorted flux waveforms, transients or steady-state regimes. Obtained results show significant differences between predictions of discussed static hysteresis models.

The general aim was to identify the models on a very basic and limited set of measured data, i.e. if possible using only the measured major static loop of the material. The quasi-static major hysteresis loop was measured at B_max = 1.5 T.

The presented analysis allows selection of the most-suited hysteresis model for the sought-for application and appraisal of the individual limitations.

The presented analysis shows differences in intrinsic mechanisms to predict magnetization curves of the majority of the well-known static hysteresis models. The results are essential when selecting the most-suited hysteresis model for a specific application.

The investigation was aimed at magnetically‐nonlinear dynamic model of a single‐phase transformer, where the effects of dynamic hysteresis losses are accounted for by a simplified model. Such a modelling could be applied when analyzing the transient operating conditions or the impact of nonlinear and unbalanced loads on the transformer operation and the big power systems modelling.

Secondly, an inverse form of the Jiles‐Atherton hysteresis model was applied for the hysteresis losses of a transformer defining. In that sense this paper compares and evaluates both hysteresis models, where the possible errors caused by simplified model application are exposed.

The Jiles‐Atherton model can be applied when more accurate hysteresis models are required, however, at the cost of increased model complexity and required computational effort. Apart from that the main drawback is impossible application of such a modelling, when some of the input parameters are unknown. On the other hand the simplified hysteresis model does not increase the required computational effort substantially.

Both methods have been modified in such a way that they can be used when the magnetizing curve of the iron‐core material is not available, whilst the magnetically‐nonlinear characteristic of the entire device can be determined experimentally. The aforementioned characteristic can be given in the form of an approximation polynomial or in the form of a look‐up table.

Over several decades many ranking techniques have been proposed as aids to journal selection by libraries. We review those closely related to physics and others with novel features. There are three main methods of ranking: citation analysis, use or user judgement, and size or ‘productivity’. Citations offer an ‘unobtrusive’ quantitative measure, but not only is the absolute value of a citation in question, but also there is no consensus on a ‘correct’ way to choose the citing journals, nor of the ranking parameter. Citations can, however, point out anomalies and show the changing status of journals over the years. Use and user judgement also employ several alternative methods. These are in the main of limited applicability outside the specific user group in question. There is greater ‘parochialism’ in ‘use’ ranking than in ‘judged value’ lists, with citation lists the most international. In some cases, the attempted ‘quantification’ of subjective judgement will be misleading. Size and productivity rankings are normally concerned with one or other formulation of the Bradford distribution. Since the distribution is not universally valid, for library use the librarian must satisfy him/herself that the collection conforms to the distribution, or that his users would be well served by one that did. This may require considerable effort, and statistics gained will then render the Bradford distribution redundant.

The purpose of this paper is to present the method which relatively easily allows to approximate the hysteresis loop of the dynamo or transformer steel sheets. The paper also looks into the formulation of an equation allowing determination of distribution of the flux density and eddy currents in cross-section of these sheets.

An exponential function was applied in the presented method relating to the approximation of the hysteresis loop. When the field strength changes its value, then, the flux density are the sum or difference of a function, describing the lower or upper hysteresis curve and some “ransient” component. On the basis of Maxwell’s equations and Amper’s law, one non-linear differential equation was formulated which allows to calculate the flux density and eddy currents in a cross-section of a transformer sheet.

The method which relatively easily allows approximation of the hysteresis loop of ferromagnetic material is presented in the paper. The paper presents the derivation of one non-linear differential equation, allowing calculation of the flux density and eddy currents in the cross-section of the transformer sheets, taking into account the hysteresis phenomenon.

The paper presents the method that can be used in modeling of the hysteresis loops of dynamo or transformer sheets, and the final non-linear differential equation can be applied in calculations of the magnetic field and eddy currents in cross-section of the transformer sheets.

The paper refers to important issues of modeling and calculations of the magnetic and eddy current field distribution in transformer steel sheets.

Classically the magnetic material models are considered with a deterministic approach. Nevertheless, when submitted to the fabrication process, the magnetic core properties are negatively impacted and may be subject to variability during the process. This variability can be of such importance that the performances of the final device (electrical machine) will also present a noticeable variability. The aim of this research is to develop a stochastic model of the magnetic behaviour law of slinky stators used in claw pole generators. The proposed methodology is general and can be applied to other physical properties of electrical devices.

The approach is based on a methodology that uses experimental data and a statistical description of the magnetic properties. To that end, a set of samples issued from the same chain of assembly is considered. The hysteresis model is then developed by accounting for the parameter correlation structure.

It is found that the magnetic hysteresis properties of the studied samples can be modelled by means of statistical tools applied to the parameters of the hysteresis model. The dependency of the parameters can also be accounted for a more accurate modelling.

The paper proposes a statistical approach and a methodology that are applied to the hysteresis modelling accounting for the variability of the magnetic properties. The developed model can be further used in a numerical tool to represent the impact on the performances of electrical devices that are subject to the fabrication process variability.

The aim of this research is to explore the relationship between destination supply-side factors, visitor demand-side factors and the role of local government authorities in supporting the drive tourism market with effective interventions. A mixed methods approach was used to gather qualitative data from 14 destination stakeholders, which informed the development of a survey of 397 drive tourists to the Atherton Tablelands, in the far north of Australia. The findings identified stakeholder concerns about fragmented regional promotions by different regional entities, weakened destination branding and infrastructure needs. Drive tourist surveys indicated that although the destination provides a competitive tourism experience, there were concerns about the availability of information. This research highlights the danger of destination disunity, and the theoretical and practical contributions of the learning destination concept to understanding the importance of destination-wide, stakeholder collaboration, although it may be difficult to implement.

Small businesses are dominant in most economies and their owners likely experience high levels of distress. However, we have not fully explored how these common businesses meaningfully differ with respect to the stress process. Understanding the meaningful variations or subgroups (i.e., heterogeneity) in the small business population will advance occupational health psychology, both in research and practice (e.g., Schonfeld, 2017; Stephan, 2018). To systematize these efforts, the author identifies five commonly appearing “heterogeneity factors” from the literature as modifiers of stressors or the stress process among small business owners. These five heterogeneity factors include: owner centrality, individual differences, gender differences, business/ownership type, and time. After synthesizing the research corresponding to each of these five factors, the author offers specific suggestions for identifying and incorporating relevant heterogeneity factors in future investigations of small business owners’ stress. The author closes by discussing implications for advancing occupational health theories.