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Article
Publication date: 1 June 2004

Guzmán Díaz González, Javier Gómez‐Aleixandre Fernández and Pablo Arboleya Arboleya

In the past years, there has been an increasing concern about turn‐to‐turn faults in power transformers, due to the high costs that unexpected outages cause. It is not…

Abstract

In the past years, there has been an increasing concern about turn‐to‐turn faults in power transformers, due to the high costs that unexpected outages cause. It is not always possible to analyse the transformer behaviour under such faults at rated conditions, since the tests are largely destructive. Therefore, models are of great importance to avoid severe damage to machines. In this paper, a model based on flux rearrangement around the damaged turn is presented. Two roles are assigned simultaneously to the damaged turn – i.e. the turn is seen as damaged but segregated from winding, and virtually undamaged belonging to the winding – and the damaged turn leakage flux is considered to be a coupling flux between the two roles. Thus, complex relations of magnetic couplings between the turn and the rest of the transformer are avoided, resulting in a very fast model, easy to develop further, which has been validated through a comparison with a finite element model.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 23 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 4 July 2016

Hua Li and Wolfgang Rucker

The purpose of this paper is to present an accurate and efficient hybrid method for the calculation of the inductance of a coil and its inductance change due to deformed…

Abstract

Purpose

The purpose of this paper is to present an accurate and efficient hybrid method for the calculation of the inductance of a coil and its inductance change due to deformed turns using numerical methods.

Design/methodology/approach

The paper opted for finite element method coupled with analytical method (FCA) to accurately calculate the inductance of a coil, which is used as reference value. An algorithm with a power function is presented to approximate the partial inductance matrix with the purpose of obtaining the percentage change of the inductance due to deformed turns by using the partial element equivalent circuit (PEEC) with an approximated model and an optimization process. The presented method is successfully validated by the numerical results.

Findings

The paper provides a systematic investigation of the inductance of an arbitrary shaped coil and shows how to accurately and efficiently evaluate the inductance change of a coil due to its deformed turns. It suggests that the inductance of a coil can be accurately calculated by using FCA and its percentage change due to deformed turns can be efficiently calculated by using the PEEC_Approximation.

Research limitations/implications

As this research is for the magnetostatics, the skin- and proximity-effects have not been taken into account.

Practical implications

The paper includes implication for the worst-case analysis of the coil’s inductance due to mechanical damage or manufacturing tolerance.

Originality/value

This paper fulfills an identified need to study how the inductance change of a coil can be obtained accurately and efficiently.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 35 no. 4
Type: Research Article
ISSN: 0332-1649

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Book part
Publication date: 30 May 2013

Romeo V. Turcan

This chapter introduces and discusses the concept of turning points from the ontological, epistemological and methodological perspectives, applying it to the…

Abstract

This chapter introduces and discusses the concept of turning points from the ontological, epistemological and methodological perspectives, applying it to the de-internationalization phenomenon to exemplify its deployment. As a concept that adds to the variance and complexity of the international business and management field, the turning point is seen as a valuable unit of analysis within the research field. It is expected that this chapter will encourage a dynamic scholarly conversation about the concept of turning point and how it can aid international business researchers in the development of a generalizable international business and management theory.

Details

Philosophy of Science and Meta-Knowledge in International Business and Management
Type: Book
ISBN: 978-1-78190-713-9

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Abstract

Details

The Handbook of Road Safety Measures
Type: Book
ISBN: 978-1-84855-250-0

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Book part
Publication date: 29 November 2019

Michael Volgger and Dieter Pfister

This introduction to the volume Atmospheric Turn in Culture and Tourism: Place, Design and Process Impacts on Customer Behaviour, Marketing and Branding (Emerald…

Abstract

This introduction to the volume Atmospheric Turn in Culture and Tourism: Place, Design and Process Impacts on Customer Behaviour, Marketing and Branding (Emerald) positions the atmospheric turn in the context of recent paradigmatic turns such as the linguistic turn, iconic turn, cultural turn, spatial turn, mobility turn and design turn. The specific contribution of the atmospheric turn is its profoundly holistic interest in overarching connections which are perceived with all senses and include both matter and idea. With its 22 chapters, this volume sets out to sharpen the atmospheric gaze and perception in research and beyond.

Details

Atmospheric Turn in Culture and Tourism: Place, Design and Process Impacts on Customer Behaviour, Marketing and Branding
Type: Book
ISBN: 978-1-83867-070-2

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Article
Publication date: 13 October 2020

Geeta Singh, Kaushik Bhattacharjee and Satish Kumar

The purpose if this paper is to examine the turn-of-the-month effect in the equity market of three major emerging countries – Brazil, India and China – from January 2000…

Abstract

Purpose

The purpose if this paper is to examine the turn-of-the-month effect in the equity market of three major emerging countries – Brazil, India and China – from January 2000 to December 2017.

Design/methodology/approach

Ordinary least square regression analysis is used to examine the presence of the turn-of-the-month effect and to test the efficiency of the emerging stock markets. The characteristics of the returns during the turn-of-the-month days are compared with that of the non-turn-of-the-month trading days.

Findings

The average returns during turn-of-the-month days for all the considered emerging market indices are significantly higher than the non-turn-of-the-month days for the full sample. For the subsample analysis, the average returns for Brazil and India for pre-GFC period are higher on the turn-of-the-month days than on the non-turn-of-the-month days. However, the effect disappears in China during the GFC period. During the crisis period, the results show that the turn-of-the-month effect disappears in Brazil and India, whereas for China, the effect is significant. For the post-GFC period, the-turn-of-the-month effect reappears for all the countries.

Practical implications

The results have important implications for both traders and investors. The authors’ results indicate that the market participants can time the stock markets of these countries by taking long positions especially during the times when the turn-of-the-month effect is highly significant.

Originality/value

To the best of the authors’ knowledge, this paper is the first to study the turn-of-the-month effect, in the key emerging countries such as Brazil, China and India. Second, the authors divide the sample into three subperiods based on the 2008 GFC such as pre-GFC, GFC and post-GFC to understand the dynamic behavior of turn-of-the-month effect over time. Most importantly, the authors control for the day-of-the-week effect while examining the turn-of-the-month effect.

Details

Managerial Finance, vol. 47 no. 4
Type: Research Article
ISSN: 0307-4358

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Article
Publication date: 27 August 2020

Bradley Bowden

Management history has in the past 15 years witnessed growing enthusiasm for “critical” research methodologies associated with the so-called “historic turn”. This paper…

Abstract

Purpose

Management history has in the past 15 years witnessed growing enthusiasm for “critical” research methodologies associated with the so-called “historic turn”. This paper aims to argue, however, that the “historic turn” has proved to an “historic wrong turn”, typically associated with confused and contradictory positions. In consequence, Foucault’s belief that knowledge is rooted in discourse, and that both are rooted in external structures of power, is used while simultaneously professing advocacy of White’s understanding that history is fictive, the product of the historian’s imagination.

Design/methodology/approach

This paper explores the intellectual roots of the historic (wrong) turn in the idealist philosophies of Nietzsche, Croce, Foucault, White and Latour as well as the critiques that have been made of those theories from within “critical” or “Left” theoretical frameworks.

Findings

Failing to properly acknowledge the historical origin of their ideas and/or the critiques of those ideas – and misrepresenting all contrary opinion as “positivist” – those associated with the historic (wrong) turn replicate the errors of their theoretical champions. The author thus witnesses a confusion of ontology (the nature of being) and epistemology (the nature of knowledge) and, consequently, of “facts” (things that exist independently of our fancy), “evidence” (how ascertain knowledge of a fact) and “interpretation” (how I connect evidence to explain an historical outcome).

Originality/value

Directed toward an examination of the conceptual errors that mark the so-called “historic turn” in management studies, this article argues that the holding contradictory positions is not an accidental by-product of the “historic turn”. Rather, it is a defining characteristic of the genre.

Details

Journal of Management History, vol. 27 no. 1
Type: Research Article
ISSN: 1751-1348

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Article
Publication date: 17 May 2021

Zhiqi Zhao, Lei Luo, Dandan Qiu, Songtao Wang, Zhongqi Wang and Bengt Ake Sunden

This study aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using…

Abstract

Purpose

This study aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis and critical points principles of three-dimensional vortex flow.

Design/methodology/approach

This aims to explore the 3 D separated flow fields and heat transfer characteristics at the end wall of a serpentine channel with various turn clearances using topological analysis as well as critical points principles of three-dimensional vortex flow.

Findings

The endwall heat transfer in the narrow spacing passage is significantly stronger than that in a wide spacing channel. As the gap clearance is kept at 0.87 times of the hydraulic diameter, the endwall heat transfer and thermal performance can be accordingly enhanced with low pressure drops, which is because a relatively strong concentrated impingement flow for the medium gap clearance helps to restrain the downstream fluid flow and enhance the shear effect of the secondary flow.

Practical implications

The numerical results can be applied in designing sharp turn of serpentine channel in heat exchangers, heat sinks, piping system, solar receiver and gas turbine blades.

Originality/value

The evolution mechanism of the vortices in the turning region under different gap clearance was analyzed, and thermal enhancement characteristics were predicted innovatively using topological analysis method.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 31 January 2020

Arch G. Woodside, Marylouise Caldwell and Jennifer Rebecca Calhoun

This study defines service breakdowns, service breakdown prevention, and “servicide” as they relate to service-dominant logic. The study reviews relevant relevant…

Abstract

Purpose

This study defines service breakdowns, service breakdown prevention, and “servicide” as they relate to service-dominant logic. The study reviews relevant relevant literature on these three topics. This study categorizes real-life examples into five levels of dramatic turns toward service degradations and breakdowns that range from customer being aware but not mentioning service inadequacy to the service breakdown resulting in death of the customer or service provider. Taking initial steps in developing dramatic turn theory and improving the practice of service breakdown prevention are the major contributions of this study.

Design/methodology/approach

This study is a conceptual contribution that includes a dramatic turn role-playing exercise (at category 4 among five categories of dramatic turns for pedagogical/on-site enacting/practicing and training of service professionals. The study emphasizes and shows how to create and enact role-playing scenarios to increase requisite variety, provide training modules and increase skills/expertise in service enactment contexts.

Findings

Before explicit reviewing of the dramatic-turn performances, some of the participants as actors as well as audience members in role-play dramatic turns were quick to blame the customer behavior as the principal cause for the service breakdown. The study’s exposition stresses prevention of negative dramatic turns follows from experiencing and coaching a wide variety of customer and server interactions – achieving “richness” in enactments.

Research limitations/implications

Research on service breakdown prevention needs to include field experiments on the efficacy of training programs for effective management of dramatic turns.

Practical implications

Training of service workers and service managers in experiencing/participating in dramatic turns is likely to be beneficial in reducing the severe adverse outcomes and unintended consequences of service breakdowns. Prevention, not only service failure recovery, needs to be an explicit focus in hospitality management training and assessment.

Social implications

This study suggests tools and procedures to reduce the instances of the need for service breakdown recoveries.

Originality/value

The study calls attention and contributes a way forward in managing dramatic turns in hospitality service contexts. The study provides a nascent configurational theoretical foundation of dramatic-turn propositions. Given the severity of financial costs and loss of brand/firm reputation following the occurrence of extreme dramatic turns, a research focus on service breakdown prevention is necessary.

Details

International Journal of Contemporary Hospitality Management, vol. 32 no. 2
Type: Research Article
ISSN: 0959-6119

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Article
Publication date: 16 October 2018

Zhong Wei, Guangming Song, Huiyu Sun, Qien Qi, Yuan Gao and Guifang Qiao

This paper aims to study the turning strategies for the bounding quadruped robot with an active spine and explore the significant role of the spine in the turning locomotion.

Abstract

Purpose

This paper aims to study the turning strategies for the bounding quadruped robot with an active spine and explore the significant role of the spine in the turning locomotion.

Design/methodology/approach

Firstly, the bounding gait combining the pitch motion of the spine with the leg motion is presented. In this gait, the spine moves in phase with the front legs. All the joints of the legs and spine are controlled by cosine signals to simplify the control, and the initial position and oscillation amplitude of the joints can be tuned. To verify the effectiveness of the proposed gait, the spine joints are set with different initial positions and oscillation amplitudes, and the initial position and oscillation amplitude of the leg joints are tuned to make the virtual model do the best locomotion in terms of the speed and stability in the simulation. The control signals are also used to control a real robot called Transleg. Then, three different turning strategies are proposed, including driving the left and right legs with different strides, swaying the spine in the yaw direction and combining the above two methods. Finally, these strategies are tested on the real robot.

Findings

The stable bounding locomotion can be achieved using the proposed gait. With the spine motion, the speed of the bounding locomotion is increased; the turning radius is reduced; and the angular velocity is increased.

Originality/value

A simple and flexible planning of the bounding gait and three turning strategies for the bounding quadruped robot are proposed. The effectiveness of the proposed bounding gait, along with the beneficial effect of the spine motion in the yaw direction on the turning locomotion is demonstrated with the computer simulations and robot experiments. This will be instructive for the designing and actuating of the other quadruped robots.

Details

Industrial Robot: An International Journal, vol. 45 no. 5
Type: Research Article
ISSN: 0143-991X

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