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Article
Publication date: 29 March 2011

Kirubakaran Dhandapani and Rama Reddy Sathi

The purpose of this paper is to present, a novel boost‐active clamp bridge single stage highfrequency zero voltage soft‐switching‐pulse width modulation (ZVS‐PWM…

Abstract

Purpose

The purpose of this paper is to present, a novel boost‐active clamp bridge single stage highfrequency zero voltage soft‐switching‐pulse width modulation (ZVS‐PWM) inverter, which converts the utility frequency AC power into highfrequency AC power with an embedded controller. This single stage highfrequency inverter is composed of a single‐phase diode bridge rectifier, a non‐smoothing filter, a boost‐active clamp bridge type ZVS‐PWM highfrequency inverter, and an induction‐heated load with planar type litz wire working coil assembly. Also, the paper discusses how to extend the soft‐switching operation ranges and improve power conversion efficiency.

Design/methodology/approach

The proposed converter is simulated and it is implemented using embedded controller.

Findings

It was found that the single stage highfrequency induction heating (IH) inverter using boosted voltage function can eliminate the DC and low‐frequency components of the working coil current and reduce the power dissipation of the circuit components and switching devices.

Originality/value

The paper shows that the PWM HF inverter is preferred for IH, since it has reduced switching losses and switching stresses. The paper can be extended to PC‐based wireless control, which can be part of a distributed control system in major industrial heating systems.

Details

Journal of Engineering, Design and Technology, vol. 9 no. 1
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 31 May 2019

Siddik Bozkurt and David Gligor

Although unfavorable pricing errors (UPEs) cost customers billions of dollars each year, research has not yet examined customers’ reactions to UPEs. This paper aims to…

Abstract

Purpose

Although unfavorable pricing errors (UPEs) cost customers billions of dollars each year, research has not yet examined customers’ reactions to UPEs. This paper aims to fill this gap by examining customers’ reactions to UPEs in terms of frequency, magnitude and the interaction between frequency and magnitude. Also, this study explores the moderated mediating role of price consciousness.

Design/methodology/approach

Three experimental studies were conducted to examine customers’ reactions to UPEs in terms of frequency, magnitude and the interaction between frequency and magnitude. PROCESS Model 6 and 84 along with multivariate regression analysis and MANOVA were used to test the hypotheses.

Findings

The results show that high-frequency and high-magnitude UPEs lead to increased perceived deception and dissatisfaction, resulting in a higher negative attitude toward the grocery store, decreased re-patronage intentions and increased negative word-of-mouth (NWOM). Also, results show that regardless of customers’ price consciousness level, customers display negative reactions when encountering UPEs.

Research limitations/implications

This paper only investigates UPEs in the brick and mortar setting; future studies should examine UPEs in different settings.

Practical implications

The findings show that UPEs can cause significant problems for grocery stores. Thus, managers should take precautionary measures (e.g. constantly checking shelves) to ensure that the advertised price and the checkout price match.

Originality/value

This paper represents the first attempt to empirically examine the relationship between UPEs frequency and magnitude, on the one hand, and perceived deception, dissatisfaction, customer attitude, re-patronage intentions, NWOM and price consciousness on the other.

Details

Journal of Consumer Marketing, vol. 36 no. 6
Type: Research Article
ISSN: 0736-3761

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Article
Publication date: 1 May 1993

V‐W. Mitchell and G.S. Prince

Since consumers are being provided with ever‐increasing amounts ofinformation, there is an increasing need to study the way in which theyhandle purchasing information…

Abstract

Since consumers are being provided with ever‐increasing amounts of information, there is an increasing need to study the way in which they handle purchasing information. Investigates the effect of buy‐frequency on one theory of consumer decision making: Perceived Risk Theory. Survey data from 100 consumers revealed that in general perceived risk decreased as buy‐frequency increased, but only for high‐value products and services and not as much as expected. High‐value services showed considerably less risk decrease as buy‐frequency increased than did high‐value products, possibly due to their heterogeneity. Experienced purchasers place more emphasis on pre‐purchase product trial and purchasing well‐known brands for high‐value goods and store image and brand loyalty for low‐value goods, than inexperienced purchasers. Discusses the implications for perceived risk measurement as well as retailing.

Details

International Journal of Retail & Distribution Management, vol. 21 no. 5
Type: Research Article
ISSN: 0959-0552

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Article
Publication date: 28 December 2020

Mathieu Gerber, Guillaume Callerant, Christophe Espanet, Farid Meibody-Tabar and Noureddine Takorabet

The purpose of this paper is to study the high-frequency impacts of fast switching wide-bandgap transistors on electronic and motor designs. The high-frequency power…

Abstract

Purpose

The purpose of this paper is to study the high-frequency impacts of fast switching wide-bandgap transistors on electronic and motor designs. The high-frequency power converters, dedicated to driving high-speed motors, require specific models to design predictively electronic and motors.

Design/methodology/approach

From magnetic and electric models, the high-frequency parasitic elements for both electronics and motor are determined. Then, high-frequency circuit models accounting for of parasitic element extractions are built to study the wide bandgap transistors commutations and their impacts on motor windings.

Findings

The results of the models, for electronics and motors, are promising. The high-frequency commutation cell study is used to optimize the layouts and to improve the commutation behaviours and performances. The impact of the switching speed is highlighted on the winding voltage susceptibility. Then, the switching frequency and commutation rapidity can be both optimized to increase the performance of motor and electronics. The electronic model is validated by experimentations.

Research limitations/implications

The method can be only applied to the existing motor and electronic designs. It is not taken into account in an automized global high-frequency optimizer.

Originality/value

Helped by magnetic and electric FEA calculations where the parasitic element extractions are performed. The switching frequency and commutation rapidity can be both optimized to increase the performance of motor and electronics.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 40 no. 2
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 2 January 2020

Abderahmane Marouf, Yannick Bmegaptche Tekap, Nikolaos Simiriotis, Jean-Baptiste Tô, Jean-François Rouchon, Yannick Hoarau and Marianna Braza

The purpose of this study illustrates the morphing effects around a large-scale high-lift configuration of the Airbus A320 with two elements airfoil-flap in the take-off…

Abstract

Purpose

The purpose of this study illustrates the morphing effects around a large-scale high-lift configuration of the Airbus A320 with two elements airfoil-flap in the take-off position. The flow around the airfoil-flap and the near wake are analysed in the static case and under time-dependent vibration of the flap trailing-edge known as the dynamic morphing.

Design/methodology/approach

Experimental results obtained in the subsonic wind tunnel S1 of Institut de Mécanique des Fluides de Toulouse of a single wing are discussed with high-fidelity numerical results obtained by using the Navier–Stokes multi-block (NSMB) code with advanced turbulent modelling able to capture the predominant instabilities and coherent structure dynamics. An explanation of the dynamic time-dependent grid deformation is provided, which is used in the NSMB code to simulate the flap’s trailing-edge deformation in the morphing configuration. Finally, power spectral density is performed to reveal the coherent wake structures and their modification because of the morphing.

Findings

Frequency of vibration and amplitude of deformation effects are investigated for different morphing cases. Optimal morphing regions at a specific frequency and a slight deformation were able to attenuate the predominant natural shear-layer frequency and to considerably decrease the width of the von Kármán vortices with a simultaneous increase of aerodynamic performances.

Originality/value

The new concept of future morphed wings is proposed for a large scale A320 prototype at the take-off position. The dynamic morphing of the flap’s trailing-edge is simulated for the first time for high-lift two-element configuration. In addition, the wake analysis performed helped to show the turbulent structures according to the organised eddy simulation model.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 2
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 11 February 2021

Yongxing Guo, Min Chen, Li Xiong, Xinglin Zhou and Cong Li

The purpose of this study is to present the state of the art for fiber Bragg grating (FBG) acceleration sensing technologies from two aspects: the principle of the…

Abstract

Purpose

The purpose of this study is to present the state of the art for fiber Bragg grating (FBG) acceleration sensing technologies from two aspects: the principle of the measurement dimension and the principle of the sensing configuration. Some commercial sensors have also been introduced and future work in this field has also been discussed. This paper could provide an important reference for the research community.

Design/methodology/approach

This review is to present the state of the art for FBG acceleration sensing technologies from two aspects: the principle of the measurement dimension (one-dimension and multi-dimension) and the principle of the sensing configuration (beam type, radial vibration type, axial vibration type and other composite structures).

Findings

The current research on developing FBG acceleration sensors is mainly focused on the sensing method, the construction and design of the elastic structure and the design of a new information detection method. This paper hypothesizes that in the future, the following research trends will be strengthened: common single-mode fiber grating of the low cost and high utilization rate; high sensitivity and strength special fiber grating; multi-core fiber grating for measuring single-parameter multi-dimensional information or multi-parameter information; demodulating equipment of low cost, small volume and high sampling frequency.

Originality/value

The principle of the measurement dimension and principle of the sensing configuration for FBG acceleration sensors have been introduced, which could provide an important reference for the research community.

Details

Sensor Review, vol. 41 no. 1
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 7 July 2020

Xiaolei Jiao, Jinxiu Zhang, Hongchao Zhao and Yong Yan

Bellows-type fluid viscous damper can be used to isolate micro vibration in high-precision satellites. The conventional model cannot describe hydraulic stiffness in the…

Abstract

Purpose

Bellows-type fluid viscous damper can be used to isolate micro vibration in high-precision satellites. The conventional model cannot describe hydraulic stiffness in the medium- and high-frequency domain of this damper. A simplified analytical model needs to be established to analyze hydraulic stiffness of the damping element in this damper.

Design/methodology/approach

In this paper, a bellows-type fluid viscous damper is researched, and a simplified model of the damping element in this damper is proposed. Based on this model, the hydraulic stiffness and damping of this damper in the medium- and high-frequency domains are studied, and a comparison is made between the analytical model and a finite element model to verify the analytical model.

Findings

The results show that when silicone oil has low viscosity, a model that considers the influence of the initial segment of the damping orifice is more reasonable. In the low-frequency domain, hydraulic stiffness increases quickly with frequency and remains stable when the frequency increases to a certain value; the stable stiffness can reach 106 N/m, which is much higher than the main stiffness. Excessive dynamic stiffness in the high-frequency domain will cause poor vibration isolation performance. Adding compensation bellows to the end of the original isolator may be an effective solution.

Practical implications

A model of the isolator containing the compensation bellows can be derived based on this analytical model. This research can also be used for dynamic modeling and vibration isolation performance analysis of a vibration isolation platform based on this bellows-type fluid viscous damper.

Originality/value

This paper proposed a simplified model of damping element in bellows-type fluid viscous damper, which can be used to analyze hydraulic stiffness in this damper and it was found that this damper showed stable hydraulic stiffness in the medium- and high-frequency domains.

Details

Engineering Computations, vol. 38 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 6 June 2016

Huong Le, Bridget Jones, Tandi Williams and Sara Dolnicar

The purpose of this paper is to provide novel insights into arts consumption behaviour and patterns of communication displayed by arts consumers using Peterson’s…

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Abstract

Purpose

The purpose of this paper is to provide novel insights into arts consumption behaviour and patterns of communication displayed by arts consumers using Peterson’s theoretical framework, and to identify differences in the use of communication channels across arts segments.

Design/methodology/approach

The authors conducted an a priori market segmentation study, with two variables serving as segmentation criteria, namely, the frequency of and the variety of arts events attended. The authors tested for differences in communication patterns.

Findings

Four segments were created: low-frequency univores, low-frequency multivores, high-frequency multivores and high-frequency omnivores. They differ in their communication patterns and online behaviours, including their online activities before and after attending arts events. Printed materials and e-mail newsletters were the most effective communication channel for raising awareness of all arts consumers.

Research limitations/implications

Understanding these communication patterns can help arts marketers to increase the attendance of low-frequency segments and broaden the variety of arts events attended by the univore and multivore segments. The generalisability of the findings is limited as the survey was conducted among online Australian arts consumers only.

Originality/value

The paper adds the dimension of arts consumption frequency to the taxonomy of omnivores and univores proposed by Peterson, which is based on the variety of consumed arts only. The paper contributes to communication and arts marketing literature by identifying key differences in communication patterns across segments of arts consumers and the most promising communication channels to engage them.

Details

Marketing Intelligence & Planning, vol. 34 no. 4
Type: Research Article
ISSN: 0263-4503

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Article
Publication date: 6 August 2020

Kilho Shin and Liliana Pérez-Nordtvedt

The purpose of this study is to investigate what type of knowledge enhances the frequency of strategic renewal for organizations operating in high velocity environments…

Abstract

Purpose

The purpose of this study is to investigate what type of knowledge enhances the frequency of strategic renewal for organizations operating in high velocity environments. It also investigates whether strategic renewal frequency is beneficial, rather than harmful in such environments.

Design/methodology/approach

The study followed a two-step data collection process involving pilot interviews and an on-site survey data collection procedure. The authors first conducted face-to-face pilot interviews with 16 fashion retailers lasting 30 min to 2 h. They then tested their hypotheses by using a sample of 152 South Korean fashion retailers, as the fashion industry is a prototypical high velocity environment.

Findings

Firms that have a higher rate of strategic renewal frequency outperform those with a lower one. Moreover, the frequency of strategic renewal mitigates the ill effects of lack of legitimacy not imbued by a franchisor’s backing. Finally, firms can increase the frequency of their strategic renewal efforts by accessing knowledge from their main customers more efficiently.

Originality/value

The results of this study provide a refined picture of the role of knowledge acquisition efficiency and strategic renewal frequency in the pursuit of competitive advantage in high velocity environments.

Details

Journal of Knowledge Management, vol. 24 no. 9
Type: Research Article
ISSN: 1367-3270

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Article
Publication date: 29 November 2021

Guangyuan Wu, Haitao Zhang, Junfeng Sun and Tengjiang Yu

In order to evaluate the rheological properties of asphalt more comprehensively and effectively, and to explore and discuss the practicability of relevant models in the…

Abstract

Purpose

In order to evaluate the rheological properties of asphalt more comprehensively and effectively, and to explore and discuss the practicability of relevant models in the evaluation of the rheological properties of asphalt.

Design/methodology/approach

Based on the rheological and viscoelastic theories, temperature scanning, frequency scanning and multiple stress creep recovery (MSCR) tests of different modified asphalt were carried out by dynamic shear rheometer (DSR) to obtain relevant viscoelastic parameters and evaluate the high temperature properties of different modified asphalt. Based on the time-temperature equivalence principle, the main curve was constructed to study the viscoelastic properties of asphalt in a wider frequency domain. The main curve was fitted with the CAM model, and the rheological properties of different modified asphalt were evaluated through the analysis of model parameters. The creep stiffness and creep velocity of different modified asphalt were obtained through the rheological test of bending beam (BBR), and the low-temperature performance of different modified asphalt was analyzed by using Burgers model to fit the creep compliance.

Findings

The results show that the high temperature rheological properties of several modified asphalt studied in the test are ranked from best to worst as follows: PE modified asphalt > SBS modified asphalt > SBR modified asphalt. Short-term aging can improve the high temperature performance of asphalt, and different types of modifiers can promote or inhibit this improvement effect. Based on BBR test and Burgers model fitting analysis, SBR modified asphalt has the best low temperature performance, followed by SBS modified asphalt, while PE modified asphalt has poor low temperature performance, so it is not suitable to be used as road material in low temperature area.

Originality/value

Combined with effective evaluation methods, the rheological properties of asphalt at different temperatures and angles were systematically evaluated, and the evolution of rheological properties of asphalt characterized by model parameters was further analyzed by advanced model simulation.

Details

Journal of Engineering, Design and Technology , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1726-0531

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