Implementation of the sliding-line technique in a MEC model of a linear bistable actuator

Author(s):  
Shinara Utegenova

Purpose The aim of this study is to investigate the implementation of the sliding-line technique (SLT) in a generic two-dimensional (2D) nonlinear adaptive magnetic equivalent circuit (MEC) model predicting the electromagnetic force evolution of a linear bistable electromagnetic actuator technology. Design/methodology/approach The developed MEC model considers the saturation effect and the auto-adjustability of the spatial discretisation. The connection between static and mobile zones is ensured by an approach known as “air-gap sliding-line technique”, which is widely used for rotary electric motor models. To the best of the author’s knowledge, that is the first time that the SLT is implemented on an electromagnetic structure with linear motion. Findings It was found that, in case of a linear actuator with a relatively small working stroke, the implementation of the SLT could lead to some non-negligible inaccuracies. Originality/value To solve the above-mentioned problem, it was proposed to investigate the implementation of a single SLT vs double SLT. The results of the MEC models were compared with the 2D finite-element analysis (FEA) as well as with the experimental test results. The developed semi-analytical models can be easily adapted to other topologies of linear electromagnetic machines.

2019 ◽  
Vol 37 (1) ◽  
pp. 134-142
Author(s):  
Alberto Bueno-Guerrero

Purpose This paper aims to study the conditions for the hedging portfolio of any contingent claim on bonds to have no bank account part. Design/methodology/approach Hedging and Malliavin calculus techniques recently developed under a stochastic string framework are applied. Findings A necessary and sufficient condition for the hedging portfolio to have no bank account part is found. This condition is applied to a barrier option, and an example of a contingent claim whose hedging portfolio has a bank account part different from zero is provided. Originality/value To the best of the authors’ knowledge, this is the first time that this issue has been addressed in the literature.


2018 ◽  
Vol 120 (8) ◽  
pp. 1915-1928
Author(s):  
Judith Müller-Maatsch ◽  
Johannes Jasny ◽  
Katharina Henn ◽  
Claudia Gras ◽  
Reinhold Carle

Purpose The purpose of this paper is to provide insight into the consumers’ perception of natural and artificial food colourants. Furthermore, attitudes towards the application of carmine, being technically important and ubiquitously used to impart red shades, are assessed and analysed. Originating from insects, carmine is considered as natural but may arouse disgust. Design/methodology/approach In total, 625 individuals were surveyed using an online, self-administered questionnaire to represent a broad cross-section of the German population. Findings Independent of their origin, the application of colourants was rejected by 57.0 per cent of the interviewees. In total, 31.8 per cent of the participants stated a neutral attitude, while only 11.2 per cent expressed a positive notion. Most respondents preferred colourants from natural sources to artificial ones. While consumers perceive natural food colourants composed of genuine plant pigments positively, 61.6 per cent of respondents disliked the application of animal-derived colourants, 24.8 per cent of them did neither reject nor like it, and only 13.6 per cent of the interviewees stated a positive attitude towards them. The findings of this paper further indicate consumers’ preference for colourants to be either artificial or plant-derived rather than carmine. Food colourants are being rejected, possibly due to misleading information and confusing labelling. Consequently, information about carmine, including its origin and production, did not increase the aversion to products that are dyed with it, but increased their acceptance. Originality/value This study outlines consumer perception and attitudes towards food colourants. For the first time, the findings of this paper report the effect of revealing information about an additive, which initially aroused disgust, and its influence on consumer perception.


2016 ◽  
Vol 36 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Hamid Yilmaz ◽  
Mustafa Yilmaz

Purpose – Within team-oriented approaches, tasks are assigned to teams before being assigned to workstations as a reality of industry. So it becomes clear, which workers assemble which tasks. Design/methodology/approach – Team numbers of the assembly line can increase with the number of tasks, but at the same time, due to physical situations of the stations, there will be limitations of maximum working team numbers in a station. For this purpose, heuristic assembly line balancing (ALB) procedure is used and mathematical model is developed for the problem. Findings – Well-known assembly line test problems widely used in the literature are solved to indicate the effectiveness and applicability of the proposed approach in practice. Originality/value – This paper draws attention to ALB problem in which workers have been assigned to teams in advance due to the need for specialized skills or equipment on the line for the first time.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jeannette Strickland

Purpose This paper aims to build on Fred Beard’s study of the world’s archives to identity historical advertising and marketing ephemera, published in this journal in 2018, by focussing on resources available in Europe to augment his survey. Design/methodology/approach Online searching, supplemented by literature emanating from the business archive sector, led to the identification of 177 repositories or online sites in Europe holding advertising and marketing archives of significance for researchers. These are set out in two accompanying tables. Findings A wide diversity of European archives that are open to researchers is revealed in this paper. Many are the archives of the business themselves, but a number of collecting repositories are also listed, brought together for the first time. Research limitations/implications This paper focusses solely on Europe but does not claim to be comprehensive, as the study was time-limited and readers will, no doubt, know of resources that the author has missed. The findings relate mostly to Western Europe, so there is scope for further study to encompass archives in the former eastern bloc. Exploration of sources in Africa, Asia and Latin America would further supplement Beard’s original study. Originality/value This research brings together the broadest list of advertising and marketing sources open to researchers in Europe published to date. As Beard’s focus was more on the Americas, this examination redresses the balance with an array of European sources which, it is hoped, will contribute to the greater use of many little-known or under-researched resources by researchers across the world.


2018 ◽  
Vol 32 (5) ◽  
pp. 23-25 ◽  
Author(s):  
Lucie Cuvelier

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings An operative approach is described that is designed to structure the debriefing along three axes. Practical implications The paper provides strategic insights and practical thinking that have influenced some of the world’s leading organizations. Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.


2018 ◽  
Vol 22 (4) ◽  
pp. 348-363
Author(s):  
Chang-soo Lee ◽  
Mikyung Yun

Purpose The purpose of this paper is to document for the first time the vertical specialization structure of the global pharmaceutical value chain. Design/methodology/approach The paper adopts Wang et al.’s (2013) gross exports decomposition method to trace foreign values in bilateral trade between major pharmaceutical producers, using the 2014 WIOT database. Findings The paper shows that as in other sectoral value chains, the pharmaceutical value chain is heavily regional. The paper identifies a strong European regional value chain, and a less intensive, Asian regional value chain. Korea is positioned in the middle of the Asian value chain, and is connected to the European regional value chain as a second-tier supplier. Originality/value The paper documents the vertical specialization structure of the global pharmaceutical value chain through gross exports decomposition method, making use of the World Input–Output Table Database 2014 which disaggregates pharmaceuticals in its industry classification for the first time.


2016 ◽  
Vol 34 (4) ◽  
pp. 651-665 ◽  
Author(s):  
Md. Emran Hossain ◽  
S.M. Zabed Ahmed

Purpose This paper aims to investigate the use of smartphones for academic purposes by students at Dhaka University, the top-ranked university in Bangladesh. Design/methodology/approach Students currently using smartphones answered a questionnaire survey, which focused on whether or not students used smartphones for academic works and, if so, for what purposes they used them and their opinion on the advantages of using smartphones for academic purposes. Descriptive statistics were used to analyze demographic and academic characteristics of the students in relation to their smartphone usage. Non-parametric analyses were performed using Mann–Whitney and Kruskal–Wallis tests to compare between students’ demographic and academic variables and their opinion on the advantages of academic use of smartphones. Findings The findings indicate that a vast majority of university students used smartphones for academic purposes. They, on average and across the board, had a positive perception toward academic use of smartphones. Although there were some differences in terms of gender, age, place of origin and duration of smartphone use, these differences were largely due to fact that a smartphone is a relatively new addition to the life of most students who participated in this study. Originality/value Research investigating the academic use of smartphones in the perspective of developing countries is virtually non-existent. This is the first time an effort has been made to examine the use of smartphones by a large sample of university students in Bangladesh.


2014 ◽  
Vol 10 (2) ◽  
pp. 135-154 ◽  
Author(s):  
Ifigeneia Douvitsa ◽  
Demosthenis Kassavetis

Purpose – The aim of this article is to investigate the organization of water cooperatives in Greece for the first time, as promoted by a spontaneous social mobilization called Initiative 136. The above attempt appears as an alternative proposition as opposed to the state-driven full privatization of EYATH S.A. Design/methodology/approach – This article presents previous work on water cooperatives and the negative effects of water privatization worldwide, relating it to water privatization in Greek reality through the prism of the current recession. Findings – While full privatization under the pressure of the economic crisis is very likely to yield significantly negative results, a transformation into a water cooperative might provide a viable solution. Research limitations/implications – Water cooperatives provide a solution for water distribution that is friendly for the consumer, the society and the environment. Practical implications – Application of a cooperative method of water provision in Greece could be a springboard for the use of the model in other areas. Originality/value – The article evaluates the privatization and cooperativization attempt of EYATH S.A. based on previous related research and considering Greece ' s current conditions.


2019 ◽  
Vol 18 (1) ◽  
pp. 71-94
Author(s):  
Gerasimos Rompotis

PurposeA well-documented pattern in the literature concerns the outperformance of small-cap stocks relative to their larger-cap counterparts. This paper aims to address the “small-cap versus large-cap” issue using for the first time data from the exchange traded funds (ETFs) industry.Design/methodology/approachSeveral raw return and risk-adjusted return metrics are estimated over the period 2012-2016.FindingsResults are partially supportive of the “size effect”. In particular, small-cap ETFs outperform large-cap ETFs in overall raw return terms even though they fail the risk test. However, outperformance is not consistent on an annual basis. When risk-adjusted returns are taken into consideration, small-cap ETFs are inferior to their large-cap counterparts.Research limitations/implicationsThis research only covers the ETF market in the USA. However, given the tremendous growth of ETF markets worldwide, a similar examination of the “small vs large capitalization” issue could be conducted with data from other developed ETF markets in Europe and Asia. In such a case, useful comparisons could be made, so that we could conclude whether the findings of the current study are unique and US-specific or whether they could be generalized across the several international ETF markets.Practical implicationsA possible generalization of the findings would entail that profitable investment strategies could be based on the different performance and risk characteristics of small- and large-cap ETFs.Originality/valueThis is the first study to examine the performance of ETFs investing in large-cap stock indicesvis-à-visthe performance of ETFs tracking indices comprised of small-cap stocks.


Author(s):  
Erich Schmidt ◽  
Wolfgang Paradeiser ◽  
Fadi Dohnal ◽  
Horst Ecker

PurposeAn overview is given on design features, numerical modelling and testing of a novel electromagnetic actuator to achieve a controllable stiffness to be used as a device for parametric stiffness excitation.Design/methodology/approachIn principle, the actuator consists of a current driven coil placed between two permanent magnets. Repellent forces are generated between the coil and the magnets, centering the coil between the two magnets. The 2D finite element analyses are carried out to predict the forces generated by this arrangement depending on coil current and coil position. Force measurements are also made using the actual device.FindingsActuator forces as predicted by the finite element analyses are in excellent agreement with the measured data, confirming the validity of the numerical model. Stiffness of the actuator is defined as the increase of force per unit of coil displacement. Actuator stiffness depends linearly on the coil current but in a nonlinear manner on the coil displacement. The performance of the actuator is sufficient to demonstrate the effect of a so‐called parametric anti‐resonance on a test stand.Research limitations/implicationsAlthough the performance of the actuator is satisfactory, there is potential for further improvement of the actuator design.Originality/valueThis paper reports for the first time on an electromechanical device to create a time‐periodic stiffness variation to be used for research in the field of parametrically excited mechanical systems. The device is used to prove experimentally an effect to suppress mechanical vibrations which has been studied so far only in theoretical studies.


Sign in / Sign up

Export Citation Format

Share Document