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1 – 10 of 85Lufeng Zhang and Kai Wang
The purpose of this paper is to investigate the electromagnetic performances of the permanent magnet linear synchronous machines (PMLSM) with sine and third harmonic (SIN + 3rd…
Abstract
Purpose
The purpose of this paper is to investigate the electromagnetic performances of the permanent magnet linear synchronous machines (PMLSM) with sine and third harmonic (SIN + 3rd) shaping mover in comparison with the PMLSM with sine (SIN) shaping mover and conventional shaping mover.
Design/methodology/approach
The optimal amplitude of the injected third harmonic to re-shape the SIN + 3rd shaping permanent magnet (PM) for maximizing the thrust force is analytically derived and confirmed by finite element method (FEM). Furthermore, the PM edge thickness, the pole arc to pole pitch ratio and the tooth to slot ratio are optimized. It is found that the optimal amplitude of the injected third harmonic is one-sixth of the fundamental one, the optimal PM edge thickness, the pole arc to pole pitch ratio and the tooth to slot ratio are 0, 0.85 and 0.5 mm, respectively. In addition, the electromagnetic performances are analyzed and quantitatively compared for the PMLSM with SIN + 3rd shaping mover, SIN shaping mover and conventional shaping mover.
Findings
The average thrust force and efficiency of the PMLSM with SIN + 3rd shaping mover are improved significantly, while the thrust ripple is not increased, comparing to those of the PMLSM with SIN shaping mover. Meanwhile, the thrust ripple is lower than that of the conventional shaping mover.
Research limitations/implications
The purely sinusoidal currents are applied in this analysis and the influences of harmonics in the current on electromagnetic performances are not considered.
Originality/value
This paper presents a PMLSM with SIN + 3rd shaping mover to improve the thrust force and efficiency without increasing the thrust ripple, considering the effects of the amplitude of the injected third harmonic to re-shape the SIN + 3rd shaping PM, the PM edge thickness, the pole arc to pole pitch ratio and the tooth to slot ratio.
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Yihua Yao, Yi Chen, Qinfen Lu, Xiaoyan Huang and Yunyue Ye
Permanent magnet linear synchronous machines (PMLSMs) have large thrust ripple due to the longitudinal end effect caused by the finite length of the armature compared with rotary…
Abstract
Purpose
Permanent magnet linear synchronous machines (PMLSMs) have large thrust ripple due to the longitudinal end effect caused by the finite length of the armature compared with rotary machines. The purpose of this paper is to analyze the influence of electric loading on thrust ripple performances based on a 12 slots/14 poles (12S/14P) PMLSM. Furthermore, the method of skewed PMs to reduce thrust ripple is investigated based on multi slices 2D finite element (FE) models.
Design/methodology/approach
The thrust ripple of PMLSM under open-circuit condition results from the slotting and the longitudinal end effects. Therefore, periodical model has been designed to clarify the effect of the longitudinal end effect. Under on-load condition, the thrust ripple increases and exhibits an effective component of thrust force. To analyze the thrust ripple under on-load condition, frozen permeability (FP) technique is employed. In addition, the method of skewed PMs is analyzed in this paper to obtain more smooth thrust force performance. The effectiveness of skewing accounting for skew angles, step skew numbers and slot/pole number combinations was highlighted.
Findings
The longitudinal end effect dominates the thrust ripple of PMLSM in both cases, i.e., open-circuit and on-load conditions. Under on-load condition, the second harmonic component of thrust ripple related to flux linkage harmonics increases significantly. Moreover, the effectiveness of skewed PMs is largely reduced with the increase of magnetic saturation. At last, a proper skew angle and step skew number are obtained for the conventional PMLSM with fractional-slot winding.
Originality/value
By 60 electrical degrees and two or three step skewed PMs, the thrust ripple can be decreased to a tolerable limite for conventional PMLSM. The thrust ripple harmonics contributed by longitudinal end effect and flux linkage harmonics are analyzed, respectively, which is beneficial to exploring other techniques such as adding end auxiliary teeth to obtain lower thrust force pulsation.
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Before COVID-19 pandemic, translation students in higher education attended courses on computer-assisted translation to acquire operational knowledge of professional software…
Abstract
Purpose
Before COVID-19 pandemic, translation students in higher education attended courses on computer-assisted translation to acquire operational knowledge of professional software, without experiencing collaborative/interactive learning. In few European universities skills labs were introduced to offer fieldwork-like activities, but without shared modelling standards and mainly held in presence for few consecutive days. As the COVID-19 pandemic further deprived students of crucial educational experiences, the purpose of this paper is to present an online collaborative learning environment exploiting a customised combination of information and learning applications the students already experienced during the pandemic to smoothen their learning curve and increase the educational effectiveness.
Design/methodology/approach
A multi-framework methodology to build and operate a computer-supported online collaborative skills lab for translation students is proposed. Reference standards and guidelines are leveraged to provide participants with a common knowledge ground, to activate the computer-supported collaborative learning perspective, and to ensure an appropriate simulation fidelity.
Findings
An end-to-end implementation of the proposed approach along with educational effectiveness analysis performed via complementary assessment strategies is presented. Achieved outcomes highlight significant participation rate, consistent improvement in technical and soft skills at both individual and collective levels, and clear activation of collaborative learning dynamics.
Practical implications
Every master degree in translation teaching can adopt this approach by complying with the proposed guidelines.
Originality/value
The proposed multi-framework approach is novel and applied to a teaching sector where it is highly needed to fill a pre-existing gap.
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J.L.G. Janssen, J.J.H. Paulides and E.A. Lomonova
The purpose of this paper is to present novel analytical expressions which describe the 3D magnetic field of arbitrarily magnetized triangular‐shaped charged surfaces. These…
Abstract
Purpose
The purpose of this paper is to present novel analytical expressions which describe the 3D magnetic field of arbitrarily magnetized triangular‐shaped charged surfaces. These versatile expressions model that the field of triangular‐shaped permanent magnets (PMs) are very suitable to model skewed slotless machines.
Design/methodology/approach
The analytical 3D surface charge method is normally used to provide field expressions for PMs in free space. In this paper, the analytical surface charge integrals are analytically solved for charged right‐triangular surfaces. The resulting field is compared with that obtained by finite element modeling (FEM) and subsequently applied in two examples.
Findings
The comparison with FEM shows that the 3D analytical expressions are very accurate and exhibit very low‐numerical noise. These fast‐solving versatile expressions are therefore considered suitable to model triangular‐shaped or polyhedral‐shaped PMs.
Research limitations/implications
The surface charge method assumes that the relative permeability is equal to 1 and therefore soft‐magnetic materials need to be modeled using the method of images. The PMs are assumed to be ideal in terms of homogeneity, magnetization vector, permeability, demagnetization, and geometrical tolerances.
Practical implications
Many applications, such as the subclass of slotless synchronous linear actuators with a skewed PM structure and planar magnetic bearings, are very suitable to incorporate this modeling technique, since it enables the analysis of a variety of performance data.
Originality/value
As an addition to the common 3D analytical field expressions for cuboidal or cylindrical PMs, this paper presents novel expressions for magnets having triangular surfaces.
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Erkki K. Laitinen and Tarmo Kadak
The purpose of this paper is to use the logical chain of key factors (KFs) to explain the success of performance management systems (PMS) and corporate performance.
Abstract
Purpose
The purpose of this paper is to use the logical chain of key factors (KFs) to explain the success of performance management systems (PMS) and corporate performance.
Design/methodology/approach
The authors use the strength of the KFs chain to capture PMS success. First, the authors assume that perceived environmental uncertainty (PEU) is positively associated with the strength (H1). The higher the PEU, the stronger is the chain as a response to uncertainty. Second, the authors assume that the strength improves performance (H2) but third, that the impact of the strength is negatively moderated by competition (H3). Fourth, the authors assume that this improvement leads to superior corporate performance (H4). The research model is tested by applying the partial least squares method for a sample of 61 Estonian and Finnish firms.
Findings
Empirical evidence shows that PEU is negatively correlated to the strength of the chain but when controlled for a set of control variables, the path coefficient is positive. The strength of the chain is positively associated with improvement in performance. The impact of the strength of the chain on financial performance is negatively moderated by competition. The improvement in performance is positively associated with the attainment level of strategic goals. The improvement in non-financial performance does not significantly affect corporate profitability.
Practical implications
The levels of PEU and competition should be taken into the account when designing, adjusting and assessing the PMS of organization.
Originality/value
The authors give explanation why evidence about the effects of PMS on the performance of the firm is mixed.
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Tarmo Kadak and Erkki K. Laitinen
The assessment of the success of Performance Management Systems (PMS) is difficult because there are many success factors, they are mutually dependent on each other, and located…
Abstract
Purpose
The assessment of the success of Performance Management Systems (PMS) is difficult because there are many success factors, they are mutually dependent on each other, and located at different hierarchical levels of an organization. Therefore, there is a need to describe the complete logical chain, which makes PMS successful for an organization and to find out a comprehensive list of key factors (KF) affecting the success of PMS. The objective of this research paper is to develop a method to assess success of a PMS based on a logical chain of 14 KF.
Methodology/approach
The research first develops a logical chain based on the 14 KFs on the basis of prior studies and then carries out a survey about these KFs (15 check points) of PMS and their connection to organizational performance for a small sample of firms from two EU countries.
Findings
There are next findings of this study which indicate following: KFs of PMS affect organizational performance; successful PMS improves organizational performance; PMS is successful for the organization when the completeness of the logical chain in PMS is high.
Practical implications
The practical contribution of this study is that findings show that firms can assess their own PMSs and compare their check point values against the values of successful PMS group. This kind of analysis indicates directly improvement potential for the different check points in PMS.
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The purpose of this paper is to investigate the influence of firm size on the performance measurement system (PMS) design in the service context. Focusing on several aspects of…
Abstract
Purpose
The purpose of this paper is to investigate the influence of firm size on the performance measurement system (PMS) design in the service context. Focusing on several aspects of the PMS design, i.e. the significance of the information attributes (PMS attributes), the way the system is used (PMS use) and the measurement mechanisms (PMS mechanisms), the significance of firm size was explored.
Design/methodology/approach
Data were collected by administering a mail questionnaire survey to the top-level management of private service firms operating in Malaysia. The sampling frame was based on information provided by the Department of Statistics, Malaysia, and the Central Bank of Malaysia. An extensive search of directories/portals was undertaken to compile the mailing list of each service sector. Samples were randomly selected from the list using proportionate stratified sampling.
Findings
The findings suggest that firm size influences the way their PMS was designed. The larger the firm size, the greater the emphasis placed on designing a sophisticated PMS. The results also indicate that size has a greater effect on the PMS of professional service firms, compared to mass service firms.
Research limitations/implications
The limitation of the study pertains to the objective to observe the practice among service organizations on a broad scale, thus limiting the ability to comprehend the reasons for the findings.
Practical implications
To the PMS designers and users, the understanding may offer a basic knowledge for designing and developing an effective and efficient PMS to be a useful tool in facing the continuous growth and stringent service market competition.
Originality/value
Rather than restricted to a specific service industry, the study removes the traditional perception that insists that each service activity and problem is unique, by examining the practice of PMS among service firms from a broad-based perspective. The focus is on the commonalities that exist between them in facing the consequences of the service revolution.
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Amizawati Mohd Amir, Nik Nazli Nik Ahmad and Muslim Har Sani Mohamad
The purpose of this paper is to make a contribution to the performance measurement system (PMS) literature by concentrating on the service context. Providing a Malaysian…
Abstract
Purpose
The purpose of this paper is to make a contribution to the performance measurement system (PMS) literature by concentrating on the service context. Providing a Malaysian perspective on PMS design, the study aims to identify the desirable PMS attributes that are perceived to be important for the service sector.
Design/methodology/approach
Data were collected by administering a mail questionnaire survey to top‐level management of private service firms operating in Malaysia. The sampling frame was based on information provided by the Department of Statistics, Malaysia, and the Central Bank of Malaysia. An extensive search of directories/portals was undertaken to compile the mailing list of each service sector. Samples were randomly selected from the list using proportionate stratified sampling.
Findings
The findings suggest that service firms placed greater emphasis on elements of performance evaluation, benchmarking, timeliness and precise PMS information. Differentiation strategy and intensity of competition are the most prominent factors that influence the choice of PMS attributes.
Research limitations/implications
The limitation of the study pertains to the low response from the foreign‐owned service firms operating in Malaysia, thus limiting the generalisability of the findings to local‐owned firms.
Practical implications
To service managers, the evidence demonstrates the relevance of PMS in service firms, where the greater strategic uncertainty and intensity of market competition requires greater reliance on contemporary PMS attributes.
Originality/value
The evidence indicates the applicability of PMS in managing both professional service and mass service firms that removed the traditional view that all service activities are unique.
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Anderson Betti Frare and Ilse Maria Beuren
The purpose of this study is to investigate the effects of comprehensive performance measurement systems (PMS), role clarity and strategic flexibility on the individual creativity…
Abstract
Purpose
The purpose of this study is to investigate the effects of comprehensive performance measurement systems (PMS), role clarity and strategic flexibility on the individual creativity of founders/managers of startups.
Design/methodology/approach
The research population comprises 611 Brazilian startups in the e-commerce, retail and wholesale segments. One owner/manager of each startup was contacted by the survey, obtaining 91 valid responses. For data analysis, symmetric and asymmetric techniques were applied, respectively: partial least squares-structural equation modeling and fuzzy-set qualitative comparative analysis.
Findings
The findings show that the comprehensive PMS is an important predictor of individual creativity, role clarity and strategic flexibility. Role clarity has a direct effect on creativity and promotes partial mediation between comprehensive PMS and creativity. Comprehensive PMS and role clarity are of great importance and have high performance in favor of creativity, while strategic flexibility has high performance, but is of low importance. Several causal combinations promote high individual creativity.
Practical implications
It offers founders/managers an insight into the aspects that are worth of efforts to foster individual creativity in their startup.
Originality/value
The key contribution of the study is that the comprehensive PMS, which includes financial, non-financial and other measures for product and process innovation, can directly and indirectly (through role clarity) influence individual creativity.
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The purpose of the paper is to model, analyze and control a new flux‐controllable stator‐permanent‐magnet brushless (PMBL) motor with skewed rotor.
Abstract
Purpose
The purpose of the paper is to model, analyze and control a new flux‐controllable stator‐permanent‐magnet brushless (PMBL) motor with skewed rotor.
Design/methodology/approach
A new flux‐controllable stator‐PMBL motor with skewed rotor is presented. The key of the proposed motor is to incorporate both direct current field windings and permanent magnets in the stator. By using a 2D multi‐slice finite element model, the electromagnetic performances such as flux linkage, self‐inductance and back‐EMF are obtained. To minimize the torque ripple, a vector control strategy is applied to the stator‐PMBL motor drive for the first time.
Findings
Some encouraging experimental results such as lower torque ripple and faster speed transients are achieved. It is shown that the three‐phase flux‐controllable stator‐PMBL motor, when properly designed and controlled, is an interesting candidate for traction drive systems especially for electrical vehicle operation.
Originality/value
The control method can also contribute the other type of stator‐PMBL machines to realize the low torque ripple.
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