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The purpose of this paper is to simulate a pseudo direct drive (PDD) by using permanent magnet arrays.

A 2D finite element model of the PDD was built. The static magnetic torque on air-gaps was obtained by Coulomb’s virtual work method using Ansys Maxwell software. To simulate the relative movement between input rotor and output rotor, two movement bands were applied.

The PDD’s torque relation was proved. The PDD simulated presents low cogging torque.

The manufacturing steps and materials applied in a construction of a coaxial magnetic gear, PDD’s main component, are presented.

The value of this paper is to present the numerical techniques applied to simulate a PDD and the manufacturing steps and materials applied in a construction of a coaxial magnetic gear.

The purpose of this paper is to investigate the transient performance of an induction machine coupled with a magnetic gear for industrial applications with low speed and high torque requirements. This new solution increases mechanical reliability and does not require maintenance and lubrication. The main objective is to study the direct-on-line starting ability of the electrical machine and its stability regarding a sudden change for the load torque.

A nonlinear analytical model for the induction machine and the magnetic gear is first developed. The model is then linearized around an operating point to obtain the transfer function between the load angle and the electromagnetic torque from which an analytical expression for the mechanical resonant frequency is obtained.

It is shown that the direct on-line starting is possible, if the moment of inertia of the load is not greater than a maximum value. Moreover, it is demonstrated that this new system present inherent overload protection.

A new high-performance direct-on-line starting electrical machine is proposed to achieve high torque at low speed without mechanical gear to improve reliability and reduce maintenance.

This study aims to extract an analytical model for five-phase fault-tolerant permanent-magnet vernier machines (FTPMVMs) based on the analytical solution of Maxwell’s equations, which has some advantages than the finite element model.

FTPMVMs enhance the torque density by combining the vernier characteristics and the fault-tolerant feature. The principle operation of FTPMVMs is discussed based on the magnetic field modulation due to both permanent magnets and armature current. The analytical solution of the magnetic vector potential in each sub-region is obtained based on the sub-domain technique.

According to the calculated magnetic vector potential, the magnetic flux density, torque, self- and mutual inductance and back-electromotive force are calculated. The FEM is used to validate the results obtained from the proposed analytic model.

Two-dimensional analytical method is used to obtain the electromagnetic model of FTPMVMs.

The purpose of this research is to achieve a novel magnetic nutation drive for an industry robotic wrist reducer.

A novel magnetic nutation drive is proposed, and the structure and principle of the designed magnetic nutation drive are described in this study. Three-dimensional finite element analysis is used to compute the magnetic and torque of the magnetic nutation drive. Furthermore, a prototype of this novel magnetic nutation drive device is developed with 3D printing technology and tested to verify the feasibility of the proposed structure and principle.

The simulation and experimental results indicated that the proposed magnetic nutation drive device could meet the desired specifications, and that this novel magnetic nutation drive device successfully realized the non-contact transmission ratio of 105:1 required for a robotic wrist reducer.

This novel magnetic nutation drive is low-cost and easy to make and use, and which provides the non-contact transmission ratio of 105:1 required for a robotic wrist reducer.

For the first time, this research applies the permanent magnet drive technology to nutation drive and puts forward a new non-contact nutation drive mode. The novel drive mode can solve some problems of the traditional mechanical contact nutation drive, such as vibration, friction loss, mechanical fatigue and necessity of lubrication. The proposed non-contact nutation drive device can achieve a high reduction ratio with compact structure and can be suitable for industry application.

Early magnetic-geared motors have a high transmission torque density. However, the torque due to the coil is low because the permanent magnets in the stator become a large magnetic resistance when the current is applied to the coil. The purpose of this paper is to propose magnetic-geared motors which have a high transmission torque density and torque due to the coil. In addition, the proposed magnetic-geared motors are compared with past magnetic-geared motors and the effectiveness is verified by using finite element analysis.

A new magnetic-geared motor which has permanent magnets in the stator slot are proposed. The torque due to the coil increases by removing permanent magnets at the tip of the stator of past magnetic-geared motors. The permanent magnets placed in the stator slots are all magnetized to the outward direction and then the stator teeth are all magnetized to the inward direction. The maximum transmission torque and torque constant are compared.

The proposed magnetic-geared motor has a slightly smaller maximum transmission torque than the early magnetic-geared motors. However, the maximum transmission torque of the proposed magnetic-geared motor is high enough for practical uses. The torque due to the coils is higher than the early magnetic-geared motors.

The proposed magnetic-geared motor has originalities in its structure, especially in the permanent magnets in the stator slots.

The purpose of this paper is to examine the impact of market timing and pseudo market timing on equity issuance decisions of IPOs in an emerging economy – India. Indian new issues market provides a perfect setting to test market timing against pseudo market timing due to two reasons. First, the US literature shows that most underpriced IPOs are highly overvalued and in India, the authors have the evidence of underpricing of IPOs. But whether Indian IPOs are overvalued or not it is yet to be tested. Second, majority of IPOs were issued in India only after the 1991 economic reforms which may signal the evidence for pseudo market timing hypothesis.

The authors use direct test to examine the impact of market timing and pseudo market timing variables on the IPO activity. The direct tests of market timing and pseudo market timing hypotheses are based on the positive relation of market timing variables and market conditions variables with IPO activity. The authors examine the long-run performance of IPOs by using the calendar-time regression approach to test market timing against pseudo market timing. This serves as indirect test of market timing and pseudo market timing. Evidence of market timing using indirect test shows that there is a decline in the long-run stock performance of IPOs.

The results show that in India, firms issue equity not just due to market conditions but they also issue equity in order to time the market. The results of market timing are also supported by the calendar-time approach results. However, the authors find that the evidence of market timing is stronger for hot issue markets as compared to cold issue markets.

This is the first study to comprehensively examine market timing and pseudo market timing using direct and indirect tests for an emerging market context.

The purpose of this paper is to propose a magnetic‐geared motor with permanent magnets only on the high‐speed rotor as a solution to the problems of magnetic gears. Magnetic gears have some advantages such as no mechanical loss and maintenance‐free operation that are not observed in conventional mechanical gears. Furthermore, they have inherent overload protection. A novel structure which the magnetic gear is integrated with the brushless motor (magnetic‐geared motor) was proposed by Atallah et al. This magnetic‐geared motor is based on the magnetic gear which consists of a high‐ and low‐speed rotor, and a stator. Although this magnetic‐geared motor has a high‐torque density, problems with manufacturing and cost exist because multi‐pole permanent magnets are mounted on the high‐speed rotor and stator.

A magnetic‐geared motor with permanent magnets only on the high‐speed rotor was proposed and its operational principle was described. The cogging torque characteristics were mathematically formulated and the authors ascertained that the cogging torque contains components of multiples of 60th order. In order to verify the order of the cogging torque, the 3‐D finite element method analysis was conducted and measurements on a prototype were carried out.

The 60th component and its multiples were observed in the computed and measured cogging torque waveform. However, the cogging torque characteristics, especially the order of the cogging torque on the low‐speed rotor, have not been clarified.

In the near future, cogging torque reduction methods will be proposed, and verified by conducting 3‐D FEM analyses and carrying out measurements on a prototype. Furthermore, the torque characteristics when an electrical current is applied to the coils and the eddy‐current loss characteristics will be verified.

This article addresses the lack of scholarly attention paid to the sharing economy from a sociological perspective, with respect to the technology-mediated interactions between sharing economy users. The paper provides a critical overview of the sharing economy and its impact on business and communities and explores how information technology can facilitate authentic, genuine sharing through exercising and enabling conviviality and non-direct reciprocity.

The paper begins with a critique of the technology-mediated sharing economy, introduces the concept of conviviality as a tool to grow and shape community and sustainability within the sharing economy and then explores reciprocity and sharing behaviour. Finally, the paper draws upon social exchange theory to illustrate conviviality and reciprocity, using four case studies of technology-enabled sharing.

The paper contributes to the emerging debate around how the sharing economy, driven by information systems and technology, affects social cohesion and personal relationships. The paper elucidates the central role conviviality and reciprocity play in explaining the paradoxes, tensions and impact of the sharing economy on society. Conviviality and reciprocity are positioned as key capabilities of a more sustainable version of the sharing economy, enabled via information technology.

The findings reveal that information technology-mediated sharing enterprises should promote conviviality and reciprocity in order to deliver more positive environmental, economic and social benefits. The diversity of existing operations indicated by the findings and the controversies discussed will guide the critical study of the social potential of sharing economy to avoid treating all sharing alike.

This paper aims to propose a new magnetic-geared motor (MGM) which can easily increase the gear ratio up to approximately several hundred. The operational principle is described, and the relationship between the maximum transmission torques of each layer of the differential harmonic magnetic gear is investigated using a mathematical model and finite element method (FEM).

The operational principle and maximum transmission torque are described using a mathematical model. The FEM is used to investigate the operational principle and torque characteristics.

As the proposed model can realize a larger gear ratio than the conventional model, the torque constant can be approximately 100 times as large as that of the conventional model.

The proposed and conventional models have the same shape stator, and it is not optimized.

The relationship between the maximum transmission torques of each layer is described, and this helps the design of a differential type MGM.

This paper aims to present a cascaded pseudo derivative feedback (PDF) plus pseudo derivative feedback plus pseudo derivative feedforward (PDFF) controller for a permanent magnet synchronous motor (PMSM) to improve the transient response of the system.

Proportional integral (PI) plus PI controller and the proposed PDF plus PDFF controller are designed, stability analysis is performed using the extended root locus method, and the effect of the damping coefficient is also extensively studied to validate the robustness of the proposed controller.

When compared to a cascaded PI plus PI controller, the proposed control approach has a much shorter settling time for the entire system and a 50% reduction in overshoot in stator current under extensive variations in speed with load disturbance.

The proposed controller is programmed into an FPGA Altera Cyclone II and applied to a 1.5 kW laboratory prototype PMSM drive. The effectiveness of the proposed methods has been demonstrated experimentally throughout a wide variable speed range, from 0 to 157 rad/s at different load conditions.