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This paper aims to propose a spoke-type fractional-slot concentrated windings (FSCW) PM machine for EVs driving system to improve torque density. To further improve electromagnetic performance, the multi-objective optimization design is processed based on response surface (RS) model and simulated annealing cuckoo search (SA-CS) algorithm.

The spoke-type FSCW PM machine is designed and optimized to meet the requirement of EVs driving system. First, a spoke-type FSCW PM machine is designed and some of key parameters are obtained based on equivalent magnetic circuit (EMC) method. Then, the RS model and modified SA-CS algorithm are proposed to obtain higher torque, lower torque ripple and higher efficiency.

After verification by finite element method for no-load and load performance, the optimal machine has higher torque density, lower torque ripple and higher efficiency compared with initial machine. Finally, a 20 kW prototype is manufactured and tested to verify the validity of the proposed optimization design method.

This paper designs a high torque density spoke-type FSCW PM machine, which is superior for EVs driving system. Meanwhile, a novel modified SA-CS algorithm is applied to the field of electrical machine multi-objective optimal design.

This paper proposes a spoke-type fractional-slot concentrated windings (FSCW) permanent magnet (PM) machine for special vehicle driving systems to obtain higher torque and power density, high efficiency and wide field-weakening range. To enhance the efficiencies of multi-objective optimization processes, the respond surface (RS) method and black-hole (BH) algorithm are used.

The spoke-type FSCW PM machine is optimized to meet the requirements of the special vehicle driving system. The combination of the RS and BH algorithm is used to obtain high torque, low torque ripple and high efficiency.

The optimal spoke-type PM machine is obtained, and it has higher torque density, lower torque ripple, cogging torque and wider magnetic field weakening range. Finally, a 15-kW prototype machine is fabricated and tested to verify the results of the optimization method and finite-element analysis.

This paper designs a high torque density and efficiency spoke-type FSCW PM machine, which is superior for special vehicle driving systems. Meanwhile, the RS model combined with BH algorithm is applied to the field of electrical machine multi-objective optimal design.

The purpose of this study is the introduction of finite permeability of ferromagnetic core in analytical approach for slotted spoke-type permanent magnet machine.

A two-dimensional analytical approach of magnetic field distribution is established for spoke-type permanent magnet machine to calculate the flux density distribution in the middle of airgap. The paper presents an analytical subdomain model accounting for stator slotting effect. The governing equations are obtained from Maxwell’s equations by using vector potential in all regions of the machine, i.e. magnet, airgap, stator slots and rotor/stator yoke. The finite element analysis is used to validate the analytical results.

It is found that the developed subdomain model including finite permeability of ferromagnetic core is accurate and is applicable for spoke-type permanent magnet machine for no-load and on-load condition. The analytical results are in accurate agreement with the numerical simulation.

Some assumptions and conditions are presented to improve and simplify the analytical method for analyzing the global saturation for spoke-type permanent magnet machine.

This study aims to propose criteria for both optimal-shape and magnetizer-system designs to be used for a high-output spoke-type motor. The study also examines methods of reducing high-cogging torque and torque ripple, to prevent noise and vibration.

The optimal design of the stator and rotor can be enhanced using both a response surface method (RSM) and finite element method (FEM). In addition, a magnetizer system is optimally designed for the magnetization of permanent magnets for use in the motor.

The criteria not only improve performance but also reduce manufacturing costs. The criteria are verified FEM together with an RSM. These methods are used to optimize the stator and rotor shape and the magnetization system. These methods allow us to produce an efficient system for mass production of the motor.

This study proposed a design method that uses rare earth magnets in a system to replace the spoke-type IPM. To verify the optimal design, torque characteristics were analysed using FEM and RSM. Excellent results were achieved regarding the reduction of cogging torque and torque ripple. In addition, the design of the magnetizer enables a cost-effective mass production system for the motor.

In semi-analytical modeling of spoke-type permanent-magnet (PM) machines (STPMM), the saturation effect is usually neglected (i.e. iron parts are considered to be infinitely permeable) and the PM magnetization is assumed tangential (i.e. magnetization pattern is considered to be tangential-parallel). This paper aims to present an improved two-dimensional (2D) subdomain technique for STPMM with the PM magnetization orientation in quasi-Cartesian coordinates by using hyperbolic functions considering non-homogeneous Neumann boundary conditions (BCs) in non-periodic regions and by applying the interfaces conditions (ICs) in both directions (i.e. t- and θ edges ICs).

The polar coordinate system is transformed into a quasi-Cartesian coordinate system. The rotor and stator regions are divided into primary subdomains, and a partial differential equation (PDE) is assigned to each subdomain. In the PM region, the magnetization orientation is considered in the equations. By applying BCs, the general solution of the equations is determined, and by applying the ICs, the corresponding coefficients are determined.

Using the proposed coordinate system, the general solution of PDEs and their coefficients can mathematically be simplified. The magnetic field and non-intrinsic unbalanced magnetic forces (UMF) calculations have been performed for three different values of iron core relative permeability (200, 800 and ∞), as well as different magnetization orientation values (135 and 80 degrees). The semi-analytical model based on the subdomain technique is compared with those obtained by the 2D finite-element analysis (FEA). Results disclose that the PM magnetization angle can affect directly the performance characteristics of the STPMM.

A new model for prediction of electromagnetic performances in the STPMM takes into account magnetization direction, and soft magnetic material relative permeability in a pseudo-Cartesian coordinate system by using subdomain technique is presented.

Entrepreneurial ecosystems offer an approach to analyse the evolution and resilience of a region by placing the emphasis on the interactions that occur between entrepreneurs and the supporting regional resources. The purpose of this paper is to analyse the transformation of a region with high-growth firms to identify the coordinating structures that evolve in response to entrepreneurial recycling of resources.

This study uses network analysis to explore the scaling capability network of leaders in Dublin’s high-growth IT firms over a 15-year period.

After a gestation period of 10 years, leaders displayed prior experience from an initial entrant. Towards the end of the study period, numerous well-connected internet firms arose providing a structure resilient to exogenous and endogenous shocks.

The findings suggest that the region’s structure changed from a satellite platform to a “hub and spoke” type district, and is showing signs of becoming a Marshallian type district, although the analysis is limited to regional knowledge capital through leadership mobility and does not consider the financial, social or institutional capital described in the entrepreneurial ecosystems literature.

Policy that aims to create regional resilience but minimise the scope of intervention needed can encourage the introduction of an anchor firm to a region and can complement this initiative with regional capability accumulation through labour policies that encourage resource recycling and minimise human capital leakage.

This contributes to an understanding of how entrepreneurial ecosystems evolve and the structure of the supporting resources that lead to increased regional resilience.

The most significant point to be introduced in the subdomain technique (i.e. based on the formal resolution of Maxwell’s equations applied in subdomain) is the local saturation effect. This paper aims to present a novel contribution on the improvement in the two-dimensional (2-D) technique in polar coordinates by focusing on the local saturation.

The rotor and stator regions are divided into elementary subdomains (E-SDs) which are characterized by general solutions to the first harmonic of magnetostatic Maxwell equations. These E-SDs are connected in the two directions (i.e. r- and θ-edges). Newton–Raphson (NR) iterative algorithm is used for nonlinear magnetic field analysis.

The proposed model is relevant for different types of rotating electrical machines; as an example, the semi-analytical model has been implemented for spoke-type permanent-magnet (PM) machines (STPMMs). The magnetic field calculations have been performed for nonlinear B(H) curve and compared to nonlinear finite element method (FEM) predictions. The semi-analytic results are in good agreement with those obtained numerically, considering both amplitude and waveform.

A new model for full prediction of magnetic field in the rotating electrical machines with the local saturation effect is presented.

Fatigue damage of internal threads has gradually become the main failure mode of force sensor. To make the internal thread structure of force sensor meet the fatigue performance requirements, the design criteria of static strength and fatigue life are comprehensively considered in this paper.

The variation of static stress and fatigue life with the size of the main structure is obtained by simulation. By changing the number of thread turns, the hub height and outer diameter of the hub, the optimized design of the spoke force sensor is determined.

The experiment was carried out based on the determined optimized structure, and the results showed that the fatigue life meets the design requirements.

This research has certain guiding significance for the design and developments of high-cycle fatigue force sensors.

Rules of origin (ROOs) are often cited as major trade barriers even after tariff barriers are removed with the formation of preferential trade agreement (PTA) as shown in a survey result that a large number South Korean firms in the textile industry give up utilizing tariff-free exports to the USA after the bilateral Free Trade Agreement (FTA) due to ROOs. The purpose of this paper is to examine the impact of ROOs on the equilibrium FTA regime and the welfare effects.

The authors determine the impact of ROOs on the equilibrium FTA regime based on an oligopolistic model where there are asymmetry in production technologies of intermediate goods and the capacity of outsourcing intermediate goods.

The authors demonstrate that ROOs are used as a protective trade policy against the FTA member country with an outsourcing option for technologically dominant intermediate goods.

The non-cooperative features of ROOs found in this paper necessitates the introduction of an international coordination mechanism to avoid the prisoners’ dilemma-type implementation of ROOs.

This paper provides a theoretical frame to analyze the protective effects of ROOs under PTAs.

The purpose of this paper is to study how cost efficiency and the reliability of a physical distribution network are affected by changes in online shopping demand and to suggest how logistics service providers can respond to such changes.

Based on a discrete event simulation approach, possible adaptive measures to online shopping demand increase are tested at three levels of decision making in parcel distribution network: priority assignment in the main hub (operational), introduction of sub‐hubs (tactical), and increase in the hub‐terminal capacity (strategic). The feasibility of the simulation is tested with parameters adopted from the logistics service data of an existing major parcel carrier in South Korea.

Findings from the simulation model suggest that the existing physical distribution network can improve its cost efficiency and service reliability by evolving into a more centralized network structure with increased capacity of transshipment facilities if the online shopping demand is expected to increase consistently over the long run.

This research will help logistics service providers to have good insights into performances of their distribution networks at different levels of demand and to devise a plan for adaptation to meet future demand.

This paper provides a framework to understand the complex relationship between network configurations, service levels, costs, and other decision‐making processes with respect to changes in online shopping demand based on a simulation approach.