Wei‐Zhong Fei, Jian‐Xin Shen, Can‐Fei Wang and Patrick Chi‐Kwong Luk
The purpose of this paper is to propose a new outer‐rotor permanent‐magnet flux‐switching machine (ORPMFSM) for electric vehicle (EV) in‐wheel propulsion. The paper documents both…
Abstract
Purpose
The purpose of this paper is to propose a new outer‐rotor permanent‐magnet flux‐switching machine (ORPMFSM) for electric vehicle (EV) in‐wheel propulsion. The paper documents both the design procedure and performance investigation of this novel machine.
Design/methodology/approach
The topology and preliminary sizing equations of the ORPMFSM are introduced. The rotor poles are optimized, whilst the machine losses are particularly investigated, using 2‐D finite element analysis (FEA).
Findings
An ORPMFSM, with 12 stator poles and 22 rotor poles, is most suitable for the proposed EV application. The analytical sizing equations are quite efficient with a sufficient accuracy for the preliminary design. The optimal rotor pole width from the FEA results is nearly 1.3 times the original value which was proposed in early literatures. The efficiency of the proposed machine under rated load is slightly low, as a result of significant eddy current losses in the permanent magnets. The losses can be effectively suppressed with the technique of magnet segmenting. The predicted outstanding performance implies that by adopting magnet segmentation the proposed machine is a leading contender for EV direct drives.
Originality/value
The outer‐rotor structure of PMFSM was not addressed in early literatures. This paper provides designers with the technical background and an alternative candidate for the EV propulsion.
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Fei Zhong, Chunlei Zhang, Wensheng Li, Jingpin Jiao and Liqiang Zhong
Super304H steel is a new fine-grained austenitic heat-resistant stainless steel developed in recent years, and it is widely used in high temperature section superheater and…
Abstract
Purpose
Super304H steel is a new fine-grained austenitic heat-resistant stainless steel developed in recent years, and it is widely used in high temperature section superheater and reheater tubes of ultra-supercritical thermal power units’ boiler. Currently intergranular corrosion (IGC) has occurred in a few austenitic stainless steel tubes in ultra-supercritical units and led to boiler leakage. The purpose of this paper is to find a nondestructive method to quickly and easily detect IGC of austenitic stainless steel tube.
Design/methodology/approach
This paper uses the nonlinear characteristics of ultrasonic propagation in steel tube to detect the IGC of Super304H tube.
Findings
The experimental results show that the nonlinear coefficient generally increases sensitively with the degree of IGC; hence, the nonlinear coefficient can be used to assess IGC degree of tubes, and the nonlinear coefficient measurement method is repeatable for the same tube.
Research limitations/implications
A theory of how IGC would affect the ultrasonic signals and lead to a nonlinear response needs further research.
Practical implications
A nondestructive method to quickly and easily detect IGC is provided.
Social implications
Using ultrasonic nonlinear coefficient to assess IGC degree of tubes is a new try.
Originality/value
This paper provides a new way to test IGC.
Jian‐Xin Shen, He Hao, Meng‐Jia Jin and Wei‐Zhong Fei
The purpose is to present a sensorless control method by which high‐resolution rotor position information is estimated and used for phase‐advancing operation of a high‐speed…
Abstract
Purpose
The purpose is to present a sensorless control method by which high‐resolution rotor position information is estimated and used for phase‐advancing operation of a high‐speed permanent magnet (PM) brushless DC (BLDC) motor.
Design/methodology/approach
The proposed sensorless control approach uses hardware to observe the flux vector which is excited by rotor magnets. It can provide the rotor position which is the same as the phase angle of the observed flux vector.
Findings
High‐resolution rotor position signal of the BLDC motor for dynamic phase‐advancing control cannot be directly obtained from the conventional Hall‐effect sensors, or via the traditional back‐EMF‐based sensorless control strategies in which the back‐EMF may be even undetectable at high‐speed. The proposed rotor‐flux‐observer (RFO)‐based sensorless control method overcomes these problems, and meanwhile provides high‐resolution rotor position information for the phase‐advancing purpose.
Originality/value
The RFO‐based sensorless control is traditionally applied to PM brushless ac (BLAC) operations, where the motor voltage vector can be calculated from the inverter switching status. However, this is not readily applicable to a BLDC motor since the voltage of the floating phase cannot be calculated. Moreover, during high‐speed operation, the microprocessor may not be sufficiently fast to calculate the high‐resolution rotor position. Therefore, in this paper, it is proposed to use hardware to observe the rotor‐flux‐vector. The microprocessor only samples the vector's α‐ and β‐components and calculates the phase angle, hence, its burden is low. The proposed method is validated with a 1.8 kW 85,000 rpm BLDC motor system.
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China's resource allocation mechanism in education has become an important factor in determining residential access to educational resources. The purpose of this paper is to…
Abstract
Purpose
China's resource allocation mechanism in education has become an important factor in determining residential access to educational resources. The purpose of this paper is to analyze the impacts made by the individual natures of buyers, the external environment, as well as the characteristics of residential properties on the willingness price of buyers. The study's aim is to lay theoretical foundations for the determination of problems related with the matters under consideration.
Design/methodology/approach
Using the panel data of 54 districts and counties in Beijing, Shanghai, Guangzhou and Shenzhen, the study unifies macro factors and micro factors in a model for empirical analysis.
Findings
Basic education resources can affect housing prices via the “capitalization of education.” The degree of those educational resources’ influence on willingness price changes according to personal income levels, standards of living, housing price fluctuations, the convenience of the residential area and the degrees of urbanization in a district. The greater the buyer's income and standard of living is, the higher is their willingness price. Buyers in urbanized areas prefer increases in educational resources. Increased educational resources increase the values of residential downtown areas. In developed areas with private educational facilities, the role of educational resources in influencing property prices is relatively small.
Originality/value
This paper uses data concerning the consumption and investment of residential properties to build a theoretical model for the willingness price of buyers. It unifies macro factors and micro factors in a single model and presents new results about basic education resources and the willingness price of buyers under different conditions.
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Rahul Sindhwani and Vasdev Malhotra
The advent of globalization not only made the manufacturing sector highly competitive but also facilitated best-quality products. The trend is further augmented by e-Commerce…
Abstract
Purpose
The advent of globalization not only made the manufacturing sector highly competitive but also facilitated best-quality products. The trend is further augmented by e-Commerce which increases the penetration to the targeted customer with the easy availability of customized product. In this backdrop, Indian manufacturing industries are striving hard to seek out best systems which will yield maximum profitability. Time is ripe to realize the true potential of agile manufacturing system (AMS). Infusion of AMS in manufacturing industry will bring forth the elusive mix of customer needs and products at lowest possible cost. But adoption and implementation of AMS is a challenging task in itself. There are certain facilitators and criteria which not only facilitate the system but also help in the effective and smooth implementation of this system. The purpose of this paper is to identify the criteria to weightage and ranking to AMS facilitators. This study was carried out by different approaches, namely, entropy approach, multi-objective optimization on the basis of ratio analysis (MOORA) method, Vlsekriterijumska Optimizacija I Kompromisno Resenje (VIKOR) analysis and a cross-sectional survey of manufacturing firms in India.
Design/methodology/approach
The criteria and facilitators are identified followed by the application of entropy approach, MOORA method and VIKOR analysis to study and analyze the criteria weight and provide the ranking to AMS facilitators.
Findings
The result of the entropy approach concludes that beneficiary and non-beneficiary criteria carry 48.43 and 51.56 percent weight, respectively. MOORA method and VIKOR analysis conclude that organization structure and virtual enterprise facilitators are carrying the first and second rank, respectively.
Research limitations/implications
This study is completed on the basis of responses from few experts from industry and academicians who may not reflect the attitude of entire industry community.
Practical implications
This research is expected to facilitate policy makers in government and industries to frame policies for optimum utilization of resources and infrastructure for better performance. This paper helps the researcher to do a case study on the implementation of AMS and then finally helps to society in getting the high-quality product in an easy way.
Originality/value
Integration of entropy approach, MOORA method and VIKOR analysis with identification of AMS criteria weightage and ranking to AMS facilitators has been recommended for an industry which is an innovative effort for the execution of AMS.
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Wanjuan Zhong and Lisa Catherine Ehrich
The purpose of this paper is to explore two dimensions of leadership practices (i.e. teaching and learning and sources of power) used by two exemplary principals in mainland China…
Abstract
Purpose
The purpose of this paper is to explore two dimensions of leadership practices (i.e. teaching and learning and sources of power) used by two exemplary principals in mainland China against a background of education reform and to identify how broader contextual factors have shaped these two dimensions of their leadership.
Design/methodology/approach
An exploratory case study was used that drew upon semi‐structured interviews, observations and document analysis. Interviews were conducted with two principals, six teachers from each of the two schools and a superintendent who was the supervisor of the two principals.
Findings
The findings reveal that there are some common elements in both of the leaders' practices but also some subtle differences. Both leaders emphasise teaching and learning. One sees herself as curriculum expert; the other delegate teaching responsibilities. While both uses a top down approach, one principal uses an adversarial approach and the other a more facilitative approach.
Research limitations/implications
The study used a small sample size. It explored the leaders' practices in the light of broader contextual factors rather than personal factors or gender‐based factors
Originality/value
Given the limited empirical research conducted on female principals in mainland China, this qualitative study provides insights into two dimensions of leadership used by two exemplary principals and explains their practices in the light of critical contextual factors such as contemporary and traditional Chinese culture and the school's organisational context.
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Haowei Zhang, Lili Sun, Chengli Song, Ying Liu, Xueting Xuan, Fei Wang, Jing Zhong and Li Sun
Design, fabricate and evaluate all-solid-state wearable sensor systems that can monitor ion concentrations in human sweat to provide real time health analysis and disease…
Abstract
Purpose
Design, fabricate and evaluate all-solid-state wearable sensor systems that can monitor ion concentrations in human sweat to provide real time health analysis and disease diagnosis capabilities.
Design/methodology/approach
A human health monitoring system includes disposable customized flexible electrode array and a compact signal transmission-processing electronic unit.
Findings
Patterned rGO (reduced-graphene oxide) layers can replace traditional metal electrodes for the fabrication of free-standing all solid film sensors to provide improved flexibility, sensitivity, selectivity, and stability in ion concentration monitoring. Electrochemical measurements show the open circuit potential of current selective electrodes exhibit near Nernst responses versus Na+ and K+ ion concentration in sweat. These signals show great stability during a typical measurement period of 3 weeks. Sensor performances evaluated through real time measurements on human subjects show strong correlations between subject activity and sweating levels, confirming high degree of robustness, sensitivity, reliability and practicality of current sensor systems.
Originality/value
In improving flexibility, stability and interfacial coherency of chemical sensor arrays, rGO films have been the developed as a high-performance alternative to conventional electrode with significant cost and processing complexity reduction. rGO supported solid state electrode arrays have been found to have linear potential response versus ion concentration, suitable for electrochemical sensing applications. Current sweat sensor system has a high degree of integration, including electrode arrays, signal processing circuits, and data visualization interfaces.
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Junjian Lu, Hongbin Zhong and Fei Luo
The purpose of this research is as follows: DPP-BOH-PVA has been synthesized from 1,1′:3′,1″-terphenyl-5'-boronic acid (DPP-OH) and polyvinyl alcohol (PVA). The afterglow lifetime…
Abstract
Purpose
The purpose of this research is as follows: DPP-BOH-PVA has been synthesized from 1,1′:3′,1″-terphenyl-5'-boronic acid (DPP-OH) and polyvinyl alcohol (PVA). The afterglow lifetime of DPP-BOH-PVA was studied by changing contents of DPP-OH (1, 2 and 4 Wt.%). These films were characterized with Fourier transform infrared, X-ray diffraction as structural analysis and DSC as thermal analysis. Afterglow lifetimes were evaluated as time-resolved emission decay profile analysis. Fiber films of DPP-BOH-PVA-2-E have been prepared by electrospinning method with the diameter of 5 μm and afterglow life time of 2.1 s (@ 535 nm) under ambient conditions. Stimulus responsive properties with afterglow emission for fiber film were investigated.
Design/methodology/approach
During the synthesis of the polymer, modification was carried out using DPP-OH/PVA with a molar ratio of 1/4, under an alkalinity medium with ammonium hydroxide and with a temperature of 80°C.
Findings
XRD results indicate that DPP-BOH-PVA film had high crystallinity, which is crucial for preparing organic room temperature phosphorescence (RTP) materials.
Research limitations/implications
The reaction mixture must be stirred continuously. Temperature should be controlled to prevent the rapid evaporation of ammonium hydroxide.
Practical implications
This study provides technical information for the synthesis of multidimensional stimulation response RTP micron fiber thin film. The electrospinning technology may also promote the applications of the large areas of RTP films.
Social implications
This resin will be used for the multidimensional stimulation response RTP fiber thin film.
Originality/value
The diameter of fiber film of PP-BOH-PVA-2-E by electrospinning method was in the range of 5 μm, and its afterglow lifetime decayed to be 2.1 s.
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Keywords
Han Zhang, Ying Bi, Fei Kang and Zhong Wang
The purpose of this paper is to analyze the factors influencing the behaviors of government officials during the implementation of open government data (OGD). By identifying and…
Abstract
Purpose
The purpose of this paper is to analyze the factors influencing the behaviors of government officials during the implementation of open government data (OGD). By identifying and understanding the key factors that determine government officials' adoption of OGD in China, this study can create a valuable reference for other countries and their decision-making regarding government implementation of OGD.
Design/methodology/approach
This research collected data by in-depth interviews with government officials in Chinese OGD departments. Through these interviews, the authors consulted 15 administrators from departments that are responsible for the information tasks in Beijing and other cities on their opinions about OGD. The authors also interviewed senior executives from information technology (IT) companies, as well as open data policy scholars from big data alliance and research institutions.
Findings
This paper provides insights about how to promote government officials in OGD implementation, including (1) strengthen social supervision for the environment, through developing and publishing OGD technology roadmaps, then attracting the public to actively participate in the implementing of OGD; (2) establish an OGD assessment mechanism for government officials, with bonus motivations, position promotion incentives, as well as spiritual incentives via regional or sector rankings; (3) alleviate the risks of officials' OGD decisions in actual practice, using the institution construction of OGD to guide its direction and strengthen security protection.
Originality/value
This paper fulfils an identified need to study how government officials' behavior can be motivated on OGD implementation.
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Wei Quan, Bikun Chen and Fei Shu
The purpose of this paper is to present the landscape of the cash-per-publication reward policy in China and reveal its trend since the late 1990s.
Abstract
Purpose
The purpose of this paper is to present the landscape of the cash-per-publication reward policy in China and reveal its trend since the late 1990s.
Design/methodology/approach
This study is based on the analysis of 168 university documents regarding the cash-per-publication reward policy at 100 Chinese universities.
Findings
Chinese universities offer cash rewards from USD30 to USD165,000 for papers published in journals indexed by Web of Science, and the average reward amount has been increasing for the past ten years.
Originality/value
The cash-per-publication reward policy in China has never been systematically studied and investigated before except for in some case studies. This is the first paper that reveals the landscape of the cash-per-publication reward policy in China.