Jingsong Li, Lixiang Wang, Qingxin Yang, Shanming Wang, Yongjian Li, Changgeng Zhang and Baojun Qu
Due to existence of skin effect under rotational excitation, especially to high-frequency motors and power transformers run at the frequency of hundreds or even thousands of…
Abstract
Purpose
Due to existence of skin effect under rotational excitation, especially to high-frequency motors and power transformers run at the frequency of hundreds or even thousands of hertz, core losses will increase significantly, which may cause local overheating damage, and the efficiency and longevity will be decreased. The purpose of this paper is to accurately calculate the rotational anomalous loss in electrical steel sheets.
Design/methodology/approach
The influence of skin effect to rotational anomalous loss coefficient is described in detail. Based on the rotational core losses calculation approach, the transformed coefficient and parameters of rotational anomalous loss are determined in accordance with experimental data obtained by using 3D magnetic properties testing system. Then, a variable loss coefficient calculation model of rotational anomalous loss is built. Meanwhile, a separation of the total 2D elliptical rotation experimental core losses is worked out.
Findings
The two methods are analysed and compared qualitatively. It should be noted that the novel calculation model can be more effectively presented anomalous loss features. Moreover, quantitative comparisons between 2D elliptical rotation and alternating core losses have achieved beneficial conclusions.
Originality/value
Transformed rotational anomalous loss coefficient and parameters of electrical steel sheets considering skin effect are determined. Based on that, a novel calculation model evaluating 2D elliptical rotation anomalous loss is presented and verified based on the experimental measurement and the separation of the total 2D elliptical rotation core losses. The 2D elliptical rotation core losses separation method and quantitative comparison with alternating excitation are helpful to engineering application.
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Menglong Li, Jingsong Nie and Yujia Ren
College badminton gymnasium is an important place where students take physical exercise. Student satisfaction index for badminton gymnasium is an important factor which influences…
Abstract
College badminton gymnasium is an important place where students take physical exercise. Student satisfaction index for badminton gymnasium is an important factor which influences the design of badminton gymnasium. To improve the design and construction level of college badminton gymnasium, student satisfaction index evaluation system for the design of college badminton gymnasium was constructed, and empirical study of the system was carried out. Delphi method was applied to screen evaluation indicators, and analytical hierarchy process (AHP) was used to confirm the weight of evaluation indicators. Finally, student satisfaction index evaluation system for the design of college badminton gymnasium was constructed, including 3 first-level indicators (external form design, internal layout design and application function design) and 12 second-level indicators. Hunan University of Finance and Economics was taken for example to demonstrate student satisfaction index evaluation system for the design of college badminton gymnasium. Besides, comprehensive evaluation score of the badminton gymnasium was gained. The student satisfaction index evaluation system is an effective tool to evaluate the design of college badminton gymnasium. During the design of college badminton gymnasium in China, the application function and internal layout should mainly be taken into account.
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Nianyun Liu, Jingsong Li, Quan Liu, Hang Su and Wei Wu
Higher order statistics (HOS)-based blind source separation (BSS) technique has been applied to separate data to obtain a better performance than second order statistics-based…
Abstract
Purpose
Higher order statistics (HOS)-based blind source separation (BSS) technique has been applied to separate data to obtain a better performance than second order statistics-based method. The cost function constructed from the HOS-based separation criterion is a complicated nonlinear function that is difficult to optimize. The purpose of this paper is to effectively solve this nonlinear optimization problem to obtain an estimation of the source signals with a higher accuracy than classic BSS methods.
Design/methodology/approach
In this paper, a new technique based on HOS in kernel space is proposed. The proposed approach first maps the mixture data into a high-dimensional kernel space through a nonlinear mapping and then constructs a cost function based on a higher order separation criterion in the kernel space. The cost function is constructed by using the kernel function which is defined as inner products between the images of all pairs of data in the kernel space. The estimations of the source signals is obtained through the minimizing the cost function.
Findings
The results of a number of experiments on generic synthetic and real data show that HOS separation criterion in kernel space exhibits good performance for different kinds of distributions. The proposed method provided higher signal-to-interference ratio and less sensitive to the source distribution compared to FastICA and JADE algorithms.
Originality/value
The proposed method combines the advantage of kernel method and the HOS properties to achieve a better performance than using a single one. It does not require to compute the coordinates of the data in the kernel space explicitly, but computes the kernel function which is simple to optimize. The use of nonlinear function space allows the algorithm more accurate and more robust to different kinds of distributions.
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Yiting Kang, Biao Xue, Jianshu Wei, Riya Zeng, Mengbo Yan and Fei Li
The accurate prediction of driving torque demand is essential for the development of motion controllers for mobile robots on complex terrains. This paper aims to propose a hybrid…
Abstract
Purpose
The accurate prediction of driving torque demand is essential for the development of motion controllers for mobile robots on complex terrains. This paper aims to propose a hybrid model of torque prediction, adaptive EC-GPR, for mobile robots to address the problem of estimating the required driving torque with unknown terrain disturbances.
Design/methodology/approach
An error compensation (EC) framework is used, and the preliminary prediction driving torque value is achieved using Gaussian process regression (GPR). The error is predicted using a continuous hidden Markov model to generate compensation for the prediction residual caused by terrain disturbances and uncertainties. As the final step, a gain coefficient is used to adaptively tune the significance of the compensation term through parameter resetting. The proposed model is verified on a sample set, including the driving torque of a mobile robot on three different sandy terrains with two driving modes.
Findings
The results show that the adaptive EC-GPR yields the highest prediction accuracy when compared with existing methods.
Originality/value
It is demonstrated that the proposed model can predict the driving torque accurately for mobile robots in an unconstructed environment without terrain identification.
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Hui Wang, Jingsong Peng, Bing Zhao, Xin-Dong Zhang, Jie Yu, Yuan Li and Mao-Min Wang
Near-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the…
Abstract
Purpose
Near-net-shaped processes of jet engine blade have better performance in both reducing the material waste during production and improving work reliability in service, while the geometric features of blade, both sculptured surface and thin-walled shape, make the precise machining of blade challenging and difficult owing to its dynamics behaviors under complex clamping and machining loads. This paper aims to present a fundamental approach on modeling and performance analysis of the blade–fixture system.
Design/methodology/approach
A computerized framework on the complex blade–fixture dynamic behavior has been developed. Theoretical mechanic analysis on blade fixturing and machining is proposed with an especial emphasis on the boundary conditions of the blade–fixture system. Then the finite element analysis (FEA) method is used to simulate the variation trend of preloads, stiffness and blade distortion. The strong influence of parameters of workpiece–fixture configuration on blade distortion and machining error is investigated.
Findings
With a case of real jet engine blade machining, the experimental results and theoretical predictions suggest good agreement on their variation tendency. The loaded pressure of clamps has a critical influence on the total stiff performance of the blade–fixture system, and the profile error of the blade contributes much to the inconsistency in geometric dimension and surface integrity of blades’ machining. In the end, the results also validate the effectiveness of this methodology to predict and improve the performance of the blade–fixture configuration design.
Originality/value
The adaptive machining of near-net-shaped jet engine blade is a new high-performance manufacturing technology in aerospace production. This study provides a fundamental methodology for the performance analysis of blade-fixture system, to clear the variation law of blade distortion during preloading and machining, which will contribute to minimize the machining error and improve productivity.
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Online business can be an attractive career choice but bears gendered implications under China’s market economy. This study aims to examine how highly educated young women…
Abstract
Purpose
Online business can be an attractive career choice but bears gendered implications under China’s market economy. This study aims to examine how highly educated young women negotiate their career choice of online business, given their enhanced career ambitions and the persisting conservative views of their parents. It is to be examined how these factors interact in shaping women’s strategies and commitment to their nonconventional careers.
Design/methodology/approach
The study draws on 23 interviews with 18 women involved in online business. The interviews were coded by themes about how women perceive and make career choices to enter online business, the influence of various motivations (e.g., economic security, decency, autonomy and earning potential) and women’s interactions with their parents under gendered social expectations. The study analyzes and categorizes women’s varied strategies and levels of commitment in taking up online business, an attractive but suspicious career for highly educated young women.
Findings
The study finds that some women chose to conduct online business as a secondary job behind their stable and formal primary job; their compromise under parents’ preferences and social expectations as “compliant daughters,” willingly or forced, coexisted with their persisting interest in online entrepreneurship. Other women, or “self-determined daughters,” embraced online business as their primary job; some benefited from parents’ tolerant views, but others needed to handle the pressure of parental disapproval by hiding or proving their nonconventional career choices worthwhile.
Originality/value
This study speaks to the gendered opportunity-necessity framework of entrepreneurship by illustrating women’s multiple motivations in China’s market reforms and the rising online entrepreneurship dynamics. The findings contextualize women’s career choices in different family dynamics and suggest how social expectations and gender norms are imposed and transformed, with a focus on the shifting gendered concerns of opportunity, security and decency in an era of digital economy.
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This study aims to examine why women transition from wage work to self-employed entrepreneurship, the seemingly insecure and unruly economic sector compared with the stable iron…
Abstract
Purpose
This study aims to examine why women transition from wage work to self-employed entrepreneurship, the seemingly insecure and unruly economic sector compared with the stable iron rice bowl and the fancy spring rice jobs.
Design/methodology/approach
Based on in-depth interviews in Zhejiang, the entrepreneurial hotbed in coastal China, this study examines the experiences of self-employed female entrepreneurs who used to work in the iron rice bowl and the spring rice jobs and explores their nonconventional career transition and its gendered implications.
Findings
This study finds that these women quit their previous jobs to escape from gendered suppression in wage work where their femininity was stereotyped, devalued or disciplined. By working for themselves, these women embrace a rubber rice bowl that allows them to improvise different forms of femininity that are better rewarded and recognized.
Originality/value
The study contributes to studies on gender and work by framing femininity as a fluid rather than a fixed set of qualities and fills the research gap by illustrating women’s agency in reacting to gender expectations in certain workplaces. The study develops a new concept of rubber rice bowl to describe how entrepreneurship, a seemingly women-unfriendly sphere, attracts women by allowing them to comply with, resist, or improvise normative gender expectations.
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Siyuan Zhou and Jing Song
This study aims to examine whether skilled female migrants can overcome gender constraints and social stigma attached to women’s service work in host societies.
Abstract
Purpose
This study aims to examine whether skilled female migrants can overcome gender constraints and social stigma attached to women’s service work in host societies.
Design/methodology/approach
Based on interviews with 40 women who moved from mainland China and entered Hong Kong’s cross-border insurance business, the study examines how highly educated young women negotiate gender expectations and mobilize social networks in doing business.
Findings
This study finds different strategies women used in mobilizing social networks and constructing gender identities: some relied heavily on the warm market – networks of their family, relatives and friends – in doing business and developed careers by performing dutiful daughters, considerate “nieces” and caring “sisters”; some women also relied on the warm market but their jobs were regarded as nonconventional, and they had to deal with suspicions of inappropriate and instrumental womanhood and tried to prove themselves and gain support in the warm market; some women relied mainly on the cold market – connections with strangers – and performed feminine affinity to expand client networks away from judgments of families and friends; and some other women chose to expand the cold market by cultivating a professional image among strangers.
Originality/value
The findings speak to previous research about women’s subordinate roles in migrant networks and their devalued femininity in service work by illustrating women’s diverse forms of agency in negotiating gender identities in the stratified service sectors.
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Neale G. O'Connor, F. Johnny Deng and Jingsong Tan
The purpose of this paper is to investigate the influence of liberalization forces, political constraints (on labor decisions) and formal control mechanisms (i.e. delegation of…
Abstract
Purpose
The purpose of this paper is to investigate the influence of liberalization forces, political constraints (on labor decisions) and formal control mechanisms (i.e. delegation of decision authority, objective performance measurement and merit‐based rewards) on the performance of Chinese State‐owned enterprises (SOEs).
Design/methodology/approach
A survey instrument was used to collect data from functional managers representing over 500 SOEs. Structural equation modeling was used to analyze the data.
Findings
The findings revealed significant and positive path relationships between liberalization forces and each of the formal control mechanisms, leading to firm performance. The findings also reveal that political constraints have a significant and negative path relationship with objective performance measures and firm performance.
Originality/value
The evidence provided in this study adds to our understanding of the role the institutional environment plays in the structuring and management of the firm in transitional economies. The topic is of interest, given the pace of modernization of firms in emerging economies, and the differences in the institutional “rules of the game” that exist compared with developed economies. Both of these forces have the potential to affect not only the management control practices in emerging economy firms, but also other firms that do business with them.