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COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 42 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 6 November 2017

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…

301

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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COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 6 November 2017

Xian Zhang, Zhaoyang Yuan, Yang Qingxin, Zhaohui Wang, Hao Meng and Yao Jin

The purpose of the paper is to analyze the impact of coupling on the distribution of the magnetic field and study the characteristics of the magnetic flux density in the…

231

Abstract

Purpose

The purpose of the paper is to analyze the impact of coupling on the distribution of the magnetic field and study the characteristics of the magnetic flux density in the transmission process of the magnetic coupling resonant wireless power transmission (MCR-WPT) system, which provides guidance on the design of the WPT system.

Design/methodology/approach

In this study, a finite element simulation analysis was conducted and a three-dimensional (3D) electromagnetic field measurement platform was used.

Findings

It is shown that the distribution of the magnetic field, as well as the position of maximum magnetic flux density, will change when the coils are coupled. The simulation results of the magnetic field distribution, as well as the transmission performance, are different from those in practice. It cannot describe the actual performance of WPT system.

Originality/value

A 3D electromagnetic field measurement system and the host computer software are designed to help optimize the simulation and carry out more accurate and efficient research. The 3D electromagnetic field measurement system can be used to study the distribution of the spatial electromagnetic field, influencing factor, exposure and interoperability between different coils.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 26 May 2022

Liang Jin, Yuankai Liu, Qingxin Yang, Chuang Zhang and Suzhen Liu

Under the condition of small data set, a prediction model of motor magnetic field is established based on deep learning method. This paper aims to complete the magnetic field…

99

Abstract

Purpose

Under the condition of small data set, a prediction model of motor magnetic field is established based on deep learning method. This paper aims to complete the magnetic field prediction quickly and accurately.

Design/methodology/approach

An improved Linknet model is proposed to predict the motor magnetic field. This is a digital twin technology, which can predict the function values of other points according to the function values of typical sampling points. The results of magnetic field distribution are represented by color images. By predicting the pixels of the image, the corresponding magnetic field distribution is obtained. The model not only considers the correlation between pixels but also retains the spatial information in the original input image and can well learn the mapping relationship between motor structure and magnetic field.

Findings

The model can speed up the calculation while ensuring the accuracy and has obvious advantages in large-scale calculation and real-time simulation.

Originality/value

Under the condition of small data set, the model can well learn the mapping relationship between motor structure and magnetic field, so as to complete the magnetic field prediction quickly and accurately. In the future, according to the characteristics of magnetic field distribution, it will lay a foundation for solving the problems of rapid optimization, real-time simulation and physical field control of electrical equipment.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 42 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 1 January 2014

Zhang Xian, Yang Qingxin, Chen Haiyan, Zhang Xin, Jin Liang and Li Yang

The purpose of the paper is to show that how a contactless power transmission system via electromagnetic (EM) resonantly coupling power transmission (RCPT) technology may be…

182

Abstract

Purpose

The purpose of the paper is to show that how a contactless power transmission system via electromagnetic (EM) resonantly coupling power transmission (RCPT) technology may be analyzed in-depth by using a detailed T-type two-port network model with leakage inductance variable.

Design/methodology/approach

Through the introduction of coupling coefficient and quality factor, the influence of different physical parameters on the system performance is taken into consideration and validated by power transmission experiment.

Findings

It is shown that system performance is mainly subject to coupling coefficient and quality factor from the two-port network model in this paper. Moreover, there are three working status of dynamic transmission, which are over coupling, critical coupling and under coupling.

Originality/value

Two-port network model applied to practical RCPT system design considering impedance loss on resonators, etc.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 33 no. 1/2
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 14 May 2018

Mohammad Alamgir Hossain, Shams Rahman, Tamgid Ahmed Chowdhury, Caroline Chan, Xiaoyan Yang and Qingxin Su

A major transformation in retail logistics over the few years is backed by enormous improvements in internet technologies. It is now easy for e-retailers to entertain delivery…

951

Abstract

Purpose

A major transformation in retail logistics over the few years is backed by enormous improvements in internet technologies. It is now easy for e-retailers to entertain delivery progression, or consumers can share use-experience with future customers and thereby reducing information asymmetry. The purpose of this paper is to investigate the effect of different signals on consumer behavior in the presence of information asymmetry, in the context of online group buying (OGB) markets in China.

Design/methodology/approach

Based on the lemon market theory (LMT) and signaling theory, the study develops a research model of the OGB consumers’ context in China, which is validated using data from an online survey. A total of 528 responses are used for data analysis applying structural equation modeling technique.

Findings

The findings of the study show that perceived vendor quality (PVQ) and perceived product quality (PPQ) have significantly positive effects on intention to purchase from OGB websites. PVQ is associated with perceived reputation and perceived trustworthiness (PT) of vendor, and the determinants of PPQ are quality assurance information of products, and information about mer-chants. Further, PT has a mediating effect, while asymmetry of information has a moderating effect.

Research limitations/implications

The research model is valid as a generic OGB model that can be investigated in other contexts to understand the generalizability of the findings. Future research is needed to incorporate additional relevant factors (e.g. price, advertising activity/investments) that may help increase the acceptability of the model to a wide range of e-commerce contexts. Two of the control variables (gender and prior internet experience) were found to be significant; this could be further examined in future studies to determine the relative impact on each causal relationship.

Originality/value

Whereas prior studies in the domain of consumer service proposed different signaling mechanisms that were believed to eliminate information asymmetry from a market, the study sheds light on the effectiveness of the signals in the OGB context. This is a unique effort that applies and extends LMT and signaling theory in OGB context by theorizing the associated dimensions and their causal effects.

Details

International Journal of Physical Distribution & Logistics Management, vol. 48 no. 7
Type: Research Article
ISSN: 0960-0035

Keywords

Available. Open Access. Open Access
Article
Publication date: 26 September 2019

Yongjing Wang, Qingxin Lan, Feng Jiang and Chaofan Chen

As the contradiction between economic development, resource and environment has become increasingly prominent, low-carbon competitiveness has received worldwide focus. This study…

1656

Abstract

Purpose

As the contradiction between economic development, resource and environment has become increasingly prominent, low-carbon competitiveness has received worldwide focus. This study aims to examine low-carbon competitiveness in 31 provinces (cities and regions) of China.

Design/methodology/approach

An evaluation index system for low-carbon competitiveness in China has been constructed, which is composed of 25 economic, social, environmental and policy indicators. To study the state of low-carbon competitiveness and resistance to China’ development of low-carbon competitiveness, this study uses a combination of the catastrophe progression model, the spatial autocorrelation model and the barrier method.

Findings

China’ low-carbon competitiveness gradually decreases from coastal to inland areas: the Tibet and Ningxia Hui autonomous regions are the least competitive regions, while the Shandong and Jiangsu provinces are the most competitive areas. The spatial correlation of the 31 provinces’ low-carbon competitiveness is very low and lacks regional cooperation. This study finds that the proportion of a region’ wetland area, the proportion of tertiary industries represented in its GDP and afforestation areas are the main factors in the development of low-carbon competitiveness. China should become the leader of carbon competitiveness by playing the leading role in the Eastern Region, optimizing the industrial structure, improving government supervision and strengthening environmental protection.

Originality/value

The paper provides a quantitative reference for evaluating China’ low-carbon competitiveness, which is beneficial for environmental policymaking. In addition, the evaluation and analysis methods offer relevant implications for developing countries.

Details

International Journal of Climate Change Strategies and Management, vol. 12 no. 1
Type: Research Article
ISSN: 1756-8692

Keywords

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Article
Publication date: 12 June 2023

Shan Jiang, Duc Khuong Nguyen, Peng-Fei Dai and Qingxin Meng

In the hybrid knowledge-sharing platform where paid and nonpaid (“free”) knowledge activities coexist, users’ free knowledge contribution may be influenced by financial factors…

428

Abstract

Purpose

In the hybrid knowledge-sharing platform where paid and nonpaid (“free”) knowledge activities coexist, users’ free knowledge contribution may be influenced by financial factors. From the perspective of opportunity cost, this study investigates the direct effect of how the amount of monetary income from users’ contribution to paid knowledge activities influences their free knowledge contribution behavior in the future. Further, this study aims to verify the interaction effect of financial and nonfinancial factors (i.e. the experience of free knowledge contribution and social recognition) on free knowledge contribution.

Design/methodology/approach

Objective data was collected from a hybrid knowledge-sharing platform in China and then analyzed by using zero-inflated negative binomial regression model.

Findings

Results show that the amount of monetary income that knowledge suppliers gain from paid knowledge contribution negatively influences their free knowledge contribution. Experience of free knowledge contribution strengthens the negatively main effect, while social recognition has the weakening moderating role.

Originality/value

Although some studies have explored and verified the positive spillover effect of financial incentives on free knowledge contribution, the quantity dimension is ignored. This study examines the hindering influence of the quantity of monetary income from the perspective of opportunity cost. By taking the characteristic of knowledge suppliers and platforms as moderators, this study deepens the understanding of the influence of monetary income on free knowledge contribution in the hybrid knowledge-sharing platform.

Details

Journal of Knowledge Management, vol. 28 no. 2
Type: Research Article
ISSN: 1367-3270

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Article
Publication date: 6 January 2021

Jiawen Chen, Linlin Liu and Qingxin Chen

Empirical data on the impacts of entrepreneurial effectuation on firm performance are scattered and controversial. This study conducts a meta-analysis to obtain evidence on…

1303

Abstract

Purpose

Empirical data on the impacts of entrepreneurial effectuation on firm performance are scattered and controversial. This study conducts a meta-analysis to obtain evidence on whether and under what conditions effectuation is valuable. A contextual framework is proposed that highlights the boundary condition of the performance impact of effectuation.

Design/methodology/approach

Both the traditional approach of meta-analysis and advanced techniques of Bayesian meta-analytic tests are used to combine numerous studies from varied research contexts.

Findings

Meta-analytic results show that effectuation generally has a positive impact on firm performance, and is context-dependent, leading to stronger performance for older firms and firms in high-tech industries and emerging countries.

Originality/value

The findings provide important implications for entrepreneurs who are considering applying effectuation. This study highlights that effectuation is context-dependent and the performance implications of effectuation are contingent on contextual factors at organizational, industrial and institutional levels. This study extends the contextual understanding of the effectuation–performance relationship.

Details

International Journal of Entrepreneurial Behavior & Research, vol. 27 no. 3
Type: Research Article
ISSN: 1355-2554

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Article
Publication date: 28 June 2024

Xinquan Cheng, Yuanhong Chen, Pingfan Wang, YanXi Zhou, Xiaojing Wei, Wenjiang Luo and Qingxin Duan

This study aims to introduce an innovative framework for mining tourism reviews that not only excels in sentiment analysis accuracy but also prioritizes user-friendly design for…

298

Abstract

Purpose

This study aims to introduce an innovative framework for mining tourism reviews that not only excels in sentiment analysis accuracy but also prioritizes user-friendly design for enhanced usability.

Design/methodology/approach

Online reviews of China’s Five Sacred Mountains were analyzed using an integrated methodology. Sentiment analysis was performed using ChatGPT, bidirectional encoder representations from transformers (BERT) and convolutional neural networks, with ChatGPT demonstrating superior performance. Latent Dirichlet allocation extracted key attributes. Models including importance–performance analysis (IPA), asymmetric impact-performance analysis (AIPA) and importance–performance competitor analysis (IPCA) then synthesized findings.

Findings

The results demonstrate that ChatGPT outperforms both machine learning and lexicon-based models in sentiment recognition, exhibiting performance comparable to that of the BERT model. In the case study, integrating sentiment analysis outcomes with IPA reveals deficiencies in both topics and attributes. Moreover, the synergistic combination of IPA, AIPA and IPCA furnishes actionable recommendations for resource management and enables nuanced monitoring of sustainability attributes.

Practical implications

Leveraging this framework in conjunction with the ChatGPT platform for application development can bring practical convenience to the tourism industry. It supports sentiment analysis, topic categorization and opinion mining. Equipped with monitoring capabilities, it provides valuable insights for sustainable improvement, aiding managers in formulating effective marketing strategies.

Originality/value

This research develops a novel multimodel framework integrating various ML/DL techniques and business models in a synergistic way. It provides an innovative and highly accurate yet simple approach to tourism review mining and enhances accessibility of advanced artificial intelligence for sustainable tourism monitoring, addressing limitations of prior methods.

研究目的

本研究旨在引入一种创新的框架, 用于挖掘旅游评论, 不仅在情感分析准确性方面表现出色, 而且还优先考虑用户友好设计, 以提升可用性。

研究方法

本研究使用综合方法分析了中国五岳的在线评论, 使用ChatGPT进行情感分析。LDA提取了关键属性。然后, 包括IPA、AIPA和IPCA在内的模型综合了研究结果。

研究发现

结果表明, ChatGPT在情感识别方面优于机器学习和基于词典的模型, 表现与BERT模型相当。在案例研究中, 将情感分析结果与IPA结合起来揭示了主题和属性的不足。此外, IPA、AIPA和IPCA的协同组合为资源管理提供了可行的建议, 并实现了对可持续属性的细致监控

实践意义

结合ChatGPT平台在应用开发中利用该框架可以为旅游业带来实际便利。它支持情感分析、主题分类和意见挖掘。配备了监控功能, 为可持续改进提供了宝贵的见解, 帮助管理者制定有效的营销策略。

研究创新

本研究开发了一种新颖的多模型框架, 将各种ML/DL技术和商业模型以协同方式整合在一起。它提供了一种创新而高度准确但简单的方法, 用于旅游评论挖掘, 并提升了高级AI的可访问性, 以实现可持续旅游监测。

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