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1 – 10 of 29Hongbo Qiu, Wenfei Yu, Bingxia Tang, Weili Li, Cunxiang Yang and Yanfeng Wang
Taking a 2,000 r/min 10 kW permanent magnet motor as an example, the purpose of this paper is to study the influence of driving modes on the performance of permanent…
Abstract
Purpose
Taking a 2,000 r/min 10 kW permanent magnet motor as an example, the purpose of this paper is to study the influence of driving modes on the performance of permanent magnet motor at limit conditions, and researched the variation mechanism of motor performance influenced by different driving modes.
Design/methodology/approach
A two-dimensional electromagnetic field model of the permanent magnet motor was established, and a rectangular-wave driving circuit was built. By using the finite element method, the electromagnetic field, current, harmonic content and eddy current loss were calculated when the motor operated at rated load and limit load. On the basis of the motor loss calculation, the temperature field of the motor operating at rated condition and limit condition was researched, and the factors that influence motor limit overload capacity were analyzed. By analyzing the motor loss variation at different load conditions, the change mechanism of the motor temperature field was determined further. Combined with the related experiments, the correctness of the above analysis was verified.
Findings
Permanent magnet synchronous motor (PMSM) driven by sine wave is better compared with brushless direct current motor (BLDCM) driven by rectangular wave in reducing the magnetic field harmonics, motor losses and optimizing the temperature distribution in the motor. The method driven by sine wave could improve the motor output performance including the motor efficiency and the motor overload capacity. The winding temperature is the most important factor that limits the output capability of PMSM operating for a long time. However, because of the large rotor eddy current losses, the permanent magnet temperature is the most important factor that limits the output capability of BLDCM operating for a long time.
Practical implications
The influence of driving modes on the motor magnetic field, losses and temperature distribution, efficiency and overload capacity was determined, and the influence mechanism was also analyzed. Combined with the analysis of the electromagnetic and temperature fields, the advantages of different driving modes were presented. This study could provide an important basis for the design of permanent magnet motors with different driving modes, and it also provides reference for the application of permanent magnet motor.
Originality/value
This paper presents the influence of driving modes on permanent magnet motors. The limit output capacity of the motor with different driving modes was studied, and the key factors limiting the motor output capability were obtained.
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Abdulmannan Fadel, Andrew Plunkett, Weili Li, Yazan Ranneh, Vivian Elewosi Tessu Gyamfi, Yasser Salmon, Rosemarie Roma Nyaranga and Jason Ashworth
The purpose of this study is to discuss recent research on arabinoxylans from rice bran and wheat byproducts and their immunomodulatory potentials. Also, a potential…
Abstract
Purpose
The purpose of this study is to discuss recent research on arabinoxylans from rice bran and wheat byproducts and their immunomodulatory potentials. Also, a potential receptor for arabinoxylans is proposed in relation to arabinoxylans structure.
Design/methodology/approach
This review summarises recent publications on arabinoxylans from rice bran and wheat, classification of arabinoxylans, a brief background on their method of extraction and their immunomodulatory potentials as they induce pro-inflammatory response in vitro, in vivo and in humans. The mechanism of action in which arabinoxylans modulate the immune activity is yet to be discovered, However, the authors have proposed a potential receptor for arabinoxylans in relation to arabinoxylans structure and molecular weight.
Findings
The effects of arabinoxylans from rice bran and wheat on the immune response was found to cause a pro-inflammatory response in vitro, in vivo and in humans. Also, the immune response depends on arabinoxylans structure, the degree of branching and origin.
Originality/value
This review paper focuses on the effects of arabinoxylans from rice bran and wheat on immunomodulatory potentials in vitro, in vivo and in humans. A new mechanism of action has been proposed based on the literature and via linking between arabinoxylans and lipopolysaccharide structure, molecular weight and suggested proposed receptor, which might be activated via both of them.
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Yuchuan Wu, Shengfeng Qi, Feng Hu, Shuangbao Ma, Wen Mao and Wei Li
In human action recognition based on wearable sensors, most previous studies have focused on a single type of sensor and single classifier. This study aims to use a…
Abstract
Purpose
In human action recognition based on wearable sensors, most previous studies have focused on a single type of sensor and single classifier. This study aims to use a wearable sensor based on flexible sensors and a tri-axial accelerometer to collect action data of elderly people. It uses a statistical modeling approach based on the ensemble algorithm to classify actions and verify its validity.
Design/methodology/approach
Nine types of daily actions were collected by the wearable sensor device from a group of elderly volunteers, and the time-domain features of the action sequences were extracted. The dimensionality of the feature vectors was reduced by linear discriminant analysis. An ensemble learning method based on XGBoost was used to build a model of elderly action recognition. Its performance was compared with the action recognition rate of other algorithms based on the Boosting algorithm, and with the accuracy of single classifier models.
Findings
The effectiveness of the method was validated by three experiments. The results show that XGBoost is able to classify nine daily actions of the elderly and achieve an average recognition rate of 94.8 per cent, which is superior to single classifiers and to other ensemble algorithms.
Practical implications
The research could have important implications for health care, including the treatment and rehabilitation of the elderly, and the prevention of falls.
Originality/value
Instead of using a single type of sensor, this research used a wearable sensor to obtain daily action data of the elderly. The results show that, by using the appropriate method, the device can obtain detailed data of joint action at a low cost. Comparing differences in performance, it was concluded that XGBoost is the most suitable algorithm for building a model of elderly action recognition. This method, together with a wearable sensor, can provide key data and accurate feedback information to monitor the elderly in their rehabilitation activities.
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Weili Teng, Chenwei Ma, Saeed Pahlevansharif and Jason James Turner
The purpose of this paper is, first, to examine student perspectives of their university experience in terms of the soft employability skills they develop; second, how…
Abstract
Purpose
The purpose of this paper is, first, to examine student perspectives of their university experience in terms of the soft employability skills they develop; second, how prepared those students feel for the future employment market and finally investigate whether there are differences in perceptions between Chinese and Malaysian students given their different educational experience.
Design/methodology/approach
In this study, 361 predominantly Chinese undergraduate students at two universities, one in China and the other in Malaysia completed the 15-item Goldsmiths soft skills inventory using an online survey.
Findings
The results, analysed using factor analysis and confirmatory factor analysis, indicated that the university curriculum develops student soft skills, particularly in the Malaysian university and supports the relationship between soft skill and student preparedness for employment. The results also indicate that compared with the respondents from the Chinese university, the Malaysian university respondents were more likely to be positive to statements concerning their respective university’s ability to develop their soft skills.
Research limitations/implications
Such findings have implications for education providers and business in that it is important for universities to embed soft skills into the curriculum in order to develop graduate work readiness.
Originality/value
What this research contributes is not only consolidation of existing research in the contemporary context of a disruptive jobs market, it takes research forward through analysing student perceptions from two universities, one in Malaysia and the other in China, of the skills they develop at university and the importance of soft skills to them and their perceptions of future employment and employability. Such research will provide insight, in particular, into the role of education providers, the phenomena of underemployment among graduates in China, and be of practical significance to employers and their perception that graduates lack the necessary soft skills for the workplace (Anonymous, 2017a; Stapleton, 2017; British Council, 2015; Chan, 2015).
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Xingdong Shi, Weili Han, Yinsheng Li and Ying Huang
An enterprise application can be quickly built up by service composition. Business process composition is the essence of service composition. To build up such…
Abstract
Purpose
An enterprise application can be quickly built up by service composition. Business process composition is the essence of service composition. To build up such service‐oriented enterprise application, the developer needs an integrated design tool. The purpose of this paper is to present and integrated business‐process driven design for service‐oriented enterprise applications.
Design/methodology/approach
In the approach, there are three phases: business environment modeling, business process modeling, and script compiling. Business environment modeling adopts a new modeling technique which combines both the advantages of use case diagram and sequence diagram in UML. Business process modeling builds a concrete model according to business environment modeling. The mapping algorithms from business environment model to business process model are also given. At script compiling phase, the business process model is compiled into several deployable files. And then the paper presents a demonstration which shows how to apply our approach to developing a supply chain management system for the retail industry.
Findings
The analysis shows that the approach can meet the requirement of service‐composition. The approach can help business expert freely express their business requirement at business environment modeling phase; and help IT expert quickly design service‐oriented enterprise application according to business environment model at business process modeling phase.
Originality/value
This paper proposes a novel integrated approach to model and implement business‐process driven service composition, and presents an integrated tool based Eclipse to implement this approach.
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Hongbo Qiu, Wenfei Yu, Shuai Yuan, Bingxia Tang and Cunxiang Yang
The impact of the loop current (LC) on the motor magnetic field in the analysis of the inter-turn short circuit (ITSC) fault is always ignored. This paper made a…
Abstract
Purpose
The impact of the loop current (LC) on the motor magnetic field in the analysis of the inter-turn short circuit (ITSC) fault is always ignored. This paper made a comparative study on the electromagnetic field of permanent magnet synchronous motors (PMSM). The purpose of this study is to explore the necessary of the LC existing in the fault analysis and the electromagnetic characteristics of the PMSM with the ITSC fault when taking into account the LC.
Design/methodology/approach
Based on the finite element method (FEM), the fault model was established, and the magnetic density of the fault condition was analyzed. The induced electromotive force (EMF) and the LC of the short circuit ring were studied. The three-phase induced EMF and the unbalance of the three-phase current under the fault condition were studied. Finally, a prototype test platform was built to obtain the data of the fault.
Findings
The influence of the fault on the magnetic density was obtained. The current phase lag when the ITSC fault occurs causes the magnetic enhancement of the armature reaction. The mechanism that LC hinders the flux change was revealed. The influence of the fault on the three-phase-induced EMF symmetry, the three-phase current balance and the loss was obtained.
Originality/value
The value of the LC in the short circuit ring and the influence of it on the motor electromagnetic field were obtained. On the basis of the electromagnetic field calculation model, the sensitivity of the LC to the magnetic density, induced EMF, current and loss were analyzed.
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In order to find a way to combine traditional culture with modern living needs, taking “Chinese painting” as the breakthrough point, through the study of the development…
Abstract
In order to find a way to combine traditional culture with modern living needs, taking “Chinese painting” as the breakthrough point, through the study of the development process and artistic characteristics of Chinese painting, four aspects of classical philosophy, natural landscape image, brush and ink composition artistic conception, and abstract aesthetic conception contained in Chinese painting are summed up. The results of the study provide enlightenment for contemporary residential landscape design, and summarize the methods of creating Chinese paintings in residential landscape design. Thus, a residential landscape model with the characteristics of “Chinese painting” is found out.
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Discusses housing reform and its impact on the governance of housing in China. The roles of the state and work units have been shifted from providers to enablers in the…
Abstract
Discusses housing reform and its impact on the governance of housing in China. The roles of the state and work units have been shifted from providers to enablers in the market of housing supply after the introduction of privatisation and the market mechanism. However, the role of work units in housing distribution remains almost intact. The scope of work units’ influence is more extensive than before reform. The involvement of work units as mediators in the housing market affects the performance of the market and contributes to the fluctuations and uncertainty of the market. In order to tackle the new problems arising from reform, the role of work units needs to be redefined.
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Linda Trinh Vo and Mary Yu Danico
Examines the demographic transformation of Orange County, Los Angeles, USA and the designation of districts known as Little Saigon and Koreatown. Contends that Orange…
Abstract
Examines the demographic transformation of Orange County, Los Angeles, USA and the designation of districts known as Little Saigon and Koreatown. Contends that Orange County is fifth in the USA for fastest growing Asian communities. Uses a comparative social ecology approach to show how Koreans and Vietnamese have managed to establish their ethnic communities. Finally discusses the challenges faced in sustaining their communities, given the resistance from Anglo residents for “foreigners”.
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