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Article
Publication date: 13 June 2019

Rui Zhang, Lei Zhao, Dan Xie, Jinlong Song, Wendong Zhang, Lihu Pan and Yanhua Zhang

This study aims to simulate and test the performance of a transmitting and receiving capacitive micro-machined ultrasonic transducer (CMUT). Aimed at detecting demand of…

139

Abstract

Purpose

This study aims to simulate and test the performance of a transmitting and receiving capacitive micro-machined ultrasonic transducer (CMUT). Aimed at detecting demand of the CMUT, a matched integrated adjustment circuit was designed through analyzing processing methods of transducer’s weak echo signal.

Design/methodology/approach

Based on the analysis of CMUT array structure and work principle, the CMUT units are designed and the dynamic performance analysis of SIMULINK is given according to the demand of underwater detecting. A transceiver isolation circuit is used to make transmission mode and receiving mode separate. A detection circuit is designed based on the transimpedance amplifier to achieve extraction of high-frequency and weak signal.

Findings

Through experimentation, the effectiveness of the CMUT performance simulation and the transceiver integrated adjustment circuit were verified. In addition, the test showed that CMUT with 400 kHz frequency has wider bandwidth and better dynamic characteristics than other similar transducers.

Originality/value

This paper provides a theoretical basis and design reference for the development and application of CMUT technology.

Article
Publication date: 1 September 2021

Yi Zhang Rui Huang

With the booming development of computer, optical and sensing technologies and cybernetics, the technical research in unmanned vehicle has been advanced to a new era. This…

Abstract

Purpose

With the booming development of computer, optical and sensing technologies and cybernetics, the technical research in unmanned vehicle has been advanced to a new era. This trend arouses great interest in simultaneous localization and mapping (SLAM). Especially, light detection and ranging (Lidar)-based SLAM system has the characteristics of high measuring accuracy and insensitivity to illumination conditions, which has been widely used in industry. However, SLAM has some intractable problems, including degradation under less structured or uncontrived environment. To solve this problem, this paper aims to propose an adaptive scheme with dynamic threshold to mitigate degradation.

Design/methodology/approach

We propose an adaptive strategy with a dynamic module is proposed to overcome degradation of point cloud. Besides, a distortion correction process is presented in the local map to reduce the impact of noise in the iterative optimization process. Our solution ensures adaptability to environmental changes.

Findings

Experimental results on both public data set and field tests demonstrated that the algorithm is robust and self-adaptive, which achieved higher localization accuracy and lower mapping error compared with existing methods.

Originality/value

Unlike other popular algorithms, we do not rely on multi-sensor fusion to improve the localization accuracy. Instead, the pure Lidar-based method with dynamic threshold and distortion correction module indeed improved the accuracy and robustness in localization results.

Details

Sensor Review, vol. 41 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 19 June 2017

Liubov Skavronskaya, Noel Scott, Brent Moyle, Dung Le, Arghavan Hadinejad, Rui Zhang, Sarah Gardiner, Alexandra Coghlan and Aishath Shakeela

This review aims to discuss concepts and theories from cognitive psychology, identifies tourism studies applying them and discusses key areas for future research. The…

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Abstract

Purpose

This review aims to discuss concepts and theories from cognitive psychology, identifies tourism studies applying them and discusses key areas for future research. The paper aims to demonstrate the usefulness of cognitive psychology for understanding why tourists and particularly pleasure travellers demonstrate the behaviour they exhibit.

Design/methodology/approach

The paper reviews 165 papers from the cognitive psychology and literature regarding pleasure travel related to consciousness, mindfulness, flow, retrospection, prospection, attention, schema and memory, feelings and emotions. The papers are chosen to demonstrate the state of the art of the literature and provide guidance on how these concepts are vital for further research.

Findings

The paper demonstrates that research has favoured a behaviourist rather than cognitive approach to the study of hedonic travel. Cognitive psychology can help to understand the mental processes connecting perception of stimuli with behaviour. Numerous examples are provided: top-down and bottom-up attention processes help to understand advertising effectiveness, theories of consciousness and memory processes help to distinguish between lived and recalled experience, cognitive appraisal theory predicts the emotion elicited based on a small number of appraisal dimensions such as surprise and goals, knowledge of the mental organisation of autobiographical memory and schema support understanding of destination image formation and change and the effect of storytelling on decision-making, reconstructive bias in prospection or retrospection about a holiday inform the study of pleasurable experience. These findings indicate need for further cognitive psychology research in tourism generally and studies of holiday travel experiences.

Research limitations/implications

This review is limited to cognitive psychology and excludes psychoanalytic studies.

Practical implications

Cognitive psychology provides insight into key areas of practical importance. In general, the use of a cognitive approach allows further understanding of leisure tourists’ behaviour. The concept of attention is vital to understand destination advertising effectiveness, biases in memory process help to understand visitor satisfaction and experience design and so on. Use of cognitive psychology theory will lead to better practical outcomes for tourists seeking pleasurable experiences and destination managers.

Originality value

This is the first review that examines the application of concepts from cognitive psychology to the study of leisure tourism in particular. The concepts studied are also applicable to study of travellers generally.

Details

Tourism Review, vol. 72 no. 2
Type: Research Article
ISSN: 1660-5373

Keywords

Article
Publication date: 25 May 2022

Xiongying Niu, Baofang Zhang, Mulele Simasiku and Rui Zhang

This study aims to explore the effect of expatriate supervisors’ managerial coaching behavior on local subordinates’ learning effects through the mediating role of…

Abstract

Purpose

This study aims to explore the effect of expatriate supervisors’ managerial coaching behavior on local subordinates’ learning effects through the mediating role of subordinates’ thriving at work under the boundary condition of expatriate supervisors’ cultural intelligence.

Design/methodology/approach

This study collected the data form 230 Zambian subordinates and their immediate expatriate supervisors working in the Chinese company in Zambia. Regression analyses and bootstrapping analyses were used to test the authors’ hypothesis.

Findings

The results indicated that expatriate supervisors’ managerial coaching behavior was positively related to local subordinates’ learning effects. In addition, the study also found that local subordinates’ thriving at work mediated the linkage between managerial coaching behavior and learning effects. And expatriate supervisors’ cultural intelligence moderated the indirect relationship between managerial coaching behavior and learning effects via thriving at work, such that the indirect effect was stronger for expatriate supervisors with high rather than low cultural intelligence.

Originality/value

This study contributes to a better understanding of how expatriate supervisors’ managerial coaching behavior influences local subordinates’ learning effects by investigating the mediating effect of thriving at work on the managerial coaching behavior–learning effects link. In addition, the study deepens the understanding of the boundary condition of the associations between managerial coaching behavior and subordinates’ learning effects in a cross-cultural context by investigating the moderating effect of expatriate supervisors’ cultural intelligence.

Details

Chinese Management Studies, vol. 16 no. 4
Type: Research Article
ISSN: 1750-614X

Keywords

Article
Publication date: 14 March 2016

Rui Zhang and Binjie Xin

The purpose of this paper is introducing the image processing technology used for fabric analysis, which has the advantages of objective, digital and quick response.

Abstract

Purpose

The purpose of this paper is introducing the image processing technology used for fabric analysis, which has the advantages of objective, digital and quick response.

Design/methodology/approach

This paper briefly describes the key process and module of some typical automatic recognition systems for fabric analysis presented by previous researchers; the related methods and algorithms used for the texture and pattern identification are also introduced.

Findings

Compared with the traditional subjective method, the image processing technology method has been proved to be rapid, accurate and reliable for quality control.

Originality/value

The future trends and limitations in the field of weave pattern recognition for woven fabrics have been summarized at the end of this paper.

Details

Research Journal of Textile and Apparel, vol. 20 no. 1
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 16 October 2018

Khurram Ashfaq and Zhang Rui

This study aims to revisit the corporate social and environmental disclosure (CSED) practices of Pakistani companies using unique CSED index which measures the CSED…

Abstract

Purpose

This study aims to revisit the corporate social and environmental disclosure (CSED) practices of Pakistani companies using unique CSED index which measures the CSED through three dimensions such as theme, news type and nature of information. In addition, the effect of board composition, ownership structure and corporate characteristics on CSED was tested through performing multiple regression analysis.

Design/methodology/approach

For this purpose, data were collected from annual reports of top 120 companies’ selected based on market capitalization for three years period of 2013-2015.

Findings

Based on the descriptive statistics, the results found that overall level of CSED in Pakistan is moderate. However considering CSED using three dimensions, the results demonstrate that highest level of disclosure on the basis of theme is reported in terms of human resource category as compared to other categories where, as in terms of news type and nature of information, analysis shows that companies in Pakistan feel resistant to disclose bad news, monetary and non-monetary aspect of CSED information. Using multiple regression analysis, the results found that all the variables have hypothesized relationship with CSED except government and institutional ownership. The variables such as chairman as non-executive director, board diversity, appointment of independent director as audit committee chairman, CSR committee, industry type and firm size are found to have significant influence on the CSED practices in Pakistan.

Research limitations/implications

These results imply that the CSED phenomenon is still lacking behind. Under individual categories of CSED, descriptive statistics found that environment is still not a matter of concern for companies operating in Pakistan. In addition, the results demonstrate that CSED practices are only performed by very few companies in Pakistan based on standard deviation. In addition, appointment of non-executive and independent director as chairman of board and audit committee and representation of foreigners on the board should be encouraged in order to improve CSED practices in Pakistan.

Originality/value

This study contributes to the existing literature in developing country like Pakistan through using unique CSED index and also making comparison of financial versus non-financial sectors. The author suggests that regulatory authorities in Pakistan must take reasonable steps to make the company’s operations environment-friendly.

Details

Social Responsibility Journal, vol. 15 no. 1
Type: Research Article
ISSN: 1747-1117

Keywords

Article
Publication date: 28 February 2022

Rui Zhang, Na Zhao, Liuhu Fu, Lihu Pan, Xiaolu Bai and Renwang Song

This paper aims to propose a new ultrasonic diagnosis method for stainless steel weld defects based on multi-domain feature fusion to solve two problems in the ultrasonic…

Abstract

Purpose

This paper aims to propose a new ultrasonic diagnosis method for stainless steel weld defects based on multi-domain feature fusion to solve two problems in the ultrasonic diagnosis of austenitic stainless steel weld defects. These are insufficient feature extraction and subjective dependence of diagnosis model parameters.

Design/methodology/approach

To express the richness of the one-dimensional (1D) signal information, the 1D ultrasonic testing signal was derived to the two-dimensional (2D) time-frequency domain. Multi-scale depthwise separable convolution was also designed to optimize the MobileNetV3 network to obtain deep convolution feature information under different receptive fields. At the same time, the time/frequent-domain feature extraction of the defect signals was carried out based on statistical analysis. The defect sensitive features were screened out through visual analysis, and the defect feature set was constructed by cascading fusion with deep convolution feature information. To improve the adaptability and generalization of the diagnostic model, the authors designed and carried out research on the hyperparameter self-optimization of the diagnostic model based on the sparrow search strategy and constructed the optimal hyperparameter combination of the model. Finally, the performance of the ultrasonic diagnosis of stainless steel weld defects was improved comprehensively through the multi-domain feature characterization model of the defect data and diagnosis optimization model.

Findings

The experimental results show that the diagnostic accuracy of the lightweight diagnosis model constructed in this paper can reach 96.55% for the five types of stainless steel weld defects, including cracks, porosity, inclusion, lack of fusion and incomplete penetration. These can meet the needs of practical engineering applications.

Originality/value

This method provides a theoretical basis and technical reference for developing and applying intelligent, efficient and accurate ultrasonic defect diagnosis technology.

Article
Publication date: 10 August 2018

Ming Qiu, Rui Zhang, Yingchun Li, Hui Du and Xiao Xu Pang

The MoS2/graphite composite coatings modified by La2O3 through spraying technique were successfully prepared on the inner rings of spherical plain bearings. As a…

Abstract

Purpose

The MoS2/graphite composite coatings modified by La2O3 through spraying technique were successfully prepared on the inner rings of spherical plain bearings. As a comparison, unmodified coatings were also prepared. This paper aims to study the La-modified MoS2/graphite composite coating experimentally and improve the tribological performance of self-lubricating spherical plain bearings.

Design/methodology/approach

The performance of La2O3 toward the friction coefficient, temperature rise and wear rate of the coatings was studied by a self-made tribo-tester under different swing cycles. And the texture, surface morphology and element composition of the coatings were characterized by scanning electron microscope, energy dispersive spectroscopy and X-ray diffractometry.

Findings

The additives La2O3 refined the coatings’ microstructure and improved the tribological properties of the coatings. The oxidation of Mo + 4 to Mo + 6 was effectively inhibited. And the amount of abrasive grains, peeling pits and local cracks on the coatings surface decreased and homogeneous lubricating films formed, which were attributed to the existence of La2O3. The wear mechanisms of unmodified coatings were severe abrasive wear, adhesive wear and delamination wear. However, it exhibited superior wear resistance of the La-modified coatings to unmodified coatings, presenting slight abrasive wear and adhesive wear. The service life of bearings was prolonged under the protection of the modified coatings.

Originality/value

The paper proposed a new modified MoS2/Graphite composite coating for the self-lubricating spherical plain bearings. The investigation on the friction, wear and temperature increase behaviors and the wear mechanisms of the coatings are beneficial to prolonging the service life of the self-lubricating spherical plain bearings.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 10 September 2020

Zhiming Zhao, Rui Zhang, Feng Ji and Xiaoyang Yuan

High power and speed are new demands for rotating machinery which needs the journal bearings with high dynamic characteristics. The critical speed of the rotor-bearing…

Abstract

Purpose

High power and speed are new demands for rotating machinery which needs the journal bearings with high dynamic characteristics. The critical speed of the rotor-bearing system is one of the most significant parameters to evaluate the dynamic characteristics. This paper aims to investigate the theoretical and experimental analysis of a rotor system supported by large diameter elliptical bearings.

Design/methodology/approach

To obtain the theoretical and experimental support for rotor-bearing system design, dynamic characteristics theoretical analysis based on the finite difference method is given and an experiment focuses on critical speed identification is carried out.

Findings

The theoretical calculation results indicate that the critical speed is near to 800 rpm and there is no large vibration amplitude round working speed (1,500 rpm). Using the test bench in the factory unit, vibration data including three experimental processes are obtained. According to the vibration data, the critical speed is identified which also indicates that it is stable when working at 1,500 rpm.

Originality/value

The design method for the rotor system supported by large diameter elliptical bearing can be obtained by the theoretical and experimental results shown in this paper.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0122/

Details

Industrial Lubrication and Tribology, vol. 73 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 12 April 2022

Peng Xue, Jie Zheng, Yue Xu, Haiyang Bao and Rui Zhang

This study aims to analyze the transmission characteristics of a long-period grating (LPG) fabricated on plastic optical fibers (POFs) and its refractive index (RI) sensing.

Abstract

Purpose

This study aims to analyze the transmission characteristics of a long-period grating (LPG) fabricated on plastic optical fibers (POFs) and its refractive index (RI) sensing.

Design/methodology/approach

The geometric optic method is used to analyze the factors affecting the transmission characteristics of an LPG on POFs. The RI sensing performances of unbent LPGs and U-bent LPGs fabricated on POFs with different diameters are evaluated experimentally.

Findings

This study shows that the transmission loss caused by LPG strongly depends on the structural parameters of LPG and the environmental RI. For the unbent LPG, the highest RI sensitivity of 1,015%/RI unit (RIU) was obtained in the RI range of 1.33–1.45. For the U-bent LPG without cladding, the highest RI sensitivities of 1,007 and 559%/RIU are obtained in the RI ranges of 1.33–1.40 and 1.40–1.45, respectively.

Originality/value

A geometric optic method is used to analyze the transmission characteristics for an LPG on POFs, and the RI sensing of the LPGs are studied experimentally. The results show the LPG has a good RI sensing performances and is with the features of low-cost, simple structure and easy fabrication.

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