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Article
Publication date: 9 July 2021

Zhongcheng Gui, Xinran Zhong, Yuchen Wang, Tangjie Xiao, Yongjun Deng, Hui Yang and Rui Yang

This paper aims to present a novel robotic system for airport pavement inspection tasks.

268

Abstract

Purpose

This paper aims to present a novel robotic system for airport pavement inspection tasks.

Design/methodology/approach

The cloud-edge-terminal-based distributed architecture is designed for the proposed robotic system. Then, the following three major parts are designed and deployed, respectively: Terminal: the wheeled-robot-based data collection system. Edge: remote monitoring and data analysis system. Cloud: shared database center of the inspection data and knowledge.

Findings

Validation and application results show that the proposed system satisfies the demands of automated airport pavement inspection tasks and saves the cost of manpower and time.

Originality/value

The proposed system provides a novel solution for the full process of airport pavement inspection. Compared with the traditional manual method, the robotic system can guarantee complete coverage and provide high-precision pavement inspection results with less time and labor costs.

Details

Industrial Robot: the international journal of robotics research and application, vol. 48 no. 6
Type: Research Article
ISSN: 0143-991X

Keywords

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Article
Publication date: 20 October 2014

Zhongcheng Gui, Yongjun Deng, Zhongxi Sheng, Tangjie Xiao, Yonglong Li, Fan Zhang, Na Dong and Jiandong Wu

This paper aims to present a new intelligent wall-climbing welding robot system for large-scale steel structure manufacture, which is composed of robot body, control system and…

587

Abstract

Purpose

This paper aims to present a new intelligent wall-climbing welding robot system for large-scale steel structure manufacture, which is composed of robot body, control system and welding system.

Design/methodology/approach

The authors design the robot system according to application requirements, validate the design through simulation and experiments and use the robot in actual production.

Findings

Experimental results show that the robot system satisfies the demands of automatic welding of large-scale ferromagnetic structure, which contributes much to on-site manufacturing of such structures.

Practical implications

The robot can work with better quality and efficiency compared with manual welding and other semi-automatic welding devices, which can much improve large-scale steel structure manufacturing.

Originality/value

The robot system is a novel solution for large-scale steel structures welding. There are three major advantages: the robot body with reliable adsorption ability, large payload capability and good mobility which meet the requirements of welding; the control system with good welding seam tracking accuracy and intelligent automatic welding ability; and friendly human – computer interface which makes the robot easy to use.

Details

Industrial Robot: An International Journal, vol. 41 no. 6
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 28 April 2022

Yongjun Jin, Haihang Cui, Li Chen, Zhe Liu and Kai Sun

The purpose of this paper is to study the mechanism of efficient sputum excretion from the distal lung by using a tessellationally distal lung model with alveolar pores.

98

Abstract

Purpose

The purpose of this paper is to study the mechanism of efficient sputum excretion from the distal lung by using a tessellationally distal lung model with alveolar pores.

Design/methodology/approach

First, a two-dimensional tessellational composite structure of the bronchus, alveoli and alveolar pores (Kohn pore) is constructed with the tessellational splitting and fusion of regular hexagonal elements. Then, the level set method is used to study the effects of alveolar pores and their sizes, expiratory cycles and respiratory intensity.

Findings

The existence of alveolar pores is the prerequisite for sputum excretion, and there is an optimal size of alveolar pores for sputum excretion. Strong asymmetric respiration can break the reversibility of the flow at a low Reynolds number and causes significant net displacement of sputum. The expiratory cycle is negatively correlated with the net displacement of sputum. The respiratory intensity is positively correlated with the net displacement of sputum.

Originality/value

This research is helpful for understanding the complex sputum excretion process in diseases, such as pneumonia, and developing corresponding adjuvant therapy.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 12
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 19 May 2022

Yongjun Jin, Haihang Cui, Li Chen, Kai Sun, Haiguo Yin and Zhe Liu

This study aims to perform flow simulations inside the acinus with fine alveolar pores (Kohn pores) using hexagonal cells and bottom-up geometric modeling, which enabled the…

95

Abstract

Purpose

This study aims to perform flow simulations inside the acinus with fine alveolar pores (Kohn pores) using hexagonal cells and bottom-up geometric modeling, which enabled the elimination of invalid voids using previous top-bottom methods and spherical or circular cells.

Design/methodology/approach

Regular hexagonal cells were used to construct alveoli with no gaps via tessellation. Some hexagonal cells were fused to eliminate the inner boundaries to represent the structure of the bronchial tree. For the remaining hexagonal cells, the side lengths of the shared walls were adjusted to construct alveolar pores. Periodic moving boundaries with the same phase were set for all walls to describe synchronous contraction and expansion of the bronchi and alveoli.

Findings

More realistic flow characteristics in the distal lung were obtained. The effects of pore size and the mechanism of auxiliary ventilation of alveolar pores were revealed.

Originality/value

To the best of the authors’ knowledge, this is the first numerical simulation study on the function of multiple alveolar pores at the level of pulmonary acini, which will be helpful for simulating the dynamic process of cough and sputum excretion in the future.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 9 December 2024

Hanbing Xue, Qianzhou Du, Jin Liu and Yongjun Li

This study aims to investigate the moderating effects of individual social engagement on the effectiveness of freemium strategies in digital content platforms.

40

Abstract

Purpose

This study aims to investigate the moderating effects of individual social engagement on the effectiveness of freemium strategies in digital content platforms.

Design/methodology/approach

This study involved conducting a randomized field experiment with 74,758 consumers on a prominent e-book platform in China, comparing the effects of offering the first 50 chapters for free against no free content. Additionally, a causal random forest machine learning algorithm was applied to analyze data and optimize strategies based on individual social engagement levels.

Findings

This study indicates freemium strategies on digital content platforms can increase consumer willingness to pay but may reduce social community participation. These effects are moderated by consumers' prior social engagement, with excessive interaction leading to diminishing returns.

Practical implications

The study offers actionable insights for digital content managers, showing how tailored freemium strategies can effectively balance consumer engagement and revenue generation. The findings suggest that platforms can significantly enhance profitability by moderating free content offerings based on detailed analysis of consumer engagement histories.

Originality/value

This study enhances the understanding of freemium strategies by showcasing their dual impact on consumer willingness to pay and social engagement, and detailing the complex, non-linear effects of individual social engagement, which challenges the traditional linear assumptions in existing literature. Additionally, it provides insights for implementing mixed marketing strategies on digital platforms, where multiple strategies often interact, guiding the effective management of these complexities.

Details

Industrial Management & Data Systems, vol. 125 no. 1
Type: Research Article
ISSN: 0263-5577

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Article
Publication date: 3 September 2024

Deyong Ma and Yongjun Ma

The purpose of this paper is to test if the digital economy improves the quality of life of our residents. Furthermore, if this finding is confirmed, what would be the mechanism…

48

Abstract

Purpose

The purpose of this paper is to test if the digital economy improves the quality of life of our residents. Furthermore, if this finding is confirmed, what would be the mechanism behind its effect? Does the impact of the digital economy on quality of life vary according to its level of development?

Design/methodology/approach

A comprehensive index of the digital economy, income gap and quality of life was constructed empirically based on data from 220 cities in China from 2011–2020. A multi-dimensional empirical analysis was conducted in this paper.

Findings

The analysis of the pathways of action shows that narrowing the income gap is an important mechanism through which the digital economy actively contributes to the quality of life. The results of the threshold model show that the “marginal effect” of the digital economy on quality of life is non-linear and increasing. The results show that after a series of robustness tests, including instrumental variables, the digital economy still significantly enhances people’s quality of life.

Research limitations/implications

This paper reveals the intrinsic link between the digital economy and quality of life and provides a theoretical basis for further improving people’s well-being.

Practical implications

Encouraging the development of the digital economy is a useful way to improve the quality of life by narrowing the income gap.

Originality/value

Data analysis of the digital economy from 2011–2020 in China to get an insight into what would be the mechanism behind the digital economy improving the quality of life of our residents.

Details

Digital Policy, Regulation and Governance, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2398-5038

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Article
Publication date: 12 November 2024

Jia Wang, Haiyang Sun, Ding Chen, Yongjun Huang, Tao Dong, Hai Li, Lingnan Shen and Ziyu Yang

The paper aims to accurately measure the key motion parameters, such as velocity, azimuth and pitch angle, of the small flying object with a non-uniform curve trajectory. It…

14

Abstract

Purpose

The paper aims to accurately measure the key motion parameters, such as velocity, azimuth and pitch angle, of the small flying object with a non-uniform curve trajectory. It proposes a measurement method and its calculation model of non-uniform curve trajectory using a photoelectric sensor array.

Design/methodology/approach

First, the basic composition of the measurement system and mechanism of photoelectric sensor array are described, respectively. Second, a non-uniform curve mathematical measurement model is constructed differently from the traditional linear trajectory, taking into account the influence of gravity and air resistance. Third, the measurement error of the system is analyzed through numerical simulation. Finally, the accuracy and feasibility of the approach are verified by live-ammunition experiments.

Findings

The results show that the systematic error of the hitting point coordinates can be reduced by 9% compared to the traditional linear measurement model. Consequently, this method can meet the higher measurement requirement for the key motion parameters of the small flying object under the non-uniform curve trajectory. Research limitations/implications (if applicable)- although the approach itself is generalizable, the method is unable to detect the motion parameters of multiple small flying objects.

Research limitations/implications

Although the approach itself is generalizable, the method is unable to detect the motion parameters of the multiple small flying objects.

Practical implications

It is evident that the proposed non-uniform curve measurement model is more precise in quantifying the essential characteristics of the small flying object, particularly in consideration of the environmental conditions.

Social implications

The precise measurement of the key motion parameters of the small flying object can facilitate the enhancement of the protective performance of protective materials.

Originality/value

A novel approach to measurement is proposed, which differs from the conventional uniform trajectory model. To this end, the space construction of the photoelectric sensor array is optimized. The number of the sensors is revised.

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Article
Publication date: 22 April 2022

Lijun Shang, Qingan Qiu, Cang Wu and Yongjun Du

The study aims to design the limited number of random working cycle as a warranty term and propose two types of warranties, which can help manufacturers to ensure the product…

153

Abstract

Purpose

The study aims to design the limited number of random working cycle as a warranty term and propose two types of warranties, which can help manufacturers to ensure the product reliability during the warranty period. By extending the proposed warranty to the consumer's post-warranty maintenance model, besides the authors investigate two kinds of random maintenance policies to sustain the post-warranty reliability, i.e. random replacement first and random replacement last. By integrating depreciation expense depending on working time, the cost rate is constructed for each random maintenance policy and some special cases are provided by discussing parameters in cost rates. Finally, sensitivities on both the proposed warranty and random maintenance policies are analyzed in numerical experiments.

Design/methodology/approach

The working cycle of products can be monitored by advanced sensors and measuring technologies. By monitoring the working cycle, manufacturers can design warranty policies to ensure product reliability performance and consumers can model the post-warranty maintenance to sustain the post-warranty reliability. In this article, the authors design a limited number of random working cycles as a warranty term and propose two types of warranties, which can help manufacturers to ensure the product reliability performance during the warranty period. By extending a proposed warranty to the consumer's post-warranty maintenance model, the authors investigate two kinds of random replacement policies to sustain the post-warranty reliability, i.e. random replacement first and random replacement last. By integrating a depreciation expense depending on working time, the cost rate is constructed for each random replacement and some special cases are provided by discussing parameters in the cost rate. Finally, sensitivities to both the proposed warranties and random replacements are analyzed in numerical experiments.

Findings

It is shown that the manufacturer can control the warranty cost by limiting number of random working cycle. For the consumer, when the number of random working cycle is designed as a greater warranty limit, the cost rate can be reduced while the post-warranty period can't be lengthened.

Originality/value

The contribution of this article can be highlighted in two key aspects: (1) the authors investigate early warranties to ensure reliability performance of the product which executes successively projects at random working cycles; (2) by integrating random working cycles into the post-warranty period, the authors is the first to investigate random maintenance policy to sustain the post-warranty reliability from the consumer's perspective, which seldom appears in the existing literature.

Details

Journal of Quality in Maintenance Engineering, vol. 29 no. 2
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 8 August 2016

Brenda Killingsworth, Yajiong Xue and Yongjun Liu

This paper aims to examine interrelations of the team environment factors of trust and affiliation and the motivation factors of perceived reciprocal benefits and importance of…

4913

Abstract

Purpose

This paper aims to examine interrelations of the team environment factors of trust and affiliation and the motivation factors of perceived reciprocal benefits and importance of enjoyment to determine how they influence knowledge sharing within loose-linked global virtual teams.

Design/methodology/approach

The study involved 115 business students from three large universities located in the USA, China and Peru being assigned to global virtual teams of between three and four members in one phase and between four and seven members in a second phase. Students were required to work in virtual teams using telecommunication tools to complete assigned cases.

Findings

Trust, reciprocal benefits and enjoyment are significantly related to positive attitude toward knowledge sharing. Positive attitude, enjoyment, age, nationality and computer experience are positively related to knowledge sharing behavior. Affiliation is not found to significantly affect positive knowledge sharing attitude. Gender is not related to knowledge sharing behavior.

Practical implications

Understanding how trust, affiliation and motivation influence positive attitude and knowledge sharing behavior can assist managers in developing intervention strategies that improve team environments to support knowledge sharing behavior.

Originality/value

This paper contributes to the advancement of theory by extending the current knowledge sharing research to virtual team environments with diverse cultural backgrounds and by considering both extrinsic and intrinsic motivation factors, including the importance of enjoyment in loose-linked environments of global virtual teams.

Details

Team Performance Management, vol. 22 no. 5/6
Type: Research Article
ISSN: 1352-7592

Keywords

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Article
Publication date: 7 March 2016

WenRuo Zhu, ZhongXin Gao, YongJun Tang, JianGuang Zhang and Li Lu

The purpose of this paper is to analyze the ability of turbulence models to model the flow field in the runner of a Francis turbine. Although the complex flow in the turbine can…

866

Abstract

Purpose

The purpose of this paper is to analyze the ability of turbulence models to model the flow field in the runner of a Francis turbine. Although the complex flow in the turbine can be simulated by CFD models, the prediction accuracy still needs to be improved. The choice of the turbulence model is one key tool that affects the prediction accuracy of numerical simulations.

Design/methodology/approach

This study used the SST k-w and RNG k-e turbulence models, which can both accurately predict complex flow fields in numerical simulations, to simulate the flow in the entire flow passage of a Francis turbine with the results compared against experimental data for the performance and blade pressure distribution in the turbine to evaluate the applicability of the turbulence models.

Findings

The results show that the SST k-w turbulence model more accurately predicts the turbine performance than the RNG turbulence model. However, the blade surface pressures predicted by the SST k-w turbulence model were basically identical to those predicted by the RNG k-e turbulence model, with both accurately predicting the experimental data.

Research limitations/implications

Due to the lack of space, the method used to measure the blade surface pressure distributions is not introduced in this paper.

Practical implications

Turbine performance and flow field pressure in the runner, which are the basis of turbine preliminary performance judgment and optimization through CFD, can be used to judge the rationality of the turbine runner design. The paper provides an evidence for the turbulence selection in numerical simulation to predict turbine performance and flow field pressure in the runner and improves the CFD prediction accuracy.

Originality/value

This paper fulfils a test of the flow field pressure in the runner, which provide an evidence for judge the adaptability of turbulence model on the flow field in runner. And this paper also provides important evaluations of two turbulence models for modeling the flow field pressure distribution in the runner of a Francis turbine to improve the accuracy of CFD models for predicting turbine performance.

Details

Engineering Computations, vol. 33 no. 1
Type: Research Article
ISSN: 0264-4401

Keywords

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