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Article
Publication date: 14 September 2015

Chuanjun Liao, Xibao Xu, Hongrong Fang, Hongrui Wang and Man Man

The purpose of this paper is to develop a leakage model of metallic static seals, which can be used to accurately predict the leakage rate and study the corresponding seal…

252

Abstract

Purpose

The purpose of this paper is to develop a leakage model of metallic static seals, which can be used to accurately predict the leakage rate and study the corresponding seal characteristics. The metallic static seal is effectively applied to severe rugged environments where conventional seals cannot meet the needs. More research efforts for deepening the understanding of its seal characteristics are important for its effective and safe applications, of which the study about its leak is one key component.

Design/methodology/approach

In the microscopic observations of the turning surface that is general in the processing of flange surfaces, it is found that the spiral morphology is dominant, which had been also obtained by other researches. There are two potential leakage paths for the flange surface of spiral morphology, one is the radial direction perpendicular to the spiral ridges and the other is the circumferential direction along the spiral groove. Based on the microgeometry characteristics of spiral morphology, the micromorphology of turning flange surface is simplified for the calculation of leakage rate, and the simplified methods of the radial and circumferential leakage paths are presented separately. The topography of flange surface studied in this paper is actually measured, and the Abbott bearing surface curve is adopted to represent the micro-profiles parameters. The radial and circumferential leakage models are further developed based on the assumption of laminar flow of the viscous compressible gas.

Findings

The experiments used to verify the leakage models were carried out, and the experimental values are well agreed with the calculated values. As the contact pressure increases, the change rules of both radial and circumferential leakage rates are obtained and the obvious transition from radial leak to circumferential leak can be found. Using the proposed leakage models, the effects of the key micro-profiles parameters on the leakage rates are studied, and some specific conclusions are given simultaneously, which are favorable for the theoretical study and practical application of the metallic static seal.

Practical implications

By the interpretations of the micromorphology characteristics of turning flange surface, the leakage mechanism of the metallic static seal is further made clear. The proposed leakage model reveals the relationships between the key micro-profiles parameters and some sealing performances about the leakage and can predict the leakage rates of the metallic static seal used in various working conditions.

Originality/value

For the metallic static seal, the simplification of the radial leakage path and the radial leakage model are put forward for the first time, so the total leakage model can be systematically reported based on the micromorphology characteristics of turning flange surface. The effects of the key micro-profiles parameters on the seal behaviors including of the leak rate, critical contact pressure and transition from radial leak to circumferential leak etc are also clarified firstly.

Details

Industrial Lubrication and Tribology, vol. 67 no. 6
Type: Research Article
ISSN: 0036-8792

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Book part
Publication date: 7 May 2019

Hans-Michael Trautwein

Abstract

Details

Including A Symposium on 50 Years of the Union for Radical Political Economics
Type: Book
ISBN: 978-1-78769-849-9

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Article
Publication date: 13 March 2024

Rong Jiang, Bin He, Zhipeng Wang, Xu Cheng, Hongrui Sang and Yanmin Zhou

Compared with traditional methods relying on manual teaching or system modeling, data-driven learning methods, such as deep reinforcement learning and imitation learning, show…

266

Abstract

Purpose

Compared with traditional methods relying on manual teaching or system modeling, data-driven learning methods, such as deep reinforcement learning and imitation learning, show more promising potential to cope with the challenges brought by increasingly complex tasks and environments, which have become the hot research topic in the field of robot skill learning. However, the contradiction between the difficulty of collecting robot–environment interaction data and the low data efficiency causes all these methods to face a serious data dilemma, which has become one of the key issues restricting their development. Therefore, this paper aims to comprehensively sort out and analyze the cause and solutions for the data dilemma in robot skill learning.

Design/methodology/approach

First, this review analyzes the causes of the data dilemma based on the classification and comparison of data-driven methods for robot skill learning; Then, the existing methods used to solve the data dilemma are introduced in detail. Finally, this review discusses the remaining open challenges and promising research topics for solving the data dilemma in the future.

Findings

This review shows that simulation–reality combination, state representation learning and knowledge sharing are crucial for overcoming the data dilemma of robot skill learning.

Originality/value

To the best of the authors’ knowledge, there are no surveys that systematically and comprehensively sort out and analyze the data dilemma in robot skill learning in the existing literature. It is hoped that this review can be helpful to better address the data dilemma in robot skill learning in the future.

Details

Robotic Intelligence and Automation, vol. 44 no. 2
Type: Research Article
ISSN: 2754-6969

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Article
Publication date: 7 June 2022

Mehri Yasami, Md. Karim Rabiul, Pornpisanu Promsivapallop and Hongrui Zhu

The purpose of this study is to integrate the theory of planned behavior and the protection motivation theory to propose a theoretical framework for examining the influence of…

928

Abstract

Purpose

The purpose of this study is to integrate the theory of planned behavior and the protection motivation theory to propose a theoretical framework for examining the influence of attitude, perceived behavioral control and subjective norms on international tourists’ intentions to select restaurants with contactless dining services (CDSs) as a protective behavior against COVID-19. This study further tested the moderation effects of subjective norms on attitude and perceived behavioral control links with intention.

Design/methodology/approach

In all, 344 international tourists completed questionnaires via QR-coded Google forms in Phuket Old Town and Patong Beach in Thailand. Data analysis was conducted by SPSS and Smart-PLS (partial least square).

Findings

Intention to select a restaurant with CDSs was influenced by attitude, perceived behavioral control and subjective norms. Subjective norms had a significant negative moderating effect on attitude and intention links. However, the moderation effect of tourists’ subjective norms on the connection between their perceived behavioral control and intention toward restaurant dining was not proved.

Practical implications

Providing CDSs could be a quick solution to decrease the devastating effect of the COVID-19 pandemic on the restaurant industry.

Originality/value

This study incorporated CDSs to expand the application of the integrated model of theory of planned behavior and protection motivation theory as a theoretical basis in the restaurant industry to explain how international tourists’ behavioral choices may change during the pandemic in Thailand. This study also contributes to the travel risk literature by highlighting the influence of attitude anchored on risk and efficacy beliefs (perceived vulnerability, severity and response efficacy) in predicting protective behavioral intention.

Details

International Journal of Contemporary Hospitality Management, vol. 34 no. 11
Type: Research Article
ISSN: 0959-6119

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Article
Publication date: 27 September 2024

Kan Liu, Ziyi Zhang and Hongrui Zhou

Exploring open value, cultivating digital capability (DC) and driving business model innovation (BMI) have become an inevitable choice for enterprises to meet market demand and…

78

Abstract

Purpose

Exploring open value, cultivating digital capability (DC) and driving business model innovation (BMI) have become an inevitable choice for enterprises to meet market demand and adapt to environmental changes. However, as one of the situational variables of BMI, the positive or negative influence of openness has not been proved and the path mechanism between DC and BMI is not clear. Based on the dynamic capability theory, this paper takes manufacturing enterprises as an example to explore the internal impact mechanisms of organizational openness on BMI. It extends the analysis by introducing DC as a mediating variable and introducing manufacturing enterprise type (high-tech and non-high-tech) as a moderating variable.

Design/methodology/approach

A questionnaire survey was conducted using data collected in China, data from 355 manufacturing enterprises were collected to carry out empirical research. Participants were mainly middle and senior managers with a comprehensive grasp of their firms’ information. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to test the reliability and validity of the sample data, and negative binomial regression analysis was used to test hypothesis relationships.

Findings

The authors find an inverted U-shaped relationship between openness and BMI, and explain that excessive openness may lead to low resource utilization, organizational inertia, cooperation distrust, which will have a negative impact on BMI. DC includes digital resource capability (DRC), digital management capability (DMC) and digital collaboration capability (DCC), which promote BMI and play a mediating role between openness and BMI. Enterprise type has a moderating effect on the relationship between DC and BMI.

Research limitations/implications

The results of this paper summarize the opportunities and threats of open innovation, help enterprises fully understand the double-edged sword impact of openness, guide manufacturing enterprises to be sensitive to openness and achieve sustainable innovation. By analyzing the path of DRC, DMC and DCC to BMI, managers can improve their understanding of digital-driven value creation process and improve the competitive advantage of enterprises.

Originality/value

This paper presents the relationships among openness, DC and BMI. We find the non-linear effects of openness on DC and BMI, bridging the inconsistent view of positive or negative relationship between openness and organizational change in previous studies. The introduction of DC extends the theory of dynamic capability in the digital age, and opens the “black box” from opening to BMI from the process perspective of DRC, DMC and DCC. From the perspective of enterprise type, this paper provides different choices of capability upgrading and strategic innovation based on openness for high-tech and non-high-tech manufacturing enterprises.

Details

Journal of Organizational Change Management, vol. 38 no. 1
Type: Research Article
ISSN: 0953-4814

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Article
Publication date: 22 January 2021

Xiaofei Li, Baolong Ma and Hongrui Chu

The value of online reviews has been well documented by academics and practitioners. However, to maximise the benefits of consumer reviews, online sellers must avoid the negative…

1435

Abstract

Purpose

The value of online reviews has been well documented by academics and practitioners. However, to maximise the benefits of consumer reviews, online sellers must avoid the negative consequences associated with customer feedback, such as reputation loss, or product returns after purchase. In developing a better understanding of the relationships between online reviews and their potential for negative impacts, this research aims to explore product returns. Through a quantitative model, this research demonstrates why online reviews can result in product return behaviours.

Design/methodology/approach

The hypotheses were tested via two studies. In Study 1, the authors examine the direct effects of review valence and review volume on product returns by analysing secondary data on 4,995 stores on China's Taobao.com. Study 2 further extends and validates the findings of Study 1 with a survey sample of 795 participants across several online shopping platforms. This analysis examines the mechanics and conditions that influence the relationships between online reviews and product returns through partial least squares-structural equation modelling (PLS-SEM).

Findings

The results show that both review valence (i.e. average star ratings) and the number of reviews can increase the probability of product returns due to the high expectations that result from positive online reviews. Further, the effect of review valence on product returns is stronger for first-time purchasers at a store. In terms of mitigation, the analysis shows that bilateral communications between sellers and buyers can temper the unrealistic expectations set by positive reviews, leading to fewer product returns.

Originality/value

This research adds to the literature on online reviews by exploring the negative consequences of online reviews and the role they play in online purchasing decisions. The findings also provide direct evidence as to why online reviews can result in more product returns, adding clarity to extant research which contains conflicting conclusions as to how online reviews affect product return behaviours.

Details

Asia Pacific Journal of Marketing and Logistics, vol. 33 no. 8
Type: Research Article
ISSN: 1355-5855

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Article
Publication date: 4 August 2023

Zhiqi Liu, Tanghong Liu, Hongrui Gao, Houyu Gu, Yutao Xia and Bin Xu

Constructing porous wind barriers is one of the most effective approaches to increase the running safety of trains on viaducts in crosswinds. This paper aims to further improve…

211

Abstract

Purpose

Constructing porous wind barriers is one of the most effective approaches to increase the running safety of trains on viaducts in crosswinds. This paper aims to further improve the wind-sheltering performance of the porous wind barriers.

Design/methodology/approach

Improved delayed detached eddy simulations based on the k-ω turbulence model were carried out, and the results were validated with wind tunnel tests. The effects of the hole diameter on the flow characteristics and wind-sheltering performance were studied by comparing the wind barriers with the porosity of 21.6% and the hole diameters of 60 mm–360 mm. The flow characteristics above the windward and leeward tracks were analyzed, and the wind-sheltering performance of the wind barriers was assessed using the wind speed reduction coefficients.

Findings

The hole diameters affected the jet behind the wind barriers and the recirculation region above the tracks. Below the top of the wind barriers, the time-averaged velocity first decreased and then increased with the increase in the hole diameter. The wind barrier with the hole diameter of 120 mm had the best wind-sheltering performance for the windward track, but such barrier might lead to overprotection on the leeward track. The wind-sheltering performance of the wind barriers with the hole diameters of 240 mm and 360 mm was significantly degraded, especially above the windward track.

Originality/value

The effects of the hole diameters on the wake and wind-sheltering performance of the wind barriers were studied, by which the theoretical basis is provided for a better design of the porous wind barrier.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 11
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 9 May 2023

Yiming Li, Hongzhuan Chen, Shuo Cheng and Abdul Waheed Siyal

In order to analyze the level of independent controllability and its evolution of high-end equipment manufacturing industry from Jiangsu Province, this article introduces the…

80

Abstract

Purpose

In order to analyze the level of independent controllability and its evolution of high-end equipment manufacturing industry from Jiangsu Province, this article introduces the dual-excitation control line method to construct a comprehensive evaluation model for independent controllability.

Design/methodology/approach

Through the collection of information of high-end equipment manufacturing industry's independent and controllable capabilities on different indicators, the three aspects of advancement, autonomy and controllability, an empirical evaluation of 10 enterprises in the high-end equipment cluster in Jiangsu Province was conducted in terms of advancement, autonomy and controllability.

Findings

It effectively reveals the area and evolution characteristics of the “reward” and “punishment” of different indicators of each representative enterprise and reflects the development status and different characteristics of each representative enterprise on the three indicators. The research results provide decision-making guidance for enterprises in the management and control of advanced manufacturing systems with independent and controllable capabilities.

Originality/value

Existing research focuses on the evaluation of enterprises' independent controllability only on a single angle or index. This paper maps the dynamic evaluation problem of multiple time-point data to the evaluation problem of single time-point multi-index data and investigates the fluctuation of the performance of the same enterprise under different indexes, so as to comprehensively evaluate the independent controllable level of high-end equipment manufacturing industry and analyze the reasons. Further, this paper first establishes an evaluation index system of independent controllable level of high-end equipment manufacturing industry and quantitatively measures the advanced, independent, controllable and other aspects of typical enterprises in this industry by constructing a double incentive control line evaluation model.

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Article
Publication date: 23 August 2019

Ali Hajary, Seyed Ghodratollah Seifossadat, Reza Kianinezhad, Alireza Saffarian and Seyed Saeedollah Mortazavi

This paper aims to present a novel robust control method based on an adaptive PI controller (APIC) to compensate for different disturbances and unknown dynamics for multi-phase…

86

Abstract

Purpose

This paper aims to present a novel robust control method based on an adaptive PI controller (APIC) to compensate for different disturbances and unknown dynamics for multi-phase induction machines.

Design/methodology/approach

The gains of the APIC are adapted online according to the tracking error. Proposed APIC is accompanied with designed linear disturbance observer (LDO) to present robust behavior to machine parameter variations and fault disturbances.

Findings

The results show remarkable dynamic performance in both healthy and faulty conditions when the six-phase induction machine works under APIC and LDO schemes.

Originality/value

The proposed controller need not readjust current controllers for the post-fault condition. The developed Simulink model efficiency is confirmed through experimental tests.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 38 no. 6
Type: Research Article
ISSN: 0332-1649

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