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Article
Publication date: 11 November 2020

Duncai Lei, Xiannian Kong, Siyu Chen, Jinyuan Tang and Zehua Hu

The purpose of this paper is to investigate the dynamic responses of a spur gear pair with unloaded static transmission error (STE) excitation numerically and experimentally and…

355

Abstract

Purpose

The purpose of this paper is to investigate the dynamic responses of a spur gear pair with unloaded static transmission error (STE) excitation numerically and experimentally and the influences of the system factors including mesh stiffness, error excitation and torque on the dynamic transmission error (DTE).

Design/methodology/approach

A simple lumped parameters dynamic model of a gear pair considering time-varying mesh stiffness, backlash and unloaded STE excitation is developed. The STE is calculated from the measured tooth profile deviation under the unloaded condition. A four-square gear test rig is designed to measure and analyze the DTE and vibration responses of the gear pair. The dynamic responses of the gear transmission are studied numerically and experimentally.

Findings

The predicted numerical DTE matches well with the experimental results. When the real unloaded STE excitation without any approximation is used, the dynamic response is dominated by the mesh frequency and its high order harmonic components, which may not be result caused by the assembling error. The sub-harmonic and super-harmonic resonant behaviors are excited because of the high order harmonic components of STE. It will not certainly prevent the separations of mesh teeth when the gear pair is under the condition of high speed and heavy load.

Originality/value

This study helps to improve the modeling method of the dynamic analysis of spur gear transmission and provide some reference for the understanding of the influence of mesh stiffness, STE excitation and system torque on the vibration behaviors.

Details

Engineering Computations, vol. 38 no. 6
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 19 March 2024

Mingke Gao, Zhenyu Zhang, Jinyuan Zhang, Shihao Tang, Han Zhang and Tao Pang

Because of the various advantages of reinforcement learning (RL) mentioned above, this study uses RL to train unmanned aerial vehicles to perform two tasks: target search and…

59

Abstract

Purpose

Because of the various advantages of reinforcement learning (RL) mentioned above, this study uses RL to train unmanned aerial vehicles to perform two tasks: target search and cooperative obstacle avoidance.

Design/methodology/approach

This study draws inspiration from the recurrent state-space model and recurrent models (RPM) to propose a simpler yet highly effective model called the unmanned aerial vehicles prediction model (UAVPM). The main objective is to assist in training the UAV representation model with a recurrent neural network, using the soft actor-critic algorithm.

Findings

This study proposes a generalized actor-critic framework consisting of three modules: representation, policy and value. This architecture serves as the foundation for training UAVPM. This study proposes the UAVPM, which is designed to aid in training the recurrent representation using the transition model, reward recovery model and observation recovery model. Unlike traditional approaches reliant solely on reward signals, RPM incorporates temporal information. In addition, it allows the inclusion of extra knowledge or information from virtual training environments. This study designs UAV target search and UAV cooperative obstacle avoidance tasks. The algorithm outperforms baselines in these two environments.

Originality/value

It is important to note that UAVPM does not play a role in the inference phase. This means that the representation model and policy remain independent of UAVPM. Consequently, this study can introduce additional “cheating” information from virtual training environments to guide the UAV representation without concerns about its real-world existence. By leveraging historical information more effectively, this study enhances UAVs’ decision-making abilities, thus improving the performance of both tasks at hand.

Details

International Journal of Web Information Systems, vol. 20 no. 3
Type: Research Article
ISSN: 1744-0084

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Article
Publication date: 16 June 2020

Jinyuan Ma, Kejin Zhu, Yi Cao, Qiongqiong Chen and Xuesen Cheng

This paper examines the correlation between university discipline and industrial structure in the context of the integration and development of the Guangdong-Hong Kong-Macau…

500

Abstract

Purpose

This paper examines the correlation between university discipline and industrial structure in the context of the integration and development of the Guangdong-Hong Kong-Macau Greater Bay Area (hereinafter the Greater Bay Area). It aims to determine the industrial structure deviation, and further identify human resource shortages and complementarity through the lens of the university discipline layout in the three regions of the Greater Bay Area, namely, the nine mainland Guangdong cities in the Pearl River Delta, Hong Kong, and Macau.

Design/methodology/approach

The paper takes a quantitative Pearson correlation approach to determine the magnitude and strength of the relationship between regional university discipline and industrial structure in the Greater Bay Area, using predictor variables of percentage of compositions of GDP by sector to manifest the industrial structure and criterion variables of percentage of compositions of university enrollments by an academic program to represent the university discipline layout.

Findings

The most significant empirical result suggests that industrial structure deviation exists in the secondary industries of both Guangdong and Hong Kong. This indicates the complementarity between regions of the Greater Bay Area: the number of science and engineering talents graduating from the universities in Hong Kong exceeds the demands of Hong Kong’s local needs, while the science and engineering talents cultivated by universities in Guangdong cannot satisfy the needs of its secondary industries. However, the cities of Guangdong are not the primary choice of most Hong Kong graduates (Zhaopin, 2019).

Originality/value

There have been previous empirical studies dealing with the correlation between Chinese higher education discipline layout and industrial structure at the national level. There have been more case analyses at the provincial level, and some studies have used a comparative lens to find implications for the Chinese transformation. However, few studies have examined the correlation between higher education discipline layout and industrial structure in the context of the Greater Bay Area, with its emphasis on regional synergy and the distinction of “one country, two systems, and three tariff zones.” Based on its empirical findings, this study calls for a talent ecosystem that is beneficial for talent flow, talent sharing, and talent cultivation in a complementary manner.

Details

Asian Education and Development Studies, vol. 11 no. 1
Type: Research Article
ISSN: 2046-3162

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Article
Publication date: 5 July 2021

Ruilin Zhu and Jinyuan Zhang

Grappling with the sweeping pandemic, the small hospitality business (SHB), smaller in scale and weaker in risk mitigation, has been seriously affected. The purpose of this study…

839

Abstract

Purpose

Grappling with the sweeping pandemic, the small hospitality business (SHB), smaller in scale and weaker in risk mitigation, has been seriously affected. The purpose of this study aims to supplement the unrepresented area of SHB in China from the digital perspective by drawing on instrumentalization theory (IT).

Design/methodology/approach

Based on two appropriate and detailed SHB cases, this paper adopted a qualitative approach to understand and conceptualize the focal issue.

Findings

This study identified the factors affecting SHB at operational, managerial and transformational levels amidst the crisis. It further developed a theoretical framework of the SHB rebound matrix, highlighting the importance of digitization and digitalization.

Research limitations/implications

The research theoretically confirmed that SHB is internally, externally and essentially restricted and developed a corresponding rebound matrix. It practically supports SHB’s transformation by making recommendations to unleash the potential of digital business.

Originality/value

This study complements extant descriptive and atheoretical research by focusing on SHB’s underlying digital nature through the lens of IT, providing an evidenced theoretical understanding of SHB’s development amidst and after the pandemic.

Details

International Journal of Contemporary Hospitality Management, vol. 33 no. 8
Type: Research Article
ISSN: 0959-6119

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Article
Publication date: 13 October 2022

Xiaomeng Zhang, Sang Xiong, Feng Gao, Jinyuan Du and Qin-Jian Du

WO3 particles were prepared by the sol-gel method. Tetraethyl silicate (TEOS) was used to obtain a SiO2-coated WO3 nanoparticle. Quantum chemical parameters of oleic acid…

160

Abstract

Purpose

WO3 particles were prepared by the sol-gel method. Tetraethyl silicate (TEOS) was used to obtain a SiO2-coated WO3 nanoparticle. Quantum chemical parameters of oleic acid, triethanolamine, glycerol and methyl pentane as dispersants were theoretically calculated. Tribological properties of SiO2/WO3 nanocomposite lubricant were carried out on an MRS-10A four-ball friction and wear tester.

Design/methodology/approach

The purpose of this study is to investigate the preparation and tribological properties of SiO2/WO3 nanocomposite lubricant.

Findings

The obtained SiO2-coated WO3 nanoparticle (nano-SiO2/WO3) with a particle size of about 70 nm. The calculated adsorption energy of triethanolamine on the surface of the steel ball is 554.6 eV, and triethanolamine is selected as the dispersant. The dispersion effect of SiO2/WO3 nanocomposite lubricant is good, which shows that triethanolamine oleate plays a good dispersion role in the preparation of lubricant, which is consistent with the calculation results of the adsorption capacity of dispersant. As a good auxiliary lubricant, SiO2 can improve the tribological properties and wear resistance of WO3.

Originality/value

Nanocomposite lubricants have been the focus of research in recent years, which could greatly reduce energy consumption. And the SiO2/WO3 exhibited excellent lubrication performance as a lubricant additive. The lubrication mechanism of SiO2/WO3 nanocomposite lubricant is the synergistic lubrication mechanism of friction film lubrication and antifriction bearing. This study could provide a certain reference for the practical application of nanocomposite lubricants.

Details

Industrial Lubrication and Tribology, vol. 75 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

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