Chunxiao Jiao, Jianghai Xu, Donglin Zou, Na Ta and Zhushi Rao
The purpose of this paper is to study the flow field characteristics of the micro-scale textured bearing surfaces using the lattice Boltzmann method based on the microscopic…
Abstract
Purpose
The purpose of this paper is to study the flow field characteristics of the micro-scale textured bearing surfaces using the lattice Boltzmann method based on the microscopic dynamics of the fluid.
Design/methodology/approach
Considering the inertia effects and the micro-scale effects, the models of a single micro-scale texture unit cell with different shapes and different film thickness ratios are established. The influence of pressure difference between inlet and outlet of the unit cell on flow characteristics is studied.
Findings
The surface pressure distribution, flow patterns and pressure contours in the flow field are obtained. The results reveal that the pressure difference has a significant influence on the characteristics of the micro-textured flow field.
Originality/value
The results have certain guiding significance for further step investigation on microscopic lubrication mechanism of the water-lubricated polymer bearings.
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Jun He, Minzhou Luo, Xinglong Zhang, Marco Ceccarelli, Jian Fang and Jianghai Zhao
This paper aims to present an adaptive fuzzy sliding mode controller with nonlinear observer (AFSMCO) for the redundant robotic manipulator handling a varying payload to achieve a…
Abstract
Purpose
This paper aims to present an adaptive fuzzy sliding mode controller with nonlinear observer (AFSMCO) for the redundant robotic manipulator handling a varying payload to achieve a precise trajectory tracking in the task space. This approach could be applied to solve the problems caused by the dynamic effect of the varying payload to robotic system caused by model uncertainties.
Design/methodology/approach
First, a suitable observer using the recursive algorithm is presented for an accurate estimation of external disturbances caused by a variable payload. Second, the adaptive fuzzy logic is designed to approximate the parameters of the sliding mode controller combined with nonlinear observer (SMCO) to avoid chattering in real time. Moreover, Lyapunov theory is applied to guarantee the stability of the proposed closed-loop robotic system. Finally, the effectiveness of the proposed control approach and theoretical discussion are proved by simulation results on a seven-link robot and demonstrated by a humanoid robot platform.
Findings
The varying payload leads to large variations in the dynamics of the manipulator and the tracking error. To achieve high-precision position tracking, nonlinear observer was introduced to feed into the sliding mode control (SMC) which had improved the ability to resist the external disturbance. In addition, the chattering caused by the SMC was eliminated by recursively approximating the switching gain with the usage of adaptive fuzzy logic. Therefore, a distributed control strategy solves the problems of an SMC implementation in improving its tracking performance and eliminating the chattering of the system control.
Originality/value
The AFSMCO is proposed for the first time and used to control the redundant robotic manipulator that handles the varying payload. The proposed control algorithm possesses better robustness and higher precision for the trajectory tracking than classical SMC.
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Li Fu, Lingling Wang and Jianghai Hu
The aim of this paper is to propose a new coning correction algorithm, based on the singular perturbation technique, for the attitude update computation with non‐ideal angular…
Abstract
Purpose
The aim of this paper is to propose a new coning correction algorithm, based on the singular perturbation technique, for the attitude update computation with non‐ideal angular rate information.
Design/methodology/approach
Unlike conventional coning correction algorithms, the new method uses angular rate two‐time scale model to construct the coning correction term of attitude update. In order to achieve balanced real/pseudo coning correction performance, the selection guidelines of the new algorithm parameters are established.
Findings
Performance of the new algorithm is evaluated by comparison with the conventional algorithm in no ideal sensors undergoing stochastic coning environments. The accuracy of attitude update can be improved effectively with reduced computational workload by using this new coning algorithm as compared with conventional ones.
Practical implications
The proposed coning correction algorithm can be implemented with angular rate sensors in UAV (unmanned aerial vehicle) and other aircrafts attitude estimation for navigation and control applications.
Originality/value
Singular perturbation is an effective method for structuring coning correction algorithm with filtered angular rate outputs in stochastic coning environments. The improved coning correction algorithm based on singular perturbations reduces the real and pseudo coning effects effectively as compared with conventional ones. It is proved to be valid for improvement of accuracy with reduced computations of the attitude update.
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Yuhai Shen, Yanshuang Wang, Jianghai Lin, Pu Zhang, Xudong Gao and Zijun Wang
This paper aims to determine a suitable anti-wear and friction-reducing compounding additive for lithium greases (LG) by investigating the effects of three single additives…
Abstract
Purpose
This paper aims to determine a suitable anti-wear and friction-reducing compounding additive for lithium greases (LG) by investigating the effects of three single additives potassium borate (PB), zinc dialkyl dithiophosphate and molybdenum dialkyl dithiophosphate (MoDDP) and two compound additives on the friction, wear and extreme pressure properties of LG.
Design/methodology/approach
The effects of the above five additives on the friction, wear and extreme pressure properties of LG were investigated using an SRV-5 friction tester. An X-ray photoelectron spectrometer was used to analyze the various elements presented on the wear surface as well as the types of compounds.
Findings
The compound additive suitable for grease consists of PB and MoDDP, which have excellent friction reduction, anti-wear and extreme pressure properties. And a boundary protection film consisting of oxide and MoS2 is formed on the friction surface, thus improving the friction reduction and anti-wear performance of the grease.
Originality/value
This study can improve the anti-wear and friction-reduction performance of greases, which is of great importance in the field of industrial lubrication. The results of this paper are expected to be useful to researchers and academics of grease.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2022-0350/
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Sheng Xu, Qingde Yue and Binbin Lu
The implementation of the innovation-driven development strategy is of practical significance for improving the quality and efficiency of economic growth and accelerating the…
Abstract
Purpose
The implementation of the innovation-driven development strategy is of practical significance for improving the quality and efficiency of economic growth and accelerating the transformation of economic development mode. The purpose of this paper is to study the impact of innovation-driven strategies on marine industry agglomeration and industrial transformation.
Design/methodology/approach
In traditional grey correlation analysis, when the positive and negative areas cancel each other out during the integration process, the calculation result of the correlation degree is often inconsistent with the qualitative analysis. For this reason, from the perspective of curve similarity, this paper constructs two response curves through the relative change area of the two curves and the relative area change ratio of similar degree, thus constructing an improved grey relational model.
Findings
The authors find that the innovation investment has a better correlation with marine industrial agglomeration. It also found that Guangdong Province has the highest degree of correlation between innovation indicators and marine industrial agglomeration. Much beyond the authors’ expectation, in the areas where marine industrial agglomeration is high, the synergistic effect is not obvious by using the location entropy method.
Originality/value
The improved grey correlation analysis method can effectively overcome the phenomenon that the positive and negative areas cancel each other in the integration process of the original algorithm, and it can also effectively measure the negative correlation between variables. This paper explores the impact of innovation drive on the agglomeration of marine industries, which is of great significance to the sustainable development of marine economy.
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This paper aims to fill the academic gaps in the study of the new co‐operative movement in China and its innovative mechanisms, and to assess why new co‐operatives deviate from…
Abstract
Purpose
This paper aims to fill the academic gaps in the study of the new co‐operative movement in China and its innovative mechanisms, and to assess why new co‐operatives deviate from the orthodox co‐operative model represented by the standards of the International Cooperative Alliance (ICA).
Design/methodology/approach
As an alternative to the popular ideal‐co‐operative perspective, the paper employs a historical approach to understand the co‐operative renaissance in China. Afterwards, the paper presents an application as well as an example to reinforce this understanding and to demonstrate the validity of the analysis.
Findings
Using this approach, this paper demonstrates the formation process of real‐type co‐operatives under the influence of institutional legacies as well as resources and environments. Moreover, The shareholding co‐operatives have been developed as new co‐operative forms. They are characterized by their multiple stakeholdership, their multi‐purpose operations, and their orientation to the whole community.
Originality/value
The paper looks for the logic of the dynamics and evolution of the newly emerged co‐operatives, trying to explain their non‐compliance with the ICA standards. It analyses the bottom‐up institutional innovation process and the key role played by co‐operative entrepreneurs. Moreover, it contributes to understanding their hybrid form as a nexus of tensions. Therefore, it helps to explain some of the conceptual and practical difficulties that hamper the understanding of new co‐operative development in China.
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The purpose of this paper is to test whether the policies of China’s financial restraint have an inhibitory effect on the consumption of residents.
Abstract
Purpose
The purpose of this paper is to test whether the policies of China’s financial restraint have an inhibitory effect on the consumption of residents.
Design/methodology/approach
This study used the principal component analysis for constructing a financial restraint index and also used empirical methodology.
Findings
The authors found that financial restraint policies create rent opportunities for banking sector and production sector, which further creates the rent opportunities for the household sector. Such transfer of rent and redistribution will have an inhibitory effect on residents’ consumption. The financial restraint policies directly and indirectly inhibit the growth of residents’ income; and in theory, the purpose of financial restraint policy is to promote economic growth, thus promoting residents’ consumption. Thus, the financial restraint policies impacting the residents’ consumption are non-linear and test the threshold effect of financial restraints on the residents’ consumption of China.
Research limitations/implications
This paper’s theoretical contribution includes: increasing the connotation of financial restraint in the policies of stock market and foreign exchange controls, and further developing the financial restraint theory; and exploring the inhibitory effect on the consumption of residents from the perspective of financial restraints to enrich the connotation of the consumption theory.
Originality/value
The findings in this study can help the financial authorities to gradually relax the financial restraint policies to encourage residents’ consumption.
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Jiehong Zhou, Yu Jin, Yu Wang and Qiao Liang
Food markets are characterized by asymmetric information between suppliers and consumers, which causes inefficiency of market and food safety risks. This paper studies how the…
Abstract
Purpose
Food markets are characterized by asymmetric information between suppliers and consumers, which causes inefficiency of market and food safety risks. This paper studies how the food quality and safety information disclosed by the government affects the hazard analysis and critical control point (HACCP) certification decision of meat producers. The heterogeneity of the effects across different regions, provinces with different meat output scales and provinces with different intensities of food safety regulation is evaluated.
Design/methodology/approach
This paper applies a unique database comprising information from multiple sources. Food quality and safety information disclosure is indicated by the number of failure records of food sampling inspections by the government in 2015–2018. Fixed-effect model is used in the analyses.
Findings
The results demonstrate that food quality and safety information disclosure has a significant effect on the HACCP certification adoption by meat producers. The effect is heterogeneous across geographic regions, i.e. this effect is larger in the east and the middle of China than that in the west and the northeast. The heterogeneity across regions may be caused by the variance in meat output scales and fiscal expenditures on food safety among provinces.
Originality/value
This research is one of the preliminary attempts to understand how producers respond in terms of HACCP certification to the amount of food quality and safety information disclosed by the government, based on the case of meat industry in China.
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Xin Feng, Yimeng Zhao, Linan Zhang and Xueli Zhang
The rapid development of information technology, epitomized by AIGC and the metaverse, presents unprecedented challenges to techno-ethics, exposing society to significant risks…
Abstract
Purpose
The rapid development of information technology, epitomized by AIGC and the metaverse, presents unprecedented challenges to techno-ethics, exposing society to significant risks and uncertainties. A systematic investigation and discussion of the construction of techno-ethical order become crucial under the paradigm of risk society theory. The selection of conditions and pathways for constructing a techno-ethical order under the risk society theory paradigm becomes an unavoidable and vital issue.
Design/methodology/approach
Drawing on risk society theory, this study employs scientometrics and qualitative comparative analysis (QCA) to empirically analyze the key factors and conditional pathways in the construction of techno-ethical order. Initially, a quantitative analysis is conducted on 1,490 thematic literature retrieved from CNKI and WoS to identify the hot topics and core concepts in techno-ethical research. Subsequently, QCA configuration analysis is applied to calculate eight evaluation indicators and their weights from the perspectives of government, society and individuals. Finally, the study explores the mechanisms of the impact of these indicators’ weights on the construction of techno-ethical order.
Findings
The analysis of factor weights and pathways indicates that the selection of pathways for constructing techno-ethical order is influenced both by the inherent development patterns of technology and societal systems and cultural values. Literature metrics analysis reveals an overall trend of sustained growth in techno-ethical research, indicating an unprecedented prosperity in this field. Alongside technological advancements, keywords related to “artificial intelligence” play a crucial role in current techno-ethical research. Configuration analysis demonstrates that conditional variables from the dimensions of government, society and individuals form a configuration pathway, influencing and synergistically impacting the overall level of techno-ethical order construction. Attention should be given to the mutual constraints and synergistic effects of factors related to technological development, societal systems and cultural values.
Originality/value
This study, grounded in the risk society theory paradigm, quantitatively explores the key factors and pathways of techno-ethical order construction in academic texts, expanding new perspectives, providing novel insights, establishing innovative methodologies and extending new boundaries in the field. Further enrichment of the dataset and in-depth discussions are warranted for continued advancement.
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Philanthropy is taken as a strategic behavior by private enterprises to obtain financial resources from governments. This paper aims to examine the relationship between private…
Abstract
Purpose
Philanthropy is taken as a strategic behavior by private enterprises to obtain financial resources from governments. This paper aims to examine the relationship between private enterprise philanthropy and the debt finance, further investigating the way by which governments exchange resources with private enterprises.
Design/methodology/approach
The paper opted for an empirical study using a sample of 1,489 Chinese private-listed companies from 2007 to 2010. The study analyzed the relationship between philanthropy and debt finance based on the resource dependence theory and social exchange theory and tested the moderating effect of political connection.
Findings
Philanthropy can help private enterprises to get the debt finance, and this effect occurs mainly among the political connected private enterprises; the higher degree of credit allocation marketization is, the less philanthropy can affect the debt finance and the less influence political connection can exert on that relationship. Philanthropy contributes to debt financing mainly because it can help obtain more long-term loan, and this effect is more obvious for politically connected private enterprises in regulated industries.
Originality/value
This paper verifies the action logic of private enterprises philanthropy from the perspective of exchange behavior, which is helpful to understand the motive and influence of private enterprises philanthropy.