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The purpose of this paper is to improve the mechanical and tribological properties of Si₃N₄ ceramics and to make the application of Si₃N₄ ceramics as tribological materials more extensive.

Si₃N₄-based composite ceramics (SN-2L) containing nitrogen-doped graphene quantum dots (N-GQDs) were prepared by hot press sintering process through adding 2 Wt.% nanolignin as precursor to the Si₃N₄ matrix, and the dry friction and wear behaviors of Si₃N₄-based composite against TC4 disc were performed at the different loads by using pin-on-disc tester.

The friction coefficients and wear rates of SN-2L composite against TC4 were significantly lower than those of the single-phase Si₃N₄ against TC4 at the load range from 15 to 45 N. At higher load of 45 N, SN-2L/TC4 pair presented the lowest friction coefficient of 0.25, and the wear rates of the pins and discs were as low as 1.76 × 10⁻⁶ and 2.59 × 10⁻⁴mm³/N·m. The low friction and wear behavior could be attributed to the detachment of N-GQDs from the ceramic matrix to the worn surface at the load of 30 N or higher, and then an effective lubricating film containing N-GQDs, SiO₂, TiO₂ and Al₂SiO₅ formed in the worn surface. While, at the same test condition, the friction coefficient of the single-phase Si₃N₄ against TC4 was at a range from 0.45 to 0.58. The spalling and cracking morphology formed on the worn surface of single-phase Si3N4, and the wear mechanism was mainly dominated by adhesive and abrasive wear.

Overall, a high-performance green ceramic composite was prepared, and the composite had a good potential for application in engineering tribology fields (such as aerospace bearings).

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0161/

The purpose of this paper is to investigate how a country's national culture and institutional framework influence employees' reactions to changes in organizations and the process of implementation of changes.

The authors conducted interviews with members of top management teams in 160 companies in several large cities in the northern part of China: Beijing, Tianjin, Jinan and Zibo, and in 137 Estonian companies. In both countries, the companies involved represented various industries and sectors, ranging from manufacturing and technology, banking and insurance organizations, to those in energy and education industries. The interviews included open‐ended questions about the process of implementing organizational change and reactions to changes.

Results of interviews with managers indicate the similarities in employees' reactions to changes and in management of change process between the two countries stem from their socialist past. The different approaches to implementing change can be attributed to the differences in democracy and different cultural values.

Future research could involve the employees to provide more insights to the resistance to changes. Other scholars' cultural dimensions could be referred to, such as Trompenaars and Hofstede, in future studies. In order to draw broader conclusions it is necessary to explore alternative explanations and conduct further empirical research in other countries.

The results of this comparison obtained from studying Estonian and Chinese organizations could be useful for foreign investors, managers and owners of companies in two countries in transition: China and Estonia.

Scholars of organizational change have tended to have their focus restricted to the normal socio‐economic context. Studying and comparing organizational changes in transition economies increases knowledge base about change management.

The purpose of this paper is to discover and compare the implementation of crisis management in Chinese and Estonian companies and the strategies the managers have used to prevent or manage crises.

An empirical study was conducted in two economies in transition: China and Estonia, in 2008. Interview data were collected from 102 Chinese companies and 67 Estonian companies. The data were analyzed applying content analysis.

The results indicate that the managers of Chinese and Estonian organizations have identified different crises reflecting the politico‐socio‐economic situation of the countries. The most common type of crises in Chinese organizations is those related to economy, while in Estonian organizations, they are related to human resources. Estonian companies are better prepared for handling crises beforehand than Chinese companies. However, the majority of companies in both countries started reacting after a crisis had already come true. A triangular model of crisis management is presented.

The empirical study is tentative focusing on major differences and similarities in crisis management between two countries in transition. The differences are interpreted from societal‐level development. More in‐depth research in needed based on the results of this study.

The transfer of market‐economy practices often fails due to institutional and cultural tensions and conflict. The study of crisis management in Chinese and Estonian companies tries to increase understanding of the different routes of transition economies and its impact on management and, specifically, on crisis management. The crisis management model based on the study illustrates the interconnection between different elements of crisis management.

The Wiener-Hammerstein nonlinear system is made up of two dynamic linear subsystems in series with a static nonlinear subsystem, and it is widely used in electrical, mechanical, aerospace and other fields. This paper considers the parameter estimation of the Wiener-Hammerstein output error moving average (OEMA) system.

The idea of multi-population and parameter self-adaptive identification is introduced, and a multi-population self-adaptive differential evolution (MPSADE) algorithm is proposed. In order to confirm the feasibility of the above method, the differential evolution (DE), the self-adaptive differential evolution (SADE), the MPSADE and the gradient iterative (GI) algorithms are derived to identify the Wiener-Hammerstein OEMA system, respectively.

From the simulation results, the authors find that the estimation errors under the four algorithms stabilize after 120, 30, 20 and 300 iterations, respectively, and the estimation errors of the four algorithms converge to 5.0%, 3.6%, 2.7% and 7.3%, which show that all four algorithms can identify the Wiener-Hammerstein OEMA system.

Compared with DE, SADE and GI algorithm, the MPSADE algorithm not only has higher parameter estimation accuracy but also has a faster convergence speed. Finally, the input–output relationship of laser welding system is described and identified by the MPSADE algorithm. The simulation results show that the MPSADE algorithm can effectively identify parameters of the laser welding system.

The purpose of this paper is to improve the efficiency of particle optimization method by using direct and indirect surrogate modeling in inverse design problems.

The new algorithm emphasizes the use of a direct and an indirect design prediction based on local surrogate models in particle swarm optimization (PSO) algorithm. Local response surface approximations are constructed by using radial basis neural networks. The principal role of surrogate models is to answer the question of which individuals should be placed into the next swarm. Therefore, the main purpose of surrogate models is to predict new design points instead of estimating the objective function values. To demonstrate its merits, the new approach and six comparative algorithms were applied to two different test cases including surface fitting of a geographical terrain and an inverse design of a wing, the averaged best-individual fitness values of the algorithms were recorded for a fair comparison.

The new algorithm provides more than 60 per cent reduction in the required generations as compared with comparative algorithms.

The comparative study was carried out only for two different test cases. It is possible to extend test cases for different problems.

The proposed algorithm can be applied to different inverse design problems.

The study presents extra ordinary application of double surrogate modeling usage in PSO for inverse design problems.