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This paper aims to study the issues of adaptive fuzzy control for a category of switched under-actuated systems with input nonlinearities and external disturbances.

A control scheme based on sliding mode surface with a hierarchical structure is introduced to enhance the responsiveness and robustness of the studied systems. An equivalent control and switching control rules are co-designed in a hierarchical sliding mode control (HSMC) framework to ensure that the system state reaches a given sliding surface and remains sliding on the surface, finally stabilizing at the equilibrium point. Besides, the input nonlinearities consist of non-symmetric saturation and dead-zone, which are estimated by an unknown bounded function and a known affine function.

Based on fuzzy logic systems and the hierarchical sliding mode control method, an adaptive fuzzy control method for uncertain switched under-actuated systems is put forward.

The “cause and effect” problems often existing in conventional backstepping designs can be prevented. Furthermore, the presented adaptive laws can eliminate the influence of external disturbances and approximation errors. Besides, in contrast to arbitrary switching strategies, the authors consider a switching rule with average dwell time, which resolves control problems that cannot be resolved with arbitrary switching signals and reduces conservatism.

Employing the anti-corruption campaign as an exogenous political shock, this paper examines how political intervention shapes the impact of financial expert CEOs on firm investment decisions.

This paper uses a sample of 2,808 Chinese firms listed in the Shanghai and Shenzhen Stock Exchanges from 2003 to 2016. Panel data is used for conducting the analysis controlling for firm, industry, and year fixed effects.

The authors found that CEOs with financial expertise are sensitive to political intervention when making investment decisions. First, financial expert CEOs spend more on R&D expenditure in private-owned companies and they are associated with less R&D expenditure in state-owned enterprises (SOEs). Second, financial expert CEOs are associated with higher investment expenditure in general, but they become less likely to invest more in the post-anti-corruption period. The reduction in investment expenditure due to the anti-corruption campaign is more pronounced in SOEs than in private-owned companies. Third, the anti-corruption campaign promotes R&D investment in general, but in SOEs, expert CEOs tend to be less likely to invest more on R&D after the anti-corruption shock.

This paper enriches the growing literature on the impact of political intervention and the role of the anti-corruption campaign on corporate behaviour.

The purpose of this study is to develop a protective coating system on mild steel panel incorporating epoxidized natural rubber with acrylic polyol resin.

In this work, a novel attempt is made to develop binder coatings using epoxidized natural rubber-based material and an organic resin (acrylic resin) for corrosion protection on metal substrate. Seven different samples of multifunctional coatings are developed by varying the compositions of epoxidized natural rubber (ENR) and acrylic resin. The properties of the developed coatings have been characterized using analytical methods such as Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). EIS has been carried out for 30 days to evaluate the corrosion resistance after immersing into 3.5 wt.% of sodium chloride. Cross hatch cut tester (CHT) has been used to study the adhesive properties. UV–Visible Spectroscopy (UV–Vis) was also used to assess changes in the coating-film transparency of the natural rubber-based coating systems in this study.

The developed coatings have formed uniform layer on the substrate. CHT results show excellent adhesion of the coatings. Higher concentrations of ENR have higher transparency level, which reduces when the acrylic concentration increases. FTIR analysis confirms the crosslinking that occurred between the components of the coatings. Based on the impedance data from EIS, the incorporation of natural rubber can be an additive for the corrosion protection, which has the coating resistance values well above 108Ω even after 30 days of immersion.

The blending method provides a simple and practical solution to improve the strength and adhesion properties of acrylic polyol resin with epoxidized natural rubber. There is still improvement needed for long-term applications.

The work has been conducted in our laboratory. The combination of natural rubber-based materials and organic resins is a new approach in coating research.

To assist firefighters in extinguishing fires more safely and efficiently, this paper aims to present an eversion-growing firefighting robot that overcomes the maneuverability constraints of existing firefighting robots, which hinder their ability to approach fire sources effectively.

The robot uses an everting tube as the body, with the cavity formed during eversion to deliver water to the tip. The loading capacity models are extended by considering the mechanical reinforcement provided by the contact between the everting tube and obstacles. Then the authors design a steering mechanism based on the Yoshimura-ori structure to ensure the robot’s steering capabilities. Furthermore, the authors present a new tip mount for the eversion-growing robot in fire conditions.

Experiments demonstrate the robot’s ability to navigate obstacles effectively using the Yoshimura-ori steering mechanism and perform firefighting tasks successfully.

The robot innovatively overcomes traditional firefighting limitations and integrates the eversion-growing structure with the Yoshimura-ori steering mechanism, demonstrating effective obstacle-traversing capabilities in performing tasks.

Existing robot-assisted minimally invasive surgery (RMIS) system lacks of force feedback, and it cannot provide the surgeon with interaction forces between the surgical instruments and patient’s tissues. This paper aims to restore force sensation for the RMIS system and evaluate effect of force sensing in a master-slave manner.

This paper presents a four-DOF surgical instrument with modular joints and six-axis force sensing capability and proposes an incremental position mode master–slave control strategy based on separated position and orientation to reflect motion of the end of master manipulator to the end of surgical instrument. Ex-vivo experiments including tissue palpation and blunt dissection are conducted to verify the effect of force sensing for the surgical instrument. An experiment of trajectory tracking is carried out to test precision of the control strategy.

Results of trajectory tracking experiment show that this control strategy can precisely reflect the hand motion of the operator, and the results of the ex-vivo experiments including tissue palpation and blunt dissection illustrate that this surgical instrument can measure the six-axis interaction forces successfully for the RMIS.

This paper addresses the important role of force sensing and force feedback in RMIS, clarifies the feasibility to apply this instrument prototype in RMIS for force sensing and provides technical support of force feedback for further clinical application.

This study aims to establish the linkage among export tax rebate (ETR), firm innovation and product quality of Chinese agricultural product processing industry (APPI), so that more targeted policy implications can be discussed.

Using highly disaggregated firm-product-destination-level data through 2001 to 2013 of Chinese APPI, this study employs a two-way fixed effects specification to establish the linkage between ETR and product quality, while the mediational model is adopted to examine potential mechanisms.

Baseline estimates show that a 1% increase in ETR rate leads to a significant increase in the product quality of APPI by 0.12% on the whole. However, there is a nonlinear, inverse-U shaped relationship between ETR and product quality, and the optimal inflection point occurs when ERT rate equals 0.15. Mechanism analyses show that firm innovation is an important impact channel, which explains 9.8% of quality improvement induced by raising ETR. Further heterogeneous analyses reveal both the total effects of ETR on product quality and the mediation effects of innovation are dominated by young SMEs (small and medium-size enterprises).

Authorities can promote the innovation and then product quality improvement of young SMEs by moderately increasing ETR rate. To ensure ETR more effective in improving quality, it is necessary for the government to encourage innovation. Authorities can reduce the risk of innovation failure for low-tech firms by increasing R&D subsidies, while ensuring innovation returns for high-tech firms in combination with stronger intellectual property protection.

First, this is one of the earlier studies to explore the relationship between ETR and product quality specifically for Chinese APPI. Second, we show firm innovation as an important mediator so that policies aim at raising ETR rates are eventually beneficial to product quality. Third, using the highly disaggregated data, we allow ETR rate to vary across different products, which is an improvement in the accuracy of previous literature. Finally, our research provides additional empirical evidence for revealing the micro-mechanism of ETR affecting firm behaviors.

By studying the green development efficiency (GDE) of 33 cities in the provinces of Jiangsu, Zhejiang, and Fujian in China, this study strives to conduct an analysis of the sustainable practices implemented in these developed regions, and derive valuable insights that can foster the promotion of green transformation.

First, the urban green development system (GDS) was decomposed into the economic benefit subsystem (EBS), social benefit subsystem (SBS), and pollution control subsystem (PCS). Then, a mixed network SBM model was proposed to evaluate the GDE during 20152020, with Moran’s I and Bootstrap truncated regression model subsequently applied to measure the spatial characteristics and driving factors of efficiency.

Subsystem efficiency presents a distribution trend of PCS > EBS > SBS. There is a particular spatial aggregation effect in EBS efficiency, whereas SBS and PCS efficiencies have no significant spatial autocorrelation. Furthermore, urbanization level contributes significantly to the efficiency of all subsystems; industrial structure, energy consumption, and technological innovation play a crucial role in EBS and SBS; external openness is a pivotal factor in SBS; and environmental regulation has a significant effect on PCS.

This study further decomposes the black box of GDS into subsystems including the economy, society, and environment. Additionally, by employing a mixed network SBM model and Bootstrap truncated regression model to investigate efficiency and its driving factors from the subsystem perspective, it endeavors to derive more detailed research conclusions and policy implications.

The purpose of this paper is to solve the problem that mobile robots are still based on reactive collision avoidance in unknown dynamic environments leading to a lack of interaction with obstacles and limiting the comprehensive performance of mobile robots. A dynamic window approach with multiple interaction strategies (DWA-MIS) is proposed to solve this problem.

The algorithm firstly classifies the moving obstacle movement intention, based on which a rule function is designed to incorporate positive incentives to motivate the robot to make correct avoidance actions. Then, the evaluation mechanism is improved by considering the time cost and future information of the environment to increase the motion states. Finally, the optimal objective function is designed based on genetic algorithm to adapt to different environments with time-varying multiparameter optimization.

Faced with obstacles in different states, the mobile robot can choose a suitable interaction strategy, which solves the limitations of the original DWA evaluation function and avoids the defects of reactive collision avoidance. Simulation results show that the algorithm can efficiently adapt to unknown dynamic environments, has less path length and iterations and has a high comprehensive performance.

A DWA-MIS is proposed, which increases the interaction capability between mobile robots and obstacles by improving the evaluation function mechanism and broadens the navigation strategy of DWA at a lower computational cost. After real machine verification, the algorithm has a high comprehensive performance based on real environment and provides a new idea for local path planning methods.

With the rapid low-carbon transformation in China, the industrial approach and labor structure of mining enterprises are undergoing constant changes, leading to an increasing psychological dilemma faced by coal miners. This study aims to reveal the relationship and mechanism of factors influencing the psychological dilemma of miners, and to provide optimal intervention strategies for the safety and sustainable development of employees and enterprises.

To effectively address the complex issue of the psychological dilemma faced by miners, this study identifies and constructs five-dimensional elements, comprising 20 indicators, that influence psychological dilemmas. The relational mechanism of action of factors influencing psychological dilemma was then elucidated using an integration of interpretive structural modeling and cross-impact matrix multiplication.

Industry dilemma perception is a “direct” factor with dependent attributes. The perceptions of management response and relationship dilemmas are “root” factors with driving attributes. Change adaptation dilemma perception is a “susceptibility” factor with linkage attributes. Work dilemma perception is a “blunt” factor with both dependent and autonomous attributes.

The aforementioned findings offer a critical theoretical and practical foundation for developing systematic and cascading intervention strategies to address the psychological dilemma mining enterprises face, which contributes to advancing a high-quality coal industry and efficient energy development.