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Passivity theory is closely related to both electrical network and circuit analysis methods. The purpose of this paper is to try to establish some basic results on the uncertain discrete‐time fuzzy systems.

Applying the classical and effective Lyapunov function method and the powerful linear matrix inequality toolbox in MATLAB, the paper provides some sufficient conditions to verify the passivity of the uncertain discrete‐time fuzzy systems, or to passify such a system.

For uncertain discrete‐time fuzzy systems, its passivity can be easily verified numerically, and its passification can also be fulfilled.

A very effective and convenient criterion is provided to test the passivity of practical nonlinear discrete‐time system or to passify it.

This paper first treats this topic on uncertain discrete‐time fuzzy systems and obtains some important results.

Previous research has yielded inconsistent findings of the effects that task conflict has on creative outcomes, with some research finding a negative relationship but others holding a positive or even no significant relationship. Drawing on the too-much-of-a-good-thing effect approach, this paper aims to investigate the curvilinear relations between task conflict and creative idea generation as well as the mediating role of task reflexivity and the moderating role of task complexity.

Two studies were carried out to test the proposed relationship. In Study 1, multisource and lagged data collected from 533 employees and 140 corresponding supervisors were used to test the curvilinear relationship between task conflict and creative idea generation as well as the moderating effect of task complexity. In Study 2, the authors extended the findings by exploring the mediating effect of task reflexivity using a matched sample of 350 employees and 99 corresponding supervisors.

Task conflict had an inverted U-shaped relationship with creative idea generation, and task reflexivity partially mediated this relationship. Besides, this association was moderated by task complexity such that the curvilinear relationship was more pronounced for tasks with lower complexity.

This study was more or less contaminated by common method variance because some variables were derived from the same sources. Also, task conflict might be necessitated to differentiate and more situational variables should be considered to draw a complete picture.

Managers should undertake conflict management according to the levels of task conflict and task complexity. At a lower degree of task conflict, managers might motivate employees to think more about task-related issues; at higher levels of task conflict, managers should act as conflict mediators to reduce the underlying negative effects, especially for simple tasks.

These findings could help us understand the boundary conditions under, and the underlying mechanisms by, which task conflict has an impact on creative idea generation.

This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.

Vibration fatigue of railway bogie arising from the wheel/rail high frequency vibration has become the main concern of railway operators. Previous reviews usually focused on the formation mechanism of wheel/rail high frequency vibration. This paper thus gives a critical review of the vibration fatigue of railway bogie owing to the short-pitch irregularities-induced high frequency vibration, including a brief introduction of short-pitch irregularities, associated high frequency vibration in railway bogie, typical vibration fatigue failure cases of railway bogie and methodologies used for the assessment of vibration fatigue and research gaps.

The results showed that the resulting excitation frequencies of short-pitch irregularity vary substantially due to different track types and formation mechanisms. The axle box-mounted components are much more vulnerable to vibration fatigue compared with other components. The wheel polygonal wear and rail corrugation-induced high frequency vibration is the main driving force of fatigue failure, and the fatigue crack usually initiates from the defect of the weld seam. Vibration spectrum for attachments of railway bogie defined in the standard underestimates the vibration level arising from the short-pitch irregularities. The current investigations on vibration fatigue mainly focus on the methods to improve the accuracy of fatigue damage assessment, and a systematical design method for vibration fatigue remains a huge gap to improve the survival probability when the rail vehicle is subjected to vibration fatigue.

The research can facilitate the development of a new methodology to improve the fatigue life of railway vehicles when subjected to wheel/rail high frequency vibration.

This paper aims to study the corrosion inhibition behavior of imidazopyridine and its three derivatives on brass.

The authors performed weight loss experiments, electrochemical experiments including the polarization curve and electrochemical impedance spectrum, corrosion morphology observation using scanning electron microscope (SEM) and atomic force microscope (AFM) and surface composition analysis via X-ray photoelectron spectroscopy (XPS) to analyze the corrosion inhibition behavior of imidazopyridine and its three derivatives on brass by using quantum chemical calculation (Gaussian 09), molecular dynamics simulation (M-S) and Langmuir adsorption isotherm.

According to the results, imidazole-pyridine and its derivatives were found to be modest or moderately mixed corrosion inhibitors; moreover, they were spontaneously adsorbed on the metal surface in a single-layer, mixed adsorption mode.

The corrosion inhibition properties of pyrazolo-[1,2-a]pyridine and its derivatives on brass in sulfuric acid solution were analyzed through weight loss and electrochemical experiments. Moreover, SEM and AFM were simultaneously used to observe the corrosion appearance. Furthermore, XPS was used to analyze the surface. Then, Gaussian 09 and M-S were combined along with the Langmuir adsorption isotherm to investigate the corrosion inhibition mechanism of imidazole-[1,2-a]pyridine and its derivatives.

This paper provides a summary of the issues in the passive fire protection of steel structures. Types of passive fire protection and the material properties of protection members and steel members are described. The paper deals with the possibility of partial fire protection for secondary steel beams, in cases where, due to possible membrane action, it is not necessary to apply passive protection to the entire beams.

Studies of partially fire-protected steel structures are compared, and results from studies with different input data are summarized. A fire experiment was conducted to investigate the effect of partial passive protection in a small-scale furnace. Based on the findings of the experiment, numerical models were prepared using Ansys Mechanical.

The results are summarized, and a partial fire protection length of 500 mm is recommended. Various partial fire protection lengths were compared, and the temperature development of the steel contactors was compared using a protection length of 500 mm. At the end of the paper, options for partial passive protection of steel beams are presented.

Extended paper from ASFE2021 based on selection.