Zhiqiang Zhang, Xingyu Zhu and Ronghua Wei
Large displacement misalignment under the action of active faults can cause complex three-dimensional deformation in subway tunnels, resulting in severe damage, distortion and…
Abstract
Purpose
Large displacement misalignment under the action of active faults can cause complex three-dimensional deformation in subway tunnels, resulting in severe damage, distortion and misalignment. There is no developed system of fortification and related codes to follow. There are scientific problems and technical challenges in this field that have never been encountered in past research and practices.
Design/methodology/approach
This paper adopted a self-designed large-scale active fault dislocation simulation loading system to conduct a similar model test of the tunnel under active fault dislocation based on the open-cut tunnel project of the Urumqi Rail Transit Line 2, which passes through the Jiujiawan normal fault. The test simulated the subway tunnel passing through the normal fault, which is inclined at 60°. This research compared and analyzed the differences in mechanical behavior between two types of lining section: the open-cut double-line box tunnel and the modified double-line box arch tunnel. The structural response and failure characteristics of the open-cut segmented lining of the tunnel under the stick-slip part of the normal fault were studied.
Findings
The results indicated that the double-line box arch tunnel improved the shear and longitudinal bending performance. Longitudinal cracks were mainly distributed in the baseplate, wall foot and arch foot, and the crack position was basically consistent with the longitudinal distribution of surrounding rock pressure. This indicated that the longitudinal cracks were due to the large local load of the cross-section of the structure, leading to an excessive local bending moment of the structure, which resulted in large eccentric failure of the lining and formation of longitudinal cracks. Compared with the ordinary box section tunnel, the improved double-line box arch tunnel significantly reduced the destroyed and damage areas of the hanging wall and footwall. The damage area and crack length were reduced by 39 and 59.3%, respectively. This indicates that the improved double-line box arch tunnel had good anti-sliding performance.
Originality/value
This paper adopted a self-designed large-scale active fault dislocation simulation loading system to conduct a similar model test of the tunnel under active fault dislocation. This system increased the similarity ratio of the test model, improved the dislocation loading rate and optimized the simulation scheme of the segmented flexible lining and other key factors affecting the test. It is of great scientific significance and engineering value to investigate the structure of subway tunnels under active fault misalignment, to study its force characteristics and damage modes, and to provide a technical reserve for the design and construction of subway tunnels through active faults.
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Huan Liu, Rui Wang, Junyao Wang, Xingyu Chen, Yunpeng Li, Bowen Cui, Tianhong Lang and Weihua Zhu
Flexible pressure sensor arrays have promising applications in analog haptics, reconfiguration of sensory functions, artificial intelligence, wearable devices and human-computer…
Abstract
Purpose
Flexible pressure sensor arrays have promising applications in analog haptics, reconfiguration of sensory functions, artificial intelligence, wearable devices and human-computer interaction. The force disturbance generated by the connecting material between the sensor array units will reduce the detection accuracy of the unit. The purpose of this paper is to propose a flexible pressure sensor with interference immunity capability. A C-type bridge flexible piezoelectric structure is used to improve the pressure perturbation. The interference immunity capability of the sensor has been improved.
Design/methodology/approach
In this paper, a C-type pressure sensor array structure by rapid injection moulding is manufactured through the positive piezoelectric effect of a piezoelectric material. The feasibility of C-type interference immunity structure in a flexible sensor array is verified by further analysis and experiment. A flexible pressure sensor array with C-type interference immunity structure has been proposed.
Findings
In this paper, we present the results of the perturbation experiment results of the C-type pressure sensor array, showing that the perturbation error is less than 8%. The test of the flexible sensor array show that the sensor can identify the curved angle of up to 120 °, and the output sensitivity of the sensor in the horizontal state reaches 0.12 V/N, and the sensor can withstand the pressure of 80 N. The flexible sensor can work stably in the stretch rate range of 0–8.6% and the stretch length range of 0–6 mm.
Originality/value
In this paper, C-type pressure sensor array structure is fabricated by rapid injection moulding for the first time. The research in this paper can effectively reduce the disturbance of input pressure on the sensor’s internal array and improve the output accuracy. The sensor can intuitively reflect the number of fingers sliding on the sensor by the order in which the maximum voltage appears. Due to the strong interference immunity capability and flexibility of the flexible sensor array mechanism, it has a broad application prospect in the practical fields of haptic simulation, perceptual function reconstruction, artificial intelligence, wearable devices and human–computer interaction.
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Wei Chen, Yucheng Ma, Xingyu Liu, Enguang Xu, Wenlong Yang, Junhong Jia, Rui Lou, Chaolong Zhu, Chenjing Wu and Ziqiang Zhao
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…
Abstract
Purpose
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.
Design/methodology/approach
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.
Findings
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.
Originality/value
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).
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0161/
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Xingyu Ken Chen, Jin-Cheon Na, Luke Kien-Weng Tan, Mark Chong and Murphy Choy
The COVID-19 pandemic has spurred a concurrent outbreak of false information online. Debunking false information about a health crisis is critical as misinformation can trigger…
Abstract
Purpose
The COVID-19 pandemic has spurred a concurrent outbreak of false information online. Debunking false information about a health crisis is critical as misinformation can trigger protests or panic, which necessitates a better understanding of it. This exploratory study examined the effects of debunking messages on a COVID-19-related public chat on WhatsApp in Singapore.
Design/methodology/approach
To understand the effects of debunking messages about COVID-19 on WhatsApp conversations, the following was studied. The relationship between source credibility (i.e. characteristics of a communicator that affect the receiver's acceptance of the message) of different debunking message types and their effects on the length of the conversation, sentiments towards various aspects of a crisis, and the information distortions in a message thread were studied. Deep learning techniques, knowledge graphs (KG), and content analyses were used to perform aspect-based sentiment analysis (ABSA) of the messages and measure information distortion.
Findings
Debunking messages with higher source credibility (e.g. providing evidence from authoritative sources like health authorities) help close a discussion thread earlier. Shifts in sentiments towards some aspects of the crisis highlight the value of ABSA in monitoring the effectiveness of debunking messages. Finally, debunking messages with lower source credibility (e.g. stating that the information is false without any substantiation) are likely to increase information distortion in conversation threads.
Originality/value
The study supports the importance of source credibility in debunking and an ABSA approach in analysing the effect of debunking messages during a health crisis, which have practical value for public agencies during a health crisis. Studying differences in the source credibility of debunking messages on WhatsApp is a novel shift from the existing approaches. Additionally, a novel approach to measuring information distortion using KGs was used to shed insights on how debunking can reduce information distortions.
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Tianyue Feng, Lihao Liu, Xingyu Xing and Junyi Chen
The purpose of this paper is to search for the critical-scenarios of autonomous vehicles (AVs) quickly and comprehensively, which is essential for verification and validation…
Abstract
Purpose
The purpose of this paper is to search for the critical-scenarios of autonomous vehicles (AVs) quickly and comprehensively, which is essential for verification and validation (V&V).
Design/methodology/approach
The author adopted the index F1 to quantitative critical-scenarios' coverage of the search space and proposed the improved particle swarm optimization (IPSO) to enhance exploration ability for higher coverage. Compared with the particle swarm optimization (PSO), there were three improvements. In the initial phase, the Latin hypercube sampling method was introduced for a uniform distribution of particles. In the iteration phase, the neighborhood operator was adapted to explore more modals with the particles divided into groups. In the convergence phase, the convergence judgment and restart strategy were used to explore the search space by avoiding local convergence. Compared with the Monte Carlo method (MC) and PSO, experiments on the artificial function and critical-scenarios search were carried out to verify the efficiency and the application effect of the method.
Findings
Results show that IPSO can search for multimodal critical-scenarios comprehensively, with a stricter threshold and fewer samples in the experiment on critical-scenario search, the coverage of IPSO is 14% higher than PSO and 40% higher than MC.
Originality/value
The critical-scenarios' coverage of the search space is firstly quantified by the index F1, and the proposed method has higher search efficiency and coverage for the critical-scenarios search of AVs, which shows application potential for V&V.
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Xingyu Qu, Zhenyang Li, Qilong Chen, Chengkun Peng and Qinghe Wang
In response to the severe lag in tracking the response of the Stewart stability platform after adding overload, as well as the impact of nonlinear factors such as load and…
Abstract
Purpose
In response to the severe lag in tracking the response of the Stewart stability platform after adding overload, as well as the impact of nonlinear factors such as load and friction on stability accuracy, a new error attenuation function and a parallel stable platform active disturbance rejection control (ADRC) strategy combining cascade extended state observer (ESO) are proposed.
Design/methodology/approach
First, through kinematic modeling of the Stewart platform, the relationship between the desired pose and the control quantities of the six hydraulic cylinders is obtained. Then, a linear nonlinear disturbance observer was established to observe noise and load, to enhance the system’s anti-interference ability. Finally, verification was conducted through simulation.
Findings
Finally, stability analysis was conducted on the cascaded observer. Experiments were carried out on a parallel stable platform with six degrees of freedom involving rotation and translation. In comparison to traditional PID and ADRC control methods, the proposed control strategy not only endows the stable platform with strong antiload disturbance capability but also exhibits faster response speed and higher stability accuracy.
Originality/value
A new error attenuation function is designed to address the lack of smoothness at d in the error attenuation function of the ADRC controller, reducing the system ripple caused by it. Finally, a combination of linear and nonlinear ESOs is introduced to enhance the system's response speed and its ability to observe noise and load disturbances. Stability analysis of the cascade observer is carried out, and experiments are conducted on a six-degree-of-freedom parallel stable platform with both rotational and translational motion.
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YooHee Hwang, Xingyu Wang and Priyanko Guchait
Considerable research has examined the negative consequences of customer incivility on employees (e.g. turnover intention and sabotage behavior toward the customer). However…
Abstract
Purpose
Considerable research has examined the negative consequences of customer incivility on employees (e.g. turnover intention and sabotage behavior toward the customer). However, there is scant research investigating how other customers, as observers, may react to incivility. This knowledge gap should be filled because hospitality services are often consumed in the public setting where customers can observe and be influenced by each other. The purpose of this study is to fill this gap by examining observing customers’ willingness to revisit the company following customer incivility.
Design/methodology/approach
Participants are American consumers recruited from a crowdsourced online panel. Two scenario-based experimental studies in the restaurant setting are conducted. Customer incivility and relationship norms (communal versus exchange) are manipulated, while relationship closeness is measured.
Findings
Study 1 shows that following fellow customer incivility (vs civility), observing customers’ intention to revisit the company was lower when they perceive a distant relationship with the employee. This intention did not differ regardless of incivility and civility when they perceive a close relationship with the employee. Study 2 shows that when observing customers perceive a communal relationship with the employee, their revisit intention was even higher following customer incivility (vs civility).
Practical implications
Hospitality managers need to train employees to identify signs of customer incivility and assume appropriate actions to reduce the negative consequences on observers. Hospitality managers should also communicate their expectations for respectful customer behaviors through an organization-wide campaign. Finally, hospitality businesses should foster a close relationship with their customers, particularly a communal relationship to offset the negative consequences of customer incivility on observers.
Originality/value
This study adds to previous research by challenging the universally negative view of customer incivility. The authors do so by examining the moderating effects of relationship closeness and norms in observer reactions to customer incivility. This study contributes to previous research drawing on script theory and deontic justice theory.
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Jianqing Hu, Hongjun He, Feiliang Dai, Xingyu Gong and Haowei Huang
The purpose of this paper is to develop the efficiency of styrene-acrylate (SA) emulsions for polymer cement waterproof coatings with improved bacteria resistance and mechanical…
Abstract
Purpose
The purpose of this paper is to develop the efficiency of styrene-acrylate (SA) emulsions for polymer cement waterproof coatings with improved bacteria resistance and mechanical properties.
Design/methodology/approach
For effective bacteria resistance and excellent mechanical properties, various concentrations of methacryloxyethylhexadecyl dimethylammonium bromide (MHDB) were synthesised and incorporated into SA emulsions. The properties of SA emulsions modified with MHDB were characterised and compared with those of unmodified ones according to the formulations of polymer cement waterproof coatings.
Findings
The SA emulsions modified with MHDB exhibited significant enhancement of bacteria resistance and mechanical properties over the unmodified ones. The positive quaternary nitrogen and long-chain alkyl groups of MHDB in SA emulsions could attract phospholipid head groups of bacterial and insert them into the cell wall, which results in biomass leak and bactericidal effect. Moreover, MHDB as a softened monomer was beneficial to the synthesis of SA copolymer with low glass-transition temperature (Tg), then the copolymer and cement would form a more compact film which was the main reason for the enhancement of mechanical properties.
Research limitations/implications
The modifier MHDB was synthesised from diethylaminoethyl methacrylate (DEAM) and 1-bromohexadecane. Besides, the congeners of MHDB could be synthesised from DEAM and 1-bromododecane, 1-tetradecyl dromide, 1-octadecyl bromide, etc. In addition, the efficiency of other modifications into SA emulsions for antibacterial polymer cement waterproof coatings could be studied as well.
Practical implications
The method provided a practical solution for the improvement of water-based antibacterial acrylate polymer cement waterproof coatings.
Originality/value
The method for enhancing bacteria resistance and mechanical properties of the waterproof coating was novel and valuable.
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Yuxuan Wu, Wenyuan Xu, Tianlai Yu, Yongcheng Ji and Xingyu Wang
This study aims to address the degradation and damage of traditional bridge expansion joints by proposing a seamless expansion joint device based on polyurethane elastomer (PUE).
Abstract
Purpose
This study aims to address the degradation and damage of traditional bridge expansion joints by proposing a seamless expansion joint device based on polyurethane elastomer (PUE).
Design/methodology/approach
A series of laboratory experiments were conducted to evaluate the performance of PUE, including elasticity recovery, interfacial bonding and hygrothermal aging tests. Indoor model tests were also designed to analyze PUE's performance in actual bridge expansion structures. Based on these evaluations, the design of a seamless PUE expansion joint structure was completed.
Findings
The study reveals that PUE achieves optimal interfacial bond strength with PUC at −30°C after 7 h of curing and adhesive application, with a tensile strength of 9.2 MPa. PUE's elongation at break exceeds 3% at −30°C and retains its toughness and tensile strength after hygrothermal aging. When the beam end rotation reaches 0.0144 rad, PUE maintains a linear elastic state. With a groove width of 340 mm, PUE can withstand compressive displacements over 40 mm and tensile displacements up to 60 mm.
Originality/value
The findings highlight the excellent elasticity recovery and toughness characteristics of PUE, demonstrating the significant improvement in durability of the PUE seamless expansion joint structure and the rationality of the groove width calculation method based on the elongation at break of PUE. The broader impact of this study lies in its potential to innovate the design and maintenance strategies of bridge expansion joints.
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Yanhong Gan, Xingyu Gao, Wenhui Zhou, Siyuan Ke, Yangguang Lu and Song Zhang
The advanced technology enables retailers to develop customer profile analysis (CPA) to implement personalized pricing. However, considering the efficiency of developing CPA, the…
Abstract
Purpose
The advanced technology enables retailers to develop customer profile analysis (CPA) to implement personalized pricing. However, considering the efficiency of developing CPA, the benefit to different retailers of implementing more precise personalized pricing remains unclear. Thus, this essay aimed to investigate the impact of efficiency on participants’ strategies and profits in the supply chain.
Design/methodology/approach
A two-stage game model was introduced in the presence of a manufacturer who sets his wholesale price and a retailer that decides her CPA strategy. The equilibrium results were generated by backward induction.
Findings
Most retailers are willing to develop the highest CPA to implement perfect personalized pricing, but those inefficient retailers with high production costs would like to determine a middle CPA to implement bounded personalized pricing. The retailers’ profits may decrease with the efficiency of developing CPA when the efficiency is middle. In this case, as the efficiency improves, the manufacturer increases the wholesale price, resulting in lower demand and thus lower profits. Moreover, define a Pareto Improvement (PI) strategy as one that benefits both manufacturers and retailers. Therefore, uniform pricing is a PI when the unit cost is high and the efficiency is low; personalized pricing is a PI when the unit cost is low and the efficiency is low or high; otherwise, there is no PI.
Originality/value
This study is the first that investigates how the retailer develops CPA to implement personalized pricing on a comprehensive spectrum, which can provide practical insights for retailers with different efficiencies.