Peer or tutor? The congruity effects of service robot role and service type on usage intention.

The invention of service robots has reduced the labor cost and improved enterprises' efficiency and service quality. However, it is still difficult to enhance consumers' intention to use robot-by-robot design efficiently. Based on social roles of anthropomorphic cues, service robots can be divided into peer (e.g., kind and amiable friends) or tutor (e.g., authoritative and professional experts) robots. From a matching perspective, this paper investigates (1) whether robot role and service type have an impact on consumers' intention to employ service robots in different ways, and (2) how cognitive trust and affective trust can play a mediating role during this process. In this paper, the authors conducted an online a scenario-based experiment and collected a valid sample of 332 consumers. The results show that the participants are more willing to apply the tutor robot in the scenario of utilitarian service, and the peer robot in the scenario of hedonic service. In addition, cognitive trust and affective trust have a matching mediation effect. Specifically, for the utilitarian service, cognitive trust mediates the effect of robot role on consumers' intention to adopt the robots, while the mediating effect of affective trust is not significant. As for the hedonic service, affective trust mediated the effect of robot role on the intention to use, whereas the mediating effect of cognitive trust is not significant.

Experimental study and numerical simulation of the effect of different fiber types on the basic mechanical properties of shotcrete.

This study analyzed the enhancement effects and mechanisms of steel, glass, and polypropylene fibers on the mechanical properties of concrete, aiming to guide the selection of suitable fiber types and dosages for shotcrete projects. Through laboratory tests, numerical simulations, and field experiments, it investigated the enhancement laws of flexural and compressive strengths of concrete with different dosages of these three fibers. Results showed: (1) After 28 days of curing, flexural strength peaked with 2.0% steel, 1.5% glass, and 2.0% polypropylene fibers, increasing by 118.6%, 42.86%, and 138.6%, respectively, over plain concrete. Compressive strength increased by 2.13%, 10%, and 18.3% at optimal dosages of 0.5%, 1.0%, and 2.0% for steel, glass, and polypropylene fibers. Fiber effects on compressive strength were less significant than on flexural strength, with polypropylene fibers outperforming the others. (2) Based on ABAQUS numerical simulations, microscopic analysis indicates that fibers, due to their high yield capacity, enhance the connections between concrete elements, reduce stress concentration, and improve the mechanical properties of concrete. (3) For shotcrete, 2.0% polypropylene fibers were preferred due to high flexural strength and reduced agglomeration. (4) The optimal dosage was applied to a mine's wet shotcrete support, effectively controlling tunnel deformation. These findings provide practical guidance for shotcrete applications.

(FEV3-FEV1)/FVC: a terminal-airflow variable for airway hyperresponsiveness and inflammation prediction in patients with symptoms despite preserved spirometry.

BACKGROUND: Small-airway function assessment is crucial for asthma diagnosis and management. Abnormalities in terminal airflow deserve attention. OBJECTIVE: This study investigated whether the ratio of forced expiratory volume in the second and third seconds to forced vital capacity ([FEV3-FEV1]/FVC) correlates with airway hyperresponsiveness (AHR) and inflammation in patients with preserved spirometry. METHODS: This cross-sectional study enrolled patients with FEV1 ≥ 80% predicted, FEV1/FVC ≥ 0.7, and recurring asthma-like symptoms. Data included demographics, fractional exhaled nitric oxide (FeNO), impulse oscillometry, and spirometry. Univariate and combined models predicting AHR was analyzed in 553 patients and validated in 561. Correlations between sputum inflammation and spirometrics were also assessed. RESULTS: AHR+ patients exhibited higher (FEV3-FEV1)/FVC ratios compared to AHR-. This ratio showed the strongest association with the methacholine dose causing a 20% FEV1 decrease (PD20) and the response dose ratio (RDR)(r = -0.26 and 0.39, respectively; P < .001, both). The area under the receiver operating characteristic curve for AHR diagnosis using (FEV3-FEV1)/FVC was 0.751, increasing to 0.821 when combined with FeNO, confirmed in the validation cohort. (FEV3-FEV1)/FVC was superior to maximal expiratory flow at 50% of forced vital capacity for identifying eosinophilic airway inflammation characterized by elevated FeNO levels. It correlated better with sputum eosinophil count than with the other spirometrics. CONCLUSION: Elevated (FEV3-FEV1)/FVC were evident in AHR+ patients with preserved FEV1/FVC ratios. It serves as a sensitive marker of AHR and airway inflammation correlating with RDR, PD20, and sputum eosinophils, suggesting its utility in monitoring patients at risk for uncontrolled asthma.

Effect of Sintering Temperatures on Grain Coarsening Behaviors and Mechanical Properties of W-NiTi Heavy Tungsten Alloys.

W-NiTi tungsten heavy alloys were prepared by an infiltration process using submicron W powders, and the effect of sintering temperatures on grain-coarsening behaviors and the mechanical properties of W-NiTi tungsten heavy alloys were investigated. The microstructures and mechanical properties were investigated using scanning electron microscopy, X-ray diffraction and compression tests. The results showed that tungsten particles were uniformly distributed in the NiTi binder. The W-NiTi tungsten heavy alloys consisted of B19'-NiTi and body-centered cubic W phases. The average tungsten particle sizes of W-NiTi tungsten heavy alloys sintered at 1400 °C, 1480 °C and 1560 °C were 2.62 µm, 4.04 µm and 5.20 µm, respectively. The average tungsten particle size increased with sintering temperatures, while the densities decreased at higher temperatures. The cavities retained in the W-NiTi tungsten heavy alloy sintered at 1560 °C, which degraded the mechanical properties. The calculated grain growth activation energy of W particles in the NiTi binder was 330 kJ/mol, which was higher than those in conventional W-NiFe and W-NiCo tungsten heavy alloys. The higher activation energy means more difficult diffusion process of W atoms in NiTi binders during sintering. Therefore, finer-grained heavy tungsten alloys were more easily obtained by using NiTi binders. Yield strength of W-NiTi tungsten heavy alloys decreased with increasing sintering temperatures due to coarsened tungsten particles.

When Big Data Backfires: The Impact of a Perceived Privacy Breach by Pharmaceutical E-Retailers on Customer Boycott Intention in China.

The objective of this study was to explore the impact of a perceived privacy breach by pharmaceutical e-retailers on customer boycott intention, especially the mediating role of emotional violation and the moderating effect of customer previous trust. Data were collected via a questionnaire survey of 335 customers of pharmaceutical e-retailers from China. Our research results showed that a perceived privacy breach by a pharmaceutical e-retailer had no direct effect on customer boycott intention; a perceived privacy breach positively affected emotional violation; emotional violation led to customer boycott intention; emotional violation played a mediating role in the relationship between a perceived privacy breach and customer boycott intention; and customer previous trust positively moderated the mediating effect of emotional violation.

Get Close to the Robot: The Effect of Risk Perception of COVID-19 Pandemic on Customer-Robot Engagement.

The purpose of this study was to examine the effect of the COVID-19 pandemic on customer-robot engagement in the Chinese hospitality industry. Analysis of a sample of 589 customers using service robots demonstrated that the perceived risk of COVID-19 has a positive influence on customer-robot engagement. The positive effect is mediated by social distancing and moderated by attitudes towards risk. Specifically, the mediating effect of social distancing between the perceived risk of COVID-19 and customer-robot engagement is stronger for risk-avoiding (vs. risk-seeking) customers. Our results provide insights for hotels when they employ service robots to cope with the shock of COVID-19 pandemic.

I'll Follow the Minority: The Effects of Sales Level on Purchase Intention of Self-expressive Products.

The present study focuses on the naive theory of exclusivity (vs.popularity) triggered by the sales level of self-expressive (vs. functional) products and introduces perceived self-image exclusivity and perceived face threat to explain the effect of self-expressive products' sales levels on consumers' purchase intention. Specially, about 900 young people participated in four experiments, which used T-shirts, pillows, cups, fashion coats and heating blankets as experimental materials. Through four studies, it is found that consumers are more likely to choose self-expressive (vs. functional) products with low sales (vs. high sales) level. In addition, the paper presents a serial mediation effect of perceived self-image exclusivity → perceived face threat, which can explain the "I will follow the minority" effect of self-expressive products. Finally, the study presents the theoretical and practical significance and future research direction.