Search results

This paper aims to present an innovative reconfigurable series-fed microstrip antenna using radiofrequency positive intrinsic negative (RF PIN) diodes for cognitive S-band and C-band satellite communications. The antenna can dynamically reconfigure its frequency, polarization and radiation pattern to meet diverse application needs.

The design involves a reconfigurable four-element microstrip antenna using FR4 substrate and copper patches. RF PIN diodes enable dynamic frequency, polarization and radiation pattern reconfiguration. Simulations and optimizations are performed using CST and HFSS, using techniques like the Nelder-Mead algorithm, particle swarm optimization, covariance matrix adaptation and trust region framework. An antenna prototype is also fabricated to validate the simulations.

The proposed antenna demonstrates significant reconfigurability: it switches between S-band (2.45 GHz, 2.52 GHz) and C-band (5.55 GHz, 5.59 GHz) with bandwidths of 120 MHz and 550 MHz, respectively. It transitions between circular and linear polarization in the S-band and modifies the radiation pattern by 45 degrees, providing an alternative radiation direction in the C-band. The antenna achieves a maximum gain of 5.95 dBi at 2.52 GHz and 93% efficiency at 5.55 GHz. Simulated results closely match those from the fabricated prototype, confirming the design’s validity.

The innovative use of RF PIN diodes enables comprehensive reconfigurability in frequency, polarization and radiation patterns within a single microstrip antenna, meeting the demands of S-band and C-band satellite communications. This study demonstrates superior performance, significant gains and efficiencies across various reconfiguration modes, validated by rigorous simulation and practical fabrication. The simple structural design further distinguishes this study from others in the field.

Travel destinations worldwide are seeking smart ways to reduce the negative impact of tourism, and the public bike rental service (PBRS) is one of them. To investigate the usage intention of this service among visitors, the author of this research employs an integrated approach consisting of two psychological frameworks: the Norm Activation Model (NAM) and the Technology Acceptance Model (TAM).

The integrated NAM-TAM model is implemented to conduct a survey (sample n = 777) with visitors to Hanoi, Danang, and Ho Chi Minh City regarding the factors underlying their intentions to continue using the PBRS TNGo.

Structural equation models suggested that: (1) the NAM-TAM can explain behavioural intention to use a smart PBRS. Perceived Usefulness (PU), Perceived Ease of Use (PE), and Awareness of Consequences (AC) have positive and significant impacts on Attitude Towards Using (AT) and, thus, on Behavioural Intention to Use (BI). Also, Personal Norms (PN) positively influence BI. (2) Among the four independent variables, tourists' AC produces the most potent effect on the intention to continue using a PBRS.

This study can start a new research direction of combining the NAM with other theoretical frameworks to explain customer behaviour in the field of sustainable tourism practices. Future research should explore the proposed model based on comparisons of different tourists’ backgrounds, including nationality, length of stay, spending level, visiting purpose, etc.

This research provides strategic implications for destination management organisations in boosting the use of PBRS amongst tourists, contributing to the environmental sustainability targets of the tourism industry.

This study responds to the existing gap by examining both functional value (indicated by PU and PE) and perceived environmental/social value (proxied by AC) in forming tourists’ attitudes towards PBRS and their usage intention. Our study, therefore, actively contributes to the research stream of tourist behaviour in the field of sustainable tourism practices from the altruistic behavioural perspective.

The purpose of this paper is to extend the Push-Pull-Mooring (PPM) theory to identify the factors influencing Muslim customers’ switching intention to halal-certified cosmetics.

A snowballing sampling method was used to distribute an online questionnaire via social media platforms. Of 403 questionnaires, only 363 were usable. SmartPLS 4 was used to analyse the data using a structural equation modelling approach.

The findings of this paper confirmed that social influence and scepticism have a positive effect on the switching intention to halal cosmetics. However, compatibility with current cosmetic products has a negative effect on the switching intention to halal cosmetics. On the other hand, negative side effects and negative past experiences have a positive effect on scepticism. Scepticism was also found to mediate the relationship between negative side effects and negative past experiences toward the switching intention to halal cosmetics.

The findings of this study primarily benefit cosmetics manufacturers, whether halal-certified or otherwise.

This study extends the PPM theory with negative side effects and negative past experiences. Moreover, this study also introduces new relationships and untested relationships between scepticism and switching intention. This study shows the mediating effects of scepticism on the relationship between negative side effects and negative past experiences toward switching intention.