Ecological degradation is an escalating global threat. Increasingly, people are expressing awareness and priority for concerns about environmental problems surrounding them. Environmental protection issues are highlighted. An appropriate information technology tool, the growing popular social network system (virtual community, VC), facilitates public education and engagement with applications for existent problems effectively. Particularly, the exploration of related involvement behavior of VC member engagement is an interesting topic. Nevertheless, member engagement processes comprise interrelated sub‐processes that reflect an interactive experience within VCs as well as the value co‐creation model. To address the top‐focused ecotourism VCs, this study presents an application of a hybrid expert‐based ISM model and DEMATEL model based on multi‐criteria decision making tools to investigate the complex multidimensional and dynamic nature of member engagement. Our research findings provide insightful managerial implications and suggest that the viral marketing of ecotourism protection is concerned with practitioners and academicians alike.

In this work, the effect of relative humidity, RH, on the readouts of five light-scattering-based PM sensors were investigated by using particles composed of different hydroscopic materials and comparing the readouts with those measured by Tapered Element Oscillating Microbalance (TEOM). It was found the RH has various effects on the readouts of PM sensors, highly depending on the hydroscopic property of particles. Negligible RH effect on the PM sensors’ readouts was observed for hydrophobic particles while significant increase in the readouts was observed for hydroscopic particles at the RH setting higher than the deliquescence relative humidity, DRH, of particle materials. For particles in the binary components, the effect of the mixture deliquescence on the sensor readouts depends on the hygroscopicity of composite materials (e.g., NaCl + Glucose; NaCl + OA; NaCl + K₂SO₄). In the case of NaCl + OA, the water uptake of resultant NaCl + OA particles is less than that of pure NaCl and OA (because of the possible formation of less hygroscopic di-sodium oxalate, Na₂C₂O₄, in particles). The readouts of PM sensors were also influenced by the mixing status of particles, i.e., internally vs. externally mixed. The correlation slopes for different PM sensors were compared. More, the sampling misalignment was found affecting the readouts of some PM sensors. It is thus suggested to calibrate PM sensors using field particles under the application environments for getting PM data in good quality (assuming that the seasonal change of field RH, and the size distribution and composition of field particles is minor). Copyright © 2021 American Association for Aerosol Research

Nature Photonics offers a unique mix of news and reviews alongside top-quality research papers. Published monthly, in print and online, the journal reflects the entire spectrum of photonics and optics.

In recent years, many emerging information technologies have been applied to learning environments in an attempt to overcome drawbacks associated with traditional teaching environments. Some of these technologies have been shown to improve learning outcomes and learning motivation. Advances in wireless communications have raised research interest in the development of ubiquitous learning (u-learning) environments and their impact on learner attitudes and behavior. This study reports the use of augmented reality (AR) technology to create virtual objects for use in mobile devices to create a context-aware, AR-enabled guided tour application for outdoor learning. The goal is to provide learners with a friendly, interactive interface and rich, engaging media to stimulate intrinsic motivation and learning performance. The main advantages of the proposed system include the following: (1) it helps stimulate learning intention through pursuing outdoor learning objectives, (2) AR technology provides learners with contextual information related to the outdoor learning environment, and (3) it enhances learner retention of teaching contents easily with the situated learning strategy.

Integrated sensor systems (ISS) are the promising solutions to the multi-probe design of biomedical sensors for energy efficient wireless body area networks (WBANs). To improve energy efficiency and communication quality-of–service (QoS) of integrated sensor hubs (ISHs), a cross-layer energyaware resource allocation (CLEAR) is proposed to exploit the characteristics of medium access control (MAC) and physical (PHY) layers of WBANs. The proposed MAC protocol applies a twin-token bucket model and real-time scheduling to the active superframe interleaving and beacon shifting techniques defined in the IEEE 802.15.6 standard. In addition, the proposed period transformation controlling task end-to-end delay improves the QoS while reducing packet collisions. The proposed PHY protocol is a hybrid of the transmit power control (TPC) and link adaption (LA) strategies, which coordinates the receiver and transmitter with link parameters including data rate, bit error ratio, receiver sensitivity, transmission power, modulation, etc. It adapts the link quality due to human postures or movements to meet the required QoS while minimizing the energy consumption of the transceiver front-end. Experimental results show that CLEAR outperforms existing methods in terms of packet delivery ratio, delay, bandwidth utilization and energy consumption. In particular, CLEAR reduces average end-to-end delay by 21% as compared to existing methods, and saves an average of 18% of energy consumption over the TPC and LA-based methods at a power of -25dBm while achieving a maximum 0.05 packet error ratio.