教学课程资源库 更多>>

关键词： Structural health inspection   Passive RFID sensors   Metal cracks  

摘要： Aiming at the limitations of traditional NDT techniques in the field of structural health inspection in detecting cracks and their deployment on metal surfaces, a passive RFID sensor has been designed to detect the width of metal cracks. The sensor is a circle embedded in four rectangular slots with center symmetry. The sensor system model is created using the electromagnetic simulation software HFSS, and simulations are performed in the frequency range of 2-6 GHz to detect metal cracks in the width range of 1.5-2.5 mm. The simulation results show that under the excitation of electromagnetic waves in the y-polarization direction, the cracks in the 0 degrees and 90 degrees directions will cause the frequency shift in different directions with the increase of width. Fitting the width of the crack along the 0 degrees and 90 degrees orientations to the sensor's resonant frequency shift yields sensitivities of 128 MHz/ mm and 114 MHz/mm, correspondingly. The sensor can easily detect surface defects on metal structures while being low-cost, easy to deploy, and has a simple structure.

关键词： Evolutionary computation   Meta-heuristics   Neural network algorithm   Machine learning   Radio frequency identification network   planning   Internet of things  

摘要： Radio Frequency Identification (RFID) technology is recognised as an effective solution for Internet of Things (IoT) applications across various domains. However, scheduling an RFID system presents an NP-hard combinatorial optimisation problem known as the RFID network planning problem (RNP). This problem requires satisfying several criteria, including a minimum number of antennas for full coverage and a balanced load, while avoiding interference for optimal deployment. Previous studies have often relied on arbitrary initial parameters, particularly concerning the number of antennas, leading to suboptimal solutions. This study investigates a novel approach to address the RNP problem by employing a hybrid metaheuristic-based approach incorporating the advantages of artificial neural networks, whereby machine learning methods are implemented to automatically initiate the initial number of antennas. This study introduces a novel approach named 'I-RAENNA', which is evaluated against well-known instances and compared to established methods such as VNPSO, HPSO, CSP, RAE-NNA, and SLIWMBBO. The experimental results demonstrate that I-RAENNA significantly outperforms state-of-the-art solutions, proving its effectiveness in improving RFID system deployment.

关键词： RFID   NFC   HF antennas   UHF antennas   EAS   Reader antennas   RFID antennas  

摘要： This paper presents an overview of antenna designs for passive radio frequency identification (RFID) tags for near field communication (NFC) and electronic article surveillance (EAS) systems. We discussed several antenna designs such as handheld reader antennas and fixed reader antennas for various applications. The paper also provides a brief discussion on RFID technology with its current state-of-the-art applications. We compare NFC and EAS technologies by reviewing contemporary research in these with reported antenna designs and applications. The paper discusses the design procedure for these antennas along with their characteristics and results. Moreover, the results presented by different researchers have been discussed in detail. It has been observed from the presented literature that RFID technology is key to many existing as well as future applications.

关键词： bat conservation   Chiroptera   dispersal   hibernation   Myotis daubentonii   Myotis nattereri   RFID tag   hibernacula   site fidelity  

摘要： In the temperate zone, many bat species depend on underground sites during the autumn mating period and as hibernacula in winter. Anthropogenic or natural alteration or destruction of a hibernaculum may severely threaten the bats that rely on the site, especially if they are not aware of suitable alternatives. Currently, the rate at which bats visit other hibernacula, or disperse between them, is poorly understood. Here, we studied hibernation site fidelity in two European bat species, Daubenton's bat (Myotis daubentonii) and Natterer's bat (Myotis nattereri), that share hibernacula but differ in their hibernation phenology and mating systems. The activity of over 2500 RFID-tagged individuals was monitored using an automated recording system at the entrances of three hibernacula over eight full years. Hibernation site fidelity was high in both species, with only 1.6% of Daubenton's bats and 4.1% of Natterer's bats moving between the monitored sites during their lifetimes. Juvenile bats moved more frequently than adults and contrary to our expectations, in Natterer's bats, more females moved between hibernacula than males. Movements almost always occurred during the autumn mating season, and more frequently between neighboring hibernacula than between distant sites. Finally, we also found that individuals rarely explored more than one of the three entrances to a site, despite their close proximity. Taken together, our results suggest that some juvenile bats may explore multiple sites, but that they rarely disperse to other hibernacula as adults. As a result, most individuals are either not aware of alternative sites or do not regularly update this information. We therefore argue that the creation of new underground objects as a mitigation measure may not function as an immediate compensation for the disturbance or the loss of an existing hibernaculum. Instead, the proactive identification and protection of existing hibernacula should be prioritized.

关键词： Feeder visits   Chickens   RFID   Hock burn   Footpad dermatitis  

摘要： Collecting data on broiler behaviour patterns in group-housed settings can be challenging, as broilers are difficult to recognize individually. However, broiler behaviour patterns can be valuable for assessing health, welfare and performance. Here, individual feeding patterns of group-housed broilers were studied. Data on feeder visits of 58 randomly selected and subsequently RFID-tagged broilers were used, that were housed in a group of approximately 800 birds in a 45 m2 pen. Feed and water were provided ad libitum, with a total of 16 feeders available to the broilers. All feeders except one (due to farm equipment blocking the access) were fitted with an RFID antenna to detect presence of the broilers at the feeders. The number of feeder visits and feeding durations at the individual level during the period from 20 to 30 d old were examined. In addition, birds' individual body weights (g) were determined at 14, 21, 27 and 35 d of age, and at 21, 27 and 35 d of age gait scores were determined by experienced observers. The feeders used within the pen (i.e., whether feeding occurred in one area or was spread out across the pen) varied between individuals, and for some birds also changed with age. Furthermore, with higher body weights at 14 d of age, the number of different feeders visited in a day was lower (estimate = -0.011, P = 0.002) and the mean feeding bout duration was higher (estimate = 0.130, P = 0.007). In contrast, larger body weight gain between 14 and 35 d of age was related to more different feeders visited within a day (estimate = 0.028, P = 0.005) and shorter feeding bout durations (estimate = -0.390, P = 0.005). No relationships of feeding descriptors with gait classification were observed. Overall, feeding patterns vary between individual broilers and, given the observed relationships between feeding patterns and weight gain, feeding patterns have potential to be informative for broiler growth in research and commercial conditions.

关键词： RFID-based monitoring   Respiration monitoring   Heart rate monitoring   Driving scenarios  

摘要： The health status of drivers directly affects traffic safety, particularly as fatigue or sudden illness can lead to serious traffic accidents. Existing monitoring methods are challenging to apply effectively in complex in-vehicle environments. This paper presents VeHealth, a wireless in-vehicle monitoring system based on Commercial Off-The-Shelf RFID devices that can continuously monitor respiration rate (RR) and heart rate (HR) in real driving scenarios. The system collects amplitude and phase information from RFID signals through tags installed on the chest, abdomen, and inside the vehicle, utilizing a BPNN-Optuna model for RR and HR predictions. Results based on the experimental data of 14 volunteers show that VeHealth achieves prediction accuracies of 95.8%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$95.8\%$$\end{document} and 97.3%\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$97.3\%$$\end{document} for RR and HR, respectively. By designing an optimal RFID antenna layout, the monitoring range is improved, minimizing environmental noise and vehicle interference, thereby validating the system's effectiveness and reliability under various driving conditions.

关键词： 5G/6G network   network performance   radiofrequency identification   resource optimization  

摘要： In the rapidly evolving landscape of 5G/6G networks, efficient resource optimization is critical to addressing the escalating demands for high-speed, low-latency, and energy-efficient communication. This study explores the integration of Radio Frequency Identification (RFID) technology as a novel approach to enhance resource management in 5G networks. The motivation behind this research lies in overcoming persistent challenges such as spectrum congestion, high latency, and inefficient load balancing, which impede the performance of traditional resource allocation methods. To achieve this, RFID tags were embedded in critical network components, including user devices, base stations, and Internet of Things (IoT) nodes, enabling the collection of real-time data on device status, location, and resource utilization. RFID readers strategically placed across the network continuously captured this data, which was processed by a centralized controller using a custom-designed optimization algorithm. This algorithm dynamically managed key network resources, including spectrum allocation, load balancing, and energy consumption, ensuring efficient operation under varying network conditions. Simulations were conducted to evaluate the performance of the RFID-based model against traditional 4G dynamic resource allocation techniques. The results demonstrated substantial improvements in key performance metrics. The proposed system achieved a 25% increase in spectrum utilization, a 30% reduction in average latency, a 15% boost in network throughput, and a 20% decrease in overall energy consumption. These gains highlight the effectiveness of the RFID-based optimization model in meeting the stringent performance requirements of 5G networks, particularly in high-density deployments. This study provides a scalable, cost-effective solution for optimizing resource management in 5G and lays the groundwork for future advancements in 6G networks. By leveraging real-time data and intelligent re

关键词： Complex conjugate impedance match   Loop antenna   Metallic circular tag   Radio frequency identification(RFID)   Circular polarization  

摘要： In this paper layout of long detection range radio frequency identification tag antenna mountable on metallic surface is presented. This tag antenna layout consists of two non-connected L-shaped load bars and two sectorial patches electrically connected through seven pairs of vias and conducting rear-plane to form a loop antenna. This proposed tag antenna can be tuned in wide range for impedance matching and introduces circular polarization. The tag antenna characteristics are also measured on metal plate. The results show that maximum detection range of the specimen, placed on metallic plate found to be 8.4 ms. The measured 10 dB bandwidth of circular tag antenna is 17 MHz (906-923 MHz) with simulated 3 dB axial ratio bandwidth of 13 MHz. This circular tag antenna is simulated with 4 W EIRP reader.

关键词： Steel-concrete interface   Relative humidity   RFID   MEMS sensor   Reinforcement spacer  

摘要： Moisture at the steel-concrete interface (SCI) can influence the durability of reinforced concrete but a fundamental understanding of its effects on corrosion initiation and propagation remains inconclusive. This is partly due to a lack of reliable, non-destructive monitoring techniques. This study introduces a novel approach leveraging 3D-printed reinforcement spacers with embedded RFID-MEMS sensors to enable in situ, real-time relative humidity monitoring at the SCI. Concrete specimens with different water-to-cement ratios (0.40, 0.55) and curing ages (3, 14 days) were exposed to 50 degrees C and 65 % RH, 21 degrees C to produce varying degrees of porosity and moisture content. The results show that precise measurements with a maximum difference of +/- 2 % can be obtained for exposure humidity up to 90 % RH. However, a reduction in precision occurred above 93 % RH due to condensation effects. Crucially, this work demonstrates the first successful integration of RFID-MEMS sensors in 3D-printed spacers to quantify SCI moisture states non-destructively, providing actionable insights for corrosion risk assessment tailored to concrete composition and environmental exposure.

关键词： Interference   Feature extraction   Radiofrequency identification   Authentication   Accuracy   Security   Logic gates   Training   Physiology   Legged locomotion   Gait recognition   RFID   continuous user identification   tags  

摘要： Continuous user identification could facilitate large-scale identity-based services, potentially including access control, security management, personalized services, and beyond. Although current RFID-based user identification systems demonstrate effective performance in single-user scenarios, they exhibit a lack of robustness and accuracy when extended to multi-user environments. In this paper, we propose RF-UI, a low-cost continuous user identification system that can tolerate different interference factors (e.g., appearance changes, inconsistent walking paths). The intuition underlying our design is that when multiple users traverse the radio gate sequentially, the received signal is dominated by the user traversing the radio gate. We develop an algorithm that utilizes phase energy fluctuation to separate signals from different users and extract valid gait-related patterns by applying neighborhood energy sliding windows. Then, we construct a Joint Similarity Matrix (JSM) for characterizing gait features that are robust against various interference factors. Finally, RF-UI achieves cost-effective data augmentation through the deployment of only a few additional tags. Extensive experiments show that RF-UI achieved an accuracy of 94% under various interference factors and maintained a high accuracy of 92.8% in continuous user identification.