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关键词： Thick shell Cu@Ag particle   Sintering   Conductive ink   RFID  

摘要： This paper introduces a method to synthesize thick-shell Cu@Ag particles, with nanorod-shape silver wrapped on the copper surface after substitution and reduction reactions. The average size of silver nanorods is less than 50 nm and that of the copper particles is about 1 mu m. The surface morphology, structure, and sintering properties of Cu@Ag particles were characterized in detail. The results show that the sintering temperature of thick-shell Cu@Ag is 127.5 degrees C, which is lower than that of Cu@Ag particles covered with island-shape and block-shape silver nanoparticles. The conductive ink was prepared by mixing it with resin paste, and the bulk conductivity of the conductive paste under different sintering conditions was investigated. The optimal -process parameters were chosen to conduct the printing of radio frequency identification (RFID) antennas. The farthest reading distances achieved by the ultra-high frequency RFID (UHF RFID) and the high-frequency RFID (HF RFID) were 9.4 m and 3.5 cm, respectively, which have good prospect of practical application.

关键词： RFID   IPS   IIoT   smart wheelchair  

摘要： A new Radio-Frequency Identification (RFID) indoor positioning system (IPS) has been developed to operate in environments where the Global Positioning System (GPS) is unavailable. Traditional RFID tracking systems, such as anti-theft systems in clothing stores, typically work within close proximity to exit doors. This paper presents a novel RFID IPS capable of locating and tracking passive RFID tags over a larger area with greater precision. These tags, costing approximately EUR 0.10 each, are in the form of small stickers that can be attached to any item requiring tracking. The proposed system is designed for an autonomous wheelchair, built from scratch, which will be identified and monitored using passive RFID tags. Our new RFID IPS, with a 12 m range, is implemented in this "smart" wheelchair.

关键词： 射频识别   温敏膜   碳纳米管   二氧化钛   接收信号强度  

摘要： 针对现有管道温度检测技术存在的安装复杂、灵敏度不足及有线传输等问题，本研究提出了一种基于碳纳米管-二氧化钛/壳聚糖复合温敏薄膜的柔性超高频射频识别（radio frequency identification，RFID）标签传感器，实现了管道温度的非接触式无线监测。该传感器通过将具有温度响应特性的碳纳米管-二氧化钛/壳聚糖复合薄膜沉积于标签辐射片表面，利用温度变化对标签信号的影响，建立接收信号强度（received signal strength indicator，RSSI）与温度之间的定量关系模型。实验研究表明，该温敏薄膜可显著提升标签的温度响应特性，有效检测范围为25 °C -75 °C。相较于传统检测方法，本传感器具有两大技术优势：其一，柔性基板设计实现了与管道的共形贴附；其二，无线传输特性规避了布线施工的复杂性。研究结果表明，该无线温度传感系统在工业管道监测领域展现出良好的应用前景。

关键词： Radio frequency identification   Sustainable construction   Exploratory factor analysis   Fourth industrial revolution   Sustainable development and developing countries  

摘要： Purpose - This study aims to explore the critical application areas of radio frequency identification (RFID) technology for sustainable buildings. Design/methodology/approach - The quantitative research approach was adopted through a structured questionnaire administered to relevant stakeholders of construction projects. The data collected were analysed with the exploratory factor analysis, relative importance index (RII) and fuzzy synthetic evaluation (FSE). Findings - The study's results have categorised the crucial areas of application where construction industry stakeholders should focus their attention. These areas are divided into four categories: management technologies, production technologies, sensing technologies and monitoring technologies. The findings from the FSE indicate that monitoring technologies represent the most significant category, whereas management technologies rank as the least significant. Moreover, the RII analysis highlights that tools management stands out as the most important application of RFID, while dispute resolution emerges as the least significant RFID application. Practical implications - The study establishes the core areas of RFID application and their benefits to sustainable buildings. Consequently, it helps stakeholders (consultants, clients and contractors) to examine the RFID application areas and make informed decision on sustainable construction. Furthermore, it provides systematic proof that can aid the implementation of RFID in developing countries. Originality/value - The study provides an insight into the possible application areas and benefits of RFID technology in the construction industry of developing countries. It also developed a conceptual frame for the critical application areas of RFID technology in the construction industry of developing countries.

关键词： Sensors   Monitoring   Fabrics   Dielectrics   Substrates   Sensor phenomena and characterization   FCC   Antennas   Antenna measurements   Electronic healthcare   Antenna-based sensing   dielectric properties   dual-band   eHealth   hydration monitoring   low-cost sensors   multifabric applications   radio frequency identification (RFID) sensors  

摘要： Continuous monitoring of body fluids is essential to maintain health and prevent critical issues such as dehydration, especially among those engaged in physical activities, living in harsh environments such as warm climates, or belonging to vulnerable populations. Traditional hydration monitoring solutions often involved complex measurements, required body-worn devices, or relied on batteries, making them impractical for widespread use among the general population. However, the development of low-cost, noninvasive hydration monitoring technology that can be integrated into textiles, together with the generalization of the digital product passport (DPP), could play a crucial role in democratizing and enhancing eHealth. Building upon previous studies, this work delves into the use of ultrahigh-frequency (UHF) radio frequency identification (RFID) antennas as hydration sensors on various fabrics and frequency bands. After dielectric characterization of different fabrics when mixed with synthetic euhydrated and dehydrated sweat, we developed and evaluated different prototypes compatible with different fabrics, achieving a read range four times larger compared with previous works. In a controlled laboratory environment, we achieved 100% accuracy classifying between euhydrated and dehydrated sweat in fabrics with liquid concentrations greater than 50%. Furthermore, the improved classification method ensures compatibility with both the Federal Communications Commission (FCC) and European Telecommunications Standards Institute (ETSI) bands.

关键词： Accuracy   Graph neural networks   Feature extraction   Convolution   Data models   Sensors   Splines (mathematics)   Wireless communication   Adaptation models   Wireless sensor networks   Graph neural network (GNN)   human behavior recognition   radio frequency identification (RFID)   small-world network  

摘要： With the rapid development of the retail industry, enhancing customer experience and operational efficiency has become increasingly critical, where technological integration is key. This study introduces an innovative framework for human behavior recognition that combines graph neural network (GNN) and radio frequency identification (RFID) technology. By embedding RFID signals into the graph structure, we effectively capture the spatial dependencies hidden in the data. Furthermore, the spline convolution technique is utilized to address the spatial dependencies of the signals, achieving accurate and robust human behavior recognition. Facing challenges such as dynamic changes in data dimensions in the retail environment, over-smoothing issues in GNNs, and the effective fusion of multidimensional features, we adopted a graph-based modeling approach. We constructed an adjacency matrix with small-world characteristics using the TopK mechanism and Pearson correlation coefficients, and introduced inception structures and residual connections to increase network width, thereby mitigating over-smoothing phenomena. The introduction of bidirectional long short-term memory network (BiLSTM) readout methods further enhanced the model's ability to process time series information. Experimental results demonstrate the framework's excellent performance in human behavior recognition tasks, with high accuracy and strong robustness, proving not only theoretically feasible but also highly effective in practical applications. Through qualitative analysis, we have improved the interpretability of the framework, providing retailers with a powerful tool for gaining in-depth insights into customer behavior, which helps to optimize customer experience and enhance operational efficiency.

关键词： Radio identification   Laser-induced graphene (LIG)   Chipless-RFID   Near-field   Non-cloneable tag   Authentication   Counterfeit   Cork  

摘要： This work introduces novel, non-cloneable chipless RFID tags designed for authentication, offering a solution to protect product brands, such as wine, liquor, oil, and other liquid products, from counterfeit practices. A unique spectral response of the embedded tag, created by depositing various conductive layers, can be achieved by combining its shape and sheet resistance. To accomplish this, a laser-induced graphene (LIG) layer is formed on a cork substrate (used as a graphene precursor), followed by an electroplating process to enhance conductivity. This paper presents a prototype scanner, designed to characterize the electromagnetic signature of the tags, compatible variable-sized wine bottles and cork stoppers. Preliminary results obtained with complex logo images demonstrate the feasibility of this technology.

关键词： RFID   inventory robot   dynamic inventory management   robotic hand   autonomous mobile robots   antenna manipulator   warehouse automation  

摘要： In contemporary warehouse logistics, the demand for efficient and precise inventory management is increasingly critical, yet traditional Radio Frequency Identification (RFID)-based systems often falter due to static antenna configurations that limit tag detection efficacy in complex environments with diverse object arrangements. Addressing this challenge, we introduce an advanced RFID-based inventory robot that integrates a 3-degree-of-freedom (3DOF) manipulator with vision-assisted dynamic antenna positioning to optimize tag detection performance. This autonomous system leverages a pretrained You Only Look Once (YOLO) model to detect objects in real time, employing forward and inverse kinematics to dynamically orient the RFID antenna toward identified items. The manipulator subsequently executes a tailored circular scanning motion, ensuring comprehensive coverage of each object's surface and maximizing RFID tag readability. To evaluate the system's efficacy, we conducted a comparative analysis of three scanning strategies: (1) a conventional fixed antenna approach, (2) a predefined path strategy with preprogrammed manipulator movements, and (3) our proposed vision-assisted dynamic positioning method. Experimental results, derived from controlled laboratory tests and Gazebo-based simulations, unequivocally demonstrate the superiority of the dynamic positioning approach. This method achieved detection rates of up to 98.0% across varied shelf heights and spatial distributions, significantly outperforming the fixed antenna (21.6%) and predefined path (88.5%) strategies, particularly in multitiered and cluttered settings. Furthermore, the approach balances energy efficiency, consuming 22.1 Wh per mission-marginally higher than the fixed antenna (18.2 Wh) but 9.8% less than predefined paths (24.5 Wh). By overcoming the limitations of static and preprogrammed systems, our robot offers a scalable, adaptable solution poised to elevate warehouse automation in the era of Indu

关键词： 双目视觉   智能识别系统   RFID   爆破块度  

摘要： 为解决矿山爆破块度识别效率低下、精度不足以及复杂环境干扰等难题，本文提出了一种基于双目视觉的爆破块度识别新方法。通过构建YOLOv8实例分割模型，精准提取复杂光照条件下的爆后矿岩轮廓。结合双目测量技术，基于三维坐标转换与视差计算原理，获取碎石的最大尺寸。搭建了室内实验平台，验证了块度识别方法在不同参数下的碎石识别与尺寸计算精度。最后，提出了露天矿爆破块度智能化识别技术架构，开发了块度自动识别与分析系统。室内模拟测试结果表明：较低的拍摄高度有助于提高模型的识别精度，碎石间接触虽对个别目标识别造成影响，但整体精度未显著下降，所有碎石的识别准确率均在85%以上。动态环境下的识别精度略有下降，但80%的碎石尺寸计算准确率仍保持在90%以上，整体误差仍控制在可接受范围内，满足爆破碎石实时监测及后续分析需求。该方法已成功应用于纳米比亚湖山矿，并结合射频识别（RFID）技术获取物料来源信息，实现爆区碎石块度分布（FSD）的动态监测、精确分析与全面评估，为露天台阶爆破效果评价提供了先进的技术手段。

关键词： Backscattering   RFID   LoRa   Internet of Things   Battery free  

摘要： This work proposes a battery-free wireless burglar alarm system based on LoRa backscattering. The system consists of multiple wireless nodes that send an alert when its sensor is triggered. The primary goal is to significantly reduce the power consumption of these wireless nodes, eliminating the need for battery replacements and maintenance associated with commercial systems. The paper addresses several crucial aspects of the application, including the hardware design of the tag, which encompasses energy management up to the RF front-end. Additionally, this paper explores the wireless communication protocol by presenting a fully analog modulation approach to optimize power consumption and system responsiveness. This novel method leverages the intrinsic frequency detection function of commercial LoRa transceivers to determine the origin of backscattered LoRa packets, thereby enabling the integration of a large number of sensors within the same frequency channel, all using a single receiver. Finally, the paper provides a proof of concept validated through on-site measurements.