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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.

摘要： The purpose of this paper is to present a design and analysis of hexagonal antenna for Ultra High Frequency (UHF) Radio Frequency Identification (RFID) Reader Application, to embrace the benefits offered by UHF RFID systems. In this design the FR-4 material is used to have medium, low cost and lightweight structure. The proposed antenna made up of hexagonal antenna patch and rectangular shape for the substrate. The antenna is meant to work on a frequency range of 919 MHz to 923 MHz, which is reserved for Malaysia’s UHF RFID system. A voltage standing wave ratio (VSWR) of 1.14 and a gain of 5.87 at 921 MHz was obtained in CST microwave studio. The result of antenna parameter such as bandwidth, return loss and radiation pattern also discussed.

摘要： In this paper, the purpose of this study is to design and analysis the triangular array microstrip patch antenna for application of Radio Frequency (RFID) Ultra High Frequency (UHF). Array antennas are used in RFID application as it offers high gain and directivity to allow a long distance read range. The microstrip patch is arranged in 2 x 2 array and material used is FR-4 with dielectric constant 4.7 and height of 0.16 cm. Design of antenna patch 919 MHz to 923 MHz is designed, built, and measured for UHF RFID application in Malaysia. Fundamentals theory and calculation studies are conducted to analysis the changes and effect in dimension in radio frequency identification RFID antenna. The antenna simulation was run using the CST Studio Suite 2019 as the primary software to model, simulate the results, there are a few parameters that going to be analyze which includes reflection coefficient (S11), Voltage Standing Ratio (VSWR), directivity, gain, radiation pattern and bandwidth.

关键词： disabilities   applications in healthcare   medical sensors   security in wearable devices, RFID assistive technology   RFID sensor tags   cryptography   field montgomery multiplier   cryptosystems   IoT security   ubiquitous computing  

摘要： Radio Frequency Identification (RFID) assistive systems, which integrate RFID devices with IoT technologies, are vital for enhancing the independence, mobility, and safety of individuals with disabilities. These systems enable applications such as RFID navigation for blind users and RFID-enabled canes that provide real-time location data. Central to these systems are resource-constrained RFID devices that rely on RFID tags to collect and transmit data, but their limited computational capabilities make them vulnerable to cyberattacks, jeopardizing user safety and privacy. Implementing the Elliptic Curve Cryptography (ECC) algorithm is essential to mitigate these risks;however, its high computational complexity exceeds the capabilities of these devices. The fundamental operation of ECC is finite field multiplication, which is crucial for securing data. Optimizing this operation allows ECC computations to be executed without overloading the devices' limited resources. Traditional multiplication designs are often unsuitable for such devices due to their excessive area and energy requirements. Therefore, this work tackles these challenges by proposing an efficient and compact field multiplier design optimized for the Montgomery multiplication algorithm, a widely used method in cryptographic applications. The proposed design significantly reduces both space and energy consumption while maintaining computational performance, making it well-suited for resource-constrained environments. ASIC synthesis results demonstrate substantial improvements in key metrics, including area, power consumption, Power-Delay Product (PDP), and Area-Delay Product (ADP), highlighting the multiplier's efficiency and practicality. This innovation enables the implementation of ECC on RFID assistive devices, enhancing their security and reliability, thereby allowing individuals with disabilities to engage with assistive technologies more safely and confidently.

关键词： Frequency division multiple access  

摘要： Parallelizing passive Radio Frequency Identification (RFID) reading is an arguably crucial, yet unsolved challenge in modern IoT applications. Existing approaches remain limited to time-division operations and fail to read multiple tags simultaneously. In this paper, we introduce QuinID, the first frequency-division multiple access (FDMA) RFID system to achieve fully parallel reading. We innovatively exploit the frequency selectivity of the tag antenna rather than a conventional digital FDMA, bypassing the power and circuitry constraint of RFID tags. Specifically, we delicately design the frequency-selective antenna based on surface acoustic wave (SAW) components to achieve extreme narrow-band response, so that QuinID tags (i.e., QuinTags) operate exclusively within their designated frequency bands. By carefully designing the matching network and canceling various interference, a customized QuinReader communicates simultaneously with multiple QuinTags across distinct bands. QuinID maintains high compatibility with commercial RFID systems and presents a tag cost of less than 10 cents. We implement a 5-band QuinID system and evaluate its performance under various settings. The results demonstrate a fivefold increase in read rate, reaching up to 5000 reads per second. © 2025, CC BY.

关键词： Circular polarization   dipole antenna   metasurface   RFID readers   wideband  

摘要： A compact-size wideband circularly polarized dipole array loaded metasurface (MS) is proposed for RFID readers at 2.45 GHz. The proposed array consists of 2 x 2 dipole antennas, two dielectric substrates, a metal ground plane, and a feeding network. The dipoles were printed on the upper substrate (#1), which was suspended over the lower substrate (#2). An MS lattice of 5 x 5 metal plates placed at the bottom of substrate #1 is utilized to improve the impedance bandwidth. For gain enhancement in the high-frequency band, one MS unit cell in the center of the MS lattice is removed. The proposed dipole array is then properly incorporated with a sequential-phase feeding network for circular polarization operations. The final design, with an overall size of 90 mm x 90 mm x 12.032 mm (similar to 0.86 lambda(0) x 0.86 lambda(0) x 0.11 lambda(0) at 2.9 GHz), was fabricated and measured. The prototype array has a measured |S11| < -10 dB bandwidth of 2.07-3.79 GHz (58.7%), a 3-dB axial ratio (AR) bandwidth of 1.80-3.13 GHz (53.95%), a 3-dB gain bandwidth of 2.11-3.47 GHz (48.7%), and a peak gain of 9.52 dBic at 2.7 GHz.