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关键词： Radiofrequency identification   Encoding   Standards   Decoding   Task analysis   Protocols   Physical layer   RFID   missing tag identification  

摘要： We revisit the problem of missing tag identification in RFID networks by making three contributions. Firstly, we quantitatively compare and gauge the existing propositions spanning over a decade on missing tag identification. We show that the expected execution time of the best solution in the literature is Theta(N+(1-alpha)(2)(1-delta)(2)/epsilon(2)) , where delta and epsilon are parameters quantifying the required identification accuracy, N denotes the number of tags in the system, among which alpha N tags are missing. Secondly, we analytically establish the expected execution time lower-bound for any missing tag identification algorithm as Theta(N/logN+(1-delta)(2)(1-alpha)(2)/epsilon(2)log(1-delta)(1-alpha)epsilon), thus setting the theoretical performance limit. Thirdly, we develop two novel missing tag identification algorithms with the expected execution time of Theta(log logN/logN N+(1-alpha)2(1-delta)2 epsilon(2)) , reducing the time overhead by a factor of up to log N over the best algorithm in the literature. The key technicality in our first algorithm is a novel data structure termed as collision-partition tree (CPT), built on a subset of bits in tag pseudo-IDs, leading to a more balanced tree structure and reducing the time complexity in parsing the entire tree. To further improve time efficiency, our second algorithm integrates multiple CPTs to form a collision-partition forest (CPF), reducing both the number of slots and the quantity of information broadcasting.

关键词： Asymmetric CPW-feed   Bandwidth   Compact antenna   5.8 GHz antenna   RFID  

摘要： In this work, a miniaturized half-side dumbbell-shaped antenna with an asymmetric co-planar waveguide (CPW)-feed is designed and analyzed for the application of radio-frequency identification. This antenna was designed at 5.8 GHz band and operated across the frequency range from 5695 to 5945 MHz (for S11\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text {S}}_{11}$$\end{document} <= - 10 dB), providing the measured impedance bandwidth of 250 MHz. This is achieved within the antenna dimensions of 11.5 x 7 x 1.6 mm3. The simulated return loss characteristics of the antenna were in good agreement with the measured characteristics. The proposed antenna was designed with a miniaturization of about 43.7% compared to a symmetrical CPW-feed antenna and exhibited the same radiation characteristics.

关键词： Radio Frequency Identification (RFID)   Production System   Manufacturing Big Data Analytics  

摘要： Radio Frequency Identification (RFID) technology is widely used for production data collection in manufacturing shop-floors. The RFID-collected manufacturing big data reflects detailed statuses of production processes and manufactured products, which, in turn, can be used to support a comprehensive production analysis. This paper introduces an analytical approach to conduct production efficiency analysis based on the RFID-collected manufacturing big data. The proposed method involves four key steps: data cleansing, data processing, key performance indicator (KPI) estimation, and data analytics. Specifically, speed and quality aspects of shopfloor manufacturing are investigated collectively as production efficiency to support the comprehensive production analysis. The findings highlight the influence of various factors, such as operation date, working hour, and machine failure, on production efficiency.

关键词： Printed circuits   Standards   Microstrip   Directive antennas   Antenna radiation patterns   UHF antennas   Topology   Directive beaming   frequency-scanning antennas   leaky-wave antennas   power recycling   printed-circuit board antennas   RFID UHF antennas   series-fed antennas  

摘要： The efficient series connection of planar leaky-wave antennas (LWA) to obtain directive frequency beam scanning, is proposed in this paper. Conditions for the proper performance are here derived, showing that the distance between antennas must be minimized while optimizing the phase shift introduced by the interconnection. Consequently, the methodology to design the transition is presented by an example using SMA connectors and a meander coaxial cable. Such series arrangement is useful to overcome the restricted directivity of planar LWAs in the UHF band due to limited PCB standard manufacturing sizes, while optimizing the radiation efficiency. The presented theory is validated with practical design examples of microstrip LWA arrays operating in the 900 MHz UHF band. Also, the frequency-beam scanning behaviour of the series-fed LWA array is analysed, demonstrating good performance when the proposed design conditions are satisfied, compared to a non-optimized design which can lead to destructive interference in the desired scanning directions.

关键词： Radiofrequency identification   Batteries   Dual band   Sensors   Microstrip antennas   Receiving antennas   Patch antennas   Diplexer   dual-band   energy autonomous   energy harvesting   MTM-EBG   patch antenna   RFID   sensor   wireless sensor   wireless power transfer  

摘要： This paper presents an energy-autonomous antenna system that combines energy harvesting (EH) with radio frequency identification (RFID) communication to measure the battery charge level in real time. The system employs a dual-band patch antenna, a dual-band matching stub, and a diplexer, which are designed with metamaterial-based electromagnetic bandgap technology (MTM-EBG). Due to the MTM-EBG's uniplanar and via-less design, it can be directly embedded into the antenna and microstrip feed components, thereby contributing to their compactness, lowering cost, and simplifying fabrication. The RFID and EH portions of the system operate at frequencies of 915 MHz and 2.48 GHz, respectively. This system operates by rectifying RF power in the EH band in order to charge a supercapacitor battery, while a varactor imparts phase to the backscattered RFID signal. The phase of reflection is related to the level of charge in the battery, which is then read by the RFID reader. By acquiring the tag and charging information without power, this structure is energy autonomous, so there is no need for a permanent power source that will need to be replaced over time. Using supercapacitors or rechargeable batteries, the proposed structure can provide power for critical functions while monitoring their charging status remotely. The antenna system and RFID/EH architecture have been fabricated and measured, and battery level monitoring has been demonstrated.

关键词： RFID   Data Analysis   KPI   Machine Learning  

摘要： RFID technology has found widespread application in supply chain processes. Previous research has primarily focused on managing products or stocks, with limited attention given to analysing workers' performances through RFID data. This paper proposes a model for analysing employee performance using RFID data in production management. Key Performance Indicators (KPIs) are defined and utilised to process, analyse, and visualise the data through various analysis tools to develop the proposed model. Comparisons are conducted to evaluate employee performance between different groups based on the defined KPI. The model is validated by testing an independent data set, demonstrating its effectiveness in analysing existing data. Predictably, the model has the potential to reduce supervisory and associated costs in case-like applications. (c) 2024 The Authors. Published by ELSEVIER Ltd. This is an open access article under the CC BY-NC-ND license (https://***/licenses/by-nc-nd/4.0)

关键词： RFID systems   Authentication protocol   Security   Privacy   TMIS  

摘要： A cutting-edge idea known as the Internet of Things (IoT) connects different physical items with the online environment. IoT technology is expanding quickly and will soon have an important encounter on how we live our everyday lives. IoT applications use radio frequency identification (RFID) to automatically identify the linked devices. RFID-enabled technologies are becoming more common nowadays for protecting privacy in a variety of industries, including the smart grid, smart cities, and smart education. Healthcare is one of the prominent applications of RFID technology. Patients can receive quick and convenient care at home due to RFID-enabled healthcare solutions. However, there are instances of technology forgery, putting patients' medical information in danger. Utilizing an authentication protocol is extensively regarded as the most efficient way for RFID-enabled healthcare systems to prevent malicious attacks and the misuse of resources. Very recently, Shariq and Singh proposed a lightweight RFID-enabled protocol for healthcare using the properties of vector space. This article presents evidence that Shariq and Singh's protocol has some wrong steps and is also liable to tag anonymity and impersonation attacks. Moreover, we proposed a secured authentication protocol to overcome the flaws of Shariq and Singh's protocol using vector addition, scalar multiplication, and dot products. We analyze the formal security utilizing BAN logic and Scyther simulation tools. The proposed protocol performs better than related protocols regarding costs associated with computation, transmission, storage, and security measures.

关键词： Temperature sensors   Temperature measurement   Sensors   Antennas   Semiconductor device measurement   Temperature distribution   Semiconductor diodes   Sensor systems   cold chain management   setup-independent   temperature sensor   ultra high-frequency radio identification (UHF RFID)  

摘要： Ultra high-frequency radio identification (UHF RFID) technology has been widely used in logistics and chain management. Many methods exist to implement temperature sensing on passive RFID tags, such as utilizing high-cost RFID chips with temperature sensors. The resistance of a semiconductor diode in an RFID chip is temperature-sensitive, and then the discharging time through the reverse-polarized diode could be used to estimate temperature indirectly with the competitive advantage of being low-cost. However, the discharging time is inaccessible in the RFID standard Gen2 protocol, while the persistent time consisting of the discharging time and the charging time is accessible. In this letter, differential data of the persistent time and the charging time are defined, and a mapping model between temperature and differential data is built. An optimal fusion factor is determined by minimizing the regression error of the mapping model under various radiated power levels. This process eliminates the influences of measurement setups, such as relative distance and orientation between the read/write device and tags, on the discharging time. Compared to existing methods, proposed method improves the sensing accuracy from +/- 5 degrees C to +/- 2 degrees C under different measurement setups.

关键词： Cameras   Trajectory   Three-dimensional displays   Sensors   RFID tags   Data mining   Face recognition   RFID   computer vision   multi-modal fusion   human sensing   object manipulation activities  

摘要： Fine-grained recognition of human manipulation activities on objects is crucial in the era of human-computer-object integration. However, there is a lack of solutions for simultaneous recognition of human identity, manipulation activities (including drawing and rotation), and manipulated objects. Therefore, we propose an RF-Camera system that combines RFID and computer vision techniques to address this challenge in multi-person and multi-object scenarios. In RF-Camera, we employ a skeleton-assisted method to extract facial images of target individuals, enabling precise recognition of their identities. To identify manipulation activities, we analyze the 3D hand trajectory and fingertip vector angle, differentiating drawing and rotation manipulation activities. Additionally, we model target person's hand movements to predict phase data of the target tag, enabling the determination of person-object relationships. Implementing RF-Camera using COTS RFID and Kinect devices involves overcoming challenges such as extracting effective data from noisy streams, predicting virtual phase data considering hand-tag offset, and ensuring high tag reading rates in tag-dense scenarios. We conducted experiments involving six participants performing object manipulation activities, including drawing letters/symbols and rotating movements. Extensive experimental results show that RF-Camera achieves over 90% accuracy in recognizing person identity, manipulation activities, and person-object matching in most conditions.

关键词： Internet of things (IoT)   Life cycle assessment (LCA)   Lithium-ion battery   Supply chain management   Radio frequency identification system (RFID system)   system)  

摘要： This article explores the current and future technological pathways of RFID components and quantifies their environmental impacts through life cycle assessment (LCA), and also covering the critical materials and energy use of tags, readers, and backend servers. We assess RFID-enabled lithium-ion battery supply chains with different cathode chemistries - lithium nickel cobalt aluminum oxide (NCA), nickel cobalt manganese oxide (NCM) as case applications. The results indicate that miniaturization and novel antenna materials can reduce the current environmental impacts of tags and readers by 60 % and 4 %, respectively. Direct energy consumption and antennas are the main contributors for tags, while microcontrollers and transceivers are the main contributors for readers. Furthermore, the overall environmental improvements of RFID system outweigh their additional environmental impacts. The use of RFID systems in optimizing battery supply process gives higher reductions in climate change and abiotic resource depletion impacts than switching to low-carbon battery chemistries (i.e. using NCM instead of NCA).