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关键词： 二十四节气   射频识别   《念奴娇·赤壁怀古》   信息传感设备   互联网连接   智能化识别   苏轼  

摘要： 纵向1.出自苏轼的《念奴娇·赤壁怀古》,上一句是“故垒西边,人道是”。2.把所有物品通过射频识别等信息传感设备与互联网连接起来,实现智能化识别和管理。3.二十四节气之第九个节气。4.植物,花朵长在果实内部。5.指仔细地阅读。6.第38届奥斯卡金像奖最佳影片。

关键词： Antennas   coils   heaters   inductors   RFID   rectifiers   resistors   wireless power transfer (WPT)  

摘要： research in passive flexible circuits for wireless power transfer (WPT) such as coils and resonators continues to advance, limitations in their power handling and low efficiency have hindered the realization of efficient all-printed high-power wearable WPT receivers. Here, we propose a screen-printed textile-based 6.78 MHz resonant inductive WPT system using planar inductors with concealed metal-insulator-metal tuning capacitors. A printed voltage doubler rectifier based on silicon carbide diodes is designed and integrated with the coils, showing a power conversion efficiency of 80%-90% for 2-40 W inputs over a wide load range. Compared to prior wearable WPT receivers, it offers an order of magnitude improvement in power handling along with higher efficiency (approaching 60%) while using all-printed passives and a compact rectifier. The coils exhibit a simulated specific absorption rate under 0.4 W/kg for 25 W received power, and under 21 C-degrees increase in the coils' temperature for a 15 W DC output. Additional fabric shielding is investigated, reducing harmonics emissions by up to 17 dB. We finally demonstrate a wirelessly-powered textile-based carbon silver Joule heater, capable of reaching up to 60 C-degrees at 2 cm separation from the transmitter, as a wearable application, which can only be wireless-powered using the proposed system.

关键词： Temperature measurement   Fixed bed reactor   Process monitoring   RFID   3D printing  

摘要： Measuring axial temperature profiles in fixed bed reactors is essential for an optimal and safe operation. Typically, thermocouples are used which influence the bed structure - especially in arrangements with a low ratio between tube and particle diameter - and thus local transport phenomena and reaction rates. In this publication, Radio-Frequency Identification (RFID) tags are used for temperature measurement in fixed beds without disturbing the bed structure. Therefore, the temperature is compared in a tubular fixed bed (D = 25.4 mm) of ceramic rings (d(p) = 10 mm) measured with RFID tags and thermocouples at similar axial positions at different temperature levels 20 < T < 140 C-degrees. By integrating an RFID tag into a particle using 3D printing, the disturbance of the fixed bed by the measurement device can be even completely avoided. It is shown that the overall values of temperature and the dynamic measurement with RFID tags is comparable to measurements using thermocouples. However, significant measurement gaps can occur, especially with unfavorable antenna-tag alignment or small antenna spacing. As a summary, it is possible to measure temperature in fixed bed reactors using RFID technology without requiring direct access and thus disturbing the bed structure. Finally, current shortcomings of RFID are discussed, and research needs presented.

关键词： damage detection   structural monitoring   wireless sensors   UHF-RFID tags   masonry structures   out of plane behavior   experimental data  

摘要： This paper reports a novel investigation in applying commercial Ultra High-Frequency RFID tags (UHF-RFID tags), which are widely used in logistics as sensing elements in civil engineering structures, particularly for monitoring out-of-plane displacements of brick masonry walls. Both laboratory tests and in situ experimental tests assessed the feasibility of the proposed application. Laboratory tests showed a very satisfactory response while the in situ experiments showed a weaker response. Nevertheless, the potential reliability of the proposed technique can be stated. The authors traced back the causes of the performance decrease to environmental interference, mainly due to the extensive presence of a rigid steel frame surrounding the out-of-plane loaded panels. Measurements of displacements, in fact, are obtained indirectly from the phase of UHF-RFID signals that strongly suffer from multipath generated by metallic surfaces. Despite some limitations, the proposed measurement technique permits a reliable and sustainable approach to the monitoring of structures. The use of commercial UHF-RFID wireless tags, in fact, assures easy and fast installation operations and assures the possibility of placing a large number of sensors over the structure with very low maintenance costs with respect to the more traditional monitoring techniques. Moreover, using very thin and small commercial UHR-RFID tags on cultural heritage structures can represent an opportunity for sustainable long-time monitoring with reduced costs. Overall, the results of this study are sufficiently satisfactory to be considered as the opening of new possible scenarios in wireless structural monitoring in the civil engineering field. The authors propose as future work to use UHF-RFID tags for the real-time monitoring of an existing masonry facade that, not being characterized by the presence of a steel frame, can potentially assure an adequate response and properly transmit the electromagnetic signal.

关键词： Cybersecurity   Physical security   Smart home   Smart locks   IoT   Bluetooth   RFID  

摘要： Nowadays domestic smart security devices, such as smart locks, smart doorbells, and security cameras, are becoming increasingly popular with users, due to their ease of use, convenience, and declining prices. Unlike conventional non -smart security devices, such as alarms and locks, performance standards for smart security devices, such as the British TS 621, are not easily understandable by end users due to the technical language employed. Users also have very few sources of unbiased information regarding product performance in real world conditions and protection against attacks from cyber attacker -burglars and, as a result, tend to take manufacturer claims at face value. This means that, as this work proves, users may be exposed to threats, such as theft, impersonation (should an attacker steal their credentials), and even physical injury, if the device fails and is used to prevent access to hazardous environments. As such, this paper deploys several attacks using popular wireless attack vectors (i.e., 433 MHz radio, Bluetooth, and RFID) against domestic smart security devices to assess the protection offered against a cyber attacker -burglar. Our results suggest that users are open to considerable cyber physical attacks, irrespective if they use lesser known (i.e., no name) or branded smart security devices, due to the poor security offered by these devices.

关键词： RFID   missing tag   unknown tag   continuous tag recognition   communication time lower bound   optimal protocol  

摘要： Mobile radio frequency identification (RFID) systems typically experience the continual movement of many tags rapidly going in and out of the interrogating range of readers. Readers that are deployed to maintain a current, real-time list of tags, which are present in the interrogating zone at any moment, must repeatedly execute a series of reading cycles. Each of these reading cycles provides the readers very limited time to identify unknown tags (those newly entering into the reader's range), and, at the same time, to detect missing tags (those just leaving the reader's range). In this paper, we study the continuous tag recognition problem, which is critical for mobile RFID systems. First, we obtain a lower bound on communication time for solving this problem. We then design a near-OPTimal protocoL, called OPT-L, and prove that its communication time is approximately equal to the lower bound. Finally, we present extensive simulation and experimental results that demonstrate OPT-L's superior performance over other existing protocols.

关键词： RFID   Laser Telemetry   Design science   Logistics   Location of objects in space   Automatic identification of the products  

摘要： The idea of Industry 4.0 is a stage of revolution in terms of new solutions and advanced technology, as well as artificial intelligence. Micro and macroeconomic factors generate the need to modify logistics and production processes in enterprises. One of the changes is the organization of warehouse management. The aim of the article is to indicate the possibility of using RFID technology in conjunction with Laser Telemetry in the location of objects in space along with the visualization of this location. In addition, the study aims to merge passive RFID technology with laser scanning to produce a system that can identify and locate objects in a virtual Computer-Aided Design (CAD)-based 3Dimensional (3D) environment. The described case study is the result of research conducted as part of the implementation project. This paper describes the steps to be taken and the creation of a system that will use RFID technology and that will enable the identification of objects in the space of computer systems. For this purpose, it was possible to create a system that will identify objects using RFID and Laser Telemetry in 3D space.

关键词： microstrip circuits   microwave antennas   radiofrequency identification   wireless LAN  

摘要： This letter proposes a novel cross-shaped structure-based parallel coupled line transformer and its application to tag antenna for 920-MHz radio frequency identification (RFID) and 5-GHz WiFi Cross-Technology Communication (CTC). This transformer can be tuned by some lumped capacitors and the equivalent transmission line length for high order harmonic matching. The WiFi is applicable for tourism crowd counting and its counting accuracy may be increased with an additional number of the virtual WiFi Access Points contributed by 5-GHz resonance of said tags attached with touristic metallic objects. To study the 5-GHz resonance of these tags the tag antenna is a square patch with a rectangular slot built with 3D acrylonitrile butadiene styrene printing material. The working frequency of the antenna is around 920 MHz, which can achieve a gain of 5.4 dBi and there is also a resonance at 5.6 GHz with a gain of -6.7 dBi. When the capacitor is tuned, the 5-GHz band of WiFi is varied from 5.2 to 5.6 GHz applicable to emerging WiFi 5 and 6 CTC applications. It is anticipated that the prototype tag provides a flexible tourism crowd counting solution using CTC in the future. This letter presents the design of parallel coupled line-based impedance transformer operated for 920-MHz RFID and 5-GHz WiFi Cross-Technology Communication (CTC). The design is useful for emerging CTC-based tourism crowd counting when the ultra-high frequency (UHF) RFID tags are considered virtual WiFi Access Points in public facilities of touristic areas. image

关键词： Nanomaterial   UV sensitive   Microstrip antenna   RFID  

摘要： This study investigates a coreless radio frequency identification (RFID) photosensitive sensor tag that employs a nanocomposite material comprising molybdenum disulfide (MoS2), cobalt oxide (Co3O4), and reduced graphene oxide (RGO). The photosensitive sensor tag exhibits commendable photosensitivity performance, which has been evaluated through comprehensive sensitivity, response characteristic, and stability testing. Upon exposure to UV irradiation at intensities of 20 mW/cm2 and 200 mW/cm2, the input return loss undergoes a change of 20.933 dB. Within the range of 20 mW/cm2 to 200 mW/cm2, the photosensitive sensor tag demonstrates a response time of 15.4 s and a recovery time of 30.6 s. These results provide compelling evidence that the MoS2/Co3O4/RGO nanocomposite material, functioning as a photosensitive material, exhibits exceptional sensitivity, responsiveness, and repeatability.

关键词： RFID gate   Logistics   Machine learning   Supervised learning   Package size estimation  

摘要： This paper introduces a new approach for performing package classification and sizing using Radio-Frequency Identification (RFID) systems. This technique is applicable when packages are labeled with or contain multiple RFID-tagged items. During the interrogation of the tags, received signal strength (RSS) statistics and other information, such as the frame count or the reading time, are collected by the reader and used to predict the package type from a set of candidate classes using an Artificial Neural Network (ANN). The primary challenge lies in acquiring sufficient training data for a target scenario to ensure reliable predictions. To address this, a two-phase training process based on transfer learning is adopted. Initially, a base model is developed using synthetic data generated from a detailed RFID simulator, designed to suit diverse scenarios, establish detailed link budgets, and comprehensively simulate the communication protocols. This model is then refined using a small dataset collected experimentally in the actual scenario. This method was validated in a real testbed with four different package types. The base model was trained using 1000 synthetic samples per package type (4000 in total), whereas the refined model was trained with a dataset consisting of only 25 real interrogation traces (samples) per package type (100 in total). The experimental samples were obtained using a software-defined radio unit, the Ettus B210 Universal Software Radio Peripheral (USRP) platform. This experiment achieved an accuracy of over 92%. In summary, this approach introduces a new feature to existing RFID setups, demonstrating potential for advanced package handling and cost optimization in the logistics sector.