教学课程资源库 更多>>

关键词： Radiofrequency identification   Privacy   Protocols   Security   Authentication   Databases   Analytical models   RFID scheme   authentication   privacy  

摘要： RFID technology is increasingly used in various areas of society, where privacy plays a critical role. Due to this aspect, a sustained effort has been devoted in recent years to develop privacy models for RFID systems. Two widely accepted such models are Vaudenay's model and the HPVP model. An incursion into the broad diversity of the RFID schemes developed so far shows that many of them do not assure privacy in any of the two models. That is either due to design errors or because their authors did not run any privacy analysis or have used weaker ad hoc privacy models. This article presents five design scenarios underlying constructions of RFID schemes that cannot provide certain levels of privacy in any of the two models. Each scenario is richly exemplified by RFID schemes proposed in the literature, and it is concluded by a lesson to guide us to a better design of such schemes.

关键词： Boulder movement   RFID   Geomorphological control   Fast ice   Ice-rafting   Ice-pushing  

摘要： One hundred mega-boulders were tagged to survey their movements (RFID) for five winters (2012-2017) in Sainte-Luce, St. Lawrence Maritime Estuary, where the foreshore is frozen for two to four months per year. In addition, four boulders were fitted with accelerometers to determine the exact periods of motion. It was found that 81% of the boulders moved during at least one of the winters studied. The maximum transport recorded in one winter was 151.87 m for a 3.1 t boulder, but most boulders moved shorter distances (2012-2017 average transport: 9.74 m, standard deviation 23.71). The relationships between length/direction of boulder movements and fast-ice activity as well as weather and oceanic conditions were analyzed. 61% of mobility events took place at the end of the ice period during ice-foot break-up by storm waves or melting, but 37% took place at the beginning of the fast-ice phase during storms and/or high tide, which was unexpected. The length and direction of transport was found to depend on conditions during ice break-up (wind, waves, currents, ice thickness), which have large interannual variabilities. However, a greater proportion of boulders moved landward between 2012 and 2017. Two transport modes occurred: short pushing by ice floes and ice-rafting over longer distances. The first is much more common (70 to 90%) while the second seems to be more frequent during cold winters, when ice is thicker. Moreover, we demonstrated that the geomorphological setting exerts a strong control on boulder transport distance. The longest movements took place near mean sea level, where the ice foot is thicker and the rock platform smooth while cobble and boulder pavements inhibit movements.

关键词： RFID tags   Microstrip   Resonant frequency   Resonators   Polarization   Semiconductor device measurement   Surface waves   Chipless RFID   cross polarization   depolarizing   orientation insensitive   radar cross section (RCS)   scatterer  

摘要： The ground plane has never been considered as a degree of freedom to be used for chipless radio frequency (RF) identification (RFID) tag design purposes. For the first time, we show that the interaction with the ground plane can be exploited to achieve challenging designs, such as depolarizing tag insensitive to orientation (i.e., nonzero cross polar for any roll angle). The principle relies on the perturbation of the ground plane symmetry with merely one microstrip dipole placed near the edge of the substrate. Chipless RFID tags are realized using three different shapes of the substrate (square, octagonal, and circular) to achieve multiple edges. The measurements are performed in a semianechoic and office environment with tag attached to objects (cardboard box and metallic plate). The measured results of the square chipless RFID tags present magnitude variations (< 10 dB) but are detectable over a full 360 degrees even in real environment yielding an "orientation-insensitive" detection system. Compared to previous designs, the frequency variability of the peaks is negligible.

关键词： Chipless radio-frequency identification (RFID)   image processing   millimeter wave   radar imaging   RFID  

摘要： Recently, a novel chipless radio-frequency identification (RFID) concept based on polarimetric radar barcodes was introduced. These tags are similar to the well known optical quick response codes (QR codes). In polarimetric radar barcodes the information is stored as polarimetrically coded areas arranged in a grid and read out by an imaging radar. This paper presents a novel concept for elegantly creating polarimetric barcodes based on dipole scattering domains. Each scattering domain consists of several hundred dipoles. The dipoles are either uniformly arranged at a specific angle, which produces a specific angle-dependent polarization response, or randomly oriented to produce an unpolarized response. In order to read out the polarimetric information stored in the tags, the position and rotation of the radar barcodes needs to be determined. Our research reveals that using three reference elements and a novel decoding algorithm, a position- and rotation-tolerant readout is possible. To reduce distortions caused by the surface of the structure carrying the dipoles, different matching layer concepts were investigated. The novel chipless RFID tag concept is tested using a fully polarimetric W-band (75-110GHz) imaging radar. The implemented setup allows for a theoretical data capacity of 1.92 bit/cm(2) on a single layer PCB. In our measurements, we achieved a data capacity of 1.52 bit/cm(2). Utilizing the chosen tag size of 45mm x 45mm resulted in a tag with a greater than 30 bit data capacity, which is an excellent value for chipless RFID.

关键词： Energy-consumption   Tag identification   Anti-collision   RFID  

摘要： The advancement of RFID (Radio Frequency Identification) has facilitated its widespread incorporation and caused an increase in the deployment of these solutions in a variety of contexts and constraints. These constraints are generally due to the quantity and the mo-bility of tags and readers utilized, both of which have an impact on the RFID system's effi-ciency by causing tag collisions. Whereas numerous solutions to the problem of tag colli-sions have been presented, few of them have been concerned with reducing collisions, en-ergy consumed, and maximizing throughput at the same time. This article proposes an ap-proach to estimate tags for attaining these objectives based on an x factor, which functions as a reward or a penalty depending on the performance of the frame. When compared to previous collision reduction protocols, simulations reveal that our solution achieves the highest performance in terms of throughput, collisions, and energy consumed.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative. This is an open access article under the CC BY license ( http://***/licenses/by/4.0/ )

关键词： Backscattering   bending   conductive yarns   M6E Kit   read range   rocky 100   skin contact   surgical masks   textile   textile antenna   ultrahigh frequency radio frequency identification (UHF-RFID)  

摘要： Ultrahigh frequency (UHF, 865-868 MHz) radio frequency identification (RFID) devices are expected to be implemented in many health-caring areas. In this article, we present three progressive designs of textile UHF-RFID antennas on surgical masks using a function-extensible integrated circuit (IC) chip (Rocky 100). The simulated and measured resonance curves of the designs all match well (vertical bar S-11 vertical bar < -20 dB at 868 MHz) and the maximum realized gain are improved progressively in order to overcome the difficulty of the chip low sensitivity and increase the maximum read range. The best type (Design 3) is selected and its read range measured by the RFID reader (M6E Kit) can reach 2.5 m in air. In addition, several reliability validation measurements are performed, such as bending and skin contact, and maximum read range can reach 1.1 m considering the on-body worn worst case. The proposed Design 3 allows common use as a tag for tracking or safe distance alert under an epidemic situation. Alternatively, for the used function-extensible chip, the design can be applied to many different types of sensors for various application scenarios.

关键词： future consumer   microchip implant   potential user   regression model   RFID   willingness  

摘要： Passive radio frequency identification microchip implants (MIs) have been the subject of public debate for nearly two decades, due to differing views on issues of privacy and impact on the human body, as well as actual successful applications in healthcare. Nonetheless, advances in technology imply that consumers may use MIs for identification, shopping, and other activities in the future. The purpose of this study was to identify the characteristics and habits of individuals who are more likely to use a MI in the near future. A cross-sectional study was conducted in five countries: Poland, Croatia, Slovenia, Ukraine, and the Russian Federation. Convenience sampling and an online questionnaire were used to collect data from 2037 respondents. Multiple regression analysis was used to test the research questions, and the results showed the predictors of willingness to use MIs. The potential MI user is male, has multiple social media profiles, and has a history of losing keys, wallets, or ID cards. He tends to use credit cards, contactless payments, and payment services when shopping. His willingness to use a MI decreases with age. Based on these findings, retailers and other service providers can adapt their processes to successfully support the future consumer with MI.

关键词： Automation technologies for smart cities   field robotics   infrastructure robotics   localization   robotics and automation in construction   robotics in hazardous fields  

摘要： Condition assessment of underground infrastructures such as pipe networks is crucial for aging cities around the globe. Recent development of robotic technologies facilitated application of them in condition assessment of pipe networks. However, there is still a gap for accurate localization technology in pipes due to complexity of the environment. In this letter, we propose a novel ultra-high frequency radio frequency identification (UHF-RFID) technology dual antenna system combined with Gaussian process and Particle filter algorithms to achieve millimeter level localization accuracy. The system is capable of achieving millimeter level accuracy over 50 m of length without an apparent estimation drift. The results were validated through experiments conducted using an extracted water pipe section.

关键词： Radio frequency identification (RFID)  

摘要： Parasitic elements have affirmative and destructive effects on antenna parameters such as impedance matching and bandwidth by inductive coupling. Extensive research has examined the application of parasitic elements in antennas with active amplifiers. This study uses frame-shaped parasitic elements to increase the reading range of passive Radio Frequency IDentification (RFID) tags with dual dipole antennas. First, an Impinj H47 RFID tag with a parasitic frame was modeled and optimized in Ansys High-Frequency Structure Simulator (HFSS) 2021 R2. Then, the test bench measured the tag reading range at the turning points of the simulation results. The laboratory measurements confirmed the simulation results, and we dramatically increased the reading range of passive RFID tags using parasitic elements. © 2022, The Authors. All rights reserved.