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关键词： Socio-technical systems analysis   RFID   Acute hospital  

摘要： The scale and pace of improvement in patient safety in healthcare has been unacceptably slow. A paucity of research into the application of systems-thinking concepts and a failure to appreciate health systems complexity are cited as barriers to sustainable health systems improvement. This study reports on a socio-technical systems analysis, called the CUBE, of the characteristics of a large acute teaching hospital's system for the transport of precious specimens, a system enabled by radio-frequency identification tracking technology. The CUBE proved itself to be an effective analytic tool. The analysis provided a constructive framework to link diverse data and documentation;explicitly inviting consideration of the roles and understandings of different stakeholders;as well as broader cultural factors that could influence current or future activity. The analysis also supported recommendations to improve and extend operations. This study supports the argument for systems understanding and systems thinking being at the core of new approaches to patient safety.

关键词： Dielectrics   Internet of Things   Radio frequency Identification   Performance verification   Simulation   Digital twin  

摘要： Radio frequency identification (RFID) is a cost-effective method to support the Industrial Internet of Things (IIoT) and is an enabling technology for Industry 5.0. The use of RFID is particularly suited to IIoT as it does not require a line of sight for communication and can be retroactively affixed to non-smart items. However, RFID communication is affected by the properties of the material the tag is affixed to, specifically the material permittivity. Metal is commonly present in smart factory environments and supply chains and impedes RFID communication. A suitable tag design is required to accommodate these challenges and ensure resilience for Industry 5.0 applications. The research presented in this paper has assessed the communication performance of RFID antenna designs with and without metal present beneath the tag. The RFID tag designs that performed reliably in the simulation were manufactured, and their read range was tested on materials of varying relative permittivity and thickness to represent MP and NMP scenarios. The results have verified the robustness of "Cyber" to "Physical" designs and provide recommendations to support practitioner IIoT tag selection.

关键词： bedload transport   large wood   linear mixed modelling   RFID   tracers  

摘要： Bedload transport is a fundamental process by which coarse sediment is transferred through landscapes by river networks and may be well described stochastically by distributions of grain step length and rest time obtained through tracer studies. To date, none of these published tracer studies have specifically investigated the influence of large wood in the river channel on sediment transport dynamics, limiting the applicability of stochastic sediment transport models in these settings. Large wood is a major component of many forested rivers and is increasing due to anthropogenic 'Natural Flood Management' (NFM) practices. This study aims to investigate and model the influence of large wood on grain-scale bedload transport. We tagged 957 cobble to pebble sized particles (D-50 = 73 mm) and 28 pieces of large wood (> 1 m in length) with radio frequency identification (RFID) tracers in an alpine mountain stream. We monitored the transport distance of tracers annually over 3 years, building distributions of tracer transport distances with which to compare with published distributions from wood free settings. We also applied linear mixed modelling (LMM), to tease out the influence of wood from other controls on likelihood of entrainment, deposition, and the transport distances of sediments. Tracer sediments accumulated both upstream and downstream of large wood pieces, with LMM analysis confirming a reduction in the probability of entrainment of tracers closer to wood in all 3 years. Upon remobilization, tracers entrained from positions closer to large wood had shorter subsequent transport distances in each year. In 2019, large wood also had a trapping effect, significantly reducing the transport distances of tracer particles entrained from upstream, that is forcing premature deposition of tracers. This study demonstrates the role of large wood in influencing bedload transport in alpine stream environments, with implications for both natural and anthropogenic addition of

关键词： Chipless tag   radio frequency identification (RFID)   radar cross-section (RCS)   Data dense  

摘要： One of the critical challenges in deploying radio frequency identification (RFID) is its cost of production. An approach to mitigate and be cost-effective is to design chipless, inexpensive electronic tags having a smaller size. Therefore, in this paper, a novel 22-bit passive chipless RFID tag with an enhanced radar cross-section (RCS) response is proposed. The tag design is loaded with 'U' and 'Inverted-U' shaped slots. The 'U' and 'Inverted-U' slots are etched on a metallic plate of size 39x40 mm(2 )for 22-bit data capacity and the tag can label 222 = 4,194,304 objects. The final tag design is optimized for Taconic TLX-0 and RT/duroid (R) 5880 substrates. Each 'U' and 'Inverted-U' shaped loaded slot are of different lengths and thus yield resonance at a particular frequency. The presence of a dip corresponds to the '1' bit and the '0' bit is achieved in the data word by shortening the particular slot. A detuning correction scheme is proposed by placing the slots in a special arrangement. By opting for this approach not only the tag exhibits an improved RCS response but also, the effect of shorted slot representing '0' on the neighboring dip is reduced. The proposed RFID tag can be deployed in tracking inventory, logistics, and low-cost business applications.

关键词： Vehicle localization   RFID   GPS-less   Chinese remainder theorem (CRT)   Levenherg-Marquardt (LM)  

摘要： The vehicle localization, which aims to identify a vehicle and then position the vehicle with a high precision, can be used to facilitate various applications and services in vehicular networks. Unfortunately, conventional localization systems, e.g., global positioning system (GPS), hardly meet the accuracy requirements especially in certain specific scenarios, such as tunnels. At the same time, Ultrahigh frequency (UHF) radio frequency identification (RFID) has become an efficient booster for internet of things (IoT) due to the desirable advantages, such as low cost, battery-free, and unique identification. In this paper, based on the UHF-RFID, we propose a novel real-time vehicle localization scheme in GPS-Less Environments. Considering the practical implementation of multiple RFID reader antennas on a vehicle is constrained, we adopt single antenna multi-frequency ranging scheme, in which the integer ambiguity problem is solved by the maximum-likelihood estimation (MLE)-based robust Chinese remainder theorem (CRT). With the reconstructed distances between the tags and the reader, the coordinates of the vehicle then can be calculated with the Levenberg-Marquardt (LM) algorithm. Furthermore, the computational complexities of the algorithms and the time consumption of the proposed scheme are analyzed. The experimental results demonstrate that the proposed scheme can track vehicle's location with error lower than 27 cm at the probability of 90%.

关键词： Chip-less   Microstrip antenna   Passive   RFID sensor  

摘要： In this paper, an ultra-high-speed and high-sensitivity temperature sensor based on a microwave band-stop filter modified with ZnO/MoS2/RGO nanocomposite materials is designed and manufactured. The amplitude of the temperature in the environment is determined in the frequency band from 2.73 GHz to 2.76 GHz. The optimized microstrip patch temperature sensor obtains a higher response and better quality factor, which improves the sensitivity of the temperature sensor. In order to study the performance of the temperature sensor, the sensor element modified with molybdenum disulfide (MoS2) sensitive material was placed in the radiosonde detection box, and the temperature level test was realized under the same humidity environment. The measurement results show that the amplitude change of the insertion loss from 0 ?C to 200 ?C shows a horizontal linear change. In addition, the temperature response recovery time is less than 10 s, and the temperature hysteresis is less than 0.34 ?C. This paper also discusses the mechanism of microstrip temperature-sensitive sensing from the perspective of molecular polarization. This provides a simple and easy method for realizing a high-sensitivity, fast-response microstrip temperature sensor.

关键词： antennas   differential RFID   impedance matching   Internet of Things   light sensing   microstrip antennas   multi-port RFID   patch antennas   RFID   wireless sensor node  

摘要： Radio frequency identification (RFID) represents an emerging platform for passive RF-powered wireless sensing. Differential Multi-port RFID systems are widely used to enable multiple independent measurands to be gathered, or to overcome channel variations. This paper presents a dual-port/dual-integrated circuit (IC) RFID sensing tag based on a shared aperture dual-polarized microstrip antenna. The tag can be loaded with different sensors where the received signal strength indicator (RSSI) of one IC is modulated using a sensor, and the other acts as a measurand-insensitive reference, for differential sensing. The 868 MHz tag maintains a minimum unloaded read range of 14 m insensitive to deployment on metals or lossy objects, which represents the longest reported range of a multi-port RFID sensing tag. The tag is loaded with a light-dependent resistor (LDR) to demonstrate its functionality as a battery-less wireless RFID light sensor. Following detailed RF characterization of the LDR, it is shown that the impedance, and consequently the RSSI, of the sensing tag are modulated by changing the light intensity, whereas the reference port maintains a mostly unchanged response for a correlated channel. The proposed tag shows the potential for channel variations-tolerant differential RFID sensing platforms based on polarization-diversity antennas.

关键词： Resonators   Radiofrequency identification   Backscatter   Bandwidth   Slot antennas   Resonant frequency   Radio frequency   Frequency response   radio frequency identification (RFID)   resonator   robustness   signal detection  

摘要： Frequency-coded chipless radio frequency identification (RFID) suffers from resonant frequency detuning caused by misaligned orientations. The literature has employed topological symmetry to prevent shape variations;however, this scheme is effective only for the orientation in roll and cannot address other rotational degrees of freedom, including pitch and yaw. This study takes the first step to cope with the orientation mismatch against arbitrary roll, pitch, and yaw angles. The proposed technique requires the design of tag and new reader architecture, eliminating complex signal processing. The tag comprises resonators with the pattern of a short dipole. Two reader antennas are placed orthogonally and fed with equal power, illuminating co-polarized electromagnetic waves toward the tag. Based on the Pythagorean trigonometric identity, the sum of the backscattering power is unvarying against the rotations in pitch or yaw. The proposed technique is experimentally validated using a 6.97 bit system. When orientation mismatch in yaw appears, the proposed scheme improves the read reliability from 54.3% to 93.5%. Moreover, when mismatch in both roll and yaw occurs, the reliability is improved from 43.8% to 91.8%. Practical aspects, including various detection zones and the loading effect, are also analyzed.

关键词： 3D localization   anti-collision   RFID   SAW   SDMA  

摘要： Surface acoustic wave (SAW) radio-frequency identification (RFID) has high potential for industrial applications, where automated identification and localization of assets represent the backbone of process controlling and logistics. However, in situations where multiple tags are simultaneously interrogated, the response patterns corresponding to the hard-coded reflectors are prone to overlap, preventing their association with the corresponding tags and, hence, the correct tag decoding. Identification and localization of multiple SAW RFID tags are addressed in this work under this challenging effect, known as collision, with a multi-antenna mobile robot-based synthetic aperture approach. Using the estimation of the spatial probability density functions of the SAW tag reflectors over a given interrogation aperture, the received impulse responses can be resolved in three dimensions and clustered with respect to their estimated locations. The performance of the proposed approach to associate and localize the signals from multiple tags was evaluated theoretically and experimentally.

关键词： breakage-triggered sensor   deformation sensor   rapid loss assessment   repair cost   repair time   RFID  

摘要： Structural components in a building are often enclosed by architectural coverings, which make it difficult to detect the damage levels of these components after earthquakes, because it is costly and time-consuming to remove the coverings. To rapidly detect the deformation conditions of the braces in a tension-only concentrically braced frame, a novel wireless radio frequency identification (RFID) based deformation sensor is presented in this paper. The battery-less sensor can be mounted on a steel plate brace, and when the largest elongation that the brace has ever experienced exceeds one of the preset deformation thresholds, the impedance of the RFID tag will change accordingly. In other words, the RFID tag can record the peak tensile deformation of the brace by changing its electrical state passively. In order to collect the deformation information of the key components of a structure after an earthquake, one only needs to carry an RFID interrogator/reader into the building and scan the RFID tags one by one in a contactless and non-line-of-sight way. Then, the damage levels are displayed in a building information modeling (BIM) software, and the collected information are further used to estimate the building losses automatically, which can help decision-makers decide whether to repair or to reconstruct the building. In this paper, a middleware was developed to enable the RFID reader to communicate with the BIM software. An experimental test was carried out to validate the sensor-reader-BIM system. A procedure for designing an optimal distribution of the deformation thresholds is also presented.