Radio frequency identification systems

Top PDF Radio frequency identification systems:

Antenna design solutions for radio frequency identification (RFID) tags based on metamaterial-inspired resonators and other resonant structures

Antenna design solutions for radio frequency identification (RFID) tags based on metamaterial-inspired resonators and other resonant structures

Unlike in the case of LF and HF systems, passive UHF tags typically use radiative coupling to communicate with the reader. The tags are usually provided with a planar dipole antenna, tuned to resonate with the RFID ASIC, which is able to produce a backscattered wave travelling back to the reader antenna. The nature of radiative coupling allows passive UHF-RFID systems to operate to large distances, in the order of several meters, with many tags reaching distances up to 15 m in optimal conditions. Moreover, passive UHF-RFID tags can be manufactured in thin and inexpensive labels (inlays), whose dimensions can be easily adjusted to fit with a large variety of small items. The modern communication protocols of UHF-RFID systems (e.g., EPC Gen2 standard) are provided with sophisticated anti-collision mechanisms, enabling very fast multiple readings of nearby tags, and support anti-counterfeiting cryptography, electronic article surveillance (EAS) functionality and privacy settings. However, due to the behavior of electromagnetic waves at higher frequencies, systems working at UHF are much more sensitive to the composition of the tagged item, and to environmental conditions, with respect to LF and HF systems. The performance of passive UHF-RFID tags is negatively affected by the presence of water, body-tissue and metals. Although many efforts have led to several tag designs optimized to operate in proximity of liquids, or to be attached on metallic surfaces, such solutions suffer from increased dimensions and cost with respect to the general-purpose tags. As a consequence, item level tagging of small metallic object by means of passive UHF-RFID tags is still challenging.
Mostrar más

167 Lee mas

METODOLOGÍA PARA LA IMPLEMENTACIÓN DE LA TECNOLOGÍA IDENTIFICACIÓN POR RADIOFRECUENCIA EN ENTORNOS INDUSTRIALES Y SANITARIOS EN COLOMBIA.

METODOLOGÍA PARA LA IMPLEMENTACIÓN DE LA TECNOLOGÍA IDENTIFICACIÓN POR RADIOFRECUENCIA EN ENTORNOS INDUSTRIALES Y SANITARIOS EN COLOMBIA.

The RFID (Radio Frequency Identification technology) is actually one of most used options to the identification of products because it allows to improve the process related with the management of product information in the supply chain and medical environments. Its features make RFID the best option in identification products process over other systems such as barcodes. However, according to the references consulted, there are few methodolo- gies that guide the user on how to implement this technology in the environments indicated. The present article proposes a methodology for the implementation of RFID, for which we realize a research where existing me- thodologies are discussed to finally propose a methodology that addresses technological and managerial aspects.
Mostrar más

7 Lee mas

Electronic identification of goats: comparison of different types of radio-frequency and visual devices

Electronic identification of goats: comparison of different types of radio-frequency and visual devices

Different studies have been carried out after the IDEA Project regarding the evaluation of different bolus types to suitably identify any goat breed, and under a variety of production systems. Capote et al. (2005) evaluated the performance of rumen boluses in 1,866 goats from several Spanish breeds for a period of 1 to 3 yr (Table 7.4). Two standard-sized boluses (22 mL) but differing in their weight (75 vs. 80 g) and SG (3.4 vs. 3.6) were used. Moreover, a new prototype of lighter (73 g) but denser (SG 3.9) bolus, with a more reduced o.d. (18.1 mm) for administration at lower body weight, was also evaluated. The authors confirmed that the heavier bolus improved average retention. The greatest losses were observed in 2 breeds (Palmera and Blanca de Rasquera) characterized by their rusticity and management in extensive conditions. Ethological particularities (frequent fights and jumping) of some extensively managed breeds were suggested to cause bolus displacement from the bottom of the reticulorumen and, thereby, to ease the occasional regurgitation (Capote et al., 2005). In addition, differences between herds were already pointed out.
Mostrar más

159 Lee mas

Using RFID to Enhance Security in Off Site Data Storage

Using RFID to Enhance Security in Off Site Data Storage

Abstract: Off-site data storage is one of the most widely used strategies in enterprises of all sizes to improve business continuity. In medium-to-large size enterprises, the off-site data storage processes are usually outsourced to specialized providers. However, outsourcing the storage of critical business information assets raises serious security considerations, some of which are usually either disregarded or incorrectly addressed by service providers. This article reviews these security considerations and presents a radio frequency identification (RFID)-based, off-site, data storage management system specifically designed to address security issues. The system relies on a set of security mechanisms or controls that are arranged in security layers or tiers to balance security requirements with usability and costs. The system has been successfully implemented, deployed and put into production. In addition, an experimental comparison with classical bar-code-based systems is provided, demonstrating the system’s benefits in terms of efficiency and failure prevention.
Mostrar más

19 Lee mas

Compensation of biased excitation effects for MLS-based nonlinear systems' identification

Compensation of biased excitation effects for MLS-based nonlinear systems' identification

The correction algorithm on the Volterra kernels is proposed based on the matrix form of the identification problem.. In Section 5 we assess the performance of the correction algorith[r]

19 Lee mas

Low frequency View of GW170817/GRB 170817A with the Giant Metrewave Radio Telescope

Low frequency View of GW170817/GRB 170817A with the Giant Metrewave Radio Telescope

In this paper, we present our continuing low-frequency observations of the radio transient using the Giant Metrewave Radio Telescope ( GMRT ) , located in Pune, India ( Section 2 ) , covering the time interval from 7 to 152  days after GW170817. The transient started to emerge at 1390 MHz frequencies ∼ 67  days after GW170817 and ∼ 40  days later also at 610  MHz. We augment our data set with archival X-ray and radio data to model the evolution in the framework of a structured GRB jet. To characterize the highly degenerate multi-dimensional parameter space of the model, we applied the Markov Chain Monte Carlo ( MCMC ) technique. All uncertainties in this paper are quoted at 1 σ con fi dence. We assume the distance to GW170817 to be 42.5 Mpc ( Hjorth et al. 2017 ) .
Mostrar más

10 Lee mas

Unsupervised Methods for Anomalies Detection through Intelligent Monitoring Systems

Unsupervised Methods for Anomalies Detection through Intelligent Monitoring Systems

The success of the majority of the monitoring and intelligent diagnosis systems relies on the use of the knowledge regarding existing domains (Knowledge Based Systems, or KBS) [1]. In this kind of domains, the main difficulty regarding failure and anomaly detection is how to make the expert knowledge explicit and how to model it. Knowledge modelling based on rules is one of the most common approaches [2]. Nevertheless, there exist domains where this approach can not be applied, due to either, non-existing previous expert knowledge or overly complex knowledge base management [3].
Mostrar más

8 Lee mas

A model for concepts extraction and context identification in knowledge based systems

A model for concepts extraction and context identification in knowledge based systems

Since the research is not finished yet, there are not so many results achieved up to now. But, the reducing of time to build a initial set of terms to analyze and build an ontology has already been evidenced. The main reason for it is that the simple structure of the model create documents that allow a fast recognizing of related words, creating a lot of candidate terms. Usage of weights also highlight the terms that happens with more frequency and which are normally related.

10 Lee mas

20 GHz arbitrary radio frequency waveform generator based on incoherent pulse shaping

20 GHz arbitrary radio frequency waveform generator based on incoherent pulse shaping

The generation of arbitrary electromagnetic signals with 1-50 GHz frequency content is a current challenge for purely electronic systems. The ability to generate such broad bandwidth signals can have a positive impact on high-speed wireless communication systems, as well as finding interesting applications in radar, remote sensing and electronic equipment test measurements [1]. Thanks to the inherent broadband nature of photonics, all-optical approaches for arbitrary waveform generators (AWGs) can achieve easily this frequency range [2-7]. Actually, the upper limit in terms of the analog radio-frequency (RF) bandwidth that can be achieved with photonic approaches is only limited by the optoelectronic (O/E) conversion bandwidth.
Mostrar más

6 Lee mas

Two step method for the deposition of AlN by radio frequency sputtering

Two step method for the deposition of AlN by radio frequency sputtering

The most common techniques used for AlN growth are metalorganic vapor phase epitaxy [9,10], hydride vapor phase epitaxy [11] and mo- lecular beam epitaxy [12,13], all requiring expensive technology and high substrate temperature. Radio frequency (RF) reactive magnetron sputtering represents an attractive low-cost technique to synthesize AlN fi lms, allowing deposition in a wide range of temperatures and in both rigid and fl exible substrates [refs. 14 – 16].

5 Lee mas

Monitoring cold chain logistics by means of RFID.

Monitoring cold chain logistics by means of RFID.

RFID was originally developed for short-range product identification, typically covering the 2 mm - 2 m read range and has been successfully applied to food logistics and supply chain management processes. However, recent developments in RFID hardware outfitted with sensors extend its range of application. Adding sensors to the same tags used to track items moving through the supply chain may also alert if they are not stored at the right temperature and predict the remaining shelf life. There are active and semi-passive tags that can measure temperature (Amador et al., 2008; Jedermann et al., 2009), humidity (Chang et al., 2007; Abad et al., 2009), shock/vibration (Todd et al., 2009) or light (Cho et al., 2005; Abad et al., 2009). Moreover, the last generation of Class 4 RFID tags can be configured in a mesh network. In this type of network, the tags can communicate each other to get to a reader circumventing environmental obstacles and extend the size of the system (Sarma & Engels, 2003).
Mostrar más

18 Lee mas

Methodologies and Programming Development of Applications on Modeling, Identification and Simulation

Methodologies and Programming Development of Applications on Modeling, Identification and Simulation

Abstract: Modeling, simulation and identification of prototypes allow people to make right predictions about the behavior of systems also finding mathematical expressions such as transfer functions, differential equations and state variables needed to control implementation without being necessary to implement real prototypes which allow to simulate in a similar environment as the one with perturbation or simply observe the dynamical response in normal conditions.This paper is focused on modeling various systems, using diverse modeling methods as direct, net method or variational, also the development of methodologies dedicated on study cases developing through which is implemented inverted kinematics, homogenous transformations, Newton-Euler method, Euler-Lagrange method and some other methods that makes it simple to run system simulations on Matlab.
Mostrar más

9 Lee mas

A new pump selection method for large-power PV irrigation systems at a variable frequency

A new pump selection method for large-power PV irrigation systems at a variable frequency

The impact of the way of selecting a pump on the performance of the system is shown for PV irrigation systems pumping into a water pool but it can also be applied to direct pumping to the irrigation network, which usually is carried out with spnnklers, pivots or drip systems. Direct pumping requires constant pressure and water flow which also means constant power. But the reality is that one single irrigation network includes several sectors with different valúes of constant pressure and water flow. So, different powers are needed but, in this case, it does not depend on the instantaneous PV-power available but on the sector being irrigated. In any case, the pump must also work at different frequencies and working-points.
Mostrar más

33 Lee mas

Measurements of time average series resonance effect in capacitively coupled radio frequency discharge plasma

Measurements of time average series resonance effect in capacitively coupled radio frequency discharge plasma

On the basis of discharge current and voltage measure- ments, we have experimentally studied the PSR effect. Anal- ysis of the Fourier transforms shows up to the tenth harmonics of the applied frequency. Measurements of the correction factor to the plasma resistance on the basis of ho- mogeneous discharge model shows significant reduction in the plasma resistance by factors of 2–8. In addition, these measurements show a considerable enhancement in RF cur- rent due to the PSR effect, which in-turn increases the Ohmic and stochastic heating. The enhancement of Ohmic and sto- chastic heating due to the PSR effect was found to increase significantly with decreasing pressure.
Mostrar más

7 Lee mas

Diagnostic of Capacitively Coupled Low Pressure Radio Frequency Plasma: An Approach through Electrical Discharge Characteristic

Diagnostic of Capacitively Coupled Low Pressure Radio Frequency Plasma: An Approach through Electrical Discharge Characteristic

characterization techniques are reported in recent literature to characterize the atmospheric pressure capacitively couple radio frequency (CCRF) plasma for different experimental parameters [11-14]. The electrical discharge characteristic can be also used to estimate the plasma parameters, which is simpler, easier, quicker and no additional equipment is required [11]. Li et al [11] estimated the electron density and electron temperature from the current-voltage and current-power characteristic of an atmospheric pressure CCRF plasma by using homogeneous discharge model. They have estimated the plasma density in mode of atmospheric pressure CCRF plasma. They assumed that the electron density n e is only proportional to the rms value of the applied
Mostrar más

5 Lee mas

Design of a drone based measurement system for GSM signals

Design of a drone based measurement system for GSM signals

It is important to talk about Software Defined Radio (SDR), which is a radio communication system where components that have been typically implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. A possible future development would be to use this system in instead of the GSM module. In addition to measure GSM signals, it would be possible to improve the reliability and accuracy of the experiments and to measure any radio frequency signal since this system’s bandwidth is totally reprogrammable.
Mostrar más

88 Lee mas

Distributed cognitive radio systems with temperature-interference constraints and overlay scheme

Distributed cognitive radio systems with temperature-interference constraints and overlay scheme

In the paper, we analyze the properties of the game within the theory of variational inequalities, and provide an algorithm that converges to one Nash Equilibrium of the game.. Finall[r]

5 Lee mas

Analysis of resource allocation in wireless mobile systems with orthogonal frequency division multiplexing

Analysis of resource allocation in wireless mobile systems with orthogonal frequency division multiplexing

Using the Equation 3.10 we can calculate the the total offered traffic to center area of the cell 1, now if it is considered that new service 1 request arrival rate is aproximately 6 as [r]

70 Lee mas

Constraining the redshift evolution of first radio sources in RCS1 galaxy clusters

Constraining the redshift evolution of first radio sources in RCS1 galaxy clusters

Studies of X-ray AGNs in clusters typically define a cluster galaxy AGN fraction as their observable quantity. They typically exclude the BCGs from this AGN fraction to avoid possible contamination from cluster cool cores (e.g., Martini et al. 2006; Arnold et al. 2009). Of the different results for radio sources in clusters that we have presented, the quantity that we measure that compares most directly to this AGN fraction is the number of radio-loud non-BCG cluster members per unit mass (as shown in Figure 8). We do see evidence at the 3σ level that this quantity evolves with redshift, although the redshift range we are probing is also not as wide as that probed by Martini et al. (2009). They measure the fraction of galaxies in clusters that are X- ray AGNs using two different redshift binning schemes with two and three redshift bins, and restricting their sample to the two highest redshift bins of the three bin scheme brings it into better agreement with our redshift distribution (these bins have 0.3 < z < 0.6 and z > 0.6). The mean X-ray AGN fractions they measure for these bins are 0.0031 and 0.0147, so that the increase is about a factor of 4.7. Such a large increase is unlikely in the radio source population in our sample, for which we see an increase by about a factor of two for the richest clusters, which show the most evidence for evolution. So, even if qualitatively there may be some similar evolution in the radio population as the X-ray population, it appears to be less strong.
Mostrar más

10 Lee mas

Efficient localization methods for wireless sensor networks based on received signal strength = Metodos de localizacion eficiente para redes de sensores basados en la medida de la potencia de señal recibida

Efficient localization methods for wireless sensor networks based on received signal strength = Metodos de localizacion eficiente para redes de sensores basados en la medida de la potencia de señal recibida

posi- tioning error of 2 m. While RADAR and WILMA are deterministic positioning systems, probabilistic models can also be used to estimate the location of the user. Probabilistic ap- proaches, as the ones proposed in Moreno (2008); Castro and Muntz (2000); Castro et al. (2001); Roos et al. (2002) or in the Horus system (Youssef and Agrawala, 2004, 2008), store the signal strength distribution from the access points and use probabilistic algorithms to estimate the most likely position of the user. The COMPASS system (King et al., 2006) is another example of RSS-based localization using a probabilistic fingerprinting approach with a WiFi infrastructure. This system takes also advantage of digital compasses to con- sider the orientation of the user and provide more accurate position estimations (about 1.65 m), but only considers tracking a single user. Other RSS-based localization systems supported by WiFi networks provide similar localization accuracy of a few meters (Battiti et al., 2002; Saha et al., 2003; Ladd et al., 2002, 2004; Haeberlen et al., 2004; Siddiqi et al., 2003; Kontkanen et al., 2004; Xiang et al., 2004; Collado, 2007).
Mostrar más

238 Lee mas

Show all 6311 documents...