RF and THz Identification Using a New Generation of Chipless RFID Tags

This article presents two chipless RFID approaches where data are reading using electromagnetic waves and where the medium encoding the data is completely passive. The former approach rests on the use of RF waves (more precisely the ultra-wide band UWB). The tags developed for this application are comparable with very specific, planar, conductive, radar targets where the relation between the tag geometry and its electromagnetic signature is perfectly known and is used to encode the data. The principle of operation as well as the realization process of the RF tags presented in this paper is similar to those already reported in the literature. However, contrary to the majority of chipless RFID tags, these labels do not present an antenna function dissociated from the circuit part where the data are stored. Here, functions such as the receiver, the treatment and the emitter of the signal are closely dependent. The data storage capacity of the RF chipless tags is proportional to of the used frequency bandwidth. As radio spectrum is regulated, the number of possible encoding bits is thus strongly limited with this technology. This is the reason why we introduce a new family of tags radically different from the preceding one, where data is encoded in volume thanks to a multilayer structure operating in the THz domain. These two approaches although different are complementary and allow to increase significantly the data storage capacity of the chipless tags. Simulation and experimental results are reported in this paper for both configurations. We demonstrate a coding capacity of 3.3 bit/cm2 for RFID chipless tags and a potential 10 bits coding capacity in the THz domain

Scherbius wind farm based fuzzy SSSC

The wind is a clean, free, and readily available renewable energy source, it is cost-effective in several regions, it is a domestic source of energy and it is a sustainable source of energy. The SSSC system is a FACTS voltage compensator, it is inserted in series with the electrical transmission line through a coupling transformer, its role is to inject a voltage which allows to influence the active power transmitted. The goal of this paper is to examine the effect of using a wind farm SSSC to improve flexibility of a multi-machine perturbed network

Novel DTC induction machine drive improvement using controlled rectifier for DC voltage tuning

The application of the direct torque control strategy for induction machine drives is mainly characterized by torque and flux distortions caused by voltage vector limitation. The goal of this paper is to perform the conventional DTC induction machine drives and reduce ripples of both flux and torque response. The proposed contribution is based on the control of the DC output side of the rectifier feeding the voltage source inverter by means of PI controller in order to adapt the voltage vector used in typical DTC switching table. Mathematic models are built using MATLAB Simulink and programming environment; the simulation results show the difference between the proposed method and classical DTC

Robust optmized control of multi levels STATCOM

Reactive power compensation is an essential part of a power system and the static synchronous compensator (STATCOM) plays an important role in controlling the reactive power flow over the transmission line. The basic building block of the STATCOM is a voltage source inverter (VSI) that generates a synchronous sinusoidal voltage and because of the high MVA ratings, it would be expensive to provide independent, equal, regulated dc voltage sources to power the multilevel converters which are presently proposed for STATCOMs. Dc voltage sources can be derived from the dc link capacitances which are charged by the rectified ac power. In this paper a new stronger control combined of nonlinear control based Lyapunov’s theorem and Ant Colony Algorithm (ACA) to maintain stability of multilevel STATCOM and the utility

Contribution à l’analyse de phénomène du fluage des matériaux composites

La présente thèse doctorale est une contribution à l’analyse du phénomène du fluage des matériaux composites à base polyamide 6 renforcés par des particules de verre recyclé. Le travail effectué comprend la préparation du matériau composite et étudier l’effet de la taille des particules de verre sur ses propriétés viscoélastiques. Du fait que la prédiction du comportement de fluage nécessite une longue période d’essai, une méthode accélérée à court terme basée sur le principe de superposition et la technique des iso-contraintes étagées a été adoptée. Durant le processus de traitement des données, Une comparaison a été faite entre trois fonctions d’ajustement et d’extrapolation (polynomiale, puissance et exponentielle) afin de déterminer leur impact sur la précision des résultats. Une technique d’optimisation performante a été utilisée pour exploiter une large gamme des données expérimentales et surmonter par conséquent les problèmes de convergences. Une routine numérique a été également développée afin de faciliter la construction des courbes maitresses de fluage et une bonne corrélation entre les fonctions d’ajustement exponentielle et puissance a été obtenue

Information Systems Governance as a System of Rules: Hierarchical and Heterarchical Implementation

Information Systems Governance (ISG) can be defined as a set of rules allowing executives and skateholders to determine how they will decide on the Information System management. The first objective of this paper is to propose a set of meta-rules addressing different aspects of ISG, which are instantiated in each company setting. The second objective is to propose two constrasting models of ISG, which instantiate differently the set of rules. Conventional view of ISG includes hierarchical and centralized control with little flexibility to support rapidly changing organizations. Heterarchical forms are more and more frequently observed in ISG practices (agility, transversality, decentralization...). However, if uncontrolled, heterarchy can lead to the emergence of anarchic phenomena, such as instability, increased conflicts, and waste of resources. Approaching ISG through rules implementation can help controlling heterarchical forms. In the first part of our paper, we describe an ISG as a set of the rules, based on Elinor Ostrom’s work and her IAD (Institutional Analysis and Development) framework. In a second part, we develop each type of rule first according to a hierarchical view, then to a heterarchical one. Beyond theoretical contribution, the proposed set of rules can help CIOs involved in improving ISG. It can also be used to make an organizational analysis of heterarchical practices of a company’s ISG

On the use of the stepped isostress method in the prediction of creep behavior of polyamide 6

The stepped isostress method (SSM) is an advanced technique which allows the prediction of the long-term behavior and enables the construction of creep master curves of materials with short-term experimental tests. However, the performance of this method is highly dependent on the numerical model and the time spent in data processing. In this paper, the effect of the extrapolation techniques on the creep curves trend is investigated using the SSM data of Polyamide test. Three extrapolation functions are used to offset the delay of the stress history: polynomial, power and exponential functions. Furthermore, a numerical routine is developed during the last step of the SSM, where the shift factors are computed taking into account the rescaling and the dwell times of each level of stresses. The processing of the SSM raw data has revealed that the rescaling parameters are the most determining factors to reach an accurate long-term creep curves. The rescaling process has shown an appropriate time, whether achieved by the exponential or power functions. Larger shift factors for exponential functions are assessed and therefore a long period of creep master curve was obtained

Impact of sensorless neural direct torque control in a fuel cell traction system

Due to the reliability and relatively low cost and modest maintenance requirement of the induction machine make it one of the most widely used machines in industrial applications. The speed control is one of many problems in the traction system, researchers went to new paths instead the classical controllers as PI controller, they integrated the artificial intelligent for its yield. The classical DTC is a method of speed control by using speed sensor and PI controller, it achieves a decoupled control of the electromagnetic torque and the stator flux in the stationary frame, besides, the use of speed sensors has several drawbacks such as the fragility and the high cost, for this reason, the specialists went to propose an estimators as Kalman filter. The fuel cell is a new renewable energy, it has many applications in the traction systems as train, bus. This paper presents an improved control using DTC by integrate the neural network strategy without use speed sensor (sensorless control) to reduce overtaking and current ripple and static error in the system because the PI controller has some problems like this; and reduce the cost with use a renewable energy as fuel cell