Bibliographies thématiques / ELECTRICALS SIGNALS

Littérature scientifique sur le sujet « ELECTRICALS SIGNALS »

Auteur : Grafiati
Publié le 11 septembre 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Sommaire

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « ELECTRICALS SIGNALS ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "ELECTRICALS SIGNALS"

1

Klyuchko, O. M., et P. V. Beloshitsky. « Biosensor concept and data input to biomedical infornation systems ». Medical Informatics and Engineering, no 3 (10 juin 2021) : 51–69. http://dx.doi.org/10.11603/mie.1996-1960.2020.3.11698.

Texte intégral
Résumé :
Background. In present publication we generalized and analyzed deeply the experience of some biosensors studying in biophysical experiments with aim to incorporate them further to electronic information systems. Output biosensor electrical signals were input ones to electronic information system making their connection into joined bioinformation system. Materials and methods. Methods of comparative analysis of the characteristics of input and output electrical information signals of biosensor were applied; its physical and mathematical models were developed. For biosensor properties studies the methods of transmembrane electric currents recording in voltage-clamp mode as well as patch-clamp on hippocampal neuronal membranes were used. Results. Biosensor concept and their general characteristic were given, corresponding prototypes were observed. The physical model of biosensor was developed and some test results of this device were suggested. The biosensor was examined as abstraction in consistent unity of its functions: signal receiver — filter — analyzer — encoder/decoder. A brief mathematical description of biosensor functioning was given as well as corresponding algorithm. As a result of performed works the possibilities of this biosensor incorporation to bioinformation electronic systems were substantiated and the example of such system «EcoIS» was observed. Conclusion. In conclusion following results of the works were summarized. The detailed description of technical devices — biosensors as elements of biomedical information systems were done as well as analysis of electrical information signals at output of biosensor, its ability to encode information and detailed analysis of the possibility to incorporate this biotechnical device into electronic information systems due to biosensor output electricals signals.
Styles APA, Harvard, Vancouver, ISO, etc.
2

He, Fei, Jiabei Shen, Zhi Tang, Xiaomeiao Qi et Haoran Li. « Influencing Factors of Rock Electrical Signal Analysis Based on Artificial Intelligence ». Mobile Information Systems 2021 (21 octobre 2021) : 1–9. http://dx.doi.org/10.1155/2021/1165686.

Texte intégral
Résumé :
To get the generation mechanism and influence factors of the coal-rock electrical signal, it provides a reference for coal-rock electric signal prediction and dynamic disaster. Firstly, the law of charge energy relation is deduced by using the universal or functional relation of Newton’s law, and then coal and rock mass with different properties such as coal, granite, and sandstone are selected. Using the established test system, the influence of coal and rock electric signal is analyzed from the coal-rock temperature, coal and rock properties, coal-rock friction, coal-rock loading speed, and coal-rock load size. The chief results can be summarized as follows: in the process of coal-rock rising with temperature, the change rule of electrical signals can be divided into three stages according to the strength of electrical signals generated. The amplitudes of electrical signals generated by uniaxial compression of coal-rock mass with different properties are obviously different. Electrical signals can be generated during the friction of coal and rock. With the augment of loading speed, the electrical semaphore generated when the coal rock is about to fracture tends to be enhanced. The size of the electrical signal is not proportional to the size of the load, but the electrical signal is greatest when the rupture is imminent. The analysis of the influence factors of coal and rock electrical signals can provide a reference for the research on the generation mechanism of coal-rock electrical signals.
Styles APA, Harvard, Vancouver, ISO, etc.
3

Cai, Weiming, et Qingke Qi. « Study on Electrophysiological Signal Monitoring of Plant under Stress Based on Integrated Op-Amps and Patch Electrode ». Journal of Electrical and Computer Engineering 2017 (2017) : 1–7. http://dx.doi.org/10.1155/2017/4182546.

Texte intégral
Résumé :
Electrophysiological signal in plant is a weak electrical signal, which can fluctuate with the change of environment. An amplification detection system was designed for plant electrical signal acquisition by using integrated op-amps (CA3140, AD620, and INA118), patch electrode, data acquisition card (NI USB-6008), computer, and shielded box. Plant electrical signals were also studied under pressure and flooding stress. The amplification detection system can make nondestructive acquisition for Aquatic Scindapsus and Guaibcn with high precision, high sensitivity, low power consumption, high common mode rejection ratio, and working frequency bandwidth. Stress experiments were conducted through the system; results show that electrical signals were produced in the leaf of Aquatic Scindapsus under the stress of pressure. Electrical signals in the up-leaf surface of Aquatic Scindapsus were stronger than the down-leaf surface. Electrical signals produced in the leaf of Guaibcn were getting stronger when suffering flooding stress. The more the flooding stress was severe, the faster the electrical signal changed, the longer the time required for returning to a stable state was, and the greater the electrical signal got at the stable state was.
Styles APA, Harvard, Vancouver, ISO, etc.
4

Zhang, Hong, Xinxin Lu et Xiuye Yin. « Reverse Synchronous Transmission of Electrical Signals Based on Parallel Injection and Series Pickup ». Traitement du Signal 37, no 4 (10 octobre 2020) : 655–60. http://dx.doi.org/10.18280/ts.370415.

Texte intégral
Résumé :
To eliminate the interference with the transmission of electrical signals, this paper puts forward a reverse synchronous transmission (RST) control method based on parallel injection and series pickup. Firstly, the synchronous transmission mechanism of electrical signals was analyzed, followed by the design of the framework and workflow of signal transmission. Next, an RST channel model was established for electrical signals, and the transmission parameters were configured based on the transmission properties of these signals. Through alternative current (AC) impedance analysis, the Laplace transform was performed on the transmission loop to increase the voltage of the transmission channel, and to elevate the signal-to-noise ratio (SNR) of the voltage across the resistor. Finally, the voltage comparator was adopted to obtain the digital information of the baseband signal, and the power signal was transmitted to the RST channel, completing the RST control of electrical signals. The experimental results show that the transmission speed of the system was 0.7488, and the reverse transmission of electrical signals was only delayed by 5ms, when the intensity of electromagnetic radiation was 2.0μT. Through parallel injection and series pickup, the proposed system can effectively realize the RST of electrical signals, without changing the topology of the transmission system.
Styles APA, Harvard, Vancouver, ISO, etc.
5

Carneiro, Mirella, Victor Oliveira, Fernanda Oliveira, Marco Teixeira et Milena Pinto. « Simulation Analysis of Signal Conditioning Circuits for Plants’ Electrical Signals ». Technologies 10, no 6 (25 novembre 2022) : 121. http://dx.doi.org/10.3390/technologies10060121.

Texte intégral
Résumé :
Electrical signals are generated and transmitted through plants in response to stimuli caused by external environment factors, such as touching, luminosity, and leaf burning. By analyzing a specific plant’s electrical responses, it is possible to interpret the impact of external aspects in the plasma membrane potential and, thus, determine the cause of the electrical signal. Moreover, these signals permit the whole plant structure to be informed almost instantaneously. This work presents a brief discussion of plants electrophysiology theory and low-cost signal conditioning circuits, which are necessary for the acquisition of plants’ electrical signals. Two signal conditioning circuits, which must be chosen depending on the signal to be measured, are explained in detail and electrical simulation results, performed in OrCAD Capture Software are presented. Furthermore, Monte Carlo simulations were performed to evaluate the impact of components variations on the accuracy and efficiency of the signal conditioning circuits. Those simulations showed that, even after possible component variations, the filters’ cut-off frequencies had at most 4% variation from the mean.
Styles APA, Harvard, Vancouver, ISO, etc.
6

Saatci, Ertugrul, et Esra Saatci. « Multifractal Behaviour of Respiratory Signals ». Electrica 20, no 2 (15 juin 2020) : 182–88. http://dx.doi.org/10.5152/electrica.2020.20011.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Li, Chang Cheng, Lai Wu Yin, Dong Chen et Shu Jie Xu. « Lossless Compression of Weak Electrical Signal of Ginseng Molecule Based on Discrete Wavelet Transform and Siesta Program ». Advanced Materials Research 986-987 (juillet 2014) : 1950–53. http://dx.doi.org/10.4028/www.scientific.net/amr.986-987.1950.

Texte intégral
Résumé :
This paper proposed the electron density of time series by using the Siesta software to calculate the weak electrical signals of ginseng molecule, combining with the lifting scheme DWT to remove ginseng molecular spatial redundancy. For the acquisition and identification of weak electrical signals of ginseng molecule in physical environment , based on the analysis of collection and identification’s principles, the noise coefficient is removed to reconstruct the signal and retain the useful signal components through applying the multi-decomposition of DWT transform to divide weak electrical signals of ginseng molecule into wavelet coefficients of different scales. The experimental results show that the multi-resolution analysis of DWT transform is performed for the weak electrical signal of ginseng molecule with different rhythms and different frequency ranges, and the weak electrical signal size of ginseng molecule before and after compression, the percentage of high frequency coefficients set to zero, and the average energy percentage after compression are, respectively, increased to 77.73%, 46.88%, and 99.99%. This algorithm operates fast enough to ease hardware implementation, providing an effective method for lossless compression of the weak electrical signals of ginseng molecule.
Styles APA, Harvard, Vancouver, ISO, etc.
8

Wang, Hanbo. « Compressed Sensing : Theory and Applications ». Journal of Physics : Conference Series 2419, no 1 (1 janvier 2023) : 012042. http://dx.doi.org/10.1088/1742-6596/2419/1/012042.

Texte intégral
Résumé :
Abstract Compressed sensing is a new technique for solving underdetermined linear systems. Because of its good performance, it has been widely used in academia. It is applied in electrical engineering to recover sparse signals, especially in signal processing. This technique exploits the signal’s sparse nature, allowing the original signals to recover from fewer samples. This paper discusses the fundamentals of compressed sensing theory, the research progress in compressed sensing signal processing, and the applications of compressed sensing theory in nuclear magnetic resonance imaging and seismic exploration acquisition. Compressed sensing allows for the digitization of analogue data with inexpensive sensors and lowers the associated costs of processing, storage, and transmission. Behind its sophisticated mathematical expression, compressed sensing theory contains a subtle idea. Compressed sensing is a novel theory that is an ideal complement and improvement to conventional signal processing. It is a theory with a high vitality level, and its research outcomes may substantially influence signal processing and other fields.
Styles APA, Harvard, Vancouver, ISO, etc.
9

Zhuang, Qiu Hui, Guo Jun Liu, Xiu Hua Fu et San Qiang Wang. « Brain Electrical Signal Digital Processing System Design ». Applied Mechanics and Materials 278-280 (janvier 2013) : 958–61. http://dx.doi.org/10.4028/www.scientific.net/amm.278-280.958.

Texte intégral
Résumé :
Through the amplification system to extract the brain electrical signal, although already can be displayed, but is not clear; in addition, the analog signal into the computer to carry on the analysis, also must pass to convert analog signals to digital signals (A/D converter).Therefore the need for further use of digital processing, this paper adopts the digital way, on brain electrical analog signal digital filter, through the 40Hz low-pass filter and 50Hz filter, get clear, stable signal, to achieve the design objective.
Styles APA, Harvard, Vancouver, ISO, etc.
10

Shi, Qiong, JingCi Zhou, JianPing Xiang et YangChun Shi. « Research on multi-fault diagnosis method and test platform of main transmission Machinery of wind Turbine based on electrical signal ». Journal of Physics : Conference Series 2268, no 1 (1 mai 2022) : 012011. http://dx.doi.org/10.1088/1742-6596/2268/1/012011.

Texte intégral
Résumé :
Abstract An optimised design was carried out based on the original semi-physical simulation system for the main drive chain of a wind turbine. The input of upper computer simulating wind condition, the safety control of electrical signal and vibration signal acquisition module, relay and AC contactor and dual motor control were added. Simultaneously, the simulation schemes of some common faults on the main drive of wind turbines were also designed in order to perform the experimental simulation of the single fault and multi fault. The primary purpose of simulation is to use practical approaches(such as FFT,EMD)to analyze the changes of the fault signals based on the collected electrical signals, and to determine whether there is a fault through comparison and theoretical analysis. In addition, it aimed for verifying the feasibility of electrical signals under multi-fault conditions, and discussing advantages of electrical signals over vibration signals.
Styles APA, Harvard, Vancouver, ISO, etc.
Plus de sources

Thèses sur le sujet "ELECTRICALS SIGNALS"

1

Andrikogiannopoulos, Nikolas I. « RF phase modulation of optical signals and optical/electrical signal processing ». Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/42930.

Texte intégral
Résumé :
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 125-127).
Analog RF phase modulation of optical signals has been a topic of interest for many years, mainly focusing on Intensity Modulation Direct Detection (IMDD). The virtues of coherent detection combined with the advantages of Frequency Modulation, however, have not been explored thoroughly. By employing Frequency Modulation Coherent Detection (FMCD), the wide optical transmission bandwidth of optical fiber can be traded for higher signal-to-noise performance. In this thesis, we derive the FM gain over AM modulation -- the maximum achievable signal-to-noise ratio (by spreading the signal's spectrum) for specific carrier-to-noise ratio. We then employ FMCD for a scheme of remote antennas for which we use optical components and subsystem to perform signal processing such as nulling of interfering signals. The performance of optical processing on different modulation schemes are compared, and some important conclusions are reported relating to the use of conventional FMCD, FMCD with optical discriminator (FMCD O-D), and IMDD. Specifically, the superiority of conventional FMCD is shown; and, on the other hand, the inferiority of FMCD O-D is shown (same performance as IMDD) because of the use of an O-D. Finally, the remote antenna scheme is generalized for N antennas and N users.
by Nikolas I. Andrikogiannopoulos.
S.M.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Ghaderi, Foad. « Signal processing techniques for extracting signals with periodic structure : applications to biomedical signals ». Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/55183/.

Texte intégral
Résumé :
In this dissertation some advanced methods for extracting sources from single and multichannel data are developed and utilized in biomedical applications. It is assumed that the sources of interest have periodic structure and therefore, the periodicity is exploited in various forms. The proposed methods can even be used for the cases where the signals have hidden periodicities, i.e., the periodic behaviour is not detectable from their time representation or even Fourier transform of the signal. For the case of single channel recordings a method based on singular spectrum anal ysis (SSA) of the signal is proposed. The proposed method is utilized in localizing heart sounds in respiratory signals, which is an essential pre-processing step in most of the heart sound cancellation methods. Artificially mixed and real respiratory signals are used for evaluating the method. It is shown that the performance of the proposed method is superior to those of the other methods in terms of false detection. More over, the execution time is significantly lower than that of the method ranked second in performance. For multichannel data, the problem is tackled using two approaches. First, it is assumed that the sources are periodic and the statistical characteristics of periodic sources are exploited in developing a method to effectively choose the appropriate delays in which the diagonalization takes place. In the second approach it is assumed that the sources of interest are cyclostationary. Necessary and sufficient conditions for extractability of the sources are mathematically proved and the extraction algorithms are proposed. Ballistocardiogram (BCG) artifact is considered as the sum of a number of independent cyclostationary components having the same cycle frequency. The proposed method, called cyclostationary source extraction (CSE), is able to extract these components without much destructive effect on the background electroencephalogram (EEG)
Styles APA, Harvard, Vancouver, ISO, etc.
3

Gartheeban, Ganeshapillai. « Methods to improve the signal quality of corrupted multi-parameter physiological signals ». Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65969.

Texte intégral
Résumé :
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2011.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 121-125).
A modern Intensive Care Unit (ICU) has automated analysis systems that depend on continuous uninterrupted real-time monitoring of physiological signals such as Electrocardiogram (ECG), Arterial Blood Pressure (ABP), and the Photo Plethysmogram (PPG). Unfortunately, these signals are often corrupted by noise, artifacts, and missing data, which can result in a high incidence of false alarms. We present a novel approach to improve the Signal Quality of a multi-parameter physiological signal by identifying the corrupted regions in the signal, and reconstructing them using the information available in correlated signals. The method is specifically designed to preserve the clinically most signicant aspects of the signals. We use template matching to jointly segment the multi-parameter signal, morphological dissimilarity to estimate the quality of the signal segment, similarity search to nd the closest match from a database of templates, and time-warping to reconstruct the corrupted segment using the matching template. Experiments carried out on the MIT-BIH Arrhythmia Database, a multi-parameter ECG database with many clinically signicant arrhythmias, demonstrate the effectiveness of the method. Our method improved the classification accuracy of the beat type by more than 700% on the signal corrupted with white Gaussian noise, and increased the similarity to the original signal, as measured by the normalized residual distance, by more than 250%. When the method was applied to the multi-parameter physiological signal data from Cinc Challenge 2010 database at Physionet.org, our method improved the classification accuracy of beat type by more than 33 times on a signal corrupted with white Gaussian noise, and increased the similarity to the original signal by more than 280%.
by Gartheeban Ganeshapillai.
S.M.
Styles APA, Harvard, Vancouver, ISO, etc.
4

Nguyen, Thien-Minh. « Contribution to the analysis and understanting of electrical-grid signals with signal processing and machine learning techniques ». Thesis, Mulhouse, 2017. http://www.theses.fr/2017MULH9234/document.

Texte intégral
Résumé :
Ce travail de thèse propose des approches d’identification et de reconnaissance des harmoniques de courant qui sont basées sur des stratégies d’apprentissage automatique. Les approches proposées s’appliquent directement dans les dispositifs d’amélioration de la qualité de l’énergie électrique.Des structures neuronales complètes, dotées de capacités d’apprentissage automatique, ont été développées pour identifier les composantes harmoniques d’un signal sinusoïdal au sens large et plus spécifiquement d’un courant alternatif perturbé par des charges non linéaires. L’identification des harmoniques a été réalisée avec des réseaux de neurones de type Multi–Layer Perceptron (MLP). Plusieurs schémas d’identification ont été développés, ils sont basés sur un réseau MLP composé de neurones linéaire ou sur plusieurs réseaux MLP avec des apprentissages spécifiques. Les harmoniques d’un signal perturbé sont identifiées avec leur amplitude et leur phase, elles peuvent servir à générer des courants de compensation pour améliorer la forme du courant électrique. D’autres approches neuronales a été développées pour reconnaître les charges. Elles consistent en des réseaux MLP ou SVM (Support Vector Machine) et fonctionnent en tant que classificateurs. Leur apprentissage permet à partir des harmoniques de courant de reconnaître le type de charge non linéaire qui génère des perturbations dans le réseau électrique. Toutes les approches d’identification et de reconnaissance des harmoniques ont été validées par des tests de simulation à l’aide des données expérimentales. Des comparaisons avec d’autres méthodes ont démontré des performances supérieures et une meilleure robustesse
This thesis proposes identifying approaches and recognition of current harmonics that are based on machine learning strategies. The approaches are applied directly in the quality improvement devices of electric energy and in energy management solutions. Complete neural structures, equipped with automatic learning capabilities have been developed to identify the harmonic components of a sinusoidal signal at large and more specifically an AC disturbed by non–linear loads. The harmonic identification is performed with multilayer perceptron neural networks (MLP). Several identification schemes have been developed. They are based on a MLP neural network composed of linear or multiple MLP networks with specific learning. Harmonics of a disturbed signal are identified with their amplitude and phases. They can be used to generate compensation currents fed back into the network to improve the waveform of the electric current. Neural approaches were developed to distinguish and to recognize the types of harmonics and is nonlinear load types that are at the origin. They consist of MLP or SVM (Support Vector Machine) acting as classifier that learns the harmonic profile of several types of predetermined signals and representative of non–linear loads. They entry are the parameters of current harmonics of the current wave. Learning can recognize the type of nonlinear load that generates disturbances in the power network. All harmonics identification and recognition approaches have been validated by simulation tests or using experimental data. The comparisons with other methods have demonstrated superior characteristics in terms of performance and robustness
Styles APA, Harvard, Vancouver, ISO, etc.
5

Thomas, Gregoire R. « Agonist : induced electrical signals in the intact lens ». Thesis, University of East Anglia, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338296.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Hassana, Ramesh Rakesh Kashyap. « Transform Domain Acquisition of Spread Spectrum Signals in a Low Signal to Noise Ratio Environment ». Ohio University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1289579500.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Kershaw, Robert Andrew. « Retrieved voluntary electromyogram signals for functional electrical stimulation control ». Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295098.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
8

Bortnik, Bartosz Jan. « Photonic generation, transmission, and detection of high-speed electrical signals ». Diss., Restricted to subscribing institutions, 2007. http://proquest.umi.com/pqdweb?did=1459913961&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Masmoudi, Mohamed Lamine. « Détection d'un défaut localisé dans un multiplicateur d'éolienne : approche par analyse des grandeurs électromécaniques ». Thesis, La Rochelle, 2015. http://www.theses.fr/2015LAROS001.

Texte intégral
Résumé :
Le travail présenté dans ce mémoire a été effectué dans le cadre du projet FEDER ”Maintenance prédictive des éoliennes et maîtrise des impacts environnementaux”. Un des objectifs du projet a été de développer, dans le Poitou-Charentes, des compétences dans le domaine de l’éolien en lien avec les activités des laboratoires LIAS et LaSIE. Pour le LIAS, il a été décidé de lancer une nouvelle activité de recherche sur le diagnostic de défauts mécaniques. Le cadre du projet concernant l’éolien, les défauts localisés dans les multiplicateurs ont été privilégiés. Par ailleurs, nous avons restreint l’étude au régime stationnaire afin de simplifier l’apprentissage des différents phénomènes mis en jeu et des techniques de traitement du signal utilisées. Dans une première partie, nous avons étudié les signatures de défaut sur les signaux vibratoires. Cette phase a été facilitée par l’utilisation des données expérimentales mise à disposition par le Bearing Data Center de la Case Western Reserve - University de Cleveland. Parmi les méthodes de traitement de signal utilisées, nous avons opté pour l’analyse d’enveloppe mise en oeuvre dans les techniques de type Time Synchronous Analysis (TSA). A cette occasion, nous avons défini une procédure complète de détection de défaut que nous avons conservée tout au long de cette étude en appliquant une technique d’identification de type PNL qui nous a permis d’obtenir des résultats comparables à des méthodes haute résolution de type ESPRIT. Par la suite, nous nous sommes recentrés sur l’application éolienne en réalisant un banc d’essai original permettant d’émuler un défaut au niveau de l’accouplement de deux machines électriques. L’idée principale a été de recenser l’ensemble des signaux exploitables dans le cadre de la détection du défaut émulé et de fournir une classification entre les courants électriques, le couple mécanique et la vitesse des machines. Par ailleurs, un comparatif entre signaux mesurés et signaux estimés a été présenté. Il en ressort qu’il est possible d’obtenir un signal observé plus riche que la mesure directe en terme de composantes spectrales liées au défaut. Cette amélioration est rendue possible par une synthèse adéquate des gains d’observation qui a été obtenue après linéarisation de l’observateur étudié. En marge de l’application éolienne, le cas d’un moteur commandé vectoriellement a été abordé. L’idée a été d’exploiter les performances de la boucle de vitesse afin d’amplifier les composantes recherchées dans les courants électriques. L’ensemble de ces pistes de recherches a été testé en simulation et expérimentalement
The work presented in this thesis was carried out under the FEDER project ”Maintenance prédictive des éoliennes et maîtrise des impacts environnementaux”. One of the project objectives was to develop, in Poitou-Charentes, expertise in the field of wind power in connection with the activities of LIAS and LaSIE laboratories. For LIAS, it was decided to launch a new research activity on the diagnosis of mechanical faults. The localized defects in gearbox were privileged. Furthermore, we restricted the study to the stationary system to simplify the learning of different phenomena involved and signal processing techniques. In the first part, we studied the fault signatures on the vibration signals. This phase was facilitated by the use of experimental data available from the Bearing Data Center of the Case Western Reserve - Cleveland University. Among the signal processing methods, we opted for envelope analysis implemented in the Synchronous Time Averaging (TSA). On this occasion, we defined a comprehensive fault detection procedure that we have maintained throughout this study by applying a NLP identification technique where we obtained similar results compared to high-resolution methods as ESPRIT. There after, we refocused on wind power applications by making an original test bench capable of emulating a fault in the coupling of two electrical machines. The main idea was to identify all usable signals in the context of emulated fault detection and to provide a classification between electric currents, mechanical torque and speed of the machines. Moreover, a comparison between measured signals and estimated ones was discussed. It shows that it is possible to get an observed signal richer than direct signal measurement in terms of spectral components related to the defect. This improvement is made possible by an appropriate synthesis of gains observer which was obtained after linearization of the studied observer. In the margin of wind application, the case of a motor controlled by vector was also discussed. The idea was to exploit the speed loop performance to amplify the fault components in electrical currents. All these researches have been tested in simulation and experimentally
Styles APA, Harvard, Vancouver, ISO, etc.
10

Naidoo, Thoneshan. « Signal and image processing for electrical resistance tomography ». Master's thesis, University of Cape Town, 2002. http://hdl.handle.net/11427/5140.

Texte intégral
Résumé :
Bibliography: leaves 139-150.
Electrical Resistance Tomography (ERT) is in essence an imaging technique.In ERT current is injected into and removed from a vessel via paired electrodes. The resulting voltage measurements are captured between the remaining electrode pairs. The principle behind ERT is to map these boundary voltages into a conductivity distribution that represents the domain of the vessel. The author has coded a versatile reconstruction algorithm based on the Newton-Raphson algorithm. The knowledge gained by implementing the algorithm is documented in this thesis. The literature covers the basic aspects of two-dimensional and three-dimensional ERT. It is hoped that this thesis will create a greater interest in ERT at the University of Cape Town (UCT) and also act as a building block for further developments. The thesis starts by presenting the basic concepts of ERT such as the underlying equations, the various boundary measurement strategies and a global perspective of ERT. The nature of this thesis is on software reconstruction and in so doing information on the incorporation of the Finite Element Method in ERT is provided. The thesis goes on to provide information about the reconstruction algorithms, which incorporate regularization. A novel aspect of this thesis involves the calibration and pre-processing of boundary voltages. These concepts were conceptualised and developed during formal communications with Dr. Wilkinson (2002) and Randal (2002). The calibration schemes try to eliminate the potential errors that can arise inthe captured data thus allowing for a clearer image to be reconstructed, Electrical Resistance Tomography. This thesis further develops the idea of parallelizing the Newton-Raphson algorithm to increase the speed of the algorithm. Various schemes on how this parallelization is achievable are put forward.
Styles APA, Harvard, Vancouver, ISO, etc.
Plus de sources

Livres sur le sujet "ELECTRICALS SIGNALS"

1

Devasahayam, Suresh R. Signals and Systems in Biomedical Engineering : Signal Processing and Physiological Systems Modeling. 2e éd. Boston, MA : Springer US, 2013.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
2

Circuits, signals, and devices. Harlow, Essex, England : Longman Scientific & Technical, 1988.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Webster, John G. Electrical measurement, signal processing, and displays. Boca Raton : CRC Press, 2003.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

1932-, Webster John G., dir. Electrical measurement, signal processing, and displays. Boca Raton : CRC Press, 2004.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Peterson, Andrew F. Transient signals on transmission lines : An introduction to non-ideal effects and signal integrity issues in electrical systems. San Rafael, Calif. (1537 Fourth Street, San Rafael, CA 94901 USA) : Morgan & Claypool Publishers, 2009.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Kudeki, Erhan. Analog signals and systems. Upper Saddle River, N.J : Pearson Prentice Hall, 2009.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Kudeki, Erhan. Analog signals and systems. Upper Saddle River, N.J : Pearson Prentice Hall, 2009.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
8

S, Gevins A., et Rémond Antoine, dir. Methods of analysis of brain electrical and magnetic signals. Amsterdam : Elsevier, 1987.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Pradhan, Gayadhar, Stella Morris et Niranjan Nayak, dir. Advances in Electrical Control and Signal Systems. Singapore : Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5262-5.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
10

Electrical cables for power and signal transmission. New York : John Wiley, 2000.

Trouver le texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
Plus de sources

Chapitres de livres sur le sujet "ELECTRICALS SIGNALS"

1

Keller, Reto B. « Time-Domain and Frequency-Domain ». Dans Design for Electromagnetic Compatibility--In a Nutshell, 41–48. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-14186-7_5.

Texte intégral
Résumé :
AbstractThis chapter introduces the transformation from time-domain to frequency-domain and vice versa. Electrical signals—periodic or nonperiodic—can be measured in the time-domain (e.g., with an oscilloscope) or in the frequency-domain (e.g., with a spectrum analyzer). This means that an electrical signal can be described either in the time- or frequency-domain. The time-domain representation helps you to determine the signal integrity (ringing, reflection). In contrast, the frequency-domain representation helps you to determine at which frequencies a signal potentially leads to radiated emissions.As an EMC design engineer and troubleshooter, it is crucial to understand the dependencies and relationship between the time-domain and the frequency-domain.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Weik, Martin H. « electrical signal ». Dans Computer Science and Communications Dictionary, 486. Boston, MA : Springer US, 2000. http://dx.doi.org/10.1007/1-4020-0613-6_5879.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Christopoulos, Christos. « Electrical Signals and Circuits ». Dans Principles and Techniques of Electromagnetic Compatibility, 55–77. 3e éd. Boca Raton : CRC Press, 2022. http://dx.doi.org/10.1201/9781003310983-5.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
4

Kories, Ralf, et Heinz Schmidt-Walter. « Signals and Systems ». Dans Electrical Engineering, 208–60. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-642-55629-6_6.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
5

Bartiromo, Rosario, et Mario De Vincenzi. « Measurement of Alternating Electrical Signals ». Dans Undergraduate Lecture Notes in Physics, 163–80. Cham : Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-31102-9_7.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
6

Başar, Erol. « Electrical Signals from the Brain ». Dans Springer Series in Synergetics, 21–38. Berlin, Heidelberg : Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-72192-2_3.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Eccles, William. « Processing Signals ». Dans Pragmatic Electrical Engineering : Systems and Instruments, 81–103. Cham : Springer International Publishing, 2011. http://dx.doi.org/10.1007/978-3-031-79837-5_4.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
8

Ahirwal, Mitul Kumar, Anil Kumar et Girish Kumar Singh. « Biomedical Signals ». Dans SpringerBriefs in Electrical and Computer Engineering, 1–20. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-67098-6_1.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
9

Bhooshan, Sunil. « Analysis of Signals ». Dans Lecture Notes in Electrical Engineering, 15–107. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-4277-7_2.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
10

Meena, Hemant Kumar, Ramnivas Sharma, Abhinav Tailor, Harshil Verma et Rajveer Saini. « Detection of Epilepsy Using Graph Signal Processing of EEG Signals with Three Features ». Dans Lecture Notes in Electrical Engineering, 569–78. Singapore : Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-1520-8_46.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "ELECTRICALS SIGNALS"

1

Gookin, D. M., et M. H. Berry. « Integrated optical differential amplifier with large dynamic range for gigahertz bandwidth electrical signals ». Dans Integrated Photonics Research. Washington, D.C. : Optica Publishing Group, 1991. http://dx.doi.org/10.1364/ipr.1991.tud10.

Texte intégral
Résumé :
Some optoelectronic differential amplifiers have been developed for gigahertz signal bandwidths.1–3 These previous optoelectronic approaches were based on a balanced heterodyne receiver design. The electrical-to-optical and optical-to-electrical conversion was used to electrically isolate the two input signals. The actual signal subtraction was done electronically. In the optoelectronic differential amplifier we present here we do the signal subtraction while still in the optical domain. We have eliminated the need for a balancing network, increased the usable bandwidth, developed a variable gain mechanism, and improved the linear and spurious free dynamic range over previous opto-electronic differential amplifiers.
Styles APA, Harvard, Vancouver, ISO, etc.
2

Koo, Kil Mo, Kwang Il Ahan, Yong Mann Song, Joon Eon Yang et Eung Seok Park. « Response Analysis From Transient Signal for Variation of R-C Passive Elements Under High Temperature Accident Condition in NPPs ». Dans 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48356.

Texte intégral
Résumé :
The electrical signal could be checked whether it lies within its expected electrical range when it is doubtful condition. In the case of an abnormal transient signal from an instrument under a severe accident condition, it needs to define a signal validation to operate at control room in NPPs. Diagnostics and analysis for some abnormal transient signals have been also performed through the important equivalent circuits modeling for the passive elements under the conditions. Even under such a condition, the electrical signal should be within its expected range so that some mitigation actions can be taken through it in control room. Whereas, in case that an abnormal signal is expected from an instrument, such a signal should be refined through a signal validation process so that the refined signal could be available in the control room. For some abnormal signals expected under severe accident conditions, to date, diagnostics and response signals have been evaluated with an equivalent circuit model to real instruments, which is regarded as the best way. Main objective of this paper is to introduce a program designed to implement a diagnostic and response analysis for an equivalent circuit modeling. The program links a signal analysis tool code to an abnormal signal simulation engine not only as a one body order system, but also as a part of functions of a PC-based ASSA (abnormal signal simulation analysis) module developed to obtain a varying range of the elements in high temperature conditions. As a result, a special function for abnormal signal patterns can be obtained through the program, which in turn makes it possible to analyze the abnormal output signals through a response characteristic of a 4∼20mA circuit model and a range of the elements changing with temperature under an accident condition.
Styles APA, Harvard, Vancouver, ISO, etc.
3

Rajkumar, N., J. N. McMullin, B. P. Keyworth et R. I. MacDonald. « 3 X 3 Optoelectronic Cross-Bar Switch Using Vertical Cavity Surface Emitting Laser Arrays ». Dans Diffractive Optics and Micro-Optics. Washington, D.C. : Optica Publishing Group, 1996. http://dx.doi.org/10.1364/domo.1996.dmd.4.

Texte intégral
Résumé :
In an electronic space division switch matrix, the system performance at high frequencies is subject to degradation because of crosstalk due to electromagnetic coupling in adjacent signal paths. A substantial improvement in performance can be obtained if the incoming signals were optical and the outgoing electrical with optical detectors acting as the cross points[1,2]. As the incoming paths are optical, a great degree of immunity to crosstalk can be gained, and the crosstalk that may arise in the outgoing electrical lines could be reduced by proper shielding as the adjacent conductor lines are no longer electrically connected. Such switching matrices may also be applied in high speed analog and digital signal processing applications [3,4]. The signal distribution in optoelectronic switches has been done in the past using 1:N multimode fibre splitters and butt-coupling the fibres to the MSM detectors by prealigning the fibres in etched silicon V-groove arrays. Two drawbacks of the fibre distribution method are that it is very fragile and handling large number of fibres is difficult and time-consuming. Alternative approaches are the use of integrated waveguide devices for power division or free space interconnect. A 3X3 free space switch prototype using three discrete lasers has been previously reported [5]. In this paper a modified version using vertical cavity surface emitting lasers (VCSEL’s) driven by electrical inputs is described.
Styles APA, Harvard, Vancouver, ISO, etc.
4

Bekele, Dagmawi, Hitesh Sahoo, Deming Kong, Michael Galili, Kresten Yvind, Leif Katsuo Oxenløwe et Jesper Mørk. « Direct-detection receiver for QPSK-modulated signals ». Dans Optical Fiber Communication Conference. Washington, D.C. : Optica Publishing Group, 2023. http://dx.doi.org/10.1364/ofc.2023.m3z.17.

Texte intégral
Résumé :
We demonstrate a novel optical receiver for direct-detection of QPSK signals using microring-based photonic integrated circuit. The QPSK signal is converted into a PAM7 electrical signal, and demodulated without the need for a local oscillator.
Styles APA, Harvard, Vancouver, ISO, etc.
5

Kalbfleisch, Paul, Svenja Horn et Monika Ivantysynova. « Cyclostationary Analysis of Measured Pump Acoustic and Vibration Signals ». Dans BATH/ASME 2018 Symposium on Fluid Power and Motion Control. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/fpmc2018-8899.

Texte intégral
Résumé :
The stationary signal assumption is convenient as its signal processing methods are the minimum effort required to characterize periodic signals and therefore the most common. However, signals from rotating machines have been found to naturally be characterized as cyclostationary. The existent of natural phenomenon such as, shaft imbalances, turbulent fluid flows, friction, combustion forces, and torsional vibrations create modulation effects, that can be seen in the measured signals. These observed modulations in pump noise and vibration signals are synonymous to amplitude modulations (AM), frequency modulations (FM), and potentially phase modulations in electrical systems. Having this knowledge, the fluid power noise, vibration, and harshness (NVH) researchers can draw from an enormous amount of progress made in the modern telecommunication signal processing methods of cyclostationary signals. This article introduces the basic concepts of cyclostationary signals, some of their signal processing techniques, and a simple example of analysis for a positive displacement machine through the cyclostationary paradigm.
Styles APA, Harvard, Vancouver, ISO, etc.
6

McConaghy, Chuck. « An Optically Strobed Sample and Hold Circuit* ». Dans Picosecond Electronics and Optoelectronics. Washington, D.C. : Optica Publishing Group, 1987. http://dx.doi.org/10.1364/peo.1987.wb3.

Texte intégral
Résumé :
Radiation damaged photoconductors have been shown to be useful devices for sampling repetitve electrical signals with time resolution to less than a PicoSecond1,2. However, the sampling of low repetition rate or single shot events with these photoconductors has not been possible due to the need for lock in detection methods to observe the sampled signal. In this paper, a radiation damaged photoconductor serves as the sampling element in a sample and hold circuit. It has been possible to sample single shot electrical signals with about a 10 picosecond aperture time. Once sampled the signal can be held for about 1 microsecond by an on-chip holding amplifier.
Styles APA, Harvard, Vancouver, ISO, etc.
7

Liu, Yanming, Mike Grove et Paul R. Prucnal. « Multiple quantum well waveguide modulator for fiber-optic interconnects ». Dans OSA Annual Meeting. Washington, D.C. : Optica Publishing Group, 1991. http://dx.doi.org/10.1364/oam.1991.wd4.

Texte intégral
Résumé :
It is well-known that electrical I/O bottlenecks in integrated circuits can be remedied with optical interconnects. An optical interconnect link requires a transmitter to convert intrachip electrical signals into optical signals suitable for fiber-optic interchip communication, and a receiver to reconvert optical signals at the fiber output into electrical signals on the chip. We consider an approach using an off-chip laser as an optical power supply, connected via optical fiber to an on-chip electrooptic modulator that imprints the distributed optical power with the desired information. Optical fiber carries the modulated optical signal to a receiver, which may be on a different chip or board. The signal-to-noise ratio (SNR) at the receiver output is 10logSNR = P-L(λ)+ 10log[αβ(ΔV,λ], where P is the laser output power in dBm, the optical loss L in the link is a function of wavelength λ, the parameter α is directly proportional to the detector responsivity and inversely proportional to the bit-rate and receiver noise-equivalent-power, and the modulation depth β is a function of λ as well as the voltage-swing ΔV applied to the on-chip modulator.
Styles APA, Harvard, Vancouver, ISO, etc.
8

Takahashi, H., S. Aoshima et Y. Tsuchiya. « Improvement of Space Dependent Sensitivity and Absolute Voltage Measurement in Non-Contact Picosecond Electro-Optic Sampling ». Dans Picosecond Electronics and Optoelectronics. Washington, D.C. : Optica Publishing Group, 1991. http://dx.doi.org/10.1364/peo.1991.fb5.

Texte intégral
Résumé :
While the need for measurement systems capable of characterizing ultrafast electrical signals has grown according to the increasing speed of electrical devices, Valdmanis et al. have, for the first time, achieved time-resolved ultrafast photo-detection with accuracy of less than 1ps by electro-optic sampling using a CPM dye laser1)2). Nowadays the electro-optic sampling method has opened a new area as a measurement method of ultrafast electrical signals3)-7).
Styles APA, Harvard, Vancouver, ISO, etc.
9

Choi, Hyeon Y., Takehiro Tsuritani et Itsuro Morita. « Generation Method of Optical 64QAM Signal Using Electrical Binary Drive Signals ». Dans Asia Communications and Photonics Conference. Washington, D.C. : OSA, 2012. http://dx.doi.org/10.1364/acp.2012.as1g.6.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
10

Choi, Hyeon Yeong, Takehiro Tsuritani et Itsuro Morita. « Generation Method of Optical 64QAM Signal Using Electrical Binary Drive Signals ». Dans Asia Communications and Photonics Conference. Washington, D.C. : OSA, 2012. http://dx.doi.org/10.1364/acpc.2012.as1g.6.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "ELECTRICALS SIGNALS"

1

Gotten, Jr, et William M. Robotic Control Using Muscular and Neural Electrical Signals. Fort Belvoir, VA : Defense Technical Information Center, mai 1994. http://dx.doi.org/10.21236/ada284908.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
2

Fayette, Daniel F., et Nancy A. Koziarz. Electrical Characterization of Signal Processing Microcircuit. Fort Belvoir, VA : Defense Technical Information Center, avril 1989. http://dx.doi.org/10.21236/ada209078.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
3

Research, Gratis. Green Light : A New Preventive Therapy for Migraine. Gratis Research, novembre 2020. http://dx.doi.org/10.47496/gr.blog.03.

Texte intégral
Résumé :
Manipulating the ability of green light to create the least amount of electrical signals in retina and brain cortex, green light therapy offers an excellent therapeutic role in reducing migraine pain and improves the quality of life
Styles APA, Harvard, Vancouver, ISO, etc.
4

Jones, Robert M., Alison K. Thurston, Robyn A. Barbato et Eftihia V. Barnes. Evaluating the Conductive Properties of Melanin-Producing Fungus, Curvularia lunata, after Copper Doping. Engineer Research and Development Center (U.S.), novembre 2020. http://dx.doi.org/10.21079/11681/38641.

Texte intégral
Résumé :
Melanins are pigmented biomacromolecules found throughout all domains of life. Of melanins’ many unique properties, their malleable electrically conductive properties and their ability to chelate could allow them to serve as material for bioelectronics. Studies have shown that sheets or pellets of melanin conduct low levels of electricity; however, electrical conductance of melanin within a cellular context has not been thoroughly investigated. In addition, given the chelating properties of melanin, it is possible that introducing traditionally con-ductive metal ions could improve the conductivity. Therefore, this study investigated the conductive properties of melanized cells and how metal ions change these. We measured the con-ductivity of pulverized Curvularia lunata, a melanized filamentous fungi, with and without the addition of copper ions. We then com-pared the conductivity measurements of the fungus to chemically synthesized, commercially bought melanin. Our data showed that the conductivity of the melanized fungal biomass was an order of magnitude higher when grown in the presence of copper. However, it was two orders of magnitude less than that of synthetic melanin. Interestingly, conductance was measurable despite additional constituents in the pellet that may inhibit conductivity. Therefore, these data show promising results for using melanized cells to carry electrical signals.
Styles APA, Harvard, Vancouver, ISO, etc.
5

CORSCADDENorscadden, Louise, et Arpaporn Sutipatanasomboon. The Definite Guide to Flow Cytometry for Scientists. ConductScience, décembre 2022. http://dx.doi.org/10.55157/cs20221213.

Texte intégral
Résumé :
Flow cytometry is an analytical technique that examines cells suspended in fluids. It uses a built-in laser beam to illuminate individual cells as the fluid passes through. The illumination causes fluorescence and scattered lights, which are emitted and reflected from the examining cell. These lights are split and filtered onto detectors and converted into electrical signals.
Styles APA, Harvard, Vancouver, ISO, etc.
6

Amman, Mark, Marc Bergevin, Yuen-Dat Chan, Jason A. Detwiler, Brian Fujikawa, Kevin T. Lesko, Paul N. Luke et al. Electrical Signal Path Study and Component Assay for the MAJORANA N-Type Segmented Contact Detector. Office of Scientific and Technical Information (OSTI), février 2009. http://dx.doi.org/10.2172/1000958.

Texte intégral
Styles APA, Harvard, Vancouver, ISO, etc.
7

Simms, Janet, Benjamin Breland et William Doll. Geophysical investigation to assess condition of grouted scour hole : Old River Control Complex—Low Sill Concordia Parish, Louisiana. Engineer Research and Development Center (U.S.), septembre 2021. http://dx.doi.org/10.21079/11681/41863.

Texte intégral
Résumé :
Geophysical surveys, both land-based and water-borne, were conducted at the Old River Control Complex‒Low Sill, Concordia Parish, LA. The purpose of the surveys was to assess the condition of the grout within the scour region resulting from the 1973 flood event, including identification of potential voids within the grout. Information from the ground studies will also be used for calibration of subsequent marine geophysical data and used in stability analysis studies. The water-borne survey consisted of towed low frequency (16-80 MHz) ground penetrating radar (GPR), whereas the land-based surveys used electrical resistivity and seismic refraction. The GPR survey was conducted in the Old River Channel on the upstream side of the Low Sill structure. The high electrical conductivity of the water (~50 mS/m) precluded penetration of the GPR signal; thus, no useful data were obtained. The land-based surveys were performed on both northeast and southeast sides of the Low Sill structure. Both resistivity and seismic surveys identify a layered subsurface stratigraphy that corresponds, in general, with available borehole data and constructed geologic profiles. In addition, an anomalous area on the southeast side was identified that warrants future investigation and monitoring.
Styles APA, Harvard, Vancouver, ISO, etc.
8

Weinschenk, Craig, Daniel Madrzykowski et Paul Courtney. Impact of Flashover Fire Conditions on Exposed Energized Electrical Cords and Cables. UL Firefighter Safety Research Institute, octobre 2019. http://dx.doi.org/10.54206/102376/hdmn5904.

Texte intégral
Résumé :
A set of experiments was conducted to expose different types of energized electrical cords for lamps, office equipment, and appliances to a developing room fire exposure. All of the cords were positioned on the floor and arranged in a manner to receive a similar thermal exposure. Six types of cords commonly used as power supply cords, extension cords, and as part of residential electrical wiring systems were chosen for the experiments. The non-metallic sheathed cables (NMB) typically found in residential electrical branch wiring were included to provide a link to previous research. The basic test design was to expose the six different types of cords, on the floor of a compartment to a growing fire to determine the conditions under which the cord would trip the circuit breaker and/or undergo an arc fault. All of the cords would be energized and installed on a non-combustible surface. Six cord types (18-2 SPT1, 16-3 SJTW, 12-2 NM-B, 12-3 NM-B, 18-3 SVT, 18-2 NISPT-2) and three types of circuit protection (Molded case circuit breaker (MCCB), combination Arc-fault circuit interrupter (AFCI), Ground-fault circuit interrupter (GFCI)) were exposed to six room-scale fires. The circuit protection was remote from the thermal exposure. The six room fires consisted of three replicate fires with two sofas as the main fuel source, two replicate fires with one sofa as the main fuel source and one fire with two sofas and MDF paneling on three walls in the room. Each fuel package was sufficient to support flashover conditions in the room and as a result, the impact on the cords and circuit protection was not significantly different. The average peak heat release rate of the sofa fueled compartment fires with gypsum board ceiling and walls was 6.8 MW. The addition of vinyl covered MDF wall paneling on three of the compartment walls increased the peak heat release rate to 12 MW, although most of the increased energy release occurred outside of the compartment opening. In each experiment during post flashover exposure, the insulation on the cords ignited and burned through, exposing bare conductor. During this period the circuits faulted. The circuit protection devices are not designed to provide thermal protection, and, thus, were installed remote from the fire. The devices operated as designed in all experiments. All of the circuit faults resulted in either a magnetic trip of the conventional circuit breaker or a ground-fault trip in the GFCI or AFCI capable circuit protection devices. Though not required by UL 1699, Standard for Safety for Arc-Fault Circuit-Interrupters as the solution for detection methodology, the AFCIs used had differential current detection. Examination of signal data showed that the only cord types that tripped with a fault to ground were the insulated conductors in non-metallic sheathed cables (12-2 NM-B and 12-3 NM-B). This was expected due to the bare grounding conductor present. Assessments of both the thermal exposure and physical damage to the cords did not reveal any correlation between the thermal exposure, cord damage, and trip type.
Styles APA, Harvard, Vancouver, ISO, etc.
9

Bruce et Fiore. L51629 Users Manual-Field Validation of the Low-Frequency Eddy Current Instrument-Software Listings. Chantilly, Virginia : Pipeline Research Council International, Inc. (PRCI), octobre 1990. http://dx.doi.org/10.55274/r0010602.

Texte intégral
Résumé :
When an eddy current probe is placed near a conductive material, the alternating magnetic field from the probe causes electrical currents to flow in the material. These currents have associated with them their own magnetic field, which opposes the original magnetic field from the coil. The result is that the impedance of the probe is greatly reduced by the presence of the conducting material. If the conductor is also magnetic, as is normal steel, the situation is similar though slightly more complicated. Here, the impedance of the probe may be either increased or decreased depending on the permeability of the material and the frequency of the alternating field. Anything that affects the flow of current in the conductive material will also affect the impedance of the eddy current probe. For example, the electrical currents cannot flow through a crack but must flow around it. The alteration in the currents also changes the magnetic field produced by the currents and, consequently, the impedance of the probe. Normally, the impedance change caused by a defect is much smaller than that caused by the presence of the material in the first place, and measuring this small change requires a bridge circuit much like the balanced bridge used with strain gauges. The balanced bridge allows one to amplify the small changes in impedance caused by defects in the presence of the much larger change caused by the presence of the conductive and magnetic pipeline steel. The LFEC instrument is constructed using an� IBM-AT compatible portable computer. Inside the PAC-386 are two plug-in circuit cards that turn the PAC-386 into an eddy current instrument. The first, also commercially available, is a Spectrum DSP56000 digital signal processing card, while the second is a specially-built interface card for the eddy current probe. The PAC-386 is a standard MS-DOS machine and will operate most MS-DOS software. In the discussion below, it is assumed that the user is familiar with the MSDOS operating system.
Styles APA, Harvard, Vancouver, ISO, etc.
Vous pouvez également être intéressé par les bibliographies sur le sujet « ELECTRICALS SIGNALS » pour d’autres types de sources :
Articles de revues Thèses Livres
Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!

Vers la bibliographie