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Littérature scientifique sur le sujet « Modélisation du signal »

Auteur : Grafiati
Publié le 22 avril 2023

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Articles de revues sur le sujet "Modélisation du signal"

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Glockner, Ste´phane, Jean-Paul Caltagirone et Paul Morel. « Mode´lisation d'e´coulements dans des espaces urbains ». International Journal of Thermal Sciences 38, no 8 (septembre 1999) : 703–11. http://dx.doi.org/10.1016/s1290-0729(99)80063-5.

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Borghi,, R., M. Champion,, JL Torero, et A. Atreya,. « Mode´lisation et The´orie des Flammes. Modeling and Theory of Flames. (French) ». Applied Mechanics Reviews 54, no 5 (1 septembre 2001) : B93—B94. http://dx.doi.org/10.1115/1.1399681.

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Mei, Fei, Zhihong Man et Xinghuo Yu. « Sliding mode control signal analysis ». IFAC Proceedings Volumes 32, no 2 (juillet 1999) : 4118–22. http://dx.doi.org/10.1016/s1474-6670(17)56702-6.

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Männama, V. « CURRENT-MODE SIGNAL PROCESSING CIRCUITS ». Proceedings of the Estonian Academy of Sciences. Engineering 3, no 4 (1997) : 237. http://dx.doi.org/10.3176/eng.1997.4.01.

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Chen, Walter Y., et Richard A. Haddad. « Dual mode adaptive signal processing ». Computers & ; Electrical Engineering 18, no 3-4 (mai 1992) : 261–75. http://dx.doi.org/10.1016/0045-7906(92)90019-a.

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Gallard, Herve´, Joseph de Laat et Bernard Legube. « Influence du pH sur la vitesse d'oxydation de compose´s organiques par FeII/H2O2. Me´canismes re´actionnels et mode´lisation ». New Journal of Chemistry 22, no 3 (1998) : 263–68. http://dx.doi.org/10.1039/a708335a.

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Ladinig, Olivia, et David Huron. « Minor mode cuing : Do composers signal minor mode sooner than major mode ? » Psychomusicology : Music, Mind, and Brain 23, no 2 (2013) : 117–22. http://dx.doi.org/10.1037/pmu0000007.

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Reau, J. M., J. Senegas et M. El Omari. « Corre´lations entre proprie´te´se´lectriques et structurales de solutions solides de type fluorinea`exce`s d'anions : Essai de mode`lisation ». Journal of Solid State Chemistry 84, no 2 (février 1990) : 253–70. http://dx.doi.org/10.1016/0022-4596(90)90324-q.

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Mardiono, Djoko Anwar, Gunawan Toto Hadiyanto et Intan Kumala Sari. « Penggunaan Common-Mode Filter dan Differential-Mode Filter Pada EMI Driver Lampu LED ». Zona Teknik : Jurnal Ilmiah 15, no 2 (29 décembre 2021) : 1. http://dx.doi.org/10.37776/zt.v15i2.811.

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Power Energy efficiency for public application commonly used driver IC that operate by (Pulse Width Modulation) PWM, The effect of this implementation will generate EMI (Electromagnetic Interference) that can make radio signal distortion or other electronic distortion in the around device area. The action to reduce the signal distortions shall use Filter implementation in the electronic device circuit. The filter to reduce signal distortion are power line filter or ferrite beads filter. Power line filter used for reduce and to filtering noise signal from Power line source from PLN power line or from power line distribution Conduction emission., The ferrite beads filter implementation for noise reduction or filtering from Source power supply to load. Implement of both filters at the circuit diagram will impact to reduce noise signal that make distortion to the signal source.
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Toumazou, Chris, John Lidgey et Brett Wilson. « Editorial. Current-mode analogue signal processing ». IEE Proceedings G Circuits, Devices and Systems 137, no 2 (1990) : 61. http://dx.doi.org/10.1049/ip-g-2.1990.0013.

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Thèses sur le sujet "Modélisation du signal"

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Ridley, Raymond Bryan. « A new small-signal model for current-mode control ». access full-text online access from Digital dissertation consortium, 1990. http://libweb.cityu.edu.hk/cgi-bin/er/db/ddcdiss.pl?9116643.

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Ridley, Raymond B. « A new small-signal model for current-mode control ». Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-07282008-135124/.

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Taillefer, Christopher. « Analog-to-digital conversion via time-mode signal processing ». Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18669.

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Conventional voltage-mode analog-to-digital converters use voltage amplifiers, voltage comparators, and switch capacitor networks to perform their signal processing. When compared to digital circuitry, these analog circuit blocks consume significant power, occupy large silicon areas, and operate at relatively slow data processing speeds. A signal processing methodology is proposed that performs analog-to-digital conversion on voltage signals while implementing all the circuits in a digital CMOS logic style. This methodology, called time-mode signal processing, uses time-difference variables as an intermediate signal between the input voltage and digital output. The resulting silicon devices offer very compact, low power, high-speed, and robust analog-to-digital converter alternatives. There are five main analog-to-digital converter topologies: flash, successiveapproximation, pipeline, delta-sigma, and integrating converters. Each converter topology is presented in the context of the time-mode signal processing methodology. The circuits that implement each time-mode data converter are described and when appropriate system-level, transistor-level, and experimental results are revealed. Three integrated circuits (IC) were fabricated in a 0.18-µm CMOS technology to demonstrate the feasibility of the time-mode ADC methodology. The first IC implemented the time-mode comparator and a time-mode flash ADC. The timemode delta-sigma ADC design was demonstrated in the second IC. Two circuits were implemented in the third IC: a differential-input time-mode delta-sigma ADC and a cyclic (or algorithmic) ADC.
Les convertisseurs conventionnels pour changer la tension analogique à une tension numérique emploient les amplificateurs de tension, les comparateurs de tension, et les résaux de condensateur sélectionable pour acquir leur traitement de signal. En comparaison le circuit des modules analogues vis-à-vis le circuit numérique nous constatons une augmentation de puissance, une superficie de silicium moins compacte, et un traitement de données beaucoup plus lent. Une méthodologie est proposée pour le traitement du signal qui établi la conversion analogue à numérique sur les signaux de tension et tout en mettant en oeuvre tous les circuits dans un format numérique de type circuit à semiconducteur oxyde-métal à symétrie complémentaire (CMOS). Cette méthodologie reconnue sur le nom de technique-temporelle donne un traitement de signal par domaine temporel en employant la variance de cadence entre les temps comme un signal intermédiare entre la tension d'entrée et la tension de sortie numérique. Les formats numériques de type circuit semiconducteur nous offrent une alternative en temps convertisseur d'analogue à numérique avec l'avantage d'une unité compact, robuste, un coût de puissance réduit, et une haute-vitesse efficace. Il existe cinq topologies principales dans les convertisseurs analogiques à numérique: flash, approximations successives, pipeline, delta-sigma, convertisseurs intégrés. Dans chacune des topologies mentionnées ci-dessus, le traitement de signal par technique-temporelle est une méthode réconnue. Les circuits employés par chaque convertisseur de donnée par technique temporelle sont décrits lorsque le niveau du système est approprié, le niveau du transitor, et les données expérimentales sont identifiés. Trois circuits intégrés (CI) ont été conçus et fabriqués, avec une technologie de 0,18-µm CMOS pour démontrer la possibilité de la méthodologie du techniquetemporelle convertisseur analogique-numéri
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Guttman, Michael. « Sampled-data IIR filtering via time-mode signal processing ». Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86770.

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In this work, the design of sampled-data infinite impulse response filters based on time-mode signal processing circuits is presented. Time-mode signal processing (TMSP), defined as the processing of sampled analog information using time-difference variables, has become one of the more popular emerging technologies in circuit design. As TMSP is still relatively new, there is still much development needed to extend the technology into a general signal-processing tool. In this work, a set of general building block will be introduced that perform the most basic mathematical operations in the time-mode. By arranging these basic structures, higher-order time-mode systems, specifically, time-mode filters, will be realized. Three second-order time-mode filters (low-pass, band-reject, high-pass) are modeled using MATLAB, and simulated in Spectre to verify the design methodology. Finally, a damped integrator and a second-order low-pass time-mode IIR filter are both implemented using discrete components.
Dans ce mémoire, la conception de filtres de données-échantillonnées ayant une réponse impulsionnelle infinie basée sur le traitement de signal en mode temporel est présentée. Le traitement de signal dans le domaine temporel (TSDT), définie comme étant le traitement d'information analogique échantillonnée en utilisant des différences de temps comme variables, est devenu une des techniques émergentes de conception de circuits des plus populaires. Puisque le TSDT est toujours relativement récent, il y a encore beaucoup de développements requis pour étendre cette technologie comme un outil de traitement de signal général. Dans cette recherche, un ensemble de blocs d'assemblage capable de réaliser la plupart des opérations mathématiques dans le domaine temporel sera introduit. En arrangeant ces structures élémentaires, des systèmes en mode temporel d'ordre élevé, plus spécifiquement des filtres en mode temporel, seront réalisés. Trois filtres de deuxième ordre dans le domaine temporel (passe-bas, passe-bande et passe-haut) sont modélisés sur MATLAB et simulé sur Spectre afin de vérifier la méthodologie de conception. Finalement, un intégrateur amorti et un filtre passe-bas IIR de deuxième ordre en mode temporel sont implémentés avec des composantes discrètes.
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Tirunagari, Santosh. « Dynamic mode decomposition for computer vision and signal processing ». Thesis, University of Surrey, 2017. http://epubs.surrey.ac.uk/813255/.

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The method of Dynamic Mode Decomposition (DMD) was introduced originally in the area of Computatational Fluid Dynamics (CFD) for extracting coherent structures from spatio-temporal complex fluid flow data. DMD takes in time series data and computes a set of modes, each of which is associated with a complex eigenvalue. DMD analysis is closely associated with spectral analysis of the Koopman operator, which provides linear but infinite-dimensional representation of nonlinear dynamical systems. Therefore, by using DMD a nonlinear system could be described by a superposition of modes whose dynamics are governed by the eigenvalues. The key advantage of DMD is its data-driven nature which does not rely on any prior assumptions except the inherent dynamics which are observed over time. Its capability for extracting relevant modes from complex fluid flows has seen significant application across multiple fields, including computer vision, robotics and neuroscience. This thesis, in order to expand DMD to other applications, advances the original formulation so that it can be used to solve novel problems in the fields of signal processing and computer vision. In signal processing this thesis introduces the method of using DMD for decomposing a univariate time series into a number of interpretable elements with different subspaces, such as noise, trends and harmonics. In addition, univariate time series forecasting is shown using DMD. The computer vision part of this thesis focuses on innovative applications pertaining to the areas of medical imaging, biometrics and background modelling. In the area of medical imaging a novel DMD framework is proposed that introduces windowed and reconstruction variants of DMD for quantifying kidney function in Dynamic Contrast Enhanced Magnetic Resonance imaging (DCE-MRI) sequences, through movement correction and functional segmentation of the kidneys. The biometrics portion of this thesis introduces a DMD based classification pipeline for counter spoofing 2D facial videos and static finger vein images. The finger vein counter spoofing makes use of a novel atemporal variant of DMD that captures micro-level artefacts that can differentiate the quality and light reflection properties between a live and a spoofed finger vein image, while the DMD on 2D facial image sequences distinguishes attack specific cues from a live face by capturing complex dynamics of head movements, eye-blinking and lip-movements in a data driven manner. Finally, this thesis proposes a new technique using DMD to obtain a background model of a visual scene in the colour domain. These aspects form the major contributions of this thesis. The results from this thesis present DMD as a promising approach for applications requiring feature extraction including: (i) trends and noise from signals, (ii) micro-level texture descriptor from images, and (iii) coherent structures from image sequences/videos, as well as applications that require suppression of movements from dynamical spatio-temporal image sequences.
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Bhattaram, Sneha. « Signal Compression Methods for a Wear Debris Sensor ». University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1399201029.

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Ali-Bakhshian, Mohammad. « Digital processing of analog information adopting time-mode signal processing ». Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114237.

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As CMOS technologies advance to 22-nm dimensions and below, constructing analog circuits in such advanced processes suffers many limitations, such as reduced signal swings, sensitivity to thermal noise effects, loss of accurate switching functions, to name just a few. Time-Mode Signal Processing (TMSP) is a technique that is believed to be well suited for solving many of these challenges. It can be defined as the detection, storage, and manipulation of sampled analog information using time-mode variables. One of the important advantages of TMSP is the ability to realize analog functions using digital logic structures. This technique has a long history of application in electronics; however, due to lack of some fundamental functions, the use of TM variables has been mostly limited to intermediate stage processing and it has been always associated with voltage/current-to-time and time-to-voltage/current conversion. These conversions necessitate the inclusion of analog blocks that contradict the digital advantage of TMSP. In this thesis, an intensive research has been presented that provides an appropriate foundation for the development of TMSP as a general processing tool. By proposing the new concept of delay interruption, a completely new asynchronous approach for the manipulation of TM variables is suggested. As a direct result of this approach, practical techniques for storage, addition and subtraction of time-mode variables are presented. To Extend the digital implementation of TMSP to a wider range of applications, the comprehensive design of a unity gain dual-path time-to-time integrator (accumulator) is demonstrated. This integrator is then used to implement a digital second-order delta-sigma modulator. Finally, to demonstrate the advantage of TMSP, a very low power and compact tunable interface for capacitive sensors is presented that is composed of a number of delay blocks associated with typical logic gates. All the proposed theories are supported by experimental results and post-layout simulations.The emphasis on the digital construction of the proposed circuits has been the first priority of this thesis. Having the building blocks implemented with a digital structure, provides the feasibility of a simple, synthesizable, and reconfigurable design where affordable circuit calibrations can be adopted to remove the effects of process variations.
Les technologies CMOS progressant vers les procédés 22 nm et au delà, la abrication des circuits analogiques dans ces technologies se heurte a de nombreuses limitations. Entre autres limitations on peut citer la réduction d'amplitude des signaux, la sensibilité aux effets du bruit thermique et la perte de fonctions précises de commutation. Le traitement de signal en mode temps (TMSP pour Time-Mode Signal Processing) est une technique que l'on croit être bien adapté pour résoudre un grand nombre de problèmes relatifs a ces limitations. TMSP peut être défini comme la détection, le stockage et la manipulation de l'information analogique échantillonnée en utilisant des quantités de temps comme variables. L'un des avantages importants de TMSP est la capacité à réaliser des fonctions analogiques en utilisant des structures logiques digitales. Cette technique a une longue histoire en terme d'application en électronique. Cependant, en raison du manque de certaines fonctions fondamentales, l'utilisation de variables en mode temps a été limitée à une utilisation comme étape intermédiaire dans le traitement d'un signal et toujours dans le contexte d'une conversion tension/courant-temps et temps-tension/courant. Ces conversions nécessitent l'inclusion de blocs analogiques qui vont a l'encontre de l'avantage numérique des TMSP. Cette thèse fournit un fondement approprié pour le développement de TMSP comme outil général de traitement de signal. En proposant le concept nouveau d'interruption de retard, une toute nouvelle approche asynchrone pour la manipulation de variables en mode temps est suggéré. Comme conséquence directe de cette approche, des techniques pratiques pour le stockage, l'addition et la soustraction de variables en mode temps sont présentées. Pour étendre l'implémentation digitale de TMSP à une large gamme d'applications, la conception d'un intégrateur (accumulateur) à double voie temps- à -temps est démontrée. cet intégrateur est ensuite utilisé pour implémenter un modulateur delta-sigma de second ordre.Enfin, pour démontrer l'avantage de TMSP, une Interface de très basse puissance, compacte et réglable pour capteurs capacitifs est présenté. Cette interface est composé d'un certain nombre de blocs de retard associés à des portes logiques typiques. Toutes les théories proposées sont soutenues par des résultats expérimentaux et des simulations post-layout. L'implémentation digitale des circuits proposés a été la première priorité de cette thèse. En effet, une implémentation des bloc avec des structures digitales permet des conceptions simples, synthétisable et reconfigurables où des circuits de calibration très abordables peuvent être adoptées pour éliminer les effets des variations de process.
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Bi, G. « Application of mode controlled logic to pipelined serial signal processing] ». Thesis, University of Essex, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381239.

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Bergogne, Christian. « Transmission en mode paquet à faible rapport signal à bruit / ». Paris : École nationale supérieure des télécommunications, 1997. http://catalogue.bnf.fr/ark:/12148/cb36165913n.

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Holzner, Jürgen. « Signal theory and processing for Burst-mode and ScanSAR interferometry ». Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/23054.

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ScanSAR data provides wide swath coverage and at fast revisit times at the expense of resolution. Moreover, the ENVISAT/ASAR alternating polarisation mode uses the burst-mode acquisition to map the scene quasi-parallel in two polarisations. Both modes are also attractive for interferometric applications, e.g. efficient topographic mapping of large areas and monitoring of large scale motions. A single-pass ScanSAR interferometer was flown during the 11-day Shuttle Radar Topographic Mission (SRTM). Repeat-pass ScanSAR data are routinely available from RADARSAT-1 and ENVISAT/ASAR and the coming RADARSAT-2 and ALOS/PALSAR mission will also provide ScanSAR imaging modes. This thesis provides a complete description of burst-mode and ScanSAR signal characteristics, algorithms for interferometric processing, and options for the efficient utilisation of the wide-swath data. In the course of the examinations the following problems are addressed: Doppler centroid estimation, azimuth scanning pattern synchronisation, common band filtering and resampling in the presence of high squint, beam alignment, and interferogram formation. A new fast time-variant interpolator for burst-mode data is introduced and tested. Several processing options are described that exploit the flexibility of burst-mode and ScanSAR data. Hence, possibilities are available for prototype systems that are most conveniently integrated into existing strip-map processors and for systems that allow data processing in operational fashion. A prototype processor that makes efficient use of the burst-mode and ScanSAR data properties was implemented and tested using a RADARSAT-1 ScanRAR Narrow data set. In this way, RADARSAT-1 repeat-pass ScanSAR interferometry is demonstrated. The generated digital elevation model has quality in the order or better than DTED-1. Moreover, after interferometric processing the ScanSAR interferogram resembles a course resolution strip-map interferogram and, hence, possibly all applications of SAR interferometry may benefit from ScanSAR data. In particular, the data is favourable for those applications gaining from the wide swath extend, the fast revisit times, or from the increase in information provided with the alternating polarisation mode, as on ENVISAT/ASAR.
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Livres sur le sujet "Modélisation du signal"

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Couwenbergh, Jean-Pierre. AutoCAD 3D : Mode lisation et rendu. Paris : Eyrolles, 2007.

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Dodd, Alan J. Current-mode signal processing circuits. Manchester : UMIST, 1996.

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Moigne, Jean Louis Le. La the orie du syste me ge ne ral : The orie de la mode lisation. 4e éd. Paris : Presses universitaires de France, 1994.

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Louis, Jean-Paul. Mode lisation des machines e lectriques en vue de leur commande : Concepts ge ne raux. Paris : Lavoisier, 2004.

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Yuan, Fei. Injection-Locking in Mixed-Mode Signal Processing. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-17364-7.

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Jakowatz, Charles V., Daniel E. Wahl, Paul H. Eichel, Dennis C. Ghiglia et Paul A. Thompson. Spotlight-Mode Synthetic Aperture Radar : A Signal Processing Approach. Boston, MA : Springer US, 1996. http://dx.doi.org/10.1007/978-1-4613-1333-5.

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Jakowatz, Charles V. Spotlight-Mode Synthetic Aperture Radar : A Signal Processing Approach. Boston, MA : Springer US, 1996.

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1951-, Newton A. Richard, dir. Mixed-mode simulation. Boston : Kluwer Academic Publishers, 1990.

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Kazuhiro, Kohama, dir. Calcium inhibition : A new mode for CA²⁺ regulation. Tokyo : Japan Scientific Societies Press, 1992.

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Robert, Stengel, et Thompson Bruce M, dir. Microwave differential circuit design using mixed-mode s-parameters. Boston, MA : Artech House, 2006.

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Chapitres de livres sur le sujet "Modélisation du signal"

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Moschytz, George S. « Mixed-Mode Signal Processing ». Dans Analog Circuit Theory and Filter Design in the Digital World, 3–18. Cham : Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-00096-7_1.

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Neumann, Ernst-Georg. « Signal Transmission Through Single-Mode Fibers ». Dans Single-Mode Fibers, 238–76. Berlin, Heidelberg : Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-540-48173-7_11.

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Safari, Leila, Giuseppe Ferri, Shahram Minaei et Vincenzo Stornelli. « Current-Mode Wheatstone Bridge ». Dans Analog Circuits and Signal Processing, 29–57. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01343-1_3.

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Desai, Mehul, et Peter Aronhime. « Current-Mode Synthesis Using Node Expansion Techniques ». Dans Analog Signal Processing, 79–87. Boston, MA : Springer US, 1994. http://dx.doi.org/10.1007/978-1-4757-4503-0_7.

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Safari, Leila, Giuseppe Ferri, Shahram Minaei et Vincenzo Stornelli. « Current-Mode Instrumentation Amplifiers Based on Various Current-Mode Building Blocks ». Dans Analog Circuits and Signal Processing, 71–94. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01343-1_5.

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Bi, Xiaojun, Qiang Ma, Zilan Cao et Qinfen Xu. « Analysis of Multi-Mode Resonator ». Dans Analog Circuits and Signal Processing, 7–22. Singapore : Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-7841-7_2.

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Safari, Leila, Giuseppe Ferri, Shahram Minaei et Vincenzo Stornelli. « Electronically Controllable Current-Mode Instrumentation Amplifiers ». Dans Analog Circuits and Signal Processing, 95–125. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01343-1_6.

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van Dongen, Marijn, et Wouter Serdijn. « Switched-Mode High Frequency Stimulator Design ». Dans Analog Circuits and Signal Processing, 97–119. Cham : Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-28131-5_7.

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Safari, Leila, Giuseppe Ferri, Shahram Minaei et Vincenzo Stornelli. « Current-Mode Instrumentation Amplifiers Using Current Conveyors ». Dans Analog Circuits and Signal Processing, 59–69. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01343-1_4.

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Safari, Leila, Giuseppe Ferri, Shahram Minaei et Vincenzo Stornelli. « Mismatch Implications in Current-Mode Instrumentation Amplifiers ». Dans Analog Circuits and Signal Processing, 127–36. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01343-1_7.

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Actes de conférences sur le sujet "Modélisation du signal"

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Lobato, Adriana, Filipe Ferreira, Johannes Rabe, Beril Inan, Susmita Adhikari, Maxim Kuschnerov, Antonio Napoli, Bernhard Spinnler et Berthold Lankl. « Mode-Dependent-Loss Mitigation for Mode-Division Multiplexed Systems ». Dans Signal Processing in Photonic Communications. Washington, D.C. : OSA, 2013. http://dx.doi.org/10.1364/sppcom.2013.spt4d.3.

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Amhoud, El Mehdi, Yves Jaouën et Ghaya Rekaya Ben-Othman. « Optimal Mode Scrambling for Mode-Multiplexed Optical Fiber Transmission Systems ». Dans Signal Processing in Photonic Communications. Washington, D.C. : OSA, 2016. http://dx.doi.org/10.1364/sppcom.2016.sptu3f.2.

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Awaji, Yoshinari, Hideaki Furukawa, Naoya Wada, Peter Chan et Ray Man. « Challenges toward burst-mode EDFA ». Dans Signal Processing (ICICS). IEEE, 2009. http://dx.doi.org/10.1109/icics.2009.5397488.

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Kotov, Oleg, et Ivan Chapalo. « Signal-to-noise ratio for mode-mode fiber interferometer ». Dans SPIE Optical Metrology, sous la direction de Peter Lehmann, Wolfgang Osten et Armando Albertazzi Gonçalves. SPIE, 2017. http://dx.doi.org/10.1117/12.2270272.

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Amhoud, El Mehdi, Ghaya Rekaya Ben-Othman et Yves Jaouën. « Combined Polarization- and Mode-Dependent Loss Effects on Few-Mode Fibers systems ». Dans Signal Processing in Photonic Communications. Washington, D.C. : OSA, 2017. http://dx.doi.org/10.1364/sppcom.2017.spm4f.3.

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Behera, Bhagyalaxmi, S. K. Varshney et Mihir Narayan Mohanty. « Design of Seven-LP-Mode Compound-Index Few-Mode-Fiber for Mode-Division-Multiplexing Transmission ». Dans 2020 International Conference on Communication and Signal Processing (ICCSP). IEEE, 2020. http://dx.doi.org/10.1109/iccsp48568.2020.9182294.

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Swain, Smaranika, Srikrishna Bhashyam, Ravinder D. Koilpillai et Deepa Venkitesh. « Performance characterization of digital power division multiplexed transmission in fundamental mode of few-mode fiber ». Dans Signal Processing in Photonic Communications. Washington, D.C. : OSA, 2020. http://dx.doi.org/10.1364/sppcom.2020.spm4i.2.

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Rohila, Ashish, Raj Kumar Patel et Vinod Kumar Giri. « Signal denoising by empirical mode decomposition ». Dans 2016 International Conference on Emerging Trends in Electrical Electronics & Sustainable Energy Systems (ICETEESES). IEEE, 2016. http://dx.doi.org/10.1109/iceteeses.2016.7581410.

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Ataer-Cansizoglu, Esra, et Deniz Erdogmus. « A mode-based clustering algorithm without mode seeking ». Dans ICASSP 2012 - 2012 IEEE International Conference on Acoustics, Speech and Signal Processing. IEEE, 2012. http://dx.doi.org/10.1109/icassp.2012.6288281.

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Pan, Z., Y. Weng, X. He et J. Wang. « Adaptive Frequency-Domain Equalization and MIMO Signal Processing in Mode Division Multiplexing Systems using Few-Mode Fibers ». Dans Signal Processing in Photonic Communications. Washington, D.C. : OSA, 2016. http://dx.doi.org/10.1364/sppcom.2016.spw2g.1.

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Rapports d'organisations sur le sujet "Modélisation du signal"

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DeFerrari, Harry A. Normal Mode Properties and Signal Coherence in Shallow Water Propagation. Fort Belvoir, VA : Defense Technical Information Center, septembre 2012. http://dx.doi.org/10.21236/ada574833.

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Edelblute, David J. Array Processing That Uses a Normal-Mode Model for Signal Representation. Fort Belvoir, VA : Defense Technical Information Center, mai 1988. http://dx.doi.org/10.21236/ada198031.

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Zhou, Feng, Lijun Yang, Hao-min Zhou et Lihua Yang. Optimal Averages for Nonlinear Signal Decompositions - Another Alternative for Empirical Mode Decomposition. Fort Belvoir, VA : Defense Technical Information Center, octobre 2014. http://dx.doi.org/10.21236/ada610276.

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Chamovitz, Daniel, et Albrecht Von Arnim. Translational regulation and light signal transduction in plants : the link between eIF3 and the COP9 signalosome. United States Department of Agriculture, novembre 2006. http://dx.doi.org/10.32747/2006.7696515.bard.

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The COP9 signalosome (CSN) is an eight-subunit protein complex that is highly conserved among eukaryotes. Genetic analysis of the signalosome in the plant model species Arabidopsis thaliana has shown that the signalosome is a repressor of light dependent seedling development as mutant Arabidopsis seedlings that lack this complex develop in complete darkness as if exposed to light. These mutant plants die following the seedling stage, even when exposed to light, indicating that the COP9 signalosome also has a central role in the regulation of normal photomorphogenic development. The biochemical mode of action of the signalosome and its position in eukaryotic cell signaling pathways is a matter of controversy and ongoing investigation, and recent results place the CSN at the juncture of kinase signaling pathways and ubiquitin-mediated protein degradation. We have shown that one of the many CSN functions may relate to the regulation of translation through the interaction of the CSN with its related complex, eukaryotic initiation factor (eIF3). While we have established a physical connection between eIF3 subunits and CSN subunits, the physiological and developmental significance of this interaction is still unknown. In an effort to understand the biochemical activity of the signalosome, and its role in regulating translation, we originally proposed to dissect the contribution of "h" subunit of eIF3 (eIF3h) along the following specific aims: (i) Isolation and phenotypic characterization of an Arabidopsis loss-of-function allele for eIF3h from insertional mutagenesis libraries; (ii) Creation of designed gain and loss of function alleles for eIF3h on the basis of its nucleocytoplasmic distribution and its yeast-two-hybrid interactions with other eIF3 and signalosome partner proteins; (iii) Determining the contribution of eIF3h and its interaction with the signalosome by expressing specific mutants of eIF3h in the eIF3h- loss-of function background. During the course of the research, these goals were modified to include examining the genetic interaction between csn and eif3h mutations. More importantly, we extended our effort toward the genetic analysis of mutations in the eIF3e subunit, which also interacts with the CSN. Through the course of this research program we have made several critical scientific discoveries, all concerned with the apparent diametrically opposed roles of eIF3h and eIF3e. We showed that: 1) While eIF3e is essential for growth and development, eIF3h is not essential for growth or basal translation; 2) While eIF3e has a negative role in translational regulation, eIF3h is positively required for efficient translation of transcripts with complex 5' UTR sequences; 3) Over-accumulation of eIF3e and loss-of-function of eIF3h both lead to cop phenotypes in dark-grown seedlings. These results were published in one publication (Kim et al., Plant Cell 2004) and in a second manuscript currently in revision for Embo J. Are results have led to a paradigm shift in translation research – eIF3 is now viewed in all systems as a dynamic entity that contains regulatory subuits that affect translational efficiency. In the long-term agronomic outlook, the proposed research has implications that may be far reaching. Many important plant processes, including developmental and physiological responses to light, abiotic stress, photosynthate, and hormones operate in part by modulating protein translation [23, 24, 40, 75]. Translational regulation is slowly coming of age as a mechanism for regulating foreign gene expression in plants, beginning with translational enhancers [84, 85] and more recently, coordinating the expression of multiple transgenes using internal ribosome entry sites. Our contribution to understanding the molecular mode of action of a protein complex as fundamental as eIF3 is likely to lead to advances that will be applicable in the foreseeable future.
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O'Neill, Sharman, Abraham Halevy et Amihud Borochov. Molecular Genetic Analysis of Pollination-Induced Senescence in Phalaenopsis Orchids. United States Department of Agriculture, 1991. http://dx.doi.org/10.32747/1991.7612837.bard.

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The project investigated the molecular genetic and biochemical basis of pollination-induced senescence of Phalaenopsis flowers. This experimental system offered unique advantages in that senescence is strictly regulated by pollination, providing the basis to experimentally initiate and synchronize senescence in populations of flowers. The postpollination syndrome in the Phalaenopsis orchid system was dissected by investigating the temporal and spatial regulation of ACC synthase gene expression. In the stigma, pollen-borne auxin induces the expression of the auxin-regulated ACC synthase (PS-ACS2) gene, resulting in ACC synthesis within 1 h following pollination. Newly formed ACC is oxidized by basal constitutive ACC oxidase to ethylene, which then induces the expression of the ethylene-regulated ACC synthase(PS-ACS1) and oxidase (ACO1) genes for further autocatalytic production of ethylene. It is speculated that during the 6-h period following pollination, emasculation leads to the production or release of a sensitivity factor that sensitizes the cells of the stigma to ethylene. ACC and ethylene molecules are translocated from the stigma to the labellum and perianth where ethylene induces the expression of PS-ACS1 and ACO1 resulting in an increased production of ACC and ethylene. Organ-localized ethylene is responsible for inrolling and senescence of the labellum and perianth. The regulation of ethylene sensitivity and signal transduction events in pollinated flowers was also investigated. The increase in ethylene sensitivity appeared in both the flower column and the perianth, and was detected as early as 4 h after pollination. The increase in ethylene sensitivity following pollination was not dependent on endogenous ethylene production. Application of linoleic and linoleic acids to Phalaenopsis and Dendrobium flowers enhanced their senescence and promoted ethylene production. Several major lipoxygenase pathway products including JA-ME, traumatic acid, trans-2-hexenal and cis-3-hexenol, also enhanced flower senescence. However, lipoxygenase appears to not be directly involved in the endogenous regulation of pollination-induced Phalaenopsis and Dendrobium flower senescence. The data suggest that short-chain saturated fatty acids may be the ethylene "sensitivity factors" produced following pollination, and that their mode of action involves a decrease in the order of specific regions i the membrane lipid bilayer, consequently altering ethylene action. Examination of potential signal transduction intermediates indicate a direct involvement of GTP-binding proteins, calcium ions and protein phosphorylation in the cellular signal transduction response to ethylene following pollination. Modulations of cytosolic calcium levels allowed us to modify the flowers responsiveness to ethylene.
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Coplin, David L., Shulamit Manulis et Isaac Barash. roles Hrp-dependent effector proteins and hrp gene regulation as determinants of virulence and host-specificity in Erwinia stewartii and E. herbicola pvs. gypsophilae and betae. United States Department of Agriculture, juin 2005. http://dx.doi.org/10.32747/2005.7587216.bard.

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Gram-negative plant pathogenic bacteria employ specialized type-III secretion systems (TTSS) to deliver an arsenal of pathogenicity proteins directly into host cells. These secretion systems are encoded by hrp genes (for hypersensitive response and pathogenicity) and the effector proteins by so-called dsp or avr genes. The functions of effectors are to enable bacterial multiplication by damaging host cells and/or by blocking host defenses. We characterized essential hrp gene clusters in the Stewart's Wilt of maize pathogen, Pantoea stewartii subsp. stewartii (Pnss; formerly Erwinia stewartii) and the gall-forming bacterium, Pantoea agglomerans (formerly Erwinia herbicola) pvs. gypsophilae (Pag) and betae (Pab). We proposed that the virulence and host specificity of these pathogens is a function of a) the perception of specific host signals resulting in bacterial hrp gene expression and b) the action of specialized signal proteins (i.e. Hrp effectors) delivered into the plant cell. The specific objectives of the proposal were: 1) How is the expression of the hrp and effector genes regulated in response to host cell contact and the apoplastic environment? 2) What additional effector proteins are involved in pathogenicity? 3) Do the presently known Pantoea effector proteins enter host cells? 4) What host proteins interact with these effectors? We characterized the components of the hrp regulatory cascade (HrpXY ->7 HrpS ->7 HrpL ->7 hrp promoters), showed that they are conserved in both Pnss and Fag, and discovered that the regulation of the hrpS promoter (hrpSp) may be a key point in integrating apoplastic signals. We also analyzed the promoters recognized by HrpL and demonstrated the relationship between their composition and efficiency. Moreover, we showed that promoter strength can influence disease expression. In Pnss, we found that the HrpXY two-component signal system may sense the metabolic status of the bacterium and is required for full hrp gene expression in planta. In both species, acyl-homoserine lactone-mediated quorum sensing may also regulate epiphytic fitness and/or pathogenicity. A common Hrp effector protein, DspE/WtsE, is conserved and required for virulence of both species. When introduced into corn cells, Pnss WtsE protein caused water-soaked lesions. In other plants, it either caused cell death or acted as an Avr determinant. Using a yeast- two-hybrid system, WtsE was shown to interact with a number of maize signal transduction proteins that are likely to have roles in either programmed cell death or disease resistance. In Pag and Pab, we have characterized the effector proteins HsvG, HsvB and PthG. HsvG and HsvB are homologous proteins that determine host specificity of Pag and Pab on gypsophila and beet, respectively. Both possess a transcriptional activation domain that functions in yeast. PthG was found to act as an Avr determinant on multiple beet species, but was required for virulence on gypsophila. In addition, we demonstrated that PthG acts within the host cell. Additional effector genes have been characterized on the pathogenicity plasmid, pPATHₚₐg, in Pag. A screen for HrpL- regulated genes in Pnsspointed up 18 candidate effector proteins and four of these were required for full virulence. It is now well established that the virulence of Gram-negative plant pathogenic bacteria is governed by Hrp-dependent effector proteins. However; the mode of action of many effectors is still unresolved. This BARD supported research will significantly contribute to the understanding of how Hrp effectors operate in Pantoea spp. and how they control host specificity and affect symptom production. This may lead to novel approaches for genetically engineering plants resistant to a wide range of bacterial pathogens by inactivating the Hrp effectors with "plantabodies" or modifying their receptors, thereby blocking the induction of the susceptible response. Alternatively, innovative technologies could be used to interfere with the Hrp regulatory cascade by blocking a critical step or mimicking plant or quorum sensing signals.
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Friedman, Haya, Julia Vrebalov et James Giovannoni. Elucidating the ripening signaling pathway in banana for improved fruit quality, shelf-life and food security. United States Department of Agriculture, octobre 2014. http://dx.doi.org/10.32747/2014.7594401.bard.

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Background : Banana being a monocot and having distinct peel and pulp tissues is unique among the fleshy fruits and hence can provide a more comprehensive understanding of fruit ripening. Our previous research which translated ripening discoveries from tomato, led to the identification of six banana fruit-associated MADS-box genes, and we confirmed the positive role of MaMADS1/2 in banana ripening. The overall goal was to further elucidate the banana ripening signaling pathway as mediated by MADS-boxtranscriptional regulators. Specific objectives were: 1) characterize transcriptional profiles and quality of MaMADS1/2 repressed fruit; 2) reveal the role of additional MaMADSgenes in ripening; 3) develop a model of fruit MaMADS-box mode of action; and 4) isolate new components of the banana ripening signaling pathway. Major conclusion: The functions of the banana MaMADS1-5 have been examined by complimenting the rinor the TAGL1-suppressed lines of tomato. Only MaMADS5 exhibited partial complementation of TAGL1-suppressed and rinlines, suggesting that while similar genes play corresponding roles in ripening, evolutionary divergence makes heterologous complementation studies challenging. Nevertheless, the partial complementation of tomato TAGL1-surpessed and rinlines with MaMADS5 suggests this gene is likely an important ripening regulator in banana, worthy of further study. RNA-seqtranscriptome analysis during ripening was performed on WT and MaMADS2-suppressed lines revealing additional candidate genes contributing to ripening control mechanisms. In summary, we discovered 39 MaMADS-box genes in addition to homologues of CNR, NOR and HB-1 expressed in banana fruits, and which were shown in tomato to play necessary roles in ripening. For most of these genes the expression in peel and pulp was similar. However, a number of key genes were differentially expressed between these tissues indicating that the regulatory components which are active in peel and pulp include both common and tissue-specific regulatory systems, a distinction as compared to the more uniform tomato fruit pericarp. Because plant hormones are well documented to affect fruit ripening, the expressions of genes within the auxin, gibberellin, abscisic acid, jasmonic acid, salicylic and ethylene signal transduction and synthesis pathways were targeted in our transcriptome analysis. Genes’ expression associated with these pathways generally declined during normal ripening in both peel and pulp, excluding cytokinin and ethylene, and this decline was delayed in MaMADS2-suppressed banana lines. Hence, we suggest that normal MaMADS2 activity promotes the observed downward expression within these non-ethylene pathways (especially in the pulp), thus enabling ripening progression. In contrast, the expressions of ACSand ACOof the ethylene biosynthesis pathway increase in peel and pulp during ripening and are delayed/inhibited in the transgenic bananas, explaining the reduced ethylene production of MaMADS2-suppressed lines. Inferred by the different genes’ expression in peel and pulp of the gibberellins, salicylic acid and cytokinins pathways, it is suggested that hormonal regulation in these tissues is diverse. These results provide important insights into possible avenues of ripening control in the diverse fruit tissues of banana which was not previously revealed in other ripening systems. As such, our transcriptome analysis of WT and ripening delayed banana mutants provides a starting point for further characterization of ripening. In this study we also developed novel evidence that the cytoskeleton may have a positive role in ripening as components of this pathway were down-regulated by MaMADS2 suppression. The mode of cytoskeleton involvement in fruit ripening remains unclear but presents a novel new frontier in ripening investigations. In summary, this project yielded functional understanding of the role and mode of action of MaMADS2 during ripening, pointing to both induction of ethylene and suppression of non-ethylene hormonal singling pathways. Furthermore, our data suggest important roles for cytoskeleton components and MaMADS5 in the overall banana ripening control network. Implications: The project revealed new molecular components/genes involved in banana ripening and refines our understanding of ripening responses in the peel and pulp tissues of this important species. This information is novel as compared to that derived from the more uniform carpel tissues of other highly studied ripening systems including tomato and grape. The work provides specific target genes for potential modification through genetic engineering or for exploration of useful genetic diversity in traditional breeding. The results from the project might point toward improved methods or new treatments to improve banana fruit storage and quality.
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Meidan, Rina, et Robert Milvae. Regulation of Bovine Corpus Luteum Function. United States Department of Agriculture, mars 1995. http://dx.doi.org/10.32747/1995.7604935.bard.

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The main goal of this research plan was to elucidate regulatory mechanisms controlling the development, function of the bovine corpus luteum (CL). The CL contains two different sterodigenic cell types and therefore it was necessary to obtain pure cell population. A system was developed in which granulosa and theca interna cells, isolated from a preovulatory follicle, acquired characteristics typical of large (LL) and small (SL) luteal cells, respectively, as judged by several biochemical and morphological criteria. Experiments were conducted to determine the effects of granulosa cells removal on subsequent CL function, the results obtained support the concept that granulosa cells make a substaintial contribution to the output of progesterone by the cyclic CL but may have a limited role in determining the functional lifespan of the CL. This experimental model was also used to better understand the contribution of follicular granulosa cells to subsequent luteal SCC mRNA expression. The mitochondrial cytochrome side-chain cleavage enzyme (SCC), which converts cholesterol to pregnenolone, is the first and rate-limiting enzyme of the steroidogenic pathway. Experiments were conducted to characterize the gene expression of P450scc in bovine CL. Levels of P450scc mRNA were higher during mid-luteal phase than in either the early or late luteal phases. PGF 2a injection decreased luteal P450scc mRNA in a time-dependent manner; levels were significantly reduced by 2h after treatment. CLs obtained from heifers on day 8 of the estrous cycle which had granulosa cells removed had a 45% reduction in the levels of mRNA for SCC enzymes as well as a 78% reduction in the numbers of LL cells. To characterize SCC expression in each steroidogenic cell type we utilized pure cell populations. Upon luteinization, LL expressed 2-3 fold higher amounts of both SCC enzymes mRNAs than SL. Moreover, eight days after stimulant removal, LL retained their P4 production capacity, expressed P450scc mRNA and contained this protein. In our attempts to establish the in vitro luteinization model, we had to select the prevulatory and pre-gonadotropin surge follicles. The ratio of estradiol:P4 which is often used was unreliable since P4 levels are high in atretic follicles and also in preovulatory post-gonadotropin follicles. We have therefore examined whether oxytocin (OT) levels in follicular fluids could enhance our ability to correctly and easily define follicular status. Based on E2 and OT concentrations in follicular fluids we could more accurately identify follicles that are preovulatory and post gonadotropin surge. Next we studied OT biosynthesis in granulosa cells, cells which were incubated with forskolin contained stores of the precursor indicating that forskolin (which mimics gonadotropin action) is an effective stimulator of OT biosynthesis and release. While studying in vitro luteinization, we noticed that IGF-I induced effects were not identical to those induced by insulin despite the fact that megadoses of insulin were used. This was the first indication that the cells may secrete IGF binding protein(s) which regonize IGFs and not insulin. In a detailed study involving several techniques, we characterized the species of IGF binding proteins secreted by luteal cells. The effects of exogenous polyunsaturated fatty acids and arachidonic acid on the production of P4 and prostanoids by dispersed bovine luteal cells was examined. The addition of eicosapentaenoic acid and arachidonic acid resulted in a dose-dependent reduction in basal and LH-stimulated biosynthesis of P4 and PGI2 and an increase in production of PGF 2a and 5-HETE production. Indomethacin, an inhibitor of arachidonic acid metabolism via the production of 5-HETE was unaffected. Results of these experiments suggest that the inhibitory effect of arachidonic acid on the biosynthesis of luteal P4 is due to either a direct action of arachidonic acid, or its conversion to 5-HETE via the lipoxgenase pathway of metabolism. The detailed and important information gained by the two labs elucidated the mode of action of factors crucially important to the function of the bovine CL. The data indicate that follicular granulosa cells make a major contribution to numbers of large luteal cells, OT and basal P4 production, as well as the content of cytochrome P450 scc. Granulosa-derived large luteal cells have distinct features: when luteinized, the cell no longer possesses LH receptors, its cAMP response is diminished yet P4 synthesis is sustained. This may imply that maintenance of P4 (even in the absence of a Luteotropic signal) during critical periods such as pregnancy recognition, is dependent on the proper luteinization and function of the large luteal cell.
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Multiple Engine Faults Detection Using Variational Mode Decomposition and GA-K-means. SAE International, mars 2022. http://dx.doi.org/10.4271/2022-01-0616.

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As a critical power source, the diesel engine is widely used in various situations. Diesel engine failure may lead to serious property losses and even accidents. Fault detection can improve the safety of diesel engines and reduce economic loss. Surface vibration signal is often used in non-disassembly fault diagnosis because of its convenient measurement and stability. This paper proposed a novel method for engine fault detection based on vibration signals using variational mode decomposition (VMD), K-means, and genetic algorithm. The mode number of VMD dramatically affects the accuracy of extracting signal components. Therefore, a method based on spectral energy distribution is proposed to determine the parameter, and the quadratic penalty term is optimized according to SNR. The results show that the optimized VMD can adaptively extract the vibration signal components of the diesel engine. In the actual fault diagnosis case, it is difficult to obtain the data with labels. The clustering algorithm can complete the classification without labeled data, but it is limited by the low accuracy. In this paper, the optimized VMD is used to decompose and standardize the vibration signal. Then the correlation-based feature selection method is implemented to obtain the feature results after dimensionality reduction. Finally, the results are input into the classifier combined by K-means and genetic algorithm (GA). By introducing and optimizing the genetic algorithm, the number of classes can be selected automatically, and the accuracy is significantly improved. This method can carry out adaptive multiple fault detection of a diesel engine without labeled data. Compared with many supervised learning algorithms, the proposed method also has high accuracy.
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