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Auteur : Grafiati

Publié le 11 mars 2023

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1

Barreras, F., H. Amaveda et A. Lozano. « Transient high-frequency ultrasonic water atomization ». Experiments in Fluids 33, n^o 3 (septembre 2002) : 405–13. http://dx.doi.org/10.1007/s00348-002-0456-1.

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Holopainen, Eero, et Carl Fortelius. « High-Frequency Transient Eddies and Blocking ». Journal of the Atmospheric Sciences 44, n^o 12 (juin 1987) : 1632–45. http://dx.doi.org/10.1175/1520-0469(1987)044<1632:hfteab>2.0.co;2.

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3

Grimes, Craig A. « High‐frequency, transient magnetic susceptibility of ferroelectrics ». Journal of Applied Physics 80, n^o 8 (15 octobre 1996) : 4548–52. http://dx.doi.org/10.1063/1.363436.

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Thornber, K. K. « High-frequency, transient response of microstrip lines ». IEEE Transactions on Electron Devices 37, n^o 7 (juillet 1990) : 1763–70. http://dx.doi.org/10.1109/16.55766.

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5

Skotte, JH. « Exposure to high-frequency transient electromagnetic fields ». Scandinavian Journal of Work, Environment & ; Health 22, n^o 1 (février 1996) : 39–44. http://dx.doi.org/10.5271/sjweh.107.

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6

LUCHTENBURG, DIRK M., BERT GÜNTHER, BERND R. NOACK, RUDIBERT KING et GILEAD TADMOR. « A generalized mean-field model of the natural and high-frequency actuated flow around a high-lift configuration ». Journal of Fluid Mechanics 623 (6 mars 2009) : 283–316. http://dx.doi.org/10.1017/s0022112008004965.

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A low-dimensional Galerkin model is proposed for the flow around a high-lift configuration, describing natural vortex shedding, the high-frequency actuated flow with increased lift and transients between both states. The form of the dynamical system has been derived from a generalized mean-field consideration. Steady state and transient URANS (unsteady Reynolds-averaged Navier–Stokes) simulation data are employed to derive the expansion modes and to calibrate the system parameters. The model identifies the mean field as the mediator between the high-frequency actuation and the low-frequency natural shedding instability.

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Pannila, Earl A. R. L., et Mahesh Edirisinghe. « Signatures of Transient Overvoltages in Low Voltage Power Systems in Tea Factories and Their Implications on Insulation Deterioration and Allied Power Quality Issues ». Journal of Electrical and Computer Engineering 2021 (19 novembre 2021) : 1–12. http://dx.doi.org/10.1155/2021/2623965.

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Electrical equipment and supply cables demand a better quality of supply, with the recent advancements in integrated sensitive solid-state controls. Divergently, proliferated heavy inductive motors and some performance additions based on power electronics have introduced power quality issues to the network. Thus, this study mainly investigates the impact of switching transients generated by electromechanical machines in industrial power systems on insulation deterioration while taking transient overvoltages due to capacitor bank switching also to support. Transients with a high rate of rise are likely to catalyze the degradation of the insulation quality and break down the insulating material through ionization. These steeply passing overvoltage stresses let partial discharges ensue, which can attack the insulation over long service. To unveil this danger, 314 common-mode transient waveforms were measured in the electrical machines of five tea factories in Sri Lanka, in a 50 ms measurement window, taken in 55 measuring attempts. Most of the transients observed are in the form of a damped oscillatory waveform tailed by fast exponential collapse. That correlates to insulation degradation having a very steep rise as 30.04 V/ns, the highest at the withering section. When machines are heavily loaded, situations tend to generate transients with high amplitudes. There were transient bursts that spread as 426.3 ms, while 14 ns fast rise times were recorded from withering motors. Unlike electrical resonance and power-frequency overvoltages, electromagnetic switching transients last even less than 100 ms. To underline this, an analysis of the frequency domain of transients was also presented, which proves high density of high-frequency components reaching 107 kHz range. Accepting the fact that frequency and amplitude are always under the influences of innumerable dynamics, the observational evidence of the study endorses that electrical stress built by the transient nature of the factories reduces the life expectancy of electrical insulation.

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Cheng, Lin, Kui Tang, Wang-Hung Ki et Feng Su. « Fast-transient techniques for high-frequency DC–DC converters ». Journal of Semiconductors 41, n^o 11 (novembre 2020) : 112402. http://dx.doi.org/10.1088/1674-4926/41/11/112402.

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Dubovik, V. M., et M. I. Ryazanov. « High-frequency transient radiation from a complicated-profile boundary ». Physics of Atomic Nuclei 76, n^o 6 (juin 2013) : 678–83. http://dx.doi.org/10.1134/s1063778813060069.

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Chojowski, Maciej, Marcin Baszyński, Robert Sosnowski et Aleksander Dziadecki. « High-Frequency Current Transformers Cascade for Power Electronics Measurements ». Sensors 22, n^o 15 (4 août 2022) : 5846. http://dx.doi.org/10.3390/s22155846.

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High-frequency current transformers (HFCT) are widely used to measure fast transient current. Their advantages are simple structure and relatively moderate price. Their lower and upper bandwidth are limited, but the HFCT can be easily applied to many measuring applications in power electronics. The disadvantages of HFCT are substantial dimensions and a large weight. The paper proposes a system of a cascade connection of two transformers, which allows us to reduce these disadvantages. The properties of such an HFCT combination were investigated and described. In the article, the expression for double current transformer transmittances is derived. The frequency response of the sensor was determined, and the results were verified in a practical arrangement. An experimental setup of a cascade CT connection was made and tested, allowing for fast-changing signals in transients to be measured. This paper presents the theoretical basis and results of laboratory work on a wide range of static and dynamic tests of the proposed sensor.

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Fujita, Shigeto, Khalid Hassan Hussein, Shuichi Kitamura et Takashi Yamaguchi. « Investigation on IGBT High-Frequency Plasma Extraction Transient Time Oscillation ». IEEE Transactions on Power Electronics 24, n^o 6 (juin 2009) : 1570–76. http://dx.doi.org/10.1109/tpel.2009.2015142.

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Bejjani, Boulos-Paul, Philippe Damier, Isabelle Arnulf, Lionel Thivard, Anne-Marie Bonnet, Didier Dormont, Philippe Cornu, Bernard Pidoux, Yves Samson et Yves Agid. « Transient Acute Depression Induced by High-Frequency Deep-Brain Stimulation ». New England Journal of Medicine 340, n^o 19 (13 mai 1999) : 1476–80. http://dx.doi.org/10.1056/nejm199905133401905.

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Butkus, Paulius, Sonata Tolvaišienė et Sebastjanas Kurčevskis. « Validation of a SPICE Model for High Frequency Electroporation Systems ». Electronics 8, n^o 6 (23 juin 2019) : 710. http://dx.doi.org/10.3390/electronics8060710.

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In this paper, we present an analysis and a validation of a simulation program with integrated circuit emphasis (SPICE) model for a pulse forming circuit of a high frequency electroporation system, which can deliver square-wave sub-microsecond (100–900 ns) electric field pulses. The developed SPICE model is suggested for use in evaluation of transient processes that occur due to high frequency operations in prototype systems. A controlled crowbar circuit was implemented to support a variety of biological loads and to ensure a constant electric pulse rise and fall time during electroporation to be independent of the applied buffer bioimpedance. The SPICE model was validated via a comparison of the simulation and experimental results obtained from the already existing prototype system. The SPICE model results were in good agreement with the experimental results, and the model complexity was found to be sufficient for analysis of transient processes. As result, the proposed SPICE model can be useful for evaluation and compensation of transient processes in sub-microsecond pulsed power set-ups during the development of new prototypes.

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Gross-Glenn, Karen, Bernt C. Skottun, William Glenn, Alex Kushch, Robert Lingua, Mark Dunbar, Bonnie Jallad et al. « Contrast sensitivity in dyslexia ». Visual Neuroscience 12, n^o 1 (janvier 1995) : 153–63. http://dx.doi.org/10.1017/s0952523800007380.

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AbstractContrast sensitivity was determined for dyslexic and normal readers. When testing with temporally ramped (i.e. stimuli with gradual temporal onsets and offsets) gratings of 0.6, 4.0, and 12.0 cycles/deg, we found no difference in contrast sensitivity between dyslexic readers and controls. Using 12.0 cycles/deg gratings with transient (i.e. abrupt) onsets and offsets, we found that dyslexic individuals had, compared to controls, markedly inferior contrast sensitivity at the shortest stimulus durations (i.e. 17, 34, and 102 ms). This deficit may reflect more sluggish temporal summation. There was no difference in sensitivity to 0.6 cycles/deg gratings with transient onsets and offsets. Under these conditions, the two groups showed a consistent and equal increase in sensitivity relative to the ramped baseline condition at 0.6 cycles/deg at the longer stimulus durations. This demonstrates that dyslexic readers have no deficit in their ability to detect stimulus transients, a finding which appears to be inconsistent with a transient system deficit. That detection of the low-frequency stimuli was mediated by the transient system is further indicated by the fact that these stimuli were more susceptible to forward masking than were the high-frequency stimuli. The effects of masking of both high and low spatial-frequency stimuli were about equal for dyslexic readers and controls. This is not in agreement with the transient system deficit theory, according to which one would expect there to be less masking of high spatial-frequency stimuli in the case of dyslexic readers.

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Jang, Chang-Doo, Ho-Kyung Kim et Yun-Sok Ha. « Prediction of Plate Bending by High-Frequency Induction Heating ». Journal of Ship Production 18, n^o 04 (1 novembre 2002) : 226–36. http://dx.doi.org/10.5957/jsp.2002.18.4.226.

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In this study, we developed an analysis method of plate forming by induction heating and verified the effectiveness of the present method through a series of experiments. The phenomena of induction heating is a 3-D transient problem coupled with electromagnetic, heat transfer, and elastoplastic large-deformation analyses. To solve the problem, we suggest a proper model and an integrated system. Using the present analysis model, we can estimate the plate deformation in heating without experiments and simulate the plate bending process of induction heating. A series of induction heating experiments was carried out with various heating conditions such as plate thickness, heat speed, and input power. We measured the transient thermal distribution and final configuration of the plates, and acquired useful data to identify the characteristics of the high-frequency induction heating and for comparison with the analysis results.

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Pannila, Earl A. R. L., et Mahesh Edirisinghe. « Characterization of Switching Transients in Low Voltage Power Systems of Tea Factories in Sri Lanka ». European Journal of Electrical Engineering 22, n^o 4-5 (30 octobre 2020) : 325–34. http://dx.doi.org/10.18280/ejee.224-504.

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Voltage transients caused by various motors and electrical equipment of tea factories in Sri Lanka have been observed and analyzed. While reporting the major components of transients, this work extends it aspires to investigate the risk of having faults in a three-phase induction motor by monitoring and analyzing the transient voltage waveforms during the starting period. Therefore, common mode transient investigations have been followed. Transient voltage signals have been obtained from high end test setup and altogether 588 waveforms have been analyzed in both the time and frequency domains. In DOL and Star-Delta starting, highest transient amplitude of 688.2 V and 572.1 V have been observed respectively. Highest transient amplitude of 976.4 V and 980.5 V were observed in DOL and Star-Delta switching respectively. Withering and rolling sections dominates over other stages, generating high amplitude transients in average, reflecting same endangerment in energy calculations as presented in voltage integral. DOL starting transients carries fast rise times as 14 ns and in Star-Delta it is 28 ns. In order to assist with the exegesis of these data, transient parameters like rise time, duration, highest peak, etc.… have also been presented in statistical basis.

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Cargill, S. M., et D. G. Edwards. « Corona screen effectiveness in large machines under high voltage, high frequency transient conditions ». IEE Proceedings - Electric Power Applications 145, n^o 5 (1998) : 469. http://dx.doi.org/10.1049/ip-epa:19982162.

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Baumann, Markus, Christian Koch et Stephan Staudacher. « Application of Neural Networks and Transfer Learning to Turbomachinery Heat Transfer ». Aerospace 9, n^o 2 (20 janvier 2022) : 49. http://dx.doi.org/10.3390/aerospace9020049.

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Model-based predictive maintenance using high-frequency in-flight data requires digital twins that can model the dynamics of their physical twin with high precision. The models of the twins need to be fast and dynamically updatable. Machine learning offers the possibility to address these challenges in modeling the transient performance of aero engines. During transient operation, heat transferred between the engine’s structure and the annulus flow plays an important role. Diabatic performance modeling is demonstrated using non-dimensional transient heat transfer maps and transfer learning to extend turbomachinery transient modeling. The general form of such a map for a simple system similar to a pipe is reproduced by a Multilayer Perceptron neural network. It is trained using data from a finite element simulation. In a next step, the network is transferred using measurements to model the thermal transients of an aero engine. Only a limited number of parameters measured during selected transient maneuvers is needed to generate suitable non-dimensional transient heat transfer maps. With these additional steps, the extended performance model matches the engine thermal transients well.

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Holmberg, D. G., et T. E. Diller. « High-Frequency Heat Flux Sensor Calibration and Modeling ». Journal of Fluids Engineering 117, n^o 4 (1 décembre 1995) : 659–64. http://dx.doi.org/10.1115/1.2817319.

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A new method of in-situ heat flux gage calibration is evaluated for use in convective facilities with high heat transfer and fast time response. A Heat Flux Microsensor (HFM) was used in a shock tunnel to simultaneously measure time-resolved surface heat flux and temperature from two sensors fabricated on the same substrate. A method is demonstrated for estimating gage sensitivity and frequency response from the data generated during normal transient test runs. To verify heat flux sensitivity, shock tunnel data are processed according to a one-dimensional semi-infinite conduction model based on measured thermal properties for the gage substrate. Heat flux signals are converted to temperature, and vice versa. Comparing measured and calculated temperatures allows an independent calibration of sensitivity for each data set. The results match gage calibrations performed in convection at the stagnation point of a free jet and done by the manufacturer using radiation. In addition, a finite-difference model of the transient behavior of the heat flux sensor is presented to demonstrate the first-order response to a step input in heat flux. Results are compared with shock passing data from the shock tunnel. The Heat Flux Microsensor recorded the heat flux response with an estimated time constant of 6 μs, which demonstrates a frequency response covering DC to above 100 kHz.

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Nikanorov, Aleksandr, Egbert Baake et Jörg Neumeyer. « Numerical Simulation and Investigation of High Frequency Tube Welding Process ». Applied Mechanics and Materials 698 (décembre 2014) : 245–50. http://dx.doi.org/10.4028/www.scientific.net/amm.698.245.

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Welding processes and installations used nowadays are mainly developed on practical experience and analytical calculations. Nevertheless, high frequency induction tube welding is a very complex three-dimensional dynamic process, where the electromagnetic and thermal characteristics are distributed not only in space but in time as well. A more profound detailed investigation of the induction tube welding process can be only done by numerical modeling. Full and local three-dimensional transient numerical models of induction tube welding process with continuous movement of the welded tube have been developed and tested. Coupled electromagnetic and thermal analyses are carried out at each time step of simulation for correction of temperature dependent material properties. Voltage or current of the induction coil can be individually input into electromagnetic analysis at each time step. This approach allows simulating “quasi” steady-state and transient operation modes.

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Zaunschirm, Markus, Joshua D. Reiss et Anssi Klapuri. « A Sub-Band Approach to Modification of Musical Transients ». Computer Music Journal 36, n^o 2 (juin 2012) : 23–36. http://dx.doi.org/10.1162/comj_a_00117.

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The transient modifier is a type of audio effect that changes the level of the transient parts in a musical signal while leaving the steady-state parts unchanged. This article presents a high-performance algorithm for transient detection and modification, one that is capable of modifying transients in polyphonic or multi-voiced signals, and capable of modifying both hard (percussive) and soft (non-percussive) transients. The detection and modification of transients are performed in the frequency-domain using a sub-band approach. Detection is based on both phase and energy information using an adaptive threshold, and modification is carried out independently at each sub-band. The performance of the proposed sub-band approach was compared with other transient-modification algorithms using subjective listening tests. We show that the sub-band approach with adaptive threshold mostly outperforms other approaches.

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Hatanaka, Yoshihiro, Mutsuo Nakaoka et Toru Maruhashi. « Frequency doubler type SIT high frequency inverter and its transient and steady-state characteristics analysis. » IEEJ Transactions on Industry Applications 107, n^o 4 (1987) : 503–10. http://dx.doi.org/10.1541/ieejias.107.503.

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Marston, Philip L., et Scot F. Morse. « Time-frequency analysis of transient high-frequency dispersive guided waves on tilted cylindrical shells : Review ». Journal of the Acoustical Society of America 133, n^o 5 (mai 2013) : 3436. http://dx.doi.org/10.1121/1.4806065.

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Braña, L., A. Costa et R. Lopes. « Development of a power transformer model for high-frequency transient phenomena ». Renewable Energy and Power Quality Journal 19 (septembre 2021) : 217–21. http://dx.doi.org/10.24084/repqj19.260.

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In recent years, the proliferation of distributed renewable energy sources and the application of new rules for the exploitation of electrical networks imposed by the markets have dictated increasingly demanding operating conditions for electric power transformers, creating new challenges in their exploration and conservation. Transformers that, in addition to the transmission lines, are certainly the most important and critical element of any electrical energy system. Adequate models are necessary to accurately describe transformer behavior and internal response when submitted to different external requests imposed by the network, particularly during transient phenomena, as well as, to properly assess system vulnerabilities and network optimization. This effort is being carried out today by several research groups in the world, namely from Cigré and IEEE. In this work, a transformer model to be integrated into a timedomain equivalent circuit is developed and discussed. Results obtained with this model are compared with measurements obtained by the Cigré JWG A2/C4.52 in a power transformer used as a reference for the working group.

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Whitmore, Stephen A., Matthew D. Wilson et Shannon D. Eilers. « Novel Technique for Reconstructing High-Frequency Transient Rocket Chamber-Pressure Measurements ». Journal of Spacecraft and Rockets 47, n^o 3 (mai 2010) : 427–41. http://dx.doi.org/10.2514/1.46386.

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Zatloukalova, Jana, et Kay Raum. « High frequency ultrasound assesses transient changes in cartilage under osmotic loading ». Mathematical Biosciences and Engineering 17, n^o 5 (2020) : 5190–211. http://dx.doi.org/10.3934/mbe.2020281.

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Liu, Ziwei, Hongtao Su et Qinzhen Hu. « Transient interference suppression for high‐frequency skywave over‐the‐horizon radar ». IET Radar, Sonar & ; Navigation 10, n^o 8 (octobre 2016) : 1508–15. http://dx.doi.org/10.1049/iet-rsn.2015.0639.

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Jagtap, Sharayu, Saurabh Anmadwar, Sivaramakrishna Rudrapati et Shalabh Gupta. « A Single-Event Transient-Tolerant High-Frequency CMOS Quadrature Phase Oscillator ». IEEE Transactions on Nuclear Science 66, n^o 9 (septembre 2019) : 2072–79. http://dx.doi.org/10.1109/tns.2019.2935176.

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Moo, Chin-Sien, Kuo-Hsing Lee et Hau-Chen Yen. « Profiling Starting Transient of Fluorescent Lamp With High-Frequency Electronic Ballast ». IEEE Transactions on Plasma Science 37, n^o 12 (décembre 2009) : 2353–58. http://dx.doi.org/10.1109/tps.2009.2033072.

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Xie, Miaoxia, Hualing Chen et Jiu Hui Wu. « Transient energy density distribution of a rod under high-frequency excitation ». Journal of Sound and Vibration 330, n^o 12 (juin 2011) : 2701–6. http://dx.doi.org/10.1016/j.jsv.2011.02.028.

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Reynolds, R. R., B. D. Provencher et S. A. Shesterikov. « The high frequency, transient response of a panel with attached masses ». Journal of Sound and Vibration 266, n^o 4 (septembre 2003) : 833–46. http://dx.doi.org/10.1016/s0022-460x(02)01449-9.

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Jia, Ke, Qijuan Zhao, Zhengxuan Zhu et Tianshu Bi. « Modeling of DC Distribution System Based on High Frequency Transient Components ». IEEE Transactions on Smart Grid 12, n^o 1 (janvier 2021) : 671–79. http://dx.doi.org/10.1109/tsg.2020.3014360.

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Xie, Jia Wei, Gui Hong Bi, Shi Long Chen et Jie Zhang. « A Earth Fault Section Identification Method Based on ANN ». Advanced Materials Research 1006-1007 (août 2014) : 913–18. http://dx.doi.org/10.4028/www.scientific.net/amr.1006-1007.913.

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The method to discriminate the fault within or beyond the protective zone according to the signals with high frequency detected in protection has problem with low reliability when the resistance of earth fault is high. The transient voltage with low frequency detected in protection can reflect the size of fault intensity approximately, and the transient voltage with high frequency detected in protection in internal fault is bigger than that in external fault when the size of fault intensity is same. The high frequency transient voltage and low frequency transient voltage detected in protection are chosen as inputs and fault section as outputs for training and testing the neural network for fault identification in the UHVDC transmission line, fault section can be identified when input fault characteristic data to the trained model. A variety of transmission line earth fault situation are simulated by PSCAD, and this earth fault section identification method based ANN shows satisfactory performance, even the fault resistance is high.

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Et. al., R. Durga Rao,. « Nanocrystalline based Mitigation Technique for Very Fast Transient over Voltages in Gas Insulated Substations ». Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, n^o 2 (10 avril 2021) : 1025–39. http://dx.doi.org/10.17762/turcomat.v12i2.1117.

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: in gas insulated substations, issue of very fast transient over voltages is very familiar problem because of its effects on live ultra-high voltage equipment. During switching events of disconnectors and circuit breakers prestrikes and restrikes occur due to which voltage transients propagate through gas insulated switchgear. Reflection retraction of these transients increases voltage magnitude and generates very high frequency oscillations. Mitigation or suppression of these voltage transients is important to protect equipment and their dielectric strength and insulation. Due to very high frequency stress, they wield on the apparatus and their magnitude (up to 3.5pu), they create an important problem in the design of ultra-high voltage Gas Insulated Substations. In this paper nanocrystalline based mitigation technique for VFTOs is presented. Nanocrystalline rings can be placed around inner conductor of GIS switchgear. This method of mitigation technique is investigated with four ultra-high voltage substations simulation test setup. Simulation results are presented in MATLAB/SIMULINK

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Blythe, Sarah N., Jeremy F. Atherton et Mark D. Bevan. « Synaptic Activation of Dendritic AMPA and NMDA Receptors Generates Transient High-Frequency Firing in Substantia Nigra Dopamine Neurons In Vitro ». Journal of Neurophysiology 97, n^o 4 (avril 2007) : 2837–50. http://dx.doi.org/10.1152/jn.01157.2006.

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Transient high-frequency activity of substantia nigra dopamine neurons is critical for striatal synaptic plasticity and associative learning. However, the mechanisms underlying this mode of activity are poorly understood because, in contrast to other rapidly firing neurons, high-frequency activity is not evoked by somatic current injection. Previous studies have suggested that activation of dendritic N-methyl-d-aspartate (NMDA) receptors and/or G-protein-coupled receptor (GPCR)-mediated reduction of action potential afterhyperpolarization and/or activation of cation channels underlie high-frequency activity. To address their relative contribution, transient high-frequency activity was evoked using local electrical stimulation (1 s, 10–100 Hz) in brain slices prepared from p15–p25 rats in the presence of GABA and D2 dopamine receptor antagonists. The frequency, pattern, and morphology of action potentials evoked under these conditions were similar to those observed in vivo. Evoked activity and reductions in action potential afterhyperpolarization were diminished greatly by application of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) or NMDA receptor selective antagonists and abolished completely by co-application of AMPA and NMDA antagonists. In contrast, application of glutamatergic and cholinergic GPCR antagonists moderately enhanced evoked activity. Dendritic pressure-pulse application of glutamate evoked high-frequency activity that was similarly sensitive to antagonism of AMPA or NMDA receptors. Taken together, these data suggest that dendritic AMPA and NMDA receptor-mediated synaptic conductances are sufficient to generate transient high-frequency activity in substantia nigra dopamine neurons by rapidly but transiently overwhelming the conductances underlying action potential afterhyperpolarization and/or engaging postsynaptic voltage-dependent ion channels in a manner that overcomes the limiting effects of afterhyperpolarization.

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Iatcheva, Ilona, Georgi Gigov, Georgi Kunov et Rumena Stancheva. « Analysis of induction heating system for high frequency welding ». Facta universitatis - series : Electronics and Energetics 25, n^o 3 (2012) : 183–91. http://dx.doi.org/10.2298/fuee1203183i.

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The aim of the work is the investigation of induction heating system used for longitudinal, high frequency pipe welding.Coupled electromagnetic and temperature field distribution has been studied in order to estimate system efficiency and factors influencing the quality of the welding process and required energy. The problem was considered as three dimensional. Time harmonic electromagnetic and transient thermal field has been solved using finite element method and COMSOL 4.2 software package.

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Fukunaga, Shuhei, et Tsuyoshi Funaki. « Identification of High Resolution Transient Thermal Network Model for Power Module Packages ». Materials Science Forum 1062 (31 mai 2022) : 253–57. http://dx.doi.org/10.4028/p-90gl36.

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A transient thermal network model is utilized to design and evaluate the transient thermal characteristics of power modules. Static test method identifies the transient thermal network model from the time response of the junction temperature, which is obtained by using the temperature dependency of I-V characteristics for power devices. This paper experimentally evaluates the effect of the sampling frequency and the resolution of the AD conversion on the accuracy of the obtained transient thermal network model. The high sampling frequency and the high resolution in the obtained time response of the junction temperature enable to clearly identify the transient thermal network model of the power module with the direct bonding copper substrate.

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Shu, Hong Chun, Xin Cui Tian et Yue Tao Dai. « The Identification of Internal and External Faults for ±800kV UHVDC Transmission Line Based on S-Transform and SVM ». Advanced Materials Research 433-440 (janvier 2012) : 7138–44. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.7138.

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There is a smoothing reactor and DC filter between the inverter and the direct current line to form a boundary in the HVDC transmission system. Since this boundary presents the stop-band characteristic to the high frequency transient voltage signals, the high-frequency transient voltage signal caused by external faults through boundary will be attenuated and the signals caused by internal faults will be unchanged. In this paper, a new technique in which the combination of the S–transform and support vector machine (SVM) is used to analyze the transient signals, is proposed for distinguishing internal faults from the external faults based on the significantly difference of high-frequency transient voltage on the point of protection.

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Caulk, D. A. « A Method for Analyzing Heat Conduction With High-Frequency Periodic Boundary Conditions ». Journal of Heat Transfer 112, n^o 2 (1 mai 1990) : 280–87. http://dx.doi.org/10.1115/1.2910373.

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A special method is developed for calculating the steady periodic temperature solution in solid bodies with high-frequency boundary conditions. The numerical difficulty associated with steep gradients and rapid temperature variation near the boundary is addressed by confining all transient temperatures to a narrow boundary layer of constant depth. The depth of the layer is specified in advance and depends only on the period of the boundary disturbance and the thermal diffusivity of the material. The transient solution in the surface layer is represented by a polynomial in its transverse coordinate, with time-varying coefficients determined by a Galerkin method. This solution is coupled with the steady interior solution by imposing continuity of temperature and time-averaged heat flux at the interface. Although the method is sufficiently general to handle nonlinear boundary conditions, it turns out to be particularly useful in the important case of a time-varying heat transfer coefficient. In the latter case, it is possible to decouple the solution process and determine the solution in the transient surface layer separately from the solution in the steady interior. This reduces the effort of determining the complete steady periodic solution to little more than a routine steady analysis. Comparison with an exact solution shows that the polynomial representation for the transient solution in the surface layer converges very rapidly with increasing order. Moreover, the solution at the surface turns out to be relatively insensitive to the choice of the layer depth as long as it is greater than a certain minimum value. An application to permanent mold casting is given, illustrating both the utility and accuracy of the method in a practical context.

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Woods, N. M., K. S. R. Cuthbertson et P. H. Cobbold. « Phorbol-ester-induced alterations of free calcium ion transients in single rat hepatocytes ». Biochemical Journal 246, n^o 3 (15 septembre 1987) : 619–23. http://dx.doi.org/10.1042/bj2460619.

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The effect of the phorbol esters phorbol 12-myristate 13-acetate (TPA) and phorbol 12,13-dibutyrate (PDB) on changes in free Ca2+ concentration ([Ca2+]i) in single rat hepatocytes, microinjected with the photoprotein aequorin, were investigated. [Arg8]vasopressin and phenylephrine induced a series of repetitive [Ca2+]i transients. Phorbol esters inhibited the alpha 1-adrenoceptor-induced response; sub-nanomolar concentrations decreased the transient frequency, and higher concentrations abolished the transients. The inhibitory effect of PDB was readily reversible. Phorbol esters were less effective in decreasing the frequency of [Arg8]-vasopressin-induced transients, and the inhibition could be overcome by high [Arg8]vasopressin concentrations.

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Hatanaka, Yoshihiro, Matsuo Nakaoka et Toru Maruhashi. « Frequency doubler-type SIT high frequency inverter and analysis of its transient and steady-state characteristics ». Electrical Engineering in Japan 107, n^o 3 (1987) : 122–30. http://dx.doi.org/10.1002/eej.4391070314.

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Li, Sisi, Chun’en Fang, Lin Pan, Jiaojiao Duan et Junping Chen. « Research on measures suppressing high frequency transient overvoltage in offshore wind farms ». Journal of Physics : Conference Series 1983, n^o 1 (1 juillet 2021) : 012054. http://dx.doi.org/10.1088/1742-6596/1983/1/012054.

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Mardiana, Redy, Haifa Al Motairy et Charles Q. Su. « Ground Fault Location on a Transmission Line Using High-Frequency Transient Voltages ». IEEE Transactions on Power Delivery 26, n^o 2 (avril 2011) : 1298–99. http://dx.doi.org/10.1109/tpwrd.2010.2091327.

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Kohlhuber, Markus, et Marinus Luegmair. « Transient Ray Tracing Method for High Frequency Bending Waves in Complex Structures ». Acta Acustica united with Acustica 98, n^o 4 (1 juillet 2012) : 667–75. http://dx.doi.org/10.3813/aaa.918547.

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Harkema, Nathan, Alexander Plunkett et Arvinder Sandhu. « Tunable high-order frequency mixing for XUV transient absorption and photoelectron spectroscopies ». Optics Express 27, n^o 21 (11 octobre 2019) : 31053. http://dx.doi.org/10.1364/oe.27.031053.

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Jia, Ke, Zhefeng Ren, Lun Li, Zhenwen Xuan et David Thomas. « High-frequency transient comparison based fault location in distribution systems with DGs ». IET Generation, Transmission & ; Distribution 11, n^o 16 (9 novembre 2017) : 4068–77. http://dx.doi.org/10.1049/iet-gtd.2017.0426.

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Krimke, Ralf, Herbert M. Urbassek et Andreas Wucher. « High-frequency electron-gas secondary neutral mass spectrometry : evaluation of transient effects ». Journal of Physics D : Applied Physics 30, n^o 11 (7 juin 1997) : 1676–82. http://dx.doi.org/10.1088/0022-3727/30/11/017.

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Monaca, C., C. Ozsancak, L. Defebvre, S. Blond, A. Destée, J. D. Guieu et P. Derambure. « Transient insomnia induced by high-frequency deep brain stimulation in Parkinson disease ». Neurology 62, n^o 7 (12 avril 2004) : 1232–33. http://dx.doi.org/10.1212/01.wnl.0000118284.91103.bb.

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Cummings, A. « Transient and multiple frequency sound transmission through perforated plates at high amplitude ». Journal of the Acoustical Society of America 79, n^o 4 (avril 1986) : 942–51. http://dx.doi.org/10.1121/1.393691.

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Mousa, S., N. Harid, H. Griffiths et A. Haddad. « Experimental investigation of high frequency and transient performance of earth rod systems ». Electric Power Systems Research 113 (août 2014) : 196–203. http://dx.doi.org/10.1016/j.epsr.2014.03.024.

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