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Relevant bibliographies by topics / Main frequencies

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Academic literature on the topic 'Main frequencies'

Author: Grafiati

Published: 3 June 2025

Last updated: 31 July 2025

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Journal articles on the topic "Main frequencies"

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Levy, Yeshayahou, Asaf Modelevsky, Joseph Pismenny, Jens Friedrichs, and Detlev Wulff. "Links between Main Frequencies of Established Rotating Stall and Rotational Frequencies and/or Blade Passing Frequencies." International Journal of Rotating Machinery 2013 (2013): 1–11. http://dx.doi.org/10.1155/2013/283930.

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The ratios between the main frequency of rotating stall and rotational frequency may be considered in the form of exact ratios of small natural numbers if the pressure signals in compressors during rotating stall include the rotor rotation frequency component. During rotating stall in compressors with good rotor balancing (with absence of the rotational frequency component in the frequency characteristics of pressure signals), these ratios between the main frequency of rotating stall and rotational frequency are or are not in the form of ratios of small natural numbers. The experimentally rece

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Balona, L. A., D. L. Holdsworth, and M. S. Cunha. "High frequencies in TESS A–F main-sequence stars." Monthly Notices of the Royal Astronomical Society 487, no. 2 (2019): 2117–32. http://dx.doi.org/10.1093/mnras/stz1423.

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Abstract The driving mechanism for high-frequency oscillations in some chemically peculiar Ap stars, the rapidly oscillating Ap stars (roAp stars), is not understood. The Transiting Exoplanet Survey Satellite mission (TESS) data provide an ideal opportunity to extend the number of roAp stars that might provide further clues to address this problem. From an examination of over 18 000 stars in TESS sectors 1–7, we have discovered high-frequency pulsations in 14 A–F stars, of which only 3 are classified as Ap stars. In addition to these new discoveries, we discuss the frequencies in nine previous

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Ball, Warrick H., Jesper Schou, Laurent Gizon, and João P. C. Marques. "Precise and accurate interpolated stellar oscillation frequencies on the main sequence." Proceedings of the International Astronomical Union 9, S301 (2013): 379–80. http://dx.doi.org/10.1017/s1743921313014646.

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AbstractHigh-quality data from space-based observatories present an opportunity to fit stellar models to observations of individually-identified oscillation frequencies, not just the large and small frequency separations. But such fits require the evaluation of a large number of accurate stellar models, which remains expensive. Here, we show that global-mode oscillation frequencies interpolated in a grid of stellar models are precise and accurate, at least in the neighbourhood of a solar model.

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Mousavian, R., and M. Mashhadi Hossainali. "Detection of main tidal frequencies using least squares harmonic estimation method." Journal of Geodetic Science 2, no. 3 (2012): 224–33. http://dx.doi.org/10.2478/v10156-011-0043-6.

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AbstractIn this paper the efficiency of the method of Least Squares Harmonic Estimation (LS-HE) for detecting the main tidal frequencies is investigated. Using this method, the tidal spectrum of the sea level data is evaluated at two tidal stations: Bandar Abbas in south of Iran and Workington on the eastern coast of the UK. The amplitudes of the tidal constituents at these two tidal stations are not the same. Moreover, in contrary to the Workington station, the Bandar Abbas tidal record is not an equispaced time series. Therefore, the analysis of the hourly tidal observations in Bandar Abbas

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Sharma, M. K. "A Note on Main Effect Plans." Calcutta Statistical Association Bulletin 47, no. 1-2 (1997): 111–16. http://dx.doi.org/10.1177/0008068319970109.

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Method of construction of main effect plans (saturated and unsaturated) through BIB designs, using necessary and sufficient condition of proportional frequencies, is proposed. Using this condition, we obtain two new plans 216/18 and 225/27 not reported earlier. Utilising these plans, we have obtained two new asymmetrical orthogonal main effect plans.

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Gasperini, Paolo, Barbara Lolli, and Gianfranco Vannucci. "Relative frequencies of seismic main shocks after strong shocks in Italy." Geophysical Journal International 207, no. 1 (2016): 150–59. http://dx.doi.org/10.1093/gji/ggw263.

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Pshenichnyy, V. V., and A. F. Salnikov. "Vibration Dynamic Characteristics Simulation for Helicopter Main Gear Box Test Bench." Herald of the Bauman Moscow State Technical University. Series Mechanical Engineering, no. 3 (132) (June 2020): 18–28. http://dx.doi.org/10.18698/0236-3941-2020-3-18-28.

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New elements are usually used in developing promising products, and they are introduced to improve its characteristics. This study objective is aimed at making certain decisions to eliminate or reduce negative effects of design and technological solutions that are being identified only at the bench testing stage. Problem of resonant interactions between bench elements and main gear box units is connected to significant distortion of the product under development dynamic analysis results. Therefore, identifying resonant interaction conditions and obtaining reliable results in the course of deve

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Романовский, М. В., and А. И. Солдатов. "ACOUSTIC SIGNALS PROCESSING IN UNAUTHORIZED OPERATION ON THE MAIN PIPELINE." Proceedings in Cybernetics 23, no. 1 (2024): 60–67. http://dx.doi.org/10.35266/1999-7604-2024-1-8.

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The article demonstrates an approach for acoustic signal processing under conditions of unauthorized operation on the main pipeline. A case study included tests that simulated illegal pipeline tie-ins using metal pipe drilling. In the course of the study, acoustic signals were recorded and processed using the Fourier transform method. The fi ndings revealed the apexes of common frequencies for each test. The study aims to advance the protection of long-distance high-priority facilities from illegal actions by detecting any threat based on the common apexes of frequencies recorded during acoust

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Grigas, Gintautas, and Anita Juškevičienė. "Letter Frequency Analysis of Lithuanian and Other Languages Using the Latin Alphabet." Coactivity: Philology, Educology 23, no. 2 (2015): 81–91. http://dx.doi.org/10.3846/cpe.2015.271.

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It is important to evaluate specificities of alphabets, particularly the letter frequencies while designing keyboards, analyzing texts, designing games based on alphabets, and doing some text mining. In order to adequately compare lettter frequences of Lithuanian language to other languages in the Internet space, Wikipedia source was selected which content is common to different languages. The method of letter frequency jumps is used. The main attention is paid to the analysis of letter frequencies at the boundary between native letters and foreign letters used in Lithuanian and other language

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Fuchs-Hanusch, D., F. Friedl, R. Scheucher, B. Kogseder, and D. Muschalla. "Effect of seasonal climatic variance on water main failure frequencies in moderate climate regions." Water Supply 13, no. 2 (2013): 435–46. http://dx.doi.org/10.2166/ws.2013.033.

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The yearly water main failure frequency is a central performance indicator to describe the structural quality of a water distribution network. Besides age related deterioration, events such as severe climatic conditions or intensified third party construction may cause sudden seasonal increases in failure frequency trends. For the cold regions of Canada and the dry regions of Australia, several studies exist describing the impacts of climatic failure frequencies on water main failure variations. Failure prediction modelling applied to Austrian supply systems have shown that irregularities in o

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Dissertations / Theses on the topic "Main frequencies"

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Lin, Yong. "Database and algorithmic applications in nucleic acid sequence, structure and NMR frequencies, and an efficient chemical depiction." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2002. http://wwwlib.umi.com/cr/syr/main.

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Cooper, David. "Narrowband powerline communications on the domestic mains in the CENELEC frequencies." Thesis, University of Surrey, 2000. http://epubs.surrey.ac.uk/843671/.

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The object of this dissertation is to identify effective techniques for powerline communication using the low voltage (240V) domestic mains electricity supply in the sub 150 kHz frequency range as defined by the European CENELEC standard, concentrating on narrowband techniques suitable for low data rate telemetry applications. In order to conduct a comparison of communications techniques a model of the channel is invaluable. However a survey of the existing literature reveals that the presently available Knowledge of the channel characteristics and impairments of the low voltage mains is limit

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ALID, MOSTAFA. "Transmission de donnees sur canaux selectifs en frequence : application aux transmissions sur canal acoustique sous-marin." Rennes 1, 1993. http://www.theses.fr/1993REN10059.

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Le besoin de transmettre des donnees sur canal acoustique sous-marin horizontal (portee de quelques kilometres) par petites fonds (quelques dizaines de metres de hauteur d'eau) est ressenti, autant dans le domaine scientifique (collecte de donnees environnementales sous-marines) que par le grand public (communication entre plongeurs amateurs). Pour ce type de canal, la propagation des ondes acoustiques se fait en general suivant plusieurs trajets, attenues aleatoirement ou non (canal de rayleigh ou de rice) et affectes d'un effet doppler. Le produit de la dispersion temporelle des instants d'a

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Mechiche, Alami Omar. "Influence de la houle sur le rayonnement acoustique a tres basse frequence d'un corps sous-marin." Paris 6, 1992. http://www.theses.fr/1992PA066249.

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Comment une houle reguliere influence-t-elle le rayonnement acoustique d'un corps immerge lorsque la longueur d'onde de la houle et celle du son sont du meme ordre? pour une periode de houle de quelques secondes, ceci correspond a une frequence acoustique tres basse, de l'ordre de quelques hertz. Ce probleme est non lineaire. Cependant, les phenomenes physiques en jeu, acoustique et houle, que nous considerons etant de faible amplitude, nous developpons la solution du probleme en serie asymptotique. Il apparait ainsi un probleme au premier ordre ppo d'acoustique classique ignorant la houle et

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Books on the topic "Main frequencies"

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Space Telescope Science Institute (U.S.) and United States. National Aeronautics and Space Administration., eds. Radio and infrared properties of young stars. Space Telescope Science Institute, 1987.

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La Caze, Adam. Frequentism. Edited by Alan Hájek and Christopher Hitchcock. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199607617.013.17.

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This chapter introduces the key frequentist interpretation of probability as developed by Venn, von Mises and Reichenbach. Frequentists identify probabilities with frequencies; but there are problems with this identification. Finite frequentism is beset with problems, including the problem of the single case. Hypothetical frequentism, identifying probability with limiting relative frequencies in infinitely repeated trials, provides a response to the problems of finite frequentism and is consistent with the interpretation of probability in many areas of science. But identifying probability with

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Sogge, Christopher D. Hangzhou Lectures on Eigenfunctions of the Laplacian (AM-188). Princeton University Press, 2017. http://dx.doi.org/10.23943/princeton/9780691160757.001.0001.

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Based on lectures given at Zhejiang University in Hangzhou, China, and Johns Hopkins University, this book introduces eigenfunctions on Riemannian manifolds. The book gives a proof of the sharp Weyl formula for the distribution of eigenvalues of Laplace–Beltrami operators, as well as an improved version of the Weyl formula, the Duistermaat-Guillemin theorem under natural assumptions on the geodesic flow. The book shows that there is quantum ergodicity of eigenfunctions if the geodesic flow is ergodic. It begins with a treatment of the Hadamard parametrix before proving the first main result, t

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Parkin, Harry, ed. Concise Oxford Dictionary of Family Names in Britain. Oxford University Press, 2021. http://dx.doi.org/10.1093/acref/9780198868255.001.0001.

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Harry Parkin Over 43,000 entries ‘“What’s in a name?” Juliet asked as she and Romeo tried to puzzle their way around the troubling problem of their warring families. Well, plenty, the most detailed investigation into surnames in the UK and Ireland has found.’ Steven Morris, The Guardian (of The Oxford Dictionary of Family Names in Britain and Ireland) This new dictionary provides up-to date and authoritative explanations of family names found in Britain. It is an edited version of The Oxford Dictionary of Family Names of Britain and Ireland, published to great acclaim in 2016, which provided e

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Fermüller, Cornelia. Motion Illusions in Man and Machine. Oxford University Press, 2017. http://dx.doi.org/10.1093/acprof:oso/9780199794607.003.0006.

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At the level of mathematical abstraction, computing image motion amounts to an estimation problem and can be analyzed using the tools of statistics and signal processing. As shown in this chapter, intrinsic limitations to the estimation processes make it impossible to derive veridical estimates for all images. Image motion is estimated erroneously, and as a result higher level processes compute erroneous three-dimensional motion and moving scenes. Specifically, two limitations are discussed: (a) due to noise in image data, there is statistical bias that affects anisotropic patterns and (2) the

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Gleń-Karolczyk, Katarzyna. Zabiegi ochronne kształtujące plonowanie zdrowotność oraz różnorodność mikroorganizmów związanych z czernieniem pierścieniowym korzeni chrzanu (Atmoracia rusticana Gaertn.). Publishing House of the University of Agriculture in Krakow, 2019. http://dx.doi.org/10.15576/978-83-66602-39-7.

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Horseradish roots, due to the content of many valuable nutrients and substances with healing and pro-health properties, are used more and more in medicine, food industry and cosmetics. In Poland, the cultivation of horseradish is considered minor crops. In addition, its limited size causes horseradish producers to encounter a number of unresolved agrotechnical problems. Infectious diseases developing on the leaves and roots during the long growing season reduce the size and quality of root crops. The small range of protection products intended for use in the cultivation of horseradish generate

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Book chapters on the topic "Main frequencies"

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Tokarev, A. P., S. E. Spirin, and A. R. Valeev. "Determination of the Hydrodynamic Vibration Frequencies in the Main Pump Pipings." In Lecture Notes in Mechanical Engineering. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-85233-7_83.

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Bednarczyk, Bartosz, and Jakub Michaliszyn. "“Most of” leads to undecidability: Failure of adding frequencies to LTL." In Lecture Notes in Computer Science. Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-71995-1_5.

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AbstractLinear Temporal Logic (LTL) interpreted on finite traces is a robust specification framework popular in formal verification. However, despite the high interest in the logic in recent years, the topic of their quantitative extensions is not yet fully explored. The main goal of this work is to study the effect of adding weak forms of percentage constraints (e.g. that most of the positions in the past satisfy a given condition, or that $$\sigma $$ σ is the most-frequent letter occurring in the past) to fragments of LTL. Such extensions could potentially be used for the verification of inf

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Ming, Qiaohong, Yangyang Wang, and Meiyu Zong. "Research on EMC Simulation of Electric Drive System of Electric Engineering Machinery." In Lecture Notes in Mechanical Engineering. Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-1876-4_18.

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AbstractIn order to suppress the electromagnetic interference in electric construction machinery, improve the stability and safety of the vehicle on the influence factors of electric construction machinery EMC system analysis, electric drive system due to the internal power electronic equipment for a long time in the high voltage, high current conditions and become the main influence factors of electric construction machinery EMC. The main methods to reduce electromagnetic interference of electric drive system grounding, shielding and filtering are expounded, which leads to the emulated resear

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Zillner, Sonja. "Innovation in Times of Big Data and AI: Introducing the Data-Driven Innovation (DDI) Framework." In The Elements of Big Data Value. Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-68176-0_12.

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AbstractTo support the process of identifying and scoping data-driven innovation, we are introducing the data-driven innovation (DDI) framework, which provides guidance in the continuous analysis of factors influencing the demand and supply sides of a data-driven innovation. The DDI framework describes all relevant aspects of any generic data-driven innovation and is backed by empirical data and scientific research encompassing a state-of-the-art analysis, an ontology describing the central dimensions of data-driven innovation, as well as a quantitative and representative research study coveri

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Sharma, Surya Prakash, Shiva Shankar Choudhary, and Avijit Burman. "Nonlinear Dynamic Behaviour of Hollow Piles Based on Axial Harmonic Loading." In Lecture Notes in Civil Engineering. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2532-2_43.

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AbstractThe main objective of the current work is to examine the dynamic axial response of three pile group under machine-based harmonic loads. Field tests are carried out under axial harmonic excitations on a group pile with a pile length of 300 cm and an diameter of 11.4 cm in order to accomplish this objective. For various eccentric moments, the frequency versus amplitude responses of the group pile are measured. The field test results of the soil-pile system show non-linear behaviour as their resonant frequencies decrease and their resonant amplitudes disproportionally increase with eccent

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Munoz Lopez, Edwin J., and Alexander Hergt. "Experimental and Numerical Investigations of SBLI and Flow Control on a Transonic Compressor Cascade." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design. Springer Nature Switzerland, 2025. https://doi.org/10.1007/978-3-031-86605-0_14.

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Abstract The flow through a transonic compressor cascade is inherently unsteady due to the shock-boundary layer interactions (SBLI) on the blade. Despite decades of research, few details are known about the mechanisms that cause such behavior. This chapter presents a multidisciplinary study aiming to elucidate these mechanisms and optimize flow control methods to mitigate their effects. For this purpose, the Transonic Cascade TEAMAero was first optimized and its performance was validated experimentally. The cycle of shock oscillation was then compared using advanced experimental measurement te

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Matsunami, Koji, Kyoji Sassa, Ranjan Weerasinghe, Tania Munasinghe, and Loi Doan. "Challenges of Earthquake and Micro-Earthquake Monitoring in Sri Lanka." In Progress in Landslide Research and Technology. Springer Nature Switzerland, 2025. https://doi.org/10.1007/978-3-031-72736-8_6.

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AbstractSite amplification effects of Aranayake landslide area in Sri Lanka are analyzed using records observed by a wide dynamic-range earthquake motion array with soil- and rock-site stations. We find that the rock site on the mountain ridge does not have the same response as the rock site at the foot of mountain, which has a characteristic frequency-dependent site effect. The relative amplification of the mountain ridge rock site to the mountain foot rock site is nearly 1.0 at frequencies of 2 < f < 6 Hz, having a peak of 2 or more at 6 to 8 Hz, that gradually decreases with increasin

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Hastings, Mardi C., and Jeanette A. Thomas. "Fishes." In Exploring Animal Behavior Through Sound: Volume 2. Springer Nature Switzerland, 2025. https://doi.org/10.1007/978-3-031-83460-8_5.

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Abstract The term fishes is used broadly to include the eel-like, cartilaginous jawless fishes (Agnatha), the cartilaginous jawed fishes (Chondrichthyes), and the bony fishes (Osteichthyes). Among these groups, most bioacoustics research has focused on bony fishes, which generate communication sounds via the swim bladder and/or skeletal components. Fishes that have been studied in detail generally hear frequencies below 3000 Hz. The main functions of sounds emitted by fish are for intraspecific or interspecific aggression, defense of a territory or nest, attraction of a mate, and courtship. Al

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Cheng, Yuting, Christian Bizouard, Sébastien Lambert, and Jean-Yves Richard. "Hourly Earth Rotation Parameter Series from GPS and Galileo Observations, and Estimations of Tidal Effects." In International Association of Geodesy Symposia. Springer Berlin Heidelberg, 2024. http://dx.doi.org/10.1007/1345_2024_258.

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AbstractWe use the GINS/DYNAMO software to produce hourly time series of Earth Rotation Parameters (ERP) from 2017 to 2022. Data from the American constellation GPS and the European constellation Galileo are used. Single solutions and combined solutions are produced and analyzed. The best spectral coherence between constellations lies in the retrograde semi-diurnal band. We also perform least-squares adjustments for main tidal frequencies and compare with those of previous works. A sliding window analysis reveals time variation of amplitudes of several main tides when adjusting on a selected s

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Dove, Martin T. "Experimental Methods for Measurements of Vibrational Frequencies." In Structure and Dynamics: An Atomic View of Materials. Oxford University PressOxford, 2003. http://dx.doi.org/10.1093/oso/9780198506775.003.0010.

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Abstract The main experimental approach to study the structure of materials is through scattering of radiation, as was discussed in some depth in Chapter 6. It was noted that several different types of radiation beams can be used in diffraction, including electromagnetic radiation and beams of neutrons, each with its own relative merits. It is not surprising that scattering of radiation also proves to be one of the main techniques for studying dynamics. Nor is it surprising that, like in structural studies, there are several types of radiation that can be used, with each radiation type giving

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Conference papers on the topic "Main frequencies"

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Grewal, Anant, Sébastien Chapleau, Yann Pasco, and Alain Berry. "Active Control of Transmission Noise in a Bell 407 Helicopter." In Vertical Flight Society 70th Annual Forum & Technology Display. The Vertical Flight Society, 2014. http://dx.doi.org/10.4050/f-0070-2014-9415.

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Cabin noise is a major source of discomfort for helicopter passengers. One of the main sources of noise is the main rotor drive and gearbox assembly, whose structural vibrations are primarily transmitted through supporting struts and mounts to the airframe, which then radiates sound into the cabin. The vibration and resulting noise occur mainly at discrete gear meshing frequencies in the frequency range [1-3] kHz. The objective of this work was to establish the feasibility of an active control system to reduce multi-harmonic transmission noise in helicopter cabins. The system development, impl

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Rath, Tobias, and Walter Fichter. "A Closer Look at the Impact of Helicopter Vibrations on Ride Quality." In Vertical Flight Society 73rd Annual Forum & Technology Display. The Vertical Flight Society, 2017. http://dx.doi.org/10.4050/f-0073-2017-12047.

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The typical vibration level of helicopters is considerably higher than the levels found on fixed wing aircraft. The main reason for this are periodic airloads on the main rotor leading to elevated cabin vibrations at distinct frequencies equal to multiples of the main rotor speed. Thus, the development of technologies for vibration reduction mostly focuses on solutions that counteract the vibrations at rotor blade passage frequencies. As the reduction of those vibrations is performed efficiently, the question whether non-rotor induced vibrations are relevant for helicopter ride quality arises.

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Sute, Piyush, Prashant Verma, Tanmay Mathur, and Prabhat Hajela. "Multi-objective Design Optimization of a Helicopter Tail Shaft." In Vertical Flight Society 81st Annual Forum and Technology Display. The Vertical Flight Society, 2025. https://doi.org/10.4050/f-0081-2025-331.

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The paper describes a method for optimal design of a helicopter tail shaft that considers rotordynamic effects from long shaft assembly. The tail shaft transmits power from the main gearbox (MGB) to the tail rotor of the helicopter and operates at high speeds that may exceed 6000 rpm. While higher speeds allow for weight reduction, they also pose risks associated with supercritical operation, necessitating careful design optimization. The objective of the optimization is to maximize the first three transverse natural frequencies with the constraint of the safety parameter (avoidance of the res

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McKinnis, P., B. Miller, and A. Ruggles. "Interaction between main line standing waves and side branch resonance frequencies." In FLUID STRUCTURE INTERACTION/MOVING BOUNDARIES 2007. WIT Press, 2007. http://dx.doi.org/10.2495/fsi070311.

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Li, Yueyue, Sihua Xu, Jin He, Zhiqiang Hu, and Lei Xiao. "Numerical Investigation on the Vibration of Steam Turbine Main Inlet Control Valves Considering Fluid Force Effects." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-90419.

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Abstract In this paper, a finite element model (FEM) for inlet control valve was built and the structural modal analysis was performed to get the Eigen-frequencies of the valve. The valve plug as well as the stem together with piston rod and spring block were analyzed separately. Some peak frequencies of the main inlet control valves were obtained at the 2% lift case during warm-up stage on a nuclear power plant. The dynamic flow field as well as the steam forces were obtained by computational fluid dynamic (CFD) calculations with DES turbulence model. In order to clarify the cause of the valv

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Occhiuto, Scott F., David A. Jaquish, and George S. Duleba. "Vibration Testing at High Loads and Frequencies." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0375.

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Abstract This paper describes the design and conduct of high load, high frequency vibration tests of axially loaded brake rods used on typical aircraft landing gear. The main test objective was to evaluate damping characteristics of brake rods incorporating internal Coulomb damping. Tests were conducted with static and vibration loads combined at frequencies up to 350 Hz. Loads of 30,000 lb. static and ± 20,000 lb. dynamic were achieved. This combination of high static and dynamic loads at frequencies greater than 200 Hz is believed to never have been achieved before. This paper presents engin

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Pecinka, Ladislav, Petr Stulik, and Vladimir Zeman. "Dynamic Response of the WWER 1000/320 Reactor on the Pressure Pulsations Generated by Main Circulation Pumps." In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-77304.

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Dynamic response of all PWR reactors is generated by the turbulent pressure pulsations (TPP) in the boundary layer on the surface of core barrel and acoustic pressure pulsations (APP) generated by main circulation pumps (MCP). While TPP have character of the white noise in the frequency range 〈0; 35〉 Hz, APP generate discrete set of frequencies called revolution and blade frequencies. The rotor revolutions of individual MCPs are slightly different and are changing as the operation conditions are changing. It results in the varying beat character of reactor vibrations. Results of numerical simu

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Baek, Seung Il, and Savas Yavuzkurt. "Effects of Oscillations in the Main Flow on Film Cooling at Various Frequencies at a Low Blowing Ratio." In ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/gt2018-75440.

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The objective of this study was to investigate the effects of oscillations in the main flow on film cooling at various single frequencies at a low average blowing ratio of M = 0.5. The oscillations in the main flow could be a result of combustion instabilities that have been one of the major concerns for gas turbine industry. Understanding the effect of the instabilities on film cooling is important for better design of the gas turbine engines. The frequencies from 268 to 2144 Hz were identified as the dominant frequencies from a Fourier analysis of a combustor instability data on pressure osc

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Chakshu, Neeraj Kavan, and Sunil K. Sinha. "Natural Frequencies of Pre-Twisted Airfoil Blades." In ASME 2017 Gas Turbine India Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gtindia2017-4722.

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In this paper, the natural frequencies of pre-twisted cantilever blades of various angles of twist having different airfoil cross sections in the NACA 6 series have been determined. The main objectives of this paper are to replicate the results previously published for the similar types of blades but with the assumption of a uniform rectangular cross-section and to compare it with the results obtained for blades with more refined airfoil cross-sections. Cantilevered type clamped-free boundary conditions have been used in this paper for all blades. The comparison of the natural frequencies amon

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Ruskova, E. O., A. A. Maksimova, and M. S. Shushnov. "The main indicators of digital television broadcasting. Signal propagation in television broadcasting networks." In Modern Problems of Telecommunications - 2024. Siberian State University of Telecommunications and Information Systems, 2024. http://dx.doi.org/10.55648/spt-2024-1-204.

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Digital television broadcasting is a modern technology for transmitting images and sound using digital signals. The main indicators of digital television broadcasting include image and sound quality, data transfer rate, as well as the volume of frequencies used. Signal distribution in television broadcasting networks is carried out through satellite, cable and on-air broadcasts, providing wide audience access to content

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Reports on the topic "Main frequencies"

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Соловйов, Володимир Миколайович, V. Saptsin, and D. Chabanenko. Markov chains applications to the financial-economic time series predictions. Transport and Telecommunication Institute, 2011. http://dx.doi.org/10.31812/0564/1189.

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In this research the technology of complex Markov chains is applied to predict financial time series. The main distinction of complex or high-order Markov Chains and simple first-order ones is the existing of after-effect or memory. The technology proposes prediction with the hierarchy of time discretization intervals and splicing procedure for the prediction results at the different frequency levels to the single prediction output time series. The hierarchy of time discretizations gives a possibility to use fractal properties of the given time series to make prediction on the different freque

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Graziano, Alejandro, Georg Schaur, Christian Volpe Martincus, and Jerónimo Carballo. Transit Trade. Inter-American Development Bank, 2016. http://dx.doi.org/10.18235/0011742.

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In this paper, we estimate the effects of transit systems that substantiallystreamline administrative processing of trade flows. In so doing, we use a unique dataset that consists of the entire universe of El Salvador's export transactions over the period 2007-2013 and includes information on the transactions channeled under a new transit regime established with neighboring countries over the same period. Results suggest that this new transit system has been associated with decreased order servicing and variable trade costs. As a consequence, firms' exports increased primarily through higher s

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Jacobsen, Nils. Linjebussens vekst og fall i den voksende byen: en studie av bybussenes geografiske kvalitet Stavanger – Sandnes 1920 – 2010. University of Stavanger, 2019. http://dx.doi.org/10.31265/usps.244.

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Linear city bus services are facing increased challenges from city growth. Increased number of inhabitants on increasing acres of built-up areas, makes it demanding to maintain adequate bus services within reasonable catchment areas. Number of departures per hour give a partial description of the bus service quality. Number of departures give reference to the time aspect of bus service quality, but say nothing about the geographical aspect. What part of the entire line network is within reach of direct bus service when frequencies are limited? To address the geographical aspect of bus service

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Ortu, Fulvio, Pietro Reggiani, and Federico Severino. Persistence-based capital allocation along the FOMC cycle. CIRANO, 2024. http://dx.doi.org/10.54932/tuhb8180.

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The Federal Reserve holds two main sets of monetary policy meetings, the “Federal Open Market Committee” (FOMC) and the “Board Meetings”, which gather with sixweek and two week cadence respectively. Cieslak, Morse, and Vissing-Jorgensen (2019) show that the cadence of these meetings is associated with cycles of corresponding frequencies in stock markets. These can be fruitfully exploited through a portfolio strategy that invests in the whole market at alternate weeks (the even-week strategy). This simple investment rule is based on the cycles identified empirically but, so far, lacks a theoret

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Bernales, Rona P., and Ilene S. Basitan. Knowledge, Attitudes and Practices of Dog Owners Regarding Rabies and Dog Bites in Bicol Region. O.I.E (World Organisation for Animal Health), 2015. http://dx.doi.org/10.20506/standz.2790.

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This study was conducted in selected provinces of Bicol Region from April 2015 to May 2015 to describe the knowledge, attitudes and practices (KAP) of dog owners regarding rabies and dog bites. A purposive sampling was used in selecting the respondents of the study. Frequencies were tabulated for all variables. Of the 1,200 respondents, 2,193 dogs were recorded making a 2:1 ratio of dogs to householders in this particular study. Among these dogs 58% were vaccinated against rabies. The majority of the ones taking care of the dogs were female (57.3%) but the primary owner (62.9%) was the head of

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Achatz, Robert, and Roger Dalke. Man–made noise power measurements at VHF and UHF frequencies. Institute for Telecommunication Sciences, 2001. https://doi.org/10.70220/gxnlvbx1.

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Farahbod, A. M., and J. F. Cassidy. An overview of seismic attenuation in the Eastern Canadian Arctic and the Hudson Bay Complex, Manitoba, Newfoundland and Labrador, Nunavut, Ontario, and Quebec. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330396.

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In this study we investigated coda-wave attenuation (QC) from the eastern Canadian Arctic in Nunavut and the Hudson Bay complex including portions of northern Manitoba, Ontario, Quebec and Labrador. We used earthquake recordings from 15 broadband and 3 short period seismograph stations of the Canadian National Seismic Network (CNSN) and 29 broadband stations of the POLARIS network across the region. Our dataset is comprised of 637 earthquakes recorded between 1985 and 2021 with magnitudes ranging from 1.3 to 6.1, depths from 0 to 20 km and epicentral distances of 5 to 100 km. This gives a tota

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Deschamps, Robert, and Henschel. PR-420-133721-R01 Comparison of Radar Satellite Methods for Observation of Stability. Pipeline Research Council International, Inc. (PRCI), 2015. http://dx.doi.org/10.55274/r0010840.

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This report discusses the use of Synthetic Aperture Radar (SAR) satellites for monitoring above ground pipelines and buried pipeline Rights-Of-Way (ROWs) using Interferometric Synthetic Aperture Radar (InSAR) techniques. The main thrust of the research was to evaluate the suitability of above-ground pipeline support members as InSAR measurement points, and to adapt existing techniques to allow for precise monitoring of jacking and subsidence caused by permafrost degradation and dynamics. The study site at Prudhoe Bay, Alaska includes more than 60,000 horizontal pipeline supports. The known loc

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Turner, Nigel E., Nicolas Trajtenberg, Steve Cook, Olga Sanchez de Ribera, Jing Shi, and Henrietta Bowden-Jones. A health inequality examination of problem gambling, substance abuse, mental health, and poverty in the United Kingdom; A secondary analysis and stakeholder interviews. Greo Evidence Insights, 2023. https://doi.org/10.33684/2024.003.

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Purpose: This project is focused on the social determinants of health associated with problem gambling and examined gambling-related disparities and the determinants of negative health outcomes. Social determinants include social class education, ethnic group, age, and sex (Elton-Marshall, et al., 2017). The main aims of the study were as follows: Aim 1: In this study, we used the large data set to determine subpopulations who are experiencing social inequity (e.g., youth, older adults, women, Black people and other minority ethnic groups, and people with low income; see Elton-Marshall, et al.

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Tire Experimental Characterization Using Contactless Measurement Methods. SAE International, 2021. http://dx.doi.org/10.4271/2021-01-1114.

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In the frame of automotive Noise Vibration and Harshness (NVH) evaluation, inner cabin noise is among the most important indicators. The main noise contributors can be identified in engine, suspensions, tires, powertrain, brake system, etc. With the advent of E-vehicles and the consequent absence of the Internal Combustion Engine (ICE), tire/road noise has gained more importance, particularly at mid-speed driving and in the spectrum up to 300 Hz. At the state of the art, the identification and characterization of Noise and Vibration sources rely on pointwise sensors (microphones, accelerometer

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