Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 42 for “"dominant frequency"”.
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Resolving Small Objects Using Seismic Traveltime Tomography
… that the first Fresnel zone associated with the dominant frequency represents the spatial resolution limit of traveltime tomography. We show, however, that the relevant Fresnel limit for tomographic resolution is the maximum, not the dominant frequency in the data. For physically realizable …
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CFD Analyses of Flow Structures in Air-Ingress and Rod Bundle Problems
… For the air-ingress phenomenon, Brunt-Vaisala frequency, or buoyancy frequency, predicts a frequency of 2.34 Hz, which is confirmed by the dominant frequency of 2.4 Hz obtained from the wavelet analysis between times 1.2 s and 1.85 s. For the rod bundle study, the dominant frequency at the …
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Real Time Frequency Analysis of Signals From Lasso Catheter For Radiofrequency Ablation During Atrial Fibrillation
… obtained through lasso catheter during radiofrequency ablation of pulmonary vein was performed to determine the channel with dominant frequency. Threshold algorithm was used for signals which could be classified as type I and type II AF. Type III AF Signals which were highly fractionated or …
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Seismic data decomposition using sparse dictionary
… map 1D seismic trace into 2D plane of time and frequency. The decomposed frequency components of seismic trace are widely used to quantitatively predict the thickness of thin layers. The current popular time-spectrum analysis methods include the Short Time Fourier transform (STFT), Continuous …
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It’s Not Just a Phase: Real-Time Aeroelastic Flutter Control Optical Flow Sensing and Piezoelectric Control of Aeroelastic Flutter
… optical flow from live camera images; the dominant frequency (5.3–5.6 Hz) was identified using FFT analysis. A Hilbert transform obtained instantaneous waveform phase. Phase-locked square wave actuation (0–4.2 V, amplified 300×to 0–1260 V) was applied at the measured flutter frequency with …
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Amphibian communication: Coupling of acoustic systems to the medium at the air-water interface
… cm, re. 20 µPa) in air. In relation to air, the dominant frequency of the advertisement call (0.8 kHz) was the most intense spectral band underwater whereas the dominant frequency of the chuck (2.5 kHz in air) was less intense. The advertisement signal for the male túngara frog was broadcasted …
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Numerical Simulation of Three-Dimensional Aerodynamic Behavior of a Yawed, Inclined Circular Cylinder
… in this study. As yaw angle increases, the peak frequency of Cy deviates from the prediction by the Cosine Rule. The dominant frequency of Cx has a relatively low-frequency component and increases with yaw angle, but it cannot be predicted by the Cosine Rule. The comparison results indicate that …
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Effects of Anthropogenic Light and Noise on Anuran Breeding Behavior
… male’s call site. Call parameters including call dominant frequency, call duration, pulse rate, and call rate were analyzed for differences among urban and rural populations. Call site light microhabitat measurements were compared to the general light environment as well as among populations. …
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Enabling HF power conversion : magnetic components and a wide voltage range converter
High frequency switching in power converters offers the benefits of high power density and faster transient response; however, high frequency losses have limited efforts to increase frequency into the HF (3-30 MHz) regime. This thesis addresses two of the dominant frequency-dependent loss …
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ΜΕΛΕΤΗ ΔΑΚΤΥΛΙΟΕΙΔΟΥΣ ΔΙΦΑΣΙΚΗΣ ΡΟΗΣ ΣΕ ΟΡΙΖΟΝΤΙΟ ΑΓΩΓΟ
… QUANTITIES. THE POWER SPECTRA SHOW THAT THE DOMINANT FREQUENCY ASSOCIATED WITH LARGE WAVES IS <10 HZ AT LOW GAS VELOCITIES, DISPLAYING A TENDENCY TO INCREASE WITH GAS FLOW RATE. BY COMBINING SIGNAL CROSS-CORRELATION DATA WITH VISUAL OBSERVATIONS, IT IS SHOWN THAT THE DISTURBANCE WAVES TEND TO …
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Tuning of the middle ear in túngara frogs ( Engystomops pustulosus)
… using sound, animals have to hear well in the frequency range of their calls. In frogs, body size is a major predictor of both the dominant frequency of the mating call, and the frequency of best sensitivity of the ear, which tend to match each other. Various pathways are known to receive sound …
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Sound Production in Two Loricariid Catfishes
… by <em>P. gibbiceps</em> (20-200 ms). Mean dominant frequencies were approximately 4000 Hz for <em>M. affinis</em> and 1000 (abduction) and 4500 Hz (adduction) for <em>P. gibbiceps</em>. Light and scanning electron microscopy were used to examine the dorsal process of the pectoral spines …
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Padrão vocal de reconhecimento específico em Troglodytes musculus (Aves: Passeriformes: Troglodytidae) no Rio de Janeiro
… composed of trills of tonal notes with variable frequency modulation. Trills varied mainly in respect to frequency range and duration. Intersyllable interval and syllable duration were the less variable features of trills, while the minimum frequency and the variation of the frequency range …
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Vortex-induced motions of marine risers : straked force database extraction & transient response analysis
… conditions. In particular, we find that the frequency content of the riser response may be either narrow-banded around a single dominant frequency (Type I response) or distributed along a relatively broad range of frequencies (Type II response). Distinct transition from Type I to Type II …
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Finite Element Simulation of the MRTA Test of a Human Tibia
… (MRTA) tests long bone quality through low frequency, low amplitude vibration in vivo. The MRTA measures complex stiffness over a range of low frequencies, offering a wealth of information on bone composition. Previous MRTA interpretation used lumped parameter algorithms focused on reliably …
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Aspectos da morfologia e biologia de Scinax ruber (Laurenti, 1768) com comentários taxonômicos (Amphibia, Anura, Hylidae)
… with at least seven harmonics; 6) fundamental frequency of advertisement call at 500 Hz and dominant frequency equal to third harmonic; 7) encounter call composed of just one note, with harmonic structure more modulated than advertisement call; 8) fundamental frequency of encounter call ranging …
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Microperforated Panel (MPP) Absorbers for Impulsive and Narrow-Band Noise Control: Design, Simulation, and Experimental Validation
… due to the sport's distinct and repetitive mid-frequency “pop” sound. Conventional mitigation strategies, including porous absorbers, rigid barriers, and quiet paddles, have proven insufficient for addressing this specific acoustic challenge, especially in outdoor environments with oblique sound …
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Thermoacoustic Effects of a Variable Equivalence Ratio in a Single Element Methane Combustor
… a Fast Fourier Transform algorithm.</p> <p>The dominant frequencies, found to be between 1463 Hz and 1551 Hz, compare well with the experimental result of 1390 Hz, showing that the numerical model captured the primary acoustic modes of the combustor. However, the peak amplitudes of these …
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Distribuição sazonal e espacial de uma comunidade de anfíbios anuros associada a uma lagoa temporária do Distrito da Lapinha, Lagoa Santa (MG)
… between the notes, number of notes by call, and dominant frequency) revealed that the acoustic space was partitioned among the species of the community. Moreover, the seasonal and the spatial segregation were also important to the maintenance of the reproductive isolation.
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Surface Strain Measurement for Non-Intrusive Internal Pressure Evaluation of a Cannon
… pressure rise and has oscillation due to a dominant frequency of the barrel. A method to predict internal pressure from external tangential strain was developed. The internal pressure predicted is within 4% of the pressure applied in the model. A sensitivity study was performed to determine …
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