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Showing 1 to 20 of 29 for “"frequency sweep"”.
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Study Of Chaotic Ultrasound And Frequency Sweep Excitations In Sonic Ir Nde Technology
… physical process of two most important methods, frequency sweep excitation and chaotic excitation, to improve the defect detection ability of Sonic IR technology.</p> <p>The tool used in our study is known as finite element analysis (FEA). According to test process of Sonic IR technology, some …
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Adaptive methods for linear dynamic systems in the frequency domain with application to global optimization
… of the design and its modifications are frequency dependent matrices. Such matrices typically arise due to finite element analysis as well as other modeling techniques. Computing performance metrics related to steady-state forced response, also known as performing a frequency sweep, …
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Experimental Identification of Nonlinear Systems
… of multiple scales is used to determine the frequency-response function for the system. Experimental frequency- and amplitude-sweep data are compared with the prediction of the frequency-response function in a least-squares curve-fitting algorithm. The algorithm is improved by making use of …
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Ground electromagnetic experiments to investigate the possibility of using an airborne electromagnetic system to detect nuclear magnetic resonance associated with unbound water in the subsurface
… in the subsurface. If exposed to a radio-frequency pulse at the Larmor frequency, protons in water molecules create a magnetic eld oscillating at the Larmor frequency. Both surveys used a 120-second long frequency sweep from 2300 to 2400 Hz. It was initially hypothesized that as the …
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Thermoreflectance for Contactless Sintering Characterization: From Metal Nanoparticles to Stretchable Conductors
… and control. Here, we demonstrate that frequency-domain thermoreflectance (FDTR), an optical pump-probe technique, can be used for non-contact, non-destructive process monitoring that is compatible with high-throughput printed electronics manufacturing, unlike traditional electrical …
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Numerical modeling and ray tracing of SPatIal Frequency modulation for Imaging
… of a simple system that implements SPatIal Frequency modulation for Imaging (SPIFI). SPIFI utilizes a chirped frequency mask that modulates the intensity of light along a single axis at a linear frequency sweep giving each lateral position a unique spatial frequency. By taking the Fourier …
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The rigor bond’s interaction with protein denaturation : effects on water-holding of myofibrils
… of myofibrils was investigated as well by stress sweep and frequency sweep tests. The samples that were denatured without the presence of sarcoplasmic protein showed the poorest water-holding capacity which is indicating high drip loss in PSE like conditions mainly due to myofibrillar protein …
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Signal integrity analysis of high-speed multilayer interconnects using the finite element method
… the efficiency of the full-wave analysis, fast frequency sweep techniques and domain decomposition schemes are first investigated and then implemented. This work consists of four major parts. (1) The full-wave analysis is implemented based on the finite element method. The capability of handling …
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Acoustic Method for Detection Large Pneumothoraxes in the Out-of-Hospital Environment
… to a known acoustic input in the form of a frequency sweep and a low frequency square wave and the output signal was recorded at multiple points on the phantom. Analysis of four characteristics of the output revealed no discernable correlation to the volume or location of a pneumothorax. …
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Nonlinear Energy Harvesting With Tools From Machine Learning
… linear resonance work well only when excitation frequency is close to its natural frequency. While various control methods applied to an energy harvester realize resonant frequency tuning, they are either energy-consuming or exhibit low efficiency when operating under multi-frequency excitations. …
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Model-order reduction techniques for the numerical solution of electromagnetic wave scattering problems
… The ultimate goal is to enable a fast-sweep analysis. In a fast-sweep problem, some parameter on which the original problem depends is varying and the problem must be solved as the parameter changes over a desired parameter range. The complexity of the original model prohibits its …
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Real time water pipes leak detection using electromagnetic waves for the water industry
… to check for leaks. The simulation software High Frequency Structure Simulator (HFSS) was used to model the pipe section as a circular waveguide cavity, and also for antenna simulation. The monopole and loop antenna were designed to determine the best antenna for this project. The printed circuit …
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The feasibility of using EM waves in determining the moisture content and factors effecting measurements in building fabrics
… construction of an EM sensor operating at two frequency ranges: 2GHz to 6GHz and 6GHz to 12GHz at a power of 0dBm. This research is a new approach for monitoring moisture in buildings which has not been investigated before. The simulation software High Frequency Structure Simulator (HFSS) was …
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Studies on Functional and Rheological Characteristics of Hispanic Cheeses
… decreased significantly (P<0.05).<br /> A frequency sweep test was carried out at a constant stress of 100 Pa and data were best fitted into power-law model. Significant difference (P0.05) for low frequency viscous modulus ("c" value) among samples and months of storage.<br /> Five-element …
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Rheological Studies of Injectable Thermoresponsive Biodegradable Hydrogels and Porcine Ocular Tissues
… cornea, sclera and vitreous under strain and frequency sweep. All three tissue types at different stages have shown linear viscoelastic region under strain sweep. The G´ of cornea and vitreous weakly varied between neonatal and preterm, however, the adult cornea (~1.3-fold) and vitreous …
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Applied Aerial Autonomy for Reliable Indoor Flight and 3D Mapping
… Inertial parameters are estimated using frequency-domain linear system identification, incorporating control data from motor-speed sensing and state estimates from automated frequency sweep maneuvers. Additionally, drag-force coefficients and external wind are recursively estimated during …
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Optimal Vibration Suppression Using On-line Pole/Zero Identification
… a lookup table in the realtime controller, and a frequency sweep algorithm identifies the pole-zero spacing on-line and designs the PPF filters using the parameters in the lookup table. A Phase-Locked Loop (PLL) was also studied as a means for adaptively tuning the PPF filters on-line. The PLL …
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Frequency Domain Authentication Using Piezoelectric PZT Disks as Hardware IDs
… the response of its various entropy sources to a frequency sweep. Those entropy sources explored by this work are the admittance peak magnitudes, resonance frequencies, quality factor of the admittance peaks, impedance peak magnitudes, anti-resonance frequencies, and quality factor of the …
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Design and analysis of reconfigurable MIMO antennas for next generation wireless communication systems
… resolved effectively. Given the lower operating frequency of the new systems as compared to the WiFi and the existing cellular standards, the antennas in portable devices must be electrically small and are likely to be inefficient. It is also impractical to separate antennas to get low mutual …
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Nonlinear Dynamics of Energy Harvesting Ocean Buoys
… on forcing amplitudes, are discussed. Amplitude sweeps are conducted showing a dynamic bifurcation point that varies as a function of frequency and effective damping and experiments are run to validate computational results. </p><p>This system is examined further to study how it can be used …
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