Analysis of the Spatial-Frequency Characteristics of the Photo-Assisted Method of a Quartz Rough Surface Nano-Polishing by Vasyl Kanevskii, Serhii Kolienov, Valerii Grygoruk, Oleksandr Stelmakh, Hao Zhang

“…In particular, when the standard deviation is less than 1 nm, all surface protrusions, for which the spatial spectrum harmonics of the profile are located in the region of the maximum slope of the spectral function, are most actively etched. …”
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A New Design of Vibration Absorber for Periodic Excitation by Shyh-Chin Huang, Kao-An Lin

“…Since the periodic rather than single harmonic excitation is themost occurring case in mechanical systems, the design of PVA is hence of engineering significance. …”
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Modeling Femtosecond Beam Propagation in Dielectric Hollow-Core Waveguides by Valer Tosa, Ana Maria Mihaela Gherman, Katalin Kovacs, István Tóth

“…In particular, hollow-core waveguides (HCWs) filled with a gas medium are fabricated and used as devices for the generation of attosecond pulses from high-order harmonics. In this process, the configuration of the laser field (intensity and phase) inside the waveguide is of crucial importance for enhancing the (well-known, low) efficiency of high-order harmonic generation (HHG). …”
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Wave Attenuation and Dispersion in a 6 mm Diameter Viscoelastic Split Hopkinson Pressure Bar and Its Correction Method by Haotian Zhang, Linjian Ma, Zongmu Luo, Ning Zhang

“…The results indicate that the high-frequency harmonics attenuate faster in a higher phase velocity. …”
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The earth-fill dam state express investigation using mechanical vibrations produced by HPP by Galina Antonovskaya, Natalia Kapustyan

“…Such vibrations are monochromatic oscillations on main frequencies and their harmonics produced by turbine. Seismic sensors installed on the dam's crest and inside it, if it possible, and in the area of abutment contacts register microseisms include HPP turbine operation vibrations which may be extracted by seismic data processing, i.e., filtering. …”
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The earth-fill dam state express investigation using mechanical vibrations produced by HPP by Galina Antonovskaya, Natalia Kapustyan

“…Such vibrations are monochromatic oscillations on main frequencies and their harmonics produced by turbine. Seismic sensors installed on the dam's crest and inside it, if it possible, and in the area of abutment contacts register microseisms include HPP turbine operation vibrations which may be extracted by seismic data processing, i.e., filtering. …”
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Tunable High-Frequency Acoustoelectric Current Oscillations in Fluorine-Doped Single-Walled Carbon Nanotubes by Daniel Sekyi-Arthur, Samuel Yeboah Mensah, Kofi Wi-Adu, Kwadwo Anokye Dompreh, Raymond Edziah

“…Hypothetically, the energy of interaction between the carriers and the acoustic phonons is less than the energy of the typical carriers. High-order harmonics of the acoustic phonons’ effective field could be disregarded under this supposition. …”
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Revampment of surface permanent magnet synchronous motor design for ameliorated torque profile in e‐mobility applications by Anshul K. Mishra, Bharat S. Rajpurohit, Rajeev Kumar

“…In the next step, the design has been ameliorated by making it a fractional slot winding machine to suppress the winding harmonics. Finally, the effect of the permanent magnet embrace size on the torque ripple has been investigated. …”
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A novel sea surface evaporation scheme assessed by the thermal rotating shallow water model by Masoud Rostami, Stefan Petri, Bijan Fallah, Farahnaz Fazel‐Rastgar

“…The Dedalus algorithm, which handles spin‐weighted spherical harmonics, is employed to address the pseudo‐spectral problem‐solving tasks of the model.…”
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An Efficient Grid-tied Flyback Micro-inverter with DCM Control Strategy by Salam Jabr Yaqoob, Adel A. Obed

“…The proposed control is tested under different weather conditions for solar irradiance and temperature, as a result, a pure sin wave current has been injected into the grid with a lower harmonics value. Finally, the small size, low cost and high reliability of single stage flyback micro-inverter is presented without the need for DC/DC converter. …”
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Influences of Hydrodynamic Forces on the Identification of the Rotor-Stator-Rubbing Fault in a Rotating Machinery by Bernard Xavier Tchomeni, Desejo Filipeson Sozinando, Alfayo Alugongo

“…Finally, it is revealed that the instantaneous frequency extraction based on wavelet synchrosqueezing is a useful tool to identify the weak and hidden peak harmonics localised in the time-frequency maps of the fluid-rotor system.…”
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Analysis of Carbon Contents and Heavy Metals in Coal Samples Using Calibration-free LIBS Technique by Muhammad Aamir Israr, Qamar Abbas, Sami Ul Haq, Ali Nadeem

“…The coal samples were pelletized in the form of a disc and irradiated with a focused laser beam of fundamental (1064 nm) and second (532 nm) harmonics of Nd:YAG laser, which produced plasma on the sample surface. …”
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Design and Simulation of Power Quality Improvement System for Low Voltage Distribution Networks in Uganda. by Arinde, Francis

“…The design of reliable power filters that mitigate current and voltage harmonics to meet the power quality requirements of the utility grid is a major requirement of present-day power systems. …”
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Research on formant estimation algorithm for high order optimal LPC root value screening by Hua LONG, Shumeng SU

“…The 9-order linear prediction only preserves the basic shape of LP response amplitude spectrum of speech signal.When the order of LP is increased to the 15,the fitting degree of the signal is increased,and the zero and pole of LP is dense and the distribution of LP is closer to the unit circle.The 15th order LP compensates for the sacrifice of formant fitting accuracy caused by the 9th order linear fitting, which improves the formant extraction accuracy by 2.5%. (2) Using the threshold value under the constraint of digital resonance root value to determine the complex roots,the low frequency false roots generated by fundamental frequency harmonics and the false roots generated by formant harmonics is effectively filtered.The zeroes-poles of the LP polynomial are the complex roots corresponding to the formant peaks.In the view of the distribution of formant detection root values, the high-order LP root threshold constrained by digital formant root values can effectively filter the false roots generated by harmonic action of sound channel. …”
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Current Control and Active Damping for Single Phase LCL-Filtered Grid Connected Inverter by Mohammad Alshiekh, Alaa Marouf, Muhieddin Kubeitari

“…LCL filter has been widely used in the grid connected inverter, since it is effective in attenuation of the switching frequency harmonics in the inverter. However, the resonance in this filter causes stability problems and must be damped effectively to achieve stability. …”
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Receptivity of Boundary Layer over a Blunt Wedge due to Freestream Pulse Disturbances at Mach 6 by Jianqiang Shi, Xiaojun Tang, Zhenqing Wang, Mingfang Shi, Wei Zhao

“…In general, the amplitudes of both fundamental mode and harmonics become larger with the decreasing of freestream disturbance frequency. …”
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Music Signal Recognition Based on the Mathematical and Physical Equation Inversion Method by Wei Jiang, Dong Sun

“…The benchmark model demonstrates the positive correlation of pitch features on recognition through comparative experiments and explores the number of harmonics that should be attended to when recognizing different instruments. …”
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Stochastic Optimal Selection and Analysis of Allowable Photovoltaic Penetration Level for Grid-Connected Systems Using a Hybrid NSGAII-MOPSO and Monte Carlo Method by Ali Abubakar, Reindorf Nartey Borkor, Peter Amoako-Yirenkyi

“…However, due to the stochasticity and nondispatchable nature of its generation, significant adverse impacts such as power overloading, voltage, harmonics, current, and frequency instabilities on the utility grid arise. …”
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A New Fractal-Based Miniaturized Dual Band Patch Antenna for RF Energy Harvesting by Sika Shrestha, Seong Ro Lee, Dong-You Choi

“…In addition to miniaturization and dual band nature, the proposed antenna also removes unwanted harmonics without the use of additional filter component. …”
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Fault Detection of High-Speed Train Wheelset Bearing Based on Impulse-Envelope Manifold by Zhe Zhuang, Jianming Ding, Andy C. Tan, Ying Shi, Jianhui Lin

“…The analyzed results based on simulations, experimental tests, and practical applications show that (1) the impulse-envelope manifold with both isometric mapping (Isomap) and locally linear coordination (LLC) can be successfully used to extract the intrinsic envelope of the impulses where local tangent space analysis (LTSA) fails to perform and (2) the impulse-envelope manifold with Isomap outperforms those with LLC in terms of strengthening envelopes and the number of extracted harmonics. The proposed impulse-envelope manifold with Isomap is superior in extracting the intrinsic envelope, strengthening the amplitude of intrinsic envelope spectra, and enlarging the harmonic number of fault-characteristic frequency. …”
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