Design of multiple-band filtering resonance devices at narrow frequency range using terahertz metamaterial resonator

2019 ◽  
Vol 453 ◽  
pp. 124368 ◽  
Author(s):  
Qingshan Niu ◽  
Chao Tang ◽  
Yuanhao He ◽  
Lifa Hu ◽  
Ben-Xin Wang
Keyword(s):  
Frequency Range ◽  
Multiple Band ◽  
Narrow Frequency Range

Alerting and Message Components in Songs of Rufous-Sided Towhees

Behaviour ◽  
1981 ◽  
Vol 76 (3-4) ◽  
pp. 223-249 ◽  
Author(s):  
Douglas G. Richards
Keyword(s):  
Signal Detection Theory ◽  
Field Experiments ◽  
Species Recognition ◽  
Defense Responses ◽  
Time Of Arrival ◽  
Sufficient Information ◽  
Passerine Birds ◽  
Frequency Range ◽  
Narrow Frequency Range ◽  
Species Specific

AbstractIn numerous species of passerine birds the initial few notes of the song have a narrow frequency range and wide temporal spacing when compared with the rest of the song. This structure is well adapted for high detectability when the song is acoustically degraded during passage through the environment. The song of the rufous-sided towhee (Pipilo eythrophtalmus) consists of relatively tonal introductory syllables followed by a complex rapid trill. The trill is capable of carrying more information than the introduction, but is inherently less detectable at a distance owing to degradation by reverberation, amplitude fluctuation, and frequency-dependent attenuation. Signal detection theory predicts that the detectability of the trill will be increased when it is preceded by the introductory syllables, owing to the removal of uncertainty concerning the time of arrival of the signal. This is alerted detection. I performed field experiments using playback of recorded song to towhees to test the hypothesis that these introductory syllables facilitate detection of conspecific song at a distance. Tape recordings of normal and artificially degraded full songs, introduction, and trills were played to territorial male towhees. Normal songs, degraded songs, and normal trills elicited strong territorial defense responses, indicating recognition as adequate species-specific song, and confirming that sufficient information is contained in the trill for species recognition. Degraded trills alone elicited little response. Both normal and degraded introductions also elicited little response, demonstrating that the increased response to a degraded full song over that to a degraded trill is not due to any species-specific characteristics of the introduction, but rather to its function as an alerting stimulus.

scholarly journals Multi-Frequency Synthesis

1991 ◽  
Vol 131 ◽  
pp. 171-179
Author(s):  
J. E. Conway
Keyword(s):  
Frequency Synthesis ◽  
Frequency Range ◽  
Image Fidelity ◽  
Narrow Frequency Range ◽  
Multiple Frequencies

AbstractA method of improving image fidelity by using observations at multiple frequencies is described. We discuss the power and possible limitations of the technique. Results of narrow frequency range observations with MERLIN and global VLBI are presented. We conclude with a consideration of the possible future impact of this technique.

Design of Discretely Tunable Resonant Actuators Using Additive Inertial Units

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Thomas W. Secord ◽  
Troy R. Louwagie ◽  
Robert J. Kopas
Keyword(s):  
General Framework ◽  
Voice Coil Motor ◽  
Energy Requirements ◽  
Frequency Range ◽  
Optimization Scheme ◽  
General Utility ◽  
Theoretical Design ◽  
Narrow Frequency Range ◽  
Resonant Actuators ◽  
Good Agreement

Abstract Resonance is known to reduce the input energy requirements of various actuator systems. The favorable effects of resonance, however, are limited to a narrow frequency range. To overcome this limitation, we describe a general framework for using discrete units of inertia that can be activated in a binary sense to move a resonant frequency across a desired frequency range. We also enumerate the generalized physical cases in which actuators can energetically benefit from resonance. We develop closed-form optimal results for the idealized case of two binary additive inertial units and extend this to a general optimization scheme for higher numbers of units that introduce parasitic friction and added stiffness. We illustrate the concept of binary tuning with a representative linear translational system powered by a voice coil motor (VCM). The experimental results show good agreement with the intended theoretical design and show the general utility of the binary additive inertia approach.

scholarly journals Optimal Design of a High Efficiency LLC Resonant Converter with a Narrow Frequency Range for Voltage Regulation

Energies ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 1124 ◽  
Author(s):  
Junhao Luo ◽  
Junhua Wang ◽  
Zhijian Fang ◽  
Jianwei Shao ◽  
Jiangui Li
Keyword(s):  
Optimal Design ◽  
High Efficiency ◽  
Voltage Regulation ◽  
Resonant Converter ◽  
Frequency Range ◽  
Llc Resonant Converter ◽  
Narrow Frequency Range

scholarly journals Overtone focusing in biphonic tuvan throat singing

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Christopher Bergevin ◽  
Chandan Narayan ◽  
Joy Williams ◽  
Natasha Mhatre ◽  
Jennifer KE Steeves ◽  
...  
Keyword(s):  
Sound Production ◽  
Vocal Tract ◽  
Low Frequency ◽  
Resonance Imaging ◽  
Frequency Range ◽  
Vocal Cords ◽  
Singing Style ◽  
Narrow Frequency Range ◽  
The Republic ◽  
Throat Singing

Khoomei is a unique singing style originating from the republic of Tuva in central Asia. Singers produce two pitches simultaneously: a booming low-frequency rumble alongside a hovering high-pitched whistle-like tone. The biomechanics of this biphonation are not well-understood. Here, we use sound analysis, dynamic magnetic resonance imaging, and vocal tract modeling to demonstrate how biphonation is achieved by modulating vocal tract morphology. Tuvan singers show remarkable control in shaping their vocal tract to narrowly focus the harmonics (or overtones) emanating from their vocal cords. The biphonic sound is a combination of the fundamental pitch and a focused filter state, which is at the higher pitch (1–2 kHz) and formed by merging two formants, thereby greatly enhancing sound-production in a very narrow frequency range. Most importantly, we demonstrate that this biphonation is a phenomenon arising from linear filtering rather than from a nonlinear source.

Microsphere Coupled Mach-Zehnder Interferometer for Biochemical Sensor

2013 ◽  
Vol 284-287 ◽  
pp. 2885-2889
Author(s):  
Yun Dong Zhang ◽  
Jing Zhang ◽  
He Tian ◽  
Ping Yuan
Keyword(s):  
Glucose Solution ◽  
Solution Concentration ◽  
Steep Slope ◽  
Frequency Range ◽  
High Quality ◽  
Interference Structure ◽  
Biochemical Sensor ◽  
Highly Sensitive ◽  
Narrow Frequency Range ◽  
Spectral Responses

We present the microsphere coupled Mach–Zehnder interference structure. We theoretically calculate that spectral responses of this structure vary with the glucose solution concentrations. It can produce the sharply asymmetric Fano resonance line shape related to the slope between zero and unity transmission. The variation of the normalized transmission is linearly related to the solution concentration. This structure is the promising highly sensitive biochemical sensor due to high quality factor resonance and steep slope over a very narrow frequency range

Masking of short stimuli by noises with spiked spectra: II. Time summation and frequency selectivity of hearing in a narrow frequency range

2011 ◽  
Vol 57 (2) ◽  
pp. 216-223 ◽  
Author(s):  
L. K. Rimskaya-Korsakova ◽  
M. R. Lalayants ◽  
A. Ya. Supin ◽  
G. A. Tavartkiladze
Keyword(s):  
Frequency Selectivity ◽  
Frequency Range ◽  
Narrow Frequency Range

Field Experiment of a Sonic Crystal Window

2018 ◽  
Vol 17 (04) ◽  
pp. 1850032 ◽  
Author(s):  
Hsiao Mun Lee ◽  
Long Bin Tan ◽  
Kian Meng Lim ◽  
Jinlong Xie ◽  
Heow Pueh Lee
Keyword(s):  
Field Experiment ◽  
White Noise ◽  
Sound Quality ◽  
Sitting Position ◽  
Frequency Range ◽  
National University ◽  
Sonic Crystal ◽  
Narrow Frequency Range ◽  
Recorded Data

In the present study, white, pink, construction and environmental noises were evaluated in a student hostel at National University of Singapore (NUS) with a newly designed sonic crystal (SC) window using sound quality head and torso simulator. The sound head was placed at the bed and the chair in the student hostel. All recorded data were analyzed into full (100–7000[Formula: see text]Hz) and narrow (700–1400[Formula: see text]Hz) frequency ranges. For lying position and for white noise, the SC window was able to attenuate extra 6.7 and 9.5[Formula: see text]dBA of noise compared to the existing glass louver window for full and narrow frequency ranges, respectively. For full frequency range, the overall amounts of pink, construction and environmental noises attenuated by the SC window were about 4.8, 5.0 and 3.4[Formula: see text]dBA, respectively. For narrow frequency range, the overall amounts of these three type of noises attenuated by the SC window were about 2–3.9[Formula: see text]dBA higher than that of full frequency range. The overall amounts of attenuated white noise at sitting position were about 2.6 and 6.1[Formula: see text]dBA, respectively, for full and narrow frequency ranges. For full frequency range, the attenuated pink and construction noises at sitting position were about 3.8 and 4.8[Formula: see text]dBA, respectively, which were slightly lower than that at lying position. However, for narrow frequency range, the attenuated noises obtained at lying position were 2.7 and 2.5[Formula: see text]dBA higher than that at sitting position for pink and construction noises, respectively.

Topological design of square lattice structure for broad and multiple band gaps in low-frequency range

2020 ◽  
Vol 35 ◽  
pp. 100632 ◽  
Author(s):  
Qian Cheng ◽  
Hui Guo ◽  
Tao Yuan ◽  
Pei Sun ◽  
Fengxiang Guo ◽  
...  
Keyword(s):  
Lattice Structure ◽  
Low Frequency ◽  
Band Gaps ◽  
Square Lattice ◽  
Frequency Range ◽  
Topological Design ◽  
Multiple Band

Selecting Filter Range of Hybrid Brain-Computer Interfaces by Mutual Information

2014 ◽  
Vol 981 ◽  
pp. 171-174 ◽  
Author(s):  
Li Wang ◽  
Xiong Zhang ◽  
Xue Fei Zhong ◽  
Zhao Wen Fan
Keyword(s):  
Mutual Information ◽  
Motor Imagery ◽  
Support Vector ◽  
Frequency Range ◽  
Fixed Frequency ◽  
Eeg Signals ◽  
Optimum Frequency ◽  
Computer Interfaces ◽  
Narrow Frequency Range ◽  
Better Than

The hybrid brain-computer interface (BCI) based on electroencephalography (EEG) become more and more popular. Motor imagery, steady state visual evoked potentials (SSVEPs) and P300 are main training Paradigms. In our previous research, BCI systems based on motor imagery can be extended by speech imagery. However, noise and artifact may be produced by different mental tasks and EEG signals are also different among users, so the classification accuracy can be improved by selecting optimum frequency range for each user. Mutual information (MI) is usually used to choose optimal features. After extracted the features from each narrow frequency range of EEG by common spatial patterns (CSP), the features are assessed by MI. Then, the optimum frequency range can be acquired. The final classification results are calculated by support vector machine (SVM). The average result of optimum frequency range from seven subjects is better than the result of a fixed frequency range.

Sign in / Sign up

Export Citation Format

Share Document