New underwater and aerial vocalizations of captive harp seals (Pagophilus groenlandicus)

2001 ◽  
Vol 79 (1) ◽  
pp. 75-81 ◽  
Author(s):  
A Serrano
Keyword(s):  
Fundamental Frequency ◽  
Breeding Season ◽  
High Frequency ◽  
Low Frequency ◽  
Time Of Day ◽  
Vocal Repertoire ◽  
Maximum Frequency ◽  
Pagophilus Groenlandicus ◽  
Vocal Activity ◽  
The Mean

Pinnipeds are ecologically and socially diverse, attributes that are reflected in their systems of communication. The purpose of this investigation was to document the vocal repertoire and annual cycle of vocal activity in the harp seal (Pagophilus groenlandicus), a species that communicates mainly under water, but whose social and communicative systems outside the breeding season are poorly known. The repertoire comprised 18 vocal classes, or call types; 7 that had not been described previously are described here. Vocal activity varied seasonally and with time of day. Calls of low frequency and with few pulse repetitions were predominantly used outside the breeding season, and calls of high frequency and with a high number of pulse repetitions predominated in the breeding season. The new vocalizations described here differed in several ways from those described previously. First, calls were relatively brief, with an average duration of 1.75 s (except call types 22 and 23, which averaged >2 s in duration). Second, some calls differed in mean fundamental frequency, the average being 677 Hz. Call types 22 and 23 differed the most, with an average of 838 Hz. The vocal repertoire described previously comprise calls with a fundamental frequency of approximately 400–500 Hz. Third, call types 22 and 25 differed from the rest of the vocalizations. The mean maximum frequency of call types 22 and 25 was 3.4 kHz, while the mean maximum frequency of the other call types is around 7.7 kHz.

A small vocal repertoire during the breeding season expresses complex behavioral motivations and individual signature in the common coot

BMC Zoology ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Changjian Fu ◽  
Atul Kathait ◽  
Guangyi Lu ◽  
Xiang Li ◽  
Feng Li ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Breeding Season ◽  
Function Analysis ◽  
Vocal Repertoire ◽  
Call Type ◽  
Temporal Parameters ◽  
Fulica Atra ◽  
Individual Signature ◽  
Behavioral Activities ◽  
Types Of Information

Abstract Background Although acoustic communication plays an essential role in the social interactions of Rallidae, our knowledge of how Rallidae encode diverse types of information using simple vocalizations is limited. We recorded and examined the vocalizations of a common coot (Fulica atra) population during the breeding season to test the hypotheses that 1) different call types can be emitted under different behavioral contexts, and 2) variation in the vocal structure of a single call type may be influenced both by behavioral motivations and individual signature. We measured a total of 61 recordings of 30 adults while noting the behavioral activities in which individuals were engaged. We compared several acoustic parameters of the same call type emitted under different behavioral activities to determine how frequency and temporal parameters changed depending on behavioral motivations and individual differences. Results We found that adult common coots had a small vocal repertoire, including 4 types of call, composed of a single syllable that was used during 9 types of behaviors. The 4 calls significantly differed in both frequency and temporal parameters and can be clearly distinguished by discriminant function analysis. Minimum frequency of fundamental frequency (F0min) and duration of syllable (T) contributed the most to acoustic divergence between calls. Call a was the most commonly used (in 8 of the 9 behaviors detected), and maximum frequency of fundamental frequency (F0max) and interval of syllables (TI) contributed the most to variation in call a. Duration of syllable (T) in a single call a can vary with different behavioral motivations after individual vocal signature being controlled. Conclusions These results demonstrate that several call types of a small repertoire, and a single call with function-related changes in the temporal parameter in common coots could potentially indicate various behavioral motivations and individual signature. This study advances our knowledge of how Rallidae use “simple” vocal systems to express diverse motivations and provides new models for future studies on the role of vocalization in avian communication and behavior.

A Novel Accelerometer Mounting Method for Sensing Performance Improvement in Acoustic Measurements From the Knee

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Goktug C. Ozmen ◽  
Mohsen Safaei ◽  
Lan Lan ◽  
Omer T. Inan
Keyword(s):  
Frequency Band ◽  
High Frequency ◽  
Low Frequency ◽  
Adhesive Tape ◽  
Spectral Centroid ◽  
Wearable Systems ◽  
Electrodynamic Shaker ◽  
3D Printed ◽  
The Mean ◽  
Sensing Performance

Abstract In this study, we propose a new mounting method to improve accelerometer sensing performance in the 50 Hz–10 kHz frequency band for knee sound measurement. The proposed method includes a thin double-sided adhesive tape for mounting and a 3D-printed custom-designed backing prototype. In our mechanical setup with an electrodynamic shaker, the measurements showed a 13 dB increase in the accelerometer's sensing performance in the 1–10 kHz frequency band when it is mounted with the craft tape under 2 N backing force applied through low-friction tape. As a proof-of-concept study, knee sounds of healthy subjects (n = 10) were recorded. When the backing force was applied, we observed statistically significant (p < 0.01) incremental changes in spectral centroid, spectral roll-off frequencies, and high-frequency (1–10 kHz) root-mean-square (RMS) acceleration, while low-frequency (50 Hz–1 kHz) RMS acceleration remained unchanged. The mean spectral centroid and spectral roll-off frequencies increased from 0.8 kHz and 4.15 kHz to 1.35 kHz and 5.9 kHz, respectively. The mean high-frequency acceleration increased from 0.45 mgRMS to 0.9 mgRMS with backing. We showed that the backing force improves the sensing performance of the accelerometer when mounted with the craft tape and the proposed backing prototype. This new method has the potential to be implemented in today's wearable systems to improve the sensing performance of accelerometers in knee sound measurements.

scholarly journals Краевые колебания нанолент графана

2018 ◽  
Vol 60 (5) ◽  
pp. 1029
Author(s):  
А.В. Савин
Keyword(s):  
Force Field ◽  
Frequency Spectrum ◽  
High Frequency ◽  
Low Frequency ◽  
Dispersion Curves ◽  
Linear Vibrations ◽  
The Mean

AbstractUsing the COMPASS force field, natural linear vibrations of graphane (graphene hydrogenated on both sides) nanoribbons are simulated. The frequency spectrum of a graphane sheet consists of three continuous intervals (low-frequency, mid-frequency, and narrow high-frequency) and two gaps between them. The construction of dispersion curves for nanoribbons with a zigzag and chair structure of the edges show that the frequencies of edge vibrations (edge phonons) can be present in the gaps of the frequency spectrum. In the first type of nanoribbons, two dispersion curves are in the low-frequency gap of the spectrum and four dispersion curves in the second gap. These curves correspond to phonons moving only along the nanoribbon edges (the mean depth of their penetration toward the nanoribbon center does not exceed 0.15 nm).

scholarly journals Performance Evaluation of Scalar Multiplication in Elliptic Curve Cryptography Implementation using Different Multipliers Over Binary Field GF (2233)

2020 ◽  
Vol 26 (9) ◽  
pp. 45-64
Author(s):  
Alaa Mohammed Abdul-Hadi ◽  
Yousraa Abdul-sahib Saif-aldeen ◽  
Firas Ghanim Tawfeeq
Keyword(s):  
Elliptic Curve Cryptography ◽  
Performance Index ◽  
High Frequency ◽  
Low Frequency ◽  
Scalar Multiplication ◽  
Maximum Frequency ◽  
Binary Field ◽  
Point Multiplication ◽  
Additional Layer ◽  
Different Types

This paper presents a point multiplication processor over the binary field GF (2233) with internal registers integrated within the point-addition architecture to enhance the Performance Index (PI) of scalar multiplication. The proposed design uses one of two types of finite field multipliers, either the Montgomery multiplier or the interleaved multiplier supported by the additional layer of internal registers. Lopez Dahab coordinates are used for the computation of point multiplication on Koblitz Curve (K-233bit). In contrast, the metric used for comparison of the implementations of the design on different types of FPGA platforms is the Performance Index. The first approach attains a performance index of approximately 0.217610202 when its realization is over Virtex-6 (6vlx130tff1156-3). It uses an interleaved multiplier with 3077 register slices, 4064 lookup tables (LUTs), 2837 flip-flops (FFs) at a maximum frequency of 221.6Mhz. This makes it more suitable for high-frequency applications. The second approach, which uses the Montgomery multiplier, produces a PI of approximately 0.2228157 when its implementation is on Virtex-4 (6vlx130tff1156-3). This approach utilizes 3543 slices, 2985 LUTs, 3691 FFs at a maximum frequency of 190.47MHz. Thus, it is found that the implementation of the second approach on Virtex-4 is more suitable for applications with a low frequency of about 86.4Mhz and a total number of slices of about 12305.

A generalized mean-field model of the natural and high-frequency actuated flow around a high-lift configuration

2009 ◽  
Vol 623 ◽  
pp. 283-316 ◽  
Author(s):  
DIRK M. LUCHTENBURG ◽  
BERT GÜNTHER ◽  
BERND R. NOACK ◽  
RUDIBERT KING ◽  
GILEAD TADMOR
Keyword(s):  
High Frequency ◽  
Field Model ◽  
Mean Field ◽  
Low Frequency ◽  
Navier Stokes ◽  
Mean Field Model ◽  
High Lift ◽  
The Mean ◽  
Generalized Mean ◽  
Low Dimensional

A low-dimensional Galerkin model is proposed for the flow around a high-lift configuration, describing natural vortex shedding, the high-frequency actuated flow with increased lift and transients between both states. The form of the dynamical system has been derived from a generalized mean-field consideration. Steady state and transient URANS (unsteady Reynolds-averaged Navier–Stokes) simulation data are employed to derive the expansion modes and to calibrate the system parameters. The model identifies the mean field as the mediator between the high-frequency actuation and the low-frequency natural shedding instability.

scholarly journals Evolution of low-frequency contribution in emission of steep-spectrum radio sources

2014 ◽  
Vol 11 (S308) ◽  
pp. 631-635
Author(s):  
Alla P. Miroshnichenko
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Radio Spectrum ◽  
Unified Model ◽  
Linear Size ◽  
Radio Sources ◽  
Mean Values ◽  
Spectrum Radio ◽  
Size Characteristic ◽  
The Mean

AbstractWe consider evolution properties of galaxies and quasars with steep radio spectrum at the decametre band from the UTR-2 catalogue. The ratios of source's monochromatic luminosities at the decametre and high-frequency bands display the dependence on the redshift, linear size, characteristic age of examined objects. At that, the mean values of corresponding ratios for considered galaxies and quasars have enough close quantities,testifying on the unified model of sources. We analyse obtained relations for two types of steep-spectrum sources (with linear steep spectrum (S) and low-frequency steepness after a break (C+)) from the UTR-2 catalogue.

scholarly journals Influence of Autonomic Control on the Specific Intermittent Performance of Judo Athletes

2018 ◽  
Vol 64 (1) ◽  
pp. 99-109
Author(s):  
Bruno T. Campos ◽  
Eduardo M. Penna ◽  
João G.S. Rodrigues ◽  
Mateus Diniz ◽  
Thiago T. Mendes ◽  
...  
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Training Experience ◽  
Specific Performance ◽  
Before And After ◽  
Post Test ◽  
Judo Athletes ◽  
The Mean ◽  
Hrv Analysis ◽  
Different Levels

Abstract Judo is a high-intensity intermittent combat sport which causes cardiac adaptations both morphologically and related to the autonomic nervous system (ANS). Therefore, this study aims to verify the correlation between heart rate variability (HRV) at rest with performance in the Special Judo Fitness Test (SJFT) and whether groups with different RR values at rest show different performance in the SJFT and during post-test recovery. Sixteen judo athletes with 7.2 ± 3.9 years of training experience participated in the study. Before and after the SJFT execution HRV and lactate measurements were conducted. For HRV analysis, we used the mean interval RR, the standard deviation of the RR interval (SDNN), the root mean square of successive differences in RR intervals (RMSSD), the low frequency (LF) and high frequency (HF) in normalized and absolute units. The sample was split into two groups (low RR and high RR) to verify if this variable could differentiate between specific performance. For the SDNN, a significant and moderate correlation (r = 0.53) was found with the total number of throws and throws in the series A (r = 0.56) and B (r = 0.54) and for the RMSSD a correlation with throws during series B (r = 0.59) in the SJFT. However, the groups did not differ in performance and recovery. Therefore, HRV is related to intermittent judo performance; however, it cannot differentiate between judokas at different levels of performance.

scholarly journals High-Frequency Conductive Hearing following Total Drum Replacement Tympanoplasty

2020 ◽  
Vol 162 (6) ◽  
pp. 914-921 ◽  
Author(s):  
Marc D. Polanik ◽  
Danielle R. Trakimas ◽  
Nicole L. Black ◽  
Jeffrey T. Cheng ◽  
Elliott D. Kozin ◽  
...  
Keyword(s):  
High Frequency ◽  
Care Center ◽  
Tertiary Care ◽  
Surgical Techniques ◽  
Case Series ◽  
Low Frequency ◽  
Temporalis Fascia ◽  
The Mean ◽  
Hearing Outcomes ◽  
Conductive Hearing

Objectives Conventional reporting of posttympanoplasty hearing outcomes use a pure-tone averaged air-bone gap (ABG) largely representing a low-frequency sound conduction. Few studies report high-frequency conductive hearing outcomes. Herein, we evaluate high-frequency ABG in patients following temporalis fascia total drum replacement. Study Design Case series with chart review. Setting Tertiary care center. Subjects and Methods All patients who underwent type 1 tympanoplasty using a lateral graft total drum replacement technique between August 2016 and February 2019 were identified. Patients with pre- and postoperative audiograms were included. Low-frequency ABG was calculated as the mean ABG at 250, 500, and 1000 Hz. High-frequency ABG was calculated at 4 KHz. Pre- and postoperative ABGs were compared. Results Twenty-three patients were included, and the mean age at surgery was 44 years (range, 9-68 years). Perforation etiology was from trauma (n = 14) or chronic otitis media (n = 9). Preoperative mean low-frequency ABG was 27.8 ± 12.6 dB and mean high-frequency ABG was 21.5 ± 15.1 dB ( P = .044). Postoperatively, the mean low-frequency ABG was significantly reduced by 15.5 ± 13.3 dB ( P < .001) while the mean high-frequency ABG insignificantly changed (reduced by 2.6 ± 16.2 dB, P = .450). Conclusion In a series of patients undergoing temporalis fascia total drum replacement, low-frequency ABG improved; however, high-frequency conductive hearing loss persists. Conventional methods of reporting ABG may not identify persistent high-frequency ABG. These results merit further study across a range of tympanoplasty graft materials and surgical techniques.

Potentiation of transmission at Ia-motoneuron connections induced by repeated short bursts of afferent activity

1985 ◽  
Vol 54 (6) ◽  
pp. 1541-1552 ◽  
Author(s):  
B. M. Davis ◽  
W. F. Collins ◽  
L. M. Mendell
Keyword(s):  
High Frequency ◽  
Afferent Fiber ◽  
Low Frequency ◽  
Mean Amplitude ◽  
Medial Gastrocnemius ◽  
Epsp Amplitude ◽  
Ia Afferent ◽  
Enhanced Transmission ◽  
Test Stimulation ◽  
The Mean

Single medial gastrocnemius Ia-afferent fibers and motoneurons to which they projected were simultaneously impaled in anesthetized cats. Each Ia-afferent fiber was electrically stimulated once every 2 s with short high-frequency bursts (32 shocks at 167 Hz) followed by 1-11 test shocks. The resulting motoneuron excitatory postsynaptic potentials (EPSPs) were recorded and averaged in register. The interval between the end of one burst and the beginning of the next was 2 s; therefore, the amplitude of the first EPSP in the burst was considered to be a measure of efficacy of transmission 2 s after the burst. At most connections (23/29) the mean amplitude of the first EPSP in the burst was equal to or larger than the mean amplitude of control EPSPs produced by low-frequency (18-Hz) stimulation. Enhancement of transmission was maximum 50-100 ms after the burst, and the amplitude of the test EPSP delivered at this time was always greater than that of the control. The period of enhanced transmission appeared to decay more rapidly at connections with small EPSPs. The greatest amount of EPSP amplitude enhancement at 50 or 100 ms after the burst was observed at connections at which EPSP amplitude increased during the burst. The shape (rise time, half width) of potentiated EPSPs was the same as control EPSPs averaged during low-frequency (18-Hz) stimulation. Multiple shocks delivered at low frequency between bursts revealed that enhanced transmission following the high-frequency burst is very sensitive to the effects of low-frequency test stimulation. Furthermore, increasing the number of shocks during the interval between bursts reduced the enhancement of the first EPSP in the burst. We suggest that modulation of synaptic transmission after high-frequency bursts differs across Ia-motoneuron connections. These time-dependent changes associated with short bursts of firing (which are similar in frequency to those observed in Ia-fibers supplying hind-limb muscles during stepping) emphasize the necessity to consider the history of the discharge pattern of the group Ia fiber in assessing efficacy at individual Ia-motoneuron connections.

Variations in broadband seismic noise at IRIS/IDA stations in the USSR with implications for event detection

1990 ◽  
Vol 80 (6B) ◽  
pp. 2072-2088 ◽  
Author(s):  
Holly K. Given
Keyword(s):  
Noise Reduction ◽  
High Frequency ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Time Of Day ◽  
Signal Frequency ◽  
Seasonal Effect ◽  
Noise Levels ◽  
Power Spectral ◽  
Lower Noise

Abstract Ambient noise conditions at four IRIS/IDA sites in the USSR are characterized from 0.01 to 100 Hz as part of a study to ascertain the utility of broadband three-component seismic stations in monitoring regional Eurasian seismicity. Estimates of the power spectral density of noise levels were computed for a 5-day period in two seasons (winter and summer), at two times of the day. Of these periods, lower noise conditions were found at night in the summer. In general, at 1 Hz and above, noise levels and their variations correlate predictably with the soundness of vault construction and the proximity of the station to civilization. Absolute noise levels at the IRIS/IDA/USSR sites range from a high of about −120 dB to a low of −155 dB relative to (1 m/s2)2/Hz, between 1 and 5 Hz. A time-of-day variation in noise was observed at all sites, with noise levels during the work day ranging from 7 to 14 dB higher than night levels, depending on the site. This effect was observed only for frequencies above about 1 Hz. Observed seasonal variations (winter versus summer) are highly station dependent, although the seasonal effect is restricted to frequencies below 1 Hz and is in general centered on the microseism peak (0.1 to 0.2 Hz). Below 0.1 Hz, noise levels are influenced by the thermal and barometric isolation of the site. Low-frequency levels were not studied below 0.01 Hz. Minimum detectable magnitudes are estimated for the IRIS/IDA stations using the observed noise levels over 1 Hz. In general, a magnitude 3 event should be detectable at 1,000 km by all stations under night noise conditions if the dominant signal frequency is 1 Hz; the magnitude estimates increase with increasing frequency. These detectability estimates assume a conservative signal-to-noise ratio of 6. High-frequency data recorded by independent equipment co-located with the IRIS/IDA system during a 2-week experiment allow estimation of noise levels at the sites up to 100 Hz. Borehole versus surface noise levels recorded during the high-frequency experiment showed significant noise reduction (20 dB) can be achieved by borehole deployment at sites with exposed surface vaults. With well-isolated surface vaults, borehole noise reduction is about a factor of 2. Absolute noise levels between 1 to 10 Hz observed at IRIS/IDA/USSR sites are systematically higher than average NORESS noise by about 7 dB to 25 dB, depending on the station.

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