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Vibration Signals (vibration + signal)

Distribution by Scientific Domains
Life Sciences62%
Chemistry37%

Selected Abstracts

Intra-Patriline Variability in the Performance of the Vibration Signal and Waggle Dance in the Honey Bee, Apis mellifera

ETHOLOGY, Issue 7 2008
Nhi Duong
We examined intra-patriline behavioral plasticity in communication behavior by generating lifetime behavioral profiles for the performance of the vibration signal and waggle dance in workers which were the progeny of three unrelated queens, each inseminated with the semen of a single, different drone. We found pronounced variability within each patriline for the tendency to produce each signal, the ontogeny of signal performance, and the persistence with which individual workers performed the signals throughout their lifetimes. Within each patriline, the number of workers that performed each signal and the distribution of onset ages for each signal were significantly different. In each patriline, workers of all ages could perform vibration signals; vibration signal production began 3,5 d before waggle dancing; and some workers began performing waggle dances at ages typically associated with precocious foraging. Most workers vibrated and waggled only 1,2 d during their lifetimes, although each patriline contained some workers that performed the signal persistently for up to 8 or 9 d. We also found marked variability in signal performance among the three worker lineages examined. Because the vibration signal and waggle dance influence task performance, variability in signaling behavior within and between subfamilies may help to organize information flow and collective labor in honey bee colonies. Inter-patriline variability may influence the total number of workers from different partrilines that perform the signals, whereas intra-patriline variability may further fine-tune signal performance and the allocation of labor to a given set of circumstances. Although intra-patriline behavioral variability is assumed to be widespread in the social insects, our study is the first to document the extent of this variability for honey bee communication signals. [source]

Vibration signals from the FT joint can induce phase transitions in both directions in motoneuron pools of the stick insect walking system

DEVELOPMENTAL NEUROBIOLOGY, Issue 2 2003
Ulrich Bässler
Abstract The influence of vibratory signals from the femoral chordotonal organ fCO on the activities of muscles and motoneurons in the three main leg joints of the stick insect leg, i.e., the thoraco,coxal (TC) joint, the coxa,trochanteral (CT) joint, and the femur,tibia (FT) joint, was investigated when the animal was in the active behavioral state. Vibration stimuli induced a switch in motor activity (phase transition), for example, in the FT joint motor activity switched from flexor tibiae to extensor tibiae or vice versa. Similarly, fCO vibration induced phase transitions in both directions between the motoneuron pools of the TC joint and the CT joint. There was no correlation between the directions of phase transition in different joints. Vibration stimuli presented during simultaneous fCO elongation terminated the reflex reversal motor pattern in the FT joint prematurely by activating extensor and inactivating flexor tibiae motoneurons. In legs with freely moving tibia, fCO vibration promoted phase transitions in tibial movement. Furthermore, ground vibration promoted stance,swing transitions as long as the leg was not close to its anterior extreme position during stepping. Our results provide evidence that, in the active behavioral state of the stick insect, vibration signals can access the rhythm generating or bistable networks of the three main leg joints and can promote phase transitions in motor activity in both directions. The results substantiate earlier findings on the modular structure of the single-leg walking pattern generator and indicate a new mechanism of how sensory influence can contribute to the synchronization of phase transitions in adjacent leg joints independent of the walking direction. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 125,138, 2003 [source]

Nonintrusive characterization of fluidized bed hydrodynamics using vibration signature analysis

AICHE JOURNAL, Issue 3 2010
M. Abbasi
Abstract There are many techniques to characterize the hydrodynamics of fluidized beds, but new techniques are still needed for more reliable measurement. Bed vibrations were measured by an accelerometer in a gas,solid fluidized bed to characterize the hydrodynamics of the fluidized bed in a nonintrusive manner. Measurements were carried out at different superficial gas velocities and particle sizes. Pressure fluctuations were measured simultaneously. Vibration signals were processed using statistical analysis. For the sake of the evaluation, the vibration technique was used to calculate minimum fluidization velocity. It was shown that minimum fluidization velocity can be determined from the variation of standard deviation, skewness, and kurtosis of vibration signals against superficial gas velocity of the bed. Kurtosis was proved to be a new method of analyzing vibration signals. Results indicate that analyzing the vibration signals can be an effective nonintrusive technique to characterize the hydrodynamics of fluidized beds. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]

Intra-Patriline Variability in the Performance of the Vibration Signal and Waggle Dance in the Honey Bee, Apis mellifera

ETHOLOGY, Issue 7 2008
Nhi Duong
We examined intra-patriline behavioral plasticity in communication behavior by generating lifetime behavioral profiles for the performance of the vibration signal and waggle dance in workers which were the progeny of three unrelated queens, each inseminated with the semen of a single, different drone. We found pronounced variability within each patriline for the tendency to produce each signal, the ontogeny of signal performance, and the persistence with which individual workers performed the signals throughout their lifetimes. Within each patriline, the number of workers that performed each signal and the distribution of onset ages for each signal were significantly different. In each patriline, workers of all ages could perform vibration signals; vibration signal production began 3,5 d before waggle dancing; and some workers began performing waggle dances at ages typically associated with precocious foraging. Most workers vibrated and waggled only 1,2 d during their lifetimes, although each patriline contained some workers that performed the signal persistently for up to 8 or 9 d. We also found marked variability in signal performance among the three worker lineages examined. Because the vibration signal and waggle dance influence task performance, variability in signaling behavior within and between subfamilies may help to organize information flow and collective labor in honey bee colonies. Inter-patriline variability may influence the total number of workers from different partrilines that perform the signals, whereas intra-patriline variability may further fine-tune signal performance and the allocation of labor to a given set of circumstances. Although intra-patriline behavioral variability is assumed to be widespread in the social insects, our study is the first to document the extent of this variability for honey bee communication signals. [source]

Vibration signals from the FT joint can induce phase transitions in both directions in motoneuron pools of the stick insect walking system

DEVELOPMENTAL NEUROBIOLOGY, Issue 2 2003
Ulrich Bässler
Abstract The influence of vibratory signals from the femoral chordotonal organ fCO on the activities of muscles and motoneurons in the three main leg joints of the stick insect leg, i.e., the thoraco,coxal (TC) joint, the coxa,trochanteral (CT) joint, and the femur,tibia (FT) joint, was investigated when the animal was in the active behavioral state. Vibration stimuli induced a switch in motor activity (phase transition), for example, in the FT joint motor activity switched from flexor tibiae to extensor tibiae or vice versa. Similarly, fCO vibration induced phase transitions in both directions between the motoneuron pools of the TC joint and the CT joint. There was no correlation between the directions of phase transition in different joints. Vibration stimuli presented during simultaneous fCO elongation terminated the reflex reversal motor pattern in the FT joint prematurely by activating extensor and inactivating flexor tibiae motoneurons. In legs with freely moving tibia, fCO vibration promoted phase transitions in tibial movement. Furthermore, ground vibration promoted stance,swing transitions as long as the leg was not close to its anterior extreme position during stepping. Our results provide evidence that, in the active behavioral state of the stick insect, vibration signals can access the rhythm generating or bistable networks of the three main leg joints and can promote phase transitions in motor activity in both directions. The results substantiate earlier findings on the modular structure of the single-leg walking pattern generator and indicate a new mechanism of how sensory influence can contribute to the synchronization of phase transitions in adjacent leg joints independent of the walking direction. © 2003 Wiley Periodicals, Inc. J Neurobiol 56: 125,138, 2003 [source]

Intra-Patriline Variability in the Performance of the Vibration Signal and Waggle Dance in the Honey Bee, Apis mellifera

ETHOLOGY, Issue 7 2008
Nhi Duong
We examined intra-patriline behavioral plasticity in communication behavior by generating lifetime behavioral profiles for the performance of the vibration signal and waggle dance in workers which were the progeny of three unrelated queens, each inseminated with the semen of a single, different drone. We found pronounced variability within each patriline for the tendency to produce each signal, the ontogeny of signal performance, and the persistence with which individual workers performed the signals throughout their lifetimes. Within each patriline, the number of workers that performed each signal and the distribution of onset ages for each signal were significantly different. In each patriline, workers of all ages could perform vibration signals; vibration signal production began 3,5 d before waggle dancing; and some workers began performing waggle dances at ages typically associated with precocious foraging. Most workers vibrated and waggled only 1,2 d during their lifetimes, although each patriline contained some workers that performed the signal persistently for up to 8 or 9 d. We also found marked variability in signal performance among the three worker lineages examined. Because the vibration signal and waggle dance influence task performance, variability in signaling behavior within and between subfamilies may help to organize information flow and collective labor in honey bee colonies. Inter-patriline variability may influence the total number of workers from different partrilines that perform the signals, whereas intra-patriline variability may further fine-tune signal performance and the allocation of labor to a given set of circumstances. Although intra-patriline behavioral variability is assumed to be widespread in the social insects, our study is the first to document the extent of this variability for honey bee communication signals. [source]

Spectra of wavelet scale coefficients from process acoustic measurements as input for PLS modelling of pulp quality,

JOURNAL OF CHEMOMETRICS, Issue 8-10 2002
Anders Björk
Abstract Acoustic and vibration signals are captured by simple standard accelerometers. These can often be mounted directly on operative process equipment, creating a completely non-invasive measurement system. The signals from the accelerometer are then amplified, digitized by an analogue-to-digital converter and stored in some suitable format in a PC. The method most often used for signal processing of acoustic data has been to apply variants of fast Fourier transform (FFT) on sampled data to produce a frequency domain representation. An alternative way tried here is to use the fast wavelet transform (FWT) in combination with FFT. The FWT has the advantage that it produces time-resolved representations and, on each time scale, different features can be extracted. However, in this case, time resolution has no meaning, since the starting points for data acquisitions were not fixed. The wavelet step can be seen as a series of pre-filters and it is here followed by FFT on coefficients at each wavelet scale. The results are compared to those obtained after FFT on the complete time series. We have used spectra of wavelet scale coefficients in an attempt to model pulp quality with PLS. In this case the number of points in the resulting wavelet multiresolution spectrum (WT-MRS) can be limited to a low number, e.g. 255 compared to 1025 with direct FFT on the time series. In the PLS modelling step the advantage is that the first two components describe Y much better than when using the conventional approach, e.g. 72% explained Y variance compared to 40%. A second advantage is that the model requires fewer coefficients. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Nonintrusive characterization of fluidized bed hydrodynamics using vibration signature analysis

AICHE JOURNAL, Issue 3 2010
M. Abbasi
Abstract There are many techniques to characterize the hydrodynamics of fluidized beds, but new techniques are still needed for more reliable measurement. Bed vibrations were measured by an accelerometer in a gas,solid fluidized bed to characterize the hydrodynamics of the fluidized bed in a nonintrusive manner. Measurements were carried out at different superficial gas velocities and particle sizes. Pressure fluctuations were measured simultaneously. Vibration signals were processed using statistical analysis. For the sake of the evaluation, the vibration technique was used to calculate minimum fluidization velocity. It was shown that minimum fluidization velocity can be determined from the variation of standard deviation, skewness, and kurtosis of vibration signals against superficial gas velocity of the bed. Kurtosis was proved to be a new method of analyzing vibration signals. Results indicate that analyzing the vibration signals can be an effective nonintrusive technique to characterize the hydrodynamics of fluidized beds. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source]