Amplitude Of Component Research Articles

Energy-based high frequency oscillation control of linear drives

Linear electromagnetic actuators realizing periodic oscillations have gained significant importance in the compressor and pump technology. This is due to the need of compact drive units to increase the power density of modern pumps and compressors. This work presents an energy-based control approach for harmonic oscillations of linear electromagnetic drives and analyzes the functionality and performance of the oscillation control for periodic actuator movements up to 250 Hz. To obtain a more robust control behavior, the control structure needs to be decoupled, with an amplitude and phase component using a periodical harmonic carrier function. This approach avoids a standstill of the actuator by constantly triggering an oscillation at the fundamental frequency of the mechanical system. The presented control approach is especially beneficial for oscillatory systems which need to adapt their oscillation frequency to mechanical loads.

On the possibility of experiments on the excitation of artificial ultra-low and extra-low frequency emissions in the ionosphere by the FENICS installation on the Kola peninsula

A numerical model has been developed to calculate the electromagnetic response in the ionosphere from grounded ultra-low-frequency transmitters of finite length L. Such megatransmitters are the ZEVS installation with a carrier frequency of 82 Hz and the FENICS installation, which can generate artificial emissions at frequencies from fractions of a Hz to a few hundreds of Hz. The amplitude of radiation excited in the upper ionosphere by a grounded horizontal current suspended above a high-resistance earth’s surface has been calculated. The altitude profile of the plasma parameters was reconstructed using the IRI ionospheric model. For the ZEVS transmitter (L = 60 km) powered by a current of 200 A, the simulated amplitudes of the electromagnetic response in the nighttime ionosphere can reach ~60 μV/m, which was confirmed by observations on the DEMETER satellite. According to calculations, the FENICS facility (L = 100 km), powered by a current of 100 A, can generate radiation in the nighttime upper ionosphere with a frequency of 10—100 Hz and an amplitude of up to ~60—70 μV/m. The FENICS facility can be used to excite artificial Pc1 pulsations that could be detected on low-Earth-orbit satellites (e.g., CSES). To create pulsations in the nighttime ionosphere at a frequency of 0.5 Hz with the amplitudes of the magnetic component 1 pT and the electric component 10 μV/m, the current in the FENICS antenna is to be 100 A.

Analytical solution for the seismic response of a nearly saturated sloping seabed: Weak interlayer

Sloping seabeds often exist in offshore areas with complex structures. It is difficult to accurately analyze the seismic response characteristics of sloping seabeds based on the assumptions used for horizontal seabeds. The degree of saturation in nearly saturated soil notably affects the seismic response of seabeds. Therefore, we developed an analytical solution for the seismic response of a sloping, nearly saturated multilayer seabed. Using this solution, we analyzed the effects of the slope angle and soil saturation degree on the seismic response of the seabed. The results show that the seafloor inclination may has a minor impact on the seismic motion at a specific point, but it has a very significant effect on the overall site. A weak interlayer refers to a layer of material that has lower strength and/or permeability compared to the surrounding soil or rock. This layer can reduce the natural frequency of the seabed and increase the amplitude of long-period seismic components. In addition, the presence of a weak interlayer can lead to increased pore water pressure, decreased effective stress, and increased susceptibility to shear failure. These factors combine to reduce the stability of submarine slopes, highlighting the importance of understanding and managing the effects of weak interlayers in geotechnical engineering and coastal defense projects.

Fixation-related potentials during mobile map assisted navigation in the real world: The effect of landmark visualization style.

An often-proposed enhancement for mobile maps to aid assisted navigation is the presentation of landmark information, yet understanding of the manner in which they should be displayed is limited. In this study, we investigated whether the visualization of landmarks as 3D map symbols with either an abstract or realistic style influenced the subsequent processing of those landmarks during route navigation. We utilized a real-world mobile electroencephalography approach to this question by combining several tools developed to overcome the challenges typically encountered in real-world neuroscience research. We coregistered eye-movement and EEG recordings from 45 participants as they navigated through a real-world environment using a mobile map. Analyses of fixation event-related potentials revealed that the amplitude of the parietal P200 component was enhanced when participants fixated landmarks in the real world that were visualized on the mobile map in a realistic style, and that frontal P200 latencies were prolonged for landmarks depicted in either a realistic or abstract style compared with features of the environment that were not presented on the map, but only for the male participants. In contrast, we did not observe any significant effects of landmark visualization style on visual P1-N1 peaks or the parietal late positive component. Overall, the findings indicate that the cognitive matching process between landmarks seen in the environment and those previously seen on a map is facilitated by more realistic map display, while low-level perceptual processing of landmarks and recall of associated information are unaffected by map visualization style.

Fault diagnosis study of hydraulic pump based on improved symplectic geometry reconstruction data enhancement method

Aiming at the problem of poor consistency between the enhanced samples and the original samples in the current data enhancement methods. In this paper, we propose a data enhancement method with improved symplectic geometry reconstruction. The method expands a sufficient number of augmented samples while ensuring high similarity to real fault samples. First, the components to be augmented and their weights are selected from the decomposed symplectic geometric modal components using a random sampling method. Second, a data-weighted scaling criterion is formulated to augment the modal component amplitudes. Then, the summation and reconstruction of all amplitude enhancement components are performed on the basis of ensuring that the statistical characteristics of the enhanced samples remain consistent with the original samples. Finally, the proposed method is combined with the deep residual network, and the experimental dataset of hydraulic pump failure simulation is utilized to verify the effectiveness of the proposed method in obtaining the enhanced fault sample information. The diagnostic results show that the fault diagnosis model established by the method has higher accuracy and convergence ability in hydraulic pump data imbalance fault diagnosis compared with other comparative models.

An analytical model for the analysis of vibration and energy flow in a clamped stiffened plate using integral transform technique

Based on Kirchhoff thin plate and Mindlin thick plate theories, the vibration and energy flow characteristics of clamped stiffened plate are studied by using the analytical model constructed by finite integral transform method. The results show that the energy flow characteristics of the stiffened plate at the beam/plate coupling interface depend on the position of the rib in the vibration modes of the plate. The effects of shear deformation and rotatory inertia on the energy flow across the beam/plate coupling interface of the stiffened plate are further investigated. It is found that the inclusion of rotatory inertia of the beam and plate in the model only affects the energy flow component controlled by the moment coupling but not that controlled by the shear force coupling. Whilst the inclusion of the shear deformation of the beam and plate mainly causes a decreased amplitude of the energy flow for the mode group where the beam is located away from both the nodal and antinodal lines of modes, in addition to the shear deformation of the plate which also leads to an increased amplitude of the energy flow component controlled by the shear force coupling for the mode group where the beam locates at the antinodal line of modes. The understanding of energy flow characteristics of the stiffened plate at the beam/plate interface is essential to effectively control the noise and vibration problems of structures such as transformer tanks and machine covers.

Optimization of pulse shape discrimination based on frequency domain for SiPM-based NaIL scintillator detector

Frequency gradient analysis (FGA) neutron-gamma pulse shape discrimination (PSD) based on Fourier transform has proved to be an effective method for discrimination between two types of pulses by simply constructing a discrimination parameter by subtracting the amplitude of the 1st frequency component from the 0th frequency component. However, the discrimination parameter constructed by the above method could not meet the requirements at some lower sample rates, and the dark noise caused using optoelectronic devices such as miniaturized SiPMs array further erodes the difference between the two frequency components. This paper proposes a new discrimination parameter construction method based on FGA for neutron-gamma discrimination, which is referred as mFGA (modified FGA). This discrimination parameter uses the 0th frequency component and other frequency components to enhance the discrimination performance. A neutron detector module consisting of a 25.4 mm× 25.4 mm× 50.8 mm NaI:Tl,6Li (NaIL) scintillator and an array of 8 × 8 SiPMs was established to verify the method of mFGA. The module measured a 252Cf neutron source under three shielding conditions: no shield, 5 cm high-density polyethylene (HDPE), and 10 cm lead brick. The proposed mFGA method was used to calculate the figure of merit (FoM) under each shielding condition and compared to the traditional frequency gradient method (FGA) and the traditional charge comparison method (CCM). The results show that the discrimination performance with the mFGA method is significantly improved. Taking the HDPE shielding group as an example, the performances of the three methods are FoM-FGA =1.14, FoM-mFGA =2.75, FoM-CCM =0.92. At the same time, with the increase of energy, due to the neutron gamma pulse becoming similar, and the discrimination performance of FGA and CCM decrease significantly. The discrimination performance of the mFGA method is relatively stable in all energy regions. Therefore, the proposed method is superior to the traditional FGA of the 0th frequency minus the 1st frequency and has a good application prospect for neutron-gamma discrimination with detectors of poor signal quality.

Frequency effects can modulate the neural correlates of prosodic processing in Mandarin.

In tonal languages, tone perception involves the processing of both acoustic and phonological information conveyed by tonal signals. In Mandarin, in addition to four canonical full tones, there exists a group of weak syllables known as neutral tones. This study aims to investigate the impact of lexical frequency effects and prosodic information associated with neutral tones on the auditory representation of Mandarin compounds. We initially selected disyllabic compounds as targets, manipulating their lexical frequencies and prosodic structures. Subsequently, these target compounds were embedded into selected sentences and auditorily presented to native speakers. During the experiments, participants engaged in lexical decision tasks while their event-related potentials were recorded. The results showed that the auditory lexical representation of disyllabic compounds was modulated by lexical frequency effects. Rare compounds and compounds with rare first constituents elicited larger N400 effects compared to frequent compounds. Furthermore, neutral tones were found to play a role in the processing, resulting in larger N400 effects. Our findings showed significantly increased amplitudes of the N400 component, suggesting that the processing of rare compounds and compounds with neutral tones may require more cognitive resources. Additionally, we observed an interaction effect between lexical frequency and neutral tones, indicating that they could serve as determining cues in the auditory processing of disyllabic compounds.

Broad Learning System Using Rectified Adaptive Moment Estimation for Harmonic Detection and Analysis

The extensive application of nonlinear components and power electronic devices in power systems has led to increasingly deteriorating harmonic pollution. The rapid and high-precision harmonic detection and analysis technology will set the prerequisite for mitigating the harmonic crisis. This paper presents a robust, stable and real-time approach based on broad learning system (BLS) for detecting and analyzing the amplitudes of fundamental and harmonic components, which only requires half or even quarter cycle input. Additionally, a fast-converging adaptive parameter learning strategy using rectified adaptive moment estimation (RAdam) for BLS is proposed. To obtain the actual distorted signals, the signal acquisition system is built on the basis of the designed multi-pulse rectifier power supply (6/18 pulse). With the fundamental frequency deviation, interharmonics and noise, etc., the simulated signals synthesized by MATLAB tool and the actual signals acquired from the built system are attained to verify the performance of methods. The proposed approach differentiates from other existing methods not only due to its superior precision and robustness in the presence of multitudinous interference factors but also its real-time performance because of low average computing time.

Group membership modulates empathic neural responses to pain in deaf individuals.

Empathy deficiencies are prevalent among deaf individuals. It has yet to be determined whether they exhibit an ingroup bias in empathic responses. This study employed explicit and implicit empathy tasks (i.e. attention-to-pain-cue [A-P] task and attention-to-nonpain-cue [A-N] task) to explore the temporal dynamics of neural activities when deaf individuals were processing painful/nonpainful stimuli from both ingroup models (deaf people) and outgroup models (hearing people), which aims to not only assist deaf individuals in gaining a deeper understanding of their intergroup empathy traits but also to aid in the advancement of inclusive education. In the A-P task, we found that (i) ingroup priming accelerated the response speed to painful/nonpainful pictures; (ii) the N2 amplitude of painful pictures was significantly more negative than that of nonpainful pictures in outgroup priming trials, whereas the N2 amplitude difference between painful and nonpainful pictures was not significant in ingroup priming trials. For N1 amplitude of the A-N task, we have similar findings. However, this pattern was reversed for P3/late positive component amplitude of the A-P task. These results suggest that the deaf individuals had difficulty in judging whether hearing individuals were in pain. However, their group identification and affective responses could shape the relatively early stage of pain empathy.

Dependence of the Values of Inter-Component Phase Relations of the Harmonic Components of Vibration on the Displacement of Misaligned Shafts

The analytical dependence of the phases and values of intercomponent phase relations of the harmonic components of vibration displacement of misaligned shafts on their displacement has been presented in the article. Harmonic vibrations of the shafts were modeled using a Lagrangian connecting vibration displacement and forces acting in the system. For ease of derivation, the Lagrangian is rewritten in complex form. The resulting algebraic equations connect the complex amplitudes of vibration components with the amplitudes of periodic forces at the same frequencies and the parameters of the mechanical system (stiffness, damping). The amplitudes of periodic forces are related to the magnitude of the shafts angular and parallel misalignment according to the accepted model. Calculation of intercomponent phase relations values is used to get rid of the random initial phase shift caused by the choice of the timing reference. The magnitude of the effect produced by the misalignment of the shafts on the amplitudes and values of the intercomponent phase relations of the signal components is estimated. The obtained resultcan be used to construct devices for estimation shaft displacements and devices for assessing the condition of equipment based on the analysis of vibration signals.ls.

Influence of perceived social support on detection of social norm violation: evidence from N1 and N400.

The perceived social support individuals receive from their others plays a crucial role in shaping conformity with social norms. However, the specific mechanism underlying perceived social support and the detection of social norms remains unclear. In this study, college students with high and low levels of perceived social support were asked to judge the appropriateness of stranger's behaviors (e.g., singing) in different situations (e.g., library). The participants' electroencephalography activities were analyzed aiming to uncover the neural mechanism underlying how perceived social support influences the detection of others' normative behavior. The ERP results indicate that, for individuals with a lower level of perceived social support, larger amplitudes of the N1 component (related to primary processing) and the N400 component (related to cognitive conflict) were observed when detecting others' social norm violation compared to the conformity condition. However, for individuals with a higher level of perceived social support, no significant differences were found in detecting others' conformity or violation of social norms. The results indicate that, when the perceived social support level of the individual is low, detecting others' social norm violation elicits deeper primary processing and stronger cognitive conflict compared to conformity condition.

A sleepless night disrupts the resolution of emotional conflicts: Behavioural and neural evidence.

The present study aims to investigate the influence of 24-hr sleep deprivation on implicit emotion regulation using the emotional conflict task. Twenty-five healthy young adults completed a repeated-measures study protocol involving a night of at-home normal sleep control and a night of in-laboratory sleep deprivation. Prior to the experimental session, all participants wore an actigraph watch and completed the sleep diary. Following each condition, participants performed an emotional conflict task with electroencephalographic recordings. Emotional faces (fearful or happy) overlaid with words ("fear" or "happy") were used as stimuli creating congruent or incongruent trials, and participants were instructed to indicate whether the facial expression was happy or fearful. We measured the accuracy and reaction time on the emotional conflict task, as well as the mean amplitude of the P300 component of the event-related potential at CPz. At the behavioural level, sleep-deprived participants showed reduced alertness with overall longer reaction times and higher error rates. In addition, participants in the sleep deprivation condition made more errors when the current trial followed congruent trials compared with when it followed incongruent trials. At the neural level, P300 amplitude evoked under the sleep-deprived condition was significantly more positive compared with the normal sleep condition, and this effect interacted with previous-trial and current-trial congruency conditions, suggesting that participants used more attentional resources to resolve emotional conflicts when sleep deprived. Our study provided pioneering data demonstrating that sleep deprivation may impair the regulation of emotional processing in the absence of explicit instruction among emerging adults.

Retinal Function in Long-Term Type 1 Diabetes without Retinopathy: Insights from Pattern Electroretinogram and Pattern Visual Evoked Potentials Assessments.

To evaluate changes in pattern electroretinogram (pERG) and pattern visual evoked potentials (pVEP) in patients with long-lasting type 1 diabetes without diabetic retinopathy (DR). Prospective study involving 92 eyes divided into two groups. The diabetic group included 46 eyes of 23 patients with type 1 diabetes (T1DM); the control group included 23 age-matched healthy subjects. pERG and pVEP were assessed using the RETI-port/scan21 recording software (version 1021.3.0.0). Mean age was 48 ± 9.77 years for the diabetic group and 51.7 ± 4.75 years for the control group. The mean duration of diabetes was 28.88 ± 8.04 years. The mean HbA1c value was 7.29 ± 0.89%. There were no differences in the age or sex distribution. Regarding the pERG, T1DM patients exhibited a significant decrease in the amplitude of the P50 and N95 waves compared to the control group (p = 0.018 and p = 0.035, respectively), with no differences in the peak time of each component. pVEP showed no significant changes in either peak time or amplitude of the different components. Long-term T1DM patients without DR showed changes in the amplitude of pERG waves with preserved peak times. We did not observe modifications in pVEP. pERG may serve as a subclinical marker of ganglion cell damage in long-term T1DM patients.

Detection of Water Surface Acoustic Waves Using Sinusoidal Phase Modulation Interferometer and Prenormalized PGC-Arctan Algorithm

A sinusoidal phase modulation laser interferometer is proposed to detect water surface acoustic waves excited by underwater acoustic radiation, and an improved PGC-Arctan demodulation algorithm that combines prenormalization and Lissajous ellipse fitting is proposed to demodulate detection signals. In this paper, the effects of phase modulation depth, carrier phase delay, and interference signal visibility on the Lissajous figure formed by quadrature interference components are analyzed. The demodulation algorithm first uses the amplitudes of multiple Fourier spectral components of an interference signal to calculate the phase modulation depth C, and calculation of the carrier phase delay Vc is achieved through the introduction of a quadrature carrier signal. Then, certain coefficients regarding C and Vc are constructed for prenormalization of the two quadrature interference signal components to eliminate the local nonuniform widening phenomenon of Lissajous ellipse. Next, the outer and the inner contours are extracted from a uniformly widened Lissajous ellipse resulting from light intensity disturbance, and the axial ratio of the ellipse is obtained, which is used to correct the ratio of the quadrature interference signal to eliminate the effect of filter gain coefficients. At last, through the combination of an Arctan algorithm and a phase-unwrapping algorithm, high-precision demodulation of the interference signal is realized. A sinusoidal phase modulation interferometer was set up to detect water surface acoustic waves, and a series of detection experiments were carried out. The experiment results show that the detection method and demodulation algorithm described in this paper can accurately realize the measurement of weak water surface acoustic waves. The proposed algorithm shows less distortion in demodulation results, and its signal-to-noise distortion ratio is less than 20 dB at 500 Hz, which is significantly better than traditional algorithms. The experimental results demonstrate the effectiveness and accuracy of water surface acoustic wave detection using sinusoidal phase modulation interferometer.

Fast and Stable Responses during Decision Making Require Strong Inhibitory Processes in Soccer Players.

Quick decision making is a vital factor for a successful pass in soccer games. Many previous studies of decision making in soccer focused on motor execution, but inhibitory processing has remained unclear. This study aimed to clarify the differences in motor execution and inhibitory among Japanese collegiate soccer players with different skill levels. We evaluated the behavioral data and event-related potentials in the high-skilled, low-skilled, and novice groups during the Go/No-go and pass choice reaction tasks. The reaction time (RT) was significantly shorter in the high group than in the novice group, and RT variability was small in the high group. The amplitude of the N2 component was significantly larger in the high group than in the low and novice groups, and the latency of the P3 component was significantly shorter in the high and low groups than in the novice group during the pass choice reaction task. The subtracted No-go N2 amplitude was also significantly larger in the high and low groups than in the novice group, and correlations existed between the RT, RT variability, and the subtracted No-go N2 amplitude during these tasks. These data indicate that soccer players' behavioral responses and inhibition processing decision-making activities are associated with skill levels.

The effects of word and beat priming on Mandarin lexical stress recognition: an event-related potential study

Abstract Music and language are unique communication tools in human society, where stress plays a crucial role. Many studies have examined the recognition of lexical stress in Indo-European languages using beat/rhythm priming, but few studies have examined the cross-domain relationship between musical and linguistic stress in tonal languages. The current study investigates how musical stress and lexical stress influence lexical stress recognition in Mandarin. In the auditory priming experiment, disyllabic Mandarin words with initial or final stress were primed by disyllabic words or beats with either congruent or incongruent stress patterns. Results showed that the incongruent condition elicited larger P2 and the late positive component (LPC) amplitudes than the congruent condition. Moreover, the Strong-Weak primes elicited larger N400 amplitudes than the Weak-Strong primes, and the Weak-Strong primes yielded larger LPC amplitudes than the Strong-Weak primes. The findings reveal the neural correlates of the cross-domain influence between music and language during lexical stress recognition in Mandarin.

Acoustic change complex findings in mild and moderate sensorineural hearing loss

BackgroundAuditory electrophysiological tests of the cortex, which are processed in or close to the auditory cortex, are brain reactions to sound. A variation in a continuous stimulus causes the acoustic change complex potential (ACC), which is a wave following the P1-N1-P2 response.ObjectiveTo measure the amplitude and latency of different components of ACC in normal subjects and across individuals with mild and moderate degrees of sensorineural hearing loss (SNHL).Patients and methodsThe study includes 100 individuals with the age ranged from 10 to 50 years with different degrees of SNHL. The ACC was evoked by a change of second formant in the middle of ongoing steady-state synthetic, 3 formant vowels (ooee). The total duration was 500 ms. Changing occurred at 250 ms.ResultsThe SNHL subgroups showed statistically significantly longer P1 and N1 latencies. N1 and P2 amplitudes of ACC onset response were larger with a statistical significance as compared to controls. Post hoc analysis revealed no statistically significant difference between mild and moderate SNHL on ACC parameters. Age showed a significant negative correlation with ACC N1 and P2 latency, ACC P1 and N1 amplitude, and onset P2 latency. Onset response P1 latency was significantly higher in children than adults. Median ACC P1 amplitude significantly increased in children than adults.ConclusionACC is a reliable tool for testing the auditory cortex function of detecting difference in sounds presented that can be recorded readily in patients with mild and moderate SNHL.

Effects of location of nano-enhanced PCM-packed bed on the process of heat transfer and phase transition in a nonuniform magnetic field

The phase change and thermal process intensification under nonuniform magnetic field (MGF) effects during hybrid nanofluid (NF) convection are investigated in this study using various arrangements of phase change material (PCM)-packed bed (PB) in a vented cavity. The PCM-PB is is considered as a triangular shape. The numerical research is done using the finite element method for different Reynolds numbers (Re between 200 and 600), inlet port sizes (between 0.5 and 2.5), Hartmann numbers (Ha between 0 and 60), nonuniform MGF component amplitudes (between 0 and 1), and different locations of the triangle PCM-PB zone. The process of phase change is accelerated by increasing the Re and port size, and the entire transition time (tf ) is reduced by 63% and 76%, respectively, when mix/max Re and min/max port sizes are considered. By using NF, the phase change is improved even further, and tf is further reduced by 17.6%–31.5%. When MGF strength and amplitude of the nonuniform component are increased, tf is reduced by about 13% and 6%. At the highest Ha, the average heat transfer (HT) drops by about 59%. The flow patterns, phase transition, and thermal performance are all significantly impacted by the placement of the PCM-PB zone. In terms of phase change process, configuration C2 by using NF at Ha = 60 is the best case while case at Ha = 0 by using only water is the worst case. The tf value is reduced by about 82.6% at the best case. When phase change and HT processes are considered, the optimal design of triangular PCM-PB zones alters.

Probing the Bottleneck of Awareness Formed by Foveal Crowding: A Neurophysiological Study.

Crowding occurs when an easily identified isolated stimulus is surrounded by stimuli with similar properties, making it very difficult to identify. Crowding is suggested as a mechanism that creates a bottleneck in object recognition and awareness. Recently, we showed that brief presentation times at the fovea resulted in a significant crowding effect on target identification, impaired the target's color awareness, and resulted in a slower reaction time. However, when tagging the target with a red letter, the crowding effect is abolished. Crowding is widely considered a grouping; hence, it is pre-attentive. An event-related potential (ERP) study that investigated the spatial-temporal properties of crowding suggested the involvement of higher-level visual processing. Here, we investigated whether ERP's components may be affected by crowding and tagging, and whether the temporal advantage of ERP can be utilized to gain further information about the crowding mechanism. The participants reported target identification using our standard foveal crowing paradigm. It is assumed that crowding occurs due to a suppressive effect; thus, it can be probed by changes in perceptual (N1, ~160 ms) and attentive (P3 ~300-400 ms) components. We found a suppression effect (less negative ERP magnitude) in N1 under foveal crowding, which was recovered under tagging conditions. ERP's amplitude components (N1 and P3) and the behavioral proportion correct are highly correlated. These findings suggest that crowding is an early grouping mechanism that may be combined with later processing involving the segmentation mechanism.