Wander Effects Research Articles

Interpretation and prediction of the three-dimensional coherent structure and its dynamics of tornado-like vortex via delayed proper orthogonal decomposition

This study proposes a three-dimensional mode-based surrogate framework to predict the tornado-like vortex (TLV) derived from the fuzzy neural network and delayed proper orthogonal decomposition method. First, near-break-down TLV is simulated via large-eddy simulation, and its mean, fluctuating and statistical flow feature is analyzed. Then, three-dimensional spatiotemporal features of coherent structure are extracted and interpreted. Next, the capability of the proposed framework to predict the future state of an unsteady chaotic TLV flow field is systematically evaluated, including the spatiotemporal variation of velocity, pressure, and vorticities as well as flow statistics. Finally, parametric analysis is also conducted to investigate the influence of three key parameters [i.e., Fuzzy rules of the state network or output network (K1 or K2), time delayed embedding number (d)] contained in the framework and the step number of forward prediction (K) on the predicted accuracy. Results show that for near-break-down TLV, vortex wandering effect largely affects its dynamical feature, and its three-dimensional characteristics are distinct, exhibiting the essence of the swirling jet flow. 3D mode-based surrogate model can correctly predict the tornado-like vortex with a relative error of less than 2% for the radial, tangential, and vertical velocity component. It is found that fuzzy rules and time-delayed embedding number has great effect on prediction accuracy. Thus, to achieve optimal predicting effect, it is suggested that d is taken as 8, K1, and K2 are taken as 18, and when making multi-step predictions, the largest K should not exceed 7.

Costs over benefits: mind wandering in sporting performance.

Athletes' mind wandering during competition has positive and negative effects. The purpose of this study was to explore the reason for these bidirectional effects. We recruited 51 athletes from China to take part in semi-structured interviews in which we explored their experiences of mind wandering in competition. We used grounded theory combined with systems thinking to complete the data analysis and theoretical construction. Results showed that the influence of mind wandering on sporting performance was dynamically influenced by "mind wandering source," "competition anxiety," "content of mind wandering," "attentional resources" and "attentional control," resulting in our development of the theory of "mind wandering in sporting performance (MWSP)." The above factors determine how mind wandering occurs and how it affects the competition. Although the occurrence of mind wandering during competition has positive effects, its negative effects cannot be ignored, which may lead to athletes losing the race (costs over benefits). Potential strategies focusing on the mitigation of negative effects and promotion of positive effects of mind wandering are discussed.

Addressing wander effect in vehicle weight monitoring: An advanced hybrid weigh-in-motion system integrating computer vision and in-pavement sensors

Addressing wander effect in vehicle weight monitoring: An advanced hybrid weigh-in-motion system integrating computer vision and in-pavement sensors

Analysis of Pore Water Pressure Effect in Asphalt Patch Failure: An Integrated Modelling and Experiment Study

Moisture has been widely accepted as the main cause of asphalt patch failure, while the investigation of pore water pressure (PWP) in asphalt patch is limited. This research investigated the PWP generated in asphalt patch and quantified its impact on mechanical performance considering the inadequate compaction of asphalt patch. A hydro-mechanical model was first developed to analyze the PWP under field conditions, considering the effects of patch geometry, vehicle wandering, traffic loading, and temperature. The moisture-induced stress tester (MIST) was then used to condition patching materials under different PWP levels in a laboratory. After that, indirect tensile (IDT) and interface shear strengths of patching materials were evaluated to quantify the impact of PWP on material degradation. The numerical modeling results show that the maximum PWP can be within or at the interface of the asphalt patch, depending on the wheel path. The magnitude of PWP is related to the patch geometry, traffic load, and temperature. The maximum PWP, whether inside or at the interface of the asphalt patch, can be from 100 kPa to over 300 kPa under common field conditions. The laboratory experimental results suggest that the first 500 cycles of MIST conditioning led to over 30% decrease in both IDT and interface shear strengths of asphalt patch, and the strength ratio was much lower than the recommended level. These findings indicate that asphalt patches with poor compaction quality are very susceptible to moisture-induced damage, and the mechanical performance of patching material should be evaluated after conditioning with PWP effect.

Modelling Investigation of Atmospheric Turbulence-Induced Beam Deviation for LEO/GEO FSO Communication Link

The uplink analytical simulation scenario of atmospheric turbulence-induced beam deviation can give the insight needed to understand and create the mitigation techniques that could support novel applications in the fields of free-space optical communications (FSOC) and the generation of laser guide stars. One of the significant challenges that causes wandering and fading of the beam from the receiver aperture is beam deviation. In this study, two uplink numerical modelling scenarios for low-earth orbit (LEO) and geostationary (GEO) satellites will be investigated and discussed. The work seeks to visualize the effective parameters and analytically simulate atmospheric optical propagation, especially for the wandering effect, which can give concrete milestones for developing a new scientific investigation era and deeper insight into the system’s theoretical demonstration of free-space optical communications.

Experimental investigation on the dynamics of buoyancy-induced vortices

Experimental investigation on the dynamics of buoyancy-induced vortices

Mind wandering, motivation, and task performance over time: Evidence that motivation insulates people from the negative effects of mind wandering.

Mind wandering, motivation, and task performance over time: Evidence that motivation insulates people from the negative effects of mind wandering.

BER for a space uplink laser communication system under an actual optical distortion with a cake-cutting method.

A numerical calculating model is proposed for characterizing the BER performance of the detector working among the 2-D asymmetric distorted spot on the effects of atmospheric turbulence under weak turbulent conditions. Based on the isotropy of the beam wander effect, we introduce a beam wander vector to describe the behavior of the detector drifting among the receiving plane. Furthermore, using the cake-cutting method, the overall PDF of the light intensity is approximated by the average PDF of light intensity intercepted by the detector drifting in all different directions. The results demonstrate that the model obtains the overall PDF of the light intensity received by the detector and analyzes the BER performance of the communication system efficiently. Being an extension of the traditional 1-D calculation, our proposed model has important implications for designing the space uplink optical communication system.

Experimental study of the transport characteristics of fractional-order vortex beams in a turbulent atmosphere simulator

Fractional vortex beams have attracted increasing attention due to their complex yet intriguing physical properties, such as radial notch intensity distribution and higher degrees of modulation in orbital angular momentum. In this study, we experimentally investigated and compared the beam spread and beam wander characteristics of fractional-order vortex beams with those of integer-order vortex beams after passing through a turbulent atmosphere simulator with varying turbulence intensities. Our results revealed that the beam spread of both fractional-order and integer-order vortex beams increased in a stepwise manner with the topological charge number, indicating that a larger topological charge number resulted in more severe beam spread. Interestingly, we observed that the beam radius of fractional-order vortex beams between two adjacent integer orders initially grew slowly and then rapidly before finally stabilizing into a curvilinear growth trend. This is in contrast to the linear growth trend exhibited by the beam radius of integer-order vortex beams. Furthermore, we found that the growth of the beam radius of half-integer-order vortex beams followed the linear growth trend of the beam radius of integer-order vortex beams. When the integer part of the topological charge was fixed, we observed that stronger turbulence resulted in more severe beam wander for both integer-order and fractional-order vortex beams, with the variance of the center-of-mass drift following the same growth curve. However, when the turbulence intensity is constant, both integer-order and fractional-order vortex beams exhibit a weaker beam wander effect with increasing topological charge. Our findings may provide valuable insights for applications such as optical communication and optical measurement using fractional-order vortex beams.

Word Familiarity Modulates the Interference Effects of Mind Wandering on Semantic and Reafferent Information Processing.

It has been found that mind wandering interferes with the sensory and cognitive processing of widespread stimuli. However, it remains unclear what factors can modulate the magnitude of the interference effects of mind wandering. Here, we investigate whether and how word familiarity modulates the interference effects of mind wandering on semantic and reafferent information processing. High- and low-frequency words were used as stimuli to induce high- and low-familiarity contexts in a sustained attention to response task, in which participants were required to respond to Chinese nonanimal words (nontarget) and withhold responses to Chinese animal words (target) as well as to intermittently report whether their state was "on task" or "off task." Behavioral results revealed lower reaction stability for both high- and low-frequency nontarget words preceding "off-task" reports than those preceding "on-task" reports. However, ERP results revealed that low-frequency rather than high-frequency words elicited more negative N400, attenuated late positive complex, and attenuated reafferent potential for "off-task" reports than for "on-task" reports. The results suggest that mind wandering makes semantic extraction and integration more difficult for unfamiliar but not familiar two-character Chinese words and attenuates the reafferent feedback of the motor response. These findings are consistent with the decoupling hypothesis of mind wandering and provide the first neural evidence for how familiarity with external stimuli modulates the interference effects of mind wandering.

Wander Effect on Pavement Performance for Application in Connected and Autonomous Vehicles

Connected and Autonomous Vehicles (CAV) will change how road engineers design road pavements because they can position themselves within a traffic lane, keeping their position in the lane more precisely than human-driven vehicles. These vehicles will have lower lateral wandering, which can induce more damage to pavements, such as cracking and permanent deformation, than the conventional vehicles, with consequences for the infrastructures due to the increased cracking and reduced safety due to the rutting. Thus, it is essential to assess the wander effect on pavement performance to define policies for its implementation on CAV. This paper studies the impact of the lateral wander of the traffic on pavement performance, considering its fatigue and permanent deformation resistance. This impact can be used to define limits for the wander to minimize distresses on the pavement. The results of this study allow us to conclude that for a pavement with a 10 cm asphalt layer, the wander effect is more significant for fatigue life. A pavement life increase of 20% was observed for a wander of 0.2 m, while for 0.6 m, the fatigue life can increase up to 48%. For the permanent deformation, a pavement life increase of 2% for a wander of 0.2 m was observed, but for 0.6 m, the pavement life can be increased up to 34%.

Commonalities between mind wandering and task-set switching: An event-related potential study

Previous research has established that mind wandering does not necessarily disrupt one's task-switching performance. Here we investigated the effects of mind wandering on electrophysiological signatures, measured using event-related potentials (ERPs), during a switching task. In the current study, a final sample of 22 young adults performed a task-switching paradigm while electroencephalography was continuously recorded; mind wandering was assessed via thought probes at the end of each block. Consistent with previous research, we found no significant disruptive effects of mind wandering on task-switching performance. The ERP results showed that at the posterior electrode sites (P3, Pz, and P4), P3 amplitude was higher for mind-wandering switch trials than on-task switch trials, thus opposing the typical pattern of P3 attenuation during periods of mind wandering relative to on-task episodes. Considering that increased P3 amplitude during higher-order switch trials (e.g., response rule switching) may reflect the implementation of new higher-order task sets/rules, the current findings seem to indicate similar executive control processes underlie mind wandering and task-set switching, providing further evidence in favor of a role for switching in mind wandering.

Mind Wandering in Information Technology Use: Scale Development and Cross- Validation

Because our minds frequently drift away, an investigation into mind wandering while using information technology (IT) is critical. Despite growing interest in mind-wandering episodes in various domains, the discipline of Information Systems (IS) still lacks a validated measurement instrument that can account for the technology-related facets of the phenomenon. Our work addresses this gap and presents the results of a comprehensively developed scale that is specifically designed for IS scenarios. Using existing literature and the results of a pilot study (N = 35), a field study (N = 364), and a cross-validation sample (N = 336), we developed a new instrument that allows mind wandering while using technology to be measured either as a state (MWS) or as a trait with two subtypes (MWT-D: deliberate, and MWT-S: spontaneous). Whereas MWS captures a momentary mental state or a sequence of mental states that arise relatively freely while using technology in a given moment, MWT-D and MWT-S capture either intentional or unintentional, internally focused thoughts in technology-related settings in everyday life. Our scale is well suited to support future research to investigate the effects of mind wandering in technology-related settings and to study its implications for IS-relevant dependent variables, such as task performance and creativity.

Evaluation of Airport Pavement Base Layer Stiffness Characteristics via Embedded Field Sensors

Real-time stiffness monitoring of unbound aggregate layers using embedded field sensors is crucial for advanced airport pavement design and management. This paper describes research findings on monitoring base layer stiffness characteristics for airport pavements using an embedded bender element (BE) field sensor, inductive coil sensors, and pressure cells. A full-scale pavement test section was constructed at the Federal Aviation Administration (FAA)’s National Airport Pavement Test Facility (NAPTF). A BE field sensor, inductive coil sensor pairs, and pressure cells were installed in the unbound aggregate base to evaluate the layer stiffness, applied load stress, and deformation characteristics. A triple dual tandem gear loading module applied 58,000 lb per wheel to the tested section with a wander pattern consisting of 66 passes arranged in nine lateral wander positions. Dynamic responses of coil sensors and pressure cells were collected during the traffic test, whereas BE signals were collected after completing each wander pattern. Laboratory repeated load triaxial tests with BE instrumentation were also conducted to establish a correlation for converting BE field sensor readings to layer modulus properties. The in situ modulus characteristics of the aggregate base layer were evaluated during full-scale testing using two methods: shear wave velocities from a BE field sensor, and strain and stress measurements from coil sensors and pressure cells. The moduli estimated using both approaches fell into typical ranges of crushed aggregate bases and were highly comparable. The moduli from the dynamic sensor measurements clearly showed the effect of vehicle wander on aggregate base layer measured responses.

Research on uplink performance of MIMO terrestrial-satellite laser communication based on OSM-MBM joint modulation

This paper proposes a multiple-input multiple-output (MIMO) terrestrial-satellite laser communication uplink system based on optical spatial modulation with medium-based modulation (OSM-MBM) joint modulation. The Málaga(M) distribution is used to describe the combined effects of near-ground turbulent light intensity scintillation, beam wander and angle of arrival fluctuation. The closed expression of the bit error rate (BER) of the OSM-MBM joint modulation MIMO terrestrial-satellite laser communication uplink is derived. The simulation analyzes the influence of transmitting radius, receiving aperture, beam divergence, zenith angle and signal-to-noise ratio on the system error performance, and compares it with traditional modulation, media-based modulation and optical space modulation. Finally, the experiment is verified by Monte Carlo. This research provides a theoretical reference for the engineering realization of the modulation technology for the MIMO terrestrial-satellite laser communication uplink system.

Measuring the effects of mind wandering in people with insomnia: A driving simulator study

PurposeStudies have shown that individuals with insomnia experience more frequent and longer episodes of mind wandering (MW) while driving. However, the effect of the interaction between insomnia and MW on driving behavior is not fully understood. This study aimed to gain deeper insights into the relationships among insomnia, MW, and driving behavior.Patients and methodsForty-two participants (21 diagnosed with insomnia and 21 controls) were recruited, and subjective sleep quality and cognitive function were assessed. A driving simulator experiment with a within-subject design was performed, involving two distraction tasks (no-distraction task versus MW task) and two driving scenarios (lane-keeping versus lane-changing).ResultsIn the lane-keeping scenario, there was no significant between-group difference (people with insomnia and controls) in longitudinal driving performance for the no-distraction task, although the interaction between MW and insomnia significantly increased drivers’ longitudinal control variation. Correlation analysis confirmed that longitudinal driving performance was positively correlated with sleep quality and the cognitive level. Unlike longitudinal driving performance, lateral driving performance was significantly weaker in people with insomnia than in controls under both distraction tasks. In the lane-changing scenario, although there was no between-group difference in driving performance, the MW task led to significant changes in driving performance within each group compared with the no-distraction task, and these findings were associated with cognitive function, but not with sleep quality.ConclusionThese findings show that insomnia and MW combined can lead to reduced driving performance. Further research is needed to elucidate the factors that influence this phenomenon.

Analysis of wander and spreading of an optical beam by using the oceanic turbulence optical power spectrum

Variance of beam displacement and short-term and long-term spreading of a Gaussian beam propagating in the presence of underwater turbulence are examined by using the oceanic turbulence optical power spectrum (OTOPS). Analytical expressions for both beam wander displacement variance and beam spreading are presented. Results show that the underwater turbulent channel causes deflection from the on-axis mean irradiance and brings significant wander and spreading effects to the propagating Gaussian beam wave. The variations of beam wander and short- and long-term spreading are obtained depending on the underwater medium parameters such as the average temperature, average salinity concentration, temperature-salinity gradient ratio, and temperature and energy dissipation rates. In particular, the real values of the average temperature and salinity concentration of turbulent water are used to obtain the results. In addition, the effects of propagation distance, Gaussian beam source size, and wavelength are shown. The results demonstrate that the underwater turbulent channel brings displacements in the centroid and spreading of the optical beam.

Jurassic true polar wander recorded by the Lhasa terrane on its northward journey from Gondwana to Eurasia

Paleomagnetic data constrain paleogeographic motion of rocks relative to the Earth's spin axis, which is a sum of plate motion relative to the mantle and true polar wander. Discerning between these effects is challenging for studies aiming to reconstruct paleo-plate motions from deformed orogenic terranes. Here, we study the paleolatitudinal drift history of the Lhasa terrane of southern Tibet that migrated from the northern Gondwana to the southern Eurasian margin between late Triassic and early Cretaceous time. Previous work identified a 180 Ma near-equatorial Lhasa latitude and assumed near-constant paleolatitudinal drift. Large-scale true polar wander at this time, however, which has been argued for in previous work, requires highly variable Lhasa plate motion rates relative to Gondwana. Here, we test whether the alternative interpretation of constant plate motion rates provides a better prediction of paleomagnetic data. To this end, we present a new paleomagnetic pole from ∼155 Ma volcanics (here dated by U/Pb zircon) of the Lhasa terrane. Our pole comprises site mean directions from 46 lavas, passes a fold test, and is supported by an extensive rock magnetic and microscopic analysis that reveals no evidence of remagnetization. Our results give an average direction of D ± Δ D x = 337.1 ° ± 2.6 ° , I ± Δ I x = − 13.8 ° ± 4.9 ° , and a corresponding paleopole position at λ p = 45.3 ° N, φ p = 295.3 ° E with K=69.8 and A 95 = 2.5 ° , predicting a similar near-equatorial, paleolatitude as at 180 Ma. This paleolatitudinal standstill is consistent with predicted paleolatitudes from global APWPs that account for Jurassic TPW and assume a constant Lhasa-Gondwana (India) oceanic spreading rate of ∼8 cm/a during the 215-130 Ma opening of the Neotethys and closure of the Mesotethys oceans. Contemporaneous arc magmatism on the Lhasa terrane was previously interpreted to indicate that the Lhasa terrane was located above a subduction zone during its northward journey to Tibet: our results show that if our reconstruction is accurate, then trench migration rates also must have been ∼8 cm/a. Our results are consistent with the range of rates of global long-lived trench migration that have been reconstructed in other studies, but they are much higher than measured in most modern systems. Our results more completely document the Lhasa terrane's separation from Gondwana and provide a straightforward methodology of using paleomagnetic data to test plate kinematic scenarios, overcoming the problem of the unknown effect of true polar wander on paleomagnetic data from deformed terranes. To better constrain the paleolatitude and paleogeography of the Lhasa terrane within Eastern Tethys realm in the Jurassic time, we used paleomagnetic and zircon U-Pb dating technique to try to give a quantitative constraint. To this end, we obtained a high-quality paleopole with well-dated age of 155 Ma from the Upper Jurassic-Lower Cretaceous Zenong Group volcanic rocks of the Lhasa terrane (southern Tibet). Based on this newly obtained paleopole, it predicts a similar paleolatitude as a recently published 61-lava based pole of 180 Ma of the Sangri volcanics, showing that the Lhasa terrane stayed at a southern hemisphere near-equatorial position over at least 25 Myr starting from 180 Ma up to 155 Ma, indicating a distinct stand-still feature for the Lhasa terrane during this time interval. On the other side, this paleolatitudinal stand-still is consistent with predicted paleolatitudes by global APWPs assuming a constant Lhasa-Gondwana (India) spreading rate during the 215-130 Ma opening of the Neotethys and closure of the Mesotethys oceans. We show that this Jurassic paleolatitudinal stand-still of the Lhasa terrane is readily explained by the interplay between true polar wander shifting Lhasa to the south and plate motion shifting Lhasa to the north. Finally, our results unlock the mobile Lhasa terrane and its overlying Jurassic magmatic record, as future study site to a proposed major, short-lived true polar wander event in the latest Jurassic and earliest Cretaceous. • A high-quality ∼155 Ma paleopole was obtained from the Zenong Group volcanics within central Lhasa terrane. • Zenong Group volcanics recorded paleolatitudinal standstill of Lhasa, which was ascribed to Jurassic True Polar Wander. • This recorded standstill of the Lhasa terrane is a sum of true polar wander and its northward plate tectonic motion.

Benefits of Mind Wandering for Learning in School Through Its Positive Effects on Creativity

There is broad agreement among researchers to view mind wandering as an obstacle to learning because it draws attention away from learning tasks. Accordingly, empirical findings revealed negative correlations between the frequency of mind wandering during learning and various kinds of learning outcomes (e.g., text retention). However, a few studies have indicated positive effects of mind wandering on creativity in real-world learning environments. The present article reviews these studies and highlights potential benefits of mind wandering for learning mediated through creative processes. Furthermore, we propose various ways to promote useful mind wandering and, at the same time, minimize its negative impact on learning.

Temporal changes in electroencephalographic power spectrum on passive listening to three selected melodic scales of Indian music on healthy young individuals - a randomized controlled trial

Music is said to affect the brain in different ways. To the best of our knowledge, research works on the effect of passive listening to different melodic scales of Indian music on Electroencephalogram (EEG) power spectrum is rare to find. In this randomized control trial, 137 healthy subjects were randomly divided into 4 groups (A to D, n~32 in each group), of which A (raga Ahir Bhairav), B (raga Kaunsi Kanada), C (raga Bhimpalas) received music intervention while group D was the control arm. Nineteen channel scalp EEG was recorded for 30 minutes [10 min for each condition, before (BI), during (DI) and after intervention (AI)] and conducted power spectral analysis of waveforms in standard frequency bands. Two-way ANOVA was performed across conditions and groups, to determine the scalp regions showing significant changes, for each frequency band separately. Across conditions, significant change in BI alpha and AI theta, beta1, beta2 bands, while between groups, group B had significant change in alpha and group C in beta1 power, mostly involving frontal regions was seen. Mid Frontal PSA exhibited an increased theta power in group C and D (AI), while alpha and beta1 power increased in group B and C (in group C, beta2 increased significantly). Temporal trend analysis (2-minute segments), showed that there was a significant fall in frontal alpha DI in group B; while in A, C and D groups, the drop seen BI reduced DI and AI. Similarly, the beta1 drop reduced DI and AI in group C and D, while it increased in group B (DI) and group A (AI). Music caused relaxation effect with scales B and C causing maximal effect. In line with existing literature, it may be concluded that listening to these melodic scales was associated with mind wandering effect and probable visual imagery/recall.