A Spatial–Temporal Similar Graph Attention Network for Cyber Physical System Perception via Traffic Forecasting

Traffic flow forecasting is the basic challenge in intelligent transportation system (ITS). The key problem is to improve the accuracy of model and capture the dynamic temporal and nonlinear spatial dependence. Using real data is one of the ways to improve the spatial–temporal correlation modeling accuracy. However, real traffic flow data are not strictly periodic because of some random factors, which may lead to some deviations. This study focuses on capturing and modeling the temporal perturbation in real periodic data and we propose a spatial–temporal similar graph attention network (STSGAN) to address this problem. In STSGAN, the spatial–temporal graph convolution module is to capture local spatial–temporal relationship in traffic data, and the periodic similar attention module is to treat the nonlinear traffic flow information. Experiments on three datasets demonstrate that our model is best among all methods.

Auditory Feedback Is Used for Adaptation and Compensation in Speech Timing

Purpose Real-time altered feedback has demonstrated a key role for auditory feedback in both online feedback control and in updating feedforward control for future utterances. The aim of this study was to examine adaptation in response to temporal perturbation using real-time perturbation of ongoing speech. Method Twenty native English speakers with no reported history of speech or hearing disorders participated in this study. The study consisted of four word blocks, using the phrases “a capper,” “a gapper,” “a sapper,” and “a zapper” (due to issues with the implementation of perturbation, “gapper” was excluded from analysis). In each block, participants completed a baseline phase (30 trials of veridical feedback), a ramp phase (feedback perturbation increasing to maximum over 30 trials), a hold phase (60 trials with perturbation held at maximum), and a washout phase (30 trials, feedback abruptly returned to veridical feedback). Word-initial consonant targets (voice onset time for /k, g/ and fricative duration for /s, z/) were lengthened, and the following stressed vowel (/æ/) was shortened. Results Overall, speakers did not adapt the production of their consonants but did lengthen their vowel production in response to shortening. Vowel lengthening showed continued aftereffects during the early portion of the washout phase. Although speakers did not adapt absolute consonant durations, consonant duration was reduced as a proportion of the total syllable duration. This is consistent with previous research that suggests that speakers attend to proportional durations rather than absolute durations. Conclusion These results indicate that speakers actively monitor proportional durations and update the temporal dynamics of planning units extending beyond a single segment.

Auditory feedback is used for adaptive control of timing in speech

Real-time altered auditory feedback has demonstrated a key role for auditory feedback in both online feedback control and in updating feedforward control for future utterances. Much of this research has examined control in the spectral domain, and has found that speakers compensate for perturbations to vowel formants, intensity, and fricative center of gravity. The aim of the current study is to examine adaptation in response to temporal perturbation, using real-time perturbation of ongoing speech. Word-initial consonant targets (VOT for /k, g/ and fricative duration for /s, z/) were lengthened and the following stressed vowel (/æ/) was shortened. Overall, speakers did not adapt to lengthened consonants, but did lengthen vowels by nearly 100\% of the perturbation magnitude in response to shortening. Vowel lengthening showed continued aftereffects during a washout phase when perturbation was abruptly removed. Although speakers did not actively adapt consonant durations, the adaptation in vowel duration leads to the consonant taking up an overall smaller proportion of the syllable, aligning with previous research that suggests that speakers attend to proportional durations rather than absolute durations. These results indicate that speakers actively monitor duration and update upcoming plans accordingly.

Spatiotemporal perturbations in paced finger tapping suggest a common mechanism for the processing of time errors

Paced finger tapping is a sensorimotor synchronization task where a subject has to keep pace with a metronome while the time differences (asynchronies) between each stimulus and its response are recorded. A usual way to study the underlying error correction mechanism is to perform unexpected temporal perturbations to the stimuli sequence. An overlooked issue is that at the moment of a temporal perturbation two things change: the stimuli period (a parameter) and the asynchrony (a variable). In terms of experimental manipulation, it would be desirable to have separate, independent control of parameter and variable values. In this work we perform paced finger tapping experiments combining simple temporal perturbations (tempo step change) and spatial perturbations with temporal effect (raised or lowered point of contact). In this way we decouple the parameter-and-variable confounding, performing novel perturbations where either the parameter or the variable changes. Our results show nonlinear features like asymmetry and are compatible with a common error correction mechanism for all types of asynchronies. We suggest taking this confounding into account when analyzing perturbations of any kind in finger tapping tasks but also in other areas of sensorimotor synchronization, like music performance experiments and paced walking in gait coordination studies.

Temporal perturbation of Erk dynamics reveals network architecture of FGF2-MAPK signaling

Stimulation of PC-12 cells with epidermal (EGF) versus nerve (NGF) growth factors (GFs) biases the distribution between transient and sustained single-cell ERK activity states, and between proliferation and differentiation fates within a cell population. We report that fibroblast GF (FGF2) evokes a distinct behavior that consists of a gradually changing population distribution of transient/sustained ERK signaling states in response to increasing inputs in a dose response. Temporally-controlled GF perturbations of MAPK signaling dynamics applied using microfluidics reveals that this wider mix of ERK states emerges through the combination of an intracellular feedback, and competition of FGF2 binding to FGF receptors (FGFR) and heparan-sulfate proteoglycans (HSPGs) co-receptors. We show that the latter experimental modality is instructive for model selection using a Bayesian parameter inference. Our results provide novel insights into how different receptor tyrosine kinase (RTK) systems differentially wire the MAPK network to fine tune fate decisions at the cell population-level.Microfluidics, Erk Signaling Dynamics, Mechanistic Modelling, Parameter Estimation, Cell Fate Determination