220 research outputs found

    Modeling and Analysis of Permanent Magnet Spherical Motors by A Multi-task Gaussian Process Method and Finite Element Method for Output Torque

    Get PDF
    Permanent magnet spherical motors (PMSMs) operate on the principle of the dc excitation of stator coils and three freedom of motion in the rotor. Each coil generates the torque in a specific direction, collectively they move the rotor to a direction of motion. Modeling and analysis of the output torque are of critical importance for precise position control applications. The control of these motors requires precise output torques by all coils at a specific rotor position, which is difficult to achieve in the three-dimension space. This article is the first to apply the Gaussian process to establish the relationship of the rotor position and the output torque for PMSMs. Traditional methods are difficult to resolve such a complex three-dimensional problem with a reasonable computational accuracy and time. This article utilizes a data-driven method using only input and output data validated by experiments. The multitask Gaussian process is developed to calculate the total torque produced by multiple coils at the full operational range. The training data and test data are obtained by the finite-element method. The effectiveness of the proposed method is validated and compared with existing data-driven approaches. The results exhibit superior performance of accuracy

    Investigating word length effects in Chinese reading

    Get PDF
    A word’s length in English is fundamental in determining whether readers fixate it, and how long they spend processing it during reading. Chinese is unspaced and most words are two characters long: Is word length an important cue to eye guidance in Chinese reading? Eye movements were recorded as participants read sentences containing a one-, two-, or three-character word matched for frequency. Results showed that longer words took longer to process (primarily driven by refixations). Furthermore, skips were fewer, incoming saccades longer and landing positions further to the right of long than short words. Additional analyses of a three-character region (matched stroke number) showed an incremental processing cost when character(s) belonged to different, rather than the same, word. These results demonstrate that word length affects both lexical identification and saccade target selection in Chinese reading

    The influence of foveal lexical processing load on parafoveal preview and saccadic targeting during Chinese reading

    Get PDF
    Whether increased foveal load causes a reduction of parafoveal processing remains equivocal. The present study examined foveal load effects on parafoveal processing in natural Chinese reading. Parafoveal preview of a single-character parafoveal target word was manipulated by using the boundary paradigm (Rayner, 1975; pseudocharacter or identity previews) under high foveal load (low-frequency pretarget word) compared with low foveal load (high-frequency pretarget word) conditions. Despite an effective manipulation of foveal processing load, we obtained no evidence of any modulatory influence on parafoveal processing in first-pass reading times. However, our results clearly showed that saccadic targeting, in relation to forward saccade length from the pretarget word and in relation to target word skipping, was influenced by foveal load and this influence occurred independent of parafoveal preview. Given the optimal experimental conditions, these results provide very strong evidence that preview benefit is not modulated by foveal lexical load during Chinese reading. (PsycINFO Database Record (c) 2019 APA, all rights reserved

    The influence of emotional face distractors on attentional orienting in Chinese children with autism spectrum disorder

    Get PDF
    The current study examined how emotional faces impact on attentional control at both involuntary and voluntary levels in children with and without autism spectrum disorder (ASD). A non-face single target was either presented in isolation or synchronously with emotional face distractors namely angry, happy and neutral faces. ASD and typically developing children made more erroneous saccades towards emotional distractors relative to neutral distractors in parafoveal and peripheral conditions. Remote distractor effects were observed on saccade latency in both groups regardless of distractor type, whereby time taken to initiate an eye movement to the target was longest in central distractor conditions, followed by parafoveal and peripheral distractor conditions. The remote distractor effect was greater for angry faces compared to happy faces in the ASD group. Proportions of failed disengagement trials from central distractors, for the first saccade, were higher in the angry distractor condition compared with the other two distractor conditions in ASD, and this effect was absent for the typical group. Eye movement results suggest difficulties in disengaging from fixated angry faces in ASD. Atypical disengagement from angry faces at the voluntary level could have consequences for the development of higher-level socio-communicative skills in ASD

    The morphosyntactic structure of compound words influences parafoveal processing in Chinese reading

    Get PDF
    In an eye movement experiment employing the boundary paradigm (Rayner, 1975) we compared parafoveal preview benefit during the reading of Chinese sentences. The target word was a 2-character compound that had either a noun-noun or an adjective-noun structure each sharing an identical noun as the second character. The boundary was located between the two characters of the compound word. Prior to the eyes crossing the boundary the preview of the second character was presented either normally or was replaced by a pseudo-character. Previously, Juhasz, Inhoff and Rayner (2005) observed that inserting a space into a normally unspaced compound in English significantly disrupted processing and that this disruption was larger for adjective-noun compounds than for noun-noun compounds. This finding supports the hypothesis that, at least in English, for adjective-noun compounds, the noun is more important for lexical identification than the adjective, while for noun-noun compounds, both constituents are similar in importance for lexical identification. Our results indicate a similar division of the importance of compounds in reading in Chinese as the pseudo-character preview was more disruptive for the adjective-noun compounds than for the noun-noun compounds. These findings also indicate that parafoveal processing can be influenced by the morphosyntactic structure of the currently fixated character

    Keap1 modulates the redox cycle and hepatocyte cell cycle in regenerating liver

    Get PDF
    Keap1 negatively controls the activity of transcription factor Nrf2. This Keap1/Nrf2 pathway plays a critical role in combating oxidative stress. We aimed at determining whether and how Keap1 modulates the cell cycle of replicating hepatocytes during liver regeneration. Two-thirds partial hepatectomy (PH) was performed on wild-type mice and Keap1+/- (Keap1 knockdown) mice. We found that, following PH, Keap1 knockdown resulted in a delay in S-phase entry, disruption of S-phase progression, and loss of mitotic rhythm of replicating hepatocytes. These events are associated with dysregulation of c-Met, EGFR, Akt1, p70S6K, Cyclin A2, and Cyclin B1 in regenerating livers. Astonishingly, normal regenerating livers exhibited the redox fluctuation coupled with hepatocyte cell cycle progression, while keeping Nrf2 quiescent. Keap1 knockdown caused severe disruption in both the redox cycle and the cell cycle of replicating hepatocytes. Thus, we demonstrate that Keap1 is a potent regulator of hepatic redox cycle and hepatocyte cell cycle during liver regeneration

    Task Demands Modulate the Effects of Speech on Text Processing

    Get PDF
    Task-irrelevant background sound can disrupt performance of visually-based cognitive tasks. The cross-modal breakdown of attentional selectivity in the context of reading was addressed using analyses of eye-movements. Moreover, the study addressed whether task-sensitivity to distraction via background speech on reading was modulated by the cognitive demands of the focal task. Two randomly-assigned groups of native-Chinese participants read the same set of Chinese experimental sentences while being exposed to meaningful speech, meaningless (foreign) speech, or silence. For one group, participants were instructed to judge whether the sentences made sense (i.e., semantic acceptability task); for another, participants were instructed to detect whether the sentences contained a non-character (i.e., non-character detection task). Results showed no significant effect across sound conditions for the non-character detection task. For the semantic acceptability task, however, there was a substantial disruptive effect of the meaningfulness of the speech. Compared with reading with meaningless speech or reading in silence, the meaningful speech increased numbers of fixations, regressions, regression path and total reading times. These results suggest that the disruption of reading by background speech is jointly dependent on the nature of the speech and the task-process deployed, thereby favouring an Interference-by-Process account over Interference-by-Content and Attentional Diversion accounts of distraction to reading by background sound

    Nuclear Factor Erythroid 2-Related Factor 2 Deficiency Results in Amplification of the Liver Fat-Lowering Effect of Estrogen

    Get PDF
    Transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) regulates multiple biologic processes, including hepatic lipid metabolism. Estrogen exerts actions affecting energy homeostasis, including a liver fat-lowering effect. Increasing evidence indicates the crosstalk between these two molecules. The aim of this study was to evaluate whether Nrf2 modulates estrogen signaling in hepatic lipid metabolism. Nonalcoholic fatty liver disease (NAFLD) was induced in wild-type and Nrf2-null mice fed a high-fat diet and the liver fat-lowering effect of exogenous estrogen was subsequently assessed. We found that exogenous estrogen eliminated 49% and 90% of hepatic triglycerides in wild-type and Nrf2-null mice with NAFLD, respectively. This observation demonstrates that Nrf2 signaling is antagonistic to estrogen signaling in hepatic fat metabolism; thus, Nrf2 absence results in striking amplification of the liver fat-lowering effect of estrogen. In addition, we found the association of trefoil factor 3 and fatty acid binding protein 5 with the liver fat-lowering effect of estrogen. In summary, we identified Nrf2 as a novel and potent inhibitor of estrogen signaling in hepatic lipid metabolism. Our finding may provide a potential strategy to treat NAFLD by dually targeting Nrf2 and estrogen signaling
    • …
    corecore