Search Results (1,635)

Electromechanical actuators (EMAs) are increasingly used in aerospace servo actuation because of their compact structure, high power density, and convenient integration with electric flight-control systems. However, load-side aerodynamic torque, friction, parameter perturbations, and unmodeled transmission effects enter the EMA dynamics through a channel different from the motor-current input, which leads to a mismatched disturbance rejection problem. This paper develops a feedback-linearization-assisted observer-based interconnection and damping assignment passivity-based control (IDA-PBC) method for EMA trajectory tracking. A fourth-order input–output feedback-linearized normal-coordinate model is first derived, through which the original load-side mismatched disturbance is transformed into a matched term acting on the highest-order channel. An extended state observer is then constructed to estimate the transformed disturbance. Based on the observer output, a desired Hamiltonian function is generated from a Lyapunov equation, and the interconnection and damping matrices are explicitly assigned so that the closed-loop tracking-error dynamics admit a dissipative port-Hamiltonian representation. A composite Lyapunov analysis proves closed-loop exponential stability under the assumption of slowly varying disturbance. The resulting framework combines the disturbance-channel-reshaping capability of feedback linearization with the energy-shaping interpretation of IDA-PBC, providing a systematic controller design for high-precision EMA servo systems subject to load-side disturbances. Full article

Polygonatum cyrtonema Hua polysaccharides (PCPs) are bioactive components with antioxidant and immunomodulatory properties. However, whether the polysaccharides derived from elder Polygonatum cyrtonema exhibit superior health benefits remains unclear. This study systematically compared the in vitro fermentation characteristics, gut microbiota-modulating effects, and short-chain fatty acid (SCFA) production of PCPs extracted from three-year-old (TPP), five-year-old (FPP), and eight-year-old (EPP) plants using a human fecal fermentation model. The fermentation dynamics were evaluated by monitoring pH, OD₆₀₀, and the consumption of total and reducing sugars, while the structural degradation and compositional differences in PCPs were tracked via molecular weight distribution and monosaccharide composition analysis. The results showed that all three PCPs were degraded and utilized by gut microbiota, accompanied by decreased pH, increased OD₆₀₀, and enhanced antioxidant activities. High-throughput 16S rDNA sequencing revealed that, at the phylum level, all PCPs increased the Firmicutes/Bacteroidetes ratio. At the genus level, they reduced the abundance of harmful bacteria such as Sutterella and increased beneficial bacteria including Bifidobacterium and Megasphaera. Furthermore, gas chromatography (GC) analysis demonstrated that, compared with FPP, TPP and EPP significantly promoted the production of SCFAs. In summary, this study indicates that the in vitro fermentation characteristics and prebiotic properties of PCPs vary with growth years, and a comprehensive evaluation suggests that three-year-old Polygonatum cyrtonema Hua represents a promising raw material for the development of functional foods. Full article

Variation in gaze behavior due to age is currently a considerable challenge in building reliable eye-tracking systems for Autism Spectrum Disorder (ASD) diagnosis. However, existing strategies often focus on static gaze representation or dataset-based information, which can lead to limited generalization of findings depending on developmental groups and heterogeneous recording conditions. In this paper, we present a temporal transformer-based system for ASD classification using eye-tracking sequences. This allows you to model gaze behavior as a structured temporal process in the context of contextual attention, as well as employing entropy-based modeling for various distributions of variability over time and temporal consistency constraints to capture sequential gaze dynamics related to ASD behavioral patterns. The framework was evaluated using public eye-tracking corpus containing temporally ordered gaze recordings from ASD and TD participants across age groups. Five sequential experiments on baseline classification, class-balancing analysis, cross-age evaluation, ablation analysis, and cross-dataset transfer learning were performed to conduct experiment-based evaluations. Model performed 0.91 in in-domain Area Under the Receiver Operating Characteristic Curve (AUC) and 0.81 in F1-score on the primary eye-tracking dataset. In the cross-dataset assessment stage, the framework presented a relatively stable performance, with an AUC of 0.85 and an average F1-score of 0.74, irrespective of differences in participant distributions and recording conditions. Ablation analysis also revealed that entropy regularization and temporal consistency mechanisms played a significant role in model stability and classification performance. The ablation analysis provides additional insight into the contribution of the proposed framework components beyond the overall classification performance. Removing the entropy-based regularization reduced the model’s ability to represent variability in gaze allocation, whereas removing the temporal-consistency regularization resulted in less stable sequence representations during learning. These observations indicate that the proposed components complement the transformer-based sequence encoder by improving representation stability and preserving diagnostically relevant temporal information. Rather than acting as independent classifiers, the regularization mechanisms serve as supporting constraints that enhance the quality and robustness of the learned temporal representations. The results indicate that temporally structured gaze modeling is more robust, interpretable, and general in comparison to static gaze representations. In summary, the presented framework can represent a scalable and developmentally appropriate approach to gaze-based ASD classification and support the implementation of trusted neurodevelopmental screening systems. Full article

Twin Rotor Multi-Input Multi-Output (TRMS) platforms combine strong aerodynamic cross-coupling, gravitational loading on the vertical axis, friction-dominated horizontal dynamics, and systematic mismatch between idealised models and laboratory hardware. The platform provides only two optical encoders, so the angular rates and the rotor states are unavailable for feedback. This paper presents an observer-based output-feedback architecture that addresses both difficulties. A high-gain observer built on the fully coupled six-state model, including the gyroscopic terms that the control design cannot retain, reconstructs the four unmeasured states from the two encoder angles. The reconstructed states drive a Hybrid Backstepping–Super-Twisting (B-STA) controller in which a second-order continuous sliding mode is embedded at the final recursive step through a composite surface. Because backstepping requires strict-feedback structure, which the centralised coupled model does not possess, the controller is synthesised on a decentralised design model and the residual coupling is rejected as a matched perturbation of the sliding variable. Closed-loop behaviour is analysed as a three-stage cascade covering observer error, sliding variable, and tracking error, yielding practical stability under bounded residuals with an explicit input-to-state gain. The residual bounds are evaluated numerically from the actuator saturation limit and the identified coefficients rather than assumed, and the resulting figures are shown to predict the marked difference in sliding-variable behaviour observed between the two axes. A second architecture applies a windowed Grey Wolf Optimiser (B-GWO) to the backstepping gains, in which each candidate is applied to the plant for a fixed test window, scored on its own accumulated integral of time-weighted absolute error, and followed by a settle window at the incumbent best. We prove that this windowing is a requirement rather than a convenience: a fitness evaluated at a single sample is common to all candidates, cancels from the population ranking, and reduces the search to the minimiser of its own regularisation term. Both schemes are implemented on a physical TRMS through a Simulink Desktop Real-Time interface at a control period of $10\mathrm{ms}$. On a $100\mathrm{s}$ experimental run, B-STA attains a pitch tracking error of $0.0318\mathrm{rad}$ RMS, $7.94\%$ of the reference amplitude, and the lowest control energy on both axes among the strategies compared, reducing pitch control energy by $72.9\%$ relative to a first-order Backstepping–Sliding Mode baseline recorded on the same interface. Numerical disturbance rejection tests on the fully coupled model confirm the mechanism: under a matched actuator step the super-twisting integrator state migrates to a new steady level that cancels the disturbance, driving the residual pitch error to $2\times {10}^{-4}\mathrm{rad}$, whereas the same recursive law without the second-order injection retains a permanent offset of $0.28\mathrm{rad}$. Full article

Social hierarchy represents a ubiquitous principle of social organization, often intuitively conceptualized as a pyramidal structure. The present study investigated whether subjective power can reshape this mental representation, thereby attenuating perceived psychological distance between social classes. Using eye-tracking technology and time-series representational similarity analysis, we measured participants’ gaze patterns toward stimuli denoting high- and low-status individuals under different power states. Results revealed a robust upward gaze bias toward high-status targets in the control condition, consistent with a pyramid-like representation in which upper classes occupy the apex and lower classes the base. This bias was amplified in the powerless condition but significantly attenuated in the powerful condition, suggesting that subjective power transforms the internalized hierarchy into a more egalitarian configuration, wherein social classes are perceived as more equivalent. Furthermore, power states systematically modulated horizontal gaze position and pupil diameter. These findings provide novel insights into how subjective power dynamically reshapes the representation of social hierarchy and point to new theoretical avenues for reducing perceived inequality at the psychological level. Full article

The reversible effects of general anesthesia can be used to examine how brain activity changes during transitions into and out of altered conscious states. Such changes are commonly tracked using behavioral responses, electroencephalographic recordings, and measures of functional connectivity. These measures, however, reflect processes occurring at lower levels of organization, including the activity of pyramidal neurons, dendritic integration, interneuron function, thalamocortical signaling, and glial regulation of the extracellular environment. Anesthesia does not affect all neural processes equally. Propofol and volatile agents interfere with synaptic transmission and apical dendritic integration, as well as cortical feedback and thalamocortical signaling. The resulting activity is not necessarily absent or uniformly weaker. It is often more stereotyped, temporally restricted, and poorly coordinated between regions. Ketamine produces a different organization. Substantial neural activity and complex cortical responses may persist after behavioral responsiveness has been lost, although deeper anesthesia also produces slower and less complex activity. Responsiveness, environmental connectedness, memory, reportability, and conscious content may therefore become partly uncoupled. Ketamine produces a dissociative state that cannot be interpreted simply as another form of the predominantly restrictive state produced by propofol or volatile anesthetics. This narrative review synthesizes evidence identified through a structured PubMed search to examine how anesthesia reshapes conscious processing and why unresponsiveness or absent recall may not indicate absent experience. Full article

Disamenity and amenity facilities pull property values in opposite directions, yet prior studies have treated disamenities as a homogeneous category and have been constrained by data scattered across agencies and by mismatched spatial scales. This study integrates multi-source spatial data, comprising 3426 sub-districts (eup-myeon-dong) nationwide, a 500 m population grid of 376,668 cells, and the actual point locations of individual facilities, into a single spatial framework and applies a multi-method design that combines a spatial Durbin model (SDM), explainable machine learning (XGBoost–SHAP), an environmental-justice analysis, and a micro-siting analysis. Four findings emerge. First, not all disamenities are associated with lower prices: only pollution-emitting facilities with a clear emission signature, namely, sewage treatment plants and incinerators, capitalize robustly as cross-sectional associations, into both housing prices and officially assessed land values, with the effect extending into neighboring sub-districts rather than staying purely local. The other disamenities show no robust total effect on either price; their estimates are small or unstable across specifications. Second, capitalization of pollution-emitting facilities is pronounced in the urban sample and disappears in the rural one, and the coefficient structure differs overall between urban and rural areas (global Chow test, p < 10⁻²¹). Third, micro-siting analysis shows that where a facility is placed (siting) and what it leaves behind in prices (capitalization) are distinct layers, and that capitalization tracks the population a facility keeps nearby rather than its nuisance type: pollution-emitting facilities retain enough nearby housing for their burden to register, whereas funerary facilities sited far from people do not. Fourth, the environmental inequity of pollution exposure runs along income rather than age and concentrates in cities rather than in rural areas: the exposure rate among residents of low-income urban sub-districts (49%) is 2.5 times that of the urban population as a whole (19%), while the greater Seoul metropolitan area remains comparatively insulated. These layered findings were possible only once the dispersed spatial data had been integrated and standardized, and the study demonstrates that fusing and efficiently managing spatial data is a precondition for evidence-based land-use and environmental policy. Full article

Background and Objectives: Free flap reconstruction is the gold standard for complex head and neck defects following oncological ablation. While surgical techniques have improved flap success rates, donor site sensory morbidity remains relatively understudied. The radial forearm free flap (RFFF) and fibula free flap (FFF) are the two most commonly used free flaps for head and neck reconstruction and sensory abnormalities at their donor sites represent a significant but underrecognized source of postoperative morbidity. Materials and Methods: The aim of this study is to systematically review and synthesize the existing evidence on the prevalence, characteristics and assessment methods of sensory abnormalities and pain at the donor sites of RFFF and FFF harvests. A systematic review was conducted according to PRISMA 2020 guidance. PubMed/MEDLINE, Scopus, Web of Science, the Cochrane Library, and Google Scholar were searched from inception to 1 October 2025, with additional gray-literature and reference-list screening. Primary studies reporting sensory abnormalities, donor-site pain, neuropathic pain, or cold intolerance after RFFF and/or FFF harvest were included; prior reviews were used for citation tracking and contextual comparison only. Risk of bias was assessed with study-design-specific Joanna Briggs Institute (JBI) checklists, and the level of evidence was classified using the Oxford Centre for Evidence-Based Medicine (OCEBM) framework. Descriptive prevalence summaries and exploratory random-effects pooled estimates were calculated when numerators and denominators could be extracted. Results: From 1247 initially identified records, 73 studies met the inclusion criteria (36 RFFF-specific, 35 FFF-specific, and 2 addressing both flap types). Most studies were observational, and sensory outcomes were frequently secondary endpoints. For RFFF, reported sensory abnormalities ranged from 0% to 100% across extractable studies (median 31.3%; IQR 13.1–55.0%), reflecting differences in definitions, follow-up, and testing; the exploratory pooled prevalence was 34.4% (95% CI 23.6–47.1%; I2 = 88.4%). General donor-site pain ranged from 0% to 36.8% (median 12.0%; pooled 16.0%, 95% CI 9.9–24.8%), whereas Douleur Neuropathique en 4 Questions (DN4)-defined neuropathic pain was 18% in the largest dedicated RFFF study and 18% in a smaller pain-focused study. Cold intolerance ranged from 0% to 40.0% (median 16.2%). For FFF, sensory abnormalities ranged from 0% to 76.3% (median 21.4%; IQR 8.2–46.8%; pooled 24.0%, 95% CI 16.5–33.6%; I2 = 88.6%). General pain ranged from 0% to 72.7% (median 17.5%; pooled 18.8%, 95% CI 13.9–24.9%), and DN4-defined neuropathic pain was 21% in the only dedicated FFF study. Objective testing (quantitative sensory testing [QST], Semmes-Weinstein monofilaments, two-point discrimination, or standardized neurological examination) was used inconsistently, and no included study systematically used nerve conduction studies or electromyography (EMG). Conclusions: Sensory abnormalities and pain after RFFF and FFF harvest appear common, but available estimates remain uncertain because of heterogeneous definitions, follow-up intervals, assessment instruments, and predominantly Level 2b-4 evidence. The literature shows a persistent gap between patient-reported symptoms and objective sensory testing. Future prospective studies would benefit from standardized neuropathic pain screening, structured neurological examination, and QST; however, current data do not support strong causal inferences or a validated treatment algorithm. Full article

Tomographic synthetic aperture radar (TomoSAR) effectively characterizes forest vertical structure, while baseline configuration strongly affects forest height retrieval accuracy. However, systematic baseline analysis is limited by the lack of real multi-baseline datasets with controllable configurations. In this study, the landscape-scale canopy backscatter model (LandSAR) is used to simulate airborne P-band SAR data under different baseline configurations. LandSAR performance is first evaluated against real P-band InSAR data and lidar canopy height. Forest height is then retrieved under a known-ground assumption, and the effects of inter-track baseline spacing, track number, and total aperture length on forest height retrieval are analyzed at different flight altitudes. The results show that retrieval accuracy is governed by the coupled effects of baseline spacing and track number. For small baseline spacings, accuracy improves with increasing track number, but the improvement remains limited. Larger spacings improve retrieval performance, whereas overly large spacing or aperture may reduce the height ambiguity margin and reconstruction stability. The optimal accuracies are 4.72 m, 4.58 m, 4.52 m and 4.48 m at flight altitudes of 3000 m, 3500 m, 4000 m and 4500 m, respectively. This study provides a physically interpretable reference for airborne P-band TomoSAR configuration design. Full article

Manual disassembly is a key process in remanufacturing and circular-economy systems, yet it is often characterized by uncertainty, varying product conditions and non-standardized action sequences. Eye tracking provides a process-oriented methodology for examining how such tasks are visually guided, with implications for human behavior analysis, operator support, and automation design. The present study investigated the potential of specific eye and gaze metrics to reflect differences in task condition and process dynamics during human disassembly. These were analyzed using a dimension-based mixed-effect modeling approach, accounting for task condition, handcraft skill levels, and task duration across repeated observations within participants, addressing four dimensions: visual attention allocation, cognitive workload, scanpath structure, and gaze organization. The results showed that increased task uncertainty was most associated with shorter fixation durations, higher fixation rates, larger pupil diameters, and higher revisit rates, indicating intensified visual sampling, increased cognitive workload, and repeated checking behavior. No robust differences were observed between skill levels. A longer task duration, as an indirect proxy of less routine-like execution, was primarily reflected in fixation dynamics and scanpath structure, rather than in entropy or workload measures. The findings demonstrate the sensitivity of eye and gaze metrics to task uncertainty and process dynamics in disassembly. Full article

Signal interpretation in embedded ultrasonic monitoring depends strongly on the internal transmission path of the sensing element, yet this design factor has received limited systematic attention. This work compares two triangular quartz sensors that differ only in the configuration of their epoxy region: an epoxy-notched triangular quartz (ENTQ) device and an epoxy-solid triangular quartz (ESTQ) device. Their responses were examined during 24 h mortar hydration, controlled heating and cooling, and loading-induced debonding. The notch in ENTQ exposes part of the direct-wave route to changing external media, whereas the continuous epoxy region in ESTQ provides a more uniform internal route. Across the investigated conditions, ESTQ retained a more consistent direct-wave waveform and dominant-frequency pattern, while its later-arriving components remained responsive to changes in the surrounding mortar. Energy and time-frequency features also tracked the evolution of mortars prepared at two mix proportions. The comparison indicates that separation of a stable internal reference path from an environmentally sensitive reflected-wave path can improve the interpretability of embedded ultrasonic measurements. The results support structural-path design as a useful strategy for sensor development. Full article

This paper studies the automatic berthing control of an unmanned surface vessel under cyber attacks. An adaptive neural-network-based fault-tolerant control method is developed. Unknown vessel dynamics, external disturbances, measurement noise, and cyber attacks are considered at the same time. First, the signal scaling, bias, and power-type distortion caused by cyber attacks are described by a unified nonlinear measurement model. The model has a known structure and unknown parameters. It converts different attack effects into structured uncertainties. Based on the corrupted position and attitude measurements, the tracking errors are defined. The vessel heading is reconstructed by integrating the unaffected yaw-rate signal. A Nussbaum-type function is introduced to handle the unknown gain in the measurement channel. A first-order filter is used to generate a smooth approximation of the virtual control signal. A neural network is then employed to approximate the unknown vessel dynamics. Adaptive laws are designed to estimate the composite uncertainties and external disturbances. Lyapunov analysis shows that all closed-loop signals remain bounded. The berthing tracking errors ultimately converge to a compact set around the origin. Finally, a berthing simulation with time-varying cyber attacks, measurement noise, and marine disturbances is conducted to evaluate the proposed method. Full article

Background: Relapse following successful stuttering treatment is a common clinical challenge, yet strategies to support long-term stability after therapy termination remain insufficiently examined. We examined whether sustained clinical follow-up, without additional therapy, was associated with maintenance of treatment gains and a low incidence of relapse in adults who stutter after completion of therapy. Methods: In this prospective longitudinal study, 40 adults who stutter completed structured treatment and entered post-treatment follow-up. Nineteen completed 24 months of monthly monitoring, involving a monthly self-rated five-point Speech Satisfaction Rating Scale (SSRS) to track perceived speech satisfaction and to detect relapse, defined a priori as a sustained decline in satisfaction relative to the post-treatment rating. No additional therapy was provided during follow-up. Results: Across the 24-month follow-up period, one participant (5.3%) met the predefined criterion for sustained relapse; six participants (32%) showed a transient two-point decline in satisfaction at one or more follow-up points, which had resolved by 24 months in all but one. Speech satisfaction increased significantly from pre-treatment to post-treatment (p < 0.001) and remained significantly higher at 24 months compared with pre-treatment levels (p < 0.001). Although a modest reduction in speech satisfaction was observed at 12 months (p = 0.048), no significant difference was found between post-treatment and 24-month follow-up scores (p = 0.109). Longitudinal analysis demonstrated a significant effect of time on speech satisfaction (p < 0.001), with no significant effects of age or gender. Conclusions: Sustained clinical follow-up without additional therapy was associated with long-term maintenance of self-rated speech satisfaction and a low incidence of sustained relapse over 24 months. These findings suggest that structured follow-up may be a useful component of relapse monitoring in stuttering management, although the single-group design and reliance on a single self-report measure limit causal interpretation. Full article

Sprint performance improves throughout adolescence as a result of both structural and neuromuscular development. In particular, increases in body height, lower limb length, and muscle volume have been consistently linked to improvements in sprint performance. However, allometric scaling of force, speed, and power remain lower in adolescents compared to adults even after structural differences are accounted for, implicating neural factors as independent contributors to performance development. The purpose of this study was to investigate differences in neuromuscular activation patterns of the lower limb muscles during maximal sprinting between youth male athletes across two age groups (U19: 17–19 years; U16: 13–16 years). Eighteen athletes performed a 50 m maximal sprint. Spatiotemporal variables (running speed, step frequency, step length) were measured over 30–50 m using a high-speed camera (240 Hz) and timing gates. Electromyographic (EMG) signals were recorded simultaneously from ten lower limb muscles using wireless EMG sensors (2000 Hz): rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), gluteus maximus (Gmax), gluteus medius (Gmed), vastus lateralis (VL), vastus medialis (VM), tibialis anterior (TA), gastrocnemius (GAS), and soleus (SOL). Root mean square (RMS) amplitude was calculated across four gait phases (contact, early-swing, mid-swing, late-swing) and normalised to maximal voluntary Isometric contraction (%MVIC). The U19 group demonstrated significantly greater running speed (U19: 9.49 ± 0.39 vs. U16: 8.67 ± 0.25 m·s⁻¹, p < 0.001), step frequency (U19: 4.49 ± 0.12 vs. U16: 4.35 ± 0.16 Hz, p = 0.004), and step length (U19: 2.12 ± 0.12 vs. U16: 1.99 ± 0.06 m, p = 0.010) than U16. The overall pattern of lower limb muscle activation across the gait cycle was broadly similar between groups; however, a significant group × phase interaction was observed for RF (p = 0.003, F = 5.257, η² = 0.247), with post hoc analysis revealing greater RF activation during early swing in U19 (p = 0.033). These findings may indicate that sprint-specific training in youth athletes is associated with not only structural but also neuromuscular differences, specifically reflecting enhanced RF recruitment during the phase-critical moment of early swing—a window in which high-threshold motor unit activation is most mechanically decisive. EMG-based assessment of hip flexor activation during maximal sprinting may provide a complementary tool, pending further validation, for talent identification and training prescription in youth track and field. Full article

Metro train-induced environmental vibrations may adversely affect the performance and comfort of buildings near metro lines, making it necessary to select suitable isolation barrier materials for vibration control. To evaluate the vibration isolation performance of different barrier materials, a vehicle–track coupled dynamic model and a three-dimensional tunnel-soil-structure finite element model were established to predict vibration sources and structural responses. Based on wave propagation characteristics and impedance theory, an impedance-based material selection approach for isolation barriers was proposed. Concrete and foam were selected as representative high- and low-impedance materials, respectively, and were compared with open trenches to evaluate their isolation performance and control mechanisms. Results indicate that building vibrations are mainly concentrated within 20–80 Hz, with dominant peaks around 40–50 Hz. Open trenches provide the most effective low-frequency attenuation, foam-filled trenches achieve stable broadband isolation, and concrete walls are mainly effective at mid-to-high frequencies. Low-impedance filled trenches offer a favorable balance between vibration reduction and engineering feasibility. The findings provide a reference for the design and selection of isolation barriers for buildings adjacent to underground metro tunnels. Full article