Search Results (399)

Lower limb functional degeneration has become prevalent, notably reducing the core strength that drives motor control. Squats are frequently used in lower limb training, improving overall muscle strength. However, performing continuously with improper techniques can lead to dynamic knee instability. It worsens with little to no motivation to perform these power training motions. Hence, it is crucial to have a gaming-based exercise tracking system to adaptively enhance the user experience without causing injury or falls. In this work, 28 healthy subjects performed exergame-based squat training, and dynamic kinematic features were recorded. The five features acquired from a depth camera-based inertial measurement unit (IMU) (1—Knee shakiness, 2—Knee distance, and 3—Squat depth) and an Anima forceplate sensor (4—Sway velocity and 5—Sway area) were assessed using a Spearman correlation coefficient-based feature selection method. An input vector that defines knee instability is used to train and test the Long Short-Term Memory (LSTM) and Support Vector Machine (SVM) models for binary classification. The results showed that knee instability events can be successfully classified and achieved a high accuracy of 96% in both models with sets 1, 2, 3, 4, and 5 and 1, 2, and 3. The feature selection results indicate that the LSTM network with the proposed combination of input features from multimodal sensors can successfully perform real-time tracking of knee instability. Furthermore, the findings demonstrate that this multimodal approach yields improved classifier performance with enhanced accuracy compared to using features from a single modality during lower limb therapy. Full article

Background/Objectives: Continuous renal replacement therapy (CRRT) is a critical intervention for managing acute kidney injury (AKI) in critically ill patients. Critical care nurses (CCNs) play a pivotal role in its implementation, requiring adequate knowledge, a positive attitude, and practice proficiency. This study aimed to assess the levels and factors affecting CCNs’ knowledge, attitudes, and practices (KAPs) regarding the care of patients receiving CRRT in Hail Hospitals, Saudi Arabia. Methods: A cross-sectional study was conducted with 190 registered CCNs from the critical care units of Hail Hospitals, Saudi Arabia, from March to May 2025. Data were collected using a sociodemographic characteristics sheet and the knowledge, attitudes, and practices questionnaire on CRRT. Non-parametric statistical tests (Mann–Whitney U, Kruskal–Wallis, and Spearman’s correlation tests) were used to determine the relationships between variables. A multiple linear regression analysis was used to explore the factors affecting the study variables. Results: The majority of CCNs had a high level of knowledge regarding CRRT management (66.3%), followed by moderate (21.1%) and low (16.6%) levels. Additionally, the majority had a high level of attitude regarding CRRT management (74.7%), followed by moderate (18.4%) and low (6.9%) levels. The majority of CCNs had a high level of practice regarding CRRT management (66.8%), followed by low (23.7%) and moderate (9.5%) levels. There was a significant positive correlation between CCNs’ knowledge, attitudes (rs = 0.230, p < 0.001), and practices (rs = 0.192, p < 0.001). Additionally, there was a significant positive correlation between CCNs’ attitudes and practices (r = 0.419, p < 0.001). Multiple linear regression revealed a significant model (p  <  0.001) when sociodemographic and work-related factors were analyzed as predictors of CCNs’ levels of knowledge, attitudes, and practices regarding CRRT: Having more experience, working with a nurse-to-patient ratio of 1:2, and frequently using CVVHDF as a CRRT modality were significant factors for higher knowledge levels when compared to the reference categories. In addition, having a bachelor’s degree and frequently using CVVHD, CVVHDF, or SCUF as a CRRT modality were significant factors for higher attitude levels regarding CRRT when compared to the reference categories. Having a bachelor’s degree and frequently using CVVHD or CVVHDF as a CRRT modality were significant factors for higher practice levels regarding CRRT when compared to the reference categories. Conclusions: CCNs in Hail Hospitals self-reported high levels of knowledge, attitudes, and practices regarding CRRT management, followed by moderate levels. Targeted educational programs, standardized protocols, and organizational support are recommended to improve CCN care for CRRT and to optimize patient outcomes. Full article

Objectives: The lat pulldown machine is one of the most versatile pieces of equipment for back strengthening, allowing variations in grip and load. However, there are significant gaps in the literature regarding the relationship between exercise modality and specific muscle activation. Methods: This study examined the electromyographic (EMG) activity of major back muscles during seven lat pulldown exercise variants that differed in grip type, width, and trunk inclination. Forty male subjects, with at least 5 years of resistance training experience, performed five repetitions of lat pulldown exercise using 70% of their repetition maximum. Prior to the surface EMG analysis, maximal voluntary contraction (MVC) tests were performed for each muscle group analysed, specifically the latissimus dorsi, posterior deltoid, brachial biceps, middle and lower trapezium, and infraspinatus. The normalised root mean square of the EMG (NrmsEMG) activity for each muscle was recorded during full, concentric, and eccentric movements. Results: Multivariate analysis of variance (MANOVA) showed no significant difference in the NrmsEMG muscle activation across the different lat pulldown exercise variations (all p > 0.05). A significant difference was found in the posterior deltoid where the wide-pronated grip with a 30° trunk inclination showed greater EMG activation compared to the wide pronated grip (p = 0.011) and wide neutral grip (p = 0.017). Conclusions: These findings suggest that grip variations may not significantly alter latissimus dorsi recruitment, challenging the assumption that grip effectiveness targets this muscle. The results highlight the need for individualised approaches to exercise selection, given the variability in muscle activation patterns observed. Full article

To address the limitations of low fusion efficiency and insufficient personalization in multimodal perception for educational intelligence, a novel deep learning framework is proposed that integrates image sensor data with textual and contextual information through a cross-modal attention mechanism. The architecture employs a cross-modal alignment module to achieve fine-grained semantic correspondence between visual features captured by image sensors and associated textual elements, followed by a personalized feedback generator that incorporates learner background and task context embeddings to produce adaptive educational guidance. A cognitive weakness highlighter is introduced to enhance the discriminability of task-relevant features, enabling explicit localization and interpretation of conceptual gaps. Experiments show the proposed method outperforms conventional fusion and unimodal baselines with 92.37% accuracy, 91.28% recall, and 90.84% precision. Cross-task and noise-robustness tests confirm its stability, while ablation studies highlight the fusion module’s +4.2% accuracy gain and the attention mechanism’s +3.8% recall and +3.5% precision improvements. These results establish the proposed method as a transferable, high-performance solution for next-generation adaptive learning systems, offering precise, explainable, and context-aware feedback grounded in advanced multimodal perception modeling. Full article

The linear rolling guide (LRG) is widely used in the computer numerical control machine tool industry and other industries. To accurately evaluate the performance of LRGs, a multi-parameter test bench was developed to measure motion accuracy, preload drag force (PDF), vibration, temperature rise, and fatigue life. The mechanical structure and measurement and control system of the test bench were designed based on established principles and methods. ANSYS 19.0 software was used for static analysis of the gantry, modal analysis of the upper bed, and simulation of the impact of loading block thickness on load distribution uniformity. At the same time, we used an impact hammer modal test to verify the correctness of the finite element analysis of the upper bed. The analysis results validated the structural design. To verify the test bench’s repeatability, comparative experiments were conducted with the Hilectro LGD35-type LRGs, focusing on motion accuracy, PDF, and fatigue life. The experimental results confirmed the test bench’s high repeatability and validated the derived equations for measuring motion accuracy. Full article

Ground engaging tools (GETs) are critical consumable components on mining excavators, and their timely replacement is essential to prevent risks and excessive downtime. This paper presents a monitoring method utilising the modal properties—natural frequencies and mode shapes. The method is applied in a test case to show how the GETs on an excavator bucket could be monitored. Modal analysis and dynamic analysis are conducted with ANSYS to verify the effectiveness of the proposed method. The finite element analysis models are validated by experimental vibration experiments. The results demonstrate a strong correlation between changes in natural frequencies and the conditions of the teeth on the excavator bucket, when comparing the intact to the worn-out condition. In conclusion, the presented method offers a promising approach for real-time monitoring of the GETs on mining excavators and similar equipment. It will contribute to efficient maintenance interventions and enhancing operational efficiency and safety. Full article

Tissue chips (TCs), otherwise known as organs-on-a-chip (OoC), organ chips (OCs), or microphysiological systems (MPS), are rapidly gaining prominence as an extension of or even replacement for traditional animal models of disease physiology. They also have recognized utility in the context of drug development: for example, data from TCs can now be submitted in place of some animal testing to the FDA. In principle, TCs are structured to allow measurement of any number of outputs that yield information about the tissue. However, to date, measurements made during experiments with TCs have been largely restricted to immunofluorescence microscopy and benchtop assays performed on media extracted from the cell culture within the device. With the development of biosensors that are sensitive and have an ever-shrinking footprint, on-board biosensing is now in the early stages of exploration. This review discusses the importance of tissue chips and the advances in sensing that will aid the complexity and utility of tissue chip research moving forward. We cover several sensing modalities, including electrical and optical sensing modes. Finally, challenges and opportunities for the future are discussed. Full article

The quality of white wine is related to sensory attributes like color, odor and taste. This study focused mainly on taste attributes of white wines. The research hypothesis was to find out if taste-related attributes alone, determined by sensory experiment, could discriminate Chardonnay versus non-Chardonnay wines. Sensory analyses were performed with a trained panel on commercial white wines made from single varieties. Black glasses and nose clips were used to remove sensory interference and to first assess only taste attributes. Initial tests were then performed to evaluate the possibility to discriminate against Chardonnay wines only due to taste. In a second series of experiments, Rate All That Apply (RATA) experiments were performed in a set of Chardonnay versus non-Chardonnay wines. An initial sensory experiment revealed that some of the Chardonnay wines could be discriminated against by taste only but that recognition by using olfaction was more powerful which confirmed our research hypothesis in part. The second series of RATA sensory analysis revealed that some specific descriptors such as fat, salt, bitter and acid are involved in the taste discrimination of Chardonnay versus non-Chardonnay wines, especially with Sauvignon Blanc wines. These findings suggest that while modal sensory approach remains more robust for varietal identification, taste alone offers some discriminatory power. Full article

Addressing the issues of coarse emotional representation, low cross-modal alignment efficiency, and insufficient real-time response capabilities in current human–computer emotional language interaction, this paper proposes an affective interaction framework integrating BERT-based semantic understanding with VITS-based speech synthesis. The framework aims to enhance the naturalness, expressiveness, and response efficiency of human–computer emotional interaction. By introducing a modular layered design, a six-dimensional emotional space, a gated attention mechanism, and a dynamic model scheduling strategy, the system overcomes challenges such as limited emotional representation, modality misalignment, and high-latency responses. Experimental results demonstrate that the framework achieves superior performance in speech synthesis quality (MOS: 4.35), emotion recognition accuracy (91.6%), and response latency (<1.2 s), outperforming baseline models like Tacotron2 and FastSpeech2. Through model lightweighting, GPU parallel inference, and load balancing optimization, the system validates its robustness and generalizability across English and Chinese corpora in cross-linguistic tests. The modular architecture and dynamic scheduling ensure scalability and efficiency, enabling a more humanized and immersive interaction experience in typical application scenarios such as psychological companionship, intelligent education, and high-concurrency customer service. This study provides an effective technical pathway for developing the next generation of personalized and immersive affective intelligent interaction systems. Full article

Enhanced Geothermal Systems (EGS) require thermochemically stable proppant materials capable of sustaining fracture conductivity under harsh subsurface conditions. This study systematically investigates the response of commercial proppants to coupled thermo-hydro-chemical (THC) effects, focusing on chemical stability and microstructural evolution. Four proppant types were evaluated: an ultra-low-density ceramic (ULD), a resin-coated sand (RCS), and two quartz-based silica sands. Experiments were conducted under simulated EGS conditions at 130 °C with daily thermal cycling over a 25-day period, using diluted site-specific Utah FORGE geothermal fluids. Static batch reactions were followed by comprehensive multi-modal characterization, including scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), and micro-computed tomography (micro-CT). Proppants were tested in both granular and powdered forms to evaluate surface area effects and potential long-term reactivity. Results indicate that ULD proppants experienced notable resin degradation and secondary mineral precipitation within internal pore networks, evidenced by a 30.4% reduction in intragranular porosity (from CT analysis) and diminished amorphous peaks in the XRD spectra. RCS proppants exhibited a significant loss of surface carbon content from 72.98% to 53.05%, consistent with resin breakdown observed via SEM imaging. While the quartz-based sand proppants remained morphologically intact at the macro-scale, SEM-EDS revealed localized surface alteration and mineral precipitation. The brown sand proppant, in particular, showed the most extensive surface precipitation, with a 15.2% increase in newly detected mineral phases. These findings advance understanding of proppant–fluid interactions under low-temperature EGS conditions and underscore the importance of selecting proppants based on thermo-chemical compatibility. The results also highlight the need for continued development of chemically resilient proppant formulations tailored for long-term geothermal applications. Full article

Coronary artery disease (CAD) is the third leading cause of disability and death globally. Intravascular ultrasound (IVUS) is the most commonly used imaging modality for the characterization of vulnerable plaques. The development of novel intravascular imaging and therapy devices requires dedicated open systems (e.g., for pulse sequences for imaging or thrombolysis), which are not currently available. This paper presents the development of a novel multifunctional FPGA-based pulser/receiver system for intravascular ultrasound imaging and therapy research. The open platform consists of a host PC with a Matlab-based software interface, an FPGA board, and a proprietary analog front-end board with state-of-the-art electronics for highly flexible transmission and reception schemes. The main features of the system include the capability to convert arbitrary waveforms into tristate bipolar pulses by using the PWM technique and by the direct acquisition of raw radiofrequency (RF) echo data. The results of a multicycle excitation pulse applied to a custom 550 kHz therapy transducer for acoustic characterization and a pulse-echo experiment conducted with a high-voltage, short-pulse excitation for a 19.48 MHz transducer are reported. Testing results show that the proposed system can be easily controlled to match the frequency and bandwidth required for different IVUS transducers across a broad class of applications. Full article

Virtual reality (VR) can enrich neuropsychological testing, yet the ergonomic trade-offs of its input modes remain under-examined. Seventy-seven healthy volunteers—young (19–29 y) and middle-aged (35–56 y)—completed a VR Trail Making Test with three pointing methods: eye-tracking, head-gaze, and a six-degree-of-freedom hand controller. Completion time, spatial accuracy, and error counts for the simple (Trail A) and alternating (Trail B) sequences were analysed in 3 × 2 × 2 mixed-model ANOVAs; post-trial scales captured usability (SUS), user experience (UEQ-S), and acceptability. Age dominated behaviour: younger adults were reliably faster, more precise, and less error-prone. Against this backdrop, input modality mattered. Eye-tracking yielded the best spatial accuracy and shortened Trail A time relative to manual control; head-gaze matched eye-tracking on Trail A speed and became the quickest, least error-prone option on Trail B. Controllers lagged on every metric. Subjective ratings were high across the board, with only a small usability dip in middle-aged low-gamers. Overall, gaze-based ray-casting clearly outperformed manual pointing, but optimal choice depended on task demands: eye-tracking maximised spatial precision, whereas head-gaze offered calibration-free enhanced speed and error-avoidance under heavier cognitive load. TMT-VR appears to be accurate, engaging, and ergonomically adaptable assessment, yet it requires age-specific–stratified norms. Full article

Due to its superior maneuverability and concealment, the micro flapping-wing aircraft has great application prospects in both military and civilian fields. However, the development and optimization of lightweight materials have always been the key factors limiting performance enhancement. This paper designs the flapping mechanism of a single-degree-of-freedom miniature flapping wing aircraft. In this study, T800 carbon fiber composite material was used as the frame material. Three typical wing membrane materials, namely polyethylene terephthalate (PET), polyimide (PI), and non-woven kite fabric, were selected for comparative analysis. Three flapping wing configurations with different stiffness were proposed. These wings adopted carbon fiber composite material frames. The wing membrane material is bonded to the frame through a coating. Inspired by bionics, a flapping wing that mimics the membrane vein structure of insect wings is designed. By changing the type of membrane material and the distribution of carbon fiber composite materials on the wing, the stiffness of the flapping wing can be controlled, thereby affecting the mechanical properties of the flapping wing aircraft. The modal analysis of the flapping-wing structure was conducted using the finite element analysis method, and the experimental prototype was fabricated by using 3D printing technology. To evaluate the influence of different wing membrane materials on lift performance, a high-precision force measurement experimental platform was built, systematic tests were carried out, and the lift characteristics under different flapping frequencies were analyzed. Through computational modeling and experiments, it has been proven that under the same flapping wing frequency, the T800 carbon fiber composite material frame can significantly improve the stiffness and durability of the flapping wing. In addition, the selection of wing membrane materials has a significant impact on lift performance. Among the test materials, the PET wing film demonstrated excellent stability and lift performance under high-frequency conditions. This research provides crucial experimental evidence for the optimal selection of wing membrane materials for micro flapping-wing aircraft, verifies the application potential of T800 carbon fiber composite materials in micro flapping-wing aircraft, and opens up new avenues for the application of advanced composite materials in high-performance micro flapping-wing aircraft. Full article

Background/Objectives: Extraction and replacement of hopeless teeth is a common practice in dentistry. Tooth autotransplantation (TA) offers several advantages as a viable and biological treatment option. However, its utilization in Saudi Arabia appears limited. Understanding dentists’ knowledge and attitudes toward TA is crucial for promoting its adoption in clinical practice. Therefore, the aim of this study is to assess the knowledge and attitudes of dentists in Saudi Arabia toward tooth autotransplantation. Methods: A cross-sectional study was conducted using a web-based questionnaire distributed to dentists across Saudi Arabia. The questionnaire included 19 questions assessing demographic characteristics, knowledge of TA, and attitudes toward its clinical application. Data were analyzed using SPSS v23 with chi-square and Cramér’s V tests to explore associations between variables (p < 0.05). Results: 253 dentists participated in this study. All participants had heard of TA, while only 26.5% reported moderate-to-high familiarity. Female dentists showed significantly greater interest in adopting TA than males (p = 0.038, Cramér’s V = 0.183). Specialists expressed higher familiarity than general dentists and underscored the importance of clinical guidelines, evidence-based outcomes, confidence in their capacity to engage in a TA team, the total number of required appointments, and malpractice concerns (p < 0.05) in their decision-making process. Nevertheless, general dentists demonstrated significantly more interest in implementing TA (p = 0.025, Cramér’s V = 0.192). Participants with more than 5 years of clinical dental experience were significantly more familiar with TA (p = 0.015, Cramér’s V = 0.204) and were more influenced by appointment numbers in decision-making (p = 0.012, Cramér’s V = 0.225). Conclusions: The study reveals limited familiarity but notable interest among dentists in Saudi Arabia toward TA. Addressing educational gaps by integrating TA training into dental curricula and offering clinical exposure opportunities to students, along with providing evidence-based clinical guidelines, and improving access to advanced imaging technologies, may enhance the adoption of TA as a viable treatment modality for tooth replacement. Full article

Accurate diagnosis of the insulation condition of stator windings in pumped storage generator-motor units is crucial for ensuring the safe and stable operation of power systems. Time domain dielectric response testing is an effective method for rapidly diagnosing the insulation condition of capacitive devices, such as those in pumped storage generator-motors. To precisely identify the conductivity and relaxation process parameters of the insulating medium and accurately diagnose the insulation condition of the stator windings, this paper proposes a method for identifying the insulation dielectric response parameters of stator windings based on sparsity-enhanced dynamic mode decomposition of the depolarization current. First, the measured depolarization current time series is processed through dynamic mode decomposition (DMD). An iterative reweighted L1 (IRL1)-based method is proposed to formulate a reconstruction error minimization problem, which is solved using the ADMM algorithm. Based on the computed modal amplitudes, the dominant modes—representing the main insulation relaxation characteristics—are separated from spurious modes caused by noise. The parameters of the extended Debye model (EDM) are then calculated from the dominant modes, enabling precise identification of the relaxation characteristic parameters. Finally, the accuracy and feasibility of the proposed method are verified through a combination of simulation experiments and laboratory tests. Full article