Search Results (30,205)

Efficiently converting natural capital into economic assets is a critical challenge in urban–rural transformation, yet the interactive mechanism between institutional land reform and physical spatial restructuring remains underexplored. While traditional frameworks emphasize institutional design, this study identifies a “Spatial-First” mechanism where physical reconfiguration serves as a spatial mediator to catalyze property rights breakthroughs. Using an entropy-weighted coupling coordination model, we analyzed policy dynamics in Nanhai District, China, a unique “dual-pilot” zone, from 2020 to 2024. The results indicate a nonlinear leap in the Coupling Coordination Degree (D) from 0.100 to 0.978. We interpret this surge as a policy-driven shock during the intensive pilot phase, where substantive spatial integration (0.719) effectively bypassed high transaction costs inherent in collective tenure, outpacing institutional progress (0.281). However, an Ecological Lag was observed; the disproportionately low weighting of the ecological carrier index (7.09%) suggests that current gains are primarily driven by green industrialization rather than the expansion of absolute ecological stock. This study concludes that while spatial tools can effectively unlock natural capital value in the short term, long-term sustainability necessitates a strategic shift from administrative-led economic efficiency to market-based ecological restoration. Full article

Recently, distributed DC microgrids have gained prominence due to their modular design, scalability, and seamless integration with renewable energy sources. However, ensuring robust operation of distributed secondary control schemes remains challenging, particularly in the presence of unavoidable communication disruptions and parametric uncertainties encountered in practice. Most existing control strategies either assume ideal communication networks or address fault tolerance and communication constraints separately, which limits their applicability in realistic networked environments. This paper proposes an event-triggered fault-tolerant distributed secondary control framework for DC microgrids operating under communication faults. An embedded averaged model is incorporated to support fault-tolerant decision-making and to guide event-triggered communication updates. In addition, an auxiliary recovery mechanism is introduced, enabling neighboring converters to cooperatively compensate for information loss during communication interruptions without centralized supervision. Lyapunov-based stability analysis establishes boundedness and practical convergence of the closed-loop system under event-triggered updates and bounded disturbances while explicitly excluding Zeno behavior. The simulation results under communication fault scenarios demonstrate that the proposed approach achieves accurate DC bus voltage regulation with steady-state deviations below 1% while restoring proportional power sharing with an averaged error within 5%. The embedded model error remains bounded throughout the fault interval, and fault-tolerant control actions are triggered sparsely with well-separated inter-event times on the order of tens of milliseconds, thereby significantly reducing the communication burden. These results confirm the effectiveness and robustness of the proposed framework for the resilient operation of distributed DC microgrids under practical communication constraints. Full article

In view of the bottleneck problems existing in the 3D ultrasonic testing of aircraft composite laminated structures—including heavy reliance on manual operation, resulting in low detection efficiency, and the inability of traditional robotic arms to adapt to the testing of complex curved surfaces due to their dependence on predefined fixed trajectories—this paper proposes an automated 3D ultrasonic testing method based on 3D vision guidance for robotic arms. Firstly, the proposed Yolo-Mask model is adopted to realize the visual recognition and segmentation of composite component regions, after which the segmentation results are mapped to the depth map and further converted into the surface point cloud of the material. Secondly, on the basis of point cloud preprocessing and trajectory point extraction, the automatic planning of the robotic arm’s scanning trajectory is achieved, which drives the robotic arm to perform precise motion and to synchronously collect spatial pose and ultrasonic testing data. Finally, 3D reconstruction is completed via a fusion algorithm, and 3D images of the material’s internal structures are generated. Experimental verification shows that the proposed method achieves a Segm-mAP of 97.4%, a detection speed of 11.7 fps, and a 3D imaging error of less than 0.1 mm, thereby realizing fully automated detection throughout the entire process. This research provides an effective solution for the non-destructive testing of aircraft composite structures. Full article

Background/Objectives: This study aims to develop a comprehensive Clinical Decision Support System (CDSS) that integrates multi-sequence sacroiliac joint (SIJ) MRIs with rheumatological, clinical, and laboratory findings into the decision-making process for the early diagnosis of axial spondyloarthritis (axSpA), incorporating segmentation-supported explainability. Methods: Multi-sequence SIJ MRI data (T1-WI, T2-WI, STIR, and PD-WI) were analysed from 367 participants (n = 193 axSpA; n = 174 non-axSpA controls). Sequence-based classification was performed using VGG16, ResNet50, DenseNet121, and InceptionV3 models; additionally, a lightweight and parameter-efficient SacroNet architecture was developed. Slice-level probability scores were converted to patient-level scores using the Dynamic Top-K Averaging method. Image-based scores were combined with a logistic regression-based clinical risk score using weighted linear integration (0.60 image/0.40 clinical) and a conservative threshold (τ = 0.70). Grad-CAM was applied for visual interpretability. Furthermore, to support the diagnostic outcomes with precise spatial data, active inflammation in STIR and T2-WI sequences was segmented. For this purpose, the MDC-UNet model was employed and compared with baseline U-Net derivatives. Results: Sequence-specific analysis showed VGG16 performing best on T1-WI (AUC = 0.920; Accuracy = 0.878) and DenseNet121 on STIR (AUC = 0.793; Accuracy = 0.771). The SacroNet architecture provided competitive classification performance at the patient level despite its low number of parameters (~110 K). Furthermore, MDC-UNet successfully segmented active inflammation, yielding Dice scores of 0.752 (HD95: 19.25) for STIR and 0.682 (HD95: 26.21) for T2-WI. Conclusions: The findings demonstrate that patient-level decision integration based on multi-sequence MRI, when used in conjunction with clinical risk scoring and segmentation-assisted interpretability, can provide a feasible and interpretable DSS framework for the early diagnosis of axSpA. Full article

With the proliferation of multimodal content on social media, creators increasingly require tools that can retrieve both images and videos relevant to a single textual query. However, existing cross-modal retrieval methods are typically confined to binary (text–image or text–video) settings and struggle with fine-grained semantic alignment and spatiotemporal information imbalance. To address this issue, we propose UniTriM, a unified framework for text–image–video joint retrieval. First, UniTriM supports concurrent retrieval of semantically relevant images and videos given one textual input. To overcome the scarcity of text–image–video triplet data, we introduce a self-attention-based keyframe selection strategy that converts existing text–video datasets into triplet format. Second, we design a multi-granularity similarity alignment module that captures hierarchical semantics by modeling patch–frame–video and word–triple–sentence structures and jointly optimizes intra- and cross-granularity alignments to enhance fine-grained cross-modal correspondence. Third, to alleviate the inherent spatiotemporal information imbalance between static images and video-aligned text descriptions, we introduce a feature disentanglement module that disentangles spatial-related features from text and aligns them explicitly with image representations. Experiments conducted on three benchmark datasets MSR-VTT, MSVD, and DiDeMo demonstrate that UniTriM achieves state-of-the-art performance on joint retrieval tasks. Full article

This work presents an alternating sequential model predictive control (ASMPC) scheme applied to multimodular matrix converters. The proposed strategy alternately evaluates two control objectives: load current tracking and input reactive power minimization. The algorithm was implemented in MATLAB/Simulink on an architecture composed of two direct matrix converters in a multimodular configuration. The influence of parameter $N_2$ on system performance was analyzed under step changes in reference current of 30 A and 60 A. To this end, performance metrics such as THD and MSE were used, along with a descriptive statistical analysis including the mean, standard deviation, mean absolute deviation (MAD), and coefficient of variation (CV). Simulation results show stable performance for variations in $N_2$, with an input current THD of $8.10\%$ and load THD reduced to $1.00\%$, demonstrating improved harmonic performance compared with classical weighted MPC approaches. Full article

This study develops and tests an Engagement–Experience–Co-creation–Loyalty (EECL) framework explaining how hospitality brand engagement (HBE) is translated into multidimensional hotel loyalty through two parallel mechanisms: Hospitality brand experience (HBX) and hospitality value co-creation (HVCC). A variance-based PLS-SEM model with seven reflective latent constructs and 57 indicators was estimated using data from 1407 members of four global hotel loyalty programs; generational cohort was used only as a grouping variable in multi-group analysis, not as an additional construct. MICOM established measurement invariance across Generation Z, Millennials, Generation X, and Baby Boomers. HBE is positively associated with both HBX and HVCC, and both mechanisms transmit its relationship to cognitive, affective, and conative loyalty. These three attitudinal facets jointly predict action loyalty, supporting a parallel rather than strictly staged loyalty-formation logic in hotel loyalty-program contexts. Younger cohorts translate engagement more strongly into experience and co-creation, whereas older cohorts rely more on experience when forming cognitive loyalty. The study contributes a hospitality-specific, predictive, and cohort-sensitive explanation of how engagement is converted into hotel loyalty. Full article

As secondary educational environments face increasing volatility due to systemic resource constraints and pedagogical uncertainty, understanding the behavioral mechanisms of teacher agency has become paramount. While traditional teacher education has emphasized the execution of standardized curricula, the current era demands a fundamental shift toward adaptive expertise and psychological resilience. This study investigates the processes by which 28 secondary pre-service physical education teachers (PSTs) navigate instructional resource deficits through the lens of adaptive behavior (bricolage) and ecological teacher agency. Utilizing a qualitative case study design, I collected data from two universities in Seoul, South Korea, through reflective journals, revised lesson plans, and micro-teaching video analysis reports over a full 15-week semester. The results identified five coordinates of an adaptive instructional design compass: (1) Facing Constraints, (2) Resource Mining, (3) Contextual Engineering, (4) Simulation, and (5) Reflective Participation. These coordinates represent a transformative behavioral process where PSTs convert environmental deficits into professional assets. The findings reveal distinct adaptation styles based on psychological dispositions: the analytically oriented group (Group A) prioritized structural redesign through digital tools, while the narratively oriented group (Group B) utilized human-centric somatic metaphors and virtual rehearsals to bridge the epistemic void. Crucially, this research suggests that teacher adaptation is not a mere technical adjustment but a dynamic behavioral achievement of agency that ensures the long-term instructional quality of physical education. I propose that teacher education programs should incorporate “Safe Deficit” simulations—carefully calibrated instructional constraints—to trigger adaptive behavior and ensure that future educators can thrive in unpredictable pedagogical contexts without the risk of professional burnout. Full article

Expanded polystyrene (EPS) waste poses a major environmental concern due to its high volume, low density, and resistance to biodegradation. In this study, post-consumer EPS was reprocessed into continuous microfibers by Air Jet Spinning (AJS) using chloroform and chloroform/D-limonene as solvent systems. The effects of polymer concentration, air pressure, and solvent ratio on fiber formation were systematically investigated through rheological and surface tension analyses. The incorporation of 10 vol. % D-limonene improved jet stability and reduced bead formation, attributed to its lower volatility and favorable solubility with EPS, as supported by Hansen solubility parameters. SEM analysis confirmed uniform microfiber formation within a defined processing window. FTIR spectra indicated preservation of the polystyrene chemical structure, while TGA and DSC analyses were used to evaluate thermal behavior and assess potential residual solvent retention, particularly related to D-limonene. The results elucidate the interplay between solvent volatility, solution properties, and fiber morphology, establishing a sustainable processing framework for converting EPS waste into value-added fibrous materials via AJS. This work contributes to the United National Sustainable Development Goals, particularly SDG 12 (Responsible Consumption and Production) by promoting EPS waste valorization, and SDG 13 (Climate Action) through the partial replacement of conventional solvents with sustainable alternative. Full article

Northeast China has undergone large-scale cultivation of agricultural land, accompanied by internal restructuring of paddy fields and rain-fed farmland. Such a land change process has an obvious impact on the ecosystem. However, the quantitative effects of long-term cultivation of land/internal structure on the eco-environment are still lacking in the Heilongjiang region, China’s ecological barrier and grain base. To address this academic issue, the integrated method of land update technology, dynamic tracking, remote sensing classification, and improved ecosystem services were applied using satellite imagery and land products. Through satellite monitoring, the area of cultivated land changed from 127,221.71 to 173,665.12 km², with an increment of 46,443.41 km², expanding the central–northern parts and the eastern part over the past half-century. In different regions, all cities have undergone varying degrees of reclamation rate expansion ranging 0.71–29.62%. Regarding the structure, a quarter of the study area was covered by rain-fed farmland (25.29%), but the cultivation level of paddy fields (2.83%) was very low in 1970; after that, only a 13.08% increment in rain-fed farmland but a high increase of 246.14% in paddy fields was monitored from 1970 to 2020. Meanwhile, the source area of cultivated land was 59,271.48 km², with 60.41% from forest and grassland of the agricultural-forestry ecotone. Its destination area was 12,827.11 km², and 78.49% of the total was converted to construction land, forest, and grassland. From 1970 to 2020, the evaluated ecosystem service changed from 15,575.87 to 12,495.72 × 10⁸ yuan, showing a total loss of 3080.15 × 10⁸ yuan and an annual turnover rate of 0.40%. An important calculation indicated that the expansion and shrinkage of cultivated land led to a 2303.46 × 10⁸ yuan loss, which means that three-quarters (i.e., 74.78%) of ecosystem service loss was caused by cultivated land changes. Another key finding was that a large transformation of wetland into paddy fields brought about the huge loss of 847.85 × 10⁸ yuan; by contrast, the process of extensive rain-fed farmland turning into paddy fields was only a small change of 3.38 × 10⁸ yuan. Considering the ecological loss caused by cultivated land, the projects of returning farmland to forests and wetland protection should be implemented. This study provided important references for land system monitoring and environmental impact assessment in high-latitude regions around the world. Full article

Conventional control strategies for battery energy storage systems (BESSs) fail to achieve symmetrical and coordinated control between the DC/DC and DC/AC conversion stages, resulting in unsatisfactory DC capacitor voltage fluctuation suppression and threatening the safe and stable operation of the system. To address this issue, this study proposes an improved model predictive control (MPC)-based control method that explicitly considers DC capacitor voltage fluctuation suppression. First, a dynamic mathematical model of the BESS is established by jointly considering its DC/DC and DC/AC energy conversion stages. The model is then discretized using the first-order forward Euler method to facilitate controller implementation. Second, the cost function of the proposed MPC-based control method is designed to simultaneously incorporate DC capacitor voltage fluctuation suppression and output current tracking errors on both the DC and AC sides. Finally, the switching states of the DC and AC converters are selected as the control set, and the optimal switching signals for the BESS are determined by optimizing the aforementioned cost function. Verification results demonstrate that, compared with traditional control strategies, the proposed strategy achieves more symmetrical stable and dynamic performance and reduces DC side capacitor voltage fluctuation by approximately 80%, thereby effectively ensuring the safe and stable operation of the system. Full article

Background: Tuberculosis (TB) has long been suspected to contribute to lung carcinogenesis through chronic inflammation and immune dysregulation. However, contemporary controlled evidence quantifying this association remains limited. We aimed to systematically evaluate the relationship between prior TB and subsequent lung malignancy, using recent observational studies and complementary case reports. Methods: A systematic review and random-effects meta-analysis were conducted, including controlled cohort and case–control studies published from 2020 onward. Adjusted effect estimates were converted to the logarithmic scale for pooling. Heterogeneity and small-study effects were assessed using standard meta-analytic techniques. Additionally, published case reports were descriptively analyzed to explore clinicopathological patterns. Results: Across eligible studies, prior TB was consistently associated with an increased risk of subsequent lung cancer (LC). The pooled estimate demonstrated a statistically significant positive association, despite moderate heterogeneity. Larger nationwide cohorts contributed greater statistical weight, while smaller studies showed wider variability. Case reports revealed heterogeneous temporal patterns, including long-latency scar-associated carcinoma and concurrent inflammatory–malignant presentations. Conclusions: Contemporary controlled evidence supports an association between prior tuberculosis and increased risk of subsequent lung malignancy. However, despite strong biological plausibility and the abundant literature on cancer-associated tuberculosis, modern longitudinal studies specifically evaluating tuberculosis as a preceding independent risk factor remain limited. The small number of eligible post-2020 investigations identified in this meta-analysis highlights a significant contemporary research gap and underlines the need for well-designed prospective studies to clarify causality and guide surveillance strategies in TB-exposed populations. Full article

The hybrid parallel operation of the grid-following (GFL) converter and the grid-forming (GFM) converter has become a typical scenario in distribution networks. The vastly different control philosophies and dynamics between the two give rise to complex small-signal stability issues, especially under weak grids. Traditional methods primarily rely on equivalent models or impedance-based approaches at fixed operating points, which struggle to reveal the system instability mechanisms when the capacity ratio between the two types of converters changes. This paper establishes a three-port dynamic average model for a grid-connected system with heterogeneous GFL-GFM converters. Using the participation factor analysis method, the system’s dominant modes are identified, and the key parameters influencing oscillations at different frequencies, as well as their formation processes, are revealed. Furthermore, a stability analysis method for variable capacity ratios is proposed. This method re-performs modal analysis based on the varying capacities of the GFM and GFL converters, revealing the dominant factors and influencing mechanisms of system instability during capacity transitions. Finally, a simulation model is built in PSCAD/EMTDC to verify the correctness of the proposed three-port model and the theoretical analysis results. Full article

Background: The pain experienced by people with fibromyalgia (FM) is thought to be the result of altered nociceptive processing, impaired descending inhibition and reduced tolerance to physical load. However, the relationship between the amount of exercise and pain reduction remains unclear. Methods: This study synthesized randomized controlled trials of exercise interventions for FM to quantify the combined analgesic effects of different types of exercise. A secondary aim was to standardize exposure using metabolic equivalent of task (MET)-based metrics and examine the association between cumulative intervention dose (MET·h) and analgesic response (Hedges’ g) across intervention arms. Following the PRISMA guidelines, a search was conducted in PubMed for randomized controlled trials published up to 31 December 2025. After screening and a full-text assessment, 15 trials were included. The protocols were converted into MET-defined intensity and weekly MET·min exposure, and the cumulative dose was calculated as the total MET·h accrued over the intervention period. Random-effects models were used to estimate the pooled effects within modality subgroups. Results: Across modalities, exercise was associated with reductions in pain, with effects typically falling within the small-to-moderate range. Larger improvements were observed in structured or supervised programs. The dose-response scatter plot showed wide variability across the dose range, with overlapping confidence intervals. An exploratory fourth-degree polynomial fit explained limited variance (R² = 0.1615) and did not indicate a monotonic dose-response pattern. This suggests that cumulative workload alone is a weak proxy for therapeutic response. Conclusions: Based on these findings, a pain-responsive algorithm combining weekly Visual Analogue Scale (VAS), ΔVAS and Talk Test thresholds was implemented as a preliminary online calculator to support the prescription of exercise tailored to symptoms. Full article

Three-phase LLC resonant converters are attractive for high-power applications due to their reduced output current ripple, improved thermal distribution, and inherent scalability. However, component tolerances in resonant tanks often cause phase current imbalance, leading to asymmetric conduction losses among the converter phases, output ripple, and uneven thermal stress. This paper proposes a simple online balancing algorithm that dynamically adjusts input voltage phase shifts to equalize RMS phase currents in real-time. The presented approach is capable of achieving a low unbalance factor even under severe mismatch conditions. The algorithm was validated on an 11 kW LLC prototype, achieving operation with an unbalance factor less than 2% over the full operating frequency range. Results demonstrate improved electrical symmetry and reduced thermal stress, confirming the practicality of the proposed strategy for high-power three-phase LLC converters. Full article