Search Results (1,698)

The authors of this article describe a study designed to support first-grade students’ social studies knowledge and literacy development through a teacher–researcher co-constructed and teacher implemented integrated unit within the context of a rural community. The goals of the study were to determine the extent to which a contextually relevant unit of study affected the development of students’ content knowledge of key terms from the domain of social studies and influenced students’ reading and social studies interest. The researchers used a combined multi-phase and convergent mixed methods design, implementing a matched pairs design for the quantitative, quasi-experimental component of the study. Results indicated that assignment to the treatment condition was a predictor of students’ post implementation vocabulary scores and social studies interest. In pairing these results with the qualitative analyses of students’ end-of-unit retellings, researchers found that vocabulary can be a powerful bridge to cultural and content knowledge when the focus of instruction and texts is on local and community knowledge, demonstrating that contextually relevant social studies–literacy integration is a promising practice for building content knowledge and interest in first grade classrooms. Directions for future research are discussed. Full article

Unmanned Aerial Vehicles (UAVs) are increasingly integral to construction site management, supporting monitoring, inspection, and data collection tasks. Effective UAV path planning is essential for maximizing operational efficiency, particularly in complex and dynamic construction environments. While previous BIM-based approaches have explored representation models such as space graphs, grid patterns, and voxel models, each has limitations. Space graphs, though common, rely on predefined spatial spaces, making them less suitable for projects still under construction. Voxel-based methods, considered well-suited for 3D indoor navigation, suffer from three key challenges: (1) a disconnect between the BIM and voxel models, limiting data integration; (2) the computational cost and time required for voxelization, hindering real-time application; and (3) inadequate support for 4D BIM integration during active construction phases. This research introduces a novel framework that bridges the BIM–voxel gap via an enriched voxel map, eliminates the need for repeated voxelization, and incorporates 4D BIM and additional model data such as defined workspaces and safety buffers around fragile components. The framework’s effectiveness is demonstrated through path planning simulations on BIM models from two real-world construction projects under varying scenarios. Results indicate that the enriched voxel map successfully creates a connection between BIM model and voxel model, while covering every timestamp of the project and element attributes during path planning without requiring additional voxel map creation. Full article

Precise online measurement of large structural components is urgently needed in modern manufacturing and intelligent construction, requiring a measurement range over 1 m, near-millimeter accuracy, second-level measurement speed, and adaptability to complex environments. In this paper, three mainstream measurement technologies, namely the image method, line laser scanning method, and structured light method, are comparatively analyzed. The structured light method exhibits remarkable comprehensive advantages in terms of accuracy and speed; however, it suffers from the issue of occlusion during contour measurement. To tackle this problem, multi-camera stitching is employed, wherein the accuracy of camera calibration plays a crucial role in determining the quality of point cloud stitching. Focusing on the cable tightening scenario of meter-diameter cables in cable-stayed bridges, this study develops a contour measurement system based on the collaboration of multiple structured light cameras. Measurement indicators are optimized through modeling analysis, system construction, and performance verification. During verification, four structured light scanners were adopted, and measurements were repeated 11 times for the test workpieces. Experimental results demonstrate that although the current measurement errors have not yet been stably controlled within the millimeter level, this research provides technical exploration and practical experience for high-precision measurement in the field of intelligent construction, thus laying a solid foundation for subsequent accuracy improvement. Full article

As a critical supporting component in geotechnical engineering structures such as bridges, tunnels, and highways, the anchorage quality of bolts directly impacts their structural safety. The ultrasonic guided wave method is a popular method for the non-destructive testing of anchorage quality. However, noise from complex field environments, modal mixing caused by anchoring interface reflections, and dispersion effects make it challenging to directly extract defect features from guided wave signals in the time or frequency domains. To address these challenges, this study proposes a solution based on the combination of the guided wave time–frequency spectrum and the gated attention residual network (GA-ResNet). The GA-ResNet introduces a gating mechanism to balance spatial attention and channel attention, and it is used for anchoring model type recognition. Experiments were conducted on four types of anchorage models, and the time–frequency spectrum was selected to be the input feature. The results demonstrate that the GA-ResNet can effectively predict the anchorage bolt defect type and prevent potential safety accidents. Full article

A long-standing challenge for the structural health monitoring (SHM) community is the masking effect of environmental variability, typically addressed by orthogonal projection (OP)-based data normalization to isolate the influence of environmental variability and enable structural anomaly detection. However, conventional OP techniques, such as principal component analysis, rely on clean and complete data, and their performance degrades in the presence of outliers or missing entries. To overcome this limitation, this paper proposes an integrated approach that combines OP with noisy low-rank matrix completion (NLRMC). The main advantage of NLRMC is its ability to couple low-rank and sparse decomposition with matrix completion, simultaneously handling data corruption and missingness to recover incomplete datasets and enable robust anomaly detection. By incorporating novelty-indicator extraction, a fully online, unsupervised anomaly-detection procedure is established. Validation on a vibration-based SHM dataset from the KW51 railway bridge confirms that the NLRMC-OP approach achieves reliable detection of operational state changes before and after retrofitting, even under both data corruption and missing scenarios. This study advances the usability of SHM data and facilitates efficient decision-making, while also highlighting the broader significance of leveraging the low-rank data structure in AI-enabled operation and maintenance of civil infra-structure. Full article

Background: Movement is crucial for human development, particularly during childhood. Fundamental movement skills (FMSs) are essential movement patterns that support physical, cognitive, and social development. Recent studies indicate an alarming worldwide decline in FMS acquisition, potentially impacting children’s long-term physical fitness and health. This scoping review explored FMSs, their relationship to motor competence and physical literacy, associations with physical activity and fitness, assessment methods, and effective interventions. Methods: A comprehensive literature review was conducted using the PubMed, Web of Science, and Cumulative Index to Nursing and Allied Health Literature databases. The search utilized key phrases related to FMSs, motor competence, and physical literacy. Initially, 2251 publications were identified. Results: After rigorous screening, 95 English-language literature reviews and meta-analyses focusing on FMSs in healthy children were selected for detailed analysis. The accepted publications were categorized into five thematic areas: FMSs and motor development (11 publications), conceptual terms in FMS context (8 publications), relationships between FMSs and other parameters (15 publications), FMS assessment tools (14 publications), and intervention effects on FMSs (47 publications). Conclusions: Effective FMS acquisition requires collaborative interventions involving teachers, parents, sports professionals, and healthcare providers. Future research should focus on developing standardized assessment tools, interpreting FMSs as part of physical literacy to understand their association with PA level and design efficient intervention strategies. Full article

The method addresses the challenges of non-steady conditions at an early age by combining wavelet filtering and empirical mode decomposition (EMD) to separate strain components arising from shrinkage, expansive agent compensation, temperature variations, construction disturbances, and live loads. The approach incorporates construction logs as external constraints to ensure accurate correspondence between signal features and physical events. Scientifically, this study addresses the fundamental problem of identifying and quantifying multi-source strain components under transient and non-steady construction conditions, which remains a major challenge in the field of structural monitoring. Field monitoring was conducted on typical cast-in-place concrete components: a full-width bridge deck in the negative moment region. The results show that both structural types exhibit a distinct shrinkage–recovery process at an early age but differ in amplitude distribution, recovery rate, and restraint characteristics. During the construction procedure stage, the cast-in-place segment in the negative moment region was sensitive to prestressing and adjacent segment construction. Under variable loads, the former showed higher live load sensitivity, while the latter exhibited more pronounced temperature-driven responses. Total strain decomposition revealed that temperature and dead load were the primary long-term components in the structure, with differing proportional contributions. Representative strain variations observed in the field ranged from 10 to 50 µε during early-age shrinkage–expansion cycles to 80–100 µε reductions during prestressing operations, quantitatively illustrating the evolution characteristics captured by the proposed method. This approach demonstrates the method’s capability to reveal transient stress mechanisms that conventional steady-state analyses cannot capture, providing a reliable basis for strain monitoring, disturbance identification, and performance evaluation during construction, as well as for long-term prediction and optimization of operation–maintenance strategies. Full article

Mild cognitive impairment (MCI), a transitional stage between normal aging and Alzheimer’s disease (AD), comprises three potential trajectories: reversion, stability, or progression. Accurate prediction of these trajectories is crucial for disease modeling and early intervention. We propose a novel analytical framework that integrates a healthy control–AD difference template (HAD) with a large-scale Granger causality algorithm based on long short-term memory networks (LSTM-lsGC) to construct effective connectivity (EC) networks. By applying principal component analysis for dimensionality reduction, modeling dynamic sequences with LSTM, and estimating EC matrices through Granger causality, the framework captures both symmetrical and asymmetrical connectivity, providing a refined characterization of the network alterations underlying MCI progression and reversion. Leveraging graph-theoretical features, our method achieved an MCI subtype classification accuracy of 84.92% (AUC = 0.84) across three subgroups and 90.86% when distinguishing rMCI from pMCI. Moreover, key brain regions, including the precentral gyrus, hippocampus, and cerebellum, were identified as being associated with MCI progression. Overall, by developing a symmetry-aware effective connectivity framework that simultaneously investigates both MCI progression and reversion, this study bridges a critical gap and offers a promising tool for early detection and dynamic disease characterization. Full article

The eco-toxicological impacts caused by organic pollutants in aquatic environments have emerged as a global concern in recent decades, resulting from the potential hazards they present to ecosystem integrity and human health. Decorating active components on mesoporous silica is considered a popular approach by which to obtain synergistic effects in persulfate activation for sustainable water decontamination. However, at present there has been no review focusing solely, specifically and comprehensively on this field. Therefore, this paper places an emphasis on the latest research progress on the synthesis and physicochemical properties of functionalized mesoporous silica materials as well as their catalytic performance. The preparation methods included co-condensation, impregnation, grinding–calcination, hydrothermal synthesis and chemical precipitation, and their synthesis parameters played a major role in the characterization of materials, thereby affecting pollutant elimination. Metal redox cycles, nonmetallic activation and confinement effects contributed to persulfate activation. Targeted pollutants were degraded via radical pathways, non-radical pathways, or a combination of the two. The effects and causes of operational conditions (catalyst and persulfate dosage, initial pollutant concentration, temperature, initial pH, co-existing anions, and natural organic matter) varied across the degradation systems, and they were categorized and summarized in detail. Furthermore, functionalized mesoporous silica presented excellent reusability, stability and applicability in practical application. Finally, current potential directions for further research and sustainable development in this field were also prospected. This critical analysis aims to fuel the evolution of functionalized mesoporous silica catalyst-driven persulfate system application in water treatment and to bridge prevailing knowledge gaps. Full article

In this work, a radar imagery-based signal processing technique to eliminate dynamic clutter interference in Structural Health Monitoring (SHM) is proposed. This can be considered an application of a joint communication and sensing telecommunication infrastructure, leveraging a base-station as ground-based radar. The dynamic clutter is considered to be a fast moving road user, such as car, truck, or moped. The proposed technique is suitable in case of a dynamic clutter, such that its Doppler contribute alias and falls over the 0 Hz component. In those cases, a standard low-pass filter is not a viable option. Indeed, an excessively shallow low-pass filter preserves the dynamic clutter contribution, while an excessively narrow low-pass filter deletes the displacement information and also preserves the dynamic clutter. The proposed approach leverages the Time Domain Backprojection (TDBP), a well-known technique to produce radar imagery, to transfer the dynamic clutter from the data domain to an image plane, where the dynamic clutter is maximally compressed. Consequently, the dynamic clutter can be more effectively suppressed than in the range-Doppler domain. The dynamic clutter cancellation is performed by coherent subtraction. Throughout this work, a numerical simulation is conducted. The simulation results show consistency with the ground truth. A further validation is performed using real-world data acquired in the C-band by Huawei Technologies. Corner reflectors are placed on an infrastructure, in particular a bridge, to perform the measurements. Here, two case studies are proposed: a bus and a truck. The validation shows consistency with the ground truth, providing a degree of improvement within respect to the corrupted displacement on the mean error and its variance. As a by-product of the algorithm, there is the capability to produce high-resolution imagery of moving targets. Full article

This research explores the potential introduction of marine waste-derived biological fillers within bio-epoxy matrices to mitigate the environmental impact of traditional materials, like fiberglass, in boat construction. However, this raises concerns about biofouling and degradation, issues that have not been extensively investigated in composites, especially over a time frame representative of issues that could arise during service. Although protective solutions like biocides and specific coatings exist, degradation remains challenging when attempting to use eco-friendly natural fillers. This study specifically integrates various biological fillers, namely ceramics (mussel, oyster, clam powder) or ligno-cellulosic (i.e., Posidonia oceanica fibers) into epoxy for use in some boat components (bench seats for the bridge deck), aiming to evaluate the biofouling process under extreme (or decommissioning) conditions. In itself, epoxy does represent an ideal enclosing matrix for biomass waste, which ideally needs to be introduced in significant amounts. The development of biofouling in the specific context of Kotor’s Bay, Montenegro, for a duration of six months, and relevant composite degradation were examined. In particular, three situations were reproduced by positioning the samples in a harbor environment: (i) on the bottom of the sea (2 m. depth), (ii) immersed just below the surface (0.5 m. depth), and (iii) on the splashing surface (pier). The concerns identified appear generally limited in the case of the envisaged application, despite some significant wear effect in the case of the samples containing Posidonia. However, this study also offers information and caveats in terms of more ambitious prospective applications (e.g., the boat hull structure). Full article

This study investigates how university students perceive the ecosystem services provided by gardens, utilizing Q methodology to categorize subjective viewpoints and analyze distinct perception types. Thirty-two students majoring in forest and landscape architecture at Wonkwang University (Iksan, Republic of Korea) participated, sorting 30 Q-statements each for provisioning, regulating, cultural, and supporting services. Principal component analysis identified three factors for provisioning and regulating services, and two factors for cultural and supporting services. The findings reveal that students’ perceptions are primarily based on generalized, idealized expectations, while their understanding of specific practices, such as food production, distribution, and community economic integration, remains insufficient. This indicates that their perceptions are more conceptual than practical, reflecting themes such as eco-friendly resource sharing, environmental regulation, nature experience, biodiversity enhancement, and sustainability. These results suggest the need for enhanced educational efforts to improve students’ understanding of the role of ecosystem services in urban contexts. The study highlights the importance of bridging the gap between theoretical knowledge and practical recognition to foster more comprehensive perceptions, ultimately informing future garden design, management strategies, and environmental education programs. Full article

Tall-pier, long-span continuous rigid-frame bridges are prone to wind-induced vibration due to their large spans and pier heights; during cantilever erection, the maximum double-cantilever stage has reduced stiffness and buffeting becomes more evident. Accordingly, a time-domain framework driven by three-component aerodynamic coefficients and their angle-of-attack derivatives is adopted. Code-based target spectra are used to synthesize multi-point fluctuating wind time histories via harmonic superposition, followed by statistical and spectral consistency checks. Buffeting forces are then computed under the quasi-steady assumption, mapped to finite-element nodes, and integrated in time to obtain global responses (displacement and acceleration). In parallel, static six-component wind tunnel tests provide mean force and moment coefficients and their derivatives for comparison. The results indicate that the three-component time-domain approach captures the buffeting features dominated by vertical and torsional responses. When pronounced along-span sectional variation and high angle-of-attack sensitivity are present, errors associated with the strip assumption increase, whereas the force–moment coupling revealed by the six-component data helps explain discrepancies between simulation and tests. These response patterns and error characteristics delineate the applicability and limits of the three-component time-domain evaluation for variable-depth continuous rigid-frame bridges, offering a reference for wind resistance assessment and construction-stage checking of similar bridges. Full article

Citrus peels, long used in traditional food preservation, are rich in bioactive compounds with potential antioxidant and antimicrobial properties. However, a systematic comparison of the efficacy of different citrus varieties and the underlying mechanisms in meat preservation remains limited. This study investigated the chemical composition of peels from four citrus varieties (Citrus reticulata, CR; C. sinensis, CS; C. bigarradia, CB; and C. macrocarpa, CM) and their efficacy in preserving beef quality during refrigerated storage. GC-MS analysis revealed limonene as the predominant volatile component (59.6~77.1%), with CR peel exhibiting the highest content (77.1%). CR extract also demonstrated superior antioxidant activity (DPPH: 60.8%; ABTS: 66.0%) and antimicrobial effects against five common meat microbial species. Beef samples treated with CR peel extract significantly (p < 0.05) reduced lipid oxidation (TBARS: 2.88 vs. 4.83 mg MDA/kg in control) and protein degradation (TVB-N: 270 vs. 371 mg/kg). Microstructural integrity was better maintained, as evidenced by lower surface hydrophobicity, higher sulfhydryl content, and reduced carbonyl formation. Furthermore, CR treatment suppressed microbial growth (TBC and TAC reduced by ~30%) and the accumulation of spoilage-related biogenic amines, particularly putrescine (12~18.8 vs. 27.4 mg/kg). Correlation analysis identified limonene content as strongly correlated with antioxidant and antimicrobial activities. This work validates the scientific basis of using citrus peel, particularly CR, as a natural preservative, effectively bridging traditional culinary practice with modern food science by elucidating its multi-target role in extending the shelf life and enhancing the safety of beef. Full article

With the growing application of digital technologies in construction, reinforcement detailing and cutting are becoming increasingly refined. However, existing cutting methods struggle to meet the dual requirements of low waste and high computational efficiency when facing diverse rebar types, multiple splice points, and complex constraints. This paper proposes a hybrid optimization algorithm for large-scale rebar cutting that achieves efficient joint optimization of splice positions and cutting schemes. Numerical simulations verify the performance of the proposed algorithm under normal and uniform length distributions, with comparisons against traditional methods. Results show that the proposed method maintains the waste ratio below 1% for large-scale numerical datasets while achieving much higher computational efficiency than heuristic algorithms with good stability and scalability. Two engineering examples further validate this approach. In column longitudinal reinforcement, the waste ratio in each story was kept below 1%, and in precast bridge segmental beams, the method flexibly incorporated customized raw rebar lengths, reducing the waste ratio to as low as 0.4%. The proposed method effectively balances material utilization and cutting efficiency, offering a practical solution for intelligent rebar cutting across a wide range of components and construction scenarios. Full article