Search Results (82)

Assessing whether existing lattice towers can survive extreme wind when they are located on ridgelines or at saddle points requires three questions to be answered simultaneously: how the local wind field is modified by the surrounding topography, how the structural geometry recorded in legacy computer-aided design (CAD) drawings can be recovered accurately, and which member fails first and by what mechanism. This paper couples a Physics-Informed Neural Network (PINN) wind solver, jointly constrained by mass and momentum conservation, with a graph-theory-based Drawing Exchange Format (DXF) parser and a closed-loop vulnerability screening module, so that all three questions are answered in a single automated pass. The PINN reconstructs the three-dimensional steady-state wind field over irregular topography in approximately 0.12 s, holding the root-mean-square (RMS) velocity divergence below 2.1 × 10⁻³ (more than two orders of magnitude lower than that of linear interpolation) while recovering the pressure-gradient-driven acceleration that mass-consistent variational solvers cannot represent. On the CAD side, k-dimensional tree (KD-Tree) spatial indexing combined with breadth-first search (BFS) connected-component analysis resolves the pseudo-disconnections, spurious intersections, and multi-level nested block references that are common in production DXF files, achieving 100% node-merging accuracy across fifteen tower drawings. A unified Vulnerability Index (VI) that combines strength, member stability, and plate buckling into a single scalar, updated through Sherman–Morrison rank-one perturbation at a millisecond cost, closes the diagnose–strengthen–verify loop without re-solving the full stiffness system. Applied to a 220 kV line struck by Super Typhoon Meranti, the pipeline identified seven at-risk members that code-based checking had missed, a result consistent with the recorded field damage, and completed the full assessment in 34.4 s, over three orders of magnitude faster than conventional practice. Full article

Cementitious composites inevitably develop cracks during service, leading to the ingress of harmful agents and durability deterioration. Permeable crystalline agents (PCAs) have attracted extensive attention due to their combined potential for reinforcement, impermeability, and self-healing. However, the existing studies still lack a unified analysis of the controversies regarding the modification mechanisms of different PCAs, and their mechanical properties, durability, and self-healing capacity have not yet been systematically integrated. To clarify the aforementioned divergences and identify future research directions, this paper adopts a narrative literature review approach, systematically searching relevant publications from the past fifteen years in the CNKI and WOS databases. It comprehensively summarizes the compositional characteristics, action mechanisms of PCAs, and their influence on the evolution of strength, durability, and self-healing performance of cementitious composites. The results indicate that the precipitation–crystallization theory and the complexation–precipitation synergy theory each have distinct emphases in explaining the mechanism, and their combined interpretation can more fully reveal the working essence of PCAs. The performance of PCA-modified cementitious composites is influenced by factors such as PCA composition, PCA dosage, and a curing environment; therefore, engineering parameters should be reasonably determined based on specific working conditions. Finally, recommendations for future research directions on PCA-modified cementitious composites are proposed. Full article

The cloud model provides a unified mathematical framework for representing both randomness and fuzziness simultaneously, offering an effective mathematical tool for modeling complex systems. This paper focuses on the emergent phenomenon of spontaneous synchronous flashing in fireflies and employs Gaussian cloud model theory to develop an initialization framework. Uncertainty is quantified using three core numerical characteristics of the cloud model—expectation, entropy, and hyperentropy—while a Gaussian potential function is adopted to characterize how interaction strength varies with spatial distance. A MATLAB-based simulation platform is developed to reproduce the emergent transition of fireflies from disordered flashing to synchronous behavior across different spatial domains. Our results demonstrate that group synchronization efficiency is strongly governed by the initial spatial configuration of individuals. Introducing driving nodes (special agents) can accelerate synchronization, but increasing their quantity yields diminishing marginal returns; the optimal strategy is a single special agent placed at the domain center. Collective emergence depends more strongly on the topological structure of inter-individual interactions than on the number of driving nodes. These findings confirm that interaction topology dominates synchronization performance over driving-node quantity, providing a theoretical basis for guiding unmanned swarm coordination with minimal control nodes. Full article

Purpose: The purpose of this paper is to provide an integrative review of Positive Psychology in contemporary organizational contexts, examining how psychological resources such as Psychological Capital, Emotional Intelligence, Mindfulness, Psychological Safety, Self-Determination Theory, and Positive Leadership contribute to employee well-being, flourishing, and organizational effectiveness. Design/Methodology/Approach: This study adopts a narrative integrative literature review approach, synthesizing recent theoretical and empirical research in Positive Organizational Psychology, Organizational Behavior, and Human Resource Management. The review integrates foundational theories with contemporary empirical findings published in high-impact academic journals to develop a comprehensive conceptual framework. Findings: The findings indicate that Positive Psychological constructs are consistently associated with higher levels of employee engagement, job satisfaction, performance, resilience, and flourishing, while reducing burnout, stress, and turnover intentions. Psychological Capital emerges as a key malleable resource, while Mindfulness and Emotional Intelligence enhance self-regulation and interpersonal effectiveness. Originality: The paper integrates multiple streams of Positive Psychology into a unified conceptual model, combining individual-level psychological resources with motivational and organizational-contextual factors. Research limitations/implications: As a narrative review, the study does not include primary empirical data or statistical testing. Future research should empirically validate the proposed integrative framework using longitudinal and cross-cultural designs. Practical implications: Organizations can enhance employee well-being and performance by implementing Psychological Capital Interventions, mindfulness-based programs, strengths-based development, and psychologically safe leadership practices. Social implications: The findings highlight the broader societal value of fostering psychologically healthy workplaces that promote sustainable employment, mental health, and human flourishing. Full article

The final stage of urban logistics does not end at the building entrance but continues within complex, vertically structured indoor environments, where conventional ground-based delivery systems face limitations in efficiency, flexibility, and scalability. This study introduces the concept of last-meter delivery, defined as unmanned aerial vehicle (UAV)-enabled transport from the building envelope to the recipient within global navigation satellite system (GNSS)-denied, building-regulated indoor space, and systematically reviews the literature from two traditionally separate domains: indoor-UAV operation in GNSS-denied spaces, and outdoor-UAV-based logistics. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 297 studies are synthesized through a two-stream thematic synthesis. The review makes three contributions. First, a unified analytical framework is developed across four dimensions (spatial mobility, logistical capability, social acceptance, and operational coordination) through which the two bodies of literature are shown to be largely complementary, with the gaps in one stream coinciding with the strengths of the other. Second, indoor aerial delivery is found to be subject to a distinct set of operational constraints, including micro-scale navigation accuracy, strict geometric safety envelopes, close human–UAV interaction, and privacy sensitivity, implying that indoor transport-UAVs cannot be realized through simple miniaturization of outdoor platforms but require precision-oriented, human-centric, and building-aware design. Third, the four dimensions are translated into a building-management-oriented indicator framework covering spatial compliance, handover standardization, building information modeling (BIM) integration, occupant consent, and liability allocation, reframing last-meter requirements in terms that are actionable for building planners and facility managers. By framing these challenges within the last-meter perspective, this review identifies the gap between current last-mile theories and emerging in-building aerial logistics and provides a structured foundation for future research. Full article

Background: Hypoplastic left heart syndrome (HLHS) is defined as “a spectrum of congenital cardiovascular malformations with normally aligned great arteries without a common atrioventricular junction, characterized by underdevelopment of the left heart with significant hypoplasia of the left ventricle including atresia, stenosis, or hypoplasia of the aortic or mitral valve, or both valves, and hypoplasia of the ascending aorta and aortic arch”. Without treatment, HLHS is usually lethal in the neonate. Many hypotheses have been advanced to explain the etiology of HLHS; however, no single theory appears to fully explain the phenotypic variability seen in HLHS. Furthermore, many of these theories offer no explanations regarding the precipitating events which lead to the development of HLHS. Objective: This review considers and critically evaluates the strengths and weaknesses of the leading theories proposed to explain the pathogenesis of HLHS—including hemodynamic disturbances, primary myocardial structural defects, valvar malformations, and genetic or epigenetic alterations that may provoke developmental and anatomic abnormalities. After presenting each model, we propose a novel, comprehensive, and data-driven framework which may assist researchers in developing models for the pathogenesis of the various subtypes of HLHS. Methods: Key findings from human fetal imaging, histopathology, genetic studies, and animal models were considered, as well as the hypothetical contribution of each in observed HLHS phenotypes. The rationales for these findings as causal factors initiating individual HLHS patterns, as well as how they might contribute to HLHS in general, were critically analyzed. Results: The flow theory is strongly supported by animal models and in utero interventions that demonstrate the impact of altered hemodynamics on cardiac morphogenesis. However, the flow theory fails to identify initial causes of disturbed flow or related histological features of HLHS like endocardial fibroelastosis. The myocardial and valve-first models suggest an important role in developmental defects, but do not necessarily have a strong experimental basis that provides explanations for how they mediate HLHS. Genetic studies in patients with HLHS have identified several candidate causal mutations. However, such genetic causes of HLHS exhibit incomplete phenotypic penetrance and clinical impact. A multifactorial framework attempts to integrate these diverse mechanisms and may provide the most coherent explanation that can accommodate the heterogeneity and variable presentation of HLHS. Such a framework may identify multiple forces that drive disease but does not provide useful pathways for future research about HLHS. Conclusions: No single hypothesis has fully explained how HLHS is initiated, progresses, and presents with the clinical conditions that are encountered by cardiac surgeons and cardiologists. The most current models suggest that the spectrum of HLHS reflects acomplex interaction between genetic susceptibility, flow-dependent cardiac remodeling, and environmental factors in utero. A multifactorial model integrates these diverse mechanisms and may provide the most coherent explanation for the various phenotypic variations in HLHS. Based on our analysis of the most current data and the strengths and weaknesses of the current theoretical frameworks, we propose a novel research strategy aimed at identifying specific cardiac progenitor cell populations whose dysregulation may represent a unifying explanation for the etiology of the various phenotypes of HLHS. Based on the arguments made throughout this manuscript that evaluate the various genetic, structural, and hemodynamic models of initiation of disease, we believe that the significant phenotypic variability across the spectrum of HLHS (i.e., the different anatomic subtypes for “classic” HLHS) most likely reflects different underlying etiologies and mechanisms. At the very least, it is very likely that the timing of the insult is critical in determining anatomic subtype. Based on the published data and the arguments within this manuscript, it seems naive to think that there is a single unifying mechanism explain all forms of HLHLS. Full article

Accurate modeling of irradiance scintillation is important for evaluating underwater wireless optical communication (UWOC) systems operating in oceanic turbulence. Existing studies have mainly focused on weak oceanic turbulence conditions, while irradiance scintillation modeling under arbitrary oceanic turbulence strength remains insufficiently developed. In this work, the Gaussian beam is adopted as the representative model of practical laser beams, whereas the plane-wave and spherical-wave cases are introduced as limiting cases to support the derivation and theoretical completeness of the Gaussian-beam formulation. A unified theoretical framework is developed based on the general oceanic turbulence optical power spectrum (OTOPS). Building upon previously reported weak-turbulence results, the scintillation index (SI) under saturated strong turbulence is first derived using asymptotic theory. Then, within the extended Rytov approximation, an effective-scale treatment is introduced to characterize the contributions of large- and small-scale eddies to irradiance fluctuations. By connecting the weak- and saturated-turbulence limits through asymptotic matching, a closed-form SI expression valid over a wide range of oceanic turbulence strengths is obtained. Numerical results show that the proposed model agrees well with the corresponding boundary cases and reproduces the characteristic “bump” behavior of oceanic turbulence, while highlighting the influence of ocean-specific cutoff spatial frequencies on the predicted scintillation peaks. These results provide a physically consistent analytical framework for UWOC channel modeling and performance evaluation under arbitrary oceanic turbulence strength. Full article

The time-varying mesh stiffness excitation of helical gears impacts the vibration state of the rotor–bearing systems, while the existence of mechanical dynamic eccentricity makes the rotor–bearing dynamics equation a system of parametric excitation. To address this situation, the time-varying mesh stiffness of the helical gear is substituted into the coupled bending–torsion–axial dynamic equation of the rotor–bearing system. By considering dynamic eccentricity, the rotor’s vibration displacement response is calculated. The unified strength theory is introduced to compute the complex stress state. The study’s results indicate that time-varying stiffness significantly influences the system’s vibration characteristics, with the equivalent stress values exceeding those under twin-shear stress. This finding demonstrates the advantage of using the unified strength theory under high-load conditions, providing an essential reference for optimizing the dynamic performance of high-speed helical gear transmission systems. Full article

Membrane structure sports stadiums, characterized by high strength, high formability, and distinctive architectural expression, represent an emerging direction in contemporary sports architecture. This study investigates how perceived relative advantage, green value, perceived gain, and social influence affect consumers’ intentions to experience and consume in membrane structure sports stadiums, with particular attention to the mediating role of perceived usefulness. Drawing on the Unified Theory of Acceptance and Use of Technology (UTAUT) as the theoretical framework, questionnaire data were collected and empirically tested using structural equation modeling. The results indicate that perceived relative advantage, green value, perceived gain, and social influence have significant positive effects on experience and consumption intention, and that perceived usefulness plays a significant mediating role in these relationships. The study clarifies the mechanisms through which these factors shape intention in the context of membrane structure sports stadiums and offers theoretical and empirical support for their promotion and development. Full article

Standard compatibility-based truss models, including the Disturbed Stress Field Model (DSFM), often underestimate the shear strength and deformation capacity of reinforced-concrete (RC) beam-column joints. This study investigates the origin of this bias through a systematic inverse identification framework and derives joint-core constitutive relationships tailored to the highly confined, nonuniform stress states of joints. Inverse analyses show that improving confinement effectiveness alone leads to unrealistic parameter saturation and cannot reproduce the measured energy absorption, indicating that conventional compression-softening formulations remain excessively punitive for joint cores. When confinement activation and softening are identified simultaneously, a clear mechanism shift emerges: unlike panel-based theories that link softening to tensile-cracking measures (principal strain ratio), joint softening is overwhelmingly governed by the principal compressive strain, consistent with crushing-dominated damage accumulation. Based on these trends, unified power-law expressions are proposed for both passive confinement activation and damage-induced softening as functions of principal compressive strain only, adhering to a parsimonious formulation without auxiliary variables such as concrete strength or reinforcement ratio ($R^2\approx 0.89$). The model is validated on an independent database of 113 specimens, including high-strength concrete and exterior joints, eliminating the systematic conservatism of the standard DSFM and improving the mean experimental-to-predicted strength ratio from 0.85 to 1.01 while reducing the coefficient of variation from 34.5% to 13%. The proposed formulation supports more reliable joint shear backbone predictions for seismic assessment of RC frame buildings. Full article

The mechanical behavior of loess under varying moisture conditions plays a critical role in the stability of slopes and foundations in loess regions. Owing to its high porosity and metastable structure, loess is particularly sensitive to moisture-induced strength degradation. Although geogrid reinforcement has been widely adopted to improve soil stability, the combined influence of moisture condition, reinforcement characteristics, and confinement on the shear behavior of loess remains insufficiently understood. In this study, consolidated undrained (CU) triaxial tests were conducted on partially saturated loess reinforced with glass fiber geogrids (GFGs) and basalt fiber geogrids (BFGs) under different moisture contents (13–17%) and confining pressures (100–300 kPa). The effects of geogrid type, reinforcement configuration, and confinement on shear strength and deformation behavior were systematically examined. The results indicate that geogrid reinforcement significantly enhances the shear strength, stiffness, and ductility of loess, particularly under low to moderate confining pressures. Increasing the number of reinforcement layers resulted in peak strength improvements of up to approximately 25% and promoted a transition from brittle to ductile behavior. Distinct reinforcement responses were observed: GFG exhibited higher initial stiffness and more rapid mobilization, whereas BFG demonstrated progressive tensile mobilization and superior residual strength. Furthermore, a modified Unified Twin-Shear Strength Theory (UTSST) incorporating a strain-dependent reinforcement mobilization coefficient was proposed, which provided an empirical representation of the observed strength evolution with good agreement with the experimental results (R² > 0.96). Full article

The post-genomic era has transformed medical genetics, raising renewed debate over the role of medical cytogenetics in clinical practice. High-throughput sequencing and chromosomal microarray technologies now dominate cancer diagnostics, prenatal testing, and rare disease evaluation by enabling rapid detection of gene-level variation, often leading to the perception that cytogenetics is obsolete. However, this view overlooks the unique and complementary strengths of cytogenetic analysis. Although the relationship between cytogenetics and current NGS technologies can be compared to that between forests and trees versus leaves—both of which are necessary for clinical diagnosis—cytogenetic methods uniquely enable direct in situ visualization of chromosomes, allowing detection of large-scale structural and numerical genome alterations at the level of individual cells and cell populations. These system-level features that are frequently invisible or difficult to interpret using sequencing-based approaches alone yet are critical in disease contexts where genome architecture itself carries biological and clinical significance beyond individual genes. This article, therefore, advances a new perspective based on Genome Architecture Theory: that karyotype-level information organizes gene-level function and that many previous gene-centric genetic concepts require reexamination within a unified framework of clinical genomics. Rather than being replaced, cytogenetics is increasingly integrated with sequencing within a unified framework of clinical genomics that combines high-resolution molecular detail with system-level insight into genome organization. Reassessing the role of cytogenetics, therefore, has important implications for medical education, diagnostic strategy, and healthcare policy, as cytogenetics provides the appropriate platform for understanding system-level inheritance through karyotype coding and for advancing molecular medicine from a genome systems perspective. Full article

To enhance the assessment accuracy of tunnel face instability risks of active collapse during shield tunneling, this study establishes a novel unified analytical framework that couples the effects of unsaturated transient seepage induced by excavation drainage with soil stratification and heterogeneity. Grounded in unsaturated effective stress theory, the framework explicitly incorporates matric suction into the Mohr–Coulomb failure criterion via suction stress and apparent cohesion. By employing a horizontal two-layer nonhomogeneous soil model and solving the one-dimensional vertical Richards’ equation, an analytical solution for the face drainage boundary is derived to quantify the spatiotemporal evolution of suction stress and apparent cohesion. Subsequently, the critical support pressure is evaluated using the upper bound theorem of limit analysis, incorporating a horizontal layer-discretized rotational failure mechanism and the power balance equation. The validity of the proposed framework is confirmed through comparative analyses. Parametric studies reveal that in the upper hard and lower soft strata, the critical support pressure decreases and converges over time, indicating that unsaturated transient seepage exerts a significant influence in the short term that stabilizes over the long term. Additionally, sand–silt stratum exhibits lower overall stability and higher sensitivity to groundwater levels and temporal factors compared to silt–clay stratum. Conversely, silt–clay stratum displays a non-monotonic evolution with increasing cover-to-diameter ratios ($C/D$), reaching a minimum critical support pressure at approximately $C/D=1.1$. Regarding heterogeneity, the internal friction angle of the lower layer exerts dominant control over the critical support pressure compared to seepage velocity, while the influence of other strength parameters remains secondary. These findings provide a theoretical basis for the time-dependent design of tunnel face support pressure under excavation drainage conditions. Full article

The increasing penetration of renewable energy leads to a continuous reduction in system inertia, for which conventional synchronization criteria based solely on frequency consistency can no longer accurately capture the coupled dynamics of frequency and voltage during transients. To address this issue, this paper employs the concept of complex frequency and develops an analysis framework that integrates theory, indices, and simulation for assessing synchronization stability in low-inertia power systems. Firstly, the basic concepts and mathematical formulation of complex frequency and complex frequency synchronization are introduced. Then, dynamic criteria for local and global complex synchronization are established, upon which a complex inertia index is proposed. This index unifies the supporting role of traditional frequency inertia and the voltage support capability associated with voltage inertia, enabling the quantitative evaluation of the strength of coordinated frequency–voltage support and disturbance rejection within a region. Finally, transient simulations on a modified WSCC nine-bus system are carried out to validate the proposed method. The results show that the method can clearly reveal the synchronization relationships between subnetworks and the overall system, providing a useful theoretical reference for stability analysis and control strategy design in low-inertia power systems. Full article

This systematic integrative review examines methodological frameworks used to evaluate educational technologies in biomedical higher education. We synthesize five complementary approaches frequently reported in the literature: the Technology Acceptance Model (TAM), the Unified Theory of Acceptance and Use of Technology (UTAUT), the System Usability Scale (SUS), Technology Readiness Levels (TRL), and the ARCS motivational model. Each framework addresses distinct but interrelated dimensions of evaluation, including technology acceptance and intention to use, perceived usability and user experience, technological maturity and implementation risk, and learner motivation. Drawing on representative studies in e-learning platforms, virtual and extended reality environments, and clinical simulation, we discuss the strengths, limitations, and common pitfalls of applying these models in isolation. Based on this synthesis, we propose a pragmatic, multi-phase evaluation workflow that aligns usability, acceptance, motivation, and technological maturity across different stages of educational technology development and adoption. Finally, we outline exploratory future perspectives on how existing evaluation models might need to evolve to address emerging AI-driven, immersive, and haptic technologies in biomedical education. This abstract was prepared in accordance with PRISMA 2020 for Abstracts, ensuring structured reporting and transparency. Full article