Search Results (2,370)

Background and objective: During adolescence, physical fitness attributes are a key factor positively influencing not only physical health, but also cognitive, psychological and social development. The objective was to derive data-driven physical fitness profiles and to characterize their sex-specific structure in Chilean adolescents using unsupervised machine learning and an explainable artificial intelligence (AI) framework. Methods: This cross-sectional study included a nationally representative sample of 25,912 Chilean schoolchildren (14,184 boys and 11,728 girls) aged 13 to 17 years. Six unsupervised clustering algorithms were applied separately by sex, each configured to partition participants into three clusters representing low, medium, and high physical performance levels. Results: K-means achieved the highest composite internal validity score for both sexes (boys: 0.959, Calinski–Harabasz 5757.7, Davies–Bouldin 1.203; girls: 0.976, Calinski–Harabasz 4156.1, Davies–Bouldin 1.349), and the partition was highly stable across 500 age-stratified bootstrap resamples (adjusted Rand index 0.973 in boys and 0.967 in girls). A Random-Forest surrogate reproduced the cluster labels with high fidelity (macro-averaged F1 0.984 in both sexes; Cohen’s κ 0.973 in boys and 0.975 in girls). Conclusions: Unsupervised machine learning with explainable AI provides a robust, transparent, sex-specific framework for stratifying adolescent fitness; cardiorespiratory capacity and abdominal endurance are the components that most consistently distinguish the profiles, while lower-limb power and upper-body endurance differentiate the higher performance tiers. Full article

Safe human-to-humanoid motion imitation is crucial for shared environments, where direct motion retargeting may induce self-collision or human–humanoid collision due to embodiment mismatch, kinematic limits, perception uncertainty, and human proximity. This paper presents an online vision-aided safe human-to-humanoid motion imitation framework that integrates skeleton-based upper-body pose estimation, joint-space retargeting, and capsule-based Control Barrier Function Quadratic Program (CBF-QP) safety filtering. Human skeletal observations are mapped to a reduced eight-degree-of-freedom (8-DoF) humanoid upper-body command, while the CBF-QP layer computes a safety-corrected target that minimally modifies the nominal imitation command subject to robot self-collision and human–humanoid collision constraints. The framework is evaluated via simulation and hardware experiments under representative self-collision and human–humanoid interaction episodes, complemented by a comparative benchmark against velocity damping and potential field baselines. Furthermore, this work introduces an evaluation protocol combining geometric safety, command deviation, and local-link similarity metrics to systematically characterize the safety–imitation trade-off governed by CBF parameters. The results demonstrate that, within the tested moderate-speed regime, the proposed framework substantially reduces geometric collision violations while balancing imitation fidelity with online computational feasibility, thereby providing a viable foundation for safe human-guided humanoid motion deployment. Full article

Background: Virtual reality (VR) is increasingly being explored as a tool for upper limb (UL) assessment in adults with neurological disorders. This review synthesizes the available evidence on VR-based UL assessments by analyzing their psychometric properties and potential role in clinical and research settings. Methods: This systematic review followed the Guideline for reporting systematic reviews of outcome measurement instruments (PRISMA-COSMIN) and was prospectively registered in PROSPERO. Data extraction was independently performed by two reviewers, with disagreements resolved by consensus or a third reviewer. Psychometric evidence was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology, including risk of bias assessment, evaluation and synthesis of measurement properties, and evidence grading according to GRADE. Additionally, the clinical application context of each VR assessment was examined, and a strengths, weaknesses, opportunities and threats analysis was conducted to explore factors affecting implementation and future development in neurorehabilitation. Results: Twenty VR-based UL assessments were identified. VR-Box and Blocks Test represented the largest body of evidence and was the only assessment implemented across all immersion levels, with promising findings in both stroke and Parkinson’s disease populations (Grade B recommendation). Immersive Action Research Arm Test demonstrated the strongest psychometric profile among the stroke sample (Grade B recommendation). Additionally, the Virtual Occupational Therapy Assistant and SaeboVR^® incorporated the most ecologically valid tasks, reflecting activities closer to daily life performance. Test–retest reliability and construct validity were the most frequently evaluated measurement properties. Conclusions: VR-based assessments represent promising tools for UL assessment. However, despite most systems receiving a Grade B recommendation, the supporting evidence remained low or very low certainty due to methodological shortcomings and incomplete psychometric evaluation. Therefore, more rigorous and methodologically robust research is needed to strengthen the evidence supporting their implementation in clinical practice as a complementary tool for UL assessment. Full article

Background and Clinical Significance: Foreign body aspiration is an important cause of morbidity and mortality in children younger than three years of age. Although laryngeal foreign bodies are uncommon, they may be life-threatening and are frequently misdiagnosed because of their variable clinical presentation. Eggshell aspiration is exceptionally rare, with only a few cases reported in the literature. We report a case of delayed diagnosis of a glottic eggshell foreign body in a toddler presenting with persistent upper airway symptoms. Case Presentation: A 16-month-old previously healthy girl was referred to our hospital for evaluation of persistent hoarseness and barking cough following a witnessed choking episode while eating boiled egg. The choking episode had occurred 15 days before presentation during an episode of viral upper respiratory tract infection. Initial symptoms were attributed to laryngitis and persisted despite medical treatment. Flexible laryngoscopy revealed a foreign body impacted at the glottic level, while neck radiography demonstrated a radiopaque calcified lesion corresponding to the foreign body. Microlaryngoscopy under deep sedation was performed, and an approximately 10-mm eggshell fragment was successfully removed. A small amount of granulation tissue was observed at the posterior commissure, corresponding to the site of foreign body impaction. The postoperative course was uneventful, and repeat endoscopic examination on postoperative day three demonstrated satisfactory laryngeal healing with regression of the granulation tissue. Conclusions: This case highlights the importance of considering a retained laryngeal foreign body in young children with persistent hoarseness or barking cough following a choking episode, even in the presence of concomitant respiratory infection. Early endoscopic evaluation is essential to avoid diagnostic delay and facilitate prompt treatment. In addition, this report emphasizes the importance of food choking prevention and caregiver education in children younger than three years of age. Full article

Classical hydrodynamic lubrication studies of journal bearings routinely invoke two simplifying assumptions: the axially rigid–straight journal assumption and the structure–lubrication decoupling assumption. For marine water-lubricated stern bearings, propeller overhung loading induces non-negligible shaft deflection across the bearing length, and the multi-support shafting makes the stern-bearing reaction force impossible to determine from rigid-body statics alone. Both assumptions must be removed within a single analysis framework. This study develops a coupled lubrication–rotor framework that combines a two-dimensional steady Reynolds solver with groove masking, a Winkler elastic liner, and a ROSS-based Timoshenko rotor finite element model through bidirectional reaction-force–tilt feedback. A normalised axial load distribution indicator $I_w\left(z\right)$, defined from the axial film-pressure profile, is introduced as a scalar boundary quantity linking the elastohydrodynamic lubrication solution to downstream wear evolution models. Condition decomposition and open-loop tilt sweeps show that the coupled-convergence tilt reduces $h_{min}$ by 65.7%, raises $p_{max}$ by 84.5%, and shifts the axial reaction-force distribution and $I_w\left(z\right)$ peak toward the stern end. Axial non-uniformity intensifies monotonically with the increase in tilt angle, and beyond a threshold tilt, the HD/EHL solver no longer converges for a hard phenolic liner, establishing the applicability upper bound of the framework. Full article

Plyometric training is proposed as a method for improving neuromuscular performance in climbing; however, its specific effects on upper-body explosive power and rate of force development (RFD) in male boulderers, ranging from trained to highly trained, remain unclear. This preliminary exploratory trial examined the effects of a 10-week plyometric training program on selected laboratory-based neuromuscular performance outcomes. Eighteen male climbers were assigned to: intervention group (n = 9, 29.7 ± 4.5 yr) or a control group (n = 9, 31.3 ± 5.6 yr). Finger flexor strength and RFD (20-mm grip, 0–200 ms, 20–80%), isometric pull-up strength and RFD (load cell), upper-body power (plyometric push-up, Power Slap), and lower-body power (CMJ) were assessed. The intervention comprised two plyometric sessions/week for 10 weeks. Significant differences were observed in pull-ups (Δ difference = +3.89 repetitions; 95% CI: 0.30, 7.48; p = 0.036; η²p = 0.248), push-up power (Δ difference = +174.25 W; 95% CI: 5.05, 343.46; p = 0.044; η²p = 0.230), isometric pull-up RFD 0–200 ms (Δ difference = +107.85 kg/s; 95% CI: 27.54, 188.16; p = 0.012; η²p = 0.336), and the 20–80% range (Δ difference = +261.78 kg/s; 95% CI: 23.09, 500.47; p = 0.034; η²p = 0.253). No clear between-group differences were observed for finger flexor strength, finger RFD, maximum isometric pull-up strength, Power Slap, or CMJ. Given the exploratory design, small sample size, and low reliability of RFD-derived variables, these findings should be interpreted cautiously as preliminary evidence of movement-specific neuromuscular performance improvements. Full article

The reproductive contribution of river-resident (freshwater) Japanese eels (Anguilla japonica) remains poorly understood, particularly following recent paradigm shifts that emphasise the predominance of ocean-resident “sea eels.” To elucidate the riverine life history and maturation strategies of freshwater residents, we investigated the age structure, morphological traits, and gonadal development of 100 river-resident Japanese eels captured over a three-year period (2007–2009: n = 33, 40, and 27, respectively) in the middle reaches (25–50 km upstream) of the Oi River, Shizuoka Prefecture, Japan. Age determination using sagittal otoliths revealed a broad age distribution from 4 to 15 years. Among the female population (n = 85), highly significant positive correlations were observed between age and growth parameters (Total Length, R² = 0.771; Body Weight, R² = 0.709; p < 0.001). Highly mature silver eels with markedly elevated gonadosomatic indices (GSI) were captured at the uppermost sampling site, immediately downstream of an impassable dam barrier. This spatial concentration of mature females suggests an energetic and temporal life-history strategy in which river-resident eels initiate precocious maturation in the upper reaches to compensate for the prolonged downstream migration to the river mouth. Notably, the calculated female growth rate of approximately 3.6 cm/year was significantly slower than that reported for coastal and estuarine conspecifics in Japan, indicating a distinct slow-growth history unique to river-resident cohorts. Although historical baselines exhibit significant annual variation (ANOVA, p < 0.05), they provide an invaluable benchmark for river-resident cohorts prior to the severe depletion of wild stocks. Our findings underscore that large freshwater-resident females may serve as vital somatic and reproductive reserves, and provide key recommendations for rigorous habitat conservation within river systems to sustain the species. Full article

Background/Objectives: The rapid growth of the companion animal industry has increased demand for professional pet grooming services; however, occupational health risks among pet groomers remain underexplored. This cross-sectional study investigated the prevalence of musculoskeletal disorders (MSDs), occupational burnout, and associated occupational and ergonomic factors and their interrelationships among pet grooming professionals. Methods: A total of 180 pet grooming professionals were recruited through geographically stratified convenience sampling across northern, central, and southern Taiwan. Data were collected using structured questionnaires assessing demographics, workload, ergonomic equipment, and working postures. MSD symptoms were evaluated using the Nordic Musculoskeletal Questionnaire, and occupational burnout was assessed using the Taiwan Ministry of Labor Burnout Assessment Scale. Descriptive statistics, one-way analysis of variance (ANOVA), Pearson’s correlation analysis, and multiple linear regression analysis were performed to identify factors associated with MSD severity and occupational burnout. Results: MSDs were highly prevalent, with 95% of participants reporting symptoms in at least one body region. The most affected regions were the right shoulder (71.7%), neck (70.6%), upper back (65.6%), and lower back (65.6%). Significant associated ergonomic factors included excessive bathing tub depth (≥46 cm), non-adjustable grooming tables, prolonged trunk flexion, and horse-stance postures. Higher workload intensity, including frequent bathing tasks and handling aggressive or large animals, was significantly associated with greater MSD severity (p < 0.05). Moderate-to-severe personal- and work-related burnout were identified in 43.3% and 37.2% of participants, respectively. MSD severity was positively correlated with personal-related burnout (r = 0.491, p < 0.001) and work-related burnout (r = 0.428, p < 0.001). Multiple linear regression analysis results indicated the MSD score was a significant predictor of both personal- and work-related burnout (p < 0.001). Conclusions: Pet grooming professionals experience a substantial burden of MSDs and occupational burnout associated with ergonomic strain and physically demanding work. Non-neutral postures and inadequately designed equipment were significantly associated with greater MSD severity. The close association between MSDs and burnout underscores the interrelationship between physical and psychological occupational health. Ergonomic workplace modifications and targeted occupational health interventions are necessary to improve worker well-being and industry sustainability. Full article

Background and Clinical Significance: Necrotizing fasciitis (NF) is a fulminant, life-threatening polymicrobial infection of the soft tissues, characterized by the progressive and widespread necrosis of the subcutaneous tissues and fascial planes. Although the cervical region is an infrequent site of involvement, cervical necrotizing fasciitis (CNF) is distinguished by its rapid anatomical spread, severe systemic complications, and significant mortality rates. Case Presentation: This report details the fatal clinical course of a 37-year-old immunocompetent male with no relevant active comorbidities. The patient initially presented with insidious, non-specific symptoms clinically interpreted as an uncomplicated upper respiratory tract infection/acute pharyngitis, including pharyngodynia, hoarseness, fever, lateral cervical lymphadenopathy, and catarrhal secretion. Within a brief period, his clinical status underwent rapid deterioration, with progressive cervical swelling, dysphonia, swallowing impairment, dyspnoea, shock, and subsequent multi-organ dysfunction syndrome. A total-body computed tomography scan revealed lateral cervical subcutaneous emphysema, a small pneumomediastinum, bilateral pleural effusion and bilateral pulmonary parenchymal consolidations. Conclusions: A comprehensive forensic examination revealed swelling and brownish-green discoloration of the right cervical region, palpable crepitus, and extensive necrosis of the cervical soft tissues, with involvement of the deep fascial layers and regional musculature. Histological examination confirmed massive cervical soft tissue necrosis associated with inflammatory infiltration and air bubbles. Multifocal acute pneumonia was also documented. This case underscores the importance of a meticulous examination of the cervical region during autopsy in suspected infection-related fatalities. Clinically, it highlights the diagnostic challenges posed by the deceptive and paucisymptomatic onset of CNF. Full article

Background and Objectives: The prediction of difficult laryngoscopic view remains an important component of preoperative airway assessment. Conventional bedside tests are widely used, but their diagnostic performance may be limited by subjectivity and interobserver variability. Focused upper airway ultrasonography may provide objective anatomical information and complement standard clinical evaluation. This study aimed to evaluate the diagnostic accuracy of focused upper airway ultrasonographic and conventional anthropometric measurements for predicting difficult laryngoscopic view in adult patients scheduled for tracheal intubation. Materials and Methods: This single-center, prospective, observational study included 212 adult patients with American Society of Anesthesiologists physical status I–III who were scheduled for elective surgery under general anesthesia requiring tracheal intubation. Preoperative airway assessment included the Modified Mallampati classification, upper lip bite test, mouth opening, thyromental distance, and sternomental distance. Focused ultrasonographic measurements included hyoid–skin distance and epiglottis–skin distance. Difficult laryngoscopic view was defined as a Cormack–Lehane grade III–IV view recorded during the initial direct laryngoscopic assessment. Diagnostic performance was evaluated using receiver operating characteristic curve analysis, and independent predictors were assessed using multivariable logistic regression. Results: Difficult laryngoscopic view was identified in 44 of 212 patients (20.8%). Patients with difficult laryngoscopic view had significantly higher body weight and body mass index, smaller mouth opening, and greater hyoid–skin distance. Hyoid–skin distance was significantly greater in patients with difficult laryngoscopic view than in those without difficult laryngoscopic view (12.00 ± 2.79 mm vs. 10.33 ± 3.16 mm; p = 0.002). Mouth opening was significantly smaller in patients with difficult laryngoscopic view (4.39 ± 0.72 cm vs. 4.74 ± 0.99 cm; p = 0.030). Epiglottis–skin distance did not differ significantly between groups. In receiver operating characteristic analysis, hyoid–skin distance showed an area under the curve of 0.682, with a cut-off value of ≥12.05 mm, sensitivity of 47.73%, and specificity of 83.33%. In multivariable logistic regression analysis, body mass index and hyoid–skin distance were independently associated with difficult laryngoscopic view, whereas greater mouth opening had a protective effect. The combined multivariable model showed an area under the curve of 0.734; however, at a probability cut-off value of 0.5, its sensitivity was low at 15.9%, despite high specificity of 97.0%. Conclusions: Focused upper airway ultrasonography may provide complementary objective information when used together with conventional preoperative airway assessment. Hyoid–skin distance was independently associated with difficult laryngoscopic view and demonstrated relatively high specificity; however, its discriminatory performance was modest and its sensitivity was limited. Therefore, hyoid–skin distance and the combined model should not be interpreted as standalone screening tools for excluding difficult laryngoscopic view. Their main clinical value may be as adjunctive parameters that support risk stratification and advance airway management planning in selected patients. Full article

AI-driven growth is pushing data-center electricity demand from 415 TWh (2024) toward 945 TWh by 2030. Demand-response research has matured on operational levers but treats the physical envelope as largely exogenous, leaving construction-phase decisions that bound achievable flexibility unmodeled. This article integrates three previously separate bodies of literature (data-center demand response, grid-interactive efficient buildings, and stochastic optimal control under irreversibility) into a single framework that prices construction-phase flexibility as a portfolio of real options, pairing elicitation-derived (FAHP) weights with simulation-derived (Sobol) variance indices. None of the individual techniques is new; the contribution is their synthesis and the finding that architectural and site decisions carry the dominant financial leverage in the model, whereas a literature-grounded synthetic-persona prior (twenty-five LLM-simulated personas) prioritizes mechanical-electrical systems; a divergence we frame as a screening diagnostic between an LLM prior and the model. The Flex-by-Design Readiness Index (FDRI) is a nineteen-dimension taxonomy across architectural, MEP, and site-urban layers, weighted by Fuzzy AHP. The FDRI–ROV model formalizes the decision as stochastic optimal control under irreversibility. Calibrated to PJM, ERCOT, and CAISO (2024–2026) for a 100 MW plant at N = 10,000 paths over thirty years, it yields +$79 M net option value at Full FDRI for PJM (additive upper bound; substitution-corrected ≈ +$41 M, 1.7× CapEx; 2.4× CapEx PJM, 2.1× ERCOT, 2.8× CAISO); on both the additive (2.4–2.8×) and corrected (1.7×) bases the pre-registered H2 threshold of Vtotal/Ctotal ≥ 3× is not met. Sobol decomposition places architectural and site layers at ST ≈ 0.56 each versus MEP at 0.15, exposing waste-heat-export and regulatory-avoided-cost dimensions as under-recognized leverage. Out-of-sample validation against four hyperscale projects yields 11% MAPE, reported as an n = 4, single-period proof of concept.A pro-rata extrapolation across all ~43 GW of incremental U.S. capacity gives a nominal ~$34 billion through 2035, but this applies the single most optimistic scenario uniformly; applying the substitution-corrected per-plant value with competition, policy, and adoption decay multipliers, the defensible 2035 opportunity is ≈$3–$18 billion (central ≈$7 billion), with $34 billion retained only as an undecayed ceiling. Full article

Background: Obesity hypoventilation syndrome (OHS) is a life-threatening condition often underdiagnosed in patients with obstructive sleep apnea (OSA). While bariatric surgery induces weight loss, it does not immediately resolve upper airway obstruction. We investigated the feasibility and clinical predictors of a novel transdisciplinary approach—Combined Airway and Bariatric Surgery (CABS)—in treating OHS. Methods: This prospective observational cohort study (December 2022–November 2024) recruited 36 adults with obesity (body mass index [BMI] ≥ 30 kg/m²) and OSA (apnea–hypopnea index [AHI] ≥ 5 events/h). OHS was diagnosed by daytime hypercapnia (PaCO₂ ≥ 45 mmHg) after excluding other causes of hypoventilation. Participants received CABS or positive airway pressure therapy via shared decision-making. Primary outcomes included changes in AHI, BMI, PaCO₂, and Epworth Sleepiness Scale (ESS). Results: Nine of 36 individuals (25%) had OHS. Multivariate logistic regression identified BMI and ESS as significant predictors. Receiver operating characteristic curve analysis showed high OHS prediction with BMI ≥ 35.5 kg/m² (area under the curve [AUC] = 0.85), ESS ≥ 12 (AUC = 0.72), and a novel OHS prediction score > 20 (AUC = 0.94). Among 6 OHS patients who underwent CABS, one-year follow-up showed significant improvements: AHI decreased from 98.1 to 26.8 events/h, BMI from 40.1 to 29.1 kg/m², and PaCO₂ from 50.2 to 37.9 mmHg (all p < 0.05). Conclusions: OHS was present in one-quarter of individuals with obesity and OSA in this cohort. CABS was feasible and associated with encouraging improvements in sleep-disordered breathing, ventilatory status, and weight among selected patients. These preliminary findings support further evaluation of this transdisciplinary strategy in larger, comparative studies. Full article

Background and Objectives: Exoskeletons may be useful in preventing musculoskeletal disorders. This study aimed to evaluate the biomechanical and subjective effects of a passive shoulder exoskeleton during overhead assembly work in a real-world automotive manufacturing environment. Materials and Methods: Sixteen workers performing overhead assembly tasks participated in this study. Muscle activity, joint angles, and joint reaction forces were compared between the No Exo and Exo conditions during overhead work. Muscle activity was measured using surface electromyography (EMG), upper-body kinematics were captured using inertial measurement units (IMUs), and shoulder joint torques and reaction forces were estimated using the AnyBody musculoskeletal modeling system. Additionally, user satisfaction was assessed through a questionnaire. Results: Comparison of biomechanical outcomes between the No Exo and Exo conditions showed that the Exo condition significantly reduced anterior and lateral deltoid activities by approximately 15.2% and 11.1%, respectively, and reduced glenohumeral joint reaction force by 115.24 N (all p < 0.05). Participants also reported lower physical workload (p < 0.001). Conclusions: The study results suggest that wearing an exoskeleton during overhead work may reduce shoulder muscle loading and improve biomechanical indicators associated with shoulder loading. Full article

Background and Objectives: Obesity is a major global public health problem associated with numerous complications. Likewise, the use of antiplatelet and anticoagulant agents has increased with population aging and the growing burden of cardiovascular diseases. This study aimed to evaluate the effects of obesity and antiplatelet/anticoagulant therapy on the clinical presentation, bleeding severity, and short-term clinical outcomes of patients with gastrointestinal bleeding. Materials and Methods: A prospective cohort study was conducted in consecutive patients admitted with upper or lower gastrointestinal bleeding to a tertiary referral center between January 2024 and January 2025. Patients were categorized according to body mass index (BMI) and antithrombotic therapy status. Clinical characteristics, bleeding severity scores, treatment requirements, and short-term clinical outcomes were compared. Multivariable multinomial logistic regression analysis was performed to identify independent associations. Results: A total of 177 patients were included. Obese and overweight patients were significantly older than normal-weight patients (p = 0.001), whereas no significant differences were observed among BMI groups regarding the Glasgow–Blatchford score, pre-endoscopic Rockall score, transfusion requirements, endoscopic intervention, or short-term clinical outcomes. Patients receiving antiplatelet or anticoagulant therapy had significantly higher Charlson Comorbidity Index, bleeding severity scores, and packed red blood cell transfusion requirements than those receiving no antithrombotic therapy (all p < 0.01). However, after multivariable adjustment, these associations did not remain independent, and advanced age remained the only independent factor common to both treatment groups. Conclusions: Obesity was not independently associated with bleeding severity or short-term clinical outcomes in patients with gastrointestinal bleeding. Although antiplatelet and anticoagulant therapy were associated with more severe bleeding-related clinical findings, these associations were not independent after multivariable adjustment. Full article

Accurate and rapid prediction of waterflood front propagation and volumetric sweep efficiency remains challenging in ultra-low-permeability reservoirs because of strong heterogeneity, threshold pressure gradients, reservoir anisotropy, complex well-pattern geometry, and layer-dependent flow interference. In this study, an improved 3D streamtube model was developed for waterflood-front tracking and volumetric sweep evaluation in ultra-low-permeability reservoirs. The model incorporates experimentally constrained threshold pressure gradients, anisotropic coordinate transformation, dynamic streamtube flow-rate allocation, Buckley–Leverett-based non-piston displacement, interlayer interference correction, and irregular well-pattern adaptability. A unified calculation framework was established for both injector–producer and injector–fracture streamtube units, enabling 3D integration of layer-specific swept areas into volumetric sweep efficiency. The proposed model was validated against a commercial numerical simulator using a representative well group from Block A of the Changqing Oilfield. The predicted streamtube architecture and sweep-efficiency evolution agree well with numerical simulation results, with an average relative error of approximately 3.1%, while reducing the computational time from 1043 s to 1.42 s for a 30-year simulation. Sensitivity analysis demonstrates that threshold pressure gradient, well spacing, and inter-well connectivity are the dominant controls on sweep efficiency, whereas well-pattern type, interlayer heterogeneity, and reservoir anisotropy exert secondary but non-negligible effects. Field application further reveals a strongly layer-dependent waterflood behavior: the upper sand body preferentially propagates eastward, whereas the lower sand body advances mainly southward, producing a vertically asynchronous and laterally misaligned sweep pattern. These results show that the proposed model provides an efficient and physically interpretable tool for rapid waterflood-front prediction, refined waterflood optimization, and targeted production enhancement in heterogeneous ultra-low-permeability oil reservoirs. Full article