Search Results (2,470)

A working-state model is proposed for the MnOx–Na₂WO₄/SiO₂ catalyst in oxidative coupling of methane (OCM), where a Na₂WO₄-rich surface environment forms an adaptive interphase that buffers the effective interfacial oxygen chemical potential and stabilizes cooperative MnO_x/Na–WO_x/Mn–O–W motifs. A thermodynamic-kinetic scheme is developed that relates (1) reaction-induced surface enrichment (structural stabilization), (2) oxygen spillover (damping of local oxygen gradients), and (3) Mn ↔ W redox exchange as an electron-oxygen buffer channel. Ex situ XPS/EDS/EPR data indicate a dynamically stratified near-surface region with chemically heterogeneous environments of Mn, W, and O. The W 4f region remains dominated by the W⁶⁺ contribution in the presence of a minor reduced component after OCM. In oxygen-deficient mixtures (CH₄/O₂ > 4), interfacial reconstruction becomes more pronounced: Mn-centered Mars–van Krevelen chemistry determines CH₄ activation and oxygen exchange, while the Na₂WO₄-rich phase ensures fast ion/oxygen transport. Observation of the EPR signal from W⁵⁺ ions in the tungstate matrix indicates the existence of reduced W intermediates at low oxygen potential. Optimization of C₂ selectivity and stability is suggested to require maintaining the catalyst within the selective window of effective interfacial μO by adjusting CH₂/O₂ and contact time, as well as controlling the architecture of the Na–W–O/MnO_x interfacial region. Full article

Inflorescence degeneration in Areca catechu L. is characterized by growth arrest, tissue shrinkage and browning, ultimately compromising functional inflorescence formation and yield stability. To investigate its developmental window and regulatory basis, inflorescences from different leaf positions at the full-bloom stage were analyzed using anatomical observation, morphological measurements, carbohydrate and hormone assays, and RNA-seq-based transcriptomic analysis with qRT-PCR validation. Inflorescence degeneration was mainly concentrated in axillary inflorescences at the third and fourth leaf positions (BY3 and BY4). Compared with adjacent normal inflorescences, degenerated inflorescences showed reduced sucrose, starch and trehalose contents, increased ABA, JA and MeJA levels, and decreased cZR levels. Transcriptomic analysis revealed clear separation between degenerated and normal inflorescences, and differentially expressed genes were enriched in starch and sucrose metabolism, plant hormone signal transduction and transcriptional regulation. Co-expression network analysis identified modules associated with the degeneration window and key physiological traits, highlighting six candidate hub genes: AcAHP2, AcTIFY4B, AcTPS9-2, AcHXK2, AcWRKY3 and AcMPK1. These findings suggest that inflorescence degeneration is closely associated with carbon metabolic imbalance, hormone network remodeling and co-expression network reprogramming within a specific developmental window, providing a basis for future mechanistic studies and control strategies. Full article

Recurrent meteorological droughts, projected to intensify under climate change, affect the cross-border Lima River Basin shared between Portugal and Spain, highlighting the need for robust early warning systems to support proactive water management. Within the EU-funded RISC_PLUS project—aimed at strengthening resilience to hydro-climatic risks in the cross-border Minho–Lima River Basins—this study develops a regionalised forecasting framework to evaluate meteorological drought forecast skill using precipitation forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) Seasonal Forecasting System 5 (SEAS5) for the Portuguese section of the Lima River Basin. A precipitation-only 12-month Standardized Precipitation Index (SPI12) is employed to isolate the contribution of seasonal precipitation forecasts. SPI12 is computed from hybrid 12-month accumulations combining observed monthly precipitation (October 1979 to February 2025) and SEAS5 forecasts (October 2018 to February 2025). Four hybrid configurations (1 to 6 months lead time) are evaluated: 11 obs + 1 fcst, 10 obs + 2 fcsts, 9 obs + 3 fcsts, and 6 obs + 6 fcsts. Forecast performance is assessed from October 2018 to February 2025. Deterministic SPI12 forecasts and categorical drought classifications are evaluated using regression-based metrics (e.g., Pearson correlation and RMSE) and contingency-table metrics (e.g., FAR and F1-score), across SEAS5 ensemble members, percentiles, and spread-based indicators. The 11 obs + 1 fcst configuration, particularly when using the Dry Spread (SpD; Q10 + Q25 percentiles) and the Q75 percentile, exhibits the highest skill, achieving a Pearson correlation coefficient of $r=0.97$ and an RMSE of approximately 0.17, alongside near-perfect categorical performance (POD = 1.00; FAR = 0.00), although these scores are partly conditioned by the shared observed accumulation window. Conversely, longer lead-time configurations exhibit degraded performance, with the 6 obs + 6 fcsts configuration showing weak or negative skill relative to climatology, indicating that 6-month lead forecasts should be interpreted with caution. These results demonstrate that SEAS5 precipitation forecasts can provide skilful drought predictions at lead times of several months in the Lima River Basin within the SPI12 framework. The proposed blending methodology provides a transparent benchmark and a technical basis for the early-warning system being developed under the RISC_PLUS project to support drought risk management in the Minho–Lima region and complement data-driven drought forecasting approaches. Full article

This study presents a decentralized shared actor–critic framework for cooperative multi-robot coverage in continuous two-dimensional simulation. The method combines permutation-invariant local observations, continuous differential-drive control, and reward shaping based on stepwise Hungarian assignment distances, collision penalties, and time efficiency. Homogeneous teams of four, five, and six agents are evaluated in an obstacle-free environment using five independent training seeds. In the final training window, the full reward configuration achieved full-team success rates of 98.2 ± 2.9% for four agents, 85.1 ± 18.0% for five agents, and 96.3 ± 2.0% for six agents, with mean landmark coverage above 96% in all cases. The lower mean in the five-agent setting was associated with higher seed-level variability dominated by one low-success seed. Reward ablations without assignment shaping or collision penalties remained viable, and seed-level tests did not show a statistically significant final-window advantage of the full reward configuration. The full configuration reached the 80% rolling-success threshold earlier in median terms, with the clearest seed-level support in the four-agent setting. Within-environment comparison showed higher full-team success than MADDPG and MAPPO under the matched training horizon and final-window protocol. Deterministic arena-size transfer from $15\times 15$ to $30\times 30$ showed decreasing full-team success as arena size increased, while partial landmark coverage remained higher than strict full-team completion. The results support the method for small homogeneous teams in the tested obstacle-free simulation, while larger teams, external obstacles, aerial-robot dynamics, formal safety guarantees, and hardware deployment remain future work. Full article

Background/Objectives: Chronic home oxygen therapy—long-term oxygen therapy (LTOT)—improves survival and quality of life in chronic respiratory failure when used ≥15 h/day, but adherence is frequently suboptimal and specific patient-reported outcome measures (PROMs) are scarce. To develop, validate and apply a specific PROM for patients on LTOT. Methods: A prospective observational cohort study was conducted at San Juan de Alicante University Hospital (April 2024–December 2025) following a four-stage process: conceptual framework definition and expert workshop, content validation and item reduction, cognitive interviews with pilot reliability testing (n = 25), and field application to 120 consecutive chronic LTOT users. The LTOT-PROM was designed to capture the patient-perceived impact attributable to LTOT during the previous 4 weeks. Internal consistency was assessed with Cronbach’s α and test–retest reproducibility with the intraclass correlation coefficient (ICC). Results: The final instrument comprises 15 scored items in two dimensions—Daily Activity (9 items) and Adverse Effects (6 items)—plus one ambulatory-only mobility item excluded from the total score. Cronbach’s α was 0.814 (95% CI 0.681–0.906) for Daily Activity, 0.743 (95% CI 0.548–0.872) for Adverse Effects and 0.808 (95% CI 0.677–0.902) for the total scale; total ICC(A,1) was 0.890 (95% CI 0.767–0.950). Among the 120 patients (62 men, 58 women; mean age 78 ± 13 years; mean therapy duration 40 ± 32 months), 68% reported reduced effort for daily activities, 66% reported a reduction in dyspnoea and 67% reported improved self-confidence; 49% reported morning airway dryness and 7% abandoned the equipment due to nasal dryness or rhinitis. Conclusions: The LTOT-PROM is a brief, reliable and reproducible oxygen-specific instrument for assessing the recent patient-perceived impact of LTOT in routine clinical practice. Further studies should evaluate structural validity, external validity and the relationship between LTOT-PROM scores and objective adherence measures. The construct was predefined as the patient-perceived impact attributable to LTOT during a standardised 4-week recall window, and cognitive interviews confirmed that respondents interpreted the items as experienced benefit/burden during that period rather than as week-to-week symptom change. Full article

Prenatal alcohol exposure (PAE) is recognized as a major public health concern due to its profound and lasting effects on the central nervous system (CNS) and its ability to induce fetal alcohol spectrum disorders (FASD), which encompass a wide range of cognitive, behavioural, and neuropsychiatric disorders that persist throughout life. Experimental and clinical studies have identified several mechanisms underlying ethanol impairing brain development, including apoptosis, oxidative stress, disruption of morphogen and growth factor signalling pathways, impaired neuronal proliferation and migration, neurotransmitter systems’ dysfunction, glial cells damage associated with deficient myelination, vascular and blood–brain barrier (BBB) alterations, and lasting epigenetic reprogramming. However, to date no widely accepted integrative framework explaining how these impairments underline the heterogeneous phenotype observed in FASD is available. The present brings together developmental neurobiology and computational neuroscience to conceptualize PAE as a disorder of emerging neural and functional architecture. Here, we summarize the pharmacokinetics of ethanol in pregnancy, critical windows of vulnerability, and the classical pathways of alcohol teratogenesis affecting neuronal survival, migration, synaptogenesis, myelination, and gene regulation. We have also reviewed MRI, diffusion imaging, and EEG/MEG evidence showing altered brain volumes, white matter microstructure, functional connectivity, and network organization in individuals with PAE. Finally, we propose a systems-level model that conceptualizes PAE as a disorder of emerging neuro-computational architecture, in which ethanol-induced cellular and molecular perturbations collectively alter the building blocks and self-organization rules of brain network assembly. Full article

Background/Objectives: Air pollution is associated with many adverse health consequences, including deteriorated kidney function. The aim of the research was to determine the association of medium-term exposure to air pollutants and hospitalizations due to acute kidney injury (AKI). Methods: The retrospective population-based study was conducted on the EP-PARTICLES cohort between 2011 and 2020 (80,000,000 person-years). We estimated municipality-specific associations between air pollution and AKI admissions using generalized additive models with Poisson regression. Results are reported as risk ratio in AKI admissions (RR) with corresponding 95% confidence intervals (95% CI). Results: During the 10-year study period, 47,467 AKI cases were reported (median age 77 years, IQR 68–84; 51.2% women). Mean concentrations of pollutants were 21.4 µg/m³ (SD 5.2) for particulate matter with a diameter of 2.5 μm or less (PM_2.5), 7.5 µg/m³ (1.8) for nitrogen dioxide (NO₂), and 1.8 ng/m³ (0.8) for benzo[a]pyrene (BaP). In mid-term exposure analyses (lag 0–30), each 10 µg/m³ increase in PM_2.5, PM₁₀, NO₂ and CO, and each 1 µg/m³ increase in BaP, was associated with higher AKI risk, with the strongest effect observed for NO₂ (RR 1.066, 95% CI 1.033–1.099). No association was found for SO₂. Subgroup analyses showed consistent directions of association across sex and age groups, with NO₂ remaining the most detrimental pollutant. Although statistical significance varied between pollutants, no significant effect modification by sex or age was observed (p > 0.05). Conclusions: Mid-term exposure to ambient air pollution is associated with an increased risk of AKI-related hospitalizations, with NO₂ showing the strongest effects. These findings identify mid-term exposure as a relevant temporal window and support the role of air pollution as a modifiable risk factor for AKI. Full article

Background: Type 2 inflammatory diseases are among the most common chronic inflammatory conditions in childhood and represent a growing global health burden. Increasing evidence suggests that early-life nutritional exposures may influence immune programming and allergic disease development. This Position Paper aims to summarize the current evidence regarding the immunomodulatory role of polyunsaturated fatty acids (PUFAs), particularly omega-3 long-chain fatty acids, in the prevention of allergic diseases during early life. Methods: A scoping literature review and consensus process were conducted to map biological mechanisms and clinical evidence linking omega-3 PUFAs with allergic disease prevention. This document analyzed experimental, observational, and randomized controlled studies evaluating maternal prenatal/lactational omega-3 exposure. The clinical evidence was qualitatively appraised using study-design-specific Joanna Briggs Institute (JBI) Critical Appraisal Tools. Particular attention was given to immune modulation, inflammatory pathways, epithelial barrier function, gut microbiota interactions, and the ferroptosis–immune–metabolic axis. Results: Omega-3 PUFAs, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), exert immunomodulatory and anti-inflammatory effects through multiple mechanisms, including specialized pro-resolving mediator production, regulation of T-helper cell responses, cytokine modulation, maintenance of epithelial barrier integrity, and microbiota interaction. Emerging evidence also supports their involvement in oxidative stress and ferroptosis regulation. Current clinical evidence, particularly from higher-quality prenatal randomized trials and evidence syntheses, suggests that adequate maternal omega-3 intake during pregnancy and lactation may reduce the risk of respiratory allergic outcomes, especially wheezing and asthma, in selected offspring. Conclusions: Adequate omega-3 PUFA intake, such as 2 g/die, during critical windows of immune maturation may represent a valuable strategy for the primary prevention of allergic diseases. Current evidence most strongly supports supplementation during pregnancy and lactation, particularly in populations with low dietary omega-3 intake or increased allergic risk. Omega-3 supplementation should be considered within a broader multifactorial preventive approach aimed at promoting immune tolerance and reducing the future burden of allergic diseases. Full article

Social media studies often rely on one platform while drawing conclusions about online publics more generally. This study tests that inferential move through an event-centered comparison of El Niño discourse across X/Twitter, YouTube, Facebook, Reddit, TikTok, and LinkedIn. The observation window ran from 9 May through 17 May 2026, several days before and after the May 14 El Niño Watch issued by the National Oceanic and Atmospheric Administration (NOAA), which reported an 82 percent probability of El Niño emerging during May to July 2026 and a 96 percent probability of continuation through the 2026 to 2027 Northern Hemisphere winter. The corpus contains 8145 items classified as highly or moderately related to El Niño after platform-specific collection and common annotation. X/Twitter supplies 7075 items, YouTube 864, Facebook 66, Reddit 59, TikTok 50, and LinkedIn 31. Texts were annotated with a shared structured schema covering relevance, sentiment, emotion, topic, stance, likely misinformation, personal experience, humor, calls to action, language, engagement, and length. The results show that platform choice changes the empirical object. X/Twitter appears multilingual, fast-moving, and weather-heavy. YouTube is more negative, humorous, and personally experiential. Facebook is long-form and media/news oriented, with the highest model-flagged likely misinformation rate. Reddit is concentrated around weather concern. TikTok is short, playful, and personal. LinkedIn is small, professional, and mostly informational. These differences caution against generalizing from one platform to social media as a whole unless a study explicitly defines its scope, accounts for platform and genre differences, and recognizes that visible discourse may include organizational, algorithmically amplified, automated, or otherwise inauthentic activity alongside genuine human expression. Full article

Background: Odontogenic keratocysts are developmental cysts of the jaws that often remain asymptomatic until they reach considerable size and are most frequently located in the mandibular angle and ramus regions. Due to their high recurrence potential, the optimal treatment approach remains controversial. The aim of this study was to evaluate treatment modalities associated with lower recurrence rates in odontogenic keratocysts. Material and Methods: Patients diagnosed with odontogenic keratocyst between 2000 and 2024 at the Department of Oral and Maxillofacial Surgery, Gazi University, were retrospectively evaluated. Associations between gender, age, lesion localization, histological subtype, treatment modality, and recurrence were analyzed. Statistical analyses were performed using SPSS for Windows (version 27). Results: A total of 291 cases were included, with an overall recurrence rate of 16.2%. The highest recurrence rate was observed in patients treated with enucleation (19.2%), whereas a lower recurrence rate was found in cases treated with marsupialization (5%). No recurrence was observed in patients who underwent resection. A statistically significant association was found between treatment modality and recurrence (p = 0.014). Conclusions: Treatment selection for odontogenic keratocysts should be carefully planned. In the present study, marsupialization was associated with a lower recurrence rate than enucleation in selected cases. However, because of the retrospective design and non-randomized treatment allocation, these findings should be interpreted with caution and should not be considered evidence of a causal relationship. Long-term clinical and radiological follow-up remains essential because of the potential for late recurrence. Full article

Photobiomodulation (PBM) is a non-invasive therapeutic strategy that uses red and near-infrared (NIR) light in the 590–950 nm range to modulate the cellular and molecular pathways involved in retinal homeostasis. At the molecular level, PBM acts primarily through photon absorption by cytochrome c oxidase (CcO, complex IV of the mitochondrial electron transport chain), whose four metal centres—two copper (CuA and CuB) and two heme groups (heme a and heme a₃)—absorb light across approximately 600–1000 nm. Photon capture promotes photodissociation of inhibitory nitric oxide (NO) from the binuclear CuB–heme a₃ centre, accelerates electron transfer, restores the proton-motive force and increases ATP synthesis. These primary events trigger a coordinated molecular programme that includes (i) transient mitochondrial reactive oxygen species (ROS) bursts that activate the Nrf2/Keap1/ARE axis and upregulate phase II antioxidant enzymes (HO-1, NQO1, GCLC, SOD2, catalase, GPx); (ii) calcium- and cAMP-dependent secondary signalling that converges on PI3K/Akt, MAPK/ERK, AMPK and mTOR pathways; (iii) suppression of NF-κB-driven cytokine production (TNF-α, IL-1β, IL-6) and of NLRP3 inflammasome activation; (iv) downregulation of the HIF-1α/VEGF axis, particularly at 590 nm; (v) anti-apoptotic remodelling of the Bcl-2/Bax ratio with reduced cytochrome c release and caspase-3/9 activation; and (vi) PGC-1α/TFAM/NRF1-driven mitochondrial biogenesis, alongside restoration of fission/fusion homeostasis (Drp1, Mfn1/2, Opa1) and PINK1/Parkin-mediated mitophagy. Wavelength specificity has a defined molecular basis: 590 nm modulates VEGF signalling and RPE pump activity, 660 nm interacts with the CuB centre and enhances O₂ binding at CcO, and 850 nm is absorbed by CuA and supports electron entry into complex IV. A second molecular axis is the bidirectional crosstalk between PBM and the circadian system: mitochondrial respiration, ATP turnover and CcO activity oscillate over the 24 h cycle under the control of the BMAL1/CLOCK and PER/CRY core machinery, the NAD⁺/SIRT1–SIRT3 axis and REV-ERBα. Preliminary preclinical and human observations suggest that NIR-induced bioenergetic and functional gains may be coupled to this rhythm, with greater benefit reported when light is delivered in the morning window (≈08:00–11:00); this time dependence should be regarded as an emerging hypothesis rather than an established clinical principle. The clinical evidence is unevenly developed across indications. It is most robust for non-exudative age-related macular degeneration, where multiwavelength PBM (590/660/850 nm; Valeda Light Delivery System) has shown disease-modifying potential in randomized controlled trials (LIGHTSITE I–III and the LIGHTSITE IIIB extension), with sustained BCVA gains and reduced incidence of geographic atrophy over 24 months and beyond. Evidence for retinitis pigmentosa, central serous chorioretinopathy and, with red-light monotherapy, childhood myopia is at present limited to small or short-term studies and remains preliminary. This narrative review synthesizes the molecular machinery engaged by PBM, integrates clinical findings across retinal diseases and discusses how chronotherapeutic delivery of light, aligned with the molecular clock, may further optimize therapeutic efficacy. Full article

During startup, ransomware is associated with abnormal fluctuations in underlying hardware resources. Hardware Performance Counters (HPC) can characterize this ultra-early behavior without interference from software-based countermeasures. However, existing studies lack a cross-platform hardware-layer analysis paradigm and typically neglect the first 10 s post-execution. This study selects two platforms—Windows 7 (homogeneous x86) and Windows 10 (Intel performance hybrid architecture with P-core (performance core) and E-core (efficiency core))—and constructs a large-scale dataset (1721 ransomware and 1039 benign samples on Windows 7; 1562 ransomware and 718 benign on Windows 10). On Windows 7, 25 HPC events are monitored. On Windows 10, each event yields two instance-level metrics (P-core and E-core), resulting in 42 instance-level metrics. Using statistical analysis (Pearson correlation, fold change) and feature selection (Random Forest + clustering), four core metrics are independently selected per platform. Windows 7 favors LLC and branch events (increasing trends, fold change ≥ 1.5, e.g., LLC-store_std), while Windows 10 favors P/E-core branch and cache events (decreasing trends, fold change ≤ 0.667, e.g., cpu_atom_branch-load-misses_max). The 10 s window is divided into startup (0–2 s), key generation (2–5 s), and encryption (5–10 s) phases. Results indicate opposite correlation patterns: resource-enhanced disturbance (positive correlation, fold change ≥ 1.5) on Windows 7 versus resource-suppressed disturbance (negative correlation, fold change ≤ 0.667) on Windows 10. Critically, startup-phase HPC events exhibit substantially stronger correlation on Windows 10 (S-level, >85%) compared to Windows 7 (A-level, 70–84%). This difference may be associated with the fine-grained P/E-core separation, which preserves core-type behavioral information that is aggregated and lost on homogeneous platforms. This study contributes a cross-platform correlation framework, observes an architecture-dependent inversion pattern of HPC responses, and suggests that core-type granularity—rather than event quantity—is associated with stronger feature–behavior correlations on heterogeneous architectures, providing preliminary empirical insights for future lightweight detection system design. Full article

The genus Aegilops comprises important wild relatives of cultivated wheat and represents a valuable genetic resource for wheat improvement. In this study, the complete chloroplast genomes of five Aegilops species (Ae. crassa, Ae. cylindrica, Ae. juvenalis, Ae. tauschii, and Ae. triuncialis) collected from Kazakhstan and Uzbekistan were sequenced, assembled, and comparatively analyzed. The chloroplast genomes exhibited a conserved quadripartite structure consisting of a large single-copy (LSC), a small single-copy (SSC), and two inverted repeat (IR) regions. Genome sizes ranged from 135,612 to 136,840 bp, with an identical GC content of 38% across all species. Comparative analyses revealed high structural conservation among chloroplast genomes, particularly within IR regions, whereas greater sequence divergence was observed in the non-coding regions of the LSC and SSC. Sliding-window analysis identified several highly polymorphic regions, including rpl32-trnL(UAG), ndhF-rpl32, trnC(GCA)-rpoA, psbA, and ndhD, which may serve as potential DNA barcodes and informative markers for phylogenetic studies. A total of 850 chloroplast simple sequence repeats (SSRs) were detected, predominantly A/T-rich mononucleotide repeats. Codon usage analysis demonstrated a conserved preference for A/U-ending codons across all species. Ka/Ks analysis indicated that most chloroplast protein-coding genes are under strong purifying selection, although relatively elevated evolutionary rates were detected in rpoA and ycf4. Phylogenetic analyses based on complete chloroplast genomes strongly supported sectional relationships within Aegilops and confirmed close maternal relationships among several species. Overall, this study provides chloroplast genome resources for Aegilops and contributes to understanding chloroplast genome evolution, phylogeny, and molecular marker development. Full article

Lost circulation in fractured formations is a major challenge during drilling operations, while conventional plugging evaluation methods relying solely on pressure-bearing curves and fluid-loss data often fail to accurately distinguish effective internal plugging from ineffective plugging behavior. To address this issue, a visualized plugging evaluation apparatus with high pressure-bearing capacity and large-window observation capability was developed to directly observe the plugging process and evaluate plugging performance under different fracture conditions. Based on the Ideal Packing Theory and the D₉₀ rule, plugging formulations were systematically evaluated under different fracture-width coefficients, slurry concentrations, and fracture-width conditions. The results showed that excessively large fracture-width coefficients or excessively high slurry concentrations could lead to premature “external plugging,” in which plugging materials accumulated near the fracture entrance without forming effective internal plugging structures. Although such cases exhibited rapid pressure buildup, visual observations confirmed that the fracture itself remained insufficiently sealed. Under the present experimental conditions, the optimized formulation with a fracture-width coefficient of 0.8 W and a slurry concentration of 25% exhibited the best overall plugging performance. The formulation reached 10 MPa in approximately 2650 s and successfully formed stable internal plugging structures under different fracture-width conditions, with the maximum variation in plugging time remaining within 7%. Field applications in Well BD-X further validated the effectiveness of the proposed method and optimized formulations under real drilling conditions. The developed apparatus and evaluation method provide a reliable experimental approach for optimizing plugging formulations and preventing lost circulation in fractured formations. Full article

To address the high deployment cost, insufficient local coverage, and limited timeliness of conventional wave-observation methods in onboard real-time applications, this study conducts a comparative investigation of centre-of-gravity-equivalent instantaneous wave-height estimation models based on three-degree-of-freedom ship motion responses under the framework of the wave buoy analogy (WBA). The heave, roll, and pitch responses of a 1:2 scaled Series 62 4667-1 planing craft model in regular head seas are used as inputs, while the synchronous instantaneous wave-height signal measured by a wave probe near the centre of gravity is used as the label. A unified protocol is established with consistent inputs, labels, window construction, data partitioning, and evaluation metrics. Six models, namely SVR, TCN, LSTM, CNN-LSTM, Transformer, and LSTM-MHA, are compared and validated using STAR-CCM+ numerical simulation data and towing-tank experimental data. The results indicate that, in the simulated case of H = 0.10 m and T = 1.5 s, LSTM-MHA achieves the highest estimation accuracy, with RMSE and R² values of 0.001231 and 0.997848, respectively, but it also has the largest model size and computational cost. In comparison, TCN achieves near-optimal accuracy with a smaller parameter count and lower inference latency, and shows stable performance across multiple conditions. The towing-tank experimental results further show that both LSTM-MHA and TCN clearly outperform the SVR baseline. Overall, accuracy in the simulation domain, robustness in the towing-tank experimental domain, and cross-domain generalisation capability are not fully consistent. Therefore, the selection of onboard instantaneous wave-height estimation models should jointly consider estimation error, model complexity, computational latency, window length, and practical deployment requirements. Full article