Browse Articles

A structural health monitoring data reconstruction method based on VMD and SSA-optimized GRU model

Abstract In the field of Structural Health Monitoring (SHM), complete datasets are fundamental for modal identification analysis and risk prediction. However, data loss due to sensor failures, transmission interruptions, or hardware issues is a common problem. To address this challenge, this study develops a method combining Variational Mode Decomposition (VMD) and Sparrow Search Algorithm (SSA)-optimized Gate Recurrent Unit (GRU) for recovering structural response data. The methodology initially employs Variational Mode Decomposition (VMD) to preprocess and decompose the existing data from the target sensor into Intrinsic Mode Functions (IMFs) and residuals. Subsequently, the Gated Recurrent Unit (GRU) network utilizes data from other sensors to reconstruct the IMFs and residuals, ultimately producing the data reconstruction results. During this process, Singular Spectrum Analysis (SSA) is used to optimize the hyperparameters of the GRU network. To validate the effectiveness of this method, we utilized one month of monitoring data collected from a certain project and a publicly available dataset. On the public dataset, we tested performance at different data loss rates. Results show that, compared to a standalone GRU model and a VMD + GRU model, the VMD + SSA + GRU model’s reconstruction data root mean squared error is reduced by 46.61% and 32.57% on average, respectively, while the coefficient of determination increases by 38.74% and 18.50%. The data reconstruction method proposed in this study can accurately capture trends in missing data, without the need for manual hyperparameter tuning, and the reconstruction results are highly consistent with the real data.

Different keratoconus definitions can lead to substantial prevalence disparities in population-based studies

Abstract This report explores the prevalence of keratoconus in a population-based cohort of adults aged 40 or older according to ten different definitions. All Rotterdam Study participants with reliable Pentacam scans and no prior corneal refractive surgery were cross-sectionally analysed (n = 2660). First, we applied a novel evidence-based definition. Suspected keratoconus was defined as having at least one eye with a final D-index (BAD-D) ≥ 2.6. Manifest keratoconus was defined as having at least one eye with: (1) BAD-D ≥ 2.6; and (2) a score of at least 4/10 on the novel Rotterdam Keratoconus Scale (RKS); and (3) a confirming assessment of the relevant Pentacam maps; and (4) meeting Holladay’s criteria in case of recent contact lens usage. Using this proposed definition, 72 participants (2.71%, 95%CI: 2.16–3.40%) had suspected keratoconus, while 10 participants (0.38%, 95%CI: 0.20–0.69%) had manifest keratoconus. To assess reproducibility, two specialists independently applied the proposed definition, with a substantial inter-observer agreement (Kappa = 0.74). Interestingly, 6(60%) patients were unaware of having keratoconus. Applying nine alternative definitions from similar screening studies produced prevalence estimates ranging from 0.19 to 9.29% in the same cohort. Moreover, counting solely on a BAD-D cutoff of 2.6 to define keratoconus was unreliable, with a low positive predictive value of 14%. These findings explain partially the large heterogeneity in the reported keratoconus prevalences, underscoring the need for a standardized definition.

Comparative analysis of brushless DC and switched reluctance motors for optimizing off-grid water pumping

Mutual solubility of ammonium perrhenate in solutions containing ammonium salts

Clinical performance of real-time nanopore metagenomic sequencing for rapid identification of bacterial pathogens in cerebrospinal fluid: a pilot study

An ultrawideband monopulse feed with slant polarization for tracking radar systems

Drug-induced differential culturability in diverse strains of Mycobacterium tuberculosis

Experimental study on the influencing factors and pore production law of CO2 huff-and-puff in tight sandstone reservoirs

Activation of Wnt/β-catenin in neural progenitor cells regulates blood–brain barrier development and promotes neuroinflammation

Soliton solutions of the (2 + 1)-dimensional Jaulent-Miodek evolution equation via effective analytical techniques

The role of CLDN11 in promotion of granulosa cell proliferation in polycystic ovary syndrome via activation of the PI3K-AKT signalling pathway

Retraction Note: hERG1 channels modulate integrin signaling to trigger angiogenesis and tumor progression in colorectal cancer

Pilot-scale phosphorus recovery from mobile toilet wastewater in Bangkok, Thailand

An integrated approach to predict genetic risk for Mosquito-Borne diseases in the local Population of Tehsil Haripur, Khyber Pakhtunkhwa, Pakistan

Risk of second primary malignancies among survivors of cutaneous melanoma: A nationwide population-based study in the Republic of Korea

Discovery of two novel Flavobacterium species with potential for complex polysaccharide degradation

Greater residential greenness is associated with reduced epigenetic aging in adults

Abstract Potential pathways linking urban green spaces to improved health include relaxation, stress alleviation, and improved immune system functioning. Epigenetic age acceleration (EAA) is a composite biomarker of biological aging based on DNA methylation measurements; it is predictive of morbidity and mortality. This cross-sectional study of 116 adult residents of a metropolitan area in central North Carolina investigated associations between exposure to residential green spaces and EAA using four previously developed epigenetic age formulas. DNA methylation tests of white blood cells were conducted using Illumina MethylationEPIC v1.0 assays. EAA values were calculated as residuals from the linear regression model of epigenetic age on chronological age. Residential greenness was characterized using tree cover, total vegetated land cover, and normalized difference vegetation index (NDVI) data. An interquartile range (IQR) increase in distance-to-residence weighted average greenness within 500 m of residence was consistently associated with a reduced EAA adjusted for sociodemographic covariates, smoking status, white blood cell fractions, and the two-dimensional spline function of geographic coordinates. The reduction in the EAA estimates for the four EAA measures ranged from − 1.0 to − 1.6 years for tree cover, from − 1.2 to − 1.5 years for vegetated land cover, and from − 0.9 to − 1.3 years for the NDVI; 11 of the 12 associations were statistically significant (p < 0.05). This study produced new evidence linking reduced epigenetic aging to greater greenness near residences.

A novel arc detection and identification method in pantograph-catenary system based on deep learning

Correction for Toubdji et al., Exploring a unique class of flavoenzymes: Identification and biochemical characterization of ribosomal RNA dihydrouridine synthase

Waste marble sludge and calcined clay brick powders in conventional cement farina production for cleaner built environment