Search Results (121)

The 3D point cloud generated by MVSNet has good scene integrity but lacks sensitivity to details, causing holes and non-dense areas in flat and weak-texture regions. To address this problem and enhance the point cloud information of weak-texture areas, the BCA-MVSNet network is proposed in this paper. The network integrates the Bidirectional Feature Pyramid Network (BIFPN) into the feature processing of the MVSNet backbone network to accurately extract the features of weak-texture regions. In the feature map fusion stage, the Coordinate Attention (CA) mechanism is introduced into 3DU-Net to obtain the position information on the channel dimension related to the direction, improve the detail feature extraction, optimize the depth map and improve the depth accuracy. The experimental results show that BCA-MVSNet not only improves the accuracy of detail texture reconstruction, but also effectively controls the computational overhead. In the DTU dataset, the Overall and Comp metrics of BCA-MVSNet are reduced by 10.2% and 2.6%, respectively; in the Tanksand Temples dataset, the Mean metrics of the eight scenarios are improved by 6.51%. Three scenes are shot by binocular camera, and the reconstruction quality is excellent in the weak-texture area by combining the camera parameters and the BCA-MVSNet model. Full article

Three-Dimensional Gaussian Splatting (3DGS) has revolutionized novel-view synthesis, enabling real-time rendering of high-quality scenes. Two-Dimensional Gaussian Splatting (2DGS) improves geometric accuracy by replacing 3D Gaussians with flat 2D Gaussians. However, the flat nature of 2D Gaussians reduces mesh quality on volumetric surfaces and results in over-smoothed reconstruction. To address this, we propose Dual-Dimensional Gaussian Splatting (DDGS), which integrates both 2D and 3D Gaussians. First, we generalize the homogeneous transformation matrix based on 2DGS to initialize all Gaussians in 3D. Subsequently, during training, we selectively convert Gaussians into 2D representations based on their scale. This approach leverages the complementary strengths of 2D and 3D Gaussians, resulting in more accurate surface reconstruction across both flat and volumetric regions. Additionally, to mitigate over-smoothing, we introduce gradient-based regularization terms. Quantitative evaluations on the DTU and TnT datasets demonstrate that DDGS consistently outperforms prior methods, including 3DGS, SuGaR, and 2DGS, achieving the best Chamfer Distance and F1 score across a wide range of scenes. Full article

With the rapid advancement of smart forestry, 3D reconstruction and the extraction of structural parameters have emerged as indispensable tools in modern forest monitoring. Although traditional methods involving LiDAR and manual surveys remain effective, they often entail considerable operational complexity and fluctuating costs. To provide a cost-effective and scalable alternative, this study introduces FS-MVSNet—a multi-view image-based 3D reconstruction framework incorporating feature pyramid structures and attention mechanisms. Field experiments were performed in three representative forest parks in Beijing, characterized by open canopies and minimal understory, creating the optimal conditions for photogrammetric reconstruction. The proposed workflow encompasses near-ground image acquisition, image preprocessing, 3D reconstruction, and parameter estimation. FS-MVSNet resulted in an average increase in point cloud density of 149.8% and 22.6% over baseline methods, and facilitated robust diameter at breast height (DBH) estimation through an iterative circle-fitting strategy. Across four sample plots, the DBH estimation accuracy surpassed 91%, with mean improvements of 3.14% in AE, 1.005 cm in RMSE, and 3.64% in rRMSE. Further evaluations on the DTU dataset validated the reconstruction quality, yielding scores of 0.317 mm for accuracy, 0.392 mm for completeness, and 0.372 mm for overall performance. The proposed method demonstrates strong potential for low-cost and scalable forest surveying applications. Future research will investigate its applicability in more structurally complex and heterogeneous forest environments, and benchmark its performance against state-of-the-art LiDAR-based workflows. Full article

When analyzing the dynamics of wind turbines under the action of wind and ground motion, mass–point models cannot accurately predict the dynamic response of the structure. Additionally, the coupling effect between the pile foundation and the soil affects the vibration characteristics of the wind turbine. In this paper, the dynamic response of a DTU 10 MW wind turbine under the coupling effect of wind and an earthquake is numerically studied through the combined simulation of finite-element software ABAQUS 6.14-4 and OpenFAST v3.0.0. A multi-pile foundation is used as the foundation of the wind turbine structure, and the interaction between the soil and the structure is simulated by using p-y curves in the numerical model. Considering the coupling effect between the blade and the tower as well as the soil–structure coupling effect, this paper systematically investigates the vibration response of the blade–tower coupled structure under dynamic loads. The study shows that: (1) the blade vibration has a significant impact on the tower’s vibration characteristics; (2) the ground motion has varying effects on blades in different positions and will increase the out-of-plane vibration of the blades; (3) the SSI effect has a substantial impact on the out-of-plane vibration of the blade, which may cause the blade to collide with the tower, thus resulting in the failure and damage of the wind turbine structure. Full article

Floating offshore wind turbines present peculiar characteristics that make them particularly interesting for the implementation of wind farm control strategies such as wake mixing to increase the overall power production. Wake mixing is achieved by generating an unsteady cyclical load on the blades of upwind turbines to decrease the wind deficit on downwind turbines. The possibility of exploiting the yaw motion of a floating offshore wind turbine allows for amplified wake mixing or a reduction in the workload of the control mechanism. To amplify the yaw motion of the system at a selected excitation frequency, a multi-disciplinary optimization framework was developed to modify selected properties of the floating platform and mooring line configuration of the DTU 10 MW turbine on the Triple Spar platform. At the same time, operational and structural constraints were taken into account. A simulation-based approach was chosen to design a floating platform and mooring line configuration that were optimized to integrate with the new control strategy based on wake mixing in floating offshore wind farms. Modifying the floating platform spar arrangement and mooring line properties allowed us to tune the yaw natural frequency of the system in accordance with the excitation frequency of the wake control technique and amplify the yaw motion while controlling the deviations of the operational constraints and costs from the baseline configuration. Full article

The objective of this paper is to carry out response analyses of eight floating wind turbines and compare them together; this is something that is not seen in previous research papers. From this perspective, this paper will compare the response offset regarding the motions of the six degrees of freedom of the respective floating wind turbines. The applied forces that these analyses consider come mainly from constant wind forces applied on the wind turbines’ blades, as well as forces from waves and currents. Different response offset values are considered and compared regarding the different constant wind speeds, as well as the different velocities of waves and currents. This paper also provides various innovative references related to floating wind turbine analyses and software. Validation and verification studies are left for future work due to the complexity of the data provided in this paper. However, some comparisons are made between the obtained analysis results and some external references. The mentioned external references unfortunately have floating wind turbines with different wind and wave environmental conditions, power capacities, and dimensional characteristics. The results of the constant wind dynamic analysis of the eight floating wind turbines studied in this paper have shown that the maximum surge, sway, and heave response offset corresponds to the DTU Spar 1 floating wind turbine. The maximum roll and yaw response offset corresponds to the INO-WINDMOOR floating wind turbine. The maximum pitch response offset corresponds to the WindFloat floating wind turbine. The aero-hydro-servo-elastic method was used in the Sima software to run the analyses. It is a time-domain dynamic analysis, and it uses meters [m] and degrees [°] to describe the response offsets of the different floating wind support structures studied in this paper. Full article

For steady transgenic expression, lentiviral vector-mediated gene delivery is a commonly used technique. One question that needs to be explored is how external lentiviral vectors and overexpressed genes perturb cellular homeostasis, potentially altering transcriptional networks. In this study, two Human Embryonic Kidney 293T (HEK293T)-derived cell lines were established via lentiviral transduction, one overexpressing green fluorescent protein (GFP) and the other co-overexpressing GFP and ADORA3 following puromycin selection to ensure stable genomic integration. Genes with differentially transcript utilization (gDTUs) and differentially expressed genes (DEGs) across cell lines were identified after short-read and long-read RNA-seq. Only 31 genes were discovered to have changed in expression when GFP was expressed, although hundreds of genes showed variations in transcript use. In contrast, even when co-overexpression of GFP and ADORA3 alters the expression of more than 1000 genes, there are still less than 1000 gDTUs. Moreover, DEGs linked to ADORA3 overexpression play a major role in RNA splicing, whereas gDTUs are highly linked to a number of malignancies and the molecular mechanisms that underlie them. For the analysis of gene expression data from stable cell lines derived from HEK293T, our findings provide important insights into changes in gene expression and alternative splicing. Full article

Trypanosoma cruzi, the causal agent of Chagas disease, exhibits great genetic diversity, which has been related to its biological properties. However, these are poorly known in strains from the endemic area of Hidalgo. To assess the parasite’s virulence, we evaluated parasitemia, mortality, and tropism in thirteen organs of CD1 mice during the acute phase of infection. For genotyping, we amplified the mini-exon gene from T. cruzi DNA using PCR. All five isolates were identified as belonging to DTU TcI. The peak of parasitemia occurred between 25 and 29 days post-infection. The Tultitlán and Olma isolates did not cause any mouse deaths, whereas Ixcatépec produced 100% mortality. Mice infected with the Barrio Hondo isolate exhibited the highest parasitemia, while those infected with Cuatecomaco had the lowest. The five isolates generated varying degrees of infection and chronic inflammation; only two isolates triggered acute pancreatitis and myocarditis. No amastigote nests were found in the hearts of mice infected with the Ixcatépec isolate. Our findings suggest that the damage caused by T. cruzi strains from Hidalgo may extend beyond cardiac lesions in the acute phase of Chagas disease regardless of their classification as TcI and variability in parasitemia levels. Full article

To facilitate both the installation and the removal of floating offshore wind turbines (FOWTs), a novel tension-leg dual-module offshore wind turbine system has been proposed. This system primarily consists of a DTU 10 MW wind turbine (WT) module and a supporting tension-leg platform (TLP) module. Considering both mechanical and hydrodynamic coupling effects of the dual-module system, this study focuses on its dynamic responses during both the installation and the removal of the WT module under typical sea states. The effect of different installation vessel positions and key parameters of the clamping device on the dynamic response of the system during the WT module removal has been clarified. Based on the findings, preliminary recommendations are provided regarding the optimal positioning of the installation vessel and the optimal design parameters of the clamping device. Furthermore, an auxiliary sleeve has been proposed to facilitate the WT module removal. The results indicate that the application of the auxiliary sleeve can significantly improve the dynamic response of the system. The results of this study can serve as a reference for the design, installation, and removal of floating offshore wind turbines. Full article

The blades of wind turbines constitute key components for converting wind energy into electrical energy, and modifications to blade airfoil geometry can effectively enhance aerodynamic performance of wind turbine. The trailing edge flap enables load control on the blades through adjustments of its motion and geometric parameters, thereby overcoming limitations inherent in conventional pitch control systems. However, current research primarily emphasizes isolated parametric effects on airfoil performance, with limited exploration of interactions between multiple design variables. This study adopts a numerical simulation approach based on the FFA-W3-241 airfoil of the DTU 10 MW. Geometric deformations are achieved by manipulating flap parameters, and the influence on airfoil aerodynamic performance is analyzed using computational fluid dynamics methods. Investigations are conducted into the effects of flap lengths and deflection angles on airfoil aerodynamic characteristics. The results show the existence of an optimal flap length and deflection angle combination. Specifically, when the flap length is 0.1$c$ and the deflection angle is 10°, the lift-to-drag ratio demonstrates significant improvement under defined operational conditions. These findings offer practical guidance for optimizing wind turbine airfoil designs. Full article

Chagas disease is a neglected disease caused by the parasite Trypanosoma cruzi, a public health problem in both endemic and non-endemic countries. In Mexico, the southern region is considered endemic, and cases are frequently reported; however, in the northwestern region, only a few cases are confirmed annually. This study describes, for the first time, the Discrete Typing Unit (DTU) of Trypanosoma cruzi in a volunteer blood donor rejected for being reactive in the northwestern region of Mexico. Seroreactivity was confirmed using “in-house” ELISAs which employed three different antigens: total extract from Trypanosoma cruzi isolated from a vector (Triatoma rubida) from Sonora (strain T1), strain H1 and CL-Brener. The molecular characterization of Trypanosoma cruzi was conducted by amplifying satellite DNA by qPCR and posterior sequencing of the mini-exon gene, using Next Generation Sequencing (NGS) to enhance the accuracy of genetic characterization. The results show that the reactive status of this blood donor was confirmed using our in-house ELISAs, and the presence of Trypanosoma cruzi by detecting TcI DTU confirmed the infection status. Full article

The integration of the global navigation satellite system (GNSS) and the inertial navigation system (INS) is a well-established method for achieving accurate positioning, especially in applications involving unmanned aerial vehicles (UAVs). UAVs are increasingly used across various fields, yet they face challenges such as the need for real-time processing and the impact of low-quality measurements from cost-effective devices. To address these challenges, we propose a velocity-constrained, enhanced, real-time, low-cost, GNSS/INS integrated navigation algorithm and design an algorithmic platform based on the open-source software KF_GINS. The algorithm supports loosely coupled integration of GNSS position data and raw inertial measurement unit (IMU) data, utilizing a 4G data transmission unit (DTU) for real-time data transmission and performing loosely coupled computations on the received data. Subsequently, we successfully applied this algorithm to low-cost integrated navigation devices, such as UAVs. We tested the algorithm platform using one set of vehicle-mounted data and six UAV datasets. Experimental results indicate that the algorithm platform effectively performs computations under various conditions, improving single-point positioning (SPP) accuracy by up to 15.38% horizontally and 6.78% vertically. These findings demonstrate the algorithm platform’s capability to significantly enhance the accuracy and stability of integrated navigation positioning for UAVs. Full article

Phenotypic modifications and their effects on cellular functions through the up-regulation of target gene expression have frequently been observed in genetic studies, but the unique roles of cell lines and their introduced plasmids in influencing these functions have not been fully revealed. In this research, we developed two distinct cell lines derived from the A549 cell line: one that stably overexpresses GFP and another that is a polyclonal stable line overexpressing both GFP and P2RY12. We then utilized transcriptome sequencing (RNA-seq) technology to screen out differentially expressed genes (DEGs) and genes with differential transcript usage (gDTUs) after GFP overexpression (GFP-OE) and P2RY12 overexpression (P2RY12-OE). We found that, compared with A549, there were more than 1700 differentially expressed genes (DEGs) in both GFP-OE and P2RY12-OE cells, while only 866 DEGs were identified in GFP-OE and P2RY12-OE cells. Notably, the differences in transcript usage were relatively minor, with only over 400 genes exhibiting changes across all three groups. The functional analysis of DEGs and gDTUs showed that they were both highly enriched in the pathways associated with cell proliferation and migration. In summary, we performed an extensive analysis of the transcriptome profile of gene expression and alternative splicing with GFP-OE and P2RY12-OE, enhancing our comprehension of how genes function within cells and the processes that control gene expression. Full article

Accurate ocean tide models are required to remove tidal loading effects in geophysical research. Beyond a mere intercomparison, the accuracy of eight modern global models (DTU10, EOT20, FES2014b, FES2022b, GOT4.10c, HAMTIDE11a, OSU12, TPXO10-atlas-v2) and one regional model (NAO99Jb) was assessed in the eastern China marginal seas (ECMSs) using geodetic measurements. This involved rigorous comparisons with the tidal constant measurements at 65 tide gauges and with the GPS-measured M₂ vertical ocean tide loading (OTL) displacements at 22 sites. The selected models showed significant disagreements close to the coasts of eastern China and the western Korean Peninsula, where the largest discrepancy for the M₂ constituent could exceed 30 cm. However, EOT20 and FES2014b provided relatively close results, differing by only about 15 cm in Hangzhou Bay. EOT20 compared more favourably than the others to the tidal constant measurements, with a root sum square (RSS) of 11.1 cm, and to the GPS-measured M₂ vertical OTL displacements, with a root mean square (RMS) of 0.49 mm. In addition, to differentiate between ocean tide models with subtle discrepancies when comparing them with the OTL measurements, consideration of the asthenospheric anelasticity effect was necessary. Full article

Triatoma sordida is a native South American species and the most frequently captured triatomine in artificial environments in Brazil. Although considered a secondary vector of Trypanosoma cruzi, it is typically associated with low infection rates. To investigate its role in an endemic area for Chagas disease in northern Minas Gerais, Brazil, we employed a multidimensional approach that combined triatomine capture data with quantitative and qualitative analyses of T. cruzi. A total of 1861 T. sordida specimens were captured, of which 1455 were examined and 210 (14.4%) were found to be infected with T. cruzi. The most prevalent discrete typing unit (DTU) was TcI (80%), followed by TcII (8%), TcV (5%), and TcIII (3%). Molecular techniques provided new insights into the ecology of T. sordida, revealing a higher infection rate than previously reported and a parasitic load lower than that observed in other quantified species. Chickens were confirmed as the primary food source, playing an epidemiological role in maintaining infected insects with four T. cruzi DTUs. The observed diversity of T. cruzi DTUs suggests a lack of environmental segregation, likely due to the extensive movement of various host species between wild and domestic habitats, resulting in overlapping transmission cycles. Full article