INTERACTIVE 3D RECONSTRUCTION AND DLT CAMERA CALIBRATION: A MANUAL REGISTRATION APPROACH
Background: This paper presents a straightforward and intuitive method for interactive 3D reconstruction and Direct Linear Transformation (DLT) camera calibration using a single image of a structured scene with known object dimensions. The method relies on manual registration of pairs of points on both the image and the terrain, allowing for precise alignment and calibration. Aim: By utilizing this method, users can easily reconstruct 3D scenes and calibrate cameras without the need for complex algorithms or extensive computational resources. Our approach offers a user-friendly solution for 3D reconstruction and camera calibration, making it accessible to a wider audience and applicable in a range of fields such as computer vision, augmented reality, and virtual reality. Methods: This work primarily focuses on the determination of the projection matrix, which plays a crucial role in mapping 3D points onto a 2D image plane. The projection matrix encapsulates both the intrinsic parameters of the camera (such as focal length and optical center) and the extrinsic parameters (such as camera position and orientation in the world coordinate system). By accurately determining the projection matrix, we can effectively project 3D points onto the 2D image plane, enabling tasks like 3D reconstruction, camera localization, and augmented reality applications. Results: We present experimental results obtained from testing the method on an image of a known object, demonstrating its effectiveness and accuracy in producing realistic 3D reconstructions. Discussion: The method's reliance on manual registration of point pairs allows for precise alignment and calibration without the need for complex algorithms or extensive computational resources. This user-friendly approach makes 3D reconstruction and camera calibration accessible to a wider audience and applicable in various fields. Conclusions: Overall, our approach offers a practical and accessible solution for 3D reconstruction and camera calibration, expanding the potential applications in computer vision, augmented reality, and virtual reality.
Read ArticleHIGH BURDEN OF VITAMIN D DEFICIENCY AND FERRITIN-LINKED IMPACT IN Β-THALASSEMIA MAJOR
Background: Background: Vitamin D plays an essential role in bone health and overall physiological function, and its deficiency is common in children and adolescents with β-thalassemia major (βTM). Iron overload, as reflected by elevated ferritin, may further influence vitamin D status. Aim: This study aimed to evaluate serum vitamin D levels in βTM patients and determine their association with ferritin levels. Methods: A total of 40 βTM patients and 20 age-matched healthy controls (aged 4–25 years) were enrolled between October 2024 and February 2025. Serum vitamin D, calcium, ferritin, and hemoglobin were measured. Statistical analysis, including correlation and logistic regression, was performed using SPSS v.26 to identify predictors of vitamin D deficiency. Results: Vitamin D deficiency was highly prevalent among βTM patients (70%) compared with controls. Patients showed significantly lower vitamin D levels (17.32±1.56) than controls (25.34±1.76). Vitamin D levels were positively correlated with age (r = 0.788), calcium (r = 0.772), and hemoglobin (r = 0.771), and negatively correlated with ferritin (r = −0.517). Logistic regression demonstrated that ferritin >1000 ng/mL strongly predicted vitamin D deficiency (OR = 17.875; 95% CI: 3.258–98.074; p = 0.001), while younger age ( < 10 years) also increased the odds of deficiency (OR = 5.200; p = 0.018). Discussion: D deficiency is a prevalent and intrinsic metabolic disturbance in β-thalassemia major, closely linked to chronic iron overload and elevated ferritin levels. This interplay disrupts hepatic vitamin D hydroxylation, induces inflammation, and contributes to endocrine and skeletal complications, highlighting ferritin as a key predictor of deficiency in these patients. Conclusion: Vitamin D deficiency is highly prevalent in βTM and is strongly associated with elevated ferritin levels, suggesting that iron overload is a significant predictor. Integrating vitamin D assessment into routine monitoring may support better management of disease-related metabolic disturbances in patients with βTM.
Read ArticleCLINICAL AND LABORATORY TESTING OF A NEW MODIFICATION OF TWO-LAYER "SILEP" DENTURES USED IN PROSTHETIC DENTISTRY
Dentistry is a part of medicine, where various polymer materials were used for the first time. Many factors forced researchers to find more stable, versatile, and hygienic materials for the manufacture of dental products. It is important to note that the search for the ideal polymer dental material is still ongoing. This is because modern polymers, in some cases, do not meet the specified requirements for chemical, physical, strength, and elasticproperties. Based on the data on the method of creating and using silicone material for the base of the removable prosthesis "Gossil", an improved silicone material for two-layer dentures "Silep" was developed, as well as a special primer for better connection of the lining with the rigid acrylic base of the prosthesis. To evaluate the most suitable compound, materials were tested for several parameters, such as tensile strength, elongation, and shore hardness. In addition to selecting a suitable material for modification, the selection and testing of an adhesive that allows the chemical bonding of the acrylate surface to the siloxane surface were carried out.
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