The New Type of the Olbian Copper Coin from the Time of Mithridates Eupator

All Olbian coins from the time of Mithridates Eupator that have been known and described in scientific and reference numismatic literature are anepigraphic in nature and it is difficult to date them clearly. The small copper coin of Apollo Gorytos type, which we found in one of the Ukrainian collections, has an alpha-shape monogram with broken gasta, to the right from Apollo’s head. This coin allows us to suggest a possible dating of these coins. We believe that coins with A (alpha) monogram could have been minted in 105 BC, in the year of Apollo in Olbia, that is, several years after the city became part of the Kingdom of Pontus.

Mechanism of Actions of Dexamethasone against COVID-19 predicted by Alpha Shape Analysis of Binding Sites

Background: COVID-19 emerged in late 2019 and became a pandemic disease with severe mortality and morbidity. No specific remedy exists at present, but some drugs, such as Dexamethasone, have shown clinical benefits against the causative agent, the SARS-CoV-2 virus. Objective: To analyze the binding affinity between drugs and an SARS-CoV-2 protein through geometrical methods and to study the theoretical effectiveness of Dexamethasone as a potential treatment for COVID-19. Method: The binding affinity of Dexamethasone to the target SARS-CoV-2 protein was compared with those of different inhibitors. Drug molecules were docked to the SARS-CoV-2 main protease, and the system was simulated by molecular dynamics, allowing alpha shape analysis to extract geometrical features, such as the matching rates of atoms, solid angles, and the distances between atoms at interfaces. Binding affinities between drugs and the main protease were assessed by these geometrical data and the free energy of binding. Results: The behaviour of Dexamethasone was similar to other inhibitors. The efficacy of Dexamethasone as a treatment may be due to it being a glucocorticoid and its properties as a potent inhibitor. Conclusion: This study revealed the mechanism of action of Dexamethasone and provided a geometrical method to distinguish among potential drugs for the treatment of COVID-19.

Canopy Parameter Estimation of Citrus grandis var. Longanyou Based on LiDAR 3D Point Clouds

The characteristic parameters of Citrus grandis var. Longanyou canopies are important when measuring yield and spraying pesticides. However, the feasibility of the canopy reconstruction method based on point clouds has not been confirmed with these canopies. Therefore, LiDAR point cloud data for C. grandis var. Longanyou were obtained to facilitate the management of groves of this species. Then, a cloth simulation filter and European clustering algorithm were used to realize individual canopy extraction. After calculating canopy height and width, canopy reconstruction and volume calculation were realized using six approaches: by a manual method and using five algorithms based on point clouds (convex hull, CH; convex hull by slices; voxel-based, VB; alpha-shape, AS; alpha-shape by slices, ASBS). ASBS is an innovative algorithm that combines AS with slices optimization, and can best approximate the actual canopy shape. Moreover, the CH algorithm had the shortest run time, and the R2 values of VCH, VVB, VAS, and VASBS algorithms were above 0.87. The volume with the highest accuracy was obtained from the ASBS algorithm, and the CH algorithm had the shortest computation time. In addition, a theoretical but preliminarily system suitable for the calculation of the canopy volume of C. grandis var. Longanyou was developed, which provides a theoretical reference for the efficient and accurate realization of future functional modules such as accurate plant protection, orchard obstacle avoidance, and biomass estimation.

Object Pose Estimation for Robot Loading in Accommodation Space Using Alpha-Shape Algorithm

Robots with visual sensors have been used in various goods logistics, such as bin picking or uploading. However, there are more and more demands for the automatic blanking and loading, it is necessary to solve the problem of object pose estimation in changing accommodation space. This paper proposes a method for pose estimation in the accommodation space using alpha-shape algorithm and improved Fruit fly Optimization Algorithm (FOA). The alpha-shape volume variety of object and measured space is set to the objective function and the pose variety of object is set to six variables of improved FOA. The experiments were performed by setting parameters of improved FOA and considering the four space types represented the common accommodation shapes. Compared with previous work using convex hull, the new study using alpha-shape algorithm not only keeps the object in the accommodation space, but also maintains the object pose is at the bottom of the space and can meet the practical requirement of object placement by robot arms.

Reconstruction of a fluttering flag from a single image

Reconstructing a 3 D object from a single image is a challenging task because determining useful geometric structure information from a single image is difficult. In this paper, we propose a novel method to extract the 3 D mesh of a flag from a single image and drive the flag model to flutter with virtual wind. A deep convolutional neural fields model is first used to generate a depth map of a single image. Based on the Alpha Shape, a coarse 2 D mesh of flag is reconstructed by sampling at different depth regions. Then, we optimize the mesh to generate a mesh with depth based on Restricted Frontal-Delaunay. We transform the Delaunay mesh with depth into a simple spring model and use a velocity-based solver to calculate the moving position of the virtual flag model. The experiments demonstrate that the proposed method can construct a realistic fluttering flag video from a single image.