CNN-LSTM Hybrid Model for Kinematic Feature Analysis and Parabolic Radian Prediction in Basketball Videos

With the improvement of living standards around the world, people's love for sports has also increased; basketball is especially loved by people. It is of great importance to provide sound motor instruction for basketball. To this end, this paper comprehensively investigates the dependence between the optimal release conditions and the corresponding shooting arm movements in basketball players. We carry out kinematic feature analysis of basketball sports videos, propose a hybrid CNN-LSTM model that can predict the arc of the shooting parry, and identify the key movements of the arm joint that produce optimal release velocity, angle, and backspin in short-, mid-, and long-range shots. The experiment demonstrates that the model has three rigid planar links with rotational joints that mimic the shoulder, elbow, and wrist joints of the upper arm, forearm, and hand, which are better at guiding the optimal ball release speed, angle, and backspin for different players with the fastest ball speed being about 4.6 m/s and the slowest being about 1.7 m/s.

Kinematic complexity around NGC 419: resolving the proper motion of the cluster, the Small Magellanic Cloud, and the Magellanic bridge

ABSTRACT We present Hubble Space Telescope proper motions in the direction of the star cluster NGC 419 in the Small Magellanic Cloud. Because of the high precision of our measurements, for the first time it is possible to resolve the complex kinematics of the stellar populations located in the field, even along the tangential direction. In fact, the proper motions we measured allow us to separate cluster stars, which move on average with ($\mu _{\alpha }\cos \delta ^{\rm NGC\, 419}, \mu _{\delta }^{\rm NGC\, 419}$) = (+0.878 ± 0.055, −1.246 ± 0.048) mas yr−1, from those of the Small Magellanic Cloud and those belonging to a third kinematic feature that we recognize as part of the Magellanic Bridge. Resolving such a kinematic complexity enables the construction of decontaminated colour–magnitude diagrams, as well as the measurement of the absolute proper motion of the three separate components. Our study therefore sets the first steps towards the possibility of dynamically investigating the Magellanic system by exploiting the resolved kinematics of its stellar clusters.

EXPERIMENTAL DISCUSSION ABOUT THE INFLUENCE OF THE PROFICIENCY IN TANKENDO IN THE FOOT POSTURE

Purpose: In martial-art plays using a weapon, the length and weight of the used weapon determine the timing of attacking the opponent and playing strategies, which may be in turn reflected on the body posture and foot posture of a player. The objective of this study is to analyze the features of the food posture of a skilled player in Tankendo, in which players play using a short and light bamboo knife-like sword in order to consider an effective playing strategy. Methodology: In our experiment, the subjects were asked to take the foot posture at the temporal and spatial timing kept to measure and quantify kinematic feature quantities, weight distribution between both the feet placed in the front and rear, respectively and favorite jump distance of them. Then, a one-to-one correlation analysis was conducted among all the feature values. Main Findings: The result of the analysis demonstrated that a strong negative correlation was observed between the number of years of experience in Tankendo and the favorite jump distance. Similarly, a strong negative correlation was observed between the number of years of experience in Jukendo and favorite jump distance. On the other hand, in the case of Kendo, a strong negative correlation was observed between the number of years of experience in Kendo and the width between the feet placed on the right and left sides. Implications/Applications: A series of results obtained from the study suggests that in Tankendo and Jukendo, players have such a tendency that they first would take a position near the opponent and then jump there up to strike the opponent. In contrast, in case of Kendo focusing on a thrusting technique, such a tendency was observed that with a narrow width between both the feet, players stroke their opponent so that speedy footwork might be achieved, despite easily losing body balance.