Visual inspection of wheat growth has been a useful tool for understanding and implementing agricultural techniques and a way to accurately predict the growth status of wheat yields for economists and policy decision ...Visual inspection of wheat growth has been a useful tool for understanding and implementing agricultural techniques and a way to accurately predict the growth status of wheat yields for economists and policy decision makers.In this paper,we present a polygonal approach for modeling the growth process of wheat ears.The grain,lemma,and palea of wheat ears are represented as editable polygonal models,which can be re-polygonized to detect collision during the growth process.We then rotate and move the colliding grain to resolve the collision problem.A linear interpolation and a spherical interpolation are developed to simulate the growth of wheat grain,performed in the process of heading and growth of wheat grain.Experimental results show that the method has a good modeling effect and can realize the modeling of wheat ears at different growth stages.展开更多
The three-dimensional packing problem is generally on how to pack a set of models into a given bounding box using the smallest packaging volume. It is known as an NP-hard problem. When discussing the packing problem i...The three-dimensional packing problem is generally on how to pack a set of models into a given bounding box using the smallest packaging volume. It is known as an NP-hard problem. When discussing the packing problem in mechanical field, the space utilization of a mechanism is low due to the constraint of mechanical joints between different mechanical parts. Although such a situation can be improved by breaking the mechanism into components at every joint, it burdens the user when reassembling the mechanism and may also reduce the service life of mechanical parts. In this paper, we propose a novel mechanism packing algorithm that deliberately considers the DOFs （degrees of freedom） of mechanical joints. With this algorithm, we construct the solution space according to each joint. While building the search tree of the splitting scheme, we do not break the joint, but move the joint. Therefore, the algorithm proposed in this paper just requires the minimal number of splits to meet the goal of space utilization. Numerical examples show that the proposed method is convenient and efficient to pack three-dimensional models into a given bounding box with high space utilization.展开更多
基金the National Natural Science Foundation of China(Nos.61772474,61872324,and 61822701)the Natural Science Foundation of Henan Province of China(No.162300410262)the Key Research Projects of Henan Higher Education Institutions of China(No.18A413002)。
文摘Visual inspection of wheat growth has been a useful tool for understanding and implementing agricultural techniques and a way to accurately predict the growth status of wheat yields for economists and policy decision makers.In this paper,we present a polygonal approach for modeling the growth process of wheat ears.The grain,lemma,and palea of wheat ears are represented as editable polygonal models,which can be re-polygonized to detect collision during the growth process.We then rotate and move the colliding grain to resolve the collision problem.A linear interpolation and a spherical interpolation are developed to simulate the growth of wheat grain,performed in the process of heading and growth of wheat grain.Experimental results show that the method has a good modeling effect and can realize the modeling of wheat ears at different growth stages.
基金The work was supported by the National Key Research and Development Program of China under Grant No. 2017YFC0804401, the National Natural Science Foundation of China under Grant Nos. 61472370, 61672469, 61379079, 61322204, and 61502433, the Natural Science Foundation of Henan Province of China under Grant No. 162300410262, and the Key Research Projects of Henan Higher Education Institutions of China under Grant No. 18A413002.
文摘The three-dimensional packing problem is generally on how to pack a set of models into a given bounding box using the smallest packaging volume. It is known as an NP-hard problem. When discussing the packing problem in mechanical field, the space utilization of a mechanism is low due to the constraint of mechanical joints between different mechanical parts. Although such a situation can be improved by breaking the mechanism into components at every joint, it burdens the user when reassembling the mechanism and may also reduce the service life of mechanical parts. In this paper, we propose a novel mechanism packing algorithm that deliberately considers the DOFs （degrees of freedom） of mechanical joints. With this algorithm, we construct the solution space according to each joint. While building the search tree of the splitting scheme, we do not break the joint, but move the joint. Therefore, the algorithm proposed in this paper just requires the minimal number of splits to meet the goal of space utilization. Numerical examples show that the proposed method is convenient and efficient to pack three-dimensional models into a given bounding box with high space utilization.
