When the edges of a convex polygon are traversed along one direction,the interior of the convex polygon is always on the same side of the edges. Based on this characteristic of convex polygons,a new algorithm for comp...When the edges of a convex polygon are traversed along one direction,the interior of the convex polygon is always on the same side of the edges. Based on this characteristic of convex polygons,a new algorithm for computing the convex hull of a simple polygon is proposed in this paper,which is then extended to a new algorithm for computing the convex hull of a planar point set. First,the extreme points of the planar point set are found,and the subsets of point candidate for vertex of the convex hull between extreme points are obtained. Then,the ordered convex hull point sequences between extreme points are constructed separately and concatenated by removing redundant extreme points to get the convex hull. The time complexity of the new planar convex hull algorithm is O(nlogh) ,which is equal to the time complexity of the best output-sensitive planar convex hull algorithms. Compared with the algorithm having the same complexity,the new algorithm is much faster.展开更多
The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test r...The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test results indicate that DLZ is the selective collector of chalcopyrite.Especially,the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems,while the recovery of pyrite is less than 10%.When using CaO as pH regulator,at pH=7-11,the floatability of pyrite is depressed and the recovery is less than 5%.Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ,confirming that collector DLZ shows selectivity to chalcopyrite and pyrite.And FTIR results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.展开更多
We investigate the relation between distributional chaos and minimal sets,and discuss how to obtain various distributionally scrambled sets by using least and simplest minimal sets.We show:i)an uncountable extremal di...We investigate the relation between distributional chaos and minimal sets,and discuss how to obtain various distributionally scrambled sets by using least and simplest minimal sets.We show:i)an uncountable extremal distributionally scrambled set can appear in a system with just one simple minimal set:a periodic orbit with period 2;ii)an uncountable dense invariant distributionally scrambled set can occur in a system with just two minimal sets:a fixed point and an infinite minimal set;iii)infinitely many minimal sets are necessary to generate a uniform invariant distributionally scrambled set,and an uncountable dense extremal invariant distributionally scrambled set can be constructed by using just countably infinitely many periodic orbits.展开更多
This paper studies the limit set of multi-agent system with finite states, in which the system is converted into a linear system through an expansion of space. Then, the structure properties of the system matrix are i...This paper studies the limit set of multi-agent system with finite states, in which the system is converted into a linear system through an expansion of space. Then, the structure properties of the system matrix are investigated, and the relationships between the eigenvalues and the limit set are developed. As an application, the nilpotent problem of elementary cellular automata(ECA) known as algorithmically undecidable is considered, and all the nilpotent ECA are found out which consists of rules 0, 8, 64, 239, 253, 255.展开更多
基金Project (No. 2004AA420100) supported by the National Hi-TechResearch and Development Program (863) of China
文摘When the edges of a convex polygon are traversed along one direction,the interior of the convex polygon is always on the same side of the edges. Based on this characteristic of convex polygons,a new algorithm for computing the convex hull of a simple polygon is proposed in this paper,which is then extended to a new algorithm for computing the convex hull of a planar point set. First,the extreme points of the planar point set are found,and the subsets of point candidate for vertex of the convex hull between extreme points are obtained. Then,the ordered convex hull point sequences between extreme points are constructed separately and concatenated by removing redundant extreme points to get the convex hull. The time complexity of the new planar convex hull algorithm is O(nlogh) ,which is equal to the time complexity of the best output-sensitive planar convex hull algorithms. Compared with the algorithm having the same complexity,the new algorithm is much faster.
基金Project(50674102) supported by the National Natural Science Foundation of China
文摘The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test results indicate that DLZ is the selective collector of chalcopyrite.Especially,the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems,while the recovery of pyrite is less than 10%.When using CaO as pH regulator,at pH=7-11,the floatability of pyrite is depressed and the recovery is less than 5%.Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ,confirming that collector DLZ shows selectivity to chalcopyrite and pyrite.And FTIR results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.
基金supported by the Independent Research Foundation of the Central Universities(Grant No.DC 12010111)National Natural Science Foundation of China(Grant No.11271061)
文摘We investigate the relation between distributional chaos and minimal sets,and discuss how to obtain various distributionally scrambled sets by using least and simplest minimal sets.We show:i)an uncountable extremal distributionally scrambled set can appear in a system with just one simple minimal set:a periodic orbit with period 2;ii)an uncountable dense invariant distributionally scrambled set can occur in a system with just two minimal sets:a fixed point and an infinite minimal set;iii)infinitely many minimal sets are necessary to generate a uniform invariant distributionally scrambled set,and an uncountable dense extremal invariant distributionally scrambled set can be constructed by using just countably infinitely many periodic orbits.
基金supported by the National Natural Science Foundation of China under Grant Nos.61473189,61374176,61203142 and 61203073a Doctoral Program of High Education of China under Grant No.20110073120027partly by the Excellent Young Technology Innovation Foundation of Hebei University of Technology under Grant No.2012005
文摘This paper studies the limit set of multi-agent system with finite states, in which the system is converted into a linear system through an expansion of space. Then, the structure properties of the system matrix are investigated, and the relationships between the eigenvalues and the limit set are developed. As an application, the nilpotent problem of elementary cellular automata(ECA) known as algorithmically undecidable is considered, and all the nilpotent ECA are found out which consists of rules 0, 8, 64, 239, 253, 255.
