A digraph D is k-ordered if for every sequence S：v 1,v 2,…,v k of k distinct vertices,there exists a cycle C such that C encounters the vertices of S in the specified order.In particular,we say that D is k-ordered h...A digraph D is k-ordered if for every sequence S：v 1,v 2,…,v k of k distinct vertices,there exists a cycle C such that C encounters the vertices of S in the specified order.In particular,we say that D is k-ordered hamiltonian if for every sequence S：v 1,v 2,…,v k of k distinct vertices,there exists a hamiltonian cycle C such that the vertices of S are encountered on C in the specified order.In this paper,sufficient conditions for digraphs to be ordered and ordered hamiltonian have been given.展开更多
Computer system＇s runtime information is an essential part of the digital evidence. Current digital forensic approaches mainly focus on memory and I/O data, while the runtime instructions from processes are often ign...Computer system＇s runtime information is an essential part of the digital evidence. Current digital forensic approaches mainly focus on memory and I/O data, while the runtime instructions from processes are often ignored. We present a novel approach on runtime instruction forensic analysis and have developed a forensic system which collects instruction flow and extracts digital evidence. The system is based on whole-system emulation technique and analysts are allowed to define analysis strategy to improve analysis efficiency and reduce overhead. This forensic approach and system are applicable to binary code analysis, information retrieval and matware forensics.展开更多
We focus on orders in arbitrary number fields, consider their Picard groups and finally obtain ring class fields corresponding to them. The Galois group of the ring class field is isomorphic to the Picard group.As an ...We focus on orders in arbitrary number fields, consider their Picard groups and finally obtain ring class fields corresponding to them. The Galois group of the ring class field is isomorphic to the Picard group.As an application, we give criteria of the integral solvability of the diophantine equation p = x2+ ny2 over a class of imaginary quadratic fields where p is a prime element.展开更多
基金Foundation item： Supported by the National Natural Science Foundation of China（61070229） Supported by the Natural Science Foundation of Shanxi Province（2008011010）
文摘A digraph D is k-ordered if for every sequence S：v 1,v 2,…,v k of k distinct vertices,there exists a cycle C such that C encounters the vertices of S in the specified order.In particular,we say that D is k-ordered hamiltonian if for every sequence S：v 1,v 2,…,v k of k distinct vertices,there exists a hamiltonian cycle C such that the vertices of S are encountered on C in the specified order.In this paper,sufficient conditions for digraphs to be ordered and ordered hamiltonian have been given.
文摘Computer system＇s runtime information is an essential part of the digital evidence. Current digital forensic approaches mainly focus on memory and I/O data, while the runtime instructions from processes are often ignored. We present a novel approach on runtime instruction forensic analysis and have developed a forensic system which collects instruction flow and extracts digital evidence. The system is based on whole-system emulation technique and analysts are allowed to define analysis strategy to improve analysis efficiency and reduce overhead. This forensic approach and system are applicable to binary code analysis, information retrieval and matware forensics.
基金supported by National Natural Science Foundation of China(Grant No.11471314)the National Basic Research Program of China(973 Project)(Grant No.2011CB302401)the National Center for Mathematics and Interdisciplinary Sciences,Chinese Academy of Sciences
文摘We focus on orders in arbitrary number fields, consider their Picard groups and finally obtain ring class fields corresponding to them. The Galois group of the ring class field is isomorphic to the Picard group.As an application, we give criteria of the integral solvability of the diophantine equation p = x2+ ny2 over a class of imaginary quadratic fields where p is a prime element.
