A packing of the complete directed symmetric graph DK v with m circuits, denoted by ( v,m) DCP, is defined to be a family of arc disjoint m circuits of DK v such that any one arc of DK v \ occurs...A packing of the complete directed symmetric graph DK v with m circuits, denoted by ( v,m) DCP, is defined to be a family of arc disjoint m circuits of DK v such that any one arc of DK v \ occurs in at most one m circuit. The packing number P(v,m) is the maximum number of m circuits in such a packing. The packing problem is to determine the value P(v,m) for every integer v≥m. In this paper, the problem is reduced to the case m+6≤v≤2m- 4m-3+12 , for any fixed even integer m≥4 . In particular, the values of P(v,m) are completely determined for m=12 , 14 and 16.展开更多
Let DKv denote the symmetric complete directed graph with v vertices, the covering number C(v,m) is a minimum number of covering DKv by m-circuits. In this paper, C(v,m) is determined for any fixed odd positive intege...Let DKv denote the symmetric complete directed graph with v vertices, the covering number C(v,m) is a minimum number of covering DKv by m-circuits. In this paper, C(v,m) is determined for any fixed odd positive integer m and positive integer v, m ≤ v ≤ m + 6.展开更多
Taking domains in the one hand and actions of a semigroup (automaton) on the other, as two crucial notions in mathematics as well as in computer science, we consider the notion of compact directed complete poset (a...Taking domains in the one hand and actions of a semigroup (automaton) on the other, as two crucial notions in mathematics as well as in computer science, we consider the notion of compact directed complete poset (acts), and investigate the interesting notion of absolute retractness for such ordered structures. As monomorphisms and embeddings for domain acts are different notions, we study absolute retractness with respect to both the class of monomorphisms and that of embed- dings for compact directed complete poset (acts). We characterize the absolutely retract compact dcpos as complete compact chains. Also, we give some examples of compact di- rected complete poset acts which are (g-)absolutely retract (with respect to embeddings) and show that completeness is not a sufficient condition for (g-)absolute retractness.展开更多
Beam measurement is very important for accelerators. In this paper, modern digital beam measurement techniques based on I Q(In-phase & Quadrature-phase) analysis are discussed. Based on this method and highspeed hi...Beam measurement is very important for accelerators. In this paper, modern digital beam measurement techniques based on I Q(In-phase & Quadrature-phase) analysis are discussed. Based on this method and highspeed high-resolution analog-to-digital conversion, we have completed three beam measurement electronics systems designed for the China Spallation Neutron Source(CSNS), Shanghai Synchrotron Radiation Facility(SSRF), and Accelerator Driven Sub-critical system(ADS). Core techniques of hardware design and real-time system calibration are discussed, and performance test results of these three instruments are also presented.展开更多
文摘A packing of the complete directed symmetric graph DK v with m circuits, denoted by ( v,m) DCP, is defined to be a family of arc disjoint m circuits of DK v such that any one arc of DK v \ occurs in at most one m circuit. The packing number P(v,m) is the maximum number of m circuits in such a packing. The packing problem is to determine the value P(v,m) for every integer v≥m. In this paper, the problem is reduced to the case m+6≤v≤2m- 4m-3+12 , for any fixed even integer m≥4 . In particular, the values of P(v,m) are completely determined for m=12 , 14 and 16.
文摘Let DKv denote the symmetric complete directed graph with v vertices, the covering number C(v,m) is a minimum number of covering DKv by m-circuits. In this paper, C(v,m) is determined for any fixed odd positive integer m and positive integer v, m ≤ v ≤ m + 6.
文摘Taking domains in the one hand and actions of a semigroup (automaton) on the other, as two crucial notions in mathematics as well as in computer science, we consider the notion of compact directed complete poset (acts), and investigate the interesting notion of absolute retractness for such ordered structures. As monomorphisms and embeddings for domain acts are different notions, we study absolute retractness with respect to both the class of monomorphisms and that of embed- dings for compact directed complete poset (acts). We characterize the absolutely retract compact dcpos as complete compact chains. Also, we give some examples of compact di- rected complete poset acts which are (g-)absolutely retract (with respect to embeddings) and show that completeness is not a sufficient condition for (g-)absolute retractness.
基金Supported by National Natural Science Foundation of China(11205153,10875119)Knowledge Innovation Program of the Chinese Academy of Sciences(KJCX2-YW-N27)+1 种基金the Fundamental Research Funds for the Central Universities(WK2030040029)the CAS Center for Excellence in Particle Physics(CCEPP)
文摘Beam measurement is very important for accelerators. In this paper, modern digital beam measurement techniques based on I Q(In-phase & Quadrature-phase) analysis are discussed. Based on this method and highspeed high-resolution analog-to-digital conversion, we have completed three beam measurement electronics systems designed for the China Spallation Neutron Source(CSNS), Shanghai Synchrotron Radiation Facility(SSRF), and Accelerator Driven Sub-critical system(ADS). Core techniques of hardware design and real-time system calibration are discussed, and performance test results of these three instruments are also presented.