This note shows that when studying geometric pro perties, a polynomial system is defined as a line field on a projective space such that its singular set has co dimension at least 2. By this definition, the concept ...This note shows that when studying geometric pro perties, a polynomial system is defined as a line field on a projective space such that its singular set has co dimension at least 2. By this definition, the concept of the degree of a polynomial system does not coincide with the usual one. The usual degenerate polynomial system of degree n+1 should be regarded as a system of degree n . Note that the definition is independent coordinate system. And, by this definition, some geometric properties concerning polynomial vector fields turn out to be evident.展开更多
A family of authentication codes with arbitration is constructed from unitary geometry,the parameters and the probabilities of deceptions of the codes are also computed.In a special case a perfect authentication code ...A family of authentication codes with arbitration is constructed from unitary geometry,the parameters and the probabilities of deceptions of the codes are also computed.In a special case a perfect authentication code with arbitration is obtained.展开更多
When we turn from plane to solid geometry,we turn from the flat two-dimensional world sheet of paper or a TV screen to the rich three-dimensional world of everyday life.
This paper considers an efficient priority service model with two-level-polling scheme which the message packets conform to the discrete-time Geom/G/1 queue with multiple vacations and bulk arrival. By the embedded Ma...This paper considers an efficient priority service model with two-level-polling scheme which the message packets conform to the discrete-time Geom/G/1 queue with multiple vacations and bulk arrival. By the embedded Markov chain theory and the probability generating function method, we set up the mathematics functions and give closed form expressions for obtaining the mean cyclic period （MCP）, the mean queue length （MQL） and the mean waiting time （MWT） characteristics, the analytical results are also verified through extensive computer simulations. The performance analysis reveals that this priority polling scheme can gives better efficiency as well as impartiality in terms of system characteristics, and it can be used for differentiating priority service to guarantee better QoS and system stability in design and improvement of MAC protocol.展开更多
The transientbehaviorofisotropic and hom ogeneousplateshasbeen a subjectofinterest. Thepresentinvestigation isconcerned w ith the largedeflection transientanalysisand controlofplates w ith piezoelectricsensorsand ac...The transientbehaviorofisotropic and hom ogeneousplateshasbeen a subjectofinterest. Thepresentinvestigation isconcerned w ith the largedeflection transientanalysisand controlofplates w ith piezoelectricsensorsand actuatorsunderapplied transverse loads. In this paper, the increm ental finite elem entequationsconsidering thegeom etricnonlinearity ofpiezoelectricsm artstructuresarede- veloped based on TotalLagrange approach by using the virtualvelocity increm entalvariationalprinci- ples. A four-node Mindlin plate elem ent w ith reduced and selective integration is adopted. The re- sulting increm entequationsare solved by using New m ark'sdirectintegration approach. Transientre- sponse ofplatesw ith piezoelectricsensorsand actuators subjected to transverse dynam ic loading isin- vestigated. The active dam ping isintroduced on the platesby coupling a negativevelocity feedback al- gorithm in a closed controlloop. The num ericalresults show thatpiezoelectric actuators can produce significant dam ping and suppress transient vibration effectively. Finally, the effects of the num ber and locations ofthe piezoelectric actuatorson the controlsystem are also investigated.展开更多
文摘This note shows that when studying geometric pro perties, a polynomial system is defined as a line field on a projective space such that its singular set has co dimension at least 2. By this definition, the concept of the degree of a polynomial system does not coincide with the usual one. The usual degenerate polynomial system of degree n+1 should be regarded as a system of degree n . Note that the definition is independent coordinate system. And, by this definition, some geometric properties concerning polynomial vector fields turn out to be evident.
文摘A family of authentication codes with arbitration is constructed from unitary geometry,the parameters and the probabilities of deceptions of the codes are also computed.In a special case a perfect authentication code with arbitration is obtained.
文摘When we turn from plane to solid geometry,we turn from the flat two-dimensional world sheet of paper or a TV screen to the rich three-dimensional world of everyday life.
基金Supported by the National Natural Science Foundation of China （No. 69862001, F0424104, 60362001 and 61072079）.
文摘This paper considers an efficient priority service model with two-level-polling scheme which the message packets conform to the discrete-time Geom/G/1 queue with multiple vacations and bulk arrival. By the embedded Markov chain theory and the probability generating function method, we set up the mathematics functions and give closed form expressions for obtaining the mean cyclic period （MCP）, the mean queue length （MQL） and the mean waiting time （MWT） characteristics, the analytical results are also verified through extensive computer simulations. The performance analysis reveals that this priority polling scheme can gives better efficiency as well as impartiality in terms of system characteristics, and it can be used for differentiating priority service to guarantee better QoS and system stability in design and improvement of MAC protocol.
文摘The transientbehaviorofisotropic and hom ogeneousplateshasbeen a subjectofinterest. Thepresentinvestigation isconcerned w ith the largedeflection transientanalysisand controlofplates w ith piezoelectricsensorsand actuatorsunderapplied transverse loads. In this paper, the increm ental finite elem entequationsconsidering thegeom etricnonlinearity ofpiezoelectricsm artstructuresarede- veloped based on TotalLagrange approach by using the virtualvelocity increm entalvariationalprinci- ples. A four-node Mindlin plate elem ent w ith reduced and selective integration is adopted. The re- sulting increm entequationsare solved by using New m ark'sdirectintegration approach. Transientre- sponse ofplatesw ith piezoelectricsensorsand actuators subjected to transverse dynam ic loading isin- vestigated. The active dam ping isintroduced on the platesby coupling a negativevelocity feedback al- gorithm in a closed controlloop. The num ericalresults show thatpiezoelectric actuators can produce significant dam ping and suppress transient vibration effectively. Finally, the effects of the num ber and locations ofthe piezoelectric actuatorson the controlsystem are also investigated.
