The general concepts in message queuing and message-oriented middleware(MOM) are discussed. The essential elements and model of the queuing theory are analyzed in detail. Then, after puting forward and analyzing the b...The general concepts in message queuing and message-oriented middleware(MOM) are discussed. The essential elements and model of the queuing theory are analyzed in detail. Then, after puting forward and analyzing the basic formulas of the queuing theory, the applicable model for message queue middleware is probed into. Some important formulas used in the designing of the message queue middleware are also elucidated. Finally, a case of designing the message queue middleware adopting queuing model we put forward, which is used in the freeway toll system of ITS, is studied.展开更多
When calculating electromagnetic scattering using method of moments (MoM), integral of the singular term has a significant influence on the results. This paper transforms the singular surface integral to the contour...When calculating electromagnetic scattering using method of moments (MoM), integral of the singular term has a significant influence on the results. This paper transforms the singular surface integral to the contour integral. The integrand is expanded to Taylor series and the integral results in a closed form. The cut-off error is analyzed to show that the series converges fast and only about 2 terms can agree wel with the accurate result. The comparison of the perfect electric conductive (PEC) sphere's bi-static radar cross section (RCS) using MoM and the accurate method validates the feasibility in manipulating the singularity. The error due to the facet size and the cut-off terms of the series are analyzed in examples.展开更多
文摘The general concepts in message queuing and message-oriented middleware(MOM) are discussed. The essential elements and model of the queuing theory are analyzed in detail. Then, after puting forward and analyzing the basic formulas of the queuing theory, the applicable model for message queue middleware is probed into. Some important formulas used in the designing of the message queue middleware are also elucidated. Finally, a case of designing the message queue middleware adopting queuing model we put forward, which is used in the freeway toll system of ITS, is studied.
基金supported by the National Natural Science Foundationof China for the Youth(51307004)
文摘When calculating electromagnetic scattering using method of moments (MoM), integral of the singular term has a significant influence on the results. This paper transforms the singular surface integral to the contour integral. The integrand is expanded to Taylor series and the integral results in a closed form. The cut-off error is analyzed to show that the series converges fast and only about 2 terms can agree wel with the accurate result. The comparison of the perfect electric conductive (PEC) sphere's bi-static radar cross section (RCS) using MoM and the accurate method validates the feasibility in manipulating the singularity. The error due to the facet size and the cut-off terms of the series are analyzed in examples.