检索结果-南通市图书馆

Determination of the packing number D_λ(3,W_4^((3)),v)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2009年第11期52卷 2537-2548页

作者： WU Yan & CHANG YanXun Institute of Mathematics,beijing jiaotong university,beijing 100044,China Institute of Mathematics Beijing Jiaotong University Beijing China

A t-hyperwheel(t≥3) of length l(or W l(t) for brevity) is a t-uniform hypergraph(V,E) ,where E = {e1,e2,. . .,el} and v1,v2,. . .,vl are distinct vertices of V = il=1 ei such that for i = 1,. . .,l,vi,vi+1 ∈ ei and ei ∩ ej = P,j ∈/{i-1,i,i + 1},where the operation on the subscripts is modulo l and P is a vertex of V which is different from vi,1 i l. In this paper,we investigate the maximum packing problem of MPλ(3,W 4( 3) ,v) . Finally,the packing number Dλ(3,W 4( 3) ,v) is determined for any positive integers v 5 and λ.

关键词： t-(v Γ λ) packing leave packing number group divisible(Γ t) -design candelabra(Γ t) -system

The spectrum of （gv, g, 3, λ）-DF in Zgv

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Mathematics 2009年第5期52卷 1004-1016页

作者： WANG XiaoMiao & CHANG YanXun Institute of Mathematics, beijing jiaotong university, beijing 100044, China Institute of Mathematics Beijing Jiaotong University Beijing China

In this paper, the necessary and sufficient conditions for the existence of a (gv, g, 3, λ)- difference family in Zgv are established. As a consequence, the existence spectrum of a cyclic (3, λ)-GDD of type gv witho... 详细信息

关键词： difference family incomplete difference matrix perfect difference family

ON THE SINGLE SERVER RETRIAL QUEUE WITH PRIORITY SUBSCRIBERS AND SERVER BREAKDOWNS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2008年第2期21卷 304-315页

作者： Jinting WANG Department of Mathematics Beijing Jiaotong University Beijing 100044 China

The author concerned the reliability evaluation as well as queueing analysis of M1, M2/G1, G2/1 retrial queues with two different types of primary customers arriving according to independent Poisson flows. In the case of blocking, the first type of customers can be queued whereas the second type of customers must leave the service area but return after some random period of time to try their luck again. The author assumes that the server is unreliable and it has a service-type dependent, exponentially distributed life time as well as a service-type dependent, generally distributed repair time. The necessary and sufficient condition for the system to be stable is investigated. Using a supplementary variable method, the author obtains a steady-state solution for queueing measures, and the transient as well as the steady-state solutions for reliability measures of interest.

关键词： Priority queues reliability retrial queues server breakdowns.

THE EFFECTS OF BOUNDARY TO THE ECRH AND THE ENERGY ABSORPTION OF ICRH

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 1987年第4期3卷 315-325页

作者： Kang Shouwan Northern jiaotong university,beijing Northern jiaotong university Beijing

Electron-cyclotron resonant heating(ECRH)of Tokamak plasma is *** plasmais heated by waves,we must consider the distribution of incident wave energy to O and X modes as the wave isincident from vacuum to the surface of plasma as well as the absorption efficiency of O mode and X *** calculation shows that for small incident angle,the incident energy transfers principally into 0mode when the electric field E of incident wave is parallel to the incident plane,therefore it is efficient to heatthe plasma by O *** E is perpendicular to the incident plane,the energy transfers principally into Xmode and heating the plasma by X mode is ***-cyclotron resonant heating(ICRH)is also considered,the formula of the energy of ion-cyclotronwave absorbed by plasma is obtained.

关键词： plasma ECRH ICRH

One-step quadratic convergence of noninterior continuation method for NCP

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第20期44卷 1858-1862页

作者： XIU NaihuaDepartment of Mathematics , Northern jiaotong university , beijing 100044, China Department of Mathematics Northern Jiaotong University Beijing China

A noninterior continuation method is presented, with only the certering step used at each iteration, for nonlinear complementarity problem. It is shown that the algorithm is globally linearly and locally quadratically... 详细信息

关键词： nonlinear complementarity problem noninterior continuation method one-step quadratic convergence.

THERMAL SHOCK OF SEMI-INFINITE BODY WITH MULTI-PULSED INTENSE LASER RADIATION

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2010年第2期23卷 175-180页

作者： Haiming Huang 1 Fang Su Yue Sun(Institute of Engineering Mechanics,beijing jiaotong university,beijing 100044,China) Institute of Engineering Mechanics Beijing Jiaotong University Beijing China

In order to investigate the thermal shock and the heat conduction property of a target under multi-pulsed laser radiation, analytic expressions of both temperature and thermal stress fields in the target are deduced on the basis of the non-Fourier conduction law and the thermo-elastic theory. Taking a stainless steel target as an example, we can solve the analytic expressions under appropriate boundary conditions by using the finite difference method and MATLAB software, and then reveal the evolution law of both surplus temperaturt, and thermal stress in the target. The results indicate that the temperature curves in the target irradiated by a multi-pulsed laser take on a delayed character in different sections away from the boundary, which is only affected by its relaxation time. The front of the stress wave is very steep in the non-Fourier numerical solutions, which presents an obvious thermal shock, so it is necessary to consider the non-Fourier effect of semi-infinite body under the high energy laser radiation.

关键词： multi-pulsed laser non-Fourier effect thermal shock

Decompositions of the 3-uniform hypergraphs K_v^(3) into hypergraphs of a certain type

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2007年第7期50卷 1035-1044页

作者： Tao FENG Yan-xun CHANG Institute of Mathematics,beijing jiaotong university,beijing 100044,China Institute of Mathematics Beijing Jiaotong University Beijing China

In this paper,we investigate a generalization of graph decomposition,called hypergraph *** show that a decomposition of a 3-uniform hypergraph K_v^(3)into a special kind of hypergraph K_4^(3)-e exists if and only if v... 详细信息

关键词： hypergraph decomposition t-GDD group divisible(Γ,t)-design candelabra(Γ,t)-system

An improved reduced-rank STAP interference suppression method in design of GNSS receivers

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2012年第10期55卷 2329-2342页

作者： GONG WenFei & SUN Xin School of Electronics and Information Engineering,beijing jiaotong university,beijing 100044,China School of Electronics and Information Engineering Beijing Jiaotong University Beijing China

In this paper,we address the problem of interference cancellation in global positioning system(GPS) receiver using an adaptive reduced-rank space-time adaptive processing(STAP) interference suppression method based on multistage nested Wiener filter(MSNWF).This improved adaptive reduced-rank method is based on the improved Gerschgorin radii ***,the cross-correlations between the desired signals of the adjacent stages of MSNWF are directly used to calculate the Gerschgorin radii instead of employing the eigenvalue decomposition of the covariance ***,a heuristic decision rule based on Gerschgorin disk estimator(GDE) is employed to estimate the rank of interference *** optimal rank can be adaptively selected without increasing the *** and results of the experiment show that the proposed method further reduces the computation of STAP and enhances its real-time property with the interference suppression performance unaffected.

关键词： global positioning system reduced-rank space-time adaptive processing multistage nested Wiener filter Gerschgorin disk estimator

Inferring playback rate and rate resets of P2P video streaming transmissions by piecewise line envelope approximation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第2期16卷 58-62,79页

作者： LI Chun-xi CHEN Chang-jia School of Electronics and Information Engineering,beijing jiaotong university,beijing 100044,China School of Electronics and Information Engineering Beijing Jiaotong University Beijing 100044 China

Conventionally, P2P video is regarded as CBR traffic. However, our measurements have shown that the rate reset cannot be neglected in a practical IPTV system because each rate reset often leads to performance degradation. Thus, addressing the problem of inferring playback rate and rate reset in a P2P video system is significant. In this article, an algorithm termed piecewise linear envelope approximation （PLEA） is proposed, in which a follow-up time is introduced to smooth rate fluctuations in a small time scale and to adapt rate jumps in a large time scale automatically. With the PLEA algorithm, discontinuity introduced by blind segmentations adopted by current methods is avoided. Furthermore, unlike existing algorithms in which both segmentation and combinations are performed in multiple runs, only a single computation path is involved in the PLEA algorithm. This makes PLEA algorithm amenable to implementation of low complexity by either software or hardware. Both theoretical analysis and experiment based on measured data show that the PLEA outperforms existing algorithms based on segmentation.

关键词： P2P video playback rate rate reset convex hull linear program