有关交簇超图的两个结论

本文结合超图中著名的EKR定理,充分利用补超图这一有力工具,论证了在限定条件下交簇超图的两个结论,从而推广了EKR定理。

线性交簇超图边数的上界

H是线性交簇超图,|E∩F|=1(E、F∈H),记s=s(H)=min|E|,A={E∈H:|E|=s}.若|A|<s2+1,则m(H)≤Δ([H]2)+1;若|A|≥s2+1,则当s≤2时,m(H)≤Δ([H]2)+1;当s≥3时,m(H)≤Δ([H]2)-2s.

一种适用于Ad hoc网络的交叠分簇路由算法

提出一种交叠分簇动态路由算法。新算法对现有分簇算法进行了两点改进。首先允许节点可以对多个分簇广播进行应答,从而将非交叠分簇改变为交叠分簇,网络拓扑也由树状结构变为纵向网状结构。其次允许同层的节点之间交换路由信息并建立路由,从而进一步增加了可选路径的条数。新算法克服了非交叠分簇算法只能得到一条最短路径的局限性,可同时得到多条可用路径。

一类由交织方式构造的二元ZCZ序列簇

2000年,Tang,Fan和Matsufuji给出(L,M,Zcz)-ZCZ序列簇的理论界为Zcz≤L/M-1。给定正整数n和L,本文给出一个交织ZCZ序列簇的构造算法,该算法由L条周期为L的正交序列簇生成一类(2n+1L,2L,2n-1)-ZCZ序列簇。若n≥2且4|τ,该类ZCZ序列簇中编号为奇数的序列与编号为偶数的序列在移位为τ时相关值为零。此外,选择不同的正交序列簇或不同的移位序列,经构造算法可以生成不同的ZCZ序列簇。

面向无线自组网的交叠分簇网络结构及性能分析

无线自组网常常采用分簇网络结构来改善网络性能,并且大都是非交叠分簇结构。首先,比较了交叠分簇结构和非交叠分簇结构的优缺点。然后,重点对交叠分簇网络结构的特性进行了研究,特别考虑了相邻簇之间的高效通信问题。最后,通过模拟实验分析了交叠分簇策略下几种典型分簇算法的性能,验证了算法的有效性。

正交图形簇畸变的校正研究及计算机仿真处理

论述了电子束扫描正交图形簇产生畸变的非线性校正过程。通过几种典型的图形分析研究 ,推导出有关的校正函数 ,并运用计算机进行了该畸变图形的仿真处理及验证。

正交多项式簇拟合水位流量关系曲线

正交多项式簇拟合水位流量关系曲线,其系数 b_j 和多项式 P_j(h)的计算过程可以逐阶相继地往高阶进行。也就是说,如果已拟合到第 j 阶多项式,若想再增加1阶,则只要在已拟合的 j 阶多项式的基础上再作第 j+1阶系数 b_(j+1)和多项式 P_(j+1)(h)的计算,而不必改变 j 阶以前的计算,这种计算的相继性使得改变拟合阶数很方便。另外,在求得正规方程时,根据多项式正交性质将矩阵(H^T)H 变换成一个对角矩阵,这样便将统计运算变成了代数运算,使得计算变得很简单。经石堤、红花岭、邹家滩、河溪4个测站资料的检验,拟合精度均能达到实用的精度。

一种基于异层交叠分簇组网的低压电力线蚁群路由方法

针对蚁群算法应用于低压电力线通信(LVPLC)领域存在收敛速度慢、容易陷入局部最优等问题,提出一种基于异层交叠分簇组网的低压电力线蚁群路由方法。该方法先通过异层交叠分簇算法进行组网,将网络节点分为多个逻辑层,并消除同一逻辑层内节点之间的通信,减少搜寻最优路径的迭代次数,优化了网络结构,然后应用蚁群算法进行路径寻优,建立网关节点与网络内任意节点的最优通信路径。仿真结果表明,相比基本蚁群算法及基于分簇蛛网组网的蚁群算法,该方法不仅大幅度提高了蚁群算法收敛速度,而且优化了路由的寻优结果,具有一定的实际意义。

完全交代数簇的陈类

代数簇的陈省身类不等式研究(也称为代数簇的地理学问题)是代数几何中的一个重要研究课题,其中重要的不等式包括著名的Miyaoka-Yau不等式和Noether不等式等.主要研究完全交代数簇的陈类不等式,通过余切丛的正合列计算得到完全交代数簇陈类的公式,具体给出了四维完全交代数簇的陈类计算公式,并建立了四维完全交代数簇陈类的一些不等式.

有关简单交超图的几个性质

文章将有关交簇的横贯超图的一个结果的证明进行了改进并讨论横贯超图有关的其它性质。

首都圈及邻近区域地震活动能量场研究

通过对首都圈及邻近区域的地震资料采用自然正交簇解析方法,分析了中强以上地震前地震活动能量时间因子和能量空间分布异常情况,发现自然正交簇解析的方法能够较好地提取中强震前的地震异常信息,虽然有些异常规律并不十分明显,其物理机制也不是十分明确,但是该方法还是一种有效的、值得探索的地震预测方法。

超图的一些简单性质讨论

文章讨论了一些关于Lovasz超图及其补图的简单性质,给出了相关证明,并在文章的最后提出了一些问题.

低压电力线载波抄表系统路由算法研究

本文提出了一种基于交叠分簇的动态路由算法,以实现低压电力线载波抄表系统中的数据通信。该算法采用分簇的基本思想将低压电力线网络进行交叠分簇得到多条最短路径;进一步规定同层节点可以相互通信,将树状拓扑结构转化为网状拓扑,增加可选路径;建立一张矩阵式路由表记录这些路径信息,在通信时查询这张路由表选取路径。该算法建立多条可选路径,克服了路径唯一的缺点,从而避免通信时发生过多的网络重构。

Microdissection of Haynaldia villosa Telosome 6VS and Cloning of Species-specific DNA Sequences

The material T240_6 derived from SC 2 young embryo of the combination CA9211/RW15 (6D/6V alien substitution) was telosomic substitution line of 6VS identified by GISH (genomic in situ hybridization) analysis. The 6VS was microdissected with a needle and transferred into a 0.5 mL Ep tube. In the 'single tube', all the subsequence steps were conducted. After two round of LA (Linker adaptor)_PCR amplification, the size of PCR bands ranged from 100 to 3 000 bp, with predominate bands 600-1 500 bp. The products were confirmed by Southern blotting analysis using Haynaldia villosa (L.) Schur. genomic DNA labeled with 32 P as probe. The PCR products were purified and ligated into clone vector-pGEM_T easy vector. Then, the plasmids were transformed into competence E. coli JM109 with cool CaCl 2. It was estimated that there were more than 17 000 white clones in the library. The size of insert fragments distributed from 100-1 500 bp, with average of 600 bp. Using H. villosa genomic DNA as probe, dot blotting results showed that 37% clones displayed strong and medium positive signals, and 63% clones had faint or no signals. It is demonstrated that there were about 37% repeat sequence clones and 67% single/unique sequence clones in the library. Eight H. villosa_specific clones were screened from the library, and two clones pHVMK22 and pHVMK134 were used for RFLP analysis and sequencing. Both of them were H. villosa specific clones. The pHVMK22 was a unique sequence clone, and the pHVMK134 was a repeat sequence clone. When the pHVMK22 was used as a probe for Southern hybridization, all the powdery mildew resistance materials showed a special band of 2 kb, while all the susceptible ones not. The pHVMK22 may be applied to detect the existence of Pm21.

基于片段融合的医学图像光线投影体绘制技术

光线投影算法是医学图像三维可视化中常用的体绘制技术,算法原理简单,具有较高的成像质量,但绘制速度较慢。我们改进算法,利用投射光线与平面簇求交,快速确定融合片段,减少插值计算量,采用基于片段的融合绘制技术,加快融合速度,并且利用包围盒技术减少对无效平面的求交,提高了光线投影的效率。实验结果表明,改进后的算法既能保证绘制质量,又能显著减少计算量,提高体绘制的速度。

一种高效的低压电力线通信组网算法设计

为了满足低压电力线网络的自适应性、时效性需求,在分析了电力线网络信道特点及拓扑结构后,指出了侦听一个时间片循环以优选最短路径的思路,提出了一套基于时分复用信道接入机制的自适应组网算法,给出了算法网络层协议及对应状态机,并使用Matlab建立了一系列仿真模拟机制及节点模型,以仿真电力线网络上实时数据流信息和组网结果。仿真结果表明,相比近年来的分簇算法,该算法在组网时间、平均通信长度和平均通信跳数方面都有明显优化,能在组网时效性和网络性能方面取得平衡。

Composition Dependent Magnetic Coupling in Fe-Cr Alloy Cluster Arrays

Dense arrays of Fe-Cr alloy clusters with different Cr ratios were fabricated by gas-phase cluster beam deposition. The complex multiphase structure and various coupling effects in the cluster arrays were studied. A lattice mismatched tetragonal-like morphology of the Fe-Cr alloy cluster was observed at large Cr ratio. An exchange bias effect was observed and was shown to be dependent on the proportion of the Cr components in the alloy. With the increase of the Cr composition, the exchange bias field became smaller and stronger dipolar interactions between the clusters developed. Residual coercivity and magnetization, which were more remarkable in the tetragonal-like clusters, were observed above the ferromagnetic-superparamagnetic transition temperature. The experimental results of the coercive field and the bias field at different temperatures demonstrated that the tetragonal-like clusters had better thermal stability and greater anisotropy.

Cluster-Based Content Download and Forwarding Scheme for Highway VANETs

The recent advances in wireless communication technology enable high-speed vehicles to download data from roadside units(RSUs). However, the data download volume of individual vehicle is rather restricted due to high mobility and limited transmission range of vehicles, bringing users poor performance. To address this issue, we exploit the combination of both clustering and carry-and-forward schemes in this paper. Our scheme coordinates the cooperation of multiple infrastructures, cluster formation in the same direction and data forwarding of reverse vehicles to facilitate the target vehicle to download large-size content in dark areas. The process of data dissemination and achievable data download volume are then derived and analyzed theoretically. Finally, we conduct extensive simulations to verify the performance of the proposed scheme. Results show significant benefits of the proposed scheme in terms of increasing data download volume and throughput.

Design of next-generation cross-linking structure for elastomers toward green process and a real recycling loop

Currently adopted cross-linking methods in rubber industry are suffering from variable persistent issues, including the utilization of toxic curing packages, release of volatile organic compounds (VOCs) and difficulties in the recycling of end-of-life materials. It is of great importance to explore a green cross-linking strategy in the area. Herein, we report a new ‘‘green" strategy based on hydrolyzable ester cross-links for cross-linking diene-typed elastomers. As a proof of concept, a commercial carboxylated nitrile rubber (XNBR) is efficiently cross-linked by a bio-based agent, epoxidized soybean oil (ESO), without any toxic additives. ESO exhibits an excellent plasticization effect and excellent scorch safety for XNBR. The crosslinking density and mechanical properties of the ESO-cured XNBR can be manipulated in a wide range by changing simply varying the content of ESO. In addition, zinc oxide (Zn O) performs as a catalyst to accelerate the epoxide opening reaction and improve the cross-linking efficiency, serving as reinforcement points to enhance the overall mechanical properties of the ESO-cured XNBR. Furthermore, the end-oflife elastomer materials demonstrate a closed-loop recovery by selectively cleaving the ester bonds, resulting in very high recovery of the mechanical performance of the recycled composites. This strategy provides an unprecedented green avenue to cross-link diene elastomers and a cost-effective approach to further recycle the obtained cross-linked elastomers at high efficiency.

An improvement of Chen-Ru-Yan's degenerated second main theorem

We give an improvement for the second main theorem of algebraically non-degenerate holomorphic curves into a complex projective variety V intersecting hypersurfaces in subgeneral position, obtained by Chen et al.(2012). An explicit estimate for the truncation level is also obtained in the projective normal case.