图的k-星着色的Grbner基求解

对于具有n个顶点的简单连通图G,首先证明求解G的k-星着色等价于一个多元多项式方程组在{1,2,…,k}上的求解问题,其次使用Grbner基给出求解该多元多项式方程组的方法,从而得到求G的星色数的一个可行途径,最后通过实例验证了此代数计算方法的有效性.     

I ain’t afraid of no ghost

This paper criticizes the traditional philosophical account of the quantization of gauge theories and offers an alternative. On the received view, gauge theories resist quantization because they feature distinct mathematical representatives of the same physical state of affairs. This resistance is overcome by a sequence of ad hoc modifications, justified in part by reference to semiclassical electrodynamics. Among other things, these modifications introduce ”ghosts”: particles with unphysical properties which do not appear in asymptotic states and which are said to be purely a notational convenience. I argue that this sequence of modifications is unjustified and inadequate, making it a poor basis for the interpretation of ghosts. I then argue that gauge theories can be quantized by the same method as any other theory. On this account, ghosts are not purely notation: they are coordinates on the classical configuration space of the theory—specifically, on its gauge structure. This interpretation does not fall prey to the standard philosophical arguments against the significance of ghosts, due to Weingard. Weingard’s argumentative strategy, properly applied, in fact tells in favor of ghosts’ physical significance.     

高应力作用下不同颗粒特征的钙质砂压缩破碎特性

对南海不同岛礁处的钙质砂开展一系列终止压力为8MPa的高压固结试验，研究不同颗粒形貌及不同粒组的钙质砂的颗粒破碎演化规律。试验结果表明，两种钙质砂试样S₁和S₂的矿物组分基本相同，但不同的沉积环境造成了颗粒形状具有显著差异；以片状颗粒为主的钙质砂试样S₂的压缩性和颗粒破碎程度会显著高于以块状颗粒为主的钙质砂试样S₁，且颗粒相对破碎率B_r均随着颗粒粒径的增大而增大；对两种不同的钙质砂而言，相对破碎率B_r与压缩变形量之间呈良好的幂函数递增关系，表明颗粒破碎大小与压缩变形量密切相关。     

Variation in ovariole number within the Aphidoidea

Several different morphs from over 50 species of aphids were dissected and the number of ovarioles recorded for each. By using these results and published data, details of ovariole number in more than 125 species of aphid from seven families were analysed.

Variation in ovariole number between generations was found in six of the seven families studied. Variation within a generation appeared to be restricted to certain subfamilies.

Certain trends in variability of ovariole number appear to be linked with the morph of the aphid, migratory morphs (particularly within the Aphididae) having greater variability than non-migratory morphs. Heteroecious aphids tend to show greater variability than autoecious aphids which, in turn, show greater variability than anholocyclic aphids.     

完全模糊线性规划及其近似计算

在扩充LR-模糊数定义的基础上,讨论了完全模糊约束条件的近似表示和转化定理;在新的模糊数序关系下,将完全模糊线性规划问题直接转化为分明的线性规划进行求解;与已有的结果进行了比较,并给出了算例.     

模糊随机过程的Itô-Henstock积分

定义和讨论了适应的模糊随机过程关于Brownian运动的模糊Itô-Henstock积分和模糊Itô-McShane积分及其性质,给出了刻画定理,并讨论了两者之间的相互关系。结果表明,当模糊Itô-Henstock积分原函数Itô 绝对连续时,模糊Itô-Henstock积分和模糊Itô-McShane积分等价。     

基于PFC 2D的含节理岩体单轴压缩数值模拟

基于颗粒流方法模拟含节理岩体的单轴压缩破坏过程,并对不同节理倾角的岩体进行单轴压缩数值模拟,研究不同节理倾角岩体的裂纹扩展路径、破坏形式以及强度变化规律。结果表明:(1)在单轴压缩破坏过程中,岩体节理倾角不同,裂纹扩展与最终破坏形态不同,但破坏过程基本一致;(2)当节理倾角从0°到90°的变化过程中,抗压强度随节理倾角的增大先减小后增加,总体呈"U"型分布规律,并在倾角为60°时达最小值。     

基于投资犹豫的欧式期权定价模型

文章首先引入三角直觉模糊数来刻画投资者的犹豫程度和期权价格估计的不确定性,构建了基于三角直觉模糊数的Black-Scholes期权定价模型,并用风险中性的方法给出了欧式期权价格的解析表达式,该结论是Yoshida更一般的情况.然后,本文进行了数值分析,给出了欧式期权价格的区间值,并进行了参数敏感性分析.研究结果表明:基于三角直觉模糊数的Black-Scholes期权定价模型更能体现投资者的犹豫程度.     

珊瑚礁算法的改进研究

珊瑚礁算法易于陷入局部最优且寻优精度低，因此提出一种改进的珊瑚礁算法.此算法借鉴粒子群算法、高斯变异和模拟退火算法的思想改进珊瑚礁算法的内部有性繁殖、无性繁殖和更替机制，提高了算法的寻优精度并可跳出局部最优.在仿真实验中，将改进珊瑚礁算法与基本珊瑚礁算法和粒子群算法等10种算法分别在高维和低维测试函数下进行比较.实验结果表明，改进的珊瑚礁算法不仅较其他算法具有更好的收敛速度和精度，而且在高维测试函数中，仍然可以保持良好的性能.     

Signal Diffusion Mapping: Optimal Forecasting with Time‐Varying Lags

We introduce a new methodology for forecasting, which we call signal diffusion mapping. Our approach accommodates features of real‐world financial data which have been ignored historically in existing forecasting methodologies. Our method builds upon well‐established and accepted methods from other areas of statistical analysis. We develop and adapt those models for use in forecasting. We also present tests of our model on data in which we demonstrate the efficacy of our approach. Copyright © 2015 John Wiley & Sons, Ltd.