Resonant transmission in three-terminal triangle graphene nanojunctions with zigzag edges

Three-terminal nanojunctions based on triangle zigzag edged graphene flakes are proposed and their transport properties are studied. In the solid and hollow triangle graphene junctions, there exist different resonant transmissions due to the different electronic states in the two structures. The quasi-bound states in the solid junction are confined in the inner of the triangle flake, while those in the hollow junction are confined at the zigzag edges. In addition, these states are tightly associated with the size of the triangle flake, thus the resonant transmissions in the triangle graphene junctions can be tuned by the structural size and geometry.     

Proper connection number of bipartite graphs

An edge-colored graph G is proper connected if every pair of vertices is connected by a proper path. The proper connection number of a connected graph G, denoted by pc(G), is the smallest number of colors that are needed to color the edges of G in order to make it proper connected. In this paper, we obtain the sharp upper bound for pc(G) of a general bipartite graph G and a series of extremal graphs. Additionally, we give a proper 2-coloring for a connected bipartite graph G having δ(G) ≥ 2 and a dominating cycle or a dominating complete bipartite subgraph, which implies pc(G) = 2. Furthermore, we get that the proper connection number of connected bipartite graphs with δ ≥ 2 and diam(G) ≤ 4 is two.     

二元函数四条性质之间的关系

二元函数的连续性,偏导数存在性,偏导数连续性以及可微性是二元函数的四条经典性质,它们之间的关系一直是学生的疑惑点,本文结合严格的证明和典型的反例给出四条性质之间关系的详尽阐释.     

On the number of inequivalent Gabidulin codes

Maximum rank-distance (MRD) codes are extremal codes in the space of \(m\times n\) matrices over a finite field, equipped with the rank metric. Up to generalizations, the classical examples of such codes were constructed in the 1970s and are today known as Gabidulin codes. Motivated by several recent approaches to construct MRD codes that are inequivalent to Gabidulin codes, we study the equivalence issue for Gabidulin codes themselves. This shows in particular that the family of Gabidulin codes already contains a huge subset of MRD codes that are pairwise inequivalent, provided that \(2\leqslant m\leqslant n-2\).     

fastWKendall: an efficient algorithm for weighted Kendall correlation

The Kendall correlation is a non-parametric method that measures the strength of dependence between two sequences. Like Pearson correlation and Spearman correlation, Kendall correlation is widely applied in sequence similarity measurements and cluster analysis. We propose an efficient algorithm, fastWKendall, to compute the approximate weighted Kendall correlation in \(O(n\log n)\) time and O(n) space complexity. This is an improvement to the state-of-the-art \(O(n^2)\) time requirement. The proposed method can be incorporated to perform conventional sequential similarity measurement and cluster analysis much more rapidly. This is important for analysis of huge-volume datasets, such as genome databases, streaming stock market data, and publicly available huge datasets on the Internet. The code which is implemented in R is available for public access.     

基于支持向量回归的豆油期货数据分析

随着期货市场在经济中的影响逐渐增强,对期货市场的研究具有实际意义.选取豆油期货指数进行研究,首先将数据进行归一化处理,然后选用支持向量回归方法建模分析.分析结果表明该方法对短期内的数据预测具有较好的效果,对了解期货市场的近期走势提供一些借鉴.     

区域创新系统协同演化机制与优化设计研究

为揭示区域创新系统协同演化机制的本质与规律,在对区域创新系统自组织特征予以描述的基础上,构建区域创新系统协同演化的哈肯模型,选用基础共性技术创新数据与制度创新数据进行实证研究,运用Minitab软件设计系统演化方案并提出优化对策。研究结果表明:基础共性技术创新代表量是区域创新系统动态演化的序参量;基础共性技术创新与制度创新在区域创新系统演化过程中具有协同效应,但协同度欠佳;制度创新递增的正反馈机制在区域创新系统演化过程中的信噪比最大,基础共性技术创新对制度创新推动作用的反映最灵敏;当信噪比最大的参数λ₂<0,形成制度创新递增的正反馈机制,同时调控参数使得a、b、λ₁均小于0且尽量保持a的绝对值最大,区域创新系统将会实现最优演化水平。     

基于员工行为差异的元胞自动机演化模拟与机制设计

提出了企业员工的正行为、零行为和负行为概念,分析了员工中不同行为间的相互影响.对传统元胞自动机方法进行了改进,建立了基于员工传播性和保持性的元胞自动机模型,并对员工不同的初始比例、不同的行为传播性和保持性以及企业不同奖励和惩罚性政策下的员工行为演化进行了模拟,得到了一些合理和有益的结论,并对不同情形下的人员管理提供了针对性建议.     

城市交通疏导的优化算法及应用研究

城市交通是一个随机性很强、复杂的系统.影响城市交通顺畅的因素很多,针对目前交通存在的问题,由具体实例到抽象特性,从城市局部到整体进行了研究分析.在现有硬件设施的基础上,采用最优化算法,对比现有算法存在的缺点提出新的优化策略,便于智能交通管理.