环面上Z_+~k-作用的Friedland熵的计算公式

本文对环面上Z_k~+-作用的Friedland熵进行研究.针对由两两不同的可交换非奇异整数矩阵诱导的环面上的Z_k~+-作用,运用与之相关联的斜积系统的相对变分原理和拓扑压等工具,得到Friedland熵的计算公式.     

最优(v,{3,4},1,Q)-光正交码的构造

在光纤码分多址(OCDMA)系统中,变重量光正交码被广泛使用,以满足多种服务质量的需求.利用分圆类和斜starter给出了直接构造方法,借助有关循环差阵的递归构造方法,从而构造了两类循环填充设计.通过建立循环填充设计与变重量光正交码之间的联系,证明了当Q∈{{2/3,1/3},{3/4,1/4}}时,最优(v,{3,4},1,Q)-光正交码存在的无穷类.     

Pricing VIX options in a stochastic vol‐of‐vol model

This paper proposes and makes a study of a new model for volatility index option pricing. Factors such as mean‐reversion, jumps, and stochastic volatility are taken into consideration. In particular, the positive volatility skew is addressed by the jump and the stochastic volatility of volatility. Daily calibration is used to check whether the model fits market prices and generates positive volatility skews. Overall, the results show that the mean‐reverting logarithmic jump and stochastic volatility model (called MRLRJSV in the paper) serves as the best model in all the required aspects. Copyright © 2015 John Wiley & Sons, Ltd.     

Constructions of optimal quaternary constant weight codes via group divisible designs

Generalized Steiner systems were first introduced by Etzion and used to construct optimal constant weight codes over an alphabet of size g+1 with minimum Hamming distance 2k−3, in which each codeword has length v and weight k. As to the existence of a , a lot of work has been done for k=3, while not so much is known for k=4. The notion k-^∗GDD was first introduced by Chen et al. and used to construct . The necessary condition for the existence of a is v≥14. In this paper, it is proved that there exists a for any prime power and v≥19. By using this result, the known results on the existence of optimal quaternary constant weight codes are then extended.     

关于矩形和斜带模型的反强迫数和反凯库勒数

在苯类化合物的凯库勒结构的研究中引入了反强迫数和反凯库勒数.通过分析矩形和斜带模型苯类化合物的分子图的结构,证明了具有k行l列的矩形R[k,l]和斜带模型Z[k,l]的反凯库勒数是2,R[k,l]的反强迫数是l,Z[k,l]的反强迫数不超过[(l+1)/2],其中[x]表示不超过x的最大整数.     

单模辐射场作用下两二能级原子的Wigner-Yanse偏振信息

研究了与单模辐射场作用过程中两二能级原子的Wigner-Yanse信息.结果表明：两原子总Wigner-Yanse偏振信息依赖于处于基态|gg>, 第一激发态(|ge>+|eg>)/2^(1/2)和第二激发态|ee>的概率. 由于光场的作用, 总Wigner-Yanse偏振信息呈现出周期性的丢失与恢复现象, 但原子间的偶极-偶极相互作用对Wigner-Yanse信息的丢失有阻抗作用.     

Cohomology,extensions and automorphisms of skew braces

The second cohomology group of a left skew brace with coefficients in a trivial left brace with non-trivial actions is defined, its connection with extensions of a left skew brace by a trivial brace is established and a Wells' like exact sequence relating the second cohomology group with inducible automorphisms of an extension of left skew braces is constructed.