Hochschild cohomology of truncated quiver algebras

For a truncated quiver algebra over a field of an arbitrary characteristic, its Hochschild cohomology is calculated. Moreover, it is shown that its Hochschild cohomology algebra is finitedimensional if and only if its global dimension is finite if and only if its quiver has no oriented cycles.     

陀螺仪运动的混沌与KAM理论

本文建立了外环轴水平放置的重力对称陀螺仪的运动方程．将非自由陀螺仪转子的质心位置作为扰动，利用Ｍｅｌｎｉｋｏｖ方法和ＫＡＭ理论研究了陀螺仪的运动，研究结果表明：在 螺仪转子的质心与支架中心不重合且充分接近时，或 螺仪能量充分大时，陀螺仪运动的Ｐｏｉｎｃａｒｅ映射既出现Ｓｍａｌｅ马蹄意义下的混沌，又存在ＫＡＭ不变环面和不变闭曲线。     

DIMENSION AND DIFFERENTIABILIIY OF A CLASS OF FRACTAL INTERPOLATION FUNCTIONS

In this paper, a new iterated function system consisting of non-linear affinemaps is constructed. We investigate the fractal interpolation functions generated bysuch a system and get its differentiability, its box dimension, its packing dimension,and a lower bound of its Hansdorff dimension.     

Retail competition and cooperative advertising

We consider a cooperative advertising channel consisting of a manufacturer selling its product through a retailer in competition with another independent retailer. The manufacturer subsidizes its retailer’s advertising only when a certain threshold is positive. Moreover, the manufacturer’s support for its retailer is higher under competition than in its absence.     

关于李群胚的几点讨论

文章讨论了李群胚作为丛的一些性质,得出李群胚的内子群胚是主丛的结论;研究了李群胚在其内子群胚上的作用,并证明了李群胚上的Maurer-cartan形式在其任意左不变向量场上作用的结果为常数.文末推广了关于李代数胚态射的一个结论.     

A censored copula model for micro-level claim reserving

In this paper, we consider the question of predicting the final amount of a claim and its distribution from micro-level data. A copula model is used to describe the dependence between the amount of a claim and its duration (that is the time between its occurrence and its closure). Due to the presence of censoring, we adapt classical methodologies using a weighting scheme that corrects the bias caused by this incompleteness in the data. Theoretical results and simulation support the validity of the procedure. A real case coming from medical malpractice claims is presented.     

完备强对偶原子分配格上的不可约极小并分解及其应用

在完备强对偶原子分配格上引入了不可约极小并分解的概念,给出了元素存在不可约极小并分解的一些充要条件.证明了当元素恰有一个下邻时,该元索就足完全并既约元;有两个下邻时,元素的不可约极小并分解与不可约完全并既分解是等价的;下邻多于两个时,元素的不可约极小并分解不一定足不可约完全并既分解.最后证明了模糊关系方程有极小解的充要条件是方程左边有大于等于右手项的系数或右手项系数有不可约极小并分解.     

Related structures with involution

We give a necessary and sufficient condition for an involution lattice to be isomorphic to the direct square of its invariant part. This result is applied to show relations between related lattices of an algebra. For instance, generalizing some earlier results of G. Czédli and L. Szabó it is proved that any algebra admits a connected compatible partial order whenever its quasiorder lattice is isomorphic to the direct square of its congruence lattice. Further, a majority algebra is lattice ordered if and only if the lattice of its compatible reflexive relations is isomorphic to the direct square of its tolerance lattice. In the latter case, one can establish a bijective correspondence between factor congruence pairs of the algebra and its pairs of compatible lattice orders; several consequences of this result are given.     

工件存在不同交货宽容期的最大加权超前延误问题

本文考虑下述排序问题：有n个工件需在同一台机器上加工,对各工件有一宽容交货期,若一工件在其宽容期前完工则受加权超前惩罚,若在其宽容期后完工则受加权延误惩罚,要求适当安排一加工方式使最大惩罚最小,文中相应某指定工件需准时完工的上述问题证得了Np-hard性,给出了最优算法,并作了一些讨论。     

Central limit theorem and chaoticity

This paper studies the relations between stochastic properties and chaotic properties of a dynamical system satisfying the central limit theorem. For such a system, it is proved that every nonempty open set in its defining space contains a point with positive lower density of its return time set and that the system is syndetically sensitive, provided that it is strongly topologically ergodic. Moreover, it is shown that the system admits many chaotic properties if its domain is restricted to a tree.