Composite Julia sets generated by infinite polynomial arrays

A definition of a generalized filled-in Julia set generated by an infinite array of proper polynomial mappings in  is introduced. It is shown that such Julia sets depend analytically on the defining polynomial mappings.     

Axiomatic homotopy theory for operads

We give sufficient conditions for the existence of a model structure on operads in an arbitrary symmetric monoidal model category. General invariance properties for homotopy algebras over operads are deduced.     

Morse Theory and Evasiveness

M   is a non-contractible subcomplex of a simplex S then M is evasive. In this paper we make this result quantitative, and show that the more non-contractible M is, the more evasive M is. Recall that M is evasive if for every decision tree algorithm A there is a face of S that requires that one examines all vertices of S (in the order determined by A) before one is able to determine whether or not lies in M. We call such faces evaders of A. M is nonevasive if and only if there is a decision tree algorithm A with no evaders. A main result of this paper is that for any decision tree algorithm A, there is a CW complex M', homotopy equivalent to M, such that the number of cells in M' is precisely

胡适出使英国始末

1937年9月-1942年8月，胡适在美国度过了5年外交生涯。任大使期间，在经费困难和国际环境险恶的情况下，他一方面与美国上层频繁接触，获得了美国的两笔贷款，为抗战筹措资金；另一方面豁出性命讲演，宣传蒋介石和国民政府的对日政策，为抗日作舆论宣传。但由于客观环境的限制和他人的误解，以及与宋子文之间的龃龉，最终被蒋介石免职。     

U型膨胀剂对防水混凝土结构开裂的抑制作用

钢筋砼抗渗结构的开裂是渗漏的主要原因，这个带有普遍性的问题长期困扰着广大施工技术人员。在普通砼中掺入适量的U型膨胀剂，减小了砼结构开裂的可能性，提高了砼的抗渗能力，为防水砼的施工提供一种借鉴的方法。     

Generalized loopy 2U: A new algorithm for approximate inference in credal networks

Credal networks generalize Bayesian networks by relaxing the requirement of precision of probabilities. Credal networks are considerably more expressive than Bayesian networks, but this makes belief updating NP-hard even on polytrees. We develop a new efficient algorithm for approximate belief updating in credal networks. The algorithm is based on an important representation result we prove for general credal networks: that any credal network can be equivalently reformulated as a credal network with binary variables; moreover, the transformation, which is considerably more complex than in the Bayesian case, can be implemented in polynomial time. The equivalent binary credal network is then updated by L2U, a loopy approximate algorithm for binary credal networks. Overall, we generalize L2U to non-binary credal networks, obtaining a scalable algorithm for the general case, which is approximate only because of its loopy nature. The accuracy of the inferences with respect to other state-of-the-art algorithms is evaluated by extensive numerical tests.     

On the subdivision of small categories

We present an intrinsic and concrete development of the subdivision of small categories, give some simple examples and derive its fundamental properties. As an application, we deduce an alternative way to compare the homotopy categories of spaces and small categories, by using partially ordered sets. This yields a new conceptual proof to the well-known fact that these two homotopy categories are equivalent.     

Rigidity in motivic homotopy theory

We show that extensions of algebraically closed fields induce full and faithful functors between the respective motivic stable homotopy categories with finite coefficients.     

智能化数字用户环路倍增系统

利用语音压缩技术和ＩＳＤＮＵ接口实现的数字用户环路倍增设备，可在一对用户线上传输多路高质量的话音或数据。介绍了该系统的技术基础、传输结构和软硬实现及其监控管理功能。     

Tree-level breaking of SU(2)×U(1) in general SUGRA theories

It is shown that SU(2)×U(1) can be broken at the tree level, without the occurrence of global potential minima that break U(1)_e.m., in supergravity models that are more general than those proposed by Nilles, Srednicki and Wyler. The study comprises an analysis of models with a general soft supersymmetry-breaking structure as well as those of the Hall-Lykken-Weinberg type.