Center and Distinguisher for Strings with Unbounded Alphabet

Consider two sets and of strings of length L with characters from an unbounded alphabet , i.e., the size of is not bounded by a constant and has to be taken into consideration as a parameter for input size. A closest string s* of is a string that minimizes the maximum of Hamming¹ distance(s, s*) over all string s : s . In contrast, a farthest string t* from maximizes the minimum of Hamming distance(t*,t) over all elements t: t . A distinguisher of from is a string that is close to every string in and far away from any string in . We obtain polynomial time approximation schemes to settle the above problems.     

Landau多项式算子与无界函数逼近

利用扩展乘数法构造了 Landau型多项式算子逼近全空间或有界集上无界函数的若干收敛定理 ,给出了具有一般性的结论 ,从而推广了已有文献的若干结果 .     

“有界”与“无界”：二律背反命题界限域的认知语言诠释

“有界”与“无界”是语言学概念中的哲学意义上的二律背反，是认知主体对其在时间、空间、性状和心理上的投射。通过分析梳理可以解释语言符号形式或多或少地映射事物本身的特点，在不同程度上反映主体的认知方式，并且与数量词起制约作用有关的一系列句法现象。但对于两者概念的确立与区分，必须适应一定的“认知域”和对其作主观上的“识解”。在“有界”和“无界”范围之间存在着无限的“准有界，，的认知体，一有界”认知体是认知原型，具有容易学习、记忆、使用等完形特征。“无界”的认知体因为可以被看作为属于另一认知结构，因此可成为新的认知原型。     

Asymptotic properties of a rank estimate in linear regression with symmetric non-identically distributed errors

In this article, a simple linear regression model with independent and symmetric but non-identically distributed errors is considered. Asymptotic properties of the rank regression estimate defined in Jaeckel [Estimating regression coefficients by minimizing the dispersion of the residuals, Ann. Math. Statist. 43 (1972), pp. 1449–1458] are studied. We show that the studied estimator is consistent and asymptotically normally distributed. The cases of bounded and unbounded score functions are examined separately. The regularity conditions of the article are exemplified for finite mixture distributions.     

Estimating Mean Survival Time: When is it Possible?

For right‐censored survival data, it is well‐known that the mean survival time can be consistently estimated when the support of the censoring time contains the support of the survival time. In practice, however, this condition can be easily violated because the follow‐up of a study is usually within a finite window. In this article, we show that the mean survival time is still estimable from a linear model when the support of some covariate(s) with non‐zero coefficient(s) is unbounded regardless of the length of follow‐up. This implies that the mean survival time can be well estimated when the support of linear predictor is wide in practice. The theoretical finding is further verified for finite samples by simulation studies. Simulations also show that, when both models are correctly specified, the linear model yields reasonable mean square prediction errors and outperforms the Cox model, particularly with heavy censoring and short follow‐up time.     

Clifford分析中无界域上正则函数带共轭值带位移的非线性边值问题

讨论了Clifford分析中无界域上正则函数带共轭值带位移的非线性边值问题．首先引入了无界域上正则函数的Plemelj公式，然后利用积分方程的方法和Schauder不动点理论证明了该非线性边值问题解的存在性，并给出了其积分表达式．     

无粘结预应力混凝土施工质量控制

无粘结预应力混凝土是建设部“九五”期间推广应用的十大新技术之一 ,其技术含量高、专业性强 ,施工中应严格控制质量     

基于语料库汉语动结构式有界／无界动词与结果补语无间隔体限制研究

根据Goldberg英语动结构式体限制理论及句子有界化原理建立封闭语料库分析发现，汉语动结构式事件句有界与无界动词与结果补语之间无间隔；建议将Goldberg表时间间隔示意图细化为两个分示意图。     

体外预应力钢筋混凝土梁桥极限承载能力分析

在体外预应力加固钢筋混凝土筒支梁桥的结构分析中，存在正常使用极限状态和承载能力极限状态两阶段，本文通过对体外预应力筋加固构件中的水平筋和斜筋进行在极限承载能力下的极限应力分析，从而得出当两者面积相同时，体外预应力加固钢筋混凝土筒支梁桥的受力特性与无粘结部分预应力混凝土相似，可直接采用无粘结部分预应力混凝土的极限应力作为内水平加固钢筋的极限应力；当两者面积不同时，斜筋对水平筋极限应力的影响较大，且斜筋自身的极限应力也会变化。     

经营决策系统的模型构建及实证研究

随着经济全球化进程的加快,我国企业面临竞争日益激烈的挑战.如何在全球视野下进行有效的决策是管理实践者与理论界迫切需要解决的问题之一.文章解析了在不确定环境下经营决策对于提高企业管理效率的重要意义,深入分析了管理效率在组织的运动机理与特征,以及经营决策质量与管理效率提高之间的关系;在理论研究的基础上,笔者构建了增加决策系统维度的模型,提出了新的决策方法--增加思考维度,最后给出了案例分析与实证研究.