以问题为中心 推动课堂教学

新课标提出:问题是探究的起点,一切数学教学都应该从问题出发,到更高一级问题的产生.问题中心是指课堂教学中教师、学生围绕问题所形成的系统,课堂藉以问题形式展开,学生通过问题学习,教师经由问题组织教学.其核心是教学始终把问题作为学生发展的载体,用基本问题及其解决来建构知识,让学生自觉、主动地发现问题、提出问题、探究问题、形成问题意识.1.问题情境教学的含义以问题为中心组织教学,强调把学习设置到有意义的问题情景中,这就需要教者尽心设计问题情境.所谓问题情境教学,就是教学中将数学课程本身与现实生活中所熟悉的问题或学生个…     

离散设施选址问题研究综述

本文首先回顾了设施选址问题百年发展历史,认为其研究经历了零散研究、系统研究、不确定性研究三个阶段.离散选址问题包括中值问题、覆盖问题、中心问题、多产品问题、动态问题、多目标问题、路径选址问题、网络中心选址问题8个子问题.最后作者讨论了选址问题研究中存在的问题以及今后发展的趋势.     

以问题为中心推动课堂教学

新课标提出:问题是探究的起点,一切数学教学都应该从问题出发,到更高一级问题的产生.问题中心是指课堂教学中教师、学生围绕问题所形成的系统,课堂藉以问题形式展开,学生通过问题学习,教师经由问题组织教学.其核心是教学始终把问题作为学生发展的载体,用基本问题及其解决来建构知识,让学生自觉、主动地发现问题、提出问题、探究问题、形成问题意识.……     

以问题为中心推动课堂教学

新课标提出:问题是探究的起点,一切数学教学都应该从问题出发,到更高一级问题的产生.问题中心是指课堂教学中教师、学生围绕问题所形成的系统,课堂藉以问题形式展开,学生通过问题学习,教师经由问题组织教学.其核心是教学始终把问题作为学生发展的载体,用基本问题及其解决来建构知识,让学生自觉、主动地发现问题、提出问题、探究问题、形成问题意识.……     

一类非单调互补问题的Canonical对偶问题研究

对于一类具有广泛应用背景的非单调互补问题,我们构建了这类问题的Canonical对偶问题。其对偶问题可以写成和原问题类似的互补问题。我们给出了对偶问题和原问题解之间的对偶关系,并且将对偶问题转化成一个一维优化问题,这不但可以方便的求解这类问题,也为研究这类问题性质提供了一个非常直观的研究工具。最后,本文给出了几个算例来演示对偶问题的性质。     

数学转化的思想方法

数学转化思想是“把问题元素从一种形式向另一种形式转化的能力”．就解题的本质而言,解题既意味着转化,既把生疏问题转化为熟习问题,把抽象问题转化为具体问题,把复杂问题转化为简单问题,把一般问题转化为特殊问题,把高次问题转化为底次问题;把未知条件转化为已知条件,把一个综合问题转化为几个基本问题,     

数学家货郎问题的计算复杂性研究

货郎问题(TSP)是研究计算复杂性理论的经典问题.在货郎问题的基础上,提出"数学家货郎问题"(MTSP).经过研究发现,数学家货郎问题是一个典型的NP类问题,但它却不属于P类问题.因此,数学家货郎问题是一个NP类问题与P类问题不相等的例证.     

交叉数学规划问题

本文提出了一个新的数学规划概念──交叉数学规划问题．该问题的提出是以经济问题为其背景的．许多已有的规划问题上。对偶规划问题、双水平规划问题、多目标规划问题、参数规划问题以及对策问题均可作为交叉规划问题的特例．本文除系统地给出交及数学规划问题的基本定义外，还分别对各类交叉规划问题的有关理论及求解方法进行了初步的探讨．     

一种大规模规划的分解——调协解法

将一个大的主问题分解成若干个小的子问题,一方面对子问题寻优,一方面逐步调整主问题与子问题之间、子问题与子问题之间的关系,最后达到主问题最优,这就是解大规模规划问题的主要手段之一——分解-调协法。本文将一个大规模规划问题分解成由若干个子规划组成的多目标规划的序列,并在后一问题的解集合序列上求出前一问题的最     

高考数学应用题十年回顾

自1995年在高考中引入数学应用问题起，为培养中学生数学应用意识的新题型——数学应用题成为每年数学高考的一道“大菜”，从简单的贺卡分配问题到复杂的价格问题、人口耕地粮食问题、全程运输成本问题，污水处理的质量分数问题、带钢冷轧减薄问题、西红柿的种植与成本问题、旅游业的投入产出问题，汽车保有量问题，台风预报问题等，逐步形成贴近课本、贴近生活、贴近学生实际，贴近问题的实际，     

A general type of twisted anomaly cancellation formulas

For even-dimensional manifolds, we prove some twisted anomaly cancellation formulas which generalize some well-known cancellation formulas. For odd dimensional manifolds, we obtain some modularly invariant characteristic forms by the Chern-Simons transgression and we also get some twisted anomaly cancellation formulas.     

Characteristic Formulas of Partial Heyting Algebras

The goal of this paper is to generalize a notion of characteristic (or Jankov) formula by using finite partial Heyting algebras instead of the finite subdirectly irreducible algebras: with every finite partial Heyting algebra we associate a characteristic formula, and we study the properties of these formulas. We prove that any intermediate logic can be axiomatized by such formulas. We further discuss the correlations between characteristic formulas of finite partial algebras and canonical formulas. Then with every well-connected Heyting algebra we associate a set of characteristic formulas that correspond to each finite relative subalgebra of this algebra. Finally, we demonstrate that in many respects these sets enjoy the same properties as regular characteristic formulas. In the last section we outline an approach how to generalize these obtained results to the broad classes of algebras.     

Weighted inner products of derivatives of L2-holomorphic functions on the unit ball

In this paper, we give an algorithmic method of constructing inner product formulas which contain weighted inner products of holomorphic functions on the unit ball. This result covers all inner product formulas which have been proved before. As an application, we prove Zhu’s characterization theorem by an elementary method. Finally, by using one-to-one correspondence between inner product formulas and lattices with circles, we prove all inner product formulas again without any complicated computation.     

基于泰勒级数展开的一点超前差分公式的推导

传统的数值微分公式有前向差分、后向差分和中心差分公式.所谓一点超前差分公式,就是后向差分公式在形式上"前移"一点来计算一阶导数的公式.该公式有效地弥补了传统差分公式的不足之处.不同于以前研究中使用拉格朗日公式来推导一点超前公式的做法,给出了基于泰勒级数展开的对该组公式及其截断误差的推导,从另一个角度验证了一点超前公式,使其更为完善.     

分解与积分有理函数的直接方法

通过多项式分析,构造出用于确定有理函数分解式系数的两种直接公式.为了提高公式的使用效率,引入先期分解的概念,给出了公式的连环应用方法.同时,将公式的使用范围扩展到复数域,建立起适用于共轭复根的积分公式,避免了有理函数积分的递推过程.     

可逆矩阵的高次伴随矩阵

用数学归纳法推出了可逆矩阵的高次伴随矩阵的公式,并结合可逆矩阵的基本公式得出了可逆矩阵的高次伴随矩阵的行列式和逆矩阵,给出了可逆矩阵的高次伴随矩阵的特征值和特征向量的表示公式,最后讨论了若干个可逆矩阵的乘积的高次伴随矩阵.     

Linear CNF formulas and satisfiability

In this paper, we study linear CNF formulas generalizing linear hypergraphs under combinatorial and complexity theoretical aspects w.r.t. SAT. We establish NP-completeness of SAT for the unrestricted linear formula class, and we show the equivalence of NP-completeness of restricted uniform linear formula classes w.r.t. SAT and the existence of unsatisfiable uniform linear witness formulas. On that basis we prove NP-completeness of SAT for uniform linear classes in a resolution-based manner by constructing large-sized formulas. Interested in small witness formulas, we exhibit some combinatorial features of linear hypergraphs closely related to latin squares and finite projective planes helping to construct rather dense, and significantly smaller unsatisfiable k-uniform linear formulas, at least for the cases k=3,4.     

Some formulas related to Hurwitz–Lerch zeta functions

In this paper, we consider multiplication formulas and their inversion formulas for Hurwitz–Lerch zeta functions. Inversion formulas give simple proofs of known results, and also show generalizations of those results. Next, we give a generalization of digamma and gamma functions in terms of Hurwitz–Lerch zeta functions, and consider its properties. In all the sections, various results are always proved by multiplication and inversion formulas.     

Ultraproducts and Higher Order Formulas

Which ultraproducts preserve the validity of formulas of higher order logics? To answer this question, we will introduce natural topologies (which we call ultratopologies) on ultraproducts. We will show, that ultraproducts preserving certain higher order formulas can be characterized in terms of these topologies. As an application of the above results, we provide a constructive, purely model theoretic characterization for classes definable by second order existential formulas.     

Fuzzy Horn logic I

The paper presents generalizations of results on so-called Horn logic, well-known in universal algebra, to the setting of fuzzy logic. The theories we consider consist of formulas which are implications between identities (equations) with premises weighted by truth degrees. We adopt Pavelka style: theories are fuzzy sets of formulas and we consider degrees of provability of formulas from theories. Our basic structure of truth degrees is a complete residuated lattice. We derive a Pavelka-style completeness theorem (degree of provability equals degree of truth) from which we get some particular cases by imposing restrictions on the formulas under consideration. As a particular case, we obtain completeness of fuzzy equational logic.