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1.
在新课程实施中,一切都在发生着显著的变化;培养目标发生了变化,课程理念发生了变化,教学内容发生了变化,教学形式发生了变化,评价导向发生了变化,学生生活发生了变化,…….但是,所有这些变革与发展都需要一线教师以及相关人员的积极参与,教师自身的理论素养和实践  相似文献   

2.
危机应对术     
陈缨 《珠算》2009,(4):45-45
回忆去年的情况,用一段比较流行的话来说,基本上眼睛一闭一睁,发现世界变了,箭头的方向变了,指标的颜色变了,公司的形势变了,经营业绩变了。  相似文献   

3.
张明 《天府数学》2004,(12):75-76
同学们,朋友们,通过本期的学习,我们认识了数的又一次扩展,理解了坐标的意义及函数关系,会进一步整理数据,知道了相似三角形的特征与识别方法,明确了直角三角形的边角关系,掌握了解决一些简单实际问题的方法,收获可真不小。  相似文献   

4.
以前,一个水果摊的老板因为年岁大了,无法久站招呼客人,于是就发启事招聘一名店员。
  来了一个30多岁的男子,问老板一个月用多少钱请他来帮忙,老板笑着说:“我这小摊生意,哪里付得出月薪,当然是看你的努力了,一天能卖多少水果,收到的钱就给你十分之一,每天领现。”这个男子听了,上下打量打量小水果摊,说太没保障了,掉头走了。  相似文献   

5.
营造文化数学氛围建构数学教育新观念   总被引:1,自引:0,他引:1  
陈明 《数学通报》2004,(10):9-11
在日常数学教学活动中,愈来愈多的学生对数学学习的动力不是来自数学本身,而主要来自于考试的压力,学生被动的数学学习观念,不仅阻止了他们的主动性与探索性,扼杀了数学的魅力,而且不利于数学学科的发展,不利于学生创新思维能力及个人综合能力的形成.也就是说,学生学到了数学的壳,却丢掉了数学的核;学到了数学的形式,却扔掉了数学的美;学到了数学的方法,却抛弃了数学的灵魂.新一轮的数学课程改革提出了数学的应用性、文化性两个新观念,以通过课程、课堂及课外的途径,改变过去重结论轻过程、重理论轻应用、重知识轻能力的局面,给课堂以生机与活力.  相似文献   

6.
快速遴选优胜者   总被引:1,自引:1,他引:0  
本文给出了一个行之有效的方案来确定某次竞赛的优胜者.首先,假定裁判是理想的(无误差的),我们提出了一个基本模型在几乎最短的时间内确定出前W名.在我们的方案中,用一个矩阵来记录从当前已知的裁判评分中所得到的“当前名次”,并且在一轮之后尽可能多地淘汰试卷.然后,我们考虑现实中的裁判(有误差的),估计了最后选出的W名中包含有非前2W名试卷的概率.进一步,考虑到打分方案中的系统偏差,我们用贝叶斯估计对模型做了改进,使不同裁判的评分有了一定的可比性.为检验模型的可行性,我们做了大量的计算机模拟,模型检验中我们发现,如果适当增加从第一轮中选拔出来的试卷数,将使我们的模型结果更好.我们还通过改变参数P,J,W对模型作了稳定性分析,并且得到了一个经验公式,可以用来预测在一定P,J,W值下评卷的总时间.接下来,我们采用了现实生活中的数据来检验模型,结果相当好当P=50,J=3时,若取W=2,用我们的方案得到了第一名和第三名若取W=3,得出的正是前三名.最后,我们总结出了一个灵活实用的方案,并提出了一些建议在模型推广中,我们还利用经验公式对开支做了预算.  相似文献   

7.
货运量预测方法的比较   总被引:15,自引:0,他引:15  
本在对货运量预测理论和程序描述的基础上,介绍并比较了常用预测方法的优缺点,重点研究了三层BP神经网络的基本原理,构思了BP神经网络中长期货运量预测模型,并进行了预测,最后根据预测结果,分析了其用于预测的优缺点。  相似文献   

8.
亲爱的同学们,新课程与你为伴已经有一年的时间.在其中,你了解了很多的数学知识,学会了一些数学技能,体味了数学学习的过程,掌握了一定的学习方法,在学习数学的各方面都有了长足的进步.  相似文献   

9.
例题已知m, 矛一1,矿 夕一2,求“m十bn的最大值.解设了;一(m,n),百2=(a泊)则了,·了:一am十bn =}了,}·}了2 ICos< e:> =夜七。s(了,,了2>. cos(百,,百:>任[o,二],。m bn的最大值为招.本题的传统解法是采用三角代换法,在代换过程中牵扯到的变量较多.此种解法的巧妙在于由本题的已知条件和结论的形式联想到向量数量积的坐标运算,一步到位,简单至极.巧用数量积解题@崔平社$陕西省西安市户县实验中学!(710300)~~  相似文献   

10.
线性约束规划内点法及其修正算法   总被引:1,自引:0,他引:1  
凸规划的内点算法是目前较热门的课题之一,参考资料「2」,「3」等均给出了较深入的研究,本文在参考前人的工作前提下,提出了带线性约束凸规划的内点算法结论及相应算法,另外,本文定义了偏移因子,偏移因子对的概念,对下降方向作出了修正,并给出了相关算法。  相似文献   

11.
In this article, we consider a newly modified two-component Camassa–Holm equation. First, we establish the local well-posedness result, then we present a precise blow-up scenario. Afterwards, we derive a new conservation law, by which and the precise blow-up scenario we prove three blow-up results and a blow-up rate estimate result.  相似文献   

12.
《Discrete Mathematics》2020,343(8):111913
In this paper we are concerned with the classification of the finite groups admitting a bipartite DRR and a bipartite GRR.First, we find a natural obstruction that prevents a finite group from admitting a bipartite GRR. Then we give a complete classification of the finite groups satisfying this natural obstruction and hence not admitting a bipartite GRR. Based on these results and on some extensive computer computations, we state a conjecture aiming to give a complete classification of the finite groups admitting a bipartite GRR.Next, we prove the existence of bipartite DRRs for most of the finite groups not admitting a bipartite GRR found in this paper. Actually, we prove a much stronger result: we give an asymptotic enumeration of the bipartite DRRs over these groups. Again, based on these results and on some extensive computer computations, we state a conjecture aiming to give a complete classification of the finite groups admitting a bipartite DRR.  相似文献   

13.
In this research, we develop and introduce a theoretical and mathematical forecasting framework of immigrant integration using immigrant density as a single driver. First, we introduce the integration concepts we aim at forecasting. Thereafter, we introduce a theoretical and mathematical model of the relationship between integration and immigrant density. Based on this model, we develop a methodological forecasting framework. We test the framework using immigrant integration data from Spain. We produce the forecasts, and conduct the proper evaluation of them. Finally, we conclude with a brief discussion of the wider implications of our results.  相似文献   

14.
Viscoelastic fluids represent a major challenge both from an engineering and from a mathematical point of view. Recently, we have shown that viscoelasticity induces chaos in closed‐loop thermosyphons even when we consider binary fluids, this is, when we consider a solute in the fluid, as water and antifreezes, for example. In this work, we consider a linear friction law, and we show that in this case with the addition of a solute to the fluid we can prove, under some conditions, chaotic asymptotic behavior for suitable geometry of the circuit and heat flux or ambient temperature functions.  相似文献   

15.
In this paper we study nonlinear elliptic boundary value problems with monotone and nonmonotone multivalued nonlinearities. First we consider the case of monotone nonlinearities. In the first result we assume that the multivalued nonlinearity is defined on all ℝ. Assuming the existence of an upper and of a lower solution, we prove the existence of a solution between them. Also for a special version of the problem, we prove the existence of extremal solutions in the order interval formed by the upper and lower solutions. Then we drop the requirement that the monotone nonlinearity is defined on all of ℝ. This case is important because it covers variational inequalities. Using the theory of operators of monotone type we show that the problem has a solution. Finally in the last part we consider an eigenvalue problem with a nonmonotone multivalued nonlinearity. Using the critical point theory for nonsmooth locally Lipschitz functionals we prove the existence of at least two nontrivial solutions (multiplicity theorem).  相似文献   

16.
The aim of this paper is to present a kinetic formulation of a model for the coupling of transient free surface and pressurised flows. Firstly, we revisit the system of Saint-Venant equations for free surface flow: we state some properties of Saint-Venant equations, we propose a kinetic formulation and we verify that this kinetic formulation leads to a Gibbs equilibrium that minimises (in some general case) an energy and preserves the still water steady state. Secondly, we propose a model for pressurised flows in a Saint-Venant-like conservative formulation. We then propose a kinetic formulation and we verify that this kinetic formulation leads to a Gibbs equilibrium that minimises in any case an energy and preserves the still water steady state. Finally, we propose a dual model that couples these two types of flow.  相似文献   

17.
基于跳扩散过程的可转换债券的定价   总被引:2,自引:0,他引:2  
本文标的股票的方程采用跳扩散方程,首先规定一个跳跃的涨跌区间,这样就可以很快的找出跳跃点,我们根据跳跃点将股价聚类,然后把各个类看成是总体中抽取出来的一个样本,我们就可以估计出跳扩散方程中的所有参数.由于我们的标的股票的方程是含跳过程,因此无法找出完全保值的自融资策略,但我们可以根据风险最小化的原理给出可转换债券的价格,最后运用Monte Carlo模拟计算出了南京水运转债在0时刻的价格。  相似文献   

18.
In the present work, that regards the Thurston's theory, we prove that, if we choose a closed curve, how we wish, on a noncompact surface, it is always possible to construct a particular masured foliation that has the choosed curve like a leaf; we also prove this foliation has a remarkable property that makes very easy to mesure all homotopy classes of closed curves of our surface. To prove this statement we need some Propositions and some Lemma that we also demonstre.  相似文献   

19.
Optimal control of nonlinear evolution inclusions   总被引:1,自引:0,他引:1  
In this paper, we study the optimal control of nonlinear evolution inclusions. First, we prove the existence of admissible trajectories and then we show that the set that they form is relatively sequentially compact and in certain cases sequentially compact in an appropriate function space. Then, with the help of a convexity hypothesis and using Cesari's approach, we solve a general Lagrange optimal control problem. After that, we drop the convexity hypothesis and pass to the relaxed system, for which we prove the existence of optimal controls, we show that it has a value equal to that of the original one, and also we prove that the original trajectories are dense in an appropriate topology to the relaxed ones. Finally, we present an example of a nonlinear parabolic optimal control that illustrates the applicability of our results.This research was supported by NSF Grant No. DMS-88-02688.  相似文献   

20.
In this paper, we introduce the notion of expanding topological space. We define the topological expansion of a topological space via local multi-homeomorphism over coproduct topology, and we prove that the coproduct family associated to any fractal family of topological spaces is expanding. In particular, we prove that the more a topological space expands, the finer the topology of its indexed states is. Using multi-homeomorphisms over associated coproduct topological spaces, we define a locally expandable topological space and we prove that a locally expandable topological space has a topological expansion. Specifically, we prove that the fractal manifold is locally expandable and has a topological expansion.  相似文献   

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