共查询到20条相似文献，搜索用时 156 毫秒
1.
《南阳师范学院学报》2015,(9)
利用直接微分方法,结合笛卡尔坐标系下的Navier-Stokes方程的数学形式,通过计算建立了球坐标系下Navier-Stokes方程的完整表示形式.同时,考虑不可压缩Stokes流体流动的特点,略去Navier-Stokes方程中的惯性力项,采用分离变量法得到了Stokes流动问题的古典解. 相似文献
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在股票价格波动服从几何布朗运动规律的条件下,研究了保险公司的一般最优控制问题,得到了一般最优控制问题价值函数的HJB方程,利用鞅方法证明了HJB方程的识别定理,得到了一般最优控制问题中的最优策略。 相似文献
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《南阳师范学院学报》2015,(12):7-11
研究黏性系数μ(ρ)=ρα,α∈(0,1]的一维等熵可压缩Navier-Stokes方程的自由边界问题,通过对一维等熵可压缩Navier-Stokes方程的能量估计、新熵估计、密度上下界等先验估计和对于非真空的正则初始值,可以把一维等熵可压缩Navier-Stokes方程的抛物方程按线性热方程来考虑,则证明该问题存在唯一的整体强解. 相似文献
4.
田卫军 《咸阳师范学院学报》2006,21(6):8-11,30
用非协调有限元方法进行定常Navier-Stokes方程的求解,证明了解的稳定性问题,对揭示逼近解的变化规律有重要意义,为数值求解定常Navier-Stokes方程提供了新的思路。 相似文献
5.
混合插值法求解Navier-Stokes方程 总被引：1，自引：0，他引：1
利用算子分裂法将粘性不可压流体Navier-Stokes方程表述的物理过程分解为扩散和对流2个过程,建立起它们的有限元方程.采用9节点四边形等参元中的形函数描述单元中流体的速度场,而利用这种单元的4个顶点节点构成的插值函数描述单元中流体的压力场,通过有限元生成系统(FEPG)进行Navier-Stokes方程的单元子程序的生成,得到求解不可压粘性流体Navier-Stokes方程的有限元程序,并用它对粘性不可压流体的挠圆柱流动问题进行了数值模拟,分析结果与试验结果吻合. 相似文献
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基于压力投影稳定有限元方法,给出一个求解具有Friction边界条件的Navier-Stokes方程的两重牛顿校正算法.从获得的误差估计可以看出,如果细网格尺度满足h=O(H4),那么该两重牛顿校正算法与一重稳定有限元方法具有相同的收敛阶.与有关文献相比,该算法的计算效率更高. 相似文献
8.
旋转式倒立摆系统控制策略研究 总被引：1，自引：0，他引：1
介绍了一种新型的旋转式倒立摆实验装置,对其系统模型进行动力学分析,建立了一个四阶状态空间方程。分别采用状态反馈和最优控制方法对其进行仿真研究,在此基础上实现倒立摆实时稳定控制。 相似文献
9.
高卓艳 《数学学习与研究(教研版)》2009,(6)
本文采用动态规划方法给出了一种间接求解时间最优控制问题的近似算法.通过引入适当的变换,我们首先将时间最优控制问题转换为一系列终端时间固定的Mayer问题;然后通过引入恰当的粘性因子,将动态规划方法中求解与Mayer问题相应的Hamilton-Bellman-Jacobi方程粘性解的问题转换为对流——扩散方程的求解,进一步采用特征差分法,数值求解此对流——扩散方程,从而得到了一种数值求解时间最优控制问题的近似算法. 相似文献
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吴琍华 《湘潭师范学院学报(社会科学版)》2005,27(1):38-40
高校文化的内部功能有：(1)影响成员意识和规范成员行为，(2)增强学校凝聚力，(3)调节学校内部的社会关系；外部功能有：(1)利用组织意识指导学校与环境互动，(2)利用高校文化特征树立学校形象，(3)利用特定的高校文化适应环境。高校文化的内容包括：意识体系，制度性规范，行为基本模式，象征性符号和模范人物故事和传说等。高校文化的主要特征应与各校特有专业相联系。高校文化内部传播的目的是维持学校内部统一、实现整体协调和整体运作；外部传播的目的是突出本校的文化个性，给公众留下深刻的识别印象，扩大本校对，公众的影响力。 相似文献
12.
试析大清律中例的地位和作用 总被引：1，自引：0，他引：1
赫晓惠 《新乡师范高等专科学校学报》2001,15(2):5-7
清代律例合编的法典编纂形式和“有例不用律”的明确规定，使得清例的法律地位大大提高、律的法律地位大为降低。律例合编一度协调了律例矛盾，例对于律的补充、修改、废止作用也曾适应了统治的需要。但是，由于例多为一人一事而设，为贪官污吏徇私枉法留下了很大的空间，导致吏治腐败，加速了清朝的灭亡。 相似文献
13.
Stephen Petrina 《Interchange》2004,35(1):81-126
What should be learned? How should it be organized for teaching? These seemingly simple questions are deceivingly political. Curriculum theorists are preoccupied with the politics of the first question at the expense of the realpolitik of the second. Instructional designers are preoccupied with the realpolitik of the second question at the expense of the politics of the first. I argue that conceptual distances between curriculum theory and instructional design are based on divisions of labour established during the 1960s. After decades of neglect, curriculum theorists, and specifically critical theorists, appear clueless when it comes to curriculum design and the realpolitik of their causes. When it comes to the realpolitik of practice their political causes are formless. Quite the opposite of critical theorists, instructional theorists nearly mastered the realpolitik of form but have no political causes. I argue that, to contradict the status quo of C&;I, curriculum theorists will have to dirty their hands with the realpolitik of form and instructional designers will have to clutter their heads with theory. 相似文献
14.
邹兴明 《临沂师范学院学报》2008,30(1):87-91
文明是劳动的积累和积累的劳动,是人类智慧和汗水的结晶,是人们开创新的历史的既得力量。人类社会的进步取决于人类文明的历史传承与创造,社会个体的价值寓于个体自身在历史发展过程中对人类文明的传承与创造。历史的实现方式在于人们对人类文明的历史传承与创造。英雄人物在历史中的作用取决于其是否融入创造历史的群众运动中去。人类文明的传承与创造是人类历史走向进步的重要基石,也是人类历史得以延续与发展的社会基因。人类文明的历史传承与创造积淀成历史的现实与现实的历史,人类历史的演进与人类文明的传承与创造齐头并进。 相似文献
15.
It is known by entropy theory that image is a source correlated with a certain characteristic of probability. The entropy rate of the source and ? entropy (rate-distortion function theory) are the information content to identify the characteristics of video images, and hence are essentially related with video image compression. They are fundamental theories of great significance to image compression, though impossible to be directly turned into a compression method. Based on the entropy theory and the image compression theory, by the application of the rate-distortion feature mathematical model and Lagrange multipliers to some theoretical problems in the H.264 standard, this paper presents a new the algorithm model of coding rate-distortion. This model is introduced into complete test on the capability of the test model of JM61e (JUT Test Model). The result shows that the speed of coding increases without significant reduction of the rate-distortion performance of the coder. 相似文献
16.
黄颂 《思茅师范高等专科学校学报》2003,19(1):1-7
全球化是一个以科学技术的进步为基础、以资本的国际流动和世界市场体系的构建为表征的复杂运动。全球化过程客观上蕴涵着一种世界性全方位整合取向。然而，这种一体化运动却遭到了民族国家这种政治结构形式的抵制。因此，全球化过程中的政治文化呈现为明显的民族性碎裂状态。其原因不仅在于政治文化的民族性，同时还在于各种政治体利益的特殊性。全球化进程的不断展开客观上要求把政治文化的民族性置于全球性政治共识的基础上，从而形成一种以全球性共识为基础的多元政治文化格局。 相似文献
17.
孙达 《安阳师范学院学报》2009,(1):87-92
选取“文选学”成立过程当中的关键文学史实作为案例切入,通过系统地分析,如实勾划出六朝隋唐时代文学观念演进的各主要阶段,特别提出中古审美视角转变的三个环节,从而反向论证《文选》和“文选学”正是中古文学观念主要特质的代表。进而将之放在近三百年学术史的坐标上同其它专学的发展作以对比,阐明其美学思想在中国文学史的演进过程中所起的再度深化作用。并在探讨后一子命题的同时,联系传统文献的分类思想,对之进行类型学层面的学术阐释。 相似文献
18.
郑振鹏 《韩山师范学院学报》2006,27(3):30-34
介绍了论文提交系统的开发背景、设计和实现的过程．在系统设计部分主要介绍了论文提交的主要流程、功能结构、各级用户及其角色的定义、系统的功能以及后台数据库的设计．在实现部分,主要说明系统的开发环境和开发工具,并给出主要模块的代码． 相似文献
19.
易匠翘 《湖南大众传媒职业技术学院学报》2003,3(4):97-100
诗歌意象的组合是诗歌话语的组织。从语言学角度对意象跳跃的成因、定义、存在基础及功能进行分析，诗歌意象出现跳跃是由于话语中缺失某些信息因素之间的确定与被确定关系，而使语义间连贯与衔接的正常状态被破坏而造成，它以话语的语用含义作为它在诗歌中存在的基础，能够起到丰富话语意义的作用。 相似文献
20.
《Educational Philosophy and Theory》2009,41(2):155-165
This paper discusses the most persistent controversial issue that occurred in Western educational philosophy ever since Socrates questioned the Sophists: the role of truth in teaching. Ways of teaching these kinds of controversy issues are briefly considered to isolate their epistemic characteristics, which will enable the interpretation of Plato and Dewey as exemplars of rationalism and empiricism regarding the role of knowledge in the curriculum and thus include their partial truths in the epistemic ethos of teaching. The consideration of pedagogy will then include the partial truths of rationalism and empiricism in the epistemic ethos of teaching by following Kant's 'Concepts without percepts are empty; perceptions without conceptions are blind'.
This claim, however, is narrowed down in two ways compatible with postmodernism and the heavy emphasis on constructionism in faculties of education. After quoting Harry Broudy's statement that the educational epistemic ethos should be domain-specific, guided by the experts' inquiry protocols in each curricular area, it is narrowed down further with Maxine Greene's explication that it should be pluralistic and lesson-specific. This epistemic ethos is not argued as a synthesis but as an aggregate of the partial truths of various epistemologies in the spirit of the postmodern doubt in any one theory of knowledge without throwing out the baby with the dirty bath water.
Finally, the streams of consciousness involved in teaching and learning good knowledge are described phenomenologically to disclose how truth can be disclosed in teaching, thereby grounding propositional knowledge, for example, ontologically in the being of the student and in the being of the world. 相似文献
This claim, however, is narrowed down in two ways compatible with postmodernism and the heavy emphasis on constructionism in faculties of education. After quoting Harry Broudy's statement that the educational epistemic ethos should be domain-specific, guided by the experts' inquiry protocols in each curricular area, it is narrowed down further with Maxine Greene's explication that it should be pluralistic and lesson-specific. This epistemic ethos is not argued as a synthesis but as an aggregate of the partial truths of various epistemologies in the spirit of the postmodern doubt in any one theory of knowledge without throwing out the baby with the dirty bath water.
Finally, the streams of consciousness involved in teaching and learning good knowledge are described phenomenologically to disclose how truth can be disclosed in teaching, thereby grounding propositional knowledge, for example, ontologically in the being of the student and in the being of the world. 相似文献