共查询到20条相似文献，搜索用时 734 毫秒
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本文主要讨论在三维射影空间里一个二次曲面关于一个非退化二次曲面的配极变换下的配极图形的情况，运用对射变换和对偶原理进行论证，得到文中的定理1至定理4及其有关推论。将它们应用于二维射影空间，便得到相应的定理5至定理8及其推论。从而使得Maclaurin定理[1]作为定理7至定理8在特殊情况下的推论。指出了Maclaurin定理是配极变换下的一对配极图形之间的对应关系。最后应用这些定理证明一些配极图形。 相似文献
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陈友明 《新疆教育学院学报》1996,(4)
本文仅讨论常态二次曲线。其非齐次方程和齐次方程分别为：配极变换：平面内的点与其关于一条常态二次曲线的极线成—一对应，这种—一对应称为配极对应（配极变换）。其表达式为：其中为非零常数，Y（y1，y2，y3）为平面内一点，其极线是U（u1，u2，u3），Aij是系数行列式|aij 相似文献
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本文主要通过初等几何的方法对欧氏平面进行扩充,而后给出扩充后的欧氏平面上所有点与所有直线之间的配极对应,并阐明其本质,最后给出它的一些应用. 相似文献
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对重合区域较少的两组不同角度获取的三维人脸点云数据,直接寻找对应点进行点云拼合的难度很大。为解决这一问题,提出一种基于EGI和标准人脸模板全自动点云数配准拼合算法。针对待配准的三维人脸点云以及标准人脸点云模型,首先通过局部最小二乘曲面拟合,估计每个点的法向和曲率,其次计算点云的扩展高斯图(EGI),然后利用EGI上对应的特征点计算欧拉角,分别使待配准三维人脸点云旋转至与人脸模型大致相同的位置,完成粗配准,并把粗配准结果作为新的初始位置。采用最近点迭代算法(ICP)分别对三维人脸点云与标准人脸模型进行精确配准,从而实现两组三维人脸点云的拼接。 相似文献
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为研究橡胶沥青开级配混合料的马歇尔设计方法以及开级配混合料罩面应用的关键技术,通过析漏试验、飞散试验和不同次数的马歇尔击实试验提出了橡胶沥青开级配混合料油石比预估方法和马歇尔击实标准,表明油石比预估可采用亚利桑那州的预估公式,马歇尔击实标准采用双面50次.通过对开级配混合料级配对性能影响的分析,提出了橡胶沥青开级配混合料的级配范围,发现橡胶沥青开级配混合料应尽量减少4.75 mm以下集料用量.通过总结橡胶沥青开级配罩面的工程经验,提出了老路处治、粘层设计等方面的关键技术,其中,粘层材料宜采用改性乳化沥青. 相似文献
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园锥曲线可以由各种不同的途径得到,利用配极生成是其中的一种。配极又可以有不同的方式。这里介绍的是从一种平面变换——反演来导出配极,进而得到园锥曲线及其一些主要性质.本文主要采用解析法来实现上述目的. 相似文献
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何大林 《重庆第二师范学院学报》1997,(3)
本文结合师范院校高等几何深的教学实际,借助克莱因关于几何学划分的群论观点,利用变换群的知识说明在射影几何中“1—1对应”的必要。通过欧氏空间的拓广、齐次坐标的引入、对偶原理的应用、一维射影变换式的确定、对合分类以及关于二次曲线的配极对应等探讨了“1—1对应”在高等几何研究中的作用和影响。 相似文献
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宋占奎 《温州职业技术学院学报》2011,11(3):49-52
判别二阶曲线射影分类方法有自极三角形法、选点法、主子式法、配方法和初等变换法。五种方法可把任给一条二阶曲线的方程化为标准形式,再判断它的类型。它们各有所长,可根据实际要求选择使用。 相似文献
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利用正则量子化方法以及de Broglie-Bohm解释求解得一个球对称量子黑洞解，该解满足量子力学的对应原理，在普朗克常数趋于零时退化为史瓦西解。 相似文献
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使用G(HL)~SHA膜系。制作0.85μm红外介质薄膜偏振片。经测量,透射光偏振度P_T=99.0％;反射光偏振度P_R=99.3％,工艺简单、镀制方便。文中膜系设计的基本原理和实验方法,不依赖于某个特定的波长,在所使用的介质透明范围内具有普遍意义。 相似文献
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Taking Wittgenstein's love of music as my impetus, I approach aporetic problems of epistemic relativity through a round of three overlapping (canonical) inquiries delivered in contrapuntal (higher and lower) registers. I first take up the question of scepticism surrounding 'groundless knowledge' and contending paradigms in On Certainty (physics versus oracular divination, or realism versus idealism) with attention given to the role of 'bedrock' certainties in providing stability amidst the Heraclitean flux. I then look into the formation of sedimented bedrock knowledge, or practices of knowing, by comparing Wittgenstein's remarks on animal habituation and initiate training into human forms of life. In the latter case, mastery of techniques—our common education—secures agreement in judgment. Finally, I entertain Wittgenstein's obscure references to Einstein's Relativity in Zettel , showing initiate training as a way of 'setting the clocks' with variable degrees of certainty, relative to the language-games played. Together, these three approaches help us to stop the 'endless circling' when philosophers try to address knowledge questions through the logic of object and designation, or verification of correspondence between propositions and things. Instead, attention moves to the way we educate our children and how we employ agreements and bedrock certainties in practices. 相似文献
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In standard canonical correlation analysis （CCA）, the data from definite datasets are used to estimate their canonical correlation. In real applications, for example in bilingual text retrieval, it may have a great portion of data that we do not know which set it belongs to. This part of data is called unlabeled data, while the rest from definite datasets is called labeled data. We propose a novel method called regularized canonical correlation analysis （RCCA）, which makes use of both labeled and unlabeled samples. Specifically, we learn to approximate canonical correlation as if all data were labeled. Then, we describe a generalization of RCCA for the multi-set situation. Experiments on four real world datasets, Yeast, Cloud, Iris, and Haberman, demonstrate that, by incorporating the unlabeled data points, the accuracy of correlation coefficients can be improved by over 30%. 相似文献
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关于提高函授教学质量的几点思考 总被引：2，自引：0，他引：2
函授“自学为主,面授为辅”的特点,决定了只有抓好自学和面授两大教学环节,才能有效地提高函授的教学质量。网络教学对于改革函授传统的教学方式和手段,提高函授的教学质量具有重要的现实意义。 相似文献
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甘乃峰 《鞍山师范学院学报》2015,(6):1-6
研究了套代数框架下具有内部环结构控制器的线性系统鲁棒镇定问题。首先,介绍了一种新型的控制器———具有内部环结构控制器以及它的等价形式———典范或对偶典范控制器;其次,给出了系统具有扰动情况下鲁棒镇定的几个充分条件;最后,得出相应的结论。 相似文献
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弹性学分制具有灵活性、自主性和开放性,更能适舍成人高等函授教育在职学生的特点,它成为成人高等教育实行教学管理改革的一种趋势,同时也应看到成人高等函授教育实行弹性学分制存在的一些问题,并提出解决相应问题的思路。 相似文献
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李大林 《柳州职业技术学院学报》2008,8(3):72-75
研究实数域上亏损矩阵的幂的算法。考虑到不易从它的特征多项式获得构成广义若当标准型的阶数更小的广义若当块的有关信息,针对矩阵乘法不满足交换率,本文从计算广义若当标准型的幂的一般形式出发,获得实数域上亏损矩阵的幂的一个简洁表示。 相似文献
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Guanglun Michael Mu 《Educational Philosophy and Theory》2020,52(12):1266-1276
AbstractBourdieu carved out a distinctive analytical niche for his reflexive sociology. His epistemological tool of field analysis, sometimes coupled with statistical correspondence analysis, is particularly powerful when deciphering the matrix of objective structures and subjective structures within social spaces (field) where agents vie for positions (capital), strategise dispositions (habitus), and negotiate practices. When grappling with the inner workings of the social world and the logic of practice within the social world, Bourdieu favours his field theory over network theory and considers correspondence analysis to be superior to regression analysis. In this paper, I argue that Bourdieu’s canonical theory-laden analytical framework does not exclude other methodological approaches. Indeed, Bourdieu himself argues against ‘methodological monotheism’. I therefore make an attempt to develop a Bourdieusian approach to Social Network Analysis (SNA) and regression analysis, despite Bourdieu’s explicit rebuttal to these methodological schools. To this end, I first review Bourdieu’s rebuttal to network analysis and regression analysis. I then tentatively incorporate SNA and regression into Bourdieu’s analytical framework. This is followed by an example of using SNA and regression in Bourdieusian research conducted in a Chinese educational context. In this vein, I engage with a Bourdieusian rebuttal to Bourdieu’s rebuttal. 相似文献
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《Chinese Education & Society》2013,46(1):122-127
Our health institute is a reference unit for correspondence education in preventive medicine. After correspondence education was started, the leadership decided that Comrade Yeh Chung-sheng, a barefoot doctor of Lang-hu Brigade, and I would assume the responsibilities of dual-service tutors. When we got this assignment, the two of us were very happy, and we looked on this work as a glorious political task delegated to us by the Party. Since the schooling was begun, in addition to strengthening our relationship with the correspondence students during regular hours, we have also had one concentrated session of tutoring each month, following the preventive medicine teaching materials written by the Shanghai No. 1 Medical Institute. Through experience, we have come to understand that it really is not very easy to be a good dual-service tutor. 相似文献