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Ｍａｇｎｕｓ和Ｎｅｕｄｅｃｋｅｒ的《交换矩阵一些结果》一文中增得到当Ｘ’为一个Ｐｎ阶随机矩阵和ｎ〉Ｐ且ＶｅｃＸ’具有分布 相似文献
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张淑玲 《唐山师范学院学报》1999,(5)
Magnus和Neudecker的《交换矩阵一些结果》一文中曾得到当X′为一个P×n阶随机矩阵和n>P且VecX′具有分布为:Nnp(VecM′,IV)时,VecX′的弥散阵的结果。本文进一步讨论当X′为P×n阶随机矩阵和n>P且VecX′具有分布为N_(np)(VecM′,IV)及A为一个非随机矩阵时二次型X′AX的拉直为VecX′AX的弥散阵的通式及推论,从而揭示二次型与多元分析中的一个重要分布——威沙特分布的关系。 相似文献
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推广了卡方分布到拟卡方分布，证明了它的若干性质，并利用这些性质找到了Wishart分布内部及2个多元正态分布或矩阵正态分布之间独立的充要条件。 相似文献
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戴敦敬 《中国科教创新导刊》2012,(11):98-98
本文借助线性代数中矩阵分解和秩,给出了二维离散型随机变量相互独立的一个必要条件和一个充分必要条件,无论在应用上,还是在理论上都是很有价值的。 相似文献
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泵输出的周期性脉动流体的压力脉动，是引起流体谐振、激励管路振动和噪声的主要原因．为了减少振动造成的故障，人们从两方面进行研究：一是研究开发高性能滤波器，消除和抑制脉动压力幅值；二是合理设计管路结构参数，避免流体谐振．两者均需计算不同结构参数和频率下的脉动压力，了解其幅频特性。本文采用刚度矩阵法，对管路各子系统耦合，求解管路系统压力分布，并进行了仿真与实验验证 相似文献
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目的：为了简化二维离散型随机变量的独立性证明过程.方法：引进二维离散型随机变量概率分布的矩阵形式A,用矩阵形式来判断独立性,再利用Matlab软件求解.结果：独立性判定的条件pij=pi.p.j转化为A=AIX.IYA.结论：二维离散型随机变量的独立性判断过程大大简化了. 相似文献
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帽子矩阵在回归诊断，残差分析中有着特殊的作用，讨论帽子矩阵H＝(hij)元素的性质非常重要。给出帽子矩阵对角线元素的一条新的性质。 相似文献
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The purpose of this study was to investigate Turkish early childhood education teachers’ perception of inclusion before they started their teaching profession and to explore their experiences with the children with disabilities in their first year of teaching. Sixteen Turkish pre-service teachers were first interviewed when they completed the teacher education programme about their expectations of inclusion practices in their future career. Four participants among the 16 teachers started to teach children with disabilities in their first year of teaching. Then, they were interviewed about their experiences at the end of the first and second semesters of teaching. Findings revealed that Turkish pre-service teachers displayed positive attitudes towards inclusion before they started teaching. However, they had negative experiences with children with disabilities in their first year due to the misimplementation of the inclusion policy and being inexperienced about the inclusion process, and began to question the effectiveness of inclusion. Implications for the inclusion policy and teacher education programmes are discussed. 相似文献
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This paper reports on an Irish study examining first year students’ recollections of their concerns, motivations, level of
preparedness and perceived skills on entry to university. The study aims to investigate and understand the implications of
the attitudes of first year students as they make the transition to university. It also explores students’ behaviour during
their initial weeks at university. It is important to understand the anxieties of new students, their views on their abilities
and their confidence in managing their new role as these factors will have consequences for their experience as first year
university students. These findings are explored with a view to enhancing the quality of support for students during this
key transition. 相似文献
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This article examines the academic adjustment and learning processes of international and local first‐year students. Twenty first‐year local and international students participated in a semi‐structured interview study upon the completion of their first year in a Faculty of Commerce and Management. Students reported positive and negative critical incidents which helped or hindered their learning during the first year. In addition, students described their feelings, thoughts and behaviours in relation to these incidents. Critical incidents were coded, themes identified, and comparisons made across local and international student groups. The impact of particular teaching processes are considered, and implications for teaching and learning in the first year are discussed. 相似文献
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Academic achievement and cognitive ability have been shown to predict later age at first sexual intercourse. Using a sample of 536 same-sex twin pairs who were followed longitudinally from adolescence to early adulthood, this study tested whether relations between intelligence, academic achievement, and age at first sex were due to unmeasured genetic and environmental differences between families. Twins who differed in their intelligence or their academic achievement did not differ in their age at first sex. Rather, the association between intelligence and age at first sex could be attributed entirely to unmeasured environmental differences between families, whereas the association between academic achievement and age at first sex could be attributed entirely to genetic factors. 相似文献
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本文利用一个全国范围的对不同学历层次、不同年级的在校大学生的问卷调查数据,实证分析了在读大学生的工作期望、预期起薪以及自主创业的意向.基于实证结果可以发现,就业准备会影响到大学生的预期起薪以及自主创业的意愿,因此建议高校的就业指导应该扩大工作范围,将不同年级的学生纳入进来,注重减小各年级在校学生的就业压力、提升他们的就业信心. 相似文献
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As part of a two-year, mixed methods study, the focus of this paper reports the qualitative findings that are related to nine beginning teachers' learning to teach with Information and Communication Technology (ICT) during their first year of teaching. It aims to explore how these teachers deepen their understanding performances of technology integration in their first year. They demonstrated consistent, varied perceptions, frequency and ways of using ICT for classroom teaching and learning from their initial teacher education to their first year teaching. They developed diverse understandings of technology integration from their own practice, and chose to play different roles, such as, follower, doer and emerging teacher leader for technology integration. Suggestions to schools on providing beginning teachers with ongoing technical and pedagogical support and capitalizing on their tech-savvy strengths are discussed. 相似文献
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E.S. Mitrofanova 《Russian Education & Society》2016,58(9-10):601-622
This article presents comparisons of the ages and facts of starting demographic events in Russia based on the findings of three large-scale surveys: the European Social Survey, 2006; the Generations and Gender Survey, 2004, 2007, and 2011; and Person, Family, Society, 2013. This study focuses on the intergenerational and gender differences in the age of sexual debut, first partnership, first marriage, and birth of the first child. Analysis of the data shows that the maximum number of starting demographic events takes place before age 35. In the average biography, the first event is sexual debut, the following events are matrimonial (marriage and partnership/cohabitation), and the last event is the birth of the first child. The greatest gender and generational differences are observed in matrimonial behavior: the popularity of unregistered unions is much greater among younger generations than among their predecessors, and young people’s interest in marriage is much lower. Men begin partnership and marriage about a year or two later than women. In reproductive behavior, there are greater gender differences than generational: men are more inclined to postpone the birth of the first child. This is because women wish to give birth to their first child at a reproductively healthy age, and men prefer to postpone both having their first child and entering their first marriage. 相似文献
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The goal of this study was to illustrate survival analysis with higher education data and gain insight into a limited set of factors that predict when students passed their first‐year examination at a Dutch university. Study participants consisted of 565 first‐year students in four departments. Data were collected on when students pass their first‐year examination, prior achievement and procrastination. The analysis showed that 69% of the students had not passed their examination within the nominal study length of 12 months. The estimated median lifetime, the time when 50% of the students had passed their examination, was after 23 months. Students from the 2nd department passed their examination fastest. Female students reached the estimated median lifetime at 20 months, younger students at 16 months, older students at 24+ months and students with high prior achievement scores at 12 months. The analysis finally indicated that age, prior achievement and procrastination predicted passing first‐year examinations. 相似文献
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Jerrid W. Kruse Jaclyn M. Easter Hallie S. Edgerly Colin Seebach Neal Patel 《Science & Education》2017,26(6):613-636
This study explored changes in preservice teachers’ (PSTs) nature of science pedagogical (NOSP) views and nature of science (NOS) rationales using pre- and post-course written responses as well as interview data. Through systematic analysis, themes were generated and compared to the NOS literature. Comparisons between pre- and post-course data demonstrate improved and deepened NOS views, NOSP views that are more aligned with NOS literature, and a greater number of rationales for including NOS. All participants were enrolled in the “Inquiry and Natures of Science, Technology, and Engineering” (INSTE) course. However, six participants were enrolled in INSTE as their first course in which NOS and NOSP were addressed. The other six participants were enrolled in INSTE as their second course in which NOS and NOSP were addressed, with science methods as their first course in which NOS and NOSP were addressed. By comparing participants enrolled in INSTE as their first course to those enrolled in INSTE as their second course, we observed that NOS understanding seemed to develop in a first experience alongside some NOS rationales, but NOSP views lagged for participants in INSTE as their first course. Participants enrolled in INSTE as their second course developed more robust and literature-aligned NOSP views and more multifaceted NOS rationales. Therefore, this study bolsters arguments that teachers need to receive extended NOS and NOSP instruction. 相似文献
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周腊生 《孝感职业技术学院学报》2005,8(1):26-30
文章在提供全部状元夺魁年份及其中绝大部分人生卒年资料的基础上，分析了他们的年龄、魁龄、魁后生存时间的分布情况，得出其平均年龄、魁龄、魁后生存时间分别为59．53岁、34．58岁和24．45年。 相似文献