Rejoinder on “Imprecise probability models for learning multinomial distributions from data. Applications to learning credal networks”

In this paper we answer to the comments provided by Fabio Cozman, Marco Zaffalon, Giorgio Corani, and Didier Dubois on our paper ‘Imprecise Probability Models for Learning Multinomial Distributions from Data. Applications to Learning Credal Networks’. The main topics we have considered are: regularity, the learning principle, the trade-off between prior imprecision and learning, strong symmetry, and the properties of ISSDM for learning graphical conditional independence models.     

Expansive learning: lessons from one teacher’s learning journey

The provision of quality learning experiences for teachers is critical to mathematics reform agendas aimed at equitable and culturally responsive teaching. In this paper we use an activity theory framework to explore one teacher’s learning journey. Drawing on the teacher’s self-report of his journey 1 year after his participation in an intervention designed to support the introduction of mathematical inquiry practices we examine those factors that supported expansive learning. In seeking to understand our pedagogical stance within the intervention we gained new insights into the provision of research based tools to support learning, the provision of space for individual and collective learning, and the provision of a safe learning environment both within the programme, the class, and the wider professional community. These factors are important in understanding transformational changes associated with ambitious pedagogy.     

Why learning doesn’t add up: equilibrium selection with a composition of learning rules

In this paper, we investigate the aggregate behavior of populations of learning agents. We compare the outcomes in homogenous populations learning in accordance with imitate the best dynamics and with replicator dynamics to outcomes in populations that mix these two learning rules. New outcomes can emerge. In certain games, a linear combination of the two rules almost always attains an equilibrium that homogenous learners almost never locate. Moreover, even when almost all weight is placed on one learning rule, the outcome can differ from homogenous use of that rule. Thus, allowing even an arbitrarily small chance of using an alternative learning style can shift a population to select a different equilibrium.     

Puzzle-based learning in engineering mathematics: students’ attitudes

The article reports on the results of two case studies on the impact of the regular use of puzzles as a pedagogical strategy in the teaching and learning of engineering mathematics. The intention of using puzzles is to engage students’ emotions, creativity and curiosity and also to enhance their generic thinking skills and lateral thinking ‘outside the box’. Students’ attitudes towards this pedagogical strategy are evaluated via short questionnaires with two groups of university students taking a second-year engineering mathematics course. Students’ responses to the questionnaire are presented and analyzed in the paper.     

f.f.p.维数

本文对每个环R定义了同调维数l.f.f.p.D(R),并讨论了该维数与环的弱维数及整体维数之间的关系。同时刻画了l.f.f.p.D(R)为有限的环。此外还计算了可换凝聚局部环的维数f.f.p.D(R)。H.Bass的一个早期结果是本文一主要结果之推论。     

M.K.d.V.方程的数值方法

自从Zabusky和Kruskal用数值方法发现Soliton以来,Korteweg-de Vries(K.d.V.)方程的数值解法引起了广泛的兴趣,出现了大量的实际计算和某些理论分析结果。例如[1—8],郭本瑜最近的报告回顾了这方面的工作。比较起来,另一类具有Soliton解的广义K.d.V.方程的数值解法研究得还不多,严格的理论分析结果尚未     

Об одной теореме И. И. П ривалова

Let G be a finite Jordan domain,f(z)=u(z)+iv(z) an analytic function inG. Connections between smoothness of the functionu(z) on dG and smoothness of the functionf(z) on ¯G are obtained. In these results the regionG is assumed to satisfy the condition

关于R.M.Stephenson.Jr.定理的一个注记

在文献[1]中,R.M.Stepheson.Jr.提出问题:是否每一个局部弱紧的,第一可数的正则的空间都存在一个第一可数的正则的一闭扩充?在此文中,我们给出了一个非弱紧而局部弱紧空间 X 具有形状为 X ∪{∞}的,第一可数的正则一闭扩充的充分必要条件,同时得到了两个有趣的推论。     

A.H.柯尔莫戈洛夫

本文简要阐述了当代著名数学家,苏联的柯尔莫戈洛夫的生平及其对数学、科学和教育作出的贡献.     

读者.作者.编者

本刊 2 0 0 0年第 2期“数学问题解答”栏中的第 1 2 32题刊出后 ,一些读者来信指出了该题解答中的一些不妥之处 ,现把几位读者的意见整理如下 ,供大家研究 .原解答中的不妥处 :“由 78.91 1 n 31 1 n - 8,进而可知 P2 0 0 0 >(1 1 ) (1 13) (1 15) .4736.5847.6958…… (1 1× 2 0 0 0 31 1× 2 0 0 0 - 8)= 81 5. 2 2 0…     

Modeling the hiding–learning dynamics in large living systems

This paper deals with the modeling of large systems of interacting entities in the framework of the mathematical kinetic theory for active particles. Various mathematical structures of the hiding–learning dynamics are derived at the mesoscopic scale. Subsequently, these structures are further detailed referring to modeling issues and, in particular, to the learning-hiding competition among tumors and the immune system cells.     

Can peer assisted learning be effective in undergraduate mathematics?

We report the implementation and evaluation of a ‘peer assisted learning’ (PAL) scheme designed to reduce the so-called ‘cooling off’ phenomenon in undergraduate mathematics. ‘Cooling off’ occurs when mathematics undergraduates lose motivation and interest in their studies, despite having previously actively chosen to study it at higher levels. We found that, despite concerns about the novel didactic contract inherent in PAL schemes, a majority of students chose to engage with the scheme, and that the student leaders of the PAL sessions were generally capable of implementing a student-centred pedagogy. Furthermore, we found that students who attended the PAL sessions had higher achievement in their final examinations, even after controlling for their lecture attendance and prior attainment. We conclude by arguing that PAL may provide a useful mechanism for reducing the prevalence of the ‘cooling off’ phenomenon in some – but not all – groups of mathematics students.     

Investigating students’ perceptions of graduate learning outcomes in mathematics

ABSTRACT

The purpose of this study is to explore the perceptions mathematics students have of the knowledge and skills they develop throughout their programme of study. It addresses current concerns about the employability of mathematics graduates by contributing much needed insight into how degree programmes are developing broader learning outcomes for students majoring in mathematics. Specifically, the study asked students who were close to completing a mathematics major (n = 144) to indicate the extent to which opportunities to develop mathematical knowledge along with more transferable skills (communication to experts and non-experts, writing, working in teams and thinking ethically) were included and assessed in their major. Their perceptions were compared to the importance they assign to each of these outcomes, their own assessment of improvement during the programme and their confidence in applying these outcomes. Overall, the findings reveal a pattern of high levels of students’ agreement that these outcomes are important, but evidence a startling gap when compared to students’ perceptions of the extent to which many of these – communication, writing, teamwork and ethical thinking – are actually included and assessed in the curriculum, and their confidence in using such learning.     

p.n.p.矩阵的一些性质

一个n阶实方阵若其各阶主子式皆非正,则称为部分非正阵,简写作p.n.p.矩阵.特别地,各阶主子式皆负的p.n.p.矩阵称为部分负矩阵,简写为p.n.矩阵。文[1]、[5]讨论了p.n.p.矩阵的谱性质。本文在[5]的基础上讨论了p.n.p.矩阵的若干性质,并给出p.n.p.矩阵特征值的某些估计式。 引理1 设A=(A_(ij)_n×n为一p.n.p.矩阵,则A的特征值之实部不全为负(n≥2)。 证 设λ_1,λ_2,…,λ_n为A的全部特征值。假定A的每一特征值之实部皆为负。分两种情