Modal Meinongianism for Fictional Objects

Drawing on different suggestions from the literature, we outline a unified metaphysical framework, labeled as Modal Meinongian Metaphysics (MMM), combining Meinongian themes with a non-standard modal ontology. The MMM approach is based on (1) a comprehension principle (CP) for objects in unrestricted, but qualified form, and (2) the employment of an ontology of impossible worlds, besides possible ones. In §§1–2, we introduce the classical Meinongian metaphysics and consider two famous Russellian criticisms, namely (a) the charge of inconsistency and (b) the claim that naïve Meinongianism allows one to prove that anything exists. In §3, we have impossible worlds enter the stage and provide independent justification for their use. In §4, we introduce our revised comprehension principle: our CP has no restriction on the (sets of) properties that can characterize objects, but parameterizes them to worlds, therefore having modality explicitly built into it. In §5, we propose an application of the MMM apparatus to fictional objects and defend the naturalness of our treatment against alternative approaches. Finally, in §6, we consider David Lewis’ notorious objection to impossibilia, and provide a reply to it by resorting to an ersatz account of worlds.     

Covering Things with Things

An abstract NP-hard covering problem is presented and fixed-parameter tractable algorithms for this problem are described. The running times of the algorithms are expressed in terms of three parameters: $n$, the number of elements to be covered, $k$, the number of sets allowed in the covering, and $d$, the combinatorial dimension of the problem. The first algorithm is deterministic and has a running time of $O(k^{dk}n)$. The second algorithm is also deterministic and has a running time of $O(k^{d(k+1)}+n^{d+1})$. The third is a Monte-Carlo algorithm that runs in time $O(\runtime)$ and is correct with probability $1-n^{-c}$. Here, the $O$ notation hides factors that are polynomial in $d$. These algorithms lead to fixed-parameter tractable algorithms for many geometric and non-geometric covering problems.     

对数学创新能力的认识与思考

培养学生数学创新能力是当前数学教育的一个重要目标.数学创新能力的内涵可以从潜在的认知过程和显现的认知结果两个方面去认识.因此,对学生数学创新能力的培养可从以下三个方面去展开:一是培养学生有条件的质疑精神;二是教师具有良好创新素质;三是革新教学方法,实施情境—问题教学模式.     

常微分方程课程中案例教学的探索、实践与思考

介绍了作者在常微分方程教学中对案例教学所做的一些探索、实践与思考.     

关于输电阻塞管理问题的思考

对"电力市场的输电阻塞管理"这道竞赛题进行了研究,首先对问题背景进行了说明,然后就建模过程的关键点进行了详细的阐述,同时建立了简明合理的非线性优化模型.通过适当的数学处理,将非线性模型巧妙地转化为线性模型.     

关于21世纪数学类学生综合能力培养的思考

针对21世纪以来科学和技术的迅猛发展及社会对数学类学生提出的要求,对大学数学类学生综合能力培养的必要性进行了全面论述,详细分析了数学类学生综合能力培养存在的问题,提出了相应解决措施．     

关于数学建模的创新思维教学模式的探讨

提高大学生数学建模质量,不仅仅为了提高学生的数学建模成绩,更重要的是使学生在建模的过程中提高应用数学知识和方法分析和解决实际问题的能力.结合自己的教学体会,对教学过程中如何构建学生建模意识和提高培养学生的创新思维做了一些探讨.     

多媒体在《高等数学》教学中的实践与思考

数学的教学过程实际上是一种信息的传递过程 ,整个过程是由信息的拥有者、传递媒体和信息的接受者三方面组成 ,而接受信息则主要通过视觉、听觉获得 .几百年延续下来传统的《高等数学》教学方法大多是黑板加粉笔 ,有时附加一些挂图及模型 ,对课本内容边讲解边板演而完成 .它已成为人们最熟悉的教学方法 ,但是随着现代科学技术的迅速发展 ,人们对数学知识的需求日益递增 ,而大学生在校内学习时间有限性以及各专业教学改革及双休日制度与重大节日假期的延长 ,使得《高等数学》课程的教学学时不断被压缩 ,教学密度越来越大 ,课时尤为紧张 .又因…     

Efficiently Hex-Meshing Things with Topology

A topological quadrilateral mesh \(Q\) of a connected surface in \(\mathbb {R}^3\) can be extended to a topological hexahedral mesh of the interior domain \(\varOmega \) if and only if \(Q\) has an even number of quadrilaterals and no odd cycle in \(Q\) bounds a surface inside \(\varOmega \) . Moreover, if such a mesh exists, the required number of hexahedra is within a constant factor of the minimum number of tetrahedra in a triangulation of \(\varOmega \) that respects \(Q\) . Finally, if \(Q\) is given as a polyhedron in \(\mathbb {R}^3\) with quadrilateral facets, a topological hexahedral mesh of the polyhedron can be constructed in polynomial time if such a mesh exists. All our results extend to domains with disconnected boundaries. Our results naturally generalize results of Thurston, Mitchell, and Eppstein for genus-zero and bipartite meshes, for which the odd-cycle criterion is trivial.     

Perspectives on Advanced Mathematical Thinking

This article sets the stage for the following 3 articles. It opens with a brief history of attempts to characterize advanced mathematical thinking, beginning with the deliberations of the Advanced Mathematical Thinking Working Group of the International Group for the Psychology of Mathematics Education. It then locates the articles within 4 recurring themes: (a) the distinction between identifying kinds of thinking that might be regarded as advanced at any grade level, and taking as advanced any thinking about mathematical topics considered advanced; (b) the utility of characterizing such thinking for integrating the entire curriculum; (c) general tests, or criteria, for identifying advanced mathematical thinking; and (d) an emphasis on advancing mathematical practices. Finally, it points out some commonalities and differences among the 3 following articles.     

Universals: Ways or Things?

What all contemporary so-called aristotelian realists have in common has been identified by David Armstrong as the principle of instantiation. This principle has been put forward in different versions, but all of them have the following simple consequence in common: uninstantiated universals do not exist. Such entities are for the lotus-eating Platonist to countenance, but not for any sort of “moderate” realist. I shall argue that this principle, in any guise, is not the best way to differentiate aristotelianism from Platonism. In its place, I shall suggest that the best way to differentiate the two versions of realism from each other is by means of a far more powerful idea: naturalism. And the surprising conclusion given this means of differentiation will be that contrary to the usual proclamations, Platonism will be the more naturalistic theory, whereas aristotelianism will come to be seen for what it really is, namely, non-naturalistic.     

基于整体性思想的数据分析

通过对风险函数的分解,首先得到了传统上在独立同分布模型或线性模型假定下被忽视的度量复杂系统非线性程度的重要指标-扭曲度,然后对如何降低风险进行了讨论.逐步引出了干扰度、偏离度和信息分解比,它们与风险函数和扭曲度一起组成五个指标;最后权衡这五个指标,达到对稳定中心度量指标的控制.这也是用整体性思想进行数据分析的一种尝试.     

Cultural Influences on Children's Probabilistic Thinking

This study investigated selected cultural influences on probabilistic thinking of 11–12-year-old children in England. Language, beliefs and experience are shown to influence the children's “informal knowledge” of probability, i.e., the intuitive knowledge they bring to school and use in thinking about probabilistic situations presented in school. Some of the pupils' responses in interviews and in a questionnaire were consistent with the “outcome approach” and with the use of certain heuristics: “representativeness”; “availability”; “equiprobability.” A significant proportion of pupils revealed superstitions. Standard “random devices” such as dice were regarded by some children as subject to personal, religious or causative influences. In a comparison between two culturally-contrasted subgroups in the same school, we found significant differences in scores on probability tests, even when taking account of numerical and non-verbal ability. But the differences between the two groups could almost entirely be explained by differences in language ability.     

嵌入物联网信息采集影响PLM成本收益模型研究

将物联网信息采集技术引入到产品生命周期管理过程中,建立了PLM成本消耗模型,通过数学推理证明了引入物联网信息采集后的成本消耗能够更加节约.并列举算例和利用MATLAB仿真证明了这一结果.