包含测度的椭圆型方程解的Hlder连续性

考虑包含测度μ的椭圆型方程－ｄｉｖＡ（ｘ，ｕ，ｕ）＋Ｂ（ｘ，ｕ，ｕ）＝μ，在Ｇ内，ξ·Ａ（ｘ，ｕ，ξ）｜ξ｜ｐ－ｆ０（ｘ），１＜ｐ＜ｎ，｜Ａ（ｘ，ｕ，ξ）｜κ｜ξ｜ｐ－１＋ｆ１（ｘ），κ１，｜Ｂ（ｘ，ｕ，ξ）｜ｃ（ｘ）｜ξ｜γ＋ｆ２（ｘ），ｐ－１γｐ在γ＝ｐ－１的情况，为证有界解的Ｈｌｄｅｒ连续性，只需ｃ（ｘ）∈Ｌｎ（Ｇ）     

关于面积平均p叶函数（Ⅱ）

假设ｆ（ｚ）＝ｚ＾ｐ（１＋Σ＾∞ｎ＝１ａｎ＾ｚ＾ｎｋ）是△＝｛｜ｚ｜＜１｝内面积平均ｐ叶的（如果必要，△＝｛｜ｚ｜＜１｝＼（－１，０］）。本文的主要结论是：（１）如果设Ｍ（ｒ）＝ｍａｘ｜ｆ（ｚ）｜，则（１－ｒ）２ｐ／ｋＭ（ｒ）→αｋ≤１（ｒ→１），αｋ＝１的充要条件是ｆ（ｚ）＝ｚ＾ｐ（１－ｘｚ＾ｋ）＾－２ｐ／ｋ，｜ｘ｜＝１。进一步，如果１≤ｋ＜４ｐ，我们有｜ａｎ｜ｎ＾１－２ｐ／ｋ→αｋГ（２ｐ／ｋ     

消失Bergman—Carleson测度和小Bloch空间的特征

本文给出了消失Ｂｅｒｇｍａｎ－Ｃａｒｌｅｓｏｎ测度的一个特征，证明了：当ｆ∈Ｈ（Ｂ），０＜ｐ＜∞时，ｆ∈Ｂ０等价于ｌｉｍ｜ｚ｜→１｜Δｆ（ｚ）｜＝０，等价于ｌｉｍ｜ａ｜→１∫Ｂ｜Δｆ（ｚ）｜ｐＪＲφａ（ｚ）ｄｖ（ｚ）＝０，等价于Δｆ（ｚ）｜ｐｄｖ（ｚ）是消失Ｂｅｒｇｍａｎ－Ｃａｒｌｅｓｏｎ测度．     

一个反应扩散过程的门槛结果

本文讨论反应扩散方程Ｃａｕｃｈｙ问题（ｕｔ－△ｕ＝ｕ＾ｐ－ｕ＾ｐ－ｕ，Ｘ∈Ｒ＾ｎ，ｔ∈（０，Ｔ），ｕ（ｘ，０）＝ｕ０（ｘ）≥０，Ｘ∈Ｒ＾ｎ，解的整体存在性，渐近性质和Ｂｌｏｗ－ｕｐ问题，其中１＜ｑ＜ｐ＜ｎ＋２／ｎ－２，ｎ≥３或者１＜ｑ＜ｐ＋∞，ｎ＝２．得到门槛结果。     

非线性波动方程整体解存在的一个必要条件

该文给出了非线性波动方程ｕｎ＝△ｕ＋ｆ（ｕ），（ｆ（ｕ）＝ｕ＾ｐ，ｐ〉１）的Ｃａｕｃｈｙ问题在函数空间Ｃ＾ｋ０（Ｒ＾ｎ）的原点领域有古典整体解的一个必要条件：１／２（ｕ（０）＾２Ｌ２＋ｕｔ（０）＾２Ｌ２）－∫Ｒ＾ｎ∫＾ｕ００ｆ（ｓ）ｄｓｄｘ≤０，并且证明了１〈ｐ〈＾ｎ＾２＋ｎ＋２／ｎ（ｎ－１），ｎ≠１（ｎ＝１，１〈ｐ〈＋∞）古典解与广义解有相同的生命跨度，同时给出了生命跨度的上界估计。     

关于Fujita型反应扩散方程组的Cauchy问题

本文研究Ｆｕｊｉｔａ型反应扩散方程组ｕｔ－Δｕ＝α１｜ｕ｜ｑ１－１ｕ＋β１｜ｖ｜ｐ１－１ｖ，（ｘ∈ＲＮ，ｔ＞０），ｖｔ－Δｖ＝α２｜ｕ｜ｑ２－１ｕ＋β２｜ｖ｜ｐ２－１ｖ，ｕ（ｘ，０）＝ｕ０（ｘ）０，ｖ（ｘ，０）＝ｖ０（ｘ）０，（ｘ∈ＲＮ）Ｌｐ解的整体存在性和有限时间Ｂｌｏｗ ｕｐ问题．这里ｑｉ＞１，ｐｉ＞１（ｉ＝１，２），α１０，α２＞０，β１＞０，β２０，１ｐ＋∞．     

最佳L2局部逼近存在唯一的充分必要条件

本文给出了最佳Ｌ２局部逼近的存在唯一性定理，设ｆ∈Ｌ２（０，δ），Ｓｎ＝ｓｐａｎ（ｕ０，ｕ１，．．．Ｕｎ－１）Ｃ＾ｎ－１（０，δ），且ｄｅｔＷｎ（ｕ０，ｕ１，．．．ｕｎ－１；０）≠０，那么，当ｘ→０时，网（Ｐｘ（ｆ，Ｓｎ）收敛于Ｓｎ中某元素Ｐ０（ｆ，Ｓｎ）的充要条件为：ｆ＝Ｐｎ－１＋ｈ，其中Ｐｎ－１（ｔ）＝ｎ－１∑ｉ＝１ａｉｔｉ（ｈ，１）ｘ＝０（Ｘ＾ｎ），ｘ→０，且Ｐ０（ｆ，Ｓｎ）＝ＵＷ＾－１ｎＡ     

带粗糙核的多线性振荡奇异积分

本文考虑多线性算子ＴＡｆ（ｘ）＝∫ＲｎｅｉＰ（ｘ，ｙ）Ω（ｘ－ｙ）｜ｘ－ｙ｜ｎ＋ｍＲｍ＋１（Ａ；ｘ，ｙ）ｆ（ｙ）ｄｙ，ｎ２，其中Ｐ（ｘ，ｙ）是Ｒｎ×Ｒｎ中的实值多项式，Ω是零次齐次函数且满足ｍ阶消失性条件，Ｒｍ＋１（Ａ；ｘ，ｙ）＝Ａ（ｘ）－｜α｜ｍＤαＡ（ｙ）（ｘ－ｙ）α，对任何｜α｜＝ｍ，ＤαＡ∈ＢＭＯ（Ｒｎ）．证明了Ω∈Ｌｑ（Ｓｎ－１）且ｑ＞１时，对任何１＜ｐ＜∞，‖ＴＡｆ‖ｐＣ（ｎ，ｍ，ｐ，ｄｅｇＰ）｜α｜＝ｍ‖ＤαＡ‖ＢＭＯ‖ｆ‖ｐ     

EXISTENCE OF POSITIVE RADIAL SOLUTIONS FOR SOME QUASILINEAR ELLIPTIC EQUATIONSIN ANNULAR OMAINS

§１　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｉｓｐａｐｅｒｗｅｃｏｎｔｉｎｕｅｔｏｃｏｎｓｉｄｅｒｔｈｅｅｘｉｓｔｅｎｃｅｏｆｐｏｓｉｔｉｖｅｒａｄｉａｌｓｏｌｕｔｉｏｎｓｆｏｒｔｈｅｑｕａｓｉｌｉｎｅａｒｅｌｌｉｐｔｉｃｅｑｕａｔｉｏｎ－ｄｉｖ（｜Ｄｕ｜ｐ－２Ｄｕ）＝ｆ（ｕ）　ｉｎΩ,（１）ｕ（ｘ）＝０　ｏｎΩ,ｗｈｅｒｅｘ∈Ｒｎ,ｎ≥２,Ω＝｛ｘ：ａ＜｜ｘ｜＜ｂ,ａ,ｂ＞０｝,ａｎｄｐ＞１,ｆ∈Ｃ１（（０,∞））∩Ｃ０（［０,∞））ｓａｔｉｓｆｙｉｎｇｔｈｅｆｏｌｌｏｗｉｎｇｈｙｐｏｔｈｅｓｅｓ…     

具临界指数和临界非线性边界条件的拟线性椭圆型方程Neumann问题

本文给出ＲＮ（Ｎ３）中有界光滑区域Ω上的拟线性椭圆型方程：－∑Ｎｉ＝１ｘｉ·｜Ｄｕ｜ｐ－２ｕｘｉ＝λ｜ｕ｜ｐ－２ｕ＋ａ（ｘ）｜ｕ｜ｐ－２ｕ＋ｆ（ｘ，ｕ），ｘ∈Ω（λ＞０，ｐ＝Ｎｐ／（Ｎ－ｐ），２ｐ＜Ｎ）在边界条件：－｜Ｄｕ｜ｐ－２Ｄνｕ｜Ω＝ψ（ｘ）｜ｕ｜ｑ－２ｕ（ｑ＝（Ｎ－１）ｐ／（Ｎ－ｐ））下的多解性结果．     

Optimal control of nonlinear evolution inclusions

In this paper, we study the optimal control of nonlinear evolution inclusions. First, we prove the existence of admissible trajectories and then we show that the set that they form is relatively sequentially compact and in certain cases sequentially compact in an appropriate function space. Then, with the help of a convexity hypothesis and using Cesari's approach, we solve a general Lagrange optimal control problem. After that, we drop the convexity hypothesis and pass to the relaxed system, for which we prove the existence of optimal controls, we show that it has a value equal to that of the original one, and also we prove that the original trajectories are dense in an appropriate topology to the relaxed ones. Finally, we present an example of a nonlinear parabolic optimal control that illustrates the applicability of our results.This research was supported by NSF Grant No. DMS-88-02688.     

The Gergonne and Nagel centers of an n-dimensional simplex

In contrast with the analogous situation for a triangle, the cevians that join the vertices of a tetrahedron to the points where the faces touch the insphere (or the exspheres) are not concurrent in general. This observation led the present author and P. Walker in [4] to devise alternative definitions of the Gergonne and Nagel centers of a tetrahedron that do not assume the concurrence of such cevians and that coincide with the ordinary definitions in the case of a triangle. They then proved that the Gergonne center exists and is unique for all tetrahedra and that the Nagel center, though unique, exists only for tetrahedra that satisfy certain conditions. In this article, we extend these definitions to simplices of any dimension. By keeping the requirement that the Gergonne center be interior and relaxing such a condition for the Nagel center, we prove that both centers exist and are unique for all simplices, thus polishing the definitions and generalizing the results of the above-mentioned article.     

Some arguments against intentionalism

Recently, many have argued that phenomenal content supervenes on representational content; i.e. that the phenomenal character of an experience is wholly determined (metaphysically, not causally) by the representational content of that experience. This paper it identifies many counter-examples to intentionalism. Further, this paper shows that, if intentionalism were correct, that would require that an untenable form of representational atomism also be correct. Our argument works both against the idea that phenomenal content supervenes on “conceptual” content and also against the idea that it supervenes on “non-conceptual” content. It is also shown that the distinction between conceptual and non-conceptual content has been wrongly conceived as distinction between different kinds of information: in fact, it is a distinction between ways of packaging information that is, in itself, neither conceptual or non-conceptual.     

Are ‘misconceptions’ or alternative frameworks of force and motion spontaneous or formed prior to instruction?

It has often been assumed that misconceptions of force and motion are part of an alternative framework and that conceptual change takes place when that framework is challenged and replaced with the Newtonian framework. There have also been variations of this theme, such as this structure is not coherent and conceptual change does not involve the replacement of concepts, conceptions or ideas but consists of the development of scientific ideas that can exist alongside ideas of the everyday. This article argues that misconceptions (or preconceptions, intuitive ideas, synthetic models, p-prims etc.) may not be formed until the learner considers force and motion within the learning situation and reports on a classroom observation (that is replicated with similar results) that suggest misconceptions arise, not because of prior experience, but spontaneously in the attempt at making sense of the terms of the discourse. The implications are that misconceptions may not be preformed, that research ought to consider the possible spontaneity in the students’ reasoning and then, if possible, attempt to discern any preformed elements or antecedents, and that we ought to reconsider what is meant by ‘conceptual change’. The classroom observation also suggests gravity as a particular stumbling-block for students. The implications for further research are discussed.     

Star partitions on graphs

Given an undirected graph, a star partition is a partition of the nodes into subsets with at least two nodes so that the subgraph induced by each subset has a spanning star. Star partitions are related to well-known problems concerning domination in graphs and edge covering. We focus on the Constrained Star Partition Problem (CSP) that asks for finding a star partition of given cardinality. The problem is new and presents interesting peculiarities. We explore the relation between the cardinalities of star partitions and domatic bipartitions, showing that there are star partitions of any cardinality between minimum and maximum values, and that a similar but weaker result holds for domatic bipartitions. We study the computational complexity of different versions of star partition and domatic bipartition problems, proving that most of them, in particular CSP, constrained domatic bipartition and balanced domatic bipartition, are NP-complete. We also show that star partition problems are polynomial on trees and, more generally, on bounded treewidth graphs. We introduce an integer linear programming formulation that defines a polytope containing all the star partitions of a graph, showing that its vertices have only integral components for trees, which implies that linear programming can be used to solve weighted star partition problems on trees.     

The role of framing in productive classroom discussions: A case for teacher learning

In this paper, we contrast two mathematical arguments that occurred during an algebra lesson to illustrate the importance of relevant framings in the ensuing arguments. The lesson is taken from a graduate course for elementary teachers who are enrolled in a mathematics specialist program. We use constructs associated with enthnography of argumentation to characterize the framings for warrants and backings that supported the ensuing arguments. Our findings suggest that teachers fully participated in argumentations that were framed by problem situations that were familiar to them, ones that were couched in elementary, fundamental mathematical ideas, and that these types of argumentations were arguably more productive in terms of opportunities for learning.     

A Globally Convergent Smoothing Newton Method for Nonsmooth Equations and Its Application to Complementarity Problems

The complementarity problem is theoretically and practically useful, and has been used to study and formulate various equilibrium problems arising in economics and engineerings. Recently, for solving complementarity problems, various equivalent equation formulations have been proposed and seem attractive. However, such formulations have the difficulty that the equation arising from complementarity problems is typically nonsmooth. In this paper, we propose a new smoothing Newton method for nonsmooth equations. In our method, we use an approximation function that is smooth when the approximation parameter is positive, and which coincides with original nonsmooth function when the parameter takes zero. Then, we apply Newton's method for the equation that is equivalent to the original nonsmooth equation and that includes an approximation parameter as a variable. The proposed method has the advantage that it has only to deal with a smooth function at any iteration and that it never requires a procedure to decrease an approximation parameter. We show that the sequence generated by the proposed method is globally convergent to a solution, and that, under semismooth assumption, its convergence rate is superlinear. Moreover, we apply the method to nonlinear complementarity problems. Numerical results show that the proposed method is practically efficient.     

On the joint characterization of the distributions of the true income and the proportion of the reported income to the true income through a model of under-reported incomes

In this note, we assume that the reported income is related to the true income by the so-called ‘error-in-variables’ model, a model which assumes that the observed incomes are under-reported. In the context of this model, the distribution of the reported income suitably truncated below coincides with that of the true income, and suitable truncated above with that of the random proportion of the reported income to the true income if, and only if, the distribution of the true income is Pareto and that of the proportion is of the power function form.     

An integrated production and preventive maintenance planning model

We are given a set of items that must be produced in lots on a capacitated production system throughout a specified finite planning horizon. We assume that the production system is subject to random failures, and that any maintenance action carried out on the system, in a period, reduces the system’s available production capacity during that period. The objective is to find an integrated lot-sizing and preventive maintenance strategy of the system that satisfies the demand for all items over the entire horizon without backlogging, and which minimizes the expected sum of production and maintenance costs. We show how this problem can be formulated and solved as a multi-item capacitated lot-sizing problem on a system that is periodically renewed and minimally repaired at failure. We also provide an illustrative example that shows the steps to obtain an optimal integrated production and maintenance strategy.     

Attention to meaning by algebra teachers

Non-attendance to meaning by students is a prevalent phenomenon in school mathematics. Our goal is to investigate features of instruction that might account for this phenomenon. Drawing on a case study of two high school algebra teachers, we cite episodes from the classroom to illustrate particular teaching actions that de-emphasize meaning. We categorize these actions as pertaining to (a) purpose of new concepts, (b) distinctions in mathematics, (c) mathematical terminology, and (d) mathematical symbols. The specificity of the actions that we identify allows us to suggest several conjectures as to the impact of the teaching practices observed on student learning: that students will develop the belief that mathematics involves executing standard procedures much more than meaning and reasoning, that students will come to see mathematical definitions and results as coincidental or arbitrary, and that students’ treatment of symbols will be largely non-referential.