南方集体林区贮木场原木库存随机预报模型的研究

本主要论述应用多变量CAR模型预报南方集体林区贮木场原木库存量动态变化，并用计算机模拟。结果表明该方法模型预报精度高，且应用方便。     

齐民友先生谈数学教育改革──在PMN全国会议上的讲话(摘要)

这个会非常重要，我很高兴，主动来参加这个会．近年在国内，关于教育方面的种种问题都在考虑，不仅在中国，在美国也一样，例如在加州围绕教学改革，打了一场"数学之战"，最近这一年我与华中师大路刚同志谈的较多，无锡的徐沥泉老师，试着把数学方法论用于数学教学，做了很好的工作，数学教学问题的研究，郁很大的发展，英藉匈牙利人拉卡托斯，通过研究多面体的欧拉公式，以此为素材，为案例，搞助探论（heuristic，康宏逵先生的译法是准确的，有人译为探索法，亦可，译成"启发法"就在些勉强了），起初在一个杂志登出来，后来他的学生把它…     

对一目五行统一弃双九法的探讨

中国是算盘的故乡，珠算在中国有着悠久的历史，现在是计算机时代，但算盘仍是我国的计算工具，它在计算工作中仍显示出一定的优越性。因为，它擅长于加减，在各行各业的日常计算中，加减占绝大部分。     

应重视解题教学的“三步曲”──审题·表述·反思

G·波利亚曾经说过：“数学技能就是解题能力——不仅能解决一般的问题，而且能解决需要某种程度的独立思考，判断力，独创性和想象力的问题”．在某种意义上讲，高中数学教学的重点是解题教学．然而，在教学中我们常会碰到这样的情况，有的学生一听就会，但一解就错．在高考中，教师认为不难的问题的错误率反而高，究其原因，多数学生在平时的学习中没有真正做到在解题前仔细审题，左右推敲，在解题中不注意合理科学的表述，解题后根本没有反思的习惯，从而造成在考试中丢掉了不该失掉的冤枉分．因此，在解题教学中，我们必须重视强化解题…     

三角函数的教学实践

在三角函数的教学中，由于公式繁多，使得学生在开初学习时，会产生一些畏难情绪．进而，在学习之中，学生又会因为不善于分片、分系统地对于三角函数公式进行总结整理，总会觉得公式太多，杂乱无章，不易掌握，不易记忆．犹如满地珠贝，熠熠跃眼，只可惜难能瞬息全收．为...     

一般形式的一阶椭圆型偏微分方程组拟线性Riemann-Hilbert问题

在文［ｌ，２，３］中，Ｅ．Ｗｅｇｅｒｔ和Ｌ．Ｖ．Ｗｏｌｆｅｒｓｄｏｒｆ等人讨论了一类全纯函数的拟线性Ｒｉｅｍａｎｎ－Ｈｉｌｂｅｒｔ 问题在 Ｈａｒｄｙ空间中的可解性，在文［４］中，讨论了广义解析函数的拟线性 Ｒｉｅｍａｎｎ－Ｈｉｌｂｅｒｔ问题，同样得到该边值问题在Ｈ２类解空间中的可解性、本文在前面研究工作的基础上，对一般形式的一阶椭圆型偏微分方程组拟线性Ｒｉｅｍａｎｎ－Ｈｉｌｂｅｒｔ问题作了更深入的讨论，在适当的假设条件下，应用积分算子理论，函数论方法及不动点原理，证明了该边值问题在相应的泛函空间中同样是可解的．     

从误解中管窥“以形解数”——对一个高考热点问题的剖析

已知函数f（x）=Asin（ωx＋φ）在一个周期的图像，求ω，φ的值，是高考的热点问题，能充分考查学生的数形结合思想和转化与化归思想．此种题型大部分是由课本习题改编而来．最近，在复习课时，一道课本习题的解答，在学生中产生了很大的争议，看似十分合理的解法，但结果错了，而且不知错在哪里？本文展示出来，以期引起重视!     

何畏：简单可信赖

这是一个典型的北京姑娘，说着嘎嘣脆的北京话，做事爽快，没有一丝扭捏。何畏说自己是个经历简单的人，生在北京长在北京，在这里读书、工作、生活，没有波澜壮阔，更没有大起大落，稳稳当当的，但这并不妨碍她在30出头的时候就成了百度公司的内审部负责人，要知道这家在纳斯达克上市的互联网公司，可是全球最大的中文搜索引擎，目前市值高达255亿人民币。     

服饰上的几何点缀

出大事了，几何这个调皮鬼竟然不好好在家居界待着，跑我们身上来了，还信誓旦旦地立志要在服饰界闯出一片新天地。它这股冲动的劲儿，可是谁都拦不住啊。几何在家居界的成就，我们还是非常认可的，可在服饰界……唉，不管它是不是来捣乱的，我们先去瞧瞧吧！     

把计算机引入概率统计课教学的探讨与实践

随着教学改革的不断深入，改革传统的教学方式，采用多煤体组合进行教学已提到日程上来，在高科技蓬勃发展的今天，用计算机媒体辅助教学引起了人们普遍关注，在高等数学和线性代数的教学中引入计算机辅助已取得了很大的成就，几年来，我们在概率统计课的教学中对如何引用计算机辅助进行探索，并在93，94级部分班级进行了试点，收到了理想的效果，我们是从下面两个方面引入的。     

Programmed interactions in higher-order neural networks: The outer-product algorithm

Recent results on the memory storage capacity of the outer-product algorithm indicate that the algorithm stores of the order of n/log n memories in a network of n fully interconnected linear threshold elements when it is required that each memory be exactly recovered from a probe which is close enough to it. In this paper a rigourous analysis is presented of generalizations of the outer-product algorithm to higher-order networks of densely interconnected polynomial thresh-old units of degree d. Precise notions of memory storage capacity are formulated, and it is demonstrated that both static and dynamic storage capacities of all variants of the outer-product algorithm of degree d are of the order of n^d/log n.     

On the Asymptotic Behavior of the Storage Process Fed by a Markov Modulated Brownian Motion

Consider a storage model fed by a Markov modulated Brownian motion. We prove that the stationary distribution of the model exits and that the running maximum of the storage process over the interval [0, t] grows asymptotically like log t as t→∞.     

A FAST SINE TRANSFORM ALGORITHM FOR TOEPLITZ MATRICES AND ITS APPLICATIONS

In this paper, a fast algorithm for the discrete sine transform(DST) of a Toeplitz matrix of order N is derived. Only O(N log N) O(M) time is needed for the computation of M elements. The auxiliary storage requirement is O(N). An application of the new fast algorithm is also discussed.     

Dynamic storage allocation with known durations

This paper is concerned with a new version of on-line storage allocation in which the durations of all processes are known at their arrival time. This version of the problem is motivated by applications in communication networks and has not been studied previously. We provide an on-line algorithm for the problem with a competitive ratio of O(min{log Δ,log τ}), where Δ is the ratio between the longest and shortest duration of a process, and τ is the maximum number of concurrent active processes that have different durations. For the special case where all durations are powers of two, the competitive ratio achieved is O(loglog Δ).     

A fast numerical method for block lower triangular Toeplitz with dense Toeplitz blocks system with applications to time-space fractional diffusion equations

Based on the circulant-and-skew-circulant representation of Toeplitz matrix inversion and the divide-and-conquer technique, a fast numerical method is developed for solving N-by-N block lower triangular Toeplitz with M-by-M dense Toeplitz blocks system with \(\mathcal {O}(MN\log N(\log N+\log M))\) complexity and \(\mathcal {O}(NM)\) storage. Moreover, the method is employed for solving the linear system that arises from compact finite difference scheme for time-space fractional diffusion equations with significant speedup. Numerical examples are given to show the efficiency of the proposed method.     

An O(T log T) Algorithm for the Dynamic Lot Size Problem with Limited Storage and Linear Costs

In this paper the dynamic lot size problem with time varying storage capacities and linear costs is addressed. Like in the uncapacitated version, this problem can be formulated as a network flow problem. Considering the properties of the underlying network, we devise an O(T log T) greedy algorithm to obtain optimal policies and we report computational results for randomly generated problems.     

The measure problem for rectangular ranges in d-space

Klee recently posed the question: find an efficient algorithm for computing the measure of a set of n intervals on the line, and the analog for n hyperrectangles (ranges) in d-space. The one-dimensional case is easily solved in O(n log n) and Bentley has proved an O(n^d?1log n) algorithm for dimension d ≥ 2. We present an algorithm for Klee's measure problem that has a worst-case running time of only O(n^d?1) for d?3. While Bentley's algorithm is based on segment trees and requires only linear storage for any dimension, the new method is based on quad-trees and requires quadratic storage for d > 2.     

Range Searching and Point Location among Fat Objects

We present a data structure that can store a set of disjoint fat objects ind-space such that point location and bounded-size range searching with arbitrarily shaped ranges can be performed efficiently. The structure can deal with either arbitrary (fat) convex objects or nonconvex (fat) polytopes. The multipurpose data structure supports point location and range searching queries in timeO(log^d−1 n) and requiresO(n log^d−1 n) storage, afterO(n log^d−1 n log log n) preprocessing. The data structure and query algorithm are rather simple.     

Decomposition of Log Crepant Birational Morphisms between Log Terminal Surfaces

We prove that every log crepant birational morphism between log terminal surfaces can be decomposed into log flopping type divisorial contraction morphisms and log blowdowns. Repeating these two kinds of contractions, we reach a minimal log minimal surface from any log minimal surface.     

Log‐symmetric regression models: information criteria and application to movie business and industry data with economic implications

This work deals with log‐symmetric regression models, which are particularly useful when the response variable is continuous, strictly positive, and following an asymmetric distribution, with the possibility of modeling atypical observations by means of robust estimation. In these regression models, the distribution of the random errors is a member of the log‐symmetric family, which is composed by the log‐contaminated‐normal, log‐hyperbolic, log‐normal, log‐power‐exponential, log‐slash and log‐Student‐t distributions, among others. One way to select the best family member in log‐symmetric regression models is using information criteria. In this paper, we formulate log‐symmetric regression models and conduct a Monte Carlo simulation study to investigate the accuracy of popular information criteria, as Akaike, Bayesian, and Hannan‐Quinn, and their respective corrected versions to choose adequate log‐symmetric regressions models. As a business application, a movie data set assembled by authors is analyzed to compare and obtain the best possible log‐symmetric regression model for box offices. The results provide relevant information for model selection criteria in log‐symmetric regressions and for the movie industry. Economic implications of our study are discussed after the numerical illustrations.