The Re-examination of Gibson Paradox

<正>From the beginning of the year,the price of gold has been constantly rising.On the parties in the Spring Festival,my relatives often talked about buying gold in order to invest.They also mentioned that due to the stable interest provided by the US,the price of gold would keep rising.I have learned that     

近代非线性回归在电力系统负荷短期预测中的应用

本文就河北省１９８５—１９９０年春节期间每小时用电量的统计数字用非线性回归模型（Ｇｏｍｐｅｒｔｄｚ）处理了６年中同日同一时间的耗电量，建立了回归模型，并预测了１９９１年同一时间的用电情况。实际表明本文的结果是可信的．     

具有跟踪隔离措施的新冠肺炎传播模型分析及应用

报道于2019年12月底的新型冠状病毒肺炎(COVID-19)疫情, 由于2020年春运期间人口的大规模流动, 使得其迅速蔓延.自2020年1月23日起, 我国采取了各种措施使得疫情得到了有效的控制, 例如武汉封城、确诊病例的密切接触者跟踪隔离、湖北人员的居家隔离等.该文基于COVID-19在山西省的实际传播情况, 建立了具有输入病例和确诊病例密切接触者跟踪隔离的动力学模型.在不考虑输入病例的情况下, 分析了模型的动力学行为.利用山西省COVID-19病例数据, 计算了实时再生数, 发现山西省2020 年1月25日全省封村封街道有效控制了COVID-19疫情的传播, 即实时再生数小于1, 从宏观角度验证了防控措施的有效性.进一步通过模型的数值拟合得到: 早期染病者隔离14天的防控策略是合理有效的; 武汉封城时间越早, 染病者的规模越小; 跟踪隔离到大量确诊病例的接触者时, 染病者的规模越小.     

The table placement problem: a research challenge at the EWI 2007

The table placement problem consists in deciding how to seat the participants attending a social lunch or dinner so that the total social benefit of the event is maximum. Four different approaches are presented: a linear model, a bin-packing-based-approach, a quadratic assignment problem, and a greedy heuristic. The different formulations are computationally compared over a set of artificial instances and on the real data for the EURO Winter Institute 2007 Gala dinner.     

Kaplansky test problem forR-modules

We prove that every ringR without strong decomposition theorem has a strong non-decomposition theorem. We use diamonds (but this will be eliminated in a subsequent paper). Publication number 381. The author would like to thank the BSF for partially supporting this research and Alice Leonhardt for the beautiful typing. The research was conducted in Spring ′87 and Spring ′88.     

GM(1,1)的周期修正模型及其在泉水流量预测中的应用

本文阐述了 GM( 1 ,1 )的残差周期修正模型 ,并将它应用于山西神头泉的流量预测中 ,建立了神头泉流量的 GM( 1 ,1 )周期修正模型 ,对其流量进行了预测 ,为神头泉域岩溶水资源开发利用和保护提供了科学依据     

基于时间序列与灰色拓扑的春节火灾损失预测

火灾每年给中国带来了巨大的损失,春节期间的火灾损失更是严重.根据1999-2010年春节期间火灾统计资料,火灾四项指标数据具有时序性以及随机波动性、模糊性.运用时间序列与灰色拓扑预测方法相结合预测春节期间火灾发生规律,且预测出未来3年内的火灾发生情况.结果表明,时间序列预测模型的平均绝对误差较小,且所建立的灰色拓扑预测模型的拟合精度都达到"好"的标准.因此,采用时间序列与灰色拓扑预测模型相结合对春节火灾发生情况进行预测,其结果合理可靠,可供理论研究和消防部门做出相应的预防措施参考,以达到有效控制和预防春节火灾的目的.     

Proximality and Chebyshev sets

This paper is a companion to a lecture given at the Prague Spring School in Analysis in April 2006. It highlights four distinct variational methods of proving that a finite dimensional Chebyshev set is convex and hopes to inspire renewed work on the open question of whether every Chebyshev set in Hilbert space is convex.     

带有提前购买价格折扣的易逝品库存模型

经典Newsboy模型是在购买价格不变的情形下去确定最优进货批量．然而,对于一些具有特定的消费时间的商品（如中秋节的月饼等）,生产厂家为了更好地安排生产,通常提供提前购买价格折扣．这样确定何时进货、进多少货的问题对经销商来说就显得非常重要．本文研究了该问题,并建立了带有提前购买价格折扣的易逝品的一个库存模型,同时也给出了应用实例与参数的灵敏度分析．     

The Arab Spring: A simple compartmental model for the dynamics of a revolution

We introduce a simple compartmental model for the dynamics of a revolution in dictatorial regimes that employ censorship and police repression. A defining property of the model is the use of visibility and policing terms that feature rapid transitions as a function of the size of the revolution, for which we provide conceptual and network-based mathematical justifications. The complete mathematical classification of the dynamical behaviour of the model leads to a division in parameter space that is interpreted naturally in terms of stability of the regime (stable police state, meta-stable police state, unstable police state, and failed state). We show that these dynamical properties of the model are generic for a broad class of visibility and policing functions that feature rapid transitions. We investigate how the model can be applied to the peaceful revolutions of the Arab Spring in Tunisia and Egypt, taking into account the influence of the Internet and new media on the visibility of the revolution and the ensuing reduced effectivity of censorship. Within the model this leads to significant, discontinuous changes in regime stability, which greatly increase the probability of realized revolutions. These properties of the model inform possible answers to questions on causes and timing of the Arab Spring revolutions, and the role of the Internet and new media. The broader relevance of the model classification is also investigated by applying it to the current political situation in some other countries with regimes that employ censorship and police repression.     

A combinatorial proof of a result of hetyei and reiner on Foata-Strehl-type permutation trees

We give a combinatorial proof of the known result that there are exactlyn!/3 permutations of lengthn in the minmax tree representation of which theith node is a leaf. This paper was written while the author was a one-term visitor at Mathematical Sciences Research Institute in Spring 1997. This visit was supported by an MIT Applied Mathematics Fellowship.     

Finite algorithm for generalized linear multiplicative programming

The nonconvex problem of minimizing the sum of a linear function and the product of two linear functions over a convex polyhedron is considered. A finite algorithm is proposed which either finds a global optimum or shows that the objective function is unbounded from below in the feasible region. This is done by means of a sequence of primal and/or dual simplex iterations.The first author gratefully acknowledges the research support received as Visiting Professor of the Dipartimento di Statistica e Matematica Applicata all' Economia, Universitá di Pisa, Pisa, Italy, Spring 1992.     

商代墓向的统计分析

本文采用系统聚类分析等方法 ,对河南、河北两省部分地域内发掘出的商代墓葬的方向进行统计分析发现 ,商代墓葬具有非常明显的埋葬规律性。并判断出这部分地域内商代墓葬的墓主人至少可归属于 1 3个主要族属。此结论恰好与《左传》定公四年记载的分鲁公和分康叔殷族属数之和相一致。     

On the regularity criteria for the 3D magnetohydrodynamic equations via two components in terms of BMO space

In this paper, we consider sufficient conditions for the regularity of Leray–Hopf solutions of the 3D incompressible magnetohydrodynamic equations via two components of the velocity and magnetic fields in terms of BMO spaces. We prove that if belongs to the space , then the solution (u,b) is regular. This extends recent results contained by Gala, Ji E and Lee J. Copyright © 2013 John Wiley & Sons, Ltd.     

Some comments on stabilizability

This paper discusses the robustness of exponentially stabilizable systems and the relationships between controllability and stabilizability. An absolute bound on the robustness index of a controlled system is obtained and an extension of Brockett's necessary conditions for stabilizability is also given.This research was supported by S.E.R.C. Contract No. GR/B/9116.7. The paper was completed in Spring 1985, when the author was with the Department of Mathematics, Heriot-Watt University, Edinburgh, Scotland.     

A social-event based approach to sentiment analysis of identities and behaviors in text

We describe a new methodology to infer sentiments held toward identities and behaviors from social events that we extract from a large corpus of newspaper text. Our approach draws on affect control theory, a mathematical model of how sentiment is encoded in social events and culturally shared views toward identities and behaviors. While most sentiment analysis approaches evaluate concepts on a single, evaluative dimension, our work extracts a three-dimensional sentiment “profile” for each concept. We can also infer when multiple sentiment profiles for a concept are likely to exist. We provide a case study of a large newspaper corpus on the Arab Spring, which helps to validate our approach.     

Book Reviews

Book reviewed in this article: Introduction to BASIC Programming Gary B. Shelly, Thomas J. Cash-man Teaching Kids Math Carne Barnett with Sharon Young Speaking of Numbers: Skillbuilding in English and Arithmetic Worktext 1 Daniel Rusthoi Silver Spring And So On: New Designs for Teaching Mathematics John V. Trivett Probability and Statistics with Reliability, Queuing, and Computer Science Applications Kishor Shridharbhai Trivedi     

Higher-order rigidity—What is the proper definition?

We show that there is a bar-and-joint frameworkG(p) which has a configurationp in the plane such that the component ofp in the space of all planar configurations ofG has a cusp atp. At the cusp point, the mechanismG(p) turns out to be third-order rigid in the sense that every third-order flex must have a trivial first-order component. The existence of a third-order rigid framework that is not rigid calls into question the whole notion of higher-order rigidity. Robert Connelly gratefully acknowledges the support of the Humboldt research award programme. Herman Servatius thanks the Mathematical Sciences Institute at Cornell for its invitation to a workshop in the Spring of 1991, where these problems were discussed.     

Modeling of a vehicle seat suspension system with pneumatic spring and viscous dampers

The paper contains physical and mathematical model of the passive system of seat suspension, used in trucks and buses. Spring force in this system is performed by air spring, whereas damping force is generated by two viscous dampers. Based on the experimental research of characteristic parts of the suspension system, the parameters of mathematical model are determined. Both results of computer simulations and experiments are presented as power spectral density of acceleration courses, measured on seat, in comparison with courses measured on excitation platform in laboratory. Transmissibility of real system and its model are also presented in the paper. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Scattering Operators for Matrix Zakharov-Shabat Systems

In this article the scattering matrix pertaining to the defocusing matrix Zakharov-Shabat system on the line is related to the scattering operator arising from time-dependent scattering theory. Further, the scattering data allowing for a unique retrieval of the potential in the defocusing matrix Zakharov-Shabat system are characterized. The research leading to this article was supported in part by the Italian Ministery of Education and Research (MIUR) under PRIN grant no. 2006017542-003, and by INdAM. One of the authors (CvdM) wishes to express his gratitude for the hospitality of the Department of Mathematics of the University of Texas at Arlington during the Spring Semester of 2008 when part of the paper was written.