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1.
1 IntroductionWe consider tlie variational inequality problelll, deuoted by VIP(X, F), wliicli is to find avector x* E X such thatF(X*)"(X -- X-) 2 0, VX E X, (1)where F: R" - R" is any vector-valued f11uction and X is a uonelllpty subset of R'.This problem has important applicatiolls. in equilibriun1 modeIs arising in fields such asecououtics, transportatioll scieuce alld operations research. See [1]. There exist mauy lllethodsfor solviug tlie variational li1equality problem VIP(X. …  相似文献   

2.
1 IntroductionLet F, be a fiuite field witl1 q elelllents. wl1ere q is a power of 2. We will follow tlie notationsand terntillologies in [11. LetThe singular pseudthsymplectic group with respect to Se,I over Fq denoted by PS=.+.+..=.+, (F,)is defiued to be tlie group fOrnled by all (2P + 6 + l) x (2v + b + l) nonsingUlar n1atrices T suchthat TSb.,T' == Sb,i. wl1ere TT denotes the transpose of T. If T 6 Ps=.+,+,.=.+, (Fq), then T isof the forlllwhere T1,S,T1,' = Se and T22 is nousin…  相似文献   

3.
1 IntroductionIn this paPer, we are interested in tlie time-asymptotic behavior of solutions to isentropicNavier-stokes equations in even space-dimensions. Recently many people began to study it'sasymptotic behavier when time is large enough. This can be manifested in tlie after refer-ences. For the pointwise estimate of solution to generaJ hyperbolic-parabolic systems in onespace dimension see Liu and Zeng[']. In several space variables, Kawashima[31 has studiedgeneral hyperbolic-parabolic…  相似文献   

4.
1 IntroductionWe have iIltroduced the fuzzy nlodular category Pm in the reference [1] alld thell cOI1-structed son1e kinds of fuzzy quotiellt n1odule in the reference [2l and [3l. Furtllernlore wediscussed the concepts of tlie exact sequeIlces of Linear maps in Fm and obtained 1naIly iInpor-taIlt conclusions in the reference [4]. It is a bright idea to illvestigate the algebric structure ofFln by means of homological algebra. We illtroduce Honl functors and Tensor fu1lctors iIl Fm i11thi…  相似文献   

5.
1 IntroductionLet fl be a simply connected bounded domain in R2 with a smooth boundary 0fl. Considerthe two-dimensional Robin problemwhere k denotes differentiation aIong the inward pointing normal to 0n and 7 is a positiv('constan. Denote its eigenvalues, counted according to multiplicity, byZayed alld Hassall[15'16] l1ave discussed the probleln (1. 1)-(1.2) fOr small / large impedance7 and have determned some geometric quantities of the don1ain n, using tl1e asymptotic ex-pansion of tlie s…  相似文献   

6.
1 IntroductionLet fl be a boulided regular domain in n". By regUlar domain we understand any domainof finite measure for which tlie estli11ates fOr Hodge decomposition in (2.6) and (2.7) are justilied.See, fOr example, N, [7], [2]. A Lipscl1tiz dolllain, for example,is regular.We consider solutionsiL Of a quasi1inear second order equation:divA(x, Vu) = 0, (1.1)where A: fl x n" - n" satisfies the usua1 nreasuability conditions(Caratheodory conditions)and that fOr sonle 1 < p < x,the follo…  相似文献   

7.
1 IntroductionIn this paper we deal with the oscilIatory behaviour of solutions of nonlinear third orderdifferential equations of tlie formandwhere pt q E C([a,co),R) la E R, f E C(R,R) such that ap 3 g > 0 for V / 0 and 7 > 0 isa quotient of odd integers.By a proper solutiOn of (1) or (2) we mean a solution y of the equation which exi8ts on somehalf line [Tg, oo) 5 [a, oo), where Tv depens on y, and is llontirivial in some neighbourhood ofinfinity that is y(t) / 0 in [t., oo) fOr some t…  相似文献   

8.
A CLASS OF BIDIMENSIONAL NONSEPARABLEWAVELET PACKETS   总被引:1,自引:0,他引:1  
1 IntroductionIn [1], CoifnThu, Meyer, alld Wickerhauser introduced orthogonal wavelet packets for L'(R)and. by using tensor products, collstructed orthogonal wave1et packets iu L'(R'). In [2], Chuial1d Li studied l1onorthogonal wave1et packets and tlieir dual wavelet packets in tlie u11ivariatecase, tl1us generalizing the ortllorgonal wavelet packets of [1]. Ill [3], Slien constructed noutensorwavelet packets in L'(R' ). Applicatious Of wavelet packets in signal processing and compressi…  相似文献   

9.
1 Introduction and Mds ResultsMathematical modeling of physical systems Often leads to nonlinear evolution equations.EXat solutions of such equations axe of haPortance in physical problexns, and in Particu1arthere is considerable interest in solitary wave solutiOns and soliton solutions. In this paPer, wepresent tlie solitary wave and sOliton sOlutions Of a fiftli order nonlillear evolution eqllation.Suppose u(x, t) satisfies fOllowing nonlinear 5th-order evolutiOn equation Of the fOrmut…  相似文献   

10.
1. IntroductionLet n be a bounded domain in AN with smooth boundary Off. We consider thefollowing initial boundary value problem:where 6, p are positive constants and "o(x) is a nonnegative bounded continuous function on fi.When N = 1 and 5 ~ 2, the problem arises in a model for the resistive diffusion of aforce--free magnetic field in a plasma confined between two walls in one dimension (see[5], [8], [9], [10] and [14]). Equation (1) also describes the evolution of the curvatureof a locally…  相似文献   

11.
Slope is a fundamental mathematics concept in middle and high school that transcends to the university level. An understanding of slope is needed at the university level since slope plays an important role in understanding problems involving variation and change. In this study Mexican curricula documents were examined to determine which conceptualizations of slope are addressed in the intended mathematics curriculum. To explain the results, we use conceptualizations of slope identified in previous research. Our findings reveal that, to a certain extent, the conceptualizations proposed in the Mexican intended mathematics curriculum differ slightly in terms of the emphasis and timing of instruction from what others have identified in the U.S., with slope as a geometric ratio receiving less emphasis in the Mexican curriculum. There was also noted discontinuity within the Mexican curriculum in introducing slope in grade 9 and subsequently introducing of linear functions in grade 10 without explicit mention of slope. Suggestions are made for future studies, both to consider the conceptualizations of slope promoted in the Mexican textbooks and the impact they have in classroom instruction and student learning of slope.  相似文献   

12.
This paper reports an attempt to improve results in the mathematics course in one of the architecture colleges in Israel through practise in applications. The effect of integrating structure design problems in the calculus curriculum on students' achievements and attitudes was examined. The applied topics in the curriculum were connected to calculus topics and studied through problembased learning activities. The integrated curriculum was implemented and the learning results in experimental and control groups were assessed by means of achievement tests, attitude questionnaires and student interviews. The learning achievements in the experimental group proved to be significantly higher than in the control group. The positive impact of learning applications on motivation, understanding, creativity and interest in mathematics is indicated.  相似文献   

13.
There is general agreement in Australia and beyond that quantitative skills (QS) in science, the ability to use mathematics and statistics in context, are important for science. QS in the life sciences are becoming ever more important as these sciences become more quantitative. Consequently, undergraduates studying the life sciences require better QS than at any time in the past. Ways in which mathematics and science academics are working together to build the QS of their undergraduate science students, together with the mathematics and statistics needed or desired in a science degree, are reported on in this paper. The emphasis is on the life sciences. Forty-eight academics from eleven Australian and two USA universities were interviewed about QS in science. Information is presented on: what QS academics want in their undergraduate science students; who is teaching QS; how mathematics and science departments work together to build QS in science and implications for building the QS of science students. This information leads to suggestions for improvement in QS within a science curriculum.  相似文献   

14.
Recent studies draw attention on the highly specialized capacity of human beings in recognizing altruists versus cheaters in social interactions. These results hint at the existence of specialized abilities that support discriminating behavior in strategic interactions. In this paper, we explore the implications of discriminating behavior in the study of the indirect evolutionary selection of selfish versus altruistic motivations in the context of generic 2×2 base games, and in particular for coordination and cooperation scenarios. We find that inequality averse (Rawlsian) altruism can enforce under rather general conditions socially optimal outcomes, including cases where selfishness cannot, such as in prisoner’s dilemmas. Inequality seeking (Nietzschian) altruism in no case improves upon Rawlsian altruism in terms of social optimality of outcomes, and often does worse. In the cooperation scenario in particular, Nietzschean altruism never manages to implement the cooperative outcome. Under perfect discrimination, moreover, inequality averse (Rawlsian) altruism often evolves at the expense of selfishness. These results suggest that the development of sophisticated discrimination abilities may be strongly adaptive in supporting fairness-oriented forms of pro-sociality in humans in the context of social dilemmas and coordination problems.  相似文献   

15.
This paper deals with the problematic aspect of the reconstruction of binary relations: it includes all the questions raising the possibility or impossibility to determine a structure by gathering given substructures. It is the continuation of three studies: the first made by G. Lopez [9] in 1972 about the determination of a binary relation through the types of isomorphism of its restrictions, the second made by K. B. Reid and C. Thomassen [15] in 1976 about the strongly self-complementary tournaments (every subtournament is self-complementary), the third made by C. Thomassen [16] in 1989 about the cycle space of a tournament. In the second section, we use the notion of class of difference (which was introduced in [9]) to extend a study made in [16] to binary relations. Then, in the third section, we improve the result of this last study in the case of the tournaments. After noticing that the result of [15] inferred itself naturally from the approach developed in [9], we extend, in the fourth section, the study made in [15] to binary relations.  相似文献   

16.
李勇军  江莹 《运筹与管理》2021,30(11):60-64
小学教育是教育阶段的基础,也是我国强制教育的一部分。但如何在各省份性别比例相差较大的情况下,更加有效的提高各省份小学教育资源配置效率是一个值得思考的问题。为了避免性别带来的影响,可以通过平行结构DEA模型根据学生性别分为两个平行子系统,来衡量我国2012~2018年各省份小学教育的资源配置情况。研究发现大部分省份小学教育资源配置的总系统效率未达到有效边界,仍有需要改进的地方。男学生在小学教育阶段的效率通常优于女学生在小学教育阶段的效率,但随着近些年我国教育体制的日益完善,女学生在小学教育阶段的效率呈上升趋势。此外,我国西部地区的小学教育资源配置效率在一些年份普遍优于东部和中部地区,而中部地区和东部地区小学教育总系统效率相对稳定,西部地区小学教育总系统效率波动较大。  相似文献   

17.
A mathematical model and numerical simulations corresponding to severe slugging in air-water pipeline-riser systems are presented. The mathematical model considers continuity equations for liquid and gas phases, with a simplified momentum equation for the mixture. A drift-flux model, evaluated for the local conditions in the riser, is used as a closure law. In many models appearing in the literature, propagation of pressure waves is neglected both in the pipeline and in the riser. Besides, variations of void fraction in the stratified flow in the pipeline are also neglected and the void fraction obtained from the stationary state is used in the simulations. This paper shows an improvement in a model previously published by the author, including inertial effects. In the riser, inertial terms are taken into account by using the rigid water-hammer approximation. In the pipeline, the local acceleration of the water and gas phases are included in the momentum equations for stratified flow, allowing to calculate the instantaneous values of pressure drop and void fraction. The developed model predicts the location of the liquid accumulation front in the pipeline and the liquid level in the riser, so it is possible to determine which type of severe slugging occurs in the system. A comparison is made with experimental results published in literature including a choke valve and gas injection at the bottom of the riser, showing very good results for slugging cycle and stability maps. Simulations were also made assessing the effect of different strategies to mitigate severe slugging, such as choking, gas injection and increase in separation pressure, showing correct trends.  相似文献   

18.
研究火灾发生规律及发展趋势,具有实用价值.分析历年中国火灾统计数据,发现中国火灾的发生规律同时具有增长趋势性和周期波动性特征:①中国火灾从90年代开始大幅度增加,在2002年达到最大,然后逐年缓慢下降;②每年12个月呈正弦函数波动,周期为12,1、2月发生起数最大,8、9月最小.借助于M ATLAB软件,根据2000-2006年中国火灾统计数据,建立火灾的月发生起数的非线性周期性组合预测模型,预测值与实际值的平均相对误差小于0.07.研究结论为消防研究、消防部门决策提供科学依据.  相似文献   

19.
Employing stochastic differential equations to model wildlife motion   总被引:7,自引:0,他引:7  
The concern is with the properties of stochastic differential equations (SDEs) describing the motion of particles in 3 dimensional space, on the sphere or in the plane. There is consideration of the case where the drift function comes from a potential function. There is study of SDEs whose parameters are periodic in time. These are useful for incorporating circadian rhythm in the behavior. The cases of a seal in a frozen lake in Alaska, an elephant seal migrating a great distance in the Pacific Ocean and of a group of "free-ranging" elk in a reserve in Oregon are referred to. For the elk nonparametric estimates of the drift and variance terms of an SDE model are discussed and evaluated and the fit of the model assessed. One issue is how to include explanatories, beyond location and time, in the model. A number of questions motivated by the wildlife motion concerning diffusion processes of the type considered are posed at the end of the paper. Received: 25 April 2002  相似文献   

20.
In this article, we analyse the incidence of excess weight in 24- to 65-year-old residents in the region of Valencia, Spain, and predict its behaviour in the coming years. In addition, we present some possible strategies to prevent the spread of the obesity epidemic.

We use classical logistic regression analysis to find out that a sedentary lifestyle and unhealthy nutritional habits are the most important causes of obesity in the 24- to 65-year-old population in Valencia. We propose a new mathematical model of epidemiological type to predict the incidence of excess weight in this population in the coming years. Based on the mathematical model sensitivity analysis, some possible general strategies to reverse the increasing trend of obesity are suggested.

The obese population in the region of Valencia is increasing (11.6% in 2000 and 13.48% in 2005) and the future is worrisome. Our model predicts that 15.52% of the population in Valencia will be obese by 2011. Model sensitivity analysis suggests that obesity prevention strategies (healthy advertising campaigns) are more effective than obesity treatment strategies (physical activity) involving the obese and overweight subpopulation in controlling the increase of adulthood obesity in the region of Valencia.  相似文献   

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