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1.
罗党 《数学季刊》2000,15(4):74-79
本文作者考虑了一维Navier-Stokes方程组Cauchy问题,得到了其经典解的整体光滑可解性。  相似文献   

2.
考虑具耗散项的一维磁流体力学方程组Cauchy问题.对于非耗散情形证明了如果初始能量和磁场强度弱于声波的能量,则Cauchy问题的光滑解在有限时间内破裂;对于耗散情形,如果初始能量、磁场强度和耗散强度弱于声波的能量,则Cauchy问题的光滑解在有限时间内破裂,而且给出了生命区间估计.  相似文献   

3.
研究了三维可压等熵Euler方程Cauchy问题光滑解的整体存在性.如果初值是一个常状态的小扰动并且初速度的旋度等于零,证明了三维可压等熵Euler方程Cauchy问题光滑解的整体存在性.  相似文献   

4.
叶耀军 《数学学报》2006,49(4):927-940
本文证明了一类半线性波动方程组Cauchy问题整体解的存在唯一性.特别地,证明了自相似解的存在唯一性.同时还得到了渐近自相似解.  相似文献   

5.
利用拟线性双曲型方程组极值原理,改进了HSIAO Ling和D.Serre得到的关于多孔介质中可压缩流体力学方程组解的存在性结果,给出了其Cauchy问题的一个关于经典解整体存在和破裂的完整结果.这些结果说明强耗散有助于“小”解的光滑性.  相似文献   

6.
考虑具衰减记忆项的枯弹性材料中一类非线性方程组的Cauchy问题,在"大"初值条件下证明了经典解的整体存在性,给出了解在有限时间内产生奇性的充分条件,结果表明记忆具有耗散效应.  相似文献   

7.
考虑三维Wigner-Poisson方程组的Cauchy问题,将WP问题转化为等价的Schrodinger  相似文献   

8.
一类非局部反应扩散方程组Cauchy问题的临界爆破指标   总被引:4,自引:0,他引:4  
张丽琴 《数学研究》2001,34(2):136-141
证明了一类来源于燃烧理论的非局部反应扩散方程组Cauchy问题解的局部存在性、唯一性及临界爆破指标的存在性。并证明临界爆破指标属于爆破情形。  相似文献   

9.
本文应用调和分析的方法研究了一类非线性Schrodinger方程Cauchy问题整体自相似解的存在唯一性.  相似文献   

10.
In this paper we study solvability of the Cauchy problem of the Kawahara equation 偏导dtu + au偏导dzu + β偏导d^3xu +γ偏导d^5xu = 0 with L^2 initial data. By working on the Bourgain space X^r,s(R^2) associated with this equation, we prove that the Cauchy problem of the Kawahara equation is locally solvable if initial data belong to H^r(R) and -1 〈 r ≤ 0. This result combined with the energy conservation law of the Kawahara equation yields that global solutions exist if initial data belong to L^2(R).  相似文献   

11.
彭忠益  王艳 《运筹与管理》2020,29(7):144-155
定量的评判城市老旧居住小区整体交通环境质量并进而科学有效的提出老旧小区交通环境更新与改善措施,对城市老旧居住小区交通环境进行了调查,明确了老旧居住小区存在的突出交通问题,并提出了城市老旧居住小区交通环境评价的指标体系,包括行人跨路出行指数、无人行道路段长度占比、停车泊位供需比、路内非法停车占比、平均停车步行距离、泊位数量户数比、人均步行空间、无障碍通道、盲道设置比例、非机动车泊位供需比、地面停放车辆数小区面积比、外部穿行交通周转量小区面积比等。并给出了具体指标的计算方法与获得办法。以长沙市四个典型老旧居住小区为例,对评价方法进行了论证,并得到城市老旧居住小区存在的一般问题,包括人车混杂、人车交织现象严重,停车泊位短缺、车辆乱停乱放,交通设施、特别是弱势群体交通设施缺乏。给出的评价指标、评价方法与结论可为城市老旧小区改造更新,特别是其中很重要的交通环境更新提供决策依据。  相似文献   

12.
针对乡村绿色生态旅游特征,并考虑旅游者个体感受与群体效益,本文从乡村绿色生态旅游开发与适宜评级概念出发,提出乡村绿色生态旅游适宜等级VIKOR评估模型与方法。首先,从等级评估的概念与内涵出发,刻画乡村绿色生态旅游适宜评级问题,避免混淆旅游适宜评级和排序两个本质不同的问题。然后,构建乡村绿色生态旅游适宜等级评估指标及隶属函数,提出评估指标的熵权确定方法。其次,提出乡村绿色生态旅游适宜等级VIKOR评估模型与二元语义等级评估方法。最后,通过案例研究和比较分析,说明本文所提模型与方法的合理性、可行性与实用性。  相似文献   

13.
A generalization of both the hierarchical product and the Cartesian product of graphs is introduced and some of its properties are studied. We call it the generalized hierarchical product. In fact, the obtained graphs turn out to be subgraphs of the Cartesian product of the corresponding factors. Thus, some well-known properties of this product, such as a good connectivity, reduced mean distance, radius and diameter, simple routing algorithms and some optimal communication protocols, are inherited by the generalized hierarchical product. Besides some of these properties, in this paper we study the spectrum, the existence of Hamiltonian cycles, the chromatic number and index, and the connectivity of the generalized hierarchical product.  相似文献   

14.
耿申  乔晗 《运筹与管理》2022,31(10):169-175
为测度环境治理政策波动对产出、减排、要素配置、消费与产业结构的影响及其传导机制,将异质性消费偏好、产出差异性、环境效用和环境损失函数引入E-DSGE模型。政策强度分析发现,技术进步、排污税和消费税政策效果较强,环境控制和治污支出冲击效果较弱。政策效应分析发现,技术进步政策效应最优,能实现增产和减排双重目标,促进要素配置和居民消费、产出与消费结构改进;排污税和政府治污支出政策次优,能实现增产和减排的双赢目标,促进要素供给和产出结构清洁化,不利于消费提升和消费结构优化;环境控制与消费税政策效果最差,以牺牲产出实现减排,不利于要素配置,产出与消费结构改进效果较弱,消费税会抑制居民消费,但消费税政策效果随环境友好型家庭比例提升而加强。  相似文献   

15.
随机市场需求且受制造商减排水平影响,考虑碳限额与交易机制,研究制造商进行单纯银行借贷和供应商投资持股的组合融资时的最优决策和利润情况,分析消费者低碳偏好、碳交易价格和供应商的投资持股比例对供应链的最优决策变量和利润的影响。研究发现:无资金约束、单纯银行借贷和组合融资下,消费者低碳偏好、碳交易价格和持股比例与制造商的减排水平和利润以及供应链系统的利润正相关,而供应商的批发价格和制造商的生产量与消费者低碳偏好正相关,与碳交易价格负相关,而持股比例与供应商的批发价格负相关,与制造商的生产量和减排水平正相关;持股策略下制造商的减排水平和生产量最大,无资金约束时次之,单纯银行借贷时最小;而无资金约束时供应商的批发价格最高,单纯银行借贷时次之,持股策略时最低;在持股比例满足一定条件下,供应商和制造商的利润优于单纯银行借贷时的利润,并且可以优于无资金约束时的利润,提高了供应链的竞争力和效率。  相似文献   

16.
周文 《运筹与管理》2020,29(1):209-222
为恰当评估房地产业对中国经济的重要性,通过编制2002、2007和2012年中国社会核算矩阵,进行乘数分解和结构化路径分析的结果表明:房地产业对行业总产出、劳动力和资本报酬、居民和企业收入的拉动作用极低。房地产业主要对金融业、租赁和商务服务业、建筑业以及金属冶炼与压延加工业四个行业的产出影响比较显著,对前三个行业主要是直接的一步式影响,与房地产业紧密相关的产业链条并不长。房地产业对要素报酬和机构收入的拉动总效应极小,且主要是开环效应,与此同时,房地产业主要通过自身和金融业影响要素报酬进而影响机构收入,特别是对资本报酬和企业收入的影响简单、直接,高度依赖这两条基础路径。土地出让金和房地产有关税收已成为地方政府的主要收入来源。房地产开发和运营商、金融机构和地方政府已成为房地产业发展过程中最主要的利益相关方。  相似文献   

17.
The dynamics of damage and of the relaxing force in amorpho-crystalline polymers under constant strain are calculated using the formulas for the probability of rupture of a deformed polymer molecule and a model representation of amorphous interlayers. The main parameters of the model are the maximum and minimum possible deformations of molecular chains, the energy of rupture activation, the function of the chain length distribution, the temperature, the macroscopic strain, and the relative dimensions of the amorphous interlayer. The conformity of the theoretical model and the association of the relaxation spectrum with the internal molecular and structural characteristics of the material are established.Zhambyl Technical Institute of Light and Food Industry, Taraz, Kazakhstan. Translated from Mekhanika Kompozitnykh Materialov, Vol. 35, No. 4, pp. 499–508, July–August, 1999.  相似文献   

18.
赵焕焕  菅利荣  刘勇 《运筹与管理》2020,29(10):190-197
复杂装备研制主体间呈现社会关系、合作关系、协调关系等网络关系,并且相互影响相互作用,其影响复杂装备研制的重要参数。为有效描述在资源环境约束下制造商和供应商的关系,探讨复杂装备研制协调机理与实现路径,本文利用超网络方法,设计了相互影响、相互作用的社会关系网络、协调网络和合作网络的复杂装备研制协调超网络,并将社会关系水平、协调度和合作水平作为超网络的3个决策变量,建立基于关系价值最大、协调成本最低、协调风险最小、合作收益最大、合作风险最小和成本最小等不同偏好下的多目标最优决策模型,构建了复杂装备研制超网络均衡模型,并利用其探讨超网络均衡和实现路径。  相似文献   

19.
In this paper, we report on an experimental activity for discussing the concepts of speed, instantaneous speed and acceleration, generally introduced in first year university courses of calculus or physics. Rather than developing the ideas of calculus and using them to explain these basic concepts for the study of motion, we led 82 first year university students through Galileo's experiments designed to investigate the motion of falling bodies, and his geometrical explanation of his results, via simple dynamic geometric applets designed with GeoGebra. Our goal was to enhance the students’ development of mathematical thinking. Through a scholarship of teaching and learning study design, we captured data from students before, during and after the activity. Findings suggest that the historical development presented to the students helped to show the growth and evolution of the ideas and made visible authentic ways of thinking mathematically. Importantly, the activity prompted students to question and rethink what they knew about speed and acceleration, and also to appreciate the novel concepts of instantaneous speed and acceleration at which Galileo arrived.  相似文献   

20.
Nepotism has been the primary influence on political behavior throughout human history. Despite the spread of democracy in the 20th century, nepotistic regimes have hardly disappeared. Nepotism heavily influences political activity throughout the developing world, Middle East, and central Asia where family ties are essential for gaining access to power, state resources, and privileges. Rebelling against such nepotistic regimes is difficult and risky. RiskTaker is an agent-based model we developed for testing the influences of various social forces on risk taking behavior, including the formulation of rebellious coalitions. We use RiskTaker to examine the influence of nepotism on the distribution of wealth and social status. Nepotism heavily skews the distribution of wealth and status, leading to the formation of opposing coalitions and exacerbating social unrest.This paper was tied for Best Paper, NAACSOS (North American Association for Computational Social and Organizational Science) Annual Conference 2005, June 26–28, Notre Dame. Robert Sedlmeyer, Department of Computer Science, Indiana University – Purdue University, Fort Wayne provided programming for the RiskTaker model. Lawrence A. Kuznar is a professor of anthropology and director of the Decision Sciences and Theory Institute at Indiana University—Purdue University, Fort Wayne. He has conducted fieldwork among Aymara Indians in Andean Peru and the Navajo of the American southwest. His research interests include computer modeling, theories of risk taking and conflict, terrorism, social evolution, and scientific epistemology. He has authored articles in Ecological Economics (with W. Frederick), Current Anthropology, American Anthropologist, Mathematical Anthropology and Culture Theory and Journal of Anthropological Research, and published two books (Awatimarka Harcourt Brace, 1995 and Reclaiming a Scientific Anthropology Altamira Press, 1997) and two edited volumes. William Frederick has served as a faculty member in the departments of mathematical sciences and the department of computer sciences at Indiana University—Purdue University, Fort Wayne since 1979. His primary interests include mathematical modeling, game theory, and genetic algorithms.  相似文献   

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