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市场经济能自动实现均衡吗?——基于马克思主义政治经济学的逻辑 预览
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作者 赵磊 《西部论坛》 CSSCI 北大核心 2019年第2期1-7,20共8页
市场经济能否自动实现均衡的关键,在于供求失衡之后的经济波动是'正反馈'还是'负反馈'。历史证明,市场经济走向'正反馈'的趋势,乃是资本主义的常态。经济危机的结果,就是通过'暴力去产能'使得失衡的市... 市场经济能否自动实现均衡的关键,在于供求失衡之后的经济波动是'正反馈'还是'负反馈'。历史证明,市场经济走向'正反馈'的趋势,乃是资本主义的常态。经济危机的结果,就是通过'暴力去产能'使得失衡的市场供求被强制性地恢复均衡。离开'暴力'和'强制'的经济危机来谈'市场均衡',只能是'伪均衡'。晚近以来,虽然'市场均衡'理论已经为很多学者所证伪,但这些证伪工作大多并没有对'市场均衡'的基本逻辑提出反思。在本文中,笔者运用资本主义基本矛盾所导致的'有购买力的消费不足'理论,对市场经济的'伪均衡'做出批判性的分析。最后,笔者进一步讨论了'矛盾分析'与'均衡分析'的区别:二者的区别不仅在于对矛盾状态的定位不同,还在于二者的逻辑不同。换言之,'矛盾分析'是'辩证逻辑'的展开,而'均衡分析'则局限在'形式逻辑'里面兜圈子。 展开更多
关键词 均衡 均衡分析 矛盾分析 辩证逻辑 形式逻辑
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基于联立方程计量经济学模型的经济系统预测与控制方法 预览
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作者 王义闹 《温州大学学报:自然科学版》 2019年第1期1-8,共8页
对联立方程计量经济模型所描述的经济系统,由于随机干扰项的存在,系统不可能达到均衡.本文将数理经济学中均衡概念进行推广,提出了均值均衡的概念.证明了只要简化式模型存在,就一定存在均值均衡点;由最小二乘法估计简化式模型参数进而... 对联立方程计量经济模型所描述的经济系统,由于随机干扰项的存在,系统不可能达到均衡.本文将数理经济学中均衡概念进行推广,提出了均值均衡的概念.证明了只要简化式模型存在,就一定存在均值均衡点;由最小二乘法估计简化式模型参数进而可得均值均衡点的无偏估计.指出了当结构式模型存在过度识别方程时,用二阶段法求得结构参数,然后解(省略随机干扰项的)结构方程组求内生变量预测值的方法不一定能得到无偏估计.并讨论了系统中部分变量的控制方法. 展开更多
关键词 联立方程模型 预测 控制 均衡 均值均衡
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一种基于均衡的医疗资源配置求解方法 预览
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作者 鞠永和 王静成 +2 位作者 朱俊武 宋衡 陶立坚 《南京师大学报:自然科学版》 CAS CSCD 北大核心 2019年第2期30-36,共7页
在医疗系统中,医疗资源的配置通常以资源配置均衡和最大化医疗资源总体收益为目标.为了通用化模型,本文将医疗资源模型化为Agent,提出一种基于社会最优配置的Agent联盟收益均衡配置方法.首先,针对所有可能的联盟求得满足社会最优配置的A... 在医疗系统中,医疗资源的配置通常以资源配置均衡和最大化医疗资源总体收益为目标.为了通用化模型,本文将医疗资源模型化为Agent,提出一种基于社会最优配置的Agent联盟收益均衡配置方法.首先,针对所有可能的联盟求得满足社会最优配置的Agent分组;在均衡配置存在的条件下,使用不断迭代的方式使得个体Agent产生的收益逼近均衡配置状态,得到一个同时具备Agent配置均衡和总体收益最大化两个属性的配置解.在配置护士到病房的应用表明,本方法有效地得到了一个满足利益均衡的联盟策略与收益配置方案. 展开更多
关键词 医疗资源 结盟 均衡 社会最优 资源配置
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On-node lattices construction using partial Gauss–Hermite quadrature for the lattice Boltzmann method
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作者 叶欢锋 干则成 +1 位作者 匡波 杨燕华 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第5期175-180,共6页
A concise theoretical framework,the partial Gauss–Hermite quadrature (pGHQ),is established to construct on-node lattices of the lattice Boltzmann (LB) method under a Cartesian coordinate system.Compared with the exis... A concise theoretical framework,the partial Gauss–Hermite quadrature (pGHQ),is established to construct on-node lattices of the lattice Boltzmann (LB) method under a Cartesian coordinate system.Compared with the existing approaches,the pGHQ scheme has the following advantages: extremely concise algorithm,unifies the constructing procedure for symmetric and asymmetric on-node lattices,and covers a full-range quadrature degree of a given discrete velocity set.We employ the pGHQ scheme to search the local optimal and asymmetric lattices for {n = 3,4,5,6,7} moment degree equilibrium distribution discretization on the range [-10,10].The search reveals a surprising abundance of available lattices.Through a brief analysis,the discrete velocity set shows a significant influence on the positivity of equilibrium distributions,which is considered as one of the major impacts of the numerical stability of the LB method.Hence,the results of the pGHQ scheme lay a foundation for further investigations to improve the numerical stability of the LB method by modifying the discrete velocity set.It is also worth noting that pGHQ can be extended into the entropic LB model,even though it was proposed for the Hermite polynomial expansion LB theory. 展开更多
关键词 equilibrium distribution DISCRETIZATION PARTIAL Gauss–Hermite QUADRATURE
高铁车站到发线计划非常态调整模型与算法 预览
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作者 赵天蔚 《物流科技》 2019年第5期79-83,共5页
针对非常态下高铁车站组织作业秩序受到的影响,对高铁车站到发线计划实时调整进行研究。提出基于乘降因子的到发线计划调整方法,并对其可行性进行分析。以到发线计划乘降因子的波动性和均衡性最优为目标,构建高铁车站到发线计划实时调... 针对非常态下高铁车站组织作业秩序受到的影响,对高铁车站到发线计划实时调整进行研究。提出基于乘降因子的到发线计划调整方法,并对其可行性进行分析。以到发线计划乘降因子的波动性和均衡性最优为目标,构建高铁车站到发线计划实时调整模型问题,设计基于三种优先权规则的实时调整算法。最后通过算例验证该模型和算法的有效性,可为高铁车站到发线计划的实时调整提供有效依据。 展开更多
关键词 到发线计划 非常态调整 乘降因子 稳定性 均衡性
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Determination and correlation solubility of m-phenylenediamine in (methanol, ethanol, acetonitrile and water) and their binary solvents from 278.15 K to 313.15 K
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作者 Pengbao Lian Huipeng Zhao +3 位作者 Jianlong Wang Lizhen Chen Yong Xiang Qinghua Ren 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第5期1149-1158,共10页
In this study, the solubility of m-phenylenediamine in four pure solvents(methanol, ethanol, acetonitrile and water) and three binary solvent(methanol + water),(ethanol + water) and(acetonitrile + water) systems were ... In this study, the solubility of m-phenylenediamine in four pure solvents(methanol, ethanol, acetonitrile and water) and three binary solvent(methanol + water),(ethanol + water) and(acetonitrile + water) systems were determined in the temperature ranging from 278.15 K to 313.15 K by using the gravimetric method under atmospheric pressure. In the temperature range of 278.15 K to 313.15 K, the mole fraction solubility values of m-phenylenediamine in water, methanol, ethanol, and acetonitrile are 0.0093–0.1533, 0.1668–0.5589,0.1072–0.5356, and 0.1717–0.6438, respectively. At constant temperature and solvent composition, the mole fraction solubility of o-phenylenediamine in four pure solvents was increased as the following order:water b ethanol b methanol b acetonitrile;and in the three binary solvent mixtures could be ranked as follows:(ethanol + water) b(methanol + water) b(acetonitrile + water). The relationship between the experimental temperature and the solubility of m-phenylenediamine was revealed as follows: the solubility of mphenylenediamine in pure and binary solvents could be increased with the increase of temperature. The experimental values were correlated with the Jouyban–Acree model, van’t Hoff–Jouyban–Acree model, modified Apelblat–Jouyban–Acree model, Sun model and Ma model. The standard dissolution enthalpy, standard dissolution entropy and the Gibbs energy were calculated based on the experimental solubility data. In the binary solvent mixtures, the dissolution of m-phenylenediamine could be an endothermic process. The solubility data,correlation equations and thermodynamic property obtained from this study would be invoked as basic data and models regarding the purification and crystallization process of m-phenylenediamine. 展开更多
关键词 M-PHENYLENEDIAMINE SOLUBILITY SOLID-LIQUID equilibrium Jouyban-Acree model THERMODYNAMIC property
Solid-Liquid Phase Equilibria in the Aqueous System Containing Potassium, Magnesium, and Borate at 308.15 K 预览
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作者 SHI Chun-cheng YANG Juan +3 位作者 WANG Shi-qiang ZHAO Dong GUO Ya-fei DENG Tian-long 《盐湖研究》 CSCD 2019年第2期78-84,共7页
Experimental studies on the solubility, density, refractive index, and pH value in the aqueous system containing potassium, magnesium, and borate at 308.15 K were determined with the method of isothermal dissolution e... Experimental studies on the solubility, density, refractive index, and pH value in the aqueous system containing potassium, magnesium, and borate at 308.15 K were determined with the method of isothermal dissolution equilibrium. Based on the experimental results, the diagrams of solubility, density, refractive index, and pH value in this system were plotted. We found that there were one eutectic point and two crystallization regions corresponding to the large area of inderite (L + Mg2B6O11·15H2O) and the relatively small area of potassium borate tetrahydrate (L + K2B4O7 ·4H2O), respectively. Neither double salt nor solid solution was found in this system. The physicochemical properties (density, refractive index, and pH value) in solution at 308.15 K changed regularly with increasing potassium borate concentration. The calculated values of density and refractive index using empirical equations of the aqueous system were in good agreement with the experimental values. 展开更多
关键词 Stable PHASE equilibrium PHASE DIAGRAM SOLUBILITY PHYSICOCHEMICAL property
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Seismic stability of earth slopes with tension crack
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作者 Yundong ZHOU Fei ZHANG +2 位作者 Jingquan Wang Yufeng GAO Guangyu DAI 《结构与土木工程前沿:英文版》 EI CSCD 2019年第4期950-964,共15页
Cracks at the crest of slopes frequently occur during earthquakes. Such cracks result from limited tension strength of the soil. A tension cut-off in Mohr-Coulomb shear strength can represent this limited strength. Pr... Cracks at the crest of slopes frequently occur during earthquakes. Such cracks result from limited tension strength of the soil. A tension cut-off in Mohr-Coulomb shear strength can represent this limited strength. Presented is an extension of variational analysis of slope stability with a tension crack considering seismicity. Both translational and rotational failure mechanisms are included in a pseudo-static analysis of slope stability. Developed is a closed-form to assess the seismic stability of slopes with zero tensile strength. The results indicate that the presence of the tension crack has significant effects on the seismic stability of slopes, i.e., leading to small value of the yield acceleration. Considering soil tension strength in seismic slope analysis may lead to overestimation on the stability, as much as 50% for vertical slopes. Imposing tension crack results in transit of the critical failure mode to a straight line from a log-spiral, except for flat slopes with small soil cohesion. Under seismic conditions, large cohesion may increase the depth of crack, moving it closer to the slope. 展开更多
关键词 SLOPE stability tension CRACK LIMIT EQUILIBRIUM SEISMIC effect
邯郸市农业用水结构时空变化特征及用水预测分析 预览
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作者 尚瑞朝 李苏 徐丹 《人民珠江》 2019年第10期66-72,136共8页
用水结构的时空变化特征及其合理性分析是水资源优化配置及水资源可持续利用的前提,鉴此,采用信息熵、均衡度、洛伦兹曲线及基尼系数等方法对邯郸市农业用水结构的时空变化特征进行分析,并采用定额法进一步对农田灌溉用水量进行预测。... 用水结构的时空变化特征及其合理性分析是水资源优化配置及水资源可持续利用的前提,鉴此,采用信息熵、均衡度、洛伦兹曲线及基尼系数等方法对邯郸市农业用水结构的时空变化特征进行分析,并采用定额法进一步对农田灌溉用水量进行预测。结果表明,由现状用水结构可知,农业用水量占总用水量的70%左右,农田灌溉用水量较大;从用水结构时间上分析,农业用水结构的信息熵呈先降低后增长的趋势,均衡性越来越强;从空间上分析,农田灌溉用水的空间分布较林牧渔业均匀;尽管农业用水结构朝着均衡的方向发展,但从用水量方面仍需对农业用水结构优化,经预测2020-2030水平年农田灌溉用水量明显减少,2020年农田灌溉用水量为14.92亿m^3,2030年为13.87亿m^3;农业用水结构的研究是对于水资源供需矛盾及水资源优化配置的良好决策,可为水资源可持续发展起支撑作用。 展开更多
关键词 用水结构 信息熵 均衡度 洛伦兹曲线 基尼系数 用水预测
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Association of Variations in the Dynamics of the Lithosphere with Sea Temperature 预览
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作者 Nabil H.Swedan 《地质研究(英文)》 2019年第1期12-20,共9页
Variations in the dynamics of the oceanic lithosphere are important at the societal and research levels because geological activities are associated with these variations. At any given section of the lithosphere, the ... Variations in the dynamics of the oceanic lithosphere are important at the societal and research levels because geological activities are associated with these variations. At any given section of the lithosphere, the time in which its typical geophysical parameters vary is considerably smaller than section's age. The lithosphere can, therefore, be assumed to proceed from one state of dynamic equilibrium to another displaced deferentially. When these conditions are accounted for in the thermal analysis of the oceanic lithosphere, the earth's internal heat flux through the lithosphere is found to be an adiabatic invariant. Lithosphere physical parameters exhibit constant change and linearity. These findings simplify analysis of heat and work inter actions between oceanic lithosphere and continents, lithosphere dynamics, and deep mantle heat transfer. The temperature of the solid earth remains unchanged for the foreseeable future, and variations in sea temperature vary the intensity of geological activities. If sea temperature increases, the geological activities increase and vice versa. Relevant equations are derived using this thermal analysis of the lithosphere and validated based on observations and the work of others. In addition, the analysis reveals that the eleven-year solar constant cycle is capable of inducing 1.56×10^16 J yr^-1 of geological activities. 展开更多
关键词 LITHOSPHERE Dynamic EQUILIBRIUM FOURIER Equation Climate Change SEASONAL VARIATIONS Solar CONSTANT
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MIL-101(Cr)开式吸附性能实验 预览
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作者 李倩文 赵惠忠 +2 位作者 王朝阳 吴天浩 张敏 《化工进展》 EI CAS CSCD 北大核心 2019年第8期3788-3794,共7页
采用水热合成法制备水热稳定金属有机骨架MIL-101(Cr),基于太阳能吸附式空气取水选取不同的实验工况,将MIL-101(Cr)、细孔硅胶作为研究对象,相对湿度控制在50%、温度范围5~45℃条件下,测试并对比了MIL-101(Cr)与细孔硅胶的吸附性能。实... 采用水热合成法制备水热稳定金属有机骨架MIL-101(Cr),基于太阳能吸附式空气取水选取不同的实验工况,将MIL-101(Cr)、细孔硅胶作为研究对象,相对湿度控制在50%、温度范围5~45℃条件下,测试并对比了MIL-101(Cr)与细孔硅胶的吸附性能。实验表明,35℃、50%RH条件下,吸附过程进行1000min,MIL-101(Cr)水吸附量为22.05g/100g,其吸附量相比细孔硅胶提高93%左右;当系统平衡时,MIL-101(Cr)有效平均吸附速率相比细孔硅胶提高120%左右。此外,在相对湿度(RH) 50%、温度范围5~45℃条件下,MIL-101(Cr)的平衡吸附量在11.40~23.47g/100g之间。在所控温度下,MIL-101(Cr)在25℃时平衡吸附量最大,在5℃时平衡吸附量最小,25℃时MIL-101(Cr)的平衡吸附量相比5℃时提高106%左右。该实验可以为四季工况不同温度下MIL-101(Cr)用于太阳能吸附式空气取水提供基础数据。 展开更多
关键词 MIL-101(Cr) 太阳能 吸附 平衡 吸附量 空气取水
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一类具有一般出生函数阶段结构的传染病模型的全局分析
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作者 王玉萍 李建全 蔺小林 《数学的实践与认识》 北大核心 2019年第17期313-318,共6页
假设种群个体生长分幼年和成年两个阶段以及疾病仅在成年阶段传播,建立并研究了一类幼年个体输入率为一般函数的传染病模型,得到了决定种群存活与否的种群存活基本再生数和决定疾病传播灭绝与否的疾病传播基本再生数,通过构造适当的Lyap... 假设种群个体生长分幼年和成年两个阶段以及疾病仅在成年阶段传播,建立并研究了一类幼年个体输入率为一般函数的传染病模型,得到了决定种群存活与否的种群存活基本再生数和决定疾病传播灭绝与否的疾病传播基本再生数,通过构造适当的Lyapunov函数分析了模型的全局阈值动力学性态. 展开更多
关键词 阶段结构 传染病模型 平衡点 全局渐近稳定性 基本再生数
高质量发展问题研究 预览
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作者 魏凤娟 《经济研究导刊》 2019年第29期7-11,14共6页
高质量发展,从宏观层面看,经济发展更可持续、经济结构更加平衡(包括区域发展更加平衡、产业结构更加合理)即为高质量发展;从微观层面看,企业能为消费者供给更可靠质量的产品和更温馨满意的服务即为高质量供给;从社会层面看,政府能为广... 高质量发展,从宏观层面看,经济发展更可持续、经济结构更加平衡(包括区域发展更加平衡、产业结构更加合理)即为高质量发展;从微观层面看,企业能为消费者供给更可靠质量的产品和更温馨满意的服务即为高质量供给;从社会层面看,政府能为广大人民提供更满意的公共服务即为高质量服务。研究高质量发展,既有理论指导意义,又有实践探索价值。 展开更多
关键词 质量 发展 均衡 协调
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Spherical to truncated octahedral shape transformation of palladium nanocrystals driven by e-beam in aqueous solution
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作者 Yingying Jiang Xiao Li +5 位作者 Xiaoming Ma Haifeng Wang Hui Zhang Zheng Liu Ze Zhang Chuanhong Jin 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第10期2623-2627,共5页
The crystallographic shapes of nano crystals play critical roles in determi ning their physical and chemical properties.Liquid phase synthesis serves as one of the most importa nt approaches for preparing shape-contro... The crystallographic shapes of nano crystals play critical roles in determi ning their physical and chemical properties.Liquid phase synthesis serves as one of the most importa nt approaches for preparing shape-controlled nano crystals,therefore,understa nding the formation mecha nisms of the thermod yn amic equilibrium structures of nano crystals in liquid soluti on is importa nt.Using in situ liquid cell tran smissi on electron microscopy(TEM),we observe for the first time the shape transformation of individual palladium nanocrystals from energy unfavored spherical shapes into equilibrium truncated octahedrons in aqueous solution.Via quantitative analysis of the shape evolution dynamics of an individual Pd nano crystal,we find that about 10%of nano crystal atoms were relocated during the shape tran sformation.The mass tran sport is attributed to the synergetic effect of electron beam irradiation and water environment. 展开更多
关键词 equilibrium shape Pd nanocrystals shape transformation dynamics liquid cell transmission electron microscopy(TEM)
悬浮床加氢脱硫尾气水蒸气转化制氢热力学 预览
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作者 杨程 黄传峰 +3 位作者 赵丽信 李伟 杨天华 朱永红 《化工进展》 EI CAS CSCD 北大核心 2019年第S01期33-38,共6页
以悬浮床加氢脱硫尾气为水蒸气转化制氢原料,采用改进的原子序数矩阵法构建了包含6个独立反应的化学反应体系。分别考察各个独立反应在不同反应温度下,标准摩尔反应焓、吉布斯自由能变及平衡常数的变化规律;借助HYSYS流程模拟软件中的GI... 以悬浮床加氢脱硫尾气为水蒸气转化制氢原料,采用改进的原子序数矩阵法构建了包含6个独立反应的化学反应体系。分别考察各个独立反应在不同反应温度下,标准摩尔反应焓、吉布斯自由能变及平衡常数的变化规律;借助HYSYS流程模拟软件中的GIBBS反应器,研究反应器出口温度、反应压力及水碳物质的量之比对产物平衡组成的影响。热力学研究结果表明:烷烃碳数越高,水蒸气转化反应的平衡常数、吉布斯自由能变和标准摩尔焓对温度的敏感性越高,达到相同转化效果所需的反应温度越低。HYSYS模拟确定该体系下最适宜的反应条件为反应器出口温度700℃、反应压力100kPa、水碳物质的量之比4。 展开更多
关键词 制氢 热力学 模拟 平衡 水蒸气转化
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基于心理作用和治疗的SIS传染病模型的渐近分析
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作者 傅金波 《生物数学学报》 2019年第1期125-130,共6页
根据传染病动力学原理,考虑到传染病的发生,人们将采取相应的预防和控制措施,建立了基于心理作用和治疗的SIS传染病模型.综合利用常微分方程定性与稳定性理论和极限系统理论,分别获得了该模型的无病平衡点和地方病平衡点全局渐近稳定的... 根据传染病动力学原理,考虑到传染病的发生,人们将采取相应的预防和控制措施,建立了基于心理作用和治疗的SIS传染病模型.综合利用常微分方程定性与稳定性理论和极限系统理论,分别获得了该模型的无病平衡点和地方病平衡点全局渐近稳定的充分条件.研究结果表明:人们心理作用的积极影响,能够书疾病的传播和流行控制在一定范围内,加上有效的治疗措施,甚至能够加快疾病的绝灭. 展开更多
关键词 SIS传染病模型 心理作用 治疗 平衡点 全局渐近稳定性
具有饱和发生率的血吸虫病动力学分析
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作者 王晓红 薛亚奎 《数学的实践与认识》 北大核心 2019年第8期249-257,共9页
血吸虫病是我国一种严重的寄生虫病,并且在湖北、安徽、湖南、江苏、四川和云南成地方病.结合中国血吸虫病的现状及特点,考虑人群、牛群以及水环境中的钉螺、尾蚴和毛蚴之间的相互传染,建立了具有饱和发生率的血吸虫病动力学模型,给出... 血吸虫病是我国一种严重的寄生虫病,并且在湖北、安徽、湖南、江苏、四川和云南成地方病.结合中国血吸虫病的现状及特点,考虑人群、牛群以及水环境中的钉螺、尾蚴和毛蚴之间的相互传染,建立了具有饱和发生率的血吸虫病动力学模型,给出了模型的基本再生数.通过构造Lyapunov函数证明了当基本再生数小于1时,模型的无病平衡点全局渐近稳定;当基本再生数大于1时,模型的地方病平衡点也是全局渐近稳定的.最后,利用数值模拟验证了理论结果. 展开更多
关键词 血吸虫病 基本再生数 平衡点 全局稳定性
VECTORIAL EKELAND VARIATIONAL PRINCIPLE AND CYCLICALLY ANTIMONOTONE EQUILIBRIUM PROBLEMS 预览
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作者 丘京辉 《数学物理学报:B辑英文版》 SCIE CSCD 2019年第2期524-544,共21页
In this article, we extend the cyclic antimonotonicity from scalar bifunctions to vector bifunctions. We find out a cyclically antimonotone vector bifunction can be regarded as a family of cyclically antimonotone scal... In this article, we extend the cyclic antimonotonicity from scalar bifunctions to vector bifunctions. We find out a cyclically antimonotone vector bifunction can be regarded as a family of cyclically antimonotone scalar bifunctions. Using a pre-order principle(see Qiu, 2014), we prove a new version of Ekeland variational principle(briefly, denoted by EVP), which is quite different from the previous ones, for the objective function consists of a family of scalar functions. From the new version, we deduce several vectorial EVPs for cyclically antimonotone equilibrium problems, which extend and improve the previous results. By developing the original method proposed by Castellani and Giuli, we deduce a number of existence results(no matter scalar-valued case,or vector-valued case), when the feasible set is a sequentially compact topological space or a countably compact topological space. Finally, we propose a general coercivity condition. Combining the general coercivity condition and the obtained existence results with compactness conditions, we obtain several existence results for equilibrium problems in noncompact settings. 展开更多
关键词 EQUILIBRIUM problem: cyclic antimonotonicity vectorial EKELAND VARIATIONAL principle sequentially COMPACT TOPOLOGICAL SPACE countably COMPACT TOPOLOGICAL SPACE
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What Determines China's Grain Imports and Self-sufficiency? The Role of Rising Domestic Costs and Varying World Market Prices
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作者 Wusheng Yu Tianxiang Li Jing Zhu 《中国与世界经济:英文版》 2019年第5期1-24,共24页
China s grain sectors have faced unprecedented challenges in recent years as the ever-increasing and historically high level of grain output has failed to reduce grain imports. On the contrary, high grain imports and ... China s grain sectors have faced unprecedented challenges in recent years as the ever-increasing and historically high level of grain output has failed to reduce grain imports. On the contrary, high grain imports and high domestic stock have accompanied historically high domestic output, a situation dubbed the "triple high" phenomenon in current policy discussion. This paper explores the role of widening domestic-world market price gaps in determining the triple high phenomenon.Unlike earlier studies that relied on production capacities, this paper argues that domestic production and demand (hence imports) are functions of domestic and world market prices and proposes an analytical framework to explicitly capture such price gaps under restricted trade linkages in general equilibrium. Following this approach, a set of price scenarios for the 2011-2020 period are constructed and simulated in a computable general equilibrium model. Results from the core scenarios, in which recent domestic and world market price trends are assumed to continue, suggest that further widening price gaps would substantially increase grain imports and reduce domestic output (by 60 million tons) and self-sufficiency ratios from base levels. In the alternative scenarios with larger (smaller) price gaps, we find higher (lower) imports and larger (smaller) decreases in domestic output and self-sufficiency ratios. Such results provide important policy implications as China's agricultural policy undergoes significant adjustment. 展开更多
关键词 computable general equilibrium model domestic-world market price GAPS food security GRAIN IMPORTS SELF-SUFFICIENCY ratio triple high
Competitive Cloud Pricing for Long-Term Revenue Maximization
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作者 Jiang Rong Tao Qin Bo An 《计算机科学技术学报:英文版》 SCIE EI CSCD 2019年第3期645-656,共12页
We study the pricing policy optimization problem for cloud providers while considering three properties of the real-world market:1)providers have only incomplete information about the market;2)it is in evolution due t... We study the pricing policy optimization problem for cloud providers while considering three properties of the real-world market:1)providers have only incomplete information about the market;2)it is in evolution due to the increasing number of users and decreasing marginal cost of providers:3)it is fully competitive because of providers'and users'revenuedriven nature.As far as we know,there is no existing work investigating the optimal pricing policies under such realistic settings.We first propose a comprehensive model for the real-world cloud inarket and formulatc it as a stochastic game.Then we use the Markov perfect equilibrium(MPE)to describe providers5 optimal policies.Next we decompose the problem of computing the MPE into two subtasks:1)dividing the stochastic game into many normal-formal games and calculating their Nash equilibria,for which we develop an algorithm ensuring to converge,and 2)computing the MPE of the original game,which is efficiently solved by an algorithm combining the Nash equilibria based on a mild assumption.Experimental results show that our algorithms are efficient for computing MPE and the MPE strategy leads to much higher profits for providers compared with existing policies. 展开更多
关键词 CLOUD computing Markov PERFECT equilibrium game theory REVENUE MAXIMIZATION
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