一类生化反应动力系统的定性分析

随着微分动力学的发展,其作为一种研究实际问题的一种重要工具,已经渗透到各个领域,特别是生物化学领域.应用微分方程定性理论研究一类生化反应模型,对奇点进行了分类,给出了奇点周围极限环的不存在性存在性的充分条件.完善了此类微分动力系统的定性分析.     

完全扩容图的点圈扩张性

目的讨论了完全扩容图的圈扩张性。阿勇嘎在2011年给出了完全扩容图的概念，完全扩容图是G□L（G）唯一的非平凡分支，其中L（G）是G的线图。方法利用归纳法对其进行讨论。结果与结论对于最小度大于2的连通且局部连通的完全扩容图，它的任一点由所在的一个6-圈经过若干次1或2-扩张，最后得到哈密顿圈。     

异质性条件下的杠杆周期行为:基于资产价格视角的研究

本文在杠杆异质性条件下构建包含两类杠杆投资者、一类非杠杆投资者的金融系统动态模型,从风险资产价格角度分析了金融机构投资者杠杆的周期性特征,并以2006年到2015年中国上市银行和证券公司的季度数据为样本,采用动态面板模型进行了实证分析.结果表明,杠杆异质性的存在可以降低金融机构的目标杠杆,有利于金融系统稳定;金融机构杠杆相对于资产价格表现出明显的顺周期性特征,但不同类型金融机构之间的杠杆顺周期行为具有明显差异;证券公司杠杆随股票价格的变化程度明显大于银行杠杆,银行杠杆随房地产价格变化的顺周期行为比证券公司杠杆更为显著;两者在股票价格和房地产价格大涨大跌时期的杠杆调整方向亦不相同.论文研究结论为金融机构灵活运用杠杆工具和监管当局完善监管体系提供了新的理论思路和经验证据.     

The Euro‐Sting Revisited: The Usefulness of Financial Indicators to Obtain Euro Area GDP Forecasts

This paper uses an extension of the Euro‐Sting single‐index dynamic factor model to construct short‐term forecasts of quarterly GDP growth for the euro area by accounting for financial variables as leading indicators. From a simulated real‐time exercise, the model is used to investigate the forecasting accuracy across the different phases of the business cycle. Our extension is also used to evaluate the relative forecasting ability of the two most reliable business cycle surveys for the euro area: the PMI and the ESI. We show that the latter produces more accurate GDP forecasts than the former. Finally, the proposed model is also characterized by its great ability to capture the European business cycle, as well as the probabilities of expansion and/or contraction periods. Copyright © 2014 John Wiley & Sons, Ltd.     

高射频转管武器电启动分析

运用键合空间理论,分析了高射频转管武器启动系统的机电耦合动态特性,建立了启动系统的键合空间模型及其矢量状态方程组,计算得到了直流他励、直流串励电机在直接启动、降压启动和变阻启动下系统的耦合特性,为转管武器实验样机的设计提供了理论依据。     

Empirical analysis of systematic errors in Chilean GDP forecasts

This paper presents a statistical comparison between the actual and predicted evolution of the Chilean GDP for the period 1986 – 1998 made by several forecasters. We show that the forecasters systematically underestimate the true growth rate of the economy. The magnitude of this bias tends to be correlated with the phase of the business cycle. Copyright © 2001 John Wiley & Sons, Ltd.     

2-均匀多部竞赛图的分量共轭圈问题(Ⅱ)

讨论均匀多部竞赛图,证明一个2-强连通2-均匀的n-部竞赛图（n≥6）包含一对分量共轭圈．     

一类Volterra方程极限环的存在性和稳定性

通过构造Dulac函数, 作Poincaré环域外境界线,应 用张芷芬惟一性定理和分支问题的Friedrich方法, 对Volterra方程进行了研究, 在较一般的条件下讨论了Volterra方程极限环的存在性和稳定性.     

一种改进的确定性准规则LDPC码

提出了一种确定性准规则LDPC码的设计方法,通过双对角矩阵以及迭代生成的线性同余序列构造校验矩阵.推导了为避免四边以及更少边的循环,迭代参数所需要满足的条件.该方法主要优点是编码仅具有线性复杂度,并且校验矩阵可通过迭代和双对角矩阵生成,在译码端不需要存储整个校验矩阵,这对于译码器的硬件实现是有利的.仿真结果表明该方法具有优于伪随机方法的性能.     

Forecasting UK industrial production over the business cycle

This paper examines the information available through leading indicators for modelling and forecasting the UK quarterly index of production. Both linear and non‐linear specifications are examined, with the latter being of the Markov‐switching type as used in many recent business cycle applications. The Markov‐switching models perform relatively poorly in forecasting the 1990s production recession, but a three‐indicator linear specification does well. The leading indicator variables in this latter model include a short‐term interest rate, the stock market dividend yield and the optimism balance from the quarterly CBI survey. Copyright © 2001 John Wiley & Sons, Ltd.