非线性延迟系统Runge-Kutta方法的稳定性探讨

针对时间依赖型的非线性多变延迟系统,采用变步长的Runge-Kutta方法求解,证明了匹配一定插值方法的代数稳定的Runge-Kutta方法是VR稳定的。     

人民币汇率制度改革:影响与稳定性

近年来,人民币汇率问题一直是各方面争论的焦点。现在,人民币汇率升值2%,并且不再盯住单一美元,而是参考“一篮子货币”定值。由于人民币汇率调整幅度比较小,所以,短期内会对我国经济产生一定的影响,从长期来看,影响比较小。人民币汇率水平,短期内是会保持比较稳定,但长期来看又存在着值得注意的问题。     

EXISTENCE OF A NONNEGATIVE EQUILIBRIUM PRICE VECTOR IN THE MEAN-VARIANCE CAPITAL MARKET

We derive a necessary and sufficient condition for the existence of a nonnegative equilibrium price vector under which the total demand and supply of each asset balances in the standard mean-variance capital market. Also, we give an explicit formula for such a price vector. This formula shows that the price of assets is an increasing function of , the weighted average of the requested rate of return of individual investors, which tends to infinity as approaches the expected rate of return on the market portfolio. Further, we construct a macroeconomic index which gives information about the soundness of the capital market.     

一种改进型声表面波滤波器在接收机中的应用

针对应用于接收机中中心频率为898.144MHz的声表面波滤波器的缺点,提出了一种改进型的滤波器.改进型的声表面波滤波器采用镜像阻抗连接低插损结构,大大改善了幅频特性,提高了选择性和温度稳定性.将其应用到接收机中,经试验验证效果良好.     

功能金融理论与我国金融体系的稳定性和效率性

功能金融理论认为,金融体系具有便利清算和支付、聚集和分配资源以及分散风险的功能.一个稳定和富有效率的金融体系通过有效发挥这三大核心功能,能够极大地促进一国国民经济的增长.根据该理论,本文通过研究我国金融体系上述三大功能的发挥程度来判断其稳定性和效率性.大量实证资料表明,我国金融体系虽然能够最大限度地动员社会储蓄,便利各种交易的清算和支付,但是其储蓄-投资转化率低下,资源配置功能弱化,风险分散和转移能力不高.因此,应在提高投资转化率、创新金融工具和技术、建立高效融资平台、改善公司治理机制和信息披露机制等方面完善我国的金融体系.     

从美国房价走势透视中国房地产市场走向

内容文章从量化分析的角度出发,研究了全美50个州和哥伦比亚特区房价指数序列的记忆性特征,发现各州房价指数序列均具有一定程度的长记忆性.同时,我们对50个州房价指数记忆参数的估计值进行了聚类分析,由此发现各州房价指数的记忆性呈现出一定的地区聚集性特征,而且还与地区的人口密度存在一定关系,从而为宏观政策制定者在决定房价调控措施的时候提供了有益的新思维,可使楼市更加健康稳定地发展.此外,文章的研究结果对于解决我国房地产市场目前存在的巨大泡沫问题提供了一个全新的视角     

直流电机系统的建模技术研究

本文针对传统直流电机的模型建立问题，基于曲线拟合技术，提出了简洁有效的参数辨识方法。由于实际的直流电机模型正反向参数差别很大，因此本建模方法中对直流电机的正向模型和反向模型分别对待。实验结果验证了所建立的直流电机模型的优越性能。     

Time-varying linkages between tourism receipts and economic growth in South Africa

The causal link between tourism receipts and GDP has recently become a major focus in the tourism economics literature. Results obtained in recent studies about the causal link appear to be sensitive with respect to the countries analysed, sample period and methodology employed. Considering the sensitivity of the causal link, we use rolling window and time-varying coefficient estimation methods to analyse the parameter stability and Granger causality based on a vector error correction model (VECM). When applied to South Africa for the period 1960–2011, the findings are as follows: results from the full-sample VECM indicate that there is no Granger causality between tourism receipts and GDP, while the findings from the time-varying coefficients model based on the state-space representation show that tourism receipts have positive-predictive content for GDP for the entire period, with the exception of the period between 1985 and 1990. Full-sample time-varying causality tests show bidirectional strong causality between tourism receipts and GDP.     

Sovereign bond markets and financial stability in an emerging economy: an application of directed acyclic graphs and SVAR models

During the last two decades, domestic government bond markets have developed significantly in emerging economies. Although the financial sector has benefited accordingly, volatility in this market also has posed potential risks in terms of financial stability. This paper uses directed acyclic graphs and structural vector-autoregressive models to evaluate the impact of different shocks on both the public debt market and financial stability. Results suggest that inflation, the policy interest rate and indicators of risk perception are the variables that most affect the slope of the yield curve. In turn, when the slope increases, there is a positive contemporary effect on bank risk indicators.     

Exchange rate versus inflation targeting: a theory of output fluctuations in traded and non-traded sectors

This paper develops a basic model for output fluctuations in traded and non-traded sectors under two alternative monetary policy regimes; exchange rate targeting (or monetary union) and inflation targeting. The conventional wisdom from one-sector models says that inflation targeting gives better output stabilization than exchange rate targeting when demand shocks occur, but the opposite when supply shocks occur. In a model with a traded and a non-traded sector, we show that the conventional wisdom holds for the non-traded sector. However, for the traded sector, we show that inflation targeting destabilizes output compared with exchange rate targeting when both supply and demand shocks occur. The only shocks where inflation targeting provides the better output stability for the traded sector are shocks to world market prices. The two-sector structure introduces new mechanisms that may turn around earlier results for aggregate production. For instance, a demand shock may induce higher aggregate output fluctuations with inflation targeting than with exchange rate targeting. Furthermore, a positive demand shock may prove to be contractionary under inflation targeting.