以EOQ公式为基础, 假设物资价格为时间t的函数,直接考虑总费用为订购次数m的整序变量,提出一类变价格的物资库:存优化模型 A ,利用数值积分的复化梯形公式及其余项对模型A作了近似处理,推出了模型B,并对模型B求解,得模型B的唯一解 ,这...以EOQ公式为基础, 假设物资价格为时间t的函数,直接考虑总费用为订购次数m的整序变量,提出一类变价格的物资库:存优化模型 A ,利用数值积分的复化梯形公式及其余项对模型A作了近似处理,推出了模型B,并对模型B求解,得模型B的唯一解 ,这也是模型A的解,即为最佳订购次数,这对物资库存优化模型做了进一步的完善。展开更多
Tungsten current price was transformed yearly to its constant price since 1900, which is roughly decomposed into four components as trend, cycle, impact and random. The core prices, consisting of the trend and the cyc...Tungsten current price was transformed yearly to its constant price since 1900, which is roughly decomposed into four components as trend, cycle, impact and random. The core prices, consisting of the trend and the cycle, present regularities that a long-run cycle is embedded within two major cycles, and major cycle is composed of low-price period and high-price period, along with the rapid rise into a tower, and along with deep down into next trough; three sharply upward shocks occur by the events in a tower. Fluctuations in prices trend to slow cycles and expand the bands. It can be expected that tungsten price will highly stand over 17 a, and is is a advice that reducing production and restricting export maybe maintain a high price level.展开更多
The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals （copper, aluminum and zinc） pricesincorporating structural changes. The ...The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals （copper, aluminum and zinc） pricesincorporating structural changes. The results show that copper, aluminum and zinc returns have many structure breaks points, and nonferrous metals have the greatvolatilityrisk during financial crisis. From the resultsof GARCH with and without structural changes,it isfoundthat the volatility clustering of single nonferrous metal is overvalued when ignoring the structural mutation, and the return of aluminum isthe most overvalued, indicating that aluminum market is more susceptible to external shock.Furthermore,it is also foundthatdynamic volatility correlation exists in the three prices of nonferrous metals, and the structural changes have no significant effect on the volatility correlation of thethree nonferrous metals.展开更多
Based on a time-varying parameter structural vector autoregression with stochastic volatility(TVP-SVAR-SV)model,the time-varying effects and country differences of economic policy uncertainty(EPU)on gold prices from A...Based on a time-varying parameter structural vector autoregression with stochastic volatility(TVP-SVAR-SV)model,the time-varying effects and country differences of economic policy uncertainty(EPU)on gold prices from August 2006 to December 2017 were examined.The results show that the effects of global economic policy uncertainty(GEPU)shock on gold prices change over time.The changes were positive during 2006-2008 and 2013-2017,while the impacts were negative during 2009-2012,implying that the efficiency of gold as a safe haven is not stable and depends on economic conditions.There are significant country differences regarding the impact of EPU on the price of gold,particularly during the international financial crisis,European debt crisis and Trump election.During the international financial crisis,EPU exerts a positive impact on gold prices in most countries.During the European debt crisis,the impact of EPU on gold prices is mainly negative in the examined countries.While during the Trump election,the impact displays positive and negative alternating in most countries.展开更多
In this study, we build a double auction market model, which contains two types of agent traders, i.e., the noise traders and fundamentalists, to investigate the effect of the trader composition on the stock market. I...In this study, we build a double auction market model, which contains two types of agent traders, i.e., the noise traders and fundamentalists, to investigate the effect of the trader composition on the stock market. It is found that, the non-trivial Hurst exponent and the fat-tailed distribution of transaction prices can be observed at any ratio of the noise traders. Analyses on the price variation properties, including the Hurst exponent and the price variation region, show that these properties are stable when the ratio is moderate. However, the non-price variation properties, including the trading volume and the profitability of the two kinds of agents, do not keep stable untrivially in any interval of the ratio of noise traders.展开更多
文摘以EOQ公式为基础, 假设物资价格为时间t的函数,直接考虑总费用为订购次数m的整序变量,提出一类变价格的物资库:存优化模型 A ,利用数值积分的复化梯形公式及其余项对模型A作了近似处理,推出了模型B,并对模型B求解,得模型B的唯一解 ,这也是模型A的解,即为最佳订购次数,这对物资库存优化模型做了进一步的完善。
基金Project(2013ZK2001)supported by the Major Soft Science Program of Hunan Provice,ChinaProjects(1382ZD024,13BGL105)supported by the National Social Science Foundation of China
文摘Tungsten current price was transformed yearly to its constant price since 1900, which is roughly decomposed into four components as trend, cycle, impact and random. The core prices, consisting of the trend and the cycle, present regularities that a long-run cycle is embedded within two major cycles, and major cycle is composed of low-price period and high-price period, along with the rapid rise into a tower, and along with deep down into next trough; three sharply upward shocks occur by the events in a tower. Fluctuations in prices trend to slow cycles and expand the bands. It can be expected that tungsten price will highly stand over 17 a, and is is a advice that reducing production and restricting export maybe maintain a high price level.
基金Project(71072079)supported by the National Natural Science Foundation of China
文摘The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals （copper, aluminum and zinc） pricesincorporating structural changes. The results show that copper, aluminum and zinc returns have many structure breaks points, and nonferrous metals have the greatvolatilityrisk during financial crisis. From the resultsof GARCH with and without structural changes,it isfoundthat the volatility clustering of single nonferrous metal is overvalued when ignoring the structural mutation, and the return of aluminum isthe most overvalued, indicating that aluminum market is more susceptible to external shock.Furthermore,it is also foundthatdynamic volatility correlation exists in the three prices of nonferrous metals, and the structural changes have no significant effect on the volatility correlation of thethree nonferrous metals.
基金Projects(71633006,71874210,71874207,71573282) supported by the National Natural Science Foundation of China
文摘Based on a time-varying parameter structural vector autoregression with stochastic volatility(TVP-SVAR-SV)model,the time-varying effects and country differences of economic policy uncertainty(EPU)on gold prices from August 2006 to December 2017 were examined.The results show that the effects of global economic policy uncertainty(GEPU)shock on gold prices change over time.The changes were positive during 2006-2008 and 2013-2017,while the impacts were negative during 2009-2012,implying that the efficiency of gold as a safe haven is not stable and depends on economic conditions.There are significant country differences regarding the impact of EPU on the price of gold,particularly during the international financial crisis,European debt crisis and Trump election.During the international financial crisis,EPU exerts a positive impact on gold prices in most countries.During the European debt crisis,the impact of EPU on gold prices is mainly negative in the examined countries.While during the Trump election,the impact displays positive and negative alternating in most countries.
基金Supported by National Natural Science Foundation of China under Grant Nos.60973152 and 60573172Doctoral Program Foundation of Institution of Higher Education of China under Crant No.20070141014Natural Science Foundation of Liaoning Province of China under Grant No.20082165
文摘In this study, we build a double auction market model, which contains two types of agent traders, i.e., the noise traders and fundamentalists, to investigate the effect of the trader composition on the stock market. It is found that, the non-trivial Hurst exponent and the fat-tailed distribution of transaction prices can be observed at any ratio of the noise traders. Analyses on the price variation properties, including the Hurst exponent and the price variation region, show that these properties are stable when the ratio is moderate. However, the non-price variation properties, including the trading volume and the profitability of the two kinds of agents, do not keep stable untrivially in any interval of the ratio of noise traders.
