In this article, based on the theory of two-phase flow and laboratory data, a three-dimensionally model is developed to simulate the floating rates of frazil ice particles in water under covered condition. The Lagrang...In this article, based on the theory of two-phase flow and laboratory data, a three-dimensionally model is developed to simulate the floating rates of frazil ice particles in water under covered condition. The Lagrangian trajectory method is used in the three dimensional simulation for floating rates of fxazil ice particles along a 180° bend channel. The velocity profiles in longitudinal and transverse directions, the turbulence intensity, and the residual pressure are simulated. Under the condition of gravitational similarity, the simulated floating rates of frazil ice particles in the model bend channel and the prototype bend channels are compared. Results indicate that the profiles for floating rates of ice particles for flows in the model channel are similar to those in the prototype bend channels. The simulated floating rates of ice particles are clearly higher along the convex bank than along the concave bank at each cross section. For the prototype bend channel in a large model scale, the variation of floating rate across each cross section is relatively small.展开更多
Since the foreign exchange reform on July 21^st 2005, the flexibility of RMB exchange rate has becoming big, so has the foreign exchange risk. How to effectively manage foreign exchange risk has become an emergent tas...Since the foreign exchange reform on July 21^st 2005, the flexibility of RMB exchange rate has becoming big, so has the foreign exchange risk. How to effectively manage foreign exchange risk has become an emergent task to enterprises. This paper introduces the method of foreign exchange forecast which is the base of foreign exchange risk management, and then deeply discusses different measures of managing the risk.展开更多
The purpose of this paper is to investigate China′s state foreign exchange reserves growth using monthly data in the period January 1994 to December 1998. An economic model is constructed, with a view from its format...The purpose of this paper is to investigate China′s state foreign exchange reserves growth using monthly data in the period January 1994 to December 1998. An economic model is constructed, with a view from its formation mechanism. Time series techniques are used to examine the long run relationship between foreign exchange reserves and the variables included in the model. Our empirical investigation revealed existence of a systematic long run relationship among foreign exchange reserves, exports, imports, and foreign direct investment. In the short run, the Asian financial crises have not significant effect on China′s foreign exchange reserves. Moreover, the recursive tests results indicated that the error correction model was structurally stable over the sample period, implying that the reserve holdings play a significant role in the balance payments adjustment process and separating China economy from the Asian financial crises.展开更多
The stress state and floating sinking reqularity of various particles in fly ash in water were analyzed. The formula for calculating the floating sinking rate was given. And the formula for calculating the magnetic fo...The stress state and floating sinking reqularity of various particles in fly ash in water were analyzed. The formula for calculating the floating sinking rate was given. And the formula for calculating the magnetic force needed to separate magnetic beads from magnetic separator was also obtained.展开更多
The management of resources has been claimed to be as important as scheduling methods.Inefficiency in managing resources may bring about severe delays and cost overruns caused by resource shortages in some cases and/o...The management of resources has been claimed to be as important as scheduling methods.Inefficiency in managing resources may bring about severe delays and cost overruns caused by resource shortages in some cases and/or idle resources in others.Therefore,resources should be utilized efficiently to prevent project failures.Resource leveling is one of the approaches that are used for the management of resources.It aims to minimize fluctuations,peaks,and valleys in resource utilization without changing the completion time of a project and the number of resources required.Although the main principle behind traditional resource leveling is achieving an even flow of resources while the original project duration remains unchanged,the literature supports the need to develop an efficient model that discriminates among the activities that are selected for participation in resource leveling.For this purpose,this study has developed a model that considers the float consumption rates of activities in resource leveling.The float consumption rate is the percentage that is set to determine the maximum amount of float which will be consumed to shift the start time of the activity.The proposed model allows a scheduler to assign float consumption rates to each activity that can be used during the resource leveling procedure.When the required information is inputted,the proposed model automatically changes the required daily resources as it shifts the noncritical activities along their available total float times.The proposed model is expected to minimize the likelihood of severe delays and cost overruns.The model is demonstrated by constructing a network and its resource utilization histograms.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.50979021)supported by the Hefei University of Technology (Grant No.GDBJ2008-020-Seed Grant for Ph D)
文摘In this article, based on the theory of two-phase flow and laboratory data, a three-dimensionally model is developed to simulate the floating rates of frazil ice particles in water under covered condition. The Lagrangian trajectory method is used in the three dimensional simulation for floating rates of fxazil ice particles along a 180° bend channel. The velocity profiles in longitudinal and transverse directions, the turbulence intensity, and the residual pressure are simulated. Under the condition of gravitational similarity, the simulated floating rates of frazil ice particles in the model bend channel and the prototype bend channels are compared. Results indicate that the profiles for floating rates of ice particles for flows in the model channel are similar to those in the prototype bend channels. The simulated floating rates of ice particles are clearly higher along the convex bank than along the concave bank at each cross section. For the prototype bend channel in a large model scale, the variation of floating rate across each cross section is relatively small.
文摘Since the foreign exchange reform on July 21^st 2005, the flexibility of RMB exchange rate has becoming big, so has the foreign exchange risk. How to effectively manage foreign exchange risk has become an emergent task to enterprises. This paper introduces the method of foreign exchange forecast which is the base of foreign exchange risk management, and then deeply discusses different measures of managing the risk.
文摘The purpose of this paper is to investigate China′s state foreign exchange reserves growth using monthly data in the period January 1994 to December 1998. An economic model is constructed, with a view from its formation mechanism. Time series techniques are used to examine the long run relationship between foreign exchange reserves and the variables included in the model. Our empirical investigation revealed existence of a systematic long run relationship among foreign exchange reserves, exports, imports, and foreign direct investment. In the short run, the Asian financial crises have not significant effect on China′s foreign exchange reserves. Moreover, the recursive tests results indicated that the error correction model was structurally stable over the sample period, implying that the reserve holdings play a significant role in the balance payments adjustment process and separating China economy from the Asian financial crises.
文摘The stress state and floating sinking reqularity of various particles in fly ash in water were analyzed. The formula for calculating the floating sinking rate was given. And the formula for calculating the magnetic force needed to separate magnetic beads from magnetic separator was also obtained.
文摘The management of resources has been claimed to be as important as scheduling methods.Inefficiency in managing resources may bring about severe delays and cost overruns caused by resource shortages in some cases and/or idle resources in others.Therefore,resources should be utilized efficiently to prevent project failures.Resource leveling is one of the approaches that are used for the management of resources.It aims to minimize fluctuations,peaks,and valleys in resource utilization without changing the completion time of a project and the number of resources required.Although the main principle behind traditional resource leveling is achieving an even flow of resources while the original project duration remains unchanged,the literature supports the need to develop an efficient model that discriminates among the activities that are selected for participation in resource leveling.For this purpose,this study has developed a model that considers the float consumption rates of activities in resource leveling.The float consumption rate is the percentage that is set to determine the maximum amount of float which will be consumed to shift the start time of the activity.The proposed model allows a scheduler to assign float consumption rates to each activity that can be used during the resource leveling procedure.When the required information is inputted,the proposed model automatically changes the required daily resources as it shifts the noncritical activities along their available total float times.The proposed model is expected to minimize the likelihood of severe delays and cost overruns.The model is demonstrated by constructing a network and its resource utilization histograms.