In phase Ⅱ of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the regional climate has been simulated for July 1988 through December 1998 by five regional climate models and one global variable...In phase Ⅱ of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the regional climate has been simulated for July 1988 through December 1998 by five regional climate models and one global variable resolution model. Comparison of the 10-year simulated precipitation with the observations was carried out. The results show that most models have the capacity to reproduce the basic spatial pattern of precipitation for Asia, and the main rainbelt can be reproduced by most models, but there are distinctions in the location and the intensity. Most models overestimate the precipitation over most continental regions. Interannual variability of the precipitation can also be basically simulated, while differences exist between various models and the observations. The biases in the stream field are important reasons behind the simulation errors of the Regional Climate Models （RCMs）. The cumulus scheme and land surface process have large influences on the precipitation simulation. Generally, the Grell cumulus scheme produces more precipitation than the Kuo scheme.展开更多
During phase II of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the Asian climate was estimated from July 1988 to December 1998 using six climate models. In this paper, the abilities of six c...During phase II of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the Asian climate was estimated from July 1988 to December 1998 using six climate models. In this paper, the abilities of six climate models to simulate several important ex- treme climate events in China during the last years of the last century were analyzed. The modeled results for the intensity of the precipitation anomaly over the Yang- tze-Huaihe Valley during the summers of 1991 and 1998 were weaker than the observed values. The positive pre- cipitation anomaly responsible for a catastrophic flood in 1991 was well reproduced in almost all simulation results, but the intensity and range of the precipitation anomaly in 1998 were weaker in the modeled results. The spatial dis- tribution of extreme climate events in 1997, when severe drought affected North China and flood impacted South China, was reproduced by most of the regional models because the anomaly of the large-scale background field was well-simulated, despite poor simulation of high temperature areas in the north during the summer by all models.展开更多
We note that the Single Stage Single Period Multi Commodity Warehouse Location Problem (SSSPMCWLP) has been first attempted by Geoffrion and Graves [1], and that they use the weak formulation (in context of contributi...We note that the Single Stage Single Period Multi Commodity Warehouse Location Problem (SSSPMCWLP) has been first attempted by Geoffrion and Graves [1], and that they use the weak formulation (in context of contribution of this paper). We give for the first time “strong” formulation of SSSPMCWLP. We notice advantages of strong formulation over weak formulation in terms of better bounds for yielding efficient Branch and Bound solutions. However, the computation time of “strong” formulation was discovered to be higher than that of the “weak” formulation, which was a major drawback in solving large size problems. To overcome this, we develop the hybrid strong formulation by adding only a few most promising demand and supply side strong constraints to the weak formulation of SSSPMCWLP. So, the formulations developed were put to test on various large size problems. Hybrid formulation is able to give better bound than the weak and takes much less CPU time than the strong formulation. So, a kind of trade off is achieved allowing efficiently solving large sized SSSPMCWLP in real times using hybrid formulation.展开更多
Based on a 10-year simulation of six Regional Climate Models(RCMs) in phase II of the Regional Climate Model Inter-Comparison Project(RMIP) for Asia,the multivariate statistical method of common principal components(C...Based on a 10-year simulation of six Regional Climate Models(RCMs) in phase II of the Regional Climate Model Inter-Comparison Project(RMIP) for Asia,the multivariate statistical method of common principal components(CPCs) is used to analyze and compare the spatiotemporal characteristics of temperature and precipitation simulated by multi-RCMs over China,including the mean climate states and their seasonal transition,the spatial distribution of interannual variability,and the interannual variation.CPC is an effective statistical tool for analyzing the results of different models.Compared with traditional statistical methods,CPC analyses provide a more complete statistical picture for observation and simulation results.The results of CPC analyses show that the climatological means and the characteristics of seasonal transition over China can be accurately simulated by RCMs.However,large biases exist in the interannual variation in certain years or for individual models.展开更多
Livelocks, like deadlocks, can result in serious results in running process of flexible manufacturing systems(FMSs). Current deadlock control policies(DCPs) based on mixed integer programming(MIP) cannot detect siphon...Livelocks, like deadlocks, can result in serious results in running process of flexible manufacturing systems(FMSs). Current deadlock control policies(DCPs) based on mixed integer programming(MIP) cannot detect siphons that cause and cope with livelocks in Petri nets. This study proposes a revised mixed integer programming(RMIP) method to directly solve the new smart siphons(NSSs) associated with livelocks in a system of sequential systems with shared resources(S^4 R), a typical subclass of generalized Petri net models. Accordingly,the solved NSSs are max'-controlled by adding the corresponding control places(CPs). As a result, an original S^4 R system with livelocks can be converted into the live controlled Petri net system. The related theoretical analysis and an example are given to demonstrate the proposed RMIP and the corresponding control algorithm(CA).展开更多
文摘In phase Ⅱ of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the regional climate has been simulated for July 1988 through December 1998 by five regional climate models and one global variable resolution model. Comparison of the 10-year simulated precipitation with the observations was carried out. The results show that most models have the capacity to reproduce the basic spatial pattern of precipitation for Asia, and the main rainbelt can be reproduced by most models, but there are distinctions in the location and the intensity. Most models overestimate the precipitation over most continental regions. Interannual variability of the precipitation can also be basically simulated, while differences exist between various models and the observations. The biases in the stream field are important reasons behind the simulation errors of the Regional Climate Models （RCMs）. The cumulus scheme and land surface process have large influences on the precipitation simulation. Generally, the Grell cumulus scheme produces more precipitation than the Kuo scheme.
基金supported by the National Key Program for Developing Basic Sciences of China (Grant No.2009CB723904)the General Project of the National Natural Science Foundation of China (Grant No. 40975048)the Innovation Key Program of the Chinese Academy of Sciences (Grant No.KGCX2-YW-356)
文摘During phase II of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the Asian climate was estimated from July 1988 to December 1998 using six climate models. In this paper, the abilities of six climate models to simulate several important ex- treme climate events in China during the last years of the last century were analyzed. The modeled results for the intensity of the precipitation anomaly over the Yang- tze-Huaihe Valley during the summers of 1991 and 1998 were weaker than the observed values. The positive pre- cipitation anomaly responsible for a catastrophic flood in 1991 was well reproduced in almost all simulation results, but the intensity and range of the precipitation anomaly in 1998 were weaker in the modeled results. The spatial dis- tribution of extreme climate events in 1997, when severe drought affected North China and flood impacted South China, was reproduced by most of the regional models because the anomaly of the large-scale background field was well-simulated, despite poor simulation of high temperature areas in the north during the summer by all models.
文摘We note that the Single Stage Single Period Multi Commodity Warehouse Location Problem (SSSPMCWLP) has been first attempted by Geoffrion and Graves [1], and that they use the weak formulation (in context of contribution of this paper). We give for the first time “strong” formulation of SSSPMCWLP. We notice advantages of strong formulation over weak formulation in terms of better bounds for yielding efficient Branch and Bound solutions. However, the computation time of “strong” formulation was discovered to be higher than that of the “weak” formulation, which was a major drawback in solving large size problems. To overcome this, we develop the hybrid strong formulation by adding only a few most promising demand and supply side strong constraints to the weak formulation of SSSPMCWLP. So, the formulations developed were put to test on various large size problems. Hybrid formulation is able to give better bound than the weak and takes much less CPU time than the strong formulation. So, a kind of trade off is achieved allowing efficiently solving large sized SSSPMCWLP in real times using hybrid formulation.
基金supported by the National Natural Science Foundation of China (General Program,Grant No.40975048)the Strategic Priority Research Program-Climate Change:Carbon Budget and Relevant Issues of the Chinese Academy of Sciences (Grant No. XDA05090207)the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No.KZCX2-EW-202)
文摘Based on a 10-year simulation of six Regional Climate Models(RCMs) in phase II of the Regional Climate Model Inter-Comparison Project(RMIP) for Asia,the multivariate statistical method of common principal components(CPCs) is used to analyze and compare the spatiotemporal characteristics of temperature and precipitation simulated by multi-RCMs over China,including the mean climate states and their seasonal transition,the spatial distribution of interannual variability,and the interannual variation.CPC is an effective statistical tool for analyzing the results of different models.Compared with traditional statistical methods,CPC analyses provide a more complete statistical picture for observation and simulation results.The results of CPC analyses show that the climatological means and the characteristics of seasonal transition over China can be accurately simulated by RCMs.However,large biases exist in the interannual variation in certain years or for individual models.
基金the National Natural Science Foundation of China(No.61364004)the Chinese Visiting Scholars to Study Overseas Program supported by China Scholarship Council Foundation(No.[2014]5049,201408625045)+1 种基金the Doctoral Research Funds of Lanzhou University of Technology(No.04-237)the Alumni Foundation of Civil Engineering 77,Lanzhou University of Technology(No.TM-QK-1301)
文摘Livelocks, like deadlocks, can result in serious results in running process of flexible manufacturing systems(FMSs). Current deadlock control policies(DCPs) based on mixed integer programming(MIP) cannot detect siphons that cause and cope with livelocks in Petri nets. This study proposes a revised mixed integer programming(RMIP) method to directly solve the new smart siphons(NSSs) associated with livelocks in a system of sequential systems with shared resources(S^4 R), a typical subclass of generalized Petri net models. Accordingly,the solved NSSs are max'-controlled by adding the corresponding control places(CPs). As a result, an original S^4 R system with livelocks can be converted into the live controlled Petri net system. The related theoretical analysis and an example are given to demonstrate the proposed RMIP and the corresponding control algorithm(CA).
