To minimize the inventory costs of detecting demand change, an acceptance/rejection method （ threshold） is proposed. The proposed threshold can be identified by the newsvendor based on the excess cost, the shortage ...To minimize the inventory costs of detecting demand change, an acceptance/rejection method （ threshold） is proposed. The proposed threshold can be identified by the newsvendor based on the excess cost, the shortage cost, the transitional probability of the demand change, and the magnitude of the demand change. Compared with the single exponential smoothing method, it is proved that the proposed method can save many more inventory costs when detecting a step change in demand. By analyzing the proposed method, it shows that as the magnitude of step change increases, the supply chain members turn to synchronously judge a step change, and as excess （ shortage） cost increases, a newsvendor tends to respond slowly （early） to an increase in demand and responds early （slowly） to a decrease in demand. Observations from this study suggest that supply chain members should pay careful attention to different profit-margin products and different magnitude demand changes in cooperating and sharing demand information with others.展开更多
The widening gap between the supply and demand levels for livestock and poultry products in the Chinese mainland poses a significant challenge to the secure supply of feed grains. Therefore, the accurate prediction of...The widening gap between the supply and demand levels for livestock and poultry products in the Chinese mainland poses a significant challenge to the secure supply of feed grains. Therefore, the accurate prediction of the demand potential for feed grains represents a key scientific issue for ensuring food security in the Chinese mainland. This study is based on an analysis of several factors, such as the Chinese mainland’s output, trade volume, apparent consumption of livestock and poultry products, and two different scenarios for predicting the future demand for feed grains are assessed. The results indicate that output and consumption of livestock and poultry products, as well as the country’s trade deficit and the pressure of the supply and demand balance with respect to these products, have been increasing in recent years. The analysis predicts that the demand for feed grains in the Chinese mainland will reach 425.5 or 389.6 million tons in 2030 based on the two scenarios. This finding indicates that with the increasing demand for livestock and poultry products in the Chinese mainland, the demand for feed grains will continue to increase, and the shortfall in feed grains and raw materials will expand further, especially dependence on external sources of protein-rich feed grains will remain high.展开更多
It has long been known that human activities such as waste fluid disposal and reservoir impoundment may cause earthquakes. Recently, anthropogenic activities to tackle the increasing energy demand and to address clima...It has long been known that human activities such as waste fluid disposal and reservoir impoundment may cause earthquakes. Recently, anthropogenic activities to tackle the increasing energy demand and to address climate change issues are also reported to induce earthquakes. These activities have a common attribute in that fluids are injected and extracted underground and induce spatiotemporal changes of pore pressure and stress, which may cause slip on faults. Induced earthquakes not only pose significant impacts on seismic hazard assessment and preparation, but also raise the question to the society as how to balance the economic needs of resources development and the public's concerns about potential environmental impacts. Here we review the observations of fluid-injection/extraction induced earthquakes, ground deformation associated with these activities, and their physical mechanisms. Furthermore, we discuss the influences of induced earthquakes on seismic hazard models, regulatory policies on these anthropogenic activities, and current development of academic, industrial and government initiatives and collaborations in order to understand this intriguing phenomenon and address associated challenges.展开更多
基金The National Natural Science Foundation of China(No.71171049,71390335)
文摘To minimize the inventory costs of detecting demand change, an acceptance/rejection method （ threshold） is proposed. The proposed threshold can be identified by the newsvendor based on the excess cost, the shortage cost, the transitional probability of the demand change, and the magnitude of the demand change. Compared with the single exponential smoothing method, it is proved that the proposed method can save many more inventory costs when detecting a step change in demand. By analyzing the proposed method, it shows that as the magnitude of step change increases, the supply chain members turn to synchronously judge a step change, and as excess （ shortage） cost increases, a newsvendor tends to respond slowly （early） to an increase in demand and responds early （slowly） to a decrease in demand. Observations from this study suggest that supply chain members should pay careful attention to different profit-margin products and different magnitude demand changes in cooperating and sharing demand information with others.
基金The Key Deployment Project of Chinese Academy of Sciences (ZDBS-SSW-DQC)。
文摘The widening gap between the supply and demand levels for livestock and poultry products in the Chinese mainland poses a significant challenge to the secure supply of feed grains. Therefore, the accurate prediction of the demand potential for feed grains represents a key scientific issue for ensuring food security in the Chinese mainland. This study is based on an analysis of several factors, such as the Chinese mainland’s output, trade volume, apparent consumption of livestock and poultry products, and two different scenarios for predicting the future demand for feed grains are assessed. The results indicate that output and consumption of livestock and poultry products, as well as the country’s trade deficit and the pressure of the supply and demand balance with respect to these products, have been increasing in recent years. The analysis predicts that the demand for feed grains in the Chinese mainland will reach 425.5 or 389.6 million tons in 2030 based on the two scenarios. This finding indicates that with the increasing demand for livestock and poultry products in the Chinese mainland, the demand for feed grains will continue to increase, and the shortfall in feed grains and raw materials will expand further, especially dependence on external sources of protein-rich feed grains will remain high.
基金supported by the NSFC/RGC Joint Research Scheme sponsored by the Research Grants Council of the Hong Kong Special Administrative Region, China (Grant Nos. N_CUHK418/15, N_CUHK430/16)CUHK-University of Manchester Research Fund (Grant No. 4930227)+4 种基金United States National Science Foundation (Grant No. OCE-1357433)Natural Sciences and Engineering Research Council of Canada (Grant No. STPGP 494141-16)Japan Society for the Promotion of Science (Grant Nos. KAKENHI 2624004, 26280006)National Natural Science Foundation of China (Grant No. 41474033)the Summer School Program of Peking University
文摘It has long been known that human activities such as waste fluid disposal and reservoir impoundment may cause earthquakes. Recently, anthropogenic activities to tackle the increasing energy demand and to address climate change issues are also reported to induce earthquakes. These activities have a common attribute in that fluids are injected and extracted underground and induce spatiotemporal changes of pore pressure and stress, which may cause slip on faults. Induced earthquakes not only pose significant impacts on seismic hazard assessment and preparation, but also raise the question to the society as how to balance the economic needs of resources development and the public's concerns about potential environmental impacts. Here we review the observations of fluid-injection/extraction induced earthquakes, ground deformation associated with these activities, and their physical mechanisms. Furthermore, we discuss the influences of induced earthquakes on seismic hazard models, regulatory policies on these anthropogenic activities, and current development of academic, industrial and government initiatives and collaborations in order to understand this intriguing phenomenon and address associated challenges.
