Electronic commerce is impacting almost all commercial activities. The resulting emerging commercial activities bring with them many new modeling and optimization problems. This survey reviews pioneering works in this...Electronic commerce is impacting almost all commercial activities. The resulting emerging commercial activities bring with them many new modeling and optimization problems. This survey reviews pioneering works in this new area, covering topics in advertising strategy, web page design, automatic pricing, auction methods, brokerage strategy, and customer behavior analysis. Mathematical models for problems in these areas and their solution algorithms are discussed. In addition to presenting and commenting on these works, we also discuss possible extensions and related problems. The objective of this survey is to encourage more researchers to pay attention to this emerging area.展开更多
In some networks nodes belong to predefined groups （e.g., authors belong to institutions）. Common network cen- trality measures do not take this structure into account. Gefura measures are designed as indicators of ...In some networks nodes belong to predefined groups （e.g., authors belong to institutions）. Common network cen- trality measures do not take this structure into account. Gefura measures are designed as indicators of a node＇s brokerage role between such groups. They are defined as variants of betweeuness centrality and consider to what extent a node belongs to shortest paths between nodes from different groups. In this article we make the following new contributions to their study： （1） We systematically study unnormalized gefura measures and show that, next to the ＇structural＇ normalization that has hitherto been applied, a ＇basic＇ normalization procedure is possible. While the former normalizes at the level of groups, the latter normalizes at the level of nodes. （2） Treating undirected networks as equivalent to symmetric directed networks, we expand the definition of gefura measures to the directed case. （3） It is shown how Brandes＇ algorithm for betweenness centrality can be adjusted to cover these cases.展开更多
基金Support by the National Natural Science Foundation of China (No. 70431003) and the National Textile Center of the United States of America ( No. I01-s01 )
文摘Electronic commerce is impacting almost all commercial activities. The resulting emerging commercial activities bring with them many new modeling and optimization problems. This survey reviews pioneering works in this new area, covering topics in advertising strategy, web page design, automatic pricing, auction methods, brokerage strategy, and customer behavior analysis. Mathematical models for problems in these areas and their solution algorithms are discussed. In addition to presenting and commenting on these works, we also discuss possible extensions and related problems. The objective of this survey is to encourage more researchers to pay attention to this emerging area.
基金Project supported by the National Natural Science Foundation of China （No. 71173154）
文摘In some networks nodes belong to predefined groups （e.g., authors belong to institutions）. Common network cen- trality measures do not take this structure into account. Gefura measures are designed as indicators of a node＇s brokerage role between such groups. They are defined as variants of betweeuness centrality and consider to what extent a node belongs to shortest paths between nodes from different groups. In this article we make the following new contributions to their study： （1） We systematically study unnormalized gefura measures and show that, next to the ＇structural＇ normalization that has hitherto been applied, a ＇basic＇ normalization procedure is possible. While the former normalizes at the level of groups, the latter normalizes at the level of nodes. （2） Treating undirected networks as equivalent to symmetric directed networks, we expand the definition of gefura measures to the directed case. （3） It is shown how Brandes＇ algorithm for betweenness centrality can be adjusted to cover these cases.
