Study on the roles and acting mechanism of the real estate brokerage in China second-hand housing market

As China housing reform deepens, the second-hand housing transactions become more and more popular and real estate brokerages, as an intermediary of the transactions, become an undeniable important part of this market. This article mainly explores the roles and the acting mechanism of real estate brokerages in the second-hand housing market. The results show that the participation of real estate brokers in the second-hand housing market may have positive and negative influences. On one side, brokers ease the housing transaction process and benefits buyers and sellers by shortening the sale time on the market. On the other side, if brokers are the only participants in the housing transaction, acting as buyer and seller like some firms do, housing prices will increase and this negative effect will become even stronger as the participation of many more brokers increases. Therefore, the regulation and management of the industry is vital for the long and healthy development of the housing market in China.

Evaluation of an Agent Based Monitoring and Brokerage System for Neighbourhood Electricity Usage Optimization

The current paper presents the evaluation results of a monitoring system, developed within NOBEL （Neighbourhood Oriented Brokerage Electricity） project. NOBEL is an EU funded project of the 7th Framework Programme that developed a pilot monitoring and energy brokerage system, within a local electricity network, aiming to the optimization of energy usage by reducing consumption and maximizing RES （renewable energy sources） usage on neighbourhood level. A holistic evaluation methodology was followed encompassing all aspects, focusing on the enhancement of energy efficiency due to NOBEL system. In specific, indicators related to energy and monetary impacts were analysed and finally assessed. The system was tested through pilot trials in Alginet, a village in Spain. NOBEL managed to achieve total energy savings of 12%, contributing also to respective emissions reduction and to economic benefits for brokerage platform participants. Analytic results and conclusions are presented in the current manuscript that will assess the project＇s system overall performance.

Survey of E-Commerce Modeling and Optimization Strategies

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.

Unnormalized and normalized forms of gefura measures in directed and undirected networks

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.