网络地理信息服务中用户访问具有社会群体规律性和重复性。捕捉大规模、高强度的并发用户访问请求的倾斜性与聚集性，可优化服务资源分配，提高服务效率，适应迅速膨胀的网络服务规模。研究群体用户密集访问行为与网络并发服务之间的效用关系，建立高效的并发服务机制，是发展面向"人"的GIS与地理信息科学的关键问题之一。本申请立足于群体用户访问行为的理解，以服务效率与资源分配最优为目标，从资源分配、调度、预取三方面系统研究网络地理信息并发服务方法。基于知识表达系统理论和数据挖掘方法，研究时空偏好的群体用户密集访问模式；基于群体用户访问的时空局部特征，研究分布式多副本策略；基于访问局部控制原理，研究异构服务负载均衡机制；基于概率估算方法，研究自适应访问时空局部变化的浏览路径预取方法。研究成果可用于网络中海量地理信息服务优化，提升服务资源利用率和并发服务效率，扩展服务规模，促进网络地理信息社会化服务及应用。

Group access patterns in network geographic information services follow some social law and have the characteristics of access repeatability. Capture the characteristics of access bias and access density for large-scale and high-intensity concurrent accesses, it can optimize the allocation for service resource and improve the service efficiency, to adapt to the rapid expansion of network geographic information services. To study the effectiveness of the relationship between the access density and the network concurrent services and to build high-efficiency concurrent service methods, it is one of the key issues for the development of oriented-person GIS and geographic information science. Understanding the group access behavior, targeting optimal service efficiency and resource allocation, this proposal studies the concurrent service methods for network geographic information from the resource allocation, resource scheduling and resource prefetching. The main research topics are:1) using the knowledge expression system theory and data mining methods, study space-time preference in the group access-density pattern; 2）using group accesses have characteristic of the spatial-temporal locality, study the distributed replication strategy; 3）using the localized access control principle, study load-balancing method for the heterogeneous services; 4）using probability estimation methods, study prefetching method for navigation path which can self-adapt the spatial-temporal locality changes. The results of the studies can be used to optimize the performance for network services for mass geographic information. These methods can improve the utilization rate of service resource and the efficiency of concurrent service, to enlarge the scale of network geographic information services. This proposal is significant to promote the society services of network geographic information and its applications.