【摘要】 为了解决传统FTP Search Engine的检索时效性问题,提出了一种有针对性的数据采集更新模型。在该模型中,更新频率被设计用于解决在怎样尽可能降低服务器负载压力的前提下保证较高的平均有效下载比率的问题,而队列排序用于解决在一次数据采集更新中怎样确定FTP站点队列采集对象顺序的策略优化。更多还原

【Abstract】 Because the traditional FTP search engines usually adopt centralized spiders to collect data,the temporal effectiveness insuf-ficient is their major demerit.For solving this problem,an efficient data acquisition model is presented.The key technologies involve data update frequency and queue order.The data update frequency is designed to provide a balance between a good ratio of available FTP file download links and a high data acquisition frequency.The queue order is designed to optimize the order strategy of FTP sites in a data acquisition task.更多还原