排序方式: 共有53条查询结果,搜索用时 0 毫秒
51.
施霖 《云南大学学报(自然科学版)》2007,(Z2)
详细分析了1个面向中小连锁销售企业的移动电子商务应用实例,得出如下结论:①移动电子商务应用可以有效降低系统的建设和维护成本;②在企业级的移动电子商务应用应该更多考虑无线连接的延迟和不稳定等特性,尽量在移动终端运行本地应用程序并缓存部分数据. 相似文献
52.
文章以维吾尔文为对象,提出了一种汉维对齐的维文语料库获取方法,通过对照汉维特点,首先对维文进行词干切分,并在此基础上借助词干表和词频表进行词性标注,然后对汉维进行对齐,从而实现汉维双语语料库的获取,对维文及其他少数民族语言的分析及研究提供一种可行的方法. 相似文献
53.
A novel method of systematic error compensation for a position and orientation system 总被引:3,自引:0,他引:3
Xiuxiao Yuan 《自然科学进展(英文版)》2008,18(8):953-964
A novel method is introduced for self-calibration and elimination of systematic errors for a position and orientation system (POS). The method uses a combined bundle block adjustment with POS data (named the POS-supported bundle block adjustment) without a calibration field. On the basis of delivering strict observation equations for POS data, the specific scheme of compensating the translation and drift systematic errors in a POS is given, and a prototype system WuCAPS is developed. The effects of eliminating POS systematic errors using the POS-supported bundle block adjustment for different ground control conditions are tested using two sets of actual aerial photos. The first set was taken over a fiat region in the suburbs of the city of Yingkou in China and tested at a scale of 1:2500. The second set was taken over a high mountainous region in the desert region of Xinjiang in China and tested at a scale of 1:32,000. The empirical results verified that the POS systematic errors can be completely eliminated and the photo elements of exterior orientation obtained by the POS-supported bundle block adjustment can satisfy the requirements of aerial photogrammetric topographic mapping when four full ground control points (GCPs) are emplaced in the comers of the adjustment block for large-scale images of flat regions, but only one full GCP emplaced in the center of the adjustment block is needed for medium-small scale images of mountainous regions. This not only demonstrates the validity of the established mathematical model and the feasibility of the method proposed in this paper, but also avoids the use of a special calibration field. Therefore, it can simplify the existing POS operation rules and dramatically save on practical application costs, laying the theoretical foundation for widesoread use of POS. 相似文献