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排序方式: 共有303条查询结果,搜索用时 15 毫秒
271.
Julia Sluzenski Chiara Meneghetti Timothy McNamara 《Spatial Cognition & Computation》2013,13(3):205-225
Abstract We investigated the influence of environmental axes in a baseball field. In Experiment 1, participants walked either a path in the prototypical orientation (home plate to second base) or one which was rotated 225°. Recall for object locations was best when participants imagined themselves aligned with axes salient from the experienced orientation. In Experiment 2, when learning was through a route text, there was less of an influence of environmental axes. In Experiment 3, when participants walked both paths, memories were good for the atypical orientation, suggesting that task-specific spatial cues can be more influential than a prior conceptual north. 相似文献
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Steven A. Marchette Megan W. Sever Jonathan I. Flombaum Amy L. Shelton 《Spatial Cognition & Computation》2013,13(4):308-328
Perhaps the signature feature of working memory is that it is limited. In the same subjects, we used two different retrieval tasks to independently measure two different limits of spatial memory. Precision was measured by asking participants to localize a missing target item among a field of other targets and distracters. Capacity was measured with a similar task where participants identified, rather than localized, a set of remembered targets from within a larger set of identical items. Across participants, the precision of localization was positively correlated with the number of successfully retrieved items. These data suggest that an individual's representational capacity may ultimately be constrained by their ability to form precise representations of space. 相似文献
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分布式内存数据库的恢复 总被引:1,自引:0,他引:1
对分布式内存数据库的恢复进行了讨论,内容包括:转储、分布式事务提交及日志。在最后提出了一个日志生成算法,该算法针对机群式环境下的应用,对两阶段提交协议(2-Phase-CommitmentProtocol)进行了改进,有着良好的实用前景。 相似文献
277.
翟建平 《中国民航学院学报》1991,9(1):57-65
本文对飞行管理计算机系统 FMCS 的组成部分硬件结构进行了剖析。具体地对2904A 型飞行管理计算机 FMC 和2577B 型控制显示装置 CDU 的组成结构进行了介绍。 相似文献
278.
H.264视频压缩编码显示了强大的编码性能,较H.263和MPEG-4节省近50%的码率,但这是由H.264成倍增加的复杂度得到的。其代码容量和内存占用对硬件的存储器和计算能力提出了极为苛刻的要求,这就阻碍了其商用方案的发展。通过对H.264编码器的C语言级优化,使其对硬件的存储能力和计算能力的要求大大降低。在此基础上,利用Blackfin561的特性,再将代码进行汇编级优化,使代码更易于向DSP硬件平台移植。 相似文献
279.
We have conducted a series of low-velocity impact experiments to understand the dispersion properties of fragments newly created by low-velocity impacts possible in space, especially in geostationary Earth orbit. The test results are utilized to establish a mathematical prediction model to be used in debris generation and propagation codes. Since the expected collision velocity between catalogued objects in geostationary Earth orbit shows a peak at a few hundreds meters per second, these impact experiments were conducted at a velocity range lower than 300m/s. As a typical structure of satellites in geostationary Earth orbit, thin aluminum honeycomb sandwich panels with carbon fiber reinforced plastics face sheets were prepared, while the projectile was a stainless steel ball of 9mm diameter. The data collected through these impact experiments have been re-analyzed based on the method used in the National Aeronautics and Space Administration (NASA) standard breakup model 1998 revision. The results indicate that the NASA standard breakup model derived from hypervelocity impacts could be applied to low-velocity collision possible in geostationary Earth orbit with some modifications. 相似文献
280.
电站铁磁构件早期损伤无损检测方法的研究 总被引:2,自引:0,他引:2
本文通过理论分析和实际检验,探讨了磁记忆检测地电站气轮机时片和高压缸体由应力集中引起的损伤区域进行预诊断的可靠性,并指出,该检测方法在电站实际工程检测中有良好的应用前景。 相似文献