Accurate sensing of scene geo-context via mobile visual localization

Image geo-tagging has drawn a great deal of attention in recent years. The geographic information associated with images can be used to promote potential applications such as location recognition or virtual navigation. In this paper, we propose a novel approach for accurate mobile image geo-tagging in urban areas. The approach is able to provide a comprehensive set of geo-context information based on the current image, including the real location of the camera and the viewing angle, as well as the location of the captured scene. Moreover, the parsed building facades and their geometric structures can also be estimated. First, for the image to be geo-tagged, we perform partial duplicate image retrieval to filter crowd-sourced images capturing the same scene. We then employ the structure-from-motion technique to reconstruct a sparse 3D point cloud of the scene. Meanwhile, the geometric structure of the query image is analyzed to extract building facades. Finally, by combining the reconstructed 3D scene model and the extracted structure information, we can register the camera location and viewing direction to a real-world map. The captured building location and facade orientation are also aligned. The effectiveness of the proposed system is demonstrated by experiment results.     

EV-DO监测系统中R-P接口业务信令追踪的研究与实现

在EV-DO网络中,信令监测系统对于用户数据业务运营的分析尤为重要。针对EV-DO网络中的重要数据接口R-P接口间A11及PPP信令CDR(Call Data Record)的合成,结合主叫和寻呼过程的业务特征,提出一系列优化及改进方案。经过EV-DO现网数据的测试以及产生的相应实验结果表明,优化信令与业务数据消息间的关联机制,缩短了数据网络寻呼与用户主叫业务信令的追踪统计时间最高可达30 s,指标的细化提升了故障定位准确性。这项改进方案对于优化网络运维的分析平台有着重要意义。     

基于Landsat 8影像和能量平衡的西安市热场格局研究!

基于2014年8月15日的Landsat 8影像,通过劈窗算法反演西安中心城区地表温度,定量测算热岛中心范围。估算多种地表能量分量,分析热环境格局与地表能量分量的关系。结果表明:(1)西安中心城区城市热岛集中分布在人口、居住、商业密集区、经济技术开发区以及植被覆盖较差的区域;(2)感热、波文比与地表温度呈正相关,人为热与温度呈不显著正相关,净辐射、潜热与地表温度呈显著负相关;(3)城市热岛的地表能量结构中感热与潜热差异是构成城市热岛差异的主要原因。     

21世纪初中国农作物与自然植被物候时空差异

利用离散小波方法对2001~2012年MODIS EVI时序数据进行平滑,基于动态阈值法提取我国植被物候信息,探讨农作物和自然植被物候的时空变化特征。结果表明:(1)我国第一季农作物开始、峰值和结束日期主要以华北平原为中心随海拔的上升而推迟,而自然植被物候更早20d左右,且随海拔的上升先推迟后提前;(2)物候在时序上有显著变化的第一季区域,43.98%开始日期、52.83%峰值日期呈现提前趋势,多在开始晚、结束早的西南区及东北与内蒙古交界处,其余区域开始、峰值日期及81.80%结束日期呈推迟趋势,发生在开始早、结束晚的黄土高原及双季农作区;农作物物候推迟幅度小于自然植被。     

(<Emphasis Type="Italic">m</Emphasis>,<Emphasis Type="Italic">N</Emphasis>)-delay-partitioning approach to stability analysis for T-S fuzzy systems with interval time-varying delay

This paper is concerned with improved stability criteria for uncertain T-S fuzzy systems with interval time-varying delay by means of a new (m,N)-delay-partitioning approach. Based on an appropriate augmented LKF established in the framework of state vector augmentation, some tighter bounding inequalities (Seuret-Wirtinger’s integral inequality, Peng-Park’s integral inequality and the reciprocally convex approach) have been employed to deal with (time-varying) delay-dependent integral items of the derivative of LKF, therefore, less conservative delaydependent stability criteria can be obtained on account of none of any useful time-varying items are arbitrarily ignored. It’s worth mentioning that, when the delay-partitioning number m is fixed, less conservatism can be achieved by increase of another delay-partitioning number N, but without increasing any computing burden. Finally, one numerical example is provided to show that the proposed conditions are less conservative than existing ones.