Using low-density discrete Airborne Laser Scanning data to assess the potential carbon dioxide emission in case of a fire event in a Mediterranean pine forest

The aim of study is to map the carbon dioxide (CO₂) emission of the aboveground tree biomass (AGB) in case of a fire event. The suitability of low point density, discrete, multiple-return, Airborne Laser Scanning (ALS) data and the influence of several characteristics of these data and the study area on the results obtained have been evaluated. A sample of 45 circular plots representative of Pinus halepensis Miller stands were used to fit and validate the model of AGB. The ALS point clouds were processed to obtain the independent variables and a multivariate linear regression analysis between field data and ALS-derived variables allowed estimation of AGB. Then, the influence of several characteristics on the residuals of the model was analyzed. Finally, conversion factors were applied to obtain the CO₂ values. The AGB model presented a R² value of 0.84 with a relative root-mean-square error of 27.35%. This model included ALS variables related to vegetation height variability and to canopy density. Terrain slope, aspect, canopy cover, scan angle and the number of laser returns did not influence AGB estimations at plot level.     

国外综合贫困研究及对我国贫困地理研究的启示

20世纪60年代以来国外新城市贫困研究的内容和方法逐步多元化,综合贫困指标体系和以地域为基础的研究方法促进了贫困地理研究。本文首先辨析贫困和综合贫困的概念,综合贫困研究的指标体系和研究方法;再评述国外综合贫困研究的主要内容;最后在分析我国城市贫困研究不足的基础上,提出在指标体系、研究内容、研究方法和空间层次等几个方面拓展转型时期我国城市贫困地理的研究视角。     

基于灰度匹配的序列影像的目标跟踪研究与实现

利用匹配算法对视频帧进行处理可以实现对特定目标的跟踪.通过在Matlab平台上利用基于灰度的匹配算法实现简单背景下的单目标跟踪,来说明目标跟踪的基本过程,并且对在Matlab平台上实现目标跟踪所遇到的坐标系转换、运算速度以及适用范围等问题进行了分析讨论.     

一种引入傅立叶-梅林-仿射两级变换的影像区域匹配框架

针对影像区域匹配方法几何形变敏感的应用局限性,将特征匹配、相位匹配的基本思想引入区域匹配过程,基于傅立叶-梅林-仿射两级变换建立了归一化互相关灰度相似性计算下的自适应模板匹配框架,并详细阐述了该框架下的全局运动估计、模板"粗"纠正与搜索预测、局部仿射变换下的"精"模板动态生成等关键过程与算法。实验证明了该方法的有效性。     

Automatic Dem Generation for Antarctic Terrain

Automatic digital elevation model (DEM) generation has become an established technique within mapping agencies. This paper assesses the effectiveness of automatic DEM generation using area-based matching for glaciated terrain in Antarctica. DEM accuracy is assessed by comparison with check data acquired using analytical photogrammetry and independent field measurements.An optimum DEM collection strategy is identified. DEM success is linked to ground terrain type and it is found that areas of a DEM which can be collected successfully are relatively insensitive to changes in the collection strategy. A method of isolating unsuccessful areas of a DEM for manual editing is tested for Antarctic terrain. In this example, over 90% success is achieved in identifying erroneous DEM results measured against check data.     

Effects of jpeg 2000 compression on automated dsm extraction: evidence from aerial photographs

This paper evaluates the effects of JPEG 2000 compression on automated digital surface model (DSM) extraction, using the area-based matching technique. Two stereopairs of aerial photographs, which have different photo scale, pixel size, and topographic type, are used as the images for the experiments. In the experiments, the DSM generated from the uncompressed image is set as the reference, and the elevation accuracy is computed for a range of compression ratios (2:1 to 100:1). The results show that the employed indices of image quality based on the JPEG 2000 compression are clearly superior to the commonly used JPEG compression technique—especially for high compression ratios. However, the elevation accuracy varies with the compression ratios. Also, JPEG 2000 compression does not have a significant influence on the percentage of the successful matching rate. In addition, a near linear fall-off is observed in extracted DSM accuracy with increasing compression ratios.     

Mothering urban space,governing migrant women: the construction of intersectional positions in area-based interventions in Berlin

In this paper, we investigate new ways of governing migrant populations in Germany brought forth by social policies on the local level of inner-city neighborhoods. In recent years, numerous initiatives on the local level have constituted the ‘migrant neighborhood’ as a site of governmental attention. One initiative that policymakers consider particularly innovative is the neighborhood mothers program in Berlin, a program that instructs migrant women as agents of neighborhood improvement and encourages them to establish peer-to-peer relations to other migrant women in order to pass on social norms. In the paper, we combine governmentality and intersectionality theory to critically examine the modes of behavior change promoted by the neighborhood mothers program and the political rationalities that are used to justify the governing of (and through) migrant women. We draw particular attention to the spatial dimensions of the neighborhood mothers program, to the ways in which it targets domestic and intimate spaces as sites of inspection and intervention and appoints migrant women as ‘door openers’ for entry of the state into the regulation of families and communities.     

转型期中国城市贫困和剥夺的空间模式

利用普查数据、民政数据和问卷调查资料,从城市宏观空间与个体微观层面,系统检测了转型时期中国城市贫困和城市剥夺的空间模式及形成原因.研究发现:城市贫困和剥夺具有在内城区重合、外围区分离的特点.内城居住区的户籍贫困人口在住房、教育、设施等多方面处于被剥夺状况,外围的企业配套区户籍贫困人口则没有很明显的被剥夺状况,外来人口聚居区的低收入和贫困农民工处于被剥夺状况.究其原因,计划经济时代和转型时期的城市住房、建设和更新等空间政策的共同作用,直接导致了户籍贫困人口和农民工生活状况的差异,进而产生了迥异于西方城市特征的中国城市贫困和剥夺的空间模式.