The rise and transformation of the Brazilian landless movement into a counter-hegemonic political actor: A Gramscian analysis

The Brazilian Landless Movement (MST) is widely acknowledged as one of the most organized, dynamic, and influential social movements in Latin America. The MST has increasingly inserted the struggle for land within larger political contestations for broad social change, leading conservatives and leftists alike to describe it as a “first class actor” in Brazilian politics. What explains the move from corporatist struggles for land to broader counter-hegemonic contestations; put differently, how did the MST come to acquire ‘global ambition’? Much of the literature on the MST analyzes its external actions but without explaining what drives these actions. This paper utilizes a Gramscian political ecology approach to comprehend the MST’s political actions and its rise and transformation into a counter-hegemonic political actor. Specifically, I evaluate the development of the MST’s organizational praxis from corporatist struggles for land in the late 1970s to ‘global ambition’ and changing nature-society relations by the early 2000’s. Such an approach brings to light the role of organization building, political education, alliance building, and subaltern agency in propelling the MST’s political mobilizations. In so doing, this paper contributes to the literature on the MST and collective action. This paper also engages with a ‘politics of scale’ since the conquest of geographic scale is critical to understanding the MST’s national growth and political actions. This paper concludes by arguing that the rise and transformation of the MST into a vibrant counter-hegemonic actor in Brazilian politics was a gradual process that matured as it territorialized into a national movement.     

APPLICATION OF MEM SPECTRAL ESTIMATION TO MU RADAR OBSERVATION

Preliminary results of the wind velocity estimation using the Maximum Entropy Method (MEM) to MUradar observation data sets are presented. The comparison of the results from the periodogram method and theMEM shows that the MEM estimation is reliable, and has higher accuracy, resolution and detectability than theestimation from periodogram method. The high accuracy power spectrum obtained by the MEM is veryuseful to studying the atmospheric turbulence structure. However. the MEM needs the longer computingtime for obtaining the high accuracy spectrum. Particularly, the estimation of MEM will bring serious devia-tion at lower signal-to-noise ratio.     

骨架优化下的地面激光树木点云重建方法

本文针对地基式激光雷达扫描点云的分布特征,提出一种基于骨架优化的三维树木重建方法。首先从原始点云中提取出树木的“类主干点”,利用无向图数据结构存储和组织点云,然后基于“主干点”约束下的最小生成树算法生成单株树木的初始骨架,最后通过“密度调整”和“树枝平滑”优化操作,建立高逼真度的三维树木模型。本文提出的树木几何重建算法对点云数据缺失和点云的密度不敏感,对试验区不同的树种建模具有较高的鲁棒性。另外,本文通过对不同密度的点云和不同抽稀层次下的点云进行效率测试,发现结合类主干点表达和点云抽稀能共同确保本文算法可以重建大场景TLS植被点云数据。     

基于Prim算法的GIS连通性研究

通过分析传统的Prim算法及其数据结构与实现方法,本文提出了一种基于边存储结构和AE的改进Prim算法.改进算法优化并降低了原算法的时间复杂度与空间复杂度,提高了算法的运行效率,并应用于某城市交通网络的最优生成树(MST)的建立,实验分析证明了改进的算法更加适用于GIS海量数据的连通性分析与实现.     

Countering Inequality: Brazil's Movimento Sem‐Terra

Data from a national survey of formerly landless peasants residing in federal land‐reform settlements in Brazil (Pesquisa Nacional de Educação na Reforma Agrária—PNERA) confirm that the Landless Rural Workers Movement (Movimento dos Trabalhadores Rurais Sem‐Terra—MST) has been far more successful than other settlement movements in assuring a better quality of life for its members. This superior performance is attributed to an organizational structure that demands and assures membership involvement, and a commitment to participatory education in an environment that fosters and supports MST's goals and objectives. MST's members have higher self‐perceived social status than members of non‐MST movements, have better residential environments and more material possessions, and experience an education that emphasizes the movement's principles of social justice, radical democracy, and humanist and socialist values.     

The MST radar technique: Potential for middle atmospheric studies

We examine the potential of the MST (mesosphere-stratosphere-troposphere) radar technique for obtaining detailed information on the middle atmosphere. This technique-which uses very sensitive coherent VHF and UHF radars-is capable of detecting signal returns arising from weak fluctuations in the atmospheric refractive index. With certain limitations the MST technique is capable of continually observing winds, waves, turbulence and atmospheric stability over the height range 1–100 km with good-to-excellent time and space resolution. We examine the relatively large body of literature that has been written over the past few years and outline some aspects of a promising future.     

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北京MST雷达探测中间层-低热层观测结果初步分析

北京MST雷达是子午工程建设的国内仅有的两部MST雷达之一,为研究其在中间层-低热层MLT区域的探测能力以及数据可靠性,本文应用北京MST雷达2012、2013两年高模式数据,从数据获取率、与廊坊流星雷达测风对比以及风场时空分布特征三个方面进行初步分析.结果是:(1)数据获取率日变化特征为:白天65~100km均可获取数据,数据获取率的高值区主要集中在70~80km,最大值可达80%;夜间主要集中在80~100km,数据获取率在30%及以下.表明该MST雷达白天可以探测到电离层D层和E层低层,夜间D层消失,只探测到E层低层.季节变化特征为:夏季白天可获取数据的时间和高度区间都比较大,春季次之,冬季最小.夏季白天以及日落后1h内可探测到120km.(2)对北京MST雷达与廊坊流星雷达2012年5月份、80~100km高度区间测量的水平风进行对比分析,二者测风结果在时空分布上有很好的一致性,表明MST雷达探测数据是可靠的.(3)2012年和2013年相应月份平均的纬向风、经向风时空分布特征有较高的一致性,并与HWM07模式结果也基本一致.上述初步分析结果表明,北京MST雷达对中间层-低热层60~120km高度区域已具备较强的探测能力,所得结果将可用于MLT过程揭示与驱动因子研究,并可与该高度上其他探测手段作综合研究.     

Investigating the Dominant Source for the Generation of Gravity Waves during Indian Summer Monsoon Using Ground-based Measurements

Over the tropics,convection,wind shear(i.e.,vertical and horizontal shear of wind and/or geostrophic adjustment comprising spontaneous imbalance in jet streams) and topography are the major sources for the generation of gravity waves.During the summer monsoon season(June-August) over the Indian subcontinent,convection and wind shear coexist.To determine the dominant source of gravity waves during monsoon season,an experiment was conducted using mesosphere-stratosphere-troposphere(MST) radar situated at Gadanki(13.5 N,79.2 E),a tropical observatory in the southern part of the Indian subcontinent.MST radar was operated continuously for 72 h to capture high-frequency gravity waves.During this time,a radiosonde was released every 6 h in addition to the regular launch(once daily to study low-frequency gravity waves) throughout the season.These two data sets were utilized effectively to characterize the jet stream and the associated gravity waves.Data available from collocated instruments along with satellite-based brightness temperature(TBB) data were utilized to characterize the convection in and around Gadanki.Despite the presence of two major sources of gravity wave generation(i.e.,convection and wind shear) during the monsoon season,wind shear(both vertical shear and geostrophic adjustment) contributed the most to the generation of gravity waves on various scales.     

顾及Gestalt认知效应的线性岛屿模式识别

从岛屿分布的邻近性、延展性、紧凑性、直线性等特征出发,提出了线性岛屿结构识别的新方法。首先,以Delaunay三角网为空间分析工具,计算岛屿群空间邻近关系,生成空间邻近图;然后,在空间邻近图的基础上生成MST图;最后,利用Gestalt原则对线性阵列结构的识别效应,在MST上通过3次剪枝导出线性岛屿结构。实验结果表明,该方法能够识别出具有明显线性岛屿结构的目标集,与肉眼视觉识别基本一致。