Qualitative satellite image analysis: Mapping spatial distribution of farming types in Ethiopia

Satellite images have enormous potential for qualitative land use analysis. This paper presents empirical results that demonstrate how normally invisible dimensions produced by land use can be identified by enriching satellite data with qualitative information from field studies.Land use can be defined as the intentional use of a specific piece of land resulting in patterns of ecological responses that are visible in the land cover and landscape. Responses to land use often result in a heterogeneous combination of reflectance in satellite images. Statistical methods used in the classification of satellite imagery are limited in their capacity to handle categories consisting of heterogeneous combinations of spectral values. To overcome this limitation, a contextual post-classification method has been used to map land cover configurations as related to different agricultural practices in the district of Sodo, Ethiopia.The results show that it is possible to map socio-spatial distribution of different agricultural and socioeconomic practices on a regional level by combining field observations and spatial contextual information. The empirical findings show local agricultural activity variations in cash crop production and subsistence agriculture in the Sodo district of Ethiopia.     

A Preliminary Study of the Self-Directed Photography of Middle-Class,Homeless, and Mobility-Impaired Children*

Understanding the ways in which children with different life experiences come to terms with day-to-day contexts and constraints has become an important topic of social science research. This study applies the technique of auto-photography to the study of children-environment transactions. How children apprehend their environments is described through a leitmotif analysis and an interpretation of photographs taken by children from middle-class families, homeless children, and children whose mobility is impaired by cerebral palsy. We speculate upon the social and physical contexts of these children based upon the images that they selected to photograph. Although impressionistic, our findings suggest the importance of auto-photography as a method for uncovering children-environment transactions.     

Assessing the social context of wildfire-affected areas. The case of mainland Portugal

Wildfires cause different impacts, depending on the conditions and resilience level of the exposed communities. Wildfire occurrence in mainland Portugal was assessed with regard to socioeconomic and demographic parameters, to identify the most distinctive conditions of fire-affected areas, without implying the existence of causal relationships. The latest population and agriculture census data were used to retrieve conditions at the civil parish level, regarding demographic patterns, social and labor conditions, physical structures and agricultural activities. To identify differences between parishes, two groups were created with the communities that showed the highest and lowest 20% of wildfire incidence between 2007 and 2014, separately for density of fire events and for burned area. A stepwise approach based on classification trees and random Forest methods was applied to identify the best discriminant variables between the groups. First, irrelevant variables were removed by an interactive process based on misclassification rates. The second step used random Forest analysis to the remaining variables to evaluate their importance in distinguishing the groups. In the final step, cluster analysis was applied to test the correspondence between the clusters created with the selected variables and the initial groups. Results showed that parishes with higher fire density have higher population density, higher proportion of young and educated people, larger families and more overcrowded buildings. On the contrary, parishes with larger burned area are less populated, less attractive to foreigners, have a higher proportion of elderly people, more degraded housing conditions and agricultural activities, visible in the density of sheep and goat and pastures, are still relevant. The cluster analysis demonstrated a better performance of the model for wildfire density, revealing a strong association with socioeconomic dynamics with an agreement above 0.85, much higher than for burned areas which is 0.29. Overall, the spatial distribution of wildfire impacts is framed by societal settings and particular conditions must be further understood to improve the coping capacity of affected communities.     

全球价值链绿色化的概念性认知及其研究框架

随着全球国际分工的深化和对环境问题的广泛关注,全球价值链的研究框架也成为西方学界研究环境问题中跨区域性、全球-地方联系和环境权力博弈的重要工具。论文将绿色化问题引入全球价值链的分析框架中,在梳理相关文献的基础上,凝练全球价值链绿色化的内涵;并对全球价值链绿色化的驱动机制、全球价值链经济主体的升级带动的绿色化、全球价值链不同治理模式中管理绿色化等基本问题域进行讨论,初步构建全球价值链绿色化的研究框架;并辨析了不同空间尺度下全球价值链绿色化研究的主题和特点;进而提出未来研究需重点关注环境权力关系的界定、绿色化治理的模式以及全球尺度的绿色化网络等方面,旨在为全球价值链下环境问题的分析提供一定的理论依据。     

国外工业联系研究的理论发展及其对我国的借鉴意义

本文主要探讨了西方工业地理学关于工业联系研究的理论进展、发展背景和它所涉及的主要问题。在第二部分,着重对我国新时期条件下工业联系研究的可能性和必要性进行了讨论。其中特别是对我国现阶段生产组织形式的某些变化和西方国家作了对比,并就我国工业联系研究的某些可能领域及其意义作了论述。     

长江经济带区域合作的格局与演变

梳理区域合作的政治经济环境演变,试图对长江经济带区域合作的主体、主题、形式和发展水平等进行综合分析。流域管治事务复杂,部门管理与行政区管理交叉,造就了区域合作模式多样与发展水平差异。经济带在长江防洪、大通关和检疫等方面的合作发展迅速,而在水资源环境、港口岸线、基础设施和生态补偿等方面的信息共享和合作平台建设仍发展缓慢。长三角已经建立了覆盖全、层次多、主题丰富的区域合作机制;由于国家长期对成渝经济区的推崇,两地在区域性项目建设上合作密切;中游四省合作发展水平相对最低,缺乏强有力的中心城市引领,地区竞争大于合作激励。     

A context-sensitive correlated random walk: a new simulation model for movement

Computational Movement Analysis focuses on the characterization of the trajectory of individuals across space and time. Various analytic techniques, including but not limited to random walks, Brownian motion models, and step selection functions have been used for modeling movement. These fall under the rubric of signal models which are divided into deterministic and stochastic models. The difficulty of applying these models to the movement of dynamic objects (e.g. animals, humans, vehicles) is that the spatiotemporal signal produced by their trajectories a complex composite that is influenced by the Geography through which they move (i.e. the network or the physiography of the terrain), their behavioral state (i.e. hungry, going to work, shopping, tourism, etc.), and their interactions with other individuals. This signal reflects multiple scales of behavior from the local choices to the global objectives that drive movement. In this research, we propose a stochastic simulation model that incorporates contextual factors (i.e. environmental conditions) that affect local choices along its movement trajectory. We show how actual global positioning systems observations can be used to parameterize movement and validate movement models and argue that incorporating context is essential in modeling movement.     

意义概念的三个模型

弗雷格首先把意义概念引入分析哲学,其真正目的是坚持思想有公认的确定的正确与错误之分,为思想的客观分析提供基础,但其借助的意义即思想的实体化却有违于这个初衷。直接经验论者从直接经验论立场出发,企图在经验世界中找意义,最后走向否定意义本身,分析哲学由此遭到重创。从语言、思想、世界的关系的高度,把弗雷格的意义理论、观念论、用法论的合理精神结合起来,构建了语境—思想意义模型,认为语言的意义既是主观的东西,同时又具有特殊的客观性:由公共客观的语境决定的确定性。语言的意义就是特定语境中的语言所表达的人们的思想。     

基于轮廓的侧扫声呐图像配准

针对侧扫声呐图像存在局部畸变,导致共视目标不一致的问题,本文提出了一种基于轮廓的侧扫声呐图像配准方法。首先提取图像中目标轮廓并计算每个轮廓点的环境上下文描述,以环境上下文的χ²检验统计量作为代价函数;然后通过使得所有匹配点对的代价和最小,获得轮廓点的对应关系;最后使用正则化的薄板样条函数对图像变换关系求解,建立轮廓内部像素的对应关系。试验结果表明,本文方法能够较好地保证共视目标的一致性,具有一定的借鉴价值。     

基于图的语义室内导航模型构建研究

室内空间模型是室内导航的基础和关键所在,针对当前多数室内空间模型在建模过程中只考虑部分导航相关的影响因素,适用范围有限这一问题,结合室内导航特点,综合考虑用户室内移动特征、几何和语义信息表达、路径规划效率3个方面的建模影响因素,提出一种基于图的语义室内导航模型。基于图论的方法构建室内导航概念模型,然后在概念模型的基础上提出具体的几何图模型构建方法和语义信息表达方式,设计图模型中节点和边的数据结构,最后研究将该模型用于不同情景下室内路径规划的具体流程。