Streaming Algorithm for Euler Characteristic Curves of Multidimensional Images

We present an efficient algorithm to compute Euler characteristic curves of gray scale images of arbitrary dimension. In various applications the Euler characteristic curve is used as a descriptor of an image. Our algorithm is the first streaming algorithm for Euler characteristic curves. The usage of streaming removes the necessity to store the entire image in RAM. Experiments show that our implementation handles terabyte scale images on commodity hardware. Due to lock-free parallelism, it scales well with the number of processor cores. Our software---CHUNKYEuler---is available as open source on Bitbucket. Additionally, we put the concept of the Euler characteristic curve in the wider context of computational topology. In particular, we explain the connection with persistence diagrams

Imaginarios en disputa o sobre la territorialización de un conflicto urbano. El caso de “La Canchita de los Bomberos” (Mar del Plata, Argentina)

Apenas transcurridos tres meses de la creación del Programa Crédito Argentino del Bicentenario para la Vivienda Única Familiar, el Municipio de General Pueyrredón anuncia las tierras disponibles para comprometer en su implementación; entre ellas, el predio conocido como Canchita de los Bomberos de la ciudad de Mar del Plata. Frente a ello, se conforma un grupo de vecinos autoconvocados en defensa de su utilización como espacio público-verde, llevando a cabo diversas estrategias cuyo objetivo es evitar la construcción de viviendas en esa zona. Paralelamente, otras personas manifiestan su parecer en relación a la ejecución del programa y desarrollan prácticas que cuestionan la legitimidad de las demandas sostenidas por aquellos vecinos. El propósito del artículo es analizar las formas de apropiación simbólica que se refuerzan y/o modifican en función de la disputa; lo que Melé (2003) llama el proceso de territorialización del conflicto. Se argumenta que, aunque se produce un choque de imaginarios (Hiernaux; 2008a), emerge un imaginario dominante que logra imponerse y legitimar el uso y disfrute del espacio a su favor

Land conflict in peri-urban areas: Exploring the effects of land reform on informal settlement in Mexico

Peri-urban areas are often subject to intensive construction, through both formal and informal processes. As land transitions from rural to urban status, different land tenure and administration systems may come into conflict, leading to disputes, contestation and, in some cases, violence. However, little is known about the precise causes of peri-urban land conflict. In Mexico, peri-urban growth has historically proceeded peacefully, owing to the control exerted by a corporatist system of government, and the political use of land tenure regularisation. However, the effects of land reforms on transactions at the peri-urban fringe, in the context of wider processes of liberalisation, may be increasing vulnerability to conflict over land. This paper explores these issues through a case study of an irregular settlement on the peri-urban fringe of the provincial Mexican city of Xalapa, where contestations over informally developed land have escalated into violent encounters between groups of settlers and the state. The findings show that vulnerability to conflict in peri-urban areas can be attributed to the interaction of macro-level processes with local-level factors, including diverse claims, overlapping legal and governance frameworks and, critically, local power relations

Justice, power and informal settlements: Understanding the juridical view of property rights in Central Asia

The article examines how judges and lawyers struggle to legitimise and normalise private property rights against attempts by poor and migrant groups to politicise housing and social needs in Central Asia. It will discuss the juridical understanding of justice and equality in relation to property rights violations on the outskirts of major cities in Kyrgyzstan and Kazakhstan. It will argue that the juridical system is central in construing property rights and obligations, and in so doing social inequalities are legitimised and naturalised in a neoliberalising post-Soviet space. The article uses the concepts of 'the moral economy' and 'the juridical field' to examine how judges and lawyers justify and normalise their ways of interpreting and ordering the social world

Residential mobility of middle-class and popular sectors: the city of Buenos Aires as an arrival destination

El artículo reflexiona acerca de los patrones de movilidad residencial de individuos y hogares de sectores populares y medios que residen en dos zonas de la Ciudad de Buenos Aires configuradas en torno a patrones disimiles de segregación. La movilidad residencial es un lente privilegiado para evidenciar de qué modo la experiencia de la clase es producida y reproducida en los modos de habitar. Mediante un abordaje cualitativo y biográfico hemos analizado las especificidades que presentan las movilidades residenciales de los diferentes sectores sociales. Se identifican patrones en tres dimensiones de la movilidad residencial: su espacialidad, los arreglos residenciales que los hogares despliegan y las motivaciones que guían sus desplazamientos. Los hallazgos presentados dan cuenta de los efectos que produce la posición en la estructura social sobre la movilidad residencial, así como su interacción con la propia estructuración del espacio.The article reconstructs residential mobility patterns of individuals and households from popular and middle-class sectors residing in two areas of the city of Buenos Aires, configured around dissimilar segregation patterns. Residential mobility is a powerful lens to show how the social class experience is produced and reproduced in modes of dwelling. Through a qualitative and biographical approach, we analyzed the specificities presented by residential mobilities of different social sectors. We identified patterns in the three dimensions of residential mobility: spatiality, the residential arrangements that households employ, and the motivations that guide their movements. The findings show the effects that the position in the social structure has on residential mobility, as well as its interaction with the spatial structure itself.publishedVersionFil: Cosacov, Andrea. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Cosacov, Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biológicas; Argentina.Fil: Di Virgilio, María Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Gino Germani; Argentina.Fil: Najman, Mercedes. Universidad de Buenos Aires. Facultad de Ciencias Sociales; Argentina.Fil: Di Virgilio, María Mercedes. Universidad de Buenos Aires. Facultad de Ciencias Sociales; Argentina.Fil: Najman, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación Gino Germani; Argentina

Strengthening the morphological study of informal settlements

Methods of articulating the morphological structure of slums can have considerable potential in better planning for site-specific design or policy responses for these areas in the contemporary city. Although urban morphology traditionally studies landscapes as stratified residues with distinct divisions between lot and boundary, built and unbuilt, the authors find these definitions insufficient to address the complexity of slum morphology. Through this article, the authors’ identify that morphological analysis of informal settlements needs to be sensitive to the dynamics and the absence (or blurring) of physical boundaries. By analyzing the spatial impact of social, economic, and political factors, situational and site factors, building typologies, and configurations of circulation space, an attempt to articulate the morphological structure of slums is made. Aiming to overcome the current polarization in the literature between the formal and informal city, this article adds to the ongoing research on the study of challenges within contemporary cities, by providing new methodologies for studying the morphology of slum urbanization and shaping planning practice

Territorio, Recursos Naturales y Ambiente: hacia una historia comparada : Estudio a través de Argentina, México, Costa Rica, Haití, Paraguay, Uruguay y Venezuela

Libro -- Universidad de Costa Rica. Centro de Investigaciones Geofísicas, 2014Nuestro objetivo principal ha sido establecer parámetros para una estudio comparativo de los recursos naturales y el ambiente, en función del territorio, en América Latina, a partir del estudio de casos particulares. Más concetamente, nos propusimos determinar: 1. las formas de conocimiento sobre el territorio, sus recursos naturales y su ambiente; y caracterizar los estilos científicos prevalecientes en cada etapa y región; 2. el papel de las instituciones y programas científicos en la formación de una tradición ambientalista local y las modalidades de desarrollo de estas temáticas a lo largo de la historia latinaomericana; 3. los parámetros de comprensión de las temáticas territoriales y ambientales desde las normativas y las políticas públicas de los estados; 4. los objetivos, áreas de investigación,campos de interés y resultados, según surgen de las publicaciones, productos y documentación científicos.Universidad de Costa Rica. Instituto Panamericano de Geografía e Historia (IPGH) Proyecto GEO 01.2013 – HIST. 02.2013.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones Geofísicas (CIGEFI

Alternative formulations to compute the binary shape Euler number

The authors propose two equations based on the pixel geometry and connectivity properties, which can be used to compute, efficiently, the Euler number of a binary digital image with either thick or thin boundaries. Although computing this feature, the authors' technique extracts the underlying topological information provided by the shape pixels of the given image. The correctness of computing the Euler number using the new equations is also established theoretically. The performance of the proposed method is compared against other available alternatives. Experimental results on a large image database demonstrate that the authors technique for computing the Euler number outperforms the earlier approaches significantly in terms of the number of basic arithmetic operations needed per pixel. Both equations are specialised only for 4-connectivity cases. Zapotitlán The Institution of Engineering and Technology 2014