Deep unsupervised clustering with Gaussian mixture variational autoencoders

We study a variant of the variational autoencoder model with a Gaussian mixture as a prior distribution, with the goal of performing unsupervised clustering through deep generative models. We observe that the standard variational approach in these models is unsuited for unsupervised clustering, and mitigate this problem by leveraging a principled information-theoretic regularisation term known as consistency violation. Adding this term to the standard variational optimisation objective yields networks with both meaningful internal representations and well-defined clusters. We demonstrate the performance of this scheme on synthetic data, MNIST and SVHN, showing that the obtained clusters are distinct, interpretable and result in achieving higher performance on unsupervised clustering classification than previous approaches

Open-ended Learning in Symmetric Zero-sum Games

Zero-sum games such as chess and poker are, abstractly, functions that evaluate pairs of agents, for example labeling them `winner' and `loser'. If the game is approximately transitive, then self-play generates sequences of agents of increasing strength. However, nontransitive games, such as rock-paper-scissors, can exhibit strategic cycles, and there is no longer a clear objective -- we want agents to increase in strength, but against whom is unclear. In this paper, we introduce a geometric framework for formulating agent objectives in zero-sum games, in order to construct adaptive sequences of objectives that yield open-ended learning. The framework allows us to reason about population performance in nontransitive games, and enables the development of a new algorithm (rectified Nash response, PSRO_rN) that uses game-theoretic niching to construct diverse populations of effective agents, producing a stronger set of agents than existing algorithms. We apply PSRO_rN to two highly nontransitive resource allocation games and find that PSRO_rN consistently outperforms the existing alternatives.Comment: ICML 2019, final versio

Avances en la agenda urbana : Santa Cruz de la Sierra

Este libro tiene como objetivo principal, presentar algunos trabajos del SINPA que contribuyeron y representan “Avances en la Gestión Urbana”. Estos artículos son fruto de la experiencia del proyecto SINPA como aporte a los cambios y procesos de fortalecimiento de la gestión urbana en el Municipio de Santa Cruz de la Sierra. La experiencia y lecciones aprendidas en estos últimos tres años, son extremadamente actuales en el año en que la comunidad internacional se reunió para evaluar la experiencia urbana de HABITAT+5, cinco años después de la II Conferencia de las Naciones Unidas para los Asentamientos Humanos (Hábitat II, Estambul 1996) (UNCHS, 1997). Uno de los puntos clave de las recomendaciones de esta Conferencia fue la necesidad de que los gobiernos locales establezcan asociaciones con organizaciones de la sociedad civil, en los procesos de planificación y gestión urbana. Otra línea directriz de Hábitat II fue la profundización de políticas sostenibles de desarrollo urbano, tomando en cuenta los principios ya consagrados en el capítulo 7 de la Agenda 21 (UNEP, 1992)

Fortalecimiento institucional al municipio de Santa Cruz de la Sierra, Bolivia

El programa de Apoyo para la Implementación de los Planes Nacionales de Acción SINPA (Support for Implementation of National Plans of Action) surge para dar cumplimiento a las políticas y directrices proclamadas durante la Conferencia de las Naciones Unidas para los Asentamientos Humanos - HABITAT II (Estambul 1996) (UNCHS 1997) en tres ciudades de diferentes países. En Bolivia, SINPA materializa el fortalecimiento del Gobierno Municipal de Santa Cruz de la Sierra, ciudad tropical prometedora y de grandes contrastes (motor del desarrollo económico, concentra los mayores índices de pobreza absoluta del país), se rige por un convenio suscrito entre el gobierno municipal el Instituto de Estudios de Vivienda y Desarrollo Urbano IHS (Holanda) y dos universidades locales. El país de fuerte tradición centralista y con bajo nivel de relacionamiento y articulación entre los estamentos político y civil, introduce a partir de 1994 drásticas reformas al Estado una de las cuales es la descentralización que se da como municipalización. Con este surgimiento se presentan e identifican una serie de debilidades en los gobiernos locales para enfrentar las nuevas responsabilidades y competencias. SINPA es un intento de subsanar esta realidad desarrollando capacidades de gestión desde el interior del gobierno municipal, enfatizando la planificación desde cuatro pilares: gestión ambiental, fortalecimiento institucional, participación ciudadana y desarrollo económico local

Anemia among indigenous women in Brazil:findings from the First National Survey of Indigenous People's Health and Nutrition

BACKGROUND: Anemia is recognized as a major public health problem that disproportionately affects vulnerable populations. Indigenous women of reproductive age in Brazil are thought to be at high risk, but lack of nationwide data limits knowledge about the burden of disease and its main determinants. This study aimed to assess the prevalence of anemia and associated factors in this population using data from The First National Survey of Indigenous People’s Health and Nutrition in Brazil. METHODS: Data were collected from Indigenous women between 15 and 49 years old based on a nationwide sample of villages. The outcomes of interest were hemoglobin levels (g/dL) and anemia (< 12 g/dL for nonpregnant and < 11 g/dL for pregnant women). Multilevel models were used to explore associations with contextual (village) and individual (household/woman) level variables. RESULTS: Based on data for 6692 Indigenous women, the nationwide mean hemoglobin level was 12.39 g/dL (95 % CI: 12.29–12.50). Anemia prevalence was high (33.0 %; 95 % CI: 30.40–35.61 %) and showed pronounced regional disparities. No village-level characteristics were associated with anemia or hemoglobin levels in the multilevel model. Even after controlling for upper level variables, socioeconomic status, parity, body mass index, and having been treated for malaria were associated with anemia and hemoglobin levels. CONCLUSION: The prevalence of anemia in Brazilian Indigenous women was 12 % greater than the national estimates for women of reproductive age. Anemia prevalence and mean hemoglobin levels among Indigenous women appear to be partly explained by some previously recognized risk factors, such as socioeconomic status, body mass index, and malaria; however, part of the variability in these outcomes remains unexplained. Knowledge of health status and its potential determinants is essential to guide public policies aimed at controlling anemia burden in Indigenous communities

Visual Compositional Learning for Human-Object Interaction Detection

Human-Object interaction (HOI) detection aims to localize and infer relationships between human and objects in an image. It is challenging because an enormous number of possible combinations of objects and verbs types forms a long-tail distribution. We devise a deep Visual Compositional Learning (VCL) framework, which is a simple yet efficient framework to effectively address this problem. VCL first decomposes an HOI representation into object and verb specific features, and then composes new interaction samples in the feature space via stitching the decomposed features. The integration of decomposition and composition enables VCL to share object and verb features among different HOI samples and images, and to generate new interaction samples and new types of HOI, and thus largely alleviates the long-tail distribution problem and benefits low-shot or zero-shot HOI detection. Extensive experiments demonstrate that the proposed VCL can effectively improve the generalization of HOI detection on HICO-DET and V-COCO and outperforms the recent state-of-the-art methods on HICO-DET. Code is available at https://github.com/zhihou7/VCL.Comment: Accepted in ECCV202