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Displaying results 1 - 8 of 15
  • Dual Graph Spatial Cluster Detection for Syndromic Surveillance in Networks

    Content Type: Abstract

    Early warning systems must not always rely on geographical proximity for modeling the spread of contagious diseases. Instead, graph structures such as airways or social networks are more adequate in those situations. Nodes,… read more
    … difficulties for the direct usage of scan statistics, due to the highly irregular structures involved. Besides, … the appearance of an emerging cluster of syndromes due to a real outbreak (signal) amidst unrelated syndromes … the appearance of an emerging cluster of syndromes due to a real out- break (signal) amidst unrelated syndromes …
  • Spatial Scan Statistics for Models with Excess Zeros and Overdispersion

    Content Type: Abstract

    Spatial Scan Statistics [1] usually assume Poisson or Binomial distributed data, which is not adequate in many disease surveillance scenarios. For example, small areas distant from hospitals may exhibit a smaller number of cases than expected in… read more
    … Also, underreporting may occur in underdeveloped regions, due to inefficient data collection or the difficulty to … Also, underreporting may occur in underdeveloped regions, due to inefficient data collection or the difficulty to …
  • Spatial cluster detection through constrained dynamic programming

    Content Type: Abstract

    The spatial scan statistic [1] is the most used measure for cluster strenght. The evaluation of all possible subsets of regions in a large dataset is computationally infeasible. Many heuristics have appeared recently to compute approximate values… read more
    … most used measure for cluster strenght. The evaluation of all possible subsets of regions in a large dataset is … and Ricardo H. C. Takahashi2 1Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil; 2Universidade Federal … most used measure for cluster strenght. The evaluation of all possible subsets of regions in a large dataset is …
  • Delineating Spatial Clusters with Artificial Neural Networks

    Content Type: Abstract

    Multiple or irregularly shaped spatial clusters are often found in disease or syndromic surveillance maps. We develop a novel method to delineate the contours of spatial clusters, especially when there is not a clearly dominating primary cluster,… read more
    … Ricardo H.C. Takahashi, Luiz Duczmal Universidade Federal de Minas Gerais, Brazil OBJECTIVE Multiple or irregularly … more irregularly shaped clusters, indicating less bias, due to the larger variance allowed. CONCLUSIONS The … A Spatial Scan Statistic, Comm. Statist. Theory Meth., 26(6), 1481-1496. [2] M. H. Fun and M.T. Hagan, 1996. …
  • Exploring Multi-Cluster Structures with the Multi-Objective Circular Scan

    Content Type: Abstract

    The spatial scan statistic is the usual measure of strength of a cluster [1]. Another important measure is its geometric regularity [2]. A genetic multiobjective algorithm was developed elsewhere to identify irregularly shaped clusters [3]. A search… read more
    … The solution presented is a Pareto-set, consisting of all the clusters found which are not simultaneously worse in … A significance evaluation is conducted in parallel for all clusters in the Pareto-set through Monte Carlo … The solution presented is a Pareto-set, consisting of all the clusters found which are not simultaneously worse in …
  • Geographically Meaningful Cluster Scanning Through Weak Link Correction

    Content Type: Abstract

    Many heuristics were developed recently to find arbitrarily shaped clusters (see  review  [1]). The most popular statistic is the spatial scan  [2]. Nevertheless, even if all cluster solutions could be known, the problem  of… read more
    … statistic is the spatial scan  [2]. Nevertheless, even if all cluster solutions could be known, the problem … solution presented is a Pareto-set, consisting of all the clusters found which are not simultaneously worse in … The significance evaluation is conducted in parallel for all the  clusters  in  the  Pareto-set  through a …
  • A new interpretation of the inference test for the spatial scan statistic

    Content Type: Abstract

    Spatial cluster analysis is considered an important technique for the elucidation of disease causes and epidemiological surveillance. Kulldorff's spatial scan statistic, defined as a likelihood ratio, is the usual measure of the strength of… read more
    … work, this adjustment is not done in an even manner for all possible cluster sizes. We propose a modification to the … and Ricardo H. Caldeira Takahashi4 1Universidade Federal de São João del Rei, Ouro Branco, Brazil; 2Statistics, … work, this adjustment is not done in an even manner for all possible cluster sizes (3). Methods We pose a modified …
  • Adaptive Likelihood Ratio Methods for the Detection of Space-Time Disease Clusters

    Content Type: Abstract

    Data obtained through public health surveillance systems are used to detect and locate clusters of cases of diseases in space-time, which may indicate the occurrence of an outbreak or an epidemic. We present a methodology based on adaptive… read more
    … the detection of space-time disease clusters Max Sousa de Lima1* and Luiz Duczmal2 1Universidade Federal do … disease clusters using scan statistic. Stat Med. 2007;26:4770�89. 3. Porter DM. Some adaptive approaches for … permitting all non-commercial use, distribution, and reproduction in …