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Weakly supervised object detection (WSOD) is a challenging task that requires simultaneously learning object detectors and estimating object locations under the supervision of image category labels. Many WSOD methods that adopt multiple instance learning (MIL) have nonconvex objective functions and, therefore, are prone to get stuck in local minima (falsely localize object parts) while missing full object extent during training. In this article, we introduce classical continuation optimization into MIL, thereby creating continuation MIL (C-MIL) with the aim to alleviate the nonconvexity problem in a systematic way. To fulfill this purpose, we partition instances into class-related and spatially related subsets and approximate MIL’s objective function with a series of smoothed objective functions defined within the subsets. We further propose a parametric strategy to implement continuation smooth functions, which enables C-MIL to be applied to instance selection tasks in a uniform manner. Optimizing smoothed loss functions prevents the training procedure from falling prematurely into local minima and facilities learning full object extent. Extensive experiments demonstrate the superiority of CMIL over conventional MIL methods. As a general instance selection method, C-MIL is also applied to supervised object detection to optimize anchors/features, improving the detection performance with a significant margin. [ABSTRACT FROM AUTHOR]

Organizing multimodal Web pages into hot topics is the core step to grasp trends on the Web. However, the less-constrained social media generate noisy user-generated content, which makes a detected topic be less coherent and less interpretable. In this paper, we address this problem by proposing a coupled Poisson deconvolution to jointly handle topic detection and topic description. For the topic detection, the interestingness of a topic is estimated from the similarities refined by the description of topics; for the topic description, the interestingness of topics is leveraged to describe topics. Two processes cyclically detect interesting topics and generate the multimodal description of topics. This is the innovation of this paper, which just likes killing two birds with one stone. Experiments not only show the significantly improved accuracies for the topic detection but also demonstrate the interpretable descriptions for the topic description on two public data sets. [ABSTRACT FROM AUTHOR]