Yimeng Zhang

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The most popular approach to large scale image retrieval is based on the bag-of-visual-word (BoV) representation of images. The spatial information is usually reintroduced as a post-processing step to re-rank the retrieved images, through a spatial verification like RANSAC. Since the spatial verification techniques are computationally expensive, they can be(More)
The local feature based approaches have become popular for activity recognition. A local feature captures the local movement and appearance of a local region in a video, and thus can be ambiguous; e.g., it cannot tell whether a movement is from a person’s hand or foot, when the camera is far away from the person. To better distinguish different types of(More)
The Conditional Random Field (CRF) is a popular tool for object-based image segmentation. CRFs used in practice typically have edges only between adjacent image pixels. To represent object relationship statistics beyond adjacent pixels, prior work either represents only weak spatial information using the segmented regions, or encodes only global object(More)
The sliding window approach has been widely used for object detection because it provides a simple way to apply object recognition techniques to the detection task. Despite its effectiveness, though, the exhaustive search makes the approach inefficient in the case of a non-trivial classifier. The branch and bound techniques [3, 4] have been proposed in(More)
A method of blind recognition of the coding parameters for binary Bose-Chaudhuri-Hocquenghem (BCH) codes is proposed in this paper. We consider an intelligent communication receiver which can blindly recognize the coding parameters of the received data stream. The only knowledge is that the stream is encoded using binary BCH codes, while the coding(More)
A new method to measure moisture content of material is described in this paper. The method is based on two phase shifts of transmitted microwave signal at two different frequencies. The result using this method for moisture measurement of timber indicates this method being effective. The maximum error and mean value of error in moisture range from 2 to 30%(More)
BACKGROUND The risk of sexual HIV transmission in serodiscordant couples when the HIV-positive partner has full virologic suppression on combination antiretroviral therapy (cART) is debated. This study aims to systematically review observational studies and randomized controlled trials (RCTs), evaluating rates of sexual HIV transmission between heterosexual(More)
This study aimed to understand gender and ethnicity differences in HIV-related stigma experienced by 1026 HIV-positive individuals living in Ontario, Canada that were enrolled in the OHTN Cohort Study. Total and subscale HIV-related stigma scores were measured using the revised HIV-related Stigma Scale. Correlates of total stigma scores were assessed in(More)
The "bag of features" (BoF) representation of images [5] has been extremely popular for object categorization task due to its advantages of great invariance and computational simplicity. High order features have been proposed to model the mutual geometrical relationship between the local features [2, 3, 4, 6]. High order features (HOFs) are created to(More)