3,822 research outputs found

    Wavelet based independent component analysis for palmprint identification

    Get PDF
    Author name used in this publication: David ZhangVersion of RecordPublishe

    Supervised LLE in ICA space for facial expression recognition

    Get PDF
    Author name used in this publication: David ZhangRefereed conference paper2005-2006 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    Bagging evolutionary feature extraction algorithm for classification

    Get PDF
    Author name used in this publication: David ZhangBiometrics Research Centre, Department of ComputingVersion of RecordPublishe

    Robust filtering for uncertain discrete-time systems : an improved LMI approach

    Get PDF
    Author name used in this publication: David ZhangVersion of RecordPublishe

    Method of palm print identification

    Get PDF
    US7496214; US7496214 B2; US7496214B2; US7,496,214; US 7,496,214 B2; 7496214; Application No. 10/865,604Inventor name used in this publication: Dapeng David ZhangInventor name used in this publication: Jia Jane YouInventor name used in this publication: Wai Kin Adams KongUSVersion of Recor

    Performance Enhancement of High Step-up DC-DC Converter to Attain High Efficiency and Low Voltage Stress

    Full text link
    This study proposes a new high voltage gain and high-efficiency DC-DC converter to interface renewable energy resources into dc nanogrid. The proposed topology is formed by a coupled inductor to achieve high voltage gain and low stress on the active switch. The switch voltage stress is significantly low compared to the output voltage. Thus, efficiency is improved by utilizing a low voltage rating MOSFET. Furthermore, the utilization of couple inductor eliminated the reverse recovery losses of diodes. The converter consists of the least number of components that decrease the overall system cost. The steady-state operation and analysis of the proposed converter are discussed comprehensively. The experimental performance is verified by building and testing a prototype in the laboratory. The experimental results prove the consistency with the theoretical analysis. The converter depicts a peak efficiency of 97.10% in the laboratory

    Browse-to-search

    Full text link
    This demonstration presents a novel interactive online shopping application based on visual search technologies. When users want to buy something on a shopping site, they usually have the requirement of looking for related information from other web sites. Therefore users need to switch between the web page being browsed and other websites that provide search results. The proposed application enables users to naturally search products of interest when they browse a web page, and make their even causal purchase intent easily satisfied. The interactive shopping experience is characterized by: 1) in session - it allows users to specify the purchase intent in the browsing session, instead of leaving the current page and navigating to other websites; 2) in context - -the browsed web page provides implicit context information which helps infer user purchase preferences; 3) in focus - users easily specify their search interest using gesture on touch devices and do not need to formulate queries in search box; 4) natural-gesture inputs and visual-based search provides users a natural shopping experience. The system is evaluated against a data set consisting of several millions commercial product images. © 2012 Authors

    Implementation of Web-Based Respondent-Driven Sampling among Men who Have Sex with Men in Vietnam

    Get PDF
    Objective: Lack of representative data about hidden groups, like men who have sex with men (MSM), hinders an evidence-based response to the HIV epidemics. Respondent-driven sampling (RDS) was developed to overcome sampling challenges in studies of populations like MSM for which sampling frames are absent. Internet-based RDS (webRDS) can potentially circumvent limitations of the original RDS method. We aimed to implement and evaluate webRDS among a hidden population. Methods and Design: This cross-sectional study took place 18 February to 12 April, 2011 among MSM in Vietnam. Inclusion criteria were men, aged 18 and above, who had ever had sex with another man and were living in Vietnam. Participants were invited by an MSM friend, logged in, and answered a survey. Participants could recruit up to four MSM friends. We evaluated the system by its success in generating sustained recruitment and the degree to which the sample compositions stabilized with increasing sample size. Results: Twenty starting participants generated 676 participants over 24 recruitment waves. Analyses did not show evidence of bias due to ineligible participation. Estimated mean age was 22 year and 82% came from the two large metropolitan areas. 32 out of 63 provinces were represented. The median number of sexual partners during the last six months was two. The sample composition stabilized well for 16 out of 17 variables. Conclusion: Results indicate that webRDS could be implemented at a low cost among Internet-using MSM in Vietnam. WebRDS may be a promising method for sampling of Internet-using MSM and other hidden groups. Key words: Respondent-driven sampling, Online sampling, Men who have sex with men, Vietnam, Sexual risk behavio

    Evolutionary discriminant feature extraction with application to face recognition

    Get PDF
    Author name used in this publication: David Zhang2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Simple and Fast Dynamic Photovoltaic Emulator based on a Physical Equivalent PV‐cell Model

    Full text link
    Photovoltaic emulators are a specific type of power electronics system to mimic the behaviour of a photovoltaic (PV) panel or array and facilitate the testing of energy systems. Existing solutions usually require sophisticated hardware design and fast computing. This paper presents a simple, reliable, and effective circuit-based photovoltaic (PV) emulator based on the equivalent PV stacked cells. The PV emulator can be used for solar system testing and analysis, such as maximum power point tracking (MPPT) and partial shading effect. The – and – characteristic curves of the emulator have been generated by using an LTspice simulator. It is experimentally investigated and compared with a real PV panel and existing emulator products. The experiment results show good agreement with the mimicked actual PV panel. The proposed PV emulator shows a better dynamic response and shorter settling time than several benchmarked commercial products. The enhancement in the time response is due to the simplicity of the emulator, where a few power diodes and some resisters are used. In addition to simplicity, the PV emulator is very cost-effective
    corecore