The Experts below are selected from a list of 14187 Experts worldwide ranked by ideXlab platform

Gang Qiao - One of the best experts on this subject based on the ideXlab platform.

  • Impervious Surface Information Extraction Using an Improved Object-Oriented Method
    2011 International Symposium on Image and Data Fusion, 2011
    Co-Authors: Guodan Kuang, Weian Wang, Gang Qiao
    Abstract:

    Impervious surface, where water cannot infiltrate the soil, including roads, driveways, sidewalks, parking lots, rooftops, and so on, has been recognized as an important indicator in urban environment. However, accurate extraction of impervious surface information from imagery is still a challenge in remote sensing society. This paper explores extraction of impervious surface information with QuickBird imagery based on improved object-Oriented. Firstly, MNF (minimum noise fraction) was used to achieve end members. Secondly, vegetation fraction image was produced by linear spectral mixture analysis. Thirdly, three urban land-use classes were developed based on object-Oriented Method. Results showed that dark impervious objects from shadows cast by tall building and tree canopy had been separated from water.

Guodan Kuang - One of the best experts on this subject based on the ideXlab platform.

  • Impervious Surface Information Extraction Using an Improved Object-Oriented Method
    2011 International Symposium on Image and Data Fusion, 2011
    Co-Authors: Guodan Kuang, Weian Wang, Gang Qiao
    Abstract:

    Impervious surface, where water cannot infiltrate the soil, including roads, driveways, sidewalks, parking lots, rooftops, and so on, has been recognized as an important indicator in urban environment. However, accurate extraction of impervious surface information from imagery is still a challenge in remote sensing society. This paper explores extraction of impervious surface information with QuickBird imagery based on improved object-Oriented. Firstly, MNF (minimum noise fraction) was used to achieve end members. Secondly, vegetation fraction image was produced by linear spectral mixture analysis. Thirdly, three urban land-use classes were developed based on object-Oriented Method. Results showed that dark impervious objects from shadows cast by tall building and tree canopy had been separated from water.

Guofan Jin - One of the best experts on this subject based on the ideXlab platform.

  • Accurate calculation of computer-generated holograms using angular-spectrum layer-Oriented Method
    Optics Express, 2015
    Co-Authors: Liangcai Cao, Guofan Jin, Dezhao Kong, Hao Zhang, Yan Zhao
    Abstract:

    Fast calculation and correct depth cue are crucial issues in the calculation of computer-generated hologram (CGH) for high quality three-dimensional (3-D) display. An angular-spectrum based algorithm for layer-Oriented CGH is proposed. Angular spectra from each layer are synthesized as a layer-corresponded sub-hologram based on the fast Fourier transform without paraxial approximation. The proposed Method can avoid the huge computational cost of the point-Oriented Method and yield accurate predictions of the whole diffracted field compared with other layer-Oriented Methods. CGHs of versatile formats of 3-D digital scenes, including computed tomography and 3-D digital models, are demonstrated with precise depth performance and advanced image quality.

Lei Wang - One of the best experts on this subject based on the ideXlab platform.

  • An Incremental Weibo-Oriented Method for Unknown Word and Topic Extraction
    2013 Ninth International Conference on Semantics Knowledge and Grids, 2013
    Co-Authors: Lei Wang
    Abstract:

    Due to the great flexibility in wording and highly correlation between unknown words and unpredictable topics, which are exhibited in Chinese twitter (i.e. weibo) messages, it proposed a weibo-Oriented Method to detect unknown words and topics simultaneously. The Method is efficient and precise, however, because of the adopted classical K-means algorithm, it cannot deal with weibo corpus with increasing size. In this paper, a modified version is presented to eliminate the limitation by incorporating incremental clustering mechanism. Based on the weibo characteristics, a new similarity measure is introduced, which takes into considerations the relevance of the recently identified unknown words. With this measure, the categories evolution is reasonably carried out in the process of incremental clustering to ensure the balance between the consistency and timeliness of the Method. Experiments show that unknown words and topics can be effectively detected and tracked.

  • A Weibo-Oriented Method for Unknown Word Extraction
    2012 Eighth International Conference on Semantics Knowledge and Grids, 2012
    Co-Authors: Shuai Zhang, Lei Wang
    Abstract:

    Unknown word recognition is one of the most prominent and challenging problems in the Chinese language processing. Some effective approaches have been proposed, however, they do not work well on Chinese twitter (i.e. weibo) messages. In this paper, a Method is presented to recognize unknown words from weibo. Due to the great flexibility in wording and highly correlation between unknown words and unpredictable topics, which are exhibited in weibo messages, the proposed Method firstly groups the corpus into multiple categories by using K-means, then, from each of the categories, a morpheme set is derived based on local terms frequencies. Secondly, as for each potential unknown word in every morpheme set, a newly introduced measure (named adjacency degree) is calculated to see if a correct unknown word is found. It could be shown by the experiments that the proposed Method is efficient, precise, and insensitive to the size of the weibo corpus.

Yan Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Catheter Tracking Based on Multi-scale Filter and Direction-Oriented Method
    2018 IEEE International Conference on Mechatronics and Automation (ICMA), 2018
    Co-Authors: Yuwen Zeng, Yan Zhao, Nan Xiao, Yuxin Wang
    Abstract:

    Nowadays the morbidity and mortality of cardiovascular and cerebrovascular diseases are increasing year by year. Vascular interventional surgery has been considered as the most widely treatment to these diseases and it is developing rapidly for its minimally invasive procedure, safety and short recovery time. However, due to the low signal-to-noise ratio (SNR) and pipe-like structures in the human body, the resolution of fluoroscopic sequences can be too low for surgeons to recognize the catheter in some cases, which impose restrictions on the performance and efficiency of this surgery in clinic. Therefore, enhancing and tracking the catheter in the endovascular interventions have become a crucial part. This paper proposes a morphologic Method based on multiscale filter and direction-Oriented Method, which can enhance and detect the catheter from sequences in real-time. And finally this Method takes 0.064s per frame with an accuracy of 89.39%, which can meet the requirements of clinic operations.

  • Accurate calculation of computer-generated holograms using angular-spectrum layer-Oriented Method
    Optics Express, 2015
    Co-Authors: Liangcai Cao, Guofan Jin, Dezhao Kong, Hao Zhang, Yan Zhao
    Abstract:

    Fast calculation and correct depth cue are crucial issues in the calculation of computer-generated hologram (CGH) for high quality three-dimensional (3-D) display. An angular-spectrum based algorithm for layer-Oriented CGH is proposed. Angular spectra from each layer are synthesized as a layer-corresponded sub-hologram based on the fast Fourier transform without paraxial approximation. The proposed Method can avoid the huge computational cost of the point-Oriented Method and yield accurate predictions of the whole diffracted field compared with other layer-Oriented Methods. CGHs of versatile formats of 3-D digital scenes, including computed tomography and 3-D digital models, are demonstrated with precise depth performance and advanced image quality.