Journals
  Publication Years
  Keywords
Search within results Open Search
Please wait a minute...
For Selected: Toggle Thumbnails
Coupling similarity-based approach for categorizing spatial database query results
BI Chongchun, MENG Xiangfu, ZHANG Xiaoyan, TANG Yanhuan, TANG Xiaoliang, LIANG Haibo
Journal of Computer Applications    2018, 38 (1): 152-158.   DOI: 10.11772/j.issn.1001-9081.2017051219
Abstract451)      PDF (1316KB)(387)       Save
A common spatial query often leads to the problem of multiple query results because a spatial database usually contains large size of data. To deal with this problem, a new categorization approach for spatial database query results was proposed. The solution consists of two steps. In the offline step, the coupling relationship between spatial objects was evaluated by considering the location proximity and semantic similarity between them, and then a set of clusters over the spatial objects could be generated by using probability density-based clustering method, where each cluster represented one type of user requirements. In the online query step, for a given spatial query, a category tree for the user was dynamically generated by using the modified C4.5 decision tree algorithm over the clusters, so that the user could easily select the subset of query results matching his/her needs by exploring the labels assigned on intermediate nodes of the tree. The experimental results demonstrate that the proposed spatial object clustering method can efficiently capture both the semantic and location relationships between spatial objects. The query result categorization algorithm has good effectiveness and low search cost.
Reference | Related Articles | Metrics
MAP super-resolution reconstruction based on adaptive constraint regularization HL-MRF prior model
QIN Longlong, QIAN Yuan, ZHANG Xiaoyan, HOU Xue, ZHOU Qin
Journal of Computer Applications    2015, 35 (2): 506-509.   DOI: 10.11772/j.issn.1001-9081.2015.02.0506
Abstract975)      PDF (716KB)(350)       Save

Aiming at the poor suppression ability for the high-frequency noise in Huber-MRF prior model and the excessive punishment for the high frequency information of image in Gauss-MRF prior model, an adaptive regularization HL-MRF model was proposed. The method combined low frequency function of Huber edge punishment with high frequency function of Lorentzian edge punishment to realize a linear constraint for low frequency and a less punishment for high frequency. The model gained its optimal solution of parameters by using adaptive constraint method to determine regularization parameter. Compared with super-resolution reconstruction methods based on Gauss-MRF prior model and Huber-MRF prior model, the method based on HL-MRF prior model obtains higer Peak Signal-to-Noise Ratio (PSNR) and better performace in details, therefore it has ceratin advantage to suppress the high frequency noise and avoid excessively smoothing image details.

Reference | Related Articles | Metrics