State Key Laboratory of Geography Information Engineering

Xi’an, China

State Key Laboratory of Geography Information Engineering

Xi’an, China
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Chen Z.,Wuhan University of Technology | Chen Z.,State Key Laboratory of Geography Information Engineering | Wu L.,Wuhan University of Technology | Ma J.,Wuhan University of Technology | Zheng K.,Wuhan University of Technology
Journal of Software Engineering | Year: 2015

String mode matching is a classical computer research question and one of many key technologies in the network security system. With the hardware technology and network technology development in information age. Big data processing and application requirements for new string matching technology presents new challenges. Suffix array is a string matching and efficient data structure. It solves a lot of complex queries in text database application. This study focuses on the system architecture of multi-core computing environment characterized, optimization and improved suffix array algorithm, enhancement algorithm execution performance, improve the efficiency of the parallel algorithm. Finally, compared with the BF algorithm and the serial algorithm of suffix array. Conclusions drawn parallel string pattern matching algorithm to improve application performance optimization and save hardware cost of great significance. © 2015 Academic Journals Inc.


Yang L.,China University of Geosciences | Yang L.,State Key Laboratory of Geography Information Engineering | Wan B.,China University of Geosciences | Wang R.,China University of Geosciences | And 3 more authors.
Wuhan Daxue Xuebao (Xinxi Kexue Ban)/Geomatics and Information Science of Wuhan University | Year: 2015

From the visual attention mechanism when people are looking for the sameroad, this paper proposed a road network matching method based on hierarchical stable strokes. The method adopts the principle of matching from obvious to vital, and constructs larger matching unit "stroke" instead of "road section". First, the correspondence of strokes is calculated; Then, the detailed node correspondence is further identified. The results show that: when calculating similarity, the differences rate between candidate strokes and the largest reference solution is more significant than that of road segment. In this example, 10 percent of the first layer strokes can ensure the stability of the matching relationship. Layered stable reference and hierarchical strokes improves the ability to identify matching relation, and it has obvious advantages in the region with similar local structure and obviously different global strokes. © 2015, Wuhan University All right reserved.


Yang L.,Wuhan University | Yang L.,State Key Laboratory of Geography Information Engineering | Zuo Z.,Wuhan University | Zuo Z.,State Key Laboratory of Geography Information Engineering | And 6 more authors.
Open Automation and Control Systems Journal | Year: 2014

Aiming at the complex multisource road network matching modes, this paper proposed a road network matching method based on hierarchical stable strokes. The progress of the matching method adopts recursive method and gives consideration to both global consistency and local similarity of homonymous road features. One layer of hierarchical strokes generating from road spatial structure are selected at a match and the matched parts are used as a stable reference for the next layer. The detailed matching is implemented by an iterative probability relaxation method. In the course of coarse matching three similarity indicators, including the geometry shape similarity of strokes, the relative position of nodes and strokes and the topological structure similarity of nodes, are introduced into the initial matching probability calculation. After that, an iterative calculation is carried out for updating matching probability. Finally, a self-designed selecting principle is applied to trace the exact matching results. Matching road centerline from different producers of the same geographical area shows that our method finds 1:1, 1:N and M:N matching modes and gets a satisfactory matching result, which means hierarchical stable reference and the stroke structure can provide an effective way to identify different matching relations and avoid the non-rigid deviation of the homonymous features. © Yang et al.; Licensee Bentham Open.


Chen Z.,Wuhan University | Chen Z.,State Key Laboratory of Geography Information Engineering | Feng Q.,Wuhan University | Wu X.,Wuhan University
Cehui Xuebao/Acta Geodaetica et Cartographica Sinica | Year: 2015

In order to express the details of the topological relations between complex planar objects, the classic 9-intersection model is improved and the two extended 9-intersection models that based on decomposition ideas are proposed: the one 9-intersection model method that is decomposed into simple area has its advantage of simplification, but at the cost of complicated expressions; another 9-intersection model method that is decomposed into point-set, conforming well with the classical 9-intersection model, but has relatively complex calculations. Compared the expressive abilities between the two kinds of extened 9-intersection models and the classic 9-intersection model by examples. The results show that both the two extended 9-intersection models can give more accurately expression of the topological relations between details of the sub parts in complex planar objects, the expressive ability of 9-intersection model has been expanded and improved. ©, 2015, SinoMaps Press. All right reserved.


Xu Y.,Wuhan University | Xie Z.,Wuhan University | Chen Z.,Wuhan University | Chen Z.,State Key Laboratory of Geography Information Engineering | Wu L.,Wuhan University
International Journal of Geographical Information Science | Year: 2016

In geographic information retrieval and spatial data mining, similarity is used to resolve shape matching and clustering. Many approaches have been developed to calculate similarity between simple geometric shapes. However, complex spatial objects are common in spatial database systems, spatial query languages and Geographic Information Science (GIS) applications. With holed polygons, many similarity measurement approaches are restricted to address the relationships between holes or between the holes and the entire complex geometric shape. A successful method should remove the restrictions due to these complex relations and retain invariant during geometric translation (rotation, moving and scaling). To overcome these deficiencies, we utilize position graphs to describe the distribution of holes in complex geometric shapes by storing invariants, such as angles and distances. In addition, Fourier descriptors and the position graph-based method are used to measure the similarity between holed polygons. Experiments show that the proposed method takes into account the relationships in an entire complex geometric shape. It can effectively calculate the similarity of holed polygons, even if they contain different numbers of holes. © 2016 Informa UK Limited, trading as Taylor & Francis Group


Chen Z.,Wuhan University | Chen Z.,State Key Laboratory of Geography Information Engineering | Qin M.,Wuhan University | Wu L.,Wuhan University | Xie Z.,Wuhan University
Cehui Xuebao/Acta Geodaetica et Cartographica Sinica | Year: 2016

A method about shape similarity measurement of complex holed objects is proposed in this paper. The method extracts features including centroid distance, multilevel chord length, bending degree and concavity-convexity of a geometric object, to construct complex functions based on multilevel bending degree and radius. The complex functions are capable of describing geometry shape from entirety to part. The similarity between geometric objects can be measured by the shape descriptor which is based on the fast Fourier transform of the complex functions. Meanwhile, the matching degree of each scene of complex holed polygons can be got by scene completeness and shape similarity model. And using the feature of multi-level can accomplish the shape similarity measurement among complex geometric objects. Experimenting on geometric objects of different space complexity, the results match human's perceive and show that this method is simple with precision. © 2016, Surveying and Mapping Press. All right reserved.


Chen Z.,Wuhan University | Chen Z.,State Key Laboratory of Geography Information Engineering | Gong X.,Wuhan University | Wu L.,Wuhan University | And 2 more authors.
Cehui Xuebao/Acta Geodaetica et Cartographica Sinica | Year: 2016

This article introduces a new model for direction relations between multiple spatial objects at multiple scales and a corresponding similarity assessment method. The model is an improvement of direction relation matrix, which quantitatively models direction relations on object scale, and by the idea of decomposition and means of the optimum solution of the transportation problem to solve the minimum conversion cost between multiple direction matrices, namely distance between a pair of matrices, thus quantified the difference between a pair of directions, finally obtain the similarity values between arbitrary pairs of multiple spatial objects and compare the results. Experiments on calculating similarity between objects at different scales show that the presented method is efficient, accurate, and capable of obtaining results consistent with human cognition. © 2016, Surveying and Mapping Press. All right reserved.

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