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Yongjun P.,Communication Command Academy of PLA | Peng S.,Communication Command Academy of PLA | Xi G.,Wuhan University | Huang Z.,Communication Command Academy of PLA | And 2 more authors.
ICCET 2010 - 2010 International Conference on Computer Engineering and Technology, Proceedings | Year: 2010

With the rapid development of industrialization and urbanization, the security situation faced by our country is more severe and complex. In the field of the social security prevention and control, various safety and security measures and installations have come into full play, but in them, there are some weak points, such as improper designs and the separation of people's prevention from the material prevention and the technical prevention. The effectiveness evaluation on the security and prevention system has often emphasized particularly the aspects of the management and experiences, lacking in the theoretical and technical ways and means to do scientific quantitative evaluations. It is hard to support the formation and establishment of the complete, high-efficient and integrated prevention and control systems, so the research on the prevention and protection capability of security and prevention installations and the risk prediction technology, and the establishment of the objective, efficiency-and-risk evaluation architecture of the system prevention and protection are one of the major strategic tasks in the field of the national security prevention development at present. The thesis makes a complete carding and sum-up of the present theories, ways and means of the effectiveness evaluation, which is of great scientific importance to establishing the emergency public security architecture with scientific prediction, effective prevention and control, and high efficiency. © 2010 IEEE.


Li H.,China University of Geosciences | Li H.,Wuhan University | Zhong C.,Wuhan University | Zhong C.,Wuhan Urban Planning Information Center | And 2 more authors.
Journal of Geomatics | Year: 2010

Nowadays, the research on road extraction and reconstruction is very popular, especially on the road reconstruction merged with remote sensing images and LiDAR data. The road extraction from remote sensing images assistant with LiDAR height information get pretty well concerned. The development is reviewed in order to help researchers in related field.


Zhong C.,China University of Geosciences | Li H.,China University of Geosciences | Li Z.,Wuhan Urban Planning Information Center | Li D.,Wuhan University
GIScience and Remote Sensing | Year: 2010

One of the problems in detecting occlusions when generating true ortho photos is false occlusion and false visibility caused by rolling terrain, and the resolution difference between the digital surface model (DSM) and the images. Published methods are plagued by unstable computation and have considerable noise. The paper presents a vector-based backward projection (VBP) method for detecting occlusions. First, the method projects vector polygons representing the surface of buildings to image space. Next, it derives their true coverage by judging the occupancy priority for the overlap. It then determines the visibility of building and digital elevation model (DEM) grids. Finally, it generates a true ortho image by differential rectification. In addition, this paper develops methods to keep all steps robust, such as dubious region growing methods for rasterization and judgment formulas for boundary noise elimination, which makes VBP practical. Experiments using the Z-Buffer method, the projection-ray-angle-based method and VBP with a typical image and DSM prove VBP has 100% detection accuracy, and is robust and efficient.


Zhong C.,Wuhan Urban Planning Information Center | Huang X.,Wuhan University | Li D.,Wuhan University | Li H.,China University of Geosciences
Acta Geodaetica et Cartographica Sinica | Year: 2010

Occlusion detection is crucial to orthophoto generation. This paper proposes the polygon based inversion imaging (PBI) method for occlusion detection. The proposed method projects building surface polygon to image space according to the characteristic that there is no occlusion in one polygon, then inverse the status of objects and occlusions between objects. In this process, (1)Doubtable region growing method is proposed to grid complex 3D building models, and (2) comprehensive filter model is put forward to eliminate noises around polygon boundaries. Experiments on z-buffer method, angle based method and PBI method with typical image and DSM prove the validity and robustness of the proposed method.


Zhong C.,China Three Gorges University | Zhong C.,Wuhan University | Li H.,University of Science and Technology of China | Li Z.,Wuhan Urban Planning Information Center | Li D.,Wuhan University
Acta Geodaetica et Cartographica Sinica | Year: 2010

It is presented that the crucial factor for the quality of coordinate transformation is the signal-to-noise ratio (SNR) of common points, so differences among transformation models are their simulation ability of signals, detectability and defensibility of noises. Then, a new quality evaluation system of coordinate transformation, including reliability indicators and simulation indicators, is put forward. The reliability indicators include the redundant observation components, inner and external reliability, which imply the geometry condition, detectability and defensibility of noises respectively; the simulation indicators include precision, expansibility, invertibility and uniqueness, which imply the simulation ability for various requirements. Experiment has verified the feasibility, necessity and validity of the indicators, and investigated affects of geometrical conditions and transformation methods on the indicators. At last, it is pointed out that some methods to improve geometrical conditions, and the applicable condition for transformation methods with their performances on the indicators above.


Chun-Hui Y.,Wuhan Urban Planning Information Center | Xin C.,Huazhong University of Science and Technology
Proceedings - 2nd International Conference on Information Technology and Computer Science, ITCS 2010 | Year: 2010

In this paper, a realization scheme for CPRI protocol based on high-speed fiber link is proposed. FPGA and SerDes are adopted in the design of hardware structure. The standard CPRI protocol and optical fiber channel protocol are introduced briefly. According those, CPRI protocol architecture based on optical fiber links is proposed. Hardware design of protocol interface and realization of every layer are discussed, and internal structure block diagram of CPRI protocol based on verilog and realization details concerned are provided. Finally, experiment for high-speed fiber link is introduced and the analysis for experiment result is offered. Through this analysis, it is shown that the design of CPRI protocol architecture is suit for practice application. © 2010 IEEE.


Luo Q.,Wuhan Urban Planning Information Center | Chen S.,Wuhan Urban Planning Information Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

Rapid urbanization is the main driving force of land cover change in metropolitan Wuhan. This is especially critical with respect to the many lakes and shallow water bodies. Land cover changes from 1991 to 2006 were mapped by classifying Landsat TM images (1991, 2002, and 2006). Different band combinations were used to build high-quality false-color images; the spectral separability of sets of training pixels was then evaluated by contingency matrices and feature space plots. Maximum likelihood supervised classification was applied to extract built-up areas, vegetated areas and water bodies. Post-classification was carried out to detect the land cover changes. From the classification, vegetation and built-up areas expanded at the expense of water bodies. Further comparison of the variety in LULC was analyzed in both temporal and spatial aspects between 1991-2002 and 2002-2006. The growth rate of built-up area from 2002-2006 is 55.7%, which is much higher than the rate from 1991 to 2002, whereas water bodies decreased more in the first period. Vegetation increased in the first period and then decreased slightly in the second. This analysis showed urban expansion is mainly along Yangtze River and along the East-West axis. These spatio-temporal characteristics should allow urban planners to better understand the processes of urban sprawl in Wuhan.© 2010 SPIE.

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