Entity

Time filter

Source Type


Haitao Z.,National Quality Inspection and Testing Center for Surveying and Mapping Products | Xuefang L.,Beijing University of Civil Engineering and Architecture | Xiaorong G.,GanSu Provincial Geomatics Center
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences - ISPRS Archives | Year: 2013

For Chinese paper charts, no standards are made yet, quality of paper charts are controlled by "there-level inspection" with naked eyes at present. This method has many disadvantages like more errors, more omissions, low efficiency and resource wastes etc. But paper charts can not be totally replaced by electronic charts in a short time. Thus, the research on new quality inspection method for paper charts in digital age is absolutely necessary. Aiming at the production of paper charts in digital environment, a new quality inspection method based on entity rules and cartographic specifications is put forward in this paper. Firstly, considering the fact that updating speed of charts database is closely related to the changing speed of maritime objects, each category of maritime features are analyzed from different aspects including their attributes, symbols, entity rules, changing features, etc. Based on this, features are classified into three categories according to their changing features to make sure that proper quality inspection method will be applied to certain features. The three categories are as follows: low changing speed, fast changing speed with regulations, fast changing speed without regulations. At the same time, rules of each feature and its relationships with some other features are analyzed, too, for all those changing speed and rules, relationships are the most important factors when design inspection methods for each kind of features. Secondly, the concept of inspection method based on entity rules and cartographic specifications are introduced. Source


Zhan W.,First Crust Monitoring and Application Center | Wu Y.-Q.,First Crust Monitoring and Application Center | Zhang L.-B.,National Quality Inspection and Testing Center for Surveying and Mapping Products | Zhu S.,First Crust Monitoring and Application Center | Meng X.-G.,First Crust Monitoring and Application Center
Earthquake | Year: 2014

Aiming at sub-network division of GNSS continuous stations in TEONET (Tectonic and Environmental Observation Network in China), we design three schemes to process the data from doy 110 in 2010 to doy 103 in 2013. The first scheme (referred as regional scheme) has six regional sub-networks and each sub-network includes 55 GNSS permanent stations. The second scheme (named large-net scheme) has three sub-networks and each has 100 stations selected evenly in mainland China. The third scheme (named small-net scheme) has eight sub-networks and each has 55 stations selected evenly. Meanwhile, we analyze the differences between the results including station coordinates, horizontal velocity field and baseline length. The results show that the differences are within the current observation and calculation precision. From the above-motioned results and considering other factors such as computing time, we discuss the selection of sub-network division schemes in TEONET. Source


Gong M.,CAS Institute of Computing Technology | Gong M.,University of Chinese Academy of Sciences | Ge J.,National Quality Inspection and Testing Center for Surveying and Mapping Products | Cao W.,CAS Institute of Computing Technology | And 2 more authors.
Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided Design and Computer Graphics | Year: 2013

Existing methods to quantitatively evaluate the performance of image-based 3D reconstruction are generally based on ground-truth 3D models acquired by 3D scanner, with disadvantages of high cost, low efficiency, and inapplicability to large-scale objects or scenes. To solve this problem, propose an evaluation method based on the invariance of image's phase information. Firstly, get the 2D projection image of the 3D reconstructed model under certain viewpoint. Then, extract edges of this projection image as well as the image of realistic object under the similar viewpoint. Subsequently, compute the proposed phase moment invariants for the two edge images and construct feature vectors. Finally, assess the reconstructed result through comparing the distance between the two feature vectors. Experiments validate the effectiveness and applicability of this method for assessing 3D reconstructed surface model. Source


Han Y.L.,State Nuclear Security Technology Center | Ma W.,National Quality Inspection and Testing Center for Surveying and Mapping Products
Information Technology and Computer Application Engineering - Proceedings of the 2013 International Conference on Information Technology and Computer Application Engineering, ITCAE 2013 | Year: 2014

The research on the forecast of social security incidents covers many subjects such as social science, mathematics and computer science. This paper proposes dividing forecasting and pre-warning of social security incidents into two parts: macroscopic forecast and microscopic forecast, mainly comprehensively reviews the macroscopic forecast method and systemically generalizes several forecast methods such as: Time series analysis; regression analysis and data mining technique, etc. The paper also generalizes the application scope, advantages as well as disadvantages of various methods and indicates the research direction and hot spot of this field by combining the features of various types of social security incidents based on the analysis of the mathematical characteristics of each method. © 2014 Taylor & Francis Group, London. Source


Li X.,Wuhan University | Chen X.,Wuhan University | Chen X.,Jiangxi Normal University | Zhao Y.,National Quality Inspection and Testing Center for Surveying and Mapping Products | And 3 more authors.
Remote Sensing Letters | Year: 2013

In remote-sensing community, radiometric calibration of night-time light images has long been a problem, hindering change detection of images in different dates. Currently, an intercalibration model is regarded as the unique solution for the problem, but prior knowledge is needed to extract reference pixels with stable lights, which are hard to obtain in most of the applications. This study proposed an automatic algorithm to extract the reference pixels for convenient use of the intercalibration model, with an assumption that there are sufficient pixels with stable night-time lights in the multi-temporal images. To automatically extract the stable pixels from images in two dates, all pixels in the two dates were entered into a linear regression model, and the outliers viewed as suspected changed pixels were discarded iteratively. Consequently, some stable pixels were extracted and the intercalibration model was implemented. Annual night-time light composites in Beijing, China, from 1992 to 2010 were taken as the study material, and the results show that the multi-temporal calibrated night-time light data have higher correlation with gross domestic production (GDP) (R2 = 0.8734) and urban population (UP) (R2 = 0.9269) than those of the uncalibrated images (with the R2 values 0.7963 and 0.8575, respectively). Furthermore, the data inconsistency from different night-time light satellites in the same year was reduced with the proposed algorithm. The results demonstrate that the proposed algorithm is effective in intercalibrating the Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) images automatically. © 2012 Taylor & Francis. Source

Discover hidden collaborations