共查询到20条相似文献，搜索用时 156 毫秒
1.
WANGShugen 《地球空间信息科学学报》2002,5(2):74-78
According to the fundamental theory of visual cognition mechanism and cognitive psychology,the visual pattern recognition model is introduced briefly.Three pattern recognition models,i.e.template-based matching model,prototype-based matching model and feature-based matching model are built and discussed separately.In addition,the influence of object background information and visual focus point to the result of pattern recognition is also discussed with the example of recognition for fuzzy letters and figures. 相似文献
2.
Using degree distribution to assess network vulnerability represents a promising direction of network analysis.However,the traditional degree distribution model is inadequate for analyzing the vulnerability of spatial networks because it does not take into consideration the geographical aspects of spatial networks.This paper proposes a spatially weighted degree model in which both the functional class and the length of network links are considered to be important factors for determining the node degrees of spatial networks.A weight coefficient is used in this new model to account for the contribution of each factor to the node degree.The proposed model is compared with the traditional degree model and an accessibility-based vulnerability model in the vulnerabil-ity analysis of a highway network.Experiment results indicate that,although node degrees of spatial networks derived from the tra-ditional degree model follow a random distribution,node degrees determined by the spatially weighted model exhibit a scale-free distribution,which is a common characteristic of robust networks.Compared to the accessibility-based model,the proposed model has similar performance in identifying critical nodes but with higher computational efficiency and better ability to reveal the overall vulnerability of a spatial network. 相似文献
3.
In this paper,the structure of systematic and random errors in marine survey net are discussed in detail and the adjustment method for observations of marine survey net is studied,in which the rank-defect haracteristic is discovered first up to now.On the basis of the survey-line systematic error model,the formulae of the rank-defect adjustment model are deduced according to modern adjustment theory.An examle of calculations with really observed data is carried out to demonstrate the efficiency of this adjustment model.Moreover,it is proved that the semi-systematic error correction method used at present in marine gravimetry in China is a special case of the adjustment model presented in this paper. 相似文献
4.
LIUChun SHIWenzhong LIUDajie 《地球空间信息科学学报》2003,6(2):13-19
On the basis of the principles of simple random sampling,the statistical model of rate of disfigure-ment(RD)is put forward and described in detail.According to the definition of simple random sampling for the attribute data in GIS,the mean and variance of the RD are deduced as the characteristic value of the statistical model in order to explain the feasibility of the accuracy measurement of the attribute data in GIS by using the RD.Moreover,on the basis of the mean and variance of the RD,the quality assessment method for attribute data of vector maps during the data collecting is discussed.The RD spread graph is also drawn to see whether the quality of the attribute data is under control.The RD model can synthetically judge the quality of attribute data,which is different from other measurement coefficients that only discuss accuracy of classification. 相似文献
5.
A distributed hypermap model for internet gis 总被引：4，自引：0，他引：4
The rapid development of Internet technology makes it possible to integrate GIS with the Internet,forming Internet GIS.Internet GIS is based on a distributed client/server architecture and TCP/IP & IIOP.When constructing and designing Internet GIS,we face the problem of how to express information units of Internet GIS.In order to solve this problem,this paper presents a distributed hypermap model for Internet GIS.This model provides a solution to organize and manage Internet GIS information units.It also illustrates relations between two information units and in an internal information unit both on clients and servers.On the basis of this model,the paper contributes to the expressions of hypermap relations and hypermap operations.The usage of this model is shown in the implementation of a prototype system. 相似文献
6.
7.
The optimization of land-use spatio-structure is one of the most important areas of land use management;constructing a spatial optimization model that is based on the micro spatial unit in a bottom-up mode plays an important role in coupling the quan-tity structure and spatial structure effectively.The objective of this research is to develop a land use spatial optimization model based on particle swarm optimization to make spatial decision in land use management.The model is implemented using real data-sets to emulate the process of spatial structure optimization in order to get the best landscape pattern under the control of decision environments.Simulation results revealed that the particle swarm optimization model has the ability to utilize the quantity and spa-tial structure.Furthermore,the result demonstrated that it can be used to stimulate the landscape pattern in designing the appropriate optimization environment,which could land quantity target to the basic spatial units effectively and provide appropriate spa-tio-structure for regional land use space layout decision making. 相似文献
8.
JIAO Limin LIU Yaolin 《地球空间信息科学学报》2007,10(2):151-156
A novel model of land suitability evaluation is built based on computational intelligence (CI). A fuzzy neural network (FNN) is constructed by the integration of fuzzy logic and artificial neural network (ANN). The structure and process of this network is clear. Fuzzy rules (knowledge) are expressed in the model explicitly, and can be self-adjusted by learning from samples. Genetic algorithm (GA) is employed as the learning algorithm to train the network, and makes the training of the model efficient. This model is a self-learning and self-adaptive system with a rule set revised by training. 相似文献
9.
YU Xuexiang associate professor Ph.D Department of Resource Environment Engineering Anhui University of Science Technology Huainan China. XU Shaoquan GAO Wei LU Weicai 《地球空间信息科学学报》2003,6(4):51-56
A new similar singledifference mathematical model ( SS-DM) and its corresponding algorithm are advanced to solve the deformation of monitoring point directly in single epoch. The method for building the SSDM is introduced in detail, and the main error sources affecting the accuracy of deformation measurement are analyzed briefly, and the basic algorithm and steps of solving the deformation are discussed. In order to validate the correctness and the accuracy of the similar single-difference model, the test with five dual frequency receivers is carried out on a slideway which moved in plane in Feb. 2001. In the test, five sessions are observed. The numerical results of test data show that the advanced model is correct. 相似文献
10.
YU Bo LIU Yanchun ZHAI Guojun BIAN Gang XIAO Fumin 《地球空间信息科学学报》2007,10(3):186-190
The detection and identification of the seabed cable is becoming an important task in the marine engineering. The features of the magnetic anomaly can be used to detect the existence of the seabed cable. The magnetic field model is presented, and the consistency of the magnetic anomaly distribution between the simulation of the model and the observed data is verified. The comparison shows that the seabed cable can be effectively detected and identified with reasonable method. 相似文献
11.
一种面向网络发布的海洋遥感数据库引擎 总被引：1，自引：0，他引：1
针对海洋遥感数据的有效管理和网络发布需求，设计了面向海洋遥感数据的空间数据库引擎MRSS-DE。介绍了MRSSDE的数据逻辑结构模型、物理存储模型和性能优化方法，通过与主流数据库引擎ArcSDE的对比测试，证明了该引擎对海洋遥感数据具有存储效率高、数据上载速度及响应时间快等特点。 相似文献
12.
To meet the requirements of efficient management and web publishing for marine remote sensing data, a spatial database engine, named MRSSDE, is designed independently. The logical model, physical model, and optimization method of MRSSDE are discussed in detail. Compared to the ArcSDE, which is the leading product of Spatial Database Engine, the MRSSDE proved to be more effective. 相似文献
13.
基于簇模型的矢量地图数据的高效压缩方法(英文) 总被引：3，自引：2，他引：1
This paper proposes a new method for the compression of vector data map. Three key steps are encompassed in the proposed method,
namely, the simplification of vector data map via the elimination of vertices, the compression of removed vertices based on
a clustering model, and the decoding of the compressed vector data map. The proposed compression method was implemented and
applied to compress vector data map to investigate its performance in terms of the compression ratio and distortions of geometric
shapes. The results show that the proposed method provides a feasible and efficient solution for the compression of vector
data map and is able to achieve a promising ratio of compression and maintain the main shape characteristics of the spatial
objects within the compressed vector data map.
Supported by the National 863 Program of China (No. 2007AAl2Z241), the Program for New Century Excellent Talents in University
(No. NCET-07-0643), the National Natural Science Foundation of China (No. 40571134, No. 40871185), the National 973 Program
of China (No. 108085). 相似文献
14.
Reducing Influence of Gravity Model Error in Precise Orbit Determination of Low Earth Orbit Satellites 总被引：1，自引：0，他引：1
GUO Jinlai HU Min ZHAO Qile GUO Daoyu 《地球空间信息科学学报》2007,10(2):105-110
Based on the orbit integration and orbit fitting method, the influence of the characters of the gravity model, with different precisions, on the movement of low Earth orbit satellites was studied. The way and the effect of absorbing the influence of gravity model error on CHAMP and GRACE satellite orbits, using linear and periodical empirical acceleration models and the so-called "pseudo-stochastic pulses" model, were also analyzed. 相似文献
15.
LUO Jia LI Jiancheng CHAO Dingbo 《地球空间信息科学学报》2003,6(1):19-23
1 ＩｎｔｒｏｄｕｃｔｉｏｎＴｏｄｅｖｅｌｏｐｔｈｅｏｃｅａｎｗｉｄｅｌｙａｎｄｄｅｅｐｌｙ ,ｗｅｎｅｅｄａｂｕｎｄａｎｔｏｃｅａｎｉｎｆｏｒｍａｔｉｏｎ .Ａｓａｎｅｓｓｅｎｔｉａｌｐａｒｔｏｆｓｕｃｈｉｎｆｏｒｍａｔｉｏｎ ,ｓｅａｆｌｏｏｒｔｏｐｏｇｒａｐｈｙｐｌａｙｓａｖｅｒｙｉｍｐｏｒｔａｎｔｒｏｌｅｉｎａｖａｒｉｅｔｙｏｆｍａｒｉｎｅａｃｔｉｖｉｔｉｅｓ .Ｈｏｗｅｖｅｒ,ｔｈｅｈｉｇｈｃｏｓｔｆｏｒｏｃｅａｎｂａｔｈｙｍｅｔｒｉｃｓｕｒｖｅｙｉｎｇｌｉｍｉｔｓｔｈｅａｐｐｌｉｃａｔｉｏｎｏ… 相似文献
16.
The advanced data mining technologies and the large quantities of remotely sensed Imagery provide a data mining opportunity
with high potential for useful results. Extracting interesting patterns and rules from data sets composed of images and associated
ground data can be of importance in object identification, community planning, resource discovery and other areas. In this
paper, a data field is presented to express the observed spatial objects and conduct behavior mining on them. First, most
of the important aspects are discussed on behavior mining and its implications for the future of data mining. Furthermore,
an ideal framework of the behavior mining system is proposed in the network environment. Second, the model of behavior mining
is given on the observed spatial objects, including the objects described by the first feature data field and the main feature
data field by means of the potential function. Finally, a case study about object identification in public is given and analyzed.
The experimental results show that the new model is feasible in behavior mining.
Supported by the National 973 Program of China(No.2006CB701305,No.2007CB310804), the National Natural Science Fundation of
China (No.60743001), the Best National Thesis Fundation (No.2005047), the National New Century Excellent Talent Fundation
(No.NCET-06-0618). 相似文献
17.
ZOU Xiancai LI Jiancheng LUO Jia XU Xinyu 《地球空间信息科学学报》2007,10(4):255-259
The characteristics of the normal equation created in recovering the Earth gravity model (EGM) by least-squares(LS) adjustment from the in-situ disturbing potential is discussed in detail. It can be co... 相似文献
18.
数字城市共享平台框架的设计与实现(英文) 总被引：2，自引：1，他引：1
This paper proposes a theoretical framework of spatial information sharing in a digital city, and analyzes its technical characteristics.
According to the service-oriented architecture (SOA) framework, a geospatial information sharing platform is put forward.
The spatial information sharing model based on SOA is designed. A prototype platform realizing multiple-source spatial information
sharing based on ArcGIS Server is developed.
Supported by the National Key Basic Research and Development Program of China (No.2004CB318206), the Basic Research of Survey
and Mapping Bureau Project (No.1469990711111). 相似文献
19.
ZHANG Jianqing ZHANG Zuxun 《地球空间信息科学学报》2003,6(1):49-53
This paper calculates the parameters of image position and orientation,proposes a mathematical model and adopts a mew method with three steps of transformations based on parallel ray projection.Every step of the model is strict,and the map function of each transformation is the first order polynomials and other simple function.The final calculation of the parameters is for the linear equation with good status.As a result,the problem of the relativity of image parameter calculation is solved completely.Some experiments are carried out. 相似文献
20.
Three functional models, polynomial, spectral analysis, and modified AR model, are studied and compared in fitting and predicting clock deviation based on the data sequence derived from two-way satellite time and frequency transfer. A robust equivalent weight is applied, which controls the significant influence of outlying observations. Some conclusions show that the prediction precision of robust estimation is better than that of LS. The prediction precision calculated from smoothed observations is higher than that calculated from sampling observations. As a count of the obvious period variations in the clock deviation sequence, the predicted values of polynomial model are implausible. The prediction precision of spectral analysis model is very low, but the principal periods can be determined. The prediction RMS of 6-hour extrapolation interval is Ins or so, when modified AR model is used. 相似文献