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长江三角洲城市一日游的旅游经济空间联系测度与分析 被引量:44
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作者 曹芳东 吴江 +1 位作者 徐敏 薛献伟 《人文地理》 CSSCI 北大核心 2010年第4期109-114,共6页
本文通过计算长江三角洲中心城市的中心职能强度,对长三角中心城市进行等级划分,在此基础上,借助修正后的旅游经济联系强度、旅游经济隶属度及旅游吸引范围模型,测度城市间旅游经济的联系强度、隶属度及城市旅游控制范围,同时建立城市... 本文通过计算长江三角洲中心城市的中心职能强度,对长三角中心城市进行等级划分,在此基础上,借助修正后的旅游经济联系强度、旅游经济隶属度及旅游吸引范围模型,测度城市间旅游经济的联系强度、隶属度及城市旅游控制范围,同时建立城市旅游经济联系的空间模型并分析长三角中心城市旅游经济联系的方向以及旅游系统空间结构等级层次性特征。结果表明:长三角中心城市旅游经济联系度不断增强,并逐渐向区域旅游经济一体化方向进展,同时区域内部城市旅游经济差异显著,且表现为随着旅游城市等级规模的变化呈现出正相关的旅游经济随之匹配,并在旅游经济的空间联系上按照一定的轴线发生关系,这种轴线在地理空间上表现为"沿线"并且这种联系的规律性在空间上总的方向表现为随城市距离增加而逐级递减规律。基于以上分析,最后针对城市间的旅游经济空间联系对长三角旅游系统空间结构影响加以论述,以此为提升长三角城市一日游的旅游经济活动效率,加快实现长三角旅游经济一体化进程,提供一定理论与现实的依据参考。 展开更多
关键词 GIS 中心城市 旅游经济联系 旅游系 统空间结构 测度分析 长江三角洲
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METHODS OF IMPROVING COMPUTATIONAL ACCURACY OF ROBOT DYNAMICS
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作者 王树新 刘又午 董怡 《Transactions of Tianjin University》 EI CAS 1997年第2期77-81,共5页
In this paper the geometric meaning of robot systems is expounded based on the theory of multibody system. The error accumulation for the known algorithm is analyzed and the cause of ‘Energy consumption’ is revealed... In this paper the geometric meaning of robot systems is expounded based on the theory of multibody system. The error accumulation for the known algorithm is analyzed and the cause of ‘Energy consumption’ is revealed, the relationship between the coefficients of dynamic equation is derived so as to establish the canonical equations. The error accumulation of dynamics can be eliminated by using canonical equations and the symplectic integral method so that the computational accuracy can be ensured effectively. As an example, a planar robotics system is considered. 展开更多
关键词 robot system configuration space symplectic geometry
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ANALYSIS ON SPATIAL FEATURES OF LUCC BASED ON REMOTE SENSING AND GIS IN CHINA 被引量:5
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作者 GAOZhi-qiang DENGXiang-zheng 《Chinese Geographical Science》 SCIE CSCD 2002年第2期107-113,共7页
In view of the large quantities of areas, complex landform and dynamic change of resources and environment in China, China has already funded abundantly a series of macro remote sensing investigation projects in land ... In view of the large quantities of areas, complex landform and dynamic change of resources and environment in China, China has already funded abundantly a series of macro remote sensing investigation projects in land use/ cover change(LUCC) since 1990. Supported by the achievements of such projects, Chinese resources, environmental and remote sensing database (CRERS) was created. In this paper, we standardized the LUCC dataset of CRERS at scale of 1km, which facilitated the study of spatial features of LUCC in China. The analysis on the spatial features of LUCC and their causes of formation in China are based on the CRERS supported by the technologies of Geographic Information System (GIS). The whole research was based on the grade index of land use, ecological environmental index and index of population density. Based on the correlation analysis, we found that the special features of LUCC were closely related with those of ecological environment and population density, which resulted from that areas with better ecological environment and high production potential of land were easy and convenient for human being to live, which, furthermore, led to the aggravation of excessive exploitation of land resources there. 展开更多
关键词 LUCC 1km data grade index remote sensing
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Temporal Data Mining Using Genetic Algorithm and Neural Network——A Case Study of Air Pollutant Forecasts 被引量:1
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作者 Shine-Wei Lin Chih-Hong Sun Chin-Han Chen 《Geo-Spatial Information Science》 2004年第1期31-38,共8页
This paper integrates genetic algorithm and neura l network techniques to build new temporal predicting analysis tools for geographic information system (GIS). These new GIS tools can be readily applied in a practical... This paper integrates genetic algorithm and neura l network techniques to build new temporal predicting analysis tools for geographic information system (GIS). These new GIS tools can be readily applied in a practical and appropriate manner in spatial and temp oral research to patch the gaps in GIS data mining and knowledge discovery functions. The specific achievement here is the integration of related artificial intellig ent technologies into GIS software to establish a conceptual spatial and temporal analysis framework. And, by using this framework to develop an artificial intelligent spatial and tempor al information analyst (ASIA) system which then is fully utilized in the existin g GIS package. This study of air pollutants forecasting provides a geographical practical case to prove the rationalization and justness of the conceptual tempo ral analysis framework. 展开更多
关键词 GIS TEMPORAL data mining genetic algorithm neural network
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Homoclinic (Heteroclinic) Orbit of Complex Dynamical System and Spiral Structure 被引量:1
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作者 FUZun-Tao LIUShi-Da LIUShi-Kuo LIANGFu-Ming XINGuo-Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4期601-603,共3页
Starting from iterated systems, it is shown that the homoclinic (heteroclinic) orbit is a kind of spiral structure. The emphasis is laid to show that there are homoclinic or heteroclinic orbits in complex discrete and... Starting from iterated systems, it is shown that the homoclinic (heteroclinic) orbit is a kind of spiral structure. The emphasis is laid to show that there are homoclinic or heteroclinic orbits in complex discrete and continuous systems, and these homoclinic or heteroclinic orbits are some kind of spiral structure. 展开更多
关键词 complex system homoclinic (heteroclinic) orbit spiral structure
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Spatial Analysis of Commuting Mode Choice in Guangzhou, China 被引量:4
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作者 ZHOU Suhong DENG Lifang HUANG Meiyu 《Chinese Geographical Science》 SCIE CSCD 2013年第3期353-364,共12页
Metropolitan cities in China are commonly confronted with unresolved traffic congestion issues, primarily due to rapidly increasing traffic demand. Group disparity between commuting mode choice and its spatial distrib... Metropolitan cities in China are commonly confronted with unresolved traffic congestion issues, primarily due to rapidly increasing traffic demand. Group disparity between commuting mode choice and its spatial distribution on road networks has enabled us to examine the factors that give rise to the discrepancies and the fundamental spatial causes of traffic congestion. In recent years, mi- cro-perspective, individual, and behavior-based spatial analysis have mushroomed and been facilitated with effective tools such as tem- poral geographic information systems (T-GIS). It is difficult to study the interrelations between transport and space on the basis of commuting mode choice since the mode choice data are invisible in a specific space such as a particular road network. Therefore, in the field of transport, the classical origin destination (OD) four-stage model (FSM) is usually employed to calculate data when studying commuting mode choice. Based on the relative principles of T-GIS and the platform of ArcGIS, this paper considers Guangzhou as a case study and develops a spatio-temporal tool to examine the daily activities of residents. Meanwhile, the traffic volume distribution in rush hours, which was analyzed according to commuting modes and how they were reflected in the road network, was scrutinized with data extracted from travel diaries. Moreover, efforts were made to explain the relationship between traffic demand and urban spatial structure. Based on the investigation, this research indicates that traffic volumes in divergent groups and on the road networks is driven by: l) the socio-economie characteristics of travelers; 2) a jobs-housing imbalance under suburbanization; 3) differences in the spatial supply of transport modes; 4) the remains of the Danwei (work unit) system and market development in China; and 5) the transition of urban spatial structure and other factors. 展开更多
关键词 TRANSPORT travel mode China temporal geographic information systems (T-GIS)
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Spatial-temporal Characteristics of Land Use Intensity of Coastal Zone in China During 2000–2010 被引量:24
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作者 DI Xianghong HOU Xiyong +1 位作者 WANG Yuandong WU Li 《Chinese Geographical Science》 SCIE CSCD 2015年第1期51-61,共11页
Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China′s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity co... Based on remote sensing and GIS techniques, land use maps in 2000, 2005 and 2010 in China′s coastal zone were produced, and structural raster data of land use were further generated to calculate land use intensity comprehensive index(LUICI) for analyzing land use spatial-temporal characteristics at 1 km scale. Results show that: 1) from the perspective of spatial patterns of landforms at a macro scale, there is a significant difference in land use intensity between the north and the south of China′s coastal zone. Hotspots of changes mainly concentrated in metropolitan areas, estuaries and coastal wetlands; 2) elevation is an important factor that controlling land use spatial patterns at local scale. Land use intensity is much higher within areas below the elevation of 400 m and it decreased significantly as the elevation increasing; 3) there is a significant land-ocean gradient for land use intensity, which is low in island and near-shore areas, but high in the regions that 4–30 km far away the coastline because of much intensive human activities; however, in recent decades land use intensity had been promoted significantly in low near-shore area due to extensive sea reclamations; 4) significant differences of land use intensity were also found among provincial administrative units. A rising trend of land use intensity was found in provincial-level administrative units from 2000 to 2010. To sum up, elevation, land-ocean gradient, socio-economic status and policy are all influencing factors to the spatial patterns and temporal variations of land use intensity in China′s coastal zone. 展开更多
关键词 coastal zone land use intensity land use intensity comprehensive index(LUICI) spatial pattern ELEVATION land-ocean gradient
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Shed Light on the Geometrical Configuration and Structural Principle of an Ancient Wooden Bridge in Qingming Shanghe Tu
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作者 Pei-Shan Chen 《Journal of Civil Engineering and Architecture》 2012年第6期665-672,共8页
In the centre of the famous Chinese painting, Qingrning Shanghe Tu, an arch-shaped timber bridge, Hongqiao, stands like a rainbow over the river Bianhe. Unfortunately, Hongqiao was damaged during floods from the Yello... In the centre of the famous Chinese painting, Qingrning Shanghe Tu, an arch-shaped timber bridge, Hongqiao, stands like a rainbow over the river Bianhe. Unfortunately, Hongqiao was damaged during floods from the Yellow River, and we can only see her beautiful form in Qingming Shanghe Tu. While, the geometrical dimensions, structural principle, as well as the construction methods of the bridge are still an interesting mystery. In the present paper, the author uncovers the structural principle and the geometric dimensions of the bridge as well as its history background. Furthermore, the author introduces two new structural systems, Lap-Beam and 1.5-Layer space frame, which are inspired by the structural principle of the Hongqiao. 展开更多
关键词 Lap-beam 1.5-layer space frame arch bridge Hongqiao Qingming Shanghe Tu wooden bridge.
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Stabilization of Hyperbolic Chaos by the Pyragas Method
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作者 Sergey Belyakin Arsen Dzanoev Sergey Kuznetsov 《Journal of Mathematics and System Science》 2014年第12期755-762,共8页
For a long time it was a common opinion that hyperbolic attractors are artificial mathematical constructions. However, in the recent papers there were proposed physically realizable systems that possess, in their phas... For a long time it was a common opinion that hyperbolic attractors are artificial mathematical constructions. However, in the recent papers there were proposed physically realizable systems that possess, in their phase space, the set with features that are very similar to hyperbolic type of attractors. As is known, invariant sets are called hyperbolic attractors of the dynamical system if they are closed, topologically transitive subsets, and every their trajectory possesses uniform hyperbolicity. Very familiar types of the hyperbolic attractors are Smale-Williams' solenoid and Plykin's attractor. Further, it is well known that chaotic systems are very sensitive to the external perturbations. This property is used for controlling nonlinear systems and chaos suppression. Thus, an important question arises: Is it possible to suppress chaos in systems with hyperbolic attractors because these attractors are structurally stable subsets? In the present contribution we study the possibility of stabilization of chaotic oscillations in systems with the Smale-Williams hyperbolic attractors by means of the Pyragas method with a delay. It is shown that by means of external perturbation the dynamical system could be controllable: the hyperbolic attractor degenerates into a periodic one. 展开更多
关键词 Dynamical system hyperbolic attractors Pyragas method
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Exotic Structures of Odd-A Carbon Isotopes in the Deformed Relativistic Mean-FieldTheory
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作者 JIANGWei-Zhou RENZhong-Zhou +2 位作者 ZHUZhi-Yuan WANGTing-Tai HEZe-Jun 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第1期79-88,共10页
We study contributions of the pion meson and spatial component of the omega meson in the odd-A carbon isotopes. The pion and spatial omega provide small attractions in odd-A nuclei, giving rise to considerable influen... We study contributions of the pion meson and spatial component of the omega meson in the odd-A carbon isotopes. The pion and spatial omega provide small attractions in odd-A nuclei, giving rise to considerable influences on the single-particle energies rather than the bulk properties such as total binding energies, and root-mean-square (rms) radii. The ±? (spin) splittings, arising from the spatial omega, are large in <SUP>11</SUP>C and <SUP>13</SUP>C and drop as the isospin rises in odd-A carbon isotopes. As an isovector, the pion can shift slightly the relative potential depth of neutron and proton, contrary to the role of the rho meson. There is a general trend that both the pion and spatial omega fields reduce with the rise of isospin in the isotopic chain. From the normal nucleus to halo nucleus, an abnormal drop of the pion or spatial omega field may occur, as can be seen in <SUP>19</SUP>C, <SUP>15</SUP>C, and <SUP>21</SUP>C. 展开更多
关键词 halo nuclei relativistic mean-field theory
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Khedivial Cairo: An Evolved Metabolism
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作者 Eman Mamdouh Abdel Sabour Stephen Luoni 《Journal of Civil Engineering and Architecture》 2013年第5期616-625,共10页
Metabolism such as Cairo evolves rabidly, to transform existing urban spaces. The result of transformation process may lead to the loss of the original space qualities. Opera and Ataba squares are junction space which... Metabolism such as Cairo evolves rabidly, to transform existing urban spaces. The result of transformation process may lead to the loss of the original space qualities. Opera and Ataba squares are junction space which is one of these urban spaces that meanwhile is suffering from this process. This junction space is between two unique urban structures Fatima Cairo and Down town Cairo. This urban structure needs to be a grand civic expression of the 19th century urban system with the new energies of the functionalist city. This Gordian knot of elevated highways, congested surface roads, extensive automobile parking and sprawling informal markets will be integrated into a new open space system that optimizes the city's intensified energies. This paper discusses urban structure transformation of the junction space urban structure timeline. Ending with a proposal finally transforms this space into a sustainable urban development. 展开更多
关键词 Urban spaces Khedivial Cairo sustainable urban development district transformation.
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Evolutionary model of the central place hierarchical system 被引量:1
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作者 LU YuQi YUAN LinWang ZHONG YeXi 《Science China Earth Sciences》 SCIE EI CAS 2011年第10期1614-1626,共13页
Central place theory is one of the two theoretical cornerstones of geography, yet it cannot be connected with other spatial structure models, fails to provide definite time-space parameter conditions, lacks an evoluti... Central place theory is one of the two theoretical cornerstones of geography, yet it cannot be connected with other spatial structure models, fails to provide definite time-space parameter conditions, lacks an evolutionary process model, and does not easily enable construction of a complete theoretical system of regional spatial structure. This paper gives an in-depth analysis of the process and mechanism for production and evolution of central places of different grades, and constructs an evolutionary model of the central place hierarchical system. The results of deduction, analysis and simulation show that production and evolution of the central place hierarchical system may be divided into five stages. These stages are the embryonic, formative, improvement, maturation, and advancement stages. Affected by spatial location and centricity, central places have obvious differences in scale and functional structures. There are great differences in the scale of same-grade central places. However, low-grade central places could have larger scales than high-grade central places, and the central places of a central location may form the agglomeration area of central places. Based on the hypothesis condition of an isotropic plain, the research shows that it is possible not only to form proportional functional structures of central places, but also to produce non-proportional scale structures of central places, and thus to complete the transformation from rationalistic deduction of spatial equilibrium mode to an explanation and demonstration of an unbalanced practical model. 展开更多
关键词 central place theory hierarchical system evolutionary model functional structure scale structure
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Application of Ordinary Kriging in Mapping Soil Organic Carbon in Zambia 被引量:7
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作者 Lydia Mumbi CHABALA Augustine MULOLWA Obed LUNGU 《Pedosphere》 SCIE CAS CSCD 2017年第2期338-343,共6页
The quantification of the pattern and spatial distribution of soil organic carbon (SOC) is fundamental to understand many ecosystem processes. This study aimed to apply ordinary kriging (OK) to model the spatial d... The quantification of the pattern and spatial distribution of soil organic carbon (SOC) is fundamental to understand many ecosystem processes. This study aimed to apply ordinary kriging (OK) to model the spatial distribution of SOC in a selected part of Zambia. A total of 100 soil samples were collected from the study area and analyzed for SOC by determining soil oxidizable carbon using the Walkley-Black method. An automated fitting procedure was followed when modeling the spatial structure of the SOC data with the exponential semivariogram. The results indicated that the short range spatial dependence of SOC was strong with a nugget close to zero. The spatial autocorrelation was high to medium with a nugget to sill ratio of 0.25. The root mean square error of the predictions was 0.64, which represented 58.18% of the mean observed data for SOC. It can be concluded that the generated map could serve as a proxy for SOC in the region where evidence of spatial structure and quantitative estimates of uncertainty are reported. Therefore, the maps produced can be used as guides for various uses including optimization of soil sarapling. 展开更多
关键词 exponential semivariogram geographical distribution geostatistical procedure oxidizable carbon spatial autocorrela-tion
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Statistical Structures on Metric Path Spaces
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作者 Mircea CRASMAREANU Cristina-Elena HRET CANU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2012年第6期889-902,共14页
The authors extend the notion of statistical structure from Riemannian geometry to the general framework of path spaces endowed with a nonlinear connection and a generalized metric.Two particular cases of statistical ... The authors extend the notion of statistical structure from Riemannian geometry to the general framework of path spaces endowed with a nonlinear connection and a generalized metric.Two particular cases of statistical data are defined.The existence and uniqueness of a nonlinear connection corresponding to these classes is proved.Two Koszul tensors are introduced in accordance with the Riemannian approach.As applications,the authors treat the Finslerian (α,β)-metrics and the Beil metrics used in relativity and field theories while the support Riemannian metric is the Fisher-Rao metric of a statistical model. 展开更多
关键词 Semispray Nonlinear connection Metric path space Statistical struc-ture SKEWNESS Koszul tensors (~ ~)-metric Beil metric Rayleigh sta-tistical structure Fisher-Rao metric Statistical model
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Structural topology optimization: Extensibility and attainability 被引量:6
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作者 ZHANG WeiHong ZHANG ZhiDong +1 位作者 ZHU JiHong GAO Tong 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第7期1310-1321,共12页
Extensibility and attainability of topology optimization are discussed by investigating a variety of simultaneous topology opti-mization methods extended from the standard formulation.First,the state of the art is hig... Extensibility and attainability of topology optimization are discussed by investigating a variety of simultaneous topology opti-mization methods extended from the standard formulation.First,the state of the art is highlighted through systematic classification of developed methods,such as simultaneous topology optimizations of microstructure and macrostructure,structure and supports,structure and design-dependent loads,structure and locations of involved components.Second,some recent results about simultaneous topology optimization of structure and applied loads are presented.It is shown that the simultaneous topology optimization is an integrated methodology that extends the concept of standard topology optimization in the sense of systematic design.The presence of more than one kind of design variable of different nature makes the optimization problem complex but enlarges the design space to attain the optimization. 展开更多
关键词 topology optimization simultaneous optimization MULTI-COMPONENT SUPPORT design-dependent load load location
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Fluctuation limits of strongly degenerate branching systems
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作者 LI YuQiang 《Science China Mathematics》 SCIE 2011年第12期2669-2682,共14页
Functional limit theorems for scaled occupation time fluctuations of a sequence of generalized branching particle systems in Rd with anisotropic space motions and strongly degenerated splitting abilities are studied i... Functional limit theorems for scaled occupation time fluctuations of a sequence of generalized branching particle systems in Rd with anisotropic space motions and strongly degenerated splitting abilities are studied in the cases of critical and intermediate dimensions. The results show that the limit processes are time-independent measure-valued Wiener processes with simple spatial structure. 展开更多
关键词 functional limit theorem occupation time fluctuation branching particle system
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Influence of Organic Matter Content on Hydro-Structural Properties of Constructed Technosols 被引量:1
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作者 Maha DEEB Michel GRIMALDI +3 位作者 Thomas Z.LERCH Anne PANDO Pascal PODWOJEWSKI Manuel BLOUIN 《Pedosphere》 SCIE CAS CSCD 2016年第4期486-498,共13页
Constructed Technosols may be an alternative for creating urban green spaces. However, the hydro-structural properties emer- ging from the assembly of artefacts have never been documented. The soil shrinkage curve (... Constructed Technosols may be an alternative for creating urban green spaces. However, the hydro-structural properties emer- ging from the assembly of artefacts have never been documented. The soil shrinkage curve (SSC) could provide relevant structural information about constructed Technosols, such as the water holding capacity of each pore system (macropores and micropores). The objectives of this study were (i) to evaluate the SSC and water retention curve (WRC) to describe the structure of constructed Tech- nosols and (ii) to understand the influence of organic matter content on soil hydro-structural properties. In this study, Technosols were obtained by mixing green waste compost (GWC) with the material excavated from deep horizons of soil (EDH). The CWC was mixed with EDH in six different volumetric percentages from 0% to 50% (GWC/total). The GWC and EDH exhibited highly divergent hydro-structural properties: the SSC was hyperbolic for GWC and sigmoid for EDH. All six mixture treatments (0%, 10%, 20%, 30%, 40% and 50% GWC) exhibited the classical sigmoid shape, revealing two embedded levels of pore systems. The 20% GWC treatment was hydro-structurally similar to the 30% and 40% GWC treatments; so, a large quantity of expansive GWC is unnecessary. The relation with the GWC percentage was a second-degree equation for volumetric available water in micropores, but was linear for volumetric available water in macropores and total volumetric available water. Total volumetric available water in the 50% GWC treatment was twice as high as that in the 0% GWC treatment. By combining SSCs and WRCs, increasing the GWC percentage increased water holding capacity by decreasing the maximum equivalent size of water-saturated micropores at the shrinkage limit and increasing the maximum equivalent size of water-saturated macropores, resulting in an increased range of pore diameter able to retain available water. 展开更多
关键词 available water soil shrinkage curve soil water content water holding capacity water retention curve
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Design of Service-Oriented Architecture for Spatial Data Integration and Its Application in Building Web-based GIS Systems 被引量:4
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作者 SHA Zongyao XIE Yichun 《Geo-Spatial Information Science》 2010年第1期8-15,共8页
In this paper we propose a service-oriented architecture for spatial data integration (SOA-SDI) in the context of a large number of available spatial data sources that are physically sitting at different places, and d... In this paper we propose a service-oriented architecture for spatial data integration (SOA-SDI) in the context of a large number of available spatial data sources that are physically sitting at different places, and develop web-based GIS systems based on SOA-SDI, allowing client applications to pull in, analyze and present spatial data from those available spatial data sources. The proposed architecture logically includes 4 layers or components; they are layer of multiple data provider services, layer of data in-tegration, layer of backend services, and front-end graphical user interface (GUI) for spatial data presentation. On the basis of the 4-layered SOA-SDI framework, WebGIS applications can be quickly deployed, which proves that SOA-SDI has the potential to reduce the input of software development and shorten the development period. 展开更多
关键词 spatial data integration web-based GIS service-oriented architecture software
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