Geographic information has become central for data scientists of many disciplines to put their analyzes into a spatio-temporal perspective.However,just as the volume and variety of data sources on the Web grow,it beco...Geographic information has become central for data scientists of many disciplines to put their analyzes into a spatio-temporal perspective.However,just as the volume and variety of data sources on the Web grow,it becomes increasingly harder for analysts to be familiar with all the available geospatial tools,including toolboxes in Geographic Information Systems(GIS),R packages,and Python modules.Even though the semantics of the questions answered by these tools can be broadly shared,tools and data sources are still divided by syntax and platform-specific technicalities.It would,therefore,be hugely beneficial for information science if analysts could simply ask questions in generic and familiar terms to obtain the tools and data necessary to answer them.In this article,we systematically investigate the analytic questions that lie behind a range of common GIS tools,and we propose a semantic framework to match analytic questions and tools that are capable of answering them.To support the matching process,we define a tractable subset of SPARQL,the query language of the Semantic Web,and we propose and test an algorithm for computing query containment.We illustrate the identification of tools to answer user questions on a set of common user requests.展开更多
Fault-block structures of the Altay-Sayan folded area (ASFA) southeastern Siberia of Russia were used as the basis for creating a 3-D model. The surface structures were projected to depths by previous correlations b...Fault-block structures of the Altay-Sayan folded area (ASFA) southeastern Siberia of Russia were used as the basis for creating a 3-D model. The surface structures were projected to depths by previous correlations between long and deep faults, with all layers and deformation factors defined. The mean deformation factor (Ds) is 0.12 unit/km^3 in the upper layer, 0.012 unit/km^3 in the intermediate layer, and 0.007 unit/km^3 in the lower layer of the 3-D ASFA neotectonic model. Ds allows correlation of the three distinguished layers with theological bodies that differ in their potential for accumulating elastic energy. 3-D modeling can be used as a methodological approach to projections in seismic prone areas such as the Krasnoyarsk region, for earthquake-hazard monitoring.展开更多
Declining soil fertility has become an increasingly urgent problem and gathering firewood is one of the important contributing factors.Due to the excessive exploitation of natural resources especially for firewood,the...Declining soil fertility has become an increasingly urgent problem and gathering firewood is one of the important contributing factors.Due to the excessive exploitation of natural resources especially for firewood,the red soil hilly region has become one of the most vulnerable eco-environment regions in China.The pressure of gathering firewood on forestland soil fertility in forestland has been generally estimated by geographical information system and questionnaire method in this paper in the Zhuxi watershed of Changting County,Fujian Province,China,a typical representative in the red soil hilly region of China.The results of this study show that:i) Forestland soil fertility is negatively affected by gathering firewood,which is more intensive in the integrated buffer zone than out of zone.The forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and <2μm clay content are lower and bulk density is higher in the integrated buffer zone than those out.ii) The forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and <2μm clay content tend to be lower and bulk density tends to be higher in the village buffer zones than those out in Datian,Chenguang and Youfang respectively.iii) The population density,economic development and terrain might be the key driving forces contributing to the relationship between gathering firewood and forestland soil fertility.Higher population density leads to more massive firewood collection and imposes more pressure on forestland soil fertility.Decreasing the use of firewood stove may reduce firewood consumption and thus release the pressure of gathering firewood on forestland soil fertility.Terrain affects the accessibility to gathering firewood thus affects forestland soil fertility.Other driving forces influencing the relationship between gathering firewood and forestland soil fertility should also be taken into account in the further study.展开更多
In this paper, by introducing a proper transformation, the (Gr/G)-expansion method is further extended into the nonlinear reaction diffusion equations in mathematical biology whose balancing numbers may be negative ...In this paper, by introducing a proper transformation, the (Gr/G)-expansion method is further extended into the nonlinear reaction diffusion equations in mathematical biology whose balancing numbers may be negative integer. As a result, hyperbolic function solutions and trigonometric function solutions with free parameters are obtained. When the parameters are taken as special values the solitary wave solutions and the periodic wave solutions are also derived from the traveling wave solutions. Moreover, it is observed that the suggested techniques is compatible of such problems.展开更多
In this article, we propose an alternative approach of the generalized and improved (G'/G)-expansion method and build some new exact traveling wave solutions of three nonlinear evolution equations, namely the Boiti...In this article, we propose an alternative approach of the generalized and improved (G'/G)-expansion method and build some new exact traveling wave solutions of three nonlinear evolution equations, namely the Boiti- Leon-Pempinelle equation, the Pochhammer-Chree equations and the Painleve integrable Burgers equation with free parameters. When the free parameters receive particular values, solitary wave solutions are constructed from the traveling waves. We use the Jacob/elliptic equation as an auxiliary equation in place of the second order linear equation. It is established that the proposed algorithm offers a further influential mathematical tool for constructing exact solutions of nonlinear evolution equations.展开更多
文摘Geographic information has become central for data scientists of many disciplines to put their analyzes into a spatio-temporal perspective.However,just as the volume and variety of data sources on the Web grow,it becomes increasingly harder for analysts to be familiar with all the available geospatial tools,including toolboxes in Geographic Information Systems(GIS),R packages,and Python modules.Even though the semantics of the questions answered by these tools can be broadly shared,tools and data sources are still divided by syntax and platform-specific technicalities.It would,therefore,be hugely beneficial for information science if analysts could simply ask questions in generic and familiar terms to obtain the tools and data necessary to answer them.In this article,we systematically investigate the analytic questions that lie behind a range of common GIS tools,and we propose a semantic framework to match analytic questions and tools that are capable of answering them.To support the matching process,we define a tractable subset of SPARQL,the query language of the Semantic Web,and we propose and test an algorithm for computing query containment.We illustrate the identification of tools to answer user questions on a set of common user requests.
文摘Fault-block structures of the Altay-Sayan folded area (ASFA) southeastern Siberia of Russia were used as the basis for creating a 3-D model. The surface structures were projected to depths by previous correlations between long and deep faults, with all layers and deformation factors defined. The mean deformation factor (Ds) is 0.12 unit/km^3 in the upper layer, 0.012 unit/km^3 in the intermediate layer, and 0.007 unit/km^3 in the lower layer of the 3-D ASFA neotectonic model. Ds allows correlation of the three distinguished layers with theological bodies that differ in their potential for accumulating elastic energy. 3-D modeling can be used as a methodological approach to projections in seismic prone areas such as the Krasnoyarsk region, for earthquake-hazard monitoring.
基金funded by the National Natural Science Foundation of China (Grant Nos.40871141,41001170,41171232)
文摘Declining soil fertility has become an increasingly urgent problem and gathering firewood is one of the important contributing factors.Due to the excessive exploitation of natural resources especially for firewood,the red soil hilly region has become one of the most vulnerable eco-environment regions in China.The pressure of gathering firewood on forestland soil fertility in forestland has been generally estimated by geographical information system and questionnaire method in this paper in the Zhuxi watershed of Changting County,Fujian Province,China,a typical representative in the red soil hilly region of China.The results of this study show that:i) Forestland soil fertility is negatively affected by gathering firewood,which is more intensive in the integrated buffer zone than out of zone.The forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and <2μm clay content are lower and bulk density is higher in the integrated buffer zone than those out.ii) The forestland soil fertility grade,OM,total N,available N,total P,available P,total K,available K,pH and <2μm clay content tend to be lower and bulk density tends to be higher in the village buffer zones than those out in Datian,Chenguang and Youfang respectively.iii) The population density,economic development and terrain might be the key driving forces contributing to the relationship between gathering firewood and forestland soil fertility.Higher population density leads to more massive firewood collection and imposes more pressure on forestland soil fertility.Decreasing the use of firewood stove may reduce firewood consumption and thus release the pressure of gathering firewood on forestland soil fertility.Terrain affects the accessibility to gathering firewood thus affects forestland soil fertility.Other driving forces influencing the relationship between gathering firewood and forestland soil fertility should also be taken into account in the further study.
文摘In this paper, by introducing a proper transformation, the (Gr/G)-expansion method is further extended into the nonlinear reaction diffusion equations in mathematical biology whose balancing numbers may be negative integer. As a result, hyperbolic function solutions and trigonometric function solutions with free parameters are obtained. When the parameters are taken as special values the solitary wave solutions and the periodic wave solutions are also derived from the traveling wave solutions. Moreover, it is observed that the suggested techniques is compatible of such problems.
文摘In this article, we propose an alternative approach of the generalized and improved (G'/G)-expansion method and build some new exact traveling wave solutions of three nonlinear evolution equations, namely the Boiti- Leon-Pempinelle equation, the Pochhammer-Chree equations and the Painleve integrable Burgers equation with free parameters. When the free parameters receive particular values, solitary wave solutions are constructed from the traveling waves. We use the Jacob/elliptic equation as an auxiliary equation in place of the second order linear equation. It is established that the proposed algorithm offers a further influential mathematical tool for constructing exact solutions of nonlinear evolution equations.