The geospatial sciences face grand information technology(IT)challenges in the twenty-first century:data intensity,computing intensity,concurrent access intensity and spatiotemporal intensity.These challenges require ...The geospatial sciences face grand information technology(IT)challenges in the twenty-first century:data intensity,computing intensity,concurrent access intensity and spatiotemporal intensity.These challenges require the readiness of a computing infrastructure that can:(1)better support discovery,access and utilization of data and data processing so as to relieve scientists and engineers of IT tasks and focus on scientific discoveries;(2)provide real-time IT resources to enable real-time applications,such as emergency response;(3)deal with access spikes;and(4)provide more reliable and scalable service for massive numbers of concurrent users to advance public knowledge.The emergence of cloud computing provides a potential solution with an elastic,on-demand computing platform to integrateobservation systems,parameter extracting algorithms,phenomena simulations,analytical visualization and decision support,and to provide social impact and user feedbackthe essential elements of the geospatial sciences.We discuss the utilization of cloud computing to support the intensities of geospatial sciences by reporting from our investigations on how cloud computing could enable the geospatial sciences and how spatiotemporal principles,the kernel of the geospatial sciences,could be utilized to ensure the benefits of cloud computing.Four research examples are presented to analyze how to:(1)search,access and utilize geospatial data;(2)configure computing infrastructure to enable the computability of intensive simulation models;(3)disseminate and utilize research results for massive numbers of concurrent users;and(4)adopt spatiotemporal principles to support spatiotemporal intensive applications.The paper concludes with a discussion of opportunities and challenges for spatial cloud computing(SCC).展开更多
In this short survey, we give a complete list of the most important results obtained by El Naschie’s E-infinity Cantorian space-time theory in the realm of quantum physics and cosmology. Special attention is paid to ...In this short survey, we give a complete list of the most important results obtained by El Naschie’s E-infinity Cantorian space-time theory in the realm of quantum physics and cosmology. Special attention is paid to his recent result on dark energy and revising Einstein’s famous formula .展开更多
The advection-diffusion equation y_t~ε-εy_(xx)~ε+ M y_x~ε= 0,(x, t) ∈(0, 1) ×(0, T) is null controllable for any strictly positive values of the diffusion coefficient ε and of the controllability time T. We...The advection-diffusion equation y_t~ε-εy_(xx)~ε+ M y_x~ε= 0,(x, t) ∈(0, 1) ×(0, T) is null controllable for any strictly positive values of the diffusion coefficient ε and of the controllability time T. We discuss here the behavior of the cost of control when the coefficient ε goes to zero, according to the values of T. It is actually known that this cost is uniformly bounded with respect to ε if T is greater than a minimal time T_M, with T_M in the interval [1, 2×3^(1/2)]/M for M > 0 and in the interval [2×2^(1/2), 2(1 +3^(1/2))]/|M | for M < 0. The exact value of TM is however unknown.We investigate in this work the determination of the minimal time T_M employing two distincts but complementary approaches. In a first one, we numerically estimate the cost of controllability, reformulated as the solution of a generalized eigenvalue problem for the underlying control operator, with respect to the parameter T and ε. This allows notably to exhibit the structure of initial data leading to large costs of control. At the practical level, this evaluation requires the non trivial and challenging approximation of null controls for the advection-diffusion equation. In the second approach, we perform an asymptotic analysis, with respect to the parameter ε, of the optimality system associated to the control of minimal L^2-norm. The matched asymptotic expansion method is used to describe the multiple boundary layers.展开更多
Taking the typical karst agricultural region, Xiaojiang watershed in Luxi of Yurman Province as a research unit, utilizing the groundwater quality data in 1982 and 2004, the aerial photos in 1982 and TM images in 2004...Taking the typical karst agricultural region, Xiaojiang watershed in Luxi of Yurman Province as a research unit, utilizing the groundwater quality data in 1982 and 2004, the aerial photos in 1982 and TM images in 2004, supported by the GIS, we probe into the law and the reason of its space-time change of the groundwater quality over the past 22 years in the paper. The results show： （1） There were obvious temporal and spatial changes of groundwater quality during the past 22 years. （2） Concentrations of NH4^＋, SO4^2- , NO3, NO2^-, Cl^- and the pH value, total hardness, total alkalinity increased significantly, in which NH4^2-, NO3, and NO2^- of groundwater exceeded the drinking water standards as a result of non-point pollution caused by the expansion of cultivated land and mass use of the fertilizer and pesticide. （3） Oppositely, Ca^2＋ and HCO3^- showed an obvious decline trend due to forest reduction and degradation and stony desertification. Meantime, there was a dynamic relation between the groundwater quality change and the land use change.展开更多
Background:Tuberculosis(TB)is still one of the most serious infectious diseases in the mainland of China.So it was urgent for the formulation of more effective measures to prevent and control it.Methods:The data of re...Background:Tuberculosis(TB)is still one of the most serious infectious diseases in the mainland of China.So it was urgent for the formulation of more effective measures to prevent and control it.Methods:The data of reported TB cases in 340 prefectures from the mainland of China were extracted from the China Information System for Disease Control and Prevention(CISDCP)during January 2005 to December 2015.The Kulldorff’s retrospective space-time scan statistics was used to identify the temporal,spatial and spatio-temporal clusters of reported TB in the mainland of China by using the discrete Poisson probability model.Spatio-temporal clusters of sputum smear-positive(SS+)reported TB and sputum smearnegative(SS-)reported TB were also detected at the prefecture level.Results:A total of 10200528 reported TB cases were collected from 2005 to 2015 in 340 prefectures,including 5283983 SS-TB cases and 4631734 SS+TB cases with specific sputum smear results,284811 cases without sputum smear test.Significantly TB clustering patterns in spatial,temporal and spatiotemporal were observed in this research.Results of the Kulldorff’s scan found twelve significant space-time clusters of reported TB.The most likely spatio-temporal cluster(RR=3.27,P<0.001)was mainly located in Xinjiang Uygur Autonomous Region of western China,covering five prefectures and clustering in the time frame from September 2012 to November 2015.The spatio-temporal clustering results of SS+TB and SS-TB also showed the most likely clusters distributed in the western China.However,the clustering time of SS+TB was concentrated before 2010 while SS-TB was mainly concentrated after 2010.Conclusions:This study identified the time and region of TB,SS+TB and SS-TB clustered easily in 340 prefectures in the mainland of China,which is helpful in prioritizing resource assignment in high-risk periods and high-risk areas,and to formulate powerful strategy to prevention and control TB.展开更多
Background:The number of pulmonary tuberculosis(PTB)cases in China ranks third in the world.A continuous increase in cases has recently been recorded in Zhaotong prefecture-level city,which is located in the northeast...Background:The number of pulmonary tuberculosis(PTB)cases in China ranks third in the world.A continuous increase in cases has recently been recorded in Zhaotong prefecture-level city,which is located in the northeastern part of Yunnan province.This study explored the space-time dynamics of PTB cases in Zhaotong to provide useful information that will help guide policymakers to formulate effective regional prevention and control strategies.Methods:The data on PTB cases were extracted from the nationwide tuberculosis online registration system.Time series and spatial cluster analyses were applied to detect PTB temporal trends and spatial patterns at the town level between 2011 and 2015 in Zhaotong.Three indicators of PTB treatment registration history were used:initial treatment registration rate,re-treatment registration rate,and total PTB registration rate.Results:Seasonal trends were detected with an apparent symptom onset peak during the winter season and a registration peak during the spring season.A most likely cluster and six secondary clusters were identified for the total PTB registration rate,one most likely cluster and five secondary clusters for the initial treatment registration rate,and one most likely cluster for the re-treatment registration rate.The most likely cluster of the three indicators had a similar spatial distribution and size in Zhenxiong County,which is characterised by a poor socio-economic level and the largest population in Yunnan.Conclusion:This study identified temporal and spatial distribution of PTB in a high PTB burden area using existing health data.The results of the study provide useful information on the prevailing epidemiological situation of PTB in Zhaotong and could be used to develop strategies for more effective PTB control at the town level.The cluster that overlapped the three PTB indicators falls within the geographic areas where PTB control efforts should be prioritised.展开更多
基金We thank Drs.Huadong Guo and Changlin Wang for inviting us to write this definition and field review paper.Research reported is partially supported by NASA(NNX07AD99G and SMD-09-1448),FGDC(G09AC00103)Environmental Informatics Framework of the Earth,Energy,and Environment Program at Microsoft Research Connection.We thank insightful comments from reviewers including Dr.Aijun Chen(NASA/GMU),Dr.Thomas Huang(NASA JPL),Dr.Cao Kang(Clark Univ.),Krishna Kumar(Microsoft),Dr.Wenwen Li(UCSB),Dr.Michael Peterson(University of Nebraska-Omaha),Dr.Xuan Shi(Geogia Tech),Dr.Tong Zhang(Wuhan University),Jinesh Varia(Amazon)and an anonymous reviewer.This paper is a result from the collaborations/discussions with colleagues from NASA,FGDC,USGS,EPA,GSA,Microsoft,ESIP,AAG CISG,CPGIS,UCGIS,GEO,and ISDE.
文摘The geospatial sciences face grand information technology(IT)challenges in the twenty-first century:data intensity,computing intensity,concurrent access intensity and spatiotemporal intensity.These challenges require the readiness of a computing infrastructure that can:(1)better support discovery,access and utilization of data and data processing so as to relieve scientists and engineers of IT tasks and focus on scientific discoveries;(2)provide real-time IT resources to enable real-time applications,such as emergency response;(3)deal with access spikes;and(4)provide more reliable and scalable service for massive numbers of concurrent users to advance public knowledge.The emergence of cloud computing provides a potential solution with an elastic,on-demand computing platform to integrateobservation systems,parameter extracting algorithms,phenomena simulations,analytical visualization and decision support,and to provide social impact and user feedbackthe essential elements of the geospatial sciences.We discuss the utilization of cloud computing to support the intensities of geospatial sciences by reporting from our investigations on how cloud computing could enable the geospatial sciences and how spatiotemporal principles,the kernel of the geospatial sciences,could be utilized to ensure the benefits of cloud computing.Four research examples are presented to analyze how to:(1)search,access and utilize geospatial data;(2)configure computing infrastructure to enable the computability of intensive simulation models;(3)disseminate and utilize research results for massive numbers of concurrent users;and(4)adopt spatiotemporal principles to support spatiotemporal intensive applications.The paper concludes with a discussion of opportunities and challenges for spatial cloud computing(SCC).
文摘In this short survey, we give a complete list of the most important results obtained by El Naschie’s E-infinity Cantorian space-time theory in the realm of quantum physics and cosmology. Special attention is paid to his recent result on dark energy and revising Einstein’s famous formula .
文摘The advection-diffusion equation y_t~ε-εy_(xx)~ε+ M y_x~ε= 0,(x, t) ∈(0, 1) ×(0, T) is null controllable for any strictly positive values of the diffusion coefficient ε and of the controllability time T. We discuss here the behavior of the cost of control when the coefficient ε goes to zero, according to the values of T. It is actually known that this cost is uniformly bounded with respect to ε if T is greater than a minimal time T_M, with T_M in the interval [1, 2×3^(1/2)]/M for M > 0 and in the interval [2×2^(1/2), 2(1 +3^(1/2))]/|M | for M < 0. The exact value of TM is however unknown.We investigate in this work the determination of the minimal time T_M employing two distincts but complementary approaches. In a first one, we numerically estimate the cost of controllability, reformulated as the solution of a generalized eigenvalue problem for the underlying control operator, with respect to the parameter T and ε. This allows notably to exhibit the structure of initial data leading to large costs of control. At the practical level, this evaluation requires the non trivial and challenging approximation of null controls for the advection-diffusion equation. In the second approach, we perform an asymptotic analysis, with respect to the parameter ε, of the optimality system associated to the control of minimal L^2-norm. The matched asymptotic expansion method is used to describe the multiple boundary layers.
基金Doctorate Foundation of Southwest University, No.SWNUB2005035 Open Foundation of Physical Geography of Southwest University, No.250-411109+2 种基金 Foundation of Science and Technology Committee of Chongqing, No.20027534 No.20048258 The project of Ministry of Land and Resources, No.200310400024
文摘Taking the typical karst agricultural region, Xiaojiang watershed in Luxi of Yurman Province as a research unit, utilizing the groundwater quality data in 1982 and 2004, the aerial photos in 1982 and TM images in 2004, supported by the GIS, we probe into the law and the reason of its space-time change of the groundwater quality over the past 22 years in the paper. The results show： （1） There were obvious temporal and spatial changes of groundwater quality during the past 22 years. （2） Concentrations of NH4^＋, SO4^2- , NO3, NO2^-, Cl^- and the pH value, total hardness, total alkalinity increased significantly, in which NH4^2-, NO3, and NO2^- of groundwater exceeded the drinking water standards as a result of non-point pollution caused by the expansion of cultivated land and mass use of the fertilizer and pesticide. （3） Oppositely, Ca^2＋ and HCO3^- showed an obvious decline trend due to forest reduction and degradation and stony desertification. Meantime, there was a dynamic relation between the groundwater quality change and the land use change.
基金The research was supported by the National S&T Major Project(Grant No.2014ZX10004005–001).
文摘Background:Tuberculosis(TB)is still one of the most serious infectious diseases in the mainland of China.So it was urgent for the formulation of more effective measures to prevent and control it.Methods:The data of reported TB cases in 340 prefectures from the mainland of China were extracted from the China Information System for Disease Control and Prevention(CISDCP)during January 2005 to December 2015.The Kulldorff’s retrospective space-time scan statistics was used to identify the temporal,spatial and spatio-temporal clusters of reported TB in the mainland of China by using the discrete Poisson probability model.Spatio-temporal clusters of sputum smear-positive(SS+)reported TB and sputum smearnegative(SS-)reported TB were also detected at the prefecture level.Results:A total of 10200528 reported TB cases were collected from 2005 to 2015 in 340 prefectures,including 5283983 SS-TB cases and 4631734 SS+TB cases with specific sputum smear results,284811 cases without sputum smear test.Significantly TB clustering patterns in spatial,temporal and spatiotemporal were observed in this research.Results of the Kulldorff’s scan found twelve significant space-time clusters of reported TB.The most likely spatio-temporal cluster(RR=3.27,P<0.001)was mainly located in Xinjiang Uygur Autonomous Region of western China,covering five prefectures and clustering in the time frame from September 2012 to November 2015.The spatio-temporal clustering results of SS+TB and SS-TB also showed the most likely clusters distributed in the western China.However,the clustering time of SS+TB was concentrated before 2010 while SS-TB was mainly concentrated after 2010.Conclusions:This study identified the time and region of TB,SS+TB and SS-TB clustered easily in 340 prefectures in the mainland of China,which is helpful in prioritizing resource assignment in high-risk periods and high-risk areas,and to formulate powerful strategy to prevention and control TB.
基金This study was supported by the National Special Science and Technology Project for Major Infectious Diseases of China(Grant No.2012ZX10004-220,2016ZX10004222-006)the China-UK Global Health Support Programme(Grant No.:GHSP-CS-OP1-01)+1 种基金The Forth Round of Three-Year Public Health Action Plan of Shanghai,China(No.15GWZK0101,GWIV-29)The funders had no role in the study design,data collection and analysis,decision to publish,or preparation of the paper。
文摘Background:The number of pulmonary tuberculosis(PTB)cases in China ranks third in the world.A continuous increase in cases has recently been recorded in Zhaotong prefecture-level city,which is located in the northeastern part of Yunnan province.This study explored the space-time dynamics of PTB cases in Zhaotong to provide useful information that will help guide policymakers to formulate effective regional prevention and control strategies.Methods:The data on PTB cases were extracted from the nationwide tuberculosis online registration system.Time series and spatial cluster analyses were applied to detect PTB temporal trends and spatial patterns at the town level between 2011 and 2015 in Zhaotong.Three indicators of PTB treatment registration history were used:initial treatment registration rate,re-treatment registration rate,and total PTB registration rate.Results:Seasonal trends were detected with an apparent symptom onset peak during the winter season and a registration peak during the spring season.A most likely cluster and six secondary clusters were identified for the total PTB registration rate,one most likely cluster and five secondary clusters for the initial treatment registration rate,and one most likely cluster for the re-treatment registration rate.The most likely cluster of the three indicators had a similar spatial distribution and size in Zhenxiong County,which is characterised by a poor socio-economic level and the largest population in Yunnan.Conclusion:This study identified temporal and spatial distribution of PTB in a high PTB burden area using existing health data.The results of the study provide useful information on the prevailing epidemiological situation of PTB in Zhaotong and could be used to develop strategies for more effective PTB control at the town level.The cluster that overlapped the three PTB indicators falls within the geographic areas where PTB control efforts should be prioritised.
