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Approach to General Data Model of GIS Symbol Library and Symbol Library Data Exchange XML Schema 被引量:4
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作者 LI Qingyuan SU Deguo LI Hongsheng LIU Haochen SUN Lijian 《Geo-Spatial Information Science》 2009年第4期235-242,共8页
Symbol portrayal is an important function of GIS. Sharing symbolic information in different GIS platforms is necessary for GIS applications and users. This paper discusses the necessity, possibility and solution techn... Symbol portrayal is an important function of GIS. Sharing symbolic information in different GIS platforms is necessary for GIS applications and users. This paper discusses the necessity, possibility and solution technique of sharing a symbol library in different GIS platforms. The route map is designed as follows: first, to set up a general data model for the symbol library, then to design a standard exchange format, and finally to call on the GIS manufacturer to provide the interchange tools for their symbol library for the standard exchange format. This paper analyzes the general characteristics of GIS symbolic library, gives a symbol library model and a draft of XML schema of the symbol library exchange format. 展开更多
关键词 GIS symbol library general data model exchange format XML schema
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INCOMPRESSIBLE LIMIT OF IDEAL MAGNETOHYDRODYNAMICS IN A DOMAIN WITH BOUNDARIES
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作者 Qiangchang JU Jiawei WANG 《Acta Mathematica Scientia》 SCIE CSCD 2024年第4期1441-1465,共25页
We study the incompressible limit of classical solutions to compressible ideal magneto-hydrodynamics in a domain with a flat boundary.The boundary condition is characteristic and the initial data is general.We first e... We study the incompressible limit of classical solutions to compressible ideal magneto-hydrodynamics in a domain with a flat boundary.The boundary condition is characteristic and the initial data is general.We first establish the uniform existence of classical solutions with respect to the Mach number.Then,we prove that the solutions converge to the solution of the incompressible MHD system.In particular,we obtain a stronger convergence result by using the dispersion of acoustic waves in the half space. 展开更多
关键词 incompressible limit ideal MHD equations boundary condition general initial data
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Latitudinal migration of sunspots based on the ESAI database
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作者 Juan Zhang Fu-Yu Li Wen Feng 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2018年第1期83-94,共12页
The latitudinal migration of sunspots toward the equator,which implies there is propagation of the toroidal magnetic flux wave at the base of the solar convection zone,is one of the crucial observational bases for the... The latitudinal migration of sunspots toward the equator,which implies there is propagation of the toroidal magnetic flux wave at the base of the solar convection zone,is one of the crucial observational bases for the solar dynamo to generate a magnetic field by shearing of the pre-existing poloidal magnetic field through differential rotation.The Extended time series of Solar Activity Indices(ESAI)elongated the Greenwich observation record of sunspots by several decades in the past.In this study,ESAI's yearly mean latitude of sunspots in the northern and southern hemispheres during the years 1854 to 1985 is utilized to statistically test whether hemispherical latitudinal migration of sunspots in a solar cycle is linear or nonlinear.It is found that a quadratic function is statistically significantly better at describing hemispherical latitudinal migration of sunspots in a solar cycle than a linear function.In addition,the latitude migration velocity of sunspots in a solar cycle decreases as the cycle progresses,providing a particular constraint for solar dynamo models.Indeed,the butterfly wing pattern with a faster latitudinal migration rate should present stronger solar activity with a shorter cycle period,and it is located at higher latitudinal position,giving evidence to support the Babcock-Leighton dynamo mechanism. 展开更多
关键词 Sun:activity Sun:general Sun:sunspots methods:data analysis
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U.S.and International Legal Perspectives Affecting Cybersecurity Corporate Governance
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作者 Paul J.Morrow Thomas M.Fitzpatrick 《International Relations and Diplomacy》 2020年第6期231-239,共9页
International and U.S.corporations must be well advised regarding specific regulations and laws that affect cybersecurity decisions because the Board of Directors must perform due diligence to avoid regulatory neglige... International and U.S.corporations must be well advised regarding specific regulations and laws that affect cybersecurity decisions because the Board of Directors must perform due diligence to avoid regulatory negligence and lawsuit liability.Depending on the standards and the regulations that do define reasonable care,the corporate director is faced with the challenge of determining how and what cybersecurity laws apply.Then,directors can institute best cybersecurity management practices.This paper provides guidance regarding the application of the law in the areas of cyber security for the international corporations interacting with the European General Data Protection Regulations(GDPR),the California Consumer Privacy Act(CCPA),and recent Federal Trade Commission(FTC)administrative agency rulings.Reading this paper is worth your time because it will inform you of the legal challenges that international and domestic corporations face in making decisions about spending capital to manage cybersecurity and at the same time perform due diligence.In other words,if there is a cybersecurity breach,this paper will provide insights into what law must be followed by the corporation enabling the best management decisions assuring adequate response,compliance,thereby avoiding unnecessary liability risk.The paper also provides reflections about whether the GDPR serves as a better legal comprehensive regulatory model rather than the recently enacted laws in the U.S. 展开更多
关键词 cybersecurity compliance general data Protection Regulation California Consumer Privacy Act data privacy Federal Trade Commission
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International Cybersecurity Breach Detection Risk, Prosecution and Resolution
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作者 Paul J.Morrow Thomas M.Fitzpatrick 《International Relations and Diplomacy》 2021年第5期173-181,共9页
The U.S.and the international business community is in a crisis regarding ransomware attacks and cybersecurity policing/regulation.Based on recent events,state sponsored cyber hackers have made it their mission to hol... The U.S.and the international business community is in a crisis regarding ransomware attacks and cybersecurity policing/regulation.Based on recent events,state sponsored cyber hackers have made it their mission to hold the information security world hostage extorting money for a returning of data systems to normal functioning.This paper examines the challenges for the global business community regarding the scope of the attacks,the current state of the law in the U.S.intended to provide current information to the international business community,illustrate the challenges for regulators and the courts,illustrate the recent progress of the criminal investigatory aspects of apprehending cybercriminals,report on the non-delegable duties of decision makers in the international community doing business in the U.S.,and demonstrate the potential solutions to this evolving international crisis.It is worth your time to read this paper for the following reasons:1.Understanding the risks and the scope of the problem moving forward with doing business in the U.S.;2.communicating recent developments fostering cooperation and contributing to mediating cybersecurity events for international corporations;and 3.providing information on the current state of the law by the U.S.Supreme Court pointing out the relevant and the consequential outcomes of the legal system leading to potential smart solutions for planning business decisions. 展开更多
关键词 cybersecurity compliance general data protection regulation California Consumer Privacy Act data privacy Federal Trade Commission
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Asymptotic limit of the Gross-Pitaevskii equation with general initial data
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作者 LI FuCai LIN Chi-Kun WU Kung-Chien 《Science China Mathematics》 SCIE CSCD 2016年第6期1113-1126,共14页
This paper mainly concerns the mathematical justification of the asymptotic limit of the GrossPitaevskii equation with general initial data in the natural energy space over the whole space. We give a rigorous proof of... This paper mainly concerns the mathematical justification of the asymptotic limit of the GrossPitaevskii equation with general initial data in the natural energy space over the whole space. We give a rigorous proof of the convergence of the velocity fields defined through the solutions of the Gross-Pitaevskii equation to the strong solution of the incompressible Euler equations. Furthermore, we also obtain the rates of the convergence. 展开更多
关键词 Gross-Pitaevskii equation asymptotic limit incompressible Euler equation general initial data
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Existence and uniqueness of global classical solutions to 3D isentropic compressible Navier-Stokes equations with general initial data
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作者 ZHANG PeiXin ZHAO JunNing 《Science China Mathematics》 SCIE 2014年第7期1463-1478,共16页
In this paper we study the global existence and uniqueness of classical solutions to the Cauchy problem for 3D isentropic compressible Navier-Stokes equations with general initial data which could contain vacuum.We gi... In this paper we study the global existence and uniqueness of classical solutions to the Cauchy problem for 3D isentropic compressible Navier-Stokes equations with general initial data which could contain vacuum.We give the relation between the viscosity coefficients and the initial energy,which implies that the Cauchy problem under consideration has a global classical solution. 展开更多
关键词 compressible Navier-Stokes equations general initial data global classical solutions
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Automated Separation of Stars and Normal Galaxies Based on Statistical Mixture Modeling with RBF Neural Networks 被引量:1
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作者 Dong-MeiQin PingGuo Yong-HengZhao 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2003年第3期277-286,共10页
For LAMOST, the largest sky survey program in China, the solution of the problem of automatic discrimination of stars from galaxies by spectra has shown that the results of the PSF test can be significantly refined. H... For LAMOST, the largest sky survey program in China, the solution of the problem of automatic discrimination of stars from galaxies by spectra has shown that the results of the PSF test can be significantly refined. However, the problem is made worse when the redshifts of galaxies are not available. We present a new automatic method of star/(normal) galaxy separation, which is based on Statistical Mixture Modeling with Radial Basis Function Neural Networks (SMM-RBFNN). This work is a continuation of our previous one, where active and non-active celestial objects were successfully segregated. By combining the method in this paper and the previous one, stars can now be effectively separated from galaxies and AGNs by their spectra-a major goal of LAMOST, and an indispensable step in any automatic spectrum classification system. In our work, the training set includes standard stellar spectra from Jacoby's spectrum library and simulated galaxy spectra of EO, SO, Sa, Sb types with redshift ranging from 0 to 1.2, and the test set of stellar spectra from Pickles' atlas and SDSS spectra of normal galaxies with SNR of 13. Experiments show that our SMM-RBFNN is more efficient in both the training and testing stages than the BPNN (back propagation neural networks), and more importantly, it can achieve a good classification accuracy of 99.22% and 96.52%, respectively for stars and normal galaxies. 展开更多
关键词 methods: data analysis - techniques: spectroscopic - stars: general - galaxies: stellar content
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Mass segregation of embedded clusters in the Milky Way
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作者 Xin-Yue Er Zhi-Bo Jiang Yan-Ning Fu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2013年第3期277-289,共13页
Embedded clusters are ideal laboratories for understanding the early phase of the dynamical evolution of clusters as well as massive star formation. An interesting observational phenomenon is that some of the embedded... Embedded clusters are ideal laboratories for understanding the early phase of the dynamical evolution of clusters as well as massive star formation. An interesting observational phenomenon is that some of the embedded clusters show mass segregation, i.e., the most massive stars are preferentially found near the cluster center. We develop a new approach to describe mass segregation. Using this approach and the Two Micron All Sky Survey Point Source Catalog (2MASS PSC), we analyze 18 embedded clusters in the Galaxy. We find that 11 of them are mass-segregated and that the others are not mass-segregated. No inversely mass-segregated cluster is found. 展开更多
关键词 open clusters and associations: general -- stars: formation -- methods:data analysis
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An Overview of Data Mining and Knowledge Discovery 被引量:8
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作者 范建华 李德毅 《Journal of Computer Science & Technology》 SCIE EI CSCD 1998年第4期348-368,共21页
With massive amounts of data stored in databases, mining information and knowledge in databases has become an important issue in recent research. Researchers in many different fields have shown great interest in data ... With massive amounts of data stored in databases, mining information and knowledge in databases has become an important issue in recent research. Researchers in many different fields have shown great interest in data mining and knowledge discovery in databases. Several emerging applications in information providing services, such as data warehousing and on-line services over the Internet, also call for various data mining and knowledge discovery techniques to understand user behavior better, to improve the service provided, and to increase the business opportunities. In response to such a demand, this article is to provide a comprehensive survey on the data mining and knowledge discovery techniques developed recently, and introduce some real application systems as well. In conclusion, this article also lists some problems and challenges for further research. 展开更多
关键词 Knowledge discovery in databases data mining machine learning association rule CLASSIFICATION data clustering data generalization pattern searching
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Novel approaches to the multiscalar display of vector data
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作者 NIU Fangqu CHENG Changxiu 《Geo-Spatial Information Science》 SCIE EI 2012年第4期251-261,共11页
There are many challenges to achieving quality multiscalar displays of vector data in geographical information system(GIS).Acknowledging and making use of the differences between traditional cartographic generalizatio... There are many challenges to achieving quality multiscalar displays of vector data in geographical information system(GIS).Acknowledging and making use of the differences between traditional cartographic generalization and multiscalar display in GIS,this paper focuses on novel approaches to the definition of small objects and the establishment of scale sequence.The ease of implementation and efficacy of the solutions proposed are exemplified and analyzed.Possibilities for further research into the multiscalar display of vector data in GIS are thereby suggested. 展开更多
关键词 data generalization multiscale GIS generalization rectangle scale sequence
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