期刊文献+
共找到31,915篇文章
< 1 2 250 >
每页显示 20 50 100
An Adaptive Lasso Grey Model for Regional FDI Statistics Prediction
1
作者 Juan Huang Bifang Zhou +2 位作者 Huajun Huang Jianjiang Liu Neal N.Xiong 《Computers, Materials & Continua》 SCIE EI 2021年第11期2111-2121,共11页
To overcome the deficiency of traditional mathematical statistics methods,an adaptive Lasso grey model algorithm for regional FDI(foreign direct investment)prediction is proposed in this paper,and its validity is anal... To overcome the deficiency of traditional mathematical statistics methods,an adaptive Lasso grey model algorithm for regional FDI(foreign direct investment)prediction is proposed in this paper,and its validity is analyzed.Firstly,the characteristics of the FDI data in six provinces of Central China are generalized,and the mixture model’s constituent variables of the Lasso grey problem as well as the grey model are defined.Next,based on the influencing factors of regional FDI statistics(mean values of regional FDI and median values of regional FDI),an adaptive Lasso grey model algorithm for regional FDI was established.Then,an application test in Central China is taken as a case study to illustrate the feasibility of the adaptive Lasso grey model algorithm in regional FDI prediction.We also select RMSE(root mean square error)and MAE(mean absolute error)to demonstrate the convergence and the validity of the algorithm.Finally,we train this proposedal gorithm according to the regional FDI statistical data in six provinces in Central China from 2006 to 2018.We then use it to predict the regional FDI statistical data from 2019 to 2023 and show its changing tendency.The extended work for the adaptive Lasso grey model algorithm and its procedure to other regional economic fields is also discussed. 展开更多
关键词 Adaptive lasso grey model algorithm regional fdi statistics mean value of regional fdi median value of regional fdi
在线阅读 下载PDF
FDI对我国产业结构影响的区域差异——基于地级及以上城市的Panel Data分析 被引量:3
2
作者 吴艳 贾忠 《社会科学研究》 CSSCI 北大核心 2014年第6期24-27,共4页
研究表明,FDI对我国东中西部产业结构优化都显示为正向促进作用,且表现为西部大于中部、中部大于东部;在其他条件不变情况下,西部地区每多引进利用外资100万美元,第三产业占比将提升约4.67个百分点,而中部和东部分别为1.35和0.33个百分... 研究表明,FDI对我国东中西部产业结构优化都显示为正向促进作用,且表现为西部大于中部、中部大于东部;在其他条件不变情况下,西部地区每多引进利用外资100万美元,第三产业占比将提升约4.67个百分点,而中部和东部分别为1.35和0.33个百分点。下一步应在全面深化经济发展改革,营造外商直接投资良好环境的基础上,通过利用FDI优化产业结构,同时在FDI的引进和利用中应因势利导、因地制宜。 展开更多
关键词 fdi 产业结构 地区差异 PANEL data模型
在线阅读 下载PDF
GPS probe map matching algorithm based on spatial data model 被引量:1
3
作者 王卫 过秀成 侯佳 《Journal of Southeast University(English Edition)》 EI CAS 2010年第3期461-465,共5页
To improve the performance of the traditional map matching algorithms in freeway traffic state monitoring systems using the low logging frequency GPS (global positioning system) probe data, a map matching algorithm ... To improve the performance of the traditional map matching algorithms in freeway traffic state monitoring systems using the low logging frequency GPS (global positioning system) probe data, a map matching algorithm based on the Oracle spatial data model is proposed. The algorithm uses the Oracle road network data model to analyze the spatial relationships between massive GPS positioning points and freeway networks, builds an N-shortest path algorithm to find reasonable candidate routes between GPS positioning points efficiently, and uses the fuzzy logic inference system to determine the final matched traveling route. According to the implementation with field data from Los Angeles, the computation speed of the algorithm is about 135 GPS positioning points per second and the accuracy is 98.9%. The results demonstrate the effectiveness and accuracy of the proposed algorithm for mapping massive GPS positioning data onto freeway networks with complex geometric characteristics. 展开更多
关键词 GPS probe map matching A-star algorithm fuzzy logic Oracle spatial data model
在线阅读 下载PDF
基于PANEL DATA模型的山东省FDI与经济发展关系的实证分析 被引量:1
4
作者 曹圆圆 《山东商业职业技术学院学报》 2007年第1期15-18,共4页
采用Panel data计量模型和经济学方法,分析了山东省外商直接投资(FDI)和经济增长的关系,得出了它们之间的多个实证模型,对我省在引进外资方面应采取的对策与措施提出了几点建议。
关键词 fdi PANEL data模型 柯布-道格拉斯生产函数
在线阅读 下载PDF
俄罗斯利用FDI的经济增长效应分析——基于Panel Data的研究 被引量:2
5
作者 谭蓉娟 《亚太经济》 CSSCI 北大核心 2008年第2期73-77,共5页
进入新世纪以来,全球FDI地区流动特点表现为投资主流正在从传统的投资区域转向某些新兴的市场,俄罗斯联邦近年来由于能源行业蓬勃发展,其吸引FDI的能力大幅提升。本文通过对俄罗斯七个联邦区1999-2005年的相关数据进行面板数据分析... 进入新世纪以来,全球FDI地区流动特点表现为投资主流正在从传统的投资区域转向某些新兴的市场,俄罗斯联邦近年来由于能源行业蓬勃发展,其吸引FDI的能力大幅提升。本文通过对俄罗斯七个联邦区1999-2005年的相关数据进行面板数据分析,对影响俄罗斯联邦经济发展的因素进行剖析,对其FDI的经济增长效应进行研究。 展开更多
关键词 俄罗斯联邦 fdi 经济增长效应 面板数据
在线阅读 下载PDF
OBJECT ORIENTED DATA MODELLING WITH APPLICATIONS TO CAD
6
作者 应维云 傅向阳 周儒荣 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1996年第2期69+63-68,共7页
An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introdu... An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introduced herewith. A feasible approach to select the “best” data model for an application is to analyze the data which has to be stored in the database. A data model is appropriate for modelling a given task if the information of the application environment can be easily mapped to the data model. Thus, the involved data are analyzed and then object oriented data model appropriate for CAD applications are derived. Based on the reviewed object oriented techniques applied in CAD, object oriented data modelling in CAD is addressed in details. At last 3D geometrical data models and implementation of their data model using the object oriented method are presented. 展开更多
关键词 computer aided design dataBASES data models object oriented data models complex objects geometrical models
在线阅读 下载PDF
FDI对中国收入分配影响的panel data模型分析 被引量:3
7
作者 林宏 《浙江统计》 2005年第3期19-21,共3页
关键词 fdi panel 收入分配 模型分析 data 经济学理论研究 中国 人力资源开发 外国直接投资 国际贸易 理论与实践 资本形成 经济增长 外溢效应 标准理论 静态方法 局部均衡 东道国 复合体 技术 知识
在线阅读 下载PDF
热网FDI攻击的非侵入式检测方法
8
作者 刘鑫蕊 张修宇 +2 位作者 吴泽群 王睿 孙秋野 《控制理论与应用》 北大核心 2025年第7期1265-1274,共10页
针对热网易受网络攻击影响且惯性大的问题,为提高热网攻击检测的快速性和准确性,本文首次提出了一种能够放大攻击带来的状态量偏差的非侵入式在线检测方法,该方法首先将居住人热行为归纳为黑盒模型,将房屋和散热器归纳为白盒模型,通过... 针对热网易受网络攻击影响且惯性大的问题,为提高热网攻击检测的快速性和准确性,本文首次提出了一种能够放大攻击带来的状态量偏差的非侵入式在线检测方法,该方法首先将居住人热行为归纳为黑盒模型,将房屋和散热器归纳为白盒模型,通过白盒与黑盒组成的灰盒模型来计算室内热平衡状态,其次以室内温度为输入/散失热量计算的中间量,放大攻击带来的系统状态量偏差,最后通过多重匹配状态预测方法进行攻击检测.为验证所提方法的有效性,采用巴厘岛热网模型进行仿真实验,与传统的检测方法相比,本文所提方法可以有效放大攻击带来的状态量偏差,检测速度和检测率均更高. 展开更多
关键词 fdi 网络攻击 非侵入式检测 灰盒模型 热网
在线阅读 下载PDF
A Trajectory-Oriented, Carriageway-Based Road Network Data Model,Part 2:Methodology 被引量:10
9
作者 LI Xiang LIN Hui 《Geo-Spatial Information Science》 2006年第2期112-117,150,共7页
This is the second of a three-part series of papers which presents the principle and architecture of the CRNM, a trajectory-oriented, carriageway-based road network data model. The first part of the series has introdu... This is the second of a three-part series of papers which presents the principle and architecture of the CRNM, a trajectory-oriented, carriageway-based road network data model. The first part of the series has introduced a general background of building trajectory-oriented road network data models, including motivation, related works, and basic concepts. Based on it, this paper describs the CRNM in detail. At first, the notion of basic roadway entity is proposed and discussed. Secondly, carriageway is selected as the basic roadway entity after compared with other kinds of roadway, and approaches to representing other roadways with carriageways are introduced. At last, an overall architecture of the CRNM is proposed. 展开更多
关键词 TRAJECTORY road network data model CARRIAGEWAY GIS GIS-T
在线阅读 下载PDF
A Trajectory-Oriented Carriageway-Based Road Network Data Model, Part 1: Background 被引量:10
10
作者 LI Xiang LIN Hui 《Geo-Spatial Information Science》 2006年第1期65-70,共6页
This is the first of a three-part series of pape rs which introduces a general background of building trajectory-oriented road net work data models, including motivation, related works, and basic concepts. The p urpos... This is the first of a three-part series of pape rs which introduces a general background of building trajectory-oriented road net work data models, including motivation, related works, and basic concepts. The p urpose of the series is to develop a trajectory-oriented road network data mode l, namely carriageway-based road network data model (CRNM). Part 1 deals with t he modeling background. Part 2 proposes the principle and architecture of the CR NM. Part 3 investigates the implementation of the CRNM in a case study. In the p resent paper, the challenges of managing trajectory data are discussed. Then, de veloping trajectory-oriented road network data models is proposed as a solution and existing road network data models are reviewed. Basic representation approa ches of a road network are introduced as well as its constitution. 展开更多
关键词 TRAJECTORY road network data model CARRIAGEWAY GIS GIS-T
在线阅读 下载PDF
XML-based integration data model and schema mappingin multidatabase systems 被引量:5
11
作者 LiRuixuan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第2期437-444,共8页
Multidatabase systems are designed to achieve schema integration and data interoperation among distributed and heterogeneous database systems. But data model heterogeneity and schema heterogeneity make this a challeng... Multidatabase systems are designed to achieve schema integration and data interoperation among distributed and heterogeneous database systems. But data model heterogeneity and schema heterogeneity make this a challenging task. A multidatabase common data model is firstly introduced based on XML, named XML-based Integration Data Model (XIDM), which is suitable for integrating different types of schemas. Then an approach of schema mappings based on XIDM in multidatabase systems has been presented. The mappings include global mappings, dealing with horizontal and vertical partitioning between global schemas and export schemas, and local mappings, processing the transformation between export schemas and local schemas. Finally, the illustration and implementation of schema mappings in a multidatabase prototype - Panorama system are also discussed. The implementation results demonstrate that the XIDM is an efficient model for managing multiple heterogeneous data sources and the approaches of schema mapping based on XIDM behave very well when integrating relational, object-oriented database systems and other file systems. 展开更多
关键词 multidatabase systems common data model schema mapping extensible markup language (XML).
在线阅读 下载PDF
A Trajectory-Oriented Carriageway-Based Road Network Data Model, Part 3: Implementation 被引量:6
12
作者 LI Xiang LIN Hui 《Geo-Spatial Information Science》 2006年第3期201-205,共5页
This is the final of a three-part series of papers which mainly discusses the implementation issues of the CRNM. The first two papers in the series have introduced the modeling background and methodology, respectively... This is the final of a three-part series of papers which mainly discusses the implementation issues of the CRNM. The first two papers in the series have introduced the modeling background and methodology, respectively. An overall architecture of the CRNM has been proposed in the last paper. On the basis of the above discusses, a linear reference method (LRM) for providing spatial references for location points of a trajectory is developed. A case study is introduced to illustrate the application of the CRNM for modeling a road network in the real world is given. A comprehensive conclusion is given for the series of papers. 展开更多
关键词 TRAJECTORY road network data model CARRIAGEWAY GIS GIS-T
在线阅读 下载PDF
Constructing a raster-based spatio-temporal hierarchical data model for marine fisheries application 被引量:2
13
作者 SU Fenzhen ZHOU Chenhu ZHANG Tianyu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2006年第1期57-63,共7页
Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently... Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently, greater emphasis has been placed on GIS (geographical information system)to deal with the marine information. The GIS has shown great success for terrestrial applications in the last decades, but its use in marine fields has been far more restricted. One of the main reasons is that most of the GIS systems or their data models are designed for land applications. They cannot do well with the nature of the marine environment and for the marine information. And this becomes a fundamental challenge to the traditional GIS and its data structure. This work designed a data model, the raster-based spatio-temporal hierarchical data model (RSHDM), for the marine information system, or for the knowledge discovery fi'om spatio-temporal data, which bases itself on the nature of the marine data and overcomes the shortages of the current spatio-temporal models when they are used in the field. As an experiment, the marine fishery data warehouse (FDW) for marine fishery management was set up, which was based on the RSHDM. The experiment proved that the RSHDM can do well with the data and can extract easily the aggregations that the management needs at different levels. 展开更多
关键词 marine geographical information system spatio-temporal data model knowledge discovery fishery management data warehouse
在线阅读 下载PDF
长江经济带FDI与区域协调发展空间交互影响研究
14
作者 金飞 孙攀 《长江流域资源与环境》 北大核心 2025年第3期522-533,共12页
FDI是利用高质量外资的重要抓手,区域协调发展战略是党的十六届三中全会提出的“五个统筹”之一。因此,在国家大力推进高质量发展的背景下,厘清两者之间的关系尤为重要。构建区域协调发展评价指标体系,并采用熵值法测度出其具体数值;基... FDI是利用高质量外资的重要抓手,区域协调发展战略是党的十六届三中全会提出的“五个统筹”之一。因此,在国家大力推进高质量发展的背景下,厘清两者之间的关系尤为重要。构建区域协调发展评价指标体系,并采用熵值法测度出其具体数值;基于1990~2022年长江经济带11个省域的面板数据,采用全域莫兰指数对FDI与区域协调发展的空间自相关性进行检验,在此基础上,运用效应值可分解的空间联立方程模型,探究FDI与区域协调发展之间存在的交互影响。结果表明:(1)FDI与区域协调发展相互促进。(2)FDI与区域协调发展都存在显著的正向空间溢出效应。该文对高水平对外开放背景下利用高质量外资,以及深入推进区域协调发展战略具有重要的理论价值和实践意义。 展开更多
关键词 fdi 区域协调发展 空间联立方程模型 长江经济带
原文传递
Approach to General Data Model of GIS Symbol Library and Symbol Library Data Exchange XML Schema 被引量:4
15
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
原文传递
Component-based Topological Data Model for Three-dimensional Geology Modeling 被引量:3
16
作者 HOUEnke WULixin WUYuhua JUTianyi 《Geo-Spatial Information Science》 2005年第2期122-127,共6页
On the study of the basic characteristics of geological objects and the special requirement for computing 3D geological model, this paper gives an object-oriented 3D topologic data model. In this model, the geological... On the study of the basic characteristics of geological objects and the special requirement for computing 3D geological model, this paper gives an object-oriented 3D topologic data model. In this model, the geological objects are divided into four object classes: point, line, area and volume. The volume class is further divided into four subclasses: the composite volume, the complex volume, the simple volume and the component. Twelve kinds of topological relations and the related data structures are designed for the geological objects. 展开更多
关键词 geology modeling 3D data models 3DGIS
在线阅读 下载PDF
Panel data models with cross-sectional dependence: a selective review 被引量:2
17
作者 XU Qiu-hua CAI Zong-wu FANG Ying 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2016年第2期127-147,共21页
In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues... In this review, we highlight some recent methodological and theoretical develop- ments in estimation and testing of large panel data models with cross-sectional dependence. The paper begins with a discussion of issues of cross-sectional dependence, and introduces the concepts of weak and strong cross-sectional dependence. Then, the main attention is primarily paid to spatial and factor approaches for modeling cross-sectional dependence for both linear and nonlinear (nonparametric and semiparametric) panel data models. Finally, we conclude with some speculations on future research directions. 展开更多
关键词 Panel data models Cross-sectional dependence Spatial dependence Interactive fixed effects Common factors.
在线阅读 下载PDF
DEVELOPMENT OF A GIS DATA MODEL WITH SPATIAL,TEMPORAL AND ATTRIBUTE COMPONENTS BASED ON OBJECT-ORIENTED APPROACH 被引量:2
18
作者 SHI Wenzhong ZHANG Minwen 《Geo-Spatial Information Science》 2000年第1期17-23,共7页
This paper presents a conceptual data model, the STA-model, for handling spatial, temporal and attribute aspects of objects in GIS. The model is developed on the basis of object-oriented modeling approach. This model ... This paper presents a conceptual data model, the STA-model, for handling spatial, temporal and attribute aspects of objects in GIS. The model is developed on the basis of object-oriented modeling approach. This model includes two major parts: (a) modeling the signal objects by STA-object elements, and (b) modeling relationships between STA-objects. As an example, the STA-model is applied for modeling land cover change data with spatial, temporal and attribute components. 展开更多
关键词 OBJECT-ORIENTATION GIS data modeling spatial temporal and attribute model
在线阅读 下载PDF
A Spatio-temporal Data Model for Road Network in Data Center Based on Incremental Updating in Vehicle Navigation System 被引量:1
19
作者 WU Huisheng LIU Zhaoli +1 位作者 ZHANG Shuwen ZUO Xiuling 《Chinese Geographical Science》 SCIE CSCD 2011年第3期346-353,共8页
The technique of incremental updating,which can better guarantee the real-time situation of navigational map,is the developing orientation of navigational road network updating.The data center of vehicle navigation sy... The technique of incremental updating,which can better guarantee the real-time situation of navigational map,is the developing orientation of navigational road network updating.The data center of vehicle navigation system is in charge of storing incremental data,and the spatio-temporal data model for storing incremental data does affect the efficiency of the response of the data center to the requirements of incremental data from the vehicle terminal.According to the analysis on the shortcomings of several typical spatio-temporal data models used in the data center and based on the base map with overlay model,the reverse map with overlay model (RMOM) was put forward for the data center to make rapid response to incremental data request.RMOM supports the data center to store not only the current complete road network data,but also the overlays of incremental data from the time when each road network changed to the current moment.Moreover,the storage mechanism and index structure of the incremental data were designed,and the implementation algorithm of RMOM was developed.Taking navigational road network in Guangzhou City as an example,the simulation test was conducted to validate the efficiency of RMOM.Results show that the navigation database in the data center can response to the requirements of incremental data by only one query with RMOM,and costs less time.Compared with the base map with overlay model,the data center does not need to temporarily overlay incremental data with RMOM,so time-consuming of response is significantly reduced.RMOM greatly improves the efficiency of response and provides strong support for the real-time situation of navigational road network. 展开更多
关键词 spatio-temporal data model reverse map with overlay model road network incremental updating vehicle navigation system data center vehicle terminal
在线阅读 下载PDF
Effect of FDI on China's environmental pollution: Evidence based on spatial panel data 被引量:1
20
作者 ZHENG Yue-ming 《Ecological Economy》 2018年第2期141-146,共6页
It is clearly stated in the 19th people's congress that we should make the environmental protection as our national policy. Therefore, it is of great importance to study this issue. This article is going to consid... It is clearly stated in the 19th people's congress that we should make the environmental protection as our national policy. Therefore, it is of great importance to study this issue. This article is going to consider 30 provinces of China as the cross-section, and utilize the data sample from 2006 to 2015 of these cross-sections to formulate a Spatial Panel Data Durbin Model to analyze the effect of FDI. By using these data, this article creates a comprehensive environmental pollution index with the help of entropy. The result indicates that the effect of FDI on environment has a non-linear and spatial spillover characteristic. Before reaching the critical value, FDI has a negative effect on environment; however, with the accumulation of FDI, it will create a significant positive effect on the environment. 展开更多
关键词 fdi environmental pollution spatial panel data Durbin model
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部