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1.
基于WebGIS的防汛信息系统   总被引:4,自引:0,他引:4  
分析了WebGlS的实现技术及特点,结合防汛信息系统的需求,给出了基于WebGIS的防汛信息系统的功能结构和体系结构。采用ⅡS作为Web服务器、ArcIMS作为地图服务器完成了系统功能设计,实现了网上数字地图的处理、传送,以及基于地图的防汛信息查询。  相似文献   

2.
基于FastCGI的分布式集群WebGIS研究*   总被引:1,自引:1,他引:0  
针对当前网络地理信息系统(WebGIS)中存在的效率问题和服务器端压力过大的问题,提出了基于FastCGI的多进程、分布式集群的WebGIS构建方案。详细介绍了该方案中服务器端地图服务器的体系结构、功能模块、工作流程以及集群部署实现。在此基础上实现了符合OGC标准规范的基于FastCGI分布式集群WebGIS平台,并进行了性能测试,同时在实际项目中对该方案进行了验证。结果表明,相比于当前其他模式的WebGIS,基于FastCGI多进程、分布式集群构建的WebGIS具有效率更高、可扩展性更强、稳定性更好的特  相似文献   

3.
基于COM的可复用数据对象的设计与实现   总被引:1,自引:0,他引:1  
夏坤  张建国  蒋洪 《计算机应用》2001,21(11):36-37
分析了COM对软件复用的支持,并针对两层客户/服务器结构的数据库应用系统,提出了一种有效的数据库访问方法,设计并实现了N层客户/服务器结构中基于COM的可复用数据库对象。  相似文献   

4.
对COM+基本结构及基于COM+组件的多层应用模型进行了分析,将COM+组件应用于某钢铁企业“整合型集团经销信息网络管理系统”中.初步实现了基于COM+组件技术的三层客户端/服务器结构的系统模型.从而提高了钢铁企业经销系统的性能。  相似文献   

5.
有效的WebGIS地图服务器场负载均衡算法   总被引:1,自引:1,他引:1       下载免费PDF全文
针对现有网络地理信息系统(WebGIS)负载均衡技术的缺陷,分析利用集群技术解决WebGIS负载均衡的必要性和可行性,提出基于地图服务器场的WebGIS分布式负载均衡模型,研究地图服务器场分布式动态均衡调度算法,建立试验床,通过一系列的试验结果验证了该算法良好的全局网络负载性。  相似文献   

6.
基于数字地球的WebGIS开发及其应用   总被引:4,自引:0,他引:4       下载免费PDF全文
空间地理数据的传输、处理以及展示对WebGIS提出了更高的要求。基于此,在开源数字地球模型上进行二次开发,采用GeoServer作为WebGIS服务器实现网络地图服务,构建一种金字塔模型的数据缓存机制,分析系统体系结构,设计基于数字地球的WebGIS。通过在WebGIS上水雨情信息综合集成和洪水淹没三维仿真的应用表明,该WebGIS具有较好的实用性和扩展性。  相似文献   

7.
在介绍组件对象模型(COM)基本思想的基础上,提出了基于组件对象模型的湿地WebGIS应用体系结构,并对湿地WebGIS系统的开发过程及相关实现技术做了详细的论述。  相似文献   

8.
针对WebGIS在税务系统应用中遇到的对地图数据要求动态更新和动态匹配的问题进行了分析,给出了纳税户到街道动态匹配的方法,结合分布式对象技术,对纳税户到街道动态匹配进行了分布式设计,探讨了设计中各分布式对象间的工作过程及相关的数据分配策略。  相似文献   

9.
利用Delphi构建分布式Web应用系统   总被引:4,自引:1,他引:4  
讨论了分布式Web应用系统构建的思想及关键技术,分析了Delphi对于开发分布式Web应用系统的强劲支持,说明了MTS/COM+技术与Web服务器的结合,并给出了使用Delphi技术开发分布式Web应用系统的方法。  相似文献   

10.
开放式多规约OPC通讯服务器研究与设计   总被引:1,自引:0,他引:1  
介绍了基于微软0LE/COM技术上的OPC规范及其应用的环境,并论述了OPC服务器的对象和接口,重点设计了一个用于变电站的开放式多规约OPC通讯服务器,此服务器具有数据处理和规约转换处理等功能。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.  相似文献   

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