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1.
基于MIDAS的DAX网络发布技术在油田WebGIS中的应用研究   总被引:2,自引:0,他引:2  
提出了基于MIDAS的DAX网络发布技术在WebGIS中的设计方法。该方法是一个共享的中间层上封装了商业规则,集中的实现了应用服务器所要实现的功能,使客户程序将重点放在显示数据和与用户交互上,将这项技术应用于油田中的地质图绘制方面,解决了油田中多层分布构数据库的访问,管理和地质图件的动态生成问题,研制开发的“基于WebGIS地质图绘制软件包”在大庆油田推广使用。取得了良好的效果。  相似文献   

2.
针对WeBGIS的地理信息系统中信息分布于网络的异构节点中、开发难度大、开发出的系统不稳定等问题,提出基于移动Agellt的WebGIS中间件的开发,取得了良好的效果。实践表明,WebGIS中间件可以无缝地嵌入到Web主页,实现网络环境下的GIS应用系统,一方面降低了系统的复杂性,加快开发速度;另一方面也可以平衡网络负载,获得准确的地理信息,节省网络带宽。  相似文献   

3.
基于MapXtreme的WebGIS负载平衡服务器的设计与实现*   总被引:3,自引:1,他引:2  
针对动态生成和发布GIS图幅的WebGIS应用系统以及多用户并发访问问题,提出了一种基于负载平衡方法的解决方案。用户动态生成和发布GIS图幅过程需消耗大量的服务器系统资源,使服务器处于严重的瓶颈状态,设定一个专门的负载平衡服务器来管理多个GIS服务器。客户端在进行GIS请求时首先访问该服务器,负载平衡服务器检测每个GIS服务器是否是处于饱和状态,若有未饱和的GIS服务器则让请求客户端连接到此服务器上进行GIS图件服务,从而解决了多用户并发访问时的瓶颈问题。设计并实现了B/S模式的基于WebGIS的地质图幅  相似文献   

4.
轻量级WebGIS中间件的设计与实现   总被引:3,自引:0,他引:3       下载免费PDF全文
钱志彬  赵卫东 《计算机工程》2006,32(23):265-267
GIS中间件是实现多层分布式GIS应用的核心,能有效地提供各类空间信息服务,屏蔽不同空间数据源的差异性。该文以GIS中间件技术的研究为起点,提出了WebGIS中间件框架BSGIS,对BSGIS的体系结构和处理流程进行阐述,介绍了BSGIS的具体实现,并将其应用于政府道路管理系统之上,证明了该框架在实际应用中的可行性,解决了WebGIS开发复杂性高、成本大、成功率低等问题。  相似文献   

5.
针对WebGIS的地理信息系统中信息分布于网络的异构节点中、开发难度大、开发出的系统不稳定等问题,提出基于移动Agent的WebGIS中间件的开发,取得了良好的效果。实践表明,WebGIS中间件可以无缝地嵌入到Web主页,实现网络环境下的GIS应用系统,一方面降低了系统的复杂性,加快开发速度;另一方面也可以平衡网络负载,获得准确的地理信息,节省网络带宽。  相似文献   

6.
通过GIS数据库设计方法和特点,确定了油气井动态系统的数据管理体系结构与模块结构;同时基于MapXtreme为WebGIS开发平台,系统充分利用数据库信息处理技术、万维网地理信息系统(WebGIS)技术,实现图文信息共享,高效、便捷地动态生成油气井位图,同时可获取所需的地质相关资料,加速实现油田网络数字化建设。  相似文献   

7.
通过GIS数据库设计方法和特点,确定了油气井动态系统的数据管理体系结构与模块结构;同时基于MapXtreme为WebGIS开发平台,系统充分利用数据库信息处理技术、万维网地理信息系统(WebGIS)技术,实现图文信息共享,高效、便捷地动态生成油气井位图,同时可获取所需的地质相关资料,加速实现油田网络数字化建设。  相似文献   

8.
中间件技术研究   总被引:13,自引:4,他引:13  
中间件技术屏蔽了底层分布式环境的复杂性和异构性,简化了分布式应用程序的开发,使分布式应用程序的健壮性、可扩展性、可用性更好。介绍了面向对象中间件、面向消息中间件、面向大规模分布式系统中间件、服务质量中间件等当前各种中间件技术发展的现状,分析了中间件技术面临的挑战,提出了中间件技术研究的几个发展趋势,即网格技术、面向移动计算、面向服务质量等。  相似文献   

9.
中间件技术研究   总被引:17,自引:0,他引:17  
中间件技术屏蔽了底层分布式环境的复杂性和异构性,简化了分布式应用程序的开发,使分布式应用程序的健壮性、可扩展性、可用性更好。本文介绍了中间件的定义、分类、主流中间件技术平台,分析了中间件技术面临的挑战,提出了中间件技术研究的几个发展趋势,即网格技术、面向移动计算、面向服务质量等。  相似文献   

10.
中间件技术屏蔽了底层分布式环境的复杂性和异构性,简化了分布式应用程序的开发,使分布式应用程序的健壮性、可扩展性、可用性更好。本文介绍了中间件的定义、分类、主流中间件技术平台,能够隐藏底层网络环境的复杂性,处理平台之间的异构性,是分布式计算和系统集成的关键组件。本文介绍了中间件的基本概念,阐述了一种基于系统层次的分类方法,并详细讨论了现存各类中间件技术的特点、相关标准及发展应用情况。  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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