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1.
基于AJAX和VML的实时监测系统   总被引:1,自引:0,他引:1  
介绍了AJAX的基本原理和VML的功能,并给出了使AJAX和VML相结合来实现web实时监测的服务器及客户端程序的实现方法。这种方法不仅可以减轻服务器的负担而且可以节省网络带宽,是基于web方式进行实时数据监测方法中一种高效而简便的方法。  相似文献   

2.
基于VML和AJAX绘制站点的实况曲线图   总被引:1,自引:0,他引:1  
介绍了一个基于VML结合AJAX实现站点风向风速的绘制,阐述了基于VML开发图表程序的的一般思路和方法。  相似文献   

3.
为解决大田作物生长信息获取难的问题,设计开发了一个大田作物生长监测系统.该系统采用B/S与C/S相结合的体系结构,通过综合运用ActiveMQ消息服务器、AJAX等技术,实现了大田作物生长信息的定时采集、实时采集、多视图展示、动态功能部署等功能.实验结果表明,该系统功能完备,稳定性、可操作性强,完全满足进行大田作物长势信息采集的各项要求.  相似文献   

4.
梁民 《科技资讯》2007,(9):66-67
本文介绍了AJAX技术,及其包括的主要子技术,AJAX技术相对于传统web技术的优点,并对AJAX作了简单的应用示例。  相似文献   

5.
AJAX技术及其WEB应用   总被引:1,自引:0,他引:1  
徐蕊  王戈 《甘肃科技》2007,23(4):76-77
文章介绍了AJAX(Asynchronous JavaScript XML)技术的定义、实现原理与机制并介绍了AJAX的web应用。  相似文献   

6.
本文通过对AJAX基本概念、相关技术和工作原来的介绍,详细阐明了如何通过利用AJAX的异步数据交换功能来改善用户的web交互体验,并结合实例展示了AJ4X在实际开发中的应用.  相似文献   

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通过AJAX技术在社区系统的具体应用,阐明了AJAX技术在Web异步交互方面的优越性。在用户和服务器之间引入一个AJAX引擎,可以消除Web应用的开始一停止一开始一停止的交互过程.使用委托和门面模式相结合的复合模式,隐藏了服务器端逻辑的具体实现,降低了因页面直接访问服务器逻辑而引发安全问题的可能性.对基于AJAX模式下开发Web应用具有一定的实用价值.  相似文献   

9.
为了解决WEB服务器端数据与客户端数据及时间同步问题,避免客户端与服务器端频繁的数据交换,研究了在WEB中如何运用服务器推技术的问题,介绍了推技术实现原理和路径。基于Comet模型,开发了一个客户端通过AJAX长轮询、服务器端为纯粹servlet的实现服务器推技术的新技术。  相似文献   

10.
采用AJAX技术对Web1.0下开发的广西大学网络报修系统进行改造与移植,对原系统中采用表单输入方式的模块采用AJAX extender方式进行改造,对采用数据表直接进行输入的模块采用AJAX控件方式进行数据输入.经过改造与移植后的系统在易用性、参与性、高效性、用户体验等方面得到了全面的提升,杜绝了屏幕闪烁更新,提高了系统的反映速度,从而最大程度地减少了服务器的负载.系统改造达到了预期的目标,实现了Web2.0的应用要求.  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

15.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

16.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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