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1.
KDD在高校教育中的应用   总被引:1,自引:0,他引:1  
以KDD(KnowledgeDiscoveryinDatabase,数据库中的知识发现)理论为基础,深入剖析当前高校教育技术信息化、网络化的状况,介绍了KDD技术发展状况以及数据挖掘在高校教育中的具体应用,归纳总结了KDD技术在现代教学过程中的应用空间及功能,并提出一些思考。  相似文献   

2.
基于数据库和知识库的知识发现研究综述   总被引:9,自引:0,他引:9  
介绍了知识发现技术的总体研究情况,包括KDD的定义、若干基本概念、主要过程和步骤、KDD的分类和主要技术手段、发展趋势以及KDD的主要应用领域.同时也指出了数据挖掘研究的挑战性以及目前的局限性,结合一些新的研究成果,探讨了基于知识库的知识发现(KDK)和数据库-知识库协同知识发现(KDD&K)的理论框架.  相似文献   

3.
一种新型的基于多智能体的KDD系统结构   总被引:2,自引:0,他引:2  
介绍了数据库中的知识发现(knowledge discovery in database,KDD)及数据挖掘(data mining,DM)研究领域的发展现状,分析了现有DM算法的局限性和KDD过程的复杂性,针对这些,进一步分析了多智能体系统(multi-agent system)可能给KDD系统带来的改善,最后设计了一种分层的,以控制Agent为核心的基于多智能体技术的KDD系统结构。  相似文献   

4.
对入侵检测评测样本库的生成方法进行了介绍,给出了KDD CUP’99数据集的样本分布,探讨了httptunnel攻击在KDD CUP’99数据集中的分类情况,通过分析KDD CUP’99数据集的特征属性与SNORT特征项的关联,表明了KDD CUP’99数据集作为智能化入侵检测方法评测样本库是公正而合理的.  相似文献   

5.
数据清理是KDD的首要步骤;没有好的数据环境,就不会有理想的挖掘结果.介绍了数据的一般特征,讨论了KDD中数据清理技术的清除空缺、噪声处理及不一致数据等问题,指出通用性和自适应性差是目前数据清理工具存在的主要问题.  相似文献   

6.
数据清理是KDD的首要步骤;没有好的数据环境,就不会有理想的挖掘结果.介绍了数据的一般特征,讨论了KDD中数据清理技术的清除空缺、噪声处理及不一致数据等问题,指出通用性和自适应性差是目前数据清理工具存在的主要问题.  相似文献   

7.
本文首先介绍了遗传算法的基本原理和KDD99数据集,而后运用遗传算法,PSO算法以及QPSO算法分别对小波神经网络进行优化构建各自的模型,最后通过在KDD99数据集上分别进行各个模型的仿真实验,得出QPSO进化算法的效果明显优于另外两种算法。  相似文献   

8.
在"KDD中双库协同机制的研究(Ⅰ)"的理论基础上,实现了对知识库的简约并实现了双库协同机制的两个协调器,从而建立了由KDD融入双库协同机制的新结构模型--KDD*,这是一个在结构和功能上相对于KDD而言的开放的、优化的扩体。基于双库协同机制与KDD*,提出了挖掘关联规则和聚类规则的新算法,充分体现了内在机理研究对主流发展的影响,开辟了一条全新的研究方向与路径。  相似文献   

9.
基于认知心理特征的协调器及相应KDD过程模型   总被引:2,自引:0,他引:2  
为提高KDD自认知能力,首次提出了基于认知心理特征的启发协调器和维护协调器.讨论了其设计及相应的实现算法.为实现知识库的自聚焦和实时维护,引入了双库协同机制用于方向搜索和方向挖掘.建立了相应的过程模型KDD*,实验结果显示此过程模型改善了KDD的性能.  相似文献   

10.
粗集在KDD系统中的应用与研究   总被引:1,自引:0,他引:1  
论述了粗集方法性质及特点,提出了粗集方法在KDD系统中的应用模型,同时给出了应用这一模型对一个数据库实例进行数据挖掘的过程.另外,从精确性、鲁棒性等方面对KDD系统中的粗集方法的适用范围进行了分析.  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   

17.
18.
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.
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