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1.
基于规则的个性化服务技术具有简单、直接等优点,但及时更新规则库比较困难。将基于规则树的增量式规则获取方法应用于个性化服务技术中,在保证规则质量前提下,大大缩短了学习时所用时间,能及时更新规则库。通过实验验证了该方法是可行的有效的。  相似文献   

2.
阐述了图书馆个性化信息服务以及关联规则数据挖掘技术,介绍了基于Apriori算法的数据挖掘实例。  相似文献   

3.
从大量顾客在线购买历史记录中挖掘出有用的关联规则,是一种及时有效的向顾客推出个性化服务的重要技术.对网上书店的顾客在线购买行为进行挖掘分析,采用Apriori算法找到其中的关联规则,采用支持度过滤方法获取频繁的顾客购买行为模式,提出根据用户的兴趣度和规则的置信度产生相应的推荐候选集,实现网上书店的个性化推荐服务。  相似文献   

4.
从大量顾客在线购买历史记录中挖掘出有用的关联规则,是一种及时有效的向顾客推出个性化服务的重要技术.对网上书店的顾客在线购买行为进行挖掘分析,采用Apriori算法[1]找到其中的关联规则,采用支持度过滤方法获取频繁的顾客购买行为模式,提出根据用户的兴趣度和规则的置信度产生相应的推荐候选集,实现网上书店的个性化推荐服务.  相似文献   

5.
针对事务库发生变化后关联规则的更新问题,讨论了一种只对具有实用价值的关联规则更新其前件的方法.首先分析了关联规则各组件间的依赖关系及其不确定性,进而建立描述其中所蕴含不确定性知识的贝叶斯网模型(称为规则贝叶斯网),并提出了基于Gibbs采样的规则贝叶斯网近似推理算法,从而实现关联规则的更新.实验结果表明,作者提出的基于概率图模型的关联规则前件更新方法具有高效性和可行性.  相似文献   

6.
一种基于有向超图的规则库冗余及环路检测方法   总被引:1,自引:0,他引:1  
当规则库的规模随着知识的更新而不断增大,规则库的维护就变得日益重要.其中,规则库的冗余和环路是影响规则库效率的重要问题.针对含有复合规则的产生式规则库,提出了一种基于有向超图的规则库表达方法,定义了其邻接矩阵和可达矩阵并推导出可达矩阵的计算方法.在此基础上给出了基于可达矩阵的冗余和环路检测算法.与已有的基于有向超图的算法相比,新算法图更简洁,矩阵规模更小,从而检测效率得到提高.实例证明该算法是有效可行的.  相似文献   

7.
关联分析是一种非常有效的数据挖掘方法,它能帮助人们发现隐藏在大型数据集中的令人感兴趣的联系,在电子商务等应用领域取得了广泛的应用.但实际运用中,它仍存在着关联规则挖掘困难以及得到的静态结果不易及时反映情况变化等问题.为此,人们提出演化关联规则的概念,本文设计了一个基于演化规则集的推荐模型.实际测试表明:它可挖掘出有用的关联规则并及时反映情况的变化,为客户提供更到位的个性化推荐服务,具有简单和计算效率高等特点.  相似文献   

8.
一种基于模糊C均值聚类的模糊规则提取方法   总被引:1,自引:2,他引:1  
提出了一种基于模糊C均值聚类的模糊规则提取方法,给出了模糊系统的模糊规则库,基于此规则库,构造了一种新颖的分类算法,利用IRIS数据进行了测试,仿真结果表明,分类效果好,由此说明所提出的模糊规则生成方法有效。  相似文献   

9.
snort规则语法在基于CVE特征的入侵检测系统中的应用   总被引:1,自引:0,他引:1  
黄昆 《应用科技》2004,31(6):41-43
针对人侵检测专家系统的不足,通过对CVE标准漏洞列表进行深人的研究,采用新型规则结构及snort规则描述语法,建立基于CVE特征的人侵检测专家系统规则库,它具有结构简洁、易于更新的特点.另外,以CVE标准为建立人侵检测专家系统规则库的基准,使得人侵检测专家系统规则库升级有了可靠的国际权威标准可以依据,对人侵检测系统的标准化有推动作用.  相似文献   

10.
个性化借阅数据挖掘和推荐为提高图书馆服务的有效性和智能性提供了可能,将关联规则技术应用到个性化借阅服务中,通过对以往借阅信息的挖掘以产生借阅书目的关联规则来实现个性化信息推荐服务。同时,图书类别关联规则的发现,对于图书购买、图书排架和图书推荐都具有深刻意义。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
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   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
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   

18.
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   

19.
20.
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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