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1.
防止敏感数据泄露是网络服务商面临的主要问题,随着网络的逐渐发展,该问题变得越来越复杂,传统数据防泄漏方法通常通过关键词搜索实现,虚警率高,整体性能低下。为此,提出一种新的arp攻击后网络数据防泄漏方法,通过动态指纹检测对arp攻击后存在网络隐患的敏感数据进行初步检测,通过概率检测降低计算开销和内存。针对指纹比对,在随机选择的一组整数上对字符串进行检测,将检测点和Bloom滤波器关联,给出通过概率检测进行网络数据泄露检测的详细过程,从而防止arp攻击后网络数据泄露。实验结果表明,所提方法不仅精度高,而且整体性能强。  相似文献   

2.
关于指数分布无失效数据的一种Bayes分析   总被引:1,自引:0,他引:1  
对指数分布无失效数据给出了一种新的处理方法:用Bayes方法寻求指数分布情况下的拟累积失效数的估计,从而获得无失效情况下未知参数的修正极大似然估计.  相似文献   

3.
曹明艳 《工程与建设》2005,19(3):198-199
文章从设计和施工角度分析了产生楼层局部渗漏的原因,针对产生渗漏的原因,从施工材料的选用、施工工艺及施工管理等方面论述了防止楼层局部渗漏所采取的一系列措施。  相似文献   

4.
Microarray technology has been widely used to analyze the gene expression levels by detecting fluorescence intensity in a high throughput fashion. However, since the measurement error produced from various sources in microarray experiments is heterogeneous and too large to be ignored, we propose here a measurement error model for microarray data processing, by which the standard deviation of the measurement error is demonstrated to be linearly increased with fluorescence intensity. A robust algorithm, which estimates the parameters of the measurement error model from a single microarray without replicated spots, is provided. The model and algorithm for estimating of the parameters from a given data set are tested on both the real data set and the simulated data set, and the result has been proven satisfactory. And, combining the measurement error model with traditional Z-test method, a full statistical model has been developed. It can significantly improve the statistical inference for identifying differentially expressed genes.  相似文献   

5.
Most of spatial phenomena like natural vegetation units and land use areas constantly change over time and have uncertainty spatial extents. Till now,a considerable number of data models have been proposed for spatial objects with sharp boundaries as well as with indeterminate boundaries. However,they mainly concern space and time or space and fuzziness and not yet integrate them into a single unified framework. This paper introduces a formal definition of the conceptual fuzzy spatiotemporal data model,called FSTDM for fuzzy regions based on fuzzy set theory. We also contribute a method of manipulating queries with the presence of both temporal predicate and fuzzy spatial predicate in the condition clause efficiently. We then implement a prototype system. Through the experimental results,we prove that our work can be used to build a specialized system such as GIS,spatial database,and so on.  相似文献   

6.
Most of spatial phenomena like natural vegetation units and land use areas constantly change over time and have uncertainty spatial extents. Till now, a considerable number of data models have been proposed for spatial objects with sharp boundaries as well as with indeterminate boundaries. However, they mainly concern space and time or space and fuzziness and not yet integrate them into a single unified framework. This paper introduces a formal definition of the conceptual fuzzy spatiotemporal data model, called FSTDM for fuzzy regions based on fuzzy set theory. We also contribute a method of manipulating queries with the presence of both temporal predicate and fuzzy spatial predicate in the condition clause efficiently. We then implement a prototype system. Through the experimental results, we prove that our work can be used to build a specialized system such as GIS, spatial database, and so on.  相似文献   

7.
数据网格环境下的一种动态备份模型   总被引:5,自引:1,他引:4  
在常见的层次拓扑结构的数据网格环境中提出一种动态备份模型,实现了备份的自动创建、删除和更新,优化了备份的放置策略,并为用户数据访问自动选择文件或备份服务。  相似文献   

8.
Most of spatial phenomena like natural vegetation units and land use areas constantly change over time and have uncertainty spatial extents. Till now, a considerable number of data models have been proposed for spatial objects with sharp boundaries as well as with indeterminate boundaries. However, they mainly concern space and time or space and fuzziness and not yet integrate them into a single unified framework. This paper introduces a formal definition of the conceptual fuzzy spatiotemporal data model, called FSTDM for fuzzy regions based on fuzzy set theory. We also contribute a method of manipulating queries with the presence of both temporal predicate and fuzzy spatial predicate in the condition clause efficiently. We then implement a prototype system.Through the experimental results, we prove that our work can be used to build a specialized system such as GIS, spatial database, and so on.  相似文献   

9.
致密储层在体积压裂过程中由裂缝导致的漏失对压裂液能效利用和套管变形均有影响,不同类型裂缝的漏失所具有的特点差异显著,目前仍没有针对性的控制措施。本文首先明确了体积压裂裂缝(简称体积裂缝)的分类及性质,在总结体积裂缝漏失类型及特点的基础上,调研了各类漏失的应对方法及优缺点,分析了解决上述漏失问题的控制技术和封堵材料,并指出了体积裂缝漏失的发展方向。结果表明:体积裂缝漏失可分为水-岩相互作用导致的拉伸裂缝漏失、小井距体积压裂造成的裂缝串通漏失、天然裂缝/断层沟通导致的漏失三类;压裂中添加粉砂和压裂液体系离子调节能缓解拉伸裂缝导致的漏失,压裂参数优化与暂堵结合能使得裂缝转向,降低小井距裂缝串通漏失的频率,优化压裂选段或提前封堵天然裂缝/断层能降低压裂液在天然裂缝/断层中的漏失;压裂参数精细化、发展裂缝转向或能够形成自适应封堵的新型材料是未来发展的趋势。结论认为:在地质工程一体化框架下,针对体积裂缝的漏失类型采取对应的控制措施,以压裂参数优选协同自适应封堵材料的思路控制体积压裂裂缝漏失,为提高压裂液能效和预防套管变形提供技术支持。  相似文献   

10.
公路隧道防渗漏质量控制   总被引:9,自引:3,他引:9  
为控制公路隧道的渗漏,结合工程实践研究了公路隧道的防渗漏问题,提出防渗漏工作应贯穿于隧道施工全过程的思路。给出施工过程中防渗漏环节的质量控制方法,重点介绍CPE防水板、排水管、纵向排水盲沟的施工要点及高抗渗耐蚀二次衬砌混凝土的应用。研究结果表明,公路隧道的防渗漏工作,应该向前扩展至铺设防水层之前的开挖和初期支护阶段,向后延伸至二次衬砌阶段。  相似文献   

11.
主要讨论了古典风险模型余额首次返回零点前及最后一次返回零点前两种时期内的极小值和极大值的联合分布,并运用模型的强马氏性及平稳性解决了问题.  相似文献   

12.
The evolution of methane carbon isotope with depth has been discussed based on diagenetic reaction kinetics and isotopic Rayleigh fractionational theory. A mathematical model to describe data of methane carbon isotope for the Liaohe oil field has been established.  相似文献   

13.
面向制造系统的多级物流配送模型及算法   总被引:1,自引:1,他引:0  
针对制造系统供应链管理中多级配送运输存在的问题,采用仿真的方法进行模拟,设计一种合理算法,分析了供应链中物料沿着从最初的供应商流向其下游不同的生产商、装配商,完成整个制造形成产品的过程,揭示了生产商流向其下游批发商、零售商,最终到达用户手中实现其价值的规律.研究结果表明,这种多级配送模型和优化调度算法,对解决大规模配送决策问题具有可行性.  相似文献   

14.
给出了一种基于数据流的实时高速数据互连模型。该模型将模块间互连的地址和控制信号统一为一个与数据同步的信号,使得结构简单,互连接口相似,可以实现数据处理中常用的功能。基于该模型的模块容易扩展,重用性好,特别适用于高速实时处理。最后,通过一个200MSPS高速采集实时存储的例子具体说明了模型的应用。  相似文献   

15.
本文提出了一个全新的呼叫接入方案,以有效使用蜂窝技术和无线网络。这个方案为两种存取网络采取了不同的资源分配策略,根据不同的呼叫层级服务质量(QoS)需求,限制新的水平或垂直的用于信号切换的语音数据的呼叫到达。数值结果显示,与没有集成的网络模型相比,本方案更加有效,对语音数据用户而言满足所有达到最大值的QoS需求。  相似文献   

16.
运用多维数据模型实现数据集市   总被引:3,自引:0,他引:3  
文中阐述了数据集市、多维数据模型的基本概念和技术 ,探讨了一种用多维数据模型实现数据集市的方法。最后 ,给出了一个数据集市的应用实例  相似文献   

17.
0 IntroductionDue to the success of Internet technology and the emer-gence of wide band network,downloading encoded dig-ital audiovisual content files via HTTP,FTP,etc ,had gainedfavor amongInternet users because of thei mmediate access todesired content . Digital Right Management (DRM) system,can satisfy the content provider by encrypting digital audiovi-sual content andli miting access to onlythose people who haveacquired a proper license to play backthe content[1].DRMas defined bythe …  相似文献   

18.
探讨了规划数据仓库体系结构、建立分层的企业级数据模型以及采用分阶段建立模型等方法 ,解决目前数据仓库开发过程中的问题 .  相似文献   

19.
文章以随机规划中的机会约束思想为指导,根据随机参数的概率分布情况,提出了两种鲁棒性条件约束,并在此基础上建立了一种新的鲁棒优化模型,使模型的可行解控制在一定的鲁棒性指标的范围内。该模型不但可处理约束两端同时含有随机参数的情况,还可以方便地推广到非线性模型中。仿真实例说明了模型的有效性。  相似文献   

20.
多维数据模型是数据仓库和联机分析处理中的一个重要环节。文章提出了一种新的多维数据模型。在该模型中,基于维与事件的关系,描绘了多维事件关系图,并利用非奇异聚集偏序集簇定义了维的结构。结合小灵通客户流失问题,给出了该模型的具体的实现。  相似文献   

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