简介:Asystematic,efficientcompilationmethodforqueryevaluationofDeductiveDatabases(DeDB)isproposedinthispaper.Inordertoeliminateredundancyandtominimizethepotentiallyrelevantfacts,whicharetwokeyissuestotheefficiencyofaDeDB,thecompilationprocessisdecomposedintotwophases.Thefirstisthepre-compilationphase,whichisresponsiblefortheminimizationofthepotentiallyrelevantfacts.Thesecond,whichwerefertoasthegeneralcompilationphase,isresponsiblefortheeliminationofredundancy.Therule/goalgraphdevisedbyJ.D.Ullmanisappropriatelyextendedandusedasauniformformalism.Twogeneralalgorithmscorrespondingtothetwophasesrespectivelyaredescribedintuitivelyandformally.
简介:Aconceptualleveldatabaselanguagefortheentityrelationship(ER)modelimplicitlycontainsintegritiesbasictoERconceptsandspecialretrievalsemanticsforinheritancesofattributesandrelationships.Prolog,whichbelongstothelogicalandphysicallevel,cannotbeusedasafoundationtodirectlydefinethedatabaselanguage.ItisshownhowPrologcanbeenhancedtounderstandtheconceptsofentities,relationships,attributesandis-arelationships.TheenhancedPrologisthenusedasafoundationtodefinethesemanticsofadatabasequerylanguagefortheERmodel.Thethreebasicfunctionsofmodelspecification,updatesandretrievalsaredefined.
简介:Theconstructionofoceanographicontologiesisfundamentaltothe'digitalocean'.Therefore,onthebasisofintroductionofnewconceptofoceanographicontology,anoceanographicontology-basedspatialknowledgequery(OOBSKQ)methodwasproposedanddeveloped.Becausethemethodusesanaturallanguagetodescribequeryconditionsandthequeryresultishighlyintegratedknowledge,itcanprovideuserswithdirectanswerswhilehidingthecomplicatedcomputationandreasoningprocesses,andachievesintelligent,automaticoceanographicspatialinformationqueryonthelevelofknowledgeandsemantics.Acasestudyofresourceandenvironmentalapplicationinbayhasshowntheimplementationprocessofthemethodanditsfeasibilityandusefulness.
简介:Approximatequeryprocessinghasemergedasanapproachtodealingwiththehugedatavolumeandcomplexqueriesintheenvironmentofdatawarehouse.Inthispaper,wepresentanovelmethodthatprovidesapproximateanswerstoOLAPqueries.Ourmethodisbasedonbuildingacompressed(approximate)datacubebyaclusteringtechniqueandusingthiscompresseddatacubetoprovideanswerstoqueriesdirectly,soitimprovestheperformanceofthequeries.WealsoprovidethealgorithmoftheOLAPqueriesandtheconfidenceintervalsofqueryresults.AnextensiveexperimentalstudywiththeOLAPcouncilbenchmarkshowstheeffectivenessandscalabilityofourcluster-basedapproachcomparedtosampling.
简介:Inmanyapplicationsanddomains,temporalconstraintsbetweenactions,andtheirprobabilitiesplayanimportantrole.Weproposethefirstapproachintheliteraturecopingwithprobabilisticquantitativeconstraints.Toachievesuchachallenginggoal,weextendthewidelyusedsimpletemporalproblem(STP)frameworktoconsiderprobabilities.Specifically,weproposei)aformalrepresentationofprobabilisticquantitativeconstraints,ii)analgorithm,basedontheoperationsofintersectionandcomposition,forthepropagationofsuchtemporalconstraints,andiii)facilitiestosupportqueryansweringonasetofsuchconstraints.Asaresult,weprovideuserswiththefirsthomogeneousmethodsupportingthetreatment(representing,reasoning,andquerying)ofprobabilisticquantitativeconstraints,asrequiredbymanyapplicationsanddomains.
简介:用户声誉的研究对于互联网金融和电子商务的健康发展具有重要意义,是在线用户行为分析中一个重要的研究方向。在线用户评分系统中研究学者提出了许多声誉度量算法,然而不同方法度量用户声誉的思想和角度是不同的。为了在海量数据中对用户声誉有一个总体的认识,提出一种基于SkylineQuery的高声誉用户识别方法。将已有的几种声誉度量方法进行分类,综合选取代表性的算法得到的用户声誉用Skyline查询方法找到的集合Skyline中不被其他用户所支配的用户,即为高声誉用户。同时分析不同时间段上得到的集合Skyline中高声誉用户的规律。本文综合多种声誉度量方法从定性角度对声誉进行应用研究,拓宽了用户声誉研究的广度。
简介:AbstractObjective:Medical data mining and sharing is an important process in E-Health applications. However, because these data consist of a large amount of personal private information of patients, there is the risk of privacy disclosure when sharing and mining. Therefore, ensuring the security of medical big data in the process of publishing, sharing, and mining has become the focus of current research. The objective of our study is to design a framework based on a differential privacy protection mechanism to ensure the secure sharing of medical data. We developed a privacy protection query language (PQL) that integrates multiple data mining methods and provides a secure sharing function.Methods:This study is mainly performed in Xuzhou Medical University, China and designs three sub-modules: a parsing module, mining module, and noising module. Each module encapsulates different computing methods, such as a composite parser and a noise theory. In the PQL framework, we apply the differential privacy theory to the results of the computing between modules to guarantee the security of various mining algorithms. These computing devices operate independently, but the mining results depend on their cooperation. In addition, PQL is encapsulated in MNSSp3 that is a data mining and security sharing platform and the data comes from public data sets, such as UCBI. The public data set (NCBI database) was used as the experimental data, and the data collection time was January 2020.Results:We designed and developed a query language that provides functions for medical data mining, sharing, and privacy preservation. We theoretically proved the performance of the PQL framework. The experimental results show that the PQL framework can ensure the security of each mining result and the availability of the output results is above 97%.Conclusion:Our framework enables medical data providers to securely share health data or treatment data and develops a usable query language, based on a differential privacy mechanism, that enables researchers to mine information securely using data mining algorithms.
简介:一线性(q,,,m(n))局部地可译码的代码(LDC)C:\mathbbF{\mathbbF}n\mathbbF{\mathbbF}m(n)是从向量空间\mathbbF的线性转变{\mathbbF}n到空间\mathbbF{\mathbbF}每消息标志xi能与概率为被恢复的m(n)至少\frac1|\mathbbF|+e\frac{1}{{\left|\mathbb{F}\right|}}从由查询仅仅q的一个使随机化的算法的C(x)的+\varepsilonC放(x),就算直到C的m(n)位置(x)被贿赂。在Dvir的一个最近的工作,为线性LDC降低界限的作者表演能为算术电路暗示更低的界限。他建议那证明界限更低因为在建筑群或真实的地上的LDC是为接近他的之一的一个好起点推测。我们的主要结果是m(n)=(n2)为在任何东西上的线性3质问LDC的更低的界限,可能无限,地。常数在(