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DNA存储场景下基于引物索引矩阵的文件高效随机检索方法
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作者 张淑芳 李予辉 李炳志 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第6期2568-2577,共10页
DNA分子具有密度高和稳定性的优势,有望成为下一代海量数据存储需求的介质,近年来受到广泛关注。目前将引物作为文件的唯一标识,基于聚合酶链式反应(PCR)扩增技术可实现对DNA池存储文件的随机检索,但对引物与文件之间的分配和映射关系... DNA分子具有密度高和稳定性的优势,有望成为下一代海量数据存储需求的介质,近年来受到广泛关注。目前将引物作为文件的唯一标识,基于聚合酶链式反应(PCR)扩增技术可实现对DNA池存储文件的随机检索,但对引物与文件之间的分配和映射关系没有进行深入研究,仍然采用随机分配的方式来关联引物与文件,这会导致目标引物序列的查找效率降低,且保存引物与文件的映射关系表会造成大量的数据冗余。为了提供一种高效的硅基计算设备与碳基存储系统的连接桥梁,有效降低存储引物与文件映射关系所带来的数据冗余,该文提出一种基于引物索引矩阵的DNA存储随机检索方法。该方法通过将存储文件集按照文件的不同属性进行划分来构建引物索引矩阵,同时将引物库中的引物按照转换规则转化为有序引物库,最后优化引物与文件之间的映射关系,以实现对文件的高效、多维度检索。实验结果表明,在存储不同规模的文件集时,运用所提算法建立对应的引物索引矩阵,可将引物检索效率提高为常数级时间复杂度,并且存储引物与文件的映射关系所需要的额外存储空间从原来的线性增长优化为对数增长。 展开更多
关键词 DNA存储 随机检索 引物索引矩阵
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水文数据库随机检索实用模型
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作者 刘永华 孙亚飞 《水文》 CSCD 北大核心 2003年第3期52-54,共3页
随机检索是水文数据库重要的检索功能之一,由于检索要求的不确定性给软件开发带来一定的困难。以数据库SQL语言为基础,通过对语言的简化和提示性的模式化操作,建立了一种实用的随机检索模型。
关键词 水文数据库 随机检索 模型
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水文数据库随机检索实用方法
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作者 刘永华 孙亚飞 《人民珠江》 2003年第5期30-31,共2页
随机检索是水文数据库重要的检索功能之一,由于检索要求的不确定性给软件开发带来一定的困难。介绍以数据库SQL语言为基础,通过对语言的简化和提示性的模式化操作,探讨一种实用的随机检索方法。
关键词 水文数据库 随机检索 SQL语言 数据库管理系统
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面向用户的随机检索设计及对SQL功能扩充
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作者 肖慎勇 《电脑开发与应用》 2000年第12期16-17,48,共3页
分析了基于关系数据库 MIS中对信息进行检索的特点 ,对面向最终用户的通用随机检索程序的目标、设计思想、步骤进行了说明 ,重点探讨了程序的数据库结构规范、数据接口以及程序中实现的对
关键词 随机检索 设计 SQL 功能扩充 信息检索 DBMS 管理信息系统 数据库 数据检索
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病案管理信息系统中的用户随机检索设计
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作者 肖慎勇 《湖北中医学院学报》 2000年第2期63-64,共2页
关键词 病案管理信息系统 用户随机检索设计
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提高高校图书馆期刊利用率的对策 被引量:5
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作者 罗碧文 《嘉应学院学报》 2005年第4期128-128,共1页
关键词 高校图书馆 期刊 利用率 文献检索 用户教育 知识发展 课程建设 教学内容 教学质量 随机检索
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一种快速的随机分块文本检索算法
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作者 赵亚慧 刘金广 崔荣一 《武汉理工大学学报》 CAS CSCD 北大核心 2010年第23期135-139,共5页
针对向量空间模型(VSM)在信息检索中存在脱离上下文语境的缺陷,提出一种新的随机分块文本检索算法。该算法利用潜在语义分析技术在低维空间中对检索文本与待检索文本的各个段落进行投影,使用SVD技术对其进行了降维处理,得到文本特征,然... 针对向量空间模型(VSM)在信息检索中存在脱离上下文语境的缺陷,提出一种新的随机分块文本检索算法。该算法利用潜在语义分析技术在低维空间中对检索文本与待检索文本的各个段落进行投影,使用SVD技术对其进行了降维处理,得到文本特征,然后依据该文本特征进行相似的匹配,获得检索结果。由于充分考虑了文本的上下文语义信息,算法能够有效提高检索效率。实验结果表明,该算法在检索时间、查准率、召回率及综合性能等方面均得到较好的效果。 展开更多
关键词 随机分块检索算法 向量空间模型 SVD技术 文本相似度
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计算机与学校管理
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作者 朱凯 《中小学管理》 北大核心 1989年第5期36-37,共2页
计算机问世仅四十多年,就以它蓬勃的生命力飞速发展起来。随着电子技术的进步,它已更新了四代,功能越来越强,体积越来越小,价格越来越便宜。因此不断深入各个应用领域,发挥着越来越显著的作用。由于它能自动地、高速地处理数据,
关键词 学校管理 应用领域 教师管理 学校行政管理 汉字输入 办公室工作人员 成绩统计 行政管理人员 随机检索 成绩通知单
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B^+树索引文件组织
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作者 王慧敏 《现代图书情报技术》 1984年第2期14-17,共4页
关键词 查找关键字 索引文件组织 B^+树 叶节点 随机检索 父节点 溢出区 索引顺序文件 直接地址 根节点
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市民遭“呼死你” 商家勒索200元
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作者 张雅 《广西质量监督导报》 2018年第3期19-21,共3页
商家向被骚扰者索要200元解除费"呼死你"软件,日渐成为部分不法分子敛财的手段。近日,贵阳市民夏先生的手机,就在1h内被上百通电话呼入。骚扰之后,对方发来信息称"只是求财",索要200元解除费用。无奈,做生意的夏先生只得把钱打给对... 商家向被骚扰者索要200元解除费"呼死你"软件,日渐成为部分不法分子敛财的手段。近日,贵阳市民夏先生的手机,就在1h内被上百通电话呼入。骚扰之后,对方发来信息称"只是求财",索要200元解除费用。无奈,做生意的夏先生只得把钱打给对方免受骚扰。2月5日,北京青年报记者调查发现,部分提供"呼死你"服务的卖家,已形成敛财"套路":通过网上随机检索到的经商者电话,使用软件进行骚扰。 展开更多
关键词 市民 商家 随机检索 骚扰 软件 电话 信息
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省级森林资源统计实现微机化
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作者 郝铭 曲轶莉 《林业勘查设计》 1989年第2期86-86,共1页
今年,黑龙江省森林资源调查管理局在完成1983年森林资源统计工作中,应用T.S.C型(IBM机兼容)微机,利用DABSEⅢ语言设计出3个模块,142个子程序,从而实现了林业局、林管局、森工总局54个单位森林资源消长动态统计微机化。过去需要三个人一... 今年,黑龙江省森林资源调查管理局在完成1983年森林资源统计工作中,应用T.S.C型(IBM机兼容)微机,利用DABSEⅢ语言设计出3个模块,142个子程序,从而实现了林业局、林管局、森工总局54个单位森林资源消长动态统计微机化。过去需要三个人一个多月时间手工完成的省级统计表中124项数字的核检、汇总工作,微机只需十四分半钟就可完成。而且,得到打印成果。运行表明,森林资源统计程序设计的三个模块,均能独立运算,很好的解决了统计表各栏目间的相互联系。 展开更多
关键词 森林资源 资源统计 微机化 汇总工作 森工 统计工作 统计程序 消长动态 数字的 随机检索
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浅谈如何应用微机加强财务制度管理
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作者 李进 郭翠英 《华北电业》 1997年第S1期35-38,共4页
关键词 财务制度 组合查询 WINDOWS 会计工作 信息传输器 索引码 随机检索 微机 工作站 解释器
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Effect of telehealth interventions on major cardiovascular outcomes: a metaanalysis of randomized controlled trials 被引量:3
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作者 Xiang GU Ye ZHU +8 位作者 Yi ZHANG Lei SUN Zheng-Yu BAO Jian-Hua SHEN Fu-Kun CHEN Hong-Xiao LI Shu-Hang MIAO Jing-Wu WANG Qing-Qing SHI 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2017年第8期501-508,共8页
Background Telehealth interventions (THI) were associated with lower levels of cardiovascular risk factors in adults, whereas the effect of THI on cardiovascular disease (CVD) still remains controversial. A meta-a... Background Telehealth interventions (THI) were associated with lower levels of cardiovascular risk factors in adults, whereas the effect of THI on cardiovascular disease (CVD) still remains controversial. A meta-analysis was conducted to summarize the evidence from randomized controlled trials (RCT) which investigated potential impact of THI on the incidence of CVD in patients with or without prior CVD. Methods PubMed, EmBase, and the Cochrane Library were searched to identify RCTs to fit our analysis through December 2016. Relative risk (RR) with its 95% confidence interval (CI) was used to measure the effect of THI using a random-effect model. Sensitivity analysis, subgroup analysis, heterogeneity tests, and tests for publication bias were also conducted. Results Eight RCTs were included and with a total of 1635 individuals. The summarized results indicated that participants who received THI showed a significant reduction of the CVD incidence as compared with usual care (RR: 0.59; 95% CI: 0.47-0.74; P 〈 0.001). Furthermore, the effect of THI was greater in patients with history ofCVD (RR: 0.55; 95% CI: 0.44-0.70; P 〈 0.001) than in patients without history ofCVD (RR: 0.99; 95% CI: 0.51-1.94; P = 0.977). Sensitivity analysis suggested that the intervention effect persisted and the conclusion was not changed. Subgroup analysis indi- cated mean age, study quality might play an important role on the risk of CVD. Conclusions The findings of this study indicated THI could reduce the recurrence of CVD. Further large-scale trials are needed to verify the effect of THI on CVD in healthy individuals. 展开更多
关键词 Cardiovascular disease META-ANALYSIS Telehealth interventions
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Three initial diets for management of mild acute pancreatitis:A meta-analysis 被引量:2
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作者 Wen-Bo Meng Xun Li +2 位作者 Yu-Min Li Wen-Ce Zhou Xiao-Liang Zhu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第37期4235-4241,共7页
AIM:To compare non-liquid and clear-liquid diets,and to assess whether the latter is the optimal treatment for mild acute pancreatitis.METHODS:The Cochrane Library,PUBMED,EMBASE,EBM review databases,Science Citation I... AIM:To compare non-liquid and clear-liquid diets,and to assess whether the latter is the optimal treatment for mild acute pancreatitis.METHODS:The Cochrane Library,PUBMED,EMBASE,EBM review databases,Science Citation Index Expanded,and several Chinese databases were searched up to March 2011.Randomized controlled trials(RCTs) that compared non-liquid with clear-liquid diets in patients with mild acute pancreatitis were included.A meta-analysis was performed using available evidence from RCTs.RESULTS:Three RCTs of adequate quality involving a total of 362 participants were included in the final analysis.Compared to liquid diet,non-liquid diet significantly decreased the length of hospitalization [mean difference(MD):1.18,95% CI:0.82-1.55;P﹤0.00001] and total length of hospitalization(MD:1.31,95% CI:0.45-2.17;P = 0.003).The subgroup analysis showed solid diet was more favorable than clear liquid diet in the length of hospitalization,with a pooled MD being-1.05(95% CI:-1.43 to-0.66;P﹤0.00001).However,compared with clear liquid diet,both soft and solid diets did not show any significant differences for recurrence of pain after re-feeding,either alone [relative risk(RR):0.95;95% CI:0.51-1.87;P = 0.88] and(RR:1.22;95% CI:0.69-2.16;P = 0.49),respectively,or analyzed together as non-liquid diet(RR:0.80;95% CI:0.47-1.36;P = 0.41).CONCLUSION:The non-liquid soft or solid diet did not increase pain recurrence after re-feeding,compared with the clear-liquid diet.The non-liquid diet reduced hospitalization. 展开更多
关键词 Acute pancreatitis DIET Nutritious supplement META-ANALYSIS Length of stay
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JOINT RANDOM OPTIMIZED THREE-STEP SEARCH ALGORITHM BASED-ON GRAY AND CHROMATIC INFORMATION
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作者 Liu Zhixin Liu Tieyan Zhang Xudong(Dept. of Electronic Engineering, Tsinghua University, Beijing 100084) 《Journal of Electronics(China)》 2002年第2期215-217,共3页
In this letter, an improved three-step search algorithm is presented, which uses both gray and chromatic information to boost the performance with random optimization and converge the motion vectors to global optima. ... In this letter, an improved three-step search algorithm is presented, which uses both gray and chromatic information to boost the performance with random optimization and converge the motion vectors to global optima. Experimental results show that this algorithm can efficiently improve the PSNR after motion compensation. 展开更多
关键词 Motion estimation Random optimization Three-step search
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Convergence rate of kernel canonical correlation analysis 被引量:5
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作者 CAI Jia SUN HongWei 《Science China Mathematics》 SCIE 2011年第10期2161-2170,共10页
Kernel canonical correlation analysis(CCA) is a nonlinear extension of CCA,which aims at extract-ing the information shared by two random variables. It has wide applications in many fields,such as information retrieva... Kernel canonical correlation analysis(CCA) is a nonlinear extension of CCA,which aims at extract-ing the information shared by two random variables. It has wide applications in many fields,such as information retrieval. This paper gives the convergence rate analysis of kernel CCA under some approximation conditions and some suggestions on how to choose the regularization parameter. The result shows that the convergence rate only depends on two parameters:the rate of regularization parameter and the decay rate of eigenvalues of compact operator VY X,and it gives better understanding of kernel CCA. 展开更多
关键词 covariance operator canonical correlation analysis RKHS
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Meta analysis of the curative effect of acupuncture on post-stroke depression 被引量:20
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作者 张光彩 符文彬 +5 位作者 许能贵 刘健华 朱晓平 梁兆辉 黄叶飞 陈远芳 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2012年第1期6-11,共6页
OBJECTIVE:To systematically evaluate the curative effect of acupuncture on post-stroke depression(PSD).METHODS:The internet was used to retrieve the Wanfang Medical Data System,Chinese Periodical Net,the Weipu Informa... OBJECTIVE:To systematically evaluate the curative effect of acupuncture on post-stroke depression(PSD).METHODS:The internet was used to retrieve the Wanfang Medical Data System,Chinese Periodical Net,the Weipu Information Resources System,PubMed and the Cochrane Library Database.Relevant articles,up to September 2010,were manually retrieved.These papers included studies that had performed random and semi-random control trials for the use of acupuncture to treat PSD.Fifteen random control tests involving 1096 patients were included in this study and individual cases,interventional measures and curative effects were extracted from this research.Grade methodological quality evaluation and meta-analysis were performed on these studies.RESULTS:Comparison between the acupuncture group and the Western medicine group for the curative rate on PSD revealed an OR of 1.48,95% CI = [1.11 1.97] and P=0.008.Comparison of obviously effective rate shows that OR=1.39,95% CI=[1.08 1.80] and P=0.01.Comparison of effective rate showsthatOR=0.83,95%CI=[0.631.09]andP=0.18.CONCLUSION:Comparison between the acupuncture group and Western medicine group in treating PSD revealed that there is a statistical difference in curative rate and remarkably effective rate,but no difference in effective rate. 展开更多
关键词 Post-stroke depression ACUPUNCTURE Random control test Meta analysis.
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Calcium dobesilate for diabetic retinopathy: a systematic review and meta-analysis 被引量:55
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作者 ZHANG XinYuan LIU Wei +3 位作者 WU ShanShan JIN JingLong LI WeiHong Wang NingLi 《Science China(Life Sciences)》 SCIE CAS CSCD 2015年第1期101-107,共7页
Many randomized clinical controlled trials have confirmed the efficacy and safety of calcium dobesilate in treating diabetic retinopathy(DR).This systematic review critically evaluated the evidence that links calcium ... Many randomized clinical controlled trials have confirmed the efficacy and safety of calcium dobesilate in treating diabetic retinopathy(DR).This systematic review critically evaluated the evidence that links calcium dobesilate to DR.In this fixed-effects meta-analysis,a total of 221 pertinent English-language articles published between January 1975 and October 2013 were identified.Systematic searches of PUBMED,Springer Link and the Cochrane Clinical Trials Database were conducted using the keywords "diabetic retinopathy" and "calcium dobesilate".The extracted information included the study design,inclusion and exclusion criteria,setting,sample size,participant mean age,treatment regime,mean change in best corrected visual acuity,laboratory parameters,capillary fragility,intraocular pressure and fundus manifestations based on the findings of fluorescent angiography.The summary statistics indicated that calcium dobesilate was significantly associated with improving retinal microaneurysms(RR: 0.62,95%CI: 0.42?0.90,P=0.01),retinalhemorrhages(RR: 0.39,95% CI: 0.17?0.88,P=0.02); exudates(RR: 0.31,95% CI: 0.12?0.81,P=0.02),reduction of whole blood viscosity(MD: ?0.57 CP,95% CI: ?0.75 to ?0.38,P<0.001),plasma viscosity(MD: ?0.36 CP,95% CI: ?0.63 to ?0.09,P=0.01) and blood cholesterol(MD: ?0.48 mg m L?1,95% CI: ?0.64?0.33,P<0.00001).Intraocular pressure was also significantly reduced(MD: ?5.59 mm Hg,95% CI: ?6.69 to ?4.50,P<0.00001).The results indicate that calcium dobesilate effectively treats DR at the systematic and local ocular levels. 展开更多
关键词 diabetic retinopathy calcium dobesilate randomized controlled clinical trial systemic review META-ANALYSIS
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