排序方式： 共有75条查询结果，搜索用时 265 毫秒
31.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｉｓｐａｐｅｒｃｏｎｓｉｄｅｒｓｔｈｅｍｉｘｅｄ ｅｆｆｅｃｔｃｏｅｆｆｉ ｃｉｅｎｔｓｅｍｉｐａｒａｍｅｔｒｉｃｒｅｇｒｅｓｓｉｏｎｍｏｄｅｌＺ =Ｘ′α Ｙ′β ｇ(Ｔ) ｅ,(1 )ｗｈｅｒｅＸ ,ＹａｎｄＴａｒｅｒａｎｄｏｍｖｅｃｔｏｒｓｏｎＲｐ,Ｒｑａｎｄ [0 ,1 ]ｒｅｓｐｅｃｔｉｖｅｌｙ ,αｉｓａｐ ｄｉｍｅｎｓｉｏｎａｌｆｉｘｅｄ ｅｆｆｅｃｔｐａｒａｍｅｔｅｒ,βｉｓａｑ ｄｉｍｅｎｓｉｏｎａｌｒａｎ ｄｏｍ ｅｆｆｅｃｔｐａｒａｍｅｔｅｒ (Ｅβ =ｂ ,Ｃｏｖ(β) =∑) ,ｇ(.)ｉ… 相似文献
32.
姜密 《河北师范大学学报(哲学社会科学版)》2008,31(1):112-117
由唐至宋,国有土地制度发生了很大变化,尤显于"系官田产"的产权变动,不管是从私有转为国有,还是由国有转为私有,附着在田产之上的"亲邻关系"都不可避免地会发生变化,其变化呈淡化趋势。 相似文献
33.
胡煜 《广东技术师范学院学报》2008,(6)
本文主要采用两种降维的方法和k-近邻法(KNN)有监督分类的方法来对基因芯片(微阵列)数据进行分析。PCA,PLS是一种提取海量的数据有效特征的有效方法,可以获得与原来基因芯片数据更为接近的成分的提取特征的效果。比较PCA降维方法和PLS降维方法对KNN统计判别分类的效果。 相似文献
34.
基于自然邻点插值的数据处理方法 总被引：1，自引：0，他引：1
利用自然邻点方法对离散的中国大陆地区大地热流观测数据和相对均匀的台湾地区重力观测数据进行了插值计算 ,并与地学中几种常用插值方法进行了比较 .结果表明 :自然邻点插值方法更适于处理分布不规则的观测数据 . 相似文献
35.
Most of the Peer-to-Peer search techniques proposed in the recent years have focused on the single-key retrieval. However, similarity search in metric spaces represents an important paradigm for content-based retrieval in many applications. In this paper we introduce an extension of the well-known Content-Addressable Network paradigm to support storage and retrieval of more generic metric space objects. In particular we address the problem of executing the nearest neighbors queries, and propose three different algorithms of query execution. An extensive experimental study on real-life data sets explores the performance characteristics of the proposed algorithms by showing their advantages and disadvantages. 相似文献
36.
A motion information analysis system based on the acceleration data is proposed in this paper,consisting of filtering,feature extraction and classification.The Kalman filter is adopted to eliminate the noise.With the time-domain and frequency-domain analysis,acceleration features like the amplitude,the period and the acceleration region values are obtained.Furthermore,the accuracy of the motion classification is improved by using the k-nearest neighbor （KNN） algorithm. 相似文献
37.
作为后开发地区,社会经济发展战略的正确定位十分重要。把钦州作为“广西临海工业大港”营建的发展战略定位,具有十分重要的理论和实践意义。在发展战略实施过程中,还必须深入分析研究和把握住区域真正的区位特征,充分发挥区域性投入,克服邻近负效应的无序竞争,优化区域产业结构,最大限度地构筑和引发空间经济的共振作用,使钦州能在最短的时间内获得较快的发展。 相似文献
38.
为有效识别浮动验证码,提出一种基于特征匹配与卷积神经网络的识别方法。首先使用特征匹配的方法得到匹配特征点,结合交叉匹配算法与 K 近邻匹配算法滤除错误匹配;然后对特征点进行聚类及投票分析,得到待识别字符区域,将其分割得到单个字符;最后在 mnist 手写数字数据集的基础上加入英文字符,构建卷积神经网络模型,将数据集送入模型进行训练。对 10 000 张浮动验证码进行测试,结果表明,该方法对浮动验证码的识别准确率达 95%,且构建的训练集具有可扩展性,可进一步应用到其它类型的字符识别中。 相似文献
39.
Yong MAO Xin HUANG Ke YU Hai-bin QU Chang-xiao LIU Yi-yu CHENG 《Journal of Zhejiang University. Science. B》2008,9(6):474-481
Hepatitis B virus (HBV)-induced liver failure is an emergent liver disease leading to high mortality. The severity of liver failure may be reflected by the profile of some metabolites. This study assessed the potential of using metabolites as biomarkers for liver failure by identifying metabolites with good discriminative performance for its phenotype. The serum samples from 24 HBV-induced liver failure patients and 23 healthy volunteers were collected and analyzed by gas chromatography-mass spectrometry (GC-MS) to generate metabolite profiles. The 24 patients were further grouped into two classes according to the severity of liver failure. Twenty-five commensal peaks in all metabolite profiles were extracted, and the relative area values of these peaks were used as features for each sample. Three algorithms, F-test, k-nearest neighbor (KNN) and fuzzy support vector machine (FSVM) combined with exhaustive search (ES), were employed to identify a subset of metabolites (biomarkers) that best predict liver failure. Based on the achieved experimental dataset, 93.62% predictive accuracy by 6 features was selected with FSVM-ES and three key metabolites, glyceric acid, cis-aconitic acid and citric acid, are identified as potential diagnostic biomarkers. 相似文献
40.
PAN Peng LU Yan-sheng 《浙江大学学报(A卷英文版)》2007,8(4):529-537
The problem of continuously monitoring multiple K-nearest neighbor (K-NN) queries with dynamic object and query dataset is valuable for many location-based applications. A practical method is to partition the data space into grid cells, with both object and query table being indexed by this grid structure, while solving the problem by periodically joining cells of objects with queries having their influence regions intersecting the cells. In the worst case, all cells of objects will be accessed once. Object and query cache strategies are proposed to further reduce the I/O cost. With object cache strategy, queries remaining static in current processing cycle seldom need I/O cost, they can be returned quickly. The main I/O cost comes from moving queries, the query cache strategy is used to restrict their search-regions, which uses current results of queries in the main memory buffer. The queries can share not only the accessing of object pages, but also their influence regions. Theoretical analysis of the expected I/O cost is presented, with the I/O cost being about 40% that of the SEA-CNN method in the experiment results. 相似文献