Mutation (substitution, deletion, insertion, etc.) in nucleotide acid causes the maximal sequence lengths of exact match (MALE) between paralogous members from a duplicate event to become shorter during evolution. In ...Mutation (substitution, deletion, insertion, etc.) in nucleotide acid causes the maximal sequence lengths of exact match (MALE) between paralogous members from a duplicate event to become shorter during evolution. In this work, MALE changes between members of 26 gene families from four representative species (Arabidopsis thaliana, Oryza sativa, Mus mus- culus and Homo sapiens) were investigated. Comparative study of paralogous’ MALE and amino acid substitution rate (dA<0.5) indicated that a close relationship existed between them. The results suggested that MALE could be a sound evolutionary scale for the divergent time for paralogous genes during their early evolution. A reference table between MALE and divergent time for the four species was set up, which would be useful widely, for large-scale genome alignment and comparison. As an example, de- tection of large-scale duplication events of rice genome based on the table was illustrated.展开更多
Graph pattern matching(GPM)can be used to mine the key information in graphs.Exact GPM is one of the most commonly used methods among all the GPM-related methods,which aims to exactly find all subgraphs for a given qu...Graph pattern matching(GPM)can be used to mine the key information in graphs.Exact GPM is one of the most commonly used methods among all the GPM-related methods,which aims to exactly find all subgraphs for a given query graph in a data graph.The exact GPM has been widely used in biological data analyses,social network analyses and other fields.In this paper,the applications of the exact GPM were first introduced,and the research progress of the exact GPM was summarized.Then,the related algorithms were introduced in detail,and the experiments on the state-of-the-art exact GPM algorithms were conducted to compare their performance.Based on the experimental results,the applicable scenarios of the algorithms were pointed out.New research opportunities in this area were proposed.展开更多
String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that...String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that is created and kept by modern computational devices influences researchers to obtain even more powerful methods for coping with this problem. In this research, the Quick Search string matching algorithm are adopted to be implemented under the multi-core environment using OpenMP directive which can be employed to reduce the overall execution time of the program. English text, Proteins and DNA data types are utilized to examine the effect of parallelization and implementation of Quick Search string matching algorithm on multi-core based environment. Experimental outcomes reveal that the overall performance of the mentioned string matching algorithm has been improved, and the improvement in the execution time which has been obtained is considerable enough to recommend the multi-core environment as the suitable platform for parallelizing the Quick Search string matching algorithm.展开更多
With the (k,n) -threshold scheme of secret sharing in the field of information security technology asan application background,the concept of set ( k,n)-exact cover is presented in this paper.It is a modificationof th...With the (k,n) -threshold scheme of secret sharing in the field of information security technology asan application background,the concept of set ( k,n)-exact cover is presented in this paper.It is a modificationof the original concept of set covering problem.It is also different from the concept of exact coverdefined by J.E.Hopcroft.Some properties of ( k,n) -exact cover are investigated;a sufficient conditionfor a set to be ( k,n ) -exactly coverable is given.It follows that a feasible assignment scheme of a set forthe (k,n) -exact cover is obtained if this set satisfies the sufficient condition.展开更多
工程实际勘探对象如土壤、岩石等多为色散介质,雷达波在其中传播时易发生衰减与畸变,应用常规有限单元法(Finite Element Method,FEM)方法进行数值模拟时,存在数值频散现象.为此,作者以色散介质为研究对象,开展最优系数有限单元法探地雷...工程实际勘探对象如土壤、岩石等多为色散介质,雷达波在其中传播时易发生衰减与畸变,应用常规有限单元法(Finite Element Method,FEM)方法进行数值模拟时,存在数值频散现象.为此,作者以色散介质为研究对象,开展最优系数有限单元法探地雷达(Ground Penetrating Radar,GPR)频率域正演.首先,分析了有限元质量、刚度矩阵的约束条件对有限元求解精度的影响,基于归一化相速度与1的误差最小策略,利用最小二乘法,仅需三个优化参数求取最优的有限元刚度矩阵与质量矩阵.四种不同方法的频散曲线分析及精度对比实验结果表明,优化矩阵在单位波长仅需4.8个网格点下便可达到误差小于0.2%的精度;而一致、集中和折衷矩阵不仅需要更多的网格点,且误差较大.然后,将精确完全匹配层(Exact Perfectly Matched Layer,EPML)吸收边界条件引入最优系数频域有限单元(Finite Element Frequency Domain,FEFD)算法中,简化了吸收参数优化过程,取5层即可达到常规完全匹配层(Perfectly Matched Layer,PML)的10层的吸收效果,能够有效提升正演效率.并将基于EPML的最优系数有限单元法算法引入到城市道路病害模型正演中,实验表明:本文算法能有效压制频散并实现实际色散介质高精度模拟,模拟结果更接近波在地下介质中的实际传播特性.展开更多
无监督域自适应行人重识别(Unsupervised Domain Adaptation for person Re-identification, UDA-ReID)任务致力于将知识从已标记的源域数据转移到目标域。和传统的单源域自适应相比,将多源域的知识迁移到目标域是一项更具挑战性的任务...无监督域自适应行人重识别(Unsupervised Domain Adaptation for person Re-identification, UDA-ReID)任务致力于将知识从已标记的源域数据转移到目标域。和传统的单源域自适应相比,将多源域的知识迁移到目标域是一项更具挑战性的任务。由于领域上的差距,多数据集的简单组合只能产生有限的改进。针对此问题,提出了一种基于精确特征分布匹配和多域信息融合的多源域对比学习(exact feature distribution Matching and multi-domain information Fusion based Multi-domain Contrastive Learning, MFMCL)方法。该方法首先采用具有混合记忆的自步对比学习提取不同域数据的特征,并对提取到的特征进行构图,然后通过两层残差图卷积网络进行多域特征融合。其次,为了增强交叉分布特征、产生更丰富的信息,通过基于排序算法的精确直方图匹配来实现精确特征分布匹配,以获得更多样化的特征增强。实验表明,与目前先进的无监督域自适应行人重识别方法相比,所提出的MFMCL方法在广泛使用的行人重识别数据集Market1501、MSMT17和Duke上都取得了优越的性能。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 30270810, 90208022 and 30471067) and IBM Shared University Research (Life Science), China
文摘Mutation (substitution, deletion, insertion, etc.) in nucleotide acid causes the maximal sequence lengths of exact match (MALE) between paralogous members from a duplicate event to become shorter during evolution. In this work, MALE changes between members of 26 gene families from four representative species (Arabidopsis thaliana, Oryza sativa, Mus mus- culus and Homo sapiens) were investigated. Comparative study of paralogous’ MALE and amino acid substitution rate (dA<0.5) indicated that a close relationship existed between them. The results suggested that MALE could be a sound evolutionary scale for the divergent time for paralogous genes during their early evolution. A reference table between MALE and divergent time for the four species was set up, which would be useful widely, for large-scale genome alignment and comparison. As an example, de- tection of large-scale duplication events of rice genome based on the table was illustrated.
文摘Graph pattern matching(GPM)can be used to mine the key information in graphs.Exact GPM is one of the most commonly used methods among all the GPM-related methods,which aims to exactly find all subgraphs for a given query graph in a data graph.The exact GPM has been widely used in biological data analyses,social network analyses and other fields.In this paper,the applications of the exact GPM were first introduced,and the research progress of the exact GPM was summarized.Then,the related algorithms were introduced in detail,and the experiments on the state-of-the-art exact GPM algorithms were conducted to compare their performance.Based on the experimental results,the applicable scenarios of the algorithms were pointed out.New research opportunities in this area were proposed.
文摘String matching is seen as one of the essential problems in computer science. A variety of computer applications provide the string matching service for their end users. The remarkable boost in the number of data that is created and kept by modern computational devices influences researchers to obtain even more powerful methods for coping with this problem. In this research, the Quick Search string matching algorithm are adopted to be implemented under the multi-core environment using OpenMP directive which can be employed to reduce the overall execution time of the program. English text, Proteins and DNA data types are utilized to examine the effect of parallelization and implementation of Quick Search string matching algorithm on multi-core based environment. Experimental outcomes reveal that the overall performance of the mentioned string matching algorithm has been improved, and the improvement in the execution time which has been obtained is considerable enough to recommend the multi-core environment as the suitable platform for parallelizing the Quick Search string matching algorithm.
基金Supported by the National Natural Science Foundation of China (No. 60673053 90718011 )
文摘With the (k,n) -threshold scheme of secret sharing in the field of information security technology asan application background,the concept of set ( k,n)-exact cover is presented in this paper.It is a modificationof the original concept of set covering problem.It is also different from the concept of exact coverdefined by J.E.Hopcroft.Some properties of ( k,n) -exact cover are investigated;a sufficient conditionfor a set to be ( k,n ) -exactly coverable is given.It follows that a feasible assignment scheme of a set forthe (k,n) -exact cover is obtained if this set satisfies the sufficient condition.
文摘工程实际勘探对象如土壤、岩石等多为色散介质,雷达波在其中传播时易发生衰减与畸变,应用常规有限单元法(Finite Element Method,FEM)方法进行数值模拟时,存在数值频散现象.为此,作者以色散介质为研究对象,开展最优系数有限单元法探地雷达(Ground Penetrating Radar,GPR)频率域正演.首先,分析了有限元质量、刚度矩阵的约束条件对有限元求解精度的影响,基于归一化相速度与1的误差最小策略,利用最小二乘法,仅需三个优化参数求取最优的有限元刚度矩阵与质量矩阵.四种不同方法的频散曲线分析及精度对比实验结果表明,优化矩阵在单位波长仅需4.8个网格点下便可达到误差小于0.2%的精度;而一致、集中和折衷矩阵不仅需要更多的网格点,且误差较大.然后,将精确完全匹配层(Exact Perfectly Matched Layer,EPML)吸收边界条件引入最优系数频域有限单元(Finite Element Frequency Domain,FEFD)算法中,简化了吸收参数优化过程,取5层即可达到常规完全匹配层(Perfectly Matched Layer,PML)的10层的吸收效果,能够有效提升正演效率.并将基于EPML的最优系数有限单元法算法引入到城市道路病害模型正演中,实验表明:本文算法能有效压制频散并实现实际色散介质高精度模拟,模拟结果更接近波在地下介质中的实际传播特性.
文摘无监督域自适应行人重识别(Unsupervised Domain Adaptation for person Re-identification, UDA-ReID)任务致力于将知识从已标记的源域数据转移到目标域。和传统的单源域自适应相比,将多源域的知识迁移到目标域是一项更具挑战性的任务。由于领域上的差距,多数据集的简单组合只能产生有限的改进。针对此问题,提出了一种基于精确特征分布匹配和多域信息融合的多源域对比学习(exact feature distribution Matching and multi-domain information Fusion based Multi-domain Contrastive Learning, MFMCL)方法。该方法首先采用具有混合记忆的自步对比学习提取不同域数据的特征,并对提取到的特征进行构图,然后通过两层残差图卷积网络进行多域特征融合。其次,为了增强交叉分布特征、产生更丰富的信息,通过基于排序算法的精确直方图匹配来实现精确特征分布匹配,以获得更多样化的特征增强。实验表明,与目前先进的无监督域自适应行人重识别方法相比,所提出的MFMCL方法在广泛使用的行人重识别数据集Market1501、MSMT17和Duke上都取得了优越的性能。
