无向反转排序问题的遗传模拟退火求解

在推断两个基因组的进化关系上反转排序是一个重要问题.无向排列排序问题已被证明是一个NP-困难问题,目前,最好的算法是3/2-近似算法.基于一个无向排列π的反转距离等于由π所生成的包含2n个有向排列集Sign(π)中最优排列的反转距离,给出应用遗传模拟退火算法计算基因组重排的反转距离的方法.实验结果显示,这个方法优于3/2-近似算法.     

用模拟退火算法求解无向排列的反转排序问题

分子生物学中基因无方向的反转基因组重排问题在数学上已被证明是一个NP-难问题.目前,较好的算法是Christie(2001)的3/2-近似算法.本文给出一种适合于计算基因无方向的反转基因组重排问题的模拟退火算法,定义了解的邻域结构.数据实验的结果表明该算法性能优于3/2-近似算法.     

基于免疫算法的无向排列的反转排序问题

提出一种基于免疫算法的无向排列的反转排序的方法,将一种免疫算子加入到遗传算法的框架中,通过对个体接种疫苗来进一步提升个体的存活能力.数据实验的结果表明,该算法性能优于Christe提出的3/2-近似算法.     

基于免疫算法的无向排列的反转排序问题

提出一种基于免疫算法的无向排列的反转排序的方法，将一种免疫算子加入到遗传算法的框架中，通过对个体接种疫苗来进一步提升个体的存活能力。数据实验的结果表明，该算法性能优于Christe提出的3/2-近似算法。     

用模拟退火算法求解无向排列的反转排序问题

分子生物学中基因元方向的反转基因组重排问题在数学上已被证明是一个NP-难问题。目前，较好的算法是Christie(2001)的3／2-近似算法，本文给出一种适合于计算基因元方向的反转基因组重排问题的模拟退火算法，定义了解的邻域结构，数据实验的结果表明该算法性能优于3／2-近似算法。     

含有反转、删除或插入操作的部分排序基因组重组

Zheng等给出了一个只含有反转操作的部分排序基因组重组的算法.本文推广了这一结果,给出了允许有删除或插入操作的两个含有不同基因集合的部分排序基因组重组的算法.     

装箱问题的一种新的近似算法

 研究了一维装箱问题(Bin Packing Problem),给出了一个新的近似算法:交叉装填算法(简称CF算法).证明了CF算法达到装箱问题的最好的近似值3/2;并且当这些物件的大小按非增性质预先排序后,CF算法的时间复杂度是线性的.     

有向基因组间重组距离的线性时间计算

讨论基于基因组中染色体之间的移位、染色体内部的翻转、融合和分裂的基因组排序问题,给出了计算两个有向多重基因组重组距离的线性时间算法.     

柞蚕微孢子虫基因组LTR反转座子鉴定与进化分析

【目的】鉴定柞蚕微孢子虫(Nosema pernyi)基因组中LTR反转座子的种类、数量和遗传关系。【方法】从GenBank数据库下载柞蚕微孢子虫基因组序列,采用MGEScan软件筛选潜在重复元件,通过NCBI-BLAST与不同物种的逆转酶进行比对,含有逆转录酶结构域的序列认定为LTR反转座子,并探讨它们的结构特征、所属类型和基因组分布特点。【结果】从柞蚕微孢子虫基因组中共发现6个LTR反转座子家族即Nar1,Nar2,Nar3,Nar4,Nar5和Nar6,长度在3～4kb之间;大部分家族有相似的LTR末端核苷酸,但靶位点重复和拷贝数存在差异;逆转录酶结构域系统进化树显示6个LTR反转座子家族均属于Ty3/Gypsy类型,且与家蚕微孢子虫(Nosema bombycis)LTR反转座子形成姊妹分支;Nar2和Nar4家族在基因组上成串排列,具有相似的分布特征。【结论】柞蚕微孢子虫基因组中存在Ty3/Gypsy类型的LTR反转座元件,进化地位与家蚕微孢子虫最为接近;LTR反转座子家族重复元件在基因组上成串排列,可能是柞蚕微孢子虫基因组扩张的潜在因素之一。     

一类资源约束排序问题1|p_j=b_j-a_ju_j,∑w_jC_j≤A|∑u_j

讨论一类资源约束排序问题 1 |pj=bj-ajuj, wjCj≤A| uj,给出一个求解算法 ,给定一个排列 ,该算法能求出相应这个排列的最优排序 ,或断定该排列无相应的可行排序     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.