遗传算法在试题库自动组卷中的应用

采用基于矩阵编码的遗传算法求组卷问题，提出了该算法的交叉算子和变异算子。实验证明，该算法可以很好地解决自动组卷问题。     

遗传算法在排课问题中的应用

在分析造成排课困难的各种因素的基础上,将遗传算法运用到解决排课问题中.并给出了该算法的详细设计（文中采用了二进制编码和矩阵编码相结合的编码方法;给出了带有权值的适应度函数;对染色体中的时间码采用映射同/异或交叉;采用两点变异的变异方法）和排课模型;很好地解决了多约束条件下的排课问题.     

遗传算法在智能组卷系统中的应用研究

为更好地解决遗传算法在智能组卷过程中出现的早收敛问题,以及组卷质量和组卷速度呈负相关的问题,提出一种基于分段整数编码、多点交叉的遗传算法.通过大量实验,有针对性地对该算法中的编码结构、选择算子、交叉算子和变异算子进行优化设计;对相关控制参数进行合理调整,实验结果表明,该算法不仅有效地提高了组卷质量和组卷速度,而且具有很好的收敛性.     

矩阵编码的遗传算法

针对遗传算法在求解矩阵运算的优化问题时,会出现编码过长或编码、解码复杂的现象。提出一种新的矩阵编码方式,同时也详细给出在矩阵编码下的交叉算子、变异算子和解码公式,可有效地解决编码过长和编码、解码复杂的问题。矩阵编码的遗传算法既可以保持二进制编码的交叉和变异的灵活性,又能适合于矩阵优化计算。     

基于动态自适应遗传算法的舰艇防空火力分配

本文提出一种基于自适应编码思想的遗传算法用于解决水面舰艇防空火力分配问题,该算法采用自适应编码,自适应选择与自适应的交叉与变异算子,能在较短的时间内得到全局优化解。仿真实验结果表明:新算法与其他算法相比,在优化性能和时间性能方面都有了一定的改善,可以较好地避免陷入局部最优,能较好地解决舰艇防空火力分配问题。     

基于混合遗传算法的多UCAV协同任务分配方法

针对多UCAV协同作战的控制决策问题,提出了多UCAV任务分配的多目标整数规划模型.将问题的启发性知识融合进遗传算法,提出了求解该问题的基于整数编码的混合遗传算法.将变量根据约束条件特点分为自由变量和非自由变量,仅对非自由变量编码,减小了染色体长度和变化要素,从而提高了算法的效率.设计了适于整数编码的交叉和变异算子,并巧妙地利用约束条件限制变异范围,以提高个体满足约束条件的概率.以UCAV的SEAD任务为想定,进行了仿真实验.实验结果表明混合遗传算法可以有效地解决大规模整数规划问题,在求解效率和提高约束条件满足率上优于标准遗传算法.     

用单亲遗传算法解决影片递送问题

遗传算法(简称GA)是基于生物进化原理的普适性全局优化算法，是解决NP难问题的一种行之有效的方法．但是，序号编码的遗传算法不能在任意两条染色体的任意位置进行交叉，必须使用PMX，CX和OX等特殊的交叉算子，这些算子实施起来都很麻烦且效率不高．针对这一问题，采用单亲遗传算法，取消交叉操作，强化变异作用．这样既简化了遗传操作，又克服了早熟现象．较成功的解决了影片递送问题，文中的算例表明，该算法是实际有效的．     

基于遗传算法的车间设备虚拟布局优化技术研究

根据车间布局设计的最小物流费用原则,建立车间设备布局优化模型,并对该优化模型进行遗传算法求解．借鉴车间设备布局的块树表示法,设计了基本块、分割线和方向的混和染色体,并给出解码方法．根据车间布局优化的特点,改进选择算子、交叉算子和变异算子等遗传操作算子,设计基于块树的分割线有效性检验算法,并融合了选择交叉算法的优点,有效地避免了遗传过程中无效个体的大量出现,保证了算法的有效性和高效性．最后,给出了一个12台设备车间布局仿真算例,结果表明,算法快速地在进行到170代左右时达到了收敛,并采用虚拟现实技术将计算结果形象地呈现出来．本文所提出的方法能够很好地解决车间设备虚拟布局问题．     

并行机调度问题的最优公共交货期和最优调度

现有的提前／拖后调度问题主要针对单机情况，且大多采用启发式方法。为了有效地解决带有待定公共交货期的并行机提前／拖后优化调度问题，提出了一种分段编码的遗传算法，使遗传编码能同时反映调度方案和公共交货期，并对初始种群产生、交叉和变异方法作了研究。计算实例表明了该遗传算法有很好的性能，所得解的质量优于启发式算法，且适用于较大规模并行机提前／拖后优化调度问题     

实数编码遗传算法能解性

通过分析一类标准的实数编码遗传算法算子作用机制及其交叉算子的局部搜索特性,提出了变异的方向性的概念,指出变异算子向各个方向变异并非均匀,而是以坐标轴方向分布最多.同时定义并分析了变量可分离函数优化问题.数值试验结果表明,实数编码遗传算法比较合适求解变量可分离的函数优化问题.     

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).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

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.