线性规划内点算法的若干收敛性问题

对于线性规划问题 ｍｉｎ｛ｃтｘ｜Ａｘ≥ｂ，ｘ≥０｝，印度学者 и．Ｋａｒｍａｒｋａｒ于 １９８４年发明 了一种新的内点算法，它的时间复杂性为Ｏ（ｎ３．５Ｌ２），其中ｎ为问题的变量个数，Ｌ为输 入中的二进制位数。其后又出现了多种变形方案，如原始型和对偶型内点算法等等。本 文主要讨论它们的收敛性问题。关于Ｋａｒｍａｒｋａｒ算法，证明了当原始线性规划问题无有 限最优解时算法也可以收敛。关于原始型和对偶型内点算法，给出了它们的基本性质以 及若干收敛性结果。     

求解Fisher市场均衡问题的内点算法

Fisher 市场均衡是经济学中的经典问题，可以用线性权互补问题来表述。通过调整中心方向向可行点偏移得到新的搜索方向以保证可行性，再利用线性搜索寻找满足邻域条件的最大更新参数来设计求解Fisher市场均衡问题的算法，分析了算法的可行性，证明了算法的迭代复杂度。数值实验结果表明该算法对求解Fisher市场均衡问题是有效的。     

框式线性规划的原始——对偶不可行内点算法的进一步研究

进一步研究「１」中对框式线性规划提出的原始－对偶不可行内点算法,并证明了如果算法迭代按终止准则的后半部分停止,原始－对偶规划具有某种不可行性。     

凸二次规划的不可行内点算法

给出了一个求解凸二次规划的不可行点内点算法，算法的初始迭代点为非负不可行内 ，证明了算法的全局收敛性。该算 法可以看作是Ｋｏｊｉｍａ算人关于线性规划算法的推广，也可以看作是Ｍｏｎｔｅｉｒｏ等人关于可行内点算法的推广。     

一种新的线性规划不可行内点算法

提出了一个新的求解线性规划问题的不可行内点算法,这个算法每一步只须解一个线性方程组,算法是基于路径跟踪算法思想,适当选取初始点,算法至多可在Ｏ（ｎｌ）迭代步获得ε－可行性和ε－互补性,算法具有每一步的计算量少的特点。     

半定规划的原始-对偶不可行内点算法

对于半定规划问题,通过构造适当的搜索方向,给出了一个原始-对偶不可行内点算法.证明了该算法经过有限步迭代后,或者在某个较大的区域得到问题的一个近似最优解,或者说明问题在该区域内无解.     

凸二次规划问题的内点算法

提出了一类利用对数障碍函数法求解凸二次规划问题的内点算法，此算法在每次迭代中只需解一个等式约束的二次规划问题(或线性方程组系统)，结构简单，易于计算，最后运用数值仿真测试验证了此方法的有效性。     

单调线性互补问题的非精确不可行内点算法

对单调线性互补问题提出了一种非精确不可行内点算法．该算法的迭代方向仅需要达到一个相对的精度．在初始点位于中心线的某邻域内的假设下，证明了算法的全局收敛性．     

线性规划中几种内点算法的比较

该文是关于内点算法的一篇综述,对几种较为实用的求解线性规划问题的算法进行总结,包括单纯形法、椭球算法、Karmarkar算法、原仿射尺度算法等,并对这些算法进行比较。     

几何规划的投影内点算法

基于内点算法思想,利用投影技术设计了求解约束正定式几何规划的一种新的算法,在合理的条件下证明了所提供的算法的收敛性质.此算法具有计算量小,稳定性强等优点.     

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.