一个新的光滑低阶精确罚函数

对不等式约束优化问题提出了一种新的低阶精确罚函数的构造,使其转化为易求解的无约束优化问题;给出了光滑罚问题与非光滑罚问题,光滑罚问题与原问题的目标函数值之间的误差估计,并且在弱的假设条件下证明了光滑罚问题的全局最优解是原问题的近似最优解.     

非光滑规划的精确罚函数

0 引言罚函数方法是数学规则求约束最优解的重要方法之一.自60年代Zangwill等人系统地研究罚函数理论以来,发展很快,文献很多.经典的罚函数理论,是通过添加罚函数项后,研究一系列无约束优化问题,并使惩罚参数趋于无限大来获得原规划的最优解.而精确罚函数理论是通过求解单个无约束优化问题来求原规划的最优解.     

两个绝对值优化问题解的等价性

针对损失函数为最小一乘问题,惩罚项由基数函数定义的绝对值优化问题,提出用MCP(Minimax Concave Penalty)非凸正则来连续逼近基数罚,得到一个精确连续的绝对值优化松弛问题。首先,证明了带基数罚的绝对值优化问题的全局最优解;其次,研究了带基数罚的绝对值优化问题与带MCP罚的绝对值优化松弛问题之间全局最优解的等价性;最后,证明了在一定的条件下这两个绝对值优化问题具有相同的全局最优解。     

一类联合最大特征值函数优化问题

非光滑凸优化问题是运筹学的一类重要问题.束方法作为解决非光滑凸优化问题最有效的方法之一,已经被广泛地应用于各个领域.运用束方法对最大特征值函数与一般非光滑凸函数之和的优化问题进行研究.首先,对目标函数进行近似;其次,给出求解此类优化问题的带有罚项的束方法算法;最后,通过收敛性分析证明了算法产生的序列会收敛到原问题的最优解.     

约束DC优化的双束法及对偶问题

针对带有凸不等式约束的非光滑DC优化问题,提出了一种基于罚函数的凸约束DC优化问题双束法,同时也刻画了双束法子问题的对偶问题;首先,利用L_1精确罚技巧把凸约束DC优化问题转化成无约束DC优化问题,便于直接对目标函数进行DC分解,然后分别建立了增广目标函数DC分量的凸分段线性近似模型,最后利用Lagrange函数得到了原问题和对偶问题最优解之间的等价关系,说明了利用对偶问题求解搜索方向的可行性和有效性。     

罚函数的性质及ι_1精确罚函数的存在性

本文讨论了一种常见的罚函数，给出并证明了罚函数的全局最优解存在的一个充分条件，及原问题的局部最优解与罚函数的局部最优解之间的关系的一个定理，并对［２］中ｌ１罚函数的一个精确罚函数存在性定理，给出了较为简单的证明．     

一类光滑罚算法的全局收敛性

对约束优化问题给出了一类光滑罚函数,它是根据一类光滑逼近精确罚函数的光滑函数而提出来的,并基于这类罚函数给出了罚算法.在很弱的条件下,建立了光滑罚算法的一个摄动定理,由此定理得到该罚算法的全局收敛性.     

解非线性规划的一个可微"准"精确罚函数法

将文[1]中" "函数的光滑近似函数应用于求解非线性规划问题,该方法通过解一个可微"准"精确罚函数逐渐去逼近原问题的最优解,并且可以通过参数的选取控制解的误差,给出了几个演示性算例.该算法克服了非线性规划极大熵函数法易溢出的缺陷.     

一种新的求解带等式约束的极大极小问题的罚函数

通过对经典的一类简单精确非光滑罚函数进行局部光滑化处理,及相应调整罚参数和光滑参数,构造出一种新的简单的光滑罚函数,将带等式约束的极大极小问题转化为对罚函数的无约束优化问题.初步的数值实验表明该罚函数算法是可行有效的.     

机会约束优化问题的Log-Sigmoid近似

许多具有重要价值的实际问题的数学模型均为机会约束优化问题,该类问题通常是非凸且非光滑的,有效求解方法多集中于凸近似。基于Log-Sigmoid函数,将机会约束函数光滑化并且建立相应的光滑近似问题。通过收敛性分析,证明了当参数充分小时,光滑近似问题的可行集、最优值和最优解集分别收敛于真问题的可行集、最优值和最优解集。     

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)

正~~     

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.