用遗传算法求解多目标0/1背包问题

扼要介绍多目标优化的Pareto最优性概念 ,研究搜索多目标 0 1背包问题Pareto最优解集的快速遗传算法 (FPGA :fastParetogeneticalgorithms) .FPGA采用种群中非支配解的层次评价可行解的适应值 ,提出了一种快速非支配解层次辨识算法 ,辨识算法仅有O(n2 )数量级的计算复杂性 ;采用基于聚类概率排挤的小生态技术维持种群多样度和Pareto最优解集的分布均匀性。对多种多目标 0 1背包问题的仿真优化实验结果表明 ,FPGA能够以有效的计算成本搜索到精度高的、分布均匀的高质量Pareto非劣解集 ,其收敛速度和收敛准确性一致地优于代表性的强度Pareto进化算法 (SPEA) .     

一类改进的蚁群算法及其收敛性分析

在基本蚁群算法的基础上,提出了一类改进的蚂蚁算法,并证明了当算法迭代次数n充分大时,对于任意小ε>0,算法至少一次找到最优解的概率P*(n)≥1-ε,当n→∞时,P*(n)→1.数值实验表明,改进的算法在取得满意搜索结果的同时,能减少算法的计算量.     

一种改进的Grover量子搜索算法

经分析发现,Grover量子搜索算法及Long的改进算法均无法达到100%成功概率的搜索结果,为此在Long的改进算法基础上提出了一种新的搜索算法.它主要将相位取反替换成具有自适应调整特点的、与目标数据量和数据总量有关的相位旋转,当目标数据量为数据总量的1/2时,将数据总量扩展2倍,这样算法的搜索可以做到100%的成功概率.通过对背包问题的仿真研究表明,所提算法优于Grover算法和Long的改进算法,其求解速度快、准确率高,在带有数据误差的实际问题求解中进行相位匹配能够得到满意的效果.     

一种自适应多样性保持的多目标粒子群算法

提出一种自适应多样性保持的多目标粒子群算法(ADMMOPSO)。该算法引入多样性保持阈值(λα)来控制非劣解的分布,当多样性指标高于阈值λα时,引入一种基于网格的全局最优粒子的选择策略增加种群向真实Pareto前沿收敛的概率,并提升非劣解的多样性。通过4个测试问题和3个测试标准,并与其他算法进行比较,结果表明ADMMOPSO获得了质量较高的非劣解。     

流水车间排列排序专家系统—PFSCH

流水车间排列排序问题可以简单表示为:n/m/p/F_(max),其含义为,n个不同的工件(J_1,J_2,…,J_n)要经m台机器(M_1,M_2…,M_m)加工;加工路线为M_1—M_2—…—M_m,n个工件在每台机器上的加工顺序都一样;p表示排列排序;目标函数是使最长流程时间F_(max)(加工周期)最短.n个工件有n!种不同的加工顺序.现已证明,n/m/p/F_(max)(m≥3)问题属于NP难题,找不到多项式时间算法.因此,人们提出了若干个启发式算法,其中最著名的是Campbell等人提出的启发式算法(简称为CDS法).Dannenbring曾比较过11种不同的启发式算法的效果,指出“快速接近扩展搜索法(RAES法)”的结果最好.但是,RAES法实质上还是一种列举法,它不从问题本身的结构出发,具有很大的盲目性.虽     

关于不定方程x2+4n=y11的整数解

应用代数数论以及同余法等初等方法讨论不定方程x~2+4~n=y~(11)的整数解情况,证明了不定方程x~2+4~n=y~(11)在x为奇数,n≥1时无整数解;不定方程x~2+4~n=y~(11)在n∈{1,8,9,10}时均无整数解;不定方程x~2+4~n=y~(11)有整数解的充要条件是n≡0(mod 11)或n≡5(mod 11),且当n≡0(mod 11)时,其整数解为(x,y)=(0,4~m);当n≡5(mod 11)时,其整数解为(x,y)=(±2~(11m+5),22m+1),这里的m为非负整数,验证了k=11时猜想1成立。     

机载预警雷达牵引模式的IRST探测效能分析

机载预警雷达牵引红外搜索跟踪系统(IRST)探测是同平台多传感器协同的一种重要工作模式。为定量评估该模式对IRST探测效能的影响,以IRST探测概率作为评估指标,建立多个瞬时视场下的成功牵引概率数学模型,计算在不同雷达工作模式下满足一定成功牵引概率的IRST搜索视场范围,推导IRST的探测概率与作用距离、脉冲积累之间的关系式。仿真结果表明,在保证成功牵引概率为0.99的前提下,雷达在高精度测量模式下的牵引效果最佳,使IRST的搜索区域缩小为原来的1/180,时间节约效率为99.4%,加快了对目标的截获过程。节余的时间可用来对目标进行脉冲积累,当积累2个脉冲时,在其最大作用距离处所对应的探测概率由无积累时的0.5提升到0.985 3,从而显著提升其探测效能。     

关于方程Sx(n)=Sy(3)

对于正整数m、n(n≥ 3) ,设Sm(n)是第m个n角数 .证明了 :当n >6且n - 2是平方数时 ,方程Sx(n) =Sy(3)无正整数解 (x ,y) ;当n >6 ,2 n且n - 2非平方数时 ,该方程有无穷多组正整数解 (x,y) .     

测度按Kakutani距离的收斂

设可测空间(G,β)上的两个有限测度为m,n,令 (G,β)上概率测度全体记为M,当m,n∈M时,d_2退化为 定理 1 可测空间(G,β)上的概率测度全体M,按拟距离d(m, n)、d_2(m,n)、d_2(m,n)     

基于双种群粒子群优化新算法的最优潮流求解

提出一种带赌轮选择的双种群粒子群优化算法(TSPSO)求解最优潮流问题。在该算法中,对2个种群采取不同的参数设置,使得粒子在进化过程中具有不同的飞行轨迹,从而尽可能地探索解空间,增强算法的全局搜索能力;基于赌轮算法的概率选择机制使粒子可以在较好的可行解邻近范围内高强度搜索,增强了算法的局部搜索能力;采用自适应惩罚因子能有效区分最优潮流的目标函数和约束条件对种群进化的影响,使种群可以跨越不可行域到可行域进行搜索。通过IEEE30节点系统对该算法进行测试,结果表明,采用该算法可以有效求解最优潮流问题。     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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