改进蚁群算法求解多目标优化问题

针对传统蚁群算法在多目标优化问题中容易陷入局部最优的缺点,提出一种采用直接学习机制的改进蚁群算法。该算法通过采用模拟蚂蚁用触角交流信息过程的直接通信学习机制,用以改进信息素的更新规则,从而维持群体的多样性。通过两组多目标基准函数验证算法性能,仿真结果表明该算法所获得的Pareto解具有多样性以及均匀分布性,有效地提高了蚁群算法全局寻优的能力。     

团队进步算法在Ad-hoc网络优化问题中的应用

针对Ad-hoc网络优化问题,提出了一种分布式团队进步算法。算法将成员信息在节点间作分布式存储,从成熟成员中确定发起人以负责产生新成员和发布被淘汰成员信息,而新成员的评价则在其对应节点上完成。在一个ad-hoc协同计算系统中搜索具有最低处理负载的节点的模拟试验表明,该算法具有通信开销小、收敛速度快等优点,对同类优化问题具有参考价值。     

一种考虑环境作用的协同免疫遗传算法

在综合考虑了环境对生物进化的影响、免疫算法的结构以及遗传算法部分算子的基础上,提出一种考虑环境作用的协同免疫遗传算法(ESIGA),以实现提高算法搜索速度和全局搜索能力的目标.在该算法中,设计了克隆环境演化算子和自适应探索算子,并构造了3个子种群协同进化以发挥克隆环境演化算子的影响,从而提高算法的全局搜索能力.引入的自适应探索算子和克隆环境演化算子,使算法具备了一定的学习能力,可加速搜索和防止早熟.构建的主种群和协同种群相互影响,使得算法对环境具有改良能力,加强了克隆环境演化算子的性能,而精英种群则加强了算法在优质个体邻域的搜索能力.采用13个常用无约束优化问题测试函数对算法做了检验,测试数据表明:ESIGA算法与正交遗传算法相比,其搜索速度要快于正交遗传算法1～2倍,并能够处理1 000维的高维优化问题.     

全局粒子群优化算法

针对粒子群优化算法在解决大维数的无约束优化问题时具有较差的收敛性和稳定性,提出了一种全局粒子群优化(GPSO)算法.GPSO算法引入了一种新的惯性权重,它被定义为一个指数型函数与一个随机数的乘积,这有利于维持算法的全局搜索和局部搜索.同时,GPSO算法对全局最优解进行了小的扰动,这可以有效地避免算法早熟.使用三种粒子群优化算法来解决6个无约束优化问题.仿真结果说明,与其他两种粒子群优化算法相比,GPSO算法具有更快的收敛速度和更强的逃离局部最优的能力.     

一种改进的混合蛙跳算法及其在变压器设计中的应用

提出一种求解约束优化问题的自适应混合蛙跳算法.引入移动步长变异算子,通过算法所处迭代阶段的测量值和进步速度自适应调整移动步长.3种典型直径的变压器铁心柱截面优化设计仿真结果表明,该算法具有更强的全局搜索能力,达到了增大截面积、节省生产材料、降低运行损耗的目的.     

融合混沌和捕食搜索的混合粒子群算法

针对标准粒子群算法在处理复杂函数时存在的收敛速度慢、易陷入局部最优的缺点,提出了新的混合粒子群算法.该算法利用混沌运动的遍历性、对初始条件的敏感性等特性进行群体的混沌初始化,且捕食搜索策略可以通过调节限制级别的控制粒子群的搜索空间,从而平衡全局搜索和局部搜索.测试结果表明,新算法具有更快的收敛速度和更强的全局寻优能力.     

一种改进的自适应和声搜索优化算法

在传统和声搜索优化算法的基础上,提出一种自适应双子和声搜索优化算法。通过建立主辅两个和声库正反双向进行迭代搜索,并对和声算法中的音调调整概率和音调微调带宽两个重要参数进行自适应调整,提高了算法的动态适应性以及局部搜索和全局搜索的协调能力。通过构造两组搜索方向各异、相互协同的主、辅和声,充分利用了搜索域内的隐含信息,扩展搜索范围,从而实现了全局最优。在试验中分别对3个复杂函数进行测试,结果表明该算法具有较好的全局搜索能力和收敛速度,在一定程度上提高了最优值的搜索能力,达到了预期效果。     

求解大规模可靠性问题的改进差分进化算法

针对差分进化算法典型变异算子的局限,设计了全局加速的变异算子,进而提出全局加速的自适应改进算法.新变异算子能够均衡全局搜索与局部搜索,提高寻优效率.根据差分向量与整个种群分布范围的关系,有针对性的设定变异率值,减缓搜索范围缩小的趋势,保持较高的种群多样性.采用两区间选择策略,通过学习和比较自适应地调整交叉率,使其满足进化搜索的需要,同时提高算法的通用性.将改进算法应用于大规模可靠性问题中,实验结果表明,改进算法在解决大规模系统可靠性问题时具有更好的寻优效果.     

改进动态蚁群算法在低压电力线载波通信动态路由中的应用研究

从提高通信可靠性的角度出发,探讨了低压电力线载波动态路由问题,采用一种新的改进动态路由算法。该方法从局部更新规则和全局更新规则两方面对基本蚁群算法进行改进,引入了局部最差路径和全局最差路径概念,提高了动态路由搜索的准确度和效率。仿真和实验结果表明该方法在节点个数较多时,随着迭代次数的增加寻找最佳路径时较稳定。     

基于多信息素的蚁群算法

针对传统增强型蚁群算法容易出现早熟和停滞现象的缺陷,提出一种多信息素的蚁群算法(MPAS),并以TSPLIB的数据为例对该算法进行实验测试.MPAS算法将信息素分为局部和全局两种不同的信息素,在搜索过程中,对局部和全局信息素采用不同的更新策略和动态的路径选择概率,使得在搜索的中后期能更有效地发现全局最优解.在中大型问题上MPAS算法有着更好的发现最优解的能力.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

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.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

A computer generator for randomly layered structures

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

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

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.     

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。     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that