飞机移动生产线物料配送与空箱回收集成建模

为了解决飞机移动生产线中作业物料的供给问题,构建了飞机移动生产线物料配送与空箱回收集成决策的模型并设计了求解算法.在物料组批和小车调度的基础上,引入了空箱的回收决策,建立了以小车出行次数最小化为目标的数学模型并设计了一种以遗传算法为框架的启发式算法.在遗传算法较优的全局搜索能力下,综合考虑小车的运载能力与线边空间的存储能力,设计了启发式算法对物料与空箱的组批方式以及小车出行时刻三类变量联合进行决策,并结合了局部搜索算法进行再优化.对提出的算法进行了数值实验,实验结果证明了模型与算法的有效性.     

飞机移动生产线物料配送与线边存储集成优化

为了解决飞机移动生产线中多并行作业物料的供给问题,构建了飞机移动生产线物料配送与线边存储集成决策的模型并设计了求解算法.在物料组批和小车调度的基础上,引入了物料在线边空间的存储决策,建立了以小车出行趟数最小化为目标的数学模型并设计了一种以免疫算法为框架的启发式算法.在免疫算法较优的全局搜索能力下,综合考虑小车的配送能力与线边空间的重复使用、共享等因素,使用反向动态小车调度算法和物料存储前瞻算法对物料的组批方式、配送时刻和在线边的存放位置三类变量联合进行决策.对提出的算法进行了数值实验,实验结果证明了模型与算法的有效性.     

基于循环配送策略的汽车装配线物料配送调度方法

为有效解决基于循环配送策略的汽车装配线物料配送调度问题,进行了改进型免疫克隆选择算法的调度方法研究.首先,建立了数学规划模型,以最小化计划期内所有工位的线边总库存为优化目标,并提出了改进型免疫克隆选择算法.在算法设计过程中融入了模拟退火算子和邻域搜索算子,分别对克隆种群和记忆库进行操作,以克服传统免疫克隆选择算法易陷入局部最优、搜索深度不足等缺陷.最后进行了仿真实验,表明该算法是有效、可行的.     

基于改进多目标布谷鸟搜索算法的 汽车装配线物料配送调度

考虑将电动车辆用来进行基于点对点配送策略的汽车装配线的物料配送,提出了改进多目标布谷鸟搜索算法. 首先,对该物料配送调度问题进行描述,在统筹考虑电量限制和准时化配送要求的基础上建立了以车辆数量和最长搬运时间作为衡量指标的目标函数,并开发了直接反映配送车辆和配送次序的融合编码机制. 然后,设计任务分配规则构造初始解,并在基于混沌动态步长的搜索过程中加入高斯变异和精英选择策略来提高算法的全局搜索能力和解的质量. 此外,开发两种局部搜索算子以强化算法深度寻优能力. 最后,仿真实验结果验证了该调度算法的可行性和有效性.     

考虑能耗的混流装配线物料配送多目标调度方法

为了提高混流装配线物料配送的能源利用效率，考虑采用“转运”概念的送料机器人和线边集成超市配送模式，构建了存在换电情形的物料供应模型.结合送料机器人的能耗特点，以最小化送料机器人的使用数量和配送能耗为优化目标，建立了数学模型.在此基础上提出了变邻域搜索策略的改进型离散差分进化算法(VNS-MDDE)，用以解决多目标优化问题；该算法以最近邻启发式方法构建初始解，并引入变邻域策略进行局部搜索以提高解的质量.最后通过仿真实验验证了算法的可行性和有效性.     

基于离散蜂群的应急物流车辆调度算法

为在尽可能满足应急物流时间要求的前提下最大程度的节约运输成本,提出了一种基于离散蜂群的应急物流车辆调度算法.该算法首先综合考虑运输车装载容量和受灾点的单边硬时间窗约束,构建了以最小化配送成本为目标的数学规划模型,然后利用离散蜂群算法进行优化求解,通过引入离散差分搜索强化其领域搜索能力,同时借助侦查蜂进行个体淘汰操作,从而避免算法陷入局部最优.仿真实验表明,与基于蚁群算法的应急物流车辆调度算法相比,该算法具有较强的鲁棒性,能够快速获得应急物流车辆调度问题的优质解.     

考虑设备可靠性与能耗的平行机调度

在考虑能耗的平行机调度问题中同时考虑设备可靠性对能耗成本的影响,以最小化延迟成本和能耗成本加权和为调度目标,建立数学规划模型.设计了蚁群算法对问题进行求解,引入一种新的启发因子定义蚁群搜索过程,并通过局部搜索算法提升蚁群搜索的质量.算例实验结果表明该调度方法有效且具有较高的效率,可以降低能耗及生产总成本,具有实用价值.通过敏感性分析研究了设备可靠性离散程度、交付期松紧对于调度决策的影响,可为车间实际生产决策提供支持.     

基于神经网络和知识库的物料配送动态调度

为有效地解决汽车混流装配线中多载量小车物料配送的动态调度问题,提出基于知识库和神经网络的调度方法.首先,对汽车装配线物料配送的动态调度问题进行描述,建立以装配线产量和多载量小车的物料搬运距离作为衡量指标的目标函数.然后通过Plant Simulation软件生成针对汽车混流装配线的仿真数据并对神经网络模型进行离线训练,在实时阶段利用神经网络模型和知识库实现多载量小车最优调度规则的选取.实验结果表明:所提出的调度规则选取方法选择的调度规则大多为最优调度规则,以较低的调度规则计算复杂性确保了调度的实时性能,能够很好地应对动态环境的变化,从而有效提升了多载量小车的动态调度水平.     

汽车装配线电动车配送路径及换电站选址优化

考虑将电动小车用来进行基于厂内循环配送策略的汽车装配线的物料配送,提出了汽车装配线电动车配送路径及换电站选址问题,以最小化系统总成本为优化目标建立了数学规划模型.针对这一复杂的混合优化问题,对该问题的性质进行了分析,提出了两阶段动态规划算法获取小规模问题的最优解;对于中、大规模问题,通过种群分割技术并在Lévy飞行中融入深度邻域搜索算子构建了改进型离散布谷鸟算法.最后,进行了仿真实验,分别对比了两阶段动态规划算法,实数遗传算法及改进人工蜂群算法在解决该问题方面的性能,结果表明改进型离散布谷鸟算法的有效性以及在算法稳定性、搜索深度以及收敛性三个方面的较大优势.     

基于改进量子进化算法的末端配送任务动态分配模型

大多数物流快递企业的配送业务末端会按照固定的配送服务区进行配送任务分配,无法针对变化频繁、分布不均的动态配送需求进行合理的配送资源设置,造成了各个末端配送节点工作负荷不均衡的现象,并进一步导致了配送调度管理混乱等问题。针对末端配送任务分配问题建立了一种考虑配送成本,资源利用率以及工作量配比差异的配送任务分配模型,对量子进化算法进行改进。对此问题求解,提出采用量子群稳定度作为算法退出判定条件,来避免算法的早退与无效迭代问题,并引入量子变异与淘汰机制,加强了算法对可行解的搜索能力。实验结果表明,与按配送区进行分配的方案相比,算法给出的方案有效缓解了配送任务分配不均的现象,同时也有效降低了总体配送成本。相关模型和算法可以根据动态的配送需求合理地分配各个末端网点的配送任务,有助于配送业务的下一步配送路径优化和科学调度。     

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