不确定加工时间下装配过程物料配送方法研究

文章针对加工时间不确定导致装配过程物料配送活动无法及时准确进行的问题,在实现装配过程信息实时采集与处理的前提下,提出一种基于实时信息驱动的物料配送模式;在此基础上,提出了物料配送系统,构建了系统的功能体系结构,并对系统实现的关键技术、物料配送动态决策系统进行了研究。将该物料配送方法应用于某发动机装配线物料配送系统,验证了方法的可行性和有效性。     

某摩托车企业发动机装配线物料配送仿真与优化

针对某新建摩托车发动机装配线投产前需验证原生产物料配送方案是否合理的问题,利用Witness仿真平台建立发动机装配线物料配送系统仿真模型,并对其进行仿真分析．发现原方案在装配线边初始存量及配送车辆数量方面均存在不合理之处．据此提出改进方案,并从装配线生产效率、装配线物料缺货率和配送车辆忙闲率等方面进行研究,确定一种最优改进方案,优化装配线边初始存量、调整配送车辆的数量,提高整个物流系统效率和降低企业生产物流成本．     

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.     

飞机制造物料配送技术研究与应用

针对飞机制造物料配送存在的问题，建立支持制造的物料配送任务模型，实现被动配送向主动配送模式转变。研究了物料配送作业流程，并在此基础上介绍了飞机制造物料配送管理信息系统软件功能及实现方案，实现精益敏捷配送。     

混流装配线车间内物料调度工位组划分优化法

基于准时制生产方式(JIT)提出对混流装配线进行工位组划分并安排配送车辆进行配送服务的优化方法.为保证混流装配线生产过程不发生缺料停产的情况,以配送车辆的承载能力与消耗工位配送时间窗为约束,配送车辆满载率与工位物料需求紧急程度为优化目标构建优化模型.运用遗传算法对模型进行求解,优化单个工作日总配送次数及配送车辆数量,给出配送工位组划分及车辆调度方案.最后,实例验证表明该方法具有可行性和有效性.     

考虑转移策略的物料配送和空箱回收集成优化

为了降低飞机移动装配线物料供给成本,构建了考虑转移策略的物料配送和空箱回收集成决策模型并设计了求解算法。在配送和回收任务调度的基础上引入了转移任务和线边物料存放的决策,以最小化小车出行成本为目标建立了数学模型并设计了一种以混沌差分进化算法为框架的双层迭代算法。算法上层对配送物料的分批进行搜索,综合考虑小车装载能力和线边空间约束,通过启发式算法对配送小车的发车时间和线边存储位置进行决策,结合转移小车的线边循环运作方式,设计了修复算子对调度和存储方案进行再优化;算法下层对无法即时装载的空箱组批进行搜索,使用转移调度算法进行解码。通过数值实验验证了该模型和算法的有效性。     

基手RFID的数字化制造车间物料实时配送方法

针对当前数字化制造车间物料配送问题,提出了一种基于射频识别技术的数字化制造车间物料实时优化配送新方法．对数字化制造车间资源进行精确布局,在采用RFID技术对物料配送小车进行实时位置跟踪的基础上,建立数字化制造车间物料配送路径优化模型并采用分支定界算法对模型进行解算,实现配送小车的物料配送路径优化与实时导航;开发了基于RFID的数字化制造车间物料配送系统,验证结果表明：所提出的方法能够有效解决数字化制造车间的物料配送路径优化与实时导航问题,为实现数字化制造车间的准时生产（JIT）奠定了基础．     

基于RFID的数字化制造车间物料实时配送方法

针对当前数字化制造车间物料配送问题,提出了一种基于射频识别技术的数字化制造车间物料实时优化配送新方法.对数字化制造车间资源进行精确布局,在采用RFID技术对物料配送小车进行实时位置跟踪的基础上,建立数字化制造车间物料配送路径优化模型并采用分支定界算法对模型进行解算,实现配送小车的物料配送路径优化与实时导航;开发了基于RFID的数字化制造车间物料配送系统,验证结果表明:所提出的方法能够有效解决数字化制造车间的物料配送路径优化与实时导航问题,为实现数字化制造车间的准时生产(JIT)奠定了基础.     

面向生产车间物料上线的配送时区方法研究

为解决制造企业车间在生产过程中物料上线时间不精准、配送数量不标准、生产效率低下等问题,从物料有效流动的角度,提出了一种结合横向时间维度与纵向数量维度的基于订单为需求信息的时间倒排方法来快速确定车间配送时区。从时间维度与数量维度的角度对车间物料需求进行研究,以时间倒排方法研究车间物料配送时区,通过建立生产排程模型与数学模型来对具体的生产开始时间进行计算,合理安排工作人员对线边物料进行配送,并对生产线边物料进行配送时区的划分,研发出生产车间物料配送系统。以某发动机制造企业生产100台为例,根据生产开始时间以40 min为区间划分出10个配送时区,得出每个时区具体的配送时间,实现精准的配送时间需求点,较好地解决了物料配送时间交接浪费的问题。表明对生产车间线边物料配送实行信息化管理,不但提高了生产效率,同时也有效的支持企业的生产,为后期解决供应商到货时间问题提供参考。     

基于工艺流程的物料配送BOM模型

通过对离散制造环境下,复杂产品装配过程中零部件成套性与产品BOM的分析研究,结合ERP系统中对制造BOM信息的管理和应用,建立基于工艺流程的产品配送BOM模型,作为物料配送的依据,实现装配车间生产计划执行前的零部件成套率控制,并实时记录装配过程的零部件和产品属性信息.     

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.     

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.     

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).     

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.