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1.
车间作业调度遗传算法中的交叉算子研究   总被引:2,自引:0,他引:2  
针对车间作业调度遗传算法,在车间作业调度数学表达模型基础上,讨论车间作业调度遗传算法交叉算子的宏观设计与微观设计,提出了JSS(JobShopScheduling)交叉算子设计原则,并给出其应用结论,说明了交叉算子设计的有效性。  相似文献   

2.
绦纶车间空调自控系统张岐山,纪玉波,王晓虹,刘继舜TheAirConditioningAutomaticControlSystemintheTeryleneShop¥ZhangQishan;JiYubo;WangXiaohong;LiuJishun锦...  相似文献   

3.
该文提出了一种能高品质重建图象的记滤波器子带编码法,这种分解法具有实时性较好,通道错误不扩散,利于传输等特点,其重建图象与传统线性子带分解法相比,不会受振铃效应的影响。与ASD子带分解法相比,它的复杂度低,且采用了自适应压扩量化。通过与JPEG的比较显示,该方法在高保真压缩的情况下,其PSNR和视觉效果接近于JPEG,而在复杂度,抗通道错误鲁棒性方面则明显优于JPEG。  相似文献   

4.
文章提出一种新颖的方法一改进的基因表达式编程算法来求解作业车间调度问题。作业车间调度问题是许多实际生产调度问题的简化模型,基因表达式编程算法结合了遗传算法和遗传编程的优点,具有更强的解决问题能力,对基因表达式编程算法进行改进使其在作业车间调度问题的应用上更加有效;最后应用一个实例来验证提出方法的有效性。  相似文献   

5.
(1999年10月14日讯)SunMicrosystems公司和它的合作伙伴们在ISATeCh/1999大会上演示了JavaryM)技术是如何帮助制造企业在新的网络经济的大潮中将Internet“拉下来”,用在他们工厂车间的控制之中。在ISATeCh/贝999大会的突破性技术展示上,Sun的Java技术被用来在一个无线远程3COMPallnPilot器件上传送和显示工厂生产车间内的各种信息。这一概念验证性演示表明了Sun与Foxboro公司(位于麻塞诸萨州FOxboro市,是InvensysIn…  相似文献   

6.
JSP技术是由Sun公司提出的一种最新的开发动态网站的技术方案。JSP技术的基本原理与ASP技术非常相似,两者都提供在HTML代码中混合某种程序代码、由语言引擎解释执行程序代码的能力,从而为网站与用户之间的信息交互提供了方便有效的途径。在JSP下,在HTML代码中加入的java代码被JSP引擎编译成特殊的Servlet,并由Java虚拟机执行。因此,执行JSP代码需要在后台的Web服务器上安装JSP引擎。目前, Sun公司推出 T JavaServer WebDevelopmentKit(JSWDK…  相似文献   

7.
本文在并行join法ABJ^+的基础上提出一个基于Semijoin的改进算法SBABJ。我们在多台Sun工作站是实现了该算法,并对ABJ^+和SBABJ^+进行了能测试。算法分析和实验结果表明了并行join算法SBABJ^+优于ABJ^+算法。  相似文献   

8.
基于WWW的仿真软件JRTSS(Java-basedRealTimeSystemSimulator)以RTSS仿真软件为基础,保持其原有特色,并采用Java为编程语言,运行在Browser/Server环境下。JRTSS软件由三部分组成:仿真核心、建模程序与结果后处理程序。其中仿真核心运行在Server端,建模和结果后处理程序为JavaApplet,由用户的Browser下载并执行。JRTSS的系统模型是一个开放队列网络。通过在不同抽象层次对多个数据采集与处理系统、通信网络以及柔性制造系统的仿真与性能评价,证实JRTSS是一个用于系统开发的有力工具。  相似文献   

9.
DJMT是一个分布式的作业监控系统,本文主要介绍了DJMT作业监控系统的软件结构和实现技术,讨论了系统的作业运行机制,给出了相关算法,并描述了系统的重要功能,目前,DJMT已成功应用于数值天气预报业务系统中。  相似文献   

10.
从即日起,惠普消费产品部针对HP SJ5200 C、SJ-5300C、SJ6000C专业系列彩色扫描仪启动促销活动。凡是购买HPSJ5200C扫描仪,均可获得惠普公司赠送的时尚彩亮手表套装一套(包含 5种颜色)。购买 SJ5300C或 SJ6000C系列中的任意一款可获赠一部精美的无绳电话。据悉,这次活动是惠普公司特意在新千年为广大用户准备的一份厚礼,充分体现了惠普公司关爱中国广大用户,为消费者切身利益着想的宗旨。 HP SJ6000C专业系列彩色扫描仪是惠普公司真诚奉献给广大普通用户和网络用户最新的…  相似文献   

11.
Genetic neuro-scheduler for job shop scheduling   总被引:1,自引:0,他引:1  
This paper describes a hybrid approach between two new techniques, Genetic Algorithms and Artificial Neural Networks, for generating Job Shop Schedules (JSS) in a discrete manufacturing environment based on non-linear multi-criteria objective function. Genetic Algorithm (GA) is used as a search technique for an optimal schedule via a uniform randomly generated population of gene strings which represent alternative feasible schedules. GA propagates this specific gene population through a number of cycles or generations by implementing natural genetic mechanism (i.e. reproduction operator and crossover operator). It is important to design an appropriate format of genes for JSS problems. Specifically, gene strings should have a structure that imposes the most common restrictive constraint; a precedence constraint. The other is an Artificial Neural Network, which uses its highly connected-neuron network to perform as a multi-criteria evaluator. The basic idea is a neural network evaluator which maps a complex set of scheduling criteria (i.e. flowtime, lateness) to evaluate values provided by experienced experts. Once, the network is fully trained, it will be used as an evaluator to access the fitness or performance of those stimulated gene strings.

The proposed approach was prototyped and implemented on JSS problems based on different model sizes; namely small, medium, and large. The results are compared to the Shortest Proceesing Time heuristic used extensively in industry.  相似文献   


12.
An effective job shop scheduling (JSS) in the manufacturing industry is helpful to meet the production demand and reduce the production cost, and to improve the ability to compete in the ever increasing volatile market demanding multiple products. In this paper, a universal mathematical model of the JSS problem for apparel assembly process is constructed. The objective of this model is to minimize the total penalties of earliness and tardiness by deciding when to start each order’s production and how to assign the operations to machines (operators). A genetic optimization process is then presented to solve this model, in which a new chromosome representation, a heuristic initialization process and modified crossover and mutation operators are proposed. Three experiments using industrial data are illustrated to evaluate the performance of the proposed method. The experimental results demonstrate the effectiveness of the proposed algorithm to solve the JSS problem in a mixed- and multi-product assembly environment.  相似文献   

13.
纪怀猛  罗可 《计算机工程与应用》2006,42(36):187-190,232
在车间作业调度中,如何合理安排工件在机器上的加工顺序是企业生产过程研究的关键问题。针对传统优化方法只是对总体加工时间最少进行研究及遗传算法中过早收敛的缺点,通过在加入总体加工时间调节因子,提出了在保证总体在加工时间最短或相对最短的前提下保证某一工件交货期的免疫遗传车间作业调度方法。最后对著名的FT10×10标准问题进行了仿真实验,首先通过修改调节因子进行了结果比较,然后同其它算法的结果进行了比较。仿真结果说明了该方法的可行性和优越性。  相似文献   

14.
In the last 25 years, extensive research has been carried out addressing the flexible job shop scheduling (JSS) problem. A variety of techniques ranging from exact methods to hybrid techniques have been used in this research. The paper aims at presenting the development of flexible JSS and a consolidated survey of various techniques that have been employed since 1990 for problem resolution. The paper comprises evaluation of publications and research methods used in various research papers. Finally, conclusions are drawn based on performed survey results.  相似文献   

15.
Genetic algorithms and job shop scheduling   总被引:12,自引:0,他引:12  
We describe applications of Genetic Algorithms (GAs) to the Job Shop Scheduling (JSS) problem. More specifically, the task of generating inputs to the GA process for schedule optimization is addressed.

We believe GAs can be employed as an additional tool in the Computer Integrated Manufacturing (CIM) cycle. Our technique employs an extension to the Group Technology (GT) method for generating manufacturing process plans. It positions the GA scheduling process to receive outputs from both the automated process planning function and the order entry function. The GA scheduling process then passes its results to the factory floor in terms of optimal schedules.

An introduction to the GA process is discussed first. Then, an elementary n-task, one processor (machine) problem is provided to demonstrate the GA methodology in the JSS problem arena. The technique is then demonstrated on an n-task, two processor problem, and finally, the technique is generalized to the n-tasks on m-processors (serial) case.  相似文献   


16.
The coding efficiency of DCT-based standard video codecs is significantly improved by the use of skipped macroblocks. A similar concept is proposed for zerotree-based wavelet video coders. In a pyramidal wavelet transform, the wavelet coefficients are linked through spatial orientation trees. For each transformed frame, a method is proposed to identify those trees that are likely to be zerotrees throughout the coding process at a given bit budget. These trees are called the early-predicted zerotrees. These trees are then excluded from the subsequent quantisation and encoding processes. The tree classification is based on average energy of coefficients in the tree. The proposed technique is general and can be applied to any zerotree-based coding algorithm, but it is more advantageous to improve the performance of those zerotree-based video coding algorithms that use longer trees, such as virtual set partitioning in hierarchical trees (V-SPIHT). Simulation results demonstrate that the proposed technique can improve the performance of V-SPIHT-based video coder by up to 0.5 dB (on average) and can reduce the computational complexity by up to 80% (i.e. five times faster), for various test video sequences  相似文献   

17.
王博  孟亚峰 《计算机仿真》2020,37(1):307-310
针对胚胎电子细胞中基因存储硬件消耗较大的问题,提出了一种基于基因片段合并的胚胎电子细胞基因压缩编码方法。在编码过程中,把问题转化为图着色问题,采用遗传算法对基因中的填充位(X位)进行兼容赋值,从而把基因片段合并为基本兼容基因片段,实现基因压缩。利用概率论的知识对采用基因压缩方法实现基因存储的新型胚胎电子细胞结构的硬件消耗进行了理论分析。以实际电路作为目标电路进行仿真,结果表明,上述方法能有效地降低基因存储的硬件消耗。  相似文献   

18.
针对机动微波接力网组网及优化需要,提出一种基于双编码遗传算法(DMGA)的机动微波接力网组网方法.以网络价值最大化为优化目标,综合考虑节点价值、吸引系数、衰落概率等条件,实现了对每个节点接力设备的智能分配.通过研究网络价值与设备数的非线性关系,引入最优配置点的概念,为微波接力设备的编配数量提供量化依据.在遗传算法中使用邻接矩阵和邻接表的双编码法,其中邻接矩阵的优势是基因改变一定不会产生重复、自环链路,邻接表的优势是基因改变不会影响链路的总数.两种编码法在变异、交叉运算中交替运用,使约束条件与染色体形态特征优势匹配,避免了为满足约束进行的循环操作,提高了运算效率.仿真算例表明,双编码算法与单编码相比,计算时耗大大降低.  相似文献   

19.
车间调度问题是一个NP难题,而多工艺路线的车间调度问题更具有实际的研究意义。从生产实际出发,在分析了多工艺路线的车间调度问题一般特点的基础了,提出了一种禁忌-遗传的嵌套算法,该算法重点讨论了禁忌算法的设计思想及遗传算法中遗传算子的设计。仿真实例说明了算法的有效可行。  相似文献   

20.
结合小波变换的零搜索分形图象编码   总被引:1,自引:0,他引:1       下载免费PDF全文
为提高分形图象编码的质量,缩短编码时间,针对Monro在文献[1]中提出的零搜索分形图象编码方法,其恢复图象在存在的块效应的问题,提出了一种结合小波变换的多项式近似快速分形图象编码方法,该方法是利用各频带间能量分布不均衡的特性,构造一种结合小波分解的分形图象编码算法,首先对图象进行塔式离散正交小波变换,然后再对小波系数进行分形编码,实验结果表明,用该算法对图象进行编码,不仅使恢复图象的质量得到了较大的提高,而且编码时间仅用1.48s。  相似文献   

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