首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
楼宇自动化系统对大楼的中央空调系统、通风系统、给排水系统、照明系统、变配电系统、照明系统、电梯系统进行监控。本文通过广州某高尚住宅的楼宇自动化系统设计,介绍楼宇智能化系统中的楼宇自动化的设计。  相似文献   

2.
依据珠海120系统的实际研制、开发,介绍了GPS系统在汽车监控领域的一种应用──车辆自动追踪系统,重点介绍了系统的整体结构、系统原理、系统功能、系统的优点及系统的技术指标。  相似文献   

3.
针对国内人们对家居安防系统的需求,改进当前已存在的家居安防系统,提出了基于嵌入式Linux网关的开源远程家居安防系统。本系统改进了现存系统,使用新兴的NB_IOT技术作为远程传输技术,使用开源语言Python在嵌入式Linux系统中搭建网关,使系统具备开源特点。本系统底层使用ZigBee技术降低产品功耗,同时,系统网关可以实现简单的警情预处理。尽管本系统开源,但本系统继承了Linux系统权限管理模式的优点,系统更加安全。  相似文献   

4.
非线性系统控制的逆系统方法(Ⅰ)   总被引:7,自引:0,他引:7  
李春文  苗原 《控制与决策》1997,12(5):529-535
介绍非线性系统控制的逆系统方法及相应的单一非线性系统的控制理论。包括:逆系统方法的基本概念和设计原理,单变量系统α阶积分逆的设计方法,连续单变量系统的系统的控制,逆系统在一类分布参数系统和离散时间系统上的推广示例。  相似文献   

5.
论高级Petri网系统的等价谱系   总被引:7,自引:0,他引:7  
高级网系统简洁明了,在Petri网系统的应用中是非常有效的.本文讨论了高级网系统的等价变换,提出了高级网系统的两种极端形式——最高网系统和最低网系统,并且证明了所有高级网系统都可以构造与其等价的最高网系统和最低网系统.此外,还提出了高级网系统的等价谱系,旨在从理论上分析清楚高级网系统的本质.  相似文献   

6.
在系统与系统的交互过程中,很多系统都无法实现系统与系统间操作的实时交互性以及数据的同步性,而需要通过接口系统采用跑批的方式来实现系统间数据的同步性。该文介绍一种实时交互的组件――Link-easy的实现,该组件可以解决系统与系统之间的实时交互问题。  相似文献   

7.
逆向工程研究与发展   总被引:14,自引:0,他引:14  
一、引言由于多年的运行历史,遗产系统包含了企业的众多知识,包括系统需求、设计决策和业务规则。为了充分有效地利用这些有用资产,遗产系统持续性演化变得十分重要。再工程是将遗产系统转为易演化系统的良好途径之一。再工程在检查现有系统基础上,修改系统并组装成新的形式。作为工程的问题,再工程涉及对问题的理解,也即,理解系统的当前状态、未来状态和从当前状态演化到未来状态的途径。系统理解基于系统对象、系统专家和系统历史。系统对象包括源代码、手册和运行系统;系统专家包括开发者、维护者和用户;系统历史则包  相似文献   

8.
张苓 《微计算机信息》2007,23(26):264-265,35
本文简要介绍足球机器人系统的四大功能模块即视觉系统、决策系统、通信系统和车体系统。然后对足球机器人的各个功能系统分别提出其实验性设计,以实现每个功能系统的多视角实验平台,该功能系统的实验平台除对足球机器人系统进行功能研究外,还可用于智能控制的教学和研究。  相似文献   

9.
基于Web Service的医疗保险系统的设计与实现   总被引:6,自引:0,他引:6  
医疗保险是社会保障体系的一个重要环节,医疗保险系统是贯彻相关政策的直接载体.如何与社会保障系统中的其他系统以及社会保障系统外的其他系统相互集成和数据共享成为医疗保险系统应用的一大挑战.本文利用Web服务的体系结构和它的关键技术,设计了基于Web服务的医疗保险应用系统,解决了医疗保险应用系统与其他系统的相互集成问题和系统间数据共享问题.  相似文献   

10.
80年代初,酒店计算机应用仅局限于前台系统和后台系统,采用的是独立的网络结构.进入90年代,特别是近几年,新的运用领域不断出现,据初步估算,至少有10个左右的小网络在酒店不同的部门相继投入使用,它们包括:前台系统、后台系统、办公自动化系统、VOD系统、交换机系统、餐厅收款(POS)系统、因特网系统、门锁系统、消防系统、监控系统等等.  相似文献   

11.
Most previous studies on machining optimization focused on aspects related to machining efficiency and economics, without accounting for environmental considerations. Higher cutting speed is usually desirable to maximize machining productivity, but this requires a high power load peak. In Taiwan, electricity prices rise sharply if instantaneous power demand exceeds contract capacity. Many studies over the previous decades have examined production scheduling problems. However, most such studies focused on well-defined jobs with known processing times. In addition, traditional sequencing and scheduling models focus primarily on economic objectives and largely disregard environmental issues raised by production scheduling problems. This study investigates a parallel machine scheduling problem for a manufacturing system with a bounded power demand peak. The challenge is to simultaneously determine proper cutting conditions for various jobs and assign them to machines for processing under the condition that power consumption never exceed the electricity load limit. A two-stage heuristic approach is proposed to solve the parallel machine scheduling problem with the goal of minimizing makespan. The heuristic performance is tested by distributing 20 jobs over 3 machines with four possible cutting parameter settings.  相似文献   

12.
Using unrelated parallel machine scheduling to minimize the total earliness and tardiness of jobs with distinct due dates is a nondeterministic polynomial-hard problem. Delayed customer orders may result in penalties and reduce customer satisfaction. On the other hand, early completion creates inventory storage costs, which increase the total cost. Although parallel machines can increase productivity, machine assignments also increase the complexity of production. Therefore, the challenge in parallel machine scheduling is to dynamically adjust the machine assignment to complete the job within the shortest possible time. In this paper, we address an unrelated parallel machine scheduling problem for jobs with distinct due dates and dedicated machines. The objective is to dynamically allocate jobs to unrelated parallel machines in order to minimize the total earliness and tardiness time. We formulate the problem as a mixed integer linear programming (MILP) model and develop a modified genetic algorithm (GA) with a distributed release time control (GARTC) mechanism to obtain the near-optimal solution. A preliminary computational study indicates that the developed GARTC not only provides good quality solutions within a reasonable amount of time, but also outperforms the MILP model, a classic GA and heuristic approaches described in the literature.  相似文献   

13.
We consider an extension of classic parallel machine scheduling where a set of jobs is scheduled on identical parallel machines and an undirected conflict graph is part of the input. Each node in the graph represents a job, and an edge implies that its two jobs are conflicting, meaning that they cannot be scheduled on the same machine. The goal is to find an assignment of the jobs to the machines such that the maximum completion time (makespan) is minimized. We present an exact algorithm based on branch and price that combines methods from bin packing, scheduling, and graph coloring, with appropriate modifications. The algorithm has a good computational performance even for parallel machine scheduling without conflicting jobs.  相似文献   

14.
This paper is about scheduling parallel jobs, i.e. which can be executed on more than one machine at the same time. Malleable jobs is a special class of parallel jobs. The number of machines a malleable job is executed on may change during its execution.In this work, we consider the NP-hard problem of scheduling malleable jobs to minimize the total weighted completion time (or mean weighted flow time). For this problem, we introduce the class of “ascending” schedules in which, for each job, the number of machines assigned to it cannot decrease over time while this job is being processed.We prove that, under a natural assumption on the processing time functions of jobs, the set of ascending schedules is dominant for the problem. This result can be used to reduce the search space while looking for an optimal solution.  相似文献   

15.
The problem of scheduling a set of trains traveling through a given railway network consisting of single tracks, sidings and stations is considered. For every train a fixed route and travel times, an earliest departure time at the origin and a desired arrival time at the destination are given. A feasible schedule has to be determined which minimizes total tardiness of all trains at their destinations. This train scheduling problem is modeled as a job-shop scheduling problem with blocking constraints, where jobs represent trains and machines constitute tracks or track sections. Four MIP formulations without time-indexed variables are developed based on two different transformation approaches of parallel tracks and two different types of decision variables leading to job-shop scheduling problems with or without routing flexibility. A computational study is made on hard instances with up to 20 jobs and 11 machines to compare the MIP models in terms of total tardiness values, formulation size and computation time.  相似文献   

16.
Production scheduling seeks optimal combination of short manufacturing time, stable inventory, balanced human and machine utilization rate, and short average customer waiting time. Since the problem in general has been proven as NP-hard, we focus on suboptimal scheduling solutions for parallel flow shop machines where jobs are queued in a bottleneck stage. A Genetic Algorithm with Sub-indexed Partitioning genes (GASP) is proposed to allow more flexible job assignments to machines. Our fitness function considers tardiness, earliness, and utilization rate related variable costs to reflect real requirements. A premature convergence bounce is added to traditional genetic algorithms to increase permutation diversity. Finally, a production scheduling system for an electronic plant based on GASP is implemented and illustrated through real production data. The proposed GASP has demonstrated the following advantages: (1) the solutions from GASP are better and with smaller deviations than those from heuristic rules and genetic algorithms with identical partitioning genes; (2) the added premature convergence bounce helps obtain better solutions with smaller deviations; and (3) the consideration of variable costs in the fitness function helps achieve better performance indicators.  相似文献   

17.
This paper presents several search heuristics and their performance in batch scheduling of parallel, unrelated machines. Identical or similar jobs are typically processed in batches in order to decrease setup times and/or processing times. The problem accounts for allotting batched work parts into unrelated parallel machines, where each batch consists of a fixed number of jobs. Some batches may contain different jobs but all jobs within each batch should have an identical processing time and a common due date. Processing time of each job of a batch is determined according to the machine group as well as the batch group to which the job belongs. Major or minor setup times are required between two subsequent batches depending on batch sequence but are independent of machines. The objective of our study is to minimize the total weighted tardiness for the unrelated parallel machine scheduling. Four search heuristics are proposed to address the problem, namely (1) the earliest weighted due date, (2) the shortest weighted processing time, (3) the two-level batch scheduling heuristic, and (4) the simulated annealing method. These proposed local search heuristics are tested through computational experiments with data from dicing operations of a compound semiconductor manufacturing facility.  相似文献   

18.
The objective of this paper is a study of minimizing the maximum completion time min F max, or cycle time of the last job of a given family of jobs using flow shop heuristic scheduling techniques. Three methods are presented: minimize idle time (MIT); Campbell, Dudek and Smith (CDS); and Palmer. An example problem with ten jobs and five machines is used to compare results of these methods. A deterministic t-timed colored Petri net model has been developed for scheduling problem. An execution of the deterministic timed Petri net allows to compute performance measures by applying graph traversing algorithms starting from initial global state and going into a desirable final state(s) of the production system. The objective of the job scheduling policy is minimizing the cycle time of the last job scheduled in the pipeline of a given family of jobs. Three heuristic scheduling methods have been implemented. First, a sub-optimal sequence of jobs to be scheduled is generated. Second, a Petri net-based simulator with graphical user interface to monitor execution of the sequence of tasks on machines is dynamically designed. A deterministic t-timed colored Petri net model has been developed and implemented for flexible manufacturing systems (FMS). An execution of the deterministic timed Petri net into a reachability graph allows to compute performance measures by applying graph traversing algorithms starting from initial global state to a desirable final state(s) of the production system.  相似文献   

19.
This study presents a novel artificial immune system for solving a multiobjective scheduling problem on parallel machines (MOSP), which has the following characteristics: (1) parallel machines are nonidentical, (2) the type of jobs processed on each machine can be restricted, and (3) the multiobjective scheduling problem includes minimizing the maximum completion time among all the machines (makespan) and minimizing the total earliness/tardiness penalty of all the jobs. In this proposed algorithm, the cells are represented by a vector group, and a local search algorithm is incorporated to facilitate the exploitation of the search space. Specially, a new diversity technique is proposed to preserve the diversity of the population and enhance the exploration of the solution space. Simulation results show the proposed algorithm outperforms the vector immune genetic algorithm (VIGA).  相似文献   

20.
混合遗传算法在柔性系统动态调度中的应用研究   总被引:6,自引:1,他引:5  
本文研究了柔性制造系统实时生产环境下的动态调度问题.提出了基于动态数据库技术的动态调 度系统的框架结构.动态数据库中存储着问题的数据结构,包含工件相关类与机器相关类信息.动态数据库能 够随着生产的进行及时进行更新.扰动发生后,遗传算法根据动态数据库所提供的更新后的调度任务数据,快 速产生新的优化调度方案.通过在遗传算法中嵌入约束解决机制确保遗传算法适应约束的能力,从而提高算 法的收敛速度与精度.仿真实验证实了方案的有效性.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号