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1.
相对于单纯道路网络信息和历史经验交通信息,实时交通信息对于出行者出行决策具有更为重要的意义。随着实时交通信息获取手段的多样化和普及化,更富生命力的实时交通服务系统已经纳入应用日程。首先分析总结了公众对于实时动态交通信息的需求状况,将与导航和出行密切相关的实时道路交通信息分为交通事件和交通流信息两大类,对交通事件,根据其几何特征,进一步分为点事件、线事件、面事件和关系事件。基于J2ME/J2EEE软件开发架构,Post SQL与Post GIS的时空交通数据管理模式,研发了中心式的实时交通信息服务系统原型,并对典型的交通事件和交通流信息在移动终端模拟器进行了时空表达示例。  相似文献   

2.
当Beidou2系统正式提供区域性服务之际,为了应对目前山区客运安全的保障问题,提出一种基于Beidou/GPS双模卫星导航技术的山区长途客运车辆监测系统,对长途移动客车进行远程实时定位和监测。文中主要从系统的原理架构、系统硬件和GSM通信单元进行了设计,包括车载终端和地面客运监控服务中心两大部分。该系统既能弥补GPS系统在山区环境的使用局限性,又可以打破GPS系统垄断地位,实现车辆的自主导航、信息管理、远程监测与控制、客运路线监管、应急报警与保护等功能。  相似文献   

3.
In this paper, we attempt to present a constant due-date assignment policy in a multi-server multi-stage assembly system. This system is modelled as a queuing network, where new product orders are entered into the system according to a Poisson process. It is assumed that only one type of product is produced by the production system and multi-servers can be settled in each service station. Each operation of every work is operated at a devoted service station with only one of the servers located at a node of the network based on first come, first served (FCFS) discipline, while the processing times are independent random variables with exponential distributions. It is also assumed that the transport times between each pair of service stations are independent random variables with generalised Erlang distributions. Each product's end result has a penalty cost that is some linear function of its due date and its actual lead time. The due date is calculated by adding a constant to the time that the order enters into the system. Indeed, this constant value is decided at the beginning of the time horizon and is the constant lead time that a product might expect between the time of placing the order and the time of delivery. For computing the due date, we first convert the queuing network into a stochastic network with exponentially distributed arc lengths. Then, by constructing an appropriate finite-state continuous-time Markov model, a system of differential equations is created to find the manufacturing lead-time distribution for any particular product, analytically. Finally, the constant due date for delivery time is obtained by using a linear function of its due date and minimising the expected aggregate cost per product.  相似文献   

4.
《Information & Management》2019,56(4):507-525
One of the critical information systems that enables service resilience is the service configuration information system (CiS). The fundamental challenge for organisations is the effective designing and implementation of the CiS architecture. This paper addresses this important research problem and reports insights from a completed applied action design research (ADR) project in an Australian financial services organisation. This paper aims to provide guidance to researchers and practitioners contemplating ADR, rooted in the organisational context, for practice-oriented academia-industry collaborative research. This research also contributes in terms of the CiS reference architecture design knowledge and demonstrates the applicability of the ADR method.  相似文献   

5.
Assembly line balancing is important for the efficiency of the assembly process, however, a wide range of disruptions can break the current workload balance. Some researchers explored the task assignment plan for the assembly line balancing problem with the assumption that the assembly process is smooth with no disruption. Other researchers considered the impacts of disruptions, but they only explored the task re-assignment solutions for the assembly line re-balancing problem with the assumption that the re-balancing decision has been made already. There is limited literature exploring on-line adjustment solutions (layout adjustment and production rate adjustment) for an assembly line in a dynamic environment. This is because real-time monitoring of an assembly process was impossible in the past, and it is difficult to incorporate uncertainty factors into the balancing process because of the randomness and non-linearity of these factors. However, Industry 4.0 breaks the information barriers between different parts of an assembly line, since smart, connected products, which are enabled by advanced information and communication technology, can intelligently interact and communicate with each other and collect, process and produce information. Smart control of an assembly line becomes possible with the large amounts of real-time production data in the era of Industry 4.0, but there is little literature considering this new context. In this study, a fuzzy control system is developed to analyze the real-time information of an assembly line, with two types of fuzzy controllers in the fuzzy system. Type 1 fuzzy controller is used to determine whether the assembly line should be re-balanced to satisfy the demand, and type 2 fuzzy controller is used to adjust the production rate of each workstation in time to eliminate blockage and starvation, and increase the utilization of machines. Compared with three assembly lines without the proposed fuzzy control system, the assembly line with the fuzzy control system performs better, in terms of blockage ratio, starvation ratio and buffer level. Additionally, with the improvement of information transparency, the performance of an assembly line will be better. The research findings shed light on the smart control of the assembly process, and provide insights into the impacts of Industry 4.0 on assembly line balancing.  相似文献   

6.
在现代化大规模大批量的流水装配制造业中,数量众多的作用分配和多工位的合理安排使工位平衡问题显得更为突出。针对第一类工位平衡问题,即在给定的生产节拍下最小化工位数,首先分析了该问题并建立了数学模型,进而提出了一种基于改进遗传算法求解工位平衡问题的方法。该算法以焊接任务的操作顺序优先关系为约束前提,在初始种群的生产以及交叉和变异过程中保证了染色体解的可行性,同时在遗传算法的选择过程中考虑了具有相同工位数的最优作业方案的工时标准差,从而提高了算法的搜索效率和解的可靠性。最后通过实例求解验证了该算法的有效性。  相似文献   

7.
An exponential queuing network of two service stations is considered. The service rate at each station can either be fast or slow. A policy in which the service rate to be used at each station is specified as a function of the state of the system is investigated in order to minimize a given objective cost function. Howard's policy space algorithm is used to characterize the form of the optimal policy. Results show that the optimal policy is a simply connected one and of montone structure.  相似文献   

8.
基于硬件的物理式“电子导游”设备,使用不方便且维护困难,景区设备的出租价格游客不易接受,受限于硬件安装,不易升级等问题;其替代产品,即目前市场上的通用导航软件,存在偏远地点信息不全的问题,不能提供特定景区的特色服务的问题,以及和原有系统整合等问题.为了解决前述诸多弊端,针对某旅游景点的区域范围,提出一种基于智能手机平台+后端服务的整体解决方案,提供景区的位置服务、实时导航、景点搜索、旅游组团、线路规划、线路推荐、便捷服务等新型“智慧旅游”的具体实现方法,设计一个易用、灵活的前端应用App;同时将云端服务技术与后台服务分层设计相结合,将景区的传统旅游业务和日常随身携带的智能设备相关联,并设计了一个汇聚层,通过消息队列来管理、分发各种分层接口信息,从而使系统架构的运行效率、后期维护、扩展性得到了极大的保证.通过具体的工程实践,验证了该系统的有效性和实际运行效果.  相似文献   

9.
该文是通过对南昌某双离合器变速箱装配企业的管理制度和业务流程的分析和研究,设计了一套设备管理信息系统,该系统是以OPC、UDP远程通讯技术为基础,通过计算机和PLC的信息交互,实现了对变速箱装配线各个工位的设备工作状态进行实时监控,显示现场装配设备的故障报警信息、维护保养信息等。同时采集并存储装配过程中的重要数据,为后续的SPC、OEE分析提供了依据。该系统已在装配现场应用,并满足了生产要求。  相似文献   

10.
We consider an assembly line problem that occurs in various kinds of production automation. Our original motivation lies in the automated manufacturing of PC boards. The assembly line has to process a (potentially infinite) number of identical workpieces in a cyclic fashion. In contrast to common variants of assembly line scheduling, the forward steps are variable and may be smaller than the distance of two stations. Therefore, each station may process parts of several workpieces at the same time, and parts of a workpiece may be processed by several stations at the same time. The throughput rate is determined by the number of (cyclic) forward steps, the offsets of the individual forward steps, and the distribution of jobs over the stationary stages between the forward steps. The number of forward steps as well as the offsets are part of the output. However, no matter whether they are part of the input or the output, the optimal assignment of the jobs to the stationary stages is NP-hard.  相似文献   

11.
周瑞华 《现代计算机》2014,(5):54-56,62
导航与位置服务主要是基于导航定位、移动通信、数字地图等技术,建立人、事、物、地在统一时空基准下的位置与时间标签及其关联.为公众提供随时获知所关注目标的位置及位置关联信息的服务,数据是导航与位置服务的基础。而大数据的出现为导航与位置服务产业带来新的发展方向,从概括导航与位置服务中的大数据着手,分析大数据时代的到来给导航与位置服务带来的机遇与挑战,为导航与位置服务产业发展提供指导。  相似文献   

12.
When demand structure or production technology changes, a mixed-model assembly line (MAL) may have to be reconfigured to improve its efficiency in the new production environment. In this paper, we address the rebalancing problem for a MAL with seasonal demands. The rebalancing problem concerns how to reassign assembly tasks and operators to candidate stations under the constraint of a given cycle time. The objectives are to minimize the number of stations, workload variation at each station for different models, and rebalancing cost. A multi-objective genetic algorithm (moGA) is proposed to solve this problem. The genetic algorithm (GA) uses a partial representation technique, where only a part of the decision information about a candidate solution is expressed in the chromosome and the rest is computed optimally. A non-dominated ranking method is used to evaluate the fitness of each chromosome. A local search procedure is developed to enhance the search ability of moGA. The performance of moGA is tested on 23 reprehensive problems and the obtained results are compared with those by other authors.  相似文献   

13.
Balancing the workloads of workstations is key to the efficiency of an assembly line. However, the initial balance can be broken by the changing processing abilities of machines because of machine degradation, and at some point, re-balancing of the line is inevitable. Nevertheless, the impacts of unexpected events on assembly line re-balancing are always ignored. With the advanced sensor technologies and Internet of Things, the machine degradation process can be monitored continuously, and condition-based maintenance can be implemented to improve the health state of each machine. With the technology of robotic process automation, workflows of the assembly process can be smoothed and workstations can work autonomously together. A higher level of process automation can be achieved. Real-time information of the processing abilities of machines will bring new opportunities for automated workload balance via adaptive decision-making. In this study, a fuzzy control system is developed to make real-time decisions to balance the workloads based on the processing abilities of workstations, given the policy of condition-based maintenance. Fuzzy controllers are used to decide whether to re-balance the assembly line and how to adjust the production rate of each workstation. The numerical experiments show that the buffer level of the assembly line with the proposed fuzzy control system is lower than that of the assembly line without any control system and the buffer level of the assembly line with another control system is the lowest. The demand can always be satisfied by assembly lines except the one with another control system since there is too much production loss sacrificed for the low buffer level. The sensitivity analysis of the control performance to the parameter settings is also conducted. Thus, the effectiveness of the proposed fuzzy control system is demonstrated, and intelligent automation can improve the performance of the assembly process by the fuzzy control system since real-time information of the assembly line can be used for adaptive decision-making.  相似文献   

14.
射频识别在多品种小批量生产管理中的应用研究   总被引:1,自引:0,他引:1       下载免费PDF全文
针对多品种小批量生产环境下,生产过程难以实现精准管理的问题,采用射频识别标签标识车间重要生产对象,关键应用管控点部署交互式作业控制终端,自动、实时、准确、详细地获取车间物理环境的信息。在此基础上,构建相应的生产管理系统的体系结构和集成化运行模式。研究多源异构实时生产信息融合技术和基于组件技术的可重构生产管理系统实现方法。该系统已成功应用于重庆某企业摩托车装配线,取得了良好的应用效果。  相似文献   

15.
基于语义地图导航的智能化服务机器人系统,以搭载深度相机和二维激光雷达的差分轮智能车的形式呈现。系统以树莓派作为主控制器,利用OpenCR控制电机驱动和辅助驾驶传感器,通过ROS机器人操作系统将机器人控制器、智能信息处理模块和各类传感器融合成一个有机整体。所构建的机器人系统在服务过程中,通过感知周围环境、收集数据完成静态、动态物体的辨识,然后结合二维地图数据完成目标检测和语义地图的构建。为了提升系统智能化程度,配合深度推理神经计算棒,并结合Mobile Net网络架构下的SSD目标实时检测算法,提高了视觉感知的实时程度以及准确性。  相似文献   

16.
Cities are being equipped with multiple information systems to provide public services for city officials, officers, citizens, and tourists. There have been concerns with efficient service implementation and provision, e.g., data islands and function overlaps between systems and applications. Service-oriented portals are efficient at facilitating information sharing and collaborative work between city systems and users. The goal of this research is to make cities responsive, agile and to provide composite services efficiently and cost efficiently. A service-oriented framework for city portals is proposed to design, integrate and streamline city systems and applications. A model driven collaborative development platform of the proposed framework was developed for service-oriented digital portals. The architecture and implementation issues of the platform are discussed. The service identification policies are discussed within the framework. A case study has been developed and evaluated on the platform to provide a composite service, i.e., a traffic search service on a city portal.  相似文献   

17.
Internet of Things (IoT) has radically transformed the world; currently, every device can be connected to the Internet and provide valuable information for decision-making. In spite of the fast evolution of technologies accompanying the grow of IoT, we are still faced with the challenge of providing a service oriented architecture, which facilitates the inclusion of data coming together from several IoT devices, data delivery among a system's agents, real-time data processing and service provision to users. Furthermore, context-aware data processing and architectures still pose a challenge, in spite of being key requirements in order to get stronger IoT architectures. To face this challenge, we propose a COLLaborative ConText Aware Service Oriented Architecture (COLLECT), which facilitates both the integration of IoT heterogeneous domain context data — through the use of a light message broker — and easy data delivery among several agents and collaborative participants in the system — making use of an enterprise service bus —. In addition, this architecture provides real-time data processing thanks to the use of a complex event processing engine as well as services and intelligent decision-making procedures to users according to the needs of the domain in question. As a result, COLLECT has a great impact on context-aware decentralized and collaborative reasoning for IoT, promoting context-aware intelligent decision making in such scope. Since context-awareness is key for a wide range of recommender and intelligent systems, the presented novel solution improves decision making in a large number of fields where such systems require to promptly process a variety of ubiquitous collaborative and context-aware data.  相似文献   

18.
19.
电子装配行业的MES体系结构及技术实现   总被引:3,自引:0,他引:3       下载免费PDF全文
吴立辉  张洁 《计算机工程》2009,35(5):12-14,1
针对电子装配行业的特点和制造执行系统(MES)的需求,采用基于SOA的设计方法和理念,提出基于Web服务的MES软件体系结构,建立基于工作流的电子装配过程实时可视化、实时生产排程、实时生产过程跟踪技术框架。提出基于WebServices技术和J2EE平台的软件体系结构技术实现框架。开发的MES系统应用在某SMT车间,证明该系统具有较好的实时、可配置、可重构、可集成性能。  相似文献   

20.
We consider a production system in a general configuration with a new control strategy: the push mechanism for the part transport and the kanban technique for the work-in-process (WIP). The production system is composed of many stations such as an entrance station, a set of work stations, a central station, and an exit station, that are arranged in a general configuration. The push mechanism is followed for transporting a part from a station to a destination station. The kanban technique is adopted for controlling the WIP in a work station. The production system is modeled by a closed queuing network in a general configuration with a Markov part sending mechanism and a machine no blocking (MNB) technique. An optimal part sending policy that maximizes the expected system throughput is formulated into a long run average semi-Markov decision process. Three solution approaches are developed for obtaining optimal or suboptimal solutions. Numerical examples are given to evaluate the quality of the solutions obtained by the solution approaches  相似文献   

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