启发式算法在计划排产中的应用

面向单件生产的车间生产作业计划排产问题一直是研究的热点和难点。文中结合汽车模具行业生产管理特点和实际生产状况,针对有限能力排产问题,提出了具体的排产方法和步骤,并建立了基于启发式算法的车间作业优化排序函数。上述研究成果将提高排产的有效性,解决我国单件生产企业在计划排产中普遍存在的问题,对于加强车间生产控制和管理起到促进作用。     

重型机械生产MRP算法改进及其应用

针对重型机械生产模式,提出了一种“计划压缩”MRP改进算法,该算法继承了MRP的基本思想,根据物料清单将主生产计划分解成零部件的生产计划和原材料、采购件的采购计划,并在此基础上对MRP算法进行改进,根据交货期,利用压缩提前期倒排计划,将生产计划排到工序级。经实例证明采用这种MRP算法,增加了排产的灵活性,提高了排产效率,有效地减少了订单拖延的情况。     

线性规划在车间动态排产中的应用与实现

本文基于线性规划思想提出了一套快速实现车间最优动态排产的方法,该方法在确保订单不延迟的情况下,能够有效合理地安排生产过程。本文通过对车间工序建立数学模型,应用改进的算法对所有订单进行评估,确定所有订单的每道工序的最早发生时间和最迟发生时间,从而实现车间最优动态排产。本算法适用于严格按订单组织生产的企业,企业可以利用该算法对订单进行评估,确定是否可以接受该订单以及订单最佳投产时间。本文提出的方法已经在四川省某制造业信息化示范企业投入实际应用。     

基于价值密度的Job-shop车间生产计划控制

针对离散型生产中工艺路线不确定,工时不准确,加工中变化快,物流速度快的生产现状,提出计划期内生产的价值作为追求目标,排产不必追求任务完成的时间节点,而应制定投产的顺序,以保证企业在单位时间内实现的价值最高,即价值密度作为排产依据。确定车间的瓶颈设备之后,通过排产保证该设备前面有足够的零部件等待加工,将人力资源和设备混合排产,在动态中实现任务计划的改变、时间窗口的锁定或拒绝,兼顾了订单的重要性和交货时间,发挥出了车间设备的最大能力。每个任务的计算量仅有一次,特别适合动态中的快速排产。     

遗传算法在刹车片生产计划排产中的应用与实践

生产计划的排产问题是影响车间生产效率的主要因素之一.合理的排产计划能够高效地使用车间现有的生产资源,提高车间生产能力,降低生产成本.本文首先分析了刹车片生产运行状况,针对热压成型生产车间的多品种变批次生产模式,建立了排产数学模型;其次,设计了一种联合均值-遗传算法,对热压成型车间的排产数学模型进行求解;最后通过实验仿真,对本文设计的算法进行验证,实验结果表明联合均值-遗传算法能够很好的解决当前刹车片生产计划的排产问题.     

启发式算法在计划排产中的应用

面向单件生产的车间生产作业计划排产问题一直是研究的热点和难点.文中结合汽车模具行业生产管理特点和实际生产状况,针对有限能力排产问题,提出了具体的排产方法和步骤,并建立了基于启发式算法的车间作业优化排序函数.上述研究成果将提高排产的有效性,解决我国单件生产企业在计划排产中普遍存在的问题,对于加强车间生产控制和管理起到促进作用.     

基于模拟退火算法的整经排产系统

对于织造企业来说,单一品种且大规模生产模式已无法匹配日益丰富的需求。在一个生产多种不同型号产品的整经车间中,需要投入大量人力频繁地更换经轴,从而增加了生产开销以及生产成本,同时也导致设备利用率的下降。目前整经车间仍采用人工排产,由于人工经验的不确定性、人工排产的主观性以及问题的复杂性,实现最优调度计划十分困难。因而,织造企业需要更有效的方法来搭建更优秀的排产计划,减少开轴数和加工时间,降低设备经轴的切换频率以提高生产效率。本文基于模拟退火算法搭建织造企业的整经生产排产系统,以期能解决多品种小批量生产模式最优化排产问题。     

ERP系统下的型材生产计划管理

介绍了炼钢企业实行ERP信息化后型材生产计划的管理,从订单的签订、排产、作业计划的执行和跟踪等功能都能够在ERP系统里完成,保证了每一条生产信息的完整性,使每一条订单形成后能够跟踪到每个生产工序,查询起来准确、快捷,满足客户的需求。     

面向装配的多agent排产模型研究

拖期罚金带来的成本问题使中小规模离散制造企业在竞争中面临巨大压力.为此,采用多agent技术设计面向装配的三层排产框架模型;利用多agent的自治和协同,结合经验规则,将复杂的大规模排产逐层分解,转化为可用算法优化的子问题,再自底向上归并更新,迭代寻优完成生产排产,并可依计划执行情况进行动态调度.以合作企业凹印机历史订单数据进行排产仿真,结果表明,通过对设备空闲时间分布的有效管理,此三层模型能够有效解决订单拖期问题,对中小企业的成本控制具有重要意义.     

实施ERP能力计划数据研究和问题改善

在目前离散型制造企业实施ERP普遍存在基础数据不完整的前提下，进行了从技术统计得出能力计划关键数据的研究。提出了在MRP-Ⅱ系统中增加生产周期统计模块，利用从车间底层管理系统采集的设备状态数据，经分析后取得统计值取代原MRP-Ⅱ系统固定生产周期的没置，并得出工作中心实际利用率作为下阶段评价生产能力的依据，由此改善MRP-Ⅱ物料计划中的能力管理流程。并进一步提出采用流量图作为分析工具，为企业真正实行按动态调整的有限能力排产方式提供了可行的解决方案。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.