可回退抢占的设备驱动综合调度算法

针对基于拟关键路径法的综合调度算法按路径长度确定工序的调度次序,形成工序组间的并行处理, 使设备产生较多空闲时间的问题,提出可回退抢占的设备驱动综合调度算法. 该算法以每次工序加工结束作为一次可调度工序的寻找事件,若此时新出现的可调度工序具备抢占能力,则产生回退事 件进行重调度;若不产生回退事件,如果可调度工序唯一,则调度此工序;如果可调度工序不唯一, 选择父结点路径长的工序;如果父结点最长路径相同,选择用时长的工序. 由于该算法在调度工序时形成工序间的并行处理,缩小基于拟关键路径的综合调度算法形成的并行处理单位,进而减少加工过程中产生较多的设备空闲时间,提高设备利用率;同时,由于采用抢占式的回退调度策略,优先调度对调度结果有重要影响的长路径工序,达到对拟关键路径法的扬长避短,进一步提高设备利用率.     

基于剪枝分层的柔性加工车间调度算法

针对柔性作业车间调度中工序间存在的冗余调度次序约束关系问题和工序-设备间存在的多加工模式情况,提出基于剪枝分层的柔性加工车间调度算法.该算法首先用有向无环图表示工序及工序间的调度次序关系,采用剪枝法消除图中的冗余弧,采用分层法对图中结点分层;其次对加工模式进行分类,制定工序-设备预约策略和工序-设备预分配策略;最后,采用事件驱动策略,驱动时刻按所提出的柔性加工策略调度工序加工.理论分析和实例表明,所提出的算法具有较好的调度效果.     

两车间可调度工序均衡处理的综合调度算法

在两车间具备相同设备资源的生产条件时,需要考虑产品完成时间和车间之间工序移动次数尽可能少的问题。为此,提出两车间可调度工序均衡处理的综合调度算法。为减少单件复杂产品的完成时间,针对可调度工序的灵活性、并行性和两车间设备相同的条件,采用可调度工序车间均衡策略进行分组。为减少工序移动次数,按分组工序车间确定策略分配工序所在车间,并进行调度。实例结果表明,该算法可实现两车间综合调度,且产品完成时间和车间之间的工序移动次数较少。     

基于调度长路径的复杂产品综合调度算法

针对目前复杂产品加工和装配综合调度算法中考虑纵横双向调度优化时以横向为主,而忽略产品工序内在纵向约束对制造效率产生主要影响的问题,提出了以关键路径为主的纵横双向调度优化算法——基于调度长路径的复杂产品调度算法。该算法考虑了复杂产品树状工艺结构,根据优先级策略并结合调度长路径和长用时等策略来确定工序的调度次序。采用优先级策略可以兼顾其他分支上的同层工序;采用调度长路径策略是在兼顾其他分支的同时优先考虑了关键路径上工序对总加工时间的影响;采用长用时策略可以优先调度对加工时间影响大的工序。对已定调度次序的工序采用工序尽早加工的原则确定开始加工时间。实例表明,提出的调度策略简便可行且调度结果更优。     

基于逆序信号驱动的紧密衔接综合调度算法

针对以往综合调度中紧密衔接调度算法只能处理单一紧前工序的情况,使算法具有局限性问题,提出基于逆序信号驱动的紧密衔接综合调度算法.该算法先建立设备和调度2个子系统,并通过相互间传递的信号驱动逆序调度;对于紧密衔接工序组包含非单一紧前工序的情况,将紧密衔接工序组定义为一棵特殊的紧密衔接子树,采用逆序调度的方式自顶向下对紧密衔接问题求解;当信号驱动时刻存在多个可调度工序(组)时,按最大可并行性选择策略选择子节点关键路径长的工序(组)调度;对于可调度工序直接锁定该工序的加工时间段;对于可调度工序组,则按锁定紧密衔接工序组的前沿贪心策略锁定工序组的加工时间段.由于采用逆序调度和锁定紧密衔接工序组的前沿贪心策略,可使各紧密衔接工序组独立调度,实现紧密衔接紧前工序数无限制的综合调度.     

存在多工序同时结束的综合调度算法

针对实际生产中存在多工序同时结束约束条件的复杂产品综合调度问题, 提出了存在多工序同时结束的综合调度算法。该算法将具有同时结束约束条件的工序虚拟成一个工序组, 在提出虚拟工序组概念的基础上, 对虚拟工序组的前、后序标准工序, 采用拟关键路径法和首次适应调度算法确定工序的调度顺序和开始加工时间; 对虚拟工序组中工序采用预计晚结束优先策略和同时结束策略确定调度顺序和开始加工时间。实例表明, 所提出的综合调度算法不仅能在较低的复杂度时解决具有实际意义的工序间存在多工序同时结束约束的复杂产品综合调度问题, 而且调度效果更好。     

基于信号驱动的多批处理综合调度算法

针对以往综合调度中批处理调度算法只能处理2个工序的批量调度,进行批量调度的工序不能具有2个以上的紧前工序,使综合调度具有局限性问题,提出基于信号驱动的多批处理综合调度算法.该算法先建立设备和调度2个子系统,并通过相互间传递的信号驱动;为了预判断可批处理工序,将工序分为可调度工序和准可调度工序,采用组合策略将可批量处理的工序形成组合工序一同加工;当可调度工序超过设备批处理量时,按最大并行性选择策略选择调度;当准可调度工序成为批处理工序时,无需考虑前续工序对工序批处理的影响,即对批处理工序的紧前工序数无限制;循环以上可批处理工序判断,实现多批量处理.     

紧密衔接工序组联动的综合调度算法

由于现有的工序间存在紧密衔接条件的复杂产品综合调度问题, 采用的移动交换算法不易于软件实现且没有考虑移动工序后产生的连锁反应引起较高算法复杂度的问题, 提出将具有紧密衔接约束条件的工序组进行统一联动的综合调度算法.该算法利用将具有紧密衔接约束条件的工序分组的扩展加工工艺树模型, 按路径上属于工序组的工序个数多少确定所在路径工序组调度的次序, 通过降低对工序组的限制要求降低算法复杂度; 对于被调度工序组中各工序的前序工序, 按工序组中工序的加工顺序确定调度次序, 对某个工序的前序工序采用复杂度较低的拟关键路径法确定工序的调度次序; 调度完所有紧密衔接工序组后, 剩余的标准工序按拟关键路径法确定调度顺序; 采取工序首次适应调度算法调度标准工序和工序组, 由于工序组中工序采取按序紧密衔接的联动调度方式确定工序组的开始时间, 避免了二次调整, 进一步降低了算法复杂度. 分析和实例表明, 所提出的综合算法比以往算法复杂度更低, 调度结果更优且更易于实现.     

基于ACPM和BFSM的动态Job-Shop调度算法

通过对不同时刻开始加工的产品加工树的分解，可将产品加工工序分为具有惟一紧前、紧后的相关工序和独立工序．在对这两类工序研究分批综合应用拟关键路径法(ACPM)和最佳适应调度方法(BFSM)调度时，考虑了关键设备的工序紧凑性．通过分析与实例验证，所提出的调度方法对解决动态的Job—Shop调度问题不仅算法简练而且效果较好．     

工序间存在零等待约束的复杂产品调度研究

针对实际装配生产中工序之间存在零等待约束的复杂产品的调度问题, 提出了一种把存在零等待约束的工序虚拟成一个工序的方法. 该方法在提出复杂产品、标准工序、虚拟工序、零等待和扩展加工工艺树的概念基础上, 对扩展加工工艺树中的标准工序采用拟关键路径法和最佳适应调度的车间调度算法进行调度, 对虚拟工序采用移动交换算法在相应设备上分离调度, 将存在零等待约束的调度问题转化为存在虚拟工序的无零等待约束的调度问题. 实例表明, 所提出的调度算法能够较好地解决具有实际意义的工序间存在零等待约束的复杂产品的调度问题, 且易于实现.     

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。     

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     

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.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。