一类区间系数线性双层规划问题的遗传算法

针对一类上层目标函数带区间系数的线性双层规划问题,提出了一种基于双适应度函数评估的遗传算法(GA)。该算法的特点是在一次运算中同时获得最好最优解和最差最优解。首先,利用双层规划约束域的顶点进行个体编码,以上层目标函数中系数的上下端点构造两个适应度函数;其次,利用适应度函数排序种群中的个体,并按从好到差的次序验证个体的下层最优性,直到找到一个可行个体;最后,在算法运行中更新找到的可行个体。通过对4个算例的仿真实验,表明算法是可行且有效的。     

一类区间系数线性双层规划问题的遗传算法

针对一类上层目标函数带区间系数的线性双层规划问题,提出了一种基于双适应度函数评估的遗传算法(GA)。该算法的特点是在一次运算中同时获得最好最优解和最差最优解。首先,利用双层规划约束域的顶点进行个体编码,以上层目标函数中系数的上下端点构造两个适应度函数;其次,利用适应度函数排序种群中的个体,并按从好到差的次序验证个体的下层最优性,直到找到一个可行个体;最后,在算法运行中更新找到的可行个体。通过对4个算例的仿真实验,表明算法是可行且有效的。     

一类区间系数二次双层规划问题的遗传算法

针对上下层均含区间系数的二次双层规划,提出了一种基于两个适应度评估的遗传算法。将下层目标系数区间作为遗传算法的搜索空间,对于每一个确定的个体,下层问题不含区间系数;利用二次规划的最优性条件,将个体所对应的问题转化为两个确定的二次规划;利用基枚举方法求解这两个二次规划问题,相应的最优值作为个体的两个适应度。算法通过两个适应度的比较,获得问题的最好最优解和最差最优解。数值仿真结果表明,该算法是可行有效的。     

多下层分式双层规划问题的改进遗传算法

针对一类具有多个线性下层问题的分式双层规划, 提出一种基于新编码方式的遗传算法。 首先,利用对偶理论,将问题化为单层非线性规划;接着,利用下层对偶问题的可行基编码,针对任意编码个体,解出对偶变量值,使得单层规划变为线性分式规划;最后,求解产生的线性分式规划,其目标值作为个体的适应度值。 这种编码方式及适应度的计算有效提高了遗传算法的效率。 通过对4个算例的计算,验证了算法的有效性。     

基于近似技术的双层规划进化算法

双层规划涉及上层和下层两个最优化问题,上层规划问题的约束域由下层规划问题隐式确定,双层优化以上层目标为主,而下层目标在下层变量方面必须达到最优。双层规划问题的递阶结构使其具有很高的计算复杂度,特别是频繁计算下层问题会累计很大的计算量。为了有效求解这类问题,提出一种基于近似技术的进化算法。首先,采取多种群协同进化,分别利用交叉和变异算子平衡算法的开采和勘探能力;其次,基于灵敏度分析理论,设计了新个体的近似评价方式以减少算法的下层求解次数。一个算例的近似效果演示结果表明,由近似技术得到的近似后代个体与精确后代个体的位置大部分是重合的。除此之外,在10个常用算例上的结果显示,所提算法比多值映射算法获得了更好的最优解;并且根据CPU时间比较,说明近似技术有效地提高了找到最优解的速度,减少了运行时间,验证了所提算法采取的近似技术的有效性。     

双层规划的改进混合布谷鸟搜索量子行为粒子群优化算法

为解决粒子群优化（PSO）算法求解双层规划问题时易陷入局部最优解的问题,提出了一种基于模拟退火（SA）Metropolis准则的改进混合布谷鸟搜索量子行为粒子群优化（ICSQPSO）算法。首先,该混合算法引入SA算法中的Metropolis准则,在求解过程中既能接受好解也能以一定的概率接受坏解,增强全局寻优能力;接着,为布谷鸟搜索算法设计一种改进动态步长Lévy飞行,以保持粒子群在优化过程中较高的多样性,保证搜索广度;最后,利用布谷鸟搜索算法中的偏好随机游走机制帮助粒子跳出局部最优解。通过对13个涵盖非线性规划、分式规划、多个下层规划的双层规划实例的数值实验,结果表明：ICSQPSO算法所得12个双层规划的目标函数最优值显著优于对比算法,只有1例的结果稍差,并且有半数实例的结果优于对比算法50%。由此可见,ICSQPSO算法对双层规划的寻优能力明显优于对比算法。     

基于Pareto支配的双目标优化求解非线性双层规划问题

双层规划问题是一类具有双层递阶结构的系统优化问题。采用Pareto支配的双目标优化策略求解非线性双层规划问题。利用K-T条件把双层规划问题等价转化单层规划问题,进而结合约束部分建立可行性度量目标形成双目标规划问题。在基本的差分进化算法框架中融入非负的最小二乘曲线拟合判断候选解的可行性,构造基于动态概率的Pareto支配选择策略挑选下一代个体,解决种群容易陷入局部最优的缺陷。15个标准函数的测试结果对比显示,该算法在求解非线性双层规划问题中具有较好的全局寻优能力、较低的计算复杂度、较强的稳定性和适用性,可以获得全局最优解。     

求解双层规划优化问题的层次风驱动优化算法

针对双层规划的求解问题, 提出一种层次风驱动优化算法. 初始化上层优化变量后, 首先对下层规划进行求解, 满足约束条件的同时, 更新下层规划中的空气质点速度和位置; 然后, 利用风驱动优化算法对上层规划问题进行求解; 最后, 在优化解集合中, 选择上下层规划目标值次序之和最小的解作为最终优化解. 实验结果表明, 所提出的层次风驱动算法是一种有效的求解双层规划问题的方法.

     

考虑区间约束的物流网络双层规划模型及算法

考虑物流网络需求的不确定性,利用区间参数度量不确定性变量与参数,建立区间需求模式下的物流网络双层规划模型,设计了一种含区间参数与变量的递阶优化遗传算法,通过定义问题求解的风险系数与最大决策偏差,给出适合物流网络结构的区间运算准则,实现模型的确定性转化。以区间松弛变量与0-1决策变量定义初始种群,通过两阶遗传操作运算,求解不同情景下双层规划目标的区间最优解与节点决策方案。算例测试表明算法求解的可操作性更强,求解结果具有区间最优解与情景决策的优越性。     

一个基于插值的解非线性双层规划的遗传算法

非线性双层规划问题是一类递阶优化问题,相关的算法往往需要对每一个上层变量值求一个下层优化问题才能得到一个可行点,这使得算法的计算量很大.目前文献中的算法通常都是基于对每个确定的上层变量,下层最优解唯一的条件,这就意味着每个下层变量的分量都可以看成是上层变量的函数.基于这个思想,同时为了避免频繁计算下层优化问题,文中提出了一种新的方法.这种方法与已有方法的主要不同之处在于,它不需频繁求解下层规划,而是用插值函数近似下层最优解函数.其主要思想如下:首先,取一些上层变量值作为插值节点,计算它们对应的下层问题的最优解,这些最优解的第i个分量作为第i个插值函数的函数值,利用这些节点和函数值计算插值函数;其次,将插值函数代入上层问题,得到一个近似原问题的单层规划;最后用一个新的遗传算法求解该单层规划.由于插值节点和相应的插值函数在进化过程中自适应修正和更新,这样可使得该单层规划问题的最优解逐步逼近原问题的最优解,并且可减少计算量.对25个测试问题的仿真结果表明,该文所提出的算法能以较少的计算量找到这些问题的最好解.     

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     

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.     

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.     

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.