求解函数优化问题的改进人工蜂群算法

标准人工蜂群算法由于局部搜索能力差,收敛精度低,容易陷入早熟收敛等缺陷,从而求解最小值函数优化问题的能力受到限制。为了解决标准人工蜂群算法的以上问题,提出了一种改进的人工蜂群算法。该算法将混沌算子引入雇佣蜂和跟随蜂基于当前最优解的局部搜索策略中,并赋予跟随蜂细菌的趋药性,从而
　　提高了人工蜂群算法的局部搜索能力。在6个测试函数上的仿真结果表明,该算法能有效地避免陷入局部最优,并使收敛精度得到显著提高。     

基于当前最优解的分段搜索策略的人工蜂群算法

为了克服人工蜂群算法在求解函数优化问题中所存在的局部搜索能力差、收敛精度低的缺点,提出了一种基于当前最优解的分段搜索策略的人工蜂群算法。该算法中跟随蜂利用由全局当前最优解和个体当前最优解引导的局部搜索策略逐维进行变异,并采用基于“分段思想”的局部搜索策略对蜜源进行贪婪更新,以提高蜜源的更新效率,从而提高了人工蜂群算法的局部搜索能力。6个标准测试函数的仿真实验结果表明,与基本人工蜂群算法相比,改进后的人工蜂群算法在寻优精度和收敛速度上均有明显提高。     

基于当前最优解的人工蜂群算法

为克服人工蜂群算法在求解函数优化问题时存在收敛精度低、收敛速度慢的缺点,提出一种改进的人工蜂群算法。为提高人工蜂群算法的局部搜索能力和避免早熟收敛,跟随蜂在当前最优解的周围进行局部搜索,并随着迭代次数的增加,逐渐缩小侦查蜂在当前最优解周围的局部搜索范围。通过6个标准测试函数完成仿真实验,结果表明,与基本人工蜂群算法相比,改进算法在寻优精度和收敛速度上均得到提高。     

基于细菌趋药性和当前最优解策略的人工蜂群算法

为了克服人工蜂群算法在求解函数优化问题中所存在的收敛精度低、收敛速度慢的缺点,提出一种基于细菌趋药性和当前最优解策略的人工蜂群算法。该算法将细菌觅食优化算法中的趋向性操作引入到雇佣蜂的局部搜索策略中,然后跟随蜂在当前最优解的基础上继续进行寻优,从而提高了人工蜂群算法的局部搜索能力。8个标准测试函数的仿真实验结果表明,与基本人工蜂群算法相比,改进后的人工蜂群算法在寻优精度和收敛速度上均有明显提高。     

基于改进混合蜂群算法的非线性电路谐波平衡分析

针对射频电路非线性分析中谐波平衡方程求解问题,提出一种基于高斯扰动、锦标赛选择策略以及拟牛顿局部寻优算子的改进混合蜂群算法,该算法在搜索方程中引入基于当前全局最优解的高斯扰动,能有效防止算法陷入局部最优并加快算法收敛;跟随蜂采用锦标赛选择策略在一定程度上避免了算法的早熟现象;采用拟牛顿算子进行局部寻优,可使算法快速收敛。实验结果表明,改进混合蜂群算法成功应用于谐波平衡方程求解,与其他求解算法对比,收敛时间较短,性能较优。     

基于分段搜索策略的自适应差分进化人工蜂群算法

针对人工蜂群算法在求解函数优化问题时存在的探索能力强,而开发能力不足和收敛性能差的问题,本文提出一种基于分段搜索策略的自适应差分进化人工蜂群算法。该算法将改进后的差分进化算法中的变异操作引入到观察蜂的局部搜索策略中,让观察蜂在雇佣蜂逐维变异后的当前最优解周围进行局部搜索,并采用分段搜索的方式更新蜜源,以提高其局部搜索能力。仿真实验结果表明,与基本人工蜂群算法相比,改进后的算法有效地平衡了算法的探索能力和开发能力,并提高了算法的寻优精度和收敛速度。     

基于向量整体扰动的快速收敛人工蜂群算法

针对标准人工蜂群算法收敛速度慢和易陷入早熟收敛等问题,提出一种快速收敛人工蜂群算法。首先借助反向学习理论初始化种群来提高初始解的分布质量,并在雇佣蜂和跟随蜂阶段引入向量整体扰动搜索方程加快局部搜索;然后为了跳出局部最优,采用一种随机更新搜索策略来增加蜂群多样性以平衡全局探索和局部利用能力;最后通过八个标准测试函数的仿真实验,发现所提出的算法与几个改进的人工蜂群算法相比,具有更快的收敛速度且获得了更高的求解精度,验证了算法的优越性。     

混沌搜索策略的改进人工蜂群算法

针对人工蜂群算法的蜂群缺乏多样性、全局和局部搜索能力差及收敛速度较慢,提出一种基于混沌搜索策略的改进人工蜂群算法。该算法通过载波映射,由混沌-决策变量的变换,产生新的邻域点,为采蜜蜂和被招募的观察蜂提供了更广阔的搜索空间和更优质的位置蜜源,增强蜂群多样性;同时,引进侦查蜂局部蜜源搜索较好地解决了算法易陷入局部极小的问题,改善了人工蜂群算法的收敛性能。最后由6个标准测试函数的仿真验证,得到基于混沌搜索策略的人工蜂群算法性能明显优于标准人工蜂群算法。     

分阶段搜索的改进人工蜂群算法

针对人工蜂群(ABC)及其改进算法在求解高维复杂函数优化问题时,存在求解精度低、收敛速度慢、易陷入局部寻优且改进算法控制参数多的不足,提出一种分阶段搜索的改进人工蜂群算法。该算法设计了分阶段雇佣蜂搜索策略,使雇佣蜂在不同阶段具备不同的搜索特点,降低了算法陷入局部极值的概率;定义逃逸半径,使其能够更好地指导早熟个体跳出局部极值,避免了逃逸行为的盲目性;同时,采用均匀分布结合反向学习的初始化策略,促使初始解分布均匀且质量较优。通过对优化问题中8个典型高维复杂函数的仿真实验结果表明,该改进算法求解精度更高,收敛速度更快,更加适合高维复杂函数求解。     

基于改进邻域搜索策略的人工蜂群算法

针对人工蜂群算法存在易陷入局部最优、收敛速度慢的缺陷,提出一种改进邻域搜索策略的人工蜂群算法.首先,将混沌思想和反向学习方法引入初始种群,设计混沌反向解初始化策略,以增大种群多样性,增强跳出局部最优的能力;然后,在跟随蜂阶段根据更新前个体最优位置引入量子行为模拟人工蜂群获取最优解,通过交叉率设计更新前个体最优位置,并利用势阱模型的控制参数提高平衡探索与开发的能力,对观察蜂邻域搜索策略进行改进,以提高算法的收敛速度和精度;最后,将改进人工蜂群算法与粒子群算法、蚁群算法以及其他改进人工蜂群算法进行比较,利用12个标准测试函数进行仿真分析.结果表明,改进算法不仅提高了收敛速度和精度,而且在高维函数优化方面具有一定的优势.     

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。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.