区间序信息系统及其属性约简算法

在不含决策属性的区间序信息系统中,区间偏序关系的不完备性造成信息流失。针对该问题,提出一种新的基于区间模糊数的区间序全序关系,以此建立区间序信息系统,并分析其相关上、下近似的单调性和包含性。采用不可区分函数的方法,给出区间序信息系统的属性约简算法,并通过算例验证了该算法的有效性。     

具有约束多目标优化的进化算法

针对带有约束多目标优化问题,提出一种多目标优化进化算法。在选择过程中,采用约束的Pareto支配和聚集距离定义适应值,根据适应值挑选出有代表性的个体。在变异过程中,沿着权重梯度方向搜索来寻找可行的Pareto最优解。最后,采用两个数值算例测草算法的性能,结果表明该算法能获得多目标约束优化问题的可行Pareto最优解并且具有较好的分散性。     

基于IEEE 802.11无线局域网的VoIP性能分析

对无线局域网的两种标准IEEE 802.11b和IEEE 802.11g的差异进行了研究,后者在前者的基础上采用了正交频分复用(OFDM)技术,通过设计一个针对这两种标准的无线局域网上的VoIP性能测试的试验,使用Chariot网络工具进行仿真,对延迟、抖动、丢包率进行对比分析,结果表明IEEE 802.11g标准比IEEE 802.11b标准具有明显的性能优势.     

一种最大向量平均个数的估计方法

提出一种估计n个d维向量中最大向量平均个数的方法。该方法通过分析单个向量与其他向量子集的支配关系,求出最大向量平均个数的解析式。证明解析式满足已知的递归关系,得到最大向量平均个数的近似估计。与已有方法相比,该方法可应用到估计k个其他向量支配的平均个数问题。     

Multi-objective optimization with artificial weed colonies

Invasive Weed Optimization (IWO) was recently proposed as a simple but powerful metaheuristic algorithm for real parameter optimization. IWO draws inspiration from the ecological process of weeds colonization and distribution and is capable of solving general multi-dimensional, linear and nonlinear optimization problems with appreciable efficiency. This article extends the basic IWO for tackling multi-objective optimization problems that aim at achieving two or more objectives (very often conflicting) simultaneously. The concept of fuzzy dominance has been used to sort the promising candidate solutions at each iteration. The new algorithm has been shown to be statistically significantly better than some state of the art existing evolutionary multi-objective algorithms, namely NSGAIILS, DECMOSA-SQP, MOEP, Clustering MOEA, GDE3, and MOEADGM on a 12-function test-suite (including both unconstrained and constrained problems) from the IEEE CEC (Congress on Evolutionary Computation) 2009 competition and special session on multi-objective optimization algorithms. The following performance metrics were considered: IGD, Spacing, and Minimum Spacing. Our experimental results suggest that IWO holds immense promise to appear as an efficient metaheuristic for multi-objective optimization.     

Automatic Registration of Multi‐Projector Domes Using a Single Uncalibrated Camera

In this paper we present a novel technique for easily calibrating multiple casually aligned projectors on spherical domes using a single uncalibrated camera. Using the prior knowledge of the display surface being a dome, we can estimate the camera intrinsic and extrinsic parameters and the projector to display surface correspondences automatically using a set of images. These images include the image of the dome itself and a projected pattern from each projector. Using these correspondences we can register images from the multiple projectors on the dome. Further, we can register displays which are not entirely visible in a single camera view using multiple pan and tilted views of an uncalibrated camera making our method suitable for displays of different size and resolution. We can register images from any arbitrary viewpoint making it appropriate for a single head‐tracked user in a 3D visualization system. Also, we can use several cartographic mapping techniques to register images in a manner that is appropriate for multi‐user visualization. Domes are known to produce a tremendous sense of immersion and presence in visualization systems. Yet, till date, there exists no easy way to register multiple projectors on a dome to create a high‐resolution realistic visualizations. To the best of our knowledge, this is the first method that can achieve accurate geometric registration of multiple projectors on a dome simply and automatically using a single uncalibrated camera.     

Chemical correlates of α-tocopherol (Vitamin E) alteredMalacosoma disstria herbivory inFraxinus pennsylvanica var.Subintegerrinia,green ash

The antioxidant -tocopherol (vitamin E), applied in a basal trunk band to the green ash tree,Fraxinus pennsylvanica var.subintergerrinia, elicited an alteration of foliar feeding byMalacosoma disstria larvae (Lepidoptera: Lasiocampidae). The bioassayed effects were dependent on the dosage of elicitor, the time after elicitation, and the position in the tree. Leaves for chemical analysis were collected from trees receiving two dosages and at two intervals after elicitation. Compounds in the ethyl acetate extractables from the ash tree leaves were separated by TLC and HPLC. TLC separations showed differences in the nonhydrolyzed extractables attributable to elicitor dosage and time after elicitation. TLC-resolved differences were also evident among acid-hydrolyzed samples. HPLC-resolved profiles revealed eight peaks in the nonhydrolyzed extractables that were quantitatively negatively correlated with larval feeding preference between elicited versus control foliage on at least one of the two sampling dates. Results from this study and other investigations reported in the literature indicate that the antioxidant-tocopherol (vitamin E) can function as an environmental-stress elicitor of alterable defensive chemistry in green ash and other plants.     

均衡论框架下日语「对称」现象的再考察

以徐德明和陈伟明[1]的「均衡论框架下日语中"对称"现象之考察」所列的对称式均衡模型为基础,再度讨论了日语语言结构的对称现象。明确了日语语言结构学方面迄今为止的分析法,以及徐.陈分析法各自的归属。以对称式均衡模型以及图像对日语句子的无形、抽象和隐性结构进行了分析,使其有形化、形象化以及显性化。     

基于包含度的不完备序信息系统属性约简的一种算法

在不完备序信息系统中,通过引入包含度的概念,对属性重要度进行了定义;在此基础上,提出了一种基于包含度的属性约简算法;最后,通过实例分析表明,该算法能得到不完备序信息系统的一个约简.