千兆位交换式路由器的背板设计

可同时传输多个包的交换式背板替代拥塞、共享型背板是高性能路由器发展的必然趋势。文章介绍了路由器结构的演变,对交换式背板的需求进行了分析,并研究了设计交换式背板所必须解决的一些问题,最后,给出了一个吞吐率为６４Ｇｂｐｓ的交换式背板的具体设计。     

一种自由曲面的快速跟踪求交算法

自由白面的求交算法在ＣＡＤ／ＣＡＭ软件系统中占有重要的地位,并对软件运行的效率有较大的影响。目前常用的Ｂｅｚｉｅｒ曲面分割法难以满足高精度和高速度的要求。为此该文提出了利用交线的几何信息进行快速求交的算法,同时兼顾了快速和高精度两方面的要求,并已在作者自行开发的软件中得到了成功的应用。     

综合信息的多神经网系统应用于引擎故障诊断

在数据层和决策层综合信息,采用多人工神经网络系统诊断故障.通过对全互连、前馈、BP人工神经网的学习训练,可识别不同类型的故障;将诊断任务分解为多个子任务,对每个子任务训练相应的神经网,最后将多个神经网的结果综合起来,以提高系统性能.     

Structural-symmetry-related sequence patterns of the proteins of beta-propeller family

It is still not very clear to what extent and how does the amino acid sequences of proteins determine their tertiary structures. In this paper, we report our investigations of the sequence-structure relations of the proteins in the beta-propeller fold family, which adopt highly symmetrical tertiary structures while their sequences appear "random". We analyzed the amino acid sequences by using a similarity matrix plus Pearson correlation method and found that the sequences can show the same symmetries as their tertiary structures only if we deduce the conditions of sequence similarity. This suggests that some key residues may play an important role in the formation of the tertiary structures of these proteins.     

一种基于多代理技术实现的虚拟企业中的敏捷调度

提出了一种用多代理技术和基于协商的策略解决虚拟企业调度冲突的方法。首先介绍了虚拟企业中敏捷调度的特性及调度冲突的产生,分类及解决方法,并描述了调度、计划、协商、监督执行之间的互操作,通过代理的智能,自治等特性可以较好地实现调度的敏捷性,最后给出了在一个面向虚拟企业的信息集成系统ViaSopc中基于多代理技术实现的基于协商的敏捷调度模型。     

活塞加工的计算机辅助工艺过程设计

本文介绍一个在微机上实现的活塞CAPP系统,它具有适合于活塞结构与工艺特点的分段层次式混合编码输入系统和嵌入式知识基形式的工艺决策系统,可自动生成包括工艺规程、工序卡、相应刀、夹、量、辅具的全套完整工艺文件。在工序图自动绘制方面,本文还提出了一种“半参数化”自动生成技术。     

中条山胡—蓖型铜矿床成因新认识

讨论了剥离断层与成矿物质来源,矿体空间分布型式以及矿化特征等方面联系,从而提出胡-蓖型铜矿床是一个受剥离断层控制的“热液型(断)层状矿床”。     

An automated vision based on-line novel percept detection method for a mobile robot

It is generally agreed that learning, either supervised or unsupervised, can provide the best possible specification of known classes and offer inference for outlier detection by a dissimilarity threshold from the nominal feature space. Novel percept detection can take a step further by investigating whether these outliers form new dense clusters in both the feature space and the image space. By defining a novel percept to be a pattern group that has not been seen before in the feature space and the image space, in this paper, a non-conventional approach is proposed for multiple-novel-percept detection problem in robotic applications. Based on a computer vision system inspired loosely by neurobiological evidence, our approach can work in near real time for highly sparse high-dimensional feature vectors extracted from image patches while maintaining robustness to image transformations. Experiments conducted in an indoor environment and an outdoor environment demonstrate the efficacy of our method.     

Modeling NOx emissions from coal-fired utility boilers using support vector regression with ant colony optimization

Modeling NO_x emissions from coal fired utility boiler is critical to develop a predictive emissions monitoring system (PEMS) and to implement combustion optimization software package for low NO_x combustion. This paper presents an efficient NO_x emissions model based on support vector regression (SVR), and compares its performance with traditional modeling techniques, i.e., back propagation (BPNN) and generalized regression (GRNN) neural networks. A large number of NO_x emissions data from an actual power plant, was employed to train and validate the SVR model as well as two neural networks models. Moreover, an ant colony optimization (ACO) based technique was proposed to select the generalization parameter C and Gaussian kernel parameter γ. The focus is on the predictive accuracy and time response characteristics of the SVR model. Results show that ACO optimization algorithm can automatically obtain the optimal parameters, C and γ, of the SVR model with very high predictive accuracy. The predicted NO_x emissions from the SVR model, by comparing with the BPNN model, were in good agreement with those measured, and were comparable to those estimated from the GRNN model. Time response of establishing the optimum SVR model was in scale of minutes, which is suitable for on-line and real-time modeling NO_x emissions from coal-fired utility boilers.