一次风反切系统的数值模拟和多相流动特性分析

四角切圆燃烧锅炉,存在着稳燃和结渣的矛盾,一次风微反切技术已在多台锅炉上得到应用,较好地解决了这对矛盾并能在一定程度上降低ＮＯｘ的排放量。本文把湍流理论和多相流动理论应用于炉内空气动力场的计算机数值模拟,用投影法编制的计算软件对６００ＭＷ锅炉炉内流动进行了计算,得出了一次风反切系统中炉内速度场、实际切圆、颗粒运动轨迹等结果,与冷炉和冷模试验基本吻合,对一次风反切系统的设计和调试具有参考价值。     

Full-order observer-based actuator fault detection and reduced-order observer-based fault reconstruction for a class of uncertain nonlinear systems

This paper considers observer-based actuator fault detection and reconstruction problems for uncertain nonlinear systems. Based on a kind of full-order observer which is robust to disturbances but sensitive to actuator faults, a single detection observer is constructed to produce a residual which can be used to alarm the occurrence of the actuator faults when at least one actuator fault occurs indeed. The full-order observer is adaptive one because an adaptation law which can adjust the Lipschitz constant of Lipschitz term is introduced. For this reason, the Lipschitz constant can be unknown in our design. After this, a kind of reduced-order observer is developed by choosing a special observer gain matrix. Based on the reduced-order observer, we provide a kind of unknown information estimating method which can be used to not only reconstruct the actuator faults but also estimate the disturbances of the system. In simulation, a real model of the seventh-order aircraft is used to illustrate the effectiveness of the proposed methods.     

基于粒子系统和音频系统的烟花模拟

针对模糊物体的模拟方法存在着粒子数量绘制巨大、粒子运动状态复杂、计算耗时、实时性及逼真性不够等问题,提出了一种基于粒子系统和音频系统的烟花模拟方法,以三角形格作为绘制烟花粒子的基本图元,结合纹理映射,色彩融合技术来绘制烟花粒子,在显示列表中生成纹理,再结合FMOD引擎技术,加入音频系统,实验结果表明提出的方法增强了模拟的逼真性.     

决策树算法在饰品营销中的应用

阐述了饰品企业营销的现状,提出了将数据挖掘技术应用到饰品营销中的方案.在分析决策树算法的基础上,介绍了决策树算法及决策树的构造,并使用该算法对企业客户进行分类及对新客户类型预测,实现对商业数据中隐藏信息的挖掘,且对该挖掘模型进行了验证.     

物元模型可拓控制的控制算法实现

可拓控制是最近几年发展起来的一种智能控制技术。本文在主要基于可拓集合理论发展起来的控制器模型基础上进行了扩充完善,主要是引入物元来表示控制中的各种信息流,并结合物元变换拓展及物元可拓展运算一起来实现控制算法,而使系统可实现多变量控制,同时因引入文献［４］中的可拓专家系统来实现上层控制器而使控制器的智能大大提高,真正具有创造性的辩证思维能力。     

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.     

A study of the optimal measurement placement for parameter identification of orthotropic composites by the boundary element method

This paper concentrates on the design of the optimal measurement placement for the parameter identification of two-dimensional orthotropic composites, which is modeled by the boundary element. From the analysis of the well-posedness of the parameter identification processes using the Levenberg–Marquardt method, a performance indicator and an estimation of the maximum bias of identified parameters are deduced. Based on these results, a method for selecting the optimal measurement placement is proposed. The validity of this method is illustrated by some numerical examples. These examples reveal that the measurement placement has significant influence on identification results. Furthermore, an iterative process of selecting measurement placement is suggested for practical implementation.     

基于犯罪画像的计算机取证分析方法研究

犯罪嫌疑人的画像分析已经引起了广泛的关注,在各种媒体领域都得到了广泛的应用,计算机领域也已经开始了这方面的研究内容。犯罪嫌疑人画像的分析主要是对犯罪现场分析和犯罪行为调查的心理分析。通过对传统物理取证分析方法和现有的计算机取证分析方法的总结,将传统犯罪取证研究中的犯罪轮廓构建技术应用于计算机犯罪取证研究中,缩小取证调查范围,协助工作人员办案,从而锁定罪犯,提高案件的侦破效率。提出用数据挖掘的方法进行取证。     

PNX0101及其在便携式MP3播放器中的应用

目前,便携式MP3播放器的发展十分迅速。用户对便携式MP3播放器的音质、体积、功耗等方面提出了越来越高的要求。Philips公司推出的32位ARM+DSP双核结构的PNX0101芯片因其一流的音质表现、更小的尺寸、更小的功耗等特点成为解码芯片领域的热点。本文介绍了PNX0101的结构和特点,分析了它具有竞争力的优异性能,并对基于PNX0101设计的便携式MP3播放器及其电源管理进行了讨论。