高温快烧釉中彩颜料的研究

为解决日用瓷铅镉溶出问题和提高装饰档次，研制成功１８种高温快烧颜料色基及专用熔剂。经测试，１８种颜料的各项指标全部达到国家标准要求，铅镉溶出量全部为０．０ｍｇ／ｄｍ２．     

A transient method for characterizing flow regimes in a circulating fluid bed

In recent years, although an increasing number of literature have been devoted to circulating fluidized bed (CFB), the prediction of velocities over which different fluidization regimes exist is still difficult. In this study, a transient method was applied which readily allows one to identify operational features and critical transitions. The method is based on stopping the solids flow rate into the riser when riser is operating in fully dense transport regime. The analysis of transient pressure drop data across the riser during a solids flow cut-off experiment against its time derivative demonstrate the three distinct operating regimes that exist as the gas deplete the solid out of the riser. The transient was compared to data taken under steady state operations using statistically designed experiments. Results indicated that although there were significant differences when comparing operations in dilute conditions, there were no significant differences between the two methods in the fast fluidized and dense transport regimes. The transient method was capable of reproducing the solids circulation dependence on riser solids holdup and on the axial pressure profile. This transient method offers an accurate, easy, rapid, and reproducible means of characterizing CFB operations over a wide range of flow conditions. The lack of accuracy in the dilute regime is conjectured to be due to the wide particle size distribution that resulted in segregation during the transient testing.     

Ball-Tree优化的密度峰值聚类算法

针对密度峰值聚类算法DPC（clustering by fast search and find of density peaks）时间复杂度高、准确度低的缺陷,提出了一种基于Ball-Tree优化的快速密度峰值聚类算法BT-DPC。算法利用第[k]近邻度量样本局部密度,通过构建Ball-Tree加速密度[ρ]及距离[δ]的计算;在类簇分配阶段,结合[k]近邻思想设计统计学习分配策略,将边界点正确归类。通过在UCI数据集上的实验,将该算法与原密度峰值聚类算法及其改进算法进行了对比,实验结果表明,BT-DPC算法在降低时间复杂度的同时提高了聚类的准确度。     

Two-level searching tracking algorithm based on fast Fourier transform

In order to solve the problems of appearance change, scale and rotation change in the visual tracking, a two-level searching tracking algorithm based on Fast Fourier Transform(FFT)is proposed. It achieves two-level searching by establishing the object's kernel ridge regression model in the Cartesian coordinates and log-polar coordinates, respectively, and the efficiency can be improved by transforming the operation into the frequency domain based on FFT. First, the kernel ridge regression model is constructed in the Cartesian coordinate and the object's center position is obtained by the exhaustive search method based on the circular structure matrix. Then, it transforms the object area to the log-polar coordinates and searches the shift using the kernel ridge regression model in the log-polar coordinates. Finally, the object's state is calculated according to the searching results and the object's model is updated. Experimental results indicate that the proposed algorithm not only can obtain a distinct improvement in coping with the appearance change, scale and rotation change, but also have a high tracking efficiency.     

大场景 SAR图像舰船目标快速检测

基于SAR图像的舰船目标检测是海洋监视应用的重要方面,随着SAR图像资源的不断丰富,计算速度成为衡量舰船目标检测算法的重要指标。针对大场景SAR图像,提出一种基于分块CFAR的舰船目标快速检测算法。首先通过图像增强提高舰船目标与海洋杂波之间的对比度,然后利用差异性参数进行分块筛选,剔除不包含目标的区域,最后对待检测区域实现基于积分图的快速CFAR检测。TerraSAR_X实测数据的实验结果验证了该方法的有效性。     

一种高效的全局K-均值算法

针对全局K-均值算法时间复杂度大的问题,提出一种增量选择初始聚类中心的新方法。选择数据集中周围分布最密集的样本作为第一个初始聚类中心,选择最小化目标函数贡献大,并且和已有聚类中心距离远的样本作为下一个初始聚类中心。改进算法减少了增量选取初始聚类中心时的计算量,降低了时间复杂度。实验证明,改进算法与全局K-均值算法、快速全局K-均值算法相比,在不影响聚类效果的基础上,减少了聚类时间,与优化初始聚类中心的算法相比,聚类效果更优。     

数控机床永磁同步直线伺服系统免疫控制

针对数控机床永磁同步直线电机(PMLSM)伺服进给系统存在的波纹推力扰动、齿槽力扰动、端部效应扰动和其他不确定性扰动的问题,应用免疫反馈系统的免疫性原理在传统PID基础上设计了一种免疫PID控制器.免疫系统在大干扰和不确定性环境中都具有很强的鲁棒性和自适应性,使伺服系统既具有快速响应和设计简单的特点,又结合了免疫控制的抗干扰特性.在M ATLAB环境下对永磁同步直线电机数控机床伺服进给系统进行仿真,结果表明,此种控制方案下的PMLSM伺服系统具有更好的控制精度、较快的响应速度和较小的超调量,抗干扰能力更强.     

一种基于图像边缘的快速模板匹配方法

提出了一种基于边缘的快速模板匹配方法,算法首先把模板二值化,根据传统标记目标区域的方法对二值化后的模板图进行标记,利用八临域判别准则提取各个区域的边界,在匹配时只匹配区域边界上的点,同时设定阈值,若前面n个点与模板图的前n个点的绝对差和超过阈值,则跳过该搜索区域。实验结果表明,不仅减少了匹配计算量,而且能够保证匹配的精确性。     

矩形环可重构天线的建模和仿真研究

可重构天线采用同一个天线或天线阵,通过引入开关器件控制天线的辐射结构来实现工作模式的转换,使其具有多个天线的功能.文中阐述了矩形环可重构天线工作的基本机理,为实现满足不同环境对天线性能的要求,利用Matlab对矩形环可重构天线进行建模,将遗传算法与矩量法相结合,对天线的性能进行搜索寻优.为进一步提高天线分析速度,从广义角度把天线的开关当作加载元件处理,利用Sherman-Morrison-Woodbury公式减少阻抗矩阵的计算量,提高天线特性参数的计算速度,改善了现有商业软件对天线仿真分析耗时大的问题,显著提高了效率.     

振动流化床床层压降理论分析与实验研究

从振动流化床床层压降的物理意义出发,得出了振动流化床床层压降模型。提出振动流化床床层压降-流速曲线上存在第一、第二流化段,相应速度为第一、第二临界流化速度。并在二维振动流化床内,以不同粒径的玻璃珠为床料进行了实验研究,分析了振动及其它操作条件对床层压降的影响,并将模型计算得到的压降与实验结果进行了比较,结果表明模型预测与实验结果有较好的一致性。实验关联了振动能量传递系数的数学表达式,得到第一、第二临界流化速度时床层压降,并与其他研究者的结果进行了对比分析,结果显示本文的模型能得到更为可靠的预测结果。