L1-norm based null space discriminant analysis

Multimedia Tools and Applications - Null space based linear discriminant analysis (NSLDA) is a well-known feature extraction method, which can make use of the most discriminant information in the...     

Microstructural topology optimization of structural-acoustic coupled systems for minimizing sound pressure level

The aim of this paper is to present a microstructural topology optimization methodology for the structural-acoustic coupled system. In the structural-acoustic system, the structure is considered to be a thin composite plate composed of periodic uniform microstructures. The discrete design variables are used in the microstructural topology optimization, and the constitutive matrix is interpolated by the power-law scheme at the micro scale. The equivalent macro material properties of the microstructure are computed through the homogenization method. The design objective is to minimize the sound pressure level (SPL) in an interior acoustic medium. The sensitivities of the SPL with respect to design variables are derived. The bi-directional evolutionary structural optimization (BESO) method is extended to solve the structural-acoustic coupled optimization problem to find the optimal material distribution of the microstructure. Numerical examples of a hexahedral box and an automobile passenger compartment are given to demonstrate the efficiency of the presented microstructural topology optimization method.     

车载移动测量系统前方交会中的误差分析

车载移动测量系统是由多个传感器集成的系统,定位精度受到很多因素的影响.首先简要介绍了车载摄影测量中内外方位元素的计算方法;其次,针对线性法前方交会求解中符号矩阵的直接求逆内存占用大的问题,提出利用杜利特尔分解(LU分解)的方法,推导出了前方交会的解算公式;最后,针对短基线小交会角的情况利用误差传播定律分析了各误差源对最终定位结果的影响,对于进一步研究车载移动测量系统具有一定的参考意义.     

开放的大学英语网络教学运行环境和模式研究

通过对大学英语网络自主学习运行环境和教学模式的研究,介绍了现有网络学习运行环境包含的各种网络结构、软件架构、学习和考核方法等几个方面,讨论了各种环境因素在实际应用中的优劣与取舍原因,给出了开放教学理念下的网络运行环境研究结果。在研究中能给学生提供充分思考的空间、促进学生在学习中的独立思考和探索精神,进而达到学生素质全面发展的目的。     

Orientation space filtering for multiple orientation linesegmentation

The goal of this paper is to present an appropriate method for the segmentation of lines at intersections (X-junctions) and branches (T-junctions), which can be regarded as local regions where lines occur at multiple orientations. A novel representation called “orientation space” is proposed, which is derived by adding the orientation axis to the abscissa and the ordinate of the image. The orientation space representation is constructed by treating the orientation parameter, to which Gabor filters can be tuned, as a continuous variable. The problem of segmenting lines at multiple orientations is dealt with by thresholding 3D images in the orientation space and then detecting the connected components therein. In this way, X-junctions and T-junctions can be separated effectively. Curve grouping can also be accomplished. The segmentation of mathematically modeled X-, T-, and L-junctions is demonstrated and analyzed. The sensitivity limits of the method are also discussed. Experimental results using both synthesized and real images show the method to be effective for junction segmentation and curve grouping     

一种基于EM非监督训II练的自组织分词歧义解决方案

摘要本文旨在提供一种基于非监督训练的分词歧义解决方案和一种分词算法。基于EM的思想,每个句子所对应的所有(或一定范围内)的分词结果构成训练集,通过这个训练集和初始的语言模型可以估计出一个新的语言模型。最终的语言模型通过多次迭代而得到。通过一种基于该最终语言模型的统计分词算法,对于每个句子至少带有一个歧义的测试集的正确切分精度达到85.36％(以句子为单位)。     

配置和获取PCI设备资源

描述了PCI BIOS的功能软件接口,给软件开发者提供足够的信息来使用PCI设备资源而无需了解实际硬件知识,同时也为建立BIOS部分系统配置提供手段。     

数字电路虚拟实验系统中虚拟器件的探讨

虚拟实验系统中,虚拟器件的设计是整个系统设计的难点和关键所在。本文介绍应用Simulink设计虚拟器件的一些方法和技巧。     

我国GNP的单位根不确定性研究

对于一个实际的时间序列数据,我们并不知道其真正的数据生成过程,只能通过假设和基于假设的统计推断来确定。本文利用蒙特卡罗模拟进行有限样本的ADF检验。结果表明,当原假设是存在单位根,备择假设是趋势稳定时,ADF检验的势很低。这意味着,我国GNP存在单位根是不确定的。     

案例教学与适应性学习之初探

以适应性学习为基础,提出了在自适应性学习(Adaptive Learning)中如何将案例教学(Case-based Learning)融入其中,在学习中如何对学习进行评价,并根据评价为学习者提供与其相适应的案例,让学习者在情境中学习,使得学习更加高效可行。