氡及其子体运移仿真系统开发

基于.net开发平台,借助C讨论了仿真系统的软件实现过程,简述了系统的功能模块及关键技术实现.实现了氡及其子体运移机制研究的计算机化.     

Boosting support vector machines for imbalanced data sets

Real world data mining applications must address the issue of learning from imbalanced data sets. The problem occurs when the number of instances in one class greatly outnumbers the number of instances in the other class. Such data sets often cause a default classifier to be built due to skewed vector spaces or lack of information. Common approaches for dealing with the class imbalance problem involve modifying the data distribution or modifying the classifier. In this work, we choose to use a combination of both approaches. We use support vector machines with soft margins as the base classifier to solve the skewed vector spaces problem. We then counter the excessive bias introduced by this approach with a boosting algorithm. We found that this ensemble of SVMs makes an impressive improvement in prediction performance, not only for the majority class, but also for the minority class.     

Short text similarity based on probabilistic topics

In this paper, we propose a new method for measuring the similarity between two short text snippets by comparing each of them with the probabilistic topics. Specifically, our method starts by firstly finding the distinguishing terms between the two short text snippets and comparing them with a series of probabilistic topics, extracted by Gibbs sampling algorithm. The relationship between the distinguishing terms of the short text snippets can be discovered by examining their probabilities under each topic. The similarity between two short text snippets is calculated based on their common terms and the relationship of their distinguishing terms. Extensive experiments on paraphrasing and question categorization show that the proposed method can calculate the similarity of short text snippets more accurately than other methods including the pure TF-IDF measure.     

带有自适应补偿的不确定时滞系统鲁棒跟踪控制

为了克服高增益反馈项的缺陷, 设计了一个带有自适应补偿的控制器用于不确定时滞系统鲁棒跟踪控制. 本文证明了自适应补偿项的引入不会影响原来闭环系统的稳定性. 因此, 可以根据跟踪性能的需求和控制增益的约束来决定是否采用自适应补偿项. 最后, 数值仿真表明了控制器的有效性.     

基于FPGA的小数分频实现方法

提出了一种基于FPGA的小数分频实现方法。介绍了现有分频方法的局限性,提出一种新的基于两级计数器的分频实现方法,给出该方法的设计原理以及实现框图,利用软件对电路进行仿真,由仿真结果可以看出该方法可有效实现输入信号频率的小数调整,最后分析了方法的优缺点及其应用领域。实验结果表明,设计方法能够高精度地完成对信号频率的微调,并且频率转换时间被缩短到2.56μs。     

基于FPGA的新型高性能永磁同步电机驱动系统设计

提出了一种基于FPGA的单芯片驱动控制方案。它采用硬件模块化的现代EDA设计方法,使用VHDL硬件描述语言,实现了永磁同步电机矢量控制系统的设计。     

A blog emotion corpus for emotional expression analysis in Chinese

Weblogs are increasingly popular modes of communication and they are frequently used as mediums for emotional expression in the ever changing online world. This work uses blogs as object and data source for Chinese emotional expression analysis. First, a textual emotional expression space model is described, and based on this model, a relatively fine-grained annotation scheme is proposed for manual annotation of an emotion corpus. In document and paragraph levels, emotion category, emotion intensity, topic word and topic sentence are annotated. In sentence level, emotion category, emotion intensity, emotional keyword and phrase, degree word, negative word, conjunction, rhetoric, punctuation, objective or subjective, and emotion polarity are annotated. Then, using this corpus, we explore these linguistic expressions that indicate emotion in Chinese, and present a detailed data analysis on them, involving mixed emotions, independent emotion, emotion transfer, and analysis on words and rhetorics for emotional expression.     

Spoken emotion recognition through optimum-path forest classification using glottal features

A new method for the recognition of spoken emotions is presented based on features of the glottal airflow signal. Its effectiveness is tested on the new optimum path classifier (OPF) as well as on six other previously established classification methods that included the Gaussian mixture model (GMM), support vector machine (SVM), artificial neural networks – multi layer perceptron (ANN-MLP), k-nearest neighbor rule (k-NN), Bayesian classifier (BC) and the C4.5 decision tree. The speech database used in this work was collected in an anechoic environment with ten speakers (5 M and 5 F) each speaking ten sentences in four different emotions: Happy, Angry, Sad, and Neutral. The glottal waveform was extracted from fluent speech via inverse filtering. The investigated features included the glottal symmetry and MFCC vectors of various lengths both for the glottal and the corresponding speech signal. Experimental results indicate that best performance is obtained for the glottal-only features with SVM and OPF generally providing the highest recognition rates, while for GMM or the combination of glottal and speech features performance was relatively inferior. For this text dependent, multi speaker task the top performing classifiers achieved perfect recognition rates for the case of 6th order glottal MFCCs.     

Calibration of residual stress difference of MetalMUMPs silicon nitride films

The metal multi-user MEMS processes (MetalMUMPs) provide one nickel film, two silicon nitride films and one polysilicon film for constructing various nickel MEMS devices. The two silicon nitride films are either bonded together as a bi-layered structure or they sandwich the polysilicon film to form a tri-layered structure to support nickel structures. The residual stress difference of the two silicon nitride films causes undesired deformations of suspended MetalMUMPs devices. In this paper, the residual stress difference of the two MetalMUMPs silicon nitride thin films is calibrated and the result is 169 MPa. The Young’s modulus of the MetalMUMPs nitride films is also measured, which is 209 GPa.