基于文本分类的输变电设备缺陷分析

为提高电力设备缺陷文本利用效率,构建缺陷文本分类模型。首先分析了中文文本分类的流程,然后结合电力设备缺陷文本的特点,构建了4层卷积神经网络的电力缺陷文本分类模型;最后以某市近10年来的电力设备缺陷文本记录作为数据来源,结合上述的模型,对数据进行训练和分类,并与部分传统的机器学习分类模型进行比较。结果表明,提出的分类模型的错误率为2.86%,远低于传统的6.99%,具有明显的优势。     

A parallel and robust object tracking approach synthesizing adaptive Bayesian learning and improved incremental subspace learning

This paper presents a novel tracking algorithm which integrates two complementary trackers. Firstly, an improved Bayesian tracker(B-tracker) with adaptive learning rate is presented. The classification score of B-tracker reflects tracking reliability, and a low score usually results from large appearance change. Therefore, if the score is low, we decrease the learning rate to update the classifier fast so that B-tracker can adapt to the variation and vice versa. In this way, B-tracker is more suitable than its traditional version to solve appearance change problem. Secondly, we present an improved incremental subspace learning method tracker(Stracker). We propose to calculate projected coordinates using maximum posterior probability, which results in a more accurate reconstruction error than traditional subspace learning tracker. Instead of updating at every time, we present a stopstrategy to deal with occlusion problem. Finally, we present an integrated framework(BAST), in which the pair of trackers run in parallel and return two candidate target states separately. For each candidate state, we define a tracking reliability metrics to measure whether the candidate state is reliable or not, and the reliable candidate state will be chosen as the target state at the end of each frame. Experimental results on challenging sequences show that the proposed approach is very robust and effective in comparison to the state-of-the-art trackers.     

Stance detection via sentiment information and neural network model

Stance detection aims to automatically determine whether the author is in favor of or against a given target. In principle, the sentiment information of a post highly influences the stance. In this study, we aim to leverage the sentiment information of a post to improve the performance of stance detection. However, conventional discretemodels with sentimental features can cause error propagation. We thus propose a joint neural network model to predict the stance and sentiment of a post simultaneously, because the neural network model can learn both representation and interaction between the stance and sentiment collectively. Specifically, we first learn a deep shared representation between stance and sentiment information, and then use a neural stacking model to leverage sentimental information for the stance detection task. Empirical studies demonstrate the effectiveness of our proposed joint neural model.     

Deep Learning Based Prediction of Gas Chromatographic Retention Indices for a Wide Variety of Polar and Mid-Polar Liquid Stationary Phases

Prediction of gas chromatographic retention indices based on compound structure is an important task for analytical chemistry. The predicted retention indices can be used as a reference in a mass spectrometry library search despite the fact that their accuracy is worse in comparison with the experimental reference ones. In the last few years, deep learning was applied for this task. The use of deep learning drastically improved the accuracy of retention index prediction for non-polar stationary phases. In this work, we demonstrate for the first time the use of deep learning for retention index prediction on polar (e.g., polyethylene glycol, DB-WAX) and mid-polar (e.g., DB-624, DB-210, DB-1701, OV-17) stationary phases. The achieved accuracy lies in the range of 16–50 in terms of the mean absolute error for several stationary phases and test data sets. We also demonstrate that our approach can be directly applied to the prediction of the second dimension retention times (GC × GC) if a large enough data set is available. The achieved accuracy is considerably better compared with the previous results obtained using linear quantitative structure-retention relationships and ACD ChromGenius software. The source code and pre-trained models are available online.     

阵风环境模拟用控制器设计与实验研究

针对环境模拟实验室风环境模拟的阵风特性,设计开发了一种迭代学习自校正PID控制器。该控制器将设定值序列进行迭代学习优化,系统内部采用PID自校正控制策略。仿真和实验结果表明,两种控制方式的结合,可改善系统设定点改变时的动态特性,实现了对期望风环境参数的有效控制。迭代学习控制的作用下,特别是对正弦风的模拟,随着时间推移实际值可跟踪定值,保证了环境模拟的控制精度。     

基于极端学习机的MANET移动性预测模型

针对移动自组织网络移动性在管理无线网络带宽资源可用性方面的重要性,为了更好地规划连续服务可用性和有效能源管理以提升网络的整体服务质量,提出了一种基于极端学习机的MANET移动性预测模型。利用ELM对MANET中的任意节点进行建模;假设已知每个移动节点当前的移动性信息（位置、速度和运动方向角度）,以这种方式预测节点未来的位置和相邻节点之间未来的距离;基于几个标准移动性模型,产生更加真实、精确的移动性预测,从而更好地捕捉任意节点直角坐标系之间现有交互/相关性。使用标准移动性模型的仿真结果验证了所提模型的有效性,实验结果表明,提出的预测模型明显改进了传统基于多层感知器的模型,此外,当预测相邻节点之间未来距离时,避免了当前算法对预测精度的限制。     

基于改进蚁群算法的协作学习分组研究

协作学习中根据学习者的特征进行有效分组对于提高学习者的学习效率具有重要的作用。基于学习者的学习能力、兴趣爱好和理解水平,在基于蚁群算法的协作学习分组中,以学习者特征相似度值作为启发信息,并针对蚁群算法可能出现的早熟收敛和停滞现象,分别在初期加入判断回退机制和在中后期对启发因子及期望因子进行动态调节以保证分组结果的准确性。模拟实验结果表明该算法在分组性能及准确性上均优于传统算法。     

基于流形学习的JPEG图像定量隐写分析算法

提出了一种基于DCT系数统计特性的JPEG图像定量隐写分析算法。该算法在对JPEG图像DCT系数的统计模型进行研究的基础上,提取了能够反映嵌入容量变化规律的特征参数[α]。以特征参数[α]为基础,提出了基于流形学习的特征提取算法,通过LIB-SVM分类器进行训练,估计隐写对DCT系数的更改比率。实验结果表明,与传统的定量分析算法相比,提出的算法具有更高的估计准确率和稳定性。     

基于动态权值的多策略领域本体概念自动抽取

为了提高中文领域本体概念抽取的自动化程度及准确率,提出了一种基于动态权值的多策略中文领域本体概念自动抽取方法。针对中文领域本体概念的特点,采用自动学习的规则学习模式,筛选出候选概念,将改进的DR&DC、TF-IDF和NC-Value三种策略融合,对候选概念进行领域归属度排序,将最终权重超过阈值的概念存入最终概念集合。实验证明了该方法抽取领域概念的可行性和有效性。     

一种新的过采样算法DB_SMOTE

针对非平衡数据集中类分布信息不对称现象,提出一种新的过采样算法DB_SMOTE（Distance-based Synthetic Minority Over-sampling Technique）,通过合成少数类新样本解决样本不足问题。算法基于样本与类中心距离,结合类聚集程度提取种子样本。根据SMOTE（Synthetic Minority Over-sampling Technique）算法思想,在种子样本上实现少数类新样本合成。根据种子样本与少数类中心距离构造新样本分布函数。基于此采样算法并在多个数据集上进行分类实验,结果表明DB_SMOTE算法是可行的。