多分类器融合在语音情感识别中的应用

针对语音情感识别问题,提出一种采用决策模板的多分类器融合方法,利用不同类型的声学特征子集来构造子分类器。不同的子集能充分提高各子分类器之间的“多样性”指标,这是多分类器融合算法能够成功应用的必备条件。与多数投票融合算法和支持向量机相比该方法取得了较好的识别结果。另一方面,从多样性指标分析的角度出发探究该方法能获得较好识别效果的原因。     

基于集成主成分分析的人脸识别

设计了一种基于主成分分析的分类器集成方法。应用随机子空间法获得多个初始分类器,由它们的分类性能给出分类器的保留分值,从而确定它们的保留优先级别,最后由保留优先级别选择一组分类器组成集成。理论分析和在人脸数据库ORL上的实验结果表明,这种基于集成PCA的分类方法能够更好地对模式进行分类。     

Eye pupil localization with an ensemble of randomized trees

We describe a method for eye pupil localization based on an ensemble of randomized regression trees and use several publicly available datasets for its quantitative and qualitative evaluation. The method compares well with reported state-of-the-art and runs in real-time on hardware with limited processing power, such as mobile devices.     

Keypoint recognition using randomized trees

In many 3D object-detection and pose-estimation problems, runtime performance is of critical importance. However, there usually is time to train the system, which we would show to be very useful. Assuming that several registered images of the target object are available, we developed a keypoint-based approach that is effective in this context by formulating wide-baseline matching of keypoints extracted from the input images to those found in the model images as a classification problem. This shifts much of the computational burden to a training phase, without sacrificing recognition performance. As a result, the resulting algorithm is robust, accurate, and fast-enough for frame-rate performance. This reduction in runtime computational complexity is our first contribution. Our second contribution is to show that, in this context, a simple and fast keypoint detector suffices to support detection and tracking even under large perspective and scale variations. While earlier methods require a detector that can be expected to produce very repeatable results, in general, which usually is very time-consuming, we simply find the most repeatable object keypoints for the specific target object during the training phase. We have incorporated these ideas into a real-time system that detects planar, nonplanar, and deformable objects. It then estimates the pose of the rigid ones and the deformations of the others.     

基于集成分类器的肿瘤亚型识别研究

针对肿瘤基因表达谱样本少,维数高的特点,提出一种用于肿瘤信息基因提取和亚型识别的集成分类器算法.该算法根据基因的Fisher比率值建立候选子集,再采用相关系数和互信息两种度量方法,分别构造反映基因共表达行为和调控关系的特征子集.粒子群优化算法分别与SVM和KNN构成两个基分类器,从候选子集中提取信息基因并对肿瘤亚型进行分类,最后利用绝对多数投票方法对基分类器的结果进行整合.G.Gordon肺癌亚型识别的实验结果表明了该算法的可行性和有效性.     

MRMR-based ensemble pruning for facial expression recognition

Multimedia Tools and Applications - Facial expression recognition (FER) can assist the interaction between humans and devices. The combination of FER and ensemble learning can usually improve final...     

Margin-based ensemble classifier for protein fold recognition

Recognition of protein folding patterns is an important step in protein structure and function predictions. Traditional sequence similarity-based approach fails to yield convincing predictions when proteins have low sequence identities, while the taxonometric approach is a reliable alternative. From a pattern recognition perspective, protein fold recognition involves a large number of classes with only a small number of training samples, and multiple heterogeneous feature groups derived from different propensities of amino acids. This raises the need for a classification method that is able to handle the data complexity with a high prediction accuracy for practical applications. To this end, a novel ensemble classifier, called MarFold, is proposed in this paper which combines three margin-based classifiers for protein fold recognition.The effectiveness of our method is demonstrated with the benchmark D-B dataset with 27 classes. The overall prediction accuracy obtained by MarFold is 71.7%, which surpasses the existing fold recognition methods by 3.1–15.7%. Moreover, one component classifier for MarFold, called ALH, has obtained a prediction accuracy of 65.5%, which is 4.7–9.5% higher than the prediction accuracies for the published methods using single classifiers. Additionally, the feature set of pairwise frequency information about the amino acids, which is adopted by MarFold, is found to be important for discriminating folding patterns. These results imply that the MarFold method and its operation engine ALH might become useful vehicles for protein fold recognition, as well as other bioinformatics tasks. The MarFold method and the datasets can be obtained from: (http://www-staff.it.uts.edu.au/～lbcao/publication/MarFold.7z).     

Landmark recognition with compact BoW histogram and ensemble ELM

Along with the rapid development of mobile terminal devices, landmark recognition applications based on mobile devices have been widely researched in recent years. Due to the fast response time requirement of mobile users, an accurate and efficient landmark recognition system is thus urgent for mobile applications. In this paper, we propose a landmark recognition framework by employing a novel discriminative feature selection method and the improved extreme learning machine (ELM) algorithm. The scalable vocabulary tree (SVT) is first used to generate a set of preliminary codewords for landmark images. An efficient codebook learning algorithm derived from the word mutual information and Visual Rank technique is proposed to filter out those unimportant codewords. Then, the selected visual words, as the codebook for image encoding, are used to produce a compact Bag-of-Words (BoW) histogram. The fast ELM algorithm and the ensemble approach using the ELM classifier are utilized for landmark recognition. Experiments on the Nanyang Technological University campus’s landmark database and the Fifteen Scene database are conducted to illustrate the advantages of the proposed framework.     

神经网络集成的多表情人脸识别方法

将神经网络集成应用于多表情人脸识别,通过二维主成分分析获得人脸表情特征,并为每一表情的特征空间各训练一个神经网络,利用另一神经网络对其进行集成。实验结果表明,多神经网络集成方法的识别精度高于单一神经网络所获得的结果。     

基于神经网络集成的汽车牌照识别

对基于神经网络集成的汽车牌照识别的原理和方法进行了研究,并着重分析了现有技术的积极因素和潜在问题,提出了一种基于神经网络集成进行车牌文字识别的方法.在特征提取时采用了多种特征提取的方法,对提取的每种特征构建一个BP神经网络分别进行训练.最终待识别的字符将被神经网络集成进行识别.实践证明,利用该方法比单个神经网络识别有更高的识别率,具有较高的使用价值.     

一种k均值和神经网络集成的语音识别方法

提出了一种基于k均值聚类和BP神经网络集成的语音识别方法,该方法以神经网络集成模型为基础,利用k均值聚类算法选择部分有差异性的个体神经网络再进行集成学习,既克服了单个BP网络模型容易局部收敛和不稳定性的缺点,又解决了传统集成方法训练时间长和个体网络差异性不明显的问题。通过对非特定人孤立词的语音识别的实验,证实了该方法的有效性。     

Bounds on the moments for an ensemble of random decision trees

Knowledge and Information Systems - An ensemble of random decision trees is a popular classification technique, especially known for its ability to scale to large domains. In this paper, we provide...     

Stacking-based ensemble learning of decision trees for interpretable prostate cancer detection

Prostate cancer is a highly incident malignant cancer among men. Early detection of prostate cancer is necessary for deciding whether a patient should receive costly and invasive biopsy with possible serious complications. However, existing cancer diagnosis methods based on data mining only focus on diagnostic accuracy, while neglecting the interpretability of the diagnosis model that is necessary for helping doctors make clinical decisions. To take both accuracy and interpretability into consideration, we propose a stacking-based ensemble learning method that simultaneously constructs the diagnostic model and extracts interpretable diagnostic rules. For this purpose, a multi-objective optimization algorithm is devised to maximize the classification accuracy and minimize the ensemble complexity for model selection. As for model combination, a random forest classifier-based stacking technique is explored for the integration of base learners, i.e., decision trees. Empirical results on real-world data from the General Hospital of PLA demonstrate that the classification performance of the proposed method outperforms that of several state-of-the-art methods in terms of the classification accuracy, sensitivity and specificity. Moreover, the results reveal that several diagnostic rules extracted from the constructed ensemble learning model are accurate and interpretable.     

改进Stacking集成学习的指纹识别算法

针对传统卷积神经网络对多传感器指纹识别泛化能力降低、准确率不高的问题,提出改进的Stacking集成学习算法。首先将AlexNet进行改进,在AlexNet中引入深度可分离卷积减少参数量,加快训练速度;引入空间金字塔池化,提升网络获取全局信息的能力;引入批归一化,加快网络收敛速度,同时提升网络在测试集上的准确率;使用全局平均池化替代全连接层,防止过拟合。然后将DenseNet和改进的AlexNet 2种卷积神经网络作为Stacking的基学习器对指纹进行分类,获得预测结果。最后对相同基学习器训练得到的各个模型,根据预测精度对各预测结果赋权,得到的预测结果再由元分类器分类。改进的Stacking算法在多传感器指纹数据库上进行实验,最终识别准确率达98.43%,相对AlexNet提升了20.05%,相对DenseNet提升了4.25%。     

基于Bagging集成学习的字符识别方法

针对字符识别对象的多样性,提出了一种基于Bagging集成的字符识别模型,解决了识别模型对部分字符识别的偏好现象。采用Bagging采样策略形成不同的数据子集,在此基础上用决策树算法训练形成多个基分类器,用多数投票机制对基分类器预测结果集成输出。理论分析与仿真实验结果表明,所提模型相比其他分类方法具有更好的分类能力。     

Identifying species of individual trees using airborne laser scanner

Individual trees can be detected using high-density airborne laser scanner data. Also, variables characterizing the detected trees such as tree height, crown area, and crown base height can be measured. The Scandinavian boreal forest mainly consists of Norway spruce (Picea abies L. Karst.), Scots pine (Pinus sylvestris L.), and deciduous trees. It is possible to separate coniferous from deciduous trees using near-infrared images, but pine and spruce give similar spectral signals. Airborne laser scanning, measuring structure and shape of tree crowns could be used for discriminating between spruce and pine. The aim of this study was to test classification of Scots pine versus Norway spruce on an individual tree level using features extracted from airborne laser scanning data. Field measurements were used for training and validation of the classification. The position of all trees on 12 rectangular plots (50×20 m²) were measured in field and tree species was recorded. The dominating species (>80%) was Norway spruce for six of the plots and Scots pine for six plots. The field-measured trees were automatically linked to the laser-measured trees. The laser-detected trees on each plot were classified into species classes using all laser-detected trees on the other plots as training data. The portion correctly classified trees on all plots was 95%. Crown base height estimations of individual trees were also evaluated (r=0.84). The classification results in this study demonstrate the ability to discriminate between pine and spruce using laser data. This method could be applied in an operational context. In the first step, a segmentation of individual tree crowns is performed using laser data. In the second step, tree species classification is performed based on the segments. Methods could be developed in the future that combine laser data with digital near-infrared photographs for classification with the three classes: Norway spruce, Scots pine, and deciduous trees.