Multi-class Support Vector Machine Approach Research Articles

Monitoring based on Analytical Redundancy and Classification for a Primary Flight Surface Electromechanical Actuator

Our objective is to develop a monitoring algorithm that achieves early detection of degradations that may lead to jamming or excessive backlash in the electromechanical actuators (EMAs) used for primary fight control. To do so, a detailed EMA model is determined in order to construct a simulator able to reproduce test bench results and simulate faulty behaviours. Exploiting the analytical redundancy within the dynamical model of the EMA, a residual generator is designed to be sensitive to a potential friction change or backlash increase, by using the typical measurement sequences associated to pre-flight test profiles. A classifier based on a multiclass Support Vector Machine approach is used to detect and identify the nature of the faults. The classifier validity is corroborated by a K-fold cross-validation. Finally, tests are conducted on the simulator under various friction and backlash situations. The tests are performed under faults of realistic amplitude while considering uncertainties in the model parameters. The developed algorithm ensures the identification of the change in the friction and/or backlash with a successful classification rate of 98.13%.

Opinion mining for multiple types of emotion-embedded products/services through evolutionary strategy

Since the advent of blogging, microblogging, and social networking sites, researchers and practitioners have been increasingly concerned with the problem of obtaining useful evaluations from web-based opinion articles in a process known as opinion mining or sentiment analysis. In this study, we focused on reviews based on highly emotion-embedded products/services, such as movies, music, and drama. Furthermore, we tried to solve the multiple polarities problem for the same review word for multiple types of product/service. First, we collected text written in Chinese from a Taiwanese movie forum. In our proposed approach, we applied an evolutionary strategy algorithm to optimize the weight tables corresponding to two different types of movies: horror and drama movies. The experimental results indicated that the proposed method performed better than conventional methods when considering only one generalized type. Further, we employed a new multi-class support vector machine approach for predicting opinions at the document level. We used seven measures to describe the characteristics of an overall document, including the central tendency, dispersion, and shape of the predicted sentence value distribution, where the fluctuations in these values corresponded to their positions in the document. We also demonstrated the effectiveness of this approach for identifying opinions at the document level.

Taxonomy of Induction-Motor Mechanical-Fault Based on Time-Domain Vibration Signals by Multiclass SVM Classifiers

In the present work, faults in induction motors (IM) have been diagnosed by multiclass support vector machine (SVM) algorithms based on time domain vibration signals. The main focus is to classify mechanical faults of induction motors, i.e. the bearing fault, unbalanced rotor, bowed rotor and rotor misalignment at different rotational speeds and diverse loading conditions. In this work, an induction motor test setup was used to generate vibration signals of seeded mechanical faults. For the effective fault diagnosis, one-versus-one multiclass SVM approach with the Gaussian-radial basis function (RBF) kernel has been used. For the fault classification, firstly optimum statistical features from higher statistical moments have been selected. Also the selection of SVM kernel parameters, numbers of feature datasets and optimum ratio of training-to-testing data have been performed. The SVM classifier is trained and tested at the same rotational speeds as the measured data as well as innovatively tested at intermediate rotational speeds for which measured data was not available. It is observed that classification accuracy gradually increases with the increase of the rotational speed and with the increase of the load on the IM.

Phylogeography and support vector machine classification of colour variation in panther chameleons.

Lizards and snakes exhibit colour variation of adaptive value for thermoregulation, camouflage, predator avoidance, sexual selection and speciation. Furcifer pardalis, the panther chameleon, is one of the most spectacular reptilian endemic species in Madagascar, with pronounced sexual dimorphism and exceptionally large intraspecific variation in male coloration. We perform here an integrative analysis of molecular phylogeography and colour variation after collecting high‐resolution colour photographs and blood samples from 324 F. pardalis individuals in locations spanning the whole species distribution. First, mitochondrial and nuclear DNA sequence analyses uncover strong genetic structure among geographically restricted haplogroups, revealing limited gene flow among populations. Bayesian coalescent modelling suggests that most of the mitochondrial haplogroups could be considered as separate species. Second, using a supervised multiclass support vector machine approach on five anatomical components, we identify patterns in 3D colour space that efficiently predict assignment of male individuals to mitochondrial haplogroups. We converted the results of this analysis into a simple visual classification key that can assist trade managers to avoid local population overharvesting.

A multi-class SVM approach based on the l1-norm minimization of the distances between the reduced convex hulls

Multi-class classification is an important pattern recognition task that can be addressed accurately and efficiently by Support Vector Machine (SVM). In this work we present a novel SVM-based multi-class classification approach based on the center of the configuration, a point which is equidistant to all classes. The center of the configuration is obtained from the dual formulation by minimizing the distances between the reduced convex hulls using the l1-norm, while the decision functions are subsequently constructed from this point. This work also extends the ideas of Zhou et al. (2002) [37] to multi-class classification. The use of l1-norm provides a single linear programming formulation, which reduces the complexity and confers scalability compared with other multi-class SVM methods based on quadratic programming formulations. Experiments on benchmark datasets demonstrate the virtues of our approach in terms of classification performance and running times compared with various other multi-class SVM methods.

Classifying RNA-Binding Proteins Based on Electrostatic Properties

Protein structure can provide new insight into the biological function of a protein and can enable the design of better experiments to learn its biological roles. Moreover, deciphering the interactions of a protein with other molecules can contribute to the understanding of the protein's function within cellular processes. In this study, we apply a machine learning approach for classifying RNA-binding proteins based on their three-dimensional structures. The method is based on characterizing unique properties of electrostatic patches on the protein surface. Using an ensemble of general protein features and specific properties extracted from the electrostatic patches, we have trained a support vector machine (SVM) to distinguish RNA-binding proteins from other positively charged proteins that do not bind nucleic acids. Specifically, the method was applied on proteins possessing the RNA recognition motif (RRM) and successfully classified RNA-binding proteins from RRM domains involved in protein–protein interactions. Overall the method achieves 88% accuracy in classifying RNA-binding proteins, yet it cannot distinguish RNA from DNA binding proteins. Nevertheless, by applying a multiclass SVM approach we were able to classify the RNA-binding proteins based on their RNA targets, specifically, whether they bind a ribosomal RNA (rRNA), a transfer RNA (tRNA), or messenger RNA (mRNA). Finally, we present here an innovative approach that does not rely on sequence or structural homology and could be applied to identify novel RNA-binding proteins with unique folds and/or binding motifs.

조명 변화에 안정적인 손 형태 인지 기술

본 논문은 조명의 변화가 심한 영상에서 손 형태를 안정적으로 인지하는 기법에 관한 것이다. 제안한 방법은 HSI 색상공간에서 색상(Hue) 및 색상 기울기(Hue-Gradient)를 기반으로 정의된 배경모델을 구축하고, 실시간으로 입력되는 영상과의 배경차분(background subtraction)기법을 이용하여 배경과 손을 구분한다. 추출된 손의 영역으로부터 18가지의 특징요소를 추출하고 이를 기반으로 다중클래스 SVM(Support Vector Machine) 학습 기법을 사용하여 손의 형태를 인지한다. 제안 기법은 색상 기울기를 배경 차분에 적용함으로써, 조명 환경이 배경 모델의 조명과 다르게 급격한 변화가 이루어졌을 때도 안정적으로 손의 윤곽정보를 추출할 수 있도록 하였다. 또한, 실시간 처리를 저해하는 복잡한 손의 특성정보 대신, OBB의 크기에 대하여 정규화된 두 개의 고유값과 객체 기반 바운딩 박스(OBB)를 구성하는 16개 세부 영역에서의 손 윤곽픽셀의 개수를 손의 특성정보로 사용하였다. 본 논문에서는 급격한 조명 변화 상황에서 기존 RGB 색상요소를 기반으로 하는 배경차분법과 색상을 기반으로 하는 배경차분법, 본 논문에서 제안하는 색상 기울기 기반 배경 차분법의 결과를 비교함으로써 제안 기법의 안정성을 입증하였다. 6명의 실험대상자의 1부터 9까지의 수지화 2700개의 영상으로부터 손 특성 정보를 추출하고 이에 대하여 훈련을 통한 학습 모델을 생성하였다. 학습모델을 기반으로 실험자 6인의 손 형태 1620개의 데이터에 대하여 인지 실험을 실시하여 92.6%에 이르는 손 형태 인식 성공률을 얻었다. In this paper, we present a robust hand recognition approach to sudden illumination changes. The proposed approach constructs a background model with respect to hue and hue gradient in HSI color space and extracts a foreground hand region from an input image using the background subtraction method. Eighteen features are defined for a hand pose and multi-class SVM(Support Vector Machine) approach is applied to learn and classify hand poses based on eighteen features. The proposed approach robustly extracts the contour of a hand with variations in illumination by applying the hue gradient into the background subtraction. A hand pose is defined by two Eigen values which are normalized by the size of OBB(Object-Oriented Bounding Box), and sixteen feature values which represent the number of hand contour points included in each subrange of OBB. We compared the RGB-based background subtraction, hue-based background subtraction and the proposed approach with sudden illumination changes and proved the robustness of the proposed approach. In the experiment, we built a hand pose training model from 2,700 sample hand images of six subjects which represent nine numerical numbers from one to nine. Our implementation result shows 92.6% of successful recognition rate for 1,620 hand images with various lighting condition using the training model.

Prediction of Protein Secondary Structure with two-stage multi-class SVMs

Bioinformatics techniques to Protein Secondary Structure (PSS) prediction mostly depend on the information available in amino acid sequences. In this paper, we propose a two-stage Multi-class Support Vector Machine (MSVM) approach, where the second MSVM predictor is introduced at the output of the first stage MSVM to capture the contextual relationship among secondary structure elements in order to minimise the generalisation error in the prediction. By using position-specific scoring matrices generated by PSI-BLAST, the two-stage MSVM approach achieves Q3 accuracies of 78.0% and 76.3% on the RS126 dataset of 126 non-homologous globular proteins and the CB396 dataset of 396 non-homologous proteins, respectively, which are better than the scores reported on both datasets to date. By using MSVM, the present prediction scheme significantly achieves 2-6% and 3-15% of improvement in Q3 and Sov accuracies, respectively, on the two datasets. On larger blind-test datasets from PSIPRED, CASP4 and EVA datasets, two-stage MSVM approach achieves Q3 accuracies from 77.0% to 79.5%.