{"title":"Latent Dirichlet learning for hierarchical segmentation","authors":"Jen-Tzung Chien, C. Chueh","doi":"10.1109/MLSP.2012.6349772","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349772","url":null,"abstract":"Topic model can be established by using Dirichlet distributions as the prior model to characterize latent topics in natural language. However, topics in real-world stream data are non-stationary. Training a reliable topic model is a challenging study. Further, the usage of words in different paragraphs within a document is varied due to different composition styles. This study presents a hierarchical segmentation model by compensating the heterogeneous topics in stream level and the heterogeneous words in document level. The topic similarity between sentences is calculated to form a beta prior for stream-level segmentation. This segmentation prior is adopted to group topic-coherent sentences into a document. For each pseudo-document, we incorporate a Markov chain to detect stylistic segments within a document. The words in a segment are generated by identical composition style. This new model is inferred by a variational Bayesian EM procedure. Experimental results show benefits by using the proposed model in terms of perplexity and F measure.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130505885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A subspace learning algorithm for microwave scattering signal classification with application to wood quality assessment","authors":"Yinan Yu, T. McKelvey","doi":"10.1109/MLSP.2012.6349728","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349728","url":null,"abstract":"A classification algorithm based on a linear subspace model has been developed and is presented in this paper. To further improve the classification results, the full linear subspace of each class is split into subspaces with lower dimensions and characterized by local coordinates constructed from automatically selected training data. The training data selection is implemented by optimizations with least squares constraints or L1 regularization. The working application is to determine the quality in wooden logs using microwave signals [1]. The experimental results are shown and compared with classical methods.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130568049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Huttunen, Timo Erkkilä, P. Ruusuvuori, T. Manninen
{"title":"The eighth annual MLSP competition: Second place team","authors":"H. Huttunen, Timo Erkkilä, P. Ruusuvuori, T. Manninen","doi":"10.1109/MLSP.2012.6349770","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349770","url":null,"abstract":"This paper describes our submission to the eighth annual MLSP competition organized by Amazon during the 2012 IEEE MLSP workshop. Our approach is based on a nearest-neighbor-like classifier with a distance metric learned from samples. The method was second in the final standings with prediction accuracy of 81 %, while the winning submission was 87 % accurate.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131364043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comprehensive analysis of multiple microarray datasets by binarization of consensus partition matrix","authors":"Basel Abu-Jamous, Rui Fa, D. Roberts, A. Nandi","doi":"10.1109/MLSP.2012.6349787","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349787","url":null,"abstract":"Clustering methods have been increasingly applied over gene expression datasets. Different results are obtained when different clustering methods are applied over the same dataset as well as when the same set of genes is clustered in different microarray datasets. Most approaches cluster genes' profiles from only one dataset, either by a single method or an ensemble of methods; we propose using the binarization of consensus partition matrix (Bi-CoPaM) method to analyze comprehensively the results of clustering the same set of genes by different clustering methods and from different datasets. A tunable consensus result is generated and can be tightened or widened to control the assignment of the doubtful genes that have been assigned to different clusters in different individual results. We apply this over a subset of 384 yeast genes by using four clustering methods and five microarray datasets. The results demonstrate the power of Bi-CoPaM in fusing many different individual results in a tunable consensus result and that such comprehensive analysis can overcome many of the defects in any of the individual datasets or clustering methods.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134106908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Language informed bandwidth expansion","authors":"Jinyu Han, G. Mysore, Bryan Pardo","doi":"10.1109/MLSP.2012.6349783","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349783","url":null,"abstract":"High-level knowledge of language helps the human auditory system understand speech with missing information such as missing frequency bands. The automatic speech recognition community has shown that the use of this knowledge in the form of language models is crucial to obtaining high quality recognition results. In this paper, we apply this idea to the bandwidth expansion problem to automatically estimate missing frequency bands of speech. Specifically, we use language models to constrain the recently proposed non-negative hidden Markov model for this application. We compare the proposed method to a bandwidth expansion algorithm based on non-negative spectrogram factorization and show improved results on two standard signal quality metrics.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134214527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Joint feature and model training for minimum detection errors applied to speech subword detection","authors":"M. H. Johnsen, Alfonso M. Canterla","doi":"10.1109/MLSP.2012.6349729","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349729","url":null,"abstract":"This paper presents methods and results for joint optimization of the feature extraction and the model parameters of a detector. We further define a discriminative training criterion called Minimum Detection Error (MDE). The criterion can optimize the F-score or any other detection performance metric. The methods are used to design detectors of subwords in continuous speech, i.e. to spot phones and articulatory features. For each subword detector the MFCC filterbank matrix and the Gaussian means in the HMM models are jointly optimized. For experiments on TIMIT, the optimized detectors clearly outperform the baseline detectors and also our previous MCE based detectors. The results indicate that the same performance metric should be used for training and test and that accuracy outperforms F-score with respect to relative improvement. Furter, the optimized filterbanks usually reflect typical acoustic properties of the corresponding detection classes.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130030632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Facial expression recognition with robust covariance estimation and Support Vector Machines","authors":"N. Vretos, A. Tefas, I. Pitas","doi":"10.1109/MLSP.2012.6349762","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349762","url":null,"abstract":"In this paper, a new framework for facial expression recognition is presented. A Support Vector Machine (SVM) variant is proposed, which makes use of robust statistics. We investigate the use of statistically robust location and dispersion estimators, in order to enhance the performance of a facial expression recognition algorithm by using the support vector machines. The efficiency of the proposed method is tested for two-class and multi-class classification problems. In addition to the experiments conducted in facial expression database we also conducted experiments on classification databases to provide evidence that our method outperforms state of the art methods.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116833659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Handling missing features in maximum margin Bayesian network classifiers","authors":"Sebastian Tschiatschek, N. Mutsam, F. Pernkopf","doi":"10.1109/MLSP.2012.6349804","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349804","url":null,"abstract":"The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) records hydroacoustic data to detect nuclear explosions1. This enables verification of the Comprehensive Nuclear-Test-Ban Treaty once it has entered into force. The detection can be considered as a classification problem discriminating noise-like, earthquake-caused and explosion-like data. Classification of the recorded data is challenging because it suffers from large amounts of missing features. While the classification performance of support vector machines has been evaluated, no such results for Bayesian network classifiers are available. We provide these results using classifiers with generatively and discriminatively optimized parameters and employing different imputation methods. In case of discriminatively optimized parameters, Bayesian network classifiers slightly outperform support vector machines. For optimizing the parameters discriminatively, we extend the formulation of maximum margin Bayesian network classifiers to missing features and latent variables. The advantage of these classifiers over classifiers with generatively optimized parameters is demonstrated in experiments.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115278499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Context Dependent Spectral Unmixing","authors":"Hamdi Jenzri, H. Frigui, P. Gader","doi":"10.1109/MLSP.2012.6349750","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349750","url":null,"abstract":"A hyperspectral unmixing algorithm that finds multiple sets of endmembers is introduced. The algorithm, called Context Dependent Spectral Unmixing (CDSU), is a local approach that adapts the unmixing to different regions of the spectral space. It is based on a novel objective function that combines context identification and unmixing into a joint function. This objective function models contexts as compact clusters and uses the linear mixing model as the basis for unmixing. The unmixing provides optimal endmembers and abundances for each context. An alternating optimization algorithm is derived. The performance of the CDSU algorithm is evaluated using synthetic and real data. We show that the proposed method can identify meaningful and coherent contexts, and appropriate endmembers within each context.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116523807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Online learning with kernels: Overcoming the growing sum problem","authors":"Abhishek Singh, N. Ahuja, P. Moulin","doi":"10.1109/MLSP.2012.6349811","DOIUrl":"https://doi.org/10.1109/MLSP.2012.6349811","url":null,"abstract":"Online kernel algorithms have an important computational drawback. The computational complexity of these algorithms grow linearly over time. This makes these algorithms difficult to use for real time signal processing applications that need to continuously process data over prolonged periods of time. In this paper, we present a way of overcoming this problem. We do so by approximating kernel evaluations using finite dimensional inner products in a randomized feature space. We apply this idea to the Kernel Least Mean Square (KLMS) algorithm, that has recently been proposed as a non-linear extension to the famed LMS algorithm. Our simulations show that using the proposed method, constant computational complexity can be achieved, with no observable loss in performance.","PeriodicalId":262601,"journal":{"name":"2012 IEEE International Workshop on Machine Learning for Signal Processing","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114889002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}