Swaroop Damodaran, Ram Padmanabhan, R. Maahin, Sanjeev Gurugopinath
{"title":"A Copula-Driven Unsupervised Learning Framework for Anomaly Detection with Multivariate Heterogeneous Data","authors":"Swaroop Damodaran, Ram Padmanabhan, R. Maahin, Sanjeev Gurugopinath","doi":"10.1109/mlsp52302.2021.9596359","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596359","url":null,"abstract":"We consider the problem of anomaly detection with heterogeneous and correlated multivariate data, with no assumption on the knowledge of statistical correlation. First, we use a copula-based approach to measure the statistical correlation among the modalities. Next, we employ an unsupervised learning (UL) framework for anomaly detection, using data points sampled from the copula-based joint distribution. In particular, we consider Gaussian, R-Vine, D-Vine and C-Vine copula techniques, with isolation forest, one-class SVM, local outlier factor, elliptic envelope and autoencoder UL algorithms, for our extensive study. Through Monte Carlo simulations and an experimental study on the IEEE signal processing cup – 2020 dataset, we show that the proposed framework significantly outperforms the direct training method, in terms of detection accuracy. Furthermore, we show that the C-Vine-based autoencoder technique yields the best performance in comparison with other techniques, in terms of area under the receiver operating characteristics curve, and accuracy of detecting anomalies.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127389559","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":"Lightweight Forest Fire Detection Based on Deep Learning","authors":"Rui Fan, Mingtao Pei","doi":"10.1109/mlsp52302.2021.9596409","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596409","url":null,"abstract":"Forest fire detection is a challenging problem in computer vision. In this paper, we build a challenging fire dataset which contains images of fire, smoke, and red leaf to better simulate the real forest environment. We propose a lightweight network structure, YOLOv4-Light, for forest fire detection. The original YOLOv4's backbone feature extraction network is replaced by MobileNet, and PANet's standard convolution is replaced by depthwise separable convolution, which improves the detection speed and makes it more suitable for embedded devices. We also adjusted the YoloHead according to the relationship between smoke and flame to reduce the missing rate and false rate. The experimental results show that our YOLOv4-Light achieves good performance for forest fire detection, at the same time, our YOLOv4-Light achieves higher FPS and the model size is reduced by 4 times compared with other algorithms, which makes it easier to implement on embedded devices.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127501184","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}
Albert Podusenko, B. V. Erp, Dmitry V. Bagaev, Ismail Senöz, B. Vries
{"title":"Message Passing-Based Inference in the Gamma Mixture Model","authors":"Albert Podusenko, B. V. Erp, Dmitry V. Bagaev, Ismail Senöz, B. Vries","doi":"10.1109/mlsp52302.2021.9596329","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596329","url":null,"abstract":"The Gamma mixture model is a flexible probability distribution for representing beliefs about scale variables such as precisions. Inference in the Gamma mixture model for all latent variables is non-trivial as it leads to intractable equations. This paper presents two variants of variational message passing-based inference in a Gamma mixture model. We use moment matching and alternatively expectation-maximization to approximate the posterior distributions. The proposed method supports automated inference in factor graphs for large probabilistic models that contain multiple Gamma mixture models as plug-in factors. The Gamma mixture model has been implemented in a factor graph package and we present experimental results for both synthetic and real-world data sets.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129400313","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 Neural Beamforming Network for B-Format 3D Speech Enhancement and Recognition","authors":"Xinlei Ren, Lianwu Chen, Xiguang Zheng, Chenglin Xu, Xu Zhang, Chen Zhang, Liang Guo, Bin Yu","doi":"10.1109/mlsp52302.2021.9596418","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596418","url":null,"abstract":"Multi-channel speech enhancement is gaining increasing interest in recent years. By combining the beamforming framework with the deep neural network, significant improvement on speech enhancement performance has been achieved. While the neural beamformers designed for the distributed microphone arrays are deployed for practical applications such as teleconferencing and surveillance, there is less approach designed for the co-located microphone arrays such as the soundfield microphones. In this work, a new neural beamforming network is proposed for B-format 3D multi-channel speech enhancement and recognition. The proposed method incorporates the traditional beamforming structure with the deep neural network specifically for the B-format channels (the first-order Ambisonics). The proposed method has ranked the 1st place of the 3D Speech Enhancement task in the MLSP L3DAS21 Challenge while significantly outperformed the baseline system on the WER and STOI metrics.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130999422","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":"Convolutional Dense Neural Network Based Spirometry Variable FVC Prediction Using Sustained Phonations","authors":"Shivani Yadav, D. Gope, U. Krishnaswamy, P. Ghosh","doi":"10.1109/mlsp52302.2021.9596159","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596159","url":null,"abstract":"Spirometry is a lung function test used to diagnose and monitor lung diseases like asthma, pneumonia, chronic obstructive pulmonary disease, etc. Spirometry measures forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and their ratio to determine lung health. Spirometry is very time-consuming, strenuous, and requires proper training. Alternate methods based on voice for diagnosis and monitoring of lung health are promising because they are faster, easy to do, and require minimal training. Non-speech sounds, namely, cough and wheeze, have been used to predict spirometry variables, but the role of speech sounds that occur in natural speaking for a similar task has not been explored. In this work, the spirometry variable, FVC has been predicted from sustained phonations of vowel sounds using a convolutional dense neural network (CDNN). Mel-spectrogram has been used as a feature. An experiment conducted using 160 subjects indicates, /i/ is the best sound and /u:/ is worst for the prediction task with an average Mean Absolute Error of 0.67l(±. 07l) and 0.70l(± 0.13l) among all sustained phonations of vowels sounds considered in this work.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"284 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132278241","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":"Fast Subspace Clustering Algorithm with Efficient Similarity-Constrained Sampling for Hyperspectral Images","authors":"Jhon Lopez, Carlos Hinojosa, H. Arguello","doi":"10.1109/mlsp52302.2021.9596507","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596507","url":null,"abstract":"Hyperspectral images (HSIs) are high-dimensional and complex images that provide rich spectral information of the scenes. Image processing and remote sensing communities are currently developing unsupervised learning methods for HSI classification due to the lack of labeled data. Subspace clustering (SC) methods based on spectral clustering have achieved high clustering performance in real data experiments. However, the computational complexity of such methods prevents their use on large HSI since they require building a similarity matrix that should account for all the pixels in the image. This work proposes an efficient SC-based method that reduces the temporal and spatial computational complexity by splitting the HSI clustering task using similarity-constrained sampling, which considers the spatial information to boost the clustering performance. Experimental results on two widely used HSI data sets show the proposed method's effectiveness, outperforming the baseline methods in more than 20% of overall accuracy.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115604930","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":"Dynamic Graph Convolutional Network: A Topology Optimization Perspective","authors":"Bowen Deng, Aimin Jiang","doi":"10.1109/mlsp52302.2021.9596206","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596206","url":null,"abstract":"Recently, graph convolutional networks(GCNs) have drawn increasing attention in many domains, e.g., social networks, recommendation systems. It's known that, in the task of graph node classification, inter-class edges connecting nodes from different categories often degrade the GCN model performance. On the other hand, a stronger intra-class connection in terms of the edge number and edge weights is always beneficial to node classification. Most existing GCN models assume that the topology and edge weights of the underlying graph are both fixed. However, real-world networks are often noisy and incomplete. To take into account such uncertainty in graph topology, we propose in this paper a dynamic graph convolution network (DyGCN), where edge weights are treated as learnable parameters. A novel adaptive edge dropping (AdaDrop) strategy is developed for DyGCN, such that even graph topology can be optimized. DyGCN is also a flexible architecture that can be readily combined with other deep GCN models to cope with the oversmoothness encountered when the network goes very deep. Experimental results demonstrate that the proposed DyGCN and its deep variants can achieve competitive classification accuracy in many datasets.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125786317","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":"Understanding Linear Style Transfer Auto-Encoders","authors":"Ian Pradhan, Siwei Lyu","doi":"10.1109/mlsp52302.2021.9596412","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596412","url":null,"abstract":"Style transfer auto-encoder has recently been shown to be highly effective in synthesizing images with styles transferred from another image. In this work, we aim to provide an answer to this question by studying a simpler variant of STAE, namely, the linear style transfer auto-encoders (LinSTAEs), where the encoder and decoders are all linear models. We show that the objective function of LinSTAE, under the $ell_{2}$ loss, affords a simple form, and the optimal solutions reveal the mechanism how the encoder capture joint characteristics from the input and the target domain, and the decoders restore their idiosyncrasies. We further show that at least for the linear case, the cycle reconstruction loss is not necessary - the vanilla LinSTAE objective function is already effective. We use numerical experiments on the synthetic and the MNIST dataset to showcase our findings.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127362387","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":"Model Selection of Kernel Ridge Regression for Extrapolation","authors":"A. Tanaka, Masanari Nakamura, H. Imai","doi":"10.1109/mlsp52302.2021.9596089","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596089","url":null,"abstract":"Model selection of the kernel ridge regression is discussed in this paper. The cross-validation approach is one of popular and powerful model selection techniques for many machine learning methods including the kernel ridge regression. However, the cross-validation approach is not suitable for extrapolation scenarios due to its principle. In this paper, we propose a novel model selection criterion for the kernel ridge regression which is applicable to extrapolation scenarios. The key idea of the proposed criterion is direct evaluation of the generalization error, defined in a certain reproducing kernel Hilbert spaces, which is feasible under a certain assumption on a set of kernel candidates.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121627192","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":"Tracking of Quantized Signals Based on Online Kernel Regression","authors":"Emilio Ruiz Moreno, B. Beferull-Lozano","doi":"10.1109/mlsp52302.2021.9596115","DOIUrl":"https://doi.org/10.1109/mlsp52302.2021.9596115","url":null,"abstract":"Kernel-based approaches have achieved noticeable success as non-parametric regression methods under the framework of stochastic optimization. However, most of the kernel-based methods in the literature are not suitable to track sequentially streamed quantized data samples from dynamic environments. This shortcoming occurs mainly for two reasons: first, their poor versatility in tracking variables that may change unpredictably over time, primarily because of their lack of flexibility when choosing a functional cost that best suits the associated regression problem; second, their indifference to the smoothness of the underlying physical signal generating those samples. This work introduces a novel algorithm constituted by an online regression problem that accounts for these two drawbacks and a stochastic proximal method that exploits its structure. In addition, we provide tracking guarantees by analyzing the dynamic regret of our algorithm. Finally, we present some experimental results that support our theoretical analysis and show that our algorithm has a favorable performance compared to the state-of-the-art.","PeriodicalId":156116,"journal":{"name":"2021 IEEE 31st International Workshop on Machine Learning for Signal Processing (MLSP)","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129889758","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}