{"title":"Multi-Discriminator Distributed Generative Model for Multi-Layer RF Metasurface Discovery","authors":"J. Hodge, K. Mishra, A. Zaghloul","doi":"10.1109/GlobalSIP45357.2019.8969135","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969135","url":null,"abstract":"Metasurface-based antenna beam control is defining a new engineering paradigm in radio-frequency applications such as communications, radar, and analog spatial signal processing. Metasurfaces are composite electromagnetic material surfaces that are made of subwavelength scattering particles, or meta-atoms, with negligible thickness and optimized to control electromagnetic waves in unprecedented fashions through modified boundary conditions. Conventional metasurface design is a tedious process that requires iteratively solving Maxwell's equations. This becomes increasingly challenging as state-of-the-art metasurfaces require complex bi-anisotropic responses over multiple layers of meta- atoms and several frequency bands. In this paper, to reduce design time and optimization overhead, we employ a multi-discriminator distributed generative adversarial network for inverse design of multi- layer metasurfaces. Unlike conventional design approaches, our proposed approach is able to jointly design multiple layers, discover new meta- atom patterns, and avoid solving Maxwell’s equations numerically or analytically. Results show that generated triple-layer meta-atoms can achieve frequency resonances within 7% of the input values.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123920576","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}
Sahil Anchal, Bodhibrata Mukhopadhyay, Manohar Parvatini, Subrat Kar
{"title":"GMM-UBM based Person Verification using footfall signatures for Smart Home Applications","authors":"Sahil Anchal, Bodhibrata Mukhopadhyay, Manohar Parvatini, Subrat Kar","doi":"10.1109/GlobalSIP45357.2019.8969215","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969215","url":null,"abstract":"In this paper, we propose a novel person verification system based on footfall signatures using Gaussian Mixture Model-Universal Background Model (GMM-UBM). Ground vibration generated by footfall of an individual is used as a biometric modality. We conduct extensive experiments to compare the proposed technique with various baselines of footfall based person verification. The system is evaluated on an indigenous dataset containing 7750 footfall events of twenty subjects. Different scenarios are created for analyzing the robustness of the system by varying the number of registered and non registered users. We obtained a Half Total Error Rate (HTER) of 7% with the proposed model and achieved an overall performance gain of ~46% and ~33% over Support Vector Machine (SVM) and Convolution Neural Network (CNN) based techniques respectively. Experimental results validate the efficacy of the proposed algorithms.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121189978","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":"Covariance Matrix Decomposition Using Cascade of Linear Tree Transformations","authors":"N. T. Khajavi, A. Kuh","doi":"10.1109/GlobalSIP45357.2019.8969543","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969543","url":null,"abstract":"The tree model can be computed efficiently using the Chow-Liu algorithm to minimize the Kullback-Leibler (KL) divergence. This paper goes beyond tree approximations by systematically forming a cascade of linear transformations where each linear transformation represents a tree structure. The linear transformation is found via a Cholesky factorization to provide sparsity to the inverse covariance matrix. We show that each successive additional cascade linear transformation improves the approximation with respect to the KL divergence. We conclude by showing some simulation results on synthetic data examining the quality of tree and non-tree approximations.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121212643","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":"Towards a Graph Signal Processing Framework for Modeling Power System Dynamics","authors":"Xinyue Hu, Zhi-Li Zhang","doi":"10.1109/GlobalSIP45357.2019.8969365","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969365","url":null,"abstract":"The conventional approaches for modeling dynamic systems are based on state-space methods using differential algebraic equations (DAEs). Such models not only require that the system dynamics can be precisely captured and expressed in mathematical equations, but also need detailed knowledge about the system parameters. Even when such DAEs are available, no closed-form solutions are available, and numerical solutions can be computationally expensive. As an example, modern power systems are typically large complex networks comprising of hundreds or even thousands of buses. The dimension of the mathematical models can easily reach the order of several thousands of state variables for dynamic simulation, trajectory sensitivity analysis, control, and so forth. Therefore, analyzing these extremely high-order DAEs poses a huge computational burden [1] .","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129318117","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}
Naresh Nagabushan, Taber Fisher, G. Malaty, M. Witcher, S. Vijayan
{"title":"A comparative study of motor imagery based BCI classifiers on EEG and iEEG data","authors":"Naresh Nagabushan, Taber Fisher, G. Malaty, M. Witcher, S. Vijayan","doi":"10.1109/GlobalSIP45357.2019.8969540","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969540","url":null,"abstract":"There are many state-of-the-art Brain Computer Interface (BCI) classification algorithms designed to perform well when applied to signals acquired using electroencephalography (EEG). EEG has the advantage of being non-invasive in nature, easy to use, and effective in capturing signals in the mu (7-13 Hz) and beta (13-30 Hz) bands during motor imagery tasks. However, EEG recordings are more susceptible to movement artifacts and capture a lower frequency of neural activity when compared with invasive techniques such as electrocorticography (ECoG) or intracranial EEG (iEEG). In this paper, we analyze the performance of four different EEG motor imagery classification algorithms (both classical machine learning methods and deep learning-based methods) on a two-hand motor imagery task using both EEG and iEEG data sets. Using various feature visualization techniques, we provide insight into why deep learning-based classifiers designed to learn features end-to-end may perform better than the classical machine learning-based models. We also showed on average iEEG-based motor imagery BCIs, using our iEEG data set, do not perform as well as EEG-based BCIs. This work provides a starting point for the implementation of BCI applications using iEEG data.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128669254","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":"Low-complexity Proximal Gauss-Newton Algorithm for Nonnegative Matrix Factorization","authors":"Kejun Huang, Xiao Fu","doi":"10.1109/GlobalSIP45357.2019.8969492","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969492","url":null,"abstract":"In this paper we propose a quasi-Newton algorithm for the celebrated nonnegative matrix factorization (NMF) problem. The proposed algorithm falls into the general framework of Gauss-Newton and Levenberg-Marquardt methods. However, these methods were not able to handle constraints, which is present in NMF. One of the key contributions in this paper is to apply alternating direction method of multipliers (ADMM) to obtain the iterative update from this Gauss-Newton-like algorithm. Furthermore, we carefully study the structure of the Jacobian Gramian matrix given by the Gauss-Newton updates, and designed a way of exactly inverting the matrix with complexity $mathcal{O}$(mnk), which is a significant reduction compared to the naive implementation of complexity $mathcal{O}$((m + n)3k3). The resulting algorithm, which we call NLS-ADMM, enjoys fast convergence rate brought by the quasi-Newton algorithmic framework, while maintaining low per-iteration complexity similar to that of alternating algorithms. Numerical experiments on synthetic data confirms the efficiency of our proposed algorithm.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"346 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115689707","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. Zhang, Zhenyu Liu, Guanwen Zhang, Jiwu Dai, Xiaocong Lian, W. Zhou, Xiangyang Ji
{"title":"A Block-Floating-Point Arithmetic Based FPGA Accelerator for Convolutional Neural Networks","authors":"H. Zhang, Zhenyu Liu, Guanwen Zhang, Jiwu Dai, Xiaocong Lian, W. Zhou, Xiangyang Ji","doi":"10.1109/GlobalSIP45357.2019.8969292","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969292","url":null,"abstract":"Convolutional neural networks (CNNs) have been widely used in computer vision applications and achieved great success. However, large-scale CNN models usually consume a lot of computing and memory resources, which makes it difficult for them to be deployed on embedded devices. An efficient block-floating-point (BFP) arithmetic is proposed in this paper. compared with 32-bit floating-point arithmetic, the memory and off-chip bandwidth requirements during convolution are reduced by 50% and 72.37%, respectively. Due to the adoption of BFP arithmetic, the complex multiplication and addition operations of floating-point numbers can be replaced by the corresponding operations of fixed-point numbers, which is more efficient on hardware. A CNN model can be deployed on our accelerator with no more than 0.14% top-1 accuracy loss, and there is no need for retraining and fine-tuning. By employing a series of ping-pong memory access schemes, 2-dimensional propagate partial multiply-accumulate (PPMAC) processors, and an optimized memory system, we implemented a CNN accelerator on Xilinx VC709 evaluation board. The accelerator achieves a performance of 665.54 GOP/s and a power efficiency of 89.7 GOP/s/W under a 300 MHz working frequency, which outperforms previous FPGA based accelerators significantly.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"254 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114326059","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}
Tian Xia, Xianfeng Rui, Chien-Lin Huang, I. Chu, Shaojun Wang, Mei Han
{"title":"An Attention Based Deep Neural Network for Automatic Lexical Stress Detection","authors":"Tian Xia, Xianfeng Rui, Chien-Lin Huang, I. Chu, Shaojun Wang, Mei Han","doi":"10.1109/GlobalSIP45357.2019.8969232","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969232","url":null,"abstract":"Lexical stress detection is one of important tasks in self-directed language learning application. We address this task by leveraging two successful attention techniques in natural language processing, inner attention and self-attention. First, combined with LSTM to model time-series features, inner attention could extract most important information and then convert length-varying input into a fixed-length feature vector; Second, self-attention intrinsically supports words with different number of syllables as input to model contexture information. Besides, our model is straightforward to expand to include hand-crafted features to further improve performance, and also can be applied to similar tasks, such as pitch accent detector. Experiments on LibriSpeech, TedLium and a third self-recored datasets show the high performance of our proposed attention based neural network.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115745559","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}
Ehsan Shahrabi Farahani, S. H. Choudhury, F. Costello, B. Goodyear, Michael R. Smith
{"title":"New Filtering Approaches to Improve the Classification Capability of Resting-state fMRI Transfer Functions","authors":"Ehsan Shahrabi Farahani, S. H. Choudhury, F. Costello, B. Goodyear, Michael R. Smith","doi":"10.1109/GlobalSIP45357.2019.8969301","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969301","url":null,"abstract":"Resting-state functional magnetic resonance imaging (fMRI) uses spontaneous regional brain activity to identify functional networks. Transfer functions (TF) can evaluate the amplification of resting-state fMRI signal frequency components from one brain region to another, but are highly susceptible to noise spikes. Resting-state fMRI’s low-temporal resolution implies that the high frequency noise characteristics necessary to implement Weiner filtering are not available. We investigated new approaches that replace the standard Weiner filter noise parameter with an alternative outlier suppression parameter (OSP) to identify and remove inaccurate TF estimates. When compared to standard TF approaches, our new filtering approaches shows an improved ability to distinguish optic neuritis (ON) patients from healthy volunteers, as well as patients experiencing ON as a clinically isolated syndrome (CIS) from ON patients with relapsing-remitting multiple sclerosis (RRMS).","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115810780","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":"Robust Direction of Arrival Estimation in the Presence of Array Faults using Snapshot Diversity","authors":"Gary C. F. Lee, A. Rawat, G. Wornell","doi":"10.1109/GlobalSIP45357.2019.8969105","DOIUrl":"https://doi.org/10.1109/GlobalSIP45357.2019.8969105","url":null,"abstract":"Many direction-of-arrival (DOA) estimation algorithms require accurate measurements from all sensing elements on an antenna array. However, in various practical settings, it becomes imperative to perform DOA estimation even in the presence of faulty elements. In this work, we develop an algorithm that can jointly estimate the DOA of sources and the locations of the faulty elements. This is achieved by introducing weights that describe the degree of outlierness of each element. Further, for situations where only single snapshots are available, we propose a new snapshot diversity formulation for which our algorithm can still be applied. Simulation results over four different fault models demonstrate that the proposed algorithm robustly estimates DOAs and accurately identifies the faulty elements.","PeriodicalId":221378,"journal":{"name":"2019 IEEE Global Conference on Signal and Information Processing (GlobalSIP)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116227734","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}