Full-info Training for Deep Speaker Feature Learning

In recent studies, it has shown that speaker patterns can be learned from very short speech segments (e.g., 0.3 seconds) by a carefully designed convolutional & time-delay deep neural network (CT-DNN) model. By enforcing the model to discriminate the speakers in the training data, frame-level speaker features can be derived from the last hidden layer. In spite of its good performance, a potential problem of the present model is that it involves a parametric classifier, i.e., the last affine layer, which may consume some discriminative knowledge, thus leading to `information leak' for the feature learning. This paper presents a full-info training approach that discards the parametric classifier and enforces all the discriminative knowledge learned by the feature net. Our experiments on the Fisher database demonstrate that this new training scheme can produce more coherent features, leading to consistent and notable performance improvement on the speaker verification task.Comment: Accepted by ICASSP 201

A mixed precision Jacobi method for the symmetric eigenvalue problem

The eigenvalue problem is a fundamental problem in scientific computing. In this paper, we propose a mixed precision Jacobi method for the symmetric eigenvalue problem. We first compute the eigenvalue decomposition of a real symmetric matrix by an eigensolver at low precision and we obtain a low-precision matrix of eigenvectors. Then by using the modified Gram-Schmidt orthogonalization process to the low-precision eigenvector matrix in high precision, a high-precision orthogonal matrix is obtained, which is used as an initial guess for the Jacobi method. We give the rounding error analysis for the proposed method and the quadratic convergence of the proposed method is established under some sufficient conditions. We also present a mixed precision one-side Jacobi method for the singular value problem and the corresponding rounding error analysis and quadratic convergence are discussed. Numerical experiments on CPUs and GPUs are conducted to illustrate the efficiency of the proposed mixed precision Jacobi method over the original Jacobi method.Comment: 31 pages, 2 figure

Log-hyperconvexity index and Bergman kernel

We obtain a quantitative estimate of Bergman distance when $\Omega \subset \mathbb{C}^n$ is a bounded domain with log-hyperconvexity index $\alpha_l(\Omega)>\frac{n-1+\sqrt{(n-1)(n+3)}}{2}$, as well as the $A^2(\log A)^q$-integrability of the Bergman kernel $K_{\Omega}(\cdot, w)$ when $\alpha_l(\Omega)>0$

Deep factorization for speech signal

Various informative factors mixed in speech signals, leading to great difficulty when decoding any of the factors. An intuitive idea is to factorize each speech frame into individual informative factors, though it turns out to be highly difficult. Recently, we found that speaker traits, which were assumed to be long-term distributional properties, are actually short-time patterns, and can be learned by a carefully designed deep neural network (DNN). This discovery motivated a cascade deep factorization (CDF) framework that will be presented in this paper. The proposed framework infers speech factors in a sequential way, where factors previously inferred are used as conditional variables when inferring other factors. We will show that this approach can effectively factorize speech signals, and using these factors, the original speech spectrum can be recovered with a high accuracy. This factorization and reconstruction approach provides potential values for many speech processing tasks, e.g., speaker recognition and emotion recognition, as will be demonstrated in the paper.Comment: Accepted by ICASSP 2018. arXiv admin note: substantial text overlap with arXiv:1706.0177

Comparative Research on Reproduction Concept in US and China Copyright Laws

Relied on the development of reproducing technology, copyright law occurs and develops, and the right to reproduction is considered to be a key right for the owner of copyright right. However, with the rapid development of related technologies, changes have also taken place in the concept of reproduction. On a systematical analysis of the differences in reproduction right between US and China copyright law, a history and a forecasting view have been briefly outlined. The emphasis of the paper is placed on how to respond, and how to get a dynamic adjustment in the concept of reproduction while facing the impact of network communication by contrasting US with China copyright laws. And I also discuss the possible convergent characters of reproduction concept with each other. On the basis of analyzing and comparing, I hope to give a comparable understanding of reproduction concept in copyright laws of US and China, and suggest the needed reforms in the new run of revision of China Copyright Law

Design and characterization of a UHF diplexer/antenna combination

Wireless communication systems are important in modern day life. Applications of wireless communication systems are used everywhere around the world, such as cell phones, wireless entertainments, satellites and navigation services. Because of the high volume usage of various wireless signals' spectra, it is desired to design systems that can accept the frequencies of multiple signals. A combination of antenna and diplexers can achieve such functionality. With antennas operating in dual frequency and diplexers which separate the signals, dual-frequency signals can be effectively transferred through the wireless communication systems simultaneously. In this thesis, we simulate and characterize the behavior of antenna and diplexer functioning in dual frequency. For the antenna, a mathematical analysis and a circuit model analysis were conducted to replicate its behavior. On the other hand, several circuit designs and simulations have been performed for diplexers. Moreover, an initial implementation of a single-order diplexer is also discussed. After the measurement, we found reasonable results for the functionality of a single-order diplexer. We believe that this first step gives us a correct route to our final implementation goal. In the future, more implementation tasks can also be discussed. In addition to the implementation of a first-order diplexer, higher-order diplexers constructed on printed circuited board (PCB) can also be developed. Moreover, an implementation of a combinational matching network construction between antenna and diplexer can also be discussed

A novel fatigue assessment approach by Direct Steady Cycle Analysis (DSCA) considering the temperature-dependent strain hardening effect

A Direct Steady Cycle Analysis (DSCA) method within the Linear Matching Method (LMM) framework is proposed to assess the fatigue life accurately and efficiently for components with arbitrary geometries and cyclic loads. Temperature-dependent stress-strain relationships considering the strain hardening described by the Ramberg-Osgood (RO) formula are discussed and compared with those results obtained by the Elastic-Perfectly Plastic (EPP) model. Additionally, a Reversed Plasticity Domain Method (RPDM) based on the shakedown and ratchet limit analysis method and the DSCA approach within the LMM framework (LMM DSCA) is recommended to design cyclic load levels of Low Cycle Fatigue (LCF) experiments with predefined fatigue life ranges. Based on the ASME code, the material properties at the mean temperature through the wall thickness are used to assess the fatigue life. However, the proposed method can estimate the fatigue life considering the temperature-dependent material properties with strain hardening effect according to the temperature distribution, which is closer to the true operating condition