Performance evaluation and implementations of MFCC, SVM and MLP algorithms in the FPGA board

One of the most difficult speech recognition tasks is accurate recognition of human-to-human communication. Advances in deep learning over the last few years have produced major speech improvements in recognition on the representative Switch-board conversational corpus. Word error rates that just a few years ago were 14% have dropped to 8.0%, then 6.6% and most recently 5.8%, and are now believed to be within striking range of human performance. This raises two issues - what is human performance, and how far down can we still drive speech recognition error rates? The main objective of this article is the development of a comparative study of the performance of Automatic Speech Recognition (ASR) algorithms using a database made up of a set of signals created by female and male speakers of different ages. We will also develop techniques for the Software and Hardware implementation of these algorithms and test them in an embedded electronic card based on a reconfigurable circuit (Field Programmable Gate Array FPGA). We will present an analysis of the results of classifications for the best Support Vector Machine architectures (SVM) and Artificial Neural Networks of Multi-Layer Perceptron (MLP). Following our analysis, we created NIOSII processors and we tested their operations as well as their characteristics. The characteristics of each processor are specified in this article (cost, size, speed, power consumption and complexity). At the end of this work, we physically implemented the architecture of the Mel Frequency Cepstral Coefficients (MFCC) extraction algorithm as well as the classification algorithm that provided the best results

Switching Time Optimization via Time Optimal Control for Natural Gas Vehicle Refueling

The implementation of Natural Gas Vehicle (NGV) refueling system using multipressure storage source requires a suitable controller to be developed. In this thesis, a refueling algorithm using Time Optimal Control (TOC) technique is proposed as a basis for determining the optimal switching time in NGV refueling using the mass and mass flowrate as the state variables, measured using Coriolis flowmeter. In order to implement TOC in actual NGV refueling process, a fully instrumented NGV laboratory test facility was designed and commissioned which includes three main parts: the NGV test rig, the Data Acquisition (DAQ) & Control System using FieldPoint, and the LabVIEW programming model. Performance measurements for experiments conducted at NGV test rig are based on two criteria, i. e., the refueling time and the total mass of natural gas stored. These become the performance measurements used to evaluate the performance of TOC and other NGV controller currently applied in the commercial NGV dispenser i. e., Kraus refueling algorithm. The performance of the refueling algorithms are evaluated based on three experiments: the first experiment is the performance of valves switching and refueling time transitions; the second experiment is the performance of refueling when the storage pressures are set to 3600 psig while the receiver tank is varied from 20 to 2000 psig; and the third experiment is the performance of refueling when the storage pressures are set to different pressures while the receiver tank is maintained at 20 psig. In conclusion, the results from the third experiment verifies the viability of TOC refueling compared to Kraus refueling to be used in NGV refueling using multi-pressure storage source, which average difference for refueling time and total mass loss are 25.33 seconds and 0.95 kg, respectively. By implementing the refueling algorithm in actual NGV refueling stations, it is expected to provide saving in term of the energy consumed by the compressor and contributing to the reduction in the NGV station congestion problem in the country

Freeform User Interfaces for Graphical Computing

報告番号: 甲15222 ; 学位授与年月日: 2000-03-29 ; 学位の種別: 課程博士 ; 学位の種類: 博士(工学) ; 学位記番号: 博工第4717号 ; 研究科・専攻: 工学系研究科情報工学専

Numerical Boundary Condition Procedures

Topics include numerical procedures for treating inflow and outflow boundaries, steady and unsteady discontinuous surfaces, far field boundaries, and multiblock grids. In addition, the effects of numerical boundary approximations on stability, accuracy, and convergence rate of the numerical solution are discussed

Linear and nonlinear aspects of the tropical 30-60 day oscillation: A modeling study

The scientific problem focused on study of the tropical 30-60 day oscillation and explanation for this phenomenon is discussed. The following subject areas are covered: the scientific problem (the importance of low frequency oscillations; suggested mechanisms for developing the tropical 30-60 day oscillation); proposed research and its objective; basic approach to research; and results (satellite data analysis and retrieval development; thermodynamic model of the oscillation; the 5-level GCM)

AFIT School of Engineering Contributions to Air Force Research and Technology. Calendar Year 1972

This report contains abstracts of Master of Science Theses, Doctoral Dissertations, and faculty publications completed during the 1972 calendar year at the School of Engineering, Air Force Institute of Technology, at Wright-Patterson Air Force Base, Ohio