检索结果-内蒙古大学图书馆

4th International Power Electronics and Motion Control Conference (IPEMC 2004)

作者： Konghirun, M Xu, LY Skinner-Gray, J King Mongkuts Univ Technol Thonburi Dept Elect Engn Bangkok 10140 Thailand

ISBN: (纸本)7560518699

When implementing a motor control drive scheme digitally, the quantization errors always exist in the system. Two major sources of quantization errors are Analog-to-Digital (A-D) process and numerical calculation in the fixed-point computing device. Typically, the effects of quantization errors due to A-D conversion contribute less than one produced by numerical calculation. This paper studies the quantization errors in a sensorless direct vector control system of induction motor system using a 32-bit fixed-point Digital Signal Processor (DSP) from Texas Instruments (TMS320x28xx series). The investigation of quantization errors produced by numerical computation in such DSP is focused. Both simulation and experiment are carried out within DSP itself in three kinds of data formats;16-bit fixed-point, 32-bit fixed-point, and floating-point. By comparing the results between floating-point and fixed-point implementation on one machine, numerical issues related to quantization errors can be verified and resolved. As a result, the system performance and behavior can be affected by quantization errors in 16-bit word length while it is not significant in the 32-bit word length.

关键词： components quantization errors digital motor control systems fixed-point digital controller

来源：评论

学校读者我要写书评

暂无评论

Dispersion Compensation FIR Filter With Improved Robustness to Coefficient quantization errors

引用

JOURNAL OF LIGHTWAVE TECHNOLOGY 2016年第22期34卷 5110-5117页

作者： Sheikh, Alireza Fougstedt, Christoffer Graell i Amat, Alexandre Johannisson, Pontus Larsson-Edefors, Per Karlsson, Magnus Chalmers Univ Technol Dept Signals & Syst SE-41296 Gothenburg Sweden Chalmers Univ Technol Dept Comp Sci & Engn SE-41296 Gothenburg Sweden Chalmers Univ Technol Photon Lab SE-41296 Gothenburg Sweden

In this paper, we propose a new finite impulse response (FIR) filter for chromatic dispersion compensation which is given in closed form. We identify a relation between the out-of-band gain and the in-band error when the filter is implemented with finite-precision arithmetic. In particular, a large out-of-band gain makes the filter more sensitive to coefficient quantization errors due to finite precision digital signal processing. To improve robustness to coefficient quantization errors, our proposed filter is designed based on confining the out-of-band gain. By means of simulations, we show that our filter outperforms other existing FIR filters. The performance gain improves with increasing-modulation order and decreasing number of bits used to represent the filter taps.

关键词： Chromatic dispersion compensation constrained least-squares FIR filter quantization errors

来源：评论

学校读者我要写书评

暂无评论

Software and Hardware Techniques for Reducing the Impact of quantization errors in Memristor Crossbar Arrays 36

Software and Hardware Techniques for Reducing the Impact of ...

引用

36th IEEE International Conference on Computer Design (ICCD)

作者： Zhang, Baogang Ewetz, Rickard Univ Cent Florida Dept Elect & Comp Engn Orlando FL 32816 USA

ISBN: (纸本)9781538684771

Matrix-vector multiplication is the dominating computational workload in the evaluation of neural networks. It has recently been demonstrated that memristor crossbar arrays (MCAs) can perform matrix-vector multiplication with small power consumption and low latency. However, the computational accuracy may be degraded by quantization errors. The quantization errors of mapping a matrix to an MCA are proportional to the the number of distinguishable states of each memristor and the difference between the largest and smallest element in the matrix. In this paper, we propose a framework for mapping an arbitrary matrix A to a grid of MCAs (or a single MCA) while minimizing the negative impact of quantization errors. The framework is guided by a total quantization error bound (TQEB) metric, which is an upper bound on the total quantization errors (TQE). Using the proposed TQEB metric, three techniques of reducing TQE are proposed. The first method is based on scaling and shifting the rows in A with different factors to improve the memristor conductance band utilization. The second technique is based on representing a single column in a matrix A using multiple columns in an MCA, to reduce the magnitude of the smallest and largest elements in A. The third technique is based on permuting the order of the columns in A when the matrix A is required to be mapped to a grid of MCAs. The quantization errors are reduced by assigning matrix values of similar magnitude to the same MCAs in the grid. The experimental results demonstrate that the proposed metric and techniques are capable of greatly reducing the negative impact of quantization errors.

关键词： Memristors quantization errors analog computing neural networks

来源：评论

学校读者我要写书评

暂无评论

Research on quantization errors of Stability for Model-Based Networked Control System

Research on Quantization Errors of Stability for Model-Based...

引用

4th International Conference on Modelling,Identification and Control(ICMIC 2012)

作者： Lu Zhongda is with the College of Computer and Control Engineering of Qiqihar University, Qiqihar Heilongjiang China,Xu Fengxia is with the College of Computer and Control Engineering of Qiqihar University, Qiqihar Heilongjiang China, Tian Qunhong is with the College of Computer and Control Engineering of Qiqihar University, Qiqihar Heilongjiang China

In this paper, stability conditions for MB-NCS under popular quantization schemes are derived. Static quantizers have quantization schemes that do not vary with time, that is the error between the quantized value and the real value does not depend on time. Two quantizers of this type are considered: the Uniform Quantizer with a constant maximum quantization error;and the Logarithmic Quantizer with a maximum quantization error that is proportional to the norm of the quantized value. Dynamic Quantizers are introduced, these quantizers dynamically adjust their quantization regions to compensate for uncertainties while giving a quantization error that shrinks with time.

关键词： quantization errors Static quantization Dynamic quantization Networked Control Systems (MB-NCS) Logarithmic Quantizer

来源：评论

学校读者我要写书评

暂无评论

Low Roundoff Noise of Two Sparse Second-Order Balanced Realization-Based Structures

引用

CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2025年第2期44卷 1260-1273页

作者： Huang, Chaogeng Wu, Haiyan Chen, Yanhong Zhang, Houqi Song, Haiyu Zhejiang Univ Finance & Econ Sch Informat Hangzhou 310018 Zhejiang Peoples R China

In this paper, two second-order state-space digital filter structures are derived based on an input balanced realization, and these two filter structures are transposes of each other under an l2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$l_2$$\end{document}-norm dynamic range constraint. Each of the new second-order realizations has only 8 multipliers, which is one multiplier less than the standard state-space realization. The expressions of the roundoff noise gain for these structures are provided. Simulation results are presented to demonstrate the excellent finite wordlength performance of the proposed two sparse structures. The results show that the two proposed structures surpass both the classical optimal state-space realization and the normalized structure in minimizing roundoff noise, especially the transposed one produces the lowest roundoff noise.

关键词： Filter structure quantization errors State-space realization Roundoff noise Hardware architectures

来源：评论

学校读者我要写书评

暂无评论

Distributed H_∞ Filtering for a Class of Markovian Jump Nonlinear Time-Delay Systems Over Lossy Sensor Networks

引用

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2013年第10期60卷 4665-4672页

作者： Dong, Hongli Wang, Zidong Gao, Huijun Northeast Petr Univ Coll Elect & Informat Engn Daqing 163318 Peoples R China Harbin Inst Technol Res Inst Intelligent Control & Syst Harbin 150001 Peoples R China Tsinghua Univ Dept Automat Beijing 100084 Peoples R China Brunel Univ Dept Informat Syst & Comp Uxbridge UB8 3PH Middx England

This paper is concerned with the distributed H-infinity filtering problem for a class of discrete-time Markovian jump nonlinear time-delay systems with deficient statistics of mode transitions. The system measurements are collected through a lossy sensor network subject to randomly occurring quantization errors and randomly occurring packet dropouts. The description of deficient statistics of mode transitions that account for known, unknown, and uncertain transition probabilities is comprehensive. A distributed filter design scheme is outlined by explicitly characterizing the filter gains in terms of some matrix inequalities. Simulation results demonstrate the effectiveness of the proposed filtering scheme.

关键词： Deficient statistics of mode transitions distributed filtering lossy sensor networks packet losses quantization errors

来源：评论

学校读者我要写书评

暂无评论

Refined Reliability Combining for Binary Message Passing Decoding of Product Codes

引用

JOURNAL OF LIGHTWAVE TECHNOLOGY 2021年第15期39卷 4958-4973页

作者： Sheikh, Alireza Amat, Alexandre Liva, Gianluigi Alvarado, Alex IMEC Holst Ctr NL-5656 AE Eindhoven Netherlands Eindhoven Univ Technol Dept Elect Engn NL-5600 MB Eindhoven Netherlands Chalmers Univ Technol Dept Elect Engn SE-41296 Gothenburg Sweden German Aerosp Ctr DLR Inst Commun & Nav D-82234 Wessling Germany

We propose a novel soft-aided iterative decoding algorithm for product codes (PCs). The proposed algorithm, named iterative bounded distance decoding with combined reliability (iBDD-CR), enhances the conventional iterative bounded distance decoding (iBDD) of PCs by exploiting some level of soft information. In particular, iBDD-CR can be seen as a modification of iBDD where the hard decisions of the row and column decoders are made based on a reliability estimate of the BDD outputs. The reliability estimates are derived by analyzing the extrinsic message passing of generalized low-density-parity check (GLDPC) ensembles, which encompass PCs. We perform a density evolution analysis of iBDD-CR for transmission over the additive white Gaussian noise channel for the GLDPC ensemble. We consider both binary transmission and bit-interleaved coded modulation with quadrature amplitude modulation. We show that iBDD-CR achieves performance gains up to 0.51 dB compared to iBDD with the same internal decoder data flow. This makes the algorithm an attractive solution for very high-throughput applications such as fiber-optic communications.

关键词： Decoding Iterative decoding Reliability Message passing Encoding Throughput Product codes Binary message passing bounded distance decoding complexity high speed communications hard decision decoding product codes quantization errors

来源：评论

学校读者我要写书评

暂无评论

Digital-to-Time Synthesizers: Separating Delay Line Error Spurs and quantization Error Spurs

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2013年第10期60卷 2597-2605页

作者： Talwalkar, Sumit A. Motorola Solut Inc Plantation FL 33322 USA

This paper analyzes the spurs due to delay line (DL) buffer mismatch errors and phase quantization errors in a digital-to-time conversion (DTC) direct frequency synthesizer. Applying the time/frequency axis scaling property of the Discrete Fourier Transform (DFT) to a close approximation of the general case of both buffer error and quantization error spurs, it is shown that the spur spectra for all possible output frequencies can be divided into a very small number of classes. All the spectra within a class are scaled and systematically re-arranged versions of each other. For a DTC with a phase accumulator with I integer and M fractional bits, this result simplifies the number of spectra from 2(I+M) to M. The condition that allows separation of the buffer errors spur locations from the quantization error spur location is derived. Spurs predicted based on the analysis match closely with actual measurements performed on a 90 nm CMOS DTC synthesizer. The spur analysis also applies to the flying adder (FA) synthesizer.

关键词： Buffer errors delay line (DL) DFT axis scaling property digital-to-time converter (DTC) synthesizer flying adder mismatch errors quantization errors

来源：评论

学校读者我要写书评

暂无评论

Characterizing Coherent Integrated Photonic Neural Networks Under Imperfections

引用

JOURNAL OF LIGHTWAVE TECHNOLOGY 2023年第5期41卷 1464-1479页

作者： Banerjee, Sanmitra Nikdast, Mahdi Chakrabarty, Krishnendu Duke Univ Dept Elect & Comp Engn Durham NC 27708 USA Colorado State Univ Dept Elect & Comp Engn Ft Collins CO 80523 USA

Integrated photonic neural networks (IPNNs) are emerging as promising successors to conventional electronic AI accelerators as they offer substantial improvements in computing speed and energy efficiency. In particular, coherent IPNNs use arrays of Mach-Zehnder interferometers (MZIs) for unitary transformations to perform energy-efficient matrix-vector multiplication. However, the underlying MZI devices in IPNNs are susceptible to uncertainties stemming from optical lithographic variations and thermal crosstalk and can experience imprecisions due to non-uniform MZI insertion loss and quantization errors due to low-precision encoding in the tuned phase angles. In this article, we, for the first time, systematically characterize the impact of such uncertainties and imprecisions (together referred to as imperfections) in IPNNs using a bottom-up approach. We show that their impact on IPNN accuracy can vary widely based on the tuned parameters (e.g., phase angles) of the affected components, their physical location, and the nature and distribution of the imperfections. To improve reliability measures, we identify critical IPNN building blocks that, under imperfections, can lead to catastrophic degradation in the classification accuracy. We show that under multiple simultaneous imperfections, the IPNN inferencing accuracy can degrade by up to 46%, even when the imperfection parameters are restricted within a small range. Our results also indicate that the inferencing accuracy is sensitive to imperfections affecting the MZIs in the linear layers next to the input layer of the IPNN.

关键词： Adaptive optics Transmission line matrix methods Neurons Optical waveguides Optical interferometry Optical crosstalk Uncertainty Neural networks phase angles process variations quantization errors silicon photonics

来源：评论

学校读者我要写书评

暂无评论

Timing quantization error in lidar speed-measurement devices

引用

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2000年第1期49卷 276-280页

作者： Fisher, PD Pyhtila, JW Michigan State Univ Dept Elect & Comp Engn E Lansing MI 48824 USA

Minimizing the timing quantization error of lidar speed-measurement devices is an important step in reducing the magnitude of the speed-measurement errors associated with these devices. This paper presents a statistical model for the timing quantization error and demonstrates how this model can be used to select the values of key timing parameters. The values of these parameters must be carefully selected so that manufactured equipment meets current model lidar speed-measurement device performance standards established by the National Highway Traffic Safety Administration (NHTSA).

关键词： lidar quantization errors speed-measurement errors speed-measurement standards

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：