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基于标幺化模型的感应电动机矢量控制 被引量:5
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作者 孟志强 朱良焱 石瑜 《电力系统及其自动化学报》 CSCD 北大核心 2010年第5期152-155,共4页
在矢量控制的DSP实现中,采用参数的有名值进行计算,存在数据运算易溢出、数据运算精度低等不足。文中研究了感应电动机矢量控制的参数标幺化实现方案,核心技术建立在感应电动机数学模型的标幺化和采集信号的标幺化基础之上,详细推导了... 在矢量控制的DSP实现中,采用参数的有名值进行计算,存在数据运算易溢出、数据运算精度低等不足。文中研究了感应电动机矢量控制的参数标幺化实现方案,核心技术建立在感应电动机数学模型的标幺化和采集信号的标幺化基础之上,详细推导了感应电动机数学模型的标幺化方法和基本物理量及其基准值的选取。最后,给出了采集信号标幺化的具体实现过程。研究表明,该方案简化了程序设计,使DSP内算法实现得以优化,并且便于调试过程中对各物理量状态的监测。 展开更多
关键词 矢量控制 感应电动机 标幺化 有名值 基值
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Optimal Stochastic Scheduling Strategy of Multi-vector Energy Complex Integrated with Full-blown Power-to-biomethane Model
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作者 Guanwei Zeng Chengxi Liu +2 位作者 Minfang Liao Yongjian Luo Xuzhu Dong 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2024年第3期863-873,共11页
We propose an optimal stochastic scheduling strategy for a multi-vector energy complex(MEC),considering a fullblown model of the power-to-biomethane(Pt M)process.Unlike conventional optimization that uses a simple eff... We propose an optimal stochastic scheduling strategy for a multi-vector energy complex(MEC),considering a fullblown model of the power-to-biomethane(Pt M)process.Unlike conventional optimization that uses a simple efficiency coefficient to coarsely model energy conversion between electricity and biomethane,a detailed Pt M model is introduced to emphasize the reactor kinetics and chemical equilibria of methanation.This model crystallizes the interactions between the Pt M process and MEC flexibility,allowing to adjust the operating condition of the methanation reactor for optimal MEC operation in stochastic scenarios.Temperature optimization and flowsheet design of the Pt M process increase the average selectivity of methane(i.e.,ratio between net biomethane production and hydrogen consumption)up to 83.7%in the proposed synthesis flowsheet.Simulation results can provide information and predictions to operators about the optimal operating conditions of a Pt M unit while improving the MEC flexibility. 展开更多
关键词 Multi-vector energy complex optimal stochastic scheduling power-to-biomethane unit process synthesis natural gas
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Analysis on unit maximum capacity of orthogonal multiple watermarking for multimedia signals in B5G wireless communications
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作者 Mianjie Li Senfeng Lai +4 位作者 Jiao Wang Zhihong Tian Nadra Guizani Xiaojiang Du Chun Shan 《Digital Communications and Networks》 SCIE CSCD 2024年第1期38-44,共7页
Beyond-5G(B5G)aims to meet the growing demands of mobile traffic and expand the communication space.Considering that intelligent applications to B5G wireless communications will involve security issues regarding user ... Beyond-5G(B5G)aims to meet the growing demands of mobile traffic and expand the communication space.Considering that intelligent applications to B5G wireless communications will involve security issues regarding user data and operational data,this paper analyzes the maximum capacity of the multi-watermarking method for multimedia signal hiding as a means of alleviating the information security problem of B5G.The multiwatermarking process employs spread transform dither modulation.During the watermarking procedure,Gram-Schmidt orthogonalization is used to obtain the multiple spreading vectors.Consequently,multiple watermarks can be simultaneously embedded into the same position of a multimedia signal.Moreover,the multiple watermarks can be extracted without affecting one another during the extraction process.We analyze the effect of the size of the spreading vector on the unit maximum capacity,and consequently derive the theoretical relationship between the size of the spreading vector and the unit maximum capacity.A number of experiments are conducted to determine the optimal parameter values for maximum robustness on the premise of high capacity and good imperceptibility. 展开更多
关键词 B5G Multimedia information security Spread transform dither modulation Spreading vector measurement unit maximum capacity
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用矢量法证明开普勒三定律 被引量:3
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作者 李敏君 邱荒逸 《高师理科学刊》 2000年第4期25-27,共3页
给出一种运用矢量的特点和性质构造矢量函数 。
关键词 开普勒定律 矢量函数 单位矢量 行星 天体运动 引力定律
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全数字交流主轴伺服驱动器的设计 被引量:3
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作者 潘策 《组合机床与自动化加工技术》 北大核心 2012年第9期70-71,75,共3页
设计一种全数字交流主轴伺服驱动器。该系统以高性能数字信号处理单元为控制电路核心,采用先进的智能功率模块IPM(PM150RLA120)作为功率开关元件组成逆变器。采用转差频率式矢量控制,并设计了较为完善的检测与保护电路。实验结果表明,... 设计一种全数字交流主轴伺服驱动器。该系统以高性能数字信号处理单元为控制电路核心,采用先进的智能功率模块IPM(PM150RLA120)作为功率开关元件组成逆变器。采用转差频率式矢量控制,并设计了较为完善的检测与保护电路。实验结果表明,该系统具有良好的静态和动态性能。 展开更多
关键词 交流主轴伺服驱动 矢量控制 数字信号处理单元 智能功率模块
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刀具角度分析与计算的矢量方法 被引量:2
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作者 陈明 刘新宇 +1 位作者 黄卫 傅建军 《华北航天工业学院学报》 2000年第4期17-20,共4页
刀具技术是机械制造工业的基础与支柱,刀具角度的分析与计算是刀具技术中关键技术问题之一。提出分析与计算刀具角度的矢量方法,概述矢量基本知识,阐述刀具角度的矢量法基本原理及其应用,以适应刀具技术发展之需要。
关键词 刀具角度 矢量 幺矢
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Left-Invariant Minimal Unit Vector Fields on the Solvable Lie Group
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作者 Shaoxiang ZHANG Ju TAN 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2023年第1期67-80,共14页
Bozek(1980)has introduced a class of solvable Lie groups Gn with arbitrary odd dimension to construct irreducible generalized symmetric Riemannian space such that the identity component of its full isometry group is s... Bozek(1980)has introduced a class of solvable Lie groups Gn with arbitrary odd dimension to construct irreducible generalized symmetric Riemannian space such that the identity component of its full isometry group is solvable.In this article,the authors provide the set of all left-invariant minimal unit vector fields on the solvable Lie group Gn,and give the relationships between the minimal unit vector fields and the geodesic vector fields,the strongly normal unit vectors respectively. 展开更多
关键词 Solvable Lie groups Lagrangian multiplier method Minimal unit vector fields Geodesic vector fields Strongly normal unit vectors
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具有高效混洗模式存储器的可编程混洗单元 被引量:2
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作者 万江华 刘胜 +2 位作者 周锋 王耀华 陈书明 《国防科技大学学报》 EI CAS CSCD 北大核心 2011年第6期31-35,共5页
为向量DSP提出并设计了一种具有高效混洗模式存储器的可编程混洗单元,该结构能够使应用程序的混洗指令在执行时和通用寄存器或访存带宽等系统的关键资源分离,从而提高混洗单元的执行效率。采用区分不同混洗粒度和元素索引等方法对混洗... 为向量DSP提出并设计了一种具有高效混洗模式存储器的可编程混洗单元,该结构能够使应用程序的混洗指令在执行时和通用寄存器或访存带宽等系统的关键资源分离,从而提高混洗单元的执行效率。采用区分不同混洗粒度和元素索引等方法对混洗模式所对应的开关矩阵进行了压缩,我们的存储效率高于当前其他方案。该混洗单元具有可编程的特点,应用程序所需要的混洗模式可以提前由程序员编写并通过DMA等途径加载。对该混洗单元进行了VLSI实现及性能评测,结果显示此方案能够在给系统带来0.6%的额外面积开销基础上使应用程序的性能提升7.4%~17.4%。 展开更多
关键词 向量DSP 混洗单元 混洗模式存储器 混洗指令 存储效率
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用向量求解析几何两个基本公式
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作者 田卫东 沈积怀 《杨凌职业技术学院学报》 2005年第3期31-32,36,共3页
利用向量相等概念,只要已知起点、终点坐标即可求出向量的模,就可推证出两点间的距离公式;两向量相等,则与之对应的分量也相等,从而可利用代数方法求出定比分点公式。
关键词 定比分点 向量的模 等价向量 单位向量
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An FFT Performance Model for Optimizing General-Purpose Processor Architecture
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作者 李玲 陈云霁 +2 位作者 刘道福 钱诚 胡伟武 《Journal of Computer Science & Technology》 SCIE EI CSCD 2011年第5期875-889,共15页
General-purpose processor (GPP) is an important platform for fast Fourier transform (FFT),due to its flexibility,reliability and practicality.FFT is a representative application intensive in both computation and m... General-purpose processor (GPP) is an important platform for fast Fourier transform (FFT),due to its flexibility,reliability and practicality.FFT is a representative application intensive in both computation and memory access,optimizing the FFT performance of a GPP also benefits the performances of many other applications.To facilitate the analysis of FFT,this paper proposes a theoretical model of the FFT processing.The model gives out a tight lower bound of the runtime of FFT on a GPP,and guides the architecture optimization for GPP as well.Based on the model,two theorems on optimization of architecture parameters are deduced,which refer to the lower bounds of register number and memory bandwidth.Experimental results on different processor architectures (including Intel Core i7 and Godson-3B) validate the performance model.The above investigations were adopted in the development of Godson-3B,which is an industrial GPP.The optimization techniques deduced from our performance model improve the FFT performance by about 40%,while incurring only 0.8% additional area cost.Consequently,Godson-3B solves the 1024-point single-precision complex FFT in 0.368 μs with about 40 Watt power consumption,and has the highest performance-per-watt in complex FFT among processors as far as we know.This work could benefit optimization of other GPPs as well. 展开更多
关键词 fast Fourier transform (FFT) general-purpose processor (GPP) performance prediction model vector unit DMA
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Causalities between Price, Pond Area and Employment in Aquaculture Production
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作者 Nik Hashim Nik Mustapha Azlina Abd Aziz Nik Mohd Hazrul Hashim 《Natural Resources》 2013年第2期175-183,共9页
The role of aquaculture industry is becoming more prominent in order to supplement marine capture in meeting the food need for the growing Malaysian population. In an attempt to minimize depletion of marine fisheries,... The role of aquaculture industry is becoming more prominent in order to supplement marine capture in meeting the food need for the growing Malaysian population. In an attempt to minimize depletion of marine fisheries, only traditional vessels are allowed to fish along the coastal area while bigger vessels are relegated to deep-sea fishing. During the 9th Malaysian Plan (2006-2010) aquaculture has been recognized as the engine of growth in the national food sector’s development strategy. Future fisheries policy is expected to focus more on aquaculture production, marketing and technological improvement as an alternative to marine capture. This paper investigates the causalities between the selected freshwater fish prices, aquaculture area and production. The study aspires to establish whether or not market price is a key contributor to a rise in the aquaculture area and production. Aquaculture firms comprising the individual culturists are generally motivated by the economic potential of the industry which is reflected in excess of price over cost of production. Our hypothesis is that government policy and initiation rather than prices had give rise to greater participation of culturists and hence augmented the level of employment. However, production increase has a negative implication on environment degradation. Thus there is a conflicting view as regards to the employment opportunity generated by aquaculture undertakings and the need for sustainable development arising from this growing industry. Multivariate time series analysis was used in this investigation. 展开更多
关键词 AQUACULTURE unit Root COINTEGRATION vector Error Correction Model Granger’s CAUSALITY
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Boolean方阵的注记 被引量:1
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作者 宋占杰 鹿玲娣 +2 位作者 刘丽霞 佟宏志 杜同凯 《河北师范大学学报(自然科学版)》 CAS 2000年第2期164-165,共2页
Discussed some properties of Boolean square matrices mainly.
关键词 Boolean向量 Boolean方阵 单位矩阵
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基于向量拟合的电机设备电磁干扰建模方法 被引量:1
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作者 许洋 吴昊 +2 位作者 张宾 赵庆岚 冯培伦 《火力与指挥控制》 CSCD 北大核心 2020年第6期156-160,共5页
提出了一种基于向量拟合的电机设备电磁干扰建模方法。模型建立所采用的数据是通过对实际干扰设备的端口特性进行测量得到,测量过程简单方便。提出的两种通用电路拓扑单元,其电路参数可通过向量拟合进行求解。最后通过对一台三相电机进... 提出了一种基于向量拟合的电机设备电磁干扰建模方法。模型建立所采用的数据是通过对实际干扰设备的端口特性进行测量得到,测量过程简单方便。提出的两种通用电路拓扑单元,其电路参数可通过向量拟合进行求解。最后通过对一台三相电机进行建模,进行了数据误差分析,验证了模型具有准确性。本模型可以在10 kHz^70 MHz的频域内对电机设备的传导电磁干扰作出分析。 展开更多
关键词 向量拟合 电机设备 拓扑单元 端口特性 电磁干扰
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矢量分析中的单位矢量求偏导数问题及实例分析
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作者 韩敬 钟方川 陈龙溪 《江西科学》 2007年第6期765-768,共4页
矢量分析在《电动力学》及其相关学科中占有重要的地位,但在进行矢量分析时,往往忽视了单位矢量求偏导数问题,进而得出错误的结果。通过矢量分析中常见的错误,指出了单位矢量的偏导数在矢量分析中的重要性,并举出实例进行分析,旨在使广... 矢量分析在《电动力学》及其相关学科中占有重要的地位,但在进行矢量分析时,往往忽视了单位矢量求偏导数问题,进而得出错误的结果。通过矢量分析中常见的错误,指出了单位矢量的偏导数在矢量分析中的重要性,并举出实例进行分析,旨在使广大学者对这一问题有一个深刻的认识。 展开更多
关键词 矢量分析 电动力学 单位矢量 偏导数
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随时间变化的单位矢量
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作者 杨熙宁 《吉林大学学报(信息科学版)》 CAS 1990年第2期33-38,共6页
本文提出将一个复指数e^(iθ)明确为某平面上的一个单位矢量,并且用符号e^(iθ)来表示。则e^(iωt)就是一个随时间作逆时针均匀旋转的单位圆极化矢量。并且规定它的运算与复指数运算相同。
关键词 矢量场 复数/单位矢量 复指数
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THE FOURIER TRANSFORM FOR HOMOGENEOUS VECTOR BUNDLES OVER QUATERNION UNIT DISK
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作者 LIU JIANMING (School of Mathematical Sciences, Peking University, Beijing 100871. China.) E-mail: liujm@math. pku.edu.cn or liujm@sxx0.math.pku. edu.cn 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2000年第3期343-350,共8页
The Fourier transform for homogeneous vector bundles over quaternion unit disk is studied, and the corresponding inversion formula and Plancherel formula are established.
关键词 Fourier transform Homogeneous vector bundles Quaternion unit disk
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Performance Analysis of Thermal Energy System with Linear System Method
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作者 Liping LI Chunfa ZHANG 《Journal of Thermal Science》 SCIE EI CAS CSCD 2007年第3期231-236,共6页
The paper addresses the system performance of coal-fired power unit with changed auxiliary system or other local heat disturbance. The idea of state space model is imported and the universal formula for the calculatio... The paper addresses the system performance of coal-fired power unit with changed auxiliary system or other local heat disturbance. The idea of state space model is imported and the universal formula for the calculation of system performance output is deduced on the system state equation. Two important vector of system are worked out under linear system assumption and transform. The transfer matrix is the characteristics of system itself and is constant for a similar condition, which greatly facilitates the analysis. The concept of thermal disturbance vector is proposed to construct the thermal disturbance input easily. The method can be helpful for analyzing any thermal disturbance input satisfying the assumption and also for supplementing the correction means of performance test. An example of 600MW power unit is presented to demonstrate its availability. 展开更多
关键词 matrix vector power unit performance linear system method thermodynamic analysis.
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Impact of Inflation, Dollar Exchange Rate and Interest Rate on Red Meat Production in Turkey: Vector Autoregressive (VAR) Analysis
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作者 Senol Celik 《Chinese Business Review》 2015年第8期367-381,共15页
In this study, impact of inflation (WPI--Wholesale Price Index), exchange rate, and interest rate on the production of red meat in Turkey was examined using the vector autoregressive (VAR) model. The model consist... In this study, impact of inflation (WPI--Wholesale Price Index), exchange rate, and interest rate on the production of red meat in Turkey was examined using the vector autoregressive (VAR) model. The model consisting of variables of dollar exchange rate, inflation rate, interest rate, beef, buffalo meat, mutton, and goat meat production amounts has been estimated for the period from 1981 to 2014. It has been detected that there is a tie among the dollar exchange rate, inflation rate, interest rate, and the amount of red meat production in Turkey. In order to determine the direction of this relation, Granger causality test was conducted. A one-way causal relation has been observed between: the goat meat production and dollar exchange rate; the buffalo meat production and the mutton production; and the beef production and the mutton production. To interpret VAR model, the impulse response function and variance decomposition analysis was used. As a result of variance decomposition, it has been detected that explanatory power of changes in the variance of dollar exchange rate, inflation rate, and interest rate in goat meat production amount is more than explanatory power of changes in the variances of mutton, beef, and buffalo meat variables. 展开更多
关键词 vector autoregressive (VAR) model impulse response analysis variance decomposition unit root test CAUSALITY red meat
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基于多类支持向量机的汽轮发电机组故障诊断 被引量:29
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作者 翟永杰 王东风 韩璞 《动力工程》 CSCD 北大核心 2003年第5期2694-2698,共5页
故障诊断发展的瓶颈之一是故障样本的缺乏,而不仅在于诊断方法本身。支持向量机方法是专门针对小样本情况的,其目标是得到现有信息下的最优解而不仅仅是样本数趋于无穷大时的最优值。该文分析了多类支持向量机的DAGSVM算法,对于σ的取值... 故障诊断发展的瓶颈之一是故障样本的缺乏,而不仅在于诊断方法本身。支持向量机方法是专门针对小样本情况的,其目标是得到现有信息下的最优解而不仅仅是样本数趋于无穷大时的最优值。该文分析了多类支持向量机的DAGSVM算法,对于σ的取值,提出了基于错分样本数的变增量迭代算法,在小样本情况下对汽轮发电机组故障诊断进行了仿真研究,结果表明了该方法的有效性。 展开更多
关键词 支持向量机 汽轮发电机组 故障诊断
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分级聚类支持向量机在汽轮机故障诊断中的应用 被引量:20
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作者 翟永杰 毛继珮 +1 位作者 于丽敏 刘长良 《华北电力大学学报(自然科学版)》 CAS 北大核心 2003年第6期25-29,共5页
在两类支持向量机的基础上,综合分级聚类和决策树的思想构造多类支持向量机,从而简化了分类器结构,减少了分类器数量,避免了拒绝分类区的出现,并加快了训练和识别速度。在小样本情况下对多类汽轮发电机组故障进行了诊断研究,结果表明该... 在两类支持向量机的基础上,综合分级聚类和决策树的思想构造多类支持向量机,从而简化了分类器结构,减少了分类器数量,避免了拒绝分类区的出现,并加快了训练和识别速度。在小样本情况下对多类汽轮发电机组故障进行了诊断研究,结果表明该方法能够正确地对故障进行识别。 展开更多
关键词 汽轮机 故障诊断 分级聚类 支持向量机 统计学习理论 汽轮发电机组
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