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sampling

取样是指从总体中抽取个体或样品的过程,也即对总体进行试验或观测的过程。分随机抽样和非随机抽样两种类型。前者指遵照随机化原则从总体中抽取样本的抽样方法,它不带任何主观性,包括简单随机抽样、系统抽样、整群抽样和分层抽样。后者是一种凭研究者的观点、经验或者有关知识来抽取样本的方法,带有明显主观色彩。参见“随机抽样”、“非随机抽样”。[1]
  • Title : Implementation of quadrature modulation and demodulation Design Object : By implementing qu

    Title : Implementation of quadrature modulation and demodulation Design Object : By implementing quadrature modulation and demodulation of analog signals in digital signal processing, students will have better understanding of sampling and frequency analysis of discrete-time signals. Design Content : Make a MATLAB function which performs quadrature modulation and demodulation for a input signal with anti-aliasing filtering.

    标签: Implementation demodulation implementing modulation

    上传时间: 2013-12-09

    上传用户:蠢蠢66

  • WiseMAC is a medium access control protocol designed for the WiseNETTMwireless sensor network. It i

    WiseMAC is a medium access control protocol designed for the WiseNETTMwireless sensor network. It is based on CSMA and uses the preamble sampling technique to minimize the power consumed when listening to an idle medium.

    标签: WiseNETTMwireless designed protocol WiseMAC

    上传时间: 2014-01-20

    上传用户:x4587

  • X-MAC, a low power MAC protocol for wireless sensor networks (WSNs). Standard MAC protocols develo

    X-MAC, a low power MAC protocol for wireless sensor networks (WSNs). Standard MAC protocols developed for duty-cycled WSNs such as BMAC, which is the default MAC protocol for TinyOS, employ an extended preamble and preamble sampling.

    标签: MAC protocols Standard networks

    上传时间: 2014-01-13

    上传用户:王楚楚

  • DAKOTA

    Computational models are commonly used in engineering design and scientific discovery activities for simulating complex physical systems in disciplines such as fluid mechanics, structural dynamics, heat transfer, nonlinear structural mechanics, shock physics, and many others. These simulators can be an enormous aid to engineers who want to develop an understanding and/or predictive capability for complex behaviors typically observed in the corresponding physical systems. Simulators often serve as virtual prototypes, where a set of predefined system parameters, such as size or location dimensions and material properties, are adjusted to improve the performance of a system, as defined by one or more system performance objectives. Such optimization or tuning of the virtual prototype requires executing the simulator, evaluating performance objective(s), and adjusting the system parameters in an iterative, automated, and directed way. System performance objectives can be formulated, for example, to minimize weight, cost, or defects; to limit a critical temperature, stress, or vibration response; or to maximize performance, reliability, throughput, agility, or design robustness. In addition, one would often like to design computer experiments, run parameter studies, or perform uncertainty quantification (UQ). These approaches reveal how system performance changes as a design or uncertain input variable changes. sampling methods are often used in uncertainty quantification to calculate a distribution on system performance measures, and to understand which uncertain inputs contribute most to the variance of the outputs. A primary goal for Dakota development is to provide engineers and other disciplinary scientists with a systematic and rapid means to obtain improved or optimal designs or understand sensitivity or uncertainty using simulationbased models. These capabilities generally lead to improved designs and system performance in earlier design stages, alleviating dependence on physical prototypes and testing, shortening design cycles, and reducing product development costs. In addition to providing this practical environment for answering system performance questions, the Dakota toolkit provides an extensible platform for the research and rapid prototyping of customized methods and meta-algorithms

    标签: Optimization and Uncertainty Quantification

    上传时间: 2016-04-08

    上传用户:huhu123456

  • ads8556i

    16-, 14-, 12-Bit, Six-Channel, Simultaneous sampling ANALOG-TO-DIGITAL CONVERTERS

    标签: 8556i 8556 ads

    上传时间: 2018-06-07

    上传用户:nj精灵

  • Gibbs法采样程序代码

    给定统计样本集,如何估计产生这个样本集的随机变量概率密度函数,是比较熟悉的概率密度估计问题。 求解概率密度估计问题的常用方法是最大似然估计、最大后验估计等。但是思考概率密度估计问题的逆问题:给定一个概率分布p(x),如何让计算机生成满足这个概率分布的样本。 这个问题就是统计模拟中研究的重要问题–采样(sampling)。Gibbs采样算法对应的java程序。

    标签: Gibbs 采样 程序 代码

    上传时间: 2019-01-11

    上传用户:Worm_Lemon

  • virtual decomposition control

    obot control, a subject aimed at making robots behave as desired, has been extensively developed for more than two decades. Among many books being published on this subject, a common feature is to treat a robot as a single system that is to be controlled by a variety of control algorithms depending on different scenarios and control objectives. However, when a robot becomes more complex and its degrees of freedom of motion increase substantially, the needed control computation can easily go beyond the scope a modern computer can handle within a pre-specified sampling period. A solution is to base the control on subsystem dynamics.

    标签: decomposition virtual control

    上传时间: 2019-09-04

    上传用户:txb96

  • Mobile+and+Wireless+Design+Essentials

    Mobile and wireless application development has come a long way in the past few years. It has progressed beyond the hype of wireless Web applications for consumers to the reality of high-value mobile applications for corporate users. Opportunities abound for creating new mobile and wireless applications that provide vital benefits to any business. A sampling of these benefits includes increased worker productivity, reduced processing costs, heightened accuracy, and competitive advantage. In contrast is the concern that developing mobile and wireless applications will involve many new technologies and concepts that many corporate developers are still learning to use.

    标签: Essentials Wireless Mobile Design and

    上传时间: 2020-05-30

    上传用户:shancjb

  • 基于TMS320F2812 光伏并网发电模拟装置PROTEL设计原理图+PCB+软件源码+WORD论

    基于TMS320F2812 光伏并网发电模拟装置PROTEL设计原理图+PCB+软件源码+WORD论文文档,硬件采用2层板设计,PROTEL99SE 设计的工程文件,包括完整的原理图和PCB文件,可以做为你的学习设计参考。 摘要:本文实现了一个基于TMS320F2812 DSP芯片的光伏并网发电模拟装置,采用直流稳压源和滑动变阻器来模拟光伏电池。通过TMS320F2812 DSP芯片ADC模块实时采样模拟电网电压的正弦参考信号、光伏电池输出电压、负载电压电流反馈信号等。经过数据处理后,用PWM模块产生实时的SPWM 波,控制MOSFET逆变全桥输出正弦波。本文用PI控制算法实现了输出信号对给定模拟电网电压的正弦参考信号的频率和相位跟踪,用恒定电压法实现了光伏电池最大功率点跟踪(MPPT),从而达到模拟并网的效果。另外本装置还实现了光伏电池输出欠压、负载过流保护功能以及光伏电池输出欠压、过流保护自恢复功能、声光报警功能、孤岛效应的检测、保护与自恢复功能。系统测试结果表明本设计完全满定设计要求。关键词:光伏并网,MPPT,DSP  Photovoltaic Grid-connected generation simulator Zhangyuxin,Tantiancheng,Xiewuyang(College of Electrical Engineering, Chongqing University)Abstract: This paper presents a photovoltaic grid-connected generation simulator which is based on TMS320F2812 DSP, with a DC voltage source and a variable resistor to simulate the characteristic of photovoltaic cells. We use the internal AD converter to real-time sampling the referenced grid voltage signal, outputting voltage of photovoltaic, feedback outputting voltage and current signal. The PWM module generates SVPWM according to the calculation of the real-time sampling data, to control the full MOSFET inverter bridge output sine wave. We realized that the output voltage of the simulator can track the frequency and phase of the referenced grid voltage with PI regulation, and the maximum photovoltaic power tracking with constant voltage regulation, thereby achieved the purpose of grid-connected simulation. Additionally, this device has the over-voltage and over-current protection, audible and visual alarm, islanding detecting and protection, and it can recover automatically. The testing shows that our design is feasible.Keywords: Photovoltaic Grid-connected,MPPT,DSP 目录引言 11. 方案论证 11.1. 总体介绍 11.2. 光伏电池模拟装置 11.3. DC-AC逆变桥 11.4. MOSFET驱动电路方案 21.5. 逆变电路的变频控制方案 22. 理论分析与计算 22.1. SPWM产生 22.1.1. 规则采样法 22.1.2. SPWM 脉冲的计算公式 32.1.3. SPWM 脉冲计算公式中的参数计算 32.1.4. TMS320F2812 DSP控制器的事件管理单元 42.1.5. 软件设计方法 62.2. MPPT的控制方法与参数计算 72.3. 同频、同相的控制方法和参数计算 8

    标签: tms320f2812 光伏 并网发电 模拟 protel pcb

    上传时间: 2021-11-02

    上传用户:

  • 电动汽车永磁无刷直流电机控制器设计

    对某四轮独立驱动电动汽车轮毂电机进行研究,设计一种永磁无刷直流电机控制器.以STM32F103RBT6芯片为基础,对电机驱动电路、采样电路和保护电路分别进行硬件设计与分析;同时,采用模块化软件设计方案,对该控制器的软件系统进行升级.实验验证表明:所设计的电机控制器能使电机响应迅速、转速稳定、无超调,且电动车动力输出性能良好.A permanent magnet brushless direct current motor controller was designed by studying the hub motor of a four-wheel independent drive electric vehicle.Based on STM32 F103RBT6 chip,the hardware design and analysis of motor drive circuit,sampling circuit and protection circuit were carried out respectively.At the same time,modular software design scheme was adopted to upgrade the software system of the controller.Experimental results show that the designed motor controller can ensure the motor fast response,stable speed,no overshoot,and good power output performances.

    标签: 电动汽车 永磁无刷直流电机

    上传时间: 2022-03-26

    上传用户:qingfengchizhu