便携式心电监护仪中信号采集电路的设计

本文介绍了一种便携式心电监护系统中信号采集电路的设计。该信号采集电路具有采集心电信号和检测R波等功能。采用AD620作为放大器核心元件,使系统具有低噪音、低漂移和高信噪比等优点,而且成本低廉,体积小,使用方便。     

音响放大器电路设计与调试初探

为了让高职院校电子类、通信类学生学习、了解音响放大器电路设计原理,探索调试过程,提高电子类技术的建设的发展。文章主要从设计和制造等方面对音响放大器电路进行设计,详细介绍了放大器内部工作元例,并掌握了基本参数测试方法,给学生奠定了坚实的理论基础,展现了职业化教育的特点。     

波分复用系统中的拉曼光纤放大器的原理与设计应用

随着掺铒光纤放大器的成熟应用以及通信技术的飞速发展,掺铒光纤放大器的缺点也越来越突出,势必要求一种新的光放大器来适应新的通信需求,而拉曼光纤放大器以它明显的优点,成为了满足新的通信需求的最好选择。     

集成运算放大器的调试

在中专电子技术课程教学中，集成运算放大器的调试实验常常让学生手忙脚乱，为了提高学生实践技能，总结集成运算放大器的调试的几点经验。     

基于CMOS工艺的2.4GHz低噪声放大器的ADS设计

本文采用了SMIC0.18μm工艺,设计了一款应用在2.4Ghz(蓝牙系统)的低噪声放大器(LNA)。通过该实例,详细介绍了设计CMOS低噪声放大器的整个过程。文章先初步构建了一个单端共源-共栅结构放大电路,然后对该放大电路进行了理论分析,最后采用射频设计软件ADS(Advanced Design System)对其进行了模拟优化,在2.4Ghz时获得了1.443dB的噪声系数(NF)。模拟结果表明本文设计的低噪声放大器有噪声低,增益高的优点,且匹配良好。     

锚杆钻机2.5倍扭矩放大器的研究与分析

本文为适应巷道支护高强度预紧力的需要,提出了一种锚杆钻机扭矩放大器,简化了巷道支护高强度预紧力复杂的施工工艺,提高了巷道支护高强度预紧力施工的安全性,降低了巷道支护高强度预紧力施工的劳动强度。     

压电测试技术实验教学研究

在压电测试技术实验教学中,必然要接触电荷放大器的使用,笔者通过电路分析,建立了压电测量系统输入理学物理量与输出物理量关系式,有助于使用者掌握压电测试系统被测物理量与输出电压间的函数关系,也使得电荷放大器使用中的"归一化"操作可以省略。     

程控放大器的实现

通过数/模转换器,实现了一种增益可调的程控放大器。程控放大器的增益由单片机输出的数字量控制,有种增益可供选择。这种程控放大器具有电路简单,增益调整方便,成本低等特点。随着电子技术和计算机技术的发展,程控放大器有着广大的应用前景,并将朝着集成化、智能化、多功能化方向发展。     

判断放大器的反馈类型

由于判断具有一定的难度,放大器反馈类型,因此应用常规方法判断放大器反馈类型时容易出错,文章在此简要介绍一些判断反馈类型的技巧,可为相关工作者提供参考。     

红外遥控接收放大器引线键合工艺参数对封装质量的影响因素分析

红外遥控接收放大器在各种电器上有广泛的应用,文章主要针对红外遥控接收放大器金丝键合主要工艺参数对封装质量影响因素进行简要的分析,并进一步提出引线键合工艺参数对封装质量的影响因素,以供参考。     

基于ICA的图像去噪技术研究

ICA(Independent Component Analysis)可以仅由简单的几个假设条件,还原出原始相互独立的分量。利用ICA这一特点可对与噪声数据相互独立的图像数据进行分离,达到图像去噪的目的。文章对有噪图像进行小波处理,构建一个虚拟通道作为一个输入,对原有噪图像和构建出的虚拟通道进行分离,可得到去噪图像。传统去噪方法与文中所用方法的处理结果进行了比较。     

Principles of controlling traffic noise : Solving a multi-objective decision problem

The main objectives for a government to control traffic noise are such as economic efficiency, a reasonable welfare distribution and acceptable noise standards. The instruments available for arriving at these objectives are traffic control, emission regulation and environment protection. This paper analyzes how to make trade-offs between such objectives and how to choose a combination of noise control instruments. Special attention is then made to one welfare distribution objective, namely the ‘polluters-pay-principle’. That principle demands using the vehicle tax to finance investments to protect environment. And in order to stimulate the development of less noisy vehicles such a tax has to be progressively increased for noisy cars. The analysis is demonstrated on the situation of Sweden where a differentiation of norms as well as of vehicle taxes is proposed.     

Multidimensional noise and non-fundamental information diversity

This paper relaxes the common assumption of the standard competitive noisy rational expectations framework that noise is one-dimensional. Within an environment characterized by multidimensional noise, I explore the strategic interactions between different traders that are informed about different components of the noise inherent in the market price. If noise is two-dimensional, several new types of complementarities in traders’ interactions arise that cannot be studied in the classical one-dimensional framework. The higher-dimensional case uncovers that higher dimensionality of noise mitigates the possibility of a market breakdown by weakening adverse selection. On the basis of the theoretical results, I discuss some predictions and implications concerning the effects of the increased usage of “payment for order flow” in financial markets.     

Estimating the conditional mode of a stationary stochastic process from noisy observations

Let {(X _i, Y _i,)}, i≥1, be a strictly stationary process from noisy observations. We examine the effect of the noise in the response Y and the covariates X on the nonparametric estimation of the conditional mode function. To estimate this function we are using deconvoluting kernel estimators. The asymptotic behavior of these estimators depends on the smoothness of the noise distribution, which is classified as either ordinary smooth or super smooth. Uniform convergence with almost sure convergence rates is established for strongly mixing stochastic processes, when the noise distribution is ordinary smooth. Received: April 1998     

Performance measure properties and efficacy of incentive contracts: perceptions of U. S. employees

This paper examines how employees perceive the impact of performance measure properties (noise and distortion) on the efficacy of incentive contracts in the United States. It surveys 98 employees at middle and lower levels of U. S. firms across different industries. The survey results show that employees perceive noise and distortion in performance measures to significantly influence the overall efficacy of incentive plans. Specifically, employees perceive that incentive plans with less noisy or distorted measures attract better employees to their firms. However, employees do not perceive lower noise or distortion in performance measures to motivate more effort in their work after controlling for the selection effect of incentive plans. These results illustrate the importance of performance measure properties in the U. S. incentive contracts and provide evidence regarding cross-national differences in management practices.     

Randomized algorithms for statistical image analysis and site percolation on square lattices

We propose a novel probabilistic method for detection of objects in noisy images. The method uses results from percolation and random graph theories. We present an algorithm that allows to detect objects of unknown shapes in the presence of random noise. The noise density is assumed to be unknown and can be very irregular. The algorithm has linear complexity and exponential accuracy, and is appropriate for real‐time systems. We prove results on consistency and algorithmic complexity of our procedure. © 2013 The Authors. Statistica Neerlandica © 2013 VVS.     

晶体管多级放大电路中的负载问题研究

多级放大电路由输入级、中间级和输出级组成。通常要求输入级具有输入阻抗高和噪声低的特性;中间级应有较大的电压放大倍数;输出级应有输出阻抗低和输出功率大的特点。对于复杂电路的负载问题分析比较困难,本文对多级放大电路中负载问题做一些总结。     

Contracting on the Stock Price and Forward-Looking Performance Measures

Abstract

We examine the use of earnings, forward-looking performance measures and stock prices in managerial compensation. When the firm's owner and its manager have identical time preferences, the stock price is not useful for motivating the manager, as it is a noisy aggregation of a forward-looking measure and future earnings. In contrast, when the owner and the manager have conflicting time preferences, the noisy stock price is useful for contracting. If the manager has no access to banking and cannot trade the firm's shares, the timeliness of the stock price dominates the extra risk imposed by its noise. At the same time, forward-looking performance measures (such as customer satisfaction) can induce a desirable allocation of management effort between the short term and long term more efficiently than the stock price can. Forward-looking performance measures and the stock price are thus not direct substitutes in rewarding farsighted effort.     

Optimal contest design under reverse-lottery technology

In this paper, we study effort-maximizing contest design under the “reverse” nested lottery contest model of Fu et al. (2014) — which is the “mirror image” of the conventional nested lottery contest of Clark and Riis (1996). We show that under the reverse-lottery technology, a single-stage winner-take-all grand contest dominates all other feasible designs when the contest is sufficiently noisy. This result is in dramatic contrast to the conventional wisdom on the optimality of multistage elimination contests that is grounded under the conventional nested lottery contest technology in the literature. In the framework of a noisy-performance ranking model, the conventional and reverse models differ only in the noise on players’ performance. Our study therefore reveals the important role that the noise term plays in modeling imperfectly discriminatory contests.     

数字幅频均衡功率放大器

设计实现了一个数字幅频均衡的功率放大器。该系统分为前置放大器、带阻网络、FPGA数字处理模块、功率放大器等模块组成。测试结果表明,该数字幅频均衡功率放大器具有高增益、高带宽和高效率等优点。