茶叶仓储环境监控系统的设计

针对茶叶储存过程中变质以及人工监管不到位问题,设计了茶叶仓储环境监控系统,实现了对茶叶仓储环境的实时监控、报警提醒以及数据保存的功能,达到节省人力资源、减少变质损失的目的。     

一种新颖的低功耗、强移动性的密码锁设计

本文介绍一种基于单片机控制的电子密码锁设计。本系统由P89LPC900系列单片机、矩阵键盘和报警系统组成。系统能完成电子控制开锁、超时报警、超次锁定、管理员解密和修改用户密码的基本功能。除上述基本的密码锁功能外,还具有节电模式、掉电存储、按键中断唤醒等功能。该系统结构简洁、成本低、体积小,功能实用。     

An analysis of the reasons for the asymmetries surrounding earnings benchmarks

Several studies report an asymmetry in the distribution of earnings around specified benchmarks. However, doubt has arisen over whether the observed ‘kink’ in the distribution of earnings is solely caused by earnings management. We use a ratio analysis approach to examine a range of specific accruals for evidence of earnings management. We find little evidence that firms immediately above the benchmark have abnormal receivables, inventories or provisions. However, they do increase cash‐from‐customers and reduce inventory. Thus, our results support the recent research that suggests that firms engage in real actions to meet earnings benchmarks.     

Measurement Error in Access to Markets*

Microeconometric studies increasingly utilize travel times to markets as a determinant of economic behaviour. These studies typically use self‐reported measures from surveys, often characterized by measurement error. This paper is the first validation study of access to markets data. Unique data from Peru allow comparison of self‐reported variables with scientifically calculated variables. We investigate the determinants of the deviation between imputed and self‐reported data and show that it is non‐classical and dependent on observable socio‐economic variables. Our results suggest that studies using self‐reported measures of access may be estimating biased effects.     

直接数字频率合成技术在信号源中的应用

文章介绍了美国模拟器件公司采用先进直接数字频率合成技术(DDS)生产的高集成度产品AD9851芯片的引脚功能、特性和工作原理,同时介绍了单片机技术与AD9851在信号源中的应用,给出了具体硬件电路和控制参考程序.     

基于单片机给水模糊控制实现

本设计以STC89C52RC单片机作为单片机给水模糊控制系统设计的控制核心,主要实现:人工设定液位,利用LCD1602显示实时液位和设定液位,恒液位控制,液位越限报警等功能,通过软件程序实现系统的自动闭环控制,使容器内液位达到设定值。     

智能健康监护系统软件设计

智能健康监护系统是针对物联网技术在医疗方面的应用,基于嵌入式系统、无线通信、手持设备等最新实用技术,以社区家庭老人健康监护为应用目的医疗系统。系统由STC12C5A60S2为感知层平台、GSM/GPRS无线传输构成为网络层、PC机和手持设备终端为应用层的三层结构。应用层的软件系统设计采用模块化、插件化、标准化的各个子系统设计。所有子系统按照平台需求采用不同的软件平台开发。     

基于AD9626的高速模拟信号采集设备设计

文章介绍高速ADCAD9626的功能,详细说明使用FPGA来控制AD9626构成高速、高精度模拟信号采集设备的设计方法,并给出具体实现的设计方案和设计过程。     

智能车辆流量检测器的设计与实现

本文介绍了利用单片机如何实现智能环形线圈车辆检测器，讨论了此类检测器的软硬件设计要点。给出了相应的接口电路。     

Corruption Via Media Capture: The Effect of Competition

In this article, we compare a government's optimal choice of whether to engage in corruption by capturing the media outlets through bribery in two alternative media market structures: monopoly versus duopoly. While there is an extra bribe claimant in a media duopoly relative to monopoly, it may also be harder for each firm to individually expose corruption when the rival co‐opts with the government. We find that when the latter effect is stronger than the former, media is captured at lower bribes under duopoly relative to monopoly and in such instances media competition facilitates rather than hindering corruption.