On nonlinear dependencies in African stock markets

Ferreira, Dionisio, and Correia (2018. Physica A: Statistical Mechanics and Its Applications. 505, 680–687) showed that African stock markets at different time frames (before the Lehman Brothers financial crisis, during the crisis, and after the crisis) do not satisfy the efficient market hypothesis. Here, we provide evidence by means of six different nonparametric tests, and the fit of GARCH(1, 1), TGARCH(1, 1) and EGARCH(1, 1) models accounting for day of the week and month of the year effects that the majority of African stock markets do comply with the efficient market hypothesis.     

ISD4004系列语音芯片批量录音实现

ISD4004语音录放芯片在很多领域中有广泛的应用,但将语音信号录制到芯片的过程中存在诸多问题。文章介绍了该系列芯片的特点和工作原理,然后提出通过PC机的音频输出接口和RS232串行接口,结合单片机实现ISD4000系列语音芯片批量录制各种经过处理后的音频信号,并可实现对任意段音频输出的方法。     

基于双机控制的LED大屏幕动态显示系统

介绍了一种由PC机与单片机双机控制的 LED大屏幕显示系统的设计方法。PC机编辑显示内容,由汉字多点阵字模提取子程序生成汉字点阵,以串行方式发送字模信息和控制信息,80C51单片机接收来自上位机的数据并存储于RAM,经转码子程序将显示内容转换为合适的形式输出给LED大屏幕,实现动态循环显示。     

The nature of entrepreneurial experience,business failure and comparative optimism

Entrepreneurial (i.e. business ownership) experience may enable some entrepreneurs to temper their comparative optimism in subsequent ventures. The nature of entrepreneurial experience can shape how entrepreneurs adapt. Using data from a representative survey of 576 entrepreneurs in Great Britain, we find that experience with business failure was associated with entrepreneurs who are less likely to report comparative optimism. Portfolio entrepreneurs are less likely to report comparative optimism following failure; however, sequential (also known as serial) entrepreneurs who have experienced failure do not appear to adjust their comparative optimism. Conclusions and implications for entrepreneurs and stakeholders are discussed.     

AT89S8252中SPI接口工作原理

介绍了SPI总线接口的基本工作原理,阐述了AT89S8252单片机中SPI接口的工作原理,包括其主要特点、各个接口寄存器以及应用中的一些注意事项。     

智能楼宇防盗报警系统的应用

设计并实现了一个以微控制器MI24为核心的智能楼宇防盗报警系统。介绍了系统的结构、组成及软、硬件设计。本系统基于RS-485总线,监控主机和监控器之间采用自定义协议进行串行通信。     

The Source of Productivity Growth in Dutch Agriculture: A Perspective from Finance

In corporate finance, the impact of capital structure on firm performance has been widely studied. This article extends the capital structure study to the situation in agriculture, explicitly addressing the difference between family farms and corporate firms. We use the Malmquist productivity growth index as a proxy for performance to study the impact of capital structure (debt) on farm performance. We compare the results with those from the traditional performance model that uses profitability (e.g., return on equity (ROE)) as performance measure. Using data from Dutch arable farms, results show that debt has no effect on ROE, whereas it has a positive effect on productivity growth.     

航空行业项目管理创新的探索与实践

本文从航空产品传统项目管理出发,分析传统项目管理面临的问题及挑战,对项目进一步创新管理提出了迫切的需求。在原有项目管理基础上,对航空行业项目管理的创新进行了新的探索与实践,并提出了几点适合本公司航空行业项目管理创新的思考与建议。     

基于GPRS的一体化实时数字地籍测绘技术研究

文章研究了基于GPRS的一体化实时数字地籍测绘的工作原理和系统组成,分析了该技术的优点,并设计了手机端的通用RS-232串口数据读取程序。