一种大规模数字I/O通道的扩展方法

针对控制系统中普通数字I/O卡的通道数无法满足大规模数字I/O要求的问题,提出一种数字I/O通道扩展方案,并设计了一种32路光电隔离多通道数字I/O板,通过一个简单实例说明了这种扩展方案的具体实施,并证实其有效性.     

双正激ZVT-PWM开关电源充电机

介绍了一种双正激电路的软开关拓扑,分析了其软开关的工作原理,推导了实现软开关的关键技术参数的计算公式并采用该技术开发了１．８ｋＷ的充电电源。     

The ballot or the bomb belt: the roots of female suicide terrorism before and after 9/11

ABSTRACT

In recent years, an upward trend in terrorist attacks has mirrored an increase in suicide attacks. According to our preliminary analysis, the events of September 11^th marked a sea change in the number of terrorist attacks. While a rich literature has evaluated why terrorists participate in suicide attacks, none have considered the uptick in volume after 9/11, and fewer yet have considered how female fighters may be contributing to this. We evaluate how both structural and female-specific factors affect the likelihood of female fighter suicide attacks. Recent literature discovered a trend in terrorist groups using females as suicide bombers due to cultural norms that permit them to get closer to targets. We test our theory using data from the Chicago Project on Security and Threats Suicide Attack Database (CPOST-SAD) and various datasets from the Quality of Government (QOG) compendium for the 1986–2016 time period. We construct a series of models that consider both female-specific and structural factors that could explain variation in the number of female suicide attacks. Our results indicate that our models encompass relatively stable patterns. Female political empowerment, female educational attainment, and female employment rates are significant and positive in our post-9/11 models, indicating that they may increase female suicide attacks. Democracy is a relevant structural factor and generally yields a positive effect on female suicide attacks across both time periods and multiple models. Ethnic fractionalization is significant in both time periods but yields a negative effect before 9/11 and a positive effect in the later period.