船舶机舱自动检测系统中虚拟数字示波器的设计

为了提高船舶机舱检测的自动化程度,本文以数字信号处理芯片、复杂可编程逻辑器件和USB接口芯片为核心硬件,设计了一个虚拟数字示波器,用于检测和显示船舶机舱内油压、油温、水温、转速等参数。该数字示波器由信号调理与A/D变换、逻辑控制、数据处理等电路组成,实验表明达到了预期的检测目的。该设备通过USB总线与主机相连接,功能的加载和更新由软件实现,因而具有灵活、实时、多功能等优点。     

郑州铁路苗圃地区铁道车辆运行噪声污染现状调查

我们于1982年8～9月,在有关人员协助下,对东、西、南三面紧邻铁道线的郑州铁路苗圃地区进行了列车运行噪声对环境污染现状的调查。目的了解噪声污染程度,选一远离铁道线、环境较为安静的劳动路家属区作对照。以便针对存在问题,采取必要措施,并为今后铁道干线的改建,城市建设规划、以及为降噪措施提供参考数据。     

液体二氧化硫污染环境引起的急性中毒

1984年5月某日上午10点30分钟左右,铁路某货场在分装一罐车液体二氧化硫时,导管破漏,造成二氧化硫外溢,使周围环境受到严重污染。为防止类似事件的发生,现将调查资料报道如下。一、事故经过     

Improved scheme of internet congestion control under moving average filter

An important task of Internet congestion control is inhibiting sporadic data flow to maintain a suitable window size or route queue length. Such a requirement is just consistent with the basic idea and function of a moving average filter. In this paper one prior Internet congestion control model, named transmission control protocol (TCP)/random early detection (RED) stroboscopic model, is studied, and then one new scheme is proposed to enlarge its stable domain, where a simple moving average filter is introduced to inhibit sporadic data flow as possible. In the novel scheme the bifurcation phenomenon is postponed without any extra controller. The effectiveness of the new scheme is verified by theoretical analyses and numerical simulations.